• Proceedings of the KIEE Conference
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• 2000.07c
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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.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.343-344
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• 2005

• Magazine of the Korean Society of Agricultural Engineers
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• v.8 no.2
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• pp.1110-1118
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• 1966

• Magazine of the Korea Concrete Institute
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• v.15 no.3
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• pp.80-86
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• 2003

• Asian Journal of Business Environment
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• v.11 no.3
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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.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.44
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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.

• Korean Journal of Community Nutrition
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• v.11 no.5
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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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• v.6 no.4
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• pp.217-226
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• 2019

Optimum engineering methods for bank protection were classified based on steepness of bank slope and an existence of waterfront facility in the floodplain, and a new concept of eco-hybrid rolling mat method which could be applicable for the unfitted cases with previously developed countermeasures was suggested in this study. The eco-hybrid rolling mat method can be constructed while maintaining the river environment and ecosystem that does not interfere with the ground and slopes, when bank erosion occurs, it is an economical and efficient construction method that can protect the revetment and the bank slope immediately. The developed eco-hybrid rolling mat method was verified for the designed structure, system, function and effect based on large-scale river experiments including field exposure and decomposition test. As a result, the normal operation and effect of the rolling mat ted under low and high velocity conditions were confirmed with respect to bank protection. The effect of bank erosion prevention was quantitatively validated by sediment concentration monitoring and analysis, and the product specification of the eco-hybrid rolling mat was presented based on the standardized mat applied in real-scale tests.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.12
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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 ㎸.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.87-97
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• 2008

This research focused on development and application feasibility for the coalesced continuous block system in river bank protection. Most of block systems in river bank are pre cast type and have some difficulties against high velocity flood condition or high pressure load, however, the continuous block system can be applied to flood damage recover as well as environmental vegetation block system in river bank. For the application review and analysis of hydraulic condition for this block system, hydraulic physical modeling was carried out. The physical model was built as a scale of 1:50 by Froude similitude measuring the water levels and the water velocities for vegetation application or not. In consequence, the water velocities were observed to decrease meanly 10.1%, and the water depths were to increase meanly 17.8% in case of the of design flood, $Q=200m^3/sec$. To verify the hydraulic physical modeling, the numerical modeling should be conducted for a close examination of vegetation application by one or two dimensional numerical analysis as a next study.