• Title/Summary/Keyword: feature points

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A Study on a 3D Modeling for surface Inspection of a Moving Object (비등속 이동물체의 표면 검사를 위한 3D 모델링 기술에 관한 연구)

  • Ye, Soo-Young;Yi, Young-Youl;Nam, Ki-Gon
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.1
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    • pp.15-21
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    • 2007
  • We propose a 3D modeling method for surface inspection of non-constant velocity moving object. 1'lie laser lines reflect tile surface curvature. We can acquire 3D surface information by analyzing projected laser lines on object. In this paper, we use multi-line laser to improve the single stripe method and high speed of single frame. Binarization and edge extraction of frame image were proposed for robust laser each line extraction. A new labeling method was used for laser line labeling. We acquired some feature points for image matching from the frame data and juxtaposed the frames data to obtain a 3D shape image. We verified the superiority of proposed method by applying it to inspect container's damages.

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Image Mosaic using Multiresolution Wavelet Analysis (다해상도 웨이블렛 분석 기법을 이용한 영상 모자이크)

  • Yang, In-Tae;Oh, Myung-Jin;Lee, In-Yeub
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.2 s.29
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    • pp.61-66
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    • 2004
  • By the advent of the high-resolution Satellite imagery, there are increasing needs in image mosaicking technology which can be applied to various application fields such as GIS(Geographic Information system). To mosaic images, various methods such as image matching and histogram modification are needed. In this study, automated image mosaicking is performed using image matching method based on the multi-resolution wavelet analysis(MWA). Specifically, both area based and feature based matching method are embedded in the multi-resolution wavelet analysis to construct seam line.; seam points are extracted then polygon clipping method are applied to define overlapped area of two adjoining images. Before mosaicking, radiometric correction is proceeded by using histogram matching method. As a result, mosaicking area is automatically extracted by using polygon clipping method. Also, seamless image is acquired using multi-resolution wavelet analysis.

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Feature Extraction in an Aerial Photography of Gimnyeong Sand Dune Area by Texture Filtering (항공사진의 질감 분석을 통한 김녕사구지역의 지형지물 추출)

  • Chang Eun-Mi;Park Kyeong
    • Journal of the Korean Geographical Society
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    • v.41 no.2 s.113
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    • pp.139-149
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    • 2006
  • Earlier research works focused on the seasonal patterns and bio-geochemical processes in sand dunes, and the satellite data and aerial photographs have been used only as a backdrop or for the multi-temporal delineation of sand dune area. In order to find the optimal way to extract features' characteristics, Gimnyeong sand dune area was selected as a study site. Field works have been carried out three times to collect ground control points and sand samples for laboratory analyses. The texture of sand dune is classified as fine sand, which has been derived from shell fragments. The sand dune penetrated into the island from northwest to southeast direction. An aerial photograph was re-sampled into one-meter resolution and rectified with software including Erdas Imagine and ENVI. Sub-scenes were chosen as samples for sand dune, urban area and rural area. K-group non-parametric analysis had been done for the geometric and spectral values of enclosed texture patches. Urban areas proved to have significant smaller patches than the others.

A Study on Development of the Optimization Algorithms to Find the Seam Tracking (용접선 추적을 위한 최적화 알고리즘 개발에 관한 연구)

  • Jin, Byeong-Ju;Lee, Jong-Pyo;Park, Min-Ho;Kim, Do-Hyeong;Wu, Qian-Qian;Kim, Il-Soo;Son, Joon-Sik
    • Journal of Welding and Joining
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    • v.34 no.2
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    • pp.59-66
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    • 2016
  • The Gas Metal Arc(GMA) welding, called Metal Inert Gas(MIG) welding, has been an important component in manufacturing industries. A key technology for robotic welding processes is seam tracking system, which is critical to improve the welding quality and welding capacities. The objectives of this study were to develop the intelligent and cost-effective algorithms for image processing in GMA welding which based on the laser vision sensor. Welding images were captured from the CCD camera and then processed by the proposed algorithm to track the weld joint location. The proposed algorithms that commonly used at the present stage were verified and compared to obtain the optimal one for each step in image processing. Finally, validity of the proposed algorithms was examined by using weld seam images obtained with different welding environments for image processing. The results proved that the proposed algorithm was quite excellent in getting rid of the variable noises to extract the feature points and centerline for seam tracking in GMA welding and could be employed for general industrial application.

Functions of TET Proteins in Hematopoietic Transformation

  • Han, Jae-A;An, Jungeun;Ko, Myunggon
    • Molecules and Cells
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    • v.38 no.11
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    • pp.925-935
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    • 2015
  • DNA methylation is a well-characterized epigenetic modification that plays central roles in mammalian development, genomic imprinting, X-chromosome inactivation and silencing of retrotransposon elements. Aberrant DNA methylation pattern is a characteristic feature of cancers and associated with abnormal expression of oncogenes, tumor suppressor genes or repair genes. Ten-eleven-translocation (TET) proteins are recently characterized dioxygenases that catalyze progressive oxidation of 5-methylcytosine to produce 5-hydroxymethylcytosine and further oxidized derivatives. These oxidized methylcytosines not only potentiate DNA demethylation but also behave as independent epigenetic modifications per se. The expression or activity of TET proteins and DNA hydroxymethylation are highly dysregulated in a wide range of cancers including hematologic and non-hematologic malignancies, and accumulating evidence points TET proteins as a novel tumor suppressor in cancers. Here we review DNA demethylation-dependent and -independent functions of TET proteins. We also describe diverse TET loss-of-function mutations that are recurrently found in myeloid and lymphoid malignancies and their potential roles in hematopoietic transformation. We discuss consequences of the deficiency of individual Tet genes and potential compensation between different Tet members in mice. Possible mechanisms underlying facilitated oncogenic transformation of TET-deficient hematopoietic cells are also described. Lastly, we address non-mutational mechanisms that lead to suppression or inactivation of TET proteins in cancers. Strategies to restore normal 5mC oxidation status in cancers by targeting TET proteins may provide new avenues to expedite the development of promising anti-cancer agents.

The opinions of students about level-based class and improving methods about level-based instruction on mathematics (수학과 수준별 이동수업에 대한 학생들의 인식과 수준별 이동수업의 개선방안)

  • Seo, Hyun-Kyoung
    • Communications of Mathematical Education
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    • v.22 no.3
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    • pp.253-273
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    • 2008
  • The key feature of the $7^{th}$ Education curriculum, which is applied by order by year from 2000, is represented by differentiated curriculum. In order to embody differentiated curriculum, it is extensively recommended the level-based instruction. Level-based class basically has purposes to give students matched study experiences in accordance with their abilities and to help all students to understand what they have learned through providing differentiated instruction with considering the learners' stand points. The preceding researches have reported many cases about operating methods and educational effectiveness for the level-based instruction. In the meantime, researches about students' acceptances or opinions related to the level-based instruction are not sufficient. In this research, students opinions about level-based instruction are analyzed, based on the distinction of sex and level, and improving operational methods are suggested.

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Chronic cerebral hypoperfusion and plasticity of the posterior cerebral artery following permanent bilateral common carotid artery occlusion

  • Cho, Kyung-Ok;Kim, Seul-Ki;Kim, Seong Yun
    • The Korean Journal of Physiology and Pharmacology
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    • v.21 no.6
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    • pp.643-650
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    • 2017
  • Vascular dementia (VaD) is a group of heterogeneous diseases with the common feature of cerebral hypoperfusion. To identify key factors contributing to VaD pathophysiology, we performed a detailed comparison of Wistar and Sprague-Dawley (SD) rats subjected to permanent bilateral common carotid artery occlusion (BCCAo). Eight-week old male Wistar and SD rats underwent BCCAo, followed by a reference memory test using a five-radial arm maze with tactile cues. Continuous monitoring of cerebral blood flow (CBF) was performed with a laser Doppler perfusion imaging (LDPI) system. A separate cohort of animals was sacrificed for evaluation of the brain vasculature and white matter damage after BCCAo. We found reference memory impairment in Wistar rats, but not in SD rats. Moreover, our LDPI system revealed that Wistar rats had significant hypoperfusion in the brain region supplied by the posterior cerebral artery (PCA). Furthermore, Wistar rats showed more profound CBF reduction in the forebrain region than did SD rats. Post-mortem analysis of brain vasculature demonstrated greater PCA plasticity at all time points after BCCAo in Wistar rats. Finally, we confirmed white matter rarefaction that was only observed in Wistar rats. Our studies show a comprehensive and dynamic CBF status after BCCAo in Wistar rats in addition to severe PCA dolichoectasia, which correlated well with white matter lesion and memory decline.

A New Hybrid Evolutionary Programming Technique Using Sub-populations with Different Evolutionary Behaviors and Its Application to Camera Calibration (서로 다른 진화 특성을 가지는 부집단들을 사용한 새로운 하이브리드 진화 프로그래밍 기법과 카메라 보정 응용)

  • 조현중;오세영;최두현
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.35C no.9
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    • pp.81-92
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    • 1998
  • A new hybrid technique using several sub-populations having completely different evolutionary behaviors is proposed to increase the possibility to quickly find the global optimum of continuous optimization problem. It has three sub-populations. Two NPOSA algorithms showing good performance in the problem having a rugged fitness function are applied to two sub-populations and a self-adaptive evolutionary algorithm to the other sub-population. Sub-populations evolve in different manners and the interaction among these sub-populations lead to the global optimum quickly. The efficiency of this technique is verified through benchmark test functions. Finally, the algorithm with three sub-populations has been applied to seek for the optimal camera calibration parameters. After an error function has been defined using measured feature points of a calibration block, it has been shown that the algorithm searches for the camera parameters that minimize the error function.

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Fusion algorithm for Integrated Face and Gait Identification (얼굴과 발걸음을 결합한 인식)

  • Nizami, Imran Fareed;An, Sung-Je;Hong, Sung-Jun;Lee, Hee-Sung;Kim, Eun-Tai;Park, Mig-Non
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.1
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    • pp.72-77
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    • 2008
  • Identification of humans from multiple view points is an important task for surveillance and security purposes. For optimal performance the system should use the maximum information available from sensors. Multimodal biometric systems are capable of utilizing more than one physiological or behavioral characteristic for enrollment, verification, or identification. Since gait alone is not yet established as a very distinctive feature, this paper presents an approach to fuse face and gait for identification. In this paper we will use the single camera case i.e both the face and gait recognition is done using the same set of images captured by a single camera. The aim of this paper is to improve the performance of the system by utilizing the maximum amount of information available in the images. Fusion in considered at decision level. The proposed algorithm is tested on the NLPR database.

Multiresolution 3D Facial Model Compression (다해상도 3D 얼굴 모델의 압축)

  • 박동희;이종석;이영식;배철수
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.602-607
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    • 2002
  • In this paper, we proposed an approach to efficiently compress and transmit multiresoltion 3D lariat models for multimedia and very low bit rate applications. A personal facial model is obtained by a 3D laser digitizer, and further re-quantized at several resolutions according to different scope of applications, such as animation, video game, and video conference. By deforming 2D templates to match and re-quantize a 3D digitized facial model, we obtain its compressed model. In the present study, we create hierarchical 2D lariat wireframe templates are adapted according to facial feature points and the proposed piecewise chainlet affined transformation(PACT) method. The 3D digitized model after requantization are reduced significantly without perceptual loss. Moreover the proposed multiresoulation lariat models possessed of hierarchial data structure are apt to be progressively transmitted and displayed across internet.

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