Graphical Selection of Data Views

Abstract

Graphical selection of data views is a fundamental task in interactive statistical graphics. Linked plots provide a form of indirect selection, where direct manipulation of objects displayed in one plot indirectly selects objects in other plots. A pointing device or brush is typically used for direct manipulation, and so this indirect selection is commonly known as linked brushing. Most commonly, linked brushing is applied to two or more scatterplots showing various pairs of variables from a multivariable dataset. This article describes a generalization of linked brushing for the setting where plots display different, though related datasets. With this form of linking, we can graphically explore relationships between datasets. Our linking system is extensible and handles any kind of display of any kind of dataset, as well as arbitrary relationships between those datasets.     

Automated generation of LFT-based parametric uncertainty descriptions from generic aircraft models

A computer assisted modelling methodology is developed for the generation of linearized models with parametric uncertainties described by Linear Fractional Transformations (LFTs). The starting point of the uncertainty modelling is a class of generic nonlinear aircraft models with explicit parametric dependence used for simulation purposes. The proposed methodology integrates specialized software tools for object-oriented modelling, for simulation, and for numerical as well as symbolic computations. The methodology has many generic features being applicable to similar nonlinear model classes.     

Code analysis and parallelizing vector operations in R

This paper presents some current work and preliminary thoughts on two seemingly unrelated areas. The first is the development of code analysis tools to help identify possible errors in R code. Current versions of these tools have been useful in finding bugs in R’s code as well as code in packages submitted to CRAN. The second area, where work is just beginning, is the development of mechanisms to allow R’s internal vectorized operations, as well as vectorized operations defined in packages, to take advantage of multiple processors. These two areas are related through their connections to ongoing efforts to develop a byte code compiler for R.     

付氏光谱仪中用软件取代干涉仪补偿板的研究

我们用计算机模拟实验证明,采用软件可以取代付氏光谱仪中迈氏干涉仪的补偿板,而对仪器的性能不产生任何不良影响。这一研究成果对于采用极易潮解而又比较昂贵的澳化钾,碘化铯等晶体作为补偿板的中红外付氏光谱仪具有可能的应用前景。     

On a software availability model with imperfect maintenance

In this paper we consider a general software availability model and derive compound availability measures, such as the joint probability of software availability and the remaining number of errors. The results given here generalize the results given in Kim et al. (1982).     

LOOK: A Lazy Object-Oriented Kernel design for geometric computation

In this paper we describe and discuss a new kernel design for geometric computation in the plane. It combines different kinds of floating-point filter techniques and a lazy evaluation scheme with the exact number types provided by LEDA allowing for efficient and exact computation with rational and algebraic geometric objects.

It is the first kernel design which uses floating-point filter techniques on the level of geometric constructions.

The experiments we present—partly using the CGAL framework—show a great improvement in speed and—maybe even more important for practical applications—memory consumption when dealing with more complex geometric computations.     

Cabri-géomètre: Does Dynamic Geometry Software (DGS) Change Geometry and its Teaching and Learning?

The paper starts with remarks on the author's perspective on geometry and Dynamical Geometry Software (DGS). It analyses the way DGS-use influences traditional geometry (part 2). Additionally, taking into account the user of DGS in part 3, the paper highlights changes in the interactions between geometry, the tool computer and DGS and the human user, focussing on changes in the teaching and learning of geometry. The conclusion states that DGS deeply changes geometry if it is taken as a human activity integrating the use of modern instruments like DGS.This revised version was published online in September 2005 with corrections to the Cover Date.     

基于化学计量学的通用化学数据采集处理系统

研制开发基于化学计量学的通用化学数据采集处理系统，该系统硬件采集部分，可与模拟信号输出的分析仪器或有RS－232接口的分析仪器联接进行数据采集，软件部分的数据处理基于化学计量学理论知识，相应数据处理方法，可从采集到数据中获取大量的信息。软件部分的信息管理包含了大量实验要素的归整、查询和统计等。     

一种软启停正负双直流电源的设计

变形镜驱动器正负电源加电或者断电不同步,导致其在加电瞬间或者断电瞬间,输出端会输出一个-38.0V和86.0V的冲击电压,这个冲击电压使得变形镜在未开始工作时就产生了较为严重的面形畸变,为此研制了基于微处理器的软启停直流电源,它输出两路按一定时序变化的输出电压作为后续两个继电器的控制端,再通过这两个继电器分别控制变形镜驱动器正、负电源的导断,从而使得变形镜驱动器的正负电源同时加载或者卸载。在硬件平台了进行了实验验证,结果表明,使用软启停直流电源后,变形镜驱动器加电瞬间或断电瞬间,其产生的脉冲电压的峰-峰不超过0.45V,远远小于未使用软启停直流电源前的冲击电压,满足了系统的设计要求。     

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介绍了一种软X射线多道能谱测量的新方法,该方法用软件实现实时采集、数据处理并通过软X射线能谱计算及时显示电子温度。和传统的脉高分析器(PHA)相比,道数和时间分辨率可用软件设定。新方法采用一台配有高速A/D采集卡的个人计算机获取原始的模拟信号,开发了专用的处理软件用来处理电子温度。新方法已经应用于HL-2A装置实验,与其它方法测到的电子温度具有较好的一致性。