• 제목/요약/키워드: material-independent

검색결과 744건 처리시간 0.024초

강소성 유한 요소 해석에 연계한 Rate-Independent 결정소성학을 이용한 3차원 알루미늄 압출재에서의 변형 집합 조직 예측 (Prediction of Texture Evolution of Aluminum Extrusion Processes using Rigid-Plastic Finite Element Method based on Rate-Independent Crystal Plasticity)

  • 김경진;양동열;윤정환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.485-488
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    • 2005
  • Most metals are polycrystalline material whose deformation is dominated by the slip system. During the deformation process, orientation of slip systems is rearranged with preferred orientations, leading to deformation-induced crystallographic texture which is called deformation texture. Depending on the texture development, the property of material can be changed. The rate-independent crystal plasticity which is based on the Schmid law as a yield function causes a non-uniqueness in the choice of active slip systems. In this work, to avoid the slip system ambiguity problem, rate-independent crystal plasticity model based on the smooth yield surface with rounded-off corners is adopted. In order to simulate the polycrystalline material under plastic deformation, we employ the Taylor model of polycrystal behavior that all the grains are assumed to be subjected to the macroscopic velocity gradient. Rigid-plastic finite element program based on this rate-independent crystal plasticity is developed to predict the grain-level deformation behavior of FCC metals during metal forming processes. In the finite element calculation, one integration point is considered as a crystalline aggregate which has a number of crystals. Macroscopic behavior of material can be deduced from the behavior of aggregates. As applications, the extrusion processes are simulated and the changes of mechanical properties are predicted.

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설비능력과 작업순서를 고려한 U-라인상에서의 셀 시스템 설계 (Operation-sequence-based Approach for Designing a U-shaped Independent-Cell System with Machine Requirement Incorporated)

  • 박연기;성창섭;정병호
    • 한국경영과학회지
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    • 제26권1호
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    • pp.71-85
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    • 2001
  • This paper considers a cost model for a U-shaped manufacturing cell formation which incorporates a required number of machines and various material flows together under multi-part multi-cell environment. The model is required to satisfy both the specified operation sequence of each part and the total part demand volume, which are considered to derive material handling cost in U-shaped flow line cells. In the model several cost-incurring factors including set-up for batch change-over, processing time for operations of each part, and machine failures are also considered in association with processing load and capacity of each cell. Moreover, a heuristic for a good machine layout in each cell is newly proposed based on the material handling cost of each alternative sequence layout. These all are put together to present an efficient heuristic for the U-shaped independent-cell formation problem, numerical problems are solved to illustrate the algorithm.

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종합병원 간호사의 간호권력 인식에 관한 연구 (A Study of Nursing Power Perception for Nurse in General Hospital)

  • 인경선
    • 한국보건간호학회지
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    • 제7권2호
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    • pp.67-76
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    • 1993
  • This study was conducted to investigate the nurses' recognition extent of nursing power and related factors. It was performed in a private university hospital using questionaire papers from Jul. 11 to Jul. 20, 1993. The collected data were in number of 209, and they were handled and analyzed by computer program (SPSS). Through above process, we got meaningful results as follow. 1. The factor concerned with whether the nursing department show its independent power or not was 4.1 on an average. Consequently above results showed that the independent power roles as a important factor. The factor concerned with study and research was 3.9 on an average. So that the extension of learning was also a comparatively important nursing power. But ensuring good material environment was merely 1.6 on an average. So it was understood as less important nursing power. 2. Between the factor concerned with enforcement of independence of nursing department and the factor concerned with extension of learning, there was positive correlation of 0.32 Pearson's Correlation Coefficent. It can be interpreted as the effort of extension of learning go side by side with the showing of independent power of nursing department. As a result the power of nursing become strong. And between the factor concerned with enforcenment of independence of nursing department and the ensuring o(good material environment, there was negative correlation of -0.28 Pearson's Correaltion Coefficint. It can be interpreted as the stronger the independent power of nursing, the more overlooked the recognized of material environment of nurses.

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독립제작사 제작 방송 다큐멘터리 소재의 유형화 : KBS 1TV <수요기획>을 중심으로 (Typological approach to Materials of TV Documentary Produced by Independent Production : Focused on KBS 1TV )

  • 이정우;강승묵
    • 한국콘텐츠학회논문지
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    • 제13권4호
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    • pp.104-114
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    • 2013
  • 본 연구는 디지털 방송 환경 하에서 독립제작사 제작 방송 다큐멘터리의 소재 유형을 다양화하고 전문화 함으로써 시청자의 시청 권리를 확대하는데 연구목적을 두고 있다. 이를 위해 독립제작사 제작 방송 다큐멘터리인 <수요기획>(KBS 1TV)의 지난 10년 간 방송분을 분석대상으로 방송 소재를 유형화했다. 연구결과에 의하면, 완전 공모제 방식의 외주제작 방송 다큐멘터리인 <수요기획>의 제작에 국내 대부분의 독립제작사들이 참여했고, 제작규모 면에서 영세한 독립제작사들이 완전 공모제 방식을 적극 활용해 제작해 온 것으로 나타났다. 방송 소재 유형을 9가지로 분류해 분석한 결과, 시사 소재 유형이 33.4%, 휴먼 소재 유형이 18.5%를 차지하고 있었으며 독립제작사의 수익 극대화를 위해 연작 형식이 채택되기도 한 것으로 분석되었다. 방송 다큐멘터리의 소재 유형화 과정을 분석한 본 연구는 독립제작사의 방송 다큐멘터리 소재 선정의 유형을 체계적으로 분석했다는데 연구의의를 찾을 수 있다.

The Overstrain of Thick-Walled Cylinders Considering the Bauschinger Effect Facto. (BEF)

  • Ghorbanpour, A.;Loghman, A.;Khademizadeh, H.;Moradi, M.
    • Journal of Mechanical Science and Technology
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    • 제17권4호
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    • pp.477-483
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    • 2003
  • An independent kinematic hardening material model in which the reverse yielding point is defined by the Bauschinger effect factor (BEF) , has been defined for stainless steel SUS 304. The material model and the BEF are obtained experimentally and represented mathematically as continuous functions of effective plastic strain. The material model has been incorporated in a non-linear stress analysis for the prediction of reverse yielding in thick-walled cylinders during the autofrettage process of these vessels. Residual stress distributions of the independent kinematic hardening material model at the onset of reverse yielding are compared with residual stresses of an isotropic hardening model showing the significant effect of the BEF on reverse yielding predictions. Critical pressures of direct and reverse yielding are obtained for the most commonly used cylinders and a range of permissible internal pressures for an efficient autofrettaged process is recommended.

Demonstration of Two Independent Dextranase and Amylase Active Sites on a Single Enzyme Elaborated by Lipomyces starkeyi KSM 22

  • LEE, SO-YOUNG;JIN-HA LEE;JOHN F. ROBYT;EUN-SEONG SEO;HYEN-JOUNG PARK;DOMAN KIM
    • Journal of Microbiology and Biotechnology
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    • 제13권2호
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    • pp.313-316
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    • 2003
  • Lipomyces starkeyi KSM 22 elaborates an enzyme that has both dextranase and amylase activities in a single protein of 100 kDa. Competition studies, using different amounts of dextran and starch as substrates, gave a competition plot consistent with the hypothesis that the hydrolysis of dextran and starch occurs at two independent active sites, each specific for starch and dextran, respectively.

Web기반 발전설비 정비관리시스템 개발 (The development of web based power plant maintenance management system)

  • 김범신;김의현;장동식;조재민;채길석;정규철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.2059-2063
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    • 2004
  • Most power plants have operated many independent computerize systems for maintenance. Independence of systems have caused complexity of business process and inconvenience of computer system management. Because the equipment and material master data is not standardize and structurize, it is difficult to manage equipment maintenance history and material delivery. Especially equipment classification criterion is important for standardization of every maintenance information. It is necessary to integrate function of independent systems for business process simplification and rapid work flow. this paper provides equipment classification criterion design and system integration method with the case of live system development.

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A topology optimization method of multiple load cases and constraints based on element independent nodal density

  • Yi, Jijun;Rong, Jianhua;Zeng, Tao;Huang, X.
    • Structural Engineering and Mechanics
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    • 제45권6호
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    • pp.759-777
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    • 2013
  • In this paper, a topology optimization method based on the element independent nodal density (EIND) is developed for continuum solids with multiple load cases and multiple constraints. The optimization problem is formulated ad minimizing the volume subject to displacement constraints. Nodal densities of the finite element mesh are used a the design variable. The nodal densities are interpolated into any point in the design domain by the Shepard interpolation scheme and the Heaviside function. Without using additional constraints (such ad the filtering technique), mesh-independent, checkerboard-free, distinct optimal topology can be obtained. Adopting the rational approximation for material properties (RAMP), the topology optimization procedure is implemented using a solid isotropic material with penalization (SIMP) method and a dual programming optimization algorithm. The computational efficiency is greatly improved by multithread parallel computing with OpenMP to run parallel programs for the shared-memory model of parallel computation. Finally, several examples are presented to demonstrate the effectiveness of the developed techniques.

초등수학 영재학생을 위한 독립연구 점검표 개발 및 적용 (A Development and Application of Independent Study Checklist for Mathematics Gifted Students)

  • 박정웅;이대현
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제18권2호
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    • pp.77-89
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    • 2015
  • 영재지도에 대한 지속적인 관심 속에서 '독립연구'가 영재학생들의 학습 양식에 부합하는 교육의 한 가지 형태로 주목을 받고 있다. 이에 본 연구에서는 초등수학 영재학생들의 '독립연구를 위한 점검표'를 개발하고, 이를 적용하여 학생들의 독립연구 산출물에 나타난 특징을 분석하였다. 독립연구 산출물에 나타난 특징을 분석한 결과, 첫째, '독립연구를 위한 점검표'가 학생 스스로 자신의 독립연구 과정을 확인할 수 있는 자기점검 체크리스트로서 역할을 하였다. 둘째, '독립연구를 위한 점검표'의 점검 내용은 영재학생들에게 토론 주제를 제시하여 풍부한 토론을 유도하였다. 셋째, '독립연구를 위한 점검표'는 영재 독립연구 지도교사에게 학생들의 특성에 부합하는 지도 자료로 활용될 수 있었다. 넷째, 학생의 연구주제 및 연구방법에 따라 '독립연구를 위한 점검표'는 선택적으로 활용될 수 있었다.