This paper compares the type I error and power of the one- and two-sample t-tests, and the one- and two-sample permutation tests for detecting differences in gene expression between two microarray samples with replicates using Monte Carlo simulations. When data are generated from a normal distribution, type I errors and powers of the one-sample parametric t-test and one-sample permutation test ...

BACKGROUND Physical activity (PA) surveillance is an important component of non-communicable disease risk factor monitoring, and occurs through national and international surveillance systems. This review identifies population PA estimates for adults in the Asia-Pacific region, and examines variation in trends and prevalence rates obtained using different PA measures. METHODS Data were obtain...

CONTEXT Controversy and uncertainty ensue when the results of clinical research on the effectiveness of interventions are subsequently contradicted. Controversies are most prominent when high-impact research is involved. OBJECTIVES To understand how frequently highly cited studies are contradicted or find effects that are stronger than in other similar studies and to discern whether specific ...

Detection of interacting risk factors for complex traits is challenging. The choice of an appropriate method, sample size, and allocation of cases and controls are serious concerns. To provide empirical guidelines for planning such studies and data analyses, we investigated the performance of the multifactor dimensionality reduction (MDR) and generalized MDR (GMDR) methods under various experim...

OBJECTIVE The aim of study is to introduce method of Soft Independent Modeling of Class Analogy (SIMCA), and to express whether the method is affected from the number of independent variables, the relationship between variables and sample size. STUDY DESIGN Simulation study. MATERIAL AND METHODS SIMCA model is performed in two stages. In order to determine whether the method is influenced b...

Increasing global notices in environmental protection, green supply chain management (GSCM) has received much attention by researchers and managers more than the past. Commonly, firms have considered cost criteria to select their suppliers. Despite the fact that there are various papers considering the formal criteria in supplier selection, there is a few limited numbers considering the environ...

A one-way randomeffectsmodel is consideredfor the log-transformedshift-longpersonal exposure measurements, where the random effect in the model represents an effect due to the worker. Following a previousapproach,we address a hypothesis-testingproblem involving the proportionof workers for whom the mean exposure exceeds the occupational exposure limit. A conŽ dence interval is constructed for t...