• The Journal of Korean Physical Therapy
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• v.9 no.1
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• pp.103-115
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• 1997

The purpose of this study was to examine the amount of $\beta-endorphin$ and pain threshold according to time sequences in applying experimented TENS and MENS(pre treatment, posttreatment, 25 minutes after the treatment). This test was to aim at showing the effects of the experimental $\beta-endorphin$ and pain threshold applied to the randomly selected twenty healthy men in their twenties. The subjects were divided into two group(ten for TENS and the other ten MENS). The results obtained are as follows : 1. There was no significant difference in the $\beta-endorphin$ between TENS and HENS(p>0.05). There was no difference in the pain threshold at pretreatment and posttreatment(p>0.05), but there was some difference at 25 minutes after the treatment(p<0.05). 2. The group of TENS in the experimental $\beta-endorphin$ had the highest level of $14.40{\pm}3.098$ at posttreatment, but the level decreased a little according to time passed. And in the experimental pain threshold, the level went to the highest plateau of $2.92{\pm}0.483$ at 25 minutes after the treatment. 3. The group of MENS in the experimental $\beta-endorphin$ had the highest plateau of $14.20{\pm}3.967$ at posttreatment, but the level decreased a bit according to time passed also. And in the experimental pain threshold, the level went to the highest plateau of $2.49{\pm}0.617$ posttreatment. 4. There were some differences of the experimental $\beta-endorphin$ in TENS group at pretreatment and posttreatment(p<0.05). There were some differences in the experimental pain threshold between pretreatment and posttreatment as well as between pretreatment and 25 minutes after the treatment(p<0.05) MENS did not influence the experimental $\beta-endorphin$ and pain threshold. This experiment showed that TENS increased the levels of the experimental $\beta-endorphin$ at posttreatment and increased the levels of the experimental pain threshold untill 25 minutes after the treatment. Therefore, the time of sustaining pain in TENS group was longer than that of MENS group. Also, MENS showed that it increased each level of the experimental $\beta-endorphin$ and pain threshold, but these levels were not statistically meaningful.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.48-57
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• 1999

Applications of thresholding technique are based on the assumption that object and background pixels in a digital image can be distinguished by their gray level values. For the segmentation of more complex images, it is necessary to resort to multiple threshold selection techniques. This paper describes a new method for multiple threshold selection of gray level images which are not clearly distinguishable from the background. The proposed method consists of three main stages. In the first stage, a probability distribution function for a gray level histogram of an image is derived. Cluster points are defined according to the probability distribution function. In the second stage, fuzzy partition matrix of the probability distribution function is generated through the fuzzy clustering process. Finally, elements of the fuzzy partition matrix are classified as clusters according to gray level values by using max-membership method. Boundary values of classified clusters are selected as multiple threshold. In order to verify the performance of the developed algorithm, automatic inspection process of ball grid array is presented.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.361-366
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• 2009

We propose the performance enhancing method optimization of an asynchronous 2.5 Gbps/1.25 Gbps optical subscriber network with inverse RZ (Return to Zero) coded downstream and NRZ (Non Return to Zero) upstream re-modulation by adjusting threshold level control of a receiver. We theoretically analyze the BER (Bit Error Rate) performance by modeling the occurrence of BER by simulation with MATLAB according to the types of downstream data. The results have shown that the normalized threshold level in an optical receiver could be saturated at 1/3 as the SNR (Signal to Noise Ratio) increases. The needed SNR for obtaining the BER $10^{-9}$ can be reduced by $\sim$5 dB by optimizing the normalized threshold level at 1/3 instead of by using the conventional receiver with threshold level of 0.5. The proposed system can be a useful technology for asynchronous optical access networks with asymmetric upstream and downstream data rates, because the improved minimum receiving power could replace a light source with a source with lower power and lower cost in an OLT (Optical Line Termination).

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.287-299
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• 2013

The objective of this study is to derive and evaluate the drought threshold level based on hydro-meteorological data using historical drought events. After collecting the drought events during 1991 to 2009 year, the observed meteorological data and estimated hydrological component from LSM are used as input for the percentile analysis that is drought analysis data. The drought threshold level that precipitation and runoff of 3 month duration are less than 35%, soil moisture of 2 month duration is less than 35% and evapotranspiration of 3 month duration is more than 65% is derived using ROC analysis that are objective test method. ROC analysis with SPI (3) is performed to evaluate the applicability of threshold level in the domestic. As a result, it can be concluded that the derived drought threshold level show better performance to reflect the historical drought events than SPI (3) and it reasonably explain the spatial drought situation through the spatial analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.809-814
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• 2012

We propose an adaptive threshold detector algorithm for multi-level holographic data storage based on the expectation-maximization (EM) method. In this paper, the signal intensities that are passed through the four-level holographic channel are modeled as a four Gaussian mixture with unknown DC offsets and the threshold levels are estimated based on the maximum likelihood criterion. We compare the bit error rate (BER) performance of the proposed algorithm with the non-adaptive threshold detection algorithm for various levels of DC offset and misalignments. Our proposed algorithm shows consistently acceptable performance when the DC offset variance is fixed or the misalignments are lower than 20%. When the DC offset varies with each page, the BER of the proposed method is acceptable when the misalignments are lower than 10% and DC offset variance is 0.001.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.7-11
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• 2020

Enormous methods have been proposed for the detection and segmentation of blur and non-blur regions of the images. Due to the limited available information about the blur type, scenario and the level of blurriness, detection and segmentation is a challenging task. Hence, the performance of the blur measure operators is an essential factor and needs improvement to attain perfection. In this paper, we propose an effective blur measure based on the local binary pattern (LBP) with the adaptive threshold for blur detection. The sharpness metric developed based on LBP uses a fixed threshold irrespective of the blur type and level which may not be suitable for images with large variations in imaging conditions and blur type and level. Contradictory, the proposed measure uses an adaptive threshold for each image based on the image and the blur properties to generate an improved sharpness metric. The adaptive threshold is computed based on the model learned through the support vector machine (SVM). The performance of the proposed method is evaluated using a well-known dataset and compared with five state-of-the-art methods. The comparative analysis reveals that the proposed method performs significantly better qualitatively and quantitatively against all the methods.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.161-173
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• 2020

This study examines the nonlinear relationship between financial development and economic growth in Pakistan using the threshold regression model for the period 1980-2017. We also employed quantile regression with 0.25, 0.50, and 0.75 quantiles of conditional distribution. The quantile regression is based on minimizing of sum of squared residuals. The result indicates that economic growth responds positively to financial development when the level of financial development surpasses the threshold value of 0.151. However, when financial development lies below the threshold value (that is, 0.151), its impact on economic growth is negative. Thus, when financial development of Pakistan surpasses the threshold level, it contributes more towards economic growth since greater level of financial development contributes more to boosts economic growth. This finding reveals that economic growth reacts differently to financial development, and the relationship between financial development and economic growth is U-shaped in Pakistan. Among the other variables, physical capital, labor force, and government expenditure exert a positive effect on economic growth. Furthermore, inflation rate and trade openness have an insignificant impact on economic growth. The results of quantile regression also confirm the non-linear relationship between financial development and economic growth in Pakistan. The finding of this study suggests revamping of financial sector policies in Pakistan.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.9-13
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• 1994

The Heat Anisotropic Diffusion Method has shown very effective for the contour detection of 2-D echocardiogram. To implement this algorithm, we have to choose the parameter C, K, and the threshold level. The choice of C and K are not very sensitive for the good edge detection of the echocardiogram, however the choice of the threshold level is very critical. Until now the threshold level is chosen by the trial and error method. In this paper, we present an automatic threshold decision method from the histogram of the gradient of boundary-like pixels.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1679-1685
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• 1989

In this paper, a new design of GaAs level converter is proposed, and anlyzed wth the variation of the threshold voltage of E/D MESFETs. The threshold voltage ranges analyzed are -0.05V to 0.35V for enhancement type MESFETs and -0.3V to -0.7V for depletion type MESFETs. In this range, the variation of the input characteristics of the conventional level converter designed to convert the level of DCFL using Vss of -0.8V to that of -0.2V, is greather than 600mV, but of the level converter proposed here is less than 100mV.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.214-217
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• 2013

In this paper, we proposed an automatic threshold control method for radar warning receiver. Considering the noise level of the environment, this technique can effectively adjust sensitivity level of radar warning receiver and can offer more accurate radar information for aircraft pilot in noisy circumstances.