• Title/Summary/Keyword: distortions

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Study on Modernized Real Estate Transaction System based on Spatial Information (공간정보기반 부동산거래선진화시스템 구축방안)

  • Cho, Chun Man;Chung, Moon Sub
    • Spatial Information Research
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    • v.21 no.6
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    • pp.69-80
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    • 2013
  • Our country has made every efforts to develop Real Estate Transaction culture with emphasis on Licensed Realtors by introducing Real Estate Transaction Law in 1983. Also, MOLIT(Ministry of Land, Infrastructure and Transport) designated several organizations including KAR(Korea Association of Realtors) as Real Estate Transaction Information Network Licensees for data credibility enhancement and transaction transparency. Nevertheless, the level of law abiding spirit and transaction culture are still similar to those of the old 'Bokdeokbang' era. The under-developed transaction behaviors prevent the social capital of people's credibility on Licensed Realtors from advancing, and results in the outcomes of unnecessary social cost. That is, very low credibility on the data on Sales Items in the market and the fear of speculative real estate price uprise and market distortions are continuing on. In this context, the purpose of this study is to propose the model of GIS-based Modernized Real Estate Transaction System and its execution policies to support credible Real Estate Information to the general public for efficient transactions in the market. Accordingly, the study aims at contributing to the modernization of Real Estate Transactions, fostering competitiveness of Realtors in the Real Estate Market.

Research for Calibration and Correction of Multi-Spectral Aerial Photographing System(PKNU 3) (다중분광 항공촬영 시스템(PKNU 3) 검정 및 보정에 관한 연구)

  • Lee, Eun Kyung;Choi, Chul Uong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.4
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    • pp.143-154
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    • 2004
  • The researchers, who seek geological and environmental information, depend on the remote sensing and aerial photographic datum from various commercial satellites and aircraft. However, the adverse weather conditions and the expensive equipment can restrict that the researcher can collect their data anywhere and any time. To allow for better flexibility, we have developed a compact, a multi-spectral automatic Aerial photographic system(PKNU 2). This system's Multi-spectral camera can catch the visible(RGB) and infrared(NIR) bands($3032{\times}2008$ pixels) image. Visible and infrared bands images were obtained from each camera respectively and produced Color-infrared composite images to be analyzed in the purpose of the environment monitor but that was not very good data. Moreover, it has a demerit that the stereoscopic overlap area is not satisfied with 60% due to the 12s storage time of each data, while it was possible that PKNU 2 system photographed photos of great capacity. Therefore, we have been developing the advanced PKNU 2(PKNU 3) that consists of color-infrared spectral camera can photograph the visible and near infrared bands data using one sensor at once, thermal infrared camera, two of 40 G computers to store images, and MPEG board to compress and transfer data to the computer at the real time and can attach and detach itself to a helicopter. Verification and calibration of each sensor(REDLAKE MS 4000, Raytheon IRPro) were conducted before we took the aerial photographs for obtaining more valuable data. Corrections for the spectral characteristics and radial lens distortions of sensor were carried out.

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High Bit-Rates Quantization of the First-Order Markov Process Based on a Codebook-Constrained Sample-Adaptive Product Quantizers (부호책 제한을 가지는 표본 적응 프로덕트 양자기를 이용한 1차 마르코프 과정의 고 전송률 양자화)

  • Kim, Dong-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.1
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    • pp.19-30
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    • 2012
  • For digital data compression, the quantization is the main part of the lossy source coding. In order to improve the performance of quantization, the vector quantizer(VQ) can be employed. The encoding complexity, however, exponentially increases as the vector dimension or bit rate gets large. Much research has been conducted to alleviate such problems of VQ. Especially for high bit rates, a constrained VQ, which is called the sample-adaptive product quantizer(SAPQ), has been proposed for reducing the hugh encoding complexity of regular VQs. SAPQ has very similar structure as to the product VQ(PQ). However, the quantizer performance can be better than the PQ case. Further, the encoding complexity and the memory requirement for the codebooks are lower than the regular full-search VQ case. Among SAPQs, 1-SAPQ has a simple quantizer structure, where each product codebook is symmetric with respect to the diagonal line in the underlying vector space. It is known that 1-SAPQ shows a good performance for i.i.d. sources. In this paper, a study on designing 1-SAPQ for the first-order Markov process. For an efficient design of 1-SAPQ, an algorithm for the initial codebook is proposed, and through the numerical analysis it is shown that 1-SAPQ shows better quantizer distortion than the VQ case, of which encoding complexity is similar to that of 1-SAPQ, and shows distortions, which are close to that of the DPCM(differential pulse coded modulation) scheme with the Lloyd-Max quantizer.

Image Distortion Compensation for Improved Gait Recognition (보행 인식 시스템 성능 개선을 위한 영상 왜곡 보정 기법)

  • Jeon, Ji-Hye;Kim, Dae-Hee;Yang, Yoon-Gi;Paik, Joon-Ki;Lee, Chang-Su
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.97-107
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    • 2009
  • In image-based gait recognition systems, physical factors, such as the camera angle and the lens distortion, and environmental factors such as illumination determines the performance of recognition. In this paper we present a robust gait recognition method by compensating various types of image distortions. The proposed method is compared with existing gait recognition algorithm with consideration of both physical and environmental distortion factors in the input image. More specifically, we first present an efficient compensation algorithm of image distortion by using the projective transform, and test the feasibility of the proposed algorithm by comparing the recognition performances with and without the compensation process. Proposed method gives universal gait data which is invariant to both distance and environment. Gained data improved gait recognition rate about 41.5% in indoor image and about 55.5% in outdoor image. Proposed method can be used effectively in database(DB) construction, searching and tracking of specific objects.

Image Mosaicking Using Feature Points Based on Color-invariant (칼라 불변 기반의 특징점을 이용한 영상 모자이킹)

  • Kwon, Oh-Seol;Lee, Dong-Chang;Lee, Cheol-Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.2
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    • pp.89-98
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    • 2009
  • In the field of computer vision, image mosaicking is a common method for effectively increasing restricted the field of view of a camera by combining a set of separate images into a single seamless image. Image mosaicking based on feature points has recently been a focus of research because of simple estimation for geometric transformation regardless distortions and differences of intensity generating by motion of a camera in consecutive images. Yet, since most feature-point matching algorithms extract feature points using gray values, identifying corresponding points becomes difficult in the case of changing illumination and images with a similar intensity. Accordingly, to solve these problems, this paper proposes a method of image mosaicking based on feature points using color information of images. Essentially, the digital values acquired from a digital color camera are converted to values of a virtual camera with distinct narrow bands. Values based on the surface reflectance and invariant to the chromaticity of various illuminations are then derived from the virtual camera values and defined as color-invariant values invariant to changing illuminations. The validity of these color-invariant values is verified in a test using a Macbeth Color-Checker under simulated illuminations. The test also compares the proposed method using the color-invariant values with the conventional SIFT algorithm. The accuracy of the matching between the feature points extracted using the proposed method is increased, while image mosaicking using color information is also achieved.

Analysis of Target Identification Performances against the Moving Targets Using a Bistatic Radar (바이스태틱 레이다를 이용한 이동표적에 대한 표적식별 성능 분석)

  • Lee, Seung-Jae;Bae, Ji-Hoon;Jeong, Seong-Jae;Yang, Eunjung;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.2
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    • pp.198-207
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    • 2016
  • Bistatric radar can perform detection and identification for stealth targets that are rarely detected by the conventional monostatic radar. However, high resolution range profile(HRRP) generated from the received signal in the bistatic radar cannot show exact range information of the target because the bistatic geometry lead to the distortions of the bistatic HRRP. In addition, electromagnetic scattering mechanisms of the target are varied depending on the bistatic geometry. Thus, efficient database construction is a crucial factor to achieve successful classification capability in bistatic target identification. In this paper, a database construction method based on realistic flight scenarios of a target, which provides a reliable identification performance for the monostatic radar, is applied to bistatic target identification. Then, the capability and efficiency of the method is analyzed. Simulation results show that reliable identification performance can be achieved using the database construction based on the flight scenarios when the target is a considerable distance away from the bistatic radar.

A Histogram Matching Scheme for Color Pattern Classification (컬러패턴분류를 위한 히스토그램 매칭기법)

  • Park, Young-Min;Yoon, Young-Woo
    • The KIPS Transactions:PartB
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    • v.13B no.7 s.110
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    • pp.689-698
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    • 2006
  • Pattern recognition is the study of how machines can observe the environment, learn to distinguish patterns of interest from their background, and make sound and reasonable decisions about the categories of the patterns. Color image consists of various color patterns. And most pattern recognition methods use the information of color which has been trained and extract the feature of the color. This thesis extracts adaptively specific color feature from images with several limited colors. Because the number of the color patterns is limited, the distribution of the color in the image is similar. But, when there are some noises and distortions in the image, its distribution can be various. Therefore we cannot extract specific color regions in the standard image that is well expressed in special color patterns to extract, and special color regions of the image to test. We suggest new method to reduce the error of recognition by extracting the specific color feature adaptively for images with the low distortion, and six test images with some degree of noises and distortion. We consequently found that proposed method shouws more accurate results than those of statistical pattern recognition.

The Study of Effectiveness of 3 Spot DR for the Whole Spine Radiography with Comparison of Phantom Distortions (3 Spot DR를 이용한 척추 전장 촬영 시 모형 왜곡도 비교를 통한 유용성 연구)

  • Kim, Sang-Hyun;Lee, Mi-Hwa
    • Journal of Digital Convergence
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    • v.12 no.10
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    • pp.345-351
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    • 2014
  • The purpose of this study is to offer more accurate information in whole spine examination of 3 spot DR through the comparative study about image distortion as making the flat phantom and measuring horizontal, vertical ratio and cobb angle of the virtual. We produced $H(40cm){\times}V(116cm){\times}D(2.3cm)$ flat acrylic phantom with lattice type of lead plate. We took projection respectively 3 times, total 9 times in each equipments using manufactured phantom as changing OFD to 6, 12, 18 cm. We measured a horizontal and vertical length of lead lattice and calculated the ratio. As appointing arbitrary points in the phantom and we measured cobb angle. The results of horizontal, vertical ratio measured CR type 0.98~1.01, scan DR type 0.96~0.97 and 3 spot DR 0.99~1.01. Cobb angle measured $52.5{\sim}53.3^{\circ}$, $52.1{\sim}54.3^{\circ}$ and $52.8{\sim}53.2^{\circ}$. Finally we can say that 3 spot DR method is an accurate method without any distortion in whole spine radiography.

Accuracy in target localization in stereotactic radiosurgery using diagnostic machines (정위적 방사선수술시 진단장비를 이용한 종양위치결정의 정확도 평가)

  • 최동락
    • Progress in Medical Physics
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    • v.7 no.1
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    • pp.3-7
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    • 1996
  • The accuracy in target localization of CT, MR, and digital angiography were investigated for stereotactic radiosurgery. The images using CT and MR were obtained out of geometrical phantom which was designed to produce exact coordinates of several points within a 0.lmm error range. The slice interval was 3mm and FOV was 35cm for CT and 28cm for MR. These images were transferred to treatment planning computer using TCP/IP in forms of GE format. Measured 3-D coordinates of these images from planning computer were compared to known values by geometrical phantom. Anterior-posterior and lateral films were taken by digital angiography for measurement of spatial accuracy. Target localization errors were 1.2${\pm}$0.5mm with CT images, 1.7${\pm}$0.4mm with MR-coronal images, and 2.1${\pm}$0.7mm with MR-sagittal images. But, in case of MR-axial images, the target localization error was 4.7${\pm}$0.9mm. Finally, the target localization error of digital angiography was 0.9${\pm}$0.4mm. The accuracy of diagnostic machines such as CT, MR, and angiography depended on their resolutions and distortions. The target localization error mainly depended on the resolution due to slice interval with CT and the image distortion as well as the resolution with MR However, in case of digital angiography, the target localization error was closely related to the distortion of fiducial markers. The results of our study should be considered when PTV (Planning Target Volume) was determined.

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A System for Concurrent TMS-fMRI and Evaluation of Imaging Effects (동시 뇌경두개자기자극-기능자기공명영상 시행을 위한 홀더 제작과 시뮬레이션 및 영상 데이터 평가)

  • Kim, Jae-Chang;Kyeong, Sunghyon;Lee, Jong Doo;Park, Hae-Jeong
    • Investigative Magnetic Resonance Imaging
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    • v.17 no.3
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    • pp.169-180
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    • 2013
  • Purpose : The purpose of this study was to setup a concuurent transcranial magnetic stimulation (TMS)-functional MRI (fMRI) system for understanding causality of the functional brain network. Materials and Methods: We manufactured a TMS coil holder using nonmagnetic polyether ether ketone (PEEK). We simulated magnetic field distributions in the MR scanner according to TMS coil positions and angles. To minimize image distortions caused by TMS application, we controlled fMRI acquisition and TMS sequences to trigger TMS during inter-volume intervals. Results: Simulation showed that the magnetic field below the center of the coil was dramatically decreased with distance. Through the MR phantom study, we confirmed that TMS application around inter-volume acquisition time = 100 miliseconds reduced imaging distortion. Finally, the applicability of the concurrent TMS-fMRI was tested in preliminary studies with a healthy subject conducting a motor task within TMS-fMRI and passive motor movement induced by TMS in fMRI. Conclusion: In this study, we confirmed that the developed system allows use of TMS inside an fMRI system, which would contribute to the research of brain activation changes and causality in brain connectivity.