• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.2956-2958
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• 1999

The classical solution to the noise removal problem is the Wiener filter, which utilizes the second-order statistics of the Fourier decomposition. We discuss a Bayesian formalism which gives rise to a type of wavelet threshold estimation in non-parametric regression. A prior distribution is imposed on the wavelet coefficients of the unknown response function, designed to capture the sparseness of wavelet expansion common to most application. For the prior specified, the posterior median yields a thresholding procedure

• Journal of Chest Surgery
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• 제28권7호
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• pp.717-720
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• 1995

The bronchopleural fistula is the most common and serious complication of postpneumonectomy empyema. We experienced one case of postpneumonectomy empyema with bronchopleural fistula which treated with Abruzzini operation using residual long bronchial stump. Median sternotomy was used with extension about 3cm incision toward cephalic side. We ligated and divided the innominate vein. We did not open the pericardium with extrapericardial approach. Stapler was used to distal bronchial side and additional interupt sutures were used on proximal side.

• Journal of Chest Surgery
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• 제47권1호
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• pp.1-5
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• 2014

Background: Recently, a hybrid surgical-electrophysiological (EP) approach for confirming ablation lines in patients with atrial fibrillation (AF) was suggested. The aim of this approach was to overcome the limitations of current surgery- and catheter-based techniques to yield better outcomes. Methods: Ten consecutive patients with AF underwent total thoracoscopic ablation (TTA) following transvenous catheter EP ablation (residual gap and cavotricuspid isthmus [CTI] ablation). Holter monitoring was performed 6 months postoperatively. Results: Ten patients (90% with persistent AF) underwent successful hybrid procedures, and there was no in-hospital mortality. An EP study was performed in 8 patients and showed that successful antral ablation in all pulmonary veins was achieved in 7 of them. The median follow-up duration was 7.63 months (range, 6.7 to 11.6 months). Nine patients underwent Holter monitoring 6 months postoperatively, and the results indicated an underlying sinus rhythm without AF, atrial flutter, or atrial tachycardia lasting more than 30 seconds in all of the patients. There was no recurrence of AF during follow-up. Conclusion: A hybrid approach that consists of TTA followed by transvenous catheter EP ablation (residual gap and CTI ablation) yielded excellent outcomes in our patient population. A hybrid approach should be considered in patients with a high risk of AF recurrence.

• 한국통신학회논문지
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• 제21권7호
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• pp.1696-1705
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• 1996

중앙값여파기의 일반화된 형태인 스택여파기의 이론을 써서 잡음으로 왜곡된 영상에서의 윤곽선 검출기를 연구하였다. 이 논문에서 제안된 추정값 차이기법(difference of estimates:DoE)은 충격성 잡음의 환경에서 매우 효율적인 기법으로 기존의 형태학적 접근 방법을 개선하였다고 할 수 있다. 이 기법에서는 잡음이 있는 영상에 스택필터를 사용하여 잡음이 없는 원영상의 불림 영상(diated version)과 녹임 영상(eroded version)을 최적으로 추정한다. 그 결과로 얻어진 추정 영상의 차이에 적절한 문턱값 연산을 적용하여 윤곽선을 얻을 수 있다. 이 기법을 써서 얻은 결과는 가산상 정규 잡음의 경우에는 Canny의 기법을 이용하여 얻은 결과와 상응하는 성능을 갖고, 충격성 잡음의 경우에는 훨씬 좋은 성능을 보여준다.

• 산업경영시스템학회지
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• 제28권1호
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• pp.121-128
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• 2005

This paper proposes the heuristic approach for the generalized GT(Group Technology) problem to consider the restrictions which are given the number of cell, maximum number of machines and minimum number of machines. This approach is classified into two stages. In the first stage, we use the similarity coefficient method which is proposed and calculate the similarity values about each pair of all machines and align these values in descending order. If two machines which is selected is possible to link the each other on the edge of machine cell and they don't have zero similarity value, then we assign the machines to the machine cell. In the second stage, it is the course to form part families using proposed grouping efficacy. Finally, machine-part incidence matrix is realigned to block diagonal structure. The results of using the proposed approach are compared to the Modified p-median model.

• International Journal of Reliability and Applications
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• 제5권4호
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• pp.129-145
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• 2004

We use a novel, forced censoring technique that closer fits the lower tails of strenth distributions to better estimate extremly smaller percentiles for measuring progress in continuous improvement initiatives. These percentiles are of greater interest for companies, government oversight organizations, and consumers concerned with safely and preventing accidents for many products in general, but specifically for medium density fiberboard (MDF). The international industrial standard for MDF for measuring highest quality is internal bond (IB, also called tensile strengh) and its smaller percentiles are crucial, especially the first percentile and lower ones. We induce censoring at a value just above the median to weight lower observations more. Using this approach, we have better fits in the lower tails of the distribution, where these samller percentiles are impacted most. Finally, bootstrap estimates of the small percentiles are used to demonstrate improved intervals by our forced censoring approach and the fitted model. There was evidence from the study to suggest that MDF has potentially different failure modes for early failures. Overall, our approach is parsimonious and is suitable for real time manufacturing settings. The approach works for either strengths distributions or lifetime distributions.

• Journal of Chest Surgery
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• 제56권3호
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• pp.171-176
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• 2023

Background: This study analyzed and described the clinical characteristics and surgical outcomes of diaphragmatic hernia (DH) repair according to the operative approach. Methods: After excluding cases with a combined approach and hiatal hernias, we analyzed 26 patients who underwent DH repair between 1994 and 2018. The baseline and perioperative characteristics of the thoracic approach group and the abdominal approach group were described and analyzed. Results: Fifteen of the 26 patients were treated through the thoracic approach, including 5 patients who underwent video-assisted thoracic surgery (VATS). Eleven patients underwent the abdominal approach. The thoracic approach was associated with a longer duration of DH than the abdominal approach (2 vs. 0.1 months), herniation of the right-sided abdominal organs, and herniation of the retroperitoneal organs. During the median follow-up of 23 months, there was no recurrence of DH. Conclusion: The surgical approach should be chosen considering the duration of DH and the location of herniated organs. VATS might be a safe and feasible option for repairing DH.

• Journal of Korean Neurosurgical Society
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• 제39권5호
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• pp.366-369
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• 2006

Objective : There are various surgical approaches to far-lateral lesions in the L5-S1 intervertebral space. Of these is the validity of a paramedian tangential approach is being investigated in this study. Methods : A retrospective study was conducted on 25 patients who had been diagnosed as having a far-lateral L5-S1 disc herniations, osteophyte, costal process hypertrophy, and had undergone a paramedian tangential approach from November 1999 through December 2003. The degree of symptoms and improvement were compared via the visual analog pain scale, before and after surgery. Results : This study included 4 males and 21 females with a mean age of $62{\pm}11.8$ years old. The average follow-up period after surgery was $8.2{\pm}2.7$ months. The visual analog pain scale taken before surgery was $6.7{\pm}1.1$ points, while the post-surgical scale was $2.4{\pm}0.9$ points showing a significant degrease [p < 005]. There were no complications that developed during surgery. Conclusion : A paramedian tangential approach is less invasive in the soft tissue than that of the median approach. This approach may effectively reduce nerve root compression and expand intervertebral foramens, and is devoid of the risk of spinal instability after surgery. The authors suppose that a paramedian tangential approach is quite an effective technique to relive compression in the far-lateral L5-S1 intervertebral space.

• Journal of Chest Surgery
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• 제46권3호
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• pp.216-219
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• 2013

There are various methods for approaching the aortic arch, such as median sternotomy or lateral thoracotomy. However, accessing the site of distal anastomosis is problematic when the distal arch is extensively involved. We report a case of extended aortic arch replacement and coronary artery bypass through the L-incision approach.

• Journal of Chest Surgery
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• 제26권12호
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• pp.969-971
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• 1993

The sternal turnover has a limited use in an asymmetrical funnel chest. However we tried `One-half sternal turnover` as a new operative approach for an asymmetrical funnel chest. Through the bilateral submammary skin incision, median sternotomy was made from xiphoid process to midsternum and extended horizontally. The segment of ribs were cut at the angle of depression. The en-bloc resected chest wall segment contained one-half sternum as well as a part of ribs and left half of rectus muscle. After turning over the en-bloc segment, reapproximation with wiring was done. Sternotomy wound was closed in layer after placing of substernal drainage tube. Postoperatively, the chest wall was stable and the recovery course was uneventful except left-sided minimal pneumothorax which was cured spontaneaously. The patient was discharged on postoperative 14th day.