• Environmental Engineering Research
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• 제21권1호
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• pp.91-98
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• 2016

Along with China's increasing share in global total $CO_2$ emissions, there is a necessity for China to shoulder large emission-mitigating responsibility. The appropriate allocation of $CO_2$ emission quotas can build up a solid foundation for future emissions trading. In views of originality, an optimized approach to determine $CO_2$ emissions allocation efficiency based on the zero sum gains data envelopment analysis (ZSG-DEA) method is proposed. This paper uses a non-radial ZSG-DEA model to allocate $CO_2$ emissions between different Chinese provinces by 2020 and treats $CO_2$ as the undesirable output variable. Through the calculation of efficiency allocation amounts of provincial $CO_2$ emissions, all provinces are on the ZSG-DEA efficiency frontier. The allocation results indicate that the cumulative optimal amounts of $CO_2$ emissions in 2020 were higher than the actual amounts in 13 provinces, and lower in other 17 provinces, and show that different provinces have to shoulder different mitigation burdens in terms of emission reduction.

• 제어로봇시스템학회논문지
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• 제7권3호
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• pp.209-217
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• 2001

In this paper, we propose a linear quadratic regulator(LQR) controller design for the active suspension using evolution strategy(ES) and neural network. We can improve the inherent suspension problem, the trade-off between ride quality and suspension travel by selecting appropriate weight in the LQR-objective function. Since any definite rules for selecting weights do not exist, we replace the designers trial-and-error method with ES that is an optimization algorithm. Using the ES, we can find the proper control gains for selected frequencies, which have major effects on the vibrations of the vehicle. The relationship between the frequencies and proper control gains are generalized by use of the neural networks. When the vehicle is driven, the trained neural network is activated and provides the proper gains for operating frequencies. And we adopted double sky-hook control to protect car component when passing large bump. Effectiveness of our design has been shown compared to the conventional sky-hook controller through simulation studies.

• 전기전자학회논문지
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• 제24권1호
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• pp.106-119
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• 2020

본 논문에서는 극 배치 기법을 활용하여 쿼드로터 시스템의 제어기법을 제안한다. 일반적으로 상태 궤환 제어기를 사용하여 제어된 시스템 성능을 개선하기 위해서는 많은 제어 이득 값 선정에서의 시행착오가 필요하다. 이러한 복잡성을 완화시키고, 체계적인 제어 이득 선정을 위해 쿼드로터의 폐루프 시스템을 분석한다. 시스템 성능을 개선시키기 위해 극 배치 기법을 활용한 제어 이득 결정 알고리즘을 제안한다. 제안된 제어기법은 실제 시스템인 쿼드로터에 적용하여 유효성을 입증한다.

• 전자공학회논문지
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• 제51권7호
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• pp.82-88
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• 2014

본 논문에서는 두 개의 이득 값을 가지는 전압제어발진기를 이용하여 루프필터 커패시턴스 유효 용량을 배가 시켜 칩 크기를 줄일 수 있는 위상고정루프를 제안하였다. 제안된 위상고정루프에서는 양/음의 두 개의 이득 값을 가지는 전압제어발진기로 루프 필터의 커패시턴스 유효 용량을 배가 시켜 루프필터 커패시터 크기를 1/10로 줄였다. 제안된 위상고정루프는 1.8V $0.18{\mu}m$ CMOS 공정을 이용하여 설계되었다. 시뮬레이션 결과는 기존 구조와 같은 잡음 특성과 위상고정 시간을 보여주었다.

• East Asian Economic Review
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• 제24권3호
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• pp.207-235
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• 2020

Acknowledging that individuals dislike having low relative income renders trade less attractive when seen as a technology that integrates two economies by merging separate social spheres into one. We define a "trembling trade" as a situation in which gains from trade are less than losses in relative income, with the result that global social welfare is reduced. We show that a "trembling trade" can arise even when trade is more gainful in four ways: through trade the absolute income of everyone increases, the income gap in both economies is reduced, as is the income gap between the trading economies. However, trade brings populations, economies, or markets that were not previously connected closer together in social space. As a consequence, separate social spheres merge, and people's social space and their comparators are altered. Assuming that people like high (absolute) income and dislike low relative income, the aggregate increase in unhappiness caused by the trade-induced escalation in relative deprivation can result in a negative overall impact of trade on (utilitarian-measured) social welfare, if the absolute income gains are not large enough to mitigate the relative income losses.

• 한국가스학회지
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• 제3권1호
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• pp.64-74
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• 1999

정상상태 이득을 사용하여 제어 시스템 변수들간의 상호작용 해석 및 루프 페어링을 위한 판별기준을 제시하였다. 음 함수(implicit function)의 미분 관계를 고려하여 유도한 판별기준을 이용하여 조작 변수들과 제어 변수들간의 SISO pairing 및 부분적 MIMO pairing을 합리적으로 정할 수 있었으며, 기존의 기준이 해석하지 못한 대각선 정상상태 이득에 대한 대각선에 있지 않은 정상상태 이득의 영향을 효과적으로 고려할 수 있었다. 그리고 여러 경우에 대해 적용 예제들을 통하여 제시한 기준의 검증과 응용성을 알아보았다.

• 한국정밀공학회지
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• 제30권10호
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• pp.1031-1039
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• 2013

This paper presents gain optimization of a 6-DOF underwater robotic platform with 4 rotatable thrusters. To stabilize the 6-DOF motion of the underwater robotic platform, a back-stepping controller is designed with 6 proportional gains and 6 derivative gains. The 12 gains of the backstepping controller are optimized to decrease settling time in step response in 6-DOF motion independently. Stability criterion and overshoots are used as a constraint of the optimization problem. Trust-region algorithm and hybrid Taguchi-Random order Coordinate search algorithm are used to determine the optimal parameters, and the results by two methods are analyzed. Additionally, the resulting controller shows improved performance under disturbances.

• Journal of Korea Trade
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• 제25권8호
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• pp.25-44
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• 2021

Purpose - This research aims to provide empirical evidence that highlights the importance of imported intermediate goods in long-term economic growth. To this end, this paper develops an index that measures the productivity gains associated with a country's intermediate goods imports using highly disaggregated trade data. Design/methodology - The basic hypothesis is that countries sourcing higher-productivity (or higher-quality) inputs from developed economies derive a larger benefit from foreign R&D. To explore this hypothesis, standard cross-country growth regressions are performed using the highly disaggregated data from the United Nations (UN) Commodity Trade Statistics Database (COMTRADE). To address the endogeneity issue, I apply an instrumental variable (IV) approach. Findings - The results of this study demonstrate that the index predicts subsequent economic growth in middle- and low-income countries. This finding is consistent with previous studies that have argued that developing countries can achieve substantial productivity gains by importing intermediate inputs from developed countries. By contrast, there is no evidence of a significant association between the index and economic growth in high-income countries. Originality/value - This paper contributes to our understanding of the causal relationship between international trade and economic growth. From an economic policy perspective, the results suggest that developing countries with limited technology endowment can boost growth from input-tariff liberalization.

• 한국인구학
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• 제9권2호
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• pp.13-29
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• 1986

This study was carried out to calculate working life expectancy and its potential gains according to the degree of reduction in the specific causes of death. It sought to ascertain what potential gains in labor force longevity might be reasonably achieved through efforts to reduce mortality from injuries and poisoning, diseases of circulatory system, neoplasms and the other causes of death. The data were drawn from the three sources such as "The 1982 Causes of Death Statistics," "Abridged Life Table for Korea 1978~'79" and "The 1982 annual Report of Economically Active Population" issued by Economic Planning Board. Analytical tools used in this study were the cause-deleted life table and the Wolfbein Wool's working life table method. Partial life expectancy was adopted as an index of this study, This application will be widely used as a good demographic tool for analyzing the dynamics of labor force and causes of death. Some of the findings are summerized as follows. 1. Partial life expectancies from initial age 15, 25, and 45 respectively to terminal age 65 are 44.86, 35.59 and 17.41 year in life expectancy itself, 37.08, 32.83 and 15.21 year in working life expectancy, 7.78, 2.76 and 2.20 years in inactive life years. 2. Potential gains in working expectancy from initial age 15, 25 and 45 to terminal age 65 by the complete elimination of the specific causes of death are 1.36, 0.94 and 0.27 years in injuries and poisoning, 0.88, 0.83 and 0.54 years in diseases of circulatory system, 0.56, 0.54 and 0.37 years in neoplasms, 1.13, 1.02 and 0.58 years in the other causes of death. The relationship between degree of reduction in causes of death and potential gains in working life years is in direct proportion. The prime orders of reduction effectiveness in age groups by the causes of death are injuries and poisoning in age 15-24, the other causes of death in age 25-49 and diseases of circulatory system in age 50 and over. 3. If it were possible to reduce 25%, 50% and 75% in mortality condition 1978~'79, the average length of working life would be 38.08, 39.13 and 40.17 years in age 15, and 33.68, 34.57 and 35.44 years in age 25, and 15.67, 16.14 and 16.63 years in age 45.

• 벤처혁신연구
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• 제1권1호
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• pp.83-98
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• 2018

본 논문은 최근 생겨난 장외시장인 K-OTC 시장에서 금융상품이 거래되어 과세될 경우 거래세와 양도세의 차이에 대해 이론적으로 접근해 보고자 한다. 또한 합성채권을 구성하여 위험을 헤지하고자 할 때 포트폴리오로 구성된 금융 상품의 과세 방법에 따라 투자자들이 추구하는 수준까지 위험을 줄이기 어렵기 때문에 이를 효과적으로 적용할 수 있는 조세 방법을 살펴보고자 한다. 무엇보다 합성채권의 과세 형평성을 구체적으로 살펴보기 위해 K-OTC 시장 안에서 기말주가변화와 행사가격변화에 따라 합성채권에 부과된 거래세와 양도세의 효과 및 소득공제 유무에 따라 어떻게 세후이익이 차이가 나는지 분석해 보고자 하였다. 연구 결과 기말 주가변화에 따른 거래세와 양도세의 조세 갭을 통해 거래세 효과가 양도세 효과보다 조세 갭이 훨씬 적으므로 어느 정도 복제포트폴리오로 헤지를 구성함에 있어서는 거래세를 부과하는 것이 조세 정책적 목적 및 금융시장 측면에서 조금 더 효율적일 수 있음을 보여주었다. 또한 소득공제 허용 여부는 행사가격의 변화에 따라 거래세와 양도세의 효과가 차이가 있음을 나타내었다. 무엇보다 행사가격이 주가보다 낮아지면 거래세가 양도세보다 소득공제 유무의 영향을 덜 받는 것으로 나타났으나, 행사가격이 주가보다 높아지면 거래세와 양도세 모두 소득공제 유무의 영향이 동일함을 알 수 있었다. 앞으로의 과제는 실제 금융상품을 대상으로 K-OTC시장에서 실증 검증하는 것이며 아울러 옵션 거래세를 산정함에 비율 분석으로 접근하여 좀 더 체계적인 헤지 방법을 찾아보는 것이다.