1,041,934 research outputs found

    Exploring Alternatives to use Master/Slave Full Duplex Switched Ethernet for Avionics Embedded Applications

    Get PDF
    The complexity of distributed real-time systems, including military embedded applications, is increasing due to an increasing number of nodes, their functionality and higher amounts of exchanged data. This higher complexity imposes major development challenges when nonfunctional properties must be enforced. On the other hand, the current military communication networks are a generation old and are no longer effective in facing such increasingly complex requirements. A new communication network, based on Full Duplex Switched Ethernet and Master/slave approach, has been proposed previously. However, this initial approach is not efficient in terms of network bandwidth utilization. In this paper we propose two new alternative approaches that can use the network bandwidth more efficiently. In addition we provide a preliminary qualitative assessment of the three approaches concerning different factors such as performance, scalability, complexity and flexibility

    Quantum Communication Cannot Simulate a Public Coin

    Full text link
    We study the simultaneous message passing model of communication complexity. Building on the quantum fingerprinting protocol of Buhrman et al., Yao recently showed that a large class of efficient classical public-coin protocols can be turned into efficient quantum protocols without public coin. This raises the question whether this can be done always, i.e. whether quantum communication can always replace a public coin in the SMP model. We answer this question in the negative, exhibiting a communication problem where classical communication with public coin is exponentially more efficient than quantum communication. Together with a separation in the other direction due to Bar-Yossef et al., this shows that the quantum SMP model is incomparable with the classical public-coin SMP model. In addition we give a characterization of the power of quantum fingerprinting by means of a connection to geometrical tools from machine learning, a quadratic improvement of Yao's simulation, and a nearly tight analysis of the Hamming distance problem from Yao's paper.Comment: 12 pages LaTe

    A composition theorem for parity kill number

    Full text link
    In this work, we study the parity complexity measures Cmin[f]{\mathsf{C}^{\oplus}_{\min}}[f] and DT[f]{\mathsf{DT^{\oplus}}}[f]. Cmin[f]{\mathsf{C}^{\oplus}_{\min}}[f] is the \emph{parity kill number} of ff, the fewest number of parities on the input variables one has to fix in order to "kill" ff, i.e. to make it constant. DT[f]{\mathsf{DT^{\oplus}}}[f] is the depth of the shortest \emph{parity decision tree} which computes ff. These complexity measures have in recent years become increasingly important in the fields of communication complexity \cite{ZS09, MO09, ZS10, TWXZ13} and pseudorandomness \cite{BK12, Sha11, CT13}. Our main result is a composition theorem for Cmin{\mathsf{C}^{\oplus}_{\min}}. The kk-th power of ff, denoted fkf^{\circ k}, is the function which results from composing ff with itself kk times. We prove that if ff is not a parity function, then Cmin[fk]Ω(Cmin[f]k).{\mathsf{C}^{\oplus}_{\min}}[f^{\circ k}] \geq \Omega({\mathsf{C}_{\min}}[f]^{k}). In other words, the parity kill number of ff is essentially supermultiplicative in the \emph{normal} kill number of ff (also known as the minimum certificate complexity). As an application of our composition theorem, we show lower bounds on the parity complexity measures of Sortk\mathsf{Sort}^{\circ k} and HIk\mathsf{HI}^{\circ k}. Here Sort\mathsf{Sort} is the sort function due to Ambainis \cite{Amb06}, and HI\mathsf{HI} is Kushilevitz's hemi-icosahedron function \cite{NW95}. In doing so, we disprove a conjecture of Montanaro and Osborne \cite{MO09} which had applications to communication complexity and computational learning theory. In addition, we give new lower bounds for conjectures of \cite{MO09,ZS10} and \cite{TWXZ13}

    Efficient quantum protocols for XOR functions

    Full text link
    We show that for any Boolean function f on {0,1}^n, the bounded-error quantum communication complexity of XOR functions ff\circ \oplus satisfies that Qϵ(f)=O(2d(logf^1,ϵ+lognϵ)log(1/ϵ))Q_\epsilon(f\circ \oplus) = O(2^d (\log\|\hat f\|_{1,\epsilon} + \log \frac{n}{\epsilon}) \log(1/\epsilon)), where d is the F2-degree of f, and f^1,ϵ=ming:fgϵf^1\|\hat f\|_{1,\epsilon} = \min_{g:\|f-g\|_\infty \leq \epsilon} \|\hat f\|_1. This implies that the previous lower bound Qϵ(f)=Ω(logf^1,ϵ)Q_\epsilon(f\circ \oplus) = \Omega(\log\|\hat f\|_{1,\epsilon}) by Lee and Shraibman \cite{LS09} is tight for f with low F2-degree. The result also confirms the quantum version of the Log-rank Conjecture for low-degree XOR functions. In addition, we show that the exact quantum communication complexity satisfies QE(f)=O(2dlogf^0)Q_E(f) = O(2^d \log \|\hat f\|_0), where f^0\|\hat f\|_0 is the number of nonzero Fourier coefficients of f. This matches the previous lower bound QE(f(x,y))=Ω(logrank(Mf))Q_E(f(x,y)) = \Omega(\log rank(M_f)) by Buhrman and de Wolf \cite{BdW01} for low-degree XOR functions.Comment: 11 pages, no figur

    CoAP over ICN

    Full text link
    The Constrained Application Protocol (CoAP) is a specialized Web transfer protocol for resource-oriented applications intended to run on constrained devices, typically part of the Internet of Things. In this paper we leverage Information-Centric Networking (ICN), deployed within the domain of a network provider that interconnects, in addition to other terminals, CoAP endpoints in order to provide enhanced CoAP services. We present various CoAP-specific communication scenarios and discuss how ICN can provide benefits to both network providers and CoAP applications, even though the latter are not aware of the existence of ICN. In particular, the use of ICN results in smaller state management complexity at CoAP endpoints, simpler implementation at CoAP endpoints, and less communication overhead in the network.Comment: Proc. of the 8th IFIP International Conference on New Technologies, Mobility and Security (NTMS), Larnaca, Cyprus, November, 201
    corecore