• 한국게임학회 논문지
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• 제20권1호
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• pp.13-22
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• 2020

본 연구는 가상 물체의 무게감을 사용자에게 전달하여 몰입감 있는 가상현실 경험을 제공하는 컨트롤러에 관한 것이다. 무게감 전달의 수단으로 컨트롤러 내 무게 중심의 위치를 변화시키면 모멘트의 크기가 변화하는 개념을 활용하였다. 사용자가 무게차를 인지하는 무게 중심의 최소이동거리를 알아보기 위해 무게 중심의 위치를 변경할 수 있는 실험 장치를 제작하여 실험을 수행하였다. 그 결과, 시작 자극의 위치와 무관하게 약 5cm의 무게부 거리 차에서 두 물체 간의 무게 차이를 인지하는 것으로 나타났다. 향후 이러한 실험 결과를 반영하여 모멘트 변화에 따른 무게 인지의 최소이동거리 역치 값을 찾는 실험을 수행할 것이다.

• Journal of Photoscience
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• 제11권3호
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• pp.89-94
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• 2004

Motile cyanobacterium Synechocystis sp. PCC 6803 cells show photomovement with respect to the light stimulus. Under lateral irradiation, Synechocystis displays a phototactic gliding movement toward the light source by a twodimensional random biased walk. Under vertical irradiation, Synechocystis decreased the frequency of mean vectorial gliding speed dependent on the applied fluence rate, whereas the deviation distribution width of the speed increased. This strongly suggests the involvement of photokinesis. Evidence for the cyanobacterial photokinesis was discussed in the previous report (Choi et al., 1999. Photochem. Photobiol. 70, 95-102) demonstrating that the gross scalar speed of vertically irradiating cells increased by about 50% compared with that of dark-adapted cells. In the visible wavelength range, Synechocystis cells showed a maximal photokinetic activity at 420 nm and a second maximal activity at 680 nm. The threshold action spectrum for the photokinesis resembles the absorption spectrum of chlorophyll with major differences in the phototaxis action spectrum at 560 nm and 660 nm. We postulate that the cyanobacterial photokinesis is powered by the energy-generating chlorophyll pigments.

• The Korean Journal of Pain
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• 제13권1호
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• pp.8-18
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• 2000

Background: Intraperitoneal (IP) and intrathecal (IT) administration of $\alpha$-amino-3-hydroxy-5-methyl-4-isoxazole-propionic (AMPA) and kainate (KA) receptor antagonist attenuate hyperalgesia in various models of persistent pain. The purpose of this study was to assess the effects of IP and IT LY293558, a novel AMPA/KA receptor antagonist on mechanical hyperalgesia after incision. Methods: Sprague-Dawley rats were anesthetized with halothane and underwent plantar incision. Two hours later, responses to mechanical stimuli were assessed using the response frequency to a nonpunctate mechanical stimulus and withdrawal threshold to calibrated von Frey filaments. One group of rats received vehicle, 5 or 10 mg/kg of LY293558 IP. In the other group, vehicle, 0.2, 0.5 or 2 nmol of LY293558 was administered IT. Ataxia and motor function were also evaluated. Results: Hyperalgesia was persistent in both the vehicle and 5 mg/kg group. IP administration of 10 mg/kg of LY293558 increased withdrawal threshold at 30 and 60 min after incision; deficits in rotorod performance were observed at 30, 60, 90 and 150 min. IT administration of 0.5 nmol of LY293558 increased the median withdrawal threshold at 30 and 60 min. Motor function was only impaired at 30 min. IT administration of 2 nmol produced hemiparesis. Again, inhibition of pain behaviors outlasted the effects on motor function. Conclusions: These data further suggest AMPA/KA receptors are important for the maintenance of pain behaviors caused by incisions. IT administration of LY293558 was more effective than systemic administration and reducing pain behaviors caused by a surgical incision.

• The Korean Journal of Pain
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• 제23권3호
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• pp.172-178
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• 2010

Background: Tumor necrosis factor-alpha and other proinflammatory cytokines are becoming well recognized as key mediators in the pathogenesis of many types of neuropathic pain. Thalidomide has profound immunomodulatory actions in addition to their originally intended pharmacological actions. There has been debate on the analgesic efficacy of opioids in neuropathic pain. The aim of this study was to investigate the effect of thalidomide and morphine on a spinal nerve ligation model in rats. Methods: Male Sprague-Dawley rats weighing 100-120 g were used. Lumbar (L) 5 and 6 spinal nerve ligations were performed to induce neuropathic pain. For assessment of mechanical allodynia, mechanical stimulus using von Frey filament was applied to the paw to measure withdrawal threshold. The effects of intraperitoneal thalidomide (6.25, 12.5, 25 and 50 mg/kg, respectively) and morphine (3 and 10 mg/kg, respectively) were examined on a withdrawal threshold evoked by spinal nerve ligation. Results: After L5 and 6 spinal nerve ligation, paw withdrawal thresholds on the ipsilateral side were significantly decreased compared with pre-operative baseline and with those in the sham-operated group. Intraperitoneal thalidomide and morphine significantly increased the paw withdrawal threshold compared to controls and produced dose-responsiveness. Conclusions: Systemic thalidomide and morphine have antiallodynic effect on neuropathic pain induced by spinal nerve ligation in rat. These results suggest that morphine and thalidomide may be alternative therapeutic approaches for neuropathic pain.

• 한국콘텐츠학회논문지
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• 제19권10호
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• pp.198-205
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• 2019

본 연구의 목적은 목 디스크 환자에게 기계적 자극을 적용하여 피부 감각의 변화를 유도하고 동일한 척수분절의 통증 역치와 근 긴장도 전-후 변화를 확인하고자 하였다. 이에 목 디스크 질환을 가지고 있는 남성 10명, 여성 20명으로 구성된 대상자를 총 30명 선정하고 실험을 진행하였다. 기계적 자극 그룹은 Graston 장비를 이용하여 5분간 피부 감각 변화를 유도하였고, 대조군은 아무런 조치를 받지 않았다. 피부 감각 변화는 Von Frey filament를 통해 검사를 진행하였고, 압통 역치의 변화는 압통 역치 측정기를 통해 측정하였고, 근 긴장도의 변화는 Myotone pro를 사용하여 측정하였다. 기계적 자극 적용 시 피부 감각의 역치는 통계적으로 유의하게 증가하였다(p<0.05). 동일한 척수 분절의 신경 지배를 받는 오른쪽 가시아래근의 압통 역치와 근 긴장도는 통계적으로 유의하게 증가하였고(p<0.05), 오른쪽 등세모근의 압통 역치는 통계적으로 유의하게 감소하였다(p<0.05). 하지만 다른 근육들의 압통 역치와 근 긴장도는 통계적으로 유의한 변화가 나타나지 않았다. 또한, 대조군에서는 피부 감각, 압통 역치, 근 긴장도의 변화가 통계적으로 유의하게 나타나지 않았다. 결과적으로 기계적 자극에 의해 유도된 피부 감각 변화는 동일 척수 분절의 압통 역치와 근 긴장도의 변화시켰다. 따라서 동일 척수 분절에 대한 기계적 자극의 적용을 통해 목 디스크 환자의 압통 역치, 근 긴장도의 증가와 통증 조절을 위한 새로운 재활 방법으로 임상적 의의가 있다고 판단된다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.121-123
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• 1995

This paper presents a new method which compensates loss of loudness for digital hearing aids. Loudness grows more rapidly in frequency domain with substantial shifts of hearing threshold, so that loud sounds reach the uncomfortable sound level (UCL) at about the same physical stimulus level as with normal hearing. The result is a compression of the available dynamic range of hearing. Many techniques have been developed to compensate for hearing losses. In this paper, we propose a digital hearing aid which uses a single digital filter for reducing distortion and the fuzzy function to calculate gain factors. This function describes how much gain is needed for every frequency to restore loudness perception of a normal ear.

• 제어로봇시스템학회논문지
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• 제11권11호
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• pp.943-949
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• 2005

For the psychophysical experiment of tactile perception of shapes, experimental system consists of vibrator, tactile stimulation array, measurement and control system is designed and prepared. The psychophysical experiment for the tactile perception of shape is carried out by the estimation of the subject group. Through the experiment the threshold of tactile perception to multi-stimuli with some line shape is obtained. Also the appropriate tactile stimulus intensity and frequency of the tactile stimulation array to recognize arbitrary shapes effectively are derived and discussed.

• 한국임상수의학회지
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• 제15권2호
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• pp.410-416
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• 1998

These experiments were designed to evaluate the possibility of brain-stem auditory evoked responses(BAER) as a diagnostic tool for deafness in dogs. The BAER was recorded from three different groups of dogs; the normal dogs,'dog with otitis externa and dogs with unilateral destruction of cochlear. BAER of the normal dogs was consisted of distinct five peaks(I, II, III-IV, V). Furthermore, the clear shapes of waveform were observed at 85 dB. The latency of BAER was increased with reducing the intensity of sound-stimulus. The highest threshold of BAER was measured at 2 KHz with 10-30 dB. Dog with otitis externs demonstrated unclear shapes of BAER compared to the that of normal dogs. In the dogs with unilateral destruction of cochlear, the flat and indistinct waveform of BAER was recorded from the cochlear destroyed ear while that of BAER from normal side of ears did not show any differences from the normal BAER. These results indicate that the BAER can be clinically used in order to diagnose the deafness in dogs.

• The Korean Journal of Pain
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• 제13권2호
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• pp.175-181
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• 2000

Background: Pain is often measured using psychophysical scaling techniques. However, all of these methods found their limits, since they were based on the subjective sensations reported by the subjects. It is, therefore, desirable to validate psychophysical pain measures by simultaneously measuring some physiological correlate of nociception. We studied an objective method for measuring pain in human volunteer using R(III) nociceptive flexion reflex. Methods: Four different intensity of electrical stimuli between perception and 1.4 times the R(III) nociceptive flexion threshold were delivered to the sole of the feet in 8 normal volunteers. We measured the flexion reflex activity in the skin over the ipsilateral tibialis anterior muscle and subjects rated each stimulus on a visual analog scale (VAS) Results: Both R(III) nociceptive flexion reflex activity and VAS ratings showed a linear relationship with stimulus intensity and with each other in all volunteers. Conclusions: R(III) nociceptive flexion reflex elicited through electrical stimulation may used as an objective pain measurement, previsionary based on our study paradigm.

• Journal of Acupuncture Research
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• 제21권6호
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• pp.167-176
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• 2004

Objective : This study was designed to investigate the effects of electro-acupuncture(EA) and moxibustion at CV13, CV12, CV10 and ST36 serum gastin level in rats. Methods : The present study was conducted to see the effects produced by combined electro-acupuncture(EA) and moxibustion using four different acupoints on serum gastrin level in rats. Electro-acupuncture (2 Hz, intensity ; 10 times muscle twitch threshold) was applied for 30 minutes to ST36 under halothane anesthesia. Moxibustion ($1.6{\pm}0.3mg$, 5 times of a day) was applied during 3 days to CV13, CV12, CV10 under halothane anesthesia. Results : Both of EA applied to the ST 36 and Moxibustion applied to the CV10, CV12 decreased serum gastrin level significantly. And the effect of combined EA at ST36 and moxibustion at CV10 was shown stronger effect than each singular stimulus of EA at ST36 and moxibustion at CV10. These data suggest that both of EA and moxibustion at specific acupoints produce change of serum gastrin level in rats and combined EA and moxibustion was shown quite effect than each singular stimulus.