• Communications for Statistical Applications and Methods
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• 제10권3호
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• pp.879-894
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• 2003

We evaluated the efficiencies of applying attribute selection methods and prior discretization to supervised learning, modelled by C4.5 and Naive Bayes. Three databases were obtained from UCI data archive, which consisted of continuous attributes except for one decision attribute. Four methods were used for attribute selection : MDI, ReliefF, Gain Ratio and Consistency-based method. MDI and ReliefF can be used for both continuous and discrete attributes, but the other two methods can be used only for discrete attributes. Discretization was performed using the Fayyad and Irani method. To investigate the effect of noise included in the database, noises were introduced into the data sets up to the extents of 10 or 20%, and then the data, including those either containing the noises or not, were processed through the steps of attribute selection, discretization and classification. The results of this study indicate that classification of the data based on selected attributes yields higher accuracy than in the case of classifying the full data set, and prior discretization does not lower the accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3274-3297
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• 2021

Permission delegation is an important research issue in access control. It allows a user to delegate some of his permissions to others to reduce his workload, or enables others to complete some tasks on his behalf when he is unavailable to do so. As an ideal solution for controlling read access on outsourced data objects on the cloud, Ciphertext-Policy Attribute-Based Encryption (CP-ABE) has attracted much attention. Some existing CP-ABE schemes handle the read permission delegation through the delegation of the user's private key to others. Still, these schemes lack the further consideration of granularity and traceability of the permission delegation. To this end, this article proposes a flexible and fine-grained CP-ABE key delegation approach that supports white-box traceability. In this approach, the key delegator first examines the relations between the data objects, read permission thereof that he intends to delegate, and the attributes associated with the access policies of these data objects. Then he chooses a minimal attribute set from his attributes according to the principle of least privilege. He constructs the delegation key with the minimal attribute set. Thus, we can achieve the shortest delegation key and minimize the time of key delegation under the premise of guaranteeing the delegator's access control requirement. The Key Generation Center (KGC) then embeds the delegatee's identity into the key to trace the route of the delegation key. Our approach prevents the delegatee from combining his existing key with the new delegation key to access unauthorized data objects. Theoretical analysis and test results show that our approach helps the KGC transfer some of its burdensome key generation tasks to regular users (delegators) to accommodate more users.

• 방송공학회논문지
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• 제14권3호
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• pp.280-287
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• 2009

IPTV(Internet Protocol Television)기술은 통신과 방송의 새로운 융합 기술로 다양한 양방향 TV 서비스를 제공한다. 이러한 서비스를 제공받기 위해서는 TV에 연결된 셋톱박스 (STB, Set-Top Box)와 정당한 가입자의 스마트카드 간의 상호 인증이 이루어져야 한다. 본 논문에서는 한 조직 내에서 직위나 부서 등과 같은 특성(속성) 값들에 따라, IPTV 서비스를 이용할 수 있도록 하는 속성기반 인증 기법을 제안하고, 제안하는 기법이 안전함을 보인다. 제안하는 기법에서 사용자는 자신의 아이디, 패스워드와 스마트카드를 이용하여 인증 메시지를 생성하는데, 이 때 자신에게 속한 다양한 속성을 이용할 수 있기 때문에 가입자는 한 번의 등록으로 속성에 따라 다양한 서비스를 제공받을 수 있다는 장점이 있다. 우리가 아는 한도 내에서는, 본 논문에서 제안하는 기법이 IPTV 환경이 조성된 어떤 조직에도 적용할 수 있는 최초의 속성인증 기법이다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.143-146
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• 2004

In a situation that rank order information on attribute weights is captured, two solution approaches are presented. An exact solution approach via interaction with a decision-maker pursues progressive reduction of a set of non-dominated alternatives by narrowing down the feasible attribute weights set. In approximate solution approach, on the other hand, three categories of approximate methods such as surrogate weights method, the dominance value-based decision rules, and three classical decision rules are presented and their efficacies in terms of choice accuracy are evaluated via simulation analysis. The simulation results indicate that a method, which combines an exact solution approach through interactions with the decision-maker and the dominance value-based approach is recommendable in a case that a decision is not made at a single step under imprecisely assessed weights information.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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• pp.207-210
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• 2003

In this paper, we explore a new data mining capability that is based on Quantitative Attribute and Time Series. Our solution procedure consists of two steps. First, We derive an algorithm to contain the Quantitative Attribute into a set of candidate item. Second, We redefine the concepts of confidence and support for composite association rules. It is shown that proposed methode is very advantageous and can lead to prominent performance improvement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.1993-1995
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• 2001

The subject of nonlinear control is an important area of automatic control. The behavior of nonlinear systems is much more complex. If the operating range of a control system is small, and if the involved nonlinearities are smooth, then the control system may be resonably approximated by a set of linear differential equations. This paper presents the deadbeat response attribute of some nonlinear systems, e.g., magnetic levitation, pendulum, van der pol oscillator etc.. The studied results through the computer simulation are shown a promising attribute of deadbeat response that the outputs of the systems are reached relatively fast the steady state.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1215-1224
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• 2018

Interval-valued neutrosophic hesitant fuzzy set (IVNHFS) is an extension of neutrosophic set (NS) and hesitant fuzzy set (HFS), each element of which has truth membership hesitant function, indeterminacy membership hesitant function and falsity membership hesitant function and the values of these functions lie in several possible closed intervals in the real unit interval [0,1]. In contrast with NS and HFS, IVNHFS can be more flexibly used to deal with uncertain, incomplete, indeterminate, inconsistent and hesitant information. In this study, I propose the novel correlation coefficient of IVNHFSs and my paper discusses its properties. Then, based on the novel correlation coefficient, I develop an approach to deal with multi-attribute decision-making problems within the framework of IVNHFS. In the end, a practical example is used to show that the approach is reasonable and effective in dealing with decision-making problems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3339-3352
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• 2016

In ciphertext-policy attribute-based encryption (CP-ABE) scheme, a user's secret key is associated with a set of attributes, and the ciphertext is associated with an access policy. The user can decrypt the ciphertext if and only if the attribute set of his secret key satisfies the access policy specified in the ciphertext. In the present schemes, access policy is sent to the decryptor along with the ciphertext, which means that the privacy of the encryptor is revealed. In order to solve such problem, we propose a CP-ABE scheme with hidden access policy, which is able to preserve the privacy of the encryptor and decryptor. And what's more in the present schemes, the users need to do excessive calculation for decryption to check whether their attributes match the access policy specified in the ciphertext or not, which makes the users do useless computation if the attributes don't match the hidden access policy. In order to solve efficiency issue, our scheme adds a testing phase to avoid the unnecessary operation above before decryption. The computation cost for the testing phase is much less than the decryption computation so that the efficiency in our scheme is improved. Meanwhile, our new scheme is proved to be selectively secure against chosen-plaintext attack under DDH assumption.

• 한국인터넷방송통신학회논문지
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• 제14권2호
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• pp.107-113
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• 2014

러프집합에서 식별불능의 관계와 근사공간의 개념을 이용해서 의사결정표로부터 최적화된 정보를 유도하게 된다. 그러나 일반적으로 결정표에서 데이터의 중복이나 비일관성은 피할 수 없기 때문에 속성의 중요성은 지식의 감축에서 매우 중요한 개념이다. 속성의 중요성에 대한 대수학적인 정의는 도메인중의 완전한 부분집합에 대한 해당 속성이 주는 영향을 고려하는 것이고, 정보이론적인 정의는 도메인 중의 불완전한 부분집합에 대한 해당 속성이 주는 영향을 고려하는 것이다. 따라서 속성 중요성은 정보이론적인 관점의 정의와 대수학인 관점의 정의가 분명하게 차이가 있다. 본 논문에서는 정보시스템의 조건속성과 결정속성에 포함될 수 있는 정보를 최적화하기 위한 정보이론적인 척도로써 러프집합을 이용한 조건부 정보엔트로피를 제안하고 그 효용성을 보인다.

• 한국조리학회지
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• 제16권2호
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• pp.15-30
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• 2010

본 연구는 방한 일본 관광객의 국내 외식업체 이용을 중심으로 서비스 실패의 심각성과 통제성이 고객의 지각된 공정성, 신뢰, 만족, 충성도에 미치는 영향에 대하여 연구함으로써, 분석 결과를 요약하면 다음과 같다. 첫째, 통제성과 심각성은 지각된 공정성에 부(-)의 영향을 미칠 것으로 기대되었으나, 모두 부(-)의 영향을 미치지 않는 것으로 나타났다. 둘째, 절차적 공정성은 신뢰에, 상호작용 공정성과 분배적 공정성은 신뢰와 만족에 유의한 영향을 미치는 것으로 나타났다. 셋째, 신뢰는 만족에, 만족은 충성도에 각각 유의한 영향을 미치는 것으로 나타났다. 이러한 연구결과를 토대로 외식기업들은 서비스 실패의 심각성과 통제성을 확인하기보다는 서비스 실패에 대한 회복 프로세스를 빠르게 실행해야 하며, 서비스 실패에 대한 고객의 회복 단계를 신뢰, 만족, 충성의 순서로 설정하고, 이러한 프로세스를 거쳐 빠르게 실행되고 있는지 확인해야 할 것이다.