• Science of Emotion and Sensibility
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• v.12 no.3
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• pp.299-306
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• 2009

In this study, pulse waves were measured at radial artery using non-invasive tonometric pulse pressure measurement system, SphygmoCor(AtCor, Australia), according to subject's posture. Then it was analysed whether the pulse wave parameters, which contain heart activities, change among three different postures (upright stand, sit, and supine). And it was also verified that the pulse wave parameters change among blood pressure level groups(hypotensive, normotensive, and hypertensive). As a results, posture effects were verified in time information of pulse wave rather than amplitude. But some parameters calculated by ratio of two amplitude, such as augmented index(AI) and ratio of central aortic pulse and radial artery pulse, showed significant difference according to postures. In post hoc test, time to the $1^{st}$ and $2^{nd}$ pulse peak(P_$T_1$, and P_$T_2$), ED(ejection duration), and HR(heart rate) showed significant difference among posture groups with each other. In comparison of blood pressure groups, it was verified that the parameters related to amplitude of pulse wave showed significant difference rather than time information.

• Journal of IKEEE
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• v.16 no.3
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• pp.217-223
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• 2012

This paper presents design and operational characteristics of 150 MW pulse power system for high current pulse forming network to control trigger time. The system is composed of two capacitor bank modules. Each capacitor bank module consist of a trigger vacuum switch, 9k 33kJ capacitor, an energy dump circuit, a crowbar circuit and a pulse shaping inductor and is connected in parallel. It is controlled by trigger controller to select operational module and determine triggering time. Pspice simulation was conducted about determining parameters of components such as crowbar circuit, capacitor, pulse forming inductor, trigger vacuum switch and predicting results of experiment circuit. The result of the experiment was in good agreement with the result of the simulation. The various current shapes with 300~650 us pulse width is formed by sequential firing time control of capacitor bank module. The maximum current is about 40 kA during simultaneous triggering of two capacitor bank modules. The developed 150 MW pulse power system can be applied to high current pulse power system such as rock fragmentation power sources, Rail gun, Coil gun, nano-powers, high power microwave.

• The Journal of the Acoustical Society of Korea
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• v.14 no.4
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• pp.5-11
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• 1995

In this paper, we design the new high-speed seek algorithm which can access the data of disk (in 3.5-inch optical disk drive). When seek the target track on optical disk in high-speed using the ref-T. E(Reference Tracking Error) and sample pulse signal, it's always possible high-speed seek without re-check and compensation for error by the ref_T. E and sample pulse signal. The performance test result is represented as follow ; it is satify the average seek time of 28mses.

• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.63-70
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• 2008

This paper presents a method of PRI do-interleaving for LASER pulse signals. When the PRI of LASER pulse is periodically changed, the first deviation and the second deviation of TOA is used to calculate the PRI pattern of input LASER signals of receiver. If the standard deviation of the first difference of TOA is less than 5% of the average of the first difference of TOA, the PRI pattern of LASER signal is fixed or jittered type. If the standard deviation is larger than 5% of the average, those are triangular PRI patterns or sawtooth PRI patterns.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.486-493
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• 2015

The ultrasonic nondestructive test (NDT) was applied to deck in-service to inspect and evaluate the performance of decking materials using ultrasonic pulse velocity. First, the measuring method between direct and indirect method according to transducer arrangement was studied. Second, the ultrasonic pulse velocity of decks in-service was compared with the passage of time. Finally, the change of ultrasonic pulse velocity was evaluated to expect service life of decking materials. The results of comparison between direct and indirect method was statistically insignificant and the ratio of direct to indirect method was 1.02. 1.05 respectively. The ultrasonic pulse velocity of decks in-service was decreased as the passage of time and the linear relationship in the ultrasonic pulse velocity to passage of time was found. From the results, The ultrasonic NDT will be helpful as an efficient method of on-site management of decks in-service.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.137-144
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• 2014

The Electronic Support System collects and analyzes the received radar signals in order to cope with the electronic attack in real-time. The radar-pulse clustering system classifies the radar signals that are considered to be emitted by a single source. This paper proposed a radar-pulse clustering algorithm based on four kinds of features: the direction, frequency, pulse width, and the difference of arrival time between two successive pulses. The experiment results show that the proposing algorithm could trace the moving emitter and classify the timely separated signals into different classes.

• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.887-896
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• 2016

The Neyman-Scott Rectangular Pulse (NSRP) model is used to model the hourly rainfall series. This model uses a modest number of parameters to represent the rainfall processes and underlying physical phenomena such as the arrival of a storm or rain cells. In this paper, we proposed approximated likelihood function for the NSRP model and applied the proposed method to precipitation data in Seoul.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1105-1116
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• 2014

A stochastic rainfall model, NSRPM (Neyman-Scott Rectangular Pulse Model), is able to reflect the cluster characteristics of rainfall events which is unable in the RPM (Rectangular Pulse Model). Therefore NSRPM has advantage in the hydrological applications. The NSRPM consists of five model parameters and the parameters are estimated using optimization techniques such as DFP (Davidon-Fletcher-Powell) method and genetic algorithm. However the DFP method is very sensitive in initial values and is easily converge to local minimum. Also genetic algorithm has disadvantage of long computation time. Nelder-Mead method has several advantages of short computation time and no need of a proper initial value. In this study, the applicability of parameter estimation methods was evaluated using rainfall data of 59 national rainfall networks from 1973-2011. Overall results demonstrated that accuracy in parameter estimation is in the order of Nelder-Mead method, genetic algorithm, and DFP method.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.137-143
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• 2015

A delay-line type time-to-digital converter (TDC) implemented in a field-programmable gate array (FPGA) is most widely owing due to its simple structure and high conversion rate. However, the delay-line type TDC suffers from nonlinearity error caused by the long delay-line because its time interval measurement range is determined by the length of the used delay line. In this study, a new TDC structure with a shorter delay line by taking a pulse train as an input is proposed for improved time accuracy and efficient use of resources. The proposed TDC utilizes a pulse-train with four transitions and a transition state detector that identifies the used transition among four transitions and prevents the meta-stable state without a synchronizer. With 72 delay cells, the measured resolution and maximum non-linearity were 20.53 ps, and 1.46 LSB, respectively, and the time interval measurement range was 5070 ps which was enhanced by approximately 343 % compared to the conventional delay-line type TDC.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.60-65
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• 2009

In this paper, we propose a new exponential pulse shaping function based on Chebychev identity equation and Bessel coefficients. The proposed pulse shaping function can produce various pulses with the different characteristics in the time and frequency domain by changing its two parameters. By differentiating the exponential pulse shaping function, we obtain new different pulse functions, in which the even order derivatives of the exponential pulse shaping function are orthogonal to its odd order derivatives. To find the efficiency of the proposed exponential pulse shaping function we analyze its essential characteristics and compare them with those of the conventional Gaussian pulses. We can choose the most suitable exponential pulse waveform according to the design criteria of communication systems.