An automatic image analysis system for the evaluation of dielectric track detectors

The automatic image analysis system for scanning solid state nuclear track detectors is designed by utilizing a microdensitometer. The control of the entire system as well as the data analysis are accomplished with the IBM PC computer equipped with a FrameGrabber. The system counts the number of tracks and measures their geometrical parameters. The usage of the system is illustrated by counting rhombic tracks in mica detectors which were used for the investigation of the fusion–fission reaction ¹²C+ ²⁰⁸Pb.     

动车组自动导通测试系统的设计

动车组自动导通测试系统主要完成动车组整车线缆的导通测试。首先介绍自动测试系统的研制背景,系统的功能性能指标,系统的总体框架和组成以及各个功能模块原理和功能,然后介绍自动测试系统与动车对接测试试验的具体过程。测试试验结果表明该系统能够实现动车组线缆的自动导通绝缘测试功能,测试速度快,测试准确度高,大大提高了动车组出厂生产过程中的整车线缆测试效率。     

A model system for perfusion quantification using FAIR

Flow-sensitive experiments (FAIR) have been performed on a tube-flow phantom in order to validate quantitative perfusion measurements on humans. A straight-forward correspondence between perfusion and bulk-flow is found. It is shown that the flow phantom model only holds when the slice profiles of the involved RF pulses are taken into account. A small flow-independent off-set may be present in the data. The off-set is explained by the model. Based on the correspondence between the phantom and the in vivo models, it is shown that the lowest flow values that could be measured in the phantom correspond to perfusion values lower than the cortical perfusion in the brain. Thus, the experimental accuracy and the computational methods for quantitative perfusion measurements in vivo can be validated by a tube-flow phantom.     

New control algorithm for automatic PMD compensation system

A new cross-tracking method is proposed to improve the convergent speed of the control algorithm in real-time polarization mode dispersion（PMD）compensation systems.The cross-tracking algorithm is compared with the previously used dithering particle swarm optimization（DPSO）and gradient particle swarm optimization（GPSO）algorithms,and it is proven to offer the best performance among the three algorithms.The transmission of a 43-Gb/s differential quadrature phase-shift keying（DQPSK）signal over a 1 200-km fiber span using a compensator based on digital signal processing（DSP）is demonstrated via the cross-tracking algorithm.     

分布式电磁频谱自动监测系统研制

为实现对多个区域的电磁环境同时进行监测,分析了分布式电磁监测系统的设计原则,确立了监测系统的硬件连接方案,利用以太网-GPIB控制器、集线器和控制计算机来对多台仪器进行集中控制的方式,设计了相应的系统软件。测试结果表明,该系统具备同时控制多台频谱分析仪的功能,能够实时测量电磁频谱、背景噪声、频段占用度等数据,具备测量数据存储、回放与分析、报表生成的功能,具有状态反馈和异常状态提示的功能,完全能满足多个区域电磁监测的要求。     

数字化合成全息图自动记录系统研究

从合成全息术的编码原理出发,采用了液晶空间光调制器、步进电机控制的可移动狭缝和一维移动平台等设备以及计算机数字多媒体技术、软件编程技术设计出一套数字化合成全息自动记录系统。该系统能够改善传统全息图手工制作效率低、操作不准确产生误差等缺陷,提高了合成具有视差、动感、颜色以及不同景深等特殊效果全息图的自动化水平。实际应用该系统合成了含有40幅照片信息的全息图。     

A fully automatic three-step liver segmentation method on LDA-based probability maps for multiple contrast MR images

Automatic 3D liver segmentation in magnetic resonance (MR) data sets has proven to be a very challenging task in the domain of medical image analysis. There exist numerous approaches for automatic 3D liver segmentation on computer tomography data sets that have influenced the segmentation of MR images. In contrast to previous approaches to liver segmentation in MR data sets, we use all available MR channel information of different weightings and formulate liver tissue and position probabilities in a probabilistic framework. We apply multiclass linear discriminant analysis as a fast and efficient dimensionality reduction technique and generate probability maps then used for segmentation. We develop a fully automatic three-step 3D segmentation approach based upon a modified region growing approach and a further threshold technique. Finally, we incorporate characteristic prior knowledge to improve the segmentation results. This novel 3D segmentation approach is modularized and can be applied for normal and fat accumulated liver tissue properties.     

An automatic evaluation system for NTA film neutron dosimeters

At CERN, neutron personal monitoring for over 4000 collaborators is performed with Kodak NTA films, which have been shown to be the most suitable neutron dosimeter in the radiation environment around high-energy accelerators. To overcome the lengthy and strenuous manual scanning process with an optical microscope, an automatic analysis system has been developed. We report on the successful automatic scanning of NTA films irradiated with ²³⁸Pu---Be source neutrons, which results in densely ionised recoil tracks, as well as on the extension of the method to higher energy neutrons causing sparse and fragmentary tracks. The application of the method in routine personal monitoring is discussed.     

The automatic liquid nitrogen filling system for GDA detectors

An indigenously developed automatic liquid nitrogen (LN2) filling system has been installed in gamma detector array (GDA) facility at Nuclear Science Centre. Electro-pneumatic valves are used for filling the liquid nitrogen into the high purity germanium detector cryostat. The temperature of the out-flowing gas/liquid from the cryostat is monitored using platinum resistor thermometer. The program allows for automatic filling at regular intervals with temperature monitoring from a remote terminal.     

Control system for small automatic telescopes (ATs)

Summary The present paper illustrates some aspects of particular significance which result from applied research in the field of small, medium-size and large telescopes, to implement a reliable technological system capable of handling in an autonomous manner remotely loaded astronomical observation program. Because of their specific applications, the automatic telescope (AT) must be highly reliable. In this case, the term reliability is intended in its widest sense, that is, as quality and continuity of service of all the component subsystems. The integration of engineering, information science, mechanics, and, of course, astrophysics expertise is of primary importance. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

变形镜驱动器参数自动标定系统的设计

变形镜驱动器各通道的offset参数和gain参数直接影响到变形镜驱动器输出电压的精度,采用人工方式对其进行标定,不仅效率低,费时费力,而且参数的一致性也无法得到保证。为此,首先设计了AD采集器,其内部仅含一片24bit的高精度AD采集芯片,其并行的16端子输入接口通过继电器与采集芯片相连,内含的微处理器负责完成输入通道切换、采集时序控制和采集数据上传等功能;同时,还设计了上位机应用程序,实现了对变形镜驱动器以及AD采集器通信链路检查、标定过程控制参数设置、采集通道切换以及数据处理等相关操作命令和状态数据的收发,使得变形镜驱动器、AD采集器和上位机组成一套驱动器参数自动标定系统。结果表明,该系统不仅使得一套变形镜驱动器参数标定时间由原来的两个工作日缩短到2小时左右,而且提高了参数标定精度和一致性,其96通道零电压的最大误差由18.2mV降为13.5mV,均方差由原来的6.2mV降低为4.3mV,其输出最高电压120.000V的最大误差由23.4mV降为17.5mV,均方差由原来的10.1mV降低为8.3mV。     

Fully automatic system for the coupling alignment of optical fibres

To realize the low-loss connection of two optical fibres intended as a transmission medium for optical signals, very tight tolerances have to be observed on account of the small geometrical dimensions involved. The present work describes a fully automatic system for the alignment of optical fibres in thex-y planes relative to a light source, which has only a single intensity peak, so that maximum optical power is launched into the fibre. The light source can be, for instance, the radiating end of a fibre, a semi-conductor laser or a light-emitting diode. The optical power coupled into the fibre serves as the control signal. Three precision displacement stages driven by stepping motors serve to align the fibres. Various sequential control algorithms for optimal coupling are investigated with reference to theory. Two algorithms are tested with the aid of a computer with reference to the alignment accuracy and speed requirements which have to be met and the one shown by theoretical simulation to be the more favourable is selected for technical realization. The resulting system was used for numerous alignment operations for the coupling of two graded-index fibres. The alignment time is below 1 s and the coupling efficiency compared with manual coupling alignment efficiency (= 100%) is above 99%, corresponding to an additional loss of <0.05 dB.     

硅光电倍增管自动增益校正系统设计

温度会使硅光电倍增管的增益产生较大的漂移,进而影响硅光电倍增管的增益精度。为了使硅光电倍增管增益不随温度发生较大变化,设计了硅光电倍增管的自动增益校正系统,包括基于单片机的高压电源设计与采集系统设计。高电压模块精确工作的温度范围为?10～60 ℃,电源噪声约为30 mV,满足硅光电倍增管性能测试的需求。采集系统经过扫频测试与激光照射测试,可以较好地通过60 MHz的交流信号,并将光信号转变为较明显的电信号。该系统可以向京邦公司的硅光电倍增管阵列JARY-TP3050-8X8C提供工作电压与采集电路。     

载人航天器自动化测试系统设计与应用

针对现有航天器测试不具备流程化、自动化程控的问题,提出了一种载人航天器自动化测试系统。该系统以测试项目模块化思想为依托,提供了测试子项目设计平台,自动生成测试程序、测试细则文档,自动执行测试程序并实现无人值守,在出现异常时根据程序设计自主跳转或等待人工决策,实时记录测试过程信息,测试结束后自动生成测试报表并评估当前测试是否有效通过。对系统方案、接口方式、部署及管理模式进行了分析,通过型号测试进行了试验验证,该系统实现了测试各阶段流程化、自动化程控,提高了测试效率。     

激光共焦球面元件姿态自动调整系统

为解决激光差动共焦元件参数测量系统中人工调整元件姿态效率低、重复性差的问题，研制了激光共焦球面元件姿态自动调整系统。基于共焦原理，建立了元件失调量与电动四维调整机构调整量关系的数学模型，并根据CCD探测器实时获取的光斑位置信号分析出被测件的姿态信息，结合闭环反馈控制算法实现姿态自动调整。利用电动四维调整机构搭建了自动调整实验装置，实验结果表明:研制的电动调整机构平移调整分辨力达到0.5 μm，倾斜调整分辨力达到8″；调整系统能够快速、稳定地将被测件姿态失调量调至误差范围内，有效提高调整重复性及效率，对激光差动共焦测量系统实现全自动球面元件参数检测格外重要。     

On the asymptotic behavior of dynamical maps for a finite quantum system

We give some remarks on the dynamical evolution (also nonlinear) of finite quantum system. We are interested int-asymptotic behavior of density matrices in the Liouville space formalism and we show that for nonlinear dynamical semigroups, as well as for the dynamical maps that do not form semigroups, the stationary time evolution may be attained for finite time in contrast to the motion generated by the linear dynamical semigroup. Recently the problem of constructing a nonlinear analog of quantum mechanics with nonlinear wave equation playing the role of the Schrödinger equation has been investigated by some authors; see for example Mielnik (1974), Bergmann (1968). Our work is related to this investigation and gives a characteristic feature of the nonlinear time evolution.     

MEMS矢量水听器灵敏度自动测试系统设计

针对微机电系统(MEMS)矢量水听器声压灵敏度测试中出现的测试步骤单一、测试任务繁重且耗时多,同时手动测量存在不确定的操作误差等问题,在分析矢量水听器灵敏度测试原理和测试过程的基础上,采用AD9850,AD8599,PGA205、单片机MK60DN512ZVLQ110等芯片,设计了集成信号激励源、微弱信号检测、调理以及信号采样和传输等模块的矢量水听器灵敏度自动测试装置。该装置将测试现场的仪器缩小,多模块功能集成,通过与PC上位机连接控制,快速、实时地完成矢量水听器灵敏度测试标定,在节约测试时间的同时,也能快速地完成对水听器的优化改进的验证;此装置体积小、轻便,测试连线简单,方便外场测试,促进MEMS水听器工程化应用。     

MEMS矢量水听器灵敏度自动测试系统设计

针对微机电系统(MEMS)矢量水听器声压灵敏度测试中出现的测试步骤单一、测试任务繁重且耗时多,同时手动测量存在不确定的操作误差等问题,在分析矢量水听器灵敏度测试原理和测试过程的基础上,采用AD9850,AD8599,PGA205、单片机MK60DN512ZVLQ110等芯片,设计了集成信号激励源、微弱信号检测、调理以及信号采样和传输等模块的矢量水听器灵敏度自动测试装置。该装置将测试现场的仪器缩小,多模块功能集成,通过与PC上位机连接控制,快速、实时地完成矢量水听器灵敏度测试标定,在节约测试时间的同时,也能快速地完成对水听器的优化改进的验证;此装置体积小、轻便,测试连线简单,方便外场测试,促进MEMS水听器工程化应用。