scholarly journals Development of a Taper Equation for Teak (Tectona grandis L.f.) Growing in Western Thailand

2021 ◽  
Vol 19 (3) ◽  
pp. 176-185
Author(s):  
Thanapol Choochuen ◽  
◽  
Warong Suksavate ◽  
Ponthep Meunpong ◽  
◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Tectona Grandis ◽  
Graphical Analysis ◽  
Statistical Testing ◽  
Bark Thickness ◽  
Tropical Hardwood ◽  
Hardwood Species ◽  
Height Prediction ◽  
Taper Equation ◽  
Leave One Out

Teak is an important and valuable tropical hardwood species. In this study, we developed and evaluated suitable taper equations for teak growing in Western Thailand using a formulation of Goodwin cubic polynomial model combined with a bark thickness model. The best taper model calibration was selected based on goodness-of-fit and leave-one-out cross validation statistical testing. In total, 12 different model calibrations were tested, with Thong Pha Phum (TPP) 2 being the most suitable for teak in Western Thailand. The mean prediction error of three validation statistics: (prediction of diameter under bark given height; prediction of height given diameter under bark; and prediction of under bark volume given log length) were within 10% and the overall validation index was 5.454, which was the lowest when compared to other calibrations. A comparison of TPP 2 with a teak taper equation developed for Northern Thailand, using a graphical analysis of the stem shape and bark thickness, indicated that the teak trees growing in the two regions have similar stem shapes, but the trees in Western Thailand tend to have a thicker bark. These results will also help in further work as they indicate that bark thickness equations are particularly important.

scholarly journals THICKNESS ACCURACY OF TEAK BARK BY ARTIFICIAL INTELLIGENCE

FLORESTA ◽  
2019 ◽  
Vol 49 (3) ◽  
pp. 449
Author(s):  
Diogo Guido Streck Vendruscolo ◽  
Clebson Lima Cerqueira ◽  
Samuel de Pádua Chaves e Carvalho ◽  
Reginaldo Antonio Medeiros ◽  
Raiane Scandiane da Silva
Keyword(s):  
Artificial Intelligence ◽  
Tectona Grandis ◽  
Graphical Analysis ◽  
Tree Bark ◽  
Bark Thickness ◽  
Relative Height ◽  
Modeling Techniques ◽  
Input Variables ◽  
The One ◽  
Statistical Indicators

Estimates of tree bark thickness are fundamental for forest management, however, the degree of precision is conditioned to the adoption of efficient modeling techniques. The objective of this study was to evaluate and propose a model of artificial neural networks to estimate the thickness of the tree bark of Tectona grandis (Teak). The data originated from the measurement of 68 dominant trees, ranging in age from 6 to 33 years. The thickness of the bark was correlated with variables inherent to the tree, being: diameter in the different positions of the stem (di); diameter at 1.3 m height (dbh); total height (ht); relative height (hi_rel); and age (id). The trained networks were of the multilayer perceptron type, and a linear regression model was adjusted as a comparative support. The accuracy of the estimates was evaluated through statistical indicators and graphical analysis. The results showed a strong correlation between bark thickness and tree diameter, as well as relative height, with values above 0.70. Age also exerted a strong influence on the thickness of the bark of the trees. The artificial intelligence technique has demonstrated the potential for such application and the model proposed with the input variables: diameter, relative height and age was the one that presented the best statistical performance, and thus was the most suitable for predicting the bark in Teak trees.

scholarly journals Thermal properties of wooden based flask from tropical hardwood species

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Yekin Ogunsanwo ◽  
Ighoyivwi Onakpoma ◽  
Mary Korede
Keyword(s):  
Thermal Properties ◽  
Heat Loss ◽  
Tectona Grandis ◽  
Wood Waste ◽  
Heat Gain ◽  
Tropical Hardwood ◽  
Hardwood Species ◽  
Significant Difference ◽  
Thermos Flask ◽  
Albizia Saman

Abstract. Ogunsanwo OY, Onakpoma I, Korede M. 2020. Thermal properties of wooden based flask from tropical hardwood species. Asian J For 4: 61-64. Most materials used for production of conventional thermos flask (metals and plastics) are not environment friendly with particular concerns about plastic which are not biodegradable. Wood waste management is important in producing environmentally friendly materials and achieving sustainable development in forestry through wood waste utilization as thermos flask. This study was therefore conducted to investigate the thermal properties of wooden thermos flask (WTF) using tropical hardwood species with a view to promoting the use of greener technology. Offcuts of Tectona grandis and Albizia saman were used to produce 12 WTF of two thicknesses (11 mm and 12 mm), with a height of 10.5'' using bamboo as inner lining. The heat loss and heat gain by the wooden flasks and conventional flask were collected using a thermometer which was inserted into the cap of the flasks through a hole drilled in it, the hole was covered at intervals to prevent heat loss and heat gain from the opening. Data was collected every two hours for twelve hours. The study was laid out in a 2×2 factorial experimental in a completely randomized design. Data were analyzed using ANOVA at p=0.05. The highest heat loss (64.00ºC) after 12 hours was observed in Tectona grandis WTF with 11 mm and 12 mm while Albizia saman thermos flask with 12 mm thickness had the least heat loss (62.00ºC). Metallic flask lost only about 30.00 ºC of its heat content after 12 hours. The highest heat gain (28ºC) after 12 hours was observed in Tectona grandis WTF with 11mm and 12mm while Albizia saman WTF with 11 mm thickness had the least heat gain (25.67ºC). Heat gained by WTF was 28.00ºC and 25.83ºC for Tectona grandis and Albizia saman respectively after 12 hours while heat gain by the metallic flask after 12 hours was 18.00ºC. Species and thickness did not significantly affect heat loss and gain of thermos flask. Significant difference was however observed between the heat lost and gained by WTF and metallic flask. Wooden thermos flask still retained heat and prevented loss to a certain degree but technological improvement would perform better.

Destructive and non-destructive evaluation of seven hardwoods and analysis of data correlation

Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 951-956 ◽  
Author(s):  
Dhanya Ponneth ◽  
Anoop Elaveettil Vasu ◽  
Jayasree Chandramana Easwaran ◽  
Aadarsh Mohandass ◽  
Shakti S. Chauhan
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Penetration Depth ◽  
Physical And Mechanical Properties ◽  
Tectona Grandis ◽  
Strength Properties ◽  
Acacia Auriculiformis ◽  
Tropical Hardwood ◽  
Hardwood Species ◽  
Non Destructive

Abstract Wood physical and mechanical properties in seven tropical hardwood species viz., Acacia auriculiformis A. Cunn. ex Benth., Artocarpus hirsutus Lamk., Artocarpus heterophyllus Lamk., Swietenia macrophylla King, Xylia dolabriformis Benth., Hevea braziliensis (H.B.K.) M. A.), and Tectona grandis L.f. have been studied by means of destructive and non-destructive techniques (NDT). Mechanical strength properties and specific gravity were evaluated by conventional methods. NDT was carried out by a Pilodyn and Treesonic Microsecond Timer (TMT) to measure a steel pin penetration depth into wood and dynamic MOE, respectively. In focus was the question, whether NDT data are suitable predictors for physical and mechanical properties of the indicated hardwood species. Dynamic MOE obtained by TMT correlated strongly positive with all the strength properties studied, except shearing stress. TMT data also correlated very well to static bending MOE and MOR. A linear relationship was found between Pilodyn steel pin penetration depth and oven dry specific gravity in all the species. Both Pilodyn and TMT proved to be useful predictors of timber properties, and these instruments have a high potential for timber grading.

scholarly journals Fitting Terrestrial Laser Scanner Point Clouds with T-Splines: Local Refinement Strategy for Rigid Body Motion

2021 ◽  
Vol 13 (13) ◽  
pp. 2494
Author(s):  
Gaël Kermarrec ◽  
Niklas Schild ◽  
Jan Hartmann
Keyword(s):  
Point Cloud ◽  
Goodness Of Fit ◽  
Laser Scanner ◽  
Point Clouds ◽  
Statistical Testing ◽  
Computational Time ◽  
Terrestrial Laser Scanner ◽  
Reference Surface ◽  
Local Refinement ◽  
Surface Approximation

T-splines have recently been introduced to represent objects of arbitrary shapes using a smaller number of control points than the conventional non-uniform rational B-splines (NURBS) or B-spline representatizons in computer-aided design, computer graphics and reverse engineering. They are flexible in representing complex surface shapes and economic in terms of parameters as they enable local refinement. This property is a great advantage when dense, scattered and noisy point clouds are approximated using least squares fitting, such as those from a terrestrial laser scanner (TLS). Unfortunately, when it comes to assessing the goodness of fit of the surface approximation with a real dataset, only a noisy point cloud can be approximated: (i) a low root mean squared error (RMSE) can be linked with an overfitting, i.e., a fitting of the noise, and should be correspondingly avoided, and (ii) a high RMSE is synonymous with a lack of details. To address the challenge of judging the approximation, the reference surface should be entirely known: this can be solved by printing a mathematically defined T-splines reference surface in three dimensions (3D) and modeling the artefacts induced by the 3D printing. Once scanned under different configurations, it is possible to assess the goodness of fit of the approximation for a noisy and potentially gappy point cloud and compare it with the traditional but less flexible NURBS. The advantages of T-splines local refinement open the door for further applications within a geodetic context such as rigorous statistical testing of deformation. Two different scans from a slightly deformed object were approximated; we found that more than 40% of the computational time could be saved without affecting the goodness of fit of the surface approximation by using the same mesh for the two epochs.

Evaluation of Safety Performance Functions Based on Experimental Design Using a Cross-Validation Method

2017 ◽  
Vol 2636 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Jung-Han Wang ◽  
Mohamed A. Abdel-Aty ◽  
Jaeyoung Lee
Keyword(s):  
Goodness Of Fit ◽  
Cross Validation ◽  
Safety Performance ◽  
Major Road ◽  
Highway Safety Manual ◽  
Annual Average Daily Traffic ◽  
Minor Road ◽  
Safety Performance Functions ◽  
The One ◽  
Leave One Out

The Highway Safety Manual (HSM) Part C provides a series of safety performance functions (SPFs) for different roadway conditions. The SPFs suggested in the HSM are formulated on the basis of exposure variables: the logarithms of the annual average daily traffic (AADT) on the major road and on the minor road under the base condition. In this research, data from 7,802 intersections in Florida were collected and processed. These intersections were categorized into seven types based on area type (rural or urban), number of legs (three or four), and number of approaches controlled by stop signs. Twenty-two SPF formulations, including the one suggested by the HSM, were developed for each intersection type for examination of the goodness-of-fit measures of the SPFs. In addition, the goodness of fit of each model of the 22 SPFs in each category was examined with 10-fold leave-one-out cross-validation (LOOCV). With a comparison of the delta values generated with the LOOCV method, it is suggested that the SPF with the logarithm of the total entering vehicle volume and the ratio of the AADT on the minor road and the AADT on the major road are important. In addition, the SPFs with the AADT on the major road and the AADT on the minor road and their logarithmic transformations are also important. Therefore, it is suggested that the future HSM compare these two SPF formulations—as suggested in the current research, along with the original SPF formulation in the manual—and select the one with the best model fit on the basis of the delta value using LOOCV.

The Influence of Brand Extension Smartphone Samsung Galaxy Variable towards Brand Equity of Mother Brand of Samsung

2018 ◽  
Vol 3 (1) ◽  
pp. 06-15
Author(s):  
Sudaryanto Sudaryanto ◽  
Jery Courvisanos ◽  
Alif Puji Rahayu
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Brand Equity ◽  
Perceived Risk ◽  
Goodness Of Fit ◽  
Brand Extension ◽  
Jel Classification ◽  
Brand Extensions ◽  
Statistical Testing ◽  
Validity And Reliability

Objective - The purpose of this study is to identify the influence of similarity, reputation, perceived risk, and innovation as brand extensions of smartphones developed by Samsung, toward brand equity. Methodology/Technique - This study uses explanatory research. The population in this study consists of consumers of Samsung Galaxy mobiles for at least one month. Questionnaires were delivered to the respondents, after it had passed the validity and reliability tests. Following on from the the statistical testing, the data was analysed using a multiple linear regression. Then, the classical assumption test was conducted to determine the goodness of fit of the model. The data was collected using a questionnaire consisting of a closed statement, measured by a Likert Scale Findings - The results of this study show that similarity, reputation, perceived risk, and innovation as the variable dimensions have a significant effect on Brand Equity of Samsung Galaxy mobiles. Type of Paper: Empirical Keywords: Brand Extension; Brand Equity; Similarity; Reputation; Perceived Risk; Innovation; Explanatory Research. JEL Classification: M3, M30, M39.

Bark Thickness and Bark Volume in Southwestern Oregon Douglas-Fir

1990 ◽  
Vol 5 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Douglas A. Maguire ◽  
David W. Hann
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Bark Thickness ◽  
Breast Height ◽  
Taper Equation ◽  
Taper Equations ◽  
Height Predictions

Abstract A segmented polynomial taper equation for southwestern Oregon Douglas-fir (Pseudotsuga menziesii) predicts double bark thickness (dbt) at any point above breast height. Below breast height predictions assume conformity to a neiloid frustrum. The equations facilitate estimation of inside bark diameter (dib) given outside bark (dob) measurements. Bark volume and bark biomass can also be estimated when supplemented with existing dib taper equations developed for southwestern Oregon. West J. Appl. For. 5(1):5-8.

Developing an Automated Technique to Calibrate the AASHTOWare Pavement ME Design Software

2020 ◽  
Vol 2674 (9) ◽  
pp. 867-877
Author(s):  
Shuvo Islam ◽  
Avishek Bose ◽  
Christopher A. Jones ◽  
Mustaque Hossain ◽  
Cristopher I. Vahl
Keyword(s):  
Goodness Of Fit ◽  
Optimization Technique ◽  
Model Verification ◽  
Statistical Testing ◽  
P Value ◽  
State Highway ◽  
Global Calibration ◽  
Automated Technique ◽  
State Highway Agencies ◽  
Pavement Me Design

Many state highway agencies are in the process of implementing the AASHTOWare Pavement ME Design (PMED) software for routine pavement design. However, a recurring implementation challenge has been the need to locally calibrate the software to reflect an agency’s design and construction practices, materials, and climate. This study introduced a framework to automate the calibration processes of the PMED performance models. This automated technique can search PMED output files and identify relevant damages/distresses for a project on a particular date. After obtaining this damage/distress information, the technique conducts model verification with the global calibration factors. Transfer function coefficients are then automatically derived following an optimization technique and numerical measures of goodness-of-fit. An equivalence statistical testing approach is conducted to ensure predicted performance results are in agreement with the measured data. The automated technique allows users to select one of three sampling approaches: split sampling, jackknifing, or bootstrapping. Based on the sampling approach chosen, the automated technique provides the calibration coefficients or suitable ranges for the coefficients and shows the results graphically. Model bias, standard error, sum squared error, and p-value from the paired t-test are also reported to assess efficacy of the calibration process.

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