• Title/Summary/Keyword: shape functions

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Representation of the Body in Fashion (II) - Focusing on the Representation of Physicality - (복식에 표현된 몸의 재현성 [II] - 몸의 사실성 변질을 중심으로 -)

  • Yim, Eun-Hyuk
    • Journal of the Korean Society of Costume
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    • v.56 no.9 s.109
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    • pp.66-82
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    • 2006
  • Clothes and human body are inseparably related. Aesthetic consciousness of the body determines the form of clothing, reflecting the time and culture as well as the individual and society. Clothes can even reorganize the meaning of the body, while transcending their instrumental functions of protecting, expanding and deforming the body. Using 'body' to analyze the clothing form, my study develops a framework by which to classify the representation of the body in fashion focusing on the representation of physicality. In order to inquire the formative style and aesthetic values expressed in representing body in fashion, my study examines subjects from the 14th century European costumes to fashion collections of the 20th century. In fashion, representation of the body is visually analogous to the ideal boily shape and structure, including a realistic presentation of the body as well as reflection of aesthetic ideals. Manipulation of physicality entails the reconstruction of the ideal body image through the clothes that modify physicality into unnatural body. Ruff collar, gigot sleeve, crinoline, bustle, stomacher, and corset were all used to materialize the fictitious curves symbolizing femininity, authority, healthiness, maternity, virginity, socioeconomic status, and fertility. Accentuating specific clothing parts represents emphasizing the symbolism of the correspondent body parts. Consequently, in this phase signifiant is $signifi\'{e}$. Aesthetic ideal of the body is visualized in the firm of a dress. Fashion continues to explore forms and images that transcend the traditional representations of the clothed body. As a type of intimate architecture, fashion always mediates the dialogue between clothes and body, or fashion and figure. My study suggests a framework to analyze bodily representation in fashion, focusing on the relationship between the clothes and body.

Free vibration analysis of combined system with variable cross section in tall buildings

  • Jahanshahia, Mohammad Reza;Rahgozar, Reza
    • Structural Engineering and Mechanics
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    • v.42 no.5
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    • pp.715-728
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    • 2012
  • This paper deals with determining the fundamental frequency of tall buildings that consist of framed tube, shear core, belt truss and outrigger systems in which the framed tube and shear core vary in size along the height of the structure. The effect of belt truss and outrigger system is modeled as a concentrated rotational linear spring at the belt truss and outrigger system location. Many cantilevered tall structures can be treated as cantilevered beams with variable cross-section in free vibration analysis. In this paper, the continuous approach, in which a tall building is replaced by an idealized cantilever continuum representing the structural characteristics, is employed and by using energy method and Hamilton's variational principle, the governing equation for free vibration of tall building with variable distributed mass and stiffness is obtained. The general solution of governing equation is obtained by making appropriate selection for mass and stiffness distribution functions. By applying the separation of variables method for time and space, the governing partial differential equation of motion is reduced to an ordinary differential equation with variable coefficients with the assumption that the transverse displacement is harmonic. A power-series solution representing the mode shape function of tall building is used. Applying boundary conditions yields the boundary value problem; the frequency equation is established and solved through a numerical process to determine the natural frequencies. Computer program has been developed in Matlab (R2009b, Version 7.9.0.529, Mathworks Inc., California, USA). A numerical example has been solved to demonstrate the reliability of this method. The results of the proposed mathematical model give a good understanding of the structure's dynamic characteristics; it is easy to use, yet reasonably accurate and suitable for quick evaluations during the preliminary design stages.

General Theory for Free Vibration and Stability Analysis of Thin-walled Space Frames (박벽 공간뼈대구조의 자유진동 및 안정성해석을 위한 일반이론)

  • 김문영;김성보
    • Computational Structural Engineering
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    • v.11 no.1
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    • pp.191-204
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    • 1998
  • The general formulation for free vibration and stability analysis of unsymmetric thin-wared space frames is presented in case where the shear deformation effects are neglected. The kinetic and total potential energies are derived by applying the extended virtual work principle, introducing displacement parameters defined at the arbitrarily chosen axis and including warping deformation and second order terms of finite semitangential rotations. In formulating the finite element procedure, cubic Hermitian polynomials are utilized as shape functions of the two node space frame element. Mass, elastic stiffness, and geometric stiffness matrices for the unsymmetric thin-walled section are evaluated, and load-correction stiffness matrices for off-axis distributed loadings are considered. In order to illustrate the accuracy and practical usefulness of this formulation, finite element solutions for the free vibration and stability problems of thin-walled beam-columns and space frames are presented and compared with available solutions.

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A Comparison Study of Wing Leading Edge Skin Models in Small Composite Solar-Powered UAVs (소형 복합재 태양광 무인기 윙 리딩에지스킨 모델 비교 연구)

  • Yang, Yong-Man;Kim, Yong-Ha;Kim, Jong-Hwan;Kim, Young-In;Lee, Soo-Yong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.5
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    • pp.445-452
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    • 2017
  • The wing leading edge skin in this research is an essential structural factor for improving wings' aeromechanical functions, protecting the interior elements of the wings from external damage including birds, and navigating planes safely. The study compared and reviewed models manufactured for optimal light-weight wings of composite UAVs. It compared and investigated displacement forms of torsion loads through finite element analysis using MSC. Patran/Nastran. By confirming the improvement of light-weighting performance according to lamination type, thickness change and shape through torsion strength tests of each model, the research suggested the optimal light-weight wing leading edge skin for small composite UAVs.

Lateral-Torsional Post-Buckling Analyses of Thin-Walled Space Frames with Non-symmetric Sections (비대칭단면을 갖는 박벽 공간뼈대구조의 횡-비틂 후좌굴 유한요소해석)

  • Park, Hyo Gi;Kim, Sung Bo;Kim, Moon Young;Chang, Sung Pil
    • Journal of Korean Society of Steel Construction
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    • v.11 no.2 s.39
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    • pp.153-165
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    • 1999
  • In order to trace the lateral-torsional post-bucking behaviors of thin-walled space frames with non-symmetric cross sections, a geometrically non-linear finite element formulation is presented by applying incremental equilibrium equations based on the updated Lagrangian formulation and introducing Vlasov's assumption. The improved displacement field for non-symmetric thin-walled cross sections is introduced based on inclusion of second order terms of finite rotations, and the potential energy corresponding to the semitangential rotations and moments is consistently derived. For finite element analysis, tangent stiffness matrices of thin-walled space frame element are derived by using the Hermition polynomials as shape functions. A co-rotational formulation in order to evaluate the unbalanced loads is presented by separating the rigid body rotations and pure deformations from incremental displacements and evaluating the updated direction cosines and incremental member forces.

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Development of Digital Leaf Authoring Tool for Virtual Landscape Production (가상 조경 생성을위한 디지털 잎 저작도구 개발)

  • Kim, Jinmo
    • Journal of the Korea Computer Graphics Society
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    • v.21 no.5
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    • pp.1-10
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    • 2015
  • This study proposes a method of developing authoring tool that can easily and intuitively generate diverse digital leaves that compose virtual landscape. The main system of the proposed authoring tool consists of deformation method for the contour of leaf blade based on image warping, procedural modeling of leaf vein and visualization method based on mathematical model that expresses the color and brightness of leaves. First, the proposed authoring tool receives leaf input image and searches for contour information on the leaf blades. It then designs leaf blade deformation method that can generate diverse shapes of leaf blades in an intuitive structure using feature-based image warping. Based on the computed leaf blade contour, the system implements the generalized procedural modeling method suitable for the authoring tool that generates natural vein patterns appropriate for the leaf blade shape. Finally, the system applies visualization function that can express color and brightness of leaves and their changes over time using a mathematical model based on convolution sums of divisor functions. This paper provides texture support function so that the digital leaves that were generated using the proposed authoring tool can be used in a variety of three-dimensional digital contents field.

Open reduction of mandibular fracture without maxillomandibular fixation: retrospective study (악간고정 없는 하악골 골절의 관혈적 정복술: 후향적 연구)

  • Lee, Chung-Hyun;Kim, Chul-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.37 no.4
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    • pp.255-263
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    • 2011
  • Introduction: Maxillomandibular fixation (MMF) is essential before surgery under general anesthesia in maxillofacial trauma patients. MMF is used basically to reconstruct the occlusion and occlusal stability to recover the facial shape and oral functions. The arch bar and wire is a traditional method for MMF, but it can not only bring pressure to the periodontal ligaments and teeth but also cause a penetrating injury to the surgeons. Materials and Methods: In this study, 198 patients with an open reduction using a manual reduction without MMF from September 2005 to May 2010 in Dankook University Dental Hospital were subjected to a follow-up evaluation during the postoperative 4 months periods. This study evaluated the incidence of complications according to the condition of the patient (gender, age), the state of bony union of the fracture sites and a numeric rating scale evaluation for postoperative pain scoring. Results: 1. The complications were classified into major and minor according to the seriousness, and the major complication rate was as low as 2.02%. Only 2 cases of re-operations (1.01%) were encountered. In the classification according to the fracture line, plate fracture was observed in both cases of mandibular symphysis fracture, and angle fractures and loosening of two screws were noted in the case of mandibular angle fracture. 2. The complication rate was similar regardless of gender and age. 3. The degree of bony union was satisfactory, and the complication rate was reduced as the bony union improved. 4. More patients complained of pain as the operation time was increased. Conclusion: The use of MMF is not always necessary if a skilled assistant is provided to help manually reduce the fracture site. Compared to other studies of mandibular fracture surgery using MMF, the complication rate was similar using only manual reduction and the patients' discomfort was reduced without MMF.

Stability and Post-Buckling Analyses of Thin-Walled Space Frames Using Finite Element Method (박벽 공간뼈대구조의 안정성 및 후좌굴 유한요소해석)

  • 김문영;안성원
    • Computational Structural Engineering
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    • v.10 no.4
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    • pp.205-216
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    • 1997
  • In order to trace the lateral post-buckling behaviors of thin-wafled space frames, a geometrically nonlinear finite element formulation is presented by applying incremental equilibrium equations based on the updated Lagrangian formulation and introducing Vlasov's assumption. The improved displacement field for symmetric thin-walled cross sections is introduced based on inclusion of second order terms of finite rotations, and the potential energy corresponding to the semitangential rotations and moments is consistently derived. For finite element analysis, tangent stiffness matrices of the thinwalled space frame element with 7 degrees of freedom including the restrained warping for each node are derived by using the Hermition polynomials as shape functions. A co-rotational formulation in order to evaluate the unbalanced loads is presented by separating the rigid body rotations and pure deformations from incremental displacements and evaluating the updated direction cosines of the frame element due to rigid body rotations and incremental member forces from pure deformations. Finite element solutions for the spatial buckling and post-buckling analysis of thin-walled space frames are presented and compared with available solutions and other researcher's results.

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Geometrically Non-linear Finite Element Analysis of Space Frames (공간뼈대구조의 기하학적 비선형 유한요소해석)

  • 김문영;안성원
    • Computational Structural Engineering
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    • v.10 no.1
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    • pp.201-211
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    • 1997
  • A clearly consistent finite element formulation for geometrically non-linear analysis of space frames is presented by applying incremental equilibrium equations based on the updated Lagrangian formulation and introducing Vlasov's assumption. The improved displacement field for symmetric cross sections is introduced based on inclusion of second order terms of finite rotations, and the potential energy corresponding to the semitangential rotations and moments is consistently derived. For finite element analysis, elastic and geometric stiffness matrices of the space frame element are derived by using the Hermitian polynomials as shape functions. A co-rotational formulation in order to evaluate the unbalanced loads is presented by separating the rigid body rotations and pure deformations from incremental displacements and evaluating the updated direction cosines of the frame element due to rigid body rotations and incremental member forces from pure deformaions. Finite element solutions for the spatial buckling and post-buckling analysis of space frames are compared with available solutions and other researcher's results.

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Optimal Design of the Steel Wheel's Disc Hole Using Approximation Function (근사함수를 이용한 스틸휠의 디스크 홀의 최적화)

  • 임오강;유완석;김우현;조재승
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.1
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    • pp.105-111
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    • 2003
  • Wheel for passenger car support the car weight with tires, and they transmit rolling and braking power into the ground. Whittling away at wheel weight is more effective to boost fuel economy than lighting vehicle body structure. A shape of hole in disk is optimized for minimizing the weight of steel wheel. Pro/ENGINEER program is used for formulating the design model, and ANSYS package is selected for analyzing the design model. It has difficulties to interface these commercial software directly. For Combining both programs, response surface methodology is applied to construct approximation functions for maximum stresses and maximum displacements are obtained by full factorial design of five levels. This steel wheel is modeled in 14-inch diameter of rim, and wide parameter of hole in disk is only selected as design variable for reducing the weight of steel whee. PLBA(Pshenichny-Lim-Belegundu-Arora) algorithm, which used the second-order information in the direction finding problem and uses the active set strategy, is used for solving optimization problems.