监测Lévy稳定过程均值变点的平均运行时间估计

平均运行长度(时间)(ARL)是判断一控制图监测变点效果好坏的一个重要工具.本文主要研究Lévy稳定过程的均值变点监测问题.我们给出了三个控制图,即EWMA,GEWMA和GLR的ARL估计,并通过数值模拟比较了4个控制图监测均值变点的效果和差异.     

Infrared detection of a planet next to a bright star

Humans have always dreamt about the possibility of existence of planets in solar systems other than our own. After flying by, dropping probes, and even landing devices on most planets within our own solar system, the search for extra-solar planet is included in every proposal to either build a larger and better earth-, space-, or moon-based telescope, or observatory facility. The preliminary analysis seems to indicate that wavelength band from 25 μm to 30 μm is most promising in solving this problem. A number of IR technological challenges are to be overcome before the actual detection system can even be considered in a detailed design. The significant technical challenges of finding a planet will be described. Then details are given on the feasibility of detecting a planet with an instrument concept designed specifically for this purpose, a space-based, rotating rotationally shearing interferometer.     

A coincidence transmission electron microscope with digital waveform measuring system for analytical microscopy

We have been developing a new analytical transmission electron microscope (TEM), called a coincidence TEM, which in principle enables elemental mapping images to be observed at a high signal‐to‐noise (S/N) ratio under very low dose radiation conditions. In this paper, we report the development of a coincidence TEM with a digital waveform measuring system for obtaining a coincidence elemental mapping image. In this system, analog signals detected by a Si(Li) detector and a multianode, position‐sensitive photomultiplier (PSPM) are continuously converted into 12‐bit digital waveform data at a rate of 100 MHz, and transferred to a PC. From the transferred digital waveform data, information on X‐ray photon energy, electron incident position, and detection times of both X rays and electrons are calculated by digital waveform measurement, which lead to the observation of a successful coincidence elemental mapping image. Copyright © 2005 John Wiley & Sons, Ltd.     

Weak and Strong Solutions for the Stokes Approximation of Non-homogeneous Incompressible Navier-Stokes Equations

In this paper,the Dirichlet problem of Stokes approximate of non-homogeneous incompressibleNavier-Stokes equations is studied.It is shown that there exist global weak solutions as well as global andunique strong solution for this problem,under the assumption that initial density ρ_0(x)is bounded away from0 and other appropriate assumptions(see Theorem 1 and Theorem 2).The semi-Galerkin method is applied toconstruct the approximate solutions and a prior estimates are made to elaborate upon the compactness of theapproximate solutions.     

透射式跑道能见度激光测量仪的研究

介绍了一种利用激光测量跑道水平及斜视能见度的智能化仪器。该仪器主要由光学系统、信号放大与处理系统及显示系统三部分组成。简要介绍了该仪器的基本结构、工作原理和主要技术指标，讨论了其中的技术难点及其相应的解决办法。     

反光板(合作目标)反射率测量仪

本文介绍了反光板（合作目标）反射率测量仪的研制。仪器采用对称双光路比较测量法，给定两束相等光通量的光束，分别作为参考光束和测试光束，并用分束器实现原光路取样，从而解决了合作目标反光板入射光线与反射光线重合不能用常规测试方法来检测的难题。由于采用对称双光路的方法，入射光通量是相对恒定的，不受外界因素影响，从而使反射率测量仪达到精度高、重复性好和环境要求低的设计要求。     

The practice for eight-year operation of the cobalt-60 irradiation facility at Beijing Radiation Application Research Center

The radiation facility was made by Sulzer Company in Switzerland. The designed capacity is 3.7 × 10¹⁶Bq( 1MCi) and 12.21 × 10¹⁵Bq(330kCi)of Cobalt -60 source was loaded at the first phase. Current cobalt -60 source-loading is 2.4 × 10¹⁶Bq(650kCi). The equipment assembling and installation regulating and testing were completed at the end of 1988. The facility was put into commissioning in 1989. It operates 7000–8000 hours per year. The facility has been utilized to carry out many research work and irradiate many kinds of items. Lots of economical benefits have been gained since then. Now it is becoming a radiation processing model base in China. This paper summarized the strong and weak points of the design of the facility through in eight years' practice and analysed the economical benefits.     

Novel All Digital Scheme for Open Loop Fiber Optic Gyroscopes

ＮｏｖｅｌＡｌＤｉｇｉｔａｌＳｃｈｅｍｅｆｏｒＯｐｅｎＬｏｏｐＦｉｂｅｒＯｐｔｉｃＧｙｒｏｓｃｏｐｅｓＹＡＮＧＹｕａｎｈｏｎｇ（Ｔｈｅ５ｔｈＲｅｓｅａｒｃｈＤｉｖｉｓｉｏｎｏｆＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕｔｓ＆Ａｓｔｒｏｎａｕ...     

Optimality for set functions with values in ordered vector spaces

Let (X, , ) be a finite atomless measure space,L a convex subfamily of , andY andZ locally convex Hausdorff topological vector spaces which are ordered by the conesC andD, respectively. LetF:LY beC-convex andG:LZ beD-convex set functions. Consider the following optimization problem (P): minimizeF(), subject to L andG() _D . The paper generalizes the Moreau-Rockafellar theorem with set functions. By applying this theorem, a Kuhn-Tucker type optimality condition and a Fritz John type optimality condition for problem (P) are established. The duality theorem for problem (P) is also studied.This work was partially supported by National Science Council, Taipei, Taiwan. This paper was written while the first author was visiting at the University of Iowa, 1987-88.The authors would like to express their gratitude to the two anonymous referees for their valuable comments. Also, they would like to thank Professor P. L. Yu for his encouragement and suggestions which improved the material presented here considerably.