scholarly journals Stochastic Drone Fleet Deployment and Planning Problem Considering Multiple-Type Delivery Service

2019 ◽  
Vol 11 (14) ◽  
pp. 3871 ◽  
Author(s):  
Ming Liu ◽  
Xin Liu ◽  
Maoran Zhu ◽  
Feifeng Zheng
Keyword(s):  
Operating Cost ◽  
Hybrid Genetic Algorithm ◽  
Sample Average Approximation ◽  
Labor Cost ◽  
Planning Problem ◽  
Two Stage ◽  
Time Segment ◽  
Delivery Service ◽  
Delivery Routes ◽  
Fleet Deployment

Drone delivery has a great potential to change the traditional parcel delivery service in consideration of cost reduction, resource conservation, and environmental protection. This paper introduces a novel drone fleet deployment and planning problem with uncertain delivery demand, where the delivery routes are fixed and couriers work in collaboration with drones to deliver surplus parcels with a relatively higher labor cost. The problem involves the following two-stage decision process: (i) The first stage determines the drone fleet deployment (i.e., the numbers and types of drones) and the drone delivery service module (i.e., the time segment between two consecutive departures) on a tactical level, and (ii) the second stage decides the numbers of parcels delivered by drones and couriers on an operational level. The purpose is to minimize the total cost, including (i) drone deployment and operating cost and (ii) expected labor cost. For the problem, a two-stage stochastic programming formulation is proposed. A classic sample average approximation method is first applied. To achieve computational efficiency, a hybrid genetic algorithm is further developed. The computational results show the efficiency of the proposed approaches.

Liner Shipping Service Planning Under Sulfur Emission Regulations

2020 ◽  
Author(s):  
Shuaian Wang ◽  
Dan Zhuge ◽  
Lu Zhen ◽  
Chung-Yee Lee
Keyword(s):  
Operations Management ◽  
Operating Cost ◽  
Liner Shipping ◽  
Service Planning ◽  
Planning Problem ◽  
Marine Fuel ◽  
Speed Optimization ◽  
Schedule Design ◽  
Low Sulfur ◽  
Fleet Deployment

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.

scholarly journals Model and Algorithm of Two-Stage Distribution Location Routing with Hard Time Window for City Cold-Chain Logistics

2020 ◽  
Vol 10 (7) ◽  
pp. 2564
Author(s):  
Liying Yan ◽  
Manel Grifoll ◽  
Pengjun Zheng
Keyword(s):  
Time Window ◽  
Hybrid Genetic Algorithm ◽  
Distribution Networks ◽  
Cold Chain ◽  
Two Stage ◽  
Logistics Network ◽  
Stage Distribution ◽  
Hard Time ◽  
Location Routing ◽  
Logistics Enterprises

Taking cold-chain logistics as the research background and combining with the overall optimisation of logistics distribution networks, we develop two-stage distribution location-routing model with the minimum total cost as the objective function and varying vehicle capacity in different delivery stages. A hybrid genetic algorithm is designed based on coupling and collaboration of the two-stage routing and transfer stations. The validity and feasibility of the model and algorithm are verified by conducting a randomly generated test. The optimal solutions for different objective functions of two-stage distribution location-routing are compared and analysed. Results turn out that for different distribution objectives, different distribution schemes should be employed. Finally, we compare the two-stage distribution location-routing to single-stage vehicle routing problems. It is found that a two-stage distribution location-routing system is feasible and effective for the cold-chain logistics network, and can decrease distribution cost for cold-chain logistics enterprises.

scholarly journals A Method for Transportation Planning and Profit Sharing in Collaborative Multi-Carrier Vehicle Routing

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1788
Author(s):  
Yanjun Shi ◽  
Na Lin ◽  
Qiaomei Han ◽  
Tongliang Zhang ◽  
Weiming Shen
Keyword(s):  
Vehicle Routing ◽  
Shapley Value ◽  
Vehicle Routing Problem ◽  
Transportation Planning ◽  
Hybrid Genetic Algorithm ◽  
Profit Sharing ◽  
Planning Problem ◽  
Routing Problem ◽  
Heuristics Algorithm ◽  
Carrier Vehicle

This paper addresses a collaborative multi-carrier vehicle routing problem (CMCVRP) where carriers tackle their orders collaboratively to reduce transportation costs. First, a hierarchical heuristics algorithm is proposed to solve the transportation planning problem. This algorithm makes order assignments based on two distance rules and solves the vehicle routing problem with a hybrid genetic algorithm. Second, the profit arising from the coalition is quantified, and an improved Shapley value method is proposed to distribute the profit fairly to individual players. Extensive experiment results showed the effectiveness of the proposed hierarchical heuristics algorithm and confirmed the stability and fairness of the improved Shapley value method.

scholarly journals Ensuring Reliable Operation of Electricity Grid by Placement of FACTS Devices for Developing Countries

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2283
Author(s):  
Atif Naveed Khan ◽  
Kashif Imran ◽  
Muhammad Nadeem ◽  
Anamitra Pal ◽  
Abraiz Khattak ◽  
...  
Keyword(s):  
Developing Countries ◽  
Reactive Power ◽  
Operating Cost ◽  
Active Power ◽  
System Stability ◽  
Planning Problem ◽  
Power Losses ◽  
Reliable Operation ◽  
Electricity Grid ◽  
Facts Devices

Flexible AC Transmission Systems (FACTS) are essential devices used for the efficient performance of modern power systems and many developing countries lack these devices. Due to the non-existence of these advanced technologies, the national grid remains weak and vulnerable to power stability issues that can jeopardize system stability. This study proposes novel research to solve issues of an evolving national grid through the installation of FACTS devices. FACTS devices play a crucial role in minimizing active power losses while managing reactive power flows to keep the voltages within their respective limits. Due to the high costs of FACTS, optimization must be done to discover optimal locations as well as ratings of these devices. However, due to the nonlinearity, it is a challenging task to find the optimal locations and appropriate sizes of these devices. Shunt VARs Compensators (SVCs) and Thyristor-Controlled Series Compensators (TCSCs) are the two FACTS devices considered for the study. Optimal locations for SVCs and TCSCs are determined by Voltage Collapse Proximity Index (VCPI) and Line Stability Index (Lmn), respectively. Particle Swarm Optimization (PSO) is employed to find the ideal rating for FACTS devices to minimize the system operating cost (cost due to active power loss and capital cost of FACTS devices). This technique is applied to IEEE (14 and 30) bus systems. Moreover, reliable operation of the electricity grid through the placement of FACTS for developing countries has also been analysed; Pakistan being a developing country has been selected as a case study. The planning problem has been solved for the present as well as for the forecasted power system. Consequently, in the current national network, 6.21% and 6.71% reduction in active and reactive power losses have been observed, respectively. Moreover, voltage profiles have been improved significantly. A detailed financial analysis covering the calculation of Operation Cost (OC) of the national grid before and after the placement of FACTS devices is carried out.

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