Relationship between motor vehicle emissions of hazardous pollutants,roadway proximity,and ambient concentrations in Portland,Oregon

Previous methodologies for modeling hazardous air pollutant emissions for onroad mobile sources are based on using spatial surrogates to allocate county level emissions to grid cells. A disadvantage of this process is that it spreads onroad emissions throughout a grid cell instead of along actual road locations. Recent air quality modeling in Portland, Oregon, using the CALPUFF dispersion model assigned emissions to specific roadway links. The resulting data were used to develop a regression model to approximate the CALPUFF predicted concentrations, determine the impacts of roadway proximity on ambient concentrations of three hazardous air pollutants, benzene, 1,3-butadiene, and diesel PM, and to estimate the zone of influence around roadways.Independent variables in the model included emission rates and traffic volumes for individual roadway links, distance and direction between roadway links and receptors, and distributions of wind speeds and directions. Dependent variables were derived from simulated annual average pollutant concentrations from motor vehicles at modeled receptor locations, predicted using CALPUFF. The regression model had limited capability to predict CALPUFF concentrations with an R-squared value of about 0.6. The model indicated the zone of influence around a roadway as between 200 and 400 m. The results support the thesis that in order to capture localized impacts of hazardous air pollutants in a dispersion model, there is a need to include individual roadway links.     

The Query Language to XML Documents Connected by XLink Links

The XML linking language (XLink) is a language for describing links between resources by means of XML attributes and a special namespace. The specification of the XLink language developed by the World Wide Web consortium provides only data structures for describing links and a minimal model of their behavior. In this paper, a language that allows the application to transparently formulate queries to XLink links and traverse the arcs determined by these links is suggested. The suggested language was named XPathLink, since it was developed as a natural extension of XPath, the language for addressing structural parts of XML documents. The XPathLink encapsulates complexities of XLink syntax from the application and provides a higher abstraction level when processing a set of XML documents connected by XLink links compared to the existing approaches. An implementation of the suggested XPathLink language by functional methods is considered. The functionality of the query language to XML documents connected by XLink links is achieved owing to the integration of the suggested implementation with the general-purpose programming language Scheme at the level of nodes of the processed XML documents and Scheme functions.__________Translated from Programmirovanie, Vol. 31, No. 3, 2005.Original Russian Text Copyright © 2005 by Lizorkin.     

Reinventing Academic Publishing, Part 2

One possible model for scientific publishing is the overlay journal, which takes some interdisciplinary theme and provides links to papers published elsewhere. By providing links rather than republishing, the overlay journal provides a service to both the reader, by linking to many publications, and the publishers, by bringing more eyeballs to their sites.     

平行机器人与平行无人系统:框架、结构、过程、平台及其应用

本文将基于ACP（Artificial societies,computational experiments,parallel execution）的平行系统思想与机器人领域相结合,形成一种软硬件相结合的框架,为无人机、无人车、无人船在复杂环境中实验、学习与实际工作提供便捷、安全的平台,即平行无人系统.本文从平行机器人的基本概念出发,提出平行无人系统的基本框架,并介绍了各模块的基本功能与实现方法,探讨了其中的关键技术.然后本文围绕无人机、无人车、无人船三个方面展望了无人平行系统在实际中的应用和所面临的挑战,提出了平行无人系统的未来发展方向.     

基于非功能需求的软件体系结构演化

对非功能需求NFRs进行了描述,根据功能需求、NFRs与SA的关系,定义了基于NFRs的SA演化,使用构件组合运算和结构工作链对软件体系结构的非功能特性进行了评估,根据评估结果,给出了基于NFRs的SA演化模型。     

Kinematics, dynamics and construction of a planarly actuated parallel robot

Kinematic and dynamic analysis of a parallel robot consisting of three planarly actuated links, is presented in this paper. Coordinated motion of three planar motors, connected to three fixed-length links, produces a six-degrees-of-freedom motion of an output link. Its extremely simple design along with much larger work volume than the commonly used parallel robots make this high performance-to-simplicity ratio robot very attractive. Experimental model verifies the unique combination of large work volume and high accuracy of this robot.     

On the Turing Completeness of the Semantic Web

The evidenced fact that “Linking is as powerful as computing” in a dynamic web context has lead to evaluating Turing completeness for hypertext systems based on their linking model. The same evaluation can be applied to the Semantic Web domain too. RDF is the default data model of the Semantic Web links, so the evaluation comes back to whether or not RDF can support the required computational power at the linking level. RDF represents semantic relationships with explicitly naming the participating triples, however the enumeration is only one method amongst many for representing relations, and not always the most efficient or viable. In this paper we firstly consider that Turing completeness of binary-linked hypertext is realized if and only if the links are dynamic (functional). Ashman’s Binary Relation Model (BRM) showed that binary relations can most usefully be represented with Mili’s pE (predicate-expression) representation, and Moreau and Hall concluded that hypertext systems which use the pE representation as the basis for their linking (relation) activities are Turing-complete. Secondly we consider that RDF –as it is- is a static version of a general ternary relations model, called TRM. We then conclude that the current computing power of the Semantic Web depends on the dynamicity supported by its underlying TRM. The value of this is firstly that RDF’s triples can be considered within a framework and compared to alternatives, such as the TRM version of pE, designated pfE (predicate-function-expression). Secondly, that a system whose relations are represented with pfE is likewise going to be Turing-complete. Thus moving from RDF to a pfE representation of relations would give far greater power and flexibility within the Semantic Web applications.     

基于链接聚类的代谢网络社团结构研究

社团结构分析有助于识别代谢网络中的功能模块,有助于理解代谢网络的结构和功能关系,是代谢网络研究领域的一个重要研究课题。然而,当前的社团结构分析方法均依赖于对网络中的节点进行聚类分析,导致每个节点只能属于某一个社团。采用了一种对复杂网络中的链接进行聚类分析的方法,对高质量金黄色葡萄球菌代谢网络模型的巨强连通体进行了社团结构分析,得到了10个具有生物学意义的功能模块,结果表明链接聚类可用于识别新陈代谢网络中的功能社团。     

互联网的局域世界演化模型仿真研究

研究Internet拓扑有利于解决Internet上通信协议、病毒传播、拥塞控制等问题,针对不同的预测和改善Internet性能的目的,建立合适的拓扑模型是非常重要的。该文从复杂网络建模的角度出发,研究了自治系统层面Internet的拓扑特性,综合考虑了局域世界内的偏好连接、节点和链接的随机或优先消亡、节点间非线性优先连接、新节点所带来的外部链接及网络内新增的内部链接等诸多因素,提出了一个新的Internet局域世界演化模型ELWI。采用C＋＋和Matlab这两个工具来对Internet和所生成的ELWI拓扑进行研究,通过比较仿真结果发现,ELWI很好地刻画了自治系统层面Internet的无标度、小世界和局域世界等诸多特性及其演化行为。     

多逻辑链路间共享令牌调度流量负载模型

针对宽带接入多逻辑链路中普遍存在的流量不稳定问题,提出一种多逻辑链路间令牌调度模型,通过在多链路间动态调度令牌,使链路的流量趋向稳定分布,达到流量负载均衡的目的。模拟实验结果证明,该模型有较好的流量调控能力,能根据实际需要控制各个链路的流量,改善出口时间响应特性,提高链路利用率。     

Implementation of the XML linking language XLink by functional methods

This paper is devoted to the construction of processors of a language for describing links between resources in XML documents, which is based on the application of functional programming methods and representation of XML data as S-expressions. An implementation in the high-level functional programming language Scheme, the system SXLink compatible with the XLink specification of the W3 consortium, is considered. A survey and comparative analysis of the existing implementations of the XLink language are given. Typical difficulties associated with the implementation and use of the language are identified, and methods to overcome them are discussed. Examples of the application of the SXLink system to solving problems of processing links between resources in XML documents are considered. An SXLink application program interface based on the use of functions of the Scheme language as first-class objects is suggested. The application of this approach to constructing simple and powerful XLink processors is discussed.Translated from Programmirovanie, Vol. 31, No. 1, 2005. Original Russian Text Copyright © 2005 by Lizorkin, Lisovsky.     

Age differences in search of web pages: the effects of link size, link number, and clutter

Reaction time, eye movements, and errors were measured during visual search of Web pages to determine age-related differences in performance as a function of link size, link number, link location, and clutter. Participants (15 young adults, M = 23 years; 14 older adults, M = 57 years) searched Web pages for target links that varied from trial to trial. During one half of the trials, links were enlarged from 10-point to 12-point font. Target location was distributed among the left, center, and bottom portions of the screen. Clutter was manipulated according to the percentage of used space, including graphics and text, and the number of potentially distracting nontarget links was varied. Increased link size improved performance, whereas increased clutter and links hampered search, especially for older adults. Results also showed that links located in the left region of the page were found most easily. Actual or potential applications of this research include Web site design to increase usability, particularly for older adults.     

社交网络中基于IAUE模型的锚链识别

社交网络中的锚链识别对于跨网络信息传播、跨平台推荐、社交链预测等具有重要意义.针对当前锚链识别研究中准确率低的问题,提出了一种有效提高锚链识别准确率的方法：IAUE模型.该模型首先利用网络结构信息进行网络表征学习,然后利用BP神经网络、随机梯度下降和负采样等方法得到异构网络节点间的锚链候选集,最后辅以G-S算法精化锚链匹配结果,提高异构网络对齐的准确率.多个数据集上的实验结果表明,IAUE方法相比其他方法具有较高的性能和很好的泛化能力,可以较为准确地识别网络中的锚链.     

Lower bounds for the mixed capacitated arc routing problem

Capacitated arc routing problems (CARP) arise in distribution or collecting problems where activities are performed by vehicles, with limited capacity, and are continuously distributed along some pre-defined links of a network. The CARP is defined either as an undirected problem or as a directed problem depending on whether the required links are undirected or directed. The mixed capacitated arc routing problem (MCARP) models a more realistic scenario since it considers directed as well as undirected required links in the associated network. We present a compact flow based model for the MCARP. Due to its large number of variables and constraints, we have created an aggregated version of the original model. Although this model is no longer valid, we show that it provides the same linear programming bound than the original model. Different sets of valid inequalities are also derived. The quality of the models is tested on benchmark instances with quite promising results.     

Functional Networks

In this letter we present functional networks. Unlike neural networks, in these networks there are no weightsassociated with the links connecting neurons, and the internal neuron functions are not fixed but learnable. These functions are not arbitrary, but subject to strong constraints to satisfy the compatibility conditions imposed by the existence of multiple links going from the last input layer to the same output units. In fact, writing the values of the output units in different forms, by considering these different links, a system of functional equations is obtained. When this system is solved, the numberof degrees of freedom of these initially multidimensional functions is considerably reduced. One example illustrates the process and shows that multidimensional functions can be reduced to functions with a single argument. To learn the resulting functions, a method based on minimizing a least squares error function is used, which, unlike the functions used in neural networks, has a single minimum.     

Charles Babbage as an algorithmic thinker

While the career of the Charles Babbage (1791-1871) shows a remarkable range of interests, strong threads bind together several of the principal ones: algorithmic thinking, with intimate links to algebra and to semiotics. The links connect especially his mathematical researches in functional equations with his work on mathematical tables and on calculating machines, but they are evident also in some of his social and industrial concerns. Evidence is presented to show that Babbage was consciously aware of at least some of these links. Attention to them casts light upon his achievements     

天地一体化卫星网络拓扑场景仿真技术

网络仿真可为天地一体化卫星网络的新技术评测提供有力支撑。面向天地一体化卫星网络拓扑场景固有的异构性、动态性特点,提出一种天地一体化卫星网络拓扑场景仿真技术。设计了面向异构、动态卫星网络拓扑的统一描述模型,以及研究了基于统一描述模型的拓扑自动解析与仿真场景生成方法,提升了仿真场景生成的易用性;从是否时变性的角度出发,设计了面向各类星间链路与星地链路的分类方法,将链路分为时变性和非时变性两种,针对非时变性链路,通过引入链路模型预加载机制,提升了卫星链路的仿真效能以及响应速度;针对链路仿真过程中延时仿真精确度低的问题,设计了链路仿真校正策略,实现了卫星链路高逼真、实时、动态的仿真。构建了多种天地一体化卫星网络场景,实验结果表明：所提出的技术具备高效的卫星网络仿真拓扑的自动生成能力;与现有技术相比,该技术在卫星链路仿真效能与仿真逼真性方面具有明显优势。     

Motion Study of the Ornithopter with Periodic Wing Oscillations

The motion of an ornithopter, a flying robot, consisting of a body and two symmetric twolink wings, is considered. The device moves in a vertical plane perpendicular to the longitudinal axis of the robot. All the links of the object form a chain through cylindrical joints with parallel axes. A mathematical model of the ornithopter is developed based on a bird’s flight analysis taking into account the aerodynamic interaction of all the links with the environment. Sequences of flight phases are considered, each of which differs in the direction of motion of the wing links. As a result of numerical simulation, diagrams of the robot’s modes of motion are constructed (ascent, hovering, and descent) and the effect of the amplitude and frequency of oscillation of the wing links, as well as their area, is determined (the same wing area was achieved by varying the length and width of the wings).     

基于连接模型的局部优化算法在水域污染监测数据融合系统中的应用

针对水域污染监测数据融合系统中存在的困难，讨论了基于“连接”模型的局部优化算法及其应用。该模型采用非“抑制”连接，极大地减少了节点“连接”数和扇出数；各个节点只和相邻节点通过“连接”传递信息，竞争输出，保证了局部最优，同时为实现分布式计算提供了方便。在此模型的基础上本文用局部优化及其改进算法对一个水域污染监测问题进行了仿真研究，理论分析和计算结果表明，局部最优及其改进算法在保证搜索准确性的同时极大地减少了计算量，是解决水域污染监测问题的有力工具。