用干簧管进行液位测量的方法探讨

本文介绍了液位测量中开发应用干簧管作浮子式液位计传感器件的工作原理和几个关键技术问题的处理方法。对于物位测量和其它领域也有参考意义和学术价值。     

区域产业竞争力分析:以苏中地区为例

提高区域综合竞争力,关键是提高区域产业竞争力。根据文章给出的区域产业竞争力指标体系,通过对苏中地区与周边地区产业竞争力状况的比较研究和对苏中地区产业竞争力情况的实证分析,可知提高苏中地区产业竞争力应从提高投入要素的知识技术含量、大力发展第三产业等五个方面作出制度安排。     

高T_c超导材料微波特性的自动化测量

采用单腔多模谐振腔,通过部分置换样品的方法,在程控标量网络分析系统上,实现了高 T_c 超导材料微波特性的自动化测量。该方法简单、准确,能同时测出超导样品的工作频率、微波表面阻抗、工作温度等多个参数,并能以图或表的形式给出测试结果。给出了3 cm 频段上YBCO 块材样品在77K 及附近温度下的测量结果,指出 YBCO 块材的微波特性还有待提高。     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.     

On Block Updating in Markov Random Field Models for Disease Mapping

Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components.     

多元化计量模式的现实思考--历史成本与公允价值择优并存

多元化计量模式的现实思考——历史成本与公允价值择优并存@谢桂芬$宁波高等专科学校经管系!浙江宁波315010~~     

三维Minkowski空间中有相等主曲率函数的一类特殊曲面的位置向量场

讨论三维Minkowski空间R2 .1中一类特殊曲面在主曲率函数相等时的情形 ,给出了这类曲面在这一情形下的位置向量场     

测定二氧化碳分子量的微型实验

利用自制的简易气体发生器和洗气装置对二氧化碳分子量测定微型实验作了进一步的探索和实践、测定结果不仅达到无机化学实验对测定精度的要求。而且更便于推广和普及．     

汉语词义和词汇系统的历史演变初探——以“投”为例

词汇是一个系统,词义也是有系统性的。运用“概念要素分析法”来分析词义,可以更好地归纳词义,并厘清词义之间的联系及其历史发展。以概念场为背景,考察各个概念域中的成员及其分布在不同历史时期的演变,是研究词汇系统历史演变的一种有效的方法。     

供应链管理中的信息流网络

本文对供应链管理中的信息流理论进行了探讨 ,指出了传统链式信息流模式的缺陷 ,分析了简单的网络式信息流模型的构造 ;阐述了信息流网络的特征与优势 ;对若干有待深入研究的问题进行了展望。