• 제목/요약/키워드: Nature Element

검색결과 473건 처리시간 0.025초

경계요소법을 이용한 사출성형금형 냉각시스템의 최적설계 (Optimum design of injection molding cooling system via boundary element method)

  • 박성진;권태헌
    • 대한기계학회논문집A
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    • 제21권11호
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    • pp.1773-1785
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    • 1997
  • The cooling stage is the very critical and most time consuming stage of the injection molding process, thus it cleary affects both the productivity and the part quality. Even through there are several commercialized package programs available in the injection molding industry to analyze the cooling performance of the injection molding coling stage, optimization of the cooling system has npt yet been accomplished in the literature due to the difficulty in the sensitivity analysis. However, it would be greatly desirable for the mold cooling system designers to have a computer aided design system for the cooling stage. With this in mind, the present study has successfully developed an interated computer aided design system for the injection molding cooling system. The CAD system utilizes the sensitivity analysis via a Boundary Element Method, which we recently developed, and the well-known CONMIN alforuthm as an optimization technique to minimize a weighted combination (objective function) of the temperature non-uniformity over the part surface and the cooling time related to the productivity with side constranits for the design reality. In the proposed objective function , the weighting parameter between the temperature non-uniiformity abd the cooling time can be adjusted according to user's interest. In this cooling system optimization, various design variable are considered as follows : (i) (design variables related to processing conditions) inlet coolant bulk temperature and volumetric flow rate of each cooling channel, and (ii) (design variables related to mold cooling system design) radius and location of each cooling channel. For this optimum design problem, three different radius and location of each cooling channel. For this optimum design problem, three different strategies are suffested based upon the nature of design variables. Three sample problems were successfully solved to demonstrated the efficiency and the usefulness of the CAD system.

DEVELOPMENT OF ANIMAL CELL EXPRESSION SYSTEM WHICH CONFERS POSITION-INDEPENDENT AND ENHANCED FOREIGN GENE EXPRESSION

  • Yoon, Yeup;Kim, Jong-Mook;Kim, Jung-seob;Oh, Sun-Mo;Kim, Jong-Il;Yoon, Jae-Seung;Baek, Kwang-Hee
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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    • pp.178-181
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    • 2000
  • In order to develop the novel gene expression system, we introduced new control elements which could influence the foreign gene expression in animal cells. When the foreign genes are introduced into the genome of higher eukaryotic cells, the expressions from these integrated genes are often low and can vary greatly depending on the positions of the integration sites due to the complex nature of the chromatin structures (1). First we screened the various DNA sequence elements which can function as an insulator of gene expression from these position effects and can cooperate with the SV40 enhancer/promoter. Among the several DNA elements from the various sources, we identified the particular DNA element which confers the increased frequency of the positive colonies, assayed by the reporter gene from stable selections indicating significantly reduced position effects. This element also showed the several fold-increased expression level as well as the copy-number dependent expression with host cell specificity. Second we modified the transcription termination element where we introduced the specific terminator in combination with SV40 polyA signal. This modified terminator showed the increased efficiency and the level of the gene expression. By combining these two elements, we made the animal cell expression system and tested successfully for the recombinant protein productions of TGF ${\beta}$-soluble receptor, Antithrombin III, and single chain Pro-Urokinase. [Supported by grants from MOCIE]

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암반균열망-개별요소법 수치실험을 통해 살펴본 스웨덴 포쉬마크지역 암반의 역학적 및 수리적 물성에 초기응력이 미치는 영향 (The DFN-DEM Approach Applied to Investigate the Effects of Stress on Mechanical and Hydraulic Rock Mass Properties at Forsmark, Sweden)

  • 민기복;우베 스테판손
    • 터널과지하공간
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    • 제21권2호
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    • pp.117-127
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    • 2011
  • 균열암반의 역학적 및 수리적 성질에 암반 초기응력이 미치는 영향을 고찰하였다. 지질 데이터는 스웨덴 원전원료 및 방사성 폐기물 관리회사(SKB)에 의해 수행된 포쉬마크지역의 부지조사로부터 획득되었으며 암반균열망-개별요소법 수치실험(Discrete Fracture Network - Discrete Element Method) 을 통하여 암반의 등가역학적 및 등가수리적 물성을 결정하였다. 수치실험결과 균열 강성의 응력의존성, 균열 방향에 따른 상이한 변형거동, 균열거동에 따른 수리유동 경로의 변화 등의 원인에 의하여 등가역학적 및 등가수리적 물성은 응력의존성이 큰 것을 확인하였다. 본 연구의 결과는 암반 초기응력의 정확한 예측이 특정 부지에서의 경계조건으로서뿐만 아니라 균열암반의 역학적 및 수리적 물성을 이해하는 데도 중요한 역할을 한다는 것을 보여준다.

천공사진(天空寫眞)을 이용한 도시경관의 분석 및 평가 (An Analysis and Evaluation of Urban Landscapes Using Images Taken with a Fish-eye Lens)

  • 한갑수;윤영활;조현길
    • 한국조경학회지
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    • 제33권4호
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    • pp.11-21
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    • 2005
  • The purpose of this study was to analyze and evaluate landscape characteristics by classification of landscapes in Chuncheon. A system was developed to convert images taken with a fish-eye lens to panoramic pictures. Landscape characteristics were analyzed by appearance rate and area distribution rate of landscape elements on panorama picture. Landscape characteristics were analyzed according to the number of times landscape elements appeared and the amount of area that each element occupied in the panoramic picture. Each panoramic picture was classified into five types based on these landscape element factors. Landscape evaluation was carried out using dynamic images converted from picture by fish-eye lens. The results of this study can be summarized as follows. The urban landscape can be characterized by four essential factors: interconnectedness, nature, urban centrality and landscape scale. Five types of landscapes were determined: detached residential building landscape (type 1), street landscape with various elements (type 2), street landscape in the center of a city (type 3), landscape of housing complex (type 4), and landscape of green space (type 5). Type 5 had the highest degree of landscape satisfaction and the landscape satisfaction increased with the number of appearances of natural elements. The amount of peen space had a high relation with a landscape satisfaction.

적분형 르장드르 형상함수를 이용한 단일 수준 적응적 hp-체눈 세분화 (Single Level Adaptive hp-Refinement using Integrals of Legendre Shape Function)

  • 조준형;유효진;우광성
    • 한국전산구조공학회논문집
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    • 제23권3호
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    • pp.331-340
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    • 2010
  • 적응적 hp-세분화 기법과 그 기법의 효과적인 구성방법을 포함한 새로운 적응적 유한요소 알고리즘의 기초이론 및 적용이 이 연구를 통해 제시되었다. 적응적 hp-세분화 기초의 유한요소기법은 적분형 르장드르 형상함수와 요소별로 불균등한차수의 분배 및 비정형적인 절점연결과 관련된 연속조건을 만족시킬 수 있는 제약조건을 필요로 한다. 따라서 요소간의 접합부분에서 적응적 hp-유한요소망의 연속성이 중요한 문제로 대두된다. 이러한 문제를 요소경계에 연속성 제약조건을 절점연결 사상행렬을 적용하여 해결하였다. 또한, 적분형 르장드르 형상함수의 계층성질을 이용하여 제시된 알고리즘의 효율적 정식화 방안을 제시하였다. 간단한 캔틸레버문제가 h-세분화, p-세분화 그리고 hp-세분화 방법에 의해 계산되었다. hp-세분화의 결과는 다른 방식의 세분화에 비해 보다 빠른 수렴성을 보여 주는 것이 확인되었다. 그러므로 제시된 hp-세분화 알고리즘은 실제문제에 효율적으로 적용될 수 있을 것으로 생각된다.

램프(Ramp)의 공간적 유형과 특성에 관한 연구 (A Study on the Spatial types and characteristics of Ramp)

  • 이선영;이형근
    • 한국실내디자인학회논문집
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    • 제16권3호
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    • pp.38-45
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    • 2007
  • In the architectural space of modem age, expanding to the vertical and horizontal direction for the interaction between space and space is becoming an indispensable factor, and in this expansion, ramps are being positioned as one of the important factors. With an increased use of ramps, they show a variety of changes in types, functions and even concepts. The space where modem ramps are used exhibits a phenomenon that accommodates and expands many functions as well as the confined function of moving people, and is widening the scope of recognition on the functions of ramp. In addition, this phenomenon can be seen as an architectural reflection on the complexation trend of the modem society, the components comprising a ramp contact the body of experiencers closely and thus have a direct effect on their behavior or feeling, and owing to this, it is a space where new functions and meaning are highly likely to be derived. In this study, spaces where ramps are used stay away from an element of uniform vertical movement but have an independent environment within the entire space, thereby being used as a space dominating the nature of the building, not a subsidiary element of it. In this study, therefore, it could be known that spaces in which ramps are used are different in their meaning according to the patterns, not as an element of uniform vertical movement. In addition, these conclusions are the results by analyzing the patterns of ramps taking place in modem spaces and are thought to be helpful in understanding spaces where ramps are used.

동무(東武)의 "대학(大學)" 팔조목(八條目)에 대한 견해 고찰(考察) (A Study on Dongmu's Thoughts about the Eight Items of "The Great Learning(Ta hsueh)")

  • 이준희;이의주;송일병;고병희
    • 사상체질의학회지
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    • 제20권3호
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    • pp.1-13
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    • 2008
  • 1. Objectives This study was purposed to find Dong's thoughts about the eight items of the "The Great Learning(Ta hsueh)" 2. Methods It was researched through comparative and overall study on the Dong-mu's thoughts in "Gyukchigo(格致藁)" 3. Results (1) Dongmu reinterpreted the eight items of the "The Great Learning(Ta hsueh)" as the relations between the subject and the object from the ontologic assumption of Affairs Mind Body Objects as the principle of existence and correlation, summarized into four categories, and classified into the individual and subjective affairs, and the universal and objective affairs. The four categories of the eight items of the "The Great Learning(Ta hsueh)" are correlated with the individual and the universal ethics of behavior, and connected with the element for overcoming the individual inclination of mind and wickedness. (2) After the individual and subjective human was established, the eight items of the "The Great Learning(Ta hsueh)" were classified into two categories, and coupled up with each two items('Being sincere in their thoughts' with 'Extending to the utmost their knowledge', 'Rectifying their hearts' with 'Investigating things', 'Cultivating their persons' with 'Illustrating illustrious virtue throughout the kingdom', 'Regulating their families' with 'Ordering their own states'). Being based on this, 'Being sincere in their thoughts', 'Rectifying their hearts', 'Cultivating their persons' and 'Regulating their families' were understood as four individual and subjective human-basic-essential activity. Especially, mind, heart, body and family(power) were regarded as the four basic element in human existence and activity, and in correlation with universe and society, set up as the subjective element in Dongmu's epistemology, theory of nature and emotion, theory of morality and theory of moral cultivation.

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Constrained Delaunay Triangulation 균열 요소 생성 기법을 이용한 균열 해석 (Crack Analysis using Constrained Delaunay Triangulation Crack Mesh Generation Method)

  • 김연희;김연희;박정선
    • 항공우주시스템공학회지
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    • 제18권3호
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    • pp.17-26
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    • 2024
  • 항공기 엔진은 비행 중 고온, 고압과 터빈 축의 회전으로 인한 응력이 발생한다. 이러한 하중으로 인해 구조 내/외부에 미세한 균열이 발생할 수 있다. 이는 구조적 결함으로 이어져 부품의 수명에 악영향을 줄 수 있다. 이러한 현상을 사전에 방지하고자 균열에 대한 유한요소해석이 진행된다. 하지만 이 과정은 반복적인 균열 모델링이 이루어져 많은 시간과 노력을 수반한다. 그러므로 본 논문에서는 유한요소모델 기반의 균열 모델링 기법을 개발하였다. 균열 모델링에는 점 간의 연결에 제한을 가지고 공간을 삼각 분할하는 Constrained Delaunay Triangulation(CDT)을 사용하였다. 반타원 균열을 가지는 평판과 원통형 용기에 대한 응력확대계수 비교를 통해 기법을 검증하였으며, 균열 해석에 유용함을 보였다.

한국 전통마을의 공간구성 재론(再論) (Reconsideration of the Spatial Composition of the Korean Traditional Village)

  • 김기덕
    • 역사민속학
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    • 제57호
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    • pp.197-228
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    • 2019
  • 본 논문은 기존 연구에서 전통마을의 공간구성을 분류한 연구들을 일별해 보고, 그것들을 보완하여 새롭게 전통마을의 공간구성과 속성을 정리하였으며, 다음으로는 새롭게 정리된 공간구성 분류에 맞추어 기존연구를 활용하되 필자가 강조하고자 하는 사항을 보안하여 한국 전통마을의 공간 구성을 재론한 것이다. 먼저 전통마을의 공간구성으로 ①자연공간 ②주거공간 ③생업공간 ④이동공간 ⑤경계공간 ⑥놀이공간 ⑦제의공간의 7가지를 추출하였다. 그리고 그것을 기본성격에 맞추어, ①마을입지의 기본 공간 : 자연공간 ②자연공간 하에서 요청되는 필수 생존공간 : 주거공간 및 생업공간 ③마을 구성원 상호소통망에서 파생된 관계공간 : 이동공간 및 경계공간 ④장(場)의 개념으로 확산되는 가변공간: 놀이공간 및 제의공간의 4개 요소로 다시 제시하여 서술하였다. 사람이 만든 공간은 사람들의 삶을 담는 그릇이다. 그 그릇이 편리하고 쓰임새 있는 그릇이 되기 위해서는 삶의 틀에 맞추어진 것이어야 한다. 우리의 전통마을의 공간구성은 구성원들의 자연관·생활양식·세계관이라는 삶의 틀에 잘 구현되어 있었다. 자연관은 마을 공간구성 전체에 작용하지만 특히 자연공간에 잘 반영되어 있다. 생활양식은 주거공간·생업공간·이동공간·놀이공간에, 그리고 세계관은 경계공간·제의공간에 특색있게 반영되어 있다. 이러한 모든 것들을 유기적으로 작동시키기 위하여 공동체적 규약이 있었다.

A Study on Automated Bluetooth Communication Testing Methods Using CSR8670 Chip

  • Kim, Young-Mo;Noh, Hyun-Cheol;Kim, Seok-Yoon
    • 한국컴퓨터정보학회논문지
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    • 제21권5호
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    • pp.65-71
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    • 2016
  • Bluetooth technology(BT) is a standard for short distance wireless communication and widely used to connect and control various electronic and telecommunication devices without wires, where CSR8670 chip is generally adopted. These BT devices are required to comply with BT specification and the equipments for conformance test are also important. However, the existing BT testing methods have inconvenience in that they are mostly time-consuming procedure due to not only repetitive execution for each evaluation element but also error-prone nature of manual experiments. This paper proposes an automated BT communication test method using CSR8670 chip, which solves the problems related to manual testing methods. The proposed method can reduce the development period of BT products and guarantee the quality improvement owing to the exact system error detection capability.