Averaging Trials Versus Averaging Trial Peaks: Impact on Study Outcomes

2017 ◽  
Vol 33 (3) ◽  
pp. 233-236 ◽  
Author(s):  
Kevin D. Dames ◽  
Jeremy D. Smith ◽  
Gary D. Heise
Keyword(s):  
Phase Shift ◽  
Average Data ◽  
Paired Samples ◽  
Individual Trial ◽  
Dependent Variables ◽  
Data Points ◽  
Multiple Trials ◽  
Average Profile ◽  
Better Than ◽  
Peak Value

Gait data are commonly presented as an average of many trials or as an average across participants. Discrete data points (eg, maxima or minima) are identified and used as dependent variables in subsequent statistical analyses. However, the approach used for obtaining average data from multiple trials is inconsistent and unclear in the biomechanics literature. This study compared the statistical outcomes of averaging peaks from multiple trials versus identifying a single peak from an average profile. A series of paired-samples t tests were used to determine whether there were differences in average dependent variables from these 2 methods. Identifying a peak value from the average profile resulted in significantly smaller magnitudes of dependent variables than when peaks from multiple trials were averaged. Disagreement between the 2 methods was due to temporal differences in trial peak locations. Sine curves generated in MATLAB confirmed this misrepresentation of trial peaks in the average profile when a phase shift was introduced. Based on these results, averaging individual trial peaks represents the actual data better than choosing a peak from an average trial profile.

scholarly journals Hermitizing the HAL QCD potential in the derivative expansion

2020 ◽  
Vol 2020 (2) ◽  
Author(s):  
Sinya Aoki ◽  
Takumi Iritani ◽  
Koichi Yazaki
Keyword(s):  
Phase Shift ◽  
Wave Functions ◽  
Leading Order ◽  
Many Body ◽  
Derivative Expansion ◽  
Local Part ◽  
Scattering Phase ◽  
Many Body Systems ◽  
Local Term ◽  
Better Than

Abstract A formalism is given to hermitize the HAL QCD potential, which needs to be non-Hermitian except for the leading-order (LO) local term in the derivative expansion as the Nambu– Bethe– Salpeter (NBS) wave functions for different energies are not orthogonal to each other. It is shown that the non-Hermitian potential can be hermitized order by order to all orders in the derivative expansion. In particular, the next-to-leading order (NLO) potential can be exactly hermitized without approximation. The formalism is then applied to a simple case of $\Xi \Xi (^{1}S_{0}) $ scattering, for which the HAL QCD calculation is available to the NLO. The NLO term gives relatively small corrections to the scattering phase shift and the LO analysis seems justified in this case. We also observe that the local part of the hermitized NLO potential works better than that of the non-Hermitian NLO potential. The Hermitian version of the HAL QCD potential is desirable for comparing it with phenomenological interactions and also for using it as a two-body interaction in many-body systems.

scholarly journals Do family firms perform better: A Belgian survey

2007 ◽  
Vol 4 (4) ◽  
pp. 173-182
Author(s):  
Christiane Bughin ◽  
Olivier Colot ◽  
Karin Comblé
Keyword(s):  
Agency Theory ◽  
Empirical Evidence ◽  
Ownership Structure ◽  
Family Firms ◽  
Management Practices ◽  
Family Values ◽  
Economic Literature ◽  
Paired Samples ◽  
Better Than

A large conceptual economic literature presents assumptions that family owned and controlled firms perform better than others, essentially on the basis of agency theory, ownership structure, cultural specificities and particular management practices. Large empirical evidence has been supplied by various studies, even if there are still contradictory debates. This paper uses the paired samples methodology to compare operational, economic and financial profitabilities of Belgian family firms. Evidence is given that they perform better, and this significantly for economic profitability. Discussion is engaged about the contribution of family values and practices to their results.

scholarly journals COMPARISON OF FUZZY SUBTRACTIVE CLUSTERING AND FUZZYC-MEANS

Kursor ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Annisa Eka Haryati ◽  
Sugiyarto Sugiyarto ◽  
Rizki Desi Arindra Putri
Keyword(s):  
Principal Component Analysis ◽  
Fuzzy Clustering ◽  
Principal Component ◽  
Large Data ◽  
Component Analysis ◽  
Subtractive Clustering ◽  
Validity Index ◽  
Fuzzy Clustering Method ◽  
Dependent Variables ◽  
Better Than

Multivariate statistics have related problems with large data dimensions. One method that can be used is principal component analysis (PCA). Principal component analysis (PCA) is a technique used to reduce data dimensions consisting of several dependent variables while maintaining variance in the data. PCA can be used to stabilize measurements in statistical analysis, one of which is cluster analysis. Fuzzy clustering is a method of grouping based on membership values ​​that includes fuzzy sets as a weighting basis for grouping. In this study, the fuzzy clustering method used is Fuzzy Subtractive Clustering (FSC) and Fuzzy C-Means (FCM) with a combination of the Minkowski Chebysev distance. The purpose of this study was to compare the cluster results obtained from the FSC and FCM using the DBI validity index. The results obtained indicate that the results of clustering using FCM are better than the FSC.

scholarly journals Rapid Oscillations in DQ Her and UX Uma

1979 ◽  
Vol 53 ◽  
pp. 518-518
Author(s):  
Jacobus A. Petterson
Keyword(s):  
Phase Shift ◽  
Inclination Angle ◽  
Phase Stability ◽  
White Dwarf ◽  
Front Side ◽  
Classical Nova ◽  
Nonradial Pulsation ◽  
Color Emission ◽  
Better Than ◽  
Related Phase

Although the novalike variable UX UMa strongly resembles the classical nova DQ Her in color, emission spectrum, and optical lightcurve, the properties of the rapid oscillations in both systems are quite different. The oscillations differ in period, amplitude, and phase stability, but most remarkably they differ in the characteristics of the “eclipse related phase shift.” The phase shift in DQ Her is explainable by partial obscuration of the disk during eclipse, together with the idea that the oscillating light does not reach us directly from the white dwarf, but is reflected by the disk. It comes from a rotating UV beam originating near the white dwarf surface, which is reflected better by the backside of the disk than by the front side. We show that the phase shift in UX UMa is explainable by the same model, viewed at a different inclination angle i, if it is assumed that at this value of i reflection from the frontside of the disk is better than from the backside. There may be different ways to accomplish this preference. The results suggest that no retrograde rotation of the white dwarf (or retrogradely rotating nonradial pulsation) is needed to explain UX UMa’s eclipse related phase shift. These phase shifts provide a new (and quite accurate) way to determine a system’s inclination angle. Specific predictions are made for the behaviour of amplitude and phase of the oscillations in other eclipsing systems.

scholarly journals Modeling and Formulation of a Novel Microoptoelectromechanical Gyroscope

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Bohua Sun ◽  
Bo Zhang ◽  
Mohamed Toriq Khan
Keyword(s):  
Phase Shift ◽  
Measurement Technique ◽  
Measurement System ◽  
Proposed Model ◽  
The World ◽  
Innovative Model ◽  
First Time ◽  
Sagnac Gyroscope ◽  
Novel Design ◽  
Better Than

This paper proposed a novel design of microgyroscope based on MEMS structures and optic interferometric microdisplacement measurement technique. The gyroscope consists of microvibrator and interferometric readout. Using Coriolis force, the vibrator transfers the system rotation into a forced vibration; the induced vibration can be sensed by the interferometric microdisplacement measurement system. The optic measurement system has two mirrors which will reflect two rays into a detector. The comprehensive studies on the formulation and analysis of the proposed gyroscope have been undertaken; two key sensor equations have been derived in the first time in the world: (1) relation between rotation and phase shift of lightΔφ=(4πl0/λ)+(8π/λ)(xmax⁡Qy/ωy)Ω(t)sin⁡(ωdt), (2) relation between rotation and interferometric intensity of lightI(t)≈(8π/λ)(xmax⁡Qy/ωy)Ω(t)sin⁡(ωdt)sin⁡(4πl0/λ). The comparison of the proposed gyroscope and well-know Sagnac formulation has been investigated; it shown that the proposed model is much better than Sagnac ones. The new model has finally get rid of needing very long fiber in the case of Sagnac gyroscope. The innovative model gives a new hope to fabricate high accurate and cheaper gyroscope. To date, the proposed gyroscope is the most accurate gyroscope.

Experimental Study and Models Comparison for Solute Transport through Riparian Zones

2014 ◽  
Vol 1073-1076 ◽  
pp. 1604-1608
Author(s):  
Zhou Chen ◽  
Jin Guo Wang ◽  
Wen Zhang Zhang ◽  
Jia Hui Shi
Keyword(s):  
Solute Transport ◽  
Riparian Zone ◽  
Tracer Tests ◽  
Breakthrough Curves ◽  
Advection Dispersion ◽  
Early Arrival ◽  
Models Comparison ◽  
Silt Layer ◽  
Better Than ◽  
Peak Value

Solute transport through riparian zone was studied experimentally and numerically with the consideration of silt layer. The silt layer had markable change on flow field and lead to a significant variation of the breakthrough curves (BTCs). BTCs of solute tracer tests show non-Fickian features as early arrival of peak value and long tailings. BTCs were fitted by advection dispersion equation (ADE), mobile and immobile model (MIM) and the continuous time random walk (CTRW) models. MIM and CTRW can fit BTCs better than ADE and MIM fit better on the capture of the peak value and CTRW fit better in description of the long tailing.

Binocular interaction in the optokinetic system of the crab Carcinus maenas (L.): Optokinetic gain modified by bilateral image flow

1993 ◽  
Vol 10 (5) ◽  
pp. 873-885 ◽  
Author(s):  
Hans-Ortwin Nalbach ◽  
Peter Thier ◽  
Dezsö Varjú
Keyword(s):  
Eye Movements ◽  
Phase Shift ◽  
Carcinus Maenas ◽  
The Other ◽  
Rotational Component ◽  
Control Loop ◽  
Optokinetic System ◽  
Image Flow ◽  
Binocular Interaction ◽  
Better Than

AbstractWe recorded optokinetic eye movements of the crab, Carcinus maenas, in split-drum experiments. The patterns were either oscillated in antiphase on both sides mimicking translational image flow or they were oscillated in phase producing rotational image flow. Eye movements elicited by the rotational stimulus were larger than those produced by the pseudotranslational pattern movements. The smaller response to the latter is mainly a consequence of binocular interaction, the strength of which depends on both the phase-shift and amplitude of pattern oscillation. We develop two hypotheses to explain our results: either (1) signals from each eye modify the gain of the linkage signals coming from the other eye, or (2) the signals coming from the other eye modify the gain of the control loop itself. Quantitative evaluation of the data favors the second of these two hypotheses, which comprises the models of Barnes and Horridge (1969) and Nalbach et al. (1985). In addition, we found that it is the signals from the two slow channels of the crab's movement-detecting system that are transferred from one eye to the other, while signals of the fastest channel act almost exclusively ipsilaterally. We discuss our results as an adaptation by which an animal with panoramic vision compensates exclusively the rotational component of image flow during locomotion. The fact that freely walking crabs distinguish the two components of image flow better than restrained crabs indicates that further visual and nonvisual signals help to disentangle image flow.

scholarly journals Comparative study between Fenton and Intergrowth 21 charts in a sample of Lebanese premature babies

2020 ◽  
Author(s):  
Marie Samarani ◽  
Gianna Restom ◽  
Joelle Mardini ◽  
Georges Abi Fares ◽  
Souheil Hallit ◽  
...  
Keyword(s):  
National Level ◽  
University Hospital ◽  
Growth Chart ◽  
Growth Charts ◽  
Anthropometric Data ◽  
Prenatal Growth ◽  
Premature Babies ◽  
Dependent Variables ◽  
A Prospective Study ◽  
Better Than

Abstract Background: Different charts are used to assess premature growth. The Fenton chart, based on prenatal growth, was used in in the intensive care unit of the Notre Dame des Secours University Hospital to assess premature newborns’ development. Intergrowth21 is a new multidisciplinary, multiethnic growth chart better adapted to premature growth. Our objective was to compare both charts Fenton and Intergrowth21 in order to implement Intergrowth in our unit.Methods: We analyzed 318 files of premature babies born who were admitted to the NICU from 2010 till 2017. Anthropometric data (weight, height and head circumference) converted to percentiles was filled on both charts from birth till 1 month of age.Results: The results of the linear regression taking the weight at birth as the dependent variable, showed that the Fenton scale (R2=0.391) would predict the weight at birth better than the Intergrowth 21 scale (R2=0.257). The same applies for the height at birth and cranial perimeter at birth when taken as dependent variables. When considering the weight and height at 2 weeks, the results showed that the Intergrowth 21 scale would predict those variables better than the Fenton scale, with higher R2 values higher in favor of the Intergrowth 21 scale for both weight (0.384 vs 0.311) and height (0.650 vs 0.585). At 4 weeks, the results showed that the Fenton scale would predict weight (R2=0.655 vs 0.631) and height (R2=0.710 vs 0.643) better than the Intergrowth 21 scale. The results obtained are adjusted over the newborns’ sociodemographic and clinical factors.Conclusion:The results of our study are controversial where the Fenton growth charts are superior to Intergrowth 21 before two weeks of age and at 4 weeks, whereas Intergrowth 21 charts showed higher percentiles for weight and height than Fenton charts at 2 two weeks of age. Further studies following a different design, such as a clinical trial or a prospective study, and conducted in multiple centers should be considered to enroll a more representative Lebanese sample of children and be able to extrapolate our results to the national level.

scholarly journals A Novel Recursive Non-Parametric DBSCAN Algorithm for 3D Data Analysis with an Application in Rockfall Detection

2021 ◽  
Vol 16 (4) ◽  
pp. 579-587
Author(s):  
Pitisit Dillon ◽  
Pakinee Aimmanee ◽  
Akihiko Wakai ◽  
Go Sato ◽  
Hoang Viet Hung ◽  
...  
Keyword(s):  
Point Cloud ◽  
Crack Detection ◽  
Spatial Clustering ◽  
Point Clouds ◽  
Divide And Conquer ◽  
Dbscan Algorithm ◽  
3D Data ◽  
Data Points ◽  
Clustering Data ◽  
Better Than

The density-based spatial clustering of applications with noise (DBSCAN) algorithm is a well-known algorithm for spatial-clustering data point clouds. It can be applied to many applications, such as crack detection, rockfall detection, and glacier movement detection. Traditional DBSCAN requires two predefined parameters. Suitable values of these parameters depend upon the distribution of the input point cloud. Therefore, estimating these parameters is challenging. This paper proposed a new version of DBSCAN that can automatically customize the parameters. The proposed method consists of two processes: initial parameter estimation based on grid analysis and DBSCAN based on the divide-and-conquer (DC-DBSCAN) approach, which repeatedly performs DBSCAN on each cluster separately and recursively. To verify the proposed method, we applied it to a 3D point cloud dataset that was used to analyze rockfall events at the Puiggcercos cliff, Spain. The total number of data points used in this study was 15,567. The experimental results show that the proposed method is better than the traditional DBSCAN in terms of purity and NMI scores. The purity scores of the proposed method and the traditional DBSCAN method were 96.22% and 91.09%, respectively. The NMI scores of the proposed method and the traditional DBSCAN method are 0.78 and 0.49, respectively. Also, it can detect events that traditional DBSCAN cannot detect.

scholarly journals Outperforming Peers Through A Comprehensive Climate Change Strategy: The Case of Electric Utilities

1970 ◽  
Vol 35 (2) ◽  
pp. 1-28
Author(s):  
Edeltraud Guenther ◽  
Alexandra Schmidt ◽  
Anne Bergmann ◽  
Julia Hilmann
Keyword(s):  
Climate Change ◽  
Financial Performance ◽  
Electric Utilities ◽  
Change Strategies ◽  
Change Strategy ◽  
Corporate Managers ◽  
Paired Samples ◽  
Corporate Context ◽  
Combat Climate Change ◽  
Better Than

Firms increasingly aim to combat climate change. For corporate managers,the question whether a related strategy affects financial performance arises. Sinceempirical research on this topic is rather sparse, this study investigates whetherpursuing a corporate climate change strategy leads to better corporate financialperformance. By applying paired samples t-tests, a sample of 62 companies fromthe electric utilities sector matched in pairs is investigated over a five-year timespan. Results indicate that firms with a comprehensive climate change strategypredominantly perform significantly better than their competitors without such astrategy. These findings might contribute to promoting climate change strategies ina corporate context.

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