Spectral analysis of phylogenetic data

The spectral analysis of sequence and distance data is a new approach to phylogenetic analysis. For two-state character sequences, the character values at a given site split the set of taxa into two subsets, a bipartition of the taxa set. The vector which counts the relative numbers of each of these bipartitions over all sites is called a sequence spectrum. Applying a transformation called a Hadamard conjugation, the sequence spectrum is transformed to the conjugate spectrum. This conjugation corrects for unobserved changes in the data, independently from the choice of phylogenetic tree. For any given phylogenetic tree with edge weights (probabilities of state change), we define a corresponding tree spectrum. The selection of a weighted phylogenetic tree from the given sequence data is made by matching the conjugate spectrum with a tree spectrum. We develop an optimality selection procedure using a least squares best fit, to find the phylogenetic tree whose tree spectrum most closely matches the conjugate spectrum. An inferred sequence spectrum can be derived from the selected tree spectrum using the inverse Hadamard conjugation to allow a comparison with the original sequence spectrum. A possible adaptation for the analysis of four-state character sequences with unequal frequencies is considered. A corresponding spectral analysis for distance data is also introduced. These analyses are illustrated with biological examples for both distance and sequence data. Spectral analysis using the Fast Hadamard transform allows optimal trees to be found for at least 20 taxa and perhaps for up to 30 taxa. The development presented here is self contained, although some mathematical proofs available elsewhere have been omitted. The analysis of sequence data is based on methods reported earlier, but the terminology and the application to distance data are new.     

空燃比控制中的数据采集和处理

在汽油机空燃比控制中，需要监视汽油机动力性变化。本文介绍了汽油机动力信号的采集系统和数据处理，并经实验证实。     

框架—抗震墙高层建筑抗震墙的计算机辅助设计

本文成功地研制了地震作用下框架-抗震墙结构中抗震墙的计算机辅助设计系统SWCAD.并指出,优化设计思想是结构CAD系铣中不可分割的组成部分,本文提出一个新的概念:制图模式及模式填表.这一概念的提出,为解决长期以来困扰着CAD科研界的计算机制图方法统一化问题提供了一种可能性,为CAD系统中图形数据库的建立和程序的结构化指明了方向.     

动态数据的决策作用

本文阐述企业管理中,各数据在流动中的相互影响与相互制约的关系,并示例分析具有反馈干预的动态数据在系统约束条件下的决策性.     

基于VRGS的交通流微观仿真软件的开发

基于ＶＲＧＳ的交通流微观仿真软件对交通网络引入ＶＲＧＳ后的交通流进行仿真。本文阐述仿真模型的设计思想,介绍模型的框架结构,说明采用ＶｉｓｕａｌＢａｓｉｃｆｏｒＷｉｎｄｏｗｓ的程序实现方法。     

七号信令集中监测系统的数据管理系统

七号信令网是电信网的重要组成部分,其运行质量直接影响到电信网及其各种业务的运行稳定性和实际效益。在集中监测系统框架的基础上,提出了在系统中建立多个数据库和数据仓库相结合的方案进行数据管理,并对数据管理系统的组成结构、逻辑结构、数据存储与应用做了进一步的研究。     

数据选择和译码显示的实验设计

数据选择器和译码器是数字集成电路中应用较多的器件之一，该文通过具体电路分析了利用数据选择器、显示译码器、变量译码器和计数器等器件构成的数据选择分时传输组成动态译码显示电路，阐述了所述电路在实验教学中所能达到的目的。     

基于CPLD的高速采集系统设计

采用高速A/D转换器和CPLD设计出了高速数据采集系统，利用多字节写入、单字节读出的方法降低数据写入的相对速度，实现了高速、大容量连续采样数据的存储．该系统既降低了生产成本及设计的复杂程度，又不失灵活性和实时性，是一种比较合理的高速数据采集方案．     

测井资料分析系统接口电路设计

从一种超声模拟测井记录的井下信号、深度信号送微机处理的实际要求出发，分析井下信号数据采集的工作原理，阐述了与１２位Ａ／Ｄ转换器实时配套工作的双存储体工作时序。通过对深度信号的解调，提出了一种解决４ＦＳＫ解调的有效方法。     

Pushing Multiple Convertible Constrains into Frequent Itemsets Mining

Constraint pushing techniques have been developed for mining frequent patterns and association rules. How ever, multiple constraints cannot be handled with existing techniques in frequent pattern mining. In this paper, a new algorithm MCFMC （mining complete set of frequent itemsets with multiple constraints） is introduced. The algorithm takes advantage of the fact that a convertible constraint can be pushed into mining algorithm to reduce mining research spaces. By using a sample database, the algorithm develops techniques which select an optimal method based on a sample database to convert multiple constraints into multiple convert ible constraints, disjoined by conjunction and/or, and then partition these constraints into two parts. One part is pushed deep inside the mining process to reduce the research spaces for frequent itemsets, the other part that cannot be pushed in algorithm is used to filter the complete set of frequent itemsets and get the final result. Results from our detailed experi ment show the feasibility and effectiveness of the algorithm.