• 제목/요약/키워드: Threshold Point

검색결과 507건 처리시간 0.028초

Convergence Properties of a Adaptive Learning Algorithm Employing a Ramp Threshold Function (Ramp 임계 함수를 적용한 적응 학습 알고리즘의 수렴성)

  • 박소희;조제황
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 한국신호처리시스템학회 2000년도 하계종합학술대회논문집
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    • pp.121-124
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    • 2000
  • 적응 학습 알고리즘으로 가중치를 변화시키는 단층 신경망의 출력부에 Ramp 임계 함수를 적용하여 입력이 zero-mean Gaussian random vector인 경우 가중치의 stationary point를 구하고, 적응 학습 알고리즘을 유도한다.

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The Effect of Applying Various Tools to the Stiffness and Muscle Tone of Hamstring Muscles (다양한 도구의 적용이 뒤넙다리근의 뻣뻣함과 근 긴장도에 미치는 영향)

  • Hwang, Sunghyun;Kim, Taeho
    • Journal of The Korean Society of Integrative Medicine
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    • 제8권4호
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    • pp.223-230
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    • 2020
  • Purpose : The purpose of this study was to examine the effects of tools (i., extracorporeal shock wave therapy, massage gun, and foam roller) on range of motion, muscle tone and pain threshold among patients with hamstring stiffness. Methods : Fourteen participants with hamstrings stiffness were recruited. Interventions were performed 6 times, and each session was for 30 seconds using the three tools. The range of motion, muscle tone, and pain threshold were measured. The order of the use of the three tools was randomly determined. The foam roller was made to move from the bottom of the hip crease to the upper part of the back of the hamstring. Additionally, velocity 5 vibration stimulation was performed on the hamstring using a massage gun. Moreover, vibration stimulation was performed on the hamstring with extracorporeal shock wave therapy 5 minutes, 5 Hz, and 1,500 strokes. The flexibility of the posterior thigh muscle was based on maintaining the knee and hip joints in a 90 ° bend in the supine position. The joint angle of the knee was measured, when the knee was actively extended, at the maximum point where the posterior thigh muscle was stretched. The elasticity of the posterior thigh muscle was measured while the subject was prone and in a relaxed state without any force. Measurements were made at the muscle abdominal area of the semitendinosus muscle of the posterior femur, and the area to be measured was marked with a pen. The measurement of the tenderness threshold of the posterior femur was measured using a tenderness meter(Commander Algometer, J-Tech, USA). The force value at the point at which the pressure sensation change to pain was measured after applying vertical pressure to the posterior femur muscle, which was the halfway point between the ischial tuberosity and the popliteal surface of the subject lying on their stomach. Results : The extracorporeal shock wave therapy increased stiffness and, muscle tone, and caused changes in the pain threshold, whereas the other two tools had no effect on these indices. Conclusion : Extracorporeal shock wave therapy has important effects on range of motion and muscle stiffness and can be used in warmup protocols.

Effects of Scolopendrid Water-Alcohol Extract Injection Applied to the Acupuncture Point on the Neuropathic Pain in Rats (백서(白鼠)에서 오공약침(蜈蚣藥鍼)이 신경병증성(神經病症性) 통증(痛症)에 미치는 영향(影響))

  • Lee, Sam-Ro;Koo, Sung-Tae;Kim, Sung-Nam;Hwang, Woo-Jun;Lee, Geon-Mok;Cho, Nam-Geun;Lim, Kyu-Sang;Kim, Sung-Chul
    • Korean Journal of Acupuncture
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    • 제21권2호
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    • pp.47-67
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    • 2004
  • Objectives : In the present study, the effect of Scolopendrid Water-Alcohol Extract (SWAE) applied to acupuncture point BL23 (Shinsu) on the neuropathic pain was examined. A common source of persistent pain in humans is the neuropathic pain. Anti-convulsant drugs are used to treat the neuropathic pain. In the oriental medicine, Scolopendrid was used for long time to treat convulsant syndrome and back pain, etc. Methods : On the bases of the Scolopendrid clinical application, the effect of SWAE applied to the acupuncture point was tested in the rat model of neuropathic pain. Neuropathic pain was induced by tight ligation of L5 spinal nerve. When rats developed pain behaviors, One hundred microliter of SWAE was applied into the ipsilateral BL23 point at a dose of 10 mg/ml under enflurane anesthesia. The foot withdraw latency of the hind limb was measured for an indicator of pain level after each manipulation. Results : SWAE injection increased the mechanical threshold of the foot in the rat model of neuropathic pain significantly for the duration of 4h, suggesting a partial alleviation of pain. SWAE applied to BL23 point produced a significant improvement of mechanical sensitivity of the foot lasting for at least 4h. However, neither contralateral BL23 point, ST25 (Chonchu) point, nor LR3 (Taechung) point produce as much increase of mechanical sensitivity as ipsilateral BL23 point. And, this increase of mechanical sensitivity was dose-dependent. The improvement of mechanical threshold was interpreted as an analgesic effect. In addition, the analgesic effect of Scolopendrid 4 mg/kg injection is equivalent to that of gabapentin 50 mg/kg injection. The relations between SWAE-induced analgesia and endogenous nitric oxide(NO), inducible NO synthase (iNOS)/neuronal NO synthase (nNOS) were also examined. Results were turned out that both NO production and nNOS/iNOS protein expression which are increased by nerve injury were suppressed by SWAE injection applied to BL23 point. Conclusions : The data suggest 1) that SWAE produces a potent analgesic effect on the neuropathic pain model in the rat and 2) that SWAE-induced analgesia modulate endogenous NO through the suppression of nNOS/iNOS protein expression.

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Algorithm for Pairwise Collision Detection and Avoidace in 3-D (3차원 일대일 충돌 감지 및 회피 알리고리듬)

  • Kim, Kwang-Yeon;Park, Jung-Woo;Tahk, Min-Jea
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • 제36권10호
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    • pp.996-1002
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    • 2008
  • This paper presents the development of a real-time algorithm for collision detection, collision avoidance and guidance to way-point. Three-dimensional point-mass aircraft models are used. For collision detection, time of closest point of approach(CPA) and distance at CPA are compared to threshold values. For collision avoidance, optimal acceleration input which maximizes the terminal relative distance is calculated based on optimal control theory. For guidance to way-point, proportional navigation guidance, the well-known method, is used. Two scenarios of encounter situation are illustrated to validate performance of proposed algorithm.

A P-wave Detection Algorithm by Template Matching Method (템플레이트 매칭에 의한 심전도 신호의 P파 검출 알고리즘에 관한 연구)

  • Hong, Jae-Woo;Jeong, Hee-Kyo;Shin, Kun-Soo;Lee, Myoung-Ho
    • Proceedings of the KOSOMBE Conference
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    • 대한의용생체공학회 1990년도 춘계학술대회
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    • pp.21-24
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    • 1990
  • This paper presents a new algorithm for P-wave detection in the ECG signal, we get the peak, onset and offset point by using significant point extraction algorithm with 5-point derivative. To these set of extracted significant points, we apply amplitude and duration threshold criterion. we define the set of significant point meeting the criterion as P-wave candidate. Then P-wave candidate is classified through match-process with template. The template with maximum number or P-wave candidate is selected to be the P-wave.

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Computing Thresholds of Linguistic Saliency

  • Chung, Siaw-Fong;Ahrens, Kathleen;Cheng, Chung-Ping;Huang, Chu-Ren;Simon, Petr
    • Proceedings of the Korean Society for Language and Information Conference
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    • 한국언어정보학회 2007년도 정기학술대회
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    • pp.126-135
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    • 2007
  • We propose and test several computational methods to automatically determine possible saliency cut-off points in Sketch Engine (Kilgarriff and Tugwell, 2001). Sketch Engine currently displays collocations in descending importance, as well as according to grammatical relations. However, Sketch Engine does not provide suggestions for a cut-off point such that any items above this cut-off point may be considered significantly salient. This proposal suggests improvement to the present Sketch Engine interface by calculating three different cut-off point methods, so that the presentation of results can be made more meaningful to users. In addition, our findings also contribute to linguistic analyses based on empirical data.

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Comparisons of Object Recognition Performance with 3D Photon Counting & Gray Scale Images

  • Lee, Chung-Ghiu;Moon, In-Kyu
    • Journal of the Optical Society of Korea
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    • 제14권4호
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    • pp.388-394
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    • 2010
  • In this paper the object recognition performance of a photon counting integral imaging system is quantitatively compared with that of a conventional gray scale imaging system. For 3D imaging of objects with a small number of photons, the elemental image set of a 3D scene is obtained using the integral imaging set up. We assume that the elemental image detection follows a Poisson distribution. Computational geometrical ray back propagation algorithm and parametric maximum likelihood estimator are applied to the photon counting elemental image set in order to reconstruct the original 3D scene. To evaluate the photon counting object recognition performance, the normalized correlation peaks between the reconstructed 3D scenes are calculated for the varied and fixed total number of photons in the reconstructed sectional image changing the total number of image channels in the integral imaging system. It is quantitatively illustrated that the recognition performance of the photon counting integral imaging system can be similar to that of a conventional gray scale imaging system as the number of image viewing channels in the photon counting integral imaging (PCII) system is increased up to the threshold point. Also, we present experiments to find the threshold point on the total number of image channels in the PCII system which can guarantee a comparable recognition performance with a gray scale imaging system. To the best of our knowledge, this is the first report on comparisons of object recognition performance with 3D photon counting & gray scale images.

Pressure pain threshold and visual analogue scale changes in the high and low energy extracorporeal shock wave

  • Yang, You-Jin;Lee, Seung-Joon;Choi, Matthew
    • Physical Therapy Rehabilitation Science
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    • 제3권2호
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    • pp.142-147
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    • 2014
  • Objective: This study aims to investigate high energy and low energy extracorporeal shockwave therapy (ESWT) and which one is more effective for shoulder pain. Design: Single blind randomized controlled trial. Methods: Fifty two subjects with upper trapezius (UT) trigger point (TrP) participated in this study. They were allocated to high energy (n=26) and low energy group (n=26). This study applies ESWT and investigates the changes of pressure pain threshold (PPT) and visual analogue scale (VAS). The high and low energy groups received focused piezo electric type ESWT 4 Hz, 1,000 pulses and 0.351 and $0.092mJ/mm^2$ respectively. Outcome measures of PPT and pain was measured by algometer and pain VAS. These measurements were performed before and after treatment. Results: The PPT value was significantly increased in both groups after treatment (p<0.05) and VAS scores were significantly decreased after treatment in both groups (p<0.05). However, there were no significant differences between groups. Conclusions: ESWT is an effective treatment for the application of the UT TrP. Although there were significant effects of extracorporeal shock wave therapy on PPT and VAS scores, there were no signficant differences between high and low energy extracorporeal shock wave therapy.

Comparison of the effects of transcutaneous electrical nerve stimulation, low level laser, and placebo treatment on temporomandibular joint disorders: a single-blind randomized controlled trial

  • Kim, Hyunjoong
    • Physical Therapy Rehabilitation Science
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    • 제9권4호
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    • pp.244-251
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    • 2020
  • Objective: Physical therapy techniques are required for patients with temporomandibular joint disorder (TMD), but the effects of treatment have not been compared. Therefore, effects of transcutaneous electrical nerve stimulation (TENS) and low level laser (LLL), which are most commonly used interventions, were compared. Design: Randomized controlled trial. Methods: Thirty-six participants with pain in the temporomandibular joint were enrolled, and 12 participants were randomly assigned to either the TENS group, LLL group, or placebo group. Each intervention was performed for a total of 6 sessions for 2 weeks. For the evaluation of the participants, the mouth opening (MO), pressure pain threshold (PPT), and stress were measured at three time periods: baseline, post-test, and follow-up at 2 weeks. Results: Significant interaction between groups according to each evaluation point was found only in PPT-masseter (p<0.05). The evaluation time point at which a significant difference appeared was at the post-test and follow-up at 2 weeks time periods. As a result of the post-test, the LLL group showed a significant improvement compared to the TENS group (p<0.05), and at 2 weeks follow-up, the TENS group showed a significant improvement compared to the placebo group (p<0.05). Conclusions: In this study, an experiment was conducted to compare the treatment effects when TENS, LLL, and placebo were given to patients with TMD. In addition, by quantitatively presenting the effect size of each treatment, this study suggests clinical use of TENS and LLL treatment for TMD.

Segmented Douglas-Peucker Algorithm Based on the Node Importance

  • Wang, Xiaofei;Yang, Wei;Liu, Yan;Sun, Rui;Hu, Jun;Yang, Longcheng;Hou, Boyang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권4호
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    • pp.1562-1578
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    • 2020
  • Vector data compression algorithm can meet requirements of different levels and scales by reducing the data amount of vector graphics, so as to reduce the transmission, processing time and storage overhead of data. In view of the fact that large threshold leading to comparatively large error in Douglas-Peucker vector data compression algorithm, which has difficulty in maintaining the uncertainty of shape features and threshold selection, a segmented Douglas-Peucker algorithm based on node importance is proposed. Firstly, the algorithm uses the vertical chord ratio as the main feature to detect and extract the critical points with large contribution to the shape of the curve, so as to ensure its basic shape. Then, combined with the radial distance constraint, it selects the maximum point as the critical point, and introduces the threshold related to the scale to merge and adjust the critical points, so as to realize local feature extraction between two critical points to meet the requirements in accuracy. Finally, through a large number of different vector data sets, the improved algorithm is analyzed and evaluated from qualitative and quantitative aspects. Experimental results indicate that the improved vector data compression algorithm is better than Douglas-Peucker algorithm in shape retention, compression error, results simplification and time efficiency.