1、毕业设计（论文）外文翻译 基于数据挖掘技术的 WWW 推荐系统设计 英文原文 Data Mining: What is Data Mining? Overview Generally, data mining (sometimes called data or knowledge discovery) is the process of analyzing data from different perspectives and summarizing it into useful information - information that can be used to increase r
2、evenue, cuts costs, or both. Data mining software is one of a number of analytical tools for analyzing data. It allows users to analyze data from many different dimensions or angles, categorize it, and summarize the relationships identified. Technically, data mining is the process of finding correla
3、tions or patterns among dozens of fields in large relational databases. Continuous Innovation Although data mining is a relatively new term, the technology is not. Companies have used powerful computers to sift through volumes of supermarket scanner data and analyze market research reports for years
4、. However, continuous innovations in computer processing power, disk storage, and statistical software are dramatically increasing the accuracy of analysis while driving down the cost. Example For example, one Midwest grocery chain used the data mining capacity of Oracle software to analyze local bu
5、ying patterns. They discovered that when men bought diapers on Thursdays and Saturdays, they also tended to buy beer. Further analysis showed that these shoppers typically did their weekly grocery shopping on Saturdays. On Thursdays, however, they only bought a few items. The retailer concluded that
6、 they purchased the beer to have it available for the upcoming weekend. The grocery chain could use this newly discovered information in various ways to increase revenue. For example, they could move the beer display closer to the diaper display. And, they could make sure beer and diapers were sold
7、at full price on Thursdays. Data, Information, and Knowledge Data Data are any facts, numbers, or text that can be processed by a computer. Today, organizations are accumulating vast and growing amounts of data in different formats and different databases. This includes: operational or transactional
8、 data such as, sales, cost, inventory, payroll, and accounting nonoperational data, such as industry sales, forecast data, and macro economic data meta data - data about the data itself, such as logical database design or data dictionary definitions Information The patterns, associations, or relatio
9、nships among all this data can provide information. For example, analysis of retail point of sale transaction data can yield information on which products are selling and when. Knowledge Information can be converted into knowledge about historical patterns and future trends. For example, summary inf
10、ormation on retail supermarket sales can be analyzed in light of promotional efforts to provide knowledge of consumer buying behavior. Thus, a manufacturer or retailer could determine which items are most susceptible to promotional efforts. Data Warehouses Dramatic advances in data capture, processi
11、ng power, data transmission, and storage capabilities are enabling organizations to integrate their various databases into data warehouses. Data warehousing is defined as a process of centralized data management and retrieval. Data warehousing, like data mining, is a relatively new term although the
12、 concept itself has been around for years. Data warehousing represents an ideal vision of maintaining a central repository of all organizational data. Centralization of data is needed to maximize user access and analysis. Dramatic technological advances are making this vision a reality for many comp
13、anies. And, equally dramatic advances in data analysis software are allowing users to access this data freely. The data analysis software is what supports data mining. What can data mining do? Data mining is primarily used today by companies with a strong consumer focus - retail, financial, communic
14、ation, and marketing organizations. It enables these companies to determine relationships among internal factors such as price, product positioning, or staff skills, and external factors such as economic indicators, competition, and customer demographics. And, it enables them to determine the impact
15、 on sales, customer satisfaction, and corporate profits. Finally, it enables them to drill down into summary information to view detail transactional data. With data mining, a retailer could use point-of-sale records of customer purchases to send targeted promotions based on an individuals purchase
16、history. By mining demographic data from comment or warranty cards, the retailer could develop products and promotions to appeal to specific customer segments. For example, Blockbuster Entertainment mines its video rental history database to recommend rentals to individual customers. American Expres
17、s can suggest products to its cardholders based on analysis of their monthly expenditures. WalMart is pioneering massive data mining to transform its supplier relationships. WalMart captures point-of-sale transactions from over 2,900 stores in 6 countries and continuously transmits this data to its
18、massive 7.5 terabyte Teradata data warehouse. WalMart allows more than 3,500 suppliers, to access data on their products and perform data analyses. These suppliers use this data to identify customer buying patterns at the store display level. They use this information to manage local store inventory
19、 and identify new merchandising opportunities. In 1995, WalMart computers processed over 1 million complex data queries. The National Basketball Association (NBA) is exploring a data mining application that can be used in conjunction with image recordings of basketball games. The Advanced Scout soft
20、ware analyzes the movements of players to help coaches orchestrate plays and strategies. For example, an analysis of the play-by-play sheet of the game played between the New York Knicks and the Cleveland Cavaliers on January 6, 1995 reveals that when Mark Price played the Guard position, John Willi
21、ams attempted four jump shots and made each one! Advanced Scout not only finds this pattern, but explains that it is interesting because it differs considerably from the average shooting percentage of 49.30% for the Cavaliers during that game. By using the NBA universal clock, a coach can automatica
22、lly bring up the video clips showing each of the jump shots attempted by Williams with Price on the floor, without needing to comb through hours of video footage. Those clips show a very successful pick-and-roll play in which Price draws the Knicks defense and then finds Williams for an open jump sh
23、ot. How does data mining work? While large-scale information technology has been evolving separate transaction and analytical systems, data mining provides the link between the two. Data mining software analyzes relationships and patterns in stored transaction data based on open-ended user queries.
24、Several types of analytical software are available: statistical, machine learning, and neural networks. Generally, any of four types of relationships are sought: Classes: Stored data is used to locate data in predetermined groups. For example, a restaurant chain could mine customer purchase data to
25、determine when customers visit and what they typically order. This information could be used to increase traffic by having daily specials. Clusters: Data items are grouped according to logical relationships or consumer preferences. For example, data can be mined to identify market segments or consum
26、er affinities. Associations: Data can be mined to identify associations. The beer-diaper example is an example of associative mining. Sequential patterns: Data is mined to anticipate behavior patterns and trends. For example, an outdoor equipment retailer could predict the likelihood of a backpack b
27、eing purchased based on a consumers purchase of sleeping bags and hiking shoes. Data mining consists of five major elements: Extract, transform, and load transaction data onto the data warehouse system. Store and manage the data in a multidimensional database system. Provide data access to business
28、analysts and information technology professionals. Analyze the data by application software. Present the data in a useful format, such as a graph or table. Different levels of analysis are available: Artificial neural networks: Non-linear predictive models that learn through training and resemble bi
29、ological neural networks in structure. Genetic algorithms: Optimization techniques that use processes such as genetic combination, mutation, and natural selection in a design based on the concepts of natural evolution. Decision trees: Tree-shaped structures that represent sets of decisions. These de
30、cisions generate rules for the classification of a dataset. Specific decision tree methods include Classification and Regression Trees (CART) and Chi Square Automatic Interaction Detection (CHAID) . CART and CHAID are decision tree techniques used for classification of a dataset. They provide a set
31、of rules that you can apply to a new (unclassified) dataset to predict which records will have a given outcome. CART segments a dataset by creating 2-way splits while CHAID segments using chi square tests to create multi-way splits. CART typically requires less data preparation than CHAID. Nearest n
32、eighbor method: A technique that classifies each record in a dataset based on a combination of the classes of the k record(s) most similar to it in a historical dataset (where k 1). Sometimes called the k-nearest neighbor technique. Rule induction: The extraction of useful if-then rules from data ba
33、sed on statistical significance. Data visualization: The visual interpretation of complex relationships in multidimensional data. Graphics tools are used to illustrate data relationships. What technological infrastructure is required? Today, data mining applications are available on all size systems
34、 for mainframe, client/server, and PC platforms. System prices range from several thousand dollars for the smallest applications up to $1 million a terabyte for the largest. Enterprise-wide applications generally range in size from 10 gigabytes to over 11 terabytes. NCR has the capacity to deliver a
35、pplications exceeding 100 terabytes. There are two critical technological drivers: Size of the database: the more data being processed and maintained, the more powerful the system required. Query complexity: the more complex the queries and the greater the number of queries being processed, the more powerful the system required. Relational database storage and management technology is adequate for many data mining applications less
