自组织中文语义映射网络的优化特征编码方法

本文介绍自组织中文语义映射网络,并分别基于集合论、代数理论和概率论研究和提出六种不同的特征编码方法,这对自组织语义映射效果有很重要的影响。通过性能评价得出如下结论:使用TFIDF修正的频率密度编码能得到最佳效果,其语义映射的精确度和召回率分别为94.4%和90.7% ,而基于向量模型的方法则都不适用于中文自组织语义映射。文中给出结果分析。另外比较实验结果表明文中的最好方法其系统性能好于目前广泛采用的分层聚类技术,并远好于多元统计分析技术,例如主成分分析的特征降维编码。     

Antialiasing of Environment Maps

Environment maps, like texture maps or any other maps consisting of discretely stored data have to be properly filtered, if they are being resampled in the process of rendering an image. For environment maps, this is especially important, as the sampling rate is subject to extreme changes due to the curvature of the reflecting surfaces. However, for the same reason, the antialiasing is especially difficult to perform, as the sampling rate has to be determined for each pixel. We introduce a method to perform this calculation and determine the parameters for anisotropic filtering of the environment map. Instead of the BRDF, we employ roughness pyramids to account for the properties of the reflecting surface. The principles that are used to perform this antialiasing can be applied for antialiasing reflected textures in general e.g. in ray tracing.     

NEnv: Neural Environment Maps for Global Illumination

Environment maps are commonly used to represent and compute far-field illumination in virtual scenes. However, they are expensive to evaluate and sample from, limiting their applicability to real-time rendering. Previous methods have focused on compression through spherical-domain approximations, or on learning priors for natural, day-light illumination. These hinder both accuracy and generality, and do not provide the probability information required for importance-sampling Monte Carlo integration. We propose NEnv, a deep-learning fully-differentiable method, capable of compressing and learning to sample from a single environment map. NEnv is composed of two different neural networks: A normalizing flow, able to map samples from uniform distributions to the probability density of the illumination, also providing their corresponding probabilities; and an implicit neural representation which compresses the environment map into an efficient differentiable function. The computation time of environment samples with NEnv is two orders of magnitude less than with traditional methods. NEnv makes no assumptions regarding the content (i.e. natural illumination), thus achieving higher generality than previous learning-based approaches. We share our implementation and a diverse dataset of trained neural environment maps, which can be easily integrated into existing rendering engines.     

Analytic Tangent Irradiance Environment Maps for Anisotropic Surfaces

Environment‐mapped rendering of Lambertian isotropic surfaces is common, and a popular technique is to use a quadratic spherical harmonic expansion. This compact irradiance map representation is widely adopted in interactive applications like video games. However, many materials are anisotropic, and shading is determined by the local tangent direction, rather than the surface normal. Even for visualization and illustration, it is increasingly common to define a tangent vector field, and use anisotropic shading. In this paper, we extend spherical harmonic irradiance maps to anisotropic surfaces, replacing Lambertian reflectance with the diffuse term of the popular Kajiya‐Kay model. We show that there is a direct analogy, with the surface normal replaced by the tangent. Our main contribution is an analytic formula for the diffuse Kajiya‐Kay BRDF in terms of spherical harmonics; this derivation is more complicated than for the standard diffuse lobe. We show that the terms decay even more rapidly than for Lambertian reflectance, going as l^–3, where l is the spherical harmonic order, and with only 6 terms (l = 0 and l = 2) capturing 99.8% of the energy. Existing code for irradiance environment maps can be trivially adapted for real‐time rendering with tangent irradiance maps. We also demonstrate an application to offline rendering of the diffuse component of fibers, using our formula as a control variate for Monte Carlo sampling.     

基于图形硬件的辐照度环境纹理图的计算方法

辐照度环境纹理图是绘制任意光照环境下漫反射物体表面的一种有效的方法。为了实现动态光照环境下辐照度环境纹理图的实时绘制,基于当前的通用图形硬件,提出了一种采用顶点着色器快速计算辐照度环境纹理图的方法。该方法从分析球面调和函数入手,首先得出环境贴图的二次多项式表达形式;然后用顶点着色程序对多项式系数和球面调和函数进行加速计算,以快速生成辐照度环境纹理图;最后对于动态光照环境,则通过对环境纹理图的分级细化来加快光照系数的计算,进而实现了动态光照环境下辐照度环境纹理图的重新绘制。实验表明,在动态光照条件下,采用该方法在获取真实感光照效果的同时,其运算速度也能满足交互系统的需求。     

GIS环境下制图自动综合

借助GIS的可视化以及GIS的空间分析工具,制图自动综合的研究进入了一个新阶段;一方面,GIS扩大了制图自动综合的内涵,另一方面,制图自动综合推动了GIS的发展;丰富了GIS的研究内容。实际上,制图自动综合应该是GSI系统的重要组成部分或应具有的重要功能。制图自动综合的研究手段和研究方法越来越丰富并取得了很大进展;在总结前人研究的基础上提出了GIS分层支持下的面向地理特征的自动综合,实验表明这种方法是可行的,但仍然存在诸多问题,这种方法的完善必须走基于知识综合的道路。     

EnvyDepth: An Interface for Recovering Local Natural Illumination from Environment Maps

In this paper, we present EnvyDepth, an interface for recovering local illumination from a single HDR environment map. In EnvyDepth, the user quickly indicates strokes to mark regions of the environment map that should be grouped together in a single geometric primitive. From these annotated strokes, EnvyDepth uses edit propagation to create a detailed collection of virtual point lights that reproduce both the local and the distant lighting effects in the original scene. When compared to the sole use of the distant illumination, the added spatial information better reproduces a variety of local effects such as shadows, highlights and caustics. Without the effort needed to create precise scene reconstructions, EnvyDepth annotations take only tens of seconds to produce a plausible lighting without visible artifacts. This is easy to obtain even in the case of complex scenes, both indoors and outdoors. The generated lighting environments work well in a production pipeline since they are efficient to use and able to produce accurate renderings.     

优化企业环境 提升管理效率

<正>近期富士施乐宣布在亚太区推出端到端的企业文件管理外包服务——企业打印管理服务。该服务通过富士施乐服务全球的主机系统对企业的办公打印、文印中心和远程/移动打印进行全面的统一管理,旨在帮助企业更好的管理文件,提高工作效率。富士施乐此次推出的最新企业打印管理服务在原有办公管理服务的基础上,扩充了远程和移动打印服务、企业文     

Stackmaker: An Environment for Creating Hypermedia Learning Material

Hypermedia has for some time now been proposed as an adjunct to printed material within the educational process. However, creating a highly interconnected hypermedia network is complex and time consuming, with overviews of the content and structure of the information seemingly essential in order to avoid the disorientation and cognitive overload problems often described.

This paper describes an environment designed to remove much of the burden of creating such support facilities, allowing the teacher to concentrate on the content and structure of the information presented.     

强实时环境下调度非周期任务的时限寻优方法

文章提出了强实时环境下调度弱时限非周期任务的时限寻优方法（ＤＯＡ）,该方法在保证周期任务和偶发性任务满足时限要求的前提下,使非周期任务的响应时间达到最优。它还可根据实时应用的需要对算法的执行性能和计算复杂度进行折衷调整。仿真实验表明,ＤＯＡ与现有的动态调度算法相比,使非周期任务响应时间更短,同时它收敛快,额外开销小,计算复杂度低,实现方便,因此是强实时环境下对周期任务与非周期任务进行混合调度的一种较好的方法。     

动态灾害环境下多对多物资配送路径规划方法

动态灾害环境下多对多物资配送路径规划问题具有重大的现实意义,它需要在路径规划的同时应对路网环境随时间的变化,并找到不同应急物资储备点、配送点之间的最佳对应关系,同时保证求解的时效性和成功率.目前的静态预案规划方法(SPO)和动态路径规划方法(DPO)难以确保动态灾害环境下求解效果的理论最优性,甚至可能导致部分配送点不能...     

Guest Editors' Introduction: Smart Depiction for Visual Communication

As computers become faster, smaller, ubiquitous, and interconnected, the rate at which we generate new data is growing exponentially. Sophisticated computational simulation techniques have made it fast and easy to create large volumes of data by modeling all kinds of physical phenomena. Meanwhile, digital sensors and sensor networks have simplified the process of collecting data from the real world. Moreover, the Internet has connected us to one another in a way that further facilitates creation and dissemination of information. In fact, Lyman and Varian estimate that new stored information grew at a rate of 30 percent a year from 1999 to 2002 and that we produced 5 exabytes (equivalent to about 37,000 new libraries the size of the Library of Congress) of completely new information in the year 2002 alone.     

访问控制策略描述和应用

访问控制是重要的信息系统安全机制。在日趋复杂的应用中有效利用访问控制成为一个难题。该文提出了一种访问控制描述方法和服务域的概念。这种方法以服务域作为访问控制策略的组织单元,简化访问控制的管理和使用。     

Bias Compensation for Photon Maps

Density estimation techniques such as the photon map method rely on a particle transport simulation to reconstruct indirect illumination, which is proportional to the particle density. In the photon map framework, particles are usually located using nearest‐neighbour methods due to their generality. However, these methods have an inherent tradeoff between local bias and noise in the reconstructed illumination, which depends on the density estimate bandwidth. This paper presents a bias compensating operator for nearest‐neighbour density estimation which adapts the bandwidth according to the estimated bias in the reconstructed illumination. ACM CSS: I.3.7 Three‐Dimensional Graphics and Realism Raytracing     

Cognitive Maps for Planetary Rovers

This essay explores the problem of providing both autonomy and safety for a planetary rover too far away for continuous teleoperated control. Evidence from animal and human spatial behavior suggests useful characteristics for the sensory system and cognitive map of a planetary rover. I then sketch a design for a mixed-initiative exploration strategy for a semi-intelligent rover with a remote human operator, and describe some questions to be resolved by further research.     

汉字的笔段网格字形描述及字形比对算法

由于目前计算机缺乏对汉字字形统一有效的形式化描述和比对计算方法,致使无法描画输入所需的各种可能汉字,也无法利用计箅机对字形进行比对分析.提出一种具有颗粒度适当、无歧义、规范化基元,能描述各种可能字形(包括错字、古籍异体字、拼合字)骨架异同的笔段网格汉字字形描述方法;并基于该方法给出了字形比对算法,它能自动提取字形包含的简单笔画和复合笔画,根据字形的不同自适应地选取复合笔画或简单笔画,并以此为单位进行比对;最后将计算两字形最优配对笔画间的向量距离总和作为比对结果.实验结果表明,该方法具有很强的字形描述能力,字形比对算法对结构规范字形的比对准确牢较高,可用于支持各种汉字的描画输入及面向字形比对分析的各种应用.     

Neuromorphic Excitable Maps for Visual Processing

An excitable membrane is described which can perform different visual tasks such as contour detection, contour propagation, image segmentation, and motion detection. The membrane is designed to fit into a neuromorphic multichip system. It consists of a single two-dimensional (2-D) layer of locally connected integrate-and-fire neurons and propagates input in the subthreshold and the above-threshold range. It requires adjustment of only one parameter to switch between the visual tasks. The performance of two spiking membranes of different connectivity is compared, a hexagonally and an octagonally connected membrane. Their hardware and system suitability is discussed     

Fuzzy Cognitive Maps for stereovision matching

This paper outlines a method for solving the stereovision matching problem using edge segments as the primitives. In stereovision matching the following constraints are commonly used: epipolar, similarity, smoothness, ordering and uniqueness. We propose a new matching strategy under a fuzzy context in which such constraints are mapped. The fuzzy context integrates both Fuzzy Clustering and Fuzzy Cognitive Maps. With such purpose a network of concepts (nodes) is designed, each concept represents a pair of primitives to be matched. Each concept has associated a fuzzy value which determines the degree of the correspondence. The goal is to achieve high performance in terms of correct matches. The main findings of this paper are reflected in the use of the fuzzy context that allows building the network of concepts where the matching constraints are mapped. Initially, each concept value is loaded via the Fuzzy Clustering and then updated by the Fuzzy Cognitive Maps framework. This updating is achieved through the influence of the remainder neighboring concepts until a good global matching solution is achieved. Under this fuzzy approach we gain quantitative and qualitative matching correspondences. This method works as a relaxation matching approach and its performance is illustrated by comparative analysis against some existing global matching methods.     

Optimizing Real-Time Performance of 3D Virtual Mining Environment with MultiGen Creator

System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a virtual mining system were discussed: optimizing 3D models to keep the polygon number in VR system within target hardware's processing ability; optimizing texture database to save texture memory with perfect visual effect; optimizing database hierarchy structure to accelerate model retrieval; and optimizing LOD hierarchy structure to speed up rendering.