causes of data loss

... unnamedTable = new System .Data. DataTable(); System .Data. DataTable namedTable = new System .Data. DataTable("Customer"); Visual Basic Dim unnamedTable As New System .Data. DataTable() Dim namedTable ... tabular data as a collection of collections. Each DataTable object contains a collection of ordered rows, each existing as an instance of a DataRow object. Each row contains its own collection of ... is the process of crafting tables that ensure data integrity and take advantage of the processing power of relational database systems. E.F. Codd, inventor of the relational database model,...

Ngày tải lên: 03/10/2013, 00:20

... tendency, the moments of a distribution, the median and mode. In §14.2 we learn to test whether different data sets are drawn from distributions with different values of these measures of central tendency. ... of integer powers of the values. Best known is the mean of the values x 1 , ,x N , x= 1 N N  j=1 x j (14.1.1) which estimates the value around which central clustering occurs. Note the use of an ... 610 Chapter 14. Statistical Description of Data Sample page from NUMERICAL RECIPES IN C: THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5) Copyright (C) 1988-1992...

Ngày tải lên: 20/10/2013, 17:15

... tendency, the moments of a distribution,the median and mode. In §14.2 we learn to test whether different data sets are drawn from distributions with different values of these measures of central tendency. ... of integer powers of the values. Best known is the mean of the values x 1 , ,x N , x= 1 N N  j=1 x j (14.1.1) which estimates the value around which central clustering occurs. Note the use of an ... the mean is not the only available estimator of this 614 Chapter 14. Statistical Description of Data Sample page from NUMERICAL RECIPES IN C: THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5) Copyright...

Ngày tải lên: 24/10/2013, 15:15

... makes use of the following routine for computing the mean and variance of a set of numbers, 620 Chapter 14. Statistical Description of Data Sample page from NUMERICAL RECIPES IN C: THE ART OF SCIENTIFIC ... routine void ftest(float data1 [], unsigned long n1, float data2 [], unsigned long n2, float *f, float *prob) Given the arrays data1 [1 n1] and data2 [1 n2] , this routine returns the value of f ,and its significance ... 1 degrees of freedom. The routine is #include <math.h> void tptest(float data1 [], float data2 [], unsigned long n, float *t, float *prob) Given the paired arrays data1 [1 n] and data2 [1 n] ,...

Ngày tải lên: 24/10/2013, 15:15

... the data sets are drawn from the same distribution. Small values of prob show that the cumulative distribution function of data1 is significantly different from that of data2 . The arrays data1 and data2 are ... number of data points, N e = N for the case (14.3.5) of one distribution, and N e = N 1 N 2 N 1 + N 2 (14.3.10) for the case (14.3.6) of two distributions, where N 1 is the number of data points ... consider the case of comparing two binned data sets. Let R i be the number of events in bin i for the first data set, S i the number of events in the same bin i for the second data set. Then the...

Ngày tải lên: 28/10/2013, 22:15

... . . 1. red # of red males N 11 # of red females N 21 # of green females N 22 # of green males N 12 # of males N 1 ⋅ # of females N 2 ⋅ 2. green # of red N ⋅ 1 # of green N ⋅ 2 total ... number of degrees of freedom is equal to the number of entries in the table (product of its row size and column size) minus the number of constraints that have arisen from our use of the data themselves ... since the total of the column totals and the total of the row totals both equal N, the total number of data points. Therefore, if the table is of size I by J, the number of degrees of freedom is IJ...

Ngày tải lên: 28/10/2013, 22:15

... respectively, the number of data points in the measurement of r 1 and r 2 . All of the significances above are two-sided. If you wish to disprove the null hypothesis in favor of a one-sided hypothesis, ... is the mean of the x i ’s, y is the mean of the y i ’s. The value of r lies between −1 and 1, inclusive. It takes on a value of 1,termed “complete positive correlation,” when the data points ... detecting correlation between uniform sets of integers between 1 and N, keeping in mind the possibilityof ties in the ranks. There is, of course, some loss of information in replacing the original...

Ngày tải lên: 07/11/2013, 19:15

... relative ordering of the ranks of the two x’s is opposite from the relative ordering of the ranks of the two y’s. If there is a tie in either the ranks of the two x’s or the ranks of the two y’s, ... kendl1(float data1 [], float data2 [], unsigned long n, float *tau, float *z, float *prob) Given data arrays data1 [1 n] and data2 [1 n] , this program returns Kendall’s τ as tau , its number of standard ... "nrutil.h" void spear(float data1 [], float data2 [], unsigned long n, float *d, float *zd, float *probd, float *rs, float *probrs) Given two data arrays, data1 [1 n] and data2 [1 n] , this routine...

Ngày tải lên: 07/11/2013, 19:15

... difference (ranging both over data points and over quadrants) of the corresponding integrated probabilities. When comparing two data sets, the value of D may depend on which data set is ranged over. ... tabulate Monte Carlo results for (what amounts to) the distribution of D as a function of (of course) D,samplesizeN, and coefficient of correlation r. Analyzing their results, one finds that the significance ... number of points as the real data set. Compute D for each synthetic data set, using the accompanying computer routines (but ignoring their calculated probabilities), and count what fraction of the...

Ngày tải lên: 07/11/2013, 19:15

Ngày tải lên: 07/12/2013, 11:40

... ? Introduction for the security  Networks and exchanges of data  Computer security  The risks Networks and exchanges of data  For the exchange of the data, we've changed the technology   The ... and exchanges of data The connection between Internet and the company's network open a large way with a lot of persons. They can use this solution and they obtain a lot of services. But ... :    Data shared with the clients and the partners Propose different services Profitability The agenda           Introduction for the security Networks and exchanges of data Computer...

Ngày tải lên: 09/12/2013, 17:22

... life of your data center. The Three Principles of Data Center Infrastructure Design Page 7 Deployment The graphic below depicts a sample data center using ADC's comprehensive line of data ... Category 6 Page 3 The Three Principles of Data Center Design When you understand the three principles of data center design, you are able to: • Lower your total cost of ownership • Support your future ... outside world, huge streams of data are transferred to and from equipment areas at extremely high data rates. The infrastructure must consistently support the flow of data without errors that...

Ngày tải lên: 10/12/2013, 03:15

... the data model. Modify the data model to support different functional requirements and alternate database designs by normalizing the storage of data before you create the database. Benefits of ... information, see Develop Complex Data Models and Design Databases course description. Overview of Data Modeling and Database Design 8Ć9 Database Design Designing a relational database system involves ... non-UID attribute. Overview of Data Modeling and Database Design 8Ć29 Designing the Database The database design stage produces design specifications for a relational database, including definitions...

Ngày tải lên: 10/12/2013, 17:15

... 900 Figure 14.8.1. Top: Synthetic noisy data consisting of a sequence of progressively narrower bumps, and additive Gaussian white noise. Center: Result of smoothing the data by a simple moving window average. ... window average. One seesthat the window of width 33 does quite a nicejob of smoothing the broadest bump, but that the narrower bumps suffer considerable loss of height and increase of width. The underlying ... synthetic data. Bottom: Result of smoothing the data by a Savitzky-Golay smoothing filter (of degree 4) using the same 33 points. While there is less smoothing of the broadest feature, narrower...

Ngày tải lên: 15/12/2013, 04:15

... measure of goodness -of- fit. When the third item suggests that the model is an unlikely match to the data, then items (i) and (ii) are probably worthless. Unfortunately, many practitioners of parameter ... graph of data and model “looks good.” This approach is known as chi-by-eye. Luckily, its practitioners get what they deserve. CITED REFERENCES AND FURTHER READING: Bevington, P.R. 1969, Data Reduction ... based on? The answer to these questions takes us into the subject of maximum likelihood estimators. Given a particular data set of x i ’s and y i ’s, we have the intuitive feeling that some parameter...

Ngày tải lên: 15/12/2013, 04:15

... [1] 15.2 Fitting Data to a Straight Line A concrete example will make the considerations of the previous section more meaningful. We consider the problem of fitting a set of N data points (x i ,y i )to a ... 68 percent of the time, within ±2σ 95 percent of the time, and within ±3σ 99.7 percent of the time. Extending this, one would expect a measurement to be off by ±20σ only one time out of 2 × 10 88 .Weall know ... that the standard deviations σ of these normal distributionsare the same for all points. Then the probability of the data set is the product of the probabilities of each point, P ∝ N  i=1  exp  − 1 2  y i −...

Ngày tải lên: 15/12/2013, 04:15

Ngày tải lên: 15/12/2013, 04:15

Ngày tải lên: 15/12/2013, 04:15

Ngày tải lên: 15/12/2013, 04:15

Ngày tải lên: 15/12/2013, 04:15