• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.146-146
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• 2022

A flash flood is one of the most hazardous natural events caused by heavy rainfall in a short period of time in mountainous areas with steep slopes. Early warning of flash flood is vital to minimize damage, but challenges remain in the enhancing accuracy and reliability of flash flood forecasts. The forecasters can easily determine whether flash flood is occurred using the flash flood guidance (FFG) comparing to rainfall volume of the same duration. In terms of this, the hydrological model that can consider the basin characteristics in real time can increase the accuracy of flash flood forecasting. Also, the predicted radar rainfall has a strength for short-lead time can be useful for flash flood forecasting. Therefore, using both hydrological models and radar rainfall forecasts can improve the accuracy of flash flood forecasts. In this study, FFG was applied to simulate some flash flood events in the Taehwa river basin by using of SURR model to consider soil moisture, and applied to the flash flood forecasting using predicted radar rainfall. The hydrometeorological data are gathered from 2011 to 2021. Furthermore, radar rainfall is forecasted up to 6-hours has been used to forecast flash flood during heavy rain in August 2021, Wulsan area. The accuracy of the predicted rainfall is evaluated and the correlation between observed and predicted rainfall is analyzed for quantitative evaluation. The results show that with a short lead time (1-3hr) the result of forecast flash flood events was very close to collected information, but with a larger lead time big difference was observed. The results obtained from this study are expected to use for set up the emergency planning to prevent the damage of flash flood.

• Journal of Industrial Convergence
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• v.21 no.8
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• pp.51-58
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• 2023

Blockchains have recently struggled to design for the ideal distributed trust networks by solving scalability trilemma. However, local conflicts between some countries lead to imbalance on energy distribution. Besides, blockchain networks (e.g., Bitcoin) currently consume enormous energy for transaction and mining. The existing data volume based trust model evaluated an increasing blockchain size better than Lubin's trust model in scalability trilemma. In this paper, we propose a scalability based energy model to evaluate sustainability for blockchain networks, considering energy consumption for transaction, time duration, and the blockchain size of growing blockchain networks. Through the rigorous numerical analysis, we compare the proposed scalability based energy model with the existing model for the satisfaction and optimal blockchain size. Thus, the scalability based energy model will provide an assessment tool to choose the proper blockchain networks to solve scalability trilemma problem and prove sustainability.

• Physical Therapy Rehabilitation Science
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• v.12 no.3
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• pp.229-239
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• 2023

Objective: Patients with chronic obstructive pulmonary disease (COPD) may experience reduced physical activity and quality of life (QoL) due to decreased pulmonary function. The purpose of this study was to investigate the level of pulmonary function, physical activity, and QoL of COPD patients. Design: Cross-sectional observational study. Methods: This study examined the published data of the Korea National Health and Nutrition Examination Survey in 2015-2019. Among 39,759 subjects who participated for 5 years, data from 151 patients diagnosed with COPD were analyzed separately. For the pulmonary function, the results of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV6, forced expiratory flow 25-75%, and peak expiratory flow were observed. Physical activity was identified as frequency and duration. For the QoL, EQ-5D-3L evaluation results were examined, and the frequency and index of the Korean version were investigated. Results: In pulmonary function, all variables were found to be lower than age and weighted matched normal values. COPD patients showed to perform very low levels of high/medium physical activity and sitting time was confirmed to be more than 8 hours a day. In QoL, it was found that the highest reporting rate of some problems was the "pain and discomfort" and "mobility". Conclusions: It was found that COPD patients showed that the prevalence of circulatory disease was relatively high, lowered pulmonary function, and QoL. These can be improved through regular physical activity, and it is thought that this can be achieved through optimization of pulmonary rehabilitation.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.1-8
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• 2023

In order to efficiently manage groundwater resources, it is necessary to establish clear definition about the rights to use groundwater because it directly governs the interests of various stakeholders, from users to policy makers. In this paper, we examined the characteristics of Korea's rights to use groundwater through legal precedents, public recognition, laws, and institutional stipulaton. Inclarity about the scope and definition of the right, and the absence of legal basis ruling the exclusion and duration of groundwater use have entailed numerous cases of legal disputes between the parties with incompetible interests. In the perception survey, various responses were obtained from the surveyee regarding the scope of rights perceived by groundwater users, how to respond to groundwater shortages, and opinions about expanding public uses of groundwater. In Korea, the legal authority to use groundwater is governed by different laws while considering groundwater as both private and public property. In foreign countires, the right to use water is separated from property ownership, and it limits the volume and pumping rate of groundwater during a specified period. In order to better manage groundwater resources, it is necessary to come up with a public consensus on the right to use groundwater by considering the opinions of various stakeholders and accomodating them in adminstrative effort in directing groundwater management.

• Journal of Korean Neurosurgical Society
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• v.66 no.6
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• pp.703-715
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• 2023

Objective : This retrospective study investigated the factors that affect cage obliquity angle despite orthogonal maneuvers performed during oblique lateral interbody fusion (OLIF) and assessed the relationship between cage obliquity angle and radiological outcomes post-surgery. Methods : Twenty-nine males who underwent L4-L5 OLIF for lumbar degenerative disease between 2019 and 2021 with a followup duration greater than 12 months were analyzed. Radiological parameters were measured including psoas muscle volume, total psoas area index (total psoas muscle area [cm²]/height squared [m²]), distance from the iliac artery to the origin of the psoas muscle (DIAPM), angle between the origin of the psoas muscle and the center of the vertebral disc (APCVD), iliac crest height, disc height, lumbar flexibility (lumbar flexion angle minus extension angle), cage location ratio, cage-induced segmental lumbar lordosis (LL) (postoperative index level segmental LL minus used cage angle), foraminal height changes, fusion grade. Results : DIAPM, APCVD, iliac crest height, postoperative index level segmental LL, and cage-induced segmental LL were significantly correlated with OLIF cage obliquity angle. However, other radiological parameters did not correlate with cage obliquity. Based on multiple regression analysis, the predictive equation for the OLIF cage obliquity angle was 13.062-0.318×DIAPM+0.325×1APCVD+0.174×iliac crest height. The greater the cage obliquity, the smaller the segmental LL compared to the cage angle used. Conclusion : At the L4-L5 level, OLIF cage obliquity was affected by DIAPM, APCVD, and iliac crest height, and as the cage obliquity angle increases, LL agnle achievable by the used cage could not be obtained.

• Korean Circulation Journal
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• v.53 no.5
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• pp.331-343
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• 2023

Background and Objectives: The prognostic implication of right atrial (RA) and left atrial (LA) size for an immediate success of direct current cardioversion (DCCV) in atrial fibrillation (AF) remains unclear. This study aimed to compare RA and LA size for the prediction of DCCV success. Methods: Between 2012 and 2018, 734 consecutive outpatients were screened for our prospective registry. Each eligible patient received a medical history, blood analysis, and transthoracic echocardiography with a focus on indexed RA (iRA) area and LA volume (iLAV) prior to DCCV with up to three biphasic shocks (200-300-360 J) or additional administration of amiodarone or flecainide to restore sinus rhythm. Results: We enrolled 589 patients, and DCCV was in 89% (n=523) successful. Mean age was 68 ± 10 years, and 40% (n=234) had New York heart association class >II. A prevalence of the male sex (64%, n=376) and of persistent AF (86%, n=505) was observed. Although DCCV success was associated with female sex (odds ratio [OR], 1.88; 95% confidence interval [CI], 1.06-3.65), with absence of coronary heart disease and normal left ventricular function (OR, 2.24; 95% CI, 1.26-4.25), with short AF duration (OR, 1.93; 95% CI, 1.05-4.04) in univariable regression, only iRA area remained a stable and independent predictor of DCCV success (OR, 0.27; 95% CI, 0.12-0.69; area under the curve 0.71), but not iLAV size (OR, 1.16; 95% CI, 1.05-1.56) in multivariable analysis. Conclusions: iRA area is superior to iLAV for the prediction of immediate DCCV success in AF.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.784-794
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• 2023

Objective: To determine whether dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) can be used to evaluate posterior cerebral circulation in pediatric patients with moyamoya disease (MMD) who underwent anterior revascularization. Materials and Methods: This study retrospectively included 73 patients with MMD who underwent DSC perfusion MRI (age, 12.2 ± 6.1 years) between January 2016 and December 2020, owing to recent-onset clinical symptoms during the follow-up period after completion of anterior revascularization. DSC perfusion images were analyzed using a dedicated software package (NordicICE; Nordic NeuroLab) for the middle cerebral artery (MCA), posterior cerebral artery (PCA), and posterior border zone between the two regions (PCA-MCA). Patients were divided into two groups; the PCA stenosis group included 30 patients with newly confirmed PCA involvement, while the no PCA stenosis group included 43 patients without PCA involvement. The relationship between DSC perfusion parameters and PCA stenosis, as well as the performance of the parameters in discriminating between groups, were analyzed. Results: In the PCA stenosis group, the mean follow-up duration was 5.3 years after anterior revascularization, and visual disturbances were a common symptom. Normalized cerebral blood volume was increased, and both the normalized time-topeak (nTTP) and mean transit time values were significantly delayed in the PCA stenosis group compared with those in the no PCA stenosis group in the PCA and PCA-MCA border zones. TTP_PCA (odds ratio [OR] = 6.745; 95% confidence interval [CI] = 2.665-17.074; P < 0.001) and CBV_PCA-MCA (OR = 1.567; 95% CI = 1.021-2.406; P = 0.040) were independently associated with PCA stenosis. TTP_PCA showed the highest receiver operating characteristic curve area in discriminating for PCA stenosis (0.895; 95% CI = 0.803-0.986). Conclusion: nTTP can be used to effectively diagnose PCA stenosis. Therefore, DSC perfusion MRI may be a valuable tool for monitoring PCA stenosis in patients with MMD.

• Steel and Composite Structures
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• v.51 no.3
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• pp.271-288
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• 2024

The primary objective of this study is to investigate the production and performance characteristics of structural concrete incorporating varying proportions (0%, 25%, and 50% by volume) of pumice stone, as well as aluminum lathe as an additive at 0%, 1%, 2%, and 3%, under fire conditions. The experiment will be conducted over a period of up to 1 hour, at temperatures ranging from 24℃, 200℃, 400℃ and 600℃. For the purpose of this, a total of twelve test samples were manufactured, and then tests of compressive strength (CS), splitting tensile strength (STS), and flexural strength (FS) were performed on these samples.Next, a comparison was made between the obtained values and the influence of temperature. To achieve this objective, the manufactured samples were placed at temperatures of 200℃, 400℃, and 600℃ for a duration of 1 hour, and were subjected to the influence of temperature.These values at 24 ℃ were then contrasted with the CS results obtained from test samples that were subjected to the temperature effect for an hour at 200 ℃, 400 ℃, and 600 ℃. A comprehensive analysis of the test outcomes reveals that the incorporation of aluminum lathe wastes into a mixture results in a significant reduction in the compressive strength of the concrete. As a result of this adjustment, the CS values dropped by 32.93%, 45.70%, and 52.07%, respectively. Furthermore, It was shown that testing the ratios of pumice stone alone resulted in a decrease in CS outcomes. Additionally, it was found that the presence of higher temperatures is clearly the primary factor contributing to the decrease in the strength of concrete. Due to elevated temperatures, the CS values decreased by 19.88%, 28.27%, and 38.61% respectively.After this investigation, an equation that explains the connection between CS and STS was provided through the utilization of the data of the experiments that were carried out.

• Journal of Chest Surgery
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• v.57 no.4
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• pp.342-350
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• 2024

Background: The maintenance of antiplatelet therapy increases the risk of bleeding during lung cancer surgery. Conversely, the perioperative interruption of antiplatelet therapy may result in serious thrombotic complications. This study aimed to investigate the safety of continuing antiplatelet therapy in the context of lung cancer surgery. Methods: We retrospectively reviewed a cohort of 498 elderly patients who underwent surgery for lung cancer. These patients were categorized into 2 groups: group N, which did not receive antiplatelet therapy, and group A, which did. Group A was subsequently subdivided into group Am, where antiplatelet therapy was maintained, and group Ai, where antiplatelet therapy was interrupted. We compared the incidence of bleeding-related and thrombotic complications across the 3 groups. Results: There were 387 patients in group N and 101 patients in group A (Ai: 70, Am: 31). No significant differences were found in intraoperative blood loss, thoracotomy conversion rates, transfusion requirements, volume of chest tube drainage, or reoperation rates for bleeding control between groups N and A or between groups Am and Ai. The duration of hospital stay was longer for group A compared to group N (7 days vs. 6 days, p=0.005), but there was no significant difference between groups Ai and Am. The incidence of cardiovascular or cerebrovascular complications did not differ significantly between groups Ai and Am. However, group Ai included a severe case of in-hospital ST-elevation myocardial infarction. Conclusion: The maintenance of antiplatelet therapy was found to be safe in terms of perioperative bleeding and thrombotic complications in elderly lung cancer surgery patients.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.101-120
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• 2024

Purpose : This study aimed to carry out a scoping review to investigate the research trends in non-pharmacological interventions for physical rehabilitation following breast cancer treatment. Methods : A scoping review was conducted according to the five steps outlined by Arksey and O'Malley and PRISMA-ScR. We searched three domestic databases (ScienceOn, Riss, KCI) and two international databases (PubMed, Cochrane Central) between January 2014 and April 2024. The keywords used were 'breast cancer surgery', 'breast cancer treatment', 'breast cancer lymphedema', 'intervention', 'management', 'therapy', 'disorder', and 'dysfunction'. Results : In terms of publication, the number of studies in the past five years has increased compared to the previous five years, with most studies focusing on patients aged 41 to 60 and who underwent surgical treatment for breast cancer. A total of 43 different types of non-pharmacological interventions were applied: 21 single interventions and 22 combination interventions. Among the intervention methods, complete decongestive treatment (CDT), resistance training, and manual lymphatic drainage were the most frequently utilized. The most common duration of intervention turned out to be 4~5 weeks and more than 8 weeks, with frequencies of 2~3 sessions per week and more than 4 sessions per week. The most frequently used dependent variables included range of motion (ROM) and disabilities of the arm, shoulder and hand (DASH) for the function and disorder of the upper limb category; arm circumference or volume and bio-impedance for the lymphedema category; visual analogue scale (VAS) and numerical rating scale (NRS) for the pain category; and the European organization for research and treatment of cancer quality of life questionnaire breast cancer module (EORTC QLQ) and functional assessment of cancer therapy-breast (FACT-B) for the quality of life category. Conclusion : The findings of this scoping review provide valuable mapping data for non-pharmacological interventions for physical rehabilitation following breast cancer treatment. We recommend further research, particularly systematic reviews and meta-analyses, to build upon these findings.