With the great development of Multi-Target Tracking(MTT)technologies,many MTT algorithms have been proposed with their own advantages and disadvantages.Due to the fact that requirements to MTT algorithms vary from the...With the great development of Multi-Target Tracking(MTT)technologies,many MTT algorithms have been proposed with their own advantages and disadvantages.Due to the fact that requirements to MTT algorithms vary from the application scenarios,performance evaluation is significant to select an appropriate MTT algorithm for the specific application scenario.In this paper,we propose a performance evaluation method on the sets of trajectories with temporal dimension specifics to compare the estimated trajectories with the true trajectories.The proposed method evaluates the estimate results of an MTT algorithm in terms of tracking accuracy,continuity and clarity.Furthermore,its computation is based on a multi-dimensional assignment problem,which is formulated as a computable form using linear programming.To enhance the influence of recent estimated states of the trajectories in the evaluation,an attention function is used to reweight the trajectory errors at different time steps.Finally,simulation results show that the proposed performance evaluation method is able to evaluate many aspects of the MTT algorithms.These evaluations are worthy for selecting suitable MTT algorithms in different application scenarios.展开更多
Passenger flow is the foundation for urban rail transit(URT)operations.However,its cal-culated results from assignment models may deviate from the actual situation in both spa-tial and temporal dimensions,which arouse...Passenger flow is the foundation for urban rail transit(URT)operations.However,its cal-culated results from assignment models may deviate from the actual situation in both spa-tial and temporal dimensions,which arouses more attention and needs to be evaluated in particular.On the other hand,onboard video data from URT trains provides a potential way for model evaluation.This study defines the evaluation problem,and proposes a method-ological solution for evaluating rail transit assignment models in the temporal dimension,which includes qualitative validation and difference quantification.A suitable time granu-larity is determined for the best effectiveness,and onboard video data are used for actual passenger flow extraction.The gap between the actual and calculated data by the model is identified with nonparametric statistical techniques(NPSTs)and quantified with time ser-ies similarity measurement(TSSM)methods.A case study on the Shanghai metro demon-strates the performance of the proposed approach,and several practice implications for URT operation agencies are discussed.展开更多
Some results and developments on the extension of the inverse scattering transform to solve non-linear evolution equations in one time and two space dimensions are described.
Based on the data from China Statistical Yearbooks and China’s population cen-suses,this paper provides a systematic introduction to changes in the size of China’s population over the 70 years since the founding of ...Based on the data from China Statistical Yearbooks and China’s population cen-suses,this paper provides a systematic introduction to changes in the size of China’s population over the 70 years since the founding of the People’s Republic of China(PRC)in 1949.It analyzes population size and crude birth rate,crude death rate,natural increase rate and total fertility rate,all of which have an impact on popula-tion size in both the temporal and spatial dimensions.The paper divides China into sluggish Average Annual Growth Rate(AAGR)regions,recovering AAGR regions,and thriving AAGR regions.Challenges that may result from China’s demographic changes and strategies to address those challenges are discussed.展开更多
基金supported by the National Natural Science Foundation of China(No.62276204,No.62306222)the Natural Science Basic Research Program of Shaanxi,China(No.2023-JC-QN-0710)。
文摘With the great development of Multi-Target Tracking(MTT)technologies,many MTT algorithms have been proposed with their own advantages and disadvantages.Due to the fact that requirements to MTT algorithms vary from the application scenarios,performance evaluation is significant to select an appropriate MTT algorithm for the specific application scenario.In this paper,we propose a performance evaluation method on the sets of trajectories with temporal dimension specifics to compare the estimated trajectories with the true trajectories.The proposed method evaluates the estimate results of an MTT algorithm in terms of tracking accuracy,continuity and clarity.Furthermore,its computation is based on a multi-dimensional assignment problem,which is formulated as a computable form using linear programming.To enhance the influence of recent estimated states of the trajectories in the evaluation,an attention function is used to reweight the trajectory errors at different time steps.Finally,simulation results show that the proposed performance evaluation method is able to evaluate many aspects of the MTT algorithms.These evaluations are worthy for selecting suitable MTT algorithms in different application scenarios.
基金supported by the National Natural Science Foundation of China(Nos.72071147 and 71701152)the Fundamental Research Funds for the Central Universities of China(No.22120220628).
文摘Passenger flow is the foundation for urban rail transit(URT)operations.However,its cal-culated results from assignment models may deviate from the actual situation in both spa-tial and temporal dimensions,which arouses more attention and needs to be evaluated in particular.On the other hand,onboard video data from URT trains provides a potential way for model evaluation.This study defines the evaluation problem,and proposes a method-ological solution for evaluating rail transit assignment models in the temporal dimension,which includes qualitative validation and difference quantification.A suitable time granu-larity is determined for the best effectiveness,and onboard video data are used for actual passenger flow extraction.The gap between the actual and calculated data by the model is identified with nonparametric statistical techniques(NPSTs)and quantified with time ser-ies similarity measurement(TSSM)methods.A case study on the Shanghai metro demon-strates the performance of the proposed approach,and several practice implications for URT operation agencies are discussed.
文摘Some results and developments on the extension of the inverse scattering transform to solve non-linear evolution equations in one time and two space dimensions are described.
文摘Based on the data from China Statistical Yearbooks and China’s population cen-suses,this paper provides a systematic introduction to changes in the size of China’s population over the 70 years since the founding of the People’s Republic of China(PRC)in 1949.It analyzes population size and crude birth rate,crude death rate,natural increase rate and total fertility rate,all of which have an impact on popula-tion size in both the temporal and spatial dimensions.The paper divides China into sluggish Average Annual Growth Rate(AAGR)regions,recovering AAGR regions,and thriving AAGR regions.Challenges that may result from China’s demographic changes and strategies to address those challenges are discussed.
