The design and implementation of an interactive data analysis package for a process computer

The paper highlights the requirement for a comprehensive program suite to facilitate data analysis. An attempt is made to integrate all the normal routines encountered in a scientific data processing environment into one package. Addition of new algorithms to the package is simplified by avoiding duplication of data handling and display segments, and by the chaining of existing options. The applications of the suite are illustrated using field derived data.     

Identification of the minimum effective dose for right-censored survival data

In this paper, we consider identifying the minimum effective dose (MED) in a dose-response study when survival data are subject to random right-censorship, where the MED is defined to be the smallest dose level under study that has survival advantage over the zero-dose control. To this end, we suggest single-step-down testing procedures based on three different types of weighted logrank statistics, respectively. The comparative results of a Monte Carlo error rate and power/bias study for a variety of survival and censoring distributions are then presented and discussed. The application of the testing procedures for identifying the MED is finally illustrated by using a numerical example of prostate cancer data.     

数据加密技术在计算机网络安全中的应用分析

在信息技术快速发展的今天,数据加密技术已经逐渐应用到很多领域,对人们日常的工作和生活也产生了一定的影响。但由于网络信息在共享的过程中存在一定的数据安全风险,因此其安全问题也受到人们的广泛关注。文章通过分析数据加密技术面临的安全风险问题,给出防范数据加密技术安全风险的措施,希望提高数据加密技术运行的安全质量。     

Regression models for grouped survival data: Estimation and sensitivity analysis

In this study, regression models are evaluated for grouped survival data when the effect of censoring time is considered in the model and the regression structure is modeled through four link functions. The methodology for grouped survival data is based on life tables, and the times are grouped in k intervals so that ties are eliminated. Thus, the data modeling is performed by considering the discrete models of lifetime regression. The model parameters are estimated by using the maximum likelihood and jackknife methods. To detect influential observations in the proposed models, diagnostic measures based on case deletion, which are denominated global influence, and influence measures based on small perturbations in the data or in the model, referred to as local influence, are used. In addition to those measures, the local influence and the total influential estimate are also employed. Various simulation studies are performed and compared to the performance of the four link functions of the regression models for grouped survival data for different parameter settings, sample sizes and numbers of intervals. Finally, a data set is analyzed by using the proposed regression models.     

数据仓库实现过程及在线分析

数据仓库技术是近几年来出现并迅速发展的一种技术,它可以充分利用数据仓库中已存储的信息,帮助决策者进行决策。本文在介绍数据仓库的定义和数据仓库决策支持系统原理的基础上,详尽地讨论了数据仓库中的数据抽取与转换方法,并对数据仓库实现过程进行了实例探索和在线分析,最后根据数据挖掘方法进行了实际的应用。本文就是采用微软SQL Server 2000数据仓库技术设计了一商业用的数据仓库,使读者可清楚了解数据仓库的决策支持系统的实现过程。     

一种多数据源的数据仓库填充方案

分析了数据仓库中数据填充存在的问题,为了保持数据仓库数据的全面性、完整性和数据仓库的质量,提出了一种多数据源的数据填充方案,并介绍了这种填充方案的结构和各模块的功能,具体讨论了同质和异质数据库数据源的数据转换模式,对于非数据库数据源,给出了从文本数据源和Web页面数据源获取数据的填充方法。     

数据加密技术在计算机安全中的应用分析

在经济社会飞速发展的今日,网络计算机已经成为人们工作生活的重要工具。网络的发展在给人们的工作生活带来便利的同时,也催生出了大量的网络黑客、计算机病毒,对计算机用户的信息安全带来极大的安全隐患。因此,进一步提高数据信息的保密性是当前计算机行业发展亟待解决的问题,本文章就数据加密技术在计算机安全中的应用做一浅显分析。     

Minimal data dependence abstractions for loop transformations: Extended version

Many abstractions of program dependences have already been proposed, such as the Dependence Distance, the Dependence Direction Vector, the Dependence Level or the Dependence Cone. These different abstractions have different precisions. Theminimal abstraction associated to a transformation is the abstraction that contains the minimal amount of information necessary to decide when such a transformation is legal. Minimal abstractions for loop reordering and unimodular transformations are presented. As an example, the dependence cone, which approximates dependences by a convex cone of the dependence distance vectors, is the minimal abstraction for unimodular transformations. It also contains enough information for legally applying all loop reordering transformations and finding the same set of valid mono- and multi-dimensional linear schedules as the dependence distance set.     

Modelling of a continuous food pressing process by dimensional analysis

This paper focuses on the development of a mathematical model of a continuous pressing operation where biscuit shape is formed. It identifies a functional relationship and predicts its parameter values using a set of observed data. Dimensional analysis was used to model biscuit thickness as a non-linear function of a number of predictor variables and multiple regression was applied for parameter estimation of the model. The results were satisfactorily tested against real data.     

NHPPREG: a computer program for the analysis of nonhomogeneous Poisson process data with covariates.

A program written in C is described which finds maximum likelihood estimates of regression coefficients and other relevant parameters for a point process with covariates. The data are assumed to come from a Poisson point process and may be modelled, at the user's choice, either totally parametrically or semi-parametrically. Furthermore, extra Poisson variation may be introduced, in both the parametric and semi-parametric approach, by the device of random effects. The work closely follows the theory developed by Lawless (1987).     

A micro computer based data base management system for a national engineering conference

A Data Base Management System for a National Engineering Conference has been developed in dBase III on an IBM XT. The system was used to record the papers and participants as they are submitted, to generate the management information data on which the scheduling and room assignments of presentations are based, and finally to print automatically the conference bulletin. The system was designed so that it could handle in excess of 2000 participants, 2000 papers and 50 simultaneous sessions.

Hardware and software requirements are defined and the selection process is reported. Techniques to design the system so that it required minimal training and is virtually user proof are illustrated. The system has been successfully used to manage the Joint ORSA/TIMS National Meeting in Atlanta, 1985 and some practical experience and possible enhancements are given.     

PREPRO: a computer program for encoding regional exploration data for use in characteristic analysis

The preprocessor (PREPRO) computer program offers the exploration geologist a variety of options for encoding regional exploration data into ternary form for use in characteristic analysis. PREPRO's options include variable-input formats, cursor input, ordering among a set of input variables, and selectable ternary transformations. Moreover, the program provides for the display of results which, in turn, makes possible review, reselection, and retransformation of variables. Most important, the performance of the listed steps in an interactive computing environment results in rapid and efficient preprocessing of the data.     

计算机云存储的数据迁移研究

云存储技术是计算机发展过程中的一项重要技术,其中数字迁移是从完全虚拟化的场景中走出来实现高度动态存储的必然条件,因此就必须对计算机云存储数据迁移进行详细的研究.     

MinGPU: a minimum GPU library for computer vision

In the field of computer vision, it is becoming increasingly popular to implement algorithms, in sections or in their entirety, on a graphics processing unit (GPU). This is due to the superior speed GPUs offer compared to CPUs. In this paper, we present a GPU library, MinGPU, which contains all of the necessary functions to convert an existing CPU code to GPU. We have created GPU implementations of several well known computer vision algorithms, including the homography transformation between two 3D views. We provide timing charts and show that our MinGPU implementation of homography transformations performs approximately 600 times faster than its C++ CPU implementation.

A computer package for measuring the strength of encryption algorithms

Designers and users of encryption algorithms used in cipher systems need a systematic approach in examining their ciphers prior to use, to ensure that they are safe from cryptanalytic attack. This paper describes a computer package used for assessing the security of newly-developed encryption algorithms.     

A note on the justification of landsat data transformations

This paper discusses the mathematical justification for Landsat data transformations. The results are based upon an atmospheric radiation transfer equation given by Turner (5). Several proposed data transformations are discussed and evaluated in light of these justifications.     

Compiling techniques for first-order linear recurrences on a vector computer

Linear recurrences are the most important class of nonvectorizable problems in typical scientific/engineering calculations. This work discusses high-performance methods for solving first-order linear recurrences on a vector computer, investigates automatic transformations, and develops compiling techniques for first-order linear recurrence problems. The results show that the improved vector code generated by the vectorizing compiler on the HITAC S-820 supercomputer runs at the rate of 150 MFLOPS (million floating operations per second) for moderate loop lengths (>1000) and over 200 MFLOPS for long loop lengths (> 10000). Also, overall performance improvements of 69% in the 14 Lawrence Livermore Loops and 25 % in the 24 Lawrence Livermore Loops, as measured by the harmonic mean, are attained.