• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.51-59
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• 2021

Objective : Several studies have reported inconsistent findings among countries on whether off-hour hospital presentation is associated with worse outcome in patients with acute stroke. However, its association is yet not clear and has not been thoroughly studied in Korea. We assessed nationwide administrative data to verify off-hour effect in different subtypes of acute stroke in Korea. Methods : We respectively analyzed the nationwide administrative data of National Emergency Department Information System in Korea; 7144 of ischemic stroke (IS), 2424 of intracerebral hemorrhage (ICH), and 1482 of subarachnoid hemorrhage (SAH), respectively. "Off-hour hospital presentation" was defined as weekends, holidays, and any times except 8:00 AM to 6:00 PM on weekdays. The primary outcome measure was in-hospital mortality in different subtypes of acute stroke. We adjusted for covariates to influence the primary outcome using binary logistic regression model and Cox's proportional hazard model. Results : In subjects with IS, off-hour hospital presentation was associated with unfavorable outcome (24.6% off hours vs. 20.9% working hours, p<0.001) and in-hospital mortality (5.3% off hours vs. 3.9% working hours, p=0.004), even after adjustment for compounding variables (hazard ratio [HR], 1.244; 95% confidence interval [CI], 1.106-1.400; HR, 1.402; 95% CI, 1.124-1.747, respectively). Off-hours had significantly more elderly ≥65 years (35.4% off hours vs. 32.1% working hours, p=0.029) and significantly more frequent intensive care unit admission (32.5% off hours vs. 29.9% working hours, p=0.017) than working hours. However, off-hour hospital presentation was not related to poor short-term outcome in subjects with ICH and SAH. Conclusion : This study indicates that off-hour hospital presentation may lead to poor short-term morbidity and mortality in patients with IS, but not in patients with ICH and SAH in Korea. Excessive death seems to be ascribed to old age or the higher severity of medical conditions apart from that of stroke during off hours.

• Journal of Radiation Protection and Research
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• v.48 no.1
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• pp.28-43
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• 2023

Background: High-fidelity meteorological data is a prerequisite for the realistic simulation of atmospheric dispersion of radioactive materials near nuclear power plants (NPPs). However, many meteorological models frequently overestimate near-surface wind speeds, failing to represent local meteorological conditions near NPPs. This study presents a new high-resolution (approximately 1 km) meteorological downscaling method for modeling short-range (< 100 km) atmospheric dispersion of accidental NPP plumes. Materials and Methods: Six considerations from literature reviews have been suggested for a new dynamic downscaling method. The dynamic downscaling method is developed based on the Weather Research and Forecasting (WRF) model version 3.6.1, applying high-resolution land-use and topography data. In addition, a new subgrid-scale topographic drag parameterization has been implemented for a realistic representation of the atmospheric surface-layer momentum transfer. Finally, a year-long simulation for the Kori and Wolsong NPPs, located in southeastern coastal areas, has been made for 2016 and evaluated against operational surface meteorological measurements and the NPPs' on-site weather stations. Results and Discussion: The new dynamic downscaling method can represent multiscale atmospheric motions from the synoptic to the boundary-layer scales and produce three-dimensional local meteorological fields near the NPPs with a 1.2 km grid resolution. Comparing the year-long simulation against the measurements showed a salient improvement in simulating near-surface wind fields by reducing the root mean square error of approximately 1 m/s. Furthermore, the improved wind field simulation led to a better agreement in the Eulerian estimate of the local atmospheric dispersion. The new subgrid-scale topographic drag parameterization was essential for improved performance, suggesting the importance of the subgrid-scale momentum interactions in the atmospheric surface layer. Conclusion: A new dynamic downscaling method has been developed to produce high-resolution local meteorological fields around the Kori and Wolsong NPPs, which can be used in short-range atmospheric dispersion modeling near the NPPs.

• Journal of the Korea Safety Management & Science
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• v.26 no.3
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• pp.51-57
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• 2024

The purpose of this study is to compare and analyze the impact range of explosion damage due to gas leaks at LPG filling stations, focusing on propane and butane, which are components of vehicle LPG. The scenarios were designed based on the explosion incident at an LPG filling station in Gangwon-do, where an actual gas leak accident occurred, resulting in Scenario I and Scenario II. The ALOHA program, developed by the U.S. National Oceanic and Atmospheric Administration (NOAA), was used as the tool to analyze the impact range of the explosion damage for both substances. The results of the study indicated that, under identical conditions, propane had a wider impact range of damage than butane. This is presumed to be due to the greater explosion energy of propane, attributable to its physicochemical properties. Therefore, when preparing for LPG leak accidents, measures for propane need to be prioritized. As safety measures for propane, two suggestions were made to minimize human casualties. First, from a preventive perspective, it is suggested to educate workers about propane. Second, from the perspective of response measures and damage minimization, it is suggested to thoroughly prepare emergency evacuation and rescue plans, evacuation routes, designated shelters, and emergency response teams. This study compares and analyzes the impact range of radiative heat damage based on LPG components. However, hazardous accidents are critically influenced by the type of leaking substance, the form of the leak, and meteorological factors affecting the diffusion pattern of the substance. Therefore, for future research, it is proposed to model various leakage scenarios for the same substance to conduct a comprehensive risk assessment.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.47-55
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• 2015

Recently, the environment of a hospital information system is a trend to combine various SMART technologies. Accordingly, various smart devices, such as a smart phone, Tablet PC is utilized in the medical information system. Also, these environments consist of various applications executing on heterogeneous sensors, devices, systems and networks. In these hospital information system environment, applying a security service by traditional access control method cause a problems. Most of the existing security system uses the access control list structure. It is only permitted access defined by an access control matrix such as client name, service object method name. The major problem with the static approach cannot quickly adapt to changed situations. Hence, we needs to new security mechanisms which provides more flexible and can be easily adapted to various environments with very different security requirements. In addition, for addressing the changing of service medical treatment of the patient, the researching is needed. In this paper, we suggest a dynamic approach to medical information systems in smart mobile environments. We focus on how to access medical information systems according to dynamic access control methods based on the existence of the hospital's information system environments. The physical environments consist of a mobile x-ray imaging devices, dedicated mobile/general smart devices, PACS, EMR server and authorization server. The software environment was developed based on the .Net Framework for synchronization and monitoring services based on mobile X-ray imaging equipment Windows7 OS. And dedicated a smart device application, we implemented a dynamic access services through JSP and Java SDK is based on the Android OS. PACS and mobile X-ray image devices in hospital, medical information between the dedicated smart devices are based on the DICOM medical image standard information. In addition, EMR information is based on H7. In order to providing dynamic access control service, we classify the context of the patients according to conditions of bio-information such as oxygen saturation, heart rate, BP and body temperature etc. It shows event trace diagrams which divided into two parts like general situation, emergency situation. And, we designed the dynamic approach of the medical care information by authentication method. The authentication Information are contained ID/PWD, the roles, position and working hours, emergency certification codes for emergency patients. General situations of dynamic access control method may have access to medical information by the value of the authentication information. In the case of an emergency, was to have access to medical information by an emergency code, without the authentication information. And, we constructed the medical information integration database scheme that is consist medical information, patient, medical staff and medical image information according to medical information standards.y Finally, we show the usefulness of the dynamic access application service based on the smart devices for execution results of the proposed system according to patient contexts such as general and emergency situation. Especially, the proposed systems are providing effective medical information services with smart devices in emergency situation by dynamic access control methods. As results, we expect the proposed systems to be useful for u-hospital information systems and services.

• Journal of Chest Surgery
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• v.35 no.12
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• pp.876-881
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• 2002

Acute aortic dissection associated with high mortality rate has an extremely poor prognosis if early diagnosis and treatment are not received. Recently, with advanced computed tomography and echocardiography, diagnostic rate is higher and early operation is possible. Therefore preoperative medical therapy at ER(emergency room) lowered the mortality rate. This study was done to analyze the results with preoperative management at ER and operations, retrospectively. Material and Method: A series of 42 patients treated surgically for acute aortic dissections from 1991 to 2001 were included in this study. There were 18 males and 24 females. Mean age was 51.1 years. The admission course through emergency and outpatient department(OPD) was 34 and 8 respectively. Result: 26 patients underwent ascending aorta replacement-7 combined aortic valve replacements, 7 patients underwent descending aorta replacements and 9 patients received Bentall's operation. At emergency department, 20 patients received antihypertensive drugs and $\beta$-receptor blockers and 6 patients died. 22 patients did not receive antihypertensive and $\beta$-receptor block drugs and 10 patients died. There were 16(38%) overall deaths. Conclusion: Early diagnosis at ER or OPD is essential for acute aortic dissection, and it is important to select the most appropriate noninvasive interventions as possible. Therefore, preoperative drug therapy at ER is suggested according the patient conditions.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.58-65
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• 2019

Purpose: Alpha-amanitin induces potent oxidative stress and apoptosis, and may play a significant role in the pathogenesis of hepatotoxicity. This study examined the mechanisms of α-amanitin-induced apoptosis in vitro, and whether green tea extract (GTE) offers protection against hepatic damage caused by α-amanitin (AMA) induced apoptosis in vivo. Methods: The effects of GTE and SIL on the cell viability of cultured murine hepatocytes induced by AMA were evaluated using an MTT assay. Apoptosis was assessed by an analysis of DNA fragmentation and caspase-3. In the in vivo protocol, mice were divided into the following four groups: control group (0.9% saline injection), AMA group (α-amanitin 0.6 mg/kg), AMA+SIL group (α-amanitin and silibinin 50 mg/kg), and AMA+GTE group (α-amanitin and green tea extract 25 mg/kg). After 48 hours of treatment, the hepatic aminotransferase and the extent of hepatonecrosis of each subject was evaluated. Results: In the hepatocytes exposed to AMA and the tested antidotes, the cell viability was significantly lower than the AMA only group. An analysis of DNA fragmentation showed distinctive cleavage of hepatocyte nuclear DNA in the cells exposed to AMA. In addition, the AMA and GTE or SIL groups showed more relief of the cleavage of the nuclear DNA ladder. Similarly, values of caspase-3 in the AMA+GTE and AMA+SIL groups were significantly lower than in the AMA group. The serum AST and ALT levels were significantly higher in the AMA group than in the control and significantly lower in the AMA+GTE group. In addition, AMA+GTE induced a significant decrease in hepatonecrosis compared to the controls when a histologic grading scale was used. Conclusion: GTE is effective against AMA-induced hepatotoxicity with its apoptosis regulatory properties under in vitro and in vivo conditions.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.319-326
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• 2018

The safety interval to prevent collision between trains in a train control system is based on the braking distance according to the emergency braking of the train. The evaluation of the braking performance is based on the longitudinal train dynamics or the commissioning test in the test track, but since the conditions such as the weakening of the adhesion coefficient between the wheel and rail can not all be considered, these conventional methods are not sufficient to design of the train control systems. Therefore, in this study, the Monte Carlo Method (MCM) which can consider various environments is used to analyze braking performance and limitations. The braking model is based on the air braking used in the emergency braking and is modeled to take into account the braking pressure, efficiency, friction coefficient, adhesion condition, and vehicle mass distribution. It is confirmed that braking performance can be improved by controlling the quality of braking device. In addition, the change of the braking performance was confirmed according to the vehicle constituting the train. The results of this study are expected to be used as basic information for designing safety clearance for the train control systems and as a basis for improving the braking performance of railway vehicles.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.12-18
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• 2023

Objectives: Personal protective equipment (PPE) is an essential means for protecting workers against hazardous agents or risks that threaten their safety and health. Governmental organizations related to safety and health in the workplace regulate the PPE rules to protect workers and to minimize damage from hazardous agents. This study discussed current PPE rules overseen by the Korea Ministry of Environment and explores future perspectives on the matter. Methods: This study was based on a review of PPE regulations with which every stakeholder should comply in the workplace. Both South Korean regulations enforced by the Ministry of Employment and Labor and the Ministry of Environment and cases from other countries were reviewed. Results: Regulations related to the PPE required for handling chemical substances in the workplace are enforced by the Occupational Safety and Health Act, Enforcement Decree, Enforcement Rules, and Notification of Protective Equipment Certification under the Ministry of Employment and Labor. The Ministry of Environment also regulates the PPE standards for 97 substances requiring preparation for accidents and adjustment of work conditions, but a recent amendment (partially amended on September 30, 2022) loosened some unreasonable or excessive provisions. It requires workers simply to carry or otherwise keep PPE handy instead of wearing it for some tasks in which hazardous chemicals are not handled directly. Conclusions: It is important to regularly review provisions that need to be improved or supplemented to help all stakeholders. Considerations should be also made to build a reasonable regulatory system that can induce more mature safety management in each workplace.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.91-97
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• 2022

The purpose of this study was to analyze the measurements of blood pressure and time using manual and automatic blood pressure monitors in various road conditions to verify reliable blood pressure monitor in a moving ambulance. First, the manual blood pressure monitor palpation on unpaved roads showed a systolic pressure deviation of 5 mmHg. However, the automatic blood pressure monitor showed two measurement failures, one reading failure, and the measured systolic pressure deviation was 35 mmHg. The measurement time was 102 seconds faster on average than the automatic blood pressure monitor. Second, the palpation of the manual blood pressure monitor while going over speed bumps remained constant at 130 mmHg. However, the automatic blood pressure monitor had a systolic pressure deviation of 52 mmHg. The measurement time was 61 seconds faster on average than the automatic blood pressure monitor. Finally, the manual blood pressure monitor palpation on the sharp curve road showed a systolic pressure deviation of 5 mmHg. The automatic blood pressure monitor had one reading failure and the measured systolic pressure deviation was 21 mmHg. The measurement time showed that the manual blood pressure monitor was 101 seconds faster than the automatic blood pressure monitor. As a result, in a moving ambulance during an emergency, the manual blood pressure monitor showed high reliability because the blood pressure measurement was constant and the measurement time was short.

• Knowledge Management Research
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• v.24 no.4
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• pp.23-42
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• 2023

This study originated from recognition of importance of firefighters' decision-making in fire response, coupled with existing gap in research. By utilizing Q-methodology, the study aimed to categorize firefighters' subjectivity in fire response decision-making. Through this categorization, the study sought to highlight insights into the current technological and data limitations, as well as potential directions for future R&D in the field of firefighting. The findings of the study revealed that firefighters' subjectivity could be classified into three factors: "emphasis on direct information related to rescue," "emphasis on information related to the target property," and "emphasis on information related to command and coordination." The study theoretically confirmed that the subjectivity of firefighters' decision-making in fire response is partially influenced by their experiences and job. Additionally, the study's significance lay in its approach of collecting specific decision-making factors in fire response, moving beyond general theoretical models. Furthermore, from a policy perspective, the typification of decision-making factors contributed to connecting the identified data-based administrative needs from prior studies. Insights from the study emphasized the importance of leveraging on-site experience in Korea to aid decision-making, calling for the development of equipment and data collection methods that can rapidly and accurately assess on-site conditions.