• Journal of Power Electronics
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• v.13 no.4
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• pp.516-527
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• 2013

This paper presents a new overall system for state-of-available-power (SoAP) prediction for a lithium-ion battery pack. The essential part of this method is based on an adaptive network architecture which utilizes both fuzzy model (FIS) and artificial neural network (ANN) into the framework of adaptive neuro-fuzzy inference system (ANFIS). While battery aging proceeds, the system is capable of delivering accurate power prediction not only for room temperature, but also at lower temperatures at which power prediction is most challenging. Due to design property of ANN, the network parameters are adapted on-line to the current battery states (state-of-charge (SoC), state-of-health (SoH), temperature). SoC is required as an input parameter to SoAP module and high accuracy is crucial for a reliable on-line adaptation. Therefore, a reasonable way to determine the battery state variables is proposed applying a combination of several partly different algorithms. Among other SoC boundary estimation methods, robust extended Kalman filter (REKF) for recalibration of amp hour counters was implemented. ANFIS then achieves the SoAP estimation by means of time forward voltage prognosis (TFVP) before a power pulse occurs. The trade-off between computational cost of batch-learning and accuracy during on-line adaptation was optimized resulting in a real-time system with TFVP absolute error less than 1%. The verification was performed on a software-in-the-loop test bench setup using a 53 Ah lithium-ion cell.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.2
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• pp.77-85
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• 2018

Renewable energy has been increasingly used and widely acclaimed as one of the solutions to rampant environmental problems. Among numerous kinds of renewable sources, the penetration rate of the PV system is relatively higher than that of others due to ease of installation. However, one disadvantage of the PV system is its dependence on weather condition. The PV system is especially critical when it is used for standalone systems because it cannot operate when the power generated from a PV module is not enough. Therefore, PV systems are often used with an energy storage system, such as batteries, to store backup energy when the weather condition is insufficient to supply power to the system. Blackout time can be reduced by increasing the size of the energy storage system, but it is a trade-off with system cost. In this work, optimal sizing of a standalone PV system is proposed to supply power to the system without blackout. The sizing of PV modules and batteries is performed by a simulation based on actual irradiation data collected during the past five years. The Life cycle costing of each system is evaluated to determine an optimal set of PV modules and batteries among several different combinations. The standalone PV system designed by the proposed method can supply power to the system with no interruption as long as the weather condition is similar to those of the past five years.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.149-156
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• 2023

This research tried to develop an ESS electricity trading system linked with blockchain for energy participation consumers. For the purpose of publishing renewable energy ESS power amount and demand information, we will build a smart contract system on the blockchain DB, utilize the blockchain DB data of energy prosumers and consumers, and expand the power trading market flexibly. to provide realistic solutions. Therefore, the main contents of the development of the ESS power trading system linked to the blockchain are cloud-based web construction for ESS management, coin issuance and exchange registration for activating the blockchain, and to reflect the blockchain technology, building a blockchain database for collecting and supplying ESS-based production demand data, selecting a blockchain-based platform and building a foundation, and creating a smart contract, etc.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.143-149
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• 2018

Recently, President Donald Trump signed FOSTA (Fight Online Sex Trafficking Act) in April 11, 2018, which makes online service no more immune from civil liability for the action of third party facilitating sex trafficking content. Although it is also important to enhance security regulations and cognition on law, but it will be economically more effective to put more energy on preventing recidivism. For John School in Korea, it should increase implementation rate by putting core manpower and budget for preventing needs of sex purchase and then, check operation method and efficacy to improve the actual program. One way is first, empirical analysis and data is required on efficacy of John School program. Second, should have clear definition in Special Sex Trade Law. Third, more strick regulation for selecting participant is required. Fourth, more manpower and budget is required. Fifth, charging the participant for educational fee shall be reviewed. Sixth, educational program should be reviewed. The most important point of education is to make those criminals feel guilty about financially purchasing the sex, basically making them to recognize that it is ethically wrong. However, the current education system contains no clear explanation about the ethical issue of such problem but focusing more on other factors such as sexual disease and structural problem of sexual business. Therefore, this failed to deliver the right psychological training to those criminals without any ethical control. Knowing why women feel hurt when having unwanted sexual relationship by being paid is required part in terms of education for preventing sex trafficking.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.68
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• pp.123-148
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• 2015

Central Asian Countries had been independent in 1991 from USSR. Since then it have been increasing foreign trade and investment amount with outside countries including China, Japan, EU and South Korea. Korean enterprises and entities have endeavored to secure plentiful natural resources, oil and gas energy and expand the market share to exporting the consuming and industrial competitive goods and services for those countries. In the case of disputes of commercial transactions and investment, arbitration is regarded as a dispute resolution system which has been preferred in international transactions and investments by the business world. Since the collapse of the USSR, Central Asian Countries have worked to modernize its arbitration law and procedure to conform with international standard rules. Arbitral legislation in Central Asian countries is based on the Model Law as adopted in 1985. However, CIS's legislation systems of arbitration are not satisfied with the international standard in national laws and practices. That is the reason to consider for the specific parliament about arbitration for the dispute resolutions in the commercial transaction and investment between Korean enterprises and CIS. In this article, it is discuss problems and its alternatives in the dispute resolution about the commercial transaction and investment into Central Asian countries including the tendency to the increasing the trade volumes of goods and investment between South Korea and CIS. According to this article, South Korea consider the long term strategy followed the preferred economic relative partnership for business success on commercial transaction and investment with the Central Asian Countries.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.550-564
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• 2020

Distillation columns are one of the main equipment used for the separation of chemical components in petrochemical process design. However, in spite of the efficient operation in wide range, and the advantage of data collection for equipment verification, the distillation columns are inherently known for high energy consumption and capital cost. Hence, the trade-off analysis needs to be done between investment cost and operation cost to develop the most economical distillation columns. This study was conducted using Aspen Plus, a popular process simulation program, in the pursuit of broad application by as many process engineers as possible. In this paper, design variables for optimization of distillation columns were defined to improve emphatically the design quality with reducing erratic practice of many engineers. In addition, by eliminating unnecessary reviewing step and establishing systematic and efficient procedures, the amount of time for design and human resources were minimized. Aspen Process Economic Analyzers (APEA) program was introduced in order to calculate the investment cost reliably, and the efficient systematic procedure for utilization of APEA was established.

• Journal of Arbitration Studies
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• v.17 no.2
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• pp.141-165
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• 2007

This study aims to make a contribution to the promotion of trade and economic development of South Korea, and, at the same time, call attention to the increasing trend of investment agreements concluded within Free Trade Agreements (FTA) by examining theoretically FTAs and dispute resolution and investigating systematically the conclusion procedure of agreements, and the system, institutions, and jurisdiction of dispute resolution, and presenting these findings to the government and investors involved. The most problematic aspect in the legal process of arbitration involving disputes over investment is that of arguments concerning the right of jurisdiction. When a dispute arises, even though an investor files for arbitration at an ICSID institution, the parties become involved in another energy-consuming argument even before proceeding to the hearing and decision of the original plan in cases in which the respondent of the dispute files an objection to the decision rights of the arbitral tribunal. As the main basis for this type of plea, the point of non-existence of jurisdiction is first raised where the applicable dispute does not fall under the range of investments defined in individual investment contracts or investment agreements such as a Bilateral Investment Treaty (BIT). To avoid an open-ended definition of investment for the range of investments, articles concerning investments in the FTA and NAFTA between Canada and the USA adopt the limited closed-list method. Article 96 of the FTA between Japan and Mexico applied the same abovementioned method of limited form of definition regarding range of investments and concluded BITs between member countries of APEC applied a similar method as well. Instead of employing the previously used inclusive definition, the BITs concluded between countries of Latin America and the USA are equipped with limited characteristics of an investment. Furthermore, to correspond with this necessary condition the three following requirements are needed : 1) fixed investment funding; 2) expected profits resulting from such investments; 3) and the existence of fixed risk bearing.

• KIEAE Journal
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• v.16 no.4
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• pp.63-69
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• 2016

Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.461-461
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• 2018

우리나라를 포함하여 전 세계적으로 기후변화로 기인하는 기상변동성 증가 등의 원인으로 물, 식량, 에너지의 시공간적 불균형이 발생할 것으로 전망되고 있다. 특히 미국 캘리포니아 2012-2015 대가뭄, 우리나라의 2013-2015 대가뭄 등 물부족의 위험 가능성이 증폭됨에 따라, 이와 관련된 에너지와 식량 등의 연계자원들도 기존의 방법과 같이 관리되고 활용하는 것에 한계점이 도달하고 있다. 기후변화와 같이 기상학적 스트레스 증가와 더불어, 국제적으로 인구증가 및 도시화가 확대될 것으로 전망되며, 한국, 미국, 중국, 인도 등에서 물안보에 대한 우려가 현실로 다가오고 있으며, 세계경제포럼(world economic forum)의 "전 지구적 위험도 인지 조사"에서도 물, 식량, 에너지 위기에 대한 심각성을 강조하고 있다. 물, 식량 그리고 에너지는 서로 밀접한 연관성을 가지고 있으며, 개별 분야에서의 문제는 그 자체의 위기로 그치지 않고 다른 타 분야의 위험도를 증폭시키는 원인으로 작용하게 된다. 과거와 다르게 교통, 물류 등의 발달로 물, 식량 및 에너지의 국가간 의존도가 더욱 증가하는 방향으로 전개되고 있으며, 세 가지 자원의 연계성 강화는 결국 상호위기를 선제적으로 대응할 수 있는 방법으로 전망된다. 따라서 물안보 및 물복지 실현을 위한 물과 에너지의 저비용, 고효율의 최적화 방안은 상당히 중요한 요인이 될 수 있다. 이를 위해 본 논문에서는 자원간 Trade-off, 평가 등 에너지소비를 줄이고 에너지 효율성을 증가하며 에너지 절약형 기술에 개발에 중점을 두는 방안을 찾아야 한다. 또한 원예시설 및 관개 기술의 개선에 따른 물과 에너지 소비량 비교 분석, 시설원예 산업의 에너지 생산성 및 절약형 기술 등 에너지-물-식량 분야의 상호연결을 정량화하고 최적화하는 방안들을 지속적으로 모색해야 할 필요가 있다.

• Environmental and Resource Economics Review
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• v.30 no.3
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• pp.471-501
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• 2021

We measure Environmental Efficiency (EE) based on CO₂ in four income groups from 1998 to 2018, using the Meta Stochastic Frontier Analysis method by Input Distance Function. Our results showed that economic growth and energy consumption would increase carbon dioxide emissions, and increasing labor and capital input will reduce it. Moreover, we compared Group Environmental Efficiency (GEE), Meta Environmental Efficiency (MEE), and Environmental Gap Ratio (EGR). The results showed that GEEs were be overestimated. Furthermore, the MEE showed a downward trend during this period. The lower-middle-income group had the highest EGR performance. High-income and upper-middle-income groups showed less efficiency in MEE and EGR. To improve environmental efficiency, we must reduce fossil fuels and find more scientific and technological ways to solve existing environmental problems as soon as possible.