Controlling the sensitivity of support vector machines

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增材制造镍基高温合金裂纹形成机理及控制方法

增材制造镍基高温合金裂纹形成机理及控制方法

增材制造镍基高温合金裂纹形成机理及控制方法1.增材制造过程中,镍基高温合金易于出现裂纹。

During additive manufacturing, nickel-based high-temperature alloys are prone to cracking.2.裂纹对零件的性能和可靠性会产生严重影响。

Cracks can severely affect the performance andreliability of the parts.3.裂纹主要形成于快速冷却过程中。

Cracks mainly form during rapid cooling.4.在增材制造过程中,要尽量避免快速冷却。

In additive manufacturing, it is important to avoid rapid cooling as much as possible.5.控制加热和冷却速度可以有效降低裂纹的发生率。

Controlling the heating and cooling rates can effectively reduce the occurrence of cracks.6.合适的预热可以减少材料的残余应力。

Proper preheating can reduce the residual stress in the material.7.合理的工艺参数设置对于裂纹的控制至关重要。

Proper process parameter setting is crucial for controlling cracks.8.对材料的选择也会影响裂纹的形成。

Material selection also affects the formation of cracks.9.使用精细的粉末和合适的喷嘴可以减少裂纹的产生。

Using fine powder and suitable nozzles can reduce the formation of cracks.10.合适的气氛保护可以有效预防氧化带来的损坏。

DNV-OS-C401(2010) 中文版(DNT部分)

DNV-OS-C401(2010) 中文版(DNT部分)

2013年4月SECTION 3 NON-DESTRUCTIVE TESTING第三章无损检测1.General 通则1.1 Scope 范围1.1.1 This section gives requirements for non-destructive testing.本章节给出了无损探伤的要求。

2. Non-Destructive Testing (NDT) 无损探伤测试(NDT)2.1General 通则2.1.1Prior to commencement of fabrication the contractor shall submit a plan for NDT, NDT proce dures and documents for NDT inspectors’ certification for acceptance by the purchaser. The progr amme shall contain information and documents for planning, controlling and reporting在装配前,卖方必须向买方递交NDT 图,NDT 工艺文件以及NDT人员资格证,并经卖方接受。

这个程序必须包括计划、控制和报告DNT 的信息和文件。

2.1.2 The inspection categories shall be defined in accordance with DNV-OS-C101 Sec.4 or DNV-O S-C201 Sec.4 and shall be specified in relevant design drawings.检测类别应根据DNV-OS-C101第四节或DNV-OS-C201第四节来划分,并指定相关图纸。

2.1.3Welds shall be subject to NDT in progress with fabrication. The results of these activities shal l be consecutively reported to the purchaser.在制造过程中,焊缝质量主要依据无损探伤试验,试验结果应不断报告给买方。

what is motor learning

what is motor learning

In: Kaivo Thomson, Timo Jaakkola & Jarmo Liukkonen (Eds.) Promotion of Motor Skills in Sports and Physical Education University of Jyväskylä, Finland Department of Sport Sciences,Research Unit of MotorSkills.Publications 2/2006. Pp. 9-18.WHAT IS MOTOR LEARNING?Timo JärvilehtoFaculty of Education and Kajaani University Consortium, University of Oulu, Finland timo.jarvilehto@oulu.fiSUMMARYIt is argued, on the basis of organism-environment systems theory, that motor learning doesn’t exist in the sense that it would be learning confined to the motor system only, and that it could be contrasted to other types of learning. Motor learning means learning of new acts, and each act consists of both motor and sensory constituents. Learning is a process that involves always the whole organism-environment system, leading to a new organization making new results of behavior possible. It is also stressed that all human learning has essentially a social character, developing in relations to other people, which forms the basis of motivation and self-esteem necessary for high-level performance. INTRODUCTION“Motor learning” is a term widely used in relation of learning of new skills, and gives the impression that motor learning is a specific form of learning. This may be seen in usual definitions of motor learning such as “Motor learning is the process of improving the smoothness and accuracy of movements” or “A motor skill is a skill that regards the ability of an organism to utilize skeletal muscles effectively”.Such definitions imply that human behavior may be divided in sensory and motor parts the latter one being the object of motor learning. However, we may ask what really is trained in motor learning situations. In fact, the object in the training a motor skill is not the ability to perform specific contractions of the muscles with associated movements of the limbs, but rather the accomplishment of certain behaviors of acts. A trainee trying to learn how to master the motor skill of jumping as far as possible is not really training the muscles of the body for specific movements, but he is rather trying to develop the ability to achieve a certain result, the maximal distance in jumping. This result may be achieved under different circumstances by different movements, and the same movement may have different significance depending on the situation.Thus, motor learning is not really “motor”, but the process of learning new acts for the achievement of specific results. An act, furthermore, always consists of a constellation of many components, only part of them being “motor”. In order to accomplish any act many other constituents are needed, belonging also to the sensory part of the nervous system.From the point of view of the ac complishment of an act “motor” and “sensory” are only anatomical divisions that cannot be functionally separated. It is also interesting to note that both muscles and senses have, in fact, both afferent and efferent innervation, afferent for muscles in the form of Ia afferents, for example, and efferent for senses in the form of efferent fibers controlling the sensitivity of receptors (see e.g. Järvilehto, 1999).TWO SYSTEMS OR ONE?The concept of motor learning is based on a functional“motor- sensory” dichotomy. Such a dichotomy is understandable if the theorizing starts with a primary organism-environment dichotomy, in which organism and environment are regarded as two different systems in interaction (Fig.1).Fig. 1 Organism and environment as two different systems.In this view “motor” means traffic from the organism to environment, whereas “sensory” means action from the environment to the organism. Such a division is based on our common sense intuition: here am I and outside me is located the environment. However, if we interested in learning of new acts we may ask if this kind of abstraction is useful after all.The theory of the organism-environment system (Järvilehto, 1998a,b; 1999; 2000) starts with a postulate that most conceptual problems in psychology are due to the common sense abstraction of organism and environment as two separate systems. This primary dichotomy leads to many other dichotomies and controversies that can be solved only by changing this two systems starting point. No organism can act without an environment, and every act consists of elements belonging both to the organism and the environment. Thus, an act as a system should be, just from the beginning, treated and analyzed as an undivided whole. We don’t have two systems in interaction, but just one system that is organized in relation to the result of behavior (Fig.2).Fig. 2. The theory of the organism-environment system. Any act is accomplished by a system consisting of both organismic and environmental elements.The architecture of the organism-environment system is determined by the result of behavior, not by such anatomical divisions as motor-sensory, for example. It is also this system in which mental processes are realized, and in which learning takes place, not in parts of the system. Thus, on this basis, the following definitions of the basic concepts may be presented:∙”Mental” is a process in the organism-environment system, in which ”inner”and ”outer” cannot be separated. Psychological concepts refer always to theorganization of the whole system involving both sensory and motor components.Perception and action, for example, are two sides of the same coin.∙“Learning” is a process of differentiation and widening of the organism-environment system making new results possible.∙“Sensory” is not related to information processing from the environment, but to joining of the organism with environment∙“Motor” motion is not based on efferent signals, but on reorganization of the whole organism-environment systemTHERE IS NO SEPARATE “MOTOR” LEARNINGOn the basis of the theory of the organism-environment system, there is no motor learning that could be contrasted with “sensory” learning, for example. Learning i s a process that involves always the whole organism-environment system, leading to a new organization making new results of behavior possible.Thus, it is also futile to try to find motor learning in the brain. From the psychological point of view, there is nothing “motor” in the m otor cortex, as little as there is anything “sensory” in the sensory cortices. The units in the brain do not carry out psychological operations; the neurons are only parts of a larger system, in which psychological operations are accomplished. During learning there are, of course, changes in thestructure of the nervous system and in the functioning of neural units, but these changes are related to the achievement of new results, not to separate psychological “functions”. In the learning process the neurons form new action systems making new results possible. And in this process both motor and sensory components are always necessary.On this basis we may have also a new look on learning of motor skills: This process is not related to movements as such, but rather to formation of sensory-motor integration in the form of action systems for specific results, being the target of the training process. Such systems are formed when the trainee acts in the teaching program by carrying out movements related to the result, but partially such systems may be formed also without the movements. In the latter case we speak about “mental” training. This kind of training is not at all more “mental” than the former one (i.e. when actual movements are performed), but it is related to the formation of parts of the action systems necessary in the final accomplishment of the object of training.As all “motor” learning is directed towards the accomplishment of certain results, the process is essentially prospective, i.e. it cannot be regarded as response to certain stimuli, but rather as a self-organizing process for the expected ends. The subject is not waiting for certain stimuli in order to act, but it is rather his action which renders certain environment components useful in the achievement of the result. This also explains why in many performances amazing speeds of movement are possible.EXAMPLE: IS READING A SENSORY OR MOTOR PROCESS?As an example of sensory-motor integration we may look at such a skilled process as reading: Is ”reading” a motor or sensory process? One could call it motor, because of the significance of eye movements and especially because the control of saccades is an essential component. However, from the traditional point of view, reading is conceived rather as a sensory process, as a process of transmission of information from the written text. However, from the present point of view, neither description is accurate.In our recent experiments (Holappa and Vierelä, 2006) we studied the reading process by recording eye movement parameters, reading speed, and delay from fixation to uttered word with three different types of text: 1) normal (“text written normally”), 2) scrambled (“txet wrttien in scr ab meld from”, and 3) continuous (“textwrittentogether”). It was assumed that the main differences in studied parameters should appear with the scrambled text if reading is based on linear and hierarchical sensory processing of textual information.Fig. 3 shows some of the results. In contrast to the hypothesis, 1) and 2) did not significantly differ in any reading parameters, whereas marked differences were found with 3) in most parameters studied. It was also significant that the delay between fixation to a word and its uttering was very short, on the average about 600 ms, indicating that there is not even time for any complicated processing of textual information after the fixation. Furthermore, this delay was maximal with the continuous text.Such results support the interpretation of reading as process of anticipation of meaning, in which fixation to a word is not a start, but rather the end of the prospective process of generation of meaning. Thus, reading is not a sensory or motor process, but an integrated process for the achievement of resultsSOME GENERAL ASPECTS OF THE LEARNING PROCESSIf learning is defined as differentiation and widening of the organism-environment system it is clear that learning cannot be sensory or motor, only, but the process of learning involves always many systemic constituents. Learning to master of a skill consists essentially of development of prospective organization of the organism-environment system for skilled sequences of results, in which sensory and motor components are integrated.It is also important to stress that from the point of view of the organism-environment theory human learning has essentially a social character and presupposes the existence of consciousness (see Järvilehto, 2000). According to the organism-environment theory, consciousness develops in cooperation with other people; thus, human learning is a process exceeding the borders of the individual organism-environment systems. It is this larger organization in which the human learning is realized, and therefore all efficient learning presupposes the participation of both the teacher and the pupil (or the trainer and the trainee).Fig. 4. The development of consciousness. Consciousness develops in a system that consists of several organism-environment systems directed towards achievement of common results. Communication is the tool for creating the system.From this it follows that the task of the trainer is not that of information transmission (“teaching” in the classical sense), but rather creation of the coo perative organization in which the learning resources of the trainee may be realized. An essential characteristic of this kind of process is the determination of the developmental possibilities of the trainee, and finding out his personal style in the process of achievement of the desired results in cooperation with the trainer.Coaching is not a process of transmission; it is rather a process of development of the pre-existing skills of the trainee in a larger organization consisting, in the beginning, of the trainer (and all other relevant people) and the trainee, but getting with continuing training more differentiated and narrow, until the trainee is able to achieve the results also without the immediate support of the associated people. Such a process was coined by Vygotski already in the beginning of the last century with the term “zone of proximal development”. However, according to the present view this development doesn’t mean a shift from external to internal control of behavior, as implied by Vygotski, but rather as a process of development of the personal aspect of performance.In conclusion, the development of mastering of motor skills is not a process of “motor” learning going on in the motor cortex of the trainee, for example, but rather a deeplysocial process directed towards creation of an integrative organization consisting of many participants. The brain is, of course, also an important aspect of the necessary conditionsof such an organization, but the learning process is not confined to the brain only, but it presupposes also many other necessary components, such as the body, environmental possibilities, social relations, etc. It is also this larger organization, in which the motivational factors and the self-esteem develop --- mastering of the skill as a consequence of result-oriented training, and motivation and self-esteem on the basis of relations to other people --- making eventually the high-level performance possible. POSSIBLE RESEARCH PROBLEMSOn the basis of the present theoretical account, the following central research problems may be formulated:⏹What are the critical components in formation of prospective organization for results?⏹Differences in prospective organization with different levels of mastering the skill.⏹Developmental differences: skill development.⏹Role of emotions (motivation) in creating the prospective organization.⏹Prospective and relational organization in teams of players.REFERENCESJarvilehto T (1998a) The theory of the organism-environment system: I.Description of the theory. Integrative Physiological and BehavioralScience, 33, 321-334.URL: http://wwwedu.oulu.fi/homepage/tjarvile/orgenv1.pdfJärvilehto T (1998b). The theory of the organism-environment system: II.Significance of nervous activity in the organism-environment system.Integrative Physiological and Behavioral Science, 33, 335-343.URL: http://wwwedu.oulu.fi/homepage/tjarvile/orgenv2.pdfJarvilehto, T. (1999). The theory of the organism-environment system: III.Role of efferent influences on receptors in the formation of knowledge.Integrative Physiological and Behavioral Science, 34, 90-100.URL: http://wwwedu.oulu.fi/homepage/tjarvile/orgenv3.pdfJarvilehto, T. (2000). The theory of the organism-environment system: IV.The problem of mental activity and consciousness. IntegrativePhysiological and Behavioral Science, 35, 35-57.URL: http://wwwedu.oulu.fi/homepage/tjarvile/orgenv4.pdfHolappa, E. and Vierelä, H. (2006) Miten lukeminen tapahtuu. Vertaileva tutkimus eri tekstityyppien yhteydestälukijan silmänliikkeisiin ja lukemisen kestoon. University of Oulu: Master’s thesis.。

外汇管理制度 英文

外汇管理制度 英文

外汇管理制度英文IntroductionThe foreign exchange market, also known as the forex market, is the largest and most liquid financial market in the world. It operates 24 hours a day, five days a week, and generates trillions of dollars in daily trading volume. As such, it plays a crucial role in the global economy and is an essential component of international trade and investment.The forex market allows participants to buy, sell, exchange, and speculate on currencies. It facilitates the conversion of one currency into another, enabling businesses, governments, and individuals to conduct cross-border transactions. However, due to the decentralized and global nature of the forex market, it is susceptible to a range of risks, including exchange rate fluctuations, interest rate differentials, and geopolitical events.As a result, effective forex management is essential for organizations and individuals to mitigate these risks, optimize their currency exposure, and achieve their financial objectives. This article will explore the key components of a forex management system and provide practical guidance on how to develop and implement such a system.Key Components of a Forex Management SystemA forex management system encompasses a range of processes, policies, and procedures designed to manage an organization's exposure to currency risk. It involves identifying, measuring, monitoring, and controlling foreign exchange risk to ensure that the organization's financial performance is not adversely impacted by currency fluctuations. The key components of a forex management system include:1. Risk Identification: The first step in managing forex risk is to identify the sources of exposure within the organization. This includes understanding the nature and extent of the organization's foreign currency transactions, such as sales, purchases, investments, and borrowings, as well as the potential impact of exchange rate movements on these transactions.2. Risk Measurement: Once the sources of exposure have been identified, the next step is to quantify the organization's forex risk exposure. This involves assessing the sensitivity of the organization's cash flows, profits, and balance sheet to changes in exchange rates, as well as evaluating the potential impact of other relevant factors, such as interest rates, inflation, and economic indicators.3. Risk Management: With a clear understanding of the organization's forex risk exposure, the next step is to develop and implement a risk management strategy. This may involve using a range of financial instruments, such as foreign exchange forwards, options, and swaps, to hedge against currency risk, as well as establishing operational controls and procedures to minimize exposure to forex risk.4. Risk Monitoring: Once a risk management strategy has been implemented, it is essential to monitor the effectiveness of the strategy and to regularly review and update the organization's forex risk management policies and procedures in response to changing market conditions, business activities, and risk profiles.Developing a Forex Management SystemDeveloping an effective forex management system requires a systematic approach that takes into account the organization's unique characteristics, risk appetite, and objectives. The following steps can help guide the development of a forex management system:1. Understand the Organization's Forex Risk Profile: The first step in developing a forex management system is to understand the organization's forex risk profile. This involves identifying the nature and extent of the organization's forex exposure, as well as the potential impact of currency fluctuations on the organization's financial performance.2. Set Objectives and Risk Tolerance: Once the organization's forex risk profile has been understood, it is essential to define clear objectives for the forex management system and to establish the organization's risk tolerance. This will help guide the development of a risk management strategy that is aligned with the organization's overall strategic and financial objectives.3. Design a Risk Management Framework: Based on the organization's objectives and risk tolerance, a risk management framework should be designed to outline the processes, policies, and procedures for managing forex risk. This may include establishing risk management guidelines, risk measurement and reporting requirements, and hedging policies and procedures.4. Implement Risk Management Practices: Once the risk management framework has been designed, it is essential to implement risk management practices that align with the organization's risk management strategy. This may involve using a range of financial instruments, such as forwards, options, and swaps, to hedge against currency risk, as well as implementing operational controls and procedures to minimize exposure to forex risk.5. Monitor and Review the Forex Management System: Once the risk management practices have been implemented, it is essential to monitor the effectiveness of the forex management system and to regularly review and update the organization's risk management policies, procedures, and practices in response to changing market conditions, business activities, and risk profiles.Best Practices for Forex ManagementIn addition to developing and implementing a forex management system, there are several best practices that organizations and individuals can follow to enhance their forex management capabilities, including:1. Develop a Deep Understanding of Forex Market Dynamics: To effectively manage forex risk, it is essential to develop a deep understanding of the factors that drive exchange rate movements, including economic indicators, interest rates, inflation, geopolitical events, and market sentiment. This will help organizations and individuals make informed decisions about their forex risk exposure and potential risk management strategies.2. Establish Clear Objectives and Risk Tolerance: It is essential to establish clear objectives for forex management and to define the organization's risk tolerance. This will help guide the development of a risk management strategy that is aligned with the organization's strategic and financial objectives and that takes into account the organization's appetite for risk.3. Diversify Currency Exposure: Diversification is a key principle of effective forex management. By diversifying currency exposure across multiple currencies, organizations and individuals can reduce their reliance on any single currency and mitigate the impact of adverse exchange rate movements.4. Utilize Risk Management Instruments: There are a range of financial instruments available to manage forex risk, including forwards, options, and swaps. Organizations and individuals should consider utilizing these instruments to hedge against currency risk and to protect against adverse exchange rate movements.5. Implement Robust Risk Monitoring and Reporting: Effective risk monitoring and reporting practices are essential for managing forex risk. Organizations and individuals should establish robust processes for monitoring currency exposure, measuring risk, and reporting on the effectiveness of the forex management system to key stakeholders.ConclusionEffective forex management is essential for organizations and individuals to mitigate currency risk and achieve their financial objectives. By developing and implementing a comprehensive forex management system that encompasses risk identification, measurement, management, and monitoring, as well as following best practices for forex management, organizations and individuals can better manage their exposure to currency risk and position themselves for success in the global marketplace.。

学术英语(管理)含课后答案Unit

学术英语(管理)含课后答案Unit
学术英语与通用英语(General English)不同,它更侧重于特定学科领域的语言知识和技能,例如科学、 工程、医学、法律等。学术英语的语言特征包括专业术语、复杂的句型结构、严谨的逻辑表达等。
The Importance of Academic English
学术英语对于学生的学术发展至关重要。在全球化的时代,许多学科领域的最新 研究成果和进展都以英语发表,因此学生需要掌握足够的英语学术能力才能跟上 学术前沿。
03
The Application of Academic English in
Management
The necessity of academic English in management
Globalization
As the world becomes more interconnected, the need for English as a common language for business communication has increased. Academic English provides the necessary vocabulary and language skills required for effective communication in management.
Managing across different cultures can be challenging, as cultural norms and business practices vary. Academic English should be used with caution and sensitivity to cultural differences, ensuring that communication is culturally appropriate.

数字调频收音机

数字调频收音机

摘要现如今随着时代的发展,收音机已经遍布于家家户户,然而人们所使用的大多模拟调谐制式的,在收音效果上面还有许多的不足,为了使得收音效果更加,因而出现了数字调谐收音机。

而本次设计的数控调频收音机的收音电路主要是通过STC89C52单片机来控制频率的选择、声音的大小;收音电路内部所使用的芯片为RDA5807M,使得单片机与收音电路之间通过IIC通信协议进行通信的,故使得该数控收音机比一般模拟收音机在频率的选择和声音的控制上更为准确。

由于该收音机大部分都是由集成化电路所组成,因而减少了由于手工布线造成元器件间的相互干扰,使其具有噪音消除、低音增强、灵敏度高、噪声小、抗干扰能力强等优点;其收音范围为(76-108MHz),体积小巧,非常适合于随身携带。

关键词:数控收音机,调频,IIC通信协议AbstractNowadays, with the development of the timesthe radio has been spread all over each and every family. These people use most are analog tuning system and have many shortcomings. In order to make the sound sounds more good, a digital radio appears. Through the STC89C52 single-chip microcomputer he radio circuit NC FM radio is mainly controlled control the selection of frequency, the size of the sound. The radio circuit inside is the chip RDA5807M which can make the MCU and radio circuit through the IIC communication protocol, so that the NC radio is more accuratethan general analog radio in controlling the selection and the sound frequency. As the radio is mostly composed of integrated circuit, it can reduce the manual wiring causing mutual interference between the components which has the advantages of eliminating noise, bass boost, high sensitivity, low noise, strong anti-jamming ability and so on.The radio range is very wide(76-108MHz). It has small size so it is very suitable for carry on.Key words:Digital radio, FM,IIC目录第1章绪论 (1)1.1 数控收音机背景 (1)1.2 数控收音机的国内外发展状况 (2)1.3 主要设计内容和要求 (3)第2章设计方案对比与理论分析 (4)2.1 设计方案对比 (4)2.2 收音机系统原理 (5)2.3 系统架构 (6)2.4 系统各部分的理论分析 (7)2.4.1 单片机最小系统分析 (7)2.4.2 显示模块 (8)2.4.3 收音电路 (9)第3章收音电路设计 (10)3.1 收音电路 (10)3.1.1 收音电路原理 (10)3.1.2 收音电路模块化引脚分析 (10)3.2 收音模块应用电路设计 (11)第4章控制电路设计 (13)4.1 电路控制模块设计 (13)4.2 显示模块设计 (14)4.3 电源模块设计 (15)第5章软件设计 (16)5.1 IIC通信协议分析 (16)5.2 程序流程图 (18)5.2.1 主程序流程图 (18)5.2.2 收音电路流程图设计 (19)5.3 系统主程序 (20)第6章系统调试 (24)6.1 硬件调试 (24)6.2 软件调试 (25)6.3 结果分析 (26)结论 (27)参考文献 (28)致谢 (30)附录 (31)第1章绪论1.1 数控收音机背景1888年德国科学家赫兹,发现了无线电波的存在。

高考英语完形填空精英训练精品题(16)及答案

高考英语完形填空精英训练精品题(16)及答案

2014高考英语完形填空精英训练精品题(16)及答案完形填空------AA strange thing happened to Henry yesterday. He was on a bus and to __1__. So he stood up and rang the bell. __2__ make sure the driver heard him, he rang it twice, but the bus __3__ stop. And the conductor came and shouted __4__ him.The conductor was __5__ angry and spoke __6__ fast that Henry didn’t understand __7__. The bus stopped at the next bus and Henry got off. As he got off he heard someone said, “ I think he __8__ a foreigner.”When Henry got __9__, he told his wife about it.“__10__ times did you ring the bell?” his wife asked.“Twice,” said Henry.“ Well, that’s the signal (信号) __11__ the driver __12__ on.” His wife explained, “Only the conductor __13__ to ring the bell twice. That’s why the conductor __14__ so angry!”Henry nodded(点头). “__15__,” he said.名师点评本文讲述了一位外国人在乘车时遇到的麻烦。

基于PLC的液位控制系统毕业设计论文

基于PLC的液位控制系统毕业设计论文

摘要在工业生产过程中,液位变量是最常见、最广泛的过程参数之一。

在油工业、化工生产、电力工程、机械制造和食品加工等诸多领域中,人们都需要对各类流体的液位高度进行检测和控制。

由于其具有工况复杂、参数多变等特点,它对控制调节器要求极高。

针对人工控制液位的准度较低、速度较慢、灵敏度偏低等一系列问题。

本文提出了基于PLC的液位控制系统,系统主要通过将液位传感器检测到的电信号通过接口送入PLC中,经过A/D转换成数字信号,随后送入数字PID调节器中,经PID算法后将控制量经过D/A转换成水泵电机转速相对应的电信号送入水泵电机来控制水泵转速,最终达到控制液位的目的。

通过仿真和分析结果表明本文所设计系统能够正常运行并且达到了设计的目的,能够准确、快速地控制液位,克服了传统液位控制系统的很多弊端。

在工程实际中,应用最为广泛的调节器控制规律为比例、积分、微分控制,简称PID控制。

PID控制器以其结构简单、稳定性好、工作可靠、调整方便而成为液位控制的主要技术之一。

可编程控制器是一种应用广泛非常的自动控制装置,它将传统的继电器控制技术、计算机技术和通讯技术融为一体,具有控制能力强、操作灵活方便、可靠性高、适宜长期连续工作的特点,非常适合液位控制的要求。

目前常用的可编程控制器中,西门子公司的S7-200以其编程软件STEP7的简洁易用和通信网络的功能强大得到业内人十的普遍认可。

关键词:西门子S7-200;PID;液位变送器AbstractIn industrial processes, the level variables are the most common, the most widely used process parameters. In the oil industry, chemical industry, power engineering, machinery manufacturing and food processing and many other areas, people need all kinds of fluid liquid level detection and control. Because of its complexconditions, parameter changing characteristics, its control regulator demanding. Formanual control of the lower level of accuracy, speed, slow, low sensitivity and other issues. In this paper, based on the level of PLC control system, the system mainly thro ugh the level sensor detects the electrical signals through the interface into the PLC, after A / D converted into digital signals, then sent to a digital PID regulator by PID After controlling the amount of algorithms through D / A converter to the pump motor speed into an electrical signal corresponding pump motor to control the pump speed, and ultimately achieve the purpose of the control level. Through simulation and analysis results show that this system is designed to function properly and achieve the purpose of the design that can accurately and quickly control the liquid level, to overcome the many drawbacks of traditional level control system.In engineering practice, the most widely regulator control law is proportional, integral, differential control, referred to as PID control. PID controller with its simple structure, good stability, reliable, easy to adjust and become one of the major technical level control. Programmable controller is a very wide range of automatic control device applications, will traditional relay control technology, computer technology and communication technology integration, with a strong ability to control, flexible operation, high reliability, suitable for long-term continuous work features, ideal for liquid level control. The commonly used programmable controller, S7-200 programming software is simple to use and its communications network functions Siemens STEP7 powerful people in the industry get ten universally accepted.Keywords:Siemens S7-200, Level Transmitter, PID1引言1.1题研究背景、意义和目的为了解决人工控制的控制准度低、控制速度慢、灵敏度低等一系列问题。

[整理]科技名词英语

[整理]科技名词英语

科技名词英语控温运输||transport under controlled temperature控制爆破||controlled blasting控制泵||control pump控制变压器||control transformer控制点||controlling point控制电机||control electric machine控制电缆连接器||control cable coupling控制电路||control circuit控制电路库用插座||control circuit socket for shed supply控制电源||control source控制电源电流表||control supply ammeter控制电源电压表||control supply voltmeter控制电源隔离开关||isolating switch for control supply控制对象||controlled object控制工程||dominant project控制机构||control mechanism控制盘||control panel控制区间||control section,controlling section控制室||control cabin控制台||control desk控制台单元||control desk element控制台室||control room控制箱||control box控制信号||control signal控制信号检波器||control signal detector控制站||control station控制周期||control cycle控制字符||control character扣车条件||specified conditions for detaining cars扣件||rail fastening; 又称“中间联结零件”。

创新 抗病机制 策略

创新 抗病机制 策略

创新抗病机制策略英文回答:Innovation is a crucial aspect of any field or industry. It involves coming up with new ideas, products, or processes that can bring about positive changes and advancements. In the context of disease resistance, innovation plays a vital role in developing effective mechanisms and strategies to combat diseases.One innovative approach to enhance disease resistanceis through the use of genetic engineering. Scientists can manipulate the genes of plants or animals to introduce resistance against specific diseases. For example, genetically modified crops can be engineered to produce toxins that target pests or pathogens, providing a natural defense mechanism. This innovation has revolutionized agriculture and helped farmers increase their crop yields while reducing the need for chemical pesticides.Another innovative strategy is the development of vaccines. Vaccines stimulate the immune system to recognize and fight against specific pathogens. They have been instrumental in preventing the spread of infectious diseases such as polio, measles, and influenza. The continuous research and development of new vaccines are essential to stay ahead of emerging diseases and ensure global health security.Furthermore, innovation in diagnostic tools and techniques has greatly improved disease detection and monitoring. Advanced technologies such as PCR (polymerase chain reaction) and next-generation sequencing allow for rapid and accurate identification of pathogens. This enables early intervention and treatment, preventing the further spread of diseases. For instance, the development of rapid COVID-19 tests has been crucial in controlling the pandemic and saving lives.In addition to technological innovations, adopting new strategies and approaches is also important in combating diseases. One such strategy is the One Health approach,which recognizes the interconnectedness of human, animal, and environmental health. By addressing diseasesholistically and considering their origins and transmission pathways, we can develop more effective prevention and control measures. This approach has been particularly relevant in dealing with zoonotic diseases, such as Ebola and COVID-19.中文回答:创新是任何领域或行业的关键因素。

诺瓦科技LED视频控台C1规格书英文版

诺瓦科技LED视频控台C1规格书英文版

Trademark
is a trademark of Xi’an NovaStar Tech Co., Ltd.
Statement
Xi’an NovaStar Tech Co., Ltd. You are welcome to use the product of Xi’an NovaStar Tech Co., Ltd. (hereinafter referred to as NovaStar). This document is intended to help you understand and use the product. For accuracy and reliability, NovaStar may make improvements and/or changes to this document at any time and without notice. Any problem in use or any good suggestion, please contact us through ways provided in the document. We will do our utmost to solve the problems and adopt the suggestions after evaluation as soon as possible.
Input power
AC 100~240V, 50/60Hz
Power consumption
50 W
Operating temperature 0°C–50°C
Storage temperature
-20°C–60°C
Humidity
0%–95% RH

多发伤抢救vipco流程

多发伤抢救vipco流程

多发伤抢救vipco流程When it comes to the process of rescuing a VIPCO (Very Important Person or Celebrity) who has suffered multiple injuries, it is crucial to have a well-organized and efficient plan in place. The first and most important step in the process is to ensure the safety and well-being of the VIPCO. This involves assessing the extent of their injuries and providing immediate medical attention to stabilize their condition. This may involve administering first aid, controlling bleeding, and ensuring that the VIPCO is breathing properly.Once the VIPCO's condition has been stabilized, the next step is to transport them to the nearest medical facility for further treatment. This may involve callingfor an ambulance or arranging for a medical helicopter to transport the VIPCO to a hospital equipped to handle their specific injuries. It is important to ensure that the transportation process is as smooth and efficient as possible, as any delays could have serious consequences forthe VIPCO's health and well-being.In addition to providing immediate medical attention and arranging for transportation, it is also important to notify the VIPCO's family and/or management team of the situation. This involves keeping the VIPCO's loved ones informed about the extent of their injuries, their current condition, and the medical treatment they are receiving. This communication is crucial for providing emotional support to the VIPCO and their loved ones during this difficult time.Another important aspect of the VIPCO rescue process is coordinating with the medical team at the hospital to ensure that the VIPCO receives the best possible care. This may involve providing the hospital with detailed information about the VIPCO's injuries, medical history, and any specific needs or preferences they may have. It is important to work closely with the medical team to ensure that the VIPCO receives personalized and effective treatment.Furthermore, it is important to consider the impact of the VIPCO's injuries on their career and public image. This may involve working with the VIPCO's management team to handle any press inquiries or public statements about the incident. It is important to handle these communications with sensitivity and professionalism, in order to protect the VIPCO's privacy and reputation during this difficult time.Overall, the process of rescuing a VIPCO who has suffered multiple injuries is a complex and challenging task that requires careful coordination and communication. By focusing on the safety and well-being of the VIPCO, coordinating with medical professionals, and providing support to their loved ones, it is possible to ensure the best possible outcome for the VIPCO during this difficult time.。

面对控制欲很强的领导作文

面对控制欲很强的领导作文

面对控制欲很强的领导作文英文回答:Facing a leader with strong controlling tendencies can be a challenging situation. It is important to handle such a situation with tact and diplomacy. Here are a few strategies that can be effective in dealing with a controlling leader.Firstly, it is crucial to maintain open and clear communication with the leader. Clearly express your ideas, opinions, and concerns, while being respectful and professional. This can help in establishing a healthy working relationship and may even lead to a better understanding between you and the leader.Secondly, it is important to be proactive and take initiative in your work. By demonstrating your competence and ability to handle responsibilities independently, you can gain the trust and confidence of your controllingleader. This may help in reducing their need to micromanage and control your every move.Furthermore, it is essential to focus on building a strong network of support within the organization. Seek guidance and advice from colleagues and mentors who have experience dealing with controlling leaders. They may provide valuable insights and strategies to cope with the situation effectively.In addition, it is important to remain calm and composed when faced with a controlling leader. Avoid reacting negatively or defensively to their behavior. Instead, try to understand their perspective and motivations. This can help in finding common ground and resolving conflicts in a more constructive manner.Lastly, it is important to take care of yourself and prioritize your well-being. Dealing with a controlling leader can be emotionally draining, so it is crucial tofind ways to manage stress and maintain a healthy work-life balance. Engaging in activities outside of work that bringyou joy and relaxation can help in coping with the challenges posed by a controlling leader.中文回答:面对控制欲很强的领导是一种具有挑战性的情况。

葡萄炭疽病菌(Colletotrichum spp.)种群对多菌灵的抗药性监测

葡萄炭疽病菌(Colletotrichum spp.)种群对多菌灵的抗药性监测

果树学报2021,38(2):242-249Journal of Fruit ScienceDOI:10.13925/ki.gsxb.20200324葡萄炭疽病菌(Colletotrichum spp.)种群对多菌灵的抗药性监测杨敬辉1,许媛1,肖婷1,褚姝频2,芮东明1,姚克兵1*(1江苏丘陵地区镇江农业科学研究所,江苏句容212400;2江苏省植保植检站,南京200000)摘要:【目的】阐明江苏丘陵地区葡萄炭疽病菌(Colletotrichum spp.)种群(GG)对多菌灵的抗药性流行动态及抗性分子机制。

【方法】采用区分剂量法和菌丝生长速率法分别测定GG的抗药性流行动态和敏感性;田间人工接种GG后再检测回分离菌株对药剂敏感性的方法评价GG的抗药性流行演化;药剂作用标靶基因序列分析阐明抗性分子机制。

【结果】2013年和2017年GG对多菌灵的EC50均值(ρ)分别为0.5285mg·L-1和7.7878mg·L-1。

GG对多菌灵的抗性菌株比率从2013年的2.34%上升至2017年的32.21%。

2017年和2018年多菌灵接种抗性菌株处理的防效分别为0.64%和4.18%。

回分离GG中抗性菌株/敏感菌株的比率2017年和2018年分别为65.00%和68.18%,均高于接种比率50%。

抗性菌株靶标基因(TUB2)第198位的谷氨酸突变成丙氨酸(E198A),或第200位的苯丙氨酸突变成络氨酸(F200Y)。

【结论】江苏丘陵地区GG对多菌灵已形成抗药性流行。

多菌灵持续施用是GG田间抗药性流行的驱动因子。

GG抗性菌株标靶基因突变类型为E198A或F200Y。

关键词:葡萄;炭疽病菌;多菌灵;抗药性监测;分子机制中图分类号:S663.1文献标志码:A文章编号:1009-9980(2021)02-0242-08Resistance monitoring of Colletotrichum spp.population to carbendazim in grape vineyardsYANG Jinghui1,XU Yuan1,XIAO Ting1,CHU Shupin2,RUI Dongming1,YAO Kebing1*(1Zhenjiang Institute of Agricultural Sciences of Jiangsu,Jurong212400,Jiangsu,China;2Jiangsu Plant Protection and Quarantine Sta-tion,Nanjing200000,Jiangsu,China)Abstract:【Objective】Grapevine anthracnose caused by Colletotrichum spp.species complex popula-tion(GG)has been the main disease during the grapevine spike stage in the hilly area of Jiangsu prov-ince.In recent years,the controlling failure of common chemicals to the disease has caused serious yield loss.Therefore,it has become an important research target to clarify the evolution,epidemic dy-namics and molecular mechanism of resistance of GG to benzimidazole fungicide,and to provide deci-sion-making basis for resistance control.【Methods】Employing the methods of discriminative dose(a concentration that fully inhibits mycelial growth of the sensitive isolates)and effective inhibition medi-um concentration(inhibits mycelia growth by50%relative to the control,EC50),the EC50values were identified to distinguish sensitivity and sensitive baseline migration to carbendazim.According to previ-ous studies,the discriminatory concentration of carbendazim was10mg·L-1.Then EC50values of car-bendazim were determined from98isolates and34isolates in2013and2017,respectively.Carbendaz-im solution was added to PDA to produce final active ingredient concentrations of0,0.04,0.12,0.37,1.11,3.33,10.00and30.00mg·L-1.For each isolate,three replicates per concentration were used.Theconidia suspension of sensitive,resistant and mixed isolates(the resistant isolate and sensitive isolate with the same conidia concentration were mixed in equal volume)was inoculated during young berry 收稿日期:2020-08-13接受日期:2020-11-23基金项目:江苏现代农业(葡萄)产业技术体系(JATS[2020]305);江苏省“333工程”资助项目(BRA2020167)作者简介:杨敬辉,男,研究员,博士,研究方向为植物保护。

情感技巧英语翻译

情感技巧英语翻译

情感技巧英语翻译Emotional Intelligence in English TranslationEmotional intelligence (EI) is a critical skill set that involves the ability to recognize, understand, and manage our own emotions and the emotions of others. In the context of English translation, EI plays a significant role in conveying the true essence and subtleties of the original text. Here's how emotional intelligence can be applied to English translation:1. Empathy: Translators with high empathy can better understand the emotions behind the text, allowing them to choose words and phrases that resonate with the same feelings in English.2. Self-Awareness: Being aware of one's own emotional reactions to the text can help a translator avoid projecting personal feelings into the translation, ensuring a more accurate and objective rendering.3. Self-Regulation: Controlling emotions is vital when translating sensitive or provocative content. A translator must remain neutral and focused on the text's message, not allowing personal biases to influence the translation.4. Motivation: A motivated translator is more likely to engage deeply with the text, seeking to understand thenuances and emotional tones to convey them effectively in English.5. Social Skills: Good social skills can help a translator work effectively with authors, editors, and other team members, facilitating a collaborative process that can enhance the emotional accuracy of the translation.6. Adaptability: Emotional intelligence allows translators to adapt their style to the emotional content of the text, whether it's a heartfelt novel or a technical manual.7. Cultural Sensitivity: Understanding cultural differencesin emotional expression is crucial for accurate translation. EI helps translators to navigate these differences and choose the most appropriate English expressions.8. Active Listening: In translation, this means being attentive to the underlying emotions and intentions of the original text, ensuring they are heard and conveyed in the target language.9. Nonverbal Cues: Recognizing and interpreting nonverbal cues in the source text, such as tone and rhythm, can help a translator capture the emotional impact of the original work.10. Conflict Resolution: EI can help translators resolve disagreements with team members or clients by understanding the emotional undercurrents of the situation and finding a mutually acceptable solution.In summary, emotional intelligence is not just about managing feelings; it's a powerful tool for enhancing the quality of English translations by ensuring that the emotional depth and subtlety of the original text are preserved and effectively communicated to the target audience.。

英语作文-环境风险评估与管控措施

英语作文-环境风险评估与管控措施

英语作文-环境风险评估与管控措施Environmental risk assessment and management are critical components in the sustainable development of any project or activity that interacts with the natural world. The process involves identifying potential environmental hazards, evaluating their possible impacts, and implementing control measures to mitigate or eliminate the risks.Identification of Environmental Risks。

The first step in environmental risk assessment is to identify potential hazards. These can range from chemical spills, air and water pollution, to habitat destruction and biodiversity loss. The identification process requires a thorough understanding of the project's scope, the materials used, and the methods of operation.Evaluation of Potential Impacts。

Once the hazards are identified, the next step is to evaluate their potential impacts on the environment. This involves considering the severity and duration of the impact, the sensitivity of the local ecosystem, and the resilience of the affected environment. The evaluation must be based on scientific data and robust analytical methods to ensure accuracy.Implementation of Control Measures。

controlling 的英语作文

controlling 的英语作文

controlling 的英语作文Controlling is a fundamental aspect of human behavior and decision-making. It is the ability to regulate and manage our actions, thoughts, and emotions in order to achieve our desired goals and outcomes. In today's fast-paced and complex world, the need for effective control over our lives has become increasingly important.One of the primary benefits of controlling is the sense of empowerment and personal agency it provides. When we have control over our lives, we feel more confident, resilient, and capable of navigating the challenges and uncertainties that come our way. This sense of control can help us manage stress, reduce anxiety, and maintain a positive outlook on life.Moreover, controlling can also lead to improved decision-making and problem-solving skills. By having a clear understanding of our goals and the steps required to achieve them, we can make more informed and strategic choices. This can be particularly beneficial in professional and academic settings, where the ability to plan, prioritize, and execute tasks effectively can be the difference between success and failure.However, it is important to note that controlling can also have its drawbacks if taken to an extreme. Excessive control can lead to feelings of rigidity, inflexibility, and a lack of adaptability. In some cases, it may even result in the suppression of creativity, spontaneity, and the ability to embrace change.To strike a balance, it is essential to develop a healthy and balanced approach to controlling. This involves recognizing the importance of control while also being open to flexibility, adaptability, and the acceptance of uncertainty. It means setting realistic and achievable goals, while also being willing to adjust those goals as circumstances change.One effective way to achieve this balance is through the practice of mindfulness. Mindfulness involves being present in the moment, observing our thoughts and emotions without judgment, and responding to situations with a calm and centered approach. By cultivating mindfulness, we can become more aware of our impulses to control and learn to let go of the need for absolute certainty or predictability.Additionally, developing strong self-awareness and emotional intelligence can also be beneficial in managing our need for control. By understanding our own strengths, weaknesses, and emotional triggers, we can learn to regulate our responses and make moreinformed decisions.In conclusion, controlling is a complex and multifaceted aspect of human behavior that can have both positive and negative consequences. By striving for a balanced and flexible approach, we can harness the benefits of controlling while avoiding its potential pitfalls. Through the development of mindfulness, self-awareness, and emotional intelligence, we can learn to navigate the challenges of controlling in a way that empowers us to live more fulfilling and meaningful lives.。

氨康源氨基酸固体饮料 中英文对照

氨康源氨基酸固体饮料  中英文对照

1、解酒护肝型氨康源氨基酸固体饮料,以人体必需氨基酸为基础的科学配方,通过现代科技手段,充分的保证了氨基酸的多样性、必需性、高营养性,同时也解决了在饮料中的稳定性,并且可充分发挥氨基酸在溶液中易吸收性,是一种全新低热量高营养性护肝解酒饮料。

饮料中含有肝脏所需要的解救氨基酸,同时也含有人体肝脏细胞的功能性营养元素,对肝细胞是很好的保护作用,同时解决饮酒后对小脑和纹状体的损害,减少身体对酒精的依赖性,有减轻酒精中毒的作用,调节机体对酒精的刺激,促进酒后机体的恢复,减少酒后的疲乏、胃肠紊乱、记忆力下降等等的酒后症状,同时减轻因为酒精中毒引起的手震颤等等现象。

1. The solid drink of anti-inebriation and liver protective type employs the scientific formula based on the human essential amino acids, through modern scientific methods; it is fully guaranteed the variety, essentiality, and high nutrition. Meanwhile, it keeps stability of the amino acids in the solution, and fully takes the advantages of their solubility inside the solution. It is an all new low calories, high nutrition drink of anti-inebriation and liver protection.The drink contains amino acids of salvation pathway that are needed in the liver. There are also functional nutritious elements of human liver in the drink. At the same time, the drink solves the damage problems of alcohol to the cerebellum and corpus striatum. It decreases the dependence of the body to alcohol. It has the effects on alleviating the alcohol intoxication, body adjusting to the alcohol stimuli, improving the body recovery after alcohol, reducing the post-alcohol symptoms of fatigue, gastro-intestinal disorders, and memory decrease, etc. It can also ease the hand tremors caused by alcohol intoxication, etc2、氨康源氨基酸饮料,以人体必需氨基酸为基础的科学配方,通过现代科技手段,充分的保证了氨基酸的多样性、必需性、高营养性,同时也解决了在饮料中的稳定性,并且可充分发挥氨基酸在溶液中易吸收性,是一种全新低热量高营养性抗疲劳饮料。

如何对待脑炎患者英语作文

如何对待脑炎患者英语作文

如何对待脑炎患者英语作文Title: How to Care for Patients with Encephalitis。

Encephalitis is a serious medical condition that requires attentive and compassionate care. When dealing with patients suffering from encephalitis, it is crucial to approach their treatment and support with empathy and understanding. Here are some key aspects to consider in caring for these individuals:1. Medical Attention and Monitoring:The foremost priority in caring for encephalitis patients is ensuring they receive appropriate medical attention. This includes timely diagnosis, treatment with antiviral or antibiotic medications if applicable, and close monitoring of their condition. Regular assessments of neurological function, vital signs, and overall well-being are essential to gauge the progress of the illness and adjust treatment as needed.2. Symptom Management:Encephalitis can manifest with a range of symptoms, including fever, headache, confusion, seizures, and altered consciousness. Effective symptom management is vital to alleviate discomfort and promote recovery. This may involve administering medications to reduce fever and alleviate pain, as well as implementing measures to prevent complications such as seizures or respiratory distress.3. Nutritional Support:Patients with encephalitis may experience difficulty eating or swallowing due to neurological impairment. Providing nutritional support, such as offering soft or pureed foods, ensuring adequate hydration, and, if necessary, using feeding tubes, can help maintain their nutritional status and support healing. Collaborating with dietitians and speech therapists can ensure that dietary needs are met while addressing any swallowing difficulties.4. Neurorehabilitation:Many individuals with encephalitis require neurorehabilitation to regain lost functions and maximize their recovery potential. This may involve physical therapy to improve mobility and strength, occupational therapy to enhance daily living skills, and speech therapy to address communication challenges. Tailoring rehabilitation programs to each patient's specific needs and abilities is essential for optimal outcomes.5. Psychosocial Support:Encephalitis can have profound effects on patients' mental and emotional well-being, as well as on their families' coping mechanisms. Providing psychosocial support is crucial in helping patients navigate the challenges they face and cope with the psychological impact of their illness. This may involve counseling, support groups, and interventions to address anxiety, depression, or cognitive changes.6. Family Involvement and Education:Involving patients' families in their care is essential for providing holistic support and facilitating continuity of care. Educating family members about encephalitis, its symptoms, treatment, and potential complications empowers them to participate actively in the patient's care and advocate for their needs. Providing resources and guidance on how to support their loved one's recovery at home can also enhance the transition from hospital to home care.7. Long-Term Follow-Up:Encephalitis can have long-lasting effects, and some patients may require ongoing medical monitoring and support after discharge from the hospital. Ensuring access to appropriate follow-up care, including regular neurological evaluations and screenings for potential complications, is essential for detecting any changes in the patient's condition and addressing them promptly.In conclusion, caring for patients with encephalitis requires a multidisciplinary approach that addresses their medical, physical, psychological, and social needs. By providing comprehensive care and support, healthcare professionals can optimize outcomes and enhance the quality of life for individuals affected by this challenging condition.。

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2 Sensitivity versus speci city
The performance of a binary classi er is usually quantied by its accuracy during the test phase, i.e. the fraction of misclassi ed points on the test set. However, as we have just remarked, the signi cance of the two types of misclassi cations may well be di erent. Consequently, the performance of such systems are best described in terms of their sensitivity and speci city quantifying their performance for false positive and false negatives. Systems can then be compared by using a ROC (Receiver Operating Characteristic) analysis. These techniques are based on the consideration that a test point always falls into one of the following 4 categories: False Positive (FP) if the systems labels it as a positive while it is a negative; False Negative (FN) if the system labels it as a negative while it is a positive; True Positive (TP) and True Negative (TN) if the system correctly predicts the label. In the following we will use T P , T N, F P , F N to denote the number of true positives, true negatives, false positives and false negatives, respectively. Note that with this notation the number of positive points in the test set can be written as T P +F N, the number of negative points as T N +F P , and the test set size as T P +F P +T N +F N: A confusion matrix can be used to summarize the performance of a learning machine:
1995]. For noise-free classi cation tasks they work by
mapping the training points into a high-dimensional fea-
ture space where a separating hyperplane (w; b) is found
detection Schmidt,
1O9s9u6n]a.
They exhibit a remarkable resistance to over tting, a fea-
ture explained by the fact that they directly implement
the principle of Structural Risk Minimization Vapnik,
In this paper we will present two new techniques for controlling this trade-o between false positives and false negatives with Support Vector Machines. In section 3 we will compare these methods on real life medical datasets.
a small norm of w). One consists of setting an upper
bisoruendducoend.thTehseizoethoefrthcoensiis,tssointhaeddiningueancdeiaogfoonuatlleielers-
ment to the matrix K, e ectively mapping the data into
follosmwuibinnjiegmctoipzteotimiyCzia(Pthiwon;ikxp+irioh+bwlbe;)mwsi: 1 ? i, with i 0
(3)
with k = 1 and k = 2. A theoretical analysis of both algaonrdithCmrissthiaansinrieceSnhtalyweb-TeeanyloprroavniddedCbriystiSahnainwie,-T1a9y9l9o]r, based on the concept of \margin distributions".
which maximises the margin or distance from the closest
data points. Hyperplanes can be represented in feature
space (a Hilbert space) by means of kernel functions (dot
Controlling the Sensitivity of Support Vector Machines
K. Veropoulos, C. Campbell, N. Cristianini
Department of Engineering Mathematics, Bristol University, Bristol BS8 1TR, United Kingdom
Abstract
For many applications it is important to accurately distinguish false negative results from false positives. This is particularly important for medical diagnosis where the correct balance between sensitivity and speci city plays an important role in evaluating the performance of a classi er. In this paper we discuss two schemes for adjusting the sensitivity and speci city of Support Vector Machines and the description of their performance using receiver operating characteristic (ROC) curves. We then illustrate their use on real-life medical diagnostic tasks.
products between mapped pairs of input points xi):
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