• Title/Summary/Keyword: significance testing

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MPI-GWAS: a supercomputing-aided permutation approach for genome-wide association studies

  • Paik, Hyojung;Cho, Yongseong;Cho, Seong Beom;Kwon, Oh-Kyoung
    • Genomics & Informatics
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    • v.20 no.1
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    • pp.14.1-14.4
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    • 2022
  • Permutation testing is a robust and popular approach for significance testing in genomic research that has the advantage of reducing inflated type 1 error rates; however, its computational cost is notorious in genome-wide association studies (GWAS). Here, we developed a supercomputing-aided approach to accelerate the permutation testing for GWAS, based on the message-passing interface (MPI) on parallel computing architecture. Our application, called MPI-GWAS, conducts MPI-based permutation testing using a parallel computing approach with our supercomputing system, Nurion (8,305 compute nodes, and 563,740 central processing units [CPUs]). For 107 permutations of one locus in MPI-GWAS, it was calculated in 600 s using 2,720 CPU cores. For 107 permutations of ~30,000-50,000 loci in over 7,000 subjects, the total elapsed time was ~4 days in the Nurion supercomputer. Thus, MPI-GWAS enables us to feasibly compute the permutation-based GWAS within a reason-able time by harnessing the power of parallel computing resources.

Use of SSR Markers to Complement Tests of Distinctiveness, Uniformity, and Stability (DUS) of Pepper (Capsicum annuum L.) Varieties

  • Kwon, Yong-Sham;Lee, Je-Min;Yi, Gi-Bum;Yi, Seung-In;Kim, Kyung-Min;Soh, Eun-Hee;Bae, Kyung-Mi;Park, Eun-Kyung;Song, In-Ho;Kim, Byung-Dong
    • Molecules and Cells
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    • v.19 no.3
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    • pp.428-435
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    • 2005
  • This study was carried out to assess the potential of SSR markers for variety identification by comparing SSR markers and morphological traits in tests of distinctiveness, uniformity, and stability (DUS) of pepper (Capsicum annuum L.) varieties. Twenty-seven SSR markers were polymorphic in 66 pepper varieties, revealing a total of 89 alleles. Average polymorphism information content (PIC) value was 0.529, ranging from 0.03 to 0.877. Cluster analysis of the band patterns separated the varieties into three groups corresponding to varietal types. Morphological trait-based clustering showed some degree of similarity to dendrogram topologies based on the SSR index. However, no significance correlation was found between the SSR and morphological data. SSR markers could be used to complement a DUS test of a candidate variety and to select complimentary varieties by pre-screening existing varieties in the context of protecting new varieties of pepper.

Use of the estimated critical values adapting a regression equation for the approximate entropy test

  • Cha, Kyung-Joon;Ryu, Je-Seon
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.2
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    • pp.77-85
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    • 2002
  • The statistical testing methods have been widely recognized to determine the plain and cipher texts. In fact, the randomness for a sequence from an encryption algorithm is necessary to guarantee security and reliance of cipher algorithm. Thus, the statistical randomness tests are used to discover cipher text. In this paper, we would provide the critical value for an approximate entropy test by estimating the nonlinear regression equation when the number of sequence and the level of significance are given. Thus, we can discern plan and cipher text for real problem with given number of sequence and the level of significance. Also, we confirm the fitness of the estimated critical values from the rate of success for plain or cipher text.

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Effects of Smoking Cessation Education for Patients with Percutaneous Coronary Intervention (경피적 관상동맥 중재술을 받은 환자의 금연교육이 흡연에 미치는 효과)

  • Jun, Won-Hee;Yun, Hyun-Suk
    • Korean Journal of Adult Nursing
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    • v.24 no.3
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    • pp.274-283
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    • 2012
  • Purpose: The purpose of this study was to investigate the effects of a smoking cessation education for patients with percutaneous coronary intervention. Methods: The study was a quasi-experimental study with a non-equivalent control group non-synchronized design. The Sixty subjects were assigned to either the treatment group. The treatment intervention was a onetime program during hospitalization. Data were collected during several time periods: before treatment, immediately after treatment, two weeks later, and one month after the treatment. Data were analyzed with the SPSS 14.0 program with an independent t-test, $x^2$ test, repeated measures ANOVA. Results: There were significant differences between the two groups in terms of knowledge and attitude. The significance was absent for the testing two weeks post group intervention and then one month later the significance was again detected in the amount of smoking and smoking behavior. Conclusion: The results of this study suggest that smoking cessation education could be utilized for inpatients with percutaneous coronary intervention as nursing intervention in hospitals effectively. Further research is recommended in order to understand the change in significance in the different time periods.

A Comparison of Models for Predicting Discretionary Accruals: A Cross-Country Analysis

  • ACAR, Goksel;COSKUN, Ali
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.315-328
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    • 2020
  • In this study, we examined various aspects of discretionary accruals. We compared the power of Jones Model (JM), Modified Jones Model (MJM) and Performance Matched Model (PMM). Furthermore, we tested whether accruals derived from cash flow approach or balance sheet approach provide better results and we investigated the significance of country and industry control variables in models. In order to perform these tests, we constructed thirty equations. The data consists of 319 non-financial companies over five years in the GCC region. We used panel data regression models, and testing suggests us to use random effect model as the most suitable one. The results show that PMM has the highest explanatory power among models and it is followed by JM and MJM, consecutively. Secondly, results reveal that accruals derived from cash flow approach provide more accurate results. Moreover, country dummies are significant in models with cash flow approach and they lose significance in balance sheet approach. We differentiated industries due to two different classifications: the first group with higher number of industries is more precise compared to the second group with a narrower scope and lower number of industries. The model including both industrial and country-wise dummies scores highest in significance.

A Study on the Prevention Measures of Human Error with Railway Drivers (열차 운전 종사자를 대상으로 한 인적오류의 개선 방안 연구)

  • Kim, Dong Won;Song, Bo Young;Lee, Hi Sung
    • Journal of the Korean Society of Safety
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    • v.34 no.1
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    • pp.76-81
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    • 2019
  • In this study, the causes of human error were identified through the survey of the drivers of the three organizations: Seoul Metro, Seoul Metropolitan Rapid Transit Corporation, and Korail. It was started with the aim of finding and eliciting causes in various directions including human factors, job factors, and environmental factors. The Cronbach alpha value was 0.95 for the reliability significance of the stress-induced factors in the operational area. The significance probability for organisational factors was shown to be 0.82, and the significance of the sub-accident experience and the driving skill factors in operation was 0.81 In addition, the analysis results showed that stress-induced in the field of driving is higher than the human factors in the reliability analysis. The results of the analysis confirmed that the reliability of the organizational and operational stress-induced factors was higher than other causes. In order to reduce urban railroad accidents, this paper suggests a method for operating safe urban railroad through the minimization human errors.

Analysis of Public System's Quality and User Behavior Using PLS-MGA Methodology : An Institutional Perspective (PLS-MGA 방법론을 활용한 제도론적 관점에서의 공공제도 품질과 사용자 행태의 분석)

  • Lee, Jae Yul;Hwang, Seung-June
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.2
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    • pp.78-91
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    • 2017
  • In this study, we conducted a comparative study on user's perception and behavior on public system service (PSS) using institutionalism theory and MGA (multi-group analysis) methodology. In particular, this study focuses on how institutional isomorphism is applied to public system services and how MGA can be implemented correctly in a variance based SEM (structural equation model) such as PLS (partial least square). A data set of 496 effective responses was collected from pubic system users and an empirical research was conducted using three segmented models categorized by public proximity theory (public firms = 113, government contractors = 210, private contractors = 173). For rigorous group comparisons, each model was estimated by the same indicators and approaches. PLS-SEM was used in testing research hypotheses, followed by parametric and non-parametric PLS-MGA procedures in testing categorical moderation effects. This study applied novel procedures for testing composite measurement invariance prior to multi-group comparisons. The following main results and implications are drawn : 1) Partial measurement invariance was established. Multi-group analysis can be done by decomposed models although data can not be pooled for one integrated model. 2) Multi-group analysis using various approaches showed that proximity to public sphere moderated some hypothesized paths from quality dimensions to user satisfaction, which means that categorical moderating effects were partially supported. 3) Careful attention should be given to the selection of statistical test methods and the interpretation of the results of multi-group analysis, taking into account the different outcomes of the PLS-MGA test methods and the low statistical power of the moderating effect. It is necessary to use various methods such as comparing the difference in the path coefficient significance and the significance of the path coefficient difference between the groups. 4) Substantial differences in the perceptions and behaviors of PSS users existed according to proximity to public sphere, including the significance of path coefficients, mediation and categorical moderation effects. 5) The paper also provides detailed analysis and implication from a new institutional perspective. This study using a novel and appropriate methodology for performing group comparisons would be useful for researchers interested in comparative studies employing institutionalism theory and PLS-SEM multi-group analysis technique.

Goodness of Fit Testing for Exponential Distribution in Step-Stress Accelerated Life Testing (계단충격가속수명시험에서의 지수분포에 대한 적합도검정)

  • Jo, Geon-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.5 no.2
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    • pp.75-85
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    • 1994
  • In this paper, I introduce the goodness-of-fit test statistics for exponential distribution using accelerated life test data. The ALT lifetime data were obtained by assuming step-stress ALT model, specially TRV model introduced by DeGroot and Goel(1979). The critical values are obtained for proposed test statistics, Kolmogorov-Smirnov, Kuiper, Watson, Cramer-von Mises, Anderson-Darling type, under various sample sizes and significance levels. The powers of the five test statistic are compared through Monte-Cairo simulation technique.

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NDE for Realising Better Quality of Life in the Context of INDIA - An Emerging Economy

  • Raj, Baldev
    • Journal of the Korean Society for Nondestructive Testing
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    • v.23 no.5
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    • pp.497-519
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    • 2003
  • Science and technology is an essential ingredient of the progress in modern society. Measurements enable action and actions enable results. Non-Destructive Evaluation (NDE) - the science and technology of measurements without affecting the Properties and performance of the test object is an interdisciplinary domain area of high significance far ensuring quality, productivity and safety thus enabling better qualify of lift to the inhabitants on this planet. The test object can be material, component, plant, earth, environment etc. Total qualify management, total productivity management, concurrent engineering and many other essential ingredients of success in plant engineering and manufacturing industry are dependent on NDE far success and good returns on investments.

Balanced hypothesis testing for interactions of unbalanced case using analysis of means (평균분석을 이용한 교호작용의 균형 검정 방법 불균형 관측치의 경우)

  • 김병천;정강모
    • The Korean Journal of Applied Statistics
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    • v.3 no.1
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    • pp.89-103
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    • 1990
  • An analysis of mean procedure is presented for testing the significance of two factor interactions for unbalanced case. When at least one factor if at only two levels, the technique is the same as that of Ott(1967) and Nelson(1988) except that we have used the critical value by using the Sidak's multiplicative inequality. The technique can be extended to the case in which both factors more than two levels. Tables of critical values g($\alpha ; (p, q) ; v$) are given for $\alpha$=0.05 and 0.01 ; (p, q) combinations satisfying $3 \leq p \leq q \leq 5$ ; and various degrees of freedom v. We present and prove the formula of the variance of the interactions for the n-way model.

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