• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.70.1-70
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• 2002

In the fuzzy applications and theories, it is very important to consider how to design the optimal fuzzy model from short training data, in order to construct the reasonable fuzzy model for identifying the practical process. There are several concerns to be confirmed for efficient fuzzy model design. One of concern is the optimization problem of the fuzzy model. In various applications, the genetic algorithm is widely applied to obtain optimal fuzzy model and other cases that adopt evolutionary mechanism of the nature. If we use natural selection and multiplication operation of the genetic algorithm, early convergence to local minimum can be occurred. In other word, we can find only optimum...

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.37.2-37.2
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• 2010

The IMS (Infrared or Intermediate-wide, Medium-deep Survey) program for the search of z~7 quasars has been running since last year. In order to discover enough number of quasars at z~7, a strategy sufficing both survey area (~150 square deg.) and image depth (23 AB mag in J filter), together with using existing multi-wavelength data is chosen. We have been carrying imaging observations with the UKIRT 4m telescope, now covering ~50 square deg. (including UKIDSS survey area) of J-band data. We then used selection in color-color space to choose high-z quasar candidates having the rest-frame Ly-alpha break, and to exclude contamination from stars and galaxies at low-z. We show quasar candidates of redshift z~7 and z~6, out of 25 square deg. data analyzed, and note implications and future plans.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4293-4304
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• 2014

In order to ensure the wireless connectivity and seamless service to mobile users, the next generation network system will be an integration of multiple wireless access networks. In a heterogeneous wireless access system, bandwidth allocation becomes crucial for load balancing to avoid network congestion and improve system utilization efficiency. In this article, we propose a new dynamic bandwidth allocation scheme for hierarchical wireless network systems. First, we derive a multi-objective decision criterion for each access point. Second, a bargaining strategy selection algorithm is developed for the dynamic bandwidth re-allocation. Based on the intervenient Stackelberg game model, the proposed scheme effectively formulates the competitive interaction situation between several access points. The system performance of proposed scheme is evaluated by using extensive simulations. With a simulation study, it is confirmed that the proposed scheme can achieve better performance than other existing schemes under widely diverse network environments.

• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.113-116
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• 2003

In the recent environment of globalization where fierce competitions exist between manufacturers, SRM(Supplier Relationship Management) plays important role in the strategies of companies, and managements of companies try their best efforts in establishing the strategy to accomplish the innovative relationship between supply chain channels. The structure of the partnerships we develop with not only customers but also suppliers will in many cases determine the degree of success of the relationship. A successful partnership provides an opportunity for shared risk while maximizing the opportunity for mutual success whether it's with supplier. To follow this paper show how SLV(Supplier Lifetime Value) can be used to structure the supplier in automotive part manufacturer, This method of selection is described, and a detailed example of how SLY can be used and allocation of order quantity for the selected suppliers also are provided.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.232-237
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• 2008

Several research institutes including KISTEC and KRRI etc., recently, have studied maintenance activities and performance, in order to determine proper maintenance level and maintenance cost of rail tracks. But it may extremely difficult to make a decision in maintenance matters of concrete track and ballast containing other sub-components. For these reasons, this study investigate variables related to current maintenance, essential maintenance, and preventive maintenance. It is intended to suggest estimation method of proper maintenance cost maximizing rail track performance. It is stated that proposed approach may be very useful to make a decision of proper maintenance level. Typical section of rail track is applied for calculation of life cycle cost according to each maintenance strategy. A proper profile for maintenance is determined minimum life cycle

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.97-100
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• 2000

In previous research of social dilemma, there is no extended game that the players can select one game out of some social dilemma games. We propose this kind of game as ＂Distributed Social Dilemma＂ In this game, each player tries to acquire the adaptive strategy throughout local interactions. We make use of GA as evolutionary operations. In this paper, our purpose is to examine how the game selection of players influences the evolution of cooperation in distributed social dilemma. In order to examine, we formulate distributed social dilemma by Game Theory and use agent-based simulation that each agent is regard as player

• Journal of Power Electronics
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• v.19 no.6
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• pp.1403-1412
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• 2019

A coupled inductor-dual boost-inverter (CIDBI) with a differential structure has been presented for application to a micro-inverter photovoltaic module system due to its turn ratio of a high-voltage level. However, it is difficult to design a CIDBI converter with a conventional PI regulator to be stable and achieve good dynamic performance, given the fact that it is a high order system. In view of this situation, a sliding mode control (SMC) strategy is introduced in this paper, and two different sliding mode controllers (SMCs) are proposed and adopted in the left and right side of two Boost sub-circuits to implement the corresponding regulation of the voltage and current. The schemes of the SMCs have been elaborated in this paper including the establishment of a system variable structure model, selection of the sliding surface, determination of the control law, and presentation of the reaching conditions and sliding domain. Finally, the mathematic analysis and the proposed SMC are verified by experimental results.

• Journal of The Korean Astronomical Society
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• v.46 no.3
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• pp.103-123
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• 2013

Star clusters are superb astrophysical laboratories containing cospatial and coeval samples of stars with similar chemical composition. We initiate the Sejong Open cluster Survey (SOS) - a project dedicated to providing homogeneous photometry of a large number of open clusters in the SAAO Johnson-Cousins' UBV I system. To achieve our main goal, we pay much attention to the observation of standard stars in order to reproduce the SAAO standard system. Many of our targets are relatively small sparse clusters that escaped previous observations. As clusters are considered building blocks of the Galactic disk, their physical properties such as the initial mass function, the pattern of mass segregation, etc. give valuable information on the formation and evolution of the Galactic disk. The spatial distribution of young open clusters will be used to revise the local spiral arm structure of the Galaxy. In addition, the homogeneous data can also be used to test stellar evolutionary theory, especially concerning rare massive stars. In this paper we present the target selection criteria, the observational strategy for accurate photometry, and the adopted calibrations for data analysis such as color-color relations, zero-age main sequence relations, Sp - MV relations, Sp - $T_{eff}$ relations, Sp - color relations, and $T_{eff}$ - BC relations. Finally we provide some data analysis such as the determination of the reddening law, the membership selection criteria, and distance determination.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.6
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• pp.967-978
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• 2016

This study examines consumers' multi-channel choices in the search phase and purchasing phase stage according to price sensitivity and product characteristics in order to propose a multichannel strategy. For the research, one-way ANOVA, t-test, clustering analysis, and crosstabs are used for the descriptive analysis of 317 surveys on men and women conducted in 2014. The findings are as follows. First, consumers that both experience goods and search goods rely on surrounding advice as well as a search channel regardless of price sensitivity. Second, channel selection differs by price sensitivity when it comes to purchasing phase. Consumers with high price sensitivity tend to purchase from online channels; however, consumers with low price sensitivity tend to purchase from off line channels in cases of search goods. Meanwhile, cases of experience goods have no meaningful result. Third, consumers are divided into 3 groups by the tendency of channel selection. In case of experience goods, search channel choice is aligned with purchasing channel; however, search channel choice is not aligned with purchasing channel in search goods. This study provides clear information on fashion consumers' behavior on multi-channel choices compared to ones for search goods consumers on strategic strategies for fashion companies.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.174-186
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• 2011

This research addresses global status of Korean media firms and their future directions. Mapping of major international media firms all over the world is used in order to explain global status fully. In the four categories that classified media firms using Forbes Global 2000 mapping, all Korean media firms are included in the fourth group, which is the weakest in terms of global competitiveness. Therefore, it is essential to trace appropriate global strategy from the media industry value chain that has competence. This paper finds out that Korea has advantage in the contents, terminal, and next generation networks. That means alliance strategies of contents-terminal-next generation network have advantage to evolve into global media firms. Moreover, Korean media companies should adopt selection and concentration strategy in terms of geographical expansion. As Korea's broadcasting and game contents are already popular in Asian and Latin American regions, they would better to enter the emerging markets. In so doing, terrestrial broadcasters and game service providers should lead the way.