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741.
介绍了一种基于定点DSP的特定人的孤立词语音识别系统,着重讨论了算法中参数快速提取的实现.该算法采用基于动态规划(DP)技术的动态时间弯折算法(DTW),采用VAD两极端点检测方案以提高端点检测的精度,以Mel尺度倒谱系数为语音识别参数.首先讨论了标准浮点实现方法,然后结合算法特点和定点DSP的结构,采用了一种优化的快速定点实现方法.测试结果表明,定点算法时间比浮点算法大大降低,使系统的性能得到了提高. 相似文献
742.
为了能够在网络环境中从大量底层入侵警报信息中正确有效地识别其背后隐藏的攻击意图和规划,提出了基于层叠条件随机场模型的网络入侵识别方法.该方法首先在低层条件随机场中解决对简单的入侵识别,并将结果传递到高层的条件随机场模型以进行对复杂的入侵识别,实现了自适应、智能化的入侵检测系统.实验结果表明,该方法有较低的误报率,综合看来比传统方法优越. 相似文献
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2009年一季度我国汽车市场能否走出“谷底”,以及何时走出“谷底”是目前车市焦点,文章用“车市波动分析法”分析中国2009年一季度汽车市场。对一季度车市取得的进展和成绩进行回顾,然后用1个系数(扩张系数)2种效应(扩张效应,收缩效应)为工具,对存在问题进行深层次剖析。对如何正视和解决走出“谷底”问题提出了明确观点:指出一季度我国车市仍在“谷底”运行,到2009年下半年有望冲出“谷底”平稳回升。 相似文献
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The lack of personalized solutions for managing the demand of joint leisure trips in cities in real time hinders the optimization of transportation system operations. Joint leisure activities can account for up to 60% of trips in cities and unlike fixed trips (i.e., trips to work where the arrival time and the trip destination are predefined), leisure activities offer more optimization flexibility since the activity destination and the arrival times of individuals can vary.To address this problem, a perceived utility model derived from non-traditional data such as smartphones/social media for representing users’ willingness to travel a certain distance for participating in leisure activities at different times of day is presented. Then, a stochastic annealing search method for addressing the exponential complexity optimization problem is introduced. The stochastic annealing method suggests the preferred location of a joint leisure activity and the arrival times of individuals based on the users’ preferences derived from the perceived utility model. Test-case implementations of the approach used 14-month social media data from London and showcased an increase of up to 3 times at individuals’ satisfaction while the computational complexity is reduced to almost linear time serving the real-time implementation requirements. 相似文献
748.
National railways are typically large and complex systems. Their network infrastructure usually includes extended track sections, bridges, stations and other supporting assets. In recent years, railways have also become a data-rich environment.Railway infrastructure assets have a very long life, but inherently degrade. Interventions are necessary but they can cause lateness, damage and hazards. Every day, thousands of discrete maintenance jobs are scheduled according to time and urgency. Service disruption has a direct economic impact. Planning for maintenance can be complex, expensive and uncertain.Autonomous scheduling of maintenance jobs is essential. The design strategy of a novel integrated system for automatic job scheduling is presented; from concept formulation to the examination of the data to information transitional level interface, and at the decision making level. The underlying architecture configures high-level fusion of technical and business drivers; scheduling optimized intervention plans that factor-in cost impact and added value.A proof of concept demonstrator was developed to validate the system principle and to test algorithm functionality. It employs a dashboard for visualization of the system response and to present key information. Real track incident and inspection datasets were analyzed to raise degradation alarms that initiate the automatic scheduling of maintenance tasks. Optimum scheduling was realized through data analytics and job sequencing heuristic and genetic algorithms, taking into account specific cost & value inputs from comprehensive task cost modelling. Formal face validation was conducted with railway infrastructure specialists and stakeholders. The demonstrator structure was found fit for purpose with logical component relationships, offering further scope for research and commercial exploitation. 相似文献
749.
随机载荷作用下铁路起重机伸缩臂模糊可靠性分析 总被引:1,自引:0,他引:1
箱形伸缩式吊臂的可靠性分析是铁路起重机设计中的重要部分。在载荷随机情况下,利用摄动随机有限元,结合板壳元,推导单元应力的均值和方差的计算公式,计算铁路救援起重机基本臂最大应力单元主应力的均值和方差,并与强度试验结果进行比较;在强度为随机变量的情况下,把结构从安全状态到失效状态的过渡性考虑成一模糊事件,采用线性隶属函数,计算了QTJS160铁路起重机伸缩式吊臂的模糊可靠度。计算结果表明,结构可靠性与载荷离差及相关系数有很大的关系;把载荷处理为随机载荷,把失效事件处理为模糊事件,符合实际情况。 相似文献
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汽车离合器扭振减振器设计方法探讨 总被引:3,自引:3,他引:0
装置于离合器从动盘中的非线性弹性-阻尼式扭振减振器可有效地控制由发动机激起的汽车传动系扭振和噪声。本文阐述目前实际应用的这一类减振器——多级式非线性扭振减振器的基本功能和构造原理,探讨在设计中选择其工作特性型式和性能参数的基本原则,提出了减振器结构设计方法的若干要点。 相似文献