• 제목/요약/키워드: threshold effect

검색결과 1,510건 처리시간 0.032초

신문 반응점에 적용한 외이 경피신경전기자극이 압통각 및 촉각역치에 미치는 영향 (Effects on Pressure Pain and Tactile Threshold by Auricular TENS at Shenmen Point)

  • 정대인
    • 대한임상전기생리학회지
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    • 제2권1호
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    • pp.59-70
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    • 2004
  • The purpose of this study were to determine the changes between pre, during, intermed, post of each two groups of 16 persons and to compare the effect of transcutaneous electrical nerve stimulation(TENS) at shenmen of auricular point on experimental pressure pain and tactile threshold measured at both ulnar styloid process and medial malleoli. Sixteen healthy adult men and women, aged 20 to 28 years, were assigned randomly to eight of one groups. Control group received TENS to exception of auricular point. Experimental group received TENS to shenmen of auricular point. Experimental pressure pain and tactile pain threshold at the both ulnar styloid process and medial malleoli was determined with algometer and von frey filament before 10 minute, during 10 minute, intermediate and post 30 min of treatment. In pressure pain and tactile threshold showed a statistically significant increase(p<0.05) ipsilateral and contralateral of treatment group. These results suggest that TENS at shenmen of auricular point has the capability to higher pressure pain and tactile threshold in whole body.

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외이에 대한 경피신경 전기자극과 레이저가 실험적 피부 통증역치에 미치는 영향 (Effects of Transcutaneous Electrical Nerve Stimulation and Laser at Auricular Points on Experimental Cutaneous Pain Threshold)

  • 심연주;이미선;이윤주
    • 한국전문물리치료학회지
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    • 제4권1호
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    • pp.87-94
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    • 1997
  • The purposes of this study were 1) to determine the changes between pre-treatment and post-treatment of four groups of 15 persons each and 2) to compare the effect of conventional transcutaneous electrical nerve stimulation(TENS) and laser at auricular acupuncture points on experimental pain threshold measured at the wrist. Sixty healthy adult men and women(M:32, F:28), aged 20 to 28 years, were assigned randomly to one of four groups. Group 1 received TENS to the appropriate auricular point for wrist pain, Group 2 received laser to the appropriate auricular point for wrist pain, Group 3 received placebo TENS to the appropriate auricular point for wrist pain, Group 4 received no treatment and served as controls. Experimental pain threshold at the wrist was determined with a painful electrical stimulus before and 20 minutes after ear stimulation. Group 1 was the only group that showed a stastically significant increase (p<0.05) in pain threshold after treatment whereas the Group 2,3 and 4 did not. These results suggest that TENS has the capability to higher pain threshold but laser does not.

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40대 이상 성인의 구강환경요인(타액분비량, 미각인지역치)이 구강건강영향지수(OHIP-14)에 미치는 영향 (Effect of oral environment(salivary flow, taste recognition threshold) of adults over 40 years on oral health influence point(OHIP-14))

  • 김지화;김기욱
    • 한국치위생학회지
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    • 제13권5호
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    • pp.749-757
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    • 2013
  • Objectives : The aim of the study is to investigate the relationship between salivary flow, palate recognition threshold, DMFT index and oral health influence point (OHIP-14) of the adults over 40 years old. Methods : Salivary flow and taste recognition threshold were measured in 220 adults over 40 years old from three dental clinics in Daegu from January 3 to February 4, 2012. A total of 208 questionnaires were analyzed. Results : The adults recognized the sour taste in low concentration level when the salivary flow was faster. DMFT index was low in those who recognized sweet and sour taste that affected OHIP-14. Conclusions : Tooth decaying food must be restricted because of its high acidity in the past despite the individuals' taste recognition threshold was neglected. Before the diet control, it is necessary to measure the taste threshold of the individuals. Training for improving salivary flow is very important to prevent dental caries and to preserve good taste.

하단게이트 전압에 따른 비대칭 이중게이트 MOSFET의 문턱전압이동 의존성 (Bottom Gate Voltage Dependent Threshold Voltage Roll-off of Asymmetric Double Gate MOSFET)

  • 정학기
    • 한국정보통신학회논문지
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    • 제18권6호
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    • pp.1422-1428
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    • 2014
  • 본 연구에서는 비대칭 이중게이트(double gate; DG) MOSFET의 하단 게이트전압에 대한 문턱전압이동 현상에 대하여 분석하였다. 비대칭 DGMOSFET는 4단자소자로서 상단과 하단의 게이트단자에 별도의 전압을 인가할 수 있으므로 하단게이트전압의 변화가 문턱전압에 영향을 미칠 것이다. 그러므로 단채널효과로 알려져 있는 문턱전압 이동현상이 하단게이트전압에 의하여 감소할 수 있는지를 관찰하고자 한다. 이를 위하여 문턱전압이하영역에서의 차단전류모델을 제시하였으며 차단전류가 채널폭 당 $10^{-7}A/{\mu}m$일 경우의 상단게이트 전압을 문턱전압으로 정의하여 채널길이 및 채널두께의 변화에 따라 하단게이트 전압의 변화에 대한 문턱전압의 이동현상을 관찰하였다. 결과적으로 하단게이트전압은 문턱전압이동현상에 커다란 영향을 미치는 것을 알 수 있었으며, 특히 단채널효과가 심각하게 발생하고 있는 채널길이 및 채널두께 영역에서는 더욱 큰 영향을 미치고 있다는 것을 알 수 있었다.

흰쥐의 술 후 통증 모델에서 T형 칼슘 통로 차단제인 Ethosuximide와 Mibefradil의 항통각과민 효과 (Antihyperalgesic Effects of Ethosuximide and Mibefradil, T-type Voltage Activated Calcium Channel Blockers, in a Rat Model of Postoperative Pain)

  • 신혜란;차영덕;한정욱;윤정원;김부성;송장호
    • The Korean Journal of Pain
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    • 제20권2호
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    • pp.92-99
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    • 2007
  • Background: A correlation between a T-type voltage activated calcium channel (VACC) and pain mechanism has not yet been established. The purpose of this study is to find out the effect of ethosuximide and mibefradil, representative selective T-type VACC blockers on postoperative pain using an incisional pain model of rats. Methods: After performing a plantar incision, rats were stabilized on plastic mesh for 2 hours. Then, the rats were injected with ethosuximide or mibefradil, intraperitoneally and intrathecally. The level of withdrawal threshold to the von Frey filament near the incision site was determined and the dose response curves were obtained. Results: After an intraperitoneal ethosuximide or mibefradil injection, the dose-response curve showed a dose-dependent increase of the threshold in a withdrawal reaction. After an intrathecal injection of ethosuximide, the threshold of a withdrawal reaction to mechanical stimulation increased and the increase was dose-dependent. After an intrathecal injection of mibefradil, no change occurred in either the threshold of a withdrawal reaction to mechanical stimulation or a dose-response curve. Conclusions: The T-type VACC blockers in a rat model of postoperative pain showed the antihyperalgesic effect. This effect might be due to blockade of T-type VACC, which was distributed in the peripheral nociceptors or at the supraspinal level. Further studies of the effect of T-type VACC on a pain transmission mechanism at the spinal cord level would be needed.

IDENTIFICATION CODE OF INTERSTELLAR CLOUDS WITHIN IRAF

  • Lee, Young-Ung;Jung, Jae-Hoon;Kim, Hyun-Goo
    • 천문학논총
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    • 제12권1호
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    • pp.185-196
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    • 1997
  • We present a code which identifies individual clouds in crowded region using IMFORT interface within Image Reduction and Analysis Facility (IRAF). We define a cloud as an object composed of all pixels in longitude, latitude, and velocity that are simply connected and that lie above some threshold temperature. The code searches the whole pixels of the data cube in efficient way to isolate individual clouds. Along with identification of clouds it is designed to estimate their mean values of longitudes, latitudes, and velocities. In addition, a function of generating individual images (or cube data) of identified clouds is added up. We also present identified individual clouds using a $^{12}CO$ survey data cube of Galactic Anticenter Region (Lee et al. 1997) as a test example. We used a threshold temperature of $5\sigma$ rms noise level of the data With a higher threshold temperature, we isolated subclouds of a huge cloud identified originally. As the most important parameter to identify clouds is the threshold value, its effect to the size and velocity dispersion is discussed rigorously.

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Threshold burnup for recrystallization and model for rim porosity in the high burnup $UO_2$ fuel

  • Lee, Byung-Ho;Koo, Yang-Hyun;Sohn, Dong-Seong
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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    • pp.279-284
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    • 1998
  • Applicability of the threshold burnup for rim formation was investigated as a function of temperature by Rest's model. The threshold burnup was the lowest in the intermediate temperature region, while on the other temperature regions the threshold burnup is higher. The rim porosity was predicted by the van der Waals equation based of the rim pore radius of 0.75${\mu}{\textrm}{m}$ and the overpressurization model on rim pores. The calculated centerline temperature is in good agreement with the measured temperature. However, more efforts seem to be necessary for the mechanistic model of the rim effect including rim growth with the fuel burnup.

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Improved Single-Tone Frequency Estimation by Averaging and Weighted Linear Prediction

  • So, Hing Cheung;Liu, Hongqing
    • ETRI Journal
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    • 제33권1호
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    • pp.27-31
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    • 2011
  • This paper addresses estimating the frequency of a cisoid in the presence of white Gaussian noise, which has numerous applications in communications, radar, sonar, and instrumentation and measurement. Due to the nonlinear nature of the frequency estimation problem, there is threshold effect, that is, large error estimates or outliers will occur at sufficiently low signal-to-noise ratio (SNR) conditions. Utilizing the ideas of averaging to increase SNR and weighted linear prediction, an optimal frequency estimator with smaller threshold SNR is developed. Computer simulations are included to compare its mean square error performance with that of the maximum likelihood (ML) estimator, improved weighted phase averager, generalized weighted linear predictor, and single weighted sample correlator as well as Cramer-Rao lower bound. In particular, with smaller computational requirement, the proposed estimator can achieve the same threshold and estimation performance of the ML method.

Threshold Voltage Properties of OFET with CuPc Active Material

  • Lee, Ho-Shik;Kim, Seong-Geol
    • Journal of information and communication convergence engineering
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    • 제13권4호
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    • pp.257-263
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    • 2015
  • In this study, organic field-effect transistors (OFETs) using a copper phthalocyanine (CuPc) material as an active layer and SiO2 as a gate insulator were fabricated with varying active layer thicknesses and channel lengths. Further, using a thermal evaporation method in a high-vacuum system, we fabricated a CuPc FET device of the top-contact type and used Au materials for the source and drain electrodes. In order to discuss the channel formation and FET characteristics, we observed the typical current-voltage characteristics and calculated the threshold voltage of the CuPc FET device. We also found that the capacitance reached approximately 97 pF at a negative applied voltage and increased upon the accumulation of carriers at the interface of the metal and the CuPc material. We observed the typical behavior of a FET when used as an n-channel FET. Moreover, we calculated the threshold voltage to be about 15-20 V at VDS = -80 V.

Formation of Dual Threshold in a Vertical Alignment Liquid Crystal Device

  • Choi, Sun-Wook;Jin, Huilian;Kim, Ki-Han;Lee, Ji-Hoon;Kim, Hoon;Shin, Ki-Chul;Kim, Hee Seop;Yoon, Tae-Hoon
    • Journal of the Optical Society of Korea
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    • 제16권2호
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    • pp.170-173
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    • 2012
  • We present a method that enables dual threshold voltages in a vertical alignment liquid crystal device, through which the gamma shift can be reduced with no subsequent decrease in the contrast ratio. By forming polymer layers, the threshold voltage shift is accomplished through the utilization of the voltage drop effect. We expect that the proposed method can be applied to the conventional 4-domain mode in order to achieve an 8-domain mode without the need for complex driving schemes.