Real-time homogenous translucent material editing

This paper presents a novel method for real-time homogenous translucent material editing under fixed illumination. We consider the complete analytic BSSRDF model proposed by Jensen et al. [ [JMLH01] ], including both multiple scattering and single scattering. Our method allows the user to adjust the analytic parameters of BSSRDF and provides high-quality, real-time rendering feedback. Inspired by recently developed Precomputed Radiance Transfer (PRT) techniques, we approximate both the multiple scattering diffuse reflectance function and the single scattering exponential attenuation function in the analytic model using basis functions, so that re-computing the outgoing radiance at each vertex as parameters change reduces to simple dot products. In addition, using a non-uniform piecewise polynomial basis, we are able to achieve smaller approximation error than using bases adopted in previous PRT-based works, such as spherical harmonics and wavelets. Using hardware acceleration, we demonstrate that our system generates images comparable to [ [JMLH01] ]at real-time frame-rates.     

火灾后钢筋混凝土结构强度损伤的分析与计算

以单筋矩形截面梁为例,从分析计算构件的温度场着手,介绍了火灾后钢筋混凝土结构残余强度的计算方法,从而为确定其受损建筑物继续使用的安全性和进行加固补强提供理论依据。     

真空阴极弧离子镀类金刚石碳（DLC）膜的碳弧稳定性研究

选用氩气、氩气加氢气、氩气加乙炔等气体作为介质，石墨作为靶材进行真空阴极弧离子镀来制备类金刚石碳膜。石墨电弧有其独特的电弧特性曲线，不同气体介质对碳弧特性的影响不同，磁场的大小对电弧的稳定性有很大作用，碳弧下基片偏流随电弧电压的增加而减小，试验得到表面光滑的类金刚石碳（DLC）膜，对膜的表面进行了SEM分析。     

一种接入信息高速公路的新技术ADSL

新近出现的非对称数字用户线（ＡＤＳＬ）技术利用用户网中现有的铜双绞线提供１．５～６Ｍｂ／ｓ的下行数字信道，为接入信息高速公路提供了一条新途径，本文首次论述ＡＤＳＬ的基本概念，技术，发展现状和应用，最后论述我们对发展我国ＡＤＳＬ接入设备的几点建议。     

“磁约束”的防垢、除垢机理分析

讨论了轴对称非均匀磁场对带电粒子的作用，分析了“磁约束”对防垢、除垢的微观机理，指出满足磁约束理论的轴对称非均匀磁场的防垢，除垢效果好的原因，正是由于在这种磁场中，带电粒子的运动被约束在一定磁面上的某一磁感应线附近做以该磁感应线为中心的螺旋运动，且正、负离子的回旋方向相反，从而形成内部相互作用较弱的大分子簇团不易吸附在管壁上，达到防垢目的；磁化水的渗透压较大，可起到除垢效果。     

Research on resolution between multi-component LFM signals in the fractional Fourier domain

When the initial frequencies and chirp rates of multi-component linear frequency modulation (LFM or chirp) signals are close,the signals may not be distinguished in the fractional Fourier domain (FRFD).Consequently,some signals cannot be detected.In this paper,first,the spectral distribution characteristics of a continuous LFM signal in the FRFD are analyzed,and then the spectral distribution characteristics of a LFM signal in the discrete FRFD are analyzed.Second,the critical resolution distance between the peaks of two LFM signals in the FRFD is deduced,and the relationship between the dimensional normalization parameter and the distance between two LFM signals in the FRFD is also deduced.It is discovered that selecting a proper dimensional normalization parameter can increase the distance.Finally,a method to select the parameter is proposed,which can improve the resolution ability of the fractional Fourier transform (FRFT).Its effectiveness is verified by simulation results.     

基于互联网图像集的室外场景建模技术综述

目前在互联网上有海量的室外场景照片,它们不仅内容覆盖面广,对同一场景有大量不同视点和光照条件下的采样,而且获取成本很低.如何利用这些照片中包含的丰富场景信息,快速、方便地构造各种逼真的虚拟场景,是互联网迅猛发展给虚拟现实、计算机图形学和计算机视觉带来的新的研究课题之一.文中分析、总结了近年来国内外互联网图像的真实场景几何建模、自然光照建模和材质反射属性建模的最新研究进展,并对其未来的发展趋势提出了一些看法.     

基于Ad Hoc网络的SMR优化算法的研究

SMR是一种基于DSR算法的多路径路由算法,这种算法的本身具有明显的局限性。第一,它可能在存在多条不相关多路径路由的情况下选择两条相关多路径路由作为最后的主路由与备份路由;第二,它在目的节点只收到一个RREQ分组的情况下只生成一条主路由,而实际可能存在多条传输线路。针对SMR算法的局限性,本文提出一种改进的SMR算法—ISMR,该算法保证了两条路由的形成,保证了在存在多条不相关多路径路由情况下,一定会生成两条不相关多路径路由。     

基于模型设计的数字集群分组数据业务的实现

为解决数字集群通信系统中图像、视频等大数据业务的传输问题,深入分析数字集群空中接口协议栈的结构,重点研究分组数据业务提供者子网相关汇聚协议的结构和原理。基于模型设计方法设计该协议的相关功能模块,并进行编码实现。开发中使用IBM Rational Rhapsody这一基于UML建模的开发工具,使整个开发过程简洁而清晰。最后,通过对协议进行一致性测试,证明协议参数及流程符合数字集群通信系统协议标准。