Comparaison des équations de régression. Application au cubage des arbres d'épinette noire.

1979 ◽  
Vol 55 (2) ◽  
pp. 54-56
Author(s):  
Richard Zarnovican
Keyword(s):  
Black Spruce ◽  
Regression Equation ◽  
Regression Equations ◽  
Soil Drainage ◽  
Total Height ◽  
Reduced Height ◽  
Bartlett Test ◽  
Single Regression

The Bartlett test, parallelism test and coincidence test were applied to compare four regression equations. The comparison dealt with regression equations for reduced height from total height of black spruce for four soil drainages, over till, in the High Subarctic of Quebec. It was found that form height can be extracted from total height by means of a single regression equation where soil drainage is good, moderately good or imperfect, but that a separate equation is required where drainage is poor.

An investigation of product form

1984 ◽  
Vol 14 (6) ◽  
pp. 768-774 ◽  
Author(s):  
P. Roebbelen ◽  
V. G. Smith
Keyword(s):  
Black Spruce ◽  
Jack Pine ◽  
Small Sample ◽  
Red Pine ◽  
Product Form ◽  
Regression Equations ◽  
White Pine ◽  
Total Height ◽  
Breast Height ◽  
Diameter Outside Bark

Product form (P) of a tree has been defined as the product of diameter-outside-bark at midheight above breast height (d) and total height (H) (P = d × H). It is used along with diameter breast height (D) in product form volume equations (VPF = f(P,D)) for estimating individual tree volumes. It is hypothesized that for each coniferous species, there exists some optimal height at which a diameter measurement can be taken and used in a product form term to estimate the inside-bark volume with minimum error. Regression equations and simpler expressions of the form V = D2 × H × F were developed for red pine (Pinusresinosa Ait.), white pine (Pinusstrobus L.), jack pine (Pinusbanksiana Lamb.), and black spruce (Piceamariana (Mill.) B.S.P.) using six upper diameter locations. The optimal location of the upper diameter was found to be 50% of the total height for red pine and white pine and 47% of total height for jack pine and black spruce. Product form is redefined as P = d* × H where d* = diameter-outside-bark at that average relative height on the tree where d* = (2 × V)/(D × H) as determined from a small sample of scaled trees, for each species and H = total height of tree.

THE MODEL FOR MANAGING INVESTMENTS IN THE MOSCOW ENVIRONMENT BASED ON A POWER REGRESSION EQUATION

2020 ◽  
Vol 2 (7) ◽  
pp. 91-99
Author(s):  
E. V. KOSTYRIN ◽  
◽  
M. S. SINODSKAYA ◽  
Keyword(s):  
Solid Waste ◽  
Influencing Factors ◽  
Pair Correlation ◽  
Approximation Error ◽  
Regression Equation ◽  
Regression Equations ◽  
The Impact ◽  
The Relationship ◽  
Average Approximation ◽  
Average Approximation Error

The article analyzes the impact of certain factors on the volume of investments in the environment. Regression equations describing the relationship between the volume of investment in the environment and each of the influencing factors are constructed, the coefficients of the Pearson pair correlation between the dependent variable and the influencing factors, as well as pairwise between the influencing factors, are calculated. The average approximation error for each regression equation is determined. A correlation matrix is constructed and a conclusion is made. The developed econometric model is implemented in the program of separate collection of municipal solid waste (MSW) in Moscow. The efficiency of the model of investment management in the environment is evaluated on the example of the growth of planned investments in the activities of companies specializing in the export and processing of solid waste.

Estimating mass of temperate and tropical pastures in the subtropics

1993 ◽  
Vol 33 (7) ◽  
pp. 865 ◽  
Author(s):  
WJ Fulkerson ◽  
K Slack
Keyword(s):  
Substantial Reduction ◽  
Ground Level ◽  
Regression Equations ◽  
Tropical Pastures ◽  
Senescent Leaf ◽  
Temperate Pastures ◽  
Second Year ◽  
Single Regression ◽  
Separate Regression ◽  
Subtropical Environment

The feasibility of estimating, with acceptable precision, temperate and tropical pasture mass in a subtropical environment was evaluated. For the tropical grasses kikuyu (Pennisetum clandestinum) and setaria (Setaria ancepts), 3 different pasture meters were calibrated against 1 of 3 dry matter (DM) estimates. Temperate pastures (predominantly Lolium perenne and Trifolium repens) were evaluated using the Ellinbank rising plate meter (RPMl) calibrated against DM to ground level. A single regression equation was developed for syegrass-white clover pasture from data pooled within season over first- and second-year swards. The s.e. of estimate (s.e.e.) for assessing tropical grass pasture mass using RPMl was similar to that for a heavier Ellinbank meter and substantially lower than that for the electronic pasture probe. Using RPMl, separate regression equations were required for early (November-February) and late (March-May) season determinations for both kikuyu and setaria. The regression equations were based on calibrations against shoot DM (>5 cm stubble height for kikuyu and 6 cm for setaria) and are only applicable to well-managed and highly utilised pastures. Calibrations of all pasture meters over all months to green DM (senescent leaf and stem removed) gave a lower s.e.e. than total DM (kikuyu 138 v. 177 kg DM/ha, n = 171; setaria 211 v. 224 kg DM/ha, n = 177) whilst shoot DM gave a more substantial reduction in s.e.e. (kikuyu 95 v. 147 kg DM/ha; setaria 140 v. 193 kg DM/ha).

scholarly journals Prediksi Tinggi Badan Ditentukan dari Panjang Rentang Lengan dan Panjang Telapak Kaki Pada Mongoloid Feminina Khususnya Etnis Jawa

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Nur Mujaddidah Mochtar
Keyword(s):  
Clinical Medicine ◽  
Pearson Correlation ◽  
Body Height ◽  
Regression Equation ◽  
The Body ◽  
Regression Equations ◽  
Foot Length ◽  
Arm Span ◽  
Knee Height ◽  
The Mean

Background: There are various circumstances where measurements are not actually possible, replacement parameters can be used to estimate body height. Many characteristics of body height measurement and how to measure it. These include anthropometric measurements that can be used for the identification of medicolegal-forensic processes. Body height in clinical medicine and in the field of scientific research can be easily estimated using various anthropometric parameters such as arm span, knee height, foot length and foot breadth, and others. The arm span and foot length has proved to be one of the most reliable predictors. This study was conducted to estimate of body height from arm span and foot length using the regression equation and to determine the correlation between the body height and arm span and foot length.Methods: This study was conducted at Universitas Muhammadiyah Surabaya with 182 Javanese female students. Stature, arm span and foot length measured directly using anthropometric technique and measuring tape. The data obtained were then analyzed with SPSS version 16. The regression equation was derived for the estimate of body height and the relationship between stature, arm span and foot length determined by the Pearson correlation.               Results: We found that the mean body height of Javanese women was 1534,45 ± 47,623  mm, mean of arm span 1543,25 ± 60,468 mm and the mean of foot length 226,14 ± 9,586 mm. The correlation between stature and arm span was positive and significant (r = 0,715  , p <0,05). The correlation between stature and foot length was positive and significant (r = 0,726 , p <0,05). The correlation between stature and arm span and foot length was positive and significant (r = 0,798, p <0,05).               Conclusion: Body height correlates well with the arm span and foot length so that it can be used as a reliable marker for high estimates using regression equations.

scholarly journals PROBLEMS FOR ANTI-CRISIS ANALYTICAL PROCEDURES OF FINANCIAL STABILITY OF TRADE ENTERPRISES

2020 ◽  
Author(s):  
Ludmila Anipko ◽  
◽  
Irina Klimovych ◽  
Keyword(s):  
Financial Stability ◽  
Regression Equation ◽  
Regression Coefficients ◽  
Regression Equations ◽  
Financial Condition ◽  
Financial Audit ◽  
Analytical Procedures ◽  
Financial Monitoring ◽  
Complex Indicators

Anti-crisis analytical procedures the financial stability of trade enterprises (hereinafter – AP FS) are part of the internal financial audit of economic activity. The system of financial monitoring is practically acceptable for the implementation of AP FS. The developed classification allows to determine the ability of the enterprise to implement AP FS. An analytical method has been developed that allows, based on the analysis of the financial condition and multivariate forecast, to develop measures to ensure the financial stability of the trade enterprise continuously. By interpolation, the study of the current financial situation, and extrapolation – a multivariate forecast, the numerical value of the integrated (complex) indicator that characterizes financial stability is determined by the regression equation, including factors listed in the classification, the significance of which is determined by regression equations. Based on the analysis of the numerical values of the regression coefficients, it is possible to determine the most important factors that affect the financial stability of trade enterprises, and those that have almost no effect on it. Components with significantly small numerical values of the regression coefficients can be generally discarded. This will reduce the number of indicators that affect financial stability and thus, you can reduce the number of components in the regression equation to the two three most important, which allows you to solve the problem of optimization. The expediency of using integrated and complex indicators is shown. The obtained results are only an information basis for the economic administration of the trade enterprise in making management decisions, the formation of long-term plans. The developed approaches to assessing the financial stability of enterprises are universal and can be used for enterprises in other sectors of the economy.

THE DIAPAUSE AND RELATED PHENOMENA IN GILPINIA POLYTOMA (HARTIG): IV. INFLUENCE OF FOOD AND DIAPAUSE UPON REPRODUCTIVE CAPACITY

1941 ◽  
Vol 19d (12) ◽  
pp. 417-436 ◽  
Author(s):  
M. L. Prebble
Keyword(s):  
Black Spruce ◽  
Dry Weight ◽  
Reproductive Capacity ◽  
Slight Reduction ◽  
Regression Equations ◽  
Physical Measurements ◽  
Influence Of Food ◽  
Practical Effect ◽  
Prolonged Diapause

Methods of sampling, determination of reproductive capacity, and analysis of data are described. Various physical measurements are positively correlated with reproductive capacity, but regression equations are unsatisfactory for estimation of fecundity outside of the population in which the relationships have been determined, due to variability in the degree of joint variation of size and fecundity under different feeding conditions. Field populations developed on white spruce are more fecund than those developed on black spruce; reductions of 30% or more may result from periodic food shortage.Reproductive capacity of females emerging over a period of three to five years in each of 20 populations, failed to show any consistent trend in relation to the diapause period. From this, and also from the slight reduction in eonymphal dry weight over extended intervals at favourable temperature, it is concluded that the destruction of eonymphal reserves during diapause proceeds very slowly and has no practical effect upon fecundity of females issuing after prolonged diapause.

scholarly journals Identifying the Driving Factors of Black Bloom in Lake Bay through Bayesian LASSO

2019 ◽  
Vol 16 (14) ◽  
pp. 2492 ◽  
Author(s):  
Wang ◽  
Wang ◽  
Cheng ◽  
Cheng
Keyword(s):  
Policy Development ◽  
Sediment Concentration ◽  
Ordinary Least Squares ◽  
Complex Problem ◽  
Regression Equation ◽  
Management Policy ◽  
Major Influence ◽  
Chaohu Lake ◽  
Regression Equations ◽  
Lasso Regression

Black blooms are a serious and complex problem for lake bays, with far-reaching implications for water quality and drinking safety. While Fe(II) and S(−II) have been reported as the most important triggers of this phenomenon, little effort has been devoted in investigating the relationships between Fe(II) and S(−II) and the host of potentially important aquatic factors. However, a model involving many putative predictors and their interactions will be oversaturated and ill-defined, making ordinary least squares (OLS) estimation unfeasible. In such a case, sparsity assumption is typically required to exclude the redundant predictors from the model, either through variable selection or regularization. In this study, Bayesian least absolute shrinkage and selection operator (LASSO) regression was employed to identify the major influence variables from 11 aquatic factors for Fe(II), S(−II), and suspended sediment concentration (SSC) in the Chaohu Lake (Eastern of China) bay during black bloom maintenance. Both the main effects and the interactions between these factors were studied. The method successfully screened the most important variables from many items. The determination coefficients (R2) and adjusted determination coefficients (Adjust R2) showed that all regression equations for Fe(II), S(-II), and SSC were in good agreement with the situation observed in the Chaohu Lake. The outcome of correlation and LASSO regression indicated that total phosphorus (TP) was the single most important factor for Fe(II), S(-II), and SSC in black bloom with explanation ratios (ERs) of 76.1% , 37.0%, and 12.9%, respectively. The regression results showed that the interaction items previously deemed negligible have significant effects on Fe(II), S(−II), and SSC. For the Fe(II) equation, total nitrogen (TN) × dissolved oxygen (DO) and chlorophyll a (CHLA) × oxidation reduction potential (ORP), which contributed 10.6% and 13.3% ERs, respectively, were important interaction variables. TP emerged in each key interaction item of the regression equation for S(−II). Water depth (DEP) × Fe(II) (30.7% ER) was not only the main interaction item, but DEP (5.6% ER) was also an important single factor for the SSC regression equation. It also indicated that the sediment in shallow bay is an important source for SSC in water. The uncertainty of these relationships was also estimated by the posterior distribution and coefficient of variation (CV) of these items. Overall, our results suggest that TP concentration is the most important driver of black blooms in a lake bay, whereas the other factors, such as DO, DEP, and CHLA act in concert with other aquatic factors. There results provide a basis for the further control and management policy development of black blooms.

Cross-Validation of Regression Equations to Predict Performance in a Pursuit Tracking Task

1978 ◽  
Vol 22 (1) ◽  
pp. 369-372
Author(s):  
Ricky E. Savage ◽  
Robert C. Williges ◽  
Beverly H. Williges
Keyword(s):  
Cross Validation ◽  
Regression Equation ◽  
Tracking Task ◽  
Training Condition ◽  
Regression Equations ◽  
Training Time ◽  
Pooled Data ◽  
Pursuit Tracking ◽  
Validation Procedure ◽  
Time To Learn

A double, cross-validation procedure was used to validate regression equations which predict training time to learn a two-dimensional pursuit tracking task. Motor skill and information processing tasks were used as predictors. The results yielded a reliable regression equation for each training condition, and these equations were quite similar in cross-validation. Subsequently, a regression equation based on pooled data from the original and cross-validation sample was calculated for each training condition. To establish the usefulness of a regression approach for selecting training strategies, these equations will be used in a future study where students will be matched, mismatched, and randomly assigned to various training alternatives.

Light threshold for optimal black spruce (Piceamariana) seedling growth and development under brush competition

1994 ◽  
Vol 24 (8) ◽  
pp. 1629-1635 ◽  
Author(s):  
Robert Jobidon
Keyword(s):  
Tree Growth ◽  
Black Spruce ◽  
Growth Increment ◽  
Height Growth ◽  
Light Interception ◽  
Stem Diameter ◽  
Tree Seedlings ◽  
Relative Growth ◽  
Competing Vegetation ◽  
Total Height

Light threshold is suggested as a method for quantifying brush competition in black spruce (Piceamariana (Mill.) B.S.P) plantations and predicting losses in tree growth as measured by the relative growth rate (RGR). The severity of the competing vegetation (expressed in terms of density and height) around 300 planted tree seedlings, and the growth status of the seedlings (expressed in terms of total height and current height growth increment), were analyzed simultaneously with multivariate analysis of variance (MANOVA), with one level of light quantity (photosynthetically active radiation) reaching the upper one-half of the tree seedlings as the predictor variable. This study showed that it is possible to establish a competitive status based on light interception, thus allowing a grouping of seedlings with similar growth characteristics and severity of competition. Canonical analysis showed that 60% of full sunlight reaching the upper one half of spruce seedlings can be defined as a threshold to significantly discriminate between stressed and unstressed tree seedlings, based on the above-mentioned variables and also based on spruce basal stem diameter. For spruce total height, current height increment, and basal stem diameter, significant differences were found between plots above and below this threshold, averaging 18.5, 44.7, and 23.2%, respectively. Measuring the intensity of light reaching the upper one half of the spruce seedlings also significantly explains spruce relative growth rates, expressed in terms of height growth increment and basal stem diameter growth increment over the following two growing seasons. The light threshold used in the MANOVA and the ANOVA showed significant differences between plots above and below the threshold, averaging 70 and 58% for spruce height and basal stem diameter RGRs, respectively. Instead of measuring competing vegetation variables and relative height of a crop species to infer light interception, this study demonstrated that a direct measure of light attenuation at the tree seedling level can be used to assess the competitive status and predict losses in tree growth for the period of time required by the seedlings to emerge from the vegetation cover. Moreover, this study demonstrated that canonical relations, rather than linear relations, explain the pattern of competition for light between young spruce seedlings and brushlike vegetation. The light threshold suggested in this study has potential for assessing interspecific competition problems in young black spruce plantations and is proposed as a tool to support a containment strategy of vegetation management.

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