• 한국버섯학회지
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• 제12권3호
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• pp.145-153
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• 2014

Pleurotus has increased rapidly production and consumption because of highly nutritional value, natural healthy food and so on. The basic studies for Pleurotus need for development of mushroom industry. This study was to investigate the cultural characteristics among 15 strains of 6 species and to analyze their phylogenetic relationships. The cultural characteristics were investigated by mycelial growth activity at different media, temperature and pH. The optimum media for mycelial growth were YM and MCM in most species. The optimum temperature for mycelial growth were $25^{\circ}C$ and $30^{\circ}C$. The optimum pH for mycelial growth were widly range from pH 5.1 to 7.4. Through the RFLP (restriction fragment length polymorphism) of IGS (intergenic spacer) I region in ribosomal DNA, it was analyzed phylogeny of interspecies and intraspecies. Each species was discriminated well as isolates within each species formed clade to be distinguished other species. P. florida was highly similar to P. floridanus, and P. flabellatus was P. cornucopiae. P. fuscus var. ferulae was highly similar to P. eryngii but discriminated different species in analysis of RFLP of IGS I region and showed different characteristics in mycelial culture. RFLP of IGS I region was useful of studying phylogenetic relationships of species and population.

• 한국가시화정보학회지
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• 제17권3호
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• pp.24-31
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• 2019

Recently, an air-lift bio-reactor operated by micro bubbles has been utilized to product hydrogen fuel. To enhance the performance, characteristics of hydrodynamics inside the bio-reactor were analyzed using a numerical simulation for two-phase flow. An Eulerian model was employed for both of liquid and gas phases. The standard k-ε model was used for turbulence induced by micro bubbles. A Population Balance Model was employed to consider size distribution of bubbles. A hollow cylinder was introduced at the center of the reactor to reduce a dead area which disturbs circulation of CO bubbles. An appropriate diameter of the draft tube and hollow cylinder were optimized for better performance of the bio-reactor. The optimum model could be obtained when the cross-sectional area ratio of the hollow cylinder to the reactor, and the width ratio of the riser to the downcomer approached 0.4 and 3.5, respectively. Consequently, it is expected that the optimum model could enhance the performance of the bio-reactor with the homogeneous distribution and higher density of CO, and more effective mixing.

• 한국수산과학회지
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• 제24권1호
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• pp.1-8
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• 1991

문치가자미는 동경만의 소형저인강 어업의 중요한 대상종이나 최근 어획노력이 증가하는 경향이 있어 자원을 영속적으로 유효하게 이용하기 위하여 자원 평가를 하였다. 복수년급군에 대한 VPA 해석 결과, 1980년부터 1987년까지의 자원미수는 약 350만 마리에서 920만 마리였고, 1985년에 최대치를 보였다. 시험조업에 의한 추정량은 240만에서 870만 마리였고 최대치를 보인 해도 같았다. 양자의 차는 1987연에 약 2배였으나 그 밖의 해에는 0.8-l.5배의 차로 그다지 큰 차를 보이지 않았다. 양쪽 다 어획량과 단위노력당 어획양의 증감 경향이 유사했다 어획률은 대부분의 해에 $30-50\%$로 상당히 높은 수치를 보였다. COHORT 해석을 하여 어획계수를 추정하고, 수명으로 추정한 자연사망계수와 어획물과 성장에 의해 검토한 어획개시연령을 이용하여 등어획량곡선을 그려 자원현상을 평가하고 어획증대의 가능성을 검토한 바 가입당 어획량의 최대치가 암컷은 2배 숫컷은 1.3배 정도 증대 가능성을 보였다. 어획증대를 위해서는 강목을 크게 하여, 어획개시년령을 높이는 관리방안이 바람직하다.

• 상하수도학회지
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• 제12권1호
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• pp.70-80
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• 1998

Many algorithms to find a minimum cost design of water distribution network (WDN) have been developed during the last decades. Most of them have tried to optimize cost only while satisfying other constraining conditions. For this, a certain degree of simplification is required in their calculation process which inevitably limits the real application of the algorithms, especially, to large networks. In this paper, an optimum design method using the Genetic Algorithms (GA) is developed which is designed to increase the applicability, especially for the real world large WDN. The increased to applicability is due to the inherent characteristics of GA consisting of selection, reproduction, crossover and mutation. Just for illustration, the GA method is applied to find an optimal solution of the New York City water supply tunnel. For the calculation, the parameter of population size and generation number is fixed to 100 and the probability of crossover is 0.7, the probability of mutation is 0.01. The yielded optimal design is found to be superior to the least cost design obtained from the Linear Program method by $4.276 million.

• Advances in Computational Design
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• 제2권1호
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• pp.1-13
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• 2017

This paper presents a variant of the Harmony Search Algorithm (HS) and its application to discrete optimization. The main proposed modifications regarding original HS are related to stopping criterion and reinitialization of population, called Harmony Memory. In order to investigate the efficiency of the algorithm, it was applied for obtaining optimal sections of reinforced concrete columns subjected to uniaxial flexural compression. To minimize the cost of the section, the amount and diameters of the reinforcement bars and the dimensions of the columns cross sections were considered as design variables. The obtained results were compared to those generated by other optimization methods. Since, to the examples, Harmony Search reached the same results achieved by Simulated Annealing, some additional analysis are presented in order to compare these methods regarding success rate and number of iterations to reach the optimum.

• Journal of Plant Biology
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• 제15권2호
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• pp.7-19
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• 1972

The studies of density effect or the effect of population density on plant growth have been done on basis of dry matter production with Raphanus acanthiformis var. simoodaeguen, Brassica campestris var. Pekinensis f. namsounsokoombecheu, Oryza sativa f. kimmajae and O. sativa f. mangyeng grown in the various spacing. 1. In the early period of plant growth in dry weight was not different each other among varying densities, but as time advanced the plant grown vast space grew sufficiently compared with those of narrow one. 2. Iogarithmic relation between the growth of plant (W) and the density (P), log W-log P in the material plants, were approximated by two straight lines, one was horizontal line and another inclined: the former showed non-competition density and the latter competition density addition to these the point interlinking both lines were implied of the optimum density per unit land area at certain growth period. 3. The values of relatvie growth rate (RGR) and net assimilation rate (NAR) were decreased as increase in the density, while those of leaf area ratio (LAR) were rather increased in the same condition, with minor exception. From these results and relation between the productive structure and due to lack of the recieved light intensity owing to the mutal shading among the plants.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제3권1호
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• pp.115-125
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• 1999

Simple Genetic Algorithm(SGA) proposed by J. H. Holland is a population-based optimization method based on the principle of the Darwinian natural selection. The theoretical foundations of GA are the Schema Theorem and the Building Block Hypothesis. Although GA does well in many applications as an optimization method, still it does not guarantee the convergence to a global optimum in some problems. In designing intelligent systems, specially, since there is no deterministic solution, a heuristic trial-and error procedure is usually used to determine the systems' parameters. As an alternative scheme, therefore, there is a growing interest in a co-evolutionary system, where two populations constantly interact and co-evolve. In this paper we review the existing co-evolutionary algorithms and propose co-evolutionary schemes designing intelligent systems according to the relation between the system's components.

• 응용통계연구
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• 제11권1호
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• pp.141-150
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• 1998

본 논문에서는 매우 민감한 조사에서 모집단이 양적속성을 갖는 여러 개의 집락으로 구성되어 있을 때, 집락을 추출단위로 하는 단순집락추출법에 양적속성의 무관질문모형을 적용하였다. 그리고, 일정한 비용하에서 분산을 최소로 하는 집락의 크기와 표본집락의 수의 최적값을 구하여 최소분산의 형태를 도출하였다. 또한, 제안한 단순집략추출법에 의한 무관질문모형과 단순임의 추출법에 의한 무관질문모형과의 효율성을 비교해 보았다.

• 품질경영학회지
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• 제32권4호
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• pp.125-139
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• 2004

Generally, parallel redundancy is used to improve reliability in many systems. However, redundancy increases system cost, weight, volume, power, etc. Due to limited availability of these resources, the system designer has to maximize reliability subject to various constraints or minimize resources while satisfying the minimum requirement of system reliability. This paper presents GAs (Genetic Algorithms) to solve redundancy allocation in series-parallel systems. To apply the GAs to this problem, we propose a genetic representation, the method for initial population construction, evaluation and genetic operators. Especially, to improve the performance of GAs, we develop heuristic operators (heuristic crossover, heuristic mutation) using the reliability-resource information of the chromosome. Experiments are carried out to evaluate the performance of the proposed algorithm. The performance comparison between the proposed algorithm and a pervious method shows that our approach is more efficient.

• 응용통계연구
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• 제8권1호
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• pp.27-38
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• 1995

본 논문에서는 사회적으로나 개인적으로 매우 민감한 조사에서 모집단이 양적속성을 갖는 여러 개의 층으로 구성되어 있을 때, 층의 크기를 모르는 경우 층화표본을 위하여 이중추출법을 이용하는 층화이중추출법에 의한 양적속성의 무관질문모형을 제안하였다. 그리고, 층화이중추출에 있어서 각 층의 표본배분에 관해 비례배분, 최적배분으로 나누어 각 층의 크기를 알고 있는 경우에 층화추출법에 의한 양적속성의 무관 질문모형과 그 효율성을 비교하였다.