• Journal of The Korean Astronomical Society
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• v.51 no.6
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• pp.185-195
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• 2018

Galaxy clusters are known to host many active galaxies (AGNs) with radio jets, which could expand to form radio bubbles with relativistic electrons in the intracluster medium (ICM). It has been suggested that fossil relativistic electrons contained in remnant bubbles from extinct radio galaxies can be re-accelerated to radio-emitting energies by merger-driven shocks via diffusive shock acceleration (DSA), leading to the birth of radio relics detected in clusters. In this study we assume that such bubble consist primarily of thermal gas entrained from the surrounding medium and dynamically-insignificant amounts of relativistic electrons. We also consider several realistic models for magnetic fields in the cluster outskirts, including the ICM field that scales with the gas density as $B_{ICM}{\infty}n^{0.5}_{ICM}$. Then we perform time-dependent DSA simulations of a spherical shock that runs into a lower-density but higher-temperature bubble with the ratio $n_b/n_{ICM}{\approx}T_{ICM}/T_b{\approx}0.5$. We find that inside the bubble the shock speed increases by about 20 %, but the Mach number decreases by about 15% in the case under consideration. In this re-acceleration model, the observed properties of a radio relic such as radio flux, spectral index, and integrated spectrum would be governed mainly by the presence of seed relativistic electrons and the magnetic field profile as well as shock dynamics. Thus it is crucial to understand how fossil electrons are deposited by AGNs in the ICM and how the downstream magnetic field evolves behind the shock in detailed modeling of radio relics.

• The Korean Journal of Food & Health Convergence
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• v.8 no.6
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• pp.1-10
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• 2022

Hypercholesterolaemia is one of the risk factors of coronary health in humans; hence this research was to investigate the effect of Parkia biglobosa seeds fermented with Lactobacillus plantarum on the cardiac risk factors of diet-induced hypercholesterolaemic Wistar rats. Hypercholesterolaemia in rats were experimentally induced and the hypercholesterolaemic Wistar rats were treated with iru samples. The total cholesterol, triglyceride, high density lipoprotein (HDL), low density lipoprotein (LDL), liver biomarkers and cardiac risks factors were determined after inducement and treatment with iru. Fourteen (14)-days after inducement, the rats in the group induced had the highest weight of 112.40 g while the control group had 94.30 g. The total cholesterol (TC) in the induced group was 100.80 mg/dl while the control had 51.40 mg/dl, triglyceride (TG) in the induced group was 111.75 mg/dl while the control group had 68.45 mg/dl. After 28 days of treatment, the group treated with fermented samples showed a reduction in the TC (100.80 to 56.99 mg/dl), Triglyceride (111.75 to 32.53 mg/dl), LDL (49.48 to 6.65 mg/dl), cardiac risk ratio (3.36 to 1.28), atherogenic coefficient (3.13-0.29) and atherogenic index (0.57 to 0.11). The result from this study reveals that fermented Parkia biglobosa sample reduced the cardiac risk of rats significantly.

• Structural Engineering and Mechanics
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• v.77 no.3
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• pp.355-368
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• 2021

The time-varying mean (TVM) component of non-stationary wind speeds is commonly extracted utilizing empirical mode decomposition (EMD) in practice, whereas the accuracy of the extracted TVM is difficult to be quantified. To deal with this problem, this paper proposes an approach to identify and extract the optimal TVM from several TVM results obtained by the EMD. It is suggested that the optimal TVM of a 10-min time history of wind speeds should meet both the following conditions: (1) the probability density function (PDF) of fluctuating wind component agrees well with the modified Gaussian function (MGF). At this stage, a coefficient p is newly defined as an evaluation index to quantify the correlation between PDF and MGF. The smaller the p is, the better the derived TVM is; (2) the number of local maxima of obtained optimal TVM within a 10-min time interval is less than 6. The proposed approach is validated by a numerical example, and it is also adopted to extract the optimal TVM from the field measurement records of wind speeds collected during a sandstorm event.

• Journal of Environmental Science International
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• v.30 no.7
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• pp.537-545
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• 2021

This study aimed to investigate the improvement effect of 5% (w/w) mung bean (Phaseolus aureus L.) on lipid composition and protein concentration in hyperlipidemic rats. Seven-week-old male (Sprague-Dawley) rats were divided into four groups (n=6, each), and fed experimental diets containing mung bean meal [basal diet+5% (w/w) mung bean (BM), basal-hyperlipidemic diet+5% (w/w) mung bean (BHM)], basal-hyperlipidemic diet (BH), and control (basal diet, BD). Lipid composition in the mung bean diet groups (BM and BHM) evidenced significant reductions in serum total cholesterol, low-density lipoprotein cholesterol, atherosclerotic index, cardiac risk factor, triglyceride, phospholipid, free cholesterol, cholesteryl ester, blood glucose, nonesterified fatty acid, and an elevation in high-density lipoprotein cholesterol. The serum albumin/globulin ratio was increased in mung bean diet-supplemented rats compared to that in hyperlipidemic rats (p < 0.05). Total calcium, phosphorus and potassium concentrations in sera were higher in the BM, BHM and BD groups than in the BH group. Concentrations of sodium and chlorine in sera were lower in the mung bean diet-supplemented groups than in the hyperlipidemic group. The in vivo experiments showed that ingestion of mung bean was effective in improving lipid composition, protein concentration, and blood glucose.

• Journal of Sasang Constitutional Medicine
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• v.13 no.3
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• pp.52-58
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• 2001

Purposes : As the population of old people has increased by the improvement of medical techniques, the concern on degenerative diseases has increased gradually. Especially the researches of osteoporosis have been carried out in view of prevention and treatment. But there wasn't any research related with Sasang Constitution. So we investigated the relation between Sasang Constitution and BMD(bone mineral density). Methods : Authors measured BMD and BMI(body mass index) of healthy women. We devided our subjects into Young age group and Old age group, and analyzed the data of Sasang Constitution subgroup. Results : 1. BMD of Taeumin was higher than those of Soyangin and Soeumin in Lumbar spine and Femoral neck in both Young and Old age group. In Old age group, there were significant differences in Taeumin vs Soeumin, and Soyangin vs Soeumin in BMD of Lumbar spine 2. BMI of Taeumin was higher than those of Soyangin and Soeumin in both Young and Old age group. In Young age group, there were significant differences in Taeumin vs Soyangin and Taeumin vs Soeumin. In Old age group, there were significant differences in Taeumin vs Soyangin, Taeumin vs Soeumin and Soyangin vs Soeumin. Conclusion : BMD and BMI of Taeumin was higher than those of Soyangin and Soeumin.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3758-3763
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• 2024

The current study aimed to evaluate the suitability of polyester resin as an alternative material to polymethyl methacrylate (PMMA) for computed tomography (CT) dosimetry phantoms using the GEANT4/GATE Monte Carlo simulation platform. Cylindrical phantoms (32 cm diameter) constructed of polyester resin and PMMA were simulated and compared in terms of atomic composition, effective atomic number, electron density, mass density, and photon interaction mechanisms. Weighted CT dose index (CTDIw) values were calculated for each phantom at 80, 110, and 130 kVp tube voltages based on measurements of CTDI_100,c and CTDI_100,p. Results demonstrated that the physical properties of polyester closely matched those of PMMA, and the polyester phantom displayed equivalent dosimetric behavior to the PMMA phantom at all tube voltages tested. CTDIw values from the polyester phantom were within 1.4 % of the PMMA phantom across all tube voltages. Conversion coefficients were derived to equate polyester CTDIw values to PMMA dose equivalents. This study found that a polyester resin phantom exhibited radiation dosimetry commensurate with the standard PMMA phantom for CT dose assessment. Consequently, polyester resin represents a viable substitute material when PMMA is unavailable for construction of CT dosimetry phantoms.

• Journal of the Korean Dietetic Association
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• v.3 no.2
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• pp.182-196
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• 1997

Physiological changes that affect nutrient absorption and utilization occur in older adults, and the collection of nutritional information is an important part of examining the nutrition and health issue. A nutritional survey using the 24-hour recall method was performed to identify nutritional quality and leading patterns of food group intake for protein, vitamin C, P and Fe were over 1, whereas those for vitamin A, $B_1$, $B_2$, niacin and Ca were below 1. The MAR(Mean Adequacy Ratio) was relatively low(0.75). The percentage of energy from carbohydrate, protein, and fat was 65.1, 15.6, and 19.5, respectively, thus the quantities of energy source were ideal. The Older subjects revealed poorer nutrition quality than the younger subjects did. The food group intake pattern of the elderly was not diverse, only 9% of them consumed all food groups in a day. These results suggest that nutritional guidelines for older Koreans should focus on the maintenance of adequate energy intake. In addition, selection of foods with high protein and calcium, such as dairy food, should be emphasized, particularly in the older elderly. Nutrition programs should target individuals at risk of not receiving enough nutrients, like the oldest elderly, and persons with lower education.

• Asian Journal of Innovation and Policy
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• v.6 no.1
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• pp.85-93
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• 2017

This paper focuses on the relationship between the characteristics of network and the productivity of scientists, which is rarely examined in previous studies. Utilizing a unique dataset from the Korean Citation Index (KCI), we examine the overall characteristics of the research network (e.g. distribution of nodes, density and mean distance), and analyze whether the network centrality is related to the scientific productivity. According to the results, firstly we have found that the collaborative research network of the Korean academics in the field of statistics and computer science is a scale-free network. Secondly, these research networks show a disciplinary difference. The network of statisticians is denser than that of computer scientists. In addition, computer scientists are located in a fragmented network compared to statisticians. Thirdly, with regard to the relationship between the researchers' network position and scientific productivity, a significant relation and their disciplinary difference have been observed. In particular, the degree centrality is the strongest predictor for the scientists' productivity. Based on these findings, some policy implications are put forward.

• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.10-25
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• 2018

This study was conducted to estimate the habitat suitability of 17 benthic macroinvertebrate taxa in the Hwayang stream. Habitat Suitability Index (HSI) of benthic macroinvertebrates from the Hwayang stream was developed based on three physical habitat factors which include current velocity, water depth, and the substrate. The Weibull model was used as a probability density function to analyze the distribution of individual abundance by physical factors. The number of species and the total individual abundance increased along with the increase in current velocity. By means of Canonical Correspondence Analysis (CCA), the relative importance of each factor was determined in the following order: current velocity, water depth, and the mean diameter. The results depicted that, the most influential factor in the growth of benthic macroinvertebrates in the Hwavang system was current velocity. After comparing the analyzed results from the Hwayang stream with the resukts from the Gapyeong stream, the integrated HSI was drawn. The results indicated that current velocity and substrate had similar distributions of HSI in the two streams. This was due to the addition of unmeasured data from previous surveys, or the fact that benthic macroinvertebrates adapted to deeper waters in the Hwayang Stream. Most taxa showed a clear preference for a fast current velocity, deep water depth and coarse substrate except Baetiella, Epeorus, (mayflies), and Hydropsyche (caddisfly).

• Clinical and Experimental Pediatrics
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• v.63 no.3
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• pp.110-114
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• 2020

Background: Subclinical hypothyroidism (SH) is a common condition in obese children. However, its effect on glucose and lipid metabolism in obese children remains controversial. Purpose: The present study aimed to investigate the association between SH and metabolic parameters. Methods: A total of 215 obese children and adolescents aged 6-18 years were included in this retrospective cross-sectional study. The patients' anthropometric measurements such as thyrotropin (TSH), free thyroxine (fT4), fasting plasma glucose, and insulin levels, as well as homeostasis model assessment for insulin resistance (HOMA-IR) index, and lipid profiles were evaluated. The patients were allocated to the SH group (fT4 normal, TSH 5-10 mIU/L) (n=77) or the control group (fT4 normal, TSH<5 mIU/L) (n=138). The glucose and lipid metabolisms of the 2 groups were compared. Results: SH was identified in 77 of 215 patients (36%). Mean body mass index was similar in both groups. The mean serum insulin, HOMA-IR, and triglyceride (TG) levels were higher and the mean high-density lipoprotein cholesterol level was lower in the SH group than in the control group (P=0.007, P=0.004, P=0.01, and P=0.02, respectively). A positive correlation was observed between TSH level and insulin level, HOMA-IR, and TG level. Conclusion: SH was identified in some of the obese children and adolescents. A clear association was observed between SH, insulin resistance, and dyslipidemia in obese children.