• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.502-506
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• 2013

The cash flow forecasting is normally done by contractors in construction industry at early stages of the project for contractual decisions. The decision making in such situations involve uncertainty about future cash flows and assessment of working capital requirements gains more importance in projects constrained by cash. The traditional approach to assess the working capital requirements is deterministic in and neglects the uncertainty. This paper presents an alternate approach to assessment of working capital requirements for contractor based on fuzzy set theory by considering the uncertainty and ambiguity involved at payment periods. Statistical methods are used to deal with the uncertainty for working capital curves. Membership functions of the fuzzy sets are developed based on these statistical measures. Advantage of fuzzy peak working capital requirements is demonstrated using peak working capital requirements curves. Fuzzy peak working capital requirements curves are compared with deterministic curves and the results are analyzed. Fuzzy weighted average methodology is proposed for the assessment of peak working capital requirements.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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• pp.278-282
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• 2001

The discovery of tacit knowledge from domain experts is one of the most exciting challenges in today\`s knowledge management. The nature of decision knowledge in determining the quality a firm\`s short-term liquidity is full of abstraction, ambiguity, and incompleteness, and presents a typical tacit knowledge extraction problem. In dealing with knowledge discovery of this nature, we propose a scheme that integrates both knowledge elicitation and knowledge discovery in the knowledge engineering processes. The knowledge elicitation component applies the Verbal Protocol Analysis to establish industrial cases as the basic knowledge data set. The knowledge discovery component then applies fuzzy clustering to the data set to build a fuzzy knowledge based system, which consists of a set of fuzzy rules representing the decision knowledge, and membership functions of each decision factor for verifying linguistic expression in the rules. The experimental results confirm that the proposed scheme can effectively discover the expert\`s tacit knowledge, and works as a feedback mechanism for human experts to fine-tune the conversion processes of converting tacit knowledge into implicit knowledge.

• 패션비즈니스
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• 제12권4호
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• pp.46-55
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• 2008

The purpose of this study is to provide the effective internet marketing communication strategy as marketing tools by analyzing the web sites of young casual fashion brands. We've selected 19 young casual fashion brands in 3 department stores and made the classification standard - advertising, promotion, public relation(PR), customer management - and analysed the young casual fashion brands according to 4 classification standard on the web sites. As a result of study, it is found that 19 young casual brands' web sites put an emphasis on activity of customer management and promotion in general. However, they did not conduct the PR and advertising actively compared with other parts. Especially, the promotion strategy occupies more parts than any other parts through the variety of membership card's services. Also they are sending e-mails or providing 1:1(FAQ/Q&A) board to the members as a customer management to be able to help to communicate with customer through the web site.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.176-183
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• 2005

The theory of signal detection has been applied to a wide range of practical situation for a long time, including sonar detection, air traffic control and so on. In general, in this theory, sensitivity parametric index d' and bias parametric index $\beta$ are used to evaluated the performance of vigilance. These indices use observer's response "hit" and "false alarm" to explain and evaluate vigilance, but not considering reaction time. However, the reaction time of detecting should be considered in measuring vigilance in some supervisory tasks such as unlimited monitoring tasks (e.g., supervisors in nuclear plant). There are some researchers have used the segments of reaction time to generate a pair of probabilities of hit and false alarm probabilities and plot the receiver operating characteristic curve. The purpose of this study was to develop a quantitative vigilance-measuring model by fuzzy sets, which combined the concepts of hit, false alarm and reaction time. The model extends two-values logic to multi-values logic by membership functions of fuzzy sets. A simulated experiment of monitoring task in nuclear plant was carried out. Results indicated that the new vigilance-measuring model is more efficient than traditional indices; the characteristics of vigilance would be realized more clearly in unlimited monitoring task.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.152-156
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• 2001

인터넷의 활성화에 힘입어 멀티캐스트 응용을 위한 다양한 연구가 진행되어져오고 있다. 본 논문에서는 OFT(One-way Function Trees)를 사용한 안전한 멀티캐스트 키분배 프로토콜을 제안한다. 제안하는 프로토콜은 DKMP(Distributed Key Management Protocol)방식과 CKMF(Centralized Key Management Protocol)방식 각각의 특성 및 장점을 살린 혼합 방식으로, DKMP의 특성인 그룹 키 생성시 모든 멤버의 참여를 보장하는 측면과 CKMP의 특성인 키 관리 및 프로토콜 설계의 용이성을 고려하여 설계하였다. 또한 제안된 프로토콜은 그룹 비밀키 생성시 해쉬 함수와 비트단위 XOR 연산만을 이용하기 때문에 멤버들의 연산 오버헤드를 줄일 수 있어, 멤버의 가입 및 탈퇴가 빈번히 발생하는 동적인 환경에 효율적으로 활용될 수 있다.

• 디지털산업정보학회논문지
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• 제8권2호
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• pp.67-79
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• 2012

As credit cards are more convenient than cash of heavy and volume, they are used widely in on_line (internet) and off_line in nowadays. A head of the economically active population had 4.8 credit cards in the third quarter 2011. The economically active population in their 20's and 30's may have more than 10 credit cards. If the membership card and point card are included, the count rise to 20 cards in a man. Therefore, the their purse become thick by several cards. Nowadays, the smart-phone is widely used. Therefore, a lot of credit cards are come in smarty-phone from analog form to digital form. In this paper, we study a method of digital credit cards management in smart-phone. For the method, the hardware need in small and existing system have a few change. All kinds of credit cards are used in smarty-phone. We compare the method with Moneta card and NFC of smarty-phone. The digital credit cards feature a light, safety and convenience of mobile users in several ways.

• 한국통신학회논문지
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• 제34권10B호
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• pp.1004-1012
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• 2009

다양한 무선 네트워크상에서 멀티미디어 멀티캐스트 서비스에 대한 기대가 날로 높아지고 있는데, 이는 IP 멀티캐스트 그룹 관리가 무선 환경에서도 효과적이면서 효율적으로 동작하여야 함을 가정하고 있다. 하지만, IGMPv3/MLDv2는 무선상에서 신뢰성이 없는 시그널링, 느린 상태의 전환, 낮은 주파수당 전송 효율, Bulk Report, Dormant 모드를 방해하는 등의 문제가 있어 무선 환경에서 그대로 사용하기에 비효율적이다. 본 논문에서는 무선 호스트 에이전트(Wireless Host Agent; WHA)를 도입하여 무선 링크 사이에서의 시그널링을 줄이고 그룹 관리의 효율성과 신뢰성을 높이는 기법을 소개한다. 또한 시그널링 비용 모델을 제시하고, 그 성능을 비교하였다.

• 한국환경복원기술학회지
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• 제12권1호
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• pp.1-12
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• 2009

The purpose of this study is to discovered assessment items for improving athletic efficiency and management of golf courses. Through this, the study intended to provide basic data for creating competitive golf courses and management. Important assessment items were selected by inducing preliminary assessment items and conducting a preliminary survey and a main survey for specialists through a theoretical study. For the survey results studied, reliability and average value for importance were calculated using SPSS/PC Window Release 12.0. As assessment of importance by assessment area, in athletic efficiency assessment, course management level was the highest, followed by fairness of games and operation of games. In management assessment, importance of service level, information management, facility management, management of game assistants, etc. were high. As assessment of importance by assessment item, it was found that 'variety of golf shot' and 'the length of a course' were important in course layout. Also 'start interval among teams' and 'disturbance of play' were assessed as important items in game operation, while 'fair reservation' and 'rounding rotation time' were important in fairness of games. In addition, in information management, 'kind service of golf course staffs' and 'prompt reservation and notification' were found to be important assessment items. In facility management, all assessment indexes were over 4.0, which means all of them are important for quality of golf course and competitiveness. In membership service, 'appropriate price of goods for sale' and 'service for members' were relatively important assessment items. Further, in management of game assistants, 'qualifications and skillfulness of game assistants' was assessed as a very important index. Although the current study only selected important items to assess excellent golf courses, it is necessary to apply the study results to the actual sites and verify them for golf course both at domestic and abroad.

• Journal of Construction Engineering and Project Management
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• 제8권4호
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• pp.1-24
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• 2018

In the last decade, the use of Building Information Modeling (BIM) as a new technology has been applied with traditional Computer-aided design implementations in an increasing number of architecture, engineering, and construction projects and applications. Its employment alongside construction management, can be a valuable tool in helping move these activities and projects forward in a more efficient and time-effective manner. The traditional stakeholders, i.e., Owner, A/E and the Contractor are involved in this BIM system that is used in almost every activity of construction projects, such as design, cost estimate and scheduling. This article extracts major features of the application of BIM from perspective of participating BIM components, along with the different phrases, and applies to them a logistic analysis using a fuzzy performance tree, quantifying these phrases to judge the effectiveness of the BIM techniques employed. That is to say, these fuzzy performance trees with fuzzy logic concepts can properly translate the linguistic rating into numeric expressions, and are thus employed in evaluating the influence of BIM applications as a mathematical process. The rotational fuzzy models are used to represent the membership functions of the performance values and their corresponding weights. Illustrations of the use of this fuzzy BIM performance tree are presented in the study for the uninitiated users. The results of these processes are an evaluation of BIM project performance as highly positive. The quantification of the performance ratings for the individual factors is a significant contributor to this assessment, capable of parsing vernacular language into numerical data for a more accurate and precise use in performance analysis. It is hoped that fuzzy performance trees and fuzzy set analysis can be used as a tool for the quality and risk analysis for other construction techniques in the future. Baldwin's rotational models are used to represent the membership functions of the fuzzy sets. Three scenarios are presented using fuzzy MEAN, AND and OR gates from the lowest to intermediate levels of the tree, and fuzzy SUM gate to relate the intermediate level to the top component of the tree, i.e., BIM application final performance. The use of fuzzy MEAN for lower levels and fuzzy SUM gates to reach the top level suggests the most realistic and accurate results. The methodology (fuzzy performance tree) described in this paper is appropriate to implement in today's construction industry when limited objective data is presented and it is heavily relied on experts' subjective judgment.

• 한국멀티미디어학회논문지
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• 제19권5호
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• pp.948-956
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• 2016

Many franchise stores are in the surrounding. These stores offer many membership services. But, small traders do not provide much customer management service. For example, non-franchised cafes provide the services through paper coupons. However, most of paper coupons are available only in one store that issued the coupon. Besides, these coupons are in stamp format. Due to the absence of customers' management service, it is hard for small traders to attract customers compared to the franchise. Therefore, in this paper, We had implemented a mobile application, and applied to new customer management service in order to increase the price competitiveness of small traders. This service issues electronic coupon through a mobile app. customers can receive a relatively large amount of discount, and a deadline of coupons are short. When customers use coupons, new coupons are issued at the same time. This structure can be powerful means to lead customers' frequent visit. Small traders can gain a lot of regular customers by using this service.