词拼音输入法的容错研究

本文从四川方言出发,讨论了方音拼读错误的特征及规律,结合皿amm访g距离理论及多层次 文件结构,提出了一种具有方音容错能力的词拼音输入方案。      

SACSR:a low power BIST method for sequential circuits

A novel built-in-self-test (BIST) method called seeded autonomous cyclic shift register (SACSR) is presented to reduce test power of the sequential circuit. The key idea is to use a pseudorandom pattern generator and several XOR gates to generate seeds that share fewer test vectors. The generated seed is taken XOR operation with a cyclic shift register, and the single input change (SIC) sequence is generated. The proposed scheme is easily implemented and can reduce the switching activities of the circuit under test (CUT) greatly. Experimental results on ISCAS89 benchmarks show that on average more than 63% power reduction can be achieved. It also demonstrates that the generated test vectors attain high fault coverage for stuck-at fault and transition fault coverage with short test length.     

Human reliability analysis method on armored vehicle system considering error correction

Human reliability analysis(HRA) is an expansion of man-machine engineering. It is also a new multidisciplinary based on behavioral science, cognitive science, information processing, system analysis and probability statistics in order to analyze, predict, reduce and prevent human errors. Firstly, the quantitative analysis model of HRA is proposed based on Markov process theory by using human error probability(HEP) and error correction cycle(ECC) as parameters. And human reliability evaluation criterion is built. Then, the HRA process considering error correction is proposed based on cognitive reliability and error analysis method(CREAM). Finally, according to the characteristics of armored vehicle system, common performance condition(CPC) in CREAM is improved.A reliability impact index is characterized by the overall contexts of tasks. Human reliability evaluation criterion of armored vehicle system is formulated. And the result of HRA is obtained based on the method presented in this paper. In addition, the relative weights are estimated by combining scale of 10/10—18/2 and analytical hierarchy process(AHP), and the triangular fuzzy number considering confidence factor and optimism index is adopted in order to reduce the subjectivity. The analysis results show that the method presented in this paper is reasonable and feasible. Meantime, the method can provide guidance for human reliability analysis of other weapon systems.     

汽车安全行驶间距预警系统研究

高速公路汽车安全行驶间距预警系统具有技术先进、性能可靠、性价比高等特点,具有一定的实用价值。     

基于无线传感网的铁路隧道环境无线监测系统设计

依据隧道环境监测需求及特点,提出了一种环境参数无线监测系统设计方案,实现了ZigBee短距离无线通信技术与GPRS远程通信技术的有效结合,完成了传感器网络中数据采集节点以及网络协调节点的硬件和软件开发,并设计了适合于数据实时传输的通信协议.测试表明,该系统测量误差小,可靠性高,适合应用于铁路隧道环境监测.     

信号控制交叉口机动车绿灯间隔-安全可靠度曲线簇

为了提高信号控制交叉口(以下简称为“交叉口”)的安全性,提出一种基于安全可靠度的交叉口机动车绿灯间隔计算方法,并绘制面向工程应用的绿灯间隔-安全可靠度曲线簇. 首先,对经典的交叉口绿灯间隔计算方法进行了归纳;其次,推导出基于安全可靠度的绿灯间隔计算方法公式并对各影响因素进行敏感性分析;再次,基于Monte Carlo算法模拟反应时间与车辆减速度的交互过程,对模型进行求解;最后,根据模拟结果,绘制了典型交叉口宽度 (15~35 m)、车辆运行速度(15~40 km/h)及安全可靠度(50%~95%)取值下的交叉口绿灯间隔-安全可靠度曲线簇.结果表明：经典的交叉口绿灯间隔计算方法的核心缺陷在于未考虑车道组内车辆行为参数的随机性;交叉口绿灯间隔受多个因素影响且服从正态分布,绿灯间隔对反应时间(32.46%)及车辆减速度(24.68%)的敏感性最强.将安全可靠度引入绿灯间隔计算过程中,一方面提供了一种基于概率论的计算思路与方法,另一方面为定量地分析交叉口绿灯间隔的安全性提供了依据.     

非完全信息条件下交通分布预测时间(距离)法

对于新兴城镇和快速扩张城市的交通分布预测,由于信息缺乏很难采用传统的预测方法.本文提出了非完全信息下的交通分布预测时间(距离)法,并给出了其参数标定方法,对其可靠性也进行了实证性分析,最后,探讨了该模型对时间(或距离)的敏感性问题.     

基于累积前景理论的通勤者路径选择模型

为了全面描述决策者在不确定环境下的出行行为,从价值变化和可靠性变化两个方面研究通勤者的路径选择行为及对待风险的态度,提出了基于累积前景理论（CPT）的通勤者路径选择模型.首先推广了两个参考点的CPT,接着根据不确定理论对行程时间进行预算,给出通勤者参考点估计的统一方法,然后构造通勤者的路径选择模型. 最后在一个测试网络上研究可靠度与参考点及可靠度与累积前景值的关系.结果表明,通勤者的参考点可以根据可靠度要求动态设置.出发时刻相同,出行者可靠度要求较高时,风险较低的路径前景值较大;反之可靠度要求较低时,行程时间平均值较小,虽然风险较高的路径前景值也比较大,这一结论与事实相符合.本文所提出的决策模型能够有效地描述通勤者在随机路网中的路径选择行为.     

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为了全面描述决策者在不确定环境下的出行行为,从价值变化和可靠性变化两个方面研究通勤者的路径选择行为及对待风险的态度,提出了基于累积前景理论（CPT）的通勤者路径选择模型。首先推广了两个参考点的CPT,接着根据不确定理论对行程时间进行预算,给出通勤者参考点估计的统一方法,然后构造通勤者的路径选择模型。最后在一个测试网络上研究可靠度与参考点及可靠度与累积前景值的关系。结果表明,通勤者的参考点可以根据可靠度要求动态设置。出发时刻相同,出行者可靠度要求较高时,风险较低的路径前景值较大;反之可靠度要求较低时,行程时间平均值较小,虽然风险较高的路径前景值也比较大,这一结论与事实相符合。本文所提出的决策模型能够有效地描述通勤者在随机路网中的路径选择行为。     

基于多层模型的城市建成环境对通勤行为的影响

为研究城市建成环境对居民通勤行为的影响,考虑个体社会经济属性和交通小区建成环境属性的跨层次结构,建立多层模型,分别分析了个体社会经济属性层面和交通小区建成环境层面对通勤时间及通勤距离的影响,并利用长春市居民出行调查数据标定模型参数. 结果表明：多层模型比传统的回归模型拟合效果更好;控制个体社会经济属性特征后,土地利用混合度、交叉口密度及公共交通站点密度对居民通勤出行时间和距离的影响均呈现显著的负效应,而居民居住地到城市中心商务区(CBD)的距离仅对通勤距离有显著的正向影响.研究结果可为通过城市规划优化通勤结构提供理论支持.     

格库铁路HDPE板栅栏有效防护距离

以格库铁路现场风沙试验段为研究对象, 运用数值模拟方法研究了HDPE板栅栏周围的风沙流场, 给出了不同初始风速下HDPE板栅栏有效防护距离与其孔隙率和高度的关系, 研究结果表明: 气流经过HDPE板栅栏时, 气流速度在栅栏前降低较快, 在栅栏后恢复较快, 经过一段距离后逐渐恢复到初始风速, 气流速度整体呈V形分布, 气流速度增减幅度随HDPE板栅栏孔隙率的增大逐渐减小; 在同一孔隙率下, 初始风速分别为6、24 m·s-1时, HDPE板栅栏背风侧回流区相差4.5倍HDPE板栅栏的高度; 孔隙率为60%时, 最小气流速度为8.9 m·s-1, HDPE板栅栏背风侧回流消失; 随着HDPE板孔隙率的增大, 最小气流速度逐渐增大; HDPE板栅栏的孔隙率存在不产生栅栏背风侧回流区的界限孔隙率, 为40%~60%;孔隙率小于50%时, 随着HDPE板孔隙率的增大, 有效防护距离逐渐增大, 孔隙率大于50%时, 随着HDPE板孔隙率的增大, 有效防护距离逐渐减小, 当孔隙率趋于100%时, 其有效防护距离趋于0, 因此, HDPE板栅栏的最优孔隙率为50%;随着高度的增加, HDPE板栅栏背风侧恢复到初始风速的距离增加, 同一风速下, 孔隙率为50%的HDPE板栅栏的有效防护距离是孔隙率为25%的HDPE板栅栏的1.35倍; 在现场布设HDPE板栅栏时建议使用40%~50%孔隙率的栅栏, 在经济条件允许的情况下可考虑适当增加栅栏高度, 以保证路基免受风沙侵蚀。      

Degradation Reliability Analysis Based on TOPSIS Model Selection Method

It is necessary to determine the degradation path model of products at first when using the method based on degradation path model to evaluate the degradation reliability of products.At present,the degradation path model is mainly determined by scatter plots of degradation data.However,this method has strong subjectivity and is liable to cause the evaluation results to be inconsistent with the actual situation.In this paper,a degradation reliability analysis method based on TOPSIS(technique for order preference by similarity to an ideal solution)model selection is proposed,and its implementation process is given.The optimal degradation path model is selected according to the calculated proximity.With the help of TOPSIS method,various degradation path models can be selected and quantified,and the original degradation path method can be improved to avoid the risk of errors in product reliability evaluation caused by inaccurate subjective hypothesis,so as to ensure the objectivity and accuracy in the process of model determination.The validity and practicability of the proposed method are verified by the degradation analysis of the injector of a certain type of diesel engine.     

混凝土在路桥桩基施工中的作用及技术研究

机械钻孔灌注桩最大的优点就是具备强大的适应能力,并且其机械设备也比较简单,施工工艺非常成熟,施工安全可靠性高。因此,机械钻孔灌注桩在路桥施工中的应用也极为普遍。     

Experimental study on frictional and sealing performances of packing rings in an oil-free gas compressor

To enhance the reliability and to extend service life of packing rings, tribological and sealing performances are investigated based on the experimental results. Friction force, leakage rate and power consumption of three materials of pressure packing seals are measured in a refitted vertical gas compressor. The rings are made of common filled polytetrafluroethylene (Filled PTFE), PTFE reinforced with 30% mass fraction carbon fiber (30%CF+PTFE), and carbon-carbon composites infiltrated with PTFE (C/C+PTFE), respectively. It is found that packing rings will periodically vibrate with the periodic vibration of pressure packing after the travel direction of motion abruptly turns to the reverse direction. Furthermore, the amplitude of vibration slows down with the increasing crank angle. Approximate value of friction force is available by multiple-point fast Fourier transformation (FFT) employed to process the experimental results by reducing the impact of vibration to a great extent. Of three materials of rings employed in experiments, Filled PTFE presents minimal leakage rate accompanied with maximum power consumption. And 30%CF+PTFE exhibits minimum friction power and moderate leakage rate. As for C/C+PTFE, its high mechanical and thermal properties are favorable factors to enhance the ability of operating under high pressure and velocity and to improve the wear resistance. Unfortunately, this also leads to a large leakage rate. Comprehensive consideration should be taken into to evaluate the availability, reliability and service life for a type of packing ring under dry running conditions.     

动车组单部件两级非完美维护策略及优化研究

对动车组部件的维修保养是保证车辆在运营期间具有一定可靠度的重要措施,其维护周期的确定直接影响铁路运输安全.基于我国动车组的多级维护制度,提出部件的多等级非完美维护策略.选取动车组四级修时更换的部件为研究对象,建立了一种基于里程故障威布尔分布的两级非完美维护模型.以我国现行的动车组维护计划为框架,提出了动车组部件的两种维护方案,将维修时间和维修成本作为优化目标,应用多目标遗传算法对研究区间内的维修周期和所需的维修等级进行决策,并与单一非完美维护模型的优化结果进行比较.研究结果表明,两级非完美维护策略能以更低的维护成本得到满足可靠度要求的维护计划,且在不严格匹配整车维修等级的部件维护方案下得到的维护计划能够在较少的维护成本和维护次数下使部件处于较高的可靠度,更具经济性和安全性.      

基于手机传感器的车辆轨迹实时在线压缩方法

随着具有定位功能的各类便携式移动设备的普及,产生了大量的移动目标时空轨迹数据,庞大的数据规模对轨迹数据管理和分析带来了严峻的挑战.?车辆时空轨迹数据压缩算法,通过监测分析车辆在不同运动行为模式下智能手机内置线性加速度传感器和方向传感器的数据变化规律,识别车辆的转向行为和变速行为,并根据识别结果请求GPS传感器定位,记录...     

Conjoint Analysis Based Transit Service Quality Research

Transit quality service is an important factor that affects the bus split rate. This paper studies the passenger's preference of the bus service with the conjoint analysis. Through the actual survey and data analysis, the utility values of the reliability, frequency, walking time, etc. are measured. And the attributes' weights are determined through the utility values. The results show that the bus reliability is passengers' first concern, which is followed by in-bus environment, walking time and frequency. And the station environment and the price weight low. Then the bus service quality in Nanjing was investigated based on the attributes. The results show that passengers' evaluations about reliability, in-bus environment and frequency in the peak period are much lower than that in the non-peak period. And their evaluation on reliability is very low. The peak period in-bus environment and frequency also get bad evaluation.     

基于道路服务水平可靠性的交通影响程度研究

交通影响程度评价是交通影响分析的决策依据,是交通影响分析的重要问题之一。把道路服务水平引入交通影响程度分析中,并对基于道路服务水平可靠性的交通影响程度分析方法进行研究,具有较强的实用价值。     

基于PLC与组态软件的电梯控制系统设计

该文基于PLC控制器的特点,以1台4层电梯教学模型为设计对象,设计了适用于PLC控制的电梯工作要求、I/O分配、控制程序框图.结合组态王软件制作人机对话界面,监控电梯控制系统的运行情况.实践证明,该系统具有人机交互界面友好、运行安全可靠、抗干扰能力强,自动化程度高等特点,具有一定的先进性和实用性.     

基于椭球模型的FANS航线算法

为提高RNAV（区域导航）精度,采用空间向量分析,导出了FANS（国际民航组织倡导的新航行系统）航线的初始航线角和航线距离计算公式;用辛普森自适应算法进行了仿真计算,并与大圆航线的计算结果进行了比较.结果表明,当航程小于1 000 km时,对于近EW走向的航线,FANS航线比大圆航线长约0.35%;而对于近SN走向的航线,FANS航线比大圆航线短约0.24%.