• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.4
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• pp.16-30
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• 2019

In this study, we calculated the driving duration of individual vehicles according to the availability of rest facility on highway, and suggested indicators indicating the potential risk of accidents caused by long-term driving with weights based on the number of vehicles by driving duration of individual links. Based on this, the methodology for estimating the appropriate location of the highway rest facility considering the driving duration of individual vehicles was presented. Using the DSRC individual vehicle data collected from the highways, the appropriate location of the rest facility was calculated by considering the driving duration by classifying weekdays and weekends for the Gyeongbu Expressway. The results showed that the weekly and weekend high risk indicators were different. In the case of weekdays, the risk indicators of Gimchun JC to Kumho JC for Busan were high, while for weekends, the risk indicators of Ansung JC to Dongtan JC for Seoul and Ansung IC to Bukchunan IC for Busan were high. This study has great significance in that it provides a framework for detailed analysis of link units by using non-aggregated data of individual vehicle units. In addition, it is significant that the reasonable driving duration reflecting the behavior of individual vehicles was calculated by analyzing the use of rest facilities.

• Physical Therapy Korea
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• v.26 no.3
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• pp.11-22
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• 2019

Background: Sling exercises are frequently used for the rehabilitation process of patients with shoulder joint injuries, but research on the significant frequency intensity and appropriate treatment duration for sling exercises with local vibration stimulation is lacking. Objects: The aim of this study was to investigate the effects of sling exercise with vibration on shoulder range of motion (ROM), muscle strength, pain, and dysfunction in patients with a medical diagnosis of shoulder joint injury. Methods: Twenty-two patients were randomly assigned to the experiment and control groups. Six sling exercises with and without 50 Hz vibrations were applied in the experiment and control groups, respectively. Each exercise consisted of 3 sets of 5 repetitions performed for 6 weeks. The assessment tools used included shoulder joint range of motion, muscle strength, pain level, and shoulder pain and disability index for functional disability. We conducted re-evaluations before and 3 and 6 weeks after intervention. The changes in the measurement variables were analyzed and compared between the two groups. Results: The ROM of the external rotation of the shoulder joint had a significant interaction between the group and the measurement point (F=3.652, p<.05). In both groups, we found a significant increase in external rotation angle between the measurement points (p<.05). The flexor strength of the shoulder joint significant interaction between the group and the measurement point (F=4.247, p<.05). Both the experiment (p<.01) and control groups (p<.05) showed a significant increase in shoulder flexor strength at the measurement points. After 6 weeks of the interventions, both the groups showed significantly improved VAS (p<.01), SPADI (p<.01), and orthopedic tests (p<.01). However, there was no significant difference between the group and the measurement point in terms of the clinical outcomes observed. Conclusion: The sling exercise with local vibration of 50 Hz affected the external rotation of the shoulder range of motion and improved shoulder flexor strength in the patients with shoulder injuries. Therefore, we propose the use of the sling exercise intervention with vibration in the exercise rehabilitation of patients with shoulder joint injuries.

• Journal of the Korean neurological association
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• v.36 no.4
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• pp.294-301
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• 2018

Background: Neuroimaging can play a crucial role in discovering potential abnormalities to cause secondary headache. There has been a progress in the fields of headache diagnosis and neuroimaging in the past two decades. We sought to investigate neuroimaging findings according to headache disorders, age, sex, and imaging modalities in first-visit headache patients. Methods: We used data of consecutive first-visit headache patients from 9 university and 2 general referral hospitals. The International Classification of Headache Disorders, third edition, beta version was used in headache diagnosis. We finally enrolled 1,080 patients undertook neuroimaging in this study. Results: Among 1,080 patients (mean age: $47.7{\pm}14.3$, female: 60.8%), proportions of headache diagnosis were as follows: primary headaches, n=926 (85.7%); secondary headaches, n=110 (10.2%); and cranial neuropathies and other headaches, n=43 (4.1%). Of them, 591 patients (54.7%) received magnetic resonance imaging (MRI). Neuroimaging abnormalities were found in 232 patients (21.5%), and their proportions were higher in older age groups and male sex. Chronic cerebral ischemia was the most common finding (n=88, 8.1%), whereas 76 patients (7.0%) were found to have clinically significant abnormalities such as primary brain tumor, cancer metastasis, and headache-relevant cerebrovascular disease. Patients underwent MRI were four times more likely to have neuroimaging abnormalities than those underwent computed tomography (33.3% vs. 7.2%, p<0.001). Conclusions: In this study, the findings of neuroimaging differed according to headache disorders, age, sex, and imaging modalities. MRI can be a preferable neuroimaging modality to identify potential causes of headache.

• Journal of The Korean Association of Information Education
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• v.26 no.2
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• pp.129-140
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• 2022

Our society is undergoing rapid changes due to COVID-19, and in particular, online learning using digital technology is being tried in various forms in the educational field. A change has occurred. However, the limitations of distance learning, such as reduced learning immersion in non-face-to-face educational situations, lack of interaction between teachers and learners, and lower basic academic ability, are constantly being raised, and an appropriate educational strategy is needed to solve these problems. This study focused on the concept of 'Metaverse' based on the interaction between the virtual world and the real world, and tried to verify the effectiveness of educational activities based on it. In detail, we propose an educational framework for realizing flipped learning in the Metaverse Virtual Classroom, and a frame developed by measuring the learning immersion of a single group with a teaching/learning program developed based on this. The effectiveness of the work was verified. When the metaverse platform-based flip learning framework and education program proposed in this study were applied, it was confirmed that learners' immersion in learning was improved.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.56-64
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• 2021

Leakage due to deterioration and damage is one of the major causes of volume change by freezing and thawing, and it leads micro-cracking and surface scaling in concrete structures. The deterioration of damaged concrete accelerates with the chloride attack. Thus, in the detailed guidelines for facility performance evaluation (2020), the quality of cover concrete and the freeze-thaw (FT) repetition cycle were newly suggested for concrete durability assessment. The quality of cover concrete should be evaluated by the rebound hammer test and the FT repetition cycle should be also considered in the deterioration environmental assessment. This study suggested the application of fast dynamic based nonlinear ultrasound method to monitor initial micro-scale damage under freezing and thawing environment. Concrete specimens were fabricated with different water-cement ratios (40%, 60%) and air contents (1.5% and 3.0%). The compressive strength, rebound number, relative dynamic modulus, and nonlinear ultrasound were measured with different FT cycles. The scanning electron microscopy was also performed to investigate the micro-scale FT damage. As a result, both the rebound number and the relative dynamic modulus had difficulty to detect early damage but the proposed method showed a potential to detect initial micro-scale damage and predict the FT resistance performance of concrete.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.633-641
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• 2021

The study performed long-term performacne evaluation on the hot mix asphalt using the steel slag aggregates and Reclaimed Asphalt Pavement (RAP). The laboratory comparative evaluation was conducted between conventional Hot Mix Asphalt (HMA) which is entitled WC-2 and HMA containing steel slag and RAP which is entitled ES WC-2(R). Dynamic stability test, dynamic modulus test, and fatigue crack test were conducted during the comparative evaluation process. The dynamic stability test result showed that ES WC-2(R) was 140% higher than WC-2. It is noted that ES WC-2(R) showed no inflection point whereas WC-2 showed inflection point during the dynamic stability test which implies ES WC-2(R) has the higher moisture susceptability than WC-2. The dynamic modulus of ES WC-2(R) were 342.3%, 486.7%, and 350.0% higher than WC-2 at medium temperature of 21℃, low temperature of -10℃, and high temperature of 38℃ respectively. The test result showed that rutting resistance of ES WC-2(R) is higher than WC-2 at all temperature spectrum. The fatigue resistance of ES WC-2(R) were 31.7%, 325.3%, 899.9% higher at low stress level, medium stress level, and high stress level, respectively. The test result showed that ES WC-2(R) is higher than WC-2 at all stress levels. Based on the laboratory comparative evaluation, The in-situ scale Accelerated Pavement Test (APT) was conducted comparing WC-2 and WC-2(R). APT found that the rutting resistance of WC-2(R) was 45% higher than WC-2.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.553-564
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• 2022

Concrete is a representative composite material that shows excellent performance in the construction field. However, it is a brittle and nonhomogeneous material and exhibits weak behavior against bending and tensile forces. To compensate for such weakens, fiber reinforcement has been utilized, and steel fiber has been recognized as one of the best material for such purpose. However, steel fiber can seriously affect the durability of concrete exposed to the marine environment due to the corrosion caused by chlorine ions. This study intended to evaluate the mechanical performance of steel fiber reinforce concrete during and after repeated wet/dry cycles in salt solution. According to the experimental results, there was no reduction in the relative dynamic modulus of concrete during the repeated wet/dry cycles in salt solution for 37 weeks. Flexural strength was not decreased after completion of repeated wet/dry cycles in salt solution. There was no sign of corrosion in steel fibers after visual observation of fractured surface. However, the flexural toughness was decreased, and this is because about half of the concrete specimen showed failure before reaching the maximum displacement of 3 mm. Although repeated wet/dry cycles in salt solution did not cause cracks in concrete through corrosion of steel fibers, specific attention is required because it can reduce flexural toughness of steel fiber reinforced concrete.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.41-48
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• 2022

The purpose of this study is to compare the meaning of the experience of robot play in the free play time of 5-year-old children in daycare centers with the experience of 5-year-old children in the structural group activities of teachers. To this end, a total of 32 children (15 in the experimental group and 17 in the comparative group) aged 5 were conducted for 1 hour three times a week for 10 weeks. Robots were supported as toys in the classroom of the experimental group, and children in the comparative group freely experienced robot exploration and play during free play time, and children in the comparative group learned the robot's functions and performed structural group activities based on the 2019 Revised Nuri Curriculum national-level curriculum. As a result of analyzing the difference between pre-test and post-test, the use of robots in free play showed a significant effect in creativity and fluency of children, and a significant effect in expression of pleasure in playability. These results suggest that robots are meaningful as play materials in early childhood education, which aims for infant-led free play, and that it is worth studying the robot experiences of children in these free situations in the future.

• Journal of the Korean Burn Society
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• v.22 no.2
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• pp.66-70
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• 2019

Purpose: The necrotizing fasciitis is a terrifying infectious disease that can rapidly spreads to surrounding tissues when fascia is infected and it can cause sepsis to death if not properly diagnosed and treated. The purpose of this study is to investigate the characteristics, causes, and treatment methods of necrotizing fasciitis in Korea through reviewing patients admitted to our burn center. Methods: 21 patients with necrotizing fasciitis were selected for this study among those inpatients with electronic medical records (EMR) admitted to Hallym University Hangang Sacred Heart Medical Center from Jan 1, 2008 to June 30, 2019. The medical records and wound photos of those 21 selected subjects were reviewed. Results: There were 13 male and 8 female patients and mean age was 58.76 years old. 13 of 21 subjects were survived and 8 died (38% mortality rate). The surgical treatments performed were I&D, fasciotomy, debridement, allograft, burring, STSG, flap, and amputation. The most common causes were burns in 9 subjects (6 contact burns) and cellulitis occurred on skins in 5 subjects. And other various causes were observed as fournier's gangrene, stab wound, intramuscular injection, tumor and bleu toe syndrome (toe necrosis). The infected areas were 11 feet and legs, 7 hips, 3 abdomen and trunk in 21 subjects. Of the 8 deaths, 3 were infected in feet and legs, 2 were infected in hips, and 2 were infected in abdomen and trunk. As for underlying diseases, 12 patients with hypertension or diabetes were the highest and others such as cancer and stroke were found. Conclusion: The only method to increase the survival rate is to 'suspect' the disease as much as possible and perform early extensive excision. It is advisable to treat the disease by the burn center to properly provide adequate and optimal wound management, infection control, medical care and nutritional supports.

• Journal of Industrial Convergence
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• v.21 no.8
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• pp.97-110
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• 2023

This study presents a systematic literature review aimed at integrating and analyzing the research findings regarding the components of various self-care intervention programs conducted for individuals with chronic obstructive pulmonary disease (COPD) both domestically and internationally. The paper selection criteria were established based on materials from PubMed, CINAHL, EMBASE, /MEDLINE, RISS, DBpia, KISS, and KMbase databases, covering the period from January 1, 2000, to September 30, 2022. The inclusion criteria included controlled pre-post experimental study designs. A total of 23 studies were included in this systematic review. The intervention-related factors examined included the sample size, type of intervention mediator, intervention frequency, and duration. Additionally, factors associated with intervention effects, such as measurement tools and variables, were analyzed. The findings of the analysis support the notion that self-care intervention programs for COPD can contribute to the prevention of symptom exacerbation and hospital readmissions among patients. Consequently, the development of a tailored self-care intervention program specifically designed for COPD patients in South Korea is warranted, considering aspects such as patient accessibility, convenience, and motivation for long-term sustainability.