IBR技术与应用综述

IBR技术是一种全新的用于产生真实感图像的技术,主要应用于虚拟实景空间建立,虚拟实景空间漫游和虚拟对象展示。与传统的技术相比,IBR技术的优势主要在于图像的真实性,实时性和与用户的交互性。本文主要介绍了几种常用的IBR技术,以及IBR技术的主流应用,并进行一定的分析比较,总结了IBR技术发展的基础和关键问题。     

Mathematical model of deoxidization with post stirring in a combined blowing converter

Dissolved oxygen in the steel at the terminal of the converter smelting process is the main cause for the formation of oxide inclusions, and the high terminal oxygen content worsens the steel cleanness. However, post stirring in a combined blowing converter can promote the carbon-oxygen reaction in the liquid steel and reduce the dissolved oxygen content at the terminal of the converter smelting process. Thus, the mathematical model of deoxidization in the post stirring process was obtained, and the rationa...     

Establishmen and vertification of an improved similitude law for dynamic ice force model test

To study the similitude laws for dynamic ice force model test which is a hot problem in ice mechanics.In this paper,a new modified similitude law for dynamic ice force model test is proposed based on ice-induced virbration theory and two reasonable assumptions.And the new law is vertified with an ice-induced pier virbration example.The numerical calculation results show that,firstly,the error of frequency factor between test value and theory value is small as well as that of displacement and velocity;Secondly,the time scale completely meet the similitude relation,the waveforms anastomotic well,and the phenomenon of offset and omit do not occur;Thirdly,as the damping ratio between prototype and model is nearly equal,the improved similitude law will still be applied.Therefore,the new modified similitude law is feasible to study dynamic ice force model test and can provide reference for the ice mechanics.     

A force control high-order single-step-β method (HSM) for substructure pseudo-dynamic testing

This paper proposes a new technique which introduces the high-order single-step-β method(HSM)into the experimental study on the substructure pseudo-dynamic testing(SPDT).The technique is based on the proposed concept of equivalent shear stiffness which can meet the requirement of the HSM algorithm.A study is done to theoretically validate the technique by the numerical analysis of two-storey shear building structure,in comparison of the proposed substructure pseudo-dynamic testing algorithm with the central difference method(CDM).Then,a full-scale SPDT model,the three-storey frame-supported reinforced concrete short-limb masonry shear wall structure,is designed and tested to simulate the seismic response of the corresponding six-storey structure and verify the proposed force control HSM technique.Meanwhile,the techniques of both stiffness correction and force control are suggested to control algorithmic error,control error and measurement error.The results indicate that the force control HSM can be used in the full-scale multi-degree-of-freedom(MDOF)substructure pseudo-dynamic testing before descent segment of structure restoring force properties.     

Constitutive model for shape memory alloy torsion actuator

Shape memory alloy ( SMA) torsion actuator is one of the key approaches realizing adaptive wings in airplanes. In this paper,the actuator is made up of SMA wires and a thin-walled tube,in which the SMA wires are twisted and affixed around the surface of the tube at an angle referenced to the center axis of the tube. A thermo-mechanical constitutive model is developed to predict the thermo-mechanical behaviors of the SMA torsion actuator based on the knowledge of solid mechanics. The relationship between the torsion-angle and tem- perature is numerically calculated by using the thermo-mechanical constitutive model coupled with the SMA phase transformation model developed by Zhou and Yoon. The numerical results are compared with the relative experimental results finished by Xiong and Shen. Influences of the twist-angle of SMA wires and geometrical factors on the primary actuation performances of the SMA torsion actuator are also numerically investigated based on the thermo-mechanical constitutive model coupled with the SMA phase transformation model developed by Zhou and Yoon. Results show that the thermo-mechanical constitutive model can well predict the thermo-mechanical behaviors of the SMA torsion actuator.     

两种群食饵-捕食者模型参数估计的数值微分法

给出了一种基于数值微分的两种群食饵-捕食模型参数估计的两阶段方法。该方法将参数的非线性最小二乘估计,转化为一个数值微分和一个线性最小二乘估计问题,具有计算简单快速的特点。数值算例详细分析了三种常见有限差分数值微分法及非线性最小二乘估计对参数估计精度的影响,结果表明提出的方法是可行的。     

基于模块化模型的自适应预失真技术

系统地比较和分析了OFDM传输系统里高功率放大器（HPA）预失真方法的优缺点,提出一种基于模块化模型的有记忆高功率放大器自适应数字预失真方法,该方法分别基于Wiener、Hammerstein和Wiener-Hammerstein模型各自构成一个有记忆HPA的自适应预失真器。从而避免了因分别估计Wiener-Hammerstein模型各个环节特性参数所带来的复杂性。使得有记忆高功率放大器的预失真设计变得简单了。     

考虑品牌影响的建筑企业顾客满意度模型

根据建筑施工项目的特征提出一个考虑品牌影响的建筑施工企业顾客满意度理论模型。在收集建筑施工企业顾客样本数据的基础上,利用结构方程模型软件对理论模型作了检验。研究结果表明：企业品牌对顾客满意度和顾客忠诚度均具有显著性影响;顾客感知质量对顾客满意度、顾客感知价值对顾客忠诚度、顾客期望对顾客抱怨、顾客满意度对顾客忠诚度具有显著性的影响;顾客期望对顾客抱怨、顾客满意度对顾客忠诚度有正面影响。研究结论具有较高的精度,模型对目标建筑施工企业顾客满意度和忠诚度有较好的解释力。     

大功率TEM法在锡铁山矿区深边部找矿中的应用效果

锡铁山铅锌矿区大功率TEM法深边部找矿研究发现,除少数异常在老地层上以外,几乎所有的异常均在滩间山群上。03线2 942 m标高走向坑道勘探发现了隐伏Ⅳ矿带片岩型矿床,与2000年发现的TEM异常吻合,从而明确了TEM法在锡铁山深边部找矿的指导意义。TEM响应电位异常曲线反映规则低阻形体的异常特征,如陡产状厚板状低阻体的双峰盖帽特征、缓产状板状低阻体的箱形或似箱形特征等,构成低阻形体的物理模型。勘探验证结果是铅锌矿体与近矿局部炭质层和黄铁矿体组成的宏观低阻形体,可视为矿床的地质模型。这两个模型是客观存在事物的两个侧面表现,它为识别矿致异常提供了科学依据。     

图像质量快速盲检测及其在视觉系统中的应用

提出了一种新的图像质量快速盲检测方法,以锐利度作为图像质量准则,而锐利度可以归结为图像的模糊特性,并由边缘信息估计得到。为了提高系统效率,采用边缘对比度的估计方法,并以边缘对比度作为边缘锐利度的判据准则。分析了邻近边缘的相互影响,因而只需从有限的边缘点来提取出合理的线扩展函数(LSF),进而得到模糊参数。在LSF计算中,采用一种新的插值计算方法。实验结果表明:当图像不是特别模糊时,测量结果是准确的。