• Journal of Korean Institute of Industrial Engineers
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• v.23 no.1
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• pp.163-175
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• 1997

This paper presents the algorithm for finding the compensatory solution for fuzzy multiobjective nonlinear programming problem using $\gamma$-operator. The proposed algorithm can be applied to all cases with multiobjective problems since the interactive process with a decision maker is simple, various uncertainties involved on decision making are eliminated and all the objectives are well balanced. On the basis of proposed algorithm, an illustrative numerical example is presented.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.510-512
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• 1997

Measurement errors in a temperature measurement system are mainly due to the consisting elements' accuracies and the circuit parameters' changes following the environment variations such as temperature. Further, system's non-linearity makes the measurement accuracy worse, and accordingly a linearization method should be considered to avoid this worsening. In this study, an error-correction method and a linearization method are proposed and a system utilizing these methods is realized.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.251-260
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• 2004

As the importance and the need for network security is increased, many organization uses the various security systems. They enable to construct the consistent integrated security environment by sharing the vulnerable information among firewall, intrusion detection system, and vulnerable scanner. We construct the integrated security simulation environment that can be used by some security system model. In this paper, we have designed and constructed the general simulation environment of network security model composed of multiple IDSs agent and a firewall agent which coordinate by CNP (Contract Net Protocol). The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. We compare the selection algorithm in the CPN with the Fuzzy Controller for the effective method to select the agents.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.64-83
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• 2012

The number of smart phone users is rapidly growing due to recent increase in wireless Internet usage, development of a wide variety of applications, and activation of M2M (Machine to machine) services. Although the smart phone offers benefits of mobility and convenience, it also has serious security problems. To utilize M2M services in the smart phone, a flexible integrated authentication and access control facility is an essential requirement. To solve these problems, we propose a context-aware single sign-on and access control system that uses context-awareness, integrated authentication, access control, and an OSGi service platform in the smart phone environment. In addition, we recommend Fuzzy Logic and MAUT (Multi-Attribute Utility Theory) in handling diverse contexts properly as well as in determining the appropriate security level. We also propose a security system whose properties are flexible and convenient through a typical scenario in the smart phone environment. The proposed context-aware security system can provide a flexible, secure and seamless security service by adopting diverse contexts in the smart phone environment.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.144-156
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• 2023

Smart agriculture is a rapidly growing field that seeks to optimize crop yields and reduce risk through the use of advanced technology. A key challenge in this field is the need to create a comprehensive smart farm system that can effectively monitor and control the growth environment of crops, particularly when cultivating new varieties. This is where fuzzy theory comes in, enabling the collection and analysis of external environmental factors to generate a rule-based system that considers the specific needs of each crop variety. By doing so, the system can easily set the optimal growth environment, reducing trial and error and the user's risk burden. This is in contrast to existing systems where parameters need to be changed for each breed and various factors considered. Additionally, the type of house used affects the environmental control factors for crops, making it necessary to adapt the system accordingly. While developing such a framework requires a significant investment of labour and time, the benefits are numerous and can lead to increased productivity and profitability in the field of smart agriculture. We developed an AI platform for optimal control of facility houses by integrating data from mushroom crops and environmental factors, and analysing the correlation between optimal control conditions and yield. Our experiments demonstrated significant performance improvement compared to the existing system.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.470-477
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• 2009

Modular reconfigurable robots with physical docking capability easily adapt to a new environment and many studies are necessary for the modular robots. In this paper, we propose a vision-based fuzzy autonomous docking controller for the modular docking robots. A modular docking robot platform which performs real-time image processing is designed and color-based object recognition method is implemented on the embedded system. The docking robot can navigate to a subgoal near a target robot while avoiding obstacles. Both a fuzzy obstacle avoidance controller and a fuzzy navigation controller for subgoal tracking are designed. We propose an autonomous docking controller using the fuzzy obstacle avoidance and navigation controllers, absolute distance information and direction informations of robots from PSD sensors and a compass sensor. We verify the proposed docking control method by docking experiments of the developed modular robots in the various environments with different distances and directions between robots.

• Journal of Digital Convergence
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• v.14 no.7
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• pp.363-371
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• 2016

Technology evaluation for technology innovation of venture firms should take the rapidly changing corporate environment, the ambiguity of language used in evaluation, and the inaccuracy of evaluation index into consideration. In this paper, targeting the absorptive capacity and technological entrepreneurship which are typical evaluation factors of venture firms, an ACTEM model to calculate the importance, priority, and dynamic capability of factors, applying Fuzzy-AHP was proposed. The fuzzy theory was introduced to compensate for the ambiguity of cognitive judgments when calculating weighted values for the factors that made up an assessment scale. An assessment criteria framework for absorptive capacity, technological entrepreneurship, and dynamic capability, which were not considered in previous studies on the evaluation and measurement of technological prowess, so that the users could have a realistic alternative to choose. The study compared the ACTEM model with the old AHP assessment method and found that "knowledge acquisition" and "producing ability" were the highest in absorptive capacity and technological entrepreneurship, respectively, thus demonstrating its validity.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.368-374
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• 2010

Image segmentation is the basic step in the field of the image processing for pattern recognition, environment recognition, and context analysis. The Otsu's automatic threshold selection, which determines the optimal threshold value to maximize the between class scatter using the distribution information of the normalized histogram of a image, is the famous method among the various image segmentation methods. For the automatic threshold selection proposed by Otsu, it is difficult to determine the optimal threshold value by considering the sub-region characteristic of the image because the Otsu's algorithm analyzes the global histogram of a image. In this paper, to alleviate this difficulty of Otsu's image segmentation algorithm and to improve image segmentation capability, the original image is divided into several sub-images by using context fuzzy c-means algorithm. The proposed fuzzy Otsu threshold algorithm is applied to the divided sub-images and the several threshold values are obtained.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.149-159
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• 2019

Six sigma is an innovative management movement which provides improved business process by adapting the paradigm and the trend of market and customers. Suitable selection of six sigma project could highly reduce the costs, improve the quality, and enhance the customer satisfaction. There are existing studies on the selection of Six Sigma projects, but few studies have been conducted to select the correct project under an incomplete information environment. The purpose of this study is to propose the application of integrated MCDM techniques for correct project selection under incomplete information. The project selection process of six sigma involves four steps as follows: 1) determination of project selection criteria 2) calculation of relative importance of team member's competencies 3) assessment with project preference scale 4) finalization of ranking the projects. This study proposes the combination methods by applying group fuzzy Analytical Hierarchy Process (AHP), an easy defuzzified number of Trapezoidal Fuzzy Number (TrFN) and Grey Relational Analysis (GRA). Both of the weight of project selection criteria and the relative importance of team member's competencies can be evaluated by group fuzzy AHP. Project preferences are assessed by easy defuzzified scale of TrFN in case of incomplete information.)

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.3
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• pp.207-212
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• 2007

This paper aims to measure and evaluate the technical efficiency with two inputs and four outputs with the use of fuzzy DEA in Korean RCC/RSC. Especially, this paper included not only the marine accident data which occurred for the analysis in particular but also the possibility data of a potential marine accident by an Environmental Stress value and analyzed the technical efficiency. And in this paper, asymmetrical triangular fuzzy number is presented about inputs/ outputs data and a procedure is suggested for it's solution. The basic idea is to transform the fuzzy CCR model into a crisp linear programming problem by applying an alternative ${\alpha}$-cut approach. Also this paper propose a ranking method for fuzzy RCC/RSC using presented fuzzy DEA approach. The result, when ${\alpha}$-cut is 0.5, efficiency priority is found in the order of YS, BS, MP, TY, JJ, PH, US, IC, SC, DH, GS, TA, WD RCC/RSC. Finally, Inefficiency TA, WD RCC/RSC have to benchmarking with reference sets.