• 대한전기학회논문지:전력기술부문A
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• 제49권6호
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• pp.305-311
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• 2000

This paper presents a hybrid algorithm for solving optimal power flow(OPF) in order to enhance a systems capability to cope with outages, which is based on combined application of evolutionary computation and local search method. The efficient algorithm combining main advantages of two methods is as follows : Firstly, evolutionary computation is used to perform global exploitation among a population. This gives a good initial point of conventional method. Then, local methods are used to perform local exploitation. The hybrid approach often outperforms either method operating alone and reduces the total computation time. The objective function of the security constrained OPF is the minimization of generation fuel costs and real power losses. The resulting optimal operating point has to be feasible after outages such as any single line outage(respect of voltage magnitude, reactive power generation and power flow limits). In OPF considering security, the outages are selected by contingency ranking method(contingency screening model). The OPF considering security, the outages are selected by contingency ranking method(contingency screening model). The method proposed is applied to IEEE 30 buses system to show its effectiveness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권3호
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• pp.815-834
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• 2012

Recently, along with the innovative development of wireless communication techniques and mobile devices, mobile P2P services in mobile wireless networks have gained a lot of attention. In this paper, we propose a resource discovery scheme with data dissemination over mobile P2P networks. In the proposed scheme, each peer manages a local information table, a resource index table, and a routing table in a local database to enhance the accuracy and cost of resource discovery. The local information table stores the status of a mobile peer, and the resource index table stores the resource information of the neighbor peers via the ranking function. The routing table is used to communicate with the neighbor peers. We use a timestamp message to determine whether or not the resource index table will be changed before the resource information is exchanged. Our ranking function considers the interest and mobility of the mobile peer and prioritizes the resource information transmitted from the neighbor peers. It is shown via various experiments that the proposed scheme outperforms the existing scheme.

• 수산경영론집
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• 제39권3호
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• pp.25-47
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• 2008

The Fishing Communities (so-called Uchongae) in Korea was legally established in 1962. It has been gradually expanded by quantity, and we have total 1,969 communities in 2006. The major establishment purpose of Uchongae was put 2 functions. The first function is to make up the double industry structure in coastal region, and second function is to make economical condition for Uchongae. Nevertheless the Fishing Communities System in Korea was not successfully developed after first beginning. The Income gap have become heavily between fishing area and non - fishing area, including agricultural area. The income gap has been due to rapid industrialization and urbanization in Korea. And the income gap even have become heavily among Uchongaes. In this paper, It have been researched the degree of Income inequality among Uchongaes in Korea during 1986-2006. The income inequality degree was analyzed by Gini coefficient and Mean Log Deviation (MLD) using Lorenz Curve. According to analysis result, the Gini coefficient of Uchongaes in Korea has been about 2-times high from 0.0847 to 0.1770 during 20 years. And the MLD has been 5.4 times from 0.0125 to 0.0679 during same periods. This means to more wide the general Income Inequality among the Uchongaes in Korea. Especially, It means to more wide the gap of high ranking Uchongaes and low ranking Uchongaes that MLD index multiplier has been more high.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권5호
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• pp.295-304
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• 2003

In this paper, we proposed a hardware-oriented Genetic Algorithm Processor(GAP) based on subpopulation architecture for high-performance convergence and reducing computation time. The proposed architecture was applied to enhancing population diversity for correspondence to premature convergence. In addition, the crossover operator selection and linear ranking subpop selection were newly employed for efficient exploration. As stochastic search space selection through linear ranking and suitable genetic operator selection with respect to the convergence state of each subpopulation was used, the elapsed time of searching optimal solution was shortened. In the experiments, the computation speed was increased by over $10\%$ compared to survival-based GA and Modified-tournament GA. Especially, increased by over $20\%$ in the multi-modal function. The proposed Subpop GA processor was implemented on FPGA device APEX EP20K600EBC652-3 of AGENT 2000 design kit.

• 대한교통학회지
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• 제27권2호
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• pp.23-34
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• 2009

본 연구는 전통적인 중방향 설계시간 교통량의 문제점을 개선하기 위해 양방향 교통량이 아닌 중방향 교통량에 따른 링크통행시간의 확률분포개념을 도입하여 확률적인 중방향 설계시간 교통량(PDDHV) 산정 모형에 대한 실험적 해석을 수행하였다. PDDHV산정에 대한 실험적 결과를 토대로 적정 설계순위를 2차로/4차로에 대해 16개의 확률분포형을 대상으로 최우도법을 이용하여 매개변수를 추정하였으며, 적합도 검정은 Kolmogorov-Smirnov 검정을 적용하였다. 적정 설계순위 확률분포형은 2차로도로는 Beta General분포, 4차로도로는 Weibull분포가 가장 적합한 것으로 나타났다. 차로별 적정 확률분포형에 대해 누적분포함수의 역함수를 이용하여 설계서비스수준 D에 따른 적정 설계순위를 산정한 결과, 2차로는 190 순위, 4차로는 164 순위로 도출되었다. 또한, PDDHV 산정에서 새롭게 제시한 계수에 대한 적정값은 2차로 도로 경우 PK계수는 0.119(0.100${\sim}$0.139), PD계수는 0.568(0.545${\sim}$0.590)이며, 4차로도로 경우 PK계수는 0.106(0.097${\sim}$0.114), PD계수는 0.571(0.544${\sim}$0.598)로 도출되었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.298-303
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• 2003

The eccentric rotor system has various problems by vibration of unbalance mass. Specially, it is difficult to analyze vibration problem for the drum washing machine due to correlation of transmission paths. We analyze the mechanical structure by multidimensional spectral density to identify the maximum vibration magnitude at the frequency domain. It estimates the coherence function of the signals to pass the transmission paths. In case of the drum washing machine, because the transmission paths are correlated partially it needs to determinate the priority ranking. And the correlated parts are eliminated using conditioned spectral density function. Finally the shielding effect method confirms the reasonability of the modeling.

• The Journal of Korean Physical Therapy
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• 제25권6호
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• pp.374-378
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• 2013

Purpose: Human body have biological rhythmic pattern in a day, which is affected by internal and external environmental factors. We investigated whether respiratory function was fluctuated according to the influence of time-of-day (around at 9 am, 1 pm, and 6 pm) in health subjects, using pulmonary function test (PFT). Methods: Eighteen healthy volunteers (8 men, mean ages; $22.4{\pm}1.6$, mean heights; $166.61{\pm}9.60$, mean weight; $59.3{\pm}10.3$) were recruited. Pulmonary function test (PFT) was measured at three time points in day, around 9 am, 1 pm, and 6 pm in calm research room with condition of under 55dB noise level, using a spirometer (Vmax 229, SensorMecis, USA). Forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FVC/FEV1, and peak expiratory flow (PEF) were acquired. Results: In comparison of raw value of PFT among three time points, subjects showed generally better respiratory function at 9 am, than at other points, although no significance was found. In comparison of distribution of ranking for respiratory function in each individual, only PEF showed significant difference. In general, distributional ratio of subjects who showed best performance of respiratory function in a day was high. Conclusion: These findings showed that circadian rhythm by diurnal pattern was not detected on respiratory function throughout all day. But, best performance on respiratory function was observed mostly in the morning, although statistical significance did not exist.

• 산업경영시스템학회지
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• 제39권2호
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• pp.138-149
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• 2016

Quality function deployment (QFD) is a widely adopted customer-oriented product development methodology by translating customer requirements (CRs) into technical attributes (TAs), and subsequently into parts characteristics, process plans, and manufacturing operations. A main activity in QFD planning process is the determination of the target levels of TAs of a product so as to achieve a high level of customer satisfaction using the data or information included in the houses of quality (HoQ). Gathering the information or data for a HoQ may involve various inputs in the form of linguistic data which are inherently vague, or human perception, judgement and evaluation for the information and data. This research focuses on how to deal with this kind of impreciseness in QFD optimization. In this paper, it is assumed as more realistic situation that the values of TAs are taken as discrete, which means each TA has a few alternatives, as well as the customer satisfaction level acquired by each alternative of TAs and related cost are determined based on subjective or imprecise information and/or data. To handle these imprecise information and/or data, an approach using some basic definitions of fuzzy sets and the signed distance method for ranking fuzzy numbers is proposed. An example of a washing machine under two-segment market is provided for illustrating the proposed approach, and in this example, the difference between the optimal solution from the fuzzy model and that from the crisp model is compared as well as the advantage of using the fuzzy model is drawn.

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권3호
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• pp.236-243
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• 2009

특허, 뉴스, 블로그와 같이 시간 정보가 있는 문서들로부터의 자동적인 트렌드 분석(trend analysis)은 토픽탐지 및 추적 기술(TDT: Topic Detection and Tracking)과 더불어 중요한 연구 분야로 대두되고 있다. 과거 연구들은 대부분 트렌드과 관련된 단어의 출현 빈도 정보를 이용하여 주어진 개념의 중요도를 측정하고 이 개념의 시간에 따른 트렌드 라인을 보여주는 것에 초점을 맞췄다. 신출 트렌드 (emerging trend)를 탐지하기 위해서는 주어진 개념의 출현 빈도수 변화와 같은 간단한 방법이나 학습 데이타와 비교하여 차이를 탐지하여 제시하는 방법이 사용되었다. 그러나 여러 트렌드 중에서 특징적인 트렌드를 찾아서 사용자에게 제공하기 위해서는 트렌드 순위 결정 함수가 필요하다. 본 논문은 트렌드의 다양한 측면을 정량화하기 위하여 출현 빈도로 구성된 트렌드 곡선으로부터 네 가지 속성 (변동성, 지속성, 안정성, 누적량) 을 정의하고 이를 활용한 트렌드 순위 결정 방법을 제안한다. 일련의 실험을 통하여 각 속성의 유용성을 검증하고 속성들의 조합이 순위 결정에 어떤 영향을 미치는지 분석하였다. 실험결과로부터 네 가지 속성을 모두 조합할 경우 특징적인 트렌드 탐지에 더욱 기여하는 것을 알 수 있다.

• Journal of the Korean Statistical Society
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• 제13권1호
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• pp.25-31
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• 1984

A technique which has been used for the evaluation of certain kinds of multiple integrals, viz., the technique of imcomplete gamma function operators, is employed and extended to the case where the parameters and arguments are non-equal and non-integer for the probability integral of the inverted Dirichlet distribution. Several types of recurrence formulas have been developed for the tail probabilities and a subset selection procedure in ranking variances is discussed as an application.