A report on the paper “Sungsu Kim. 2019. The probable error in the hypothesis test of normal means using a small sample. Communications in Statistics - Theory and Methods. DOI: 10.1080/03610926.2019.1703135.”

2020 ◽  
pp. 1-3
Author(s):  
Kalimuthu Krishnamoorthy ◽  
Arvind K. Shah
Keyword(s):  
Hypothesis Test ◽  
Small Sample ◽  
Probable Error ◽  
Normal Means

A threshold AR(1) model

1984 ◽  
Vol 21 (02) ◽  
pp. 270-286 ◽  
Author(s):  
Joseph D. Petruccelli ◽  
Samuel W. Woolford
Keyword(s):  
Hypothesis Test ◽  
Threshold Model ◽  
Sufficient Conditions ◽  
Simulated Data ◽  
Small Sample ◽  
Regularity Conditions ◽  
Test Statistic ◽  
Asymptotically Normal ◽  
Least Squares Estimators ◽  
Necessary And Sufficient

We consider the model where φ 1, φ 2 are real coefficients, not necessarily equal, and the at ,'s are a sequence of i.i.d. random variables with mean 0. Necessary and sufficient conditions on the φ 's are given for stationarity of the process. Least squares estimators of the φ 's are derived and, under mild regularity conditions, are shown to be consistent and asymptotically normal. An hypothesis test is given to differentiate between an AR(1) (the case φ 1 = φ 2) and this threshold model. The asymptotic behavior of the test statistic is derived. Small-sample behavior of the estimators and the hypothesis test are studied via simulated data.

scholarly journals Spectral Analysis on Time-Course Expression Data: Detecting Periodic Genes Using a Real-Valued Iterative Adaptive Approach

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Kwadwo S. Agyepong ◽  
Fang-Han Hsu ◽  
Edward R. Dougherty ◽  
Erchin Serpedin
Keyword(s):  
Time Course ◽  
Hypothesis Test ◽  
Expression Profiles ◽  
Real Data ◽  
Small Sample ◽  
Irregular Sampling ◽  
Periodic Signal ◽  
Expression Data ◽  
Adaptive Approach ◽  
Iterative Adaptive Approach

Time-course expression profiles and methods for spectrum analysis have been applied for detecting transcriptional periodicities, which are valuable patterns to unravel genes associated with cell cycle and circadian rhythm regulation. However, most of the proposed methods suffer from restrictions and large false positives to a certain extent. Additionally, in some experiments, arbitrarily irregular sampling times as well as the presence of high noise and small sample sizes make accurate detection a challenging task. A novel scheme for detecting periodicities in time-course expression data is proposed, in which a real-valued iterative adaptive approach (RIAA), originally proposed for signal processing, is applied for periodogram estimation. The inferred spectrum is then analyzed using Fisher’s hypothesis test. With a proper -value threshold, periodic genes can be detected. A periodic signal, two nonperiodic signals, and four sampling strategies were considered in the simulations, including both bursts and drops. In addition, two yeast real datasets were applied for validation. The simulations and real data analysis reveal that RIAA can perform competitively with the existing algorithms. The advantage of RIAA is manifested when the expression data are highly irregularly sampled, and when the number of cycles covered by the sampling time points is very reduced.

scholarly journals Statistical Reliability Assessment for Small Sample of Failure Data of Dumper Diesel Engines Based on Power Law Process and Maximum Likelihood Estimation

2021 ◽  
Vol 11 (12) ◽  
pp. 5387
Author(s):  
Brajeshkumar Kishorilal Dinkar ◽  
Alok Kumar Mukhopadhyay ◽  
Somnath Chattopadhyaya ◽  
Shubham Sharma ◽  
Firoz Alam ◽  
...  
Keyword(s):  
Diesel Engines ◽  
Hypothesis Test ◽  
Meta Analysis ◽  
Likelihood Estimation ◽  
Small Sample ◽  
Trend Test ◽  
Failure Data ◽  
Subsystem Level ◽  
Dump Trucks ◽  
Engine Failure

Dumpers or dump trucks are used all over the world to move overburden from many opencast mines. Diesel engines are the main driving force behind the trucks. The frequency of damage due to the failure of diesel engines is enormous. Therefore, efforts are necessary to analyze failure to reduce the downtime periods. A detailed analysis of engine failure at the subsystem level needs to be done. Reliability analysis and maintenance planning remain the norm in this regard. The obstacle faced while analysing the reliability of dumpers was the availability of a large number of data failures. In this paper, this issue is addressed by using Common Beta Hypothesis test and Meta-analysis test. The engine is divided into five subsystems. The result shows that all five subsystems pass the CBH test and Meta-analysis test. Accordingly, the failure data is grouped. The trend test of grouped failure data shows that the Failure data of two subsystems follows the independent and identically distributed characteristics while the remaining three do not follow it. The reliability is estimated for all five subsystems. Finally, fuel supply subsystems show the highest reliability while the lowest value is seen for self-starting subsystems.

A threshold AR(1) model

1984 ◽  
Vol 21 (2) ◽  
pp. 270-286 ◽  
Author(s):  
Joseph D. Petruccelli ◽  
Samuel W. Woolford
Keyword(s):  
Hypothesis Test ◽  
Threshold Model ◽  
Sufficient Conditions ◽  
Simulated Data ◽  
Small Sample ◽  
Regularity Conditions ◽  
Test Statistic ◽  
Asymptotically Normal ◽  
Least Squares Estimators ◽  
Necessary And Sufficient

We consider the model where φ1, φ2 are real coefficients, not necessarily equal, and the at,'s are a sequence of i.i.d. random variables with mean 0. Necessary and sufficient conditions on the φ 's are given for stationarity of the process. Least squares estimators of the φ 's are derived and, under mild regularity conditions, are shown to be consistent and asymptotically normal. An hypothesis test is given to differentiate between an AR(1) (the case φ1 = φ2) and this threshold model. The asymptotic behavior of the test statistic is derived. Small-sample behavior of the estimators and the hypothesis test are studied via simulated data.

scholarly journals Daily 6: An Approach to Foster Oral Fluency of English as a Foreign Language in Adolescents

2019 ◽  
Vol 21 (2) ◽  
pp. 29-44
Author(s):  
Roso Freddy Cadena-Aguilar ◽  
Javier Hernando Ortega-Cuellar ◽  
Albedro Cadena-Aguilar
Keyword(s):  
Action Research ◽  
Foreign Language ◽  
Research Study ◽  
Hypothesis Test ◽  
Achievement Tests ◽  
Small Sample ◽  
Oral Fluency ◽  
Filled Pauses ◽  
Language Data ◽  
Action Research Study

This action research study aimed to examine the possible impact of the Daily 6 approach on the oral fluency in English of 13 adolescents. This approach (extension of the existing Daily 5™ framework) introduced a sixth step, “speak to someone”, to respond to the lack of oral fluency limiting participants’ overall speaking performance in English as a foreign language. Data were gathered through surveys, diagnostic and achievement tests, and recordings using VoiceThread™. The coding and a small sample hypothesis test for means analysis unveiled the significance of the Daily 6 approach to enhance oral fluency through technology. Results displayed gains in oral fluency (length of runs, silent pauses, length of pauses, filled pauses, and pace) and positive changes in attitudinal responses within a low-anxiety environment.

scholarly journals Heterogeneous Clutter Suppression for Airborne Radar STAP Based on Matrix Manifolds

2021 ◽  
Vol 13 (16) ◽  
pp. 3195
Author(s):  
Xixi Chen ◽  
Yongqiang Cheng ◽  
Hao Wu ◽  
Hongqiang Wang
Keyword(s):  
Hypothesis Test ◽  
Real Data ◽  
Small Sample ◽  
Training Data ◽  
Superior Performance ◽  
Airborne Radar ◽  
Heterogeneous Environments ◽  
Clutter Suppression ◽  
Negative Effects ◽  
Matrix Manifolds

Clutter suppression in heterogeneous environments is a serious challenge for airborne radar. To address this problem, a matrix-manifold-based clutter suppression method is proposed. First, the distributions of training data in heterogeneous environments are analyzed, while the received data are characterized on a Riemannian manifold of Hermitian positive definite matrices. It is indicated that the training data with different distributions with the same power are separated, whereas data with the same distribution are closer together. This implies that the underlying geometry of the data can be better revealed by manifolds than by Euclidean space. Based on these properties, homogeneous training data are selected by establishing a binary hypothesis test such that the negative effects of the use of heterogeneous samples are alleviated. Moreover, as exploiting a geometric metric on manifolds to reveal the underlying information of data, experimental results on both simulated and real data validate that the proposed method has a superior performance with small sample support.

Probing the ultrastructure of the mitotic and meiotic spindle in eggs: An expeditious approach based on semi-thin (0.25 μm) serial sections

1983 ◽  
Vol 41 ◽  
pp. 552-555
Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
Meiotic Spindle ◽  
Serial Sections ◽  
Mitotic Apparatus ◽  
Thin Sections ◽  
Cell Cycles ◽  
Ultrastructural Studies

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).

Validating the Factor Structure of the Stigma of Suicide Scale–Short Form Spanish Version Among Healthcare Students

Crisis ◽  
2020 ◽  
pp. 1-5
Author(s):  
Ruthmarie Hernández-Torres ◽  
Paola Carminelli-Corretjer ◽  
Nelmit Tollinchi-Natali ◽  
Ernesto Rosario-Hernández ◽  
Yovanska Duarté-Vélez ◽  
...  
Keyword(s):  
Factor Structure ◽  
Structural Equation ◽  
Short Form ◽  
Small Sample Size ◽  
Small Sample ◽  
Spanish Version ◽  
Equation Modeling ◽  
Cross Sectional ◽  
Healthcare Students ◽  
Spanish Speaking

Abstract. Background: Suicide is a leading cause of death among Spanish-speaking individuals. Suicide stigma can be a risk factor for suicide. A widely used measure is the Stigma of Suicide Scale-Short Form (SOSS-SF; Batterham, Calear, & Christensen, 2013 ). Although the SOSS-SF has established psychometric properties and factor structure in other languages and cultural contexts, no evidence is available from Spanish-speaking populations. Aim: This study aims to validate a Spanish translation of the SOSS-SF among a sample of Spanish-speaking healthcare students ( N = 277). Method: We implemented a cross-sectional design with quantitative techniques. Results: Following a structural equation modeling approach, a confirmatory factor analysis (CFA) supported the three-factor model proposed by Batterham and colleagues (2013) . Limitations: The study was limited by the small sample size and recruitment by availability. Conclusion: Findings suggest that the Spanish version of the SOSS-SF is a valid and reliable tool with which to examine suicide stigma among Spanish-speaking populations.

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