位置刻度分布族中参数的两步置信区间

寻找一些分布中的参数的具有预先给定宽度和预先给定覆盖概率的置信区间是令人感兴趣的，对于位置刻度分布族中位置参数和刻度参数，这种类型的置信区间的存在性问题已在文献中被解决，本文利用两步抽样，具体地构造出这样的固定宽度置信区间，此外，对于Cauchy分布，第一阶段的最优抽样量和一些统计量的分位点也被计算出，所得到的结果具有应用价值。     

砷化镓高速集成电路内部电信号的光探针直接取样

本文介绍了电光取样技术原理报道了砷化镓高速集成电路内部电信号在片直接电光取样测量系统,它的时间分辨率优于20ps,空间分辨率优于3μm.通过对砷化镓共面波导的测量证实该系统可以对砷化镓高速集成电路内部电信号进行在片直接电光取样测量。     

《1992年中央人民广播电台全国听众抽样调查》综合报告

本报告描述了１９９２年中央人民广播电台全国听众抽样调查的设计、主要结果和特色．     

Use of solid phase microextraction in diffusive sampling of the atmosphere generated by different essential oils

This work describes the development and optimisation of a complete headspace-solid phase microextraction (HS-SPME) procedure for qualitative and quantitative analysis of the equilibrium headspace generated by a number of essential oils (EOs) with potential applications in active packaging, including basil (Ocinum basilicum), clove (Sygyzium aromaticum), rosemary (Rosmarinus officinalis), citronella (Melissa officinalis), and cinnamon (Cinnamonum zeylanicum). The method consists of a combination of fully exposed HS-SPME for qualitative analysis and diffusive HS-SPME for quantitative determination.First, complete optimisation of a fully exposed HS-SPME procedure was carried out by means of a combination of a Plackett-Burman screening experimental design and response surface modelling (RSM). The results were used to fully describe the atmosphere generated by the EOs and to select the most relevant compounds for further consideration.The fibres were then calibrated (i.e. the uptake rate was calculated) by exposing them to known concentrations of terpenes in closed extraction vials. With a sampling time of 30 min at 20 °C, uptake rates ranged from 2.2 to 3.3 pg (min ppb_v)⁻¹. Results were checked by sampling over extended periods of times, with the observed variation being less than 5%, despite a 10-fold increase in extraction time. The results were further validated by comparing the calculated diffusion coefficients with theoretical data. The ratios of experimental:theoretical values varied between 0.85 and 1.05. The sensitivity of the uptake rate to headspace concentration was also investigated; variation of less than 10% was observed despite changes in concentration of four orders of magnitude. The new diffusive sampling method proved to give robust determinations of all the test analytes (by contrast, HS-SPME failed for camphene, camphor and cinnamaldehyde), providing repetitivity and intermediate precision lower than 9% (the values for HS-SPME were 10 and 12%, respectively).     

激光扫描图象数据采集系统非线性失真的反馈补偿

为获取低几何畸变高重复性的激光扫描图象,我们提出了一种基于闭环象素时钟发生器的激光扫描器非线性误差补偿方案,使用以驱动数据采集系统AD转换的象素时钟频率正比于扫描器运行的角速度,从而用采样时间间隔的非均匀性换取了采样点空间位置的均匀性。     

ψ(2S)扫描实验中相关数据的拟合及误差处理

文中详细讨论了ψ(2S)扫描实验数据拟合过程中同一反应道不同能量点之间,以及同一能量点不同反应道之间的复杂的相关性问题.利用最大似然函数法得到拟合公式;采用多次抽样拟合的办法避免过多待定参数带来的极小化困难;分析并综合各类误差对拟合参数的影响,从而求得最终的合成误差.文中所阐述的方法是处理实验数据拟合过程中复杂相关性问题的一种有效方法.     

Determination of optimized blending fractions for particle size distributions or molecular weight distributions involving various physical properties

It has been shown in this study that the effects of particle size distribution or molecular weight distribution on selected physical properties can be related by a generalized blending approach that involves similar equations. The blending equations developed involve different z-fractions where z = 3 for volume blending of spherical particles, or z = 2 for surface blending of spherical particles, or z = 1 for the weight blending of molecular weights. This new analysis approach addresses the magnitude of the ratios of particle size averages, D_x/D_y, or ratios of molecular weight averages, M_x/M_y, as well as the location of this maximum, the level of distribution information available for the starting materials, and the type of z-fraction blending. To illustrate this approach suspension viscosity/concentration data was used to show how the D_x/D_y ratio could be introduced successfully to analyze latex volume blending where z = 3. In addition, the maximum steady-state elastic compliance, J_e, as a function of weighted blends (z = 1) of two different molecular weights of polyisobutylene was shown to fit the simple equation J_e = 1.187 (M₃/M₂) (M₄/M₁) reasonably well. © 1995 John Wiley & Sons, Inc.     

周期变号减少核确定的完全样条与最优取样点的唯一性

证明了具有给定零点的完全样条的唯一性，证明了在卷积类上最优取样点的唯一性．     

Functional inference in semiparametric models using the piggyback bootstrap

This paper introduces the “piggyback bootstrap.” Like the weighted bootstrap, this bootstrap procedure can be used to generate random draws that approximate the joint sampling distribution of the parametric and nonparametric maximum likelihood estimators in various semiparametric models, but the dimension of the maximization problem for each bootstrapped likelihood is smaller. This reduction results in significant computational savings in comparison to the weighted bootstrap. The procedure can be stated quite simply. First obtain a valid random draw for the parametric component of the model. Then take the draw for the nonparametric component to be the maximizer of the weighted bootstrap likelihood with the parametric component fixed at the parametric draw. We prove the procedure is valid for a class of semiparametric models that includes frailty regression models airsing in survival analysis and biased sampling models that have application to vaccine efficacy trials. Bootstrap confidence sets from the piggyback, and weighted bootstraps are compared for biased sampling data from simulated vaccine efficacy trials.     

Fast simulation of buffer overflows in tandem networks ofGI/GI/1 queues

Simply because of their rarity, the estimation of the statistics of buffer overflows in well-dimensioned queueing networks via direct simulation is extremely costly. One technique that can be used to reduce this cost is importance sampling, and it has been shown previously that large deviations theory can be used in conjunction with importance sampling to minimize the required simulation time. In this paper, we obtain results on the fast simulation of tandem networks of queues, and derive an analytic solution to the problem of finding an optimal simulation system for a class of tandem networks ofGI/GI/1 queues.Work supported by Australian Telecommunications and Electronics Research Board (ATERB). The authors wish to acknowledge the funding of the activities of the Cooperative Research Centre for Robust and Adaptive Systems by the Australian Commonwealth Government under the Cooperative Research Centres Program.