基于均值移动与粒子滤波融合的跟踪算法

针对均值移动算法鲁棒性差以及粒子滤波算法计算量大、难以满足实时跟踪的特点,提出2种先均值移动后粒子滤波的融合算法,分别为粒子数目保持恒定的融合算法和粒子数目自适应的融合算法。实验结果证明,与已有算法相比,2种算法在实时性提高的同时,跟踪准确性和抗干扰能力没有明显下降。     

Composite indicator for railway infrastructure management

Railway Engineering Science - The assessment and analysis of railway infrastructure capacity is an essential task in railway infrastructure management carried out to meet the required quality and...     

Estimation in X-bar control charts: effects and corrections

This paper presents an approach for improving the control limits of $ \overline{X} $ control charts when the parameters of the process are estimated and the control chart is in operation. In these conditions, the observed average run length (ARL) may be very different from the planned ARL since the parameter estimates may have a larger error. To minimize this problem, the data collected in effective control (phase 2) will be used to re-estimate the parameters with a precision greater than that obtained in phase 1. Thus, we defined a minimum sample size of observations of phase 2, which is constituted of a mixture of two normal distributions that should be used to re-estimate the process parameters. The proposal is illustrated with numerical example.     

Compact power-efficient class-AB CMOS exponential voltage to voltage converter

A novel implementation of a rail-to-rail exponential voltage to voltage converter is presented. It is based on a pseudo-exponential approximation that is easily achieved by the nonlinear currents of a class-AB transconductor. Measurement results for a 0.5 /spl mu/m CMOS technology show a 52 dB output voltage range with linearity error less than /spl plusmn/2 dB using a dual supply voltage of /spl plusmn/750 mV. The power dissipation is less than 40 /spl mu/W.     

Methodology for the reliability evaluation of a passive system and its integration into a Probabilistic Safety Assessment

A methodology has been developed to evaluate the reliability of passive systems characterised by a moving fluid and whose operation is based on thermal–hydraulic (T-H) principles. The methodology includes:

• identification and quantification of the sources of uncertainties and determination of the important variables;

• propagation of the uncertainties through T-H models and assessment of T-H passive system unreliability;

• introduction of passive system unreliability in the accident sequence analysis.

Each step of the methodology is described and commented and a diagram of the methodology is presented. An example of passive system is presented with the aim to illustrate the possibilities of the methodology. This example is the Residual Passive heat Removal system on the Primary circuit (RP2), an innovating system supposed to be implemented on a 900 MWe Pressurized Water Reactor.     

反应气相色谱法测定饮用水中的氯乙酸

采用固相提取法从饮用水中分离出氯乙酸进行酯化，并将其转化为三氟乙酸酯，通过实验确定了最佳酯化条件，并用电子俘获检测器进行气相色谱分离和测定。     

基于遗传算法的分布式异构数据库的查询优化

对于分布武异构数据库，查询优化问题是其核心问题。本文用基于位、值结构树型编码的遗传算法对分布武异构数据库进行查询优化，取得了很好的效果。     

一种单相电路无功电流实时检测新方法的研究

对单相电网电流进行了分解并提出一种新的谐波电流实时检测方法，该方法的算法简单且容易实现。在此基础上，根据具体的补偿要求，进一步研究了对单相电路基波无功电流的检测。计算机仿真结果有效地证明该方法能达到预期的效果。     

Fatigue of bituminous mixtures

This paper presents an interlaboratory test campaign organized by the RILEM 182-PEB Technical Committee. In the campaign, 11 different test methods, comprising uniaxial tension/compression, 2-, 3- and 4-point bending and indirecttension tests, were utilized in order to investigate fatigue characteristics of a dense graded asphalt concrete mixture. The testing conditions specified were sinusoidal excitation at 10Hz and 10°C using controlled strain and stress modes. In total, more than 150 fatigue tests were carried out during the investigation. The fatigue test results were analyzed using both classical as well as continuum damage mechanics approaches. The fatigue test results obtained using the classical fatigue approach are considerably influenced by test type and mode of loading (controlled stress or strain) used. Consequently, this approach has limited use in realistic fatigue characterization of bituminous materials and pavement structures. In contrast to the classical approach, models founded on continuum damage theory may serve to isolate intrinsic fatigue characteristics from the influence of so-called biased effects, which are largely caused by the accelerated laboratory testing. The continuum damage models investigated may constitute steps, towards a rational mechanistic fatigue characterization model, which are important for effective future pavement design.