• Title/Summary/Keyword: non-linear regression

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A Case-Control Study on Blood Lipids as a Risk Factor of Stroke (뇌졸중 위험지표로서의 혈중 지질에 대한 환자;대조군 연구)

  • Kim, Jung-Hyun;Kang, Kyung-Won;Yu, Byeong-Chan;Choi, Sun-Mi;Baek, Hye-Ki;Lim, Seung-Min;An, Jung-Jo;Seol, In-Chan;Kim, Yoon-Sik
    • The Journal of Internal Korean Medicine
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    • v.28 no.4
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    • pp.830-837
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    • 2007
  • Background and purpose : Stroke is one of the most deadly diseases and a leading cause of disability. Lipids confer an increased risk for cardiovascular morbidity and mortality. In spite of many studies on the relationship between stroke and lipids, their relationship is not clear. This study was undertaken to determine whether lipids were associated with stroke. Method : We compared the components of blood lipids between stroke patients group (n=217,Cases), non-stroke control group (n=160, Controls) and healthy control group without hypertension, diabetes mellitus, ischemic heart disease, or hyperlipidemia (n=140, Normals). These data were statically analyzed by general linear models and binary logistic regression analysis to get each adjusted odds ratio. Result : The results were as follows. The blood levels of total cholesterol (T-Chol), triglyceride (TG) and low density lipoprotein cholesterol (LDL-Chol) were significantly higher in patients of ischemic stroke, while the blood levels of T-Chol and LDL-Chol were significantly lower, and the blood levels of TG significantly higher in patients of hemorrhagic stroke. The blood level of high density lipoprotein cholesterol (HDL-Chol) was significantly lower in all cases. Conclusion : These results suggest that high TG and low HDL-Chol may be risk factors of hemorrhagic stroke and ischemic stroke, high T-Chol and LDL-Chol may be risk factors of ischemic stroke, and low T-Chol and LDL-Chol may be risk factors of hemorrhagic stroke in Koreans.

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Development of an Image Processing Algorithm for Paprika Recognition and Coordinate Information Acquisition using Stereo Vision (스테레오 영상을 이용한 파프리카 인식 및 좌표 정보 획득 영상처리 알고리즘 개발)

  • Hwa, Ji-Ho;Song, Eui-Han;Lee, Min-Young;Lee, Bong-Ki;Lee, Dae-Weon
    • Journal of Bio-Environment Control
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    • v.24 no.3
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    • pp.210-216
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    • 2015
  • Purpose of this study was a development of an image processing algorithm to recognize paprika and acquire it's 3D coordinates from stereo images to precisely control an end-effector of a paprika auto harvester. First, H and S threshold was set using HSI histogram analyze for extracting ROI(region of interest) from raw paprika cultivation images. Next, fundamental matrix of a stereo camera system was calculated to process matching between extracted ROI of corresponding images. Epipolar lines were acquired using F matrix, and $11{\times}11$ mask was used to compare pixels on the line. Distance between extracted corresponding points were calibrated using 3D coordinates of a calibration board. Non linear regression analyze was used to prove relation between each pixel disparity of corresponding points and depth(Z). Finally, the program could calculate horizontal(X), vertical(Y) directional coordinates using stereo camera's geometry. Horizontal directional coordinate's average error was 5.3mm, vertical was 18.8mm, depth was 5.4mm. Most of the error was occurred at 400~450mm of depth and distorted regions of image.

Morphological Factors and Cardiac Doses in Whole Breast Radiation for Left-sided Breast Cancer

  • Guan, Hui;Dong, Yuan-Li;Ding, Li-Jie;Zhang, Zi-Cheng;Huang, Wei;Liu, Cheng-Xin;Fu, Cheng-Rui;Zhu, Jian;Li, Hong-Sheng;Li, Miao-Miao;Li, Bao-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2889-2894
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    • 2015
  • Background: To investigate the impact of the breast size, shape, maximum heart depth (MDH), and chest wall hypotenuse (the distance connecting middle point of the sternum and the length of lung draw on the selected transverse CT slice) on the volumetric dose to heart with whole breast irradiation (WBI) of left-sided breast cancer patients. Materials and Methods: Fifty-three patients with left-sided breast cancer undergoing adjuvant intensity-modulated radiotherapy (IMRT) were enrolled in the study. The primary breast size and shape, MHD and DCWH (chest wall hypotenuse) were contoured on radiotherapy (RT) planning CT slices. The dose data of hearts were obtained from the dose-volume histograms (DVHs). Data were analyzed by one-way analysis of variance (ANOVA), Student's t-test and linear regression analysis. Results: Breast size was independent of heart dose, whereas breast shape, MHD and DCWH were correlated with heart dose. The shapes of breasts were divided into four types, as the flap type, hemisphere type, cone type and pendulous type with heart mean dose being $491.8{\pm}234.6cGy$, $752.7{\pm}219.0cGy$, $620.2{\pm}275.7cGy$, and $666.1{\pm}238.0cGy$, respectively. The flap type of breasts shows a strong statistically reduction in heart dose, compared to others (p=0.008 for V30 of heart). DCWH and MHD were found to be the most important parameters correlating with heart dose in WBI. Conclusions: More attention should be paid to the heart dose of non-flap type patients. The MHD was found to be the most important parameter to correlate with heart dose in tangential WBI, closely followed by the DCWH, which could help radiation oncologists and physicsts evaluate heart dose and design RT plan in advance.

Lifestyle Practice among Malaysian University Students

  • Al-Naggar, Redhwan Ahmed;Bobryshev, Yuri V.;Mohd Noor, Nor Aini Binti
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1895-1903
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    • 2013
  • Background: It is well established that a healthy lifestyle is of benefit in the prevention of diseases such as cancer and promotion of well-being. Therefore, the objective of this study was to determine lifestyle practice and associated factors among university students in Malaysia. Materials and Methods: A cross sectional study was conducted over six months from November 2011 until May 2012 among the students from the Management and Science University. This study was approved by its ethical committee, the students being explained the objective and invited to participate. A consent form was signed by all study participants. Questionnaire was distributed randomly to the students of the five faculties through their lecturers in different faculty. For univariate analysis t-test and ANOVA test were performed. Multiple linear regression used for multivariate analysis using SPSS 13.0. Results: A total number of 1100 students participated with a mean age of $22.1{\pm}2.21$ (SD) years. The majority were 22 years or younger (56.3%), female (54%), Malay (61.5%), single (92.3%), with family monthly income ${\geq}5000$ Ringgit Malaysia (41.2%). Regarding lifestyle, about were 31.6% smokers, 75.6% never drank alcohol and 53.7% never exercised. Multivariate analysis showed that age, sex, race, parent marital status, participant marital status, type of faculty, living status, smoking status, exercise, residency, brushing teeth, fiber intake and avoid fatty food significantly influenced the practice of drinking alcohol among university students (p=0.006, p=0.042, p<0.001, p=0.003, p=0.002, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p=0.003, p<0.001; respectively). It similarly showed that sex, race, parent marital status, participant marital status, monthly family income, exercise, residency, brushing teeth and fiber intake significantly influenced the practice of sun protection (p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p=0.017, p<0.001, p<0.001, p<0.001; respectively) and that age, sex, parent marital status, participant marital status, type of faculty, living status, exercise, taking non-prescribed medication, brushing the teeth, coffee consumption and fiber intake were significantly influenced the practice of fruits consumption (p=0.008, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p=0.002, p<0.001, P<0.001; respectively). Conclusions: This study showed a poor practice of healthy lifestyle among university students. Therefore universities should emphasize a healthy lifestyle in all faculties as a required subject. Socio-demographic characteristics significantly influenced practice and thus should be considered when planning preventive measures among university students. Frequent campaigns and educational seminars are to be encouraged.

Compression Lap Splice Length in Concrete of Compressive Strength from 40 to 70 MPa (40-70 MPa 콘크리트에서의 철근 압축이음 길이)

  • Chun, Sung-Chul;Lee, Sung-Ho;Oh, Bo-Hwan
    • Journal of the Korea Concrete Institute
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    • v.21 no.4
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    • pp.401-408
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    • 2009
  • A compression lap splice becomes an important issue due to development of ultra-high strength concrete. Current design codes regarding compression lap splice do 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 compressive strength of concrete and transverse reinforcement. This anomaly confuses engineers in practice. 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 conducted by authors. Basic form of the equation includes main parameters which are derived from investigating test results. Through two-variable non-linear regression analysis of measured splice strengths, a strength equation of compression lap splices is then derived. A specified splice strength is defined using a 5% fractile coefficient and a lap length equation is constructed. By the proposed equation, the anomaly of lap lengths in tension and compression is got rid of. In addition, the equation has a reliability equivalent to those of the specified strengths of materials.

Economic Threshold of Meloidogyne incognita for Greenhouse Grown Cucumber in Korea (오이 시설재배시 고구마뿌리혹선충의 경제적피해한계)

  • Kim, Dong-Geun;Lee, Joong-Hwan
    • Research in Plant Disease
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    • v.14 no.2
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    • pp.117-121
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    • 2008
  • To determine the economic threshold level of Meloidogyne incognita on cucumber in greenhouse conditions, cucumber seedlings(Cucumis sativa L. cv. 'Super Manchon') grafted on 'Jangsushintozoa'(Cucurbita maxima x Cu. moschata) were planted in wooden boxes($30{\times}40{\times}15cm,\;L{\times}W{\times}D$) under a plastic house in August 01 and harvested from Sep. 01-Oct. 30, 2006. The initial nematode population densities(Pi) in the wooden boxes were adjusted to 0, 10, 30, 100, 300, and 600 second-stage juveniles(J2)/100 $cm^3$ soil. The relationship of total fruit yield to Pi level could be adequately described by a linear regression equation, $Y=0.82-0.04{\cdot}Log_{10}$(Pi+1). Initial nematode densities(Pi) before planting in excess of 5 J2/1,000 $cm^3$ soil caused in total yields loss that is equivalent to the costs of granular nematicide application; Pi level in excess of 25 J2/1,000 $cm^3$ soil caused in total yields loss that exceed the costs for application of fumigants at current control costs. We propose two different management strategies depending on nematode densities, (i) application of non-fumigant granular nematicides for M. incognita Pi level of 5 J2/1,000 $cm^3$ soil and (ii) fumigant treatment with Pi level over 25 J2/1,000 $cm^3$ soil. Soil samples to determine population density of Meloidogyne spp. for advisory purposes should be taken several months before planting time, which allows a period of time enough for implementing management procedures.

A Study on Apparatus of Human Body Antenna for Mine Detection (지뢰탐지용 휴먼바디 안테나 장치 연구)

  • Kim, Chi-Wook;Koo, Kyong-Wan;Cha, Jae-Sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.269-272
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    • 2015
  • this is the study of the human body antenna device which can detect the powder in a 360-degree on(under) the ground whether it is metal or nonmetal using superhigh frequency RF beam equipped with the body. and it is able to transmit the data of the detection of the powder, battle combats can share that among them. with its flexible roof radial antenna structure, it emits the superhigh frequency RF beam to the front and flank multiply, preprocesses through the powder preprocessing part. and with the non-linear regression model algorism engine part, reflecting the attenuation characteristics depend on the delayed time of degree of the signal power which is received to the superhigh frequency RF beam. so it is able to detect the signal of the most likely mine or powder based on the degree of the answer signal power according to the delayed time of the superhigh frequency RF beam. also, it can detect the powder whether it is metal or nonmetal, mine, dud, VBIED. it can increase the chance of detection about 90% more than existing mine detector.

Flood stage analysis considering the uncertainty of roughness coefficients and discharge for Cheongmicheon watershed (조도계수와 유량의 불확실성을 고려한 청미천 유역의 홍수위 해석)

  • Shin, Sat-Byeol;Park, Jihoon;Song, Jung-Hun;Kang, Moon Seong
    • Journal of Korea Water Resources Association
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    • v.50 no.10
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    • pp.661-671
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    • 2017
  • The objective of this study was to analyze the flood stage considering the uncertainty caused by the river roughness coefficients and discharge. The methodology of this study involved the GLUE (Generalized Likelihood Uncertainty Estimation) to quantify the uncertainty bounds applying three different storm events. The uncertainty range of the roughness was 0.025~0.040. In case of discharge, the uncertainty stemmed from parameters in stage-discharge rating curve, if h represents stage for discharge Q, which can be written as $Q=A(h-B)^C$. Parameters in rating curve (A, B and C) were estimated by non-linear regression model and assumed by t distribution. The range of parameters in rating curve was 5.138~18.442 for A, -0.524~0.104 for B and 2.427~2.924 for C. By sampling 10,000 parameter sets, Monte Carlo simulations were performed. The simulated stage value was represented by 95% confidence interval. In storm event 1~3, the average bound was 0.39 m, 0.83 m and 0.96 m, respectively. The peak bound was 0.52 m, 1.36 m and 1.75 m, respectively. The recurrence year of each storm event applying the frequency analysis was 1-year, 10-year and 25-year, respectively.

Morphometric Characteristics and Fin Dimorphism between Male and Female on the Marine Medaka, Oryzias dancena

  • Im, Jae Hyun;Gil, Hyun Woo;Lee, Tae Ho;Kong, Hee Jeong;Ahn, Cheol Min;Kim, Bong Seok;Kim, Dong Soo;Zhang, Chang Ik;Park, In-Seok
    • Development and Reproduction
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    • v.20 no.4
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    • pp.331-347
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    • 2016
  • Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka, Oryzias dancena for their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were $L_{\infty}=30.2mm$, K=3.22/year, and ${\tau}_0=-0.05$. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA, P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka.

Determination of Hot Air Drying Characteristics of Squash (Cucurbita spp.) Slices

  • Hong, Soon-jung;Lee, Dong Young;Park, Jeong Gil;Mo, Changyeun;Lee, Seung Hyun
    • Journal of Biosystems Engineering
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    • v.42 no.4
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    • pp.314-322
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    • 2017
  • Purpose: This study was conducted to investigate the hot air drying characteristics of squash slices depending on the drying conditions (input air velocity, input air temperature, and sample thickness). Methods: The developed drying system was equipped with a controllable air blower and electric finned heater, drying chamber, and ventilation fan. Squash (summer squash called Korean zucchini) samples were cut into slices of two different thicknesses (5 and 10 mm). These were then dried at two different input air temperatures (60 and $70^{\circ}C$) and air velocities (5 and 7 m/s). Six well-known drying models were tested to describe the experimental drying data. A non-linear regression analysis was applied to determine model constants and statistical indices such as the coefficient of determination ($R^2$), reduced chi-square (${\chi}^2$), and root mean square error (RMSE). In addition, the effective moisture diffusivity ($D_{eff}$) was estimated based on the curve of ln(MR) versus drying time. Results: The results clearly showed that drying time decreased with an increase in input air temperature. Slice thickness also affected the drying time. Air velocity had a greater influence on drying time at $70^{\circ}C$ than at $60^{\circ}C$ for both thicknesses. All drying models accurately described the drying curve of squash slices regardless of slice thickness and drying conditions; the Modified Henderson and Pabis model had the best performance with the highest R2 and the lowest RMSE values. The effective moisture diffusivity ($D_{eff}$) changes, obtained from Fick's diffusion method, were between $1.67{\times}10^{-10}$ and $7.01{\times}10^{-10}m^2/s$. The moisture diffusivity was increased with an increase in input air temperature, velocity, and thickness. Conclusions: The drying time of squash slices varied depending on input temperature, velocity, and thickness of slices. The further study is necessary to figure out optimal drying condition for squash slices with retaining its original quality.