基于激光雷达距离图像的道路边缘检测与跟踪

论述了将激光雷达的距离图像信息用于道路检测和跟踪。首先将扫描点进行聚类分析对道路边缘进行检测和对所检测的边缘进行最小二乘直线拟合,在成功检测道路边缘后,利用Kalman滤波对道路边缘进行跟踪。实验证明该算法具有检测准确且鲁棒性好的特点。     

Lower Bound on the Minimum Number of Edges in Subgraphs of Johnson Graphs

Problems of Information Transmission - We prove a new lower bound on the minimum number of edges in subgraphs of Johnson graphs in the general case.     

On the Number of t-Ary Trees with a Given Path Length

We show that the number of t-ary trees with path length equal to p is $\exp({{(\alpha {p}/{\log p})}(1+o(1))}),$ where $\alpha=h(t^{-1})t\log t$ and $h(x)={-}x\log x {-}(1{-}x)\log (1{-}x).$ Besides its intrinsic combinatorial interest, the question recently arose in the context of information theory, where the number of t-ary trees with path length p estimates the number of universal types, or, equivalently, the number of different possible Lempel-Ziv '78 dictionaries for sequences of length p over an alphabet of size t.     

C语言中浮点数的表示范围浅析

浮点数是C语言中的一种数据类型,但在标准C中并没有给出其具体的描述,即数的存储格式及表示范围。部分经典的C语言程序设计教程中给出了浮点数的表示范围,但存在不严谨和值得商榷的地方。结合IEEE754标准,就C语言中浮点数内在存储格式进行分析并给出结论。     

On a Hopfield Net Arising in the Modelling and Control of Over-Saturated Signalized Intersections

We present a neural method – based on the Hopfield net – for the modelling and control of over-saturated signalized intersections. The problem is to look, in real-time, for lights signal setting which minimize a given traffic criterion such as waiting time. The use of the Hopfield model is straightforward justified by its optimization capabilities, especially its fast time computing (by its own dynamic), which is of a great interest in real-time problems like the traffic control one. The original Hopfield algorithm is modified to take into account proper constraints of the traffic problem. This approach is illustrated by numerical examples of traffic conditions generated by a simulator. We extend the method to urban nets of several interconnected intersections.     

On the Precision in Estimating the Location of Edges and Corners

Recently, in Rohr [13], we analyzed the systematiclocalization errors introduced by local operators for detectinggrey-value corners. These errors are inherently due to thedifferential structure of the operators and, in general, areenlarged by discretization and noise effects. Here, we take thestatistical point of view to analyze the localization errorscaused by noisy data. We consider a continuous image model thatrepresents the blur as well as noise introduced by an imagingsystem. In general, the systematic intensity variations arenonlinear functions of the location parameters. For this modelwe derive analytic results stating lower bounds for the locationuncertainty of image features. The lower bounds are evaluatedfor explicit edge and corner models. We show that the precisionof localization in general depends on the noise level, on thesize of the observation window, on the width of the intensitytransitions, as well as on other parameters describing thesystematic intensity variations. We also point out that theuncertainty lower bounds in localizing these image features canin principle be attained by fitting parametric models directlyto the image intensities. To give an impression of theachievable accuracy numerical examples are presented.     

On the Decision Table with Maximal Number of Reducts

Searching for reducts is a basic problem for many rough set methods like rule induction, classification, etc., Many of them can not be realized in exact way because of existing possibly exponential number of (relative) reducts in decision tables. In this paper we investigate properties of the most malicious decision tables, i.e., tables with maximal number of reducts. We show that in such systems, the number of objects must be also exponential. The presented method is based on Boolean reasoning approach.     

基于竞争终端个数区间的IEEE 802.11性能优化

IEEE 802.11的MAC协议采用基于CSMA/CA的DCF机制,研究发现,上述协议的性能随无线局域网中竞争终端个数的增加而迅速恶化.当竞争终端个数在一定范围内变化时,使用相同的优化协议参数,系统的性能都能接近最优.因此,设计了一个基于状态检测与竞争终端个数区间的自适应性能优化机制,DOOR(dynamicootimization on range).根据相关性能模型的分析,先将竞争终端的个数分为若干区间,并分别计算出各区间的优化协议参数.当系统检测到竞争终端个数发生变化时,根据其所处的区间,对相关的参数进行动态调整,从而有效地改善了协议的整体性能.同时还给出了相关理论模型和计算的详细说明,并尝试给出了划分区间的基本原则与方法.最后,实验仿真结果验证了新的方法能够根据竞争终端个数的变化对系统性能进行整体优化,在吞吐量和延迟等方面明显优于标准的IEEE 802.11协议.     

On the Number of Digital Discs

A digital disc is defined as the set of all integer points inside of a given real disc. In this paper we show that there are no more than

基于门诊号源的均匀分布算法的设计与研究

文章主要为了解决在已设置好的基础号源中均匀地设置给定数量的"网上开放"号源,从而达到网上限号的目的.解决方法:假设基础号源数为M,需要设置的"网上开放"号源数为N,将N与M进行约分,得到最小分子(FZ)和分母(FM),然后将基础号源数M分成多个FM,然后在每个FM中取FZ个号源设置成"网上开放"号源.这种方法的好处是让...     

On Stability of the Independence Number of a Certain Distance Graph

Problems of Information Transmission - We study the asymptotic behavior of the independence number of a random subgraph of a certain (r, s)-distance graph. We provide upper and lower...     

Hypergraph recovery algorithms from a given vector of vertex degrees

Methods of obtaining certain classes of hypergraphs from a given integer vector of vertex degrees are considered. These classes are as follows: hyperedges with unit weight incident upon k vertices; hyperedges with unit weight incident upon k vertices in the case when the vertices may be non-unique; multiple hyperedges incident upon k vertices; and arbitrary hypergraph in which the edges can contain any set of k vertices. For each of these classes, an algorithm is proposed for constructing the hypergraph from an arbitrary vector. If the construction is impossible, the algorithm determines how much the vector should be reduced so that the hypergraph could be constructed.     

Simulation of Tearing Cloth with Frayed Edges

Woven cloth can commonly be seen in daily life and also in animation. Unless prevented in some way, woven cloth usually frays at the edges. However, in computer graphics, woven cloth is typically modeled as a continuum sheet, which is not suitable for representing frays. This paper proposes a model that allows yarn movement and slippage during cloth tearing. Drawing upon techniques from textile and mechanical engineering fields, we model cloth as woven yarn crossings where each yarn can be independently torn when the strain limit is reached. To make the model practical for graphics applications, we simulate only tearing part of cloth with a yarn‐level model using a simple constrained mass‐spring system for computational efficiency. We designed conditions for switching from a standard continuum sheet model to our yarn‐level model, so that frays can be initiated and propagated along the torn lines. Results show that our method can achieve plausible tearing cloth animation with frayed edges.     

On the Possibility of Designing Fully Uniform Control Systems

For a new class of fully uniform neural computers (processing fields) exhibiting characteristics that approach those of the controlling and regulating centers of biological subjects, some physical fundamentals were considered, and principles of design proposed.     

On Embedding a Graph in the Grid with the Maximum Number of Bends and Other Bad Features

Graph Drawing is (usually) concerned with the production of readable representations of graphs. In this paper, instead of investigating how to produce “good” drawings we tackle the opposite problem of producing “bad” drawings. In particular, we study how to construct orthogonal drawings with many bends along the edges and with large area. Our results show surprising contact points, in Graph Drawing, between the computational cost of niceness and the one of ugliness.     

浅谈数字色彩与设计

在现代设计活动中,数字技术已经渐渐渗入到人们生活中的每一部分。利用数码相机采集数字图片,利用数字软件处理图形、设计,利用数字技术展开虚拟实物设计等,也成为了辅助设计手段的重要组成部分,但是人们必须要撑握了解这些数字工具的算法．实现人们发现这个世界,发现美的目的,并学会用这些工具来虚拟这些美,就像是一个人发现一幅图片的色彩空间太窄,然后在ps里同时按下ctrl＋alt＋1一样,这里就来和读者一起谈谈数字色彩和设计这个话题,记住这是一个话题而不是拆开的两部分。     

浅谈数字色彩与设计

在现代设计活动中,数字技术已经渐渐渗入到人们生活中的每一部分。利用数码相机采集数字图片,利用数字软件处理图形、设计,利用数字技术展开虚拟实物设计等,也成为了辅助设计手段的重要组成部分,但是人们必须要撑握了解这些数字工具的算法,实现人们发现这个世界,发现美的目的,并学会用这些工具来虚拟这些美,就像是一个人发现一幅图片的色彩空间太窄,然后在ps里同时按下ctrl+alt+l一样,这里就来和读者一起谈谈数字色彩和设计这个话题,记住这是一个话题而不是拆开的两部分。     

On the Crossing Number of Complete Graphs

Let (G) denote the rectilinear crossing number of a graph G. We determine (K₁₁)=102 and (K₁₂)=153. Despite the remarkable hunt for crossing numbers of the complete graph K_n – initiated by R. Guy in the 1960s – these quantities have been unknown forn>10 to date. Our solution mainly relies on a tailor-made method for enumerating all inequivalent sets of points (order types) of size 11. Based on these findings, we establish a new upper bound on (K_n) for general n. The bound stems from a novel construction of drawings of K_n with few crossings.