• 기술혁신학회지
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• 제1권1호
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• pp.117-124
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• 1998

Corporations are pursuing maximum returns from their R&D investment. They are also interested in sound measures to quantify returns. In fact, they use various measures and criteria for measuring returns from the R&D investment. But the fundamental problem is that there is no generic and widely acceptable measures and criteria. To make things more complicated, measures are very powerful and influential to the people in the corporations. Herbert Simon already indicated that people do many things but people usually do their best for the only tasks which are measured. Many researchers, like Chester(1995), are interested in R&D productivity measures and risks because what the company measures really influence R&D people and output. This article present design concepts of the R&D project selection and evaluation system in POSCO(Pohang Iron & Steel Company). This is an output extract from the 6-month joint activities with POSRI(POSCO Research Institute) researchers and POSCO R&D personnel. Process changes, new organizations and new selection and evaluation criteria are developed to improve R&D performance and to enhance technology management of the POSCO. This article covers new selection and evaluation criteria only. We would like to share our experience about how we redesign the selection and evaluation of R&D projects. We also bring insights how we seamlessly integrate 4 different project selection and evaluation steps as a whole. We hope that this case will give you a clue to improve your R&D management.

• 산업경영시스템학회지
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• 제32권3호
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• pp.142-158
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• 2009

The supplier selection problem is perhaps the most important component of the purchasing function. Some of the common and influential criteria in the selection of a supplier include quality, price, delivery, and service. These evaluation criteria often conflict, however, and it is frequently impossible to find a supplier that excels in all areas. In addition, some of the criteria are quantitative and some are qualitative. Thus, a methodology is needed that can capture both subjective and objective evaluation measures. The Analytic Hierarchy Process(AHP) is a decision-making method for ranking alternative courses of action when multiple criteria must be considered. This paper proposes the AHP-based approach which can structure the supplier selection process and the achievements-based procedure which can allocate order quantities for the selected suppliers In automotive part manufacturers. Also, through the practical case of 'D' automotive part manufacturing company, we shows that the proposed AHP based supplier selection approach and the achievements-based allocation procedure of order quantity can be successfully applied for supplier selection and order quantity allocation problems.

• Journal of Communications and Networks
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• 제10권2호
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• pp.175-185
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• 2008

In this paper, we investigate the effect of cooperative and selection relaying schemes on multiuser diversity in downlink cellular systems with fixed relay stations (RSs). Each mobile station (MS) is either directly connected to a base station (BS) and/or connected to a relay station. We first derive closed-form solutions or upper-bound of the ergodic and outage capacities of four different downlink data relaying schemes: A direct scheme, a relay scheme, a selection scheme, and a cooperative scheme. The selection scheme selects the best access link between the BS and an MS. For all schemes, the capacity of the BS-RS link is assumed to be always larger than that of RS-MS link. Half-duplex channel use and repetition based relaying schemes are assumed for relaying operations. We also analyze the system capacity in a multiuser diversity environment in which a maximum signal-to-noise ratio (SNR) scheduler is used at a base station. The result shows that the selection scheme outperforms the other three schemes in terms of link ergodic capacity, link outage capacity, and system ergodic capacity. Furthermore, our results show that cooperative and selection diversity techniques limit the performance gain that could have been achieved by the multiuser diversity technique.

• 한국병원경영학회지
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• 제12권4호
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• pp.1-21
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• 2007

The relaxation of the regulation in selection of medical institution allows patients to use their own judgement in choosing proper institution for their diseases. Since the change of the regulation, there should have been many changes in medical institution selection behavior. The analysis of the change in disease specific selection pattern is critical because there be an optimal selection criteria that ensure the efficient and effective utilization of medical resources. This study analysis the institution selection factors by comparing the choice among the cases of acute diseases, the cases of chronic diseases, inpatient services, outpatient services, and emergency medical service. The comparisons performed in terms of size, class and other characteristics of medical institutions. For the study the nationally surveyed database was used and the data were analyzed using logistic regression procedure. The results indicates that the primary care facilities were not properly utilized. This study speculates that the reason for the undesirable pattern of utilization is that the roles of primary care facilities in the healthcare delivery system was not clearly defined. Based on the results, the medical policy implications are discussed.

• 한국인터넷방송통신학회논문지
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• 제16권3호
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• pp.65-71
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• 2016

무선 페이딩 채널에서 시스템의 성능 저하를 효과적으로 개선하기 위하여 협동 릴레이 시스템에 관한 연구가 활발히 진행되고 있다. 그동안의 연구는 고정된 릴레이를 가정하였는데, 최근에는 실제 이동통신 환경을 고려하여 공간적으로 랜덤하게 분포된 릴레이를 갖는 협동 릴레이 시스템의 연구가 시작되고 있다. 특히 통신 자원의 효율이 높은 추가 기회전송 협동 릴레이 시스템에서는 릴레이를 선택하는 방법에 따라서 시스템의 성능이 변화하는데, 이에 대한 비교 연구는 발표되지 않았다. 따라서 본 논문에서는 최대 SNR 선택법과 최대-최소 SNR 선택법을 대상으로 최대비 결합을 사용한 추가 기회전송 협동 릴레이 시스템의 성능을 유도하였고, 송신전력이 소스와 릴레이로 배분되었을 때의 오수신율을 비교하였다. 본 논문의 해석적 결과는 이동통신 시스템에 기회전송 증가 릴레이 시스템을 도입하였을 경우 릴레이를 선택하고 송신 전력을 배분하는데 이론적 근거로 활용할 수 있을 것으로 생각된다.

• 정보처리학회논문지D
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• 제12D권3호
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• pp.471-480
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• 2005

웹 기반의 원격 교육에서 평가를 위해 출제되는 문제들은 주로 고정 출제나 무작위 출제 방식 또는 난이도에 따른 자동 출제 방식을 이용하고 있다. 이중에서 난이도에 따른 자동 출제 방식은 해당 문제의 초기 난이도 부여에 대한 객관성과 주어진 난이도를 이용한 보다 효율적인 문제의 출제 그리고 출제된 문제들에 대한 학습자들의 평가 결과로서 해당 문제들의 난이도를 재조정하는 것이 문제의 핵심이라 할 수 있다. 본 논문에서는 웹 기반의 학습 시스템에서 평가를 위한 자동 출제 방식을 이용함에 있어서 첫째, 난이도뿐만 아니라 학습 범위를 함께 고려한 새로운 난이도별-영역별 문제 출제 알고리즘을 제시하고 둘째, 평가 결과를 바탕으로 해당 문제들의 난이도를 다시 조정하는데 있어서는 학습자들의 학습 능력을 고려한 새로운 난이도 재조정 알고리즘을 제시한다. 제시된 알고리즘을 구축된 웹기반 학습 시스템에서 기존 알고리즘과 비교 분석해 본 결과 보다 효율적임을 확인할 수 있었다.

• 한국통신학회논문지
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• 제40권3호
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• pp.459-468
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• 2015

본 논문에서는 하나의 AP가 다수의 사용자를 지원하는 상향링크 다중사용자 하이브리드 빔포밍 시스템을 고려한다. 상향링크 다중사용자 하이브리드 빔포밍 시스템의 성능은 채널에 아날로그 빔이 결합된 형태의 유효 채널에 의해서 결정된다. 따라서 시스템의 성능을 최대화하기 위해서는 채널의 정보를 획득하고 획득된 채널 정보를 이용해서 아날로그 빔을 적절히 선택해야 한다. 본 논문에서는 상향링크 다중사용자 하이브리드 빔포밍 시스템에 적합한 채널 추정 방법과 저복잡도 아날로그 빔 선택 알고리즘을 제안한다. 또한 수학적으로 계산 복잡도 분석을 통해서 제안하는 저복잡도 아날로그 빔 선택 알고리즘이 최적의 아날로그 빔 선택 알고리즘에 비해서 복잡도가 훨씬 작은 것을 보여준다. 모의 실험 결과를 통하여 동일한 조건 하에서 제안된 저복잡도 아날로그 빔 선택 알고리즘이 최적의 아날로그 빔 선택 알고리즘에 비해 줄어든 계산 복잡도에 비하여 성능 면에서 열화가 거의 없는 것을 확인한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.632-635
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• 2002

There are more than five dozen different RP(rapid prototyping) systems in the world and they are fairly expensive. All those systems have different capabilities and requirements in that each of them gives different tolerance, application field and part strength, etc. This situation may cause a problem of selecting an appropriate RP system. This paper presents an expert system, utilizing an algorithm that is composed up of rules to derive recommendations and answers to queries of the RP users. The expert system incorporates RP machines commercially available and adopts multi-selection criteria, namely, machine price, accuracy, build size, adopted process, etc. In the expert system, forward reasoning method is adopted and external spreadsheet for sub-data of the RP systems is used. The rules and knowledge are obtained from interviews and discussions with RP vendors and users, appropriate research publications and other reference materials.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.19-20
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• 2006

In this paper, to reduce uplink feedback information for the beam weight and simultaneously maintaining the performance, we propose a MIMO-OFDM (Multi Input Multi Output-Orthogonal Frequency Division Multiplexing) system based on beamforming with antenna selection. In the proposed system, to perform the beamforming with more useful transmit antennas, the optimal combination of transmit antennas with maximum MRT (Maximum Ratio Transmission) beamforming gain is selected. Simulation results reveal that the proposed MIMO-OFDM system adopting the beamforming with antenna selection can reduce the feedback information for the beam weights as compared to the system using all the transmit antennas without serious degradation of system performance.

• 한국컴퓨터정보학회논문지
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• 제21권1호
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• pp.9-16
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• 2016

In this paper, we present a performance evaluation agent based on fuzzy cluster analysis and validity measures. The proposed agent is consists of three modules, fuzzy cluster analyzer, performance evaluation measures, and feature ranking algorithm for feature selection step in CAD system. Feature selection is an important step commonly used to create more accurate system to help human experts. Through this agent, we get the feature ranking on the dataset of mass and calcification lesions extracted from the public real world mammogram database DDSM. Also we design a CAD system incorporating the agent and apply five different feature combinations to the system. Experimental results proposed approach has higher classification accuracy and shows the feasibility as a diagnosis supporting tool.