• 제목/요약/키워드: Economy efficiency

검색결과 831건 처리시간 0.03초

플라이휘일 하이브리드 차량의 다경로 동력전달장치 연구 (A Study on Multi Pass Transmission System for a Flywheel Hybrid Vehicle)

  • 송한림;김현수
    • 한국자동차공학회논문집
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    • 제5권3호
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    • pp.106-116
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    • 1997
  • In this paper, using MATLAB SIMULINK, a generalized design methodology was suggested for multi pass transmission(MPT) by classifying the vehicle power train as prime mover, MPT and vehicle dynamics. This approach enables a designer to investigate the influence of each transmission component by simple combination of system components without changes of overall program. Using the design methodology, a MPT consisting of CVT, 2, clutches and reduction gears was designed for a braking energy regenerative flywheel hybrid vehicle. The CVT is essential in order to connect the engine and flywheel speed with the vehicle speed. For the purpose of smooth clutch operation, control algorithm was suggested by introducing dead zone for the clutch engagement. Using the SIMULINK model, performance of the flywheel hybrid vehicle with MPT was investigated. It was observed from the simulation results that the MPT vehicle showed better fuel economy, 47% than that of AT vehicle, 27% than that of CVT vehicle for ECE-15 driving cycle. Especially destinct fuel efficiency improvement was obtained for city driving cycle requiring more frequent stop and start.

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교회법을 이용한 해양 등부표 위치결정 (Position of Light Buoy Using Method of Intersection)

  • 이종출;김차겸;장호식;박종민;김세준
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 추계학술발표회 논문집
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    • pp.491-495
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    • 2004
  • Harbor and bay is essential social overhead capital to our country economy national security. This harbor and bay is ever-present danger of marine accident by massed sea traffic discharge. A nautical mark in sea maintains safety of sea traffic and establishes in sea for increase of efficiency of ship service to prevent this sea accident. In this study, position of light buoy that establish for safety of harbor and bay that decided adjacent district along the coast base point by utilization method of intersection and evaluated and compares with DGPS measurement techniques.

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4기통 4사이클 터보과급 가솔린 기관의 성능 및 배기조성 예측에 관한 연구 (제1보) (Study on the Prediction of Performance and Emission in a 4-Cylinder 4-Stroke Cycle Turbocharged Gasoline Engine (First Paper))

  • 유병철;이병해;윤건식
    • 오토저널
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    • 제10권6호
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    • pp.25-38
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    • 1988
  • As a mean of increasing engine power, great attention has been concentrated on the turbo-charging owing to better fuel economy, smaller engine size and lower emission. The performance in turbocharged engine depends not only on the efficiency of the engine and the turbocharger used, but also on the total characteristics of the system by the matching turbocharger to the engine. The matching of the turbocharger to the engine has been usually accomplished by the empirical techniques with a great deal of laborious work. It would be better to predict the performance and emission in the turbocharged engine using the effective simulation model. In this study, computer simulation program has been developed to predict the transient variation of properties of gas in the cylinder, intake and exhaust pipes, the engine performances and emissions.

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Development of a Musculoskeletal Load Measuring Device for Construction Workers Based on Accelerometers and Gyro Sensors

  • Kim, Kyoon-Tai
    • 한국건축시공학회지
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    • 제11권6호
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    • pp.618-626
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    • 2011
  • The characteristics of construction work cause excessive strain on specific body parts of the construction craft workers. However, there are few tools to mane an accurate measurement of the load on the musculoskeletal system, and the musculoskeletal disorders (MSDs) experienced by the workers have not been properly understood. So, there is an urgent need for development of a tool to measure the load on the musculoskeletal system. Therefore, this research aims to develop a musculoskeletal load measuring device for construction workers. In order to eliminate the noise and errors, an accelerometer, gyro sensors and the Kalman Filter are used in the device developed in this research.

선물증여의 개념에 관한 이론적 고찰 (A Conceptual Framework for the Gift Giving in Consumer Behavior Research)

  • 이상협
    • 대한가정학회지
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    • 제30권3호
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    • pp.257-270
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    • 1992
  • Gift giving is usually conducted at festive days, Christmas or Parent's day. When consumers purchase gifts, they have some troubles about efficiency and economy of gifts. The issues about gifts purchase also involve the conceptualizing and establishing evaluative measure of gifts. In order to solve some problems concerning to gift giving, it is necessary to define the concept of gift giving above all. Therefore, the purpose of this article is to establish the concept of gift giving in heop of the study of anthropology and sociology about the beginning of gifts. And it attempts to review on gift giving in the field of consumer behavior. So, first this article proposes that the core concept of gift giving is a reciprocity. It means the obligatory system performed among small groups or individuals. Second, in order to analize the gift giving process, it needs to involve important variables-gift occasion and motivation of gift giving, and intimacy relationship.

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고대 출토 철제 유물의 환경 변화에 따른 고찰 (The Study of Environment Change for Iron Antiquities after Excavation)

  • 문환석;김병근;위광철;황진주
    • 보존과학연구
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    • 통권14호
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    • pp.35-44
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    • 1993
  • The way of prevention for the continuous corrosion progress in iron antiquities after excavation and conservation treatment have been studied. The corrosion occuring have been found the oxidation of ferrous ions in the presence of chloride. The consideration to control the activity of chloride is important of controling relative humidity for the stable environment of the storage. One of the method that keeps archeological iron antiquities recommend the storage of special vinyl film(poly-vinyl alcohol film) with silica gel to control the relative humidity. Although this method is not permanent, it's very well efficiency of economy and convenience at present.

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중소기업 조세지원제도의 효율화에 관한 연구 (A Study on the Efficiency of the Tax Support Systems for Small Business)

  • 송동섭;김재준
    • 산업경영시스템학회지
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    • 제21권47호
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    • pp.149-168
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    • 1998
  • The aim of this research is to devise and grope for the solution to the problems and betterment of both the present tax system facing the country and the present conditions of small businesses in order to develop small businesses and strengthen the competitiveness of them; as a result, this paper lays a strong emphasis on the point that small businesses must take a more tax reduction than big businesses in view of influence on national economy. However, it is important that small businesses try to exert itself to provide competitiveness in the market. It is also necessary that although the administration helps frame the policy of small businesses toward reduction in tax, it must set up strong measures to help the tax reduction of them centering around competitive businesses.

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시스템다이내믹스 기법을 이용한 공공정책 성과감사 모형개발에 관한 연구 (A Study on the Development of Performance Audit Model Using the System Dynamics)

  • 최남희
    • 한국시스템다이내믹스연구
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    • 제12권3호
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    • pp.25-46
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    • 2011
  • Recently, performance auditing system of governmen is carried out as most promising framework of government audit. Performance audit by the Board of Audit and Inspection of Korea involves assessing the causes and effects of government policies, programs, and Institutions with the criteria of economy, efficiency, effectiveness. Performance auditing will contribute to strengthening the values of objective assessments of whether public resources are responsibly and effectively managed to achieve intended results. Nevertheless, there seems to be a problems appears in implementation of audit. That is the problems of tendency return to legitimacy audit which is result from the lack of strong approach and methodology. So, this study purpose to developing stronger audit concepts and methods that add to the process and framework of traditional performance auditing system. First, this study evaluates the limitation of current performance auditing system with the perspective of systems thinking. Second, this study analyzes the process and method of current system and develop the conceptual model of the Dynamics Audit System using the system dynamics methodology, which focused on the appropriate auditing process and framework.

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Online Channel Strategies of Hybrid Firms and Social Cost

  • Cho, Su-Mi;Lee, Sang-Ho
    • Management Science and Financial Engineering
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    • 제13권1호
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    • pp.55-72
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    • 2007
  • We consider the product differentiation model of online channel competition and examine the strategies of hybrid firms in terms of efficiency. After measuring the social cost of online business strategies, we show that (i) online channel of hybrid firm under blockaded entry may increase the social cost if the firms' delivery cost is sufficiently smaller than the consumer's transportation cost, and (ii) online competition under free entry may increase the social cost if the firms' delivery cost is sufficiently larger than the consumer's transportation cost. Finally, we discuss the strategic incentive of hybrid firms to reduce delivery cost and investigate the effect of the Internet maturity on the social cost.

국가경쟁력 강화를 위한 SOC 투자 전략 (SOC Investment Promotion Strategy for Strengthening Global Competitiveness)

  • 이선
    • 기술사
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    • 제45권5호
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    • pp.26-35
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    • 2012
  • Korea is now the 12th largest economy in the world, surpassing its annual trade in the amount of $1 trillion, and it has joined the socalled 20-50 Club, becoming one of the seven countries in the world with capita income of more than $20,000 with population of 50 million. However it ranked 24th of the Global competitiveness index evaluated by World Economic Forum based on the basic requirements including infrastructures, efficiency enhances, innovation and sophistication factors, etc. The extensive and efficient SOC infrastructures are critical for ensuring the global competitiveness of each country. Effective modes of SOC facilities including quality roads, railroads, ports, air transport, etc will be able to reduce the annual traffic congestion cost as well as macro economic logistics costs in Korea, thereby the global competitiveness can be strengthened in the global market.

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