• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.1-6
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• 2012

In this paper, the performance comparison of the TR-UWB System using Wavelet Pulse, DPSS pulse, and second Gaussian pulse in multi-user environment is analyzed. The data signal and the reference signal is sent with some time intervals in TR-UWB system. At this time the two signals are through the same channel. In the receiver the reference signal is used as a template. This advantage results in demodulation without channel estimation and low complexity of it. However the conventional TR-UWB system based on a Gaussian signal in a multi-user environment has the disadvantage of poor performance due to the interferences between the users. To overcome this disadvantage, DPSS (Discrete Prolate Shperoidal Sequence) is used to reduce the interferences between the users. We propose the system with multiresolution function of orthogonal wavelet reducing the interferences, which has a better performance in multi-user environment when they are sent in transmission side.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.5
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• pp.238-244
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• 2005

This paper proposes a new configuration of 36-pulse voltage source converter which consists of two 6-pulse bridges and a pulse-interleaving auxiliary circuit. The system topology of proposed converter was derived to increase the pulse number of converter output voltage without increasing the number of 6-pulse bridges. The gate pulse generation was analyzed using the theoretical approach of multi-pulse switching converter, The operational feasibility of proposed system was verified by computer simulations with PSCAD/EMTDC software and experimental works with 2kVA hardware prototype. The proposed converter can be widely used for the uninterruptible power supply, the power quality compensator, and the distributed power generation, such as solar and fuel cell power system.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.6
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• pp.568-574
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• 2000

A new pulse multiplication technique based on 6-pulse thyristor converters is proposed in this paper. With the proposed technique, 12-pulse, 18-pulse and 24-pulse operations have been obtained both on the input current and on the output voltage. A control strategy over the whole range of phase angle is provided along with sophisticated input current and output voltage analysis. Experimental results from a laboratory prototype verify the proposed theory.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.31-35
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• 2004

This paper proposes a new configuration of 36-pulse voltage source converter which consists of two 6-pulse bridges and a pulse-interleaving auxiliary circuit. The system topology of proposed converter was derived to increase the pulse number of converter output voltage without increasing the number of 6-pulse bridges. The gate pulse generation was analyzed using the theoretical approach of multi-pulse switching converter. The operational feasibility of proposed system was verified by computer simulations with PSCAD/TMTDC software and experimental works with 3kVA hardware prototype. The proposed converter can be widely used for the uninterruptible power supply, the power quality compensator, and the distributed power generation, such as solar and fuel fell power system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.943-950
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• 2000

In this paper, an asynchronous multi-rate optical wireless pulse position modulation-code division multiple access (PPM-CDMA) is proposed for an indoor non-directed diffuse channel. As a signature sequence for CDMA, an optical orthogonal code (OOC) is used and an interference cancellation scheme is applied to improve the bit error rate. It is known that the optical PPM-CDMA has advantages due to its power efficiency. Moreover, it provides multi-rate services by varying the modulation level with fixed pulse duration. In the proposed multi-rate PPM-CDMA system with fixed pulse duration, chip rate and sampling time do not change for each transmission rate and this simplifies overall system structure.

• Journal of Magnetics
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• v.16 no.3
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• pp.234-239
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• 2011

Transcranial magnetic stimulation utilizes the method of controlling applied time and changing pulse by output pulse through power density control for diagnosis purposes. Transcranial magnetic stimulation can also be used in cases where diagnosis and treatment are difficult since output pulse shape can be changed. As intensity, pulse range, and pulse shape of the stimulation pulse must be changed according to lesion, the existing sine wave-shaped stimulation treatment pulse poses limitations in achieving various treatments and diagnosis. This study actualized a new method of transcranial magnetic stimulation that applies a 3 Stage 2 Switch( power semiconductor 2EA) for controlling pulse repetition rate by achieving numerous switching control of stimulation coil. Intensity, pulse range, and pulse shape of output can be freely changed to transform various treatment pulses in order to overcome limitations in stimulation treatment presented by the previous sine wave pulse shape. The method of freely changing pulse range by using 3 Stage 2 Switch discharge method is proposed. Pulse shape, composed of various pulse ranges, was created by grafting PFN (Pulsed Forming Network) through AVR AT80S8535 one-chip microprocessor technology, and application in transcranial magnetic stimulation was achieved to study the output characteristics of stimulation treatment pulse according to delaying time of the trigger signal applied in section switch.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1996-1999
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• 2002

Applying a higher frequency periodic control signal, a state of a chaotic pulse-train generator is quantized. The circuit has various co-existing super-stable periodic pulse-trains (ab. SSPTs) and generates one of them depending on the initial state. Also correlation characteristics of the SSPTs are analyzed precisely. We then consider application of the SSPTs to spread sequences of CDMA with pulse-train signals.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.36-38
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• 1989

We have developed Magnetic Pulse Compression System to realize repetitive excimer laser excitation. The principle of this system is to use the large change in permiability owing to the nolinear characteristics of ferro-magnetic material (Metglas2605s-2 metal ribon). Prior to the laser operation, the MPC system was tested with a dummy load (5$\Omega$) and laser head. Laser head has a discharge volume of 1.0 (w) x 2.0 (h) x 20.0(1) cm. This MPC system compressed a 6.2us (FWHM), 80 A pulse into a 0.4us(FWHM), 1.3kA pulse.

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.727-732
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• 2007

Objectives : This study investigated using National Institutes of Health Strokes Scale in acute and subacute stroke patients and evaluated relativity of pulse pattern to NIHSS. Methods : 104 acute and subacute stroke patients were selected from 4 oriental medical hospitals from April 2007 to May 2007. The patients were admitted to hospital within 1 month after stroke. Pulse feeling diagnosis was done by oriental medical doctor and classified into 7 subtypes. Results : There were significant results statistically between slow/rapid pulse and NIHSS score in the male group; in the female group, there were no significant results statistically but the results showed that slow pulse has lower NIHSS score than rapid pulse. Patients with surging pulse had lower NIHSS score than the other patients. Another pulse pattern had no relativity to NIHSS score.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.159-164
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• 1998

This paper proposes a SVPWM (space vector pulse width modulation) strategy for a multi-level voltage source inverter. This strategy is easily implemented as SPWM (sinusoidal pulse width modulation) and has the same DC-link voltage utilization as general SVPWM. The method to keep the voltage balancing of DC-link also is proposed by the analysis model of DC-link voltage fluctuation. The usefulness of the proposed SVPWM is verified through the simulation.