• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.34-43
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• 2008

An OpenLDI receiver circuit for flat-panel display systems was designed and fabricated using $1.8-{\mu}m$ high-voltage CMOS technology. Designed circuit roughly consists of DLL circuit and parallelizers, which recovers clock and parallelize data bits, respectably. It has one clock input and four data inputs. Measurement results showed that it successfully recovers clock signal from input whose frequency is $10Mhz{\sim}65Mhz$, which corresponds data rate of $70Mbps{\sim}455Mbps$ per channel, or $280Mbps{\sim}1.82Gbps$ when all of the four data channels were utilized. A commercial LCD monitor was modified into a test-bench and used for video data transmission at clock frequency of 49Mhz. In the experiment, power consumption was 19mW for core block and 82.5mW for output buffer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.399-407
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• 2010

SC-FDMA system uses DFT-spreading method for reducing the PAPR of OFDM signal, which improves the power efficiency. Block type pilot is used in SC-FDMA system. However, there are ICI due to the inevitable phase noise and frequency offset that can be generated from the Doppler frequency and inaccuracy between the transceiver oscillators. This ICI definitely degrades the BER performance. To overcome this problem and estimate the channel efficiently, we like to propose ICI compensation algorithm for the SC-FDMA system with comb type pilot. SLM method is additionally included for the PAPR reduction when pilot is assigned in comb type. Finally, it is confirmed that the ICI due to the phase noise and frequency offset is efficiently compensated by the suggested algorithm.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5017-5021
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• 2013

Objective: MicroRNAs (miRNAs) are a small class of non-coding, single-stranded RNAs with a critical role in genesis and maintenance of renal cancer mainly through binding to 3'-untranslated regions (3'UTR) of target mRNAs, which causes a block of translation and/or mRNA degradation. The aim of the present study was to investigate the potential effects of miR-122 in human renal cell carcinomas. Methods: The expression level of miR-122 was quantified by qRT-PCR. MTT, colony formation, invasion and migration assays were used to explore the potential functions of miR-122 in human renal cell carcinoma cells. Results: Cellular growth, invasion and migration in two A498 and 786-O cells were significantly increased after miR-122 transfection. Further experiments demonstrated that overexpression of miR-122 resulted in the increase of phospho-Akt (Ser473) and phospho-mTOR (Ser2448), then activation of mTOR targets, p70S6K and 4E-BP1. Conclusions: The up-regulation of miR-122 may play an important role in the progress of renal cancer through activating PI3K/Akt signal pathway and could be a potential molecular target for anti-cancer therapeutics.

• Journal of Korea Multimedia Society
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• v.21 no.9
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• pp.1076-1089
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• 2018

Respiration is the process of moving air into and out of the lung. Respiration changes the temperature in the chamber while exchanging energy. Especially the temperature of the face. Respiration monitoring using an infrared camera measures the temperature change caused by breathing. The conventional method assumes that motion is not considered and measures respiration. These assumptions can not accurately measure the respiration rate when breathing moves. In addition, the respiration rate measurement is performed by counting the number of peaks of the breathing waveform by displaying the position of the peak in a specific window, and there is a disadvantage that the breathing rate can not be measured accurately. In this paper, we use KLT tracking and block matching to calibrate limited weak movements during breathing and extract respiration waveform. In order to increase the accuracy of the respiration rate, the position of the peak used in the breath calculation is calculated by converting from a single point to a high resolution. Through this process, the respiration signal could be extracted even in weak motion, and the respiration rate could be measured robustly even in various time windows.

• Journal of Korean Neurosurgical Society
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• v.52 no.5
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• pp.491-494
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• 2012

We report a rare complication of iatrogenic spinal intradural following minimally invasive extradural endoscopic procedues in the lumbo-sacral spines. To our knowledge, intradural cyst following epiduroscopy has not been reported in the literature. A 65-year-old woman with back pain related with previous lumbar disc surgery underwent endoscopic epidural neuroplasty and nerve block, but her back pain much aggravated after this procedure. Postoperative magnetic resonance imaging revealed a large intradural cyst from S1-2 to L2-3 displacing the nerve roots anteriorly. On T1 and T2-weighted image, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent partial laminectomy of L5 and intradural exploration, and fenestration of the cystic wall was accomplished. During operation, the communication between the cyst and subarachnoid space was not identified, and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the pain attenuated immediately. Incidental durotomy which occurred during advancing the endoscope through epidural space may be the cause of formation of the intradural cyst. Intrdural cyst should be considered, if a patient complains of new symptoms such as aggravation of back pain after epiduroscopy. Surgical treatment, simple fenestration of the cyst may lead to improved outcome. All the procedures using epiduroscopy should be performed with caution.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.6
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• pp.1091-1098
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• 2009

In this paper, we designed the authentication system for home network service and applied it to actual sensor nodes. The pair-wise pre-distribution key skim is applied for prevention of authentication key from sniffing on the wireless sensor networks. The authentication key and data are encrypted by using the CBC mode RC5 algorithm based on the SPINS. The experimental environment consists of a base station (BS)and sensor nodes and each sensor node sends both sensing data and the encrypted authentication key to the BS. For simulations we set up some what-if scenarios of security menaces in home network service.Slightly modified the TOS_Msg data arrays of TinyOS is suggested to store 8-byte authentication key which can enable data encryption and authentication at the each sensor node. As a result, malfunction caused by communication between BS and nodes of other groups of added nodes having malicious purpose can be protected. Also, we confirmed that a critical data of home networking service like vital signal can be transmitted securely through this system by encryption technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1C
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• pp.69-77
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• 2002

Sine digital signal processing for motion pictures requires huge amount of data computation to store, manipulate and transmit, more effective data compression is necessary. Therefore, the ITU-T recommended H.26x as data compression standards for digital motion pictures. The data compression method that eliminates time redundancies by motion estimation using relationship between picture frames has been widely used. Most video conding systems employ block matching algorithm for the motion estimation and compensation, and the algorithm is based on the minimun value of cast functions. Therefore, fast search algorithm rather than full search algorithm is more effective in real time low data rates encodings such as H.26x. In this paper, motion estimation employing the Nearest-Neighbors algorithm is designed to reduce search time using FPGA, coded in VHDL, and simulated and verified using Xilink Foundation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.767-774
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• 2007

A new transmit antenna selection and shuffling($AS^2$) method for spatially correlated double space time transmit diversity(DSTTD) systems is proposed. The proposed method allows dumb antennas and the superposition of multiple signals at the same transmit antenna, whereas the conventional methods consider the antenna shuffling(AS) only. According to the simulation result, the proposed method provides a 1.8 dB signal-to-noise ratio(SNR) gain over the conventional methods for spatially correlated transmit antennas. Although the number of candidates for $AS^2$ is much higher than that of AS, it is found that the number of candidates for $AS^2$ can be reduced to 36 by using the characteristics and properties of preprocessing matrices, and among them, only 6 candidates are almost always chosen. Next, we empirically compare the bit-error-rate (BER) performance of the proposed method with the conventional spatial multiplexing(SM) technique with antenna selection. Simulation results show that the proposed method outperforms the SM technique.

• Journal of Satellite, Information and Communications
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• v.3 no.2
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• pp.1-6
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• 2008

Space-time codes (STC) can achieve the diversity gain in a multi-path environment without additional bandwidth requirement. Recent study results reported that satellite systems can also achieve this diversity gain by using space-time codes in a cooperative network with terrestrial repeaters. Due to uni-directional nature of satellite DMB services, transmit diversity can be considered as one of the most effective ways to improve the performance. In this paper, we demonstrate various simulations results of STC schemes which can contribute to improve performance of future satellite DMB services. The STC schemes introduced in this paper provides diversity gains by combing independent coded signal from the satellite as well as from the terrestrial repeaters. In addition, we discuss a few points which should be considered to develop and implement these STC schemes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.4
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• pp.172-179
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• 1988

A cartridge type hydraulic logic valve consists of simple two port valve whose poppet is closed or opened by means of pressure signal of a pilot line. Accordingly, the logic valve can be used not only for direction, flow and pressure control purpose but also for versatile function valve which enables all above mentioned functions. In addition, the valve has little internal leakage and pressure loss, superior response characteristics and easiness in making small block type valve. The above mentioned good performances being recognized recently, the logic valve has been used widely in the large scale hydraulic system such as a hydraulic press system, for the performance requirements of high speed operation and precise control characteristics. However, there are scarce reports until now, except for a few ones from Aachen Institute of Technology in West Germany, so it is necessary to be studied on development and investigation for practical application. This paper showed that the static and dynamic characteristics of a logic valve when the logic valve is used for directional control, to investigate the relations between the valve operating characteristics and the valve design conditions. From the above mentioned procedure, it was ascertained that the valve operation characteristics obtained by numerical analysis showed good agreements with experimental results. The representative results obtained are as follows; 1. During the valve is closing, the poppet velocity is almost constant in the logic valve. 2. The pilot pressure P sub(3) and the resistance R in the pilot line have much influences on the valve operation time. 3. Spring strength have not such a severe influence on the valve operating time. 4. The operation characteristics of the logic valve can be estimated with good accuracy comparatively by numerical analysis with the equations describing poppet motion.