• Title/Summary/Keyword: imaging performance

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Interference Issuses of Radio Frequency Identification Devices in Magnetic Resonance Imaging Systems and Computed Tomography Scan

  • Periyasamy, M.;Dhanasekaran, R.
    • Journal of Magnetics
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    • v.20 no.3
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    • pp.295-301
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    • 2015
  • We evaluated certain issues related to magnetic resonance imaging (MRI) coupled with the use of active 2.5 GHz radio frequency identification (RFID) tags for patient identification using low field (0.3 T) MRI and computed tomography (CT) scans. We also investigated the performance of the RFID reader located outside the MRI room by considering several factors. A total of ten active RFID tags were exposed to several MRI sequences and X-rays of CT scan. We found that only card type active RFID tags are suitable for patient identification purpose in MRI environment and both wristbands as well as card tags were suitable for the same in CT environment. Severe artifacts were found in the captured MRI and CT images when the area of the imaging was in proximity to the tags. No external factors affected the performance of active RFID reader stationed outside the MRI scan room.

Spaceborne SAR System Design and Performance Characteristics for Military Applications (위성탑재 SAR 시스템 설계와 성능 특징)

  • 곽영길;이범석;이상인;황용철
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.2
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    • pp.101-120
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    • 2000
  • A synthetic aperture radar (SAR) system can provide all-weather, day and night, superior imaging capability, and thus is very useful in surveillance for military applications. In this paper, a X-band spaceborne SAR system design concept is introduced with the key design parameters for mission and system requirements characterized by small satellite system. The SAR imaging mode design procedure is presented, and the standard imaging mode design results are analyzed as an example. In line with the given mission and system requirements, the X-band SAR payload and ground reception/processing subsystems are designed and presented with the key design results. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance system in light-weight, high-performance and cost-effective points of view.

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Two-color Counter-countermeasure for the Crossed Array Tracker

  • Lee, S.H.;Oh, J.S.;Doo, K.S.;Seo, D.S.;Choi, J.S.
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.1059-1062
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    • 2000
  • Infrared (IR) seeker identifies the location of a target by detecting the infrared energy radiated from the target, and enables the missile to track the target. To improve the tracking performance, a counter- countermeasure (CCM) is essential to minimize the effect of the countermeasure (CM), which is operated by a target to protect itself. In this paper, we propose a crossed array tracker (CAT) using two-color CCM algorithm. The CAT using the proposed algorithm shows better tracking performance by minimizing the effect of CM.

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Crosstalk evaluation in multiview autostereoscopic three-dimensional displays with an optimized diaphragm applied

  • Peng, Yi-Fan;Li, Hai-Feng;Zheng, Zhen-Rong;Xia, Xin-Xing;Yao, Zhi;Liu, Xu
    • Journal of Information Display
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    • v.13 no.2
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    • pp.83-89
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    • 2012
  • The crosstalk evaluation of multiview autostereoscopic three-dimensional (3D) displays is discussed, with both the human and technical factors investigated via image quality assessment. In the imaging performance measurements and analysis for a multiview autostereoscopic display prototype equipment, it was inferred that crosstalk would have both a positive and a negative effect on the imaging performance of the equipment. The importance of the attached diaphragm in the crosstalk evaluation was proposed and then experimentally verified, using the developed prototype equipment. The luminance distribution and crosstalk situation were given, with two different diaphragm arrays applied. The analysis results showed that the imaging performance of this 3D display system can be improved with minimum changes to the system structure.

Development of an Earth Observation Optical Payload Simulator

  • Lee, Jong-Hoon;Lee, Jun-Ho;Cheon, Yee-Jin
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.35.1-35.1
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    • 2008
  • The importance on the simulation of earth observation optical payloads has been recently emphasized in order to estimate on-orbit imaging performance of the payloads. The estimation should consider all aspects of payload development; design, manufacture, test, assembly, launch and space environment. Until recently several studies have been focused the evaluation of the individual factors rather than the integrated. This paper presents the development of an integrated payload simulator. The simulator analyzes the payload imaging performance based on MTF(Modulation Transfer Function) calculations of the major factors (Diffraction, Aberration, Detector integration, Image motion and etc.) and the simulator can generate realistic artificial earth images as taken by defined earth observation payloads. The simulator is developed for the use of evaluating pre- and post-launch imaging performance and assisting on-board calibration of COMPSAT-3.

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Investigation of a blind-deconvolution framework after noise reduction using a gamma camera in nuclear medicine imaging

  • Kim, Kyuseok;Lee, Min-Hee;Lee, Youngjin
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2594-2600
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    • 2020
  • A gamma camera system using radionuclide has a functional imaging technique and is frequently used in the field of nuclear medicine. In the gamma camera, it is extremely important to improve the image quality to ensure accurate detection of diseases. In this study, we designed a blind-deconvolution framework after a noise-reduction algorithm based on a non-local mean, which has been shown to outperform conventional methodologies with regard to the gamma camera system. For this purpose, we performed a simulation using the Monte Carlo method and conducted an experiment. The image performance was evaluated by visual assessment and according to the intensity profile, and a quantitative evaluation using a normalized noise-power spectrum was performed on the acquired image and the blind-deconvolution image after noise reduction. The result indicates an improvement in image performance for gamma camera images when our proposed algorithm is used.

An Efficient Ultrasonic SAFT Imaging for Pulse-Echo Immersion Testing

  • Hu, Hongwei;Jeong, Hyunjo
    • Journal of the Korean Society for Nondestructive Testing
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    • v.37 no.2
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    • pp.84-90
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    • 2017
  • An ultrasonic synthetic aperture focusing technique (SAFT) using a root mean square (RMS) velocity model is proposed for pulse-echo immersion testing to improve the computational efficiency. Considering the immersion ultrasonic testing of a steel block as an example, three kinds of imaging were studied (B-Scan, SAFT imaging based on ray tracing technology and RMS velocity). The experimental results show that two kinds of SAFT imaging have almost the same imaging performance, while the efficiency of RMS velocity SAFT imaging is almost 25 times greater than the SAFT based on Snell's law.

Development of Optical Molecular Imaging System for the Acquisition of Bioluminescence Signals from Small Animals (소동물 발광영상 측정을 위한 광학분자영상기기의 개발)

  • Lee, Byeong-Il;Kim, Hyeon-Sik;Jeong, Hye-Jin;Lee, Hyung-Jae;Moon, Seung-Min;Kwon, Seung-Young;Choi, Eun-Seo;Jeong, Shin-Young;Bom, Hee-Seung;Min, Jung-Joon
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.4
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    • pp.344-351
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    • 2009
  • Purpose: Optical imaging is providing great advance and improvement in genetic and molecular imaging of animals and humans. Optical imaging system consists of optical imaging devices, which carry out major function for monitoring, tracing, and imaging in most of molecular in-vivo researches. In bio-luminescent imaging, small animals containing luciferase gene locally irradiate light, and emitted photons transmitted through skin of the small animals are imaged by using a high sensitive charged coupled device (CCD) camera. In this paper, we introduced optical imaging system for the image acquisition of bio-luminescent signals emitted from small animals. Materials and Methods: In the system, Nikon lens and four LED light sources were mounted at the inside of a dark box. A cooled CCD camera equipped with a control module was used. Results: We tested the performance of the optical imaging system using effendorf tube and light emitting bacteria which injected intravenously into CT26 tumor bearing nude mouse. The performance of implemented optical imaging system for bio-luminescence imaging was demonstrated and the feasibility of the system in small animal imaging application was proved. Conclusion: We anticipate this system could be a useful tool for the molecular imaging of small animals adaptable for various experimental conditions in future.

Analyzing performance of time series classification using STFT and time series imaging algorithms

  • Sung-Kyu Hong;Sang-Chul Kim
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.4
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    • pp.1-11
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    • 2023
  • In this paper, instead of using recurrent neural network, we compare a classification performance of time series imaging algorithms using convolution neural network. There are traditional algorithms that imaging time series data (e.g. GAF(Gramian Angular Field), MTF(Markov Transition Field), RP(Recurrence Plot)) in TSC(Time Series Classification) community. Furthermore, we compare STFT(Short Time Fourier Transform) algorithm that can acquire spectrogram that visualize feature of voice data. We experiment CNN's performance by adjusting hyper parameters of imaging algorithms. When evaluate with GunPoint dataset in UCR archive, STFT(Short-Time Fourier transform) has higher accuracy than other algorithms. GAF has 98~99% accuracy either, but there is a disadvantage that size of image is massive.

Development of a High-Performance Vehicle Imaging Information System for an Efficient Vehicle Imaging Stabilization (효율적인 차량 영상 안정화를 위한 고성능 차량 영상 정보 시스템 개발)

  • Hong, Sung-Il;Lin, Chi-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.6
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    • pp.78-86
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    • 2013
  • In this paper, we propose design of a high-performance vehicle imaging information system for an efficient vehicle imaging stabilization. The proposed system was designed the algorithm by divided as motion estimation and motion compensation. The motion estimation were configured as local motion vector estimation and irregular local motion vector detection, global motion vector estimation. The motion compensation was corrected for the four directions for compensate to the shake of vehicle video image using estimate GMV. The designed algorithm were designed the motion compensation technology chip by applied to IP for vehicle imaging stabilization. In this paper, the experimental results of the proposed vehicle imaging information system were proved to the effectiveness by compared with other methods, because imaging stabilization of moving vehicle was not used of memory by processing real-time. Also, it could be obtained to reduction effect of calculation time by arithmetic operation through to block matching.