• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1125-1132
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• 2023

The importance of networks is gradually expanding in the battlefield environment. As time goes by, the types of tactical data links used in the Korean JTDLS are increasing, and the military's weapon systems equipped with tactical data link systems are increasing. Thorough quality verification is required to provide stable software to the wider battlefield. This study examines how to prepare an environment in which various simulation tests to verify the stability of the Korean JTDLS project can be conducted as diverse as possible using minimal physical space and Hardware resources. Through this, it is possible to improve the completeness of the project and secure the stability of the program, and it is intended to contribute to securing higher stability and reliability by securing maximum test capabilities in a limited test environment even in Linux based system project of a similar environment.

• Structural Monitoring and Maintenance
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• v.9 no.4
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• pp.305-321
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• 2022

Bridge structural health monitoring with the aim of continuously assessing structural safety and reliability represents a topic of major importance for worldwide infrastructure managers. In the last two decades, due to their potential economic and operational advantages, drive-by approaches experienced growing consideration from researcher and engineers. This work addresses two technical topics regarding indirect frequency estimation methods: bridge and vehicle dynamics overlapping, and bridge expansion joints impact. The experimental campaign was conducted on a mixed multi-span bridge located in Lombardy using a Ford Galaxy instrumented with a mesh of wireless accelerometers. The onboard time series were acquired for a number of 10 passages over the bridge,performed at a travelling speed of 30 km/h, with no limitations imposed to traffic. Exploiting an ad-hoc sensors positioning, pitch vehicle motion was compensated, allowing to estimate the first two bridge bending frequencies from PSD functions; moreover, the herein adopted approach proved to be insensitive to joints disturbance. Conclusively, a sensitivity study has been conducted to trace the relationship between estimation accuracy and number of trips considered in the analysis. Promising results were found, pointing out a clear positive correlation especially for the first bending frequency.

• Korean Journal of Radiology
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• v.25 no.8
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• pp.749-755
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• 2024

The recent surge in the incidence of small papillary thyroid cancers (PTCs) has been linked to the widespread use of ultrasonography, thereby prompting concerns regarding overdiagnosis. Active surveillance (AS) has emerged as a less invasive alternative management strategy for low-risk PTCs, especially for PTCs measuring ≤1 cm in maximal diameter. Recent studies report low disease progression rates of low-risk PTCs ≤1 cm under AS. Ongoing research is currently exploring the feasibility of AS for larger PTCs (<20 mm). AS protocols include meticulous ultrasound assessment, emphasis on standardized techniques, and a multidisciplinary approach; they involve monitoring the nodules for size, growth, potential extrathyroidal extension, proximity to the trachea and recurrent laryngeal nerve, and potential cervical nodal metastases. The criteria for progression, often defined as an increase in the maximum diameter of the PTC, warrant a review of precision and ongoing examinations. Challenges exist regarding the reliability of volume measurements for defining PTC disease progression. Although ultrasonography plays a pivotal role, challenges in assessing progression and minor extrathyroidal extension underscore the importance of a multidisciplinary approach in disease management. This comprehensive overview highlights the evolving landscape of AS for PTCs, emphasizing the need for standardized protocols, meticulous assessments, and ongoing research to inform decision-making.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.4
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• pp.315-326
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• 2024

In this study, the Delphi method and AHP (analytic hierarchy process) were used to evaluate tunnel collapse risk from a comprehensive and multifaceted perspective. Influence factors were established through literature reviews, previous studies, and brainstorming sessions with expert groups, resulting in the construction of five main classification systems. A panel of 21 experts was formed, and three rounds of Delphi surveys were conducted to prevent errors and biases in the expert judgment process, thereby enhancing reliability. Ultimately, 14 influence factors were identified through CVR (content validity ratio) and COV (coefficient of variation) analyses of the experts' responses. Subsequently, the AHP method was applied to assess the relative importance of each influence factor and calculate the final composite weights. The timing of support and reinforcement had the highest priority, followed by groundwater inflow, joint conditions, support pattern levels, and auxiliary methods. These findings help identify the key factors affecting tunnel collapse risk and provide a foundation for developing strategies to improve tunnel safety.

• Health Policy and Management
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• v.16 no.3
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• pp.86-106
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• 2006

The purpose of the study is 1) to explore clinic and hospital CEOs' satisfaction and expectation level on the affiliation with the larger size teaching hospitals, 2) to find the factors influencing the satisfaction and expectation level on the affiliation with the large hospitals. Data for analysis was collected to use self-administrative structured questionnaire on 335 CEOs of small or middle sized clinics and hospitals affiliated with large sized teaching hospitals located in Seoul and Kyung Ki Province. For the study, the researchers develop the constructs for questions on the satisfaction and the expectation of the affiliation, the attitude, knowledge on the affiliation, previous relationship of the affiliation, and selection guideline of the affiliation with exploratory factor analysis and reliability test. Through the confirmative factor analysis using AMOS 4, the researchers develop constructs based on exact relationship between constructs and questions. CEOs' expressive and unexpressive satisfaction level are 2.54 of 5 point(38.5 of 100) and 2.78 of 5 point(44.5 of 100), and the expressive and unexpressive expectation level are 2.77 of 5 point(44.3) and 3.16 of 5 point(54.0). These levels are relatively row for importance of affiliation. Expectation levels do not influence satisfaction levels. Attitude of affiliation influences expressive expectation and unexpressive satisfaction, reason for affiliation unexpressive satisfaction, and previous relationship to affiliated hospitals influence both of expressive and unexpressive satisfaction. The expressive expectation level and the expressive satisfaction level influence unexpressive expectation and unexpressive satisfaction, respectively. There is cognitive dissonance between expectation and satisfaction, therefore numbers of affiliation might be smaller or weaker in the future than present time. Many CEOs feel environmental press such as competition and the press of health insurance, but they might not think affiliation is best solution. Therefore, large hospitals try to give affiliated clinics and hospitals practical benefits to increase satisfaction and expectation levels, and they need to new affiliation form such as joint venture and joint ownership. The expectation and the satisfaction level was influenced by CEOs' gender, type of health service facilities, distances between the affiliated facility and the large mother hospital, and reason for affiliation.