• Title/Summary/Keyword: starting system

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A Study on High Efficiency Operation Method and Design of Power Control Mechanism for Small Wind Turbine System (소형 풍력발전 시스템의 고효율 운용 방법 및 출력 제어 장치 설계에 관한 연구)

  • Bang Jo-Hyug;Oh Kyung-Won;Park Jong-Ha;Kong Chang-Duk
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.10a
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    • pp.210-214
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    • 2004
  • This study proposes a design method for blade pitch control mechanism in order to regulate the power and to improve the starting characteristic. This power control unit which is assembled by spring and mass is planing to equip with 1kW class wind turbine system which is developed for low wind speed area like Korea. For the design of this control unit, the proper geometry of the hub was designed and the calculation of the mechanics was carried out. Especially, It is expected that the operational efficiency will be improved because of additional high pitch starting function by using 2 step spring structure.

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A RESEARCH ON SEAMLESS PLATFORM CHANGE OF REACTOR PROTECTION SYSTEM FROM PLC TO FPGA

  • Yoo, Junbeom;Lee, Jong-Hoon;Lee, Jang-Soo
    • Nuclear Engineering and Technology
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    • v.45 no.4
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    • pp.477-488
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    • 2013
  • The PLC (Programmable Logic Controller) has been widely used to implement real-time controllers in nuclear RPSs (Reactor Protection Systems). Increasing complexity and maintenance cost, however, are now demanding more powerful and cost-effective implementation such as FPGA (Field-Programmable Gate Array). Abandoning all experience and knowledge accumulated over the decades and starting an all-new development approach is too risky for such safety-critical systems. This paper proposes an RPS software development process with a platform change from PLC to FPGA, while retaining all outputs from the established development. This paper transforms FBD designs of the PLC-based software development into a behaviorally-equivalent Verilog program, which is a starting point of a typical FPGA-based hardware development. We expect that the proposed software development process can bridge the gap between two software developing approaches with different platforms, such as PLC and FPGA. This paper also demonstrates its effectiveness using an example of a prototype version of a real-world RPS in Korea.

A Study on University Students' Business Planning and Starting up a Business in Korea (우리나라 대학생들의 창업 및 사업계획에 대한 연구)

  • Koh, In-Kon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.2
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    • pp.1-8
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    • 2012
  • Recently the youth starting up a business has become a buzzword. Business plan is a fundamentals in starting up a business. Therefore, in this study, I investigated the business planning behavior of university students in Korea. Especially, I investigated whether university students in Korea dealt with business plan inside and outside or not, and examined university students' thought whether corporate performance is related to business plan or not, and if any, how closely they are. Meanwhile, existing studies and books are arguing that there is a high correlation between business plan and corporate performance, however, there are not many domestic and/or foreign studies that analyzed it empirically. In order to find an answer to this problem, this study was approached empirically. First, the components of business plan were selected through an extensive literature review including existing researches and through factor analysis, I classified them into the five factors of product management, product development, management support system building, organizational management and macro planning. Also, I classified corporate performance into quantitative and qualitative performance, and investigated the influences of business plan factors on those performances. As a result, I found belows. First, university students in Korea thought that the business plan components affected the quantitative and qualitative performances of corporate positively. Second, Korean students had high interests in starting up a business and wanted to run a service business but had almost no experience of business planning. Whilst, Foreign students had relatively high interests in starting up a business and experiences of business planning. They wanted starting up in various industry also. Meanwhile, I did't find the gender differences in those aspects. In this study, I empirically investigated the relation between business plan components and corporate performances in the university students' view, not that of company. So I believe that this study can shed lights on the direction of effective starting up education for increasing the success rate of youth starting up a business.

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A study on the speed regulation improvement and water starting time of pumped storaged power plant (양수발전소 속도조정율 향상 및 수력적 부도시간에 관한 연구)

  • Choi, I.K.;Woo, J.H.
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.743-745
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    • 1999
  • In these days, pumped storaged power plants are under operations mainly for load regulation in power system. After we investigated the governor related electrical circuit of a pumped storaged power plant, we measured speed regulation and dead time of both the governor and the hydraulic system according to the change of variables of the governor during generation. After that the measured speed regulation improved much.

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ULTIMATE BEHAVIOR OF PREDATOR-PREY SYSTEM WITH CONSTANT HARVESTING OF THE PREY IMPULSIVELY

  • Dong Lingzhen;Chen Lansun;Sun Lihua;Jia Jianwen
    • Journal of applied mathematics & informatics
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    • v.22 no.1_2
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    • pp.149-158
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    • 2006
  • In this paper, we consider the Lotka- Volterra predator-prey system, in which constant quantity of the prey is harvested in regular pulses. The ultimate behavior of the solutions starting from different regions is mainly studied. Further, some examples are given to illustrate our results.

Assessment of Quality Management Activities in Power Industries (전력산업에서의 품질경영활동의 평가척도)

  • 정영배
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.63
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    • pp.89-99
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    • 2001
  • This paper proposes assessment of quality management activities based on cost of quality. Cost of quality is considered prevention cost, appraisal cost, internal failure cost, external failure cost in this paper. This paper shows quality cost magement system in thermal power site devision according to activity analysis. Cost of quality in power industries provides a valuable method of both proving the need for improvement and giving a starting point for projects.

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The design and performance characteristic of transformerless inverter for the photovoltaic system (변압기 없는 태양광 발전용 인버터의 제작 및 성능 특성)

  • Ahn, Kyo-Sang;Lim, Hee-Chun;Kim, Sin-Sup
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1368-1370
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    • 2003
  • In this paper, the design and performance characteristics of a 3 kW class transformerless photovoltaic inverter was introduced. The field test results of the photovoltaic power inverter showed that the excellence of power quality, the characteristic of starting waveform, the stability and reliability of operation.

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A study of electronic gasoline engine control technique (전자식 가솔린 엔진의 조절 방법에 관한 연구)

  • 성낙원
    • Journal of the korean Society of Automotive Engineers
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    • v.9 no.5
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    • pp.66-76
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    • 1987
  • The control technique for an electronic engine is studied. For this study an IBM-PC and a throttle body fuel injection system are selected. The computer controls fuel injection, spark timing, exhaust gas recirculation and idle speed. Fuel injection is adjusted either by a feed back signal of a zirconia $O_{2}$ sensor or programmed logic for starting, deceleration, warm ing up and idle modes. When a 3-way catalytic converter is used with the electronic engine control system, CO, THC, and NOx were reduced more than 90% simultaneously.

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The Development of Cyber-Education in China: A Review of Experiences and Lessons

  • ZHU, Zhiting;WANG, Wei;LUO, Hongwei
    • Educational Technology International
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    • v.6 no.2
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    • pp.1-9
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    • 2005
  • Starting with analyzing the development of cyber-education in China, this article discusses experiences and lessons acquired through making reflections on the following aspects: technology vs. pedagogy, the degree education vs. non-degree education, resource exclusivism vs. resource inclusivism, mono-service system vs. multi-service system, and educational quality vs. economic profit. Finally, the paper puts forward some suggestions on the future development of cyber-education in China.

An Experimental Study on the Clutch Type Water Pump of Diesel Passenger Vehicle for Reducing Fuel Consumption and CO2 Emission (연비 개선 및 CO2 저감을 위한 승용디젤 차량의 클러치타입 워터펌프 적용에 따른 실험적 연구)

  • Jeong, Soo-Jin;Park, Jung-Kwon;Oh, Chang-Boke;Cho, Yong-Seok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.2
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    • pp.123-134
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    • 2012
  • A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutch-type water pump can force cooling water to supply into an engine by the operation of an electromagnetic clutch equipped as the inner part of pump system. The onset of CWP is decided by temperature of cooling water and engine oil. And, the control logic for an optimal operation of the clutch-type water pump was developed and applied in engine and vehicle tests. In this study, the warm-up time was measured with the conventional water pump and clutch-type water pump in engine tests. And the emission and the fuel consumption were evaluated under NEDC mode in vehicle tests. Also, tests were carried out for the various temperature conditions starting the operation of CWP. From the results of the study, the application of CWP can improve the fuel consumption and $CO_2$ reduction by about 3%.