28,907 research outputs found

    Implementing spatial segregation measures in R.

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    Reliable and accurate estimation of residential segregation between population groups is important for understanding the extent of social cohesion and integration in our society. Although there have been considerable methodological advances in the measurement of segregation over the last several decades, the recently developed measures have not been widely used in the literature, in part due to their complex calculation. To address this problem, we have implemented several newly proposed segregation indices in R, an open source software environment for statistical computing and graphics, as a package called seg. Although there are already a few standalone applications and add-on packages that provide access to similar methods, our implementation has a number of advantages over the existing tools. First, our implementation is flexible in the sense that it provides detailed control over the calculation process with a wide range of input parameters. Most of the parameters have carefully chosen defaults, which perform acceptably in many situations, so less experienced users can also use the implemented functions without too much difficulty. Second, there is no need to export results to other software programs for further analysis. We provide coercion methods that enable the transformation of our output classes into general R classes, so the user can use thousands of standard and modern statistical techniques, which are already available in R, for the post-processing of the results. Third, our implementation does not require commercial software to operate, so it is accessible to a wider group of people

    DEAN: A program for dynamic engine analysis

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    The Dynamic Engine Analysis program, DEAN, is a FORTRAN code implemented on the IBM/370 mainframe at NASA Lewis Research Center for digital simulation of turbofan engine dynamics. DEAN is an interactive program which allows the user to simulate engine subsystems as well as a full engine systems with relative ease. The nonlinear first order ordinary differential equations which define the engine model may be solved by one of four integration schemes, a second order Runge-Kutta, a fourth order Runge-Kutta, an Adams Predictor-Corrector, or Gear's method for still systems. The numerical data generated by the model equations are displayed at specified intervals between which the user may choose to modify various parameters affecting the model equations and transient execution. Following the transient run, versatile graphics capabilities allow close examination of the data. DEAN's modeling procedure and capabilities are demonstrated by generating a model of simple compressor rig

    MIDAS, prototype Multivariate Interactive Digital Analysis System for large area earth resources surveys. Volume 1: System description

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    A third-generation, fast, low cost, multispectral recognition system (MIDAS) able to keep pace with the large quantity and high rates of data acquisition from large regions with present and projected sensots is described. The program can process a complete ERTS frame in forty seconds and provide a color map of sixteen constituent categories in a few minutes. A principle objective of the MIDAS program is to provide a system well interfaced with the human operator and thus to obtain large overall reductions in turn-around time and significant gains in throughput. The hardware and software generated in the overall program is described. The system contains a midi-computer to control the various high speed processing elements in the data path, a preprocessor to condition data, and a classifier which implements an all digital prototype multivariate Gaussian maximum likelihood or a Bayesian decision algorithm. Sufficient software was developed to perform signature extraction, control the preprocessor, compute classifier coefficients, control the classifier operation, operate the color display and printer, and diagnose operation

    Current and future graphics requirements for LaRC and proposed future graphics system

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    The findings of an investigation to assess the current and future graphics requirements of the LaRC researchers with respect to both hardware and software are presented. A graphics system designed to meet these requirements is proposed

    The engineering design integration (EDIN) system

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    A digital computer program complex for the evaluation of aerospace vehicle preliminary designs is described. The system consists of a Univac 1100 series computer and peripherals using the Exec 8 operating system, a set of demand access terminals of the alphanumeric and graphics types, and a library of independent computer programs. Modification of the partial run streams, data base maintenance and construction, and control of program sequencing are provided by a data manipulation program called the DLG processor. The executive control of library program execution is performed by the Univac Exec 8 operating system through a user established run stream. A combination of demand and batch operations is employed in the evaluation of preliminary designs. Applications accomplished with the EDIN system are described

    Sixth Annual Users' Conference

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    Conference papers and presentation outlines which address the use of the Transportable Applications Executive (TAE) and its various applications programs are compiled. Emphasis is given to the design of the user interface and image processing workstation in general. Alternate ports of TAE and TAE subsystems are also covered

    GENtle, a free multi-purpose molecular biology tool

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    A result of modern techniques in molecular biology, especially DNA sequencing, is the exponentially growing amount of available data. Besides giant, specialized databases, which are accessible over the Internet, all work groups in the field of molecular biology today need to handle, modify, analyze and store sequence information. This trend notwithstanding, general purpose software for these tasks often suffers from severe drawbacks. Free software exists, but is often hard to set up and operate for users on today's point-and-click interfaces, and usually leads to the application of a patch-work of multiple, only partially compatible tools and web services. Commercial software often covers only parts of the required functions, and tends to lock the user into proprietary formats. In my thesis, I have developed GENtle, a free, multi-purpose bioinformatics software, seamlessly integrating diverse applications for every-day lab use in a single package. It was designed for easy and intuitive use, while providing many powerful functions. This C++ application runs on multiple platforms, is optimized for performance, and includes database interfaces for easy sequence management. It features DNA and protein sequence management and analysis, virtual cloning, gels, and PCR, primer design, alignment generation and layout, chromatogram and image display, as well as many related functions. GENtle strives to satisfy the need for an easy and comfortable, yet powerful multi-purpose tool. One design goal of GENtle was "instant responsiveness". Likewise, consistent display and handling are of great importance. GENtle has been outfitted with modules for DNA and protein sequence management, editing, and analysis, primer design, virtual PCR, alignments, virtual gels, a plethora of import and export formats, integrated database management, internet search functionality, an auto-update mechanism, and a number of integrated tools. GENtle is free software licensed under the GPL and available for Windows, Mac OSX, and Linux in several languages. As such, it is already in use in research groups worldwide
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