• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.9-20
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• 2018

When a large-scale photovoltaic (PV) system is introduced into a distribution system, the customer's voltage may exceed the allowable limit ($220V{\pm}6%$) due to voltage variations and reverse power flow in the PV system. In order to solve this problem, we propose a method for adjusting the customer voltage using the existing step voltage regulator (SVR) installed in the primary feeder. However, due to the characteristics of a mechanically operating SVR, the customer voltage during the tap changing time of the SVR is likely to deviate from the allowable limit. In this paper, an energy storage system (ESS) with optimal operation strategies, and an appropriate capacity calculation algorithm are proposed, and the parallel driving scheme between the SVR and the ESS is also proposed to solve the customer voltage problem that may occur during the tap changing time of the SVR. The simulation results show that the allowable limit of the customer voltage is verified by the proposed methods during the tap changing time of the SVR when the large-scale PV system is connected to the distribution system.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.5
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• pp.486-492
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• 2013

Energy cost has been increasing rapidly to comply with environmental regulations worldwide and the manufacturing industry who consumes more than half of the total energy needs to improve their cost competitiveness considering environmental costs. Machine tools are essential elements in manufacturing industry and efforts have been made recently to increase their energy efficiency mainly by German and Japanese machine tool builders. In this paper, trends in energy saving technology are described on the hardware and software sides of peripheral equipment of machine tools. In addition, the power consumption of a machining center is measured and analyzed to develop a software-based standby strategy for energy saving with peripheral equipment of machine tools.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.169-170
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• 2012

현대전에서는 인명 손실을 최소화하는 동시에 타 전투체계와의 연계를 통해 부여된 임무를 성공적으로 이끌어 내기 위해 무인로봇을 활발하게 이용하고 있다. 본 논문에서는 미래 전장에서 중심 역할을 수행할 것으로 기대되는 무인로봇과 통제장치의 기능을 제안한다. 통제장치는 디지털 지도를 기반으로 무인로봇의 위치를 전시하는 동시에 특정 위치로의 자율 이동 명령을 내리게 하는 인터페이스이다. 통제장치에서 무인로봇의 실시간 이동 간에 디지털 지도 기반 가시선(line of sight) 분석을 수행함으로써 통신 가능지역 식별 및 중계기를 통한 통신 가능 영역 식별을 용이하게 한다. 제안한 무인로봇과 통제장치를 통해 전장 환경에서 부여된 작전을 성공적으로 이끄는데 주된 역할을 수행할 것으로 기대한다.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.440-442
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• 1999

본 연구에서는 전자연동장치의 확장성과 신뢰성 제고를 위해 전자연동장치의 실시간 연동전략으로 활용될 수 있는 연동 지식베이스를 자동 생성, 구축할 수 있는 지능형 연동지식베이스 자동 구축 소프트웨어(IIKBAGS)를 개발한다. IIKBAGS의 추론부는 주어진 역 모델의 동적탐색하에서 휴리스틱 규칙들의 우선순위에 따라 모든 진로를 탐색함은 물론 각 진로들에 대해 진로상 신호설비들간의 연쇄관계를 확인하여 연동패턴들을 자동생성하는 연동지식 자동생성기능을 가진다. 지식베이스는 전자연동장치상의 실시간 전문가 시스템이 직접적으로 활용할 수 있는 구조로 설계됨으로써 연동도표 입력과정에서 발생할 수 있는 오류를 배제, 연동장치의 정확성과 신뢰성을 높인다.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.1
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• pp.27-33
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• 2001

This paper presents a digital instrument for a DSP based power quality analysis in three phase power system where current waveform is non-sinusoidal. it is based on stand alone type TMS320C31 DSP(digital signal processor)board and on a special high-speed data acquisition system. Power quality of low power motor drives are analyzed and processed by using a simple average power algorithm, and result of power analysis are displayed by LCD in the proposed system. This paper also goes on to discuss the performance of an instrument prototype, both in terms of accuracy and speed of measurement under the transient and steady state condition.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.43-50
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• 2002

Competition to attract the increasing container cargoes of North China and the West Japan in North-East Asia region is fairly intensed in recent days between the main ports of Korea, China, and Japan. Inducing a new container cargo make those countries possible to invest enormous fund to mordernize its port facilities, as well as to improve efficiency in Port operation and management. In this situation, Strategy to attract transshipment cargoes is of the immediate necessity, This study, therefore, aims to establish the feasible strategies to attract transshipment container cargoes in the North-East Asian region by empirical analysis, he major output of the research is as follows : First, Busan Port to attract transshipment cargoes is required to adjust port tariff and free storage period with flexibility for liner shipping companies and freight forwarder. Second, Price-Demand function of Busan port between main competitive ports in North-East Asian region that is derived from strategies to attract transshipment cargoes, helps marketing manager to fix scientifically port price as understanding the change of demand quantity.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.20-26
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• 2007

• 전기의세계
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• v.38 no.5
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• pp.18-24
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• 1989

논문에서는 PLS(Pohang Light Source)의 linac의 control system을 분산 시스템의 개념하에서 개발하는 입장에서 그 기능적 요구조건을 분석해보고 그에 따른 시스템 설계 및 추진전략에 대해 개괄적으로 기술해 보고자 한다.

• Journal of Korea Port Economic Association
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• v.24 no.4
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• pp.1-23
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• 2008

In order for Busan New Port to secure more trading volumes than the competing ports at home and abroad, an alternative plan for the new port management policy needs to be sought. By the way, aiming to minimize trial and error while maximizing effect in establishing and driving the new port management policy, there is necessity of referring to the developmental strategies of the advanced ports such as Singapore and Hong Kong that are possessing the globally leading position as well as maximizing the substantial value added and the employment-creation effect even qualitatively. Accordingly, the purpose of this study is to propose for a reasonable development strategy for Busan New Port in line with conditions and characteristics of Busan New Port by comparing and analyzing conditions and characteristics of these two advanced ports and by comparative analysis on the developmental strategy according to this.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.421-430
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• 2014

The greenhouse gas emission generated by idling vehicles is a critical issue in the greenhouse gas reduction from the transportation sector. Recently, the mandatory application of the Idle Stop and Go (ISG) for buses, trucks and taxis is in the process of legislation. Focusing on the regulation is about to apply to passenger cars, this study analyzed the quantitative economic effects of the ISG installation by passenger car types in Seoul metropolitan area to support proper policy making. The benefit cost ratio of ISG installation on commercial passenger car of Seoul is the most effective, calculated as 8.55. Accordingly, the amount of 660 liters (per year per vehicle) of fuel and 1,606 kg (per year per vehicle) of $CO_2$ could be reduced. The results of this study might be used as an index for judgment of policy such as determining appropriate subsidy for ISG installation on passenger cars.