• Smart Structures and Systems
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• v.31 no.4
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• pp.365-381
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• 2023

The existing vision-based techniques for inspection and condition assessment of civil infrastructure are mostly manual and consequently time-consuming, expensive, subjective, and risky. As a viable alternative, researchers in the past resorted to deep learning-based autonomous damage detection algorithms for expedited post-disaster reconnaissance of structures. Although a number of automatic damage detection algorithms have been proposed, the scarcity of labeled training data remains a major concern. To address this issue, this study proposed a semi-supervised learning (SSL) framework based on consistency regularization and cross-supervision. Image data from post-earthquake reconnaissance, that contains cracks, spalling, and exposed rebars are used to evaluate the proposed solution. Experiments are carried out under different data partition protocols, and it is shown that the proposed SSL method can make use of unlabeled images to enhance the segmentation performance when limited amount of ground truth labels are provided. This study also proposes DeepLab-AASPP and modified versions of U-Net++ based on channel-wise attention mechanism to better segment the components and damage areas from images of reinforced concrete buildings. The channel-wise attention mechanism can effectively improve the performance of the network by dynamically scaling the feature maps so that the networks can focus on more informative feature maps in the concatenation layer. The proposed DeepLab-AASPP achieves the best performance on component segmentation and damage state segmentation tasks with mIoU scores of 0.9850 and 0.7032, respectively. For crack, spalling, and rebar segmentation tasks, modified U-Net++ obtains the best performance with Igou scores (excluding the background pixels) of 0.5449, 0.9375, and 0.5018, respectively. The proposed architectures win the second place in IC-SHM2021 competition in all five tasks of Project 2.

• International Journal of High-Rise Buildings
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• v.12 no.1
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• pp.93-105
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• 2023

Seismic isolation and vibration control techniques have been developed and put into practical use by challenging researchers and engineers worldwide since the latter half of the 20th century, and after more than 40 years, they are now used in thousands of buildings, private residences, highways in many seismic areas in the world. Seismic isolation and vibration control structures can keep the structures undamaged even in a major earthquake and realize continuous occupancy. This performance has come to be recognized not only by engineers but also by ordinary people, becoming indispensable for the formation of a resilient society. However, the dynamic characteristics of seismically isolated bearings, the key elements, are highly dependent on the size effect and rate-of-loading, especially under extreme loading conditions. Therefore, confirming the actual properties and performance of these bearings with full-scale specimens under prescribed dynamic loading protocols is essential. The number of testing facilities with such capacity is still limited and even though the existing labs in the US, China, Taiwan, Italy, etc. are conducting these tests, their dynamic loading test setups are subjected to friction generated by the large vertical loads and inertial force of the heavy table which affect the accuracy of measured forces. To solve this problem, the authors have proposed a direct reaction force measuring system that can eliminate the effects of friction and inertia forces, and a seismic isolation testing facility with the proposed system (E-isolation) will be completed on March 2023 in Japan. This test facility is designed to conduct not only dynamic loading tests of seismic isolation bearings and dampers but also to perform hybrid simulations of seismically isolated structures. In this paper, design details and the realization of this system into an actual dynamic testing facility are presented and the outcomes are discussed.

• The Korean Journal of Pain
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• v.36 no.4
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• pp.441-449
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• 2023

Background: Hypertonic saline is used for treating chronic pain; however, clinical studies that aid in optimizing therapeutic protocols are lacking. We aimed to determine the concentration of intrathecally injected hypertonic saline at which the effect reaches its peak as well as the underlying γ-aminobutyric acid (GABA) receptor-related antinociceptive mechanism. Methods: Spinal nerve ligation (SNL; left L5 and L6) was performed to induce neuropathic pain in rats weighing 250-300 g. Experiment 1: one week after implanting the intrathecal catheter, 60 rats were assigned randomly to intrathecal injection with 0.45%, 0.9%, 2.5%, 5%, 10%, and 20% NaCl, followed by behavioral testing at baseline and after 30 minutes, 2 hours, 1 day, and 1 week to determine the minimal concentration which produced maximal analgesia. Experiment 2: after determining the optimal intrathecal hypertonic saline concentration, 60 rats were randomly divided into four groups: Sham, hypertonic saline without pretreatment, and hypertonic saline after pretreatment with one of two GABA receptor antagonists (GABA_A [bicuculline], or GABA_B [phaclofen]). Behavioral tests were performed at weeks 1 and 3 following each treatment. Results: Hypertonic saline at concentrations greater than 5% alleviated SNL-induced mechanical allodynia and had a significant therapeutic effect, while showing a partial time- and dose-dependent antinociceptive effect on thermal and cold hyperalgesia. However, pretreatment with GABA receptor antagonists inhibited the antinociceptive effect of 5% NaCl. Conclusions: This study indicates that the optimal concentration of hypertonic saline for controlling mechanical allodynia in neuropathic pain is 5%, and that its analgesic effect is related to GABA_A and GABA_B receptors.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.51-58
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• 2010

SIP is a flexible and extensible call setup protocol that may be combined with other protocols used in the Internet to make various services like voice communication. Voice communication can be classified into normal calls used for communication between common users and emergency calls for 112, 119 and other services through public safety networks. It is required to research to process effectively these normal calls and emergency calls through public networks such as the Internet. In this paper, we propose a bypass scheme for emergency calls by giving priority to INVITE messages for them and processing them with priority in the SIP proxy queue. We perform simulation studies using the network simulator ns-2 for the performance evaluation. Simulation results show that the proposed scheme processes emergency calls faster than normal calls and thus it is expected to make a special purpose network like the national disaster network efficiently by using the existing Internet.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.609-616
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• 2023

In a wireless network environment, since sensors are not always connected to power, the life of a battery, which is an energy source supplied to sensors, is limited. Therefore, various studies have been conducted to extend the network life, and a layer-based routing protocol, LEACH(: Low-energy Adaptive Clustering Hierarchy), has emerged for efficient energy use. However, the LEACH protocol, which transmits fused data directly to the sink node, has a limitation in that it consumes as much energy as the square of the transmission distance when transmitting data. To improve these limitations, this paper proposes an algorithm that can minimize the transmission distance with multi-hop transmission where cluster heads are chained between cluster heads through relative distance calculation from sink nodes in every round.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.406-409
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• 2022

In recent years, the developments in technologies, such as AI systems, Blockchain, VR/AR, 3D printing, robotics, and nanotechnology, are reshaping the future of healthcare right before our eyes. And also, healthcare has seen a paradigm shift towards prevention-oriented medicine, with a focus on consumers requirements. The spread of infectious diseases such as Covid-19 have altered the definition of healthcare and treatment facilities, necessitating immediate action to redesign hospitals' physical environments, adapt communication models to address social distancing requirements, implement virtual health solutions, and establish new clinical protocols. Hospitals, which have traditionally served as the hub of healthcare systems, are pursuing or being forced to reestablish themselves against this landscape. Rather than only treating ailments, future healthcare is predicted to focus on wellness and prevention. In personalized care, long-term prevention strategies, remote monitoring, early diagnosis, and detection are critical. Given the growing interest in smart healthcare defined by these modern technologies, this study looked into the definitions and service kinds of smart healthcare. The background and technical aspects of smart hospitals were also explored through a literature review.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.595-605
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• 2023

With the escalating prevalence of modular construction projects, there is a concurrent surge in scholarly and industrial intrigue in this domain, leading to a broadened spectrum of its applications. Modular construction, inherently facilitated by controlled factory settings, boasts the capability to consistently deliver edifices of superior quality. To optimize this advantage, the judicious integration of quality assurance methodologies during the site-specific phases of lifting and assembly is non-negotiable. This research embarked on a survey directed at project stakeholders, aiming to gauge the perceived significance and efficaciousness of prevailing quality preservation and oversight protocols during the aforementioned site stages, subsequently employing the Importance-Performance Analysis(IPA) for data interpretation. The findings elucidated that, while a majority of quality assurance procedures were adeptly executed, perceptual disparities existed among stakeholders regarding certain aspects, prompting recommendations for enhancement. This investigative endeavor lays a foundation, aiding future studies in amplifying the quality assurance cognizance among professionals during modular construction's site-assembly phase.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.639-650
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• 2023

In this research endeavor, we engaged with 70 construction safety specialists from established construction firms through surveys and interviews. The primary aim was to dissect and understand the weight and ramifications of specific cost items within the Occupational Safety and Health Management Funds(OSHMF) and Safety Management Expenses(SME). From our analysis, salient insights emerged. Within the realm of OSHMF, the cost items associated with safety facilities and the remunerations of safety managers were identified as paramount. It was observed that there are marked variations in the perceived significance and repercussions associated with diverse cost items of OSHMF. In stark contrast, when assessing the SME, the nuances in perceived weight and consequences of individual cost items were relatively muted, suggesting a more uniform viewpoint among the experts. Furthermore, our research probed the interrelationship between the significance and repercussions within OSHMF and SME domains. Notably, OSHMF manifested a positive linear relationship, suggesting that cost items of higher importance invariably had a more pronounced effect. On the other hand, the SME showcased a more subtle association, hinting at intricate underlying dynamics. The outcomes of this investigation are poised to offer instrumental guidance for enhancing safety protocols and diminishing accident occurrences in domestic construction undertakings.

• Archives of Plastic Surgery
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• v.51 no.2
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• pp.156-162
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• 2024

Background Perioperative management in autologous breast reconstruction has gained focus in recent years. This study compares two pain management protocols in patients undergoing abdominal-based free flap breast reconstruction: a past protocol (PP) and a current protocol (CP)-both intended to reduce opioid consumption postoperatively. The PP entails use of a pain catheter in the abdominal wound and the CP consists of an intraoperative nerve block in addition to refinements in the oral pain management. We hypothesize that the CP reduces opioid consumption compared to PP. Methods From December 2017 to January 2020, 102 patients underwent breast reconstruction with an abdominal-based free flap. Two postoperative pain management strategies were used during the period; from December 2017 to September 2018, the PP was used which entailed the use of a pain catheter with ropivacaine applied in the abdominal wound with continuous distribution postoperatively in addition to paracetamol orally and oxycodone orally pro re nata (PRN). From October 2018 to January 2020, the CP was used. This protocol included a combination of intraoperative subfascial nerve block and a postoperative oral pain management regime that consisted of paracetamol, celecoxib, and gabapentin as well as oxycodone PRN. Results The CP group (n = 63) had lower opioid consumption compared to the PP group (n = 39) when examining all aspects of opioid consumption, including daily opioid usage in morphine milligram equivalents and total opioid usage during the stay (p < 0.001). The CP group had shorter length of hospital stay (LOS). Conclusion Introduction of the CP reduced opioid use and LOS was shorter.

• Hip & pelvis
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• v.35 no.3
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• pp.200-205
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• 2023

Purpose: The aim of this study was to assess the current status of venous thromboembolism (VTE) prevention in Korean patients with hip fractures. Materials and Methods: A survey using a questionnaire on the experiences and protocols of VTE prevention was conducted among 570 members of the Korean Hip Society. Results: A total of 97 surgeons responded, with a response rate of 17.0%. Of the 97 participants, 61.9% answered that they had encountered one or more cases of symptomatic VTE in the past year. Mechanical prophylaxis was applied most often (30.9%) until the point of ambulation in standard-risk patients and most often (34.0%) extended until discharge in high-risk patients. Chemical prophylaxis was most often prescribed for a particular period of time rather than for recovery of walking ability (24.7% in standard-risk patients and 26.8% in high-risk patients). Dual prophylaxis was administered in the standard-risk group by 58.8% of the participants and in the high-risk group by 83.5%. Among the participants, 73.2% answered that they had been attentive to wound complications during chemical prophylaxis. More than half of the participants (59.8%) reported that they did not perform routine screening for VTE after surgery. Conclusion: The results of our survey provided information regarding the current status of VTE prevention for patients undergoing surgery for treatment of hip fractures in Korea as well as a baseline for establishment of educational programs and guidelines in the future.