• Title/Summary/Keyword: Multiple Threshold

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Investigation of Biases for Variance Components on Multiple Traits with Varying Number of Categories in Threshold Models Using Bayesian Inferences

  • Lee, D.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.7
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    • pp.925-931
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    • 2002
  • Gibbs sampling algorithms were implemented to the multi-trait threshold animal models with any combinations of multiple binary, ordered categorical, and linear traits and investigate the amount of bias on these models with two kinds of parameterization and algorithms for generating underlying liabilities. Statistical models which included additive genetic and residual effects as random and contemporary group effects as fixed were considered on the models using simulated data. The fully conditional posterior means of heritabilities and genetic (residual) correlations were calculated from 1,000 samples retained every 10th samples after 15,000 samples discarded as "burn-in" period. Under the models considered, several combinations of three traits with binary, multiple ordered categories, and continuous were analyzed. Five replicates were carried out. Estimates for heritabilities and genetic (residual) correlations as the posterior means were unbiased when underlying liabilities for a categorical trait were generated given by underlying liabilities of the other traits and threshold estimates were rescaled. Otherwise, when parameterizing threshold of zero and residual variance of one for binary traits, heritability estimates were inflated 7-10% upward. Genetic correlation estimates were biased upward if positively correlated and downward if negatively correlated when underling liabilities were generated without accounting for correlated traits on prior information. Residual correlation estimates were, consequently, much biased downward if positively correlated and upward if negatively correlated in that case. The more categorical trait had categories, the better mixing rate was shown.

Multiple-threshold asymmetric volatility models for financial time series (비대칭 금융 시계열을 위한 다중 임계점 변동성 모형)

  • Lee, Hyo Ryoung;Hwang, Sun Young
    • The Korean Journal of Applied Statistics
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    • v.35 no.3
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    • pp.347-356
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    • 2022
  • This article is concerned with asymmetric volatility models for financial time series. A generalization of standard single-threshold volatility model is discussed via multiple-threshold in which we specialize to twothreshold case for ease of presentation. An empirical illustration is made by analyzing S&P500 data from NYSE (New York Stock Exchange). For comparison measures between competing models, parametric bootstrap method is used to generate forecast distributions from which summary statistics of CP (Coverage Probability) and PE (Prediction Error) are obtained. It is demonstrated that our suggestion is useful in the field of asymmetric volatility analysis.

Fault Detection and Isolation using navigation performance-based Threshold for Redundant Inertial Sensors

  • Yang, Cheol-Kwan;Shim, Duk-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2576-2581
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    • 2003
  • We consider fault detection and isolation (FDI) problem for inertial navigation systems (INS) which use redundant inertial sensors and propose an FDI method using average of multiple parity vectors which reduce false alarm and wrong isolation, and improve correct isolation. We suggest optimal isolation threshold based on navigation performance, and suggest optimal sample number to obtain short detection time and to enhance detectability of faults little larger than threshold.

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Dose dependent effects of Jungsongouhyul Pharmacopuncture on Low Back Pain (요통환자에서 중성어혈 약침 사용 용량에 따른 효과)

  • Jeong, Man-Jin;Kwon, O-Gon;Woo, Chang-Hoon;An, Hee-Duk
    • Journal of Pharmacopuncture
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    • v.14 no.2
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    • pp.45-52
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    • 2011
  • Objectives : The object of this study is to analyse about Low Back Pain's intensity according to dosage of Jungsongouhyul pharmacopuncture. Method : Three groups were made with 15 patients in Po-Hang Oriental Hospital, which is affiliates to Daegu Haany University. They were observed August 1st, 2010 to September 30th. 2010. Each group was treated by based on acupuncture, herb and other therapy and differential dosage of Jungsongouhyul pharmacopuncture 0,4, 0.8, and 1.2cc. We had measured pain threshold and Visual Analog Scale during first week of their admission. The statistical analysis was performed by using the oneway ANOVA and Tukey's test. Result : Change of VAS was not statistically significant. Change of pain threshold was statistically significant. Multiple comparisons of pain threshold between the group1,2 was not statistically significant. Multiple comparisons of pain threshold between the group1,3 and group2,3 was statistically significant. Conclusions : Jungsongouhyul Pharmacopuncture 1.2cc was more effective than 0.4 and 0.8cc.

Alternative accuracy for multiple ROC analysis

  • Hong, Chong Sun;Wu, Zhi Qiang
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.6
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    • pp.1521-1530
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    • 2014
  • The ROC analysis is considered for multiple class diagnosis. There exist many criteria to find optimal thresholds and measure the accuracy of diagnostic tests for k dimensional ROC analysis. In this paper, we proposed a diagnostic accuracy measure called the correct classification simple rate, which is defined as the summation of true rates for each classification distribution and expressed as a function of summation of sequential true rates for two consecutive distributions. This measure does not weight accuracy across categories by the category prevalence and is comparable across populations for multiple class diagnosis. It is found that this accuracy measure does not only have a relationship with Kolmogorov - Smirnov statistics, but also can be represented as a linear function of some optimal threshold criteria. With these facts, the suggested measure could be applied to test for comparing multiple distributions.

CHAOTIC THRESHOLD ANALYSIS OF NONLINEAR VEHICLE SUSPENSION BY USING A NUMERICAL INTEGRAL METHOD

  • Zhuang, D.;Yu, F.;Lin, Y.
    • International Journal of Automotive Technology
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    • v.8 no.1
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    • pp.33-38
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    • 2007
  • Since it is difficult to analytically express the Melnikov function when a dynamic system possesses multiple saddle fixed points with homoclinic and/or heteroclinic orbits, this paper investigates a vehicle model with nonlinear suspension spring and hysteretic damping element, which exhibits multiple heteroclinic orbits in the unperturbed system. First, an algorithm for Melnikov integrals is developed based on the Melnikov method. And then the amplitude threshold of road excitation at the onset of chaos is determined. By numerical simulation, the existence of chaos in the present system is verified via time history curves, phase portrait plots and $Poincar{\acute{e}}$ maps. Finally, in order to further identify the chaotic motion of the nonlinear system, the maximal Lyapunov exponent is also adopted. The results indicate that the numerical method of estimating chaotic threshold is an effective one to complicated vehicle systems.

Preventive Adaption Threshold Mechanism in Buffer Allocation for Shared Memory Buffer (공유 메모리 버퍼에서의 예방적 적응 한계치 버퍼 할당 기법)

  • Shin, Tae-Ho;Lee, Sung-Chang;Lee, Hyeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.10
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    • pp.24-33
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    • 2001
  • Delay, delay variation and packet loss rate are principal QoS(Quality of Service) elements of packet communication. This paper proposes a new buffer allocation mechanism to improve the packet loss performance in such a situation that multiple logical buffers share a single physical memory buffer. In the proposed buffer allocation mechanism, the movement of dynamic threshold follows a curved track instead of a straight line which is used in the DT(dynamic threshold) mechanism. In order evaluate the effectiveness of the proposed mechanism, it is compared with the existing previously proposed mechanisms in several aspects including NC(no control), ST(Static Threshold) and DT mechanisms.

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Near ML Decoding Based on Metric-First Searching and Branch Length Threshold for Multiple Input Multiple Output Systems (여러 입력 여러 출력 시스템에서 길이 먼저 살펴보기와 가지 길이 문턱값을 바탕으로 둔 준최적 복호)

  • An, Tae-Hun;Kang, Hyun-Gu;Oh, Jong-Ho;Song, Iick-Ho;Yoon, Seok-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.8C
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    • pp.830-839
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    • 2009
  • In this paper, we address a near maximum likelihood (ML) scheme for the decoding of multiple input multiple output systems. Based on the metric-first search method and by employing Schnorr-Euchner enumeration and branch length thresholds, the proposed scheme provides reduced computational complexity. The proposed scheme is shown by simulation to have lower computational complexity than other near ML decoders while maintaining the bit error rate close to the ML performance.

Development of Gate Structure in Junctionless Double Gate Field Effect Transistors (이중게이트 구조의 Junctionless FET 의 성능 개선에 대한 연구)

  • Cho, Il Hwan;Seo, Dongsun
    • Journal of IKEEE
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    • v.19 no.4
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    • pp.514-519
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    • 2015
  • We propose the multiple gate structure of double gate junctionless metal oxide silicon field oxide transistor (JL MOSFET) for device optimization. Since different workfunction within multiple metal gates, electric potential nearby source and drain region is modulated in accordance with metal gate length. On current, off current and threshold voltage are influenced with gate structure and make possible to meet some device specification. Through the device simulation work, performance optimization of double gate JL MOSFETs are introduced and investigated.

A Robust Background Subtraction Algorithm for Dynamic Scenes based on Multiple Interval Pixel Sampling (다중 구간 샘플링에 기반한 동적 배경 영상에 강건한 배경 제거 알고리즘)

  • Lee, Haeng-Ki;Choi, Young Kyu
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.2
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    • pp.31-36
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    • 2020
  • Most of the background subtraction algorithms show good performance in static scenes. In the case of dynamic scenes, they frequently cause false alarm to "temporal clutter", a repetitive motion within a certain area. In this paper, we propose a robust technique for the multiple interval pixel sampling (MIS) algorithm to handle highly dynamic scenes. An adaptive threshold scheme is used to suppress false alarms in low-confidence regions. We also utilize multiple background models in the foreground segmentation process to handle repetitive background movements. Experimental results revealed that our approach works well in handling various temporal clutters.