일정진폭하중을 받는 유한 길이 봉의 유한요소해석

황은하,Hwang, Eun-Ha 한국전산구조공학회 2010 한국전산구조공학회논문집 Vol.23 No.5

Newmark방법과 같은 직접시간적분법은 시간증분 구간 사이에서 하중이 변하더라도 하중값을 그 시간 구간에서 일정한 하중으로 사용하기 때문에 일정진폭하중과 같은 연속적인 하중함수를 불연속적인 하중함수로 가정하고 수치계산을 수행한다. 따라서 이러한 하중함수의 근사에 따른 오차로 인하여 정확한 수치결과를 계산할 수 없다. 이에 반해, Gurtin의 변분식 에 기초한 유한요소방정식은 하중함수를 시간이력에 대하여 합성적분하여 계산한다. 따라서 시간증분 구간에서 하중이 변하더라도 연속적인 하중함수의 곡선을 따라 가면서 계산하기 때문에 신뢰할 수 있는 수치결과를 구할 수 있다. 본 논문에서는 1차원 막대의 자유단에서 일정진폭하중을 받는 문제를 수치해석하여 Gurtin방법이 Newmark방법 보다 일정진폭하중을 받는 문제에 더 적합한 방법임을 보인다. 또한, Gurtin방법이 일정한 하중을 받는 문제보다 일정진폭하중을 받는 문제에 더 효과적인 방법임을 보인다. Gurtin방법을 FORTRAN으로 프로그래밍하여 해석한 수치결과와 해석용 소프트웨어인 ADINA의 Newmark방법에 의한 수치결과를 비교하여 제시된 수치해의 정확성과 타당성을 검증한다. Direct time integration method such as Newmark method is numerically performed under the assumption that continuous load function such as constant amplitude load can be treated as a discontinuous load fuction. It is due that the load can be treated as a constant value at the given time period regardless of variation of load at the time increment interval. It means the numerical results should be accompanied by the error due to approximation of load fuction. In contrast, the load function is calculated by convolution integral for the given time interval at finite element equation based on Gurtin's variation equation. Therefore. precise numerical results can be obtained by Gurtin's method because of convolution integral for the continuous load fuction curve even at the variation of load function in the given time interval. In this study, we prove that Gurtin's method can be more suitable than Newmark method in the problem of constant amplitude loading, using the numerical results for the free end of the one-dimensional rod. This study also shows that Gurtin's method is more effective in constant amplitude loading than in constant loading. The accuracy and the validity are verified by comparison between the results of in-house FORTRAN code and ADINA, a commercial software supporting Newmark method.

소아 기관지확장증의 임상 특성 및 원인: 단일 기관 연구

황은하 ( Eun Ha Hwang ),김혜영 ( Hye Young Kim ),류민 ( Min Ryu ),김성헌 ( Seong Heon Kim ),손승국 ( Seung Kook Son ),김영미 ( Young Mi Kim ),박희주 ( Hee Ju Park ) 대한소아알레르기호흡기학회 1991 소아알레르기 및 호흡기학회지 Vol.1 No.4

Purpose: The study for bronchiectasis in children is rare in Korea. The aim of this study was investigate the clinical characteristic and associated etiology in pediatric patients with bronchiectasis. Methods: We studied 29 pediatirc patients with bronchiectasis from January 2008 to December 2012 at Pusan National University Hospital. The age, sex, clinical symptoms, signs, radiologic findings, associated etiologic factors, and clinical course were investigated retrospectively. Results: The median age at the time of diagnosis of bronchiectasis was 8.7 years. Chronic coughing was the most common symptom. The associated etiologies were immunodeficiency (31.0%), respiratory infection (27.6%), bronchiolitis obliterans (13.8%), interstitial lung disease (10.3%). The median age at the time of diagnosis of bronchiectasis in immunodeficient patients was 8.3 years. Post infectious bronchiectasis and severe respiratory symptom tend to occur in younger children. Conclusion: The risk factors of bronchiectasis in children are immunodeficiency and respiratory infection. Physicians should evaluate bronchiectasis in children with chronic cough. (Allergy Asthma Respir Dis 2013;1:383-387)

효율적인 어휘 확장을 위한 외래어 효용성 연구

황은하(Hwang Eun ha) 우리말교육현장학회 2014 우리말교육현장연구 Vol.8 No.2

이 연구는 해외에서의 한국어 학습 상황(KFL)에서 효율적인 어휘 확장을 위한 도구로서 외래어 활용의 가능성을 실제적으로 검증하는 것을 목적으로 한다. 일반적으로 어휘 학습에서 외래어는 '학습 용이성'과 '모국어 전이'의 긍정적 역할을 하여 그 활용 가치가 높다고 이론적으로 인식되어 왔다. 그러나 실제로 한국어교육에서 외래어를 활용하는 것이 얼마나 효과가 있을지에 대한 효용성 검토는 이루어지지 않았던 것으로 보인다. 따라서 이 연구에서는 영어권 초급 학습자의 동일 집단을 대상으로 어휘지식 평가척도(Vocabulary Knowledge Scale)를 바탕으로 고안된 외래어 인식 테스트를 통해 학습자의 모국어 지식을 활용한 어휘 유추와 외래어 이해의 상관관계를 검토해 보고자 하였다. 조사 결과 피험자들은 어휘 유추를 통해 이해 가능한 어휘량의 양적인 증가를 보였으며, 질적인 부분에서는 외래어의 유형에 따라 어휘 유추에 성공하거나 실패하는 결과를 낳았다. 본 연구를 통한 외래어 학습의 효용성 검증은 그동안 이론적으로만 논의되었던 외래어 활용 교육에 실제적인 증거를 제시해 주는 동시에, 귀납적으로 학습자들의 전반적인 외래어 지식을 측정해 본 것에 의의가 있다. 따라서 본고에서 논의한 바와 같이, 앞으로 특별히 초급 단계에서 한국어 발음과 철자 교육에 활용되는 명시적인 외래어 교수-학습 및 외래어와 문화 교육과의 연계가 실제 교육 현장에서 구체적으로 실현되어 풍성한 교수-학습 효과를 낳기를 기대한다. This study examines the validity to use Korean Loanwords for effective and efficient vocabulary expanding in KFL. Many studies agree with the importance of loanwords in vocabulary expanding with regard to its positive transfer from L1, which is English in this case, and learnability. Consequently, there are several researches focusing on Korean loanwords in effective Korean vocabulary teaching: presenting an essential loanwords list for academic purpose, insisting on teaching a notational system of loanwords, and emphasizing cultural changed meanings of Korean loanwords for learners. However, when it comes to the validity of using loanwords in KFL and KSL for rapid vocabulary expanding it is very hard to find a research that attempt to prove it with empirical evidence. Therefore with the purpose of examining the validity of using Korean loanwords for expanding vocabulary knowledge from a receptive perspective, in this study, lexical inferencing using KFL learners' L1 was encouraged. Participants went through a word list containing 223 Korean loanwords. The checklist using modified version of Vocabulary Knowledge Scale(VKS) was utilized to measure the learners' size and depth of vocabulary knowledge. Results indicate a notable progress after lexical inferencing. While lexical inferencing was effective on most of the loanwords, some words, such as having sociocultural changes in their meanings, and new word formations, were difficult to presume with L1 knowledge. As a result, this study suggests an explicit loanwords teaching for efficient vocabulary expanding not only by using lexical inferencing but also by focusing on semantically changed loanwords.

소아 기관지확장증의 임상 특성 및 원인: 단일 기관 연구

황은하 ( Eun Ha Hwang ),김혜영 ( Hye Young Kim ),류민 ( Min Ryu ),김성헌 ( Seong Heon Kim ),손승국 ( Seung Kook Son ),김영미 ( Young Mi Kim ),박희주 ( Hee Ju Park ) 대한천식알레르기학회 2013 Allergy Asthma & Respiratory Disease Vol.1 No.4

Purpose: The study for bronchiectasis in children is rare in Korea. The aim of this study was investigate the clinical characteristic and associated etiology in pediatric patients with bronchiectasis. Methods: We studied 29 pediatirc patients with bronchiectasis from January 2008 to December 2012 at Pusan National University Hospital. The age, sex, clinical symptoms, signs, radiologic findings, associated etiologic factors, and clinical course were investigated retrospectively. Results: The median age at the time of diagnosis of bronchiectasis was 8.7 years. Chronic coughing was the most common symptom. The associated etiologies were immunodeficiency (31.0%), respiratory infection (27.6%), bronchiolitis obliterans (13.8%), interstitial lung disease (10.3%). The median age at the time of diagnosis of bronchiectasis in immunodeficient patients was 8.3 years. Post infectious bronchiectasis and severe respiratory symptom tend to occur in younger children. Conclusion: The risk factors of bronchiectasis in children are immunodeficiency and respiratory infection. Physicians should evaluate bronchiectasis in children with chronic cough.

조직간 관계특징이 재난관리 협력 및 성과에 미치는 영향

황은하(Hwang, Eun-Ha),정덕훈(Jeong, Duk-Hoon) 대한경영학회 2011 大韓經營學會誌 Vol.24 No.3

공리적설계를 이용한 휴대폰 슬라이드 기구의 스파이럴 스프링 설계

황은하 ( Eun-ha Hwang ),한덕희 ( Deok-hee Han ) 한국산업융합학회 2007 한국산업융합학회 논문집 Vol.10 No.3

It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

국가안전관리 상호운용성 확보를 위한 기술참조모델과 표준프로파일 적용

황은하 ( Eun-ha Hwang ),황종선 ( Chong-sun Hwang ) 한국정보처리학회 2005 한국정보처리학회 학술대회논문집 Vol.12 No.1

기상이변과 사회구조의 복잡화에 따라 재난의 유형이 다양화되고, 발생 빈도와 피해 규모가 증가함에 따라 정부는 안전관련 법령의 정비, 소방방재청의 신설 등 “국민이 편안한 안전사회”를 건설하기 위해 재난관련 각종 정책, 조직 및 정보시스템을 정비하고 있다. 본 연구는 범국가 차원에서 안전관리 관련 기관간 업무 및 유기적 연계와 정보 공동 활용을 위하여 국가안전관리정보시스템 구축시 이식성과 상호운용성 확보를 위한 기술참조모델과 표준프로파일을 설계한다.

유한요소법을 이용한 과도 선형 동탄성 해석

황은하(Eun-Ha Hwang),오근(Guen Oh) 한국산업융합학회 2009 한국산업융합학회 논문집 Vol.12 No.3

A new finite element equation is derived by applying quadratic and cubic time integration scheme to the variational formulation in time-integral for the analysis of the transient elastodynamic problems to increase the numerical accuracy and stability. Emphasis is focused on methodology for cubic time integration scheme procedure which are never presented before. In this semidiscrete approximations of the field variables, the time axis is divided equally and quadratic and cubic time variation is assumed in those intervals, and space is approximated by the usual finite element discretization technique. It is found that unconditionally stable numerical results are obtained in case of the cubic time variation. Some numerical examples are given to show the versatility of the presented formulation.

2세 여아에서 성장 부진과 다리 통증을 동반한 1형 고셔병 증례

박예슬,황재연,황은하,전종근,이범희,유한욱,김유미,Park, Yesul,Hwang, Jae-Yeon,Hwang, Eun Ha,Cheon, Chong Kun,Lee, Beom Hee,Yoo, Han-Wook,Kim, Yoo-Mi 대한유전성대사질환학회 2017 대한유전성대사질환학회지 Vol.17 No.2

고셔병은 리소좀축적병으로 lysosomal hydrolase glucocerebrosidase 결여로 간비장비대, 골격계 증상, 빈혈, 혈소판 감소증의 증상을 나타내는 드문 상염색체 유전 질환이다. 본 증례에서는 2세 여아에서 간비장비대, 다리 통증, 성장부진이 관찰되어 시행한 단순 방사선 촬영 검사에 Erlenmeyer flask 변형을 확인하여 고셔병을 의심하였고 효소 분석 및 유전자 검사를 통해 확진하였다. 환아에서 한국인 비신경형 고셔병에서만 관찰되는 G46E 돌연변이를 확인하였고 1년 간의 효소 대체 요법을 통해 성장, 혈액학적 지표, 간비장비대 및 골증상의 호전을 확인하였기에 본 증례를 보고하는 바이다. Gaucher disease (GD) is caused by the deficiency of glucocerebrosidase. In pediatric patients with GD, especially Type I GD, enzyme replacement therapy (ERT) can reduce the hepatosplenomegaly and improve the hematologic finding and growth velocity. Herein, we report a 2-year-old girl with Type I GD presented with hepatosplenomegaly, bone pain and growth retardation. A 2 year-old-girl was referred to our hospital due to severe hepatosplenomegaly and growth retardation. She suffered from both leg pain and chronic fatigue. Simple x-ray showed widened distal long bones like that of an 'Erlenmeyer flask' which is associated with GD. The laboratory test showed anemia and thrombocytopenia. The enzyme activity was markedly reduced and the direct sequencing of the GBA gene showed the compound heterozygous mutations, p.G46E and p.L444P. As the G46E have been considered as the protective gene against neuronopathic genotype, we could assess the Type I GD in this patient. After one year of ERT, the growth velocity became 11 cm per year. Bone pain and fatigue disappeared. The volume of liver and spleen was reduced from $683cm^3$ and $703cm^3$ to $590cm^3$ and $235cm^3$, respectively. Although GD is an extremely rare disease in Korea, growth retardation and bone pain in children are the important signs which lead to early detection of GD and a simple radiologic finding is helpful to assess the GD at outpatient clinic. We highlight that the early diagnosis and early ERT is important for good growth and outcome for pediatric patients with GD.

영재학생과 일반학생의 완벽주의와 학교적응간의 관계

한기순(Ki-Soon Han),황은하(Eun-ha Hwang) 한국열린교육학회 2010 열린교육연구 Vol.18 No.3

본 연구는 영재학생 206명과 일반학생 204명을 대상으로 완벽주의, 자기효능감, 학교적응의 차이를 알아보고, 각 집단에서 완벽주의와 학교적응 간의 관계에서 자기효능감의 매개될 가능성을 살펴보고자 하는데 그 목적이 있다. 완벽주의와 관련하여 적응적 측면과 부적응적 측면의 다차원적 이해를 위해 Frost의 다차원적 완벽주의 척도가 활용되었다. 연구결과 완벽주의, 자기효능감, 학교 적응 모두에서 영재학생과 일반학생 간에 유의미한 차이를 나타냈다. 영재학생과 일 반학생 두 집단에서 완벽주의와 학교적응 간의 관계에서 자기효능감이 매개되는지의 여부를 Baron과 Kenny의 3단계의 회귀분석을 통해 알아보았다. 그 결과 영재학생의 경우 적응적 완벽주의와 학교적응 간의 관계에서는 자기효능감이 부분매개로, 부적응적 완벽주의와 학교적응 간의 관계에서는 자기효능감이 완전매개로 나타났다. 일반학생의 경우에서는 독립변수가 적응적 완벽주의인 경우와 부적응적 완벽주의인 경우에 따라 자기효능감의 매개효과가 적응적 완벽주의 경우 완전매개로, 부적응적 완벽주의의 경우 부분매개로 나타났다. 본 연구결과가 영재아의 특성이해 및 학교적응과 관련하여 어떠한 시사점이 있는가가 논의되었다. The purposes of the present study were to find out the differences of perfectionism, self-efficacy and school adjustment in gifted and general students and to investigate the relationship between perfectionism and school adjustment with the mediating effect of the self-efficacy. For the study 206 gifted students and 204 general students participated. To examine the adaptive and maladaptive aspects of perfectionism, Frost's Multidimensional Perfectionism Scale was utilized. The results indicate that there were significant differences between the gifted and the general students in all three variables investigated, perfectionism, self-efficacy, and school adjustment. Mediating effect of self-efficacy in the relationship between adaptive/maladaptive perfectionism and school adjustment was examined using Baron and Kenny's 3 step regression analysis. As for gifted group, self-efficacy was identified to act as a partial mediator in the relation between adaptive perfectionism and school adjustment, while acting as a complete mediator in the relation between maladaptive perfectionism and school adjustment. With regard to the mediation effects for the general students, self-efficacy showed to act as a complete mediator for the adaptive perfectionism and as a partial mediator for the maladaptive one. Implication of the study related to the gifted education was discussed.