• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.3-8
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• 2002

A new Modem technique - 8-state Superposed QAM(8SQAM) - for use in power and bandwidth limited digital communication system is proposed. The premodulation baseband signal of the 8SQAM system is a double-interval(2Ts) raised cosine pulse superposed with weighted single-interval(Ts) raised cosine pulse. The performance of the 8SQAM, in a nonlinearly amplified multi-channel environment with additive white Gaussian noise(AWGN), inter-symbol interference(ISI), inter-modulation(IM) and adjacent channel interference(ACI), is analyzed via computer simulation. The simulation result shows that the 8SQAM outperforms 8PSK by about 1.6㏈ at BER=$1\times10^{-4}$ when HPA IBO is 1㏈ and channel Spacing, ${\Delta}F$ is 0.417fb.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.62-67
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• 2022

This study is to construct the simple estimating model for the HIC15 of the driver dummy using the frontal impact test results. Test results of 9 vehicles of Hyundai Sonata from the MY2002~MY2020 USNCAP are utilized for constructing the linear regression model. The average accelerations extracted from the vehicle crash pulses are handled as the main factors. The average accelerations of 10 ms interval within 0~100 ms are calculated from the crash pulse data of 9 vehicles. The present estimating model of the HIC15 using the average accelerations of 10 ms interval in the 0~80 ms range shows good agreement with the tested value within 2.4% maximum error.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.732-737
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• 2016

A pulse radar signal exhibits periodic appearance of pulses in time. So it leads to a high correlation between two samples separated in time by multiples of its period. In this paper, we present a spectrum sensing technique for a radar signal which exploits the periodicity of its autocorrelation function and a radar pulse interval estimation scheme in order to address the case that the radar pulse interval is not known a priori. Finally, we evaluate the sensing performance of the proposed scheme through computer simulation and compare its performances with those of energy detection.

• Biomedical Science Letters
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• v.15 no.4
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• pp.265-272
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• 2009

Recently, mesenchymal stem cells (MSCs) began to be utilized as a vehicle for ex vivo gene therapy based on their plasticity. Effective and safe transfection of therapeutic genes is a critical step for genetic modification of MSCs. Therefore, optimization of in vitro gene delivery into MSCs is essential to provide genetically modified stem cells. In this study, various cationic liposomes, O,O'-dimyristyl-N-lysyl aspartate (DMKD), DMKD/cholesterol, O,O'-dimyristyl-N-lysyl glutamate (DMKE), DMKE/cholesterol, and N-[1-(2,3-dioleoyloxy)]-N,N,N-trimethylammonium propane methyl sulfate (DOTAP)/cholesterol, were mixed with plasmid DNA encoding luciferase (pAAV-CMV-Luc) at varied ratios, and then used for transfection to MSCs under varied conditions. The MSCs were also transfected by electroporation under varied conditions, such as voltage, pulse length, and pulse interval. According to the experimental results, electroporation-mediated transfection was more efficient than cationic liposome-mediated transfection. The best MSC transfection was induced by electroporation 3 times pulses for 2 ms at 200 V with 10 seconds of a pulse interval.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.347-359
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• 1992

The movements of three striped jack (Caranx delicatissimus, 24cm of body length) were tracked by ultrasonic telemetry in the Nunoura Bay in August 1990. A school of the striped jack has been released near by the fish farming rafts by Goto branch of the Fisheries Agency and Japan Sea-Farming Association. To investigate the staying area and the swimming pattern of the fish, small size pinger($\Phi$8.5$\times$L35mm, 140dB re 1$\mu$Pa at 1m, 69kHz) was tagged on the dorsal fin without any anesthesia. The movements of three tagged fish are monitored at the same time with four omni-directional hydrophones. The locations of the fish are calculated by the hyperbolic method and tracked by a technique so called time division scheme which uses both the pulse interval and the phase. Three pingers used have the pulse interval of 1.7, 1.8 and 1.9sec, respectively, and the common pulse duration of 15ms. In results it was capable to estimate behavior right after the release, swimming speeds and approximate moving area of the fish. The movements were tracked for a week continuously, and it was found out that the staying area of the fish was around or under the farming rafts. Sometimes they swam together but most of the time they move separately. The average swimming speed of those fish was about two times of the body length.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.115-120
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• 1999

This research is a described result of experimental for the parameter's effecting the microhole machining by Nd-Yag laser, The parameters are energy, pulse interval time a kin of assisting gas and its pressure. The result reveals that parameter value of energy 0.08J, pulse 20Hz, interval time of 300 microseconds could be a good machining condition to make upper microhoel that is the diameter range of 50-70${\mu}{\textrm}{m}$. At tat time the assistant gas such air, $O_2$, Ar $N_2$, was appelied. Assistant gas of air makes heat affected zone enlarge due to burning of material surface. Also it makes microhole irregular and damageable. Because of refusion caused by chemical reaction with $Al_2O_3$ ceramic material . The $O_2$(99.9%) has good characteristics to get good drilling and smooth surface on pressure of 0.2kgf/$\textrm{cm}^2$ but it is expensive. Ar, $N_2$ make material crack and burnning and proved that to be unappropriate but, Ar was a better than $N_2$.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.183-187
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• 2016

The aim of this study was to assess the association between microalbumin and pulse pressure (PP) in Korean adults. The study subjects were Korean adults 20 years or older (n=4,948) who participated in the Korea National Health and Nutrition Examination Survey 2012. The urine microalbumin level ($M{\pm}SE$) was significantly higher (p=0.047) in the high PP group (PP>60.0 mmHg) [$33.02{\pm}4.93{\mu}g/mL$ (95% confidence interval (CI), 23.37~42.68)] than the normal PP group ($PP{\leq}60.0mmHg$) [$22.57{\pm}1.63{\mu}g/mL$ (95% CI, 19.36~25.77)], after adjusting for age, gender, smoking, drinking, regular exercising, WM, BMI, TC, TG, HDL-C, FBG, BUN, creatinine, and urine creatinine. In conclusion, pulse pressure was associated with the microalbumin level in Korean adults.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.98-105
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• 2003

We propose a new technique of deinterleaving multiple radar pulse sequences by means of genetic algorithm for threat identification in electronic warfare(EW) system. The conventional approaches based on histogram or continuous wavelet transform are so deterministic that they are subject to failing in detection of individual signal characteristics under real EW signal environment that suffers frequent signal missing, noise, and counter-EW signal. The proposed algorithm utilizes the probabilistic optimization procedure of genetic algorithm. This method, a time-of-arrival(TOA) only strategy, constructs an initial chromosome set using the difference of TOA. To evaluate the fitness of each gene, the defined pulse phase is considered. Since it is rare to meet with a single radar at a moment in EW field of combat, multiple solutions are to be derived in the final stage. Therefore it is designed to terminate genetic process at the prematured generation followed by a chromosome grouping. Experimental results for simulated and real radar signals show the improved performance in estimating both the number of radar and the pulse repetition interval.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.202-208
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• 2010

This study reports developmental changes in the vocal signals produced by infant or young Pipistrellus abramus. In contrast to adult bats, infant bats of the P. abramus emitted calls characterized by multi harmonics and variable signal patterns. Infants at two day of age emitted a irregular signal and showed gentle FM signals between 10 and 20 days. After about 40 days of age, the young bats emitted similar signals to the echolocation calls of adults. As the infant bats growing up, vocal signals trend showen a decrease in pulse duration(p<0.001), pulse interval(p<0.001) and number of harmonic(p<0.001). And the peak frequency(p<0.001), starting frequency(p<0.001) and ending frequency(p<0.001) in infant bats increased with the age. The largest change in pulse interval occurred in 5 days. And the pulse duration, peak frequency, starting frequency and ending frequency of the bat's sounds changed most dramatically in 25 days of age.

• Journal of Environmental Science International
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• v.32 no.9
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• pp.659-669
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• 2023

The purpose of this study is to predict the pressure drop due to the installation of venturi under diverse operating conditions such as dust concentration, pulse interval and pressure, and filtration velocity using algebraic-linear regression model and use it as an economic data and efficient operating condition for a pulse air jet bag filter. A pilot scale bag filter with a filter a filter size(Ø140 × 850ℓ, 12) was used, and the filters used in the experiment were the polyester filters most commonly used in real industrial sites. The SAS 9.4 program (SAS Institute, USA) was used to predict and to determine the effects of inlet concentration (C_i), pulse interval (P_i) and pressure (P_p), filtration velocity (V_f), presence or absence of venturi, etc. The results are shown below. The variation in pressure drop with or without venturi installation was 38.8 mmAq when venturi is installed and 47.6 mmAq when venturi is not installed, indicating a difference in pressure drop of 8.8 mmAq depending on venturi installation. It is estimated that the efficiency can be improved by about 18.5% if the venturi is installed.