• 제목/요약/키워드: Shape understanding

검색결과 575건 처리시간 0.03초

TIG 용접에서 열유속이 용융효율과 용입형상에 미치는 영향 (Effect of Heat Flux on the Melting Efficiency and Penetration Shape in TIG Welding)

  • 오동수;조상명
    • Journal of Welding and Joining
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    • 제27권2호
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    • pp.44-50
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    • 2009
  • The characteristics of arc pressure, current density and heat flux distribution are important factors in understanding physical arc phenomena, which will have a marked effect on the penetration, size and shape of a weld in TIG welding. The purpose of this study is to find out the effect of the heat flux on the melting efficiency and penetration shape in TIG welding using the results of the previous investigators. The conclusions obtained permit to draw a proper method which derived the heat flux distributions by arc pressure distribution measurements, but previous researchers calculated heat flux and current distribution with the heat intensity measurements by the calorimetry. Heat flux of Ar gas arc was concentrated at the central part and distributed low from the arc axis to the radial direction, that of He mixing arc was lower than that of Ar gas, and it was wide distributed to radial direction. That showed a similar characteristic with the Nestor's by calorimetry calculated values. Throughout heat flux drawn in this study was discussed melting efficiency and penetration shape on Ar gas and He mixing gas arc.

3차원 인제 형상 데이터를 이용만 목밑둘레 유형화 연구 - 20대 여성을 중심으로 - (A Study on the Classification of Neck-Base Circumference by Three-Dimensional Automatic Measurements of the Human Body - With the Focus on Women in their 20's -)

  • 조신현;석혜정
    • 복식
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    • 제58권6호
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    • pp.35-41
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    • 2008
  • The purposes of this study lied in the analysis and classification of neck-base circumference shapes of the women in their twenties, by the application of three-dimensional automatic measurement data of human body, and thereby in the understanding of neck-base circumference shapes by the classified type. The findings are as follows: 1. The comparison of three-dimensional human body measurement items relating to the neck-base circumference part of the women in their twenties indicated that the largest individual difference was found in cervicale-center-anterior neck radius than in other items. 2. The factor analysis, which was conducted to extract the factors constituting the neck-base circumference, showed the shape of cervicale(factor 1), the shape of section neck(factor 2), the thickness of neck(factor 3), the shape of anterior neck(factor 4), and the shape of side neck(factor 5). 3. The classification of the neck-base circumference shapes resulted in three types. Type 1 was the shape of a reverse triangle hanging forward, Type 2 was that of a circle, and Type 3 was that of an oval open to the sides.

탄소섬유 복합재료를 적용한 ANG 연료용기의 최적 형상설계 (Optimal Shape Design of ANG Fuel Vessel Applied to Composite Carbon Fiber)

  • 김건회
    • 한국기계가공학회지
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    • 제18권1호
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    • pp.65-71
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    • 2019
  • The development of adsorbed natural gas (ANG) has emerged as one of potential solutions. It is desirable to reduce the weight of vessel by applying light-weighed a composite carbon fiber in order to response to a egulation of $CO_2$ emission. Through understanding of a composite carbon fiber, and material characteristic of a composite carbon fiber is required in order for better application of a reduction of weight and an analysis of material characteristic. Herein, this study suggest the composite carbon fiber vessel applied to the characteristic of carbon fiber, and it decides the preliminary shape based on the test of material characteristic for ANG vessel applied to a composite carbon fiber, and its basic shape calculate through on the netting theory. Moreover, the detail shape design is analyzed by a finite element analysis, and in the stage of detail sahp design and analysis of stress was performed on the typical shape using a finite element analysis, and the result of preliminary design was verified.

미용 괄사요법을 이용한 체형 변화 연구 - 상반신을 중심으로 - (Study on body shape changes by Meridian Scraping - focused on upper part of the body -)

  • 문미진;김경희
    • 패션비즈니스
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    • 제12권4호
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    • pp.15-27
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    • 2008
  • The purpose of this study is to show data for protocol design which will be able to change body shape using the measured value before and after Meridian Scraping Massage with the Martin-type anthropometer through experiment result and questionnaire. The data analysis was done by paired-sample t-test using SPSS program and today, Meridian Scraping Therapy is being applied by various instruments which use meridian pathway and spots on the body suitable for acupuncture which promote blood circulation by eliminating toxin and maintaining body fluids balance. And they have such merit as easy to buy material and perform operation without side effect only if understanding massage principal.

시뮬레이션 모형을 이용한 도시 개발형태 및 경관의 변화 예측 (Prediction of Urban Development and Cityscape with a Simulation Model)

  • 이인성;김충식
    • 한국조경학회지
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    • 제32권3호
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    • pp.106-113
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    • 2004
  • The shapes(mass) of buildings are determined by many interrelated factors, such as planning and building regulations, the size and shape of building parcels, and adjoining road conditions. Understanding the effects of the determinants on the building shapes is not a simple task because of the multiplicity and complex interrelationships of the determinants. This study developed a prototype of three dimensional computer model that can simulates the determination process of building shape using GIS and CAD techniques. A commercial block in the south of Seoul was selected for the case study. Several methods of building height control were applied, and their effects on the cityscape were evaluated. The results shows that the three dimensional computer modelling offers an effective means for evaluating the effects of planning and building regulations. The implication of the case study and future research directions were discussed.

Variability in mechanical properties and microstructure characterization of CuAlBe shape memory alloys for vibration mitigation

  • Casciati, Fabio;van der Eijk, Casper
    • Smart Structures and Systems
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    • 제4권2호
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    • pp.103-121
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    • 2008
  • Shape memory alloys (SMA) have been emphasized, studied and understood in the controlled world of the laboratory. Any attempt to implement one of these alloys in engineered products requires a jump from the controlled world of the laboratory to the actual environment of the application. The first step is to move from single grain specimens to multigrain samples. One works with a material for which any stock is different from that previously available. This paper reviews the milestones in the familiarization process the authors had to overcome during their cooperation within a project funded by the European Union. The main items cover transformation temperatures, thermal treatment and properties understanding.

Coupling shape-memory alloy and embedded informatics toward a metallic self-healing material

  • Faravelli, Lucia;Marzi, Alessandro
    • Smart Structures and Systems
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    • 제6권9호
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    • pp.1041-1056
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    • 2010
  • This paper investigates the possibility of a strategy for an automatic full recover of a structural component undergoing loading-unloading (fatigue) cycles: full recover means here that no replacement is required at the end of the mission. The goal is to obtain a material capable of self healing earlier before the damage becomes irreversible. Attention is focused on metallic materials, and in particular on shape memory alloys, for which the recovering policy just relies on thermal treatments. The results of several fatigue tests are first reported to acquire a deep understanding of the physical process. Then, for cycles of constant amplitude, the self-healing objective is achieved by mounting, on the structural component of interest, a suitable microcontroller. Its input, from suitable sensors, covers the current stress and strain in the alloy. The microcontroller elaborates from the input the value of a decisional parameter and activates the thermal process when a threshold is overcome.

넓이관련 열린 문제에 관한 문제해결 과정 분석 (Investigation of the Problem Solving in Open-Problem Related to Area)

  • 김민경
    • 한국수학교육학회지시리즈A:수학교육
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    • 제43권3호
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    • pp.275-289
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    • 2004
  • The purpose of the study is to investigate how children and preservice teachers would make a progress in solving the open-problems related to area. In knowledge-based information age, information inquiry, information construction, and problem solving are required. At the level of elementary school mathematics, area is mainly focused on the shape of polygon such as square, rectangle. However, the shape which we need to figure out at some point would not be always polygon-shape. With this perspective, many open-problems are introduced to children as well as preservice teacher. Then their responses are analyzed in terms of their logical thinking and their understanding of area. In order to make students improve their critical thinking and problem solving ability in real situation, the use of open problems could be one of the valuable methods to apply.

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체형교정을 통한 비만치료에 대한 소고(小考) (A Study on Obesity Management by Body Shape Correction Program)

  • 임형호;송윤경
    • 한방비만학회지
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    • 제5권1호
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    • pp.133-140
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    • 2005
  • The prevalence of obesity at all ages in increasing epidemically worldwide. There were many study of an indirect method on fat mass measurement in obesity, but were few study to determine the possible relationships between local fat deposition and health-related fitness parameters in overweight and obesity. We has reviewed on the somatotype characteristics, ideal posture and biomechanics, and adipose tissue of connective tissue, myofacia continuity. We consider that these unique 'whole systems' view is of vital importance to understanding the role of adipose tissue in musculoskeletal system and to application of body shape correction program.

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고점도 유체 내에서 부양하는 거품의 종말속도, 항력계수, 형태 분석 (Analysis of Terminal Velocity, Drag Coefficient and Shape of Bubble Rising in High Viscous Fluid)

  • 김진현;김정현
    • Korean Chemical Engineering Research
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    • 제48권4호
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    • pp.462-469
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    • 2010
  • 기체와 액체가 만나는 2상 공정들은 화학공학, 생명화학공학, 환경공학, 식품공학 등에 두루 존재한다. 위와 같은 공정의 최적화를 위해서는 거품의 움직임과 형태에 대한 정확한 파악이 필요하다. 액체 내부에서 거품의 움직임은 액체의 밀도, 점도, 표면장력과 거품의 크기와 속도에 영향을 받는다. 본 논문에서는 고점도 실리콘 오일 내부에서의 거품의 움직임과 형태를 관찰하였다. 또한 국외 논문 및 저서에서 정립된 거품의 에너지 수지 식, 항력계수와 변형계수를 이용하여 거품의 종말속도, 항력계수, 변형계수, 형태를 예측해 보고 이를 실험결과와 비교해 보았다. 실험 결과 거품의 속도는 점도가 낮을 경우가 더 빨랐고, 거품의 항력계수는 점도가 클 때 더 컸다. 거품의 형태는 점도가 클 때 덜찌그러진(구형에 가까운) 형태였다. 실험결과와 국외 논문 및 저서에서 정립된 항력계수와 변형계수를 이용한 예측결과를 비교해 본 결과 Batchelor가 제시한 이론이 가장 정확한 예측을 하는 것으로 나타났다. Batchelor가 제시한 거품의 에너지 수지식, 항력계수와 변형계수를 사용하여 예측한 거품의 2차원 측면 형태는 실험에서 관찰된 거품의 2차원 측면 형태와 유사하였다.