外文資料翻譯--基于本體的應(yīng)用框架的網(wǎng)絡(luò)教育資源庫(kù)

1、畢業(yè)設(shè)計(jì)外文資料翻譯學(xué) 院： 信息科學(xué)與工程學(xué)院 專 業(yè)： 計(jì)算機(jī)科學(xué)與技術(shù) 姓 名： xxx 學(xué) 號(hào)： xxx (用外文寫)外文出處：_fengyang,youquan chen.ontology-based application framework for network eduction resources library. j.tsinghua science and technology, 2007,(4):3545. 附 件： 1.外文資料翻譯譯文；2.外文原文。 指導(dǎo)教師評(píng)語： 簽名： 年 月 日附件1：外文資料翻譯譯文基于本體的應(yīng)用框架的網(wǎng)絡(luò)教育資源庫(kù)馮陽(yáng)1，2，陳友全31（

2、計(jì)算機(jī)科學(xué)與技術(shù)，吉林大學(xué)，長(zhǎng)春，中國(guó)學(xué)院）2（信息學(xué)院，吉林教師的工程技術(shù)，長(zhǎng)春中國(guó)研究所）3（機(jī)械工程系，長(zhǎng)春工程技術(shù)研究所，長(zhǎng)春中國(guó)）摘要在過去的二十年，隨著互聯(lián)網(wǎng)應(yīng)用的迅速增長(zhǎng)，網(wǎng)絡(luò)教育已經(jīng)發(fā)展成為現(xiàn)行教育的主要組成部分。同時(shí)，基于語義的網(wǎng)絡(luò)教育資源成為教育技術(shù)在計(jì)算機(jī)和人工智能的重要研究領(lǐng)域。到目前為止，然而，在其申請(qǐng)的過程中了出現(xiàn)了一系列嚴(yán)重的瓶頸，例如：對(duì)網(wǎng)絡(luò)資源的標(biāo)準(zhǔn)是不兼容的，定義不嚴(yán)格和沒有有效性的語義，缺乏良好的結(jié)構(gòu)。解決這一問題，本文提出的工作顯示了網(wǎng)絡(luò)教育資源庫(kù)的新的應(yīng)用框架設(shè)計(jì)、實(shí)施。通過使用基于本體的語義技術(shù)，它創(chuàng)造了一個(gè)新的教育資源的開放式平臺(tái)，實(shí)現(xiàn)異構(gòu)互操作資

3、源，實(shí)現(xiàn)資源的集中管理和分布存儲(chǔ)的內(nèi)容。關(guān)鍵詞：網(wǎng)絡(luò)教育資源、語義web、本體論一、引言隨著網(wǎng)絡(luò)技術(shù)的進(jìn)一步發(fā)展和應(yīng)用需求的不斷出現(xiàn)，語義web成為一個(gè)在www研究領(lǐng)域的熱點(diǎn)和智能網(wǎng)絡(luò)服務(wù)的關(guān)鍵技術(shù)1。語義網(wǎng)在機(jī)器理解的基礎(chǔ)上可以提供關(guān)更多的功能，執(zhí)行語義層次的計(jì)算。它不僅能提供更清晰和更全面的語義的網(wǎng)絡(luò)信息和知識(shí)，而且還實(shí)現(xiàn)了計(jì)算機(jī)可以了解網(wǎng)絡(luò)信息和知識(shí)，以及網(wǎng)絡(luò)數(shù)據(jù)處理和網(wǎng)絡(luò)服務(wù)的智能化。語義網(wǎng)絡(luò)在網(wǎng)絡(luò)服務(wù)，基于代理的分布式計(jì)算，基于語義的搜索引擎，基于語義的數(shù)字圖書館等領(lǐng)域成為一個(gè)更重要的應(yīng)用。在同時(shí)，隨著應(yīng)用研究的持續(xù)的深入，作為語義網(wǎng)絡(luò)的關(guān)鍵技術(shù)本體論技術(shù)趨于成熟，語義元數(shù)據(jù)描述方法

4、的形成和語義網(wǎng)絡(luò)的發(fā)展開始進(jìn)入實(shí)際應(yīng)用階段，例如基于語義的信息表示和語義為基礎(chǔ)的數(shù)字圖書館、數(shù)字博物館有了初步的探索和應(yīng)用和其他應(yīng)用程序搜索應(yīng)用2。網(wǎng)絡(luò)教育資源是計(jì)算機(jī)教育和人工智能的重要研究領(lǐng)域。建構(gòu)主義學(xué)習(xí)理論認(rèn)為學(xué)習(xí)環(huán)境的四個(gè)要素是：上下文、協(xié)作、會(huì)話和意義建立。隨著計(jì)算機(jī)網(wǎng)絡(luò)和多媒體技術(shù)的發(fā)展，由于建構(gòu)主義理論的影響，人們學(xué)習(xí)的方式改變了很多，從以傳統(tǒng)的教學(xué)資源為基礎(chǔ)的教學(xué)到以資源為基礎(chǔ)的學(xué)習(xí)3。隨著建構(gòu)主義學(xué)習(xí)理論作為指導(dǎo)，它是人類社會(huì)在21世紀(jì)的數(shù)字識(shí)字發(fā)展的重要方向，建立堅(jiān)固的網(wǎng)絡(luò)教育資源，它可以選擇教學(xué)內(nèi)容和教學(xué)模式，根據(jù)學(xué)生的實(shí)際情況、實(shí)施個(gè)性化指導(dǎo)學(xué)生。網(wǎng)絡(luò)教育資源起源于電

5、腦輔助教學(xué)系統(tǒng)的發(fā)展，其主要特征是，根據(jù)用戶的具體情況提供適當(dāng)?shù)慕滩?，換句話說，它有個(gè)別教學(xué)的功能，此功能的實(shí)現(xiàn)是通過人工智能的手段4。但是，當(dāng)前網(wǎng)絡(luò)教育資源的也有一些問題，如下：（1）檢索效率低教授的知識(shí)過多而且廣泛，傳統(tǒng)的基于關(guān)鍵字的搜索技術(shù)無法滿足需要。使用適當(dāng)?shù)谋倔w來描述教育資源庫(kù)和建立以本體論為基礎(chǔ)的知識(shí)架構(gòu)來解決這些問題是非常必要的。（2）弱語義高的語義對(duì)于應(yīng)用不同的教育平臺(tái)之間的交流是必要的。使交流和知識(shí)共享成為困難的原因是描述教學(xué)知識(shí)的基本標(biāo)準(zhǔn)并不是任何時(shí)間都是一樣的，知識(shí)以不同的方式表示5。（3）缺乏情報(bào)當(dāng)前的很多教學(xué)系統(tǒng)不能學(xué)生做有針對(duì)性的學(xué)習(xí)，使教師無法準(zhǔn)備合適的學(xué)習(xí)內(nèi)容

6、跟隨學(xué)生的認(rèn)知模式，通過了解他們的認(rèn)知特點(diǎn)和學(xué)習(xí)的變化來引導(dǎo)學(xué)生。為應(yīng)對(duì)當(dāng)前的教育資源建設(shè)和應(yīng)用需求的問題，本文介紹了語義的關(guān)鍵技術(shù)是建設(shè)教育資源，提出了基于語義網(wǎng)絡(luò)技術(shù)為基礎(chǔ)的教育資源的主要框架，開始于教育資源建立的有意義的方面，如基于語義的元數(shù)據(jù)描述、教育、資源庫(kù)本體模型、資源池之間的模式匹配、討論了框架和關(guān)鍵技術(shù)的核心理念。二、本體在本節(jié)中，提出了最容易被人接受的本體理解。由于本體是用于描述在語義和知識(shí)層次的信息系統(tǒng)中的概念模型，它已被用于許多領(lǐng)域。由于本體是不是一個(gè)靜態(tài)的模型，它必須有能力獲取意義和關(guān)系的變化。在人工智能領(lǐng)域的研究，有許多關(guān)于本體的定義。其中，最經(jīng)常采用的是格魯伯的關(guān)于

7、本體的定義，即本體是一個(gè)明確的規(guī)范概念化6。一個(gè)本體o是一個(gè)五元組o=(c, i, r, f, a)，其中c，i是分別的概念和實(shí)例。r是一個(gè)關(guān)系集，f是c上面的函數(shù)，a是一系列（本體論）公理- 指定了在一些論述領(lǐng)域的詞匯的解釋。以格魯伯為基礎(chǔ)的定義，還有一些本體匹配類型：概念與概念、屬性的概念、屬性與性質(zhì)，場(chǎng)景和約束等6。本體論在教育資源庫(kù)的構(gòu)造中起著重要的作用，它可以實(shí)現(xiàn)三方共享5：(1)資源內(nèi)容共享。這意味著，資源庫(kù)像每個(gè)人提供資源，與此同時(shí)，從每個(gè)人那里獲取自己本身沒有的資源。(2)技術(shù)分享。這意味著，當(dāng)不同的組織或個(gè)人建立他們自己的資源庫(kù)，如果他們按照相同的標(biāo)準(zhǔn)，同樣的資源表示方式和相

8、同的屬性標(biāo)記方法，那么他們可以共享同一接口。(3)概念共享。這意味著，在實(shí)現(xiàn)語義理解，確保不同的對(duì)象建立，維護(hù)和使用過程中這方面的知識(shí)分享同一個(gè)概念。三、框架概述 我們?yōu)榫W(wǎng)絡(luò)教育資源庫(kù)設(shè)計(jì)了一個(gè)以本體論為基礎(chǔ)的應(yīng)用程序框架。它可以實(shí)現(xiàn)教育資源的訪問和重用，實(shí)現(xiàn)教育資源和優(yōu)化資源之間的生命周期管理機(jī)制的分布式資料庫(kù)的互操作性。最重要的是，它提供基于語義的搜索，因?yàn)檫@種制度框架提供一個(gè)綜合的、面向全球的本體表示的概念和機(jī)制，以及基于語義的資源規(guī)劃。該框架結(jié)構(gòu)由三部分組成。如圖1所示。這一框架的更多的技術(shù)細(xì)節(jié)將在第四部分討論。a、表示層它是用戶和系統(tǒng)之間的互動(dòng)界面。用戶通過瀏覽器訪問系統(tǒng)。用戶界面負(fù)

9、責(zé)接收查詢和顯示搜索結(jié)果給用戶。在這層，雖然他們是被采用的，但是本體保護(hù)用戶的網(wǎng)頁(yè)。因此，網(wǎng)頁(yè)語義信息對(duì)用戶是透明的。為了實(shí)現(xiàn)顯示與邏輯分離這一目標(biāo)，jsp和javabean技術(shù)已被用于在本層的開發(fā)。b、邏輯層作為主要的應(yīng)用程序邏輯層，它進(jìn)行系統(tǒng)的知識(shí)檢索。它由五個(gè)部分組成，即本體管理組件、語義分析組件、推理引擎、查詢組件、web信息訪問組件。在用戶的查詢請(qǐng)求被搜索引擎提交后，語義分析組件獲得概念和語義關(guān)系，用戶通過語義分析需求，然后jena owl的推理引擎負(fù)責(zé)對(duì)這個(gè)概念和語義關(guān)系的基礎(chǔ)上的推理，最終查詢beans類訪問此資源的本體庫(kù)和查詢結(jié)果返回給用戶。c、數(shù)據(jù)層數(shù)據(jù)層是由三個(gè)部分組成：本

10、體庫(kù)、教育資源描述數(shù)據(jù)庫(kù)和mysql/db2/oracle數(shù)據(jù)庫(kù)。作為知識(shí)資源本體的存儲(chǔ)介質(zhì)，這一層是負(fù)責(zé)建立和從新結(jié)構(gòu)性的描述owl為基礎(chǔ)的知識(shí)本體，這是知識(shí)檢索的直接來源。此外，為了實(shí)現(xiàn)知識(shí)共享和重用，它會(huì)進(jìn)行語義標(biāo)注相關(guān)資源的網(wǎng)頁(yè)并存儲(chǔ)在數(shù)據(jù)采集元件本體庫(kù)中。圖1、本體論為基礎(chǔ)的框架的網(wǎng)絡(luò)教育資源庫(kù)四、框架的關(guān)鍵技術(shù)本節(jié)中對(duì)這一框架的關(guān)鍵技術(shù)進(jìn)行介紹。它包括網(wǎng)絡(luò)服務(wù)、用戶的要求處理、語義分析和推理引擎。a、網(wǎng)絡(luò)服務(wù)表示層也可以作為網(wǎng)絡(luò)服務(wù)層稱，其主要任務(wù)是實(shí)現(xiàn)與用戶的交互。在很多資源建設(shè)方式的情況下，選擇網(wǎng)絡(luò)服務(wù)技術(shù)，以集成分布式有效的教育資源庫(kù)和共享它們之間的信息。在各種平臺(tái)的異構(gòu)基礎(chǔ)

11、上，網(wǎng)絡(luò)服務(wù)可用來建立一個(gè)共同的與平臺(tái)無關(guān)，語言無關(guān)的技術(shù)，不同平臺(tái)的應(yīng)用程序依賴于去實(shí)現(xiàn)連接以及它們之間的融合。在整個(gè)資源庫(kù)，作為服務(wù)供應(yīng)商，每個(gè)地方的資源制定自己的服務(wù)和功能補(bǔ)充全球系統(tǒng)，它的uddi（通用描述，發(fā)現(xiàn)和集成）。uddi是負(fù)責(zé)注冊(cè)和發(fā)送工作。在此，所有的信息通過soap（簡(jiǎn)單對(duì)象訪問協(xié)議）被發(fā)送到整個(gè)系統(tǒng)。b、用戶請(qǐng)求處理在我們的框架，用戶通過普通的連接方法進(jìn)行資源搜索，這些領(lǐng)域被限制或自然聲明。學(xué)習(xí)對(duì)象屬于不同的本地資源，它們?cè)诘乩砦恢蒙戏珠_。不同的資源庫(kù)通常根據(jù)不同的計(jì)算機(jī)平臺(tái)、數(shù)據(jù)格式和編程語言建立，它提供了他們自己的機(jī)制來查詢和訪問資源。在這種情況下，中央服務(wù)器需要一

12、定的機(jī)制來確定當(dāng)?shù)氐目商峁┓?wù)器資源庫(kù)，然后用戶的請(qǐng)求將被發(fā)送到本地服務(wù)器。在具體系統(tǒng)設(shè)計(jì)我們指的是一系列數(shù)學(xué)的方法8。圖2說明了用戶要求如何由這些模塊處理。c、語義分析 在我們的框架中，語義分析是負(fù)責(zé)通過搜索引擎，提交用戶的請(qǐng)求。該機(jī)器的用戶表示需要語義本體庫(kù)查詢，分析用戶意圖和使用jena owl推理機(jī)制來完成。由于用戶查詢?cè)谝欢ǔ潭壬系牟淮_定性，根據(jù)用戶的需要擴(kuò)大查詢的概念集合是可行的。語義擴(kuò)展規(guī)則的定義為：如果o是literlas類型，則s是擴(kuò)張中心，查詢的概念可根據(jù)學(xué)的概念和屬性關(guān)系獲得。如果s不存在，這些概念是不能采取。 如果o是一種資源，那么o是擴(kuò)張中心，查詢的概念可根據(jù)o的概念

13、和屬性關(guān)系獲得。查詢處理是語義檢索最重要的部分。它可以被描述為以下國(guó)際扶輪模型：本體模型和基于本體的網(wǎng)絡(luò)資源、識(shí)別模型。在這些中，網(wǎng)絡(luò)資源r和查詢q是基于本體o構(gòu)建的，他們是有關(guān)的，當(dāng)且僅當(dāng)r滿足q：它描述了r和o意味著邏輯上查詢q：or-q9。圖2、用戶要求處理有兩種行之有效的方法，可以把查詢關(guān)鍵字轉(zhuǎn)換成本體描述。文獻(xiàn)10提出了一種基于語義的檢索方法：本體匹配圖，也就是語義實(shí)在本體、關(guān)系和本體圖之間的相關(guān)性提出來的。根據(jù)這些語義的相關(guān)性，本體圖匹配的框架，它可以計(jì)算這些相互關(guān)系設(shè)計(jì)。在文獻(xiàn)11中給出了另外一種語義檢索想法。它提出了一個(gè)搜索的體系結(jié)構(gòu)，它結(jié)合激活擴(kuò)散應(yīng)用于一個(gè)特定領(lǐng)域的語義模型

14、古典搜索技術(shù)。給定的本體，權(quán)衡被分配給連接基于特定本體的屬性，因此他們測(cè)量的關(guān)系的強(qiáng)度。激活擴(kuò)散技術(shù)用于尋找在本體相關(guān)概念給出的概念和相應(yīng)的初始值，初始設(shè)置激活。這些初始值是從應(yīng)用到與本體的概念相關(guān)的數(shù)據(jù)古典搜索的結(jié)果。兩個(gè)測(cè)試?yán)龑?shí)施，具有非常積極的成果。有人還指出，提出的混合激活擴(kuò)散，結(jié)合象征和子象征性的辦法，當(dāng)和每個(gè)單獨(dú)的方法相比取得了較好的結(jié)果11。d、推理引擎這是整個(gè)框架的關(guān)鍵控制模塊。通過推理和搜索，將得到知識(shí)用戶的需要，與此同時(shí)，智能教學(xué)方法和策略也可以得到。推理引擎負(fù)責(zé)解析和推理owl文件負(fù)責(zé)。這樣做的目的從一般的文件中讀取本體，用特定的模式存儲(chǔ)是為了方便處理，然后在按照一定的規(guī)

15、則進(jìn)行基于本體的語義推理，這是語義檢索的關(guān)鍵一步。此過程使用jena開發(fā)套件來執(zhí)行。如圖3所示，推理機(jī)的工作原理是：推理引擎注冊(cè)機(jī)制，推理機(jī)的基礎(chǔ)上創(chuàng)建基本的rdf三元組和本體。經(jīng)過這一過程，模型對(duì)象中包含推理機(jī)制，inefreneegnarh和ingfraph可以生成。在jena中，garph也被稱為模型及其表現(xiàn)形式是modelinterafee。然后，它可以對(duì)運(yùn)行和處理這一模式利用該模型api和onotlogy空氣污染指數(shù)，因此語義層次上的信息檢索可以實(shí)現(xiàn)。圖3、推理機(jī)的工作原理五、結(jié)論與未來在這個(gè)文件中，我們提出了一個(gè)新的網(wǎng)絡(luò)教育資源庫(kù)的應(yīng)用框架設(shè)計(jì)、實(shí)施。通過使用基于本體的語義技術(shù)，我

16、們創(chuàng)建了一個(gè)新的教育資源的開放平臺(tái)，實(shí)現(xiàn)異構(gòu)資源之間的互操作，實(shí)現(xiàn)資源的集中管理和分布存儲(chǔ)的內(nèi)容。在此基礎(chǔ)上，資源庫(kù)可以成為共享、分布、開放和異構(gòu)資源之間進(jìn)行互操作得到支持。隨著教育的快速發(fā)展，課程也在發(fā)生變化。生產(chǎn)和教育資源的更新是越來越頻繁。通過利用本體論表達(dá)和工作流程的標(biāo)準(zhǔn)化，建立教育資源庫(kù)的基礎(chǔ)上的共同標(biāo)準(zhǔn)，廣泛的資源共享和再利用可以達(dá)到的理念和形成共識(shí)。這將是建設(shè)和發(fā)展教育資源庫(kù)的重要方向。在今后的工作中，我們將沿著三個(gè)方向延伸我們當(dāng)前的工作。第一個(gè)是該體系結(jié)構(gòu)的改善。第二個(gè)方向是實(shí)現(xiàn)當(dāng)設(shè)計(jì)到我們這個(gè)框架的數(shù)據(jù)集可用時(shí)，設(shè)計(jì)出更復(fù)雜的本體。最后是與其他網(wǎng)絡(luò)教育資源庫(kù)進(jìn)行比較。鳴謝這項(xiàng)

17、工作是受國(guó)家自然科學(xué)基金委員會(huì)中國(guó)委員會(huì)（nsfc），410073no.60873044和專項(xiàng)科研基金批準(zhǔn)號(hào)：20060183044下的中國(guó)高等教育的教育博士課程。附件2：外文原文（復(fù)印件）ontology-based application framework for network education resources libraryfeng yang1,2, youquan chen31(college of computer science and technology, jilin university, changchun, china)2(college of informat

18、ion, jilin teachers institute of engineering and technology, changchun china)3(department of mechanical engineering, changchun institute of engineering technology, changchun china), qabstractin past twenty years, as the rapid growth of internet application, n

19、etwork education has grown a main part of current education. at the same time, semantic-based network educational resource became an important research field in computer education technology and ai. so far, however, there is a serious of bottlenecks in the progress of their applications, e.g. the cr

20、iterion of web resource is not compatible, the semantic definition is not strict and the validity and well-structure are absent. addressing this issue, the work presented in this paper shows the design, implementation of a new application framework for network education resources library. by using o

21、ntology-based semantic technology, it creates an open platform for new educational resources, achieves interoperation between heterogeneous resources and realizes the centralized management of resources and contents distributed stored. keywords- network education resources; semantic web; ontology i.

22、 introduction with the further development of network technology and the unceasing emergence of application requirements, semantic web becomes a hotspot in www research field and a key technology of intelligent network services 1.the semantic web can provide more extensive application functions on t

23、he basis of the machine understanding and perform computation at the semantic level. it does not only give clearer and more completely semantic to the network information and knowledge, but also achieves that computers can understand the network information and knowledge, and the intelligentization

24、of the network data processing and network services. semantic web becomes a more important application in the fields as network services, agent-based distributed computing, semantic-based search engine, semantic-based digital library and so on. at the same time, with the continuous deepening of the

25、applied research, the ontology technique as a key research of semantic web tends to be sophisticated, and there is a formation of semantic metadata describing methods, and development of semantic web begins to enter the practical application stage, such as that there is an initial exploration and ap

26、plication of semantic-based information representation and semantic-based searching in digital libraries and digital museums and other applications2. network educational resource is an important research field on computer education technology and ai. constructivist learning theory holds that the fou

27、r elements of the learning environment are context, collaboration, conversation, and meaning built. with the development of computer network and multimedia technology, the ways people learn changed a lot under the influence of the constructivist theory, from traditional teaching to the resource-base

28、d teaching, and then to resource-based learning 3. with constructivist learning theory as a guide, it is an important direction of the development of human society in the 21st century digital literacy to build the stablish network educational resources which can select teaching content and teaching

29、pattern according to the actual situation of students, implement individualized instruction for students. network educational resources originated in the development of computer-aided education systems, its main feature is that according to the specific circumstances of the user to provide appropria

30、te teaching material, in other words, it has the function of individual teaching, this feature is achieved by means of ai 4. but, there are some problems of current network educational resources as follows: (1) low retrieval efficiency for teaching knowledge is excessive and extensive, the tradition

31、al keyword-based search technology can not meet the needs. it is necessary to use appropriate ontology to describe educational resources library and build ontology-based knowledge architecture for solving these problems. (2) weak semantic high semantic is necessary for communication between differen

32、t educational application platforms. the reason why making the exchange and sharing of knowledge difficult is that standard of describing the teaching knowledge base is not the same all the time and the knowledge represents in different ways5. (3) lack of intelligence a lot of current teaching syste

33、ms can not provide student information automatically for students to do targeted studying, and make teachers unable to prepare the suitable learning content following the cognitive model of students, and guide the student to learn by their cognitive characteristics and the changes in learning. in re

34、sponse to problems of the current education resources construction and application needs, this paper introduced key technology of semantic to the building of education resources, presented the primary frame of education resources based on semantic web technologies, started with the significant aspec

35、ts of the building of education resources, such as semantic-based metadata description, education and resource library ontology model, pattern matching between the resource pool, and discussed the core concept of the framework and key technology. ii. ontology in this section the most generally accep

36、ted understanding of ontology is presented. since ontology is a conceptual model which is used for describing information systems on the level of semantics and knowledge, it has been used in many fields. since ontology is not a static model, it has to have the ability to capture the changes of meani

37、ngs and relations. in research field of ai, there are many definitions of ontology. among them, the most frequently adopted is gruber, that is, an ontology is an explicit specification of a conceptualization 6. an ontology o is a 5-tuple o=(c, i, r, f, a), where c, i are concepts and instances respe

38、ctively. r is a relation set, f is a function above c, and a is a set of (ontological) axioms-specifying the intended interpretation of the vocabulary in some domain of discourse. base on grubers definition, there are some types of ontology matching: concept to concept, property to concept, property

39、 to property, scenario and constraint and so on 6.ontology plays an important role in the construction of the educational resources library, which can achieve tripartite sharing 5: sharing of resources contents. it means that resource libraries provide resources to each other, at the same time get r

40、esources they do not have from each other. sharing of technology. it means that when different organizations or individual build their own resources library, if they can follow the same standard , the same resource representation mode and the same attribute marking method, then they can share one in

41、terface. sharing of concepts. it means that for achieving semantic understanding, make sure that the different objects being established, maintened and used of knowledge during this area share the same concept. iii. framework overview we designed an ontology-based application framework for network e

42、ducation resources library. it can realize the access and reuse of education resources, achieve the interoperability between the distributed repositories of educational resources and optimize resource life-cycle management mechanism. most importantly, it provides semantic-based search, because such

43、a system framework provides an integrated, global-oriented concepts and ontology representation mechanisms, and the semantic-based resource formulation. the structure of the framework consists of three parts. it is shown in figure 1. more technology details of this framework will be discussed in par

44、t iv. a. representation layer it is the interactional interface between user and system. users access the system through a browser. the user interface is responsible for receiving queries and displaying the search results to the user. in this layer, the ontologies are shielded to users web page, tho

45、ugh they are adopted. so the semantic information of web page are transparent to the user. in order to achieve this separation of display and logic, jsp and java bean technology have been used in the development of this layer. b. logic layer as the main application logic layer, it carries on the ret

46、rieval of system knowledge. it consists of five parts, namely, ontology management component, semantic analysis component, inference engine, query component, and web information access component. after users query requests are submitted by search engine, semantic analysis component obtains the conce

47、pts and semantic relations that user needs through the semantic analysis, and then jena owl inference engine takes on reasoning on the basis of this concepts and semantic relations, ultimately the query beans accesses this resource ontology library and returns the query results to the user. c. data

48、layer data layer is composed of three parts: ontology library, education resource description database and mysql/db2/oracle database. as the storage medium of knowledge resource ontology, this layer is responsible for creating and refining a structural description of the owl-based knowledge ontology

49、, which is the direct source of knowledge retrieval. in addition, in order to achieve knowledge sharing and reuse, it will carry out semantic annotation to the relevant resources in the web page and store them in the ontology library by the data acquisition components.fig 1. ontology-based framework

50、 for network education resources libraryiv. key technologies of framework in this section the key technologies of this framework are presented. it includes web services, processing of user request, semantic parsing and inference engine. a. web services representation layer may also be known as the n

51、etwork service layer, its main task is to achieve interaction with the user. under the case of a variety of the resource building ways, the web service technologies are selected in order to integrate distributed resource library of education effectively and share information between them. on the bas

52、is of a variety of heterogeneous platforms, web services are available to build a common platform-independent, language-independent technical level, which applications of different platform rely on to implement the connection and integration between them. throughout the resource library, as a servic

53、e provider, each local resource make their own services and features promulgate to the global system, which uddi (universal description discovery and integration) on it. and then the uddi is responsible for the registration and sending. in this, all the information is send to the entire system throu

54、gh the soap (simple object access protocol). b. processing of user request in our framework, user takes on resource search by an ordinary combination method that fields are limited or natural statement. learning objects belong to different local resources, they are geographically separated. differen

55、t resource libraries are usually built on different computer platforms, data formats and programming languages, which provide their own mechanisms to query and access resources. in this case, the central server needs a certain mechanism to orient local resource libraries that can provide server, and

56、 then user request will be sent to local servers. in the specific system design, we refer to a number of mathematical methods 8. figure 2 illustrates how a user request to be processed by these modules. c. semantic parsing in our framework, semantic parsing is responsible for the transition from the

57、 user requests submitted by search engine to concepts of ontology. the conversional process of user semantic to machine presentation need query ontology library, analyze user intents and use jena owl inference mechanism to complete. as user query are uncertainty in a certain degree, it is feasible t

58、hat expand the concept set of queries according to the needs of users. semantic expansion rule is defined as: if o is literlas type, then s is the center of expansion, the concepts for a query can be obtained according to the concepts and attribute relations of s. if s does not exist, the concepts are not to be taken. if o is a reso