New Method of Statistical Analysis of Cometary Light-Curves Applied to P/Halley

Stargazers ◽  
1988 ◽  
pp. 153-154
Author(s):  
Serge Thebault
Keyword(s):  
Statistical Analysis ◽  
Light Curves ◽  
New Method

Precursors of short gamma-ray bursts detected by the INTEGRAL observatory

2018 ◽  
Vol 27 (10) ◽  
pp. 1844013 ◽  
Author(s):  
Pavel Minaev ◽  
Alexei Pozanenko ◽  
Sergei Molkov
Keyword(s):  
Statistical Analysis ◽  
Light Curve ◽  
Relative Intensity ◽  
Gamma Ray ◽  
Convincing Evidence ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Upper Limits ◽  
Short Grbs

We have analyzed the light curves of 527 short gamma-ray bursts (GRBs) registered by the SPI-ACS, SPI and IBIS/ISGRI experiments of INTEGRAL observatory totally to search for precursors. Both the light curves of each 527 individual burst and the averaged light curve of 372 brightest SPI-ACS bursts have been analyzed. In a few cases, we have found and investigated precursor candidates using SPI-ACS, SPI and IBIS/ISGRI of INTEGRAL, GBM and LAT of Fermi data. No convincing evidence for the existence of precursors of short GRBs has been found. A statistical analysis of the averaged light curve for the sample of brightest short bursts has revealed no regular precursor. Upper limits for the relative intensity of precursors have been estimated. We show that the fraction of short GRBs with precursors is less than 0.4% of all short bursts, detected by INTEGRAL.

Sex Differences in the Swordtail Xiphophorus hellerii Revealed by a New Method to Investigate Volumetric Data

2020 ◽  
Vol 95 (3-4) ◽  
pp. 127-138
Author(s):  
Michael H. Hofmann
Keyword(s):  
Sex Differences ◽  
Statistical Analysis ◽  
Relative Size ◽  
Volume Ratio ◽  
New Method ◽  
Brain Morphology ◽  
Body Parts ◽  
Swordtail Fish ◽  
Xiphophorus Hellerii ◽  
Matrix Volume

Comparing the relative volumes of body parts is a useful tool in morphology, but it is not trivial to do this in animals that differ in overall size. To account for scaling differences, a “reference size” has to be determined and the original absolute volumes have to be “corrected for” by this scaling reference. However, the outcome of a statistical analysis is greatly affected by this “reference size,” and it is practically impossible to determine the “overall size” of a structure independent of the changes in the relative size of the parts of it. Here, a new method is introduced to compare the relative volumes of parts that does not need a scaling reference. The method transforms the absolute part volumes into a ratio matrix (volume ratio transformation, VRT). The VRT is free of any scaling factors and can be used to compare groups of animals. This paper also reviews various other errors made frequently when comparing brain morphology between animals. Finally, the VRT is applied to investigate sex differences in the swordtail fish <i>(Xiphophorus hellerii)</i>, which show profound differences in the size of the valvula cerebelli.

scholarly journals New Ways to Rotation Rates

1989 ◽  
Vol 107 ◽  
pp. 235-243
Author(s):  
R. E. Wilson
Keyword(s):  
Light Curves ◽  
New Method ◽  
Line Broadening ◽  
Rotation Rates ◽  
Fast Rotating

AbstractProgress in determining rotation rates of Algol primary stars from light curves is assessed. Included are elementary ideas on why the new method works, how to carry out solutions, and how and when to apply the constraint on rotational lobe filling. Some comments are made on desirable improvements for measuring rotation from line broadening. A few remarks are made about the problem of identifying likely fast rotating Algols.

scholarly journals Vertical contact tightness of occlusion comparison between orofacial myalgia patients and asymptomatic controls: a pilot study

2018 ◽  
Vol 46 (12) ◽  
pp. 4952-4964
Author(s):  
Kun Qi ◽  
Yi-Fei Xu ◽  
Shao-Xiong Guo ◽  
Wei Xiong ◽  
Mei-Qing Wang
Keyword(s):  
Statistical Analysis ◽  
Pilot Study ◽  
Orofacial Pain ◽  
New Method ◽  
Occlusal Contact ◽  
Female Patients ◽  
Vertical Contact ◽  
Age And Sex

Objective The association between occlusal contact and orofacial pain remains unclear. The aim of this study was to detect occlusal contact tightness by using a new method and to compare differences between patients and asymptomatic controls. Methods Fifteen female patients with orofacial myalgia and fifteen age- and sex-matched asymptomatic controls were enrolled. Occlusal contacts were recorded by making bite imprints. The numbers, sizes, and distributions of the contacts were detected by making photos of bite imprints after biting. The Mann-Whitney U test and ANOVA were used for statistical analysis. Results In myalgia patients, impact contacts at the molar regions were more frequent, larger in number and area size, and were distributed more on guiding cusps, compared with impact contacts in asymptomatic controls. Conclusion Our new method revealed more prevalent and more severe impact contacts in orofacial myalgia patients, compared with asymptomatic controls.

scholarly journals Variability and transient search in the SUDARE–VOICE field: a new method to extract the light curves

2020 ◽  
Vol 493 (3) ◽  
pp. 3825-3837
Author(s):  
Dezi Liu ◽  
Wenqiang Deng ◽  
Zuhui Fan ◽  
Liping Fu ◽  
Giovanni Covone ◽  
...  
Keyword(s):  
Uncertainty Analysis ◽  
Point Spread Function ◽  
Forthcoming Paper ◽  
Light Curves ◽  
New Method ◽  
Imaging Data ◽  
Point Spread ◽  
Spread Function ◽  
Function Modelling ◽  
The Difference

ABSTRACT The VLT Survey Telescope (VST) Optical Imaging of the CDFS and ES1 Fields Survey, in synergy with the SUDARE survey, is a deep optical ugri imaging of the CDFS and ES1 fields using the VST. The observations for the CDFS field comprise about 4.38 deg2 down to r ∼ 26 mag. The total on-sky time spans over 4 yr in this field, distributed over four adjacent sub-fields. In this paper, we use the multiepoch r-band imaging data to measure the variability of the detected objects and search for transients. We perform careful astrometric and photometric calibrations and point spread function modelling. A new method, referring to as differential running-average photometry, is proposed to measure the light curves of the detected objects. With the method, the difference of PSFs between different epochs can be reduced, and the background fluctuations are also suppressed. Detailed uncertainty analysis and detrending corrections on the light curves are performed. We visually inspect the light curves to select variable objects, and present some objects with interesting light curves. Further investigation of these objects in combination with multiband data will be presented in our forthcoming paper.

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