• Title/Summary/Keyword: Virtual mass method

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Multiscale Wavelet-Galerkin Method in General Two-Dimensional Problems (일반 형상의 2차원 영역에서의 멀티스케일 웨이블렛-갤러킨 기법)

  • Kim, Yun-Yeong;Jang, Gang-Won;Kim, Jae-Eun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.5
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    • pp.939-951
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    • 2002
  • We propose a new multiscale Galerkin method based on interpolation wavelets for two-dimensional Poisson's and plane elasticity problems. The major contributions of the present work are: 1) full multiresolution numerical analysis is carried out, 2) general boundaries are handled by a fictitious domain method without using a penalty term or the Lagrange multiplier, 3) no special integration rule is necessary unlike in the (bi-)orthogonal wavelet-based methods, and 4) an efficient adaptive scheme is easy to incorporate. Several benchmark-type problems are considered to show the effectiveness and the potentials of the present approach. is 1-2m/s and impact deformation of the electrode depends on the strain rate at that velocity, the dynamic behavior of the sinter-forged Cu-Cr is a key to investigate the impact characteristics of the electrodes. The dynamic response of the material at the high strain rate is obtained from the split Hopkinson pressure bar test using disc-type specimens. Experimental results from both quasi-static and dynamic compressive tests are Interpolated to construct the Johnson-Cook model as the constitutive relation that should be applied to simulation of the dynamic behavior of the electrodes. The impact characteristics of a vacuum interrupter are investigated with computer simulations by changing the value of five parameters such as the initial velocity of a movable electrode, the added mass of a movable electrode, the wipe spring constant, initial offset of a wipe spring and the virtual fixed spring constant.

A Study on the Strategy for Internet Electronic Commerce of Fashion Industry (패션산업(産業)의 인터넷 전자상거래(電子商去來) 활용방안(活用方案)에 관(關)한 연구(硏究))

  • Chung, Hye-Joo;Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • v.3 no.1
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    • pp.81-92
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    • 1999
  • The purpose of this thesis is to analyze the present conditions and problems of the Electronic Commerce, specially by the fashion companies that utilize the Internet and to propose using plans of Internet Electronic Commerce as a strategic method of fashion companies that have a information-oriented mind to adapt itself to modern century. On the basis of my analysis, I propose some using plans of Internet Electronic Commerce by the fashion companies as follows. As a means of construction method, it is need for the pertinent companies to have an information-oriented mind and then to construct the low-expense but high-speed communication Infrastructure. As an operation and management method, positive web site advertisements plans, such as promotion, using various mass media, subscribing to the Internet search engines and dissemination of products information, etc., are need for companies to attract the consumers to connect to the web site. Second, to offer more satisfactory experiences, it is need for companies to frame the integrated shopping mall as a strategic alliance in the management of shopping mall. To frame the integrated shopping mall is also effective in solving financial problems of shopping mall management and introducing of security system As a means of technology supplement, security management systems, such as SSL or SET, should be introduced for consumers to pay the price and furnish their personal informations. Second, new technology developments, such as the newest simulation programs using Virtual Reality to solve the problem of products' actual feeling, should be need for consumers to feel as they really put clothes on. If these technological developments are realized, fashionable products will be dealt in the Internet shopping mall as well and the marketability of Internet shopping mall will be expanded.

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Fingertip Extraction and Hand Motion Recognition Method for Augmented Reality Applications (증강현실 응용을 위한 손 끝점 추출과 손 동작 인식 기법)

  • Lee, Jeong-Jin;Kim, Jong-Ho;Kim, Tae-Young
    • Journal of Korea Multimedia Society
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    • v.13 no.2
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    • pp.316-323
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    • 2010
  • In this paper, we propose fingertip extraction and hand motion recognition method for augmented reality applications. First, an input image is transformed into HSV color space from RGB color space. A hand area is segmented using double thresholding of H, S value, region growing, and connected component analysis. Next, the end points of the index finger and thumb are extracted using morphology operation and subtraction for a virtual keyboard and mouse interface. Finally, the angle between the end points of the index finger and thumb with respect to the center of mass point of the palm is calculated to detect the touch between the index finger and thumb for implementing the click of a mouse button. Experimental results on various input images showed that our method segments the hand, fingertips, and recognizes the movements of the hand fast and accurately. Proposed methods can be used the input interface for augmented reality applications.

Development of Simplified Immersed Boundary Method for Analysis of Movable Structures (가동물체형 구조물 해석을 위한 Simplified Immersed Boundary법의 개발)

  • Lee, Kwang-Ho;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.3
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    • pp.93-100
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    • 2021
  • Since the IB (Immersed Boundary) method, which can perform coupling analysis with objects and fluids having an impermeable boundary of arbitrary shape on a fixed grid system, has been developed, the IB method in various CFD models is increasing. The representative IB methods are the directing-forcing method and the ghost cell method. The directing-forcing type method numerically satisfies the boundary condition from the fluid force calculated at the boundary surface of the structure, and the ghost-cell type method is a computational method that satisfies the boundary condition through interpolation by placing a virtual cell inside the obstacle. These IB methods have a disadvantage in that the computational algorithm is complex. In this study, the simplified immersed boundary (SIB) method enables the analysis of temporary structures on a fixed grid system and is easy to expand to three proposed dimensions. The SIB method proposed in this study is based on a one-field model for immiscible two-phase fluid that assumes that the density function of each phase moves with the center of local mass. In addition, the volume-weighted average method using the density function of the solid was applied to handle moving solid structures, and the CIP method was applied to the advection calculation to prevent numerical diffusion. To examine the analysis performance of the proposed SIB method, a numerical simulation was performed on an object falling to the free water surface. The numerical analysis result reproduced the object falling to the free water surface well.

A Study on the Dynamic Post-Buckling Behavior of the Plane Frame Structures Subjected to Circulatory Forces (Circulatory Force를 받는 평면(平面)뼈대 구조물(構造物)의 동적(動的) 후좌굴(後座屈) 거동(擧動)에 관한 연구(硏究))

  • Kim, Moon Young;Chang, Sung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.2
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    • pp.13-24
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    • 1988
  • A geometrically nonlinear analysis procedure for plane frame structures in order to study the static and dynamic post-buckling behavior of these structures subjected to circulatory forces is presented. The elastic and geometric stiffness matrices, the mass matrix and load correction stiffness matrix are derived from the extended virtual work principle, where the tangent stiffness matrix becomes non-symmetric due to the effects of non-conservative circulatory forces. The dynamic analysis of plane frame structures subjected to circulatory forces in pre- and post-buckling ranges is carried out by integrating the equations of motion directly by the numerically stable Newmark method. Numerical results are presented in order to demonstrate the vality and accuracy of the proposed procedure.

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Implementation of Markerless Augmented Reality with Deformable Object Simulation (변형물체 시뮬레이션을 활용한 비 마커기반 증강현실 시스템 구현)

  • Sung, Nak-Jun;Choi, Yoo-Joo;Hong, Min
    • Journal of Internet Computing and Services
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    • v.17 no.4
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    • pp.35-42
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    • 2016
  • Recently many researches have been focused on the use of the markerless augmented reality system using face, foot, and hand of user's body to alleviate many disadvantages of the marker based augmented reality system. In addition, most existing augmented reality systems have been utilized rigid objects since they just desire to insert and to basic interaction with virtual object in the augmented reality system. In this paper, unlike restricted marker based augmented reality system with rigid objects that is based in display, we designed and implemented the markerless augmented reality system using deformable objects to apply various fields for interactive situations with a user. Generally, deformable objects can be implemented with mass-spring modeling and the finite element modeling. Mass-spring model can provide a real time simulation and finite element model can achieve more accurate simulation result in physical and mathematical view. In this paper, the proposed markerless augmented reality system utilize the mass-spring model using tetraheadron structure to provide real-time simulation result. To provide plausible simulated interaction result with deformable objects, the proposed method detects and tracks users hand with Kinect SDK and calculates the external force which is applied to the object on hand based on the position change of hand. Based on these force, 4th order Runge-Kutta Integration is applied to compute the next position of the deformable object. In addition, to prevent the generation of excessive external force by hand movement that can provide the natural behavior of deformable object, we set up the threshold value and applied this value when the hand movement is over this threshold. Each experimental test has been repeated 5 times and we analyzed the experimental result based on the computational cost of simulation. We believe that the proposed markerless augmented reality system with deformable objects can overcome the weakness of traditional marker based augmented reality system with rigid object that are not suitable to apply to other various fields including healthcare and education area.

A study on 3D Modeling Process & Rendering Image of CAD Program-With Case study on Cellular Phone Design- (캐드에 의한 3차원 모델링 제작과정과 렌더링 이미지 연출에 관한 연구-무선 이동 전화기 디자인 사례를 중심으로-)

  • 이대우
    • Archives of design research
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    • no.18
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    • pp.25-34
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    • 1996
  • Industrial design development methods and processes have changed in accordance with Industrial Information Age. These days, problems are created by existing methods and evaluation of design value , all problems concerned with time and finances sitaution have been made a subject of discussion. Development of design processes have been changed by the development of problem recognition and solving tools, and dpsign tpchnulugy havp hppn replaced by computer technology,Thus. software design processes linking thoughtware to hardware are used in the solution of design problems with many parts. In this study, 3D Modeling samples are presented, 3D Modeling can realise ' Ideas' to '3Dimentional Virtual Ohjects'. These effect and value are anle to decisively influence the process of design problem conference-ebealuation-solution.Proxesses of actual modeling and rendering are made as follows. By compusition of simple 20 drawings and shaping them into 30 objects, 30 solid models can be made. To prssent effectivley, we can make a sample model by varying camera views,light sourses,materials and colours etc. This sample is evaluated by various cumposition, methods and PERT(Program Evaluation and Review Technique). This cuncrete sample (tentative plan)is changed within the CAD SYSTEM by design evaluation, and then converted to flowchart of mass productive conception through refined data. So, that tentative plan can be conformed to design desire actuillly, to the utmost degree. Finally, this design process can be proposed as il new method in cuntrast with current methods. The aim of this study is to suggest effective evaluation methods of design outcome among many evaluating elements.

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Space Design Expression Method According to the Analysis of the Characteristics of Movies - Focused on the Characteristics Expressive of the Illusionist - (영화의 특성 분석에 따른 공간디자인의 표현방법 - 환영성 표현 특성을 중심으로 -)

  • 송춘의
    • Archives of design research
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    • v.17 no.1
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    • pp.231-240
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    • 2004
  • Space design in the 21st century has been developed in connection with media more various than ever. In the age of image represented by popular culture, space design connected with media is based on post-reason thoughts constituting the post-modern society, and reflects polysemously and pluralistically changes in the society through the identification of art with life. The movie, which is an image perceived particularly sensibly and the most impractical simulated image among various illusionary media images composing the contemporary society, is growing rapidly in interrelation with various fields of art based on its peculiar nature, and its influence is getting more extensive. The movie manipulates mass society to create what does not exist and restore lost images into new realities through the reproduction of extremely realistic senses, and uses them in establishing virtual realities and creating illusionary images representing the age of simularc. The illusionary expression of the movie produces new meanings through disintegrating existing meanings and recombining them, and expresses popular culture from a position closest to our everyday life. Such an analytical attitude toward the illusionary movie reflecting our society can be a new approach to space design. The present study attempts to suggest the possibility of applying such an illusionary characteristic of the movie as a methodology of space design by utilizing the characteristic as a conceptual language of space design.

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Analysis of Microstructure and Thermal Conductivity of Concrete Thermal Energy Storage based on Amount of Graphite Mixture (그라파이트 혼입량에 따른 에너지 저장 콘크리트의 미세구조 및 열전도도 분석)

  • Kim, Se-Yun;Kim, Sung-Jo;Suh, Jeewoo;Han, Tong-Seok
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.5
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    • pp.293-300
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    • 2021
  • In this study, the microstructure and thermal conductivity correlation was investigated for concrete materials used in concrete thermal energy storage (CTES) among real-time energy storage devices. Graphite was used as admixture to increase the thermal conductivity performance of the CTES. Concrete specimens of 10% and 15% substitution of cement by mass with graphite, as well as ordinary portland cement (OPC) specimens were prepared, and the microstructural changes and effects on thermal conductivity were analyzed. Porosities of OPC and concrete with graphite were compared using micro-CT, and the microstructural characteristics were quantified using probability functions. Three-dimensional virtual specimens were constructed for thermal analysis, to confirm the effect of microstructural characteristics on thermal conductivity, and the results were compared with the measured conductivity obtained using the hot-disc method. To identify thermal conductivity of graphite for thermal analysis, solid phase conductivity was inversely determined based on simulation and experimental results, and the effect of graphite on thermal conductivity was analyzed.

Visual Media Education in Visual Arts Education (미술교육에 있어서 시각적 미디어를 통한 조형교육에 관한 연구)

  • Park Ji-Sook
    • Journal of Science of Art and Design
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    • v.7
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    • pp.64-104
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    • 2005
  • Visual media transmits image and information reproduced in large quantities, such as a photography, film, television, video, advertisement, or computer image. Correspondence to the students' reception and recognition of culture in the future. arrangements for the field of studies of visual culture. 'Visual Culture' implies cultural phenomena of visual images via visual media, which includes not only the categories of traditional arts like a painting, sculpture, print, or design, but the performance arts including a fashion show or parade of carnival, and the mass and electronic media like a photography, film, television, video, advertisement, cartoon, animation, or computer image. In the world of visual media, Image' functions as an essential medium of communication. Therefore, people call the culture of today fra of Image Culture', which has been converted from an alphabet convergence era to an image convergence one. Image, via visual media, has become a dominant means for communication in large part of human life, so we can designate an Image' as a typical aspect of visual culture today. Image, as an essential medium of communication, plays an important role in contemporary society. The one way is the conversion of analogue image like an actual picture, photograph, or film into digital one through the digitalization of digital camera or scanner as 'an analogue/digital commutator'. The other is a way of process with a computer drawing, or modeling of objects. It is appropriate to the production of pictorial and surreal images. Digital images, produced by the other, can be divided into the form of Pixel' and form of Vector'. Vector is a line linking the point of departure to the point of end, which organizes informations. Computer stores each line's standard location and correlative locations to one another Digital image shows for more 'Perfectness' than any other visual media. Digital image has been evolving in the diverse aspects, such as a production of geometrical or organic image compositing, interactive art, multimedia art, or web art, which has been applied a computer as an extended trot of painting. Someone often interprets digitalized copy with endless reproduction of original even as an extension of a print. Visual af is no longer a simple activity of representation by a painter or sculptor, but now is intimately associated with a matter of application of media. There is some problem in images via visual media. First, the image via media doesn't reflect a reality as it is, but reflects an artificial manipulated world, that is, a virtual reality. Second, the introduction of digital effect and the development of image processing technology have enhanced a spectacle of destructive and violent scenes. Third, a child intends to recognize the interactive images of computer game and virtual reality as a reality, or truth. Education needs not only to point out an ill effect of mass media and prevent the younger generation from being damaged by it, but also to offer a knowledge and know-how to cope actively with social, cultural circumstances. Visual media education is one of these essential methods for the contemporary and future human being in the overflowing of image informations. The fosterage of 'Visual Literacy' can be considered as a very purpose of visual media education. This is a way to lead an individual to the discerning, active consumer and producer of visual media in life as far as possible. The elements of 'Visual Literacy' can be divided into a faculty of recognition related to the visual media, a faculty of critical reception, a faculty of appropriate application, a faculty of active work and a faculty of creative modeling, which are promoted at the same time by the education of 'visual literacy'. In conclusion, the education of 'Visual Literacy' guides students to comprehend and discriminate the visual image media carefully, or receive them critically, apply them properly, or produce them creatively and voluntarily. Moreover, it leads to an artistic activity by means of new media. This education can be approached and enhanced by the connection and integration with real life. Visual arts and education of them play an important role in the digital era depended on visual communications via image information. Visual me야a of day functions as an essential element both in daily life and in arts. Students can soundly understand visual phenomena of today by means of visual media, and apply it as an expression tool of life culture as well. A new recognition and valuation visual image and media education is required to cultivate the capability of active, upright dealing with the changes of history of civilization. 1) Visual media education helps to cultivate a sensibility for images, which reacts to and deals with the circumstances. 2) It helps students to comprehend the contemporary arts and culture via new media. 3) It supplies a chance of students' experiencing a visual modeling by means of new media. 4) There are educational opportunities of images with temporality and spaciality, and therefore a discerning person becomes to increase. 5) The modeling activity via new media leads students to be continuously interested in the school and production of plastic arts. 6) It raises the ability of visual communications dealing with image information society. 7) An education of digital image is significant in respect of cultivation of man of talent for the future society of image information as well. To correspond to the changing and developing social, cultural circumstances, and the form and recognition of students' reception of them, visual arts education must arrange the field of studying on a new visual culture. Besides, a program needs to be developed, which is in more systematic and active level in relation to visual media education. Educational contents should be extended to the media for visual images, that is, photography, film, television, video, computer graphic, animation, music video, computer game and multimedia. Every media must be separately approached, because they maintain the modes and peculiarities of their own according to the conveyance form of message. The concrete and systematic method of teaching and the quality of education must be researched and developed, centering around the development of a course of study. Teacher's foundational capability of teaching should be cultivated for the visual media education. In this case, it must be paid attention to the fact that a technological level of media is considered as a secondary. Because school education doesn't intend to train expert and skillful producers, but intends to lay stress on the essential aesthetic one with visual media under the social and cultural context, in respect of a consumer including a man of culture.

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