scholarly journals Optimizing Vehicle Scheduling Based on Variable Timetable by Benders-and-Price Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Zekang Lan ◽  
Shiwei He ◽  
Rui Song ◽  
Sijia Hao
Keyword(s):  
Numerical Experiments ◽  
Large Scale ◽  
Benders Decomposition ◽  
Vehicle Scheduling ◽  
Scheduling Problem ◽  
Fleet Size ◽  
Optimization Software ◽  
Price Approach ◽  
Price Algorithm

In practice, vehicle scheduling is planned on a variable timetable so that the departure times of trips can be shifted in tolerable ranges, rather than on a fixed timetable, to decrease the required fleet size. This paper investigates the vehicle scheduling problem on a variable timetable with the constraint that each vehicle can perform limited trips. Since the connection-based model is difficult to solve by optimization software for a medium-scale or large-scale instance, a designed path-based model is developed. A Benders-and-Price algorithm by combining the Benders decomposition and column generation is proposed to solve the LP-relaxation of the path-based model, and a bespoke Branch-and-Price is used to obtain the integer solution. Numerical experiments indicate that a variable timetable approach can reduce the required fleet size with a tolerable timetable deviation in comparison with a fixed timetable approach. Moreover, the proposed algorithm is greatly superior to GUROBI in terms of computational efficiency and guarantees the quality of the solution.

Job-Shop Scheduling Approach to Order-Picking Problem

2012 ◽  
Author(s):  
Yukiyasu Iwasaki ◽  
Ikuo Suzuki ◽  
Masahito Yamamoto ◽  
Masashi Furukawa
Keyword(s):  
Numerical Experiments ◽  
Large Scale ◽  
Job Shop ◽  
Job Shop Scheduling ◽  
Order Picking ◽  
Scheduling Problem ◽  
Mail Order ◽  
Job Shop Scheduling Problem ◽  
Rule Based ◽  
Shop Scheduling

In recent years, a large-scale logistic center plays an important role in mail-order business with Internet. In the logistic center, the efficient managing is required to deliver products to customers as soon as possible. Researches to efficiently control the logistic center have been done in the various approaches. This study proposed a new method for the order-picking problem considering worker’s jamming at the same shelf in the logistic center. In the proposed method, we formulate worker’s scheduling in the logistic center as Job-shop Scheduling Problem and optimize this problem. Numerical experiments show the proposed method improve worker’s scheduling compared with rule-based scheduling.

scholarly journals Solving a Large-Scale Multi-Depot Vehicle Scheduling Problem in Urban Bus Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaomei Xu ◽  
Zhirui Ye ◽  
Jin Li ◽  
Chao Wang
Keyword(s):  
Large Scale ◽  
Real Life ◽  
Set Partitioning ◽  
Vehicle Scheduling ◽  
Computational Time ◽  
Neighborhood Search ◽  
Scheduling Problem ◽  
Solution Quality ◽  
Time Space ◽  
Improved Model

This study proposes an improved model and algorithm for the large-scale multi-depot vehicle scheduling problem (MDVSP) with departure-duration restrictions. In this study, the time-space network is applied to model the large-scale MDVSP. Considering that crews usually change shifts in the depot, departure-duration restrictions are added to the classic set-partitioning model to ensure that buses return to the depot when crews reach their working time limits. By embedding a preliminary exploring tactic to the shortest path faster algorithm (SPFA), researchers developed an improved large neighborhood search (LNS) algorithm to solve large-scale instances of MDVSP with departure-duration restrictions. The proposed methodology is applied to a real-life case in China and several test instances. The results show that the improved LNS algorithm can achieve very good performance in computational efficiency without deteriorating solution quality, which is important for large-scale systems. More specifically, the total cost of the improved LNS algorithm is approximately equal to branch-and-price, but the computational time is much shorter in the case study. For test instances with different number of timetabled trips (500, 1000, 1500, and 2000), the Quality Gap (QG) is very small, approximately 0.35%, 0.38%, 0.63%, and 0.93%, while the Efficiency Ratio (ER) reaches up to 2.89, 2.98, 3.65, and 3.79, respectively.

Research on MPI-Based Parallel Max-Min Ant System

2012 ◽  
Vol 198-199 ◽  
pp. 1321-1326 ◽  
Author(s):  
Yu Liu ◽  
Guo Dong Wu
Keyword(s):  
Combinatorial Optimization ◽  
Numerical Experiments ◽  
Large Scale ◽  
Optimization Problems ◽  
Computation Time ◽  
Traveling Salesman ◽  
Ant System ◽  
Combinatorial Optimization Problems ◽  
The Traveling Salesman Problem

When solving large scale combinatorial optimization problems, Max-Min Ant System requires long computation time. MPI-based Parallel Max-Min Ant System described in this paper can ensure the quality of the solution, as well as reduce the computation time. Numerical experiments on the multi-node cluster system show that when solving the traveling salesman problem, MPI-based Parallel Max-Min Ant System can get better computational efficiency.

scholarly journals Research on the Scheduling Problem of Movie Scenes

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yulian Liu ◽  
Qiuji Sun ◽  
Xiaotian Zhang ◽  
Yiwei Wu
Keyword(s):  
Numerical Experiments ◽  
Large Scale ◽  
Programming Model ◽  
Small Scale ◽  
Scheduling Problem ◽  
Swarm Optimization ◽  
Integer Linear Programming Model ◽  
Factors Affecting ◽  
Total Cost ◽  
The Cost

The scheduling problem of movie scenes refers to the reasonable ordering of the shooting sequence of the scene, thereby minimizing the total cost of the movie scenes. This paper considers the factors affecting the cost of movie scenes shooting in the real world and constructs an integer linear programming model. A tabu search based method (TSBM) and a particle swarm optimization based method (PSOBM) are designed to solve larger-scale problems. Numerical experiments show that both TSBM and PSOBM are suitable for solving small-scale movie scenes scheduling problem. Moreover, through the comparison experiments between TSBM and PSOBM, it is verified that the TSBM can effectively solve the large-scale movie scenes scheduling problem.

Assessment of quality of life in patients with the effects of transient ischemic stroke

2016 ◽  
pp. 37-39
Author(s):  
A. Babirad
Keyword(s):  
Quality Of Life ◽  
Ischemic Stroke ◽  
Large Scale ◽  
Cerebrovascular Diseases ◽  
Control Measures ◽  
Sociological Research ◽  
Cerebrovascular Events ◽  
Sf 36 ◽  
Angioplasty And Stenting

Cerebrovascular diseases are a problem of the world today, and according to the forecast, the problem of the near future arises. The main risk factors for the development of ischemic disorders of the cerebral circulation include oblique and aging, arterial hypertension, smoking, diabetes mellitus and heart disease. An effective strategy for the prevention of cerebrovascular events is based on the implementation of large-scale risk control measures, including the use of antiagregant and anticoagulant therapy, invasive interventions such as atheromectomy, angioplasty and stenting. In this connection, the efforts of neurologists, cardiologists, angiosurgery, endocrinologists and other specialists are the basis for achieving an acceptable clinical outcome. A review of the SF-36 method for assessing the quality of life in patients with the effects of transient ischemic stroke is presented. The assessment of quality of life is recognized in world medical practice and research, an indicator that is also used to assess the quality of the health system and in general sociological research.

Model and Method for Contributor’s Quality Assessment in Community Image Tagging Systems

2018 ◽  
pp. 45-51
Author(s):  
A. V. Ponomarev
Keyword(s):  
Large Scale ◽  
Wide Spectrum ◽  
Preference Relation ◽  
Pairwise Comparison ◽  
Ground Truth ◽  
Comparison Method ◽  
Characteristic Matrix ◽  
Image Tagging ◽  
Proposed Model

Introduction: Large-scale human-computer systems involving people of various skills and motivation into the information processing process are currently used in a wide spectrum of applications. An acute problem in such systems is assessing the expected quality of each contributor; for example, in order to penalize incompetent or inaccurate ones and to promote diligent ones.Purpose: To develop a method of assessing the expected contributor’s quality in community tagging systems. This method should only use generally unreliable and incomplete information provided by contributors (with ground truth tags unknown).Results:A mathematical model is proposed for community image tagging (including the model of a contributor), along with a method of assessing the expected contributor’s quality. The method is based on comparing tag sets provided by different contributors for the same images, being a modification of pairwise comparison method with preference relation replaced by a special domination characteristic. Expected contributors’ quality is evaluated as a positive eigenvector of a pairwise domination characteristic matrix. Community tagging simulation has confirmed that the proposed method allows you to adequately estimate the expected quality of community tagging system contributors (provided that the contributors' behavior fits the proposed model).Practical relevance: The obtained results can be used in the development of systems based on coordinated efforts of community (primarily, community tagging systems). 

Translation and Validation of the Thai Version of the Wisconsin Quality of Life Questionnaire (TH WISQoL) for Kidney Stone Patients

2020 ◽  
Vol 103 (11) ◽  
pp. 1194-1199
Keyword(s):  
Quality Of Life ◽  
Internal Consistency ◽  
Kidney Stone ◽  
Convergent Validity ◽  
Large Scale ◽  
Short Form ◽  
Outcome Measurement ◽  
Life Questionnaire ◽  
Sf 36

Objective: To develop and validate a Thai version of the Wisconsin Quality of Life (TH WISQoL) Questionnaire. Materials and Methods: The authors developed the TH WISQoL Questionnaire based on a standard multi-step process. Subsequently, the authors recruited patients with kidney stone and requested them to complete the TH WISQoL and a validated Thai version of the 36-Item Short Form Survey (TH SF-36). The authors calculated the internal consistency and interdomain correlation of TH WISQoL and compared the convergent validity between the two instruments. Results: Thirty kidney stone patients completed the TH WISQoL and the TH SF-36. The TH WISQoL showed acceptable internal consistency for all domains (Cronbach’s alpha 0.768 to 0.909). Interdomain correlation was high for most domains (r=0.698 to 0.779), except for the correlation between Vitality and Disease domains, which showed a moderate correlation (r=0.575). For convergent validity, TH WISQoL demonstrated a good overall correlation to TH SF-36, (r=0.796, p<0.05). Conclusion: The TH WISQoL is valid and reliable for evaluating the quality of life of Thai patients with kidney stone. A further large-scale multi-center study is warranted to confirm its applicability in Thailand. Keywords: Quality of life, Kidney stone, Validation, Outcome measurement

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