• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.205-212
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• 2023

Among cardiac diseases, arrhythmias can lead to serious complications such as stroke, heart attack, and heart failure if left untreated, so continuous and accurate ECG monitoring is crucial for clinical care. However, the accurate interpretation of electrocardiogram (ECG) data is entirely dependent on medical doctors, which requires additional time and cost. Therefore, this paper proposes an arrhythmia recognition module for the purpose of developing a medical platform through the analysis of abnormal pulse waveforms based on Lifelogs. The proposed method is to convert ECG data into image format instead of time series data, apply visual pattern recognition technology, and then detect arrhythmia using CNN model. In order to validate the arrhythmia classification of the CNN model by image type conversion of ECG data proposed in this paper, the MIT-BIH arrhythmia dataset was used, and the result showed an accuracy of 97%.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.4
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• pp.763-780
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• 2024

As the domestic and international landscape undergoes rapid changes, the importance of implementing security measures in response to the growing threats that businesses face is increasing. In this context, the need for Security by Design (SbD), integrating security from the early design stages, is becoming more pronounced, with threat modeling recognized as a fundamental tool of SbD. Particularly, to save costs and time by detecting and resolving security issues early, the application of the Shift Left strategy requires the involvement of personnel with limited security expertise, such as software developers, in threat modeling. Although various automated threat modeling tools have been released, their lack of user-friendliness for personnel lacking security expertise poses challenges in conducting threat modeling effectively. To address this, we conducted an analysis of research related to threat modeling tools and derived usability evaluation criteria based on the GQM(Goal-Question-Metric) approach. An expert survey was conducted to validate both the validity and objectivity of the derived criteria. We performed usability evaluations of three threat modeling tools (MS TMT, SPARTA, PyTM), and the evaluation results led to the conclusion that MS TMT exhibited superior usability compared to other tools. This study aims to contribute to the creation of an environment where personnel with limited security expertise can effectively conduct threat modeling by proposing usability evaluation criteria.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.4
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• pp.308-312
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• 2022

Backgrounds/Aims: Although body surface area (BSA)-based standard liver volume (SLV) formulae have been used for living donor liver transplantation and hepatic resection, hemi-liver volume (HLV) is needed more frequently. HLV can be assessed using right or left portal vein diameter (RPVD or LPVD). The aim of this study was to validate the reliability of using portal vein diameter ratio (PVDR) for assessing HLV in living liver donors. Methods: This study included 92 living liver donors (59 males and 33 females) who underwent surgery between January 2020 and December 2020. Computed tomography (CT) images were used for measurements. Results: Mean age of donors was 35.5 ± 7.2 years. CT volumetry-measured total liver volume (TLV), right HLV, left HLV, and percentage of right HLV in TLV were 1,442.9 ± 314.2 mL, 931.5 ± 206.4 mL, 551.4 ± 126.5 mL, and 64.6% ± 3.6%, respectively. RPVD, LPVD, and main portal vein diameter were 12.2 ± 1.5 mm, 10.0 ± 1.3 mm, and 15.3 ± 1.7 mm, respectively (corresponding square values: 149.9 ± 36.9 mm², 101.5 ± 25.2 mm², and 237.2 ± 52.2 mm², respectively). The sum of RPVD2 and LPVD2 was 251.1 ± 56.9 mm². BSA-based SLV was 1,279.5 ± 188.7 mL (error rate: 9.1% ± 14.4%). SLV formula- and PVDR-based right HLV was 760.0 ± 130.7 mL (error rate: 16.2% ± 13.3%). Conclusions: Combining BSA-based SLV and PVDR appears to be a simple method to predict right or left HLV in living donors or split liver transplantation.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.383-388
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• 2024

This study conducted voluntary focus group user observations to empirically validate the efficacy of the self-developed psychological support mobile application, "Mindful Now". The app is structured as an interactive game format, enabling individuals to activate self-awareness of mindfulness states anytime, anywhere. It consists of a 3-step process of sensory/emotional/consciousness awareness, facilitating the expression of non-judgmental awareness. To demonstrate the effectiveness of this mindful activation in enhancing psychological well-being such as happiness and stress reduction, voluntary mindfulness mobile app usage was tracked among 49 university students. The results revealed significant improvements, with a 14.4% increase in SWLS happiness index and a 17.1% decrease in PSS-10 stress levels among 12 users who used the app continuously for over 60 days to practice mindfulness awareness. Particularly, higher app engagement was observed among students who initially reported relatively lower indices before using the app. The utilization of mobile apps that promote mindful activation aligns with various therapeutic paradigms based on mindfulness and meditation, contributing to advancements in digital therapeutic interventions for psychological support.

• The Korean journal of internal medicine
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• v.39 no.3
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• pp.458-468
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• 2024

Background/Aims: The SAMe-TT₂R₂ score is used for assessing anticoagulation control (AC) quality with warfarin. However, it is hard to apply SAMe-TT₂R₂ score in Asian patients with atrial fibrillation (AF), because it has not been proven in those populations. This study aimed to validate the SAMe-TT₂R₂ score in Asian patients with AF and suggest a modified SAMe-TT₂R₂ score for this population. Methods: We analyzed 710 Korean patients with AF who were using warfarin. The AC quality was assessed as the mean time in therapeutic range (TTR). Each component of SAMe-TT₂R₂ score was evaluated for the relationship with AC. Further clinical factors that predict AC were analyzed. Identified factors were re-assorted and constructed as SA₂Me-TTR scoring system. Results: Of the components of the SAMe-TT₂R₂ score, female, age, and rhythm control were associated with AC. Heart failure and renal insufficiency were newly identified factors associated with AC. The modified SA₂Me-TTR score was reconstructed with the relevant risk factors (S, female gender, 1 point; A, age < 60 yr, 2 points; Me, medical history of heart failure, 1 point; T, treatment for rhythm control, 1 point; T, history of stroke or transient ischemic attack, 1 point; R, renal insufficiency, 1 point). The modified SA₂Me-TTR score demonstrated an excellent relationship with the grading of AC. The modified SA₂Me-TTR score ≤ 1 identified patients with good AC (hazard ratio 2.46, 95% CI 1.75-3.47). Conclusions: The modified SA₂Me-TTR score was useful for guiding oral anticoagulants selection in Asian patients with AF.

• Korean Journal of Radiology
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• v.25 no.7
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• pp.644-655
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• 2024

Objective: To develop and validate a preoperative risk score incorporating carbohydrate antigen (CA) 19-9, CT, and fluorine18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT variables to predict recurrence-free survival (RFS) after upfront surgery in patients with resectable pancreatic ductal adenocarcinoma (PDAC). Materials and Methods: Patients with resectable PDAC who underwent upfront surgery between 2014 and 2017 (development set) or between 2018 and 2019 (test set) were retrospectively evaluated. In the development set, a risk-scoring system was developed using the multivariable Cox proportional hazards model, including variables associated with RFS. In the test set, the performance of the risk score was evaluated using the Harrell C-index and compared with that of the postoperative pathological tumor stage. Results: A total of 529 patients, including 335 (198 male; mean age ± standard deviation, 64 ± 9 years) and 194 (103 male; mean age, 66 ± 9 years) patients in the development and test sets, respectively, were evaluated. The risk score included five variables predicting RFS: tumor size (hazard ratio [HR], 1.29 per 1 cm increment; P < 0.001), maximal standardized uptake values of tumor ≥ 5.2 (HR, 1.29; P = 0.06), suspicious regional lymph nodes (HR, 1.43; P = 0.02), possible distant metastasis on ¹⁸F-FDG PET/CT (HR, 2.32; P = 0.03), and CA 19-9 (HR, 1.02 per 100 U/mL increment; P = 0.002). In the test set, the risk score showed good performance in predicting RFS (C-index, 0.61), similar to that of the pathologic tumor stage (C-index, 0.64; P = 0.17). Conclusion: The proposed risk score based on preoperative CA 19-9, CT, and ¹⁸F-FDG PET/CT variables may have clinical utility in selecting high-risk patients with resectable PDAC.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.4
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• pp.123-138
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• 2024

This study aimed to examine the effects of leisure activities on leisure satisfaction and job satisfaction among airline cabin crew, as well as the mediating effect of leisure satisfaction. The context for this research was the sudden increase in air travel demand in 2022 following the COVID-19 economic recovery, which led to cabin crew members experiencing severe stress and fatigue due to excessive scheduling. To achieve this research objective, a self-administered online survey was conducted with 251 cabin crew members from domestic and international airlines, resulting in a total of 224 valid leisure satisfaction and job satisfaction, as well as the mediating effect of leisure satisfaction on the relationship between leisure activity types and job satisfaction. The hypothesis testing results revealed that all types of leisure activities, including family-oriented, friend-oriented, and work-related activities, had a significant positive effect on leisure satisfaction. Family-oriented and work-related leisure activities had a significant positive effect on job satisfaction, and leisure satisfaction had a significant positive effect on job satisfaction. Additionally, the mediation analysis confirmed that leisure satisfaction partially mediated the relationship between family-oriented and work-related leisure activities and job satisfaction, while it fully mediated the relationship between friend-oriented leisure activities and job satisfaction. Therefore, the study offers academic implications based on these findings and proposes strategies for utilizing various types of leisure activities to enhance leisure satisfaction and job satisfaction among airline cabin crew. It also suggests that future research should further validate these findings through methods such as the Delphi technique or Analytic Hierarchy Process (AHP) analysis to assess the importance and prioritization of these factors among relevant industry stakeholders.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.163-178
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• 2024

Purpose : This study aimed to evaluate the effectiveness of an integrative medical service model applied to breast cancer patients and their caregivers, exploring its feasibility and challenges within the context of South Korean healthcare system. Methods : A case study approach was chosen to assess the integrative medical service model's efficacy, involving one breast cancer patient and her primary caregiver from W University Hospital. The patient had completed reconstructive surgery and chemotherapy and was undergoing radiotherapy. The model included standard treatments alongside psychological counseling, aromatherapy, axillary rehabilitation exercise, make-up program, art therapy, laughter therapy, horticultural therapy, and yoga programs, and meditation programs delivered over eight weeks. Quantitative and qualitative data were collected through surveys, psychological tests, and feedback assessments. Results : The integrative medical service model demonstrated notable improvements in the quality of life for both breast cancer patients and their caregivers. Participants reported enhanced emotional well-being, reduced stress levels, and improved coping mechanisms throughout the treatment journey. Qualitative feedback highlighted the positive impact of holistic interventions in alleviating psychological distress and fostering resilience. Quantitative data corroborated these findings, showing statistically significant improvements in various psychosocial parameters assessed. Conclusions : Our findings underscore the benefits of integrative medical service model with standard medical treatments in the care of breast cancer patients and their caregivers. The holistic approach not only addresses physical symptoms but also enhances overall well-being and quality of life. However, the implementation of such models faces challenges within the South Korean healthcare system, including fragmented service networks and financial constraints. Addressing these structural barriers is crucial for the widespread adoption and sustainability of integrative care models in oncology practice. Future research should focus on larger-scale studies to further validate these findings and inform policy decisions aimed at optimizing cancer care delivery.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.4
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• pp.747-761
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• 2024

Recently, modern vehicles have been controlled by Electronic Control Units (ECUs), by which the safety and convenience of drivers are highly improved. It is known that a luxury vehicle has more than 100 ECUs to electronically control its function. However, the modern vehicles are getting targeted by cyber attacks because of this computer-based automotive system. To address the cyber attacks, automotive manufacturers have been developing some methods for securing their vehicles, such as automotive Intrusion Detection System (IDS). This development is only allowed to the automotive manufacturers because they have databases for their in-vehicle network (i.e., DBC Format File) which are highly confidential. This confidentiality poses a significant challenge to external researchers who attempt to conduct automotive security researches. To handle this restricted information, in this paper, we propose a method to partially understand the DBC Format File by analyzing in-vehicle network traffics. Our method is designed to analyze Controller Area Network (CAN) traffics so that checksum signals are identified in CAN Frame Data Field. Also, our method creates a Lookup Set by which a checksum signal is correctly estimated for a given message. We validate our method with the publicly accessible dataset as well as one from a real vehicle.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.180-187
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• 2009

The objective of this research is to verify the code-specified girder distribution factors (GDF) for continuous steel girder bridges by field testing. Previous analytical study revealed that current GDF's specified in AASHTO Standard and AASHTO LRFD, developed for the simple span bridges are conservative even for the continuous bridges. In this study, field tests were performed for three continuous steel girder bridges to validate the GDF's specified in the AASHTO codes. The results show that the code values are conservative when compared with field tests, and in some cases, too conservative. Also, strains measured from the field test are, in most cases, smaller than those expected from the analytical results. However, when the GDF's from measured strains are compared with GDF's from analysis, it is found that the analysis results are not conservative, and in some instance, the analytical results underestimate the actual GDF's, which can lead to a groundless notion of safety. In one case, test results showed that the code GDF's specified in AASHTO LRFD is too permissive. As a result, it is found that GDF's specified in AASHTO LRFD should be used with careful reservation.