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Assessing Program-Level Objectives of Space Exploration Architectures Using Portfolio-Optimization Methods

JOURNAL OF SPACECRAFT AND ROCKETS 2021年第5期58卷 1248-1262页

作者： O'Neill, William J. Delaurentis, Daniel A. Purdue Univ Sch Aeronaut & Astronaut 701 West Stadium Ave W Lafayette IN 47906 USA

The large number and significant variety of systems available for space exploration missions produce countless potential architecture combinations. Compounding this are the scheduling intricacies of system life cycle phases and time-dependent operational dependencies, as well as the uncertainty associated with each system and technology in terms of cost, schedule, and performance. Traditional architecting emphasizes the individual design of component systems over the wide-ranging and robust assessment of architecture options early in mission design. A top-down method that can assess the capabilities, requirements, and risks associated with the diversity of available space systems and form optimal portfolios of interdependent systems is necessary. Our work describes and demonstrates a portfolio-optimization technique that can design and assess lunar space exploration architectures by optimizing on programmatic objectives such as cost, performance, schedule, and robustness while simultaneously accounting for system operational interdependencies and schedule dependencies of the selected systems.

关键词： Space Exploration Space Systems Super Heavy Lift Launch Vehicle Chemical Space Propulsion NTR mixed integer linear programming Deep Space Habitat Propulsion System Chemical Rocket Propulsion Earth

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Robust Virtual Network Function Allocation in Service Function Chains With Uncertain Availability Schedule

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IEEE TRANSACTIONS ON NETWORK AND SERVICE MANAGEMENT 2021年第3期18卷 2987-3005页

作者： Kang, Rui He, Fujun Oki, Eiji Kyoto Univ Grad Sch Informat Kyoto 6068501 Japan

The availability schedule provides information on whether each network node is available at each time slot. The service interruptions caused by node unavailability marked in availability schedule can be suppressed if the functions are allocated according to the availability schedule. However, the given availability schedule may have gaps with the actual one and influence the VNF allocation. This paper proposes a robust optimization model to allocate virtual network functions (VNFs) in service function chains (SFCs) for time slots in sequence aiming to maximize the continuous available time of SFCs in a network with uncertain availability schedules by suppressing the interruptions caused by node unavailability marked in availability schedule and function reallocation. We formulate the problem as a mixed integer linear programming (MILP) problem over the given uncertainty set of the start time slot and period of unavailability on each node in the availability schedule. For solving the model in a practical time in a relative large size of network, we develop a heuristic algorithm. The numerical results show that the proposed model outperforms the baseline models under different levels of robustness in terms of the worst-case minimum number of the longest continuous available time slot in each SFC. The heuristic algorithm reduces the computation time with limited performance loss compared with the MILP approach. In the discussion, we introduce a constraint condition for the maintenance ability, which reduces the size of uncertainty set, and an extension for supporting more than one unavailability periods in the availability schedule on each node.

关键词： Schedules Resource management Maintenance engineering Numerical models Uncertainty Robustness Measurement Network function virtualization virtual network function allocation service function chain availability schedule mixed integer linear programming

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Distributionally robust chance constrained planning model for energy storage plants based on Kullback-Leibler divergence

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ENERGY REPORTS 2021年 7卷 5203-5213页

作者： Le, Jian Liao, Xiaobing Zhang, Lina Mao, Tao Wuhan Univ Sch Elect Engn & Automat Wuhan 430072 Peoples R China Wuhan Inst Technol Sch Elect & Informat Engn Wuhan 430205 Peoples R China State Grid Shanxi Elect Power Corp Taiyuan 030001 Shanxi Peoples R China Wuhan Donghu Univ Wuhan 430074 Peoples R China

Nowadays, the high penetration of renewable energy, with variable and unpredictable nature, poses major challenges to operation and planning studies of power systems. Employing energy storage plants has been introduced as an effective solution to alleviate these challenges. Several studies have been presented in the literature to provide a framework for planning studies of energy storage plants. However, they usually have two main drawbacks: (i) ignoring the lifetime varying characteristic of energy storage, (ii) inability to model the charge/discharge schedule of energy storage accurately. This paper amends the abovementioned shortcomings by proposing a distributionally robust planning method based on Kullback-Leibler divergence. According to the power function of lifespan of electrochemical energy storage, the lifespan model of energy storage plants with equivalent full cycles times is established. Considering the lifespan model constraints of the energy storage plant and system operating constraints, the planning model of energy storage plants is constructed with the lifespan cycle cost and units' operation cost as the objective. Furthermore, the ambiguity set of wind farm output based on Kullback-Leibler divergence is embedded into the planning model of energy storage plants, and the distributionally robust planning model of energy storage plant is transformed into mixed integer linear programming model by sample average approximation method. A modified IEEE-30 bus system with two wind farms is studied to demonstrate the effectiveness. The results show distributionally robust planning model reduces about 10% planning cost compared with the traditional robust planning model, and increases the energy storage capacity by 12MW compared with the stochastic planning method. Other, the planning cost of energy storage plants will decrease by 5% similar to 23% when the wind abandoned rate increases by 2% and decreases slowly with the increase of abandoned wind rate. (C)

关键词： Electrochemical energy storage Ambiguity set Distributionally robust planning Sample average approximation method mixed integer linear programming

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Simultaneous node and link districting in transportation networks: Model, algorithms and railway application

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2021年第1期292卷 73-94页

作者： Wang, Dian Zhao, Jun D'Ariano, Andrea Peng, Qiyuan Southwest Jiaotong Univ Sch Transportat & Logist Chengdu 611756 Sichuan Peoples R China Roma Tre Univ Dept Engn I-00146 Rome Italy Southwest Jiaotong Univ Natl United Engn Lab Integrated & Intelligent Tra Chengdu 611756 Sichuan Peoples R China

Partitioning a large network into multiple subnetworks is adopted extensively in various practical applications involving the architecture of distributed management. In this study, we consider strategic simultaneous node and link districting to partition the nodes and links of a given transportation network into a fixed number of mutually disjoint districts, based on the districting criteria of integrity, contiguity, balance, and independence. We first formulate the resulting problem as a mixed integer linear programming model to minimize the weighted sum of the total size deviation of districts and total cooperation between districts. An improved network flow-based technique is proposed to incorporate the complicated contiguity criterion by using a polynomial number of constraints. Valid inequalities, which break the symmetry within and between districts, are designed to strengthen the model. To solve this challenge problem, we reformulate it as a binary linear programming model, and develop a column generation-based algorithm to find tight lower bounds and good-quality solutions. Then, an iterative search algorithm is designed to obtain good-quality solutions rapidly. Furthermore, a more efficient hybrid algorithm is proposed by using the results of the iterative search algorithm to initialize the column generation-based algorithm. We assess the proposed model and algorithms by using various scales of instances derived from the train dispatcher desk districting problem, which is a practical application of the investigated problem in the context of railway. The computational results reveal that our approaches outperform existing approaches and a commercial solver, and our best algorithm can solve almost all the investigated instances to optimality within a considerably short average computation time. The districting solutions of our approaches are also better than the empirical solutions designed by railway managers mainly based on experience. (C) 2020 Elsevier B.V

关键词： Transportation Districting mixed integer linear programming Column generation Iterative search

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Scheduling the capacitated identical parallel machines problem: a new formulation with sequence-dependent setup costs and different due dates

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EUROPEAN JOURNAL OF INDUSTRIAL ENGINEERING 2021年第5期15卷 643-674页

作者： Esmaelian, Majid Sobhani, Ahmad Shahmoradi, Hadi Mohammadi, Milad Univ Isfahan Dept Management Hezarjerib StAzadi Sq Esfahan Iran Oakland Univ Sch Business Adm Dept Decis & Informat Sci Rochester MI 48063 USA

This paper schedules capacitated parallel machines of a real production system by considering different quantities of production and processing times required to complete customer orders. A new mixed linear programming model is developed according to the concept of constrained vehicle routing problems to have a complete schedule for machines by determining the sequence of both jobs and idle times for each machine. The optimisation model minimises the total cost of the production system, including tardiness, earliness and sequence-dependent setup costs. A constraint programming (CP) model and a meta-heuristic hybrid algorithm are also developed to compare their results with the mixed linear programming model. The numerical findings show that the total cost estimated by the mixed integer programming model is 10%-13% better (lower) than the ones estimated by the CP model and the meta-heuristic algorithm when small instances of the scheduling problem are solved. By increasing the size of the scheduling problem, the meta-heuristic algorithm shows the best computational performance estimating 11% better (lower) total cost compared with the CP model.

关键词： capacitated identical parallel machines constrained vehicle routing problem mixed integer linear programming constraint programming meta-heuristic algorithm

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Data-driven model predictive control for vehicle path-tracking using a recurrent neural network

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IFAC-PapersOnLine 2024年第29期58卷 367-372页

作者： Jian Yi Xialai Wu Ling Lin Jiabin Qin Junghui Chen *Huzhou Key Laboratory of Intelligent Sensing and Optimal Control for Industrial Systems Huzhou University Huzhou 313000 China **Huzhou Key Laboratory of Intelligent Sensing and Optimal Control for Industrial Systems Huzhou University Huzhou 313000 China ***Huzhou Key Laboratory of Intelligent Sensing and Optimal Control for Industrial Systems Huzhou University Huzhou 313000 China ****Huzhou Key Laboratory of Intelligent Sensing and Optimal Control for Industrial Systems Huzhou University Huzhou 313000 China *****Department of Chemical Engineering Chung-Yuan Christian University Taoyuan Taiwan 32023 Republic of China

Path tracking control is crucial for autonomous vehicle driving. Traditional nonlinear model predictive control (NMPC) for path tracking demands extensive computation, making real-time implementation challenging. This paper introduces a Fast Model Predictive Control (FMPC) method for vehicle path tracking, utilizing a recurrent neural network (RNN) with symmetric saturating linear transfer functions (SSL-RNN) in the hidden layer. The proposed approach leverages the SSL-RNN model to accurately capture vehicle dynamics. Consequently, the optimal control problem in MPC is reformulated as a mixed integer linear programming problem, facilitating swift solutions. Simulation experiments validate the proposed method's efficacy. Compared to traditional vehicle mechanism model-based MPC and RNN-based NMPC, our FMPC demonstrates superior accuracy in path tracking and significantly enhances controller solution efficiency.

关键词： model predictive control mixed integer linear programming symmetric saturating linear transfer function recurrent neural network vehicle path tracking

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On the Problem of Increasing the Railway Station Capacity

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AUTOMATION AND REMOTE CONTROL 2021年第1期82卷 102-114页

作者： Ignatov, A. N. Naumov, A., V Moscow Inst Aviat Technol Moscow 125993 Russia

We consider the problem of increasing the capacity of a railway station taking into account some basic timetable for the station. To this end, the time and route for each additional train are determined by solving a set of mixed integer linear programming problems. A scheme is proposed to take into account the influence of random delays in the movement of trains on the possibility of their passage through the railway station. The results of a numerical experiment are presented.

关键词： railway station capacity graph mixed integer linear programming

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Real-time integrated train rescheduling and rolling stock circulation planning for a metro line under disruptions

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TRANSPORTATION RESEARCH PART B-METHODOLOGICAL 2021年 152卷 87-117页

作者： Wang, Yihui Zhao, Kangqi D'Ariano, Andrea Niu, Ru Li, Shukai Luan, Xiaojie Beijing Jiaotong Univ State Key Lab Rail Traff Control & Safety Beijing 100044 Peoples R China Roma Tre Univ Dept Engn I-00146 Rome Italy Swiss Fed Inst Technol Inst Transport Planning & Syst IVT Stefano Franscini Pl 5 CH-8093 Zurich Switzerland

More and more unexpected events occur in metro systems, which may cause serious disturbances and even disruptions for the operation of trains. This paper studies an integrated train rescheduling and rolling stock circulation planning problem for the complete blockage situations in a metro line. We consider several key practical train operation constraints, including the maximum number of available rolling stocks, the turnaround constraints, the service connection constraints. This problem is viewed as a complex multi-objective mixed integer linear programming (MILP) formulation, where the objectives involve the deviations with respect to the timetable, the (partial) cancellations, and the headway deviations of train services. A two-stage approach is also developed to enhance the computational efficiency, where a smaller-size optimization problem is solved in the first stage, by considering a set of key turnaround stations only, while the original MILP problem is solved in the second stage by fixing some binary variables according to the first stage solution. In addition, we propose a heuristic technique that is based on introducing a new set of constraints to reduce the search space without eliminating potentially good solutions. Comprehensive experiments are investigated based on the practical data of Beijing Subway Lines, where the proposed integrated models and approaches yield much better solutions when compared with a widely used strategy, i.e., holding (waiting at station) strategy and the sequential approach. Moreover, the impacts of the complete blockage locations/durations and the effects of different weight settings in the multi-objective optimization are deeply analyzed.

关键词： Metro lines Complete track blockage Railway traffic management Rolling stock circulation Short-turning mixed integer linear programming

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WEEE closed-loop supply chain network management considering the damage levels of returned products (Oct, 10.1007/s11356-020-10249-6, 2020)

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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 2021年第7期28卷 7805-7805页

作者： Polat, Leyla Ozgur Gungor, Askiner Pamukkale Univ Dept Ind Engn TR-20160 Denizli Turkey

Due to economic, social, and environmental concerns, managing waste electrical and electronic equipment (WEEE) has become an important research area. The WEEE directive gives responsibility to producers for developing a system for recycling and disposal activities and handle all associated costs. This study proposes a mixed integer programming model for decision-makers to manage their activities on the WEEE closed-loop supply chain network. A decision-maker may be a single producer of any size or a managing body formed by a group of producers and/or third-party companies in the network. The model contributes to the research field by integrating product returns with different quality and damage levels. A set of scenarios was designed to evaluate the effects of the directive and the network design related issues (e.g., the minimum collection rates, the number of producers and stores in the network) on the objective function. The results indicate that the capacity balance among stores, producers, and recovery centers is vital to make the network profitable and sustainable.

关键词： Waste electrical and electronic equipment E-waste Closed-loop supply chain network Recycling mixed integer linear programming

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A new model for minimizing the electric vehicle battery capacity in electric travelling salesman problem with time windows

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TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES 2021年第5期29卷 2545-2560页

作者： Erdogdu, Kazim Karabulut, Korhan Yasar Univ Fac Engn Dept Software Engn Izmir Turkey

The growing pollution in the environment and the negative shift in the global climate compel authorities to take action to protect the environment and human health. Transportation is one of the major contributors to this environmental decay. The harmful gases released to the air by the vehicles using petroleum fuel increase each day. One of the solutions is to make a gradual transition to electric vehicles. A major part of manufacturing an electric vehicle is to produce an efficient electric motor and battery for it. Reducing the manufacturing and operating costs of these components will result in reducing the overall costs of electric vehicles. In this study, a new variant of the electric travelling salesman problem with time windows (E-TSPTW) was proposed. The objective function of the problem is to minimize the required initial battery capacity of the electric vehicle. For this goal, a new energy consumption model considering the load of the vehicle was proposed with three scenarios. The proposed model was solved with a hybrid simulated annealing algorithm for all these scenarios. The performance of the proposed method was compared to the solutions found by a mixed integer linear programming model. The experimental results on the benchmark instances show that up to a 35% reduction in initial battery capacity, hence reduction in its cost is possible.

关键词： Electric travelling salesman problem with time windows energy consumption battery capacity mixed integer linear programming simulated annealing

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