Search Results

You are looking at 1 - 10 of 102 items for :

  • "discriminant analysis" x
  • Refine by Access: All Content x
Clear All

. Discriminant analysis for billbug resistance ratings. J. of the Am. Soc. for Horticultural Sci. 112 :978–980. Shearman R.C. Discriminant analysis for billbug resistance ratings

Restricted access

Alfò, M. and P. Postiglione. 1999. Discriminant analysis using mark-ovian automodels. In: M. Vichi and O. Opitz (eds.), Classification and Data Analysis. Theory and Application. Springer-Verlag, Heidelberg, pp. 73

Restricted access

aimed at predicting the classification of USA-domestic cannabis samples based on GC-chromatographic profiles of cannabinoids and terpenoids using Linear Discriminant Analysis (LDA). In this work, quantitative classification of 54 collected cannabis

Open access

Summary  

In general, when characterizing samples, such as ceramic samples or other types of samples, for first time by means of chemical elements, the analyst measures a large number of variables, many of which may not be very informative. In fact, some may even be unrelated to the issue at hand and blur the picture instead of making it clearer. In subsequent studies the analyst may wish to measure fewer variables for several reasons, such as being very time consuming; in cases where measurement time is important, such as on-line monitoring; in order to reduce cost or effort; etc. Therefore, the hope is to determine those variables that are most relevant without losing essential information and to remove the less productive information. The problem is how to perform this in an objective way and to capture crucial information using a multivariate analysis. This paper aims to describe and illustrate a stopping rule for the identification of redundant variables, and the selection of variable subsets, preserving multivariate data structure using stepwise discriminant analysis, selecting those variables that are in some senses adequate for discrimination purposes. One illustrative example using data sets obtained via INAA of ceramic samples from two archaeological sites is provided.

Restricted access

We present the sufficient condition for a classical two-class problem from Fisher discriminant analysis has a solution. Actually, the solution was presented up to our knowledge with a necessary condition only. We use an extended Cauchy–Schwarz inequality as a tool.

Restricted access

Abstract  

A multivariate statistical technique-factoral discriminant analysis (FDA)-has been used to evaluate the occupational esposure of a group of metallurgy workers using the elemental composition of their scalp hair, as compared with a control group. The initial variables were the concentrations of ten minor and trace elements Al, Co, Cu, Fe, Mg, Mn, Sb, Se, V, and Zn determined in hair samples by using instrumental neutron activation analysis (INAA). A good discrimination between exposed and control subjects has been achieved after the normalization of the data (by log-transforming the initial variables) and considering sex-matched groups. To measure the accuracy of the classification and the predictive ability a cross-validation procedure was used.

Restricted access

location / related watershed. Statistical models mostly consist of multivariate analysis tools (hierarchical cluster analysis [HCA], principal component analysis, correlation analysis, linear discriminant analysis [LDA] –to mention only a few), which lead

Open access

The objective of the research was to compare the taste attributes of different commercial soya drinks. Furthermore, the task was to determine the effect of different ingredients and processing technologies on the taste attributes of the product. Based on the results of electronic tongue measurements the instrument is able to determine the effect of the applied technology and to distinguish soya juice samples according to sensory preferences. Canonical discriminant analysis showed that the groups of two measurements of the same products were overlapping. Therefore, the electronic tongue measurements are supposed to be of acceptable repeatability. The canonical discriminant analysis showed that the taste attributes of soya juice made of hulled soybeans was beneficial for the taste attributes relative to that of the juice made of not-hulled soybeans. Three main groups could be observed from the analyzed six commercial soya drink samples based on canonical discriminant analysis. There is a group of top market brands having definite taste improver additives and another one containing three products having low amount of additives. However, the group of samples made of soybean and rice is located between the above-mentioned two groups in the discriminant score plot.

Restricted access

Summary

A simple and rapid method, using online ultraperformance liquid chromatography with photodiode array detection and electrospray ionization mass spectrometry (UPLC-PDA-eλ-ESI-MS/MS), was developed for the in-depth analysis of 50 batches Radix et Rhizoma Rhei. The analysis was performed on a UPLC BEH C18 column using a gradient elution system. Baseline separation could be achieved in less than 7.5 min. At the same time, on the basis of the 50 batches of samples collected from representative cultivated regions, a novel chromatographic fingerprint was devised by UPLC-PDA, in which 27 common peaks were detected and identified by the developed UPLC-MS/MS method step by step according to fragmentation mechanisms, MS/MS data, standards, and relevant literature. Many active components gave prominent [M - H] ions in the ESI mass spectra. These components include anthraquinones, sennosides, stilbenes, glucose gallates, naphthalenes, and catechins. Furthermore, based on the information of these Radix et Rhizoma Rhei components, and further combined with discriminant analysis, a novel discriminant analysis equation (DAE) was established for the quality control of Radix et Rhizoma Rhei for the first time.

Full access

analyses. Firstly, the European countries are divided into two clusters as healthy-less healthy and wealthy-less wealthy for each year by Two-step Cluster analysis. These binary variables are, then, taken as dependent variables in the Discriminant analysis

Restricted access