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Fuel Inventory of the Multi-Bed Storage System of the SDS Considering Daily Operation of the Tokamak

FUSION SCIENCE AND TECHNOLOGY 2017年第3期71卷 296-304页

作者： Lee, Jae-Uk Chang, Min Ho Yun, Sei-Hun Ha, Jin-Kuk Lee, Euy Soo Lee, In-Beum Pohang Univ Sci & Technol Dept Chem Engn San 31 Pohang 790784 South Korea Natl Fus Res Inst 169-148 Gil Kwahak Ro Daejon 34133 South Korea Dongguk Univ Dept Chem Biochem Engn Seoul 100715 South Korea

A Tokamak has startup and shutdown periods during which demand specifications differ from those during steady fueling operation. These periods can affect the required number of getter beds of the Storage and Delivery System. In this study, we developed a mathematical model based on the State Task Network, and an algorithm that considers daily operation which includes the period from startup to shutdown to find the optimal number of getter beds. This algorithm can estimate the optimal initial inventory of tritium or deuterium in a getter bed to compensate for fuel consumption until shutdown. The inductive operation mode of the Tokamak is analyzed to illustrate the applicability of the model and algorithm.

关键词： Storage and delivery system multi-bed system mixed integer nonlinear programming

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Global optimization of mass and property integration networks with in-plant property interceptors

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CHEMICAL ENGINEERING SCIENCE 2010年第15期65卷 4363-4377页

作者： Napoles-Rivera, Fabricio Maria Ponce-Ortega, Jose El-Halwagi, Mahmoud M. Jimenez-Gutierrez, Arturo Inst Tecnol Celaya Dept Chem Engn Celaya Gto Mexico Univ Michoacana Dept Chem Engn Morelia Mich Mexico Texas A&M Univ Dept Chem Engn College Stn TX 77843 USA

This paper presents a mathematical programming model for the optimal design of mass and property integration networks that include property interceptors with in the structure of the network, as opposed to the end-of-pipe use of such interceptors. The model is based on are cycle and reuse scheme that simultaneously satisfies process and environmental constraints. The properties considered in this work are composition, toxicity, theoretical oxygen demand, pH, density and viscosity. The property mixing rules included in the model give rise to bilinear terms for the property operators, and a global optimization algorithm is used for the solution of the model. The model minimizes the total annual cost of the network, which includes the fresh sources cost and the annualized property treatment system and the piping costs. Three examples are included to show the applicability and advantages of the proposed model. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Mass integration Property integration mixed integer nonlinear programming Mathematical modeling Optimization Chemical processes Design

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A mixed integer Formulation for Energy-efficient Multistage Adsorption Dryer Design

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DRYING TECHNOLOGY 2012年第8期30卷 873-883页

作者： Atuonwu, J. C. van Straten, G. van Deventer, H. C. van Boxtel, A. J. B. Wageningen Univ Syst & Control Grp NL-6700 AA Wageningen Netherlands TNO NL-3700 AJ Zeist Netherlands

This work presents a mixed integer nonlinear programming (MINLP) formulation for the design of energy-efficient multistage adsorption dryers within constraints on product temperature and moisture content. Apart from optimizing temperatures and flows, the aim is to select the most efficient adsorbent per stage and product to air flow configuration. Superstructure models consisting of commonly used adsorbents such as zeolite, alumina, and silica-gel are developed and optimized for a two-stage, low-temperature, adsorption drying system. Results show that the optimal configuration is a hybrid system with zeolite as the first-stage adsorbent and silica-gel as the second-stage adsorbent in counter-current flow between drying air and product. A specific energy consumption of 2,275 kJ/kg is achieved, which reduces to 1,730 kJ/kg with heat recovery by a heat exchanger. Compared to a conventional two-stage dryer at the same drying temperature, this represents a 59% reduction in energy consumption. The optimal system ensures the exhaust air temperature of the first-stage regenerator is high enough to regenerate the second-stage adsorbent so no utility energy is spent in the second stage. A higher second-stage adsorbent wheel speed favors energy performance as it becomes optimized for energy recovery while the first is optimized for dehumidification. Although this work considers three candidate adsorbents in a two-stage system, the same reasoning can be applied to systems with more stages and adsorbents. The developed superstructure optimization methodology can, by extension, be applied to optimize multistage hybrid drying systems in general for any objective.

关键词： Adsorption drying Dryer energy optimization Hybrid dryers mixed integer nonlinear programming Multistage dryers Product quality

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A computational study of primal heuristics inside an MI(NL)P solver

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JOURNAL OF GLOBAL OPTIMIZATION 2018年第1期70卷 189-206页

作者： Berthold, Timo FICO Xpress Optimizat Berlin Germany

Primal heuristics are a fundamental component of state-of-the-art global solvers for mixed integer linear programming (MIP) and mixed integer nonlinear programming (MINLP). In this paper, we investigate the impact of primal heuristics on the overall solution process. We present a computational study, in which we compare the performance of the MIP and MINLP solver SCIP with and without primal heuristics on six test sets with altogether 983 instances from academic and industrial sources. We analyze how primal heuristics affect the solver regarding seven different measures of performance and show that the impact differs by orders of magnitude. We further argue that the harder a problem is to solve to global optimality, the more important the deployment of primal heuristics becomes.

关键词： mixed integer nonlinear programming Primal heuristics Computational study

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Model Predictive Decision-Making Considering Lane-Changing Time Under Emergency Collision Avoidance for Intelligent Vehicles

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2024年第9期71卷 11250-11261页

作者： Dai, Qikun Liu, Jun Guo, Hongyan Chen, Hong Cao, Dongpu Jilin Univ Coll Commun Engn Natl Key Lab Automot Chassis Integrat & Bion Campus NanLing Changchun 130025 Peoples R China Jilin Univ Coll Automot Engn Campus NanLing Changchun 130025 Peoples R China Jilin Univ Coll Commun Engn Campus NanLing Changchun 130025 Peoples R China Tongji Univ Coll Elect & Informat Engn Shanghai 201804 Peoples R China Univ Waterloo Dept Mech & Mechatron Engn Waterloo ON N2L 3G1 Canada

When a vehicle faces an imminent collision, it becomes imperative for intelligent vehicles to make emergency collision avoidance decisions in order to mitigate traffic accidents and reduce injuries. To address collision avoidance in emergency scenarios, this study proposes a model predictive decision-making (MPDM) approach that incorporates the consideration of lane-changing time. First, a simplified integrated longitudinal and lateral decision-making model is established, and its accuracy is validated through comparison with real vehicle data. Second, a mixed integer nonlinear MPDM is designed to optimize emergency collision avoidance decisions. Within this framework, the minimum lane-changing time for intelligent vehicles is analytically derived based on vehicle dynamics, taking into account varying speeds and adhesion coefficients. Third, by reducing the dimensionality of the lane-changing time optimization variables, an equivalent suboptimization problem is introduced, which consequently diminishes the computational complexity of solving the optimization problem. Finally, a comparative analysis was performed between the MPDM method and several alternative approaches, employing Simulink-SCANeR cosimulation. Furthermore, the MPDM method was validated on a real vehicle. The results obtained highlight a significant enhancement in the safety and stability of collision avoidance due to the MPDM.

关键词： Decision making Collision avoidance Intelligent vehicles Vehicle dynamics Roads Predictive models Radar tracking Accelerated computing collision avoidance decision-making intelligent vehicle mixed integer nonlinear programming model predictive control (MPC)

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An integrated framework for scheduling and control using fast model predictive control

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AICHE JOURNAL 2015年第10期61卷 3304-3319页

作者： Zhuge, Jinjun Ierapetritou, Marianthi G. Rutgers State Univ Dept Chem & Biochem Engn Piscataway NJ 08854 USA

Integration of scheduling and control involves extensive information exchange and simultaneous decision making in industrial practice (Engell and Harjunkoski, Comput Chem Eng. 2012;47:121-133;Baldea and Harjunkoski I, Comput Chem Eng. 2014;71:377-390). Modeling the integration of scheduling and dynamic optimization (DO) at control level using mathematical programming results in a mixed integer Dynamic Optimization which is computationally expensive (Flores-Tlacuahuac and Grossmann, Ind Eng Chem Res. 2006;45(20):6698-6712). In this study, we propose a framework for the integration of scheduling and control to reduce the model complexity and computation time. We identify a piece-wise affine model from the first principle model and integrate it with the scheduling level leading to a new integration. At the control level, we use fast Model Predictive Control (fast MPC) to track a dynamic reference. Fast MPC also overcomes the increasing dimensionality of multiparametric MPC in our previous study (Zhuge and Ierapetritou, AIChE J. 2014;60(9):3169-3183). Results of CSTR case studies prove that the proposed approach reduces the computing time by at least two orders of magnitude compared to the integrated solution using mp-MPC. (c) 2015 American Institute of Chemical Engineers AIChE J, 61: 3304-3319, 2015

关键词： integration of scheduling and control piece-wise affine approximation fast model predictive control Multiparametric model predictive control mixed integer nonlinear programming

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A note on solving DiDi's driver-order matching problem

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OPTIMIZATION LETTERS 2021年第1期15卷 109-125页

作者： Liu, Yanchao Wayne State Univ Dept Ind & Syst Engn 4815 4th StRm 2169 Detroit MI 48202 USA

This paper investigates the combinatorial nonlinear programming model that DiDi proposed for solving their driver-order matching problem. The model is reformulated to an equivalent continuous nonlinear program which is amenable to efficient commercial solvers. A backward induction procedure for computing the lower bound is also proposed. Computational experiments demonstrate that the local solution produced by the reformulation becomes increasingly close to the global solution, thereby suggesting a diminishing marginal benefit of pursing global optimality as the problem size increases.

关键词： Combinatorial optimization Submodular welfare problem mixed integer nonlinear programming Transportation applications

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New multi-objective optimization problem for secure bilateral transaction determination with UPFC in hybrid electricity markets

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ELECTRIC POWER COMPONENTS AND SYSTEMS 2008年第6期36卷 555-574页

作者： Sharma, Ashwani Kumar Chanana, S. Natl Inst Technol Dept Elect Engn Kurukshetra 136119 Haryana India

This article proposes a new multi-objective non-linear optimization problem for secure bilateral transaction determination using AC distribution factors for pool and bilateral coordinated markets. The new multi-objective optimization problem considers minimization of deviations from scheduled transactions and real power losses in the network. The bilateral transaction matrix and generation pattern has been determined in the presence of optimally located unified power-flow controller. The results have also been compared with the secure bilateral transaction determination, minimizing only deviations from the proposed transactions. The proposed technique has been applied on an IEEE 24-bus reliability test system.

关键词： secure transaction matrix transaction matrix pattern mixed integer nonlinear programming unified power-flow controller location AC distribution factors

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The multi-product newsboy problem with supplier quantity discounts and a budget constraint

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2010年第2期206卷 350-360页

作者： Zhang, Guoqing Univ Windsor Dept Ind & Mfg Syst Engn Windsor ON N9B 3P4 Canada

This paper considers the multi-product newsboy problem with both supplier quantity discounts and a budget constraint, while each feature has been addressed separately in the literature. Different from most previous nonlinear optimization models on the topic, the problem is formulated as a mixed integer nonlinear programming model due to price discounts. A Lagrangian relaxation approach is presented to solve the problem. Computational results on both small and large-scale test instances indicate that the proposed algorithm is extremely effective for the problem. An extension to multiple constraints and preliminary computational results are also reported. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Inventory Newsboy model Quantity discount Budget constraint Lagrangian relaxation mixed integer nonlinear programming

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Heuristic algorithms for the general nonlinear separable knapsack problem

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COMPUTERS & OPERATIONS RESEARCH 2011年第2期38卷 505-513页

作者： D'Ambrosio, Claudia Martello, Silvano Univ Bologna DEIS I-40136 Bologna Italy

We consider the nonlinear knapsack problem with separable nonconvex functions. Depending on the assumption on the integrality of the variables, this problem can be modeled as a nonlinear programming or as a (mixed) integer nonlinear programming problem. In both cases, this class of problems is very difficult to solve, both from a theoretical and a practical viewpoint. We propose a fast heuristic algorithm, and a local search post-optimization procedure. A series of computational comparisons with a heuristic method for general nonconvex mixed integer nonlinear programming and with global optimization methods shows that the proposed algorithms provide high-quality solutions within very short computing times. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： nonlinear knapsack Nonconvexity Separable knapsack Heuristic Local search mixed integer nonlinear programming

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