Hybrid Simulated Annealing Algorithm Research Articles

A hybrid metaheuristic algorithm for scheduling iron ore reclaiming in ports

ABSTRACT This work deals with a scheduling problem of reclaimers. This problem involves a set of ships to be loaded with predefined stockpiles. These stockpiles are unloaded into ship holds, and each hold must store a predefined product and quantity of iron ore. Stockpiles are stored in storage yards, which have reclaimers to reclaim iron ore from stockpiles and send it to berthed ships. The objective is to schedule the operations of reclaimers to minimize the sum of ships' berthing times. A hybrid algorithm, combining the multi-start, GRASP and variable neighbourhood descent procedures, is proposed to treat instances of any scale of the problem. It was tested in real instances, and its results were compared with the hybrid simulated annealing algorithm from the literature and a fast simulation algorithm that emulates operators' decision-making. The proposed algorithm was the best in all instances, and statistical tests proved its superiority

Economic optimization of fresh logistics pick-up routing problems with time windows based on gray prediction

The rapid development of modern cold chain logistics technology has greatly expanded the sales market of agricultural products in rural areas. However, due to the uncertainty of agricultural product harvesting, relying on the experience values provided by farmers for vehicle scheduling can easily lead to low utilization of vehicle capacity during the pickup process and generate more transportation cost. Therefore, this article adopts a non-linear improved grey prediction method based on data transformation to estimate the pickup demand of fresh agricultural products, and then establishes a mathematical model that considers the fixed vehicle usage cost, the damage cost caused by non-linear fresh fruit and vegetable transportation damage and decay rate, the cooling cost generated by refrigerated transportation, and the time window penalty cost. In order to solve the model, a hybrid simulated annealing algorithm integrating genetic operators was designed to solve this problem. This hybrid algorithm combines local search strategies such as the selection operator without repeated strings and the crossover operator that preserves the best substring to improve the algorithm’s solving performance. Numerical experiments were conducted through a set of benchmark examples, and the results showed that the proposed algorithm can adapt to problem instances of different scales. In 50 customer examples, the difference between the algorithm and the standard value in this paper is 2.30%, which is 7.29% higher than C&S. Finally, the effectiveness of the grey prediction freight path optimization model was verified through a practical case simulation analysis, achieving a logistics cost savings of 9.73%.

Resource allocation and route planning under the collection price uncertainty for the biomass supply chain

The escalating severity of global warming has drawn worldwide attention to ecological problems. Nevertheless, with the introduction of environmental policies, biomass resources have been effectively developed as a renewable energy source. This paper investigates an advanced biomass supply chain design wherein biomass resources are initially converted into bio-oil through widely distributed fast pyrolysis facilities, and are subsequently transported to a centralised biorefinery for further refining into biofuels. This novel biomass supply chain addressed three key issues: (1) The number of fast pyrolysis facilities, (2) The allocation of resources, and (3) The routes of resources transport. In respect of these problems, a two-stage stochastic mixed integer programming model is established to minimise the total cost of the biomass supply chain considering the uncertainty collection price of fast pyrolysis facilities. A hybrid simulated annealing algorithm which incorporates the sample average approximation method is proposed to solve the stochastic model and is effectiveness for large-scale examples. Finally, a sensitivity analysis is performed using the proposed algorithm and the results show that the proposed stochastic model outperforms the deterministic model under uncertain collection price. The model allows optimising the biomass supply chain economic performances and minimise financial risk on investment by determining the fast pyrolysis facility locations, reasonable resource allocation and optimal transport routes under uncertain collection price.

Continuous Space Wireless Communication Tower Placement by Hybrid Simulated Annealing

Wireless communication tower placement arises in many real-world applications. This paper investigates a new emerging wireless communication tower placement problem, namely, continuous space wireless communication tower placement. Unlike existing wireless communication tower placement problems, which are discrete computational problems, this new wireless communication tower placement problem is a continuous space computational problem. In this paper, we formulate the new wireless communication tower placement problem and propose a hybrid simulated annealing algorithm that can take advantage of the powerful exploration capacity of simulated annealing and the strong exploitation capacity of a local optimization procedure. We also demonstrate through experiments the effectiveness of this hybridization technique and the good performance and scalability of the hybrid simulated annulling in this paper.

Accurate solution of the Index Tracking problem with a hybrid simulated annealing algorithm

An actively managed portfolio almost never beats the market in the long term. Thus, many investors often resort to passively managed portfolios whose aim is to follow a certain financial index. The task of building such passive portfolios aiming also to minimize the transaction costs is called Index Tracking (IT), where the goal is to track the index by holding only a small subset of assets in the index. As such, it is an NP-hard problem and becomes unfeasible to solve exactly for indices with more than 100 assets. In this work, we present a novel hybrid simulated annealing method that can efficiently solve the IT problem for large indices and is flexible enough to adapt to financially relevant constraints. By tracking the S&P-500 index between the years 2011 and 2018 we show that our algorithm is capable of finding optimal solutions in the in-sample period of past returns and can be tuned to provide optimal returns in the out-of-sample period of future returns. Finally, we focus on the task of holding an IT portfolio during one year and rebalancing the portfolio every month. Here, our hybrid simulated annealing algorithm is capable of producing financially optimal portfolios already for small subsets of assets and using reasonable computational resources, making it an appropriate tool for financial managers.

Construction of Cloud Computing Task Scheduling Model Based on Simulated Annealing Hybrid Algorithm

Construction of Cloud Computing Task Scheduling Model Based on Simulated Annealing Hybrid Algorithm

A novel hybrid simulated annealing algorithm for colored bottleneck traveling salesman problem

In the fields, such as intelligent transport and multiple tasks cooperation, many real-world problems can be modeled by colored bottleneck traveling salesman problem (CBTSP). Since CBTSP has been proved belong to the NP-hard problems, the population-based algorithms, such as genetic algorithm (GA), hill climbing GA (HCGA) and simulated annealing GA (SAGA), have been used for solving it. However, in term of convergence speed and solution quality, their performances are limited. Moreover, some intelligent algorithms still have the problems such as “black box problem” or lacking theoretical support. Aiming at these problems, this paper proposes a new hybrid simulated annealing algorithm with generating neighborhood solution and crossover operator (GCSA) for CBTSP. In the iterative process of GCSA, the gene coding (dual-chromosome coding) is used to code feasible solutions, and the improved generating neighborhood solution and crossover operator by ITÖ lemma (Wiener process) are used to explore and exploit new unknown region. During the process, generating neighborhood solution and crossover operator are both controlled by the activity intensity based on Wiener process. The experiments show that GCSA can demonstrate an improvement over the state-of-the-art algorithms for this problem.

Heterogeneous Mission Planning for Multiple UAV Formations via Metaheuristic Algorithms

Unmanned aerial vehicle (UAV) formation has been widely applied in various aspects, both for military and civil purposes. In this paper, multiple UAV formations are deployed to perform different types of tasks, and the heterogeneous mission planning problem is studied. The problem is divided into two subproblems, i.e., task assignment and path planning. First, the task assignment is formulated into a combinatorial optimization problem. Different from the existing studies, appropriate UAVs need to be selected to build the formation and perform specific types of tasks. To obtain the task assignment scheme, a hybrid genetic and simulated annealing (HGSA) algorithm is proposed. In this algorithm, a feasible solution is guaranteed by the designed task-based strategy, and the diversity of solutions is ensured by the group-based solution remaining (GBSR) approach. In the path planning problem, an obstacle avoidance-enabled consensus (OAEC) algorithm is developed to form the UAV formation, which extends the application of the standard consensus algorithm. A multi-step particle swarm optimization (MPSO) algorithm is combined with the consensus algorithm to generate a path for the UAV formation to reach each task point. The conflict among multiple UAV formations is resolved by adjusting their departure time. Furthermore, the task assignment scheme is modified by utilizing real path information on the flying distance between the UAVs and the task points. The simulation results demonstrate that the HGSA algorithm can build the UAV formations and assign the tasks to them while satisfying all the complicated constraints. The advantages of the OAEC algorithm and the MPSO algorithm in path planning are verified by comparison with relevant algorithms.

A hybrid simulated annealing and variable neighborhood search algorithm for the close-open electric vehicle routing problem

AbstractElectric Vehicles (EVs) are the future of transportation, but due to their battery and charging technology they cannot yet directly replace traditional vehicles. Nonetheless, EVs are a great option for city-logistics, due to the small distances and their zero local emissions. In this paper, a novel variant of the Electric Vehicle Routing Problem (EVRP), called Close-Open EVRP (COEVRP), is presented. It considers ending EV trips at Charging Stations, as opposed to other EVRP variants that only allow for en-route charging. This new variant follows a traditional routing scheme, allowing EVs to recharge only at the end of their route. The objective is to minimize energy consumption, as well as the number of vehicles. The energy consumption function takes into account the weight of the transported items. A mathematical formulation for the problem is presented and small instances were solved using a commercial solver. To solve larger instances, a hybrid metaheuristic combining Simulated Annealing and Variable Neighborhood Search algorithm was employed and thoroughly tested.

Two-Layer Location-Routing Problem Based on Heuristic Hybrid Algorithm

Location-routing problem (LRP) thoroughly considers location allocation problem (LAP) and vehicle routing problem (VRP) which has been an integral part applied in modern logistics. A number of researchers at home and aboard have put forward their views by establishing fine models. On the basis of studying the previous research results by classification, summary, and comparative analysis, this study hence proposes a new solution-fuzzy clustering model and algorithm to resolve two-layer location-routing problem based on a heuristic hybrid algorithm: Designing a hybrid genetic and simulated annealing algorithm (GASA) to optimize the initial value of the fuzzy C-means clustering algorithm (FCM); considering the roving visit characteristics of vehicles to design the path by employing a special VRP problem—the multiple traveling salesman problem (MTSP). Theoretical analysis and experimental results show that the algorithm used in this study has the advantages of fast convergence speed and less iterations, which significantly improve the quality of the initial solution of FCM in LAP, shorten the vehicle patrol cycle in VRP to a great extent, improve the vehicle utilization, and save the vehicle patrol costs. A specific example is programmed by MATLAB to verify the feasibility of this method.

A sustainable and resilient supply chain (RS-SCM) by using synchronisation and load-sharing approach: application in the oil and gas refinery

Nowadays sustainable and resilient supply chain management (R&S-SCM) is an interesting and in the meantime vital problem that has grabbed the attention of many researchers. This study is an effort to investigate the simultaneous design of sustainable and resilient flow in the supply chain. To achieve a sustainable and resilient supply chain, there is a wide variety of strategies depending on their impacts on different industries and the features of their supply chain. The fuzzy QFD method is designed to select the most appropriate strategy in the study. Two approaches are used for this purpose. Early planning in sustainable mode is formulated assuming that all members of the network are healthy and final planning in the reactive approach to destruction which formulates the return to the original state in the shortest possible time, cost and scenario-based status. A hybrid priority-based Genetic Algorithm (pb-GA) and simulated annealing algorithm (SA) is developed in two phases to find the optimal solutions. Response Surface Methodology (RSM) method is used to adjust significant parameters for the algorithm. Several test problems are generated showing that the proposed metaheuristic algorithm can find good solutions in reasonable time spans.

A hybrid simulated annealing algorithm to estimate a better upper bound of the minimal total cost of a transportation problem with varying demands and supplies

Minimizing the total cost of transportation of a homogeneous product from multiple sources to multiple destinations when demand at each source and supply at each destination are deterministic and constant is commonly addressed in the literature. However, in practice, demand and supply may fluctuate within a certain range due to variations of the global economy. Subsequently, finding the upper bound of the minimal total cost of this transportation problem with varying demands and supplies (TPVDS) is NP hard. Yet, bounding the minimal total cost is of prime importance for financial sustainability. Although the lower bound of the minimal total cost can be methodologically attained, determining the exact upper bound is challenging. Herein, we demonstrate that existing methods may underestimate this upper minimal total cost bound. We therefore propose an alternative efficient and robust method that is based on the hybridization of simulated annealing and steepest descent. We provide theoretical evidence of its good performance in terms of solution quality and prove its superiority in comparison to existing techniques. We further validate its performance on benchmark and newly generated instances. Finally, we exemplify its utility on a real-world TPVDS.

Slow Heat-Based Hybrid Simulated Annealing Algorithm in Vehicular Ad Hoc Network.

Vehicular ad hoc networks (VANETs) using reliable protocols of routing have become crucial in identifying the changes to topology on a continuous basis for a large collection of vehicles. For this purpose, it becomes important to identify an optimal configuration of these protocols. There are several possible configurations that have been preventing the configuration of efficient protocols that do not make use of automatic and intelligent design tools. It can further motivate using the techniques of metaheuristics like the tools, which are well-suited to be able to solve these problems. The glowworm swarm optimization (GSO), simulated annealing (SA), and slow heat-based SA-GSO algorithms have been proposed in this work. The SA is a method of optimization, which imitates the manner in which the thermal system has been frozen down to its lowest state of energy. In the GSO, there is guidance to the rules of feasibility, where the swarm converges to its feasible regions very fast. Additionally, for overcoming any premature convergence, there is a local search strategy that is based on the SA and is used for making a search that is near to its true optimum solutions. Finally, this sluggish temperature-based SA-GSO algorithm will be employed to solve routing problems and problems of heat transfer. There is a hybrid slow heat SA-GSO algorithm with a faster speed of convergence and higher precision of computation that is more effective in solving problems of constrained engineering.

A Novel Hybrid Simulated Annealing for No-Wait Open-Shop Surgical Case Scheduling Problems

In this paper, the problem of finding an assignment of “n” surgeries to be presented in one of “m” identical operating rooms (ORs) or machines as the surgical case scheduling problem (SCSP) is proposed. Since ORs are among NP-hard optimization problems, mathematical and metaheuristic methods to address OR optimization problems are used. The job or surgical operation ordering in any OR is a permanent part of all sequencing and scheduling problems. The transportation times between ORs are defined based on the type of surgical operations and do not depend on distance, so there is no surgical operation waiting time for transferring. These problems are called no-wait open-shop scheduling problems (NWOSP) with transportation times. The transportation system for the problems is considered a multi-transportation system with no limitation on the number of transportation devices. Accordingly, this study modeled a novel combined no-wait open-shop surgical case scheduling problem (NWOSP-SCSP) with multi-transportation times for the first time to minimize the maximum percentile of makespan for OR as a single objective model. A mixed-integer linear program (MILP) with small-sized instances is solved. In addition to the small-sized model, a novel metaheuristic based on a hybrid simulated annealing (SA) algorithm to solve large-sized problems in an acceptable computational time is suggested, considering the comparison of the SA algorithm and a new recommended heuristic algorithm. Then, the proposed hybrid SA and SA algorithms are compared based on their performance measurement. After reaching the results with a numerical analysis in Nova Scotia health authority hospitals and health centers, the hybrid SA algorithm has generated significantly higher performance than the SA algorithm.

Graded Optimization of Upper Limb Exoskeleton Parts for Grid Operations

Upper limb exoskeleton is gradually used in industrial production because of its flexibility, safety, and ease of wear. To improve the load reduction effect of the upper limb exoskeleton in power grid operation, this paper first establishes an efficiency optimization model considering the number of gears, transmission ratio, and pressure angle of upper limb exoskeleton transmission joint gears. Further, an exoskeleton load reduction model based on the joint optimization of multiple parameters of the upper limb exoskeleton is constructed by combining the muscle force application fatigue evaluation. For the above model, a hybrid simulated annealing-flash connection process algorithm based on Cubic mapping and golden sine is designed for the solution. To address the shortcomings of the standard LAPO, Cubic mapping, simulated annealing algorithm, and golden sine operator are introduced for improvement, producing high-quality initial solutions through the traversal of Cubic chaotic sequences, hybrid simulated annealing algorithm to enhance the global search capability of the algorithm, and further incorporating golden sine operator to strengthen the local search capability of the algorithm. In the simulation section, the designed Improved Lightning Connection Process Algorithm (ILAPO) is compared horizontally with cutting-edge swarm intelligence algorithms such as LAPO, PSO, and HBA to verify the feasibility of the model in this paper in the exoskeleton domain and the efficiency of the designed algorithm.

Heuristic position allocation methods for forming multiple UAV formations

It is a common action that the unmanned aerial vehicles (UAVs) change the formation during the flight to realize different goals and address an emergency. In this process, the UAVs should determine their positions in the new formation to avoid the collision and reduce the flight time. In this paper, the position allocation problem for multiple UAV formations is studied, and the problem is solved considering the different requirements on offline and online cases. In the offline case, the trajectories of UAVs when forming new formations are calculated by the consensus-based trajectory planning (CBTP) method, in which the transient process is introduced to avoid the collision among UAVs. Then a hybrid genetic and simulated annealing (HGSA) algorithm, which utilizes the framework of genetic algorithm (GA) and the operators in simulated annealing (SA) algorithm, is proposed to obtain the optimal position allocation scheme. The CBTP method is treated as a part of the HGSA algorithm to calculate the optimization index for a specific position allocation scheme. In the online case, a two-step minimal cost increase strategy (MCIS)-based method is developed and the UAVs in each new formation and the allocated position of UAV in the new formation are determined successively. Simulation results demonstrate that the CBTP method can generate the safe trajectories for the UAVs when forming new formations, and the optimal position allocation scheme can be obtained by the HGSA algorithm. The HGSA algorithm performs better than other similar algorithms especially in the complicated situation. The MCIS-based method can output the partially optimized position allocation scheme at short notice, but the real trajectories of UAVs are not considered in the online case to reduce the computation time.

Harmonic Detection Method Based on Particle Swarm Optimization and Simulated Annealing Algorithm of Electrohydraulic Servo System

Due to the comprehensive influence of many nonlinear coupling factors within a system, when the input signal provided by an electrohydraulic servo shaker is sinusoidal, it often leads to the existence of high-order harmonic components of the system, which makes the output servo signal parameters exist extremely serious. Therefore, the detection of harmonics of the electrohydraulic servo shaker has very important application significance. In this paper, by using simulated annealing (SA) based harmonic detection, a kernel function is introduced to study area influence-based particle swarm optimization (PSO). Using a super accurate and fast global convergence brought by the combination of hybrid particle swarm optimization algorithm and simulated annealing algorithm, it can quickly jump out of the trap of traditional local optimization algorithms and a more stable, high-precision, as well as fast global convergence optimal solution can be obtained. Through the detection and simulation of the amplitude and phase of the harmonics in the system, by comparing the PSO-SA detection with PSO detection, it is proved that the PSO-SA algorithm can well satisfy the accuracy of the detection system, which has advantages such as a fast convergence speed, a high search accuracy, etc.; meanwhile, it is simple and easy to implement.

Cascade refrigeration system synthesis based on hybrid simulated annealing and particle swarm optimization algorithm

Cascade refrigeration system (CRS) can meet a wider range of refrigeration temperature requirements and is more energy efficient than single-refrigerant refrigeration system, making it more widely used in low-temperature industry processes. The synthesis of a CRS with simultaneous consideration of heat integration between refrigerant and process streams is challenging but promising for significant cost saving and reduction of carbon emission. This study presented a stochastic optimization method for the synthesis of CRS. An MINLP model was formulated based on the superstructure developed for the CRS, and an optimization framework was proposed, where simulated annealing algorithm was used to evolve the numbers of pressure/temperature levels for all sub-refrigeration systems, and particle swarm optimization algorithm was employed to optimize the continuous variables. The effectiveness of the proposed methodology was verified by a case study of CRS optimization in an ethylene plant with 21.89% the total annual cost saving.

Non-isothermal pyrolysis of xylan, cellulose and lignin: A hybrid simulated annealing algorithm and pattern search method to regulate distributed activation energies

Biomass transformation into fuels, platform chemicals and materials contributes to developing sustainability and carbon neutralization. Pyrolysis is one of the most important approaches to valorize biomass. The distributed activation energy model (DAEM) is a comprehensive kinetic model for describing biomass pyrolysis kinetics. The estimation of the DAEM parameters is difficult because of the complex structure of the DAEM equation. This work formulated the numerical calculation approach of the DAEM and proposed a hybrid simulated annealing (SA) algorithm and pattern search (PS) method for optimizing the DAEM parameters. The DAEM kinetic parameters were evaluated by simultaneously fitting the experimental kinetic data of cellulose, xylan and lignin pyrolysis at various heating rates with the DAEM using the proposed hybrid optimization method. The results showed that the proposed hybrid optimization method could effectively and accurately determine the DAEM parameters and the DAEM with the optimal parameters could reproduce the experimental kinetic data of xylan, cellulose and lignin pyrolysis very well. The distributed activation energies of xylan, cellulose and lignin predicted by hybrid optimization were centered at 162.8, 222.8 and 236.7 kJ mol−1, respectively, with standard deviations of 4.6, 0.8 and 25.9 kJ mol−1, respectively. The reaction orders of xylan, cellulose and lignin pyrolysis are 1.7, 1.1, and 2.5, respectively.

Cross-regional manpower scheduling and routing problem with stochastic service times in home health care

At present, home health care services supply is still insufficient and unbalanced in China, and the elderly nursing manpower is particularly scarce. Therefore, it is important to reasonably arrange the existing nursing personnel to make full use of the service capabilities. This paper proposes a mixed integer linear programming (MILP) model for a cross-regional scheduling and routing problem with stochastic service times in the one-day planning horizon. A range of possible realistic constraints are considered, including patient time windows, working time regulations, task importance, and skill matching. Due to the complexity of the problem, a hybrid Simulated Annealing algorithm is introduced to solve the model. Monte Carlo simulation method is used for the uncertainty cost evaluation. The numerical example tests verify the effectiveness of the algorithm proposed. This paper analyzes the advantages and disadvantages of cross-regional scheduling and routing by comparing the empirical experiment results of the cross-regional and independent scheduling of two regions. It is found that in the case of this paper, cross-regional scheduling is generally beneficial to reducing the cost of both care centers and improving the efficiency of resource utilization.