• Title/Summary/Keyword: State equation

Search Result 2,253, Processing Time 0.023 seconds

The Family Satisfaction of Business-Owning Families

  • Rha Jong-Youn;Stafford Kathryn
    • International Journal of Human Ecology
    • /
    • v.2 no.1
    • /
    • pp.77-94
    • /
    • 2001
  • This paper expands empirical research on family satisfaction by introducing the family APGAR scale, developed and validated in the field of nursing, to measure the satisfaction of business-owning families and applying the Stafford et al.(1999) model of sustainable family businesses to the assessment of family satisfaction. More specifically, this study compares the differences in the effects of business- and family-related variables on family satisfaction for the families of lifestyle business owners and earner business owners. The sample was drawn from the 1997 National Family Business Survey. The family satisfaction was greater for the families of lifestyle business owners, but the family variables made a greater contribution to the explanation of variance in the satisfaction of families of earner business owners. The regression equation explained a higher percentage of the variance for the families of earner business owners. Nine family variables were significant in the satisfaction equation for earner business owners, in contrast to seven significant family variables in the equation for lifestyle business owners. Structured families had a significant positive effect on the satisfaction of lifestyle business owners. The family manager's education, putting the family first rather than the business, and the family management score had significant effects on the satisfaction of earner business owners.

  • PDF

ANALOG COMPUTING FOR A NEW NUCLEAR REACTOR DYNAMIC MODEL BASED ON A TIME-DEPENDENT SECOND ORDER FORM OF THE NEUTRON TRANSPORT EQUATION

  • Pirouzmand, Ahmad;Hadad, Kamal;Suh, Kune Y.
    • Nuclear Engineering and Technology
    • /
    • v.43 no.3
    • /
    • pp.243-256
    • /
    • 2011
  • This paper considers the concept of analog computing based on a cellular neural network (CNN) paradigm to simulate nuclear reactor dynamics using a time-dependent second order form of the neutron transport equation. Instead of solving nuclear reactor dynamic equations numerically, which is time-consuming and suffers from such weaknesses as vulnerability to transient phenomena, accumulation of round-off errors and floating-point overflows, use is made of a new method based on a cellular neural network. The state-of-the-art shows the CNN as being an alternative solution to the conventional numerical computation method. Indeed CNN is an analog computing paradigm that performs ultra-fast calculations and provides accurate results. In this study use is made of the CNN model to simulate the space-time response of scalar flux distribution in steady state and transient conditions. The CNN model also is used to simulate step perturbation in the core. The accuracy and capability of the CNN model are examined in 2D Cartesian geometry for two fixed source problems, a mini-BWR assembly, and a TWIGL Seed/Blanket problem. We also use the CNN model concurrently for a typical small PWR assembly to simulate the effect of temperature feedback, poisons, and control rods on the scalar flux distribution.

The Analysis of Electron Energy Distribution Function in $CH_4$ Gas ($CH_4$ 기체의 전자에너지 분포함수 해석)

  • Kim, Sang-Nam;Seong, Nak-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.05c
    • /
    • pp.43-46
    • /
    • 2004
  • This paper describes the information for quantitative simulation of weal이y ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. Using quantitative simulations of weakly ionized plasma, we can analyze gas characteristic. In this paper, the electron transport characteristic in $CH_4$ has been analysed over the E/N range 0.1~300[Td], at the $300[_{\circ}K]$ by the two tenn approximation Boltzmann equation method and Monte Carlo Simulation. Boltzmann equation method has also been used to predict swarm parameter using the same cross sections as input. The behavior of electron has been calculated to give swarm parameter for the electron energy distribution function has been analysed in $CH_4$ at E/N=10, 100 for a case of the equilibrium region in the mean energy. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, Lucas and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

  • PDF

Dynamic Characteristics of Moving Coil Type Linear Oscillatory Actuator (가동코일형 리니어 왕복 액추에이터의 동특성)

  • Jang, S.M.;Jeong, S.S.;Kweon, C.;Park, H.C.;Moon, S.J.;Park, C.I.;Chung, T.Y.
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.49 no.3
    • /
    • pp.180-187
    • /
    • 2000
  • A moving-coil-type linear oscillatory actuator(LOA) consists of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure. The LOA system was represented by the voltage equation of coil and the mechanical equation of motion. This set of equations was manipulated in state-space form. The EMF constant kE of equation parameters in state-space form can be obtained by using the induced voltage in armature coils at open circuit test. kE and other parameters provide the system matrices and transfer function for frequency response and dynamic simulation. Voltage source inverter-fed LOA is examined aiming to compare with results of simulation.

  • PDF

Circumferential steady-state creep test and analysis of Zircaloy-4 fuel cladding

  • Choi, Gyeong-Ha;Shin, Chang-Hwan;Kim, Jae Yong;Kim, Byoung Jae
    • Nuclear Engineering and Technology
    • /
    • v.53 no.7
    • /
    • pp.2312-2322
    • /
    • 2021
  • In recent studies, the creep rate of Zircaloy-4, one of the basic property parameters of the nuclear fuel code, has been commonly used with the axial creep model proposed by Rosinger et al. However, in order to calculate the circumferential deformation of the fuel cladding, there is a limitation that a difference occurs depending on the anisotropic coefficients used in deriving the circumferential creep equation by using the axial creep equation. Therefore, in this study, the existing axial creep law and the derived circumferential creep results were analyzed through a circumferential creep test by the internal pressurization method in the isothermal conditions. The circumferential creep deformation was measured through the optical image analysis method, and the results of the experiment were investigated through constructed IDECA (In-situ DEformation Calculation Algorithm based on creep) code. First, preliminary tests were performed in the isotropic β-phase. Subsequently in the anisotropic α-phase, the correlations obtained from a series of circumferential creep tests were compared with the axial creep equation, and optimized anisotropic coefficients were proposed based on the performed circumferential creep results. Finally, the IDECA prediction results using optimized anisotropic coefficients based on creep tests were validated through tube burst tests in transient conditions.

Effect of Nitrogen Impurity on Process Design of $CO_2$ Marine Geological Storage: Evaluation of Equation of State and Optimization of Binary Parameter (질소 불순물이 이산화탄소 해양 지중저장 공정설계에 미치는 영향 평가: 상태방정식의 비교 분석 및 이성분 매개변수 최적화)

  • Huh, Cheol;Kang, Seong-Gil
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.12 no.3
    • /
    • pp.217-226
    • /
    • 2009
  • Marine geological storage of $CO_2$ is regarded as one of the most promising options to response climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_x$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of the present paper is to compare and analyse the relevant equations of state including PR, PRBM, RKS and SRK equation of state for $CO_2-N_2$ mixture. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $N_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable equation of state and relevant binary parameter in designing the $CO_2-N_2$ mixture marine geological storage process.

  • PDF

Simplified Analysis and Design with Finite Element for Reinforced Concrete Shear Walls Using Limit State Equations (한계상태방정식에 의한 R/C 전단벽의 유한요소 간편 해석과 설계)

  • 박문호;조창근;이승기
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.16 no.1
    • /
    • pp.43-52
    • /
    • 2003
  • The present study is to investigate the ultimate behavior and limit state design of 2-I) R/C structures, with the changing of crack direction, and the yielding of the reinforcing steel bars, and Is to introduce an algorithm for the limit state design and analysis of 2-D R/C structures, directly from the finite element model. For the design of reinforcement in concrete the limit state design equation is incorporated into finite element algorithm to be based on the pointwise elemental ultimate behavior. It is also introduced a simplified nonlinear analysis algorithm for stress-strain relationship of R/C plane stress problem considering the cracking and its rotation in concrete and the yielding of the reinforcing steel bar. The algorithm is incorporated into the nonlinear finite element analysis. The analysis model is compared with the experimental model of R/C shear wall. In a simple design example for a shear wall, the required reinforcement ratios in each finite element is obtained from the limit state design equations.

A Study on the Development of a Lanchester-Type Model Incorporating Firing & Observing States in the Direct Fire Engagement (Firing State와 Observing State를 갖는 Lanchester형 전투모형에 관한 연구)

  • Ham Il-Hwan;Choe Sang-Yeong;Song Mun-Ho
    • Journal of the military operations research society of Korea
    • /
    • v.17 no.2
    • /
    • pp.44-53
    • /
    • 1991
  • This paper is aimed to develop a Lanchester type combat model for the direct-fire engagement. This model incorporates number of combatants, inter-firing time, detection time by movement, detection probability by the signature of fire, where the inter-firing time and the detection time are assumed to follow a negative exponential distribution. The approach to modeling is as follows : in the process of an engagement, a combatant takes one of the states('observing' state or 'firing' state), a combatant is initially in the observing state, if the combatant detects a target, he changes his state from 'observing' to 'firing' and will cause attrition to the opposing forces. Thus this transition mechanism is embodied into the differential equation form with each transition rate. A limited examination of the validity has been conducted by comparison with the Monte-Carlo simulation model 'BAGSIM', and with a traditional Deterministic Lanchester model.

  • PDF

A Diffusion Model for a System Subject to Random Shocks

  • Lee, Eui-Yong;Song, Mun-Sup;Park, Byung-Gu
    • Journal of the Korean Statistical Society
    • /
    • v.24 no.1
    • /
    • pp.141-147
    • /
    • 1995
  • A diffusion model for a system subject to random shocks is introduced. It is assumed that the state of system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. It is also assumed that the shocks coming to the system according to a Poisson process decrease the state of the system by a random amount. It is further assumed that a repairman arrives according to another Poisson process and repairs or replaces the system i the system, when he arrives, is in state zero. A forward differential equation is obtained for the distribution function of X(t), the state of the systme at time t, some boundary conditions are discussed, and several interesting characteristics are derived, such as the first passage time to state zero, F(0,t), the probability of the system being in state zero at time t, and F(0), the limit of F(0,t) as t tends to infinity.

  • PDF

Parameter Space Restriction in State-Space Model (상태 공간 모형에서의 모수 공간 제약)

  • Jeon, Deok-Bin;Kim, Dong-Su;Park, Seong-Ho
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2006.11a
    • /
    • pp.169-172
    • /
    • 2006
  • Most studies using state-space models have been conducted under the assumption of independently distributed noises in measurement and state equation without adequate verification of the assumption. To avoid the improper use of state-space model, testing the assumption prior to the parameter estimation of state-space model is very important. The purpose of this paper is to investigate the general relationship between parameters of state-space models and those of ARIMA processes. Under the assumption, we derive restricted parameter spaces of ARIMA(p,0,p-1) models with mutually different AR roots where $p\;{\le}\;5$. In addition, the results of ARIMA(p,0,p-1) case can be expanded to more general ARIMA models, such as ARIMA(p-1,0,p-1), ARIMA(p-1,1,p-1), ARIMA(p,0,p-2) and ARIMA(p-1,1,p-2).

  • PDF