Due to the presence of turbid media, such as microdust and water vapor in the environment, outdoor pictures taken under hazy weather circumstances are typically degraded. To enhance the quality of such images, this wo...Due to the presence of turbid media, such as microdust and water vapor in the environment, outdoor pictures taken under hazy weather circumstances are typically degraded. To enhance the quality of such images, this work proposes a new hybrid λ2-λ0 penalty model for image dehazing. This model performs a weighted fusion of two distinct transmission maps, generated by imposing λ2 and λ0 norm penalties on the approximate regression coefficients of the transmission map. This approach effectively balances the sparsity and smoothness associated with the λ0 and λ2 norms, thereby optimizing the transmittance map. Specifically, when the λ2 norm is penalized in the model, an updated guided image is obtained after implementing λ0 penalty. The resulting optimization problem is effectively solved using the least square method and the alternating direction algorithm. The dehazing framework combines the advantages of λ2 and λ0 norms, enhancing sparse and smoothness, resulting in higher quality images with clearer details and preserved edges.展开更多
行人检测是计算机视觉技术中一个热门的研究热点,在汽车辅助驾驶和视频监控等方面具有重要作用.由于传统的可变形部件模型(deformable part model,DPM)采用滑动窗口检测方式,在背景区域花费大量检测时间会导致检测速度降低,因此提出了...行人检测是计算机视觉技术中一个热门的研究热点,在汽车辅助驾驶和视频监控等方面具有重要作用.由于传统的可变形部件模型(deformable part model,DPM)采用滑动窗口检测方式,在背景区域花费大量检测时间会导致检测速度降低,因此提出了一种基于BING-casDPM的快速行人检测算法.首先基于二进制化梯度范数特征(binarized normed gradient,BING)训练一个二级支持向量机(support vector machine,SVM)分类器,通过该分类器快速标定出所测图像中包含各类物体的候选区域;然后根据候选区域窗口的特点进一步提取待检测框;最后将待检测框作为输入,使用级联DPM(cascade DPM,casDPM)模型进行精确检测,并将结果返回至原图.实验结果表明,该算法在基本不降低检测率的情况下,其检测速度比经典DPM模型检测速度提高了约16倍,比casDPM模型提高了约40%.展开更多
The internal temperature of cast-in-place concrete bridges undergoes strong variations during the construction as a result of environmental factors.In order to determine precisely such variations,the present study rel...The internal temperature of cast-in-place concrete bridges undergoes strong variations during the construction as a result of environmental factors.In order to determine precisely such variations,the present study relies on the finite element method,used to model the bridge box girder section and simulate the internal temperature distribution during construction.The numerical results display good agreement with measured temperature values.It is shown that when the external temperature is higher,and the internal and external temperature difference is relatively small,the deviation of the fitting line from existing specifications(Chinese specification,American specification,New Zealand specification)is relatively large and vice versa.展开更多
Recently,the authors proposed a low-cost approach,named Optimization Approach for Linear Systems(OPALS)for solving any kind of a consistent linear system regarding the structure,characteristics,and dimension of the co...Recently,the authors proposed a low-cost approach,named Optimization Approach for Linear Systems(OPALS)for solving any kind of a consistent linear system regarding the structure,characteristics,and dimension of the coefficient matrix A.The results obtained by this approach for matrices with no structure and with indefinite symmetric part were encouraging when compare with other recent and well-known techniques.In this work,we proposed to extend the OPALS approach for solving the Linear Least-Squares Problem(LLSP)and the Minimum Norm Linear System Problem(MNLSP)using any iterative low-cost gradient-type method,avoiding the construction of the matrices AT A or AAT,and taking full advantage of the structure and form of the gradient of the proposed nonlinear objective function in the gradient direction.The combination of those conditions together with the choice of the initial iterate allow us to produce a novel and efficient low-cost numerical scheme for solving both problems.Moreover,the scheme presented in this work can also be used and extended for the weighted minimum norm linear systems and minimum norm linear least-squares problems.We include encouraging numerical results to illustrate the practical behavior of the proposed schemes.展开更多
文摘Due to the presence of turbid media, such as microdust and water vapor in the environment, outdoor pictures taken under hazy weather circumstances are typically degraded. To enhance the quality of such images, this work proposes a new hybrid λ2-λ0 penalty model for image dehazing. This model performs a weighted fusion of two distinct transmission maps, generated by imposing λ2 and λ0 norm penalties on the approximate regression coefficients of the transmission map. This approach effectively balances the sparsity and smoothness associated with the λ0 and λ2 norms, thereby optimizing the transmittance map. Specifically, when the λ2 norm is penalized in the model, an updated guided image is obtained after implementing λ0 penalty. The resulting optimization problem is effectively solved using the least square method and the alternating direction algorithm. The dehazing framework combines the advantages of λ2 and λ0 norms, enhancing sparse and smoothness, resulting in higher quality images with clearer details and preserved edges.
基金supported by National Natural Science Foundation of China(Grant No.51778314).
文摘The internal temperature of cast-in-place concrete bridges undergoes strong variations during the construction as a result of environmental factors.In order to determine precisely such variations,the present study relies on the finite element method,used to model the bridge box girder section and simulate the internal temperature distribution during construction.The numerical results display good agreement with measured temperature values.It is shown that when the external temperature is higher,and the internal and external temperature difference is relatively small,the deviation of the fitting line from existing specifications(Chinese specification,American specification,New Zealand specification)is relatively large and vice versa.
文摘Recently,the authors proposed a low-cost approach,named Optimization Approach for Linear Systems(OPALS)for solving any kind of a consistent linear system regarding the structure,characteristics,and dimension of the coefficient matrix A.The results obtained by this approach for matrices with no structure and with indefinite symmetric part were encouraging when compare with other recent and well-known techniques.In this work,we proposed to extend the OPALS approach for solving the Linear Least-Squares Problem(LLSP)and the Minimum Norm Linear System Problem(MNLSP)using any iterative low-cost gradient-type method,avoiding the construction of the matrices AT A or AAT,and taking full advantage of the structure and form of the gradient of the proposed nonlinear objective function in the gradient direction.The combination of those conditions together with the choice of the initial iterate allow us to produce a novel and efficient low-cost numerical scheme for solving both problems.Moreover,the scheme presented in this work can also be used and extended for the weighted minimum norm linear systems and minimum norm linear least-squares problems.We include encouraging numerical results to illustrate the practical behavior of the proposed schemes.
