• Title/Summary/Keyword: power-law model

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The Role of State Courts Aiding Arbitration (중재에 있어서 법원의 역할)

  • Park, Eun-Ok
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.30
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    • pp.91-120
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    • 2006
  • An Arbitration agreement is one kind of contracts between two or more contracting parties; any possible disputes that arise concerning a contract will be settled by arbitration. Contracting parties who have made a valid arbitration agreement will submit a dispute for settlement to private persons(arbitrators) instead of to a court. Arbitration may depend upon the agreement of the private parties, but it is also a system which has been built on the law and which relies upon that law in order to make it effective both nationally and internationally. That is to say, arbitration is wholly dependent on the underlying support of the court. The complementarity of the courts and of the arbitrators is a well-established fact; they seek for the common purpose, the efficacy of international commercial arbitration. Most states' laws contain the provisions which have been set for the supportive role of the courts relating to arbitration; (1) the enforcement of the arbitration agreement(rulings on validity of the arbitration agreement), and the establishment of the tribunal at the beginning of the arbitration, (2) challenge of arbitrators, interim measures, and intervention during evidence in the middle of the arbitral proceedings, (3) filing of the award, challenge of the arbitral award, and recognition and enforcement of the arbitral award at the end of the arbitration. Most international instruments and national laws concerning arbitration believe that authoritative courts should play their power not to control and supervise arbitration but to support and develop the merits of arbitration at most. 1985 UNCITRAL Model Law also expressly limit the scope of court's intervention to assist arbitration, not to control it.

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Finite Element Analysis of Rubber Extrusion Forming Process (고무 압출성형 공정에 대한 유한요소 해석)

  • Ha, Yeon-Sik;Cho, Jin-Rae;Kim, Tae-Ho;Kim, Jun-Hyoung
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.762-767
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    • 2007
  • As a macromolecule material, melted rubber flow shows characteristics of shear thinning fluid. The dynamic viscosity of this rubber fluid is influenced by temperature and shear strain rate. In this study, the numerical simulation of rubber extrusion forming process has been performed using commercial CFD code, Polyflow. Power-law model considering the effect of shear rate is used for the computer simulation of this non-Newyonian flow. Also Non-isothermal behavior is considered as Arrhenius-law model. Distributions of velocity and temperature are predicted through the simulation.

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A Fault Diagnosis and Control Integrated System for an SP-100 Space Reactor (SP-100 우주선 원자로를 위한 고장진단 및 제어 통합 시스템)

  • Na, Man-Gyun;Yang, Heon-Young;Lim, Dong-Hyuk;Lee, Yoon-Joon
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.231-232
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    • 2007
  • In this paper, a fault diagnosis and control integrated system (FDCIS) was developed to control the thermoelectric (TE) power in the SP-100 space reactor. The objectives of the proposed model predictive control were to minimize both the difference between the predicted TE power and the desired power, and the variation of control drum angle that adjusts the control reactivity. Also, the objectives were subject to maximum and minimum control drum angle and maximum drum angle variation speed. A genetic algorithm was used to optimize the model predictive controller. The model predictive controller was integrated with a fault detection and diagnostics algorithm so that the controller can work properly even under input and output measurement faults. With the presence of faults, the control law was reconfigured using online estimates of the measurements. Simulation results of the proposed controller showed that the TE generator power level controlled by the proposed controller could track the target power level effectively even under measurement faults, satisfying all control constraints.

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Development of a Fission Product Transport Module Predicting the Behavior of Radiological Materials during Severe Accidents in a Nuclear Power Plant

  • Kang, Hyung Seok;Rhee, Bo Wook;Kim, Dong Ha
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.237-244
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    • 2016
  • Background: Korea Atomic Energy Research Institute is developing a fission product transport module for predicting the behavior of radioactive materials in the primary cooling system of a nuclear power plant as a separate module, which will be connected to a severe accident analysis code, Core Meltdown Progression Accident Simulation Software (COMPASS). Materials and Methods: This fission product transport (COMPASS-FP) module consists of a fission product release model, an aerosol generation model, and an aerosol transport model. In the fission product release model there are three submodels based on empirical correlations, and they are used to simulate the fission product gases release from the reactor core. In the aerosol generation model, the mass conservation law and Raoult's law are applied to the mixture of vapors and droplets of the fission products in a specified control volume to find the generation of the aerosol droplet. In the aerosol transport model, empirical correlations available from the open literature are used to simulate the aerosol removal processes owing to the gravitational settling, inertia impaction, diffusiophoresis, and thermophoresis. Results and Discussion: The COMPASS-FP module was validated against Aerosol Behavior Code Validation and Evaluation (ABCOVE-5) test performed by Hanford Engineering Development Laboratory for comparing the prediction and test data. The comparison results assuming a non-spherical aerosol shape for the suspended aerosol mass concentration showed a good agreement with an error range of about ${\pm}6%$. Conclusion: It was found that the COMPASS-FP module produced the reasonable results of the fission product gases release, the aerosol generation, and the gravitational settling in the aerosol removal processes for ABCOVE-5. However, more validation for other aerosol removal models needs to be performed.

Static and Free Vibration Analysis of FGM Plates on Pasternak Elastic Foundation (Pasternak 탄성지반위에 놓인 점진기능재료 판의 정적 및 자유진동 해석)

  • Lee, Won-Hong;Han, Sung-Cheon;Park, Weon-Tae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.6
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    • pp.529-538
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    • 2016
  • The simplified plate theory is presented for static and free vibration analysis of power-law(P) and sigmoid(S) Functionally Graded Materials(FGM) plates. This theory considers the parabolic distribution of the transverse shear stress, and satisfies the condition that requires the transverse shear stress to be zero on the upper and lower surfaces of the plate, without the shear correction factor. The simplified plate theory uses only four unknown variables and shares strong similarities with classical plate theory(CPT) in many aspects such as stress-resultant expressions, equation of motion and boundary conditions. The material properties of the plate are assumed to vary according to the power-law and sigmoid distributions of the volume fractions of the constituents. The Hamilton's principle is used to derive the equations of motion and Winkler-Pasternak elastic foundation model is employed. The results of static and dynamic responses for a simply supported FGM plate are calculated and a comparative analysis is carried out. The results of the comparative analysis with the solutions of references show relevant and accurate results for static and free vibration problems of FGM plates. Analytical solutions for the static and free vibration problems are presented so as to reveal the effects of the power law index, elastic foundation parameter, and side-to-thickness ratio.

A Study on the DC to DC Converter to Improve the Performance of Power LED System (파워 LED 시스템 성능개선을 위한 DC/DC 컨버터에 관한 연구)

  • Kim, Young Tae;Kim, Sei Yoon
    • Journal of Drive and Control
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    • v.19 no.4
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    • pp.85-90
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    • 2022
  • In this paper, a DC converter to improve the performance of Power LED system is discussed. The mathematical model of PWM converter power stage using 3-Terminal PWM cell is introduced for power LED system. A controller for DC converter system is used as a self-tunning regulator with a recursive least-squares algorithm. Minimum variance control method is used as a control law. Experiment results verified that proposed control system could improve the performance of Power LED system.

Maximum Likelihood Estimation of Lifetime Distribution under Stress Bounded Ramp Tests: The Case Where Stress Loaded from Use Condition (스트레스 한계가 있는 램프시험하에서 신뢰수명분포의 최우추정: 사용조건에서부터 스트레스를 가하는 경우)

  • 전영록
    • Journal of Korean Society for Quality Management
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    • v.25 no.2
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    • pp.1-14
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    • 1997
  • This paper considers maximum likelihood (ML) estimation of lifetime distribution under stress bounded ramp tests in which the stress is increased linearly from used condition stress to the stress u, pp.r bound. The following assumptions are used: exponential lifetime distribution under a constant stress, an inverse power law relationship between stress and mean of exponential lifetime distribution, and a cumulative exposure model for the effect of changing stress. Likelihood equations for the parameters involved in the model and asymptotic distribution of the estimators are obtained, and a numerical example is given.

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Accelerated Life Tests under Uniform Stress Distribution (스트레스함수가 균등분포인 가속수명시험)

  • 원영철
    • Journal of the Korea Safety Management & Science
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    • v.2 no.2
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    • pp.71-83
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    • 2000
  • This paper presents accelerated life tests for Type I censoring data under probabilistic stresses. Probabilistic stress, $S_j$, is the random variable for stress influenced by test environments, test equipments, sampling devices and use conditions. The hazard rate, ,$theta_j$, is the random variable of environments and the function of probabilistic stress. Also it is assumed that the general stress distribution is uniform, the life distribution for the given hazard rate, $\theta$, is exponential and inverse power law model holds. In this paper, we obtained maximum likelihood estimators of model parameters and the mean life in use stress condition.

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Design and Experimental Validation of a Digital Predictive Controller for Variable-Speed Wind Turbine Systems

  • Babes, Badreddine;Rahmani, Lazhar;Chaoui, Abdelmadjid;Hamouda, Noureddine
    • Journal of Power Electronics
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    • v.17 no.1
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    • pp.232-241
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    • 2017
  • Advanced control algorithms must be used to make wind power generation truly cost effective and reliable. In this study, we develop a new and simple control scheme that employs model predictive control (MPC), which is used in permanent magnet synchronous generators and grid-connected inverters. The proposed control law is based on two points, namely, MPC-based torque-current control loop is used for the generator-side converter to reach the maximum power point of the wind turbine, and MPC-based direct power control loop is used for the grid-side converter to satisfy the grid code and help improve system stability. Moreover, a simple prediction scheme is developed for the direct-drive wind energy conversion system (WECS) to reduce the computation burden for real-time applications. A small-scale WECS laboratory prototype is built and evaluated to verify the validity of the developed control methods. Acceptable results are obtained from the real-time implementation of the proposed MPC methods for WECS.

A STUDY ON THE IMPROVEMENT OF κ-εTURBULENCE MODEL FOR PREDICTION OF THE RECIRCULATION FLOW (재순환유동 예측을 위한 κ-ε 난류모델 개선에 대한 연구)

  • Lee, Y.M.;Kim, C.W.
    • Journal of computational fluids engineering
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    • v.21 no.2
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    • pp.12-24
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    • 2016
  • The standard ${\kappa}-{\varepsilon}$ and realizable ${\kappa}-{\varepsilon}$ models are adopted to improve the prediction performance on the recirculating flow. In this paper, the backward facing step flows are used to assess the prediction performance of the recirculation zone. The model constants of turbulence model are obtained by the experimental results and they have a different value according to the flow. In the case of an isotropic flow situation, decaying of turbulent kinetic energy should follow a power law behavior. In accordance with the power law, the coefficients for the dissipation rate of turbulent kinetic energy are not universal. Also, the other coefficients as well as the dissipation coefficient are not constant. As a result, a suitable coefficients can be varied according to each of the flow. The changes of flow over the backward facing step in accordance with model constants of the ${\kappa}-{\varepsilon}$ models show that the reattachment length is dependent on the growth rate(${\lambda}$) and the ${\kappa}-{\varepsilon}$ models can be improved the prediction performance by changing the model constants about the recirculating flow. In addition, it was investigated for the curvature correction effect of the ${\kappa}-{\varepsilon}$ models in the recirculating flow. Overall, the curvature corrected ${\kappa}-{\varepsilon}$ models showed an excellent prediction performance.