• Communications for Statistical Applications and Methods
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• v.26 no.3
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• pp.239-259
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• 2019

The transmuted generalized extreme value (TGEV) distribution was first introduced by Aryal and Tsokos (Nonlinear Analysis: Theory, Methods & Applications, 71, 401-407, 2009) and applied by Nascimento et al. (Hacettepe Journal of Mathematics and Statistics, 45, 1847-1864, 2016). However, they did not give explicit expressions for all the moments, tail behaviour, quantiles, survival and risk functions and order statistics. The TGEV distribution is a more flexible model than the simple GEV distribution to model extreme or rare events because the right tail of the TGEV is heavier than the GEV. In addition the TGEV distribution can adjusted various forms of asymmetry. In this article, explicit expressions for these measures of the TGEV are obtained. The tail behavior and the survival and risk functions were determined for positive gamma, the moments for nonzero gamma and the moment generating function for zero gamma. The performance of the maximum likelihood estimators (MLEs) of the TGEV parameters were tested through a series of Monte Carlo simulation experiments. In addition, the model was used to fit three real data sets related to financial returns.

• International Journal of Contents
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• v.14 no.4
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• pp.57-64
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• 2018

Among many UNESCO world heritage sites in Korea, "Historic Village: Hahoe" is adjacent to Nakdong River and it is imperative to monitor the water level near the village in a bid to forecast floods and prevent disasters resulting from floods.. In this paper, we propose a recurrent neural network with multiple hidden layers to predict the water level near the village. For training purposes on the proposed model, we adopt the sixth-order error function to improve learning for rare events as well as to prevent overspecialization to abundant events. Multiple hidden layers with recurrent and crosstalk links are helpful in acquiring the time dynamics of the relationship between rainfalls and water levels. In addition, we chose hidden nodes with linear rectifier activation functions for training on multiple hidden layers. Through simulations, we verified that the proposed model precisely predicts the water level with high peaks during the rainy season and attains better performance than the conventional multi-layer perceptron.

• International journal of thyroidology
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• v.11 no.2
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• pp.71-74
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• 2018

Adverse events such as hemoptysis and gastrointestinal hemorrhage during tyrosine kinase inhibitor treatment are relatively rare, but the severity of the bleeding can be higher than other common adverse events. It is necessary to educate patients about its possibility so that they can be found early. In this case report of radioiodine refractory thyroid cancer patient, hemoptysis and gastrointestinal bleeding has occurred following lenvatinib administration. Drug interruption and dose modification and dose interruption were required in addition to management for bleeding itself. It is necessary to confirm the high risk of bleeding before the administration of tyrosine kinase inhibitors, and to appropriately control the follow-up interval and drug dosage accordingly.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.1
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• pp.39-44
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• 2020

Homozygous familial hypercholesterolemia (HoFH) is a rare inherited disorder that presents as abnormally elevated levels of low-density lipoprotein cholesterol and premature heart disease, requiring frequent intervention through lipid apheresis for management. The risk of perioperative cardiac events is higher in patients with HoFH because of its pathophysiological manifestations in the vascular system. Careful cardiac precautions and anesthetic assessments are necessary to ensure patient safety. In the following case report, we discuss the clinical course and anesthetic considerations for a 14-year-old girl with HoFH undergoing sedation for dental extractions and mandibular molar uprighting in an outpatient oral surgery clinic. Considerations included the use of heparin in the patient's weekly plasma lipid apheresis treatment. In order to reduce the risks of peri- and postoperative bleeding and perioperative cardiac events, the operation was scheduled for 4 days after apheresis. This allowed for adequate heparin clearance, while also reducing the likelihood of possible cardiac events. A literature review revealed no results for the outpatient management of patients with HoFH undergoing sedation for noncardiac procedures. Our reported case serves as a clinical example for physicians to be utilized in the future.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.21 no.3
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• pp.214-217
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• 2018

Inflammatory bowel disease (IBD) is a well-recognized risk factor for thrombotic events in adults but data on children are scarce. In the great majority of adult patients, thrombotic events are usually deep vein thrombosis and pulmonary embolism. Other sites such as jugular veins are extremely rare. We present a case of Lemierre syndrome in an adolescent girl with active ulcerative colitis and discuss possible risk factors. This is the first reported case of severe Lemierre syndrome with thrombus extension to cranial veins in a patient with ulcerative colitis. Early recognition of Lemierre syndrome in patients who present with rapidly worsening symptoms of neck pain, fever and signs of pharyngitis is imperative because it increases a chance of favorable prognosis. It is important for pediatricians treating IBD patients not to underestimate possible thrombotic events in children with IBD. Recognition of additional risk factors is crucial for prompt diagnosis and adequate treatment.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.547-550
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• 2004

We present a multiscale scheme which describes the dynamic pictures of atoms in the multiple length-scale systems. Large-scale atomic systems are reduced to coarse grained system by the quasicontinuum, of which the dynamic pathways are rendered by the action-derived molecular dynamics proved effective for multiple time-scale problems such as rare events. Adatom diffusions on the metal (001) surface are selected for our numerical examples. The energy barriers of the diffusions and the real dynamic trajectories of the adatoms are calculated.

• Journal of Korean Neurosurgical Society
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• v.38 no.3
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• pp.227-230
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• 2005

Hearing loss in the contralateral functioning ear is a rare and distressing complication after vetibular schwannoma removal. Various possible mechanisms have been proposed, however, the etiology of hearing loss is not clear. Fortunately, this is an extremely rare occurrence, sporadic case reports have appeared in the literatures. We report two cases of acute contralateral hearing loss after vestibular schwannoma removal and discuss the possible mechanisms of the phenomenon. Although permanent deafness may result, in our cases, the hearing loss was temporary, returning to near preoperative level within one month. The etiology of hearing loss in one case is thought to be cerebrospinal fluid leakage. However, in the other case, the cause of hearing loss is not clear. A better understanding of these events may lead to preventive measures to avoid contralateral hearing loss after vestibular schwannoma removal.

• Journal of mucopolysaccharidosis and rare diseases
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• v.2 no.2
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• pp.46-49
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• 2016

Achondroplasia is autosomal dominant genetic disease and fibroblast growth factor receptor 3 (FGFR3) is currently known to be the only gene that causes achondroplasia. Gain-of function mutation in fibroblast-growth-factor-receptor 3 (FGFR3) causes the disease and C-type natriuretic peptide (CNP) antagonizes FGFR3 downstream signaling by inhibiting the pathway of mitogen-activated protein kinase (MAPK). As FGFR3-related skeletal dysplasias are caused by growth attenuation of the cartilage, chondrocytes appear to be unique in their response to FGFR3 activation. However, the full spectrum of molecular events by which FGFR3 mediates its signaling is just beginning to emerge. This article summaries the mechanisms of FGFR3 function in skeletal dysplasias, the extraordinary cellular manifestations of FGFR3 signaling in chondrocytes, and finally, the progress toward therapy for ACH.

• Journal of Chest Surgery
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• v.51 no.5
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• pp.333-337
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• 2018

Background: Pinch-off syndrome (POS) is a rare complication after totally implantable venous access device (TIVAD) implantation. In cancer patients, it is important to prevent this rare complication and to recognize it early if it does occur. We present a case series of POS after TIVAD implantation and the results of a literature search about this complication. Methods: From July 2006 to December 2015, 924 permanent implantable central venous catheter implantation procedures were performed. The most common indication was vascular access for chemotherapy. Results: POS occurred in 5 patients in our clinic. Two patients experienced POS within 2 weeks, and the other 3 patients were admitted to department of surgery, Istanbul Faculty of Medicine at 6 to 14 months following implantation. The catheters were found to be occluded during medication administration, and all patients complained of serious pain. The transected fragments of the catheters had migrated to the heart. They were successfully removed under angiography with a single-loop snare. Conclusion: POS is a serious complication after TIVAD implantation. It is important to be aware of this possibility and to make an early diagnosis in order to prevent complications such as drug extravasation and occlusion events.

• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.386-389
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• 2009

On rare occasions, percutaneous vertebroplasty (PV) may be associated with adverse spinal and extraspinal events. Subarachnoid hemorrhage (SAH) has not been reported complication following a PV. This is a report of two elderly women with spine compressions who developed idiopathic SAH after injecting polymethylmethacrylate into the thoracolumbar region transcutaneously. PV was performed as an usual manner on prone position under local anesthesia for these patients. During the interventions, two patients complained of a bursting nature of headache and their arterial blood pressure was jumped up. Computed tomography scans revealed symmetric SAH on the both hemispheres and moderate degree of hydrocephalus. Any intracranial vascular abnormalities for their SAH were not evident on modern neuroangiography modalities. One patient received a ventricular shunt surgery, but both fully recovered from the procedure-related SAH. The pathophysiologic mechanism that induce SAH will be discussed, with suggesting the manner that prevent and minimize this rare intracranial complication after PV.