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Long term simulation analysis of deceased donor initiated chains in kidney exchange programs

HEALTH SYSTEMS 2024年第2期13卷 121-132页

作者： Verma, Utkarsh Rangaraj, Nayaran Billa, Viswanath Usulumarty, Deepa Indian Inst Technol Dept Ind Engn & Operat Res Mumbai India Bombay Hosp & Med Res Ctr Dept Nephrol Mumbai India Apex Kidney Fdn Apex Swap Transplant Registry Mumbai India Sushrut Hosp Dept Nephrol Apex Kidney Care Mumbai India

Kidney exchange programs (KEPs) aim to find compatible kidneys for recipients with incompatible donors. Patients without a living donor depend upon deceased donor (DD) donations to get a kidney transplant. In India, a (c) DD donates kidneys directly to a (c) DD wait-list. The idea of initiating an exchange chain starting from a (c) DD kidney is proposed in a few articles (and executed in Italy in 2018), but no mathematical formulation has been given for this merger. We have introduced an integer programming formulation that creates (c) DD-initiated chains, considering both paired exchange registry and (c) DD allocations simultaneously and addressing the overlap issue between the exchange registry and (c) DD wait-list as recipients can register for both registries independently. A long-term simulation study is done to (c) analyse the gain of these DD-initiated chains over time. It suggests that even with small numbers of (c) DDs, these chains can significantly increase potential transplants.

关键词： Health care management kidney exchange program deceased donor allocation integer programming model simulation

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A novel adjustable defragmentation algorithm in elastic optical networks

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OPTICAL FIBER TECHNOLOGY 2024年 82卷

作者： Khorasani, Yaghoub Rahbar, Akbar Ghaffarpour Alizadeh, Behrooz Sahand Univ Technol Fac Elect Engn Comp Networks Lab Tabriz Iran Shahid Sattari Univ Aeronaut Engn Dept Elect Engn Tehran Iran Sahand Univ Technol Dept Appl Math Tabriz Iran

Fragmentation is one of the challenges in elastic optical networks (EONs), and therefore, solutions to deal with this challenge are important. Defragmentation is one of the reactive methods that is used after the occurrence of fragmentation. Defragmentation reduces fragmentation by rerouting and re-establishing some existing connections. Fragmentation directly affects the demand blocking probability (DBP) and improves bandwidth efficiency. However, a large number of re-routings may decrease the quality of service. The starting time of the defragmentation algorithm for execution is also of great importance. In this article, a new algorithm is presented for defragmentation, called Adjustable Defragmentation (Adj-Defrag). In Adj-Defrag, the fragmentation problem in the network is defined as an integer nonlinear programming model based on the Golden metric, and then the desired items are determined optimally based on a heuristic algorithm and a meta-heuristic solution. This algorithm is compared with different and the results of the performance evaluation demonstrate its effectiveness in improving various network performance parameters.

关键词： EON defragmentation Re-routing integer programming model

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Optimal route planning for day tours in Marinduque, Philippines

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SPATIAL INFORMATION RESEARCH 2022年第2期30卷 205-214页

作者： Lutero, Destiny S. Cerilo, Gilbert Elvis A. Eustaquio, Allyssa M. Buhat, Christian Alvin H. Nazareno, Aldrin O. Nazareno, Allen L. Salvacion, Arnold R. Univ Philippines Los Banos Coll Arts & Sci Inst Math Sci & Phys Victoria M Ela St Los Banos 4031 Laguna Philippines Univ Houston Houston TX 77204 USA Buenavista Natl High Sch Bagacay Annex Buenavista 4904 Marinduque Philippines Univ Philippines Los Banos Coll Human Ecol Dept Community & Environm Resource Planning Harold Cuzner Royal Palm Ave Los Banos 4031 Laguna Philippines

Island day tours have become a ubiquitous inclusion in travel itineraries. Marinduque is one of the Philippine islands where its major tourist attractions can be covered by day tours. This study determines an itinerary of select tourist spots for island day tours in Marinduque. The longitude, latitude of each tourist spot and the pairwise road distances were determined. Every tour was assumed to start and end at the same point, either at Marinduque Airport or at Balanacan Port, and would last for at most 8 h. To determine the optimal route for the different types of tours (general and themed), an integer programming model was formulated. Balanacan port is the point of origin for three of the four identified tours. The general tour is the ideal choice for those who want to maximize theme diversity. The history-themed and church-themed tours are covered in at least three of the four tours. All tours ran from 7.5 to 8 h. All themed-tours covered their themed points except for the cave-themed. All points except one were visited in at least one tour. Three of the four pilgrim points were visited in all tours, while the cave sites were only visited in the cave-themed tour. The results of this study are beneficial to the community of Marinduque, as these will contribute to the tourism management plan of the province. The model may be extended to consider other tourist destinations.

关键词： Travel itinerary Traveling salesman problem Tourism Tour time integer programming model

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Research on task distribution of maritime emergency disposal based on Vogel method 34

Research on task distribution of maritime emergency disposal...

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34th Chinese Control and Decision Conference (CCDC)

作者： Mao, Jiahui Guo, Yu Wang, Xingliang Gao, Yingying Yang, Qingqing Yang, Kewei Natl Univ Def Technol Coll Syst Engn Changsha 410073 Peoples R China

ISBN: (纸本)9781665478960

The task distribution of joint emergency disposal for maritime emergencies is an important link to improve the efficiency of joint emergency disposal for maritime emergencies, which involves tasks such as traffic organization, rescue and pollution removal, as well as the close cooperation of multi organizations and social forces such as marine police, maritime affairs, environmental protection and fishery, so as to realize the rapid distribution of tasks, tasks should be reasonably allocated to various organizations to achieve a clear division of labor. By analyzing the actual process of joint emergency disposal of maritime emergencies, this paper abstracts the problem as an integer programming problem of multi-stage decision-making. Firstly, decompose and sort out the joint emergency disposal tasks of maritime emergencies, determine the time sequence relationship between tasks, and construct a multi-stage task network diagram;Then, the organizational task network model is established, and the model implementation idea based on Vogel method is proposed;Finally, an example is calculated based on the scoring data given by the experts who actually participate in the disposal business, and compared with the actual situation of the accident at that time. The effectiveness of the model and algorithm in this paper is illustrated by the real "Sangji ship" accident case.

关键词： Joint emergency disposal of maritime emergencies Task distribution Vogel method Task network integer programming model

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Optimal decision of multiobjective and multiperiod anticipatory shipping under uncertain demand: A data-driven framework

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COMPUTERS & INDUSTRIAL ENGINEERING 2021年 159卷 107445-107445页

作者： Chen, Cheng Xu, Xianhao Zou, Bipan Peng, Hongxia Li, Zhiwen Huazhong Univ Sci & Technol Sch Management Wuhan 430074 Peoples R China Zhongnan Univ Econ & Law Sch Business Adm Wuhan 430074 Peoples R China Hubei Univ Sch Business Wuhan 430062 Peoples R China

Anticipatory shipping helps to reduce the waiting time of online customers to receive their products. Present studies on anticipatory shipping mainly consider a single period and ignore the waiting time saved for customers. This paper develops a data-driven framework to investigate the multiperiod anticipatory shipping problem with the objectives of minimizing the cost of online retailers and maximizing the saved waiting time of customers. First, we propose a dual-process sales forecasting framework that employs five machine learning algorithms to forecast online retailers' daily sales using clickstream data and historical sales data. Then, we build a multiperiod and multiobjective integer programming model based on the forecasting sales and forecasting errors to explore the optimal quantity and time of products of anticipatory shipping. Finally, using TOPSIS, Shannon entropy, and LINMAP decision-making methods, the final optimal solution is selected from the Pareto set obtained by the NSGA-II algorithm. The case study results show that anticipatory shipping saves 5.96% cost for the online retailer and 1.69 days of waiting time on average for the customer compared with non-anticipatory shipping. Moreover, performing anticipatory shipping is especially beneficial in the case of high inventory holding cost, large distribution center capacity, and long transportation duration.

关键词： Anticipatory shipping Multiobjective Data-driven integer programming model Online retail

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Rebalancing stochastic demands for bike-sharing networks with multi-scenario characteristics

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INFORMATION SCIENCES 2021年 554卷 177-197页

作者： Ma, Guanhua Zhang, Bowen Shang, Changjing Shen, Qiang Beijing Inst Technol Sch Management & Econ Beijing 100081 Peoples R China Beijing Univ Chem Technol Sch Econ & Management Beijing 100029 Peoples R China Aberystwyth Univ Dept Comp Sci Aberystwyth SY23 3DB Dyfed Wales

Bike-sharing networks have become a carbon-emission and environmentally friendly form of transportation in recent years. However, the asymmetric demand patterns of user behaviour, both temporally and spatially, inevitably lead to an imbalance in the distribution of shared bikes in cities, thereby becoming the greatest obstacle to the networks' development. Based on the real-world data of cycling trips, we analyse the challenging problem of imbalanced bike distribution from the entire-city perspective, establishing that the static rebalancing demand for the whole city is a stochastic variable with multi-scenario characteristics. On this basis, we develop an integer programming model to consider multiple rebalancing vehicles with time-varying rental costs, to alleviate the imbalanced bike distribution, while also analysing the intrinsic properties of such a model. We further propose a chance constraint programming model, optimising a bike-sharing network through the implementation of various genetic algorithms that employ block crossover and variable mutation operators. We reveal the inability of deterministic models in addressing the real-world problem of rebalancing demands for operational bike-sharing. In the meantime, supported with stochastic simulation, we demonstrate that the proposed approach can resolve this problem both effectively and efficiently, ensuring the delivery of a high-level bike-sharing service across an entire metropolitan city. (C) 2020 Elsevier Inc. All rights reserved.

关键词： Bike sharing network Static rebalancing operations integer programming model Genetic algorithms

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The optimal 5G base station location of the wireless sensor network considering timely reliability

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RELIABILITY ENGINEERING & SYSTEM SAFETY 2023年第1期236卷

作者： Wang, Ning Xiao, Yiyong Tian, Tianzi Yang, Jun Beihang Univ Sch Reliabil & Syst Engn Beijing 100191 Peoples R China

To ensure the timely reliability of the data packets transmitted in the intelligent Internet of Things, many 5 G base stations must be established as relay nodes. Thus, how to meet the transmission requirements with the minimum building cost has become an urgent problem. The existing studies abstract this problem into a network design problem with relays (NDPR). However, these studies only focus on whether all target areas can be covered, and ignore timely reliability. Secondly, they use the number of hops to measure the transmission delay and ignore the actual transmission process. Therefore, to solve the above problems, we study the 5 G base station optimization location model considering timely reliability. Firstly, combining the definition of network reliability and the law of large numbers, we establish the timely reliability model, and transform it into a mixed integer linear programming (MILP) model. Secondly, considering the transmission process, we propose a novel NDPR model to optimize the base station location and propose a partial optimization algorithm to solve the large-scale case. Besides, taking the smart grid as an example, the validity of the proposed method is verified. Finally, the sensitivity analysis is carried out to provide corresponding suggestions for reducing the building cost.

关键词： Wireless sensor network 5 G base station location Timely reliability integer programming model Network design problem with relays Partial optimization algorithm

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The road to electrification: Bus fleet replacement strategies

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APPLIED ENERGY 2023年第1期337卷

作者： Zhou, Yu Ong, Ghim Ping Meng, Qiang Natl Univ Singapore Dept Civil & Environm Engn Singapore 117576 Singapore

The public transport market in most global cities is dominated by diesel buses, which can have significant adverse impacts on the environment and human health. To reach carbon neutrality, many public transport operators are attempting to replace their existing bus fleets with electric buses (EBs). This paper develops a generic bus replacement model to help public transit (PT) operators progressively renew their existing bus fleets so as to reach particular electrification goals within a given planning horizon. Unlike existing studies, our model more comprehensively considers the external costs, which include external climate costs, external health costs and used battery recycling costs/profits. Furthermore, by incorporating different incentives, variants on the model can be adopted to investigate how different government incentives can affect the replacement behaviors of PT operators. Finally, our proposed approach is applied to real-world data from a bus operator in Singapore which is aiming to achieve a 100% cleaner energy bus fleet within 20 years. The experiments indicate that an EB subsidy can effectively accelerate the electrification process, and a 25% EB subsidy could achieve full electri-fication eight years earlier than if no EB subsidy were applied. Moreover, we explore how the diesel tax and diesel bus (DB) tax affect EB replacement. Our experiments suggest a 10% diesel tax rate can achieve good results but imposing a DB tax will not encourage PT operators to purchase EBs earlier.

关键词： Electric bus Bus replacement Electrification Emission reduction integer programming model

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Study on Crop Planting Strategies for Rural Areas in North China Based on Multi-model Optimization 24

Study on Crop Planting Strategies for Rural Areas in North C...

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Proceedings of the 2024 4th International Conference on Computational modeling, Simulation and Data Analysis

作者： Heli Wan Shixiong Jiang Jialin Lv Yujie Zhang School of Information Science and Engineering Dalian Polytechnic University Dalian Liaoning China Department of Basic Teaching Dalian Polytechnic University Dalian Liaoning China

ISBN: (纸本)9798400711831

This paper focuses on a rural area in North China, aiming to promote the development of organic crop cultivation and achieve sustainable economic development. Based on the data analysis of organic crop cultivation in 2023, an integer programming model is constructed to deal with the situation of excess production and improve the utilization of land space. A multi-objective planning model is established using the NSGA-II algorithm to predict the seasonal planting schemes for 2024-2030. Then, the Hausdorff distance algorithm is used in combination with the K-means++ clustering method to explore the correlation between crop characteristics and indicators. Finally, Monte Carlo simulation is used to enhance adaptability, and the simulation and solution verification show that the first crop planting should be concentrated on grain crops, while the planting of legumes should be reduced. The second crop planting structure should be inclined towards edible fungi crops, and the crop varieties will be more diversified. These results provide a scientific planting strategy for the rural area, which can effectively promote the rural area to achieve the goal of maximizing economic benefits. It also provides valuable reference for subsequent research and practice.

关键词： integer programming model

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A multi-tiered vehicle routing problem with global cross-docking

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COMPUTERS & OPERATIONS RESEARCH 2022年 137卷 105526-105526页

作者： Smith, A. Toth, P. Bam, L. van Vuuren, J. H. Stellenbosch Univ Dept Ind Engn Stellenbosch Unit Operat Res Engn Private Bag X1 ZA-7602 Matieland South Africa Univ Bologna DEI Viale Risorgimento 2 I-40136 Bologna Italy Dept Ind Engn Hlth Syst Engn & Innovat Hub Private Bag X1 ZA-7602 Matieland South Africa

A new "rich"variation on the multi-objective vehicle routing problem (VRP), called the multi-tiered vehicle routing problem with global cross-docking (MTVRPGC), is introduced in this paper. With respect to previously studied VRPs, the MVRPTGC includes the following novel features: (i) segregation of facilities into different tiers that distinguish them in terms of different processing and storage capabilities, (ii) cross-docking at a pre-specified subset of facilities in the network (a feature referred to as global cross-docking), and (iii) the possibility of spillover into subsequent planning periods of demand for facility visitation. The problem originated from a real-life application concerning the collection and delivery of pathology specimens in the transportation network of a pathology health-care service provider. Other industrial applications may, however, benefit from this type of VRP, such as mail sorting. A mixed integer linear programming (MILP) model for this VRP is proposed, and tested computationally in respect of seventeen small hypothetical test instances. A multi-objective ant colony optimisation (MACO) algorithm for solving larger real-world instances of the MTVRPGC is also proposed. The solutions returned by the MACO algorithm are compared with those achieved by the MILP in respect to sixteen instances and also compared to actual collection and delivery routes of a real pathology healthcare service provider operating in South Africa and it is found that adopting the routes suggested by the algorithm results in substantial improvements of all the objectives pursued relative to the status quo.

关键词： Combinatorial optimisation Vehicle routing problem integer programming model Global cross-docking Multi-objective ant colony optimisation Healthcare optimisation Supply chain management

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