• Journal of The Geomorphological Association of Korea
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• v.27 no.2
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• pp.65-80
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• 2020

This paper deals with risk assessment of life in a landslide-prone area by a GIS-based modeling method. Landslide susceptibility maps can provide a probability of landslide prone areas to mitigate or proper control this problems and to take any development plan and disaster management. A landslide inventory map of the study area was prepared based on past historical information and aerial photography analysis. A total of 550 landslides have been counted at the whole study area. The extracted landslides were randomly selected and divided into two different groups, 50% of the landslides were used for model calibration and the other were used for validation purpose. Eleven causative factors (continuous and thematic) such as slope, aspect, curvature, topographic wetness index, elevation, forest type, forest crown density, geology, land-use, soil drainage, and soil texture were used in hazard analysis. The correlation between landslides and these factors, pixels were divided into several classes and frequency ratio was also extracted. Eventually, a landslide susceptibility map was constructed using a logistic regression model based on entire events. Moreover, the landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract a success rate curve. Based on the results, logistic regression produced an 85.18% accuracy, so we believed that the model was reliable and acceptable for the landslide susceptibility analysis on the study area. In addition, for risk assessment, vulnerability scale were added for social thematic data layer. The study area predictive landslide affected pixels 2,000 and 5,000 were also calculated for making a probability table. In final calculation, the 2,000 predictive landslide affected pixels were assumed to run. The total population causalities were estimated as 7.75 person that was relatively close to the actual number published in Korean Annual Disaster Report, 2006.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.912-921
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• 2023

Genetic diversity analysis is crucial for maintaining and managing genetic resources. Several studies have examined the genetic diversity of Korean domestic chicken (KDC) populations using microsatellite markers, but it is difficult to capture the characteristics of the whole genome in this manner. Hence, this study analyzed the genetic diversity of several KDC populations using high-density single nucleotide polymorphism (SNP) genotype data. We examined 935 birds from 21 KDC populations, including indigenous and adapted Korean native chicken (KNC), Hyunin and Jeju KDC, and Hanhyup commercial KDC populations. A total of 212,420 SNPs of 21 KDC populations were used for calculating genetic distances and fixation index, and for ADMIXTURE analysis. As a result of the analysis, the indigenous KNC groups were genetically closer and more fixed than the other groups. Furthermore, Hyunin and Jeju KDC were similar to the indigenous KNC. In comparison, adapted KNC and Hanhyup KDC populations derived from the same original species were genetically close to each other, but had different genetic structures from the others. In conclusion, this study suggests that continuous evaluation and management are required to prevent a loss of genetic diversity in each group. Basic genetic information is provided that can be used to improve breeds quickly by utilizing the various characteristics of native chickens.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.42-60
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• 2024

This study analyzed the characteristics of mixed traffic flows with autonomous vehicles on highway weaving sections and assessed the safety of vehicle-following pairs based on surrogate safety indicators. The intelligent driver model (IDM) was utilized to emulate the driving behavior of autonomous vehicles, and the weaving sections were divided into lengths of 300 and 600 meters for analysis within a micro-traffic simulation (VISSIM). Although significant differences were found in the average speed, density, and headway between the two sections through t-test results, no significant differences were observed when comparing the number of conflicts per indicator and the vehicle-following pair. Four safety indicators were selected for the mixed traffic evaluation based on their ability to represent risk levels similar to those perceived by drivers. The safety analysis, based on the selected four indicators, determined that autonomous vehicles following other autonomous vehicles were the safest pairing. Future research should focus on integrating these indicators into a single comprehensive index for analysis.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.275-284
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• 2024

Worldwide, cardiovascular disease is the main cause of death, which accordingly increased by hyperlipidemia. Hyperlipidemia therapy can include lifestyle changes and medications to control cholesterol levels. Statins are the medications of the first choice for dealing with lipid abnormalities. Rosuvastatin founds to control high lipid levels by hindering liver production of cholesterol and to achieve the targeted levels of low-density lipoprotein cholesterol, another lipid lowering agents named ezetimibe may be used as an added therapy. Both rosuvastatin and ezetimibe have low bioavailability which will stand as barrier to decrease cholesterol levels, because of such depictions, formulations of this combined therapy in nanotechnology will be of a great assistance. Our study demonstrated preparations of nanoparticles of this combined therapy, showing their physical characterizations, and examined their behavior in laboratory conditions and vivo habitation. The mean particle size was uniform, polydispersity index and zeta potential of formulations were found to be in the ranges of (0.181-0.72) and (-13.4 to -6.24), respectively. Acceptable limits of entrapment efficiency were affirmed with appearance of spherical and uniform nanoparticles. In vitro testing showed a sustained release of drug exceeded 90% over 24 h. In vivo study revealed an enhanced dissolution and bioavailability from loaded nanoparticles, which was evidenced by calculated pharmacokinetic parameters using triton for hyperlipidemia induction. Stability studies were performed and assured that the formulations are kept the same up to one month. Therefore, nano formulations is a suitable transporter for combined therapy of rosuvastatin and ezetimibe with improvement in their dissolution and bioavailability.

• Geomechanics and Engineering
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• v.36 no.5
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• pp.417-426
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• 2024

Shield tunneling method is widely used to build tunnels in complex geological environment. Stability control of tunnel face is the key to the safety of projects. To improve the excavation efficiency or perform equipment maintenance, the excavation chamber sometimes is not fully filled with support medium, which can reduce the load and increase tunneling speed while easily lead to ground collapse. Due to the high risk of the face failure under non-fully support mode, the tunnel face stability should be carefully evaluated. Whether compressive air is required for compensation and how much air pressure should be provided need to be determined accurately. Based on the upper bound theorem of limit analysis, a non-fully support rotational failure model is developed in this study. The failure mechanism of the model is verified by numerical simulation. It shows that increasing the density of supporting medium could significantly improve the stability of tunnel face while the increase of tunnel diameter would be unfavorable for the face stability. The critical support ratio is used to evaluate the face failure under the nonfully support mode, which could be an important index to determine whether the specific unsupported height could be allowed during shield tunneling. To avoid of face failure under the non-fully support mode, several charts are provided for the assessment of compressed air pressure, which could help engineers to determine the required air pressure for face stability.

• Hip & pelvis
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• v.34 no.1
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• pp.10-17
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• 2022

Purpose: This study was conducted in order to assess changes in hip muscles by comparing results of preoperative and postoperative computed tomography (CT) in older patients who underwent surgery for treatment of hip fracture. Materials and Methods: A total of 50 patients (aged ≥65 years) who underwent surgery for treatment of intertrochanteric fractures (25 patients) and femoral neck fractures (25 patients) between February 2013 and February 2019 and underwent preoperative and postoperative pelvic CT were enrolled in the study. The cross-sectional area, attenuation and estimates of muscle mass of the gluteus medius, gluteus minimus, iliopsoas, and rectus femoris on the uninjured side were measured. Basic patient data (sex, age, height, weight, body mass index [BMI], bone mineral density [BMD], Harris hip score [HHS], and length of follow-up) were collected from medical records. Results: No significant differences in sex, age, height, weight, BMI, BMD, HHS, and length of follow-up were observed between the two groups. No significant difference in the cross-sectional areas and attenuations of gluteus medius and gluteus minimus was observed after surgery; however, a statistically significant decrease was observed in those of iliopsoas and rectus femoris after surgery. Lower estimates with statistical significance of muscle mass of the iliopsoas and rectus femoris were observed on postoperative CT. Conclusion: Muscle mass of the hip flexor (iliopsoas, rectus femoris) showed significant decreases on postoperative CT compared with preoperative CT. Based on these findings, selective strengthening exercise for hip flexor should be beneficial in rehabilitation of hip fractures.

• Korean Journal of Plant Resources
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• v.37 no.3
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• pp.270-306
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• 2024

This study investigated the diversity of 323 mung bean accessions from Korea, China, and India, along with six cultivars, using 22 agronomical traits. The standardized Shannon-Weaver index (H') for the qualitative traits ranged from 0.11 (terminal leaflet shape) to 0.98 (pubescence density of pod). Likewise, the coefficient of variation for the quantitative traits ranged from 8.76% (days to maturity (DM)) to 79.91% (lodging rate (LR)), indicating a wide genetic variance. Hypocotyl color, pod color, seed shape, and seed coat surface lust showed different distributions among Korean, Indian, and Chinese accessions. Chinese accessions had the highest average germination rate, DM, days from flowering to maturity, and one-hundred seeds weight, followed by Korean and Indian accessions, while the number of seeds per pod (SPP) displayed the opposite trend, with all except SPP showing significant variation (p < 0.05). Similarly, plant height, days to flowering, and number of pods per plant increased in the order of India > Korea > China, with LR showing the opposite trend (p < 0.05). The mung bean accessions were grouped into four major clusters using hierarchical cluster analysis supported by principal component analyses, and all of the quantitative traits showed significant variations between the clusters (p < 0.05). Generally, the mung bean accessions investigated in this study exhibited wide phenotypic trait variations, which could be beneficial for future genomics studies. Moreover, this study identified 77 accessions that outperformed the controls. Consequently, these superior accessions could provide a wide spectrum of options during the development of improved mung bean varieties.

• Clinical Nutrition Research
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• v.11 no.4
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• pp.289-301
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• 2022

This study was conducted to evaluate the associations between dietary diversity score (DDS) and cardiovascular risk factors in this population. In this cross-sectional study, 187 patients, aged 18-65 years with pemphigus vulgaris were included. DDS was assessed by a 24-hour dietary recall method. Anthropometric measures and biochemical parameters assessed according to standard protocols. Multivariate linear regression analyses used for detecting any associations between DDS and cardiovascular risk factors. The mean ± standard deviation age and body mass index of studied participants were (46.71 ± 11.49 years) and (27.83 ± 4.39 kg/m²) respectively. Our findings showed that a higher DDS intake was related with higher consumption of vegetables (p = 0.001), dairy products (p < 0.001), cereals (p = 0.002), red and processed meat (p < 0.001), sweets and desserts (p < 0.001). After controlling for confounding variables, the results showed positive associations between DDS and high-density lipoprotein cholesterol (HDL-C, β = 1.87, 95% confidence interval [CI], 0.30-3.45, p = 0.02) and total cholesterol (TC) levels (β = 6.41, 95% CI, 1.62-11.03, p = 0.02) (β = 1.75, 95% CI, 0.20-3.30, p = 0.02). However, there were no associations between DDS and prevalence of obesity and glucose homeostasis. The results of this cross-sectional study showed that DDS might be associated with increased HDL-C and TC. However, further prospective studies are needed to prove these findings.

• Structural Monitoring and Maintenance
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• v.11 no.3
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• pp.247-262
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• 2024

Domestic sewage can greatly affect the macro-micro physical-mechanical properties of building foundation soils. In order to investigate the effect of domestic sewage on physical and mechanical properties of soils, the physicochemical properties of three groups of different concentrations of domestic sewage contaminated soil were tested through indoor experiments. Combined with scanning electron microscopy, X-ray diffraction experiments, and grey relational analysis, the degree of influence of different concentrations of domestic sewage on the physicochemical properties of soil was compared and analyzed from multiple perspectives such as microstructure and mineral composition, revealing the influencing mechanism of soil pollution by domestic sewage. The results showed that under the immersion of contaminated water, the color of the soaking water turned black first and then yellow, and brownish yellow secretions appeared on the surface of the soil samples. The moisture content, specific gravity, density, and pore ratio index of the soil samples immersed in 50% and 100% domestic sewage decreased with the increase of sewage concentration, while the liquid limit of the soil samples changed in the opposite direction. The immersion time had little effect on the slope of the compression curve of the soil samples soaked in tap water. For the soil samples immersed in domestic sewage, the slope of the compression curve and the compression coefficient increased with the increase of domestic sewage concentration and immersion time, while the compression modulus showed the opposite trend. In the soil samples immersed in tap water, there were a large number of small particles and cementitious substances, and the structure was relatively dense. With the increase of domestic sewage concentration, the microstructure of the soil changed significantly, with the appearance of sigle particle structure, loose and disorderly arrangement of particles, increased and enlarged pores, gradual reduction of small particle substances and cementitious substances, and the soil structure transformed from compact to loose. The research findings can provide theoretical reference for contaminated geotechnical engineering.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3804-3811
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• 2024

The study focuses on creating new boro-silicate glasses doped with SnO₂ for radiation shielding. It examines how substituting Na₂O with SnO₂ affects their structural, optical, and shielding properties. Density increases from 2.406 to 2.488 g/cm³ with rising SnO₂, measured via the Archimedes Method. The examination for the glassy phase was performed using the XRD diffractometer. UV/Vis spectrophotometer analysis reveals reduced refractive index (2.412-1.976) and increased optical absorption-band gap (direct: 3.648-5.662 eV; indirect: 2.994-5.163 eV) with SnO₂ concentrations of 0-9 mol.%). The effectiveness of the radiation shielding was assessed over the 0.059-1.408 MeV gamma-ray energy interval. The analysis demonstrates that when the concentration of SnO₂ increases, the synthesized glasses' linear attenuation coefficient improves. As the SnO₂ content was raised between 0 and 9 mol%, the linear attenuation coefficient rose between 0.489 and 2.892 cm^-1 (at energy of 0.059 MeV) and between 0.126 and 0.128 cm^-1 (at energy of 1.408 MeV), respectively. As the SnO₂ content was raised between 0 and 9 mol%.