• Title/Summary/Keyword: power assist

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Pressure Ripple Reduction in Hydrostatic Transmissions by Using a Hydraulic Filter (맥동흡수용 유압필터에 의한 유압전동장치의 압력맥동 감쇠)

  • 김도태
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.3
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    • pp.33-38
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    • 2002
  • This paper deals with pressure ripple attenuation far separated-type Hydrostatic Transmission (HST) consisting ova variable axial piston pump connected in an open loop to a fried displacement axial piston motor. Pressure ripples in HST is major source of vibration which can lead to fatigue failure of components and cause noise. In order to reduce the pressure ripple, an annular tube tripe hydraulic filter is proposed to attenuate pressure ripples with the high frequencies components to achieve better noise reduction in HST. The basic principle of a hydraulic filter is allied to propagation of pressure wave, reflection, absorption in cross section of discontinuity and resonance in the hydraulic pipeline. It is experimentally shown that the hydraulic filter attenuates about 30∼40dB of pressure ripple with high frequencies. These results will assist in modeling and design of noise reduction in hydraulic control systems, and provide a means of designing a quieter HST.

The Practical Strength of Logistics Competition Power for Efficiency of Combined Transport Transaction (복합운송의 물류경쟁력 강화를 위한 실천적 방안)

  • Lee, Hak-Seung
    • International Commerce and Information Review
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    • v.9 no.2
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    • pp.285-303
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    • 2007
  • As the interest about smooth logistics increases lately, the importance of multimodal transport, which performs the key role of logistics emerges, Through there are many issues respecting multimodal transport, the issue of the efficiency of multimodal transport seems to be the most importance. This paper examine as to the problems & systems of the multimodal transport including transportation document and customs clearance for door to door services. I wish our country will use total logistics automation systems for encouraging multimodal transport chance and make a partial amendment of commercial code including the customs clearance regulation. This study will assist in the development of logistic and the enlargement of multimodal transport transaction.

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A Study on Information Strategy Development Using Configuration Management in Large-scale Construction Project (형상관리기법을 활용한 대형 프로젝트 정보화 전략개발)

  • Won, Seo Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.66-67
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    • 2018
  • Large-scale construction projects require various license and technologies for the manufacturing and handling processes. Also, the whole life cycle business process management determines the success of the project. Then, the efficiency of the business conducted by stakeholders and their possessed technology should be enhanced in order to strengthen their competitive power. For this reason, many experts pointed out to focus on the improvement of the life cycle process and efficient management. Since it is very important to keep up-to-date data and utilize it for work during the long-term project to reflect changes in the large-scale project, the most important part of the project management in project is information change management. Therefore, the objective of this study is applying configuration management(CM) technique in order to managing change data generated for planning in early phase. The result of this research will certainly assist the large-scale project managers in the development of information change management system.

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A Study on Design by Customers for Mass Customization Products (대량주문제품의 고객에 의한 설계에 관한 연구)

  • 서광규;김형준;장형걸
    • Journal of the Korea Safety Management & Science
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    • v.2 no.3
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    • pp.47-59
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    • 2000
  • Producing what customers need with near mass production efficiency, or mass customization, has been a major trend in industry. Effective definition of customer requirements is a pre-requisite for realizing mass customization. The new method, called "Design by Customers", is proposed. The proposed method is an approach for companies to communicate to customers about what the company can offer, to find out customer needs, to assist customers in making choices and to negotiate for agreements. In this paper, the design and manufacturing capabilities in making company are represented in a Product Family Architecture. Adaptive Conjoint Analysis is then applied help customers assert their needs, defined variations from base product, visualize their options and assess alternatives. A power supplier of a electronic appliance is shown as an example to demonstrated the suggested method.ed method.

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Heat source modeling of laser arc hybrid welding considering keyhole formation (키홀 형성을 고려한 레이저 아크 하이브리드 용접 열원 모델링)

  • Jo, Yeong-Tae;Na, Seok-Ju
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.97-99
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    • 2005
  • Laser arc hybrid process is actively researched as a new welding method since it has several advantages by the combination of laser beam and electric arc. By the coupling of two different heat sources, laser and arc mutually assist and influence. High power laser can make the deep keyhole and arc plasma can form the large bead shape. In this paper the effect of two different heat sources to weld bead are investigated and as a result of analysis, it is shown that the lower part of keyhole is heated by laser and the upper part of weld pool is dominantly heated by arc.

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A Primary-Side-Assisted Zero-Voltage and Zero-Current Switching Full Bridge DC-DC Converter with Transformer Isolation for Arc Welding (아크 용접에 적합하며 1차 측 보조회로를 사용하는 영전압-영전류 직류-직류 컨버터)

  • Jeon, Seong-Jeub;Cho Gyu-Hyeong
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.10
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    • pp.683-692
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    • 2000
  • A new primary-side-assisted zero-voltage and zero-current switching full bridge DC-DC converter with transformer isolation is proposed. The auxiliary circuit adopted to assist ZCS for the leading leg is composed of only one small transformer and two diodes. It has a simple and robust structure, and load current control capability even in short circuit conditions. Possibility of magnetic saturation due to asymmetricity of circuits or transient phenomena is greatly reduced, which is a very attractive feature in DC/DC converters with transformer isolation. The power rating of the auxiliary transformer is about 10% of that of the main transformer. Operation of a 12.5KW prototype designed for welding application was verified by experiments.

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A Study on System Requirement Structure of EMU System (전동차시스템의 요구사항체계 구축에 관한 연구)

  • Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • 2005.04a
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    • pp.256-258
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    • 2005
  • EMU system is system that o(for target performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

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The Development Plan on Urban Transit System Standard of RAMS based (RAMS기반의 도시철도시스템 표준규격 개발방향 연구)

  • Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1179-1180
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    • 2007
  • Urban transit is system that offer target Performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target Performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

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The Propose to the System Requirement Structure of Rolling Stock System (도시철도 차량시스템 요구사항체계 구축방안에 관한 연구)

  • Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.296-298
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    • 2005
  • Urban transit is system that offer target Performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target Performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

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Measurement of Surface EMG Signal to Control Robot Hand (로봇손 제어를 위한 표면 근전도 신호 측정)

  • Han, Gyu-Beom;Sun, Jee Young;Lim, Kyung-Sun;Kim, Jong-Kook
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.11a
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    • pp.1218-1220
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    • 2012
  • 사람이 근육을 움직여 활동을 하면 근골격근에서 $50{\mu}V{\sim}5mV$의 미세한 전압이 측정된다. 이 신호를 증폭하고 적절한 주파수를 여과시키면 근육의 수축 이완의 정도를 알아내어 움직임이나 동작을 유추해 낼 수 있다. 본 논문에서는 의수 또는 Power-Assist 로봇 등을 사람의 손가락 움직임과 동일하고 더 정밀하게 제어하기 위해 상완 상단부분에서 손가락의 근전도를 측정하는 방식을 연구한다.