The optimal allocation of available resources is the concern of every investigator in choosing a study design. The recent development of statistical methods for the analysis of two-stage data makes these study designs attractive for their economy and efficiency. However, little work has been done on deriving two-stage designs that are optimal under the kinds of constraints encountered in practi...

Objective: The present study aimed to compare mental health of female athlete and non-athlete students in the city of Indica. The research methodology was a descriptive survey, which initially described the mental health and then compared it among the students. Methods: The statistical population of the study included all high school girls in the academic year of 2012-2013 in the city of Indica...

AIMS A population based cross sectional survey was conducted to determine the magnitude of cataract blindness and the barriers to uptake of cataract services in a rural community of northern Nigeria. METHODS 1461 people out of 1924 registered eligible people were examined. The study population was chosen by two stage cluster random sampling. In the first sampling stage 15 villages were random...

Background: In an effort to plan for effective community-based cataract surgical services in Igabi district of northern Nigeria, the National Eye Centre, Kaduna (a tertiary eye hospital) conducted a population-based cross sectional survey in the district. The survey was conducted in order to generate baseline data on cataract blindness in the district. Methods: A total of 2044 people out of 240...

Cluster computation power provides a promising way to improve response time in large data warehouses. On the other hand, the use of sampling summaries on the cluster for approximate answering of OLAP queries provides a very flexible system that can provide response time guarantees. In this paper we explore the cluster computation paradigm for data warehouses and summaries. The use of cluster co...

1. Introduction The Medicare Current Beneficiary Survey (MCBS) conducted by the Centers for Medicare and Medicaid Services (CMS), Department of Health and Human Services, is a continuous sample survey of Medicare beneficiaries residing in the United States and Puerto Rico. The MCBS collects data on access to health care, health status, source of care, health care utilization and costs, satisfac...

Multilevel regression with poststratification (MRP) has become widely used in political science to estimate subnational opinion from national polls. This method takes into account both demographic and state-level effects and has greatly expanded knowledge of public opinion at the subnational level. In this paper, I assess the use of MRP on two cluster-sampled polls, the American National Electi...

This paper presents a SVM classification method based on cluster boundary sampling and sample pruning. We actively explore an effective solution to solve the difficult problem of imbalanced data set classification from data re-sampling and algorithm improving. Firstly, we creatively propose the method of cluster boundary sampling, using the clustering density threshold and the boundary density ...

The problem of clustering large data sets has attracted a lot of current research. The approaches taken are mainly based either on the more efficient implementation or modification of existing methods or/and on the construction of clusters from a small sub-sample of the data and then the assignment of all observations in those clusters. The current paper focuses on the latter direction. An alte...