• 제목/요약/키워드: Threshold Point

검색결과 507건 처리시간 0.029초

웨이브릿 임계치 잡음제거에 의한 파형의 변곡점 검출 (Detection of Inflection Point of Waveform by Wavelet Threshold Denoising)

  • 김태수
    • 한국정보통신학회논문지
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    • 제13권10호
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    • pp.2205-2210
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    • 2009
  • 본 논문에서 제안하는 잡음제거 방법은 hard 임계치 방법의 문제점을 개선한 제로점의 탄젠트 곡선 보간에 의한 잡음제거 기술이다. 자연계에서 관측되는 대기 전기변동량과 같은 신호의 시간적 변동량이나 가상현실을 이용하여 추출한사람의 빠른 움직임의 동작 곡선 등은 실제로 복잡하다. 따라서 이러한 신호의 관측파형에 대하여 변곡점에 대한 특징을 정확히 결정하는 것이 매우 중요하다. 특히 자연계의 측정 신호는 잡음이 포함되어 있어서 잡음을 제거하고 특징을 추출하는 것이 필요하다. 본 논문에서 제안한 새로운 방식에 의하여 잡음을 제거하고 변곡점을 추출하며 종래의 방식인 hard 임계치에 비하여 잡음지수가 5인 경우의 noise II 변곡점 신호에 대하여 SNR이 3.4dB 개선된 결과를 얻을 수 있음을 보였다.

근근막 발통점의 활성도에 따른 초음파 영상구조 및 전기생리학적 특성 (Ultrasound Imaging and Electrophysiological Characteristic According to Activity Levels of Myofascial Trigger Point)

  • 김현진;김수현;박영현;오석;최지호;김태열
    • 대한임상전기생리학회지
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    • 제8권1호
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    • pp.23-29
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    • 2010
  • Purpose : This study is to offer clinical primary data that examines the change of imaging structure and the quantitative evaluation of muscle activity on myofascial trigger points. This study examines neuromuscular physiological characteristic by comparing the differences in physical findings, pressure pain threshold, imaging, and electrophysiological characteristics in latent and active myofascial trigger points muscle and normal muscle through the following experimental procedures. Methods : The participants for the study were thirty-three adults in their twenties. We divided three groups into normal, latent and active myofascial trigger points groups by physical findings. We analyzed the results of measured pressure pain, threshold for pain, ultrasound imaging perform for structure characteristic of muscle, surface EMG according to type of muscle contraction for function of muscle contraction. Results : Significant differences were indicated in pressure pain threshold (p<0.05). Significant differences were discovered in the ultrasound imaging analysis. There were increases in muscle Echogenicity white area index (p<0.001). There were significant differences that decrease in %MVIC (p<0.05), increase in MDF (p<0.05). Conclusion : From these results, active rnyotascial trigger points muscle showed quality deterioration on ultrasound imaging and decreased function of muscle contraction, increased motor unit action potential of II type fiber, and electrophysiologically. Imaging structure and neuromuscular physiological characteristic can be diagnostic and quantitative analytical techniques for myofascial pain syndrome and a primary factor that reflected in physical therapy intervention.

무선랜 환경에서 AP간 전력임계치값을 통한 호 처리 연구 (A Study of Call Admission Scheme using Power Strength Threshold value between APs in Wireless LAN Environments)

  • 임승철
    • 한국인터넷방송통신학회논문지
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    • 제15권3호
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    • pp.107-112
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    • 2015
  • 스마트폰과 많은 무선단말기들이 이동성의 특성상 AP간 이동하게 되어 무선단말들과 AP(Access Point)간 많은 호 절체가 이루어지게 된다. AP에서 각 무선단말기마다 처리되는 호 처리는 상대적으로 많은 무선트랙픽을 유발하여 무선대역의 효율적인 활용을 저해하는 요인이 되고 있다. 따라서 본 논문에서는 무선단말기와 AP간의 트래픽 발생요인이 되고 있는 AP간 호 절체 트래픽양을 줄이기 위해서 무선단말기에 수신되는 AP들의 전력세기임계치와 임계타이머를 사용하여 AP에서 효과적으로 무선트랙픽을 활용할 수 있는 방안을 제안하였다. 제안된 방식과 기존의 방식을 시뮬레이션을 통하여 AP에서 처리하는 무선트래픽 양이 개선되어 전체적으로 무선대역의 활용을 효율적으로 할 수 있었다.

거대 점 오염원의 플룸에 의한 시정 장애 효과 연구 (A Study on Visibility Impairment Impact of the Plume from a Vast Point Source)

  • 배주현;김유근
    • 한국대기환경학회지
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    • 제15권5호
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    • pp.599-611
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    • 1999
  • Now that the plume of point source was suspected to have strong impact on visibility impairment in Pusan, we evaluated visibility impairment impact of the pulme from Pusan Thermo Electric Power Plant in Pusan. Level-1 and-2 analyses were carried out using VISCREEN(Visual Impact Screen model). The emission rates for this Pusan Thermo Electric Power Plant was projected to be 116g/s of nitrogen oxides(as $NO_2$). The source fails the level-1 test with a Plume perceptibility(ΔE) of 30, nearly 15 times the screeing threshold. To characterize worstcase meteorological conditions for level-2 screening, we obtained meteorological data from Mar., 1996 to Feb., 1997 of Pusan Thermo Electric Power Plant. The source fails the level-2 test with a ΔE of 17, nearly 8.5 times the screening threshold. These analyses indicated that adverse visibility impairment could not be ruled out. Therefore a Level-3 analysis was performed using PLUVUE II(Plume Visibility model). As a result, maximum reduction of visual range for 0900LST in winter was 0.9%. Visual impact of the plume from vast point source was judged to be considerable in terms of background visibility of urban area.

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The immediate effects of 830-nm low-level laser therapy on the myofascial trigger point of the upper trapezius muscle in visual display terminal workers: A randomized, double-blind, clinical trial

  • Lee, Jung-Hoon;Lee, Sun-Min
    • International Journal of Contents
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    • 제7권2호
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    • pp.59-63
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    • 2011
  • The aim of our study was to evaluate the immediate effects of an 830-nm Aluminium gallium arsenide (GaAlAs) laser, by examining the changes, in pressure-pain threshold (PPT) and tenderness at 3 kg of the myofascial trigger point (MTrP) of the upper trapezius muscle in visual display terminal (VDT) workers in comparison with placebo treatment. Thirty VDT workers (13 males, 17 females) with complaints of upper trapezius muscle were recruited. All participants were given either active GaAlAs laser (830 nm wavelength, 450 mW, 9 J at point) or placebo GaAlAs laser, according to the double-blinded and placebo-controlled trial. Both active and placebo low-level laser therapy (LLLT) treatments showed no significant effect on PPT and tenderness at 3 kg. These results suggest that a higher dosage may be necessary to produce immediate effects when applying LLLT to the MTrP of relatively large muscles such as the upper trapezius muscle.

구강작열감증후군 환자에서 기울과 전중($CV_{17}$)압통의 상관성 - Algometer를 이용한 전중압통의 정량화 측면에서 - (Correlation between Qi-Stagnation and Pressure Pain Threshold on $CV_{17}$ (Danzhong : 膻中) in Burning Mouth Syndrome Patients - In the Perspective of Quantification of Pressure Pain Threshold on $CV_{17}$ by using Algometer -)

  • 강경;김진성;선종기;손지희;김주연;장승원;손지영;이현주;류봉하
    • 대한한방내과학회지
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    • 제33권4호
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    • pp.498-510
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    • 2012
  • Objectives : This study was designed to find out whether there is a correlation between qi-stagnation score and pressure pain threshold (PPT) on acupuncture point $CV_{17}$ in burning mouth syndrome (BMS) patients. Methods : Thirty BMS patients who newly visited Oral Disease Clinic at the Kyung Hee University Korean Medicine Hospital were surveyed. The subjects were evaluated on age, illness duration, sex, self-assessed severity of BMS, qi-stagnation score, and PPT on 3 acupuncture points ($CV_{17}$, Rt. $SP_9$, Lt. $SP_9$). Results : There was significant correlation between age and PPT on $CV_{17}$ (p=0.005). Therefore, partial correlation analysis with age as control variable was done, and the result showed significant correlation between qi-stagnation score and PPT on $CV_{17}$ (p=0.001). Qi-stagnation diagnostic point by PPT on $CV_{17}$ was suggested as 3.8056 $kg/cm^2$ based on the fact that diagnostic score is 28.50 in the qi-stagnation questionnaire. Furthermore, considering that PPT is effected by age, we could attain qi-stagnation diagnostic equation of PPT on $CV_{17}$, that is suggested as $0.047{\times}(age)+0.848kg/cm^2$. PPT of 3 acupuncture points ($CV_{17}$, Rt. $SP_9$, Lt. $SP_9$) was compared, and the result showed that PPT was significantly lower on $CV_{17}$ (w/Rt $SP_9$: p=0.022, w/Lt. $SP_9$: p=0.012). Also, significance and correlation coefficient with qi-stagnation were higher on $CV_{17}$ (p<0.001, r=-0.620) than Rt. $SP_9$ (p=0.023, r=-0.413) or Lt. $SP_9$ (p=0.014, r=-0.444). Conclusions : The result of this study suggested that PPT on $CV_{17}$, measured quantitatively by algometer, had a strong correlation with qi-stagnation score in BMS patients. Therefore, the study showed that $CV_{17}$ can be a useful acupuncture point in diagnosing qi-stagnation by measuring PPT in BMS patients.

$La_2O_3$가 첨가된 Pr계 ZnO 바리스터의 미세구조와 전기적 특성 (The Microstructure and Electrical Characteristics of Pr-Based ZnO Variators with $La_2O_3$Additives)

  • 남춘우;박춘현
    • 한국전기전자재료학회논문지
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    • 제11권11호
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    • pp.969-974
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    • 1998
  • The effects of $La_2O_3$on the microstructure and electrical characteristics of Pr-based ZnO varistors were investigated. The average grain size increased in the range of 21.9~56.3$\mu$ m with increasing $La_2O_3$additive content(0.0~2.0 mol%). La was, of course grain boundary, largely segregated at the nodal point. As $La_2O_3$additive content increases, threshold voltage and nonlinear coefficient decreased and leakage current increased. In particular, 2.0 mol% $La_2O_3$-added varistor exhibited low threshold voltage 17.0V/mm and nonlinear coefficient of about 6. Based on these results, this varistor can be said to be used as low-voltage varistor, if nonlinear coefficient is somewhat improved forward.

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광 스레쉬홀드 발생기를 이용한 스트림 암호 시스템 (Stream Cipher System using Opitical Threshold Generator)

  • 한종욱
    • 정보보호학회논문지
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    • 제7권1호
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    • pp.15-32
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    • 1997
  • 본 논문에서는 스트림 암호 시스템에서 사용이 되는 LFSR 을 이용한 이진 수열 발생기중 하나인 Threshold 발생기에 대한 광학적 구현 방법을 새로이 제안하였다. 광학적 구현을 위하여 LCD를 이용하므로서 LFSR 및 Mod 덧셈 연산을 위한 각 비트 값을 표현, 2차원 처리가 가능하게 하였다. Thredshold 발생기의 LFSR기능은 Shdow Casting 기법을 이용하여, 또한 XOR 연산 및 내적 계산을 위한 MOD덧셈 연산은 LCD 가 갖고 있는 편광 특성을 이용하여 광학적으로 구현하였다. 특히 본 논문에서는 Mod 2 덧셈 연산을 위한 새로운 광학적 구현 방법인 RSPM 을 제안하므로서 연산 결과 값 측정과 LCD 상의 데이타 값 표현 과정을 제외한 전 부분을 완전한 광학적 방법으로 처리가 가능하게 하였다. 본 논문에서 제안한 광 Threshold 암호 시스템은 기존의 전자적인 H/W 구현 방법에서 문제가 되어오던 Tapping Point의 개수에 대한 한계성을 극복할 수 있는 장점을 지니고 있으며, 또한 2차원 데이타인 영상용 암호화 시스템의 광학적 구현에 그 응용이 가능하다.

미세전류가 수부체성경혈점의 실험적 통증 역치에 미치는 영향 (Effect of Microcurrent Stimulation at Hand Somatic Acupuncture Points on Experimental Pain Threshold)

  • 조정선;전제균;박래준
    • The Journal of Korean Physical Therapy
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    • 제6권1호
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    • pp.85-93
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    • 1994
  • The purposes of this study were 1) to examine the effects of microcurrent electrical neuromuscular stimulation 2) to compare surface electrode with needle electrode at somatic acupuncture points on experimental pain threshold measured at the distal end of the radius 3) to determine the changes in effect over time. A total of sixty healthy adult male and female subjects were assigned randomly to one of two experimental group or to a control group. Group 1(n=20) received MENS(Microcurrent Electrical Neuromuscular Stimulation) with surface electrode. Group 2(n=20) received HENS with needle electrode. Group 3(n=20) received no MENS. It measured experimental pain threshold at the wrist on pretreatment, 0 min after treatment. 15 min after treatment, 30 min after treatment in two experimental group. The results were as follows: 1. Experimental pain thresholds were higher in males than females(P<0.01). 2. Only the experimental group exhibited a significant increased in pain threshold after MENS treatment(P<0.05). 3. Surface electrode group increased significant pain threshold 0 min, 15 min after treatment, but greatly decrease 30 min after treatment. 4. Needle electrode group increased significant pain threshold 0 min, 15 min after treatment, but decrease 30 min after treatment. The results suggest that MENS applied to appropriate somatic acupuncture point can increase pain threshold. Further research is needed to assess the effects of greatly variety intensity of MENS of pain sufferes.

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인공지능기법을 이용한 동적 이진화 지문인식 방법에 관한 연구 (A Study on the Dynamic Binary Fingerprint Recognition Method using Artificial Intelligence)

  • 강종윤;이주상;이재현;공석민;김동한;이상배
    • 한국지능시스템학회논문지
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    • 제13권1호
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    • pp.57-62
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    • 2003
  • 자동화 지문인식을 위한 과정에서 지문영상의 정보를 보존하면서 최적의 세선화와 특이점추출을 위한 중요한 부분은 이진화 과정이다. 이진화 과정은 그레이-스케일 레벨의 영상을 0과 255값으로 바꾸는 과정이다. 이 과정에서 적절한 기준레벨값(Threshold Value)을 설정해 주지 않으면 지문영상의 정보가 손실된다. 본 논문에서는 이진화 과정 부분에 인공지능 기법을 적용하여 입력되는 지문영상에서 실시간으로 기준레벨(Threshold)을 추출하는 방법을 제안한다. 실험결과 기존의 방법과 비교하여 좋은 성능을 보여주고 있음을 나타낸다