Insect-inspired sensor fusion algorithms have presented a promising avenue in the development of robust and efficient systems, owing to the insects' ability to process numerous streams of noisy ...sensory data. The ring attractor neural network architecture has been identified as a noteworthy model for the optimal integration of diverse insect sensors. Expanding on this, our research presents an innovative bio-inspired ring attractor neural network architecture designed to augment the performance of microsatellite attitude determination systems through the fusion of data from multiple gyroscopic sensors.Extensive simulations using a nonlinear model of the microsatellite, while incorporating specific navigational disturbances, have been conducted to ascertain the viability and effectiveness of this approach. The results obtained have been superior to those of alternative methodologies, thus highlighting the potential of our proposed bio-inspired fusion technique. The findings indicate that this approach could significantly improve the accuracy and robustness of microsatellite systems across a wide range of applications.
The properties that quantify photonic topological insulators (PTIs), Berry phase, Berry connection, and Chern number, are typically obtained by making analogies between classical Maxwell's equations ...and the quantum mechanical Schrödinger equation, writing both in Hamiltonian form. However, the aforementioned quantities are not necessarily quantum in nature, and for photonic systems they can be explained using only classical concepts. Here, we provide a derivation and description of PTI quantities using classical Maxwell's equations, demonstrate how an electromagnetic mode can acquire Berry phase, and discuss the ramifications of this effect. We consider several examples, including wave propagation in a biased plasma, and radiation by a rotating isotropic emitter. These concepts are discussed without invoking quantum mechanics and can be easily understood from an engineering electromagnetics perspective.
We consider the asymptotic behavior of the polarization process in the large block-length regime when transmission takes place over a binary-input memoryless symmetric channel W . In particular, we ...study the asymptotics of the cumulative distribution P( Zn ≤ z ), where { Zn } is the Bhattacharyya process associated with W , and its dependence on the rate of transmission. On the basis of this result, we characterize the asymptotic behavior, as well as its dependence on the rate, of the block error probability of polar codes using the successive cancellation decoder. This refines the original asymptotic bounds by Arıkan and Telatar. Our results apply to general polar codes based on l × l kernel matrices. We also provide asymptotic lower bounds on the block error probability of polar codes using the maximum a posteriori (MAP) decoder. The MAP lower bound and the successive cancellation upper bound coincide when l = 2, but there is a gap for l > 2.
•Collector efficiency is found to be 71.84% higher with SWCNT nanofluid than water.•Thermal performance of an ETSC is studied with varying mass flow rates.•Collector efficiency is investigated with ...3vol.% of SWCNT nanofluids.•Maximum collector efficiency is found 93.43% with SWCNT (0.2vol.%) nanofluid.•An empirical correlation of thermal efficiency is developed.
An experimental study was performed to determine the thermal efficiency of an Evacuated Tube Solar Collector (ETSC) using water based Single Walled Carbon Nanotubes (SWCNTs) nanofluids. Experiments were carried out using SWCNTs nanofluids having volume concentrations of 0.05, 0.1, and 0.2vol.%. The performance of the collector was compared with SWCNTs nanofluid and water using the flow rates of 0.008, 0.017, and 0.025kg/s. The experiments were undertaken according to ASHRAE standard 93-2003. The results show that, the collector efficiency improved with SWCNTs nanofluids compared to water as a working fluid. The maximum efficiency found to be 93.43% for 0.2vol.% SWCNTs nanofluids at a mass flow rate of 0.025kg/s. The collector efficiency shows greater enhancement with the increasing volume fractions of SWCNT nanoparticles and flow rate. In conclusions, results suggest that SWCNTs nanofluids can be used as the working fluids in an ETSC to absorb heat from solar radiation and to convert solar energy into thermal energy efficiently.
We show that the energy-transport efficiency in a chain of two-level emitters can be drastically enhanced by the presence of a photonic topological insulator (PTI). This is obtained by exploiting the ...peculiar properties of its nonreciprocal surface plasmon polariton (SPP), which is unidirectional, and immune to backscattering, and propagates in the bulk band gap. This amplification of transport efficiency can be as much as 2 orders of magnitude with respect to reciprocal SPPs. Moreover, we demonstrate that despite the presence of considerable imperfections at the interface of the PTI, the efficiency of the SPP-assisted energy transport is almost unaffected by discontinuities. We also show that the SPP properties allow energy transport over considerably much larger distances than in the reciprocal case, and we point out a particularly simple way to tune the transport. Finally, we analyze the specific case of a two-emitter chain and unveil the origin of the efficiency amplification. The efficiency amplification and the practical advantages highlighted in this work might be particularly useful in the development of new devices intended to manage energy at the atomic scale.
Motivated by the significant performance gains which polar codes experience under successive cancellation list decoding, their scaling exponent is studied as a function of the list size. In ...particular, the error probability is fixed, and the tradeoff between the block length and back-off from capacity is analyzed. A lower bound is provided on the error probability under MAP decoding with list size L for any binary-input memoryless output-symmetric channel and for any class of linear codes such that their minimum distance is unbounded as the block length grows large. Then, it is shown that under MAP decoding, although the introduction of a list can significantly improve the involved constants, the scaling exponent itself, i.e., the speed at which capacity is approached, stays unaffected for any finite list size. In particular, this result applies to polar codes, since their minimum distance tends to infinity as the block length increases. A similar result is proved for genie-aided successive cancellation decoding when transmission takes place over the binary erasure channel, namely, the scaling exponent remains constant for any fixed number of helps from the genie. Note that since genie-aided successive cancellation decoding might be strictly worse than successive cancellation list decoding, the problem of establishing the scaling exponent of the latter remains open.
Under certain running conditions, the CERN Large Hadron Collider (LHC) can be considered as a photon–photon collider. Indeed, in proton–proton, proton–ion, ion–ion collisions, when incoming particles ...pass very close to each other in very peripheral collisions, the incoming protons or ions remain almost intact and continue their path along the beam axis. Then, only the electromagnetic (EM) fields of these ultra-relativistic charged particles (protons or ions) interact to leave a signature in the central detectors of the LHC experiments. The interest is that the photon–photon interactions happen at unprecedented energies (a few TeV per nucleon pairs) where the quantum electrodynamics (QED) theory can be tested in extreme conditions and unforeseen laws of nature could be discovered. In this report, we propose a focus on a particular reaction, called light-by-light scattering in which two incoming photons interact, producing another pair of photons. We describe how experimental results have been obtained at the LHC. In addition, we discuss prospects for on-shell photon–photon interactions in dedicated laser beam facilities. Potential signatures of new physics might manifest as resonant deviations in the refractive index, induced by anomalous light-by-light scattering effects. Importantly, we explain how this process can be used to probe the physics beyond the standard model such as theories that include large extra dimensions. Finally, some perspectives and ideas are given for future data taking or experiments.
Entanglement between two qubits (two level atoms) mediated by surface plasmons in three-dimensional plasmonic waveguides is studied using a quantum master equation formalism. Two types of waveguides, ...a nanowire and a V-shaped channel cut in a flat metal plane, are considered. The Green functions for the waveguides, which rigorously describes the dissipative qubit environment, are calculated numerically using a direct finite-difference time-domain (FDTD) solution of Maxwell's equations. Finite-length effects are shown to play a crucial role in enhancing entanglement, and resonant-length plasmonic waveguides can provide higher entanglement between qubits than infinite-length waveguides. It is also shown that coupling slots can improve entanglement via stronger qubit-waveguide coupling, for both the infinite- and finite-waveguide cases. The formalism used in the paper can be applied to a wide range of plasmonic waveguides.
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