• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.5
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• pp.333-340
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• 2003

Doppler processing is the heart of pulsed Doppler radar. It gives a clutter elimination and coherent integration. With the improvement of digital signal processors (DPSs), the implementation using them is more widely used in radar systems. Generally, so as for Doppler processor to process the input data in real time, a parallel processing concept using multiple DSPs should be used. This paper implements a programmable Doppler processor, which consists of MTI filter, DFB and square-law detector, using 8 ADSP21060s. Formulating the distribution time of the input data, the transfer time of the output data and the time required to compute each algorithm, it estimates total processing time and the number of required DSP. Finally, using the TSG that provides radar control pulses and simulated target signals, performances of the implemented Doppler processor are evaluated.

• Annals of Clinical Neurophysiology
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• v.9 no.1
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• pp.29-32
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• 2007

Recurrent transverse myelitis is a rare manifestation of systemic lupus erythematosus. Recurrent transverse myelitis presents the biggest diagnostic problem, since it is common manifestation of multiple sclerosis. But it can also be the only feature or first manifestation in systemic lupus erythematosus. Neurological manifestations and magnetic resonance imaging can be indistinguishable, and there are no specific diagnostic tools. Here we describe a 59-year-old female having a systemic lupus erythematosus with recurrent transverse myeltitis. No uniform therapeutic protocol exists for systemic lupus erythematous with transverse myelitis, and the prognosis is usually poor. We suggest that aggressive treatment (usually with pulses of methylprednisolone and cyclophosphamide) might improve the prognosis of systemic lupus erythematosus with transverse myeltis.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.217-231
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• 2003

Coded excitation with complementary Golay sequences is an effective means to increase the SNR and penetration of ultrasound imaging. in which the two complementary binary codes are transmitted successively along each scan-line, reducing the imaging frame rate by half. This method suffers from low frame rate particularly when multiple transmit focusing is employed, since the frame rate will be further reduced in proportion to the number of focal zones. In this paper. a new ultrasound imaging technique based on simultaneous multiple transmit focusing using modified orthogonal Golay codes is proposed to improve lateral resolution with no accompanying decrease in the imaging frame rate, in which a pair of orthogonal Golay codes focused at two different focal depths are transmitted simultaneously. On receive, these modified orthogonal Golay codes are separately compressed into two short pulses and individually focused. These two focused beams are combined to form a frame of image with improved lateral resolution. The Golay codes were modified to improve the transmit power efficiency (TPE) for practical imaging. Computer simulations and experimental results show that the proposed method improves significantly the lateral resolution and penetration of ultrasound imaging compared with the conventional method.

• The Journal of the Acoustical Society of Korea
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• v.39 no.6
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• pp.533-540
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• 2020

A total length of sperm whales can be estimated by measuring the Inter-Pulse Interval(IPI) of their clicks composed by multiple pulses. The IPI is caused by the two-way travel time of the sound transmission in the spermaceti within the whale head. Therefore, the IPI can be used to measure the whale's total length based on allometric relationships between head and body length. In this paper, the click signals recorded in the East Sea, Korea in 2017 were analyzed to estimate the size of sperm whales. The size of sperm whales calculated by the relationship between IPI and body length was 9.9 m to 10.9 m, which is corresponding to the size of an adult female or a juvenile male sperm whale. This non-lethal acoustic method has been demonstrated to accurately estimate the sperm whale size, and can provide useful information for domestic sperm whale monitoring.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.552-558
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• 2014

In this paper, we propose a side-peak cancellation technique of composite binary offset carrier (CBOC) signals for e-navigation. First, we divide a CBOC sub-carrier into several sub-carrier pulses, and then, observe that CBOC autocorrelation is the sum of multiple sub-correlation functions. Finally, we propose a novel correlation function with no side-peak and a sharp main-peak by combining the sub-correlation functions to improve the positioning accuracy. From numerical results, we confirm that the proposed correlation function with a sharp main-peak provides a better positioning performance than the conventional correlation functions in terms of the tracking error standard deviation.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.49-56
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• 1972

This experiment was designed to explore specific functional relationship between the vestibular canals and the extraocular oblique muscles by observing the isometric tension responeses of the muscles to the selected vestibular canal excitation. The vestibular excitation was simulated by either stimulation of the individual canal nerve or endolymphatic fluid displacement in each canal. Each canal nerve was subjected to square wave pulses with a monopolar wire electrode placed closely to the ampullary nerve endings for electrical stimulation, and a fine stainless cannula was introduced into the each canal toward the ampulla and a minute amount $(0.5{\sim}3.5\;microliter)$ of fluid was injected in or ejected out by means of a microsyringe connected to the cannula to produce ampullopetal or ampullofugal displacement of endolymphatic fluid. The superior oblique muscle was contracted by the excitation of homolateral canals and was relaxed by contralateral canals. On the contrary, the inferior oblique was contracted by the contralateral canals and was relaxed by the homolateral canals. Summation of excitatory and inhibitory canal effects from the bilateral vestibular system was demonstrable on the tension changes of the oblique muscles. Excitation of either dual or triple canals of the unilateral vestibular system also caused summation effect on the tension response of the oblique pair; thus multiple signals from the different ampullary receptors seems to be converged into the relevant ocular motor muclei. Since the superior and inferior obliques are known to receive their motor fibers from the contralateral trochlear nuclei and intermediate nuclei of the homolateral oculomotor complex respectively, the above experimental evidences indicate that the ocular motor nuclei for oblique muscles receive excitatory signals from the contralateral vestibular canals and inhibitory signals from the homolateral canals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1433-1440
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• 2015

In this paper, we propose an unambiguous correlation function to improve tracking performance for binary offset carrier (BOC) signals. Specifically, we divide a BOC sub-carrier into multiple rectangular pulses, and analyze that the BOC autocorrelation function is made up of the sum of several partial correlation functions. Then, we obtain two sub-correlation functions by combining two partial correlation functions and propose a novel unambiguous correlation function with no side-peak which can be regulated its width based on the combination of the sub-correlation functions and partial correlation functions. From numerical results, it is confirmed that the proposed correlation function provides a tracking performance improvement over the conventional correlation functions in terms of the tracking error standard deviation.

• Korean Journal of Materials Research
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• v.23 no.10
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• pp.550-554
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• 2013

As continued scaling becomes increasingly difficult, 3D integration has emerged as a viable solution to achieve higher bandwidths and good power efficiency. 3D integration can be defined as a technology involving the stacking of multiple processed wafers containing integrated circuits on top of each other with vertical interconnects between the wafers. This type of 3D structure can improve performance levels, enable the integration of devices with incompatible process flows, and reduce form factors. Through silicon vias (TSVs), which directly connect stacked structures die-to-die, are an enabling technology for future 3D integrated systems. TSVs filled with copper using an electro-plating method are investigated in this study. DC and pulses are used as a current source for the electro-plating process as a means of via filling. A TiN barrier and Ru seed layers are deposited by plasma-enhanced atomic layer deposition (PEALD) with thicknesses of 10 and 30 nm, respectively. All samples electroplated by the DC current showed defects, even with additives. However, the samples electroplated by the pulse current showed defect-free super-filled via structures. The optimized condition for defect-free bottom-up super-filling was established by adjusting the additive concentrations in the basic plating solution of copper sulfate. The optimized concentrations of JGB and SPS were found to be 10 and 20 ppm, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.3
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• pp.264-272
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• 2009

In this paper, a Ka-band 10 W power amplifier module is designed and fabricated using MIC(Microwave Integrated Circuit) module technology which combines multiple power MMIC(Monolithic Microwave Integrated Circuit) chips on a thin film substrate. Modified Wilkinson power dividers/combiners are used for millimeter wave modules and CBFGC-PW-Microstrip transitions are utilized for reducing connection loss and suppressing resonance in the high-gain and high-power modules. The power amplifier module consists of seven MMIC chips and operates in a pulsed mode. for the pulsed mode operation, a gate pulse control circuit supplying the control voltage pulses to MMIC chips is designed and applied. The fabricated power amplifier module shows a power gain of about 58 dB and a saturated output power of 39.6 dBm at a center frequency of the interested frequency band.

• Medical Lasers
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• v.9 no.2
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• pp.159-165
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• 2020

Background and Objectives The ultimate goal in current skin rejuvenation practice is to achieve a good result with minimal pain and downtime. Nonablative skin rejuvenation (NSR) is one technique. The efficacy of the long-pulsed 1064 nm Nd:YAG laser (LPNDY) has not been assessed in NSR. Materials and Methods Three target areas were selected (bilateral cheeks and glabellar region) in six volunteer subjects. A LPNDY with an integral skin temperature monitor delivered three stacked shots to each target area (1064 nm, 12 mm spot, 13 J/cm², 1 Hz) without any skin cooling or anesthesia. The skin temperature was recorded before, during, and after each set of shots using the system monitor and in real-time using a high-sensitivity (±0.001℃) near-infrared video camera. The skin reaction was observed with the naked eye, and pain and discomfort were assessed by the subjects during and after treatment. Results The subjects reported a mild feeling of heat with no discomfort during or after the test treatments. Mild erythema was observed around the treatment areas, without noticeable edema. A series of three ascending skin temperature stepwise peaks, with a decrease in skin temperature towards the baseline after the third shot, was observed consistently. The mean temperatures for shots 1, 2, and 3 for the cheeks were 39.5℃, 42.0℃, and 44.4℃, respectively, and for the glabella, 40.8℃, 43.9℃, and 46.2℃, respectively. Similar ranges were indicated on the system integral temperature monitor. Conclusion A set of three stacked pulses with the LPNDY at a low fluence achieved ideal dermal temperatures to achieve some dermal remodeling but without any downtime or adverse events. The temperature data from the integral thermal sensor matched the video camera measurements with practical accuracy for skin rejuvenation requirements. These data suggest that LPNDY would satisfy the necessary criteria to achieve effective NSR, but further studies will be needed to assess the actual results in clinical practice.