降水是最难预报的天气要素之一。在预报站点和周围站点之间建立多层感知器,利用主成分分析对环流背景场和局地气象要素差异等13个因子降维,作为多层感知器的输入,并采用贪心算法选择多层感知器的结构。通过联合多个多层感知器同时预报降...降水是最难预报的天气要素之一。在预报站点和周围站点之间建立多层感知器,利用主成分分析对环流背景场和局地气象要素差异等13个因子降维,作为多层感知器的输入,并采用贪心算法选择多层感知器的结构。通过联合多个多层感知器同时预报降水,提出一种动态区域联合短时降水预报方法。实验证明该方法降水预报效果较好,3小时降水预报能力优于ECMWF(European Centre for Medium-Range Weather Forecasts)和日本气象厅(JMA)数值模式。展开更多
With Connected Vehicle Technologies being popular,drivers not only perceive downstream traffic information but also get upstream information by routinely checking backward traffic conditions,and the backward-looking f...With Connected Vehicle Technologies being popular,drivers not only perceive downstream traffic information but also get upstream information by routinely checking backward traffic conditions,and the backward-looking frequency or probability is usually affected by prevailing traffic conditions.Meanwhile,the bi-directional perception range of drivers is expected to significantly increase,which results in more informed and coordinated driving behaviours.So,we propose a traffic flow bi-directional CA model with two perception ranges,and perform the numerical simulations with the field data collected from a one-lane highway in Richmond,California,USA as the benchmark data.Numerical results show that the CA model can effectively reproduce the oscillation of relatively congested traffic and the traffic hysteresis phenomenon.When adjusting the backward-looking probability and the perception range,the CA model can well simulate the travel times of all vehicles,and the generation and dissolution of traffic jams under various scenarios.展开更多
对电力设备状态的监测,可以有效保障电力系统的安全运行。传统的状态感知方式多采用传感器结合通信线缆传递设备状态数据。由于电力设备运行环境复杂,需要监测的数据日益增多,增加了系统布点及布线的难度。基于此,研究低功耗广域网技术...对电力设备状态的监测,可以有效保障电力系统的安全运行。传统的状态感知方式多采用传感器结合通信线缆传递设备状态数据。由于电力设备运行环境复杂,需要监测的数据日益增多,增加了系统布点及布线的难度。基于此,研究低功耗广域网技术和物联网(Internet of Things,IoT)传感器技术,采用基于远距离无线电(Long Range Radio,LoRa)技术的无线组网方式,结合低功耗无线传感器,实现对电力设备状态的立体化全方位监测。结合工程案例,全面介绍监测系统的设计方案与配置。展开更多
文摘降水是最难预报的天气要素之一。在预报站点和周围站点之间建立多层感知器,利用主成分分析对环流背景场和局地气象要素差异等13个因子降维,作为多层感知器的输入,并采用贪心算法选择多层感知器的结构。通过联合多个多层感知器同时预报降水,提出一种动态区域联合短时降水预报方法。实验证明该方法降水预报效果较好,3小时降水预报能力优于ECMWF(European Centre for Medium-Range Weather Forecasts)和日本气象厅(JMA)数值模式。
基金supported by the National Natural Science Foundation of China(Grant No.71871227)the Innovation Driven Plan of Central South University(Grant No.20180016040002).
文摘With Connected Vehicle Technologies being popular,drivers not only perceive downstream traffic information but also get upstream information by routinely checking backward traffic conditions,and the backward-looking frequency or probability is usually affected by prevailing traffic conditions.Meanwhile,the bi-directional perception range of drivers is expected to significantly increase,which results in more informed and coordinated driving behaviours.So,we propose a traffic flow bi-directional CA model with two perception ranges,and perform the numerical simulations with the field data collected from a one-lane highway in Richmond,California,USA as the benchmark data.Numerical results show that the CA model can effectively reproduce the oscillation of relatively congested traffic and the traffic hysteresis phenomenon.When adjusting the backward-looking probability and the perception range,the CA model can well simulate the travel times of all vehicles,and the generation and dissolution of traffic jams under various scenarios.
文摘对电力设备状态的监测,可以有效保障电力系统的安全运行。传统的状态感知方式多采用传感器结合通信线缆传递设备状态数据。由于电力设备运行环境复杂,需要监测的数据日益增多,增加了系统布点及布线的难度。基于此,研究低功耗广域网技术和物联网(Internet of Things,IoT)传感器技术,采用基于远距离无线电(Long Range Radio,LoRa)技术的无线组网方式,结合低功耗无线传感器,实现对电力设备状态的立体化全方位监测。结合工程案例,全面介绍监测系统的设计方案与配置。
