• 한국측량학회지
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• 제38권5호
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• pp.415-423
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• 2020

GNSS (Global Navigation Satellite System) is mostly used for high-precise surveys due to its accuracy and efficiency. But this technique does not always fulfill the demanding accuracy in harsh operational environments such as urban canyon and forest. One of the remedies for overcoming this barrier is to compose a heterogeneous surveying network by adopting terrestrial measurements (i.e., distances and angles). Hence, this study dealt with the adjustment of heterogeneous surveying networks consisted of GNSS baseline vectors, distances, horizontal and vertical angles with a view to enhancing their accuracy and so as to derive an appropriate scheme of the measurement combination. Reviewing some technical issues of the network adjustments, the simulation, and experimental studies have been carried out, showing that the inclusion of the terrestrial measurements in the GNSS standalone overall increased the accuracy of the adjusted coordinates. Especially, if the distances, the horizontal angles, or both of them were simultaneously adjusted with GNSS baselines, the accuracy of the GNSS horizontal component was improved. Comparing the inclusion of the horizontal angles with those of the distances, the former has been more influential on accuracy than the latter even though the same number of measurements were employed in the network. On the other hand, results of the GNSS network adjustment together with the vertical angles demonstrated the enhancement of the vertical accuracy. As conclusion, this paper proposes a simultaneous adjustment of GNSS baselines and the terrestrial measurements for an effective scheme that overcomes the limitation of GNSS control surveys.

• 한국산학기술학회논문지
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• 제12권2호
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• pp.847-851
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• 2011

태양광 발전 시스템은 친환경성을 바탕으로 설치용량이 증가하고 있으며 효율 개선을 위한 연구가 활발하다. 고 효율 시스템 설계를 위해서는 태양전지 패널의 출력특성을 정확히 파악하는 것이 중요하다. 태양전지 패널은 단일 다이오드 모델로 물리적 특성을 표현할 수 있으나, 정확한 파라미터를 얻는 것은 여러 단계의 측정과 수치해석 등의 복잡한 과정을 거쳐야 한다. 본 논문에서는 패널 제조사의 데이터 시트에 제공되는 태양전지 패널의 I-V 특성곡선을 기반으로 패널의 단일 다이오드 모델의 특성 파라미터를 추출하는 방법을 제시하였다. 제시한 방법의 검증을 위하여, Simulink의 Solar Cell 블록에 추출한 파라미터를 입력하여 출력을 측정하고, 데이터 시트와 오차를 계산하였다.

• 한국해양공학회지
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• 제27권5호
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• pp.1-9
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• 2013

Because the environmental regulations for ships are getting tighter, green ships employing eco-friendly technology have recently received a large amount of attention. Among them, various studies for electric propulsion ships have been carried out, particularly in the United States, European Union, and Japan. On the other hand, research related to electric propulsion ships in Korea is in a very nascent stage. In this paper, an estimation process based on the rough requirements of ship-owners for the operating performance of electric propulsion ships is proposed. In addition, the estimation process is applied to a small fishing boat for verification of the process. These results are expected to be used as design guidelines in the early stage of the design process for electric propulsion ships.

• 대한토목학회논문집
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• 제39권4호
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• pp.551-559
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• 2019

2000년대 이후 정부의 친환경 정책 및 경전철 도입 실패사례 등으로 인해 기존 경전철 대비 건설 및 운영비용이 저렴한 트램을 도입하기 위해 많은 지자체에서 노력하고 있다. 하지만 트램 도입 이후 운영단계에서 이용자의 편의성, 안전성, 쾌적성 등을 유지하고 증대할 수 있는 서비스 평가체계는 부재한 상황이며, 현재 철도사업자 또는 버스운송사업자에게 시행되고 있는 "대중교통운영자에 대한 경영 및 서비스평가"의 평가항목 및 평가방법을 적용하기에는 트램 특성이 반영되어 있지 않아 많은 문제가 발생할 것으로 판단된다. 본 연구는 트램 운영모델에 따른 운영 서비스 평가 기준을 개발하기 위해 민자도로와 여객자동차, 도시철도 및 철도사업자, 항공 부분에 시행 중인 운영서비스 평가 관련 사례를 검토하고, 운영서비스 평가항목 및 평가항목별 가중치, 평가기준을 제시하였다. 본 연구를 통해 향후 도입될 트램의 운영단계에서 운영서비스 확보 및 개선에 도움을 줄 수 있을 것으로 기대한다.

• 농업과학연구
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• 제47권4호
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• pp.1011-1020
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• 2020

Efficient management systems of facilities make it possible to manage environmental conditions properly, such as the temperature, humidity and light source required for the best growth of the crops, as well as for the mass production of fruit and vegetables with high quality every year through an advanced and protected cultivation system. Powdery mildew is a type of chronic disease that is difficult to control during the production of Korean melons under a protected cultivation system, the use of which is increasing in production areas in Korea. Two Bacillus strains isolated from soil samples showed antagonistic activities against several pathogens, specifically Botrytis cinerea, Colletotrichum gloeosporioides, and Fusarium oxysporum f.sp. melonis; they were identified as Bacillus velezensis M2 and B. amyloliquefaciens M3 in a molecular biological test of the nucleotide sequences of gyrase subunit A (gyrA). The treatment was given three times at intervals of five days with 400-fold diluted cultures of B. velezensis M2 and B. amyloliquefaciens M3. This led to the inhibition of the incidence of powdery mildew disease in Korean melon leaves, which resulted in effective control efficiency against the incidence of powdery mildew disease with control values of 87% and 65%, respectively. Cultures of antagonistic microbes tested in this study can be used to increase the efficiency as part of an environmentally friendly management scheme to prevent powdery mildew disease during the protected cultivation of crops, including Korean melons.

• 한국해양공학회지
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• 제35권1호
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• pp.50-58
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• 2021

The demand for eco-friendly energy is expected to increase due to the recently strengthened environmental regulations. In particular, the flow inside the pipe used in a cargo handling system (CHS) or fuel gas supply system (FGSS) of hydrogen transport ships and hydrogen-powered ships exhibits a very complex pattern of multiphase-thermal flow, including the boiling phenomenon and high accuracy analysis is required concerning safety. In this study, a feasibility study applying the boiling model was conducted to analyze the multiphase-thermal flow in the pipe considering the phase change. Two types of boiling models were employed and compared to implement the subcooled boiling phenomenon in nucleate boiling numerically. One was the "Rohsenow boiling model", which is the most commonly used one among the VOF (Volume-of-Fluid) boiling models under the Eulerian-Eulerian framework. The other was the "wall boiling model", which is suitable for nucleate boiling among the Eulerian multiphase models. Moreover, a comparative study was conducted by combining the nucleate site density and bubble departure diameter model that could influence the accuracy of the wall boiling model. A comparison of the Rohsenow boiling and the wall boiling models showed that the wall boiling model relatively well represented the process of bubble formation and development, even though more computation time was consumed. Among the combination of models used in the wall boiling model, the simulation results were affected significantly by the bubble departure diameter model, which had a very close relationship with the grid size. The present results are expected to provide useful information for identifying the characteristics of various parameters of the boiling model used in CFD simulations of multiphase-thermalflow, including phase change and selecting the appropriate parameters.

• 한국의류산업학회지
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• 제24권2호
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• pp.206-216
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• 2022

This study sought to examine the sustainability criteria found in the global sourcing practices of global fashion retailers. Sustainable supply chain management, with a particular focus on the sustainability criteria of global sourcing, was analyzed. This qualitative study was based on a focus group interview and corporate social responsibility (CSR) annual reports. Eight master categories, 18 middle categories, and 37 bottom categories were extracted. The key categories and their middle categories were as follows: (1) Social compliance (working conditions, employment, safety); (2) Environment concerns (environmental pollution management, eco-friendly production, supply chain environment); (3) Energy efficiency (energy saving program, store environment); (4) Consumer protection (restricted substances management, consumer product safety improvement); (5) Management system (code of conduct, triangle audit system); (6) Community social activities (local community service, voluntary activities, charitable activities); (7) External stakeholder engagement (media & non-governmental organization management, maintenance of relationship with local authority); (8) Brand protection (respect for companies' intellectual property). The findings of this study offer academically significant insights into the sustainability criteria that can be encountered by companies under diverse global sourcing scenarios, revealing that global sourcing by fashion retailers is not merely a means of reducing costs, but a way of generating new jobs and making a social contribution to developing countries. The study's findings also have practical significance, offering guidelines for general CSR activities in the global sourcing process.

• 한국포장학회지
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• 제28권1호
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• pp.67-73
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• 2022

The food cold chain refers to a technology and distribution supply chain applied to maintain a constant temperature suitable for the product from production (harvest) to delivery to consumers. In particular, in Korea, the insulation material used in the food cold chain is mostly EPS (Expanded Polystyrene), which is used as a transport container for various food cold chains. However, according to the government's eco-friendly policy, companies charge environmental contributions to the use of EPS, but due to its low price and convenience of handling, it is still used as a container for delivering food. In this study, in order to measure the domestic delivery environment of general refrigerated foods, changes in impact, temperature, and humidity during transport of the EPS packaging system containing foods and ice pack refrigerants were measured. As a result, there were 2?3 sections in which a high impact force of 40 G or more was generated during transport. This can cause damage to the product and EPS container. The difference in temperature and humidity changes by parcel transport routes is more than 30%, so it is necessary to present accurate standards for the domestic cold chain distribution environment. As a result of microbial experiments. the transportation period had a dominant effect on the increase in total viable count and E. coli count.

• 수산해양기술연구
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• 제59권1호
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• pp.19-27
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• 2023

The interest in greenhouse gases (GHG) emitted from all industries is emerging as a very important issue worldwide. This is affecting not only the global warming, but also the environmentally friendly competitiveness of the industry. The fisheries sector is increasingly interested in greenhouse gas emissions also due to the Paris Climate Agreement in 2015. Korean industry and government are also making a number of effort to reduce greenhouse gas emissions so far, but the effort to reduce GHG in the fishery sector is insufficient compared to other fields. Especially, the investigation on the GHG emissions from Korean fisheries did not carry out extensively. The studies on GHG emissions from Korean fishery are most likely dealt with the GHG emissions by fishery classification so far. However, the forthcoming research related to GHG emissions from fisheries is needed to evaluate the GHG emission level by species to prepare the adoption of Environmental labels and declarations (ISO 14020). The purpose of this research is to investigate which degree of GHG emitted to produce the species (swimming crab and snow crab) from various fisheries. Here, we calculated the GHG emission to produce the species from the fisheries using the life cycle assessment (LCA) method. The system boundary and input parameters for each process level are defined for LCA analysis. The fuel use coefficients of the fisheries for the species are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for producing the unit weight species and annual production are calculated by fishery classification. The results will be helpful to establish the carbon footprint of seafood in Korea.

• 무역상무연구
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• 제31권
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• pp.27-56
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• 2006

Today's financial institutions usually take environmental issues seriously into consideration as they could not evade lender liability in an increasing number of cases. On the international scene, a brand-new concept of the "Equator Principles" in the New Millenium has driven more and more international banks to adopt these Principles in project financing. Sustainable development has been a key word in understanding new trends of the governments, financial institutions, corporations and civic groups in the 21st century. The Equator Principles are a set of voluntary environmental and social guidelines for sustainable finance. These Principles commit bank officers to avoid financial support to projects that fail to meet these guidelines. The Principles were conceived in 2002 on an initiative of the International Finance Corporation(IFC), and launched in June 2003. Since then, dozens of major banks, accounting for up to 80 percent of project loan market, have adopted the Principles. Accordingly, the Principles have become the de facto standard for all banks and investors on how to deal with potential social and environmental issues of projects to be financed. Compliance with the Equator Principles facilitates for endorsing banks to participate in the syndicated loan and help them to manage the risks associated with large-scale projects. The Equator Principles call for financial institutions to provide loans to projects under the following circumstances: - The risk of the project is categorized in accordance with internal guidelines based upon the environmental and social screening criteria of the IFC. - For Category A and B projects, borrowers or sponsors are required to conduct a Social and Environmental Assessment, the preparation of which must meet certain requirements and satisfactorily address key social and environmental issues. - The Social and Environmental Assessment report should address baseline social and environmental conditions, requirements under host country laws and regulations, sustainable development, and, as appropriate, IFC's Environmental, Health and Safety Guidelines, etc. - Based on the Social and Environmental Assessment, Equator banks then make agreements with borrowers on how they mitigate, monitor and manage the risks through a Social and Environmental Management System. Compliance with the plan is included in the covenant clause of loan agreements. If the borrower doesn't comply with the agreed terms, the bank will take corrective actions. The Equator Principles are not a mere declaration of cautious banks but a full commitment of lenders. A violation of the Principles in the process of project financing, which led to an unexpected damage to the affected community, would not give rise to any specific legal remedies other than ordinary lawsuits. So it is more effective for banks to ensure consistent implementation of the Principles and to have them take responsible measures to solve social and environmental issues. Public interests have recently mounted up with respect to environmental issues on the occasion of the Supreme Court's decision (2006Du330) on the fiercely debated reclamation project at Saemangeum. The majority Justices said that the expected environmental damages like probable pollution of water and soil were not believed so serious and that the Administration should continue to implement the project seeking ways to make it more environment friendly. In this case, though the Category A Saemangeum Project was carried out by a government agency, the Supreme Court behaved itself as a signal giver to approve or stop the environment-related project like an Equator bank in project financing. At present, there is no Equator bank in Korea in contrast to three big banks in Japan. Also Korean contractors, which are aggressively bidding for Category A-type projects in South East Asia and Mideast, might find themselves in a disadvantageous position because they are generally ignorant of the environmental assessment associated with project financing. In this regard, Korean banks and overseas project contractors should care for the revised Equator Principles and the latest developments in project financing more seriously. It's because its scope has expanded to the capital cost of US$10 million or more across all industry sectors regardless of developing countries or not. It should be noted that, for a Korean bank, being an Equator bank is more or less burdensome in a short-term period, but it must be conducive to minimizing risks and building up good reputation in the long run.