• Korean Journal of Radiology
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• v.21 no.6
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• pp.707-716
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• 2020

Objective: To evaluate pharmacokinetic variables from contrast-enhancing lesions (CELs) and non-enhancing T2 high signal intensity lesions (NE-T2HSILs) on dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in glioblastoma (GBM) patients. Materials and Methods: Sixty-four GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. We analyzed the pharmacokinetic variables of the volume transfer constant (Ktrans) and volume fraction of extravascular extracellular space within the CEL and NE-T2HSIL of the entire tumor. Univariate and multivariate Cox regression analyses were performed using preoperative clinical characteristics, pharmacokinetic variables of DCE MR imaging, and postoperative molecular biomarkers to predict PFS. Results: The increased mean Ktrans of the CEL, increased 95th percentile Ktrans of the CELs, and absence of methylated O⁶-methylguanine-DNA methyltransferase promoter were relevant adverse variables for PFS in the univariate analysis (p = 0.041, p = 0.032, and p = 0.083, respectively). The Kaplan-Meier survival curves demonstrated that PFS was significantly shorter in patients with a mean Ktrans of the CEL > 0.068 and 95th percentile Ktrans of the CEL > 0.223 (log-rank p = 0.038 and p = 0.041, respectively). However, only mean Ktrans of the CEL was significantly associated with PFS (p = 0.024; hazard ratio, 553.08; 95% confidence interval, 2.27-134756.74) in the multivariate Cox proportional hazard analysis. None of the pharmacokinetic variables from NE-T2HSILs were significantly related to PFS. Conclusion: Among the pharmacokinetic variables extracted from CELs and NE-T2HSILs on preoperative DCE MR imaging, the mean Ktrans of CELs exhibits potential as a useful imaging predictor of PFS in GBM patients.

• Clinical and Experimental Pediatrics
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• v.65 no.2
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• pp.90-97
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• 2022

Background: Stunting is affected by various factors from mother and child. Previous studies assessed only one or more influencing variables. Unfortunately, nor the significant influence of maternal and child factors nor the indicators contributing to maternal and child factors that affect the stunting incidence have ever been analyzed. Purpose: This study analyzed the effect of maternal and child factors on stunting and the significant indicators that shape the maternal and child factors that impact stunting. Methods: This was a case-control study. Overall, 132 stunted children and 132 nonstunted children in Purbalingga Regency, Central Java Province, participated in the research. Direct interviews and medical record reviews were conducted to assess the studied variables. The research data were tested using the partial least squares structural equation with a formative model. Results: Maternal factors directly affected the occurrence of stunting (t=3.527, P<0.001) with an effect of 30.3%. Maternal factors also contributed a significant indirect effect on stunting through child factors (t=4.762, P<0.001) with an effect of 28.2%. Child factors affected the occurrence of stunting (t=5.749, P<0.001) with an effect of 49.8%. The child factor was influenced by maternal factor with an effect of 56.7% (t=10.014, P<0.001). The moderation analysis results demonstrated that maternal and child factors were moderate predictive variables of stunting occurrence. Conclusion: Child factors have more significant and direct effects on stunting than maternal factors but are greatly affected by them.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.19-26
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• 2003

An oscillating digger mechanism was designed, constructed. and tested. The mechanism is consisted of a six-bar linkage, one four-bar linkage was fer the digger blade and the other one fur variable soil-crop separation. Experimental variables were amplitude(3, 6, 9 mm). frequency(11.2, 14.9. 17.0 Hz), and forward speed of tractor(0.91, 1.13, 1.56 km/h). Each combination of these variables was replicated three times to measure the draft and torque for power requirement evaluation. and the broken-up soil height on the soil separation sieve mechanism. Four parameters λ(the ratio of vibration speed to forward velocity), p(the ratio of vibration acceleration to forward velocity), K(the ratio of vibration acceleration to gravitational acceleration), and T(the product of λ and K) were induced from three experimental variables: amplitude, frequency, and tractor speed. And the power requirement and soil separation ability were analyzed by regression. Though λ and K were known to be the representative parameters. T was the most moderate one to explain draft. torque. and soil separation in this study. It was estimated that the T equal to or greater than 2.4 was the minimum recommended value. Figure 18 would be useful fir the selection of amplitude. frequency, or operating tractor speed once any two variables are known.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.37-46
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• 1996

The purpose of this study is to increase the economical efficiency and the efficiency of MIS user's attitudes. It hypothesized that an attitudes of users are different from an environmental variables and demographic variables of an organization. So, it selected attitude variables as moderating variables. The sample in this study is the management staff of financial industries only, and the data are selected by field study using a questionnaire. The hypotheses adopted were analyzed statistically by t-test and ANOVA etc.

• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.135-143
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• 2014

The variability and temporal trends of the annual and seasonal minimum and maximum temperature, rainfall, relative humidity, wind speed, sunshine hours, and runoff were analyzed for 5 major rivers in Korea from 1960 to 2010. A simple regression and non-parametric methods (Mann-Kendall test and Sen's estimator) were used in this study. The analysis results show that the minimum temperature ($T_{min}$) had a higher increasing trend than the maximum temperature ($T_{max}$), and the average temperature increased by about $0.03^{\circ}C\;yr.^{-1}$. The relative humidity and wind speed decreased by $0.02%\;yr^{-1}$ and $0.01m\;s^{-1}yr^{-1}$, respectively. With the exception of the Han River basin, the regression analysis and Mann-Kendall and Sen results failed to detect trends for the runoff and rainfall over the study period. Rapid land use changes were linked to the increase in the runoff in the Han River basin. The sensitivity of the evapotranspiration and ultimately the runoff to the meteorological variables was in the order of relative humidity > sunshine duration > wind speed > $T_{max}$ > $T_{min}$. Future studies should investigate the interaction of the variables analyzed herein, and their relative contributions to the runoff trends.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.189-191
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• 2015

The calibration of the period luminosity relation (PLR) for Galactic Mira variables is one of the principle aims of the VERA project. We observe $H_2O$ maser emission at 22 GHz associated with Mira variables in order to determine their distances based on annual parallaxes. We conduct multi-epoch VLBI observations over 1-2 years with a typical interval of one month using VERA in order to obtain annual parallaxes with an accuracy of better than than 10%. Recently, the annnual parallax of T Lep was determined to be $3.06{\pm}0.04$ mas corresponding to a distance of $327{\pm}4pc$ (Nakagawa et al., 2014). The circumstellar distribution and kinematics of $H_2O$ masers was also revealed. With accurate distances to the sources, calibrations of K-band absolute magnitudes ($M_K$) can be improved compared to conventional studies. By compiling Mira variables whose distances were determined with astrometric VLBI, we obtained a PLR of $M_K=3.51logP+1.37{\pm}0.07$.

• Child Health Nursing Research
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• v.7 no.3
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• pp.280-297
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• 2001

The purpose of the study was to develop and test the model for the quality of life in mothers of children with nephrotic syndrome. A hypothetical model was constructed on the basis of previous studies and a review of literature. The conceptual framework was built around ten constructs. Exogenous variables included in this model were mother's health, father's health, marital intimacy, mother's attitude on children, economic state, side effect of steroid, severity of illness and social support. Endogenous variables were mother's burden and quality of life. Empirical data for testing the hypothetical model were collected by using a self-report questionnaire from 152 mothers of children with nephrotic syndrom at the outpatient clinics and in the hospital. The data was collected from May, 1999 to August, 1999.Reliability of the seven instruments was tested with Cronbach's alpha which ranged from 0.71 - 0.92.For the data analysis, SPSS 8.0 WIN program and LISREL 8.20 WIN program were used for descriptive statistics and covariance structural analysis. The results of covariance structural analysis were as follow :1. The hypothetical model showed a good fit with the empirical data. [x2 = .56, df = 3, p = .90(p>.05 ), GFI = .99, AGFI = .99, RMSR = .005.] 2. For the parsimony of model, a modified model was constructed by deleting 1 variable and excluding 2 paths according to the criteria of statistical significance and meaning.3. The modified model also showed a good fit with the data[x2 = 2.83, df = 7, p = .90( p>.05 ), GFI = 1.00, AGFI = .97, RMSR = .011].The result of the testing of the hypothesis were as follows : 1. Mother's health(γ21 = .26, t = 4.16), father's health(γ22 = .19, t = 2.92), marital intimacy(γ23 = .26, t = 4.13) and social support(γ28 = .12, t = 2.03) had a significant direct effect on the quality of life.2. Mother's burden(β21 = -.20, t = -3.10) had a significant negative direct effect on the quality of life.3. Mother's attitude on children(γ14 = -.34, t = .-4.57), mother's health(γ11 = -.22, t = -2.96) and side effect of steroid (γ16 = -.23, t = .-2.69) had a significant direct negative effect on the burden. The result of this study showed that mother's health, marital intimacy, mother's burden, father's health, and social support had a significant direct effect on the quality of life. Mother's attitude on children, mother's health, and side effect of steroid had a significant direct effect on mother's burden. These six variables, mother's health, marital intimacy, father's health, social support, mother's attitude on children and side effect of steroid were identified as relatively important variables. The results of this study suggest, it needed to determine the nursing intervention will alleviate mother's burden and promote a greater quality of life in mothers of children with nephrotic syndrom.

• Journal of the Korean Data and Information Science Society
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• v.9 no.2
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• pp.105-111
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• 1998

In this paper a fuzzy regression model based on the weakest t-norm is introduced. The model shows a regression model which has fuzzy coefficients and fuzzy variables.

• Journal of Welding and Joining
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• v.23 no.6
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• pp.61-66
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• 2005

A probabilistic approach for evaluating failure risk is suggested in this paper. Probabilistic fracture analyses were performed for a pressurized pipe of a Cr-Mo steel reflecting variation of material properties at high temperature. A crack was assumed to be located along the weld fusion line. Probability density functions of major variables were determined by statistical analyses of material creep and creep crack growth data measured by the previous experimental studies by authors. Distributions of these variables were implemented in Monte Carlo simulation of this study. As a fracture parameter for characterizing growth of a fusion line crack between two materials with different creep properties, $C_t$ normalized with $C^*$ was employed. And the elapsed time was also normalized with tT, Resultingly, failure probability as a function of operating time was evaluated fur various cases. Conventional deterministic life assessment result was turned out to be conservative compared with that of probabilistic result. Sensitivity analysis for each input variable was conducted to understand the most influencing variable to the analysis results. Internal pressure, creep crack growth coefficient and creep coefficient were more sensitive to failure probability than other variables.

• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.413-424
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• 2000

The purpose of this study was to analyze the effect of anticipated variables on hemodialysis that was impact patients' quality of life. The subjects of the study were 104 patients who were over 18 years old. They were enrolled at Kidney dialysis unit in General Hospital located in T and M city, Republic Korea. And the duration of treatment was more than 6 months. They all met the research criteria and agreed to participate in the research. The research instrument have 25 questionnaire which were originally Ferrans' (1985) instrument to measure the quality of life for hemodialysis patients and later changed by Lee, Suk-Ja into the 35 items after eliminating repeated contents, the Cronbach's $\alpha$in this study was .87. The stress instrument was measured by 36 items which were modified and supplemented the instrument developed by Kim, Yong-Kyong(15) for hemodialysis patients, and the Cronbach's $\alpha$was .9333. Depression instrument was 20 questions modified BDI(Beck Depression Inventory) to meet hemodialysis patients' conditions, and Cronbach's $\alpha$ was .92. June 25, 1999 and the data was analyzed by SPSS/PC, and the statistical techniques were ANOVA(variables analysis), Scheffe test, Multiple Regression. The findings of this study were as follows: 1. The effect of general characteristics on hemodialysis patients' quality of life, the characteristics showing a statistically, significant difference were the existence of an occupation(t=6.7353, P= .0109), marital status (F=4.3550, P= .0290), economic status (F=4.6475, P= .0118) and presence of care support (F=2..4738, P= .0494). 2. The effect of general characteristics on the patient's stress, the characteristics showing a significant difference were gender (t= 4.1143, p= .0451), education level (F= 4.3550, p= .008), the existence of an occupation (t=8.7498, p= .0038), and presence of care support(F=3.1715, p= .0169). 3. The effects of general characteristics on depression, the characteristics were education level (F=3.7517, P= .0069), the existence of religion(t=9.4843, p= .0027), an occupation (t=15.3745, p= .0002), marital status (F=3.3400, P= .0223) and presence of care support (F=3.7605, p= .0069). 4. The Multiple Regression is used to identify the effect of anticipated variables on the patient's quality of life. The variables were depression (T=-9.656, P=.000), marital status (T=-2.287, P=.0243) and the regression expression was Y=117.62053 - 1.13618Χ$_1$ + 2.66213Χ$_2$(Χ$_1$: Depression, Χ$_2$ : Marriage), The explanation of the total regression expression appeared to be 52.578%.