• Title/Summary/Keyword: steady-state

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Minimization of Inspection Cost in an Inspection System Considering the Effect of Lot Formation on AOQ

  • Yang, Moon-Hee
    • Management Science and Financial Engineering
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    • v.16 no.1
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    • pp.119-135
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    • 2010
  • In this paper, we readdress the optimization problem for minimizing the inspection cost in a back-light unit inspection system, which forms a network including a K-stage inspection system, a source inspection shop, and a re-inspection shop. In order to formulate our objective function when the system is in a steady state, assuming that the number of nonconforming items in a lot follows a binomial distribution when a lot is formed for inspection, we make a steady-state network flow analysis between shops, and derive the steady-state amount of flows between nodes and the steady-state fraction defectives by solving a nonlinear balance equation. Finally we provide some fundamental properties and an enumeration method for determining an optimal value of K which minimizes our objective function. In addition, we compare our results numerically with previous ones.

The steady-state vibration analysis of piping system by applying displacement assumption method (변위 가정법을 이용한 배관 시스템의 정상 상태 진동 해석)

  • Lee, Seong-Hyeon;Jeong, Weui-Bong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.827-830
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    • 2011
  • The equation of motion for the piping system conveying harmonically pulsating fluid is presented. When pulsating fluid flows, the properties of this system like mass, stiffness and damp is changing according to fluid fluctuation. To solve the steady-state time response of this system, numerical integration method of differential equation was usually used. But this method has some problem such time consuming method and difficulty of converging. Therefore this research suggests reliable and efficient numerical method to solve steady-state time response of piping system by using displacement assumption method.

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A Study on the Steady-State Cornering of a Vehicle Considering Roll Motion (롤 운동을 고려한 차량의 정상상태 선회주행에 관한 연구)

  • 이장무;윤중락;강주석;배상우;탁태오
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.6
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    • pp.89-102
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    • 1997
  • In this study, the steady state cornering behavior of a vehicle is investigated by using a numerical model that has parameters associated with roll motion. The nonlinear characteristics of tire cornering forces and aligning torques are presented in analytical forms using the magic formula. The sets of nonlinear algebraic equations that govern the cornering motion are solved by the Newton-Raphson iteration method. The vehicle design parameters are measured by SPMD(Suspension Parameter Measuring Device), and its results are verified by carrying out a skid pad test. The design parameters that are most affecting the steady state cornering behavior are classified into four factors, and the contributions of the factors to understeer gradient are then calculated.

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Step Response of RF Plasma in Carbon Tetrafluoride($CF_4$)

  • So, Soon-Youl;Akinori Oda;Hirotake Sugawara;Yosuke Sakai
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.930-933
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    • 2000
  • To understand the behavior of electron, ions and radicals on radio-frequency non-equilibrium plasma, it is necessary to know the basic information about its fundamental properties and reactions. Especially, the transient response of radio-frequency plasma has an important means of controlling selective etch rates and investigating the stability of a plasma chemical process. In this paper, we present the results of periodic steady-state behavior and transient behavior carbon Tetrafluoride(CF$_4$) discharge at 0.2 Torr in a 2 cm gap parallel-plate. After the number densities of charged particles became steady-state, the applied voltage was increased or decreased in an instant and the transient behavior of charged particles and radicals was investigated from one steady-state to the next steady state.

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Steady State Analysis of Magnetic Head Slider at Ultra Low Clearance (마그네틱 헤드 슬라이더의 極小 空氣膜에 대한 定常狀態 解析)

  • 장인배;한동철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.4
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    • pp.764-770
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    • 1989
  • This paper analyze the steady state performance of a self-acting air lubricated slider bearing in hard disk/head system. Modified Reynolds' equation is derived from the steady state compressible Navier-Stokes equation, under slip-flow conditions. Finite difference technique and numerical procedure are described by using Newton-Raphson iteration method to slove the non-linear equations. These techniques are applied to conventional slider bearings and the effects of molecular mean free path(MMFP) for a recording surface of hard disk are shown. The calculation procedure developed here, wide applicabilities in practical head design procedures, and converges rapidly.

Study on Steady State Analysis of High Power Three-Phase Transformer using Time-Stepping Finite Element Method (시간차분 유한요소법을 이용한 대용량 삼상 변압기의 정상상태 해석에 관한 연구)

  • Yoon, Hee-Sung;Seo, Min-Kyu;Koh, Chang-Seop
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.8
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    • pp.1123-1129
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    • 2012
  • This paper presents the fast steady state analysis using time-stepping finite element method for a high power three-phase transformer. The high power transformer spends huge computational cost of the time-stepping finite element method. It is because that the high power transformer requires a lot of time to reach steady state by its large inductance component. In order to reduce computational cost, in this paper, the adaptive time-step control algorithm combined with the embedded 2nd 4th singly diagonally implicit Runge-Kutta method and the analysis strategy using variation of the winding resistance are studied, and their numerical results are compared with those from the typical time-stepping finite element method.

Analysis of (K, r) Incomplete Inspection Policy for Minimizing Inspection Cost subject to a Target AOQ (출하 품질목표 조건하에 검사비용을 최소화하는(K, r) 부분검사정책의 분석)

  • Yang, Moon-Hee
    • IE interfaces
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    • v.24 no.1
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    • pp.87-96
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    • 2011
  • In this paper, we address an optimization problem for minimizing the inspection and rework cost in an inspection-rework system, which forms a network of nodes including a K-stage inspection system, storage areas for items, a source inspection shop, and a re-inspection shop. We assume that (n, 0) acceptance sampling is performed in the source inspection shop and that only 100(1-r)% of items of rejected lots are re-inspected in the re-inspection shop. Since all the nodes are interrelated, in order to formulate our steady-state objective function, we make a steady-state network flow analysis between nodes, and derive both the steady-state amount of flows between nodes and the steady-state fraction defectives by solving a nonlinear balance equation. Finally we provide some fundamental properties and an enumeration procedure for determining the optimal values of (K, r) which both minimizes our objective function and attains a given target average outgoing quality.

The Time Correlation Functions of Concentration Fluctuations in the Lotka Model near the Oscillatory Marginal Steady State

  • Kim Cheol-Ju;Lee Dong Jae;Ko Seuk Beum;Shin Kook Joe
    • Bulletin of the Korean Chemical Society
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    • v.9 no.1
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    • pp.36-40
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    • 1988
  • The time correlation functions of concentration fluctuations due to the random forces near the steady state are evaluated for a general two-component nonlinear chemical system by solving the corresponding two dimensional Fokker-Planck equation. The approximate method of solving the Fokker-Planck equation is based on the eigenfunction expansion and the corresponding eigenvalues for both the linear and nonlinear Fokker-Planck operators are obtained near the steady state. The general results are applied to the Lotka model near the oscillatory marginal steady state and the comparison is made between linear and nonlinear cases.

Effects of Light Intensity on the Steady-State Fluorescence Quenching Kinetics

  • Mino Yang;Sangyoub Lee;Kook Joe Shin;Kwang Yul Choo;Duckhwan Lee
    • Bulletin of the Korean Chemical Society
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    • v.12 no.4
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    • pp.414-423
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    • 1991
  • Effects of light intensity on the steady-state fluorescence quenching kinetics are examined for general cases where the bimolecular quenching can occur via long-range energy transfer processes and the potential of mean force between the energy donor and acceptor molecules is not negligible. Approximate analytic expressions are derived for the steady-state quenching rate constant and for the ratio of the steady-state intensity of unquenched to quenched fluorescence. The analytic results are compared with the exact results obtained from numerical analysis and the results of conventional theories.

EXISTENCE OF NON-CONSTANT POSITIVE SOLUTION OF A DIFFUSIVE MODIFIED LESLIE-GOWER PREY-PREDATOR SYSTEM WITH PREY INFECTION AND BEDDINGTON DEANGELIS FUNCTIONAL RESPONSE

  • MELESE, DAWIT
    • Journal of applied mathematics & informatics
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    • v.40 no.3_4
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    • pp.393-407
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    • 2022
  • In this paper, a diffusive predator-prey system with Beddington DeAngelis functional response and the modified Leslie-Gower type predator dynamics when a prey population is infected is considered. The predator is assumed to predate both the susceptible prey and infected prey following the Beddington-DeAngelis functional response and Holling type II functional response, respectively. The predator follows the modified Leslie-Gower predator dynamics. Both the prey, susceptible and infected, and predator are assumed to be distributed in-homogeneous in space. A reaction-diffusion equation with Neumann boundary conditions is considered to capture the dynamics of the prey and predator population. The global attractor and persistence properties of the system are studied. The priori estimates of the non-constant positive steady state of the system are obtained. The existence of non-constant positive steady state of the system is investigated by the use of Leray-Schauder Theorem. The existence of non-constant positive steady state of the system, with large diffusivity, guarantees for the occurrence of interesting Turing patterns.