scholarly journals Statistical analysis of the phytocoenose homogeneity. I. Distribution of the total species diversity and evenness indices as a homogeneity measure

2014 ◽  
Vol 54 (4) ◽  
pp. 449-463
Author(s):  
Anna J. Kwiatkowska ◽  
Ewa Symonides
Keyword(s):  
Statistical Analysis ◽  
Species Diversity ◽  
Normal Distribution ◽  
Forest Stand ◽  
Ground Layer ◽  
Spatial Distributions ◽  
Dwarf Shrubs ◽  
Empirical Distributions ◽  
Evenness Indices ◽  
Total Species

Homogeneity of the <em>Leucobryo-Pinetum</em> phytocoenose was assessed on the grounds of distributions of the total species diversity (H) and evenness e indices. In spite of the uniform physiognomy of the patch. caused by pure, even-aged, one-layered forest stand and apparent dominance of dwarf-shrubs in the ground layer, phytocoenose under study was heterogeneous. It resulted in the discrepancy between empirical distributions of H and e, and the normal distribution, as well as in the contagious spatial distributions of both indices.

scholarly journals Statistical analysis of the phytocoenose homogeneity. VI. Frequency distribution of the total species diversity and evenness indices as a function of the area size. Summing-up discussion

2014 ◽  
Vol 55 (1) ◽  
pp. 129-140
Author(s):  
Anna J. Kwiatkowska ◽  
Ewa Symonides
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Species Diversity ◽  
Normal Distribution ◽  
Coefficient Of Variation ◽  
Spatial Differentiation ◽  
Linear Functions ◽  
Frequency Distributions ◽  
Evenness Indices ◽  
Total Species

Homogeneity of the <em>Leucobryo-Pinetum</em> phytocoenose was assessed on the grounds of the agreement of frequency distributions of the total species diversity (A) and evenness (e) indices with the normal distribution. It was confirmed that: 1) empirical frequency distributions of H and e fitted the normal distribution only at some quadrat sizes; 2) values of mean, standard deviation and coefficient of variation were non-linear functions of the area size; 3) mean H and e values calculated for small quadrats (1 and 2 m<sup>2</sup>) differed from those calculated for average (4 and 8 m<sup>2</sup>) and large (16 and 32 m<sup>2</sup>) quadrats: 4) the area size at which frequency distributions of both indices were symmetrical determined the scale of spatial differentiation of the phytocoenose, under which it was homogeneous.

scholarly journals Fish species diversity in headwaters streams of Paraguay and Paraná Basins

2007 ◽  
Vol 50 (6) ◽  
pp. 1033-1042 ◽  
Author(s):  
Yzel Rondon Súarez ◽  
Sabrina Bigatão Valério ◽  
Karina Keyla Tondado ◽  
Alexandro Cezar Florentino ◽  
Thiago Rota Alves Felipe ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Environmental Factors ◽  
Fish Species ◽  
Total Species Richness ◽  
Paraná Basin ◽  
Parana Basin ◽  
Number Of Individuals ◽  
Total Species ◽  
Fish Species Diversity

The influence of spatial, temporal and environmental factors on fish species diversity in headwater streams in Paraguay and Paraná basins, Brazil was examined. A total of 4,605 individuals were sampled, distributed in 60 species. The sampled streams in Paraná basin presented a larger total species richness (42) than Paraguay streams (40). However the estimated richness was larger in Paraguay basin (53) than Paraná streams (50). The streams of Paraná basin had a greater mean species richness and evenness, while more individuals per sample were found in the Paraguay basin. Difference between the sub-basins were found in the Paraguay basin, while for the basin of Paraná, richness and evenness vary significantly between the sub-basins, but the number of individuals varied seasonally. The most important environmental factors to species diversity and abundance were altitude, water temperature, stream width and stream depth for both the basins.

scholarly journals Verification of normal distribution of welding distortions

2019 ◽  
Vol 91 (3) ◽  
Author(s):  
Damian Grzesiak ◽  
Jarosław Plichta
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Normal Distribution ◽  
Sheet Metal ◽  
Welding Process ◽  
Experiment Planning ◽  
Geometrical Parameters ◽  
Butt Welds ◽  
Planning Methods ◽  
Smirnov Test

The aim of this paper is to answer the question of the distribution of welding distortions. The MIG method was used to make 31 butt welds of 0H18N9 sheet metal, of 6 mm thickness and dimensions 150x350 mm. All joints are made with constant parameters of the welding process. Statistical analysis of the distribution and Kolomogorov-Smirnov test were used in this paper. On the grounds of the analysis it was proved that the distribution of welding deformations is a normal distribution. This justifies the use of experiment planning methods and the use of average values. The relatively high value of the standard deviation makes it necessary to take into account the geometrical parameters of the joint.

scholarly journals Volatility of Jakarta Islamic Index

2014 ◽  
Vol 6 (2) ◽  
pp. 207-222
Author(s):  
Hendri Tanjung
Keyword(s):  
Statistical Analysis ◽  
Normal Distribution ◽  
Stock Exchange ◽  
Daily Data ◽  
Using Data ◽  
Simple Statistical Analysis

Volatility of Jakarta Islamic Index. This study investigates the volatility of Jakarta Islamic Index (JII) in Jakarta Stock Exchange. The method that used in this research is used a simple statistical analysis. The normality of JII return is analyzed to answer whether the return of JII follows normal distribution. By using data of Jakarta Islamic Index from 2nd March 2009 to 30th October 2013 (1122 daily data), it is found that the distribution of return of JII is not normal, even the 5 sigma occurred. This means the return of Jakarta Islamic Index is much volatile than the theory predicted. This will make too much gain or loss in one day in the economy  DOI:10.15408/aiq.v6i2.1231

Bias in the published fossil record

Paleobiology ◽  
1978 ◽  
Vol 4 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Carl F. Koch
Keyword(s):  
Species Diversity ◽  
North America ◽  
Normal Distribution ◽  
Fossil Record ◽  
Geologic Time ◽  
Abundance Data ◽  
Significant Bias ◽  
Mollusc Species ◽  
Log Normal ◽  
Log Normal Distribution

The published fossil record has significant bias in favor of common and biostratigraphically important taxa when compared with data obtained from a thorough examination of several hundred collections from the Western Interior of North America. Overall species diversity is underestimated by a factor of 3 to 4, and bivalve and gastropod diversity by a factor of 5. The proportion of bivalves increased from 40 to 56% of the fauna, and the proportion of ammonites decreased from 28 to 18%. Thirteen published reports listed 65 species from 203 reported occurrences. Data from all sources showed 170 species for 1050 occurrences. By using abundance data and assuming a log-normal distribution, as many as 200 fossilizable mollusc species may have inhabited the Western Interior during the uppermost biozone of the Cenomanian. The importance of this study is that it quantifies the bias in the published fossil record relative to the potential fossil record for an unusually well studied interval of geologic time. The bias would be greater for less well studied strata.

scholarly journals Mendel’s pea crosses: varieties, traits and statistics

Hereditas ◽  
2019 ◽  
Vol 156 (1) ◽  
Author(s):  
T. H. Noel Ellis ◽  
Julie M. I. Hofer ◽  
Martin T. Swain ◽  
Peter J. van Dijk
Keyword(s):  
Statistical Analysis ◽  
Normal Distribution ◽  
Standard Normal Distribution ◽  
Data Sets ◽  
Crossing Experiments ◽  
Independent Variables ◽  
F2 Population ◽  
A Value ◽  
Segregation Ratios ◽  
Standard Normal

Abstract A controversy arose over Mendel’s pea crossing experiments after the statistician R.A. Fisher proposed how these may have been performed and criticised Mendel’s interpretation of his data. Here we re-examine Mendel’s experiments and investigate Fisher’s statistical criticisms of bias. We describe pea varieties available in Mendel’s time and show that these could readily provide all the material Mendel needed for his experiments; the characters he chose to follow were clearly described in catalogues at the time. The combination of character states available in these varieties, together with Eichling’s report of crosses Mendel performed, suggest that two of his F3 progeny test experiments may have involved the same F2 population, and therefore that these data should not be treated as independent variables in statistical analysis of Mendel’s data. A comprehensive re-examination of Mendel’s segregation ratios does not support previous suggestions that they differ remarkably from expectation. The χ2 values for his segregation ratios sum to a value close to the expectation and there is no deficiency of extreme segregation ratios. Overall the χ values for Mendel’s segregation ratios deviate slightly from the standard normal distribution; this is probably because of the variance associated with phenotypic rather than genotypic ratios and because Mendel excluded some data sets with small numbers of progeny, where he noted the ratios “deviate not insignificantly” from expectation.

Statistical Analysis of the Roundness Error Data

2012 ◽  
Vol 472-475 ◽  
pp. 869-874 ◽  
Author(s):  
Zhao Peng Dong ◽  
Li Ling Huang ◽  
Hai Ting Xie ◽  
Fu Gui Huang
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Statistical Analysis ◽  
Normal Distribution ◽  
Mathematical Knowledge ◽  
Measurement Data ◽  
Roundness Error ◽  
Main Emphasis ◽  
The Mathematical Model ◽  
Roundness Measurement

In order to simulate the actual roundness measurement accurately, must find the mathematical model of the actual roundness data, the paper’s main emphasis is doing statistical analysis by plenty of measurement data of roundness, using mathematical knowledge to prove that the actual characteristics of roundness parameters obey the normal distribution, and providing the basis for subsequent computer simulation in the future

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