Coupling semantic and statistical techniques for dynamically enriching web ontologies

With the development of the Semantic Web technology, the use of ontologies to store and retrieve information covering several domains has increased. However, very few ontologies are able to cope with the ever-growing need of frequently updated semantic information or specific user requirements in specialized domains. As a result, a critical issue is related to the unavailability of relational information between concepts, also coined missing background knowledge. One solution to address this issue relies on the manual enrichment of ontologies by domain experts which is however a time consuming and costly process, hence the need for dynamic ontology enrichment. In this paper we present an automatic coupled statistical/semantic framework for dynamically enriching large-scale generic ontologies from the World Wide Web. Using the massive amount of information encoded in texts on the Web as a corpus, missing background knowledge can therefore be discovered through a combination of semantic relatedness measures and pattern acquisition techniques and subsequently exploited. The benefits of our approach are: (i) proposing the dynamic enrichment of large-scale generic ontologies with missing background knowledge, and thus, enabling the reuse of such knowledge, (ii) dealing with the issue of costly ontological manual enrichment by domain experts. Experimental results in a precision-based evaluation setting demonstrate the effectiveness of the proposed techniques.     

A secure framework exploiting content guided and automated algorithms for real time video searching

This paper presents an architecture that allows End Users, via the services of Search Engines, to search, in a secure and efficient way, the video content belonging to Content Providers. The search can be accomplished with any searching scheme that the Search Engines wish to provide, as long as certain security constraints are met. However we propose specific algorithms that demonstrate an efficient way to search video data without sacrificing security effectiveness of the system. The search is completed without the End Users or Search Engines needing to purchase the premium content beforehand, and without the Content Providers needing to purchase the search technology. The business motivation of this technique is to assist End Users to purchase content best suiting their requirements—they are offered search results only, not actual content. The objective is to face the problem caused by the current segregation between content ownership and video processing technology ownership. To face this segregation, we present an architecture that guarantees security of Content Provider’s data and Search Engine’s technology and we also present two innovative algorithms that make real time video searching a feasible process. Particularly these algorithms (a) organize video content into a graph based hierarchical structure and (b) perform content guided, non interactive and real time search by exploiting the graph based video structures. The proposed algorithms are incorporated in the presented architecture under the given security constraints. Experimental results and comparisons with conventional techniques are presented to demonstrate the outperformance of the proposed algorithms.

Join-Idle-Queue: A novel load balancing algorithm for dynamically scalable web services

The prevalence of dynamic-content web services, exemplified by search and online social networking, has motivated an increasingly wide web-facing front end. Horizontal scaling in the Cloud is favored for its elasticity, and distributed design of load balancers is highly desirable. Existing algorithms with a centralized design, such as Join-the-Shortest-Queue (JSQ), incur high communication overhead for distributed dispatchers.We propose a novel class of algorithms called Join-Idle-Queue (JIQ) for distributed load balancing in large systems. Unlike algorithms such as Power-of-Two, the JIQ algorithm incurs no communication overhead between the dispatchers and processors at job arrivals. We analyze the JIQ algorithm in the large system limit and find that it effectively results in a reduced system load, which produces 30-fold reduction in queueing overhead compared to Power-of-Two at medium to high load. An extension of the basic JIQ algorithm deals with very high loads using only local information of server load.     

基于元数据和Web Service中间件的分布式资源库集成

在分析我国教育资源库建设现状的基础之上,提出了一种基于教育资源元数据集中统一管理的,采用WebService中间件实现的分布式异构资源库集成方案,并结合分布式教育资源库之间的连接和互操作的实际情况为Web Service中间件设计了9个功能模块及各个模块的工作模式.该方案能够解决异构教育资源库中教育资源的共享问题,可重复利用当前已经建设好的教育资源库,保护已有投资,同时也为用户提供了一个透明的,一站式的访问环境.     

Towards an ontology based framework for searching multimedia contents on the web

Multimedia Tools and Applications - We live in a world where there are huge number of consumers and producers of multimedia content. In this sea of information, finding the right content is like...     

Cultural heritage metadata aggregation using web technologies: IIIF,Sitemaps and Schema.org

In the World Wide Web, a very large number of resources are made available through digital libraries. We (Europeana and data providers) report on case studies that tested the application of some of the most promising Web technologies, exploring several solutions based on the International Image Interoperability Framework (IIIF) and Sitemaps. We also describe an analysis of the Schema.org vocabulary for application in the context of cultural heritage and metadata aggregation. The solutions were tested successfully and leveraged on existing technology and knowledge in cultural heritage, with low implementation barriers. The future challenges lie in choosing among the several possibilities and standardizing solution(s). Europeana will proceed with recommendations for its network and is actively working within the IIIF community to achieve this goal.     

Eighth graders’ web searching strategies and outcomes: The role of task types,web experiences and epistemological beliefs

This study reported an investigation of eighth graders’ (14-year-olds) web searching strategies and outcomes, and then analyzed their correlations with students’ web experiences, epistemological beliefs, and the nature of searching tasks. Eighty-seven eighth graders were asked to fill out a questionnaire for probing epistemological beliefs (from positivist to constructivist-oriented views) and finished three different types of searching tasks. Their searching process was recorded by screen capture software and answers were reviewed by two expert teachers based on their accuracy, richness and soundness. Five quantitative indicators were used to assess students’ searching strategies: number of keywords, visited pages, maximum depth of exploration, refinement of keyword, and number of words used in the first keyword. The main findings derived from this study suggested that, students with richer web experiences could find more correct answers in “close-ended” search tasks. In addition, students with better metacognitive skills such as keyword refinement tended to achieve more successful searching outcomes in such tasks. However, in “open-ended” tasks, where questions were less certain and answers were more elaborated, students who had more advanced epistemological beliefs, concurring with a constructivist view, had better searching outcomes in terms of their soundness and richness. This study has concluded that epistemological beliefs play an influential role in open-ended Internet learning environments.     

Multiple perspective interactive search: a paradigm for exploratory search and information retrieval on the web

The World Wide Web (WWW) represents the largest and arguably the most complex repository of content at our current state of technological development. Information on the web is represented using a variety of media, with a (current) predominance of text- and images-based data and increasing presence of other media such as video and audio. The complexity and heterogeneity of the information implies that the associated semantics is often user-dependent and emergent. Thus, there is a need to develop novel paradigms for web-based user-data interactions that emphasize user context and interactivity with the goal of facilitating exploration, interpretation, retrieval, and assimilation of information. This article presents a novel presentation-interaction paradigm for exploratory web search which allows simultaneous and semantically correlated presentation of query results from different semantic perspectives. Users can explore the results either using a specific perspective or through a combination of perspectives via highly-intuitive yet powerful interaction operators. In the proposed paradigm, hits obtained from executing a query are first analyzed to determine latent content-based correlations between the pages. Next, the pages are analyzed to extract different types of perceptual and informational cues. This information is used to organize and present the results through an interactive and reflective user interface which supports both exploration and search. Experimental investigations, many of which are conducted in comparative settings, analyze the proposed approach in query-retrieval scenarios involving complex information goals. These results demonstrate the efficacy of the proposed approach and provide important insights for the development of the next-generation of interfaces for web-search.     

On searching for an optimal threshold for morphological image segmentation

Segmentation of images represents the first step in many of the tasks that pattern recognition or computer vision has to deal with. Therefore, the main goal of our paper is to describe a new method for image segmentation, taking into account some Mathematical Morphology operations and an adaptively updated threshold, what we call Morphological Gradient Threshold, to obtain the optimal segmentation. The key factor in our work is the calculation of the distance between the segmented image and the ideal segmentation. Experimental results show that the optimal threshold is obtained when the Morphological Gradient Threshold is around the 70% of the maximum value of the gradient. This threshold could be computed, for any new image captured by the vision system, using a properly designed binary metrics.     

On searching for the active sites in proteins and peptide hormones

An essential part of structure-functional studies of proteins is the search for sites responsible for specific functional activity. The information theory can be of much help in such a search. According to this theory, rarely occurring oligomers contain more information and thus are more likely to take part in forming the active site. We used frequencies of occurrences of amino acids (mean and for each polypeptide) to search for clusters of highly informative amino acids by the moving window smoothing method. In 16 out of 19 peptide hormones such sequences were active sites known from literature.     

The effect of experience and socio-economic status on web searching performance: a South African perspective

The digital divide can be described in terms of two dimensions: access and usage. Many statistics exist to prove the existence of the gap with regard to access to information and communication technology, and specifically the Internet, in South Africa. In this study, the focus was on users' aptitude in searching for information on the World Wide Web once access had been obtained. It was found that experience of 20 browser sessions is not adequate to ensure that learners from lower socio-economic communities improve in their ability to obtain the correct information during web searches but learners from higher socio-economic communities may, depending on the level of difficulty of the task and the phase of search, benefit from this amount of experience. Web experience has no effect on users' efficiency in terms of the number of mouse clicks made although socio-economic status (SES) is a significant predictor of efficiency for users with no or limited experience. Although low-SES users make fewer clicks en route to an answer as they gain experience, it does not necessarily mean that they perform better in obtaining the correct information.     

On the query refinement in the ontology-based searching for information

One of the main problems in the (web) information retrieval is the ambiguity of users’ queries, since they tend to post very short queries which do not express their information need clearly. This seems to be valid for the ontology-based information retrieval in which the domain ontology is used as the backbone of the searching process. In this paper, we present a novel approach for determining possible refinements of an ontology-based query. The approach is based on measuring the ambiguity of a query with respect to the original user's information need. We defined several types of the ambiguities concerning the structure of the underlying ontology and the content of the information repository. These ambiguities are interpreted regarding the user's information need, which we infer from the user's behaviour in searching process. Finally, the ranked list of the potentially useful refinements of her query is provided to the user. We present a small evaluation study that shows the advantages of the proposed approach.     

On exploiting ‘negative’ sensor evidence for target tracking and sensor data fusion

In various applications of target tracking and sensor data fusion all available information related to the sensor systems used and the underlying scenario should be exploited for improving the tracking/fusion results. Besides the individual sensor measurements themselves, this in particular includes the use of more refined models for describing the sensor performance. By incorporating this type of background information into the processing chain, it is possible to exploit ‘negative’ sensor evidence. The notion of ‘negative’ sensor evidence covers the conclusions to be drawn from expected but actually missing sensor measurements for improving the position or velocity estimates of targets under track. Even a failed attempt to detect a target is a useful sensor output, which can be exploited by appropriate sensor models providing background information. The basic idea is illustrated by selected examples taken from more advanced tracking and sensor data fusion applications such as group target tracking, tracking with agile beam radar, ground moving target tracking, or tracking under jamming conditions.     

On the analysis of reputation for agent-based web services

Maintaining sound reputation requires robust control and investigation. In this paper, we analyze a reputation mechanism that objectively maintains accurate reputation evaluation of selfish agent-based web services. In the proposed framework, web services are ranked using their reputation as a result of provided feedback reflecting consumers’ satisfaction. However, selfish web services may alter their public reputation level by managing to get fake feedback. We investigate the payoffs of different scenarios by focusing on the issues that discourage web services to act maliciously. We also analyze the details of the proposed mechanism by discussing simulation and empirical results that fully depict the system parameters and show the feasibility of the proposed approach.     

藏文Web应用的质量模糊综合评判

为给藏文Web应用提供一种定量的质量评判方法,将模糊数学中的模糊综合评判方法应用于对Web中藏文文字的规范呈现、藏文Web中的功能特性、效率和易用性等因素进行综合评价,提出了数学模型和评判方法,同时说明在模糊综合评判中权重至关重要,并且给出了权重的确定方法.最后通过实例说明这种方法在藏文Web评判中的应用中是有效和可行的.     

Creating domain specific metadata for scientific data and knowledgebases

The authors examine a particular type of domain-based metadata for which a complete ready-made conceptual framework is not and probably cannot be directly supported in predefined data models of knowledge-based representation paradigms. The data or knowledge base designer thus has the burden of sometimes working outside a familiar and otherwise appropriate model. The authors discuss issues arising in formulating certain domain-based metadata extensions and provide guidelines for developing them. These results derive from a continuing effort to create a knowledge base to support research on biological organisms. The added semantics are used to support a more flexible and reliable system for identification