Isotropic Evolution of a JBD Anisotropic Bianchi Universe

I study the dynamical effects due to the Brans-Dicke scalar -field at the early stages of a supposedly anisotropic Universe expansion in the scalar-tensor cosmology of Jordan-Brans-Dicke. This is done considering the behaviour of the general solutions for the homogeneous model of Bianchi type VII in the vacuum case. I conclude that the Bianchi-VII₀ model shows an isotropic expansion and that its only physical solution is equivalent to a Friedman-Robertson-Walker spacetime whose evolution can, depending on the value of the JBD coupling constant, begin in a singularity and, after expanding (inflating, if > 0), shrink to another, or starting in a non-singular state, collapse to a singularity. I also conclude that the general Bianchi-VII _h (with h 0) models show strong curvature singularities producing a complete collapse of the homogeneity surfaces to 2D-manifolds, to 1D-manifolds or to single points. Our analysis depends crucially on the introduction of the so-called intrinsic time, , as the product of the JBD scalar field times a mean scale factor a ³ = a ₁ a ₂ a ₃, in which the finite-cosmological-time evolution of this universe unfolds into an infinite -range. These universes isotropize from an anisotropic initial state, thence I conclude that they are stable against anisotropic perturbations.     

An Approach to Early Prediction of Software Quality

Due to the rapid development of computers and their applications,early software quality prediction in software industry becomes more and more crucial. Software quality prediction model is very helpful for decision-makings such as the allocation of resource in module verification and validation. Nevertheless,due to the complicated situations of software development process in the early stage,the applicability and accuracy of these models are still under research. In this paper,a software quality prediction model based on a fuzzy neural network is presented,which takes into account both the internal factors and external factors of software. With hybrid-learning algorithm,the proposed model can deal with multiple forms of data as well as incomplete information,which helps identify design errors early and avoid expensive rework.     

预警的概念及相关物理问题

预警是现代社会减轻自然灾害的工作中最重要的物理概念之一,也是在预测/预报的物理问题没有得到解决的情况下最具实际意义的技术之一.文章介绍了与预警有关的概念和物理问题,包括预报和预警的概念,现地预警和异地预警,讨论了不同领域的预警技术中共同的物理问题,包括“有限传播”原理、“连锁效应”原理、“相似放大”原理,以及实际工作对预警系统的主要技术要求.     

光纤延迟线长度编码优化设计

在光纤延迟测向激光告警系统中，光纤延迟线是用来连接光学接收系统和光电转换系统的．起到传输光、延迟光、对光信号进行编码的作用。由于光纤延迟线的长度不同，光学窗口接收到的激光脉冲产生不同的时间延迟．从而实现激光方位信息到时间信息的转变。光纤延迟线的长度对激光告警器的体积、光学损耗、虚警率等因素有着直接的影响，在此利用激光脉冲的相关特性，通过最优化理论对光纤延迟线进行排列组合．提出了光纤延迟线长度编码的优化设计方法，通过对相关理论的分析与计算．得到了一个全向矩阵的排列方式，从而得出了相应的排列原则。按照该原则对光纤延迟线进行排列组合，从理论上得到了最优的光纤延迟线总长度值，为激光测向告警器的优化设计提供了重要的理论依据。     

"解剖"激光告警

介绍了激光告警的作用,分析了激光告警器的原理、性能要求和分类,然后分别阐述了典型的光谱识别型、相干识别型和散射探测型激光告警器,并对不同类型的激光告警器进行了比较评价.     

医院感染实时监测和预警系统在临床护理中的应用效果调查

目的 :对医院感染实时监测和预警系统在临床中的应用效果进行分析和研究。方法 :所选用B/S构架及J2EE的新开发技术,后台的数据库系统是以SQL SERVER为主,后台的数据库系统是可以与目前各个医院信息系统相连接的,是医院感染管理信息系统得到有力的开发。结果 :对医院感染所发生的发病情况和因素进行实时监测和预警系统,可以起到有效安全的检测和统计功能。结论 :通过对医院感染进行实时的检测和预警系统在临床中的实践应用效果,使医院感染检测的安全性和准确性得到充分的提高,同时也大大提高了医院感染管理的质量和效果。     

移动通信网的公共预警系统研究

文中根据公共预警系统的需求提出了几种基于移动通信网络的ETWS的解决方案.基于公共预警系统对速度的需要和优化的信息传送的特征,分析了公共预警系统的各项需求,给出预警通知提供方和移动通信网络的信息交互过程,并基于现有的移动通信网络,提出了带特殊IMSI寻呼的CBS、增强的CBS和E-MBMS三种解决方案.其中,增强的CBS方案更为符合全球的需求.     

Driven torsion pendulum for measuring the complex shear modulus in a steady shear flow

To investigate the viscoelastic behavior of fluid dispersions under steady shear flow conditions, an apparatus for parallel superimposed oscillations has been constructed which consists of a rotating cup containing the liquid under investigation in which a torsional pendulum is immersed. By measuring the resonance frequency and bandwidth of the resonator in both liquid and in air, the frequency and steady-shear-rate-dependent complex shear modulus can be obtained. By exchange of the resonator lumps it is possible to use the instrument at four different frequencies: 85, 284, 740, and 2440 Hz while the steady shear rate can be varied from 1 to 55 s^–1. After treatment of the theoretical background, design, and measuring procedure, the calibration with a number of Newtonian liquids is described and the accuracy of the instrument is discussed.Notation a radius of the lump - A geometrical constant - b inner radius of the sample holder - c constant - C ₁, C ₂ apparatus constants - D damping of the pendulum - e _x , e _y , e _z Cartesian basis - e _r , e , e _z orthonormal cylindrical basis - E geometrical constant - E _t , ⁰ E _t , _t relative strain tensor - f function of shear rate - F _t relative deformation tensor - G (t) memory function - G ^* complex shear modulus - G Re(G ^* ) - G Im(G ^* ) - h distance between plates - H ^* transfer function - , functional - i imaginary unit: i ²= – 1 - I moment of inertia - J _exc excitation current - J ₀ amplitude of J _exc - k ^* = k – ik complex wave number - K torsional constant - K fourth order tensor - l length of the lump - L mutual inductance - M _dr driving torque - M _liq torque exerted by the liquid - ⁰ M _liq, _liq steady state and dynamic part of Mliq - n power of the shear rate - p isotropic pressure - Q quality factor - r radial position - R,R ₀, R _c Re(Z ^*, Z ₀ ^* , Z _c ^* ) - s time - t, t time - T temperature - T, ⁰ T, stress tensor - u velocity - U lock-in output - ₀ velocity - V _det detector output voltage - V _sig, V _cr signal and cross-talk part of V _det - x Cartesian coordinate - X , X ₀, X _c Im(Z ^*, Z ₀ ^* , Z _c ^* ) - y Cartesian coordinate - z Cartesian coordinate, axial position     

一种基于激光测距的汽车安全报警装置研究

为防止汽车与前方物体发生碰撞,使汽车始终在安全车速下行驶,减少事故的发生,设计了一种基于激光测距的汽车安全报警装置,它采取激光探测技术,是一种声光电一体的高科技、高智能汽车防撞产品,在出现跟车距离小于安全距离等紧急情况时,发出警报,提醒驾驶员注意并采取减速或制动措施,从而达到有效预防追尾碰撞事故发生的目的,提高了汽车的主动安全性能。测试结果表明,在输入报警距离与制动距离时,均能实现不同方式的报警。     

基于多智能体的编队协同空战战术规划

把编队看成一个多Agent系统,编队中的长机和僚机都看成是Agent。首先叙述了BDOTI-Agent的逻辑结构,然后提出基于多Agent的编队协同空战战术规划合作求解的方法,合作求解过程分为任务形成、合作产生、团队初步形成、任务分解、团队最终形成、角色指定和子任务分配、执行任务等7个阶段。最后举例说明了合作求解的过程。