The urban transit fare structure and level can largely affect passengers’travel behavior and route choices.The commonly used transit fare policies in the present transit network would lead to the unbalanced transit a...The urban transit fare structure and level can largely affect passengers’travel behavior and route choices.The commonly used transit fare policies in the present transit network would lead to the unbalanced transit assignment and improper transit resources distribution.In order to distribute transit passenger flow evenly and efficiently,this paper introduces a new distance-based fare pattern with Euclidean distance.A bi-level programming model is developed for determining the optimal distance-based fare pattern,with the path-based stochastic transit assignment(STA)problem with elastic demand being proposed at the lower level.The upper-level intends to address a principal-agent game between transport authorities and transit enterprises pursing maximization of social welfare and financial interest,respectively.A genetic algorithm(GA)is implemented to solve the bi-level model,which is verified by a numerical example to illustrate that the proposed nonlinear distance-based fare pattern presents a better financial performance and distribution effect than other fare structures.展开更多
Public authorities frequently mandate public or private agencies to manage their renewable natural resources.Contrary to the agency,which is an expert in renewable natural resource management,public authorities usuall...Public authorities frequently mandate public or private agencies to manage their renewable natural resources.Contrary to the agency,which is an expert in renewable natural resource management,public authorities usually ignore the sustainable level of harvest.In this note,we first model the contractual relationship between a principal,who owns the renewable natural resource,and an agent,who holds private information on its sustainable level of harvest.We then look for the Pareto-optimal allocations.In the situation of an imperfect information setting,we find that the Pareto-optimal contracting depends on the probability that the harvesting level stands outside the sustainability interval.The information rent held by the agent turns out to be unavoidable,such that stepping outside the sustainability interval implies the possibility of depletion of the renewable natural resource.This,in turn,compromises the maintenance of the ecological balance in natural ecosystems.展开更多
目标表观建模是基于稀疏表示的跟踪方法的研究重点,针对这一问题,提出一种基于判别性局部联合稀疏表示的目标表观模型,并在粒子滤波框架下提出一种基于该模型的多任务跟踪方法 (Discriminative local joint sparse appearance model bas...目标表观建模是基于稀疏表示的跟踪方法的研究重点,针对这一问题,提出一种基于判别性局部联合稀疏表示的目标表观模型,并在粒子滤波框架下提出一种基于该模型的多任务跟踪方法 (Discriminative local joint sparse appearance model based multitask tracking method,DLJSM).该模型为目标区域内的局部图像分别构建具有判别性的字典,从而将判别信息引入到局部稀疏模型中,并对所有局部图像进行联合稀疏编码以增强结构性.在跟踪过程中,首先对目标表观建立上述模型;其次根据目标表观变化的连续性对采样粒子进行初始筛选以提高算法的效率;然后求解剩余候选目标状态的联合稀疏编码,并定义相似性函数衡量候选状态与目标模型之间的相似性;最后根据最大后验概率估计目标当前的状态.此外,为了避免模型频繁更新而引入累积误差,本文采用每5帧判断一次的方法,并在更新时保留首帧信息以减少模型漂移.实验测试结果表明DLJSM方法在目标表观发生巨大变化的情况下仍然能够稳定准确地跟踪目标,与当前最流行的13种跟踪方法的对比结果验证了DLJSM方法的高效性.展开更多
基金the Humanities and Social Science Foundation of the Ministry of Education of China(Grant No.20YJCZH121).
文摘The urban transit fare structure and level can largely affect passengers’travel behavior and route choices.The commonly used transit fare policies in the present transit network would lead to the unbalanced transit assignment and improper transit resources distribution.In order to distribute transit passenger flow evenly and efficiently,this paper introduces a new distance-based fare pattern with Euclidean distance.A bi-level programming model is developed for determining the optimal distance-based fare pattern,with the path-based stochastic transit assignment(STA)problem with elastic demand being proposed at the lower level.The upper-level intends to address a principal-agent game between transport authorities and transit enterprises pursing maximization of social welfare and financial interest,respectively.A genetic algorithm(GA)is implemented to solve the bi-level model,which is verified by a numerical example to illustrate that the proposed nonlinear distance-based fare pattern presents a better financial performance and distribution effect than other fare structures.
基金financially supported by a grant overseen by the French National Forestry Office through the Forests for Tomorrow International Teaching and Research Chair(Convention particulière n°1/2013)supported by the French National Research Agency through the Laboratory of Excellence ARBRE,a part of the Investments for the Future Program(ANR 11--LABX-0002-01).
文摘Public authorities frequently mandate public or private agencies to manage their renewable natural resources.Contrary to the agency,which is an expert in renewable natural resource management,public authorities usually ignore the sustainable level of harvest.In this note,we first model the contractual relationship between a principal,who owns the renewable natural resource,and an agent,who holds private information on its sustainable level of harvest.We then look for the Pareto-optimal allocations.In the situation of an imperfect information setting,we find that the Pareto-optimal contracting depends on the probability that the harvesting level stands outside the sustainability interval.The information rent held by the agent turns out to be unavoidable,such that stepping outside the sustainability interval implies the possibility of depletion of the renewable natural resource.This,in turn,compromises the maintenance of the ecological balance in natural ecosystems.
文摘目标表观建模是基于稀疏表示的跟踪方法的研究重点,针对这一问题,提出一种基于判别性局部联合稀疏表示的目标表观模型,并在粒子滤波框架下提出一种基于该模型的多任务跟踪方法 (Discriminative local joint sparse appearance model based multitask tracking method,DLJSM).该模型为目标区域内的局部图像分别构建具有判别性的字典,从而将判别信息引入到局部稀疏模型中,并对所有局部图像进行联合稀疏编码以增强结构性.在跟踪过程中,首先对目标表观建立上述模型;其次根据目标表观变化的连续性对采样粒子进行初始筛选以提高算法的效率;然后求解剩余候选目标状态的联合稀疏编码,并定义相似性函数衡量候选状态与目标模型之间的相似性;最后根据最大后验概率估计目标当前的状态.此外,为了避免模型频繁更新而引入累积误差,本文采用每5帧判断一次的方法,并在更新时保留首帧信息以减少模型漂移.实验测试结果表明DLJSM方法在目标表观发生巨大变化的情况下仍然能够稳定准确地跟踪目标,与当前最流行的13种跟踪方法的对比结果验证了DLJSM方法的高效性.
