• Title/Summary/Keyword: Break-down

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CONVERGENCE AND BREAKDOWN STUDY OF KRYLOV METHODS FOR NONSYMMETRIC LINEAR SYSTEMS

  • Yun, Jae-Heon
    • Communications of the Korean Mathematical Society
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    • v.10 no.4
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    • pp.981-995
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    • 1995
  • This paper first establishes some conditions for preconditioner under which PGCR does not break down. Next, VPGCR algorithm whose preconditioners can be easily obtained is introduced and then its breakdown and convergence properties are discussed. Lastly, implementation details of VPGCR are described and then numerical results of VPGCR with a certain criterion guaranteeing no breakdown are compared with those of restarted GMRES.

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Basic Study of Glimm's Algorithm for Green Water Simulation

  • Han Ju-Chull;Lee Seung-Keun;Lee Gyoung-Woo
    • Journal of Navigation and Port Research
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    • v.28 no.9
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    • pp.809-813
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    • 2004
  • Experiments revealed that green water phenomena resemble dam-break, in which flow over deck edge forms a vertical wall of water and suddenly falls down into deck. In this paper the dam breaking problems were formulated using Glimm's algorithm, so-rolled, Random Choice method and, several validations were presented.

Evaluation of CFS Tensile Strength Reduction Factor for Bending Analysis of RC Beams Strengthened with Carbon Fiber Sheets (탄소섬유시트 보강보 휨해석에 영향을 미치는 섬유시트 인장강도 감소계수 평가)

  • 윤진섭;이우철;정진환;김성도;조백순
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.359-362
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    • 2003
  • Carbon fiber sheet is attractive due to its good tensile strength, resistance to corrosion, and low weight. The strengthening of concrete structures with externally bonded carbon fiber sheets is increasingly being used for repair and rehabilitation of existing structures. However CFS strengthened beams break down under the service loads. As rupture strain is not reached ultimate value, reduction of the tensile strength is recommended. This study evaluate CFS tensile strength reduction factor which is required to analyze bending moment.

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Air-Water Two-phase Flow Patterns and Pressure Distributions in a Screw-type Centrifugal Pump

  • Kim, You-Taek
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.8
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    • pp.1203-1210
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    • 2004
  • It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.

Implementation of Dynamic Resistance Database for Weld Quality Improvement of Spot Welder (스폿용접기의 용접품질 향상을 위한 동저항 데이터 베이스 구축)

  • 조승진;김재문;원충연;최규하;김규식;목형수
    • Proceedings of the KIPE Conference
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    • 1998.07a
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    • pp.143-148
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    • 1998
  • A dynamic electrical parameter monitoring device was designed to simultaneously record the instantaneous value of voltage, current, power, and resistance during spot welding. The data obtained using this technique have been analyzed in term of the relationships of these parameters to the phenomena occuring during the formation(surface break-down, nugget formation and mechanical collapse) of spot weld. Finally, a database implementation is undertaken to develop techniques for improving weld quality of the resistance spot welder.

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AC Breakdown Voltage Characteristics in $SF_6$ Gas with Spacer Under Mon-uniform Field ($SF_6$ 가스중 스페이서가 존재하는 불평등전계하에서의 교류파괴전압 특성)

  • Kim, Jung-Dal;Song, Hee-Suck;Song, Won-Pyo
    • Proceedings of the KIEE Conference
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    • 1990.07a
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    • pp.293-296
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    • 1990
  • In this work, we reviewed AC break-down voltage characteristics in $SF_6$ Gas with spacer under nonuniform field, using the electrode construction of model spacer and simple protrusion. We cleared that breakdown voltage and surface flashover strongly depend on the position of spacer's insert.

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A Review on Recent Direction of Research and Safety of Sweetener (감미료의 최신 연구동향과 안전)

  • 하성윤
    • Proceedings of the Korean Society of Food Hygiene and Safety Conference
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    • 1994.06a
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    • pp.29-39
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    • 1994
  • A review on sweetener has been conducted. Enzymes are utilized preferentially to break-down or synthesize stevioside, MGGR and oligo-saccharides. these result in change or modification of the functions of sweetener. Originally, the sweetener was used to obtain energy, add sweet taste and for rheological properties. Recently, the physiological functions of the sweetener have been studied considerably. As the oligo-sacchride is found to function as substance of physiological activities, more researh will be carried out using enzyme to discover new functions of sweetener.

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Buffer System Design in the Flexible Manufacturing System Environments (유연생산(柔軟生産)시스템에서의 버퍼시스템 설계(設計))

  • Gang, Hui-Jeong;Kim, Hwan-Seong;Jo, Nam-Ho
    • Journal of Korean Society for Quality Management
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    • v.20 no.2
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    • pp.118-128
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    • 1992
  • The determination of appropriate buffer capacity is an important issue in the design of the advanced manufacturing systems and closely related to the system efficiency and flexibility. Work-in-process is usually not desirable. However, in reality, maintaining some capacity of buffer storage is inevitable in compensation for the machine blocking and break down. The objective of this paper is to present analytical methods and tools for the buffer capacity planning in the Flexible Manufacturing System Environments. The effects when machine blocking is critical factor are also discussed.

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Evaluation of failure and Design criteria for the pressrue vessel (압력용기의 설계기준 및 손상 평가)

  • Oh Hwansup;Jung Hyojin;Pak Sangpil;Son Duik
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2005.05a
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    • pp.228-233
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    • 2005
  • The damage of the pressure courage by degradation can become the reason of unexpected break down or failure accident and it is very important because safety accident, the production loss, environmental pollution, social problems are occur. Consequently The result to investigat of failure accident for domestic pressure vessel, the factor of degradation is SCC, Sorrosion, Cavity, Crack.

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