• Journal of the Korean Society for Nondestructive Testing
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• v.11 no.1
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• pp.7-12
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• 1991

The multi-frequency eddy current technique has been used for evaluation of various type of defects in tubings. However, this technique is not sufficient to detect and evaluate the defect in tubings if the defect is located in the geometrically complicated area(e. g. tube support plate, anti-vibration bar, tubesheet area) and mixing residue signal is significant to the defect signal. In order to improve the reliability of the multi-frequency eddy current technique, the effect of the interaction of mixing residue after frequency mixing with a function of distances between the defect and the tube support plate boundary has been analyzed theoretically. The experimental results have been discussed with the theoretical developments. The calculation shows the interaction between the two neighboring signal sources could be significant within the range of approximately 1.0mm with the experimental condition.

• Archives of Reconstructive Microsurgery
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• v.17 no.2
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• pp.82-86
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• 2008

Purpose: Soft tissue defect can occur on the posterior aspect of the elbow after trauma or fracture fixation. To cover the defect and maintain elbow functions, various flap surgeries including latissimus dorsi muscle flap, lateral arm flap and radial forearm flap can be performed. We present the clinical results of transposition lateral arm flap for coverage of the elbow defect and discuss the cause of posterior soft tissue necrosis after fracture fixation. Materials and Methods: Two patients who had posterior soft tissue defect of the elbow after open reduction of the fractures around the elbow were treated with transposition lateral arm flap. The mean size of skin defect was 20 $cm^2$. The flap was elevated with posterior radial collateral artery pedicle and transposed to the defect area. Donor defect was covered with split thickness skin graft. The elbow was immobilized for 1 week in extended position and active range of motion was permitted. Results: All two cases of transposition lateral arm flap survived without marginal necrosis. The average range of motion of the elbow was 10~115 degrees. Mayo elbow performance score was 72 and Korean DASH score was 23. Conclusion: When elbow fractures are fixed with three simultaneous plates and screws, skin necrosis can occur on the posterior aspect of the elbow around olecranon area. If the size of skin defect is relatively small, transposition lateral arm flap is very useful option for orthopaedic surgeons without microsurgical technique.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.3
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• pp.361-378
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• 1992

The purpose of this investigation was to evaluate the effect of the porous hydroxyapatite particles (Interpore $200^{(R)}$) and guided tissue regeneration membrane ($Gore-Tex^{TM}$ augmentation material) on amount and shape of generating new bone adjacent to implant. Implants were placed immediately after extraction in the bilateral 3rd, 4th premolars of the mandible of the adult dogs. In all experimental groups, artificial bony defects were formed at the buccal cortex area, 3.3mm in width and 3.0mm in depth. In the control group : sutured without HA particles & membranes after placing implants, the experimental group 1 : membrane was place over the artificial bony defect, the experimental group 2 : bony defect was filled with HA particles and covered with membrane. The examination of bone-implant interfaces using light microscope and fluorescent microscope concluded as follows. 1. In all three experimental groups, osseointegration was observed without epithelial migration. 2. In the healing degree of bony defect area, the experimental group 1, 2 showed more prominent healing than control group, and the experimental group 1 showed the most excellent bone formation. 3. In fluorescent microscopic finding, bone remodeling was observed in regenerated bone tissue at defect area of experimental group 1, but in experimental group 2, irregular, discontinuous linear fluorescence was observed at the lower portion of defect area and sign of bone remodeling was weak.

• Archives of Craniofacial Surgery
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• v.10 no.2
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• pp.71-75
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• 2009

Purpose: Recently, orbital wall fracture is common injuries in the face. Facial CT is essential for the accurate diagnosis and appropriate treatment to reconstruct of the orbital wall. The objective of this study was to report the method for accurate measurement of area and shape of the bony defect in the blow-out fractures using facial CT in prior to surgery. Methods: The authors experienced 46 cases of orbital wall fractures and examined for diplopia, sensory disturbance in the area of distribution of the infraorbital nerve, and enophthalmos in the preoperation and followed 1 months after surgery, from August 2007 to May 2008. Bony defect was predicted by measuring continuous defect size from 3 mm interval facial CT. Copying from the defect model (template), we reconstructed orbital wall with resorbable sheet (Inion $CPS^{(R)}$ Inion Oy, Tampere, Finland). Results: One months after surgery using this method, 26 (100%) of the 26 patients improved in the diplopia and sensory disturbance in the area of distribution of the infraorbital nerve. Also 8 (72.7%) of the 11 patients had enophthalmos took favorable turn. Conclusion: This accurate and time-saving method is practicable for determining the location, shape and size of the bony defect. Using this method, we can reconstruct orbital wall fracture fastly and precisely.

• Imaging Science in Dentistry
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• v.40 no.3
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• pp.137-142
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• 2010

Purpose : This study was performed to evaluate the diagnostic ability of ultrasonography in detection of bone defects and new bone formation. Materials and Methods : Experimental bony defects were prepared on the parietal bone samples acquired from 3.5 kg New Zealand male rabbits. The defects were evaluated using ultrasonography and CBCT, and examined histologically at interval of 1, 3, 6, and 8 weeks. Results : Ultrasonograph demonstrated hyperechogenicity in the defect area at 3 weeks and broadened hyperechogenicity from the margin of bone defect at 6 and 8 weeks due to new bone formation. On the CBCT images, new bone formation was first observed at 3 weeks around the margin of the defect, and showed gradually increase at 6 and 8 weeks. Histologic findings revealed existence of the fibroblasts and fibrous connective tissue with abundant capillary vessels only at 1 week, but osteoid tissue and newly formed trabecular bone at 3 weeks. Bone remodeling in the defect area was observed at 6 weeks and increased calcification and dense trabecular bone formation was observed at 8 weeks. Conclusions : Ultrasonograph proved to be a very useful diagnostic tool in detecting the bony defect and new bone formation. Additionally, ultrasonography provided valuable information regarding the blood supply around the defect area.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.256-261
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• 2013

In the steel manufacturing area, researches for defect inspection receive a big attention for quality control. This paper proposes an algorithm to detect a scratch defect on steel billets. This algorithm takes ROIs (Regions of Interest), and extracts 11 features which represent properties of defect on a ROI. SVM (Support Vector Machine) is used to classify defect and normal ROIs. The algorithm classifies a frame image of a Billet as a defect image if there is one or more defect ROIs. In the experiments, the proposed algorithm had reliable classifying accuracy.

• Archives of Plastic Surgery
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• v.40 no.4
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• pp.335-340
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• 2013

Background In patients with medial orbital wall fracture, predicting the correlation between the degree of enophthalmos and the extent of fracture is essential for deciding on surgical treatment. We conducted this retrospective study to identify the correlation between the two parameters. Methods We quantitatively analyzed the correlation between the area of the bone defect and the degree of enophthalmos on computed tomography scans in 81 patients with medial orbital wall fracture who had been left untreated for more than six months. Results There was a significant linear positive correlation between the area of the medial orbital wall fracture and the degree of enophthalmos with a formula of E=0.705A+0.061 (E, the degree of enophthalmos; A, the area of bone defect) (Pearson's correlation coefficient, 0.812) (P<0.05). In addition, that there were no cases in which the degree of enophthalmos was greater than 2 mm when the area of the medial orbital wall fracture was smaller than $1.90cm^2$. Conclusions Our results indicate not only that 2 mm of enophthalmos corresponds to a bone defect area of approximately $2.75cm^2$ in patients with medial orbital wall fracture but also that the degree of enophthalmos could be quantitatively predicted based on the area of the bone defect even more than six months after trauma.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.272-280
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• 1991

The aims of this study were to investigate the feasivility of analyzing a few sorting factors such as size, coloration and defect of apples with a monochrome image processing system and to find apparent properties which could be effectively used for apple sorting. The results are summarized as follows. 1. A computer program was made to analyze the projection area, coloration and defect of an apple with a monochrome image processing system. 2. The algorithm developed to compute the projedtion area of an apple was between on the proportional relation between a given reference area and the corresponding number of pixels, and the computing time was 0.74 to 0.82 second depending on the size of apple. 3. The coloration of an apple was expressed as the ratio of the gray value of a reference color to that of a given bounded area of the stem end surface (defined as coloration index), and the computing time was about 3.0 seconds with this algorithm. 4. Defect of an apple could be isolated by lowpass filtering and image subtraction but it took about 20 seconds in computing time. 5. The coloration of the Fuji apple could be classified into 3 to 4 groups by the coloration index and also, it was found that the correlation coefficient between the indices and sugar contents was 0.74. 6. The coloration index obtained from a given bounded area of the stem end side of the Fuji apple could represent the coloration of total surface with a correlation coefficient of 0.922.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.894-898
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• 2011

Purpose: Coverage of full-thickness large flank defect is a challenging procedure for plastic surgeons. Some authors have reported external oblique turnover muscle flap with skin grafting, inferiorly based rectus abdominis musculocutaneous flap, and two independent pedicled perforator flaps for flank reconstruction. But these flaps can cover only certain portions of the flank and may not be helpful for larger or more lateral defects. We report a case of large flank defect after resection of extraskeletal Ewing's sarcoma which is successfully reconstructed with reverse latissimus dorsi myocutaneous flap. Methods: A 24-year-old male patient had $13.0{\times}7.0{\times}14.0$ cm sized Ewing's sarcoma on his right flank area. Department of chest surgery and general surgery operation team resected the mass with 5.0 cm safety margin. Tenth, eleventh and twelfth ribs, latissimus dorsi muscle, internal and external oblique muscles and peritoneum were partially resected. The peritoneal defect was repaired with double layer of Prolene mesh by general surgeons. $24{\times}25$ cm sized soft tissue defect was noted and the authors designed reverse latissimus dorsi myocutaneous flap with $21{\times}10$ cm sized skin island on right back area. To achieve sufficient arc of rotation, the cephalic border of the origin of latissimus dorsi muscle was divided, and during this procedure, ninth intercostal vessels were also divided. The thoracodorsal vessels were ligated for 15 minutes before divided to validate sufficient vascular supply of the flap by intercostal arteries. Results: Mild congestion was found on distal portion of the skin island on the next day of operation but improved in two days with conservative management. Stitches were removed in postoperative 3 weeks. The flap was totally viable. Conclusion: The authors reconstructed large soft tissue defect on right flank area successfully with reverse latissimus dorsi myocutaneous flap even though ninth intercostal vessel that partially nourishes the flap was divided. The reverse latissimus dorsi myocutaneous flap can be used for coverage of large soft tissue defects on flank area as well as lower back area.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.273-275
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• 2005

Active thermography is being used since several years for remote non-destructive testing. It provides thermal images for remote detection and imaging of damages. Also, it is based on propagation and reflection of thermal waves which are launched from the surface into the inspected component by absorption of modulated radiation. For energy deposition, it use external heat sources (e.g., halogen lamp or convective heating) or internal heat generation (e.g., microwaves, eddy current, or elastic wave). Among the external heat sources, the ultrasound is generally used for energy deposition because of defect selective heating up. The heat source generating a thermal wave is provided by the defect itself due to the attenuation of amplitude modulated ultrasound. A defect causes locally enhanced losses and consequently selective heating up. Therefore amplitude modulation of the injected ultrasonic wave turns a defect into a thermal wave transmitter whose signal is detected at the surface by thermal infrared camera. This way ultrasound thermography(UT) allows for selective defect detection which enhances the probability of defect detection in the presence of complicated intact structures. In this paper the applicability of UT for fast defect detection is described. Examples are presented showing the detection of defects in PCB material. Measurements were performed on various kinds of typical defects in PCB materials (both Cu metal and non-metal epoxy). The obtained thermal image reveals area of defect in row of thick epoxy material and PCB.