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integer linear programming model for allocation and migration of data blocks in the STT-RAM-based hybrid caches

IET COMPUTERS AND DIGITAL TECHNIQUES 2020年第3期14卷 97-106页

作者： Khajekarimi, Elyas Jamshidi, Kamal Vafaei, Abbas Univ Isfahan Fac Comp Engn Esfahan Iran

Spin-transfer torque random access memory (STT-RAM) has emerged as an eminent choice for the larger on-chip caches due to high density, low static power consumption and scalability. However, this technology suffers from long latency and high energy consumption during a write operation. Hybrid caches alleviate these problems by incorporating a write-friendly memory technology such as static random access memory along with STT-RAM technology. The proper allocation of data blocks has a significant effect on both performance and energy consumption in the hybrid cache. In this study, the allocation and migration problem of data blocks in the hybrid cache is examined and then modelled using integer linear programming (ILP) formulations. The authors propose an ILP model with three different objective functions which include minimising access latency, minimising energy and minimising energy-delay product in the hybrid cache. Evaluations confirm that the proposed ILP model obtains better results in terms of energy consumption and performance compared to the existing hybrid cache architecture.

关键词： random-access storage cache storage power aware computing integer programming linear programming SRAM chips integer linear programming model data blocks STT-RAM-based hybrid caches spin-transfer torque random access memory on-chip caches low static power consumption long latency energy consumption high energy consumption write-friendly memory technology static random access memory STT-RAM technology proper allocation migration problem modelled using integer linear programming formulations ILP model minimising energy-delay product existing hybrid cache architecture

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An integer linear programming model to Select and Temporally Allocate Resources for Fighting Forest Fires

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FORESTS 2018年第10期9卷 583-583页

作者： Rodriguez-Veiga, Jorge Jose Ginzo-Villamayor, Maria Casas-Mendez, Balbina Technol Inst Ind Math ITMATI Santiago De Compostela 15705 Spain Univ Santiago de Compostela Dept Stat Math Anal & Optimizat Modestya Res Grp Santiago De Compostela 15705 Spain Fac Math Campus Vida S-N Santiago De Compostela 15782 Spain

Optimal planning of the amount and type of resources needed for extinguishing a forest fire is a task that has been addressed in the literature, using models obtained from operational research. In this study, a general integer linear programming model is proposed, which addresses the allocation of resources in different time periods during the planning period for extinguishing a fire, and with the goal of meeting Spanish regulations for the non-negligence of fronts and periods of rest for pilots and brigades. A computer program and interface were developed using the R language. By means of an example using historical data, we illustrate the model at work and its exact resolution. Then, we carry out a simulation study to analyze the obtained objective functions and resolution times. Our simulation study shows that an exact solution can be obtained very quickly without requiring heuristic algorithms, provided that the planning period does not exceed five hours.

关键词： wildfire suppression resource planning time allocation integer linear programming model simulation study interface

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integer linear programming model and satisfiability test reduction for distance constrained labellings of graphs: the case of L(3,2,1) labelling for products of paths and cycles

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IET COMMUNICATIONS 2013年第8期7卷 715-720页

作者： Shao, Zehui Vesel, Aleksander Chengdu Univ Sch Informat Sci & Technol Chengdu 610106 Peoples R China Univ Maribor Fac Nat Sci & Math SLO-2000 Maribor Slovenia

Let u and v be vertices of a graph G = (V, E) and d(u, v) be the distance between u and v in G. For positive integers k(1), k(2), ... , k(n) with k(1) > k(2) > . . . > k(n) an L(k(1), k(2),..., k(n))-labelling of G is a function f : V(G) -> {0, 1,...} such that for every u, v is an element of V(G) and for all 1 <= i <= n, vertical bar f(u) -f(v)vertical bar >= k(i) if d(u, v) = i. The span of f is the difference between the largest and the smallest numbers in f (V(G)). The lambda k(1), k(2),..., k(n) -number of G is the minimum span over all L(k(1), k(2),..., k(n))-labellings of G. In this study, an integer linear programming model and a satisfiability test reduction for an L(k(1), k(2),..., k(n))-labelling are proposed. Both approaches are used for studying the lambda(3,2,1)-numbers of strong, Cartesian and direct products of paths and cycles.

关键词： computability graph theory integer programming linear programming satisfiability test reduction distance constrained labellings graph labellings integer linear programming model Cartesian products direct products paths cycles

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Integrated Optimization of Vehicle Scheduling and Passenger Assignment of Demand-Responsive Transit and Conventional Buses under Urban Rail Transit Disruptions

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JOURNAL OF TRANSPORTATION ENGINEERING PART A-SYSTEMS 2025年第6期151卷

作者： Jiang, Xiaona Long, Sihui Liu, Yang Meng, Fanting Luan, Xiaojie Kunming Univ Sci & Technol Sch Transportat Engn Kunming 650504 Peoples R China Beijing Union Univ Sch Coll Urban Rail Transit & Logist Beijing 100101 Peoples R China Beijing Jiaotong Univ Sch Traff & Transportat Beijing 100044 Peoples R China

Urban rail transit systems are vital to urban mobility, yet disruptions may cause significant congestion or delays for passengers. Traditional evacuation strategies, predominantly reliant on conventional buses, could not consider the diverse characteristics of passengers. This study proposes an optimization method that integrates the services of demand responsive transit (DRT) and conventional buses to efficiently and passenger-friendly evacuate stranded passengers when urban rail transit disruption occurs. An integer linear programming model is proposed to deliver both a vehicle schedule (including the number of used DRT vehicles and conventional buses, as well as the routes of the vehicles) and a passenger assignment solution simultaneously. The route of the DRT vehicle is considered variable, and passenger assignment with each vehicle depends on the passengers' destination and the route of the assigned vehicle. Moreover, we propose a preprocessing method to generate a set of feasible routes for each vehicle. We consider two objectives: maximize the number of transported passengers and minimize the travel time. An epsilon-constraint-based algorithm is used to find the Pareto optimal solutions for the proposed bi-objective model. The case study is conducted using data from a real-world urban public transportation network in China to evaluate the effectiveness of the proposed method. The experimental results show that the integrated optimization approach achieves a significant average reduction of 73.88% in travel time and 72.39% in the total number of vehicles used compared with single-mode evacuation strategies utilizing only conventional bus services. Furthermore, the experimental results obtained by integrated optimization of the vehicle route scheduling and passenger assignment achieve up to 80.93% reduction of travel time and 11.14% increase of transported passengers, compared with the solutions by fixed vehicle routes.

关键词： Urban rail transit disruption Passenger evacuation Demand responsive transit Conventional bus integer linear programming model

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Designing scheduled route for river liner shipping services with empty container repositioning

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EXPERT SYSTEMS WITH APPLICATIONS 2024年 247卷

作者： Li, De-Chang Yang, Hua-Long Dalian Maritime Univ Transportat Engn Coll Dalian 116026 Peoples R China

This paper addresses the problem of designing scheduled route for river liner shipping services with empty container repositioning. Given estimated weekly demands, the goal is to determine ports to be called and the ship schedule, while considering navigational restrictions, in order to maximize a shipping company's profit. In this decision -making process, we propose a novel integrated approach that enables the shipping company to optimize liner service routes and ship schedule simultaneously, taking into account empty container repositioning. Two mixed integer programming models, the arc -based model and the node -based model, are established to simulate this problem, and linearization techniques are applied to solve the integrated models. We prove the strict equivalence of the two models and discuss the properties of the optimal solutions. Numerical experiments based on the Yangtze River are conducted to test the applicability of these methods. We find that in the case of unsplittable demands, modeling the shipping of empty containers based on node variables significantly outperforms the approach based on arc variables in terms of computation time and accuracy. Additionally, we provide recommendations to guide the tactical decisions of liner shipping companies.

关键词： Inland waterway transportation Scheduled route design Empty container repositioning integer linear programming model Navigational restrictions

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Distribution logistics network optimization with a multi-distribution center considering carbon emission: A case study in the petrochemical industry in Thailand 6

Distribution logistics network optimization with a multi-dis...

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6th International Conference on Industry 4.0 and Smart Manufacturing, ISM 2024

作者： Chanpuypetch, Wirachchaya Kritchanchai, Duangpun Niemsakul, Sermpong Niemsakul, Jirawan Faculty of Agro-Industry Chiang Mai University Samut Sakhon74000 Thailand Department of Industrial Engineering Mahidol University Nakhon Pathom73170 Thailand Faculty of Logistics and Supply Chain Sripathum University Chonburi20000 Thailand

The study explores the optimization of the distribution network for a petrochemical business in Thailand, facing intense competition and market share loss to foreign competitors. Aiming to expand its domestic market, the business seeks to enhance its distribution network by adding a new distribution center (DC). Given the industry's environmental impact concerns, the study also focuses on reducing the environmental footprint of its supply chain and logistics activities. Despite extensive research on distribution network optimization, there remains a gap in understanding the integrated approach that simultaneously address economic efficiency, customer responsiveness, and environmental sustainability within the petrochemical sector in Thailand. This research proposes various scenarios for the distribution network, considering candidate DC locations based on current customer distributions, particularly in the Bangkok Metropolitan Area and Laem Chabang (LCB) port, along with potential hinterland arears. The analysis evaluates key performance metrics, including responsiveness, economic efficiency, and environmental impact. The findings indicate that the optimal scenario involves operating two DCs: the existing DC and a new DC in Samut Prakarn Province, significantly improving customer responsiveness. However, the results reveal that cost reduction does not directly correlate with decreased GHG emissions. The study underscores the need for businesses to define clear objectives, such as cost reduction, improved customer service, market expansion, or environmental sustainability, before redesigning distribution networks. A comprehensive evaluation of criteria, including social, opportunities, infrastructure, accessibility, resilience, and cybersecurity, is essential for informed decision-making, leading to improved cost efficiency, customer service, and operational agility. © 2025 The Authors. Published by Elsevier B.V.

关键词： Carbon emission Distribution network Environmental sustainability integer linear programming model Transportation

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Integrated optimization of charging infrastructure, fleet size and vehicle operation in shared autonomous electric vehicle system considering vehicle-to-grid

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RENEWABLE ENERGY 2024年 229卷

作者： Tian, Jingjing Jia, Hongfei Wang, Guanfeng Huang, Qiuyang Wu, Ruiyi Gao, Heyao Liu, Chao Jilin Univ Coll Transportat 5988 Renmin St Changchun 130022 Peoples R China

Shared autonomous electric vehicles (SAEVs) are predicted to become a significant solution to reduce global emissions and energy consumption resulting from urban transportation. The centralized operation of SAEVs not only allows large-scale travel demand response but also can provide essential ancillary services to the smart grid through the concept of vehicle-to-grid (V2G). With V2G technology, unused electric vehicles can work as a distributed energy storage facility for the electricity grid to smoothen the intermittent demand. Designing and operating a V2G-enabled SAEV system is challenging. This problem involves complicated planning and operational decisions, as well as time-varying electric tariffs. In this work, a flow-based integer linear programming (ILP) model is formulated for determining the optimal configurations (charging infrastructure and fleet size) and daily operation strategies (serving passengers, relocation, charging/discharging). The developed mathematical model allows for maximizing the total profit, comprising investment cost, revenue from serving passengers, and V2G profit through charging/discharging schedules. A two-stage Benders decomposition-based algorithm is proposed to address the sophisticated ILP problem. Via testing instances in the Manhattan network based on realworld and synthetic data, we have demonstrated the feasibility of our approaches and studied the benefits of integrating V2G in the SAEV system.

关键词： Shared autonomous electric vehicles Charging/discharging schedule integer linear programming model Benders decomposition -based algorithm Nomenclature

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Two-echelon vehicle routing problem with direct deliveries and access time windows

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EXPERT SYSTEMS WITH APPLICATIONS 2024年 244卷

作者： Zhou, Saiqi Zhang, Dezhi Ji, Bin Li, Shuangyan Cent South Univ Sch Traff & Transportat Engn Changsha 410075 Hunan Peoples R China Cent South Univ Forestry & Technol Coll Logist & Transportat Changsha 410004 Hunan Peoples R China

Nowadays, heavy-duty trucks are usually restricted from entering urban areas due to emission and congestion problems in most cities. So, a two-echelon distribution system becomes vastly applicable, in which satellites transfer cargo and avoid heavy-duty trucks entering urban areas. However, with the development of new energy vehicles and access policies and regulations, some environmentally friendly trucks are accessible to urban areas within specific time windows of daytime directly. In light of this, we introduce a two-echelon vehicle routing problem with direct deliveries and access time windows (2E-VRPDDATW) arising in city logistics. In this problem, customers are served by the two-echelon distribution systems within their required time windows and are allowed to be directly delivered by the first echelon vehicles within access time windows, which provides more flexible routing schemes. A novel mixed integer linear programming (MILP) model for the above problem is presented, and the corresponding adaptive large neighborhood algorithm is developed. The computational experiments are provided to verify the validity of the proposed model and the effectiveness of the algorithm. Finally, the sensitivity analysis shows some interesting findings about the number of two-echelon vehicles and the assignment of customers. Moreover, we conclude that direct deliveries are advantageous in transportation costs when the proportion of the end time of access time window to the last end time of customers is greater than 0.25.

关键词： Two-echelon vehicle routing problem Direct deliveries Access time windows integer linear programming model Adaptive large neighborhood search

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Cognitive and Time Predictable Task Scheduling in Edge-cloud Federation 27

Cognitive and Time Predictable Task Scheduling in Edge-cloud...

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IEEE 27th International Conference on Emerging Technologies and Factory Automation (ETFA)

作者： Abdi, Somayeh Ashjaei, Mohammad Mubeen, Saad Malardalen Univ Vasteras Sweden

ISBN: (数字)9781665499965

ISBN: (纸本)9781665499965

In this paper, we present a hierarchical model for time predictable task scheduling in edge-cloud computing architecture for industrial cyber-physical systems. Regarding the scheduling problem, we also investigate the common problem-solving approaches and discuss our preliminary plan to realize the proposed architecture. Furthermore, an integer linear programming (ILP) model is proposed for task scheduling problem in the cloud layer. The model considers timing and security requirements of applications and the objective is to minimize the financial cost of their execution.

关键词： Edge-Cloud federation Time predictable Task Scheduling integer linear programming model scheduling approaches

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Distribution logistics network optimization with a multi-distribution center considering carbon emission: A case study in the petrochemical industry in Thailand

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Procedia Computer Science 2025年 253卷 237-246页

作者： Wirachchaya Chanpuypetch Duangpun Kritchanchai Sermpong Niemsakul Jirawan Niemsakul Faculty of Agro-Industry Chiang Mai University Samut Sakhon 74000 Thailand Department of Industrial Engineering Mahidol University Nakhon Pathom 73170 Thailand Faculty of Logistics and Supply Chain Sripathum University Chonburi 20000 Thailand

The study explores the optimization of the distribution network for a petrochemical business in Thailand, facing intense competition and market share loss to foreign competitors. Aiming to expand its domestic market, the business seeks to enhance its distribution network by adding a new distribution center (DC). Given the industry’s environmental impact concerns, the study also focuses on reducing the environmental footprint of its supply chain and logistics activities. Despite extensive research on distribution network optimization, there remains a gap in understanding the integrated approach that simultaneously address economic efficiency, customer responsiveness, and environmental sustainability within the petrochemical sector in Thailand. This research proposes various scenarios for the distribution network, considering candidate DC locations based on current customer distributions, particularly in the Bangkok Metropolitan Area and Laem Chabang (LCB) port, along with potential hinterland arears. The analysis evaluates key performance metrics, including responsiveness, economic efficiency, and environmental impact. The findings indicate that the optimal scenario involves operating two DCs: the existing DC and a new DC in Samut Prakarn Province, significantly improving customer responsiveness. However, the results reveal that cost reduction does not directly correlate with decreased GHG emissions. The study underscores the need for businesses to define clear objectives, such as cost reduction, improved customer service, market expansion, or environmental sustainability, before redesigning distribution networks. A comprehensive evaluation of criteria, including social, opportunities, infrastructure, accessibility, resilience, and cybersecurity, is essential for informed decision-making, leading to improved cost efficiency, customer service, and operational agility.

关键词： Distribution network integer linear programming model Transportation Carbon emission Environmental sustainability

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