基于多层数据库访问技术的自定义报表的研究

主要描述了一个基于多层数据库访问技术的自定义报表的实现原理.并简要介绍了部分实现方案和处理流程,举例说明了部分技术要点.     

川渝地区石油通信建设有关问题的探讨和建议

随着川渝地区输气干线管道的大规模改造和建设,川渝地区的石油光通信和其它配套通信建设也得到长足的发展,在建设中出现了一些需要认真探讨和思考的共性问题,结合近年来中石油管道通信和川渝地区石油通信建设的经验教训,对川渝地区石油通信建设有关共性问题进行初步的探讨,提出了相关建议,以利改进和促进今后川渝地区石油通信设计和建设。     

Dealing with expected and unexpected obstacles

Generality and locality have been proposed as two crucial properties for systems formalizing common-sense reasoning. The first is the ability of representing knowledge in a way that makes it usable in a wide class of circumstances. The second is the ability of using only a subset of the potentially available knowledge, namely the subset which is held to be relevant in a given circumstance. These two properties seem to be one the opposite of the other, since disregarding part of the available information (locality) may lead to a loss of generality. In this paper, we argue that this is not the case, and propose a general methodology for combining generality and locality. This methodology is essentially based on the notion of context. As a case study, we propose a formalization of the Glasgow-London-Moscow example and its mechanization in an interactive theorem prover, GETFOL.     

面向对象通用优化程序在VC＋＋平台上的实现

讨论了面向对象优化程序实现的机理及在VC＋＋编程平台上实现该程序的具体做法,给出了一个优化方法扩充的实例。最后用本文程序对参考文献中的优化问题进行计算,通过对比结果得出相应的结论。     

Technological and social changes into the third millennium and the impact on refrigeration

A technological revolution based on information technologies is reshaping the nature of society while globalisation has impacted on the location and nature of economic production and ownership. The scope of these changes indicates a transformation that is equal to the extent of the changes associated with the Industrial Revolution. At the beginning of the third millennium, it is possible to anticipate how these transformative changes will impact upon the way societies and people produce, communicate, manage and live. This paper will outline some of the major changes that have occurred, or will be likely to, over the next two decades, with particular attention to the way in which social institutions and social interaction will evolve. It will also pose questions about the implications for facets of refrigeration given the fundamentally different ways in which societies and individuals will interact with, and expect to use, various technologies.     

Evaluation of different biomass gasification modeling approaches for fluidized bed gasifiers

To develop a model for biomass gasification in fluidized bed gasifiers with high accuracy and generality that could be used under various operating conditions, the equilibrium model (EM) is chosen as a general and case-independent modeling method. However, EM lacks sufficient accuracy in predicting the content (volume fraction) of four major components (H₂, CO, CO₂ and CH₄) in product gas. In this paper, three approaches—MODEL I, which restricts equilibrium to a specific temperature (QET method); MODEL II, which uses empirical correlations for carbon, CH₄, C₂H₂, C₂H₄, C₂H₆ and NH₃ conversion; and MODEL III, which includes kinetic and hydrodynamic equations—have been studied and compared to map the barriers and complexities involved in developing an accurate and generic model for the gasification of biomass.This study indicates that existing empirical correlations can be further improved by considering more experimental data. The updated model features better accuracy in the prediction of product gas composition in a larger range of operating conditions. Additionally, combining the QET method with a kinetic and hydrodynamic approach results in a model that features less overall error than the original model based on a kinetic and hydrodynamic approach.     

双向线性回归方法

工程上迫切需要在现场或当前数据较少的情况下,建立高精度和高可靠度的现场经验公式.文中利用当前或现场检测数据与历史或试验室数据存在的共性信息,给出双向线性回归方法.此方法不仅能利用现场检测数据的个性信息,还能有效、合理地使用历史或试验室数据,有效扩大当前或现场数据的样本量,得到高精度的现场经验公式,同时利用该公式还可以得到高置信度的推定结果.将文中方法运用于回弹法检测混凝土强度中,有效解决了现场测强曲线建立问题.     

剃齿刀的通用性验算

简单介绍了剃齿刀的切削原理、设计原理及结构参数的选定,并以实际加工中比较常见的万能剃齿机YWA4232为例,详细叙述了径向剃齿刀BE-14-821的通用性验算的步骤及公式,解决了对现有的剃齿刀是否通用进行验算的问题,从而缩短了齿轮制造周期、降低了新购置刀具所带来的成本消耗。     

Calibration strategy and generality test of three-axis magnetometers

Calibration strategy will influence the calibration performance of three-axis magnetometers. In this paper, three different calibration strategies (symmetrical calibration, orthogonal calibration and random calibration) are introduced and verified by simulation and experiments. The experimental system mainly consists of three-axis fluxgate magnetometer (MAG3300), 2D nonmagnetic rotation equipment and proton magnetometer. The scalar value of magnetic field was obtained with proton magnetometer and considered to be the true value. Calibration performance of three different calibration strategies were analyzed and compared. Experimental results show that after calibration the scalar RMS error has dropped 88.5%, 85.5% and 87.6% respectively. To check the generality of the estimated error parameters, another site was chosen to be a validation position, and the calibration performance of three calibration strategies were tested and compared. After calibration, the scalar RMS error has dropped 83.2%, 78.9% and 78.8% respectively. Thus the symmetrical calibration is considered to be the best calibration strategy among three calibration strategies.     

Z缓冲消隐算法的改进

Z缓冲算法是一种比较简单的消隐算法,Z缓冲区的大小与屏幕的视图区大小相关,一般情况下设置成视图区的大小,因此该算法只适用于固定大小投影,即通用性差,另外当图形较小时又浪费空间.本算法通过动态生成相应Z缓存,从而适用于任何大小的图形,即通用性强,同时减小内存.