• Journal of Korea Multimedia Society
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• v.7 no.8
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• pp.1078-1085
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• 2004

The SARLM(Source Adaptive Receiver-Driven Multi-Layered Multicast) has been proposed to address heterogeneous bandwidth constraints through layer merging and splitting. However, this method causes that receivers subscribing to the higher layer drop down to the lower layer and hence may decrease utilization of available bandwidth after layer merging. In this paper, we proposed a multicast regrouping method considering distributive status of receivers according to loss rates. The proposed method weights receivers according to loss rates. And then it groups higher layer with receivers subscribing to lower layer have extra bandwidth and lower layer with receivers subscribing to higher layer have high loss rate. Experimental results show that receivers subscribing to higher layer can receive in high transmission rate and consequently the proposed method effectively improves utilization of available bandwidth.

• Asia pacific journal of information systems
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• v.31 no.3
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• pp.277-295
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• 2021

This paper examines the features that make a YouTube channel attractive to users. Considering that drawing users' attention is challenging on this platform, where voluminous amounts of videos are available, it is crucial to identify the factors that make users intend to subscribe to a YouTube channel. In this study, we used an online survey to collect data from 1125 respondents and an SEM model using Smart PLS 3.2.8 to analyze it. The results show that integrity and familiarity with a YouTube channel are positively correlated with trust in its creator, which leads to subscribing to the YouTube channel; value and accuracy also positively affect intention to subscribe to a YouTube channel via trust in content. This study enriches the field of research about trust in the creator and trust in content.

• Journal of KIISE:Information Networking
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• v.32 no.4
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• pp.525-534
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• 2005

This paper is concerned with the query slipping and its prevention for trajectory-based matchmaking service in wireless sensor networks. The problem happens when a query propagating along a subscribe trajectory moves through a publish trajectory without obtaining desired information, even though two trajectories intersect geometrically. There follows resubmission of the query or initiation of another subscribe trajectory Thus, query slipping results in considerable time delay and in the worst, looping in the trajectory or query flooding the network. We address the problem formally and suggest a solution. First, the area where nodes are distributed is logically partitioned into smaller grids, and a grid-based multicast next-hop selection algorithm is proposed. Our algorithm not only attempts to make the trajectory straight but also considers the nodal density of recipient nodes and the seamless grid-by-grid multicast. We prove that the publishing and subscribing using the algorithm eventually eliminate the possibility of the slipping. It toms out that our algorithm dissipates significantly less power of neighbor nodes, compared to the non grid-based method, as greedy forwarding, and the fixed- sized grid approach, as GAF (Geographical Adaptive Fidelity)

• Journal of the Korean Society for information Management
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• v.21 no.2
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• pp.45-67
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• 2004

The purposes of this study are to compare and analyze the evaluation indicators for selection of journal suggested by scholars and organizations and to prepare theoretical background for the ideal model to meet opposing paradigms of collection management in academic libraries. A web survey method was employed to investigate applications of various selection criteria (27 for printed and 37 for electronic academic Journal) from the top 40 academic libraries in Korea. In addition, data were analysed statistically using factor analysis, t-test, Analysis of Variance(ANOVA), and Spearman's Rank Oder Correlation. The mean ranking for 9 evaluation indicators for printed were as follows: subscribing volumes per departments, degree of use, selection authority, electronic/print bundle, ISI impact factor, Internationality and reputation, costs for subscription, ILL ＆ DDS, space considerations for printed materials. But, 11 evaluation indicators for electronic were as follows : costs for subscription, accessibility, electronic/print bundle, consortia, selection authority, access expandability, subscribing volumes per departments, scholarly features of the university, ISI impact factor, ILL ＆ DDS, internationality and reputations.

• Journal of Information Technology Services
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• v.10 no.3
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• pp.213-236
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• 2011

Mobile devices are widely accepted as a convenient machine which provides computing capability as well we cell phone capability. Because of limited resources on mobile devices, complex applications could not be deployed on the devices. Service-based mobile applications (SMAs) can provide a solution to overcome the limitation by subscribing cloud services. Since SMAs have complex structures than standalone applications, it is challenging to develop high quality SMAs, to manage both services and mobile applications, and to implement automated billing for subscribed services. Therefore, there is a great demand for a platform for super mobile computing, which supports all key activities in managing life cycle of SMAs. In this paper, we present technical aspects of a platform which is under development; Super Mobile Autonomous Reliable plaTform (SMART). We believe that it provides a number of practical features which are essential in supporting life-cycle of SMAs; development, deployment, management, and operation.

• Journal of Korean Library and Information Science Society
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• v.24
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• pp.391-412
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• 1996

This study attempts to developing an organizational model for industrial information service a n.0, pplicable to industrial su n.0, pporting organization in every industrial sectors. An emphasis is placed on the discussion of the a n.0, ppreciation of industrial climate. Raw data is easily accessible, but industry requires judged, evaluated and assessed information. The case of Korea Federation of Textile Industries is used. The proposed industrial information service model consists of the following elements. Managerial information is frequently published, assessing information from a variety of sources and its implications on products development. Technical information is less frequently published, assessing from serials subscribing for industrial su n.0, pporting organization. Online information system could be adopted. Database such as statistics, personnel, industrial premises, exhibition, bibliographic are desirable.

• International Journal of Safety
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• v.7 no.1
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• pp.1-4
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• 2008

Application of the Microsoft robotics studio (MSRS) to the design of a factory safety monitoring robot is presented. Basic structures of the MSRS and the service are introduced. The service is the key building block of the MSRS. Control of the safety monitoring robot is performed using four basic services: 1) the robot service which communicates with the embedded micro-processor and other services, 2) the sensor service that notifies the subscribing services of the change of the sensor value, 3) the motor service which controls the power levels to the motors, 4) the drive service which maneuvers the robot. With built-in capabilities of the MSRS, control of factory safety monitoring robot can be more easily performed.

• Journal of Korea Multimedia Society
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• v.21 no.9
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• pp.1090-1098
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• 2018

MQTT is a lightweight messaging protocol that can be used for low power IoT devices. The MQTT basically uses single MQTT broker to indirectly share message information between publishers and subscribers. This approach has a weakness in regard to traffic overflow, connection fault, security, etc. In this paper, we propose a distributed MQTT broker architecture that solves the problems in single MQTT broker structure. The distributed MQTT broker architecture is expected to support new application services that cannot be supported by a conventional MQTT architecture. We have designed and implemented a distributed MQTT broker architecture based on the RPL protocol that has been widely used for IoT network. The experiment results show that the proposed MQTT broker architecture represents better publishing/subscribing latency and network stability than the conventional MQTT broker architecture.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.675-678
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• 2006

IPTV (Internet Protocol Television) is an efficient system which serves various contents to subscribing consumers by using the IP over a broadband connection. The IPTV services can be multi-channel broadcasting service, VoD, T-Commerce, video conference, on-line game and so on. TV Anytime metadata provides various description tools for TV program contents by which TV program contents can serve more information. In this paper, we mention about the overview and feature of IPTV and TV Anytime metadata, propose the essential functions in the EPG program of IPTV and survey the description tools for the proposed functions in EPG. Finally, we show the authored metadata and the implementation of advanced EPG application.

• Korean Management Science Review
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• v.22 no.2
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• pp.35-49
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• 2005

When new services are introduced, interaction among existing and new services has to be considered. The interaction can be characterized by the substitution or complementary effect among services. This paper analyzes how the interaction among services affects the customers' subscription decision in telecommunication services industry. Based on a face-to-face in-depth survey from a sample of 1,200 respondents, a new wireless internet access service or WiBro is analyzed to identify the substitution/complementary effect in relation to the existing other telecommunication services. Additionally, the important factors explaining both customers' subscription and substitution decisions are identified. The analysis results indicate that males and students are more likely to subscribe WIBro service. Interestingly, family size positively affects the subscription decision. However, heavy users of on-line game are reluctant to subscribe WiBro service. Among the potential WiBro subscribers, the customers who are less satisfied with the existing fixed line broadband internet access service are more likely to stop subscribing the fixed line service, which implies substitution by a new service. We believe that the consideration of the interactions among services is essential to devise a winning strategy for the new services in the highly uncertain telecommunications business environment.