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Wyszukujesz frazę "black hole" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Improved MCBDS for defending against gray hole and black hole attacks in MANETs
Autorzy:
Haghighi, A.
Mizanian, K.
Mirjalily, G.
Powiązania:
https://bibliotekanauki.pl/articles/102490.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
mobile ad hoc network
cooperative bait detection scheme (CBDS)
modified CBDS (MCBDS)
black hole
gray hole
MANET
Opis:
Mobile Ad-hoc Networks (MANETs) are widely used nowadays. Because of their characteristics as open media, dynamic topology, being infrastructure-less and lack of centralized monitoring, MANET is vulnerable to a wide range of attacks like blackhole and grayhole. Blackhole and grayhole attacks refer to the attacks that breach the security by performing packet forwarding and routing misbehavior and cause denial of service in MANETs. In this paper we improved our previous work on MCBDS, we reduced false-positive rate more than before and on average it dropped to zero. The proposed method employs Network Simulator-2 (NS-2) to validate the effectiveness under different scenarios. Simulation results show that improved MCBDS has same performance as CBDS in terms of throughput and end-to-end delay and as much as the presence of malicious nodes increased, improved MCBDS performs better than CBDS.
Źródło:
Advances in Science and Technology. Research Journal; 2016, 10, 30; 1-8
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Is there a limit of matter divisibility?
Autorzy:
Jacyna-Onyszkiewicz, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/703143.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
black hole
entropy
holographic principle
Opis:
Investigation of the thermal properties of the black holes by the quantum statistical mechanics has implied that matter cannot be divided to infinity because the number of independent parameters completely describing a subject of a limited volume is finite.
Źródło:
Nauka; 2007, 3
1231-8515
Pojawia się w:
Nauka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation, propagation and detection of gravitational waves
Autorzy:
Shaliq, Mohamed Armoon
Prasanna, R. Sharath
Powiązania:
https://bibliotekanauki.pl/articles/1819192.pdf
Data publikacji:
2020
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
LIGO
virgo
gravitational waves
interferometer
black hole collision
neutron star collision
interferometr LIGO
fala grawitacyjna
interferometr
czarna dziura
gwiazdy neutronowe
Opis:
Gravitational Waves are a new form of energy that is too sensitive to measure. The study of Gravitational Waves paves a unique way to approach the new era of universal science. It is quite interesting to note that experimental proof of the early theory of Einstein is successfully proven after many years. The manuscript depicts the concepts of Gravitational Waves, propagation of Gravitational Waves, its effect on objects on Earth and various factors that affect the measurements along with their method of approach to detect Gravitational Waves. Detecting Gravitational Waves is a tedious process and it requires a very highly sensitive experimental setup to carry out the detection as well as on considering the current trend of technology it is observed that detection faces massive limitations. Detection of Gravitational Waves opens up a new way for understanding supermassive binary systems such as neutron stars and black holes and also for studying on Early universe history.
Źródło:
Journal of Mechanical and Energy Engineering; 2020, 4, 2; 189--196
2544-0780
2544-1671
Pojawia się w:
Journal of Mechanical and Energy Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study of Quantum Effects in General Relativity
Autorzy:
Sooriyaarachchi, V. K. C.
Wijewardena Gamalath, K. A. I. L.
Powiązania:
https://bibliotekanauki.pl/articles/1058092.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Hawking effect
Rindler observer
Schwarzschild black hole
Unruh effects
event horizon
information loss paradox
scalar curvature
surface gravity
transplanckian problem
Opis:
The present work discusses the conceptual and technical issues encountered in formulating a quantized theory of gravity, via the reconciliation of quantum mechanics and general relativity. Quantum effects arising in a classically defined space-time derived through a semi classical approximation are studied at length and the significance of the particle interpretation in quantum field theory in the origin of such effects is established. The contradicting nature of the quantum effects against classically established principles is studied by considering the Hawking effect in a Schwarzschild black hole space-time. Further, the limits of prominent manifestation of the quantum effects with regards to the black hole mass is calculated taking into consideration the cosmic microwave background and the lifetime of the universe. Quantum effects are established as essential in incorporating thermal physics and black hole mechanics in a consistent formulation. Finally, the validity of the semi classical approximation is studied in terms of Planck scale black holes, transplanckian problem and the information loss paradox and the requirement for a fully quantized theory of gravity is realized.
Źródło:
World Scientific News; 2019, 134, 2; 198-219
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Time at the Level of a High Speed Moving Object
Autorzy:
Spacey, John
Powiązania:
https://bibliotekanauki.pl/articles/1193284.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
General Relativity
Quantum Mechanics
astronomy
astrophysics
black-hole
cosmology
dark Matter and dark Energy
galaxies
gravity
negative space-time
Opis:
I think that far-away travels into Space are possible in the way that it is possible to find again people on our Earth, after the return of a very long travel into Space, not aged, like the people who have traveled inside the spacecraft. Current physics does not allow this and I have developed the following Theory which would thus complement the current Theory of General Relativity when we go to the limits of the reasoning. Current Theories like General Relativity or Quantum Mechanics are not impacted when the reasoning is not pushed to the limits. My reasoning at the limits just complements current Theories when the parameters take extreme values and thus the logic of current physics is respected.
Źródło:
World Scientific News; 2021, 153, 1; 1-42
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of Rotating Black Holes
Autorzy:
Vindana, W. M. H. P.
Wijewardena Gamalath, K. A. I. L.
Powiązania:
https://bibliotekanauki.pl/articles/1158501.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Hawking radiation
Hawking temperature
Kerr black hole
Kerr-Newman black hole
entropy
mass variation
rotating black holes
thermodynamic parameters
Opis:
Considering the analogy between classical thermodynamic parameters and black hole parameters, the four laws of thermodynamics are reinterpreted for Kerr and Kerr-Newman black holes. A simple model for the dynamic relationships was obtained by considering the surface area of the outer horizon of a Kerr and Kerr-Neumann black hole as the area of a perfect black body. Finding the conditions these black holes should satisfy, the equations were numerically solved and simulated for the Hawking temperature, Hawking radiation and entropy variations of Kerr and Kerr-Newman black holes. The Hawking temperature and Hawking radiation of a given rotating black hole drastically increases at the final stage of the black hole evaporation. In the meantime, the entropy of a rotating black hole drastically decreases through the time. The additional angular momentum and the charge effects gain high Hawking temperatures and high Hawking radiation values for the black holes while these effects reduce the entropy of the black holes.
Źródło:
World Scientific News; 2018, 114; 106-125
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Mathematical Analysis of Black-Hole Information Loss Paradox
Autorzy:
Vishal, V.
Siddharth, B.
Venkatachalam, C.
Powiązania:
https://bibliotekanauki.pl/articles/411529.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
black hole
Information paradox
AdS/CFT correspondence
quantum field theory
Opis:
A black-hole is an astronomical entity which possesses infinite density at its gravitational singularity or singular point. The capacity of a black-hole to completely rip-off an entire solar system without leaving any evidence is to be noted. A debate has been going on over the past few decades regarding the information storage in black-holes. The discovery of Hawking radiation, which predicts complete evaporation of mass violates unitarity ie. Conservation of probability and energy fails. Recent discoveries suggest that regular remnant of black-hole survives evaporation , as a result information of the object devoured can be contained. These remnants are grouped into embedded sub-manifolds. These manifolds are the result of a five-dimensional constant curvature bulk in space-time. Five-dimensional gravity can be recovered from brane-world resulting from equations of bulk geometry. Gravity can be explained by space-time theory and also quantum theory in the form of Gravitons. On observing the manifold, the gravitons show deformations in dimensions, rather than being constant. The perturbations in geometry can be related to embedding functions which should remain differentiable and regular. Regularity is related to the inverse functions theorem. Manifold observations followed by a mathematical approach can possibly retain information about objects devoured by the black-hole.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 13; 8-12
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of Primary Spectra of Particle Radiation from Black Holes
Autorzy:
Wijewardhana, C. N. T.
Wijewardena Gamalath, K. A. I. L.
Powiązania:
https://bibliotekanauki.pl/articles/1193473.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Hawking radiation
Higgs boson emission
Kerr black hole
Planck mass
Primary emission spectra
Schwarzschild black hole

Z0
primordial black hole
quark and gluon emission
Opis:
The instantaneous primary emission spectra of particles radiating from Schwarzschild black holes and maximally rotating Kerr black holes of masses 1013 – 1015 g were investigated and C code, BlackHawk was used for the simulations. From a Schwarzschild black hole of mass 3.53×1013 g, gluons had the lowest cutoff energy, 199 MeV. The emission spectra were dominated by coloured particles, quarks having with the highest overall emission rate, 2.826×1022 GeV-1s-1 at energy 1.205 GeV. The leptons e±, μ±, τ± showed similar variation in emission rates. The only particles emitted with energies below the rest mass of u quarks were neutrinos, photons, and e±. At greater particle energies (> ~ 2 GeV) the emission rates of all particles were almost equivalent. The emission of vector bosons, Z0 and W± were negligible and became significant when the mass reduced to ~1011 g and then gluons, W±, Z0 and photons were emitted similar to each other with a peak at energy, 280 GeV. The emitting rates of gluons, quarks, neutrinos, W±, e±, μ±, τ±, Z0, photons, and Higgs bosons are in decreasing order respectively. As the mass of the black hole is reduced to 1.06×108 g, quarks were emitted at the highest rate 2.826×1022 GeV-1s-1 at 4010 GeV peak energy and at energies between rest mass energy of Higgs boson and 1.25×105 GeV, the emission of Higgs bosons exceeded the emission of quarks. For maximally rotating Kerr black hole of mass 3.53×1013 g, W±, Z0 and Higgs boson were emitted at higher emission rates 1012 – 1015 GeV-1s-1 and for mass 1.06×108 g, the gluons had the highest overall emission rate at the peak energy. At extremely high energies, the gluon emission rates are less than the emission rates of Higgs bosons, quarks, neutrinos, and e±, μ±, τ±. The spin-dependent behaviour of spectra is also present.
Źródło:
World Scientific News; 2021, 158; 105-129
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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