The quantization algorithm compresses the original network by reducing the numerical bit width of the model,which improves the computation speed. Because different layers have different redundancy and sensitivity to d...The quantization algorithm compresses the original network by reducing the numerical bit width of the model,which improves the computation speed. Because different layers have different redundancy and sensitivity to databit width. Reducing the data bit width will result in a loss of accuracy. Therefore, it is difficult to determinethe optimal bit width for different parts of the network with guaranteed accuracy. Mixed precision quantizationcan effectively reduce the amount of computation while keeping the model accuracy basically unchanged. In thispaper, a hardware-aware mixed precision quantization strategy optimal assignment algorithm adapted to low bitwidth is proposed, and reinforcement learning is used to automatically predict the mixed precision that meets theconstraints of hardware resources. In the state-space design, the standard deviation of weights is used to measurethe distribution difference of data, the execution speed feedback of simulated neural network accelerator inferenceis used as the environment to limit the action space of the agent, and the accuracy of the quantization model afterretraining is used as the reward function to guide the agent to carry out deep reinforcement learning training. Theexperimental results show that the proposed method obtains a suitable model layer-by-layer quantization strategyunder the condition that the computational resources are satisfied, and themodel accuracy is effectively improved.The proposed method has strong intelligence and certain universality and has strong application potential in thefield of mixed precision quantization and embedded neural network model deployment.展开更多
Abstract:Comments on students’assignments are important for English course.The loopholes in teachers’working schemes-comments of their students’written assignments are the clues around which the paper spreads.In th...Abstract:Comments on students’assignments are important for English course.The loopholes in teachers’working schemes-comments of their students’written assignments are the clues around which the paper spreads.In the process of teaching,some English teachers pay so much attention to the contents taught in class but ignore the comments on students’written assignments.Consequently,it is not applicable for students to correct their mistakes in time and they probably make the same mistakes repeatedly.展开更多
Logistics networks (LNs) are essential for the transportation and distribution of goods or services from suppliers to consumers. However, LNs with complex structures are more vulnerable to disruptions due to natural d...Logistics networks (LNs) are essential for the transportation and distribution of goods or services from suppliers to consumers. However, LNs with complex structures are more vulnerable to disruptions due to natural disasters and accidents. To address the LN post-disruption response strategy optimization problem, this study proposes a novel two-stage stochastic programming model with robust delivery time constraints. The proposed model jointly optimizes the new-line-opening and rerouting decisions in the face of uncertain transport demands and transportation times. To enhance the robustness of the response strategy obtained, the conditional value at risk (CVaR) criterion is utilized to reduce the operational risk, and robust constraints based on the scenario-based uncertainty sets are proposed to guarantee the delivery time requirement. An equivalent tractable mixed-integer linear programming reformulation is further derived by linearizing the CVaR objective function and dualizing the infinite number of robust constraints into finite ones. A case study based on the practical operations of the JD LN is conducted to validate the practical significance of the proposed model. A comparison with the rerouting strategy and two benchmark models demonstrates the superiority of the proposed model in terms of operational cost, delivery time, and loading rate.展开更多
The electromagnetic mass damper (EMD) control system, as an innovative active control system to reduce structural vibration, offers many advantages over traditional active mass driver/damper (AMD) control systems. In ...The electromagnetic mass damper (EMD) control system, as an innovative active control system to reduce structural vibration, offers many advantages over traditional active mass driver/damper (AMD) control systems. In this paper, studies of several EMD control strategies and bench-scale shaking table tests of a two-story model structure are described. First, two structural models corresponding to uncontrolled and Zeroed cases are developed, and parameters of these models are validated through sinusoidal sweep tests to provide a basis for establishing an accurate mathematical model for further studies. Then, a simplified control strategy for the EMD system based on the pole assignment control algorithm is proposed. Moreover, ideal pole locations are derived and validated through a series of shaking table tests. Finally, three benchmark earthquake ground motions and sinusoidal sweep waves are imposed onto the structure to investigate the effectiveness and feasibility of using this type of innovative active control system for structural vibration control. In addition, the robustness of the EMD system is examined. The test results show that the EMD system is an effective and robust system for the control of structural vibrations.展开更多
In this paper,we investigate a kind of truck-door assignment problem in a crossdock.Multiple related realistic constraints such as the capacity of trucks,the capacity of temporary storage area,the time windows of truc...In this paper,we investigate a kind of truck-door assignment problem in a crossdock.Multiple related realistic constraints such as the capacity of trucks,the capacity of temporary storage area,the time windows of trucks as well as the operational time inside the crossdock are considered and therefore,make the assignment problem strongly NP-hard and very challenging.A two-stage genetic algorithm is proposed to solve this problem and the experimental results show the superiority of this approach in comparison to CPLEX solver in terms of effectiveness and efficiency especially for the large-scale instances.That is,the decision making process can speed up and a near optimal truck-door assignment scheme can be obtained within a relatively short time by applying this two-stage approach in practice.展开更多
无人机场景下航拍图像存在密度高、目标小、覆盖范围广等特性,使得现有的目标检测器容易出现错检漏检的现象,为了提高识别的精度,提出了一种改进Yolov5的目标检测模型。通过采用梯度流丰富的C2F模块增加模型的特征提取能力。引入上采样...无人机场景下航拍图像存在密度高、目标小、覆盖范围广等特性,使得现有的目标检测器容易出现错检漏检的现象,为了提高识别的精度,提出了一种改进Yolov5的目标检测模型。通过采用梯度流丰富的C2F模块增加模型的特征提取能力。引入上采样算子CARAFE(content-aware reassembly of features)增加感受野进行数据特征融合,提升特征金字塔网络性能。通过采用全局性动态标签分配策略,提高模型识别准确率。通过VisDrone2019数据集验证表明,改进后的模型平均精度mAP值达到65.3%,较传统模型提升了24.7个百分点,可以更加准确地完成航拍过程中针对目标的检测任务。展开更多
The operational stability and economy of multi-energy systems(MES)are threatened by various uncertainties,such as variable renewable energy power,energy demands,and weather conditions.Most of the existing methods for ...The operational stability and economy of multi-energy systems(MES)are threatened by various uncertainties,such as variable renewable energy power,energy demands,and weather conditions.Most of the existing methods for the dispatch decisions of MES are based on the prescribed probability distribution or uncertainty sets of random variables,which have many disadvantages,such as potential infeasibility and over-conservatism.In this paper,we propose a novel dispatch model for MES that integrates dispatch decision making,uncertainty set selection,and operational cost control into a unified framework.First,the deterministic dispatch model of MES is introduced,in which the physical characteristics of district heating systems and buildings are fully considered.Then,a novel decision framework that combines the two-stage dispatch strategy and info-gap decision theory(IGDT)is proposed for MES,where the uncertainty set is flexible and can be optimized based on the operational cost budget.Finally,a revised algorithm,based on the column-and-constraint generation method,is proposed for the model.Case studies are performed on MES that includes a 33-bus distribution system and a heating network modified from a real 51-node network located in Jinlin Province,China.The results verify the effectiveness of the proposed method.展开更多
文摘The quantization algorithm compresses the original network by reducing the numerical bit width of the model,which improves the computation speed. Because different layers have different redundancy and sensitivity to databit width. Reducing the data bit width will result in a loss of accuracy. Therefore, it is difficult to determinethe optimal bit width for different parts of the network with guaranteed accuracy. Mixed precision quantizationcan effectively reduce the amount of computation while keeping the model accuracy basically unchanged. In thispaper, a hardware-aware mixed precision quantization strategy optimal assignment algorithm adapted to low bitwidth is proposed, and reinforcement learning is used to automatically predict the mixed precision that meets theconstraints of hardware resources. In the state-space design, the standard deviation of weights is used to measurethe distribution difference of data, the execution speed feedback of simulated neural network accelerator inferenceis used as the environment to limit the action space of the agent, and the accuracy of the quantization model afterretraining is used as the reward function to guide the agent to carry out deep reinforcement learning training. Theexperimental results show that the proposed method obtains a suitable model layer-by-layer quantization strategyunder the condition that the computational resources are satisfied, and themodel accuracy is effectively improved.The proposed method has strong intelligence and certain universality and has strong application potential in thefield of mixed precision quantization and embedded neural network model deployment.
文摘Abstract:Comments on students’assignments are important for English course.The loopholes in teachers’working schemes-comments of their students’written assignments are the clues around which the paper spreads.In the process of teaching,some English teachers pay so much attention to the contents taught in class but ignore the comments on students’written assignments.Consequently,it is not applicable for students to correct their mistakes in time and they probably make the same mistakes repeatedly.
基金supported by the National Natural Science Foundation of China(Grant Nos.72271029,72061127001,and 72201121)the National Key Research and Development Program of China(Grant No.2018AAA0101602)DongguanI nInovative ResearchTeam Program(Grant No.2018607202007).
文摘Logistics networks (LNs) are essential for the transportation and distribution of goods or services from suppliers to consumers. However, LNs with complex structures are more vulnerable to disruptions due to natural disasters and accidents. To address the LN post-disruption response strategy optimization problem, this study proposes a novel two-stage stochastic programming model with robust delivery time constraints. The proposed model jointly optimizes the new-line-opening and rerouting decisions in the face of uncertain transport demands and transportation times. To enhance the robustness of the response strategy obtained, the conditional value at risk (CVaR) criterion is utilized to reduce the operational risk, and robust constraints based on the scenario-based uncertainty sets are proposed to guarantee the delivery time requirement. An equivalent tractable mixed-integer linear programming reformulation is further derived by linearizing the CVaR objective function and dualizing the infinite number of robust constraints into finite ones. A case study based on the practical operations of the JD LN is conducted to validate the practical significance of the proposed model. A comparison with the rerouting strategy and two benchmark models demonstrates the superiority of the proposed model in terms of operational cost, delivery time, and loading rate.
基金The National Natural Science Foundation of China Under Grant. No.50608026The National Major Foundamental Program (973 Program) of China Under Grant No. 2007CB714204
文摘The electromagnetic mass damper (EMD) control system, as an innovative active control system to reduce structural vibration, offers many advantages over traditional active mass driver/damper (AMD) control systems. In this paper, studies of several EMD control strategies and bench-scale shaking table tests of a two-story model structure are described. First, two structural models corresponding to uncontrolled and Zeroed cases are developed, and parameters of these models are validated through sinusoidal sweep tests to provide a basis for establishing an accurate mathematical model for further studies. Then, a simplified control strategy for the EMD system based on the pole assignment control algorithm is proposed. Moreover, ideal pole locations are derived and validated through a series of shaking table tests. Finally, three benchmark earthquake ground motions and sinusoidal sweep waves are imposed onto the structure to investigate the effectiveness and feasibility of using this type of innovative active control system for structural vibration control. In addition, the robustness of the EMD system is examined. The test results show that the EMD system is an effective and robust system for the control of structural vibrations.
文摘In this paper,we investigate a kind of truck-door assignment problem in a crossdock.Multiple related realistic constraints such as the capacity of trucks,the capacity of temporary storage area,the time windows of trucks as well as the operational time inside the crossdock are considered and therefore,make the assignment problem strongly NP-hard and very challenging.A two-stage genetic algorithm is proposed to solve this problem and the experimental results show the superiority of this approach in comparison to CPLEX solver in terms of effectiveness and efficiency especially for the large-scale instances.That is,the decision making process can speed up and a near optimal truck-door assignment scheme can be obtained within a relatively short time by applying this two-stage approach in practice.
文摘无人机场景下航拍图像存在密度高、目标小、覆盖范围广等特性,使得现有的目标检测器容易出现错检漏检的现象,为了提高识别的精度,提出了一种改进Yolov5的目标检测模型。通过采用梯度流丰富的C2F模块增加模型的特征提取能力。引入上采样算子CARAFE(content-aware reassembly of features)增加感受野进行数据特征融合,提升特征金字塔网络性能。通过采用全局性动态标签分配策略,提高模型识别准确率。通过VisDrone2019数据集验证表明,改进后的模型平均精度mAP值达到65.3%,较传统模型提升了24.7个百分点,可以更加准确地完成航拍过程中针对目标的检测任务。
基金the National Science Foundation of China(52207080)in part by the State Grid Jiangsu Electric Power Company Science and Technology Project(J2020001)in part by the National Science Foundation of Jiangsu Province(BK20200404).
文摘The operational stability and economy of multi-energy systems(MES)are threatened by various uncertainties,such as variable renewable energy power,energy demands,and weather conditions.Most of the existing methods for the dispatch decisions of MES are based on the prescribed probability distribution or uncertainty sets of random variables,which have many disadvantages,such as potential infeasibility and over-conservatism.In this paper,we propose a novel dispatch model for MES that integrates dispatch decision making,uncertainty set selection,and operational cost control into a unified framework.First,the deterministic dispatch model of MES is introduced,in which the physical characteristics of district heating systems and buildings are fully considered.Then,a novel decision framework that combines the two-stage dispatch strategy and info-gap decision theory(IGDT)is proposed for MES,where the uncertainty set is flexible and can be optimized based on the operational cost budget.Finally,a revised algorithm,based on the column-and-constraint generation method,is proposed for the model.Case studies are performed on MES that includes a 33-bus distribution system and a heating network modified from a real 51-node network located in Jinlin Province,China.The results verify the effectiveness of the proposed method.