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Efficient framedslotted Aloha algorithm with pilot frame and binary selection for anticollision of RFID tags
 IEEE Commun. Letters
, 2008
"... Abstract—Reducing the number of tag collisions is one of the most important issues in RFID systems, as collisions induce inefficiency. This paper presents a mechanism of grouping of tags via a bit mask, quick tag estimation by a pilot frame and near optimal binary treebased collision resolution wit ..."
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Cited by 6 (2 self)
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Abstract—Reducing the number of tag collisions is one of the most important issues in RFID systems, as collisions induce inefficiency. This paper presents a mechanism of grouping of tags via a bit mask, quick tag estimation by a pilot frame and near optimal binary treebased collision resolution with a frame. Performance analysis and simulation results show that the proposed anticollision algorithm consumes fewer time slots as compared to previous work, and approaches to the case with the optimal frame size using binary tree collision resolution. Index Terms—Anticollision, collision threshold, pilot frame, RFID, tag estimation, tag identification. I.
First EuroNGI Workshop: New Trends in Modelling, Quantitative Methods and Measurements Two queueing models for cable access networks
"... In this paper we will discuss two queueing models with a twodimensional state space. The first model is an¡£¢¤¡¥¢§ ¦ queueing model with gated random order of service. In this service discipline customers are first gathered in an unordered waiting room before they are put in random order in an orde ..."
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In this paper we will discuss two queueing models with a twodimensional state space. The first model is an¡£¢¤¡¥¢§ ¦ queueing model with gated random order of service. In this service discipline customers are first gathered in an unordered waiting room before they are put in random order in an ordered service queue at the moment that this latter
Interpolation and approximation of polynomials in finite fields over a short interval from noisy values,” arXiv.org preprint archive
"... Abstract. Motivated by a recently introduced HIMMO key distribution scheme, we consider a modification of the noisy polynomial interpolation problem of recovering an unknown polynomial f(X) ∈ Z[X] from approximate values of the residues of f(t) modulo a prime p at polynomially many points t take ..."
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Cited by 4 (3 self)
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Abstract. Motivated by a recently introduced HIMMO key distribution scheme, we consider a modification of the noisy polynomial interpolation problem of recovering an unknown polynomial f(X) ∈ Z[X] from approximate values of the residues of f(t) modulo a prime p at polynomially many points t taken from a short interval. 1.
Uniform Illumination Rendering Using an Array of LEDs: A Signal Processing Perspective
"... Abstract—An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basi ..."
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Cited by 4 (0 self)
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Abstract—An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic illumination pattern, i.e., the light pattern of a single LED, and the setting of LED illumination levels, respectively. Thereafter, we propose to use the relative mean squared error as the cost function to measure the uniformity of the realized illumination pattern, and provide an analysis for this cost function. Based on the analysis, the design of a basic illumination pattern is discussed. The performances of a few basic illumination patterns are compared, and an approach for optimizing the basic illumination pattern through a weighted combination of these basic patterns is also proposed. A weighted combination of Gaussian and raisedcosine functions is found to yield the best results. Finally, three basic regular grid shapes for an LED array are compared. The results show that 13 % and 39 % of LEDs can be saved for the same degree of uniformity, using the hexagonal instead of the rectangular and triangular grid, respectively. Index Terms—Basic illumination pattern, LED illumination, regular grid, twodimensional signal processing.
November 1992 LTH 291 heplat/9211018 Gribov Copies And Other Gauge Fixing Beasties On The Lattice
, 1992
"... We study the nature of gauge fixing ambiguities in two dimensional gauge theories. We find that these ambiguities can be related to the asociated spin model. They can be eliminated by means of a (multigrid) annealing algorithm. Gauge fixing is by now a useful tool in lattice gauge calculations. Smoo ..."
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We study the nature of gauge fixing ambiguities in two dimensional gauge theories. We find that these ambiguities can be related to the asociated spin model. They can be eliminated by means of a (multigrid) annealing algorithm. Gauge fixing is by now a useful tool in lattice gauge calculations. Smooth gauges, like the Coulomb gauge and the Landau gauge, are commonly used in propagator calculations [ 1], as well as in wavefunction calculations [ 2]. In monopole studies, the socalled maximally Abelian gauge is frequently employed [ 3]. However, since the work of Gribov [ 4], it is known that ‘fixing the gauge is not quite fixing the gauge’. In other words, it is possible to locally fix the gauge, but it need not always be possible to globally fix the gauge. Since one uses a slightly stronger condition on the lattice than in the continuum, it was long hoped that the Gribov ambiguity was absent on the lattice. A few years ago, it was shown that these hopes were idle [ 5]. In order to get a better understanding of the nature of the Gribov ambiguity on the lattice, we shall study the occurrence of copies in 2d U(1) and 2d SU(2) when fixing to the Landau gauge. The continuum version of the Landau gauge condition, ∂µA g µ = 0, A g µ = g † (∂µ + Aµ)g, translates to the lattice as Im ∑ [U g † µ(x) − Ug µ (x − ˆµ)] traceless = 0, (1) µ U g µ (x) = g † (x)Uµ(x)g(x + ˆµ). As was mentioned above, usually a slightly stronger condition is used, namely minimizing a functional F, where F is given by F(g, U) = 1 dV N Re Tr[1 − U g µ(x)], (2) x,µ for SU(N) in d dimensions on a lattice containing V lattice sites. It is easy to see that if (2) is
DIGITAL COMPENSATION OF RECEIVER CLIPPING FOR DVB RECEPTION ON LOWPOWER MOBILE PHONES
"... Battery lifetime is a critical issue for digital television (DVB) viewing on mobile phones. The number of quantization steps used in the analogtodigital converter (ADC) is an important factor in the total power consumption of a DVB receiver. The OFDM signals require a large resolution of the ADC. ..."
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Battery lifetime is a critical issue for digital television (DVB) viewing on mobile phones. The number of quantization steps used in the analogtodigital converter (ADC) is an important factor in the total power consumption of a DVB receiver. The OFDM signals require a large resolution of the ADC. We propose a digital postprocessing method that allows reduction of the peaktoaverage margin by compensating for clipping artifacts when the ADC is saturated. Clipped OFDM peaks cause spurious signals on empty subcarriers, which can be used to recover the original signal and to eliminate clipping artifacts. 1.
A Solvable Model for Intersecting Loops
, 1992
"... We show that some models with nonlocal (and nonlocalizable) interactions have a property, called quasilocality, which allows for the definition of a transfer matrix. We give the YangBaxter equation as a sufficient condition for the existence of a family of commuting transfer matrices and solve t ..."
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We show that some models with nonlocal (and nonlocalizable) interactions have a property, called quasilocality, which allows for the definition of a transfer matrix. We give the YangBaxter equation as a sufficient condition for the existence of a family of commuting transfer matrices and solve them for a loop model with intersections. This solvable model is then analyzed in some detail and its applications to a Lorentz gas are briefly discussed. In the field of solvable models in statistical mechanics it is customary to restrict oneself to models with local interactions. This restriction makes it hard to treat models of extended objects, such as linear or branched polymers, directly. The usual approach is to consider the graphical expansion of a bonafide model with local interactions, such as the Potts model or an O(n) model, and derive properties of the graphical model from the local model. This is not always possible. In this paper we present a model, the intersecting loop model, for which there is no local representation as far as we know. We consider a dense gas of loops on a square lattice. In contrast to the loop gas that one obtains in the graphical expansion of the Potts model or a RSOS model, our loops are allowed to intersect themselves and each other. On every site of a square lattice we randomly put a mirror along one of the diagonals, or leave it empty. The mirrors deflect photons that run along the edges of the lattice. If we impose toroidal boundary conditions every photon follows a closed orbit. Obviously every edge belongs to precisely one path. In this paper we are mainly interested in the statistics of the paths, i.e. given the probabilities that a site is empty or that it carries a mirror oriented along the NESW or the NWSE diagonal we want to calculate quantities
A FIRST ANALYSIS OF MIMO COMMUNICATION AS A BASIS FOR LOW POWER WIRELESS
"... This paper presents a comparison between multipleinput multipleoutput (MIMO) systems and a singleinput singleoutput (SISO) system. For a fair comparison the total power dissipation of the radio frequency (RF) front end and the analogtodigital conversion is kept constant. As a benchmark the outa ..."
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This paper presents a comparison between multipleinput multipleoutput (MIMO) systems and a singleinput singleoutput (SISO) system. For a fair comparison the total power dissipation of the radio frequency (RF) front end and the analogtodigital conversion is kept constant. As a benchmark the outage capacity is used. Monte Carlo simulations show that a MIMO system consisting of lowpower lowresolution receivers achieves a higher datarate and better reliability than a SISO system. However, the scaling of the RF front end should remain within the constraints of the considered semiconductor process. To ensure a more realistic scenario, correlation between the transmit antennas and correlation between the receive antennas is assumed. 1.
1DTLSHIMMO: Efficiently Securing a PostQuantum World with a FullyCollusion Resistant KPS
"... The future development of quantumcomputers could turn many key agreement algorithms used in the Internet today fully insecure, endangering many applications such as online banking, ecommerce, ehealth, etc. At the same time, the Internet is further evolving to enable the Internet of Things (IoT) i ..."
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The future development of quantumcomputers could turn many key agreement algorithms used in the Internet today fully insecure, endangering many applications such as online banking, ecommerce, ehealth, etc. At the same time, the Internet is further evolving to enable the Internet of Things (IoT) in which billions of devices deployed in critical applications like healthcare, smart cities and smart energy are being connected to the Internet. The IoT not only requires strong and quantumsecure security, as current Internet applications, but also efficient operation. The recently introduced HIMMO scheme enables lightweight identitybased key sharing and verification of credentials in a noninteractive way. The collusion resistance properties of HIMMO enable direct secure communication between any pair of Internetconnected devices. The facts that attacking HIMMO requires lattice techniques and that it is extremely lightweight make HIMMO an ideal lightweight approach for key agreement and information verification in a postquantum world. Building on the HIMMO scheme, this paper firstly shows how HIMMO can be efficiently implemented even in resourceconstrained devices enabling combined key agreement and credential verification one order of magnitude more efficiently than using ECDHECDSA. while being quantum secure. We further explain how HIMMO helps to secure the Internet and IoT by introducing the DTLSHIMMO operation mode. DTLS, the datagram version of TLS, is becoming the standard security protocol in the IoT, however, it is very frequently discussed that it does not offer the right performance for IoT scenarios. Our design, implementation, and evaluation show that DTLSHIMMO operation mode achieves the security properties of DTLSCertificate security suite while being quantum secure and exhibiting the overhead of symmetrickey primitives. 1
unknown title
, 2008
"... Optimal codes for correcting a single (wraparound) burst of erasures ..."
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