• Journal of IKEEE
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• v.22 no.2
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• pp.402-407
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• 2018

Link selection strategy has been an important technical issues of relay network. In this paper, we introduce a link selection scheme in the bidirectional, buffer-aided relay network. Three kinds of information such as the states of the queue at the relay buffer, the qualities of the links, and the states of the queues at the user buffer are considered. Throughput and delay performance is evaluated under three cases with different available information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.653-656
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• 2007

1998년 European Commission에서 권고한 이래 LRIC 모형은 미국 및 유럽 각국의 규제기관 (National Regulatory Authorities ; NRA)에서 상호접속규제를 시행하는데 사용되는 주요 수단이다. 2004년 영국의 이동전화 착신서비스에 대한 보고서에서 영국의 Ofcom은 LRIC를 2G방식의 이동전화 착신서비스 제공에 따른 원가산정 방법으로 채택하고 있다. 그러나 기존 2G 사업자들이 3G시장에 참여함에 따라 2G 음성통화가 3G로의 전이가능성이 제기되어 3G 서비스제공에 따른 2G 접속료 시장의 충격을 완화하고자 LRIC모형에 3G서비스를 추가하게 되었다. 이동망 원가모형의 기본 구조는 크게 다음과 같은 4개의 모듈로 구성되는데, 이중에서 사업 자간 문제제기가 많고 이견이 많았던 Network모듈과 이동망 모형의 선행모듈인 Input 모듈에서 제기된 이슈사향을 살펴보고, 국내 이동망 LRIC 모듈 개발시의 시사점을 도출하고자 한다.

• Journal of Navigation and Port Research
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• v.34 no.2
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• pp.91-95
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• 2010

Recently IMO and IALA have developed the strategy of e-Navigation and the concepts of VTM to enhance the safety, efficiency and security of vessel traffic and protection of the marine environment. And current technical and functional trends require vessel traffic management systems to be improved so as to control vessel traffic not only in waters of harbour area, but also within EEZ waters. Under the consideration of these circumstances, a three-layered vessel traffic management system was proposed in this paper. The proposed system consists of three sub-systems, called Local VTS, Regional VTS and National VTS, and those sub-systems are designed respectively to be suitable for managing vessel traffic within their own jurisdiction waters.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.367-381
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• 2005

On the situation cooperating with business partners on the supply chain, systematic decision making process is a critical issue for them. The two major issues of purchasing strategy such as selecting vendors and managing them are important part of their overall business activities. This study mainly focus on the former issue of the vendor selection. Through the empirical study, analytical hierarchy process (AHP) method was applied to select vendors among supplier vendors based on four selection criteria such as the level of quality, product on management ability, delivery, and price. The results of study showed the main criteria of vender selection was the ability of quality management. The vender selected based on AHP and the current selection method was different, but implicitly projected the dilemma situation between quality and price which occurs in decision making process of real life.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.1 s.109
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• pp.61-66
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• 2005

The grade change operations In paper mills exhibit inherent nonlinear dynamic characteristics. For this reason, the conventional model predictive control techniques based on linear process models are not adequate for the grade change operations. In this paper, a bilinear model for the nonlinear grade change processes was presented first and optimal input variables were calculated by using one-step-ahead predictive control method. Numerical simulations showed that the control performance lied within acceptable range and that the bilinear model predictive control scheme was highly promising control strategy for the grade change operations.

• Journal of Information Technology Applications and Management
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• v.20 no.4
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• pp.111-125
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• 2013

This study investigates how enjoyment (or playfulness) affects user acceptance of hedonic-oriented (or pleasure) information technology based on the technology acceptance model (TAM). A research model was made to examine the effect of enjoyment on the user acceptance of hedonic information technology. 186 responses were collected from university students who had experiences on Daum's Digital View which is a well-known example of digital signage technology. The result of the statistical analysis reveals that enjoyment also had a strong effect on the acceptance of hedonic information technology, in addition to perceived usefulness and perceived ease of use. However, perceived usefulness is reported to most strongly influence the adoption of Digital View. The effect of enjoyment on intention to use was also significant, but enjoyment shows a much low degree of influence than perceived usefulness on intention to use.

• Journal of Power Electronics
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• v.2 no.1
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• pp.67-75
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• 2002

This paper presents the control algorithm for maximum efficiency drives of an induction motor system with the high dynamic performance. This system uses a simple model of the induction motor that includes equations of the iron losses. The model, which only requires the parameters of the induction motor, is referred to a field-oriented frame. The minimum point of the input power can be obtained at the steady state condition. The proposed optimal efficiency control algorithm calculates the reference torque and flux currents for the vector control of the induction motors. A 32 bit floating point TMS320C32 DSP chip implements the drive system with the efficiency optimization controller. The results show the effectiveness of the control strategy Proposed for the induction motor drive.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.4
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• pp.78-84
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• 2007

After 6 Sigma administration is introduced in domestic in 1997, many corporations are utilizing by survival strategy and method of administration reform. This is applied in all field that this led to R&D from service industry by the next. Success factors by each field was studied and announced applying in various types of business. The Korail and Korea Post, the Ministry of Environment and various public corporation and governmen and municipal office are introduce and utilizing 6 Sigma administration by innovation method present. But, research about success factor that special quality of public sector is considered up to now was almost no. This treatise analyzed 6 Sigma' success factors and effect relation to public corporation.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.142-145
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• 2002

This paper presents the electromagnetic field water treater system with the high performance for a good quality of water. The electromagnetic field water treater consists of a solion, a solion body. and a high voltage converter. The high voltage converter is controlled by PWM current controller. The high voltage converter of 13W is designed for an isolation operation ramp. an isolation current detector, and an over current protector. Using the high voltage PWM converter, the system with the proposed electromagnetic field water treater can be controlled easily. Simulation and experimental results show the effectiveness of the system strategy proposed for the scale rejection.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.62.3-62.3
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• 2019

After first identification of electromagnetic counterpart of gravitational wave source (GW170817), era of multi-messenger astronomy has begun. For specifying coordinate, magnitude, and host galaxy information, optical follow-up observation of GW source becomes important. With following engineering run and O3 run of LIGO and VIRGO starting in March 2019, we present searching strategy for optical counterpart of GW source using KMTNet. 24 hours monitoring system and large field of view (4 square-degree) of KMTNet are advantage to discover a transient like GW event. By performing tiling observation of high probability area in GW localization map, we expect to observe early light-curve of GW optical counterpart. After identification, follow-up observation with various KMTNet bands and other telescopes like Gemini and UKIRT will also be performed. We will study collision mechanism, progenitor, and characteristics of host galaxy using observation data of GW source.