• Title/Summary/Keyword: Threshold Function

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Fuzzy-based Threshold Controlling Method for ART1 Clustering in GPCR Classification (GPCR 분류에서 ART1 군집화를 위한 퍼지기반 임계값 제어 기법)

  • Cho, Kyu-Cheol;Ma, Yong-Beom;Lee, Jong-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.6
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    • pp.167-175
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    • 2007
  • Fuzzy logic is used to represent qualitative knowledge and provides interpretability to a controlling system model in bioinformatics. This paper focuses on a bioinformatics data classification which is an important bioinformatics application. This paper reviews the two traditional controlling system models The sequence-based threshold controller have problems of optimal range decision for threshold readjustment and long processing time for optimal threshold induction. And the binary-based threshold controller does not guarantee for early system stability in the GPCR data classification for optimal threshold induction. To solve these problems, we proposes a fuzzy-based threshold controller for ART1 clustering in GPCR classification. We implement the proposed method and measure processing time by changing an induction recognition success rate and a classification threshold value. And, we compares the proposed method with the sequence-based threshold controller and the binary-based threshold controller The fuzzy-based threshold controller continuously readjusts threshold values with membership function of the previous recognition success rate. The fuzzy-based threshold controller keeps system stability and improves classification system efficiency in GPCR classification.

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The effect of resistance inspiratory muscle training on respiratory function in stroke (저항성 들숨근 훈련이 뇌졸중 환자의 호흡기능에 미치는 영향)

  • Lee, So Yun;Han, Jin Tae
    • Journal of Korean Physical Therapy Science
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    • v.27 no.3
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    • pp.1-11
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    • 2020
  • Background: The purpose of this study was to investigated the effects of threshold resistance inspiratory muscle training on respiratory function in chronic stroke patients. Design: Randomized Controlled Trial Methods: Eighteen patient with stroke were randomly assigned to the experimental group (n=9) and control group (n=9) all testing and training. The experimental group underwent threshold resistance inspiratory muscle training with resistance adjusted of maximal inspiratory pressure, 60 breathing a day and general physical therapy 30 minutes a day, 5 times a week for 4 weeks. The control group was taken general respiratory muscle training and general physical therapy for 4 weeks in the same way. Respiratory function, walking ability were evaluated before and after the intervention. Statistical significance of the results were evaluated by ANCOVA between control group and experimental group after intervention. Results: There was a significant increase in FVC and FEV1 in the experimental group in pulmonary function tests (p<0.05). There was a significant difference with the maximum inspiratory pressure and the maximum inspiratory flow rate between experimental and control group (p<0.05). There was no significant difference with the maximum inspiratory capacity between experimental and control group (p>0.05) but the maximum inspiratory capacity of experimental group some increased than that of control group. Conclusion: These finding gave some indications that the threshold resistance inspiratory training may benefit on pulmonary function in people with stroke, and it is feasible to be included in rehabilitation interventions with this population.

Optimal Threshold Setting Method for R Wave Detection According to The Sampling Frequency of ECG Signals (심전도신호 샘플링 주파수에 따른 R파 검출 최적 문턱치 설정)

  • Cho, Ik-sung;Kwon, Hyeog-soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.7
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    • pp.1420-1428
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    • 2017
  • It is difficult to guarantee the reliability of the algorithm due to the difference of the sampling frequency among the various ECG databases used for the R wave detection in case of applying to different environments. In this study, we propose an optimal threshold setting method for R wave detection according to the sampling frequency of ECG signals. For this purpose, preprocessing process was performed using moving average and the squaring function based the derivative. The optimal value for the peak threshold was then detected according to the sampling frequency by changing the threshold value according to the variation of the signal and the previously detected peak value. The performance of R wave detection is evaluated by using 48 record of MIT-BIH arrhythmia database. When the optimal values of the differential section, window size, and threshold coefficient for the MIT-BIH sampling frequency of 360 Hz were 7, 8, and 6.6, respectively, the R wave detection rate was 99.758%.

Analysis of Threshold Voltage and DIBL Characteristics for Double Gate MOSFET Based on Scaling Theory (스켈링 이론에 따른 DGMOSFET의 문턱전압 및 DIBL 특성 분석)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.1
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    • pp.145-150
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    • 2013
  • This paper has presented the analysis for threshold voltage and drain induced barrier lowering among short channel effects occurred in subthreshold region for double gate(DG) MOSFET as next-generation devices, based on scaling theory. To obtain the analytical solution of Poisson's equation, Gaussian function has been used as carrier distribution to analyze closely for experimental results, and the threshold characteristics have been analyzed for device parameters such as channel thickness and doping concentration and projected range and standard projected deviation of Gaussian function. Since this potential model has been verified in the previous papers, we have used this model to analyze the threshold characteristics. As a result to apply scaling theory, we know the threshold voltage and drain induced barrier lowering are changed, and the deviation rate is changed for device parameters for DGMOSFET.

Discriminant analysis using empirical distribution function

  • Kim, Jae Young;Hong, Chong Sun
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.5
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    • pp.1179-1189
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    • 2017
  • In this study, we propose an alternative method for discriminant analysis using a multivariate empirical distribution function to express multivariate data as a simple one-dimensional statistic. This method turns to be the estimation process of the optimal threshold based on classification accuracy measures and an empirical distribution function of data composed of classes. This can also be visually represented on a two-dimensional plane and discussed with some measures in ROC curves, surfaces, and manifolds. In order to explore the usefulness of this method for discriminant analysis in the study, we conducted comparisons between the proposed method and the existing methods through simulations and illustrative examples. It is found that the proposed method may have better performances for some cases.

Nonlinear approach to modeling heteroscedasticity in transfer function analysis (시계열 전이함수분석 이분산성의 비선형 모형화)

  • 황선영;김순영;이성덕
    • The Korean Journal of Applied Statistics
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    • v.15 no.2
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    • pp.311-321
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    • 2002
  • Transfer function model(TFM) capturings conditional heteroscedastic pattern is introduced to analyze stochastic regression relationship between the two time series. Nonlinear ARCH concept is incorporated into the TFM via threshold ARCH and beta- ARCH models. Steps for statistical analysis of the proposed model are explained along the lines of the Box & Jenkins(1976, ch. 10). For illustration, dynamic analysis between KOSPI and NASDAQ is conducted from which it is seen that threshold ARCH performs the best.

Cumulative Impulse Response Functions for a Class of Threshold-Asymmetric GARCH Processes

  • Park, J.A.;Baek, J.S.;Hwang, S.Y.
    • Communications for Statistical Applications and Methods
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    • v.17 no.2
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    • pp.255-261
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    • 2010
  • A class of threshold-asymmetric GRACH(TGARCH, hereafter) models has been useful for explaining asymmetric volatilities in the field of financial time series. The cumulative impulse response function of a conditionally heteroscedastic time series often measures a degree of unstability in volatilities. In this article, a general form of the cumulative impulse response function of the TGARCH model is discussed. In particular, We present formula in their closed forms for the first two lower order models, viz., TGARCH(1, 1) and TGARCH(2, 2).

An effect of time gating threshold (TGT) on a delivered dose in internal organ with movement due to respiration (호흡에 의해 내부 움직임을 갖는 장기에 전달되는 선량에서 Time Gating Threshold(TGT)의 효과)

  • Kim, Yon-Lae;Chung, Jin-Bum;Suh, Tae-Suk
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2004.11a
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    • pp.132-135
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    • 2004
  • In this study, we investigated the effect of threshold on a delivered dose in organ with internal motion by respiration. With mathematic model for 3D dose calculation reported by Lujan et al., we had calculated the position of organ as a function of time in previous study. This result presented that the variation of organ is within 2 mm from initial exhale position to the organ position during operating 1 s. Gating threshold, in this study, is determined to the moving region of target during 1s at a primary position of exhale. This period of gating threshold is 50% of the duty cycle in a half breathing cycle which is period from the top position of exhalation to the bottom position of inhalation. Radiation fields were then delivered under three conditions; 1) existent of moving target in the region of threshold(1sec, 1.5sec), 2) existent of moving target out of the region of threshold, 3) non-moving target. The non-moving target delivery represents a dose different induced due to internal organ motion.

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Performance Analysis of Threshold-based Bernoulli Priority Jump Traffic Control Scheme (동적우선권제어함수 기반 TBPJ 트래픽 제어방식의 성능분석)

  • Kim, Do-Kyu
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.11S
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    • pp.3684-3693
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    • 2000
  • In this paper, performance of a nonblocking high speed packet switch with switching capacity m which adopts a dynamic priority control function (DPCF) of a threshold- based Bernoulli priority jump (TBPJ) scheme is considered. Each input queue has two separate buffers with different sizes for two classes of traffics, delay-sensitive and loss-sensitive traffics, and adopts a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Under the TBP] scheme, a head packet of the delay-sensitive traffic buffer goes into the loss -sensitive traffic buffer with Hernoulli probability p according to systems states that represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. In addition to, TBP] scheme shows better performance than that of HOL scheme.

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