• 제목/요약/키워드: Concept Lattice

검색결과 103건 처리시간 0.025초

한국 전통목가구 평상(平床) 연구 2 - 평상을 적용한 모듈화 다용도 침대 개발 - (A Study on Traditional Korean Furniture, PyeongSang II - Developing Modularized and Multi-useful Bed adopting PyeongSang -)

  • 김민경;문선옥
    • 한국가구학회지
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    • 제28권3호
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    • pp.145-155
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    • 2017
  • This study explores developing a piece of modularized and multi-useful bed adapting PyeongSang followed by the last issue, 'a study on traditional Korean furniture, PyeongSang I' for the understanding of the furniture from theory and history. Adopted From the joints and ornament, the modularized elements were designed and developed in order to compose the head board, the side board, the foot board, and the seat bottom. The joints are sambang miter, samae miter, dado, and mortise and tenon, which are strong in holding the bed. And the ornament is lattice patterns like geokjamun and manjamun, elephant eyes patterns like ansangmun from the traditional furniture. Using the elements, the bed is composed with six modules which make people free and easy to move and transform them. Hence, the bed is multi-useful by using the double, the twin the single, and various sofas by the way to display them such as two, three, four, five, and six modules. And the bed was made of bright zelkova tree and dark heat treated ash expressing contrast of black and white, the design concept modern and easy to make many people access to them.

Core analysis of accident tolerant fuel cladding for SMART reactor under normal operation and rod ejection accident using DRAGON and PARCS

  • Pourrostam, A.;Talebi, S.;Safarzadeh, O.
    • Nuclear Engineering and Technology
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    • 제53권3호
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    • pp.741-751
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    • 2021
  • There has been a deep interest in trying to find better-performing fuel clad motivated by the desire to decrease the likelihood of the reactor barrier failure like what happened in Fukushima in recent years. In this study, the effect of move towards accident tolerant fuel (ATF) cladding as the most attracting concept for improving reactor safety is investigated for SMART modular reactor. These reactors have less production cost, short construction time, better safety and higher power density. The SiC and FeCrAl materials are considered as the most potential candidate for ATF cladding, and the results are compared with Zircaloy cladding material from reactor physics point of view. In this paper, the calculations are performed by generating PMAX library by DRAGON lattice physics code to be used for further reactor core analysis by PARCS code. The differential and integral worth of control and safety rods, reactivity coefficient, power and temperature distributions, and boric acid concentration during the cycle are analyzed and compared from the conventional fuel cladding. The rod ejection accident (REA) is also performed to study how the power changed in response to presence of the ATF cladding in the reactor core. The key quantitative finding can be summarized as: 20 ℃ (3%) decrease in average fuel temperature, 33 pcm (3%) increase in integral rod worth and cycle length, 1.26 pcm/℃ (50%) and 1.05 pcm/℃ (16%) increase in reactivity coefficient of fuel and moderator, respectively.

Freudenthal의 수학화 이론에 근거한 제 7차 초등수학 교과서 5-가 단계 넓이 단원의 재구성 (A Reconstruction of Area Unit of Elementary Mathematics Textbook Based on Freudenthal's Mathematisation Theory)

  • 유미현;강흥규
    • 한국초등수학교육학회지
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    • 제13권1호
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    • pp.115-140
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    • 2009
  • Freudenthal은 수학화를 핵심 개념으로 하는 현실주의 수학 교육론을 주창하였다. 수학화란 현실 안에 있는 여러 현상들을 수학적인 수단을 사용하여 조직함으로써 현실에 질서를 부여하는 활동을 말한다. 본 연구에서는 Freudenthal의 수학화 이론을 바탕으로 제 7차 초등 수학 교과서 5-가 단계의 넓이 단원을 재구성하여 실험적인 지도만을 작성한 다음, 이를 통하여 교수 실험을 실시함으로써, 수학화를 통한 넓이의 지도 방안의 효과와 더불어 학생들의 넓이 개념과 공식에 대한 이해 실태를 분석하였다. 그 결과, 넓이의 개념 이해 측면에서는 실험반 학생들이 우수하였으나, 넓이의 계산 측면에서는 유의미한 차이가 없는 것으로 나타났다.

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INTERGRANULAR CORROSION-RESISTANT STAINLESS STEEL BY GRAIN BOUNDARY ENGINEERING

  • Hiroyuki Kokawa;Masayuki Shimada;Wang, Zhan-Jie;Yutaka S. Sato
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.250-254
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    • 2002
  • Intergranular corrosion of austenitic stainless steels is a conventional and momentous problem during welding and high temperature use. One of the major reasons for such intergranular corrosion is so-called sensitization, i.e., chromium depletion due to chromium carbide precipitation at grain boundaries. Conventional methods for preventing sensitization of austenitic stainless steels include reduction of carbon content in the material, stabilization of carbon atoms as non-chromium carbides by the addition of titanium, niobium or zirconium, local solution-heat-treatment by laser beam, etc. These methods, however, are not without drawbacks. Recent grain boundary structure studies have demonstrated that grain boundary phenomena strongly depend on the crystallographic nature and atomic structure of the grain boundary, and that grain boundaries with coincidence site lattices are immune to intergranular corrosion. The concept of "grain boundary design and control", which involves a desirable grain boundary character distribution, has been developed as grain boundary engineering. The feasibility of grain boundary engineering has been demonstrated mainly by thermomechanical treatments. In the present study, a thermomechanical treatment was tried to improve the resistance to the sensitization by grain boundary engineering. A type 304 austenitic stainless steel was pre-strained and heat-treated, and then sensitized, varying the parameters (pre-strain, temperature, time, etc.) during the thermomechanical treatment. The grain boundary character distribution was examined by orientation imaging microscopy. The intergranular corrosion resistance was evaluated by electrochemical potentiokinetic reactivation and ferric sulfate-sulfuric acid tests. The sensitivity to intergranular corrosion was reduced by the thermomechanical treatment and indicated a minimum at a small roll-reduction. The frequency of coincidence-site-lattice boundaries indicated a maximum at a small strain. The ferric sulfate-sulfuric acid test showed much smaller corrosion rate in the thermomechanically-treated specimen than in the base material. An excellent intergranular corrosion resistance was obtained by a small strain annealing at a relatively low temperature for long time. The optimum parameters created a uniform distribution of a high frequency of coincidence site lattice boundaries in the specimen where corrosive random boundaries were isolated. The results suggest that the thermomechanical treatment can introduce low energy segments in the grain boundary network by annealing twins and can arrest the percolation of intergranular corrosion from the surface.

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신호 전송의 양과 질에서 위너의 MMSE와 샤논의 정보 이론적 정보량 극한 과 격자 코드 와의 만남 (Encounter of Lattice-type coding with Wiener's MMSE and Shannon's Information-Theoretic Capacity Limits in Quantity and Quality of Signal Transmission)

  • 박대철;이문호
    • 전자공학회논문지
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    • 제50권8호
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    • pp.83-93
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    • 2013
  • 통계적 신호 전송에 관한 위너의 MMSE와 정보이론 관점에서 처음으로 증명한 샤논의 상호 정보량을 비교함으로서 둘 사이의 관련성을 연구하였다. 위너가 신호 전송에서 보려했던 것은 잡음이 존재하는 채널에서 복원하려는 신호의 전송 품질의 근본적 극한(limit)를 계산해내려는 것이라 해석할 수 있다. 반면, 샤논은 엔트로피 개념을 적용하여 상호 정보에 대한 불확실성의 차를 최대화로 하는 전송 정보량의 근본적 상한(upper bound)의 극한(limits)을 계산을 계산하려는 것이라 해석할 수 있다. 본 논문의 관심은 샤논의 점 대 점 채널 용량의 근본적 극한을 계산하는 샤논의 공식을 유도함에 있어 위너의 최소 평균 자승 오차(MMSE) 컴바이너에 의한 최적 위너 필터를 사용했을 때 위너의 MMSE와 샤논의 상호 정보량이 미적분관계로 연결되어 있음을 확인하는 것이며, 위너 필터의 MMSE 와 샤논의 상호 정보량이 만나는 점에서 대역 효율성의 상한과 에너지 효율성의 하한을 계산하였다. mod-${\Lambda}$ AWGN 채널 모델에 의한 적절한 성형 격자 ${\Lambda}$의 선택과 ${\alpha}$의 MMSE 추정에 의해 격자형 부호 방식이 샤논의 원래 채널 용량 극한에 미치게 됨을 확인하였다.

Static analysis of a radially retractable hybrid grid shell in the closed position

  • Cai, Jianguo;Jiang, Chao;Deng, Xiaowei;Feng, Jian;Xu, Yixiang
    • Steel and Composite Structures
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    • 제18권6호
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    • pp.1391-1404
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    • 2015
  • A radially retractable roof structure based on the concept of the hybrid grid shell is proposed in this paper. The single-layer steel trusses of the radially foldable bar structure are diagonally stiffened by cables, which leads to a single-layer lattice shell with triangular mesh. Then comparison between the static behavior between the retractable hybrid grid shell and the corresponding foldable bar shell with quadrangular mesh is discussed. Moreover, the effects of different structural parameters, such as the rise-to-span ratio, the bar cross section area and the pre-stress of the cables, on the structural behaviors are investigated. The results show that prestressed cables can strengthen the foldable bar shell with quadrangular mesh. Higher structural stiffness is anticipated by introducing cables into the hybrid system. When the rise-span ratio is equal to 0.2, where the joint displacement reaches the minimal value, the structure shape of the hyrbid grid shell approaches the reasonable arch axis. The increase of the section of steel bars contributes a lot to the integrity stiffness of the structure. Increasing cable sections would enhance the structure stiffness, but it contributes little to axial forces in structural members. And the level of cable prestress has slight influence on the joint displacements and member forces.

프로세스 대수에서 이동성과 상호작용을 분석하기 위한 행위 온톨로지를 이용한 추상화 방법 (Abstraction Method for Analysis of Mobility and Interaction in Process Algebra Using Behavioral Ontology)

  • 우수정;온진호;이문근
    • 한국콘텐츠학회논문지
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    • 제11권9호
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    • pp.63-75
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    • 2011
  • 분산 이동 실시간 시스템을 개발하기 위해 pi-Calculus, Mobile Ambients Calculus, Bigraph 등의 수많은 프로세스 대수가 존재한다. 하지만 시스템이 방대해지고 복잡해질수록 시스템을 구성하는 프로세스들의 통신과 이동 역시 방대해지고 복잡해지므로 프로세스 대수로 이를 이해하는데 어려움이 존재한다. 그러므로 방대하고 복잡한 시스템을 체계적으로 이해할 수 있는 방법이 필요하다. 본 논문에서는 방대하고 복잡한 시스템을 프로세스들의 통신과 이동의 순서화된 추상화 방법 즉, 계층적으로 구조화된 격자(Lattice)들의 형태인 프리즘(Prism)으로 다룬다. 이는 액티브 온톨로지(Active Ontology)에서 확장된 새로운 개념인 행위 온톨로지(Behavior Ontology)를 기반으로 한다. 프리즘은 시스템을 체계적으로 이해하기 위해 시스템을 계층적으로 구성된 행위적 속성을 지닌 격자들 관점에서 분석하는 것을 허용한다. 이러한 방법은 통신과 이동의 복잡함을 의미적이고 계층적으로 구성된 행위의 구조로 체계적으로 이해할 수 있게 한다.

'그리드'(Grid)의 형성과 해체 -서양회화의 사적맥락과 그 해석을 중심으로 - (A Study on the Construction and Deconstruction of the 'Grid' : The Historical Context and Interpretation)

  • 김재관
    • 조형예술학연구
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    • 제1권
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    • pp.125-164
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    • 1999
  • The Grid, a lattice structure adapted in paintings, is one of thesimplest plastic structures based on the intersection of horizontal and perpendicular lines. Though mankind has, from the pre-history to the present day, put it to good use in everyday life as a traditional practice or a magical, esoteric, religious emblem in the case of the teciform of primitve art, it was in the paintings of Piet Mondrian that the Grid showed its modern, artistic transformation. As we suggest in the title, before I state the Grid as a plastic construction of modern painting, this dissertation inquires the Grid structure that extends over paintings through the ages as a painterly conept, especially focused on their formation and deconstruction. To begin with, my dissertation investigates, as a historical background, a general idea of the geometrical structure and phases of its transition in art, prior to dealing with the Grids as plastic strures in modern painting. the core of my study on formal Grids is permeated through the third chapter. The first chapter concentrates on, firstly, difining the notion of the Grid and geometrical structure, secondly, searching for a historical backgrounb with whict the so- called modern Grid-paintings come in, inquiring into the formation of the illusion-Grid as aresult of discovering the linear perpective and the situation of the conflict and reconciliaton between reality and illusion. Based on these considerations, the second cecond chapter will examine the various sitations of formation and adaptation of the paintery Grids in the Literalism-Grid, as we have already seen in the chapter one. And the cardinal third chapter devotes itself to the process of the formation of the so-called Object-Grid and Literal-Grid in the Literalism or Minimalism as its logical extension of the Painterly Grid. With it we can get to an interpretation and understanding of the meaning and qualites of Grid dwelt in Modernism thst transformed the structure of Painterly Grid originally as a plane concept to the third dimentionl structure. And then, the fourth chapter, we try to draw a new meaning andre-interpretation of the Formal-Grid as a representatuinnal structure appeared in the post-modernist paintings, going with its deconstructional situation. Therefore, we can, in our study on Grids, see the various points of view in the interpretation of them as illusion-structure, as plane-structure, and as cubic-structure; its concept differs form times, oscillating between its formation and deconstruction. The Grid, as we have seen in my dissertation, contains various problems and significations in art that deserve to investigate throughly, including some important plastic problem such as space and plane, and, in the case of do-grid, time. We may expect new concepts of it that will have difference meanings. 1 hope my study makes some contributions to understanding the coordination of the abstruse modern and contemporary art.

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개념 망 구조를 기반으로 한 문항 관리 시스템의 설계 및 구현 (Design and Implementation of a Question Management System based on a Concept Lattice)

  • 김미혜
    • 한국콘텐츠학회논문지
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    • 제8권11호
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    • pp.412-425
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    • 2008
  • 이-러닝을 통한 교육에 있어 학습자의 학업 성취도를 향상시킬 수 있는 중요한 요인 중의 하나는 다양한 평가문항을 제공하여 학습자가 원하는 주제의 문제들을 용이하게 검색하여 학습할 수 있도록 지원하는 것이다. 그러나 평가문항을 위한 시스템은 주로 구문해석에 기반 한 키워드 검색과 영역별 단원 중심의 계층적인 분류체계에만 의존하고 있어 영역별 연관 관계에 의한 통합된 유형의 문항 검색에는 어려움을 지닌다. 본 논문에서는 C언어 프로그래밍 학습을 위한 문항을 웹상에서 쉽게 관리하고 유지할 수 있는 더불어 관리된 문항들을 효과적으로 검색하여 활용할 수 있는 문항관리 및 검색 시스템을 설계하고 구현 하였다. 제안된 문항 검색 시스템은 사용자 질의가 가지는 의미로부터 문항간의 개념적 연관 관계에 의한 검색을 가능하게 함으로써 단일 주제의 문항뿐만 아니라 영역별 연관 관계에 의한 통합된 유형의 문항들을 편리하게 검색하여 학습에 활용할 수 있도록 하였다. 따라서 제안된 시스템은 교과의 기본적인 원리, 개념의 이해뿐만 아니라 종합적인 지식 활용 및 문제 해결 능력 향상을 지원하는 시스템으로 기대된다.

가공열처리에 의한 Alloy 600 재료의 결정립계특성 변화와 입계부식 및 1차측 응력부식균열 거동 (Grain Boundary Character Changes and IGA/PWSCC Behavior of Alloy 600 Material by Thermomechanical Treatment)

  • 김진;한정호;이덕현;김영식;노희숙;김근홍;김정수
    • 한국재료학회지
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    • 제9권9호
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    • pp.919-925
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    • 1999
  • 가공열처리에 의한 결정립계조절 개념을 이용하여 Alloy 600 재료의 결정립계특성과 부식특성을 조사하였다. 가공열 처리에 따른 결정립계특성 변화를 EBSP로 분석하였으며, 결정립계특성 변화가 입계부식 및 응력부식균열 거동에 미치는 영향을 평가하였다. 가공열처리 반복에 따른 각 단계에서의 CSL 입계의 분율 변화가 두드러지지는 않았으나, 상용재료에 비하여 CSL 분율이 약 10% 이상 향상된 결과를 얻었다. 결정립계특성 변화에 따라 입계부식 저항성이 현저하게 증가하였으나, 1차측 응력부식균열 특성에 있어서는 가공열처리를 반복할수록 파단시간과 최대하중이 감소하고 평균 균열성장속도가 증가하였으며 2차 균열이 억제되는 결과를 얻었다. 결정립계의 \`fine tuning\` 기구가 이러한 부식거동변화에 작용한 것으로 해석할 수 있었다.

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