• Title/Summary/Keyword: height-diameter prediction

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Allometric Equation for Biomass Determination in Chuqala Natural Forest, Ethiopia: Implication for Climate Change Mitigation

  • Balcha, Mecheal Hordofa;Soromessa, Teshome;Kebede, Dejene
    • Journal of Forest and Environmental Science
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    • v.34 no.2
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    • pp.108-118
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    • 2018
  • Biomass determination of species-specific in forest ecosystem by semi-destructive measures requires the development of allometric equations; predict aboveground biomass observable independent variables such as, Diameter at Breast Height, Height, and Volume are crucial role. There has not been equation of this type in mountain Chuqala natural forest. In this study two species namely, Hypericum revolutum Vahl. & Maesa lanceoleta Forssk. with tree diameter classes (15-20, 20.5-25, and 25.5-35 cm), with the purpose of conducting allometric equations were characterized. Each species assumed considered individually. For the linear model fit the two observed variable DBH, H and V were preferred for the prediction of above ground biomass. The best fitted model choose among the two formed model were identified using Akaike Information Criterion (AIC), and $R^2$ and adjacent $R^2$. Based on this the best fit model for Hypericum revolutum Vahl. was AGB=-681.015+4,494.06 (DBH), and for Maesa lanceoleta Forrsk. was. AGB=-936.96+5,268.92 (DBH).

ANALYSIS OF HEAT LOSS IN A CONSTANT VOLUME MICRO COMBUSTOR (초소형 정적 연소실의 열손실 분석)

  • Na, Han-Bee;Lee, Dae-Hoon;Kwon, Se-Jin
    • 한국연소학회:학술대회논문집
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    • 2002.11a
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    • pp.231-235
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    • 2002
  • A theoretical and experimental study on the combustion process in a constant volume micro combustor is described. Unlike in a macro scale constant volume combustor, the heat loss to the wall plays a major role in flame propagation in a micro micro combustor. In order to analyze the effect of heat loss on combustion phenomena, pressure transition from ignition was measured. A number of cylindrical micro combustors with different diameter and depth were used for experiment to study the effect of length scales and shape factor. The diameter of combustor ranged from 7.5mm to 22.5 mm and the height of cylinder was from 1mm to 4mm. Initial pressure was also varied for the experiment. The diagnostic methods were severely limited due to the size of the apparatus and uncertainties of certain quantities to be measured in a small-scale environment. An analytical method to derive physical quantities that are essential for performance prediction from the pressure measurements is described.

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Total Wood Volume Equations for Tectona Grandis Linn F. Stands in Gujarat, India

  • Tewari, Vindhya Prasad;Singh, Bilas
    • Journal of Forest and Environmental Science
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    • v.34 no.4
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    • pp.313-320
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    • 2018
  • Tectona grandis (teak) is one of the most important timber species worldwide and India is one of the major teak growing countries. Though some volume equations were developed for teak in India but the models developed were neither evaluated using robust statistical criteria nor validated. Hence, the objective of this study was to develop statistically tested appropriate volume equation to predict total wood volume (over- and under-bark) for teak trees in Gujarat. A total of 41 trees with age varying from 15 to 33 years and diameter at breast height (dbh) from 7.3 to 30.8 cm were felled for the purpose. Linear and non-linear equations were used to model the relationship of the total wood volume with respect to dbh and total height. The equations tested mostly fitted well to the data. Model evaluation and validation indicated that models should be calibrated with local data for greater accuracy in the prediction.

Critical heat flux in a CANDU end shield - Influence of shielding ball diameter

  • Spencer, Justin
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1343-1354
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    • 2022
  • Experiments were performed to measure the critical heat flux (CHF) on a vertical surface abutting a coarse packed bed of spherical particles. This geometry is representative of a CANDU reactor calandria tubesheet facing the end shield cavity during the in-vessel retention (IVR) phase of a severe accident. Deionized light water was used as the working fluid. Low carbon steel shielding balls with diameters ranging from 6.4 to 12.7 mm were used, allowing for the development of an empirical correlation of CHF as a function of shielding ball diameter. Previously published data is used to develop a more comprehensive empirical correlation accounting for the impacts of both shielding ball diameter and heating surface height. Tests using borosilicate shielding balls demonstrated that the dependence of CHF on shielding ball thermal conductivity is insignificant. The deposition of iron oxide particles transported from shielding balls to the heating surface is verified to increase CHF non-trivially. The results presented in this paper improve the state of the knowledge base permitting quantitative prediction of CHF in the CANDU end shield, refining our ability to assess the feasibility of IVR. The findings clarify the mechanisms governing CHF in this scenario, permitting identification of potential future research directions.

Modelling Stem Diameter Variability in Pinus caribaea (Morelet) Plantations in South West Nigeria

  • Adesoye, Peter Oluremi
    • Journal of Forest and Environmental Science
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    • v.32 no.3
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    • pp.280-290
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    • 2016
  • Stem diameter variability is an essential inventory result that provides useful information in forest management decisions. Little has been done to explore the modelling potentials of standard deviation (SDD) and coefficient of variation (CVD) of diameter at breast height (dbh). This study, therefore, was aimed at developing and testing models for predicting SDD and CVD in stands of Pinus caribaea Morelet (pine) in south west Nigeria. Sixty temporary sample plots of size $20m{\times}20m$, ranging between 15 and 37 years were sampled, covering the entire range of pine in south west Nigeria. The dbh (cm), total and merchantable heights (m), number of stems and age of trees were measured within each plot. Basal area ($m^2$), site index (m), relative spacing and percentile positions of dbh at $24^{th}$, $63^{rd}$, $76^{th}$ and $93^{rd}$ (i.e. $P_{24}$, $P_{63}$, $P_{76}$ and $P_{93}$) were computed from measured variables for each plot. Linear mixed model (LMM) was used to test the effects of locations (fixed) and plots (random). Six candidate models (3 for SDD and 3 for CVD), using three categories of explanatory variables (i.e. (i) only stand size measures, (ii) distribution measures, and (iii) combination of i and ii). The best model was chosen based on smaller relative standard error (RSE), prediction residual sum of squares (PRESS), corrected Akaike Information Criterion ($AIC_c$) and larger coefficient of determination ($R^2$). The results of the LMM indicated that location and plot effects were not significant. The CVD and SDD models having only measures of percentiles (i.e. $P_{24}$ and $P_{93}$) as predictors produced better predictions than others. However, CVD model produced the overall best predictions, because of the lower RSE and stability in measuring variability across different stand developments. The results demonstrate the potentials of CVD in modelling stem diameter variability in relationship with percentiles variables.

Stature estimation using the sacrum in a Thai population

  • Waratchaya Keereewan;Tawachai Monum;Sukon Prasitwattanaseree;Pasuk Mahakkanukrauh
    • Anatomy and Cell Biology
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    • v.56 no.2
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    • pp.259-267
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    • 2023
  • Stature is an essential component of biological profile analysis since it determines an individual's physical identity. Long bone dimensions are generally used to estimate the stature of skeletal remains; however, non-long bones such as the sternum, cranium, and sacrum may be necessary for some forensic situations. This study aimed to generate a regression equation for stature estimation of the skeletal remains in the Thai population. Ten measurements of the sacrum were measured from 200 dry sacra. The results revealed that the maximum anterior breadth (MAB) provided the most accurate stature prediction model among males (correlation coefficient [r]=0.53), standard error of estimation (SEE=5.94 cm), and females (r=0.48, SEE=6.34 cm). For the multiple regression model, the best multiple regression models were stature equals 41.2+0.374 (right auricular surface height [RASH])+1.072 (anterior-posterior outer diameter of S1 vertebra corpus [APOD])+0.256 (dorsal height [DH])+0.417 (transverse inner diameter of S1 vertebra corpus [TranID])+0.2 (MAB) with a SEE of 6.42 cm for combined sex. For males, stature equals 63.639+0.478 (MAB)+0.299 (DH)+0.508 (APOD) with a SEE of 5.35, and stature equals 75.181+0.362 (MAB)+0.441 (RASH)+0.132 (maximum anterior height [MAH]) with a SEE of 5.88 cm for females. This study suggests that regression equations derived from the sacrum can be used to estimate the stature of the Thai population, especially when a long bone is unavailable.

The Determination and Prediction of Pine to Oak Forest Succession in Sugadaira, Central Japan

  • Jun, Kato;Hayashi, Ichiroku
    • The Korean Journal of Ecology
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    • v.26 no.4
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    • pp.155-163
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    • 2003
  • In order to analyze the succession process from a pine forest to an oak forest, the tree growth of Pinus densiflora and Quercus mongolica ssp. crispula was monitored in a permanent quadrat for 23 years. The measurements were carried out for the stem diameter (DBH) of Pinus densiflora between 1977 and 1999 and for the height of Quercus mongolica ssp. crispula saplings between 1998 and 2000. The floristic composition and the locations of the individual P. densiflora and Q. mongolica ssp. crispula trees and saplings in the quadrat were recorded. P densiflora and Q. mongolica ssp. crispula individuals were randomly distributed within the quadrat. The relative growth rates (RGR) of DBH in P. densiflora were 0.085 $yr^{-1}$ for large trees and 0.056 $yr^{-1}$ for small trees in 1977. The RGR of height for Q. mongolica ssp. crispula was 0.122 $yr^{-1}$. The growth curve for DBH of P. densiflora was approximated by the logistic equation: $$DBH(t) = 30 {[1+1.16exp(-0.13 t)]}^{-1}$$ where DBH (t) the DBH (cm) in year t and t is the number of years since 1977. The growth in height of P. densiflora and Q. mongolica ssp. crispula was described by following equations: $$H (t) = 20.2 {[1+0.407exp(-0.137 t)]}^{-1} (P. densiflora)$$ $$H (t) = 30 {[1+20.7exp(-0.122 t)}^{-1} (Q. mongolica ssp. crispula)$$ Where H (t) is the tree height (m) in year t and t is the number of years since 1977 in P. densiflora and 1998 in Q. mongolica ssp. crispula. With these equations we predicted that the height of Q. mongolica ssp. crispula increases from 2 m in 1999 to 20 m in 2029. Therefore, Q. mongolica ssp. crispula and P. densiflora will be approximately the same height in 2029. The years required for succession from a pine forest to an oak forest are expected 33 with the range between 23 and 44 years.

A Study on the Planting Improvement and Original Landscape of Gyeonghoeru Area in Gyongbokkung Palace (경복궁 경회루 권역의 식생경관원형과 개선에 관한 연구)

  • Kim, Choong-sik;Jeong, Seul-ki
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.6
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    • pp.17-25
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    • 2018
  • This study was conducted to calculate the optimum height of trees, estimating a model for the prediction of tree growth for the landscape improvement of the Gyeonghoeru area. For the verification of measures for management, this study conducted a photographic survey of the Gyeonghoeru area and used the Pressler's formula to examine the growth rate of the pine forest of Mansesan. The results of the study are as follows. First, as a result of a field survey and landscape analysis, trees in the Gyeonghoeru area are large ones with more than a diameter at breast height of 30cm, except for weeping cherry trees and persimmon trees, and especially, it is necessary to manage them or replace with small trees through the landscape of Mansesan, which screens the landscape and pruning the trees in the terraced flower garden in the north. Second, as a result of a measurement of the growth rate of trees, for 10 years on average, they grew up by 14% in source diameter and 5% in tree height 5% in south of Mansesan and by 7% in source diameter and 2.4% in tree height in the north of Mansesan. Furthermore, when a simulation was prepared based on the measured growth rate of trees, it was found out that 20 years later, on the landscape on the second floor of Gyeonghoeru, the pine forest of Mansesan would cut off the skyline of Mt. Inwang-san. Third, this study analyzed a landscape improvement simulation and proposed a plan for tree management to take a view of the landscape of the Gyeonghoeru area. This study has a significance that it drew an efficient planting maintenance policy, considering the landscape characteristics of the Gyeonghoeru area.

Estimation of Site Index Equation for Pinus densiflora at Mt. Osu Region using Schnute Growth Function (Schnute 생장함수를 이용한 오서산지역 소나무림의 지위지수 추정)

  • Pyo, Jung-Kee;Lee, Young-Jin;Son, Yeong-Mo;Lee, Kyeong-Hak;Moon, Hyun-Shik
    • Journal of agriculture & life science
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    • v.43 no.4
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    • pp.9-14
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    • 2009
  • The purpose of this study was to estimate height growth pattern and to derive site index equation for Pinus densiflora grown at Mt. Osu region, Chungnam. A total of 21 repre - sentative trees from the established temporary plots around Boryeng and Cheongyang regions were destructively sampled to measure diameter, height, volume growth per 1-year interval by using of DTRS- 2000 measurement instrument. The Schnute growth function was select ed for height growth prediction using 181 height-age paired observations and derived anamorphic base age invariant site index curves (base index age 30 years). The fitted index and the asymptotic value of Schnute model indicated both 0.96 and 10.8 meter, respectively. The results suggested in this study could be very useful to understand the height growth pattern and productivity of the site quality on Pinus densiflora grown at Mt. Osu region, Chungnam.

A Study on Desirable Breast Type of Women in Their Twenties Based on the Ratio of Breast in Works of Art and Cup Design According to Breast Type (미술작품의 유방 실루엣 비율에 근거한 20대 여성의 바람직한 유방형태와 유형별 컵 설계에 관한 연구)

  • Sohn, Boo Hyun;Kweon, Soo Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.3
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    • pp.280-291
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    • 2013
  • This paper analyzes desirable breast types using measurements from 31 selected female subjects based on the ratio of breast in works of art and to design a brassiere cup design according to the breast type of 182 female subjects in their 20s. The subjects selected for this paper are somewhat larger than a previous study on aesthetically perfect breasts of foreigners according to chest breadth, center neck point to breast point, breast circumference, and breast volume. However, the aesthetic breasts of foreigners are larger than the subjects selected for this study according to chest depth, under-bust circumference, and bust point to bust point. Comparing various breasts types and aesthetic breasts, padding is necessary to complement the form of flat breasts to increase the volume and diameter. Brassiere cups for cone-shaped breasts should be designed to increase breast volume through an increase in nipple height. Hemisphere breasts should be designed to increase the overall volume-leaving diameter. Protrusion breasts should enhance the functions of aggregating and supporting without any increase or decrease of the breast volume. Drooping breasts require the ability to support a large volume to stabilize the breast. Subjects were selected depending on the ratio of breast silhouette as works of art and who have large breasts in disproportional to a slender trunk. Three items, the circumferential length of breast, height of the nipple, and the depth of inner breast using the anthropomorphic measurements of 182 subjects were measured through regression equations for breast volume. Breast volume = -394.86 + 27.52 ${\times}$ (the circumferential length of breast) + 18.73 ${\times}$ (height of the nipple) + 12.85 ${\times}$ (the depth of inner breast). Regression equations to extract the aesthetic breast volume in measurements irrelevant to breasts using the anthropomorphic measurements of 31 subjects were as follows. Aesthetic breast volume = -611.30 + 17.67 ${\times}$ (bust circumference) -24.29 ${\times}$ (under-bust circumference) + 16.31 ${\times}$ (neck point to breast point to waistline) + 22.83 ${\times}$ (bust breadth) + 12.22 ${\times}$ (waist depth) -8.34 ${\times}$ (interscye- front). This prediction equation is useful to develop a breast type brassiere pattern, complement breast enhancement surgery, or minimize the effect a mastectomy.