Sai Ho Kwok

Bio: Sai Ho Kwok is an academic researcher from Hong Kong University of Science and Technology. The author has contributed to research in topics: Digital watermarking & Digital rights management. The author has an hindex of 15, co-authored 48 publications receiving 1118 citations. Previous affiliations of Sai Ho Kwok include Hong Kong Polytechnic University & California State University, Long Beach.

Attitude towards Knowledge Sharing Behavior

Abstract: Based on the theory of reasoned action, this study is focused on an individual's behavior of knowledge sharing with respect to information systems/information technology (IS/IT) by investigating their attitude towards knowledge sharing. Three variables, namely extrinsic motivation, absorptive capacity and channel richness, were examined as influential factors affecting people's attitude towards knowledge sharing. A structural survey was conducted to test the relationships between attitude and the three variables. The results show that extrinsic motivation imposed no impact on an individual's attitude towards knowledge sharing while the other two factors played a significant part. The results are consistent with the psychological theories and we showed the applicability of the theories in the case of knowledge sharing.

The attraction of personalized service for users in mobile commerce: an empirical study

Abstract: There has been a notable increase in consumer use of mobile applications. Consumers begin to adopt mobile commerce applications. In response, firms have been investing billions of dollars in order to enhance the hardware and software platforms for mobile commerce. Consequently, with such large investments, firms are highly motivated to attract new clients and retain their old customers. In the present study, the strategic parameters have been studied in order to determine the ways in which mobile service providers acquire new customers. For the purpose of analysis, the dependent variable is the service subscribers' intention to switch to a new service provider with personalized services. Four main constructs have been studied - the amount and the perceived usefulness of general advertisements, the perceived usefulness and privacy issues about personalized advertisements. This empirical study indicates that all four constructs are significant in affecting the decision by subscribers to change to a new mobile service provider.

Interoperability of peer-to-peer file sharing protocols

Abstract: Peer-to-Peer (P2P) file sharing software has brought a hot discussion on P2P file sharing among all businesses. Freenet, Gnutella, and Napster are the three most popular P2P file sharing applications. They use three distinct protocols and these protocols come with different characteristics. In this paper, we discuss the protocols of these P2P file sharing applications, in terms of the methodologies used for peer registry, query and content sharing. In order to maximize the benefit of P2P file sharing application that is to facilitate file sharing among various P2P file sharing applications, we propose a framework to integrate various P2P file sharing protocols using P2P gateway in this paper.

Participation incentive mechanisms in peer-to-peer subscription systems

Abstract: Businesses are trying to explore new business opportunities in the newly emerging P2P technology applications. Motivating peer members through incentive mechanisms to supply contributions to the system and controlling free riding are suggested in this paper as important success factors for developing P2P-based business models. We review the psychology and community behavior literature in order to provide an explanation for the reasons why people get motivated to participate in P2P systems and to contribute to the peer community. Motivation can be classified into individual factors and interpersonal factors. Based on these factors, we develop incentive mechanisms that may help to induce peers to contribute and participate more and thus benefit the entire P2P system and community. In particular, we propose the inclusion of the following four features into P2P application environments: (i) contribution-reward mechanism, (ii) individual identity and profile generation, (iii) sub-community building, and (iv) peer recommendations.

Efficient gamut clipping for color image processing using LHS and YIQ

Abstract: Out-of-gamut problems exist in color image processing and color reproduction in different devices. Extensive research has been done on transforming out-of-gamut colors to the inside of the output device's color gamut for color reproduction. We focus on the out-of- gamut problem in color image processing. Luminance, hue, and satura- tion (LHS) and YIQ color coordinate systems are investigated. Efficient techniques for luminance and saturation processing and gamut clippings are presented. The efficient technique of luminance clipping for LHS is developed based on scaling, and the efficient technique of luminance clipping for YIQ is developed based on shifting. However, the efficient technique of saturation clipping for both LHS and YIQ is a combination of scaling and shifting. Such efficient techniques reduce the complexity of forward and backward transformations between the color representing the color coordinate system (RGB) and the processing color coordinate system (LHS or YIQ) significantly. Illustrations show the result of RGB, luminance, and saturation clippings. Saturation clipping is the best in terms of maintaining the hue and contrast of the original image. Experi- ments are also conducted to measure the efficiency of the proposed efficient techniques. It shows that the processing time is reduced by 27% comparing with the conventional technique using forward and backward color transformations. © 2003 Society of Photo-Optical Instrumentation Engineers.

FSIM: A Feature Similarity Index for Image Quality Assessment

Abstract: Image quality assessment (IQA) aims to use computational models to measure the image quality consistently with subjective evaluations. The well-known structural similarity index brings IQA from pixel- to structure-based stage. In this paper, a novel feature similarity (FSIM) index for full reference IQA is proposed based on the fact that human visual system (HVS) understands an image mainly according to its low-level features. Specifically, the phase congruency (PC), which is a dimensionless measure of the significance of a local structure, is used as the primary feature in FSIM. Considering that PC is contrast invariant while the contrast information does affect HVS' perception of image quality, the image gradient magnitude (GM) is employed as the secondary feature in FSIM. PC and GM play complementary roles in characterizing the image local quality. After obtaining the local quality map, we use PC again as a weighting function to derive a single quality score. Extensive experiments performed on six benchmark IQA databases demonstrate that FSIM can achieve much higher consistency with the subjective evaluations than state-of-the-art IQA metrics.

Knowledge sharing: A review and directions for future research

Abstract: The success of knowledge management initiatives depends on knowledge sharing. This paper reviews qualitative and quantitative studies of individual-level knowledge sharing. Based on the literature review we developed a framework for understanding knowledge sharing research. The framework identifies five areas of emphasis of knowledge sharing research: organizational context, interpersonal and team characteristics, cultural characteristics, individual characteristics, and motivational factors. For each emphasis area the paper discusses the theoretical frameworks used and summarizes the empirical research results. The paper concludes with a discussion of emerging issues, new research directions, and practical implications of knowledge sharing research.

File system shell

Abstract: A file system shell is provided. One aspect of the shell provides virtual folders which expose regular files and folders to users in different views based on their metadata instead of the actual physical underlying file system structure on the disk. Users are able to work with the virtual folders through direct manipulation (e.g., clicking and dragging, copying, pasting, etc.). Filters are provided for narrowing down sets of items. Quick links are provided which can be clicked on to generate useful views of the sets of items. Libraries are provided which consist of large groups of usable types of items that can be associated together, along with functions and tools related to the items. A virtual address bar is provided which comprises a plurality of segments, each segment corresponding to a filter for selecting content. A shell browser is provided with which users can readily identify an item based on the metadata associated with that item. An object previewer in a shell browser is provided which is configured to display a plurality of items representing multiple item types.