• 한국문헌정보학회지
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• 제47권3호
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• pp.97-117
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• 2013

본 연구는 그룹 연구 과제를 수행하는 과정에서 게시된 온라인 토론 게시물을 분석하여, 그룹원들의 협동적 정보행태를 밝히는 데 목적이 있다. 본 연구에서는 Kuhlthau의 ISP 모형과 Yue와 He의 CIB 모형을 기반으로 대학원생들의 그룹 연구 과제 수행에서 나타나는 협동적 정보행태와 정서적 측면, 필요로 하는 협동 및 지원유형의 관계를 연구하였다. 본 연구의 결과는 그룹 연구 과제에서의 협동적 정보행태에 대한 이해에 도움을 주며, 협동적 정보 이용자를 위한 정보활용능력 교육에 활용할 수 있을 것으로 기대된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4684-4705
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• 2019

Collaborative filtering recommender systems are vulnerable to shilling attacks in which malicious users may inject biased profiles to promote or demote a particular item being recommended. To tackle this problem, many robust collaborative recommendation methods have been presented. Unfortunately, the robustness of most methods is improved at the expense of prediction accuracy. In this paper, we construct a robust Bayesian probabilistic matrix factorization model for collaborative filtering recommender systems by incorporating the detection of user anomaly rating behaviors. We first detect the anomaly rating behaviors of users by the modified K-means algorithm and target item identification method to generate an indicator matrix of attack users. Then we incorporate the indicator matrix of attack users to construct a robust Bayesian probabilistic matrix factorization model and based on which a robust collaborative recommendation algorithm is devised. The experimental results on the MovieLens and Netflix datasets show that our model can significantly improve the robustness and recommendation accuracy compared with three baseline methods.

• 정보관리학회지
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• 제30권3호
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• pp.183-205
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• 2013

협동적 정보행태에 대한 연구의 중요성이 대두됨에 따라, 다양한 문제 상황에서 협동적 정보행태에 대한 많은 수의 연구가 수행되어 왔고, 그를 바탕으로 여러 모형이 제안되고 있다. 본 연구에서는 Prekop(2002), Reddy와 Jansen(2008), Shah(2008), Karunakaran, Spence와 Reddy(2010), Yue와 He(2010) 등이 제안한 5개의 협동적 정보행태 모형들을 비교 분석하고, 그 결과를 토대로 향후 협동적 정보행태 연구의 지향점을 논의하였다. 협동적 정보행태에 대한 기존 연구의 한계를 극복하고 후속 연구를 위한 전략은 다음과 같다. 첫째, 다양한 이용자 그룹 및 문제 상황에 따른 협동적 정보행태의 연구가 요구되며, 둘째, 협동적 정보행태에서 나타나는 다양하고 복잡한 측면을 다루는 총체적인 연구의 접근이 필요하고, 셋째, 제안된 협동적 정보행태 모형에 대한 논의와 일반화의 검증이 필요하다. 특히, 국내외 환경을 반영한 경험적 연구를 바탕으로 제안된 모형이 수정 보완되어야 할 것이다.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2004년도 추계학술대회
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• pp.203-210
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• 2004

Due to the explosion of e-commerce, recommender systems are rapidly becoming a core tool to accelerate cross-selling and strengthen customer loyalty. There are two prevalent approaches for building recommender systems - content-based recommending and collaborative filtering. Collaborative filtering recommender systems have been very successful in both information filtering domains and e-commerce domains, and many researchers have presented variations of collaborative filtering to increase its performance. However, the current research on recommendation has paid little attention to the use of time related data in the recommendation process. Up to now there has not been any study on collaborative filtering to reflect changes in user interest. This paper proposes dynamic fuzzy clustering algorithm and apply it to collaborative filtering algorithm for dynamic recommendations. The proposed methodology detects changes in customer behavior using the customer data at different periods of time and improves the performance of recommendations using information on changes. The results of the evaluation experiment show the proposed model's improvement in making recommendations.

• Asia pacific journal of information systems
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• 제18권4호
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• pp.83-103
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• 2008

In the new web based learning environment which has recently emerged, a variety of new learning objectives and teaching methods suited to this learning environment have been adopted. Recently, web based project-based learning methods have received a great deal of attention from those wishing to improve learning performance. The objective of this study is to identify the impact of characteristics of communication media and instruction behavior on collaborative interaction and project performance through web based group projects. The characteristics of communication media were divided into richness, flexibility, and ease of use, and the characteristics of instruction behavior were divided into support and expression, which are independent variables. Collaborative interaction as a mediate variable, was divided into information sharing and negotiation. Project performance was the dependent variable. To verify the proposed research model empirically, an experiment was conducted in which learners participated in on-line and off-line courses with group projects. The group project was conducted virtual product development(VPD), and designed a web-site about the VPD. At the end of the project, a survey was conducted. Of the 270 students, 239 responded. The students were assigned to groups of 3 or 4 members, and represented different genders and levels of computer competence. The reliability, validity, and correlation of research variables were analyzed using SPSS 14.0, and the measurement model and the structural goodness-of-fit of the research model were verified through SEM analysis using Lisrel 8.54. We found important results as follows; First, richness and ease of use has positive impacts on each of sharing information and negotiation. This suggests that richness and ease of use are useful in sharing information which is related to the task and agreeing in opinions among group members. However, flexibility has not positive impacts on sharing information and negotiation. This implies that there is no great difference in performance of PC and information literacy of user. Second, support and expression of instructor have positive impacts on sharing information and negotiation. This indicates that instructors play an important role in encouraging learners to participate in the project and communicating with them, sharing information related to the project, making a resonable decision and finally leading them to improve a project performance. Third, collaborative interaction has a positive impact on project performance. This result shows that if the ability to share information and negotiate among students was improved then a project performance would be improved as well. Recently, in the state of revitalized web based learning, it is opportune that web-based group project is practically conducted, and the impact of characteristics of communication media and characteristics of instruction behavior on sharing information, negotiating among group members and improving a project performance is verified. On the basis of these results, we propose that forms of learning, such as web based project, could be one of solution which is to enforce interaction among learners, and ultimately improve learning performance. Moreover web-based group project is able to make up for a weakness which makes it difficult to make interpersonal relations or friendship among learners in computer mediated communication or web based learning.

• 지능정보연구
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• 제12권4호
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• pp.1-14
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• 2006

본 연구는 상품추천을 위해 필요한 고객 선호도 추정모형(Customer Preference Estimation Model)을 제안하고, 이러한 선호도 추정결과에 따른 선호도 정보를 이용하여 궁극적으로 상품추천의 성과를 제고시키기 위한 방법을 제시하였다. 즉, 제품에 대한 고객 선호 영향요인들과 고객 선호도와의 관계를 모형화 함으로써 고객 선호도를 보다 더 정확히 추정할 수 있는 새로운 선호도 추정모형을 제안하였다. 이 제안모형은 선호도 영향요인들의 상대적인 가중치를 선호도 최적화 학습을 통해 도출함으로써, 보다 정확한 선호도 측정을 가능하게 해 준다. 한편, 이 모형의 타당성을 검증하기 위해서 본 연구에서는 가상서점 고객들을 대상으로 고객 선호도 정보를 수집한 후, 본 제안모형을 적용했을 때의 협업 필터링의 추천성과와 사전가중치 부여방식인 기존 선호도 계산식을 이용했을 경우의 추천성과를 비교 분석하였다. 이에 대한 실증분석 결과는 본 연구에서 제안한 선호도 추정모형을 적용했을 때의 협업 필터링의 성과가 기존 선호도 계산방식을 적용했을 때의 협업 필터링의 성과보다 더 우수한 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.501-509
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• 2019

In this paper a body-centered cubic(BCC) crystal plasticity model based on microscopic dislocation mechanism is introduced and numerically implemented. The model is coupled with irradiation effect via tracking dislocation loop evolution on each slip system. On the basis of the model, uniaxial tensile tests of unirradiated and irradiated RPV steel(take Chinese A508-3 as an example) at different temperatures are simulated, and the simulation results agree well with the experimental results. Furthermore, crystal plasticity damage is introduced into the model. Then the damage behavior before and after irradiation is studied using the model. The results indicate that the model is an effective tool to study the effect of irradiation and temperature on the mechanical properties and damage behavior.

• Journal of Information Science Theory and Practice
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• 제8권3호
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• pp.30-46
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• 2020

This research aimed (1) to study and analyze the ability of current information retrieval (IR) systems based on views of information behavior (IB), and (2) to propose a conceptual framework for an IB model based on the collaboration between the system and user, with the intent of developing an IR system that can apply intelligent techniques to enhance system efficiency. The methods in this study consisted of (1) document analysis which included studying the characteristics and efficiencies of the current IR systems and studying the IB models in the digital environment, and (2) implementation of the Delphi technique through an indepth interview method with experts. The research results were presented in three main parts. First, the IB model was categorized into eight stages, different from traditional IB, in the digital environment, which can correspond to all behaviors and be applied to with an IR system. Second, insufficient functions and log file storage hinder the system from effectively understanding and accommodating user behavior in the digital environment. Last, the proposed conceptual framework illustrated that there are stages that can add intelligent techniques to the IR system based on the collaboration perspective between the user and system to boost the users' cognitive ability and make the IR system more user-friendly. Importantly, the conceptual framework for the IB model based on the collaboration perspective between the user and system for IR assisted the ability of information systems to learn, recognize, and comprehend human IB according to individual characteristics, leading to enhancement of interaction between the system and users.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2008년도 춘계학술대회
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• pp.493-517
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• 2008

The purpose of this research is to identify effect of communication strategy as effectively communication method which is decreasing Internet Web site users' perceived information privacy concerns as important factor affecting to positive behavior or behavioral intentions on long-term relational outcome perspectives. This study suggests alternatives concepts and causal relationship about information privacy issues. First, it addressed collaborative communication strategy (CCS) model of effective communication method for Web site's IPP to users. Second, it provided comparing and integrating streams of information privacy research on long-term relational outcomes perspective. Third, it assessed effectiveness of Web site's IPP on organization legitimacy ensured continuous survival of organization. A research model was proposed and subsequent hypotheses were empirically tested with partial least square (PLS) based on 684 responses from the users of 21 Internet Website among entirely finance, recruit, portal /e-store Web site. It was learned that CCS(as a communication method) and relationship quality(representing long-term relational outcomes)was positively associated with decreasing user's IPC more than privacy risk. Also, legitimacy to information privacy practice positively associated with willingness to information providing more than negative effect of IPC. Lastly, their association strength was partially moderated by the type of real information sensitivity.

• 정보관리학회지
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• 제22권1호
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• pp.209-228
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• 2005

본 연구는 정보시스템의 효율적인 협력적 상호작용을 가능하게 하는 정보자원의 관리 방안을 마련하기 위한 연구프로젝트의 선행 작업으로 진행되었다. 우선 본 연구는 협력적인 문제해결과정에서 발생되는 도움제공자와 도움수여자 간에 유의한 행위적${\cdot}$인지적 패턴이 존재하는지를 파악하고, 더 나아가 문제해결 상황에 대한 평가와 행위적${\cdot}$인지적 패턴 간에 유의한 관계가 존재하는지를 살펴보았다. 상황을 인지이동이 발생한 특정 시공간의 집합으로 보는 Dervin의 의미형성이론에 근거하였으며, IT관련 문제해결을 위해 정보전문가의 도움을 받았던 36명의 이용자와 이용자에게 도움을 제공한 경험이 있는 22명의 정보전문가를 대상으로 심층적인 인터뷰를 실시하였다. 협력적 문제해결 행위 모형을 제시하였고 정보시스템의 상호작용성을 향상시키기 위해 시스템 설계시 고려할 점을 제안하였다.