• Clinical and Experimental Pediatrics
• /
• 제63권9호
• /
• pp.368-372
• /
• 2020

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by impairments in social interaction and verbal and nonverbal communication. Purpose: Determine the association between use of assisted reproduction technology (ART) and the risk of ASD among children. Methods: This case-control study included 300 participants (100 cases, 200 controls). The control group included women with a child aged 2-10 years without ASD, while the cases were women with a child aged 2-10 years with ASD. We used a researcher-made questionnaire. Data were analyzed using Stata ver. 14 at the 0.05 significance level. Results: In the univariate analysis, there was significant association between child sex, delivery mode, history of preterm delivery, history of using ART, and maternal age at child's birth and the risk of ASD. After the adjustment for other variables, this association was significant for male sex (2.66; 95% confidence interval [CI], 1.11-4.31; P=0.001) and history of using ART (4.03; 95% CI, 1.76-9.21; P=0.001). Therefore, after the adjustment for confounder variables, there was no significant association between ART and the risk of ASD among children (4.98; 95% CI, 0.91-27.30; P=0.065). Conclusion: After the adjustment for other variables, risk factors for ASD were male sex and history preterm delivery. Thus, there was no significant association between ART and the risk of ASD among children.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2019년도 춘계학술논문요약집
• /
• pp.193-194
• /
• 2019

• 항공우주기술
• /
• 제2권1호
• /
• pp.213-222
• /
• 2003

항공우주비행체에 사용되고 있는 복합적층재 구조물에 대한 저속충격 하중이력을 해석하는 방법들에 대하여 고찰하였다. 저속충격문제 연구 초기인 1980년대에 사용된 고전적인 해석방법의 물리적 의미를 살펴보았고, 정현파의 형상으로 가정하여 근사적으로 충격하중 이력을 계산하는 방법에 대해서 살펴보았다. 접촉법칙의 접촉계수나 지수의 크기와 충격하중이력의 해석결과에 미치는 영향을 분석하였고, 결과적으로 선형화된 접촉법칙을 사용하여 충격하중이력을 정확히 해석할 수 있음을 파악하였다. 뿐만 아니라 본 논문에서 제시된 해석 방법을 사용함으로써, 범용 유한요소해석 코드를 사용하여 충격문제를 용이하게 해석할 수 있음을 보였다.

• 건축역사연구
• /
• 제11권4호
• /
• pp.7-19
• /
• 2002

If we compare socio-cultural aspects of the two historical periods known as 'pre-modern' 'modern,' it would seem that the Aristotelian understanding of technology has difficulty explaining techno-cultural phenomenon of modern society. The problems are first that the discourse of scientific technology in the modern period has proceeded without a metaphysical base, and second that nothing in present culture regulates the limitations of scientific technology. The clear distinction between means and ends in the traditional approach is no longer valid in the jumble of interrelationships. Such complexity forces us to acknowledge that means and ends are relative and interchangeable, and that neither has a clear moral superiority over the other. Technology in modern society is no more a neutral means. The products of science do not always exist to serve human ends. In modem architecture and urban design, both its productive and destructive tendencies leave man and his society in an endless confusion of complexity and opposition. These problems of technology still result in unsolved question today. On this point, the discussion another currently prevalent attitude to technology, especially Heideggerian thinking in the below could give a somewhat clearer answer to the problem of modem architecture and technology, although it also comprises limited contemplation in itself.

• International Journal of CAD/CAM
• /
• 제5권1호
• /
• pp.39-47
• /
• 2005

Different CAx systems are being utilized throughout the product lifecycle due to the practical reasons in the supply chain and design processes. One of the major problems facing enterprises of today is how to share and exchange data among heterogeneous applications. Since different software applications use different terminologies, it is difficult to share and exchange the product data with internal and external partners. This paper presents a method to enhance the CAD model interoperability based on feature ontology. The feature ontology has been constructed based on the feature definition of modeling commands of CAD systems. A method for integration of semantic data has been proposed, implemented, and tested with two commercial CAD systems.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• 제22권3호
• /
• pp.298-302
• /
• 2019

A previously healthy 2.5-year-old male child presented with vomiting, diarrhea, and fever. During hospitalization he developed odynophagia and refusal to eat. His symptoms did not respond to acid suppressant therapy. He underwent upper endoscopy which showed severe inflammation, ulcerations and abundant necrosis. Histopathological features and serological testing were consistent with herpetic esophagitis. He had no history of recurrent infections or history of sick contacts. His immunological work up showed normal level of immunoglobulins and his White Blood Cells subpopulations were normal. His HSV serology was positive. The patient was started on acyclovir 5 mg/kg q 8 hours. He resolved his symptoms within 24 hours of treatment.

• Computers and Concrete
• /
• 제30권2호
• /
• pp.113-126
• /
• 2022

Reinforced concrete bearing walls (RCBWs) are one of the most applicable structural systems. Therefore, vulnerability analysis and rehabilitation of the RCBW system are of great importance. In the present study, in order to the more precise investigation of the performance of this structural resistant system, pushover and nonlinear time history analyses based on several assumptions drawing upon experimental research were performed on several models with different stories. To validate the nonlinear analysis method, the analytical and experimental results are compared. Vulnerability evaluation was carried out on two seismic hazard levels and three performance levels. Eventually, the need for seismic rehabilitation with the basic safety objective (BSO) was investigated. The obtained results showed that the studied structures satisfied the BSO of the seismic rehabilitation guidelines. Consequently, according to the results of analyses and the desired performance, this structural system, despite its high structural weight and rigid connections and low flexibility, has integrated performance, and it can be a good option for earthquake-resistant constructions.

• 대기
• /
• 제16권2호
• /
• pp.141-157
• /
• 2006

A revolution in weather and climate forecasting is in progress. This has been made possible as a result of theoretical advances in our understanding of the predictability of weather and climate, and by the extraordinary developments in supercomputer technology. New problem areas have been discovered and different solutions have been found by the recent high performance computers whose performance has been increased rapidly. Such advances in the computational performance may change the strategy of development of numerical models and prediction methods. This paper discusses a brief history and current status of the supercomputers in institutions for research and forecast of weather/climate. The main purpose of this study is to provide the preliminary information about supercomputers such as architecture of system and processor. Such information would be useful for meteorologists to understand the features and the preference of supercomputers in each institution.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 Techno-Fair 및 합동춘계학술대회 논문집 전기물성,응용부문
• /
• pp.183-184
• /
• 2008

The aim of this study is to find out the effects of thermal aging condition on dielectric strength and degree of crtstallinity of XLPE insulation. Thermal properties of XLPE insulation were investigated by DSC(differential scanning calorimetry) and dielectric strength were analyzed using AC BDV tester. Aging of XLPE samples were conducted through different four conditions. The degree of crtstallinity and AC BDV were changed by thermal history. From these results, it can be suggested that DSC and AC BDV test are suitable for diagnostic method of extra high voltage XLPE cable.

• Structural Engineering and Mechanics
• /
• 제15권4호
• /
• pp.463-476
• /
• 2003

This paper deals with nonlinear asymmetric dynamic buckling of clamped laminated angle-ply composite spherical shells under suddenly applied pressure loads. The formulation is based on first-order shear deformation theory and Lagrange's equation of motion. The nonlinearity due to finite deformation of the shell considering von Karman's assumptions is included in the formulation. The buckling loads are obtained through dynamic response history using Newmark's numerical integration scheme coupled with a Newton-Raphson iteration technique. An axisymmetric curved shell element is used to investigate the dynamic characteristics of the spherical caps. The pressure value beyond which the maximum average displacement response shows significant growth rate in the time history of the shell structure is considered as critical dynamic load. Detailed numerical results are presented to highlight the influence of ply-angle, shell geometric parameter and asymmetric mode on the critical load of spherical caps.