• International Journal of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.273-281
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• 2024

The development of a radial pulse simulator is pivotal for advancing wearable medical devices and enhancing pulse diagnosis methods prevalent in Oriental medicine. Such a simulator can be utilized for the calibration of wrist-worn wearable device sensors, as well as for training medical professionals in pulse diagnosis. This study introduces a novel, simple, and cost-effective pulse simulator that can generate a wide range of blood pressure waveforms. This simulator was designed and constructed as a prototype pulse simulator using two precision solenoid valves, an air chamber, a Half-CAM, a pneumatic sensor, and electronic control systems. By regulating air pressure through controlled opening and closing of the solenoid valve, the simulator can produce the desired pulse waveform. The performance of the proposed simulator was evaluated by replicating age-related radial pulses. Pulse waveforms generated by the simulator for four representative age groups (10, 50, 60, and 90 years) were compared with corresponding in vivo data. The experimental results demonstrated that the RMSE (Root Mean Square Error) estimate between the simulated in vivo pulse data and the actual in vivo pulse data was within 10% in all age groups. These findings demonstrate that fine pneumatic control by a solenoid valve allows the generation of sophisticated waveforms and validate that the proposed pulse simulator is capable of generating a diverse range of pulse waveforms.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.239-246
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• 2006

This paper suggests a new modulation strategy for step pulse type multi-level inverter. The proposed strategy is simple to determine the switching angles without regard to increase of levels. Designed to extract the equivalent RMS value compared to ideal sine wave from inverter, it can be applied effectively to high level step pulse inverter. Also this paper proposed modulation strategy for modified H-bridge 13 level inverter which has different cell source voltages with simulation and experiment. The modulation characteristics from simulation and experiment, agreed very well with tracing sine wave about modified structure of cascaded H-bridge multi-level inverter.

• Journal of Environmental Science International
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• v.29 no.5
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• pp.457-468
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• 2020

With continuous industrial development, the types, and amount of particulate matter (PM) have been increasing. Since 2018, environmental standards regarding PM have become more stringent. Pulse air jet bag filters are suitable for PM under the 20 ㎛ and, can function regardless of size, concentration and type. Filtration velocity and shape are important factors in the operation and design of the pulse air jet bag filters however, few established studies support this theory. In this research, numerical simulations were conducted based on experimental values and, several methods were employed for minimizing the pressure drop. In the pilot system, as the inlet duct velocity was faster than 19 m/sec, flow was not distributed equally and, re-entrainment occurred due to the hopper directional vortex. The multi-inlet system decelerated the hopper directional vortex by 25 ~ 30%, thereby decreasing total pressure drop by 6.6 ~ 14.7%. The guide vane system blocked the hopper directional vortex, which resulted optimal vane angle of 53°. The total pressure of the guide vane system increased by 0.5 ~ 3% at 1.5 m/min conditions. However, the filtration pressure drop decreased by 4.8 ~ 12.3% in all conditions, thereby reducing the operating cost of filter bags.

• Journal of Power Electronics
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• v.15 no.1
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• pp.65-77
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• 2015

Resonant converters are well suited for induction heating (IH) applications due to their advantages such as efficiency and power density. The control systems of these appliances should provide smooth and wide power control with fewer losses. In this paper, a simple phase locked loop (PLL) based variable duty cycle (VDC) pulse density modulation (PDM) power control scheme for use in class-D inverters for IH loads is proposed. This VDC PDM control method provides a wide power control range. This control scheme also achieves stable and efficient Zero-Voltage-Switching (ZVS) operation over a wide load range. Analysis and modeling of an IH load is done to perform a time domain simulation. The design and output power analysis of a class-D inverter are done for both the conventional pulse width modulation (PWM) and the proposed PLL based VDC PDM methods. The control principles of the proposed method are described in detail. The validity of the proposed control scheme is verified through MATLAB simulations. The PLL loop maintains operation closer to the resonant frequency irrespective of variations in the load parameters. The proposed control scheme provides a linear output power variation to simplify the control logic. A prototype of the class-D inverter system is implemented to validate the simulation results.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.801-809
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• 2023

The purpose of this study is to predict the reflection distance following to the pulsing pressure, total air supplying, filter bag size using numercial analysis techniques and use it as an efficient operation condition and economic data for off-line type pulse air jet bag filter. In this research, filtration area 6 m² condition, calculate filter resistance coefficient for simulation through the main experiments using coke dust. Ansys fluent V19.0 apply to CFD simulation, and analysis pulsing characteristics about pulsing pressure, filtration velocity and nozzle diameter. The maximum reflecting distance of off-line type pulse air jet bag filter is 1,000 mm regardless of total air supplying at over the 42 L/m² conditions, that indicates off-line type can extend filter bag length 1,000 mm than on-line type. In order to effective primary and secondary pulsing of off-line type pulse air jet bag filter, over the 5 bar of pulsing pressure and over the 42 L/m² of total air supplying are needed.

• Journal of information and communication convergence engineering
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• v.5 no.2
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• pp.112-115
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• 2007

A CMOS TDC(time-to-digital converter) is proposed which has a simple cyclic structure. The proposed TDC consists of pulse-shrinking elements, D latches and D flip-flops. The operation is based on pulse-shrinking of the input pulse. The resolution of digital output can be easily improved by increasing the number of the pulse-shrinking elements, D latches and D flip flops. The TDC performance is improved in viewpoints of power consumption and chip area. Simulation results are shown to illustrate the performance of the proposed TDC circuit.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.4
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• pp.173-180
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• 2016

This paper presents a method to suppress multipath induced by pulses using supervised learning. In modern electronics, pulses have been used for various purposes such as communication or distance measurements. Like other signals, pulses also suffer from multipath. When a pulse and a multipath are overlapped, the original pulse shape is distorted. The distorted pulse could result in communication failures or distance measurement errors. However, a large number of samples available from a pulse can be used to effectively reject multipath by using a supervised learning method. This paper introduces how a supervised learning method can be applied to Distance Measuring Equipment. Simulation results show that multipath induced distance measuring error can be suppressed by 10 ~ 45 percent depending on the allowed pulse shape variation allowed in a standard.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.27-30
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• 2004

This paper has been designed the TDMG(Time Delay Multiple Gaussian) pulse generator for UWB systems and analyzed the characteristics of UWB impulse. Composite two equal Gaussian pulses in a difference time lag, and then investigated TDMG pulse and modeled mathematically. Designed the TDMG pulse generator by ADS(Advanced Design System) to embody by using actual element with such mathematical model. As well as, this paper finally proved an excellence of the TDMG pulse generator by performing analysis through simulation.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.313-316
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• 2004

In this paper analyzed characteristics of the exist ing pulse of the UWB system, modeled TDMG pulse generator without attenuation of pulse width, Then we designed UWB transceiver which load TDMG pulse generator. Result of Simulation, it had high data rate and low BER. As well as, satisfying the spectrum Mask recommended by the FCC

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.230-231
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• 2002

Recently, analysis of transient Raman backscattering in a plasma reported(2.3) that it is possible to reach 10$\^$17/ W/cm$^2$ for 1 micrometer wavelength laser pulse with a counter-propagating pump pulse. The basic mechanism is like this ： whorl the two counter-propagating waves in a plasma satisfy the condition of Raman backscattering, w$\_$0/ ： w$\_$1/ ＋ w$\_$p/, energy is transferred from the long pulse to the short pulse via three wave interaction(4). (omitted)