基于矢量瓦片的点状要素注记处理技术

矢量瓦片体积小,可高度压缩,受网络带宽开销和存储空间的限制较小。地图瓦片化对桌面软件点注记处理带来挑战,不仅是点注记的处理存在重要注记被次要注记压盖、同级注记之间互相压盖、注记与要素压盖等问题,同时瓦片化也带来了注记被瓦片边缘截断显示不完全的问题,这些问题严重影响了地图的可读性和信息传递功能。本文针对以上问题总结了矢量瓦片点注记处理原则,通过设计矢量瓦片的组织结构,确定注记搭配表的JSON组织形式,明确矢量瓦片点注记的绘制流程,根据矢量瓦片特点使用四叉编码进行目标过滤,使用R树作为高效空间索引,并采用基于注记优先级的避障技术解决上述点注记处理带来的问题。     

基于SVM的墙地砖颜色自动分类

支持向量机(SVM)是一种采用结构风险最小化原则的新的机器学习方法，具有完备的理论基础。该文首次把支持向量机技术应用于墙地砖的自动分类，首先通过对墙地砖图像的RGB通道进行小波分解，由于不同通道的相关性，故提取其协变信号作为特征集，再构建二叉树形式的决策树来实现SVM多类分类，然后对墙地砖进行了颜色分类实验，并与knn分类结果对比，实验结果证明SVM分类器具有更高的分类准确率。     

Coding and geometrical shapes in nanostructures: A fractal DNA-assembly

Fractal patterns represent an important classof aperiodic arrangements. Generating fractalstructures by self-assembly is a majorchallenge for nanotechnology. The specificityof DNA sticky-ended interactions and thewell-behaved structural nature of DNAparallelogram motifs has previously led to aprotocol that appears likely to be capable ofproducing fractal constructions [A. Carbone andN.C. Seeman, A route to fractal DNAassembly, Natural Computing 1,469–480, 2002]. That protocol dependson gluing the set of tiles with special `gluetiles' to produce the fractal structure. It ispossible to develop a fractal-assembly protocolthat does not require the participation ofgluing components. When designed with similarDNA parallelogram motifs, the protocol involvessixteen specific tiles, sixteen closely relatedtiles, and a series of protecting groups thatare designed to be removed by the introductionof specific strands into the solution. Onenovel aspect of the construction on thetheoretical level is the interplay of bothgeometry and coding in tile design. A secondfeature, related to the implementation, is thenotion of generalized protecting groups.     

基于图像的异型墙地砖在线分道系统

提出了一种异型墙地砖在线提取和纹理比较的方法。将CCD采集的墙地砖图像进行灰度阈值分割后,经过以矩形模式为特征的轮廓搜索,对原始图像中的砖面区域做标准化仿射变换处理,实现墙地砖的在线提取。依据计算共生矩阵特征向量,采用最小距离分类原理进行纹理比较分类决策,并采用自适应阈值参数加强算法的鲁棒性。基于所提取算法研制了异型墙地砖在线分道系统,并在实际现场运行成功,取得良好的分道效果。     

Fixed-point tile sets and their applications

An aperiodic tile set was first constructed by R. Berger while proving the undecidability of the domino problem. It turned out that aperiodic tile sets appear in many fields, ranging from logic (the Entscheidungsproblem) to physics (quasicrystals). We present a new construction of an aperiodic tile set that is based on Kleene?s fixed-point construction instead of geometric arguments. This construction is similar to J. von Neumann?s self-reproducing automata; similar ideas were also used by P. Gács in the context of error-correcting computations. This construction is rather flexible, so it can be used in many ways. We show how it can be used to implement substitution rules, to construct strongly aperiodic tile sets (in which any tiling is far from any periodic tiling), to give a new proof for the undecidability of the domino problem and related results, to characterize effectively closed one-dimensional subshifts in terms of two-dimensional subshifts of finite type (an improvement of a result by M. Hochman), to construct a tile set that has only complex tilings, and to construct a “robust” aperiodic tile set that does not have periodic (or close to periodic) tilings even if we allow some (sparse enough) tiling errors. For the latter, we develop a hierarchical classification of points in random sets into islands of different ranks. Finally, we combine and modify our tools to prove our main result: There exists a tile set such that all tilings have high Kolmogorov complexity even if (sparse enough) tiling errors are allowed. Some of these results were included in the DLT extended abstract (Durand et al., 2008 [9]) and in the ICALP extended abstract (Durand et al., 2009 [10]).     

基于DNA Tiles自组装的布尔逻辑运算

大量研究工作表明,DNA tiles自组装现象是分子生物计算过程中一个很重要的计算方式.分子自组装的基本特点在于由许多小分子在一定机理的作用下,自动形成更大规模的超级分子结构的过程.自组装用于计算,在于这种组装模式可以抽象成一个自动化的系统,只需根据问题的需要设计好输入,再将其输入到运算系统,经过分子自组装过程,最后能生成问题的解.文中基于这样的运算机理,在DNA tiles自组装这个计算平台上,尝试做布尔逻辑运算,针对4变量4句子的布尔逻辑问题,提出一个DNA tiles自组装自动化运算系统.     

喷墨印花——建陶印刷技术的一大革新

中国是世界公认的建陶生产大国,建陶产量占全球产量的65％,但由于印花设备和技术的落后,产品仪被定位在中低档水平,同时高能耗、高污染、高排放的现状也困扰着中国建陶业的发展.喷墨印花技术具有能耗低、效率高、印刷的产品质量好等优点,该技术的引进和发展,必将为中国向建陶生产强国迈进提供强有力的技术支持.     

Robust tile-based texture synthesis using artificial immune system

One significant problem in tile-based texture synthesis is the presence of conspicuous seams in the tiles. The reason is that sample patches employed as primary patterns of the tile set may not be well stitched if carelessly picked. In this paper, we introduce a robust approach that can stably generate an ω-tile set of high quality and pattern diversity. First, an extendable rule is introduced to increase the number of sample patches to vary the patterns in an ω-tile set. Second, in contrast to other concurrent techniques that randomly choose sample patches for tile construction, ours uses artificial immune system (AIS) to select the feasible patches from the input example. This operation ensures the quality of the whole tile set. Experimental results verify the high quality and efficiency of the proposed algorithm.     

Search methods for tile sets in patterned DNA self-assembly

The Pattern self-Assembly Tile set Synthesis (PATS) problem, which arises in the theory of structured DNA self-assembly, is to determine a set of coloured tiles that, starting from a bordering seed structure, self-assembles to a given rectangular colour pattern. The task of finding minimum-size tile sets is known to be NP-hard. We explore several complete and incomplete search techniques for finding minimal, or at least small, tile sets and also assess the reliability of the solutions obtained according to the kinetic Tile Assembly Model.     

龙门式瓷砖自动码垛装置

瓷砖的自动包装线的出现解决了降低劳动强度、提高生产效率的问题,为了节省瓷砖仓储所占空间,往往还需要进行人工的整理,本文设计了一种应用于瓷砖包装线上能够进行水平和竖直混合码垛的装置,整体采用PLC控制,通过人机界面设定参数,即可实现多种平竖混合结构的码垛。速度不低于12包/分钟,完全满足当前效率最高的自动包装线。     

Molecular solutions for minimum and exact cover problems in the tile assembly model

The tile assembly model is a novel biological computing model where information is encoded in DNA tiles. It is an efficient way to solve NP-complete problems due to its scalability and parallelism. In this paper, we apply the tile assembly model to solve the minimum and exact set cover problems, which are well-known NP-complete problems. To solve the minimum set cover problem, we design a MinSetCover system composed of three parts, i.e., the seed configuration subsystem, the nondeterministic choice subsystem, and the detection subsystem. Moreover, we improve the MinSetCover system and propose a MinExactSetCover system for solving the problem of exact cover by 3-sets. Finally we analyze the computation complexity and perform a simulation experiment to verify the effectiveness and correctness of the proposed systems.     

A New Genetic Algorithm for Loop Tiling

Tiling is a known problem especially in the field of computational geometry and its related engineering branches. In fact, a tile is a set of points in the Cartesian space. The goal is to partition the space of the points as tiles with optimal dimensions and shapes such that a number of predefined semantic relations holds amongst the tiles. So far, this problem has been solved in special cases with two or three dimensions. The problem of determining the optimal tile is an NP-Hard problem. Presenting a novel constraint genetic algorithm in this paper, we have been able to solve the tiling problem in Cartesian spaces with more than two dimensions, for the loop parallelization problem.     

基于边界特征配准的墙地砖缺陷检测研究

该文结合radon变换和几何推理,研究了基于墙地砖边界的用于规则图案表面缺陷检测的图像配准方法。实验证明该算法简单快捷,能检测出墙地砖的一般常见缺陷。     

Generating Stochastic Wall Patterns On‐the‐fly with Wang Tiles

The game and movie industries always face the challenge of reproducing materials. This problem is tackled by combining illumination models and various textures (painted or procedural patterns). Generating stochastic wall patterns is crucial in the creation of a wide range of backgrounds (castles, temples, ruins…). A specific Wang tile set was introduced previously to tackle this problem, in an iterative fashion. However, long lines may appear as visual artifacts. We use this tile set in a new on‐the‐fly procedure to generate stochastic wall patterns. For this purpose, we introduce specific hash functions implementing a constrained Wang tiling. This technique makes possible the generation of boundless textures while giving control over the maximum line length. The algorithm is simple and easy to implement, and the wall structure we get from the tiles allows to achieve visuals that reproduce all the small details of artist painted walls.     

一种改进的考虑噪声约束的过点分配方法

首先介绍了耦合电容计算、噪声模型选择以及串扰噪声的估计,接着详细分析了一种用于多层无网格区域布线的过点分配算法CPACNC（Crosspoint Assignment with Crosstalk Noise Control）。该算法首先根据障碍物信息将小方块边界分成多个区段,再分两步解CPA问题：CCPA（Coarse Crosspoint Assignment）和DCPA（Detailed Crosspoint Assignment）。针对CPACNC算法在进行边界分解时可能产生许多碎段的缺点,最后提出了一种修正算法,以处理边界分解时产生许多碎段的情况,使CPACNC方法更加有效。     

基于直方图聚类的颜色分级方法

文章提出了一种利用颜色特征对瓷砖进行在线颜色分级的新方法。针对瓷砖图像数据量大的特点,采用了颜色空间分裂和与初始条件无关的聚类算法相结合的量化方法来提取瓷砖图像颜色特征,这既可满足算法实时性要求又充分考虑到了颜色分级对特征的精确性要求。实验结果证明了该方法的有效性。     

基于联锁分块的大规模地形建模方法研究

针对已有MRLoD算法生成的地形=三角形网不稳定等缺点,提出了一种新的基于联锁分块的大规模地形建模方法,在对地形进行分块调度的基础上通过预先建立分块模板和分块联锁模板,渲染时动态匹配各模板建立平滑完整的分块模型,在分块调度及附加计算策略下,拼接各分块以完成整块地形的多分辨率建模,并以高效的方式将模型数据传人渲染硬件.实验表明,在满足了精度要求的同时提高了模型的稳定性,有效减少了实时计算量,在渲染效率上取得了令人满意的结果,能够满足用户对大规模地形的实时漫游的要求.     

Dual Poisson-Disk Tiling: an efficient method for distributing features on arbitrary surfaces

This paper introduces a novel surface-modeling method to stochastically distribute features on arbitrary topological surfaces. The generated distribution of features follows the Poisson disk distribution, so we can have a minimum separation guarantee between features and avoid feature overlap. With the proposed method, we not only can interactively adjust and edit features with the help of the proposed Poisson disk map, but can also efficiently re-distribute features on object surfaces. The underlying mechanism is our dual tiling scheme, known as the Dual Poisson-Disk Tiling. First, we compute the dual of a given surface parameterization, and tile the dual surface by our specially-designed dual tiles; during the pre-processing, the Poisson disk distribution has been pre-generated on these tiles. By dual tiling, we can nicely avoid the problem of corner heterogeneity when tiling arbitrary parameterized surfaces, and can also reduce the tile set complexity. Furthermore, the dual tiling scheme is non-periodic, and we can also maintain a manageable tile set. To demonstrate the applicability of this technique, we explore a number of surface-modeling applications: pattern and shape distribution, bump-mapping, illustrative rendering, mold simulation, the modeling of separable features in texture and BTF, and the distribution of geometric textures in shell space.     

Reducing Tile Complexity for the Self-assembly of Scaled Shapes Through Temperature Programming

This paper concerns the self-assembly of scaled-up versions of arbitrary finite shapes. We work in the multiple temperature model that was introduced by Aggarwal, Cheng, Goldwasser, Kao, and Schweller (Complexities for Generalized Models of Self-Assembly, SIAM J. Comput. 2005). The multiple temperature model is a natural generalization of Winfree’s abstract tile assembly model, where the temperature of a tile system is allowed to be shifted up and down as self-assembly proceeds. We first exhibit two constant-size tile sets in which scaled-up versions of arbitrary shapes self-assemble. Our first tile set has the property that each scaled shape self-assembles via an asymptotically “Kolmogorov-optimum” temperature sequence but the scaling factor grows with the size of the shape being assembled. In contrast, our second tile set assembles each scaled shape via a temperature sequence whose length is proportional to the number of points in the shape but the scaling factor is a constant independent of the shape being assembled. We then show that there is no constant-size tile set that can uniquely assemble an arbitrary (non-scaled, connected) shape in the multiple temperature model, i.e., the scaling is necessary for self-assembly. This answers an open question of Kao and Schweller (Proceedings of the 17th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2006), pp. 571–580, 2006), who asked whether such a tile set exists.     

Set Packing问题的研究进展

Set Packing问题起源于分割问题的应用，是在强约束条件对元素进行划分。在复杂性理论中，此问题是一类重要的NP难问题，被广泛应用于调度、代码优化和生物信息学等领域。特别是在参数计算理论产生后，此问题再次成为研究的热点问题。依据所研究问题的差异，本文将Set Packing问题分成5类，并给出了具体的定义。在此基础上，分别介绍了求解这5类问题的相关算法，着重分析和比较了参数算法中所运用的各项技术，并提出了该问题算法研究的一些发展方向。