When variability matters more than meaning: The effect of lexical forms on use of phonemic contrasts.

During the first half of the 2nd year of life, infants struggle to use phonemic distinctions in label–object association tasks. Prior experiments have demonstrated that exposure to the phonemes in distinct lexical forms (e.g., /d/ and /t/ in daddy and tiger, respectively) facilitates infants' use of phonemic contrasts but also that they struggle to generalize the use of phonemic contrasts to novel syllabic contexts (Thiessen, 2007; Thiessen & Yee, 2010). Further, in prior research, infants have been provided only with experience in lexical forms that refer to novel objects, while many lexical forms in the natural environment do not have easily identified visual referents. The experiments in this article show that even lexical forms without referents can facilitate use of phonemic contrasts. Additionally, the results indicate that when lexical forms provide infants with enough variability (for example, a consonant followed by multiple different vowels), infants are able to generalize to novel contexts. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The protective effects of neighborhood collective efficacy on British children growing up in deprivation: A developmental analysis.

This article reports on the influence of neighborhood-level deprivation and collective efficacy on children’s antisocial behavior between the ages of 5 and 10 years. Latent growth curve modeling was applied to characterize the developmental course of antisocial behavior among children in the E-Risk Longitudinal Twin Study, an epidemiological cohort of 2,232 children. Children in deprived versus affluent neighborhoods had higher levels of antisocial behavior at school entry (24.1 vs. 20.5, p     

从小区绿化到景观生态——珠江三角洲城市居住区环境的发展

社会经济的迅速发展以及中西方文化的交流使珠江三角洲城市居住区环境发生了巨大的变化，主要体现在外延的扩大和内涵的丰富上。特别是居住区景观设计思想的确立，使珠江三角洲城市居住区环境演化出现了新的趋势：从小区绿化模式走向景观生态模式。     

Livable Streets,Livable Arterials? Characteristics of Commercial Arterial Roads Associated With Neighborhood Livability

Problem, research strategy, and findings: Planners and engineers traditionally consolidate motorized traffic onto arterial roads that pose challenges for surrounding neighborhoods. We investigate the positive and negative impacts of commercial arterials with nodes of activity on the livability of surrounding neighborhoods. We examine 10 arterials in Denver (CO) and survey respondents in adjacent neighborhoods, asking how they view those arterials. We use factor analysis to create a typology of neighbors' perceptions of these arterials. Neighbors like arterials that they perceive as a) vibrant with good transit access and b) quiet and clean; they dislike arterials that they perceive as a) unpleasant and b) sketchy. Vibrant arterials contribute to the perceived livability of the surrounding neighborhoods, whereas sketchy arterials are negatively associated with livability, but the same arterials are often simultaneously vibrant and sketchy. Residents clearly value the social functions that arterials provide and seem less aware of traffic volumes; some low-volume arterials are not more livable than those with higher traffic volumes. Our findings are limited by the small sample size; we do not try to validate objective measures of livability with residents' perceptions.

Takeaway for practice: Arterials can be good places for surrounding neighborhoods while still serving as major traffic corridors; accessibility and mobility do not always conflict. Planners should develop economic development plans for affected neighborhoods and enhance neighborhood livability by encouraging active land uses on arterials, maintaining the safety and cleanliness Livable Streets, Livable Arterials? Characteristics of Commercial Arterial Roads Associated With Neighborhood Livability Carolyn McAndrews and Wesley Marshall of arterials, and enhancing the pedestrian environment along those arterials.     

旧城更新中城市肌理的微观呈现——以武昌旧城解放路为例

旧城区更新过程中,文脉受到越来越多的关注,而城市肌理作为文脉的重要表征方式,理应受到足够的重视。该文通过分析城市肌理对城市发展的作用及肌理在街区层面上的微观表达,指出了城市肌理在延续文脉的基础上实现城市有序更新的重要性。结合在武昌旧城解放路商业街的调查研究和更新实践,针对旧城保护更新与城市发展的矛盾,提出了一种以城市肌理作为指导,用建筑比例和街区尺度等要素为手段的旧城区更新方法,为旧城区更新提供了一种思路。     

基于可搜索24邻域的A*算法路径规划

针对A^*算法在移动机器人路径规划时求解得到的路径长度不是最优并且转折点较多的问题,提出了可搜索24邻域的A^*算法路径规划.该方法在传统A^*算法的基础上进一步改进其启发搜索策略,将传统A^*算法的可搜索邻域个数从离散的8个扩展到24个,进而增加更多的搜索方向.结果表明,改进的A^*算法实现了路径长度更短的目的,同时降低了转折点数,且移动机器人的运行路径也更加平滑.本文方法具有较强的实际意义和应用背景,通过实际运行过程验证了其设计方法具有一定的有效性.     

用Dziok-Srivastava算子定义的亚纯多叶函数类

设∑p为E0={z:0<|z|<1}内解析且形为f(z)=z-p ∑∞n=1anzn-p的p叶函数全体组成的类．利用Dziok-Srivastava算子定义了p叶亚纯函数类∑p的子类Wp,q,s(α1,α),并定义了亚纯多叶函数f(z)的邻域．利用邻域概念建立了函数f(z)的邻域与函数类Wp,q,s(α1,α)之间的包含关系,推出了亚纯P叶函数f(z)属于类Wp,q,s(α1,α)的充分条件,并利用充分条件推出函数类Wp,q,s(α1,α)中满足条件∑∞n=1(n |n-2α|/2α)Гn(α1)|an|≤1的函数的一些性质．     

元胞自动机可逆性研究

元胞自动机是对复杂适应系统建模的重要理论工具。可逆性是元胞自动机的一个重要属性,是模拟物理可逆空间的必要条件。本文介绍元胞自动机的基本概念、可逆性和可计算性,并介绍一维可逆元胞自动机可计算的证明思路。     

求解单调线性互补问题的邻域跟踪内点算法

把艾文宝的邻域跟踪算法推广到单调线性互补问题（LCP）,用2-范数代替1-范数来定义宽邻域。由于单调LCP的迭代方向不再具有正交性,因此算法的理论分析比线性规划复杂。证明了算法的迭代复杂性为O（n～（1/2）L）。通过证明对偶间隙关于搜索步长的单调性,使得算法易于执行。数值实验显示了该算法的有效性。     

An efficient parallel algorithm of N-hop neighborhoods on graphs in distributed environment

N-hop neighborhoods information is very useful in analytic tasks on large-scale graphs, like finding clique in a social network, recommending friends or advertising links according to one’s interests, predicting links among websites and etc. To get the N-hop neighborhoods information on a large graph, such as a web graph, a twitter social graph, the most straightforward method is to conduct a breadth first search (BFS) on a parallel distributed graph processing framework, such as Pregel and GraphLab. However, due to the massive volume of message transfer, the BFS method results in high communication cost and has low efficiency. In this work, we propose a key/value based method, namely KVB, which perfectly fits into the prevailing parallel graph processing framework and computes N-hop neighborhoods on a large scale graph efficiently. Unlike the BFS method, our method need not transfer large amount of neighborhoods information, thus, significantly reduces the overhead on both the communication and intermediate results in the distributed framework.We formalize the N-hop neighborhoods query processing as an optimization problem based on a set of quantitative cost metrics of parallel graph processing. Moreover, we propose a solution to efficiently load only the relevant neighborhoods for computation. Specially, we prove the optimal partial neighborhoods load problem is NP-hard and carefully design a heuristic strategy. We have implemented our algorithm on a distributed graph framework- Spark GraphX and validated our solution with extensive experiments over a number of real world and synthetic large graphs on a modest indoor cluster. Experiments show that our solution generally gains an order of magnitude speedup comparing to the state-of-art BFS implementation.