• 제목/요약/키워드: geometric theory

검색결과 570건 처리시간 0.028초

기하양식과 2차원적 각색 : 알로이스 리글(Alois Riegl)의 시지각이론과 비엔나 아르누보 건축 (Geometric Style and Two-Dimensional Transformation : Alois Riegl's Theory of Visual Perception and Vienna Art Nouveau Architecture)

  • 임석재
    • 건축역사연구
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    • 제3권2호
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    • pp.125-141
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    • 1994
  • Alois Riegl's aesthetic theory of visual perception provided one of important conceptual backgrounds for Vienna Art Nouveau architecture. Riegls theory of visual perception consists of geometric style and two-dimensional transformation. Riegl's theory of geometric style is based on the modern aesthetic theory of abstraction, which says that the artistic perfection can be obtained not from a direct imitation of natural objects, but from an abstract transformation of them. Riegl's theory of two-dimensional transformation, on the other hand, aims at obtaining artistic perfection by disintegrating volumetric conditions of natural things into planes and combining the planes thus obtained into another new world of art. These two theories of Alois Rigl's provided an important aesthetical background for the design strategy of 'abstract ornamentaion of two-dimension' in Vienna Art Nouveau architecture. This paper is to review the basic concept of Alois Rigl's theory of geometric style and two-dimensional transformation.

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Nonlinear resonances of nonlocal strain gradient nanoplates made of functionally graded materials considering geometric imperfection

  • Jia-Qin Xu;Gui-Lin She;Yin-Ping Li;Lei-Lei Gan
    • Steel and Composite Structures
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    • 제47권6호
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    • pp.795-811
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    • 2023
  • When studying the resonance problem of nanoplates, the existing papers do not consider the influences of geometric nonlinearity and initial geometric imperfection, so this paper is to fill this gap. In this paper, based on the nonlocal strain gradient theory (NSGT), the nonlinear resonances of functionally graded (FG) nanoplates with initial geometric imperfection under different boundary conditions are established. In order to consider the small size effect of plates, nonlocal parameters and strain gradient parameters are introduced to expand the assumptions of the first-order shear deformation theory. Subsequently, the equations of motion are derived using the Euler-Lagrange principle and solved with the help of perturbation method. In addition, the effects of initial geometrical imperfection, functionally graded index, strain gradient parameter, nonlocal parameter and porosity on the nonlinear forced vibration behavior of nanoplates under different boundary conditions are discussed.

Developing Geometry Software for Exploration-Geometry Player

  • Yuan, Yuan;Lee, Chun-Yi;Huang, Jiung-Rong
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제11권3호
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    • pp.209-218
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    • 2007
  • The purpose of this study is to create an interactive tool Geometry Player for geometric explorations. In designing this software, we referred to van Hiele's geometric learning theory of and Duval's cognitive comprehension theory of geometric figures. With Geometry Player, it is easy to construct and manipulate dynamic geometric figures. Teachers can easily present the dynamic process of geometric figures in class, and students can use it as a leaning tool to construct geometric concepts by themselves. It is hoped that Geometry Player can be a useful assistant for teachers and a nice partner for students. A brief introduction to Geometry Player and some application examples are included in this paper.

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한국 전통복식과 기하추상 예술의 정신적 유사성 (Mental similarities between the traditional Korean costume and geometric abstraction art)

  • 김혜영;권미정
    • 복식문화연구
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    • 제32권4호
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    • pp.577-596
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    • 2024
  • Geometric abstract art has been a persistent form since ancient times and is defined in modernity as a genre of abstract painting. According to previous studies, the geo- metric structure of traditional Korean costume possesses uniqueness based on Korean thought and philosophy. Therefore, the purpose of this study is to first derive the characteristics of Wilhelm Worringer's theory, a theorist of geometric abstraction, and then compare the spiritual similarities between the traditional Korean costume and geometric abstract art, with the aim of examining the artistic competitiveness of Hanbok. Photographic materials from domestic and international museums, as well as books published by museums and government agencies, were analyzed. Further, the characteristics of Worringer's theory of the abstract impulse were derived. The results are as follows. First, the external factors are characterized by a single geometric shape on a flat surface with restrained spatial expression. The internal factors include anxiety, comfort from religion or ideology, and the need for a visual refuge for rest. Second, traditional Korean costume and geometric abstraction share common spiritual contexts of artistry, transcendence, and stability according to Worringer's theory. Third, the study of the spiritual similarities between the traditional Korean costume and geometric abstract art through Worringer's theory reveals that the artistry of traditional Korean costume is expressed in universal forms, transcendence as intrinsic origins, and stability as a unique aesthetic consciousness. These findings provide a framework for reinterpreting the originality and universality of traditional Korean costume as Korean cultural content, infused with the characteristics of modern art.

Nonlinear low-velocity impact of graphene platelet-reinforced metal foam beam with geometrical imperfection

  • Yi-Han Cheng;Gui-Lin She
    • Steel and Composite Structures
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    • 제52권6호
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    • pp.609-620
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    • 2024
  • The impact problem of imperfect beams is crucial in engineering fields such as water conservancy and transportation. In this paper, the low velocity impact of graphene reinforced metal foam beams with geometric defects is studied for the first time. Firstly, an improved Hertz contact theory is adopted to construct an accurate model of the contact force during the impact process, while establishing the initial conditions of the system. Subsequently, the classical theory was used to model the defective beam, and the motion equation was derived using Hamilton's principle. Then, the Galerkin method is applied to discretize the equation, and the Runge Kutta method is used for numerical analysis to obtain the dynamic response curve. Finally, convergence validation and comparison with existing literature are conducted. In addition, a detailed analysis was conducted on the sensitivity of various parameters, including graphene sheet (GPL) distribution pattern and mass fraction, porosity distribution type and coefficient, geometric dimensions of the beam, damping, prestress, and initial geometric defects of the beam. The results revealed a strong inhibitory effect of initial geometric defects on the impact response of beams.

Metric and Spectral Geometric Means on Symmetric Cones

  • Lee, Hosoo;Lim, Yongdo
    • Kyungpook Mathematical Journal
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    • 제47권1호
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    • pp.133-150
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    • 2007
  • In a development of efficient primal-dual interior-points algorithms for self-scaled convex programming problems, one of the important properties of such cones is the existence and uniqueness of "scaling points". In this paper through the identification of scaling points with the notion of "(metric) geometric means" on symmetric cones, we extend several well-known matrix inequalities (the classical L$\ddot{o}$wner-Heinz inequality, Ando inequality, Jensen inequality, Furuta inequality) to symmetric cones. We also develop a theory of spectral geometric means on symmetric cones which has recently appeared in matrix theory and in the linear monotone complementarity problem for domains associated to symmetric cones. We derive Nesterov-Todd inequality using the spectral property of spectral geometric means on symmetric cones.

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Mobile robot indoor map making using fuzzy numbers and graph theory

  • Kim, Wan-Joo;Ko, Joong-Hyup;Chung, Myung-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.491-495
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    • 1993
  • In this paper, we present a methodology to model an indoor environment of a mobile robot using fuzzy numbers and to make a global map of the robot environment using graph theory. We describe any geometric primitive of robot environment as a parameter vector in parameter space and represent the ill-known values of the prameterized geometric primitive by means of fuzzy numbers restricted to appropriate membership functions. Also we describe the spatial relations between geometric prinitives using graph theory for local maps. For making the global map of the mobile robot environment, the correspondence problem between local maps is solved using a fuzzy similarity measure and a Bipartite graph matching technique.

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지리산(智異山) 화엄사가람(華嚴寺伽藍)의 조영사상(造營思想)에 관(關)한 연구(硏究) -풍수사상을 중심(中心)으로- (A study on the Organizing Principle of Hwaeomsa Temple in Chiri Mountain - Focused on the Theory of Feng-Shui(Configuration of the Ground) -)

  • 이동영;최효승
    • 한국농촌건축학회논문집
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    • 제2권3호
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    • pp.77-84
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    • 2000
  • Kurye-gun, which Hwaeomsa temple is located, has huge scale's geographical characteristics, such as mountains, rivers and open fields. This is really blessing area because of Som-jin river at the bottom of Ghiri mountain and open fields, which this situation is very difficult. The location of Hwaeomsa temple is an end of The Baek-Doo Mountains and very important spot(where influences to its geometric converge) of the theory of feng-shui. On exposure logic of the Korean traditional theory of feng-shui, the organization in Ga-Ram of Hwaeomsa temple is inconsistent with representative theory and analyzing system. So, this is one of successful examples with the theory of feng-shui because exhalation from the earth and water was organized well with accuracy.

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Analyzing nonlinear mechanical-thermal buckling of imperfect micro-scale beam made of graded graphene reinforced composites

  • Khalaf, Basima Salman;Fenjan, Raad M.;Faleh, Nadhim M.
    • Advances in materials Research
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    • 제8권3호
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    • pp.219-235
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    • 2019
  • This research is devoted to analyzing mechanical-thermal post-buckling behavior of a micro-size beam reinforced with graphene platelets (GPLs) based on geometric imperfection effects. Graphene platelets have three types of dispersion within the structure including uniform-type, linear-type and nonlinear-type. The micro-size beam is considered to be perfect (ideal) or imperfect. Buckling mode shape of the micro-size beam has been assumed as geometric imperfection. Modified couple stress theory has been used for describing scale-dependent character of the beam having micro dimension. Via an analytical procedure, post-buckling path of the micro-size beam has been derived. It will be demonstrated that nonlinear buckling characteristics of the micro-size beam are dependent on geometric imperfection amplitude, thermal loading, graphene distribution and couple stress effects.

A theoretical mapping model for bridge deformation and rail geometric irregularity considering interlayer nonlinear stiffness

  • Leixin, Nie;Lizhong, Jiang;Yulin, Feng;Wangbao, Zhou;Xiang, Xiao
    • Steel and Composite Structures
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    • 제46권1호
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    • pp.93-105
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    • 2023
  • This paper examines a high-speed railway CRTS-II ballastless track-bridge system. Using the stationary potential energy theory, the mapping analytical solution between the bridge deformation and the rail vertical geometric irregularity was derived. A theoretical model (TM) considering the nonlinear stiffness of interlayer components was also proposed. By comparing with finite element model results and the measured field data, the accuracy of the TM was verified. Based on the TM, the effect of bridge deformation amplitude, girder end cantilever length, and interlayer nonlinear stiffness (fastener, cement asphalt mortar layer (CA mortar layer), extruded sheet, etc.) on the rail vertical geometric irregularity were analyzed. Results show that the rail vertical deformation extremum increases with increasing bridge deformation amplitude. The girder end cantilever length has a certain influence on the rail vertical geometric irregularity. The fastener and CA mortar layer have basically the same influence on the rail deformation amplitude. The extruded sheet and shear groove influence the rail geometric irregularity significantly, and the influence is basically the same. The influence of the shear rebar and lateral block on the rail vertical geometric irregularity could be negligible.