• The Journal of the Acoustical Society of Korea
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• v.11 no.3
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• pp.5-13
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• 1992

Taking devantage of the property that Korean digit is a mono-syllable word, we proposed a spoken Korean-digit recognition scheme using the multi-layer perceptron. The spoken Korean-digit is divided into three segments (initial sound, medial vowel, and final consonant) based on the voice starting / ending points and a peak point in the middle of vowel sound. The feature vectors such as cepstrum, reflection coefficients, ${\Delta}$cepstrum and ${\Delta}$energy are extracted from each segment. It has been shown that cepstrum, as an input vector to the neural network, gives higher recognition rate than reflection coefficients. Regression coefficients of cepstrum did not affect as much as we expected on the recognition rate. That is because, it is believed, we extracted features from the selected stationary segments of the input speech signal. With 150 ceptral coefficients obtained from each spoken digit, we achieved correct recognition rate of 97.8%.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.15-16
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• 2012

General lighting will be replaced into LED due to the high efficiency, low power consumption, long life than conventional light, moreover, since it is a basically semiconductor device that can convert the electric energy to visible light at a very high speed, using these characteristics can be performed communication modulation via the high-speed ON-OFF switching. Recently, visible light communication (VLC: Visible Light Communication) technology is received attention and there have been many researches. This paper is implemented media signal transmission by combining LED with VLC, a transmitter used the LED light-emitting device and receiver used an infrared sensor. In order to increase the efficiency of the communication system to improve the existing LED visible light communication driver of power conversion efficiency and thermal issues that is applied to the visible light communication in order to improve the speed of transmission media to research a new way of LED driver.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1791-1801
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• 2013

Diketopiperazine is produced by various organisms, including bacteria, fungi, and animals, and has been suggested as a novel signal molecule involved in the modulation of genes with various biological functions. Vibrio vulnificus, which causes septicemia in humans, produces cyclo($\small{L}$-phenylalanine-$\small{L}$-proline) (cFP). To understand the biological roles of cFP, the effect of the compound on the expression of the total mRNA in V. vulnificus was assessed by next-generation sequencing. Based on the transcriptomic analysis, we classified the cFP-regulated genes into functional categories and clustered them according to the expression patterns resulted from treatment with cFP. From a total of 4,673 genes, excepting the genes encoding tRNA in V. vulnificus, 356 genes were up-regulated and 602 genes were down-regulated with an RPKM (reads per kilobase per million) value above 3. The genes most highly induced by cFP comprised those associated with the transport and metabolism of inorganic molecules, particularly iron. The genes negatively regulated by cFP included those associated with energy production and conversion, as well as carbohydrate metabolism. Noticeably, numerous genes related with biofilm formation were modulated by cFP. We demonstrated that cFP interferes significantly with the biofilm formation of V. vulnificus.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.87-99
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• 2002

This paper describes a method for overcoming the motion artifacts inherent in synthetic aperture(SA) imaging. based on the investigation results as to the influence of a target motion on synthetic aperture techniques. This method uses a region-based motion compensation approach in which only the axial motion is estimated and compensated for a given region of interest(ROI) under the assumption that the whole ROI moves uniformly The estimated axial motion is calculated with a crosscorrelation(CC) method at the Point where the focused signal has the maximum energy within the ROI. We also presents a method for estimating the axial motion using the autocorrelation(AC) method that is widely used to estimate average Doppler frequency Both computer simulations and in vivo experiments show that the proposed methods can improve greatly the spatial resolution and SNR of ultrasound imaging by implementing the SA techniques for two-way dynamic focusing without motion artifacts. In addition the AC-barred motion compensation method provides almost the same results as the CC-based one, but with a dramatically reduced computational complexity.

• Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.311-318
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• 2013

The gene encoding an esterase from Photobacterium sp. MA1-3 was cloned in Escherichia coli using the shotgun method. The amino acid sequence deduced from the nucleotide sequence (948 bp) corresponded to a protein of 315 amino acid residues with a molecular weight of 35 kDa and a pI of 6.06. The deduced protein showed 74% and 68% amino acid sequence identities with the putative esterases from Photobacterium profundum SS9 and Photobacterium damselae, respectively. Absence of a signal peptide indicated that it was a cell-bound protein. Sequence analysis showed that the protein contained the signature G-X-S-X-G included in most serine-esterases and lipases. The MA1-3 esterase was produced in both soluble and insoluble forms when E. coli cells harboring the gene were cultured at $18^{\circ}C$. The enzyme was a serine-esterase and was active against $C_2$, $C_4$, $C_8$ and $C_{10}$ p-nitrophenyl esters. The optimum pH and temperature for enzyme activity were pH 8.0 and $30^{\circ}C$, respectively. Relative activity remained up to 45% even at $5^{\circ}C$ with an activation energy of 7.69 kcal/mol, which indicated that it was a cold-adapted enzyme. Enzyme activity was inhibited by $Cd^{2+}$, $Cu^{2+}$, $Zn^{2+}$, and $Hg^{2+}$ ions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1585-1593
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• 2005

The genetic effects of restraint stress challenge on HPA axis and the therapeutic effect of Boshimgeonbi-tang on the stress were studied with cDNA microarray analyses, RT-PCR on hypothalamus using an immobilization-stress mice as an animal model. Male CD-1 mice were restrained in a tightly fitted and ventilated vinyl holder for 2hrs once a day, and this challenge was repeated for seven· consecutive days. In the change of body weight it showed that the Boshimgeonbi-tang is effected recovery on weight loss caused by the immobilization-stress. Seven days later, total RNA was extracted from the organs of the mouse, body-labeled with $CyDye^{TM}$ fluorescence dyes and then hybridized to CDNA microarray chip. Scanning and analyzing the array slides were carried out using GenePix4000 series scanner and GenePix $Pro^{TM}$ analyzing program, respectively. The expression profiles of 109 genes out of 6000 genes on the chip were significantly modulated in hypothalamus by the immobilization stress. Energy metabolism-, lipid metabolism-, apoptosis-, stress protein, transcriptional factor, and signal transduction-related genes were transcriptionally activated whereas DNA repair-, protein biosysthesis-, and structure integrity-related genes were down-regulated in hypothalamus. The 58 genes were up-regulated by the mRNA expression folds of 1.5 to 7.9. and the 51 genes were down-regulated by 1.5 - 5.5 fold. The 11 genes among them were selected to confirm the expression profiles by RT-PCR. The mRNA expression levels of Tnfrsf1a (apoptosis), Calm2 (cell cycle), Bag3 (apoptosis), Ogg1 (DNA repair), Aatk (apoptosis), Dffa (apoptosis), Fkbp5 (protein folding) were restored to the normal one by the treatment of Boshimgeonbi-tang.

• Journal of Microbiology
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• v.44 no.4
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• pp.369-374
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• 2006

To investigate the mechanism of salt tolerance of gram-positive moderately halophilic bacteria, two-dimensional gel electrophoresis (2-D PAGE) was employed to achieve high resolution maps of proteins of Halobacillus dabanensis $D-8^T$. Approximately 700 spots of proteins were identified from these 2-D PAGE maps. The majority of these proteins had molecular weights between 17.5 and 66 kDa, and most of them were distributed between the isoelectric points (pI) 4.0 and 5.9. Some protein spots were distributed in the more acidic region of the 2-D gel (pI <4.0). This pattern indicated that a number of proteins in the strain $D-8^T$ are acidic. To understand the adaptation mechanisms of moderately halophilic bacteria in response to sudden environmental changes, differential protein profiles of this strain were investigated by 2-D PAGE and $Imagemaster^{TM}$ 2D Platinum software after the cells were subjected to salt shock of 1 to 25% salinity for 5 and 50 min. Analysis showed 59 proteins with an altered level of expression as the result of the exposure to salt shock. Eighteen proteins had increased expression, S proteins were induced, and the expression of 33 proteins was down-regulated. Eight of the up-regulated proteins were identified using MALDI-TOF/MS and MASCOT, and were similar to proteins involved in signal transduction, proteins participating in energy metabolism pathways and proteins involved in stress.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2100-2112
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• 2011

An orthogonal code hopping multiplexing (OCHM) technique has been proposed for accommodating a large number of users with low channel activities than the number of orthogonal codewords through statistical multiplexing in downlink cellular systems. In this paper, a multiple input multiple output (MIMO) antenna based OCHM system is proposed to improve the performance. Each modulated symbol is repeated N times and the N repeated symbols are transmitted simultaneously using N transmit antennas. Through repetitions, the effect of perforations that the OCHM system experiences is decentralized among the repeated symbols and the full perforation probability is significantly reduced. Each receiver detect the transmitted signal using its pre-assigned code hopping pattern. Simulation results show that the proposed scheme saves the required energy for a given frame error rate (FER).

• Explosives and Blasting
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• v.38 no.1
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• pp.14-22
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• 2020

Bit damage is one of the primary causes of decreasing drilling efficacy. Nevertheless the management of bit ware and failure are often left for field engineers' experience. Thus it is imperative to establish a proper system to predict and manage the bit damage during the rock drilling process. In this study, the drilling sound signal has been recorded and analyzed using wavelet transform analysis to identify the exact moment of bit failure. Through the analysis wavelet time-frequency spectrums have been constructed and an abnormal point has been identified with 0.9 of wavelet transform value at the 652.8s on a frequency band around 500Hz. Furthermore it is also observed that the penetration rate of the damaged bit has been decreased to 23mm/s which is 9mm/sec lower than the average of undamaged bit. The study verifies that wavelet transform analysis can be used to build a system to diagnose the bit damage while drilling.