• Title/Summary/Keyword: material-independent

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

  • Kim K.J.;Yang D.Y.;Yoon J.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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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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Operation-sequence-based Approach for Designing a U-shaped Independent-Cell System with Machine Requirement Incorporated (설비능력과 작업순서를 고려한 U-라인상에서의 셀 시스템 설계)

  • 박연기;성창섭;정병호
    • Journal of the Korean Operations Research and Management Science Society
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    • v.26 no.1
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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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A Study of Nursing Power Perception for Nurse in General Hospital (종합병원 간호사의 간호권력 인식에 관한 연구)

  • In Kyung Sun
    • Journal of Korean Public Health Nursing
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    • v.7 no.2
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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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Typological approach to Materials of TV Documentary Produced by Independent Production : Focused on KBS 1TV (독립제작사 제작 방송 다큐멘터리 소재의 유형화 : KBS 1TV <수요기획>을 중심으로)

  • Lee, Jung-Woo;Kang, Seung-Mook
    • The Journal of the Korea Contents Association
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    • v.13 no.4
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    • pp.104-114
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    • 2013
  • The purpose of this study is to expand the access rights of audience by diversifying and specializing types of material of TV documentary produced by independent production. To achieve this, we classified according to materials of . This research suggested that almost the whole independent production produced this documentary in the way of complete posting system, especially small production. Also as the result, to analysis nine types of materials, types of current affairs and human sources have the most to produce occupied 51.9% and independent production have maximized profits through a series of works. The research value of this study is that this study analyzed the types of material selection of TV documentary produced by independent production systematically.

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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    • v.17 no.4
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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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    • v.13 no.2
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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.

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

  • Kim, Bum-Shin;Kim, Eui-Hyun;Jang, Don-Sik;Cho, Jae-Min;Chae, Gil-Seok;Jung, Gyu-Chol
    • Proceedings of the KSME Conference
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    • 2004.04a
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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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    • v.45 no.6
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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.

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

  • Bak, Jeong Ung;Lee, Dae Hyun
    • Education of Primary School Mathematics
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    • v.18 no.2
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    • pp.77-89
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    • 2015
  • In this study, an 'Independent Study Checklist' for gifted mathematics students was developed and applied. The characteristics shown in the results after the 'Independent Study Checklist' was applied to mathematics gifted students were analysed. The checklist was divided into six phases of the independent study process and included checking contents at each stage. Observations, student interviews and results of the process of 'Independent Study' were collected and analysed to understand the characteristics of students' outcomes. The results from the application of the 'Independent Study Checklist' suggest the followings. First, the 'Independent Study Checklist' took the role of a self-check list to identify the process of the 'Independent Study'. Second, the check points of the 'Independent Study Checklist' presented the view of discussion to gifted students. Third, the 'Independent Study Checklist' was used as teaching material for teachers of gifted students. Fourth, 'Independent Study Checklist' was optionally used according student's study topics and method. Fifth, the checklist at each phase was continuously used during the whole process of 'Independent Study'. The teachers' interest and encouragement took the role of facilitating students' study process.