双曲回转面截交线性质探讨

用图解、解析二种方法，研究了单叶、双叶双曲回转面截交线的性质，对解决双曲回转面的相关问题及使用计算机绘图提供了理论依据．     

龙永煤田瓦斯地质因素初探

在介绍龙永煤田地质概况的基础上,分析了矿区瓦斯涌出特征;从煤层顶、底板岩性特征、地质构造、煤层埋藏深度和地下水等方面分析了影响瓦斯赋存的地质因素,对可能出现高瓦斯的井田(块段)或矿井进行了预测.     

用有限自动机和拓扑排序理论提高MIS开发效率

利用有限自动机和拓扑排序理论编写的一个工具软件．能直接处理数据库分析人员利用CASE工具产生的带中文注释的表定义DDL脚本文件．并可按引用完整性的要求。对各条DDL语句自动排序后．直接在RDBMS中创建用DDL语句定义的各表。使数据库分析段和程序设计阶段有机结合起来，提高了工作效率；同时，由于脚本文件已含有表名、字段名的详细注释，可省去相应的中文数据字典，也减少了文档维护的工作量。     

利用硅藻土提高化肥肥效的研究

通过对硅藻土结构观察、养分吸附和不同硅藻土与肥料比例肥效试验,结果表明,硅藻土具有多孔质结构,湿润后孔隙明显增大,对N、P有较强吸附作用,能吸附2.5%的N和37.4%的P;施用1∶10硅藻土肥的比施用化学肥料的增产9.8%,比施用化学肥料的多吸收20.4%的N,18.6%的P和12.8%的K,值得在生产上推广应用。     

Global stabilization and asymptotic tracking for a class of nonlinear systems by means of time‐varying feedback

A simple backstepping design scheme is proposed and sufficient conditions for non‐uniform in time global stabilization for parameterized systems by means of time‐varying feedback are established. Our methodology is applicable to a special class of systems that in general cannot be stabilized by static feedback and includes non‐holonomic systems in chained form. For this class of systems the main results on feedback stabilization enable us to derive sufficient conditions for the solvability of the tracking problem. Copyright © 2003 John Wiley & Sons, Ltd.     

Scaling Gross Primary Production (GPP) over boreal and deciduous forest landscapes in support of MODIS GPP product validation

The Moderate Resolution Imaging Radiometer (MODIS) is the primary instrument in the NASA Earth Observing System for monitoring the seasonality of global terrestrial vegetation. Estimates of 8-day mean daily gross primary production (GPP) at the 1 km spatial resolution are now operationally produced by the MODIS Land Science Team for the global terrestrial surface using a production efficiency approach. In this study, the 2001 MODIS GPP product was compared with scaled GPP estimates (25 km²) based on ground measurements at two forested sites. The ground-based GPP scaling approach relied on a carbon cycle process model run in a spatially distributed mode. Land cover classification and maximum annual leaf area index, as derived from Landsat ETM+ imagery, were used in model initiation. The model was driven by daily meteorological observations from an eddy covariance flux tower situated at the center of each site. Model simulated GPPs were corroborated with daily GPP estimates from the flux tower. At the hardwood forest site, the MODIS GPP phenology started earlier than was indicated by the scaled GPP, and the summertime GPP from MODIS was generally lower than the scaled GPP values. The fall-off in production at the end of the growing season was similar to the validation data. At the boreal forest site, the GPP phenologies generally agreed because both responded to the strong signal associated with minimum temperature. The midsummer MODIS GPP there was generally higher than the ground-based GPP. The differences between the MODIS GPP products and the ground-based GPPs were driven by differences in the timing of FPAR and the magnitude of light use efficiency as well as by differences in other inputs to the MODIS GPP algorithm—daily incident PAR, minimum temperature, and vapor pressure deficit. Ground-based scaling of GPP has the potential to improve the parameterization of light use efficiency in satellite-based GPP monitoring algorithms.     

Determinants of the Relative Advantage of a Structured SDM During the Adoption Stage of Implementation

This research investigates a new theoretical model for examining the relationships between user perceptions during innovation adoption. We have taken several innovation-related variables and constructed a framework for assessing the ability of a technology to improve worker performance. Prior research has not addressed the appropriate relationship between innovation adoption-related variables as applied to information systems development methodologies (SDM). This study attempts to use innovation-related variables created by Moore and Benbasat (Information Systems Research 2(3) (1991) 192–222) and Davis (MIS Quarterly 13(3) (1989) 319–340) to propose a framework useful by project managers in designing innovations that will successfully support the efforts of technology users. A framework is proposed, tested, and modified in the context of using an SDM to govern large systems development operation. Forty-seven users within a military software development organization were surveyed about their perceptions of a recently implemented structured SDM. A proposed model of innovation adoption perceptions was tested using correlation and partial least squares regression. Findings suggest a model for predicting the perceived relative advantage of SDMs in the adoption stage of their implementation which is useful in designing techniques in the IS development organizational function.     

论《管理信息系统》思想理念及方法的重要意义

本文从中国信息系统现状分析入手 ,在对信息系统作简要介绍的基础上从企业和开发者两方面分层次论述了《管理信息系统》开发中对其思想理念和方法进行宣传培训的重要性     

5种指针分析算法的精度和效率比较

指针分析的研究已经有20多年的历史，也发表了很多相关的算法。对于研究者和工程人员来说，对不同的指针分析算法进行研究并用统一的标准进行精度及效率等内容的对比，是一件有意义的工作。考察了5种具有代表性的指针分析算法，并在固定外界影响因素的条件下对它们的精度和效率进行了测量和比较，最后分析了指针分析的结果如何影响一些客户分析的精度和效率。     

信息论在异常检测中的应用

异常检测能有效地检测出新类型的攻击,但是目前大多数入侵检测使用的异常检测技术都缺乏理论指导,通常是经过反复的实验建立检测模型,这样建立的模型只适用于某些环境,不具有通用性。该文提出了一种可以指导异常检测的理论基础———信息论,介绍了应用在异常检测中的几种信息论的方法,包括熵,条件熵,相对(条件)熵,信息量。利用这些方法可以指导异常模型建立过程和解释模型性能。最后该文还通过举例说明了这种理论的可行性和必要性。