The strong convergence and convergence rate of the random quadratic formss1T(S1S1T)ms1 and s1T(SST)ms1 are set up. The application of these results in wireless communication is given. Simulation results are presented.
In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Hal...In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Haloxylon ammodendron population. ArcGIS software was used to summarize and analyze the spatial point pattern response of Haloxylon ammodendron population. The results showed that: 1) There were significant differences in the performance of point pattern analysis among different random quadrants. The paired t-test for variance mean ratio showed that the P values were 0.048, 0.004 and 0.301 respectively, indicating that the influence of quadrat shape on the performance of point pattern analysis was significant under the condition of the same optimal quadrat area. 2) The comparative analysis of square shapes shows that circular square is the best, square and regular hexagonal square are the second, and there is no significant difference between square and regular hexagonal square. 3) The number of samples plays a decisive role in spatial point pattern analysis. Insufficient sample size will lead to unstable results. With the increase of the number of samples to more than 120, the V value and P value curves will eventually stabilize. That is, stable spatial point pattern analysis results are closely related to the increase of the number of samples in random sample square analysis.展开更多
In this paper we study the integral curve in a random vector field perturbed by white noise. It is related to a stochastic transport-diffusion equation. Under some conditions on the covariance function of the vector f...In this paper we study the integral curve in a random vector field perturbed by white noise. It is related to a stochastic transport-diffusion equation. Under some conditions on the covariance function of the vector field, the solution of this stochastic partial differential equation is proved to have moments. The exact p-th moment is represented through integrals with respect to Brownian motions. The basic tool is Girsanov formula.展开更多
This paper studies the problem of robust H∞ control of piecewise-linear chaotic systems with random data loss. The communication links between the plant and the controller are assumed to be imperfect （that is, data ...This paper studies the problem of robust H∞ control of piecewise-linear chaotic systems with random data loss. The communication links between the plant and the controller are assumed to be imperfect （that is, data loss occurs intermittently, which appears typically in a network environment）. The data loss is modelled as a random process which obeys a Bernoulli distribution. In the face of random data loss, a piecewise controller is designed to robustly stabilize the networked system in the sense of mean square and also achieve a prescribed H∞ disturbance attenuation performance based on a piecewise-quadratic Lyapunov function. The required H∞ controllers can be designed by solving a set of linear matrix inequalities （LMIs）. Chua＇s system is provided to illustrate the usefulness and applicability of the developed theoretical results.展开更多
针对传统轨迹规划算法在狭长空间规划成功率低、自适应程度差等问题,提出一种基于虚拟障碍物决策的自适应两阶段轨迹规划方法。首先,通过动态规划和二次规划完成无人车辆的路径规划和速度规划;其次,提出了一种自适应聚集采样策略解决了...针对传统轨迹规划算法在狭长空间规划成功率低、自适应程度差等问题,提出一种基于虚拟障碍物决策的自适应两阶段轨迹规划方法。首先,通过动态规划和二次规划完成无人车辆的路径规划和速度规划;其次,提出了一种自适应聚集采样策略解决了狭长空间较难通过的问题;最后,构建了一种基于随机森林的虚拟障碍物决策模型提升了无人车辆在不同会车情况决策的合理性。在Carla(car learning to act)仿真平台的结果表明,相比于传统方法,该方法在狭窄区域的静态多障碍物避障时路径长度、路径曲率分别降低了2.4%、85.6%,规划成功率、安全性及其稳定性分别提高了约20%、20.6%和44.9%;在狭窄区域的动态多障碍物避障时路径长度、路径曲率分别降低了8.3%、76.4%,规划成功率、安全性及其稳定性分别提高了约36%、78.2%和45.3%。最后,将方法部署到实际无人车辆中,在狭长的走廊场景设置障碍物进行测试,验证了方法的有效性。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grants No.10471135 and 10271001).
文摘The strong convergence and convergence rate of the random quadratic formss1T(S1S1T)ms1 and s1T(SST)ms1 are set up. The application of these results in wireless communication is given. Simulation results are presented.
文摘In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Haloxylon ammodendron population. ArcGIS software was used to summarize and analyze the spatial point pattern response of Haloxylon ammodendron population. The results showed that: 1) There were significant differences in the performance of point pattern analysis among different random quadrants. The paired t-test for variance mean ratio showed that the P values were 0.048, 0.004 and 0.301 respectively, indicating that the influence of quadrat shape on the performance of point pattern analysis was significant under the condition of the same optimal quadrat area. 2) The comparative analysis of square shapes shows that circular square is the best, square and regular hexagonal square are the second, and there is no significant difference between square and regular hexagonal square. 3) The number of samples plays a decisive role in spatial point pattern analysis. Insufficient sample size will lead to unstable results. With the increase of the number of samples to more than 120, the V value and P value curves will eventually stabilize. That is, stable spatial point pattern analysis results are closely related to the increase of the number of samples in random sample square analysis.
文摘In this paper we study the integral curve in a random vector field perturbed by white noise. It is related to a stochastic transport-diffusion equation. Under some conditions on the covariance function of the vector field, the solution of this stochastic partial differential equation is proved to have moments. The exact p-th moment is represented through integrals with respect to Brownian motions. The basic tool is Girsanov formula.
基金Project partially supported by the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.60904004)the Key Youth Science and Technology Foundation of University of Electronic Science and Technology of China (Grant No.L08010201JX0720)
文摘This paper studies the problem of robust H∞ control of piecewise-linear chaotic systems with random data loss. The communication links between the plant and the controller are assumed to be imperfect （that is, data loss occurs intermittently, which appears typically in a network environment）. The data loss is modelled as a random process which obeys a Bernoulli distribution. In the face of random data loss, a piecewise controller is designed to robustly stabilize the networked system in the sense of mean square and also achieve a prescribed H∞ disturbance attenuation performance based on a piecewise-quadratic Lyapunov function. The required H∞ controllers can be designed by solving a set of linear matrix inequalities （LMIs）. Chua＇s system is provided to illustrate the usefulness and applicability of the developed theoretical results.
文摘针对传统轨迹规划算法在狭长空间规划成功率低、自适应程度差等问题,提出一种基于虚拟障碍物决策的自适应两阶段轨迹规划方法。首先,通过动态规划和二次规划完成无人车辆的路径规划和速度规划;其次,提出了一种自适应聚集采样策略解决了狭长空间较难通过的问题;最后,构建了一种基于随机森林的虚拟障碍物决策模型提升了无人车辆在不同会车情况决策的合理性。在Carla(car learning to act)仿真平台的结果表明,相比于传统方法,该方法在狭窄区域的静态多障碍物避障时路径长度、路径曲率分别降低了2.4%、85.6%,规划成功率、安全性及其稳定性分别提高了约20%、20.6%和44.9%;在狭窄区域的动态多障碍物避障时路径长度、路径曲率分别降低了8.3%、76.4%,规划成功率、安全性及其稳定性分别提高了约36%、78.2%和45.3%。最后,将方法部署到实际无人车辆中,在狭长的走廊场景设置障碍物进行测试,验证了方法的有效性。
