功耗限制下高频功率变压器动态模型的研究

当采用计算机仿真进行开关电源设计时,变压器模型的精度对仿真结果的影响是非常大的;尤其当开关频率较高时,现有磁性器件模型因无法描述绕组的趋肤效应、磁芯材料的非线性等,而使得仿真精度急剧下降。本文提出了一种功耗限制下的动态变压器模型,在仿真运行期间其参数可根据工作温度的变化由软件动态调整,使得该模型能够很好地描述在不同工作温度下物理器件的特性,具有良好的精度。同时利用该模型可在仿真中得到变压器的功率损耗大小和温度变化曲线。     

航空升压式空气循环制冷组件动态特性的仿真研究

详细描述了航空升压式空气循环制冷组件的工作原理。建立了该组件中压气机、涡轮、转轴以及中间冷却器的非线性动态模型。根据部件动态特性的不同时间尺度,分别考虑气体的压力、温度以及转轴转速随时间的变化过程。在MATLAB/SIMULINK系统仿真环境下,采用模块化的建模思想开发了该组件的动态仿真工具箱。以某型飞机环境控制系统的升压式空气循环制冷空气循环制冷组件为例,进行了仿真计算并给出系统的稳态结果和动态过程分析。     

乘数-加速数模型的稳定性与宏观调控政策

利用我国统计数据，建立了一个修正的萨缪尔森(Samuelson)乘数一加速数模型．在此基础上，对我国宏观经济系统的稳定性、能观性、能控性进行了讨论，结果表明，经济系统从不稳定到稳定需要加大消费和投资的力度，尤其应该刺激消费．从一个侧面论证了我国近年来宏观经济调控政策的正确性．     

A Dynamic Object Behavior Model and Implementation Based on Computational Reflection

A dynamic object behavior model based on computational reflection is proposed. This model consists of function level and meta level, the meta objects in meta level manage the base objects and behaviors in function level, including dynamic binding and unbinding of base ohject and behavior. We implement this model with RoleJava Language. which is our self linguistic extension of the Java Language. Meta Objects are generated automatically at compile-time, this makes the reflecton mechanism transparent to programmers. Finallyan example applying this model to a banking system is presented.     

Intermediate view synthesis from stereoscopic images

1.INTRODUCTION Stereoscopicimagesandvideohavebeensuccessfully exploitedinmedicine,remoteguidance,computer aideddesignandentertainmentforaboutadecade[1].Inrecentyears,withthedevelopmentof3Dtech niques,somenewfunctionsaredemandedforsuch systems.Oneofthedesirablefunctionsisthe“con tinuouslook around”-visualizationof3Ddataonthe screenfromdifferentviewingangles.Theviewer shouldbeabletoacquirecorrespondingviewswhen hemoveshishead.Thisisequivalenttopositioninga stereocamerainthe3Dsceneinaccor…     

高等学校管理效果的Markov理论分析

运用科学的发展观,研究学校可持续发展战略,给领导决策提供科学依据,是学校管理科学化的要求.利用Markov链的理论对高校教师职称结构和教学改革效果进行了量化动态分析,解决了直观认识的不准确性.     

Radiation embryology

Summary Prenatal development, characterized by intensive cell proliferation, cell differentiation and cell migration, shows a high radiosensitivity. Therefore, radiation exposure of embryos and fetuses is of great concern for radiological protection and human health. Irradiation during gestation can cause death, growth disorders, malformations, functional impairment and malignant diseases in childhood. These effects are strongly dependent on the developmental stage at exposure and on the radiation dose. The first trimester of pregnancy is regarded as the period with the highest risk for malformation and cancer induction. The developing nervous system shows a special susceptibility to ionizing radiation over a long period and is therefore of great significance for risk estimation. Knowledge about radiation effects on prenatal development has been derived from animal experimentation and from the exposure of human embryos. There is evidence that doses between 1 and 10 cGy may lead to developmental anomalies and that the radiation response can be modified by additional factors.     

在VB中调用MATLAB的方法及其在测量数据处理中的应用

介绍了在VB中调用MATLAB常用的三种方法的原理,并以实际测绘数据处理为例详细介绍了利用DDE技术在VB中调用MATLAB的实现过程,实现了数据处理与图形显示一体化.     

电气比例压力阀动特性的改进

在电气比例压力阀原结构中引入反馈通道可以改善它的稳定性．运用控制理论推出了改进后比例压力阀的数学模型．在高精度控制场合运用ＦｕｚｚｙＰＤ调节器来提高系统的响应速度，响应时间只有１ｍｓ．     

DHTML技术的研究与应用

介绍了基于脚本语言JavaScript的Dynamic hyper text markup language(DHTML)的技术进行了分析，讨论了其特点及在未来的页面上的应用，阐述了活用这些页面技术来实现一些页面效果设置，并以创建新窗口为例模拟Windows系统的部分实现．