• Title/Summary/Keyword: active contour

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A Study on Facial Wrinkle Detection using Active Appearance Models (AAM을 이용한 얼굴 주름 검출에 관한 연구)

  • Lee, Sang-Bum;Kim, Tae-Mook
    • Journal of Digital Convergence
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    • v.12 no.7
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    • pp.239-245
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    • 2014
  • In this paper, a weighted value wrinkle detection method is suggested based on the analysis on the entire facial features such as face contour, face size, eyes and ears. Firstly, the main facial elements are detected with AAM method entirely from the input screen images. Such elements are mainly composed of shape-based and appearance methods. These are used for learning the facial model and for matching the face from new screen images based on the learned models. Secondly, the face and background are separated in the screen image. Four points with the biggest possibilities for wrinkling are selected from the face and high wrinkle weighted values are assigned to them. Finally, the wrinkles are detected by applying Canny edge algorithm for the interested points of weighted value. The suggested algorithm adopts various screen images for experiment. The experiments display the excellent results of face and wrinkle detection in the most of the screen images.

CoMFA Analysis on Inhibitory Effect of $3{\beta}$-Hydroxy-12-oleanen-28-oic Acid Analogues on PTP-1B Activity and Prediction of Active Compounds ($3{\beta}$-Hydroxy-12-oleanen-28-oic Acid 유도체들의 PTP-1B 저해활성에 대한 CoMFA 분석과 활성 분자들의 예측)

  • Kim, Sang-Jin;Kim, Se-Gon;Sung, Nack-Do
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.34 no.2
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    • pp.109-115
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    • 2008
  • The comparative molecular field analyses(CoMFA) models between the substituents with changing groups($R_1{\sim}R_4$) of $3{\beta}$-hydroxy-12-oleanen-28-oic acid derivatives as substrate molecule and their inhibitory activities($pI_{50}$) against protein tyrosine phosphatase(PTP)-1B were derived and discussed quantitatively. The optimized CoMFA F1 model have best predictability and fitness($r^2_{cv.}=0.654$ and $r^2_{ncv.}=0.995$). The order of contribution ratio (%) with CoMFA fields on the inhibitory activities was a steric field(53.0%), electrostatic field(36.2%) and hydrophobic field(10.8%). From the analytical results of CoMFA contour maps, the inhibitory activities were dependent on the R4 group in substrate molecules. Particularly, the new active compounds(P1 & P2) with the inhibitory activity against melanin synthesis were expected.

Geometric Snakes for Triangular Meshes (삼각 메쉬를 위한 기하학 스네이크)

  • Lee, Yun-Jin;Lee, Seung-Yong
    • Journal of the Korea Computer Graphics Society
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    • v.7 no.3
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    • pp.9-18
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    • 2001
  • Feature detection is important in various mesh processing techniques, such as mesh editing, mesh morphing, mesh compression, and mesh signal processing. In this paper, we propose a geometric snake as an interactive tool for feature detection on a 3D triangular mesh. A geometric snake is an extension of an image snake, which is an active contour model that slithers from its initial position specified by the user to a nearby feature while minimizing an energy functional. To constrain the movement of a geometric snake onto the surface of a mesh, we use the parameterization of the surrounding region of a geometric snake. Although the definition of a feature may vary among applications, we use the normal changes of faces to detect features on a mesh.

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Pharmacophore-Based Comparative Molecular Similarity Indices Analysis of CRTh2 Antagonists

  • Babu, Sathya
    • Journal of Integrative Natural Science
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    • v.8 no.4
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    • pp.273-284
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    • 2015
  • Chemoattractant Receptor Homologous molecule expressed on Th2 cells (CRTh2) is a chemoattractant receptor with seven transmembrane helices targeted for inflammatory diseases such as asthma and allergic rhinitis. In this study, pharmacophore based Comparative Molecular Similarity Indices Analysis (CoMSIA) were performed on the series of 2-(2-(benzylthio)-1H-benzo[d]imidazol-1-yl) acetic acids derivatives. Initially, GASP module was used for generation of pharmacophore models using five highly active compounds from the dataset. Among the generated pharmacophores, the best pharmacophore model was selected based on fitness score and was used as template for the alignment of compounds which was used for CoMSIA analysis. The best predictions were obtained utilizing steric, hydrophobic and H-bond acceptor parameters showing a $q^2$=0.559 and $r^2$=0.730. 15 test set compounds was used to investigate the predictive ability of the CoMSIA model. Contour maps suggested that presence of bulky substituents and H-bond acceptor atoms at $5^{th}$ position of benzene ring will increase the activity of the compounds. The results obtained from this study will be useful to design more potent CRTh2 antagonists.

Pharmacophore Based Comparative Molecular Field Analysis of CRTh2 Antagonists

  • Babu, Sathya;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.8 no.2
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    • pp.89-98
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    • 2015
  • Chemoattractant receptor homologous molecule expressed on Th2 cells (CRTh2) is a G-protein coupled receptor targeted for inflammatory diseases such as asthma, allergic rhinitis and atopic dermatitis. In this study, pharmacophore modeling and comparative molecular field analysis (CoMFA) were performed on the series of 2-(2-(benzylthio)-1H-benzo[d]imidazol-1-yl) acetic acids derivatives. Five highly active compounds were used for generation of pharmacophore models using GASP module. The best pharmacophore model was selected and used as template for the alignment of compounds which was used for CoMFA analysis. The best predictions obtained for CoMFA was $q^2=0.545$, $r^2=0.756$. The predictive ability of the model was investigated using 15 test set compounds. Contour maps suggested that presence of bulky substituents at $5^{th}$ position of benzene ring connected to suphur atoms attached to imidazol ring will increase the activity of the compounds. The results obtained from this study will be useful to design more potent CRTh2 antagonists.

Extraction of Human Body Using Hybrid Silhouette Extraction Method in Intelligent Robot System (지능형 로봇 시스템에서 하이브리드 실루엣 추출 방법을 이용한 인간의 몸 추출)

  • Kim Moon Hwan;Joo Young Hoon;Park Jin Bae;Cho Young Jo;Chi Su Young;Kim hye Jin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.7
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    • pp.852-857
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    • 2005
  • This paper discusses a human body extraction method for intelligent robot system. The intelligent robot system requires more robust silhouette extraction method because it has internal vibration and low resolution. The new hybrid silhouette extraction method is proposed to overcome this constrained environment. The temporal and gradient information is combined as hybrid silhouette. The motion region model is used to adjust combining parameters in hybrid silhouette. Finally, the experimental results show the superiority of the proposed method.

Facial Feature Extraction for Face Expression Recognition (얼굴 표정인식을 위한 얼굴요소 추출)

  • 이경희;고재필;변혜란;이일병;정찬섭
    • Science of Emotion and Sensibility
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    • v.1 no.1
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    • pp.33-40
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    • 1998
  • 본 논문은 얼굴인식 분야에 있어서 필수 과정인 얼굴 및 얼굴의 주요소인 눈과 입의 추출에 관한 방법을 제시한다. 얼굴 영역 추출은 복잡한 배경하에서 움직임 정보나 색상정보를 사용하지 않고 통계적인 모델에 기반한 일종의 형찬정합 방법을 사용하였다. 통계적인 모델은 입력된 얼굴 영상들의 Hotelling변환 과정에서 생성되는 고유 얼굴로, 복잡한 얼굴 영상을 몇 개의 주성분 갑으로 나타낼 수 있게 한다. 얼굴의 크기, 영상의 명암, 얼굴의 위치에 무관하게 얼굴을 추출하기 위해서, 단계적인 크기를 가지는 탐색 윈도우를 이용하여 영상을 검색하고 영상 강화 기법을 적용한 후, 영상을 고유얼굴 공간으로 투영하고 복원하는 과정을 통해 얼굴을 추출한다. 얼굴 요소의 추출은 각 요소별 특성을 고려한 엣지 추출과 이진화에 따른 프로젝션 히스토그램 분석에 의하여 눈과 입의 경계영역을 추출한다. 얼굴 영상에 관련된 윤곽선 추출에 관한 기존의 연구에서 주로 기하학적인 모양을 갖는 눈과 입의 경우에는 주로 가변 템플릿(Deformable Template)방법을 사용하여 특징을 추출하고, 비교적 다양한 모양을 갖는 눈썹, 얼굴 윤곽선 추출에는 스네이크(Snakes: Active Contour Model)를 이용하는 연구들이 이루어지고 있는데, 본 논문에서는 이러한 기존의 연구와는 달리 스네이크를 이용하여 적절한 파라미터의 선택과 에너지함수를 정의하여 눈과 입의 윤곽선 추출을 실험하였다. 복잡한 배경하에서 얼굴 영역의 추출, 추출된 얼굴 영역에서 눈과 입의 영역 추출 및 윤곽선 추출이 비교적 좋은 결과를 보이고 있다.

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Effects of Noise Power Uncertainty on Energy Detection for Spectrum Sensing (잡음 전력의 불확실성이 에너지 검파 기반의 스펙트럼 감지에 미치는 영향)

  • Lim, Chang-Heon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.11
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    • pp.22-27
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    • 2011
  • In spectrum sensing, an energy detector compares the energy of a received signal with a predetermined detection threshold and decides whether a primary user is active or not in a licensed frequency band. Here the detection threshold is related to the noise power level in the band. Most previous works on energy detection have assumed that the noise power is exactly known a priori. However, this assumption does not hold in practice since there may be some uncertainty about the noise power. So it is necessary to investigate its effects on the performance of energy detection for spectrum sensing. In this paper, we analyze the effects using the residue theorem for contour integral and present the associated numerical results.

Pedestrians Action Interpretation based on CUDA for Traffic Signal Control (교통신호제어를 위한 CUDA기반 보행자 행동판단)

  • Lee, Hong-Chang;Rhee, Sang-Yong;Kim, Young-Baek
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.5
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    • pp.631-637
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    • 2010
  • In this paper, We propose a method of motion interpretation of pedestrian for active traffic signal control. We detect pedestrian object in a movie of crosswalk area by using the code book method and acquire contour information. To do this stage fast, we use parallel processing based on CUDA (Compute Unified Device Architecture). And we remove shadow which causes shape distortion of objects. Shadow removed object is judged by using the hilbert scan distance whether to human or noise. If the objects are judged as a human, we analyze pedestrian objects' motion, face area feature, waiting time to decide that they have intetion to across a crosswalk for pdestrians. Traffic signal can be controlled after judgement.

Visual Tracking of Objects for a Mobile Robot using Point Snake Algorithm

  • Kim, Won;Lee, Choon-Young;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.30-34
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    • 1998
  • Path Planning is one of the important fields in robot technologies. Local path planning may be done in on-line modes while recognizing an environment of robot by itself. In dynamic environments to obtain fluent information for environments vision system as a sensing equipment is a one of the most necessary devices for safe and effective guidance of robots. If there is a predictor that tells what future sensing outputs will be, robot can respond to anticipated environmental changes in advance. The tracking of obstacles has a deep relationship to the prediction for safe navigation. We tried to deal with active contours, that is snakes, to find out the possibilities of stable tracking of objects in image plane. Snakes are defined based on energy functions, and can be deformed to a certain contour form which would converge to the minimum energy states by the forces produced from energy differences. By using point algorithm we could have more speedy convergence time because the Brent's method gives the solution to find the local minima fast. The snake algorithm may be applied to sequential image frames to track objects in the images by these characteristics of speedy convergence and robust edge detection ability.

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