• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.2-4
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• 2018

Most people cause disputes not to do things they do not want to do. Therefore, in this study, the mobile roulette system was studied to make role sharing easy and fun. The role sharing method is to rotate the roulette through the mobile application installed on the smartphone and throw the dart to check the result with the mobile application. Through this study, it is possible to set the role sharing that most people do not like to be as fun as the game, and the conflict due to the role sharing between family members can be reduced. It is also expected that it will contribute to leisure activities, not just unconditional roles.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.228-239
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• 2013

Peer-to-peer (P2P) systems have proved the most effective and popular file sharing applications in recent years. Previous studies mainly focused on equal service and differentiated service strategies when peers have no initial data before their downloads. For an upload-constrained P2P file sharing system, we model both the equal service process and the differentiated service process when the initial data distribution of peers satisfies some special conditions. Moreover, we show how to minimize the time required to distribute the file to any number of peers. The proposed fluid-based models can reveal the intrinsic relations among the initial data amount, the peer set size, and the minimum last finish time. The closed-form expressions derived from the extended models can closely approximate chunk-based models and systems, especially for relatively large files. As an application of the extended models, we show how to provide differentiated service efficiently to multiple peer sets. Since no limits are imposed on the upload bandwidth of peers or the size of each peer set, we believe that our analytic process and the results achieved can provide not only fundamental insights into bandwidth allocation and data scheduling but also a helpful reference for both improving system performance and building an effective incentive mechanism for P2P file sharing systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4220-4241
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• 2017

For the downlink energy-harvesting small cell network, this paper proposes an interference management algorithm based on distributed coalitional game. The cooperative interference management problem of the energy-harvesting small cells is modeled as a coalitional game with transfer utility. Based on the energy harvesting strategy of the small cells, the time sharing mode of the small cells in the same coalition is determined, and an optimization model is constructed to maximize the total system rate of the energy-harvesting small cells. Using the distributed algorithm for coalition formation proposed in this paper, the stable coalition structure, optimal time sharing strategy and optimal power distribution are found to maximize the total utility of the small cell system. The performance of the proposed algorithm is discussed and analyzed finally, and it is proved that this algorithm can converge to a stable coalition structure with reasonable complexity. The simulations show that the total system rate of the proposed algorithm is superior to that of the non-cooperative algorithm in the case of dense deployment of small cells, and the proposed algorithm can converge quickly.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.247-258
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• 2015

The purpose of this study is to let the entire logistics system be managed in cyberspace by effectively sharing the logistics information between companies involved in the process, changing conventional commerce to electronic commerce. Most of the goods traded through electronic commerce are small goods involving small business transactions. This produces many problems in shipping and delivery and the leads an inefficient logistics system. Another problems is that there is no sharing of information that process the logistics flow and no systematic management of pick-up and delivery information. As a result, rise in logistics cost, longer delivery period and poor service quality are inevitable and these results are becoming an obstacle in the widespread usage of the electronic commerce. Companies that are part of logistics center can cooperate logistics business in Cyber space and share the entire logistics information through the cyber logistics center. This turns out in effective sharing of logistics information, and thus, allows efficient management of logistics, improves logistics service, and reduces logistics cost.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.821-827
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• 2009

Currently, with the development of web 2.0 knowledge sharing system became more and more important. In this paper, we proposed and implemented seminar assistant system using database system and knowledge sharing system on public seminar. We recorded speaker's voice and presentation files on our system and user can review past talks on our seminar review systems. Our database system is implemented using MS SQL, and Input/Output Completion Port(IOCP) socket model as our server side network module. Also we used presentation software using Direct Show with MFC and Windows Presentation Foundation(WPF). and our review system is based on WFP programmed with C# language.

• Journal of Information Technology Applications and Management
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• v.10 no.3
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• pp.1-22
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• 2003

P2P systems have been studied by many researchers in universities and commercial firms in recent years. In this study. we design and implement a system that makes UP for shortcomings of currently available P2P systems. Gnutella and Napster. The study also includes an efficiency analysis scheme conducted through a series of experimental data. The data sharing system of the study demonstrated duality of roles(client, service) of peers. But, their roles were separated from the existing client-server systems. Also, the study implements mechanism that shows the redundancy of data to communicate efficiently among peers for transferring data. The results of performance measure of the system shows that the amount of information shared by peers increases as the amount of peers increases but with no significant increase in response time. This constant response time is far more stable and faster than current file sharing systems. such as Gnutella and Napster. Business applications such as knowledge management, enterprise information portal management and transfer of data are done by use of supercomputers. They need to extend their systems to equip with more capacity and throughput as the number of clients increases. Moreover, they will face with more complicated problems if integration with new systems exists. If this JDSS is introduced to these business applications. it would easily augment scalability of the system with high performance at less expense.

• Journal of radiological science and technology
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• v.24 no.2
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• pp.71-75
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• 2001

As the adoption of PACS and hospital information system among university hospitals and hospital level institutions grows bigger, the need of sharing and transferring medical information among medical institutions is rising. For the medical information, which is saved in the hospital medical system, to be transferred within the same hospital, domestic, or foreign medical institutions, a standard protocol is necessary. But realistically, most of the domestic hospitals do not abide by H7L which is the HIS standard and so, information transferring is not possible as of present. As such, the purpose of this research is to implement the information between HIS and PACS to an international standard by constructing HL7 messages through HL7 Interface. which will eventually make possible information transferring between different hospitals. Our research team has developed a method which will make the PACS equip hospitals that do not follow HL7 standard which will make possible to transfer information between HIS and PACS through HL7 Message. By constructing message files, which follow the form of HL7 Message in the HL7 Interface, they can be transferred to PACS through the ftp protocol. The realization of the HIS/OCS Interface through HL7 enables data transferring between domestic and foreign medical institutions possible by implementing the international standard in the PACS and HIS data transferring process. The HL7 that our research team has developed made patient data transfer between medical institutions possible. The Interface is for a specific system model and in order for the data transfer between different systems to be realized, interfaces that are fit for each system must be needed. If the interface is improvised and implemented to each hospital's information system, the data sharing among medical institutions can be broadened.

• The Journal of Korean Association of Computer Education
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• v.16 no.1
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• pp.97-110
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• 2013

The purpose of this study is to analyze the needs of teachers as main users to make suggestions for active use of educational information sharing system. The study sets three research tasks about the problems of the current system, improvements, and desired content from the perspective of teachers. To collect specific opinions, we conducted an open questionnaire survey and made a qualitative analysis using the NVivo 10 program. The present system has such problems as functional issues, lack of data reliability, systemic problems for sharing and use. We suggest that in order to enhance Web site services, authoring tools for editing contents and new search engines with customized search function need to be provided. In addition, the open market service system has to be established, so that teachers can actively create, share, and distribute to meet the various needs of teachers. Finally, to promote free access to the system, copyright issues need to be resolved to prevent the potential digital piracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2073-2085
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• 2012

Recently, the International Telecommunication Union allocated the 470-862 MHz band to the digital broadcasting (DB) service. Moreover, the 790-862 MHz sub-band will be allocated to the next-generation mobile system, known as the International Mobile Telecommunication - Advanced (IMT-A), and to the DB on a co-primary basis in the year 2015. Currently, two candidate technologies are available to represent the IMT-A system; the Mobile WiMAX and Long Term Evolution - Advanced (LTE-A). One of the main criteria of the IMT-A candidate is to not cause additional interference to the primary service (i.e., DB). In this paper, we address the spectrum sharing issue between the IMT-A candidates and the DB service. More precisely, we investigate the interference effect between the DB service and the mobile network, which could be either LTE-A or WiMAX. Our study proposes a spectrum sharing model to take into account the impact of interference and evaluates the spectrum sharing requirements such as frequency separation and separation distance. This model considers three spectrum sharing scenarios: co-channel, zero guard band, and adjacent channel. A statistical analysis is performed, by considering the interferer spectrum emission mask and victim receiver blocking techniques. The interference-to-noise ratio is used as an essential spectrum sharing criterion between the systems. The model considers the random distribution of the users, antenna heights, and the bandwidth effect as well as the deployment environment in order to achieve spectrum sharing. The results show that LTE-A is preferable to WiMAX in terms of having less interference impact on DB; this can eventually allow the operation of both services without performance degradation and thus will lead to efficient utilization of the radio spectrum.

• Convergence Security Journal
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• v.16 no.4
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• pp.25-34
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• 2016

This paper shall suggest the improvement model for invigorating cyber threat information sharing from the national level, which includes, inter alia, a comprehensive solutions such as the legislation of a guideline for information sharing, the establishment of so-called National Center for Information Sharing, the construction and management of a integrated information system, the development of techniques for automatizing all the processes for gathering, analyzing and delivering cyber threat information, and the constitution of a private and public joint committee for sharing information, so much so that it intends to prevent cyber security threat to occur in advance or to refrain damage from being proliferated even after the occurrence of incidents.