scholarly journals A Multiepoch Regression Model used in Geodesy

2016 ◽  
Vol 28 (4) ◽  
Author(s):  
Lubomír Kubáček ◽  
Ludmila Kubáčková
Keyword(s):  
Statistical Analysis ◽  
Regression Model ◽  
Practical Importance ◽  
The Other ◽  
Measurement Results ◽  
Replicated Measurements

An investigation of the deformations of large buildings (bridges, dams, etc.) needs replicated measurements in special types of geodetical networks. They are characterized by two groups of points creating the network; one group is formed by points with stable positions and the other one is formed by points located on the building and characterizing its deformations. A statistical analysis of measurement results is done after each epoch ofmeasurement and also after several epochs. It is of a practical importance to develop an algorithm of estimation which enables us to use the partial results obtained after each epoch for results after several epochs.

scholarly journals Bonferroni's and Sidak's modified tests

2006 ◽  
Vol 63 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Armando Conagin ◽  
Décio Barbin
Keyword(s):  
Experimental Data ◽  
Statistical Analysis ◽  
Null Hypothesis ◽  
Practical Importance ◽  
The Other ◽  
Type I ◽  
Test Type ◽  
The Mean ◽  
Mean Differences

Results of practical importance had been discarded testing formulated hypothesis with the aid of statistical analysis of experimental data because of the power of the utilized test. This study compares the power of two Bonferroni's Modified and one Sidak's Modified tests with known tests analyzing 1200 simulated experiments. All differences of means were obtained in relation to the mean of the adopted control to guarantee parametrical magnitude of mean differences. Student's test (type I comparisonwise error) and Waller-Duncan's (Bayesian error) showed the highest percentage of significative differences, followed by Duncan's, BM2, SiM, BM1, DunnettU's, SiN, BN, Dunnettu's, SNK's, REGWF's, REGWQ's, Tukey's, Sidak's and Bonferroni's tests. For differences equal to zero, Student's and Waller-Duncan's test exhibit 5% frequency of rejection of the null hypothesis, in accordance the nominal error I adopted (alpha = 0.05). All other tests had values below 0.05, generally ranging on 0.01 to 0.02 or less. Depending of the number of zero differences and considering the type I experimentwise error I, Student's, Waller-Duncan's and Duncan's tests showed crescent values of errors (> 0.05), proportional to the number of null differences included in the experiment; all other tests exhibit showed of type I experimentwise error < 0.05, most nearing 0.01-0.02 or less. Efficiency of the three "Modified Tests" was close to DunnettU's test, but higher than the other testes of type I experimentwise error nature (MEER).

scholarly journals Proposal of an Adaptive Neurofuzzy System to Control Flow Power in Distributed Generation Systems

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Helbert Eduardo Espitia ◽  
Iván Machón-González ◽  
Hilario López-García ◽  
Guzmán Díaz
Keyword(s):  
Statistical Analysis ◽  
Distributed Generation ◽  
Distribution System ◽  
Voltage Control ◽  
Control Flow ◽  
The Other ◽  
Charge Variation ◽  
Flow Power ◽  
Dynamics Identification ◽  
Neurofuzzy Systems

Systems of distributed generation have shown to be a remarkable alternative to a rational use of energy. Nevertheless, the proper functioning of them still manifests a range of challenges, including both the adequate energy dispatch depending on the variability of consumption and the interaction between generators. This paper describes the implementation of an adaptive neurofuzzy system for voltage control, regarding the changes observed in the consumption within the distribution system. The proposed design employs two neurofuzzy systems, one for the plant dynamics identification and the other for control purposes. This focus optimizes the controller using the model achieved through the identification of the plant, whose changes are produced by charge variation; consequently, this process is adaptively performed. The results show the performance of the adaptive neurofuzzy system via statistical analysis.

Was This in Your Statistics Textbook? IV. Frequency Data

1989 ◽  
Vol 25 (1) ◽  
pp. 11-25
Author(s):  
D. J. Finney
Keyword(s):  
Statistical Analysis ◽  
Contingency Tables ◽  
The Other ◽  
Frequency Data ◽  
Significance Tests ◽  
Test Statistic ◽  
Jumping To Conclusions ◽  
Proper Role ◽  
Measure Of Association

SUMMARYObservations that are frequencies rather than measurements often call for special types of statistical analysis. This paper comments on circumstances in which methods for one type of data can sensibly be used for the other. A section on two-way contingency tables emphasizes the proper role of χ2 a test statistic but not a measure of association; it mentions the distinction between one-tail and two-tail significance tests and reminds the reader of dangers. Multiway tables bring new complications, and the problems of interactions when additional classificatory factors are explicit or hidden are discussed at some length. A brief outline attempts to show how probit, logit, and similar techniques are related to the analysis of contingency tables. Finally, three unusual examples are described as illustrations of the care that is needed to avoid jumping to conclusions on how frequency data should be analysed.

Changes in Nutrient Levels of Lake Water Stored at 4 °C

1984 ◽  
Vol 41 (6) ◽  
pp. 985-988 ◽  
Author(s):  
A. H. El-Shaarawi ◽  
M. A. Neilson
Keyword(s):  
Statistical Analysis ◽  
Lake Water ◽  
Water Samples ◽  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
The Other ◽  
Nutrient Levels ◽  
Glass Bottles ◽  
Reactive Phosphorus

Water samples were collected on Lake Ontario during April and November, filtered (0.45 μm), and immediately analyzed onboard ship for the nutrients soluble reactive phosphorus, nitrate-plus-nitrite, and ammonia. Replicates were stored in glass bottles at 4 °C and reanalyzed within 8 d. Statistical analysis showed that soluble reactive phosphorus decreased by 11 and 13% and nitrate-plus-nitrite by 7 and 6%, whereas ammonia increased by 75% on one cruise and decreased by 37% on the other.

THE INFLUENCE OF FAIR COMPETITION ON THE MANAGEMENT OF PUBLIC UNDERTAKINGS

2013 ◽  
Vol 8 (1) ◽  
pp. 42-54
Author(s):  
Camille Carbonnaux
Keyword(s):  
A Priori ◽  
Practical Importance ◽  
Competition Law ◽  
Legal Aspects ◽  
The Other ◽  
Common Features ◽  
Fair Competition ◽  
Management Perspective ◽  
The Common ◽  
European Competition Law

Since the 1990s, European judicial and normative institutions have paid particular attention to the competitive practices of public undertakings. Consequently, their regime is governed by a significant number of rules pursuing objectives appearing, a priori, contradictory. In fact, public undertakings may experience difficulties in their management. In this context, an approach of public competition law through the prism of fair competition can be very useful. Regarding the uniformity of its judgment, fair competition appears as an objective capable of coordinating rules and overcoming their contradictions. It thereby offers a global and coherent reading plan of all the legal translations of the European competitive order being of some practical importance. In illuminating the common features of the different legal aspects of competition, we can easily switch from one to the other. It therefore makes the European approach to competition more accessible and understandable. Furthermore, and most importantly, it leads to identifying legal opportunities and threats in a cross-disciplinary way. So, from a “Law & Management” perspective, it appears to be a precious tool for the management of public undertakings. Key words: European competition law, public undertakings, fair competition, “Management & law”.

scholarly journals Hypermobility and sports injury

2018 ◽  
Vol 4 (1) ◽  
pp. e000366 ◽  
Author(s):  
Joseph Alexander Nathan ◽  
Kevin Davies ◽  
Ian Swaine
Keyword(s):  
Statistical Analysis ◽  
Sports Injury ◽  
The Other ◽  
Anecdotal Evidence ◽  
Demographic Information ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Exact Test ◽  
Joint Dislocation ◽  
Ligament Sprain

ObjectiveTo determine whether there is an association between hypermobility and sports injury.MethodsA quantitative observational approach using a cross-sectional survey was adopted. Individuals were identified as hypermobile or not. All participants were asked to complete two questionnaires: one asking demographic information and the other injury-specific. Fisher’s exact test was used for statistical analysis.Results114 individuals participated in the study, 62 women and 52 men. 26% of the participants were hypermobile. There was no significant association between hypermobility and sports injury (p=0.66). There was a significant increase in joint and ligament sprain among the non-hypermobile (NH) group covering all sports (p=0.03). Joint dislocation was found exclusively among hypermobile individuals. The duration of injury in hypermobile individuals was higher than NH. The use of oral painkillers or anti-inflammatories in the semiprofessional group was greater than the general population.ConclusionHypermobility is relatively common among individuals, and there is a lot of anecdotal evidence associating it with increased rates of injuries. This project finds that NH individuals are more likely to sustain a ligament or joint sprain in sports. This is due to increased joint laxity and flexibility preventing injury. There were important limitations to this study which will be addressed in further work. These include assessing for pauciarticular hypermobility and focusing on one sport to investigate its association with sports injury in those who are hypermobile or not. It would also be important to focus on one specific joint, assessing its flexibility and association with injury.

scholarly journals The Influence of Design Parameters on Straight Bevel Gear Dynamics

2015 ◽  
Vol 5 (2) ◽  
pp. 114
Author(s):  
Chiu-Fan Hsieh ◽  
You-Qing Zhu
Keyword(s):  
Statistical Analysis ◽  
The Other ◽  
Design Parameters ◽  
Bevel Gears ◽  
Straight Bevel Gear ◽  
Pressure Angle ◽  
Stress Fluctuation ◽  
Shaft Angle ◽  
Statistical Results ◽  
Component Force

<p class="1Body">This study analyzes the influence of design parameters on the dynamics of straight bevel gears by constructing a model that allows variation in the shaft angle, pressure angle, and backlash. According to the statistical analysis, the order of influence of these parameters on weight is shaft angle &gt; pressure angle &gt; backlash. When the shaft angle is 90°, the statistical results show the drive is stable and the stress fluctuation level is low. The pressure angle, on the other hand, can affect the gear’s dynamic property by influencing the driving component force on the gear and the component force on the shaft. The results for the shaft and pressure angles are used to determine the appropriate backlash. Overall, the analysis not only provides designers with an important reference but explains the dominance in the market of gear designs with a 90° shaft angle and a 20° pressure angle.</p>

Statistics and Economic History

1941 ◽  
Vol 1 (1) ◽  
pp. 26-41 ◽  
Author(s):  
Simon Kuznets
Keyword(s):  
Statistical Analysis ◽  
Economic History ◽  
Raw Materials ◽  
The Other ◽  
Economic Study ◽  
Statistical Research ◽  
Historical Approach ◽  
The Past ◽  
Economic Inquiry ◽  
Analytical Tools

This paper deals with the relation between statistical analysis as applied in economic inquiry and history as written or interpreted by economic historians. Although both these branches of economic study derive from the same body of raw materials of inquiry—the recordable past and present of economic society—each has developed in comparative isolation from the other. Statistical economists have failed to utilize adequately the contributions that economic historians have made to our knowledge of the past; and historians have rarely employed either the analytical tools or the basic theoretical hypotheses of statistical research. It is the thesis of this essay that such failure to effect a close interrelation between historical approach and statistical analysis needs to be corrected in the light of the final goal of economic study.

scholarly journals Aferição do pH de diferentes agentes clareadores indicados para o clareamento intracoronário

2018 ◽  
Author(s):  
João Felipe Besegato ◽  
Gabriela Dos Santos Ribeiro Rocha ◽  
Marlene De Sousa Amorim ◽  
Fabio Martins Salomão ◽  
Daniel Poletto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Statistical Analysis ◽  
Multiple Comparisons ◽  
The Other ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Friedman Test ◽  
Time Intervals ◽  
Ph Values ◽  
Evaluation Time

Objective: to measure pH values of bleaching agents that are indicated to intracoronal bleaching technique in different time intervals. Methods: Each group (G) received five samples (n=5): G1 – distilled water (AD); G2 – hydrogen peroxide (H2O2) 30%; G3 – sodium perborate (PbS) + AD; G4 – PbS + H2O2 30%; G5 – sodium percarbonate (PcS) + AD; and G6 – PcS + H2O2 30%. pH values were stated using a digital pHmeter, in different time intervals: immediately after handling (T0), 24 hours (T1) and 168 hours after handling (T2). The results were submitted to statistical analysis through Kruskal-Wallis and Mann Whitney tests, in this order, allowing multiple comparisons among the groups. To verify the effect of time in each group, Friedman test was applied. Results: In the evaluation of the effect of time in each group, it was observed that G2 presented acid behavior, while the other groups exhibited values close to neutrality or alkaline. Conclusions: H2O2 30% was the only agent that showed acidic behavior in every evaluation time. Meanwhile, PcS + H2O had the highest pH values.

scholarly journals Plaque removal by manual and electric toothbrushing among children

2001 ◽  
Vol 15 (4) ◽  
pp. 296-301 ◽  
Author(s):  
Carolina Covolo da COSTA ◽  
Luiz Cesar da COSTA FILHO ◽  
Marina Lara SÓRIA ◽  
Ana Paula Rorato MAINARDI
Keyword(s):  
Statistical Analysis ◽  
Primary Dentition ◽  
The Other ◽  
Mixed Dentition ◽  
Plaque Removal ◽  
Other Hand ◽  
Electric Toothbrush ◽  
Plaque Control ◽  
First Session

The purpose of this study was to compare the effectiveness of plaque control performed with electric and manual toothbrushes. Fifteen children with primary dentition and 14 children with mixed dentition were divided in two groups and randomly assigned to utilize a manual or an electric toothbrush. In the first session, professional plaque removal was performed, and the children spent 24 hours without brushing their teeth. In the second session, plaque was disclosed and assessed on all facial and lingual surfaces. After that, all children brushed their teeth with the predetermined toothbrush. The next procedure was the disclosure and measurement of residual plaque. After a period of 7 days, the children switched the kind of toothbrush, and the same procedures were repeated. According to the statistical analysis of the results, there were no significant differences concerning plaque removal when the toothbrushes were utilized by children with mixed dentition. On the other hand, the electric toothbrush promoted significantly greater plaque removal on the lingual surfaces of teeth from children with primary dentition.

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