• Korean Journal of Radiology
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• v.22 no.6
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• pp.983-993
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• 2021

Objective: To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. Materials and Methods: Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signed-rank test were performed to compare the objective measurements and the subjective image quality scores, respectively. Results: With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p < 0.001) and a similar noise level to model-based iterative reconstruction (19.6 ± 2.6 HU, p > 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. Conclusion: The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.351-368
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• 2024

Purpose: In general, traffic accidents occur sporadically, so there are various limitations in terms of time and cost when conducting field investigations to prepare prevention and prevention measures. In particular, with the transition to a non-face-to-face society after the COVID-19, there is a greater need to prepare a replacement for field surveys. Therefore, in this study, Roadview provided by various websites was used as an alternative to field surveys in Sasang-gu, Busan City. The possibility was evaluated. Method: The research method was to extract vulnerable points for traffic accidents that occurred between 2016 and 22 and analyze road views based on the field survey evaluation items provided in the Traffic Safety Diagnosis Guidelines. Result: The main result was that Sasang-gu was most vulnerable to accidents involving elderly pedestrians at Sasang-ro, Daedong-ro, and Hakjang-ro. As a result of a detailed analysis of vulnerable points through Road View, Sasang-ro needed control of commercial vehicles and protection of the transportation vulnerable in the market commercial area. Daedong-ro was vulnerable to illegal on-street parking and slope merging sections, and Hakjang-ro was vulnerable to roads that were prone to speeding. When evaluating the possibility of replacing Roadview's field survey based on the results of this analysis, Roadview was able to effectively evaluate most items, such as separation of sidewalks and the location and spacing of safety facilities. However, there were limitations in items such as actual measurement performance. Conclusion: In other words, the road view can replace most field surveys, and the actual measurement evaluation items can be judged to be useful as auxiliary data, resulting in time and cost savings and high efficiency.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.157-166
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• 2024

The Army TIGER System, which is being deployed to implement a future combat system, is expected to bring innovative changes to the army's combat methods and comabt execution capability such as mobility, networking and intelligence. To this end, the Army will introduce various systems using drones, robots, unmanned vehicles, AI(Artificial Intelligence), etc. and utilize them in combat. The use of various unmanned vehicles and AI is expected to result in the introduction of equipment with new technologies into the army and an increase in various types of transmitted information, i.e. data. However, currently in the military, there is an acceleration in research and combat experimentations on warfigthing options using Army TIGER forces system for specific functions. On the other hand, the current reality is that research on cyber threats measures targeting information systems related to the increasing number of unmanned systems, data production, and transmission from unmanned systems, as well as the establishment of cloud centers and AI command and control center driven by the new force systems, is not being pursued. Accordingly this paper analyzes the structure and characteristics of the Army TIGER force integration system and makes suggestions for necessity of building, available cyber defense solutions and Army TIGER integrated cyber protections system that can respond to cyber threats in the future.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.367-375
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• 2023

This study developed a new distance metric for vessel trajectories, applicable to marine traffic control services in the Korean coastal waters. The proposed metric is designed through the weighted summation of the traditional Hausdorff distance, which measures the similarity between spatiotemporal data and incorporates the differences in the average Speed Over Ground (SOG) and the variance in Course Over Ground (COG) between two trajectories. To validate the effectiveness of this new metric, a comparative analysis was conducted using the actual Automatic Identification System (AIS) trajectory data, in conjunction with an agglomerative clustering algorithm. Data visualizations were used to confirm that the results of trajectory clustering, with the new metric, reflect geographical distances and the distribution of vessel behavioral characteristics more accurately, than conventional metrics such as the Hausdorff distance and Dynamic Time Warping distance. Quantitatively, based on the Davies-Bouldin index, the clustering results were found to be superior or comparable and demonstrated exceptional efficiency in computational distance calculation.

• Science of Emotion and Sensibility
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• v.26 no.4
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• pp.15-28
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• 2023

Considering the necessity for individuals to check and manage their wellness to promote happiness, this study conducted preliminary research on the effect of wellness enhancement of the self-life coaching app. Thirty-six participants were randomly assigned to experimental groups 1 and 2 and a control group, respectively. In particular, the experimental groups were asked to perform self-life coaching for 4 weeks using a research app. Weekly feedback was provided to experimental group 1, but not to experimental group 2. The wellness index for workers (WIW) and the Korean wellness scale (KWS) were used as dependent variables. The analysis results of interaction effects between pre-, post-, and follow-up time points and groups reveal no statistically significant effects in both dependent variables, but the tendency of the effects was confirmed. Moreover, no difference was determined in terms of the presence or absence of weekly feedback in the experimental treatment effect. As a result of repeated measures variance analysis on KWS measured at five times, the wellness enhancement effect over time was statistically significant. Meanwhile, the polynomial trend analysis result confirmed the linear effect of the experimental treatment on wellness. The participation opinion survey also revealed that 84.2% of the participants perceived the activity to be helpful, and 78.9% responded that they would use it once every 1 or 2 weeks if the app is commercially available. This study is meaningful in that it suggests a methodology for utilizing the self-life coaching app so that anyone can use it to promote their wellness and partially confirms the effectiveness of this method.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.7-11
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• 2024

Pump car is an equipment that transports concrete products as needed to the place where they are poured. In order to pour a large amount of concrete in a short period of time, using a pump car is the most efficient in terms of economic efficiency and quality control. However, recently, many casualties have occurred due to boom damage during concrete pouring, so this study suggests that improvements are needed in the equipment manufacturing stage, inspection standards for old equipment, and equipment rental system. The reason is that, as a result of the finite element analysis of the pump car, the significant stress acting at the second stage of the boom and the maximum stress at the top of the boom were found to be 895.39 MPa, and M.S. Since it was evaluated the lowest at 0.04, the need for reinforcement was recognized. And it was confirmed that the 2nd stage boom was the most stressful and vulnerable part of the 1st to 5th stage booms. Therefore, it is necessary to increase the thickness and rigidity of members at the design and manufacturing stage, and to reinforce the steel plates of currently used equipment. In addition, it is urgent to establish a system that makes non-destructive testing mandatory for all general construction machinery and holds inspection agencies responsible for missing boom defects during non-destructive testing and regular inspections.

• Industry Promotion Research
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• v.9 no.2
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• pp.95-102
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• 2024

This study aims to compare the role of the public sector in the U.S. and Korean medical security systems and study response measures in the social risk situation of the COVID-19 virus. The COVID-19 pandemic was a typical case of a 'disaster' that spread across the world across borders in a short period of time and caused serious social welfare losses by increasing the annual number of deaths by approximately 4% in 2020. Threats to health security, such as changes in social order, unpredictable endings, prolonged control of daily life, and deepening inequality, affected the economy, politics, and environment as a whole, and people had to experience anxiety and confusion due to mental and physical stress. Furthermore, developed countries failed to provide help to low-income countries in the face of global disasters. In this situation, the country's disaster management capacity to minimize harm and secure resilience, especially disaster response capacity in the health and medical field, is inevitably very important. Therefore, this study compares how the health insurance system, which is a system to guarantee citizens' right to life, differs from the United States, a liberal health care country, and raises the need to strengthen the role of the public sector.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.73-82
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• 2024

In 2017, the United Nations reported that the population aged 60 and above was increasing more rapidly than all younger age groups worldwide, projecting that by 2050, the population aged 60 and above would constitute at least 25% of the global population, excluding Africa. The world is experiencing a decline in the rate of increase in the working-age population due to global aging, and the younger generation tends to avoid difficult and challenging occupations. Although theoretically, AI equipped with artificial intelligence can replace humans in all fields, in the realm of practical information security, human judgment and expertise are absolutely essential, especially in ethical considerations. Therefore, this paper proposes a method to retrain and reintegrate IT professionals aged 50 and above who are retiring or seeking career transitions, aiming to bring them back into the industry. For this research, surveys were conducted with 21 government/public agencies representing demand and 9 security monitoring companies representing supply. Survey results indicated that both demand (90%) and supply (78%) unanimously agreed on the absolute necessity of such measures. If the results of this research are applied in the field, it could lead to the strategic development of senior information security professionals, laying the foundation for a new market in the Korean information security industry amid the era of low birth rates and longevity.

• Journal of the Korean GEO-environmental Society
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• v.25 no.6
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• pp.19-24
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• 2024

Urban densification has necessitated the development of subterranean spaces such as subway networks and underground tunnels to facilitate the dispersal and movement of populations. Development of these underground spaces requires excavation from the ground surface, which can induce groundwater flow and potentially lead to ground subsidence and sinkholes, damaging structures. To mitigate these risks, it is essential to model groundwater flow prior to construction, analyze its characteristics, and predict potential groundwater discharge during excavation. In this study, we collected meteorological, topographical, and soil conditions data for the city of ○○, where tunnel construction was planned. Using the Visual MODFLOW program, we modeled the groundwater flow. Excavation sections were set as drainage points to monitor groundwater discharge during the excavation process, and the effectiveness of seepage control measures was assessed. The model was validated by comparing measured groundwater levels with those predicted by the model, yielding a coefficient of determination of 0.87. Our findings indicate that groundwater discharge is most significant at the beginning of the excavation. Additionally, the presence of seepage barriers was found to reduce groundwater discharge by approximately 59%.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1259-1267
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• 2023

The purpose of this study was to investigate the effects of a acute ankle mobility exercise (AE) program on the range of motion and pain levels associated with chronic ankle instability (CAI). Twenty adult women with an average score of 24 or less on both sides in the ankle instability questionnaire were selected and divided into two groups: the Ankle Mobility Exercise Program group (AE, n=10) and the control group (CON, n=10). The AE treatment involved a one-time, 20-minute exercise session for each ankle, conducted separately on the left and right ankles, to examine the response to a acute exercise. Measures of ankle instability, pain, and ankle range of motion were evaluated before and after the treatment. In the AE group, which underwent the AE program, a significant decrease in pain was observed post-AE compared to pre-AE (p<.01). In addition, an increase in dorsiflexion was observed in the AE group post-AE compared to pre-AE following the AE program(p<.05). These results suggest that a acute AE program can effectively alleviate some aspects of ankle instability by improving ankle pain and range of motion in adult women with chronic ankle instability (CAI).