测评软件生成系统的设计与实现

本文讨论了一个具有通用性的测试评估软件生成系统的设计思想和实现方法，给出了该生成器的系统组成、数据组织结构、查询搜索方式以及用户界面的设计。该系统具广泛的应用领域和实用意义。     

SQL的现状及其研究与发展

一、SQL简介 如果说七十年代关系数据库还处于研制实验阶段,那么到了八十年代大量关系数据库商用产品的面市几乎占据了整个数据库市场,其中的原因在于它们使用了统一的语言界面,那就是,SQL成为了关系数据库的通用语言。 1974年．IBM公司San Jose研究实验室的D．D．Chamberlin在开发SEQUEL-XRM原型时提出了SE-QUEL(Structured English Query Language),1976年又修改成为SEQUEL／2．也就是目前的SQL(StructuredQuer Language)。SEQUEL／2主要成形于IBM的Sys-tem R原型中[2],并在原有基础上大加扩展,其后逐渐完善并最终成为一种完备的结构化数据库查询语言。     

Numerical modeling of combustion processes and pollutant formations in direct-injection diesel engines

The Representative Interactive Flamelet (RIF) concept has been applied to numerically simulate the combustion processes and pollutant formation in the direct injection diesel engine. Due to the ability for interactively describing the transient behaviors of local flame structures with CFD solver, the RIF concept has the capabilities to predict the auto-ignition and subsequent flame propagation in the diesel engine combustion chamber as well as to effectively account for the detailed mechanisms of soot formation, NO_X formation including thermal NO path, prompt and nitrous NO_X formation, and reburning process. Special emphasis is given to the turbulent combustion model which properly accounts for vaporization effects on the mixture fraction fluctuations and the pdf model. The results of numerical modeling using the RIF concept are compared with experimental data and with numerical results of the commonly applied procedure which the low-temperature and high-temperature oxidation processes are represented by the Shell ignition model and the eddy dissipation model, respectively. Numerical results indicate that the RIF approach including the vaporization effect on turbulent spray combustion process successfully predicts the ignition delay time and location as well as the pollutant formation.     

数据采集与监控软件Genie

Genie是具有国际先进水平的数据采集与监控软件，它提供了一个面向对象的图形化用户界面，因此简化了数据采集过程、控制应用程序开发和操作员界面。本文介绍了Genie的特点、功能、基本用途以及VISUALBA－SIC在设计这类监控软件中的作用。     

Model validation and model structure determination

This paper gives a tutorial overview of basic approaches for model validation and model structure determination.Work partially supported by the Swedish Research Council for Engineering Sciences under contract 98-654.     

《宏观经济学》课程教学体系梳理

宏观经济学从资源如何充分利用这一独特的研究视角出发，以国民收入的决定为核心，以从二部门到部门到四部门为横线，从简单模型到扩展模型到总供求模型为纵线，从理论到政策为立线，构造了一个立体的理论框架体系。对宏观经济学的理论脉络进行梳理，能帮助学生提纲挈领地把握宏观经济学的理论体系。     

条件概率关系数据库模型

现实世界中大量存在着的不确定性信息，关系数据库模型仅视它们为空值，有必要增强其处理这类信息的能力，文章在总结前人工作的基础上推广关系数据库模型，创建有效处理随机型不确定性信息的条件概念关系数据库模型，该模型通过在关系模式中增加一个条件概率测度属性，为每条记录指定适当的条件概率的途径，来表示不确定性信息。文中以对象码为基本工具，创建了条件概率关系结构；以特征函数为基本工具，定义了一套基于该结构的代数运算规则。条件概率的语意比概率的语意广泛，灵活，因而该模型能有效克服概率关系模型的许多不足。     

Extending boosting for large scale spoken language understanding

We propose three methods for extending the Boosting family of classifiers motivated by the real-life problems we have encountered. First, we propose a semisupervised learning method for exploiting the unlabeled data in Boosting. We then present a novel classification model adaptation method. The goal of adaptation is optimizing an existing model for a new target application, which is similar to the previous one but may have different classes or class distributions. Finally, we present an efficient and effective cost-sensitive classification method that extends Boosting to allow for weighted classes. We evaluated these methods for call classification in the AT&;T VoiceTone^® spoken language understanding system. Our results indicate that it is possible to obtain the same classification performance by using 30% less labeled data when the unlabeled data is utilized through semisupervised learning. Using model adaptation we can achieve the same classification accuracy using less than half of the labeled data from the new application. Finally, we present significant improvements in the “important” (i.e., higher weighted) classes without a significant loss in overall performance using the proposed cost-sensitive classification method.     

Prediction and quality control of the melt index during production of high-density polyethylene

In polyolefin processes the melt index (MI) is the most important control variable indicating product quality. Because of the difficulty in the on-line measurement of MI, a lot of MI estimation and correlation methods have been proposed. In this work a new dynamic MI estimation scheme is developed based on system identification techniques. The empirical MI estimation equation proposed in the present study is derived from the 1 ^st -order dynamic models. Effectiveness of the present estimation scheme was illustrated by numerical simulations based on plant operation data including grade change operations in high density polyethylene (HDPE) processes. From the comparisons with other estimation methods it was found that the proposed estimation scheme showed better performance in MI predictions. The virtual sensor model developed based on the estimation scheme was combined with the virtual on-line analyzer (VOA) to give a quality control system to be implemented in the actual HDPE plant. From the application of the present control system, significant reduction of transition time and the amount of off-spec during grade changes was achieved