• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.6
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• pp.773-783
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• 2019

A numerical analysis of a turbulent flow with a 'large-eddy breakup device(LEBU)' was performed to investigate the influence of the device on the drag of underwater vehicle using commercial CFD code, FLUENT. In the present study, the vehicle drag was decomposed to skin-friction coefficient(C_f) and pressure coefficient(C_p). The variation of the vehicle C_f and C_p were observed with changing location of the device and Reynolds number. As a result, the device decreased the vehicle C_f because it suppressed the turbulent characteristics behind the device. The larger Reynolds number, the higher reduction effect when the device was placed in front part of, and near the vehicle. On the other hand, the device increased/decreased the vehicle C_p with increasing/decreasing turbulent kinetic energy at recirculating flow region behind the vehicle. The total drag change by the device was caused by C_p rather than C_f.

• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.1046-1054
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• 2001

Effects of B$_2$O$_3$and CuO addition on the microwave dielectric properties of the PbWO$_4$-TiO$_2$ceramics were investigated in order to use this material as an LTCC material for fabrication of a multilayered RF passive components module. We found that PbWO$_4$could be used as an LTCC material because of its low sintering temperature (8$50^{\circ}C$) and fairy good microwave dielectric properties($\varepsilon$$_{r}$=21.5, Q$\times$f$_{0}$=37200 GHz and $\tau$$_{f}$ =-31 ppm/$^{\circ}C$). In order to stabilize $\tau$$_{f}$ of PbWO$_4$, TiO$_2$was added to the PbWO$_4$and the mixture was sintered at 8$50^{\circ}C$. A near zero $\tau$$_{f}$ value (+0.2 ppm/$^{\circ}C$) was obtained with 8.7 mol% TiO$_2$addition. $\varepsilon$r and Q$\times$f$_{0}$ values were 22.3 and 21400 GHz, respectively. It was believed that the decrement of Q$\times$f$_{0}$ value with TiO$_2$addition was resulted from increasing grain boundary. In order to improve Q$\times$f$_{0}$, various amounts of B$_2$O$_3$and CuO were added to the 0.913PbWO$_4$-0.087TiO$_2$mixture. The optimum amount of CuO was 0.05 wt%. At this addition, the 0.913PbWO$_4$-0.087TiO$_2$ceramic showed $\varepsilon$$_{r}$=23.5, $\tau$$_{f}$ =-2.2ppm/$^{\circ}C$, and Q$\times$f$_{0}$=32900 GHz after sintered at 8$50^{\circ}C$. In case of B$_2$O$_3$addition, the optimum amount range was 1.0~2.5 wt% at which we could obtain following results; $\varepsilon$$_{r}$=20.3~22.1, Q$\times$f$_{0}$=48700~54700 GHz, and $\tau$$_{f}$ =+2.4~+8.2ppm/$^{\circ}C$.

• Applied Biological Chemistry
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• v.43 no.3
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• pp.213-217
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• 2000

In order to investigate the removal effect of cadmium by polyphenol compound extracted from persimmon leaves(Diospyros kaki folium), animal test was done. Two fractions such as F-1 and F-2 from persimmon leaves were compared with their safety and function. The food intake of group F-1 and F-2 considerably decreased within 1% level. Cadmium addition influenced to rat growth(a tested animal), but food efficiency ratio(FER) wasn't shown any considerable difference in F-1 and F-2, as compared to the control. Cadmium content of liver, kidney and femur considerably decreased within 1% level in F-1 and F-2, compared to the control, cadmium content of liver decreased 25% in F-1, 28% in F-2 3150 decreased 22% md 25% in kidney. In femur, also decreased 53% in F-1 and 59% in F-2 respectively. The test of cadmium content in feces indicate that the content considerably increased within 1% level in both group F-1 and F-2, as compared to the control(42% in F-1, 54% in F-2). As shown the above results, have seen the removal effect of cadmium by polyphenol compound.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.159-167
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• 2006

The transform domain characterization of cyclic codes over finite fields using Discrete Fourier Transform(DFT) over an appropriate extension field is well known. In this paper, we extend this transform domain characterization for cyclic codes over $F_p + uF_p +... + u^{k-l}F_p$. We give a way to characterize cyclic codes over $F_p + uF_p +... + u^{k-l}F_p$ by Mattson-Solomon polynomials and multiple defining sets.

• Korean Journal of Materials Research
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• v.22 no.9
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• pp.489-493
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• 2012

Green phosphors $K_2BaW_2O_8:Tb^{3+}$(1.0 mol%) were synthesized by solid state reaction method. Differential thermal analysis was applied to trace the reaction processes. Three endothermic values of 95, 706, and $1055^{\circ}C$ correspond to the loss of absorbed water, the release of carbon dioxide, and the beginning of the melting point, respectively. The phase purity of the powders was examined using powder X-ray diffraction(XRD). Two strong excitation bands in the wavelength region of 200-310 nm were found to be due to the ${WO_4}^{2-}$ exciton transition and the 4f-5d transition of $Tb^{3+}$ in $K_2BaW_2O_8$. The excitation spectrum presents several lines in the range of 310-380 nm; these are assigned to the 4f-4f transitions of the $Tb^{3+}$ ion. The strong emission line at around 550 nm, due to the $^5D_4{\rightarrow}^7F_5$ transition, is observed together with weak lines of the $^5D_4{\rightarrow}^7F_J$(J = 3, 4, and 6) transitions. A broad emission band peaking at 530 nm is observed at 10 K, while it disappears at room temperature. The decay times of $Tb^{3+}$ $^5D_4{\rightarrow}^7F_5$ emission are estimated to be 4.8 and 1.4 ms, respectively, at 10 and 295 K; those of the ${WO_4}^{2-}$ exciton emissions are 22 and 0.92 ${\mu}s$ at 10 and 200 K, respectively.

• Research in Community and Public Health Nursing
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• v.13 no.4
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• pp.710-718
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• 2002

Purpose: The purpose of this study was to identify the relationship between fatigue, and self-efficacy in patients with lung cancer. Method: The data was collected from January 21th to April 8th 2001. The study subjects were recruited from K hospital in Pusan, Korea. Their fatigue was measured using the 22-item Revised Piper Fatigue Scale developed by Piper et al. (1998) and translated by the investigators, and self-efficacy was measured using the 10-item General Self-efficacy Questionnaire developed by Lee, Schwarzer & Jerusalem. The data were analyzed by SPSS 10.0 program using frequency, percentage, mean and standard deviation, t-test, ANOVA, Post-hoc test (Scheffe's test), and Pearson Correlation Coefficients. Result: 1) The mean fatigue score was $118.48{\pm}33.02$ (range: 22-220). The scores for sub-dimension were $35.40{\pm}10.06$ in behavior/severity, $25.98{\pm}9.06$ in affective score, $27.88{\pm}10.06$ in sensory score, and $29.22{\pm}8.27$ in cognitive/mood. The mean self-efficacy score was $28.80{\pm}5.85$. 2). There were significant differences in the fatigue of patients with lung cancer on income per month (F=4.651, p= .014), 'present pain' (F=2.601, p= .012), 'change of weight' (F=5.911, p= .005), by general characteristics. 3) There were significant differences in the self-efficacy of patients with lung cancer on 'religion' (F=3.732, p= .031), 'employment status' (F=5.525, p= .003), 'past therapy' (F=2.869, p= .034), by general characteristics 4) There was a significant negative correlation between fatigue and self-efficacy (r=- .528, p= .000). Conclusion: Patients with lung cancer experience fatigue. Increased fatigue is associated with decreased self-efficacy. Nurses must provide patients with nursing care for the less occurrence of fatigue and interventions to manage self-efficacy for them.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.45-49
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• 2005

Objectives: To compare the biogenetic temperament and character patterns of subjects with narcolepsy and those of healthy control subjects. Methods: Twenty-two subjects with narcolepsy, diagnosed with the International Classification of Sleep Disorder (ICSD) criteria, and 22 healthy control subjects were recruited. The Korean version of the Temperament and Character Inventory was administered to all subjects. Results: Compared to healthy control subjects, subjects with narcolepsy showed significantly higher Novelty-Seeking (ANCOVA, F=5.42, p=0.025), lower Persistence (F=8.41, p=0.006) and lower Self-Directedness scores (F=4.70, p=0.036). Conclusion: Narcoleptic patients have a distinct pattern of biogenetic temperament and character. Our findings suggest that narcoleptic patients are exploratory in response to novelty but give up easily. In addition, our findings show that narcoleptic patients consider themselves ineffective, purposeless, and fragile.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.67-73
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• 2012

Asphalt pavement waste can be recycled by crushing and heating methods with additional virgin materials and additives. In this study, a new additive using Sasol wax and Polyolefin elastomer was used for improving the quality of the Superior recycled asphalt pavement(SRP). Additive was added into the recycled mixture by 1.5% and 3% of binder content in order to have PG 70-22 and PG 76-22. Both mixtures were tested by Marshall apparatus, indirect strength testing methods, toughness testing methods, moisture susceptibility testing methods and wheel tracking testing methods. Test results met the standards of KS F 2349 and GR F 4005. Through research, it was found that these special recycled mixtures could be applied for the surface and base course of heavy traffic roads or equivalents. About 13,000 tons of the recycled mixture has been applied on Seoul Olympic road to provide new road to Hangang park for Seoul citizens.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.181-188
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• 2021

This study aims to identify the relationship among self-esteem, major satisfaction, appearance satisfaction, and employment stress of college students and to suggest suggestions for this. The subjects of this study were students in B metropolitan city, and data analysis was conducted using SPSS WIN/22.0 program. The result of the study showed that the difference in employment stress according to general characteristics was significant in grade (f=4.25, P=0.01), religion (t=0.70), department and department (F=7.50, P=.0001), personality (F=6.406, P=0.001), university life satisfaction (f=8.09, P=0.001), and average score (f=5.37, P=0.005). The employment stress of the subjects was negatively correlated with self-esteem(r=-.439, p<.001), major satisfaction(r=-.377, p<.001), and appearance satisfaction(r=-.273, p<.001).Based on the results of the study, it is necessary to develop an integrated program to improve self-esteem, major satisfaction, and appearance satisfaction in order to reduce the employment stress of college students, and repetitive studies are required to explore various factors.

• Journal of Korean Physical Therapy Science
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• v.8 no.2
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• pp.997-1003
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• 2001

The purpose of this study is to know the average of pint range of motion and difference according to the aging for the elderly, This study consisted of elder male(n=75) and elder female(n=l09), The result of assessment and analysis in shoulder pint range of motion are as follows: 1) The average shoulder flexion pint range of motion in 60-69(from sixty to sixty-nine)years old are 163.04(Left-Male), 162.91(Right-Male), 158.74 (Left-Female), 158.74 (Right-Female). 70-79years old are 149.40(L-M), 152.38(R-M), 153,37(L-F), 153.37(R-F). 80-89 years old are 149.57(L-M), 147.93(R-M), 151.17(L-F), 150.33(R-F). There was no significant difference among group, 2) The average shoulder extension pint range of motion in 60-69years old are 48.15(L-M), 47.20(R-M), 45.16(L-F), 44.23(R-F), 70-79years old are 37.l1(L-M), 38.70(R-M), 35.17(L-F), 36.71(R-F), 80-89 years old are 34.46(L-M). 36.71(R-M), 33.90(L-F), 33.09(R-F). There was significant difference among group(p<.05). 3) The average shoulder abduction pint range of motion in 60-69years old are 164.22(L-M), 165.96(R-M), 159.34(L-F), 159.97(R-F), 70-79years old are 152.27(L-M), 155.05(R-M), 152.32(L-F), 53.66(R-F), 80-89 years old are 152.17(L-M), 153.76(R-M), 147.53(L-F), 147.37(R-F). There was significant difference in right shoulder abduction among group(p<05). 4) The average shoulder internal rotation pint range of motion in 60-69years old are 63.52(L-M), 65.70(R-M), 64.16(L-F), 64.61(R-F), 70-79years old are 64.50(L-M), 65.81(R-M) 61.10(L-F), 61.83(R-F). 80-89 years old are 61.60(L-M), 61.66(R-M), 57.53(L-F), 57.53(R-F). There was no significant difference among group. 5) The average shoulder external rotation pint range of motion in 60-69years old are 50.87(L-M), 50.22(R-M), 51.03(L-F), 50.42(R-F), 70-79years old are 50.91(L-M), 50.20(R-M) 48.37(L-F), 50.20(R-F). 80-89 years old are 46.83(L-M), 47.93(R-M), 43.43(L-F), 43.72(R-F).There was significant difference in left shoulder external rotation among group(p<.05).