Background: Iran has a high C-section rate (40.6% in 2005). The objective of this study was to assess the associations and population-attributable risks (PAR) of risk factors combinations and C-section in the Southwest Iran. Methods: We performed a population-based cohort study using the reports provided by Shiraz University of Medical Sciences. The cohort included pregnant women within Sept...

In the context of polytomous regression, as with any generalized linear model, robustness issues are well documented. Existing robust estimators designed to protect against misclassification, but do not outlying covariates. It is shown that this can have a much bigger impact on estimation and testing than misclassification alone. To address problem, two new introduced: model-type estimator an o...

چکیده شناسایی رقومی خاک ها بهعنوان ابزاری برای ایجاد اطلاعات مکانی خاک، راه حل هایی برای نیاز رو به افزایش نقشه های خاک با تفکیک مکانی بالا را تأمین می کند. بنابراین، باید روش های جدید بهمنظور بهدست آوردن اطلاعات مکانی خاک با تفکیک مکانی بالا توسعه پیدا کند. به همین منظور مطالعه ای جهت پیش بینی کلاس های خاک با استفاده از مدل های رگرسیونی در منطقه زرند کرمان طراحی گردید. در این مطالعه، مدل های ر...

Considerable effort has gone into understanding issues of privacy protection of individual information in single databases, and various solutions have been proposed depending on the nature of the data, the ways in which the database will be used and the precise nature of the privacy protection being offered. Once data are merged across sources, however, the nature of the problem becomes far mor...

DOI: 10.5935/abc.20130120 Dear Editor, We would like to present a few considerations pursuant to the statistical analysis of the predictors of death in the article by Caluza et al1, even though observing its nature of initial/pilot project. It has not remained clear which variables were included in the initial model and which method was used to select those significant variables in the final ad...

background: iran has a high c-section rate (40.6% in 2005). the objective of this study was to assess the associations and population-attributable risks (par) of risk factors combinations and c-section in the southwest iran. methods: we performed a population-based cohort study using the reports provided by shiraz university of medical sciences. the cohort included pregnant women within septemb...

In this paper, we develop an efficient logistic regression model for multiple instance learning that combines L1 andL2 regularisation techniques. AnL1 regularised logistic regression model is first learned to find out the sparse pattern of the features. To train the L1 model efficiently, we employ a convex differentiable approximation of the L1 cost function which can be solved by a quasi Newto...

In dementia screening tests, item selection for shortening an existing screening test can be achieved using multiple logistic regression. However, maximum likelihood estimates for such logistic regression models often experience serious bias or even non-existence because of separation and multicollinearity problems resulting from a large number of highly correlated items. Firth (1993, Biometrik...