Abstract Hierarchical clustering of text collections is a key problem in document management and retrieval. In partitional hierarchical clustering, which is more efficient than its agglomerative counterpart, the entire collection is split into clusters and the individual clusters are further split until a heuristicallymotivated termination criterion is met. In this paper, we define the BIC-means algorithm, which applies the Bayesian Information... Hierarchical clustering of text collections is a key problem in document management and retrieval. In partitional hierarchical clustering, which is more efficient than its agglomerative counterpart, the entire collection is split into clusters and the individual clusters are further split until a heuristicallymotivated termination criterion is met. In this paper, we define the BIC-means algorithm, which applies the Bayesian Information Criterion (BIC) as a domain independent termination criterion for partitional hierarchical clustering. We evaluate the effectiveness of BIC-means in clustering and retrieval on medical document collections and we propose a dynamic version of the BIC-Means algorithm for adapting an existing clustering solution to document additions. Read More Read Less

Abstract The design process followed to produce traditional applications needs to be enhanced to cope with new context-aware ubiquitous application requirements. With the popularity of ubiquitous computing, context-aware applications become clearly necessary. This new kind of applications allows mobile users to universally access services in respect to any context including his computing environment. Challenges for the design of such applications are... The design process followed to produce traditional applications needs to be enhanced to cope with new context-aware ubiquitous application requirements. With the popularity of ubiquitous computing, context-aware applications become clearly necessary. This new kind of applications allows mobile users to universally access services in respect to any context including his computing environment. Challenges for the design of such applications are to easily define context collection requirements, context analysis and adaptations of the applications due to changes in its environment. To face these issues, we propose, in this article, a generic and extensible way to model context-awareness of any application using the model-driven engineering (MDE) approach. For this purpose, we add a context-awareness aspect to application model views. We illustrate our solution by modeling a context-aware e-commerce application. The addition of a context-awareness aspect, should ease the definition of mobile applications. Furthermore, context-awareness models open the way to automate context-awareness code production. Read More Read Less

Abstract In this paper, a simple image steganography for secure communication is proposed. Our scheme is based on the discrete cosine transformation (DCT) technique. By using DCT, the most significant information of each DCT secret block can be embedded into the non-significant parts of each DCT cover block. To improve the image quality of the cover image, a quantization factor is... In this paper, a simple image steganography for secure communication is proposed. Our scheme is based on the discrete cosine transformation (DCT) technique. By using DCT, the most significant information of each DCT secret block can be embedded into the non-significant parts of each DCT cover block. To improve the image quality of the cover image, a quantization factor is used. According to our experiments, the proposed method outperforms the VQ-Based and the HVSBased image hiding schemes in terms of the image quality of the stego image and the extracted secret image. Read More Read Less

Abstract Computer Security and Forensics is an emerging academic discipline in which there are many challenges facing educational institutions in teaching, from both an educational and technical perspective. The School of Computing in Dublin Institute of Technology offers two Security and Forensic Computing modules, a 4th year BSc (Hons) module and an MSc module. Currently the BSc module requires a practical... Computer Security and Forensics is an emerging academic discipline in which there are many challenges facing educational institutions in teaching, from both an educational and technical perspective. The School of Computing in Dublin Institute of Technology offers two Security and Forensic Computing modules, a 4th year BSc (Hons) module and an MSc module. Currently the BSc module requires a practical section to the course while the MSc module does not require practical work. In order to aid teaching during the next semester, both sets of students will be exposed to a Security and Forensics practical laboratory. This series of research proposes a phased approach to design and establish a suitable overall environment to provide a comprehensive Computer Security and Forensics practical laboratory. The three identifiable components are (1) an isolated networked environment, (2) an exposed repository to be used to demonstrate vulnerabilities and (3) the formation of a Security and Forensics toolkit to be used in conjunction with the isolated network environment and the exposed repository. This first paper, in a series of three, will introduce the reader to the overall research objective. It will then focus on research and development of the first identified component, namely an isolated network environment. Read More Read Less

Abstract A Web-based surveillance system has been developed to observe some intrusion into dangerous and security area. It is designed based on a Linux PC with Web services, Open CV engine, remote monitoring camera, remote controlling sub-server and other facilities. It supports users of mobile phones. Its image understanding facility by Open CV engine gives us information about intruders’ tracks at... A Web-based surveillance system has been developed to observe some intrusion into dangerous and security area. It is designed based on a Linux PC with Web services, Open CV engine, remote monitoring camera, remote controlling sub-server and other facilities. It supports users of mobile phones. Its image understanding facility by Open CV engine gives us information about intruders’ tracks at the monitored places. As the result, it is beneficial that we can exactly know moving direction of intruders. Traffic security is one of the most important problems to be improved for our daily environment. In order to monitor traffic behavior, the surveillance system has been customized and applied to monitor traffic behavior about a specific area. It can acquire data about intruders’ tracks when they go across relatively narrow streets. Such data provide information about suitable place to realize a necessary cross-walk which will comply with silent but real intruder’s requests. Its monitoring function and image processing one are not so excellent but there are significant results for surveillance by means of limited adoption and adjustment. And we can recommend installation of Crosswalk based on intruders’ tracks with image processing function of the surveillance system. It is concluded that our surveillance system is efficient enough to observe a specific place, compute image understanding about it and mine some kind of useful information of intruder’s periodical behaviors. Read More Read Less

Abstract This paper proposes a mutual detection mechanism between spam blogs and words with bipartite graph clustering for filtering spam blogs from updated blog data. Spam blogs are problematic in extracting useful marketing information from the blogosphere; they often appear to be rich sources of information based on individual opinion and social reputation. One characteristic of spam blogs is copied-and-pasted articles... This paper proposes a mutual detection mechanism between spam blogs and words with bipartite graph clustering for filtering spam blogs from updated blog data. Spam blogs are problematic in extracting useful marketing information from the blogosphere; they often appear to be rich sources of information based on individual opinion and social reputation. One characteristic of spam blogs is copied-and-pasted articles based on normal blogs and news articles. Another is multiple postings of the same article to increase the chances of exposure and income from advertising. Because of these characteristics, spam blogs share common words, and such blogs and words can form large spam bi-clusters. This paper explains how to detect spam blogs and spam words with mutual filtering based on such clusters. It reports that the maximum precision, or F-measure, of the filtering is 95%, based on a preliminary experiment with approximately six months’ updated blog data and a more detailed experiment with one day’s data. An advantage of this method for spam blog filtering, as compared to a machine learning approach, is also supported by experiments with SVM. Read More Read Less

Abstract Existing database management systems (DBMS) are complex and less predictable (i.e., the consistency of performance with the increase of functionality and the data growth is not certain). Database researchers acknowledge the need for revisiting DBMS architectures to fulfill the needs of new hardware and application trends. We propose a biologically inspired DBMS architecture called \'\'Cellular DBMS... Existing database management systems (DBMS) are complex and less predictable (i.e., the consistency of performance with the increase of functionality and the data growth is not certain). Database researchers acknowledge the need for revisiting DBMS architectures to fulfill the needs of new hardware and application trends. We propose a biologically inspired DBMS architecture called \'\'Cellular DBMS Read More Read Less

Abstract In this paper, we introduce a conceptual tuplebased model for specification of spatial, temporal and semantic relationships among media segments in a multimedia presentation. A multimedia presentation contains various kinds of multimedia objects such as audio, video, images, text media types and so on. The organization of a presentation is a complex task in that the display order of presentation... In this paper, we introduce a conceptual tuplebased model for specification of spatial, temporal and semantic relationships among media segments in a multimedia presentation. A multimedia presentation contains various kinds of multimedia objects such as audio, video, images, text media types and so on. The organization of a presentation is a complex task in that the display order of presentation content (in time and space) must be specified. The critical decisions for presentation construction include content selection, content organization, and content delivery. Once the decision is made on the organization of the content of the presentation, it must be conveyed to the end user in the correct organizational order and in a timely fashion. Assuming that a set of multimedia segments gets organized into a presentation graph, this conceptual model formalizes a complete presentation using event-points for these segments. Three possible end-user environments of multimedia presentation are considered for presentation playout as (i) the one without any constraint, (ii) another one with a single constraint, and (iii) the third one with multiple constraints (one constraint for each type of multimedia segments in the organized presentation). In accordance with these limitations (i.e., without violating any of the end-user specified constraints), we give three methods for constructed presentations to be presented at the presentation terminal. Read More Read Less