scholarly journals The Hyperbolic Method Algorithm for the Optimal Determination of Coordinates and the Evaluation of the Potential Accuracy with Which They Are Measured

2018 ◽  
Author(s):  
Vladimir P. Dubykin ◽  
Konstantin S. Kalashnikov ◽  
Boris V. Matveev ◽  
Oleg V. Chernoyarov
Keyword(s):  
Potential Accuracy ◽  
Hyperbolic Method

scholarly journals Inferring Orthologs: Open Questions and Perspectives

2016 ◽  
Vol 9 ◽  
pp. GEI.S37925 ◽  
Author(s):  
Fredj Tekaia
Keyword(s):  
Genome Duplication ◽  
Potential Accuracy ◽  
Species Phylogeny ◽  
Open Questions ◽  
Orthology Detection ◽  
Genome Content ◽  
Combination Of Methods ◽  
Gain Loss

With the increasing number of sequenced genomes and their comparisons, the detection of orthologs is crucial for reliable functional annotation and evolutionary analyses of genes and species. Yet, the dynamic remodeling of genome content through gain, loss, transfer of genes, and segmental and whole-genome duplication hinders reliable orthology detection. Moreover, the lack of direct functional evidence and the questionable quality of some available genome sequences and annotations present additional difficulties to assess orthology. This article reviews the existing computational methods and their potential accuracy in the high-throughput era of genome sequencing and anticipates open questions in terms of methodology, reliability, and computation. Appropriate taxon sampling together with combination of methods based on similarity, phylogeny, synteny, and evolutionary knowledge that may help detecting speciation events appears to be the most accurate strategy. This review also raises perspectives on the potential determination of orthology throughout the whole species phylogeny.

Determination of transformer HV winding axial displacement extent using hyperbolic method – a feasibility study

2019 ◽  
Vol 13 (7) ◽  
pp. 1004-1013 ◽  
Author(s):  
Hesam Rahbarimagham ◽  
Hossein Karami ◽  
Saeid Esmaeili ◽  
Gevork B. Gharehpetian
Keyword(s):  
Feasibility Study ◽  
Axial Displacement ◽  
Hyperbolic Method

scholarly journals On the experiment validity of the continuous medium motion detection by the waveguide method

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
P. A. Polyanskikh ◽  
◽  
A. A. Meshcheryakov ◽  
V. P. Denisov ◽  
A. A. Geltser
Keyword(s):  
A Priori ◽  
Navigation Systems ◽  
Electronic Warfare ◽  
Potential Accuracy ◽  
Promising Area ◽  
Phase Direction ◽  
The Times ◽  
Priori Information ◽  
Electronic Intelligence

Electronic intelligence is an important element of electronic warfare, which «is not announced and never stops». The purpose of electronic reconnaissance is to detect the emitting radio-electronic means of a potential enemy, to determine its location and radiation parameters using passive (non-emitting equipment). Electronic warfare, even in peacetime, is a promising area of development. The use of passive methods allows work to be carried out covertly, without detection. The peculiarity of the proposed method is that a priori information about the objects that reflected the signal is not required. Determination of the coordinates of the emitter is carried out by determining the delay between the arrival of the direct signal and the set of reflections from the terrain. The use of detailed, for today, satellite maps of the terrain allow with some accuracy to determine the coordinates of reflecting objects on the ground. The coordinates of the receiving point can also be determined with high accuracy using global navigation systems. The data entered the computer and the recording of signals obtained as a result of observing the air allows us to determine the coordinates of the radio emission source. The algorithm proposed in the article allows reducing the number of receiving points to one and using a phase direction finder to determine the direction of signal arrival. Evaluation of the potential accuracy of the method showed the possibility of practical application, while better results can be obtained when improving the algorithm in terms of improving the algorithms for determining the times of arrival of signals, algorithms for their extraction and post-processing of experimental data.

DETERMINATION OF RADIO SOURCES LOCATION BY THE METHOD OF "IMAGINARY BASE" WHEN USING THE LINEAR MODEL

2018 ◽  
pp. 124-130
Author(s):  
Yu. V. Petrov ◽  
S. I. Bakaras ◽  
S. A. Yukhno
Keyword(s):  
Radio Source ◽  
Linear Model ◽  
Source Location ◽  
Time Interval ◽  
Radio Sources ◽  
Time Intervals ◽  
Potential Accuracy ◽  
Long Time ◽  
Geometrical Factors

This article presents the expressions which allow evaluating the potential accuracy of radio source location by the method of «imaginary base» when using the linear model of changing the bearing on it. The concept of the method of «imaginary base» is to be used in solving the triangulation problem not only of measuring bearing, but also their extrapolated values at a certain time interval. Potential characteristics is determined by accuracy, dynamic and geometrical factors, bearing measurement and extrapolation times. The article shows that when using a linear model, there are limitations both on the time of measuring bearing and on the time of extrapolation. It will be because of the increase in the variance of the error of estimating the distance. Limiting of series decomposition members number of non-linear bearing change dependence from time there are. It depends on the speed of changing bearing (depends on the range and speed) and the initial bearing (depends on the track angle). Extrapolation over long time intervals is possible only at long distances and at relatively low speeds.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

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