40 results on '"Lu, Zhen"'
Search Results
2. Liner Shipping Service Planning Under Sulfur Emission Regulations
- Author
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Shuaian Wang, Lu Zhen, Chung Yee Lee, and Dan Zhuge
- Subjects
050210 logistics & transportation ,Ship routing ,021103 operations research ,Waste management ,media_common.quotation_subject ,05 social sciences ,0211 other engineering and technologies ,Air pollution ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Transportation ,02 engineering and technology ,Marine fuel ,medicine.disease_cause ,Sustainable transport ,0502 economics and business ,Service planning ,medicine ,Environmental science ,Quality (business) ,Air quality management ,Liner shipping ,Civil and Structural Engineering ,media_common - Abstract
Air emissions from ships have become an important issue in sustainable shipping because of the low quality of the marine fuel consumed by ships. To reduce sulfur emissions from shipping, the International Maritime Organization has established emission control areas (ECAs) where ships must use low-sulfur fuel with at most 0.1% sulfur or take equivalent emission-reduction measures. The use of low-sulfur fuel increases the costs for liner shipping companies and affects their operations management. This study addresses a holistic liner shipping service planning problem that integrates fleet deployment, schedule design, and sailing path and speed optimization, considering the effect of ECAs. We propose a nesting algorithmic framework to address this new and challenging problem. Semianalytical solutions are derived for the sailing path and speed optimization problem, which are used in the schedule design. A tailored algorithm is applied to solve schedule design problems, and the solutions are used in fleet deployment. The fleet deployment problem is then addressed by a dynamic programming-based pseudo-polynomial time algorithm. Numerical experiments demonstrate that considering the effect of ECAs in liner shipping operations management can reduce over 2% of the costs, which is significant considering that the annual operating cost of a shipping company’s network can be as high as several billion dollars.
- Published
- 2021
3. Shared mobility oriented open vehicle routing with order radius decision
- Author
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Zheyi Tan, Shuaian Wang, Wen Yi, Lu Zhen, and Junyan Lyu
- Subjects
050210 logistics & transportation ,Operations research ,Computer science ,05 social sciences ,0211 other engineering and technologies ,Mode (statistics) ,Transportation ,02 engineering and technology ,Management Science and Operations Research ,Delivery mode ,Sharing economy ,Order (exchange) ,0502 economics and business ,Vehicle routing problem ,Programming paradigm ,TRIPS architecture ,Column generation ,021108 energy ,Civil and Structural Engineering - Abstract
In the era of sharing economy and the mobility-as-service, the last mile delivery system is undergoing revolutionary changes with emerging a lot of new operation modes and policies. The crowdsourced delivery mode has become a novel and popular practice in the last mile delivery industry. This mode brings a novel way for facilitating the efficiency of last mile delivery on the basis of the shared mobility. This paper studies an open vehicle routing problem (OVRP) for the shared mobility based last mile delivery mode, in which parcel delivery orders are disseminated within a circle to attract occasional vehicles (or couriers) to fulfill these orders. Different from the traditional OVRP, this study further considers the decision of the above mentioned circle’s radius, which should be balanced between attracting enough vehicles and reducing additional cost (reward) for covering vehicles’ empty trips to the pickup location. This paper proposes a nonlinear mixed-integer programming model for the problem. A column generation based solution method is implemented to solve the model. Some numerical experiments are also conducted to validate the efficiency of the solution method and draw out some managerial implications for the practitioners. The proposed methodology in this paper may be potentially benefit not only for reducing the last mile delivery cost but also for promoting the modern transportation paradigm revolution to ridesharing and mobility-as-service.
- Published
- 2021
4. Column generation for low carbon berth allocation under uncertainty
- Author
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Wei Zhang, Wen Yi, Qian Sun, Kai Wang, and Lu Zhen
- Subjects
Marketing ,Mathematical optimization ,021103 operations research ,Computer science ,Strategy and Management ,0211 other engineering and technologies ,chemistry.chemical_element ,Workload ,02 engineering and technology ,Management Science and Operations Research ,Management Information Systems ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Column generation ,Carbon ,Assignment problem - Abstract
This article investigates a low carbon-oriented berth allocation and quay crane assignment problem considering vessels’ uncertain arrival time and loading/unloading workload for vessels. A two-stag...
- Published
- 2020
5. A Bi-Objective Model on Multiperiod Green Supply Chain Network Design
- Author
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Lu Zhen
- Subjects
050210 logistics & transportation ,021103 operations research ,Operations research ,Total cost ,Computer science ,Supply chain ,05 social sciences ,0211 other engineering and technologies ,Time horizon ,02 engineering and technology ,Numerical models ,Computer Science Applications ,Human-Computer Interaction ,Control and Systems Engineering ,0502 economics and business ,Bi objective ,Supply chain network ,Electrical and Electronic Engineering ,Software - Abstract
This paper extends a traditional supply chain network design problem through two perspectives, i.e., the multiperiod decision environment and the environmental concerns. A planning horizon contains multiple periods. Different periods have different demands of products and hence should have different supply chain decisions, which mainly include facilities’ locations, the environment protection level in facilities, as well as the transportation flows of products in the supply chain. For each facility in two consecutive periods, the changes of the location and environment protection level related decisions may incur adjustment cost. A bi-objective mixed-integer programming model is proposed to minimize both the total cost and the CO2 emissions of the supply chain during the planning horizon with multiple periods. A solution approach is proposed to solve the model. Numerical experiments are conducted to validate the effectiveness of the proposed model and algorithm.
- Published
- 2020
6. A vehicle routing problem arising in unmanned aerial monitoring
- Author
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Miao Li, Gilbert Laporte, Wencheng Wang, and Lu Zhen
- Subjects
0209 industrial biotechnology ,021103 operations research ,General Computer Science ,Computer science ,Heuristic ,Heuristic (computer science) ,Real-time computing ,0211 other engineering and technologies ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,Management Science and Operations Research ,Tabu search ,Set (abstract data type) ,020901 industrial engineering & automation ,Modeling and Simulation ,Vehicle routing problem ,Routing (electronic design automation) ,Metaheuristic - Abstract
Unmanned aerial vehicles (UAVs) are widely used to perform monitoring tasks both in the military and civilian areas, and the planning of their routes is critical. This study investigates a routing problem in which UAVs monitor a set of areas with different accuracy requirements. This problem is a variant of the classical vehicle routing problem (VRP), where one must determine not only the order in which to visit a set of nodes located in the plane, but also the height at which to visit them, which impacts the accuracy level and the service time. An integer programming model is formulated to optimize flight routes and minimize the total time needed to complete the monitoring tasks. A tabu search metaheuristic is developed for the problem. Extensive numerical experiments are conducted to assess the efficiency of the heuristic.
- Published
- 2019
7. Consistent vehicle routing problem with simultaneous distribution and collection
- Author
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Kai Wang, Chengle Ma, Lu Zhen, Wenya Lv, and Ziheng Xu
- Subjects
Marketing ,Mathematical optimization ,021103 operations research ,Distribution (number theory) ,Computer science ,Strategy and Management ,0211 other engineering and technologies ,02 engineering and technology ,Reverse logistics ,Management Science and Operations Research ,Management Information Systems ,Vehicle routing problem ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing - Abstract
To improve customer service in the reverse logistics, this article defines a new variant of the vehicle routing problem (VRP) by combining the consistent VRP (ConVRP) and the VRP with simultaneous ...
- Published
- 2019
8. Inspection routing problem for coal mine safety personnel in underground mines
- Author
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Miao Li, Lu Zhen, Bochen Wang, Lin Huang, and Wencheng Wang
- Subjects
021103 operations research ,General Computer Science ,Artificial neural network ,Computer science ,business.industry ,0211 other engineering and technologies ,General Engineering ,Coal mining ,02 engineering and technology ,Civil engineering ,Tabu search ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Routing (electronic design automation) ,business ,Integer programming - Abstract
Coal mine safety is the foundation of coal mine enterprise development, and inspections performed by safety personnel are an indispensable part of ensuring the production of coal mines. The complex network of tunnels in underground mines restricts the efficiency of safety inspection routes; therefore, planning these routes is critical. This study investigates a routing problem in which safety personnel start from multiple sites to inspect a set of sites. A mixed integer linear programming (MILP) model is formulated to optimize the inspection routes. Three methods are used to address the problem: a local branching (LB)-based solution method, a tabu search-based solution method and a back propagation (BP) neural network method. Numerical experiments are conducted to assess the efficiency of the methods on different scales.
- Published
- 2019
9. Hybrid electric vehicle routing problem with mode selection
- Author
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Liyang Xiao, Lu Zhen, Chengle Ma, and Ziheng Xu
- Subjects
0209 industrial biotechnology ,021103 operations research ,business.product_category ,Computer science ,Strategy and Management ,0211 other engineering and technologies ,Process (computing) ,Particle swarm optimization ,Green logistics ,02 engineering and technology ,Management Science and Operations Research ,Industrial and Manufacturing Engineering ,Automotive engineering ,020901 industrial engineering & automation ,Vehicle routing problem ,Electric vehicle ,Routing (electronic design automation) ,Hybrid vehicle ,Driving range ,business - Abstract
With the development of green logistics, logistics companies gradually are paying attention to the application of hybrid electric vehicles (HEVs). HEVs have the advantages of low energy consumption and pollution, while their disadvantage mainly lies in their limited continuous driving range. Therefore, it is necessary to optimize the use of fuel during the distribution process. We study the mode selection system in HEVs based on the background of green logistics and the above characteristics of HEVs. The mode selection system can adjust the driving mode of the HEV according to different road conditions to obtain the optimal use of fuel. In this paper, we propose a new study of a hybrid electric vehicle routing problem with mode selection. This problem is formulated as a mixed integer linear programming model. An improved particle swarm optimization algorithm (IPSO) is developed to solve this problem. Extensive numerical experiments are conducted to validate the effectiveness of the proposed model and the ...
- Published
- 2019
10. Facility location and scale optimisation in closed-loop supply chain
- Author
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Kai Wang, Lu Zhen, Xiaotian Zhang, and Qiuji Sun
- Subjects
0209 industrial biotechnology ,021103 operations research ,Scale (ratio) ,Computer science ,Strategy and Management ,Supply chain ,0211 other engineering and technologies ,02 engineering and technology ,Reverse logistics ,Management Science and Operations Research ,Decision problem ,Multi product ,Industrial engineering ,Industrial and Manufacturing Engineering ,Facility location problem ,020901 industrial engineering & automation ,Closed loop ,Remanufacturing - Abstract
This paper solves a strategic-level decision problem on determining the optimal location of (re)manufacturers and logistics centres with the consideration of facility scales in an integrated closed...
- Published
- 2019
11. Cranes scheduling in frame bridges based automated container terminals
- Author
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Xin Shi, Wencheng Wang, Lu Zhen, Chengle Ma, and Hongtao Hu
- Subjects
050210 logistics & transportation ,Schedule ,021103 operations research ,Mathematical model ,ComputingMethodologies_SIMULATIONANDMODELING ,Computer science ,05 social sciences ,0211 other engineering and technologies ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Transportation ,Control engineering ,Crane scheduling ,02 engineering and technology ,Computer Science Applications ,Scheduling (computing) ,0502 economics and business ,Automotive Engineering ,Civil and Structural Engineering ,Terminal system - Abstract
This paper investigates crane scheduling problems for a new type of automated container terminal system, which is based on multi-storey frame bridges. For the new design concept, this paper studies how to schedule two types of cranes, i.e., quay cranes and bridge cranes that transfer containers between different storeys. The schedules of these two types of cranes impact the operation efficiency of the terminal system. Mathematical models are proposed for the two scheduling problems. Meta-heuristics are developed to solve them. Numerical experiments are conducted to validate the effectiveness of the proposed models and the efficiency of the proposed solution method.
- Published
- 2018
12. A Decision Framework for Automatic Guided Vehicle Routing Problem with Traffic Congestions
- Author
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Yiwei Wu, Qiuji Sun, Lu Zhen, Qi Yue, and Si Zhang
- Subjects
Queueing theory ,021103 operations research ,Computer science ,Computation ,Distributed computing ,0211 other engineering and technologies ,010103 numerical & computational mathematics ,02 engineering and technology ,Management Science and Operations Research ,01 natural sciences ,Scheduling (computing) ,Vehicle routing problem ,Traffic conditions ,0101 mathematics ,Lattice graph - Abstract
Automatic guided vehicles are widely used in various types of warehouses including the automated container terminals. This paper provides a decision framework for port managers to design and schedule automatic guided vehicle routing plans under time-varying traffic conditions. A large number of computational experiments on a grid graph are conducted to validate the efficiency of the proposed decision framework. We also proposed one efficient queueing rule in automatic guided vehicle routing scheduling. Although the complexity of the problem is high, computational results show that our proposed decision framework can provide high quality solutions within a relatively short computation time.
- Published
- 2018
13. Capacitated closed-loop supply chain network design under uncertainty
- Author
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Yi Hu, Lu Zhen, Yiwei Wu, Shuaian Wang, and Wen Yi
- Subjects
Distribution center ,050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Computer science ,Supply chain ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,Stochastic programming ,Tabu search ,Artificial Intelligence ,0502 economics and business ,Programming paradigm ,Polymatroid ,Quadratic programming ,Supply chain network ,Information Systems - Abstract
This study optimizes the design of a closed-loop supply chain network, which contains forward and reverse directions and is subject to uncertainty in demands for new & returned products. To address uncertainty in decision-making, we formulate a two-stage stochastic mixed-integer non-linear programming model to determine the distribution center locations and their corresponding capacity, and new & returned product flows in the supply chain network to minimize total design and expected operating costs. We convert our model to a conic quadratic programming model given the complexity of our problem. Then, the conic model is added with certain valid inequalities, such as polymatroid inequalities, and extended with respect to its cover cuts so as to improve computational efficiency. Furthermore, a tabu search algorithm is developed for large-scale problem instances. We also study the impact of inventory weight, transportation weight, and marginal value of time of returned products by the sensitivity analysis. Several computational experiments are conducted to validate the effectiveness of the proposed model and valid inequalities.
- Published
- 2018
14. Unmanned aerial vehicle scheduling problem for traffic monitoring
- Author
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Miao Li, Shuaian Wang, Wenya Lv, Lu Zhen, and Xiaobo Qu
- Subjects
050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,General Computer Science ,Job shop scheduling ,Computer science ,0502 economics and business ,05 social sciences ,0211 other engineering and technologies ,General Engineering ,02 engineering and technology ,Integer programming ,Arc routing - Abstract
For more accurate multiple-period real-time monitoring of road traffic, this paper investigates the unmanned aerial vehicle scheduling problem with uncertain demands. A mixed integer programming model is designed for this problem by combining the capacitated arc routing problem with the inventory routing problem. A local branching based solution method is developed to solve the model. A case study which applies this model to the road traffic in Shanghai is performed. In addition, numerical experiments are conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution method.
- Published
- 2018
15. Task assignment and sequencing decision model under uncertain available time of service providers
- Author
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Xin Shi, Lufei Huang, Yi Hu, Lu Zhen, and Hao Hao
- Subjects
Marketing ,050210 logistics & transportation ,021103 operations research ,Basis (linear algebra) ,Operations research ,Computer science ,Heuristic ,Strategy and Management ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,Management Science and Operations Research ,Decision problem ,Service provider ,Stochastic programming ,Management Information Systems ,Task (project management) ,0502 economics and business ,Decision model ,Finite set - Abstract
This paper studies an integrated decision problem on assigning and sequencing tasks to service providers. By considering the uncertain available time of the service providers, a stochastic programming model is proposed on the basis of a finite set of scenarios. Some realistic factors are also taken into account and formulated as some non-linear cost functions, which are linearised in this study. Moreover, a heuristic solution method is designed for solving some extremely large-scale problem cases within a reasonable period of time. Numerical experiments are performed to validate the effectiveness of the proposed model and the efficiency of the proposed solution method.
- Published
- 2018
16. Daily berth planning in a tidal port with channel flow control
- Author
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Ek Peng Chew, Dan Zhuge, Loo Hay Lee, Zhe Liang, and Lu Zhen
- Subjects
050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Computer science ,05 social sciences ,Control (management) ,0211 other engineering and technologies ,Transportation ,02 engineering and technology ,Management Science and Operations Research ,Port (computer networking) ,Open-channel flow ,Set (abstract data type) ,Test case ,0502 economics and business ,Column generation ,Assignment problem ,Decision model ,Civil and Structural Engineering ,Marine engineering - Abstract
This paper studies an operational-level berth allocation and quay crane assignment problem (daily berth planning) considering tides and channel flow control constraints. An integer programming model is proposed for this problem. Then a column generation solution approach is developed on a set partitioning based reformulation of the original model. Computational study is conducted on 30 test cases constructed from real-world data to validate efficiency of the proposed solution approach. Results show that this simple but practical solution approach can optimally solve the daily berthing planning problem instances with up to 80 vessels, 40 berths, and 120 quay cranes within one hour, which is reasonable and acceptable for the real-world applications. The proposed decision model and the solution approach could be potentially useful for some tidal ports with (or without) navigation channels.
- Published
- 2017
17. Production stage allocation problem in large corporations
- Author
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Sheng Lei Zhu, Dan Zhuge, and Lu Zhen
- Subjects
050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Information Systems and Management ,Operations research ,business.industry ,Strategy and Management ,05 social sciences ,0211 other engineering and technologies ,Automotive industry ,Scheduling (production processes) ,Particle swarm optimization ,02 engineering and technology ,Management Science and Operations Research ,Decision problem ,Diseconomies of scale ,Stochastic programming ,0502 economics and business ,Economics ,Revenue ,Fixed cost ,business - Abstract
This paper studies a strategic-level decision problem on assigning production stages to geographically distributed subsidiaries in a large corporation so as to minimize the fixed cost and the expected value of the production/transportation costs under stochastic demands of customers. The influence of the economies and diseconomies of scale on unit production cost is considered. A nonlinear mixed integer programming model is designed for this problem. A local branching based solution method and a particle swarm optimization based solution method are developed for solving the model. Computational tests on real world data of Shanghai Volkswagen Auto Corp. are conducted. The results show that the proposed model can save about 2.5% of its revenue by comparing with the current decisions.
- Published
- 2017
18. Ship type decision considering empty container repositioning and foldable containers
- Author
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Shuaian Wang, Kai Wang, Lu Zhen, and Xiaobo Qu
- Subjects
Network simplex algorithm ,050210 logistics & transportation ,Engineering ,021103 operations research ,Operations research ,business.industry ,05 social sciences ,0211 other engineering and technologies ,Transportation ,02 engineering and technology ,Type (model theory) ,Flow network ,EMPTY CONTAINER ,Transport engineering ,0502 economics and business ,Business and International Management ,business ,Civil and Structural Engineering - Abstract
This paper addresses a problem of ship type decision considering empty container repositioning and foldable containers, which determines the capacity of ships deployed in a given shipping route at a tactical level and empty container repositioning between ports at an operational level. It considers the use of foldable containers and aims to find under what conditions, a shipping liner needs to use the foldable containers. To solve the problem, we formulate a network flow model with a revised network simplex algorithm, based on which an exact solution approach is designed to determine the optimal ship type.
- Published
- 2017
19. Optimizing Locations and Scales of Distribution Centers Under Uncertainty
- Author
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Lu Zhen, Weirong Wang, and Dan Zhuge
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,021103 operations research ,Distribution (number theory) ,Computer science ,Stochastic process ,Supply chain ,0211 other engineering and technologies ,Particle swarm optimization ,02 engineering and technology ,Decision problem ,Facility location problem ,Stochastic programming ,Computer Science Applications ,Human-Computer Interaction ,020901 industrial engineering & automation ,Control and Systems Engineering ,Relaxation (approximation) ,Electrical and Electronic Engineering ,Software - Abstract
In supply chain networks of large companies, how to determine the location for establishing distribution centers is an important strategic-level decision problem. This paper proposes a stochastic programming model to determine distribution centers’ locations as well as their scales. The objective of the model is to minimize the expected total transportation cost under uncertain demands of customers. An improved particle swarm optimization algorithm and a Lagrangean relaxation-based solution approach are proposed to solve the model. This paper also performs a case study on applying this model to the largest retailer in China. In addition, some numerical experiments are conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution methods.
- Published
- 2017
20. Analysis of three container routing strategies
- Author
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Lu Zhen, Dan Zhuge, and Shuaian Wang
- Subjects
050210 logistics & transportation ,Economics and Econometrics ,021103 operations research ,Operations research ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,Management Science and Operations Research ,General Business, Management and Accounting ,Industrial and Manufacturing Engineering ,Profit (economics) ,0502 economics and business ,Economics ,Heuristic routing ,Liner shipping - Abstract
As containers need several weeks to be delivered to their destinations and the future container shipment demand is uncertain, a myopic strategy for container routing that maximizes the immediate profit may lead to insufficient remaining capacity for transporting more profitable containers in the future. This study conducts a theoretical analysis to compare three container routing strategies, i.e., (i) a widely used myopic strategy, (ii) a non-myopic heuristic routing strategy that incorporates information about the future demand distribution, and (iii) a strategy that assumes future demand is known. Then a practical non-myopic heuristic container routing strategy is developed for practical purposes to increase the profit of liner shipping companies. Extensive numerical experiments show that the proposed non-myopic heuristic container routing strategy brings in an extra of 2%–3% profit over the myopic strategy.
- Published
- 2017
21. Crowdsourcing mode evaluation for parcel delivery service platforms
- Author
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Yiwei Wu, Wen Yi, Shuaian Wang, and Lu Zhen
- Subjects
Flexibility (engineering) ,Economics and Econometrics ,Service (systems architecture) ,021103 operations research ,Computer science ,business.industry ,05 social sciences ,0211 other engineering and technologies ,Mode (statistics) ,02 engineering and technology ,E-commerce ,Management Science and Operations Research ,Crowdsourcing ,General Business, Management and Accounting ,Data science ,Maturity (finance) ,Industrial and Manufacturing Engineering ,Task (project management) ,Competition (economics) ,0502 economics and business ,business ,050203 business & management - Abstract
The fast-growing practice of e-commerce implies a strong increase in the urban parcel delivery, which in turn creates significant pressure on last-mile city logistics. Because the crowdsourced delivery offers greater flexibility and requires less capital investment than traditional delivery methods, it has been playing a more crucial role when faced with the growing demand for the urban parcel delivery. With the increasing maturity of the crowdsourced delivery and the fierce competition among platforms, the evaluation of different crowdsourcing modes for the urban parcel delivery becomes important. This study proposes six mathematical models to evaluate different operation modes of the crowdsourced delivery in a quantitative way. Several realistic factors, such as the latest service time for each task, task cancellation rate and range distribution of tasks, are also analyzed in this paper. Numerical experiments are conducted to validate the effectiveness of the proposed models and to analyze the impact of different modes. Some managerial implications are also outlined on the basis of the numerical experiments and sensitivity analysis to help crowdsourced companies to make scientific decisions.
- Published
- 2021
22. Dynamic programming for optimal ship refueling decision
- Author
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Shuaian Wang, Dan Zhuge, and Lu Zhen
- Subjects
050210 logistics & transportation ,Engineering ,021103 operations research ,Water transport ,Operations research ,business.industry ,05 social sciences ,0211 other engineering and technologies ,Transportation ,02 engineering and technology ,Optimal control ,Port (computer networking) ,Dynamic programming ,0502 economics and business ,Fuel efficiency ,Probability distribution ,Business and International Management ,business ,Liner shipping ,Civil and Structural Engineering ,Optimal decision - Abstract
This study investigates an optimal control policy for a liner ship to decide at which ports and how much fuel the liner ship should be refueled under stochastic fuel consumption in each leg and stochastic fuel price at each port. Based on some properties proved in this study, a dynamic programming algorithm is then designed to obtain some important threshold values, which are used in the optimal control policy for ship refueling decision. Extensive experiments show that the proposed method can obtain the optimal decision within a reasonable time (about 170 s) for various scales of problem instances (up to 30 ports) as well as various settings of probability distributions. In addition, some comparative experiments also show that the proposed optimal decision policy can save at least 8% fuel consumption cost by comparing with some relatively simple rules and save about 1% cost on average by comparing with some brilliantly-designed rules.
- Published
- 2017
23. A two-stage decomposition method on fresh product distribution problem
- Author
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Hongtao Hu, Lu Zhen, and Ye Zhang
- Subjects
050210 logistics & transportation ,Mathematical optimization ,Engineering ,021103 operations research ,Job shop scheduling ,Heuristic (computer science) ,business.industry ,Strategy and Management ,05 social sciences ,0211 other engineering and technologies ,Refrigerator car ,Particle swarm optimization ,02 engineering and technology ,Energy consumption ,Management Science and Operations Research ,Industrial and Manufacturing Engineering ,0502 economics and business ,Shortest path problem ,Vehicle routing problem ,Decomposition method (constraint satisfaction) ,business - Abstract
Refrigerator cars are widely used for fresh product distribution. The energy consumption of these vehicles is sensitive to the environment temperature, and changes continuously due to fluctuations of the environment temperature. As a result, the total refrigeration cost is influenced by the car’s departure time. To reduce operation costs of third-party transportation providers, the refrigerator car scheduling problem is addressed in this research. A time-dependent mixed-integer programming model is established to reduce total operation costs, including routing, time penalty, cargo damage and refrigeration costs. An adaptive heuristic method is proposed by combining the variable neighbourhood search and particle swarm optimisation. To improve the algorithm quality, a two-stage decomposition method is developed. The problem is divided into two echelon sub-problems. One is the shortest path problem, and the other is the departure time scheduling problem. A feedback strategy is utilised to avoid local optimal...
- Published
- 2017
24. Cruise service planning considering berth availability and decreasing marginal profit
- Author
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Kai Wang, Lu Zhen, Xiaobo Qu, and Shuaian Wang
- Subjects
050210 logistics & transportation ,Engineering ,Mathematical optimization ,021103 operations research ,Marginal profit ,Operations research ,business.industry ,Logistics & Transportation ,05 social sciences ,Cruise ,0211 other engineering and technologies ,Transportation ,Time horizon ,02 engineering and technology ,Management Science and Operations Research ,Nonlinear programming ,Network planning and design ,0502 economics and business ,business ,Greedy algorithm ,Decision model ,Integer programming ,Civil and Structural Engineering - Abstract
© 2016 Elsevier Ltd This paper addresses a decision problem on planning cruise services for a cruise ship so as to maximize the total profit during a planning horizon. The service is a sequence of ports (harbor cities) that the cruise ship visits. In this decision problem, the constraint about the availability of berths at each port is taken into account. In reality, if a cruise service is executed by the ship repeatedly for several times, the profit earned by the cruise service in each time decreases gradually. This effect of decreasing marginal profit is also considered in this study. We propose a nonlinear integer programming model to cater to the concavity of the function for the profit of operating a cruise service repeatedly. To solve the nonlinear model, two linearization methods are developed, one of which takes advantage of the concavity for a tailored linearization. Some properties of the problem are also investigated and proved by using the dynamic programming (DP) and two commonly used heuristics. In particular, we prove that if there is only one candidate cruise service, a greedy algorithm can derive the optimal solution. Numerical experiments are conducted to validate the effectiveness of the proposed models and the efficiency of the proposed linearization methods. In case some parameters needed by the model are estimated inexactly, the proposed decision model demonstrates its robustness and can still obtain a near-optimal plan, which is verified by experiments based on extensive real cases.
- Published
- 2017
25. Multi-period distribution center location and scale decision in supply chain network
- Author
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Shucheng Yu, Dan Zhuge, Lu Zhen, and Weirong Wang
- Subjects
Distribution center ,050210 logistics & transportation ,Mathematical optimization ,Engineering ,021103 operations research ,General Computer Science ,Scale (ratio) ,business.industry ,Multi period ,05 social sciences ,0211 other engineering and technologies ,General Engineering ,Perfect information ,02 engineering and technology ,Facility location problem ,Stochastic programming ,0502 economics and business ,Programming paradigm ,Supply chain network ,business - Abstract
This study extends a problem on locating distribution centers under uncertainty.The decision on facility size is considered.This study is oriented to multiple period decision contexts.A mixed-integer programming model as well as lower, upper bounds are developed. This study extends a traditional problem on locating distribution centers (DC) under uncertain demands, and proposes a stochastic programming model on locating DCs, determining their suitable scales, as well as adjusting DCs so as to adapt to the dynamically changing demands at the sites of retailers. Some lower and upper bounds are also designed to analyze the values of the perfect information, stochastic solution, and the DC adjustments. Numerical experiments are conducted to validate the effectiveness of the proposed model.
- Published
- 2016
26. Multi-period yard template planning in container terminals
- Author
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Zhou Xu, Kai Wang, Yi Ding, and Lu Zhen
- Subjects
Truck ,050210 logistics & transportation ,Engineering ,Mathematical optimization ,021103 operations research ,business.industry ,05 social sciences ,0211 other engineering and technologies ,Particle swarm optimization ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Transportation ,02 engineering and technology ,Decision rule ,Management Science and Operations Research ,Port (computer networking) ,Yard ,Traffic congestion ,0502 economics and business ,Container (abstract data type) ,business ,Integer programming ,Simulation ,Civil and Structural Engineering - Abstract
This paper is about yard management in container ports. As a tactical level decision-making tool in a port, a yard template determines the assignment of spaces (subblocks) in a yard for arriving vessels, which visit the port periodically. The objective of yard template planning is to minimize the transportation cost of moving containers around the yard. To handle yard template planning, a mixed integer programming model is proposed that also takes into account traffic congestion in the yard. A further complication is that the cycle time of the vessels' periodicities is not uniform and varies among them, perhaps being one week, ten days, or two weeks, etc. However, this multiple cycle time of the periodicities of vessel arrival patterns, which complicates the yard template decision, is also considered in the model. Moreover, a local branching based solution method and a Particle Swarm Optimization based solution method are developed for solving the model. Numerical experiments are also conducted to validate the effectiveness of the proposed model, which can save around 24% of the transportation costs of yard trucks when compared with the commonly used First-Come-First-Served decision rule. Moreover, the proposed solution methods can not only solve the proposed model within a reasonable time, but also obtain near-optimal results with about 0.1–2% relative gap.
- Published
- 2016
27. Scheduling quay cranes and yard trucks for unloading operations in container ports
- Author
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Lu Zhen, Zhuo Sun, Shucheng Yu, and Shuaian Wang
- Subjects
Truck ,021103 operations research ,Optimization problem ,Computational complexity theory ,Job shop scheduling ,Computer science ,0211 other engineering and technologies ,General Decision Sciences ,Particle swarm optimization ,02 engineering and technology ,Management Science and Operations Research ,Solver ,Scheduling (computing) ,Genetic algorithm ,Programming paradigm ,Simulation - Abstract
This paper studies an integrated optimization problem on quay crane and yard truck scheduling in container terminals. A mixed-integer programming model is formulated. For the model, we show the integrated scheduling problem is strongly NP-hard and investigate some properties that can considerably reduce the computational complexity. For solving the proposed model within a reasonable time, a particle swarm optimization based solution method is developed. Numerical experiments are conducted to compare the proposed method with the CPLEX solver and the genetic algorithm. The results validate the effectiveness of the proposed model and the efficiency of the proposed solution method.
- Published
- 2016
28. Terminal allocation problem in a transshipment hub considering bunker consumption
- Author
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Kai Wang, Lu Zhen, and Shuaian Wang
- Subjects
Consumption (economics) ,050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Transshipment (information security) ,Computer science ,05 social sciences ,0211 other engineering and technologies ,Particle swarm optimization ,Ocean Engineering ,02 engineering and technology ,Decision rule ,Management Science and Operations Research ,Port (computer networking) ,Bunker ,Terminal (electronics) ,First-come, first-served ,Modeling and Simulation ,0502 economics and business ,Operations management - Abstract
This article investigates the method of allocating arriving vessels to the terminals in transshipment hubs. The terminal allocation decision faced by a shipping alliance has the influence on the scheduled arrival time of vessels and further affects the bunker consumption cost for the vessels. A model is formulated to minimize the bunker consumption cost as well as the transportation cost of inter-terminal transshipment flows/movements. The capacity limitation of the port resources such as quay cranes (QCs) and berths is taken into account. Besides the terminal allocation, the QC assignment decision is also incorporated in the proposed model. A local branching based method and a particle swarm optimization based method are developed to solve the model in large-scale problem instances. Numerical experiments are also conducted to validate the effectiveness of the proposed model, which can save around 14% of the cost when compared with the “First Come First Served” decision rule. Moreover, the proposed solution methods not only solve the proposed model within a reasonable computation time, but also obtain near-optimal results with about 0.1∼0.7% relative gap. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 529–548, 2016
- Published
- 2016
29. The Joint quay crane scheduling and block allocation problem in container terminals
- Author
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Chengle Ma, Xiaotian Zhang, Xiazhong Chen, Lu Zhen, and Hongtao Hu
- Subjects
050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Quay crane ,Computer science ,Applied Mathematics ,Strategy and Management ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,Management Science and Operations Research ,Management Information Systems ,Scheduling (computing) ,Modeling and Simulation ,Block (telecommunications) ,0502 economics and business ,Container (abstract data type) ,Joint (building) ,General Economics, Econometrics and Finance - Published
- 2018
30. Data-Driven Intelligent Port Management Based on Blockchain
- Author
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Maria Attard, Lu Zhen, Shuaian Wang, and Liyang Xiao
- Subjects
050210 logistics & transportation ,Government ,021103 operations research ,Blockchain ,Computer science ,business.industry ,05 social sciences ,0211 other engineering and technologies ,Ocean Engineering ,02 engineering and technology ,Management Science and Operations Research ,Port (computer networking) ,Data-driven ,0502 economics and business ,Port management ,Telecommunications ,business - Abstract
This paper proposes a blockchain-based framework to improve the efficiency of ship traffic in port. In the framework, ship agents, terminals, tug company, pilot station, and government share information and the information is stored in a blockchain. Based on the shared information, we discuss three categories of data-driven models that can improve the operations management of the above five parties. The first category is decisions made by a single party. The second category involves decisions of at least two ship agents. The third category relates to multi-party decision-making under uncertainty. This study hopes to stimulate maritime practitioners to embrace blockchain technology and data-driven approaches to enhance the competitiveness of the industry.
- Published
- 2020
31. Green logistics location-routing problem with eco-packages
- Author
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Lu Zhen, Xuesong Zhou, Yong Wang, Monirehalsadat Mahmoudi, and Shouguo Peng
- Subjects
050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Computer science ,05 social sciences ,0211 other engineering and technologies ,Sorting ,Transportation ,Green logistics ,02 engineering and technology ,Flow network ,Shared resource ,symbols.namesake ,Lagrangian relaxation ,0502 economics and business ,Shortest path problem ,Genetic algorithm ,symbols ,Business and International Management ,Cluster analysis ,Civil and Structural Engineering - Abstract
Optimization of the green logistics location-routing problem with eco-packages involves solving a two-echelon location-routing problem and the pickup and delivery problem with time windows. The first echelon consists of large eco-package transport, which is modeled by a time-discretized transport-concentrated network flow programming in the resource sharing state–space–time (SST) network. The second echelon focuses on small eco-package pickups and deliveries, established by the cost-minimized synchronization-oriented location routing model that minimizes the total generalized cost, which includes internal transportation cost, value of eco-packages, short-term benefits and environmental externalities. In addition, the Gaussian mixture clustering algorithm is utilized to assign customers to their respective service providers in the pickup and delivery process, and a Clarke–Wright saving method-based non-dominated sorting genetic algorithm II is designed to optimize pickup and delivery routes, and improve their cost-effectiveness and degree of synchronization. Different strategy testing results are used in the service phase as input data to calculate the cost of the transport phase, which is solved through a Lagrangian relaxation approach. The 3D SST network representation innovatively captures the eco-package route sequence and state transition constraints over the shortest path in the pickup and delivery at any given moment of the transport phase. A large-scale logistics network in Chengdu, China, is used to demonstrate the proposed model and algorithm, and undertake sensitivity analysis considering the life cycle of green eco-packages.
- Published
- 2020
32. Supply chain optimization in context of production flow network
- Author
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Dan Zhuge, Lu Zhen, and Jingqi Lei
- Subjects
Engineering ,021103 operations research ,Operations research ,business.industry ,0211 other engineering and technologies ,Context (language use) ,02 engineering and technology ,Finished good ,Flow network ,Stochastic programming ,Control and Systems Engineering ,Multinational corporation ,0202 electrical engineering, electronic engineering, information engineering ,Production (economics) ,020201 artificial intelligence & image processing ,Supply chain network ,Supply chain optimization ,business ,Information Systems - Abstract
For large multinational companies, the complex production process of their finished goods usually contains plenty of stages, which constitute a production flow network. Each production stage in the production flow network can be undertaken by one or more suppliers. This study proposes a stochastic programming model for the production flow network oriented supply chain network design problem, which optimizes the decision of allocating stages to suppliers with the objective of minimizing the total expected costs of production and transportation among suppliers under uncertain demands of customers. A local branching based solution method is developed to solve the model. A case study on applying this model to a large automobile company is performed. In addition, some numerical experiments are conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution method.
- Published
- 2016
33. Influence of triethanolamine on the hydration product of portlandite in cement paste and the mechanism
- Author
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Zhang Qing, Zhang Yan-Rong, Lu Zhen-Bao, Dong Biqin, Lu Zi-Chen, Xing Feng, and Kong Xiangming
- Subjects
Materials science ,0211 other engineering and technologies ,02 engineering and technology ,engineering.material ,Portlandite ,law.invention ,chemistry.chemical_compound ,law ,Phase (matter) ,021105 building & construction ,medicine ,General Materials Science ,Lamellar structure ,Crystallization ,Composite material ,Calcium silicate hydrate ,Cement ,Calcium hydroxide ,food and beverages ,Building and Construction ,021001 nanoscience & nanotechnology ,chemistry ,Chemical engineering ,Triethanolamine ,engineering ,0210 nano-technology ,medicine.drug - Abstract
The influences of triethanolamine (TEA) on the portlandite in hardened cement pastes (HCPs) were systematically investigated. Results show that the addition of TEA in cement pastes leads to a visible reduction of Ca(OH)2 (CH) content and considerably alters the morphology of CH crystals from large and parallel-stacked lamellar shape to smaller and distorted actinomorphic one. For the first time, the CH micro-crystals and even non-crystalline CH in HCPs were observed in the presence of TEA. Due to integration of CH micro-crystals in C–S–H phase, remarkable higher Ca/Si ratio of C–S–H phase was found. The formation of TEA-Ca2 + complex via the interaction between Ca2 + and the oxygen atoms in TEA molecule was evidenced by the results of NMR and UV. It is believed that TEA can be introduced into the crystallization process of portlandite and thus significantly alters the morphology of CH crystals and even the content of the crystalline CH phase.
- Published
- 2016
34. Modeling of yard congestion and optimization of yard template in container ports
- Author
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Lu Zhen
- Subjects
Truck ,050210 logistics & transportation ,Engineering ,021103 operations research ,Operations research ,business.industry ,05 social sciences ,0211 other engineering and technologies ,Probabilistic logic ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Transportation ,Context (language use) ,02 engineering and technology ,Management Science and Operations Research ,Yard ,Traffic congestion ,0502 economics and business ,Container (abstract data type) ,Programming paradigm ,business ,Integer programming ,Simulation ,Civil and Structural Engineering - Abstract
As a tactical-level plan, a yard template determines the assignment of spaces in a container port yard for arriving vessels. This paper investigates the concept of yard congestion quantitatively in the context of yard truck interruptions, and develops a combination of probabilistic and physics-based models for truck interruptions. The above work enables us to exactly evaluate the expected link travel time, which then acts as the basis for proposing a mixed-integer programming model that minimizes the total expected travel time of moving containers around the yard. A Squeaky Wheel Optimization based meta-heuristic is developed to solve the model. Experiments are also conducted to validate the effectiveness of the model and the solution method.
- Published
- 2016
35. Quay crane scheduling problem with considering tidal impact and fuel consumption
- Author
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Shucheng Yu, Lu Zhen, and Shuaian Wang
- Subjects
050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Job shop scheduling ,Quay crane ,Computer science ,05 social sciences ,0211 other engineering and technologies ,Particle swarm optimization ,02 engineering and technology ,Management Science and Operations Research ,Port (computer networking) ,Industrial and Manufacturing Engineering ,Nonlinear programming ,Nonlinear system ,0502 economics and business ,Fuel efficiency ,Simulation - Abstract
This study investigates a quay crane scheduling problem with considering the impact of tides in a port and fuel consumption of ships. A mixed-integer nonlinear programming model is proposed. Some nonlinear parts in the model are linearized by approximation approaches. For solving the proposed model in large-scale problem instances, both a local branching based solution method and a particle swarm optimization based solution method are developed. Numerical experiments with some real-world like cases are conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution methods.
- Published
- 2016
36. Models on ship scheduling in transshipment hubs with considering bunker cost
- Author
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Tao Shen, Lu Zhen, Shuaian Wang, and Shucheng Yu
- Subjects
050210 logistics & transportation ,Economics and Econometrics ,021103 operations research ,Operations research ,Computer science ,05 social sciences ,0211 other engineering and technologies ,Scheduling (production processes) ,02 engineering and technology ,Management Science and Operations Research ,Decision problem ,General Business, Management and Accounting ,Industrial and Manufacturing Engineering ,Transshipment ,Bunker ,0502 economics and business ,Integer programming - Abstract
This paper studies a decision problem for scheduling ships׳ starting operation time in a transshipment hub with considering the bunker cost and the transshipment cost of containers. Based on the information about the handing capacity of the container port in each period, the port operator makes a proper decision and informs the shipping companies about the start operation days of each liner route. The optimized decision may help shipping companies significantly reduce the cost. This study proposes a mixed integer programming model. The NP-hardness of the problem is proved. A local branching based solution method is also developed for solving the model. Extensive numerical experiments demonstrate the optimality of the solution by the proposed method is less than 3% for large-scale problem instances.
- Published
- 2016
37. Bus tour-based routing and truck deployment for small-package shipping companies
- Author
-
Lu Zhen, Jun Xia, Yiwei Wu, and Lin Huang
- Subjects
Waiting time ,Truck ,050210 logistics & transportation ,Mathematical optimization ,021103 operations research ,Linear programming ,Computer science ,05 social sciences ,0211 other engineering and technologies ,Particle swarm optimization ,Transportation ,02 engineering and technology ,Solver ,Nonlinear programming ,Software deployment ,0502 economics and business ,Business and International Management ,Routing (electronic design automation) ,Civil and Structural Engineering - Abstract
This study investigates a joint optimisation of routing and truck deployment for a small-package shipping company. Bus tour-based services are provided to collect express packages at customer bases. The objective of the optimisation problem is to minimise the average waiting time for packages stored at the customer bases. We first propose a mixed-integer nonlinear programming model. The proposed formulation is linearised and made solvable by an off-the-shelf mixed-integer linear programming solver. For solving larger instances of the problem, we propose two optimisation approaches that can obtain near-optimal solutions – a local branching-based method and a particle swarm optimisation-based method. We conduct numerical experiments to validate the effectiveness and efficiency of the proposed solution methods. The results indicate that both methods can obtain optimal solutions quickly for most of the small-scale instances. For medium-size instances, the local branching-based method performs best, and the PSO-based method outperforms the others for large-size instances.
- Published
- 2020
38. Tug scheduling for hinterland barge transport: A branch-and-price approach
- Author
-
Xiaobo Qu, Kai Wang, Lu Zhen, and Shuaian Wang
- Subjects
050210 logistics & transportation ,geography ,Operations Research ,021103 operations research ,Information Systems and Management ,geography.geographical_feature_category ,General Computer Science ,Operations research ,Computer science ,Branch and price ,05 social sciences ,BARGE ,0211 other engineering and technologies ,Scheduling (production processes) ,02 engineering and technology ,Management Science and Operations Research ,Flow network ,Industrial and Manufacturing Engineering ,Modeling and Simulation ,0502 economics and business ,River mouth - Abstract
© 2017 Elsevier B.V. In a hinterland barge transport system, barges are usually not self-propelled and need to be towed or pushed by tugs. This study investigates a tug-scheduling problem at a seaport that is located at a river mouth and that connects the hinterland ports along the river with the global maritime transportation network. A mixed-integer programming model is proposed to optimize the assignment of barges to tugs as well as the time when the tugs depart from the seaport and go to the hinterland ports. Some properties of the model are also investigated. Moreover, an exact solution method based on a branch-and-price approach is developed to solve the proposed model. Numerical experiments are also conducted to validate the effectiveness of the proposed model and the efficiency of the proposed solution method.
- Published
- 2018
39. Cruise itinerary schedule design
- Author
-
Kai Wang, Shuaian Wang, Lu Zhen, and Xiaobo Qu
- Subjects
050210 logistics & transportation ,Engineering ,021103 operations research ,Operations research ,GeneralLiterature_INTRODUCTORYANDSURVEY ,business.industry ,05 social sciences ,Cruise ,0211 other engineering and technologies ,02 engineering and technology ,Port (computer networking) ,Industrial and Manufacturing Engineering ,Dynamic programming ,0502 economics and business ,business ,Itinerary planning - Abstract
© 2017 "IISE". The Cruise Itinerary Schedule Design (CISD) problem determines the optimal sequence of a given set of ports of call (a port of call is an intermediate stop in a cruise itinerary) and the arrival and departure times at each port of call in order to maximize the monetary value of the utility at ports of call minus the fuel cost. To solve this problem, in view of the practical observations that most cruise itineraries do not have many ports of call, we first enumerate all sequences of ports of call and then optimize the arrival and departure times at each port of call by developing a dynamic programming approach. To improve the computational efficiency,we propose effective bounds on the monetary value of each sequence of ports of call, eliminating non-optimal sequences without invoking the dynamic programming algorithm. Extensive computational experiments are conducted and the results showthat, first, using the bounds on the profit of each sequence of ports of call considerably improves the computational efficiency; second, the total profit of the cruise itinerary is sensitive to the fuel price and hence an accurate estimation of the fuel price is highly desirable; third, the optimal sequence of ports of call is not necessarily the sequencewith the shortest voyage distance, especially when the ports do not have a natural geographic sequence.
- Published
- 2017
40. Numerical Simulation on Mechanical Response of Buried Pipeline under Uneven Settlement
- Author
-
Qikun Ma, Mei Yang, Yan-hua Chen, Lu-zhen Jiang, and Dong-Dong Li
- Subjects
biology ,Computer simulation ,Settlement (structural) ,0211 other engineering and technologies ,02 engineering and technology ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Pipeline (software) ,Geotechnical engineering ,Adina ,Geology ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Published
- 2017
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