• Proceedings of the KSMRM Conference
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• 2004.09a
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• pp.44-44
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• 2004

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.594-596
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• 1991

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1075-1078
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• 2008

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.123-125
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• 2003

Satellite IKONOS images are one of important remote sensing data sources as today because of their very high spatial resolution. Their detections for islands and offshore oceanic features with multi-dimension and multi-scales information, specially some small islands, are of great potential. Their application abilities in islands and offshore detections are addressed at the first of the paper. And image processing technologies and the information extracting methodologies are described. Some results on remote sensing of the islands and their nearby object features are shown in details. Discussions and conclusions are carried out simply at the final.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.25-31
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• 2009

The recently developed sampling theory, "compressed sensing" is gathering huge interest in MR reconstruction area because of its feasibility of high spatio-temporal resolution of dynamic MRI which has been limited in conventional methods based on Nyquist sampling theory. Since dynamic MRI usually has high redundant information along temporal direction, this can be very sparsely represented in most of cases. Therefore, compressed sensing that exploits the sparsity of unknown images can be effectively applied in most of dynamic MRI. This review article briefly introduces currently proposed compressed sensing based dynamic MR imaging algorithms and other methods exploiting sparsity. By comparing them with conventional methods, you may have insight how the compressed sensing based methods can impact nearly every area of clinical dynamic MRI.

• Tunnel and Underground Space
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• v.19 no.6
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• pp.545-557
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• 2009

In order to investigate dynamic damage mechanism of brittle materials, Split Hopkinson Pressure Bar (SHPB) have been adapted to apply different impact levels to rocks in South Korea. High resolution X-ray Computed Tomography (CT) was used to estimate the damage in tested rock samples nondestructively. The cracks which are parallel to the loading axis are visible on the contact surface with the incident bar under lower level of impact. The surface cracks disappeared with increment of impact level due to confined effect between the incident bar and sample, while axial splitting are happened near the outer surface.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.515-522
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• 2005

Enzyme-metal combo catalysis is described as a useful methodology for the synthesis of optically active compounds. The key point of the method is the use of enzyme and metal in combination as the catalysts for the complete transformation of racemic substrates to single enantiomeric products through dynamic kinetic resolution (DKR). In this approach, enzyme acts as an enantioselective resolving catalyst and metal does as a racemizing catalyst for the efficient DKR. Three kinds of enzyme-metal combinations - lipase-ruthenium, subtilisin-ruthenium, and lipase-palladium –have been developed as the catalysts for the DKRs of racemic alcohols, esters, and amines. The scope of the combination catalysts can be extended to the asymmetric transformations of ketones, enol acetates, and ketoximes via the DKRs. In most cases studied, enzyme-metal combo catalysis provided enantiomerically-enriched products in high yields.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.1
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• pp.15-24
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• 2012

In this paper, we suggest the dynamic-response-free SMPS using a new high-resolution DPWM generator based on switched-capacitor delay technique. In the proposed system, duty ratio of DPWM is controlled by voltage slope of an internal capacitor using switched-capacitor delay technique. In the proposed circuit, it is possible to track output voltage by controlling current of the internal capacitor of the DPWM generator through comparison between the feedback voltage and the reference voltage. Therefore the proposed circuit is not restricted by the dynamic-response characteristic which is a problem in the existing SMPS using the closed-loop control method. In addition, it has great advantage that ringing phenomenon due to overshoot/undershoot does not appear on output voltage. The proposed circuit can operate at switching frequencies of 1MHz~10MHz using internal operating frequency of 100 MHz. The maximum current of the core circuit is 2.7 mA and the total current of the entire circuit including output buffer is 15 mA at the switching frequency of 10 MHz. The proposed circuit has DPWM duty ratio resolution of 0.125 %. It can accommodate load current up to 1 A. The maximum ripple of output voltage is 8 mV. To verify operation of the proposed circuit, we carried out simulation with Dongbu Hitek BCD $0.35{\mu}m$ technology parameter.

• Journal of IKEEE
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• v.22 no.4
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• pp.901-906
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• 2018

Due to the development of display technologies for images, the resolution and quality of images are increasing day by day. In accordance with the development of the display technology, researches have been actively conducted on technologies for converting and displaying existing images to higher resolution and quality. Since the results of theses studies are included in the image signal processor, hardware implementation is indispensable. In this paper, we propose a real-time HDR(High Dynamic Range) conversion hardware implementation of LDR(Low Dynamic Range) image using luminance distribution. The proposed method extracts the features of the image using the histogram of the luminance distribution, and extends the luminance and color based on the extracted features. In addition, when the proposed method is designed by hardware IP(Intellectual Property) and its performance is verified, 4K DCI(Digital Cinema Image) can be handled at a rate of 30fps at 265.46MHz.

• Journal of Biomedical Engineering Research
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• v.26 no.1
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• pp.31-35
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• 2005

A novel synthetic aperture method for real-time three-way dynamic focusing is proposed, which provides lateral beam patterns represented as the product of Fourier transforms of transmit subaperture, receive subaperture, and a synthetic window function. In the proposed method, all array elements are fired individually and for each firing echo signals are recorded from all elements of a receive subaperture moving along an array with the transmit element. The three-way dynamic focusing is then achieved by employing a synthetic aperture algorithm for two-way dynamic focusing and a synthetic focusing method for transmit dynamic focusing. Both theoretical analysis and computer simulation results show that the proposed method produces ultrasound beams with improved lateral resolution at all depths compared to the conventional phased array imaging and synthetic aperture focusing methods.