• Journal of Chest Surgery
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• v.57 no.1
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• pp.99-102
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• 2024

This article presents a straightforward hybrid arch technique for treating residual type B aortic dissecting aneurysms following type A repair (replacement of the ascending aorta) that employs a frozen elephant trunk (FET) straight vascular prosthesis. The debranch-first method involves only cutting and sewing the previous ascending graft, inserting the FET from zone 0, and debranching the arch vessels using a trifurcated graft. This technique is less invasive as it eliminates the need to manipulate the dissected distal arch aneurysm. We successfully applied this technique to 3 patients, with no instances of in-hospital death, stroke, or paraplegia. The debranch-first technique, combined with zone-0 FET insertion, simplifies the redo repair of residual type B aortic dissection.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.709-714
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• 1997

Recently, the repair materials for defected RC structures are being developed and the performance on repaired RC structures are being studied. This experiment is aimed to evaluate the flexural performance of the RC beams repaired by premix-type materials. The parameters used in this study is the repair materials, the repair length and the treatment of interface. Flexural capacity of repaired RC beams except the polymer-repaired RC beams are similar to that of the control beam. In the flexural capacity, the RC beams treated with chipping show better results than the RC beam without chipping. The various repair lengths of the repaired RC beam are not affected to the flexural capacity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.117-118
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• 2014

The unfloored space and floor is one of characteristic of traditional house in Korea. This space is used to connecting passage between room or entrance of house. Currently, according to decline of heat insulation property thereby becoming decrepit house, native is repairing it for block external environment such as rain, wind and so on. But, variety problem is happening from wrong repair. This object of this study is current status and analysis on problem of unfloored space and floor repair. As a result, current status of repair is classified repair type, installation position and using form. And position of problem is confirmed connection between original house and extend space.

• Architectural research
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• v.7 no.2
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• pp.81-89
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• 2005

Over the years, existing bridges have had various degrees of maintenance to extend the service life. As the existing bridges continue to deteriorate, however, each Department of Transportation (DOT) of the United States of America faces increasing demands on the limited funds available for bridge maintenance. Therefore, it is very important for State Department of Transportations to establish Maintenance, Repair, and Rehabilitation (MR&R) strategies for bridge structures such that funds get allocated for appropriate maintenance over the service life. This paper identifies the state-of-art and the state-of-practice of MR&R actions and the use of MR&R strategies in concrete bridge decks. In addition, a questionnaire survey was conducted to identify the type and timing for MR&R actions as well as existing MR&R strategies taken in concrete bridge deck by each DOT. This paper also presents the results of the survey.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.686-691
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• 2005

We are concerned with the question of servicing warranties for repairable items. During the warranty period, each time an item fails the manufacturer has the obligation to restore the item to operational condition either by repairing the item or by replacing it by a new item. In this paper, we consider the repair-replacement strategies based on the condition of the failed item. For products with phase-type lifetime distributions where the phases represent the condition of the item, we develop algorithms to determine the expected cost of servicing a warranty and use it in making the repair-replacement decision. Illustrative numerical examples are presented. We also propose a dynamic strategy by taking the expected remaining warranty cost into consideration.

• International Journal of Concrete Structures and Materials
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• v.2 no.2
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• pp.107-113
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• 2008

The last 10 years have seen considerable growth in the use of proprietary and special repair cements for concrete pavements in the state of Oklahoma. Many of these products lend themselves to "fast track" construction techniques that allow reopening to traffic within 12 hours or less. These products achieve high early strengths by accelerating the Portland cement hydration process for both Type I and Type III cements. In this paper, the important features of a durable repair which include strength, compatibility and bond or adhesion are first discussed. Then the development, testing and field implementation of the aforementioned materials are discussed including the learning curve required to implement a repair system, not just install a new material. Some of the materials discussed, while expensive on a cost per unit basis, hold great promise for economical use on fast track project.

• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.87-91
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• 2006

Since water leakage and cracks are not the source of serious problems such as long-term lowering of performance and durability of a stricture, including damages to operating facilities of a structure, damages to internal finishing materials, exhibition, and goods, and pollution of residential environment, they might have led to development of positive coping skills; however, an instant loss of lives or property due to earthquake, explosion, typhoon, or a fire was indeed neglected. In these days, repair materials for leakage cannot help but being taken in temporary way without any noticeable countermeasure. This kind of repair is socially criticized many times that is defective construction even if this costs a lot. It was not arrange the standard for construction methods of sealer of injection type for leakage maintenance, even it has been used various type of construction methods for leakage part. In conclusion, we suggest that the construction methods of sealer of injection type for leakage maintenance for leakage to establish the leakage repairing technology as increase of structure demand. Therefore, it would be possible to provide a stage-by-stage solution by developing systematic research activities among the industry, schools, and research institutes to spread maintenance management techniques globally through technical solution to water leakage and cracks, acquisition of structural safety with prolonged durability for life cycle, reduction of water leakage repair expense s, and so on.

• Journal of Chest Surgery
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• v.48 no.4
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• pp.238-245
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• 2015

Background: Some patients show favorable changes in the descending aortic false lumen after conventional repair of acute type A dissection, although the incidence of favorable changes has been reported to be low. We aimed to investigate the incidence of positive postoperative changes in the false lumen and the factors associated with positive outcomes. Methods: In 63 patients who underwent surgery for type A acute dissection as well as serial computed tomography (CT) scanning, morphological parameters were compared between the preoperative, early postoperative (mean interval, 5.4 days), and late CT scans (mean interval, 31.0 months) at three levels of the descending thoracic aorta. Results: In the early postoperative CT images, complete false lumen thrombosis and/or true lumen expansion at the proximal descending aorta was observed in 46% of the patients. In the late images, complete thrombosis or resolution of the proximal descending false lumen occurred in 42.9% of the patients. Multivariate analysis found that juxta-anastomotic false lumen thrombosis was predictive of favorable early changes, which were in turn predictive of continuing later improvement. Conclusion: Even after conventional repair without inserting a frozen elephant trunk, the proximal descending aortic false lumen showed positive remodeling in a substantial number of patients. We believe that the long-term prognosis of type A dissection can be improved by refining surgical technique, and particularly by avoiding large intimal tears at the anastomosis site during the initial repair.

• Advances in pediatric surgery
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• v.14 no.1
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• pp.21-26
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• 2008

There is significant morbidity and mortality associated with the combination of esophageal atresia (EA) and duodenal atresia (DA). Nevertheless, the management protocol for the combined anomalies is not well defined. The aim of this study is to review our experience with the combined anomalies of EA and DA. From May 1989 to August 2006, seven neonates were diagnosed as EA with DA at Asan Medical Center. In all cases, the type of EA was proximal EA and distal tracheoesophageal fistula (TEF). The diagnosis of DA was made in theprenatal period in 1, at birth in 4, 4 days after birth in 1 (2 days after EA repair) and at postmortem autopsy in 1. Except the one case where DA was missed initially, primary simultaneous repair was attempted. DA repair with gastrostomy followed by EA repair in 2, EA repair followed by DA repair without gastrostomy in 2, and TEF ligation followed by DA repair with gastrostomy in 1. There were two deaths. One baby had a large posterolateral diaphragmatic hernia, and operative repair was not attempted. The other infant who had a TEF ligation and DA repair with gastrostomy expired from cardiac failure due to a large patent ductus arteriosus. Simultaneous repair of EA and DA appears to be an acceptable management approach for the combined anomalies, but more experience would be required for the selection of the primary repair of both anomalies.

• Journal of the Korean Data and Information Science Society
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• v.14 no.2
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• pp.393-403
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• 2003

In this paper, various replacement policies for the general failure model are considered. There are two types of failure in the general failure model. One is Type I failure (minor failure) which can be removed by a minimal repair and the other is Type II failure (catastrophic failure) which can be removed only by a complete repair. In this model, when the unit fails at its age t, Type I failure occurs with probability 1-p(t) and Type II failure occurs with probability p(t), $0{\leq}p(t){\leq}1$. Under the model, optimal replacement policies for the long-run average cost rate and the limiting efficiency are considered. Also taking the cost and the efficiency into consideration at the same time, the properties of the optimal policies under the Cost-Priority-Criterion and the Efficiency-Priority-Criterion are obtained.