Security-Oriented Indoor Robots Tracking: An Object Recognition Viewpoint

Indoor robots, in particular AI-enhanced robots, are enabling a wide range of beneficial applications. However, great cyber or physical damages could be resulted if the robots’ vulnerabilities are exploited for malicious purposes. Therefore, a continuous active tracking of multiple robots’ positions is necessary. From the perspective of wireless communication, indoor robots are treated as radio sources. Existing radio tracking methods are sensitive to indoor multipath effects and error-prone with great cost. In this backdrop, this paper presents an indoor radio sources tracking algorithm. Firstly, an RSSI (received signal strength indicator) map is constructed based on the interpolation theory. Secondly, a YOLO v3 (You Only Look Once Version 3) detector is applied on the map to identify and locate multiple radio sources. Combining a source’s locations at different times, we can reconstruct its moving path and track its movement. Experimental results have shown that in the typical parameter settings, our algorithm’s average positioning error is lower than 0.39 m, and the average identification precision is larger than 93.18% in case of 6 radio sources.

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Bulk Relativistic Motion in a Complete Sample of Radio Selected AGN

Symposium - International Astronomical Union ◽

10.1017/s007418090015524x ◽

1987 ◽

Vol 121 ◽

pp. 287-293

Author(s):

C.J. Schalinski ◽

P. Biermann ◽

A. Eckart ◽

K.J. Johnston ◽

T.Ph. Krichbaum ◽

...

Keyword(s):

Dynamic Range ◽

Radio Sources ◽

Relativistic Motion ◽

Complete Sample ◽

Superluminal Motion ◽

Spectrum Radio ◽

Wide Range ◽

Show Evidence

A complete sample of 13 flat spectrum radio sources is investigated over a wide range of frequencies and spatial resolutions. SSC-calculations lead to the prediction of bulk relativistic motion in all sources. So far 6 out of 7 sources observed with sufficient dynamic range by means of VLBI show evidence for apparent superluminal motion.

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Extragalactic jets as probes of distant clusters of galaxies and the clusters occupied by bent radio AGN (COBRA) survey

Proceedings of the International Astronomical Union ◽

10.1017/s1743921315002410 ◽

2014 ◽

Vol 10 (S313) ◽

pp. 315-320

Author(s):

Elizabeth L. Blanton ◽

Rachel Paterno-Mahler ◽

Joshua D. Wing ◽

M. L. N. Ashby ◽

Emmet Golden-Marx ◽

...

Keyword(s):

Radio Galaxies ◽

Radio Sources ◽

Clusters Of Galaxies ◽

Wide Range ◽

Extragalactic Jets ◽

Large Survey ◽

Kinetic Mode ◽

Group Environments ◽

Initial Results ◽

Quasars And Radio Galaxies

AbstractWe are conducting a large survey of distant clusters of galaxies using radio sources with bent jets and lobes as tracers. These radio sources are driven by AGN and achieve their bent morphologies through interaction with the surrounding gas found in clusters of galaxies. Based on low-redshift studies, these types of sources can be used to identify clusters very efficiently. We present initial results from our survey of 653 bent-double radio sources with optical hosts too faint to appear in the SDSS. The sample was observed in the infrared with Spitzer, and it has revealed ~200 distant clusters or proto-clusters in the redshift range z ~ 0.7 - 3.0. The sample of bent-doubles contains both quasars and radio galaxies enabling us to study both radiative and kinetic mode feedback in cluster and group environments at a wide range of redshifts.

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Bulk Relativistic Motion in a Complete Sample of Flat Spectrum Radio Sources

Symposium - International Astronomical Union ◽

10.1017/s0074180900133972 ◽

1988 ◽

Vol 129 ◽

pp. 71-72

Author(s):

C. J. Schalinski ◽

A. Witzel ◽

Th.P. Krichbaum ◽

C. A. Hummel ◽

P. L. Biermann ◽

...

Keyword(s):

Flux Density ◽

Status Report ◽

Radio Sources ◽

Supporting Evidence ◽

X Rays ◽

Relativistic Motion ◽

Bl Lac Objects ◽

Vlbi Observations ◽

Wide Range ◽

5 Ghz

As part of a multi-epoch and multi-wavelength study of the physics of core dominated radio sources we have investigated the occurrence of apparent superluminal motion and other indications for bulk relativistic motion (b.r.m) in a statistically complete, flux density limited (S5GHz ≥ 1Jy) sample of 13 objects with flat radio spectra These sources come from the S5-survey (Kühr et al., 1981) and are optically identified as 7 quasars and 6 BL-Lac objects. They have been observed over a wide range of frequencies, from radio through X-rays (s. Eckart et al., 1986 and references therein). Radiomaps have been obtained at frequencies from 327 MHz to 22.2 GHz with resolutions from arcseconds to 0.2 mas, using the VLA, MERLIN and telescopes of the US- and European-VLBI networks. A recent status report on the VLBI-observations is given by Witzel (1987). In this paper we summarize the results on the direct evidence for b.r.m. in this sample as derived from repeated VLBI-observations at 5 GHz, as well as supporting evidence from SSC-calculations and flux density variability of the 5GHz VLBI core components (Table 1).

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Radio Source Environments at Redshifts > 0.5

Symposium - International Astronomical Union ◽

10.1017/s0074180900080943 ◽

1996 ◽

Vol 175 ◽

pp. 321-322

Author(s):

M. Lacy ◽

S. Rawlings ◽

M. Wold ◽

A. Bunker ◽

K.M. Blundell ◽

...

Keyword(s):

Radio Source ◽

High Redshift ◽

Elliptical Galaxies ◽

Radio Sources ◽

Powerful Radio ◽

Host Galaxies ◽

Local Universe ◽

Wide Range ◽

Age Of The Universe ◽

The Universe

The most powerful radio sources in the local Universe are found in giant elliptical galaxies. Looking back to a redshift of 0.5 (≈ half the age of the Universe for ω = 1), we see that these host galaxies are increasingly found in moderately rich clusters. This fact gives us hope that radio sources can be used as tracers of high density environments at high redshift. By exploiting radio source samples selected over a wide range in luminosity (Blundell et al., these proceedings), we will also be able to test whether the luminosities of radio sources are correlated with their environments.

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The geophysical investigation of Quaternary geological environments

Geological Society London Engineering Geology Special Publications ◽

10.1144/gsl.eng.1991.007.01.54 ◽

1991 ◽

Vol 7 (1) ◽

pp. 555-562

Author(s):

S. Penn

Keyword(s):

Western Europe ◽

Geophysical Methods ◽

Extractive Industries ◽

Lateral Variation ◽

Geophysical Investigation ◽

Great Cost ◽

Wide Range ◽

Field Practice ◽

Engineering Problems ◽

Professional Field

AbstractThere is a considerable Variation in the lithology and thickness of glacial and fluvial Sediments in Western Europe. This wide range of materials is associated with significant engineering problems and considerable economic interest from the extractive industries.Geophysical techniques are widely applied to map and investigate areas with glacial deposits and fluvio-glacial sands and gravels. There are sheet-like outwash deposits, some with buried and therefore unpredictable Channels, and smaller fissure and pocket deposits in rock. An assessment of the geometry of a deposit can be accurately achieved with geophysical methods, and electrical techniques have been particularly successful. The nature of the deposit, layering within the deposit, lateral Variation of lithology, thickness and depth to bedrock may all be established quickly and with great cost effectiveness.Numerous other problems occur with Quaternary environments particularly alteration and contamination of rock masses. Electrical techniques are also a powerful investigative tool in these situations.The success of these techniques depends upon the geophysical properties of the material to be investigated and the geophysical properties of the underlying sediment or bedrock, the technique actually selected, professional field practice and interpretation. These factors will be discussed and illustrated with reference to a number of case studies.

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Commission 47: Cosmology (Cosmologie)

Transactions of the International Astronomical Union ◽

10.1017/s0251107x00007483 ◽

1988 ◽

Vol 20 (1) ◽

pp. 653-655

Author(s):

G. Setti ◽

K. Satco ◽

J. Audouze ◽

G. de Vaucouleurs ◽

J. E. Gunn ◽

...

Keyword(s):

Large Scale ◽

Research Work ◽

Large Scale Structure ◽

Scale Structure ◽

Radio Sources ◽

Clusters Of Galaxies ◽

Extragalactic Radio Sources ◽

Vast Amount ◽

Wide Range ◽

Commission Report

The number of pages allocated to the commission report has been very limited and certainly not sufficient to cover in any exhaustive manner the wide range of topics relevant to cosmology and to provide also extensive bibliographies. Because of the vast amount of material to be covered, the report is based on a number of contributions from different colleagues who have been asked to highlight the main trends in the triennium (mid 1984 - mid 1987), together with a list of references sufficiently comprehensive to serve as a guideline for further reading. Unfortunately, two of the expected contributions did not reach me in time for inclusion in the report, and consequently topics such as the large scale structure and streaming motions, the clusters of galaxies and the counts of extragalactic radio sources are not included. However, it is my understanding that a large portion, if not all, of these topics will be covered in the reports of Commissions 28 and 40, and if true, this will at least avoid unnecessary overlaps. It should also be mentioned here that several proceedings of very recent IAU conferences provide excellent, updated and exhaustive reviews of the research work relevant to cosmology.

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Spectral Properties of Parkes Flat-Spectrum Radio Sources

International Astronomical Union Colloquium ◽

10.1017/s0252921100040689 ◽

1997 ◽

Vol 159 ◽

pp. 437-438

Author(s):

Michael J. Drinkwater ◽

Paul J. Francis ◽

Rachel L. Webster

Keyword(s):

Optical Properties ◽

Spectral Properties ◽

Radio Sources ◽

Large Sample ◽

Composite Spectra ◽

Spectrum Radio ◽

Wide Range

AbstractWe have constructed composite spectra of a large sample of flat-spectrum radio sources. The spectra are all very similar over a wide range of radio and optical properties, and are also similar to a composite of optically selected QSOs. We find, however, that the forbidden lines of the very reddest objects are anomalously strong.

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The VLB Array+

Symposium - International Astronomical Union ◽

10.1017/s0074180900078529 ◽

1984 ◽

Vol 110 ◽

pp. 377-382

Author(s):

K. I. Kellermann

Keyword(s):

Radio Telescope ◽

Spectral Resolution ◽

Radio Sources ◽

Extragalactic Radio Sources ◽

Wide Range

The VLB Array (VLBA) is a synthesis radio telescope which has been designed to extend the resolution of the VLA in order to allow sub-milliarcsec studies of compact galactic and extragalactic radio sources over a wide range of wavelengths and spectral resolution.

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A Population Study of Faint Compact Steep Spectrum Radio Sources: Self-Similar Growth

Publications of the Astronomical Society of Australia ◽

10.1071/as03004 ◽

2003 ◽

Vol 20 (1) ◽

pp. 75-78 ◽

Cited By ~ 4

Author(s):

Wolfgang Tschager ◽

Richard Schilizzi ◽

Huub Röttgering ◽

Ignas Snellen ◽

George Miley ◽

...

Keyword(s):

Population Study ◽

Growth Process ◽

Radio Galaxies ◽

Radio Sources ◽

Self Similarity ◽

Spectrum Radio ◽

Wide Range ◽

Self Similar ◽

Similar Growth ◽

Intrinsic Characteristic

AbstractThe main topic of this contribution is the investigation of the morphological self-similarity of the growth process during the gigahertz peaked spectrum (GPS) and compact steep spectrum (CSS) phase of evolving radio galaxies. By investigating a new sample of faint CSS radio sources we establish that self-similar evolution must hold for peaked spectrum sources over a wide range of luminosities as well as physical sizes. Thus, we argue that self-similarity should be regarded as an essential, intrinsic characteristic of the growth process of young radio sources, and be treated as such, and not merely as a supplementary constraint for evolution models.

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Third-Generation Calibrations for MeerKAT Observation

Galaxies ◽

10.3390/galaxies9040090 ◽

2021 ◽

Vol 9 (4) ◽

pp. 90

Author(s):

Viral Parekh ◽

Robert Kincaid ◽

Benjamin Hugo ◽

Athanaseus Ramaila ◽

Nadeem Oozeer

Keyword(s):

Large Scale ◽

Dynamic Range ◽

Cosmic Ray ◽

Point Sources ◽

Formation Mechanisms ◽

Radio Sources ◽

Wide Field ◽

Third Generation ◽

Radio Observations ◽

Wide Range

Superclusters and galaxy clusters offer a wide range of astrophysical science topics with regards to studying the evolution and distribution of galaxies, intra-cluster magnetization mediums, cosmic ray accelerations and large scale diffuse radio sources all in one observation. Recent developments in new radio telescopes and advanced calibration software have completely changed data quality that was never possible with old generation telescopes. Hence, radio observations of superclusters are a very promising avenue to gather rich information of a large-scale structure (LSS) and their formation mechanisms. These newer wide-band and wide field-of-view (FOV) observations require state-of-the-art data analysis procedures, including calibration and imaging, in order to provide deep and high dynamic range (DR) images with which to study the diffuse and faint radio emissions in supercluster environments. Sometimes, strong point sources hamper the radio observations and limit the achievement of a high DR. In this paper, we have shown the DR improvements around strong radio sources in the MeerKAT observation of the Saraswati supercluster by applying newer third-generation calibration (3GC) techniques using CubiCal and killMS software. We have also calculated the statistical parameters to quantify the improvements around strong radio sources. This analysis advocates for the use of new calibration techniques to maximize the scientific returns from new-generation telescopes.

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