Theme 1--- Reseaux et systemes

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HSE管理体系简介

Organiza tion StructureAlcohol
& Drugs Policy
Audit Plans
HSE Policy
HAZARDS &
EFFECTS MGMT.
Plan Objectives
HSE
Health Targets Incident Plan
Risk
Potential
Assess.
H azards and E ffects M anagem ent
P lanning and Procedures
C orrective A ction
Im plem entation A udit R eview
M onitoring
C orrective A ction & Im provem ent
necessary reforms
8
What is Company’s HSE Management System?
9
HSE Management System
An HSE Management System is a structured set of controls for managing HSE risks in the business; to ensure that HSE objectives are met and to achieve continuous improvement
PATHOLOGICAL
who cares as long as we’re not caught
Characteristics of a Good HSE Culture
Informed - Managers know what is really going on

法语专四历年真命题分类整编

Nom1．La population de la France compte aujourd’hui plus de 60——habitants．(09)A．million d’B．millions d’C．million D．millions2.·Rhinocéros et La Cantatrice chauve sont les——d’Eugène Ionesco．(08)A．chef-d’œuvre B．chefs-d’œuvre C．chef-d’œuvres D．chefs-d’œuvres3．La réunion va commencer dans——．(08)A．une demie-heure B．une heure et demiC．une demie heure D．une demi-heure在名词前无性数变化：une demi-heure在名词后，随有关名词的性数变化，但用单数。

Article1．Je fais souvent des voyages dans le monde，mais je n’ai jamais été——Etats—Unis．(09)A．en B．àl’C．au D．aux2．Une dé1égation française a rendu visite récemment àplusieurs provinces de Chine, dont ___________. (09)A．le Jiangsu B．la Jiangsu C．1es Jiangsu D．Jiangsu3．Ce matin，il a fait——vent terrible．(07)A．du B．le C．un D．de4．Les tomates sont àcombien——kilo? (07)A．1e B．chaque C．un D．par5. J’ai achetéun kilo de pain et des saucisses. _____ pain est tout frais.A. UnB. DuC. DeD. Le6. Avec _____ bonne humeur et _____ grands efforts, on vient àbout des choses les plus difficiles.A. de la, deB. de la, desC. la, deD. la, desAdjectif1．Les faits sont——je vous les ai racontés．(09)A．telles que B．tel que C．tels que D·ce quefait n.m 事实2．Après une journée——，je me couche très tôt le soir．(08)A．épuiséB．épuisée C．épuisant D．épuisante3．La mère ne sait pas comment rendre sa fille——．(08)A。

牛津版八年级英语上Unit6课件

故事讲述
把握故事情节和人物关系，理解故事的主题和意义。
词汇量
评估听力材料中生词的数量和难度，确定是否适合学生水平。
Analysis of Listening Materials
语速
判断听力材料的语速是否适合学生，语速过快会影响理解。
口音
分析听力材料中的口音是否标准，是否包含多种口音。
Listening skills training
REPORT
CATALOG
DATE
ANALYSIS
SUMMAR Y
05
Listening training
Analysis of Listening Materials
新闻报道
重点在于获取关键信息和理解新闻事件的背景。
对话
关注语言交流中的语气、语调和信息传递，理解对话中的隐含意义。
Analysis of Listening Materials
The subject and verb must agree in number. For example, "She sings" is correct, but "They sings" is not.
Verb Tenses
Verbs must be used in the correct tense. For instance, "I will go" is the future tense, while "I went" is the past tense.
Reading skills training
阅读技巧训练
输标02入题
要点二
Character Development

英语写作Lecture6Narration

The plot should be wellstructured, with a clear beginning, middle, and end. It should also have a central conflict that propels the story forward.
Plot development requires skillful handling of events and their impact on the characters. Use techniques like flashbacks, foreshadowing, and parallel storylines to enhance the narrative's complexity and intrigue.
Importance
Well-developed characters and settings are essential for creating empathy and engagement with the reader. They add depth and realism to the narrative.
Good narrative writing skills are essential for effective communication in various contexts, including personal essays, fiction writing, and professional reports.
The course will consist of lectures, workshops, and assignments to provide students with a well-rounded learning experience.

The Respiratory System

LOGO
ห้องสมุดไป่ตู้
The Process of Breathing
Air is moved into and out of the lungs by the process of breathing, technically called ventilation. This consists of a steady cycle of inspiration (inhalation) and expiration (exhalation), separated by a period of rest. The cycle begins when the phrenic nerve(膈神经) stimulates the diaphragm(隔膜) to contract and flatten, thus enlarging the chest cavity.
Thanks
LOGO
Lower Respiratory Passageways and Lungs
The pharynx conducts air into the trachea, a tube reinforced with C-shaped rings of cartilage(软骨) to prevent its collapse. Cilia in the lining of the trachea move impurities up toward the throat, where they can be eliminated by swallowing or by expectoration(咳痰). The larynx is shaped by nine cartilages, the most prominent of which is the thyroid cartilage at the front that forms the “Adam’s apple.” The opening between the vocal cords is the glottis(声门). The small leafshaped cartilage at the top of the larynx is called the epiglottis(会厌). When one swallows, the epiglottis covers the opening of the larynx and helps to prevent food from entering the respiratory tract.

RECSIT1[1].1中英文对照全文

New response evaluation criteria in solid tumours: Revised RECIST guideline (version 1.1)新版实体瘤疗效评价标准：修订的RECIST指南（1.1版本）Abstract摘要Background背景介绍Assessment of the change in tumour burden is an important feature of the clinical evaluation of cancer therapeutics: both tumour shrinkage (objective response) and disease progression are useful endpoints in clinical trials. Since RECIST was published in 2000, many investigators, cooperative groups, industry and government authorities have adopted these criteria in the assessment of treatment outcomes. However, a number of questions and issues have arisen which have led to the development of a revised RECIST guideline (version 1.1). Evidence for changes, summarised in separate papers in this special issue, has come from assessment of a large data warehouse (>6500 patients), simulation studies and literature reviews.临床上评价肿瘤治疗效果最重要的一点就是对肿瘤负荷变化的评估：瘤体皱缩（目标疗效）和病情恶化在临床试验中都是有意义的判断终点。

法国大学M1 controle de gestion课件

Pour des ouvrages d’initiation :
• • •
Amintas A et Guillouzou R (2003), Comptabilité de gestion, Les Fondamentaux Hachette supérieur Doriath B (2004) Comptabilité analytique et gestion prévisionnelle, Fiches Express Dunod. Malo JL et JC Mathé (1998) L’essentiel du contrôle de gestion, Les éditions d’organisation.
19 19 19 19 20 20 20 21 21 21 22 22 24 25 25
MODULE 3 : LA CONCEPTION D'UN SYSTEME DE COMPTABILITE ANALYTIQUE
U1 : Centres d’analyse et répartition des charges fixes La méthode des centres d'analyse Les différents types de centres d'analyse Les unités d'oeuvre et les taux de frais U2 : La répartition des charges indirectes entre les centres Répartitions primaire, secondaire et prestations réciproques U3 : Les méthodes d'évaluation des stocks Les coûts d'achat Le calcul du coût de sortie Attention aux effets U4 : Les coûts de production Les charges directes Les charges indirectes Les différentes modalités de calcul Les en-cours, les rebuts et sous-produits U5 : Le coût de revient Les autres coûts hors production Les coûts de distribution

literary_elements-theme

ization
I don’t play the dozens or believe in standing around with somebody in my face doing a lot of talking. I much rather just knock you down and take my chances even if I’m a little girl with skinny arms and a squeaky voice, which is how I got the name Squeaky.
Example of Theme
“Every man needs to feel allegiance to his native country, whether he always appreciates that country or not.”
From “A Man Without a Country” by Edward Hale pg. 185 in Prentice Hall Literature book
Literary Elements
What parts make up a a story?
/dscorpio/images/literary_elements. ppt
Story Grammar
Setting Characters Plot Climax Theme Resolution Denouement
Parts of a Plot
Inciting incident – event that gives rise
to conflict (opening situation) Development- events that occur as result of central conflict (rising action) Climax- highest point of interest or suspense of story Resolution- when conflict ends Denouement- when characters go back to their life before the conflict

Cooperative-Language-Learning

• Theory of learing • Learners develop communicative competence
in a language by conversing in socially or pedagogically structures situations
Design
• Objectives a) foster cooperation rather than competition b)develop critical thingking skills c)develop communicative competence
corrections. • 8 Students revise their compositions. • 9 Students reread each other's compositions and sign their
names to indicate that each compositions is error--free
key elements of successful group-based learning.
• Positive interdependence • Face-to-face interaction
Positive interdependence
Positive interdependence is successfully structured when group members perceive that they are linked with each other in a
Face-to-face interaction
Students need to do real work together in which they promote each other's success by sharing resources and helping, supporting, encouraging, and applauding each other's efforts to achieve. There are important cognitive activities and interpersonal dynamics that can only occur when students promote each other's learning. This includes orally explaining how to solve problems, teaching

法语政治词汇

Déterminer决定，确定Conduire实施Assurer确保Diriger领导renouveler改选élire选举Examiner检查Conseiller建议voter les lois投票通过法律autoriser授权；准许，批准autoriser la déclaration de guerre授权战争宣言ratifier批准，认可diriger l’action du gouvernement领导政府活动fixer les orientations politiques essentielles确定重大政治方针assurer la coordination de l’action gouvernementale 确保政府工作协调性procédéà着手做，进行être en lice pour为...而争夺être nommépar由...任命La vie politique française est extrêmement complexe et son histoire est parsemée de créations de partis politiques et de scissions.Les partis politiquesétant très nombreux et changeant souvent de nom,il est difficile de s’y retrouver.法国的政治生活是极其复杂的，其历史也穿插着政党的创立和分裂。

因此，法国的政党很多，名称也总变，不容易理清头绪。

法国国家机构法兰西共和国la République françaiseLe président总统Le chef de l’Etat国家主席les institutions françaises法国国家机构le Président de la République共和国总统le chef de l’Etat国家元首Le Premier ministre总理le chef du gouvernement政府头脑la défense nationale国防l’Assemblénationale国民议会les députés国民议会议员le Sénat上议院，参议院les sénateur参议会议员ratifier les accords et traités批准协定和条约référendum n.m全民公决déléguer le pouvoirà授权renouveler v.更换；改革renouvelable adj.可更换的le mandat任期charger委托la norme suprême最高准则vérifier检查；证实，核实la régularité合法性lesélections législatives et sénatoriales国民议会和参议院选举Le parlement议会l’Assemblée nationale国民议会le Conseil des ministres内阁会议Le Conseil constitutionnel立宪委员会Le pouvoir législatif立法权L’organe juridictionnel司法机构Le suffrage选票Le candidat候选人L’élection du président/lesélections présidentielles de la République共和国总统选举le Parlement议会détenir le pouvoir掌权pouvoir législatif立法权l’organe juridictionnel司法机构le Conseil constitutionnel宪法委员会la révision复审élire au suffrage universel direct普选les citoyens公民，国民élire au scrutin majoritaire uninominal单记名投票的多数选举le pouvoir politique/diplomatique/militaire /constitutionnel/judiciaire行政权/外交权/军事权/立法权/司法权民主原则le principe démocratiquele gouvernement政府Le Premier ministre总理le Parlement议会deux assemblées两院Le Sénat参议院L’assemblée nationale众议院le suffrage universel全民普选Le suffrage universel indirect普选间接选举Le suffrage universel direct普选直接选举L’assemblée nationale国民议会Le Conseil constitutionnel制宪委员会Le Conseil d’Etat行政法院Le Conseiléconomique et social经济和社会委员会l’autoritéjudiciaire司法机构les juridictions judiciaires普通法院les juridictions administratives行政法院政体形式la forme de régime共和制la république君主制la monarchie民主主义le nationalismeLa justice司法机构总理Premier ministre共和国总统Président de la République国防部长Ministre de la Défense外交部长Ministre des Affaires Etrangères财政部长Ministre de l’Economie内政部长Ministre de l’Intérieur议会制le parlementarisme议会选举lesélections législatives国民议会l’Assemblée nationale议员le membre du parlement宪法la Constitution政党la majorité多数党，多数派执政党；大多数；成年les Royalistes保皇派les partis politiques en France法国政党participeràla politique参政parti au pouvoir执政党la démocratie民主社会党le Parti socialiste(PS)共产党le Parti communiste(PC)生态主义者（绿党）les Ecologistes(les Verts)保卫法兰西联盟la Rassemblement pour la République(R.P.R)法兰西民主联盟l’Union pour la Démocratie Française(UDF)左翼le gauche右翼le droite保皇派les Royalistes政党les partis politiques保守党parti conservateur社会党le Parti socialiste共产党le Parti communiste绿党les Ecologistes（les Verts）国民阵线le Front National(FN)极左党派l’extrême gauche激进党le parti radical公民运动Le Mouvement des citoyens保卫法兰西运动le Movement pour la France渔猎、自然与传统党Chasse Pêche Nature et Traditions(CPNT)工会le syndicat选民électeur相关表达：arbitrage n.m仲裁，调解，调停；评判initiative n.f创始；创制权，立法创议权l’exécution n.f实施，实行，履行réglementaire adj.规定的；有关规章条例的ordonnance n.f法令，条例，规则Délibérén.m审议，合议consultatif adj.咨询的，商议的，协商的constitutionnel adj.体制上的；符合宪法的，符合立宪政体的àl’issue de...结束后le ballottage无结果的投票une administration行政机构l’action du gouvernement政府的行动la direction领导la politique de la Nation国家政策Être responsable devant le Parlement对议会负责le courant anarchiste无政府主义思潮Le ballottage无结果的投票Le garant保证L’intégritédu territoire领土完整Diplomatique(a.)外交的Membre n.成员promulguer les lois颁布法令les cellules政党支部concouriràl’expression du suffrage促进选举实施le pouvoir权力机关les dirigeants politiques政治领导人la libertéd’opinion言论自由a Constitution de la Ve République第五共和国宪法adhéreràun parti加入党派L’organisation interne du parti政党内部组织7.un texte constitutif宪法条文8.le corpsélectoral选举体系l’exécution des lois法令的实施Régularitén.f合法性Élection n.f选举Constitutionalitén.f合宪性les projets de loi法律草案les textes de loi法律条文Rédaction n.f起草，编写un citoyen公民Conflit冲突Droit n.m权利la libertéindividuelle个人自由议会团体les groupes parlementaires利益集团les groupes de pression资本主义le capitalisme国家权力la puissance de l’Etat民主共和国la république démocratiqueles problèmeséconomiques et sociaux经济和社会问题Gardien n.m保卫者，捍卫者Litige n.m诉讼，争议分裂la scission保护主义le protectionnisme经济转型les transformationséconomiques决裂rompre avec 中国：Lettres de créance：国书。

Thème

汉译法之简明法语教程1.他抓住我的胳膊对我说：“别一个人出去，这太危险了。

”Il m'a pris le bras et m'a dit:«Ne sortez pas seul, c'est trop dangereux.»2.由于没有得到任何答复，她只好重新写了一封信，并直接寄给公司总经理。

N'ayant reçu aucune réponse, elle était obligée d'écrire de nouveau une autre lettre et l'a envoyée directement au directeur général de la société.3.只是在一星期后，他才得知父亲去世的消息。

Ce n'est qu'une semaine plus tard qu'il a appris la nouvelle de la mort de son père.4.由于在北京工作了多年，玛丽回国后很想写一本描述北京人生活的书。

Ayant travaillé longtemps à Beijing, Marie a très envie d'écrire un livre sur la vie des gens de Beijing après le retour dans son pays.5.这儿是两座传统建筑，这一座式木结构的，那一座是石砌的。

Voilà deux grandes maisons traditionnelles: celle-ci est en bois, celle-là est en pierre.6.用这种办法，我们很容易测出海洋的深度。

Theme and Rheme 主位与述位

2）He found that the element in the front of the clause played a special role in the process of the communication and this special role was to serve as a starting point for what a speaker or writer wants to say. 3) Mathesius called the element in the front of the clause “theme” while the rest part of the clause “rheme”. 4) He pointed out that theme generally conveyed given information while rheme new.
(3)Well (连接) but (结构) then (连接) (textuaห้องสมุดไป่ตู้) Ann (称呼) surely (情态) wouldn’t(限定成分) (interpersonal) the best idea (topical theme) //be to join the group?
Besides, it’s worthy of pointing out that 1)Interrogative: (1)Yes—No e.g. Had (finite) + she (subject) (theme) // written about… (2) wh-: wh-words serve as the theme
Conclusion: 1) Now, we get to know, in English, a clause is supposed to consist of two elements. One is theme, the other is rheme.

遥感与地理信息系统方面的好的期刊

遥感与地理信息系统方面的好杂志国内的期刊：1）遥感学报（98年前《环境遥感》杂志，国内比较好的遥感专业杂志，主编是原遥感所所长、现国家科技部部长徐冠华院士，遥感文章比较多，象国内比较牛的遥感理论研究的大牛复旦大学的金亚秋教授和北京师范大学的新当选的院士李小文教授经常有文章发表；基于遥感和GIS资源环境等应用的文章也比较好，主要是中科院地理所和遥感所的；还有就是图像处理的算法研究或新型的遥感方法如雷达干涉测量、高光谱方面的研究，主要由武汉大学测绘遥感信息工程国家重点实验室(L)和中科院遥感所的文章。

（2）测绘学报（侧重测量基础理论的研究，但经常有非常好的综述型的文章，上面的测绘学博士论文摘要是非常好，还有主编陈俊勇院士治学非常严谨，一般的假冒伪劣文章很难找到市场，该刊宁缺勿滥,2001年仍然是季刊,文章少,但很精。

不过该刊刊登的文章比较偏重大地测量（GPS），GIS的文章相比比较少）。

（3）武测学报（2001年改名《武汉大学学报》信息科学版）本杂志是原武汉测绘科技大学学报，主编是中国科学院和中国工程院双院士李德仁教授,很多具有创新性和理论性的测绘研究成果都在该刊发表，展示中国测绘学术研究的最高水平,引导测绘理论研究的方向。

我认为上面的博士论文摘要比较好，真正体现了我国3S技术的研究动向和学术水准。

本刊出版内容包括综述与瞻望、学术论文和研究报告、本领域重大科技新闻等,涉及测绘学研究的主要方面,尤其是摄影测量与遥感、大地测量与地球重力场、工程测量、地图制图、地球动力学、全球定位系统(GPS)、地理信息系统(GIS)、图形图像处理等。

该刊现同时有英文版，名为GEO-SPATIAL INFORMATION SCIENCE，是中文版的精华版，万方科技期刊网上可以下载全文。

（4）中国图象图形学报1996年创刊，由中国图象图形学会、中科院遥感所、中科院计算所共同主办，主编是科技部部长徐冠华院士。

2001年起《中国图象图形学报》分A、B版。

Theme

Sending the final result through to Faculty before all the required will probably just confuse documents have arrived matters. Theme Rheme

The other kind of constituent that is relatively often chosen as Theme in declarative clauses is an Adjunct.
A keen interest in the environment, familiarity with the workings of government and/or the town and country planning system would be a strong advantage.
Have you Hasn’t he Theme finished your meal, sir? changed his name? Rheme

A further type of non-declarative clause is imperative.
Leave Do Let’s Theme
Theme

Introduction Identifying Theme Special thematic structures Theme in clause complexes Multiple Theme
1. Introduction

Some Czech linguists devoted considerable attention to problems of analyzing sentences from a functional point of view. They believe that a sentence contains a point of departure and a goal of discourse. The point of departure is equally present to the speaker and to the hearer —it is the ground on which they meet and is called the THEME. The goal of discourse presents the very information that is to be imparted to the hearer, and is called the RHEME.

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Organoclay (hydrophobic)
BENTONE 有机粘土的增稠防沉机理
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• 高剪切速率 • 极性活化剂 • 特定的添加工艺 • 需要制备预凝胶
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Janvier1996–Journ´e es Francophones des Langages Applicatifs–JFLA96Mar´ıa-Virginia Aponte,Giuseppe Castagna1:CEDRICConservatoire National des Arts et M´e tiers292,rue St.Martin-75003Paris-France.e-mail:2:CNRSDMI-LIENS.´Ecole Normale Sup´e rieure45,Rue d’Ulm-75005Paris-France.e-mail:R´e sum´eLes syst`e mes de modules`a la SML,tout en´e tant tr`e s g´e n´e raux et puissants,n’autorisent qu’une forme limit´e e de r´e utilisation de code etde programmation incr´e mentale.Dans ce travail nous proposons uneextension d’un syst`e me de modules`a la SML qui incorpore surcharge etliaison tardive au langage des modules,et nous montrons les avantages decette extension pour la programmation incr´e mentale,aboutissant ainsi`aun style de programmation similaire`a celui utilis´e dans certains langagesorient´e s objets.1.IntroductionLes syst`e mes de modules`a la SML[Mac85,MTH90]sont tr`e s g´e n´e raux et puissants.Ils permettent un d´e coupage modulaire des programmes et la d´eﬁnition de transformations(appel´e es foncteurs)sur les modules mˆe mes (appel´e s structures).Toutefois,il n’autorisent qu’une forme tr`e s limit´e e de r´e utilisation de code et de programmation incr´e mentale.Plus pr´e cis´e ment, les modules`a la SML ne poss`e dent pas les caract´e ristiques d’h´e ritage et sp´e cialisation de code qui ont fait le succ`e s des langages`a objets.Ce manque est p´e nalisant lorsqu’on veut faire´e voluer un programme.Ainsi,si`a un moment de la vie du programme on d´e cide d’ajouter des nou-velles fonctionnalit´e sen d´e clarant des nouvelles structures qui sp´e cialisent celles d´e j`a existantes,l’utilisation pour ces structures de foncteurs du programme ini-tial(avant sp´e cialisation)reste valide.En revanche il est impossible d’afﬁner le comportement de ces foncteurs par la prise en compte des fonctionnalit´e s ajou-t´e es.Ainsi,les nouvelles structures,soit utilisent les foncteurs d´eﬁnis pour les anciennes,soit en d´eﬁnissent des nouveaux qui leur sont propres et qui n’auront1Nous consid´e rons qu’une fonction surcharg´e e est form´e e par l’ensemble de ses diff´e rents codes associ´e s,et nous appelons branche chaque unit´e de code qui se trouve dans cet ensemble.4Nous ne donnons pas la d´eﬁnition de la signature.6Il faut noter que pour obtenir l’effet d´e sir´e il faut abandonnerle monde purement fonctionnel, car la modiﬁcation de doitˆe tre globale.En fait,mˆe me si la d´e clarationsuit celle de,elle doit n´e anmoins modiﬁer la s´e mantique de utilis´e`a l’int´e rieur de. Dans cette´e tude th´e orique nous n’´e tudions pas cet aspect,mˆe me si dans l’implantation r´e aliste du syst`e me il doitˆe tre inclus.7Les foncteurs`a plusieurs arguments sont obtenus en ajoutant au calcul les produits cart´e siens de signatures.8Plus pr´e cis´e ment,la signature inf´e r´e e est,mais dans cet exemple nous supposons que les signatures de r´e sultat sont closes.11(**)branches additionnelles.Il est inutile de pr´e ciser que,parmi celles-ci,rares sont celles qui pourraient constituer du code int´e ressant:la plupart prendra en compte le cas de structures que le programme n’utilisera jamais.Ainsi, une troisi`e me solution consiste`a demander au programmeur d’indiquer,en les d´e clarant,les signatures qui seront pass´e es aux foncteurs surcharg´e s.Ceci peut ˆe tre obtenu en introduisant des noms pour les signatures,une discipline de sous-typage explicite pour ces noms,et en utilisant pour les signatures de param`e tre des foncteurs surcharg´e s les noms de signatures.Dans l’exemple pr´e c´e dent le programmeur peut d´e cider de“nommer”(d´e clarer)les signatures suivantesde d´e clarer que le nom est un sous-type du nomet de d´eﬁnir le foncteur de la fa¸c on suivanteD´e clarer qu’un nom est un sous-type d’un autre nom est admis seulement si les signatures correspondantes sont dans la mˆe me relation.Contrairement`a ce qui est fait en SML,le sous-typage pour les noms ne co¨ıncide pas avec celui des structures qu’ils nomment,mais ces noms forment une hi´e rarchie a part.Ainsi,le nom n’est pas un sous-type du nom puisque ceci n’a pas´e t´e explicitement d´e clar´e par une construction,ou encore ne ﬁltre pas une structure de signature mais seulement les structures de type ou de type.Ce dernier fait implique que le probl`e me de s´e lection sur ne subsiste plus.En fait,mˆe me si est appliqu´e`a un argument de signature,cet argument estﬁltr´e par mais il n’est pasﬁltr´e par.Ainsi la premi`e re branche est s´e lectionn´e e.Avec le sous-typage explicite pour les noms,。

An Analytical RED Function Design Guaranteeing Stable System Behavior

An Analytical RED Function Design GuaranteeingStable System BehaviorErich Plasser,Thomas ZieglerTelecommunications Research Center ViennaDonaucity Strasse1,1220Vienna,Austriaemail:plasser@ftw.at,ziegler@ftw.atAbstractThis paper introduces the procedure for an analytical derivation of the drop probability function for the Random Early Detection queue management mechanism.The procedure is based on the TCP window system equations and the establishment for a criterion for system stability with methods of control theory.The term stability refers to the oscillation amplitude of the steady state queue size.The outcome is a polynomial function of the queue size,which can be approximated with a power function of the queue size.Besides the goal of achieving low oscillations for the whole load range,this derived function shows yet other advantages.There are no parameters to adjust,which extends the applicability of RED with this derived function to a wide range of load situations.Additionally,the under-utilization at low loads,as often experienced with the original RED function,is avoided automatically.Simulations with FTP-like and web-like TCP trafﬁc show clear evidence that the derived function outperforms the original linear RED function.Index TermsSimulations,Network measurements,Control theoryI.I NTRODUCTIONThe Internet research community regards Active Queue Management(AQM)as an important mechanism to notify trafﬁc sources about the early stages of congestion and thus avoid the need for strong source reactions due to heavy overload[4].The original Random Early Detection(RED)algorithm[5],at which the drop probability increases lin-early between the minimum threshold th min and the maximum threshold th max of the average queue size and at which the drop probability is constrained with a maximum value p max,can be considered to be the most popular AQM mechanism.The average queue size is calculated from the instantaneous queue size by using This work was supported by the Austrian Kplus program and the IST project Moby Dickan EWMA(exponentially weighted moving average)ﬁlter with the weighting factor w q.Since the publica-tion of[5],signiﬁcant research has been devoted to the analysis of the dynamics of RED in interaction with TCP congestion control.Besides[5],several papers like[9],[10],[12],[15],[16]introduce models aimed atﬁnding an appropriate set of the th min,th max,p max,w q parameters.Modiﬁed versions of RED are GRED[6]and ARED[8]. GRED is a fragmented extension for the RED function.Two concatenated linear RED curves with different slopes are established to meet the requirements for low and heavy loads.The problem of parameter setting remains the same as in the original RED.ARED and related forms,such as[16],adapt the maximum drop probability p max according to the load.The increment and decrement of the adaptive p max must be arranged correctly.Both RED versions do not reduce the total number of parameters.The goal of a proper RED adjustment,also aimed by the former mentioned models,is to maintain the average queue size between th min and th max at low oscillations and in turn help to avoid forced drops(i.e. either the instantaneous queue size exceeds the buffer size or the average queue size exceeds th max)and link under-utilization(i.e.the instantaneous queue size decreases to zero).According to the literature,it turned out to be very difﬁcult toﬁnd an appropriate parameter set to adjust RED for general deployment.The weakness of the known models is their orientation on assumed values related to the load,especially such as the round trip time(R),the distribution of R and the number ofﬂows (N).Even if the assumptions on the input parametersﬁt the scenario,the applicability of the original RED mechanism,adjusted accordingly to the models,would be restricted to a small range of the assumed load values only.But in real-life deployments of RED varying and unknown load situations are typical,which basically rules out that one speciﬁc set of parameters found by these models is applicable to all possible scenarios.This restriction is caused by the linearity of the original RED function.In[14]it is illustrated that a high load(which we denote as a high number ofﬂows)requires a disproportionately higher drop probability than a low load to keep the queue size in the same range,a requirement met only by a non-linear drop function.Therefore(in[14]),several approaches to obtain a non-linear drop function for RED are proposed, where,similar to the original RED function,the majority of these approaches were established by heuristics. Such non-linear functions fulﬁll the requirement of the queue size remaining between th min and th max for a much broader load range than the original linear RED function.The drawback of these approaches is thatthe oscillating behavior of the queue size is not expressed as a condition for the establishment of the drop function,thus oscillations occur in many scenarios.Building on these earlierﬁndings,we set out in this paper toﬁnd a procedure for deriving a drop function which meetsﬁrst of all the requirements for the avoidance of heavy oscillations.At the same time,this func-tion is expected to depend solely on system immanent parameters,superseding the impractical adjustment for the th min,th max,p max parameters for different loads.As a consequence this drop function should be applicable independent on the load range.Given our emphasis placed on oscillations,we consider heavy oscillations as a state of instability which is best treated by control theory.Thereby,based on a mathematical description of the TCP window system, we determine that maximum value of the drop probability which keeps the system stable at each considered load.The result is a non-linear continuous polynomial function of the queue size as interpolation from the calculated drop probability values in discrete form.The derived curve is applicable to the whole load range considered in the derivation process.If we compare the performance of the original RED algorithm with a single parameter set in simulations,we see that this function shows signiﬁcant performance improvements in scenarios with constant load as well as with varying/unknown load and round trip time distributions. The rest of the paper is organized as follows:Section II explains the idea behind using control theory for deriving a drop function.In section III the mathematical model used to describe the TCP window system is introduced.The model is linearized and transformed to a transfer function in the Laplace-domain.There-after,the criterion for the stability range of the whole system is explained in general.Section IV outlines how to obtain the drop function based on the TCP window model in six steps.The drop function is then com-pared to a simpler function(a power function)of the queue size for the purpose of easier implementation. Section V is divided into a subsection describing the simulation environment and a subsection presenting the simulation results.The simulations show the response of the derived function and other RED functions to FTP and realistic Web trafﬁc.II.M OTIVATION FOR A C ONTROL T HEORETIC A PPROACHIn general,controller design comprises not just to attain a reasonable behavior in the follow-up control,but especially the investigation of the stability range.The study in[3]shows that the RED algorithm corresponds to a control loop with PI-controller(PI stands for proportional+integral),where the integral part descendsfrom the EWMAﬁlter.The range and the behavior of the desired queue size can be tuned due to the inherent feedback loop of the model of the TCP window system and the corresponding design of the controller.In this paper we concentrate on determining the controller to achieve a stable queue size in steady state for all considered load ranges.For this investigation we assume the system being in the worst case concern-ing oscillation afﬁnity.Therefore we neglect the averaging EWMAﬁlter,i.e.the weighting parameter is assumed to be w q=1.RED can thus be compared to a P-controller as shown in[3].The proportional factor of the P-controller can be considered as the slope K of the original RED function K=p max/(th max−th min).For veriﬁcation of the stability state we recreate this control loop with numerical simulations(Matlab Simulink).The range of stability is calculated as the largest value of K that keeps the system in the stable state.Further on we denote”numerical simulation”as the simulation of the equations of the non-linear mathematical model and”packet simulation”as the simulation of the TCP implementation with the ns-simulator[11].We refer to the deﬁnition of BIBO stability,which means the system responds for every bounded input with a bounded output.All investigations are made in the continuous domain.The deﬁnition at which condition the system is stable or instable is determined by control theory.At stable conditions,the output of the numerical simulation does not oscillate at all.The same conditions in packet simulations give another result.Despite a constant load and a stable state,the queue size is varying with spikes around a mean value,a result well known in common TCP-AQM simulations.We denote such variations as low oscillations.They comply with the smoothest shape of the queue size which is best reached with original RED(pare the best effort adjustments,shown in RED research publications such as [10],[5]and others).There are several reasons for this behavior:One reason is,as we will note later,that our model is inaccurate(e.g.the model considers neither Slow-start nor timeout).Another basic difference is that in packet simulation theﬂows do not start simultaneously from one source,but their starting time is slightly delayed against each other.Additionally,in numerical simulations all values are allowed to be of real format,but in realistic packet simulation only integer values are allowed for the window size and queue size.For instable conditions,the output of the numerical simulation oscillates or tends to inﬁnity,a behavior expected from control theory.The effect of instable conditions in packet simulation is that the amplitudes ofthe oscillations become larger than at stable conditions.To give a measure,large amplitudes in oscillations are in the range of the half buffer size at applications with the linear RED drop function.We denote these large amplitudes as heavy oscillations.By comparing the results in numerical simulations with packet simulations,we conclude that the emer-gence of heavy oscillations can be explained by an instable system state.This observation corroborates the main idea of this paper:The best approach to achieve a drop function which avoids heavy oscillations in packet simulations(and thus in real networks)is to keep the theoretic model in the stability range.III.T HE M ARGINAL S TABILITY OF THE TCP S YSTEMAs the application of control theory requires a mathematical description of the system,we use the model in[1],formulated as stochastic differential equations.This model allows to analytically investigate the behavior of TCPﬂows,which operate with active queue management.Note that these equations describe only a rough model,as they neglect the Slow-start and timeout in the TCP.Simulations show that,given these constraints,the model overestimates the resulting queue size[14].This model,however,is accurate enough for designing a P-controller for RED[3]and shows satisfactory results in the comparison to packet simulations at low loads[14].The TCP system is modeled as follows[2]:dW(t) dt =1R(t)−W(t)2W(t−τ)R(t−τ)p(t−τ)(1)dq(t) dt =NR(t)W(t)−C(2)whereR(t)=q(t)C+T p(3)W .=mean TCP window size of allﬂows[packets]q .=queue length[packets]R .=round trip time[sec]C .=link capacity[packets per sec]T p .=propagation delay[sec]N .=number of TCP sessionsp .=probability of packet lossτ.=time delay at which packet loss occursEquation(1)describes the increase of the window size by one packet per round trip time.Each time apacket loss is detected,the window size is halved.A packet loss happens at time(t−τ)as it is indicated inthe right part of(1).The time shift can be seen roughly as one round trip time.Equation(2)expresses the accumulation of the queue size.Equation(3)describes the round trip time as the sum of the queuing delay and the propagation delay.For stability investigations we use the above-mentioned deﬁnition of BIBO stability.The system is called asymptotically stable if the magnitude of the transfer function is less than one for a phase of-πin the Bode-diagram.This property corresponds to an asymptotically decreasing impulse response.To perform the investigation about stability,the non-linear system in(2),(2),(2)has to be linearized with the Taylor series method at the value of the equilibrium state.The equilibrium state is characterized by the system states,W(t),q(t),which are constant in time.Under the assumption of T p,C,N=const,the equilibrium state is obtained by:˙W=0→p0=2W20(4)˙q=0→W0=C R0N(5)To arrange the transfer function of the system,the equations(1)and(2)have to be linearized and then transformed into the Laplace-domain.Subsequently,the overall transfer function of the linearized TCP system is denoted by:G(s)=qp=−C22Ne−sR0s+10 s+2N20 (6)Before applying the Bode-diagram,to verify BIBO stability we have to include the role of the AQM mechanism as indicated in(1).To provide better insight into the interworking of the transfer function with the AQM mechanism,ﬁgure1depicts the block diagram of the modeled TCP window system.The inherent negative feedback loop can be easily recognized,which makes the system generally applicable to control theory.The queue size inﬂuences the window size and vice versa.The round block represents the controller, which can be denoted as the AQM drop function in this case.The AQM consist of a factor K in analogy to the deﬁnition of the drop probability of the original RED function:p=p max(th max−th min)·q=K·q(7)To the left of the block diagram the optional reference input parameter q ref (for a P-controller)is displayed.The output of a P-controller will tend to reach this reference.A P-controller differs slightly from RED in that for RED the reference q ref =0.Thus,the obtained queue size is the control offset.In this paper,q ref and the P-controller serve as an explanatory purposeonly.W qp W p =K ·qFig.1.Block diagram of the TCP window systemThe Bode-diagram seen in ﬁgure 2shows the magnitude and phase of the overall transfer function.At the critical frequency ωg the phase reaches the value of -π.The condition of the system to be marginally stable is that the magnitude of the transfer function G(s)combined with the factor K (representing AQM)must be one at the critical frequency.As the magnitude of G(s)is determinable for a speciﬁc load,it is easy to calculate the factor K g ,which we denote as the highest factor K to keep the system stable.K g ∗|G (s )|=1(8)Fig.2.Phase and magnitude of a G(s)in the Bode-diagramIV.F ORMATION OF A D ROP F UNCTIONHaving explained the principles underlying the investigation of the stability margin in the previous section,we can move on to derive the drop function in detail.To begin with,we have to ﬁnd the critical frequency ωg and calculate the factor K g from (8)at different loads.As we see in (6),the transfer function is dependent on the load N,thus we expect a different factor K gat each different load.By interpolating the different K g’s,we are thus able to present a new drop function. This drop function represents the highest possible drop probability at each load to avoid instability,i.e.to avoid heavy oscillations.For the derivation the parameters of the equilibrium state are used,denoted as q0,R0,W0,p0.In packet simulations the averaged value of the measured queue size(denoted as average queue size in RED notations) over the simulation time can be used as an approximation of the equilibrium state of the queue size q0.The drop function is derived in six steps:Step1:In theﬁrst step the necessary parameterωg is calculated.The critical frequencyωg can be achieved from the initial condition of the phase of the system without load(N=0).In this situation the queue size q0=0,and because of(3),R0=T p.The equation for the phase in(9)is established by substituting s=jωand applyingϕ=arctan(imaginary partreal part)to each subsystem.The phase of the system is equated to the phase margin set to-π(−180o).Equation(10)is the initial version of(9)to calculateωg.ϕ=−π=−arctan(ωg R20C2N)−arctan(ωg R0)−(ωg R0)(9)π=arctan(ωg R0)+(ωg R0)(10)By transforming(10)and substituting for R0=T p,we obtain:1=(ωg·T p)·tan(ωg·T p)(11)In solving(11)numerically and with T p set to a typical value a service provider will expect,e.g.:T p=0.2 sec,ωg is hence deﬁned as:ωg=0.8603335T p=4.3016675rad−1(12)We see thatωg is only dependent on the selected phase margin as well as on the propagation delay T p which we assume as the average T p of allﬂows.This assumption corresponds to those made for the establishment of the TCP model in[2].Step2:In this step the round trip time R0=R0(N,C,ωg)is determined by varying the load N=0-N max in discrete steps.The range N=0-N max denotes the range of loads for which the system is planned tooperate.The upper limit for N max is bounded in a logical sense by the bandwidth capacity C because of its inﬂuence on the window size.The window size is determined by W=CR/N.At a certain low window size the goodput will be marginal.If this case occurs frequently,the link capacity should be increased by the operator.In this case AQM optimization does not help anymore.Thus,it is useless to shrink the mean window size perﬂow under a plausible minimum value(e.g.W min=3we see as a minimum),or, in other words,it is useless to increase N max to a very high value at a constant C.With regard to higher load situations,we know from experience that in an instable scenario,the queue size tends to become stable again at very high loads(e.g.low oscillations for N=200at C=2500and T p=0.2,the calculated values are R0=0.2723,W=3.4).For this scenario we do not need control theory toﬁnd a stable factor K.Nevertheless, in our derivation of the drop function we run the load also to a high value of N max=400to demonstrate the overall shape.Simplifying(9)results in(13).−tan(ωR0)=ωR20C+2NωR02N−ω2R0C(13)Trying to solve(13)for R0,a closed form could not be found because of the high order of R0,not even by substitution with a rough approximation of tan(ωR0).Thus we have to determine the round trip time R0 numerically.Step3:Now,all necessary values for equation(8)are determined to calculate the maximum value of K g (K g=1|G(jωg)|).Equation(14)is obtained by expanding(6)with s=jωand by calculating the amount of the resulting complex term.K g= 1−ω2g R30C2N 2+ω2g R20 R0C2N+1 2C3R34N2(14)Step4:The steady state queue size corresponding to the load is easily obtained by a slight transcription of (3)into q0=(R0−T p)C and using R0from step2.Step5:So far we have obtained two functions in dependency of the load(q0(N),Kg(N)).For deployment of RED the AQM mechanism calculates the drop probability as a function of the average queue size.Due tothe fact that the load is unknown by the router in advance,establishing a drop function in dependence of the load is pointless.Instead the dependency on the queue size is required,which is the goal of this step5. The factor K g must also meet the requirement of the dependency on the queue size.This can be easily reached by assigning the discrete values of q0(N)and Kg(N),which may also be regarded as vectors,to a discrete vector Kg(q0).In contrast to the original RED function,where K g is constant for all load situations, this derivation denotes K g as a non-linear function of q0.Step6:Finally,we attain the desired function p0(q0)by applying the expression in the block diagram in ﬁgure1,where the AQM mechanism is related to:p0=K g·q0(15)To achieve a continuous function,we now approximate the resulting discrete function p0(q0)with a poly-nomial.The approximations where the continuous function bestﬁts the discrete function is of order three. The value of the drop function reaches the maximum p0=1at N max=400and at q0=266.We see the derived function covers both the whole probability range and the whole range of reasonable values for the load N.Higher loads(which do not have practical sense)correspond in(14)to a K g and thus, using(15),result in a p0≥1,where all packets will be discarded.This proves that our speciﬁed load range N=0-400covers the whole applicable load range for the considered bandwidth-R product.As stated above,because the model fails to completely capture reality,the queue size and window size yielded through the model are overestimated.We see this bias by comparing our experiences in simulations with the original RED to the derived function which features relatively high values for the drop probability, e.g.p0=0.31at N=200,q0=180(where a p0=0.31means about each third packet is to discard).Therefore we intervene in this design procedure by decreasing the amount of the drop function by a diminishing factor of 2.Through investigation with packet simulations on the effects of the polynomial we see great sensitivity against variations of single coefﬁcients(which changes the shape of the drop function deﬁnitively).But the system behaves robust against a decrease of the whole function(decrease of all coefﬁcients at the same scale).Thus the applying of a diminishing factor has no negative effect on causing oscillations.The same effect with another order of magnitude in scaling the drop function would have been obtained by decreasing the phase margin to less than−π(increase of the stability margin).We did not chose this way,because the simpliﬁcations in(9)and the other calculations would have become more difﬁcult.By already including the above diminishing factor the resulting drop function is:p=3.5510−8·q3−4.210−6·q2+5.010−4·q−9.010−3(16)For an easier implementation of(16)in routers we compare the derived function with several simple non-)i,where the exponent linear approaches in[14].These approaches have the form of p=p max·(qmax mini and p max are to be deﬁned.For normalization reasons th max isﬁxed with the largest queue size in the derived drop function,here q0=266for N max=400.th min=0.The maximum drop probability p max isﬁxed as well by the maximum value of the derived drop function,here p max=0.5.Through this comparison,we see that the derived drop function with the parameters C=2500,Tp=0.2is best approximated by a cubic function(i=3)of the queue size.This approximation simpliﬁes implementation in routers because the cubic be can realized by a bit shift(for the square)and a multiplication by the queue size itself.Thus,in contrast to the implementation of the linear function,only one additional multiplication and a bit shift are necessary.In this paper we address the effects of variations of C and T p only in a few words,because they have no effect on the procedure of this derivation and because of space limits.Detailed results will be presented in subsequent research outcomes.It is a fact,that large delay times can steer a system in an instable state easier than small delay times.Therefore we chose T p as relatively high to meet the requirement of the system remaining in the stable state for a large range of occurring T p’s.It is assumed that an ISP operator is able to estimate an average T p for incomingﬂows which can be adjusted onceFor the variation of the bottleneck capacity C it is an important fact that if C is increased/decreased in the same relation as the considered load N max,the minimum window size remains the same as in this example. Accordingly,the derived shape of the drop function will be the same.Note,that also the scale of the queue size will change with the same ratio as C and N max.The approximation curve remains proportional to the cubic of the queue size.At the end,the link capacity does not change in a general deployment,thus the drop curve has to be calculated once.Inﬁgure3we see the resulting derived drop function compared with the normalized cubic RED function. The derived drop function guarantees the prevention of heavy oscillations for all considered loads,and additionally,as the factor Kg is determined to be maximal(and so is p0),the function pursuits keeping theFig.3.Derived drop function in comparison with the cubic functionqueue size,and hence the delay low.Arguments that for a low queue size there is a high possibility of under-utilization can be responded by considering the shape of the curve at this queue size inﬁgure3.On one hand,at low load the function features aﬂat slope(small drop probability),meeting exactly a requirement for avoiding under-utilization as proposed in[14].On the other hand,a high load forces a disproportional high drop probability to keep the queue size in a range compared to low load.We already mentioned this requirement in section I.Another advantage of the derived drop function is its applicability for the whole load range considered in the derivation,which does not exclude the theoretical limit of inﬁnite load.As we have seen by applying the procedure in section IV with increasingﬂows N,at some special theoretically maximum value of N the maximum value of the drop probabilities of one will be reached.Furthermore,all higher loads will be treated with the same probability of one.Therefore we can state,the drop function is applicable to all load states-no parameters are to adjust at all.The diminishing factor is the only factor which the user can tune. Note that with a lower diminishing factor the results for under-utilization will become higher as depicted in the simulationﬁgures in the next chapter.V.V ERIFICATION WITH FTP AND W EB T RAFFIC S IMULATIONSA.EnvironmentFor packet simulations we use the ns-2simulator[11]conﬁgured with the topology depicted inﬁgure4. With this topology FTP and web trafﬁc are simulated.For FTP trafﬁc the access hosts(h1-h4)on the left side act as sources,the access hosts(h5-h8)on the right side act as sinks.For simulations with web trafﬁc a realistic web model is used as referenced in [17].The left hosts (h1-h4)serve as clients requesting web pages and objects in the web page.The right hosts (h5-h8)serve as server delivering the requested data.The access links to the routers each have a capacity of 100Mbps.The propagation delay to their connected router r1or r2is distributed with a mean of 10ms and a variation of 5ms at maximum.The two routers r1,r2are connected to the bottleneck link where RED AQM is performed.The bottleneck link capacity is C=10Mbps (2500packets/sec)and the propagation delay on this link is T p =100ms in one direction.The thresholds at which the drop function starts and ends to work are:th min =0packets,th max =266packets.The buffer size is B=300packets.The weighting parameter is set to w q =0.1,as recommended in [13].10Mbps100msh3h4h1r1100Mb p s ,8.3ms100M bp s , 11.6m s100M b p s , 15m s h7h8h5100M bp s , 11.6m s100M b ps , 15m s100Mb p s , 8.3m s 100Mb ps , 5m sr2100M b p s ,5msh6h2Fig.4.Simulation topologyThe RED algorithm operates in packet mode.TCP data senders are of type New-Reno.The TCP packet sizes are uniformly distributed with a mean of 500bytes and a variance of 50bytes.The simulations were done with two types of trafﬁc:everlasting FTP-like TCP ﬂows and web trafﬁc in order to accurately model the real Internet trafﬁc characteristics.Web trafﬁc is created according to SURGE,which is a state-of-the-art model for web trafﬁer think times are Pareto distributed,inter-object times are Weibull distributed,the number of objects per web page is Pareto distributed,the ﬁle sizes consist of a mixed Log-Normal/Pareto distribution.For further details of this model we refer to [17].Simulations are run for 2000seconds simulation time in the case of FTP trafﬁc and 5000seconds in the case of web trafﬁc.We have concisely veriﬁed that conﬁdence intervals are small for all scenarios.The load is varied from N min =20,50,100,200,300to N max =400FTP ﬂows.For web simulations the number of sessions simulated is 20,100,300,500,1000.B.Simulation ResultsTo compare the performance of different drop functions we chose the original linear RED function to show the advantage of a non-linear function against the linear function.We took two versions of the linear function。

ReadyNAS 2100 NETGEAR 安装指南说明书

ReadyNAS™ 2100 NETGEAR®Veuillez suivre les instructions ci-dessous pour installer votre ReadyNAS™ 2100 NETGEAR®. Consultez ensuite le Manuel de l'utilisateur du ReadyNAS 2100 pour obtenir des instructions sur la configuration et le fonctionnement de votre appareil.Un lien vers le Manuel de l'utilisateur du ReadyNAS 2100 se trouve sur le CD et dans la section Support du site Web NETGEAR à l'adresse gear.fr/support/. Ces instructions sont rédigées pour une configuration par défaut en mode X-RAID2.Durée approximative de l'installation : 20 minutes.Remarque: une unité sans disque nécessite l'installation des disques et l'initialisation du RAID avant de continuer. Consultez la page gear.fr/support/ pour obtenir une liste des disques pris en charge. Reportez-vous au Manuel de l'utilisateur du ReadyNAS 2100 pour obtenir des instructions sur l'installation des disques et la configuration RAID.Configuration de baseSuivez les étapes ci-dessous pour configurer rapidement votre ReadyNAS™ 2100 NETGEAR®.Installation de l'utilitaire RAIDarInstallez l'utilitaire RAIDar à partir du CD fourni avec le produit. V ous trouverez, sur le CD d'installation, l'utilitaire RAIDar pour Windows, MAC et Linux. Connexion de l'unitéLors de la configuration initiale, connectez le port Ethernet LAN1 du ReadyNAS à votre réseau et allumez-le. Le démarrage nécessite environ une minute. Par défaut, l'adresse IP est obtenue via DHCP.Remarque: A l’issue de la procédure de démarrage, l’adresse IP attribuée à l’unités’affichera dans la zone d’état.Connexion à l'unité1. Exécutez l'utilitaire RAIDar afin qu'il détecte l'unité.Conseil: dans votre serveur DHCP, réservez l'adresse IP attribuée à votreReadyNAS 2100 afin qu'il utilise toujours cette même adresse. Ainsi, lesunités mappées fonctionnent de manière homogène sur n'importe quel systèmed'exploitation. 2. Cliquez sur Setup (Configuration) pour ouvrir, à partir de votrenavigateur, une session ReadyNAS™ 2100 FrontView avec votreunité. L'écran de connexion s'ouvre. Le nom d'utilisateur et le motde passe par défaut sont respectivement admin et netgear1.La page d'accueil de l'utilitaire de configuration FrontViews'affiche.Utilisation de l'assistant d'installation pourconfigurer les paramètres de baseL'assistant d'installation vous explique comment configurer le partage de fichiers de base.Reportez-vous au Manuel de l'utilisateur du ReadyNAS 2100 pour obtenir des instructionsconcernant la configuration d'options telles que la sauvegarde, les serveurs de contenumultimédia, les imprimantes, le VLAN ou les comptes d'utilisateur et les quotas.Remarque: si vous souhaitez désactiver l'assistant d'installation, assurez-vous deconfigurer les adresses électroniques d'alerte, de modifier le mot de passe admin etd'indiquer une question pour la récupération du mot de passe.1. Par défaut, l'assistant d'installation estactivé lorsqu'il est connecté à l'unité.Cliquez surNext (Suivant) pourutiliser l'assistant d'installation.2. Sous l'onglet Clock (Horloge), vouspouvez modifier ou accepter le fuseauhoraire, l'heure et les options NTPparamétrées par défaut. Cliquez surNext (Suivant) pour continuer.3. Sous l'onglet Alerts (Alertes),indiquez au moins une adresseélectronique pour recevoir lesalertes du système. Cliquez surNext (Suivant) pour continuer.4. Sous l'onglet Ethernet 1, acceptez oumodifiez les paramètres de l'adresseIP.Cliquez sur Next (Suivant) pourcontinuer.5. Sous l'onglet Global Settings(Paramètres globaux), vous avez lapossibilité de modifier le nom d'hôtede l'unité. Par ailleurs, si vous optezpour une configuration IP statique,vous devrez configurer la passerelleet les paramètres DNS (vous n'avezpas besoin de modifier cesparamètres si vous utilisez l'unité dans sa configuration DHCP par défaut). Cliquezsur Next (Suivant) pour continuer.6. Sous l'onglet Admin Password(Mot de passe admin), modifiez lemot de passe du système etindiquez une question derécupération, sa réponse et uneadresse électronique. Veuilleznoter ces modifications. Cliquezsur Next (Suivant) pour continuer.7. Sous l'onglet Security Mode(Mode de sécurité), sélectionnezl'option User (Utilisateur) pardéfaut qui permet de contrôlerl'accès aux partages en fonctiondes comptes clients ou de groupe. FrontView essaiera de détecter le premier nom degroupe de travail présent sur le réseau. Dans le cas contraire, « VOLUME » sera lenom par défaut du groupe de travail. Indiquez le nom du groupe de travail auquelvotre unité doit se connecter. Reportez-vous au Manuel de l'utilisateur duReadyNAS 2100 pour obtenir des instructions d'installation ACS. Cliquezsur Next (Suivant) pour continuer.8. Sur la page Accounts (Comptes), cliquez sur Add User (Ajouter un utilisateur).Ajoutez un nouvel utilisateur et un mot de passe d'utilisateur. Cliquez sur Next(Suivant) pour terminer la procédure d'installation avec l'assistant. Reportez-vous auManuel de l'utilisateur du ReadyNAS 2100 pour obtenir des instructions complètessur la configuration de comptes.La configuration de base est à présent terminée. Enfin, vérifiez que vous pouvez accéderaux partages de votre ReadyNAS.Accès à votre stockage partagéSuivez les étapes ci-dessous pour accéder aux partages de votre ReadyNAS.V ous remarquerez que ces protocoles de partage de fichiers sont activés par défaut : CIFS,AFP (annoncé sur Bonjour et ATP), HTTP/S. FTP, NFS et Rsync sont pris en charge maisne sont pas activés par défaut.Reportez-vous au Guide de l'utilisateur du ReadyNAS 2100 pour obtenir des instructionsconcernant l'accès aux partages à partir de système d'exploitation Linux ou Unix, lemappage de lecteurs et d'autres options de partage de fichiers, notamment la prise encharge d'un seul langage pour les noms de fichiers tels que ceux qui utilisent descaractères Unicode ou idéographiques.Mars 2009Ce symbole a été apposé conformément à la directive européenne 2002/96 sur la mise au rebut des équipements électriques et électroniques (directive WEEE - Waste Electrical and ElectronicEquipment). En cas de mise au rebut de ce produit dans un État membre de l'Union européenne, il doit être traité et recyclé conformément à cette directive.© 2008, 2009 par NETGEAR, Inc. Tous droits réservés. NETGEAR et le logo NETGEAR sont des marques déposées de NETGEAR, Inc. aux États-Unis et/ou dans d'autres pays. Les autres marques ou noms de produits sont des marques commerciales ou des marques déposées de leurs détenteurs respectifs. Ces informations sont susceptibles d'être modifiées sans préavis.Accès aux partages à partir d'un ordinateur exploitant Windows1. Pour afficher une liste de partages sous Windows, cliquez sur Parcourir dans RAIDarou bien saisissez \\<adresse_ip> ou \\<nom_d'hôte> dans la barre d'adresse de Windows Explorer.2. Lorsque vous y serez invité, saisissez le nom d'utilisateur et le motde passe pour vous connecter au ReadyNAS.Windows Explorer affichera le contenu de partage du ReadyNAS.Accès aux partages depuis MAC OS X1. Pour accéder au même partage sur AFP avec OS X, ouvrez Finder et recherchez unnom d'hôte ReadyNAS dans la section SHARED (PARTAGE).2. Cliquez sur le nom d'hôte pour afficher les partages.\\Nv6-07-15-F4\\Nv6-07-15-F4Astuces et précautions d'emploiPour un fonctionnement optimal de votre unité, suivez ces directives.Mise sous/hors tensionLa mise sous tension de l'unité peut nécessiter environ une minute. Pour mettre l'unité hors tension, appuyez deux fois sur le bouton d'alimentation situé à l'avant de l'unité. Cette méthode permet une mise hors tension en bonne et due forme. Pour d'autres optionsconcernant la mise hors tension et le ralentissement de la rotation du disque, reportez-vous au Guide de l'utilisateur du ReadyNAS 2100.VentilationQuatre disques haute vitesse et de grande capacité produisent une quantité de chaleur considérable. Veillez à ne jamais obstruer la grille de ventilation.Utilisation d'une alimentation sans interruption (ASI)Une alimentation sans interruption (ASI) protège votre unité et permet une mise hors tension automatique et traditionnelle en cas de coupure de courant. Pour en savoir plus sur l'utilisation d'une alimentation sans interruption, consultez le Manuel de l'utilisateur du ReadyNAS 2100.Affichage d'informations d'état dans FrontViewLa barre située en bas de l'utilitaire de configuration FrontView affiche des voyants d'état à code de couleurs permettant d'en savoir plus sur la connexion à des groupes de travail, les disques, le ventilateur, la température et l'ASI (le cas échéant).Double cliquez sur le voyant d'état pour afficher les détails correspondant à l'élément.Redondance et extensionUn périphérique à disque unique ne possède pas de redondance et n'est pas à l'abri d'une défaillance. En revanche, si vous avez besoin de redondance, ajoutez un nouveau disque à chaud d'une capacité au moins équivalente à celle du premier (il est inutile d'éteindre votre unité). Selon la taille du disque, votre volume de données deviendra pleinement redondant dans les minutes qui suivront. Le processus se produit en arrière-plan. Ainsi, l'accès à l'unité n'est pas interrompu. Par ailleurs, vous pouvez ajouter, en fonction de l'évolutionde vos besoins en stockage, plus de disques à chaud pour une extension horizontale ouremplacer vos disques actuels par d'autres dotés d'une plus grande capacité. X-RAID2 augmente automatiquement votre stockage de manière incrémentielle et verticale. Grâce à X-RAID2, vous vous affranchissez du reformatage de vos disques et d'une réorganisation rébarbative de vos données.Assistance techniqueNotez le numéro de série inscrit sur l'étiquette située sous votre produit.Il vous sera nécessaire pour enregistrer votre produit à l'adresse http://www.reseaufacile.fr/enregistrement .V ous devez enregistrer votre produit sur notre site Web ou par téléphone avant de pouvoir utiliser notre service d'assistance téléphonique. Les numéros de téléphone des centres d'assistance clientèle régionaux figurent sur la carte « Warranty and Support Information », fournie avec votre produit.Pour obtenir des mises à jour de produits et consulter le support Web, rendez-vous sur gear.fr/support .。

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Everyone here works directly with our clients, so if a client has a question that relates to the design they’ll speak to the designer that worked on it. It’s fun, as it should be. We spend so much of our life working that we’d best enjoy it.
Everyone that works here has a desire to create amazing user experiences. Being great at what you do is the cost of entry at Neue Swiss.
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Authoritatively cultivate out-of-the-box processes after emerging products. Efficiently fabricate front-end results after ubiquitous methodologies.

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I R I S A CAMPUS UNIVERSITAIRE DE BEAULIEU - 35042 RENNES CEDEX - FRANCEI S S N 1166-8687I NSTITUT DE R ECHERCHE EN I NFORMA TIQUE ET S YST`EMES A L´EA TOIRESCampus de Beaulieu–35042Rennes Cedex–FranceT´el.:(33)029*******–Fax:(33)029*******http://www.irisa.fr Providing Reliability on Demand in Distributed VoDServersM.Billot*Th`e me1—R´e seaux et syst`e mesProjet SolidorPublication interne n˚1139—Octobre1997—29pages Abstract:Video on Demand(V oD)services are characterized by quality of ser-vice requirements which depend on:the quality of video and sound transmitted to the client,the respect of time constraints associated to video and audio data and the reliability and accessibility of the service.Much work has been done in order to provide system support aimed at meeting reliability requirements in distributed V oD servers.However,existing proposals focus on the treatment of failures of the network and disks,and do not integrate the consequence of CPU failures.To deal with this issue,we propose a resource reservation model that integrates reliability requirements.In this paper,we customize the resource manager of a distributed V oD server in order to take advantage of the large set of resources(disks and CPUs) to enhance the server’s reliability.The proposed resource manager implements a load balancing strategy which provides reliability on demand and guarantees the server’s accessibility.This paper details the design and implementation of the cor-responding algorithm,and presents results showing that our load balancing strategy reduces the cost of reliability in terms of resource consumption.Key-words:reliability,quality of service,distributed system,video on demand, resource reservation,fault-tolerance(R´e sum´e:tsvp) *IRISA–INRIA,Projet Solidor.e-mail:Manuel.Billot@irisa.frCentre National de la Recherche Scientiﬁque Institut National de Recherche en Informatique (UPRESSA6074)Universit´e de Rennes1–Insa de Rennes et en Automatique–unit´e de recherche de RennesFournir laﬁabilit´e`a la demande dans les serveurs deVoD distribu´e sR´e sum´e:Les services de vid´e o`a la demande(V oD ou Video on Demand)sont caract´e ris´e s par des besoins en terme de:qualit´e de la vid´e o et du son transmis au client,respect des contraintes temporelles associ´e es aux donn´e es audio et vid´e o,ﬁabilit´e et accessibilit´e du service.Beaucoup de travaux apparent´e s ont eu pour objet de fournir un syst`e me permettant de r´e pondre aux besoins deﬁabilit´e des ser-veurs de V oD distribu´e s.Pourtant,ces propositions se concentrent essentiellement sur le traitement des d´e faillances des r´e seaux ou des disques et ne consid`e rent pas la possibilit´e de d´e faillance des CPUs.Pour r´e pondre`a ce probl`e me,nous propo-sons un mod`e le de r´e servation de ressource qui int`e gre les besoins deﬁabilit´e.Dans ce papier,nous adaptons le gestionnaire de ressources d’un serveur de V oD distri-bu´e pour proﬁter du grand nombre de ressources(CPUs et disques)pour am´e liorer laﬁabilit´e du serveur.Le gestionnaire de ressources propos´e met enœuvre une technique de r´e partition de charge qui permet de concilier les besoins deﬁabilit´e et la garantie de l’accessibilit´e du serveur.Dans ce document,nous d´e taillons la conception et la mise enœuvre de l’algorithme correspondant et nous pr´e sentons les r´e sultats montrant que notre technique de r´e partition de charge r´e duit le coˆu t de laﬁabilit´e en terme d’utilisation de ressources.Mots cl´e s:ﬁabilit´e,qualit´e de service,syst`e me distribu´e,vid´e o`a la demande, r´e servation de ressource,tol´e rance aux fautesProviding Reliability on Demand in Distributed VoD Servers34M.BillotProviding Reliability on Demand in Distributed VoD Servers56M.BillotProviding Reliability on Demand in Distributed VoD Servers78M.Billot1Section4.2describes how this reliability criterion can be evaluated.Irisa(1) PI n˚1139(2) The undertaken approach for detecting the primary failure may introduce erroneous recovery which can lead the service to either not display a one-second sequence or,The resource failed before.We get:The resource is failing and no other resource failed before:We get:3The data rate isﬁxed to32ko/s in order to provide25images per secondIrisa.The reliability cost of our method is given in the graph ofﬁgure7.This graphcostof video sequenceFigure7:Reliability cost.demonstrates the advantages of shared reservation:it provides a wide range of re-liabilities leading to different costs.Our approach offers intermediate solutions between usual extreme solutions that are the absence of replication and replication without shared reservation.For similar reliabilities,the cost obtained with six co-pies is better than the one obtained with two copies.This means that the algorithm takes advantage of shared reservation and therefore increases the accessibility of the server while providing reliability on demand.PI n˚1139.The reliability of the above RAID noted()depends on the reliability of a disk noted().The RAID being able to accommodate a single failure,its reliability is.Let us deﬁne,the reliability cost of various RAID architectures are presented inIrisaProviding Reliability on Demand in Distributed VoD Servers29。