• Title/Summary/Keyword: Threshold effect

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Denoising Algorithm using Wavelet (웨이브렛을 이용한 잡음 제거 알고리즘)

  • 배상범;김남호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.8
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    • pp.1139-1145
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    • 2002
  • Wavelet transformed data can filter signal with each frequency band, because it includes detail information about original signal. Therefore, in this paper, important two noises were removed by wavelet. About AWGN environment UDWT(undecimated discrete wavelet transform), applying hard-threshold, was used and about impulse noise environment, it can be possible to recognize edge of original signal as well as superior denoising effect by using two methods, denoising by threshold and slope of signal by wavelet. SNR was used as a judgemental criterion of a denoising effect and Blocks and DTMF(dual tone multi frequency) were used as a test signal.

A study on the threshold Voltage Model for Short-channel EIGFET (Short-Channel EIGFET의 Threshold 전압 모델에 관한 연구)

  • Park, Gwang-Min;Kim, Hong-Bae;Gwak, Gye-Dal
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.4
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    • pp.1-7
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    • 1985
  • In this paper, a more improved threshold voltage model dependent on drain voltage and substrate bias for short - channel enhancement - mode IGFET is presented. Especially, compared with the several recently published models, the error is sufficiently reduced with the precise analysis on the correction factor for short-channel effect and the calculated values using this model are also agreed well with the experimental data about 1$\mu$m - channel length device.

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Effects of GaAsAl Laser on the Pressure Pain Threshold in Rats (GaAsAl 레이저 자극이 흰쥐의 압통역치에 미치는 영향)

  • Song, Young-Wha;Lee, Young-Gu;Lim, Jong-Soo
    • Journal of Korean Physical Therapy Science
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    • v.7 no.2
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    • pp.533-543
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    • 2000
  • This study was designed to evaluate the analgesic effect of low power GaAsAl laser on the pain threshold of mechanical stimulation using different treatment points, acupuncture point (zusanli) and non-acupuncture points(back). Furthermore, we investigated the analgesic effect of low power GaAsAl laser using the different duration and intensity of laser in mechanical stimulation induced pain behavior. The results were summarized as follows: 1. The threshold of mechanical stimulation was significantly increased by GaAsAl laser stimulation into zusanli point after 15 and 30 min after laser stimulation(P<05). However, the laser stimulation into non-acupoint did not affect the pain threshold of mechanical stimulation. with dose dependent manner. 2. In order to investigate the analgesic effects of BV depending upon different intensities of laser stimulation, the experimental animals were divided into three groups: 3 mW treated group, 6 mW treated group and 10 mW treated group. The low power GaAsAl laser stimulation was applied into zusanli acupoint for 30 min with different intensity of laser stimulation. Six and ten mW of laser stimulation significantly increased the pain threshold of mechanical stimulation at 15 min after laser stimulation as compared to that of control group(P<.05). Moreover, the analgesic effect of 10 mW laser stimulation was maintained for 30 min after laser stimulation (P<.05). 3. Finally, we tested the analgesic effect of 10 mW laser stimulation using different duration such as 10 min, 30 min or 1 hr after application of mechanical stimulation. In 30 min treatment group, the pain threshold of mechanical stimulation was increased at 15min and 30min after laser stimulation(P<.05). However, laser stimulation for 60 min dramatically increased the pain threshold of mechanical stimulation at 0 min after laser stimulation and the analgesic effect of laser stimulation was observed until 1 hr after laser stimulation. In conclusion, these data apparently demonstrate that low power GaAsAl laser has analgesic effect on mechanical induced pain model in rats. In addition, the treated point, intensity and duration of laser stimulation should be concerned before clinical application for pain management purpose.

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Effect of Inspiratory Muscle Training with Elastic Taping on Forced vital capacity and Sway Area in Stroke Patients

  • Park, Shin Jun
    • The Journal of Korean Physical Therapy
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    • v.32 no.2
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    • pp.121-125
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    • 2020
  • Purpose: The purpose of this study was to evaluate the forced vital capacity and sway area of respiratory muscles taping with threshold inspiratory muscles training for 1 week. Methods: Nineteen stroke patients were divided into two groups: experimental group (respiratory muscles taping with threshold inspiratory muscles training, n=10) and control group (threshold inspiratory muscles training, n=9). Forced vital capacity tests were performed using a spirometer. The instrument records the forced vital capacity (FVC). COP excursion test was performed using Zebris. The instrument records the sway area. All tests were measured before and after intervention. Results: The experimental group and control group showed significant increase in FVC (p<0.05). The sway area showed a significant decrease only in the experimental group (p<0.05). The FVC and sway area was no significant difference between the two groups (p>0.05). Conclusion: Threshold inspiratory muscles training is an effective intervention for improving FVC. Threshold inspiratory muscles training with respiratory taping is an effective intervention for improving FVC and sway area. Threshold inspiratory muscles training with respiratory taping can improve balance ability.

The Effect of Laser Geometry and Material Parameters on the Single Mode Gain Difference in Quarter Wavelength Shifted DFB Laser above Threshold Current (문턱전류이상에서 구조 및 재료 변수들이 $\lambda$/4위상천이 DFB 레이저의 단일모드 이득차에 미치는 영향)

  • 이홍석;김홍국;김부균;이병호
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.3
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    • pp.75-84
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    • 1999
  • Systematic studies for the effect of the linewidth enhancement factor, the confinement factor, the internal loss and the cavity length on the single mode gain difference and the frequency detuning are performed for $\lambda$/4 phase shifted DFB lasers above threshold. The above threshold characteristics are mainly determined by the linewidth enhancement factor, not by the confinement factor or the parameter defined by the product of the linewidth enhancement factor and the confinement factor. The normalized internal loss defined by the product of the internal loss and the cavity length mainly determines the above threshold characteristics compared to that of the internal loss or the cavity length alone. The effect of the cavity length on threshold characteristics is larger than that of the internal loss in the case of the same normalized internal loss. The above threshold characteristics of quantum well lasers are more resistant to the variations of the confinement factor and the normalized internal loss than those of bulk lasers due to the small linewidth enhancement factor.

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Shelter Effect of Porous Fences on the Saltation of Sand Particles in an Atmospheric Boundary Layer (방풍펜스가 후방에 놓인 야적모래입자의 비산에 미치는 영향에 관한 연구)

  • Park, Ki-Chul;Lee, Sang-Joon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.9
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    • pp.1175-1184
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    • 2000
  • Effects of porous wind fences on the wind erosion of particles from a triangular sand pile were investigated experimentally. The porous fence and sand pile were installed in a simulated atmospheric boundary layer. The mean velocity and turbulent intensity profiles measured at the sand pile location were well fitted to the atmospheric boundary layer over the open terrain. Flow visualization was carried out to investigate the motion of windblown sand particles qualitatively. In addition, the threshold velocity were measured using a light sensitive video camera with varying the particle size, fence porosity $\varepsilon$ and the height of sand pile. As a result, various types of particle motion were observed according to the fence porosity. The porous wind fence having porosity $\varepsilon$=30% was revealed to have the maximum threshold velocity, indicating good shelter effect for abating windblown dust particles. With increasing the sand particle diamter, the threshold velocity was also increased. When the height of sand pile is lower than the fence height, threshold velocity is enhanced.

Change characteristic of basin topographical parameters according to the threshold area of minimum order stream (최소차 하천의 임계면적에 따른 유역 지형매개변수의 변화특성)

  • Ahn Seung-Seop;Park Ro-Sam;Kim Jong-Ho;Lim Ki-Seok;Song Si-Hoon
    • Journal of Environmental Science International
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    • v.14 no.1
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    • pp.33-40
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    • 2005
  • The size of minimum order stream has a very sensitive effect on runoff analysis model using the divergence characteristic of stream. Therefore, in this study, the threshold area of minimum order stream has been examined the change characteristic of topographical parameters. The subject basin of the research was the upper basin of the Kumho water gage station which is located in the middle of the Kumho river. The 1:25,000 numerical geography which was constructed $10{\times}10m$ mesh was used. The range of investigation of topographical parameters are number of stream order, length, area, slope, basin relief, sinuosity ratio, drainage density and total stream length etc. It was found from the result of analysis that the threshold value of minimum order stream has a very big effect on topographical parameters of basin. It was found that the threshold area of minimum ord er stream revealed under $0.10km^{2}.$ Furthermore, the parameters showed a serious change except for over $0.10km^{2}.$

The Effect of Electroacupuncture on Pain Threshold and 5.Hydroxytryptamine Synthesis Induced by Nociception in the Raphe Magnus Nucleus of Dog Brain Stem (개의 발에 염증 유발 후 전침이 통증역치 및 뇌줄기 큰솔기핵의 5-Hydroxytryptamine 합성에 미치는 효과)

  • Cho, Mi-Suk
    • The Journal of Korean Physical Therapy
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    • v.23 no.1
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    • pp.59-66
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    • 2011
  • Purpose: The purpose of this study was to investigate the effect of electroacupuncture on pain threshold and 5-HT synthesis in raphe magnus nucleus of dog brain stem following nociception induced by 1% carageenan. Method: Twenty male dogs were randomly divided into two groups, a control group and an electroacupuncture group with the following parameters: ST36, LI11 and SP9 with 120Hz and 0.5mA. The dogs were sacrificed at 30, 60, 90, 120, 150 and 180 min after nociception using 1% carageenan injection into the plantar side of the dog's left leg. The pain threshold was recorded by an Analgesia-meter. After making brain slice sections, the tissues were immunostained with 5-HT antisera (1:2,500). Results: The pain threshold for the electroacupuncture group was higher than for the control group. The number of 5-HT immunoreactive neurons in the electroacupuncture group was greater than that of the control group. Differences between the two groups regarding the number of 5-HT immunoreactive neurons at 30 min and 60 min (p<0.05), at 120 min and 150 min (p<0.01), and at 8 days (p<0.05) were significant. Conclusion: The increases in pain threshold and number of 5-HT immunoreactive neurons in the raphe magnus nucleus of dog brain stem showed that electroacupuncture can attenuate pain transduction through the descending tract.

Effect of Threshold on the Comparison of Radar and Rain Gauge Rain Rate (레이더 강우와 지상강우 비교에 대한 임계값의 영향 평가)

  • Yoon, Jungsoo;Ha, Eunho;Yoo, Chulsang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.522-522
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    • 2015
  • In this study, the effect of threshold applied to the radar rain rate on the comparison of the radar and rain gauge rain rate was theoretically examined. The result derived was also evaluated theoretically, using the Bernoulli random field, and empirically, using Mt. Kwanak weather radar data. The results are summarized as follows. (1) In the application to the Bernoulli random field, it was found that the comparison of the radar and rain gauge rain rate with threshold does not introduce any systematic bias. (2) The same results could also be derived in the application to Mt Kwanak weather radar data. In all cases with several radar bin sizes and thresholds considered, the bias was estimated to be far less than 10% of the mean of the rain gauge rain rate. (3) However, in the comparison with threshold applied to both the radar and rain gauge rain rate, the bias was estimated to be higher than 20%. That is, the systematic bias was introduced. This result indicates that the comparison with threshold applied to both the radar and rain gauge rain rate should not be used.

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Methodology of Mapping Quantitative Trait Loci for Binary Traits in a Half-sib Design Using Maximum Likelihood

  • Yin, Zongjun;Zhang, Qin;Zhang, Jigang;Ding, Xiangdong;Wang, Chunkao
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.12
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    • pp.1669-1674
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    • 2005
  • Maximum likelihood methodology was applied to analyze the efficiency and statistical power of interval mapping by using a threshold model. The factors that affect QTL detection efficiency (e.g. QTL effect, heritability and incidence of categories) were simulated in our study. Daughter design with multiple families was applied, and the size of segregating population is 500. The results showed that the threshold model has a great advantage in parameters estimation and power of QTL mapping, and has nice efficiency and accuracy for discrete traits. In addition, the accuracy and power of QTL mapping depended on the effect of putative quantitative trait loci, the value of heritability and incidence directly. With the increase of QTL effect, heritability and incidence of categories, the accuracy and power of QTL mapping improved correspondingly.