• Title/Summary/Keyword: image validation

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GLOBAL GENERALIZED CROSS VALIDATION IN THE PRECONDITIONED GL-LSQR

  • Chung, Seiyoung;Oh, SeYoung;Kwon, SunJoo
    • Journal of the Chungcheong Mathematical Society
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    • v.32 no.1
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    • pp.149-156
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    • 2019
  • This paper present the global generalized cross validation as the appropriate choice of the regularization parameter in the preconditioned Gl-LSQR method in solving image deblurring problems. The regularization parameter, chosen from the global generalized cross validation, with preconditioned Gl-LSQR method can give better reconstructions of the true image than other parameters considered in this study.

Deformable image registration in radiation therapy

  • Oh, Seungjong;Kim, Siyong
    • Radiation Oncology Journal
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    • v.35 no.2
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    • pp.101-111
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    • 2017
  • The number of imaging data sets has significantly increased during radiation treatment after introducing a diverse range of advanced techniques into the field of radiation oncology. As a consequence, there have been many studies proposing meaningful applications of imaging data set use. These applications commonly require a method to align the data sets at a reference. Deformable image registration (DIR) is a process which satisfies this requirement by locally registering image data sets into a reference image set. DIR identifies the spatial correspondence in order to minimize the differences between two or among multiple sets of images. This article describes clinical applications, validation, and algorithms of DIR techniques. Applications of DIR in radiation treatment include dose accumulation, mathematical modeling, automatic segmentation, and functional imaging. Validation methods discussed are based on anatomical landmarks, physical phantoms, digital phantoms, and per application purpose. DIR algorithms are also briefly reviewed with respect to two algorithmic components: similarity index and deformation models.

PRECONDITIONED GL-CGLS METHOD USING REGULARIZATION PARAMETERS CHOSEN FROM THE GLOBAL GENERALIZED CROSS VALIDATION

  • Oh, SeYoung;Kwon, SunJoo
    • Journal of the Chungcheong Mathematical Society
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    • v.27 no.4
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    • pp.675-688
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    • 2014
  • In this paper, we present an efficient way to determine a suitable value of the regularization parameter using the global generalized cross validation and analyze the experimental results from preconditioned global conjugate gradient linear least squares(Gl-CGLS) method in solving image deblurring problems. Preconditioned Gl-CGLS solves general linear systems with multiple right-hand sides. It has been shown in [10] that this method can be effectively applied to image deblurring problems. The regularization parameter, chosen from the global generalized cross validation, with preconditioned Gl-CGLS method can give better reconstructions of the true image than other parameters considered in this study.

Setting an Initial Validation Gate based on Signal Intensity for Target Tracking in IR Image Sequences (적외선 영상에서 표적 추적을 위한 신호세기 기반 초기 유효게이트 설정 방법)

  • Yang, Yu Kyung;Kim, Jieun;Lee, Boohwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.1
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    • pp.108-114
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    • 2014
  • This paper describes a method to set an intensity-based initial validation gate for tracking filter while preserves the ability of tracking a target with maximum speed. First, we collected real data set of signal versus distance of an airplane target. And at each data point, we computed maximum distance the target can move. And a function is modeled to expect the maximum moving pixels on the lateral direction based on the intensity of the detected target in IR image sequence. The initial prediction error covariance can be computed using this function to decide the size of the initial validation gate. The simulation results show the proposed method can set the appropriate initial validation gates to track the targets with the maximum speed.

Stellar Source Selections for Image Validation of Earth Observation Satellite

  • Yu, Ji-Woong;Park, Sang-Young;Lim, Dong-Wook;Lee, Dong-Han;Sohn, Young-Jong
    • Journal of Astronomy and Space Sciences
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    • v.28 no.4
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    • pp.273-284
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    • 2011
  • A method of stellar source selection for validating the quality of image is investigated for a low Earth orbit optical remote sensing satellite. Image performance of the optical payload needs to be validated after its launch into orbit. The stellar sources are ideal source points that can be used to validate the quality of optical images. For the image validation, stellar sources should be the brightest as possible in the charge-coupled device dynamic range. The time delayed and integration technique, which is used to observe the ground, is also performed to observe the selected stars. The relations between the incident radiance at aperture and V magnitude of a star are established using Gunn & Stryker's star catalogue of spectrum. Applying this result, an appropriate image performance index is determined, and suitable stars and areas of the sky scene are selected for the optical payload on a remote sensing satellite to observe. The result of this research can be utilized to validate the quality of optical payload of a satellite in orbit.

APPLICATION AND CROSS-VALIDATION OF SPATIAL LOGISTIC MULTIPLE REGRESSION FOR LANDSLIDE SUSCEPTIBILITY ANALYSIS

  • LEE SARO
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.302-305
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    • 2004
  • The aim of this study is to apply and crossvalidate a spatial logistic multiple-regression model at Boun, Korea, using a Geographic Information System (GIS). Landslide locations in the Boun area were identified by interpretation of aerial photographs and field surveys. Maps of the topography, soil type, forest cover, geology, and land-use were constructed from a spatial database. The factors that influence landslide occurrence, such as slope, aspect, and curvature of topography, were calculated from the topographic database. Texture, material, drainage, and effective soil thickness were extracted from the soil database, and type, diameter, and density of forest were extracted from the forest database. Lithology was extracted from the geological database and land-use was classified from the Landsat TM image satellite image. Landslide susceptibility was analyzed using landslide-occurrence factors by logistic multiple-regression methods. For validation and cross-validation, the result of the analysis was applied both to the study area, Boun, and another area, Youngin, Korea. The validation and cross-validation results showed satisfactory agreement between the susceptibility map and the existing data with respect to landslide locations. The GIS was used to analyze the vast amount of data efficiently, and statistical programs were used to maintain specificity and accuracy.

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Image Processing-based Validation of Unrecognizable Numbers in Severely Distorted License Plate Images

  • Jang, Sangsik;Yoon, Inhye;Kim, Dongmin;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.1 no.1
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    • pp.17-26
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    • 2012
  • This paper presents an image processing-based validation method for unrecognizable numbers in severely distorted license plate images which have been degraded by various factors including low-resolution, low light-level, geometric distortion, and periodic noise. Existing vehicle license plate recognition (LPR) methods assume that most of the image degradation factors have been removed before performing the recognition of printed numbers and letters. If this is not the case, conventional LPR becomes impossible. The proposed method adopts a novel approach where a set of reference number images are intentionally degraded using the same factors estimated from the input image. After a series of image processing steps, including geometric transformation, super-resolution, and filtering, a comparison using cross-correlation between the intentionally degraded reference and the input images can provide a successful identification of the visually unrecognizable numbers. The proposed method makes it possible to validate numbers in a license plate image taken under low light-level conditions. In the experiment, using an extended set of test images that are unrecognizable to human vision, the proposed method provides a successful recognition rate of over 95%, whereas most existing LPR methods fail due to the severe distortion.

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The Evaluation about the Information Fidelity in the External Image Information Input - Using DICOM Validation Tool - (외부영상정보 입력 시 DICOM정보 충실성에 대한 평가 - DICOM Validation Tool 이용 -)

  • Lee, Song-Woo;Lee, Ho-Yeon;Do, Ji-Hoon;Jang, Hye-Won
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.1
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    • pp.33-38
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    • 2011
  • Now a days, there's many change over for PACS among the most of hospital and it standard for DICOM 3.0. These kind of using of DICOM 3.0 improves increasing of medical imaging exchange and service for patient. However, there's some problems of compatibility caused during carry out CD and DVD from hospital. For this reason, this thesis analyzed patients image targeting those storages requested to hospitals in Seoul by using Validation Toolkit which is recommended from KFDA. The analyze type is like this. Make 100 data, total 500, each of MRI CT Plain x-ray Ultrasound PET-CT images and analyzed type of error occurred and loyalty of information. If express percentage of error occurred statistically, we can get a result as follows MRI 5%, Plain x-ray 11%, CT 18%, US 25%, PET-CT 30%. The reson why percentage of error occurred in PET-CT is because of imperfective support and we could notice that we weren't devoted to information. Even though, PET-CT showed highest percentage of error occurred, currently DICOM data improved a lot compare to past. Moreover, it should be devoted to rule of IHE TOOL or DICOM. In conclusion, we can help radiographer to analyze information of image by providing clues for solving primary problem and further more, each of PACS company or equipment company can enhance fidelity for following standard of image information through realizing the actual problem during transfer of image information.

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Development and Validation of a Multidimensional Measure of Positive Body Image

  • Lee, Minsun;Lee, Hyun-Hwa
    • Journal of the Korean Society of Clothing and Textiles
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    • v.46 no.4
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    • pp.704-722
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    • 2022
  • Current studies validate the Body Positive Scale (BP Scale) as a self-assessment instrument that captures four dimensions of the positive body image construct. We developed and evaluated a 17-item BP Scale using two focus group interviews and four independent samples (n = 1,379) of Korean women who completed online survey questionnaires. We generated an initial pool of items via literature review, content validation with experts, and focus group interviews, subsequently refining the items through exploratory analysis (Study 1). We confirmed the BP Scale's underlying dimensions with young Korean female samples (Study 2, Study 4) and with a community sample (Study 3). We also examined the construct validity, internal consistency, and test-retest reliability over a six-week interval. Overall, the results supported that the four-factor BP Scale demonstrates adequate validity and reliability in measuring positive body image among Korean women. The BP Scale provides a method for researchers and practitioners to understand and assess individuals' positive body image in a multifaceted manner.

CROSS-VALIDATION OF ARTIFICIAL NEURAL NETWORK FOR LANDSLIDE SUSCEPTIBILITY ANALYSIS: A CASE STUDY OF KOREA

  • LEE SARO;LEE MOUNG-JIN;WON JOONG-SUN
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.298-301
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    • 2004
  • The aim of this study is to cross-validate of spatial probability model, artificial neural network at Boun, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the Boun, Janghung and Youngin areas from interpretation of aerial photographs, field surveys, and maps of the topography, soil type, forest cover and land use were constructed to spatial data-sets. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography, were calculated from the topographic database. Topographic type, texture, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter, age and density of forest were extracted from the forest database. Lithology was extracted from the geological database, and land use was classified from the Landsat TM image satellite image. Landslide susceptibility was analyzed using the landslide­occurrence factors by artificial neural network model. For the validation and cross-validation, the result of the analysis was applied to each study areas. The validation and cross-validate results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations.

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