Syntactic clustering of the web

hierarchical clustering结果解读-回复Hierarchical clustering, also known as hierarchical cluster analysis, is a widely used technique in data mining and exploratory data analysis. It aims to organize data objects into a hierarchy of clusters based on their similarity or dissimilarity measures. In this article, we will discuss how to interpret the results of hierarchical clustering and provide step-by-step guidance for understanding the analysis.1. Understanding the hierarchical clustering algorithm: Hierarchical clustering can be performed using two main approaches: agglomerative and divisive. Agglomerative clustering starts with each data point as an individual cluster and then merges the most similar clusters iteratively until one cluster remains. Divisive clustering, on the other hand, begins with all data points in a single cluster and then splits the cluster into smaller clusters based on dissimilarity measures.2. Interpreting dendrograms:One of the key outputs of hierarchical clustering is a dendrogram, which is a tree-like structure depicting the clustering process. The x-axis of the dendrogram represents the data objects, and they-axis represents the dissimilarity between clusters or data points.By analyzing the dendrogram, one can gain insights into the hierarchical relationships between data points and clusters.3. Determining the number of clusters:One of the challenges in hierarchical clustering is deciding on the optimal number of clusters to use. This decision can be made by inspecting the dendrogram and identifying the distinct branches or clusters. The height at which the dendrogram is cut determines the number of clusters. In general, a cut at a higher height results in fewer clusters, while a cut at a lower height produces more clusters.4. Understanding cluster assignments:Once the number of clusters is determined, each data point is assigned to a specific cluster. These assignments are based on the hierarchical relationships identified in the dendrogram. Each cluster represents a group of data points that are similar to each other and dissimilar to data points in other clusters. Understanding the characteristics of each cluster can provide valuable insights into the underlying patterns in the data.5. Analyzing cluster characteristics:After the data points are assigned to clusters, it is essential toanalyze the characteristics of each cluster. This can be done by examining the mean, median, or mode values of variables within each cluster. Additionally, statistical tests or data visualization techniques can be used to compare cluster characteristics across different clusters. An in-depth analysis of cluster characteristics can help identify meaningful patterns or relationships within the data.6. Evaluating cluster quality:Assessing the quality of the clusters obtained from hierarchical clustering is crucial to determine the reliability of the results. Several techniques can be employed to evaluate cluster quality, such as silhouette analysis, internal validation metrics (e.g., the Dunn index or Calinski-Harabasz index), or external validation metrics (e.g., the Fowlkes-Mallows index or Rand index). These evaluation measures help determine the consistency and separability of the clusters.7. Iterating and refining the analysis:Hierarchical clustering is an iterative process that may require refining and optimizing to achieve meaningful results. This can involve adjusting distance metrics, linkage criteria, or data preprocessing techniques to improve cluster quality. It is importantto fine-tune the analysis iteratively to obtain the most accurate and informative clustering results.In conclusion, hierarchical clustering is a powerful analysis technique that can reveal valuable insights from complex datasets. By interpreting the dendrogram, determining the number of clusters, understanding cluster assignments, analyzing cluster characteristics, evaluating cluster quality, and iteratively refining the analysis, researchers can gain a deeper understanding of the underlying patterns and structures in the data. This information can be used for various applications in fields such as marketing segmentation, customer behavior analysis, genomics, and social network analysis.。

English Chinese list of wordnet-related terms 3.3.1A 各类词网|B 词义关系|C 词类及其他术语|D 语意属性A 各类词网Bilingual Wordnet (Bi-WN) 双语词网Chinese Wordnet (CWN) 汉语词网EuroWordNet (EWN) 欧语词网WordNet (WN) 词网（特指Princeton WN）B 词义关系antonym 【反义词】antonymy反义关系autoantonymy反义多义（关系）autohyponymy下位多义（关系）hypernym【上位词】泛称词hypernymy上位关系hyponym 【下位词】特指词hyponymy 下位关系holonym整体词holonymy整体－部份关系meronym部份词meronymy部份－整体关系metonym 转指词metonymy 转指关系near-synonym 近义词near-synonymy 近义关系polysemy 【多义性】synonym 【同义词】synonymy同义关系taxonomy 分类架构troponym方式词troponymy方式关系C 词类及其他术语adjective 【形容词】adverb 【副词】agreement 【对谐】，一致性algorithm 【算法／算法】ambiguity 歧义associations 关联attributes 【属性】auxiliary verbs 助动词basic-level categories 基层范畴，底层范畴buffers 【缓冲区】case propagation 格位相沿，格位沿袭categories 范畴causative 【使动】cause relation 因果关系cause 原因change-of-state verbs 易态动词collocations 【连用语】common nouns 普通名词component-object meronyms组成部份（关系）compounds 复合词concepts概念conceptual semantic relation 概念语意关系concordances【关键词（前后文）排序】，汇编connectivity 连结性constraints 【限制】context 【语境】，上下文co-occurrence 共现count nouns 可数名词cousins in hyponyms 特指亲属，下位亲属data mining 数据挖掘database 数据库decomposition 分解derived adverbs 衍生副词descriptive adjectives 描述性形容词determiners 限定符dictionaries 辞典disambiguation 排歧distance in lexical trees 词汇树间距domain-specific knowledge 特定领域知识，领域知识encyclopedic knowledge 百科全书知识，通识知识entail 蕴涵entailment 【蕴涵】entry 词条euphemisms 委婉用法exceptions 例外factive叙实familiarity index 熟悉度索引frames 【框架】frequency 频率functional hyponymies功能性上位词functions 功能gadability具层级性gender 性别glosses 注释gradable 可分级的gradation/gradability/gradable 层级head synsets同义词集主语hierarchies 层级homographs 同形异义词，同形词idioms 【成语】intension 内涵Inter-Lingual-Index (ILI) 中介索引intransitive verbs 不及物动词IS-A relations 【IS-A关系】lexical chains 词链Lexical Conceptual Structure (LCS) 【词汇概念结构】lexical knowledge link (LKL) 词汇知识链接lexical relation 词汇关系lexical subordination 词汇从属lexical superordination词汇上属lexical tree (LexTree) 词树lexicon 【词汇库】词汇malapropism 近音误用；近音误用词markedness有标mass nouns 物质名词meaning extension 意义延伸meaning facet(s) 义面meaning 意义metaphor 【隐喻】metaphoric extension 隐喻延伸modeling 模型制作；模制models 模型morphology 构词法nano-hyponymynominalization 【名物化】noun 【名词】ontology 本体架构parsing 【剖析】；分析；解析participial adjectives 分词形容词part-of-speech (POS) 【词类】phrases 【词组】proper nouns 专有名词quantifiers 数量值questions and answers 问答repetition 重复resultative结果satellitesynsetsschema analysis 基架分析schema 基架semantic concordance (database) 语意汇编（数据库）semantic distance 语意距离semantic domain 语意范畴semantic field 【语意场】semantic opposition 对立语意semantic tags 语意标记sense disambiguation 词义厘清sense 词义subordination 【从属】stative verbs 状态/况动词synset同义词集syntactic classes 语法词类tags 【标记】thesaurus 【同义词辞典】topical clustering 主题丛聚topic 话题topic continuity话题延续training 训练；练习transitive verbs 及物动词unaccusativity非宾格；宾主格unergative verbs 唯（被）动动词；作动词verb 【动词】verb alternations 动词句型替换verbs of action 行动动词weights 加权word 【词】word association 词汇关联word distance 词义距离wordnet词网D 语意属性go topaccount 簿册addictive 嗜好物adverbial 副状affairs 事务age 年龄agent 施事agreement 条约aircraft 飞行器animal 禽兽animate 生物appearance 外观area 面积army 军队artifact 人工物aspiration 意愿attire 装束attitude 态度attribute 属性bacteria 微生物beast 走兽beneficiary 受益者bill 票据bird 禽boundary 界限building 建筑物cause 原因celestial 天体character 文字chemical 化学物classifier 单位词clothing 衣物cloud 云coagent合作施事color 颜色comment 评论community 团体component 部件computer 计算机concentration 浓度concession 让步condition 条件conjunction 并列connective 关联词content 内容contrast 对比countenance 表情crop 庄稼dampness 湿度degree 程度demeanor 风度density 密度depth 深度descriptive 描写direction 方向disease 疾病distance 距离divergence 分歧document 文书drinks 饮品duration 时段duty 责任earth 大地edible 食物electricity 电emotion 情感emphasis 强调entity 实体event 事件expenditure 费用experience 感受experiencer 经验者facilities 设施fact 事实feeling 情绪fineness 粗细fire 火fish 鱼flora 花草food 食品form 形状frequency 频率fruit 水果fund 资金furniture 家具gas 气体hardness 硬度height 高度house 房屋human 人humanized 拟人ice 冰implement 器具inanimate 无生物information 信息insect 昆虫institution 机构instrument 工具kind 类型knowledge 知识land 陆地language 语言law 律法length 长度letter 信件lights 光liquid 液体livestock 牲畜location 位置location 处所machine 机器manner 方式mark 标志material 材料means 手段measurement 量度medicine 药物mental 精神metal 金属method 方法modality 语气modifier 描述money 货币music 音乐natural 天然物negation 否定news 新闻occupation 职位organization 组织paper 纸张part 部分particle 助词partof部分patient 受事phenomena 现象place 地方plans 规划plant 植物possession 领属possessor 领有者posture 姿势price 价格problem 问题process 过程property 属性publications 书刊purpose 目的quality 质量quantity 数量range 幅度readings 读物，读数reason 道理regulation 规则relationship 关系restrictive 限定result 结果rights 权利room 房间scene 景象scope 范围sequence 次序sex 性别shape 物形ship 船situation 状况size 尺寸sky 空域slope 坡度software 软件sound 声音source 来源space 空间speed 速度state 状态static 静态stationery 文具stone 石style 风格supplement 递进symbol 符号system 系统target 目标taste 味道temperature 温度tense 时态，时式text 语文，文本thickness 厚度thing 万物thinking 思想thought 念头thunder 雷tightness 松紧time 时间tool 用具transition 转折treasure 珍宝tree 树unit 单位vegetable 蔬菜vehicle 交通工具volition 意向，意志（力）volume 容积water 水waters 水域wealth 财富weapon 武器weather 气象weight 重量whole 整体width 宽度wind 风wood 木。

1.1 在多道程序和分时环境中，多个用户同时共享一个系统，这类状况致使多种安全问题。

a. 列出此类的问题 b.在一个分机遇器中，可否保证像在专用机器上相同的安全度？并解说之。

Answer: a.盗取或许复制某用户的程序或数据；没有合理的估算来使用资源（ CPU，内存，磁盘空间，外头设施）ｂ．应当不可以，因为人类设计的任何保护体制都会不可以防止的被此外的人所破译，并且很自信的以为程序自己的实现是正确的选项是一件困难的事。

1.2 资源的利用问题在各种各种的操作系统中出现。

试例举在以下的环境中哪一种资源一定被严格的管理。

（ａ）大型电脑或迷你电脑系统（ｂ）与服务器相联的工作站（ｃ）手持电脑Answer: （ａ）大型电脑或迷你电脑系统：内存和CPU 资源，外存，网络带宽（ｂ）与服务器相联的工作站：内存和CPU 资源（ｃ）手持电脑：功率耗费，内存资源1.3 在什么状况下一个用户使用一个分时系统比使用一台个人计算机或单用户工作站更好？Answer: 当此外使用分时系统的用户较少时，任务十分巨大，硬件速度很快，分时系统存心义。

充足利用该系统能够对用户的问题产生影响。

比起个人电脑，问题能够被更快的解决。

还有一种可能发生的状况是在同一时间有很多此外的用户在同一时间使用资源。

看作业足够小，且能在个人计算机上合理的运转时，以及当个人计算机的性能能够充足的运转程序来达到用户的满意时，个人计算机是最好的，。

1.4 在下边举出的三个功能中，哪个功能在以下两种环境下， (a)手持装置 (b)及时系统需要操作系统的支持？ (a)批办理程序 (b) 虚构储存器 (c)分时Answer: 对于及时系统来说，操作系统需要以一种公正的方式支持虚构储存器和分时系统。

对于手持系统，操作系统需要供应虚构储存器，可是不需要供应分时系统。

批办理程序在两种环境中都是非必需的。

1.5 描绘对称多办理（ＳＭＰ）和非对称多办理之间的差别。

多办理系统的三个长处和一个弊端？Answer: ＳＭＰ意味着所以办理器都平等，并且I/O 能够在任何办理器上运转。

I.J. Information Technology and Computer Science, 2013, 11, 42-53Published Online October 2013 in MECS (/)DOI: 10.5815/ijitcs.2013.11.05A Proposed Model for Web Proxy CachingTechniques to Improve Computer NetworksPerformanceNashaat el-KhameesyProf. and Head of Computers & Information systems Dept- SAMS, Maady Cairo, EgyptE-mail: Wessasalsol@Hossam Abdel Rahman MohamedComputer & Information System Dept- SAMS, Maady Cairo, EgyptE-mail: Hrahman@.eg, Habdel@.egAbstract—one of the most important techniques for improving the performance of web based applications is web proxy caching Technique. It is used for several purposes such as reduce network traffic, server load, and user perceived retrieval delays by replicating popular content on proxy caches that are strategically placed within the network. The use of web proxy caching is important and useful in the government organizations that provides services to citizens and has many branches all over the country where it is beneficial to improve the efficiency of the computer networks performance, especially remote areas which suffer from the problem of poor network communication. Using of proxy caches provides all users in the government computer networks by reducing the amount of redundant traffic that circulates through the network. It also provides them by getting quicker access to documents that are cached. In addition, there are a lot of benefits we can obtain from the using of proxy caches but we will address them later. In this research, we will use web proxy caching to provide all of the above benefits that we are mentioned above and to overcome on the problem of poor network communication in ENR (Egyptian National Railways). We are going to use a scheme to achieve the integration of forward web proxy caching and reverse proxy caching.Index Terms—Web Proxy Caching Technique, Forward proxy, Reverse ProxyI.IntroductionOne of the most well-known strategies for improving the performance of Web-based system is Web proxy caching by keeping Web objects that are likely to be used again in the future in location closer to user. The mechanisms The Web proxy caching are implemented at the following levels: client level, proxy level and original server level. [1], [2]it is known that proxy servers are located between users and web sites for lessening of the response time of user requests and saving of network bandwidth. We also should build an efficient caching approach in order to achieve better response time.Generally, we use web Proxy servers to provide internet access to users within a firewall. For security reasons, companies run a special type of HTTP servers called "proxy" on their firewall machines. When a Proxy server receives any requests from the clients, it forwards them to the remote servers intercepts the responses, and sends the replies back to the clients. Due to we use the same proxy servers for all clients inside of the firewall in the same organization, these clients share common interests and they would probably access the same set of documents and each client tends to browse back and forth within a short period of time, So this provides the effectiveness of using these proxies to cache documents. Therefore, this will increase the hit ratio for a previously requested and cached document on the proxy server in the future. In addition to web caching at proxy server saves network bandwidth, it also provides lower access latency for the clients.Most Web proxy servers are still based on traditional caching policies. These traditional caching policies only consider one factor in caching decisions and ignore the other factors that have impact on the efficiency of the Web proxy caching. Due to this reason these conventional policies are suitable in traditional caching like CPU caches and virtual memory systems, but they are not efficient in Web caching area. [3], [4]We use the proxy cache of the proxy server and it is located between the client machines and origin server. The work of the proxy cache is similar to the work of the browser cache in storing previously used web objects. The difference between them is the browser cache which deals with only a single user, the proxy server services hundreds or thousands of users. The work of the proxy cache is as follow, when the proxy server receives a request it checks its cache at first if therequest is found the proxy server sends the request directly to the client but if the request is not found the proxy server forwards the request to the origin server and after the origin server replies to the proxy server it forwards the request to the client and also save a copy from the request in local cache for future use. The proxy caching is used to reduce user delays and to reduce Internet congestions it is widely utilized by computer network administrators, technology providers, and businesses. [5], [6], [7]The proxy server uses its filtering rules to evaluate the request, so it may use IP address or protocol to filter the traffic. If the request is valid by the filter, the proxy provides the content by connecting to the origin server and requesting the service on behalf of the client in case the required content is not cached on the proxy server. The proxy server will return the content directly to the client if it was cached before by the proxy serverWe must consider the following problems before applying web proxy caching:Size of Cache: In traditional architectures each proxy server keeps records for data of all other proxy servers. This will lead in increasing in cache size and if cache size becomes large this will be a problem because as cache size is larger, Meta data become difficult to be managed. [8]Cache Consistency:We should ensure that Cache Consistency is verified to avoid Cache Coherence problem. Cache Consistency means when a client send requests for data to proxy server that data should be up-to-date. [9]Load balancing: There is must be a limit for number of connections to certain proxy server to avoid the problem of overloaded only one server than the other in case we use load balancing. [10]Extra Overhead:When all the proxy servers keep the records of all the other proxy servers, this will lead to extra overload in the system which already produces congestion on all proxy servers. This extra head due to each proxy server in the system must check the validity of its data with respect to all other proxy servers. [11]In addition to the proxy cache provide some advantages such as a reduction in latency, network traffic and server load, it also provides some more advantages∙Web proxy caching decreases network traffic and network congestion and this automatically reduces the consumption of bandwidth∙Web proxy caching reduces the latency because of the followings:A.When a client sends to the proxy server arequest already cached in the proxy server so inthis case the proxy server will reply directly tothe client instead of send the request to theorigin server.B.The reduction in network traffic will makeretrieving not cached contents faster because ofless congestion along the path and less workloadat the server.∙Web proxy caching reduces the workload of the origin Web server by caching data locally on the proxy servers over the wide area network.∙The robustness and reliability of the Web service is enhanced because in case the origin server in unavailable due to any failure in the server itself or any failure in the network connection between the proxy server and the origin server, the proxy server will retrieve the required data from its local cache.∙Web caching has a side effect that allows us a chance to analyze an organization's usage patterns.In addition to proxy caches provide a significant reduction in latency, network traffic and server load, they also produce set of issues that must be considered. ∙ A major disadvantage is the resend of old documents to the client due to the lack of proper proxy updating. This issue is the focus of this research.∙ A single proxy is a single point of failure.∙ A single proxy may become a bottleneck. A limit has to be set for the number of clients a proxy can serve. Therefore, in all government institution those provide services to citizen, we must be searched about methods and solutions to enhance the efficient of services delivery , and as we know that most places away from Cairo state is facing failure in the network because the lack of infrastructure and possibilities of the services provider (ISP).There has been a lot of research and enhancement in computer technology and the Internet has emerged for the sharing and exchange of information. There has been a growing demand for internet-based applications that generates high network traffic and puts much demand on the limited network infrastructure. We can use addition of new resources to the network infrastructure and distribution of the traffic across more resources as a possible solution to the problems of growing network traffic.Using of proxy caches in the government computer networks is useful to the server administrator, network administrator, and end user because it reduces the amount of redundant traffic that circulates through the network. And also end users get quicker access to documents that are locally cached in the caches. However, there are additional issues that need to be considered by using of proxies. In this study, we will focus on Web proxy caching since it is the most common caching method.1.1 Problem StatementThe governmental organizations which provide services to citizen must target efficient and more reliable services while keeping cost-effective criteria. Throughout this paper we consider the case of the Egyptian National Railway (ENR) datacenter which serve many applications supported to many branches spreaded allover Egypt which are quite faraway from Cairo state. Current infrastructure faces so many challenging problems leading to poor reliability as well as ineffective services and even more discontinuity of such services even at the headquarter datacenter. The main attributes of the problems facing the ENR network are summarized as following:∙ A major problem of the remote site is unstructured and their heavy network traffic.∙The network overloading might result in the loss of data packets∙The origin servers loaded most of the time∙Transmission delay –normal traffic data but low speed of the line.∙Queuing delay due to huge network traffic∙Slow the services that provided to citizens.∙Processing delay –due to any defection of the network device∙Network faults can cause loss of data∙Broadcast delay – due to presence of broadcasting on networkII.Proxy Caching OverviewCaches are often deployed as forward proxy caches, reverse proxy caches or as transparent proxies.2.1 Forward Proxy CachingThe most common form of a proxy server is a forward proxy; it is used to forward requests from an intranet network to the internet.[12]Fig. 2.1: Forward proxy cachingWhen the forward proxy receives a request from the client, the request can be rejected by the forward server or allowed to pass to the internet or [13] retrieved from the cache to the client. The last one reduces the network traffic and improves the performance.On the other hand, the forward proxy treats the requests by two different ways according to the requests are blocked or allowed. In case the request is blocked, the forward proxy returns an error to the client. In case the request is allowed, the forward proxy checks either the request is cached or not; if it is cached, the forward proxy returns cached content to the client. If it is not cached, the forward proxy forwards the request to the internet then returns the retrieved content from the intent to the client.The above figure explains the work of the forward proxy in case the request is allowed but not cached on the forward proxy A. the forward proxy will send the request to the server on the internet then the server on the internet return the required content to the forward proxy and finally the forward proxy return the received content to the client and cached it on its cache for future and same request. The cached content on the forward proxy will reduce the network traffic in the future and actually improves the performance of the whole system.2.2 Reverse Proxy CachingThe other common form of a proxy server is a reverse proxy; it performs the reverse function of the forward proxy, it is used to forward requests from an internet network to the intranet network. [14]This provides more security by preventing any hacking or an illegal access from the clients on the internet to important data stored on the content servers on the intranet network. By the same way, if the required content is cached on the reverse proxy, this will reduce the network traffic and improves the performance.[15]Fig. 2.2: Reverse proxy cachingThe advantages of reverse proxy are∙Solving single point of failure problem by using load balancing for content servers.∙Reducing the traffic on the content servers in case the request is blocked by the reverse proxy. In this case the request is rejected directly by the reverse proxy without interrupt the content servers.Reducing the bandwidth consumes by blocked requests as it is blocked directly by reverse proxy before reaching to the content servers.The function of the reverse proxy is the same as the function of the forward proxy except the request is initiated from the client on the internet to the content servers in the internal network. At first, the client on the internet sends a request to the reverse proxy. If the request is blocked, the reverse proxy returns an error to the client. If the request is allowed, the reverse proxy checks if the request is cached or not. In case the request is cached, the reverse proxy returns the content information directly to the client on the internet. In case the request is not cached, the reverse proxy sends the request to the content server in the internal network then resends the retrieved content from the content server to the client and also cached the content information from the content server for future requests to same content information [16]2.3 Transparent CachingTransparent proxy caching eliminates one of the big drawbacks of the proxy server approach: the requirement to configure Web browsers. Transparent caches work by intercepting HTTP requests and redirecting them to Web cache servers or cache clusters.[17]This style of caching establishes a point at which different kinds of administrative control are possible; for example, deciding how to load balance requests across multiple caches. There are two ways to deploy transparent proxy caching: at the switch level and at the router level. [18]Router-based transparent proxy caching uses policy-based routing to direct requests to the appropriate cache(s). For example, requests from certain clients can be associated with a particular cache.[19]In switch-based transparent proxy caching, the switch acts as a dedicated load balancer. This approach is attractive because it reduces the overhead normally incurred by policy-based routing. Although it adds extra cost to the deployment, switches are generally less expensive than routers.[20]III.Proxy Caching ArchitectureThe following architectures are popular: hierarchical, distributed and hybrid.3.1 Hierarchical Caching ArchitectureCaching hierarchy consists of multiple levels of caches. In our system we can assume that caching hierarchy consists of four levels of caches. These levels are bottom, institutional, regional, and national levels [21]The main object of using caching hierarchy is to reduce the network traffic and minimize the times that a proxy server needs to contact to the content server in the internet or in the internal network to provide the client with needed content information .These multiple caches works in that manner in case of forward proxy, at first the client initiate a request to the bottom level cache. If the needed content information is found and cached on it, it returns this information to the client directly. If this information is not cached on it, it will forward the client request to the next level cache that is institutional. If this cache found the needed information cached on it, it will return it to bottom level cache then the bottom level cache returns them to the client. If the needed information is not cached on it, it will forward the request to regional level. If the needed information is cached on it, it will return the needed information to the institutional level cache then the institutional level cache returns them to the bottom level cache and finally bottom level cache returns them to the client. If the needed information is not found not found on it, it will forward the request to the last level of cache that is national, if the needed information is found on that cache, it works the same way as above till the information reach to the client. If the needed information is not cached on that cache, it will forward the request to the content server on the internet and also repeat the same steps as above till the information reached to the client.In case of the reverse proxy, the same steps above are repeated except the request will forward by reverse way as in the forward proxy. Here, the request will forward from national level cache then to then to regional then to institutional bottom and finally to the content server in the internal network. The important note in caching hierarchy either in case of the forward proxy or the reverse proxy is each cache receives information from another level cache will cache a copy from thatinformation for future need to the same request.Fig. 3.1: Hierarichal caching architecture3.2 Distributed Caching ArchitectureIn distributed Web caching systems, there are no other intermediate cache levels than the institutional caches, which serve each others' misses. In order to decide from which institutional cache to retrieve a miss document, all institutional caches keep meta-data information about the content of every other institutional cache. With distributed caching, most of the traffic flows through low network levels, which are less congested. In addition, distributed caching allows better load sharing and are more fault tolerant. Nevertheless, a large-scale deployment of distributed caching may encounter several problems such as high connection times, higher bandwidth usage, administrative issues, etc.[22]There are several approaches to the distributed caching. Internet Cache Protocol (ICP), which supports discovery and retrieval of documents from neighboring caches as well as parent caches. Another approach to distributed caching is the Cache Array Routing protocol (CARP), which divides the URL-space among an array of loosely coupled caches and lets each cache store only the documents whose URL are hashed to it.[23]3.3 Hybrid CachingA hybrid cache scheme is any scheme that combines the benefits of both hierarchical and distributed caching architectures. Caches at the same level can cooperate together as well as with higher-level caches using the concept of distributed caching.[24]A hybrid caching architecture may include cooperation between the architecture's components at some level. Some researchers explored the area of cooperative web caches (proxies). Others studied the possibility of exploiting client caches and allowing them to share their cached data.One study addressed the neglect of a certain class of clients in researches done to improve Peer-to-Peer storage infrastructure for clients with high-bandwidth and low latency connectivity. It also examines a client-side technique to reduce the required bandwidth needed to retrieve files by users with low-bandwidth. Simulations done by this research group has proved that this approach can reduce the read and write latency of files up to 80% compared to other techniques used by other systems. This technique has been implemented in the OceanStore prototype (Eaton et al., 2004).[25]IV.Design Goals & Proposed ArchitectureTo improve the computer network performance, decrease the workload for data center and ensure continual service improvement, we aim to design efficient mechanisms for reducing the workload of a data center and business Continuity verification and achieve the following goals:∙Reduces network bandwidth usage consumption which leads to reduce network traffic and network congestion∙Decrease the number of messages that enter the network by satisfying requests before they reach the server.∙Reduces loads on the origin servers.∙Decreases user perceived latency∙Reduced page construction times during both normal loading and peak loading∙If the remote server is not available due to a server \crash" or network partitioning, the client can obtaina cached copy at the proxy.4.1 Proposed ArchitectureWe define before two types of proxies, the forward proxy and the reverse proxy. The forward proxy is used to forward clients from the clients on the internal network to the content server in the internet. The reverse proxy is used to forward requests from the clients in the internet to the content server in the internal network. Fig 5-1 shows that the forward proxy serves as a servant for internal clients and as a cache because it cached the content received from the content server on the internet. So for any the same repeated request, the forward server can return the cached content on it to the client directly without backing again to the content server. On the same time the forward proxy does an important rule as it hides the internal clients from outside world as the request is initiated from the forward proxy.Fig. 4.1: Proposed ArchitectureFig 4-1 also shows the reverse proxy that used to forward the requests from external clients to content servers in internal network. In this case the reverse proxy makes encrypting content, compressing content, reducing the load on content servers. It also hides the responses from internal networks and as them come from the reverse proxy which increases the security. It also caches the content and forwards it directly to clients if they repeated again without backing again to the content server. Finally, we can use load balancing to balance between content servers and in this case the reverse proxy and forward the request from the client to any of this content serves which increase the availability of the system.4.2 Proposed Architecture Workflow1The Remote Site client sends a request for Web Application content to the Forward proxy cache. If Forward proxy caching contains a valid version of the Web Application content in its cache, it will return the content to the requesting user. 2If the content requested by Remote Site user is not contained in the Forward proxy cache, the request is forwarded to an upstream Reverse proxy caching.3If the upstream Reverse Proxy Cache has a valid copy of the requested content in cache, the content is returned to Forward proxy cache (Remote Site). Forward proxy cache places the content in its own cache and then returns the content to the Remote Site user who requested the content.4If the upstream Reverse proxy caching does not contain the requested content in its cache, it will forward the request to the Web Application server. 5The Web Application server returns the requested content to reverse proxy caching. Reverse proxy caching places the content in cache.6Web Application server returns the content to reverse proxy caching. Reverse proxy caching server places the content in its cache. Reverse proxy caching server returns the content from its cache to Forward proxy. Forward proxy cache places the content in its own cache and then returns the content to the Remote Site user who requested the content.Fig. 4.2: Proposed workflowV.Performance AnalysisIn this chapter, we evaluate cache performance of web proxy caching for web applications and compare it to the case of not using web proxy caching at all. We will monitor and evaluate the performance of web proxy caching in three cases:∙Without using web proxy caching.∙At the beginning of using web proxy caching.∙After certain period (one month) from using web proxy caching.We will take in our consideration the following parameters in evaluation process ∙Requests returned from the application server.∙Requests returned from cache without verification. ∙Requests returned from the application server, updating a file in cache.∙Requests returned from cache after verifying that they have not changed.5.1 Performance MetricsThe seven main categories of performance metrics are:1.Cache Performance:how requested Web objects were returned from the Web Server cache or from the network. It will be measured the according to2.Traffic: the amount of network traffic, by date, sent through Web Proxy including both Web and non-Web traffic.3.Daily traffic:average network traffic through Web Proxy at various times during the day. This report includes both Web and non-Web traffic.4.Web Application Responses:how ISA Server responded to HTTP requests during the report period.5.Failures communicating:Web proxy Cache encountered the following failures communicating with other computers during the report period.6.Dropped Packets:shows the users who had the highest number of dropped network packets during the report period Users that had the most dropped packets are listed first7.Queue Length:The System\Processor Queue Length counter shows how many threads are ready in the processor queue, but not currently able to use the processor.VI.ResultsIn this section we will investigate the performance analysis of cache, Network traffic, Failure communication, Dropped packets and queue length 6.1 Cache PerformanceThe cache performance results for each of the log files are shown below. The percentage of requests returned from cache without verification is high. It shows that between 38% of all requests result in a request returned from cache without verification, which is consistent with previously published results. Wills and Mikhailov[26] reported that only 15% to 32% of their proxy logs result in requests returned from cache without verification. Yin, et al.[27]revealed that 20% of requests to the server are due to revalidation of cached documents that have not changed. These results are consistent with the results found in our logs as discussed before. However, with the current logs, the number of requests returned from cache without verification has increased a little. This may be due to the duration of the analysis being longer for this study or to the use of different logs. It is assumed that a large fraction of these frivolous requests are due to embedded objects that do not change often.Table ‎0-1: Cache Performance ResultsStatus Requests% of TotalRequestsTotalBytesObjects returned from the applicationserver20873 59.30 % 617.73 MBObjects returned from cache withoutverification13450 38.20 % 26.93 MBObjects returned from cache afterverifying that they have not changed489 1.40 % 0.99 MB Information not available 354 1.00 % 49.74 KB Objects returned from the applicationserver, updating a file in cache59 0.20 % 14.62 KBTotal 35225 100.00 % 645.72 MB6.2 TrafficThe results for average network traffic through web proxy caching Server at various times during the day at the beginning of using web proxy caching and after certain time from using web proxy caching are in Table below. The results indicate that the average processing time for handling the request is reduced by 43% after certain time of using web proxy caching because proxy caches the previous visited pages and return them directly to client without waste time to ask application server each time.To reflect the physical environment of the network, we have to consider factors influencing traffic. Of various factors influencing traffic, object size is a factor of the objects themselves. Hence, we can reflect the size factor of web object. An average object size hit ratio reflects the factor of object size to object-hit ratio. Average-object Hit Ratio: The cache-hit ratio can indicate an object-hit ratio in web caching. The average object-hit ratio can calculate an average value of an object-hit ratio on a requested page the performance is evaluated by comparing an average object-hit ratio and response time [28]Response Time gain factor (RTGF): This factor give you amount of advantage in web cache response time. [29]。

Analyzing the Performance ofClustering AlgorithmsClustering algorithms are widely used in various fields, such as data mining, machine learning, and pattern recognition, to group similar data points together. In this analysis, we will examine and compare the performance of three popular clustering algorithms: K-means, DBSCAN, and Hierarchical clustering.K-means is a centroid-based algorithm that partitions the dataset into K clusters by iteratively assigning data points to the cluster with the nearest centroid. It is a simple and efficient algorithm that works well with large datasets. However, it requires the number of clusters (K) to be specified in advance, which can be a drawback when the optimal number of clusters is unknown.DBSCAN (Density-Based Spatial Clustering of Applications with Noise) is a density-based algorithm that groups data points based on their density. It is able to discover clusters of arbitrary shapes and handle noise in the data. DBSCAN does not require the number of clusters to be specified beforehand, making it more flexible thanK-means. However, it is sensitive to the choice of two hyperparameters: epsilon (ε) and the minimum number of points (MinPts).Hierarchical clustering is a bottom-up approach that creates a hierarchy of clusters by successively merging or splitting data points. It does not require the number of clusters to be predefined and can be visualized as a dendrogram, which shows the relationships between data points and clusters at different levels of granularity. Hierarchical clustering is computationally intensive and may not be suitable for large datasets.To analyze the performance of these clustering algorithms, we will examine several key metrics:1. Silhouette Score: This metric measures how similar an object is to its own cluster compared to other clusters. A higher silhouette score indicates better cluster separation.2. Davies–Bouldin Index: This metric evaluates the average similarity between each cluster and its most similar cluster, relative to the average dissimilarity between objects in different clusters. A lower Davies–Bouldin index indicates better clustering.3. Rand Index: This metric measures the similarity between two clusterings by comparing the number of pairs of data points that are assigned to the same or different clusters in the two clusterings. A higher Rand index indicates better agreement between the two clusterings.4. Execution Time: This metric measures the time taken for each algorithm to cluster the dataset. Faster execution time is desirable for real-time applications or large datasets.In our analysis, we will apply these metrics to evaluate the performance of K-means, DBSCAN, and Hierarchical clustering on different datasets with varying sizes, shapes, and levels of noise. By comparing the results of these clustering algorithms, we can determine which algorithm is most suitable for a given dataset and application.Overall, each clustering algorithm has its strengths and weaknesses, and the choice of algorithm depends on the specific characteristics of the dataset and the goals of the analysis. By understanding and comparing the performance of different clustering algorithms, we can make informed decisions and improve the quality of clustering results in various applications.。

1、Which of the following is NOT a type of cloud service model?A. Software as a Service (SaaS)B. Platform as a Service (PaaS)C. Infrastructure as a Service (IaaS)D. Data as a Service (DaaS) (答案)2、In computer networking, what does the acronym "FTP" stand for?A. File Transfer ProtocolB. Fast Transfer ProtocolC. File Tracking ProtocolD. Full Transfer Power (答案: A)3、Which programming language is primarily used for web development and is known for its dynamic typing and use of JavaScript?A. PythonB. JavaC. JavaScriptD. C# (答案: C)4、Which of the following is a popular open-source relational database management system?A. OracleB. MySQLC. Microsoft SQL ServerD. IBM Db2 (答案: B)5、What is the primary function of a URL (Uniform Resource Locator)?A. To provide a unique identifier for web pages and other resources on the internetB. To encrypt data sent over the internetC. To control the appearance of web pagesD. To store user preferences for websites (答案: A)6、Which of the following HTML tags is used to create a hyperlink to another webpage?A. <link>B. <a>C. <href>D. <nav> (答案: B)7、In the context of computer security, what does the term "phishing" typically refer to?A. A type of malware that replicates itselfB. The act of attempting to acquire sensitive information through deceptive means, often via emailC. An attack that exploits vulnerabilities in software to gain unauthorized accessD. The process of encrypting data to protect it (答案: B)8、Which of the following is a web development framework primarily associated with the Ruby programming language?A. DjangoB. RailsC. LaravelD. Spring (答案: B)。

形合、意合与翻译-CAL-FENGHAI.-(YICAI)-Company One1形合、意合与翻译万江波提要: 形合和意合是英汉语言之间的重要区别特征,汉语以意驭形,而英语则以形制意。

由于语言与思维模式之间相互制约,西方形式逻辑的思维模式要求语言倚赖于各种连接手段承上启下。

而汉民族重内省和体悟,不重逻辑,因而语言简约、意义模糊。

一般来说,在译英为中时应以表“意”为核心进行遣词造句;译中为英时应先确定适当的“主谓”主线,再梳理脉络。

关键词: 形合;意合;思维模式1.形合和意合的概念众所周知,汉语和英语分属不同的语系:汉语属于汉藏语系,英语属于印欧语系。

它们在发音、构词法、句法、修辞形式以及谋篇布局方面都有各自的规律和特点,两者之间虽不乏相通之处,但也存在着明显的差异。

Eugene A. Nida说过，从语言学角度来看，英、汉语言之间最重要的区别莫过于形合（hypotaxis）与意合（parataxis）之分了（1982）。

“形合”和“意合”是已故语言学家王力先生所译。

形合指句子内部的连接或句子间的连接采用句法手段（syntactic devices）或词汇手段（lexical devices）。

意合指“句子内部的连接或句子间的连接采用语义手段（semantic connection）”（方梦之，2004）。

印欧语言重形合，语句各成分的相互结合常用适当的连接词语或各种语言连接手段，以表示其结构关系。

汉语重意合，句中各成分之间或句子之间的结合多依靠语义的贯通，少用连接语，所以句法结构形式短小精悍。

例如：The boy had his breakfast and went off to school.(男孩吃过早饭上学去了。

)这里英文中“his”跟“The boy”前后照应、相互攀连，“and”将两个承接的动作衔接起来,是英文形合的手段。

如果翻译时过于拘泥于原文的形合语言,译文会显得冗余累赘和拘谨(“男孩吃过他的早餐,然后上学去了”) ,而汉语里“吃过早饭上学去”两个连贯的动作显得很紧凑。