• 스마트미디어저널
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• 제5권2호
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• pp.84-89
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• 2016

스마트폰이나 태블릿 PC와 같이 GPS를 탑재한 모바일 기기 보급으로 위치 기반 정보는 모바일 생활의 필수 요소로 자리잡았다. 이제 사용자들은 더 나아가 개인별 성향에 따른 맞춤형 정보를 원하고 있다. 개인 맞춤형 추천을 위해서는 사용자의 행동을 이해하는 것이 필요한데 실생활에 많은 부분을 차지하고 있는 음식점 방문도 맞춤형 추천 서비스를 제공해 줄 수 있다. 본 논문에서는 음식점 방문에 대한 비슷한 태도를 보인 사용자를 추출한 후 방문했던 장소를 비교하여 추천하는 사용자 행동기반 다속성 태도 모델 기반의 장소 추천 모델을 연구한다. 다속성 태도점수를 산출하기 위해 피쉬바인(Fishbein) 방정식을 활용하고 피어슨 상관계수를 이용하여 사용자들이 방문했던 장소의 중 유사한 속성을 가진 장소를 추출했다. 그리고 그룹렌즈의 선호도 예측 알고리즘을 활용하여 추천 대상 장소를 선정하고 유클라디안 거리법으로 사용자에게 거리기반 장소를 추천하였다. 또한 실제 데이터를 이용한 실험을 통해 본 논문에서 제시한 시스템의 우수성도 입증하였다.

• 정보보호학회논문지
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• 제14권5호
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• pp.11-21
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• 2004

Client-to-Gateway 형태의 IPSec-VPN 시스템에서 IPSec-VPN 클라이언트에 대한 사용자 접근 제어를 위해서는 통상 ID/Password 검증 방식 또는 IPSec-VPN 클라이언트가 인증되면, 묵시적으로 IPSec-VPN 게이트웨이가 IPSec-VPN 클라이언트에 대한 사용자 접근 제어가 수행된 것으로 간주하는 묵시적 사용자 접근제어 방식이 있다. 그러나 ID/Password 검증방식은 ID/Password 정보의 전송 방법이 용이하지 않고, 묵시적 사용자 접근제어 방식은 보안상 취약점이 있기 때문에 보다 효과적인 사용자 접근제어 방안이 필요하다. 본 논문에서는 Client-to-Gateway 형태의 IPSec-VPN 시스템에서의 효과적인 사용자 접근제어 방안으로써, 속성 인증서를 이용한 사용자 접근제어 방안을 제안하고, 사용자 접근제어 엔진을 설계, 구현하였다. 본 논문에서 제안한 IPSec-VPN을 위한 사용자 접근제어 방안은 기존의 IPSec-VPN 시스템에 구현이 용이하고, 다른 IPSec-VPN 시스템과의 상호 호환성이 보장되는 장점을 가지고 있다. 또한 본 논문에서 설계, 구현한 사용자 접근제어 엔진은 속성 인증서를 이용한 임의적 접근제어, 역할기반 접근제어 뿐만 아니라, SSO(Single Sign-On) 기능을 제공할 수 있다.

• Journal of Information Technology Applications and Management
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• 제10권4호
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• pp.29-50
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• 2003

This research provide the basic information to enhance the user-orientedness of usability design guidelines for software products and an effective empirical guidance to classify design attributes of internet shopping mall sites. The results of analysis show that design attributes can be classified into the procedural attribute group, the shopping tool attribute group, the visual attribute group, linguistic attribute group, and others. The results show that shopping tool attribute group can be divided further into the search tool attribute group and purchase tool attribute group and that the visual attribute group can be divided further into the screen condition attribute group and the character legibility attribute group. The research reveals that when designers design software interfaces and features they should take the compound effect of a group of design attributes into consideration to enhance the usability of the system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2646-2659
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• 2017

Equipped with the advantages of flexible access control and fine-grained authentication, attribute based signcryption is diffusely designed for security preservation in many scenarios. However, realizing efficient key evolution and reducing the calculation costs are two challenges which should be given full consideration in attribute based cryptosystem. In this paper, we present a key-policy attribute based signcryption scheme (KP-ABSC) with delegated computation and efficient key updating. In our scheme, an access structure is embedded into user's private key, while ciphertexts corresponds a target attribute set. Only the two are matched can a user decrypt and verify the ciphertexts. When the access privileges have to be altered or key exposure happens, the system will evolve into the next time slice to preserve the forward security. What's more, data receivers can delegate most of the de-signcryption task to data server, which can reduce the calculation on client's side. By performance analysis, our scheme is shown to be secure and more efficient, which makes it a promising method for data protection in data outsourcing systems.

• 대한안전경영과학회지
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• 제14권3호
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• pp.283-289
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• 2012

In the future, smartphone convergences are not only based on the on/offline integration, but also with the integration between mobile communications and broadcasts. Therefore, there is a need to search for new direction of mobile device that enables variety user applications that are different from the existing size and application issue. The aim of this research is to improve user interface of smartphone's functional attribute. We study on the analysis of smartphone's functional attribute by AHP. The survey results in this paper showed that the most preferable attribute of smartphone among the 8 was the wireless internet 25.3%, followed by messaging 20% and application 19.8%, which totaled to 62.5%. But the samples used were mostly limited to those aged 20 through 30. So the results are not considered as a representative preference of all smartphone users, and should be considered otherwise before materializing them to a product. Therefore, for the more liable results the further research should be conducted to gather data from a variety of users of all ages, and the functional attribute should be analysed through QFD.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.323-342
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• 2021

Personal health records (PHRs) is an electronic medical system that enables patients to acquire, manage and share their health data. Nevertheless, data confidentiality and user privacy in PHRs have not been handled completely. As a fine-grained access control over health data, ciphertext-policy attribute-based encryption (CP-ABE) has an ability to guarantee data confidentiality. However, existing CP-ABE solutions for PHRs are facing some new challenges in access control, such as policy privacy disclosure and dynamic policy update. In terms of addressing these problems, we propose a privacy protection and dynamic share system (PPADS) based on CP-ABE for PHRs, which supports full policy hiding and flexible access control. In the system, attribute information of access policy is fully hidden by attribute bloom filter. Moreover, data user produces a transforming key for the PHRs Cloud to change access policy dynamically. Furthermore, relied on security analysis, PPADS is selectively secure under standard model. Finally, the performance comparisons and simulation results demonstrate that PPADS is suitable for PHRs.

• 한국컴퓨터정보학회논문지
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• 제28권1호
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• pp.27-38
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• 2023

본 논문에서는 시간의 흐름에 따라 새로운 데이터를 지속적으로 학습하고 성장할 수 있는 연속 학습 기반 대화형 AI 에이전트를 제안한다. 연속학습 기반 대화형 AI 에이전트는 태스크 관리자 (Task Manager), 사용자 속성 추출(User Attribute Extraction), 자동 확장 지식 그래프(Auto-growing Knowledge Graph), 크게 3가지 요소로 구성된다. 태스크 관리자는 사용자와의 대화에서 새로운 데이터를 발견하면 이전에 학습한 지식을 통해 새로운 태스크를 생성한다. 사용자 특성 추출 모델은 새로운 태스크에서 사용자의 특성을 추출하고, 자동 확장 지식 그래프는 새로운 외부 지식을 지속적으로 학습할 수 있도록 한다. 한정된 데이터셋을 기반으로 학습된 기존 대화형 AI 에이전트와 달리, 본 논문에서 제안하는 방법은 지속적인 사용자의 특성과 지식 학습을 기반으로 대화를 가능하게 한다. 연속학습 기술이 적용된 대화형 AI 에이전트는 사용자와의 대화가 축적될수록 개인 맞춤형 대응이 가능하며, 새로운 지식에도 대응이 가능하다. 본 논문에서는 시간에 따른 대화 생성 모델의 성능 변화 실험을 통해 제안하는 방법의 가능성을 검증한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1516-1528
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• 2015

We introduce attribute set based signature (ASBS), a new cryptographic primitive which organizes user attributes into a recursive set based structure such that dynamic constraints can be imposed on how those attributes may be combined to satisfy a signing policy. Compared with attribute based signature (ABS), ASBS is more flexible and efficient in managing user attributes and specifying signing policies. We present a practical construction of ASBS and prove its security in the standard model under three subgroup decision related assumptions. Its efficiency is comparable to that of the most efficient ABS scheme.

• 경영과학
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• 제25권1호
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• pp.1-9
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• 2008

This paper investigates the R&D project portfolio selection problem. Despite its importance and impact on real world projects, there exist few practical techniques that help construct an non-dominated portfolio for a decision makers satisfaction. One of the difficulties constructing the portfolio is that such project portfolio problem is, in nature, a multi-attribute decision-making problem, which is an NP-hard class problem. This paper investigates the R&D project portfolio selection problem. Despite its importance and impact on real world projects, there exist few practical techniques that help construct an non-dominated portfolio for a decision makers satisfaction. One of the difficulties constructing the portfolio is that such project portfolio problem is, in nature, a multi-attribute decision-making problem, which is an NP-hard class problem. In order to obtain the non-dominated portfolio that a decision maker or a user is satisfied with, we devise a user-interface algorithm, in that the user provides the maximum/minimum input values for each project attribute. Then the system searches the non-dominated portfolio that satisfies all the given constraints if such a portfolio exists. The process that the user adjusts the maximum/minimum values on the basis of the portfolio found continues repeatedly until the user is optimally satisfied with. We illustrate the algorithm proposed, and the computational results show the efficacy of our procedure.

• 디지털산업정보학회논문지
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• 제10권2호
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• pp.83-89
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• 2014

An increasing number of children are now using the Internet. They are starting at a younger age, using a variety of devices and spending more time online. It becomes an important problem to protect the children in online environment. The Internet can be a major channel for their education, creativity and self-expression. However, it also carries a spectrum of risks to which children are more vulnerable than adults. In order to solve these problems, we suggested a binding model of user attributes for enhanced user authentication. We also studied the requirements and prerequisites of a binding model of user attributes. In this paper we described the architecture of binding model of user attributes and showed the effectiveness of the suggested model using simulation. This model can be utilized to enhanced user authentication and service authorization.