• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.127-133
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• 2021

A recent study of people physically falling focused on analyzing the motions of the falls using a recurrent neural network (RNN) and a deep learning approach to get good results from detecting 2D human poses from a single color image. In this paper, we investigate a detection method for estimating the position of the head and shoulder keypoints and the acceleration of positional change using the skeletal keypoints information extracted using PoseNet from an image obtained with a low-cost 2D RGB camera, increasing the accuracy of judgments about the falls. In particular, we propose a fall detection method based on the characteristics of post-fall posture in the fall motion-analysis method. A public data set was used to extract human skeletal features, and as a result of an experiment to find a feature extraction method that can achieve high classification accuracy, the proposed method showed a 99.8% success rate in detecting falls more effectively than a conventional, primitive skeletal data-use method.

• Korean Journal of Applied Biomechanics
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• v.31 no.1
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• pp.1-15
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• 2021

Objective: The aim of this study was to investigate 1) the difference in static lower extremity alignment (SLEA) according to a history of lateral ankle sprain (LAS), 2) to identify SLEA factors affecting LAS, and 3) to present the cut-off value and 4) the usefulness and limitations of the SLEA measurement. Method: This case-control study recruited 88 men (age: 27.78±4.69 yrs) and 39 women (age: 24.62±4.20 yrs) subjects with and without LAS. SLEA measurement protocol included Q angle, tibiofemoral angle, genu recurvatum, rear foot (RF) angle, tibal varum and torsion, navicular drop, ankle dorsiflexion range of motion (DF ROM). Independent t-test, logistic regression and receiver operating characteristic (ROC) curve were used for statistical analysis. Results: Men with a history of LAS had significantly smaller Q angles both in standing and in supine position, while women with a history of LAS had significantly greater DF ROM in non-weight bearing (NWB; p < 0.05). Logistic regression model suggests tibial varum (OR = 0.779, p = 0.021) and WB DF ROM (OR = 1.067, p = 0.045) were associated with LAS in men. In case of women, there were no significant SLEA factors for LAS, however, ROC curve analysis revealed standing RF angle (AUC = 0.647, p = 0.028) and NWB DF ROM (AUC = 0.648, p = 0.026) could be affecting factors for LAS. Conclusion: There are differences in SLEA according to the history of LAS, furthermore, the identified items were different by sex. In case of men, tibial varum and WB DF ROM affect LAS occurrence. Standing RF angle and NWB DF ROM of women could be a predictor for LAS. However, since the sensitivity and specificity in most of the SLEA measurements are low, kinematic in dynamic tasks should be considered together for a more accurate evaluation of LAS risk.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.587-598
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• 2021

This study aims to develop a multi-camera based MMS (Mobile Mapping System) technology for building a HD (High Definition) map for autonomous driving and for quick update. To replace expensive lidar sensors and reduce long processing times, we intend to develop a low-cost and efficient MMS by applying multiple cameras and real-time data pre-processing. To this end, multi-camera storage technology development, multi-camera time synchronization technology development, and MMS prototype development were performed. We developed a storage module for real-time JPG compression of high-speed images acquired from multiple cameras, and developed an event signal and GNSS (Global Navigation Satellite System) time server-based synchronization method to record the exposure time multiple images taken in real time. And based on the requirements of each sector, MMS was designed and prototypes were produced. Finally, to verify the performance of the manufactured multi-camera-based MMS, data were acquired from an actual 1,000 km road and quantitative evaluation was performed. As a result of the evaluation, the time synchronization performance was less than 1/1000 second, and the position accuracy of the point cloud obtained through SFM (Structure from Motion) image processing was around 5 cm. Through the evaluation results, it was found that the multi-camera based MMS technology developed in this study showed the performance that satisfies the criteria for building a HD map.

• Composites Research
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• v.34 no.6
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• pp.357-372
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• 2021

The energy harvesting device is known to be promising as an alternative to solve the resource shortage caused by the depletion of petroleum resources. In order to overcome the limitations (environmental pollution and low mechanical properties) of piezoelectric elements capable of converting mechanical motion into electrical energy, many studies have been conducted on a polymer matrix-based composite piezoelectric energy harvesting device. In this paper, the output performance and related applications of the reported piezoelectric composites are reviewed based on the applied materials and processes. As for the piezoelectric fillers, zinc oxide, which is advantageous in terms of eco-friendliness, biocompatibility, and flexibility, as well as ceramic fillers based on lead zirconate titanate and barium titanate, were reviewed. The polymer matrix was classified into piezoelectric polymers composed of polyvinylidene fluoride and copolymers, and flexible polymers based on epoxy and polydimethylsiloxane, to discuss piezoelectric synergy of composite materials and improvement of piezoelectric output by high external force application, respectively. In addition, the effect of improving the conductivity or the mechanical properties of composite material by the application of a metal or carbon-based secondary filler on the output performance of the piezoelectric harvesting device was explained in terms of the structure of the composite material. Composite material-based piezoelectric harvesting devices, which can be applied to small electronic devices, smart sensors, and medicine with improved performance, can provide potential insights as a power source for wireless electronic devices expected to be encountered in future daily life.

• Journal of Veterinary Clinics
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• v.40 no.2
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• pp.93-103
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• 2023

The tendon is a dense connective tissue that connects muscle to bone and plays an essential role in joint motion. The injured tendon heals slowly owing to its low cellularity and vascularity. This study aimed to evaluate and compare the effects of regenerative injection therapy (RIT), 20 % dextrose prolotherapy (DP), and platelet-rich plasma (PRP) injections that can promote tendon healing. Twenty-one New Zealand white rabbits were divided into the control, DP, and PRP treatment groups. The superficial digital flexor tendon (SDFT) of the right hindlimb of each rabbit was used. A round defect of 2 mm was induced. Approximately 0.2 mL of 20% dextrose and autologous PRP were injected into the proximal and distal ends of the SDFT mass. Radiographic and ultrasonographic examination and cross-sectional area (CSA) calculations were performed pre-operatively and at 2, 4, and 8 weeks. The SDFT of both limbs was transected for biomechanical and histomorphometric evaluations. The SDFT of the left limb was transected for intact control. Semi-quantitative analysis was performed to evaluate the histomorphometric properties. Additional analysis was performed using H&E, Masson's trichrome, and immunohistochemical staining. The biomechanical evaluation showed that the treatment groups had higher tensile strength compared to the defect control group, while the PRP group had higher tensile strength than the DP group. On histological examination, the treatment groups appeared to be relatively closer to the remodeling phase of the healing process than the defect control group; the characteristics of the PRP group were closer to the remodeling phase than those of the DP group. The ultrasonographic examination showed different tendencies. Increased values in the CSA were observed during the early period in the treatment groups. This study suggests that PRP and DP can promote the healing of tendon injury, and these effects were superior with PRP than that with DP.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.38.2-39
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• 2021

I will presents the analysis of the gas properties of the protoplanetary disk surrounding the young low-mass (about 1.2M_sun) triple star, GG Tau A. This work makes use of ALMA observations of rotational lines of CO (¹²CO, ¹³CO and C¹⁸O) together NOEMA observations of a few dozens of other molecules. While the CO emission gives information on the molecular layer close to the disk atmosphere, its less abundant isotopologues ¹³CO and C¹⁸O bring information much deeper in the molecular layer. I will present the analysis of the morphology and kinematics of the gas disk using the CO isotopologues. A radiative transfer model of the ring in CO isotopologues will also be presented. The subtraction of this model from the original data reveals the weak emission of the molecular gas lying inside the cavity. Thus, I am able to evaluate the properties of the gas inside the cavity, such as the gas dynamics, excitation conditions, and the amount of mass in the cavity. High angular resolution observations of CO reveals sprials induced by embedded planet(s) located near the 3:2:1 mean-motion resonance that help to explain the special morphology of the circumbinary disk. I also discuss some chemical properties of the GG Tau A disk. I report the first detection of H2S and C₂S in a protoplanetary disk. The molecule abundance relative to ¹³CO of about twenties other molecules will also be given. In GG Tau A, the detections of rare molecules such as H₂S and C₂S have been probably possible because the disk is more massive (a factor about 3-5) than other disks where the molecules was searched. Such a large disk mass makes the system suitable to detect rare molecules and to study cold-chemistry in protoplanetary disks.

• Journal of Korean Medicine Rehabilitation
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• v.34 no.2
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• pp.85-100
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• 2024

Objectives This study aims to analyze clinical studies on subacromial-subdeltoid (SA-SD) bursitis and propose future directions for clinical research on SA-SD bursitis. Methods We searched eight databases to investigate research trends in Korean medicine treatments for SA-SD bursitis up to November 2023. A total of thirty-one studies were included in this analysis. Results Among the included studies, there were six case reports from Korea, fifteen case reports, and ten randomized controlled trials from abroad. Various interventions were uesd, including acupuncture, pharmacopuncture, manual therapy, electro-acupuncture, cupping, physiotherapy, acupotomy, warm-acupuncture, herbal medicine, and moxibustion. The evaluation tools used in these studies included the total effective rate, visual analogue scale, range of motion, and numeral rating scale. Conclusions This study provides an overview of the research trends in Korean medicine treatments for SA-SD bursitis. However, given the low quality and small sample sizes of the studies, the evidence supporting effect of Korean medicine treatments for SA-SD bursitis was insufficient. Further clinical trials and systematic reviews are required.

• The Journal of Korean Academy of Sensory Integration
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• v.6 no.1
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• pp.1-12
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• 2008

Objective : The purpose of this study is to provide reference to functional level of sensory integration of in the low-grads school age, based on the Clinical Observation of Motor and Postural Skills (COMPS) and to examine correlation between the function of sensory integration and academic achievement. Method : Two schools ("J" and "S") have been selected indiscriminately among 56 elementary schools located in Gimhae-si, GyeongNam and then one class from each school was voluntarily chosen among all second-grade classes of the schools. The total number of students in those two classes was 69 (34 boys and 35 girls). Subjects had no developmental problem and no history of referral regarding neurological conditions. Three skilled researchers administrated the COMPS together, and each researcher executed two sub-items of the COMPS. As result of the academic achievement, score data of midterm- and final-exam in the spring semester were collected. The scores of 'Korean language' and 'Math', common examination subjects in both schools, were utilized for data analysis in this study. Results : Statically, there was no significant correlation between the COMPS Weighted Scores and any academic achievements. In a dispersion graphic analysis, however, the total achievement showed significant negative-correlation with the area of 'Rapid Forearm Rotation' and significant positive-correlation with the area of 'Supine Flexion'. In terms of the Math achievement, there are significant negative-correlation with rapid forearm rotation and asymmetrical tonic neck reflex, and significant positive-correlation with the area of 'Supine Flexion'. Students with higher score of the Korean language showed a tendency to get higher Weighted Score and Minus Adjustment Score, and those with lower score of the Math showed a tendency to get higher COMPS scores in all area except the area of 'Supine Flexion'. There was a statically significant difference in the COMPS scores depend on the age among general characteristics. As student older, all COMPS scores, except those in the area of 'Slow Motion' and 'Supine Flexion, were higher. Conclusions : There is somehow reliable correlation between sensory integration function and academic achievement although no statistical significance found in this study. The information from this study may contribute to initiate developing a normative-reference to screen earlier and more alertly sensory integration dysfunctions for school-age children. Further study is recommended trying to find out more reliable matter regarding low grade- schooler's academic achievement.

• Journal of the Korean earth science society
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• v.33 no.4
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• pp.360-375
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• 2012

The purpose of this study was to compare 10th grade students' understanding of concepts about the plates' motions depending on the different spatial ability. Based on previous studies and literature reviews, two instruments were selected and used in this study. The Spatial Perception Test developed in Korean Testing Center was applied to measure students' spatial ability. Another instrument for testing students' understandings of plates' motions consists of a total of 10 items. The instruments were distributed to 118 students who were 10th graders in metropolitan city. The results are as follows: First, a correlation coefficient between conceptual understanding of plates' motions and spatial ability was r=0.439 (p<.01). It indicates that conceptual plates' motions and spatial ability have a moderate relationship. The students were divided into two groups (high and low) by spatial ability. The independent t-test was performed and reveals that the statistically significant difference between high and low groups. On the other hand, the 6 students (3 higher spatial ability students and 3 lowers) were selected and interviewed individually to find the differences in their understanding of the concept of plates' motions. The findings from interviews indicate that most students recognized about concepts of trench and ocean ridge, a rise and drop of the mantle, and divergent and convergent boundaries. However, students had misconceptions about section of trench and ocean ridge. In addition, the students who had higher spatial ability knew the more proper concepts about the creation and extinction of plate, crustal movements, and bottom of the ocean extension, whereas the students who had the lower spatial ability had misconceptions.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.206-212
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• 2007

Purpose: Heterotopic ossification is a well-known postoperative and post-traumatic complication of the elbow. We reviewed the treatment outcome for the use of low-dose radiation after surgical intervention of the elbow to prevent recurrence of heterotopic ossification (HO). Materials and Methods: Forty-five patients with HO underwent surgical intervention and postoperative radiotherapy of the elbow. The median age of the patients was 29 years ($16{\sim}75$ years), and 27 of the patients were men and 18 were women. The occurrence of HO was mainly due to surgery after fracture (24/45) and traumatic injury (21/45). Limitation of the range of motion (ROM) was the most common symptom of the patients. Thirty-four patients received postoperative radiotherapy with a dose of 8 Gy in 2 fractions; 5 patients received a dose of 10 Gy in 5 fractions and 6 patients received a dose of 7 Gy in 1 fraction. Postoperative radiotherapy was given on the first two postoperative days for most of the patients. Sixteen patients were not given anti-inflammatory medication and 29 patients were given NSAIDs for $1{\sim}8$ months. Results: After a median follow-up period of 18 months (range $6{\sim}72$ months), 41 patients showed clinical improvement and two patients did not show improvement. Assessment of the ROM showed a mean improvement from $0{\sim}135^{\circ}$ to $60{\sim}145^{\circ}$ (p=0.028), and assessment of the functional outcome according to MEPI was from ($15{\sim}95$) to ($80{\sim}100$) (p<0.0001). Two of the 34 patients that were followed-up with radiography had mild radiological recurrence of heterotopic ossification. No complications were observed after the radiotherapy. Conclusion: These results suggested that low-dose radiation administered after surgical intervention is safe and effective to prevent the recurrence of HO in the elbow.