This paper develops a variational model for image noise removal using total curvature(TC), which is a high-order regularizer. The TC has the advantage of preserving image feature. Unfortunately, it also has the charac...This paper develops a variational model for image noise removal using total curvature(TC), which is a high-order regularizer. The TC has the advantage of preserving image feature. Unfortunately, it also has the characteristics of nonlinear, non-convex and non-smooth. Consequently, the numerical computation with the curvature regularization is difficult. In order to conquer the computation problem, the proposed model is transformed into an alternating optimization problem by importing auxiliary variables. Furthermore, based on alternating direction method of multipliers, we design a fast numerical approximation iterative scheme for proposed model. Finally, numerous experiments are implemented to indicate the advantages of the proposed model in image edge preserving, image contrast and corners preserving. Meanwhile, the high computational efficiency of the designed model is verified by comparing with traditional models, including the total variation(TV) and total Laplace(TL) model.展开更多
By analyzing the internal features of counting sorting algorithm. Two improvements of counting sorting algorithms are proposed, which have a wide range of applications and better efficiency than the original counting ...By analyzing the internal features of counting sorting algorithm. Two improvements of counting sorting algorithms are proposed, which have a wide range of applications and better efficiency than the original counting sort while maintaining the original stability. Compared with the original counting sort, it has a wider scope of application and better time and space efficiency. In addition, the accuracy of the above conclusions can be proved by a large amount of experimental data.展开更多
【目的】在空间超冗余机械臂动力学建模中,其结构复杂、自由度多及刚性弱导致的动力学耦合问题十分突出,难以获得精准的动力学模型。针对此问题,提出了一种应用迭代WLS-TCS算法的空间超冗余机械臂地面动力学参数辨识方法,为获取机械臂...【目的】在空间超冗余机械臂动力学建模中,其结构复杂、自由度多及刚性弱导致的动力学耦合问题十分突出,难以获得精准的动力学模型。针对此问题,提出了一种应用迭代WLS-TCS算法的空间超冗余机械臂地面动力学参数辨识方法,为获取机械臂的高精度动力学模型和空间在轨动力学控制研究奠定基础。【方法】首先,采用一种基于终端交叉和转向的粒子群优化(Terminal Crossover and Steering-based Particle Swarm Optimization,TCS-PSO)算法来设计满足多约束条件的周期傅里叶级数,并将其作为最优的激励轨迹;其次,应用迭代加权最小二乘(Iterative Weighted Least Squares,IWLS)法获取最小参数集,通过迭代加权逐步剔除数据中的异常值,使得辨识结果更加鲁棒、准确。【结果】试验结果表明,在激励轨迹中,采用TCS优化方法获得的轨迹回归矩阵条件数更少,且能更好满足所给的约束条件。在参数辨识中,采用IWLS法辨识所得的结果对比递归最小二乘法,力矩残差均方根(Root Mean Square,RMS)值平均降低约2.22%;对比加权最小二乘法,力矩残差RMS值平均降低约4.85%。将获取的参数模型代入到零力控制试验中,实际效果符合预期。展开更多
驱动力控制系统(Traction Control System,TCS)是在制动防抱死系统的基础上发展起来的一套主动安全控制系统,它根据汽车的行驶状况,通过采用适当的控制算法使汽车驱动轮在恶劣路面或复杂行驶条件下也能产生最佳的纵向驱动力,从而提高汽...驱动力控制系统(Traction Control System,TCS)是在制动防抱死系统的基础上发展起来的一套主动安全控制系统,它根据汽车的行驶状况,通过采用适当的控制算法使汽车驱动轮在恶劣路面或复杂行驶条件下也能产生最佳的纵向驱动力,从而提高汽车的驱动性能和行驶稳定安全性能。通过对TCS控制原理的分析,明确滑转率的控制目标,结合TCS的控制方式,阐述TCS的常用控制算法,并对其进行比较,探讨TCS控制算法的选择依据和方法。展开更多
Regression testing(RT)is an essential but an expensive activity in software development.RT confirms that new faults/errors will not have occurred in the modified program.RT efficiency can be improved through an effect...Regression testing(RT)is an essential but an expensive activity in software development.RT confirms that new faults/errors will not have occurred in the modified program.RT efficiency can be improved through an effective technique of selected only modified test cases that appropriate to the modifications within the given time frame.Earlier,several test case selection approaches have been introduced,but either these techniques were not sufficient according to the requirements of software tester experts or they are ineffective and cannot be used for available test suite specifications and architecture.To address these limitations,we recommend an improved and efficient test case selection(TCS)algorithm for RT.Our proposed technique decreases the execution time and redundancy of the duplicate test cases(TC)and detects onlymodified changes that appropriate to themodifications in test cases.To reduce execution time for TCS,evaluation results of our proposed approach are established on fault detection,redundancy and already executed test case.Results indicate that proposed technique decreases the inclusive testing time of TCS to execute modified test cases by,on average related to a method of Hybrid Whale Algorithm(HWOA),which is a progressive TCS approach in regression testing for a single product.展开更多
Sustained heavy ethanol drinking is a common problem globally and ethanol is one of the most abused drugs among individuals of different socio-economic status including the HIV-infected patients on antiretroviral drug...Sustained heavy ethanol drinking is a common problem globally and ethanol is one of the most abused drugs among individuals of different socio-economic status including the HIV-infected patients on antiretroviral drugs. Ethanol is reward drug and a CNS depressant especially at high doses. The study determined the effect of sustained heavy ethanol drinking by HIV-infected patients on d4T/3TC/NVP regimen on CD4+ cell counts in Uganda using WHO AUDIT tool and chronic alcohol-use biomarkers. A case control study using repeated measures design with serial measurements model was used. The patients on stavudine (d4T) 30 mg, lamivudine (3TC) 150 mg and nevirapine (NVP) 200 mg and chronic alcohol use were recruited. A total of 41 patients (20 in alcohol group and 21 in control group) were screened for chronic alcohol use by WHO AUDIT tool and chronic alcohol use biomarkers. They were followed up for 9 months with blood sampling done at 3 months intervals. CD4+ cell count was determined using Facscalibur Flow Cytometer system. Results were then sorted by alcohol-use biomarkers (GGT, MCV and AST/ ALT ratio). Data were analysed using SAS 2003 version 9.1 statistical package with repeated measures fixed model and the means were compared using student t-test. The mean CD4+ cell counts in all the groups were lower than the reference ranges at baseline and gradually increased at 3, 6 and 9 months of follow-up. The mean CD4+ cell counts were higher in the control group as compared to the chronic alcohol use group in both WHO AUDIT tool group and chronic alcohol-use biomarkers group though there was no significant difference (p > 0.05). Chronic alcohol use slightly lowers CD4+ cell count in HIV-infected patients on d4T/3TC/NVP treatment regimen.展开更多
相位细分技术是提高精密仪器测量分辨率和精度的关键技术。传统的机械、光学等细分技术已难以满足当前高精度测量领域的需求。基于坐标旋转数字计算(Coordinate Rotation Digital Computer,CORDIC)方法的角度计算原理,将输入的正交信号...相位细分技术是提高精密仪器测量分辨率和精度的关键技术。传统的机械、光学等细分技术已难以满足当前高精度测量领域的需求。基于坐标旋转数字计算(Coordinate Rotation Digital Computer,CORDIC)方法的角度计算原理,将输入的正交信号转换为向量(x,y),通过多次旋转迭代使向量最终收敛于X轴,对旋转角度进行求和即可得到目标角度值。基于FPGA用Verilog语言编写CORDIC算法,可以实现相位细分、信号辨向和整周期计数功能,通过扩展数据位宽消除了算法迭代过程中产生的舍入误差。对改进算法进行了仿真与实验验证,结果表明经过20级迭代后其理论分辨率为0.4″,计算角度的误差为±0.5″,光栅测角系统实际测量误差减小了约98.42%。该算法通过对正交信号进行精密细分来计算精密仪器的相角变化量,在工程应用中具有普适性。展开更多
基金supported by the National Natural Science Foundation of China(No.61602269)the China Postdoctoral Science Foundation(No.2015M571993)+1 种基金the Shandong Provincial Natural Science Foundation of China(No.ZR2017MD004)the Qingdao Postdoctoral Application Research Funded Project
文摘This paper develops a variational model for image noise removal using total curvature(TC), which is a high-order regularizer. The TC has the advantage of preserving image feature. Unfortunately, it also has the characteristics of nonlinear, non-convex and non-smooth. Consequently, the numerical computation with the curvature regularization is difficult. In order to conquer the computation problem, the proposed model is transformed into an alternating optimization problem by importing auxiliary variables. Furthermore, based on alternating direction method of multipliers, we design a fast numerical approximation iterative scheme for proposed model. Finally, numerous experiments are implemented to indicate the advantages of the proposed model in image edge preserving, image contrast and corners preserving. Meanwhile, the high computational efficiency of the designed model is verified by comparing with traditional models, including the total variation(TV) and total Laplace(TL) model.
文摘By analyzing the internal features of counting sorting algorithm. Two improvements of counting sorting algorithms are proposed, which have a wide range of applications and better efficiency than the original counting sort while maintaining the original stability. Compared with the original counting sort, it has a wider scope of application and better time and space efficiency. In addition, the accuracy of the above conclusions can be proved by a large amount of experimental data.
文摘【目的】在空间超冗余机械臂动力学建模中,其结构复杂、自由度多及刚性弱导致的动力学耦合问题十分突出,难以获得精准的动力学模型。针对此问题,提出了一种应用迭代WLS-TCS算法的空间超冗余机械臂地面动力学参数辨识方法,为获取机械臂的高精度动力学模型和空间在轨动力学控制研究奠定基础。【方法】首先,采用一种基于终端交叉和转向的粒子群优化(Terminal Crossover and Steering-based Particle Swarm Optimization,TCS-PSO)算法来设计满足多约束条件的周期傅里叶级数,并将其作为最优的激励轨迹;其次,应用迭代加权最小二乘(Iterative Weighted Least Squares,IWLS)法获取最小参数集,通过迭代加权逐步剔除数据中的异常值,使得辨识结果更加鲁棒、准确。【结果】试验结果表明,在激励轨迹中,采用TCS优化方法获得的轨迹回归矩阵条件数更少,且能更好满足所给的约束条件。在参数辨识中,采用IWLS法辨识所得的结果对比递归最小二乘法,力矩残差均方根(Root Mean Square,RMS)值平均降低约2.22%;对比加权最小二乘法,力矩残差RMS值平均降低约4.85%。将获取的参数模型代入到零力控制试验中,实际效果符合预期。
文摘驱动力控制系统(Traction Control System,TCS)是在制动防抱死系统的基础上发展起来的一套主动安全控制系统,它根据汽车的行驶状况,通过采用适当的控制算法使汽车驱动轮在恶劣路面或复杂行驶条件下也能产生最佳的纵向驱动力,从而提高汽车的驱动性能和行驶稳定安全性能。通过对TCS控制原理的分析,明确滑转率的控制目标,结合TCS的控制方式,阐述TCS的常用控制算法,并对其进行比较,探讨TCS控制算法的选择依据和方法。
基金This work was supported in part by the Research Management Center(RMC),Universiti Teknologi Malaysia(UTM)and Ministry of Higher Education Malaysia(MOHE)through the UTM High Impact Research(UTMHR)grant scheme under(Vot Number Q.J130000.2451.08G55).
文摘Regression testing(RT)is an essential but an expensive activity in software development.RT confirms that new faults/errors will not have occurred in the modified program.RT efficiency can be improved through an effective technique of selected only modified test cases that appropriate to the modifications within the given time frame.Earlier,several test case selection approaches have been introduced,but either these techniques were not sufficient according to the requirements of software tester experts or they are ineffective and cannot be used for available test suite specifications and architecture.To address these limitations,we recommend an improved and efficient test case selection(TCS)algorithm for RT.Our proposed technique decreases the execution time and redundancy of the duplicate test cases(TC)and detects onlymodified changes that appropriate to themodifications in test cases.To reduce execution time for TCS,evaluation results of our proposed approach are established on fault detection,redundancy and already executed test case.Results indicate that proposed technique decreases the inclusive testing time of TCS to execute modified test cases by,on average related to a method of Hybrid Whale Algorithm(HWOA),which is a progressive TCS approach in regression testing for a single product.
文摘Sustained heavy ethanol drinking is a common problem globally and ethanol is one of the most abused drugs among individuals of different socio-economic status including the HIV-infected patients on antiretroviral drugs. Ethanol is reward drug and a CNS depressant especially at high doses. The study determined the effect of sustained heavy ethanol drinking by HIV-infected patients on d4T/3TC/NVP regimen on CD4+ cell counts in Uganda using WHO AUDIT tool and chronic alcohol-use biomarkers. A case control study using repeated measures design with serial measurements model was used. The patients on stavudine (d4T) 30 mg, lamivudine (3TC) 150 mg and nevirapine (NVP) 200 mg and chronic alcohol use were recruited. A total of 41 patients (20 in alcohol group and 21 in control group) were screened for chronic alcohol use by WHO AUDIT tool and chronic alcohol use biomarkers. They were followed up for 9 months with blood sampling done at 3 months intervals. CD4+ cell count was determined using Facscalibur Flow Cytometer system. Results were then sorted by alcohol-use biomarkers (GGT, MCV and AST/ ALT ratio). Data were analysed using SAS 2003 version 9.1 statistical package with repeated measures fixed model and the means were compared using student t-test. The mean CD4+ cell counts in all the groups were lower than the reference ranges at baseline and gradually increased at 3, 6 and 9 months of follow-up. The mean CD4+ cell counts were higher in the control group as compared to the chronic alcohol use group in both WHO AUDIT tool group and chronic alcohol-use biomarkers group though there was no significant difference (p > 0.05). Chronic alcohol use slightly lowers CD4+ cell count in HIV-infected patients on d4T/3TC/NVP treatment regimen.
文摘相位细分技术是提高精密仪器测量分辨率和精度的关键技术。传统的机械、光学等细分技术已难以满足当前高精度测量领域的需求。基于坐标旋转数字计算(Coordinate Rotation Digital Computer,CORDIC)方法的角度计算原理,将输入的正交信号转换为向量(x,y),通过多次旋转迭代使向量最终收敛于X轴,对旋转角度进行求和即可得到目标角度值。基于FPGA用Verilog语言编写CORDIC算法,可以实现相位细分、信号辨向和整周期计数功能,通过扩展数据位宽消除了算法迭代过程中产生的舍入误差。对改进算法进行了仿真与实验验证,结果表明经过20级迭代后其理论分辨率为0.4″,计算角度的误差为±0.5″,光栅测角系统实际测量误差减小了约98.42%。该算法通过对正交信号进行精密细分来计算精密仪器的相角变化量,在工程应用中具有普适性。
