Search results for "Discriminant"
showing 10 items of 344 documents
Predictability and prediction of lowest observed adverse effect levels in a structurally heterogeneous set of chemicals
2005
A database of chronic lowest observed adverse effect levels (LOAELs) for 234 compounds, previously compiled from different sources (Toxicology Letters79, 131-143 (1995)), was modelled using graph theoretical descriptors. This study reveals that data are not homogeneous. Only those data originating from the U.S. Environmental Protection Agency (EPA) reports could be well modelled by multilinear regression (MLR) and linear discriminant analysis (LDA). In contrast, data available from the specific procedures of the National Toxicology Program (NTP) database introduced noise and did not render good models either alone, or in combination with the EPA data.
Application of molecular topology for the prediction of the reaction times and yields under solvent-free conditions
2010
Ball milling and conventional magnetic stirring can be used to support different laboratory techniques with a highly efficient mixing of reagents under solvent-free conditions. By using multilinear regression and linear discriminant analysis, topological-mathematical models have been built to predict the yield and the reaction time for organocatalytic reactions, Suzuki reactions and reactions of synthesis of heterocyclic compounds. The results from the in silico predictions confirm the usefulness of the approach followed.
International validation of the revised European Organisation for Research and treatment of cancer head and neck cancer module, the EORTC QLQ-HN43
2019
Background: We validated the new European Organisation for Research and Treatment of Cancer Quality of Life Head and Neck Module (EORTC QLQ-HN43). Methods: We enrolled 812 patients with head and neck cancer from 18 countries. Group 1 completed the questionnaire before therapy, and 3 and 6 months later. In group 2 (survivors), we determined test–retest reliability using intraclass correlation coefficients (ICC). Internal consistency was assessed using Cronbach's Alpha, the scale structure with confirmatory factor analysis, and discriminant validity with known-group comparisons. Results: Cronbach's alpha was >0.70 in 10 of the 12 multi-item scales. All standardized factor loadings exceeded…
CORPORATE BANKRUPTCY AND INSOLVENCY PREDICTION MODEL
2021
In any competitive economy, the risk of bankruptcy is pervasive. The research aims to contribute in improving the predictive power of bankruptcy and insolvency risk among companies by introducing new methods of processing and validation. This paper investigates the extensive application of the Z score model for predicting the economic-financial stability of Romanian companies in the manufacturing and extractive industries. A list of 37 financial indicators determined on the basis of the balance sheet data of 80 companies for the period 2015–2018 was used. Stepwise Least Squares Estimation through the Forward method allowed the identification of the most relevant ones. Canonical discriminant…
The Influence of Intangible Assets in the Company Performance: The Case of the World’s Most Profitable Corporations
2020
Intangible assets are no longer a competitive advantage, but a must if a company wants to create value for the long-term and maintain performance at a high level compared with its peers. Due to the various factors that contribute to the performance of a company, there are a plethora of methods to measure the impact of each one. This paper’s objective is to measure the performance of the company, with a focus on the contribution of the intangible assets. To fulfil this objective, financial ratios will be used, and a method (‘Calculated Intangible Value’) to quantify the impact of intangible assets. By applying a multiple discriminant analysis, two functions will result, a general one, and an…
Analysis of compatibility between lighting devices and descriptive features using Parzen’s kernel: application to flaw inspection by artificial vision
2000
We present a supervised method, developed for industrial inspections by artificial vision, to obtain an adapted combination of descriptive features and a lighting device. This method must be implemented under real-time constraints and therefore a minimal number of features must be selected. The method is based on the assessment of the discrimination power of many descriptive features. The objective is to select the combination of descriptive features and lighting system best able to discriminate flawed classes from defect-free classes. In the first step, probability densities are computed for flawed and defect-free classes and for each tested combination. The discrimination power of the fea…
Assessment of the statistical significance of classifications in infrared spectroscopy based diagnostic models.
2014
Fourier transform infrared (IR) spectroscopy in combination with multivariate data analysis is a versatile tool that can be applied to disease diagnosis. However, a rigorous validation of the obtained models is necessary in order to obtain robust results. This work evaluates the advantages of the use of permutation testing for determining the statistical significance of the misclassification errors obtained from IR based diagnostic models through cross validation (CV). The model performance, estimated by CV, is compared to a distribution of CV-performance values obtained using randomly permuted class labels. The distribution of ‘random CV-values’ is considered as a null distribution and use…
Psychosocial adjustment in aggressive popular and aggressive rejected adolescents at school+
2014
AbstractThe purpose of the present study was to compare the profiles of aggressive adolescents who differed in social status in the classroom, popular vs. rejected, with those of adolescents of average sociometric status without documented behavior problems. The characteristics compared related to intra-individual, family, school, and social domains. A sample of 457 adolescents, aged 11 to 18 years old (48% girls), participated in the study. Differences between groups were examined via a series of multivariate analyses of variance and discriminant function analyses. Results indicated that although aggressive popular adolescents revealed more academic involvement and social integration in th…
Diagnosis of damage to Norway spruce (Picea abies) through biochemical criteria
1995
Bioindication can be carried out at different hierarchical levels, eg. cell, organism, and ecosystem. While the monitoring of damage by visible criteria (e.g. loss of needles) is connected with the organism as a whole, the monitoring of damage by biochemical indicators is above all connected with cell metabolism. The degree of vitality of a tree can be ascertained through the integration of a number of biochemical parameters. Furthermore, a differential diagnosis of a particular stress pattern can be carried out because of the feedback pattern of several biochemical indicators. In order to describe and interpret biochemical or physiological changes that have been caused by a number of facto…
A multivariate approach to the study of orichalcum ingots from the underwater Gela's archaeological site
2017
Abstract In this work a careful ICP-OES and ICP-MS investigation of 38 ancient ingots has been performed to determine both major components and trace elements content to find a correlation between the observed different features and the composition. The ingots, recovered in an underwater archaeological site of various finds near Gela (CL, Italy), were previously investigated by X-Ray Fluorescence (XRF) spectroscopy to know the composition of the alloy and it was found that the major elements were copper and zinc, in a ratio compatible with the famous orichalcum similar to the contemporary brass that was considered a precious metal in ancient times. The discovery of huge amount this alloy is…