【導(dǎo)讀】摘要—在這篇文章中我們主要研究討論網(wǎng)絡(luò)信息檢索的基本問題。信息在網(wǎng)絡(luò)上是不。會(huì)被按照語義分類并儲(chǔ)存的。本文主要研究適合基于Ontology的搜索引擎的語義功能。本文也提供了關(guān)于提議改進(jìn)的搜索引擎的較深層次的結(jié)構(gòu)設(shè)計(jì)。與搜索結(jié)果相關(guān)聯(lián)的語義。間只存在一種單向的互動(dòng)，隨著技術(shù)的進(jìn)步,Web-enabled裝置越來越便宜,更無所不在的。這引發(fā)了一種在網(wǎng)站的使用和人們的互動(dòng)網(wǎng)。用戶還可以出版他們的資料以供其他使用者來購。內(nèi)容創(chuàng)作并不是僅僅局限于一。到了迅速的發(fā)展并逐漸的商業(yè)化。所有的這些都是利用數(shù)學(xué)算法通過計(jì)算頻率以及反任期期限的頻率來尖酸。低的結(jié)果準(zhǔn)確率將隨著信息搜集量的急劇增長(zhǎng)而進(jìn)一步惡化。第六部分描述了未來對(duì)這項(xiàng)工作的展望。專利并且是商業(yè)機(jī)密。排序算法將在下一。文中數(shù)據(jù)表明了NUTCH的索引以及搜索能力。引將會(huì)被分段，使得搜索器顯示查詢結(jié)果。模型采用一套<key、value>作為計(jì)算輸入。該輸入采用地圖功能,分析任務(wù)并生成中間鍵。

　　

【正文】 e system resources it can use. Maintainability is important to keep Zenith relevant in the future. When it is maintainable and scalable, the system can easily be enhanced for reliability. Fault tolerant capabilities can be implemented by making each ponent redundant. The introduction of ponent redundancy increases the system performance through loadbalancing. All in all, this methodology is designed and modified to specially suit the nature of Zenith development. Even though this model tries to capture as much development activities as possible is does not capture all. ANALYSIS OF GENERIC SEARCH ENGINE SKELETON Generic search engine skeleton describes the back bone of search engine. It consists of features and functionalities necessary for it to be identified and function as search engine. Generic Search Engine Skeleton had been derived from educational and experienced conjecture. In this research, Nutch [18] will be used as conventional search engine prototype. This prototype will enable better understanding of the mechanism and the nature of search engine. From the prototype, a semantic search engine design will be derived. This design is drafted in the proposed design section. A search engine consists of few major key ponents. These ponents are divided into two sections which are the front end and the back end. The main ponents were analyzed based on the architecture proposed by Brin [20] and analyzed by Manjula [21]. Nutch[18] is designed based on the skeleton that has a Back end and a Front end sections. We use this skeleton as the basis of the proposed design for semantic search engine. Few ponents are added and 26 modifications of the skeleton ponents are made in order to implement semantic capabilities. A. Backend Back end is where the process of getting and storing information gathered from the Web. Majority of the core functions and search engine capabilities depended on how the backend is designed. Backend has Web crawler, URL Server, Indexer and the storage. Web Crawler Web crawler is a script which is executed to retrieve Web pages based on the URL list stored in the URL server. To make Web crawling more effective, Web crawlers must be implemented in a way where many crawlers can simultaneously crawl multiple Web from the URL server. Threading implementation is required to enable concurrent processing. Another important functionality is the crawler has to be able to understand robot exclusion protocol. Webmaster that wants their site to be excluded from being crawl by crawlers can include robot exclusion protocol file. This file is a text file format which outlines which part of the site tree that is not accessible for the crawlers. Webmaster also can specify ways to guide the crawlers to crawl their Web site. Finally all the parsed data are store in a database of URL Server URL server acts as the storage for URL links. A list of URLs of monly visited sites is manually stored and bees the starting point for the crawlers. New URLs found by the crawler will be stored in the server. Indexer An indexer functions by indexing the parsed data into its according type. Indexer will ?organize? the data into categories. A document found by crawler will be parsed and indexed with a unique id, its data type, file and content. Indexer must be able to parse HTML, PDF, Words 27 and other documents found from the crawling activities. The data from the parsed HTML will be extracted and stored into a storage area such as database or custom data storage. Most implementations of search engine will press all the data in order to maximize storage space. B. Front End Front end has only one main ponent which is the searcher. This ponent acts as an intermediary between the user and the system. The ponent provides users the interface to obtain user search keyword. The keyword is then search in the reversed index which then will point to the links to the site. Multithreading capabilities is required in the searcher as many users will conduct search simultaneously. OVERALL ARCHITECTURE Zenith is an expansion for Nutch[18] that enables it to be a hybrid semantic search engine. The original design of data flow will be intercepted and modified before being rechanneled to the indexer. Figure 2 shows the overall architecture of Zenith model. 28 Figure 2. Nutch with Zenith Expansion Architecture Crudely the essence of the mechanism to implement the semantic capability is by utilizing ontology. The mechanism lies on how statements are extracted and manipulated to find semantic relation. Using external framework called Jena[22], ontology information is extracted in the form of: ?Subject Relationship Predicate? Subject represents classes or entity that the statement is describing. It could be bank name, payment method or etc. Predicate represents object or entity that the statement is describing. 29 Relationship describes how subjects and predicates are related. Semantic indexer will use the subject item as key term when searching documents crawled by crawler. Once found, it will then index the predicate in the index. Once all subject terms are pleted it will repeat the process using predicate and index the subject instead. Currently there are two types of relationship, positive and negative relationship. Positive depicts related relationship while negative depicts unrelated relationship. ZENITH EXPANSION ARCHITECTURE In Zenith expansion there are few ponents that work together to give Nutch[18] the ability the semantic ability. The ponents in Zenith expansion are semantic indexer, Jena framework, Ontology, Xerces and OntoIndex . C. Semantic Indexer All the core functionalities and the algorithm that orchestrate the process getting the data from the indexer, extract information from ontology using Jena [22] and incorporate semantic value in