• 제목/요약/키워드: overhead

검색결과 3,454건 처리시간 0.029초

Calculation of Ampacity for Bare Overhead Conductors (가공송전선로용 나전선의 허용전류 산정에 대한 검토)

  • Sohn, H.K.;Lee, H.K.;Lee, E.W.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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    • pp.303-305
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    • 2000
  • Many standards have published for calculating the ampacity of bare overhead conductors. Although these standards use the same basic heat balance concept, they use different approaches to calculate ampacity ratings. This paper looks at the different approaches used to calculate individual heat balance terms, at the overall impact of these terms on the ampacity rating. And this paper is proposed to the selection of proper standard and atmospheric conditions for calculating the ampacity of bare overhead conductors.

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An Optimal Control of the Crane System Using a Genetic Algorithm (유전알고리즘을 이용한 크레인 시스템의 최적제어)

  • 최형식
    • Journal of Advanced Marine Engineering and Technology
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    • 제22권4호
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    • pp.498-504
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    • 1998
  • This paper presents an optimal control algorithm for the overhead crane. To control the swing motion and the position tracking of the payload of the overhead crane a state feedback control algorithm is applied. by using a hybrid genetic algorithm the feedback gains of the state feedback is optimized to minimize the cost function composed of position errors and payload swing angle under unknown constant disturbances. Computer simulation is performed to demonstrate the effectiveness of the proposed control algorithm.

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Management of Ulnar Collateral Ligament Injuries in Overhead Athletes

  • Jang, Suk-Hwan
    • Clinics in Shoulder and Elbow
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    • 제22권4호
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    • pp.235-240
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    • 2019
  • Ulnar collateral ligament injuries of the elbow are frequent among overhead athletes. The incidence of ulnar collateral ligament reconstructions (UCLRs) in high-level players has increased dramatically over the past decade, but the optimal technique of UCLR is controversial. Surgeons need to manage the patients' expectations appropriately when considering the mode of treatment. This article reviews current studies on the management of ulnar collateral ligament injuries, particularly in overhead athletes.

Database Program for Managing Management Resources: General Contractor's Perspectives

  • Yong-Woo Kim;Sungwon Shin
    • International conference on construction engineering and project management
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1100-1106
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    • 2009
  • General contractors' overhead costs are increasing relative to direct costs. However, it is difficult to apply the traditional activity-based costing directly to the construction site overhead costing because the resource consumption rate per each activity is varied depending on the attributes of activities. The research develops a methodology of hybrid cost allocation system when resources are assigned to cost objects unlike the traditional activity-based costing. The study also develops a database program and demonstrates how it can be applied to the construction projects using a case study.

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A Study of the Current Collection Characteristics Measurement Methodology for a High-Speed Train (고속열차 전기적 이선 특성 측정 방안 연구)

  • Cho, Hong-Shik;Han, In-Su;Lee, Tae-Hyung;Kim, Seok-Won;Kim, Young-Guk
    • Proceedings of the KSR Conference
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.3052-3058
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    • 2011
  • A high-speed train is the system that the electric power is supplied through the overhead contact line and drives motors. In this case that the de-wiring beteen the overhead contact line and the pantograph of a high-speed train, the occasion that smooth power supply is not accomplished occurs sometimes. If the de-wiring occurs, the arc discharge may damage the overhead contact line or the pantograph, and the falling-off in power quality may cause the damage and malfunctioning of motor block. This paper presents the methodology that the arc discharge by de-wring between overhead line and pantograph is discriminated through measuring the PT and CT in the vehicle, and measures the current collection characteristics for a high speed train.

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Reduction of Residual Vibration for 2 Axes Overhead Crane by Input Shaping (입력성형기법에 의한 2축 천정크레인의 잔류진동 감소)

  • 박운환;이재원;노상현
    • Journal of the Korean Society for Precision Engineering
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    • 제17권4호
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    • pp.181-188
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    • 2000
  • Input shaping is a method fur reducing residual vibration. Vibration is eliminated by convolving an input shaper, which is a sequence of impulses, with the desired system command. It has been applied to robot with a flexible manipulator. But it can be applied to the reduction of residual vibration far overhead crane. In this paper, input shaping shows good performance for anti-sway of overhead crane. In the z-domain, we designed an input shaper and calculated the sensitivity of it. If sensitivity is calculated in the z-domain, the shapes of sensitivity curves are expected easily. Accordingly, it is easy to design an input shaper in the z-domain. We compared the response of a system with shaper to it without that. Also, we compared El shaper to ZV shaper in view of robustness.

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Robust Optimization Design of Overhead Crane with Constraint using the Characteristic Functions (특성함수를 이용한 제한조건이 있는 천장크레인의 강건최적설계)

  • 홍도관;최석창;안찬우
    • Journal of the Korean Society for Precision Engineering
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    • 제21권2호
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    • pp.160-167
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    • 2004
  • The correlation between the object function and the design parameter is shown on this paper by using the characteristic function for the mixed result of the structural analysis, the buckling analysis and the table of orthogonal array according to the original overhead crane's dimensional change. About the above two functions, the effectiveness of design change according to the change of design parameters could be estimated. Also, the overhead crane's weight is reduced up to 10.55 percent maintaining the structural stability according to the thickness of plate.

The Research into Connecting System for Aerial Bundled Cable in Distribution Line (ABC 배전 접속 시스템에 대한 연구)

  • 이용순;최경선;주종민;이철호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.495-498
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    • 2001
  • The distribution line through which electricity is supplied from substation to customer generally varies by underground line and overhead line. In contrast that the underground line is shielded, the overhead lines do not have the shield layer. To overcome this weak point of the overhead lines, the aerial bundled cable(ABC) connection systems have been developed. The basic concept of the ABC connection system is the application of the underground cable system containing complete shield layer to the overhead cable system. The ABC system is the innovative technologies which enable the prevention of electric shocks, reduction of the maintenance charge and damage of the cable. This paper give a full detail of vertical connection system applied within a country.

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A Study on the Surge Analysis considering Surge Arrester and Grounding System in the Combined Distribution System (혼합 배전계통에서 피뢰기적용과 접지시스템 변경을 고려한 서지 해석에 관한 연구)

  • Yun, Chang-Sub;Lee, Jong-Beom;Kim, Beong-Suk
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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    • pp.204-205
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    • 2006
  • This paper describes the protective ability of lightning arrestor in combined distribution system with power cable. To evaluate the protective ability, change of arrestor and grounding location are considered. On the other hand, arrestor developed by Cooper Power Systems for underground power cable system, is considered to evaluate surge protective ability as in underground system, when arrestor occurs failure has overhead line. The result shows that lightning arrestor in combined distribution system with power cable protect effectively when failure at arrestor in overhead line. On the other hand, arrestor developed by Cooper Power Systems for underground power cable system, is considered to evaluate surge protective ability in underground distribution system, when arrestor of overhead line has failure. The result shows that lightning arrestor installed in underground cable can effectively protected cables from surge when arrestor of overhead line has failure. And also even though grounding locations are decreased, it is revealed that protective ability is nearly similar.

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Development and Application of Overhead Transmission Line Design Program Using High Spatial Resolution Satellite Imagery (고해상도 위성영상을 이용한 송전선로 경과지 설계 프로그램 개발 및 활용)

  • Lee, Hee-Seon;Park, Byoung-Won
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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    • pp.27-29
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    • 2005
  • Overhead transmission line design supporting program using high spatial resolution satellite imagery has been developed recently by Korea Power Engineering Company, The developed program, ITSS(Interactive Tower Spotting System) is purposed to improve the application of satellite imagery with the route selection of overhead transmission line. It is composed of spotting the tower position and designing the tower type and height with DEM(Digital Elevation Model) overlaid with satellite Imagery. To review and confirm the function and work efficiency, ITSS was applied to the pilot project of overhead transmission line design.

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