The fossil fuel powered mining truck fleets can contribute up to 80%of total emissions in open pit mines.This study investigates the optimal decarbonisation pathway for mining truck fleets.Notably,our proposed pathway...The fossil fuel powered mining truck fleets can contribute up to 80%of total emissions in open pit mines.This study investigates the optimal decarbonisation pathway for mining truck fleets.Notably,our proposed pathway incorporates power generation,negative carbon technologies,and carbon trading.Technical,financial,and environmental models of decarbonisation technologies are established,capturing regional variations and time dynamic characteristics such as cost trends and carbon capture efficiency.The dynamic natures of characteristics pose challenges for using the cost-effective analyses approach to find the optimal decarbonisation pathway.To address this,we introduce a mixed-integer programming optimisation framework to find the decarbonisation pathway with minimum life cycle costs during the planning period.A case study for the optimal decarbonisation pathway of truck fleets in a South African coal mine is conducted to illustrate the applicability of the proposed model.Results indicate that the optimal decarbonisation pathway is significantly influenced by factors such as land cost,annual budget,and carbon trading prices.The proposed method provides invaluable guidance for transitioning towards a cleaner and more sustainable mining industry.展开更多
In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,...In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,and the speed control model is proposed from the perspective of vehicles themselves,to obtain a stable fleet with the same distance and speed.However,in this process,the initial condition of the vehicle,the traffic flow environment,and the efficiency of the fleet formation are less considered.Therefore,based on summarizing the existing fleet building model,this paper puts forward the rapid construction model and algorithm of a cooperative adaptive cruise control platoon fleet.One of the important goals of forming a team is to enter the team with the smoothest trajectory in the shortest time.Therefore,this chapter studies the trajectory optimization of the vehicle formation process from the perspective of vehicle dynamics.展开更多
A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The mainte- nance process of an aircraft fleet...A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The mainte- nance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system （MAS） model. A com- munication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol （CNP）. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.展开更多
Allocation of fleet's spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship's service level highly relies on the maintenance logistics' level. I...Allocation of fleet's spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship's service level highly relies on the maintenance logistics' level. In this study, the readiness ratio is proposed as a critical index in measuring the system's reliability. A well-established mathematical model adopting the optimization method of spare part allocation is also introduced. The objective is to minimize the number of each spare part while satisfying the fleet's system reliability. The fault tree analysis(FTA) is applied to analyze the system's failure logic and stratify the units on ship. As a result, the strategy of spare part sharing can be introduced in detail. The solution algorithm is developed, and the simulation experiments to obtain the key parameters are conducted. The proposed model and algorithm are applied to an actual fleet of two warships, and results show that the method above is feasible and can be directly applied into practice.展开更多
Reducing the operation and maintenance (O & M) cost is one of the potential actions that could reduce the cost of energy produced by offshore wind farms. This article attempts to reduce O & M cost by improving...Reducing the operation and maintenance (O & M) cost is one of the potential actions that could reduce the cost of energy produced by offshore wind farms. This article attempts to reduce O & M cost by improving the utilization of the maintenance resources, specifically the efficient scheduling and routing of the maintenance fleet. Scheduling and routing of maintenance fleet is a non-linear optimization problem with high complexity and a number of constraints. A heuristic algorithm, Ant Colony Optimization (ACO), was modified as Multi-ACO to be used to find the optimal scheduling and routing of maintenance fleet. The numerical studies showed that the proposed methodology was effective and robust enough to find the optimal solution even if the number of offshore wind turbine increases. The suggested approaches are helpful to avoid a time-consuming process of manually planning the scheduling and routing with a presumably suboptimal outcome.展开更多
This article introduces a fleet composition algorithm for a fleet of intermediate carriers, which should deliver a swarm of miniature unmanned aerial vehicles （mini-UAVs） to a mission area. The algorithm is based on...This article introduces a fleet composition algorithm for a fleet of intermediate carriers, which should deliver a swarm of miniature unmanned aerial vehicles （mini-UAVs） to a mission area. The algorithm is based on the sequential solution of several knapsack problems with various constraints. The algorithm allows both to form an initial set of required types of intermediate carriers, and to generate a fleet of intermediate carriers. The formation of a fleet of intermediate carriers to solve a suppression of enemy air defense （SEAD） problem is presented to illustrate the proposed algorithm.展开更多
In order to facilitate the scientific management of large-sized shipping companies, fleet planning under complicated circumstances has been studied. Based on multiple influencing factors such as the techno-economic st...In order to facilitate the scientific management of large-sized shipping companies, fleet planning under complicated circumstances has been studied. Based on multiple influencing factors such as the techno-economic status of ships, the investment capacity of company, the possible purchase of new ships, the buying/selling of second-hand vessels and the chartering/renting of ships, a mixed-integer programming model for fleet planning has been established. A large-sized shipping company is utilized to make an empirical study, and Benders decomposition algorithm is employed to test the applicability of the proposed model. The result shows that the model is capable for multi-route, multi-ship and large-scaled fleet planning and thus helpful to support the decision making of large-sized shipping companies.展开更多
A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a...A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a good schedule was obtained as the current best schedule by searching in this domain.Then,progressively narrower neighborhood search domains were constructed around the current best schedule to search for better schedules.The objective is to minimize the present value of waste removal costs over the mine life.The resulting schedule from this algorithm provides a complete fleet profile for each year over the mine life:the selected equipment models,the number of equipment units of each model,the age of each unit,as well as the quantity of waste removed.A numerical example of application was provided to demonstrate the feasibility and merits of the algorithm.展开更多
A 0-1 integer programming model for weekly fleet assignment was put forward based on linear network and weekly flight scheduling in China. In this model, the objective function is to maximize the total profit of fleet...A 0-1 integer programming model for weekly fleet assignment was put forward based on linear network and weekly flight scheduling in China. In this model, the objective function is to maximize the total profit of fleet assignment, subject to the constraints of coverage, aircraft flow balance, fleet size, aircraft availability, aircraft usage, flight restriction, aircraft seat capacity, and stopover. Then the branch-and-bound algorithm based on special ordered set was applied to solve the model. At last, a real- wofld case study on an airline with 5 fleets, 48 aircrafts and 1 786 flight legs indicated that the profit increase was ￥ 1 591276 one week and the running time was no more than 4 rain, which shows that the model and algorithm are fairly good for domestic airline.展开更多
The main objective of the study was to examine the influence of vehicle fleet management practices on service delivery in State-Owned Enterprises (SOEs) in Zimbabwe. The study adopted a pragmatism research philosophy ...The main objective of the study was to examine the influence of vehicle fleet management practices on service delivery in State-Owned Enterprises (SOEs) in Zimbabwe. The study adopted a pragmatism research philosophy together with a mixed method research paradigm. In addition, structured questionnaires were distributed to 344 respondents drawn from 86 SOEs. Stratified and purposive sampling was used. Descriptive statistics were calculated using Statistical Package for the Social Science (SPSS) version 20. Exploratory factor analysis (EFA) was done on all items of the study while research hypotheses were tested using Structural Equation Modelling (SEM) in AMOS version 21. The study concluded that vehicle maintenance, fuel management, driver management and vehicle replacement positively influence service delivery. In addition, the study also established that Information and Communication Technologies (ICTs) moderate the influence of vehicle fleet management practices on service delivery. The study recommended that there is need for regular driver training and vehicle programs encompassing electronic spares tracking.展开更多
As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative ...As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method.展开更多
The past decade has witnessed a huge increase in the number of proposed middleware solutions for robotic fleets operating in unstructured environments. As a result, it has become difficult to decide which middleware i...The past decade has witnessed a huge increase in the number of proposed middleware solutions for robotic fleets operating in unstructured environments. As a result, it has become difficult to decide which middleware is the most appropriate for a specific application or application domain. In this paper we first extract a set of common and specific challenges that middlewares address, and group them according to the source domain they have originated within. These challenges are derived from a specific precision agriculture use-case based on the robotic fleet for weed control elaborated within the European project RHEA-robot fleets for highly effective agriculture and forestry management. Furthermore, the paper provides an analysis of a number of different middlewares and suggests a set of criteria for systemizing representative solutions. The aim of this analysis is to assist the process of finding an adequate middleware for a specific application domain.展开更多
基金National Key R&D Program of China(Grant No.2021YFE0199000)National Natural Science Foundation of China(Grant No.62133015)National Research Foundation China/South Africa Research Cooperation Programme with Grant No.148762,and Royal Academy of Engineering Transforming Systems through Partnership grant scheme with reference No.TSP2021\100016.
文摘The fossil fuel powered mining truck fleets can contribute up to 80%of total emissions in open pit mines.This study investigates the optimal decarbonisation pathway for mining truck fleets.Notably,our proposed pathway incorporates power generation,negative carbon technologies,and carbon trading.Technical,financial,and environmental models of decarbonisation technologies are established,capturing regional variations and time dynamic characteristics such as cost trends and carbon capture efficiency.The dynamic natures of characteristics pose challenges for using the cost-effective analyses approach to find the optimal decarbonisation pathway.To address this,we introduce a mixed-integer programming optimisation framework to find the decarbonisation pathway with minimum life cycle costs during the planning period.A case study for the optimal decarbonisation pathway of truck fleets in a South African coal mine is conducted to illustrate the applicability of the proposed model.Results indicate that the optimal decarbonisation pathway is significantly influenced by factors such as land cost,annual budget,and carbon trading prices.The proposed method provides invaluable guidance for transitioning towards a cleaner and more sustainable mining industry.
文摘In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,and the speed control model is proposed from the perspective of vehicles themselves,to obtain a stable fleet with the same distance and speed.However,in this process,the initial condition of the vehicle,the traffic flow environment,and the efficiency of the fleet formation are less considered.Therefore,based on summarizing the existing fleet building model,this paper puts forward the rapid construction model and algorithm of a cooperative adaptive cruise control platoon fleet.One of the important goals of forming a team is to enter the team with the smoothest trajectory in the shortest time.Therefore,this chapter studies the trajectory optimization of the vehicle formation process from the perspective of vehicle dynamics.
文摘A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The mainte- nance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system （MAS） model. A com- munication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol （CNP）. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.
文摘Allocation of fleet's spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship's service level highly relies on the maintenance logistics' level. In this study, the readiness ratio is proposed as a critical index in measuring the system's reliability. A well-established mathematical model adopting the optimization method of spare part allocation is also introduced. The objective is to minimize the number of each spare part while satisfying the fleet's system reliability. The fault tree analysis(FTA) is applied to analyze the system's failure logic and stratify the units on ship. As a result, the strategy of spare part sharing can be introduced in detail. The solution algorithm is developed, and the simulation experiments to obtain the key parameters are conducted. The proposed model and algorithm are applied to an actual fleet of two warships, and results show that the method above is feasible and can be directly applied into practice.
文摘Reducing the operation and maintenance (O & M) cost is one of the potential actions that could reduce the cost of energy produced by offshore wind farms. This article attempts to reduce O & M cost by improving the utilization of the maintenance resources, specifically the efficient scheduling and routing of the maintenance fleet. Scheduling and routing of maintenance fleet is a non-linear optimization problem with high complexity and a number of constraints. A heuristic algorithm, Ant Colony Optimization (ACO), was modified as Multi-ACO to be used to find the optimal scheduling and routing of maintenance fleet. The numerical studies showed that the proposed methodology was effective and robust enough to find the optimal solution even if the number of offshore wind turbine increases. The suggested approaches are helpful to avoid a time-consuming process of manually planning the scheduling and routing with a presumably suboptimal outcome.
基金supported by the National Natural Science Foundation of China(60774064)the Aerospace Science Foundation (20085153015)
文摘This article introduces a fleet composition algorithm for a fleet of intermediate carriers, which should deliver a swarm of miniature unmanned aerial vehicles （mini-UAVs） to a mission area. The algorithm is based on the sequential solution of several knapsack problems with various constraints. The algorithm allows both to form an initial set of required types of intermediate carriers, and to generate a fleet of intermediate carriers. The formation of a fleet of intermediate carriers to solve a suppression of enemy air defense （SEAD） problem is presented to illustrate the proposed algorithm.
基金the Doctoral Programs Foundation ofMinistry of Education of China(No.20102125110002)
文摘In order to facilitate the scientific management of large-sized shipping companies, fleet planning under complicated circumstances has been studied. Based on multiple influencing factors such as the techno-economic status of ships, the investment capacity of company, the possible purchase of new ships, the buying/selling of second-hand vessels and the chartering/renting of ships, a mixed-integer programming model for fleet planning has been established. A large-sized shipping company is utilized to make an empirical study, and Benders decomposition algorithm is employed to test the applicability of the proposed model. The result shows that the model is capable for multi-route, multi-ship and large-scaled fleet planning and thus helpful to support the decision making of large-sized shipping companies.
基金Projects(51474049,51674062)supported by the National Natural Science Foundation of ChinaProject(51604061)supported by the National Science Foundation for Young Scientists of China+3 种基金Projects(201202075,2014020040)supported by the Liaoning Natural Science Founds,ChinaProject(LZ2014020)supported by the Liaoning Province’s Key Laboratory Construction,ChinaProject(20130042110012)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(F14-231-1-07)supported by the Shenyang Technical Plan Project,China
文摘A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a good schedule was obtained as the current best schedule by searching in this domain.Then,progressively narrower neighborhood search domains were constructed around the current best schedule to search for better schedules.The objective is to minimize the present value of waste removal costs over the mine life.The resulting schedule from this algorithm provides a complete fleet profile for each year over the mine life:the selected equipment models,the number of equipment units of each model,the age of each unit,as well as the quantity of waste removed.A numerical example of application was provided to demonstrate the feasibility and merits of the algorithm.
基金The National Natural Science Foundationof China (70473037)
文摘A 0-1 integer programming model for weekly fleet assignment was put forward based on linear network and weekly flight scheduling in China. In this model, the objective function is to maximize the total profit of fleet assignment, subject to the constraints of coverage, aircraft flow balance, fleet size, aircraft availability, aircraft usage, flight restriction, aircraft seat capacity, and stopover. Then the branch-and-bound algorithm based on special ordered set was applied to solve the model. At last, a real- wofld case study on an airline with 5 fleets, 48 aircrafts and 1 786 flight legs indicated that the profit increase was ￥ 1 591276 one week and the running time was no more than 4 rain, which shows that the model and algorithm are fairly good for domestic airline.
文摘The main objective of the study was to examine the influence of vehicle fleet management practices on service delivery in State-Owned Enterprises (SOEs) in Zimbabwe. The study adopted a pragmatism research philosophy together with a mixed method research paradigm. In addition, structured questionnaires were distributed to 344 respondents drawn from 86 SOEs. Stratified and purposive sampling was used. Descriptive statistics were calculated using Statistical Package for the Social Science (SPSS) version 20. Exploratory factor analysis (EFA) was done on all items of the study while research hypotheses were tested using Structural Equation Modelling (SEM) in AMOS version 21. The study concluded that vehicle maintenance, fuel management, driver management and vehicle replacement positively influence service delivery. In addition, the study also established that Information and Communication Technologies (ICTs) moderate the influence of vehicle fleet management practices on service delivery. The study recommended that there is need for regular driver training and vehicle programs encompassing electronic spares tracking.
基金supported by the National Natural Science Foundation of China(No.51909252)the Fundamental Research Funds for the Central Universities(No.202061004)This work is also partly supported by the China Scholar Council.
文摘As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method.
文摘The past decade has witnessed a huge increase in the number of proposed middleware solutions for robotic fleets operating in unstructured environments. As a result, it has become difficult to decide which middleware is the most appropriate for a specific application or application domain. In this paper we first extract a set of common and specific challenges that middlewares address, and group them according to the source domain they have originated within. These challenges are derived from a specific precision agriculture use-case based on the robotic fleet for weed control elaborated within the European project RHEA-robot fleets for highly effective agriculture and forestry management. Furthermore, the paper provides an analysis of a number of different middlewares and suggests a set of criteria for systemizing representative solutions. The aim of this analysis is to assist the process of finding an adequate middleware for a specific application domain.
