• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1315-1323
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• 2018

We studied the carbonization due to the annealing condition of waste coffee powder for application as an active anode material for lithium-ion batteries (LIBs). The coffee powder used as an active anode material for LIBs was obtained from coffee beans, not from a coffee shells. The waste coffee powder was dried in air and heat-treated in an $Ar/H_2$ atmosphere to obtain a pore-forming activated carbon powder. The specific capacity of the sample annealed at $700^{\circ}C$ was still 303 mAh/g after 1000 cycles at a current density of 1000 mA/g and with a coulombic efficiency of over 99.5%. The number of pores and the pore size of the waste coffee powder were increased due to chemical treatment with KOH, which had the some effect as an increased specific surface area. The waste coffee powder is considered to be a very promising active anode material because of both its excellent electrochemical properties due to enhanced carrier conduction and its being a cost effective resource for use in LIBs.

• Journal of The Korean Society of Clinical Toxicology
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• v.19 no.1
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• pp.8-16
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• 2021

Purpose: This study was conducted to analyze the social factors influencing the 'authenticity of suicidal ideation' based post-suicidal care programs in emergency departments (EDs). Methods: This retrospective study was an analysis using the data of patients who had attempted suicide and visited the ED in tertiary urban hospitals from January 1, 2016, to December 31, 2018. The variables examined included gender, age, history of previous psychiatric disease, suicide method, and the number of previous attempts. Univariate and multivariate logistic regression analyses were conducted to identify factors influencing the registration rate for the community-based post-suicide care program. Results: Overall,1,460 suicides were analyzed, 177 (1.16%) showed a high authenticity of suicide. The social factors influencing the authenticity of suicide intent were the unmarried status of men and women, joblessness, history of mental illnesses, more than two previous suicide attempts, the influence of alcohol, and an attempt to commit suicide after midnight more specifically between 24:00 to 6:00 hours in the morning (p<.05). The factors influencing the severity of the condition of high authenticity suicide patients were low Glasgow coma scores (12 points or less), lactate levels, and oxygen saturation observed in the patients who were admitted to the intensive care unit for treatment and died (p<.05). Conclusion: The need for evidence-based preventive measures and early assessment tools at the emergency medicine level is emphasized to reduce the rate of suicide attempts. If the results of this study are used in the management of suicide prevention, the evaluation of the authenticity of suicide intent will be more likely to be made at the emergency medicine level, allowing the severity to be assessed earlier.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.123-133
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• 2021

In order to use Osmia cornifrons more effectively in apples, we investigated the pollination effect and nesting activity of O. cornifrons on 'Hongro', the middle-season cultivar, and 'Fuji', the late-season cultivar. There was a significant difference in the nesting activity and pollination effect of O. cornifrons depending on the apple cultivar. The nesting activity, rate of trap nesting, and reproduction in 'Fuji' were 2.5, 1.5, and 3.8 times greater than in 'Hongro', respectively. The pollination effect according to cultivar 'Fuji' was 1.6 times greater than that of 'Hongro' in the central fruit set. In terms of the quality of fruit, the asymmetry index of 'Fuji' was 2.5 times lower than that of 'Hongro', and the number of apple seeds of 'Fuji' was 1.9 times greater than that of 'Hongro'. The main reason for this result was the air temperature. The activity of O. cornifrons was most affected by air temperature (R2 = 0.578). It is expected that the nesting activity and pollination effect are great in 'Fuji' (17.4-24.1℃) when the temperature during the blooming period is higher than that of 'Hongro' (12.5-20.2℃). Our study provides important information on stable apple production for apple cultivators, and can be used as an evidence for changes in flora and insect fauna caused by climate change.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.100-118
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• 2021

In this study, PM accidents (1,603case) and bicycle accidents (14,672case) that occurred in the last three years were analyzed to determine the characteristics of PM traffic accidents. In particular, PM traffic accidents were divided into perpetrators and victims to determine the characteristics in detail. For PM accidents, the analysis was conducted on the status of each road grade, road type, weather condition, accident type, day and night occurrence, and vehicle type. The number of PM accidents that occurred in 2019 increased by 129%, and deaths increased by more than 200% compared to the previous year. The proportion of pedestrian accidents among PM traffic accidents was higher than that of bicycle accidents. Therefore, regulations on PM traffic are necessary. For the 20 deaths of PM, a detailed analysis was conducted to analyze the factors of traffic accidents. PM fatalities occurred in 50% of vehicle accidents, and 7 out of 10 vehicle accidents occurred at night. This is believed to have been caused by falling or overturning due to an obstacle, such as a depression in the road pavement or a speed bump.

• Journal of the Korean Society for information Management
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• v.38 no.1
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• pp.25-51
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• 2021

In this study, we tried to provide basic materials necessary for introduction of smart libraries by analyzing present conditions of its operation based on the actual conditions of digital materials. For this study, a survey of actual use of digital materials is conducted for digital material rooms of public libraries in nationwide and 213 persons in charge of digital materials. As a result of this study, the followings are found: first, 80.8% of those public libraries responding to the survey operate digital material rooms and average 1.75 person is in charge of managing digital materials and open type Wi-Fis are installed in those public libraties but only 11.3% of those libraries provide 5G services; second, it is found that the digital data which are owned by those public libraries most are video contents (63.8%), e-books (53.5%) and audio books (53.5%) in order. In addition average number of types of audio books 781, video contents 4,985, nonbook contents except for video 3,616 and other digital data 626. This study is a basic research for introduction of smart library and it is necessary to conduct another study of a plan for future revitalization of digital materials and librarians' awareness on introduction of smart library.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.567-573
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• 2020

The persimmon is commonly cultivated in temperate regions of the world, including China, Korea, Japan, Brazil, Turkey, and Italy. In some Asian cultures, consumers are aware of the health claims related to the persimmon and its functional ingredients. The rich phytochemistry of the persimmon has opened new avenues of research on diet-based regimens designed to cure various ailments. This study was conducted to identify the genotoxicity of immature green persimmon (Diospyros kaki THUNB.) extract (DKA). The bacterial reverse mutation assay, the chromosomal aberration assay, and the mammalian micronucleus test were performed to determine the DKA genotoxicity. The result of the bacterial reverse mutation assay revealed that the DKA did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537 and Escherichia coli WP2uvrA with or without metabolic activation of S9 mixture. The oral administration of DKA also caused no significant increase in the number of micronucleated polychromatic erythrocytes or in the mean ratio of polychromatic to total erythrocytes. In addition, DKA did not cause a significant chromosome aberration on CHL cells in the presence or absence of S9 activation. In conclusion, DKA could be considered as a reliable and safe functional food since no toxicity was found under the condition of this study.

• Journal of Biomedical Engineering Research
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• v.42 no.4
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• pp.150-158
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• 2021

Intracranial hemorrhage (ICH) refers to acute bleeding inside the intracranial vault. Not only does this devastating disease record a very high mortality rate, but it can also cause serious chronic impairment of sensory, motor, and cognitive functions. Therefore, a prompt and professional diagnosis of the disease is highly critical. Noninvasive brain imaging data are essential for clinicians to efficiently diagnose the locus of brain lesion, volume of bleeding, and subsequent cortical damage, and to take clinical interventions. In particular, computed tomography (CT) images are used most often for the diagnosis of ICH. In order to diagnose ICH through CT images, not only medical specialists with a sufficient number of diagnosis experiences are required, but even when this condition is met, there are many cases where bleeding cannot be successfully detected due to factors such as low signal ratio and artifacts of the image itself. In addition, discrepancies between interpretations or even misinterpretations might exist causing critical clinical consequences. To resolve these clinical problems, we developed a diagnostic model predicting intracranial bleeding and its subtypes (intraparenchymal, intraventricular, subarachnoid, subdural, and epidural) by applying deep learning algorithms to CT images. We also constructed a visualization tool highlighting important regions in a CT image for predicting ICH. Specifically, 1) 27,758 CT brain images from RSNA were pre-processed to minimize the computational load. 2) Three different CNN-based models (ResNet, EfficientNet-B2, and EfficientNet-B7) were trained based on a training image data set. 3) Diagnosis performance of each of the three models was evaluated based on an independent test image data set: As a result of the model comparison, EfficientNet-B7's performance (classification accuracy = 91%) was a way greater than the other models. 4) Finally, based on the result of EfficientNet-B7, we visualized the lesions of internal bleeding using the Grad-CAM. Our research suggests that artificial intelligence-based diagnostic systems can help diagnose and treat brain diseases resolving various problems in clinical situations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.163-170
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• 2021

This study was conducted to create a technology to remove acne bacteria with human-friendly materials. First, the Cutibacterium acnes (C. acnes) were adsorbed to the mica disc to grow, and then the biofilm was checked through an atomic microscope to see if the biofilm had grown. Based on the topographic image, the shape changed round, the size was 17% longer on average, and the phase value of the resonance frequency separating materials was observed as a single value, the biofilm grown by covering the extracellular polymeric substrate (EPS). As a result of processing 50 mM of amino acids in the matured biofilm, the concentration of C. acnes decreased when valine, serine, arginine and leucine were treated. Scanning with nanoindentation and AFM contact modes confirmed that the hardness of biofilms treated with Valine (Val) increased. This indicates that an AFM tip measured cell which may have more solidity than that of EPS. The experiment of fluorescent tagged to EPS displays an existence of EPS at the condition of 10 mM Val, but an inhibition of growth of EPS at the 50 mM Val. Number of C. acnes was also reduced above 10 mM of Val. Weak adhesion of biofilm generated from an inhibition of EPS formation seems to induce decrease of C. acnes. Accordingly, we elucidated that Val has an efficiency which eliminates C. acnes by approach of an inhibition of EPS.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.109-117
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• 2022

There has been an increasing number of studies on photovoltaic energy generation system in an offshore site with the largest energy generation efficiency, as increasing the researches and developments of renewable energies for use of offshore space and resources to replace existing fossil fuels and resolve environmental challenges. For installation and operation of floating photovoltaic systems in an offshore site with harsher environmental conditions, a stiffness of structural members comprising the total system must be reinforced to inland water spaces as dams, reservoirs etc., which have relatively weak condition. However, there are various limitations for the reinforcement of structural stiffness of the system, including producible size, total mass of the system, economic efficiency, etc. Thus, in this study, a floating breakwater is considered for reducing wave loads on the system and minimizing the reinforcement of the structural members. Wave reduction performances of floating breakwaters are evaluated, considering size and distance to the system. The wave loads on the system are evaluated using the higher-order boundary element method (HOBEM), considering the multi-body effect of buoys. Stresses on structural members are assessed by coupled analyses using the finite element method (FEM), considering the wave loads and hydrodynamic characteristics. As the maximum stresses on each of the cases are reviewed and compared, the effect of floating breakwater for floating photovoltaic system is checked, and it is confirmed that the size of breakwater has a significant effect on structural responses of the system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.620-631
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• 2022

This paper shows the numerical prediction of the change in oil outflow rate according to the orifice shape of a damaged ship by using the computational fluid dynamics (CFD) analysis method. It also provides discharge coefficients for various orifice shapes to be used in theoretical prediction approaches. The oil outflow from the model ship was analyzed using a multiphase flow method under the condition that the Froude and Reynolds number similitudes were satisfied. The present numerical results were verified by comparing them with the available experimental data. Along with the aspect ratio of the orifice and the wall thickness of the cargo tank, the effects of the orifice shapes defined by mathematical figures on the oil outflow were investigated. To consider more realistic situations, the investigation of the ef ect of the crushed iron plate around the damaged part was also included. The numerical results confirmed the change in oil outflow time for various shapes of the damaged part of the oil tank, and discharge coefficients that quantify the viscous effects of those orifice shapes were extracted. To verify the predicted discharge coefficients, they were applied to an oil spill estimation equation. As a result, a good agreement between the CFD and theoretical results was obtained.