• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.5
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• pp.1-6
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• 2010

The wavelet transform is a popular tool for studying intermittent and localized phenomena in signals. In this study the wavelet transform of cutting force signals was conducted for the detection of a tool failure in turning process. We used the Daubechies wavelet analyzing function to detect a sudden change in cutting signal level. A preliminary stepped workpiece which had intentionally a hard condition was cut by the inserted cermet tool and a tool dynamometer obtained cutting force signals. From the results of the wavelet transform, the obtained signals were divided into approximation terms and detailed terms. At tool failure, the approximation signals were suddenly increased and the detailed signals were extremely oscillated just before tool failure.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.723-730
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• 1995

Background: Noninvasive ventilation has been used extensively for the treatment of patients with neuromuscular weakness or restrictive chest wall disorders complicated by hypoventilatory respiratory failure. Recently, noninvasive positive pressure ventilation has been used in patients with alveolar hypoventilation, chronic obstructive pulmonary disease(COPD), and adult respiratory distress syndrome. Sanders and Kern reported treatment of obstructive sleep apnea with a modification of the standard nasal CPAP device to deliver seperate inspiratory positive airway pressure(IPAP) and expiratory positive airway pressure(EPAP). Bi-level positive airway pressure(BiPAP) unlike nasal CPAP, the unit delivers a different pressure during inspiration from that during expiration. The device is similar to the positive pressure ventilator or pressure support ventilation. Method and purpose: Bi-level positive airway pressure(BiPAP) system(Respironics, USA) was applied to seven patients with acute respiratory failure and three patients on conventional mechanical ventilation. Results: 1) Two of three patients after extubation were successfully achieved weaning from conventional mechanical ventilation by the use of BiPAP ventilation with nasal mask. Five of seven patients with acute respiratory failure successfully recovered without use of conventional mechanical ventilation. 2) $PaO_2$ 1hour after BiPAP ventilation in acute respiratory failure patients significantly improved more than baseline values(p<0.01). $PaCO_2$ 1hour after BiPAP ventilation in acute respiratory failure patients did not change significantly more than baseline values. Conclusion: Nasal mask BiPAP ventilation can be one of the possible alternatives of conventional mechanical ventilation in acute respiratory failure and supportive method for weaning from mechanical ventilation.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.296-306
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• 2017

Hydropower is now changing its role from the energy generator into the most powerful and reliable tool for stabilizing the electrical network, especially under the increase of intermittent power sources like wind-power and solar-power. Although the hydropower plants are the most robust generating facilities, they are not immune from unexpected severe incidents having long downtime, considerable restoration cost and sometimes fatalities. The present paper provides some study results about severe incidents in the conventional hydropower plants, mainly about the flood, fire and electro-mechanical troubles, except for the incidents of civil facilities. It also provides some possible scenarios which may lead some measures how to avoid such incidents. Finally, it provides some comprehensible recommendations to avoid severe incidents based on experiences.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.255-257
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• 2007

Familial renal amyloidosis was found in a four-year-old male Shar Pei dog. The dog had intermittent fever with signs of renal failure. Another sibling of this dog also showed subclinical signs of renal amyloidosis. Despite aggressive therapy with peritoneal dialysis, the dog died after 10 days of the first presentation. With special staining for amyloid, the renal amylodosis was confirmed.

• Journal of Advanced Navigation Technology
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• v.18 no.4
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• pp.381-386
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• 2014

In order to investigate the effect of contact load, which is one of the fretting corrosion factors affecting the electric connector, a coupled fretting corrosion specimens were prepared using a tin-plated brass coupon with a thickness of $3{\mu}m$. Electric resistance of the contact was measured during the fretting corrosion test period. There was increase in resistance with fretting cycles. The change in resistance can be classified by 3 stages. The first stage exhibited low and stable resistance. Second stage showed steady increment of the resistance and third stage showed very high and intermittent resistance. The relationship between the failure cycle (Nf) and contact force (P) can be drawn as; It is possible to draw the prediction equation for the failure cycle of the electric connector corresponding to the very high and intermittent resistance under various environment conditions through the fretting tests under various conditions such as load, displacement, temperature.

• Journal of Trauma and Injury
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• v.34 no.4
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• pp.299-304
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• 2021

Atypical hemolytic uremic syndrome (aHUS) is a rare, progressive, life-threatening condition of thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic hemolytic anemia, and renal impairment. The mechanisms underlying aHUS remain unclear. Herein, we present the first case in the literature of aHUS after a traumatic injury. A 55-year-old male visited the emergency department after a traumatic injury caused by a tree limb. Abdominal computed tomography revealed a rectal wall defect with significant air density in the perirectal space and preperitoneum, implying rectal perforation. Due to the absence of intraperitoneal intestinal perforation, we performed diverting sigmoid loop colostomy. An additional intermittent simple repair was performed due to perianal and anal injuries. One day postoperatively, his urine output abruptly decreased and serum creatinine level increased. His platelet level decreased, and a spiking fever occurred after 2 days. The patient was diagnosed with acute renal failure secondary to aHUS and was treated with fresh frozen plasma replacement. Continuous renal replacement therapy (CRRT) was also started for oliguria and uremic symptoms. The patient received CRRT for 3 days and intermittent hemodialysis thereafter. After hemodialysis and subsequent supportive treatment, his urine output and renal function improved. The hemolytic anemia and thrombocytopenia also gradually improved. Dialysis was terminated on day 22 of admission and the patient was discharged after recovery. This case suggests that that a traumatic event can trigger aHUS, which should be considered in patients who have thrombocytopenia and acute renal failure with microangiopathic hemolytic anemia. Early diagnosis and appropriate management are critical for favorable outcomes.

• Journal of Chest Surgery
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• v.26 no.4
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• pp.276-281
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• 1993

During the 3 years through December 1992, 118 cases of coronary bypass graft were performed at Department of Cardiothoracic Surgery, Asan Medical Center. They consisted of 80 males and 38 females with the mean age of 59. History of myocardial infarction was noted in 23 cases[20%], congestive heart failure in 11[10%], left ventricular aneurysm in 6, postinfarct VSD in 2, and mitral regurgitation in 1. The angina was stable in 13 cases, and unstable in 104 cases[89%]. Left main stem disease were 41 cases[35%], triple vessel 36[31%], double vessel 30[26%] and single vessel involvement[LAD] in 10. We performed 335 distal bypasses out of 117 cases, with single bypass in 9, double 29, triple 52, quadruple 23, and quintuple 4. Myocardial protections were cardioplegia in 29 and intermittent aortic occlusion 79 and continuous aortic perfusion 7. The ischemic time per graft was 13 minutes[intermittent aortic occlusion group] and 20 minutes [cardioplegia group] respectively, and the mean number of graft per patient is 2.85. Early mortality was 6.8% [8/117]. If we exclude the patients with LV aneurysm, the surgical mortality could be downed to 4.5% [5/111]. The causes of deaths were cardiogenic shock[6], aortic dissection[1], and neurologic complication[1]. We conclude that noncardioplegic myocardial protection may be equally beneficial or sometimes advantageous to cardioplegic technique in aortocoronary bypass graft surgery.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.1
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• pp.99-103
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• 1999

Duodenal web is an uncommon lesion that infrequently cause partial or complete intestinal obstruction. If the duonenal web is incomplete and only partially obstructs the duodenal lumen, the onset of symptoms may be delayed for years, and obstructive symptoms will be only minimal and intermittent. Congenital duodenal obstruction is occasionally associated with intestinal malrotation. We experienced a case of duodenal web associated with intestinal malrotation in a 9-year-old girl who had been suffered from intermittent projectile vomiting since birth without failure to thrive. The diagnosis was made by UGI series & abdominal CT. Patient remained asymptomatic after operation.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.1
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• pp.79-82
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• 2002

Intestinal malrotation is a developmental anomaly resulting from embryologic failure of fixation and rotation of the gut and predisposed to midgut volvulus and small bowel obstruction. Acute midgut volvulus is most often encountered in the newborn period. But older children and adults may have a history of intermittent episodes of partial volvulus presenting with recurrent colicky abdominal pain accompanying bilious vomiting. We experienced a case of intestinal malrotation complicated by midgut volvulus presented with recurrent vomiting and abdominal pain in a 6-year-old boy.

• Elastomers and Composites
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• v.45 no.4
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• pp.263-271
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• 2010

Intermittent CSR testing was used to investigate the degradation of an FKM O-ring, also the prediction of its life-time. An intermittent CSR jig was designed taking into consideration the O-ring's environment under use. The testing allowed observation of the effects of friction, heat loss, and stress relaxation by the Mullins effect. Degradation of O-rings by thermal aging was observed between 60 and $160^{\circ}C$. In the high temperature of range ($100-160^{\circ}C$) O-rings showed linear degradation behavior and satisfied the Arrhenius relationship. The activation energy was about 60.2 kJ/mol. From Arrhenius plots, predicted life-times were 43.3 years and 69.9 years for 50% and 40% failure conditions, respectively. Based on TTS (time-temperature superposition) principle, degradation was observed at $60^{\circ}C$, and could save testing time. Between 60 and $100^{\circ}C$ the activation energy decreased to 48.3 kJ/mol. WLF(William-Landel-Ferry) plot confirmed that O-rings show non-linear degradation behavior under $80^{\circ}C$. The life-time of O-rings predicted by TTS principle was 19.1 years and 25.2 years for each failure condition. The life-time predicted by TTS principle is more conservative than that from the Arrhenius relationship.