• Title/Summary/Keyword: Randomized block design

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Efficient determination of the size of experiments by using graphs in balanced design of experiments (균형된 실험계획법에서 그래프를 활용한 실험의 크기의 효율적인 결정)

  • Lim, Yong B.;Youn, Sora;Chung, Jong Hee
    • Journal of Korean Society for Quality Management
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    • v.46 no.3
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    • pp.651-658
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    • 2018
  • Purpose: The algorithm described in Lim(1998) is available to determine the sample size directly given specified significance level, power and signal-to-noise ratio. We research on the efficient determination of the sample size by visual methods. Methods: We propose three graphs for investigating the mutual relationship between the sample size r, power $1-{\beta}$ and the detectable signal-to-noise ratio ${\Delta}$. First graph shows the relationship between ${\Delta}$ and $1-{\beta}$ for the given r and it can be checked whether the power is sufficient enough. Second graph shows the relationship between r and ${\Delta}$ for the given power $1-{\beta}$. Third graph shows the relationship between r and $1-{\beta}$ for the given ${\Delta}$. It can be checked that which effects are sensitive to the efficient sample size by investigating those graphs. Results: In factorial design, randomized block design and the split plot design how to determine the sample size directly given specified significance level, power and signal-to-noise ratio is programmed by using R. A experiment to study the split plot design in Hicks(1982) is used as an example. We compare the sample sizes calculated by randomized block design with those by split plot design. By using graphs, we can check the possibility of reducing the sample size efficiently. Conclusion: The proposed visual methods can help an engineer to make a proper plan to reduce the sample size.

A Comparative Study of Restricted Randomization Methods in Clinicla Trials

  • Huh, Myung-Hoe
    • Journal of the Korean Statistical Society
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    • v.14 no.1
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    • pp.48-55
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    • 1985
  • In clinical trials subjects are avalible sequentially and must be assigned to treatments immediately. Completely randomized procedure for the allocation of treatments to each subject may result in severe imbalance among the number of subjects in treatment groups, especially for small experiments or interim analyses of large experiments. In this study, restricted randomization methods such as biased coin designs (Efron, 1971), permuted block design, and truncated binomial design are compared to teh completely randomized design in the presence of selection and/or accidential bias by Monte Carlo simulations.

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A Distribution-Free Rank Test for Ordered Alternatives in a Randomized Block Design

  • Kim, Dong-Hee;Song, Moon-Sup;Kim, Woo-Chul
    • Journal of the Korean Statistical Society
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    • v.15 no.1
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    • pp.9-25
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    • 1986
  • In this paper we propose a distribution-free rank test for ordered alternatives in a randomized block design and investigate the properties of the proposed test. The proposed test is an extension of the Page test to allow replications in each cell. Some asymptotic properties including ARE's are investigated. A small sample Monte Carlo study was performed to compare the powers of the test considered in this paper for small samples. The results show that our proposed test is robust and efficient in the case of equally-spaced treatment effects.

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Efficacy of Pericapsular Nerve Group Block for Pain Reduction and Opioid Consumption after Total Hip Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

  • Eunsoo Kim;Won Chul Shin;Sang Min Lee;Min Jun Choi;Nam Hoon Moon
    • Hip & pelvis
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    • v.35 no.2
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    • pp.63-72
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    • 2023
  • The aim of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) for comparison of the effectiveness of pericapsular nerve group (PENG) block with that of other analgesic techniques for reduction of postoperative pain and consumption of opioids after total hip arthroplasty (THA). A search of records in the PubMed, Embase, and Cochrane Library, and ClinicalTrials.gov databases was conducted in order to identify studies comparing the effect of the PENG block with that of other analgesics on reduction of postoperative pain and consumption of opioids after THA. Determination of eligibility was based on the PICOS (participants, intervention, comparator, outcomes, and study design) criteria as follows: (1) Participants: patients who underwent THA. (2) Intervention: patients who received a PENG block for management of postoperative pain. (3) Comparator: patients who received other analgesics. (4) Outcomes: numerical rating scale (NRS) score and opioid consumption during different periods. (5) Study design: clinical RCTs. Five RCTs were finally included in the current meta-analysis. Significantly lower postoperative opioid consumption at 24 hours after THA was observed in the group of patients who received the PENG block compared with the control group (standard mean difference=-0.36, 95% confidence interval -0.64 to -0.08). However, no significant reduction in NRS score at 12, 24, and 48 hours after surgery and opioid consumption at 48 hours after THA was observed. The PENG block showed better results for opioid consumption at 24 hours after THA compared with other analgesics.

Analysis of freshness of rice depending on packing materials using MANOVA (다변량 분산분석을 이용한 포장 재질에 따른 쌀의 신선도 분석)

  • Kim, Seong-Ju
    • The Korean Journal of Applied Statistics
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    • v.29 no.7
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    • pp.1421-1428
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    • 2016
  • This paper concerns the freshness of rice depending on packing materials using MANOVA. Freshness of rice is measured in terms of moisture content and rice flavor. Ordinary paper and charcoal-coated paper are compared as packing materials. Storing places are considered as a block. The bivariate observations of moisture content and the rice flavor are compared using MANOVA for a completely randomized block design. It is observed that there is a significant difference between ordinary paper and charcoal-coated paper. Therefore we apply ANOVA for moisture content and rice flavor, respectively. Significant differences are observed for the moisture content but not for the rice flavor.

Power analysis for $2{\times}2$ factorial in randomized complete block design (블럭이 존재하는 $2{\times}2$ 요인모형의 검정력 분석)

  • Choi, Young-Hun
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.2
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    • pp.245-253
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    • 2011
  • Powers of rank transformed statistic for testing main effects and interaction effects for $2{\times}2$ factorial design in randomized complete block design are very superior to powers of parametric statistic without regard to the block size, composition method of effects and the type of population distributions such as exponential, double exponential, normal and uniform. $2{\times}2$ factorial design in RCBD increases error effects and decreases powers of parametric statistic which results in conservativeness. However powers of rank transformed statistic maintain relative preference. In general powers of rank transformed statistic show relative preference over those of parametric statistic with small block size and big effect size.

On the distribution-free tests for umbrella alternatives in a randomized block design (화률화 블록 계획법에서 우산형 대립가설에 대한 분포부관 검정법의 연구)

  • 김동희;김영철
    • The Korean Journal of Applied Statistics
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    • v.5 no.1
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    • pp.41-57
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    • 1992
  • Distribution-free test for umbrella alternatives in a randomized block design is proposed and asymptotic properties test statistics and the asymptotic relatives efficiency (ARE) of the proposed test statistics with respect to the Puri's parametric method are investigated. For given peak points 2,3,4, with 4 blocks and 5 treatments, and with 3 blocks and 5 treatments : for given peak point 3, with 2 blocks and 4 treatments : from the small sample Monte Carlo Study, the empirical powers between the proposed test and Puri's test are compared. Throughout the simulation results, the proposed test statistic is efficient for the heavy tailed distributions.

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Effect of Cassava Hay in High-quality Feed Block as Anthelmintics in Steers Grazing on Ruzi Grass

  • Wanapat, Metha;Khampa, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.5
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    • pp.695-698
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    • 2006
  • Six, one-year old dairy steers were randomly divided into two groups according to a Completely randomized design (CRD) to receive high-quality feed block (HQFB) without cassava hay and drenching (HQFB1+Ivomex) and HQFB with cassava hay (HQFB2) as block licks while grazing on Ruzi grass pasture. During the eight weeks, fecal parasitic egg counts dramatically declined for both treatment groups with 63.2 and 27.6% reduction from initial period for HQFB1+Ivomex and HQFB2, respectively. However, digestion of coefficients of nutrients particularly OM, were significantly higher in HQFB2 than, those in HQFB1+Ivomex, in addition, ADG of animals in HQFB2 tended to be higher than the group on HQFB1. It was, hence concluded that cassava hay could not only provide as a protein source but also serve as an anthelmintic in ruminants.

Statistical Design of Experiments and Analysis: Hierarchical Variance Components and Wafer-Level Uniformity on Gate Poly-Silicon Critical Dimension (통계적 실험계획 및 분석: Gate Poly-Silicon의 Critical Dimension에 대한 계층적 분산 구성요소 및 웨이퍼 수준 균일성)

  • Park, Sung-min;Kim, Byeong-yun;Lee, Jeong-in
    • Journal of Korean Institute of Industrial Engineers
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    • v.29 no.2
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    • pp.179-189
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    • 2003
  • Gate poly-silicon critical dimension is a prime characteristic of a metal-oxide-semiconductor field effect transistor. It is important to achieve the uniformity of gate poly-silicon critical dimension in order that a semiconductor device has acceptable electrical test characteristics as well as a semiconductor wafer fabrication process has a competitive net-die-per-wafer yield. However, on gate poly-silicon critical dimension, the complexity associated with a semiconductor wafer fabrication process entails hierarchical variance components according to run-to-run, wafer-to-wafer and even die-to-die production unit changes. Specifically, estimates of the hierarchical variance components are required not only for disclosing dominant sources of the variation but also for testing the wafer-level uniformity. In this paper, two experimental designs, a two-stage nested design and a randomized complete block design are considered in order to estimate the hierarchical variance components. Since gate poly-silicon critical dimensions are collected from fixed die positions within wafers, a factor representing die positions can be regarded as fixed in linear statistical models for the designs. In this context, the two-stage nested design also checks the wafer-level uniformity taking all sampled runs into account. In more detail, using variance estimates derived from randomized complete block designs, Duncan's multiple range test examines the wafer-level uniformity for each run. Consequently, a framework presented in this study could provide guidelines to practitioners on estimating the hierarchical variance components and testing the wafer-level uniformity in parallel for any characteristics concerned in semiconductor wafer fabrication processes. Statistical analysis is illustrated for an experimental dataset from a real pilot semiconductor wafer fabrication process.

An UHISRL design to protect patient's privacy and to block its illegal access based on RFID (환자의 프라이버시 보호와 불법 접근 차단을 위한 RFID 기반 UHISRL 설계)

  • Lee, Byung Kwan;Jeong, Eun Hee
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.3
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    • pp.57-66
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    • 2014
  • This paper proposes the UHISRL(Ubiquitous Healthcare Information System based on Real Time Location) which manages patient, doctor, medicine by using RFID. The proposed UHISRL monitors the patient's health state, and enables us to confirm the result with Smart Phone and Tablet PC. Also, it can block Replay and Spoofing attack by using the ERHL(Extended Randomized Hash Lock) authentication scheme designed in this paper. A patient privacy is enhanced by limiting UHISRL DB access according to attributes with CP-ABE (Cipher Text - Attributed based Encryption) technique. Specially, UHISRL can prevent an unexpected accident by monitoring a chronic patient's emergency situation in real time.