• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.2
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• pp.55-65
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• 2004

In this paper, An efficient non-scan DFT method for datapaths described in RTL is proposed. The proposed non-scan DFT method improves testability of datapaths based on hierarchical testability analysis regardless to width of the datapath. It always guarantees higher fault efficiency and faster test pattern generation time with little hardware overhead than previous methods. The experimental result shows the superiority of the proposed method of test pattern generation time, application time, and area overhead compared to the scan method.

• Journal of Internet Computing and Services
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• v.4 no.3
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• pp.31-37
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• 2003

In this paper, an efficient non-scan design-for-testability (DFT) method for finite state machine(FSM) is proposed. The proposed method always guarantees short test pattern generation time and complete fault efficiency. It has a lower area overhead than full-scan and other non-scan DFT methods and enables to apply test patterns at-speed. The efficiency of the proposed method is demonstrated using well-known MCNC'91 FSM benchmark circuits.

• Smart Structures and Systems
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• v.22 no.2
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• pp.223-230
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• 2018

This study examines a non-contact laser scanning-based ultrasound system, called an angular scan pulse-echo ultrasonic propagation imager (A-PE-UPI), that uses coincided laser beams for ultrasonic sensing and generation. A laser Doppler vibrometer is used for sensing, while a diode pumped solid state (DPSS) Q-switched laser is used for generation of thermoelastic waves. A high-speed raster scanning of up to 10-kHz is achieved using a galvano-motorized mirror scanner that allows for coincided sensing and for the generation beam to perform two-dimensional scanning without causing any harm to the surface under inspection. This process allows for the visualization of longitudinal wave propagation through-the-thickness. A pulse-echo ultrasonic wave propagation imaging algorithm (PE-UWPI) is used for on-the-fly damage visualization of the structure. The presented system is very effective for high-speed, localized, non-contact, and non-destructive inspection of aerospace structures. The system is tested on an aluminum honeycomb sandwich with disbonds and a carbon fiber-reinforced plastic (CFRP) honeycomb sandwich with a layer overlap. Inspection is performed at a 10-kHz scanning speed that takes 16 seconds to scan a $100{\times}100mm^2$ area with a scan interval of 0.25 mm. Finally, a comparison is presented between angular-scanning and a linear-scanning-based pulse-echo UPI system. The results show that the proposed system can successfully visualize defects in the inspected specimens.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.2
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• pp.101-107
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• 2022

In this article, we propose a new protocol at fast scan mode for a sea-surface small target detection. The conventional fast scan mode is composed of coherent intrascan integration to suppress sea clutter and non-coherent interscan integration to exclude sea spikes. The proposed method realizes the coherent interscan integration by the new Fourier relationship between carrier-frequency and initial-radial-range, which can be analytically derived by using multiple carrier frequencies at fast scan mode, leading to improved detection performance, compared to the conventional non-coherent methods. In simulations, our proposed method is verified.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.20-23
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• 2016

Purpose Because of heart movement, PET image of heart is very blur. So, PET scan gated with ECG is necessary to improve a spatial resolution of heart PET image. In this study, we will evaluate a image quality of both gated $^{13}N-ammonia$ PET scan and non-gated one. Materials and Methods Before start a heart PET, we attached a ECG electrode on patients (n = 5, $aged=54{\pm}17$). And we started a list mode PET scan that used by a mCT40 PET/CT (siemens, germany) during 10 minute, injected $^{13}N-ammonia$ ($378{\pm}50MBq$) to a patients at same time. By using this list mode data, we reconstructed both gated PET image and non-gated PET image. Then we analysed a profiles of those images, performed a blind test, and subtracted a gated image on non-gated image. Results FWHM of a gated image is improved about 23% and there is a differency count distribution at a subtracted image from non-gated image to a gated image. But in case of blind test, everybody select the gated image as a better quality among each images. Conclusion As a result, we can find that image quality will improve by using gated PET scan. In additional, we can calculate a EF valve, apply QGS, QPS of PET. Therefore, the gated PET scan help improving an accuracy, applying a more information for a diagnosis.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.4-6
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• 2023

Technetium-labeled phosphate bone scan was shown to detect bone fractures and bone metastasis in early stage than general radiographs. Therefore, bone scan has become one of the most frequently performed nuclear medicine imaging examination. However, non-osseous radiopharmaceutical uptake on the bone scan are unusual findings. We report a case of diffuse splenic absorption of Tc-99m dicarboxypropane diphosphonate in patients who undergo liver transplantation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.11
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• pp.54-61
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• 2003

In this paper, an efficient non-scan design-for-testability (DFT) method for controller circuits is proposed. The proposed method always guarantees a short test pattern generation time and complete fault efficiency. It has a lower area overhead than full-scan and other non-scan DFT methods and enables to apply test patterns at-speed. The proposed method also shortens the test application time through a test pattern re-ordering procedure. The efficiency of the proposed method is demonstrated using well known MCNC'91 FSM benchmark circuits.

• The Journal of the Acoustical Society of Korea
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• v.37 no.1
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• pp.73-81
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• 2018

The quality of side scan sonar images is determined by the frequency of a sonar. A side scan sonar with a low frequency creates low-quality images. One of the factors that lead to low quality is a high-level noise. The noise is occurred by the underwater environment such as equipment noise, signal interference and so on. In addition, in order to compensate for the transmission loss of sonar signals, the received signal is recovered by TVG (Time-Varied Gain), and consequently the side scan sonar images contain non-homogeneous noise which is opposite to optic images whose noise is assumed as homogeneous noise. In this paper, the SSCS (Structural Sparsity based Compressive Sensing) is proposed for removing non-homogeneous noise. The algorithm incorporates both local and non-local models in a structural feature domain so that it guarantees the sparsity and enhances the property of non-local self-similarity. Moreover, the non-local model is corrected in consideration of non-homogeneity of noises. Various experimental results show that the proposed algorithm is superior to existing method.

• The Korean Journal of Nuclear Medicine
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• v.36 no.3
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• pp.147-154
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• 2002

The role of PET in the diagnosis and management of thyroid cancer is discussed. The major role of F-18 FDG PET is on patients with discordant negative I-131 scan and a positive serum thyroglobulin values. F-18 FDG PET scan localized metastatic sites in I-131 scan-negative thyroid carcinoma patients with high accuracy. F-18 PET is also valuable in medullary thyroid cancer with high calcitonin level. Focal thyroid uptake in patients with non-thyroidal diseas has high likelihood of thyroid cancer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.520-524
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• 2002

Multi-reference, scan-based Acoustical Holography is a useful measurement technique when insufficient microphones are available to measure a complete hologram at once. When the sound sources are stationary, the whole hologram can be constructed by joining together sub-holograms captured using a relatively small scan array. Here that approach is extended by the development of a formulation that explicitly includes the acoustical transfer functions between the reference microphones and the scanning microphones. Based on those expressions, a compensation procedure of spectral variance due to source-non-stationarity is proposed. It has been verified both numerically and experimentally that this procedure can help suppress spatially distributed noise caused by the source level non-stationarity that is always present in a measurement.