• 제목/요약/키워드: cross-sectional analysis

검색결과 2,529건 처리시간 0.033초

복합재료 블레이드 단면 해석 프로그램(Ksec2d-AE)의 신뢰성 검증 (Validation Study of Composite Rotor Blade Sectional Analysis Program (Ksec2d-AE))

  • 배재성;김현식;배진규;임태현;황재민;정성남
    • 한국항공우주학회지
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    • 제46권4호
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    • pp.277-282
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    • 2018
  • 본 연구에서는 유한요소법 기반의 단면 특성치 해석 프로그램인 Ksec2d-AE의 정확성을 검증함으로써, 학부 수준의 비행체 구조해석 및 설계 시 활용가능성을 제시하고자 한다. 이를 위해 다양한 요소를 적용하여 Ksec2d-AE 로부터 계산된 단면강성계수 결과에 대한 유한요소의 수렴성을 확인하였다. 또한 Ksec2d-AE로부터 구한 단면강성계수를 상용 구조해석 프로그램인 MSC NASTRAN 으로부터 구한 강성계수와 비교하고, 주요 공학적 중심치(인장 중심, 전단 중심, 주 굽힘축)의 특성에 부합하게 구조물이 거동하는지 확인함으로써 Ksec2d-AE의 단면강성계수 및 중심치 결과를 검증하였다. 본 연구를 통하여 Ksec2d-AE 프로그램의 유용성을 확인하였다.

지자체장의 정치적 이념성향이 사회복지예산에 미치는 영향 - 경북 구미시의 사례로 본 종적 연구 (The Effect of Local Government Heads' Political Ideological Tendencies on Social Welfare Budget - A longitudinal study in the case of Gumi-si, Gyeongbuk)

  • 박중보;김귀곤
    • 산업융합연구
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    • 제20권5호
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    • pp.21-28
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    • 2022
  • 본 연구는 기존의 연구들과 달리 지자체장의 이념적 성향이 사회복지예산에 미치는 영향을 종적 연구로 살펴보았다. 이러한 연구는 지방자치제가 실시된 이후로 보수의 아성인 구미시에서 진보성향의 단체장이 당선됨으로써 가능하게 된 것이다. 따라서 본 연구에서는 경북 구미시의 12년 이상의 실제 사례를 가지고 구미시 지자체장의 정치적 이념성향의 변화과정과 연도별 사회복지예산을 나열하고 시계열분석을 실시하였다. 분석결과 첫째, 횡단면 분석과 마찬가지로 종단면 연구에서도 지자체장의 정치적 이념성향에 따른 사회복지예산의 증가율변화는 의미 있는 차이를 보였다. 둘째, 기존의 횡단면 분석결과와 같이 선거가 있기 전 해에 사회복지예산의 증가율이 높게 나타났다. 셋째, 두 번째와 같은 증가율의 변화는 한 사람의 3선이 종료되는 해에는 나타나지 않았다. 지금까지의 지자체장(지방의회 포함)의 정치적 이념성향과 사회복지예산의 관계에 관한 모든 연구들은 횡단면적으로 이루어져 왔다. 그러나 본 연구는 최초의 종단면 분석결과라는 측면에서 시사점이 매우 크다고 할 수 있다.

개더스커트 형상프로포션의 3차원적 해석 (Three-Dimensional Analysis of the Shapes of Gathered Skirts)

  • 이명희;정희경
    • 한국의류학회지
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    • 제30권11호
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    • pp.1598-1607
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    • 2006
  • The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.

부재력 특성을 고려한 변위조절설계법 개발 (Development of Drift Design Method Considering Characteristics of Member Forces)

  • 서지현;박효선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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    • pp.123-129
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    • 2003
  • Drift design using resizing techniques can be a very practical method in drift design of high-rise buildings since it cannot require sensitivity analysis and structural re-analysis. Resizing techniques has used the cross sectional areas as design variable and supposed that displacement participation factors are inversely proportional to structural weights. Efficiency of resizing techniques based on displacement participation factors may depend on proper selection of sectional properties as design variables. In this study, two different drift design methods with the different sectional properties as design variables are presented and applied to a 20-story structure.

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안면 비대칭 환자에서 Cone Beam Computed Tomography를 이용한 하악골 해부학적 변이의 분석 (Cone Beam Computed Tomography Analysis of Mandibular Anatomical Variation in a Patient with Facial Asymmetry)

  • 박성원;오승환;이재인
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제34권1호
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    • pp.34-40
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    • 2012
  • Purpose: The study was performed to compare patients with anatomical variations in facial asymmetry with patients in the normal range using cone-beam computed tomography (CBCT) and to take the preoperative condition into consideration in the case of a sagittal split ramus osteotomy (SSRO). Methods: The study was conducted on 46 adult patients composed of 2 subdivided groups, an asymmetry group (n=26) and a symmetry group (n=20). The asymmetry group was divided between patients with hemimandibular hyperplasia (HH, n=8) and hemimandibular elongation (HE, n=18). Using cross-sectional computed tomography images, the thickness of cancelleous bone in the buccal area of the mandible, thickness of buccal cortex in the buccal aspect of the mandible, thickness of cancellous bone in the inferior aspect of the mandible, thickness of buccal cortex in the inferior aspect of the mandible, and cross-sectional surface area of the mandible were measured. Results: In the asymmetry group, the cross-sectional area of the mandible including the inferior alveolar nerve positioned on the affected side was significantly different from the symmetry group. Thickness of cancelleous bone in the buccal aspect of the mandible, thickness of cancelleous bone in the inferior aspect of the mandible, and cross-sectional surface area of the mandible in the affected site of hemimandibular hyperplasia was significantly smaller than in the symmetry group. Conclusion: The inferior alveolar nerve runs lower and in a more buccal direction and shows a smaller cross-sectional surface of the mandible in the hemimandibular hyperplasia patients with asymmetry.

미국 수산물 수요에 있어서 가격과 질의 영향분석 (Price and qualify Effects in US Fisheries Demand)

  • 김기수
    • 수산경영론집
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    • 제26권1호
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    • pp.1-8
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    • 1995
  • This paper tries to estimate price and quality effects in US cross - sectional fisheries demand analysis using 1987-88 Nationwide Food Consumption Survey Data. The estimated results support to the hypothesis of quality effects in cross - sectional prices, which had been already proven by Cox and Wohlgenant(1986). But Since all zero observations for the respective incomes, expenditures and quantities are eliminated for the ease of computation, it may yield inconsistent estimates from selectivity bias.

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Effect of Three-dimensional Warping on Stiffness Constants of Closed Section Composite Beams

  • Dhadwal, Manoj Kumar;Jung, Sung Nam
    • International Journal of Aeronautical and Space Sciences
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    • 제18권3호
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    • pp.467-473
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    • 2017
  • This paper focuses on the investigation of three-dimensional (3D) warping effect on the stiffness constants of composite beams with closed section profiles. A finite element (FE) cross-sectional analysis is developed based on the Reissner's multifield variational principle. The 3D in-plane and out-of-plane warping displacements, and sectional stresses are approximated as linear functions of generalized sectional stress resultants at the global level and as FE shape functions at the local sectional level. The classical elastic couplings are taken into account which include transverse shear and Poisson deformation effects. A generalized Timoshenko level $6{\times}6$ stiffness matrix is computed for closed section composite beams with and without warping. The effect of neglecting the 3D warping on stiffness constants is shown to be significant indicating large errors as high as 93.3%.

패널자료의 무응답 대체법 (Non-Response Imputation for Panel Data)

  • 박기덕;신기일
    • Communications for Statistical Applications and Methods
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    • 제17권6호
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    • pp.899-907
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    • 2010
  • 무응답 대체(non-response imputation) 방법에 관한 많은 이론과 방법이 제안되었으며 실제 자료 분석에 이용되고 있다. 흔히 횡단면 무응답 대체를 위하여 다중대체법(multiple imputation)이 사용되고 있으며 2차년도 이상의 패널자료에는 종시점회귀대체법(cross-wave regression imputation)이 사용되고 있다. 본 연구에서는 패널자료 분석을 위하여 종시점회귀대체법의 일반형태인 시계열 대체법과 횡단면 무응답 대체법을 결합한 시계열-횡단면 다중 대체법을 제안하였다. 노동부의 매월노동통계 자료를 이용하여 제안한 방법과 기존의 종시점회귀대체법을 비교하여 우수함을 보였다.

비대칭(非對稱) 단면(斷面) 보강재(補剛材)의 강도해석(强度解析) (On the Strength Analysis of the Stiffener with Asymmetric Cross Section)

  • 임상전;양영순;이규성
    • 대한조선학회지
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    • 제17권1호
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    • pp.11-18
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    • 1980
  • In the conventional ship's structures, the stiffeners with asymmetric sections have been widely used, in spite of the disadvantage on the point of strength, compared to those with symmetric sections. So far, the stiffened plating was usually analyzed not considering the geometric unsymmetry characteristics of the section, including only the cross sectional area and moment of inertia. In this paper, the stiffened plating is devided into the strips having a thin-walled open cross section by using the concept of the effective width. The geometric characteristics of the sections are also included. The governing equations are derived, which can be applied to the arbitrary cross section beams, and the symmetric and the asymmetric section beams which have the same cross sectional areas are analyzed by using the finite element method. From that result, we obtain the allowable load of the two sections, and compared them.

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Three dimensional flow analysis within a profile extrusion die by using control volume finite-element method

  • Kim, Jongman;Youn, Jae-Ryoun;Hyun, Jae-Chun
    • Korea-Australia Rheology Journal
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    • 제13권2호
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    • pp.97-106
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    • 2001
  • Three-dimensional flow analysis was performed by using the control volume finite-element method for design of a profile extrusion die. Because polymer melt behavior is complicated and cross-sectional shape of the profile extrusion die is changing continuously, the fluid flow within the die must be analyzed three-dimensionally. A commercially available polypropylene is used for theoretical and experimental investigations. Material properties are assumed to be constant except for the viscosity. The 5-constant modified Cross model is used for the numerical analysis. A test problem is examined in order to verify the accuracy of the numerical method. Simulations are performed for conditions of three different screw speeds and three different die temperatures. Predicted pressure distribution is compared with the experimental measurements and the results of the previous two-dimensional study. The computational results obtained by using three dimensional CVFEM agree with the experimental measurements and are more accurate than those obtained by using the two-dimensional cross-sectional method. The velocity profiles and the temperature distributions within several cross-sections of the die are given as contour plots.

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