σ-Automata and Chebyshev-polynomials

A σ-automaton is an additive, binary cellular automaton on a graph. For product graphs such as a grids and cylinders, reversibility and periodicity properties of the corresponding σ-automaton can be expressed in terms of a binary version of Chebyshev polynomials. We will give a detailed analysis of the divisibility properties of these polynomials and apply our results to the study of σ-automata.     

具有三维图形描述功能的页面描述语言(PostScript-3D)

页面描述语言是一种新型的程序设计语言,具有很强的图形描述功能。PostScript-3D是对PostScript语言的三维扩充,它支持三维观察变换、裁剪、3D路径、隐藏线和隐藏面消除、三维线框图和具有浓淡效应的真实感图形。本文对PostScript-3D的实现技术进行讨论,并把它与GKS-3D进行比较。     

Robust 3-D-3-D pose estimation

The correspondence focuses on the robust 3-D-3-D pose estimation, especially, multiple pose estimation. The robust 3-D-3-D multiple pose estimation problem is formulated as a series of general regressions which involve a successively size-decreasing data set, with each regression relating to one particular pose of interest. Since the first few regressions may carry a severely contaminated Gaussian error noise model, the MF-estimator (Zhuang et al., 1992) is used to solve each regression for each pose of interest. Extensive computer experiments with both real imagery and simulated data are conducted and results are promising. Three distinctive features of the MF-estimator are theoretically discussed and experimentally demonstrated: It is highly robust in the sense that it is not much affected by a possible large portion of outliers or incorrect matches as long as the minimum number of inliers necessary to give a unique solution are provided; It is made virtually independent of initial guesses; It is computationally reasonable and admits an efficient parallel implementation     

WO3基臭氧敏感元件的研制

在三氧化钨粉体材料中加入金属氧化物,以恒温600℃烧结1小时制成傍热式厚膜O3气体敏感元件.采用静态电压测量法,研究了加入一定质量分数的Nb2O5、Fe2O3、Co3O4、TiO2、Sb2O3后元件的加热电压与电导率、元件灵敏度、60 s后回复几率的关系,讨论了掺杂成分和杂质的质量分数对材料的气敏性能和环境适应能力的影响.实验结果显示:2%TiO2- 3% Nb2O5-WO3元件能开发成理想的O3敏感元件.     

3D sparse signal recovery via 3D orthogonal matching pursuit

Though many three-dimensional (3D) compressive sensing schemes have been proposed, recovery algorithms in most of these schemes are designed for 1D or 2D signals, which cause some serious drawbacks, e.g., huge memory usage, and high decoder complexity. This paper proposes a 3D separable operator (3DSO) which is able to completely exploit the spatial and spectral correlation to sparsify and samples the 3D signal in three dimensions. A 3D orthogonal matching pursuit (3D-OMP) algorithm is then employed to recover the 3D sparse signal, which is able to reduce the computational complexity of the decoder significantly with guaranteed accuracy. In the proposed algorithm, we represent each 3D signal as a weighted sum of 3D atoms, which allow us to sample the 3D signal with 3D separable sensing operator. Then the best matched atoms are selected to construct the 3D support set, and the 3D signal is optimally recovered from the 3D support set in the sense of the least squares. Experimental results show that the 3D-OMP approach achieves higher recovery quality but requires less computational time than the Kronecker Compressive Sensing (KCS) scheme.     

Windows3.xx下三维界面的实现

本文介绍两种在Ｗｉｎｄｏｗｓ３．ｘｘ系统下实现三维界面的方法，分别利用已有的动态连接库和ＶＢＸ控件，并且特别针对前一种方法提供了对应于不同开发环境的实现源代码以供参考     

Java3D技术在三维服装设计中的应用

随着服装工业的发展,三维服装CAD技术得到广泛的应用,通过三维人体测量建立人体三维数据模型,在虚拟的三维人体上进行交互式立体设计,最后完成二维平面服装衣片。大大提高了服装工业产品设计的水平和生产的效率。本文叙述了利用强大的Java3D技术进行三维显示和设计的基本原理和方法。     

利用Sandy引擎实现Flash三维动画

Sandy引擎是目前世界上最优秀的Flash三维引擎之一。利用Sandy引擎,开发人员可以轻松地创建出绚丽的Flash三维动画效果,并实现与用户的交互。该文在详细地介绍了Sandy引擎的基础上,通过具体的实例,深入浅出地介绍了利用Sandy引擎实现Flash三维动画的原理及相关的编程技巧。     

3DCOMET: 3D compression methods test dataset

The use of 3D data in mobile robotics applications provides valuable information about the robot’s environment. However usually the huge amount of 3D information is difficult to manage due to the fact that the robot storage system and computing capabilities are insufficient. Therefore, a data compression method is necessary to store and process this information while preserving as much information as possible.A few methods have been proposed to compress 3D information. Nevertheless, there does not exist a consistent public benchmark for comparing the results (compression level, distance reconstructed error, etc.) obtained with different methods. In this paper, we propose a dataset composed of a set of 3D point clouds with different structure and texture variability to evaluate the results obtained from 3D data compression methods. We also provide useful tools for comparing compression methods, using as a baseline the results obtained by existing relevant compression methods.     

3D textured model encryption via 3D Lu chaotic mapping

In the emerging Virtual/Augmented Reality (VR/AR) era, three dimensional (3D) content will be popularized just as images and videos today. The security and privacy of these 3D contents should be taken into consideration. 3D contents contain surface models and solid models. Surface models include point clouds, meshes and textured models. Previous work mainly focused on the encryption of solid models, point clouds and meshes. This work focuses on the most complicated 3D textured model. We propose a 3D Lu chaotic mapping based encryption method for 3D textured models. We encrypt the vertices, polygons, and textures of 3D models separately using the 3D Lu chaotic mapping. Then the encrypted vertices, polygons and textures are composited together to form the final encrypted 3D textured model. The experimental results reveal that our method can encrypt and decrypt 3D textured models correctly. Furthermore, typical statistic and brute-force attacks can be resisted by the proposed method.     

ST-Rec3D：基于结构和目标感知的三维重建

基于视图的三维重建旨在从二维图像恢复出其对应的三维形状。现有方法主要通过编码器-解码器结构,结合二元交叉熵函数及其变形,完成三维重建,取得较好的重建结果。然而,编码器在编码过程中缺乏对输入视图的结构感知能力,造成重建的三维模型几何细节不准确;以二元交叉熵函数为主的损失函数在体素分布不均衡的情况下,目标感知能力较差,导致其重建结果存在断裂、缺失等不完整性问题。针对此类问题,提出了一种具有结构和目标感知能力的三维重建网络(ST-Rec3D),以单视图或多视图为输入,由粗到细地重建出三维模型;结合注意力机制提出了一种具有空间结构感知能力的编码器,即结构编码器,以充分捕捉输入视图中的空间结构信息,有效感知重建物体的几何细节;将IoU损失引入到三维体素模型重建中,在体素分布不均衡的情况下,精准感知目标物体,确保重建物体的完整性和准确性。在ShapeNet和Pix3D数据集上的对比结果表明,ST-Rec3D在单视图和多视图上重建的三维模型的完整性和准确性均优于当前方法。     

利用Sandy引擎实现Flash三维动画

Sandy引擎是目前世界上最优秀的Flash三维引擎之一。利用Sandy引擎,开发人员可以轻松地创建出绚丽的Flash三维动画效果,并实现与用户的交互。该文在详细地介绍了Sandy引擎的基础上,通过具体的实例,深入浅出地介绍了利用Sandy引擎实现Flash三维动画的原理及相关的编程技巧。     

PHP读取MP3文件ID3标签信息

该文介绍了MP3文件及ID3标签基本结构以及基于PHP语言对MP3文件ID3标签信息的读取的几种方法。     

3-Draw: a tool for designing 3D shapes

A fundamentally new type of CAD system for designing shape that is intuitive, easy to use, and powerful is presented. It is based on a paradigm that can be described as designing directly in 3-D. By virtue of two hand-held sensors, designers using 3-Draw to sketch their ideas in the air feel as if they're actually holding and working on objects. Current design practice and related work are reviewed, and current work on 3-Draw is summarized. To capture the flavor of 3-Draw, construction of a sample model of a 12-m yacht is described. 3-Draw's features and data structures are discussed     

3ds Max制作3D交互原型的应用

使用3ds Max制作3D交互原型具有其独特优势,相比2D类软件来说,它能更准确呈现3D交互的特性,更容易与最终产品匹配;同时相比编程软件来说,它花费的时间少、操作灵活、修改方便。本文通过比较和实践应用的方法说明了3ds Max制作3D交互原型的合理性,并介绍了其应用的过程和方法。     

Thermodynamic assessment of the ternary AgNO3-LiNO3-NaNO3 system

Based on the available experimental information, the AgNO₃-LiNO₃-NaNO₃ ternary system and its low order AgNO₃-LiNO₃, AgNO₃-NaNO₃ and LiNO₃-NaNO₃ binary systems are thermodynamically assessed using the Calphad method. A set of parameters describing the Gibbs energies of the different phases is presented. Ternary parameters are necessary to describe the liquid phase in a neutral species model where each nitrate is treated as a constituent. Calculated phase diagrams and thermodynamical functions for the three limiting binary systems show good agreement with experimental data. In the ternary AgNO₃-LiNO₃-NaNO₃ system we have calculated two vertical sections which are in reasonable agreement with the reported experimental data. Also, several isothermal sections are calculated.     

3D-FUTURE: 3D Furniture Shape with TextURE

International Journal of Computer Vision - The 3D CAD shapes in current 3D benchmarks are mostly collected from online model repositories. Thus, they typically have insufficient geometric details...