• Smart Structures and Systems
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• v.30 no.5
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• pp.521-535
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• 2022

Efficient management of deteriorating civil infrastructure is one of the most important research topics in many developed countries. In particular, the remote displacement measurement of bridges using linear variable differential transformers, global positioning systems, laser Doppler vibrometers, and computer vision technologies has been attempted extensively. This paper proposes a remote displacement measurement system using closed-circuit televisions (CCTVs) and a computer-vision-based method for in-situ bridge bearings having relatively large displacement due to temperature change in long term. The hardware of the system is composed of a reference target for displacement measurement, a CCTV to capture target images, a gateway to transmit images via a mobile network, and a central server to store and process transmitted images. The usage of CCTV capable of night vision capture and wireless data communication enable long-term 24-hour monitoring on wide range of bridge area. The computer vision algorithm to estimate displacement from the images involves image preprocessing for enhancing the circular features of the target, circular Hough transformation for detecting circles on the target in the whole field-of-view (FOV), and homography transformation for converting the movement of the target in the images into an actual expansion displacement. The simple target design and robust circle detection algorithm help to measure displacement using target images where the targets are far apart from each other. The proposed system is installed at the Tancheon Overpass located in Seoul, and field experiments are performed to evaluate the accuracy of circle detection and displacement measurements. The circle detection accuracy is evaluated using 28,542 images captured from 71 CCTVs installed at the testbed, and only 48 images (0.168%) fail to detect the circles on the target because of subpar imaging conditions. The accuracy of displacement measurement is evaluated using images captured for 17 days from three CCTVs; the average and root-mean-square errors are 0.10 and 0.131 mm, respectively, compared with a similar displacement measurement. The long-term operation of the system, as evaluated using 8-month data, shows high accuracy and stability of the proposed system.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.492-506
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• 2019

Heavy metal contaminants in the shooting range are mostly present in a warhead circle or a metal fragment present as a particle, these fine metal particles are weathered for a long period of time is very likely that the surface is present as an oxide or carbon oxide. In particular, lead which is a representative contaminant in the shooting range soil, is present as more fine particles because it increases the softness and is stretched well. Therefore, by physical washing experiment, we conducted a degree analysis, concentration of heavy metals by cubic diameter, composition analysis of metallic substances, and assessment of applicability of gravity, magnetism and floating selection. The experimental results FESEM analysis and the measurement results lead to the micro-balance was confirmed thatthe weight goes outless than the soil ofthe same size in a thinly sliced and side-shaped structure according to the dull characteristics it was confirmed that the high specific gravity applicability. In addition, the remediation efficiency evaluation results using a hydrocyclone applied to this showed a cumulative remediation efficiency of 71%,twice 80%, 3 times 91%. On the other hand, magnetic sifting showed a low efficiency of 17%,floating selection -35mesh (0.5mm)target soil showed a relatively high efficiency to 39% -10mesh (2mm) efficiency was only 16%. The target treatment diameter of soil washing should be 2mm to 0.075mm, which is applied to the actual equipment by adding an additional input classification, which would require management as additional installation costs and processes are constructed. As a result, it is found that the soilremediation of shooting range can be separately according to the size of the warhead. The size is larger than the gravel diameter to most 5.56mm, so it is possible to select a specific gravity using a high gravity. However, the contaminants present in the metal fragments were found to be processed by separating using a hydrocyclone of the soil washing according to the weight is less than the soil of the same particle size in a thinly fragmented structure.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.137-146
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• 1996

There has been no general agreement about optimal time for nerve surgery in the closed brachial plexus injury(BPI). From our early experiences, we knew by chance that spontaneous recovery in BPI patients may begin even later than 8 months after injury. Authors' strategy, which was based on our early experiences, for the treatment of closed fresh injury was 'wait and see' unlit 8 months after injury. From 1985 to 1994, we observed 103 patients with BPI. All of them did not have any operation until 8 months after injury. There were 95 men and 8 women with a mean age of 29 years. Motorcycle injury(31%) and vehicle accident(28%) were main causes of injury. Whole plexus types were observed in 56 patients(54%), upper plexus types in 29(28%), lower plexus types in 3(3%), and infraclavicular types in 15(15%). Electromyography was performed in all patients. This was repeated every three months to detect the recovery. Results were evaluated by authors' criteria, in which AMA system of brachial plexus impairment was modified. Duration of follow up was average 25 months. 47 patients(46%) showed spontaneous improvement, which was initially detected at average 7.8 months(range,3 months-16 months) after trauma by electromyography. The average score of these 47 patients improved from 14.8 points to 39.8 points.31 patients(30%) had nerve surgery such as nerve graft, neurotization or neurolysis. Average duration from injury to nerve surgery, was 10 months. Among 31 patients who had nerve surgery, 16 patients improved from preoperative 21.5 points to postoperative 36.3 points in average. Because spontaneous recovery began in average 7.8 months after injury, we think that it would be better to 'wait and see' for at least one year in patients with closed BPI expecting spontaneous recovery.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.247-252
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• 2011

Electrical conductivity, drainage, and irrigation amount of nutrient solution are important factors for determination of the mixing ratio of fresh and reused nutrient solutions in closed-loop soilless culture. Generally a fixed mixing ratio is applied in commercial scale greenhouses using solar radiation-based irrigation system. Although it ensures continuous supply of fresh nutrient solution in the mixing process, occasional discharge of the drainage is inevitably required. This study was conducted to compare the nutrient replenishing effect under different mixing processes and to investigate appropriate mixing process. For this experiment, a fixed mixing ratio (FR), modifiable mixing ratio (MR), and open-loop (OP) as control were applied. Mixing ratio was determined by a set value of EC for dilution of collected drainage in FR and the set values of 1.0 and $2.0dS{\cdot}m^{-1}$ were used as treatments (FR 1.0 and FR 2.0), respectively. In MR, mixing ratio was determined based on EC and volume of drainage within irrigation volume per event. The volume of drainage stored in the drainage tank tended to increase in FR 1.0. Although such trend was not observed in FR 2.0 and MR, the volume of drainage stored in MR was lower than that in FR 2.0. The ion balance of $Mg^{2+}:K^+:Ca^{2+}$ or $SO^{2-}_4:NO^-_3:PO^{3-}_4$ in the drainage and reused nutrient solution changed within a narrow range regardless of treatment.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.3
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• pp.27-36
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• 2014

The purpose of this study is to provide necessary information for the establishment of remodeling range needed first to support the future remodeling of rural housing. For this, this study examined landscape characteristics of rural housing such as an outer wall, a roof, a fence, and a gate which are main elements of forming the landscape of a rural village and rural residents' perception for remodeling. The results were as follows. The subject rural housing mostly had a timber structure and a masonry structure. Common roof types were a hip-and-gable roof and a gable roof. Frequent materials were a panel, a tile, and slate and common colors were primary colors such as reddish brown, black, and gray. A fence made of cement blocks and finished by a white paint was often found. A closed gate with iron frames was common. A standup kitchen and a flush toilet inside the house were common. The family members of rural residents were mostly two including a farmer husband and his wife. Elderly people of sixty and over were the most common. For residential environment satisfaction, a half of respondents were not unsatisfied with residential environment mostly due to an old house. Most respondents who were not satisfied with residential environment had high perception for the need of remodeling. The most commonly asked remodeling part was a roof, followed by a toilet, and an outer wall, indicating that the need of exterior remodeling was higher than that of interior remodeling. For a remodeling method, a total improvement was preferred. Although some rural village housing was improved by support of the government, local governments, or social groups, there are still many old houses. As this co-existence of improved houses and old houses hinders the landscape of rural village, it is necessary to give a support. But rural residents' requests should be first actively reflected to establish a guideline of supporting rural house remodeling.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.669-674
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• 2010

Background: Spontaneous hemopneumothorax is characterized by the accumulation of air and more than 400 mL of blood in pleural cavity without any apparent cause. It is a rare disease and can cause life-threatening situation. We analyzed clinical reviews of two medical centers to aid in optimal management. Material and Method: Retrospective review between March 2003 and August 2010 with 18 spontaneous hemopneumothorax patients was made. Result: These 18 patients were comprised of 15 male and 3 female with average 24.6 years (range 15~46 years). Almost patients (16) underwent a closed thoracostomy initially and 15 patients received video-assisted thoracic surgery (VATS). Mean postoperative chest tube removal was 2.9 days and one complication was post-removal pneumothorax. During the follow-up periods there were no other complications and recurrence. Conclusion: Proper initial diagnosis and management of spontaneous hemopneumothorax prevent significant hypovolemic shock. Video-assisted thoracic surgery should be considered an early surgical management in spontaneous hemopneumothorax. However conservative manage without bleb excision may be effective in selected patients.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.295-302
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• 2013

PURPOSE: The purpose of this study was to investigate the effect of short-term lumbar stabilization exercise to patients suffering from chronic low back pain(CLBP) on the strength of their lumbar flexor and extensor and the postural balance of them and to suggest effective treatment duration for them. METHODS: Study subjects were 20 patients with CLBP who's been reported the pain for more than 12 weeks. For these subjects, muscle strength of both extensor and flexor of lumbar and the balancing ability were measured before and after the intervention. Lumbar stabilization exercise was composed of matt, ball and sling exercise. The intervention was applied for total 12 sessions for 4 weeks (3 times a week) and each session was for 40 minutes. RESULT: For muscle strength of both extensor and flexor of lumbar, there was significant differences after the application of lumbar stabilization exercise(p<.05). For balancing ability, stabilization shows significant differences in all of the positions except PC(eyes closed on pillows)(p<.05). Distribution of weight shows no significant differences but it was generally distributed within normal range after the exercise and Fall index shows significant differences between before and after the exercise(p<.05). CONCLUSION: These results could have positive effect on deciding different periods of therapeutic intervention.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.13-21
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• 2004

Recently several techniques have been reported for the treatment of anterior open bite in adults characterized by molar intrusion with skeletal anchorage. In this study, five adult patients who had anterior open bite malocclusion were selected to undergo upper molar intrusion with midpalatal miniscrew to close the open bite. The aim of this study is (1) to validate true intrusion of molars in adults (2) to test the usefullness of midpalatal miniscrews as anchorage for intruding upper molars (3) to evaluate the skeletal and dental changes of open bite closure. The results are as follows. (1) All had true intrusion of the maxillary molars. Mean amount of molar intrusion was 3.4mm(range 1.5-5mm). (2) No movement of midpalatal miniscrew occurred during their use. (3) Open bite closure was achieved for all 5 patients. The mandible closed and B-point rotated anteriorly and upward. The mandibular plane angle and the occlusal plane angle decreased.

• Archives of Reconstructive Microsurgery
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• v.24 no.2
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• pp.56-61
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• 2015

Purpose: We report on the clinical result after coverage of a soft tissue defect on the medial foot and ankle with an adipofascial flap based on the perforator from the posterior tibia artery. Materials and Methods: Nine patients with soft tissue defects on the medial foot and ankle area from March 2009 to May 2014 underwent the procedure. Average age was 54 years old (range, 8~82 years). There were five male patients and four female patients. The causes of the defect were trauma (4), tumor (3), and infection (2). The pivot point of transposition of this flap is the lower perforator originating from the posterior tibia artery. The fatty tissue side of this flap could be used to resurface the defect. The donor site was closed primarily with the preserved skin, and a small caliber drain tube was used. The split-thickness skin graft was grafted to the flap and the wound. If the wound was still infected, this skin graft could be performed at a later date. Results: All flaps survived and normal soft tissue coverage was obtained for the medial foot and ankle of all patients after the skin graft. Normal footwear was possible for all cases because of thin coverage. There was an extension contracture on the medial ray of the foot, which was resolved by contracture release and skin graft. Conclusion: For the medial foot and ankle soft tissue defect, the medial crural adipofascial flap based on a perforator branch of the posterior tibia artery could be a good option to cover it.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.3
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• pp.251-256
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• 2009

In this research, we experimentally studied flow characteristic by applying PIV measuring techniques which could measure the point velocity of all flow field and measuring the unsteady velocity of surrounding disk generated in a short time. Time range of great velocity change following quick closing of the slide valve was within 0.1s and the cycle was presumed to be 0.12s as a result of comparison study between the result of point flow field and of existing pressure change. Also, surrounding disk flow inside the circular pipe was closed from the upper part and flow road was getting narrow and advanced to the lower part incidentally quickly there was a tendency that the size of the flow back velocity to the upper part immeadiately after the closure decreased to 4/120s and increased again. There was flow back velocity component in y/D=0.2 lower part by the influence of flow back to the upper part after complete closure and the vortex flow of 0.2D-size near y/D=0.7, x/D=-0.3 was observed.