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Decision trees are powerful and popular tools for classification and prediction. The attractiveness of tree-based methods is due in large part to the fact that, in contrast to neural networks, decision trees represent rules. Rules can readily be expressed so that we humans can understand them or in a database access language like SQL so that record...
15 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 2168 | Lượt tải: 0
When is association rule analysis useful? An appeal of market analysis comes from the clarity and utility of its results, which are in the form of association rules. There is an intuitive appeal to a market analysis because it expresses how tangible products and services relate to each other, how they tend to group together. A rule like, “if a cust...
12 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 2119 | Lượt tải: 0
In the real world of data-mining applications, more effort is expended preparing data than applying a prediction program to data. Data mining methods are quite capable of finding valuable patterns in data. It is straightforward to apply a method to data and then judge the value of its results based on the estimated predictive performance. This does...
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Contents Preface Chapter 1. Overview of Knowledge Discovery and Data Mining 1.1 What is Knowledge Discovery and Data Mining? 1.2 The KDD Process 1.3 KDD and Related Fields 1.4 Data Mining Methods 1.5 Why is KDD Necessary? 1.6 KDD Applications 1.7 Challenges for KDD Chapter 2. Preprocessing Data 2.1 Data Quality 2.2 Data Transformations 2.3 Missing ...
20 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 2111 | Lượt tải: 2
Launch the Windows Control Panel and then choose Administrative Tools➪ODBC. 2. In the ODBC Data Source Administrator dialog box, click either the User DSN or System DSN tab. Selecting the System DSN tab is generally a good idea; your data source is then visible to other users on your computer. 3. From the list of drivers, pick either the SQL Native...
33 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 1855 | Lượt tải: 0
Continuing, you now see a nested element known as Customer, whose start tag is <Customer> and end tag is </Customer>. This element itself contains two nested elements, one known as Name, and the other known as Identifier. It also contains a nested element known as Instructions. This element and those nested within it appear to be a litt...
42 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 1931 | Lượt tải: 0
Now that you’re an expert on all of the moving parts found in SQL Server’s reporting architecture, it’s time to start putting them to work for you. To begin, I call out those important but somewhat tedious tasks that you need to take care of before you can get to the fun stuff: 1. Make sure that your computer has the complete reporting support infr...
42 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 1965 | Lượt tải: 0
Now that you have this information, you can take action if necessary: -- If there isn’t enough inventory, then order some more IF (@quantity_on_hand + @part_request_count > @minimum_number) INSERT INTO reorder VALUES (@part_number, @minimum_number) -- If it’s a white elephant, tell the buyer the good news IF @bad_item > 0 exec sqlexpress.msdb...
42 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 1954 | Lượt tải: 0
Naturally, you can write more complicated UPDATE statements. To do so, you often use the same advanced search syntax that you use in your SELECT statements. Before running any blanket, potentially widespread UPDATE statements, why not try them out as a SELECT statement first? You have nothing to lose by doing so, and you can also spot errors before...
42 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 1884 | Lượt tải: 0
To get the latest-and-greatest view of everything about your SQL Server 2005 Express instance, right-click anywhere on the Object Explorer tree and choose Refresh. The Query window The Query window is where you and SQL Server 2005 Express get to know each other, up close and personal. The workspace contains input windows (described as the Query Edi...
42 trang | Chia sẻ: tlsuongmuoi | Ngày: 19/04/2013 | Lượt xem: 1838 | Lượt tải: 0