• 지능정보연구
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• 제17권1호
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• pp.153-169
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• 2011

오늘날 기업의 마케팅에 있어 인터넷 환경의 이용은 필수적이며, 좀 더 효율적인 마케팅을 위해 다양한 방법들이 시도되고 있다. 기업들은 온라인마케팅을 통해 다양한 경품이나 포인트 등의 마케팅 비용을 사용하는 것으로 제품이나 서비스를 알려왔다. 특히 웹 2.0의 등장과 함께 기업은 좀 더 적극적으로 고객과 소통하기 위한 노력을 아끼지 않고 있다. 고객들은 회사의 웹사이트에 개인정보를 제공하는 형태로 회원가입을 하여 회사가 제공하는 혜택을 받으면서 제품 광고나 프로모션에 참여하게 된다. 그러나 온라인 마케팅의 운영측면에서 볼 때 현재의 회원관리 시스템은 회원의 모집과 운영에 있어서 효과적이지 못한 문제점이 나타나고 있다. 온라인 환경에서의 고객들은 오프라인 환경에서보다 명확한 자아를 덜 드러내기 때문에 회원가입 과정 중에 일부 악의적인 목적을 가진 고객들이 주변인의 개인정보를 이용하거나 조작하여 중복 아이디를 만들어 활동할 수 있게 된다. 이러한 취약점을 이용하여 중복가입 회원들은 고객들에게 돌아가야 할 경품이나 포인트 등을 가로채어 기업 마케팅 비용의 효율을 떨어뜨리고 있다. 그러나 증가하고 있는 마케팅 비용에 비해 중복회원의 선별 및 이들에 대한 제재를 위한 효과적 방법은 뚜렷하게 제시되지 않고 있다. 따라서 이를 방지하기 위한 체계적인 회원관리 시스템이 요구된다. 본 연구에서는 소셜 네트워크 분석 기법을 이용한 중복회원 식별방법을 제시하고 실제 온라인 고객데이터를 이용하여 그 효과성을 검증한다. 소셜 네트워크는 노드들의 관계를 표현하며, 관계의 유무, 방향 및 강도 등으로 연결 형태를 나타낼 수 있다. 특히 컴포넌트 분석방법은 소셜 네트워크 하위그룹 분석방법으로 네트워크의 내부 그룹을 구분하여 다양한 네트워크 특성을 식별하여 준다. 회원정보 분석에 있어 컴포넌트 분석방법은 전제회원 데이터 내의 의미 있는 정보를 이루고 있는 그룹을 식별하게 된다. 본 연구는 H사의 서로 다른 회원가입 기준을 가진 3개 웹사이트의 회원정보를 사용하여 진행되었다. 제안된 분석방법은 중복회원의 실체를 분석하고 시각화함으로써, 실무적인 측면에서 효율적인 마케팅의 증진을 도울 뿐만 아니라 신뢰성 있는 고객의 의견수렴 및 의사결정에도 도움이 될 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1732-1733
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• 2011

This paper presents observer-based controller design for interval type-2 fuzzy system with staircase membership approximation. In type-2 fuzzy case, membership function is itself fuzzy set itself. Thus, type-2 fuzzy system can deal with parametric uncertainties of nonlinear system by capturing the uncertainties in membership function. Likewise, stabilization condition of type-2 fuzzy system is derived from quadratic Lyapunov function, and it goes to linear matrix inequality. Furthermore, in this paper, to relax the conservativeness of stabilization condition, staircase membership function approximating method is applied. Observer-based control method is adopted to control system which has some unmeasurable states. To prove suitability of our proposed method, numerical example is presented.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.153-156
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• 2001

Fuzzy controllers also show good performance In case of the systems being nonlinear and difficult to solve. But these fuzzy controllers have problems which have to decide suitable rules and membership functions. In general we decide those using the heuristic methods or the experience of experts. Therefore, many researchers have applied genetic algorithms to make fuzzy rule automatically. In this paper, we suggest a new coding method and a new crossover method to maintain the good fuzzy rule base and the shape of membership

• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.48-57
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• 1999

Applications of thresholding technique are based on the assumption that object and background pixels in a digital image can be distinguished by their gray level values. For the segmentation of more complex images, it is necessary to resort to multiple threshold selection techniques. This paper describes a new method for multiple threshold selection of gray level images which are not clearly distinguishable from the background. The proposed method consists of three main stages. In the first stage, a probability distribution function for a gray level histogram of an image is derived. Cluster points are defined according to the probability distribution function. In the second stage, fuzzy partition matrix of the probability distribution function is generated through the fuzzy clustering process. Finally, elements of the fuzzy partition matrix are classified as clusters according to gray level values by using max-membership method. Boundary values of classified clusters are selected as multiple threshold. In order to verify the performance of the developed algorithm, automatic inspection process of ball grid array is presented.

• Smart Structures and Systems
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• 제26권6호
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• pp.797-807
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• 2020

Due to the influence of nonlinearity and time-variation, it is difficult to establish an accurate model of concrete frame structures that adopt active controllers. Fuzzy theory is a relatively appropriate method but susceptible to human subjective experience to decrease the performance. This paper proposes a novel artificial intelligence based EBA (Evolved Bat Algorithm) controller with machine learning matched membership functions in the complex nonlinear system. The proposed affine transformed membership functions are adopted and stabilization and performance criterion of the closed-loop fuzzy systems are obtained through a new parametrized linear matrix inequality which is rearranged by machine learning affine matched membership functions. The trajectory of the closed-loop dithered system and that of the closed-loop fuzzy relaxed system can be made as close as desired. This enables us to get a rigorous prediction of stability of the closed-loop dithered system by establishing that of the closed-loop fuzzy relaxed system.

• 산업경영시스템학회지
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• 제35권3호
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• pp.155-162
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• 2012

This study proposes an integrated approach that uses both a fuzzy service FMEA (failure mode and effect analysis) and HOQ (house of quality) matrix algebra in designing and improving a service system. The fuzzy service FMEA methodology applies the customer satisfaction to the fuzzy RPN model. We fuzzify only the service satisfaction that consist in two failure factors, intangible service and tangible service, to more effectively assess the customer satisfactions on service encounters. Proposed fuzzy service satisfactions with triangle membership function are defuzzified by using the Fuzzy Inference System, and these are eventually identified the ranks on the potential fail points. HOQ matrices are constructed from cause-effect relationships. It is possible for these relationship matrix to find a linear approximation solution on the engineering attributes. Thus, in order to demonstrate how the proposed methods work, practical sample of the A/S part in S Electronic Co. provides for the ranking of the engineering attributes which has been successfully implemented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권7호
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• pp.2399-2413
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• 2021

A recommendation system is an information filter tool, which uses the ratings and reviews of users to generate a personalized recommendation service for users. However, the cold-start problem of users and items is still a major research hotspot on service recommendations. To address this challenge, this paper proposes a high-efficient hybrid recommendation system based on Fuzzy C-Means (FCM) clustering and supervised learning models. The proposed recommendation method includes two aspects: on the one hand, FCM clustering technique has been applied to the item-based collaborative filtering framework to solve the cold start problem; on the other hand, the content information is integrated into the collaborative filtering. The algorithm constructs the user and item membership degree feature vector, and adopts the data representation form of the scoring matrix to the supervised learning algorithm, as well as by combining the subjective membership degree feature vector and the objective membership degree feature vector in a linear combination, the prediction accuracy is significantly improved on the public datasets with different sparsity. The efficiency of the proposed system is illustrated by conducting several experiments on MovieLens dataset.

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.676-687
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• 2015

Path planning algorithms are used to allow mobile robots to avoid obstacles and find ways from a start point to a target point. The general path planning algorithm focused on constructing of collision free path. However, a high continuous path can make smooth and efficiently movements. To improve the continuity of the path, the searched waypoints are connected by the proposed polynomial interpolation. The existing polynomial interpolation methods connect two points. In this paper, point groups are created with three points. The point groups have each polynomial. Polynomials are made by matching the differential values and simple matrix calculation. Membership functions are used to distribute the weight of each polynomial at overlapped sections. As a result, the path has $G^2$ continuity. In addition, the proposed method can analyze path numerically to obtain curvature and heading angle. Moreover, it does not require complex calculation and databases to save the created path.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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• pp.354-360
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• 1998

In general, it is very difficult to find optimal fuzzy rules by experience when a system is dynamical and/or complex. Futhermore proper fuzzy partitioning is not deterministic and there is no unique solution. Therefore we propose a new design method of an optimal fuzzy logic controller, that is a co-evolutionary genetic algorithm finding optimal fuzzy rule and proper membership functions at the same time. We formalize the relation between fuzzy rules and membership functions in terms of fitness. We review the typical approaching methods to co-evolutionary genetic algorithms , and then classify them by fitness relation matrix. Applications of the proposed method to a path planning problem of autonomous mobile robots when moving objects exist are presented to demonstrate the performance and effectiveness of the method.

• 전기학회논문지
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• 제61권10호
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• pp.1508-1512
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• 2012

This paper presents a relaxed stability condition for continuous-time affine fuzzy system using fuzzy Lyapunov function. In the previous studies, stability conditions for the affine fuzzy system based on quadratic Lyapunov function have a conservativeness. The stability condition is considered by using the fuzzy Lyapunov function, which has membership functions in the traditional Lyapunov function. Based on Lyapunov-stability theory, the stability condition for affine fuzzy system is derived and represented to linear matrix inequalities(LMIs). And slack matrix is added to stability condition for the relaxed stability condition. Finally, simulation example is given to illustrate the merits of the proposed method.