基于自然地理形态的道路测设及其曲线方程的拟合

在山区村镇及风景旅游名胜区的建设中，其道路的曲线测设，往往要基于自然地理形态进行，也就是路径的选择，有时具有不可选择性，且要求与实地具有最大的符合性。因此，其测设的作业方法不同于一般意义的道路测设；其曲线方程的建立，也是极其困难的。本就基于自然地理形态的道路测设工作的曲线类型的选择、曲线的拟合方法、曲线方程的建立及其数据的计算，提出了利用CAD技术进行曲线拟合、曲线方程的建立、曲线计算的实用技术方法。     

Fluctuations of Turbulent Bed Shear Stress

With the assumption that the bed shear stress fluctuates in a lognormal fashion, the probability density function (PDF) of the standardized bed shear stress is derived as a function of the relative shear stress intensity. The PDF is more skewed with larger relative intensities, but approaches a Gaussian function when the relative intensity is small. The computed PDF agrees well with the reported experimental data for flows over a smooth boundary. The higher-order moments of the bed shear stress, skewness, and kurtosis, are shown analytically to be also dependent on the relative intensity. The theoretical dependencies are then compared to a number of measurements available in the literature. The Reynolds number effect on the relative intensity is also discussed.     

大容量数据库如何避免ora-01555错误

本文分析了造成ora-01555错误的原因，并提出解决办法。ora-01555错误一直是DBA与developer争论的焦点，解决其问题应是双方协调的结果。     

基于模糊信息处理的中板轧机微机在线监测系统

中板轧机是中板厂最重要的生产设备，对其工况进行在线监测意义重大，各种传感器将轧机的工况信息传送给微机系统，微机系统将这些信息进行模糊处理，发出相关信息，指导系统安全，高效运行。     

Assessing the role of basic control measures, antivirals and vaccine in curtailing pandemic influenza: scenarios for the US, UK and the Netherlands

An increasing number of avian flu cases in humans, arising primarily from direct contact with poultry, in several regions of the world have prompted the urgency to develop pandemic preparedness plans worldwide. Leading recommendations in these plans include basic public health control measures for minimizing transmission in hospitals and communities, the use of antiviral drugs and vaccination. This paper presents a mathematical model for the evaluation of the pandemic flu preparedness plans of the United States (US), the United Kingdom (UK) and the Netherlands. The model is used to assess single and combined interventions. Using data from the US, we show that hospital and community transmission control measures alone can be highly effective in reducing the impact of a potential flu pandemic. We further show that while the use of antivirals alone could lead to very significant reductions in the burden of a pandemic, the combination of transmission control measures, antivirals and vaccine gives the most 'optimal' result. However, implementing such an optimal strategy at the onset of a pandemic may not be realistic. Thus, it is important to consider other plausible alternatives. An optimal preparedness plan is largely dependent on the availability of resources; hence, it is country-specific. We show that countries with limited antiviral stockpiles should emphasize their use therapeutically (rather than prophylactically). However, countries with large antiviral stockpiles can achieve greater reductions in disease burden by implementing them both prophylactically and therapeutically. This study promotes alternative strategies that may be feasible and attainable for the US, UK and the Netherlands. It emphasizes the role of hospital and community transmission control measures in addition to the timely administration of antiviral treatment in reducing the burden of a flu pandemic. The latter is consistent with the preparedness plans of the UK and the Netherlands. Our results indicate that for low efficacy and coverage levels of antivirals and vaccine, the use of a vaccine leads to the greatest reduction in morbidity and mortality compared with the singular use of antivirals. However, as these efficacy and coverage levels are increased, the use of antivirals is more effective.     

一种基于混沌的随机数发生器设计及其IC实现

在密码学、仿真学以及集成电路测试等许多领域 ,随机数起着重要的作用。在密码学中 ,通常要求所使用的随机数具有不可预测性。基于混沌现象 ,使用开关电容技术 ,用集成电路实现了一种硬件随机数发生器。测试结果表明 ,其产生的序列具有不可预测性 ,可以满足密码学的应用要求。     

开发有线电视收费管理系统需注意的问题

分析有线电视业务及用户管理中出现的问题与解决办法，为系统的开发建立数据模型，以确保有线电视网络公司和用户的利益。     

基于模糊理论的江垭水库移民安置区模式优选

水库移民安置区的优化选择关系到移民社区未来的社会稳定和可持续发展。为此,对影响移民安置区的指标体系进行了研究,利用模糊理论建立了优选模型,并通过江垭水库移民安置区的实际情况对模型进行了验证。结果表明,研究采用的指标体系和方法可满足移民安置区优选的需要。     

用模糊综合评判法评估钢制储罐的寿命

针对影响钢制储罐寿命的因素具有复杂性、非确定性以及时变性的特点,提出了用动态二级模糊综合评判的方法对其寿命进行评估,建立了评估的数学模型和评估流程。在对某石油库油罐的寿命分析中,考虑到保留所有评判因素的影响,采用了乘、加型模糊算子,并用层次分析法来确定评价指标权重。计算结果表明,该方法能够解决储罐寿命评估中的一些复杂因素的处理问题,具有一定的实际工程意义。     

A Bluetooth Routing Protocol Using Evolving Fuzzy Neural Networks

In this paper, a routing protocol which utilizes the characteristics of Bluetooth technology is proposed for Bluetooth-based mobile ad hoc networks. The routing tables are maintained in the master devices and the routing zone radius for each table is adjusted dynamically by using evolving fuzzy neural networks. Observing there exists some useless routing packets which are helpless to build the routing path and increase the network loads in the existing ad hoc routing protocols, we selectively use multiple unicasts or one broadcast when the destination device is out of the routing zone radius coverage of the routing table. The simulation results show that the dynamic adjustment of the routing table size in each master device results in much less reply time of routing request, fewer request packets and useless packets compared with two representative protocols, Zone Routing Protocol and Dynamic Source Routing.