• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.221-222
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• 2003

Typically, closed production system units are subject to an accumulation of fine suspended solids and dissolved organics (Weeks et at., 1992). Foam fractionation process is believed to be most effective in marine application for solids removal. In present experiment, the performance of foam fractionator for removal of solids, protein, and other dissolved materials was evaluated at different foam overflow heights and air flow rates in a pilot-scale recirculating aquaculture system for culture of Korean rockfish. (omitted)

• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.79-88
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• 1999

In order top investigate the growth of water dropwort grown by sandculture irrigated with recirculated tilapia aquaculture water, these experiments were carried out. Fish(tilapia) production and biofiltration provided by sand cultured water dropwort(Oenanthe stolonifera DC.) were linked in a closed system of recirculation water. Water dropwort was irrigated with water drawn from the tilapia tank and drainage from sand beds was returned to the fish tank. The temperature, pH and EC of tilapia culture water were stable. The growth of water dropwort grown by sandculture with aquaculture water was normal. Microbial activity of the biofilterbed irrigated by tilapia rearing water was higher than that of biofilterbed irrigated by tapwater. The feasibility of an integrated, recirculatory system for concurrent production of water dropwort and fish with no additional fertilization application was demonstrated.

• The Journal of Fisheries Business Administration
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• v.13 no.1
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• pp.85-97
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• 1982

This study involves a blending of intensive and extensive shrimp culture techniques for a hypothetical shrimp farm which uses a combination of heated raceway nurseries and extensive grow-out ponds per year. The present value method of economic analysis is used to determine economic feasibility. The biological data in this reports were obtained from published or personal communications from leaders in the field of shrimp aquaculture. The proposed system showed economic feasibility using the present value method with discount rates of 10% and 12%. The most profitable scenario, the culture of three crops of Penaeus vannamei showed a 1.26 year payback period and 120% annual average rate of return. The breakeven price was ＄1.25/1b., which is ＄1.52 less than the market price of ＄2.77. Breakeven production was 724 1bs/acre, which is 8761bs. less than the assumed 1,600 1bs/acre. All other scenarios 1.2 and 3 crops for P. stylirostris and P. setiferus showed economic feasibility also.

• Journal of architectural history
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• v.15 no.4
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• pp.75-86
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• 2006

Korea is closed to China in the geographical position and is related to China as two countries have developed similar culture, art, and social systems. Architecture is a kind of culture and has advanced in the wooden architecture with a considerable change. The study investigated a phylogenetic relationship between two countries based on characteristics of architectural universality. With comparison and analysis on the common feature and difference of the beam and structure in the wooden architecture from the Koryo and Zhejiang Province(China), the systemicity of the wooden architecture was examined. The beam is a part of timber which is consist of the wooden structure frame and also a crucial subject to understand a development process of the wooden architecture.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.307-312
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• 2022

The commercialization of the fifth generation (5G) mobile systems has quested enabling technologies, such as intelligent reflecting surface (IRS) transmissions, towards the sixth generation (6G) networks. In this paper, we present a bit-error rate (BER) performance analysis on IRS transmissions in 5G non-orthogonal multiple access (NOMA) networks. First, we derive a closed-form expression for the BER of IRS-NOMA transmissions under Rician fading channels. Then, by Monte Carlo simulations, we validate the proposed approximate BER expression, and show numerically that the derived BER expression is in good agreement with Monte Carlo simulations. Furthermore, we also analyze the BER performance of IRS-NOMA networks under Rician fading channels with different numbers of reflecting elements, and demonstrate that the performances improve monotonically as the number of reflecting devices increases.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.307-314
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• 2021

Recently, positively asymmetric binary pulse amplitude modulation (2PAM) has been proposed to improve the bit error rate (BER) performance of the weak channel gain user, with a tolerable BER loss of the strong channel gain user, for non-orthogonal multiple access (NOMA). However, the BER loss of the stronger channel gain user is inevitable in such positively asymmetric 2PAM NOMA scheme. Thus, we propose the negatively asymmetric 2PAM NOMA scheme. First, we derive closed-form expressions for the BERs of the negatively asymmetric 2PAM NOMA. Then, simulations demonstrate that for the stronger channel gain user, the BER of the proposed negatively asymmetric 2PAM NOMA improves, compared to that of the conventional positively asymmetric 2PAM NOMA. Moreover, we also show that for the weaker channel gain user, the BER of the proposed negatively asymmetric 2PAM NOMA is comparable to that of the conventional positively asymmetric 2PAM NOMA, over the power allocation range less than about 10 %.

• The International Journal of Costume Culture
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• v.13 no.2
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• pp.101-103
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• 2010

Liberalization may be described as the opening up of the economy to the outside world by relaxing government trade and economic policy restrictions to allow imports. In Kenya, this took place in the early 1990s and it had negative and positive effects on businesses manufacturing and retailing clothing and textiles. This case study narrates what has happened over the last 20 years to businesses in Nairobi, Kenya dealing in clothing and textiles. Some of the original businesses have closed down and been replaced by new ones. More small scale Kenyan businesses have been started dealing in clothing imports from the East and West selling both new and second hand clothes. There has been increased employment in the small scale clothing and textiles sector in garment making and retailing. All in all, liberalization has forced large and medium scale textile manufacture to change strategy so that they target selling to the export market more than to the local market.

• Journal of Korean Library and Information Science Society
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• v.52 no.1
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• pp.1-26
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• 2021

In most countries, public libraries have played a role as a hub of knowledge and information, complex culture of local communities, and a third place for meeting and communication. And recent public libraries are focusing on enhancing their core competencies and expanding services using digital technologies to meet the era of digital transformation and the 4th industrial revolution. However, after the COVID-19 pandemic occurred, all public libraries are repeatedly closed, reopened, and partially closed, and all resources are devoted to providing non-contact, digital and online alternative services, and are expected to continue in the future. As a result, future public libraries are bound to face a trilemma in which digital expandability, complex cultural space, and importance as a place of knowledge and information service are conflicting. This study discoursed on the public library trilemma in the post-COVID-19 era and suggested ways to overcome it. The orientation of the future public library is the fusion and harmony of multiplicity and multipurpose, place and space, knowledge & information and complex culture, face-to-face service and remote service. The main body of a public library is not the finger (digital and non-contact), but the moon (knowledge information center).

• Korean Journal of Culture and Social Issue
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• v.9 no.1
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• pp.81-114
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• 2003

This study examines the basis and change of delinquent behavior among Korean adolescents. Theoretical framework was developed and qualitative analysis of delinquency behavior was examined. In order to understand the basis and change of juvenile delinquency, the influence of family environment, school environment and individual factors were investigated through cross-sectional and longitudinal studies. The results of the findings can be summarized into the following six main points: 1) two subcultures of adolescent functioning could be ascertained, 2) the decrease in social support and increase in moral disengagement were directly related to a rise in juvenile delinquency, 3) family disintegration contributed to juvenile delinquency, 4) peer influence help to raise juvenile delinquency, 5) schools were unable to give hope to those students who were not doing well in school and were ineffective in dealing with juvenile delinquents, and 6) the phenomenon of juvenile delinquency points to the importance of opening up the closed school system and closed society, allowing individual diversity and skills to be recognized.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.1-14
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• 1997

This experiment was conducted to find out the compositions of nutrient solution for closed system in substrate culture of cucumber. Cucumber(Cucumis sativus L. cv. Eunsung baekdadagi) plants were grown in the substrates supplied with the nutrient solutions whose strengths were 1/2, 1, and 3/2 of the original concentration developed by National Horticultural Research Station in Japan. By increasing the nutrient concentrations, plant height decreased but leaf length, leaf width, and leaf number showed little differences. A number of marketable fruit and marketable yield were the highest in the concentration of 1 strength. The nutrient compositions of solution developed for closed system in cucumber substrate culture were N 11.4, P 3.3, K 6.0, Ca 4.5, and Mg 3.5 me.$\ell$$^{-1}$ during the vegetative growth period and N 10.4, P 3.3, K 5.0, Ca 4.5, and Mg 3,5 me.$\ell$$^{-1}$ during the reproductive growth period. To examine the suitability of nutrient solution developed in the above experiment, cucumber plants were grown in the substrates supplied with different solutions and concentrations - Yamasaki's nutrient solution(Yamasaki) of 1 S, nutrient solution of Research Station for Greenhouse Vegetable and Floriculture on the Netherlands(PTG) of 1 S, nutrient solution developed in the above experiment(SCU) of 1/2, 1, and 3/2 S. EC and pH in root zone changed little in the all treatments during growing period. As cucumber plants grew, the concentrations of N, P, and K in root zone decreased but Ca concentration increased. Net $CO_2$ assimilation rate of cucumber leaves was high in SCU of 1 and 3/2 S, and Yamasaki of 1 S. Growth of cucumber plants was the lowest in SCU of 1/2 S.