• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.104-109
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• 2001

The yield of infective juveniles of Heterorhabditis bacteriophora (Tf strain) in vitro monoxenic liquid culture was improved significantly as the amount of symbiont biomass, Photorhabdus sp. strain Tf, increased. To investigate the influence of abiotic factors on the growth and biomass production of Photorhabdus sp. strain Tf, triplicate flask cu1tmes were performed. The optinal temperature and medium pH for the growth of Photorhahdus sp. strain Tf were 30$^{\circ}$C and between pH 5.5-7.3, respectively. Aeration also improved greatly growth and yield of biomass of Photorhabdus sp. strain Tf. Photorhabdus sp. strain Tf in batch fermentation showed growth-associated pattem in terms of pigment production, and the pH of culture medium rose steadily until growth stopped dUling the fermentation. Both pigment production and culture pH rise would be useful parameters indicating a reliable growth of Photorhabdus sp. strain Tf.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.442-453
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• 2023

Tandem or multijunction solar cells (MJSCs) can convert sunlight into electricity with higher efficiency (η) than single junction solar cells (SJSCs) by dividing the solar irradiance over sub-cells having distinct bandgaps. The efficiencies of various common SJSC materials are close to the edge of their theoretical efficiency and hence there is a tremendous growing interest in utilizing the tandem/multijunction technique. Recently, III-V materials integration on a silicon substrate has been broadly investigated in the development of III-V on Si tandem solar cells. Numerous growth techniques such as heteroepitaxial growth, wafer bonding, and mechanical stacking are crucial for better understanding of high-quality III-V epitaxial layers on Si. As the choice of growth method and substrate selection can significantly impact the quality and performance of the resulting tandem cell and the terminal configuration exhibit a vital role in the overall proficiency. Parallel and Series-connected configurations have been studied, each with its advantage and disadvantages depending on the application and cell configuration. The optimization of both growth mechanisms and terminal configurations is necessary to further improve efficiency and lessen the cost of III-V on Si tandem solar cells. In this review article, we present an overview of the growth mechanisms and terminal configurations with the areas of research that are crucial for the commercialization of III-V on Si tandem solar cells.

• The Microorganisms and Industry
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• v.19 no.4
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• pp.14-26
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• 1993

Optimizing protein production in recombinant E. coli strains involves manipulation of genetic and environmental factors. In designing a production system, attention must be paid to gene expression efficiency, culture conditions and bioreactor configuration. Although not much emphasis was given to the physiology of host strains in this review, an understanding of the relationship between the physiology of host cell growth and the overproduction of a cloned gene protein is of primary importance to the improvement of the recombinant fermentation processes. Sometimes it is desirable to make use of gene fusion systems, e.g. protein A, polypeptide, gutathione-S-transferase, or pneumococcal murein hydrolase fusion, to facilitate protein purification.

• KSBB Journal
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• v.15 no.6
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• pp.584-588
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• 2000

The optimum conditions for the production of an antifungal antibiotic from Bacillus sp. YJ-63 were investigated. The oprimumized medium consisted of 1.5% soluble starch, 1% tryptone and 0.5% yeast extract, and temperature and initial medium pH for production were optimal at 35$^{\circ}C$ and pH 6.0, respectively. Production yield was significantly improved by shaking culture using 50 ml medium in 500 ml flasks. Under these conditions, the production of the antifungal antibiotic was growth-dependent, from 35hrs into cultivation to the stationary phase and endospore formation.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.127-131
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• 2011

Even if there are no causing factors such as car crash and road works, traffic congestion come from traffic growth on the road. In this case, estimation of traffic flow helps find the solution of traffic congestion problem. In this paper, we present a optimization model which used on traffic equilibrium problem and studied the problem of inverting shortest path sets for complex traffic system. And we also develop pivotal decomposition algorithm for reliability function of complex traffic system. Several examples are illustrated.

• The Pure and Applied Mathematics
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• v.3 no.1
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• pp.73-81
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• 1996

Multiple objective programming has been a popular research area since 1970. The pervasiveness of multiple objective in decision problems have led to explosive growth during the 1980's. Several approaches (interactive methods, feasible direction methods, criterion weight space methods, Lagrange multiplies methods, etc) have been developed for solving decision problems having multiple objectives. However there are still many mathematically challengings including multiple objective integer, nonlinear optimization problems which require further mathematically oriented research. (omitted)

• Korea journal of population studies
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• v.28 no.2
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• pp.1-32
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• 2005

The optimum population of a society or country can be defined as 'the population growth path that maximizes the welfare level of the society over the whole generations of both the present and the future, under the paths allowed by its endowments of production factors such as technology, capital and labor'. Thus, the optimum size or growth rate of population depends on: (i) the social welfare function, (ii) the production function, and (iii)demographic economic interrelationship which defines how the national income is disposed into consumption(birth and education of children included) and savings on the one hand and how the demographic and economic change induced thereby, in turn, affect production capacities on the other. The optimum population growth path can, then, be derived in the process of dynamic optimization of (i) under the constraints of (ii) and (iii), which will give us the optimum population growth rate defined as a function of parameters thereof. This paper estimates the optimum population growth rate of Korea by: specifying (i), (ii), and (iii) based on the recent development of economic theories, solving the dynamic optimization problem and inserting empirical estimates in Korea as the parametric values. The result shows that the optimum path of population growth in Korea is around TFR=1.81, which is affected most sensitively, in terms of the size of the partial elasticity around the optimum path, by the cost of children, share of capital income, consumption rate, time preference, population elasticity of utility function, etc. According to a survey implemented as a follow up study, there are quite a significant variations in the perceived cost of children, time preference rate, population elasticity of utility across different socio-economic classes in Korea, which implied that, compared to their counterparts, older generation and more highly educated classes prefer higher growth path for the population of Korea.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.2
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• pp.444-454
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• 2014

The range of optimization problem in aquaculture is very wide, resulting from the range of species, mode of operation. Quite a few studies focus marine net-cages, but studies on land based culture farm are few or no. This paper considers a allocation problem to meet production planning in land based aquaculture system. A water pool allocation model in land based aquaculture system was developed. The solution finds the value of decision variable to minimize yearly production costs that sums up the water pool usage cost and sorting cost. The model inputs were (1) the fish growth rate (2) critical standing corp (3) number of water pool (4) number of fish. The model outputs were (5) number of water pool in growing phase (6) cost of cultivation (6) optimal facility allocation(number of water pool for each growing phase). To solve the problem, an efficient heuristic algorithm based on a greedy manner is developed. Branch and bound and heuristic is evaluated through numerical examples.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.462-464
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• 2004

We studied the growth characteristics of carbon nanotubes which was grown from uniformly dispersed iron nanoparticles prepared from iron-acetate [Fe(II)$(CH_3COO)_2$]. The density of CNT was controlled from precursor concentrations. We also investigated the field emission properties of CNTs. We found that the optimization of CNT density is an important factor for field_emission properties.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.271-274
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• 2000

A study was carried out to select a nitrogen source and the optimize the C/N ratio for the maximum cell growth of Phaffia rhodozyma in fed-batch culture. The yeast extract was the best organic nitrogen source. In the batch culture experiments, the highest cell yield was obtained 0.575 g-cell/g-glucose from 10 g/L and 10 g/L yeast extract. In the fed-batch experiments, the maximum cell concentration was obtained 33.1 g/L from the C/N ratio of 2:1 while the astaxanthin concentration of cell was Increased by increasing the C/N ratio, of feed medium.