使用互补码提高OTDR测量动态范围的方法

使用互补码光脉冲作为光时域反射计的探测脉冲可以大幅提高光时域反射计的性能,在不影响距离分辨率的前提下提高有效测量距离、减少测量所需时间。基于此,介绍了该方法的理论基础并给出了具体的应用方法及仿真结果。     

线性度对线性调频雷达距离分辨力的影响

讨论了线性度对线性调频雷达距离分辨力的影响,求得了线性调频雷达的极限分辨力,导出了调频非线性对距离分辨力影响的数学表达式,以及用于工程的近似估计公式。用计算机仿真验证了这种影响。仿真结果和理论分析表明,距离分辨力随以下三个参数的增大而降低:国标距离,频率偏离函数F(t)的高次谐波和最大值。线性调频雷达的极限分辨力取决于发射波形的带宽。     

Bayesian robustness in bidimensional models: Prior independence

When θ is a multidimensional parameter, the issue of prior dependence or independence of coordinates is a serious concern. This is especially true in robust Bayesian analysis; Lavine et al. (J. Amer. Statist. Assoc.86, 964–971 (1991)) show that allowing a wide range of prior dependencies among coordinates can result in near vacuous conclusions. It is sometimes possible, however, to make confidently the judgement that the coordinates of θ are independent a priori and, when this can be done, robust Bayesian conclusions improve dramatically. In this paper, it is shown how to incorporate the independence assumption into robust Bayesian analysis involving -contamination and density band classes of priors. Attention is restricted to the case θ = (θ₁, θ₂) for clarity, although the ideas generalize.     

关于加权广义逆的三个矩阵乘积的不变性

利用矩阵D-AXC的最大最小秩,给出了矩阵AXC的乘积、秩以及值域的不变性,其中X为矩阵B的各种加权广义逆.     

Habitat use and activity patterns of urban-dwelling javelina

In Arizona, conflicts between homeowners and urban-dwelling javelina (Tayassu tajacu) continued to increase. Human-javelina conflicts often occurred when javelina responded to urban attractants and destroyed ornamental landscapes, injured pets, and frightened homeowners. This prompted initiation of a study during 1992–93 to develop recommendations to alleviate these conflicts. We captured, radio-collared, and located eight javelina from six herds to determine home ranges, habitat use, and activity patterns in Prescott, Arizona. Urban-dwelling javelina adjusted their home ranges, habitat use, and activity patterns to best use human-provided urban food, water, and cover resources. The most conspicuous of these adjustments was the increased nocturnal activity of urban-dwelling javelina to avoid human disturbances. Undeveloped land within or adjacent to Prescott provided javelina with daytime bedding areas and nighttime travel corridors. We determined that this issue was more a people problem than it was a javelina problem. Thus, strategies to resolve the conflicts must target homeowners.     

Application of Multivariate Analysis to Increase the Yield of Dry Cell Batteries

In an organization, the manufacturing process of a dry cell battery was suffering from the problem of frequent stoppages in the assembly line. The complete battery manufacturing operation is highly automated and mechanized. It was suspected that excessive variation in overall height of bobbin was the major reason for such stoppages. The bobbin, the inside part of a dry cell battery acting as cathode, is formed by the battery extrusion process. A planned experiment was carried out on the extrusion process that identified the setting of extrusion machines and the amount of water content in the cathode mixture as the parameters causing variation in the bobbin characteristics. The problem of frequent stoppages was eliminated when appropriate action was taken on these two parameters. Finally, multivariate and univariate control schemes were developed for online control of the bobbin characteristics.     

居延汉简中的统括性范围副词

居延汉简为屯戍记录,簿籍类文书占有很大的比重;与材料的性质相适应,居延汉简出现了很多统括性范围副词。这类副词共有20个,有的是承袭先秦汉语而来的,有的是汉代新产生的;其中"往往、大凡、最凡、与此、并"等统括性范围副词的用法较有特点。     

行政公诉的法理与制度建构——一个法律监督的视角

我国行政公诉不同于西方国家行政公诉的特点,我国行政公诉既是一种公力救济,又具有典型的监督属性,它始终以公权力监督为贯穿主线,体现为对行政权的直接监督、有限监督.从公共利益优先权和公力救济有限性的角度界定行政公诉的范围,将督促行政主体履行职责作为提起行政公诉的前置程序,以节省诉讼成本,提高监督效率.基于检察机关拥有特别的公权力,检察监督具有明显的司法性、专门性、专业性,以及为了防止行政公诉的恣意,诉讼中应当以检察机关负举证责任为原则,行政机关仅对其控制的行政信息情报、规范性文件以及公害案件涉及的高度专业性、技术性问题负责举证.     

Distribution of the coates-diggle test statistic in case of replicated observations

A closed form expression for the distribution of a test statistic for comparing the spectral densities of stationary processes is given. This test statistic was introduced by COATES and DIGGLE ( 1986 ) for the unreplicated case and has been extended to the case of replicated observations by POTSCHER and RESCHENHOFER ( 1988 ). A simple method for computing approximate critical values in case of large numbers of replications is also provided. As a by-product an explicit expression for the distribution function of the range of independent variates each distributed as the logarithm of an F-variate i.e up to a factor of 2 each followin Fishers z-distriution is obtained     

Exponential family distribution with unknown truncation parameter: two sample problem

The uniformly most powerful unbiased tests are formulated for two sample problem of a given continuous distribution belonging to the exponential family with unknown scale and truncation parameters. The two-parameter exponential and Paretc distributions are considered in examples.