Introduction: Teacher evaluation, as an important strategyfor improving the quality of education, has been considered byuniversities and leads to a better understanding of the strengthsand weaknesses of education. Analysis of instructors’ scoresis one of the main fields of educational research. Since outliersaffect analysis and interpretation of information processes bothstructurally and concep...

Usually when performing a statistical test or estimation procedure, we assume the data are all observations of i.i.d. random variables, often from a normal distribution. Sometimes, however, we notice in a sample one or more observations that stand out from the crowd. These observation(s) are commonly called outlier(s). Outlier tests are more formal procedures which have been developed for detec...

Medical imaging datasets often contain deviant observations, the so-called outliers, due to acquisition or preprocessing artifacts or resulting from large intrinsic inter-subject variability. These can undermine the statistical procedures used in group studies as the latter assume that the cohorts are composed of homogeneous samples with anatomical or functional features clustered around a cent...

Starting from two datasets of codon usage in coding sequences from mesophilic and thermophilic bacteria, we used internal correspondence analysis to study the variability of codon usage within and between species, and within and between amino acids. The first dataset included 18,958,458 codons from 58,482 coding sequences from completely sequenced genomes of 25 species, along with 6,793,581 din...

AbstractWe propose a novel unsupervised keyphrase extraction approach that filters candidate keywords using outlier detection. It starts by training word embeddings on the target document to capture semantic regularities among words. then uses minimum covariance determinant estimator model distribution of non-keyphrase vectors, under assumption these vectors come from same distribution, indicat...

Our aim is to construct a factor analysis method that can resist the effect of outliers. We start with a highly robust initial covariance estimator, after which the factors can be obtained from maximum likelihood or from principal factor analysis (PFA). We find that PFA based on the minimum covariance determinant scatter matrix works well. We also derive the influence function of the PFA method...

In modern statistics the robust estimation of parameters is a central problem, i. e., an estimation that is not or only slightly affected by outliers in the data. The Minimum Covariance Determinant estimator (MCD) [8] is probably one of the most important robust estimators of location and scatter. The complexity of computing the MCD, however, was unknown and generally thought to be exponential ...

For the treatment of foliar diseases of cereals, fungicides may be applied as foliar sprays or systemic seed treatments which are translocated to leaves. Little research has been done to assess the resistance risks associated with foliar-acting systemic seed treatments when used alone or in combination with foliar sprays, even though both types of treatment may share the same mode of action. It...

Fungicides are considered to be effective crop protection chemicals in modern agriculture. However, they can also exert toxic effects on non-target organisms, including soil-dwelling microbes. Therefore, the environmental fate of fungicides has to be closely monitored. The aim of this study was to evaluate the influence of the Falcon 460 EC fungicide on microbial diversity, enzyme activity and ...