• Title/Summary/Keyword: History as a tool

검색결과 376건 처리시간 0.029초

측정가속도를 이용한 구조물의 지진손상평가 (Seismic Damage Assessment on Structures using Measured Acceleration)

  • 오성호;신수봉
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2003년도 춘계 학술발표회논문집
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    • pp.216-223
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    • 2003
  • A time-domain system identification (SI) method is developed for seismic damage assessment on structures. SI algorithms for complete measurements with respect to degrees-of-freedom are proposed. To take account of nonlinear dynamic response, an equation error in the incremental dynamic governing equation is defined for complete measurement between measured and computed acceleration. Variations of stiffness and damping parameters during earthquake vibration are chased by utilizing a constrained nonlinear optimization tool available in MATLAB. A simulation study has been carried out to identify damage event and to assess damage severity by using measured acceleration time history. Mass properties are assumed as known a priori. The effects of measurement noise on the identification are also investigated.

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Application of mathematical metamodeling for an automated simulation of the Dong nationality drum tower architectural heritage

  • Deng, Yi;Guo, Shi Han;Cai, Ling
    • Computers and Concrete
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    • 제28권6호
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    • pp.605-619
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    • 2021
  • Building Information Modeling (BIM) models are a powerful tool for preserving and using architectural history. Manually creating information models for such a significant number and variety of architectural monuments as Dong drum towers is challenging. The building logic based on "actual measurement construction" was investigated using the metamodel idea, and a metamodel-based automated modeling approach for the wood framework of Dong drum towers was presented utilizing programmable algorithms. Metamodels of fundamental frame kinds were also constructed. Case studies were used to verify the automated modeling's correctness, completeness, and efficiency using metamodel. The results suggest that, compared to manual modeling, automated modeling using metamodel may enhance the model's integrity and correctness by 5-10% while also reducing time efficiency by 10-20%. Metamodel and construction logic offer a novel way to investigate data-driven autonomous information-based modeling.

철도위험물수송에 관한 위험도 정량화방안 및 경감대책 연구 (A Study on Quantitative Risk Assessment Method and Risk Reduction Measures for Rail Hazardous Material Transportation)

  • 이상곤;조원철;이태식
    • 한국재난관리표준학회지
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    • 제1권3호
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    • pp.69-76
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    • 2008
  • 본 연구는 철도를 통한 위험물 운송시 발생할 수 있는 위험을 정량화하는 방법을 개발하고, 이를 통한 경감대책을 제시한다. 본 논문에서는 철도위험물 수송에 관한 위험도를 평가하기 위한 방법으로 정량적 위험도 평가 방법을 채택하였으며, 과거 사고이력과 더불어 위험이 높을 것으로 판단되는 익산시를 대상으로 했다. 노출인원에 대한 평균개인의 위험을 거리에 따른 위험도로 표현한 결과 원자력 기준 미만으로 안전한 것으로 판단되고, 또한 사회적 위험도로 표현한 결과, 위험경감대책 적용요구 구간(ALARP)범위 내에 포함되어 이에 대한 경감대책을 제시하였다. 위험 경감대책으로 차량설계, 운영, 피해확대 방지, 발생빈도 감소를 위한 탈선사고 방지, 경로변경 방안 등을 제시하였으며 경감대책의 적용으로 높은 수준의 안전성을 확보할 수 있을 것으로 기대된다.

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대기오염과 관련된 건강영향을 평가하기 위한 설문 개발 (Development of Questionnaire for Evaluating Health Effect Associated with Air Pollution)

  • 주영수;김대성;강종원;성주헌;강대희;조수헌;백도명
    • Journal of Preventive Medicine and Public Health
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    • 제30권4호
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    • pp.852-869
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    • 1997
  • This study was conducted to develop and evaluate the reliability and the validity of a questionnaire in order to determine the applicability as a screening tool for estimating environmental exposure and health effects related to air pollution. The questionnaire was developed with adopting some items of others such as ISAAC or ATS-DLD. And then we performed test-retest to 89 middle school students and their mothers at interval of three months. Cohen's Kappa values, weighted Kappa values, Spearman's correlation coefficients, and Pearson's correlation coefficients for each item were computed as reliability coefficients. The validity coefficients and validity coefficient bounds were also obtained by simply using these reliability coefficients. As results, Kappa ranged broadly from 0.10 to 0.61 of the items 'diet', $0.52\sim0.79$ of the environmental tobacco smoke, $0.39\sim0.44$ of the functional categories of surrounding environment, and $0.39\sim0.44$ of the using transportation systems; these items were regarded as confounding factors. For items related to health outcomes, Kappa ranged from -0.02 to 0.37 in the respiratory system of past medical history, and from 0.11 to 0.55 in the current health status. But Kappa of the others were over 0.60. In conclusion, if some items can be corrected or modified, the questionnaire developed in this study can be used as a tool for evaluating environmental exposure and health effects associated with air pollution.

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황해 갑각 중형동물플랑크톤의 형태 분석과 DNA 메타바코딩 비교 (Comparison of Morphological Analysis and DNA Metabarcoding of Crustacean Mesozooplankton in the Yellow Sea)

  • 김가람;강형구;김충곤;최재호;김성
    • Ocean and Polar Research
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    • 제43권1호
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    • pp.45-51
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    • 2021
  • Studies on marine zooplankton diversity and ecology are important for understanding marine ecosystem, as well as environmental conservation and fisheries management. DNA metabarcoding is known as a useful tool to reveal and understand diversity among animals, but a comparative evaluation with classical microscopy is still required in order to properly use it for marine zooplankton research. This study compared crustacean mesozooplankton taxa revealed by morphological analysis and metabarcoding of the cytochrome oxidase I (COI). A total of 17 crustacean species were identified by morphological analysis, and 18 species by metabarcoding. Copepods made up the highest proportion of taxa, accounting for more than 50% of the total number of species delineated by both methods. Cladocerans were not found by morphological analysis, whereas amphipods and mysids were not detected by metabarcoding. Unlike morphological analysis, metabarcoding was able to identify decapods down to the species level. There were some discrepancies in copepod species, which could be due to a lack of genetic database, or biases during DNA extraction, amplification, pooling and bioinformatics. Morphological analysis will be useful for ecological studies as it can classify and quantify the life history stages of marine zooplankton that metabarcoding cannot detect. Metabarcoding can be a powerful tool for determining marine zooplankton diversity, if its methods or database are further supplemented.

Advanced inelastic static (pushover) analysis for earthquake applications

  • Elnashai, A.S.
    • Structural Engineering and Mechanics
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    • 제12권1호
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    • pp.51-69
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    • 2001
  • Whereas the potential of static inelastic analysis methods is recognised in earthquake design and assessment, especially in contrast with elastic analysis under scaled forces, they have inherent shortcomings. In this paper, critical issues in the application of inelastic static (pushover) analysis are discussed and their effect on the obtained results appraised. Areas of possible developments that would render the method more applicable to the prediction of dynamic response are explored. New developments towards a fully adaptive pushover method accounting for spread of inelasticity, geometric nonlinearity, full multi-modal, spectral amplification and period elongation, within a framework of fibre modelling of materials, are discussed and preliminary results are given. These developments lead to static analysis results that are closer than ever to inelastic time-history analysis. It is concluded that there is great scope for improvements of this simple and powerful technique that would increase confidence in its employment as the primary tool for seismic analysis in practice.

진동계측자료 기반 안전성평가 시스템을 활용한 건축물의 비틀림 분석 방법 개발 (A Study on the Development of Torsion Analysis Method for Buildings Using Rapid Safety Assessment System Based on Accelerometers)

  • 정성훈;장원석;이정한;박병철
    • 한국지진공학회논문집
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    • 제25권6호
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    • pp.275-281
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    • 2021
  • In this study, algorithms for analyzing the torsion of buildings under earthquake excitation are developed. The algorithm and formulations to account for the torsional angle are verified by analyzing the seismic acceleration time history data. The method was applied to the reference buildings to examine their operation and usability. The reference application demonstrated that the noise-canceling scheme successfully overcame various obstacles in the field measurements. The developed method is expected to be used as a tool to support a loss assessment system for determining the direction and priority of disaster response in the event of an earthquake.

초정밀 비구면 렌즈 금형가공시스템 개발 (Development of machining system for ultra-precision aspheric lens mold)

  • 백승엽;이하성;강동명
    • Design & Manufacturing
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    • 제2권1호
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    • pp.33-38
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    • 2008
  • As consumer in optics, electronics, aerospace and electronics industry grow, the demand for ultra precision aspherical surface lens increases higher. Precision turning with single-diamond tools has a long history of development for fabrication of optical quality surfaces since the advent of aerostatic rotary spindles and precise linear motion guide ways. To enhance the precision and productivity of ultra precision aspherical surface micro lens, the following specification of ultra precision grinding system is required: the highest rotational speed of the grinder is 100,000rpm and its turning accuracy is $0.1{\mu}m$, positioning accuracy is $0.1{\mu}m$. The development process of the grinding system for the ultra precision aspherical surface micro lens for optoelectronics industry is introduced. In the work reported in this paper, an intelligent grinding system for ultra precision aspherical surface machining was designed by considering the factors affecting the surface roughness and profiles accuracy. An aerostatic form was adopted to build the spindle of the workpiece and the spindle of grinder and ultra precision LM guide way was adopted in this system. And this paper deals with mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and spherical lens of BK7. It results was that a form accuracy of $0.6{\mu}m$ P-V and a surface roughness of $0.006{\mu}m$ Rmax.

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지역사회 선교도구로서의 교회평생교육 조망 (A View of Church Lifelong Education as a Community Missionary Tool)

  • 박수진;심지연;이복희
    • 기독교교육논총
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    • 제74권
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    • pp.209-225
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    • 2023
  • 연구 목적 : 평생교육에 대한 요구가 증대되고 있다. 개인과 조직 집단은 교육·학습 활동을 전개하면서 누구든지, 언제, 어디에서나 배울 수 있는 환경을 창출하고 있다. 한국 기독교의 전파 활동은 교육으로부터 시작되었다. 다양한 인적 자원과 물적자원 등을 소유하고 있는 교회는 지역에서의 그 기능과 역할이 더욱 중요시된다. 이에 본 연구에서는 지역사회에서 교회평생교육의 역할과 기능을 탐색하여 봄으로써 선교 도구로서의 교회평생교육을 조망하는 데 목적이 있다. 연구 내용 및 방법 : 교회평생교육의 의의, 교회평생교육에 대한 성경적 근거, 교회평생교육의 역사를 살펴본다(II장). 지역사회에서의 교회의 역할과 평생교육에 대한 교회의 기능적 근거를 검토한다(III장). 지역사회 선교 도구로서의 교회평생교육의 의미를 제시하고자 한다(IV장, V장). 결론 및 제언 : 교회평생교육 실천으로 지역사회 주민들은 교회에 대한 긍정적인 인식을 갖게 되었고, 교회는 전도 접점의 기회 제공이 되는 것을 알 수 있었다. 평생교육을 실행할 수 있는 다양한 장점들을 가지고 있는 교회가 이제는 지역선교를 위한 선교적 도구로서 교회평생교육을 활성화하는 것이 필요하다.

수학교과서의 스토리텔링 내용 분석 및 활용실태조사 - 고등학교 1학년 중심으로 - (A Content Analysis of Storytelling in Mathematics Textbooks & Research on the Actual Teacher-Student Condition centered on Senior High School)

  • 강옥선;김응환
    • 한국학교수학회논문집
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    • 제17권3호
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    • pp.337-358
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    • 2014
  • 교육과학기술부는 2012년 1월에 '수학교육 선진화 교육'을 발표하며 주요방향 및 과제로 '생각하는 힘을 키우는 수학', '쉽게 이해하고 재미있게 배우는 수학', '더불어 함께하는 수학'을 제시하며 '쉽게 이해하고 재미있게 배우는 수학'에 해당되는 내용으로 스토리텔링 기법을 적용한 교과서를 제시하였다. 본고에서는 2009 개정 교육과정에 따른 고등학교 1학년 수학I 교과서에 스토리텔링 기법을 어떻게 적용하였는지 분석해 보고, 고등학교 1학년 교사와 학생들의 스토리텔링에 대한 이해와 활용실태를 조사하고자 하였다.

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