The Experts below are selected from a list of 60 Experts worldwide ranked by ideXlab platform
Diomidis Spinellis - One of the best experts on this subject based on the ideXlab platform.
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The Art and Science of Analyzing Software Data - Tools and Techniques for Analyzing Product and Process Data
The Art and Science of Analyzing Software Data, 2015Co-Authors: Diomidis SpinellisAbstract:The analysis of data from software products and their development process is tempting, but often non-trivial. A flexible, extensible, scalable, and efficient way for performing this analysis is through the use of line-oriented textual data streams, which are the lowest useful common denominator for many software analysis tasks. Using this technique, Unix Tool-chest programs are combined into a pipeline that forms the pattern: fetching, selecting, processing, and summarizing. Product artifacts that can be handled in this way include source code (using heuristics, lexical analysis, or full-blown parsing and semantic analysis) as well as compiled code, which spans assembly code, machine code, byte code, and libraries. On the process front, data that can be analyzed includes configuration management metadata, time series snapshots, and checked repositories. The resulting data can then be visualized as graphs, diagrams, charts, and maps.
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Working with Unix Tools
IEEE Software, 2005Co-Authors: Diomidis SpinellisAbstract:Line-oriented textual data streams are the lowest useful common denominator for a lot of data that passes through our hands. We can use such streams to represent program source code, Web server log data, version control history, file lists, symbol tables, archive contents, error messages, profiling data, and so on. For many routine, everyday tasks, we might be tempted to process the data using a "Swiss army knife" scripting language such as Perl, Python, or Ruby. However, doing that often requires writing a small, self-contained program and saving it into a file. By that point, we've lost interest in the task and end up doing the work manually, if at all. Often, it's more effective to combine Unix Tool chest programs into a short and sweet pipeline that we can run from our shell's command prompt. With modern shell command-line editing facilities, we can build our command bit by bit, until it molds into exactly the form that suits us. Nowadays, many different systems--including GNU/Linux, Mac OS X, and Microsoft Windows--offer the original Unix Tools, so there's no reason to not add this approach to your arsenal. Many one-liners that you'll build around the Unix Tools follow a pattern that goes roughly like this: fetching, selection, processing, and summarization. You'll also need to install some plumbing to unify these parts. This column will give you a quick overview.
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outwit Unix Tool based programming meets the windows world
USENIX Annual Technical Conference, 2000Co-Authors: Diomidis SpinellisAbstract:The ubiquity of Windows-based desktop environments has not been matched by a corresponding emergence of Tools supporting the Unix Tool composition paradigm. Outwit is a suite of Tools based on the Unix Tool design principles allowing the processing of Windows application data with sophisticated data manipulation pipelines. The outwit Tools offer access to the Windows clipboard, the registry, relational databases, document properties, and shell links. We demonstrate a number of applications of the outwit Tools used in conjuction with existing Unix commands, and discuss future directions of our work.
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USENIX Annual Technical Conference, General Track - Outwit: Unix Tool-based programming meets the windows world
2000Co-Authors: Diomidis SpinellisAbstract:The ubiquity of Windows-based desktop environments has not been matched by a corresponding emergence of Tools supporting the Unix Tool composition paradigm. Outwit is a suite of Tools based on the Unix Tool design principles allowing the processing of Windows application data with sophisticated data manipulation pipelines. The outwit Tools offer access to the Windows clipboard, the registry, relational databases, document properties, and shell links. We demonstrate a number of applications of the outwit Tools used in conjuction with existing Unix commands, and discuss future directions of our work.
John Mcbrewster - One of the best experts on this subject based on the ideXlab platform.
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lossless data compression data compression algorithm lossy compression bit rate zip file format Unix gzip portable network graphics graphics interchange format tagged image file format
2009Co-Authors: Frederic P Miller, Agnes F Vandome, John McbrewsterAbstract:Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange for better compression rates. Lossless data compression is used in many applications. For example, it is used in the popular ZIP file format and in the Unix Tool gzip. It is also often used as a component within lossy data compression technologies. Lossless compression is used when it is important that the original and the decompressed data be identical, or when no assumption can be made on whether certain deviation is uncritical. Typical examples are executable programs and source code. Some image file formats, like PNG or GIF, use only lossless compression, while others like TIFF and MNG may use either lossless or lossy methods
Geoffrey C. Bower - One of the best experts on this subject based on the ideXlab platform.
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Rapid Development of Interferometric Software Using MIRIAD and Python
Publications of the Astronomical Society of the Pacific, 2012Co-Authors: Peter K. G. Williams, Casey J. Law, Geoffrey C. BowerAbstract:New and upgraded radio interferometers produce data at massive rates and will require significant improvements in analysis techniques to reach their promised levels of performance in a routine manner. Until these techniques are fully developed, productivity and accessibility in scientific programming environments will be key bottlenecks in the pipeline leading from data-taking to research results. We present an open-source software package, miriad-python, that allows access to the MIRIAD interferometric reduction system in the Python programming language. The modular design of MIRIAD and the high productivity and accessibility of Python provide an excellent foundation for rapid development of interferometric software. Several other projects with similar goals exist and we describe them and compare miriad-python to them in detail. Along with an overview of the package design, we present sample code and applications, including the detection of millisecond astrophysical transients, determination and application of nonstandard calibration parameters, interactive data visualization, and a reduction pipeline using a directed acyclic graph dependency model analogous to that of the traditional Unix Tool "make". The key aspects of the miriad-python software project are documented. We find that miriad-python provides an extremely effective environment for prototyping new interferometric software, though certain existing packages provide far more infrastructure for some applications. While equivalent software written in compiled languages can be much faster than Python, there are many situations in which execution time is profitably exchanged for speed of development, code readability, accessibility to nonexpert programmers, quick interlinking with foreign software packages, and other virtues of the Python language.
Kenneth L. Ingham - One of the best experts on this subject based on the ideXlab platform.
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Unix Tool Building
1991Co-Authors: Kenneth L. InghamAbstract:A step-by-step guide to Tool development using existing Tools and custom-written programs, subroutines, and shell scripts. This book traces the development of an actual Tool, known as watcher, to illustrate how the principles of Tool development are applied in real-world situations. Special attention is given to "modular" strategy to reduce coding and debugging time. Finally, the book presents information on implementing and maintaining newly-developed Tools.
Linta Ann George - One of the best experts on this subject based on the ideXlab platform.
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Image Compression Techniques using Lossless Methods: A Review
Digital Image Processing, 2013Co-Authors: Chandrashekhar Kamargaonkar, Linta Ann GeorgeAbstract:In recent years there has been an astronomical increase in the usage of computers for a variety of tasks. With the advent of digital cameras, one of the most common uses has been the storage, manipulation, and transfer of digital images. The files that comprise these images, however, can be quite large and can quickly take up precious memory space on the computer’s hard drive. In multimedia application, most of the images are in colour. And colour images contain lot of data redundancy and require a large amount of storage space. Image compression algorithms offer the means to minimize storage cost and to increase transmission speed. Compressing an image is significantly different than compressing raw binary data. Of course, general purpose compression programs can be used to compress images, but the result is less than optimal. This is because images have certain statistical properties which can be exploited by encoders specifically designed for them. Also, some of the finer details in the image are sacrificed for the sake of saving a little more bandwidth or storage space. This also means that lossy compression techniques cannot be used. Hence there is a need for efficient lossless schemes for medical image data. Lossless data compression is used in many applications. For example, it is used in the ZIP file format and in the Unix Tool gzip. It is also often used as a component within lossy data compression technologies (e.g. lossless mid/side joint stereo pre-processing by the LAME MP3 encoder and other lossy audio encoders). Several lossless compression schemes have been proposed. This paper provides a comparison and brief description about the various lossless compression schemes.
