• 대한전기학회논문지:전력기술부문A
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• 제54권8호
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• pp.375-387
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• 2005

This paper presents an application of parallel Genetic Algorithm-Tabu Search (GA-TS) algorithm to search an optimal solution of a service restoration in distribution systems. The main objective of service restoration of distribution systems is, when a fault or overload occurs, to restore as much load as possible by transferring the do-energized load in the out of service area via network reconfiguration to the appropriate adjacent feeders at minimum operational cost without violating operating constraints, which is a combinatorial optimization problem. This problem has many constraints with many local minima to solve the optimal switch position. This paper develops parallel GA-TS algorithm for service restoration of distribution systems. In parallel GA-TS, GA operators are executed for each processor. To prevent solutions of low fitness from appearing in the next generation, strings below the average fitness are saved in the tabu list. If best fitness of the GA is not changed for several generations, TS operators are executed for the upper $10\%$ of the population to enhance the local searching capabilities. With migration operation, best string of each node is transferred to the neighboring node after predetermined iterations are executed. For parallel computing, we developed a PC cluster system consists of 8 PCs. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through ethernet switch based fast ethernet. To show the validity of the proposed method, proposed algorithm has been tested with a practical distribution system in Korea. From the simulation results, we can find that the proposed algorithm is efficient for the distribution system service restoration in terms of the solution quality, speedup, efficiency and computation time.

• 대한치과보철학회지
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• 제48권2호
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• pp.135-142
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• 2010

연구목적: 최근CAD/CAM으로 제작한 지르코니아 코어의 변연적합도에 관한 연구가 많이 진행되었지만, 여러 종의CAD/CAM 시스템의 변연 뿐만 아니라 내면적합도까지 상호 비교한 연구는 아직 미흡한 실정이다. 따라서 본 연구에서는 3종의CAD/CAM 시스템으로 제작한 전치부 단일 치아 지르코니아 코어의 변연 및 내면적합도를 Replica technique을 이용해 평가하고자 하였다. 연구 재료 및 방법:3종의CAD/CAM 시스템 (Cerasys $system^{(R)}$, KaVo $Everest^{(R)}$, $LAVA^{TM}$)을 이용하여, 시스템 별로 5개씩의 단일치아 지르코니아 코어를 제작하였다. 제작된 지르코니아 코어를 레플리카 테크닉 (Replica Technique)을 이용해 복제하고 복제된 시편을 협설, 근원심으로 정중앙을 절단하여 변연 및 내면의 간격을 측정하였다. Measuring microscope ($AXIO^{(R)}$)를 이용하여 50배 확대하여 촬영하고 $I-Solution^{(R)}$을 이용하여 측정하였고, ANOVA를 이용하여 통계적으로 분석하였다. 결과:지르코니아코어의 평균 변연간격은 $Cerasys^{(R)}$가 $84.74{\pm}27.57{\mu}m$, KaVo $Everest^{(R)}$가 $80.23{\pm}21.07{\mu}m$, $Lava^{TM}$가 $96.37{\pm}11.45{\mu}m$이었고 평균내면간격은각각 $Cerasys^{(R)}$는 $94.99{\pm}18.74{\mu}m$, KaVo $Everest^{(R)}$는 $92.31{\pm}25.18{\mu}m$, $LAVA^{TM}$는 $94.99{\pm}18.74{\mu}m$이었으며, 세 시스템간의 변연 및 내면간격의 평균적인 적합도에서 통계적 유의차는 없었다. 변연 및 내면간격의 비교에서는 KaVo $Everest^{(R)}$가 $LAVA^{TM}$보다 전반적으로 내면간격이 작은 것으로 보였다 (P< .05). 내면간격 중 절단부위의 간격은 세 시스템에서 공통적으로 다른 부위보다 크게 나타났다. 결론:본 연구에서 $Cerasys^{(R)}$, KaVo $Everest^{(R)}$, $LAVA^{TM}$시스템의 변연적합도는 차이가 없었고, 내면적합도는 KaVo $Everest^{(R)}$가 $LAVA^{TM}$ 보다 적었으나 세 시스템에서 공통적으로 절단부위 간격이 크게 나타났다. 세 시스템 모두 변연적합도 및 내면적합도가 임상적으로 허용범위 내에 있었다.

• 한국콘텐츠학회논문지
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• 제19권9호
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• pp.271-279
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• 2019

생활수준 향상과 의료기술의 발달로 평균수명이 꾸준하게 연장되고 있으며, 저출산이 굳어지고 기대수명이 길어지면서 유소년인구는 감소하는 반면, 고령 인구는 꾸준히 증가하고 있다. 시간과 생활에 여유가 있는 노인이 늘어나면서 건강관리에 대한 관심이 높아져 주로 걷기, 산책 등 큰 비용을 들이지 않고 운동장이나 공원에서 운동을 즐기는 노인이 점차 늘어나고 있다. 근린공원이나 약수터 등지에서 쉽게 볼 수 있는 야외운동기구는 노인의 일상생활에서 쉽게 접할 수 있는 건강증진 도구가 될 수 있으며, 야외운동기구 사용설명 사인은 노년층 사용자를 고려하여 가장 먼저 나타나는 노화의 현상인 시력 감퇴를 고려한 디자인을 해야 하며, 안전사고 예방을 위해서도 이의 적절한 디자인에 따른 정확한 정보전달은 매우 중요하다. 이에 따라 본 연구에서는 야외운동기구 사용설명 사인에 대한 노년층의 인지 여부와 인식 상의 문제점을 알아보기 위해 노년층을 대상으로 사용자 관찰 및 면접 조사를 실시하였다. 그 결과, 주의사항의 강조나 글씨 크기에 대한 문제점이 지적되었으며 글(문자) 위주의 설명보다 그림이나 사진 위주의 설명이 필요함을 알 수 있었다. 또한, 외래어 사용의 자제, 보편적인 단어 사용, 사인 내 운동 효과 포함에 대한 요구가 높은 것으로 나타났다. 본 연구에서는 사용자 관찰 및 면접 조사를 토대로 야외운동기구 사용설명 사인의 가이드라인을 제안하였다.

• 동아시아식생활학회지
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• 제9권3호
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• pp.325-335
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• 1999

The aim of the present study was to evaluate the relations among nutrient intake. self body image and satisfaction, and physical fitness of college students in Taegu. A total of 213 apparently healthy college students living in Taegu were selected for the study. The following anthropometric measurements were made on all participants : weight, height: waist and hip circumferences, and bioimpedence. Using weight and height, the body mass index (kg/$m^2$) was calculated. The 24-hour recall were obtained from subjects. Dietary habits and energy expenditure were examined through questionnaires. Nutrients intake were analyzed by computer aided nutritional analysis program. Variables of Physical fitness were consisted of body fat, muscular strength and endurance, agility. power, flexibility, cardiorespiratory function, physical efficiency index(PEI). Data were analyzed by computer using the SAS 6.12(Statistical Analysis System). The mean heights and weights of these students were similar to those reported for the 50th percentile in a national survey. Nutrient intake of the college students in Taegu was considerably lower than RDA. The male subjects' mean intake of two nutrients, vitamin B$_2$ and calcium, were less than 55% of the RDAs. the female subjects' mean intake of two nutrients, iron and calcium, were less than 55% of the RDAs. A most variables of physical fitness except sit and reach in male students showed a significant higher values than those of female students. There was a significant positive relationship between PEI and the intake of animal protein, fat, Ca. and B$_2$ in male students. Also there was a significant positive relationship between exercise duration of PWC 170 and protein, fat, iron, vitamin A, B$_2$, niacin, and energy intake in female students. The muscular strength showed the significant correlation with weight, height, and waist circumference in male and female students. The cardiorespiratory function and Physical efficiency index showed significantly negative correlation with tricep and subscapular skin thickness in the female students. There were significantly positive correlations between WHR and body efficiency index in male students, and significantly positive correlations between WHR and the cardiorespiratory function in female students. There was no significant level of correlation between the degree of satisfaction of body image and physical efficiency index. However. there was a significant positive correlation between waist circumference (and weight) and physical efficiency index in male and female students and almost all of the surveyed male and female college students wanted less waist circumference or weight even though they were in the criteria of standard waist circumference or weight. In conclusion, a beneficial effect of adequate nutrient intake on physical fitness was found, college students must increase their energy and nutrient intake if it is below than the RDA for improving their physical fitness.

• 대한가정학회지
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• 제40권11호
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• pp.1-9
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• 2002

Nowadays, the use of apparel CAD system is important to the mass production of ready to wear Especially, computer-based grading is the most important process to improve the fitness of clothes and to reduce the time needed to make patterns of several sizes. The purpose of this study was to suggest a standard sizing system for junior-high school girls' lower clothes and to suggest a grading method according to the sizing systems. The subjects were 402 junior-high school girls of 13 to 15 year's-old. The size intervals of waist girth and hip girth were 3㎝ and 4㎝ respectively. The sizing system, which had frequencies more than 4.5%, was classified 8 cases. For regular grading, two types of group were classified into 58-82/61-86/64-90/67-94 and 61-82/64-86/67-90/70-94. Among them, 61-86 and 64-86 size were adopted the basic size for the development of grading. According to the sizing system, hand-made patterns were manufactured. By measure of the each part of the slacks, new grading rule patterns were developed by each size. A new grading rule was different from the Moonwha grading rule. This result will contribute to clothing fitness of consumer and the amount of production.

• Journal of Communications and Networks
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• 제15권5호
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• pp.486-495
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• 2013

In this article, we suggest a two-dimensional genetic algorithm (GA) method that applies a cognitive radio (CR) decision engine which determines the optimal transmission parameters for multicarrier communication systems. Because a CR is capable of sensing the previous environmental communication information, CR decision engine plays the role of optimizing the individual transmission parameters. In order to obtain the allowable transmission power of multicarrier based CR system demands interference analysis a priori, for the sake of efficient optimization, a two-dimensionalGA structure is proposed in this paper which enhances the computational complexity. Combined with the fitness objective evaluation standard, we focus on two multi-objective optimization methods: The conventional GA applied with the multi-objective fitness approach and the non-dominated sorting GA with Pareto-optimal sorting fronts. After comparing the convergence performance of these algorithms, the transmission power of each subcarrier is proposed as non-interference emission with its optimal values in multicarrier based CR system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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• pp.137-140
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• 2003

This paper proposes a pursuing system utilizing the learning method where multiple cooperating agents emulate social behaviors of animals and insects and realize their group behaviors. Each agent contains sensors to perceive other agents in several directions and decides its behavior based on the information obtained by the sensors. In this paper, a neural network is used fir behavior decision controller. The input of the neural network is decided by the existence of other agents and the distance to the other agents. The output determines the directions in which the agent moves. The connection weight values of this neural network are encoded as genes, and the fitness individuals are determined using a genetic algorithm. Here, the fitness values imply how much group behaviors fit adequately to the goal and can express group behaviors. The validity of the system is verified through simulation.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제24권4호
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• pp.351-362
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• 2020

Adaptive behaviors are one of ubiquitous features in evolutionary dynamics of populations, and certain adaptive behaviors can be witnessed by individuals' movements which are generally affected by local environments. In this paper, by revisiting the previous work, we investigate the sensitivity of species coexistence in the system of cyclic competition where species movement can be affected by local environments. By measuring the extinction probability through Monte-Carlo simulations, we find the relativistic effect of weights of local fitness and exchange rate for adaptive movement on species biodiversity which promotes species coexistence as the relativistic effect is intensified. In addition, by means of basins of initial conditions, we also found that adaptive movement can also affect species biodiversity with respect to the choice of initial conditions. The strong adaptive movement can eventually lead the coexistence as a globally stable state in the spatially extended system regardless of mobility.

• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.99-107
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• 2022

Urban Air Mobility (UAM) such as a drone taxi is one of the future transportations that have recently been attracting attention. Along with the construction of an urban terminal, an accurate landing system for UAM is also essential. However, in urban environments, reliable Global Navigation Satellite Systems (GNSS) signals cannot be received due to obstacles such as high-rise buildings which causes multipath and non-line of sight signal. Thus, the positioning result in urban environments from the GNSS signal is unreliable. Consequently, we propose the Ultra-Wideband (UWB) network to assist the soft landing of UAM on a vertiport. Since the positioning performance of UWB network depends on the layout of UWB anchors, it is necessary to optimize the layout of UWB anchors. In this paper, we propose a two-steps genetic algorithm that consists of binary genetic algorithm involved multi objectives fitness function and integer genetic algorithm involved robust solution searching fitness function in order to optimize taking into account Fresnel hole effects.

• 한국의류산업학회지
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• 제6권5호
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• pp.634-640
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• 2004

Nowadays, the use of apparel CAD system is important to the mass production of ready to wear. Especially, computer-based grading is the most important process to improve the fitness of clothes and to reduce the time needed to make various size pattern. The purpose of this study was to suggest a standard sizing system for high school boys' pants and to suggest a grading method according to the sizing systems. The subjects were 217 high school boys of 16 to 18 year-old. The size intervals of waist girth and hip girth were 3 cm and 4 cm respectively. The sizing system, which had frequencies more than 4%, was classified 8 cases. Among them, 71-92 and 71-88 size were the most frequent size and were adopted the basic size for the two types of grading. According to the sizing system, hand-made patterns were manufactured. By measure of the each part of the slacks, 4 size's new grading-rule patterns were developed by each size. This result will contribute to clothing fitness of consumer and the amount of production.