• Journal of the Chungcheong Mathematical Society
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• v.19 no.1
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• pp.1-8
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• 2006

In this paper, we obtain some unique common fixed point theorems for four self-maps and pair of maps in D-metric space using orbitally lower semi continuity conditions.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.244-245
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• 2013

This paper proposes a control algorithm for permanent magnet synchronous generator with a back-to-back three-level neutral-point clamped voltage source converter in a medium-voltage offshore wind power system under unbalanced grid conditions. The proposed control algorithm particularly compensates for the unbalanced grid voltage at the point of common coupling in a collector bus of offshore wind power system. This control algorithm has been formulated based on the symmetrical components in positive and negative rotating synchronous reference frames under generalized unbalanced operating conditions. Instantaneous active and reactive power are described in terms of symmetrical components of measured grid input voltages and currents. Negative sequential component of ac input current is injected to the point of common coupling in the proposed control strategy. The amplitude of negative sequential component is calculated to minimize the negative sequential component of grid voltage under the limitation of current capability in a voltage source converter. The proposed control algorithm makes it possible to provide a balanced voltage at the point of common coupling resulting in the generated power of high quality from offshore wind power system under unbalanced network conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.147-156
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• 2008

As the management of fuel efficiency becomes globally reinforced in attempts to find an environment-friendly vehicle that will operate against global warming, the interest in and the demand for the type of vehicle with a high-efficiency diesel engine using light oil. However, it also emits a greater amount of PM (particulate matter) and NOx than emissions from vehicles using other types of fuels. Therefore, the DME (Dimethyl Ether), an oxygen containing fuel draws attention as an alternative fuel for light oil that can be used for diesel engines since it generates very little smoke. But to develop and compare performance of an electric controlled common-rail DME engine, engine tests requires optimized injection conditions at required engine RPM and engine torque. These injection conditions cannot be set freely and the data configuration through the experimentally repeated application requires much time as well as a significant amount of errors and effort. The object of this study is to configure the basic injection map using the results of the DME engine experiments performed so far. For this, in this study, the functionalization of the required equations were performed along with the basic review of the factors that had influence on the data map. Through this, the information on the injection pressure, injection amount, injection duration, injection timing, etc. under certain operation condition could be obtained.

• Journal of Institute of Convergence Technology
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• v.3 no.1
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• pp.15-18
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• 2013

The next generation alternative fuel of diesel, DME (Dimethyl Ether) discharges particulate matter hardly due to chemical structural as oxygen-fuel so it has the eco-friendly property. Despite these advantages, the DME has the technical difficulties to apply to the diesel engine because of a low calorific value, viscosity and compressibility effects. From this point of view, we performed experimental studies on improved reliability of DME common-rail vehicle and lubricity enhancement of DME fuel for empirical distribution of eco-friendly DME fuel. Also we analyzed solubility of lubrication enhancer according to a drop in temperature, try to secure reliability about core parts of DME vehicle by applying lubrication enhancer in the DME common-rail vehicle.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.657-664
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• 2019

While the 4^th Industrial Revolution (4^th IR) is actively being discussed in Korea, the core and common point is that in the era of the 4^th IR, computer networking is becoming more common due to the generalization of ICT(Information and Communication Technology). There may be a variety of factors that have allowed ICT to occupy a core position in the 4^th IR, but the most important may be the position of ICT as a foundation technology. ICT has important technical value in itself, but when it is converged with other technology or industry, or when it acts as a foundation technology of such technology or industry, it greatly improves the value of existing technology or industry. Thus, this paper focused on ICT, the core technology of the 4^th IR, to examine the past, present and future of ICT-related R&D and ICT-based convergence industries. In other words, the purpose of this study is to identify which areas ICT has been actively researched from past to present and what changes have been made in such areas.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.323-325
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• 2006

전력계통 에너지관리시스템(EMS)을 위한 공통 정보모델(CIM:Common Information Model)은 1990년대 후반에 EPRI의 CCAPI (Control Center Application Program Interface) 연구 프로젝트에서 시작하여, 현재는 IEC의 국제표준인 IEC 61970시리즈로 등록되어 있다. 특히, CIM은 IEC61970의 Part 301, 302에 정의되어 있는 공통데이터 모델을 지칭하며, IEC61970의 Part 401${\sim}$407에 정의되어 있는 CIS (Component Interface Specification)와 더불어 EMS의 API(Application Program Interface)를 정의하는 핵심 요소이다. CIM (Common Information Model)은 전격회사의 전력 시스템 운영을 포함하여 전력회사 전반에 사용되는 주요한 객체(object)들을 나타내는 추상적 모델(abstract model)이다. 또한, CIM은 전력계통 자원을 객체 클래스들(object classes)과 속성들(attributes)로 표현하는 표준 방법을 제공함으로써, 발전분야나 배전분야와 같이 전력 계통의 운용 영역이 다른 계통들과 EMS 시스템 연계, 독립적으로 개발된 전체 EMS 시스템간의 연계, 서로 다른 판매자에 의해서 독립적으로 개발된 EMS 응용 프로그램간의 통합을 용이하게 한다. 본 논문에서는 전력계통 공통 데이터 모델인 IEC 61970을 소개하고, 이에 기반을 둔 한국형 EMS 데이터베스 구축에 관해 설명한다.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.1
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• pp.113-128
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• 2015

As the major developed countries of the world have realized the importance of common information and its utilization, they have begun to seek a plan that will facilitate manipulation of common information. Despite development of the National R&D activities and its quantitative increase in Korea, its practical use still remains at a lower level. Therefore, it is worthwhile to analyze practical use and economic contribution in order to achieve higher profits. There are two purposes of this study. The first purpose is to draw a conclusion by analyzing the practical uses of the National R&D Reports, and the second purpose is to evaluate economic contributions by the National R&D Reports. In order to achieve the objectives of this study, literature review, survey, focus group interview, and experts' consultation were conducted as a way to deepen research, simultaneously comprising the quantitative and qualitative methods.

• Journal of Information Technology Services
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• v.11 no.2
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• pp.185-196
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• 2012

The rapid evolution of ICT industry brings not only new services or products but also changes from common individual life to whole human society. Coping with these situations and survival, companies cannot help regarding R&D as the most important thing. So, discovering R&D projects which are suitable for the alternation is a big issue for many companies. To resolve the issue, KT has adopted Innovative Management Methodology developed by Strategos, which is co-founded by Gary Harmel. This paper describes this Innovative Management Methodology tailored to KT R&D. The methodology consists of five phases : focusing discovery, discovery, ideas/domains, domain elaboration & aiming point and R&D project proposal. Also, it shows some interim findings that came from the Innovative Management Process. Finally, the future plan for elaborating the methodology itself and generating new R&D projects is suggested.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.208-210
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• 2008

We have developed a LCD Panel that form storage capacitance for pixels between pixel electrode of bottom glass and common electrode of top glass. This method could make higher transmission and higher production yield than before by removing storage electrode line and capacitance on the bottom glass by simplifying bottom pixel structure.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1582-1590
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• 2011

An analysis of the railroad industry for R&D investments has been insufficient whereas there are lots of analysis of accumulation of technology, economic performances and ripple effects for macroscopic view and other industry of R&D investments. This study decided intellectual rights, patent, and paper as common indicators of scientific and technological performances for setting up performance targets through surveying and analysis of preceding study and verified a appropriateness of scientific and technological performances for railroad R&D 11 projects which were successfully finished. Preceding study has been set up performance targets by research investments as input, but this study made a performance target by model through a cross-sectional and residual analysis of performances of railroad R&D 11 Projects in applying research investments, capital investments, inner labor cost and inner labor cost per man and research time as inputs, and verified a validity and a empirical analysis through analysis of other project.