scholarly journals Kozak's Variable-Exponent Taper Equation Regionalized for White Spruce in Alberta

2000 ◽  
Vol 15 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Shongming Huang ◽  
Daryl Price ◽  
Dave Morgan ◽  
Karl Peck
Keyword(s):  
Variable Exponent ◽  
Nonlinear Least Squares ◽  
White Spruce ◽  
P Value ◽  
Stem Form ◽  
Fit Statistics ◽  
Composite Equation ◽  
Overall Performance ◽  
Taper Equation ◽  
Residual Plots

Abstract Kozak's (1988) variable-exponent taper equation was estimated for white spruce by ecoregion of Alberta to reflect stem form variability among different ecoregions. Inspection of fit statistics and residual plots showed that the taper equation fitted the data quite well. Since the relative height constraint p had little impact on the overall performance of the taper equation, the optimum p value was estimated as a part of the nonlinear least squares procedures. Regional differences of the taper equation were examined and tested using the nonlinear extra sum of squares method. Ecoregions of similar taper relationships were combined to provide a composite equation. Performance of the taper equation in predicting diameter inside bark, total volume, and merchantable height was evaluated. Results indicated that the biases in predictions were small, both across different parts of the stem and for various tree sizes. West. J. Appl. For. 15(2):75-85.

scholarly journals Taper Equations for Five Major Commercial Tree Species in Manitoba, Canada

2007 ◽  
Vol 22 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Ryan J. Klos ◽  
G. Geoff Wang ◽  
Qing-Lai Dang ◽  
Ed W. East
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
White Spruce ◽  
Jack Pine ◽  
Volume Estimation ◽  
Trembling Aspen ◽  
Stem Form ◽  
Taper Equation ◽  
Taper Equations

Abstract Kozak's variable exponent taper equation was fitted for balsam poplar (Populus balsamifera L.), trembling aspen (Populus tremuloides Michx.), white spruce (Picea glauca [Moench] Voss), black spruce (Picea mariana [Mill.] B.S.P.), and jack pine (Pinus banksiana Lamb.) in Manitoba. Stem taper variability between two ecozones (i.e., Boreal Shield and Boreal Plains) were tested using the F-test. Regional differences were observed for trembling aspen, white spruce, and jack pine, and for those species, separate ecozone-specific taper equations were developed. However, the gross total volume estimates using the ecozone-specific equations were different from those of the provincial equations by only 2 percent. Although the regional difference in stem form was marginal within a province, a difference of approximately 7 percent of gross total volume estimation was found when our provincial taper equations were compared with those developed in Alberta and Saskatchewan. These results suggest that stem form variation increases with spatial scale and that a single taper equation for each species may be sufficient for each province.

scholarly journals The Effect of Crown Dimensions on Stem Profile for Dahurian Larch, Korean Spruce, and Manchurian Fir in Northeast China

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 398
Author(s):  
Amna Hussain ◽  
Muhammad Khurram Shahzad ◽  
Lichun Jiang
Keyword(s):  
Northeast China ◽  
Least Squares Method ◽  
Model Fitting ◽  
Nonlinear Least Squares ◽  
Dahurian Larch ◽  
Fit Statistics ◽  
Crown Length ◽  
Crown Shape ◽  
Natural Stands ◽  
Crown Dimensions

Crown architecture has long been evaluated for its impact on taper modeling. However, most of the research has focused on a limited number of crown dimensions. This study examined the effect of adding several crown dimensions in improving the diameter and volume estimates of Dahurian larch, Korean spruce, and Manchurian fir in northeast China. The crown dimensions included crown length, crown ratio, crown width, height to live crown base, diameter at the crown base, and crown shape. A well-known taper model of Clark et al. (1991) was fitted to the data of 276 trees from natural stands. To adjust the inherent autocorrelation in the data, we added a third-order continuous-time error structure in the model fit. Model fitting was carried out with the NLMIXED procedure (Non-linear Mixed Procedure), followed by the MODEL procedure of SAS using the generalized nonlinear least-squares method. Fit statistics and graphical assessments were used to evaluate the original and modified models. Above 98% of the total variance of d was explained by the models for all species. The addition of crown variables showed slight improvements for root mean square error (RMSE) values in the analyzed species. The RMSE plots indicated that the models with crown variables slightly improved the diameter and volume predictions for the species but only for the upper stem (>50%–90%). The study demonstrated that crown dimensions influence the stem taper, but the original model of Clark et al. (1991) reasonably realized that effect.

Abstract 13131: The Priority of Coronary Arteriography and Therapeutic Hypothermia After Return of Spontaneous Circulation in Patients With Out-of-hospital Cardiac Arrest. the Result of Sos-kanto 2012 Study

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shuichi Hagiwara ◽  
Kiyohiro Oshima ◽  
Masato Murata ◽  
Makoto Aoki ◽  
Kei Hayashida ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Therapeutic Hypothermia ◽  
Statistical Significance ◽  
Coronary Arteriography ◽  
Spontaneous Circulation ◽  
P Value ◽  
Return Of Spontaneous Circulation ◽  
Overall Performance ◽  
The Mean ◽  
Hospital Cardiac Arrest

Aim: To evaluate the priority of coronary angiography (CAG) and therapeutic hypothermia therapy (TH) after return of spontaneous circulation (ROSC) in patients with out-of-hospital cardiac arrest (OHCA). Patients and Methods: SOS-KANTO 2012 study is a prospective, multicenter (69 emergency hospitals) and observational study and includes 16,452 patients with OHCA. Among the cases with ROSC in that study, we intended for patients treated with both CAG and TH within 24 hours after arrival. Those patients were divided into two groups; patients in whom TH was firstly performed (TH group), and the others in whom CAG was firstly done (CAG group). We statistically compared the prognosis between the two groups. SPSS Statistics 22 (IBM, Tokyo, Japan) was used for the statistical analysis. Statistical significance was assumed to be present at a p value of less than 0.05. Result: 233 patients were applied in this study. There were 86 patients in the TH group (M/F: 74/12, mean age; 60.0±15.2 y/o) and 147 in the CAG group (M/F: 126/21, mean age: 63.4±11.1 y/o) respectively, and no significant differences were found in the mean age and M/F ratio between the two groups. The overall performance categories (OPC) one month after ROSC in the both groups were as follows; in the TH group, OPC1: 21 (24.4%), OPC2: 3 (3.5%), OPC3: 7 (8.1%), OPC4: 8 (9.3%), OPC5: 43 (50.0%), unknown: 4 (4.7%), and in the CAG group, OPC1: 38 (25.9%), OPC2: 13 (8.8%), OPC3: 15 (10.2%), OPC4: 18 (12.2%), OPC5: 57 (38.8%), unknown: 6 (4.1%). There were no significant differences in the prognosis one month after ROSC between the two groups. Conclusion: The results which of TH and CAG you give priority to over do not affect the prognosis in patients with OHCA.

scholarly journals Selection of mixed-effects parameters in a variable–exponent taper equation for birch trees in northwestern Spain

2013 ◽  
Vol 70 (7) ◽  
pp. 707-715 ◽  
Author(s):  
Esteban Gómez-García ◽  
Felipe Crecente-Campo ◽  
Ulises Diéguez-Aranda
Keyword(s):  
Variable Exponent ◽  
Mixed Effects ◽  
Birch Trees ◽  
Northwestern Spain ◽  
Taper Equation ◽  
Selection Of

What factors should be accounted for when developing a generalized taper function for black wattle trees?

2020 ◽  
Vol 50 (11) ◽  
pp. 1113-1123
Author(s):  
Mateus Niroh Inoue Sanquetta ◽  
John Paul McTague ◽  
Henrique Ferraço Scolforo ◽  
Alexandre Behling ◽  
Carlos Roberto Sanquetta ◽  
...  
Keyword(s):  
Solid Wood ◽  
Auxiliary Variables ◽  
Stem Form ◽  
Mixed Effect ◽  
Individual Tree ◽  
Taper Function ◽  
Black Wattle ◽  
Taper Equation ◽  
Total Tree ◽  
Mixed Effect Modeling

Taper functions have been widely used for various purposes. Several functions were developed and successfully applied; however, most of these functions fail to account for the influence of stand-level and individual-tree effects of variation on the stem profile. Hence, we aimed in this study to assess how these factors influence the stem profile of black wattle (Acacia mearnsii De Wild.) trees in southern Brazil. There is a notable necessity for developing a domestic market for black wattle solid wood. The database was composed of 218 black wattle trees at age 10 years distributed across the state of Rio Grande do Sul, Brazil. A dimensionally compatible taper equation combined with the mixed-effect modeling approach was used. Additionally, auxiliary variables were included to build a generalized taper function that explains stem form variations. In general, all variables showed a significant influence on the stem profile, except the crown ratio. The inclusion of relative spacing and tree hierarchical position in the taper function resulted in higher accuracy when estimating stem diameters and total tree volume. This study indicates that accounting for attributes at the stand and individual-tree levels may improve stem profile predictions, as well as the biological soundness of the taper function.

scholarly journals Cultural adaptation and the Clavien-Dindo surgical complications classification translated to Brazilian Portuguese.

2016 ◽  
Vol 43 (3) ◽  
pp. 141-148 ◽  
Author(s):  
LUIS FERNANDO MOREIRA ◽  
MARCELO CASTRO MARÇAL PESSÔA ◽  
DIEGO SACHET MATTANA ◽  
FERNANDO FERNANDES SCHMITZ ◽  
BERNARDO SILVEIRA VOLKWEIS ◽  
...  
Keyword(s):  
Surgical Complications ◽  
Brazilian Portuguese ◽  
P Value ◽  
Porto Alegre ◽  
Group I ◽  
Overall Performance ◽  
Group Ii ◽  
Level Of Experience ◽  
Different Levels

ABSTRACT Objective: to generate a translated and validated version of the Clavien-Dindo Classification of Surgical Complications (CDC) to Brazilian Portuguese (CDC-BR). Methods: the process of translation and adaptation followed the guideline of Beaton et al., 2000. We divided 76 participating surgeons, in different levels of experience, from the Department Surgery of the Hospital de Clínicas de Porto Alegre, into two groups: Group I applied the original version (CDC, n=36);r Group II used the modified version (CDC-BR, n=40). Each group classified 15 clinical cases of surgical complications. We compared performance between the groups (Mann-Whitney test) relating to the level of experience of the surgeon (Kruskal-Wallis test), considering p value <0.05 as significant. Results: the performance of the Group II (CDC-BR) was higher, with 85% accuracy, compared with 79% of Group I (CDC), p-value =0.012. The performance of the groups as for surgeons experience displayed p=0.171 for Group I, p=0.528 for Group II, and p=0.135 for overall performance. Conclusion: we produced a translated and validated version of the CDC for Brazilian Portuguese. The instrument will be a useful tool in the production of evidence on surgical outcomes.

Effects of adding tree, stand, and site variables to Kozak's variable-exponent taper equation

1994 ◽  
Vol 24 (2) ◽  
pp. 252-259 ◽  
Author(s):  
Charles K. Muhairwe ◽  
Valerie M. LeMay ◽  
Antal Kozak
Keyword(s):  
Variable Exponent ◽  
Lodgepole Pine ◽  
Site Class ◽  
Breast Height ◽  
Red Cedar ◽  
Taper Function ◽  
Quadratic Mean Diameter ◽  
Taper Equation ◽  
The Cost ◽  
Total Tree

Crown class, site class, and breast-height age were incorporated into Kozak's variable-exponent taper equation (A. Kozak. 1988. Can. J. For. Res. 18: 1363–1368) for three species: Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western red cedar (Thujaplicata Donn), and aspen (Populustremuloides Michx.). For lodgepole pine (Pinuscontorta Dougl.), crown ratio, breast-height age, and quadratic mean diameter were incorporated into Kozak's taper equation. The effects of adding these variables to the exponent part of the taper equation on the prediction abilities of the taper model were assessed for prediction of diameter inside bark along the stem, total tree volume, and tree merchantable height. It was found that apart from the use of crown ratio for lodgepole pine, the additional variables resulted in only marginal improvements to the published version of Kozak's taper function. Therefore, the cost of measuring these additional variables is not justifiable.

An Assessment of White Spruce Tree Volume Equations in Canada

1990 ◽  
Vol 66 (6) ◽  
pp. 600-605 ◽  
Author(s):  
R. T. Morton ◽  
T. I. Grabowski ◽  
S. J. Titus ◽  
G. M. Bonnor
Keyword(s):  
Goodness Of Fit ◽  
White Spruce ◽  
Volume Estimation ◽  
Estimation Methods ◽  
Single Model ◽  
Variable Model ◽  
Fit Statistics ◽  
Volume Equations ◽  
Better Than

In 1985, a survey of nine provinces and two territories was conducted to summarize operational tree volume estimation methods. Based on those results, six tree volume estimation functions were evaluated to answer the question: can a single model be used nation-wide for tree volume estimation? The six models were fitted to nation-wide data for 980 white spruce trees distributed nearly equally among the provinces and territories. Based on goodness of fit statistics and analysis of residuals, Schumacher's (1933) model and the Quebec combined variable model performed marginally better than the others. Further, the analyses did not reveal any significant differences between territories and provinces. It appears that any of these models could be applied to broad regions of Canada without suffering significant losses in accuracy.

Stem volume models with random coefficients for Pinus kesiya in Tanzania, Zambia, and Zimbabwe

2001 ◽  
Vol 31 (5) ◽  
pp. 879-888 ◽  
Author(s):  
Kalle Eerikäinen
Keyword(s):  
Variable Exponent ◽  
Generalized Least Squares ◽  
General Assumption ◽  
Random Coefficients ◽  
Stem Volume ◽  
Random Parameters ◽  
Pinus Kesiya ◽  
Taper Equation ◽  
Volume Models ◽  
Taper Models

The aim of the study was to estimate stem volume and taper models for Pinus kesiya (Royle ex Gordon). The volume function provides a simple prediction model for the stem volume. Taper models were developed for over- and under-bark diameters. The under-bark taper curve was determined with the variable-exponent taper equation, whereas the over-bark taper curve was derived from the predicted under-bark taper model using the variable-exponent form of the bark-thickness model. Because of the spatial correlation structures of the data, the general assumption of uncorrelated residuals did not hold. In addition, the models were assumed to contain random parameters that vary from stand to stand and from tree to tree. Therefore, the fixed and random parameters of the models were estimated with the generalized least squares technique. The results of the study show that the mixed models for stem volume and taper are more reliable volume and diameter predictors for P. kesiya than earlier taper and volume functions.

scholarly journals Employees’ Remuneration and Performance in Nigerian Breweries PLC

2019 ◽  
Vol 3 (1) ◽  
pp. 1-18
Author(s):  
Ogunyemi Joseph Kayode ◽  
Adewole Joseph Adeyinka ◽  
Akinde John Abiodun
Keyword(s):  
Employee Performance ◽  
Great Influence ◽  
P Value ◽  
Employee Productivity ◽  
Descriptive Research ◽  
Dependent Variables ◽  
Overall Performance ◽  
And Performance ◽  
The Relationship ◽  
Structured Questionnaire

This Study Aimed At Assessing The Effects Employees’ Remunerations On Productivity In The In Nigerian Breweries Plc. This Study Was Guided by three research objectives namely; to identify and discuss various forms of remuneration package in use, to examine the effects of remuneration packages on employees performance and to establish the relationship between improved remuneration and productivity in the Nigeria breweries. The study used descriptive research design. The population of this study consists of all staff working at the Nigerian Breweries PLC Ibadan. Sample of one hundred and twenty respondents were selected. A structured questionnaire was used to collect data from the respondents. The descriptive statistics employed include; frequencies and percentage and the relationship between independent and dependent variables were established using Pearson Product Moment Correlation coefficient with the use of (SPSS). The findings were presented using tables and figures. From the findings in the Hypothesis, the r= 0.509** was obtained. This is significant as the p-value greater than 0.05. This shows that there was a significant relationship between remuneration packages’ and employee performance. The findings also revealed that quick payment of remuneration has great influence on employees’ productivity. The study concluded that remuneration package such as overtime, constant remuneration payment, promotes morale and increase team cohesion. From this finding, it was recommended that, organization should continue providing security benefits to all employees, as it will positively influence employee productivity and raise overall performance in the all sectors. The study also recommends that the organization should continue providing health protection benefits to its employees since it will help them create a sense of loyalty and encourage their productivity in the economic sector. Organizations, especially Breweries PLC should review the current retirement package since a good retirement package will attract and retain employees in the organization and also improve their productivity.

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