• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.344-349
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• 2012

This paper describes experimental results and their analysis on the new test images, called as the McMaster image dataset, to develop demosaicking techniques. The well-known image dataset for demosaicking is so far the Kodak image dataset. However, different results have been reported, as the new image dataset is engaged in developing demosaicking techniques. Thus, we conduct a series of experiments on both the McMaster dataset and the Kodak dataset; we analyze and compare those experimental results; and we provide the peculiar features of the new dataset. Also, the experimental results and their analysis indicate that the McMaster dataset deserves to be a test image dataset for future demosaicking techniques; thus, we expect they can be utilized as basic data for demosaicking.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.176-179
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• 2004

A 30 year-old female patient was admitted for dizziness and palpitation. Pulsation of the both upper extremities and both common carotid arteries were absent. Innominate artery and both common carotid arteries were severely narrowed and both subclavian arteries were completely obstructed on aortogram. The patient was diagnosed as tvue Ⅰ Takayasu's arteritis, and operation was peformed to increase blood flow to the brain and both upper extremities. Ascending aorta, both carotid arteries, both subclavian arteries, and both axillary arteries were exposed by four separate incision, and we performed an aorto-bicarotid-biaxillary bypass with Hemashield graft. Previous dizziness and palpation were disappeared after the operation.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.520-522
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• 2008

Aortoesophageal fistula that causes massive bleeding from the esophagus is a rare and fatal disease. The most common cause of aortoesophageal fistula is an aortic aneurysm, and the other causes are inflammatory disease and neoplasm. The treatment of choice for aortoesophageal fistula is surgery, and this surgery carries a high rate of mortality and morbidity. Stent-graft treatment is now being applied for this malady. Herein we report on a case of primary aortoesophageal fistula that was treated with primary repair of the fistula openings, and we include a review of the relevant literature.

• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.858-860
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• 2006

Papillary fibroelastoma is the second most common benign cardiac tumor, usually involving the cardiac valve. Papillary fibroelastoma attached at the right coronary cusp of the aortic valve was found in a 51-year-old woman, who was presented with chest pain and dyspnea. During the operation, the tumor mass was excised without causing damage on the aortic valve leaflet.

• Mineral and Industry
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• v.29
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• pp.56-66
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• 2016

In Korea, where hydrothermal alteration zones are widely distributed, clay veins formed by hydrothermal alteration processes on natural slopes or artificial slopes can play an important role in the slope stability. When the surface water infiltrates the ground where the clay vein exists, the pore water pressure in the ground can be locally increased due to impermeable properties of clay minerals. Infiltration of the surface water induces the increase in the pore water pressure, which can cause erosion of the fine clay particles. The eroded clay particles flow and deposit in an area where the flow velocity is slowed down. Where clay minerals are deposited, ground water can leak due to an increase in local pore pressures, which can cause slope failure. In this paper, studies related to hydrothermal clay vein and landslide are introduced.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.2
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• pp.15-21
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• 2009

This paper proposes a novel algorithm to assess the abnormal heart beats such as PVC (Premature Ventricular Contraction) and its subsequent RUNs. Our Arrhythmic detection scheme is based on only the R-R Interval features extracted from ECG waveforms and MIT-BIH arrhythmia database is evaluated to validate the efficiency of our algorithm in terms of sensitivity, specificity, FPR(%) and FNR(%).

• Journal of Chest Surgery
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• v.35 no.6
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• pp.479-482
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• 2002

Aortoesophageal fistula induced by endoesophageal stent is rare; however, it is usually a fatal disorder, with few survivors reported. We report a case of a 32-year old female with aortoesophageal fistula after insertion of the esophageal stent in esophageal lye stricture who was successfully diagnosed with endoscopy and treated in a two-stage operation. In the first stage, we performed esophagectomy, primary repair of the fistula site in the descending thoracic aorta, and feeding gastrostomy. After the patient recovered well postoperatively, a retrosternal interposition of the right colon and cervical esophago-colo-grastostomy were performed, to re-establish the gastrointestinal tract.

• Journal of Chest Surgery
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• v.35 no.4
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• pp.274-282
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• 2002

Background: Paravalvular leakage or false aneurysm developed after isolated aortic valve replacement(AVR) for aortic regurgitation(AR) associated with Behcet's disease is one of the most serious complications, and requires subsequent reoperations. We describe the surgical result of homograft aortic root replacement(ARR) for AR associated with Behcet's disease. Material and Method: From January 1992 to December 2001, 6 patients with AR associated with Behcet's disease underwent 7 ARR with homograft and 1 Ross operation. Five patients were male and one was female. The grafts used for ARR were 5 aortic and 2 pulmonic homografts. Ages at operation ranged from 27 to 51 years(mean, 37$\pm$9 years). Two patients underwent ARR with aortic homograft at the first operation. In the remaining 4 patients, ARR using a homograft was performed for paravalvular leakage that developed after AVR, and the mean interval from AVR to ARR was 21 $\pm$29 months(range, 5 to 73.3 moths, median, 7.6 months). Result: There was no early death. All patients were followed up for an average of 18.9$\pm$24.0 months(range, 1.9 to 68.9 months, median, 8.4 months). Two of 4patients who had undergone ARR after AVR required subsequent reoperations for false aneurysm of the ascending aorta and failure of pulmonary homograft. One patient underwent re-replacement of the aortic root, ascending aorta and partial aortic arch with an aortic homograft, the other underwent Ross operation. Conclusion: This study suggests that aortic root replacement using a homograft in aortic regurgitation with Behcet's disease may provide good clinical results and decrease the incidence of paravalvular leakage or false aneurysm after aortic valve replacement. However, the adequate perioperative management and complete removal of the inflarrunatory tissue at operation were also important for the good long-term results.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.197-203
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• 2005

Homograft aortic valve replacement (AVR) has many advantages such as excellent hemodynamic performance, faster left ventricular hypertrophy regression, resistance to infection and excellent freedom of thromboembolism. To find out the results of homograft AVR, we reviewed our surgical experiences. Material and Method: Eighteen patients (male female=16 : 2, mean age=39.3$\pm$16.2 years, range: 14$\~$68 years) who underwent homo-graft aortic valve replacement between May 1995 and May 2004 were reviewed. The number of homografts was 20 (17 aortic and 3 pulmonic homografts) including two re-operations. Ten patients had a history of previous aortic valve surgery. Indications for the use of a homograft were native valve endocarditis (n=7), prosthetic valve endocarditis (n=5), or Behcet's disease (n=8). The homograft had been implanted predominantly as a full root except in one patient in the subcoronary position. Result: Mean follow-up was 41.3 $\pm$ 26.2 months. There was one operative mortality. Postoperative complications included postoperative bleeding in 3 patients, and wound infection in 1. There was no late death. Three patients underwent redo-AVR. The etiology of the three reoperated patients was Behcet's disease (p=0.025). Freedom from reoperation was $87.5\pm8.3\%$, $78.8\pm11.2\%$ at 1, 5 years respectively, In patients with infective endocarditis, there was no recurrence of endocarditis. There was no thromboembolic complication. Conclusion: Although longer term follow-up with larger numbers of patients is necessary, the operative and mid-term results for homograft AVR was good when we took into account the operative risks of Behcet's disease or infective endocarditis. Behest's disease was a risk factor for reoperation after the homograft AVR. We think homograft AVR is the procedure of choice, particularly in patients with infective endocarditis.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.316-321
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• 2006

Purpose: Differential diagnosis between arteriovenous (AVMs) aud non-arteriovenous malformations (nAVMs) is important in patients with congenital vascular malformations, because AVMs can cause hemodynamic alteration and require immediate treatment. We investigated whether transarterial lung perfusion scintigraphy (TLPS) was useful for the diagnosis and post-therapeutic evaluation of AVMs in extremities. Materials and Methods: Fifty-seven patients (M:F=26:31, $21{\pm}13$ yr, 9 upper and 48 lower extremities) suspected of congenital vascular malformations in extremities underwent TLPS using $^{99m}Tc-MAA$ before embolization/sclerotherapy. Dose-corrected shunt fraction (SF) was calculated from time-activity curve of the lung. Final diagnosis of AVMs was determined by angiography. in patients with AVMs, follow-up TLPS was done for post-therapeutic evaluation. Results: Sixteen patients (8 upper and 8 lower extremities) had AVMs, while the remaining 41 had nAVMs (1 upper and 40 lower extremities). The mean SF of AVMs on TLPS was significantly higher than that of nAVMs ($66.4{\pm}25.8%\;vs.\;2.8{\pm}4.3%$), p=0.003). The sensitivity, specificity, and accuracy of TLPS (cut-off of SF = 20.0%) in diagnosis of AVMs before treatment were 93.8% (15/16), 100% (41/41) and 98.2% (56/57), respectively. The follow-up TLPS and angiography for post-therapeutic evaluation showed concordant results in 13 of 16 patients (81.3%) with AVMs. The mean SF of TLPS was significantly decreased after embolization/sclerotherapy ($69.5{\pm}24.0%\;vs.\;41.0{\pm}34.7%$, p=0.01). Conclusion: TLPS provides hemodynamic information of AVMs in extremities semiquantitatively. Furthermore, the results of TLPS showed a high concordance rate with angiographic findings. Therefore, TLPS is useful for the diagnosis and post-therapeutic evaluation of AVMs in extremities.