Validation of Soft Classification Models using Partial Class Memberships: An Extended Concept of Sensitivity & Co. applied to the Grading of Astrocytoma Tissues

We use partial class memberships in soft classification to model uncertain labelling and mixtures of classes. Partial class memberships are not restricted to predictions, but may also occur in reference labels (ground truth, gold standard diagnosis) for training and validation data. Classifier performance is usually expressed as fractions of the confusion matrix, such as sensitivity, specificity, negative and positive predictive values. We extend this concept to soft classification and discuss the bias and variance properties of the extended performance measures. Ambiguity in reference labels translates to differences between best-case, expected and worst-case performance. We show a second set of measures comparing expected and ideal performance which is closely related to regression performance, namely the root mean squared error RMSE and the mean absolute error MAE. All calculations apply to classical crisp classification as well as to soft classification (partial class memberships and/or one-class classifiers). The proposed performance measures allow to test classifiers with actual borderline cases. In addition, hardening of e.g. posterior probabilities into class labels is not necessary, avoiding the corresponding information loss and increase in variance. We implement the proposed performance measures in the R package "softclassval", which is available from CRAN and at http://softclassval.r-forge.r-project.org. Our reasoning as well as the importance of partial memberships for chemometric classification is illustrated by a real-word application: astrocytoma brain tumor tissue grading (80 patients, 37000 spectra) for finding surgical excision borders. As borderline cases are the actual target of the analytical technique, samples which are diagnosed to be borderline cases must be included in the validation.Comment: The manuscript is accepted for publication in Chemometrics and Intelligent Laboratory Systems. Supplementary figures and tables are at the end of the pd

Wheat Productivity and Plough Land Inequality in Rural Croatia

The unequal distribution of plough land could be according to a prior naive theorizing be a source of inefficiency in wheat production. The paper investigates whether, plough land inequality due to specific less or more egalitarian land distribution, and is a source of possible inefficiency measured by wheat productivity within Croatia's counties. We analyze these issues by using cross-county data on inequality in operational holdings of plough land from Agricultural Survey in 2003. After constructing the Gini coefficient for plough land holdings, and other relevant exogenous variable which cover necessary inputs condition as a average holding size per ha, labor, capital (represented by alternative variables summed by number of combine harvester and tractor), among counties, an estimation of an production function, is done by OLS estimations of wheat output.Wheat Productivity, Production Function, Plough Land Inequality, Croatia

E-learning readiness of organization and employees

E-learning is a widely used form of education. There are various kinds of e-learning both from the implementing institutions’ as well as from the learners’ point of view. As the learners are of different professions and educations, e-learning requires an individual approach for each users’ population. The effectiveness of e-learning has been researched, measured and  proved as beneficial as other forms of learning, although the problem of readiness for learning activities which would employ modern means of education was not as high. The article presents outcomes of a research made among the group of social service workers in terms of their abilities to undertake e-learning educatio

Measurements of top quark properties in top pair production and decay at the LHC using the CMS detector

AbstractMeasurements are presented of the properties of top quarks in pair production and decay from proton-proton collisions at the LHC. The data were collected at centre-of-mass energies of 7 and 8 TeV by the CMS experiment during the years 2011 and 2012. The top quark-antiquark charge asymmetry is measured using the difference of the absolute rapidities of the reconstructed top and anti-top kinematics, as well as from distributions of the top quark decay products. The measurements are performed in the decay channels of the tt‾ pair into both one and two leptons in the final state. The polarization of top quarks and top pair spin correlations are measured from the angular distributions of top quark decay products. The W-boson helicity fractions and angular asymmetries are extracted and limits on anomalous contributions to the Wtb vertex are determined. The flavor content in top-quark pair events is measured using the fraction of top quarks decaying into a W-boson and a b-quark relative to all top quark decays, R=B(t→Wb)/B(t→Wq), and the result is used to determine the CKM matrix element Vtb as well as the width of the top quark resonance. All of the results are found to be in good agreement with standard model predictions

Completion of the reconstruction of the entire national economy

https://stars.library.ucf.edu/prism/1390/thumbnail.jp