Towards a mathematical model of limestone pavement vegetation. III. Estimation of the determinants of species frequencies

1970 ◽  
Vol 48 (7) ◽  
pp. 1387-1404 ◽  
Author(s):  
G. A. Yarranton
Keyword(s):  
Mathematical Model ◽  
Multiple Regression ◽  
Two Phase ◽  
Surface Ph ◽  
Expected Frequency ◽  
Species Frequency ◽  
Independent Variables ◽  
The Mean ◽  
Species Frequencies

Models of the determination of the frequencies of 31 species of bryophytes, lichens, and algae in limestone pavement grikes were calculated by multiple regression. Independent variables were parameters of microclimate and surface pH. Percentages of variance accounted for varied from 14 to 72. In most cases the balance is attributable to replicate errors in the estimates of species frequencies and the abundance of zeros in the data. The models were used to predict species frequencies in other grikes, and in most species the mean difference between predicted and observed frequencies was less than 10%. Determinants of species frequency were found to be similar for species growing near the bottoms of the grikes but differed for those occurring near the tops.It is suggested that a two-phase analysis would be more informative than straightforward regression. In phase (a) the conditions under which the expected frequency is nonzero would be delimited; in phase (b) multiple regression would be performed on the observations falling within this region. This proposal is shown to be related to Hutchinson's concepts of fundamental and realized niches. It would also eliminate the problem of the multiple zero.

Non-invasive determination of the systolic peak-to-peak gradient in children with aortic stenosis: validation of a mathematical model

2000 ◽  
Vol 10 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Valter C. Lima ◽  
Evan Zahn ◽  
Christine Houde ◽  
Jeffrey Smallhorn ◽  
Robert M. Freedom ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Pulse Pressure ◽  
Linear Regression Analysis ◽  
Systolic Pressure ◽  
Pressure Gradients ◽  
Non Invasive ◽  
The Mean ◽  
Congenital Aortic Valvar Stenosis ◽  
Peak Gradient

AbstractDoppler derived systolic pressure gradients have become widely applied as noninvasively obtained estimates of the severity of aortic valvar stenosis. There is little correlation, however, between the Doppler derived peak instantaneous gradient and the peak-to-peak gradient obtained at catheterisation, the latter being the most applied variable to determine severity in children. The purpose of this study was to validate a mathematical model based on data from catheterisation which estimates the peak-to-peak gradient from variables which can be obtained by noninvasive means (Doppler derived mean gradient and pulse pressure), according to the formula: peak-to-peak systolic gradient=6.02+1.49*(mean gradient)−0.44*(pulse pressure). Simultaneous cardiac catheterization and Doppler studies were performed on 10 patients with congenital aortic valvar stenosis. Correlations between the gradients measured at catheter measured, and those derived by Doppler, were performed using linear regression analysis. The mean gradients correlated well (y=0.67 × + 11.11, r=0.87, SEE=6 mm Hg, p=0.001). The gradients predicted by the formula also correlated well with the peak-to-peak gradients measured at catheter (y=0.66 × + 14.44, r=0.84, SEE=9 mm Hg, p=O.002). The data support the application of the model, allowing noninvasive prediction of the peak-to-peak gradient across the aortic valvar stenosis.

A model for assessing interference.

1987 ◽  
Vol 33 (7) ◽  
pp. 1121-1123 ◽  
Author(s):  
M H Kroll ◽  
M Ruddel ◽  
D W Blank ◽  
R J Elin
Keyword(s):  
Experimental Design ◽  
Multiple Regression ◽  
Total Bilirubin ◽  
Direct Bilirubin ◽  
Analyte Concentration ◽  
Independent Variables ◽  
Analytical Interference

Abstract Most studies of analytical interference indicate the magnitude but not the type of interference. We developed a model for interference that assesses the magnitude of the following types of interference: independent of analyte concentration, dependent on analyte concentration, and a combination of the two. The experimental design for the model is an orthogonally arranged matrix with progressively increasing concentrations of analyte and interfering agent. Multiple regression with these independent variables (concentration of analyte, concentration of interfering agent, and the product of the two) is used to determine the magnitude, direction, and significance of each type of interference. Applying the model to study interference by hemoglobin with determinations of creatinine, direct bilirubin, and total bilirubin showed that hemoglobin interferes with determination of creatinine independent of the analyte concentration, interferes with total bilirubin dependent on the analyte concentration, and interferes with direct bilirubin by a combination of these two.

Acceptance towards Goods and Services Tax (GST) among local business communities

2017 ◽  
Vol 5 (4) ◽  
pp. 62
Author(s):  
Shahariah Asmuni ◽  
Sabariah Yusoff ◽  
Nur Syuhadah Mohd Ses
Keyword(s):  
Regression Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Business Community ◽  
Key Factors ◽  
Business People ◽  
Independent Variables ◽  
Goods And Services ◽  
The Mean ◽  
The Relationship

The Goods and Services Tax (GST) has been introduced in Malaysia to replace the Sales and Services Tax (SST) to improve the efficiency of indirect tax collection. However, its implementation has not been fully understood by business people.  This research aims to examine the key factors that have contributed to the level of acceptance towards GST among business communities in a local city, Johor Bharu. In this study, three variables were selected namely awareness, understanding and attitude. Using questionnaire as a research instrument, 100 sets of questionnaires were distributed. Multiple regression analysis was used to test the relationship among awareness, understanding and attitude with the level of acceptance among business communities towards GST. The results revealed that the mean score for all independent variables is moderate. Awareness and attitude were found to have significant impact on the level of acceptance among business community towards GST, while understanding is not significant. The business community in Johor Bahru shows a moderate or positive level of acceptance and attitude towards GST.

Analysis of the Mathematical Model of the Spray Dose Applied by the Field Sprayer Nozzles

2016 ◽  
Vol 20 (2) ◽  
pp. 71-79
Author(s):  
Karol Garbiak ◽  
Jan Jurga
Keyword(s):  
Mathematical Model ◽  
Angular Velocity ◽  
Forward Speed ◽  
Spray Application ◽  
Suggested Model ◽  
Independent Variables ◽  
Model Based ◽  
The Mathematical Model

AbstractThe article presents analysis of the mathematical model for determination of a momentary dose of spray applied by the field sprayer nozzles which move on the curve with the forward speed the value of which may differ from the speed accepted for regulation. Regulation speed and regulation dose, real forward speed of a sprayer, angular velocity during the curve movement, and the coefficient of the nozzle location towards the axis of the sprayer turn are independent variables in the suggested model. Based on the mathematical model, plots were drawn and analyses of relation of the spray dose to particular variables were carried out including inter alia, a repeated field spray, application of a dose which considerably differs from the regulation dose and diversity of the dose on the working width of the sprayer.

scholarly journals Faktor-faktor yang Mempengaruhi Kepatuhan Wajib Pajak Pedagang di PGS Surakarta

2021 ◽  
Vol 5 (1) ◽  
pp. 321
Author(s):  
Bima Setyawan ◽  
Anita Wijayanti ◽  
Rosa Nikmatul Fajri
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Multiple Regression ◽  
Random Sampling ◽  
Tax Compliance ◽  
Independent Variables ◽  
Tax Amnesty ◽  
Data Collection Technique ◽  
Data Analysis Methods

This study aims to examine the factors that have an influence on tax compliance in PGS Surakarta because tax compliance in Surakarta is still low, especially for MSMEs. The independent variables used in this study are variables of tax understanding, tax awareness, tax amnesty, taxpayer attitudes, and tax sanctions on tax compliance. The population of this study were all MSMEs in PGS Surakarta. Meanwhile, the determination of the number of samples in this study used random sampling with 60 respondents. The data collection technique used in this study is to use a questionnaire and data analysis methods using multiple regression with analysis tools using SPSS. The results of this study indicate that partially and simultaneously the variables of tax understanding and tax amnesty have an effect on MSME tax compliance in PGS Surakarta. Meanwhile, tax awareness variables, taxpayer attitudes, and tax sanctions have no effect on taxpayer compliance at PGS Surakarta.

scholarly journals Kepatuhan Wajib Pajak UMKM: Pengetahuan Pajak, Sanksi Pajak, dan Modernisasi Sistem

2020 ◽  
Vol 7 (01) ◽  
pp. 1-12
Author(s):  
Afuan Fajrian Putra
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Multiple Regression ◽  
Small And Medium Enterprises ◽  
Tax Compliance ◽  
Jel Classification ◽  
Independent Variables ◽  
Medium Enterprises ◽  
Data Analysis Methods

ABSTRACT       This research aims to examine the factors that have an influence on tax compliance. The independent variables used in this study are the variables of tax knowledge, tax sanctions, and tax modernization that will be tested partially and simultaneously on their influence on tax compliance. This study will examine these factors both simultaneously and partially. The population of this study is all MSMEs registered in the Office of Cooperatives, Small and Medium Enterprises, Sleman Regency. While the determination of the number of samples in this study using the Slovin formula and obtained the results of 100 respondents. However, not all data can be processed but as many as 85 respondents. Data collection techniques used in this study were to use a questionnaire and data analysis methods using multiple regression with analysis tools using SPSS version 16. The results of this study indicate that partially and simultaneously variables of tax knowledge, tax sanctions, and modernization have a significant effect on MSME tax compliance. ABSTRAK       Penelitian yang dilakukan ini bertujuan untuk menguji faktor-faktor yang memiliki pengaruh terhadap kepatuhan pajak. Variabel independen yang digunakan dalam penelitian ini adalah variabel pengetahuan pajak, sanksi pajak, dan modernisasi pajak yang keseluruhannya akan diuji pengaruhnya baik secara parsial maupun simultan terhadap kepatuhan pajak. Populasi dari penelitian ini  adalah seluruh UMKM yang terdaftar di Dinas Koperasi, Usaha Kecil, dan Menengah Kabupaten Sleman. Sedangkan penentuan jumlah sampel dalam penelitian ini menggunakan rumus Slovin dan didapatkan hasilnya sebanyak 100 responden. Akan tetapi tidak semua data dapat diolah melainkan sebanyak 85 responden. Teknik pengambilan data yang dilakukan dalam penelitian ini adalah menggunakan kuesioner dan metode analisis data menggunakan regresi berganda dengan alat analisis menggunakan SPSS versi 16. Hasil dari penelitian ini menunjukkan bahwa secara parsial dan simultan variabel pengetahuan pajak, sanksi pajak, dan modernisasi berpengaruh signifikan terhadap kepatuhan pajak UMKM. JEL Classification:  H25, D90

Carcass length in the bacon pig; its association with vertebrae numbers and prediction from radiographs of the young pig

1960 ◽  
Vol 2 (01) ◽  
pp. 59-65 ◽  
Author(s):  
J. W. B. King ◽  
R. C. Roberts
Keyword(s):  
Multiple Regression ◽  
Cervical Vertebrae ◽  
Lumbar Vertebrae ◽  
Regression Equation ◽  
Multiple Regression Equation ◽  
Large White ◽  
Independent Variables ◽  
Accuracy Of Prediction ◽  
Improved Accuracy

Vertebrae counts made on 504 Large White and 550 (Wessex × Large White) pigs showed an association with carcass length but not with other carcass traits. For each additional vertebra there was an increase in length of approximately 15 mm.Another group of 313 piglets from 36 litters were X-rayed at around 9 days of age in order to predict their ultimate carcass length. After correction for sex and variations in weight at slaughter it was found that the number of thoracic and lumbar vertebrae together accounted for 14% of the remaining variation in carcass length. Improved accuracy of prediction, accounting for 29% of the variation was obtained with a multiple regression equation using as independent variables: the skeletal length of the young pig as measured on its radiograph, its weight at birth and X-raying and the number of lumbar vertebrae. From measurements made on the carcass it i s suggested that X-raying of the bacon pig to measure the length of the first four lumbar vertebrae, would, in conjunction with an earlier determination of vertebrae number, enable a much improved prediction of carcass length to be made.The incidence of various vertebral variations is noted and in particular the occurrence of one pig with only six cervical vertebrae.

Direct Measurement of the Mean Flow Velocity Vector

1976 ◽  
Vol 98 (4) ◽  
pp. 736-739 ◽  
Author(s):  
R. H. Kirchhoff ◽  
R. M. Struziak
Keyword(s):  
Flow Velocity ◽  
Fundamental Frequency ◽  
Velocity Vector ◽  
Mean Flow ◽  
Two Phase ◽  
Response Equation ◽  
The Mean ◽  
Lock In ◽  
Mean Flow Velocity

The response of a single inclined rotating hot wire anemometer was analyzed. The mean flow anemometer response equation was expanded in a Fourier Series about the fundamental frequency of rotation. Utilizing the d-c level and the first two harmonics of the response it is possible to construct the mean flow velocity vector within a solid angle determined by the mounting angle of the wire. The rotating anemometer response was measured using the technique of two phase lock-in detection to determine the first two harmonics and their phases relative to the fundamental frequency of rotation. Determination of the mean flow velocity vector using this technique was found to be feasible.

Statistical hydromechanics of disperse systems. Part 2. Solution of the kinetic equation for suspended particles

1972 ◽  
Vol 52 (2) ◽  
pp. 345-355 ◽  
Author(s):  
Yu. A. Buyevich
Keyword(s):  
Kinetic Equation ◽  
Successive Approximations ◽  
Method Of Successive Approximations ◽  
Mean Flow ◽  
Time And Space ◽  
Two Phase ◽  
The Mean ◽  
Derivatives Of ◽  
Dynamic Variables

To solve the kinetic equation for particles of a monodisperse two-phase mixture the method of successive approximations is developed; this resembles in its main features the well-known Chapman-Enskog method in the kinetic theory of gases. This method is applicable for a mixture whose state differs slightly from the equilibrium, i.e., when time and space derivatives of the dynamic variables describing the mean flow of both phases of the mixture are sufficiently small. Accordingly, the solution obtained is valid when the time and space scales of the mean flow exceed considerably those for random pseudo-turbulent motion of particles and a fluid. The conservation equations for determination of all the dynamic variables are formulated in approximations which have the same meaning as those of Euler and Navier & Stokes in hydromechanics of one-phase media.

scholarly journals The Determination of Erythrocyte Folate Concentration Using a Two-Phase Ligand-binding Radioassay

Blood ◽  
1974 ◽  
Vol 43 (3) ◽  
pp. 437-443 ◽  
Author(s):  
Sheldon P. Rothenberg ◽  
Maria da Costa ◽  
John Lawson ◽  
Zoltan Rosenberg
Keyword(s):  
Ligand Binding ◽  
Lactobacillus Casei ◽  
Normal Subjects ◽  
Normal Serum ◽  
Serum Folate ◽  
Two Phase ◽  
Folate Concentration ◽  
Erythrocyte Folate ◽  
The Mean

Abstract The concentration of folate in erythrocytes was determined using a two-phase ligand-binding radioassay procedure described previously for measuring serum folate. The mean (± SD) folate concentration in erythrocytes of 20 normal subjects was 210 ± 57 ng/ml. In 12 patients clinically folate deficient who had normal serum B12 concentration, the mean (± SD) erythrocyte folate was 71 ± 39 ng/ml. Incubation of the lysed erythrocytes for 2 hr prior to boiling increased the radioassayable folate. The radioassayable folate decreased rapidly if the whole blood was stored at 4°C without ascorbate. Extracts of blood prepared with ascorbate could be stored at -20°C for several days. The radioassayable concentration of erythrocyte folate was similar to the values obtained using Lactobacillus casei when the concentration was 200 ng/ ml or less. With values higher by L. casei, the radioassayable folate was significantly lower even though the normal and folate-deficient groups were distinctly separated. This radioassay provides a rapid and reliable method of measuring erythrocyte folate, a parameter which reflects folate stores more reliably than serum folate concentration.

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