• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.777-782
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• 2002

Reciprocal effects among local breeds and additive and heterosis effects were estimated for total milk production per lactation (TLP), lactation length (LL) and daily milk yield (DMY). Procedures for an optimum crossbreeding system were examined by comparing various crossbred combinations. Three data sets were chosen from the total records collected from 1962 to 1997. Data set I with a total of 5,938 records composed of 9 breed groups for reciprocal crosses, data set II with a total of 6,064 records composed of 5 breed groups for additive and heterosis effects and data set III with a total of 10,319 records composed of 42 breed groups for optimum crossbreeding system were analyzed. The least squares ANOVA was used. The reciprocal crosses between Red Sindhi and the Bangladeshi Local showed significant difference. When the Red Sindhi was used as cow, the cross was superior to the opposite in terms of the three performance traits. The results showed that additive breed effects on both TLP and DMY were positive and highly significant between Bos indicus and Bos taurus, whereas the individual heterosis effects were not significant. In general, any local breeds were improved two to three times by crossing with the Friesian once or twice. However, the effect was reduced when the grading up with the Friesian was repeated more than twice. On the other hand, when the local breed was crossed with the other breeds such as Holstein and Jersey, the improvement of TLP was less. Crossing the F1 cows with the Friesian bull gave further improvement. Almost the same trends were found also for LL and DMY. The local breeds and their crosses are raised mainly for draft animals, then it is recommended that the crossbreds between the local cows and Friesian are used for dairy purposes and more than 75% Friesian blood is used for beef.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.44-46
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• 2008

This paper Proposes a new couple particle swarm optimization (CPSO) for multimodal functions. In this method, main particles are generated uniformly using Faure-sequences, and move accordingly to cognition only model. If any main particle detects the movement direction which has local optimum, this particle would create a new particle beside itself and make a couple. After that, all couples move accordingly to conventional particle swarm optimization (PSO) model. If these couples tend toward the same local optimum, only the best couple would be kept and the others would be eliminated. We had applied this method to some analytic multimodal functions and successfully locate all local optima.

• 산업경영시스템학회지
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• 제20권42호
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• pp.39-47
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• 1997

There are four parameters (i.e. overall density, local density, grouping, layout complexity) to consider in designing screen of a visual display terminal. Among these, only the optimum level of overall density is known to be about 25~30% by some studies. Therefore, the present experiment is conducted to define the optimum levels of the other parameters to achieve the user's best performance in visual search task. The results are as follows; (1) The function related to the levels of local density and user's search times is shown to be U -shaped. When the level of local density is about 40%, the search time is shorter than those of any other levels. (2) In the experiment of grouping, user's performance is best when the number of group is 5, and the size of group does not exceed visual angle $5^{\circ}$ (0,088rad). (3) The user performance is improved as the layout becomes less complex.

• 제어로봇시스템학회논문지
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• 제6권12호
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• pp.1061-1069
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• 2000

In this paper, a new genetic algorithm is proposed for solving multimodal function optimization problems that are not easily solved by conventional genetic algorithm(GA)s. This algorithm finds one of local optima first and another optima at the next iteration. By repeating this process, we can locate all the local solutions instead of one local solution as in conventional GAs. To avoid converging to the same optimum again, we devise a new genetic operator, called a Mendel operator which simulates the Mendels genetic law. The proposed algorithm remembers the optima obtained so far, compels individuals to move away from them, and finds a new optimum.

• 산업공학
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• 제8권1호
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• pp.23-30
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• 1995

Optimization in the engineering design is to select the best of many possible design alternatives in a complex design space. One major problem of local minimization algorithm is that they often result in local optima. In this paper, a hybrid method was developed by coupling the genetic algorithm and a traditional direct search method. The proposed method first finds a region for possible global optimum using the genetic algorithm and then searchs for a global optimum using the direct search method. To evaluate the performance of the hybrid method, it was applied to three test problems and a problem of designing corrugate bulkhead of a ship.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 춘계학술발표회 논문집
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• pp.120-127
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• 1998

It is very difficult to execute the vibration analysis of a huge strucutre, which takes up much time and expense. In this paper we intend to make the equivalent system of a local vibration system of a huge structure with a view to improving the dynamic characteristics and reducing time and expense. First of all, upper deck structure model is maded. And we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the upper deck structure model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. To make the equivalent system, we give boundary condition to sub-structure that want to be modified and execute the Sensitivity Analysis Method and the Optimum Structural Modification Method. And we execute the structural modification of the equivalent system.. The following can be found from this study. 1. The analytical results are generally coincident with each other. 2. The equivalent system of the superstructure model can be easily obtained using the sensitivity analysis metho and the optimum structural modification method. 3. The structural modification using the equivalent system can be obtained good results above 90% of object value.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1186-1191
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• 2003

The 40% of wall criterion, which is generally used for the plugging of steam generator tubes, may be applied only to a single crack. In the previous study, a total of 9 failure models were introduced to estimate the local failure of the ligament between cracks and the optimum coalescence model of multiple collinear cracks was determined among these models. It is, however, known that parallel axial cracks are more frequently detected during an in-service inspection than collinear axial cracks. The objective of this study is to determine the plastic collapse model which can be applied to the steam generator tube containing two parallel axial through-wall cracks. Nine previously proposed local failure models were selected as the candidates. Subsequently interaction effects between two adjacent cracks were evaluated to screen them. Plastic collapse tests for the plate with two parallel through-wall cracks and finite element analyses were performed for the determination of the optimum plastic collapse model. By comparing the test results with the prediction results obtained from the candidate models, a plastic zone contact model was selected as an optimum model.

• Nuclear Engineering and Technology
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• 제36권4호
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• pp.316-326
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• 2004

The $40\%$ of wall criterion, which is generally used for the plugging of steam generator tubes, is applied only to a single crack. In a previous study, a total number of 9 failure models were proposed to estimate the local failure of the ligament between cracks, and the optimum coalescence model of multiple collinear cracks was determined among these models. It is, however known that parallel axial cracks are more frequently detected than collinear axial cracks during an in-service inspection. The objective of this study is to determine the plastic collapse model that can be applied to steam generator tubes containing two parallel axial through-wall cracks. Three previously proposed local failure models were selected as the candidates. Subsequently, the interaction effects between two adjacent cracks were evaluated to screen them. Plastic collapse tests for the plate with two parallel through-wall cracks and finite element analyses were performed to determine the optimum plastic collapse model. By comparing the test results with the prediction results obtained from the candidate models, a COD base model was selected as an optimum model.

• 대한토목학회논문집
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• 제14권6호
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• pp.1375-1383
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• 1994

관수로시스템 문제는 수리학적 및 시스템운영 제약조건아래서 시스템의 전체비용을 최소비용으로 구하는 것이다. 관수로시스템 문제는 수많은 국지해(local minimum)을 갖는 비볼록(nonconvex) 이므로 종래의 최적화 기법은 임의의 국지해만을 구할 수 있다. 따라서 본 연구에서는 좀더 나은 국지해를 구하기 위해 외부탐사 및 내부최적화 단계 즉 2 단계 분해기법을 제안하였다. 외부탐사 단계에서는 관로들의 최적유량을 찾기 위해 여러 국지해 사이를 이동하면서 좀더 나은 국지해를 찾는 방법인 추계학적탐사방법(stochastic probing method)을 이용 하였고 내부최적화 단계(local minimizer)에서는 외부탐사 단계에서 구한 국지해를 증진시킨다. 이 제안한 방법은 신설 관수로시스템 설계와 기존 관수로시스템의 확장에 적용할 수 있으며, 제안한 방법의 효율성을 검증하기 위해 어느 관수로시스템을 표본으로 채택하여 제안한 방법을 적용한 결과 먼저 발표된 연구자들의 결과보다 적은 비용으로 설계할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.110.2-110
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• 2002

Evolutionary Algorithm is the general method that can search the optimum value for the various problems. Evolutionary method consists of random selection, crossover, mutation, etc. Since the next generation is selected based on the fitness values, the crossover between chromosomes does not have any restrictions. Not only normal marriage but also consanguineous marriage will take place. In human world, consanguineous marriage was reported to cause various genetic defects, such as poor immunity about new diseases and new environment disaster, These problems translate into searching for the local optimum, not the global optimum. So, a new evolutionary algorithm is needed that prevents traps to...