• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.485-502
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• 2021

In order to evaluate the impact of ground subsidence and superstructures that are inevitably caused by tunnel excavation, a total of seven major influencing factors of surface subsidence and structural soundness reduction were set, and a Parameter Study using numerical analysis was conducted. Stability analysis was performed using scheme of Boscardin and Cording method and the maximum subsidence amount and the angular displacement, and correlation analysis was performed for each major influencing factor. In addition, it was applied that used the mutual behavior of the ground and the structure by parameter analysis in the site of the 𐩒𐩒𐩒 tunnel located in Hwaseong-si, Gyeonggi-do, and the applicability of the site was analyzed. As a result, the error was found to be 1.0%, and it could be used as a basic material for determining the appropriate tunnel route under various conditions when evaluating the stability of the structure according to tunnel excavating at the design stage.

• The Journal of the Acoustical Society of Korea
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• v.40 no.6
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• pp.537-545
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• 2021

Due to the accelerated development and transformation of coastal waters by humans, damage to marine mammals is a concern. To understand how coastal development may affect marine mammals, it is essential to determine their distribution characteristics. In this study, the appearance of finless porpoises was confirmed by passive acoustic monitoring around the Southwest offshore wind farm in July, 2020. Although there were no visual observation results of finless porpoises in the research area, the clicks measured in the offshore wind farm were verified by comparing with acoustic characteristics of the clicks measured in the area with a high detection rate. During the experimental period, clicks of finless porpoises were recorded for ten consecutive days, and Clicks per Porpoise Positive Minute (CPPM) was 40.7 clicks min-1, Porpoise Positive Minutes (PPM) was 9.7 %, Encounter duration and waiting time were 18.2 min and 94.9 min respectively. This study provides information on the appearance of them in the Southwest offshore wind farm and this result may help to monitor the impact of marine mammals from wind farm operation.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.755-768
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• 2021

Purpose: Due to the nature of heatwave research, where research is conducted for a variety of subjects and purposes, it is important to anticipate research trends and development directions in order to improve the quality of the research. Therefore, in order to provide basic data that can suggest the current status of heatwave research and the direction of future research, we tried to examine the trends of heatwave-related research. Method: Heatwave studies published in academic journals registered with the National Research Foundation of Korea from 2011 to 2020 were analyzed by classifying them according to the research period, the purpose of the study, the research subjects and the research method. Result: The main research results are as follows. First, as interest in heatwaves increases, the number of heatwave studies also increases. Second, the purpose of heatwave research is biased and needs to be studied from various perspectives. Third, although various research subjects were used, an even study was not conducted. Fourth, under the influence of the research purpose, the bias of the research method appeared together. Conclusion: The damage caused by the heat wave is persistent and has a widespread impact. In order to manage, prevent, and respond to such heat waves as disasters, equal research should be conducted in various fields.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.277-283
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• 2020

Objective: The sperm DNA fragmentation index (DFI) guides the clinician's choice of an appropriate assisted reproductive technology (ART) procedure. The DFI can be determined using commercially available methodologies, including sperm chromatin dispersion (SCD) kits and sperm chromatin structure assay (SCSA). Currently, when DFI is evaluated using SCD kits, the result is analyzed in reference to the SCSA-derived threshold for the choice of an ART procedure. In this study, we compared DFI values obtained using SCSA with those obtained using SCD and determined whether the difference affects the choice of ART procedure. Methods: We compared SCSA to two SCD kits, CANfrag (n=36) and Halosperm (n=31), to assess the DFI values obtained, the correlations between tests, the technical repeatability, and the impact of DFI on the choice of ART. Results: We obtained higher median DFI values using SCD kits than when using SCSA, and this difference was significant for the CANfrag kit (p<0.001). The SCD kits had significantly higher coefficients of variation than SCSA (p<0.001). In vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) would be chosen for a significantly higher proportion of patients if a decision were made based on DFI derived from SCD rather than DFI determined using SCSA (p=0.003). Conclusion: Our results indicate that SCD kit-specific thresholds should be established in order to avoid the unnecessary use of IVF/ICSI based on sperm DNA damage for the management of infertility. Appropriate measures should be taken to mitigate the increased variability inherent to the methods used in these tests.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.159-167
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• 2021

The increasingly severe environmental problems such as resource depletion and ecological damage, and consumers' concern for sustainable fashion, make the fashion industry chain develop towards green energy saving. The purpose of this study is to explore the attitude and consumption psychology of specific groups towards sustainable fashion consumption, as well as their specific views and attitudes towards recycled textiles or fabrics for re-manufacturing clothing. This paper attempts to understand how the characteristics of recycled clothing affect consumer. Based on the review of relevant literature, a series of determinants affecting consumer behavior is determined, and the characteristics of recycled products, such as expression value and social value, are determined. An online questionnaire was designed based on this conceptual framework, and 226 valid, complete answers were received. The results show that the emphasis on social value and environmental protection consciousness can effectively affect consumers' decision-making. These findings were helpful to the research of whole green environmental protection and ecological clothing recycling industry system, promote the sustainable development of the clothing industry.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1291-1307
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• 2021

State-sponsored cyberattacks have increased significantly and threaten national security in recent years. State-sponsored cyberattacks are often more sophisticated and destructive that attacks by individuals and private groups because of the concentration of manpower and resources. So major countries including the United States and the United Kingdom, as well as international organizations such as the EU and OECD, are recommending proportional response measures against cyberattacks. The Republic of Korea(ROK) is also trying to change its will to secure cyberattack deterrence and prepare active response through the 「National Cybersecurity Strategy 2019」. However, the ROK is not equipped with an adequate methodology to assess the severity of cyberattacks nor measures for proportional response to such attacks. In this paper, we propose a Cyber Attack Severity Assessment(CASA) methodology that can assess the scale and impact of damage to prepare external response threshold for cyberattacks at the government-level and to enable proportional responses when responding.

• Smart Structures and Systems
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• v.30 no.6
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• pp.687-701
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• 2022

Inevitable response loss under complex operational conditions significantly affects the integrity and quality of measured data, leading the structural health monitoring (SHM) ineffective. To remedy the impact of data loss, a common way is to transfer the recorded response of available measure point to where the data loss occurred by establishing the response mapping from measured data. However, the current research has yet addressed the structural condition changes afterward and response mapping learning from a small sample. So, this paper proposes a novel data driven structural response reconstruction method based on a sophisticated designed generating adversarial network (UAGAN). Advanced deep learning techniques including U-shaped dense blocks, self-attention and a customized loss function are specialized and embedded in UAGAN to improve the universal and representative features extraction and generalized responses mapping establishment. In numerical validation, UAGAN efficiently and accurately captures the distinguished features of structural response from only 40 training samples of the intact structure. Besides, the established response mapping is universal, which effectively reconstructs responses of the structure suffered up to 10% random stiffness reduction or structural damage. In the experimental validation, UAGAN is trained with ambient response and applied to reconstruct response measured under earthquake. The reconstruction losses of response in the time and frequency domains reached 16% and 17%, that is better than the previous research, demonstrating the leading performance of the sophisticated designed network. In addition, the identified modal parameters from reconstructed and the corresponding true responses are highly consistent indicates that the proposed UAGAN is very potential to be applied to practical civil engineering.

• Korean Journal of Head & Neck Oncology
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• v.38 no.2
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• pp.29-32
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• 2022

Lipoma is one of the most common benign soft tissue tumors. However, giant lipomas compressing and deforming the neurovascular structure rarely occur in the lateral neck. A 70-year-old man visited our outpatient clinic for treatment of a visible painless neck mass that had been identified 2 years prior. Neck magnetic resonance imaging revealed that a 10 × 9 × 4 cm fatty mass located between the sternocleidomastoid and sternohyoid muscles invaded the carotid sheath. Under general anesthesia, the mass was excised without damage to the adjacent neurovascular structures. Upon histopathological examination, the mass was identified as a lipoma. During the surgery, enlargement of the internal jugular vein was observed under the resected mass. However, on ultrasound examination, the function of the internal jugular vein was evaluated as good. No recurrence or neurological and vascular complications were reported during a 6-month follow-up after the surgery. As a giant lipoma located in the deep layer of the lateral neck can deform important cervical structures, its impact on the surrounding structures should be carefully assessed preoperatively to minimize the rate of possible complications.

• Nutrition Research and Practice
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• v.16 no.4
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• pp.464-475
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• 2022

BACKGROUND/OBJECTIVES: Increased levels of uremic toxins and decreased antioxidant capacity have a significant impact on the progression of chronic kidney disease (CKD). However, it remains unclear whether they interact with each other to mediate the damage of kidney function. The purpose of this study was to investigate whether uremic toxins (i.e., homocysteine and indoxyl sulfate [IS]), as well as glutathione-dependent antioxidant enzyme activities are dependently or independently associated with kidney function during different stages of CKD patients. SUBJECTS/METHODS: One hundred thirty-two patients diagnosed with CKD at stages 1 to 5 participated in this cross-sectional study. RESULTS: Patients who had reached an advanced CKD stage experienced an increase in plasma uremic toxin levels, along with decreased glutathione peroxidase (GSH-Px) activity. Plasma homocysteine, cysteine, and IS concentrations were all positively associated with each other, but negatively correlated to GSH-Px activity levels after adjusting for potential confounders in all CKD patients. Although plasma homocysteine, cysteine, IS, and GSH-Px levels were significantly associated with kidney function, only plasma IS levels still had a significant association with kidney function after these parameters were simultaneously adjusted. In addition, plasma IS could interact with GSH-Px activity to be associated with kidney function. CONCLUSIONS: IS plays a more dominant role than homocysteine and GSH-Px activity in relation to kidney function.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_2
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• pp.1119-1125
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• 2022

The depletion of resources and waste disposal caused by the continuous development of industry have emphasized the need to reduce consumption and production, recycle and reuse, and the importance of remanufacturing has increased in recent years. The spindle part of the aging planner miller, which is currently being remanufactured, is one of the factors that has the greatest impact on the performance of the machine tool. When designing the spindle part of the spindle shaft, there are considerations such as the configuration size bearing performance of the main shaft, but the diameter of the main shaft, the dangerous speed bearing, and the arrangement that affect the machining accuracy should be basically considered. As such, various studies have been conducted on the design of machine tool spindle spindles, but research on the reverse engineering of existing aging machine tool spindle spindles is poor. Reverse engineering is designing in the direction of improving performance by extracting specifications from already finished products, and first scanning the reverse engineered object through a 3D scanner, 3D modeling is performed based on the collected data, and then the process of deriving improvement plans by reverberating to improve performance by identifying wear and damage conditions is followed. Therefore, in this study, the purpose of this study is to provide data on reverse engineering by deriving improvement plans through optimal design for the bearing position of the aging planar Miller spindle spindle using central composite programming.