• Title/Summary/Keyword: 공간뼈대

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Design of Behavioral Classification Model Based on Skeleton Joints (Skeleton Joints 기반 행동 분류 모델 설계)

  • Cho, Jae-hyeon;Moon, Nam-me
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.10a
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    • pp.1101-1104
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    • 2019
  • 키넥트는 RGBD 카메라로 인체의 뼈대와 관절을 3D 공간에서 스켈레톤 데이터수집을 가능하게 해주었다. 스켈레톤 데이터를 활용한 행동 분류는 RNN, CNN 등 다양한 인공 신경망으로 접근하고 있다. 본 연구는 키넥트를 이용해서 Skeleton Joints를 수집하고, DNN 기반 스켈레톤 모델링 학습으로 행동을 분류한다. Skeleton Joints Processing 과정은 키넥트의 Depth Map 기반의 Skeleton Tracker로 25가지 Skeleton Joints 좌표를 얻고, 학습을 위한 전처리 과정으로 각 좌표를 상대좌표로 변경하고 데이터 수를 제한하며, Joint가 트래킹 되지 않은 부분에 대한 예외 처리를 수행한다. 스켈레톤 모델링 학습 과정에선 3계층의 DNN 신경망을 구축하고, softmax_cross_entropy 함수로 Skeleton Joints를 집는 모션, 내려놓는 모션, 팔짱 낀 모션, 얼굴을 가까이 가져가는 모션 해서 4가지 행동으로 분류한다.

Fast Visualization of Soft Objects Using Interval Tree (인터벌트리를 이용한 소프트 물체의 빠른 가시화)

  • Min, Gyeong-Ha;Lee, In-Gwon;Park, Chan-Mo
    • Journal of the Korea Computer Graphics Society
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    • v.7 no.1
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    • pp.1-9
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    • 2001
  • We present a scheme and a data structure that decompose the space into adaptive-sized cells to improve the visualization of soft objects. Soft objects are visualized through the evaluation of the field functions at every point of the space. According to the propsed scheme, the affecting soft objects for a point in the space is searched through the data structure called interval tree based on the bounding volume of the components, which represent a soft object whose defining primitive(skeleton) is a simple geometric object such as point or line segment. The bounding volume of each component is generated with respect to the radius of a local field function of the component, threshold value, and the relations between the components and other neighboring components. The proposed scheme can be used in many applications for soft objects such as modeling and rendering, especially in interactive modeling process.

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A Study on the Practical Use of 3D Typography in Time and Space within the Context of Visual Communication: Focused on the 3D Typography Project Series Entitled Rhetorical Space (비주얼 커뮤니케이션의 맥락에서 탐색한 3차원 타이포그래피의 시공간적 활용에 관한 연구: 3차원 타이포그래피 프로젝트 연작 <수사적 공간>을 중심으로)

  • Kim, Namoo
    • The Journal of the Korea Contents Association
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    • v.20 no.8
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    • pp.162-175
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    • 2020
  • The purpose of this study is to deal with practical investigation, which blends symbolism on spatio-temporal level-especially typography in three-dimensional environment-and the symbolism of written language in the context of visual communication. Up until now, typography research and education have mainly been centered on two-dimensional environment and printing technology, such as the paper. However, this study is the result of this researcher's direct design and implementation of projects on typography aside from paper. Accordingly, this study is to provide an opportunity to raise the level of reason and expression used in visual communication to a new level and to expand its scope. To ensure the efficient progress of the project, this study was to identify the structure, system, and process of communication first. Furthermore, this study was to investigate two-dimensional and three-dimensional typography as the backbone of visual communication. In addition, several representative 3D typography works are analyzed in context and used as the conceptual framework of the project conducted for this study. Based on these results, this research verifies and suggests the possibility practically and objectively by creating the project series entitled Rhetorical Space in 3D typography. In addition, this research gives an opportunity to visualize ideas aimed at the development of character-based visual language and visual communication design in the realm of the more spatial, physical, and three-dimensional public environment.

Vibration of Steel Composite Railway Bridges under High Speed Train (고속열차하중 하의 강합성형 철도교의 진동)

  • Chang, Sung Pil;Kwark, Jong Won;Ha, Sang Gil;Kim, Sung Il
    • Journal of Korean Society of Steel Construction
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    • v.10 no.4 s.37
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    • pp.577-587
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    • 1998
  • The influences of high speed train on the dynamic responses of steel composite railway bridges are investigated. The bridge system which has two I-girder and several cross beams is modeled with plate and frame elements. With assumption of concrete slabs are fully connected with steel girders, the offset between slabs and girders is modeled using constraint equation. The track system is modeled using beams on elastic foundation theory. And, the TGV train model is developed in 2-dimension considering bouncing and pitching motion. And braking action of vehicle is considered using speed dependent braking function. To investigate the behavior of bridges due to moving trains, parametric studies on the variation of natural frequency of bridge, speed parameter, vehicle modeling method, braking action of train, etc are performed.

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Resonance Phenomenon according to the relationship between Span Length of the Bridge and Effective Beating Interval of High-Speed Train (교량의 지간장과 고속전철하중 유효타격간격 사이의 관계에 따른 공진현상)

  • 김성일;곽종원;장승필
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.67-76
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    • 1999
  • Resonance of the bridge can be occurred with the coincidence between a natural frequency of the bridge and a crossing frequency of moving loads which is determined from the speed and effective beating interval of the vehicle. In case of the railway bridge, the effective beating interval of the vehicle is fixed under the passage of specific trains. In the present study, resonance and cancellation of the bridge subjected to moving high-speed train are analyzed with the variations of span length. A steel-concrete composite railway bridge is idealized by the combinations of plate elements and space frame elements. High-speed train is idealized with moving constant forces and a 3-dimensional full modelling. From analyzing dynamic responses of D.M.F of vertical displacement, maximum vertical acceleration of the slab, and end rotation according to the variations of span length of the bridge, design criteria of span length of the bridge which satisfies dynamic safety is discussed.

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An Assumed Strain Beam Element for Spatial Post-Buckling Analysis of Non-symmetric and Shear Flexible Thin-Walled Beams (박벽보의 3차원 후좌굴 해석을 위한 Locking-Free 보요소)

  • Lee, Kyoung-Chan;Kim, Moon-Young;Park, Jung-Il;Chang, Sung-Pil
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.6
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    • pp.719-730
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    • 2007
  • This study presents a thin-walled space frame element based on the classical Timoshenko beam theory. The element is derived according to the assumed strain field in order to resolve the shear-locking phenomenon. The shape function is developed in accordance with the strain field which is assumed to be constant at a 2-noded straight frame element. In this study, the geometrically nonlinear analysis applies the Corotational procedure in order to evaluate unbalanced loads. The bowing effect is also considered faithfully. Two numerical examples are given; monosymmetric curved and nonsymmetric straight cantilever. When these example structures behave lateral-torsional bucking, the critical loads are obtained by this study and ABAQUS shell elements. Also, the post-buckling behavior is examined. The results give good agreement between this study and ABAQUS shell.

Dynamic Analysis of Floating Bridge Subject to Earthquake Load Considering Multi-Support Excitation (다중지점 가진 효과를 고려한 부유식 교량의 지진응답 해석)

  • 권장섭;백인열;장승필
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.2
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    • pp.27-33
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    • 2004
  • Dynamic response analysis is conducted for a floating bridge subjected to multiple support earthquake excitation. The floating bridge used in this study is supported by discrete floating pontoons and horizontal pretension cables supported at both ends of the bridge. The bridge is modeled with finite elements and the hydrodynamic added mass and added damping due to the surrounding fluid around pontoons are obtained using boundary elements. During the analysis the concept of retardation function is utilized to consider the frequency dependency of the hydrodynamic coefficients. Multiple support excitation is introduced at both ends of the bridge and the time history response is compared to that of a simultaneous excitation. The results show that the multiple support excitation yields larger values in some responses. for example in cable tensions. than the sumultaneous excitation.

Vehicle-Bridge Interaction Analysis of Railway Bridges by Using Conventional Trains (기존선 철도차량을 이용한 철도교의 상호작용해석)

  • Cho, Eun Sang;Kim, Hee Ju;Hwang, Won Sup
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1A
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    • pp.31-43
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    • 2009
  • In this study, the numerical method is presented, which can consider the various train types and can solve the equations of motion for a vehicle-bridge interaction analysis by non-iteration procedure through formulating the coupled equations of motion. The coupled equations of motion for the vehicle-bridge interaction are solved by the Newmark ${\beta}$ of a direct integration method, and by composing the effective stiffness matrix and the effective force vector according to a analysis step, those can be solved with the same manner of the solving procedure of equilibrium equations in static analysis. Also, the effective stiffness matrix is reconstructed by the Skyline method for increasing the analysis effectiveness. The Cholesky's matrix decomposition scheme is applied to the analysis procedure for minimizing the numerical errors that can be generated in directly calculating the inverse matrix. The equations of motion for the conventional trains are derived, and the numerical models of the conventional trains are idealized by a set of linear springs and dashpots with 16 degrees of freedom. The bridge models are simplified by the 3 dimensional space frame element which is based on the Euler-Bernoulli theory. The rail irregularities of vertical and lateral directions are generated by the PSD functions of the Federal Railroad Administration (FRA). The results of the vehicle-bridge interaction analysis are verified by the experimental results for the railway plate girder bridges of a span length with 12 m, 18 m, and the experimental and analytical data are applied to the low pass filtering scheme, and the basis frequency of the filtering is a 2 times of the 1st fundamental frequency of a bridge bending.

A study on the awareness about "Dong-YI(東夷)" in Confucianism scripture (유교경전의 동이 인식에 관한 연구 - 13경 및 그 주석서를 중심으로 -)

  • Ham, HyunChan
    • The Journal of Korean Philosophical History
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    • no.30
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    • pp.123-159
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    • 2010
  • Dongyi (Chinese: 東夷; pinyin: $D{\bar{o}}ngy{\acute{i}}$; Wade-Giles: Tung-yi; literally "eastern 'barbarians'") was a collective term for people in eastern China and in the east of China. People referred to as Dongyi vary across the ages. The early Dongyi culture was one of earliest neolithic cultures in China. According to the earliest Chinese record, Zuo Zhuan, the Shang Dynasty was attacked by King Wu of Zhou, while attacking Dongyi, and collapsed afterwards Dongyi culture was one of the oldest neolithic cultures in China. Some Chinese scholars extend the historical use of Dongyi to prehistoric times, according to this belief, the neolithic culture correlates to Houli culture, Beixin culture, Dawenkou culture, Longshan culture and Yueshi culture, five evolutionary phases. Deliang He, thinks that Dongyi culture used to be one of the leading cultures in neolithic China. The writing system of Dongyi was one of the oldest writing systems in neolithic China. There are opinions that the 20 pictogram characters discovered in a Dongyi tomb (山東?縣大汶口墓葬) in Shangdong indictates some of the characters found, like "旦, 越, 斤, 皇, 封, 酒, 拍, ?", are still used in Chinese characters. There are also opinions that Dongyi people were the inventor of arrows. Some classic Chinese history records like Zuo Zhuan, Shuowen Jiezi, Classic of Rites, all have some similar records about this. [3][4] The legendary god of archery in Chinese mythology, Houyi, could also be a Dongyi leader. Based on archeology findings, Dongyi people's ancestral worship totem is bird-shaped. In the meantime, The fundamental thing that Koreans should do is to find out Korean identy. Koreans cannot achieve their goals unless they enforce politics economics, educations, etc. in harmony with their own identity. However, some people say that Koreans do not have any dentity on the grounds that there is no Korean traditional thought. This view is, however, absolutely absurd because it is impossible for a nation to exist for oner five thousand years without having it's own native characteristics. The most essential thought in Korean identity is Confucius' In(仁). In is originated from Yi(夷) or Yi-jok(夷族)'s heart. On this account, Confucius' In can be a precious thought to Korean people who have been suffering from many problem caused by the absence of Korean identity. If Korean could understand their original characteristics and if Korean couldrealize that their original characteristics are Confucius' In, then our culture and identity recovery of though may maximize efficiency of country and society development.

System Development of Cubsat SIGMA(KHUSAT-3)

  • Shin, Jehyuck;Lee, Seongwhan;Lee, Jung-Kyu;Lee, Hyojeong;Lee, Jeongho;Seo, Junwon;Shin, Youra;Jeong, Seonyeong;Cheon, Junghoon;Kim, Hanjun;Lim, Jeonghyun;Lee, Junmin;Jin, Ho;Nam, Uk-Won;Kim, Sunghwan;Lee, Regina;Kim, Hyomin;Lessard, Marc R.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.106-106
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    • 2014
  • SIGMA (Scientific cubesat with Instrument for Global Magnetic field and rAdiation)는 근 지구공간에서 우주방사선량 측정과 자기장 변화 검출의 과학적 목적과 교육적 목적을 가지고 개발하고 있는 초소형 큐브위성이다. $100mm{\times}100mm{\times}340.5mm$의 크기로 약 3.6 kg의 무게를 가지며, 탑재체는 방사선에 대하여 인체와 동일한 산란 흡수 특성을 가진 Tissue Equivalent Proportional Counter (TEPC)와 자기장 측정을 위한 Magnetometer (Mag)이다. 위성체는 구조계, 자세제어계, 전력계, 명령 및 데이터처리계, 통신계로 구성되어있다. 구조계는 위성의 뼈대인 Chassis와 Mag deployer로 이루어져있고, 위성의 안정적인 자세유지를 목적으로 Attitude Control System (ACS) Board와 Torque Coil이 자세제어계로 구성된다. 전력의 생산과 공급 및 충전은 태양전지판과 Electrical Power System (EPS), 리튬 배터리로 구성된 전력계에서 이뤄지며, 명령 및 데이터처리계는 On Board Computer (OBC)와 Instrument Interface board (IIB)를 중심으로 서브시스템의 명령체계와 데이터처리를 다룬다. 통신계는 Uplink인 VHF 안테나와 Downlink인 UHF, S-band 안테나로 구성되며 지상과 명령을 송수신한다. SIGMA는 타임인터럽트 기능을 활용한 Flight Software (FSW)로 운용되며 임무에 따른 6가지 모드의 시나리오로 위성을 운용한다. 이에 SIGMA의 개발과 테스트 결과를 소개한다. 본 큐브위성 개발기술을 바탕으로 향후 천문관측용 위성에도 활용할 예정이다.

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