Using discriminant function analysis to identify Holocene tephras based on magnetite composition: a case study from the Sunwapta Pass area, Jasper National Park

1986 ◽  
Vol 23 (6) ◽  
pp. 804-812 ◽  
Author(s):  
A. B. Beaudoin ◽  
R. H. King

The magnetite composition from three sets of samples of Mazama, St. Helens set Y, and Bridge River tephras from Jasper and Banff national parks are used to test whether discriminant function analysis can unambiguously distinguish these tephras. The multivariate method is found to be very sensitive to the change in reference samples. St. Helens set Y tephra is clearly distinguished. However, discrimination between Mazama and Bridge River tephras is less distinct. A set of unknown tephras from the Sunwapta Pass area was used to test the classification schemes. Unknown tephras are assigned to different tephra types depending on which reference tephra set is used in the discriminant function analysis.

1980 ◽  
Vol 19 (04) ◽  
pp. 205-209
Author(s):  
L. A. Abbott ◽  
J. B. Mitton

Data taken from the blood of 262 patients diagnosed for malabsorption, elective cholecystectomy, acute cholecystitis, infectious hepatitis, liver cirrhosis, or chronic renal disease were analyzed with three numerical taxonomy (NT) methods : cluster analysis, principal components analysis, and discriminant function analysis. Principal components analysis revealed discrete clusters of patients suffering from chronic renal disease, liver cirrhosis, and infectious hepatitis, which could be displayed by NT clustering as well as by plotting, but other disease groups were poorly defined. Sharper resolution of the same disease groups was attained by discriminant function analysis.


Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Long Kim Pham ◽  
Bang Van Tran ◽  
Quy Tan Le ◽  
Trung Thanh Nguyen ◽  
Christian C. Voigt

This study is the first step towards more systematic monitoring of urban bat fauna in Vietnam and other Southeast Asian countries by collecting bat echolocation call parameters in Ho Chi Minh and Tra Vinh cities. We captured urban bats and then recorded echolocation calls after releasing in a tent. Additional bat’s echolocation calls from the free-flying bats were recorded at the site where we captured bat. We used the obtained echolocation call parameters for a discriminant function analysis to test the accuracy of classifying these species based on their echolocation call parameters. Data from this pilot work revealed a low level of diversity for the studied bat assemblages. Additionally, the discriminant function analysis successfully classified bats to four bat species with an accuracy of >87.4%. On average, species assignments were correct for all calls from Taphozous melanopogon (100% success rate), for 70% of calls from Pipistrellus javanicus, for 80.8% of calls from Myotis hasseltii and 67.3% of calls from Scotophilus kuhlii. Our study comprises the first quantitative description of echolocation call parameters for urban bats of Vietnam. The success in classifying urban bats based on their echolocation call parameters provides a promising baseline for monitoring the effect of urbanization on bat assemblages in Vietnam and potentially also other Southeast Asian countries.


2012 ◽  
Vol 60 (4) ◽  
pp. 387-404 ◽  
Author(s):  
Mohamed Agha ◽  
Ray E. Ferrell ◽  
George F. Hart

1967 ◽  
Vol 25 (2) ◽  
pp. 421-436
Author(s):  
Rayman W. Bortner

When statements of formal eligibility requirements fail to account for the characteristics of institutional populations, there is a tendency to resort to speculative explanations. This study examined some methods for empirical evaluations of these speculative notions. Univariate and step-down analyses did not aid in conceptualizing informal selection processes in this study; a discriminant function analysis seemed to provide an adequate approach to a synthesis. The method was illustrated by examining definable subsamples in a VA domiciliary which were compared with a non-institutional, community sample; means of the standardization samples for the tests used provided additional reference points for comparison. For these particular subsamples from this institution, alterations in self concept appeared to provide the single unifying theme which best integrated the diverse differences among the groups.


1982 ◽  
Vol 141 (1) ◽  
pp. 37-44 ◽  
Author(s):  
D. J. Pallis ◽  
A. B. Levey ◽  
J. S. Jenkins ◽  
P. Sainsbury ◽  
B. M. Barraclough

SummaryA discriminant function analysis was carried out to separate a sample of 75 suicides from a sample of 146 attempted suicides, on which comprehensive clinical and social data were recorded on an identical schedule. Two sets of discriminating items (with 18 and 6 variables) correctly classified 91 per cent and 83 per cent of the two samples in their respective groups. The results provide a basis for examining the usefulness of these variables as predictors of future suicide in people who have attempted suicide.


Sign in / Sign up

Export Citation Format

Share Document