检索结果-内蒙古大学图书馆

Real-time customized bus routes design with optimal passenger and vehicle matching based on column generation algorithm

引用

PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2021年 571卷 125836-125836页

作者： Shen, Chan Sun, Yao Bai, Zijian Cui, Hongjun Hebei Univ Technol Sch Civil Engn & Transportat Tianjin 300401 Peoples R China Tianjin Municipal Engn Design & Res Inst Tianjin Peoples R China

With the popularity and development of mobile Internet, new transportation network services such as customized buses are expected to become a new way of popular transportation in crowded metropolises. In this paper, we propose a real-time customized bus routes design model. We divide the proposed model into two-stage problem to solve. The first stage problem is the vehicle route problem with time window (VRPTW), and the second stage problem is bilateral matching problem. For the first stage, the column generation algorithm is used to solve the problem. For the second stage, we solve it by the improved H-R bilateral matching algorithm. Finally, data on customized bus in Tianjin city of China are used to verify the accuracy of the real-time customized bus routes design model. The optimized results show that the average attendance rate has reached 70.8%, and the service rate of passenger has reached 88.5%. The results have proved that the real-time customized bus routes design model has a practical applicability in operation. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Customized bus Real-time Two-stage column generation algorithm H-R bilateral matching algorithm

来源：评论

学校读者我要写书评

暂无评论

A HYBRID column generation algorithm BASED ON METAHEURISTIC OPTIMIZATION

引用

TRANSPORT 2016年第4期31卷 389-407页

作者： Hu, Wenbin Du, Bo Wu, Ye Liang, Huangle Peng, Chao Hu, Qi Wuhan Univ Sch Comp Wuhan Hubei Province Peoples R China

The exact solution and heuristic solution have their own strengths and weaknesses on solving the Vehicle Routing Problems with Time Windows (VRPTW). This paper proposes a hybrid column generation algorithm with Metaheuristic Optimization (CGAMO) to overcome their weaknesses. Firstly, a Modified Labelling algorithm (MLA) in the sub-problem of path searching is analysed. And a search strategy in CGAMO based on the demand of sub-problem is proposed to improve the searching efficiency. While putting the paths found in the sub-problem into the main problems of CGAMO, the iterations may fall into endless loops. To avoid this problem and keep the main problems in a reasonable size, two conditions on saving the old paths in the main problem are used. These conditions enlarge the number of constraints considered in the iterations to strengthen the limits of dual variables. Through analysing the sub-problem, we can find many useless paths that have no effect on the objective function. Secondly, in order to reduce the number of useless paths and improve the efficiency, this paper proposes a heuristic optimization strategy of CGAMO for dual variables. It is supposed to accelerate the solving speed from the view of on the dual problem. Finally, extensive experiments show that CGAMO achieves a better performance than other state-of-the-art methods on solving VRPTW. The comparative experiments also present the parameters sensitivity analysis, including the different effects of MLA in the different path selection strategies, the characteristics and the applicable scopes of the two path-keeping conditions in the main problem.

关键词： vehicle routing problems with time windows column generation algorithm labelling algorithm sub-problem simplex method dual problem

来源：评论

学校读者我要写书评

暂无评论

IPTV Advertising Scheduling Methods Considering Advertising Repetition Effects

引用

IEEE TRANSACTIONS ON ENGINEERING MANAGEMENT 2024年 71卷 1585-1597页

作者： Jiang, Jingqi Luo, Xinggang Jiang, Wei Zhang, Zhongliang Northeastern Univ Sch Informat Sci & Engn Shenyang 110004 Peoples R China Hangzhou Dianzi Univ Expt Ctr Data Sci & Intelligent Decis Making Hangzhou 310018 Peoples R China Shanghai Jiao Tong Univ Antai Coll Econ & Management Shanghai 200030 Peoples R China

Internet protocol television (IPTV) advertising has the characteristics of both traditional TV and online advertising and mainly sells impressions through signed guaranteed contracts with advertisers. In this study, we applied the reach and frequency (R&F) contract to the IPTV sales model. Through the R&F contract, advertisers can specify the expected number of unique individuals reached and the frequency cap of the advertisements seen by each user. Considering the lack of user demographic information, we propose using viewing program information instead as the basis for user classification in targeted advertising. Advertising allocation models for two-layer optimization are established. In the upper layer optimization, the advertising allocation proportion is optimized for all user types to minimize the publisher's under-delivery and nonrepresentativeness of advertising delivery among user types. In the lower layer optimization, the impact of repeated advertising on user purchase probability is considered. The specific allocation of advertisements is optimized for each user type to maximize the expected number of buyers without violating the optimization results of the upper layer optimization. A repeated exposure-based hierarchical column generation (REHCG) algorithm is used to address the IPTV advertising scheduling problem. Numerical experiments based on actual data from the IPTV industry show that the REHCG algorithm obtains high-quality results for IPTV advertising scheduling.

关键词： Advertising repetition column generation algorithm Internet protocol television (IPTV) advertising targeted advertising

来源：评论

学校读者我要写书评

暂无评论

Urban rail-bus-walk network service integration towards accessibility and heat exposure consideration: Models and column generation solution approaches

引用

TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES 2024年 165卷

作者： Huang, Xianting Wei, He Zhang, Xiaodong Tong, Lu (Carol) Carnegie Mellon Univ Pittsburgh PA 15213 USA Beijing Municipal Inst City Planning & Design Beijing 100045 Peoples R China Beihang Univ Sch Elect Informat Engn Beijing 100191 Peoples R China State Key Lab CNS ATM Beijing 100191 Peoples R China

The evolution of urban transportation systems is increasingly driven by the integration of rail, bus, and walking pathways, forming a cohesive service network. This urban rail-bus-walk service network integration is pivotal in addressing urban challenges and ensuring seamless mobility. Nevertheless, the effectiveness of such integrated systems depends on their accessibility and the willingness of individuals to take them as their primary transportation mode. In the context of climate change, extreme heat events pose an increasing threat to passenger comfort and health, which in turn, affects individuals' decisions to use public transit. Additionally, walking to transit stops or waiting for transportation becomes more challenging during such extreme heat conditions. This paper tackles the challenge of comprehensively addressing the evolving issues related to public transit accessibility in response to rising temperatures, an area of research that has received limited attention until now. This paper introduced an approach aimed at optimizing the urban rail-bus-walk service network with a focus on both accessibility and heat exposure considerations. By calculating the transportation accessibility level under varying temperature conditions and identifying its vulnerability to high temperatures, this paper presents a methodology to enhance the transit service. Such improvement involves not only adjustments to the integration network but also considering of cooling facilities, such as shaded routes and shelters. column generation is applied to solve this problem and the optimization result demonstrates improvement of accessibility under the extreme heat condition.

关键词： Multi -modal transportation system Accessibility Heat exposure column generation algorithm

来源：评论

学校读者我要写书评

暂无评论

Slot co-chartering and capacity deployment optimization of liner alliances in containerized maritime logistics industry

引用

ADVANCED ENGINEERING INFORMATICS 2023年第1期56卷

作者： Chen, Jihong Xu, Jianghao Zhou, Shaorui Liu, Anti Shenzhen Univ Coll Civil & Transportat Engn Shenzhen 518060 Peoples R China Shenzhen Univ Coll Management Shenzhen 518073 Peoples R China Shenzhen Int Maritime Inst Shenzhen 518081 Peoples R China Sun Yat Sen Univ Sch Intelligent Syst Engn Guangzhou 510275 Peoples R China

With the growing traffic of containerized shipping worldwide, container liners have seen increasing cooperation. Slot co-chartering has drawn wide attention as a way of cooperation within liner alliances. However, liners face the issue of finding proper measures to optimize alliance operations. In response to this, this paper compre-hensively considers shipping capacity dispatch for containerized shipping companies within liner alliances. First, we explained the general rules of liner shipping dispatch and analyzed the interfering factors. Second, we created a liner shipping capacity dispatch model without consideration of slot co-chartering costs and a liner shipping capacity dispatch model with consideration of slot co-chartering costs and proposed a new column generation algorithm to solve both problems. Third, we tested our algorithm in a real case of a large Chinese containerized shipping company, which belongs to Ocean Alliance, and an optimal ship dispatch strategy on relevant routes and a decision on optimal slot chartering can be reached. Computational results indicate that the proposed column generation algorithm exhibits effective and efficient performance for large-scale slot co-chartering in liner shipping.

关键词： Maritime logistics Liner alliance Slot co-chartering column generation algorithm

来源：评论

学校读者我要写书评

暂无评论

Four-dimensional computed tomography-based ventilation imaging in intensity-modulated radiation therapy treatment planning for pulmonary functional avoidance

引用

JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS 2023年第6期24卷 e13920页

作者： Iqbal, Gazi Md Daud Zhang, Hao D'Souza, Wareen Ha, Lidan Rosenberger, Jay M. Coppin State Univ Coll Business Baltimore MD 21216 USA Univ Maryland Med Syst Linthicum MD USA Univ Texas Arlington Ind Mfg & Syst Engn Arlington TX USA

PurposeTo incorporate four-dimensional computed tomography (4DCT)-based ventilation imaging into intensity-modulated radiation therapy (IMRT) treatment planning for pulmonary functional avoidance. Methods and MaterialsNineteen locally advanced lung cancer patients are retrospectively studied. 4DCT images are employed to create ventilation maps for each patient via a density-change-based algorithm with mass correction. The regional ventilation is directly incorporated into the mathematical formulation of a direct aperture optimization model in IMRT treatment planning to achieve functional avoidance and a voxel-based treatment plan. The proposed functional avoidance planning and voxel-based planning are compared to the conventional treatment planning approach purely based on the anatomy of patients. Paired sample t-tests are conducted to see whether dosimetric differences among the three approaches are significant. ResultsSimilar planning target volume (PTV) coverage is achieved by anatomical, functional avoidance, and voxel-based approaches. The voxel-based treatment planning performs better than both functional avoidance and anatomical planning to the lung. For a total lung, the average volume reductions in a functional avoidance plan from an anatomical plan, a voxel-based plan from an anatomical plan, and a voxel-based plan from a functional avoidance plan are 7.0% , 16.8%, and 10.6%, respectively for V-40;and 0.4%, 6.4%, and 6.0%, respectively for mean Lung Dose (MLD). For a functional lung, the reductions are 8.8% , 17.2%, and 9.2%, respectively, for fV(40);and 1.1%, 6.2%, and 5.2%, respectively, for functional mean lung dose (fMLD). These reductions are obtained without significantly increasing doses to other organs-at-risk. All the pairwise treatment planning comparisons for both total lung and functional lung are statistically significant (p-value

关键词： voxel based treatment column generation algorithm lung cancer optimization

来源：评论

学校读者我要写书评

暂无评论

Hierarchical two-stage robust optimisation dispatch based on co-evolutionary theory for multiple CCHP microgrids

引用

IET RENEWABLE POWER generation 2020年第19期14卷 4121-4131页

作者： Tan, Bifei Chen, Haoyong Zheng, Xiaodong South China Univ Technol Sch Elect Power Engn Guangzhou 510641 Guangdong Peoples R China

Combined cooling, heating, and power (CCHP) microgrids are a special form of a microgrid that is attracting increasing attention. This study contributes to the goal of minimising the operation cost of CCHP microgrids by proposing a hierarchical two-stage robust optimisation dispatch model for multiple CCHP microgrid systems. The uncertainties associated with wind power output, electric power, heating, and cooling loads, and transmission line failures are considered in the proposed model. Moreover, the electricity purchasing and selling prices of each microgrid are independently determined. The proposed model applies the outputs of fuel cells, energy storage devices, and gas turbines, the distribution factor of waste heat, and the power transmission between the microgrids and an external grid as control variables. The optimised dispatch problem is solved using McCormick envelopes relaxation and a novel column and constraint generation algorithm that provides enhanced optimisation performance by implementing co-evolutionary theory. In this way, the microgrid system is divided into several sections, and each section is represented as an individual min-max-min problem. The rationality and validity of the proposed model and the superiority of the solution performance of the improved algorithm are verified through simulation case studies involving a system composed of four CCHP microgrids.

关键词： power generation economics gas turbines power generation control wind power plants cogeneration distributed power generation minimax techniques power generation dispatch fuel cells power transmission co-evolutionary theory two-stage robust optimisation dispatch model multiple CCHP microgrid systems wind power output electric power cooling loads transmission line failures waste heat power transmission optimised dispatch problem enhanced optimisation performance hierarchical robust optimisation dispatch combined cooling-heating-power microgrids electricity purchasing fuel cells energy storage devices gas turbines distribution factor McCormick envelopes relaxation column generation algorithm constraint generation algorithm min-max-min problem

来源：评论

学校读者我要写书评

暂无评论

Adaptive uncertainty sets-based two-stage robust optimisation for economic dispatch of microgrid with demand response

引用

IET RENEWABLE POWER generation 2020年第18期14卷 3608-3615页

作者： Qiu, Yibin Li, Qi Huang, Lanjia Sun, Cai Wang, Tianhong Chen, Weirong Southwest Jiaotong Univ Sch Elect Engn Chengdu 611756 Peoples R China

It is an effective way to regard the electric vehicles as the demand response for reducing the negative impact of large-scale introduction on the power system. Aiming at the microgrid with demand response, the adaptive uncertainty sets-based two-stage robust optimisation method is established in this study. The coordination of micro-gas turbine, energy storage, and demand response etc. are considered in the economic dispatch model. To effectively consider the uncertain variable contained in the microgrid, the concept of adaptive uncertainty sets is proposed in this study. The uncertainty sets are achieved by the long short-term memory network and modified fuzzy information granulation. To handle the adaptive uncertainty sets-based robust optimisation model, the column and constraint generation algorithm and strong duality theory are introduced to decompose the model into a master problem and a subproblem with mixed-integer linear structure. To verify the performance of the proposed adaptive uncertainty sets-based two-stage robust optimisation method, measured data from a plateau city of China are introduced in the simulation test. The simulation results demonstrate the effectiveness of the model and solution strategy.

关键词： duality (mathematics) fuzzy set theory linear programming distributed power generation power generation dispatch gas turbines integer programming power generation economics demand side management recurrent neural nets power engineering computing electric vehicles energy storage demand response robust optimisation model adaptive uncertainty sets-based two-stage robust optimisation method electric vehicles economic dispatch model power system microgrid microgas turbine coordination energy storage long short-term memory network modified fuzzy information granulation constraint generation algorithm column generation algorithm strong duality theory mixed-integer linear structure simulation test

来源：评论

学校读者我要写书评

暂无评论

Planning of guaranteed IPTV advertising considering advertising effectiveness

Planning of guaranteed IPTV advertising considering advertis...

引用

第34届中国控制与决策会议

作者： Jingqi Jiang Xinggang Luo Yang Yu School of Information Science and Engineering Northeastern University School of Management Hangzhou Dianzi University

In recent years,the online advertising industry has developed *** scholars have carried out research on how to formulate an optimal advertising ***,in the process of advertising,too redundant advertising often causes customers' ***,it is necessary to ensure that the number of advertisements assigned by each user is within a reasonable range to maximize advertising *** the background of IPTV guaranteed contract,this paper studies the advertising planning problem considering the advertising effect caused by repeated *** order to solve this large-scale linear programming problem,an approach based on column generation algorithm is presented in this ***,experiment based on actual case shows the effectiveness of the algorithm.

关键词： IPTV advertising advertising effectiveness column generation algorithm

来源：评论

学校读者我要写书评

暂无评论

Green scheduling model of shuttle tanker fleet considering carbon tax and variable speed factor

引用

JOURNAL OF CLEANER PRODUCTION 2019年 234卷 1134-1143页

作者： Xin, Xu Wang, Xiaoli Tian, Xuecheng Chen, Zigen Chen, Kang Tongji Univ Sch Econ & Management Shanghai 200092 Peoples R China Wuhan Univ Sch Econ & Management Wuhan 430072 Hubei Peoples R China Dalian Maritime Univ Transportat Engn Coll Dalian 116026 Liaoning Peoples R China Dalian Maritime Univ Sch Shipping Econ & Management Dalian 116026 Liaoning Peoples R China

Green scheduling is an important means to achieve sustainable industrial development and enhance the green efficiency of enterprises. Given the characteristics of a modern crude oil supply system, the shuttle tanker fleet green scheduling problem (FGSP) is discussed considering a carbon tax and variable tanker speed factor. To minimize the green operating cost (i.e., sum of general operating cost and carbon tax) of the tanker fleet, an integer programming model for shuttle tanker fleet green scheduling (FGSM) is established. The FGSM optimizes the number and sizes of tankers, the number and positions of floating production storage and offloading units (FPSO) at which to berth and the scheduling plan (i.e., berthing order and sailing speed) of each tanker in the fleet. Based on the column generation algorithm, a shuttle tanker fleet green scheduling algorithm is designed to solve the above model accurately. The experimental results show that considering the speed factor, the green operating cost of an example fleet decreases. For different carbon tax rates, speed optimization is an effective way to reduce the green operating cost of the fleet. The above results also show that the FGSM and algorithm can effectively solve the FGSP, improve the operation level and efficiency, and reduce the green operating cost of oil companies. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Shuttle tanker Ship scheduling Green scheduling Carbon tax Vessel speed column generation algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：