• 제목/요약/키워드: Main component

검색결과 2,149건 처리시간 0.065초

초등학교 사회과의 환경 문제 해결과정 분석 및 수업 모형 개발 연구 - 환경 정의 개념을 중심으로 - (A Study on the Analysis of Environmental Problem Solving Process on the Elementary School Social Studies and Development of Instruction Model - Focus on the Environmental Justice -)

  • 장호창;남영숙
    • 한국환경교육학회지:환경교육
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    • 제20권4호
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    • pp.84-96
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    • 2007
  • The purpose of this study is to develop instruction model of environmental problem process focused with environmental justice. This study has analyzed environmental problem solution process in social studies of elementary school from 4th grade to 6th grade with it. The results of this study are as follows. First, social studies of elementary school didn't show distributive justice in environmental problem solving process. Second, procedural justice existed, but offered information is lacking to each main group. Third, substantive justice was emphasized personal viewpoint. We developed instruction model of environmental problem solving process based upon the results. Component of instruction model is problem analysis, distributive justice, procedural justice, substantive justice and evaluating a solution. Timely, teachers can use and can apply it in social studies class. In conclusion, it is strongly recommend to teach environmental education linked with environmental justice. It enables us enhance a new awareness and attitudes towards sustainable development.

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Analysis of post-failure response of sands using a critical state micropolar plasticity model

  • Manzari, Majid T.;Yonten, Karma
    • Interaction and multiscale mechanics
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    • 제4권3호
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    • pp.187-206
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    • 2011
  • Accurate estimations of pre-failure deformations and post-failure responses of geostructures require that the simulation tool possesses at least three main ingredients: 1) a constitutive model that is able to describe the macroscopic stress-strain-strength behavior of soils subjected to complex stress/strain paths over a wide range of confining pressures and densities, 2) an embedded length scale that accounts for the intricate physical phenomena that occur at the grain size scale in the soil, and 3) a computational platform that allows the analysis to be carried out beyond the development of an initially "contained" failure zone in the soil. In this paper, a two-scale micropolar plasticity model will be used to incorporate all these ingredients. The model is implemented in a finite element platform that is based on the mechanics of micropolar continua. Appropriate finite elements are developed to couple displacement, micro-rotations, and pore-water pressure in form of $u_n-{\phi}_m$ and $u_n-p_m-{\phi}_m$ (n > m) elements for analysis of dry and saturated soils. Performance of the model is assessed in a biaxial compression test on a slightly heterogeneous specimen of sand. The role of micropolar component of the model on capturing the post-failure response of the soil is demonstrated.

지역별 수산업 클러스터 형성가능성 검토 (Examining the Potentialities for Building Fisheries Cluster in Regional Level)

  • 최성애;채동렬
    • 수산경영론집
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    • 제40권3호
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    • pp.1-28
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    • 2009
  • In recent, the Korean fisheries industry face an overall crisis. Annual fish catch is continuously decreasing for last two decades even though various programs to improve fish population. Moreover, domestic fish market is more and more occupied by imported cheap fish products from abroad due to the consequence of open economic policy, FTA and WTO/DDA entente. Under the circumstances, this study aims to examine the potential for building fisheries cluster as a policy tool to promote fisheries and fisheries-associated industries in Korea. To achieve this goal, the authors firstly reviewed the theoretical concept of Industrial Cluster in the evolutionary economics point of view, secondly, analyzed the main components of Porterian Cluster(or innovation cluster), thirdly, derived the key reasons to induce the improvement of productivity within the cluster network system and lastly evaluated fisheries capability and industrial infrastructures of each province as a basic condition to build a fisheries cluster. The result of the study demonstrates the voluntary accumulation of fish products and processing techniques in Korea, however, it is not enough to make up a Porterian innovation. Therefore, the present is most opportune for applying fisheries cluster as a strategic policy tool. Government supports to establish innovation cluster for fisheries may contribute both fisheries industry and local economy by developing the latent capacity of fisheries and helping concentrate innovation capabilities.

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액체로켓엔진에서 입구압 변화에 따른 엔진 성능 변화 고찰 (A Study of Transitional Performance with Change of Inlet Pressure in Liquid Propellant Rocket Engine)

  • 문윤완;박순영;설우석
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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    • pp.103-106
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    • 2008
  • 본 연구에서는 발사체 비행 중 가속도의 변화로 발생하는 엔진 입구압력의 변화를 고려하여 엔진의 구성품에 미치는 영향을 고찰하였고 그에 따른 엔진 성능 변화를 예측하였다. 엔진의 입구압은 탱크 내의 추진제 수두와 가압 압력 및 압력 손실 등으로 정의되며 이에 따라 발사체가 비행하면서 추진제 소모와 가속도 변화에 의해 입구압력이 변하게 된다. 입구압이 변할 때 펌프 토출압이 변하고 그에 따른 유량 변화로 가스발생기의 압렵변화가 발생하며, 이는 터빈의 출력변화로 이어져 다시 펌프의 토출압 변화로 나타남을 알 수 있었고, 이는 궁극적으로 주연소실의 연소압 변화를 이끌면서 엔진의 성능이 변화함을 알 수 있었다.

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Magnetic field characteristics from HTS quadruple magnet of in-flight separator for a heavy ion accelerator

  • Zhang, Zhan;Lee, Sangjin;Jo, Hyun Chul;Kim, Do Gyun;Kim, Jongwon
    • 한국초전도ㆍ저온공학회논문지
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    • 제17권3호
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    • pp.23-27
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    • 2015
  • Quadruple magnet is an essential component for the accelerator, and the field uniformity in the good field region reflects the quality of quadruple magnet. In this paper, the total magnetic field B was separated into the coil-induced magnetic field $B_s$ and the iron-induced magnetic field $B_c$ to explain why the total magnetic field B has some inhomogeneity. Using Fourier analysis, harmonic components of $B_s$, $B_c$ and B have been analyzed at good field region, respectively. The harmonics of multipole magnet and Fourier analysis are helpful to show the uniformity of magnetic field. Several geometries of yoke and coils were defined to analyze the effect on field uniformity of an HTS quadruple magnet. By the analysis, it was found that the sixth harmonics which is the main factor of field inhomogeneity can be reduced to zero. It means that the sixth harmonics of the magnetic field B can be removed by adjusting the geometry of the magnet pole and the position of coils. We expect that this result can effectively improve the uniformity of an HTS quadruple magnet.

한국산 마늘에 의한 Aspergillus parasiticus의 성장 억제 효과 (Inhibitory Effect of Garlic on the Growth of Aspergillus parasiticus)

  • 박정영;김종규
    • 한국환경보건학회지
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    • 제35권2호
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    • pp.95-99
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    • 2009
  • This study was performed to investigate the possible effect of garlic produced in Korea on the inhibition/reduction of growth of A. parasiticus, a toxigenic strain. The effect was studied using different concentrations of freeze-dried garlic in potato-dextrose agar (PDA) and/or in yeast-extract sucrose (YES) broth at $25^{\circ}C$ for 15 days. While inhibition of the fungal growth due to increasing the concentration of garlic was observed, the more remarkable effect was observed on the ninth day. Reduction of fungal diameter as a result of addition of garlic on PDA was observed to range between 3.4% to 20.1 % while reduction of mycelial weight in YES broth ranged from 9.9% to 30.5%. The 0.5% and 1.0% concentrations of garlic significantly reduced fungal diameter in PDA on the 9th day, while 0.1 %, 0.5%, and 1.0% concentrations of garlic significantly reduced the mycelial weight in YES broth (p<0.05). Dose-response relationships were observed between the concentration of garlic and inhibition of growth both in solid culture and in liquid culture. This study indicates that garlic could be an effective inhibitor at a human consumption level of the growth of A. parasiticus. More research is needed to study the inhibitory effects of the main active component of garlic.

사각기둥의 전면 부가구조물 설치로 인한 입사붕괴파의 충격력 완화 효과 (Mitigation Effects of Incident Bore Impact Loads Acting on a Tall Structure by Installation of Obstacles)

  • 이병혁;황성철;박종천
    • 한국해양공학회지
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    • 제27권1호
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    • pp.93-101
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    • 2013
  • The incident bore impact loads acting on a tall structure is simulated using the refined Moving Particle Simulation (MPS) method. The particle method is more feasible and effective than conventional grid-based methods for the violent free-surface problems. In the present study, the simulation results for the temporal change of the hydrodynamic force on the structure and longitudinal velocity component around the structure are compared with the experiments (Radd and Bidoae, 2005). And the mitigation effects by installation of various obstacles in front of the main structure are investigated and discussed form the simulation results.

아치구조물의 모의지진파 입력에 따른 지진응답특성에 관한 연구 (A Study on the Seismic Response of Arch Structures Using Artificial Earthquake Ground Motions)

  • 정찬우;박성무;강주원
    • 한국공간구조학회논문집
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    • 제8권6호
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    • pp.59-66
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    • 2008
  • 대부분의 대공간구조물은 극장, 스타디움, 체육관 등 공공성을 가지게 되어 내진안전성에 있어서 중요성이 많이 인식되고 있다. 그러나 구조형식 및 형상에 관하여 다양성을 가지고 있는 대공간구조물이 동적하중인 지진하중을 받을 때 나타나는 구조물의 거동은 파악하기 힘들다. 본 논문에서는 대공간구조의 주 구조요소인 아치구조물에 대하여 고유진동모드를 검토하였고 모의지진파를 입력하여 지진거동특성을 분석한 결과로서 아치구조물은 설계가속도스펙트럼의 크기보다 장주기 성분에 더 많은 영향을 받는다는 것을 파악하였다.

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Fuzzy Relational Method를 이용한 CLINAID의 Knowledge Source 신뢰성 조사 (Investigation of the Reliability of Knowledge Source in CLINAID using Fuzzy Relational Method)

  • 노찬숙
    • 한국지능시스템학회논문지
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    • 제13권2호
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    • pp.222-230
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    • 2003
  • 의료 시스템이 개발되면 시스템이 사용하는 knowledge source의 신뢰도가 시스템의 수행능력에 큰 영향을 미치게 되므로, knowledge source의 신뢰도를 검증해야한다. 본 논문은 의료 시스템 CLINAID의 knowledge source의 신뢰성 조사에 대한 연구의 방법과 결과를 발표하였다. 그 방법으로는 CLINAID에 사용된 Cardiovascular body system 데이터에 fuzzy relational method를 적용하여 구조적 분석을 통해 만들어진 인공의 syndrome을 knowledge base에 저장되어있는 의료 전문가의 syndrome과 비교하였다. 7 가지 fuzzy implication operator를 사용하여 거의 비슷한 결과들을 산출해 냈으며, 그 결과들이 전문가가 제공한 syndrome과 거의 일치하였다.

초등학생을 위한 유한상태 오토마타 교육자료 개발 (Development of Finite State Automata Learning Materials for Elementary School Students)

  • 고형철;김종우
    • 정보교육학회논문지
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    • 제20권4호
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    • pp.401-408
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    • 2016
  • 언플러그드교육은 초등학교에서 실시하려는 SW교육의 주된 요소로 제시되고 있다. 이 자료는 Timbell 외 2가 제작한 컴퓨터과학에 대한 여러 가지 주제별로 자료를 제시하고 있다. 이들 중에 유한상태 오토마타 교육은 우리의 실정에 적합한 교수법과 교육자료의 개발이 필요하다. 본 연구에서는 이 주제와 관련된 선행 연구를 바탕으로 초등 고학년의 발달단계에 적합한 자료를 개발하였다. 학습모형은 학습자의 자기주도적 활동중심학습으로 구성하였으며, 제시된 교육자료와 교수법은 전문가 집단의 검증과 실험집단의 분석을 통해 적절하다는 결론을 얻었다.