• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.45-73
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• 2008

Quality has long been considered as an important factor in creating competitive advantage, and researches on quality have not been limited to off-line products but actively extended to e-services and information goods. However, given the nature of multi-dimensional aspect of quality, the systematic study on the quality of online service is still in its early stage. Especially, studies on the quality of ASP services have been rare in academic and professional journals despite the growth of ASP industry in its size and the rapid expansion in the range of application. In this paper we clarified the multi-dimensional quality aspects of the ASP service using a Garvin's framework (1984) which encompasses the service aspects of Products, and developed a measurement model for ASP service qualify. Then we empirically tested the effects of ASP service quality on user satisfaction and perceived firm performance using the data from 240 Korean small firms with less than 50 employees that had experienced the ASP service. Our results show that there are positive relationships among ASP service quality and personal performance, user satisfaction and perceived firm performance, and that product and service-related aspects of ASP service exert differential effects on performance measures so that the product-related aspects of the ASP service such as performance, features, reliability and conformance are considered to be more important in evaluating benefits from ASP services. Contrary to the approaches In literature where only the quality of online services is evaluated, our results emphasize the importance of differentiating Product and service-related aspects of ASP service and provide a basis for more comprehensive evaluation of ASP service quality.

• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.88-101
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• 2011

Locative media is fundamentally different from traditional media in terms of being packed with user's space, place, and position nearby, which does not simply mean user's physical coordinates. This study has been started that I was drawn by the tendency of which current locative media contents are based on 'location-based information,' and closely related with 'Augmented Reality.' I wonder how media user's psychological experience/involvement are revealed when the media environment changes by the progress of technology. I wonder how media users perceive 'social presence' formed by locative media in current locative media environment. Particularly, the fact that user's perception of social presence formed in locative media conflicts with the previous computer-mediated communication(CMC)'s attributes deepened my curiosity. In this study, the idea of 'more-proper-construct' is suggested, the characteristics of social presence in current locative media is considered, and is investigated by qualitative methodology how the 'location-based' attributes and 'AR' contribute to forming the social presence.

• Journal of Internet Computing and Services
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• v.4 no.4
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• pp.53-64
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• 2003

To perform the certificate validation on the user-side application induces the very considerable overhead on the user-side system because of the complex and time-consuming characteristic of the validation processing. Most of the time spend for performing the validation processing is required for the digital signature verification, since the verification accompanies with the cryptographic calculation over each certificate on the certificate path. In this paper, we propose a new certificate validation scheme using DSVP(Delegated Signature Validation Protocol) which can reduce the overhead for the user-side certificate validation processing. It is achieved by delegating the digital signature verification to CAs of the PKI domain. As the proposed DSVP is the protocol performed between a user and CAs, it is applied to the hierarchical PKI efficiently and used for delegating the digital signature verification reliably and safely, our proposed scheme can not only reduces the overhead for the validation processing by decreasing the cryptographic calculation but also improves the utilization of CAs by employing them to the validation processing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.541-550
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• 2014

This paper describes a multi-scale user interaction based tiled display visualization system using multiple input devices for monitoring and analyzing Geostationary Ocean Color Imager (GOCI) observation satellite imagery. This system provides multi-touch screen, Kinect motion sensing, and moblie interface for multiple users to control the satellite imagery either in front of the tiled display screen or far away from a distance to view marine environmental or climate changes around Korean peninsular more effectively. Due to a large amount of memory required for loading high-resolution GOCI satellite images, we employed the multi-level image load technique where the image was divided into small tiled images in order to reduce the load on the system and to be operated smoothly by user manipulation. This system performs the abstraction of common input information from multi-user Kinect motion and gestures, multi-touch points and mobile interaction information to enable a variety of user interactions for any tiled display application. In addition, the unit of time corresponding to the selected date of the satellite images are sequentially displayed on the screen and multiple users can zoom-in/out, move the imagery and select buttons to trigger functions.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.6
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• pp.725-736
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• 2013

This study segments information users according to depth and variety of use diffusion in order to differentiate between the influence of fashion information spread and diffusions from each segmented group. Data were collected from a fashion community to perform a social network analysis that used UCINET 6.0. Members completed the survey materials and the network materials were utilized in the analysis to test the hypothesis. The segmented groups of information users determined the study results according to use diffusion and the variables that affect them. The variables affecting information diffusion outcomes indicate different significant influence factors on each segmented market. Information variety and complexity represents elevated information reproductions and verbal acceptances from information diffusion outcomes.

• The Journal of Information Technology and Database
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• v.3 no.2
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• pp.97-118
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• 1996

Information systems quality engineering is one of the most problematic areas in practice and research, and needs cooperative efforts between practice and theory [Glass, 1996]. A model for evaluating the quality of system development process and ensuing success is proposed based on information processing theory of project unit design. A nomological net among a set of quality variables is identified from prior research in the areas of organization science, software engineering, and management information systems. More specifically, system development success was modelled as a function of project complexity, system development modelling environment, user participation, project unit structure, resource availability, and the level of iterative nature of development methodology. Based on the model developed from the information processing theory of project unit design in organization science. appropriate quality metrics for each variable in the proposed model are matched. In this way, a framework of relevant systems development and success quality metrics for controlling systems development processes and ensuing success is proposed. The causal relationships among the constructs in the proposed model are proposed as future empirical research for academicians and as managerial tools for quality managers. The framework and propositions help quality manager to select more parsimonious quality metrics for controlling information systems development processes and project success in an integrated way. Also this model can be utilized for evaluating software quality assurance programmes, which are developed and marketed by many vendors.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1027-1036
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• 1996

X.500 Directory is an application level protocol in the Open Systems Interconnection(OSI) 7 layer's reference model adopted by the international Standards Organization (ISO). It manages effectively needed information for the communication service, and is a service to support the functions that the user can approach conveniently. Tourist information is distribution on several locations. The access of distributed information is similar to X.500 directory service. Therefore, we design of Tourist Information System(TIS) and directory schema using X.500 directory services. To define tourist information, we also propose Directory Information Tree(DIT) of locality architecture and several new object classes, such as museum, mountain, sea, hotel, etc.

• Annual Conference of KIPS
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• 2009.04a
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• pp.246-249
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• 2009

인간 생활의 편의를 위해 지능형 서비스 로봇에 대한 필요성이 증가하고 있지만, 인간과 로봇이 상호간에 소통할 수 있는 인터페이스나 애플리케이션 등의 개발은 미흡한 상태이다. 이러한 문제점을 극복하고 지능형 서비스 로봇의 대중화를 위하여 사용자 중심의 애플리케이션을 제안한다. 사용자 애플리케이션은 각 시스템들의 정보를 분석하여 제어하는 부분을 담당하고, 사용자의 명령을 블루투스 통신을 통해 로봇에게 전달하며, 로봇의 위치데이터 및 영상정보를 사용자에게 보여준다. 제안 시스템을 통해 로봇에 대한 전문지식이 없는 사용자도 로봇을 쉽게 제어할 수 있으며, 관리자는 원격지에서도 제어 및 모니터링이 가능하여 시스템 관리의 편의성을 제공한다.

• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.107-120
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• 2014

This study proposes a novel recommender system using the structural hole analysis to reflect qualitative and emotional information in recommendation process. Although collaborative filtering (CF) is known as the most popular recommendation algorithm, it has some limitations including scalability and sparsity problems. The scalability problem arises when the volume of users and items become quite large. It means that CF cannot scale up due to large computation time for finding neighbors from the user-item matrix as the number of users and items increases in real-world e-commerce sites. Sparsity is a common problem of most recommender systems due to the fact that users generally evaluate only a small portion of the whole items. In addition, the cold-start problem is the special case of the sparsity problem when users or items newly added to the system with no ratings at all. When the user's preference evaluation data is sparse, two users or items are unlikely to have common ratings, and finally, CF will predict ratings using a very limited number of similar users. Moreover, it may produces biased recommendations because similarity weights may be estimated using only a small portion of rating data. In this study, we suggest a novel limitation of the conventional CF. The limitation is that CF does not consider qualitative and emotional information about users in the recommendation process because it only utilizes user's preference scores of the user-item matrix. To address this novel limitation, this study proposes cluster-indexing CF model with the structural hole analysis for recommendations. In general, the structural hole means a location which connects two separate actors without any redundant connections in the network. The actor who occupies the structural hole can easily access to non-redundant, various and fresh information. Therefore, the actor who occupies the structural hole may be a important person in the focal network and he or she may be the representative person in the focal subgroup in the network. Thus, his or her characteristics may represent the general characteristics of the users in the focal subgroup. In this sense, we can distinguish friends and strangers of the focal user utilizing the structural hole analysis. This study uses the structural hole analysis to select structural holes in subgroups as an initial seeds for a cluster analysis. First, we gather data about users' preference ratings for items and their social network information. For gathering research data, we develop a data collection system. Then, we perform structural hole analysis and find structural holes of social network. Next, we use these structural holes as cluster centroids for the clustering algorithm. Finally, this study makes recommendations using CF within user's cluster, and compare the recommendation performances of comparative models. For implementing experiments of the proposed model, we composite the experimental results from two experiments. The first experiment is the structural hole analysis. For the first one, this study employs a software package for the analysis of social network data - UCINET version 6. The second one is for performing modified clustering, and CF using the result of the cluster analysis. We develop an experimental system using VBA (Visual Basic for Application) of Microsoft Excel 2007 for the second one. This study designs to analyzing clustering based on a novel similarity measure - Pearson correlation between user preference rating vectors for the modified clustering experiment. In addition, this study uses 'all-but-one' approach for the CF experiment. In order to validate the effectiveness of our proposed model, we apply three comparative types of CF models to the same dataset. The experimental results show that the proposed model outperforms the other comparative models. In especial, the proposed model significantly performs better than two comparative modes with the cluster analysis from the statistical significance test. However, the difference between the proposed model and the naive model does not have statistical significance.

• Journal of Korea Multimedia Society
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• v.21 no.2
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• pp.232-241
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• 2018

Operational Transformation (OT) algorithms for real-time collaborative editing systems are becoming increasingly important due to the increased demand for collaborative data processing. The operational transformation algorithm is a technique for real-time concurrency control and consistency maintenance with non-locking technique, and many studies have been conducted to overcome three issues of convergence, causality-prevention, and intention-prevention. However, previous work has the disadvantage of wasting memory by storing all operations that occurred during an edit operation in the history buffer to solve this problem. Therefore, we propose a memory-saving real-time collaborative editing system that maintains a constant memory space and concurrency control through a method of applying the valid-time to each user-generated operation in order to reduce memory waste. This system prevents long-term memory occupation of client-generated operations, thus it reduces the space and time complexity even with low-rate of collaboration work, so that the performance degradation avoids.