• Title/Summary/Keyword: Mass regression

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A Study of Simple Rock Mass Rating for Tunnel Using Multivariate Analysis (다변량분석을 이용한 터널에서의 간편 RMR에 관한 연구)

  • 위용곤;노상림;윤지선
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.493-500
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    • 2000
  • Rock Mass Rating has been widely applied to the underground tunnel excavation and many other practical problems in rock engineering. However, Rock Mass Rating is hard to make out because it is difficult to estimate each valuation items through all kind of field situations and items of RMR have interdependence. So the experts of tunnel assessment have problems with rating rock mass. In this study, using multivariate analysis based on domestic data(1011EA) of water conveyance tunnel, we presented rock mass rating system which is objective and easy to use. The constituents of RMR are decided to RQD, condition of discontinuities, groundwater conditions, orientation of discontinuities, intact rock strength, spacing of discontinuities in important order. In each step, we proposed the best multiple regression model for RMR system. And using data which have been collected at other site, we examined that presented multiple regression model was useful.

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Predicting the resting metabolic rate of young and middle-aged healthy Korean adults: A preliminary study

  • Park, Hun-Young;Jung, Won-Sang;Hwang, Hyejung;Kim, Sung-Woo;Kim, Jisu;Lim, Kiwon
    • Korean Journal of Exercise Nutrition
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    • v.24 no.1
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    • pp.9-13
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    • 2020
  • [Purpose] This preliminary study aimed to develop a regression model to estimate the resting metabolic rate (RMR) of young and middle-aged Koreans using various easy-to-measure dependent variables. [Methods] The RMR and the dependent variables for its estimation (e.g. age, height, body mass index, fat-free mass; FFM, fat mass, % body fat, systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, and resting heart rate) were measured in 53 young (male n = 18, female n = 16) and middle-aged (male n = 5, female n = 14) healthy adults. Statistical analysis was performed to develop an RMR estimation regression model using the stepwise regression method. [Results] We confirmed that FFM and age were important variables in both the regression models based on the regression coefficients. Mean explanatory power of RMR1 regression models estimated only by FFM was 66.7% (R2) and 66.0% (adjusted R2), while mean standard errors of estimates (SEE) was 219.85 kcal/day. Additionally, mean explanatory power of RMR2 regression models developed by FFM and age were 70.0% (R2) and 68.8% (adjusted R2), while the mean SEE was 210.64 kcal/day. There was no significant difference between the measured RMR by the canopy method using a metabolic gas analyzer and the predicted RMR by RMR1 and RMR2 equations. [Conclusion] This preliminary study developed a regression model to estimate the RMR of young and middle-age healthy Koreans. The regression model was as follows: RMR1 = 24.383 × FFM + 634.310, RMR2 = 23.691 × FFM - 5.745 × age + 852.341.

Predictive Relationships of the Nonpoint Source Pollutant Loads with Stormwater Runoff Volumes based on the Various Regression Analyses (다양한 회귀분석을 통한 강우유출용적에 따른 비점오염부하량 예측방안)

  • Shin, Jiwoong;Gil, Kyungik
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.257-263
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    • 2011
  • This study analyzes the correlations between non-point sources and runoff to estimate non-point sources for effective management. From the monitoring results, the correlation factors among pollutant mass loading, EMC, total runoff volume and average flow are calculated. And using correlation factors, the most related two constituents are determined. Also the most appropriate regression between two constituents are determined. Pollutant mass loading and total runoff volume has the highest correlation. Also, compound regression is found to be the most appropriate regression. This shows that pollutant mass loading increases as total runoff volume increases. It is not continuous increase but has some pattern.

Estimating excess post-exercise oxygen consumption using multiple linear regression in healthy Korean adults: a pilot study

  • Jung, Won-Sang;Park, Hun-Young;Kim, Sung-Woo;Kim, Jisu;Hwang, Hyejung;Lim, Kiwon
    • Korean Journal of Exercise Nutrition
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    • v.25 no.1
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    • pp.35-41
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    • 2021
  • [Purpose] This pilot study aimed to develop a regression model to estimate the excess post-exercise oxygen consumption (EPOC) of Korean adults using various easy-to-measure dependent variables. [Methods] The EPOC and dependent variables for its estimation (e.g., sex, age, height, weight, body mass index, fat-free mass [FFM], fat mass, % body fat, and heart rate_sum [HR_sum]) were measured in 75 healthy adults (31 males, 44 females). Statistical analysis was performed to develop an EPOC estimation regression model using the stepwise regression method. [Results] We confirmed that FFM and HR_sum were important variables in the EPOC regression models of various exercise types. The explanatory power and standard errors of estimates (SEE) for EPOC of each exercise type were as follows: the continuous exercise (CEx) regression model was 86.3% (R2) and 85.9% (adjusted R2), and the mean SEE was 11.73 kcal, interval exercise (IEx) regression model was 83.1% (R2) and 82.6% (adjusted R2), while the mean SEE was 13.68 kcal, and the accumulation of short-duration exercise (AEx) regression models was 91.3% (R2) and 91.0% (adjusted R2), while the mean SEE was 27.71 kcal. There was no significant difference between the measured EPOC using a metabolic gas analyzer and the predicted EPOC for each exercise type. [Conclusion] This pilot study developed a regression model to estimate EPOC in healthy Korean adults. The regression model was as follows: CEx = -37.128 + 1.003 × (FFM) + 0.016 × (HR_sum), IEx = -49.265 + 1.442 × (FFM) + 0.013 × (HR_sum), and AEx = -100.942 + 2.209 × (FFM) + 0.020 × (HR_sum).

A Study on Relation between the Fuel Mass Flux and the Oxidizer Mass Flux with the Initial Port Diameter in Hybrid Rocket (하이브리드 로켓에서의 초기 포트직경을 고려한 산화제 유속과 고체연료 유속과의 관계에 관한 연구)

  • Lee, Jung-Pyo;Cho, Sung-Bong;Yoon, Sang-Kyu;Park, Su-Hayng;Song, Na-Young;Kim, Gi-Hun;Cho, Jung-Tae;Sung, Hong-Gye;Moon, Hee-Jang;Kim, Jin-Kon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.243-247
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    • 2007
  • Fuel mass flux was experienced with a function of the oxidizer mass flux using initial port area of solid fuel, in stead of regression rate correlation which shows combustion characteristic in hybrid propulsion. The burning rate could be easily obtained by using the oxidizer mass flux of initial port area without iteration, and fuel configuration could be designed simply. In this experiments PE was used as fuel, COX was used as oxidizer. A variation of mass flux of solid fuel with port area is considered by changing the burning time. In the case of approximate 0.5 for an exponent of oxidizer mass flux, using the fuel mass flux correlation is more suitable than regression rate correlation in hybrid propulsion.

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Estimation of Tunnel Convergence Using Statistical Analysis (통계처리를 활용한 터널 내공변위의 분석에 관한 연구)

  • 김종우
    • Tunnel and Underground Space
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    • v.13 no.2
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    • pp.108-116
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    • 2003
  • Measured convergence data of a tunnel were investigated by means of statistical and regression analysis, where the rock mass were mainly composed of andesite and granite. The rock mass around tunnel were classified by RMR method into five different ratings, and then convergence data which belong to individual ratings were statistically processed to find out the appropriate regression equations. Exponential equations were better coincided with measured data than logarithmic equations. As the number of rock mass rating was increased, the magnitude and standard deviation of convergence were increased. Final convergence data were also investigated to study the relevance with both maximum displacement rate and early measured convergence. Some brief results of their relevance are presented. For instance, the regression coefficient between final convergence and maximum displacement rate was turned out to be 0.87 for this studied tunnel.

Spontaneous Regression of Eyelid Histiocytoma in a Maltese Dog

  • Kim, Boyun;Lim, Jaegook;Shim, Jae-ho;Seo, Kangmoon;Kang, Seonmi
    • Journal of Veterinary Clinics
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    • v.39 no.3
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    • pp.121-125
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    • 2022
  • A 1-year-old neutered male Maltese dog was presented with a mass on the upper eyelid of the left eye (OS). A pinkish and alopecic mass was located in the nasal portion of the upper eyelid of OS. The mass was firmly attached to the eyelid and round-shaped with a diameter of 11 mm. Any spread to conjunctiva was not identified. On a cytological examination, cutaneous histiocytoma was confirmed, with the presence of small lymphocytes indicating later regression stage. The patient received no treatment and complete regression of the mass was verified 2 months later. The cytological examination was helpful for the diagnosis and staging of cutaneous histiocytoma. Canine eyelid histiocytoma can regress spontaneously, and thus medical or surgical treatment for removal should be considered carefully.

Biodynamic Characteristics of Korean Male in Twenties-Mass, Center of Mass and Moment of Inertia Characteristics of Body Segments (한국인 20대 청년 인체분절의 관성특성에 관한 연구)

  • 이영신;임현균;김철중
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.8
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    • pp.1952-1966
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    • 1994
  • The body segment parameters of twelve young male Korean were measured to compare with the results of foreign cadaver studies. A human body was assumed to have fourteen body segments. The mass of each segment was measured with a water immersion test and the mass center of a segment was determined on the balance platform by changing postures. In the case of Korean, because of the difference in body proportion, the mass center of whole-body is located further from the distal end of head(Korean : 44.9% vs. Caucasian : 41.2%), and the mass center of each segment also located in different proportional locations. The existing regression equations, which can estimate segment mass based upon the anthropometric dimensions, estimates segment mass (the mass of shank) for Korean with 13% error. Therefore, it is not recommended to estimate the mass, and the moment of inertia of body segment of Korean based on the existing equations. However, the density information of body constituents was similar enough to apply it to Korean density. It was validated by the comparison between the results of the direct immersion method and 3-dimensional volume reconstruction of segment form the cross sectional images of CT-scan. The average body density measured form twelve subjects was $1.035{\;}kg/m^3$ and showed deceasing trendency.

A Study on the Local Regression Rate of Solid Fuel in Hybrid Rocket (하이브리드 로켓에서의 고체연료의 국부 후퇴율에 관한 연구)

  • Kim, Soojong;Lee, Jungpyo;Kim, Gihun;Cho, Jungtae;Kim, Hakchul;Woo, Kyoungjin;Moon, Heejang;Sung, Hong-Gye;Kim, Jin-Kon
    • Journal of Aerospace System Engineering
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    • v.2 no.4
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    • pp.1-6
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    • 2008
  • In generally, the regression rate was expressed with average value and oxidizer mass flux in hybrid propulsion system. This can not represent the local value of regression rate along with oxidizer flow direction. In this study, experimental studies were performed with Separation method and Cutting method for measure local regression rate. In axial injection, the local regression rate decreases rapidly with axial location near entrance and increases with axial direction from the leading edge and the empirical formula for local regression rate with function of oxidizer mass flux and location was derived. Swirl injection regression rate has higher value at the leading edge of the fuel and comparatively uniform regression rate at the downstream. Overall regression rate of swirl injection is higher increased about 54 % than regression rate of axial injection.

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The Effect of Mass Media on Fashion Leadership of Make-up and Fashion Products (매스미디어 활용이 메이크업 및 패션제품의 유행선도력에 미치는 영향)

  • Kim, Yoon-Hee;Kim, Myung-Jin;Hwang, Jin-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.2 s.150
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    • pp.266-274
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    • 2006
  • This study aims to examine the effect of mass media on fashion leadership of make-up and fashion products. The subjects of the study were 168 women consumers who lived in Seoul. Data were collected during September in 2003. Statistical analyses used in this study were frequency, Cronbach's $\alpha$, ANOVA, Duncan test, t-test, and multiple regression. The results of this study were as follows; 1. As a result of multiple regression for the effect of mass media on fashion leadership of make-up, there was a significant effect of movies on fashion leadership of make-up. 2. As a result of multiple regression for the effect of mass media on fashion leadership of fashion product, there were significant effects of magazines, internet, and movies on fashion leadership of fashion product. 3. In regard to the effects of consumer characteristics on fashion leadership, there were significant effects of consumer characteristics on fashion leadership of make-up and fashion product.