• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1065-1068
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• 2007

본 논문에서는 무선 멀티 홉 네트워크에서 시스템 성능을 높이기 위한 효율적인 핸드오버 결정 알고리즘을 제안한다. 기존의 핸드오버 결정에 대한 연구들은 대부분 싱글 홉 환경에서 이루어졌고, 802.16 환경에서 중요한 이슈가 되는 사용자의 QoS 요구를 고려하지 않고 있다. 제안하는 알고리즘은 기지국(BS)으로의 전송 시간을 기준으로 하는 경로 결정 방법과 전송 시간, 사용자의 QoS 요구, 기지국의 트래픽 로드를 입력 값으로 하는 퍼지 로직 기반(Fuzzy Logic based)의 핸드오버 알고리즘을 포함한다. 제안하는 핸드오버 결정 알고리즘은 802.16j 환경의 특성을 고려하였으며, 기존의 SINR 기반의 방식에 비해 전송 시간, 세션 당 핸드오버 횟수, 전송 끊김 횟수가 5%~30% 향상되는 결과를 가진다.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.45-49
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• 2024

Blockchain has gone beyond the proof-of-concept level and is converging with various industries and fields, moving toward the service development and commercialization stage. However, although various blockchain technologies and services are emerging, their development is quite slow and their widespread application to various industries is difficult. Accordingly, it is necessary to identify areas with high introduction utility when applying blockchain services in actual industries and to develop a method to evaluate the utility of blockchain services for this purpose. This paper proposes a framework for evaluating the utility of blockchain services using a multi-criteria decision-making model. Through a case study on the utility evaluation of blockchain services, the proposed framework was applied to domestic and foreign blockchain services to evaluate its utility and verify its applicability. It is expected that the proposed framework will be able to identify industrial and functional characteristics where actual blockchain services can be introduced and demonstrate effective utility and can be used to develop blockchain services in various industrial fields.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1017-1020
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• 2007

컴퓨터의 생활 전반에 걸친 영향으로, 컴퓨터는 우리 생활 속에서 빼놓을 수 없는 하나의 정보 매체로 자리 매김 되었다. 하지만 그 이면에는 컴퓨터를 이용한 전산망 침해 행위, 전자기록 위.변조, 각종 음란물 유통, 바이러스 제작 유포 등 많은 위험들이 우리를 위협하고 있다. 그래서 컴퓨터를 사용한 범죄 행위를 탐지하는 방법에 대한 관심이 높아지고 있다. 또한 각종 범죄 행위는 인터넷을 통한 범죄가 늘고 있어, 네트워크 정보를 통한 포렌식에 관한 연구가 활발하다. 하지만, 매일 많은 양의 패킷을 분석하는 것은 많은 전문 인력과 비용이 소요된다. 본 논문에서는 의사결정나무를 이용한 패킷분석을 통하여 네트워크 포렌식의 정보를 추출하는 방법을 제안한다.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.5 s.45
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• pp.41-52
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• 2005

Using the variable control gain scheme on the basis of fuzzy-based decision-making process, Fuzzy supervisory control (FSC) technique exhibits better control performance than linear control technique with one static control gain. This paper demonstrates the effectiveness of the FSC technique by evaluating the robust performance of the FSC technique under the presence of uncertainties in the models and the excitations. Robust performance of the FSC system is compared with that of optimally designed LQG control system for the benchmark cable-stayed bridge presented by Dyke et al. Parameter studies on the robust performance evaluation are carried out by varying the stiffness of the bridge model as well as the magnitudes of several earthquakes with different frequency contents. From the comparative study of two control systems, FSC system shows the enhanced control performance against various magnitudes of several earthquakes while maintaining lower level of power required for controlling the bridge response. Especially, FSC system clearly guarantees the improved robust performance of the control system with stable reduction effects on the seismic responses and slight increases in total power and stroke for the control system, while LQG control system exhibits poor robust performance.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.103-113
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• 2003

This paper shows alternative route search and preference route search for the traffic route search, and proposes the use of the fuzzy non-additive controller by the application of AHP(analytic hierarchy process). It is different from classical route search and notices thinking method of human. Appraisal element, weight of route is extracted from basic of the opinion gathering for the driving expert and example of route model was used for the finding of practice utility. Model evaluation was performed attribute membership function making of estimate element, estimate value setting, weight define by the AHP, non additive presentation of weight according to $\lambda$-fuzzy measure and Choquet fuzzy integral. Finally, alternative route search was possible to real time traffic route search for the well variable traffic environment, and preference route search showed reflection of traffic route search disposition for the driver individual. This paper has five important meaning. (1)The approach is similar to the driver's route selection decision process. (2)The approach is able to control of route appraisal criteria for the multiple attribute. (3)The approach makes subjective judgement objective by a non additive. (4)The approach shows dynamic route search for the alternative route search. (5)The approach is able to consider characteristics of individual drivers attributed for the preference route search.

• Journal of Service Research and Studies
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• v.7 no.4
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• pp.51-68
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• 2017

Financial technology (FinTech) is an emerging financial service sector include innovations in financial literacy and investment, retail banking, education, and crypto-currencies like bitcoin. One of the crucial branch of financial technology-third-party payment (TPP) is undergoing rapid growth, with online/mobile systems replacing offline financial systems. System quality and user attitudes are key perceptions driving third-party payment usage, the importance of these perceptions, however, may be different with countries as users' thinking varies from country to country. Thus, the purpose of this study is to elaborate how factors differ from China to Korea by drawing on the unified theory of acceptance and use of technology (UTAUT2). Additionally, this study also aims to propose a multi-attribute evaluation of the third-party online payment system based on analytic hierarchy process (AHP), fuzzy sets and technique for order performance by similarity to ideal solution (TOPSIS), to examine the relative importance of the perceptions influencing new technology adoption intention. The results showed that the price value has the most significant influence on Chinese perceptions, while the perceived credibility has the most significant effect on Korean perceptions. Sub-criteria also performs different results to Chinese and Korean third-party online payment system.

• Korean Journal of Remote Sensing
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• v.11 no.3
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• pp.49-60
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• 1995

Features of geological lineaments generally play an important role at the data interpretation concerned geological processes, mineral exploration or natural hazard risk estimation. However, there are intrinsically discordances between lineaments-related features extracted from surficial geological syrvey and those from satellite imagery;nevertheless, any data set contained those information should not be considred as less meaningful within their own task. For the purpose of effective utilization task of extracted lineaments, the mathematical scheme, based on fuzzy set theory, for practical integration of various types of rasterized data sets is studied. As a real application, the geological map named Homyeong sheet(1:50,000) and the Landset TM imageries covering same area were used, and then lineaments-related data sets such as lineaments on the geological map, lineaments extracted from a false-color image composite satellite, and major drainage pattern were utilized. For data fusion process, fuzzy membership functions of pixel values in each data set were experimentally assigned by percentile, and then fuzzy algebraic sum operator was tested. As a result, integrated lineaments by this well-known operator are regarded as newly-generated reasonable ones. Conclusively, it was thought that the implementation within available GISs, or the stand-alone module for general applications of this simple scheme can be utilized as an effective scheme can be utilized as an effective scheme for further studies for spatial integration task for providing decision-supporting information, or as a kind of spatial reasoning scheme.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.1
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• pp.116-126
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• 2006

The purpose of this study is to analyze the growing course of Busan, Gimhae and Jinhae and further find patterns of the urban growth. This study shows that patterns of the urban growth differ from city to city, being influenced by the city's characteristics. Acknowledging this fact would help the decision maker to determine the developing plan of the urban. The methodology for this study is as follows; Fuzzy set concept is applied to minimize the data loss. At the same time, the AHP is used to give a relative weight to each factor. In order to be able to manage the change based on the dynamic model and time, Cellular Automata is introduced to simulate the growth of urban. The results show that the pattern of Gimhae's and Jinhae's growth is the same, whereas that of Busan is different from them. That is to say, each city has regional characteristics. And the pattern of the urban growth is influenced by the regional conditions of the city.

• Journal of Environmental Impact Assessment
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• v.4 no.2
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• pp.105-121
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• 1995

Nitrate contamination problems from groundwater supplies have been documented throughout many countries in the world, including Korea. Nitrate salts can induce methemoglobinemia and possibly human gastric cancer. In farmed areas. intensive agricultural activities have caused a major increase in nitrate loading to groundwater. To determine whether decision makers must take farm-management actions to control the increase of groundwater nitrate concentration and to decide the timing of such actions, it is important to predict groundwater Nitrate levels that would result over time from various farm-management practices. However, the input values such as soil, fertilizer and crop data) used to examine the effects of various farm-management practices on groundwater nitrate level are usually uncertain due to a lack of available information. In this paper. the ease of a community with a nitrate water quality problem is illustrated to examine the effects of various farm-management practices and to show bow to perform, with uncertain information. a time-series analysis on groundwater nitrate levels that would result. from each farm-management practice.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.253-258
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• 2012

In this thesis, I categorize expression of context data required for context data inference according to five Ws and one H(5W1H) in Ubiquitous computing environment and infer superordinate context by combining context data of 4W1H with inferred context of why. This thesis suggests that we categorize specific context and service according to 6W2H added Whom(specific data or service) and How much (accuracy), and determine proper services for specific contexts by introducing the concept of rough set for expression and inference of categorized contexts and inaccurate knowledge. Since there is an limitation of the set of 0 and 1 when concerned with accuracy of services, I introduce the concept of fuzzy set. To provide users with the most appropriate service by ridding of unnecessary properties through the process of reduction, I also use the concept of rough set.