• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제11B권4호
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• pp.164-168
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• 2001

In this paper voltage source FEA for hysteresis motor considering magnetic hysteresis characteristics is presented. The Preisach model is used as a hysteresis model. System matrix whose unknown variables are vector potentials and currents is formulated for voltage source. The stiffness matrix is maintained constant by using M-iteration method. Therefore the calculation time and efforts are reduced with Choleski direct method. Current waveform can be calculated for arbitrary voltage vaveform considering hysteresis effects.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.768-773
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• 2005

Among various joint ventures, International Construction Joint Ventures (ICJVs) have emerged as a popular approach worldwide to developing large scale projects through international participation. A model, based on economic analysis and represented by several hypotheses obtained from the analysis, will be developed. Furthermore, we will empirically test the hypotheses/model using Structural Equation Model (SEM). This research is expected to explain why there exist different organizational forms for ICJVs, and to develop a framework for choosing appropriate forms with respect to various characteristics of ICJVs.

• 유통과학연구
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• 제18권5호
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• pp.99-109
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• 2020

Purpose: This study aims to develop and empirically analyze a research model in order to comprehend the relationship among the service quality of market-wholesaler system, re-transaction intention, and recommendation intention of forwarder. Further, we suggest new six factors reflecting the service quality of market-wholesaler system and highlight market expansion of forwarder as a mechanism in the relationship. Research design, data and methodology: The authors developed the new scales measuring the service quality of market-wholesaler system (i.e. trade price, price fluctuation, payment receipt, settlement period, trade information, and customer service) and conducted a cross-sectional survey for 439 forwarders in a wholesale market. And then we performed a series of path analyses to test hypotheses. The hypotheses are as follows. [H1] The service quality of market-wholesaler system will positively affect forwarders' market expansion, [H2] Forwarders' market expansion will positively affect their re-transaction intention, [H3] Forwarders' market expansion will positively affect their recommendation intention, [H4] Forwarders' re-transaction intention will positively affect their recommendation intention. Results: The results showed that all the six factors for the service quality of market-wholesaler system were positively related to market expansion of forwarders. There was a differential effectiveness in the six factors of the service quality. More specifically, the positive effect of customer service factor was the strongest on market expansion of forwarders. And the respective effects of trade price, price fluctuation, settlement period, trade information factors were followed in order. The positive effect of payment receipt factor was the weakest on market expansion of forwarders. Also, market expansion of forwarders was positively related to their re-transaction intention and recommendation intention. Furthermore, market expansion of forwarders was indirectly related to recommendation intention through re-transaction intention as well. Conclusions: The research findings provide important theoretical and practical implications. This study is the first to attempt to test the perception of forwarders for the service quality of market-wholesaler system by developing and using the new scales. Also, there has been a sharp controversy about the effectiveness of market-wholesaler system. The findings support that market-wholesaler system would be activated by empirically verifying the effectiveness of the service quality on the various outcomes.

• 한국정보시스템학회지:정보시스템연구
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• 제15권4호
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• pp.23-53
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• 2006

The main purpose of this paper is to setup a integrated model and verify the integrated model for a customer loyalty in the internet shopping environments. The results of a structural equation model (SEM) using AMOS and LISREL include: First, hypothesis that Internet environment characteristics in outside factors has a positive effect on satisfaction, trust and commitment is partially supported. However, mutual communication to satisfaction, community to commitment and open-ubiquity to trust did not reveal a positive effect. Second, hypothesis that Internet showing mall environment has a positive effect on satisfaction is partially supported. However, transaction to commitment and transaction to trust did not reveal a positive effect. Third, hypothesis that relational benefits has a positive effect on both satisfaction and commitment is partially supported. However, confident honest to commitment and economic honest to trust did not reveal a positive effect. Forth, satisfaction trust and commitment have a strong effect upon loyalty. Fifth, satisfaction has a positive effect on trust and commitment. However, trust did not show a positive effect on commitment. Outside factors(Internet environment characteristics, showing mall characteristics, and relational benefit) partially revealed a positive effect on satisfaction trust, and commitment. Mediating variables such as satisfaction, trust, and commitment again have positive effect on loyalty. But, the relationship for trust to commitment did not reveal the significant effect in this study while other studies revealed significant effect.

• Industrial Engineering and Management Systems
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• 제15권1호
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• pp.63-76
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• 2016

Multiperiod portfolio selection problem attracts more and more attentions because it is in accordance with the practical investment decision-making problem. However, the existing literature on this field is almost undertaken by regarding security returns as random variables in the framework of probability theory. Different from these works, we assume that security returns are uncertain variables which may be given by the experts, and take absolute deviation as a risk measure in the framework of uncertainty theory. In this paper, a new multiperiod mean absolute deviation uncertain portfolio selection models is presented by taking transaction costs, borrowing constraints and threshold constraints into account, which an optimal investment policy can be generated to help investors not only achieve an optimal return, but also have a good risk control. Threshold constraints limit the amount of capital to be invested in each stock and prevent very small investments in any stock. Based on uncertain theories, the model is converted to a dynamic optimization problem. Because of the transaction costs, the model is a dynamic optimization problem with path dependence. To solve the new model in general cases, the forward dynamic programming method is presented. In addition, a numerical example is also presented to illustrate the modeling idea and the effectiveness of the designed algorithm.

• 한국컴퓨터정보학회논문지
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• 제17권8호
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• pp.145-161
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• 2012

본 연구에서는 정보시스템 관련 교육의 정도와 인터넷 활용 능력이 인지된 보안성 우려에 어떠한 영향을 미치며, 기술수용모델에 기반을 두어 이 세 변수가 온라인 거래 의도에는 어떻게 영향을 미치는지 살펴보고자 하였다. 또한 스마트 폰을 이용하여 필요로 하는 제품을 구매하는 사례가 증가하는 추세이므로 기존 인터넷을 이용할 경우와 스마트 폰을 이용할 경우로 구분하여 비교 분석하였다. 실증 분석 결과, 정보시스템 관련 교육의 정도, 인터넷 활용 능력, 인지된 보안성 우려는 인지된 유용성 및 인지된 사용 용이성을 매개로 하여 온라인 거래 의도에 유의한 영향을 미쳤다. 그리고 예상했던 것과 달리, 정보시스템 관련 교육을 많이 받을수록 해킹이나 프라이버시 침해 사례들을 더 많이 알게 되어 보안에 대해 더 우려하게 되며, 따라서 인터넷을 통한 거래가 많은 노력을 요구한다고 믿었다. 또한 정보시스템 관련 교육을 많이 받을수록 보안에 대해 더 우려하게 되므로, 인지된 보안성 우려는 인지된 유용성에 부(-)의 영향이 아니라 정(+)의 영향을 미쳤다. 마지막으로 정보시스템 관련 교육의 정도는 인터넷 거래의 유용성이나 인터넷 거래의 사용 용이성을 인지하는 것과는 관련이 있으나, 스마트 폰의 유용성이나 스마트 폰의 사용 용이성을 인지하는 것과는 관련이 없는 것으로 나타났다.

• 한국정보과학회논문지:정보통신
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• 제29권4호
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• pp.447-458
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• 2002

본 연구에서는 무선 인터넷 서비스를 위한 전송계층 프로토콜인 TCP, T/TCP와 WTP의 특징을 비교.분석한다. 우선 무선구간에 가장 적합한 WTP를 제한된 자원을 가진 무선 단말기상에 탑재하기 용이하도록 코루틴 모델을 기반으로 하나의 쓰레드로 구현하고 이를 Nokia, Kannel 그리고, WinWAP 의 기존 구현물과 상호 동작시켜 호환성을 검사한다. 그리고, 무선환경에서의 패킷손실을 잘 표현할 수 있는 길버트(Gilbert) 모델을 기반으로 구현물의 트랜잭션 성공률(throughput) 및 수행시간(system response time)을 측정하여 기존의 TCP, T/TCP와 비교한다. 그 결과, WTP는 트랜잭션 성공률과 수행 시간에 있어서 기존의 프로토콜에 비해 높은 성능을 보였다. 특히, 연속적인 에러가 발생하며 패킷손실률이 비교적 높을 때, WTP는 T/TCP와 TCP에 비해 매우 높은 트랜잭션 성공률을 나타냈으며, 10배 이상 빠른 수행 시간을 보였다. 이는 WTP가 다른 프로토콜에 비해 적은 개수의 패킷으로 하나의 트랜잭션을 수행하고 패킷 손실로 인한 타임아웃 발생 시, 타이머 값을 exponential backoff를 적용하지 않고 일정한 값을 유지하기 때문이다. 또한, 무선환경에 최적화된 WTP의 재전송 횟수를 결정하기 위한 실험을 통해, 가장 적절한 재전송 횟수가 5~6회임을 알 수 있었다.

• 한국정보시스템학회지:정보시스템연구
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• 제29권1호
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• pp.93-111
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• 2020

Purpose The purpose of this paper is to observe the relative priorities of importances among the modified versions of Block chain system, being based on AHP decision support model which should be also proposed in this paper. Design/methodology/approach Four versions modified from the beginning of Block chain were divided into Public& Permissionless, Private&Permissionless, Public&Permissioned and Private&Permissioned types. Five criteria for evaluating the four versions whether the version were suitable for Medical information system were introduced from five factors of Technologies Accept Model, which were Security, Availability, Variety, Reliability and Economical efficiency. We designed Decision support model based on AHP which would select the best alternative version suitable for introducing the Block chain technology into the medical information systems. We established the objective of the AHP model into finding the best choice among the four modified versions. First low layer of the model contains the five factors which consisted of Security, Availability, Variety, Reliability and Economical efficiency. Second low layer of the model contains the four modified versions which consisted Public&Permissionless, Private&Permissionless, Public&Permissioned and Private& Permissioned types. The structural questionnaire based on the AHP decision support model was designed and used to survey experts of medical areas. The collected data by the question investigation was analyzed by AHP analysis technique. Findings The importance priority of Security was highest among five factors of Technologies Accept Mode in the first layer. The importance priority of Private&Permissioned type was highest among four modified versions of Block chain technologies in second low layer. The second importance priority was Private&Permissionless type. The strong point of Private&Permissioned type is to be able to protect personal information and have faster processing speeds. The advantage of Private& Permissionless type is to be also able to protect personal information as well as from forging and altering transaction data. We recognized that it should be necessary to develop new Block chain technologies that would enable to have faster processing speeds as well as from forging and altering transaction data.

• 한국디지털건축인테리어학회논문집
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• 제12권1호
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• pp.89-98
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• 2012

While the housing transaction price of Seoul tends to be stagnant or declining in line with the housing market recession since 2007, the jeonse price keeps continual increase. Such flow of jeonse price change has a serious influence on ordinary person's housing stability seriously. Therefore, it is very meaningful in terms of social policy to analyze the trend of recent jeonse price change. This study aims to have an empirical analysis of structural characteristics of the trend of recent jeonse price change. After the review of various previous studies, this study selected housing jeonse price index, non-sold house quantity, jeonse vs. transaction price rate, and housing construction performance as analytical variables, and employed monthly time series resources from January 2007 to April 2011. As a result, when the housing supply reduced, the potential quantity for jeonse market reduced that occurred unbalance of supply and demand in jeonse market. In turn, it caused the increase of jeonse price. And, in case of jeonse vs. transaction price rate change, the rate increased which means the increase of required rate of return of invested demand. As such, the increase of market risk degenerates the investment sentiment which caused the reduction of quantity for jeonse market as a submarket.

• 인터넷정보학회논문지
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• 제6권1호
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• pp.73-84
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• 2005

ALTIBASE/sup TM/ 시스템은 메인 메모리를 주 저장장치로 사용하는 관계형 주기억장치 DBMS이다. 본 논문에서는 최근 데이터베이스 응용들의 요구사항으로 부각되고 있는 데이터베이스의 고가용성과 실시간 데이터베이스 시스템의 높은 트랜잭션 처리율을 동시에 보장하기 위하여 ALTIBASETM시스템의 구조 및 설계에 대하여 기술한다. 특히, 고가용성 보장을 위한 ALTIBASETM 시스템의 이중화 기능에 대하여 논의한다. 이중화 기법의 분류를 통해 다른 기법과의 비교를 하였으며, 이중화 관리를 위한 프로세스 구조 및 이중화 통신 모델, 프로토콜에 대하여 설명한다. 또한, 다양한 실험을 통하여 트랜잭션 처리율을 측정하였으며, 이중화 기능을 지원하기 위해 요구되는 오버헤드를 독립 시스템의 성능과 비교하여 측정하였다.