7668661
Evaluation on security and privacy of Web-based learning systems
Web-based learning systems are becoming popular in the recent years. Many courses and lectures are now conducted online. Similar to other Web-based applications, security and privacy of Web-based learning systems should not be overlooked. We evaluate the security and privacy of general Web-based learning systems. We address the security and privacy requirements specific to them. Recommendations on design and implementation of a secure Web-based learning system are also presented. In particular, we have evaluated the security services of two popular Web-based learning tools.
35179919
WebQuest Markup Language (WQML) for Sharable Inquiry-Based Learning
WebQuest is a model for constructivist inquiry-based learning in which the information used by learners is collected from the Web. A WebQuest exists in form of a Web site that contains a defined set of componential Web pages. In this paper, we specify the WebQuest Markup Language (WQML) for WebQuest construction. WQML enables WebQuests to be implemented as sharable courseware objects and thus to be interoperable with most learning management systems (LMS).
3206603
BGN Authentication and Its Extension to Convey Message Commitments
We instantiate the cryptosystem proposed by Boneh, Goh, and Nissim in TCC'05 [5] into an entity authentication scheme, in which an entity is authenticated by an interactive zero-knowledge proof on its private key. Completeness and soundness of our scheme is supported by the indistinguishability of BGN ciphertexts of sums and products, which essentially relies on the semantic security of the BGN cryptosystem. We further extend our scheme so that the authentication conveys Pedersen commitments on a message, while the BGN authentication serves the ‘proving you know how to open' functionality for the commitment. Our message commitment scheme is both statistically hiding and computationally binding provided the subgroup decision problem is hard.
28992997
Creating reusable WebQuest objects with WebQuest authoring engine
WebQuest is a constructivist lesson format for Web-enabled inquiry-based learning. A WebQuest exists in form of a Web site that contains a collection of Web pages. In this paper, we define the "WebQuest Object" which is basically a learning object. We also present the WebQuest authoring engine which enables one to generate WebQuest objects without the knowledge in Web page construction and publishing. The WebQuest authoring engine also allows ones to edit the metadata of the WebQuest so as to facilitate the reuse of the WebQuest objects.
9759416
Mobile learning: a new paradigm in electronic learning
As mobile phones become popular, with many people being able to afford them, the demand for mobility is extended to teaching and learning purposes. One recent and significant change in learning environments is the demand for mobility. We introduce a proposed framework of mobile learning. It consists of four functional levels: (1) mobile learning applications, (2) mobile user infrastructure, (3) mobile protocol and (4) mobile network infrastructure. The framework can simplify the design and development so that different parties (e.g. vendors, service providers, designers, developers) can address individual levels. A single party can build on functionalities provided by others. The functions of these four levels are described with some examples. Moreover, practical knowledge management and learning community are two major issues in mobile learning.
894881
Performance improvement of TCP Vegas over heterogeneous networks
Current IP network has become the dominant paradigm for all networking environments. The significant cause of packet losses in such heterogenous networks is no longer limited to network congestion. Traditional TCP interprets every packet loss as caused by congestion which may be not the case in the current Internet. Misinterpretation of wireless random loss as an indication of network congestion results in TCP slowing down its sending rate unnecessarily. We propose a new variant of TCP Vegas named RedVegas. By using the innate nature of Vegas and congestion indications marked by routers, RedVegas may detect random packet losses precisely. Through the packet loss differentiation, RedVegas reacts appropriately to the losses, and therefore the throughput of connection over heterogeneous networks can be significantly improved.
6180081
New adaptive partial distortion search using clustered pixel matching error characteristic
The partial distortion search is a particularly attractive fast block-matching algorithm, because it introduces no prediction error as compared with the full-search algorithm. It reduces the number of necessary matching evaluations for every searching point to save computation. In the literature, many researches have tried to improve block-matching algorithms by making use of an assumption that pixels with larger gradient magnitudes have larger matching errors on average. Based on a simple analysis, we have found that on average, pixel matching errors with similar magnitudes tend to appear in clusters for natural video sequences. By using this clustering characteristic, we propose an adaptive partial distortion search algorithm which significantly improves the computational efficiency of the original PDS. This approach is much better than other pixel gradient based adaptive PDS algorithms. In addition, our proposed algorithm is suitable for motion estimation of both opaque and boundary macroblocks of an arbitrary shaped object in MPEG-4 coding.
841469
Variable temporal-length 3-D discrete cosine transform coding
Three-dimensional discrete cosine transform (3-D DCT) coding has the advantage of reducing the interframe redundancy among a number of consecutive frames, while the motion compensation technique can only reduce the redundancy of at most two frames. However, the performance of the 3-D DCT coding will be degraded for complex scenes with a greater amount of motion. This paper presents a 3-D DCT coding with a variable temporal length that is determined by the scene change detector. Our idea is to let the motion activity in each block be very low, while the efficiency of the 3-D DCT coding could be increased. Experimental results show that this technique is indeed very efficient. The present approach has substantial improvement over the conventional fixed-length 3-D DCT coding and is also better than that of the Moving Picture Expert Group (MPEG) coding.
11665411
Investigating Information Systems Strategic Alignment
Although strategic alignment is an important theoretical concept, and achieving alignment or fit among organizational elements would seem to be an important business objective, empirical demonstrations of the importance of alignment have been uncommon (White 1986). This study attempted to provide an empirical assessment of the nature and importance of information systems strategic alignlnent There is much discussion today about the importance of 1. THE CONCEPTUAL MODEL strategic alignment in general (e.g., Venkatraman and Camillus 1984; White 1986) and information systems (IS) The conceptual model underlying the study is depicted in strategic alignment in particular (e.g., Elam et al. 1988; Figure 1. It depicts the propositions that IS.strategic Henderson and Thomas 1992; Henderson and Venkatraman 1992; Keen 1991; Ward, Griffiths and Whitmore 1990). alignment, defined as the fit existing between business The discussion generally suggests that the better the alignstrategy and IS strategy, impacts performance at the IS ment, the better the expected company performance. level and at the overall business level. However, there have been few empirical verifications of this proposition (White 1986). In addition, the discussion The results of the overall study, and detailed descriptions of about alignment has tended to be imprecise and vague (Van the instruments used to measure business strategy, IS de Ven and Drazin 1985). Important objectives of this strategy, IS effectiveness and business performance, have study were to identify a useful, precise model for the IS been described in Chan et al. (1993) and Chan and Huff strategic alignment construct and to examine empirically (1992) respectively. (Table 1 provides a brief outline of relationships among IS strategic alignment; IS effectiveness, the overall study.) This paper discusses the derivation and and business performance. significance of the IS strategic alignment computations and The discussion opens with a brief overview of the concepthe study's findings regarding alignment tual model underlying this study. Next, instruments that measure business strategy and IS strategy are introduced. Then instruments that measure IS effectiveness and business performance are outlined. This is followed by a 2. MEASURING BUSINESS STRATEGY AND general discussion of various approaches that are used to INFORMATION SYSTEMS STRATEGY assess alignment. Specific models of alignment are evaluated and the primary model for IS strategic alignment used within this research is selected and described. The links In order to assess IS strategic alignment, there needed to be between IS strategic alignment and performance are then assessments of both business strategy and IS strategy. discussed. Finally, the paper concludes with a description Table 2 lists the dimensions of these constructs as operaof the study's implications for management and future tionalized in this study. Multiple indicators were used to research. measure each dimension.
18442431
Understanding the Balanced Effects of Belief and Feeling on Information Systems Continuance
There are innumerable studies on technology adoption as well as continuance of usage. A review of previous research shows that cognitive factors are considered prominently in information technology adoption and continuance while the affective feelings of users are not. Although attitude and user satisfaction are common factors considered in information systems research, these factors only involve partial aspects of feelings. Researchers in the marketing areas, as well as the psychology area, begin to note the importance of feelings in understanding and predicting human and customer behavior. In many modern applications, such as mobile Internet services, user feelings are expected to be important, since users are not just technology users but also service consumers. Drawing upon the support of consumer research, social psychology, and computer science, this study proposes a balanced belief–feeling model of IS continuance. In the process of developing this model, the concepts of attitude, belief, and feelings are further articulated, defined, and distinguished. The balanced model is tested in a survey of mobile Internet users. The results established the validity of the model. A comparison with the IS continuance model shows that the new model can explain significantly more variance in continuance intention, taking into account that the new model has more factors. We offer theoretical reasoning for the balanced effects of belief and feeling on IS continuance and discuss the theoretical and practical implications of this study.