Graphical analysis of stem taper in model building

1989 ◽  
Vol 19 (4) ◽  
pp. 522-524 ◽  
Author(s):  
R. L. Czaplewski
Keyword(s):  
Model Building ◽  
Graphical Analysis ◽  
Rate Of Change ◽  
Profile Model ◽  
Stem Taper ◽  
Join Points

When a stem-profile model is being built, a scatterplot of the empirical rate of change in diameter with respect to height provides useful information. It can indicate changes in stem taper, which provide tentative estimates for join points in segmented profile models. It can also help identify the desired form for profile models.

scholarly journals EVALUATION OF NON-LINEAR TAPER EQUATIONS FOR PREDICTING THE DIAMETER OF EUCALYPTUS TREES

2018 ◽  
Vol 42 (1) ◽  
Author(s):  
Guilherme Silverio Aquino de Souza ◽  
Diogo Nepomuceno Cosenza ◽  
Ana Carolina da Silva Cardoso Araújo ◽  
Lucas Veiga Ayres Pimenta ◽  
Ramon Barreto Souza ◽  
...  
Keyword(s):  
Variable Exponent ◽  
Linear Models ◽  
Mean Squared Error ◽  
Graphical Analysis ◽  
Statistical Validation ◽  
Absolute Deviation ◽  
Stem Taper ◽  
Non Linear ◽  
Identity Test ◽  
Taper Equations

ABSTRACT This study aims to evaluate non-linear stem taper models for predicting the pre-commercial diameter of eucalyptus trees and to analyze the effect of genotype on stem taper. The treatments comprise three different genotypes of Eucalyptus sp. in a 3 × 3 m plantation spacing. Seventy sample trees aged 10 years were felled for each treatment. The outside bark diameter measurements were taken at 0.5 m; 1.0 m; 1.5 m; 2.0 m, and then at intervals of 2.0 m till the top of the stem. Four non-linear models were evaluated, namely, the sigmoid model of Garay (1979), the variable exponent model of Kozak (1988), the segmented model of Max and Burkhart (1976), and the compatible model of Demaerschalk (1972). The performance of the models was assessed using the following statistical validation methods: correlation coefficient, standard error of estimate, mean bias, bias variance, root mean squared error, and mean absolute deviation. Graphical analysis of residues was used to evaluate the accuracy and precision of the estimates. Compared with other models, the variable exponent model of Kozak (1988) best described the stem profile, and predicted the total volume of the trees. The identity test showed that the stem profile is affected by the genotype.

The sense of presence in virtual environments:

2003 ◽  
Vol 15 (2) ◽  
pp. 69-71 ◽  
Author(s):  
Thomas W. Schubert
Keyword(s):  
Virtual Environments ◽  
Coding Theory ◽  
Model Building ◽  
Self Report ◽  
Survey Study ◽  
Spatial Presence ◽  
Component Structure ◽  
Sense Of Presence ◽  
Being There ◽  
Measure Sense

Abstract. The sense of presence is the feeling of being there in a virtual environment. A three-component self report scale to measure sense of presence is described, the components being sense of spatial presence, involvement, and realness. This three-component structure was developed in a survey study with players of 3D games (N = 246) and replicated in a second survey study (N = 296); studies using the scale for measuring the effects of interaction on presence provide evidence for validity. The findings are explained by the Potential Action Coding Theory of presence, which assumes that presence develops from mental model building and suppression of the real environment.

Theoretical, methodological and practical issues of choice models

2018 ◽  
Vol 1 (1) ◽  
pp. 21-37
Author(s):  
Bharat P. Bhatta
Keyword(s):  
Discrete Choice ◽  
Model Building ◽  
Estimation Method ◽  
Choice Models ◽  
Discrete Choice Models ◽  
Decision Makers ◽  
Model Formulation ◽  
Random Utility Maximization ◽  
The Relationship ◽  
Method Model

This paper analyzes and synthesizes the fundamentals of discrete choice models. This paper alsodiscusses the basic concept and theory underlying the econometrics of discrete choice, specific choicemodels, estimation method, model building and tests, and applications of discrete choice models. Thiswork highlights the relationship between economic theory and discrete choice models: how economictheory contributes to choice modeling and vice versa. Keywords: Discrete choice models; Random utility maximization; Decision makers; Utility function;Model formulation

Decreasing water pressure cues ‘bailout’ in seaweed-associated crustaceans

2020 ◽  
Vol 653 ◽  
pp. 121-129
Author(s):  
RB Taylor ◽  
S Patke
Keyword(s):  
Water Pressure ◽  
Rapid Change ◽  
Brown Seaweed ◽  
Model System ◽  
Rate Of Change ◽  
Suitable Habitat ◽  
Changing Light ◽  
Surface Increase ◽  
Reduced Water ◽  
Transparent Chamber

Small mobile crustaceans are abundant on seaweeds. Many of these crustaceans rapidly abandon their host if it is detached from the seafloor and floats towards the surface, but the trigger for this ‘bailout’ behaviour is unknown. We tested 2 potential cues, i.e. rapid change in light and rapid change in water pressure, using >1 mm epifauna on the brown seaweed Carpophyllum plumosum as a model system. Bailout occurred in response to reduced water pressure, but not to changing light, as (1) bailout occurred at similar rates in light and dark, (2) bailout occurred on the seafloor when water pressure was reduced within a transparent chamber by the equivalent of ~0.5 m depth or more, and (3) little bailout occurred when water pressure was held constant within the chamber while seaweeds were raised to the surface. Increase in pressure (simulating sinking) did not induce bailout. The rate of bailout increased with increasing magnitude of pressure reduction but was not influenced greatly by the rate of change of pressure within the range tested (up to an equivalent of 0.4 m depth s-1). The use of pressure rather than light as a cue for bailout is consistent with the need for seaweed-associated crustaceans to rapidly abandon a detached host and relocate to suitable habitat during both day and night.

Application of graphical analysis of taxonomical structure of diatom complexes in identification of critical conditions of the Neopleistocene lakes (on the example of Bibirevo section)

2019 ◽  
pp. 78-87
Author(s):  
Elena V. Bespalova
Keyword(s):  
Lake Sediments ◽  
Critical Points ◽  
Graphical Analysis ◽  
Volga Region ◽  
Critical Conditions ◽  
Ancient Lake ◽  
Diatom Complexes

Ancient lake sediments of Bibirevo section in the Yaroslavl and Kostroma Volga region are studied by means of graphical analysis of taxonomical structure of diatom complexes. This method allowed to record critical points (change of areas of stability) in the development of a Neopleistocene lake during the transition from stage to stage, as well as from phase to phase.

Causes of ecosystem transformations variability in lakes of the european part of Russia and Western Siberia (diatom analysis)

2019 ◽  
pp. 79-82
Author(s):  
Lev V. Razumovsky
Keyword(s):  
Western Siberia ◽  
Graphical Analysis ◽  
European Part ◽  
Analysis Method ◽  
Climatic Region ◽  
Diatom Analysis ◽  
Lake Ecosystems ◽  
Distinctive Features ◽  
European Part Of Russia

On the basis of author's graphical analysis method, the typification of lake ecosystems transformation scenarios depending on the size of lakes was carried out. It was confirmed that the type of transformation depends not only on size of the lake, but also on the landscape and climatic region in which it is located. The distinctive features of lake ecosystems transformation types in the European part of Russia and in Western Siberia were analyzed and compared.

Unconventional Play Fracture Characterization Through Orthorhombic Depth Model Building

2018 ◽  
Author(s):  
Guy Hilburn ◽  
Amit Pendharkar ◽  
William Keller ◽  
René Mott ◽  
Jorge Peinado ◽  
...  
Keyword(s):  
Model Building ◽  
Fracture Characterization
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