• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.75-80
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• 2008

Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. We have advanced the framework of the multiple time scale congestion control and showed its effectiveness at enhancing performance for the rate-based feedback control. Our contribution is threefold. First, we define a modular extension of the TCP-a function called with a simple interface-that applies to various flavours of the TCP-e.g., Tahoe, Reno, Vegas and show that it significantly improves performance. Second, we show that a multiple time scale TCP endows the underlying feedback control with proactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of the three traffic control dimensions-tracking ability, connection duration, and fairness-on performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.20
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• pp.123-138
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• 1989

The primary objective of the agency research in the game theory lives in the maintenance of Pareto is optimal condition for the optimal incentive contract. The basic concepts which are related to this objective are reviewed in connection with the general assumptions to model it, the moral hazard and adverse selection which arised from the information asymmetry, and finally the problem of risk distribution. The demand for auditing and the role of auditor have been addressed by ASOBAC. Issues which an auditor is explicitly introduced in a principal-agent framework have been addressed in this paper. These issues must be confronted to appropriately with the auditor, and to achieve an adequate understanding of optimal confronting arrangement with the auditor. The first step in introducing an auditor into this analysis is to examine the game-theoretic foundation of such a expended agency model. The Mathematical program formulated may not yield solution that are resonable. This arises because the program may call for the auditor and manager to play dominated Nash equilibra in some subgame. The nontrivial natures of the subgame implies that randomized strategies by the auditor and manager nay be of crucial importance. The possibilities for overcoming the randomized strategy problem were suggested; change the rule of the game and or impose covexity condition. The former seems unjustifiable in on auditing context, and the latter promising but difficult to achieve. The discussion ended with an extension of the revelation principle to the owner manager-auditor game, assuming strategies. An examination of the restriction and improvement direction of the basic concept of agency theory was addressed in the later part of this paper. Many important aspects of auditor incentives are inherently multiple-agent, multiple-period, multiple-objectine, phenomena and require further analyses and researches.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.6
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• pp.36-45
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• 1998

This paper discusses multiple access control aspects for a wireless extension of high-speed asynchronous transfer mode(ATM) networks. One challenging requirement is that mobile systems convey of diverse types of information including voice, computer data, facsimile, and video data that have different quality of service constraints. Basically, a centralized control scheme for a coordinated multiple access is required in order to efficiently accommodate multimedia traffic on wireless links. The proposed scheme dynamically scheduling the mobile terminal, which has data to transfer according to the service, types at base station. In this scheme, the scheduling algorithm is performed on the basis of traffic descriptors and QoS parameters, which required in the connection set up phase. As a consequence, the transmission scheduling is very flexible and can account for the different traffic rate and delay constraints that emerge from voice and data integration. The simulation result shows that the proposed scheme has better performance over other scheduling algorithms.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.229-239
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• 2011

This study aims to suggest profitability models of local cultural festival to be a focal point of local culture to overcome the abuses as an annual event led by the local government agencies have been in force in every local areas currently, to elicit the local residents' voluntary participation and to engage the outside tourists in connection of a more effective promotion and marketing. The festival is attractive to people with that provoke mirth and inspire curiosity, but the festival is not a one-time event ongoing maintenance enlarge: It is absolutely necessary in order to effort to reach at consumer-oriented quality of service. Also this research intends to present a activation scheme by developing profitability models to make profits while holding a number of risks taking into account the characteristics of the local festival service carried out. To this end, based on established research, leading indicator and expert opinion were analyzed through multiple regression analysis.

• Korean Journal of Human Ecology
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• v.15 no.3
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• pp.457-467
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• 2006

The following research compares two mostly-used apparel systems that are used in colleges of Korea, Gerber and PAD, by analyzing advantages and disadvantages of their Dart, Tuck and Pleats-related functions in pattern construction process. The results are the following: First, regarding transformation methods, Gerber system was able to use pivot method, while PAD system was able to use both pivot and slash method. As for movement, distribution, synthesis, folding, producing additional Dart function, the PAD system was not able to synthesize more than two Darts, and only showed differences for other functions. On the other hand, the diamond-shape Dart and diagonal Dart can be produced only in PAD system, while none of curvy shaped Dart can be produced in both systems. Second, as for pattern outer line connection capability, which is a Dart automatic transformation function, both systems showed unnatural shapes and need for correction. Third, when constructing according to the type of Tuck, we could distribute multiple Darts at a time with PAD system, while with Gerber system, distribution into multiple Darts at a time was impossible at all. Fourth, when constructing according to the contour of Pleats, Gerber system made it possible to make construction of multiple lines and box/inverted Pleats with just one order, but PAD system required repetitive tasks, which remains room for enhancement in regard to such inefficiency.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.253-261
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• 2006

In spite of the popularity of P2P technology, a multimedia streaming using the P2P technology has been neglected. The reason for this is that the P2P multimedia streaming has suffered from several inherent problems especially poor bandwidth and unreliable connection among peers. We suggest a Multi-Peer Binding Protocol (MPBP) in this paper that provides a virtual single channel composed of multiple connections to several peers to ease these problems. The protocol enables applications to download data from multiple peers simultaneously, so they can achieve throughput improvement and reliable streaming. For this, the MPBP splits media files into small chunks and provides a mechanism for identifying and transmitting each chunk. Implemented MPBP engine focuses on handling an abrupt disconnection from data sending peers and the evaluation result shows the MPBP is able to handle it gracefully. The MPBP is also desisted to support various media types. To verify this, video and audio applications are implemented using the MPBP engine in this paper.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.39-46
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• 2012

We can adapt telemedicine systems in advancement of information technology capabilities and increase of network bandwidth. The telemedicine service can be applied to a public health center, a school, a prison and islands in lacks of medical equipments and medical staffs. The telemedicine services which can be provided high quality medical services. We designed the multiple control server system consisting 3 sub-function, patients and doctors name list, network types, connection states and computer equipments. The telemedicine link configuration was decided as 'Flowing', or 'By-passing' in accordance the network type and bandwidth of patient systems or doctor systems. The multiple control server system was performed the best communication configuration over heterogeneous networks. This system was achieved high quality telemedicine services through dynamic wired and wireless networks at any time. This study represented a hybrid multimedia telemedicine system over heterogeneous networks. We expected that the designed system could provide not only the high quality services, tele-diagnosis and tele-consultation, but also the effective emergency telemedicine services to multi-patients in the heterogeneous network environments.

• Journal of Korea Technology Innovation Society
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• v.20 no.4
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• pp.858-887
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• 2017

This study deals with the cases of policy changes of the research council system which exists since 1999 as a policy tool to achieve the goals for autonomy and independence of Government-funded Research Institutes (GRIs) in the field of science and technology and their cooperation and organic connection. The purpose of the study was to analyze through which process policies about the research council system have changed and whether they resulted in the successful achievements of the aimed policy goals, and to contribute to the effective policy implementation in the future. The Research Council System of Science and Technology has been undergoing a change for four government replacements (from Kim Dae-jung's Government to Park Geun-hye's Government). In this study, the major policy making factors and the policy change process of each government case are analyzed in comparison using Kingdon's multiple streams framework, as a result, their policy change type by the Hogwood and Peters's theory and the achievement of their policy goals of autonomy and responsibility were examined.

• Progress in Superconductivity and Cryogenics
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• v.9 no.3
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• pp.37-40
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• 2007

Large critical current is one of the prerequisites for the design of superconducting electrical equipments with large power capacity. To enlarge the critical current. multiple parallel connection is inevitable. In multiple parallel superconducting coils. the difference in normal resistance of each shunt leads to unequal current distribution. which may yield burnout. Therefore. uniform current distribution is required for a stable operation of multiple parallel superconducting coils. In this paper, Rogowski coils were fabricated to measure each shunt current of a 4-parallel superconducting coil. Four Rogowski coils were installed at the copper bars, which are used as current leads in superconducting coils. As a result, linearity of the Rogowski coils was ascertained and coefficients of each coil, the ratio of voltage and current, were derived. The coefficients were compared with theoretically calculated values. Based on the coefficients, each shunt current was calculated in a 4-parallel superconducting coil, where uniform current. distribution was confirmed. This paper verified the feasibility of the fabricated Rogowski coils as well as operational stability of the 4-parallel superconducting coil in 77K.

• Journal of Digital Convergence
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• v.4 no.1
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• pp.31-41
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• 2006

This article introduces developing trends of an 'Ubiquitous Interface' as an access method for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. 'Ubiquitous Interface' is a relatively wide sense meaning not only physical interface of specified device or between processors, but anything method for access USN. These 'Ubiquitous Interface' able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Recently, strongly recommended current technologies are RFID, NFC, Multi-mode mobile terminal, UMA mobile terminal and Wearable computer as a future ubiquitous interface. These technologies are have to have flexibility and multiple physical communication channels for seamless service hand over and serve easy connection at huge USN to user. Also, they have to must have flexible software structure. Finally, through the 'Ubiquitous Interface', we will be experience of seamless communication and realize a real liberty of communication.