• Title/Summary/Keyword: Non-linear regression analysis

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Association of carotid atherosclerosis and obesity in type 2 diabetic patients (제2형 당뇨병 환자에서 비만과 경동맥 경화증과의 관계)

  • Gang, Se-Hun;Kim, Gyeong-Min;Jo, Dong-Hyeok;Gang, Ho-Cheol;Jeong, Dong-Jin;Jeong, Min-Yeong
    • Journal of Korea Association of Health Promotion
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    • v.4 no.1
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    • pp.12-27
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    • 2006
  • "본 논문은 대한내과학회지 2006년 제70권 제3호에 실렸던 논문으로 대한내과학회 편집위원회의 승인을 득하고 본 협회지에 게재함. Background : Diabetes mellitus is a major independent risk factor for atherosclerosis. In recent years non-invasive high resolution B-mode ultrasound methods have been developed to measure the intima-media thickness(IMT) of the carotid artery as an indicator for early atherosclerosis. Itis known that obesity plays a role in the development of type 2 diabetes and cardiovascular disease, and it has also been reported that not only the amount but also the distribution of body fat is important. This study investigated the relationship between obesity and the development of carotid atherosclerosis in type 2 diabetic patients. Methods: Carotid IMT was measured by ultrasound B-mode imaging in 144 patients with type 2diabetes mellitus. All subjects underwent assessment for the degree and distribution of obesity, the presence of coronary artery disease risk factors, and the presence of diabetic complications. Resuts: Carotid IMT was increased in the abdominal obese group defined by waist circurference. However, there was no significant difference in carotid TMT between the non-obese group and obese group as defined by body mass index, waist to hip ratio, and total body fat percent measured by bio electrical impedance analysis. There were positive correlations between carotid IMT and age, duration of diabetes, systolic blood pressure, and waist circumference. Multiple linear regression analysis revealed the variable that interacted independently with carotid IMT was age in type 2 diabetic patients. Carotid IMT was significantly increased in type 2 diabetic patients with macrovascular complications and microvascvlar complications .Conclusion: This study suggested that abdominal obesity rather than general obesity was associated with carotid atherosclerosis reflected by increment of carotid IMT in type 2 diabetic subjects.

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Possibility of the Nondestructive Quality Evaluation of Apples using Near-infrared Spectroscopy (근적외 분광분석법을 응용한 사과의 비파괴 품질 측정 가능성 조사)

  • Sohn, Mi-Ryeong;Kwon, Young-Kil;Lee, Kyung-Hee;Park, Woo-Churl;Cho, Rae-Kwang
    • Applied Biological Chemistry
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    • v.41 no.2
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    • pp.153-159
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    • 1998
  • A possibility of evaluation of the major internal quality factors-Brix, moisture contents, firmness and acid content in the Korean domestic 'Fuji'apple fruits by near-infrared reflectance spectroscopic (NIRS) methods were investigated. A multiple linear regression(MLR) analysis between the data obtained by physico- chemical analysis method using refractometer, freeze drier, texture analyzer and titrater and NIR spectral data was carried out to make a calibration. The standard error of prediction(SEP) of Brix, moisture, firmness and acid content were $0.50^{\circ}Brix,\;0.64%,\;0.14kg/cm^2$ and 0.07%. It is concluded that NIRS methods can be used to evaluate Brix and moisture contents of in a apple non-destructive and rapid way but the accuracy for determination of firmness and acid content was slightly low.

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A Prediction of Thermal Expansion Coefficient for Compacted Bentonite Buffer Materials (압축 벤토나이트 완충재의 열팽창계수 추정)

  • Yoon, Seok;Kim, Geon-Young;Baik, Min-Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.3
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    • pp.339-346
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    • 2018
  • A geological repository system consists of a disposal canister with packed spent fuel, buffer material, backfill material, and intact rock. The buffer is indispensable to assure the disposal safety of high-level radioactive waste. Since the heat generated from spent nuclear fuel in a disposal canister is released to the surrounding buffer materials, the thermal properties of the buffer material are very important in determining the entire disposal safety. Especially, since thermal expansion can cause thermal stress to the intact rock mass in the near-field, it is very important to evaluate thermal expansion characteristics of bentonite buffer materials. Therefore, this paper presents a thermal expansion coefficient prediction model of the Gyeongju bentonite buffer materials which is a Ca-bentonite produced in South Korea. The linear thermal expansion coefficient was measured considering heating rate, dry density and temperature variation using dilatometer equipment. Thermal expansion coefficient values of the Gyeongju bentonite buffer materials were $4.0{\sim}6.0{\times}10^{-6}/^{\circ}C$. Based on the experimental results, a non-linear regression model to predict the thermal expansion coefficient was suggested and fitted according to the dry density.

Relationship between local authority deprivation and activity limitation in adults aged 50 or over (지역 박탈수준과 중고령층의 활동제한의 연관성)

  • Yoon, Tae-Ho;Kim, Soo-Young;Yun, Mi-Sook;Moon, Kyung-Joo
    • Korean Journal of Health Education and Promotion
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    • v.32 no.2
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    • pp.27-37
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    • 2015
  • Objectives: As the increasing of the length of the lifespan, more recent policy interest are concerned with how many years of life are lived without functional disability or activity limitation. We investigated the relationship between deprivation and activity limitation at the 251 local authority level. Methods: The data were derived from the 2010 Census 10% sample data. Crude and age-standardized activity limitation rates by gender at the ages of 50 or over and deprivation index were calculated. Mapping and multiple linear regression analysis were applied to explore relationship between area activity limitation and area deprivation. Results: There were considerable differences in activity limitation rate across the 251 local authorities. Age-standardized activity limitation rate in both male and female were strongly associated with the level of area deprivation. Especially, low social class, male unemployment, or non-apartment residents at the local level were strong positive association with local authorities' age-standardized activity limitation. Conclusion: More policy attention is needed for tackling regional inequality in activity limitation among older adults.

The Evaluation of Compressive Strength in Cement Mortar using Electromagnetic Properties (전자기 특성을 이용한 시멘트 모르타르의 압축강도 평가)

  • Kim, Dong-Baek;Kwon, Seung-Jun
    • Journal of the Korean Society of Safety
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    • v.23 no.3
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    • pp.51-57
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    • 2008
  • NDT(Non-Destructive Testing Evaluation) using electromagnetic(EM) properties can be used for evaluation of physical performance in cement-based materials. In this study, a technique for strength evaluation in cement mortar is proposed through the measured EM properties(conductivity and dielectric constant). For this research, cement mortar specimens with 5 W/C ratios are made for evaluation of compressive strength and they are also utilized for tests of EM properties in the range of $0.2{\sim}20GHz$ frequency considering exposure condition and curing period. The averaged conductivity and dielectric constant in $5{\sim}20GHz$ frequency are reduced to $83{\sim}93%$ and $81{\sim}87%$, respectively with increasing water to cement ratios. Through the linear regression analysis, relationships between EM properties and results from the compressive strength are obtained, which shows higher correlated factor($0.93{\sim}0.94$) in the specimens exposed to room condition. The gradients in dielectric constant for strength results is measured to be higher than those in conductivity by $3.9{\sim}5.1$ times. The results from dielectric constant in room condition shows the most efficient relation for evaluation of strength.

Associations between Airborne Manganese and Blood Manganese in the Korean General Population according to KNHANES 2008-2009 (한국인의 혈중 망간농도와 공기중 망간농도의 관련성)

  • Jung, Kyung Sick;Lee, Jong Dae;Kim, Yong Bae
    • Journal of Environmental Science International
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    • v.22 no.12
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    • pp.1589-1598
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    • 2013
  • The objective of this study was to evaluate associations between airborne manganese and blood manganese in a general population of South Korean adults. The concentrations of airborne manganese in total suspended particulate (TSP) were calculated from data obtained from ambient air-monitoring stations (AAMSs) located in South Korea. Blood manganese data obtained Korean National Health and Nutrition Examination Survey (KNHANES) using a rolling sampling design involving a complex, stratified, multistage, probability cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. Airborne manganese geometric means was 46.10 $ng/m^3$, blood manganese geometric means were 1.19 ${\mu}g/d{\ell}$ for male and 1.40 ${\mu}g/d{\ell}$ for female. In multiple linear regression analysis of log transformed blood manganeseas a continuous variable on airborne manganese, after adjusting for covariates including gender, age, job, smoking and drinking status, education level, BMI (body mass index). Airborne manganese was positively associated with blood manganese with statistical significance. The present study confirms that airborne manganese is a possible contributor to the increase of blood manganese in the adult general population.

A Basic Study to Predict Solar Insolation using Meteorological Observation Data in Korea (국내 기상 측정결과를 이용한 일사량 예측 방법 기초 연구)

  • Hwangbo, Seong;Kim, Hayang;Kim, Jeongbae
    • Journal of Institute of Convergence Technology
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    • v.4 no.2
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    • pp.27-33
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    • 2014
  • To well design the solar energy system using solar energy, the correlation to calculate solar irradiation is basically needed. So, this study was performed to reveal the relationships between the solar irradiation and four meteorological observation data(dry bulb temperature, relative humidity, sunshine duration, and cloud cover) which are different from previous other researches. And then, we finally proposed the first order non-linear correlation from the measured solar irradiation using four meteorological observation data with MINITAB. To show the deviation of the solar irradiation between measured and calculated, this study compared using the daily total solar irradiance and the maximum peak value. From those results, the calculation error was estimated about maximum 25.4% for the daily total solar irradiance. The error of the solar irradiation between measured and calculated was made from the curve fitting error. So, solar irradiation prediction correlation with higher accuracy can be obtained using 2nd or higher order terms with four meteorological observation data.

Compression Splice Length in Concrete of 40 and 60 MPa Compressive Strengths (40, 60MPa 압축강도 콘크리트에서 철근 압축이음 길이)

  • Chun, Sung-Chul;Lee, Sung-Ho;Oh, Bo-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.571-572
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    • 2009
  • Current design codes regarding compression lap splice dose not utilize merits of the improved strength of ultra-high strength concrete. Especially, a compression lap splice can be calculated longer than a tension lap splice according to the codes because they do not consider effects of strength of concrete and transverse reinforcement. Design equation is proposed for compression lap splice in 40 to 70 MPa of compressive strength of concrete. The proposed equation is based on 51 specimens. Through two-variable non-linear regression analysis of measured splice strengths, a splice strength equation is derived, which is converted into a splice length equation.

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Prediction of Width-Direction Asymmetric Deformation Behavior and Its Setup Model in Plate Rolling (후판 압연공정에서 폭방향 비대칭 변형거동 예측 및 설정모델에 관한 연구)

  • Byon, Sang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.11
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    • pp.1437-1443
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    • 2011
  • Thick plates produced by the rolling process are used as the basic elements of ship structures. In this paper, we present a setup model for controlling the asymmetric factors causing plate bending in the width direction during plate rolling. A series of three-dimensional finite element analyses is conducted to predict the relationship between various asymmetric factors and plate bending. The setup model is developed by performing regression on the relationship to produce linear equations with several nondimensional parameters. The setup model is verified with a pilot rolling test in which variations in thickness and temperature differences in the width direction exist. The results show that the bending curvatures predicted by the model are in fairly good agreement with the measured results for those asymmetric factors.

Factors to Predict a Remission after Short-Term Pharmacotherapy in Korean Panic Disorder Patients (한국인 공황장애 환자에서 단기간 약물치료 후 관해 예측인자 연구)

  • Sim, Hyun-Bo;Kang, Eun-Ho;Yu, Bum-Hee
    • Anxiety and mood
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    • v.3 no.2
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    • pp.110-115
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    • 2007
  • Objective : The authors examined the treatment response and remission rates in patients with panic disorder after short-term pharmacotherapy in an effort to determine the factors that can be used to predict remission in Korean patients with panic disorder. Methods : Sixty-one patients with panic disorder were recruited for participation in this study. The psychological symptoms of the patients were measured using the HAMA, HAMD, STAIS, STAIT, ASI and API at baseline and after 3 months of pharmacotherapy. Results : Patients with panic disorder showed significantly lower scores on all psychological measures after 3 months of pharmacotherapy with paroxetine. The remission rate was 44.3%, and the response rate was 54.1%. The remitters showed significantly lower HAMD, HAMA, STAIS, STAIT, and ASI scores than the non-remitters. Linear regression analysis revealed that the baseline HAMA, HAMD, and ASI scores could be used to predict the remission rate after controlling for age, sex and agoraphobia. Conclusion : Compared with previous reports, our study showed a similar remission rate in Korean patients with panic disorder. Lower baseline levels of anxiety, depression, and anxiety sensitivity were found to be predictors of treatment remission in panic disorder.

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