• 제목/요약/키워드: Operation Strategies

검색결과 942건 처리시간 0.025초

대륙횡단철도 연계운영의 효율화를 위한 기초조사 (A basic Research on the Euro-Asian Continental Rail Corridor for Effective Connection and Operation)

  • 나희승;손지언;조영걸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.534-541
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    • 2004
  • To boost the Korean peninsula as a logistical hub of North-East Asia in 21st century is an important part of Korean development strategies. This research has been conducted on the premise that the connection and operation of the Korean Peninsula break-railway and Euro-Asian railway network will be a great drive for Korean economy and railway technology development. For the preparation to do a further research on this subject, this paper introduces the general condition and related basic material for the railway network operation through the countries along the corridor. It also provides the basic data of railway and actual operation condition in the involved Euro- Asian areas, such as Russia, China, Mongolia, Kazakh-stan, etc.

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Control Strategy against Undesirable Zone 3 Relay Operation in Voltage Instability

  • Lee Byong-Jun;Song Hwa-Chang
    • KIEE International Transactions on Power Engineering
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    • 제5A권2호
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    • pp.144-151
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    • 2005
  • This paper presents a framework for determining control strategies against unwanted tripping actions during relay operation that plays a very important role in cascading events leading to voltage collapse. The framework includes an algorithm for quick identification of possible zone 3 relay operation during voltage instability. Furthermore, it comes up with the control strategy of load shedding at the selected location with active power and relay margin criteria. In addition, Quasi Steady-State (QSS) simulation is employed to obtain time-related information that is valuable in the determination of control strategy. As a case study, an example applying the framework is shown with the modified New England 39-bus system.

마이크로 가스터빈의 탈설계 운전 성능특성 (Performance Characteristics for Off-design Operation of Micro Gas Turbines)

  • 황성훈;김동섭
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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    • pp.80-87
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    • 2003
  • Micro gas turbines are designed with low turbine inlet temperature and pressure ratio. To overcome the efficiency defect of the simple cycle, adoption of the recuperator is an inevitable choice. In addition to the design performance, we should also pay attention to the off-design performance of gas turbines since they usually operate at part-load conditions for a considerable amount of the time. This study aims at analyzing off-design performance characteristics of micro gas turbines and addressing the importance of the recuperator in the part load operation. Comparative analyses have been performed to evaluate the part load performance differences among various design and operating options : simple vs recuperative cycles, single vs two shaft configurations, various operating strategies for the single shaft configuration (fuel only control, variable speed operation, variable inlet guide vane control), and current vs advanced engines. Major finding is that maintaining turbine at high level is crucial in efficient operation of micro gas turbines.

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국내 패션 업체의 그린 마케팅 유형 분류를 통한 지속가능한 그린 패션 마케팅 전략 (The Sustainable Green Fashion Marketing Strategies according to Classification of Green Fashion Marketing of Domestic Fashion Companies)

  • 신수연;홍정민
    • 복식문화연구
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    • 제18권5호
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    • pp.872-891
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    • 2010
  • This study was an exploratory research to classify the types of green fashion marketing of the fashion companies in South Korea and analyse the present cases of each type. To analyse the current cases of green fashion marketing strategies, we researched all sorts of newspapers, magazines, publications of fashion companies, and web sites from 2008 to 2009. As a result, we categorized 5 types of green fashion marketing as follows ; eco-friendly fabrics (natural fabrics, recycled fabrics, biodegradable fabrics), re-use or re-form(reuse after cleaning and/or repairing and reformation through transformation and combination of raw materials), green certifications(ISO 14001, GOTS, OES, etc.), eco-friendly management and operation, and green marketing promotions. Based on the results, we proposed the green marketing strategies for fashion companies to progress toward the proper direction of green marketing. First of all, companies should escape from the narrow view point limited to the product itself. Then they have to focus on developing and execution of sustainable merchandising, manufacturing, logistics, and waste strategies.

사례 연구를 통한 분수 나눈셈의 연산 감각 분석 (An Analysis of Operation Sense in Division of Fraction Based on Case Study)

  • 방정숙;이지영
    • 대한수학교육학회지:학교수학
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    • 제11권1호
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    • pp.71-91
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    • 2009
  • 본 논문은 기본적인 계산능력이 뛰어난 초등학교 6학년 학생 2명을 대상으로 분수 나눗셈 문제를 해결하는 과정에서 나타나는 연산 감각을 분석하였다. 구체적으로 학생들이 분수 나눗셈의 다양한 의미와 모델을 어떻게 이해하고 있는지, 분수 나눗셈 알고리듬의 의미를 어떻게 이해하고 있는지, 그리고 이러한 연산의 의미와 성질을 어떻게 응용하는지에 대해 임상 면담을 통해 면밀하게 탐색하였다. 구체적인 에피소드를 바탕으로 연산감각의 구성요소별로 두 학생의 질적 차이를 분석하고, 이를 기초로 하여 초등학교 고학년에서 연산 감각 자체를 보다 집중적으로 조명해 볼 필요가 있다는 점을 강조하였다.

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Dynamic Operational Strategies of UPFC in the KEPCO Transmission System

  • Chang, B.H.;Choo, J.B.;Lima, Leonardo T.G.;Feltes, James W.
    • KIEE International Transactions on Power Engineering
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    • 제3A권3호
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    • pp.168-176
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    • 2003
  • The Korea Electric Power Corporation (KEPCO) has installed an 80 MY A Unified Power Flow Controller (UPFC) at its 154㎸ 'Kang-Jin Substation in South Korea. The device, manufactured by Siemens & Hyusung, has been operational since October 2002. The Korea Electric Power Research Institute (KEPRI), a division of KEPCO was tasked to study operational strategies that could be employed for the UPFC and surrounding reactive support devices concerning problems of low voltages and overloads in the Mokpo & Gwangju areas. Particular apprehension surrounded the possibility of delay in the installation of a new 345㎸ transmission line from 2005 to beyond 2010. The studies were to specifically determine whether these problems could be eliminated by application of a UPFC. The analysis included determining the UPFC operating point under various conditions, investigations of the coordination between the UPFC and a HYDC line terminating in this area, and the design of a supplementary damping controller for the UFPC. This paper summarizes the results of those studies, demonstrating the dynamic characteristics of the operation of this UPFC operation in the Korean power system.

B2C 인터넷 쇼핑몰 성과에 영향을 미치는 성공요인에 관한 연구 (Research About the Success Factor which has an Influence on B2C Internet Shopping Mall Result)

  • 강현순;김정자
    • 산업경영시스템학회지
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    • 제32권3호
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    • pp.85-92
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    • 2009
  • A lot of B2C Internet shopping mall companies are establishing various strategies in order to make a result to be further better than it. But They are experiencing trouble by restriction like manpower or financial issue. Therefore, frying to grasp how an assistance degree of a company In B2C Internet shopping mall success factors affects will be important information in resources distribution of management strategic which is established by B2C Internet shopping mall company to survives in unlimited competition. In this paper, It is purpose to find which is success factors affecting to a finance and the other part of results in B2C Internet shopping mall companies. In order to achieve a study purpose, we make a model by literature study and inquiries and analysis the result data. Consequently for successful B2C Internet shopping mall operation, it needs a assistance of a company fully. But the company which shall get a maximum effect with resources limited is difficult to assistance fully. This study will be used to establish strategies of distribution of resources appropriately for the company which is not fully assist B2C Internet shopping mall operation because of restrictions of manpower, material and finance.

환경정의를 고려한 교통운영 전략 및 평가에 관한 연구 (A Study on the Strategy and the Evaluation of Traffic Operation Considering the Environmental Justice in Emission)

  • 박준환;김원호;남두희;이영인
    • 대한교통학회지
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    • 제25권3호
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    • pp.7-17
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    • 2007
  • 단순한 배기가스의 양적 감소를 위한 노력에서 벗어나 환경정의와 같은 새로운 이론적 체계 속에서 교통 운영 개선과 대기오염 개선을 함께 살펴보았다. 즉, 환경정의의 관점에서 새로운 목표를 설정하고. 설정된 목표를 달성하기 위한 교통운영 대안들을 마련한 후, 교통 및 환경차원에서 동시에 적용 평가하는 틀을 마련하였다. 이러한 이론적 틀은 교통개선을 통한 환경정의 구현 목표 설정, 교통운영전략 시나리오 수립, 시나리오별 결과 산출, 결과 분석 및 시사점 도출의 과정으로 구성된다. 본 연구를 통해 환경적 요구가 뚜렷하게 강조되어야 하는 경우에는 환경정의가 우선되는 교통운영 개선전략을 마련하고 평가하여 시행할 수 있는 도구를 마련하였다.

현장 규모 biobarrier의 수리학적 특성과 기초 설계

  • 최영화;오재일;왕수균;배범한
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.426-430
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    • 2003
  • Subsurface biobarrier technology has potential applications to contain contaminated groundwater and/or to degrade toxic pollutants in groundwater. Effective biobarrier formation is need to assess of hydrogeologic characteristics and to conduct practical operation strategies and design based on this prior to design biobarrier. Thus, in this study, we examined hydrogeologic characteristics in biobarrier construction site. Hydraulic conductivities which calculated from slug test data have shown difference with each well as 1.20$\times$10$^{-3}$ -6.00$\times$10$^{-5}$ cm/sec. Tracer test is a method in which concentration of tracer solution during withdrawal in each well by vacuum extraction system is measured with time. Tracer solution was continuously injected by constant head tank. Measured tracer concentration versus time data were fitted to analytical solution of convection dispersion equation (CDE). The fitting data of CDE to the measured data at each extraction well yielded were 0.61cm/min(pore velocity), 5.38$\textrm{cm}^2$/min(dispersion coefficient) for discharge rate of 0.47 1/min and 1.75cm/min(pore velocity), 36.34$\textrm{cm}^2$/min(dispersion coefficient) for discharge rate of 0.93 1/min. As a result, we acquired fundamental parameters which need to design biobarrier and operation strategies.

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