• Journal of Chest Surgery
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• v.49 no.4
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• pp.264-272
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• 2016

Background: We analyzed the long-term results of ascending aortic replacement and arch aortic replacement in acute DeBakey type I aortic dissections to measure the differences in the distal aortic changes with extension of the aortic replacement. Methods: We reviewed 142 cases of acute DeBakey type I aortic dissections (1996-2015). Seventy percent of the cases were ascending aortic replacements, and 3 0% of the cases underwent total arch aortic replacement, which includes the aorta from the root to the beginning of the descending aorta with the 3 arch branches. Fourteen percent (20 cases) resulted in surgical mortality and 86% of cases that survived had a mean follow-up period of $6.6{\pm}4.6years$. Among these cases, 64% of the patients were followed up with computed tomography (CT) angiograms with the duration of the final CT check period of $4.9{\pm}2.9years$. Results: There were 15 cases of reoperation in 13 patients. Of these 15 cases, 13 cases were in the ascending aortic replacement group and 2 cases were in the total arch aortic replacement group. Late mortality occurred in 13 cases; 10 cases were in the ascending aortic replacement group and 3 cases were in the total arch aortic replacement group. Eight patients died of a distal aortic problem in the ascending aortic replacement group, and 1 patient died of distal aortic rupture in the total arch aortic replacement group. The follow-up CT angiogram showed that 69.8% of the ascending aortic replacement group and 35.7% of the total arch aortic replacement group developed distal aortic dilatation (p=0.0022). Conclusion: The total arch aortic replacement procedure developed fewer distal remnant aortic problems from dilatation than the ascending aortic replacement procedure in acute type I aortic dissections.

• Journal of Chest Surgery
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• v.26 no.12
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• pp.926-933
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• 1993

We experienced 20 patients with Takayasu`s disease who required 22 surgical procedures for critical arterial stenoses, aneurym of descending thoracic aorta, and aortic regurgitation from 1986 to 1993.Five patients had type I arteritis, seven patients had type II , seven patients had type III, and one patients had type IV.15 patients were female and 5 patients were male.Patients` ages ranged from 17 to 47 years and mean age was 29.1 years. The surgical procedures were as follows;autotransplantations of kidney[3], aortic valve replacements[2], ascending aorta-bilateral internal carotid artery bypasses[2], unilateral renal artery bypasses[2], bilateral renal artery bypasses[3], replacement of descending thoracic aorta[1], ascending aorta-abdominal aorta bypass[1], ascending aorta-right internal carotid artery bypass[1], ascending aorta-right internal carotid artery and left subclavian artery bypass[1], left common carotid artery-left-subclavian artery bypass[1], pulmonary artery angioplasty[1], left femoro-bilateral axillary bypass[1] and others[2]. There was no hospital death.Mean duration of follow-up was 42.7 months[ranged from 3 to 96 months].There was one late death and late mortality rate is 5.9%.Two patients was underwent second vascular procedures, one after 5 years and the other after 5 months.The other patients have done well after surgery.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.381-390
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• 2001

This is to evaluate the ascending capacity of migratory fish in the pool and weir type fishways. Ascending environment of the migratory fish in rivers is analyzed through eco-hydraulic experiments using sweetfish, Plecoglossus altivelis, trout, Oncorhnchus mykiss, and surveying the fall height of existing pool and weir type fishways. When the fall height is less than 16.0cm, the ascending capacity of sweetfish in the pool and weir type fishways is greater than trout. On the other hand when the fall height is over 20.0 cm, the ascending capacity of trout is greater than sweetfish. A sweetfish may prefer to jump for upward moving than trout. And its endurance after upward jumping over wear is greater than that of sweetfish. Because of high fall height of existing pool and weir type fishways the migratory environment in rivers is so poor. When the pool and weir type fishways are designed and constructed in river the fall height of weir must be considered for the variety of migratory fish living in river and the fall height of weir less than 20.0cm is suggested.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.3
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• pp.50-61
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• 2007

The purpose of this study is to establish design guidelines for waterscape facilities of healing gardens in psychiatric hospitals. Data were collected through simulation and interview. The subjects included schizophrenic (n=42) and alcoholic (n=41) inpatients as well as medical staff personnel (n=40) at Maeumsarang Hospital. The results of this study are as follows: It was revealed that for all three groups the first preference was a natural flowing waterscape, and the second preference was a natural descending waterscape. The schizophrenic subjects had a greater preference for a static artificial waterscape and a descending artificial multistory waterscape than the other two groups. The alcoholic subjects preferred an ascending natural multistory waterscape. The analysis on the preference towards an ascending type and a descending type from the perspective of naturalness and complexity. Complexity had a greater influence than naturalness in the ascending waterscapes, and naturalness had more influence than complexity in the descending style waterscapes. Therefore, these factors need to be taken into consideration when designing either ascending or descending waterscape facilities. In general, the subjects preferred natural, dynamic and descending waterscapes to the artificial, static and ascending variety.

• Nuclear Engineering and Technology
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• v.33 no.4
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• pp.397-408
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• 2001

A marine reactor shows very different thermal-hydraulic characteristics compared to a land- based reactor. Especially, study on the variation of flow field due to ship motions such as inclination, heaving and rolling is essential since the flow variation has great influence on the reactor cooling capability. In this study, the natural circulation characteristics of integral type marine reactor with modular steam generators were analyzed using computational fluid dynamics code, CFX-4, for inclined conditions. The numerical analyses are performed using the results of natural circulation experiments for integral reactor which are already conducted at Seoul National University. From the results, it was found that the flow rate in the ascending steam generator cassettes increases due to buoyancy effect. Due to this flow variation, temperature difference occurs at the outlets of the each steam generator cassettes. which is mitigated through downcomer by thermal mixing. Also, around the upper pressure header the flow from descending hot leg goes up to the ascending steam generator cassettes due to large natural circulation driving force in ascending steam generator cassettes. From this result, the increase of How rate in the ascending steam generator cassettes could be understood qualitatively.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.289-302
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• 2017

During the research period, error analysis of the amount of daily precipitation was performed with data obtained from 2DVD, Parsivel, and AWS, and from the results, 79 days were selected as research days. According to the results of a synoptic meteorological analysis, these days were classified into 'LP type, CF type, HE type, and TY type'. The dates showing the maximum daily precipitation amount and precipitation intensity were 'HE type and CF type', which were found to be attributed to atmospheric instability causing strong ascending flow, and leading to strong precipitation events. Of the 79 days, most days were found to be of the LP type. On July 27, 2011 the daily precipitation amount in the Korean Peninsula reached over 80 mm (HE type). The leading edge of the Northern Pacific high pressure was located over the Korean Peninsula with unstable atmospheric conditions and inflow of air with high temperature and high humidity caused ascending flow, 120 mm/h with an average precipitation intensity of over 9.57 mm/h. Considering these characteristics, precipitation in these sample dates could be classified into the convective rain type. The results of a precipitation scale distribution analysis showed that most precipitation were between 0.4-5.0 mm, and 'Rain' size precipitation was observed in most areas. On July 9, 2011, the daily precipitation amount was recorded to be over 80 mm (CF type) at the rainy season front (Jangma front) spreading across the middle Korean Peninsular. Inflow of air with high temperature and high humidity created unstable atmospheric conditions under which strong ascending air currents formed and led to convective rain type precipitation.

• 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.

• Journal of Chest Surgery
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• v.29 no.3
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• pp.297-302
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• 1996

From January 1989 to July 1995, 18 patients underwent aortic repair for type A dissections. The e were 9 male and 9 female patients aged 41 to 68 years(mean, 53.8). Thirteen patients underwent the procedure during the acute period, and 5 during the chronic period. During repair of acute dissection, procedures included graft replacement of the ascending aorta only (6 patients), ascending aorta plus partial aortic arch (3), ascending aorta plus total aortic arch (2), Bentall's operation (1), and Bentall's operation plus total aortic arch (1). During repair of chronic dissection, procedures included Bentall's operation (3 patients), ascending aorta only (1), and ascending aorta plus partial aortic arch (1). During repair of the arch, antegrade cerebral perfusion was applied in 4 patients and hypothermic circulatory arrest in 3 patients. There were 4 operative deaths(22.2%), 2 of hemorrhage. and 2 of left ventricular failure in the operating room. Follow-up has been 100% completed and ranged from 2 to 53 months (mean, 17 months). One late death resulted from sepsis following secon operation. Thirteen of the survivors are doing well.

• Journal of Chest Surgery
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• v.50 no.4
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• pp.270-274
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• 2017

Background: We evaluated the operative outcomes of an extra-anatomic bypass from the ascending aorta to the abdominal aorta in patients with type II or III Takayasu arteritis (TA) with mid-aortic syndrome. Methods: From 1988 to 2014, 8 patients with type II (n=2) or III (n=6) TA underwent an ascending aorta to abdominal aorta bypass. The mean patient age was $43.5{\pm}12.2years$ and the mean peak pressure gradient between the upper and lower extremities was $54.8{\pm}39.0mm\;Hg$. The median follow-up duration was 54.4 months (range, 17.8 to 177.4 months). Results: There were no cases of operative mortality. The mean peak pressure gradient significantly decreased to $-2.4{\pm}32.3mm\;Hg$ (p=0.017 compared to the preoperative value). Late death occurred in 2 patients. The symptoms of upper extremity hypertension and claudication improved in all patients. The bypass grafts were patent at $47.1{\pm}58.9months$ in 7 patients who underwent follow-up imaging studies. Conclusion: An extra-anatomic ascending aorta to abdominal aorta bypass could be an effective treatment option for severe aortic steno-occlusive disease in patients with type II or III TA, with favorable early and long-term outcomes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.697-698
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• 2012