• Journal of Astronomy and Space Sciences
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• v.23 no.4
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• pp.337-344
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• 2006

KVN simulation, which is focused on evaluating the impacts of KVN to geodetic VLBI network, was performed. The KVN is under construction with three radio telescopes VLBI system for radio astronomy and space geodesy. To distinguish the impacts of KVN on global and local scale networks, we designed two different sizes of VLBI networks, namely, KVN-Asia and KVN-Pacific. While the former consisted of Far East Asia region VLBI stations, the latter consisted of pacific region VLBT stations. The primary purpose of our simulation is quantitative evaluation of KVN impacts before and after the participation of KVN in the previous two virtual networks. We selected two different sets of parameters to be estimated in the simulation as indices of evaluating estimation precision: station coordinates and EOPs. The station coordinates are evaluating index for KVN-Asia and the EOPs are another evaluating index for KVN-Pacific. From the simulation results of comparisons between evaluating indexes, 50% and 20% of maximum improvements for KVN-Asia and KVN-Pacific were anticipated respectively. We expect that the space geodetic use of KVN will be focused on the several promising research fields which are proposed through the simulation results.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1316-1318
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• 2002

A methodology for reliability and economic analysis of wind embedded electric power system is presented in this paper. This is done by evaluating the reliability index, loss of load expectation (LOLE), for the power system with and without integration of wind system in the overall electric power system. Economic analysis of the wind energy embedded electric system is done in terms of conventional fuel saving assessment due to the use of wind power generation units.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.26-32
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• 2011

The object of this paper is to optimize the battery system for supplying stably power in separate house in which a PV-wind hybrid power generation system is applied. In a power system to be used in a stand alone, it is very important to build optimize the electrical storage system and to utilize it for supplying stably output voltage when there is a shortage of the power generation capacity or there is no sunshine, or when power is to be supplied with a load. This paper provides an optimized method to evaluate capacity of battery by analyzing advantages and disadvantages of the existing battery evaluating method being used in each company for supplying stably power in separate house utilizing the new renewable energy such as a light of the sun.

• Korean Management Science Review
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• v.9 no.1
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• pp.53-65
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• 1992

Decision Support System(DSS) is an advanced information system concept prevailing since 1980s. It supports managers' decision making activities by providing not only information but decision alternatives. It essentially consists of the components of database, modelbase and dialogue systems. With the development of its databases, POSCO needs a number of modelbases in establishing DSSs in various areas such as production planning and investment. This research particularly focuses on establishment of a mid-and long-range investment DSS and investigates the necessity and the problems of an investment DSS and the decision criteria for investment priority. We (1) propose a modelbase which uses the concepts of Analytic Hierarchy Process(AHP) and Zero-Base Budgeting(ZBB), along with an appropriate scoring method, database and dialogue system to support the investment manager in evaluating investment proposals ; (2) implement the system using relational database management system ; and (3) discuss the results of implementing the investment DSS.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.698-704
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• 2012

This paper proposes a new methodology for evaluating the probabilistic reliability based grid expansion planning of composite power system including the Wind Turbine Generators. The proposed model includes capacity limitations and uncertainties of the generators and transmission lines. It proposes to handle the uncertainties of system elements (generators, lines, transformers and wind resources of WTG, etc.) by a Composite power system Equivalent Load Duration Curve (CMELDC)-based model considering wind turbine generators (WTG). The model is derived from a nodal equivalent load duration curve based on an effective nodal load model including WTGs. Several scenarios are used to choose the optimal solution among various scenarios featuring new candidate lines. The characteristics and effectiveness of this simulation model are illustrated by case study using Jeju power system in South Korea.

• IE interfaces
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• v.18 no.1
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• pp.44-51
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• 2005

The rapid expansion of the Internet-related technology has changed the current commercial transaction process. In the physical commercial transaction, most deals are accomplished through the negotiation process except a fixed price system. Thus, the negotiation is essential to conclude the business transactions. Especially, under the e-commerce environment, an automated negotiation system is necessary to respond quickly and flexibly to the diverse environmental changes and also to perform negotiations consistently and effectively. To this end, we develop an automated negotiation system using multi-agent technology. This new system includes such functions as creating negotiation proposals automatically, evaluating the counterpart’ proposals, and preparing counter offers.

• IE interfaces
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• v.5 no.2
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• pp.53-74
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• 1992

In order to design an FMS(Flexible Manufacturing System), an effective design tool is necessary for selecting and anlayzing the complex interacting factors of a manufacturing system. Considering most of the previous researches have been focused on evaluating the designed FMS, development of an integrated FMS designing system is needed for performing the design task such as machine selection and layout determination as well as the evaluation task of the designed FMS. In this paper, we developed a prototype of such a system called the intelligent FMS designer based on the techniques of Expert System and Simulation. By using this designing system, possible design alternatives can be analyzed and appropriate manufacturing capacity can be estimated at the designing stage. Various operating characteristics of the designed FMS can be also predicted before it is implemented. Eventually a suitable design alternative can be provided with cost details within relatively short time period. To demonstrate the performance and effectiveness of the designer, a simple example is tested. The results show a great potential for automating design processes of an FMS.

• Coupled systems mechanics
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• v.2 no.4
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• pp.303-327
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• 2013

The coupled free vibration of flexible structures and on-board liquid in zero gravity space was analyzed, considering the spacecraft main body as a rigid mass, the flexible appendages as two elastic beams, and the on-board liquid as a "spring-mass" system. Using the Lagrangians of a rigid mass (spacecraft main body), "spring-mass" (liquid), and two beams (flexible appendages), as well as assuming symmetric motion of the system, we obtained the frequency equations of the coupled system by applying Rayleigh-Ritz method. Solving these frequency equations, which are governed by three system parameters, as an eigenvalue problem, we obtained the coupled natural frequencies and vibration modes. We define the parameter for evaluating the magnitudes of coupled motions of the added mass (liquid) and beam (appendages). It was found that when varying one system parameter, the frequency curves veer, vibration modes exchange, and the significant coupling occurs not in the region closest to the two frequency curves but in the two regions separate from that region.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.215-221
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• 2014

The Fingerprint recognition system is a system which identify the user's identify by verifying user's fingerprint and prepared data. The performance of fingerprint recognition system is dependent on 'fingerprint recognition time' and 'fingerprint recognition accuracy' and so on. In this paper, we developed a evaluation model about efficiency based on ISO quality evaluation standard for evaluating of quality level of fingerprint recognition system. We expect to contribute to construct and use of evaluation criteria based on quality evaluation standard by this study.

• Journal of information and communication convergence engineering
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• v.16 no.1
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• pp.31-37
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• 2018

In this work, we propose an analytic framework for evaluating the quality of service and dimensioning the link capacity in the gateway router of a smart farm with a greenhouse eco-management system. Specifically, we focus on the gateway router of an IoT network that provides an access service for smart farms. We design the link capacity of a gateway router that is used for the remote management of the greenhouse eco-management system to accommodate both time-critical and delay-tolerant traffic in a greenhouse LAN. For this purpose, we first investigate the ecosystem for smart farm, and we define the specification and requirements of the greenhouse eco-management system. Second, we propose a system model for the link capacity of a gateway that is required to guarantee the delay performance of time-critical applications in the greenhouse LAN. Finally, the validity of the proposed system is demonstrated through a series of numerical experiments.