• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.146-151
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• 2021

We introduce an arbitrary waveform generation method and its H/W implementation case based on Rademacher and Walsh function. According to the orthogonal and periodic features of Rademacher and Walsh function, simple calculations can generate arbitrary waves with affordable logics. We implemented an FPGA-based AWS using above two functions, and verified. HDL simulation shows the proposed idea can draw desired analog test waveforms very fast, and its H/W size is promising to Built-Out Self-Test(BOST) logics for AI ICs.

• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.162-166
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• 2008

This paper presents the design and implementation of a 5kW programmable three-phase harmonic generator, which is capable of generating sinusoidal output voltages with adjustable output amplitude and frequency over a wide range as well as arbitrary waveforms. The considered harmonic generator is a linear power amplifier type. This system consists mainly of a power converter to generate and amplify waveform signals, a controller to control the desired output signal and measure the output parameters including voltage and current, and a control program to set the desired output and display the output values. The prototype programmable three-phase harmonic generator has been constructed and tested. Test results show that the developed programmable three-phase harmonic generator performs well.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.1
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• pp.58-64
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• 2016

This study presents a design method for a single-loop voltage controller that is suitable for an arbitrary waveform generator (AWG). The voltage control algorithm of AWG should ensure high dynamic performance and should attain sufficient robustness to disturbances such as inverter nonlinearity, sensor noise, and load current. By analyzing the power circuit of AWG, control limitation and control target are presented to improve the dynamic performance of AWG. The proposed voltage control algorithm is composed of a single-loop output voltage control, an inverter current feedback term to improve transient response, and a load current feedforward term to prevent voltage distortion. The guideline for setting control gain is presented based on output filter parameters and digital time delay. The performance of the proposed algorithm is proven by experimental results through comparison with the conventional algorithm.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.1
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• pp.79-86
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• 2013

We describe a neural stimulator front-end with arbitrary stimulation waveform generator and adaptive supply regulator (ASR) for visual prosthesis. Each pixel circuit generates arbitrary current waveform with 5 bit programmable amplitude. The ASR provides the internal supply voltage regulated to the minimum required voltage for stimulation. The prototype is implemented in $0.35{\mu}m$ CMOS with HV option and occupies $2.94mm^2$ including I/Os.

• Journal of Biomedical Engineering Research
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• v.10 no.1
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• pp.53-58
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• 1989

An arbitrary waveform generator was developed for the experiment of electro-physiology and the electrical stimulator. This system has been constructed three parts. (1 ) Data input parts (2) Data processing and control parts (3) Analog signal output parts The system characteristics were as follows. (1) System based on Microprocessor (2) Input using Thumbwheel switch (3) Isolated output signal (4) System flexibility

• Biomedical Science Letters
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• v.14 no.1
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• pp.39-45
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• 2008

Inflammation is the complex biological response of injured tissues to harmful stimuli. A cascade of biochemical events propagates and matures the inflammatory response, involving the local vascular system, the immune system, and various cells within the injured tissue. The immune system is often involved with inflammatory disorders, demonstrated in both allergic reactions and some myopathies, with many immune system disorders resulting in abnormal inflammation. An Arbitrary Waveform Generator (AWG) is a piece of electronic test equipment used to generate electrical waveforms for the treatment of patients. The patients with gastritis and arthritis have been known to have a relatively favorable prognosis with AWG treatment. Accordingly, we examined the effects of AWG treatment in gastritis and arthritis animal model. The compound 48/80 was used to induce animal gastritis model. The tissue malone dialdehyde (MDA) and serum histamine levels, and the activity of superoxide dismutase (SOD) in stomach tissue were measured. The tissue MDA and serum histamine levels in AWG treated groups exhibited the decreased tendency compared with control group, whereas the tissue SOD activity was slightly increased. The Freund's complete adjuvant was used to induce animal arthritis model as well. The paw edema volume and the width of ankle joint were determined. The AWG treatment significantly decreased the paw edema volume after 5th day of treatment. Although further studies should be performed to confirm the effects of AWG treatment, present study suggest that AWG treatment might be used as a complementary treatment for the gastritis or arthritis treatment.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.429-440
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• 2007

A coded excitation has been studied to improve the performance for ultrasound imaging in term of SNR, imaging frame rate, contrast to tissue ratio, and so forth. However, it requires a complicated arbitrary waveform transmitter for each active channel that is typically composed of a multi-bit Digital-to-Analog Converter (DAC) and a linear power amplifier (LPA). Not only does the LPA increase the cost and size of a transmitter block, but it consumes much power, increasing the system complexity further and causing a heating-up problem. This paper proposes an optimized 1.5bit fourth order sigma-delta modulation technique applicable to design an efficient arbitrary waveform generator with greatly reduced power dissipation and hardware. The proposed SDM can provide a required SQNR with a low over-sampling ratio of 4. To this end, the loop coefficients are optimized to minimize the quantization noise power in signal band while maintaining system stability. In addition, the decision level for the 1.5 bit quantizer is optimized for a given input waveform, which results in the SQNR improvement of more than 5dB. Computer simulation results show that the SQNR of a FM(frequency modulated) signal generated by using the proposed method is about 26dB, and the peak side-lobe level (PSL) of its compressed waveform on receive is -48dB.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.228.1-228.1
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• 2012

Digital waveform generation technology for SAR payload can be divided into DDS(Direct Digital Synthesizer) method and Memory Mapped(M/M) method. DDS is the single chip which consists of the Sine Table, NCO(Numerically Controlled Oscillator), DAC, and so on. DDS method is a very simple method because the circuit configuration is not complex but has a disadvantage that can not control phase and amplitude easily by using NCO. M/M method has the complexity of the circuit configuration because it requires the memories which stores the waveforms, the control circuits, and DAC. And this method should apply the high interface technology for being compatible with the wide bandwidth of the digital signal and has the difficulty for PCB design because the number of the signal lines should be increased according to the number of the data bits for DAC. Although it has several disadvantages, this method has the capability of pre-distortion function which can compensate the phase and amplitude characteristics of the system and also has an excellent advantage to make any arbitrary waveform, so this method is considered as an important technology with DDS method. This research describes the technological trends of the waveform generator for the SAR payload and analyzes the characteristics of the technology.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.143-147
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• 2009

Inkjet printing makes use of ink droplets to form required patterns on a substrate. In order for the inkjet technology to produce reliable patterning tools, the jetting performance needs be controlled precisely. For controlling ink jetting performance, input waveform should be properly designed. In the past, the research was focused on designing dwell time of the input waveform for controlling jetting speed. However, the jetting performance is also closely related to rising and falling time. In this study, the effect of the rising and falling time on droplet speed will be investigated by measuring the droplet speed. In this study, the power OP amp (PA98A) was used in order to drive piezo inkjet head by amplifying the waveform generated from arbitrary function generator. The experimental results show that change of rising and falling time in the waveform not only affect the droplet speed but also optimal dwell time.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.9
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• pp.781-786
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• 2015

Recently, studies of 3D printing methods have been working in various applications. For example, the powder base method laminates the prints by using a binding or laser sintering method. However, the draw back of this method is that the post process is time consuming and does not allow for parts to be rapidly manufactured. The binding method requires the post process while the time required for the post process is longer than the manufacturing time. This paper proposes a UV curing binding method with an integrated piezo printing head system. The optimization of an arbitrary waveform generation for the control of a UV curable resin droplet was researched, in addition to developed optimized UV curing processes in multi nozzle ink jet heads.