• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3336-3346
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• 2022

In general, a number of severe accident scenarios derived from Level 2 probabilistic safety assessment (PSA) are typically grouped into several categories to efficiently evaluate their potential impacts on the public with the assumption that scenarios within the same group have similar source term characteristics. To date, however, grouping by similar source terms has been completely reliant on qualitative methods such as logical trees or expert judgements. Recently, an exhaustive simulation approach has been developed to provide quantitative information on the source terms of a large number of severe accident scenarios. With this motivation, this paper proposes a machine learning-based categorization method based on exhaustive simulation for grouping scenarios with similar accident consequences. The proposed method employs clustering with an autoencoder for grouping unlabeled scenarios after dimensionality reductions and feature extractions from the source term data. To validate the suggested method, source term data for 658 severe accident scenarios were used. Results confirmed that the proposed method successfully characterized the severe accident scenarios with similar behavior more precisely than the conventional grouping method.

• Journal of Medicine and Life Science
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• v.19 no.2
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• pp.70-73
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• 2022

Here, we report a case of ultrasound-assisted subarachnoid block in a patient with severe kyphosis. A 69-year-old man was scheduled for metal removal from hip screws. He had a previous experience with subarachnoid block using the landmark-guided technique, but it was very difficult due to severe kyphosis. However, we could easily determine the correct needle insertion point using ultrasound imaging and performed a successful dural puncture on the first attempt. This case demonstrates the clinical usefulness of ultrasound imaging for subarachnoid blocks in patients with severe kyphosis.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.9-15
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• 2023

The Severe Disaster Punishment Act had recently been established in order to promote safety and health (OSH) management system for severe accident prevention. OSH management system is primarily designed based on risk assessments; however, companies in industries have been experiencing difficulties in hazard identification and selecting proper measures for risk assessments and accident prevention. This study intended to introduce an accident analysis method based on epidemiological model in finding hazard and preventive measures. The accident analysis method employed in this study was proposed by the U.S. Department of Energy. To demonstrate the effectiveness of the accident analysis method, this study applied it to two accident cases occurred in construction and manufacturing industries. The application process and results of this study can be utilized in improving OSH management system and preventing severe accidents.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2670-2677
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• 2023

In the nuclear safety studies, a new trend refers to the evaluation of uncertainties as a mandatory component of best-estimate safety analysis which is a modern and technically consistent approach being known as BEPU (Best Estimate Plus Uncertainty). The major objectives of this study consist in performing a study of uncertainties/sensitivities of the major analysis results for a generic CANDU 6 Nuclear Power Plant during Station Blackout (SBO) progression to understand and characterize the sources of uncertainties and their effects on the key figure-of-merits (FOMs) predictions in severe accidents (SA). The FOMs of interest are hydrogen mass generation and event timings such as the first fuel channel failure time, beginning of the core disassembly time, core collapse time and calandria vessel failure time. The outcomes of the study, will allow an improvement of capabilities and expertise to perform uncertainty and sensitivity analysis with severe accident codes for CANDU 6 Nuclear Power Plant.

• Tuberculosis and Respiratory Diseases
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• v.87 no.1
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• pp.12-21
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• 2024

The management of severe asthma presents a significant challenge in asthma treatment. Over the past few decades, remarkable progress has been made in developing new treatments for severe asthma, primarily in the form of biological agents. These advances have been made possible through a deeper understanding of the underlying pathogenesis of asthma. Most biological agents focus on targeting specific inflammatory pathways known as type 2 inflammation. However, recent developments have introduced a new agent targeting upstream alarmin signaling pathways. This opens up new possibilities, and it is anticipated that additional therapeutic agents targeting various pathways will be developed in the future. Despite this recent progress, the mainstay of asthma treatment has long been inhalers. As a result, the guidelines for the appropriate use of biological agents are not yet firmly established. In this review, we aim to emphasize the current state of biological therapy for severe asthma and provide insights into its future prospects.

• The Journal of Korean Medicine
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• v.44 no.4
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• pp.163-169
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• 2023

Methods: This study presents a comprehensive case study of an elderly male diagnosed with acute kidney injury (AKI) resulting from severe dehydration, supported by an extended follow-up with laboratory findings. Results: An 83-year-old male patient experienced severe diarrhea overnight, leading to hospitalization due to symptoms of dehydration and hypotension. His laboratory results displayed a typical AKI pattern, including a significant increase in creatinine levels (5.19 mg/dL) and the presence of hyperkalemia and hyponatremia. Following general treatments, including the administration of an herbal drug (Bulhwangeumjeonggi-san), the estimated glomerular filtration rate (eGFR) improved from 10 ml/min (Stage 5) to 34 ml/min (Stage 3) within five days when he was discharged. Although subsequent eGFR tests, conducted one and two months later as an outpatient, revealed an improvement of 42 ml/min, the patient still experienced mild chronic dysfunction as a consequence. Conclusion: This study presents a noteworthy case of acute kidney injury attributed to severe dehydration, emphasizing the importance of medical awareness regarding diarrhea-induced kidney function impairment, especially in the elderly population.

• Journal of Korean Academy of Nursing Administration
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• v.11 no.1
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• pp.33-44
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• 2005

Purpose: This study was aimed to estimate nursing cost for hemodialysis of tertiary hospitals using Resource Based Relative Value Scale(RVRBS). Method: First, we calculated nursing workload of the each hemodialysis-nursing behaviors compared with basic nursing behavior(check vital sign) for the most severe hemodialysis patients in general hospitals. Second, we measured each spent time according to each nursing behaviors. Third, we computed Resource Based Relative Value(RBRV) scores and nursing expenses of each 14 nursing behavior for hemodialysis. Finally, we estimated nursing cost of each hemodialysis-behavior for the most severe hemodialysis-patients in general hospitals. Result: The mean RBRV scores for each nursing behaviors were from 218.9 to 383.9 points. The highest RBRV socres were 383.9(Complication during hemodialysis). The Nursing behavior that spent the most time was "access the vascular( 31.7 minutes)". Nursing cost per hemodialysis for the patient with severe condition was estimated 63,455(won). Conclusion: Total average workload was 347.6 points and total spent time was 306.5 minutes for 14 hemodialysis nursing behaviors provided to severe patients. There were clear differences in nursing workload and cost according to patient's severity-mild, moderate and severe class.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.116-129
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• 2020

Resilience is defined as the intrinsic ability of a system to adjust its functioning prior to, during, or following changes and disturbances, so that it can sustain required operations or functions with the related systems under both expected and unexpected conditions. Resilience engineering is a relatively new paradigm for safety management that focuses on how to cope with complexity under pressure or disturbance to achieve successful functioning. This study aims to develop a quantitative resilience model for severe accident response organizations of nuclear power plants using the Analytic Hierarchy Process (AHP) method. First, we investigated severe accident response organizations based on a radiation emergency plan in the Korean case and developed a qualitative resilience model for the organizations with resilience-influencing factors, which have been identified in the author's previous studies. Then, a quantitative model for entire severe accident response organizations was developed by using the Analytic Hierarchy Process (AHP) method with a tool for System Dynamics. For applying the AHP method, several experts who are working on implementing, regulating or researching the severe accident response participated in collecting their expertise on the relative importance between all the possible relations in the model. Finally, a sensitivity analysis was carried out to discuss which factors have the most influenceable on resilience.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1537-1546
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• 2017

Many thermal-hydraulic tests have been conducted at the Korea Atomic Energy Research Institute for verification of the SMART (System-integrated Modular Advanced ReacTor) design, the standard design approval of which was issued by the Korean regulatory body. In this paper, the contributions of these tests to the standard design approval of SMART are discussed. First, an integral effect test facility named VISTA-ITL (Experimental Verification by Integral Simulation of Transients and Accidents-Integral Test Loop) has been utilized to assess the TASS/SMR-S (Transient and Set-point Simulation/Small and Medium) safety analysis code and confirm its conservatism, to support standard design approval, and to construct a database for the SMART design optimization. In addition, many separate effect tests have been performed. The reactor internal flow test has been conducted using the SCOP (SMART COre flow distribution and Pressure drop test) facility to evaluate the reactor internal flow and pressure distributions. An ECC (Emergency Core Coolant) performance test has been carried out using the SWAT (SMART ECC Water Asymmetric Two-phase choking test) facility to evaluate the safety injection performance and to validate the thermal-hydraulic model used in the safety analysis code. The Freon CHF (Critical Heat Flux) test has been performed using the FTHEL (Freon Thermal Hydraulic Experimental Loop) facility to construct a database from the $5{\times}5$ rod bundle Freon CHF tests and to evaluate the DNBR (Departure from Nucleate Boiling Ratio) model in the safety analysis and core design codes. These test results were used for standard design approval of SMART to verify its design bases, design tools, and analysis methodology.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.3
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• pp.121-140
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• 1991

Fifteen dental college students of Chosun University without the abnormal occlusion, the history and symptom of temporomandibular dysfunction(TMD), and who had all permanent teeth except third molar and the fifteen moderate group and the fifteen severe group classified according to Helkimo's dysfunction index among patients on the basis of the symptom of TMD were selected. The occlusal contact, occlusal force and occlusal interference in eccentric movement was studied and analyzed using T-Scan system. The result were as follows : 1. The TLR centering around midsagittal axis was located at $1.42{\pm}0.82mm$ in control group, $3.36{\pm}1.45mm$ in severe group, and as TMD was heavier, occlusal contact was located at the farther point from midsagittal axis. 2. The PLR from the first contact to the fifth contact centering around midsagittal axis was located at $1.73{\pm}1.78mm$ in control group, $3.36{\pm}1.41mm$ in moderate group, and $5.39{\pm}4.32mm$ in severe group, and as TMD was heavier, occlusal contact was located at the farther point from midsgittal axis. 3. The TFB, PFB, RFB and LFB of occlusal contact centering around incisal axis had no significant difference statistically among control group, moderate group, and severe group, and it was located at first molar. 4.The LF and RF was smaller in TMD group than in control group. 5. The LR moment of occlusal force centering around midsagittal axis was located at $178.51{\pm}139.81N.mm$ in control group, $466.25{\pm}296.47N.mm$ in moderate group, and $749.18{\pm}588.18N.mm$ in severe group. And as TMD was heavier, it was located at the farther point from midsagittal axis. 6. The RL and LL of occlusal force centering around incisal axis had not-significance statistically among control group, moderate group, and severe group, and it was at the first molar. 7. The number of occlusal interference of the eccentric movement was increased in the patients of TMD.