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Data Extraction
Data extraction is the act or process of retrieving data out of (usually unstructured or poorly structured) data sources for further data processing or data storage (data migration). The import into the intermediate extracting system is thus usually followed by data transformation and possibly the addition of metadata prior to export to another stage in the data workflow. Usually, the term data extraction is applied when (experimental) data is first imported into a computer from primary sources, like measuring or recording devices. Today's electronic devices will usually present an electrical connector (e.g. USB) through which 'raw data' can be streamed into a personal computer. Data sources Typical unstructured data sources include web pages, emails, documents, PDFs, social media, scanned text, mainframe reports, spool files, multimedia files, etc. Extracting data from these unstructured sources has grown into a considerable technical challenge, where as historically data extra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Data
Data ( , ) are a collection of discrete or continuous values that convey information, describing the quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted formally. A datum is an individual value in a collection of data. Data are usually organized into structures such as tables that provide additional context and meaning, and may themselves be used as data in larger structures. Data may be used as variables in a computational process. Data may represent abstract ideas or concrete measurements. Data are commonly used in scientific research, economics, and virtually every other form of human organizational activity. Examples of data sets include price indices (such as the consumer price index), unemployment rates, literacy rates, and census data. In this context, data represent the raw facts and figures from which useful information can be extracted. Data are collected using technique ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Raw Data
Raw data, also known as primary data, are ''data'' (e.g., numbers, instrument readings, figures, etc.) collected from a source. In the context of examinations, the raw data might be described as a raw score (after test scores). If a scientist sets up a computerized thermometer which records the temperature of a chemical mixture in a test tube every minute, the list of temperature readings for every minute, as printed out on a spreadsheet or viewed on a computer screen are "raw data". Raw data have not been subjected to processing, "cleaning" by researchers to remove outliers, obvious instrument reading errors or data entry errors, or any analysis (e.g., determining central tendency aspects such as the average or median result). As well, raw data have not been subject to any other manipulation by a software program or a human researcher, analyst or technician. They are also referred to as ''primary'' data. Raw data is a relative term (see data), because even once raw data have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Extract, Transform, Load
Extract, transform, load (ETL) is a three-phase computing process where data is ''extracted'' from an input source, ''transformed'' (including cleaning), and ''loaded'' into an output data container. The data can be collected from one or more sources and it can also be output to one or more destinations. ETL processing is typically executed using software applications but it can also be done manually by system operators. ETL software typically automates the entire process and can be run manually or on recurring schedules either as single jobs or aggregated into a batch of jobs. A properly designed ETL system extracts data from source systems and enforces data type and data validity standards and ensures it conforms structurally to the requirements of the output. Some ETL systems can also deliver data in a presentation-ready format so that application developers can build applications and end users can make decisions. The ETL process is often used in data warehousing. ETL sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Data Retrieval
Data retrieval means obtaining data from a database management system (DBMS), like for example an object-oriented database (ODBMS). In this case, it is considered that data is represented in a structured way, and there is no ambiguity in data. In order to retrieve the desired data the user presents a set of criteria by a query. Then the database management system selects the demanded data from the database. The retrieved data may be stored in a file, printed, or viewed on the screen. A query language, like for example Structured Query Language (SQL), is used to prepare the queries. SQL is an American National Standards Institute (ANSI) standardized query language developed specifically to write database queries. Each database management system may have its own language, but most are relational. How the data is presented Reports and queries are the two primary forms of the retrieved data from a database. There are some overlaps between them, but queries generally select a rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Data Mining
Data mining is the process of extracting and finding patterns in massive data sets involving methods at the intersection of machine learning, statistics, and database systems. Data mining is an interdisciplinary subfield of computer science and statistics with an overall goal of extracting information (with intelligent methods) from a data set and transforming the information into a comprehensible structure for further use. Data mining is the analysis step of the " knowledge discovery in databases" process, or KDD. Aside from the raw analysis step, it also involves database and data management aspects, data pre-processing, model and inference considerations, interestingness metrics, complexity considerations, post-processing of discovered structures, visualization, and online updating. The term "data mining" is a misnomer because the goal is the extraction of patterns and knowledge from large amounts of data, not the extraction (''mining'') of data itself. It also is a buzzwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Text Analytics
Text mining, text data mining (TDM) or text analytics is the process of deriving high-quality information from plain text, text. It involves "the discovery by computer of new, previously unknown information, by automatically extracting information from different written resources." Written resources may include websites, books, emails, reviews, and articles. High-quality information is typically obtained by devising patterns and trends by means such as pattern recognition, statistical pattern learning. According to Hotho et al. (2005), there are three perspectives of text mining: information extraction, data mining, and knowledge discovery in databases (KDD). Text mining usually involves the process of structuring the input text (usually parsing, along with the addition of some derived linguistic features and the removal of others, and subsequent insertion into a database), deriving patterns within the structured data, and finally evaluation and interpretation of the output. 'High qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Regular Expression
A regular expression (shortened as regex or regexp), sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory. The concept of regular expressions began in the 1950s, when the American mathematician Stephen Cole Kleene formalized the concept of a regular language. They came into common use with Unix text-processing utilities. Different syntaxes for writing regular expressions have existed since the 1980s, one being the POSIX standard and another, widely used, being the Perl syntax. Regular expressions are used in search engines, in search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK, and in lexical analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Pattern Matching
In computer science, pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually must be exact: "either it will or will not be a match." The patterns generally have the form of either sequences or tree structures. Uses of pattern matching include outputting the locations (if any) of a pattern within a token sequence, to output some component of the matched pattern, and to substitute the matching pattern with some other token sequence (i.e., search and replace). Sequence patterns (e.g., a text string) are often described using regular expressions and matched using techniques such as backtracking. Tree patterns are used in some programming languages as a general tool to process data based on its structure, e.g. C#, F#, Haskell, Java, ML, Python, Ruby, Rust, Scala, Swift and the symbolic mathematics language Mathematica have special syntax for expressing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Web Scraping
Web scraping, web harvesting, or web data extraction is data scraping used for data extraction, extracting data from websites. Web scraping software may directly access the World Wide Web using the Hypertext Transfer Protocol or a web browser. While web scraping can be done manually by a software user, the term typically refers to automated processes implemented using a Internet bot, bot or web crawler. It is a form of copying in which specific data is gathered and copied from the web, typically into a central local database or spreadsheet, for later data retrieval, retrieval or data analysis, analysis. Scraping a web page involves fetching it and then extracting data from it. Fetching is the downloading of a page (which a browser does when a user views a page). Therefore, web crawling is a main component of web scraping, to fetch pages for later processing. Having fetched, extraction can take place. The content of a page may be Parsing, parsed, searched and reformatted, and its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Email
Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the late–20th century as the digital version of, or counterpart to, mail (hence ''wikt:e-#Etymology 2, e- + mail''). Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries. Email operates across computer networks, primarily the Internet access, Internet, and also local area networks. Today's email systems are based on a store-and-forward model. Email Server (computing), servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect, ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Web Page
A web page (or webpage) is a World Wide Web, Web document that is accessed in a web browser. A website typically consists of many web pages hyperlink, linked together under a common domain name. The term "web page" is therefore a metaphor of paper pages bound together into a book. Navigation Each web page is identified by a distinct URL, Uniform Resource Locator (URL). When the user inputs a URL into their web browser, the browser retrieves the necessary content from a web server and then browser engine, transforms it into an interactive visual representation on the user's screen. If the user point and click, clicks or touchscreen, taps a hyperlink, link, the browser repeats this process to load the new URL, which could be part of the current website or a different one. The browser has web browser#Features, features, such as the address bar, that indicate which page is displayed. Elements A web page is a structured document. The core element is a text file written in the HT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |