Abstract To effectively manage the proliferating online content, it is imperative that we come up with efficient data structuring and organization methods. Based on the findings of previous research [6] [7] that the most flexible and useful way to organize the online content is via the use of taxonomies and/or ontologies, we carried out the present study, which aims at structuring... To effectively manage the proliferating online content, it is imperative that we come up with efficient data structuring and organization methods. Based on the findings of previous research [6] [7] that the most flexible and useful way to organize the online content is via the use of taxonomies and/or ontologies, we carried out the present study, which aims at structuring the content of the Greek Wikipedia via the use of the Greek WordNet. In particular, our study objective is to design a model that can automatically organize the Greek Wikipedia categories into a thematic taxonomy and based on the derived organization, to implicitly assign hierarchical structure to the encyclopedia articles that have been classified to the respective categories. To this end, we relied on the data encoded in Greek WordNet out of which we harvested the hierarchical relations that hold between the terms used to verbalize the Wikipedia categories. The effectiveness of our model is verified by the findings of several experimental evaluations conducted, which demonstrate that semantic networks are powerful resources for hierarchically organizing large volumes of dynamic data. Read More Read Less

Abstract The model of normal students work placement has been a significant measure for the reform of teacher's education and with the development of distant education theory; thus the education model of networked learning activities arouses major concern. On the basis of new horizons of learning support service in this paper, it will start from three aspects which are the model... The model of normal students work placement has been a significant measure for the reform of teacher's education and with the development of distant education theory; thus the education model of networked learning activities arouses major concern. On the basis of new horizons of learning support service in this paper, it will start from three aspects which are the model of learning support service, the design of learning support service system and the application of learning support service accomplished in Work placement to provide an new and effective interactive model to normal students’ work placement activities. Read More Read Less

Abstract Two diagrams are most commonly used in System Dynamics (SD); Causal Loop Diagrams (CLDs) and Stock and Flow Diagrams (SFDs). CLDs are qualitative in nature while SFDs are quantitative. In this paper we draw our attention to CLDs. CLDs are visual representation of dynamic influences with inter-relationships amongst a collection of SD variables. They are used to qualitatively capture structures... Two diagrams are most commonly used in System Dynamics (SD); Causal Loop Diagrams (CLDs) and Stock and Flow Diagrams (SFDs). CLDs are qualitative in nature while SFDs are quantitative. In this paper we draw our attention to CLDs. CLDs are visual representation of dynamic influences with inter-relationships amongst a collection of SD variables. They are used to qualitatively capture structures and interactions of feedback loops. CLDs however, have been found to be ambiguous, lack detail and not easy to conceptualize. In this paper therefore, we come up with steps on how to transfer information from a CLD into an Object Role Modeling (ORM) model. We carry out this study to improve CLD model conceptualization, make CLD variables explicit and to reduce on CLD model ambiguity. To achieve this we use ORM, a fact oriented method whose focus is on domain conceptualization through data modeling because of its conceptual focus and roots in verbalization, graphical expressiveness and well defined semantics. To apply and validate these steps, we use a case as an example in focus session setting. From these focus sessions, evaluations and discussion of results are made and finally conclusions are drawn. Read More Read Less

Abstract A study of online signature verification has been carried out based on experimental evaluation. We started by presenting a brief survey of the recent literatures on important factors of online signature verification. Four main issues have been addressed in the work: 1) assessment for signature consistency caused by different physiological factor. 2) Analysis for variation and complexity of online signature.... A study of online signature verification has been carried out based on experimental evaluation. We started by presenting a brief survey of the recent literatures on important factors of online signature verification. Four main issues have been addressed in the work: 1) assessment for signature consistency caused by different physiological factor. 2) Analysis for variation and complexity of online signature. 3) Performance evaluation for features widely used in several datasets. 4) Comparative analysis for algorithms applied on acquired datasets. From detailed experimental analysis, we identified and characterized some important aspects of online signatures. Read More Read Less

Abstract Internet applications have reached such a high complexity that the network stack concept introduced decades ago is not suitable anymore. Future Internet research activities try to increase the flexibility of the Internet in order to allow the network to adapt to present and future requirements and applications. A well known approach is to build protocol graphs, which will be used... Internet applications have reached such a high complexity that the network stack concept introduced decades ago is not suitable anymore. Future Internet research activities try to increase the flexibility of the Internet in order to allow the network to adapt to present and future requirements and applications. A well known approach is to build protocol graphs, which will be used instead of inflexible network stacks, by connecting functional blocks together. A functional block encapsulates a particular network function. The protocol graph that should be used is the one most suitable to the application's requirements. To find the most suitable graph, all possible protocol graphs must be evaluated. However, the number of possible protocol graphs increases exponentially as the number of functional blocks increases. This article presents a method of modeling the protocol graph search space as a set of search trees and then using search strategies to manage the inherent complexity of the search process. We evaluate our proposed method by simulation. Read More Read Less

Abstract We proposed a novel kernel for text categorization. This kernel is an inner product in the feature space generated by all word combinations of specified length. A word combination is a collection of different words co-occurring in the same sentence. The word combination of length k is weighted by the k-th root of the product of the inverse document frequencies... We proposed a novel kernel for text categorization. This kernel is an inner product in the feature space generated by all word combinations of specified length. A word combination is a collection of different words co-occurring in the same sentence. The word combination of length k is weighted by the k-th root of the product of the inverse document frequencies (IDF) of its words. A computationally simple and efficient algorithm was proposed to calculate this kernel. By restricting the words of a word combination to the same sentence and considering multi-word combinations, the word combination features can capture similarity at a more specific level than single words. By discarding word order, the word combination features are more compatible with the flexibility of natural language and the dimensionality this kernel can be reduced significantly compared to the word-sequence kernel. We conducted a series of experiments on the Reuters-21578 dataset and 20 Newsgroups dataset. This kernel consistently achieves better performance than the classical word kernel and word-sequence kernel on the two datasets. We also assessed the impact of word combination length on performance and compared the computing efficiency of this kernel to those of the word kernel and word-sequence kernel. Read More Read Less