平行双跑道机场净空障碍物评定

对军用机场净空规格进行了分析,建立了单跑道和平行双跑道机场净空区障碍物限制面的数学模型.在此数学模型的基础上,使用ArcGIS系列软件建立平行双跑道机场净空限制面三角网高程模型,并进行三维显示,将数字高程模型与平行双跑道机场地形图相叠加,对军用平行双跑道机场净空障碍物进行了评定.分析结果表明:障碍物O1、O2、O3三点...     

交流电力功率智能传感器粗信号处理

为提高交流电力功率性能指标的测试精度和实时性,基于相关性分析和最小二乘误差理论,研究了交流电力智能传感器的粗信号处理方法.采用最小二乘特征参数法,对交流电压和电流值的初始采样点进行估算,获得了电力功率参数.在此基础上,将最小二乘特征参数法与相关分析法进行了比较,给出了基于相关分析法和最小二乘特征参数法进行功率测试的运算量公式,并分析了运算的复杂度.实验结果表明,当干扰幅值从信号幅值的3%放宽至12%时,基于最小二乘特征参数法的粗信号处理方法与现有方法相比,其计算工作量可减少49.4%,测试误差减少了2/3,同时降低了系统的信/噪比要求.     

具有粒子群特征的并行蚁群算法在输电网络规划中的应用

输电网络规划是一个复杂的多变量非线性整数规划问题,针对蚁群算法计算时间长、易陷入局部最优解等问题,本文提出一种新的具有粒子群特征的并行蚁群算法,并应用于输电网络规划.实验结果证明了该算法在输电网络规划优化中应用的可行性和有效性.     

基于Linux下MiniGUI的图像处理GUI平台设计

目前嵌入式技术产品被广泛应用于社会的各个领域,因此,为它们设计直观、实用、易于操作的人机交互界面越发迫切.提出了一种基于MiniGUI/Embedded图像处理系统的设计方案,重点讨论了该方案所采用的图形支持系统MiniGUI、人机交互界面的设计和实现过程、事件消息驱动机制在该系统设计过程中的应用,以及图像处理系统和人...     

公路工程试验检测数据处理问题探析

在公路工程的施工技术管理中,工程试验检测是一个重要环节,同时也是公路施工质量控制和工程竣工验收工作中不可或缺的一个关键步骤。针对这样一个关键环节,从数据表达和误差表示两个方面分析公路工程试验检测数据处理问题,可供参考借鉴。     

二次蒸发制备的CuxS薄膜特性研究

在玻璃基底上通过两次蒸发的新技术制备SuxS薄膜，硫在衬底温度为160℃-200℃时与淀积在衬底上的铜直接发生反应，生成CuxS薄膜，实验发现，生成的CuxS薄与衬底温度有很大关系。160℃时生成的CuxS呈黄绿色，而在190℃左右生成的多晶状的CuxS薄膜，颜色为深绿色，通过XRD、SEM、TS等方法样品的组织结构进行了研究和讨论。     

Multivariable speed synchronisation for a parallel hybrid electric vehicle drivetrain

In this article, a new drivetrain configuration of a parallel hybrid electric vehicle is considered and a novel model-based control design strategy is given. In particular, the control design covers the speed synchronisation task during a restart of the internal combustion engine. The proposed multivariable synchronisation strategy is based on feedforward and decoupled feedback controllers. The performance and the robustness properties of the closed-loop system are illustrated by nonlinear simulation results.     

提高标准件模具寿命的有效途径

在汽车标准件的生产过程中,模具起着主导作用,只有提高模具寿命,才能起到事半功倍的效果。有效提高标准件模具的寿命,除了需要合理选用模具的材料,合理设计模具的结构,做好模具的热处理以及加工与抛光外,还要选用恰当的润滑剂和精度高的设备,同时要加强管理,提高操作者的素质。     

From Twitter to detector: Real-time traffic incident detection using social media data

The effectiveness of traditional incident detection is often limited by sparse sensor coverage, and reporting incidents to emergency response systems is labor-intensive. We propose to mine tweet texts to extract incident information on both highways and arterials as an efficient and cost-effective alternative to existing data sources. This paper presents a methodology to crawl, process and filter tweets that are accessible by the public for free. Tweets are acquired from Twitter using the REST API in real time. The process of adaptive data acquisition establishes a dictionary of important keywords and their combinations that can imply traffic incidents (TI). A tweet is then mapped into a high dimensional binary vector in a feature space formed by the dictionary, and classified into either TI related or not. All the TI tweets are then geocoded to determine their locations, and further classified into one of the five incident categories.We apply the methodology in two regions, the Pittsburgh and Philadelphia Metropolitan Areas. Overall, mining tweets holds great potentials to complement existing traffic incident data in a very cheap way. A small sample of tweets acquired from the Twitter API cover most of the incidents reported in the existing data set, and additional incidents can be identified through analyzing tweets text. Twitter also provides ample additional information with a reasonable coverage on arterials. A tweet that is related to TI and geocodable accounts for approximately 5% of all the acquired tweets. Of those geocodable TI tweets, 60–70% are posted by influential users (IU), namely public Twitter accounts mostly owned by public agencies and media, while the rest is contributed by individual users. There is more incident information provided by Twitter on weekends than on weekdays. Within the same day, both individuals and IUs tend to report incidents more frequently during the day time than at night, especially during traffic peak hours. Individual tweets are more likely to report incidents near the center of a city, and the volume of information significantly decays outwards from the center.