• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.11
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• pp.533-539
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• 2005

According to NERC definition, Available Transfer Capability (ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity. To calculate Available Transfer Capability, accurate and defensible Total Transfer Capability, Capacity Benefit Margin and Transmission Reliability Margin should be calculated in advance. This paper proposes a method to quantify time varying Available Transfer Capability based on probabilistic approach. The uncertainties of power system and market are considered as complex random variables. Total Transfer Capability is determined by optimization technique such as SQP(Sequential Quadratic Programming). Transmission Reliability Margin with the desired probabilistic margin is calculated based on Probabilistic Load Flow analysis, and Capacity Benefit Margin is evaluated using LOLE of the system. Suggested Available Transfer Capability quantification method is verified using IEEE RTS with 72 bus. The proposed method shows efficiency and flexibility for the quantification of Available Transfer Capability.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.2
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• pp.43-49
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• 2000

It is a complex process to analyze power system voltage stability problems with all of the dynamics of a system, because a large power network system sophisticatedly consists of generators, lines, loads and so forth. So we considered the dynamics of loads so as to analyze voltage stability method- by carrying out an analysis of steady state voltage stability and dynamic voltage stability simultaneously. To perform a steady state voltage stability program in advance makes it possible to cut down on laborious calculations so that an analysis of dynamic voltage stability becomes concise. The validity and efficiency of the method presented in this paper were verified by applying the IEEE 14 bus system.

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.58-68
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• 2004

This paper presents an optimal routing algorithm (ORA) for maximizing voltage stability as well as for minimizing power loss in radial power systems. In the proposed ORA, a novel voltage stability index (VSI) for real-time assessment is newly introduced based on the conventional critical transmission path framework. In addition, the suggested algorithm can automatically detect the critical transmission paths resulting in voltage collapse when additional real or reactive loads are added. To implement an effective ORA, we have developed an improved branch exchange (IBE) method based on a loss calculation index and tie-branch power flow equations, which are suggested for real-time applications. The proposed algorithm has been tested with IEEE test systems as well as a large-scale power system in Korea to demonstrate its effectiveness and efficiency.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2744-2746
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• 2000

일반화된 회귀 신경망을 이용하여 반도체 공정 최적화를 위한 플라즈마를 모델링한다. 플라즈마는 Box-W린son 실험계획표에 의해 특성화되었으며, 여기에서 변화시킨 인자로는 소스전력, 압력, 척지지대의 위치, 그리고 염소의 유량이다. 총 24회의 실험이 수행이 되었으며, 플라즈마 변수는 Langmuir Probe를 이용하여 측정하였다. 측정된 주요 플라즈마 변수로는 전자밀도, 전자온도, 그리고 플라즈마 전위이다. 폭변수를 점진적으로 증가시켜 회귀신경망을 최적화하였으며. 최적화된 모델은 통계적인 반응표면모델과 비교하였다. 비교 결과, 회귀신경망은 반응표면모델에 상응하는 예측능력을 보이고 있음을 알 수 있었다.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.654-656
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• 1998

This paper presents an optimal identification method of nonlinear and complex system that is based on fuzzy-neural network(FNN). The FNN used simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rule. And we use a HCM Algorithm to find initial parameters of membership function. And then to obtain optimal parameters, we use the genetic algorithm. Genetic algorithm is a random search algorithm which can find the global optimum without converging to local optimum. The parameters such as membership functions, learning rates and momentum coefficients are easily adjusted using the genetic algorithms. Also, the performance index with weighted value is introduced to achieve a meaningful balance between approximation and generalization abilities of the model. To evaluate the performance of the FNN, we use the time series data for 9as furnace and the sewage treatment process.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.3
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• pp.322-328
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• 2008

Recently, the rapid progress of Internet and Network affects engineering design environment as well as Business fields to utilize Web technologies to enhance it's competitively in the world. In product development, experts and organizations actually taking part in the design process are often geographically dispersed. Furthermore, different divisions and businesses often have heterogeneous CAD/CAE systems and methods for expressing product data, and addressing this heterogeneity creates additional costs and causes longer development periods. To ensure successful collaboration in the design process, it is therefore imperative that distributed CAD, CAE, and other related systems be managed in an organic and integrated manner from the initial stages of product development. Therefore, this study suggests Web-based MDO(Multidisciplinary Design Optimization) framework to support interfacing and the collective use of design and analysis tools.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.3
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• pp.33-40
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• 1992

In this paper, We designed a 2-stage amplifier for transponder of satellite with dual GaAs FETs NE13783, and performed the worst-case analysis for circuit qualification in the space environment. The bandwidth of amplifier was chosen 11.7-12.2 GHz which is the down link frequency band for domestic Ku-band satellite communication, and the alumina substrate with 25 mil of thickness. The design and optimization of amplifier was achieved by the commercial CAD program TOUCHSTONE and the measurement was performed through the automatic network analyzer.

• Annual Conference on Human and Language Technology
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• 2015.10a
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• pp.231-233
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• 2015

본 논문에서는 심층 신경망 기반의 내장형 음성 인식 시스템에서 음성 인식 속도를 개선하기 위한 최적화 방법에 대해 논한다. 심층 신경망 기반의 음성 인식은 기존의 Gaussian Mixture Model (GMM) 기반에 비해 좋은 인식 성능을 보이지만 높은 연산량으로 인해 리소스가 제약된 내장형 단말기에 적용하기에는 어려움이 따른다. 따라서, 본 연구에서는 심층 신경망의 계산량 문제를 해결하고자 ARM 코어에 내장된 병렬 명령어를 사용한 최적화 기법과 특이값 분해를 통해 심층 신경망 매트릭스 연산량 감소 방안에 대해 제안한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.4
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• pp.103-110
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• 2007

The facility location in designing a supply chain network is an important decision problem that gives form, structure, and shape to the entire supply chain system. Location problems involve determining the location, number, and size of the facilities to be used. The optimization of these location decisions requires careful attention to the inherent trade-offs among service time, inventory costs, facility cost, transportation costs. This paper presents a strategy that provides the best locations of distribution centers using GIS(Geographical Information System) assuming the limitation of delivery time. To get the best strategy of the location of distribution centers, we use the new loss functions as a penalty when the delivery time is violated

• International Journal of Naval Architecture and Ocean Engineering
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• v.1 no.2
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• pp.70-77
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• 2009

Today, many middle-sized shipbuilding companies in Korea are experiencing strong competition from shipbuilding companies in other nations. This competition is particularly affecting small- and middle-sized shipyards, rather than the major shipyards that have their own support systems and development capabilities. The acquisition of techniques that would enable maximization of production efficiency and minimization of the gap between planning and execution would increase the competitiveness of small- and middle-sized Korean shipyards. In this paper, research on a simulation-based support system for ship production management, which can be applied to the shipbuilding processes of middle-sized shipbuilding companies, is presented. The simulation research includes layout optimization, load balancing, work stage operation planning, block logistics, and integrated material management. Each item is integrated into a network system with a value chain that includes all shipbuilding processes.