A combined nonparametric approach to feature selection and binary decision tree design

An efficient procedure which integrates feature selection and binary decision tree construction is presented. The nonparametric approach is based on the Kolmogorov-Smirnov criterion which yields an optimal classification decision at each node. By combining the feature selection with the design of the classifier, only the most informative features are retained for classification.     

Conceptual modeling of data base operations

A formalism adequate for the specification of behavioral properties of data bases is proposed. The formalism is a many-sorted first order predicate calculus, including a formalized notion of data base state. Both update and query requests are modeled through expressions by the use of predicates supplied in the language of the formal system, and are treated uniformly as a theorem proving process. The process consists of using the axioms defining the data base for either synthesizing a valid sequence of update operations (if such exists) or for answering the query.     

研究式教学法讲授Taylor中值定理

Taylor中值定理是高等数学教学的一个难点.传统的教学模式是:教师讲授→学生模仿练习→强化学生记忆.学生普遍感到内容抽象难懂、难以记忆.为了处理好这部分教学内容,笔者采用研究式教学法,引导学生在探究中去学习Taylor中值定理.其教学模式是:提出问题→进行研究活动(实验、观察、分析)→交流合作(包括教师与学生的合作交流、学生与学生的合作交流)→教师引导,得出结论→师生共同验证结论的正确性→总结、应用.实践证明,用研究式教学法讲授Taylor中值定理,有助于提高教学质量.     

对棉结形成原因与减少途径的研讨

对棉结的形成原因、减少途径进行了分析研究，指出了棉结形成的主要原因和减少棉结的主要途径，总结了棉结的检测方法与变化情况，提出了一些见解。     

新型磷脂酶Lecitase Ultra用于菜籽油脱胶的研究

利用新型磷脂酶Lecitase Ultra进行了菜籽油脱胶的研究，并应用表面响应法优化了该酶反应条件。在加酶量29．74mg／kg、pH4．87、温度48．2℃的优化条件下，菜籽油含磷量从150．6mg／kg能降到5mg／kg以下。     

科技档案在盐行业的利用与探索

阐述科技档案业务建设，基础服务功能，法制建设，制度建设。通过科技档案在企业技术管理，生产管理，设备管理，环境保护等方面的应用，显示出其独特的功能。     

Investigation of ductile iron casting process parameters using Taguchi approach and response surface methodology

To find the optimized levels of various casting parameters in the ductile iron casting, various casting defects and the rejection rate were observed from a medium scale foundry. The controlled values of different casting parameters such as pouring temperature, inoculation, carbon equivalent, moisture content, green compression strength, permeability and mould hardness were selected. Three different melts of metal with 0.4wt.%, 0.6wt.%, and 0.8wt.% inoculation(Fe-Si-Mg alloy and post inoculant) were produced using a 1-ton capacity coreless medium frequency induction furnace. L-27 orthogonal array with 3-level settings were chosen for the analysis. Responses for each run were observed. The signal-to-noise(S/N) ratio for each run was calculated using the Taguchi approach, and the optimized levels of different casting parameters were identified based on the S/N ratio. The analysis of variance for the casting acceptance percentage concludes that inoculation is the most significant factor affecting the castings' quality with a contribution percentage of 44%; an increase in inoculation results in a significant improvement in acceptance percentage of ductile iron castings. The experiment results showed that with the optimized parameters, the rejection rate was reduced from 16.98% to 6.07%.     

COMPUTER SIMULATION TECHNIQUES FOR A MOBILE SATELLITE COMMUNICATION CHANNEL

This paper gives a brief and systematic presentation of the computer simulation techniques of satellite communications, especially for a mobile satellite channel, based on a summarization of the author's exploration and experience in this area. It includes the equivalent complex baseband notation (ECBN) method, a very convenient mathematical form for software simulation; development of a multi-functional and expandable channel simulation system on a computer from L-band to Ka-band; channel impulse or frequency response estimation in real time by the technique burst-mode link analyser with least-squares algorithm (BMLA/LS), modelling and simulation of the channel fast fading due to multipath and shadowing; acquisition of the equivalent normalized binary signal-to-noise ratio (E_b/N₀) data at the channel input; and bit-error rate (BER) evaluation by the directly error-counting approach and the computational approach at the channel output in simulation.