The Independent Pairs Assumption in Hypothesis Tests Based on Rank Correlation Coefficients

1987 ◽  
Vol 41 (1) ◽  
pp. 40 ◽  
Author(s):  
Sallie Keller-McNulty ◽  
Mark McNulty
Keyword(s):  
Rank Correlation ◽  
Correlation Coefficients ◽  
Hypothesis Tests

scholarly journals A Preliminary Study on Dependence of Mercury Distribution on the Degree of Coalification in Ningwu Coalfield, Shanxi, China

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3119
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang
Keyword(s):  
Linear Correlation ◽  
Bituminous Coal ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Chemical Extraction ◽  
Mercury Distribution ◽  
Sequential Chemical Extraction ◽  
Average Proportion ◽  
Total Proportion ◽  
The Relationship

Mercury (Hg) is a toxic trace element emitted from coal conversion and utilization. Samples with different coal ranks and gangue from Ningwu Coalfield are selected and investigated in this study. For understanding dependence of mercury distribution characteristics on coalification degree, Pearson regression analysis coupled with Spearman rank correlation is employed to explore the relationship between mercury and sulfur, mercury and ash in coal, and sequential chemical extraction method is adopted to recognize the Hg speciation in the samples of coal and gangue. The measured results show that Hg is positively related to total sulfur content in coal and the affinity of Hg to different sulfur forms varies with the coalification degree. Organic sulfur has the biggest impact on Hg in peat, which becomes weak with increasing the coalification degree from lignite to bituminous coal. Sulfate sulfur is only related to Hg in peat or lignite as little content in coal. However, the Pearson linear correlation coefficients of Hg and pyritic sulfur are relatively high with 0.479 for lignite, 0.709 for sub-bituminous coal and 0.887 for bituminous coal. Hg is also related to ash content in coal, whose Pearson linear correlation coefficients are 0.504, 0.774 and 0.827 respectively, in lignite, sub-bituminous coal and bituminous coal. Furthermore, Hg distribution is directly depended on own speciation in coal. The total proportion of F2 + F3 + F4 is increased from 41.5% in peat to 87.4% in bituminous coal, but the average proportion of F5 is decreased from 56.8% in peat to 12.4% in bituminous coal. The above findings imply that both Hg and sulfur enrich in coal largely due to the migration from organic state to inorganic state with the increase of coalification degree in Ningwu Coalfield.

scholarly journals Comparison of a picture-sort food-frequency questionnaire with 24-hour dietary recalls in an elderly Utah population

2001 ◽  
Vol 4 (5) ◽  
pp. 961-970 ◽  
Author(s):  
Heidi J Wengreen ◽  
Ronald G Munger ◽  
Siew Sun Wong ◽  
Nancy A West ◽  
Richard Cutler
Keyword(s):  
Food Frequency Questionnaire ◽  
Dietary Assessment ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Assessment Method ◽  
Impaired Hearing ◽  
Low Literacy ◽  
Food Frequency ◽  
Dietary Recall ◽  
Memory Skill

AbstractObjective:To evaluate the 137-item Utah Picture-sort Food-frequency Questionnaire (FFQ) in the measurement of usual dietary intake in older adults.Design:The picture-sort FFQ was administered at baseline and again one year later. Three seasonal 24-hour dietary recall interviews were collected during the year between the two FFQs. Mean nutrient intakes were compared between methods and between administrations of the FFQ.Setting:The FFQ interviews were administered in respondents' homes or care-centres. The 24-hour diet recalls were conducted by telephone interview on random days of the week.Subjects:Two-hundred-and-eight men and women aged 55–84 years were recruited by random sample of controls from a case–control study of nutrition and bone health in Utah.Results:After adjustment for total energy intake, median Spearman rank correlation coefficients between the two picture-sort FFQs were 0.69 for men aged ≤69 years, 0.66 for men aged >69 years; and 0.68 for women aged ≤69 years, 0.67 for women aged >69 years. Median correlation coefficients between methods were 0.50 for men ≤69 years old, 0.52 for men >69 years old; 0.55 for women ≤69 years old, 0.46 for women >69 years old.Conclusions:We report intake correlations between methods and administrations comparable to those reported in the literature for traditional paper-and-pencil FFQs and one other picture-sort method of FFQ. This dietary assessment method may improve ease and accuracy of response in this and other populations with low literacy levels, poor memory skill, impaired hearing, or poor vision.

scholarly journals Concurrent validity of the Sensory Organization Test measures in unilateral transtibial amputees

2012 ◽  
Vol 37 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Prasath Jayakaran ◽  
Gillian M Johnson ◽  
S John Sullivan
Keyword(s):  
Concurrent Validity ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Sensory Organization Test ◽  
Spearman’S Rank Correlation ◽  
Sensory Organization ◽  
Clinical Measures ◽  
Transtibial Amputees ◽  
Lower Limb Amputees ◽  
Strategy Score

Background and Aim: The physical asymmetries associated with a prosthesis raises the question of validity of the Sensory Organization Test (SOT) measures (equilibrium score (ES) and strategy score (SS)) in lower limb amputees. This study explores the validity of these measures in transtibial amputees by correlating with their corresponding centre of pressure (COP) excursion/velocity measures. Technique: Fifteen transtibial amputees (69.5 ± 6.5 years) completed three trials for each of the six SOT conditions. Discussion: The Spearman’s rank correlation coefficients between ESs and global COP excursion/velocity measures ranged from 0.52 to 0.71 for Conditions 1, 4 and 5, 0.79 to 0.85 for Conditions 2 and 3, and 0.39 to 0.43 for Condition 6. The coefficients for SSs ranged between 0.78 and 0.97 for Conditions 1 to 5 and 0.55 to 0.67 for Condition 6. The corresponding sound and prosthetic side COP variables demonstrated varying strengths of association with ES and SS. Clinical relevance Of the two clinical measures examined, the SSs are strongly reflective of COP excursion/velocity measures and these findings have application in the interpretation of SOT when evaluating balance in transtibial amputees.

scholarly journals Toward Capturing the Exposome: Exposure Biomarker Variability and Co-Exposure Patterns in the Shared Environment

2017 ◽  
Author(s):  
Ming Kei Chung ◽  
Kurunthachalam Kannan ◽  
Germaine M. Buck Louis ◽  
Chirag J. Patel
Keyword(s):  
Rank Correlation ◽  
Correlation Coefficients ◽  
Shared Environment ◽  
Specific Factor ◽  
Endocrine Disrupting Chemical ◽  
Spearman’S Rank Correlation ◽  
Exposure Biomarker ◽  
Exposure Patterns ◽  
Household Environment ◽  
Study Participants

AbstractBACKGROUND:Along with time, variation in the exposome is dependent on the location and sex of study participants. One specific factor that may influence exposure co-variations is a shared household environment.OBJECTIVES:To examine the influence of shared household and partner’s sex in relation to the variation in 128 endocrine disrupting chemical (EDC) exposures among couples.METHODS:In a cohort comprising 501 couples trying for pregnancy, we measured 128 (13 chemical classes) persistent and non-persistent EDCs and estimated 1) sex-specific differences; 2) variance explained by shared household; and 3) Spearman’s rank correlation coefficients (rs) for females, males, and couples’ exposures.RESULTS:Sex was correlated with 8 EDCs including polyfluoroalkyl substances (PFASs) (p< 0.05). Shared household explained 43% and 41% of the total variance for PFASs and blood metals, respectively, but less than 20% for the remaining 11 EDC classes. Co-exposure patterns of the exposome were similar between females and males, with within-classrs higher for persistent and lower for non-persistent chemicals. Medianrss of polybrominated compounds and urine metalloids were 0.45 and 0.09, respectively, for females (0.41 and 0.08 for males), whereas lowerrss for these 2 classes were found for couples (0.21 and 0.04).CONCLUSIONS:Overall, sex did not significantly affect EDC levels in couples. Individual, rather than shared environment, could be a major factor influencing the co-variation of 128 markers of the exposome. Correlations between exposures are lower in couples than in individual partners and have important analytical and sampling implications for epidemiological study.

scholarly journals RISK ANALYSIS OF INEFFICIENCY AT UKRAINE’S MACHINE BUILDING ENTERPRISES

2019 ◽  
Vol 2019 (3) ◽  
pp. 22-34
Author(s):  
Maryna AFANASIEVA ◽  
Keyword(s):  
Production Efficiency ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Value Added ◽  
Risk Groups ◽  
Analysis Data ◽  
Risk Identification ◽  
Machine Building ◽  
Distribution Law ◽  
Market Capture

The paper considers the risk identification of inefficiency concerning 51 Ukrainian joint-stock companies of machine building in 2012–2017. The value added at factor cost (VA) is determined as the resulting indicator of production efficiency, which is a source of income of various social groups, so it contributes to combined efforts. To support advanced production and management technologies, rather than an extensive market capture, the multiplicative model of VA has been suggested with the VA share in output to assess the quality processes within the enterprise. Economic analysis of the annual public financial statements and the structural statistics were conducted to study proportion between the cost elements in sum of expenses with link to profit in net turnover for the main operating activity. As a result the models of two types of risk coefficient have been proposed. It has been verified by statistical analysis. Data were checked on submission to normal distribution law by Shapiro – Wilk test and homogeneity by coefficient of variation. With the help of nonparametric analysis of variance by Kruskal – Wallis test and Spearman rank correlation coefficients; it has been proved that risk groups differ from other enterprises and from each other statistically significantly. We conclude that 37% of the sample enterprises are risky; a third of this is the large and medium-sized companies. Advantages of the method in comparison with Ward clusterization were shown. When making decisions about resource allocation, it should be confirmed that the enterprise is risk-free according to algorithms provided. To improve situation it needs to apply sustainable development concept.

Difference of seasonal variation between glycated albumin and glycated haemoglobin

2018 ◽  
Vol 55 (5) ◽  
pp. 583-587 ◽  
Author(s):  
Karin Tanaka ◽  
Shu Meguro ◽  
Masami Tanaka ◽  
Junichiro Irie ◽  
Yoshifumi Saisho ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Plasma Glucose ◽  
Seasonal Variations ◽  
Glycated Albumin ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Glycated Haemoglobin ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Average Temperature

Background Glycated albumin reflects 2–3-week glycaemic controls, and in addition to glycated haemoglobin, it has been used as a glycaemic control indicator. We presumed that glycated albumin also has seasonal variations and is related to temperature, similar to glycated haemoglobin. Methods The subjects were diabetic outpatients from April 2007 to March 2013. This resulted in the enrolment of 2246 subjects and the collection of a total of 53,968 measurements. Mean glycated haemoglobin, glycated albumin, and plasma glucose were calculated for each month over six years. The associations of the measures with each other and the average temperature for each month in Tokyo were assessed using Spearman rank correlation coefficients. Results Plasma glucose was highest in January and lowest in May. Glycated haemoglobin was highest in March and lowest in September. Glycated albumin was highest in May and lowest in December. Glycated albumin tended to have a disjunction with plasma glucose in winter. Glycated haemoglobin had seasonal variation, but glycated albumin did not. Plasma glucose and glycated haemoglobin showed significant negative correlations with temperature (rs = −0.359, P < 0.001, rs = −0.449, P < 0.001, respectively), but glycated albumin did not. However, glycated albumin was inter-correlated with plasma glucose (rs = 0.396, P < 0.001) and glycated haemoglobin (rs = 0.685, P < 0.001), and glycated haemoglobin was inter-correlated with plasma glucose (rs = 0.465, P < 0.001). Conclusion Glycated albumin and glycated haemoglobin showed different seasonal variations from each other over the six-year study period. Thus, further studies to identify factors that contribute to glycated albumin are needed.

MORPHOFUNCTIONAL DETERMINANTS OF THE EFFECTIVENESS OF ONE VERSUS ONE SMALL-SIDED GAMES IN SOCCER PLAYERS

2018 ◽  
Vol 28 (82) ◽  
pp. 45-52
Author(s):  
Janusz Jaworski ◽  
Tadeusz Ambroży ◽  
Dariusz Tchórzewski ◽  
Krzysztof Durlik
Keyword(s):  
Motor Skills ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Training Group ◽  
Rank Test ◽  
Football Players ◽  
Correlation Matrices ◽  
Signed Rank ◽  
Signed Rank Test ◽  
Functional Profiles

Aim. The aim of this report is to identify variables determining the effectiveness of small football games at subsequent stages of training. Material and Methods. The study material comprised the results of tests conducted among 42 football players who were assigned to 3 categories: youngsters, younger juniors and seniors. The scope of the study included basic somatic features, selected motor skills tests and specific coordination tests of motor skills recommended for football players. Detailed correlation matrices were calculated using Spearman’s signed-rank test between all the analysed variables and the overall game perforance index (OPI). For each training group, morpho-functional profiles were calculated taking variables from previous analyses into account. Variables forming the structure of these models were normalised on the T scale. Results. 11 statistically significant Spearman’s signed-rank correlation coefficients were obtained between game performance indices and the analysed variables. In the 3 training groups of football players, considerable diversity of the internal structure of morpho-functional models was noted. In the group of juniors and seniors, differentiation between features was 1.2 of standard deviation. Conclusions. In terms of fitness, the influence of circulatory-respiratory endurance and speed ability on the indicator of overall performance for the seniors’ game was noted. In turn, taking the neuro-functional side of the players’ motor ability into account, correlations with the effectiveness of the game were mainly found within the ability of balance, kinesthetic differentiation and motor adaptation. Such regularities mainly refer to the youngsters and younger juniors.

Abstract P257: Getting to the Golden Hour: Correlating “Door-To” Times with 60-Minute Administration of tPA in an Academic Medical Center

2011 ◽  
Vol 4 (suppl_2) ◽  
Author(s):  
Ann M Leonhardt ◽  
Curtis G Benesch ◽  
Kate C Young
Keyword(s):  
Medical Center ◽  
Academic Medical Center ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Time Frame ◽  
Arrival Times ◽  
Golden Hour ◽  
Stroke Team ◽  
Time Standards ◽  
Scheduling Protocols

Introduction: The efficacy of intravenous tPA for the treatment of acute stroke diminishes over time. The AHA/ASA and NINDS recommend a goal door to needle time of 60 minutes or less. Objective: Identify potential barriers to tPA administration within 60 minutes of arrival. Methods: Retrospective review of tPA adsinistration using “Get With the Guidelines” (GWTG) and institutional records from January 1, 2009 through December 31, 2010 (n=100). Spearman rank correlation coefficients were calculated for the NINDS recommended time standards, age and NIH Stroke Scale (NIHSS) score. We used a receiver-operator curve (ROC) to identify the door to CT time predictive of tPA administration ≤ 60 minutes. Results: Median door to physician, door to CT, and door to stroke team times were within the recommended goals. Door to CT (ρ=0.53, p<0.0001), and door to stroke team (ρ=0.33, p<0.01) times were positively correlated with door to tPA times. Last known well to arrival (ρ= -0.28, p<0.01) and NIHSS (ρ= -0.32, p<0.01) were negatively correlated with door to tPA times; patients with higher NIHSS and longer last-known-well to arrival times received tPA in a shorter time frame. Age and door to physician time were not correlated with tPA treatment times. After adjusting for the other benchmarks and NIHSS, only door to CT remained significantly correlated with door to IV tPA (partial correlation coefficient=0.40, p<0.001). The ROC curve showed that a goal time of 20 minutes or less for door to CT initiation had the best sensitivity and specificity for predicting tPA administration within 60 minutes. Conclusion: In keeping with the recommended time goals, median times for the intermediate steps were within target. Our median tPA times, however, did not meet the 60 minute goal. Door to CT initiation was the variable that most strongly correlated with door to needle times. Process issues such as order entry and scheduling protocols may be barriers to obtaining CT within the 20 minute time frame identified by our analysis. Other barriers after the CT scan is obtained must be identified to facilitate faster tPA administration. Further evaluation of these factors is warranted to better ensure the timely delivery of tPA to stroke patients, thereby improving patient outcomes.

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