• 제목/요약/키워드: regression-analysis

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Correlation between menton deviation and dental compensation in facial asymmetry using cone-beam CT (Cone-beam CT를 이용한 안면비대칭자에서 이부편위에 따른 치성보상의 양상분석)

  • Park, Soo-Byung;Park, Jeong-Heuy;Jung, Yun-Hoa;Jo, Bong-Hye;Kim, Yong-Il
    • The korean journal of orthodontics
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    • v.39 no.5
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    • pp.300-309
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    • 2009
  • Objective: The purpose of this study was to evaluate the correlation between menton deviation and dental compensation in facial asymmetry. Methods: Tooth axis and distance of first molar and canine to the reference plane were investigated by cone-beam computerized tomography. The subjects consisted of 50 patients with asymmetric mandibles (male 21, female 29, mean age 24.3 years). Control groups were also assessed (male 11, female 9, mean age 25.6 years). Nine measurements (5 linear measurements and 4 angular measurements) were measured in order to evaluate the correlation between menton deviation and the linear and angular difference of first molar and canine in the deviated and none-deviated sides using the defined MPR images. The differences between deviated and non-deviated side, according to menton deviation, were statistically analyzed using stepwise multiple regression analysis. Results: From the result, Menton deviation was negatively correlated with mandibular first molar's angular measurement (${\Delta\angle}LM6$-Mn plane (dev.-ndev.)) and positively with maxillary fist molar's angular measurement (${\Delta\angle}UM6$-FH plane (dev.-ndev.)) (p < 0.01). Two angular measurements (${\Delta\angle}LM6$-Mn plane (dev.-ndev.), ${\Delta\angle}UM6$-FH plane (dev.-ndev.)) explained the variability in menton deviation with a significant $r^2$ value of 0.589. Conclusions: This study suggests that the tooth axis of upper and lower first molars leans towards the deviated side of Menton when there is mandibular asymmetry with Menton deviation.

Assessment of Carotid Geometry by Using the Contrast-enhanced MR Angiography (조영증강 MR 혈관 조영술을 이용한 경동맥 기하학의 평가)

  • Lee, Chung-Min;Ryu, Chang-Woo;Kim, Keun-Woo
    • Investigative Magnetic Resonance Imaging
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    • v.14 no.1
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    • pp.47-55
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    • 2010
  • Purpose : To evaluate the geometry of carotid artery by assessing the images of contrast-enhanced MR angiography (CE-MRA) and interrelationships between the geometry of carotid artery and clinical factors. Materials and Methods : 216 consecutive patients who performed supraaortic CE-MRA with fast spoiled gradient-echo imaging were included. Their medical records were reviewed for variable information including risk factors predictive of generalized atherosclerotic disease (age, hypertension (HTN), diabetes mellitus, hyperlipidema, and smoking), sex, body weight, height, and body mass index (BMI). We reviewed the CE-MRA with carotid origin (3 types), carotid artery tortuosity, angle of internal carotid artery bifurcation, the type of aortic arch branching, and the presence of the coiling of carotid artery. Results : Multinomial logistic regression analysis showed that significantly contributed clinical backgrounds for carotid origin were the age and the BMI. With an increase of age at 1, the probability that the type of carotid origin become from type 1 to type 2 was 0.9 times (p=0.004) in right carotid artery (RCA), 0.9 times (p = 0.031) in left carotid artery (LCA), 0.9 times that are likely to be type3 from type 2 (p<0.001) in RCA and 0.9 times in LCA (p=0.009). Increase in BMI at 1 increased odds of becoming type 2 as 1.1 times (p = 0.067) in RCA, 1.1 times (p=0.009) in LCA and increased chance of becoming type 3 as 1.2 times (p = 0.001) in RCA, 1.2 times (p=0.003) in LCA. Mean value of right and left carotid tortuosity were $240.9{\pm}69.0^{\circ}$and $154.4{\pm}55.0^{\circ}$, respectively. Conclusion : The BMI, age, sex and presence of HTN affects the geometry of carotid arteries, the site of origin and tortuosity of carotid artery specifically.

Quantitative Rainfall Estimation for S-band Dual Polarization Radar using Distributed Specific Differential Phase (분포형 비차등위상차를 이용한 S-밴드 이중편파레이더의 정량적 강우 추정)

  • Lee, Keon-Haeng;Lim, Sanghun;Jang, Bong-Joo;Lee, Dong-Ryul
    • Journal of Korea Water Resources Association
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    • v.48 no.1
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    • pp.57-67
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    • 2015
  • One of main benefits of a dual polarization radar is improvement of quantitative rainfall estimation. In this paper, performance of two representative rainfall estimation methods for a dual polarization radar, JPOLE and CSU algorithms, have been compared by using data from a MOLIT S-band dual polarization radar. In addition, this paper presents evaluation of specific differential phase ($K_{dp}$) retrieval algorithm proposed by Lim et al. (2013). Current $K_{dp}$ retrieval methods are based on range filtering technique or regression analysis. However, these methods can result in underestimating peak $K_{dp}$ or negative values in convective regions, and fluctuated $K_{dp}$ in low rain rate regions. To resolve these problems, this study applied the $K_{dp}$ distribution method suggested by Lim et al. (2013) and evaluated by adopting new $K_{dp}$ to JPOLE and CSU algorithms. Data were obtained from the Mt. Biseul radar of MOLIT for two rainfall events in 2012. Results of evaluation showed improvement of the peak $K_{dp}$ and did not show fluctuation and negative $K_{dp}$ values. Also, in heavy rain (daily rainfall > 80 mm), accumulated daily rainfall using new $K_{dp}$ was closer to AWS observation data than that using legacy $K_{dp}$, but in light rain(daily rainfall < 80mm), improvement was insignificant, because $K_{dp}$ is used mostly in case of heavy rain rate of quantitative rainfall estimation algorithm.

Variations of Soil Bulk Density and Natural Revegetation on the Logging Road of Timber Harvested-Sites (벌채적지(伐採跡地) 운재로(運材路)의 토양가밀도(土壤假密度) 변화(變化)와 자연식생회복(自然植生回復)에 관한 연구(硏究))

  • Woo, Bo-Myeong;Park, Jae-Hyeon;Kim, Kyung-Hoon
    • Journal of Korean Society of Forest Science
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    • v.83 no.4
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    • pp.545-555
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    • 1994
  • The objective of the study was to provide the useful scientific data on the early rehabilitation of the legging road after timber harvesting in the forest area. This study was carried out at logging roads which were constructed during 1989 and 1994 in Mt. Baekwoon. The field survey was conducted in July, 1991. Judging from the analysis of soil bulk density, time required for recovery as the undisturbed forest soil condition was more than 10 years in the road which was left, and the regression equation is as follows, $$Y_1=1.4195-0.0744{\cdot}X(R^2=0.91)$$ $$Y_2=1.4673-0.0688{\cdot}X(R^2=0.73)$$ (X : elapsed year after road construction. $Y_1$, $Y_2$ : soil bulk density($g/cm^3$) at 0~7.5cm, and 7.5~15.0cm, respectively) Especially soil bulk density with buffer strip-woods was $0.890-0.903g/cm^3$, so it was 20% lower than that of logging road surface without buffer strip-woods. Among the 7 factors, location, sand content, and soil hardness had statistically significant effect on the soil bulk density in logging road surface. The pioneer species on logging road surface were Rhus cratargifolius, Prunus chinensis, and Lespedeza cyrtobotrya, etc. in woody species, and Pteridium aquilinum, Arundinella hirta, and Lysimachia clethroides, etc. in herb species. So, in process of year, average plant coverage were 70% on cutting and banking slope and 20% on logging road surface which elapsed 6 years after logging road construction. Through this research, buffer strip-woods must be remained for environmental conservation of forest conditions, and from the time to be closed the road, planting, seeding, and grazing works could be effective to the soil condition and vegetation recovery.

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Biomass and Net Production of a Natural Quercus variabilis Forest and a Populus alba × P. glandulosa Plantation at Mt. Mohu Area in Chonnam (전남(全南) 모후산지역(母后山地域) 굴참나무천연림(天然林)과 현사시나무인공림(人工林)의 물질생산(物質生産)에 관(關)한 연구(硏究))

  • Choi, Young Cheol;Park, In Hyeop
    • Journal of Korean Society of Forest Science
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    • v.82 no.2
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    • pp.188-194
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    • 1993
  • A natural Quercus variabilis forest and a Populus alba${\times}$P. glandulosa plantation in Mt. Mohu area were studied to investigate aboveground biomass and net production. A $20m{\times}30m$ quadrat was set up in each stand, and 10 sample trees each of Quercus variabilis and Populus alba ${\times}$ P. glandulosa were cut for dimension analysis. There was little difference in accuracy among three biomass regression models of logWt=A+BlogD, $logWt=A+BlogD^2H$, and logWt=A+BlogD+ClogH, where Wt. D, and H were dry weight, DBH, and height, respectively. Aboveground total biomass of Quercus variabilis stand was 31,275kg/ha, and that of Populus alba ${\times}$ P. glandulosa was 55,581kg/ha. In both of Quercus variabilis stand and Populus alba ${\times}$ P. glandulosa stand, the proportion of each tree component to abovegound total biomass was high in order of stem wood, branches, stem bark, and leaves. Quercus variabilis stand was higher in the proportion of stem bark, branches and leaves than Populus alba ${\times}$ P. glandulosa stand, while the former was lower in that of stem wood than the latter. Aboveground total net production of Quercus variabilis stand was 4,267kg/ha/yr., and that of Populus alba ${\times}$ P. glandulosa stand was 3,903kg/ha/yr. The proportion of each tree component to aboveground total net production of Quercus variabilis stand was high in order of leaves, stem wood, branches, and stem bark. That of Populus alba ${\times}$ P. glandulosa stand was high in order of stem wood, leaves, branches, and stem bark. Net assimilation rate and efficiency of leaf to produce stem of Quercus variabilis stand were 2.121 and 0.840, respectively. Those of Populus alba ${\times}$ P. glandulosa stand were 3.376 and 2.085, respectively. Though Populus alba${\times}$P. glandulosa stand was lower in aboveground total net production than Quercus variabilis stand, the former was higher in aboveground total biomass than the latter. The reason was that Populus alba${\times}$P. glandulosa stand was higher in net production of stem wood of accumulation organs than Quercus variablis stand.

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Neural Bases of Empathy in Competitive vs. non-Competitive situation (경쟁과 비경쟁 상황에서 공감의 신경학적 기제)

  • Hwang, Su-Young;Yoon, Mi-Sun
    • Korean Journal of Cognitive Science
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    • v.27 no.3
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    • pp.441-467
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    • 2016
  • This fMRI study is aim to investigate effects of competitive environment in cognitive empathic process in human brain. Empathy is known as a crucial factor for human's adaptive behavior in aspects of social cognition and it is almost automatic process, on the other hand competitive situation is psychologically devastated environment to win someone for getting rewards. We hypnotized that reading and understanding of other person's mind are a specific characteristic related to survival evolutionarily, however competition would have an effect on the empathic cognitive process because of mechanisms of competition. To manipulate the competitive atmosphere, one researcher took a role of competitor against participants and they were instructed to get monetary rewards when their performance was better than a competitor. 21 participants(9 males and 12 females) performed to judge the emotional valence of the empathic task consisted of illustrated images with various situation could be experienced in real world as on $1^{st}$ person perspective in both competitive and non-competitive condition, and did same performance with objects stimulus in control condition. In order to examine the competition effects on empathic process,, hemodynamic response were obtained during fMRI session and the imaging data were analyzed to identify brain regions where responses to each condition across the two consecutive runs. Participants' reaction time in competitive condition was faster statistically significant than non-competitive one. Activation for competitive condition increased in the following areas: ACC, mPFC, SMG, thalamus extended caudate and Nacc, parahippocampal gyrus, and for non-competitive condition increased paracingulate gyrus, temporal pole, vmPFC, superior occipital gyrus. As a result of regression analysis using empathic scores as covariance, the rSMG, IFG, fusiform gyrus, thalamus, putamen were correlated with higher empathic levels, and TPJ were correlated with lower empathic scores. We suggest that these observations could mean competitive environment have an effect on neural base of cognitive empathic process.

Serum Albumin Concentrations and Clinical Disorders by Gestational Ages in Preterm Babies (미숙아에서 재태 연령에 따른 혈청 알부민치와 임상증상과의 관계)

  • Lee, Mia;Yun, Soo;Lim, Baek Keun;Kim, Jong Soo
    • Clinical and Experimental Pediatrics
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    • v.48 no.2
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    • pp.148-153
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    • 2005
  • Purpose : The aim of this study was to determine the reference ranges of serum albumin levels depending on the gestational ages of preterm infants. We also intended to compare the mean serum albumin levels between groups of preterm infants that did not develop clinical disorders later, and groups that did develop clinical disorders such as respiratory distress syndrome, intraventricular hemorrhage, retinopathy of prematurity, apnea and bronchopulmonary dysplasia. We also examined the significance of serum albumin as a predictor for the development of clinical disorders. Methods : The records of 208 neonates with gestational ages from 23 weeks to 41 weeks were reviewed retrospectively. The mean albumin concentrations with reference ranges by gestational ages were determined. Statistics for each two of group were compared. Logistic regression analysis was used to model odd ratio, and 95 percent confidence interval as a mean of the association between predictors and outcome. Results : Serum albumin levels were at 23-24 weeks gestation was 2.36 g/dL, rising to 3.43 g/dL in full term babies. There were significant mean differences between the clinical groups and control groups for each clinical disorder such as respiratory distress syndrome, intraventricular hemorrhage, retinopathy of prematurity and apnea in premature babies of 30-36 weeks of gestation. Low serum albumin appeared to be associated with increased risks of clinical disorders. Conclusion : The normal serum albumin levels in preterm infants should be defined according to the gestational ages. Lower albumin levels increase the risks of the later development of clinical disorders, which are common in premature infants.

Perinatal Factors Affecting Thyroid Stimulating Hormone(TSH) and Thyroid Hormone Levels in Cord Blood (제대혈 갑상선 자극호르몬과 갑상선 호르몬 농도에 영향을 주는 주산기 인자들)

  • Kim, Eun Young;Park, Sang Kee;Song, Chang Hun;LIm, Sung-Chul
    • Clinical and Experimental Pediatrics
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    • v.48 no.2
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    • pp.143-147
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    • 2005
  • Purpose : The aim of the this study was to evaluate the effect of various perinatal conditions on TSH and thyroid hormone levels in cord blood. Methods : Cord blood samples were collected from 130 neonates immediately after birth. TSH, $T_3$, and free $T_4$ levels were measured by the radioimmunoassay(RIA) method. The effects of gestational age, sex, birth weight, delivery method, perinatal asphyxia, maternal diabetes mellitus(DM), and preeclampsia on TSH and thyroid hormone levels were assessed by ANOVA test, Student t-test, and multiple regression analysis. Results : Birth weight and sex did not affect TSH and thyroid hormone levels. TSH level increased according to gestational age(P<0.05). TSH level was $4.42{\pm}0.66{\mu}IU/mL$ in infants born vaginally, which was higher than that of cesarian section delivery($3.31{\pm}0.33{\mu}IU/mL$)(P<0.05). TSH level was $5.18{\pm}0.93{\mu}IU/mL$ in asphyxiated newborns and $2.97{\pm}0.84{\mu}IU/mL$ in non-asphyxiated newborns(P<0.05). TSH level in infants with maternal DM($8.911{\pm}1.25{\mu}IU/mL$) was higher than that of infants without maternal DM($4.32{\pm}0.42{\mu}IU/mL$)(P<0.05). TSH level was $5.28{\pm}0.42{\mu}IU/mL$ in infants with maternal preeclampsia and $3.65{\pm}0.46{\mu}IU/mL$ in infants without maternal preeclampsia(P<0.05). Thyroid hormones were lower in infants with perinatal asphyxia(P<0.05). In asphyxiated infants, $T_3$ level was $75.33{\pm}55.65ng/mL$ and free $T_4$ was $0.54{\pm}0.21ng/mL$. $T_3$ and free $T_4$ level was $109.85{\pm}41.77ng/mL$ and $0.76{\pm}0.22ng/mL$ each in infants without perinatal asphyxia. Among the perinatal factors, gestational age, 1 min Apgar score and maternal DM influenced TSH level independently. Conclusion : In our study, cord blood TSH and thyroid hormone levels were affected by perinatal stress events.

Optimization for the Physical Properties of Steamed Foam Cakes Prepared with Single-stage Method by Response Surface Methodology (반응표면 분석법에 의한 단단계법 거품형 찜 케이크의 물리적 특성의 최적화)

  • Kwhak, Sung-Ho;Jang, Myung-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.557-566
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    • 2005
  • In preparation of steamed foam-cakes, effects of whipping time, amount of wheat flour, and amounts of emulsifier on physical properties of the steamed foam cakes were investigated using RSM (response surface methodology). The three independent variables selected for the RSM experiment were whipping time $(X_1)$, amount of wheat flour $(X_2)$, and amounts of wheat flour $(X_2)$, and concentration of emulsifier $(X_3)$ were set for single-stage mixing, respectively. A rotatable central composite design was used for treatment arrangement. The responses from the product for loaf volume, color values and textural properties were analysed. In the analysis of variance for the foam cakes prepared by single-stage method, significant interactions were observed between independent variables (experimental factors) and physical property like loaf volume (p<0.05); textural properties like hardness, gumminess, and chewiness (p<0.05). Among independent variables, concentration of emulsifier had the most effects on physical properties while whipping time. The ordinary points in surface response showed maximal points with physical property like colorimetric b value while other properties revealed saddle points. The 3-dimensional response surface graphs of the predicted regression models displayed decreasing loaf volumes with increasing whipping times and emulsifier concentrations beyond optimum levels. The optimum conditions for best loaf volume and textural property (hardness, gummimess and chewiness) of the products selected by extracting intersectional areas of the contour maps that commonly overlapped all characteristics were; $11\~13$ min whipping time, $470\~486\;g$ amount of wheat flour, and $19\~20\;g$ emulsifier concentration, in case of single-stage method. The median values extracted from the RSM experimental results for optimum manufacturing conditions for single-stage method, i.e., 12 min whipping time, 478 g amount of wheat flour, and 20 g emulsifier concentration were empirically proven to fit the predicted levels of physical properties from the final foam cakes.

Association between intake of antioxidant vitamins and metabolic syndrome risk among Korean adults (한국 성인의 항산화 비타민 섭취와 대사증후군 위험 간의 관련성)

  • Ahn, Seoeun;Jun, Shinyoung;Kang, Minji;Shin, Sangah;Wie, Gyung-Ah;Baik, Hyun Wook;Joung, Hyojee
    • Journal of Nutrition and Health
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    • v.50 no.4
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    • pp.313-324
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    • 2017
  • Purpose: The purpose of this study was to examine the association between intake of antioxidant vitamins and prevalence of metabolic syndrome (MetS) among Korean adults. Methods: A total of 614 subjects aged 30~60 years were recruited from those who received a medical checkup at a general hospital in South Korea between 2009 and 2012. Presence of MetS was determined based on criteria issued by the NCEP ATP III. Intakes of antioxidant vitamins (vitamin A, retinol, carotenoids, vitamin C, and vitamin E) were estimated by combining 3-day diet records with an antioxidant vitamin database for common Korean foods. We used multiple logistic regression analysis to assess the association between dietary intakes of antioxidant vitamins and MetS. Results: Men in the highest tertile for retinol (OR = 0.40, 95% CI = 0.23~0.71, P for trend = 0.0009), carotenoids (OR = 0.57, 95% CI = 0.32~1.00, P for trend = 0.0470), and vitamin E (OR = 0.52, 95% CI = 0.30~0.92, P for trend = 0.0190) intakes had a lower likelihood of having Mets than those in the lowest tertile. The OR of high fasting blood glucose among men in the highest tertile for vitamin A (${\mu}g$ RE: OR = 0.55, 95% CI = 0.32~0.97, P for trend = 0.0417, ${\mu}g$ RAE: OR = 0.52, 95% CI = 0.29~0.92, P for trend = 0.0211), carotenoids (OR = 0.41, 95% CI = 0.23~0.73, P for trend = 0.0036), and vitamin E (OR = 0.47, 95% CI = 0.26~0.82, P for trend = 0.0080) intakes was lower than those in the lowest tertile. In women, subjects in the highest tertile of retinol intakes had a lower prevalence of MetS than those in the lowest tertile group (OR = 0.55, 95% CI = 0.30~0.98). The OR for abdominal obesity was lower among women with the highest vitamin A (${\mu}g$ RE) intakes compared to those in the lowest tertile (OR = 0.51, 95% CI = 0.28~0.93, P for trend = 0.0293). Conclusion: These results suggest that dietary intakes of antioxidant vitamins might be associated with reduced risk of having MetS among Korean adults.