• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.140-140
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• 2000

Traditional genetic algorithms, though robust, are generally not the most successful optimization algorithm on any particular domain. Hybridizing a genetic algorithm with other algorithms can produce better performance than both the genetic algorithm and the other algorithms. In this paper, we use random process and simulated annealing instead of mutation operator in order to get well tuned fuzzy rules. The key of this approach is to adjust both the width and the center of membership functions so that the tuned rule-based fuzzy controller can generate the desired performance. The effectiveness of the proposed algorithm is verified by computer simulation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.303-310
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• 2002

After many casualties with conventional bulk carriers in recent years, double hull bulk carrier was proposed to enhance the structural safety of side shell and transverse bulkhead. In this paper, two alternative structural designs of double hull bulk carrier were executed based on the Lloyd's rule, and the results were examined in comparison with the existing single hull bulk carrier in the viewpoints of the increase of weight and construction cost. The relative construction concept was used to certify the economical validity of double hull bulk carrier.

• Journal of Welding and Joining
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• v.29 no.4
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• pp.61-66
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• 2011

The purpose of this study is to develop improved boom structures with reliable fatigue strength of weldment and lower production cost. For that purpose, multi-body dynamic analysis was performed to evaluate forces acting on arm & boom cylinders and joints of boom structure during operation of an excavator for three working postures, then stress analysis was made to investigate stress distribution around diaphragms at the bottom plate of boom structures which was known to be susceptible to fatigue failures of welded joints, and finally boom structures with optimum arrangement of diaphragms was proposed. This work mainly consists of the following two parts: part 1 focuses on multi-body dynamic analysis of excavators during operation and part 2 includes evaluations of fatigue strength of welded joints for modified boom structures.

• Management Science and Financial Engineering
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• v.9 no.1
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• pp.11-27
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• 2003

In this study, we propose a mathematical model based on the graph theory for the wavelength assignment problem arising in the design of SDH (Synchronous Digital Hierarchy) over WDM (Wavelength Division Multiplexing) ring networks. We propose a branch- and -price algorithm to solve the suggested models effectively within reasonable time in realistic SDH over WDM ring networks. By exploiting the structure of ring networks, we developed a polynomial time algorithm for efficient column generation and a branching rule that conserves the structure of column generation. In a computer simulation study, the suggested approach can find the optimal solutions within reasonable time and show better performance than the existing heuristics.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.831-834
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• 2017

본 논문은 Medical Expert 시스템을 효율적으로 운영하기 위해서 Drools 와 JavaFX기반으로 한 사용자 인터페이스를 설계 및 구현을 한다. 본 Medical Expert System을 구축하기 위하여 Drools의 내부의 구조인 BlackBoard 아키텍처 스타일을 이해하고 JavaFX을 이용하여 Medical Expert 시스템을 설계 및 구현 하였다. 이 시스템의 진행 프로세스는, 설문지 및 환자 진단으로 인해 환자에 대한 증상정보들을 파악 후 미리 정해 둔 rule들에 적용시켜서 그 결과 값을 도출한다. 또한 본 시스템은 JavaFX에 scene builder 이용하여 인터페이스를 구성함으로써 기존의 Swing의 단점을 보완하고 장점을 부각시키도록 구현하였다.

• Journal of Ocean Engineering and Technology
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• v.10 no.2
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• pp.13-19
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• 1996

For fatigue analsis of offshore structures, existing methods have been reviewed and a computer code has been developed on PC. As methods to estimate the probabillity distribution of the fatigue stress, three methods(the deterministic method, the stochastic method, and the simplified method) are used in this code, to choose the appropriate method according to the situations. This code estimates damage ratios, fatigue lives, and probabilities of fatigue failure considering scatterness of SN-data, based on linear damage rule and SN-curves. Also, allowable stress for the design extreme wave can calculated by the simplified method.

• Industrial Engineering and Management Systems
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• v.9 no.1
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• pp.54-59
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• 2010

A two-plan sampling system is proposed for a failure-censored life testing when the lifetime follows a Weibull distribution with known shape parameter. The proposed sampling system is based on a switching rule, for switching between the tightened and the normal inspection levels when lots are submitted for inspection in the order of production or in some other systematic way. The design parameters of the proposed sampling system are determined by the two-point approach considering the producer's risks and the consumer's at the specified acceptable reliability level and the lot tolerance reliability level, respectively. It has been observed that the proposed system requires only a single failure for the observation.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2946-2948
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• 2000

In this paper, we proposed the Fuzzy Polynomial Neural Networks(FPNN) model with fuzzy activation node. The proposed FPNN structure is generated from the mutual combination of PNN(Polynomial Neural Networks) structure and fuzzy inference system. The premise of fuzzy inference rules defines by triangular and gaussian type membership function. The fuzzy inference method uses simplified and regression polynomial inference method which is based on the consequence of fuzzy rule expressed with a polynomial such as linear, quadratic and modified quadratic equation are used. The structure of FPNN is not fixed like in conventional Neural Networks and can be generated. The design procedure to obtain an optimal model structure utilizing FPNN algorithm is shown in each stage. Gas furnace time series data used to evaluate the performance of our proposed model.

• 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.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.3
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• pp.306-310
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• 2004

This paper suggests a reverse segmentation algorithm using affix information and some preference pattern information of Korean compound nouns. The structure of Korean compound nouns is mostly derived from Chinese characters, and it includes some preference patterns utilized as a segmentation rule in this paper. To evaluate the accuracy of the proposed algorithm, an experiment was performed with 36,061 compound nouns. The experiment resulted in getting 99.3% of correct segmentation and showed excellent satisfactory results from the comparative experimentation with other algorithms. Especially, most of the four-syllable or five-syllable compound nouns were successfully segmented without fail.