• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.79-88
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• 2024

We used actual field data to analyze from a traffic engineering perspective how AI and edge computing technologies affect the reduction of traffic accidents. By providing object information from 20m behind with AI object recognition, the driver secures a response time of about 3.6 seconds, and with edge technology, information is displayed in 0.5 to 0.8 seconds, giving the driver time to respond to intersection situations. In addition, it was analyzed that stopping before entering the intersection is possible when speed is controlled at 11-12km at the 10m point of the intersection approach and 20km/h at the 20m point. As a result, it was shown that traffic accidents can be reduced when the high object recognition rate of AI technology, provision of real-time information by edge technology, and the appropriate speed management at intersection approaches are executed simultaneously.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.1
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• pp.9-16
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• 2024

Using the proper orthogonal decomposition (POD) based intrusive reduced order model (ROM), the total degrees of freedom of the structural system can be significantly reduced and the critical time step satisfying the conditional stability increases in the explicit time integrations. In this study, therefore, the changes in the critical time step in the explicit time integrations are investigated using both the POD-ROM and Voronoi-cell lattice model (VCLM). The snapshot matrix is composed of the data from the structural response under the arbitrary dynamic loads such as seismic excitation, from which the POD-ROM is constructed and the predictive capability is validated. The simulated results show that the significant reduction in the computational time can be achieved using the POD-ROM with sufficiently ensuring the numerical accuracy in the seismic analyses. In addition, the validations show that the POD based intrusive ROM is compatible with the Voronoi-cell lattice based explicit dynamic analyses. In the future study, the research results will be utilized as an elemental technology for the developments of the real-time predictive models or monitoring system involving the high-fidelity simulations of structural dynamics.

• Applied Chemistry for Engineering
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• v.35 no.1
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• pp.16-22
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• 2024

Polymer electrolyte membrane fuel cells have the advantage of low operating temperatures and fast startup and response characteristics compared to others. Simulation studies are actively researched because their cost and time benefits. In this study, the resistance of water residual in the gas diffusion layer (GDL) of the unit cell was added to the existing equation to compare the actual data with the model data. The experiments were conducted with a 25 cm² unit cell, and the samples were separated into stopping times of 0, 10, and 60 minutes following primary impedance measurement, activation, and polarization curve data acquisition. This gives 0, 10, and 60 minutes for the residual water in the GDL to evaporate. Without the rest period, the magnitude of the performance improvement was not significantly different at the same potential and flow rate, but the rest period did improve the performance of the membrane electrode assembly when measuring impedance. By changing the magnitude of the resistance reduction to an overvoltage, the voltage difference between the fuel cell model with and without residual water was compared, and the error rate in the high current density region, which is dominated by concentration losses, was reduced.

• The Journal of Korean Obstetrics and Gynecology
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• v.37 no.1
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• pp.89-103
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• 2024

Objectives: This study analyzed an online survey targeting women and Korean medicine doctors who participated in the Yeosu City Postpartum Health Center Support Project. Through this, we would like to discuss the direction of support for postpartum health care support projects and new policies to encourage childbirth. Methods: In this study, we examined the results of an online survey from 73 women and 29 Korean medicine doctors. We examined 39 items, including basic information, childbirth-related items, Korean medicine treatment-related items, business satisfaction, and policies, answered by 73 women and 29 Korean medicine doctors who responded to the online survey. Results: The average age of women was 33.62±4.19 years, and the average age of Korean medicine doctors was 49.82±8.60 years. Musculoskeletal pain appeared most commonly in both maternal and Korean medicine doctors' online surveys. The visit date from the date of delivery was 36.87±27.06 days. Gungguijohyeol-um and Boheo-tang were widely used. The survey score of women whose main symptoms improved after taking herbal medicine was 3.04±1.15 points, and the survey score of Korean medical doctors was 4.13±0.74 points. The positive response to the policy was 73.7% for satisfaction with the overall policy to encourage childbirth, 54.8% for perceived support, and 65.7% for reduction of economic burden. Conclusions: Women who participated in the postpartum health care support project and received Korean medicine treatment and Korean medicine doctors who performed Korean medicine treatment were very satisfied. The most frequent postpartum symptom was musculoskeletal pain. The degree of improvement in main symptoms after taking herbal medicine was higher among Korean medicine doctors than among women. Among childbirth policies, the areas that should be prioritized are childbirth support projects and postpartum care projects.

• Animal Bioscience
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• v.37 no.8
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• pp.1452-1462
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• 2024

Objective: This study aimed to investigate the effects of dietary supplementation with Agaricus blazei polysaccharide (ABP) at varying concentrations on the performance, egg quality, blood biochemistry, intestinal morphology, and microflora of quail. Methods: The study involved a total of 2,700 Korean quails, which were randomly divided into three groups. The measured variables encompassed productive performance, egg parameters, carcass parameters, serum metabolites, immune response parameters, antioxidative properties, and gut microbiome. Results: The addition of ABP did not have a significant effect on average daily feed intake. However, it was found to increase the average daily egg weight and egg production rate, reduce the feed-egg ratio. There were no significant impacts on egg quality measures such as egg shape index, egg yolk index and color, egg yolk and protein content. However, ABP supplementation significantly increased the Hough unit (p<0.01) and decreased the rate of unqualified eggs (p<0.01). Regarding serum parameters, the inclusion led to an increase in total protein concentration (p<0.05) and a reduction in low-density lipoprotein cholesterol (p<0.05). There were no significant effects observed on immune indicators such as immunoglobulin A (IgA) and IgM. ABP supplementation increased the levels of serum antioxidant indicators, including glutathione peroxidase, total superoxide dismutase (p<0.05), and total antioxidant capacity colorimeter (p<0.05). Furthermore, ABP supplementation significantly elevated the intramuscular fatty acid content in quail meat. Additionally, ABP supplementation demonstrated a significant improvement in the diversity of gut microbiota and induced alterations in the composition of the gut microbiota. Conclusion: The findings of this study indicate that dietary supplementation of ABP enhanced production performance and antioxidant capacity while increasing the levels of polyunsaturated fatty acids in quail muscle.

• Structural Engineering and Mechanics
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• v.90 no.6
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• pp.611-633
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• 2024

This study intends to investigate the response of multi-cell (MC) beams to flexural loads in which the primary reinforcement is composed of both metallic and non-metallic materials. "Multi-cell" describes beam sections with multiple longitudinal voids separated by thin webs. Seven reinforced concrete MC beams measuring 300×200×1800 mm were tested under flexural loadings until failure. Two series of beams are formed, depending on the type of main reinforcement that is being used. A control RC beam with no openings and six MC beams are found in these two series. Series one and two are reinforced with metallic and non-metallic main reinforcement, respectively, in order to maintain a constant reinforcement ratio. The first crack, ultimate load, deflection, ductility index, energy absorption, strain characteristics, crack pattern, and failure mode were among the structural parameters of the beams under investigation that were documented. The primary variables that vary are the kind of reinforcing materials that are utilized, as well as the kind and quantity of mesh layers. The outcomes of this study that looked at the experimental and numerical performance of ferrocement reinforced concrete MC beams are presented in this article. Nonlinear finite element analysis (NLFEA) was performed with ANSYS-16.0 software to demonstrate the behavior of composite MC beams with holes. A parametric study is also carried out to investigate the factors, such as opening size, that can most strongly affect the mechanical behavior of the suggested model. The experimental and numerical results obtained demonstrate that the FE simulations generated an acceptable degree of experimental value estimation. It's also important to demonstrate that, when compared to the control beam, the MC beam reinforced with geogrid mesh (MCGB) decreases its strength capacity by a maximum of 73.33%. In contrast, the minimum strength reduction value of 16.71% is observed in the MC beams reinforced with carbon reinforcing bars (MCCR). The findings of the experiments on MC beams with openings demonstrate that the presence of openings has a significant impact on the behavior of the beams, as there is a decrease in both the ultimate load and maximum deflection.

• Ecology and Resilient Infrastructure
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• v.11 no.2
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• pp.23-34
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• 2024

Sediment, aquifer materials, surface water, and groundwater from brackish Songji lake affected by salinity of seawater, were collected and a pilot scale column experiment was conducted to simulate the nitrogen transport through the hyporheic zone. Upstream experiments of groundwater displayed that groundwater containing a small amount of salt percolated into aquifers and sediments, maintaining low dissolved oxygen concentrations. In addition, partial denitrification occurred in the aquifer due to salinity and low dissolved oxygen, resulting in the accumulation of NO₂^-. In sediments,nitrogenous compounds were reduced due to adsorption by long residence times or microbial-mediated oxidation/reduction reactions. Downstream experiments of surface water displayed that surface water from the brackish lake, containing high concentrations of dissolved oxygen and salts, infiltrated into the sediments and aquifer, supplying high dissolved oxygen concentrations. This resulted in biological nitrification in the sediments and aquifer, which reduced nitrogen-based pollutants despite the high salt concentration in the surface water. Whereas partial denitrification at low dissolved oxygen concentrations in the upwelling mixing zone was observed by salinity and accumulated NO₂^-, nitrification at high dissolved oxygen concentrations in the downwelling mixing zone was not significantly affected by salinity. These results confirm that salinity in the brackish water lake has some influence on the nitrogen behavior of the hyporheic mixing zone, although nitrogen behavior is a complex combination of factors such as DO, pH, substrate concentration, and organic matter concentration.

• Journal of Korea Port Economic Association
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• v.40 no.3
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• pp.27-45
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• 2024

This study analyzed the problems and promotion plans of shipping finance for eco-friendly ships to respond to marine pollution reduction regulations. The overall level of awareness of the problems of eco-friendly ship financing was found to be average(4.0~4.53), as the demand for construction and introduction of eco-friendly ships is not yet high. However, the response to the item about shipping fiance companies' lack of awareness of the importance of eco-friendly ships was low at 3.35. In the plan to promote eco-friendly ship finance, The need for security token offering(STO) and converting financial settlement to Korean won were low. Issuance of green bonds, creation of sovereign wealth fund(SWF), utilization of pension and superannuation fund, accelerated depreciation after construction, interest subsidy of government, establishment of a shipping exchange(promoting the introduction of eco-friendly ships), and development of eco-friendly ship supply chain connections were evaluated slightly higher than average. However, it was found that there is a high need for supporting shipping subsidies, providing special benefits for financial institutions, strengthening credit guarantees, reviving tax benefits for ship investment funds, providing incentives for early retirement vessels, establishing cooperative networks, supporting research and development, and establishing standards for operation eco-friendly ships. However, in seven promotion plans, such as strengthening credit guarantees, the level of awareness of shipping companies was statistically significantly higher than that of shipping fiancé companies.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.4
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• pp.363-374
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• 2022

Backgrounds/Aims: To analyze the results of the neoadjuvant treatment of patients in our center with early pancreatic cancer. Methods: Eighty-four patients with early pancreatic cancer (I-II) were included, of which 59 were considered "bioborderline" (carbohydrate antigen [CA] 19-9 > 37 U/L), and 25 were considered "non-bioborderline" (CA19-9 < 37 U/L). The R0 resection rate, presence of negative nodes, survival, and recurrence rates were analyzed in two groups, the NEO group (neoadjuvant + surgery) and the nonNEO group (upfront surgery). Results: A 28.6% pathologic complete response was observed in the NEO group of the whole sample. The residual R0 was 85.7%, and nodes were negative in 78.6% of the patients in the NEO group of bioborderline patients. All non-bioborderline patients treated with neoadjuvant were R0, and no affected nodes were observed in any of them. The median overall survival (OS) in patients with elevated CA19-9 levels in the NEO group was 31.4 months vs. 13.1 months in the non-NEO (log-rank test p = 0.006), with a 62% relative reduction in the mortality rate (hazard ratio = 0.38, 95% confidence interval: 0.20-0.79; p= 0.008). The median OS in patients with normal CA19-9 levels in the NEO group was 65.9 months vs. 16.2 months in the non-NEO group, without statistically significant differences between the two but with a trend toward significance (log-rank test p = 0.08). Conclusions: A neoadjuvant strategy seemed to improve local control and the survival of patients with early pancreatic cancer, both those with elevated CA19-9 and normal marker levels.

• Journal of Web Engineering
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• v.14 no.19
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• pp.4103-4118
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• 2022

The physiological or dietary advantages of germinated grains have been the subject of numerous discussions over the past decade. Around 23 million tons of oats are consumed globally, making up a sizeable portion of the global grain market. Oat seedlings contain more protein, beta-glucan, free amino acids, and phenolic compounds than seeds. The progressive neurodegenerative disorder of Alzheimer's is accompanied by worsening memory and cognitive function. A key indicator of this disorder is the unusual buildup of amyloid-beta protein (or Aβ) in human brains. In this context, oat seedling extract (OSE) has been identified as a new therapeutic candidate for AD, due to its antioxidant activity and AD-specific mechanism of action. This study directly investigated how OSE affected AD and its impacts by examining the cognitive function and exploring the inflammatory response mechanism. The dried oat seedlings were grounded finely with a grinder, inserted with 50% fermented ethanol 10 times (w/v), and extracted by stirring for 10 h at 45 ℃. After filtering the extract by 0.22 um filter, some of it was used for UHPLC analysis. The results indicated that the treatment with OSE protects against Aβ25-35-induced cytotoxicity in BV2 cells. Tg-5Xfad AD mice had strong deposition of Aβ throughout their brains, while WT mice did not exhibit any such deposition within their brains. A drastic reduction was observed in terms of numbers, as well as the size, of Aβ plaques within Tg-5Xfad AD mice exposed to OSE. This study indicated OSE's neuroprotective impacts against neurodegeneration, synaptic dysfunction, and neuroinflammation induced by amyloid-beta. Our results suggest that OSE acts as a neuroprotective agent to combat AD-specific apoptotic cell death, neuroinflammation, amyloid-beta accumulation, as well as synaptic dysfunction in AD mice's brains. Furthermore, the study indicated that OSE treatment affects JNK/ERK/p38 MAPK signaling, with considerable inhibition in p-JNK, p-p38, and p-ERK levels seen in the brain of OSE-treated Tg-5Xfad AD mice.