Early math matters: Kindergarten number competence and later mathematics outcomes.

Children’s number competencies over 6 time points, from the beginning of kindergarten to the middle of 1st grade, were examined in relation to their mathematics achievement over 5 later time points, from the end of 1st grade to the end of 3rd grade. The relation between early number competence and mathematics achievement was strong and significant throughout the study period. A sequential process growth curve model showed that kindergarten number competence predicted rate of growth in mathematics achievement between 1st and 3rd grades as well as achievement level through 3rd grade. Further, rate of growth in early number competence predicted mathematics performance level in 3rd grade. Although low-income children performed more poorly than their middle-income counterparts in mathematics achievement and progressed at a slower rate, their performance and growth were mediated through relatively weak kindergarten number competence. Similarly, the better performance and faster growth of children who entered kindergarten at an older age were explained by kindergarten number competence. The findings show the importance of early number competence for setting children’s learning trajectories in elementary school mathematics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mother and father connectedness and involvement during early adolescence.

The purpose of the current study was to explore how mother’s and father’s connectedness and involvement individually and collectively influence the lives of their children. Specifically, we asked how fathers’ and mothers’ parent–child connectedness and behavioral involvement influenced both problem behaviors (externalizing and internalizing behaviors) and positive outcomes (prosocial behaviors and hope) during early adolescence. Data for this study were taken from the Flourishing Families Project, from which 349 mothers and fathers were selected, along with their early adolescent child (mean age = 11.23 years, SD = .96). Hierarchical regression analyses revealed (even after controlling for child age, gender, and self-regulation) that mothers’ and fathers’ contributions differed, primarily as a function of child outcome. Namely, father (but not mother) connectedness and involvement were negatively related to adolescents’ internalizing and externalizing behaviors, whereas mother (but not father) connectedness and involvement were positively related to adolescents’ prosocial behaviors and hope. We also found that when one parent’s involvement was low (for whatever reason), the other parent’s involvement made a significant and important contribution to the child’s well-being, particularly in the area of internalizing behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

商品混凝土的早期轴向拉伸试验研究

利用自行研制的试验装置进行了早龄期商品混凝土的轴向拉伸试验,成功地解决了混凝土试验对中困难的难题。分别得出了轴心抗拉强度和受拉弹性模量随龄期的发展变化规律,并在试验数据的基础上经过回归分析分别得出了轴心抗拉强度和受拉弹性模量随龄期增长的经验公式,为进一步防止和控制混凝土结构的早期裂缝提供了准确可靠的力学性能参数。     

数值积分自动终止的算法及其工程应用

基于扩展等面积准则(EEAC)稳定性定量分析理论,提出了数值积分的自动终止算法,既大大减少了计算量,又保证不会因为积分时段太短而将多摆失稳的算例判为稳定。该算法根据主导互补簇的簇内非同调程度来反映轨迹在观察时段以后失稳的可能性：当稳定裕度足够大,且互补簇簇内的非同调性足够小时,受扰轨迹在观察时段以后也不会发散。为此,定义了簇内非同调性指标,并开发了识别可疑动态鞍点及可疑最远点的方法。仿真及近3年的大量工程实践证实了该算法的可靠性和有效性。     

企业财务风险预警系统研究

本文论述了企业财务风险的识别和分析 ,设计了适应我国企业具体特点的财务风险预警系统的结构与子系统、模型 ,提出了建立企业财务风险预警系统的相关对策     

区分服务网络的协作可调整RED算法

文章描述了一种适用于区分服务网络的新的RED改进算法协作可调整RED算法(CARED)。算法的思想是基于令牌桶标记器的标记概率建立业务实际速率与承诺速率间的定量关系,并以这个关系动态调整下游节点中CARED的丢包概率。为了实现CARED,文章还提出了一种标记概率的计算方法基于包数的滑动窗口测量算法(NSWM)。文中通过详实的仿真实验证明了定量关系的正确性,同时验证了CARED算法不仅为区分服务提供了有效的拥塞控制功能,也保障了区分服务的不同性能要求。     

低渗透油田启动压力梯度研究

胜利油区五号桩油田桩74块为低渗透油田。根据该油田启动压力梯度的测量结果。结合现场生产数据,初步分析了低渗透油田启运压力梯度的趋势及其对注水开发的影响,提出低渗透油田的开发应以早期注水为宜。     

预警探测系统资源调配技术设计与研究

以弹道导弹目标预警探测为背景,立足于解决预警探测系统下调配技术问题,对预警资源调配技术的业务流程、功能组成及关键技术进行了设计与研究,提出了基于对预警雷达的任务执行状态、重点目标探测状态、预警雷达资源分布状态实时监控及异常判定,同步生成相应调配策略的方法,达到了提升系统内多传感器探测效能、合理化分配重点目标的目的,该技术方法已通过实装验证并成功应用于实际系统。     

基于误差分析的雷达估测降水集成方法

以淮河流域为对象,在假设Z-I关系法、平均校准法、最优插值法、卡尔曼滤波和最优插值联合校准法以及卡尔曼滤波校准法等五种降水定量估测模式对于不同的降水类型而言能力有所差异的基础上,通过对前期降水定量估测结果误差变化的分析,以统计方差为判别标准来选取最佳的估算方法,进行多种估测结果的集成.对2007年7月上旬降水过程的应用结果分析表明:在降水强度较小的情况下,该方法是一种有效的集成方法,能够提高降水定量估测的能力;但是在降水强度较大的情况下,集成效果不佳.     

使用提前放闪电避雷针对短波测向天线场直击雷防护

本文对短波测向天线场直击雷防护的几种方法进行分析,提出了一种使用提前放闪电避雷针进行天线场直击雷防护的简单实用方法。