基于EGM2008重力模型的高程测量方法探讨

为探求EGM2008重力模型在高程测量中的应用效果,利用江西省范围内不同区域的GPS水准点高程对EGM2008重力模型外部测量相对精度进行检核。结果表明,EGM2008重力模型高程测量精度优于RTKGPS和静态GPS拟合的高程精度。将EGM2008重力模型技术应用在抗旱提水项目的高程测量中,可以提高工效,同时提出了如何提高测量精度的应对措施。     

嵌入式操作系统功耗基准测试研究与实现*

在研究SPECpower_ssj2008和EECoMark两个功耗基准的前提下,提出了针对μC/OSⅡ内核功耗测试的基准程序和一种对可变函数功耗/性能的综合评估方法,最后将基准程序在功耗模拟器EMSIM上运行,分析实验结果,并根据结果提出对μC/OSⅡ的低功耗改进策略。实验结果表明了该方法的有效性。     

2008年中外林纾研究综述

北京奥运之年,海内外各方学者不论是在期刊论文的登载、学位论文的发布,还是学术专著的出版、文献资料的整理、学会的交流等方面,都取得了丰硕的成果。其研究势头之好,规模之盛,堪称是迎来了一个学术史上前所未有的“林纾年”。     

Credibility of Social Network Sites for Political Information Among Politically Interested Internet Users

Scholars have confirmed that political candidates are increasingly turning to social network sites (SNS) to persuade voters to vote for them, and that these sites have become prominent sources of political information. But a fundamental question arises about the sustainability of social networks as a campaign tool: How much do users trust the information they find there? This study employed an online survey to examine the degree to which politically interested online users view SNS as credible. SNS were ranked the least credible among the nine traditional and online sources examined. Reliance on social networks proved the strongest predictor of SNS credibility.     

RDMS4.5与CASS2008等高线绘制方法比较与实际应用

在不影响地形图精度的前提下,为使绘制等高线的方法更简捷、图形更加美观,利用RDMS4.5和CASS2008都具有根据高程点自动构网内插绘制等高线的功能,以绘制大马庄山区地形图等高线为例,进行比较.分析发现,RDMS4.5在绘制等高线时建立的DTM方法、修改数字地面模型、等高线拟合、注记等方面更有优势,而CASS2008在修饰等高线时具有比RDMS4.5更强的功能.因此,利用RDMS4.5绘制等高线线形好的优点,再结合CASS2008强大的CAD功能,使等高线的绘制更加简捷,节省了成图时间,大大提高了效率,从而为水利工程规划、设计和施工提供更好的服务.     

新世纪中国城市综合减灾规划问题研究——兼论北京奥运建设“三大理念”的安全减灾

美国“9.11”事件及2008年北京申奥的成功留给科技工作者的任务及思考很多。从中国城市规划战略视角出发，结合联合国一再倡导的“国际减灾战略”思想，围绕北京奥运建设“三大理念”，全面分析并论证了奥运建设这个庞大系统工程中的安全保障及防灾减灾问题。相信不仅对奥运安全建设本身，也对新世纪中国城市综合减灾规划战略制定并落实有所帮助和借鉴。     

《灯具一般安全要求与试验》标准:IEC 60598-1:2008版与GB 7000.1-2007版的差异(下)

介绍我们国家灯具通用标准《灯具一般安全要求与试验》GB7000.1-2007版与国际最新标准IEC60598-1:2008版的差异,用表格形式将两个版本标准差异进行详细地说明。     

Computation of a turbulent natural convection in a rectangular cavity with the low-reynolds-number differential stress and flux model

A numerical study of a natural convection in a rectangular cavity with the low-Reynoldsnumber differential stress and flux model is presented. The primary emphasis of the study is placed on the investigation of the accuracy and numerical stability of the low-Reynolds-number differential stress and flux model for a natural convection problem. The turbulence model considered in the study is that developed by Peeters and Henkes (1992) and further refined by Dol and Hanjalic (2001), and this model is applied to the prediction of a natural convection in a rectangular cavity together with the two-layer model, the shear stress transport model and the time-scale bound 2008_Article_BF02984327_TeX2GIFIE1.gif" alt=" $$\overline {v^2 } - f$$ " align="middle" border="0"> model, all with an algebraic heat flux model. The computed results are compared with the experimental data commonly used for the validation of the turbulence models. It is shown that the low-Reynolds-number differential stress and flux model predicts well the mean velocity and temperature, the vertical velocity fluctuation, the Reynolds shear stress, the horizontal turbulent heat flux, the local Nusselt number and the wall shear stress, but slightly under-predicts the vertical turbulent heat flux. The performance of the 2008_Article_BF02984327_TeX2GIFIE2.gif" alt=" $$\overline {v^2 } - f$$ " align="middle" border="0"> model is comparable to that of the low-Reynolds-number differential stress and flux model except for the over-prediction of the horizontal turbulent heat flux. The two-layer model predicts poorly the mean vertical velocity component and under-predicts the wall shear stress and the local Nusselt number. The shear stress transport model predicts well the mean velocity, but the general performance of the shear stress transport model is nearly the same as that of the two-layer model, under-predicting the local Nusselt number and the turbulent quantities.     

坦桑尼亚国家坐标系简介与某援建机场控制网建立

对坦桑尼亚国家坐标系的历史沿革、发展现状及使用方法进行了简要介绍;针对该国在机场行业无现行相关规范,同时机场建成后要满足ICAO的相关要求,制定了合理的技术方案,建立起满足某援建机场建设需要的机场GPS和水准测量控制网,给出了实现坐标系统转换的方法,有效克服了因UTM投影引起的长度变形;为今后相类似工程提供了参考经验。     

基于SQL Server 2008的数据挖掘系统在违法犯罪人员信息分析上的应用

首先对铁路公安机关情报分析的需求和SQL Server 2008的数据分析服务进行讨论,并着重探讨基于SQL Server 2008的数据挖掘系统在违法犯罪人员信息分析上的应用。经实例证明,该系统实现良好的分析决策功能。