• Title/Summary/Keyword: Elements Analysis

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서브모델링과 응력선형화를 이용한 압력용기의 안전성 평가

  • Choe, Jae-Hun;Kim, Jun-Yeong
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.234-238
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    • 2015
  • When we use a Finite Elements Method (FEM) to solve a linear static analysis problem, number of elements need to be sufficiently small for convergence of the solution. If we analysis a part, whose curvature is varying heavily, we face to determine how small the elements size is, because the calculated stress is increased as the elements are smaller. In this case, we need to analysis with mesh insensitive method, stress linearization. We can get a solution that is not varying with the elements size if the size is smaller than a certain level. In this paper, we evaluate a pressure vessel having geometrical discontinuities using stress linearization. First, we analysis the vessel with global model, including all part of the vessel, using large shell elements. Second, we analysis the local part of the vessel, which is the small part occurring maximum stress, using small continuum elements. Last, we evaluate the safety of the pressure vessel according to the ASME Sec. VIII Div 2.

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Characterization of Ty3-gypsy-like Elements in Hibiscus syriacus

  • Jeung, Ji-Ung;Cho, Sung Ki;Lee, Seung Jae;Shin, Jeong Sheop
    • Molecules and Cells
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    • v.19 no.3
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    • pp.318-327
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    • 2005
  • Southern blot analysis revealed a ubiquitous distribution and high copy number of Ty3-gypsy-like elements in the genome of Hibiscus syriacus. Comparative phylogenetic analysis of the large subunit of Rubisco and the integrase region of Ty3-gypsy elements in various plant species indicated that the retrotransposon-like sequences have different evolutionary histories and their own unique polymorphism in the H. syriacus population. Sequence-tagged site-restriction fragment length polymorphisms (STS-RFLP) analysis also indicated great variability in the numbers and sequences of Ty3-gypsy-like elements within H. syriacus varieties. Ty3-gypsy-like elements may still be active within H. syriacus, since Northern analysis of wounded leaves of H. syriacus variety Saehan with a probe for the integrase domain gave strong hybridization signals. The sequence heterogeneity and ubiquity of the Ty3-gypsy-like elements in H. syriacus genomes could provide reliable DNA markers for line identification as well for the analysis of genetic diversity in H. syriacus.

Analysis of Multi-Layered Structural Systems Using Nonlinear Finite Elements-Boundary Elements (반무한 다중 구조계의 비선형 유한요소 - 경계요소 해석)

  • 김문겸;장정범;이상도;황학주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.04a
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    • pp.58-64
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    • 1992
  • It is usual that underground structures are constructed within multi-layered medium. In this paper, an efficient numerical model ling of multi-layered structural systems is studied using coupled analysis of finite elements and boundary elements. The finite elements are applied to the area in which the material nonlinearity is dominated, and the boundary elements are applied to the far field area where the nonlinearity is relatively weak. In the boundary element model 1 ins of the multi-layered medium, fundamental solutions are restricted. Thus, methods which can utilize existing Kelvin and Melan solution are sought for the interior multi-layered domain problem and semi infinite domain problem. Interior domain problem which has piecewise homogeneous layers is analyzed using boundary elements with Kelvin solution; by discretizing each homogeneous subregion and applying compatibility and equilibrium conditions between interfaces. Semi-infinite domain problem is analyzed using boundary elements with Melan solution, by superposing unit stiffness matrices which are obtained for each layer by enemy method. Each methodology is verified by comparing its results which the results from the finite element analysis and it is concluded that coupled analysis using boundary elements and finite elements can be reasonable and efficient if the superposition technique is applied for the multi-layered semi-infinite domain problems.

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A Study on the Relationship between VMD Structural Elements of Apparel Stores and Related Variables (의류 점포의 VMD 구성 요소와 관련 변인 연구)

  • Kim, Sun-Hee
    • The Research Journal of the Costume Culture
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    • v.15 no.4
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    • pp.726-736
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    • 2007
  • The purpose of this study was to identify VMD structural elements of apparel stores, and related variables. The related variables are contained shopping orientation, store types, consumer satisfaction and the intention to purchase in apparel stores. The data was collected from a questionnaire conducted on 378 female adults and was analyzed by frequency analysis, factor analysis, cluster analysis, ANDVA, regression, Duncan test, and reliability analysis. The results were as follows: (1) VMD structural elements of apparel store consisted of four factors: coordination/fitness, fashionability, attractiveness, and functionality. Shopping orientation consisted of six factors: recreational, rational, fashion oriented, convenience oriented, price conscious, and brand conscious. Shopper types consisted of four groups: recreational type shopper, economic type shopper, high involved shopper, and convenience oriented shopper. (2) Significant differences were find out between those shopper types and VMD structural elements. Significant differences were find out between store types and VMD structural elements. (3) VMD structural elements(coordination/fitness, functionality, fashionability) were influenced consumer satisfaction and the intention to purchase.

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Causes of local collapse of a precast industrial roof after a fire

  • Bruno Dal Lago;Paride Tucci
    • Computers and Concrete
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    • v.31 no.5
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    • pp.371-384
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    • 2023
  • Precast roofing systems employing prestressed elements often serve as smart structural solutions for the construction of industrial buildings. The precast concrete elements usually employed are highly engineered, and often consist in thin-walled members, characterised by a complex behaviour in fire. The present study was carried out after a fire event damaged a precast industrial building made with prestressed beam and roof elements, and non-prestressed curved barrel vault elements interposed in between the spaced roof elements. As a consequence of the exposure to the fire, the main elements were found standing, although some locally damaged and distorted, and the local collapse of few curved barrel vault elements was observed in one edge row only. In order to understand and interpret the observed structural performance of the roof system under fire, a full fire safety engineering process was carried out according to the following steps: (a) realistic temperature-time curves acting on the structural elements were simulated through computational fluid dynamics, (b) temperature distribution within the concrete elements was obtained with non-linear thermal analysis in variable regime, (c) strength and deformation of the concrete elements were checked with non-linear thermal-mechanical analysis. The analysis of the results allowed to identify the causes of the local collapses occurred, attributable to the distortion caused by temperature to the elements causing loss of support in early fire stage rather than to the material strength reduction due to the progressive exposure of the elements to fire. Finally, practical hints are provided to avoid such a phenomenon to occur when designing similar structures.

Design Case Analysis of Hotel Room Based on Artistic Quotient - Focused on the Experience of Livability Using Refuge and Sense - (예술 지능에 기반한 호텔 객실의 디자인 사례 분석 - 은신처와 감각을 활용한 생명감 체험을 중심으로 -)

  • Kim, Nayeon;Lee, Hyunsoo
    • Korean Institute of Interior Design Journal
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    • v.26 no.6
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    • pp.116-125
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    • 2017
  • The study is aimed to analyze cases of hotel room designs based on the 'Art Quotient'. It is focused on design elements of livability, analyzing the space design in terms of biophilic design and experiential marketing. This paper proposes a direction for hotel design based on the analysis result. The scope of the study includes the cases of 17 hotels in the area of Seoul achieving five stars in Korea. This paper presents an analysis whether the room space of hotels provide a user-oriented life experience from the perspective of biophilic design and experiential marketing. In this study, we focused on the concept of 'refuge', one of the biophilic design elements that express the value of life sense, and the element of 'sense', one of the strategic experiential modules of experiential marketing. After analyzing the hotel case studies, the space was evaluated using five factors of art quotient as a design method to provide a life experience in the hotel room. Analysis of the design space from the viewpoint of refuge, rather than architectural elements, proved that decorative elements appeared most commonly in all hotel rooms. Further, through an analysis based on the measures of 'sense', an experiential element, visual elements were mostly enforced in among the elements of the five senses. In other words, when designing a hotel room space, visual elements such as color, pattern, furniture, lighting and style are mainly utilized. Examining the analysis of the design elements from the point of view of the art quotient, the rooms of all the hotel's suite types include elements of 'communication'. Most of the hotel rooms focused on stimulating the aesthetic sensibility of customers. This resulted in the elements of 'immersion' showing poor results. In conclusion, it is necessary to provide the five senses of the arts index in a balanced manner to provide a life experience through the five senses.

THE EFFECTS OF MESH STYLE ON THE FINITE ELEMENT ANALYSIS FOR ARTIFICIAL HIP JOINTS

  • Shin, Jae-Min;Lee, Dong-Sun;Kim, Sung-Ki;Jeong, Da-Rae;Lee, Hyun-Geun;Kim, Jun-Seok
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.15 no.1
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    • pp.57-65
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    • 2011
  • In this paper, a good quality mesh generation for the finite element method is investigated for artificial hip joint simulations. In general, bad meshes with a large aspect ratio or mixed elements can give rise to excessively long computational running times and extremely high errors. Typically, hexahedral elements outperform tetrahedral elements during three-dimensional contact analysis using the finite element method. Therefore, it is essential to mesh biologic structures with hexahedral elements. Four meshing schemes for the finite element analysis of an artificial hip joint are presented and compared: (1) tetrahedral elements, (2) wedge and hexahedral elements, (3) open cubic box hexahedral elements, and (4) proposed hexahedral elements. The proposed meshing scheme is to partition a part before seeding so that we have a high quality three-dimensional mesh which consists of only hexahedral elements. The von Mises stress distributions were obtained and analyzed. We also performed mesh refinement convergence tests for all four cases.

Development of super convergent Euler finite elements for the analysis of sandwich beams with soft core

  • Sudhakar, V;Gopalkrishnan, S;Vijayaraju, K
    • Structural Engineering and Mechanics
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    • v.65 no.6
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    • pp.657-678
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    • 2018
  • Sandwich structures are well known for their use in aircraft, naval and automobile industries due to their high strength resistance with light weight and high energy absorption capability. Sandwich beams with soft core are very common and simple structures that are employed in day to day general use appliances. Modeling and analysis of sandwich structures is not straight forward due to the interactions between core and face sheets. In this paper, formulation of Super Convergent finite elements for analysis of the sandwich beams with soft core based on Euler Bernoulli beam theory are presented. Two elements, Eul4d with 4 degrees of freedom assuming rigid core in transverse direction and Eul10d with 10 degrees of freedom assuming the flexible core were developed are presented. The formulation considers the top, bottom face sheets and core as separate entities and are coupled by beam kinematics. The performance of these elements are validated by results available in the published literature. Number of studies are performed using the formulated elements in static, free vibration and wave propagation analysis involving various boundary and loading conditions. The paper highlights the advantages of the elements developed over the traditional elements for modeling of sandwich beams and, in particular wave propagation analysis.

The Importance and Categorization of Task Elements of School Food Service Dietician (학교급식 영양사의 업무 중요도 및 임무차원 분석)

  • 이영은;양일선;차진아
    • Journal of Nutrition and Health
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    • v.35 no.6
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    • pp.668-680
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    • 2002
  • The purpose of this study was to investigation the importance and categorization of task elements of school food service dietician and to provide the useful data for standard model of the dietician′s tasks of school foodservice. This study was conducted in school food services nationwide in method of written questionnaire. The questionnaires were mailed to the dieticians of 3 type school foodservice system-conventional, commissary, joint management. Of the 660 schools that participated in this study, the responses from 212 conventional system and 212 commissary system and 200 joint management system were selected for analysis. Statistical analysis was performed with SAS/Win 6.12 package program for descriptive analysis, T-test, ANOVA, factor analysis using. The main results of this study can be summarized as follows Importance level was more than 4 score out of 5 scale in most of the task elements. The result was indicative of the appropriateness of definition of the 61 task elements. Of 61 task elements, importance level on ′nutrition education′ and on ′evaluation of foodservice operation management′ indicated the most significant difference between present and ideal situation. Through factor analysis, 61 task elements were regrouped into 7 dimensions; "Duty dimension of cooking and distribution management", "Duty dimension of cost management", "Duty dimension of raw material management", "Duty dimension of education management", "Duty dimension of menu management", "Duty dimension of record keeping of foodservice", "Duty dimension of general management (others)".

Insolation Modeling using Climate and Geo-Spatial Elements (기후요소와 지형 공간요소를 이용한 일사량 모델링)

  • Kim, Byung-Woo;Kang, In-Joon;Han, Ki-Bong
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.4
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    • pp.79-86
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    • 2010
  • This research is a thing about reverse operation about the solar power for location decision and increasing efficiency of the solar power generation equipments. The purpose of this research is reverse operation about the amount of sunshine using the climate and spatial elements. Following the result of correlation analysis, the wind-speed and cloud-amount factor are excluded, because the correlation and significance coefficients are out of value. Each outcome of regression analysis using the other four climate elements, and regression analysis using spatial elements is what the amount of sunshine and the solar altitude are the most influence to the insolation-modeling. Doing the regression analysis based on the precedent result make the result that climate elements have bigger coefficient of regression than spatial elements. This outcome means the climate elements are more influence than spatial elements.