• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2089-2091
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• 2000

Pulsed power systems consist of a capacitor bank, an isolated high-voltage charging power-supply, high-current bus-work for charging and discharging and a control system. In such pulsed power systems, the operating-lifetime of the capacitors is closely dependent on the voltage reversal. Hence, most capacitor-discharging systems includes crowbar circuits. The crowbar circuit prevents the capacitor recharging with reverse voltage. Usually it consists of crowbar resistors and high pulse-current diode-stacks connected in series. The requirements for the diode-stacks are fast-recovery time and high-voltage and large-current ratings, which results in the high cost of the pulsed-power system. This paper presents a protection scheme of a charging and discharging system of a 500kJ capacitor bank using a low-cost crowbar circuit and safety-fuses.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.343-344
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• 2005

• 한국농공학회지
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• 제8권2호
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• pp.1110-1118
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• 1966

• 콘크리트학회지
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• 제15권3호
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• pp.80-86
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• 2003

• Asian Journal of Business Environment
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• 제11권3호
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• pp.33-43
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• 2021

Purpose: The purpose of the paper is to assess the greening of investment flows as well as the orientation of financial sources of effective environmental protection. Both India and Vietnam are considered to be two Asian countries that are radically affected by global climate change. Governments of the two countries have implimented numerous measures against environmental pollution through the banking and finance sector. Developing green banking operations in India and Vietnam is a new direction in the socio-economic development strategy coupled with effective environmental protection. Research design, data and methodology: The data was mainly based on Asia Development Bank Institution (ADBI) and Bank of India (BOI) from 2015 - 2018. This paper focused on comparing and evaluating the development of green banks between the two countries. Result: The banks' contribution to green growth and green economy is shown in two basic aspects: (i) the connection between organizations, and individuals, and management process for investment projects, including environmental risks; and (ii) the operation of banks has a direct impact on the environment, through the application of technology to pay documents and apply e-banking. Conclusion: Paper reflects, compares and evaluates green banking operations in India and Vietnam to provide new directions aiming to develop financial and economic system along with effective and efficient step toward climate change control. India's green banking operations, after a specific assessment, will be lessons for the Government of Vietnam during the process of socio-economic development and environmental protection.

• 무역상무연구
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• 제44권
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• pp.85-107
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• 2009

L/C allows the exporter to have a bank's payment undertaking against shipping documents required by L/C. This means that the exporter can take export proceeds from a L/C issuing bank regardless of importer's payments and therefore the L/C better mitigate importer's credit risk compared to remittance and collections. Recently the use of L/C has been on down trend in line with increasing use of T/T, causing a big change of payment system. This tells that the payment method change in Korea is positive as the change also happens same in developed countries. This however gives more buyer's credit risk to exporters and therefore a systematic solution to this negative effect is required. In Korea, export credit insurance has been widely used to cover the buyer's credit risk. But the export credit insurance is limited because of lack of government's financial support and strict evaluation of buyer and exporter. Now Korea is ranked 10the largest trading country and therefore the exporters shall find another source for credit risk protection elsewhere. And as such this paper suggest International Factoring as a tool for the credit risk protection. The International Factoring gives advantages to the exporter in terms of credit protection and advances by purchasing account receivables on a without recourse basis.

• 대한지역사회영양학회지
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• 제11권5호
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• pp.618-628
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• 2006

The purpose of this study was to examine the donators' characteristics and donative foods of both government-dominant and non-governmental food bank program, to understand the problems and benefits of food bank program, and to find the solutions to activate food bank program. The questionnaires were distributed to 120 food bank operators and 3 donators were selected from each food bank for the survey from April 2002 to May 2002. 118 sheets (32.8%) from government-dominant food bank and 53 sheets (20.1%) from non-governmental food bank were collected. The main results of this study were as follows: The largest donators to either government-dominant or non-governmental food bank programs were bakery and confectionery companies 31.4% and 45.3% respectively. The majority of donated foods were 'goods in stock' (55.6%) and frequency of donation were largely on a daily basis (27.1% for government-dominant and 22.6% for non-governmental). Some of the donators who had more donative food did not donate, and the reasons were closeness to expiration date of food (67.3%), lack of legal protection in the event of food poisoning (54.5%), and poor public image of food related accidents (52.3%).

• Ecology and Resilient Infrastructure
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• 제6권4호
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• pp.217-226
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• 2019

본 연구에서는 하천의 하안 경사와 친수시설 유무에 따라 적절한 하안 보호 공법을 유형화하였으며, 특히 기존의 호안 공법으로 하안침식 방지 대책 적용이 적절하지 않은 유형에 대해 적용 가능한 신개념 Eco-hybrid 롤링매트 공법을 제시하였다. Eco-hybrid 롤링매트 공법은 지반과 사면의 교란없이 하천 환경과 생태 조건의 변화를 최소화하는 시공이 가능하고, 하안침식이 발생할 경우 즉각적인으로 호안이나 제방 사면을 보호할 수 있는 경제적이고 효율적인 공법이다. 개발된 Eco-hybrid 롤링매트 공법은 실규모 하천 실험을 통해 공법의 구조 및 시스템, 기능과 효과를 검증하였다. 현장에서 발생할 수 있는 여러 변형 및 부패 테스트를 포함한 실규모 하천 실험 검증을 수행하였으며, 저유속과 고유속 조건에서 롤링매트의 작동과 하안침식 방지 효과를 확인하였다. 하안침식 방지 효과는 유사 농도 분석을 통해 정량적으로 검증하였으며, 실험에 활용한 롤링매트를 기준으로 규격화하여 Eco-hybrid 롤링매트 공법의 제품의 시방 (안)을 제시하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권12호
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• pp.584-590
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• 2002

Crowbar system is usually applied to a pulsed power system in which a capacitor bank is discharged into a load. This provides a free wheeling path for the load current and prevents the capacitor from recharging due to a reverse voltage. Usually diodes have been used as a crowbar switch, but it is not a practical system because the cost of the diodes goes up enormously with increasing the system voltage and current. This paper presents a novel protection scheme of a charging and discharging system of a 300 kJ capacitor bank using a low-cost crowbar system which consists of a crowbar switch and resistors. Triggered vacuum switch(TVS) was used for a crowbar switch, and Rogowski coil was used to determine a trigger time of TVS. When this crowbar system is applied to our pulsed power system which consists of capacitor bank($123muF$), inductor() for forming a pulse, load resistor$(100 m\Omega)$, and a closing switch, instantaneous reversal voltage of capacitor bank could be limited less than 1.8 ㎸ until capacitor bank was charred to 17 ㎸.

• 한국습지학회지
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• 제10권3호
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• pp.87-97
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• 2008

본 연구는 현재 대부분의 자연형 하천에 적용되는 프리캐스트 호안블록 대신 현장 타설식 일체형 블록시스템을 개발하고 수리특성분석을 위하여 수리모형 실험을 실시하여 수위와 유속의 변화를 통하여 호안 적용성을 검토하였다. 기존의 프리캐스트 불록은 홍수 시 빠른 유속과 집중하중에 유실 및 탈락의 문제점이 나타나고 있으나 이를 보완한 일체형 호안블록 시스템은 홍수시나 수충부에 적합한 호안식생블록 시스템이다. 수리모형실험에서는 성덕댐이 위치한 보현천의 하도에 1/50 축척으로 모형을 재현하고 설계홍수량을 방류하는 조건으로 하도에서 원형과 개발된 블록의 식생유무에 대한 흐름 및 특성의 변화를 검토하였다. 검토결과, 설계홍수량 $200m^3/sec$에서 유속 저감 평균 10.1%, 수위 상승 평균 17.8%의 실험 결과를 얻었다. 연구(II)에서는 수치모형실험을 통하여 실험결과를 검증하고자 하였다.