• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.43-45
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• 2004

This paper presents the optimal design of a brushless DC motor(BLDC) keeping the average torque and cogging torque of the initial model while minimizing the volume of magnet pole. Experimental design method and evolution strategy technique are performed for the shape optimization. The presented optimal designs show the both methods have the almost same result.

• Annual Conference of KIPS
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• 2012.11a
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• pp.335-338
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• 2012

유전 알고리즘 (Genetic Algorithm)은 기존의 알고리즘 개발방법을 통하여 해결하기 어려운 최적화 등의 문제를 해결하기 위한 자연계의 진화과정을 모방한 방법이다. 본 연구에서는 유전 알고리즘을 이용하여 KOSPI 200에서 거래되고 있는 증권의 매수/매도 종목을 추천하는 방법을 제시한다. 이를 위하여 기술적 분석 (Technical Analysis) 방법 중에서 Slow Stochastic 지표와 MACD 지표를 이용하여, 매일매일 두 지표가 나타내는 매매 신호를 기반으로 해당하는 각각의 종목에 대해 최근 가장 좋은 수익률을 나타내는 매수/매도 종목을 추천하는 방법을 구현한다.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.703-713
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• 2020

In many geological fields, including hydrogeology, it is of great importance to determine the heterogeneity of the subsurface media. This study briefly introduces the concept and theory of the method that can estimate the hydraulic properties of the media constituting the aquifer, which was recently introduced by Park (2020). After the introduction, the method was applied to the synthetic aquifer to demonstrate the practicality, from which various implications were drawn. The introduced technique uses a global optimization technique called the covariance matrix adaptation evolution strategy (CMA-ES). Conceptually, it is a methodology to characterize the aquifer heterogeneity by assimilating the groundwater level time-series data due to the imposed hydraulic stress. As a result of applying the developed technique to estimate the hydraulic conductivity of a hypothetical aquifer, it was confirmed that a total of 40000 unknown values were estimated in an affordable computational time. In addition, the results of the estimates showed a close numerical and structural similarity to the reference hydraulic conductivity field, confirming that the quality of the estimation by the proposed method is high. In this study, the developed method was applied to a limited case, but it is expected that it can be applied to a wider variety of cases through additional development of the method. The development technique has the potential to be applied not only to the field of hydrogeology, but also to various fields of geology and geophysics. Further development of the method is currently underway.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.6
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• pp.538-542
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• 2001

DNA computing has been applied to the problem of getting an optimal soluting since Adleman's experiment. DNA computing uses strings with various length and four-type bases that makes more useful for finding a global optimal solutions of the complex multi-modal problems This paper presents DNA coding method finding optimal solution of the multi-modal function and compares the efficiency of this method with the genetic algorithms(GA). GA searches efffectively an optimal solution via the artificial evolution of individual group of binary string and DNA coding method uses DNA molecules and four-type bases denoted by the A(Ademine) C(Gytosine);G(Guanine)and T(Thymine). The selection, crossover, mutation operators are applied to both DNA coding algorithm and genetic algorithms and the comparison has been performed. The results show that the DNA based algorithm performs better than GA.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.375-381
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• 2005

Usually genetic algorithms are used to design optimal system. However the performance of the algorithm is determined by the fitness function and the system environment. It is expected that a co-evolutionary algorithm, two populations are constantly interact and co-evolve, is one of the solution to overcome these problems. In this paper we propose three types of co-evolutionary algorithm to solve GA-Hard problem. The first model is a competitive co-evolutionary algorithm that solution and environment are competitively co-evolve. This model can prevent the solution from falling in local optima because the environment are also evolve according to the evolution of the solution. The second algorithm is schema co-evolutionary algorithm that has host population and parasite (schema) population. Schema population supply good schema to host population in this algorithm. The third is game model-based co-evolutionary algorithm that two populations are co-evolve through game. Each algorithm is applied to visual servoing, robot navigation, and multi-objective optimization problem to verify the effectiveness of the proposed algorithms.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.539-544
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• 2013

In this paper, we was designed three-dimensional face recognition algorithm using polynomial based RBFNNs and proposed method to calculate the recognition performance. In case of two-dimensional face recognition, the recognition performance is reduced by the external environment like facial pose and lighting. In order to compensate for these shortcomings, we perform face recognition by obtaining three-dimensional images. obtain face image using three-dimension scanner before the face recognition and obtain the front facial form using pose-compensation. And the depth value of the face is extracting using Point Signature method. The extracted data as high-dimensional data may cause problems in accompany the training and recognition. so use dimension reduction data using PCA algorithm. accompany parameter optimization using optimization algorithm for effective training. Each recognition performance confirm using PSO, DE, GA algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.6
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• pp.8-14
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• 2012

In this paper the core technologies of LTE/LTE-Adv systems which may enable the accommodation of huge mobile traffic today are introduced and investigated in order to provide some insights for future boradband mobile services provisioning. One of the key requirements for realization of broadband mobile services is to improve the efficiency of frequency usage and also stable performance of the LTE networks is indispensible to future use. In this sense, key technological issues are summarized hereafter and the technological breakthroughs required for the optimized operation of the networks are briefly discussed.

• 정보화사회
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• s.184
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• pp.28-39
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• 2007

IT산업은 항상 끊임없는 '혁신'을 통해서만 성장의 자양분을 얻는다. 기술적 또는 개념적 진보가 없다면 IT산업은 당연히 산업으로서의 존재가치가 없다. 그렇다면 2007년, 한국의 IT시장을 주도할 '10대 핵심 IT기술'들은 어떤 것들일까. 국내 통신 및 네트워크, 솔루션 업계가 가장 관심 있게 지켜보는 IT기술등 중 10개를 선별했다. 10대 IT기술에 포함된 것들 중에는 개념적으로는 10년전부터 출현해 알려져 있지만, 그동안 단순히 개념에 머물렀을 뿐 아직 상용화가 안 된 것들도 일부 포함돼 있다. 참신성보다는 실질적인 의미와 중요성에 무게들 둔 때문이다. 2007년에 주목할 만한 10대 IT기술로는 먼저 'IP 멀티미디어 서브시스템(IMS)이 꼽힌다. 유무선을 비롯한 다양한 네트워크를 자연스럽게 연결해주고 여러 서비스들의 다양한 조합이 가능해 고객맞춤형서비스를 가능하게 하는 '멀티미디어 멀티캐스트 컨트롤(MMC)도 10대 IT기술에 포함됐다. 이와 함께 100Mbps 초고속 인터넷 서비스를 가능하게 하는 ETTH (Ethernet To The Home), 차세대 보안이슈인 네트워크접근제어(NAC), 금융회사나 이동통신회사의 상품개발을 신속하게 지원하는 '프로덕트 팩토리', 하드웨어시스템의 최적화를 보장한 가상화 및 ILM, 컴퓨팅산업을 한 단계 이상 진화시킬 쿼드코어 CPU, 소프트웨어 시장의 새로운 패러다임인 SOA(서비스지향아키텍처), 본격적인 시장 확산이 기대되는 전자태그(RFID), IT거버넌스의 열기로 급부상하고 있는 ITAM(IT자산관리) 등도 올해 주목할 10대 IT기술 반열에 올랐다.

• Annual Conference of KIPS
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• 2001.10b
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• pp.1477-1480
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• 2001

기존 통신사업자가 급변하는 통신시장에 대응하기 위한 구체적 접근방법에 초점을 맞추어 통신기술의 변화와 이에 따른 기존망을 어떻게 개선하여야만 수익성에 차질을 빚지 않을 수 있느냐가 전재 조건이 된다. 먼저 통신기술의 변화에 따른 망의 진화방향을 음성의 패킷화 실현, 망 구조의 단순화 및 통합화를 통한 운용비용의 절감, 향후 신규서비스의 수용에 용이한 방향이 있어야 한다. 본 논문에서는 ATM을 중심으로 한 차세대 교환망에서 음성과 데이터가 동일 패킷망을 사용하므로서 망 대역폭을 효율적으로 활용하는 방법과 유효 대역 사용률을 향상하는 유연한 대역관리 방법에 대해 개괄적으로 논하였으며, 이를 바탕으로 대역폭 할당 프로토콜을 분석한 수 있는 모델을 제안하고, 주어진 음성 및 데이터 트래픽의 요구와 제약을 조건으로 시스템 파라미터를 최적화하기 위해 update interval 시간과 음성과 데이터 트래픽에 예약된 슬롯의 수를 사용하였다. 분석적인 모델은 성능에 관한 트래픽 유형들의 영향뿐만 아니라 혼합 트래픽 시스템의 동적 할당 방법과 대역관리 방법을 제공한다.

• Journal of Astronomy and Space Sciences
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• v.22 no.1
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• pp.13-20
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• 2005

Bound abrasive grinding is used for the initial fabrication phase of the precision aspheric mirrors for both space and ground based astronomical telescopes. We developed a new grinding optimization process that determines the input grinding variables for the target surface roughness, checks the grinding error magnitude in resulting surface roughnesses, and minimizes the required machining time. Using the machining data collected from the previous grinding runs and subsequently fed into the multivariable regression engine, the process has the evolving controllability that suggests the optimum set of grinding variables for each target surface roughness. The process model was then used for ten grinding experiments that resulted in the grinding accuracy of $=-0.906{\pm}3.38(\sigma)\;nm(Ra)$ for the target surface roughnesses of Zerodur substrate ranging from 96.1 nm (Ra) to 65.0 nm (Ra) The results imply that the quantitative process optimization technique developed in this study minimizes the machining time and offers the nanometric surface roughness controllability superior to the traditional, qualitative, craftsman based grinding process for the astronomical optical surfaces.