面向船舶航行训练的大范围地形建模

大规模地形场景的实时绘制在虚拟现实、地理信息系统、战场仿真等领域有着广泛的应用。为满足船舶模拟训练系统中视景仿真的需求,对大规模地形场景的建模与实时绘制技术进行了研究。首先对比了几类常用数据插值方法,采用数据融合的方式对DEM数据进行了插值。通过结合模拟训练的实际,提出了一种基于可见性判断的地形剔除方法,通过放射状搜索,判断当前点是否遮挡,进而对被遮挡点进行剔除处理,可以有效减少地形建模中无关面片,提高绘制速率。利用Google Earth获取地形纹理,使用Terri Vista构建三维地形,实现了地形的三维建模。试验表明提出的方法可实现大规模地形场景的高效逼真绘制。     

实时动态场景生成

利用三维建模软件对目标和光电跟踪测量系统等实物建立三维模型,把捕获系统实时获取的目标状态信息和光电跟踪测量系统运行信息通过网络实时传送给场景生成计算机,场景生成计算机利用这些数据信息驱动三维模型,从而实时模拟目标与光电跟踪测量系统的运行状态。该系统可为指挥控制人员的决策提供更直观、简便的帮助。     

基于因果关系的实时告警关联系统

针对大规模网络环境下海量告警信息的重复性、不完整和不可管理给网络安全管理带来的新的挑战,提出了一种基于因果关系的实时入侵告警关联(RIAC)系统,以解决海量告警的实时关联和可视化管理问题.此RIAC系统利用分布式Agent实时地捕获和预处理告警信息,然后由因果关联引擎对其进行分析和处理,从而揭示告警信息背后隐藏的攻击场景和攻击意图.使用MIT Lincoln Lab提供的攻击场景数据集LLDOS1.0和真实IPv6数据集对该RIAC系统进行了测试,实验结果验证了其有效性和实时性.     

大规模3DGIS场景的多通道渲染算法研究

为了由多个计算机节点协同完成大规模三维地理信息系统(3DGIS)场景的渲染和显示,提出了一种基于分布式计算机体系结构的多通道渲染算法(3DGIS multi-channelrendering algorithm,GMCR)。三维地理信息系统同其他类似算法相比,该算法作了两项改进:(1)采用视锥组合计算方法将大规模三维场景分割为若干子场景并分配给不同计算机节点处理,可以保证场景拼接处的空间连续性和不变形性;(2)采用消息机制协调计算机节点的渲染处理与显示步调,以控制子场景的状态同步和显示同步。该算法简单易行、效果突出,利用多台低端设备实现了大规模3D场景渲染与显示,可以完成高端设备不能够实现的超大规模3D场景。以3DGIS城市交通系统演示环境实验为例,验证了该算法的可行性,结果表明GMCR方法可以支持多达185个计算机节点进行超大规模的3DGIS场景渲染。     

经纬仪测试场景仿真系统研究

虚拟测试场景的可视化仿真是经纬仪室内性能测试的重要手段,构建了虚拟测试场景仿真系统总体结构,该系统主要为虚拟测试提供三维虚拟场景和场景仿真图像.论述了虚拟场景仿真中基于目标运动特征的轨迹、姿态建模方法及背景云图模拟技术,图像仿真时目标姿态扰动模拟、灰度模拟及目标、背景图像实时合成等关键技术.采用VC++和OpenGL,开发了经纬仪虚拟测试场景仿真系统,应用表明,生成的三维场景、合成出的目标、背景图像及数据有效满足了经纬仪相关性能的测试需求.     

基于OpenGVS的汽车驾驶模拟器场景建模技术研究

在汽车驾驶模拟器视景系统的开发中,场景模型的建立和管理是非常重要的内容,直接影响到整个系统的沉浸感、交互性和实时性。根据系统要求主要使用MultiGen Creator建立了场景模型,采用OpenGVS对场景进行了驱动,提出了场景的组织和管理原则,并对其中的关键技术如场景导入、摄像机跟随、碰撞检测等进行了探讨。这些技术已在系统开发中获得成功应用,取得了较好的仿真效果。     

基于用户场景的装配式阳台装修系统设计研究

目的 构建一套基于用户场景的装配式阳台装修系统解决方案。方法 以装配式阳台系统体系构建为目标,从装配式阳台系统的设计方法、概念、架构、系统模块等方面,对装配式阳台系统进行全面系统的探讨。结果 得出装配式阳台系统由四大基装系统、八大选装系统、三大加载系统构成。结论 装配式阳台系统包括装配式阳台基装系统、装配式阳台选装系统、装配式阳台加载系统。其中基装系统包括:顶面系统、墙面系统、地面系统、封阳系统。选装系统包括:家政模块、晾晒模块、休闲模块、绿植模块、办公模块、健身模块、厨房辅助收纳模块、卧室辅助收纳模块。加载系统包括:智慧照明系统、智慧安防系统、智慧遮阳系统。随着“双碳”目标、大数据、人工智能、新型生活方式的发展,兼顾标准化、工业化、个性化、智能化的多元阳台生活场景的系统解决方案将会得到快速发展。     

以睡眠场景为例的智能家居场景模型构建研究

目的 构建智能睡眠场景模型,为智能家居场景研究提供参考.方法 运用扎根理论作为研究方法,搜集睡眠相关的品牌概念场景和用户使用场景作为原始资料.通过开放性编码与主轴性编码,提炼出智能睡眠场景维度与子项说明表.最终经过选择性编码将不同维度和子项组织起来.结果 得到智能睡眠场景模型.藉由关系图的形式阐释了场景各要素的相互关系,以及场景的作用机制.结论 智能家居场景分为有形场景与无形场景,共5个维度,18个子项.有形场景划分为空间要素、氛围要素和智能设备要素3个维度,他们构成了用户所在的物理空间.无形场景划分为数据要素和社会要素,分别为有形场景提供了"大脑"和"援助".它们互相影响、共同作用,为用户构建了居家智能场景体验.     

虚拟广告场景定位及广告牌模型库设计

设计了一个虚拟广告系统,即对场景和广告牌模型的创建和管理.通过3ds/Max制作少量简单模型,用MFC框架编写了一个含四个视图的模型编辑器,使用OpenGL图形库对模型进行处理,进行场景和广告牌建模,要求统一尺寸,并按规定的层次结构存放及一个与用户交互的编辑器,可以载入3ds文件格式的模型并随意改变模型的位置,大小和方向等,确定需要的场景后,可以保存退出.该编辑器用来保存场景和摄像机的位置信息至一个文件中,供以后将虚拟广告牌插入视频之用.该程序总体功能基本完成.     

大数据场景下的云存储技术与应用浅析

随着信息技术与科学的不断进步,信息网络越来越普及到人们的日常生活与工作中,而云计算则是当前网络发展过程中非常重要的组成部分。大数据场景的发展为云技术提供了广大的发展空间,对云技术的需求也在不断升高。本文以大数据场景的概述为研究基点,具体分析云存储的主要技术,并研究大数据场景下云技术的相关应用。     

基于虚拟现实技术的南京鼓楼建筑情景复原

为了复原南京鼓楼最初的建筑形制动态情景变化,提出一种基于虚拟现实技术,并结合Cinema 4D三维建模软件的情景化数字复原流程。首先,对南京鼓楼的周边环境、建筑构件、室内陈设等进行研究,在现有测绘资料的基础上,进行艺术化的情景再现设计,并利用三维建模技术,通过模型复原真实的建筑形制。然后,结合虚拟现实技术,实现明鼓楼建筑与观赏者的情景交互设计。南京鼓楼初建于明洪武年间,后因历史变迁,其建筑规模、等级、做法均发生较大变化,导致明初鼓楼在每一个复建阶段的建筑定位仍然含糊不清。最终,通过虚拟现实技术,使南京鼓楼建筑形制能够以可视化的形式得以保存。在虚拟过程中,提出了简化且真实的古建建模交互策略,让用户通过沉浸式体验,直观地感受古建复原、修缮的过程。     

Studies on diaminoglyoxime (DAG): thermolysis and evaluation as ballistic modifier in double base propellant

This paper reports thermolysis of diaminoglyoxime (DAG) and its evaluation as a ballistic modifier in double base propellant formulations. Differential scanning calorimetry (DSC) and simultaneous thermal analysis (DTA-thermogravimetric (TG)) revealed that DAG decomposes in two stages. Kinetics of initial stage of thermal decomposition of DAG evaluated from TG data gave activation energy (E(a)) of 153 kJmol(-1). The high-temperature Fourier transform Infrared (FTIR) spectra of DAG suggested preferential cleavage of NO and CNH2 during decomposition. Mass spectral data also suggest possibility of similar process. The hyphenated TG-FTIR data also revealed the evolution of gases containing species, such as CN, NH, OH and oxides of nitrogen during thermal decomposition. Evaluation of DAG as a ballistic modifier in RDX incorporated double base propellant formulations indicated that it brings down the pressure index to 0.17 compared to 0.79 for a control composition in the pressure range 6.9-8.8 MPa when used in combination with basic lead salycilate (BLS). The study suggests that combination of DAG and BLS need to be optimized to achieve more remarkable effects than BLS alone. It was observed that DAG does not have adverse effect on vulnerability and chemical stability of the propellant formulation.     

基于虚拟现实技术的测量数据可视化方法

在从数据可视化的角度对测量数据进行分类的基础上,对两种重要类型的测量数据给出了三维建模方法。然后利用CAVE技术和3D技术,结合以映射、绘制为主线的数据可视化基本流程,提出了一种具有沉浸感和立体感的通用型测量数据可视化方案。技术方案以建立三维模型为基础,以对视图的控制为核心,以场景设置为辅助,实现并验证了测量数据可视化。     

3D Presentation and Disassembly Simulation of Dougong based on Pro/E-VRML

The application of parametric modeling method of Pro/E in the modular dougong is researched,and the disassembly and assembly operation of the dougong is implemented through the collision detection by the coordinate method in VRML. Direct interaction of VRML scene at the Web is implemented by using Java Script to manipulate VRML Object DOM.     

基于VRML的航道虚拟场景应用研究

虚拟现实技术在诸多领域中展示了强大的功能,近年来随着水利工程的发展,该技术更多的应用于水工设计中。航道工程设计整治中的地形实景再现有助于更直观地进行航道线的确定和相关设施的布局,用 ArcInfo 实现地形面的三维建模,得到虚拟场景的对象。并用 VRML 及脚本创建虚拟的场景,可以较快地实现从离散地形数据到虚拟航道场景的浏览。     

Application of a Logarithmic Complementary Metal–Oxide–Semiconductor Camera in White-Light Interferometry

This paper describes the characterization, modeling, and application of a direct-readout complementary metal-oxide-semiconductor (CMOS) camera in white-light interferometry (WLI). The camera that was used consisted of a direct-readout 1024times1024 pixel logarithmic CMOS sensor. A continuous analog voltage from each pixel was converted to an 8-bit value by an internal analog-to-digital converter and processed with a digital signal processor. A mathematical model relating the input light intensity to the 8-bit digitized output is developed, which is critical in applications where knowledge of the scene intensity is essential to estimating the maximum allowable frame rates. The camera was utilized in WLI, and its application is analyzed in terms of maximum output signal amplitude, imaging speed, and light intensity. The mathematical modeling is implemented with SPICE simulations and verified with experimental data.     

Understanding Bidirectional Reflectance and Transmission for Space Applications

Applications for optical diffusers in space projects are presented which include the functions of reflection, transmittance, and collection. These modes encompass such diverse uses as temperature regulation and ozone concentration monitors. Discussed is the cooperative aspect of diffuse reflectance and environmental stability. Magnesium oxide, sodium chloride and barium sulphate are evaluated in some detail. The importance of scene scattering behavior to modeling the earth’s radiation budget and in determining thermal inertias of the earth’s surface are discussed, because solar albedo serves as the weighting function in the solar input irradiance. Finally, work in the area of canopy reflectance modeling is reviewed with verification data included whenever available. Some knowledge of the bidirectional reflectance properties of vegetation is necessary for identification, acreage computations, and scene transference.     

A directed acyclic graph for pop-up card design

Pop-up cards are an interesting form of paper art with intriguing geometrical properties. Normally, there are two types of pop-up cards. Origami architecture is a 90-degree card and a v-fold pop up is a 180-degree card. Recently, some approaches have been proposed to aid in the design of a pop-up card. Most of the works on pop-up crafting have used a software tool to design pop-up cards. However, a design tool for a 90-degree card cannot be adopted for the design of a 180-degree card. For the same reason, a method for producing a 180-degree card also cannot be applied to a 90-degree card. This paper proposes a directed acyclic graph (DAG) for designing both types of pop-up cards. These two types of pop-up cards could be created with DAG data structure. The DAG algorithm ensures that the pop-up card is foldable, stable, and intersection-free when opened and closed. The proposed method is demonstrated with various paper pop-up cards, and experimental examples are presented.     

三维游戏场景设计中树的制作与应用

树是三维游戏场景中重要的元素之一,因其结构复杂,在游戏场景中还原树的外型较为困难,所以需要用各种方法“蒙蔽”玩家的双眼,以追求更好的视觉效果。文章阐述了三维游戏中树的制作建模过程,分析如何提高优化玩家的视觉感观,体现游戏场景的气氛与环境表现手法的实际运用。     

Quantification of diacylglycerol species from cellular extracts by electrospray ionization mass spectrometry using a linear regression algorithm

Diacylglycerols (DAGs) play significant roles in both intermediate metabolism and signal transduction. These lipid species are second messengers involved in modulating a plethora of cellular processes. Evaluation of DAG species concentrations has been hampered by the lack of a reliable method for molecular species analysis within a complex mixture of cellular lipids. We describe a new method for quantitative analysis of DAG species from complex biological extracts based on positive mode electrospray ionization mass spectrometry without prior derivatization. Quantification is achieved using internal standards and calibration curves constructed by spiking cell extracts with different concentrations of DAG species containing various acyl chain lengths and degrees of unsaturation. The new mass spectral data processing algorithm incorporates a multiple linear regression model including a factor accountable for possible interactions between experimental preparations and the slope of the curve for the standards, allowing the examinations of the effects of sample origin conditions (such as cell types, phenotypes, etc.) and instrument variability on this slope. Internal standards provide a basis for quantification of 28 DAG molecular species detected in RAW 264.7 cells after stimulation of a G-protein coupled receptor with platelet activating factor. This method displays excellent reproducibility over the established range of concentrations with variations of < or =10% and is highly sensitive with a detection limit of 0.1-0.4 pmol/microL depending upon acyl chain composition. We have shown differential effects on various DAGs in response to a ligand which illustrates the importance of examining lipids at the molecular species level rather than as a single homogeneous entity.