• Title/Summary/Keyword: Linear Regression Fit

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Cardiorespiratory Fitness Is Associated with Gait Changes among Firefighters after a Live Burn Training Evolution

  • Colburn, Deanna;Suyama, Joe;Reis, Steven E.;Hostler, David
    • Safety and Health at Work
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    • v.8 no.2
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    • pp.183-188
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    • 2017
  • Background: Recommendations have been proposed for minimum aerobic fitness among firefighters but it is unclear if those criteria relate to performance on the fireground. Less fit individuals fatigue more quickly than fit individuals when working at comparable intensity and may have gait changes, increasing risk of falls. We evaluated the effect of fatigue during a live burn evolution on gait parameters and functional balance comparing them to aerobic fitness levels. Methods: A total of 24 firefighters had gait and balance tested before and after a live burn evolution. Data were stratified by aerobic fitness of greater/less than 14 metabolic equivalents (METs). Results: Analysis of gait cycles measurements before and after the live burn evolution revealed that single leg stance, cycle, and swing time decreased (p < 0.05) but there were no differences in the other measures. There were no differences in time to complete the functional balance test, or errors committed before or after a live burn evolution. When firefighters were sorted by fitness level of 14 METs, there were no differences for errors or time before or after the live burn evolution. Balance data were analyzed using a linear regression. Individuals with lower fitness levels required more time to complete the test. Conclusion: A 14-MET criterion failed to distinguish gait or balance characteristics in this group. However, less fit firefighters did require more time to complete the balance test (p = 0.003). Aerobic fitness alone does not predict gait changes among firefighters following a live burn evolution but does appear to influence functional balance.

Studies on Relations between Goodness of Fit in Mother-children Temperament Interaction and Problem Behaviors of Children (모-자녀 기질 적합성과 자녀의 문제행동간의 관련성 연구)

  • Ha, Hyun-Yee;Jung, HaeRee;Lee, Soo Jin;Chae, Han
    • The Journal of Pediatrics of Korean Medicine
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    • v.27 no.2
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    • pp.11-19
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    • 2013
  • Objectives The purpose of this study was to identify the importance of goodness of fit in mother-child temperamental interaction (MCTI) and the child problem behaviors. Methods The behavior problem of 180 child outpatients from traditional Korean medical clinic was measured with Korean version of Child Behavior Checklists, and the temperament of child and their mother was measured with Junior Temperament and Character Inventory and Temperament and Character Inventory-Revised-Short. The MCTI was calculated as the difference of the temperament score between mother and child. The correlation and linear regression analysis was performed to examine the effects of temperament on Child Behavior Checklists. Results The MCTI on Harm-Avoidance was the significant factor for explaining the internalizing problem (B=-.154, t=-10.130, p<.001), externalizing problem (B=-.045, t=-3.340, p=.001) and total problem (B=-.298, t=-7.574, p<.001). We also confirmed that the temperament of mother and child significantly correlated with the child behavior problems as provided previously. Conclusions These results showed that the temperament interaction between mother and child is an important factor for predicting problem behaviors in child clinical sample. The goodness of fit in MCTI and problem behavior should be considered as pivotal element in traditional Korean pediatrics.

Water Quality Level of the Living Environmental Standards and Regression Analysis in the Major Tributaries of the Nakdong River (낙동강 주요 지류에서 생활환경 기준 수질 성분의 수질등급 및 회귀분석)

  • Kang, Dong-hwan;So, Yoon-hwan;Park, Kyeong-deok;Kim, Il-kyu;Kim, Byung-Woo
    • Journal of Environmental Science International
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    • v.28 no.3
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    • pp.357-369
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    • 2019
  • In this study, the water quality components (pH, BOD, COD, TOC, SS, DO, TP) and the water quality, observed for 10 years (2008~2017) in the five tributaries of the Nakdong River with the highest flow rates, were analyzed. Monthly levels of the water quality components were estimated and regression functions were used to quantitatively explain the changes in the BOD and COD components, with respect to the TOC components. The results of analyzing the water quality levels in terms of the living environmental standards show that the lowest water quality was observed midstream (ST-3) and the highest water quality was observed upstream (ST-1 and ST-2). The regression function was estimated to be a linear function in all five tributaries, and the goodness of fit of the function was high upstream (ST-2), midstream (ST-3), and downstream (ST-4). According to the regression analysis using the observation data from 2008~2017, we found that the consumption of dissolved oxygen increased with an increase in organic matter in the major tributaries of the Nakdong River.

Analysis on Cooling and Heating Performance of Water-to-Water Heat Pump System for Water Source Temperature (물-물 수온차 히트펌프 시스템의 원수온도에 따른 성능 특성 분석)

  • Park, Tae Jin;Cho, Yong;Park, Jin-Hoon
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.169.2-169.2
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    • 2010
  • The research assesses the performance of the water-to-water heat pump system installed in Cheongju water treatment plant for cooling and heating ventilation. In summer season monthly averaged COP is ranged from 3.85 to 4.56 according to the water source temperature, and the performance is increased as the raw water temperature is dropped. While, heating performance is increased for the high temperature water source, and the monthly averaged COP is changed from 2.92 to 3.82. The correlation of the water source temperature and the heat pump performance shows a linear tendency by the simple regression of average data. In heating, the COP of heat pump system linearly rises according to the water source temperature. In comparison, the COP in cooling linearly reduces as the raw water temperature is raised. The goodness of fit at the simple regression shows the coefficient of determination 82% in cooling, 46% in heating. The electric cost of water-to-water heat pump is reduced by 40% compared to that of air source heat pump.

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Quality Evaluation and Shelf-life of Dried Squid (마른 오징어의 품질평가 및 보존기간)

  • YOU Byeong-Jin;LEE Kang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.3
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    • pp.169-176
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    • 1988
  • In order to obtain the objective indices which can assess the quality and the shelf-life of dried squid, nonenzymatic browning, carbonyl value, trimethyl amine (TMA) and trimethyl amine oxide (TMAO) decrease and panel test were determined in dried squid at various water activity levels. When the data of nonenzymatic browning fit a zero order equation, $r^2$ value were more than 0.92 except aw 0.52 for 0.8241. Through variance analysis for the data of browning extent and TMAO decrease, the confidence limits of regression equation were $99\%$ and their limit values of shelf-life were shown 0.45390 O. D./g. solid and 190.322 g/g respectively. In case of TMAO, $r^2$ value was calculated more than 0.95. Linear regression equation for the correlation between browning data and average panel score was Y=0.6138-0.053X and its $r^2$ value was 0.9285. Also in TMAO decrease, the equation was InY=2.0314+0.08269x and $r^2$ value was 0.7854. The shelf-life, evaluated by nonenzymatic browning, TMAO decrease and panel test, was 110-170 days at aw 0.45-0.76 except aw 0.15.

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The impact of cardinal temperature variation on the germination of Haloxylon aphyllum L. seeds

  • Taghvaei, Mansour;Ghaedi, Masoumaeh
    • Journal of Ecology and Environment
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    • v.33 no.3
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    • pp.187-193
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    • 2010
  • Seed germination is a biological process that is affected by a variety of genetic and environmental factors. The cardinal temperature and thermal time are required for germination. The principal objective of this study was to identify and characterize variations in the base, optimum, and maximum germination temperatures of Haloxylon aphyllum L. from two seed sources, in order to establish models for use in predicting seeding dates. Mature H. aphyllum seeds were germinated at temperatures between 5 and $35^{\circ}C$. The germination behavior of H. aphyllum seeds to different temperature regimens in light was evaluated over a temperature range of $5-35^{\circ}C$ at intervals of $5^{\circ}C$. The rate of germination increased between base and optimum thermal conditions, and decreased between optimum and maximum thermal conditions; the germination rate varied in a linear fashion at both sub-optimal and supra-optimal temperatures. The linear regression fit the range of germination rates at $5^{\circ}C$ to $25^{\circ}C$ and $25^{\circ}C$ to $30^{\circ}C$, and thus the base temperature, optimum temperature, and maximum temperature for the germination of H. aphyllum were measured to be $0.6^{\circ}C$, $25.69^{\circ}C$, $37.90^{\circ}C$, and $1.76^{\circ}C$, $21.56^{\circ}C$, $37.90^{\circ}C$ for Qom and the Fars dune desert respectively.

Nonparametric estimation of conditional quantile with censored data (조건부 분위수의 중도절단을 고려한 비모수적 추정)

  • Kim, Eun-Young;Choi, Hyemi
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.2
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    • pp.211-222
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    • 2013
  • We consider the problem of nonparametrically estimating the conditional quantile function from censored data and propose new estimators here. They are based on local logistic regression technique of Lee et al. (2006) and "double-kernel" technique of Yu and Jones (1998) respectively, which are modified versions under random censoring. We compare those with two existing estimators based on a local linear fits using the check function approach. The comparison is done by a simulation study.

Comprehensive Residual Stress Distributions in a Range of Plate and Pipe Components

  • Lee Hyeong-Yeon;Kim Jong-Bum;Lee Jae-Han;Nikbin Kamran M.
    • Journal of Mechanical Science and Technology
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    • v.20 no.3
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    • pp.335-344
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    • 2006
  • A comprehensive review of through thickness transverse residual stress distributions in a range of as-welded and mechanically bent components made up of a range of steels has been carried out, and simplified generic transverse residual stress profiles for a plate and pipe components have been proposed. The geometries consisted of welded pipe butt joints, T-plate joints, tubular T-joints, tubular Y-joints and a pipe on plate joints as well as cold bent tubes and pipes. The collected data covered a range of engineering steels including ferritic, austenitic, C-Mn and Cr-Mo steels. Measured residual stress data, normalised with respect to the parent material yield stress, has shown a good linear correlation versus the normalised depth of the region containing the residual stress resulting from the welding or cold-bending process. The proposed simplified generic residual stress profiles based on the mean statistical linear fit of all the data provides a reasonably conservative prediction of the stress intensity factors. Whereas the profiles for the assessment procedures are fixed and case specific, the simple bilinear profiles for the residual stresses obtained by shifting the mean and bending stress from the mean regression line have been proposed and validated.

An Empirical Testing of a House Pricing Model in the Indian Market

  • HODA, Najmul;JAFRI, Syed Ashraf;AHMAD, Naim;HUSSAIN, Syed Mannawar
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.8
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    • pp.33-40
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    • 2020
  • The main aim of the study is to test a house pricing model by combining hedonic and asset-based pricing models. An understanding of the relationship between house pricing and its return (the rental income) helps to establish houses as a significant asset class. The model tested the relationship between house pricing (dependent variable) and the house attributes (independent variables) derived from Freeman's framework of housing attributes. This study uses a large data-set of 1,899 sample of new, high-end houses purchased between 2016 and 2019 collected from the national capital region of India (Delhi-NCR). The algorithm was built in R-Script, and stepwise multiple linear regression was used to analyze the model. The analysis of the model proves that the three significant variables, namely, carpet area, pay-off, and annual maintenance charges explain the price function. Further, the model is statistically fit. The major contribution of the study is to understand the key factors and their influence on the house pricing. The model will be helpful in risk assessment in the housing investment and enhance the chances of investment. Policy-makers can use information about the underlying valuation drivers of the house prices to stabilize the market and also in framing the tax policies.

Thin-layer Rewetting Equation for Short Grain Rough Rice (단립종(短粒種)벼의 박층흡습방정식(薄層吸濕方程式))

  • Jung, C.S.;Keum, D.H.;Park, S.J.
    • Journal of Biosystems Engineering
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    • v.12 no.2
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    • pp.38-43
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    • 1987
  • An experimental study was conducted to develop a thin-layer rewetting equation of short grain rough rice of Akihikari variety. Four thin-layer rewetting equations were experimentally determined from $25^{\circ}C$ to $45^{\circ}C$ and 70%RH to 85%RH conditions. Diffusion, Henderson, Page, and Thompson equations widely used as thin-layer drying equations were selected. Experimental data were fitted to these equations using linear regression analysis except diffusion equation. The diffusivity in the diffusion equation was determined by optimization method. Four equations were highly significant. In order to compare the goodness of fit of each equation, the error mean square of each equawas calculated. The diffusion model was not a very good model because the error mean square was very large. The other three models showed the same level or error mean square and could predict satisfactorily the rewetting rate or short grain rough rice.

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