Robust joint modeling of mean and dispersion through trimming

The Maximum Likelihood Estimator (MLE) and Extended Quasi-Likelihood (EQL) estimator have commonly been used to estimate the unknown parameters within the joint modeling of mean and dispersion framework. However, these estimators can be very sensitive to outliers in the data. In order to overcome this disadvantage, the usage of the maximum Trimmed Likelihood Estimator (TLE) and the maximum Extended Trimmed Quasi-Likelihood (ETQL) estimator is recommended to estimate the unknown parameters in a robust way. The superiority of these approaches in comparison with the MLE and EQL estimator is illustrated by an example and a simulation study. As a prominent measure of robustness, the finite sample Breakdown Point (BDP) of these estimators is characterized in this setting.     

面向火灾救援的室内定位与逃生路径规划系统

在发生火灾等紧急情况时,由于高层楼宇空间小、出口少的结构特性,受困人员逃生往往很困难。针对传统的被动引导逃生方式中信息获取有限、易产生人群聚集等缺点,该文提出主动式逃生导航的概念,设计了一种改进的K-Means室内定位方法,结合人群密度检测与环境信息采集,进行路径导航,实现了一套基于传感器网络与智能手机的定位导航系统。实验表明,该系统能较好地提高定位精度,避开火灾点,增大每个人的逃生几率,该文为室内逃生导航方案提供了新的思路。     

西门子SIMOTION Delta 3D picker模型应用

本文主要介绍SIMOTION运动控制系统中Delta 3D picker功能的实际应用,阐述了Delta 3D机构的控制参数设定、原点设置、三种路径插补功能在运动轨迹控制中的应用。     

关于第二积分中值定理渐近性的一个注记

对于第二积分中值定理中的搴，本文给出并证明了比文献[3]更一般的结论，文献[3]的有关定理可以看成本文定理的直接推论．     

正数和与积的对偶不等式

给出了在个数相同的两组正数之积相等的情形下,判定这两组正数之和大小的一个充分条件,由此得出了正数和最大值存在的链式条件．应用这一链式条件解决了将,nl个正数分成等个数的n个数组后,每组之积的和与每组之和的积的最值问题．对于正数积的最小值问题,证明了与正数和最大值类似的结果,且相应的定理之间互为对偶定理．     

介孔分子筛孔尺寸表征方法比较

MCM-41是由表面活性剂十六烷基三甲基溴化铵为模板剂经水热合成，550℃煅烧5h制备的规则硅质六方介摘要孔材料；Ti-MCM-41是在MCM-41的基础上，将Ti离子涂敷引入到MCM-41的介孔中合成的。该类材料孔尺寸的表征方法有N2吸附、透射电镜TEM、SAXS等，其中N2吸附、透射电镜是传统的介孔尺寸的表征方法，SAXS是近年新的介孔尺寸的表征方法。比较了Ti-MCM-41材料的孔尺寸的表征方法，得出：SAXS得到的Ti-MCM-41孔径与TEM照片的结果符合较好，但与N2吸附的结果偏差较大。SAXS、TEM、N2吸附-脱附等温线给出的Ti-MCM-41的平均孔径分别为2.00nm、2.15nm、3.60nm。     

Comparison of structural and photoluminescence properties of ZnO thin films grown by pulsed laser deposition and ultrasonic spray pyrolysis

ZnO thin films have been deposited by pulsed laser deposition (PLD) and ultrasonic spray pyrolysis (USP) method, respectively. X-ray diffraction and transmission electron microscopy characterizations indicate that ZnO film grown by PLD exhibits better crystallinity than that grown by USP. Photoluminescence spectra show that the near-band edge ultraviolet emission of film grown by PLD is narrower and shifts to higher energy, compared with that of film grown by USP. In the visible range, ZnO film grown by PLD exhibits four local level emission centered at 470 nm, 486 nm, 544 nm, and 613 nm, respectively, while the film grown by USP only presents a weak broad band emission centered at 502 nm. Hall measurement shows higher carrier density and lower hall mobility in ZnO film grown by PLD than that in film grown by USP. The higher density of intrinsic defects as well as higher crystallintiy is considered to account for the difference of photoluminescence in ZnO film grown by PLD with that in film grown by USP.     

Nanoluminograph — A New Generation of Measuring Instruments

A nanoluminescent device, or nanoluminograph, has been developed, created, and patented. By means of the device, unique information about the physicochemical properties of surface and near-surface layers of solids and ultrathin coatings of thickness less than 0.4 μm may be obtained. There is also the hope of decreasing the thickness of the subject layer with further development of the detecting component of the device. __________ Translated from Izmeritel'naya Tekhnika, No. 8, pp. 28–31, August, 2005.     

Two Modified Semicircle Control Charts for Detecting Process Improvement

A semicircle control chart can be used in detecting both increases and decreases in the mean and/or variance. In this paper, we propose two modified semicircle charts for detecting a reduction in the process variance, a.k.a. process improvement. Each of these modified semicircle charts, namely, SC1 and SC2 has two limits, defined by the inner and outer semicircles. A process improvement is detected by the SC1 scheme if a point is plotted inside the smallest semicircle, or if two successive points are plotted between the inner and outer semicircles and by the SC2 scheme if a point plots inside the smallest semicircle or if two of three successive points plot between the inner and outer semicircles. It will be shown that the two modified semicircle charts have superior average run length (ARL) performances to the basic semicircle chart in the detection of process improvement. The ARL study is conducted by means of a simulation.