• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.16.1-164
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• 1998

This paper describes Facial Expression Explorer to search for the components of a facial expression and to map the expression to other expressionless figures like a robot, frog, teapot, rabbit and others. In general, it is a time-consuming and laborious job to create a facial expression manually, especially when the facial expression must personify a well-known public figure or an actor. In order to extract a blending ratio from facial images automatically, the Facial Expression Explorer uses Networked Genetic Algorithm(NGA) which is a fast method for the convergence by GA. The blending ratio is often used to create facial expressions through shape blending methods by animators. With the Facial Expression Explorer a realistic facial expression can be modeled more efficiently.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.825-836
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• 2016

In this paper, a speed-up technique for the non-local means (NLM) image denoising method based on local binary descriptor (LBD) is proposed. In the NLM, most of the computation time is spent on searching for non-local similar patches in the search window. The local binary descriptor which represents the structure of patch as binary strings is employed to speed up the search process in the NLM. The descriptor allows for a fast and accurate preselection of non-local similar patches by bitwise operations. Using this approach, a tradeoff between time-saving and noise removal can be obtained. Simulations exhibit that despite being principally constructed for speed, the proposed algorithm outperforms in terms of denoising quality as well. Furthermore, a parallel implementation on GPU brings NLM-LBD to real-time image denoising.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.601-603
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• 1998

In this paper, Hadamard transform imaging spectrometers utilizing Grill spectrometers are proposed. General Hadamard Transform Spectrometers (HTS) carry out one-encoding through input masks, but Grill spectrometers carry out double-encoding through entrance and exit masks. Thus Grill spectrometers increase the signal-to-noise ratio by double-encoding. we reconfigure the system by using the Grill spectrometers which use a left cyclic S-matrix instead of the conventional right cyclic one. Then, we model the system and apply the mask characteristics method, i.e. $T^{I}$ method, to complete fast algorithm. Through computer simulations, we want to prove the superiority of the proposed system by comparing with the conventional HTS. From Observations concerning the average mean square error(AMSE) associated with estimates from the $T^{I}$ spectrum-recovery method, the relative performances of the two systems are compared.

• Journal of the Optical Society of Korea
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• v.8 no.3
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• pp.115-121
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• 2004

In this paper, we propose a new algorithm to generate elemental images in a computer generated integral imaging system. By comparing the computing time of this algorithm with that of the existing algorithm, we prove the efficiency of this algorithm. Two more algorithms considering the finite size of each pixel are also proposed. These algorithms enhance the quality of the integrated image while generating the elemental image as fast as the existing algorithm.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.42-44
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• 1995

The original DANTE sequence and its variations have limitation in excitation profile (a sinc function-like excitation) due to the finite duration of the DANTE pulsetrain. This sinc function-like selection profile excites only a small fraction of the spins in the pixel thereby results in poor signal to noise ratio (only about ${\sim}1%$ of normal MR imaging sequence). Therefore, this poor signal to noise ratio (SNR) has been the main drawback of the original DANTE sequence. To improve the signal to noise ratio, phases of individual RF pulses in the DANTE pulse train were modulated so that more spins in the object were excited ($1{\sim}3$). We have introduced a new FM (Frequency Modulation) DANTE sequence and analyzed the signal intensity and excitation profiles.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.3
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• pp.140-147
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• 2013

We present a vaguelette-curvelet decomposition based image deblurring algorithm. We first perform denoising based on the hard-thresholding rule by estimating unknown curvelet coefficients. The proposed algorithm then calculates vaguelette functions by deconvolving the curvelet bases by the point spread function. Vaguelette transform is finally performed to make a clearly restored image. Since the proposed algorithm uses the curvelet transform to sensitively express the edges in all directions, it is possible to restore images with more naturally preserved edges in all directions.

• Journal of Magnetics
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• v.21 no.2
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• pp.281-285
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• 2016

The purpose of study was to evaluate SNR and CNR with different contrast agent contents (1.0 mmol/mL gadobutrol and 0.5 mmol/mL gadoterate meglumine) for spin echo (SE) and 3-dimension contrast-enhanced fast field echo (3D CE-FFE) pulse sequences. In this study, we compared the SNR and the CNR between 0.5 mmol/mL gadoterate meglumine and 1.0 mmol/mL gadobutrol according to the concentration of contrast agent in brain MRI. When we compared between SE and 3D CE-FFE pulse sequences, the higher SNR and CNR using 3D CE-FFE pulse sequence can be acquire regardless of contrast agent contents. Also, a statistically significant difference was found for SNR and CNR between all protocols. In conclusion, our results demonstrated that the SNR and CNR have not risen proportionately with contrast agent contents. We hope that these results presented in this paper will contribute to decide contrast agent contents for brain MRI.

• Current Optics and Photonics
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• v.2 no.6
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• pp.595-605
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• 2018

The two-photon process of microscopy provides good spatial resolution and optical sectioning ability when observing quasi-static endogenous fluorescent tissue within an in vivo animal model skin. In order to extend the use of such systems, we developed a two-photon laser scanning microscopy system capable of also capturing $512{\times}512$ pixel images at 90 frames per second. This was made possible by incorporating a 72 facet polygon mirror which was mounted on a 55 kRPM motor to enhance the fast-scan axis speed in the horizontal direction. Using the enhanced temporal resolution of our high-speed two-photon laser scanning microscope, we show that rapid processes, such as fluorescently labeled erythrocytes moving in mouse blood flow at up to 1.2 mm/s, can be achieved.

• Clinical Pain
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• v.20 no.2
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• pp.86-92
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• 2021

Ultrasound imaging in clinical practice is one of the widely used diagnostic methods because there is no radiation risk, more cost- effective compared to MRI or CT, and possible to perform an intervention through fast real-time imaging. In order to increase the diagnostic value, the studies of contrast-enhanced ultrasound (CEUS) using an ultrasound contrast agent have been actively conducted since about 50 years ago and are being used clinically in vascularity and microcirculation of internal organs. Although ultrasound is actively used for the diagnosis and treatment of various diseases in musculoskeletal disorders, there are some limitations in diagnosing mild or small lesions, inflammatory reactions, or abnormalities at the molecular level. In this review, the principles, types, and research, and clinical applications of ultrasound contrast agents have been summarized and introduced. If we understand the characteristics of the ultrasound contrast agents and anatomical knowledge, as well as molecular changes, the ultrasound contrast agents are widely applied in musculoskeletal disorders and have tremendous potential for diagnosis and treatment.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.2
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• pp.1-7
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• 2008

In this paper, we have designed a millimeter-wave passive imaging sensor that is able to use remote sensing and security applications. The brightness temperature distribution of a scene is measured with a antenna at an angular resolution of $3^{\circ}$. The sensor is controlled by a PC, achieving a fast performance by using a pan/tilter. The pan/tilter should be able to scan a 2-D image of the scene, with a linear raster scan pattern. The mechanical scans in azimuth and elevation whereby an image of $20{\times}20$ pixels is acquired within less than 400s. Raw images are immediately displayed and stored for postprocessing.