• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.11-22
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• 2023

We report the result of a high-resolution spectroscopic study on seven magnesium (Mg) enhanced stars. The high Mg abundances in these stars imply that they were born in an environment heavily affected by the nucleosynthesis products of massive stars. We measure abundances of 16 elements including Mg and they show various abundance patterns implying their diverse origin. Three of our program stars show a very high Mg to Si ratio ([Mg/Si] ≈ 0.18-0.25), which might be well explained by fall-back supernovae or by supernovae with rapid rotating progenitors having an initial mass higher than about 20 M_⊙. Another three of our program stars have high light to heavy s-process element ratios ([Y/Ba] ≈ 0.30-0.44), which are consistent with the theoretical prediction of the nucleosynthesis in rapidly rotating massive stars with an initial mass of about M = 40 M_⊙. We also report a star having both high Y ([Y/Fe] = 0.2) and Ba ([Ba/Fe] = 0.28) abundance ratios, and it also shows the highest Zn abundance ratio ([Zn/Fe] = 0.27) among our sample, implying the nucleosynthesis by asymmetric supernova explosion induced by very rapid rotation of a massive progenitor having an initial mass between 20 M_⊙ ≲ M ≲ 40 M_⊙. A relative deficiency of odd-number elements, which would be a signature of the pair-instability nucleosynthesis, is not found in our sample.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1127-1135
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• 2009

Purpose : To observe the abnormal white matter findings on the magnetic resonance imaging (MRI) scans of very-low- birth-weight (VLBW) infant brains at term-equivalent age and to determine the clinical risk factors for the development of periventricular leukomalacia (PVL). Methods : In all, MRI was performed in 98 VLBW infants and the white matter abnormalities were observed. Clinical risk factors for cystic and noncystic PVL were determined. Results : MRI scans of 74 infants (75.5%) showed diffuse excessive high signal intensity (DEHSI) in the periventricular white matter, 17 (17.3%) lateral ventricle dilation, 5 (5.1%) and 11 (11.2%) focal punctate lesions and cystic changes in the periventricular white matter, respectively, 9 (9.1%), germinal layer hemorrhage (GLH) or subependymal cysts 3 (3.1%) intraventricular hemorrhage (>grade 2) 2 (2.0%) posthemorrhagic hydrocephalus and 2 (2.0%) periventricular hemorrhagic infarct. Gestational age (GA), 1-minute Apgar score, Clinical Risk Index for Babies-II (CRIB-II) score, and inotrope use, and GA, CRIB-II score, postnatal steroid administration, inotrope use, and abnormal white blood cell (WBC) count at admission were related to cystic PVL and noncystic PVL development, respectively (P<0.05). However, in logistic regression analysis, CRIB-II (odds ratio, 1.63, 295% confidence interval, 1.15-2.30 P=0.006) for cystic PVL, and GA (odds ratio 0.90, 95% confidence interval, 0.82-0.99 P=0.036) for noncystic PVL were only significant independently. Conclusion : White matter abnormalities could be observed on MRI scans of the VLBW infant brains at term-equivalent age, and CRIB-II and GA were only independently significant for cystic and noncystic PVL development, respectively.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.749-755
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• 2004

Fluosilicic acid ($H_2SiF_6$) is recovered as aqueous solution which absorbs $SiF_4$ produced from the manufacturing of industrial-graded $H_3PO_4$ or HF. Generally, fluosilicate salts prepared by the reaction between $H_2SiF_6$ and metal salts. Addition of fluosilicate salts to cement endows odd properties through unique chemical reaction with the fresh and hardened cement. In this study, two-component fluosilicate salt based chemical admixtures (MZ) of $4\%,\;6\%$, and $8\%$ concentration were prepared by the reaction of $H_2SiF_6$ ($25\pm2\%$) and metal salts. The effect of concentration of MZ at a constant adding ratio on the hydration and watertightness of cement were investigated respectively. In a cement containing MZ, metal fluorides such as $CaF_2$ and soluble silica by hydrolysis were newly formed during hydration. The total porosity of the hardened cement was lower in the presence of U because of packing role of metal fluoride and pozzolanic reaction of soluble $SiO_2$. Consequently, the watertightness of the hardened paste containing MZ was more improved than non-added (plain) due to an odd hydration between cement and MZ.

• Journal of Internet of Things and Convergence
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• v.4 no.2
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• pp.21-28
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• 2018

I investigated that ALK receptor tyrosine kinase (ALK) gene polymorphisms were contributed to susceptibility to ICH in Korean population. I recruited 156 ICH patients and 425 healthy controls for this study, respectively. rs1881421, rs1881420, rs3795850, and rs2246745 single nucleotide polymorphisms (SNPs) were genotyped. The genotype and allele distributions of tested four SNPs was analyzed using the SNPStats, SPSS 22.0, and the Haploview v.4.2 software. The Odd's ratios (OR), 95% confidence intervals (CI), and P values were calculated in allele and genotype models. I found that rs1881421, rs1881420, rs3795850, and rs2246745 SNPs of ALK gene (rs1881421, OR=2.02, 95% CI=1.54-2.64, p<0.001; rs1881420, OR=0.53, 95% CI=1.16-2.01, p=0.003; rs3795850, OR=1.54, 95% CI=1.17-2.02, p=0.002; rs2246745, OR=1.95, 95% CI=1.46-2.60, p<0.001 in each allele analysis). And distributions of CC, GT, and GC haplotypes between the ICH group and the control group also showed significant association with ICH (CC haplotype, p<0.001; GT haplotype, p=0.006; GC haplotype, p<0.001). These minor alleles of tested four SNPs in ALK gene were contributed to increased risk of development for ICH. Our findings suggested that the ALK gene may be a risk factor for susceptibility to ICH.The Korea Internet of Things Society.

• Geophysics and Geophysical Exploration
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• v.2 no.4
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• pp.180-183
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• 1999

A proto-type seismic measurement system with a reference was developed to improve S/N (signal-to-noise ratio) of seismic data, especially in noisy urban areas. Two pairs of correlation measurements (the one for microphone and geophone, and another for electromagnetic (EM) loop and geophone) were carried out near Kimpo Airport and at Kimje. The spectrum analyses were also performed to investigate the correlation of two pairs of time series; one for microphone and geophone, and another for EM loop and geophone. The sound waves measured with the microphone and the geophone are highly correlated. However, differences in the reponses are readily identifiable across 200 Hz; in the vicinity of 100 Hz, the spectral energy for geophone is 20 dB higher than that for microphone, and at near 500 Hz, the spectral energy for microphone is 30 dB higher than that for geophone. Overall, the spectral energy appears concentrated on the frequency window below 600 Hz for geophone. It contrasts with the observation of dominant frequency at the range of above 200 Hz for microphone. The wave forms of EM noise (due to an ACDC inverter) measured with EM loop and geophone are consistently and highly correlated each other. The power spectrum of the EM noise for EM loop shows that the spectral energies at odd harmonic frequencies of 60 Hz are higher than those at even harmonic frequencies of 60 Hz. It is compared to the power spectrum for geophone; the spectral energies at odd harmonics are nearly same as those at even harmonic frequencies.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.57-64
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• 2006

The crack presented in concrete structures causes a structural defect, the durability decrease, and external damages etc. Therefore, it is necessary to improve durability through the effort to control the crack. Fluosilicic acid($H_2SiF_6$) is recovered as aqueous solution which absorbs $SiF_4$ produced from the manufacturing of industrial-graded $H_3PO_4$ or HF. Generally, fluosilicates prepared by the reaction between $H_2SiF_6$ and metal salts. Addition of fluosilicates to cement endows odd properties through unique chemical reaction with the fresh and hardened cement. Mix proportions for experiment were modulated at 0.45 of water to cement ratio and $0.0{\sim}2.0%$ of adding ratio of fluosilicate salt based inorganic compound. To evaluate correlation of concrete strength and adding ratio of fluosilicate salt based inorganic compound, the tests were performed about design strength(21, 24, 27 MPa) with 0.5% of adding ratio of fluosilicate salt based inorganic compound. Applications of fluosilicate salt based inorganic compound to reduce cracks resulted from plastic and drying shrinkage, to improve durability are presented in this paper. Durability was evaluated as neutralization, chloride ion penetration depth, freezing thawing resistant tests and weight loss according reinforcement corrosion. It is ascertained that the concrete added fluosilicate salt based inorganic compound showed m ability to reduce the total area and maximum crack width significantly as compared non-added concrete. In addition, the durability of concrete improved because of resistance to crack and watertightness by packing role of fluosilicate salt based inorganic compound obtained and pozzolanic reaction of soluble $SiO_2$ than non-added concrete.

• Journal of agricultural medicine and community health
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• v.22 no.1
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• pp.49-59
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• 1997

Backgrounds : There has been many studies investigating the causes of farmers' syndrome. In some studies, psychologic stress is related to farmer's syndrome. And the diagnostic criteria of farmer's syndrome is similar to those of generalized anxiety disorder. So we carried out this study to investigate the psychiatric causes of farmers' syndrome. Methods : This study was done in some rural and urban areas of Kyoungsangnam Province, July, August, October and November of 1996. Those who came to free medical service and completed interview, medical examination and laboratory examination and 20-59 years old were 150 persons. And those who came to health center for health examination and completed only interview and 20-59 years old were 94 persons. The questionnaire was composed of sociodemographic factors, health risk factors, farmer's syndrome, work load, BEPSI(inventory to measure stress), Spielberger's state-trait anxiety inventory, self-rating depression scale. To examine statistical significance, we used X2-test, Mantel-Haenszel test for linear association, t-test, ANCOVA, correlation, multiple regression, logistic regression. Results : The prevalence of farmer's syndrome, adjusted for age and sex with population of Kyungsangnam Province of 1993 was 208 per 1,000(90 per 1,000 in men and 329 per 1,000 in women). In bivariate analysis, farmer's syndrome was significantly related to age, sex, job, income, smoking, alcohol drinking, work load, BEPSI, state anxiety, trait anxiety, depression, body mass index, Hwa-Byung, hypertension, anemia. However, when age and sex were adjusted, job was not significantly related to farmer's syndrome. The score of farmer's syndrome was significantly related to age, sex, work load, BEPSI, trait anxiety by multiple regression. Farmer's syndrome was significantly related to increasing age(odd ratio 1.079, 95% C.I. 1.060 - 1.099), sex(odds ratio of male 0.434, 95% C.I. 0.349 - 0.540), and BEPSI(odds ratio 1.231, 95% C.I. 1.148 - 1.320) by logistic regression. Results of logistic regression analysis of the component symptoms of farmer's syndrome were as follows. Shoulder stiffness was significantly related to increasing age, female sex and BEPSI. Lumbago was significantly related to increasing age, female sex and trait anxiety. Numb limbs and nocturia was significantly related to increasing age and female sex. Breathlessness was significantly related to work load, sleeplessness was significantly related to depression, dizziness was significantly related to job and state anxiety, and abdominal fullness was significantly related to female sex. Conclusion : Farmers' syndrome was related to work load, but was more related to psychiatric factors such as BEPSI and trait anxiety. And the occupation was not risk factor of farmers' syndrome in this study, so further study is needed to investigate the cause of farmers' syndrome.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.633-640
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• 2020

The purpose of this study was to research the prevalence and related factors for the life care of knee osteoarthritis in Koreans agricultural and fishery population. Among the agricultural and fishery population over the age of 50, 816 people were chosen to analyze the prevalence of knee osteoarthritis and the prevalence odds ratio of social demographic or health related factors based on the primitive data of the 5th National Health and Nutrition Examination Survey (2010-2012). The prevalence of knee osteoarthritis was 26.3% and, in demographic terms, female, elders, and individuals with low level of educational attainment and monthly income showed higher prevalence of knee osteoarthritis. In health related factors, nonsmokers and people with higher BMI showed higher prevalence of knee osteoarthritis. The present cross-sectional study showing the prevalence ratio and the prevalence odd ratio revealed a high incidence of knee osteoarthritis in Korean agricultural and fishery populations.

• Journal of Korean Academy of Nursing
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• v.45 no.4
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• pp.469-482
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• 2015

Purpose: The purpose of this study was to identify which nursing interventions are the most effective in fall prevention for hospitalized patients. Methods: From 3,675 papers searched, 34 were selected for inclusion in the meta-analysis. Number of fallers, falls, falls per 1,000 hospital-days, and injurious falls, fall protection activity, knowledge related to falls, and self-efficacy about falls were evaluated as outcome variables. Data were analyzed using the Comprehensive Meta Analysis (CMA) 2.2 Version program and the effect sizes were shown as the Odd Ratio (OR) and Hedges's g. Results: Overall effect size of nursing interventions for fall prevention was OR=0.64 (95% CI: 0.57~0.73, p <.05) and Hedges's g= - 0.24. The effect sizes (OR) of each intervention ranged from 0.34 to 0.93, and the most effective nursing intervention was the education & environment intervention (OR=0.34, 95% CI: 0.28~0.42, p<.001), followed by education intervention (OR=0.57, 95% CI: 0.50~0.67, p=.001). Subgroup analyses showed that multifaceted interventions (OR=0.76, 95% CI: 0.73~0.79, p<.001) were more effective than unifactorial interventions, and that activities for prevention of falls (OR=0.08, 95% CI: 0.05~0.15, p<.001) showed the largest effect size among outcome variables. Conclusion: Falls in hospitalized patients can be effectively prevented using the nursing interventions identified in this study. These findings provide scientific evidence for developing and using effective nursing interventions to improve the safety of hospitalized patients.

• Korean Journal of Clinical Pharmacy
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• v.27 no.1
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• pp.30-37
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• 2017

Background: We investigated the impact of financial compensation on patients' decision of participation in clinical trials and the related factors with patients' attitudes and considerations. Methods: A survey questionnaire was placed from October 31 to November 16, 2017 to the subjects who were enrolled in the trials of chronic diseases. Patients' socio-demographic characteristics were collected and the potential reasons for participating in the trials were assessed using 5-likert scores. Results: Sixty eight of 110 respondents (61.8%) indicated to participate clinical trials regardless of financial compensation. The differences were found between patients who were unwilling to participate without compensation and those who were willing to participate regardless of compensation in mean ages (43.9 years vs. 52.0 years, p<0.05), marital status (married, 47.6% vs 79.4%, p<0.01), religions (yes, 45.2% vs 67.6%, p<0.05) and monthly income (${\geq}3$ million won, 19.0% vs 45.6%, p<0.01). The potential reasons for participation in the trials between two groups were doctor's suggestion (52.4% vs. 77.9%, p<0.01), the expectation of health improvement (54.8% vs. 73.5%, p<0.05), the types and numbers of procedure (33.3% vs. 16.2%, p<0.05) and the duration of clinical trials (59.5% vs. 27.9%, p=0.001). In regression analysis, the monthly income of ${\geq}3$ million won (odd ratio, OR=3.221, p=0.026,) and the duration of trials (OR=0.290, p=0.017) were related to the group with the willingness to participate regardless of compensation. Conclusion: This stady showed that more than half of study subjects would participate in the clinical trials of chronic diseases regardless of financial compensation.