• Korean Journal of Radiology
• /
• v.24 no.2
• /
• pp.145-154
• /
• 2023

Objective: We aimed to evaluate the efficacy of EmboTrap II in terms of first-pass recanalization and to determine whether it could yield favorable outcomes. Materials and Methods: In this multicenter, prospective study, we consecutively enrolled patients who underwent mechanical thrombectomy using EmboTrap II as a front-line device. The primary outcome was the first pass effect (FPE) rate defined by modified Thrombolysis In Cerebral Infarction (mTICI) grade 2c or 3 by the first pass of EmboTrap II. In addition, modified FPE (mFPE; mTICI grade 2b-3 by the first pass of EmboTrap II), successful recanalization (final mTICI grade 2b-3), and clinical outcomes were assessed. We also analyzed the effect of FPE on a modified Rankin Scale (mRS) score of 0-2 at 3 months. Results: Two hundred-ten patients (mean age ± standard deviation, 73.3 ± 11.4 years; male, 55.7%) were included. Ninety-nine patients (47.1%) had FPE, and mFPE was achieved in 150 (71.4%) patients. Successful recanalization was achieved in 191 (91.0%) patients. Among them, 164 (85.9%) patients underwent successful recanalization by exclusively using EmboTrap II. The time from groin puncture to FPE was 25.0 minutes (interquartile range, 17.0-35.0 minutes). Procedure-related complications were observed in seven (3.3%) patients. Symptomatic intracranial hemorrhage developed in 14 (6.7%) patients. One hundred twenty-three (58.9% of 209 completely followed) patients had an mRS score of 0-2. Sixteen (7.7% of 209) patients died during the follow-up period. Patients who had successful recanalization with FPE were four times more likely to have an mRS score of 0-2 than those who had successful recanalization without FPE (adjusted odds ratio, 4.13; 95% confidence interval, 1.59-10.8; p = 0.004). Conclusion: Mechanical thrombectomy using the front-line EmboTrap II is effective and safe. In particular, FPE rates were high. Achieving FPE was important for an mRS score of 0-2, even in patients with successful recanalization.

• Journal of the Korean Society of Radiology
• /
• v.82 no.6
• /
• pp.1505-1523
• /
• 2021

Purpose Although chest CT has been discussed as a first-line test for coronavirus disease 2019 (COVID-19), little research has explored the implications of CT exposure in the population. To review chest CT protocols and radiation doses in COVID-19 publications and explore the number needed to diagnose (NND) and the number needed to predict (NNP) if CT is used as a first-line test. Materials and Methods We searched nine highly cited radiology journals to identify studies discussing the CT-based diagnosis of COVID-19 pneumonia. Study-level information on the CT protocol and radiation dose was collected, and the doses were compared with each national diagnostic reference level (DRL). The NND and NNP, which depends on the test positive rate (TPR), were calculated, given a CT sensitivity of 94% (95% confidence interval [CI]: 91%-96%) and specificity of 37% (95% CI: 26%-50%), and applied to the early outbreak in Wuhan, New York, and Italy. Results From 86 studies, the CT protocol and radiation dose were reported in 81 (94.2%) and 17 studies (19.8%), respectively. Low-dose chest CT was used more than twice as often as standard-dose chest CT (39.5% vs.18.6%), while the remaining studies (44.2%) did not provide relevant information. The radiation doses were lower than the national DRLs in 15 of the 17 studies (88.2%) that reported doses. The NND was 3.2 scans (95% CI: 2.2-6.0). The NNPs at TPRs of 50%, 25%, 10%, and 5% were 2.2, 3.6, 8.0, 15.5 scans, respectively. In Wuhan, 35418 (TPR, 58%; 95% CI: 27710-56755) to 44840 (TPR, 38%; 95% CI: 35161-68164) individuals were estimated to have undergone CT examinations to diagnose 17365 patients. During the early surge in New York and Italy, daily NNDs changed up to 5.4 and 10.9 times, respectively, within 10 weeks. Conclusion Low-dose CT protocols were described in less than half of COVID-19 publications, and radiation doses were frequently lacking. The number of populations involved in a first-line diagnostic CT test could vary dynamically according to daily TPR; therefore, caution is required in future planning.

• Information Systems Review
• /
• v.19 no.2
• /
• pp.1-19
• /
• 2017

Original scripts of e-learning lectures for the CEOs of corporation S were analyzed using topic analysis, which is a text mining method. Twenty-two topics were extracted based on the keywords chosen from five-year records that ranged from 2011 to 2015. Research analysis was then conducted on various issues. Promising topics were selected through evaluation and element analysis of the members of each topic. In management and economics, members demonstrated high satisfaction and interest toward topics in marketing strategy, human resource management, and communication. Philosophy, history of war, and history demonstrated high interest and satisfaction in the field of humanities, whereas mind health showed high interest and satisfaction in the field of in lifestyle. Studies were also conducted to identify topics on the proportion of content, but these studies failed to increase member satisfaction. In the field of IT, educational content responds sensitively to change of the times, but it may not increase the interest and satisfaction of members. The present study found that content production for CEOs should draw out deep implications for value innovation through technology application instead of simply ending the technical aspect of information delivery. Previous studies classified contents superficially based on the name of content program when analyzing the status of content operation. However, text mining can derive deep content and subject classification based on the contents of unstructured data script. This approach can examine current shortages and necessary fields if the service contents of the themes are displayed by year. This study was based on data obtained from influential e-learning companies in Korea. Obtaining practical results was difficult because data were not acquired from portal sites or social networking service. The content of e-learning trends of CEOs were analyzed. Data analysis was also conducted on the intellectual interests of CEOs in each field.

• Journal of Korean Dental Hygiene Science
• /
• v.6 no.2
• /
• pp.51-64
• /
• 2023

Background: This study was conducted to determine the association with dual jobbing on dental hygienists' job satisfaction and to identify the factors that lead to dual jobs. Methods: This study was an online survey of 110 currently employed dental hygienists conducted during the month of May 2022. To determine job satisfaction, we used the 20-item Korea-Minnesota Satisfaction Questionnaire (K-MSQ). Survey questions related to dual job were adapted and supplemented from the dual job survey instrument for dental hygienists to identify intention to dual job and future intention to dual job. Descriptive statistics, independent t-test, ANOVA and Scheffe's post hoc analysis, and multiple logistic regression were performed. Results: The dual job rate and future dual job rate of the participants in this study were about 27% and 47%, respectively. The means for Intrinsic job satisfaction, Extrinsic job satisfaction, and job satisfaction were 3.44, 3.15, and 3.36, respectively. It was statistically significant that extrinsic job satisfaction increased with increasing position, and intrinsic job satisfaction, extrinsic job satisfaction, and job satisfaction increased with increasing salary. Those currently working dual jobs cited "self-actualization" as a reason for doing so, and those who intended to work dual jobs in the future cited "not being paid enough in their primary job" as a reason. We found that a one-unit increase in intrinsic job satisfaction and job satisfaction increases the odds of future intention to dual job by about 1.07 and 1.05 times, respectively (p<0.05). Conclusion: This study confirmed the influence of dental hygienists' job satisfaction on intention to dual job and future intention to dual job, and self-actualization was found to be the main factor. Therefore, the consideration of dual jobs in the future will affect the improvement of dental hygienists as professionals and the reduction of turnover through better working conditions.

• Journal of Nutrition and Health
• /
• v.57 no.3
• /
• pp.292-306
• /
• 2024

Purpose: This study investigated fruit and vegetable intake and associated socio-demographic and dietary factors, and compared the nutritional intake according to the fruit and vegetable intake level among Korean adolescents. Methods: This study was conducted on 1,676 adolescents who participated in the 2016-2019 Korea National Health and Nutrition Examination Survey. The subjects were classified into four groups based on the fruit and vegetable intake recommendations in 2020 Dietary Reference Intakes for Koreans: Application (KDRIs Application): sufficient fruit intake (SF) group, sufficient vegetables intake (SV) group, sufficient fruit and vegetables intake (SFV) group, and not sufficient fruit and vegetable intake (NS) group The nutrient intake per day in each group was compared.. Logistic regression analysis was performed to examine the factors influencing fruit and vegetables intake. Results: In the sample of adolescents surveyed, only 1.40% met the recommended daily intake of fruits and vegetables, while 79.54% fell below the established threshold for adequate consumption. Female adolescents, those with fathers holding university degrees or above, and those who ate breakfast at least three times a week were likelier to have adequate fruit intake. Male adolescents and those from higher-income households were likelier to consume vegetables. Females, those who ate out daily, those from lower-income households, and those who understood food labels were likelier to have adequate fruit and vegetable intake. The daily nutrient intake and intake-to-requirement ratio significantly differed according to the fruit and vegetable intake groups. The NS and SF group had lower ratios for calcium and iron, while the NS group had the lowest vitamin A and C intake. By contrast, the SFV group met almost all daily nutrient requirements, except for calcium and vitamin A. Conclusion: This study highlights the need for nutrition education programs to encourage adolescents to consume adequate amounts of fruits and vegetables.

• Maritime Security
• /
• v.7 no.1
• /
• pp.31-60
• /
• 2023

This study proposes a new convergence weapon system that combines the covert placement and detection abilities of a self-propelled mobile mine with the rapid tracking and attack abilities of supercavitating rocket torpedoes. This innovative system has been designed to counter North Korea's new underwater weapon, 'Haeil'. The concept behind this convergence weapon system is to maximize the strengths and minimize the weaknesses of each weapon type. Self-propelled mobile mines, typically placed discreetly on the seabed or in the water, are designed to explode when a vessel or submarine passes near them. They are generally used to defend or control specific areas, like traditional sea mines, and can effectively limit enemy movement and guide them in a desired direction. The advantage that self-propelled mines have over traditional sea mines is their ability to move independently, ensuring the survivability of the platform responsible for placing the sea mines. This allows the mines to be discreetly placed even deeper into enemy lines, significantly reducing the time and cost of mine placement while ensuring the safety of the deployed platforms. However, to cause substantial damage to a target, the mine needs to detonate when the target is very close - typically within a few yards. This makes the timing of the explosion crucial. On the other hand, supercavitating rocket torpedoes are capable of traveling at groundbreaking speeds, many times faster than conventional torpedoes. This rapid movement leaves little room for the target to evade, a significant advantage. However, this comes with notable drawbacks - short range, high noise levels, and guidance issues. The high noise levels and short range is a serious disadvantage that can expose the platform that launched the torpedo. This research proposes the use of a convergence weapon system that leverages the strengths of both weapons while compensating for their weaknesses. This strategy can overcome the limitations of traditional underwater kill-chains, offering swift and precise responses. By adapting the weapon acquisition criteria from the Defense force development Service Order, the effectiveness of the proposed system was independently analyzed and proven in terms of underwater defense sustainability, survivability, and cost-efficiency. Furthermore, the utility of this system was demonstrated through simulated scenarios, revealing its potential to play a critical role in future underwater kill-chain scenarios. However, realizing this system presents significant technical challenges and requires further research.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.50 no.1
• /
• pp.59-65
• /
• 2024

For plasma cosmetics, it is important to ensure the long-term stability of plasma in the formulation. This study examined the suitability of containers for efficient plasma cosmetics development. By varying the surface area covered by the plasma, 4 cm², 25 cm², 75 cm², and 175 cm² containers were injected with cosmetic plasma, and the amount of nitric oxide (NO), the main active species of nitrogen plasma, was analyzed. As a result, the surface area and stability exposed to plasma tended to be inversely proportional, and it was most effective in a 4 cm² container. Furthermore, 25 mm, 40 mm, and 50 mm vials were treated with plasma, which resulted in relative long-term stability of NO at 25 mm, a smaller surface area of the container exposed to air. Water mist and stratified mist were selected as cosmetic formulations, and NO plasma was injected into the water layer to observe the changes in formulation properties and the state of the injected NO plasma. In both formulations, the amount of NO plasma injected was about 1.5 times higher in the water phase mist than in the stratified mist, and the stratified mist gradually decreased with time and was found to disappear after 3 weeks. The stability of the nitrogen plasma was studied at low temperature (4 ℃), room temperature (25 ℃), and high temperature (37 ℃, 50 ℃). As a result, it was found that the water mist did not affect the stability, but the stratified mist observed a color change in the oil phase layer. Overall, this study demonstrates the container suitability of nitrogen plasma and suggests the importance of ensuring the stability of injected nitrogen plasma in cosmetic formulations.

• Journal of the Korean Applied Science and Technology
• /
• v.41 no.2
• /
• pp.219-232
• /
• 2024

The aim of this study was to explore the impact of body mass index (BMI) and drumming exercise on autonomic nervous system function in adult women. Ten adult women (aged 30-50) were divided into two groups based on their BMI: a normal BMI group (Low BMI, LBMI < 23 kg/m²) and an overweight BMI group (High BMI, HBMI > 23 kg/m²). Both groups participated in a drumming exercise program, consisting of 50-minute sessions, three times a week, for a duration of 8 weeks. Body composition and heart rate variability were assessed before and after the 8-week exercise period. Heart rate variability was evaluated using linear analysis in the time domain and frequency domain. Additionally, non-linear analysis was conducted using a Poincaré plot. The autonomic nervous system index was determined by measuring parasympathetic nervous system index and sympathetic nervous system index. Following the 8-week intervention, the HBMI group exhibited a significant decrease in weight (p=0.034), BMI (p=0.044), body fat mass (p=0.032), and waist circumference (p=0.013) compared to the LBMI group. Furthermore, the HBMI group demonstrated significant increases in RMSSD (p=0.018) and TP (p=0.033) in linear analysis, as well as SD1 (p=0.018) in non-linear analysis and PNS Index (p=0.040) compared to the LBMI group. RMSSD, SD1, and PNS Index serve as indicators of parasympathetic nervous system activity in linear and non-linear analyses, respectively. These findings indicate that drumming exercise significantly enhances autonomic nervous system function in overweight women.

• Korean Journal of Radiology
• /
• v.2 no.1
• /
• pp.28-36
• /
• 2001

Objective: To provide a systematic overview of the effects of various parameters on contrast enhancement within the same population, an animal experiment as well as a computer-aided simulation study was performed. Materials and Methods: In an animal experiment, single-level dynamic CT through the liver was performed at 5-second intervals just after the injection of contrast medium for 3 minutes. Combinations of three different amounts (1, 2, 3 mL/kg), concentrations (150, 200, 300 mgI/mL), and injection rates (0.5, 1, 2 mL/sec) were used. The CT number of the aorta (A), portal vein (P) and liver (L) was measured in each image, and time-attenuation curves for A, P and L were thus obtained. The degree of maximum enhancement (Imax) and time to reach peak enhancement (Tmax) of A, P and L were determined, and times to equilibrium (Teq) were analyzed. In the computed-aided simulation model, a program based on the amount, flow, and diffusion coefficient of body fluid in various compartments of the human body was designed. The input variables were the concentrations, volumes and injection rates of the contrast media used. The program generated the time-attenuation curves of A, P and L, as well as liver-to-hepatocellular carcinoma (HCC) contrast curves. On each curve, we calculated and plotted the optimal temporal window (time period above the lower threshold, which in this experiment was 10 Hounsfield units), the total area under the curve above the lower threshold, and the area within the optimal range. Results: A. Animal Experiment: At a given concentration and injection rate, an increased volume of contrast medium led to increases in Imax A, P and L. In addition, Tmax A, P, L and Teq were prolonged in parallel with increases in injection time The time-attenuation curve shifted upward and to the right. For a given volume and injection rate, an increased concentration of contrast medium increased the degree of aortic, portal and hepatic enhancement, though Tmax A, P and L remained the same. The time-attenuation curve shifted upward. For a given volume and concentration of contrast medium, changes in the injection rate had a prominent effect on aortic enhancement, and that of the portal vein and hepatic parenchyma also showed some increase, though the effect was less prominent. A increased in the rate of contrast injection led to shifting of the time enhancement curve to the left and upward. B. Computer Simulation: At a faster injection rate, there was minimal change in the degree of hepatic attenuation, though the duration of the optimal temporal window decreased. The area between 10 and 30 HU was greatest when contrast media was delivered at a rate of 2 3 mL/sec. Although the total area under the curve increased in proportion to the injection rate, most of this increase was above the upper threshould and thus the temporal window was narrow and the optimal area decreased. Conclusion: Increases in volume, concentration and injection rate all resulted in improved arterial enhancement. If cost was disregarded, increasing the injection volume was the most reliable way of obtaining good quality enhancement. The optimal way of delivering a given amount of contrast medium can be calculated using a computer-based mathematical model.

• Journal of Korea Water Resources Association
• /
• v.57 no.6
• /
• pp.421-435
• /
• 2024

In April 2023, a wildfire broke out in Gangneung located in the east coast region due to the influence of the Yanggang-local wind. In this study, GIS-based RUSLE(Revised Universal Soil Loss Equation) and SEMMA (Soil Erosion Model for Mountain Areas) were used to evaluate the erosion rate due to vegetation recovery in a small watershed of the Gangneung WUI(Wildland-Urban Interface) fire. The small watershed of WUI fire has a low altitude range of 10-30 m and the average slope of 10.0±7.4° which corresponds to a gentle slope. The soil texture was loamy sand with a high organic content and the deep soil depth. As herbaceous layer regenerated profusely in the gully after the wildfire, the NDVI (Normalized Difference Vegetation Index) reached a maximum of 0.55. Simulation results of erosion rates showed that RUSLE ranged from 0.07-94.9 t/ha/storm and SEMMA ranged from 0.24-83.6 t/ha/storm. RUSLE overestimated the average erosion rate by 1.19-1.48 times compared to SEMMA. The erosion rates were estimated to be high in the middle slope where burned pine trees were widely distributed and the slope was steep and to be relatively low in the hollow below the gully where herbaceous layer recovers rapidly. SEMMA showed a rapid increase in erosion sensitivity under at certain vegetation covers with NDVI below 0.25 (Ic = 0.35) on post-fire hillslopes. Gentle slopes with high organic content and rapid recovery of natural vegetation had relatively low erosion rate compared to steep slopes. As subsequent infrastructure and human damages due to sediment disaster by heavy rain is anticipated in WUI fire areas, the research results may be used as basic data for targeted management and decision making on the implementation of emergency treatment after the wildfire.