• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.482-485
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• 2016

In this work, a transcranial magnetic stimulation(TMS) experiment on animals is performed to stimulate the brain cortex of the mouse using modulated signals. The proposed TMS system is composed of the inverter, transformer, capacitor, variable inductor, and stimulation coil to generate 1.5 mT magnetic field in the brain cortex of the mouse. The stimulation signal is modulated to square wave where the carrier frequency is swept from 85 to 91 kHz to investigate the stimulation effect. The experimental result shows that when the carrier frequency of the stimulation signal is lower than 89 kHz, the reaction of the mouse does not change while the stimulation signal which has the carrier frequency higher than 89 kHz results in decreasing the threshold of the stimulus for the pressure.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.174-174
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• 2014

Memristor devices are one of the most promising candidate approaches to next-generation memory technologies. Memristive switching phenomena usually rely on repeated electrical resistive switching between non-volatile resistance states in an active material under the application of an electrical stimulus, such as a voltage or current. Recent reports have explored the use of variety of external operating parameters, such as the modulation of an applied magnetic field, temperature, or illumination conditions to activate changes in the memristive switching behaviors. Among these possible choices of signal controlling factors of memristor, photon is particularly attractive because photonic signals are not only easier to reach directly over long distances than electrical signal, but they also efficiently manage the interactions between logic devices without any signal interference. Furthermore, due to the inherent wave characteristics of photons, the facile manipulation of the light ray enables incident light angle controlled memristive switching. So that, in the tautological sense, device orienting position with regard to a photon source determines the occurrence of memristive switching as well. To demonstrate this position controlled memory device functionality, we have fabricated a metal-semiconductor-metal memristive switching nanodevice using ZnO nanorods. Superhydrophobicity employed in this memristor gives rise to illumination direction selectivity as an extra controlling parameter which is important feature in emerging. When light irradiates from a point source in water to the surface treated device, refraction of light ray takes place at the water/air interface because of the optical density differences in two media (water/air). When incident light travels through a higher refractive index medium (water; n=1.33) to lower one (air; n=1), a total reflection occurs for incidence angles over the critical value. Thus, when we watch the submerged NW arrays at the view angles over the critical angle, a mirror-like surface is observed due to the presence of air pocket layer. From this processes, the reversible switching characteristics were verified by modulating the light incident angle between the resistor and memristor.

• Journal of Sensor Science and Technology
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• v.10 no.6
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• pp.317-327
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• 2001

In this paper, we proposed a new detection method of pH image to effectively measure a 2-dimensional pH distribution of test materials by irradiating an frequency modulated light to LAPS using a reticle. It could measure simultaneously signals in one line by applying a modulated light having difference frequency for each pixel using a frequency modulating reticle, and calculating an amplitude with respect to a frequency component by the light source. To experiment the proposed method, we designed and implemented a reticle considering of a LAPS's characteristic, and reconstructed an image by frequency analysis using the implemented reticle and test pattern image. As a result, we verified that the proposed method using the reticle was able to detect 30 times faster for a $30{\times}30$ pixels pH image having a PSNR of 22-24 [dB] than conventional method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.5
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• pp.30-36
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• 2012

A new BIST(Built-In Self-Test) scheme to test ADC(Analog-to-Digital Converter) with a transition detector is proposed. The proposed BIST is able to replaces histogram method, the most popular approach in static testing of ADC. With a ramp signal as an input test stimulus, the proposed BIST calculates ADC's static parameters such as offset, gain, INL(Integral Non-Linearity) and DNL(Differential Non-Linearity). The three detectors in the proposed BIST can deal with a transient zone problem, a phenomenon due to random noise in real test environments and are cost efficient at various acceptable ranges determined as a test spec. The simulation results validate that our method performs accurate static test and show the reduction of the hardware overhead.

• The Korean Journal of Physiology
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• v.15 no.2
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• pp.73-81
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• 1981

Experiments were conducted in ischemic decerebrate cats to study the effects of electroacupuncture and electrical stimulation of peripheral nerve on pain reaction. Flexion reflex was used as an index of pain. The reflex was elicited by stimulating the sural nerve(20 V, 0.5 msec duration) and recorded as a compound action potential from the nerve innervated to the semitendinosus muscle. Electroacupuncture was performed, using a 23-gauge hyperdermic needle, on the tsusanli point in the lateral upper tibia of the ipsilateral hindlimb. The common peroneal nerve was selected as a peripheral nerve which may be associated with electroacupuncture action, as it runs through the tissue portion under the tsusanli point. Both for electroacupuncture and the stimulation of common peroneal nerve a stimulus of 20 V-intensity, 2 msec-duration and 2 Hz-frequency was applied for 60 min. The results are summerized as follows: 1) The electroacupuncture markedly depressed the flexion reflex; this effect was eliminated by systemic application of naloxone $(0.02{\sim}0.12\;mg/kg)$, a specific narcotic antagonist. 2) Similarly, the electrical stimulation of the common peroneal nerve significantly depressed the flexion reflex, the effect being reversed by naloxone. 3) When most of the afferent nerves excluding sural nerve in the ipsilateral hindlimb were cut, the effect of electroacupuncture on the flexion reflex was not observed. Whereas direct stimulation of the common peroneal nerve at the proximal end from the cut resulted in a significant reduction of the flexion reflex, again the effect was reversible by naloxone application. 4) Transection of the spinal cord at the thoracic 12 did not eliminate the effect of peripheral nerve stimulation on the flexion reflex and its reversal by naloxone, although the effect was significantly less than that in the animal with spinal cord intact. These results suggest that: 1) the analgesic effect of an electroacupuncture is directly mediated by the nervous system and involves morphine-like substances in CNS, 2) the site of analgesic action of electroacupuncture resides mainly in the brainstem and in part in the spinal cord.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.331-334
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• 2011

This is a study about a platform realization measuring the extent of reaction in nerve, as giving a electrical impulse on a nerve pulp regulating a function of muscle, about a measurement of nerve reaction in the amount of current, the lasting time of current, and the position of electrode from a electrical impuls.The position of an electrode in a electrical nerve impuls have nothing to do with all nerves from exercise to all things. There is the Single Twitch Stimulation(STS), Train-of-four(TOF), and Double Burst Stimulation(DBS) in the form of nerve stimulation. This report is needed for selecting MCU of low electric power for a base in embedded system and measuring the extent of reaction after making a sensor interface to know sensitivity of measuring sensor in basic reaction of nerve impuls. The platform is realized to select a high efficiency AD Convertor for raising accuracy in measured data. As the platform in this report was developed for a medical appliances, it was designed to consider user safety in electric power Isolation when making electric power circuit.

• Journal of Biomedical Engineering Research
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• v.42 no.3
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• pp.107-115
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• 2021

Purpose: The aim of this study is to find the location of acupoints that are effective for increasing parasympathetic nervous system(PNS) activity among acupoints used to relieve symptoms such as dizziness and nausea. Materials and Methods: Twenty healthy adult men participated in this experiment. Transcutaneous electrical nerve stimulation(TENS) was applied to P6(Neiguan), ST36(Zusanli) and BL20(Pishu) for 30 minutes. For 5 minutes before and after stimulation, Electrocardiogram(ECG), Electrodermal activity(EDA), Respiration, and Skin temperature(SKT) were measured using biosignalsplux Professional(biosignalsplux; Portugal). Paired t-test was performed for the results before and after stimulation, and a one-way ANOVA test between stimulations was performed for the rate of change before and after stimulation. Results: When each acupoint was stimulated with TENS, it was found that the PNS was generally activated. In addition, when considering the change in biosignals after stimulation, the participants stimulated with P6 showed the most consistent results. Conclusion: As a result of stimulating each acupoint, it was found that stimulating P6 can effectively increase PNS activity. These results indicate that methods of stimulating P6 may be most effective in alleviating symptoms of motion sickness.

• Korean Journal of Applied Biomechanics
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• v.33 no.1
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• pp.17-24
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• 2023

Objective: The purpose of this study was to investigate the effects of different frequency on of knee extensors muscle function during electrical muscle stimulation (EMS). Method: In this research, 40 subjects who have no musculoskeletal disorder, and less than a year workout experience were recruited in order to analyze effects of EMS with different stimulus frequency. Forty subjects were randomly divided into four groups of ten subjects in each group. A EMS training program with different frequencies (without EMS [WE], EMS with frequency 30 Hz [E30], EMS with frequency 60 Hz [E60], EMS with frequency 90 Hz [E90]) was assigned to each group. Throughout eight weeks of training, test subjects were simultaneously carried out knee extension exercises such as squat, leg extension, and leg-press while using EMS with different frequency (20 min, pulse width 250 ㎲, on-off ratio 1:1). Isokinetic knee extension strength, muscle activity of the rectus femoris (RF), the vastus medialis (VM), and the vastus lateralis (VL), and the median frequency of the RF, the VM, and the VL were collected and compared between pre and post training in order to find effects of applying EMS with different frequencies. For each dependent variable, a one-way ANOVA was to determine whether there were significant differences among four different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: When compared to WE and E90, E30 causes significant increase in isokinetic knee extension strength. No significant differences were found in EMG values across different EMS conditions. However, the median frequency of the VM in E30 was significantly increased than the corresponding value for WE. Conclusion: The results of this study showed that EMS training with 30 Hz frequency had positive effect on knee extensor. Based of the findings of the present study, EMS training with lower frequency may help the performer to focus on developing strength in knee extensor muscles.

• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.471-477
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• 1999

Many researches have been performed whether electrical stimulation could be used for diagnosis and treatment on the auditory system impairment. Unfortunately, there were no standard methods or theoretical background for choosing stimulus conditions because of the lack of understanding on the transmission of electrical stimulation through the auditory pathway. This research was conducted to observe the effect of electrical stimulation on the tinnitus-induced animals. Nine guniea pigs were used for the experment and divided into two groups, five animals for the experimental group(A) and four animals for the control group(B). Experimental conditions were divided into four steps, before tinnitus induction and 1, 6, 12 hours after tinnitus induction using salicylate based on the Jastreboff model. In each experimental condition, ABR and ECochG were obtained, and autocorrelation coefficients were calculated from normalized waveforms based on rms values. Sum of all the autocorrelation coefficients was extracted as a parameter to observe the changes between before and after the electrical stimulation. As a result, ABR parameter values were rapidly increased 6 hours after tinnitus induction, the gradually returned back to the initial state. On the other hand, when electrical stimulation was applied, parameter values did not change compared with the initial sate. Parameter values of ECochG showed that the effect of electrical stimulation appeared 12 hours after the tinnitus induction. It was concluded that an electrical stimulation to the tinnitus-induced model changes the correlation coefficients of ABR and ECochG waveforms.

• Annals of Clinical Neurophysiology
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• v.12 no.2
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• pp.35-46
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• 2010

Various electrophysiological tests have provided a large body of valuable information on neuronal responses to a presented stimulus. The special and general somatic sensory pathways are main targets of evoked potentials. Two types of evoked potentials, exogenous and endogenous, are commonly used. Exogenous evoked potentials of general and special somatic sensory systems will be reviewed. One of general somatic sensory functional pathways, proprioception, can be evaluated by general somatosensory evoked potentials with electrical stimulation on nerves. The special somatosensory functional pathways, including vision, and audition, can be evaluated by visual evoked potentials and auditory evoked potentials. Also laser-evoked potentials are newly developed for pain pathway, including lateral spinothalamic pathway, and vestibular myogenic evoked potentials for sacculocollic pathways. The evoked potentials of sensory system have maximal clinical utility in evaluating functional deficits along the sensory pathways. They are used for evaluating comatose patients, hysterical patients, premature infants, patients with suspected demyelinating diseases or neoplasms, and research. We discuss the neurophysiologic tests of sensory systems in views of practical points. The organized evaluation of sensory electrophysiologic tests can be helpful in detecting and estimating the abnormalities in neurological diseases.