• Title/Summary/Keyword: Rare events

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Malformations of cortical development: genetic mechanisms and diagnostic approach

  • Lee, Jeehun
    • Clinical and Experimental Pediatrics
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    • v.60 no.1
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    • pp.1-9
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    • 2017
  • Malformations of cortical development are rare congenital anomalies of the cerebral cortex, wherein patients present with intractable epilepsy and various degrees of developmental delay. Cases show a spectrum of anomalous cortical formations with diverse anatomic and morphological abnormalities, a variety of genetic causes, and different clinical presentations. Brain magnetic resonance imaging has been of great help in determining the exact morphologies of cortical malformations. The hypothetical mechanisms of malformation include interruptions during the formation of cerebral cortex in the form of viral infection, genetic causes, and vascular events. Recent remarkable developments in genetic analysis methods have improved our understanding of these pathological mechanisms. The present review will discuss normal cortical development, the current proposed malformation classifications, and the diagnostic approach for malformations of cortical development.

Extreme wind prediction and zoning

  • Holmes, J.D.;Kasperski, M.;Miller, C.A.;Zuranski, J.A.;Choi, E.C.C.
    • Wind and Structures
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    • v.8 no.4
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    • pp.269-281
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    • 2005
  • The paper describes the work of the IAWE Working Group WGF - Extreme Wind Prediction and Zoning, one of the international codification working groups set up in 2000. The topics covered are: the international database of extreme winds, quality assurance and data quality, averaging times, return periods, probability distributions and fitting methods, mixed wind climates, directionality effects, the influence of orography, rare events and simulation methods, long-term climate change, and zoning and mapping. Recommendations are given to promote the future alignment of international codes and standards for wind loading.

A novel association between cerebral sinovenous thrombosis and nonketotic hyperglycinemia in a neonate

  • Yurttutan, Sadik;Oncel, Mehmet Yekta;Yurttutan, Nursel;Degirmencioglu, Halil;Uras, Nurdan;Dilmen, Ugur
    • Clinical and Experimental Pediatrics
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    • v.58 no.6
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    • pp.230-233
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    • 2015
  • Lethargy in newborns usually indicates central nervous system dysfunction, and many conditions such as cerebrovascular events, infections, and metabolic diseases should be considered in the differential diagnosis. Nonketotic hyperglycinemia is an autosomal recessive error of glycine metabolism, characterized by myoclonic jerks, hypotonia, hiccups, apnea, and progressive lethargy that may progress to encephalopathy or even death. Cerebral sinovenous thrombosis is a rare condition with various clinical presentations such as seizures, cerebral edema, lethargy, and encephalopathy. Here, we report the case of a newborn infant who presented with progressive lethargy. An initial diagnosis of cerebral venous sinus thrombosis was followed by confirmation of the presence of nonketotic hyperglycinemia.

Benford's Law in Linguistic Texts: Its Principle and Applications (언어 텍스트에 나타나는 벤포드 법칙: 원리와 응용)

  • Hong, Jung-Ha
    • Language and Information
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    • v.14 no.1
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    • pp.145-163
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    • 2010
  • This paper aims to propose that Benford's Law, non-uniform distribution of the leading digits in lists of numbers from many real-life sources, also appears in linguistic texts. The first digits in the frequency lists of morphemes from Sejong Morphologically Analyzed Corpora represent non-uniform distribution following Benford's Law, but showing complexity of numerical sources from complex systems like earthquakes. Benford's Law in texts is a principle reflecting regular distribution of low-frequency linguistic types, called LNRE(large number of rare events), and governing texts, corpora, or sample texts relatively independent of text sizes and the number of types. Although texts share a similar distribution pattern by Benford's Law, we can investigate non-uniform distribution slightly varied from text to text that provides useful applications to evaluate randomness of texts distribution focused on low-frequency types.

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Total Occlusion of the Abdominal Aorta Caused by Detachment of Cardiac Myxoma

  • Hong, Sung-Yong;Park, Kyung-Taek;Choe, Hyun-Min
    • Journal of Chest Surgery
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    • v.45 no.3
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    • pp.183-185
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    • 2012
  • Abdominal aortic occlusion (AAO) caused by detachment of cardiac myxoma (CM) is a very rare complication in patients with CM. Although the nature of CMs has been well established, detachment of CM may cause unexpected serious complications such as vicious embolic events. Actually, in several cases of AAO caused by detachment of CM, it has been reported that CM fragments easily migrated to the brain, heart, and lungs, and caused lifelong neurological complications despite appropriate surgical therapy. Herein, we report a case of a patient with AAO caused by detachment of CM who underwent CM excision and abdominal aortic thromboembolectomy. Additionally, we have presented the preoperative and postoperative images using 64-multidetector computed tomography.

Exact Asymptotics in a Multi-class M/G/1 Queue

  • Lee, Ji-Yeon;Dabrowski, Andre;McDonald, David R.
    • 한국데이터정보과학회:학술대회논문집
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    • 2006.04a
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    • pp.43-47
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    • 2006
  • Consider a multitype queue where queued customers arc served in their order of arrival at a rate which depends on the customer type. Here we calculate the sharp asymptotics of the probability the total number of customers in the queue reaches a high level before emptying. The natural state space to describe this queue is a tree whose branches increase in length as the number of customers in the queue grows. Consequently it is difficult to prove a large deviation principle. Moreover, since service rates depend on the customer type the stationary distribution is not of product form so there is no simple expression for the stationary distribution. Instead, we use a change of measure technique which increases the arrival rate of customers and decreases the departure rate thus making large deviations common.

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Pulmonary Thromboembolism after Intravenous Immunoglobulin Therapy in Guillain-Barre Syndrome (길랭-바레증후군에서 면역글로불린 치료 후 발생한 폐혈전색전증)

  • Park, Jin-Mo;Kim, Nam Kyun;Park, Jin-Sung
    • Annals of Clinical Neurophysiology
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    • v.18 no.1
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    • pp.14-17
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    • 2016
  • Intravenous immunoglobulin (IVIG) is a safe treatment to treat various neurological disorders, but fatal thrombotic events as rare complications have been reported. A 54-year-old woman with Guillain-Barre syndrome complained of dyspnea during IVIG treatment. She was finally diagnosed with pulmonary thromboembolism. To the best of our knowledge, this is the first case of pulmonary thromboembolism associated with IVIG treatment in a Korean patient with Guillain-Barre syndrome.

Performance Analysis of VaR and ES Based on Extreme Value Theory

  • Yeo, Sung-Chil
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.389-407
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    • 2006
  • Extreme value theory has been used widely in many areas of science and engineering to deal with the assessment of extreme events which are rare but have catastrophic consequences. The potential of extreme value theory has only been recognized recently in finance area. In this paper, we provide an overview of extreme value theory for estimating and assessing value at risk and expected shortfall which are the methods for modelling and measuring the extreme financial risks. We illustrate that the approach based on extreme value theory is very useful for estimating tail related risk measures through backtesting of an empirical data.

Treatment of Complete Persistent Sciatic Artery with Distal Thromboembolism by Thromboembolectomy Only

  • Choi, Yun Kyung;Ahn, Jae Ho;Kim, Kwan Chang;Won, Tae Hee
    • Journal of Chest Surgery
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    • v.45 no.5
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    • pp.342-344
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    • 2012
  • A persistent sciatic artery (PSA) is very rare congenital vascular anomaly which is present in 0.025% to 0.04% of the population by an angiographic study. A PSA is usually combined with aneurismal disease or thromboembolic events because of its arteriosclerosis and vessel wall degeneration. The treatments of symptomatic PSA are comprised of exclusion of PSA from circulation and bypass surgery for the lower limb. However, surgical treatment should be tailored to its anatomy and presentation. We report a successful treatment of PSA with distal thromboembolism by thromboembolectomy without bypass surgery.

A Case of Midgut Volvulus with Gastric Perforation and Periveintricular Leukomalacia in a Term Infant

  • Park, Seul Gi;Hwang, Jong Hee
    • Neonatal Medicine
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    • v.28 no.1
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    • pp.53-58
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    • 2021
  • Intestinal malrotation with midgut volvulus (MV) is a life-threatening surgical emergency. Most events of MV occur in the neonatal period with bilious vomiting, abdominal distension, feeding intolerance, and bloody stools. Neonatal gastric perforation (GP) is a rare and life-threatening condition associated with high mortality. It occurs either in an idiopathic form or in association with gastrointestinal anomalies such as duodenal atresia and MV. The pathogenesis of both MV and GP is related to ischemic change and inflammatory response. MV and GP can lead to morbidities such as sepsis, intestinal ischemia, and organ failure, but not neurologic problems. We herein report the case of a term infant at 5 days after birth, with MV accompanied by GP, who developed periventricular leukomalacia.