• 제목/요약/키워드: statistical reconstruction

검색결과 208건 처리시간 0.034초

Reconstruction of 3D Topography from Contour Line Data using Artificial Neural Networks (신경회로망을 이용한 등고선 데이터로부터 3차원 지형 복원)

  • Su-Sun Kim
    • Journal of the Korea Computer Industry Society
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    • 제2권3호
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    • pp.297-308
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    • 2001
  • We propose an algorithm which can reconstruct the 3D information from geographical information. The conventional techniques, the triangular patches and the Random Fractal Midpoint Displacement (RFMD) method, etc., have often been used to reconstruct natural images. While the RFMD method using Gaussian distribution obtains good results for the symmetric images, it is not reliable on asymmetric images immanent in the nature. Our proposed algorithm employs neural networks for the RFMD method to present the asymmetrical images. By using a neural network for reconstructing the 3D images, we can utilize statistical characteristics of irregular data. We show that our algorithm has a better performance than others by the point of view on the similarity evaluation. And, it seems that our method is more efficient for the mountainous topography which is more rough and irregular.

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Generalized Panoramic Scene Reconstruction from Video Sequences Based on Outlier Rejection (아웃라이어 배제에 기초한 일반화된 파노라마 영상 재구성)

  • 서종열;박종현;강문기
    • Journal of Broadcast Engineering
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    • 제6권2호
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    • pp.160-168
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    • 2001
  • In this paper, we propose a new practical motion model that can exploit the general properties of camera motion in constructing a panorama. accounting for panning. tilting, and evert the change in focal length of the camera. We also present an efficient algorithm to handle moving objects or noose in the scene based on outliers rejection. Spatial and temporal statistical properties of motion field are exploited to detect the outliers. The proposed algorithm removes moving objects or noise from the panoramic Image so that mode clear and complete view of the background Image can be obtained. This method does not require assumptions or a priors knowledge of the scene. The entire process is fully automatic as this method does not require any manual correction in the process of constructing a Panorama. The proposed algorithm is tested on the broadcasting images of soccer games. Oun simulation result shows that this method is superior to conventional image mosaicing algorithms.

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Identifying potential mergers of globular clusters: a machine-learning approach

  • Pasquato, Mario
    • The Bulletin of The Korean Astronomical Society
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    • 제39권2호
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    • pp.89-89
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    • 2014
  • While the current consensus view holds that galaxy mergers are commonplace, it is sometimes speculated that Globular Clusters (GCs) may also have undergone merging events, possibly resulting in massive objects with a strong metallicity spread such as Omega Centauri. Galaxies are mostly far, unresolved systems whose mergers are most likely wet, resulting in observational as well as modeling difficulties, but GCs are resolved into stars that can be used as discrete dynamical tracers, and their mergers might have been dry, therefore easily simulated with an N-body code. It is however difficult to determine the observational parameters best suited to reveal a history of merging based on the positions and kinematics of GC stars, if evidence of merging is at all observable. To overcome this difficulty, we investigate the applicability of supervised and unsupervised machine learning to the automatic reconstruction of the dynamical history of a stellar system. In particular we test whether statistical clustering methods can classify simulated systems into monolithic versus merger products. We run direct N-body simulations of two identical King-model clusters undergoing a head-on collision resulting in a merged system, and other simulations of isolated King models with the same total number of particles as the merged system. After several relaxation times elapse, we extract a sample of snapshots of the sky-projected positions of particles from each simulation at different dynamical times, and we run a variety of clustering and classification algorithms to classify the snapshots into two subsets in a relevant feature space.

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Mixed-Norm Patch Similarity Search for Self-Example-based Single Image Super-Resolution (자가 표본 기반 단일 영상 초해상도 복원을 위한 혼합 놈 패치 유사도 검색)

  • Oh, Jong-Geun;Hong, Min-Cheol
    • Journal of IKEEE
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    • 제22권2호
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    • pp.491-494
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    • 2018
  • This paper presents a similarity search method based on mixed norm for enhancing self-example-based single image super-resolution. In order to incorporate the local statistical characteristics of the patches into the super-resolution image reconstruction, we propose a method to determine the order of the norm according to the patch inclination and use it as a similarity search between patches. Experimental results demonstrate that the proposed similarity search method has the capability to improve the performance of existing search method.

Multiple Description Coding using Whitening Ttansform

  • Park, Kwang-Pyo;Lee, Keun-Young
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.1003-1006
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    • 2002
  • In the communications systems with diversity, we are commonly faced on needing of new source coding technique, error resilient coding. The error resilient coding addresses the coding algorithm that has the robustness to unreliability of communications channel. In recent years, many error resilient coding techniques were proposed such as data partitioning, resynchronization, error detection, concealment, reference picture selection and multiple description coding (MDC). Especially, the MDC using correlating transform explicitly adds correlation between two descriptions to enable the estimation of one set from the other. However, in the conventional correlating transform method, there is a critical problem that decoder must know statistics of original image. In this paper, we propose an enhanced method, the MDC using whitening transform that is not necessary additional statistical information to decode image because the DCT coefficients to apply whitening transform to an image have uni-variance statistics. Our experimental results show that the proposed method achieves a good trade-off between the coding efficiency and the reconstruction quality. In the proposed method, the PSNR of images reconstructed from two descriptions is about 0.7dB higher than conventional method at the 1.0 BPP and from only one description is about 1,8dB higher at the same rate.

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Three dimensional analysis of Korean dentogingival complex (한국인 치아치은 집합체구조의 삼차원적인 분석)

  • Park, Yeong-Suk;Lee, Seung-Pyo;Kim, Tae-Il
    • Journal of Periodontal and Implant Science
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    • 제38권2호
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    • pp.199-206
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    • 2008
  • Purpose: Variation in the morphology of gingival papilla may be determined by the shape and position of anatomic crown as well as contact area and embrasure form of individual teeth. However, periodontal biotype classification is regarded to be subjective because of the lack of definite criteria. In this study, we defined the objective parameters which constitute the periodontal biotype and measured their relationship. Materials and Methods: 109 of dental casts were prepared using three dimensional scanner and specialized reconstruction software, then acquiredvirtual models were sent to the 20 professional dentists to define the specific periodontal biotypes. Several parameters around periodontal structures were measured from the virtual models; facial surface area of the anterior tooth (AT), anterior papillary area (AP), proportion of the dento-papillary complex, clinical papillary length (PL), and clinical papillary angle (PA). Statistical analysis was performed to confirm the relationship among parameters. Results: Coincidence rate of periodontal biotype within observers was $63.77{\pm}16.05%$. Coincidence rate between observers was $76.15{\pm}16.43%$. Among the parameters measured, PL showed the most positive correlations and PA presented the most negative correlations. The parameter of the AP and PL of six maxillary anterior teeth showed significant correlation coefficient. Conclusion: Anterior papillary area and clinical papillary length would be objective parameters for determining the consistent periodontal biotypes.

Contour-Based Partial Object Recognition Of Elliptical Objects Using Symmetry (대칭특성을 이용한 타원형 객체의 외형기반 부분인식에 관한 연구)

  • Cho June-Suh
    • The KIPS Transactions:PartB
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    • 제13B권2호
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    • pp.115-120
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    • 2006
  • In This Paper, We Propose The Method To Reconstruct And Estimate Partially Occluded Elliptical Objects In Images From Overlapping And Cutting. We Present The Robust Method For Recognizing Partially Occluded Objects Based On Symmetry Properties, Which Is Based On The Contours Of Elliptical Objects. A Proposed Method Provides Simple Techniques To Reconstruct Occluded Regions Via A Region Copy Using The Symmetry Axis Within An Object. Based On The Estimated Parameters For Partially Occluded Objects, We Perform Object Recognition On The Classifier. Since A Proposed Method Relies On Reconstruction Of The Object Based On The Symmetry Properties Rather Than Statistical Estimates, It Has Proven To Be Remarkably Robust In Recognizing Partially Occluded Objects In The Presence Of Scale Changes, Object Pose, And Rotated Objects With Occlusion, Even Though h Proposed Method Has Minor Limitations Of Object Poses.

Measurement Method of the Masseter Muscle Volume Using 3D Computed Tomography (3D CT를 이용한 교근의 부피측정)

  • Baek, Jung Hwan;Choi, Jong Woo;Yoo, Sun Kuk;Kim, Yong Oock;Park, Beyoung Yun
    • Archives of Plastic Surgery
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    • 제32권5호
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    • pp.589-592
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    • 2005
  • Since G.N. Hounsfield's clinical use of computed tomography in 1971, digital imaging technique using computers has shown an eye opening progress. Progress has made 3-dimensional understanding of not only facial bones but muscles and other connective tissues possible through 3-dimensional reconstruction of preexisting tomographical images. Also, quantitative analysis of density, distance, volume has become possible, allowing objective analysis of preoperative and postoperative states through imaging. The authors measured the masseter muscle volume of 20 normal individuals and 8 female patients through 3-D reconstructive CT imaging and made a statistical analysis of the measurements. The method used in our study may be applied to the diagnosis of disease causing the change of the facial volume and presurgical design as a useful tool to provide objective information on the evaluation of surgery outcome.

Application of Compressive Sensing and Statistical Analysis to Condition Monitoring of Rotating Machine (압축센싱과 통계학적 기법을 적용한 회전체 시스템의 상태진단)

  • Lee, Myung Jun;Jeon, Jun Young;Park, Gyuhae;Kang, To;Han, Soon Woo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • 제26권6_spc호
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    • pp.651-659
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    • 2016
  • Condition monitoring (CM) encounters a large data problem due to sensors that measure vibration data with a continuous, and sometimes, high sampling rate. In this study, compressive sensing approaches for condition monitoring are proposed to demonstrate the efficiency in handling a large amount of data and to improve the damage detection capability of the current condition monitoring process. Compressive sensing is a novel sensing/sampling paradigm that takes much fewer samples compared to traditional sampling methods. For the experiments a built-in rotating system was used and all data were compressively sampled to obtain compressed data. Optimal signal features were then selected without the reconstruction process and were used to detect and classify damage. The experimental results show that the proposed method could improve the data processing speed and the accuracy of condition monitoring of rotating systems.

Defect Inspection of the Polarizer Film Using Singular Vector Decomposition (특이값 분해를 이용한 편광필름 결함 검출)

  • Jang, Kyung-Shik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • 제11권5호
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    • pp.997-1003
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    • 2007
  • In this paper, we propose a global approach for automatic inspection of defects in the polarizer film image. The proposed method does not rely on local feature of the defect. It is based on a global image reconstruction scheme using the singular value decomposition(SVD). SVD is used to decompose the image and then obtain a diagonal matrix of the singular values. Among the singular values, the first singular value is used to reconstruct a image. In reconstructed image, the normal pixels in background region have a different characteristics from the pixels in defect region. It is obtained the ratio of pixels in the reconstructed image to ones in the original image and then the defects are detected based on the the statistical process of the ratio. The experiment results show that the proposed method is efficient for defect inspection of polarizer lam image.