• Title/Summary/Keyword: Branch flow

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A Study on Identification of Open Area of Pump for Hydraulic Excavator (유압 굴삭기용 펌프의 개구면적 규명에 관한 연구)

  • Lim T.H.;Oh B.S.;Lee H.S.;Yang S.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.101-102
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    • 2006
  • The purpose of this paper is pulsation-analysis of the swash plate type axial piston pump for excavator and the method of side branch hose application, which is used normally in construction equipments. In this paper, draw the mathematical modeling for pressure pulsation mechanism of the swash plate type axial piston pump for excavator, expression the flow pulsation in the pipelines by transfer matrix method, programmed simulation for pulsation by AMEsim software, and the reliability of that was verified by the comparison with the experimental results.

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Safety Analysis on the Tritium Release Accidents

  • Yang, Hee joong
    • Journal of Korean Society for Quality Management
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    • v.19 no.2
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    • pp.96-107
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    • 1991
  • At the design stage of a plant, the plausible causes and pathways of release of hazardous materials are not clearly known. Thus there exist large amount of uncertainties on the consequences resulting from the operation of a fusion plant. In order to better handle such uncertain circumstances, we utilize the Probabilistic Risk Assessment(PRA) for the safety analyses on fusion power plant. In this paper, we concentrate on the tritium release accident. We develop a simple model that describes the process and flow of tritium, by which we figure out the locations of tritium inventory and their vulnerability. We construct event tree models that lead to various levels of tritium release from abnormal initiating events. Branch parameters on the event tree are assessed from the fault tree analysis. Based on the event tree models we construct influence diagram models which are more useful for the parameter updating and analysis. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of consequences resulting from the operating a fusion power plant. We also discuss the way to utilize the results of testing on sub-systems to reduce the uncertain ties on over all system.

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Incidental Detection of a Pseudoaneurysm at an Amputation Stump in a Tc-99m HMPAO labeled Leukocyte Scan (Tc-99m HMPAO 표지 백혈구스캔상 대퇴 절주에서 우연히 발견된 가성동맥류)

  • Sohn, Myung-Hee;Jeong, Hwan-Jeong;Lim, Seok-Tae
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.4
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    • pp.337-338
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    • 2007
  • A 20-year-old man underwent a Tc-99m HMPAO labeled leukocyte scan for the evaluation of an infection at the stump of an AK amputation, which was conducted due to an open communicated fracture of the left lower leg. Blood-flow and blood-pool images demonstrated a pseudoaneurysm with a focus of intense activity medial to the stump, and centered within a large photopenic defect by surrounding hematoma. Delayed image obtained at 3 hours post-injection showed persistent intense and slight increased activity, Contrast angiography confirmed the presence of a pseudoaneurysm arising from a branch of the left superficial femoral artery.

Eigenvalue Branches and Flutter Modes of Pipes with a Tip Mass Conveying Fluid (끝단질량을 갖는 송수관의 고유치 분기와 플러터 모드)

  • 류봉조;류시웅;빈산길언;임경빈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.665-669
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    • 2003
  • The paper deals with the relationship between the eigenvalue branches and the corresponding flutter modes of cantilevered pipes with a tip mass conveying fluid. Governing equations of motion are derived by extended Hamilton's principle, and the numerical scheme using finite element method is applied to obtain the discretized equations. The order of branches and unstable modes associated with flutter are defined in the stability maps of mass ratios of the pipe and the critical flow velocity. As a result, the relationship between the flutter related to the eigenvalue branches and the flutter modes are investigated thoroughly.

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Mismatching Problem between Generic Pole-assignabilities by Static Output Feedback and Dynamic Output Feedback in Linear Systems

  • Kim Su-Wood
    • International Journal of Control, Automation, and Systems
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    • v.3 no.1
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    • pp.56-69
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    • 2005
  • In this paper, it is clearly shown that the two well-known necessary and sufficient conditions mp n as generic static output feedback pole-assignment and mp + d(m+p) n+d as generic minimum d-th order dynamic output feedback pole-assignment on complex field, unbelievably, do not match up each other in strictly proper linear systems. For the analysis, a diagram analysis is newly created (which is defined by the analysis of 'convoluted rectangular/dot diagrams' constructed via node-branch conversion of the signal flow graphs of output feedback gain loops). Under this diagram analysis, it is proved that the minimum d-th order dynamic output feedback compensator for pole-assignment in m-input, p-output, n-th order systems is quantitatively decomposed into static output feedback compensator and its associated d number of arbitrary 1st order dynamic elements in augmented (m+d)-input, (p+d)-output, (n+d)-th order systems. Total configuration of the mismatched data is presented in a Table.

Active Front End Inverter with Quasi - resonance

  • Siebel, Henrik;Pacas, J.M.
    • Journal of Power Electronics
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    • v.3 no.1
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    • pp.17-23
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    • 2003
  • A new three-phase soft-switching active front-end inverter is presented. The topology consists of a quasi-resonant PWM boost converter with an additional resonant branch, which provides low loss at high frequency operation. This leads to a high conversion efficiency and a remarkable reduction in the siBe of the input inductor. To synchronise the PWM pattern with the resonance cycle, a modified space vector modulation with asymmetrical PWM pattern is used. A high power factor can be achieved for both power flow directions. Due to a new control strategy the converter features a low content of harmonics in the line currents even for distorted line voltages.

Power System Oscillations Damping Using UPFC Based on an Improved PSO and Genetic Algorithm

  • Babaei, Ebrahim;Bolhasan, Amin Mokari;Sadeghi, Meisam;Khani, Saeid
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.1
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    • pp.135-142
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    • 2012
  • In this paper, optimal selection of the unified power flow controller (UPFC) damping controller parameters in order to improve the power system dynamic response and its stability based on two modified intelligent algorithms have been proposed. These algorithms are based on a modified intelligent particle swarm optimization (PSO) and continuous genetic algorithm (GA). After extraction of UPFC dynamic model, intelligent PSO and genetic algorithms are used to select the effective feedback signal of the damping controller; then, to compare the performance of the proposed UPFC controller in damping the critical modes of a single-machine infinite-bus (SMIB) power system, the simulation results are presented. The comparison shows the good performance of both presented PSO and genetic algorithms in an optimal selection of UPFC damping controller parameters and damping oscillations.

A Study of Synthesis Algorithm for Component Mapping (콤포넌트 맵핑을 위한 합성 알고리즘에 관한 연구)

  • 김재진;이사원
    • Journal of the Korea Society of Computer and Information
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    • v.3 no.4
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    • pp.44-48
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    • 1998
  • In this paper proposed Component Synthesis Algorithm(CSA) for mapping described HDL to RT component of given library. CSA transform I/O variables of HDL and relation of operators to control/data flow graph(CDFG) that consists of graph, reduce the size of graph, compute the cost, the bound, and the method that use compatibility graph(CG), and then mapping to component. Component synthesis used branch-and-bound algorithm. The result that synthesis using CSA algorithm was proved that this result and the cost of the manual were indentified.

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Discussion of the edge flame structure at the near flammability limits (가연한계 영역에서의 에지 화염 구조 및 고찰)

  • Lee, Min Jung;Jung, Yongjin;Kim, Nam Il
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.245-246
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    • 2015
  • In this study, the structure of a edge flame near the flammability limits was explored through several paths approaching the combustion limits of a non-premixed flame: i.e., increase of fuel dilution ratio (FDR), reduction of mean flow velocity and variation of gravity effect. As a result, a unique interesting flame structure was discovered; i.e., a diffusion flame branch was enclosed by two asymmetric premixed flame branches. These structures have been compared for various fuels. Conclusively, each fuel has different flame structure and the meaning of this structure was discussed concerned about our understanding of laminar flame structures.

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Development of the Topology Processor using Matrix Structure (Matrix Structure를 이용한 토폴로지 프로세서 개발)

  • Cho, Y.S.;Yun, S.Y.;Lee, W.H.;Lee, J.;Heo, S.I.;Kim, S.G.;Lee, H.S.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.646-647
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    • 2007
  • The topology processor uses the status of circuit breakers as input. It operates on the bus section connectivity data, which is stored in the data base, to determine the bus/branch topology of the network. This output of the topology processor forms part of the input to the state estimation or dispatcher power flow. This paper describes the development of the topology processor using matrix structure.

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