• 지능정보연구
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• 제22권3호
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• pp.113-127
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• 2016

협업 필터링(Collaborative Filtering)은 유용성과 정교성 면에서 가장 성공적인 추천 알고리즘으로 평가받으며 산업계나 학계에서 많이 활용 및 연구되고 있지만, 기본적으로 사용자들이 평가한 점수에만 기반하여 추천결과를 생성하는 한계점이 있다. 이에 본 연구는 사용자가 상품을 구매할 때 자신이 신뢰하는 타인의 추천을 더 적극적으로 수용할 것이라는 점에 착안하여, 사용자의 평점 외에 사용자 간 신뢰관계를 소셜네트워크분석으로 분석한 결과를 추가로 반영하는 추천 알고리즘들을 제안하였다. 구체적으로 본 연구에서는 소셜네트워크분석에서 네트워크 내의 중심적 위치를 나타내는 척도인 내향 및 외향 중심성을 활용하여 사용자 간 유사도를 산출하는 알고리즘들과 사용자 신뢰 네트워크를 탐색하여 추천 대상이 되는 사용자가 직접 간접적으로 신뢰하는 사용자의 평가점수를 보다 높게 반영하는 알고리즘을 제안한 뒤 그 성능을 비교해 보았다. 실제 데이터에 적용하여 분석한 결과, 사용자 신뢰 네트워크의 내향 중심성 지수를 조건 없이 적용한 경우에는 오히려 정확도의 감소만을 야기하는 것으로 나타났고, 일정 임계치 이상의 외향 중심성을 갖는 사용자에 한해 내향 중심성 지수를 고려한 추천 알고리즘은 전통적인 협업 필터링에 비해 약간의 정확도 개선이 이루어짐을 확인할 수 있었다. 아울러, 사용자 신뢰 네트워크를 기반으로 탐색하는 알고리즘이 가장 우수한 성능을 보이는 것을 알 수 있었으며, 전통적인 협업 필터링과 비교해서도 통계적으로 유의한 수준의 정확도의 개선이 이루어짐을 확인할 수 있었다.

• 한국멀티미디어학회논문지
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• 제18권5호
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• pp.620-630
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• 2015

This research suggests a load balancing method for a volume rendering system which supports concurrent users. When concurrent users use a volume rendering server system, the computational resources are occupied by a particular user by turns because each process consumes the computational resources as much as possible. In this case, the previous method shows acceptable throughput but the latency is increased for each user. In this research, we suggest a method to improve the latency without performance degradation. Each process makes concessions for taking the resources according to the number of users connected to the system. And we propose a load balancing method in the dynamic situation in which the number of users can vary. Using our methods, we can improve the latency time for each user.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권1호
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• pp.45-52
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• 2015

Although researchers have proposed various recommendation systems, most recommendation approaches are for single users and there are only a small number of recommendation approaches for groups. However, TV programs or movies are most often viewed by groups rather than by single users. Most recommendation approaches for groups assume that single users' profiles are known and that group profiles consist of the single users' profiles. However, because it is difficult to obtain group profiles, researchers have only used synthetic or limited datasets. In this paper, we report on various group recommendation approaches to a real large-scale dataset in a TV domain, and evaluate the various group recommendation approaches. In addition, we provide some guidelines for group recommendation systems, focusing on home group users in a TV domain.

• Journal of Information Technology Applications and Management
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• 제19권2호
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• pp.233-247
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• 2012

There are so many studies on perceived risk and purchasing intention. But the results of those studies were inconsistent; some studies showed the positive effect of perceived risk on purchasing intention; others showed the negative effect. This research supposed that the inconsistence of studies resulted from the difference of group innovativeness and set up research hypotheses : among users from the lower innovativeness group, perceived risk has a negative effect on purchasing intention, but from the higher group, perceived risk has a positive effect on purchasing intention. We compared Internet shopping mall users of South Korea representing low innovativeness with those of China representing high innovativeness. The results provided that among South Korean users, perceived risk had the statistically insignificant negative effect on purchasing intention, but among Chinese users, it had the statistically significant positive effect on purchasing intention. Additionally, this study found that perceived risk influenced users' fun which in turn influenced purchasing intention.

• 한국공간정보시스템학회 논문지
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• 제11권2호
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• pp.54-62
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• 2009

This paper proposes a framework for personal location based services with personal life content, for example diaries, schedules and to-do lists. A lot of Internet users are recording their personal experiences and knowledge as text and other digital media on the network. Our proposed tool provides users with an environment to store personal records with related place attributes, and to retrieve these personal records at the right place. There are two applications on this tool, a place-enhanced blog and a LBS client on a mobile phone. The place enhanced blog provides users with blog interfaces for inputting place information. The place rem inder is a browser for spatial data on the place enhanced blog. Users can generate place information by writing personal records on their blog. Furthermore, using the LBS client, other users can retrieve personal records at the appropriate spots.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3458-3464
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• 2010

최근 빠른 주기로 많은 양의 새로운 정보가 생성되기 때문에, 사용자 중심의 정보 검색을 위해 RSS라는 신디케이션 기술이 제공되고 있다. RSS는 새롭게 갱신된 콘텐츠를 자동으로 전달받을 수 있어 신규 정보를 찾기 위해 사이트에 지속적으로 접근하지 않아도 된다. 본 논문에서는 블로그 정보 검색을 위해 RSS 문서의 주소를 수집하는 수집기와 사용자 질의에 따른 RSS 문서의 순위결정 방법을 제안한다. 제안하는 정보 검색 기법을 이용하면 사용자가 RSS 문서를 효과적으로 검색할 수 있다.

• 한국실내디자인학회논문집
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• 제14권5호
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• pp.18-25
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• 2005

This study examined the current space usage of postpartum care center and postpartum mother's assessment of postpartum care center. This study was conducted questionnaire web survey. 220 women who used postpartum care center were surveyed. The data were analyzed by using SPSS Program for Win 12.0. Frequency, percentage, mean were used. The major findings were as follows: The postpartum care center was consisted of 5 areas such as living area, sanitary area, public area, service area and administration area. Living and public area were mainly occupied, but service area was insufficient. The users showed high satisfaction with mother room, and low satisfaction with nursing room and shower room. The users complained of size of mother room, collaboration with others in shower room and toilet. The users wanted guest meeting room for users' privacy of living room. The users wanted service area such as massage room, fitness room, physical care roon.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.2254-2271
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• 2011

Access control in dynamic environments needs the ability to provide more access opportunities of information to users, while also ensuring protection information from malicious users. Trust and risk are essential factors and can be combined together in access control decision-making to meet the above requirement. In this paper, we propose the combination of the trust and risk in access control to balance information accessibility and protection. Access control decision is made on the basis of trustworthiness of users and risk value of permissions. We use potential relations between users and relations between permissions in access control. Our approach not only provides more access opportunities for trustworthy users in accessing permissions, but also enforces traditional access control constraints such as Chinese Wall policy and Separation of Duty (SoD) of Role-Based Access Control (RBAC) model in an effective way.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2008년도 추계학술대회 및 정기총회
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• pp.415-419
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• 2008

In this study, an empirical research based on survey has been performed to study the influence of user expectation to user satisfaction of commercial and open source DBMSs. According to the survey results, word-of-mouth and past experiences influence significantly to user expectation, and price influences to user expectation only for commercial DBMS users. The results show that the expectancy disconfirmation influences significantly to user satisfaction. Expectation and satisfaction levels of commercial DBMS users are higher significantly than those of open source DBMS users. However, expectancy disconfirmation of open source DBMS users is higher than that of commercial DBMS users.

• 한국IT서비스학회지
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• 제8권4호
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• pp.187-199
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• 2009

Content services for silver users on the ubiquitous technologies are getting attention as a new business model, monitoring users in real-time on the real-world and/or cyber-world. A lot of business and service model have been developed to apply silver or elder user. This study explained a state-of-the-art silver IT service to innovative services for users, ranging from home and finance to support for healthcare and living. Due to the variation of subtle terminologies, this study was conducted to restructure an adaptive terminology including some definitions. Current silver IT service model has been evaluated from the technical, functional, and business analyst, and its suitability has also been expressed in a proposed model and service. The purpose of this study was to propose a systematic approach of new IT service business model for silver users. A proposed model was described to explain the feasibility of the silver IT industry.