• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2106-2112
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• 2013

In a traditional hydraulic elevator, elevator car is descended by down control valve, and the oil hydraulic energy must be lost during the descending stroke. In this paper, hybrid type energy saving unit for a hydraulic elevator is researched to save the hydraulic energy which is lost during the descending stroke. The energy is stored as converted electrical energy, and the saved energy is reused as the auxiliary power for the ascending stroke of elevator car or the main power of other parts. The results show that the output characteristics are stable and good and the research is successful and useful to reuse the saved energy during the descending stroke of elevator car.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.3
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• pp.207-212
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• 2010

This paper presents a spiral descending path and a landing guidance law for net-recovery of a fixed-wing unmanned aerial vehicle. The net-recovery landing flight is divided into two phases. In the first phase, a spiral descending path is designed from an arbitrary initial position to a final approaching waypoint toward the recovery net. The flight path angle is controlled to be aligned to the approaching direction at the end of the spiral descent. In the second phase, the aircraft is guided from the approaching waypoint to the recovery net using a pseudo pursuit landing guidance law. Six degree-of-freedom simulation is performed to verify the performance of the proposed landing guidance law.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.595-598
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• 1999

Some extensive thoracic aortic aneurysms are not amenable to staged repair, such as extremely large distal aortic aneurysms that are unsuitable for an elephant trunk anastomosis, or aneurysms that are accompanied by complications such as ruptured descending thoracic aneurysm. We report here a case of successful replacement of the aorta from the ascending to the descending aorta in one operation. The patient was 65-year-old man who had an aneurysm which involved the entire thoracic aorta and ruptured in the descending aorta. The operation was performed via transverse thoracosternotomy, and under the deep hypothermic circulatory arrest with retrograde cerebral perfusion. The patient recovered uneventfully and was discharged without any neurologic complications.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.386-389
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• 2004

Descending nectorizing mediastinitis (DNM). represents a virulent form of mediastinal infection requiring prompt diagnosis and treatment to reduce the high morbidity mortality associated with this disease. Intr. avenous broad-spectrum antibiotic therapy alone is not efficient without adequate surgical drainage of the cervical and mediastinal collections, extensive debridement and excision of necrotic tissue, and wide mediastino-pleural irrigation. A 38-year-old man admitted via emergency room with painful left neck swelling and uncontrolled high fever. Chest computed tomogram showed left paratracheal abscess descending into the superior and anterior mediastinum. Transcervical mediastinal drainage was performed with 26 Fr. chest tube and left paratracheal drainage was performed with Penrose drain in urgency. Culture and sensitivity test grew Yeast. The drains removed via gradually shortening on day 39 after surgery.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.78-83
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• 2000

In this study, CT specimens were prepared from AST SA516 Gr. 70 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at 25$^{\circ}C $, -60$^{\circ}C $, -80$^{\circ}C $ and -100$^{\circ}C $ and in the range of stress ratio of 0.05, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\delta} K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\delta $K in the stable of fatigue crack growth (Region II) were increased in proportion to descending temperature. It was assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN -$\delta $K in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate da/dN is rapid in proportion to descending temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.842-846
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• 2002

A rare case of acute descending necrotizing mediastinitis(DNM) secondary to spontaneous rupture of hypopharynx is reported. Due to the right lower cervical abscess the patient had undertaken limited right anterior cervical drainage at other department. After transferring to our department he undertook combined wide cervical mediastinal drainage and mediastinal drainage via right thoracotomy. However mediastinal drainage was ineffective. So the second operation was performed and chest tubes were relocated. He had an uneventful postoperative course. As far as the cause of acute descending necrotizing mediastinitis was concerned, we couldn't find any literature in Korean or English except one case that dealt with spontaneous rupture of the hypopharynx.

• Journal of Chest Surgery
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• v.27 no.4
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• pp.318-324
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• 1994

Cross-clamping of the descending thoracic aorta results in proximal hypertension,increase in left ventricular afterload,and impairment of distal organ perfusion. Bypass of the descending thoracic aorta is frequently advocated as an adjunct for repair of traumatic tears and degenerative aneurysms. Many methods of bypass have been proposed to provide distal perfusion and reduce left ventricular afterload during cross-clamping of the thoracic aorta. At Seoul National University Hospital, 7 patients were treated for the thoracic or thoracoabdominal aortic aneurysm using left atrium-femoral artery bypass with Bio-medicus centrifugal pump between October,1989, and January,1993. There were atherosclerotic thoracic aneurysm in 3 cases, thoracoabdominal aortic aneurysm due to chronic aortic dissection in 3 cases,aortic rupture due to trauma in 1 case. Total of 7 patients were operated by graft replacement with reimplantation of important branches. None of these cases developed severe complications and hospital death. We believe that the Bio-Medicus centrifugal pump is a simple and safe means of perfusing the lower body, kidneys, and spinal cord without necessitating heparinization.

• Journal of Chest Surgery
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• v.24 no.7
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• pp.685-692
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• 1991

Twelve patients underwent surgical interventions for aortic aneurysms consecutively from September 1986 to September 1990 in the Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. They were all men ranging in age from 25 to 68 years with the mean age of 48 years. Five patients of them had aneurysms involving ascending aorta, one aneurysm involving both ascending and descending aorta, four aneurysms involving descending thoracic aorta, and the others had aneurysms involving abdominal aorta. According to morphological classification, six cases of them were in dissection and the others in fusiform aneurysms. All the cases were pathologically true aneurysms and four of them were in acute status. According to causal classification, seven patients of them had atherosclerosis, three cystic medial necrosis, and the others had syphilis and trauma respectively. Six patients with ascending aortic aneurysm had annuloaortic ectasia with aortic regurgitation and underwent ascending aortic graft and aortic valve replacement[Bentall`s operation]. The others with descending thoracic and abdominal aortic aneurysms underwent Dacron graft replacement. Both hemorrhage necessitating reopening of the chest and wound dehiscence were observed in three patients and hoarseness in one patient. Cerebrovascular accident occurred three and a quarter years postoperatively in one patient and he died two days later. The others were followed up via OPD and have been doing well postoperatively.

• Journal of Chest Surgery
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• v.45 no.4
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• pp.257-259
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• 2012

Descending thoracic aorta to femoral artery bypass has been used as a remedial operation after aortic or axillofemoral graft failure or graft infection and other intra-abdominal pathologies not amenable to standard aortofemoral revascularization. It can avoid abdomen approach and has been known as a durable procedure with excellent long-term patency. We reported descending thoracic aorta to femoral artery bypass grafting for primary revascularization in a 55-year-old male with hostile abdominal conditions.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.113-116
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• 2010

A 6-years-old 30 kg male Germen Shepherd dog was presented with the history of abdominal pain, intermittent vomiting and anorexia. Abdominal survey radiography and ultrasonography revealed marked colonic distention. Positive contrast radiography revealed a colonic obstruction between the transverse colon and descending colon. Foreign bodies were identfied during colonoscopy. The descending colon was inflated by the air of endocope then foreign bodies were moved to the descending colon. Foreign bodies were removed by the enema. The dog's clinical signs resolved following foreign body removal.