• Title/Summary/Keyword: back-projection method

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Observation on Neck Form of Young Japanese Women for Clothing DesignII-Analysis of Horizontal Sectional Neck Serface & Draft of Neck Serface Using 3-D Data- (의복설계를 위한 성인여성의 유형형태의 관찰II-3차원 계측법에 의한 유형의 횡단면도 및 체표면전개도의 분석 ,일본 여자대학생을 중심으로-)

  • 김희숙
    • Journal of the Korean Society of Costume
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    • v.36
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    • pp.139-148
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    • 1998
  • In order to know what sorts of features of neck form may be required to make plans for tight collars, the neck form of young japanese women were measured three demension-ally using GRASP(Grating Projection System for Profiling) and plaster torso. By the BASIC language in NEC computer and EXCEL program in MACINTOSHI computer, it became possible to draft a number of neck surface auomatically, therefore, we got analysis of a mass of subjects. Thed following results were obtained: 1. There was a large individual difference in the shape of neck, in particular, on the front and side curves of the neck base line, where the undulation of clavicular part of neck and inclination of shoulder are refracted. 2. When designing a stand collar, from the viewpoint of clothing strcture, it is important to grasp exactly the shapes of the neck, such as the line of the neck base, the neck gradient, back neck length, back neck width & girth. 3. According to the somatotypes(turing-over, standard, bending type), there were different the method of the basic collar pattern making.

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Critical Review of Reconstruction Filters for Convolution Algorithms (Convolution 알고리즘을 이용한 영상 재구성필터에 관한 연구)

  • 라종범
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.17 no.1
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    • pp.14-22
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    • 1980
  • The Fourier convolution algorithm is used to reconstruct a 34 density function from projection data sets. The convolved data are then back-projected to obtain a density function. There are several choices of the weighting function for the design of the reconstruction(deblurring) filter. Present Paper reviews the published reconstruction liters theoretically and proposes a new reconstructirm filter design method, considering the problems such as the effects of sampling rate, aliasing, and noise. Several previous reconstructirn filters are compared with the proposed filter by computer simulations.

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Microwave Incoherent Imaging of a Conducting Cylinder by using Multi-Frequency Time-Harmonic Field : Part II - Microwave Incoherent Imaging of a Conducting Cylinder (다중주파수 시간조화신호를 사용한 도체기둥의 초고주파 incoherent 영상 : Part II - 도체기둥의 초고주파 incohernet 영상)

  • 강진섭;라정웅
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.2
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    • pp.56-64
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    • 1996
  • In the previous paper of this study, an incoherent intensity pattern of a conducting cylinder is obtained by averaging out the multi-frequency intensities of the time-harmonic fields scattered from this cylinder. in this paper, an incoherent imaging of a conducting cylinder is obtained via the back-projection of the incoherent intensity patterns calculated from the circular rotational measurement configuration. This imaging method is vlaidated by imaging a conducting circular and a conducting elliptic cylinder and the measurement conditions to get better image are investigated.

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Trial of Computer Simulation of Image Reconstruction from Incomplete Data for New CT with Reduced Exposure

  • Hayakawa, Yoshinori;Furuya, Toshimitsu;Sakakibara, Norifumi
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.382-384
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    • 2002
  • Filtered-Back-Projection technique is used in X-ray CT image reconstruction. This requires X-ray transmission data from all directions. As the transverse cross-section of the body is approximately 50 cm, transmitted X-rays in this direction are strongly attenuated. If X-ray transmission data in this direction is avoided, exposure to the patients seems to be reduced one 20th of usual value. Some alternative method has to be found for clinically sufficient image quality. New methods are under development and tentative results are reported that utilizes the principle of superposition.

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Automatic Generation System for Quadrilateral Meshes on NURBS Surfaces (NURBS 곡면에서 사각형 요소망의 자동생성 시스템)

  • Kim, Hyung-Il;Park, Jang-Won;Kwon, Ki-Youn;Cho, Yun-Won;Chae, Soo-Won
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.894-899
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    • 2000
  • An automatic mesh generation system with unstructured quadrilateral elements on trimmed NURBS surfaces has been developed.. In this paper, NURBS surface geometries in the IGES format have been used to represent model shape. NURBS surface is represented as parametric surface. So each surface could be mapped to a 2D parametric plane through the parametric domain. And then meshes with quadrilateral elements are constructed in this plane. Finally, the constructed meshes are mapped back to the original 3D surface through the parametric domain. In this paper, projection plane, quasi-expanded plane and parametric Plane are used as 2D mesh generation plane. For mapping 3D surface to parametric domain, Newton-Rhapson Method is employed. For unstructured mesh generation with quadrilateral elements on 2D plane, a domain decomposition algorithm using loop operators has been employed. Sample meshes are represented to demonstrate the effectiveness of the proposed algorithm.

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The Noise Power Spectrum in Heavy Ion CT Based on Measurement of Residual Range Distribution

  • Yasuda, Naruomi;Abe, Shinji;Nishimura, Katsuyuki;Tomita, Tetsuya;Sato, Hitoshi;Muraishi, Hiroshi;Kanzaki, Takayuki;Inada, Tetsuo;Fujisaki, Tatsuya
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.228-230
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    • 2002
  • The relative electron density resolution was discussed by the noise power spectrum (NPS) in the heavy ion CT image. The heavy ion beam $\^$12/C accelerated up to 400MeV/u by RIMAC was used in this study. The two-dimensional (2-D) NPS in the CT image was obtained from the one-dimensional (1-D) NPS of the measured residual range distribution of water phantom for single projection, and the noise variance in the CT image was calculated from 2-D NPS. The technique used in the reconstruction was the filtered back-projection method with Shepp-Logan filter. The calculated value suggests the result of our previous works using the density resolution phantom, assuming that the relative electron density resolution is twice the standard deviation. Therefore, the estimation of the noise in CT images by 2-D NPS obtained the measured residual range distribution is the useful method.

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CT Image Reconstruction of Wood Using Ultrasound Velocities I - Effects of Reconstruction Algorithms and Wood Characteristics -

  • Kim, Kwang-Mo;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.5 s.133
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    • pp.21-28
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    • 2005
  • For the proper conservation of wooden cultural properties, non-destructive evaluation (NDE) method, which can be used to quantitatively evaluate the internal state of wood members, are needed. In this study, an ultrasonic CT system composed of portable devices was attempted, and the capacity of this system was verified by reconstructing the CT images for two phantoms and two artificially defected specimens. Results from this study showed that the sizes of detected defects were enlarged and the shapes were distorted on the CT images. Also, the positions were shifted somewhat toward the surface of specimen, which is regarded due to the anisotropic property of wood. Compared to the filtered back-projection method, SIRT (simultaneous iterative reconstruction technique) method was determined to be more efficient as the algorithm of image reconstruction for wood. A new ultrasonic CT system is thought to be used as a NDE method for wood. However wood characteristics and wave diffraction within wood made it difficult to accurately evaluate the size, shape and position of defects. To improve the quality of CT image of wood, more research including the relationship between wood and ultrasound is needed, and wood properties should be taken into consideration on the image reconstruction algorithm.

Efficient Object Localization using Color Correlation Back-projection (칼라 상관관계 역투영법을 적용한 효율적인 객체 지역화 기법)

  • Lee, Yong-Hwan;Cho, Han-Jin;Lee, June-Hwan
    • Journal of Digital Convergence
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    • v.14 no.5
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    • pp.263-271
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    • 2016
  • Localizing an object in image is a common task in the field of computer vision. As the existing methods provide a detection for the single object in an image, they have an utilization limit for the use of the application, due to similar objects are in the actual picture. This paper proposes an efficient method of object localization for image recognition. The new proposed method uses color correlation back-projection in the YCbCr chromaticity color space to deal with the object localization problem. Using the proposed algorithm enables users to detect and locate primary location of object within the image, as well as candidate regions can be detected accurately without any information about object counts. To evaluate performance of the proposed algorithm, we estimate success rate of locating object with common used image database. Experimental results reveal that improvement of 21% success ratio was observed. This study builds on spatially localized color features and correlation-based localization, and the main contribution of this paper is that a different way of using correlogram is applied in object localization.

Development of Cloud-Based Medical Image Labeling System and It's Quantitative Analysis of Sarcopenia (클라우드기반 의료영상 라벨링 시스템 개발 및 근감소증 정량 분석)

  • Lee, Chung-Sub;Lim, Dong-Wook;Kim, Ji-Eon;Noh, Si-Hyeong;Yu, Yeong-Ju;Kim, Tae-Hoon;Yoon, Kwon-Ha;Jeong, Chang-Won
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.7
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    • pp.233-240
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    • 2022
  • Most of the recent AI researches has focused on developing AI models. However, recently, artificial intelligence research has gradually changed from model-centric to data-centric, and the importance of learning data is getting a lot of attention based on this trend. However, it takes a lot of time and effort because the preparation of learning data takes up a significant part of the entire process, and the generation of labeling data also differs depending on the purpose of development. Therefore, it is need to develop a tool with various labeling functions to solve the existing unmetneeds. In this paper, we describe a labeling system for creating precise and fast labeling data of medical images. To implement this, a semi-automatic method using Back Projection, Grabcut techniques and an automatic method predicted through a machine learning model were implemented. We not only showed the advantage of running time for the generation of labeling data of the proposed system, but also showed superiority through comparative evaluation of accuracy. In addition, by analyzing the image data set of about 1,000 patients, meaningful diagnostic indexes were presented for men and women in the diagnosis of sarcopenia.

The motion estimation algorithm implemented by the color / shape information of the object in the real-time image (실시간 영상에서 물체의 색/모양 정보를 이용한 움직임 검출 알고리즘 구현)

  • Kim, Nam-Woo;Hur, Chang-Wu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2733-2737
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    • 2014
  • Motion detection according to the movement and the change area detection method according to the background difference and the motion history image for use in a motion estimation technique using a real-time image, the motion detection method according to the optical flow, the back-projection of the histogram of the object to track for motion tracking At the heart of MeanShift center point of the object and the object to track, while used, the size, and the like due to the motion tracking algorithm CamShift, Kalman filter to track with direction. In this paper, we implemented the motion detection algorithm based on color and shape information of the object and verify.