Deduplicating Compressed Contents in Cloud Storage Environment
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). -
ACS – the Archival Cytometry Standard
http://flowcyt.sf.net/acs/latest.pdf ACS – the Archival Cytometry Standard Archival Cytometry Standard ACS International Society for Advancement of Cytometry Candidate Recommendation DRAFT Document Status The Archival Cytometry Standard (ACS) has undergone several revisions since its initial development in June 2007. The current proposal is an ISAC Candidate Recommendation Draft. It is assumed, however not guaranteed, that significant features and design aspects will remain unchanged for the final version of the Recommendation. This specification has been formally tested to comply with the W3C XML schema version 1.0 specification but no position is taken with respect to whether a particular software implementing this specification performs according to medical or other valid regulations. The work may be used under the terms of the Creative Commons Attribution-ShareAlike 3.0 Unported license. You are free to share (copy, distribute and transmit), and adapt the work under the conditions specified at http://creativecommons.org/licenses/by-sa/3.0/legalcode. Disclaimer of Liability The International Society for Advancement of Cytometry (ISAC) disclaims liability for any injury, harm, or other damage of any nature whatsoever, to persons or property, whether direct, indirect, consequential or compensatory, directly or indirectly resulting from publication, use of, or reliance on this Specification, and users of this Specification, as a condition of use, forever release ISAC from such liability and waive all claims against ISAC that may in any manner arise out of such liability. ISAC further disclaims all warranties, whether express, implied or statutory, and makes no assurances as to the accuracy or completeness of any information published in the Specification. -
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 -
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 -
Winzip 12 Reviewer's Guide
Introducing WinZip® 12 WinZip® is the most trusted way to work with compressed files. No other compression utility is as easy to use or offers the comprehensive and productivity-enhancing approach that has made WinZip the gold standard for file-compression tools. With the new WinZip 12, you can quickly and securely zip and unzip files to conserve storage space, speed up e-mail transmission, and reduce download times. State-of-the-art file compression, strong AES encryption, compatibility with more compression formats, and new intuitive photo compression, make WinZip 12 the complete compression and archiving solution. Building on the favorite features of a worldwide base of several million users, WinZip 12 adds new features for image compression and management, support for new compression methods, improved compression performance, support for additional archive formats, and more. Users can work smarter, faster, and safer with WinZip 12. Who will benefit from WinZip® 12? The simple answer is anyone who uses a PC. Any PC user can benefit from the compression and encryption features in WinZip to protect data, save space, and reduce the time to transfer files on the Internet. There are, however, some PC users to whom WinZip is an even more valuable and essential tool. Digital photo enthusiasts: As the average file size of their digital photos increases, people are looking for ways to preserve storage space on their PCs. They have lots of photos, so they are always seeking better ways to manage them. Sharing their photos is also important, so they strive to simplify the process and reduce the time of e-mailing large numbers of images. -
The Ark Handbook
The Ark Handbook Matt Johnston Henrique Pinto Ragnar Thomsen The Ark Handbook 2 Contents 1 Introduction 5 2 Using Ark 6 2.1 Opening Archives . .6 2.1.1 Archive Operations . .6 2.1.2 Archive Comments . .6 2.2 Working with Files . .7 2.2.1 Editing Files . .7 2.3 Extracting Files . .7 2.3.1 The Extract dialog . .8 2.4 Creating Archives and Adding Files . .8 2.4.1 Compression . .9 2.4.2 Password Protection . .9 2.4.3 Multi-volume Archive . 10 3 Using Ark in the Filemanager 11 4 Advanced Batch Mode 12 5 Credits and License 13 Abstract Ark is an archive manager by KDE. The Ark Handbook Chapter 1 Introduction Ark is a program for viewing, extracting, creating and modifying archives. Ark can handle vari- ous archive formats such as tar, gzip, bzip2, zip, rar, 7zip, xz, rpm, cab, deb, xar and AppImage (support for certain archive formats depends on the appropriate command-line programs being installed). In order to successfully use Ark, you need KDE Frameworks 5. The library libarchive version 3.1 or above is needed to handle most archive types, including tar, compressed tar, rpm, deb and cab archives. To handle other file formats, you need the appropriate command line programs, such as zipinfo, zip, unzip, rar, unrar, 7z, lsar, unar and lrzip. 5 The Ark Handbook Chapter 2 Using Ark 2.1 Opening Archives To open an archive in Ark, choose Open... (Ctrl+O) from the Archive menu. You can also open archive files by dragging and dropping from Dolphin. -
Bzip2 and Libbzip2, Version 1.0.8 a Program and Library for Data Compression
bzip2 and libbzip2, version 1.0.8 A program and library for data compression Julian Seward, https://sourceware.org/bzip2/ bzip2 and libbzip2, version 1.0.8: A program and library for data compression by Julian Seward Version 1.0.8 of 13 July 2019 Copyright© 1996-2019 Julian Seward This program, bzip2, the associated library libbzip2, and all documentation, are copyright © 1996-2019 Julian Seward. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: • Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. • The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. • Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. • The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS- CLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -
Windows Tips for Genealogists (Based on Windows XP)
Windows Tips for Genealogists (based on Windows XP) Experienced genealogists consider their computer to be just another tool, albeit a very expensive and powerful tool, in their bulging box of tools for helping with their research. However, if one does not know how to use all the features of such a tool, it will be seriously underutilized. This class is intended to be a basic operator’s manual of the features in Windows I find most useful for genealogists. It begins with some very basic concepts in Windows and adds some great shortcuts and things to keep in mind while doing your research. 1. Desk Top “Folder” for most often used files and programs 2. Explore (File manager) – [not to be confused with Internet Explorer] Utility program to maintain and organize the files and programs on your computer (right click on START button.- Fisheye button in Vista) Views Choose details Customize the tool bar (View>Toolbars>Customize) 3. File organization System of hierarchical folders within folders Desktop is the top folder Documents and Settings Creating folders 4. File names Naming rules (do not use < > : “ / \ | ? * . ) max length=260 Renaming Renaming multiple files 5. File extensions 3 letter codes to designate the type of file or the format of the contents of the file Be careful not to delete or change them (unless you know what you are doing) 6. File type assignments Method for assigning file types to programs Displaying file extensions My Computer>Tools>Folder Options> View>Hide Extensions Tools>Folder Options>File Types>extension>Change… 7. Read-Only flag Setting that prevents changes to the file Automatically set for non-writeable media Explore>File-name>right-click>Properties>General>Attributes>Read-only 8.