The Ark Handbook
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Data Preparation & Descriptive Statistics
Data Preparation & Descriptive Statistics (ver. 2.4) Oscar Torres-Reyna Data Consultant [email protected] PU/DSS/OTR http://dss.princeton.edu/training/ Basic definitions… For statistical analysis we think of data as a collection of different pieces of information or facts. These pieces of information are called variables. A variable is an identifiable piece of data containing one or more values. Those values can take the form of a number or text (which could be converted into number) In the table below variables var1 thru var5 are a collection of seven values, ‘id’ is the identifier for each observation. This dataset has information for seven cases (in this case people, but could also be states, countries, etc) grouped into five variables. id var1 var2 var3 var4 var5 1 7.3 32.27 0.1 Yes Male 2 8.28 40.68 0.56 No Female 3 3.35 5.62 0.55 Yes Female 4 4.08 62.8 0.83 Yes Male 5 9.09 22.76 0.26 No Female 6 8.15 90.85 0.23 Yes Female 7 7.59 54.94 0.42 Yes Male PU/DSS/OTR Data structure… For data analysis your data should have variables as columns and observations as rows. The first row should have the column headings. Make sure your dataset has at least one identifier (for example, individual id, family id, etc.) id var1 var2 var3 var4 var5 First row should have the variable names 1 7.3 32.27 0.1 Yes Male 2 8.28 40.68 0.56 No Female Cross-sectional data 3 3.35 5.62 0.55 Yes Female 4 4.08 62.8 0.83 Yes Male 5 9.09 22.76 0.26 No Female 6 8.15 90.85 0.23 Yes Female 7 7.59 54.94 0.42 Yes Male id year var1 var2 var3 1 2000 7 74.03 0.55 Group 1 1 2001 2 4.6 0.44 At least one identifier 1 2002 2 25.56 0.77 2 2000 7 59.52 0.05 Cross-sectional time series data Group 2 2 2001 2 16.95 0.94 or panel data 2 2002 9 1.2 0.08 3 2000 9 85.85 0.5 Group 3 3 2001 3 98.85 0.32 3 2002 3 69.2 0.76 PU/DSS/OTR NOTE: See: http://www.statistics.com/resources/glossary/c/crossdat.php Data format (ASCII)… ASCII (American Standard Code for Information Interchange). -
Contrasting the Performance of Compression Algorithms on Genomic Data
Contrasting the Performance of Compression Algorithms on Genomic Data Cornel Constantinescu, IBM Research Almaden Outline of the Talk: • Introduction / Motivation • Data used in experiments • General purpose compressors comparison • Simple Improvements • Special purpose compression • Transparent compression – working on compressed data (prototype) • Parallelism / Multithreading • Conclusion Introduction / Motivation • Despite the large number of research papers and compression algorithms proposed for compressing genomic data generated by sequencing machines, by far the most commonly used compression algorithm in the industry for FASTQ data is gzip. • The main drawbacks of the proposed alternative special-purpose compression algorithms are: • slow speed of either compression or decompression or both, and also their • brittleness by making various limiting assumptions about the input FASTQ format (for example, the structure of the headers or fixed lengths of the records [1]) in order to further improve their specialized compression. 1. Ibrahim Numanagic, James K Bonfield, Faraz Hach, Jan Voges, Jorn Ostermann, Claudio Alberti, Marco Mattavelli, and S Cenk Sahinalp. Comparison of high-throughput sequencing data compression tools. Nature Methods, 13(12):1005–1008, October 2016. Fast and Efficient Compression of Next Generation Sequencing Data 2 2 General Purpose Compression of Genomic Data As stated earlier, gzip/zlib compression is the method of choice by the industry for FASTQ genomic data. FASTQ genomic data is a text-based format (ASCII readable text) for storing a biological sequence and the corresponding quality scores. Each sequence letter and quality score is encoded with a single ASCII character. FASTQ data is structured in four fields per record (a “read”). The first field is the SEQUENCE ID or the header of the read. -
Full Document
R&D Centre for Mobile Applications (RDC) FEE, Dept of Telecommunications Engineering Czech Technical University in Prague RDC Technical Report TR-13-4 Internship report Evaluation of Compressibility of the Output of the Information-Concealing Algorithm Julien Mamelli, [email protected] 2nd year student at the Ecole´ des Mines d'Al`es (N^ımes,France) Internship supervisor: Luk´aˇsKencl, [email protected] August 2013 Abstract Compression is a key element to exchange files over the Internet. By generating re- dundancies, the concealing algorithm proposed by Kencl and Loebl [?], appears at first glance to be particularly designed to be combined with a compression scheme [?]. Is the output of the concealing algorithm actually compressible? We have tried 16 compression techniques on 1 120 files, and the result is that we have not found a solution which could advantageously use repetitions of the concealing method. Acknowledgments I would like to express my gratitude to my supervisor, Dr Luk´aˇsKencl, for his guidance and expertise throughout the course of this work. I would like to thank Prof. Robert Beˇst´akand Mr Pierre Runtz, for giving me the opportunity to carry out my internship at the Czech Technical University in Prague. I would also like to thank all the members of the Research and Development Center for Mobile Applications as well as my colleagues for the assistance they have given me during this period. 1 Contents 1 Introduction 3 2 Related Work 4 2.1 Information concealing method . 4 2.2 Archive formats . 5 2.3 Compression algorithms . 5 2.3.1 Lempel-Ziv algorithm . -
The Basic Principles of Data Compression
The Basic Principles of Data Compression Author: Conrad Chung, 2BrightSparks Introduction Internet users who download or upload files from/to the web, or use email to send or receive attachments will most likely have encountered files in compressed format. In this topic we will cover how compression works, the advantages and disadvantages of compression, as well as types of compression. What is Compression? Compression is the process of encoding data more efficiently to achieve a reduction in file size. One type of compression available is referred to as lossless compression. This means the compressed file will be restored exactly to its original state with no loss of data during the decompression process. This is essential to data compression as the file would be corrupted and unusable should data be lost. Another compression category which will not be covered in this article is “lossy” compression often used in multimedia files for music and images and where data is discarded. Lossless compression algorithms use statistic modeling techniques to reduce repetitive information in a file. Some of the methods may include removal of spacing characters, representing a string of repeated characters with a single character or replacing recurring characters with smaller bit sequences. Advantages/Disadvantages of Compression Compression of files offer many advantages. When compressed, the quantity of bits used to store the information is reduced. Files that are smaller in size will result in shorter transmission times when they are transferred on the Internet. Compressed files also take up less storage space. File compression can zip up several small files into a single file for more convenient email transmission. -
Encryption Introduction to Using 7-Zip
IT Services Training Guide Encryption Introduction to using 7-Zip It Services Training Team The University of Manchester email: [email protected] www.itservices.manchester.ac.uk/trainingcourses/coursesforstaff Version: 5.3 Training Guide Introduction to Using 7-Zip Page 2 IT Services Training Introduction to Using 7-Zip Table of Contents Contents Introduction ......................................................................................................................... 4 Compress/encrypt individual files ....................................................................................... 5 Email compressed/encrypted files ....................................................................................... 8 Decrypt an encrypted file ..................................................................................................... 9 Create a self-extracting encrypted file .............................................................................. 10 Decrypt/un-zip a file .......................................................................................................... 14 APPENDIX A Downloading and installing 7-Zip ................................................................. 15 Help and Further Reference ............................................................................................... 18 Page 3 Training Guide Introduction to Using 7-Zip Introduction 7-Zip is an application that allows you to: Compress a file – for example a file that is 5MB can be compressed to 3MB Secure the -
Pack, Encrypt, Authenticate Document Revision: 2021 05 02
PEA Pack, Encrypt, Authenticate Document revision: 2021 05 02 Author: Giorgio Tani Translation: Giorgio Tani This document refers to: PEA file format specification version 1 revision 3 (1.3); PEA file format specification version 2.0; PEA 1.01 executable implementation; Present documentation is released under GNU GFDL License. PEA executable implementation is released under GNU LGPL License; please note that all units provided by the Author are released under LGPL, while Wolfgang Ehrhardt’s crypto library units used in PEA are released under zlib/libpng License. PEA file format and PCOMPRESS specifications are hereby released under PUBLIC DOMAIN: the Author neither has, nor is aware of, any patents or pending patents relevant to this technology and do not intend to apply for any patents covering it. As far as the Author knows, PEA file format in all of it’s parts is free and unencumbered for all uses. Pea is on PeaZip project official site: https://peazip.github.io , https://peazip.org , and https://peazip.sourceforge.io For more information about the licenses: GNU GFDL License, see http://www.gnu.org/licenses/fdl.txt GNU LGPL License, see http://www.gnu.org/licenses/lgpl.txt 1 Content: Section 1: PEA file format ..3 Description ..3 PEA 1.3 file format details ..5 Differences between 1.3 and older revisions ..5 PEA 2.0 file format details ..7 PEA file format’s and implementation’s limitations ..8 PCOMPRESS compression scheme ..9 Algorithms used in PEA format ..9 PEA security model .10 Cryptanalysis of PEA format .12 Data recovery from -
Steganography and Vulnerabilities in Popular Archives Formats.| Nyxengine Nyx.Reversinglabs.Com
Hiding in the Familiar: Steganography and Vulnerabilities in Popular Archives Formats.| NyxEngine nyx.reversinglabs.com Contents Introduction to NyxEngine ............................................................................................................................ 3 Introduction to ZIP file format ...................................................................................................................... 4 Introduction to steganography in ZIP archives ............................................................................................. 5 Steganography and file malformation security impacts ............................................................................... 8 References and tools .................................................................................................................................... 9 2 Introduction to NyxEngine Steganography1 is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. When it comes to digital steganography no stone should be left unturned in the search for viable hidden data. Although digital steganography is commonly used to hide data inside multimedia files, a similar approach can be used to hide data in archives as well. Steganography imposes the following data hiding rule: Data must be hidden in such a fashion that the user has no clue about the hidden message or file's existence. This can be achieved by -
Improved Neural Network Based General-Purpose Lossless Compression Mohit Goyal, Kedar Tatwawadi, Shubham Chandak, Idoia Ochoa
JOURNAL OF LATEX CLASS FILES, VOL. 14, NO. 8, AUGUST 2015 1 DZip: improved neural network based general-purpose lossless compression Mohit Goyal, Kedar Tatwawadi, Shubham Chandak, Idoia Ochoa Abstract—We consider lossless compression based on statistical [4], [5] and generative modeling [6]). Neural network based data modeling followed by prediction-based encoding, where an models can typically learn highly complex patterns in the data accurate statistical model for the input data leads to substantial much better than traditional finite context and Markov models, improvements in compression. We propose DZip, a general- purpose compressor for sequential data that exploits the well- leading to significantly lower prediction error (measured as known modeling capabilities of neural networks (NNs) for pre- log-loss or perplexity [4]). This has led to the development of diction, followed by arithmetic coding. DZip uses a novel hybrid several compressors using neural networks as predictors [7]– architecture based on adaptive and semi-adaptive training. Unlike [9], including the recently proposed LSTM-Compress [10], most NN based compressors, DZip does not require additional NNCP [11] and DecMac [12]. Most of the previous works, training data and is not restricted to specific data types. The proposed compressor outperforms general-purpose compressors however, have been tailored for compression of certain data such as Gzip (29% size reduction on average) and 7zip (12% size types (e.g., text [12] [13] or images [14], [15]), where the reduction on average) on a variety of real datasets, achieves near- prediction model is trained in a supervised framework on optimal compression on synthetic datasets, and performs close to separate training data or the model architecture is tuned for specialized compressors for large sequence lengths, without any the specific data type. -
My Sons Postponed to March 18-19 Artist Series Please: Return Those Books!
» LWA Darlings Don Colonial Garb for Minuet Ans^nsçhuetz, Bekkdal, Jensen and Ladw ig Lib*.Ire Honored at Traditional Banquet A dainty Mozart minuet intro-1 duced Lawrence college’s four Best tian. president of the Spanish Loved senior women at the annual club. « colonial banquet last Monday eve Tekla Bekkedal as vice-president ning in the dining hall of the First of the Student Christian association, Congregational church. Chosen for the Best Loved honor this year and is active in the International were Mary Anschuetz, Tekla Bek- Relations club, the German club kedal, Mary Ellen Jensen and Joan tind on The Lawrentian staff. She Ladwig. Complete with powdered wras chosen for membership in hair, they were dressed in tradi Sigrna, underclass scholastic group, tional colonial costumes of George and is now a counselor to freshman and Martha Washington and James women. and Dolly Madison. Miss Jensen is yico-president and The best loved tradition, which Pled*e mistress of Alpha Chi Ome- has been observed for more than 20 *?a- ^lcr social sorority, and also is years, is sponsored by the Lawrencei^fHiated w'ith Sigma Alpha Iota, Women’s association, under the so- professional music sorority. A music Cial chairmanship this year of Viv- major, she sings in the college con- ia n Grady and Betty Wheeler. V iv - cert choir and plays in several in- ia n was toastmistress for the ban- strumental groups. Last fall she was quet and Mrs. Kenneth Davis, Ap-¡chosen attendant to the homecom- pleton. a Best Loved in 1947, gave ¡ ‘ " 8 queen and she has also served a toast to the new electees and pre- as a counselor to freshman women, tented them with small bracelets on! Best Loved banquets are not behalf of last year’s group. -
Lossless Compression of Internal Files in Parallel Reservoir Simulation
Lossless Compression of Internal Files in Parallel Reservoir Simulation Suha Kayum Marcin Rogowski Florian Mannuss 9/26/2019 Outline • I/O Challenges in Reservoir Simulation • Evaluation of Compression Algorithms on Reservoir Simulation Data • Real-world application - Constraints - Algorithm - Results • Conclusions 2 Challenge Reservoir simulation 1 3 Reservoir Simulation • Largest field in the world are represented as 50 million – 1 billion grid block models • Each runs takes hours on 500-5000 cores • Calibrating the model requires 100s of runs and sophisticated methods • “History matched” model is only a beginning 4 Files in Reservoir Simulation • Internal Files • Input / Output Files - Interact with pre- & post-processing tools Date Restart/Checkpoint Files 5 Reservoir Simulation in Saudi Aramco • 100’000+ simulations annually • The largest simulation of 10 billion cells • Currently multiple machines in TOP500 • Petabytes of storage required 600x • Resources are Finite • File Compression is one solution 50x 6 Compression algorithm evaluation 2 7 Compression ratio Tested a number of algorithms on a GRID restart file for two models 4 - Model A – 77.3 million active grid blocks 3.5 - Model K – 8.7 million active grid blocks 3 - 15.6 GB and 7.2 GB respectively 2.5 2 Compression ratio is between 1.5 1 compression ratio compression - From 2.27 for snappy (Model A) 0.5 0 - Up to 3.5 for bzip2 -9 (Model K) Model A Model K lz4 snappy gzip -1 gzip -9 bzip2 -1 bzip2 -9 8 Compression speed • LZ4 and Snappy significantly outperformed other algorithms -
![User Commands GZIP ( 1 ) Gzip, Gunzip, Gzcat – Compress Or Expand Files Gzip [ –Acdfhllnnrtvv19 ] [–S Suffix] [ Name ... ]](https://docslib.b-cdn.net/cover/1609/user-commands-gzip-1-gzip-gunzip-gzcat-compress-or-expand-files-gzip-acdfhllnnrtvv19-s-suffix-name-561609.webp)
User Commands GZIP ( 1 ) Gzip, Gunzip, Gzcat – Compress Or Expand Files Gzip [ –Acdfhllnnrtvv19 ] [–S Suffix] [ Name ... ]
User Commands GZIP ( 1 ) NAME gzip, gunzip, gzcat – compress or expand files SYNOPSIS gzip [–acdfhlLnNrtvV19 ] [– S suffix] [ name ... ] gunzip [–acfhlLnNrtvV ] [– S suffix] [ name ... ] gzcat [–fhLV ] [ name ... ] DESCRIPTION Gzip reduces the size of the named files using Lempel-Ziv coding (LZ77). Whenever possible, each file is replaced by one with the extension .gz, while keeping the same ownership modes, access and modification times. (The default extension is – gz for VMS, z for MSDOS, OS/2 FAT, Windows NT FAT and Atari.) If no files are specified, or if a file name is "-", the standard input is compressed to the standard output. Gzip will only attempt to compress regular files. In particular, it will ignore symbolic links. If the compressed file name is too long for its file system, gzip truncates it. Gzip attempts to truncate only the parts of the file name longer than 3 characters. (A part is delimited by dots.) If the name con- sists of small parts only, the longest parts are truncated. For example, if file names are limited to 14 characters, gzip.msdos.exe is compressed to gzi.msd.exe.gz. Names are not truncated on systems which do not have a limit on file name length. By default, gzip keeps the original file name and timestamp in the compressed file. These are used when decompressing the file with the – N option. This is useful when the compressed file name was truncated or when the time stamp was not preserved after a file transfer. Compressed files can be restored to their original form using gzip -d or gunzip or gzcat. -
Software to Extract Cab Files
Software to extract cab files click here to download You can use WinZip to extract CAB files by following the steps listed below. file extension associated with WinZip program, just double-click on the file. PeaZip offers read-only support (open and extract cab files) for Microsoft Cabinet file format, providing a free alternative utility to open (list content) and www.doorway.ru packages, or disassemble single files from the container, under Windows and Linux operating systems. Moreover, the OS can create, extract, or rebuild cab files. This means you do not require any additional third-party software for this task. All CAB. For a number of years, Microsoft has www.doorway.ru files to compress software that was distributed on disks. Originally, these files were used to minimize the number . The InstallShield installer program makes files with the CAB However, you can also open or extract CAB files with a file decompression tool. Open, browse, extract, or view Microsoft CAB files with Altap Salamander File Manager. High quality software with emphasis on error states. Affordable cost: . Microsoft uses cab files to package software programs. You can view the contents of a cab file by unzipping it and extracting its contents to a. Hi, I need some help www.doorway.ru files. I have to extract a patch for one game, so i used universal extractor for to extract www.doorway.ru Now I have to. cab Extension - List of programs that can www.doorway.ru files. www.doorway.ru, Inventoria Stock Manager, NCH Software, Extract with Express Zip, Low.