• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.175-178
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• 1992

This paper proposes a method called linear prediction (a high performant technique in digital speech processing) for analyzing digital ECG signals. There are several significant properties indicating that ECG signals have an important feature in the residual error signal obtained after processing by Durbin's linear prediction algorithm. The ECG signal classification puts an emphasis on the residual error signal. For each ECG's QRS complex. the feature for recognition is obtained from a nonlinear transformation which transforms every residual error signal to set of three states pulse-cord train relative to the original ECG signal. The pulse-cord train has the advantage of easy implementation in digital hardware circuits to achive automated ECG diagnosis. The algorithm performs very well feature extraction in arrythmia detection. Using this method, our studies indicate that the PVC (premature ventricular contration) detection has a at least 90 percent sensityvity for arrythmia data.

• Journal of information and communication convergence engineering
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• v.8 no.2
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• pp.205-211
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• 2010

In this study, a Magnetic stimulation Pulse Train control technique is introduced and applied to Flyback converter operating in discontinuous conduction mode. In contrast to the conventional pulse width modulation control scheme, the principal idea of a Magnetic stimulation Pulse Train is to achieve output voltage regulation using high and low power pulses. The proposed technique is applicable to any converter operating in discontinuous conduction. However, this work mainly focuses on Flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.361-362
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• 2009

High-order harmonics from gaseous atoms driven by an intense femtosecond laser pulse can form an attosecond pulse train. By selecting suitable harmonic generation conditions, the harmonic spectrum can be broad enough to form sub-hundred attoseconds. One serious limitation, however, comes from the inherent attosecond chirp originating from the harmonic generation process. We have proposed to compensate for the positive attosecond chirp by making use of negative group delay dispersion of a metallic x-ray filter or a gaseous medium. We generated 240-as pulses from neon and compressed them to 60 as after propagating through argon, close to the transform-limited duration of 47 as.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.748-750
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• 2004

The pantograph should supply the electrification equipments of a train with the current from the overhead catenary system over a broad range of speeds. For a high-speed electrical train, the dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force. As the operational speed increases, the variation of the contact force increases. The contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the dynamic characteristics analysis between pantograph and catenary system using block pulse function.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.2
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• pp.204-210
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• 1988

The residue number system offers the possibility of high-speed operation and error detection/correction because of the separability of arithmetic operations on each digit. A compact residue arithmetic module named the self-checking pulse-train residue arithmetic circuit is effectively employed as the basic module, and an efficient error detection/correction algorithm in which error detection is performed in each basic module and error correction is performed based on the parallelism of residue arithmetic is also employed. In this case, the error correcting circuit is imposed in series to non-redundant system. This design method has an advantage of compact hardware. Following the proposed method, a 2nd-order recursive fault-tolerant digital filter is practically implemented, and its fault-tolerant ability is proved by noise injection testing.

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.157-158
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• 2008

High-order harmonics from gaseous atoms driven by an intense femtosecond laser pulse can form an attosecond pulse train. By selecting suitable harmonic generation conditions, the harmonic spectrum can be broad enough to form sub-hundred attoseconds. One serious limitation, however, comes from the inherent attosecond chirp originating from the harmonic generation process. We have proposed to compensate for the positive attosecond chirp by making use of negative group delay dispersion of a metallic x-ray filter or a noble gas. We generated 241-as pulses from neon and compressed them to 106 as after propagating through argon, close to the transform-limited duration of 98 as.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.8
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• pp.673-681
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• 2002

This paper presents a new algorithm for estimating pulse repetition intervals (PRIs) of stagger PRI pulse trains using a 2 dimensional TDOA histogram. The PRI transform algorithm can remove harmonics of stable and jitter PRI pulse trains in a TDOA histogram. But, it is impossible for the algorithm to detect stagger PRI pulse trains because it regards frame PRIs of stagger Pulse trains as harmonics of stable PRI pulse trains. A new algorithm of this paper has an ability to distinguish stagger pulse trains from harmonics of other pulse trains and to estimate frame PRIs of detected pulse trains.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1182-1188
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• 2011

By storing various train information in running high speed train, we can analyze the cause of train accident efficiently. we have developed the smart and high available control method to control and manage the hardware modules. The hardware modules for event recorder consist CPU, Digital Input and Output, Pulse Input, Communication, Control Panel and Crash Protected Memory. The real time operation system is used to totally control and manage the various hardware modules. The main function of control method is collection of train information, calculation of train speed, interface with other on-board control system, storing and retrieving train information, and communication with Control Panel. In Control Panel, it displays the current train speed and the status of event recorder effectively. Also user interface is provided in Control Panel.

• 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.

• 전기의세계
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• v.29 no.5
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• pp.321-328
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• 1980

The Q-switching oscillator of TE $M_{00}$ mode was constructed in order to improve the properties of energy focusing and amplification, and prevent laser materials from breakdown. The Q-switching was done by means of electro-optical effect using Glan prism and KDP Pockels cell. Sharp laser pulse of risetime-1 ns and variable pulse width 2-10 ns was obtained from Q-switching laser pulse by PTM method using a laser triggered spark gap (LTSG), Glan prism and Pockels cell. A single ultra-short pulse (picosec order in pulse width) was obtained from mode-locked pulse train in combination of a mode-locked oscillator using saturable dye cell with pulse shaping system using PTM method.d.