527 research outputs found
Behavior of a sandy clay under vertical impact of geometric shapes
Sandy clay response under vertical impact of cone, plate, and plane geometric shape
Non-line-of-sight Node Localization based on Semi-Definite Programming in Wireless Sensor Networks
An unknown-position sensor can be localized if there are three or more
anchors making time-of-arrival (TOA) measurements of a signal from it. However,
the location errors can be very large due to the fact that some of the
measurements are from non-line-of-sight (NLOS) paths. In this paper, we propose
a semi-definite programming (SDP) based node localization algorithm in NLOS
environment for ultra-wideband (UWB) wireless sensor networks. The positions of
sensors can be estimated using the distance estimates from location-aware
anchors as well as other sensors. However, in the absence of LOS paths, e.g.,
in indoor networks, the NLOS range estimates can be significantly biased. As a
result, the NLOS error can remarkably decrease the location accuracy.
And it is not easy to efficiently distinguish LOS from NLOS measurements. In
this paper, an algorithm is proposed that achieves high location accuracy
without the need of identifying NLOS and LOS measurement.Comment: submitted to IEEE ICC'1
Demand-side energy storage system management in smart grid
An economical way to manage demand-side energy storage systems in the smart grid is proposed by using an H∞ design. The proposed design can adjust the stored energy state economically according to the price signal, while tolerating a certain degree of system uncertainty and having physical constraints on the stored energy level satisfied. Roughly speaking, batteries in the proposed design are charged during a low-price period while being discharged during a high-price period for cost control. Simulations show that the proposed energy storage system can meet the real-time power demand and save money in the long term in contrast to energy storage systems using constant-state schemes
Modified Partition Functions, Consistent Anomalies and Consistent Schwinger Terms
A gauge invariant partition function is defined for gauge theories which
leads to the standard quantization. It is shown that the descent equations and
consequently the consistent anomalies and Schwinger terms can be extracted from
this modified partition function naturally.Comment: 25 page
Prioritizing consumers in smart grid: A game theoretic approach
This paper proposes an energy management technique for a consumer-to-grid system in smart grid. The benefit to consumers is made the primary concern to encourage consumers to participate voluntarily in energy trading with the central power station (CPS) in situations of energy deficiency. A novel system model motivating energy trading under the goal of social optimality is proposed. A single-leader multiple-follower Stackelberg game is then studied to model the interactions between the CPS and a number of energy consumers (ECs), and to find optimal distributed solutions for the optimization problem based on the system model. The CPS is considered as a leader seeking to minimize its total cost of buying energy from the ECs, and the ECs are the followers who decide on how much energy they will sell to the CPS for maximizing their utilities. It is shown that the game, which can be implemented distributedly, possesses a socially optimal solution, in which the sum of the benefits to all consumers is maximized, as the total cost to the CPS is minimized. Numerical analysis confirms the effectiveness of the game. © 2010-2012 IEEE
Max-min Rate Optimization of Low-Complexity Hybrid Multi-User Beamforming Maintaining Rate-Fairness
A wireless network serving multiple users in the millimeter-wave or the
sub-terahertz band by a base station is considered. High-throughput multi-user
hybrid-transmit beamforming is conceived by maximizing the minimum rate of the
users. For the sake of energy-efficient signal transmission, the
array-of-subarrays structure is used for analog beamforming relying on
low-resolution phase shifters. We develop a convexsolver based algorithm, which
iteratively invokes a convex problem of the same beamformer size for its
solution. We then introduce the soft max-min rate objective function and
develop a scalable algorithm for its optimization. Our simulation results
demonstrate the striking fact that soft max-min rate optimization not only
approaches the minimum user rate obtained by max-min rate optimization but it
also achieves a sum rate similar to that of sum-rate maximization. Thus, the
soft max-min rate optimization based beamforming design conceived offers a new
technique of simultaneously achieving a high individual quality-of-service for
all users and a high total network throughput
Non-locality and Medium Effects in the Exclusive Photoproduction of Eta Mesons on Nuclei
A relativistic model for the quasifree exclusive photoproduction of
mesons on nuclei is extended to include both non-local and medium effects. The
reaction is assumed to proceed via the dominant contribution of the
S(1535) resonance. The complicated integrals resulting from the
non-locality are simplified using a modified version of a method given by
Cooper and Maxwell. The non-locality effects are found to affect the magnitude
of the cross section. Some possibilities reflecting the effects of the medium
on the propagation and properties of the intermediate S resonance are
studied. The effects of allowing the S to interact with the medium via
mean field scalar and vector potentials are considered. Both broadening of
width and reduction in mass of the resonance lead to a suppression of the
calculated cross sections.Comment: 19 pages, 7 figure
The Interplay Between and T
We extend a recent computation of the dependence of the free energy, F, on
the noncommutative scale to theories with very different UV
sensitivity. The temperature dependence of strongly suggests that a reduced
number of degrees of freedom contributes to the free energy in the non-planar
sector, , at high temperature. This phenomenon seems generic,
independent of the UV sensitivity, and can be traced to modes whose thermal
wavelengths become smaller than the noncommutativity scale. The temperature
dependence of can then be calculated at high temperature using
classical statistical mechanics, without encountering a UV catastrophe even in
large number of dimensions. This result is a telltale sign of the low number of
degrees of freedom contributing to in the non-planar sector at high
temperature. Such behavior is in marked contrast to what would happen in a
field theory with a random set of higher derivative interactions.Comment: 14 pages, 1 eps figur
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