• Title/Summary/Keyword: Non-equilibrium

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Cooperative User Equilibrium Under Advanced Traveler Information Systems (첨단교통정보체계(ATIS)하에서 협력적 사용자 균형)

  • Lim Yong-Taek
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.4 no.1 s.6
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    • pp.81-88
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    • 2005
  • Cooperation among network users would be possible in a near future, as real time communication between them can be available by telematics. This implies that non-cooperative assumption like Wardrop's principle, which has been widely used so far in network modelling may not be appropriate for route choice problem. So a new principle requires for describing such cooperative case. This paper presents a criterion, which represents cooperative route choice behaviour among network users. With some examples, we compare the non-cooperative principle and the cooperative one presented in this paper. Numerical results from the examples show that the new principle would be better than the existing one.

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Design of the Air Pressure Pick-up Head for Non-Contact Wafer Gripper (비접촉식 웨이퍼 그리퍼용 공압 파지식 헤드 설계)

  • Kim, Joon-Hyun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.401-407
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    • 2012
  • The recent manufacturing process in the thin wafers and flat panel necessitate new approaches to reduce handling fragile and surface-sensitive damage of components. This paper presents a new pneumatic levitation for non-contact handling of parts and substrates. This levitation can achieve non-contact handling by blowing air into an air pressure pick-up head with radial passages to generate a negative pressure region. Negative pressure is caused by the radial air flow by nozzle throat and through holes connecting to the bottom region. The numerical analysis deals with the levitational motion with different design factors. The dynamic motion is examined in terms of force balance(dynamic equilibrium) occurring to the flow field between two objects. The stable equilibrium position and the safe separation distance are determined by analyzing the local pressure distribution in the fluid motion. They make considerable design factors consisting the air pressure pick-up head. As a result, in case that the safe separation distance is beyond 0.7mm, the proposed pick-up head can levitate stably at the equilibrium position. Furthermore, it can provide little effect of torque, and obtain more wide picking region according to the head size.

An Improved Generation Maintenance Strategy Analysis in Competitive Electricity Markets Using Non-Cooperative Dynamic Game Theory (비협조 동적게임이론을 이용한 경쟁적 전력시장의 발전기 보수계획 전략 분석)

  • 김진호;박종배;김발호
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.9
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    • pp.542-549
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    • 2003
  • In this paper, a novel approach to generator maintenance scheduling strategy in competitive electricity markets based on non-cooperative dynamic game theory is presented. The main contribution of this study can be considered to develop a game-theoretic framework for analyzing strategic behaviors of generating companies (Gencos) from the standpoints of the generator maintenance-scheduling problem (GMP) game. To obtain the equilibrium solution for the GMP game, the GMP problem is formulated as a dynamic non-cooperative game with complete information. In the proposed game, the players correspond to the profit-maximizing individual Gencos, and the payoff of each player is defined as the profits from the energy market. The optimal maintenance schedule is defined by subgame perfect equilibrium of the game. Numerical results for two-Genco system by both proposed method and conventional one are used to demonstrate that 1) the proposed framework can be successfully applied in analyzing the strategic behaviors of each Genco in changed markets and 2) both methods show considerably different results in terms of market stability or system reliability. The result indicates that generator maintenance scheduling strategy is one of the crucial strategic decision-makings whereby Gencos can maximize their profits in a competitive market environment.

Supercooled Liquid, Glass and Glass Transition (과냉각 액체, 유리 그리고 유리 전이)

  • Kim, Hack-Jin
    • Journal of the Korean Chemical Society
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    • v.53 no.2
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    • pp.99-110
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    • 2009
  • Characteristics of supercooled liquid and glass, which are the states involved in glass transition, are reviewed. These states are non-equilibrium states, therefore, the glass transition is different from the usual phase transitions. Theories of glass transition and related experimental methods are briefly summarized.

Aero-optical effects in the hypersonic flow field

  • Shi, Ketian;Miao, Wenbo;Li, Pengfei;Chen, Xiaoli
    • International Journal of Aerospace System Engineering
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    • v.2 no.1
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    • pp.12-17
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    • 2015
  • Aero-optical effects induced by the flow around the optical window degrade the performance of the IR seeker, especially for the hypersonic flow. For the thermochemical non-equilibrium flow, index of refraction model and optical transmission calculation method are developed to predict the aero-optical effects. The optical distortion is discussed for the typical optical widow shape and flow condition. The influence on aero-optical effects is analyzed.

Prediction of Burnt Gas Properties for Kerosene Fuel-rich Preburner (케로신 연료과잉 예연소기의 연소가스 물성치 예측)

  • Son, Min;Seo, Min-Kyo;Koo, Ja-Ye
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.123-126
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    • 2011
  • A Fuel-rich preburner using kerosene fuel is operated in a non-equilibrium condition and a prediction of burnt-gas properties is not easy from a chemical equilibrium analysis. A premixed counter-flow flame analysis was conducted for the prediction of burnt-gas properties. JP10 was selected for a representative kerosene fuel and a non-equilibrium combustion analysis was accomplished in supercritical condition using UC San Diego reaction mechanism. The premixed counter-flow flame was assumed for stationary and stable flame, and the temperature result in present study was overestimated rather than the experimental results from Huzel. From the difference of the temperature result, other properties, heat capacity, specific heat ratio and molecular weight had some differences against the experimental results. Moreover, the present results was more similar to the experimental results than those of the equilibrium analysis.

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THE SHRINKING PROJECTION METHODS FOR HEMI-RELATIVELY NONEXPANSIVE MAPPINGS, VARIATIONAL INEQUALITIES AND EQUILIBRIUM PROBLEMS

  • Wang, Zi-Ming;Kang, Mi Kwang;Cho, Yeol Je
    • Communications of the Korean Mathematical Society
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    • v.28 no.1
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    • pp.191-207
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    • 2013
  • In this paper, we introduce the shrinking projection method for hemi-relatively nonexpansive mappings to find a common solution of variational inequality problems and equilibrium problems in uniformly convex and uniformly smooth Banach spaces and prove some strong convergence theorems to the common solution by using the proposed method.

NUMERICAL MODEL ON THE FUEL INJECTION CHARACTERISTICS FOR PREDICTING EXHAUST EMISSIONS FROM A MARINE DIESEL ENGINE

  • LEE S.-Y.;KIM G.-B.;JEON C.-H.;CHANG Y.-J.
    • International Journal of Automotive Technology
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    • v.6 no.3
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    • pp.205-213
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    • 2005
  • This study deals with the result of exhaust emissions and performance calculated by simulation of the fuel injection characteristics of the inline injection system in a marine diesel engine. The emissions are calculated through non-equilibrium by using the extended Zel'dovich kinetic mechanism for NOx and equilibrium method for OH, CO, $H_2$, Hand soot concentrations. Comparisons of the model predictions with the experimental values show reasonable agreement. Detailed prediction results showing the sensitivity of the model by injection rates are presented and discussed.

Non-equilibrium Monte Carlo Simulations for Critical Flux of Hard Sphere Suspensions in Crossflow Filtration

  • Kim, Albert S.
    • Proceedings of the Membrane Society of Korea Conference
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    • 2008.05a
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    • pp.33-47
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    • 2008
  • Non-equilibrium (irreversible) themodynamics is used to investigate colloidal back-diffusion during crossflow membrane filtration. The chemical potential is generalized as a superposition of equilibrium and irreversible contributions, originating from Brownian and shear-induced diffusion, respectively. As a result, an effective drag force is derived using the irreversible thermodynamics for a particle undergoing both Brownian and shear-induced diffusion in a sheared concentrated suspension. Using the drag force, a hydrodynamic force bias Monte Carlo method is developed for crossflow membrane filtration to determine the critical flux of hard sphere suspensions. Effects of shear rate and particle size on the critical flux are studied, and results show a good agreement with experimental observations reported in the literature.

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Non-equilibrium Molecular Dynamics Simulations of Thermal Transport Coefficients of Liquid Water

  • Song Hi Lee;Gyeong Keun Moon;Sang Gu Choi
    • Bulletin of the Korean Chemical Society
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    • v.12 no.3
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    • pp.315-322
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    • 1991
  • In a recent $paper^1$ we reported equilibrium (EMD) and non-equilibrium (NEMD) molecular dynamics simulations of liquid argon using the Green-Kubo relations and NEMD algorithms to calculate the thermal transport coefficients-the self-diffusion coefficient, shear viscosity, and thermal conductivity. The overall agreement with experimental data is quite good. In this paper the same technique is applied to calculate the thermal transport coefficients of liquid water at 298.15 K and 1 atm using TIP4P model for the interaction between water molecules. The EMD results show difficulty to apply the Green-Kubo relations since the time-correlation functions of liquid water are oscillating and not decaying rapidly enough except the velocity auto-correlation function. The NEMD results are found to be within approximately ${\pm}$30-40% error bars, which makes it possible to apply the NEMD technique to other molecular liquids.