• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.85-85
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• 2004

다목적 실용위성(KOMPSAT) 시리즈는 전력버스가 위성의 배터리와 직접 연결되어 있어 버스전압이 배터리와 동일하며, 전력조절기(Power Regulator)의 스위칭 듀티 값이 위성 탑재 소프트웨어에 의해 제어되는 소프트웨어 제어방식의 비조절형 버스 시스템 (Unregulated Bus System)을 사용한다. 본 논문에서는 이와 같은 소프트웨어 제어방식 비조절형 버스시스템을 채택하는 위성의 전력조절기 모듈화에 적용 가능한 새로운 전원단 회로를 제안하며 제안된 전원단의 모드별 동작 특성을 해석하고 시뮬레이션 결과와 비교, 검토한다. (중략)

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.210-213
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• 2001

There has been a steady increase in treatment of wastes buried in unplanned waste landfill situated in urban area and river side. This study was carried out to evaluate the geotechnical and environmental properties of soil sorted by classifier from wastes in unregulated landfill. The physical mechanical, and environmental properties of sorted soil were investigated for treatment of wastes and soil including landfill.

• Journal of the Korean Wood Science and Technology
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• v.35 no.2
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• pp.85-95
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• 2007

Manganese dependent peroxidase (MnP) is the most ubiquitous enzyme produced by white-rot fungi, MnP is known to be involved in lignin degradation, biobleaching and oxidation of hazardous organopollutants. Bjerkandera fumosa is a nitrogen-unregulated white-rot fungus, which produces high amounts of MnP in the excess of N-nutrients due to increased biomass yield. The objective of this study was to optimize the MnP production in N-sufficient cultures by varying different physiological factors such as Mn concentration, culture pH, and incubation temperature. The growth of fungus was optimal in pH 4.5 at $30^{\circ}C$, $N_2$-unregulated white-rot fungus produces high amounts of MnP in the excess N-nutrients. The fungus produced the highest level of MnP (up to $1000U/{\ell}$) with $0.25g/{\ell}$ asparagine and $1g/{\ell}$ $NH_4Cl$ as N source at 1.5 mM $MnCl_2$ concentration, pH value of 4.5 at $30^{\circ}C$. Purification of MnP revealed the existence of two isoforms: MnPl and MnP2. The molecular masses of the purified MnPl and MnP2 were in the same range of 42~45 kDa. These isoforms of B. fumosa strictly require Mn to oxidize phenolic substrates. Concerned to kinetic constants of B. fumosa MnPs, B. fumosa has similar Km value and Vmax compared to the other white-rot fungi.

• Ecology and Resilient Infrastructure
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• v.5 no.4
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• pp.229-245
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• 2018

This study aims to investigate the changes in the riparian vegetated area in the Naeseong stream, an unregulated river, in order to analyze the main factors leading to these changes. For this purpose, the land surface cover in the channel area of the Naeseong stream was classified into 9 categories using past aerial photographs collected between 1970 and 2016, which recorded the long-term changes of the Naeseong stream. The increase or decrease in the vegetated area was calculated for each category using a pair of before and after images. The changes in the vegetated area were divided into 6 periods: the unvegetated channel period (1970 - 1980), the first rapid increase (1980 - 1986), the period of decrease due to flood (1986 - 1988), the period of repetitive man-induced disturbance and vegetation increase (1988 - 2008), the period of gradual vegetation increase (2008 - 2013), and the period of second rapid increase (2013 - 2016). Multiple regression analysis was performed using independent variables representing hydrology, climate, and geomorphology. The major variables found to be involved in the changes in the vegetated area of the Naeseong stream were the discharge during June - July, channel width, and temperature during April - June. Among the three variables, discharge and temperature were respectively the main independent variables in the downstream and the upstream reaches as per a single variable model. Channel width was the variable that distinguished the upstream and downstream reaches of the stream. The implication of the long-term increase in the vegetated area in the Naeseong stream was discussed based on the result of this study.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.1-19
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• 2021

Objectives: Phthalates, which are widely used as plasticizers, have been recognized as endocrine disruptors. In the present study, we provided information on the regulation of these chemicals and summarized the information available on their detection and toxicity in children's products and those of their alternatives. Methods: The regulatory frameworks related to phthalates in children's products in Korea, the United States (US), and the European Union (EU) were compared. Data on the detection concentration of 16 phthalates and seven phthalate alternatives that could be used in polyvinyl chloride (PVC) plastic products for children as well as on their toxicity classification and endocrine disruption toxicity were collected from the literature. Results: Korea adopted US and EU chemical standards for six phthalates (DEHP, BBP, DBP, DINP, DIDP, and DNOP), but not others (e.g., DIBP, DPP, DHP, and DCHP). Among the ten phthalates and seven substitutes for which regulatory standards were not determined, DIBP, DHP, DEHA, DIBA, DINA, and DEHT were detected in children's products made from PVC plastic. DIBP and DHP, which have a reproductive toxicity classification of 1B, were frequently detected in PVC toys. The reproductive toxicity, estrogenicity, and anti-androgenic activity of the unregulated phthalates and their alternatives have been reported in diverse in vitro and in vivo assays. Conclusion: The use of unregulated phthalates and their substitutes in children's products is increasing. Further monitoring and toxicological information on phthalate alternatives is required to develop proper management plans.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.195-204
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• 2018

Pesticide residue in the eggs in the market has become a significant problem in Korea. In particular, the detection of fipronil indicated that unregulated pesticide residue can be present in livestock products, including eggs. Institutionally unregulated pesticides are a risk to human health and the ecosystem. In this study, we analyzed the system of agricultural pesticide management in Korea, the European Union, and the United States of America (USA) and discussed the problems of the Korean management system and the possible improvement directions. Based on the analysis, we considered three tasks: registration of pesticides, pesticide residue levels in food, and pesticide residue levels in environmental media. The registration of pesticides was conducted by the Ministry of Agriculture, Food, and Rural Affairs in Korea; the Directorate-General for Health and Food Safety in the European Commission (EC); and the US Environmental Protection Agency (USEPA) in the USA. The work regarding pesticide residue levels in food was conducted by the Ministry of Food and Drug Safety in Korea, the Directorate-General for the Health and Food Safety in the EC, and the USEPA and Food and Drug Administration in the USA. The work regarding pesticide residue levels in environmental media was conducted by the Ministry of Environment in Korea, the Directorate-General for Environment in the EC, and the USEPA in the USA. Therefore, Korea should review the extension of pesticide residue standards in the environmental media for strengthening the system of management of unregulated agricultural pesticides.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.73
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• pp.91-110
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• 2017

Recently, world wide trading which support free trade will increase the economic volume size. It will grow the quality of life. But, the reduce of gap between the rich state and the poor one has always been risen the problem of one of welfare. Trough unregulated trade activities, multinational corporations succeeded in expanding the market globally. However, there were unfair acts such as infringement of serious rights of producer of low development countries. Fair trade has begun to pay fair value to them and to ease inequality, but, as time went by, the its idea became thinner, distorted in the market, or became a marketing tools. So, In this paper, I analyze the limitations and causes of fair trade and suggest directions for fair trade. This Study provided a causes of the limitation of fair trade and for the future, I'll suggest an alternative of limitation of fair trade.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.93-96
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• 2003

Korea Multi-Purpose SATellite (KOMPSAT) uses software-controlled unregulated bus system In which the main bus is directly connected to a battery and the duty-ratio for PWM switch is generated by the on-board satellite software algorithm. In this paper, we propose a new power-stage circuit that can be available for modularization of a solar array regulator(SAR) which is used in the KOMPSAT. The operations at each mode and current sharing characteristics of the power-stage are analyzed and verified by simulation and experiments on a prototype converter.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.354-359
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• 2006

The analysis of large-scale water resources systems is often complicated by the presence of multiple reservoirs and diversions, the uncertainty of unregulated inflows and demands, and conflicting objectives. Reinforcement learning is presented herein as a new approach to solving the challenging problem of stochastic optimization of multi-reservoir systems. The Q-Learning method, one of the reinforcement learning algorithms, is used for generating integrated monthly operation rules for the Keum River basin in Korea. The Q-Learning model is evaluated by comparing with implicit stochastic dynamic programming and sampling stochastic dynamic programming approaches. Evaluation of the stochastic basin-wide operational models considered several options relating to the choice of hydrologic state and discount factors as well as various stochastic dynamic programming models. The performance of Q-Learning model outperforms the other models in handling of uncertainty of inflows.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.239-242
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• 2009

Power Control and Distribution Unit (PCDU) plays roles of power generation control for solar array panel, power storage control for battery system, power conversion for unregulated and regulated primary bus and power distribution to bus and payload system. The selection and design of the proper auxiliary power interface for PCDU depending on various mission is one of the most important step for electrical power subsystem design. In this paper, the general design approach of auxiliary power interface for PCDU which can be used for small-sized LEO satellites application is given. And, the auxiliary power design concept for always alived modules such as solar array regulator and house keeping module is also suggested.