• Title/Summary/Keyword: Stopping rule

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Two-Stage Maximum Tolerated Dose Estimation by Stopping Rule in a Phase I Clinical Trial (제1상 임상시험에서 Stopping Rule을 이용한 두 단계 MTD 추정법)

  • Lee, Na-Mi;Kim, Dong-Jae
    • Communications for Statistical Applications and Methods
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    • v.19 no.1
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    • pp.57-64
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    • 2012
  • Phase I clinical trials determine the maximum tolerated dose(MTD) of a new drug. In this paper, we proposed a two-stage MTD estimation method by a Stopping rule in a phase I clinical trial. The suggested MTD estimation method is compared to the standard design(SM3) and the continual reassessment method(CRM) using a Monte Carlo simulation study.

An Effective Stopping Rule for Software Reliability Testing

  • Yoon, Bok-Sik
    • International Journal of Reliability and Applications
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    • v.3 no.2
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    • pp.81-90
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    • 2002
  • The importance of the reliability of software is growing more and more as more complicated digital computer systems are used for real-time control applications. To provide more reliable software, the testing period should be long enough, but not unnecessarily too long. In this study, we suggest a simple but effective stopping rule which can provide just proper amount of testing time. We take unique features of software into consideration and adopt non-homogeneous Poisson process model and Bayesian approach. A numerical example is given to demonstrate the validity of our stopping rule.

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Efficient Methods for Reducing Clock Cycles in VHDL Model Verification (VHDL 모델 검증의 효율적인 시간단축 방법)

  • Kim, Kang-Chul
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.12
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    • pp.39-45
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    • 2003
  • Design verification of VHDL models is getting difficult and has become a critical and time-consuming process in hardware design. Recent]y the methods using Bayesian estimation and stopping rule have been introduced to verify behavioral models and to reduce clock cycles. This paper presents two strategies to reduce clock cycles when using stopping rule in a VHDL model verification. The first method is that a semi-random variable is defined and the data that stay in the range of semi-random variable are skipped when stopping rule is running. The second one is to keep the old values of parameters when phases of stopping rule are changed. 12 VHDL models are examined to observe the effectiveness of strategies, and the simulation results show that more than about 25% of clock cycles is reduced by using the two proposed strategies with 0.6% losses of branch coverage rate.

A Bayesian Diagnostic Measure and Stopping Rule for Detecting Influential Observations in Discriminant Analysis

  • Kim, Myung-Cheol;Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.29 no.3
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    • pp.337-350
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    • 2000
  • This paper suggests a new diagnostic measure and a stopping rule for detecting influential observations in multiple discriminant analysis (MDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the fractional Bayes factor methodology. The Bayes factor is taken as a discriminatory information in MDA. It is shown that the effect of an observation over the discriminatory information is fully explained by the diagnostic measure. Based on the measure, we suggest a stopping rule for detecting influential observations in a given training sample. As a tool for interpreting the measure a graphical method is sued. Performance of the method is used. Performance of the method is examined through two illustrative examples.

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Exploiting Multichannel Diversity in Spectrum Sharing Systems Using Optimal Stopping Rule

  • Xu, Yuhua;Wu, Qihui;Wang, Jinlong;Anpalagan, Alagan;Xu, Yitao
    • ETRI Journal
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    • v.34 no.2
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    • pp.272-275
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    • 2012
  • This letter studies the problem of exploiting multichannel diversity in a spectrum sharing system, where the secondary user (SU) sequentially explores channel state information on the licensed channels with time consumption. To maximize the expected achievable throughput for the SU, we formulate this problem as an optimal stopping problem, whose objective is to choose the right channel to stop exploration based on the observed signal-to-noise ratio sequence. Moreover, we propose a myopic but optimal rule, called one-stage look-ahead rule, to solve the stopping problem.

Efficient Strategies to Verify VHDL Model (VHDL 모델의 효율적인 검증 방법)

  • 김강철
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.526-529
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    • 2003
  • This paper presents two strategies to refute clock cycles when using stopping rule in VHDL model verification. The first method is that a semi-random variable is defined and the data that stay in the range of semi-random variable are skipped when stopping rule is running. The second one is to keep the old values of parameters when phases are changed. 12 VHDL models are examined to observe the effectiveness of strategies.

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Bayes Stopping Rule for MAC Scheme Wireless Sensor Networks (무선 센서 망에서 MAC 방식을 위한 Bayes 중지 규칙)

  • Park, Jin-Kyung;Choi, Cheon-Won
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.7
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    • pp.53-61
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    • 2008
  • Consider a typical wireless sensor network in which stem nodes form the backbone network of mesh topology while each stem node together with leaf nodes in its vicinity forms a subnetwork of star topology. In such a wireless sensor network, we must heed the following when we design a MAC scheme supporting the packet delivery from a leaf node to a stem node. First, leaf nodes are usually battery-powered and it is difficult to change or recharge their batteries. Secondly, a wireless sensor network is often deployed to collect and update data periodically. Late delivery of a data segment by a sensor node causes the sink node to defer data processing and the data segment itself to be obsolete. Thirdly, extensive signaling is extremely limited and complex computation is hardly supported. Taking account of these facts, a MAC scheme must be able to save energy and support timeliness in packet delivery while being simple and robust as well. In this paper, we propose a version of ALOHA as a MAC scheme for a wireless sensor network. While conserving the simplicity and robustness of the original version of ALOHA, the proposed version of ALOHA possesses a distinctive feature that a sensor node decides between stop and continuation prior to each delivery attempt for a packet. Such a decision needs a stopping rule and we suggest a Bayes stopping rule. Note that a Bayes stopping rule minimizes the Bayes risk which reflects the energy, timeliness and throughput losses. Also, a Bayes stopping rule is practical since a sensor node makes a decision only using its own history of delivery attempt results and the prior information about the failure in delivery attempt. Numerical examples confirm that the proposed version of ALOHA employing a Bayes stopping rule is a useful MAC scheme in the severe environment of wireless sensor network.

Maximum Tolerated Dose Estimation by Stopping Rule and SM3 Design in a Phase I Clinical Trial (제 1상 임상시험에서 멈춤 규칙과 SM3 디자인을 이용한 최대허용용량 추정법)

  • Kim, Byoungchan;Kim, Dongjae
    • The Korean Journal of Applied Statistics
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    • v.27 no.1
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    • pp.13-20
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    • 2014
  • Phase I Clinical Trials estimate a Maximum Tolerated Dose(MTD). In this paper, an MTD estimation method applied stopping rule is proposed for Phase I Clinical Trials. The suggested MTD estimation method is compared to the Continual Reassessment Method(CRM) method using a Monte Carlo simulation study.

A study on Optimizing Fourier Series Density estimates (퓨리에 급수기법에 의한 밀도함수추정의 최적화 고찰)

  • Kim, Jong-Tae;Lee, Sung-Ho;Kim, Kyung-Moo
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.1
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    • pp.9-20
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    • 1997
  • Several methods are proposed for optimizing Fourier series estimators with respect to Mean Integrated Square Error metrics. Traditionally, such method have followed. one of two basic strategies; A stopping rules or the rules of determine multipliers. A central hypothesis of this study is that better estimates can be obtained by combining the two strategies. A new multiplier sequence is proposed, which used in conjunction with any of the stopping rules, is shown to improve the performance of estimator which relies solely on a stopping rule.

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