• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.11
• /
• pp.4372-4394
• /
• 2020

The distribution of popular videos incurs a large amount of traffic at the base stations (BS) of networks. Device-to-multi-device (D2MD) communication has emerged an efficient radio access technology for offloading BS traffic in recent years. However, traditional studies have focused on synchronous user requests whereas asynchronous user requests are more common. Hence, offloading BS traffic in case of asynchronous user requests while considering their time-varying characteristics and the quality of experience (QoE) of video request users (VRUs) is a pressing problem. This paper uses social stability (SS) and video loading duration (VLD)-tolerant property to group VRUs and seed users (SUs) to offload BS traffic. We define the average amount of data transmission (AADT) to measure the network's capacity for offloading BS traffic. Based on this, we formulate a time-varying bipartite graph matching optimization problem. We decouple the problem into two subproblems which can be solved separately in terms of time and space. Then, we propose the socially aware D2MD user selection (SA-D2MD-S) algorithm based on finite horizon optimal stopping theory, and propose the SA-D2MD user matching (SA-D2MD-M) algorithm to solve the two subproblems. The results of simulations show that our algorithms outperform prevalent algorithms.

• Journal of Distribution Science
• /
• v.17 no.2
• /
• pp.101-107
• /
• 2019

Purpose - The purpose of this study is to analyze the user requirements and developer requirements in virtual reality(VR), and suggest ways to increase the satisfaction of users who experience virtual reality. Specifically, focused on experience store of VR as a distribution retailer, user requirements were analyzed according to the results of previous research that the characteristics of Affordance, Presence, and Head Mounted Display (HMD) affect user satisfaction. Research, design, data, and methodology - Based on previous studies, in this study, we analyzed the importance of immerse, interaction, perception, and presence for the satisfaction of the user through the questionnaire, and the user experiences virtual reality (VR) The importance of HMD, Presence, Affordance, and experience satisfaction were analyzed. Based on this, we analyzed the user requirements and the developer requirements based on the questionnaires and interviews of the experts, starting from the user's desire or preference using QFD technique. Results - As a result of the analysis, the development factors that occupied a big part in the virtual reality field appeared to be visual. In detail, this showed that there was a lack of sense of presence for users. This should be improved. This paper shows that the requirements for visual, auditory, and tactile development are necessary. For the satisfaction of the users of virtual reality (VR) users, it is necessary to develop them according to their priority in consideration of importance and difficulty in the future. Conclusions - In this study, it was suggested that development according to priority should be considered, considering the difficulty level. Based on the results of this study, the following suggestions are made. First, we tried to search the list of user requirements as much as possible, but it is likely to change due to the development of VR technology. Therefore, it is necessary for developers to continually supplement user requirements with recent research literature. Second, development priorities according to difficulty level should be considered. This aspect should be considered in the actual VR development process, so if the numerical value of the difficulty is calculated, it should be presented in the research.

• Asia pacific journal of information systems
• /
• v.29 no.4
• /
• pp.856-874
• /
• 2019

The performance of recommender systems (RS) has been measured mainly in terms of accuracy. However, there are other aspects of performance that are difficult to understand in terms of accuracy, such as coverage, serendipity, and satisfaction with recommended results. Moreover, particularly with RSs that suggest multiple items at a time, such as YouTube, user satisfaction with recommended results may vary not only depending on their accuracy, but also on their configuration, content, and design displayed to the user. This is true when classifying an RS as a single RS with one recommended result and as a multiple RS with diverse results. No empirical analysis has been conducted on the influence of the content and distribution of recommendation items on user satisfaction. In this study, we propose a research model representing the content and distribution of recommended items and how they affect user satisfaction with the RS. We focus on RSs that recommend multiple items. We performed an empirical analysis involving 149 YouTube users. The results suggest that user satisfaction with recommended results is significantly affected according to the HHI (Herfindahl-Hirschman Index). In addition, satisfaction significantly increased when the recommended item on the top of the list was the same category in terms of content that users were currently watching. Particularly when the purpose of using RS is hedonic, not utilitarian, the results showed greater satisfaction when the number of views of the recommended items was evenly distributed. However, other characteristics of selected content, such as view count and playback time, had relatively less impact on satisfaction with recommended items. To the best of our knowledge, this study is the first to show that the category concentration of items impacts user satisfaction on websites recommending diverse items in different categories using a content-based filtering system, such as YouTube. In addition, our use of the HHI index, which has been extensively used in economics research, to show the distributional characteristics of recommended items, is also unique. The HHI for categories of recommended items was useful in explaining user satisfaction.

• Journal of Korean Library and Information Science Society
• /
• v.26
• /
• pp.505-540
• /
• 1997

The library collects relevant documents, organizes these documents, retrieves and provides relevant documents, and helps the user use provided documents. These library activities are the distribution process of relevant documents in a society, and the role of library science is to deal with several problems in this process. This process is to facilitate the production of socially relevant documents, to select documents relevant to an individual user, and to enable the user to use the selected documents. As a result, this process should be based on the concept of "relevance". As a result, the academic role of library science should be considered based on "relevance". "Relevance" is getting more important to meet the change of the environment of library services, which is getting more complex and changing rapidly because of the computer and the computer network. It is true that these are very important tool for document distribution. However, the problems in the document distribution can not be solved only by the simple development of these tools because these have been caused by the simple development of these tools. These problems can be solved only through many studies of the user, which is the destination of document distribution, and through a n.0, pplying the results of these studies to designing these tools.dies to designing these tools.

• Journal of Information Technology Services
• /
• v.11 no.4
• /
• pp.181-194
• /
• 2012

The one of the most meaningful change in the recent ubiquitous environment is the omnipresence of public digital display device for providing ubiquitous information. It is the important issue to provide publicity as well as adaptive information to each user in the field of the public digital display device. This research proposes the idea ensuring fast response speed by the selection of user preference function. The preference function is selected by statistics using Zipf distribution in the system comprising mobile device and digital display device based on NFC (Near Field Communication). The idea is proved by CPM-GOMS model and the improvement of user response can be achieved.

• Journal of Distribution Science
• /
• v.13 no.8
• /
• pp.73-80
• /
• 2015

Purpose - This study's objective is to analyze the content of the communications between users and producers based on the construal level theory. User generated content refers to content created in an online-based service where users and producers communicate interactively with each other. In a user generated content platform, the messages sent and received between the many players, the users and producers who use the content, may be analyzed at the psychological level based on construal level theory. Research design, data, and methodology - This study gathered user and producer participation through a snow-bowling sampling method. The data analyzed includes 125 video clips and 2,912 comments. The period of the data collection was from September 2014 to December 2014. The collected data was analyzed using a t-test and two-way ANOVA. Results - This study obtained the following research results. First, users who were a short social distance from producers responded to user participatory activities stated in concrete language rather than abstract language. In contrast, users who were at a longer social distance from producers tended to respond to the content requesting user participation through abstract language. Second, if users and producers were at a short social distance from each other, user preference increased more when a producer response to user participation was expressed concretely rather than when it was expressed abstractly. In contrast, if the users were at a longer social distance, users' preferences increased more when producer response was expressed abstractly rather than when it was expressed concretely. Conclusion - This study found that the effect of suitability, in which the social distance and the content were in congruence at the construal level, could be observed. Therefore, based on this, academic and practical implications were drawn. The three main insights of the study are as follows. First, firms can use psychological factors to analyze the message content of users in their distribution platforms. This study reveals managerial implications for marketing managers who want to take make use of this analysis of user and producer communications. This study indicates that the main factors include the concrete and abstract scores and social distance between users and producers. Second, we also provide the strategic guidelines to maximizing user preferences and other outcomes. The main dependent variable in this study is the user preference shift; the variable increases through the congruence effect; and the construal level is determined by the social distance between the users and producers and the type of producer response. The outcomes here from users can be utilized to develop several systemic strategies. One process to use the outcomes could be: (1) firms could measure the users and producers social distance; (2) calculate the concreteness or abstractness of the messages; and, (3) predict the user preference outcomes by the congruence between user and producer social distance and the abstractness or concreteness of the message content.

• Journal of Distribution Science
• /
• v.15 no.1
• /
• pp.43-49
• /
• 2017

Purpose - This study is to integrate organizational factors into UCD process. For this research purpose, we investigated the organizational factors which influence people behaviors in the context of user-centred design practice(UCP). And this study presents organizational culture, organizational learning and change management as the organizational factors. Especially, this study is to investigate how change management influences the relationship between the organizational culture/learning and UCD performance. Research design, data, and methodology - Using the survey methodology with a questionnaire, this study distributed the questionnaire to the experienced 112 practitioners of user-centred design practice in 52 Korean small and medium companies. The organizations differed in range and size from medium-scale, which is under 100 of employees, and to small-scale, which is from 100 to 500. Results - Organizational culture and organizational learning have positive effects on user-centred design practice performance as expected. And change management strengthens the positive relationship between organizational learning and user-centred design practice performance but has no effect on the relationship between organizational culture and user-centred design practice performance. Conclusions - This is the first empirical study of investigating and demonstrating some key organizational factors' relationships and UCD performance of an organization, which will support to institutionalize UCD within an organization, providing theoretical foundations.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.41 no.9
• /
• pp.960-972
• /
• 1992

This paper deals with the development of expert system in distribution system which combined with graphic user interface. The proposed expert system can recognize and adjust to the system change, and includes the rule bases of security monitoring. Also it provides load transfer algorithm for efficient load distribution. The graphic user environment for expert system is implemented in the mouse-oriented user interface with overlapped window functions and pull-down menus. Therefore, the developed graphic integrated expert system can afford to assist system operators very conveniently through the various graphic function in proposing an optimal plan of load transfer for fault restoration and outage schedule.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.5 no.2
• /
• pp.177-184
• /
• 2009

The digital contents distribution system via network provides comfortability, usability, and diversified functions to content's users. However, for the characteristic of easy access of digital contents, the copyright infringements and indiscreet contents distribution are realized in this days. In other words, any users with the authentication key can access to copyright contents with any restrictions. To solve this problems, we proposed a user authentication mechanism which prevent indiscreet access to the digital content by using user system information. Also, to provide safe distribution of digital content, we used user's unique content authentication key.

• Journal of Environmental Impact Assessment
• /
• v.15 no.3
• /
• pp.179-191
• /
• 2006

The authors argue that the current Government Information System for asthmatics appears to be non-user friendly due to lack of the cartographic representation for the text based statistical data. Acknowledging these constraints, an operational, user-friendly map for asthmatic prevalence has been generated by combining existing statistical data with the administrative Dong boundary map under GIS environment. The Geographical User Interface, in particular, were ideally suited to deriving the major distribution patterns that more asthmatic prevalence tends to be occurred on conventional commercial district and industrial complex. A visual map using spatial modelling technology were generated to show the fact that some degree of increasing or decreasing trends of asthmatic prevalence already exists in the experimental sites. It could be used as an evidence to restrict initiation of development activities causing negative influence to asthma such as road construction. The result of this study would play a crucial role in improving the quality of environmental health information service if it is operationally introduced into the Government since the highly user-friendly interface provides a completely new means for disseminating information for asthmatics in a visual and interactive manner to the general public.