• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.3
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• pp.195-201
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• 2016

Eddy current testing (ECT) is commonly applied for the inspection of automated production lines of metallic products, because it has a high inspection speed and a reasonable price. When ECT is applied for the inspection of a metallic object having an uneven target surface, such as the spline gear of a spline shaft, it is difficult to distinguish between the original signal obtained from the sensor and the signal generated by a defect because of the relatively large surface signals having similar frequency distributions. To facilitate the detection of defect signals from the spline gear, implementation of high-order filters is essential, so that the fault signals can be distinguished from the surrounding noise signals, and simultaneously, the pass-band of the filter can be adjusted according to the status of each production line and the object to be inspected. We will examine the infinite impulse filters (IIR filters) available for implementing an advanced filter for ECT, and attempt to detect the flaw signals through optimization of system design parameters for detecting the signals at the system level.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1204-1208
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• 2000

Objectives : At the closure of the transsphenoidal approach(TSA), the proper sellar floor reconstruction plays an important role in preventing postoperative complications. The septal cartilage, perpendicular plate of nasal septum, and the sphenoid sinus bone are usually used to repair the sellar floor as a bone splint. The authors evaluate the usefulness of a silicone plate as a substitute for bone splint to close a defect of the sellar floor. Materials and Methods : A silicone plate was used to repair the sellar floor in 7 patients with sellar lesions which included four pituitary adenomas, two Rathke's cleft cysts and one metastatic tumor. Among seven cases, five cases underwent a standard TSAs and two received a extended TSAs. The trajectories of the approach were sublabial in four cases and endonasal routes in three cases. The silicone plate for implantation was cut to a size of slightly larger than that of bone window and inserted with a three-pronged fork, and then adjusted precisely. Results : In six patients, there were no complications which related to sellar floor reconstruction. A postoperative cerebrospinal fluid(CSF) rhinorrhea was observed in one patient with pituitary macroadenoma. Conclusions : From the authors' experience, the advantages of the silicone plate are its simplicity of molding to fit any size of sellar floor defects, and easy detection of previously created bone window at reoperation.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.552-554
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• 2011

Purpose: Though its general usage, traditional tie-over dressing using suture has a few drawbacks such as difficulty in re-fixation after its opening especially when hematoma or seroma has occurred. It is rather difficult to maintain a stable dressing on curvy parts of body like flank, buttocks and that leads to unsatisfactory results of the surgery. Authors recommend a quick and repeatedly doable method, tie-over dressing that incorporates the usage of hooks and rubber bands. Methods: Debridement was done at a recipient site to be able to do skin graft. A right size of skin graft was prepared and placed upon the defect site with suture. Enough number of hooks were attached using Blue nylon at the normal skin of the edge of grafted area. We Applied dressing with ointment and fluffy gauze then fixed the dressing by attaching a rubber band at the hook to give a certain amount of tension. One or two days after the surgery, we opened the tie-over dressing and repeated the tie-over dressing by reusing the hooks and rubber band. Results: The skin grafts were all successfully taken and by repeating tie-over dressing using hooks and rubber, we could take the advantage of shortened the dressing time and eliminate the inconvenience of the patient and the surgeon by using bandages and fixing tapes. Conclusion: The advantage of tie over dressing using hooks and rubber bsnds are its easy re-doability early detection of probable complications, preventability of reoccurence of hematoma and seroma. Therefore, authors report this as considering the tie-over dressing using hooks and rubber bands is recommendable.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.312-315
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• 2008

Purpose: Amelanotic melanoma represents a melanoma with an absence or a small number of melanin pigments and comprises 2% of all melanomas. These melanomas are frequently misdiagnosed, probably because of its nonspecific clinical features and difficulty in diagnosis, resulting in delayed diagnosis and treatment. We report a patient with amelanotic melanoma, who underwent surgical treatment with sentinel lymph node biopsy using gamma probe. Methods: A 32-year-old female was presented with a slowly growing ill-defined, hypopigmented nonerythematous lesion with nail defect on right index finger tip. Preoperative punch biopsy was performed, showing an amelanotic melanoma. Sentinel lymph node biopsy was done using gamma probe(Crystal probe system, CRYSTAL PHOTONICS GmbH, Germany) and confirmed no evidence of regional lymph node metastases. The patient underwent amputation at the proximal interphalangeal joint. Results: Histopathologic findings showed superficial spreading melanoma. There were no melanin pigments in Hematoxylin & Eosin stain but positive immunohistochemical stainings for S-100 protein and Hmb45, which were consistent with amelanotic melanoma. Patient's postoperative course was uneventful without any complication and had no evidence of recurrence of tumor in 6 months follow-up period. Conclusion: Amelanotic melanoma is extremely rare subtype of malignant melanoma with histopathologic findings of atypical melanocytes without melanin pigments. Early detection is crucial since survival is strongly related to tumor thickness and tissue invasion at the time of diagnosis. Wide excision is the treatment of choice and other conjunctive therapy has not been successful.

• Design & Manufacturing
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• v.14 no.2
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• pp.21-27
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• 2020

Recently, LCD (Liquid Crystal Display) has been replaced by OLDE (Organic Light Emitting Diode) in high resolution display industry. In the process of OLDE production, it inspects defective products by sending a signal using a probe during OLED panel inspection. At this time, the cause of the detection of failure is divided into two. One is the self-defect of the OLED panel and the other is the poor contact occurring in the process of contact between the two. The second case is unknown at the time of testing, which increases the time for retesting. To this end, we made a system that can identify in real time whether the probe is in contact during the inspection. A contact probe unit was designed for the system, and a stage system was implemented. An inspection system was constructed through S / W and circuit configuration for actual inspection. Finally, a system that can check contact and non-contact in real time was constructed.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.190-200
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• 2014

The video-based system of the broadcasters and the video-related institutions have shifted from analogical to digital in worldwide. This migration process can generate a defect, digital dropout, in the quality of the contents. Moreover, there are limited researches focused on these kind of defects and those related have limitations. For that reason, we are proposing a new method for feature extraction emphasizing in the peculiar block pattern of digital dropout based on discrete cosine transform (DCT). For classification of error block, we utilize support vector machine (SVM) which can manage feature vectors efficiently. Further, the proposed method overcome the limitation of the previous one using continuity of frame by frame. It is using only the information of a single frame and works better even in the presence of fast moving objects, without the necessity of specific model or parameter estimation. Therefore, this approach is capable of detecting digital dropout only with minimal complexity.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.2
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• pp.194-201
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• 2020

Recently, Type 2 high-pressure hydrogen storage tank is studied due to fast defect detection, easy manufacturing, and cost efficiency. Moreover, the dry winding a high-strength metal wire will make increased economic efficiency compare with the wet winding method and the carbon/glass fiber winding method. In this study, a theoretical study on the dry winding of a Type 2 high pressure hydrogen tank using a metal wire was done, and the equations of the total stress on the aligned and the staggered winding for the hoop winding were derived, and the following results were obtained by using these equations. As the diameter of the metal wire, the number of winding layers, and the outer diameter of the liner increase, the maximum stress decreases, but the difference between the maximum stress occurring in the aligned winding and the staggered winding increases. As the pressure increases, the thickness of the winding layer increases, but as the strength of the metal wire increases, the thickness of the winding layer decreases. In addition, regardless of the strength of the metal wire, the thickness of the winding layer of the staggered winding was about 13.4% thinner than that of the aligned winding.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2797-2801
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• 2023

CdZnTeSe (CZTS) has attracted attention for applications in X- and gamma-ray detectors owing to its improved properties compared to those of CdZnTe (CZT). In this study, we grew and processed single crystals of CZT and CZTS using the Bridgeman method to confirm the feasibility of using a dosimeter for high-energy X-rays in radiotherapy. We evaluated their linearity and precision using the coefficient of determination (R²) and relative standard deviation (RSD). CZTS showed sufficient RSD values lower than 1.5% of the standard for X-ray dosimetry, whereas CZT's RSD values increased dramatically under some conditions. CZTS exhibited an R² value of 0.9968 at 500 V/cm, whereas CZT has an R² value of 0.9373 under the same conditions. The X-ray response of CZTS maintains its pulse shape at various dose rates, and its properties are improved by adding selenium to the CdTe matrix to lower the defect density and sub-grain boundaries. Thus, we validated that CZTS shows a better response than CZT to high-energy X-rays used for radiotherapy. Further, the applicability of an onboard imager, a high-energy X-ray (>6 MV) image, is presented. The proposed methodology and results can guide future advances in X-ray dose detection.

• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.188-195
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• 2000

Objective : Essential tremor(ET) is the most common movement disorder, however, there has been little agreement in the neurologic literature regarding diagnostic criteria for ET. Familial ET is an autosomal dominant disorder presenting as an isolated postural tremor. The main feature of ET is postural tremor of the arms with later involvement of the head, voice, or legs. In previous studies, it was reported that ET susceptibility was inherited in an autosomal dominant inheritance. As previous results, it would suggest that ET might be associated with defect of mitochondrial or nuclear DNA. Recent studies are focusing on molecular genetic detection of movement disorders, such as essential tremor and restless legs syndrome. Moreover, authors have analysed mitochondrial DNA(mtDNA) from the blood cell of positive control(PC) and ET patients via long and accurate polymerase chain reaction(LA PCR). Materials & Methods : Blood samples were collected from PC and 9 ET patients. Total DNA was extracted twice with phenol followed by chloroform : isoamylalcohol. For the analysis of mtDNA, LA PCR was performed by mitochondrial specific primers. Results : With this technique, deletions of large quantities were detected within several regions of mtDNA in ET patients except for D-loop and CO I regions. Conclusion : The authors believe that ET is a genentic disorder with deficiency of mitochondrial DNA multicomplexes and mitochondiral dysfunction could be one of major causative factors of ET. Mitochondrial dysfunction may play an important role in the pathogenesis and possibility of disease progression among familial group with ET patients.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.136-146
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• 1996

Studies on normal human embryos and on malformed human hearts have been two main sources of the information on the developmental cardiology, Recent advances in the biological technology has opened a new era and descriptive embryology is being shifted into dynamic developmental biology. In this review, we discuss the current understanding on the cardiac embryology relevant to clinical practices of pediatric cardiology. Classical cardiac embryology starts with understanding on five segments of a straight heart tube : the sinus venosus, the primitive atria, the embryonic left ventricle, the embryonic right ventricle and the truncus arteriosus. Key steps in the normal morphogenetic process are the complex spiral septation of ventriculoarterial junction and two jumping connections : between the embryonic right atrium and embryonic right ventricle, and between the embryonic left ventricle and the aorta. Only after these two steps are successfully completed, the third fetal stage tak s place, when myocardial growth and remodeling take place There are two outstanding progresses on the cardiac embryology during recent five-year period. One is immunohistochemical mapping of the conduction system in the developing heart and the other is the understanding on the neural crest cell migration followed by molecular detection of the microdeletion of chromosome 22. A balanced progress of classical morphological studies, modern biological technics and advanced clinical medicine is an urgent task for doctors and scientists dealing with children with sick hearts.