• 에너지공학
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• 제23권2호
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• pp.102-113
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• 2014

본 논문은 한국 바이오에너지산업의 부가가치창출구조가 선순환을 나타내고 있는지를 바이오에너지기업 내 가치사슬을 통해 분석하고 있다. 연구 방법은 한국 바이오에너지기업을 대상으로 한 설문조사를 통해 연구개발-생산-이익률 등에 걸친 가치사슬 내 공정 간 인과관계에 대한 회귀분석을 활용하였다. 기업 내 가치사슬 분석의 결과, 한국 바이오에너지기업에서 기업의 연구개발 성과 증가는 기업의 생산량 증가에, 기업의 제품 생산비용 감소는 기업의 매출액 대비 경상이익률 증가에 긍정적인 영향을 미치고 있는 것으로 분석되었다. 그러나 정부의 연구개발 지원은 기업의 연구개발 투자 증가로 이어지지 못하고, 기업의 연구개발 성과 증가에 기여하지 못한 것으로 분석되었다. 또한 기업의 제품 생산량 증가는 기업의 제품 생산비용 감소에는 기여하지 못한 것으로 분석되었다. 한편, 경상이익률의 증가가 생산량의 증가와 기업의 연구개발투자 증가에는 기여하지 못하고 있어 가치사슬의 선순환구조가 취약한 것으로 분석되었다. 이러한 실증분석의 결과로부터 국내 바이오에너지기업의 공정 간 부가가치의 선순환 구조를 구축하기 위해서는 생산량의 증가와 규모의 경제효과를 달성을 위한 지원정책이 필요하다. 또한 경상이익률 증가가 생산량 증가와 연구개발투자 증가를 유발하는 정책을 추진할 필요가 있다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.272-273
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• 2014

Existing the free-form concrete segments (FCS) mold is produced by state of solid such as steel, wood, Styrofoam that can not be recycled. Using FCS mold result in delay on schedule and decrease of productivity because it consists of irregular curved variety and it requires more time than fixed mold. Thus, FCS mold should be developed which can reduce the costs and also it can be used as semipermanent. The aim of this study is to suggest of flexible mold production process for using the phase change materials(PCM). PCM is maintain that its solid state at low temperature but it changes phase to liquid state by heating. PCM is suitable material for flexible mold due to change of phase in relatively high temperature compare to other phase change materials such as water. Flexible mold is possible that reuse semi-permanently made by PCM. Thus, this study is proposed the process of flexible mold production for using the PCM. The study results will be used as the basic theory for studies on production and installation of FCS.

• 농촌계획
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• 제20권4호
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• pp.35-43
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• 2014

The purpose of this study is to analyze emergy flows of rice for evaluating the value of rice production and sustainability. Emergy analysis evaluates the sustainability of systems or processes considering all the inputs to make a product or a sevice. In this study, we analyzed the emergy flows and indices of rice productionand compared the regional emergy values using statisticcal analysis: input materials, hours per unit area(10a), and production costs. As the results, we found that the rates of external investment (EIR= 18.87) and environmental loading (ELR=21.7) are significantly high during the rice cultivation. However, emergy yield ratio(EYR) shows that rice is a valuable resource because EYR is 5.12 and environmental Sustainability IndexSI value is as low as 0.24 and it shows rice has low sustainability. This study also shows that Chungcheongnam-do has the highest SI value for rice production due to low environmental loading and abundant natural energy during rice cultivation. These results of rice emergy flows and sustainability assessments could provide a way of sustainable rice cultivation with decrease of environmental loading from fertilizer.

• 플랜트 저널
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• 제12권2호
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• pp.36-40
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• 2016

발전소 건설시 성능감소에 따른 페널티 책정은 발주처와 건설사의 계약서에 서명되며, 그 페널티 책정 방법론은 발주처와 건설사의 손익과 관련되어 있으므로 모두가 인정할 수 있도록 합리적이어야 한다. 따라서 페널티 책정 방법론은 매우 중요하다. 열병합발전은 전기와 열을 동시에 생산하는 시스템이므로, 열병합발전의 페널티 책정 방법론은 명확하지 않다. 열경제학은 다양한 에너지 비용을 산정하는 학문이나, 지금까지 페널티 책정 방법론에 대해 연구된 바 없다. 본 연구의 목적은 열경제학이 성능인수시험의 페널티 책정 방법론에 적용될 수 있음을 예시하는 것이다. CGAM 시스템의 해석결과 $10,000,000의 건설비용이 투입되었을 경우, $6,665,688이 전기생산 성능비용으로 책정되었고, $3,334,312이 배기가스 성능비용으로 책정되었다. 따라서 만약 전기생산 성능이 1% 감소하였다면 그 페널티는 $6,666 그리고 배기가스 에너지 성능이 1% 감소하였다면 그 페널티는 $3,334로 책정됨을 알 수 있다.

• 수산경영론집
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• 제36권1호
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• pp.139-153
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• 2005

Marine fish aquaculture has been introduced on the East sea since 1964. The production volume of the marine aquaculture has been increasing drastically since 1990 with the technological improvements and the introduction of new species. However, the increasing costs of feed, seedlings and medical supplies and the decreasing prices due to the increase in the imports and domestic production have decreased the profits in the aquaculture business. Futhermore, the damage from the natural disasters such as red tides and typhoons has accelerated the exit from the business. Even though managing abilities to overcome the business crisis caused by the above factors are required, business managers based on the small scale family businesses do not have enough managing abilities to deal with the difficulties in the business. On the other hand, advanced countries in the marine aquaculture such as Norway have reached the stage where the managing abilities of marine aquaculture are similar to those in the manufacturing industry. And the number of large scale aquaculture farms with developed technologies and advanced marketing strategies in those countries is increasing. Considering that the marine aquaculture in Japan under the similar fishery systems of Korea has developed the state-of-the-art management skills or lead to large scale management, it is difficult to expect the decrease in the production costs under the small scale family business in Korea and this will lead to the decreasing competitive advantage over the imported seafood. Therefore marine aquaculture in Korea needs to increase the economy of scale to acquire the competitive advantage. This study addresses the possibility of introducing the large scale aquaculture system in Korea by analysing the factors and process of leading to large scale businesses in the aquaculture in Japan.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.853-861
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• 2010

High substrate costs decrease the profitability of polyhydroxyalkanoates (PHAs) production, and thus low-cost carbon substrates coming from agricultural and industrial residuals are tested for the production of these biopolymers. Among them, crude glycerol, formed as a by-product during biodiesel production, seems to be the most promising source of carbon. The object of this study was to characterize the mixed population responsible for the conversion of crude glycerol into PHAs by cultivation-dependent and -independent methods. Enrichment of the microbial community was monitored by applying the Ribosomal Intergenic Spacer Analysis (RISA), and the identification of community members was based on 16S rRNA gene sequencing of cultivable species. Molecular analysis revealed that mixed populations consisted of microorganisms affiliated with four bacterial lineages: ${\alpha}$, ${\gamma}$-Proteobacteria, Actinobacteria, and Bacteroides. Among these, three Pseudomonas strains and Rhodobacter sp. possessed genes coding for polyhydroxyalkanoates synthase. Comparative analysis revealed that most of the microorganisms detected by direct molecular analysis were obtained by the traditional culturing method.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.36-42
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• 2024

The domestic gaming industry is a globally competitive field, but growth has recently slowed and competition in overseas markets is intensifying. Accordingly, it is important to analyze the investment status of the domestic gaming industry and study ways to revitalize it. The game industry is a labor-intensive, high-value-added industry that occupies an important position in the domestic content industry. However, the number of businesses and employees has been steadily decreasing for several years, and polarization within the industry is worsening. This is the effect of a decrease in investment in an industrial structure in which labor costs are the majority of production costs. Accordingly, we analyze the current status of the domestic gaming industry, and also analyze the investment status of the gaming industry and the investment structure of domestic venture capital to study the scale and required period of investment and investment projects needed to promote the industry. In this study, "the investment status of the domestic gaming industry and proposed revitalization measures. We study cooperation between the government, businesses, and academia to solve the problem of declining investment and slowing growth." We expect to strengthen competitiveness and continue to grow as we pursue revitalization plans.

• 한국시뮬레이션학회논문지
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• 제23권4호
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• pp.51-64
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• 2014

다품종 소량 생산을 따르는 중소기업들은 범용 장비와 이에 부착된 보조 장비를 활용하여 제품을 생산하고 있다. 이전에 많은 연구들은 이러한 중소기업의 환경에서 생산성 향상 관점의 설비 할당 연구를 진행해 왔다. 그러나 중소기업들은 제한된 예산 하에서 수요를 충족시켜야 하기 때문에 경제적 관점으로 설비와 작업을 할당하는 것이 매우 중요하다. 본 연구는 소모성 보조 장비의 잔존가치 개념을 이용하여 설비 할당 문제를 다루고자 한다. 소모성 보조 장비는 주 장비에 부착된 부품으로써 작업을 위해 꼭 필요한 부품이다. 그렇기 때문에 주 설비의 일정 작업시간 후에는 보조 장비의 구매가 이루어져야 한다. 본 연구에서는 PCB를 제조하는 S기업을 대상으로 잔존가치를 고려한 설비할당 방법과 S기업의 현행 설비할당 방법 (Cycle)이 장 단기 관점에서 보조 장비의 구매량과 구매비용에 어떤 영향을 미치는지 알아보기 위해 두 전략을 비교 실험하였다. 그 결과, 장 단기적 관점에서 모두 본 연구에서 제안하는 설비할당 방법이 현행방법보다 보조 장비의 구매수량 및 구매비용에 대해서 더 효율적인 결과를 보였다. 그러나 장기적으로 갈수록 현행방법과의 차이가 미미해짐을 알 수 있었다. 한편 유휴설비에 대한 대여 전략을 고려할 경우, 기업은 추가적인 이익 효과를 기대할 수 있음을 보였다.

• 한국결정성장학회지
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• 제18권4호
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• pp.137-139
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• 2008

Floating zone, neutron transmutation-doped and magnetic Czochralski silicon crystals are being widely used for fabrication power devices. To improve the quality of these devices and to decrease their production cost, it is necessary to use large-diameter wafers with high and uniform resistivity. Recent developments in the crystal growth technology of Czochralski silicon have enable to produce Czochralski silicon wafers with sufficient resistivity and with well-controlled, suitable concentration of oxygen. In addition, using Czoehralski silicon for substrate materials may offer economical benefits, First, Czoehralski silicon wafers might be cheaper than standard floating zone silicon wafers, Second, Czoehralski wafers are available up to diameter of 300 mm. Thus, very large area devices could be manufactured, which would entail significant saving in the costs, In this work, the conventional Czochralski silicon crystals were grown with higher oxygen concentrations using high pure polysilicon crystals. The silicon wafers were annealed by several steps in order to obtain saturated oxygen precipitation. In those wafers high resistivity over $5,000{\Omega}$ cm is kept even after thermal donor formation annealing.

• 상하수도학회지
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• 제28권2호
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• pp.161-170
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• 2014

It is essential to decrease energy consumption and excess sludge to economically operate sewage treatment plant. This becomes more important along with a ban on sea dumping and exhaustion of resource. Therefore, many researchers have been study on energy consumption reduction and strategies for minimization of excess sludge production from the activated sludge process. The aeration cost account for a high proportion of maintenance cost because sufficient air is necessary to keep nitrifying bacteria activity of which the oxygen affinity is inferior to that of heterotrophic bacteria. Also, additional costs are incurred to stabilize excess sludge and decrease the volume of sludge. There were anoxic, aerobic, membrane, deairation and concentration zone in this MBR process. Continuous aeration was provided to prevent membrane fouling in membrane zone and intermittent aeration was provided in aerobic zone through ammonia sensor. So, there was the minimum oxygen to remove $NH_4-N$ below limited quantity that could be eliminated in membrane zone. As the result of this control, energy consumption of aeration system declined by between 10.4 % and 19.1 %. Besides, we could maintain high MLSS concentration in concentration zone and this induced the microorganisms to be in starved condition. Consequentially, the amount of excess sludge decrease by about 15 %.