I ve written some many years ago dynamic Huffman algorithm to compress and decompress data. It is mainly targeted to data with some symbols occuring more often than the rest (e.g. having some data file consisted of 3 different symbols and their total number of occurence in that file s1(1000), s2(200), s3(30) so the total length of file is 1000+200+30=1230 bytes, it will be encoded assigning one bit to s1 and 2 bits to s2, s3 so the encoded length will be 1*1000+2*(200+30)=1460 bits=182 bytes). In the best case the file consisted of just one symbol will be encoded with compression ratio as 1:8. Huffman coding is used in image compression, however in JPEG2000 arithmetic codec is imployed.
标签： decompress algorithm compress Huffman
上传时间： 2016-05-16
上传用户：aysyzxzm
Data mining (DM) is the extraction of hidden predictive information from large databases (DBs). With the automatic discovery of knowledge implicit within DBs, DM uses sophisticated statistical analysis and modeling techniques to uncover patterns and relationships hidden in organizational DBs. Over the last 40 years, the tools and techniques to process structured information have continued to evolve from DBs to data warehousing (DW) to DM. DW applications have become business-critical. DM can extract even more value out of these huge repositories of information.
标签： information extraction predictive databases
上传时间： 2016-03-19
上传用户：啊飒飒大师的
The SL74HC573 is identical in pinout to the LS/ALS573. The device inputs are compatible with standard CMOS outputs with pullup resistors, they are compatible with LS/ALSTTL outputs. These latches appear transparent to data (i.e., the outputs change asynchronously) when Latch Enable is high. When Latch Enable goes low, data meeting the setup and hold time becomes latched.
标签： compatible The 573 identical
上传时间： 2016-12-29
上传用户：变形金刚
This guide explains how data networks operate, why data systems are becoming more complicated, and how data networks are changing to permit broadband services and applications. Table of Contents Introduction To Data Networks—PDN, LAN, MAN, WAN, and Wireless Data, Technologies and Systems Data Networks List of Figures
标签： data complicated explains becoming
上传时间： 2017-09-26
上传用户：邶刖
Smart Grids provide many benefits for society. Reliability, observability across the energy distribution system and the exchange of information between devices are just some of the features that make Smart Grids so attractive. One of the main products of a Smart Grid is to data. The amount of data available nowadays increases fast and carries several kinds of information. Smart metres allow engineers to perform multiple measurements and analyse such data. For example, information about consumption, power quality and digital protection, among others, can be extracted. However, the main challenge in extracting information from data arises from the data quality. In fact, many sectors of the society can benefit from such data. Hence, this information needs to be properly stored and readily available. In this chapter, we will address the main concepts involving Technology Information, Data Mining, Big Data and clustering for deploying information on Smart Grids.
标签： Processing Cities Smart Data in
上传时间： 2020-05-23
上传用户：shancjb
Smart Grids provide many benefits for society. Reliability, observability across the energy distribution system and the exchange of information between devices are just some of the features that make Smart Grids so attractive. One of the main products of a Smart Grid is to data. The amount of data available nowadays increases fast and carries several kinds of information. Smart metres allow engineers to perform multiple measurements and analyse such data. For example, information about consumption, power quality and digital protection, among others, can be extracted. However, the main challenge in extracting information from data arises from the data quality. In fact, many sectors of the society can benefit from such data. Hence, this information needs to be properly stored and readily available. In this chapter, we will address the main concepts involving Technology Information, Data Mining, Big Data and clustering for deploying information on Smart Grids.
标签： Processing Cities Smart Data
上传时间： 2020-05-25
上传用户：shancjb
LemonSMS is a component developed in Java that provides a turnkey solution for application developers to incorporate into their Java applications the functionality of sending and processing of incoming SMS messages. LemonSMS acts as a middleware between a Java application and a GSM Modem or Data enabled phone. Because LemonSMS only provides an interface to the added SMS functionality, your application still handles access to data and business logic tier. With the easy-to-use LemonSMS API, developers can easily utilize SMS functionalities provided by LemonSMS.
标签： application component developed developer
上传时间： 2013-12-29
上传用户：大融融rr
SQL Server Security Distilled, Second Edition by Morris Lewis ISBN:1590592190 Apress © 2004 (352 pages) This book takes an in-depth look at what you can do to secure data in SQL Server, shows how to authenticate access to data on the server, and authorizes what users can and can t do with that data, in versions 6.5, 7.0, and 2000.
标签： 1590592190 Distilled Security Edition
上传时间： 2015-12-25
上传用户：hj_18
This project aim was to build wireless software modem for data communication between two computers using an acoustic interface in the voice frequency range (20Hz– 20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz – 20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz – 16,000Hz). The test files used as information files were text files. This goal was attained both in an incoherent scheme and in a coherent scheme. Build under Matlab code, our modem uses OFDM (orthogonal frequency division multiplexing) modulation, synchronization by LMS sequence, channel estimation (no equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of 2 or 4. To optimize the probability of error, these symbols were mapped using Gray mapping. Report
标签： communication computers software wireless
上传时间： 2014-05-29
上传用户：wangdean1101
Can convert data file(txt format)to CAD(scr)file,and draw curve!
上传时间： 2013-09-11
上传用户：天空说我在
