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1.
Deep Web sources contain a large of high-quality and query-related structured date. One of the challenges in the Deep Web is extracting result schemas of Deep Web sources. To address this challenge, this paper describes a novel approach that extracts both result data and the result schema of a Web database. The approach first models the query interface of a Deep Web source and fills in it with a specifically query instance. Then the result pages of the Deep Web sources are formatted in the tree structure to retrieve subtrees that contain elements of the query instance, Next, result schema of the Deep Web source is extracted by matching the subtree' nodes with the query instance, in which, a two-phase schema extraction method is adopted for obtaining more accurate result schema. Finally, experiments on real Deep Web sources show the utility of our approach, which provides a high precision and recall.  相似文献   

2.
The demand for individualized teaching from Elearning websites is rapidly increasing due to the huge differences existed among Web learners. A method for clusteringWeb learners based on rough set is proposed. The basic ideaof the method is to reduce the learning auributes prior to clustering, and therefore the clustering of Web learners iscarried out in a relative low-dimensional space. Using thismethod, the E-learning websites can arrange correspondingleaching content for different clusters of learners so that thelearners‘ individual requirements can be more satisfied.  相似文献   

3.
Web offers a very convenient way to access remote information resources, an important measurement of evaluating Web services quality is how long it takes to search and get information. By caching the Web server‘s dynamic content, it can avoid repeated queries for database and reduce the access frequency of original resources, thus to improve the speed of server‘s response. This paper describes the concept. advantages, principles and concrete realization procedure of a dvnamic content cache module for Web server.  相似文献   

4.
Focused crawlers are important tools to support applications such as specialized Web portals, online searching, and Web search engines. A topic driven crawler chooses the best URLs and relevant pages to pursue during Web crawling. It is difficult to deal with irrelevant pages. This paper presents a novel focused crawler framework. In our focused crawler, we propose a method to overcome some of the limitations of dealing with the irrelevant pages. We also introduce the implementation of our focused crawler and present some important metrics and an evaluation function for ranking pages relevance. The experimental result shows that our crawler can obtain more "important" pages and has a high precision and recall value.  相似文献   

5.
Distributed denial of service (DDoS) attacks exploit the availability of Web servers, resulting in the severe loss of their connectivity. We present a robust IP packets filtering mechanism which combines the detection and filtering engine together to protect Web Servers from DDoS Attacks. The mechanism can detect DDoS attacks by inspecting inbound packets with an IP address database, and filter out lower priority IP addresses to preserve the connection for valid users by monitoring the queues status. We use the Netfilter's technique, a framework inside the Linux 2.4. X, to implement it on a Web server. Also, we evaluate this mechanism and analyze the influence of some important parameters on system performance. The experimental results show that this mechanism is effective against DDoS attacks.  相似文献   

6.
This paper analyzed the theory of incremental learning of SVM (support vector machinc) and pointed out it is a shortage that the support vector optimization is only considered in present research of SVM incremental learning. According to the significance of keyword in training, a new incremental training method considering keyword adjusting was proposed, which eliminates the differcnce hetween incremental learning and batch learning through the keyword adjusling. The experimental results show that the improved method outperforms the method without the keyword adjusting and achieve the same precision as the hatch method.  相似文献   

7.
We propose an algorithm for learning hierarchical user interest models according to the Web pages users have browsed. In this algorithm, the interests of a user are represented into a tree which is called a user interest tree, the content and the structure of which can change simultaneously to adapt to the changes in a user's interests. This expression represents a user's specific and general interests as a continuurn. In some sense, specific interests correspond to shortterm interests, while general interests correspond to longterm interests. So this representation more really reflects the users' interests. The algorithm can automatically model a us er's multiple interest domains, dynamically generate the in terest models and prune a user interest tree when the number of the nodes in it exceeds given value. Finally, we show the experiment results in a Chinese Web Site.  相似文献   

8.
A kind of Web voice browser based on improved synchronous linear predictive coding (ISLPC) and Text-toSpeech (TTS) algorithm and Internet application was proposed. The paper analyzes the features of TTS system with ISLPC speech synthesis and discusses the design and implementation of ISLPC TTS-based Web voice browser. The browser integrates Web technology, Chinese information processing, artificial intelligence and the key technology of Chinese ISLPC speech synthesis. It's a visual and audible web browser that can improve information precision for network users. The evaluation results show that ISLPC-based TTS model has a better performance than other browsers in voice quality and capability of identifying Chinese characters.  相似文献   

9.
Forms enhance both the dynamic and interactive abilities of Web applications and the system complexity. And it is especially important to test forms completely and thoroughly. Therefore, this paper discusses how to carry out the form testing by different methods in the related testing phases. Namely, at first, automatically abstracting forms in the Web pages by parsing the HTML documents; then, ohtai ning the testing data with a certain strategies, such as by requirement specifications, by mining users' hefore input informarion or by recording meehanism; and next executing the testing actions automatically due to the well formed test cases; finally, a case study is given to illustrate the convenient and effective of these methods.  相似文献   

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12.
This paper studies the digit watermark technology of numeric attributes in relational database for database‘s information security. It proposes a new mechanism based on similar clouds watermark and gives the concept of similar clouds. The algorithm SCWA that can insert the meaning wa-termark and detect it from the watermarked data is described. The mechanism can effectively and broadly scatter the watermark in the database; therefore the watermark is very robust.  相似文献   

13.
The most significant strategic development in information technology over the past years has been "trusted computing" and trusted computers have been produced. In this paper trusted mechanisms adopted by PC is imported into distributed system, such as chain of trust, trusted root and so on. Based on distributed database server system (DDSS), a novel model of trusted distributed database server system (TDDSS) is presented ultimately. In TDDSS role-based access control, two-level of logs and other technologies are adopted to ensure the trustworthiness of the system.  相似文献   

14.
Respective roles of short-and long-range interactions in protein folding   总被引:2,自引:0,他引:2  
A new method was presented to discuss the respective roles of short- and long-range interactions in protein folding. It‘s based on an off-lattice model, which is also being called as toy model. Simulated annealing algorithm was used to search its native conformation. When it is applied to analysis proteins lagt and laho, we find that helical segment catmot fold into native conformation without the influence of long-range interactions. That‘s to say that long-range interactions are the main determinants in protein folding.  相似文献   

15.
Caching is an important technique to enhance the efficiency of query processing. Unfortunately, traditional caching mechanisms are not efficient for deep Web because of storage space and dynamic maintenance limitations. In this paper, we present on providing a cache mechanism based on Top-K data source (KDS-CM) instead of result records for deep Web query. By integrating techniques from IR and Top-K, a data reorganization strategy is presented to model KDS-CM. Also some measures about cache management and optimization are proposed to improve the performances of cache effectively. Experimental results show the benefits of KDS-CM in execution cost and dynamic maintenance when compared with various alternate strategies.  相似文献   

16.
Orientl: A strategy of Web information integration   总被引:1,自引:1,他引:0  
We propose the OrientI approach for effectively building flexible applications on information integration. The system presents a fully visual development environment tobuild applications. With Orient I system, a user only needs to concentrate on the composition of components for building the InterPlan. and the detailed underlying operations and data streams are invisible to the user. A prototype system has been implemented and has partially proved the convenience hrought by the Orient] approach.  相似文献   

17.
To alleviate the scalability problem caused by the increasing Web using and changing users' interests, this paper presents a novel Web Usage Mining algorithm-Incremental Web Usage Mining algorithm based on Active Ant Colony Clustering. Firstly, an active movement strategy about direction selection and speed, different with the positive strategy employed by other Ant Colony Clustering algorithms, is proposed to construct an Active Ant Colony Clustering algorithm, which avoid the idle and "flying over the plane" moving phenomenon, effectively improve the quality and speed of clustering on large dataset. Then a mechanism of decomposing clusters based on above methods is introduced to form new clusters when users' interests change. Empirical studies on a real Web dataset show the active ant colony clustering algorithm has better performance than the previous algorithms, and the incremental approach based on the proposed mechanism can efficiently implement incremental Web usage mining.  相似文献   

18.
A vision based query interface annotation meth od is used to relate attributes and form elements in form based web query interfaces, this method can reach accuracy of 82%. And a user participation method is used to tune the result; user can answer "yes" or "no" for existing annotations, or manually annotate form elements. Mass feedback is added to the annotation algorithm to produce more accurate result. By this approach, query interface annotation can reach a perfect accuracy.  相似文献   

19.
Many practical problems in commerce and industry involve finding the best way to allocate scarce resources a-mong competing activities. This paper focuses on the problem of integer programming, and describes an evolutionary soft a-gent model to solve it. In proposed model, agent is composed of three components: goal, environment and behavior. Experimental shows the model has the characters of parallel computing and goal driving. Foundation item: Supported by the National Natural Science Foundation of China( 60205007) , Natural Science Foundation of Guangdong Province(001264), Research Foundation of Software Technology Key Laboratory in Guangdong Province and Research Foundation of State Key Laboratory for Novel Software Technology at Nanjing University Biography: Yin Jian ( 1968-), male, Associate professor, research direction: artificial intelligence, data mining.  相似文献   

20.
Content-based filtering E-commerce recommender system was discussed fully in this paper. Users' unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products informa tion, the recommender lists were obtained. Since the system can adapt to the users' feedback automatically, its performance were enhanced comprehensively. Finally the evaluation of the system and the experimental results were presented.  相似文献   

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