2,157 research outputs found
Scheduling for Multi-Camera Surveillance in LTE Networks
Wireless surveillance in cellular networks has become increasingly important,
while commercial LTE surveillance cameras are also available nowadays.
Nevertheless, most scheduling algorithms in the literature are throughput,
fairness, or profit-based approaches, which are not suitable for wireless
surveillance. In this paper, therefore, we explore the resource allocation
problem for a multi-camera surveillance system in 3GPP Long Term Evolution
(LTE) uplink (UL) networks. We minimize the number of allocated resource blocks
(RBs) while guaranteeing the coverage requirement for surveillance systems in
LTE UL networks. Specifically, we formulate the Camera Set Resource Allocation
Problem (CSRAP) and prove that the problem is NP-Hard. We then propose an
Integer Linear Programming formulation for general cases to find the optimal
solution. Moreover, we present a baseline algorithm and devise an approximation
algorithm to solve the problem. Simulation results based on a real surveillance
map and synthetic datasets manifest that the number of allocated RBs can be
effectively reduced compared to the existing approach for LTE networks.Comment: 9 pages, 10 figure
Bis(μ-naphthalene-1,8-dicarboxylÂato)bisÂ[aquaÂ(2,2′-bipyridine)zinc(II)] tetraÂhydrate
The title complex, [Zn2(C12H6O4)2(C10H8N2)2(H2O)2]·4H2O, is a binuclear complex with two independent ZnII ions in a slightly disorted trigonal bipyramidal environment, coordinated by one aqua ligand, two naphthalene-1,8-dicarboxylÂate ligands and one 2,2′-bipyridine ligand. π–π InterÂactions [centroid–centroid distance of 3.8489 (5) Å] and O—H⋯O hydrogen bonds connect the molÂecules, forming a three-dimensional structure
Observation of backscattering-immune chiral electromagnetic modes without time reversal breaking
A strategy is proposed to realize robust transport in time reversal invariant
photonic system. Using numerical simulation and microwave experiment, we
demonstrate that a chiral guided mode in the channel of a three-dimensional
dielectric woodpile photonic crystal is immune to the scattering of a square
patch of metal or dielectric inserted to block the channel. The chirality based
robust transport can be realized in nonmagnetic dielectric materials without
any external field.Comment: 16 pages, 5 figure
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