• 제목/요약/키워드: Skeleton Point

검색결과 54건 처리시간 0.023초

다양체 기반의 변위곡면 (A Surface Displaced From a Manifold)

  • 윤승현;김명수
    • 한국컴퓨터그래픽스학회논문지
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    • 제12권1호
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    • pp.1-7
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    • 2006
  • 본 논문에서는 다양체 (manifold) 구조와 스칼라 변위함수 (scalar displacement function)에 기반한 새로운 변위곡면 (displaced surface)의 표현 기법을 제안한다. 변위곡면은 제어메쉬 (control mesh)의 각 정점에서 변위된 국소적 패치들 (displaced local patches)을 블렌딩 (blending)함으로써 생성된다. 제안된 변위곡면은 점 군 (point cloud)의 형태로 주어진 기하학적 모델을 근사하기 위해서 사용된다. 점 군의 데이터로터 제어메쉬가 생성되고, 점 군의 점들이 제어메쉬의 국소적 패치들 (local patches)에 사영 (projection)되어 각 패치들로 부터의 스칼라 변위함수가 구해지고, 이러한 변위함수들을 최적화 하여 높은 정밀도를 갖는 최종적인 곡면을 생성된다. 점 군의 형태로 주어진 다양한 모델에 대한 실험 결과를 통해서 제안된 근사기법의 효율성과 정밀도가 입증된다. 본 논문에서 제안된 표현기법은 다 단계 (multi-level) 변위함수를 통해 다중해상도 표현 (multi-resolution representations)과 골격기반 형상변형 (skeleton-driven deformation)등과 같은 다양한 응용들에 효율적으로 사용된다.

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손가락 마디지문 패턴을 이용한 개인식별 알고리즘 구현을 위한 경계 추적 알고리즘에 관한 연구 (A Study on A Boundary Tracking Algorithm for Finger Crease Pattern Identification Algorithm)

  • 정희철;신창호;이현열;최환수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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    • pp.818-820
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    • 1999
  • In this paper, a new boundary tracking algorithm for extracting finger area, which may be utilized by a finger crease pattern recognition algorithm, is proposed. Due to noise and irregular illumination, conventional algorithms for boundary tracking such as skeleton-based tracking methods were not suitable for typical boundary image of hand. So we propose a new finger boundary tracking algorithm utilizing a boundary-point-detection mask. We have observed that the proposed method provides stable and optimised boundary tracking.

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건축물의 내진설계에서 정적 비선형해석의 적용과 오차에 대한 고찰 (State-of-art on Its Application and Errors in Pushover Analysis of Building Structures)

  • 전대한;송호산
    • 한국공간구조학회논문집
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    • 제5권1호
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    • pp.99-105
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    • 2005
  • The pushover analysis is becoming a popular tool for seismic design of building structures. In this paper the state-of-art on static nonlinear analysis of building structures is presented with the emphasis on the effects of analysis parameters; i. e., lateral load patterns, modeling of members, and analysis computer programs. The analysed results may have variation even if a same structure is analysed. This paper is to investigate how large the variation is and what the main causes of the variation are. The difference of analysed results, the resultant variation of lateral story shear force and flexural strength of structural members are discussed. The pushover analysis procedure are routinely used in the seismic design of building structures, but some problems must yet be clarified, such as the effects to evaluate the parameters of analysis on the basis of a lateral load patterns and modeling of members.

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건축물의 내진설계에서 정적 비선형해석의 적용과 오차에 대한 고찰 (State-of-art on Its Application and Errors in Pushover Analysis of Building Structures)

  • 전대한;송호산
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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    • pp.103-110
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    • 2004
  • The pushover analysis is becoming a popular tool for seismic design of building structures. In this paper the state-of-art on static nonlinear analysis of building structures is presented with the emphasis on the effects of analysis parameters; i. e., lateral load patterns, modeling of members, and analysis computer programs. The analysed results may have variation even if a same structure is analysed. This paper is to investigate how large the variation is and what the main causes of the variation are. The difference of analysed results, the resultant variation of lateral story shear force and flexural strength of structural members are discussed. The pushover analysis procedure are routinely used in the seismic design of building structures, but some problems must yet be clarified, such as the effects to evaluate the parameters of analysis on the basis of a lateral load patterns and modeling of members.

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Realistic Visual Simulation of Water Effects in Response to Human Motion using a Depth Camera

  • Kim, Jong-Hyun;Lee, Jung;Kim, Chang-Hun;Kim, Sun-Jeong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권2호
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    • pp.1019-1031
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    • 2017
  • In this study, we propose a new method for simulating water responding to human motion. Motion data obtained from motion-capture devices are represented as a jointed skeleton, which interacts with the velocity field in the water simulation. To integrate the motion data into the water simulation space, it is necessary to establish a mapping relationship between two fields with different properties. However, there can be severe numerical instability if the mapping breaks down, with the realism of the human-water interaction being adversely affected. To address this problem, our method extends the joint velocity mapped to each grid point to neighboring nodes. We refine these extended velocities to enable increased robustness in the water solver. Our experimental results demonstrate that water animation can be made to respond to human motions such as walking and jumping.

3차원 포인트 클라우드 기반의 동적 3D 모델 생성을 위한 뼈대 추출 기술 (Skeleton extraction technique for producing 3D point cloud-based dynamic 3D model)

  • 박병서;김경진;서영호
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2019년도 하계학술대회
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    • pp.234-235
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    • 2019
  • 본 논문은 실사 객체를 360도 전방위에서 관찰이 가능한 3D 그래픽 모델로 변환하는 시스템에서 뼈대를 추출하는 방법을 제시한다. 각 카메라로부터 촬영된 텍스쳐 영상을 이용하여 뼈대를 추출하고, 깊이 정보로부터 얻어진 포인트 클라우드 정보를 이용하여 뼈대 정보를 정합, 보정하는 과정을 수행한다. 카메라로부터 촬영된 텍스쳐 영상에 대해 딥러닝 기술 등을 이용하여 뼈대를 획득한다. 텍스쳐 영상으로부터 획득된 뼈대 정보는 동일 위치에서 획득된 외부 파라미터를 이용하여 월드좌표계로 변환하여 공간상에 위치시킨다. 이러한 과정을 모든 카메라로부터 획득된 뼈대 정보에 동일하게 적용함으로써 모든 뼈대 정보를 공간상에 표현하여 최종적인 뼈대 정보를 추출하는 방법을 제시한다.

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안면골격 형태와 중심교합위-중심위 변위간의 상관성에 관한 연구 (RELATIONSHIP BETWEEN CO-CR DISCREPANCY AND FACIAL SKELETAL TYPE)

  • 조진영;이영준;박영국;정규림
    • 대한치과교정학회지
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    • 제28권5호
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    • pp.839-853
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    • 1998
  • 이 연구는 각 유형의 부정교합과 중심교합위-중심위 변위량 간의 상호관련성을 구명하기 위하여 시행되었다. 각 부정교합자 군에서 중심교합위-중심위 변위를 3차원적으로 비교 평가하고, 각 안면골격 형태의 특징에 따른 변위량의 차이 유무를 분석하고, 각 유형의 부정교합 골격형태에서 중심교합위-중심위 변위와 두개안면골격 계측요소 간의 상관성을 검정하였다. 242명의 부정교합자를 대상으로 중심교합위 상태에서 얻어진 측모두부X선규격사진을 계측하고 이들을 수평적, 수직적 관계에 의하여 9군으로 분류하였다. 또한 이들로부터 중심위와 중심교합위에서의 교합기록을 채득하고 face-bow로 안궁이전을 한 뒤 석고모형을 교합기에 중심위 상태로 탑재하였다. CPI를 이용하여 중심위와 중심교합위의 하악과두위치를 측정하고 이들과 각 군의 측모두부X선규격사진 계측치와의 상관성을 검정하기 위하여 통계처리한 결과 다음과 같은 결론을 얻었다. 1. 중심교합위-중심위 변위의 양과 방향에서 좌측과 우측은 증등도의 상관관계를 보였으며 전후방보다는 상하변위의 좌 우측 상관성이 다소 높았다. 2. II급 부정 교합군이 I 급과 III급 부정교합군에 비해 좌우측간의 중심 교합위-중심위 변위가 높은 상관관계를 보였다. 3. 각 부정교합군에서의 중심교합위-중심위 변위 유형은 유의한 차이가 없었다. 4. 중심교합위 상태의 측모두부X선규격사진상에서의 안면골격의 형태요소와 중심교합위-중심위 변위간에는 상관성이 적었다. 5. II급 brachyfacial skeleton과 III급 mesofacial skeleton의 일부 계측치에서 CPI수치를 예측할 수 있는 항목들이 나타났다. 중심교합위-중심위 변위의 양과 방향은 특정한 안면형태요소와는 무관하며 하악과두의 위치변이는 부정교합양태나 안면골격 형태와 관계없이 발현되었다.

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Analytical investigation on lateral load responses of self-centering walls with distributed vertical dampers

  • Huang, Xiaogang;Zhou, Zhen;Zhu, Dongping
    • Structural Engineering and Mechanics
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    • 제72권3호
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    • pp.355-366
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    • 2019
  • Self-centering wall (SCW) is a resilient and sustainable structural system which incorporates unbonded posttensioning (PT) tendons to provide self-centering (SC) capacity along with supplementary dissipators to dissipate seismic energy. Hysteretic energy dissipators are usually placed at two sides of SCWs to facilitate ease of postearthquake examination and convenient replacement. To achieve a good prediction for the skeleton curve of the wall, this paper firstly developed an analytical investigation on lateral load responses of self-centering walls with distributed vertical dampers (VD-SCWs) using the concept of elastic theory. A simplified method for the calculation of limit state points is developed and validated by experimental results and can be used in the design of the system. Based on the analytical results, parametric analysis is conducted to investigate the influence of damper and tendon parameters on the performance of VD-SCWs. The results show that the proposed approach has a better prediction accuracy with less computational effects than the Perez method. As compared with previous experimental results, the proposed method achieves up to 60.1% additional accuracy at the effective linear limit (DLL) of SCWs. The base shear at point DLL is increased by 62.5% when the damper force is increased from 0kN to 80kN. The wall stiffness after point ELL is reduced by 69.5% when the tendon stiffness is reduced by 75.0%. The roof deformation at point LLP is reduced by 74.1% when the initial tendon stress is increased from $0.45f_{pu}$ to $0.65f_{pu}$.

The capacity loss of a RCC building under mainshock-aftershock seismic sequences

  • Zhai, Chang-Hai;Zheng, Zhi;Li, Shuang;Pan, Xiaolan
    • Earthquakes and Structures
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    • 제15권3호
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    • pp.295-306
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    • 2018
  • Reinforced concrete containment (RCC) building has long been considered as the last barrier for keeping the radiation from leaking into the environment. It is important to quantify the performance of these structures and facilities considering extreme conditions. However, the preceding research on evaluating nuclear power plant (NPP) structures, particularly considering mainshock-aftershock seismic sequences, is deficient. Therefore, this manuscript serves to investigate the seismic fragility of a typical RCC building subjected to mainshock-aftershock seismic sequences. The implementation of the fragility assessment has been performed based on the incremental dynamic analysis (IDA) method. A lumped mass RCC model considering the tri-linear skeleton curve and the maximum point-oriented hysteretic rule is employed for IDA analyses. The results indicate that the seismic capacity of the RCC building would be overestimated without taking into account the mainshock-aftershock effects. It is also found that the seismic capacity of the RCC building decreases with the increase of the relative intensity of aftershock ground motions to mainshock ground motions. In addition, the effects of artificial mainshock-aftershock ground motions generated from the repeated and randomized approaches and the polarity of the aftershock with respect to the mainshock on the evaluation of the RCC are also researched, respectively.

기공(氣功)의 도인법(導引法)과 십이정경(十二正經)의 연관성(聯關性)에 관(關)한 고찰(考察) (A Study of the relation of Kigong(Doinbub) and 12 Jung-Kyung)

  • 김경환;윤종화
    • 대한의료기공학회지
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    • 제1권1호
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    • pp.111-148
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    • 1996
  • Recently, many study of the Kigong, but that is in the point of the view in Taoism and Ki itself. So, it thought that the study in comparison Kigong(Taoism) to Oriental Medicine is insufficient. I thought much of that there are many description of the movement and the effect in the the body in the old book written Taoism, Doinbub(Physical and breathing exercise), and that there are many relation 'the circulation of the Ki to 12 Jung-kyung(12 regular meridians). Then I give a report of the result that the study is compared in Taoism with in Oriental Medicine. The result were as follows ; 1. In the training of Doinbub, the effect is regulating muscle and skeleton, promote wi(constructive) system and ki(superficial) system, promote the ki and blood, strengthen the body resistance and dispel the invading pathogenic factors and preventive treatment. 2. In the training of Doinbub, the movements were much related to 12 regular Meridians and Muscles along the 12 meridians. 3. In the training of Doinbub, the effect were much related to 12 regular Meridians and Muscles along the 12 meridians. 4. It is possible that we set pathological syndrome to Doinbub(Physical and breathing exercise).