• Journal of Welding and Joining
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• v.32 no.5
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• pp.50-57
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• 2014

Friction Stir Welding (FSW) is a complex process with several mutually interdependent parameters. A slight difference from known settings may lead to imperfections in the stirred zone. These inhomogeneities affect on the mechanical properties of the FSWed joints. In order to prevent the failure of the welded joint it is necessary to detect the most critical defects non-destructive. Especially critical defects are wormhole and lack of penetration (LOP), because of the difficulty of detection. Online thermography is used process-accompanying for defect detecting. A thermographic camera with a fixed position relating to the welding tool measures the heating-up and the cool down of the welding process. Lap joints with sound weld seam surfaces are manufactured and monitored. Different methods of evaluation of heat distribution and intensity profiles are introduced. It can be demonstrated, that it is possible to detect wormhole and lack of penetration as well as surface defects by analyzing the welding and the cooling process of friction stir welding by passive online thermography measurement. Effects of these defects on mechanical properties are shown by tensile testing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.90-93
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• 2000

In this study, the rise throughput and the stability in fabrication of device can be obtained by applying of CMP process to STI structure in 0.18um semiconductor device. To employ in STI CMP, the reverse moat process has been added thus the process became complex and the defects were seriously increased. Removal rates of each thin films in STI CMP was not equal hence the devices must to be effected, that is, the damage was occured in the device dimension in the case of excessive CMP process and the nitride film was remained on the device dimension in the case of insufficient CMP process than these defects affect the device characteristics. To resolve these problems, the development of slurry for CMP with high removal rate and high selectivity between each thin films was studied then it can be prevent the reasons of many defects by reasons of many defects by simplification of process that directly apply CMP process to STI structure without the reverse moat pattern process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.112-118
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• 2021

In this study, an inspection method using a color image is proposed to conduct a real-time inspection of covalent organic framework (COF) films to detect defects, if any. The COF film consists of an upper pattern SR and a lower PI. The proposed system detects the defects of more than 20 ㎛ on the SR surface owing to the characteristics of the pattern, whereas on the PI surface, it detects defects of more than 4 ㎛ by utilizing a micro-optical system. In the existing system, it is difficult for the operator to conduct a full inspection through a high-performance microscope. The proposed inspection algorithm performs the inspection by separating each color component using the color contrast of the pattern on the SR side, and on the PI surface it inspects the bonding state of the mounted chip. As a result, it is possible to confirm the exact location of the defects through the SR and PI surface inspections in the implemented inspection.

• Archives of Plastic Surgery
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• v.50 no.5
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• pp.523-528
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• 2023

The Gustilo IIIB tibiofibular fractures often result in long bone loss and extensive soft tissue defects. Reconstruction of these complex wounds is very challenging, especially when it includes long bone grafts, because the donor site is limited. We describe our experience using a set of chimeric ipsilateral vascularized fibula grafts with a thoracodorsal artery perforator free flap to reconstruct the traumatic tibia defects. A 66-year-old male suffered a severe comminuted tibia fracture and segmented fibula fracture with large soft tissue defects as a result of a traffic accident. He also had an open calcaneal fracture with soft tissue defects on the ipsilateral side. All the main vessels of the lower extremity were intact, and the cortical bone defect of the tibia was almost as large as the fractured fibula segment. We used an ipsilateral vascularized fibula graft to reconstruct the tibia and a thoracodorsal artery perforator flap to resurface the soft tissue, using the distal ends of peroneal vessels as named into sequential chimeric flaps. After 3 weeks, the calcaneal defect was reconstructed with second thoracodorsal artery perforator free flap. Reconstruction was successful and allowed rapid rehabilitation because of reduced donor site morbidity.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.122-133
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• 1986

Thirteen patients with cyanotic cardiac malformations having more complex intracardiac defects, hemodynamics and operative procedures than ones in Tetralogy of Fallot undertaken total surgical corrections from July 1981 to August 1985. The cases of corrective surgery for complex cardiac malformations were 3.9% of all congenital cardiac malformations and 12.6% of cyanotic cardiac malformations. Six patients died within 30 days after surgery. So operative mortality was 46%; Transposition of the great arteries, two of 4 patients, due to low cardiac output syndrome and tracheal bleeding ; Univentricular heart, one of 3 patients, due to bleeding; Corrected transposition of the great arteries, one of 2 patients, due to acute heart failure; Tricuspid atresia, one of 2 patients, due to low cardiac output syndrome; Double outlet right ventricle, one of single patient, due to respiratory failure. The cases of surgical correction for complex cardiac malformations are progressively increasing in numbers. The more accurate evaluation of anatomical condition and hemodynamics in preoperative diagnosis, studies on applicable surgical procedure and perioperative care of patients are necessary in the improvement of clinical and surgical results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1086-1103
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• 2020

The automatic identification and classification of image-based weld defects is a difficult task due to the complex texture of the X-ray images of the weld defect. Several depth learning methods for automatically identifying welds were proposed and tested. In this work, four different depth convolutional neural networks were evaluated and compared on the 1631 image set. The concavity, undercut, bar defects, circular defects, unfused defects and incomplete penetration in the weld image 6 different types of defects are classified. Another contribution of this paper is to train a CNN model "RayNet" for the dataset from scratch. In the experiment part, the parameters of convolution operation are compared and analyzed, in which the experimental part performs a comparative analysis of various parameters in the convolution operation, compares the size of the input image, gives the classification results for each defect, and finally shows the partial feature map during feature extraction with the classification accuracy reaching 96.5%, which is 6.6% higher than the classification accuracy of other existing fine-tuned models, and even improves the classification accuracy compared with the traditional image processing methods, and also proves that the model trained from scratch also has a good performance on small-scale data sets. Our proposed method can assist the evaluators in classifying pipeline welding defects.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.382-387
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• 2019

Background: Defects of the nasal ala and tip have a complex three-dimensional structure that makes them challenging to reconstruct. Many reconstructive options have been described for nasal ala and tip defects, ranging from primary closure to local flaps and skin grafts. However, it is difficult to determine which method will yield the best cosmetic results in each individual case. Thus, the purpose of this study was to determine which surgical procedures for reconstructing defects of the nasal ala and tip have better cosmetic results. Methods: From 2008 to 2018, 111 patients underwent surgery to reconstruct skin defects after resection of skin cancer in the nasal ala or tip. Their charts were reviewed to obtain data on age, sex, surgical location, size of the defect, surgical method, and cosmetic results using a visual analog scale (VAS). Results: For nasal ala reconstruction, the most commonly used surgical technique was the nasolabial flap (n= 42). This method also had the highest VAS score (7/10). The most commonly selected surgical method for nasal tip reconstruction was the bilobed flap (n= 13), and bilobed flaps and primary closure had the highest VAS score (7/10). Conclusion: Nasolabial flaps showed excellent cosmetic results for the reconstruction of nasal ala defects, while primary closure and bilobed flaps yielded excellent cosmetic results for the reconstruction of nasal tip defects.

• Archives of Craniofacial Surgery
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• v.19 no.4
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• pp.254-259
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• 2018

Background: The esthetic and functional outcomes of periorbital defect reconstruction are very important because of the complex anatomy and specialized functions of this region. The orbicularis oculi myocutaneous (OOMC) flap is useful for the reconstruction of periorbital defects. But, according to the location and depth of the defects, the reconstruction using OMC flaps with various techniques is rare. The authors have used various kinds of OOMC flaps in various situations and we present an analysis of our experiences. Methods: From November 2001 to July 2017, we used 36 OOMC flaps to reconstruct 30 periorbital defects in 25 patients. We analyzed the cause of the defect, its location, the type of concomitant surgery, the method of flap movement, and complications. Results: Of the 30 defects, basal cell carcinoma was the most common cause, accounting for 20 cases. When the used OOMC flap was classified according to the location of the defects, the switch flap was used in nine cases among 15 defects of lower eyelid, and the V-Y advancement flap was mainly used for other parts. As surgical methods according to the depth of defect were classified, all cases involving the tarsal plate were reconstructed with a composite graft. In case of skin and muscles, they were reconstructed only with OOMC flap or with full-thickness skin graft. Conclusion: The OOMC flap provides good skin quality that is very similar to that of the defect tissue. Depending on the location and depth of the defect, the OOMC flap may be used properly in a variety of ways to achieve good results.

• Transactions of Materials Processing
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• v.9 no.6
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• pp.653-662
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• 2000

Wrinkling is one of the major defects in sheet metal products together with tearing, springback and other geometric and surface defects. The initiation and growth of wrinkles are influenced by many factors such as stress ratios, mechanical properties of the sheet material, geometry of the workpiece, contact condition, etc. It is difficult to analyze the wrinkling initiation and growth considering all the factors because the effects of the factors are very complex and the wrinkling behavior may show a wide scatter of data even for small deviations of factors. The finite element analyses of the wrinkling initiation and growth in the sheet metal forming process provide the detailed information about the wrinkling behavior of sheet metal. The direct analyses of the wrinkling initiation and growth, however, bring about a little difficulty in complex industrial problems because it needs large memory size and long computation time. In the present study, therefore, a global-local analysis technique is introduced for the computational efficiency. Through the analysis of wrinkling in the door inner stamping process, the efficiency of the global-local analysis technique is investigated.

• Archives of Plastic Surgery
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• v.46 no.3
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• pp.255-261
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• 2019

Cross-leg flaps are a useful reconstructive option for complex lower limb defects when free flaps cannot be performed owing to vessel damage. We describe the use of the extended distally based sural artery flap in a cross-leg fashion for lower extremity coverage in three patients. To maximise the viability of these extended flaps, a delay was performed by raising them in a bipedicled fashion before gradual division of the tip over 5 to 7 days for cross-leg transfer. Rigid coupling of the lower limbs with external fixators was critical in preventing flap avulsion and to promote neovascular takeover. The pedicle was gradually divided over the ensuing 7 to 14 days before full flap inset and removal of the external fixators. In all three patients, the flaps survived with no complications and successful coverage of the critical defect was achieved. One patient developed a grade 2 pressure injury on his heel that resolved with conservative dressings. The donor sites and external fixator pin wounds healed well, with no functional morbidity. The cross-leg extended distally based sural artery flap is a reliable reconstructive option in challenging scenarios. Adequate flap delay, manoeuvres to reduce congestion, and postoperative rigid immobilization are key to a successful outcome.