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Meta-analysis is a method to obtain a weighted average of results from various studies. In addition to pooling effect sizes, meta-analysis can also be used to estimate disease frequencies, such as incidence and prevalence. In this article we present methods for the meta-analysis of prevalence. We discuss the logit and double arcsine transformations to stabilise the variance. We note the special situation of multiple category prevalence, and propose solutions to the problems that arise. We describe the implementation of these methods in the MetaXL software, and present a simulation study and the example of multiple sclerosis from the Global Burden of Disease 2010 project. We conclude that the double arcsine transformation is preferred over the logit, and that the MetaXL implementation of multiple category prevalence is an improvem...
In correspondence analysis, rows and columns of a data matrix are depicted as points in low-dimensional space. The row and column profiles are approximated by minimizing the so-called weighted chi squared distance between the original profiles and their approximations, see or example, Greenacre (1984). In this paper, we will study the inverse correspondence analysis solution. We will show that there exists a nonempty closed and bounded polyhedron of such matrices. We also present an algorithm to find the vertices of the polyhedron. A proof that the maximum of the Pearson chi-squared statistic is attained at one of the vertices is given. In addition, it is discussed how extra equality constraints on some elements of the data matrix can be imposed on the inverse correspondence analysis problem. As a special case, we present a me...
Since the mid-1980s, the design of various technologies such as user interfaces for photocopiers, surgical monitoring alarms, London Underground control systems, videoconferencing software, and interactive museum exhibits has benefited from investigations informed by conversation analysis (CA). The exemplar studies which form the basis of this entry are best understood as contributions of CA-informed work, rather than contributions to the discipline of CA.
abstractIn correspondence analysis, rows and columns of a data matrix are depicted as points in low-dimensional space. The row and column profiles are approximated by minimizing the so-called weighted chi squared distance between the original profiles and their approximations, see or example, Greenacre (1984). In this paper, we will study the inverse correspondence analysis solution. We will show that there exists a nonempty closed and bounded polyhedron of such matrices. We also present an algorithm to find the vertices of the polyhedron. A proof that the maximum of the Pearson chi-squared statistic is attained at one of the vertices is given. In addition, it is discussed how extra equality constraints on some elements of the data matrix can be imposed on the inverse correspondence analysis problem. As a special case, we pres...
Comment: 37 pages, 19 figures
Many techniques for array processing assume either that the system has a calibrated array or that the noise covariance matrix is known. If the noise covariance matrix is unknown, training or other calibration techniques are used to find it. In this thesis another approach to the problem of unknown noise covariance is presented. The factor analysis (FA) model is used to model the data. In order to make the theory applicable in telecommunication and radio astronomy, the model is extended to the case of complex numbers. The necessary mathematical tools for estimation, detection and performance analysis are derived. The maximum likelihood estimator for the FA model in the case of proper complex Gaussian distributed noise and signals is given. Two different iterative algorithms for finding the MLE of the model parameters are presented. The ...
Usual modal analysis techniques are based on the Fourier transform. Due to the Delta T . Delta f limitation, they perform poorly when the modal overlap mu exceeds 30%. A technique based on a high-resolution analysis algorithm and an order-detection method is presented here, with the aim of filling the gap between the low- and the high-frequency domains (30%<mu<100%). A pseudo-impulse force is applied at points of interests of a structure and the response is measured at a given point. For each pair of measurements, the impulse response of the structure is retrieved by deconvolving the pseudo-impulse force and filtering the response with the result. Following conditioning treatments, the reconstructed impulse response is analysed in different frequency-bands. In each frequency-band, the number of modes is evaluated, the frequencies and...
DyadicDA is a package of 4 self-contained SPSS syntax files for the analysis of standard dyadic designs. Inter Programs apply to the measurement of non interdependence. VarTypy is a complementary program for checking data processing errors. Inter1.sps is an SPSS syntax file that calculates, tests, and computes confidence interval bounds for Pearson product-moment correlations, intraclass correlation coefficients, and pairwise correlations in reciprocal standard dyadic designs with interval level measures. The program can be used for distinguishable and indistinguishable dyad members. Inter2.sps is an SPSS syntax file that calculates, tests, and computes confidence interval bounds for Cohen's kappa coefficient in reciprocal standard dyadic designs with categorical measures (tabulated data). The program can be used for distinguishable a...
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