ABSTRACT ENTER CLASSIFICATION An Overview on Portable Human Machine Interfaces for Teleoper
英语论文摘要应该如何写？How to Write Abstract？
Structure of abstract | Features of an abstract
Concise – write everything relevant to the paper in as simple terms as possible. Objective – states objectively the main points of the paper. Consistent – be consistent with the other parts of the whole paper, and never include what has not been mentioned in the paper. Complete – cover all the main points of the paper and be a miniature of the paper. Brief – conveys in as few words as possible the essential information contained in the body of the paper.
To DESCRIBE the angle of observing issues
… from the angle of… … in the light of the context that… To view something at a different angle/from various angles… From the point of view of… From the perspective of…
informative abstract - the primary research objective or purpose - method employed in solving the problems - principal findings or results - major conclusions and serves as a substitute for the full paper descriptive abstract outlines the topics covered in the paper and is like a table of contents in paragraph form.
classification
classificationClassification is a fundamental task in machine learning and data analysis. It involves categorizing data into predefined classes or categories based on their features or characteristics. The goal of classification is to build a model that can accurately predict the class of new, unseen instances.In this document, we will explore the concept of classification, different types of classification algorithms, and their applications in various domains. We will also discuss the process of building and evaluating a classification model.I. Introduction to ClassificationA. Definition and Importance of ClassificationClassification is the process of assigning predefined labels or classes to instances based on their relevant features. It plays a vital role in numerous fields, including finance, healthcare, marketing, and customer service. By classifying data, organizations can make informed decisions, automate processes, and enhance efficiency.B. Types of Classification Problems1. Binary Classification: In binary classification, instances are classified into one of two classes. For example, spam detection, fraud detection, and sentiment analysis are binary classification problems.2. Multi-class Classification: In multi-class classification, instances are classified into more than two classes. Examples of multi-class classification problems include document categorization, image recognition, and disease diagnosis.II. Classification AlgorithmsA. Decision TreesDecision trees are widely used for classification tasks. They provide a clear and interpretable way to classify instances by creating a tree-like model. Decision trees use a set of rules based on features to make decisions, leading down different branches until a leaf node (class label) is reached. Some popular decision tree algorithms include C4.5, CART, and Random Forest.B. Naive BayesNaive Bayes is a probabilistic classification algorithm based on Bayes' theorem. It assumes that the features are statistically independent of each other, despite the simplifying assumption, which often doesn't hold in the realworld. Naive Bayes is known for its simplicity and efficiency and works well in text classification and spam filtering.C. Support Vector MachinesSupport Vector Machines (SVMs) are powerful classification algorithms that find the optimal hyperplane in high-dimensional space to separate instances into different classes. SVMs are good at dealing with linear and non-linear classification problems. They have applications in image recognition, hand-written digit recognition, and text categorization.D. K-Nearest Neighbors (KNN)K-Nearest Neighbors is a simple yet effective classification algorithm. It classifies an instance based on its k nearest neighbors in the training set. KNN is a non-parametric algorithm, meaning it does not assume any specific distribution of the data. It has applications in recommendation systems and pattern recognition.E. Artificial Neural Networks (ANN)Artificial Neural Networks are inspired by the biological structure of the human brain. They consist of interconnected nodes (neurons) organized in layers. ANN algorithms, such asMultilayer Perceptron and Convolutional Neural Networks, have achieved remarkable success in various classification tasks, including image recognition, speech recognition, and natural language processing.III. Building a Classification ModelA. Data PreprocessingBefore implementing a classification algorithm, data preprocessing is necessary. This step involves cleaning the data, handling missing values, and encoding categorical variables. It may also include feature scaling and dimensionality reduction techniques like Principal Component Analysis (PCA).B. Training and TestingTo build a classification model, a labeled dataset is divided into a training set and a testing set. The training set is used to fit the model on the data, while the testing set is used to evaluate the performance of the model. Cross-validation techniques like k-fold cross-validation can be used to obtain more accurate estimates of the model's performance.C. Evaluation MetricsSeveral metrics can be used to evaluate the performance of a classification model. Accuracy, precision, recall, and F1-score are commonly used metrics. Additionally, ROC curves and AUC (Area Under Curve) can assess the model's performance across different probability thresholds.IV. Applications of ClassificationA. Spam DetectionClassification algorithms can be used to detect spam emails accurately. By training a model on a dataset of labeled spam and non-spam emails, it can learn to classify incoming emails as either spam or legitimate.B. Fraud DetectionClassification algorithms are essential in fraud detection systems. By analyzing features such as account activity, transaction patterns, and user behavior, a model can identify potentially fraudulent transactions or activities.C. Disease DiagnosisClassification algorithms can assist in disease diagnosis by analyzing patient data, including symptoms, medical history, and test results. By comparing the patient's data againsthistorical data, the model can predict the likelihood of a specific disease.D. Image RecognitionClassification algorithms, particularly deep learning algorithms like Convolutional Neural Networks (CNNs), have revolutionized image recognition tasks. They can accurately identify objects or scenes in images, enabling applications like facial recognition and autonomous driving.V. ConclusionClassification is a vital task in machine learning and data analysis. It enables us to categorize instances into different classes based on their features. By understanding different classification algorithms and their applications, organizations can make better decisions, automate processes, and gain valuable insights from their data.。
英语抽象词及其翻译
Abstract: One of the features of modern English is the wide use of abstract nouns in all kinds of writing. Abstract nouns are characterized by simplicity in form but generalization and vagueness in meaning. In E-C translation, English abstract nouns should be flexibly dealt with, otherwise there would occur improper Chinese if they were translated word for word. This paper gives a relatively systematic analysis of English abstract nouns and discussions on origin, formation, classification and translation respectively. Finally, some suggestions are offered on the basis of the discussions and the analysis.Key Words: abstract noun, origin, formation, classification, E-C translation.English Abstract Nouns and Their Translation英语抽象词及其翻译1. IntroductionNowadays, abstract nouns are frequently found in modern English. But it is not always easy to catch them and let alone to translate them. So, for English majors, it is under the necessity of making a research on them. To begin with, we need to mak e clear what abstract nouns are. “Ab stract” means “existing in thought or as an idea but not having a physical or practical existence”. (A .S.Hornby, 2000) The abstract nouns refer to an abstract quality or state, e.g., goodness or freedom. The mode of thinking, the feature of thinking and the style of thinking are language philosophical mechanism. Therefore, not only should we wipe off the barrier of languages but also we should constitute a new way of thinking in language research and translation.2. Origin of English Abstract NounsAs a matter of fact, every nation has its abstract or concrete thinking. Due to the historical reasons and cultural differences, various nations have their own unique concerns and selections. It is known to us that English people emphasize abstract thinking while the Chinese focus on concrete thinking. But what’s the real cause of this common phenomenon? The Chinese tend to think and observe things from specific perspectives. It is not habitual for them to do research and work out the relationship among different things, that is, to build abstract regulations. They pay much attention to concrete things so as to complement the abstract meanings with vivid words and express their emotions. Y et English people praise highly on deep thinking.（刘宓庆, 1996）In the process of analyzing the objective world, they take classification as their basic method and get through the surface to understand the deeper meaning. Finally, the pure abstract thinking personality has been formed. (甲小龙,1996，12)The Chinese strive perseveringly for perceptive cognition to convey profound and reasonable thought and to show connotation through skillful perception of analogy. This can be found in the vivid image by the features of pictograph, associative compounds, and pictophonetic characters. As Rudolf Flesh said, “so naturally, instead of using words like institutionalizing or anti-progressivism, as our thinkers do, they (the Chinese) formed the habits of expressing ideas by metaphors, similes and allegories, in short, by every known device for making a thing plain by comparing it with something else”.（R.Flesh, 1949）The western people lay stress on thinking which leads to the losing of the vividness in word formation and finally their words become the conceptual signs. The minimal meaning unit of the word is morphemes, which are also a linguistic abstraction and a concept. It is obvious that the use of abstract nouns in English is more frequent than that in Chinese. We can find the action abstract nouns, which contain the behavior meaning and action meaning. For example,a) I marveled at the relentless determination of the rain.b) He had surfaced with less visibility in the policy decision.Abstract nouns can also be found to express people, object or phenomenon. Le t’s look the example,e.g. Wisdom prepares for the worst, but folly leaves the worst for the day it comes.Abstract nouns are also used to convey the complicated reasoning concept.e.g. The absence of intelligence is an indication of satisfactory developmentFrom the above examples, we can find that more abstract nouns are used in English than in Chinese. So the proper use of abstract nouns will make translation more idiomatic.3. Formation of Abstract NounsThere are mainly two ways to form abstract nouns. One is to form a noun from a verb or an adjective. The other is to form a noun from a verbal phrase or a prepositional phrase.3.1Abstract Nouns Composed by Adding SuffixesAbstract nouns can be formed by adding suffixes, as:-ness, -tion, -ity, -ure, -ence, -ment, -ship and so on behind verbs or adjectives. The words such as approval, management and popularity are all formed this way.1) V erb+-ment, -al, -sion, -tion and -ageV+ment: argument, development, settlement.V+al: arrival, approval, betrayal.V+sion or tion: conclusion, diversion, expression, confusion.V+age: flowage, leakage, passage, shortage, stoppage.V+y: mastery, discovery, unity, entreaty, envy.2) Adjective +-ness, -dom, -hood, -ity, or –ty.Adj+ness: darkness, loneliness, effectiveness, hardness, goodness, illness.Adj+dom: wisdom, freedom, officialdom.Adj+hood: falsehood, likelihood, livelihood.Adj+ity or -ty: safety, ability, necessity, loyalty, acidity, activity, density.3) Adj or V erb+-th or -t, -ry, -cy, -ance(ancy) or –ency(ence)Adj or V +th or t: death, thought, growth, strength, truth,width.Adj or V +ry: bravery, distillery, finery, watery, inquiry, discovery.Adj or V +cy: accuracy, advocacy, intimacy, bankruptcy, secrecy.Adj or V +-ance(ancy) or –ence(ency): tolerance, absence, appearance, consistence, decency, reliance, continence, disturbance, reference, allowance, assistance.3.2Derivative Abstract NounsDerivative abstract nouns are those words derived from verbal phrases or prepositionsl phrases. The function of the two kinds of nouns is to give an abstract description that is similar to that of other abstract nouns. Also such derivative nouns contain meanings of abstraction or exaggeration. So they are called abstract nouns.a) His business takes a turn for the better. (improvement of something that already existsor that has gone before)b) Although it was well on in the evening, we decided to try our luck at fishing again. (tryto do or get something, hoping to succeed)4. Classification of Abstract NounsSimilarly, there are countable abstract nouns and uncountable ones. But in modern English, most of abstract nouns are uncountable ones, with some countable, and some both countable and uncountable.4.1 Countable Abstract NounsCountable abstract nouns not only have plural forms but also can be used with indefinite articles.a) It’s quite a task to figure out ten problems in an hour.b) There are a lot of heavy tasks for the young people to take upon themselves.a) Mr.Collinton had a narrow victory in the reform.b) We have to consolidate our victories in the reforms.a) Would you spare me a few minutes? I want to have a talk with you.b) The students enjoyed his talks on American cultureSometimes countable abstract nouns can be used as uncountable ones, but with their meanings changed.a) He’s all talk. (It means that he only talks but never takes action.)b) I took him to talk for his carelessness. (It means that I blamed him for his carelessness.)4.2Uncountable Abstract NounsThere are so many uncountable abstract nouns that here are only a few can be discussed.a) We’re sure of his honesty.b) She used to take some work home to do when she was a worker.c) His happiness defies utterance.d) She has made great progress in her studies.e) The Long March was of great historical significance.4.3 Meanings of Abstract NounsSome abstract nouns can be used either as countable nouns or uncountable ones, but with meanings changed. Here are some examples.a) He’s a professor of ten years’ experience. (knowledge or skill gained from doing something)b) Her tour by spaceship was quite an experience. (event or activity affecting one in some way)a) I’m always grateful to her kindness in helping me to tide over the difficulties. (good intention)b) They have done him a few personal kindnesses. (good deeds)a) Friendship first, competition second. (close relationship)b) His friendships never last very long. (behaviors that embody good relationship)a) Nowadays passengers have to be searched for security reasons. (Safety)b) Recently people like to trade in government securities. (bonds)Generally speaking, abstract nouns derived from countable single nouns usually have changed meanings. For example,a) There are three rooms in his flat. (shelters)b) There’s much room for discussion. (leeway)a) It is known that he is a fool. (stupid person)b) She was fool enough to believe him. (stupid person)a) They will live forever in our hearts. (minds)b) No matter what difficulties may come our way, we must never lose heart. (confidence)Broadly speaking, abstract nouns derived from verbs or adjectives usually keep their basic meanings. The examples are shown below.a) He held a position of importance when he was alive.b) It is important to have a good mastery of foreign language.a) Though he is only five, he is able to swim.b) We have confidence in their ability to resolve the problems.a) He approved himself an honest man.b) Don’t slightly express your approval or disapproval.a) This well delivers one thousand tons of oil a day.b) Y ou’re required to make delivery of the goods before June.From the above discussion, we can easily find that not every abstract noun is uncountable and it is better to consult the dictionaries when unfamiliar abstract nouns are met. Never take it for granted that abstract nouns always keep their meanings unchanged.5. Translation of Abstract NounsLanguages are a tool of expressing and communicating. Although different languages have much in common in expression ways and word usages, the existence of differences is very normal. There is no exception between English and Chinese. Mostly it depends on the translator whether the differences can be reduced to the minimum or not. Here is an old English saying: “Words have no meanings; people have meanings for the words.”（王敬群，2001）English word have connotations which are so broad that we must follow contexts to get their exact meanings especially for English abstract nouns. Some of them have their equivalent words in Chinese, such as “science”, “literature”, “friendship”, “phenomenon”, “art”, and so on. But most of them have no equivalents. In English reading materials, we often meet abstract nouns, of which we can only understand their meanings, but can’t say clearly the ir exact meanings in simple words in the target languages. So we often have trouble in understanding their abstract and conceptive meanings, which is usually the obstacle for translators. In order to express their meanings precisely and make them easier for the readers to understand, we should make painstaking efforts to research into abstract nouns to know their nature and characteristics so as to translate them correctly. Compared with English, Chinese is more concrete and plain. Therefore it is a better way to translate them into concrete and vivid Chinese words. The following are common ways for translation.5.1 Translating Abstract Nouns into Adjectives1) Abstract nouns derived from adjectives can often be translated into adjectives. This is an effective method to deal with the problem.a) The photo mask must possess dimensional stability.光掩模必须具有稳定的(stable)尺寸。
雅思听力机经词汇表
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现代大学英语中级写作课程教案精选版
现代大学英语中级写作课程教案Document serial number【KKGB-LBS98YT-BS8CB-BSUT-BST108】《现代大学英语中级写作》，徐克容，外语教学与研究出版社英语写作中级（上）课程教案I 授课题目：Unit One We Learn As We Grow一、教学目的、要求：（一）掌握：1、To learn the basics of exemplication:→ Definition→ Kinds of examples→ Sources of examples2、To learn to outline expositive essays知识点：→ The definition and introduction of exposition and essay.→Exposition is explanatory writing. It’s purpose is toexplain or clarify a point.→ An essay is a related group of paragraphs written for some purpose（二）熟悉:→ Practice the basics of exemplification→ Practice outlining知识点：→ Patterns of exposition, the choice of examples, the choice of appropriate examples, the organization of anexemplification essay:→Types of essays, basic structures of an expositive essay, elements of the expositive essay→ Types of outline, rules concerning outline（三）了解：→Patterns of exposition, types of essays, types of outlineprocess analysis, cause-effect analysis, Comparisonand contrast, classification, definition andanalogy， narrative essays, descriptive essays,expositive essays and argumentative essays二、教学重点及难点：重点：Exemplification, types of outline；难点：Sentence outline and topic outline三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第一课 Exemplification第一课Elements of the Essay: Outlining六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次：Read on the subject and write an example paper of 200-250 words on the given topic.第二次：Read on the subject and write an essay of 200-250 words on the given topic, using either a single extended example or two or three short ones to develop your thesis statement.第三次： Ask students to practice outlining八、课后小结：Emphasis on the writing procedure→ Prewriting-choosing a topic and exploring ideas→ Drafting: getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errorsII授课题目：Unit Two I Made It一、教学目的、要求：（一）掌握：1、To learn the basics of process analysis→ Definition→ Uses→ Types→ Methods2、To learn to write thesis statement知识点：→ The definiton and introduction of process analysis→ The function of process analysis→ The differences between thesis statement vs. topic sentence（二）熟悉:→ The areas the process analysis is usually used.知识点: → Functions of process analysis:giving instructions, giving information and giving the history→ Major types of process analysis: directive analysis, informative process analysis→ Writing an effective thesis statement（三）了解：The basics of process writing and thesis statement二、教学重点及难点：重点：Organization of a process paper, practice of effective thesis statement；难点：Guidelines on process analysis, writing effective thesis ststement三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第二课 Process Analysis第二课 Elements of the essay: The Thesis Statement六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次：Read on the subject and write an informative process paper describing how you succeeded in doing something第二次：Read on the subject and write a directive process paper telling first-year students how to adjust to life at college. 第三次：Ask students to practise writing the thesis statement八、课后小结：Emphasis on the writing procedure→ Prewriting-chossing a topic and exploring ideas→ Drafting:getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errors授课题目：Unit Three College Is Not a Paradise一、教学目的、要求：（一）掌握：1、To learn the basics of Cause-Effect analysis→ Definition→ Uses→ Patterns2、To learn to write an introduction to expositive essays→ What to include in the introduction→ How to write effective introduction知识点：→ The definiton and introduction of cause-effect analysis → The function of cause-effect analysis→ The writing of effective introduction（二）熟悉:→ The functions and areas the cause-effect analysis is usually used.知识点: → Functions of cause-effect analysis: explaining why certain things happen, analyzing what will happen as a result → Major types of cause-effect analysis: focusing on cause and focusing on effects,→ How to start and write effective introduction（三）了解： the basics of cause-effect analysis and writing effective introduction二、教学重点及难点：重点：How to focus on cause or effects, How to start and write effective introduction；难点：How to focus on cause or effects, How to start and write effective introduction三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第三课 Cause-Effect Analysis第三课 Parts of the essay: The Introduction六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次：Read on the subject and write an essay on any of the given topics analyzing cause.第二次：Read on the subject and write, from your own experience, an essay analyzing the effects of anthing taught in class.第三次：Ask students to practise writing the introduction八、课后小结：Emphasis on the writing procedure→ Prewriting- chossing a topic and exploring ideas→ Drafting: getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errors授课题目：Four What Makes the Differences一、教学目的、要求：（一）掌握：1、To learn the basics of Comparison and Contrast→ Definition→ Uses→ Patterns→ Methods2、To learn to develop the body of expositive essays→ What its structure looks like?→ What it includes知识点：→ The definiton and introduction of Comparison and Contrast → The function of cause-effect analysis→ The writing of effective introduction（二）熟悉:→ The functions and areas the comparison/contrast is usually used., the general structure of the body ofan essay知识点: → Functions of comparison/contrast: clarifying something unknown, bringing one or both of the subject intosharper shape→ Three patterns of comparison/contrast: subject bysubject, point by point, mixed sequence→ Familiarity of the general structure of the body of an essay（三）了解： The basics of Comparison and Contrast and the general structure of the body of an essay二、教学重点及难点：重点：Three patterns of comparison/contrast: subject by subject, point by point, mixed sequenceGeneral structure of the body: Beginning, Body and End难点： How to organize a comparison/contrast essay, How to develop body paragraphs三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第四课 Comparison/Contrast第四课 Parts of the essay: The Body六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次：Read on the subject and write a subject-by-subject essay of comparison/contraston any of the given topics第二次：Read on the subject and write a point -by-point essay of comparison/contraston any of the given topics第三次：Ask students to practise writing the body of the essay 八、课后小结：Emphasis on the writing procedure→ Prewriting-chossing a topic and exploring ideas→ Drafting:getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errors授课题目：Unit Five It Takes All Sorts to Make a World一、教学目的、要求：（一）掌握：1、To learn the basics of Classification→ Definition→ Uses→ Methods2、To learn to write the conclusion of expositive essays→ What is classification?→ What is classification used for?知识点：→ The definiton and introduction of classification→ The function of classification→ The writing of effective classification（二）熟悉:→ The functions and areas the classification is usually used., the conclusion of expositive essays知识点: → Functions of classification:To organize and perceive the world around usTo present a mass of material by means of some orderly systemTo deal with complex or abstract topics by breaking a broad subject into smaller, neatly sorted categories.→ The general pattern of classification→ sentence patterns in classification→ Familiarity of the the conclusion of expositive essays （三）了解： The functions and areas the classification is usually used., the conclusion of expositive essays二、教学重点及难点：重点：some sentence patterns in classificationthe conclusion of expositive essays难点： Parts of the conclusion: a summary of the main points, or restatements of your thesis in different work.三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第五课 classification第五课 Parts of the essay: The conclusion六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次：Read on the subject and write a classification essay on any of the given topics第二次：Write an essay of 200-250 words on any of the given topics. 第三次：Ask students to practise writing the conclusion of the essay 八、课后小结：Emphasis on the writing procedure→ Prewriting-chossing a topic and exploring ideas→ Drafting:getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errors授课题目：Unit Six What Does It Mean一、教学目的、要求：（一）掌握：1、To learn the basics of Definition→ Definition→ Types→ Methods of Organization2、To learn to write the title of expositive essays→ What is definiton→ Types of definition知识点：→ The Standard /Formal Definition→ The Connotative/Personal Definition→ The Extended Definition（二）熟悉:→ The functions and areas the definition is usuallyused., the title of expositive essays知识点: → Functions and patterns of definition:→ The Standard /Formal Definition is used to explain a term or concept your audience or reader may not know orunderstand,→ The Connotative/Personal Definition is used to explain any word or concept that doesn’t have the same meaningfor everyone.→ The Extended Definition is used to explore a topic by examining its various meanings and implications.（三）了解： How to write an extended definitionHow to organize an extended essay二、教学重点及难点：重点：Functions and patterns of definitionHow to write an extended definitionHow to write the title of an expositive essay难点：How to organize an extended essayHow to write the title of an expositive essay三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第六课 definition第六课 Parts of the essay: The Title六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次： Read on the subject and write a definition essay on any of the given topics第二次：Write an essay of 200-250 words on any of the given topics. 第三次：Ask students to practise writing the title of the essay八、课后小结：Emphasis on the writing procedure→ Prewriting- choosing a topic and exploring ideas→ Drafting: getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errorsUnit Six Task One DefinitionI What is definition?In talking with other people, we sometimes offer informal definitions to explain just what we mean by a particular term. That is, to avoid confusion or misunderstanding, we have to define a word, term, or concept which is unfamiliar to most readers or open to various interpretations.Suppose, for example, we say to a friend:” Forrest is really an inconsiderate person.” We might then explain what we mean by“ inconsiderate” by saying, “He borrowed my accounting book overnight but didn’t return it for a week. And when I got it back,it was covered with coffee stains.Definition is the explanation of the meaning of a word or concept, and it is also a method of developing an essay.II. The ways to define a word or termThere are three basic ways to define a word or termA. To give a synonym For example: ‘ To mend is to repair.” Or“ A fellow is a man or a boy.”B. To use a sentence (often with an attributive clause) For example,ink may be define in a sentence: “Ink is colored water which we use for writing.”C. To write a paragraph or even an essay But a synonymy or asentence cannot give a satisfactory definition of an abstract term whose meaning is complex. We have to write a paragraph or an essay with examples or negative examples (what the term does not mean),with analogies or comparisons, with classification or cause-effect analysis.III. When we give a definition, we should observe certain principles: 1.First, we should avoid circular definitions. “Democracy is thedemocratic process.” And “astronomer is one who studiesastronomy” are circular definition.2.Second, we should avoid long lists of synonyms if the term to bedefined is an abstract one. For example: By imagination, I meanthe power to form mental images of objects, the power to form new ideas, the gift of employing images in writing, and the tendency to attribute reality to unreal things, situations and states.(picking up words, expressions from a dictionary , in the hopethat one will hit)3.Third, we should avoid loaded definition, Loaded definitions donot explain terms but make an immediate appeal for emotionalapproval.A definition like:’ By state enterprise, I mean high cost andpoor efficiency.” is loaded with pejorative emotionalconnotation. Conversely, “ By state enterprise, I mean one ofthe great blessing of democratic planning” is loaded withfavorable emotional connotation. Such judgements can be vigorious to a discussion, but they lead to argument, not clarification,when offered as definition.IV. Types of definition1.Standard/ Formal definition---denotation is a word’s core, direct,and literal meaning.2.Connotative/Personal meaning---Explains what you mean by a certainterm or concept that could have different meanings for others.On the other hand, connotation is the implied, suggested meaning of a word; it refers to the emotional response stimulated byassociations the word carries with it.A.For Americans, Water gate is associated with a politicalscandal that means dishonesty. And more words are created with the suffix—gate to mean some scandal in English now, thus,Iran Gate, Intelligence GateB.Dogs, in Chinese culture, may be quite a negative image. It isinsulting to call someone a dog. What about the western people In their eyes, dog is lovely and has good associated meanings.They say “ Love me, love my dog.”C.Imperialism means to us Chinese quite negative. Some of thewestern people may be proud of being imperial and imperialismitself.D.People everywhere may also share some connotations for somewords. They are general connotations. Mother means love, care, selfless, etc.E.Let’s get the gang together for a party tonight. (a group)Don’t go around with that gang or you’ll come to no good.(degraded group of people or group of criminals)Connotation can make all the difference. It is the mirror ofyour attitude.3.Extended definition---is an essay length piece of writing usingthis method of development.V. How to write an extended definitionFollow 4 rules for a good definition:1. Don’t use the words “when “‘where”, giving a definition. A commonpractice is to define the noun with a noun, adjective with adjective and so on.2. Remember, that definition is not a repetition.3. Use simple and well- known term in your explanation.4. Point out the distinguishing features of the term.Unit Six Task Two: The TitleI.What is title?A title is a very brief summary of what your paper is about.It is often no more than several words. You may find it easierto write the title after you have completed your paper.A title may be a phrase which can indicate a topic ofinterest (i.e. your focus) and at the same time point towardsa particular kind of discussion (your mode of argument).Accordingly, your title needs not only to indicate what theessay will be about, but also to indicate the point of view itwill adopt concerning whatever it is about.II.The purpose of the titleTo give the reader an idea of what the essay is aboutTo provide focus for the essayTo arouse the reader’s interestIII.How to write a good titleMake it clear, concise and preciseUse a phrase rather than a sentenceExclude all extra wordsIV.Other rules to obeyCenter it at the top of the first page.Use no period at the end or quotation marksCapitalize the first and last wordsCapitalize all other words exceptarticles (a, the)the to in infinitivesprepositions containing one syllablecoordinating conjunctions (and, but, or, etc)A title leads, but a poor title misleads. Be sure that it is appropriate. Besides, be careful with the capitalization.Write an appropriate title for each of the introductory paragraphs that follow.1.Title: _____Reactions to Disappointment___________________Ben Franklin said that the only sure things in life are deathand taxes. He left something out, however: disappointment. Noone gets through life without experiencing many disappointments.Strangely, though, most people seem unprepared fordisappointment and react to it in negative ways. They feeldepressed or try to escape their troubles instead of usingdisappointments asan opportunity for growth.2.Title: ____Annoying People_____________________President Richard Nixon used to keep “enemies list” of all the people he didn’t especially like. Iam ashamed to confess it,butI, too, have an enemies list—a mental one. On this list are the people I would gladly live without , the ones who cause my blood pressure to rise to the boiling point. The top threeplaces on the list go to people with annoying nervous habits,people who talk in movie theatres, and people who talk on carphones while driving.3.Title: ___The Meaning of Maturity______________________Being a mature student does not mean being an old-timer.Maturity is not measured by the number of years a person havelived. Instead, the yardstick of maturity is marked by thequalities of self-denial, determination, and dependability.4.Title: _____College Stress____________________Jack’s heart pounds as he casts panicky looks around theclassroom. He doesn’t recognize the professor, he doesn’t know any of the students, and he can’t even figure out what thesubject is. In front of him is a test. At the last minute hisroommate awakens him. It’s only another anxiety dream. The very fact that dreams like Jack’s are common suggests that college is a stressful situation for young people. The cause of thisstress can be academic, financial, and personal.5.Title: __How to Complain_______________________I’m not just a consumer—I’m a victim. If I order a product, it is sure to arrive in the wrong color, sixe, or quantity. If I hire people to do repairs, they never arrive on the dayscheduled. If I owe a bill, the computer is bound to overcharge me. Therefore, in self-defense, I have developed the following consumer’s guide to complaining affectively授课题目：Unit Seven The Insight I Gained 一、教学目的、要求：（一）掌握：1、To learn the basics of Analogy→ Definition→ Uses→ Methods of Organization2、To learn to use transitions→ What is analogy→ The difference between analogy and comparison知识点：→ The field analogy is used→ The difference between analogy and comparison→ The patterns of analogy（二）熟悉:→ The functions and areas analogy is usually used., to learn to use transition知识点: → Functions and patterns of analogy:→ A comparison explains two obviously similar things and considers both their differences and similarities→ An analogy compares two apparently unlike things, and focus only on their major similarities→ An analogy is thus an extended metaphor—the figure of speech that declares one thing to be another（三）了解： How to organize an analogy by the way ---subject bysubjectHow to organize an analogy by the way—point by point 二、教学重点及难点：重点：Functions and patterns of definitionThe differences between comparison and analogyHow to learn to use transitionHow to organize an analogy by the way ---subject by subject How to organize an analogy by the way—point by point难点：How to learn to use transitionHow to organize an analogy by the way ---subject by subject How to organize an analogy by the way—point by point三、课时安排：共4课时四、授课方式：讲授、课堂快速阅读练习、课堂提问、写作实践讲解五、教学基本内容第六课 definition第六课 Parts of the essay: The Title六、参考书目：《英语写作手册》，《美国大学英语写作》七、作业和思考题：第一次： Read on the subject and write a definition essay on any of the given topics第二次：Write an essay of 200-250 words on any of the given topics. 第三次：Ask students to practise writing the title of the essay八、课后小结：Emphasis on the writing procedure→ Prewriting-chossing a topic and exploring ideas→ Drafting: getting your ideas on paper→ Revising: strengthening your essay→ Editing and proofreading: eliminating technical errors。
Abstract Classes and Interfaces抽象类与接口17页PPT
It is an artifact of the generalization process
Abstract Methods
Methods can also be abstracted
An abstract method is one to which a signature has been provided, but no implementation for that method is given. An Abstract method is a placeholder. It means that we declare that a method must exist, but there is no meaningful implementation for that methods within this class
Because of this, abstract classes cannot be instantiated
They act as place holders for abstraction
Abstract Class Example
In the following example, the subclasses represent objects taken from the problem domain.
Whatห้องสมุดไป่ตู้is an Abstract class?
Superclasses are created through the process called "generalization"
基于领域相关词汇提取的特征选择方法
收稿日期:2006-03-08 基金项目:国家自然科学基金项目(60305006)资助. 作者简介:孙 麟,男,1980年生,硕士研究生,主要研究方向为Web 信息挖掘;牛军钰,女,1973年生,博士,副教授,主要研究方向为多媒体信息智能处理.基于领域相关词汇提取的特征选择方法孙 麟,牛军钰(复旦大学计算机科学与工程系,上海200433)E-mail:jyniu@fu 摘 要:传统文本分类中的文档表示方法一般基于全文本(Bag -O f-W or ds)的分析,由于忽略了领域相关的语义特征,无法很好地应用于面向特定领域的文本分类任务.本文提出了一种基于语料库对比领域相关词汇提取的特征选择方法,结合SVM 分类器实现了适用于特定领域的文本分类系统,能轻松应用到各个领域.该系统在2005年文本检索会议(T REC,T ex t REtr iev al Confer ence )的基因领域文本分类任务(G eno mics T r ack Ca tego rizat ion T ask )的评测中取得第一名.关键词:文本分类;文档表示;特征选择;领域相关中图分类号:T P 311 文献标识码:A 文章编号:1000-1220(2007)05-0895-05Feature Selection Method Based on Domain -specific Term ExtractionSU N L in ,N IU Jun -yu(De p ar tment of Comp uter S cie nce and Eng ineering ,Fud an Univ ersity ,S hanghai 200433,C hina )Abstract :T he tr aditio nal tex t repr esentat ion methods fo r tex t classification ar e g enerally based o n the ana ly sis of full text (Bag -of -Wo rds).Because of ig nor ing dom ain-specific semantic featur es,they can no t fit do main-specific tex t classification.T his pa-per descr ibes a feature select ion metho d based o n dom ain -specific term ex tr actio n using co rpus co mpa riso n ,and a tex t classifi-ca tio n system based on the co mbina tio n of this method and the SV M classifier,w hich can be applied t o any do main ea sily.T his tex t classificatio n system go t t he hig hest sco re among r uns fr om 19g ro ups in the ev aluat ion o f T REC 2005G enomics T r ack Categ or izatio n T ask.Key words :tex t classificat ion ;do cument r epr esentatio n ;featur e selectio n ;domain -specific1 引 言文本分类任务是给文档分配一个预先定义好的类别.在这过程中,通常使用向量空间模型(V SM )表示文档.但是文本包含的词汇量越来越大,往往造成向量空间维数太多而显得过于稀疏.特征选择就是用来解决这一问题的方法之一[1-3],以Infor matio n Gain [4]、Chi -square [5,6]等基于概率统计理论的方法为代表,通过选择最合适特征子集来降低维度.然而这些方法无法体现语义层面信息,使得一般的文本分类系统无法很好地应用于需要语义支持的领域相关文本分类任务.虽然近年来出现了许多本体辞典可以提供语义支持,但本体词典有明显的弱点[7]:(1)本体辞典的构建费时费力,(2)无法收录新出现的词汇,(3)查辞典的过程会很大的降低系统性能,(4)会引入很多噪音,(5)难以覆盖所有领域,并且不同本体辞典语义层次和结构的不同,导致很难有统一的方法适用于不同领域,从而造成通用性差.为解决这些问题,Penas 等人提出通过对比语料库提取领域相关词汇[7-10],从而提供了一条提供语义支持的捷径.但是他们仅根据词频在不同语料库中的变化来选择领域相关词汇,忽略了语境的影响,降低了语义层面的意义.本文提出的基于领域相关词汇提取的特征选择方法,结合词的上下文语境解决这一问题.该方法根据词与词搭配的分布在不同语料库中的差异,选择领域相关词汇,进而用这些领域相关词汇及周围的词作为文档特征.这种特征选择方法结合SV M Light[11]分类器构造的文本分类系统,经过2005年文本检索会议基因领域文本分类任务[12](T REC 2005G e-no mics T r ack Categ or izatio n T ask)的评测,取得了第一名的好成绩[13].本文接下来将介绍这种基于领域相关词汇提取的特征选择方法,以及其与SV M 分类器结合的适用于特定领域的文本分类系统,并描述该系统在文本检索会议中的评测结果,最后对该特征选择方法及文本分类系统作出总结.2 基于领域相关词汇提取的特征选择方法人们阅读特定领域的文献时,常会对该领域相关的词汇非常关注,并且从这些词汇周围入手理解文献的大意.因此,我们作如下假设H 1.H1:与领域相关的文档特征出现在该领域相关词汇周围.基于这样的假设,本文提出了一种基于领域相关词汇提取的特征选择方法.该方法分为两个步骤:小型微型计算机系统Jour nal o f Chinese Computer Systems 2007年5月第5期V o l.28N o.52007 (1)通过对比语料库找出领域相关词汇.(2)以这些词汇为中心,选择其周围一定数量的词作为文档特征.2.1 基于语料库对比的领域相关词汇提取方法基于语料库对比的领域相关词汇提取方法的基本思想是,通过对比词的某种属性在某个特定领域的语料库以及包含很广泛领域的一般语料库中的差异,选择出这个特定领域语料库中与其领域相关的词汇.因此,首先要选择一个属于某特定领域的语料库作为领域相关词汇提取的研究对象A C (Analysis Co rpus),以及一个包含很广泛领域的语料库作为参照RC (Refer ence Cor pus ).然后,为每个出现在A C 中的词对比它的某些属性在这两个语料库中的差异,根据这种差异选择出A C 中与该特定领域相关的词汇.传统的基于语料库对比的领域相关词汇提取方法[7-10]主要是通过对比词的词频在不同语料库中的差异来选择领域相关词汇.以Penas 等人[7]为代表,他们通过对比词的词频在特定领域的语料库与一般领域的语料库中的差异,选择在特定领域的语料库中的领域相关词汇.然而这些方法均忽略了词的上下文语境.一般来讲,领域相关词汇不仅在词频方面存在差异,而且这种词汇在不同领域中所搭配的词通常会有很大的变化.如“disk ”若出现在餐饮领域,通常会与“china ”、“washer ”等词搭配形成“china disk ”、“disk washer "等二元词组;然而若在计算机领域,“disk "则通常与“har d ”、“dr iver "等词搭配形成“har d disk"、“disk dr iv er "等二元词组.因此,我们做如下假设H2.H2:某个词与其他词搭配的概率分布在不同领域中变化越大,则说明这个词与该领域越相关.对于那些只出现在A C 或RC 中的词,由于其缺乏可比性,因此不属于此算法研究对象.对于每个同时出现在AC 和RC 中的词ter m i ,若在A C 和R C 中总共有m i 个不同的词ter m j 连接在term i 后面,如图1所示,可以为ter m i 构造m i 维的Bi -gr am 向量空间模型,用来描述ter m i 在A C 、RC 中与这m i 个词的连接分布.图1 term i 在A C 和RC 中的Bi-gr am 向量VA 和VR F ig.1T he Bi-g ra m vecto r V A and V R o f ter m i in A C and RC V A 、V R 是两个m i 维向量,分别描述ter m i 在A C 、RC 中与这m i 个词的搭配分布,称之为Bi -g r am 向量.Bi -g ra m 向量的每个分量表示以ter m i 开头ter m j (j =1,2,…,m i )结尾的Bi -gr am 词组在相应语料库中出现的次数(phr ase fr equency),用p f ij A 表示该词组在A C 中出现的次数,用p f ij R 表示该词组在RC 中出现的次数.若该词组未在某个语料库中出现,则在对应于这个语料库的向量的相应的分量上的值为0.基于这个向量空间模型,我们可以构造一个用于计算term i 在AC 所属的领域中的特殊性(Speciality i )公式F 1. F1:Sp eciality i =S Ai S Ri S A i=∑m ij =1pf A ij tf R i -1m iS R i=∑m ij =1pf R ijtf A i -1m iF1:计算ter m i 在AC 所属的领域中的特殊性(Speciali-t y i )的公式Sp eciality i 表示t erm i 在AC 所属的领域中的特殊性,tf i A 为term i 在AC 中的词频,tf i R为ter m i 在RC 中的词频,m i =0的词被忽略了,S i R =0且S i A ≠0的词的Speciality i设为-1.根据公式F 1,Speciality 分数高的词被选出来作为AC 的领域相关词汇.表1列出了根据此公式得出的Specialit y 分数最高的词语,这些词经过了Po rt er Stemmer 的取词干的处理.表1 按照Speciality 分数排列,得分最高的20个词T able 1T he 20to p -ranked w o rds acco rdingto the sco re o f specialityNo TermNo T erm 1phosph or yl 11upregul 2overex pres s 12term inu 3tyros in 13his ton4isofor m 14su bcellu lar 5exon 15stain 6cleavag 16endoth 7down regul 17cytos ol 8plasmid 18repres s9fulllength 19transmembran 10fibr ob last20bead2.2 基于领域相关词汇提取的文档特征选择基于假设H1,领域相关词汇周围一般存在着与文档及该领域密切相关的特征.而远离这些词汇的词语、语句、甚至段落谈论与领域相关话题的可能性较小.因此,在得到语料库中的领域相关词汇之后,则选取这些词汇为中心一定长度的窗口内的词作为文档特征.根据选择领域相关词汇的多少以及窗口的大小,可以产生不同的特征集.若这些词汇太多或者窗口长度太大,则有可能包含了文档内大部分或全部内容;若这些词汇太少或窗口长度太小,则有可能使特征数量太少.这两种情况都会使文档表示的质量降低.因此,要选取合适的领域相关词汇数量以及窗口大小.2.3 特征选择系统框架896 小 型 微 型 计 算 机 系 统 2007年在特征选择部分,系统的输入是语料库中的原始文档,输出是SV M Light 输入格式的特征文件.首先为A C 和RC 分别使用相应的解析器将其原始语料转化为纯文本格式文档,其中,使用了P or ter St emmer ,将同一个词的不同形态转化为统一图2 特征选择系统框架图Fig.2T he fr amew or k of featur e selectio n sy stem 的词干形式,并去除了纯数字和小数.然后计算出A C 中的领域相关词汇,最后选择这些词汇周围的词作为文档特征.图2显示了特征选择部分的系统框架.3 实验及评测为了评测这种特征选择方法,我们将它与SV M L ig ht 分类器结合,参加了2005年文本检索会议基因领域文本分类任务(T REC 2005Genomics T rack Categ or izatio n T ask)的评测.3.1 任务介绍该任务由2004年文本检索会议基因领域文本分类任务的T r iag e 子任务衍生而来[14](T R EC 2004Genomics T r ack Categ or izatio n T ask T r iag e Subt ask),包含4个子任务,各个子任务的目标是在语料库中分别找出属于A lleles of m ut ant pheno types(A 类)、Embry olog ic gene ex pressio n(E 类)、G Oanno tation (G 类)、和T umor bio lo gy (T 类)这4种类型中一种类型的文档.使用的语料库是由Hig hwire P ress 提供的生物化学领域的三个杂志2002年和2003年这两年内总共11880篇全文本文章组成的:Jour nal o f Bio lo gical Chemistr y (JBC ),Jo urnal o f Cell Biolog y (JCB),以及P ro ceeding s o f the Nat ional A cadem y o f Science (PN A S).这些全文本文档的格式为基于Hig hw ir e 文档类型定义(DT D )的SG M L 格式.以2002年的文章作为训练集,2003年的文章作为测试集.3.2 评测标准文本检索会议基因领域文本分类任务使用U t ility 作为各个子任务的评测标准,这种评测标准常被用于文本分类任务中,并且在以前的文本检索会议的过滤项目中也用到过.在这里使用的是正规化了的U tility ,F 2是其计算公式. U norm =U raw /U max U raw =(u r *T P )-FP U max =U r *A P u r =A N /A P F2:正规化了的U tility 其中: T P 表示分类结果的正例中本身就是正例的数量, FP 表示分类结果的正例中本身是负例的数量, AN 表示所有负例的数量,A P 表示所有正例的数量.表2 各个任务的u r 值以及正负例数量T able 2T he v alue o f u r and the po sitiv e&neg ative samples distr ibutio n子任务APAN u r 总u r A 类训练338549916.27测试332571117.2017E 类训练81575671.06测试105593856.5564G 类训练462537511.63测试518552510.6711T 类训练365801161.14测试206023301.15231如表2所示,由于各个子任务的A P 及A N 不同,使得他们的U r 值不一样.3.3 语料库的选择在实验中,A C 使用的是用于文本检索会议基因领域文本分类任务的语料库.对于RC 的选择应该使其包含尽可能广泛的领域.这里则使用的是用于文本检索会议网络检索项目(T R EC W eb T r ack )的.GO V 语料库.该语料库抓取了2002年早期的.go v 网站中1247753篇文档,其中包括1053372篇tex t/html 格式的文档,总大小为18.1G,其中包含了相当广泛的领域.为了简化在对比中语料库大小所产生的影响,我们使用了.GO V 语料库中与A C 大小相当的一个子集.3.4 分类系统介绍结合SV M L ig ht 分类器,我们为该评测任务构建了文本分类系统.如图3所示,将特征选择部分处理得到的特征文件送给分类器做分类,并输出分类结果.SV M Lig ht 的参数则使用Fujita [15]在2004年T REC Geno mics 项目T r iag e 任务中得到的最佳参数,即C =0.0001505、J =u r .如上所述,根据选择的领域相关词汇数量以及窗口大小的不同,会产生不同的特征集,需要通过学习来选择合适的领域相关词汇数量以及窗口的大小.因此,在学习阶段,我们将训练语料拆分为对等的两半,分别包含相同数目的正例和负例,用其中一半作训练,另一半做测试,使用在两半上测试结果的平均作为最终测试结果,用来比较特征集的优劣,从而选择出表现最好的特征集.我们还尝试了将领域相关词汇列表中分数最低的词添加为禁用词,然而,添加禁用词的方法在学习阶段并没有显示出很好的性能.8975期 孙 麟等:基于领域相关词汇提取的特征选择方法 图3 分类系统框架图F ig.3T he framew o rk o f the classification system共有两组基于此分类系统的运行结果M ar sI和M arsII 参加了评测.对于每个子任务,分别选择表现最好的特征集,表3 两组运行结果的各项参数T a ble3T he par ameter of t he t wo submit ted r uns领域相关词汇数量窗口大小是否添加禁用词M ar sI A20004否E5002否G20004否T25000以及分数为-1的词0是M arsII5002否经运算后结果组成了M a rsI.而M a rsII则是由同一个特征集运行出来的结果组成,该特征集对于所有子任务的测试结果的平均值最高.表3详细列出了这两组运行结果的各项参数.3.5 评测结果表4列出了这两组运行结果的评测结果.表4 评测结果T a ble4T he evaluatio n scor es of the sy st em sP:精确率,R:召回率,NU:正规化了的Utility2005年共有19个组织参加了该任务的评测,其中包括IBM的三个研究机构和U IU C、韦斯康星大学、加州州立San M arco s大学、Q ueen s大学、清华大学、复旦大学、大连理工大学、香港中文大学、国立台湾大学等院校.我们的系统取得表5 我们最好的成绩在所有评测成绩中的位置T able5Fudan W IM s best r esult andits rank in the T R EC 05geno mics最高中等最低我们最好的组参评总数A0.87100.77850.20090.843948E0.87110.6548-0.00740.871146G0.58700.4575-0.03420.587047T0.94330.76100.04130.915451了E类第一、G类第一、T类第三、A类第五的评测成绩.表5显示了我们的最好评测成绩在所有评测成绩中的位置.4 结 论实验结果表明,选取少量的领域相关词汇以及较小的窗口较适合.领域相关词汇数量定为500、窗口大小定为2时取得了较好的分类效果.但是,将领域相关词汇列表中分数最低的词添加到禁用词表的做法并未取得很好的效果,这说明这种领域相关词汇提取的方法并不适用于选取禁用词.从T REC的评测的结果来看,这种通过对比语料库提取领域相关词汇提取的特征选择方法可以很好地适用于领域相关的文本分类任务.它不仅提炼出了领域相关的特征,而且克服了那些依赖本体辞典的特征选择方法的不足,同时能够轻松的应用到不同领域.在今后的工作中,我们将进行以下研究:(1)与本体辞典的结合,(2)自动构造本体辞典,(3)挖掘领域相关词汇之间的关系.References:[1]Ron Kohavi,George H John.Wrappers for feature subs et selec-tion[C].In:Artificial Intellig ence,1997,97(1-2):273-324. [2]Avrim L Blum,Pat Langley.S election of relevant featu res andexamp les in mach ine learning[C].In:AAAI Fall Symposiu m on Relevan ce,1994,140-144.[3]Yang Yi-ming,Jan O Pedersen.A comparative study on featu res election in text categorization[C].In:Proceedings of14th In-tern ational Conference on M ach ine Learnin g,1997,412-420. [4]Lew is D D,Ringuette parison of tw o learning algo-rithms for tex t categoriz ation[C].In:Proceedings of the T hird Annu al S ymposium on Documen t Analys is and Information Re-trieval,1994.[5]W iener E,Pedersen J O,W eigend A S.A neural network ap-proach to topic spotting[C].In:Proceedings of the Fourth An-nual S ymposiu m on Document Analys is and In formation Re-898 小 型 微 型 计 算 机 系 统 2007年trieval,1995,317-332.[6]Sch utze H,Hull D A,Peders en J O.A com paris on of class ifiersand docu ment rep resentations for th e routing p roblem[C].In: 18th Ann Int ACM SIGIR Conference on Research and Develop-m ent in Information Retrieval,1995,229-237.[7]Penas A,V erdejo F,Gonzalo J,et al.Corpus-bas ed terminolo-gy extraction applied to information acces s[C].In:Pr oceedings of Corpus Lingu istics,2001.[8]David in g generic corpora to learn d om ain-s pecific ter-min ology[C].In:Proceedin gs of T he Ninth ACM SIGKDD In-ternational Conference on Know ledge Dis covery and Data M in-ing,2003.[9]T eresa M ihw a Chung.A corp us comparison approach for termi-nology ex tr action[J].T er minology,2003,(9):221-246. [10]Patrick Dr ou in.Detection of d om ain s pecific termin ology usingcorpora comp aris on[C].In:Proceedings of the Fourth Interna-tional Conference on L angu age Res ou rces and Evaluation (LREC),Lis bon,Portug al,2004.[11]Joachims T.M aking large-Scale SVM L earning Practical.Ad-vances in Kern el M ethods-Su pport Vector L earning, B.Sch olkopf and C.Burges and A.Smola(ed.)[M].M IT-Pres s,1999.[12]W illiam Hers h.TREC2005genomics track overview[C].In:14th T ext Retrieval Conference,2005.To appear.[13]Niu Jun-yu,Su n L in,et al.W IM at TREC2005[C].In:14thText Retrieval Conference,2005.T o appear.[14]W illiam Hers h.TREC2004genomics track overview[C].In:13th T ext Retrieval Conference,2004.[15]Fu jita S.Revis itin g again docum ent len gth hyp otheses TREC2004gen om ics track experiments at patolis[C].In:13th T ext Retrieval C on feren ce,2004.2007年全国软件与应用学术会议征文(NASAC 07)全国软件与应用学术会议(NA SA C)由中国计算机学会系统软件专业委员会和软件工程专业委员会联合主办,是中国计算机软件领域一项重要的学术交流活动.第六届全国软件与应用学术会议N A SAC2007将由西安交通大学计算机系承办,于2007年9月20日至22日在陕西西安举行.此次会议将由国内核心刊物(计算机科学)以增刊形式出版会议论文集,还将选择部分优秀论文推荐到核心学术刊物(EI检索源)发表,并将评选优秀学生论文.欢迎踊跃投稿.一、征文范围(但不限于下列内容) 1.需求工程2.构件技术与软件复用3.面向对象与软件A g ent4.软件体系结构与设计模式5.软件开发方法及自动化6.软件过程管理与改进7.软件质量、测试与验证8.软件再工程9.软件工具与环境10.软件理论与形式化方法11.操作系统12.软件中间件与应用集成13.分布式系统及应用14.软件语言与编译15.软件标准与规范16.软件技术教育17.计算机应用软件二、论文要求1.论文必须未在杂志和会议上发表和录用过.2.论文篇幅限定6页(A4纸)内.3.会议只接受电子文档P DF或PS格式提交论文.排版格式请访问会议网址.(htt p://na )4.投稿方式:采用“N A SAC2007在线投稿系统”(http://nasac07.x jt )投稿(待建).三、重要日期1.论文投稿截止日期:2007年5月31日2.论文录用通知日期:2007年6月30日3.学术会议及活动日期:2007年9月20日至22日四、联系方式联系人:王换招、张华,西安交通大学计算机科学与技术系T el:029-********Email:csed@ma il.x 更详细的内容请访问N A SA C2007网址:http://nasac07.x 8995期 孙 麟等:基于领域相关词汇提取的特征选择方法 。
文献检索习题及答案(工大版)
文献检索课综合检索（作业）姓名__ ____班级__ ____学号________试题一：Scifinder Scholar数据库是什么类型的数据库？简述Scifinder Scholar数据库的基本检索方法。
答：（1）SciFinder Scholar是由美国化学学会(ACS)旗下的化学文摘服务社CAS (Chemical Abstract Service)所出版的网络版数据库，是全世界最大、最全面的化学化工及其相关领域的学术信息数据库。
(2)检索方法：主要分为Explore、Locate和Browse三种检索方式<1> Explore（搜索科技文献）：分为Explore Literature、Explore Reactions和Explore Substances三大部分：1) Explore Literature（搜索文献）：可按照Research Topic（研究主题）、Author Name（作者姓名）和Company Name/Organization（单位名称）三大途径进行检索。
2) Explore Reactions（搜索反应）：可通过画出反应途径查找特定的反应过程。
3) Explore Substances（搜索物质）：可通过画出Chemical Structure（化学结构）或输入MolecularFormular（分子式）来查找化学物质。
<2> Locate（查找特定的文献或物质）：分为Locate Literature和Locate Substance两大部分：1) Locate Literature（定位文献）：可按照Bibliographic Information（文献著录信息：作者姓名、期刊名、文献题名或专利号）以及Document Identifier（文献：专利号或标识号CA文摘号）进行特定文献的检索。
2) Locate Substance（定位物质）：按照Substance Identifier（物质标识号：化学名称、CAS登记号）查找特定的化学物质。
Abstract
1
Int roduct
ion
This paper studies the problem of constructing simplicial complexes that represent or approximate a geometric object in some finite-dimensional Euclidean space, Rd. We refer to the geometric object as a topological space or subspace of Rd. This problem arises in geometric modeling and finite element analysis, and it is a special case of the grid generation problem [21]. It is special because we only consider grids or complexes made up of simplices. The problem can be divided into two questions: How do we choose the points or vertices of the grid? How do we connect the vertices using edges, triangles, and higher-dimensional simplices?
in a non-empty set. By the nerve theorem, ~Dx and X are homotopy equivalent if all such sets are contractible.
英语论文摘要应该如何写？How-to-Write-Abstract？
STRUCTURE of Abstract
Classification of abstracts Structure of an informative abstract Features of an abstract
Structure of abstract | Classification of abstracts
(participants/materials)
To DESCRIBE research method and procedures
Detailed information has been acquired by the authors using.. Several sets of experiments have been performed to test the validity of… The technique the author adopted is referred to as… The experiments consisted of four steps, which are described in… The method/approach used in the present study is… The experiment/investigation in the paper is conducted by adopting… The procedure the present study followed can be briefly described as… The experiment/study consisted of the following steps: … Included in the experiment were… Based on the idea that…, we conducted the present study, categorized…, and evaluated…
基于自适应权重的多重稀疏表示分类算法_段刚龙_魏龙_李妮
网络出版时间：2012-08-16 10:45网络出版地址：/kcms/detail/11.2127.TP.20120816.1045.019.htmlComputer Engineering and Applications计算机工程与应用基于自适应权重的多重稀疏表示分类算法段刚龙, 魏龙, 李妮DUAN Ganglong, WEI Long, LI Ni西安理工大学信息管理系, 陕西西安 710048Department of Information Management, Xi’an University of Technology, Xi’an 710048, ChinaAdaptive weighted multiple sparse representation classification approach Abstract：An adaptive weighted multiple sparse representation classification method is proposed in this paper. To address the weak discriminative power of the conventional SRC (sparse representation classifier) method which uses a single feature representation, we propose using multiple features to represent each sample and construct multiple feature sub-dictionaries for classification. To reflect the different importance and discriminative power of each feature, we present an adaptive weighted method to linearly combine different feature representations for classification. Experimental results demonstrate the effectiveness of our proposed method and better classification accuracy can be obtained than the conventional SRC method.Key words：adaptive weight; multiple sparse representation; SRC摘要：提出了一种基于多特征字典的稀疏表示算法。
《最蓝的眼睛》中边缘人形象分析
中文摘要托尼·莫里森是美国著名的黑人女作家，也是第一位获得诺贝尔文学奖的黑人女作家。
《最蓝的眼睛》作为莫里森的第一部作品，一经出版就赢得了广泛的关注与讨论。
该书将视角投向了处于社会边缘地带的黑人家庭，塑造了布里德洛夫一家三口不同层面的边缘化人物形象。
这些鲜明的人物形象是社会主流意识形态下边缘群体的缩影。
本文试图运用美国边缘人理论来分析小说黑人家庭中父亲乔利，母亲宝林，女儿佩克拉三者在道德，文化，及精神方面的边缘人形象，试图挖掘三种边缘人形象的成因及表现，探讨在恶劣环境下边缘人人性的发展与心理危机，总结其小说创作的艺术价值与意义。
小说描述了三个黑人家庭成员在白人主流文化下产生的不同层面的边缘人形象。
作为道德的边缘人，黑人父亲乔利从小被抛弃，年少时期道德标杆的缺失造成了他是非观念的空白。
来自白人世界的侮辱造成了他极端的自卑心理，后期黑人社会与其家庭的冷漠更是加剧了他道德意识的沦丧和善恶观念的扭曲。
在酒精的作用下，乔利完全沦为了本能和欲望的野兽。
他性侵了自己的女儿，虐待自己的妻子，最终从无能的受害者彻底沦为道德败坏的施害者。
作为文化的边缘人，黑人母亲宝林毅然决然地抛弃了自己的黑人家庭，主动切断了同黑人文化的联系并极度向往和推崇白人文化。
但是因为种族歧视，宝林却始终无法得到白人主流文化的认可。
即使宝林主动迎合白人文化标准，接受白人的审美观念，但是她的存在价值仅仅只是附属品女仆身份，最终宝林沦为了不黑不白的文化边缘人。
年仅11岁的黑人女孩佩克拉从心智正常的失语者沦为了精神边缘的疯子，走向了精神世界的边缘化。
破裂的家庭环境的忽视，学校师生的歧视及社会环境的冷漠造成了佩克拉精神的崩溃，人格的分裂。
因此她疯狂盲目地追求所谓的蓝色眼睛，最终丧失了理性思维，走向了精神层面的癫狂。
本文通过对三种边缘人类型及特征的划分，总结不同角色因种族，文化，性别对其边缘人形象形成的原因，揭示了莫里森对弱势的边缘黑人人性的挖掘，传递了莫里森对弱势边缘黑人命运的悲悯及关怀。
人脸识别的英文文献15篇
人脸识别的英文文献15篇英文回答：1. Title: A Survey on Face Recognition Algorithms.Abstract: Face recognition is a challenging task in computer vision due to variations in illumination, pose, expression, and occlusion. This survey provides a comprehensive overview of the state-of-the-art face recognition algorithms, including traditional methods like Eigenfaces and Fisherfaces, and deep learning-based methods such as Convolutional Neural Networks (CNNs).2. Title: Face Recognition using Deep Learning: A Literature Review.Abstract: Deep learning has revolutionized the field of face recognition, leading to significant improvements in accuracy and robustness. This literature review presents an in-depth analysis of various deep learning architecturesand techniques used for face recognition, highlighting their strengths and limitations.3. Title: Real-Time Face Recognition: A Comprehensive Review.Abstract: Real-time face recognition is essential for various applications such as surveillance, access control, and biometrics. This review surveys the recent advances in real-time face recognition algorithms, with a focus on computational efficiency, accuracy, and scalability.4. Title: Facial Expression Recognition: A Comprehensive Survey.Abstract: Facial expression recognition plays a significant role in human-computer interaction and emotion analysis. This survey presents a comprehensive overview of facial expression recognition techniques, including traditional approaches and deep learning-based methods.5. Title: Age Estimation from Facial Images: A Review.Abstract: Age estimation from facial images has applications in various fields, such as law enforcement, forensics, and healthcare. This review surveys the existing age estimation methods, including both supervised and unsupervised learning approaches.6. Title: Face Detection: A Literature Review.Abstract: Face detection is a fundamental task in computer vision, serving as a prerequisite for face recognition and other facial analysis applications. This review presents an overview of face detection techniques, from traditional methods to deep learning-based approaches.7. Title: Gender Classification from Facial Images: A Survey.Abstract: Gender classification from facial imagesis a widely studied problem with applications in gender-specific marketing, surveillance, and security. This surveyprovides an overview of gender classification methods, including both traditional and deep learning-based approaches.8. Title: Facial Keypoint Detection: A Comprehensive Review.Abstract: Facial keypoint detection is a crucialstep in face analysis, providing valuable information about facial structure. This review surveys facial keypoint detection methods, including traditional approaches anddeep learning-based algorithms.9. Title: Face Tracking: A Survey.Abstract: Face tracking is vital for real-time applications such as video surveillance and facial animation. This survey presents an overview of facetracking techniques, including both model-based andfeature-based approaches.10. Title: Facial Emotion Analysis: A Literature Review.Abstract: Facial emotion analysis has become increasingly important in various applications, including affective computing, human-computer interaction, and surveillance. This literature review provides a comprehensive overview of facial emotion analysis techniques, from traditional methods to deep learning-based approaches.11. Title: Deep Learning for Face Recognition: A Comprehensive Guide.Abstract: Deep learning has emerged as a powerful technique for face recognition, achieving state-of-the-art results. This guide provides a comprehensive overview of deep learning architectures and techniques used for face recognition, including Convolutional Neural Networks (CNNs) and Deep Residual Networks (ResNets).12. Title: Face Recognition with Transfer Learning: A Survey.Abstract: Transfer learning has become a popular technique for accelerating the training of deep learning models. This survey presents an overview of transferlearning approaches used for face recognition, highlighting their advantages and limitations.13. Title: Domain Adaptation for Face Recognition: A Comprehensive Review.Abstract: Domain adaptation is essential foradapting face recognition models to new domains withdifferent characteristics. This review surveys various domain adaptation techniques used for face recognition, including adversarial learning and self-supervised learning.14. Title: Privacy-Preserving Face Recognition: A Comprehensive Guide.Abstract: Privacy concerns have arisen with the widespread use of face recognition technology. This guide provides an overview of privacy-preserving face recognition techniques, including anonymization, encryption, anddifferential privacy.15. Title: The Ethical and Social Implications of Face Recognition Technology.Abstract: The use of face recognition technology has raised ethical and social concerns. This paper explores the potential risks and benefits of face recognition technology, and discusses the implications for society.中文回答：1. 题目，人脸识别算法综述。
英语的主题结构分类及其翻译_主题句
英语的主题结构分类及其翻译_主题句Topic Structure Classification and Translation of English Thesis Main SentencesAbstract: This research paper discusses the topic structure classification and translation of English thesis main sentences. It first provides an overview of the different types of English sentence structures, such as simple sentences, compound sentences, complex sentences, and compound-complex sentences. Next, it examines the translation process of English main sentences. Finally, it provides a discussion about the relative difficulties of translations with different sentence structures.Keywords: English thesis sentence, topic structure classification, translation processMain Text:English thesis sentence consists of different types of sentence structure. The sentence structures include simple sentence, compound sentence, complex sentence and compound-complex sentence. A simple sentence has one independent clause. A compound sentence has two or more independent clauses. A complex sentence has one independent clause and one or more dependent clauses. A compound-complex sentence has two or more independent clauses and one or more dependent clauses.The translation process of English main sentences is complicated. It is because the context and meaning of the sentence should be carefully interpreted. In addition, words and phrases in the sentence have to be appropriately translated. Therefore, translatorshave to have a deep understanding of the source language and the target language.Different types of English sentence structures have their own complexities in translation. Simple sentences are usually easy to understand and therefore can be easily translated. However, compound sentences are harder since they contain multiple clauses that need to be carefully identified and translated. Complex sentences are even more difficult as they contain both independent and dependent clauses, meaning that all components of the sentence need to be accurately rendered in the target language. Compound-complex sentences are even more difficult as they require a great attention to detail in order to convey the same meaning, nuance, and tone as the original.In conclusion, English thesis main sentences require a thorough understanding of the language and the context of the sentence in order to be effectively translated. The difficulty of the translation process will vary depending on the type of sentence structure used. Simple sentences are usually the easiest to translate while compound-complex sentences are the most difficult. translators.English thesis sentences can be used in a variety of applications. For example, they can be used to effectively convey ideas in academic writing, such as in research papers, essays and dissertations. They can also be used to express complex concepts in business documents, such as in contracts, legal documents and marketing material. In addition, English thesis sentences are often used in communication, both formal and informal. This includes letters, emails, presentations and conversations.Overall, the use of English thesis sentences depends on the application and the audience. For example, if the goal is to communicate a complex concept with clarity to an educated audience, then suitably constructed thesis sentences should be used. However, if the goal is to communicate with simplicity to a less informed audience, then simpler sentence constructions should be used. No matter what the goal is, having an understanding of the proper sentence structure can help ensure effective communication.Besides the applications mentioned above, English thesis sentences are also used in creative writing. Authors of novels and short stories use thesis sentences to convey key themes and ideas, create suspense and build tension. Moreover, thesis sentences can be used as an effective tool for poetic expression, with authors using them to craft powerful imagery and convey abstract concepts.In addition, English thesis sentences can be used to analyze data and draw conclusions. For example, in data-driven analytics, professionals use thesis sentences to construct meaningful statements based on the analysis of datasets. Similarly, newspaper articles often contain thesis sentences that summarize the main points of the article and offer a thought-provoking conclusion.In conclusion, English thesis sentences have a variety of uses and applications. They can be used to effectively communicate ideas, analyze data and draw conclusions, and to create powerful imagery and emotion. No matter what the application, understanding the different types of sentence structures can help ensure effective communication and interpretation.Finally, English thesis sentences can be used to express opinions. Opinion-based writing, such as inthe form of editorials, often relies heavily on well-crafted thesis sentences to establish an argument and to make a point. Similarly, professionals use them to be persuasive in business documents, such as client proposals, reports and presentations.The effectiveness of any opinion based writing rests largely on the ability of the author to construct meaningful sentences that are logically sound and clearly express their point of view. While a simple sentence may suffice, it is often necessary to construct a more complex sentence structure in order to make a stronger argument. Careful construction of English thesis sentences therefore becomes an essential skill for all opinion writers.In conclusion, English thesis sentences are a powerful tool applicable to a wide range of applications. They can be used to communicate ideas and convey emotions, analyze data and draw conclusions, and to express opinions. Understanding different types of sentence structures can help ensure effective communication no matter what the application is.Moreover, English thesis sentences are also used to develop creative thinking skills. In classrooms, students can use them to brainstorm ideas and structure their thoughts. By working with thesis sentences, students can develop an understanding of how to use language effectively while practicing the fundamentals of grammar and syntax. Furthermore, thesis sentences can be used in problem-solving, allowing individuals to break down complex problems into smaller, more manageable chunks. Using sentence structure to define the scope of the problem and to identify possible solutions can help improve reasoning skills and provide direction in problem-solving.In conclusion, English thesis sentences serve a variety of purposes in education, communication, and problem-solving. They can be used to communicate effectively, to analyze data and draw conclusions, and to express opinions. Moreover, they can be used to practice grammar and syntax, develop creative thinking skills, and to provide structure to problem-solving. Understanding different types of sentence structures is an essential skill for anyone who wishes to be an effective communicator and thinker.Finally, English thesis sentences are also used in public speaking. To be a good public speaker, one must be able to effectively communicate and convey their message in a logical and organized manner. Thesis sentences can provide structure to help speakers organize their thoughts and create an outline for the speech. They can also be used to emphasize key points or to introduce a new idea.In addition, thesis sentences can also help build rapport with an audience by creating a shared understanding of the topic at hand. A well-crafted thesis sentence can ensure that the audience is on the same page as the speaker, creating a more effective communication experience.In conclusion, English thesis sentences are an essential tool to have when engaging in public speaking. They can provide structure to help structure thoughts and ideas, emphasize key points and create rapport with the audience. Understanding how to construct meaningful sentences is therefore an essential skill for anyone who wishes to be an effective communicator.All in all, English thesis sentences are an essential tool for any communication situation.They can be used to effectively communicate ideas, analyze data and draw conclusions, express opinions, develop creative thinking skills, and to provide structure for public speaking. Understanding different types of sentence structures is therefore essential for anyone who wishes to communicate effectively.To effectively use English thesis sentences, it is important to understand the purpose and context of each type of sentence. Different sentence structures can have different implications and meanings, so the purpose and context should always be taken into consideration before crafting a thesis sentence. Additionally, content should always be kept in mind when constructing thesis sentences, as one must ensure that the sentence expresses the idea or point of view as accurately and clearly as possible.。
Literature,Review,of,Prefabricated,Chunks
Literature,Review,of,Prefabricated,Chunks おお作者简介：何微微（1980-），女，汉族，四川自贡人，助教，硕士，主要从事应用语言学、英语教学法研究。
Abstract：This article provides an overview of the research on prefabricated chunks both at home and abroad.It describes the definition of prefabricated chunks，its classifications，and the related research in this field.This paper emphasizes that the application of prefabricated chunks has important implications to English teaching and learning in China.Key words：prefabricated chunks；definition；classifications；SLA researchオ1.IntroductionIn recent years，the role of prefabricated chunks in language teaching and learning has been in the focus of attention of many language teachers and researchers.The ever awareness of prefabricated chunks in native-speaker performance leads to rethinking the approaches to language teaching and learning.Prefabricated chunks are language units which exit with high frequency in language.They are composites of grammar，semantics and pragmatics.They play a vital role in everyday communication，contributing to the ease，fluency and appropriateness in listening，speaking，reading and writing.Therefore，teaching prefabricated chunks is a new language pedagogical theory，and it is based on the rationale that language consists not of traditional grammar and vocabulary but often of multi-word prefabricated chunks.2.The definition of prefabricated chunksAttempts have been made to explore the phenomenon of prefabricated chunks in both first and second language acquisition.The particular language is characterized with“ready-made”or“unanalyzed whole”.Different commentators use overlapping terms to describe this phenomenon，such as prefabricated chunks（Becker，1975&Bolinger，1976），formulaic utterances （Fillmore Wong，1976），formulaic speech（Ellis，1985），routine formulas （Yorio，1980），lexical chunks（Michael Lewis，1993），formulaic expression （Fillmore Wong，1976），speech formulas（Peters，1977）.However，no coherent term and definition have yet emerged.Many applied linguists have tried to define prefabricated chunks.The following are some important ones：Concerning the prefabricated chunks，Lyons（1968）paid attention to the phenomenon of formulaicity and described it as“expressions which are learned as unanalyable wholes and employed on particular occasions…”However，he did not provide a specific name for these expressions.In the1970s，Becker（1975）&Bolinger（1976）initially proposed the term“prefabricated chunks”，which refers to the multi-word，fixed or semi-fixed formulaic"chunks"of language，between the traditional grammar and lexis.Pawley and Syder（1983）described this phenomenon of language as“a unit of clause length or longer whose grammatical form and lexical content is wholly or largely fixed”.According to them，they regard it as the key to fluent and idiomatic control of a language.In consideration of the nature of prefabricated chunks，Wray（2002）gave a specific definition，that is，“a sequence，continuous or discontinuous of words or other meaning elements，which is，or appears to be，prefabricated：that is，stored or retrieved whole from memory at the time of use，rather than being subject to generation or analysis by the language grammar.”The key notion in the above definition is the following words"stored or retrieved whole from memory at the time of use，rather than being subject to generation or analysis by the language grammar."Apparently，Wray"s definition is moreoriented towards explanation of the formation of the certain language sequences and it resorts to psycholinguistics to prove that prefabricated chunks offer processing benefits to speakers and hearers by providing a short cut to production and comprehension.3.The classifications of prefabricated chunksBecause of different definitions given by different scholars from various focuses，the generally-accepted classifications of prefabricated chunks are still far from perfection.Becker（1975）classified prefabricated chunks into the following six categories：（1）polywords which are short phrases，like oldest profession，for good;（2）phrasal constraints，for instance By sheer coincidence;（3）meta-messages which are phrases employed to replace the whole passage，like For that matter…，….that is all；（4）sentence builders，like I think that…（5）situational utterances which refer to pragmatic phrases used in certain intercommunicated circumstances，such as How can I ever pay you?（6）verbatim texts which are selected and stored whole from verbatim record，like Better later than never.Although the classification given by Becker（1975）is not specific and do not clearly distinguish the two differences between function andstructure，it is no denying that the classification by Becker（1975）provides a valuable framework for further academic research in this field.Howarth（1998）gives a much more specific classification from functional perspective.He classified prefabricated chunks into the following four categories：（1）functional expressions;（2）composite units;（3）lexical collocations;（4）grammatical collocations.Howarth（1998）fully takes the variability of formulaic language into consideration and regards prefabricated chunks as a continuum from fixity to innovation，which makes important breakthroughs from the previousresearches.But he does not fully distinguish the differences between structure and function.Among all of the classifications，this kind of classifications given by James R.Nattinger&Jeanette S.Decarrico（1992）seems to be more accepted.Prefabricated chunks are categorized into four formal types by Nattinger& Decarrico（1992）from pragmatic perspective：（1）.polywords which are short phrases functioning like individual lexical items and allow no variability，for example，by the way;（2）.institutionalized expressions which are proverbs，aphorisms，formulas for social interactions，all of which a speaker has found efficient to store as units，like How do you do?（3）.phrasal constraints which are short-to-medium length phrases and allow variation of lexical and phrasal categories，like as well as…;（4）sentence builders which are formulaic expressions that provide the framework for a whole sentence，for instance，in my opinion…，it seems that….4.The related research on prefabricated chunks4.1The related research abroadThe realization of the dualism of language gave prominence to the importance of prefabricated chunks in second language acquisition.In the late 1980s，Widdowson（1989）advocates the learning of prefabricated chunks is more important than learning grammar.To great extent，language learning is basically prefabricated chunks learning，while grammar is not generative but plays the function of corresponding.In the following decades，many scholars（Howarth，1998;Lewis，1993; Pawley&Syder，1993;Weinert，1995;Wray，2000）have done theoretical research and pinpointed the lack of prefabricated chunks in L2learners and call for attaching importance to prefabricated chunks learning.4.2The related research in chinaThe history of research on prefabricated chunks in China is not long，and the research in this field mainly focuses on the illustration of theimportance and function of prefabricated chunks and encourages second language teachers to adopt the method of teaching in terms of prefabricated chunks.4.2.1Theoretical ResearchPu-Jianzhong&Wei-Naixing（2000）emphasized“learning English with words as the starting point and the use of words as the focus of attention”and LianJie（2001）acknowledged“English lexical phrases play an important role in the learning of English as a second language.”The above two studies stress the importance of prefabricated chunks in the learning of second language acquisition.Pu-Jianzhong（2003）advocated“the emphasis of vocabulary instruction should be put on prefabricated chunks”and other researchers（Ding-Yanren& QiYan，2001，HuangQiang，2002）also did the research on the acquisition of prefabricated chunks in the process of second language acquisition.4.2.2Empirical ResearchEmpirical research in China is relatively limited，and in the following parts，a typical empirical example is selected to show the relation between prefabricated chunks and the quality of EFL learners"oral output.ExampleOral English empirical study by Wen-Qiufang（2006）The general description of this researchWen-Qiufang（2006）did the study on speaking vocabulary development.The study analyzed56English majors"spoken English data from a longitudinal perspective in an attempt to reveal patterns of change in speaking English vocabulary breath，word variation and fluency.Their spoken English data was collected four time in the year of2001，2002，2003and2004，and then their changes were calculated on terms of three periods Year1-Year2，Year2-Year 3，Year3-Year4.The56subjects in each period could display eight different patterns，each of which include three indexes which either progress or regress.According to the total number of progress index in three consecutive periods，the subjects were classified into different groups.The results and discussionThis research yielded that the English majors invested do show some patterned behaviors in their speaking vocabulary development：（1）the students who have poor master of English when they enter university made rapid progress while the progress of those who do well in English before is much slower.（2）The better their English is，the less benefit they gain in the course of teaching procedures.The result reflects a prevalent problem existing in college instructionfor English Majors，that is，the students who have good master of English when they enter university are ignored by college teachers in the course of teachers"instruction，but it should not blame these college teachers，because the number of students in one class are large and teachers cannot payattention to all the students which are at different levels in their English proficiency，and in addition，those at lower levels are in bad need of teachers"help.ments on previous studies on prefabricated chunksAfter taking a close look at the previous studies on prefabricated chunks presented above，it requires little effort to notice some limitations，which justify further research on such an issue.Firstly，all the studies had not given a clear definition to the concept of prefabricated chunks.The absence of a clear definition would make it difficult to identify what negative factors can be counted as prefabricated chunks while others cannot.An extreme instance may be that different researchers might have quite different ideas in mind when talking about prefabricated chunks and this disadvantage may make the research findings difficult to generalize.As for Wray"s tentative definition（2002）his elaboration might need modifications to make the concept of prefabricated chunks more accommodative and conclusive.Secondly，because of different definitions given by different scholars，the classifications of prefabricated chunks are different，so the results of these scholars are difficult to popularize.Thirdly，the research in this field by Chinese scholars is limited and most of their studies are theoretical not empirical.Therefore，more studies，especially empirical studies are needed so that the research findings can be easy to generalize in China.Last but not least，Chinese scholars advocate to the application of prefabricated chunks to English writing course.To an extent，the research of speaking ability is ignored，maybe the key reason is that oral English research is hard to carry out and the research period needed is a bit long，but it is believed that the findings of prefabricated chunks used in oral English course will be more valuable both to the teachers and the students.オReferences：［1］Becker，J.1975.The Phrasal Lexicon.In R.Shank& B.L.Nash-Webber （Eds.）Theoretical Issues in Natural Language Processing.Cambridge，MA：Bolt Berank and Newman.［2］Bolinger，D.1976.Aspects of Language12nd edition.New York：Harcourt Brace Jovanovich.［3］Ellis，R.1985.Understanding Second Language Acquisition.Oxford：Pergamon Institute of English.［4］Howarth，P.1998.Phraseology and Second Language Proficiency.Applied Linguistics19.24-44.［5］Lewis，M.1993.The Lexical Approach：the State of ELT and a Way forward.Hove：Language teaching publications.［6］Lyons，J.1968.Introduction to Theoretical Linguistics.Cambridge：Cambridge University Press.［7］Nattinger，J.R.&J.S.Decarrico.1992.Leical Phrases and Language Teaching.Oxford：Oxford University Press.［8］Peters，Ann nguage-Learning Strategies：Does the whole equal the sum of the parts?Language53，560-73.［9］Pawley，A.&Syder，F.H.1993.Two Puzzles for Linguistic Theory：Native-like Seletion and Native-like Influence.In J.Richards&R.Schmit （Eds.），Language and Communication.London：Longman.［10］Weinert，R.1995.The role of Formulaic language in Second Language Acquisition a Review.Applied Linguistics16：180-205.［11］Wong Fillmore.1976.The Second Time Around：Cognitive and Social Strategies in Second Language Acquisition.Stanford UniversityPh.D.dissertation.［12］Wray，A.2000.Formulaic Sequences in Second Language Teaching Principles and Practice.Applied Linguistics21：463-89.［13］Wray.A.2002.Formulaic Language and the Lexicon.Cambridge：Cambridge University Press.［14］Yorio，C.1980.Conventionalized Forms and the Development of Communicative Competence，TESOL Quarterly，XIV（4），433-442［31］.［15］黄强.2002.高年级英语学生词汇搭配习得的实证性研究.《解放军外国语学院学报》（4）：73-76.［16］廉洁.2001.词汇短语对第二语言习得的作用.《外语界》（4）：29-34.［17］濮建忠&卫乃兴.2000.词汇和语法.《解放军外国语学院学报》（2）：1-4.［18］濮建忠.2003.英语词汇教学中的类联接、搭配及词块.《外语教学与研究》（6）：439-445.［19］戚焱.2005.预制语块与大学英语写作.《山东外语教学》（5）：64-66.［20］文秋芳.2006.英语专业学生口语词汇进步模式研究.《外语电化教学》（8）：3-8.。
探讨改良式肠造瘘术在先天性中高位肛门闭锁中的可行性
24Clinical Research, May. 2020, Vol. 28, No. 05基金项目：东莞市社会科技发展一般项目（2018507150071531）。
作者简介:王坤（1986-），男，汉族，湖南娄底人，主治医师，硕士研究生。
研究方向：小儿外科。
*通讯作者：伍岗泉，mmwgq71@。
综上所述：宫腔镜应用于宫腔因素所致不孕症患者疾病诊治中，可有效对影响妊娠的宫腔因素进行诊治，帮助患者达到妊娠目的，值得临床信赖。
参考文献[1]门娴.宫腔镜治疗宫腔因素所致不孕不育患者的生殖预后分析[J].中国卫生标准管理,2016,7(3):28-29.[2]常琼.宫腔镜在宫腔因素不孕不育症诊治中的应用[J].航空航天医学杂志,2017,28(5):572-573.[3]程巧玲.宫腔镜治疗宫腔因素所致不孕不育患者生殖预后的分析[J].中国医药指南,2016,14(23):72-73.[4]王冉,孙勃,谢红旭,等.宫腔镜治疗宫腔疾病所致女性不孕患者临床研究[J].中国性科学,2017,26(6):116-119.[5]吴惠洪.宫腔镜治疗宫腔因素所致不孕不育患者的生殖预后效果探究[J].现代诊断与治疗,2017,28(1):40-41.·论著·探讨改良式肠造瘘术在先天性中高位肛门闭锁中的可行性王坤，蔡晶，卢应酬，李小卫，翟国敏，伍岗泉*(广东省东莞市妇幼保健院 小儿外科，广东 东莞 523000)摘要：目的 探讨改良式肠造瘘术在先天性中高位肛门闭锁患儿中的临床应用及其可行性。
方法 选取2016年1月－ 2019年10月在广东省东莞市妇幼保健院接受治疗的11例先天性中高位肛门闭锁的患儿，其中男8例，女3例。
所有患儿经查体及辅助检查并根据Krinkenbeck 分类确诊为中高位肛门闭锁，一期手术均行本院改良式肠造瘘术，术后监测指标包括术后肠功能恢复、营养以及是否出现肠造瘘并发症(造瘘口回缩、造瘘口突出、伤口感染以及切口疝)等情况。
文献检索的基本原理英文版
See Chapter 1, 3one of the basic principles of a literature search. The basic principles of literature search through the literature search is actually a search tool to find the information they need 。
The principle Simply put ， the question is to identify and retrieve those stored in a retrieval system identification literature to compare two identification documents contain the same or need to retrieve the identification ， put the logo features a literature retrieval system from in output ， the literature is the literature search initially hit. This includes storage and retrieval of documents ， as shown 。
Comparison and selectionStored procedure ：the retrieval process:Document Information Search topicAnalysisAnalysisDocument Information featureInformation retrieval questionsBibliographic indexing ExpressionFormFormSearch language and name authorityCharacterizationExpressInfor matioCharacteriz ationExpressInformation collectionIdentification document information （access points）Search Question ID （search terms）EnterSearchRetrieval system (identified more)OutputSearch Results（Perfectly matched, related, unrelated）2．Information storage and retrieval 1)information storageretrieval booksAbstract number: 020001Title: the dye in production of the microcomputer controlAuthor: zhang Ming; Chien—ming wang；LiuJianYeInstitution: Beijing institute of chemical （Beijing 100001）Literature sources （source) ：chemical technology, 2002。
英汉语言对比抽象与具体
• Conclusion:
• Abstract style is used excessively in English. Some stylists recommend mixed diction
Concrete Chinese
The concern with abstraction characteristic of ancient Greek philosophy has no counterpart in Chinese philosophy. Chinese philosophers quite explicitly favored the most concrete sense impressions in understanding the world. In fact, the Chinese language itself is remarkably concrete.
• III Many abstract nouns which are derived from adjectives and verbs can produce miniaturization of complex structures. • Jesperson said "this is handy expressions for complex thoughts".
• 4）不用脑子，愚笨，无知；不注意，粗心大意； 无需动脑筋 • mindlessness • 5）保护消费者利益运动；（主张以消费刺激经济 的）消费主义 • consumerism • 6）新闻节目主持人的语言风格或用语 • anchormanese
•
An excessive reliance on the noun at the expense of the verb will, in the end, detach the
1. Abstract An Experimental Adaptive Expert System
An Experimental Adaptive Expert SystemXiaoshan PanCollaborative Agent Design (CAD) Research CenterCal Poly, San Luis Obispo, CA, USA1. AbstractThis paper explores an approach to building an adaptive expert system in an environment of human-computer collaboration. Components of an adaptive system are identified, with an emphasis on the mechanisms that enable adaptive behavior to occur. Knowledge representation in a rule-based, object-orientated expert system is described through the establishment of appropriate relationships utilizing heuristic rules, objects, and agents. The experimental expert system displays low level learning capabilities that show sufficient promise to warrant further research.This work was undertaken as a Master Degree Thesis in the Architecture Department of the College of Architecture and Environmental Design at California Polytechnic State University (Cal Poly), San Luis Obispo, California.2. Keywordsexpert system; adaptation; learning; knowledge representation; rule-based system; object-oriented design; data; meaning; information; objects; agents; human-computer collaboration. 3. Introduction“An expert system is a system that employs human knowledge captured in a computer to solve problems that ordinarily require human expertise (Turban, 1992, p. 74).” Well-designed systems emulate the reasoning processes used by experts to solve problems, and are popularly used in medicine, business management, design, and searching for natural resources.“Even though expert systems aim to mimic human experts, they lack an extremely important capability of human intelligence: the ability to learn from experience (Turban, 1992, p. 666).”First of all, it takes a significant amount of time to build an expert system with many hours of testing and debugging. If a human expert comes to an incorrect conclusion, he may be able to learn from the mistake and avoid making the same or similar mistakes in the future. Once an expert system is found to have an error, the only way to correct that error is to reprogram the expert system. In other words, most current expert systems are lacking an adaptive capability.Computer based adaptive capabilities are essential in situations where environments change, in situations where standards of expertise are changing, and in situations where there are no historical data and learning occurs as a task that has been performed.Webster (1991) defines ‘adapt’ as a capability “to adjust (oneself) to new or changed circumstances (p. 15)”. In nature, adaptation is sometimes referred to as ‘evolution’. In the context of a system it may be referred to as a ‘self-organization capability’, and, in the case of human beings, as a ‘learning capability’. Therefore, since the intent of expert systems is to emulate human experts, this paper refers to an adaptive expert system as a learning system or, a learner.A goal of the research described in this paper is to explore strategies that enable an expert system to adapt to, or learn from, interactions with users. It is assumed that a relatively primitive computer-based adaptive capability can be of significant value in a problem-solving environment in which a computer is used as a collaborative decision-support tool.Because of its capability to support rule-based programming and object-oriented design, the C Language Integrated Production System (CLIPS) Version 6.10 was chosen as an expert system tool for this project (NASA, 1998).4. Rule-Based Programming and Object-Oriented DesignRule-based programming is commonly utilized to develop expert systems. Rules are used to represent heuristics, which specify a set of actions to be performed for a given situation. According to Giarratano and Riley (1998), rule-based expert systems are popular for a number of reasons:•Modular nature. This makes it easy to encapsulate knowledge and expand the expert system by incremental development.•Explanation facilities. By keeping track of which rules have fired, an explanation facility can present the chain of reasoning that led to a certain conclusion.•Similarity to the human cognitive process. Rules appear to be a natural way of modeling how humans solve problems. (p. 28)Object-Oriented design is “a technique for developing a program in which the solution is expressed in terms of objects – self-contained entities composed of data and operations on that data” (Dale et al. 1996, p. 162). Taylor (1998) proposes that object-oriented design is an ideal approach for building adaptive systems because “objects are naturally adaptive elements. If allowed to interact freely, managing their own actions, they can be excellent components for building up adaptive systems “(p. 147).5. A Learning EnvironmentThe word ‘learning’ is mainly reserved for human beings. Researchers have long wondered whether computers could also learn. In order to answer this question, a definition of learning isnecessary. According to Lacey (1998), learning is “Any relatively permanent change in behavior brought about through experience – that is, through interaction with the environment (p. 25)."It could be assumed that learning may involve four factors: the learner; the environment; their interaction; and, state. A learner could be defined as a relatively independent system, exhibiting a learning capability and adapting to its environment. In other words, a learner is a system with the capability to change itself as a result of interactions with its environment. The constantly changing environment provides a basic force that drives a leaner to learn.A state is a collection of characteristics that can be used to define the status of a learner and its environment at a certain time. An environment is partially comprised of the external circumstances of a learner, and influences the way in which a learner behaves. In other words, a learner exists in an environment, which changes over time. The internal impact of this external environment impels the learner, which results in adaptive action on the part of the learner.An approach to learning, therefore, is through the interaction between the learner and its environment. The interaction operates in terms of three basic elements: percepts; actions; and, goals. Shen (1994) defines these elements as follows:“An action is a physical change that occurs inside the learner, such as a muscle contraction inside a human body or an electrical signal sent to some switch in a robot.A percept is a representation inside the learner about the state information of theenvironment.A goal is defined as a set of percepts that the learner wishes to receive from theenvironment.” (p. 8)Shen (1994) also explains the learning process as:“With actions and percepts as building blocks, the learner is to construct a model of the environment so that it can predict the consequences of its actions and direct its actions towards the goal.” (p. 9)Accordingly, a learning process is a process in which a learner builds models of its environment. In addition to the physical world that is external to the learner, it is suggested that there also exists an internal model world within the learner. The learner builds models and stores them in this model world. These models represent the learner’s understanding and knowledge of the external physical world. Minsky (1985) states that, “We all make models of ourselves and use them to predict which sorts of things we’ll later be disposed to do (p. 303)."According to Shen’s definition of learning, a system should not be called a learning system if it merely contains the capability to repeat exactly what it has been designed to do. A learning system must have the capability to gain knowledge and adapt its behavior accordingly. In terms of the two worlds concept, a process which gains knowledge is equivalent to a process that revises old models and builds new models based on interactions between the two worlds. In this regard, memorization and creation are two possible methods of knowledge acquisition.When knowledge is available, and a learner possesses and uses a capability to obtain and store this knowledge from its external environment, this capability could be defined as memorization. An example is a child studying arithmetic from a textbook.When an old model has been evaluated as inappropriate to any given circumstance, and no existing, applicable knowledge is available, creation becomes an important approach to the production of new knowledge. Creation may be considered a higher level of learning. Memorization and creation represent an initial phase of a learning process. The construction of a model, according to Shen (1994), is “essentially a loop process of generate-and-test: one starts with a model, tests the model by observing its performance, and generates a new model if the current one is not good enough (p. 25)". This might suggest another significant factor in a learning system: evaluation. Evaluation generates feedback after an action has been taken. This feedback then goes back to the percept process, causing the updating of the model. If we regard a system that cannot learn as a dead system, then this evaluation process is an essential difference between a learning system and a dead system.In this generate-and-test loop, the evaluation adjusts the actions as well as the goals of a learner, and sends stimuli back to the loop for model revision. From the point of view of human beings, a process that discerns between right and wrong, or appropriate and inappropriate, must contain a set of criteria. When a change in the physical world causes a change in the criteria system, a corresponding change in the learning system results. This process would not occur in a dead system, because it is not represented by a loop, but rather by a unidirectional flow, with no provision for feedback. Memorization and creation do not exist in a dead system because the process of evaluating and handling feedback, which affects actions, does not exist.6. Knowledge Representation6.1 From Data, Meaning, Information to KnowledgeComputer systems have displayed significant increases in sophistication and capability while maintaining basic data storage and manipulation principles. Data in a computer system, based on a particular computer language, are letters, numbers, strings or special characters. A single piece of data consists of a combination of electrical pulses. It has no meaning to the computer by itself. Minsky (1985) states, “the secret of what anything means to us depends on how we’ve connected it to all the other things we know… a thing with just one meaning has scarcely any meaning at all (p. 64).” In other words, the more associations a thing has with other things, the more it will mean to us.The meaning of a single piece of data derives from its association with other data. For example, A Chinese character may have little meaning to English speakers if they do not know anything about the Chinese language. For them to gain understanding, an explanation of this Chinese character in the English language is necessary. During this process, the English speakersestablish associations between this character and what they already know, and then meaning appears.Approaches to building associations between data in a rule-based, object-oriented expert system include writing rules and object methods that manipulate the behaviors of data. Information is data with behavioral characteristics and relationships. Data are basic building blocks of information, and relationships among data endow meaning. Functionally, a piece of information must describe a state, such as, ‘mail is sent’ and ‘it is raining‘.Information may be defined as data linked by relationships, which can describe the state of an event, a condition, an item, or an object.“When human beings or computer-based agents draw conclusions (i.e., inferences) from information then these conclusions are knowledge” (Pohl, .). Knowledge exists when humans attempt to solve problems or make decisions based on the state of a condition, and information provides a description of the state. In a rule-based computer system, the process of taking certain actions based on certain conditions can be represented as rules. Thus, information and rules can define knowledge.“Rules appear to be a natural way of modeling how humans solve problems (Giarratano and Riley, 1998, p. 28).” When humans solve problems and make decisions, rules represent heuristics, or “rules of thumb”, which specify a set of actions to be performed for a given condition. Heuristic rules provide shortcuts when describing relationships and behaviors. Heuristic rules mostly come from experience. Intermediate steps are skipped because those steps might be functionally unnecessary or unlikely to lead to a quick solution of the problem. This is why an expert usually has been perceived as a person who is capable of "solving problems without thinking".Heuristic reasoning does not refer to the working of the internals of the system, but rather associates readily definable external observations with a plausible conclusion. Instead of heuristic rules, a deeper causal model also might come to the same conclusions, but would in principle need to examine many other things, and some of which might not be easy to answer without additional measuring facilities. In a rule-based expert system, rules may represent associations among data and reasoning processes used to solve problems and make decisions.6.2 Objects and Agents“An object is a software package that contains a collection of related procedures and data (Taylor, 1998, p. 7).” Procedures may be referred to as methods, which are relationships and behaviors among data. Objects are defined as encapsulations of properties (facts) and behavior (relationships among facts) in CLIPS Version 6.10 (NASA, 1998). Objects represent information. A well-defined object describes its states with the data it holds, and manipulates the data through its methods. An object-oriented system processes information, rather than data.Everything an object ‘knows’ is captured in its variables (data), everything it can do is expressed in its methods. This notion not only keeps simple things simple, but also makes complex things simple as well. No matter how many objects or what types of objects exist inside a system, relationships among those objects are clearly described by their methods. The more objects the system contains, the more complex it can become. When a change occurs in an object, other objects will react correspondingly to adapt to the change; thus the system can reorganize itself automatically.Objects are ideal building blocks to build adaptive systems. Since methods are encapsulated with data into objects in an object-oriented computer system, when a change is necessary, even if it is possible to change only a single or a few objects then the whole system will adapt to this change automatically through the reactions of other objects. However, in a conventional system (i.e., non-object-based), a change will require significant restructuring, anything less will result in a broken system.Information in an object-based computer system is not separated into data and procedure, but rather stored as objects. Objects can be exchanged with, or shared by, other systems, enabling adaptive behavior to occur not only inside a system but also among different systems.During the related processes of problem-solving and decision-making, human beings may be capable of drawing conclusions, finding solutions and taking actions based on available information. A computer-based system that behaves in such a fashion may be referred to as an agent. "Agents are nothing more or less than objects with rules and legs (Taylor, 1998, p. 131)." In a rule-based, object-oriented expert system (like CLIPS), an agent is comprised of one or more rules that are capable of solving problems or making decisions based on information derived from objects. Objects are useful for solving problems and making decisions, but become more useful when they are converted into agents.Taylor (1998) explains: “It is an unfortunate fact that most objects are rather stupid. They contain methods for executing procedures, and they have variables to hold the inputs and outputs of those procedures. But they lack a good mechanism for capturing the rules that determine when and how these procedures should be carried out. If you ask them to do something, they do it. If you don't, they just sit there” (p. 125).Agents act at the knowledge level. Data within an object describe ‘what’ the object is, and object methods indicate ‘how’ it will react to changes. A rule, which acts as an agent, will provide some control of ‘when’ and ‘whether’ the object carries out its methods.6.3 Notions from the Theory of Complex Adaptive SystemAll scientific studies are in the business of trying to make sense of the world, and research of Complex Adaptive System (CAS) is one of these. A driving force behind CAS research is a desire to understand how complex order arises out of the interaction of relatively simplecomponents, such as: “How did life emerge out of the interaction of inert molecules? How do termites cooperate to build arches and other architectural structures? How do the phenomena of thought and consciousness arise out of the interactions of neurons in the brain?” (Taylor, 1998, p. 137)Wholes are made of parts but are more than the sum of their parts. An example of a complex adaptive system is the collective behavior of ants. An individual ant may exhibit relatively simple behavior. When a significant number of ants collaborate, interactions among them reach a level of complexity, and then a high-level order from which adaptive behavior arises. This high-level order enables all ants to act as a whole. The whole is likely to achieve a level of intelligence unattainable by any individual ant.Complex order may arise through the interaction of simple components. Objects are natural building blocks of adaptive systems. The research described in this paper is based on the premise that a computer-learning capability can come into existence through the interactions of simple elements (e.g., objects).7. Human-Computer CollaborationWhile engaged in the process of problem-solving and decision-making, human beings typically draw upon a broad range of personal experience and often rely upon intuition. Computers, on the other hand, have a narrow area of expertise, greater computational power, and lack a good mechanism for knowledge acquisition through experience.Human-computer collaboration proposes an approach in which computers and humans co-operate to solve problems, especially to solve those problems that neither can effectively solve alone.For example, an expert system helps non-expert humans to solve problems and make decisions based on internal expertise. The system might not work appropriately if the problem changes, unless human users provide more knowledge. The system may thus be said to learn through its interactions with humans.8. Building an Adaptive Expert SystemAn expert system could be viewed as one heuristic rule, or if-then statement, since all rules in the system work together to define a specific condition, which is achieved by asking a user relevant questions. Thereafter, the system reacts with one or more actions. It is postulated that an expert system becomes adaptive during an interaction with a human user if this system proves to be capable of the formulation of new relevant questions and the adjustment of action(s).8.1 Knowledge-Node-NetworkThe concept of a knowledge-node-network is proposed as an approach to knowledge representation in building an adaptive rule-based, object-oriented expert system. In a knowledge-node-network, all nodes are represented as objects, and adaptivity of the system is achieved through node modification and creation. Two types of nodes exist in a knowledge-node-network: question nodes (i.e., representation of relevant questions); and, action nodes (i.e., representation of corresponding actions).A question node may contain one or more input-connections, each weighted, whose values change based on a successful search or a failed search. Each input-connection corresponds to two output-connections, each of which connects to another question node or action node. A question node carries a relevant question and a corresponding answer-key. During a reasoning process, if a question node is activated by a message, the question will be evaluated, and the return value will lead to the next activation.An action node may contain one or more input-connections, each weighted, whose values change based on whether user feedback is positive or negative. An action node carries one or more actions, and may be activated by messages sent from question nodes.Also, such a knowledge-node-network contains an initial body of knowledge (i.e., a group of question nodes and action nodes with appropriate connections). Upon interaction with human users, this initial body of knowledge may prove inadequate within the context of a changing problem. The system adapts to these changes through the modification of existing knowledge nodes and the creation of new knowledge nodes.In a knowledge-node-network, each node is associated with a value represented by either a relevant question or an action. Each node also contains connections to other nodes. The creation of new nodes and the modification of either the value or the connections of the node are defined as constituting a form of system adaptation in response to a change.8.2 Concept of Mind ObjectThe concept of "Mind" object is implemented as an agent-control strategy. Similar to human behavior, no matter how many things we want to do, we can choose to do only one at a particular time. "One part of me wants this, another part wants that. I must get better control of myself (Minsky, 1986, p. 40)".In the experimental expert system that was developed as part of the research, a "Mind" object acts as an "agent manager" that decides which agent should be activated at any particular time. The "Mind" object is designed with six different "states"; namely “inactive”, “querying”,“feedback”, “modifying”, “creating”, and “reporting”. Each state represents a condition that will trigger a particular agent to be active. The concept of a “Mind” object proposes a useful approach to solving conflicts, especially when both randomness and probability are unlikely good decision-making approaches, because a “Mind” object provides uniqueness. Since the state of the “Mind” object is changed dynamically by the activation of agents and object methods,each agent and object evolves as a part of the decision-maker. In other words, the control mechanism is not hierarchical but parallel.In the experimental system, a state of the "Mind" object involves one agent only. However,according to Minsky (1993), a state of the human mind involves innumerable agents and subagents, leading to a much higher degree of complexity: “Let's oversimplify matters for the moment and imagine that the mind is composed of many "divisions," each involved with a different activity, like vision, locomotion, language, and so forth. This pattern repeats on smaller scales, so that even the thought of the simplest ordinary object is made up of smaller thoughts in smaller agencies…a mind can have exactly one total state at any moment, but it can be in many partial states at the same time” (p. 85).8.3 System ArchitectureIn terms of inference process, an adaptive expert system describes a generate-and-test loop that endows a system with a leaning capability (Figure 1), while a conventional expert system describes a unidirectional flow with no adaptive behavior. From a system structure perspective,an adaptive expert system differs from a conventional expert system as follows:A). Unlike a static knowledge base in a conventional expert system, an adaptive expert systemcontains a dynamic knowledge base. Knowledge is represented by a knowledge network (i.e.,Figure 1: System Architectureobjects and their interactions) that can be dynamically modified in real-time based on interactions with the human user.B). In addition to containing the capabilities of a conventional inference engine, an adaptive expert system is capable of real-time adaptation to feedback and restructuring of the knowledge network.The architecture of such an adaptive expert system consists of three major components: an inference engine; a knowledge network; and, a node-modification agent engine. The inference engine infers through condition-satisfaction action selection. In the rule-based system, it searches for the rules satisfied by facts or objects, and executes the rule with the highest priority. The knowledge base is composed of knowledge nodes and their connections. The node-modification agent engine consists of a node-maintainer, a node-builder and a node-merger. These agents analyze feedback and reconstruct the knowledge base accordingly.The goal of the system is the development of corresponding answers to satisfy the needs of clients based on client provided information. The mechanism provided by this system demonstrates a primitive adaptive capability of a computer-based expert system (Figure 1).9. Typical ScenarioThe following sequences exemplify some adaptive behavior capabilities of the experimental system, simulated by the interactions of the user with the system.System :Hello, this is Shawn's-Kitchen-Design-Adviser!May I have your name, please?User :Lee, Tony.(Identifying the user…)System :Tony, You are my new client, welcome!For providing the best service, I need to ask you some questions.If you are ready, answer 'y' to continue...User :y(System asks the user relevant questions…)System :How much do you entertain at home?1. Several times per week2. Once a week3. Several a month4. Once a month5. Hardly everUser :1.System:…User:…System:How important is energy conservation in your kitchen?1.Very important2.Desirable3.Average4.Unimportant5.Don't knowUser:1System:Well, Tony, one moment please...(Searching for design recommendations based on the user’s responses…)System:Tony, the followings are my recommendations for you:...5). -- Window should face south for collecting maximum natural lighting.6). -- Adopting passive solar panel as an energy saving approach.7). -- Using skylights for collecting natural lighting....Are you satisfied with them? y/nUser:n (negative feedback)(System identifies the problem since it receives a negative feedback…)System:That's fine, Tony, let's work this problem out together...May I know which one seems not appropriate to you?Choose the number from above...User:6System:What you've chosen is...-------------------------------------------------------------------------------6). -- Adopting passive solar panel as an energy saving approach.-------------------------------------------------------------------------------Why is it inappropriate in your case?1. It doesn't make any sense at all.2. It basically is fine; you just want to refine it.3. You have a physical constraint against itUser:3(All three options listed above cause modifications in the knowledge-network. Option one and two trigger agents to update the value and connection weight of knowledge nodes, and option three triggers agents to build a new knowledge node.)System:Would you please explain to me what is the constraint?User:because my wife will not like it.System:What do you mean 'it' exactly?User:the idea of passive solar panel.System:So, it is inappropriate in your case because...Your wife will not like the idea of passive solar panel. Am I right?User:y。
abstract例子
Study the following information and then write an abstract of no fewer than 150 words.Title: Examination of Abstract Writing StylesSample: 2,460 university student abstracts--- 40 universities---physical sciences Methods used: Analysis of variance + least squares fit of percent errors vs. program level.Conclusions from style table: Southern universities used more verbose (冗长的) style; northern universities, more cryptic (晦涩的)style.Correlation study: (1) Students whose parents were below the “poverty level” (58% of the sample) showed intermediate writing skills at the freshman level but improved more quickly with time ending with MS or PhD levels; (2) Students with parents above poverty level showed initial advanced writing skills and slowly improved to the professional level at the MS or PhD levels. Respective correlations for (1) and (2) are 84% and 88%.Recommendation s: (1) State educational systems---prepare students at the high school level in basic writing skills; (2) Universities---technical writing course mandatory for science/engineering university students at the junior (third-year) level.Examination of Abstract Writing StylesAbstractA large sampling of abstracts was obtained from across the U.S. This paper presents the results of the analysis of the abstracts. Several statistical methods were used in the study. A table of styles vs. locality in the in the US is presented. Several interesting conclusions of the correlation study are discussed. Finally, recommendations are made on how to improve abstract preparation.Examination of Abstract Writing StylesAbstract(In view of the U.S university student abstracts, there is an urgent need to shed light on their writing styles.) This paper aims to examine the abstract writing styles written by university students majoring in physical sciences. A large sampling of abstracts, i.e. 2,460 university student abstracts, was obtained from across the United States, among which 40 university students majoring in physical sciences were selected. Different statistical methods were carried out: analysis of variance and least squares fit of percent errors as against program level approach. As a result, the findings from the table style led to the conclusion that southern universities tended to use more verbose style while northern universities tended to adopt more cryptic style. Moreover, interesting conclusions of the correlation study were drawn:Students whose parents were below the “poverty level”showed intermediate writing skills at the freshman level butimproved more quickly with time ending with MS or PhD levels; on the other hand, students with parents above poverty level showed initial advanced writing skills and slowly improved to the professional level at the MS or PhD levels. Also recommendations are made, such as preparing students at the high school level in basic writing skills under state educational systems and setting up technical writing course mandatory for science or engineering university students at the junior level.。
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An Overview on Portable Human Machine Interfaces forTeleoperation Control of Robotic SwarmsPaolo Villella, Carlo Alberto Avizzano, Massimo BergamascoPERCRO- Scuola Superiore Sant'AnnaPzza Martiri della Libertà56127 Pisa[carlo,villella,bergamasco] @ sssup . itABSTRACTThe paper contains an overview and an analysis of the interaction problems between humans and robots applied to the exploration of ground areas. An analysis of factors affecting the efficiency of the interaction is presented with an overview of the design principles of an Operator Control Unit (OCU). Finally, future pathways are suggested for the research on advanced human-machine interfaces.s1.0 INTRODUCTIONThe military is currently using robotic systems for applications such as searching dangerous areas and for explosive ordnance disposal. The ability of such robotic systems to find the targets can be strongly improved augmenting the number of robotic units involved in the exploration, each unit bearing a different sensorial payload and thus contributing in a complementary way to the assessment of the situation. To date, one or two operators are needed to control a single robot, due to the fact that the teleoperation is completely manual. When several robots are involved in the exploration, the number of operators controlling these robots becomes unacceptable, so semi-autonomous behaviours of robots have to be assumed. This way, we can reduce the number of operators controlling the robotic team, possibly to one single operator. This situation is the optimum because robots are wondering around for the larger part of time without sending useful information, leaving the operators with nothing to do. How can a single operator control several robots? Due to the limitations in “attentive capability” of the operator, information from robotic units cannot be considered simultaneously, so the OCU should present the right information at the right moment, reducing the attention payload exerted by the operator. Moreover, the operator should not be limited in his movements by the OCU, that should be light, portable and rapidly removed in order to get a rapid assessment of what happens near the operator.To study the system composed by robots and human, we need to consider the capabilities and limitations of robotic autonomous behaviours and develop new procedures and workflows accordingly. The performance of the overall system is strongly affected by the ability of the human operator which evolves on the field. As a matter of fact, completely autonomous systems currently do not exist in domains requiring more than simple ripetitive behaviours, so it is necessary for humans to interact with the robots to accomplish certain tasks. In order to understand interaction, some fundamental questions exist such as:• How many robots can any one individual control?• What other tasks may a human be able to do and still control a robot?• How does situation awareness affect the number of robots that one operator can control and the performance of another non-robotic task?This set of questions defines the problem of determining the so called “Human-robot interaction (HRI) efficiency”. In this paper, we discuss a number of factors that affects the HRI efficiency and present anPAPER TITLEoverview on the existing technologies available. Finally, a discussion on these topics is aimed at suggesting possible pathways for future developments.2.0 HUMAN ROBOT INTERACTION FOR MULTIPLE VEHICLESIn a multi robots control scenario, mobile platforms are likely to be spatially dispersed providing to the users additional difficulties in the comprehension of the scenario, the planning of the activities and the execution of coordinated tasks. As a matter of fact, current visualization systems for mobile robots are mostly designed around multiple view of a single context (MVC) that exploits the classic paradigm of one information source and for one user. However, when a typical multi robot scenario is considered the information is provided to the user from multiple sources.2.1 ScenariosAs introduced by Yanco and Drury [1], the kind of human robot interaction changes when a scenario with multiple entities is considered, basically we can consider 8 types of different scenarios:Control Target NoteSingle user Single robot The user has complete perception and control of the robot behaviour,information sharing among users and platform is unnecessarySingle user Multiple robots One to many interaction requires that the user issue the command fordriving independently each robot. If parallel control strategies areaddressed, higher level of interaction (from direct motor control) arerequiredSingle user Robot Group Group of robots cooperates each other accordingly to inputs providedby the user. Robots Group control requires different syntaxes andsemantics to describe group strategies. In this kind of interactionaccuracy of performances should be demanded to local robot autonomyMultiple users Single Robot Multiple users, having separate OCUs, may compete in the use of a common vehicle. Coordination among the users is provided externallyand priority strategies are implemented to avoid conflictsTeam SingleRobotDifferent users are made aware of the common strategy that will beexecuted on the device. Each user may collaborate to refine the strategy Team Multiple Robot Allows a team to perform parallel independent activities and/oralternate the control on robots acting in separate environments. Usefulfor competency/skills separation and user turnoverTeam Robot Group Team-Robot group control allows teams to perform group strategywithout the need of demanding accuracy to robot autonomy, each usermay alternately take the control of a mobile platform for performingspecific strategical tasksMultiple users Robot Group Each user independently acts on the robot group as he was alone, groupcontrol strategies will implement the required conflict avoidanceproceduresTable 1: Mobile HRI scenariosObviously, the number of functionalities increases with the complexity of the interaction scenario. The first scenarios, marked in boldface, are the most addressed in the scientific literature. Only few operating environments, such as the teambots or the MOCU [2, 3], allow addressing more complex scenarios.PUB REF NBR (e.g. RTO-MP-IST-999) PAPER NBR - 3PAPER TITLEBehaviouralteleoperation The control algorithm is integrated with a set of complex control loops that may automatically generate driving actions (reaching a target, obstacle avoidance,...). Robotbehaviours diminish the level of attention required to the operator but are typicallylimited in functionality due to complexity of implementation and strongly dependanton environmental conditions (such as lighting) Traded control Usually the robot operates autonomously, and the operator intervenes only in specificphases of the task, when the cognitive role in the execution is fundamental.Shared control The vehicle implements two parallel control loops, one part is completely autonomous,the other one is teleoperated by the humans. The autonomous part may detect specific events in the teleoperation loop to determine the phases of its activities Mixed initiative The vehicle is independent form the user and only interacts with the operator at level ofstrategy decision and initiative. Typically suchforms of collaborative control onlyimplements a reduced set of questions and answer the robot is able to automaticallysolveRobotcompanion Robot is independent from humans and cooperated with him to perform task in the environment. The robot is able to undertake decision autonomously while not violatingspecific orders of the humans.Table 2: Mobile Robots autonomy levelsFor our purpose, we define two types of human-robot relations [9]:• Interaction, that is a planned collaboration. For example, if an operator is required to inputinformation about a mission to the robot scout, this event would be called a human-robot interaction.• Intervention, that is an unplanned instance of collaboration. For example, the robot canautonomously wonder in the environment in search of a particular target, but in a particular mission has a problem and is unable to maneuver around an obstacle. The robot calls for help from the operator to identify the obstacle and plan a course of action. This may involve a period of teleoperation or simply requires the activation of some automatic procedure.The interaction requirements can be well defined given any particular implementation of a robotic system. However, we must probe further to determine how to predict intervention possibilities.2.3 Interface EfficiencyAccording to Crandall [9], the interface efficiency is the “measure of the effectiveness of the interface”. In ISO 92411-11, efficiency is the measure of the time needed to complete a given task. Effectiveness is the percentage of a task that the user is able to complete using the given interface. Along with user satisfaction, these measures are used in assessing the usability of a user interface. The three measures are weighted relative to the requirements of an application. If an application is time critical, then more weight is applied to efficiency measure. For applications that are life critical, more weight is given to the effectiveness measure while if an interface is addressed to the entertainment place the user satisfaction has a higher weight. The time to complete a given task can grow up if the user is not able to complete a given task and substitutes it with with a similar one. If the user cannot find a substitute and the task is never completed, the interface efficiency will drop to zero. The following are the main factors that affect HRI efficiency:• mode of autonomy: according to Crandall, we define the neglect tolerance as “the measure of theefficiency of a robot’s autonomy mode”. For example, if the robot is in direct teleoperation PAPER NBR - 4 PUB REF NBR (e.g. RTO-MP-IST-999)PAPER TITLE control, the operator cannot neglect it because as soon as he stops control, the robot stops performing, so the neglect tolerance would be zero. However, if we choose to move the robot intoa certain position to give situation awareness about the environment, although the operator ignoresit, the robot is providing utility and the neglect tolerance would be different from zero. If the robot is completely autonomous it requires no intervention and then the neglect tolerance would be infinite. At current state, the robot may not do anything by itself and requires at least a supervisory control. The neglect tolerance is a useful metric but cannot be equated to the necessity for user intervention that is strongly affected by the “world complexity”.• user interface: the intervention time will be affected by the efficiency and effectiveness of the user interface. This topic will be developed in section 3.0.• number of robotic units: When the operator is supervising and controlling several robots as needed, the operator may have time in between interventions to monitor the vehicles. If we provide interfaces to display only relevant information for situation awareness for both vehicles, as opposed to too little or too much information, the time to acquire accurate situation awareness should be reduced and the situation awareness should be maximized.2.4 Situation AwarenessIn order to gather information about the environment and control the robotic team, it is necessary that the operator have situational awareness. If the robot is continuously teleoperated, the operator is always involved and any lack of situation awareness is due to ineffective presentations in the user interface or to a lack in sensory inputs. If the operator is less involved, there will be some amount of time for him to acquire current situation awareness, leading to a delay in the control loop. The more frequent problems are:• the operator’s loss of skill to perform the task manually• the operator’s loss of the state of the robotIn our study, we are particularly interested in the loss of situational awareness which implies that an operator taking over in the case of the failure of an autonomous system will need additional time to determine the current status of the system. According to Endsley [10], we can define three levels of situation awareness:• Level 1: there is perception of the relevant status information• Level 2: there is comprehension of the status information• Level 3: there is prediction, i.e. the ability to use this comprehension to consider several future situations related with the current one.In the literature there are many experiments aimed at determining the effects of a loss of situation awareness for different levels of automation [11]. In each case the operator has to intervene. The time to complete the task is always larger than the time to do it manually, due to a consistent difference in Level 2 situation awareness.PUB REF NBR (e.g. RTO-MP-IST-999) PAPER NBR - 5PAPER TITLE2.5 Technical readiness level assessmentTo determine how all previous factors affect the HRI efficiency, we need to look more closely what characteristics of the operator, mission, robot and user interface affect the interaction time and the robot neglect time.For the sake of simplicity, we assume that the operator is only allowed to respond to requests for help from the robot. We can consider the following categories of problems for which the robot could request help:Category ofhelp requestDescriptionNEED OPERATOR OCU map display says it needs help Cannot back upMax backup attempts exceeded Other as displayed in the GUI windowMOTION The vehicle has not moved on the OCU map for more than a fixed period of timeThe vehicle loops back onto its pathThe vehicle stays in the same area (fixed dimensions) for more than a fixed period oftimeTERRAIN Robot pitch or roll is more than a critical valueTraction is slipping and the vehicle is stuckToo roughCOMMUNICATIONSCommunications with the OCU and/or with other vehicles are lostOBSTACLE Inable to overcome an obstacleNavigation confusedStopping because the sensors say soPATH The vehicle is too far from the target areaThe vehicle is pointed in the wrong direction at start of missionThe vehicle is about to cross into a restricted areaPLAN FAILURE No good plan for a whilePlanner diedMECHANICAL Electric motors too hotLow battery levelPAPER NBR - 6 PUB REF NBR (e.g. RTO-MP-IST-999)PAPER TITLE In the following, we analyse the workload of the operator in two cases:1) The operator controls a robot and has another non-robot task to work on when the robot isin autonomous mode;2) The operator controls two semiautonomous robots.2.5.1 Case One: an operator controls one robot and works on a taskThe time to monitor the status of the robot or just to respond to some sort of alert has to be detracted from the time to complete the second task. Thus, the time to switch includes:1) Time to notice the alert from the robot2) Time to pause the second task3) Time to acquire the situation awareness to determine what to do (not less than 30 sec)During this period the robot has been of no utility. In most cases, the robot remains stationary and if we are performing a time critical task this situation could be inacceptable.2.5.2 Case Two: an operator controls two robotsFor the sake of simplicity we assume that the two robots have the same performance characteristics. In the exploration of complex environments, robots encounter many problems. So the operator is often required to intervene, locating an opening and pointing in that direction. If the intervention by the operator is requested by both robots, one will remain stationary and thus of no utility. Calculations to determine how many robots one operator can manage need to take into consideration the robot neglect time, the time to acquire situation awareness for a given type of problem and environment, and the average intervention time for this type of situation. The type of mission dictates the constraints on how long robots can be out of operation.3.0 PRINCIPLES OF OCU DESIGNDesign for mobile robot OCUs is typically minimalistic since these systems should take into account the best possible trade off among the robustness and the simplicity of use. Moreover, as seen in our previous section, most of the operating systems interacts with users within simple scenarios and using basic teleoperation paradigms.The typical military application of these system requires that they should be manoeuvred by military personnel in critical conditions that do not allow any high level of attention to be paid to the control interface. In such a condition, it is clear that whichever design is performed it should reflect the following requirements:• Natural Interface Interaction, the command issued and the consequent vehicle actions have a direct and clear logical relationship that reflects everyday life experiences. The naturality of interaction is not a whole quality of the GUI system, but relates each single task (e.g. drawing a trajectory on a map, targeting objectives,...).• Quality of interaction metaphors: metaphors alters the way of perceiving events by correlating a measure to a different representation that may be more effectively showed in the OCU. Metaphors should be familiar to the user in order to achieve tasks and procedures easier and faster• Proper information highlightings (text messages, icons, animation, visual hints and menus). In PUB REF NBR (e.g. RTO-MP-IST-999) PAPER NBR - 7PAPER TITLEremote control of mobile platforms, a great part of the environment information is lost and partially replaced by alternate information, the design ofa HRI should carefully consider which visual hints have to be shown during the vehicle operation by balancing awareness and user load.• Easiness to access higher levels of interaction from teleoperation to mixed initiative (robot companion do not require OCUs) by easily delegating a varying level of autonomy to the remote vehicle. The more autonomy is delegated to the remote vehicle, the more the user is relieved from performing tedious tasks.• Abstraction from OCU spatial collocation and camera pose. Most OCUs induce error onto the operators when the camera position is too low or too high with respect the vehicle geometry. Well designed OCU should be able of generating operator views aligned with the normal motion strategies of humans.When we consider support for Multiple or group vehicles and team controllers the OCU interfaces become more complex. Some of the complexities include:• organizing and displaying single as well as group vehicle information;• monitoring individual vehicle tasks vs. groups strategies and coordinating vehicles to optimize performances;• support multithreaded control and multiple OCU displaying [3];• while avoiding collisions, and re-tasking of vehicles. A well designed MMI will support the increased functionality of a multiple-vehicle system while minimizing the impact on the user. When a single user can command, control, and monitor multiple unmanned vehicles simultaneously the true value of autonomous vehicles will be realized.In such cases the OCU should be able to provide the user with much more information than the visual streams usually provided in teleoperation applications. Such information include a correct status of the vehicle (as detected by proprioceptive and esteroceptive sensors), a complete list of the possible commands/actions and, if available a list of the advanced behavioural features that may be activated on the vehicle.Sensor PayloadBehavioural AlgorithmsDatabaseCommand Actions OCUFigure 1: OCU Design CompoenentsA typical OCU features subdivision is based on such an approach and classified in observer (or control), commander and superuser (or supervisor) functionalities [12].PAPER NBR - 8 PUB REF NBR (e.g. RTO-MP-IST-999)PAPER TITLE2.1 Observer moduleThe Observer module should provide the user with a complete awareness of remote robot(s) and environment conditions. Different information are required at this level:• Localization, Navigation and trajectory information: inform the operator about current position, velocity and motion strategies (if present) of the mobile vehicle. GPS position represented on map view, digital compass, 2/3D velocity vectors and other means of graphical representation result to be easier to be understood than textual messages;• Streams: video and audio stream are usually captured and provided to the user. Several types of CCD sensor may provide the remote OCU with different views and/or daylight/IR sensing capabilities. Usually no more than two principal streams [13] are simultaneously shown to the operator to reduce the level of attention required. In case of multiple robots/multiple cameras, the operator may switch the reference stream by choosing from a pool of snapshots;• Incremental maps of land topologies and any other GIS information retrieved by sensory payload onboard the vehicle;• Surrounding information: proximity detection, sonar, ladar may be shown as vehicle perspective graphs that maps to fields of potential surrounding the vehicle;• Group and enemies information: when multiple robot environments are concerned, the abilities to figure out on maps or relatively to the current robot position, the location of other devices allows the operator to improve the mission planing.2.2 Commander moduleBesides the critical commands (Usually Stop, Reset and Clear) that are typically made accessible from anywhere in the OCU other typical command that OCU should support include:• View switching• Zoom and Panning• Motion primitive (forward, left, right, backward)• Speed control• Calibration and configuration panels and OCU interfacesFurthermore, when appropriate, all interfaces have to provide accelerators (shortcuts) that allow experienced user to execute the same control action without following complex and slower paths. Some Observer/Commander modules allow interoperation by WEB interface thus integrating automatically encryption, modularity and portability of control features.2.3 Superuser moduleSuperuser module implements supervision and behaviour features on the robot. The higher level of autonomy is requires, the higher is the time to access the behaviour since it has to be programmed accordingly to a set of given parameters to precisely identify the task (e.g. Waypoint navigation, target PUB REF NBR (e.g. RTO-MP-IST-999) PAPER NBR - 9PAPER TITLEreaching,...).Therefore it is not required that superuser access should be directly available from buttons always visible on the OCU, they may be shown to the operator at request and when he is in the proper condition to program the device.4.0 EXISTING OCUSTo date hundreds of different mobile robots have been proposed in the scientific literature, each of them has a proper OCU. A complete review of all existing devices is therefore not feasible in this paper. In what follows a short review of some of them is proposed.3.1 Demo IIIEarly systems, such as Demo III [14], were controlled by rugged box that summarized the functionalities of a multimedia PC (Computing, Visualization, Joystick and Radio).Figure 1: Demo III OCUThe OCU offers the possibility of controlling several mission data: Map, mission graphics, location of cooperation vehicles and enemies; as well as of planning and control teleoperated motion and complex semi-autonomous missions.3.2 Man Portable Robotic SystemThe Man Portable Robotic System, documented the creation and the development of its OCU in several papers [15, 16]. The OCU is a single user, single robot system that offers an high level of robustness and easiness of use. The OCU is a simple 6-8 buttons user interface provided with a 5'' monitor display that allows the remote visualization of CCD streams.PAPER NBR - 10 PUB REF NBR (e.g. RTO-MP-IST-999)Figure 2: MPR System as shown in [15]It worth noting that after a preliminary version of the OCU with capacitive touch-buttons and head-up display, the second OCU issue presented an even more simpler design in order to face with mission critical applications.3.3 PDA Human Robot InterfaceRecently several mobile robots architecture deployed PDA systems to interact with the vehicle [17].Figure 3: PDA interactive OCUne of the biggest limitation of the PDAs is to achieve a rapid interaction among different observer and commander views. Typical PDA implementation balance performances with autonomy and are only provided with small performances processors. A Vision with sensory overlay screen also provides the operator with camera image fused with sensory feedback: ultrasonic and laser range finder sensors. In this case only frontal information are represented. When other direction sensors are required, robot camera must be rotated to view respective sector. Statistical analysis performed in combination with NASA also showed that information merging drastically improved performance during remote guidance tasks.3.4 Packbot extensionsyed MR unit both for research and applications in military field. Besides the The OCU includes a live video from PackBot’s color drive camera, data from the laser rangefinder, and Another OCU externsion for the Packbot are the PDA interface and the portable interface realized by [19].e 5: Portable Packbot OCUsThe portable solution is composed of three main components: a gamepad, an head-up display and aPackbot is the most emplo ruggeddized PC, Several OCUs have been developed to improve the control functionalities. The Wayfarer OCU [18], represented in figure, adds to the Packbot OCU the ability of receiving and displaying in real time UDP packets containing laser range data. 3D graphics, using OpenGL allow real-time rendering.Figure 4: Wayfarer OCUinformation from several sensors of the device. Laser Range finder allow the correct perception of somegraphical inputs (e.g edges) that may have been distorted by lens in the graphical feedback.Figur portable console that may run windows programs. The added value here of using head up display is in the perception of the object distance.5.0 CONCLUSIONS AND FUTURE WORKThe design of the OCU should optimize the situation awareness provided for the robotic team. If the operator needs to perform another non-robot task, the interface design should quickly provide the operator with situation awareness as the operator may have little bandwidth to monitor the autonomous system. In the future, it is advisable to test visualization systems for different robots in different missions and in different scenarios. In particular, it should be very interesting to investigate which characteristics of the environment require longer intervention times.REFERENCES[1] Yanco, H. and Drury, J. (2002), 'A taxonomy for human-robot interaction', Proceedings of the AAAI Fall Symposium on Human-Robot Interaction, 02—03.[2] Balch, T. and Parker, L., 'Robot Teams: From Diversity to Polymorphism', (eds), AK Peters, 2002.[3] Powell, D. Gilbreath, G. and Bruch, M. (2006), 'Multi-robot operator control unit', Proceedings of SPIE 6230, 562--569.[4] Casper, J. and Murphy, R. (2002), 'Workflow study on human-robot interaction in USAR', Robotics and Automation, 2002. Proceedings. ICRA'02. IEEE International Conference on 2.[5] Casper, J. & Murphy, R. (2003), 'Human-robot interactions during the robot-assisted urban search and rescue response at the World Trade Center', Systems, Man and Cybernetics, Part B, IEEE Transactions on 33(3), 367--385.[6] Burke, J. Murphy, R. Riddle, D. and Fincannon, T. (2004), 'Task Performance Metrics in Human-Robot Interaction: Taking a Systems Approach', Performance Metrics for Intelligent Systems Workshop 1.[7] H. Huang, H. ‘Terminology for Specifying the Autonomy Levels of Unmanned Systems’, NIST Special Publication 1011, 2004.[8] Dufourd, D. and Dalgalarrondo, A. (2006), 'Integrating human/robot interaction into robot control architectures for defense applications', First National Workshop on Control Architectures of Robots 1. [9] J. Crandall and M. Goodrich, ’Measuring the intelligence of a robot and its Interface’, in Proceedings of PerMIS 2003, Gaithersburg, MD, September, 2003.[10] M. Endsley, ‘Theoretical Underpinning of Situation Awareness: Critical Review (2000)’ in Mica R. Endsley and Daniel J. Garland (Eds.) Situation Awareness Analysis and Measurement. Lawrence Erlabaum Associates, Mahwah, New Jersey, pp. 3-32, 2000.[11] M. Endsley, B. Boltè and D. Jones, Designing for Situation Awareness. Taylor and Francis: London, UK, 2003.[12] Shenoy, S. Viswanadha, L. and Agah, A. (2006),'Graphical User Interfaces for Mobile Robots', Information Telecommunication and Technology Center, University of Kansas, Lawrence, KS.[13] Lundberg, C. Christensen, H. and Hedstrom, A. (2005), 'The use of robots in harsh and unstructured field applications', Robot and Human Interactive Communication, 2005. IEEE International。