中国当代壁画的“缺席”与“在场”

从中国当代壁画的主题、表现语言、政府的支持程度等不同层面进行了论述,梳理、分析了其中的问题所在.与其他艺术相比,中国当代壁画总是处在一种＂缺席＂的状态,中国当代壁画要想获得重新＂在场＂的契机,必须剖析其本身从形式到公众性缺失等方面的诸多问题.     

电离层电波信号衰减的混沌时间序列预测

电波信号穿过电离层传播时,由于电离层的作用将使得电波信号产生一系列的失真.分析了传统混沌时间序列预测的理论和方法,并分析了电波信号穿过电离层的时间序列特征,发现该时间序列具有混沌时间特征,进而在传统的混沌时间序列预测的基础上,给出了一种更适合于电离层电波衰减时间序列预测的方法.同时,利用它预测了一组电波信号穿过电离层的时间序列特征,并分析了其预测精度.结果表明,利用修正的混沌时间序列预测方法预测的电波信号穿过电离层衰减的时间序列,其短期的预测效果很好.     

HSV空间特征和纹理特征的阴影检测算法研究

为了提高检测和跟踪算法的准确性,提出了一种基于阴影在HSV空间下的特点和纹理特征的阴影检测与去除算法。该算法针对阴影区域覆盖的地面和未被阴影区域覆盖的地面纹理特征基本不变的特点,先检查序列图像中的运动区域,然后在运动区域内,根据阴影在HSV空间下的特点和纹理特征对阴影进行检测与去除,为运动目标的后续处理排除阴影干扰。实验结果表明,该算法能够很好地抑制噪声,有效检测、去除图片中运动目标的阴影。     

多体系统理论的数控滚齿机综合空间误差建模

为提高数控滚齿机床的加工精度,结合自行设计的数控滚齿机床,利用近年来研究数控机床误差建模的新方法—多体系统理论对六轴滚齿机床进行几何误差分析,建立综合空间误差模型,得到综合空间误差变化规律。为利用数控误差补偿方法提高滚齿加工精度提供理论支持。     

Method to generate training samples for neural network used in target recognition

Training neural network to recognize targets needs a lot of samples.People usually get these samples in a non-systematic way,which can miss or overemphasize some target information.To improve this situation,a new method based on virtual model and invariant moments was proposed to generate training samples.The method was composed of the following steps:use computer and simulation software to build target object’s virtual model and then simulate the environment,light condition,camera parameter,etc.;rotate the model by spin and nutation of inclination to get the image sequence by virtual camera;preprocess each image and transfer them into binary image;calculate the invariant moments for each image and get a vectors’ sequence.The vectors’ sequence which was proved to be complete became the training samples together with the target outputs.The simulated results showed that the proposed method could be used to recognize the real targets and improve the accuracy of target recognition effectively when the sampling interval was short enough and the circumstance simulation was close enough.     

Research on vertical deformation during construction of Shanghai World Financial Center

Shanghai World Financial Center is one of the highest buildings in the world, of which cumulation of vertical deformation during construction is significant and worth investigating. A refined finite element model was developed to conduct full-process analysis of construction of super-high rise buildings like Shanghai World Financial Center, in which the discrete analysis method of time-varying structures and age-adjusted effective modulus method were both used. In the finite element analysis, the whole construction process was divided into a series of stages, each with a structural system that is a part of the whole structure and with different material parameters, geometrical parameters, loading and boundary conditions. The whole construction process of Shanghai World Financial Center in consideration of creep of concrete was simulated successfully by using the finite element model and the analytical method developed. With respect to different construction stage, the total vertical deformation, inter-floor compression deformation and the relative deformation between the outer frame and the core-wall were obtained through the analysis. The comparison between the results from the stage-wise full-process analysis of construction with and without considering the creep and the results from the conventional analysis of the whole building under the total load from all self-weight and construction applied to the structure "in one go" shows that the cumulative effect on the deformation from the construction process and the creep effect need to be considered in analyzing the deformation of Shanghai World Financial Center, and the super-high rise buildings suchlike. Finally, the simulation results correlate well with the monitoring results-a proof of the feasibility and the validity of this paper.     

Enhancing pose accuracy of space robot by improved differential evolution

Due to the intense vibration during launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the real pose (including position and orientation) of the end effector not to match the desired one, and further hinder the space robot from performing the scheduled mission. To improve pose accuracy of space robot, a new self-calibration method using the distance measurement provided by a laser-ranger fixed on the end-effector is proposed. A distance-measurement model of the space robot is built according to the distance from the starting point of the laser beam to the intersection point at the declining plane. Based on the model, the cost function about the pose error is derived. The kinematic calibration is transferred to a non-linear system optimization problem, which is solved by the improved differential evolution (DE) algorithm. A six-degree of freedom (6-DOF) robot is used as a practical simulation example, and the simulation results show: 1) A significant improvement of pose accuracy of space robot can be obtained by distance measurement only; 2) Search efficiency is increased by improved DE; 3) More calibration configurations may make calibration results better.     

基于模糊层次分析法的公共建筑综合效益评价研究

针对公共建筑效益评价研究现状,提出对于公共建筑的评价更应当注重包括经济、社会、环境效益的综合效益评价．为此,应用模糊综合评判方法构建了公共建筑综合效益评价模型,并以徐州市奥体中心项目为例进行了实证研究．研究表明：将模糊综合评判方法应用于公共建筑综合效益评价,其评价结果真实可靠,具有较强的实用性和良好的应用价值．     

爱伦·坡《阿芒提拉多的酒桶》的哥特空间批评

爱伦·坡的《阿芒提拉多的酒桶》是一部充满哥特色彩的短篇小说。该小说采用谋杀者蒙特利瑟自述的形式,讲述50年前他对弗图那多的谋杀,呈现了阴森酒窖里性格扭曲的蒙特利瑟活埋弗图那多的恐怖画面。借助当代文学批评理论中的空间话语研究该短篇小说中的哥特书写,从建筑场景、人物并置和叙事特征方面分析小说哥特空间的构建,进一步突出故事的哥特主题——恐怖、扭曲和死亡。     

优化玻璃熔窑底烧式喷枪仰角的数值模拟研究

采用数值模拟的方法对某浮法玻璃熔窑底烧式喷枪的安装仰角进行模拟优化,具体从熔窑火焰空间温度分布、燃烧效率、玻璃液面热流量和碹顶温度分布等角度来对喷枪仰角为0°、3°、5°、7°、9°、11°、13°这7种情况进行对比分析。研究结果表明:喷枪安装仰角的增大有利于燃料和助燃气体的充分混合和燃烧,但当仰角大于5°时,角度的增大对燃烧效率和平均温度影响不大;仰角的增大对碹顶温度分布影响不大,喷枪仰角为3°和5°,传递给玻璃液面的热量较多。因此,此熔窑的天然气喷枪仰角的可调节范围较大,仰角为5°时的燃烧状况较好。