Acín, A, Duan, R, Roberson, DE, Sainz, AB & Winter, A 2015, 'A new property of the Lovász number and duality relations between graph parameters', Discrete Applied Mathematics, vol. 216, no. 3, pp. 3-501.
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We show that for any graph $G$, by considering 'activation' through thestrong product with another graph $H$, the relation $\alpha(G) \leq\vartheta(G)$ between the independence number and the Lov\'{a}sz number of $G$can be made arbitrarily tight: Precisely, the inequality \[ \alpha(G \times H) \leq \vartheta(G \times H) = \vartheta(G)\,\vartheta(H) \]becomes asymptotically an equality for a suitable sequence of ancillary graphs$H$. This motivates us to look for other products of graph parameters of $G$ and$H$ on the right hand side of the above relation. For instance, a result ofRosenfeld and Hales states that \[ \alpha(G \times H) \leq \alpha^*(G)\,\alpha(H), \] with the fractionalpacking number $\alpha^*(G)$, and for every $G$ there exists $H$ that makes theabove an equality; conversely, for every graph $H$ there is a $G$ that attainsequality. These findings constitute some sort of duality of graph parameters, mediatedthrough the independence number, under which $\alpha$ and $\alpha^*$ are dualto each other, and the Lov\'{a}sz number $\vartheta$ is self-dual. We also showduality of Schrijver's and Szegedy's variants $\vartheta^-$ and $\vartheta^+$of the Lov\'{a}sz number, and explore analogous notions for the chromaticnumber under strong and disjunctive graph products.
Ambainis, A, Balodis, K, Belovs, A, Lee, T, Santha, M & Smotrovs, J 2015, 'Separations in Query Complexity Based on Pointer Functions', Journal of the ACM, vol. 64, no. 5.
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In 1986, Saks and Wigderson conjectured that the largest separation betweendeterministic and zero-error randomized query complexity for a total booleanfunction is given by the function $f$ on $n=2^k$ bits defined by a completebinary tree of NAND gates of depth $k$, which achieves $R_0(f) =O(D(f)^{0.7537\ldots})$. We show this is false by giving an example of a totalboolean function $f$ on $n$ bits whose deterministic query complexity is$\Omega(n/\log(n))$ while its zero-error randomized query complexity is $\tildeO(\sqrt{n})$. We further show that the quantum query complexity of the samefunction is $\tilde O(n^{1/4})$, giving the first example of a total functionwith a super-quadratic gap between its quantum and deterministic querycomplexities. We also construct a total boolean function $g$ on $n$ variables that haszero-error randomized query complexity $\Omega(n/\log(n))$ and bounded-errorrandomized query complexity $R(g) = \tilde O(\sqrt{n})$. This is the firstsuper-linear separation between these two complexity measures. The exactquantum query complexity of the same function is $Q_E(g) = \tilde O(\sqrt{n})$. These two functions show that the relations $D(f) = O(R_1(f)^2)$ and $R_0(f)= \tilde O(R(f)^2)$ are optimal, up to poly-logarithmic factors. Furthervariations of these functions give additional separations between other querycomplexity measures: a cubic separation between $Q$ and $R_0$, a $3/2$-powerseparation between $Q_E$ and $R$, and a 4th power separation betweenapproximate degree and bounded-error randomized query complexity. All of these examples are variants of a function recently introduced by\goos, Pitassi, and Watson which they used to separate the unambiguous1-certificate complexity from deterministic query complexity and to resolve thefamous Clique versus Independent Set problem in communication complexity.
Ban, Y & Chen, X 2015, 'Counter-diabatic driving for fast spin control in a two-electron double quantum dot', Scientific Reports, vol. 4, no. 1.
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Bandyopadhyay, S, Cosentino, A, Johnston, N, Russo, V, Watrous, J & Yu, N 2015, 'Limitations on Separable Measurements by Convex Optimization', IEEE Transactions on Information Theory, vol. 61, no. 6, pp. 3593-3604.
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© 1963-2012 IEEE. We prove limitations on LOCC and separable measurements in bipartite state discrimination problems using techniques from convex optimization. Specific results that we prove include: an exact formula for the optimal probability of correctly discriminating any set of either three or four Bell states via LOCC or separable measurements when the parties are given an ancillary partially entangled pair of qubits; an easily checkable characterization of when an unextendable product set is perfectly discriminated by separable measurements, along with the first known example of an unextendable product set that cannot be perfectly discriminated by separable measurements; and an optimal bound on the success probability for any LOCC or separable measurement for the recently proposed state discrimination problem of Yu, Duan, and Ying.
Berta, M & Tomamichel, M 2015, 'The Fidelity of Recovery is Multiplicative', IEEE Transactions on Information Theory, vol. 62, no. 4, pp. 1758-1763.
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Fawzi and Renner [Commun. Math. Phys. 340(2):575, 2015] recently establisheda lower bound on the conditional quantum mutual information (CQMI) oftripartite quantum states $ABC$ in terms of the fidelity of recovery (FoR),i.e. the maximal fidelity of the state $ABC$ with a state reconstructed fromits marginal $BC$ by acting only on the $C$ system. The FoR measures quantumcorrelations by the local recoverability of global states and has manyproperties similar to the CQMI. Here we generalize the FoR and show that theresulting measure is multiplicative by utilizing semi-definite programmingduality. This allows us to simplify an operational proof by Brandao et al.[Phys. Rev. Lett. 115(5):050501, 2015] of the above-mentioned lower bound thatis based on quantum state redistribution. In particular, in contrast to theprevious approaches, our proof does not rely on de Finetti reductions.
Berta, M, Fawzi, O & Tomamichel, M 2015, 'On Variational Expressions for Quantum Relative Entropies', Letters in Mathematical Physics, vol. 107, no. 12, pp. 2239-2265.
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Distance measures between quantum states like the trace distance and thefidelity can naturally be defined by optimizing a classical distance measureover all measurement statistics that can be obtained from the respectivequantum states. In contrast, Petz showed that the measured relative entropy,defined as a maximization of the Kullback-Leibler divergence over projectivemeasurement statistics, is strictly smaller than Umegaki's quantum relativeentropy whenever the states do not commute. We extend this result in two ways.First, we show that Petz' conclusion remains true if we allow general positiveoperator valued measures. Second, we extend the result to Renyi relativeentropies and show that for non-commuting states the sandwiched Renyi relativeentropy is strictly larger than the measured Renyi relative entropy for $\alpha\in (\frac12, \infty)$, and strictly smaller for $\alpha \in [0,\frac12)$. Thelatter statement provides counterexamples for the data-processing inequality ofthe sandwiched Renyi relative entropy for $\alpha < \frac12$. Our main tool isa new variational expression for the measured Renyi relative entropy, which wefurther exploit to show that certain lower bounds on quantum conditional mutualinformation are superadditive.
Bruno, A, de Lange, G, Asaad, S, van der Enden, KL, Langford, NK & DiCarlo, L 2015, 'Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substrates', Applied Physics Letters, vol. 106, no. 18, pp. 182601-182601.
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We present microwave-frequency NbTiN resonators on silicon, systematically achieving internal quality factors above 1 M in the quantum regime. We use two techniques to reduce losses associated with two-level systems: an additional substrate surface treatment prior to NbTiN deposition to optimize the metal-substrate interface and deep reactive-ion etching of the substrate to displace the substrate-vacuum interfaces away from high electric fields. The temperature and power dependence of resonator behavior indicate that two-level systems still contribute significantly to energy dissipation, suggesting that more interface optimization could further improve performance.
Bu, GP, Chanda, S, Guan, H, Jo, J, Blumenstein, M & Loo, YC 2015, 'Crack detection using a texture analysis-based technique for visual bridge inspection', Electronic Journal of Structural Engineering, vol. 14, no. 1, pp. 41-48.
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Bridge inspection is a pathway to bridge condition rating assessment, and is an essential element of any bridge management system (BMS). The success of a BMS is highly dependent on the quality of bridge inspection outcomes and accurate estimation of future bridge condition ratings. However, existing visual bridge inspection methods suffer several limitations due to human subjective judgment. In order to minimise such limitations, a feasibility study has been performed to enhance the current visual inspection method using optical image processing techniques. However, the accuracy of the inspection outcomes still requires further improvement. This paper proposes an automatic bridge inspection approach employing wavelet-based image features along with support vector machines (SVM) for automatic detection of cracks in bridge images. A two-stage approach is followed, in the first stage, a decision is made as whether an image should undergo a pre-processing step (depending on image characteristics); in the second stage, wavelet features are extracted from the image using a sliding window texture analysis-based technique. Consequently, an average accuracy of 92% (effect of training image types on accuracy) is obtained even when undertaking experiments with noisy and complex bridge images.
Bu, GP, Lee, JH, Guan, H, Loo, YC & Blumenstein, M 2015, 'Prediction of Long-Term Bridge Performance: Integrated Deterioration Approach with Case Studies', Journal of Performance of Constructed Facilities, vol. 29, no. 3, pp. 04014089-04014089.
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Chan, B, Guan, H, Jo, J & Blumenstein, M 2015, 'Towards UAV-based bridge inspection systems: a review and an application perspective', Structural Monitoring and Maintenance, vol. 2, no. 3, pp. 283-300.
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© 2015 Techno-Press, Ltd. Visual condition inspections remain paramount to assessing the current deterioration status of a bridge and assigning remediation or maintenance tasks so as to ensure the ongoing serviceability of the structure. However, in recent years, there has been an increasing backlog of maintenance activities. Existing research reveals that this is attributable to the labour-intensive, subjective and disruptive nature of the current bridge inspection method. Current processes ultimately require lane closures, traffic guidance schemes and inspection equipment. This not only increases the whole-of-life costs of the bridge, but also increases the risk to the travelling public as issues affecting the structural integrity may go unaddressed. As a tool for bridge condition inspections, Unmanned Aerial Vehicles (UAVs) or, drones, offer considerable potential, allowing a bridge to be visually assessed without the need for inspectors to walk across the deck or utilise under-bridge inspection units. With current inspection processes placing additional strain on the existing bridge maintenance resources, the technology has the potential to significantly reduce the overall inspection costs and disruption caused to the travelling public. In addition to this, the use of automated aerial image capture enables engineers to better understand a situation through the 3D spatial context offered by UAV systems. However, the use of UAV for bridge inspection involves a number of critical issues to be resolved, including stability and accuracy of control, and safety to people. SLAM (Simultaneous Localisation and Mapping) is a technique that could be used by a UAV to build a map of the bridge underneath, while simultaneously determining its location on the constructed map. While there are considerable economic and risk-related benefits created through introducing entirely new ways of inspecting bridges and visualising information, there also remain hindrances to...
Chen, J, Ji, Z, Yu, N & Zeng, B 2015, 'Detecting Consistency of Overlapping Quantum Marginals by Separability', Phys. Rev. A, vol. 93, no. 3, p. 032105.
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The quantum marginal problem asks whether a set of given density matrices areconsistent, i.e., whether they can be the reduced density matrices of a globalquantum state. Not many non-trivial analytic necessary (or sufficient)conditions are known for the problem in general. We propose a method to detectconsistency of overlapping quantum marginals by considering the separability ofsome derived states. Our method works well for the $k$-symmetric extensionproblem in general, and for the general overlapping marginal problems in somecases. Our work is, in some sense, the converse to the well-known $k$-symmetricextension criterion for separability.
Chen, J-Y, Ji, Z, Liu, Z-X, Shen, Y & Zeng, B 2015, 'Geometry of reduced density matrices for symmetry-protected topological phases', Phys. Rev. A, vol. 93, no. 1, p. 012309.
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In this paper, we study the geometry of reduced density matrices for stateswith symmetry-protected topological (SPT) order. We observe ruled surfacestructures on the boundary of the convex set of low dimension projections ofthe reduced density matrices. In order to signal the SPT order using ruledsurfaces, it is important that we add a symmetry-breaking term to the boundaryof the system---no ruled surface emerges in systems without boundary or when weadd a symmetry-breaking term representing a thermodynamic quantity. Althoughthe ruled surfaces only appear in the thermodynamic limit where theground-state degeneracy is exact, we analyze the precision of our numericalalgorithm and show that a finite system calculation suffices to reveal theruled surface structures.
Chen, T, Yu, N & Han, T 2015, 'Continuous-time orbit problems are decidable in polynomial-time', Information Processing Letters, vol. 115, no. 1, pp. 11-14.
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Cheng, H-C, Hsieh, M-H & Tomamichel, M 2015, 'Exponential Decay of Matrix $Φ$-Entropies on Markov Semigroups with Applications to Dynamical Evolutions of Quantum Ensembles', Journal of Mathematical Physics, 58(9), 092202, Sep 2017, vol. 58, no. 9.
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In the study of Markovian processes, one of the principal achievements is theequivalence between the $\Phi$-Sobolev inequalities and an exponential decreaseof the $\Phi$-entropies. In this work, we develop a framework of Markovsemigroups on matrix-valued functions and generalize the above equivalence tothe exponential decay of matrix $\Phi$-entropies. This result also specializesto spectral gap inequalities and modified logarithmic Sobolev inequalities inthe random matrix setting. To establish the main result, we define anon-commutative generalization of the carr\'e du champ operator, and prove a deBruijn's identity for matrix-valued functions. The proposed Markov semigroups acting on matrix-valued functions haveimmediate applications in the characterization of the dynamical evolution ofquantum ensembles. We consider two special cases of quantum unital channels,namely, the depolarizing channel and the phase-damping channel. In the former,since there exists a unique equilibrium state, we show that the matrix$\Phi$-entropy of the resulting quantum ensemble decays exponentially as timegoes on. Consequently, we obtain a stronger notion of monotonicity of theHolevo quantity - the Holevo quantity of the quantum ensemble decaysexponentially in time and the convergence rate is determined by the modifiedlog-Sobolev inequalities. However, in the latter, the matrix $\Phi$-entropy ofthe quantum ensemble that undergoes the phase-damping Markovian evolutiongenerally will not decay exponentially. This is because there are multipleequilibrium states for such a channel. Finally, we also consider examples of statistical mixing of Markov semigroupson matrix-valued functions. We can explicitly calculate the convergence rate ofa Markovian jump process defined on Boolean hypercubes, and provide upperbounds of the mixing time on these types of examples.
Chitambar, E & Hsieh, M-H 2015, 'Relating the Resource Theories of Entanglement and Quantum Coherence', Phys. Rev. Lett., vol. 117, no. 2, p. 020402.
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Quantum coherence and quantum entanglement represent two fundamental featuresof non-classical systems that can each be characterized within an operationalresource theory. In this paper, we unify the resource theories of entanglementand coherence by studying their combined behavior in the operational setting oflocal incoherent operations and classical communication (LIOCC). Specificallywe analyze the coherence and entanglement trade-offs in the tasks of stateformation and resource distillation. For pure states we identify the minimumcoherence-entanglement resources needed to generate a given state, and weintroduce a new LIOCC monotone that completely characterizes a state's optimalrate of bipartite coherence distillation. This result allows us to preciselyquantify the difference in operational powers between global incoherentoperations, LIOCC, and local incoherent operations \textit{without} classicalcommunication. Finally, a bipartite mixed state is shown to have distillableentanglement if and only if entanglement can be distilled by LIOCC, and westrengthen the well-known Horodecki criterion for distillability.
Chitambar, E, Fortescue, B & Hsieh, M-H 2015, 'A Classical Analog to Entanglement Reversibility', Phys. Rev. Lett., vol. 115, no. 9, pp. 090501-5.
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In this letter we introduce the problem of secrecy reversibility. This askswhen two honest parties can distill secret bits from some tripartitedistribution $p_{XYZ}$ and transform secret bits back into $p_{XYZ}$ at equalrates using local operation and public communication (LOPC). This is theclassical analog to the well-studied problem of reversibly concentrating anddiluting entanglement in a quantum state. We identify the structure ofdistributions possessing reversible secrecy when one of the honest partiesholds a binary distribution, and it is possible that all reversibledistributions have this form. These distributions are more general than what isobtained by simply constructing a classical analog to the family of quantumstates known to have reversible entanglement. An indispensable tool used in ouranalysis is a conditional form of the G\'{a}cs-K\'{o}rner Common Information.
Coles, PJ, Berta, M, Tomamichel, M & Wehner, S 2015, 'Entropic Uncertainty Relations and their Applications', Rev. Mod. Phys., vol. 89, no. 1, pp. 015002-58.
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Heisenberg's uncertainty principle forms a fundamental element of quantummechanics. Uncertainty relations in terms of entropies were initially proposedto deal with conceptual shortcomings in the original formulation of theuncertainty principle and, hence, play an important role in quantumfoundations. More recently, entropic uncertainty relations have emerged as thecentral ingredient in the security analysis of almost all quantum cryptographicprotocols, such as quantum key distribution and two-party quantum cryptography.This review surveys entropic uncertainty relations that capture Heisenberg'sidea that the results of incompatible measurements are impossible to predict,covering both finite- and infinite-dimensional measurements. These ideas arethen extended to incorporate quantum correlations between the observed objectand its environment, allowing for a variety of recent, more generalformulations of the uncertainty principle. Finally, various applications arediscussed, ranging from entanglement witnessing to wave-particle duality toquantum cryptography.
Combes, J & Ferrie, C 2015, 'Cost of postselection in decision theory', Physical Review A, vol. 92, no. 2, pp. 1-9.
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© 2015 American Physical Society. Postselection is the process of discarding outcomes from statistical trials that are not the event one desires. Postselection can be useful in many applications where the cost of getting the wrong event is implicitly high. However, unless this cost is specified exactly, one might conclude that discarding all data is optimal. Here we analyze the optimal decision rules and quantum measurements in a decision theoretic setting where a prespecified cost is assigned to discarding data. Our scheme interpolates between unambiguous state discrimination (when the cost of postselection is zero) and a minimum error measurement (when the cost of postselection is maximal). We also relate our formulation to previous approaches which focus on minimizing the probability of indecision.
Cui, SX, Yu, N & Zeng, B 2015, 'Generalized graph states based on Hadamard matrices', Journal of Mathematical Physics, vol. 56, no. 7, pp. 072201-072201.
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Graph states are widely used in quantum information theory, including entanglement theory, quantum error correction, and one-way quantum computing. Graph states have a nice structure related to a certain graph, which is given by either a stabilizer group or an encoding circuit, both can be directly given by the graph. To generalize graph states, whose stabilizer groups are abelian subgroups of the Pauli group, one approach taken is to study non-abelian stabilizers. In this work, we propose to generalize graph states based on the encoding circuit, which is completely determined by the graph and a Hadamard matrix. We study the entanglement structures of these generalized graph states and show that they are all maximally mixed locally. We also explore the relationship between the equivalence of Hadamard matrices and local equivalence of the corresponding generalized graph states. This leads to a natural generalization of the Pauli (X, Z) pairs, which characterizes the local symmetries of these generalized graph states. Our approach is also naturally generalized to construct graph quantum codes which are beyond stabilizer codes.
Dangniam, N & Ferrie, C 2015, 'Quantum Bochner’s theorem for phase spaces built on projective representations', Journal of Physics A: Mathematical and Theoretical, vol. 48, no. 11, pp. 115305-115305.
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Duan, R, Severini, S & Winter, A 2015, 'On zero-error communication via quantum channels in the presence of noiseless feedback', IEEE Trans. Inf. Theory, vol. 62, no. 9, pp. 9-5277.
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We initiate the study of zero-error communication via quantum channels whenthe receiver and sender have at their disposal a noiseless feedback channel ofunlimited quantum capacity, generalizing Shannon's zero-error communicationtheory with instantaneous feedback. We first show that this capacity is a function only of the linear span ofChoi-Kraus operators of the channel, which generalizes the bipartiteequivocation graph of a classical channel, and which we dub 'non-commutativebipartite graph'. Then we go on to show that the feedback-assisted capacity isnon-zero (with constant activating noiseless communication) if and only if thenon-commutative bipartite graph is non-trivial, and give a number of equivalentcharacterizations. This result involves a far-reaching extension of the'conclusive exclusion' of quantum states [Pusey/Barrett/Rudolph, Nature Phys.8:475-478]. We then present an upper bound on the feedback-assisted zero-error capacity,motivated by a conjecture originally made by Shannon and proved later byAhlswede. We demonstrate this bound to have many good properties, includingbeing additive and given by a minimax formula. We also prove that this quantityis the entanglement-assisted capacity against an adversarially chosen channelfrom the set of all channels with the same Choi-Kraus span, which can also beinterpreted as the feedback-assisted unambiguous capacity. The proof relies ona generalization of the 'Postselection Lemma' [Christandl/Koenig/Renner, PRL102:020504] that allows to reflect additional constraints, and which we believeto be of independent interest. We illustrate our ideas with a number of examples, includingclassical-quantum channels and Weyl diagonal channels, and close with anextensive discussion of open questions.
Ferrie, C & Blume-Kohout, R 2015, 'Minimax quantum tomography: the ultimate bounds on accuracy', Phys. Rev. Lett., vol. 116, no. 9, p. 090407.
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A minimax estimator has the minimum possible error ('risk') in the worstcase. We construct the first minimax estimators for quantum state tomographywith relative entropy risk. The minimax risk of non-adaptive tomography scalesas $O(1/\sqrt{N})$, in contrast to that of classical probability estimationwhich is $O(1/N)$. We trace this deficiency to sampling mismatch: futureobservations that determine risk may come from a different sample space thanthe past data that determine the estimate. This makes minimax estimators verybiased, and we propose a computationally tractable alternative with similarbehavior in the worst case, but superior accuracy on most states.
Ferrie, C & Combes, J 2015, 'Ferrie and Combes Reply:', Physical Review Letters, vol. 114, no. 11.
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Frati, F, Gaspers, S, Gudmundsson, J & Mathieson, L 2015, 'Augmenting Graphs to Minimize the Diameter', Algorithmica, vol. 72, no. 4, pp. 995-1010.
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© 2014, Springer Science+Business Media New York. We study the problem of augmenting a weighted graph by inserting edges of bounded total cost while minimizing the diameter of the augmented graph. Our main result is an FPT $$4$$4-approximation algorithm for the problem.
Friesen, M, Hamed, A, Lee, T & Oliver Theis, D 2015, 'Fooling-sets and rank', European Journal of Combinatorics, vol. 48, pp. 143-153.
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Granade, C, Ferrie, C & Cory, DG 2015, 'Accelerated randomized benchmarking', New Journal of Physics, vol. 17, no. 1, pp. 013042-013042.
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© 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Quantum information processing offers promising advances for a wide range of fields and applications, provided that we can efficiently assess the performance of the control applied in candidate systems. That is, we must be able to determine whether we have implemented a desired gate, and refine accordingly. Randomized benchmarking reduces the difficulty of this task by exploiting symmetries in quantum operations. Here, we bound the resources required for benchmarking and show that, with prior information, we can achieve several orders of magnitude better accuracy than in traditional approaches to benchmarking. Moreover, by building on state-of-the-art classical algorithms, we reach these accuracies with near-optimal resources. Our approach requires an order of magnitude less data to achieve the same accuracies and to provide online estimates of the errors in the reported fidelities. We also show that our approach is useful for physical devices by comparing to simulations.
Gross, JA, Dangniam, N, Ferrie, C & Caves, CM 2015, 'Novelty, efficacy, and significance of weak measurements for quantum tomography', Physical Review A, vol. 92, no. 6.
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Haah, J, Harrow, AW, Ji, Z, Wu, X & Yu, N 2015, 'Sample-optimal tomography of quantum states', IEEE Transactions on Information Theory, vol. 63, no. 9, pp. 5628-5641.
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It is a fundamental problem to decide how many copies of an unknown mixedquantum state are necessary and sufficient to determine the state. Previously,it was known only that estimating states to error $\epsilon$ in trace distancerequired $O(dr^2/\epsilon^2)$ copies for a $d$-dimensional density matrix ofrank $r$. Here, we give a theoretical measurement scheme (POVM) that requires$O (dr/ \delta ) \ln (d/\delta) $ copies of $\rho$ to error $\delta$ ininfidelity, and a matching lower bound up to logarithmic factors. This implies$O( (dr / \epsilon^2) \ln (d/\epsilon) )$ copies suffice to achieve error$\epsilon$ in trace distance. We also prove that for independent (product)measurements, $\Omega(dr^2/\delta^2) / \ln(1/\delta)$ copies are necessary inorder to achieve error $\delta$ in infidelity. For fixed $d$, our measurementcan be implemented on a quantum computer in time polynomial in $n$.
Hsieh, M-H & Watanabe, S 2015, 'Channel Simulation and Coded Source Compression', IEEE Transactions on Information Theory, vol. 62, no. 11, pp. 6609-6619, Nov. 2016, vol. 62, no. 11, pp. 6609-6619.
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Coded source compression, also known as source compression with helpers, hasbeen a major variant of distributed source compression, but has hithertoreceived little attention in the quantum regime. This work treats and solvesthe corresponding quantum coded source compression through an observation thatconnects coded source compression with channel simulation. First, we considerclassical source coding with quantum side information where the quantum sideinformation is observed by a helper and sent to the decoder via a classicalchannel. We derive a single-letter characterization of the achievable rateregion for this problem. The direct coding theorem of our result is proved viathe measurement compression theory of Winter, a quantum-to-classical channelsimulation. Our result reveals that a helper's scheme which separately conductsa measurement and a compression is suboptimal, and measurement compressionseems necessary to achieve the optimal rate region. We then study coded sourcecompression in the fully quantum regime, where two different scenarios areconsidered depending on the types of communication channels between thelegitimate source and the receiver. We further allow entanglement assistancefrom the quantum helper in both scenarios. We characterize the involved quantumresources, and derive single-letter expressions of the achievable rate region.The direct coding proofs are based on well-known quantum protocols, the quantumstate merging protocol and the fully quantum Slepian-Wolf protocol, togetherwith the quantum reverse Shannon theorem.
Ivanyos, G, Karpinski, M, Qiao, Y & Santha, M 2015, 'Generalized Wong sequences and their applications to Edmonds' problems', Journal of Computer and System Sciences, vol. 81, no. 7, pp. 1373-1386.
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© 2015 Elsevier Inc. Given a linear subspace B of the n×n matrices over some field F, we consider the following problems: symbolic matrix rank (SMR) asks to determine the maximum rank among matrices in B, while symbolic determinant identity testing (SDIT) asks to decide whether there exists a nonsingular matrix in B. The constructive versions of these problems ask to find a matrix of maximum rank, respectively a nonsingular matrix, if there exists one. Our first algorithm solves the constructive SMR when B is spanned by unknown rank one matrices, answering an open question of Gurvits. Our second algorithm solves the constructive SDIT when B is spanned by triangularizable matrices. (The triangularization is not given explicitly.) Both algorithms work over fields of size ≥n+1. Our framework is based on generalizing Wong sequences, a classical method to deal with pairs of matrices, to pairs of matrix spaces.
Kueng, R & Ferrie, C 2015, 'Near-optimal quantum tomography: estimators and bounds', New J. Phys., vol. 17, p. 123013.
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We give bounds on the average fidelity achievable by any quantum stateestimator, which is arguably the most prominently used figure of merit inquantum state tomography. Moreover, these bounds can be computed online---thatis, while the experiment is running. We show numerically that these bounds arequite tight for relevant distributions of density matrices. We also show thatthe Bayesian mean estimator is ideal in the sense of performing close to thebound without requiring optimization. Our results hold for all finitedimensional quantum systems.
Kulkarni, R, Qiao, Y & Sun, X 2015, 'Any monotone property of 3-uniform hypergraphs is weakly evasive', Theoretical Computer Science, vol. 588, pp. 16-23.
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© 2014 Elsevier B.V. For a Boolean function f, let D(f) denote its deterministic decision tree complexity, i.e., minimum number of (adaptive) queries required in worst case in order to determine f. In a classic paper, Rivest and Vuillemin [11] show that any non-constant monotone property P:{0,1}(n2)→{0,1} of n-vertex graphs has D(P)=Ω(n2).We extend their result to 3-uniform hypergraphs. In particular, we show that any non-constant monotone property P:{0,1}(n3)→{0,1} of n-vertex 3-uniform hypergraphs has D(P)=Ω(n3).Our proof combines the combinatorial approach of Rivest and Vuillemin with the topological approach of Kahn, Saks, and Sturtevant [6]. Interestingly, our proof makes use of Vinogradov's Theorem (weak Goldbach Conjecture), inspired by its recent use by Babai et al. [1] in the context of the topological approach. Our work leaves the generalization to k-uniform hypergraphs as an intriguing open question.
Lee, Y-C, Liu, J, Chuang, Y-L, Hsieh, M-H & Lee, R-K 2015, 'Passive $\mathcal{PT}$-symmetric couplers without complex optical potentials', Phys. Rev. A, vol. 92, no. 5, pp. 053815-4.
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In addition to the implementation of parity-time ($\mathcal{PT}$)-symmetricoptical systems by carefully and actively controlling the gain and loss, weshow that a $2\times 2$ $\mathcal{PT}$-symmetric Hamiltonian has a unitarilyequivalent representation without complex optical potentials in the resultingoptical coupler. Through the Naimark dilation in operator algebra, passive$\mathcal{PT}$-symmetric couplers can thus be implemented with a refractiveindex of real values and asymmetric coupling coefficients. This opens up thepossibility to implement general $\mathcal{PT}$-symmetric systems withstate-of-the-art asymmetric slab waveguides, dissimilar optical fibers, orcavities with chiral mirrors.
Leung, D & Yu, N 2015, 'Maximum privacy without coherence, zero-error', Journal of Mathematical Physics, vol. 57, no. 9, p. 092202.
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We study the possible difference between the quantum and the privatecapacities of a quantum channel in the zero-error setting. For a family ofchannels introduced by arXiv:1312.4989, we demonstrate an extreme difference:the zero-error quantum capacity is zero, whereas the zero-error privatecapacity is maximum given the quantum output dimension.
Li, N, Ferrie, C, Gross, JA, Kalev, A & Caves, CM 2015, 'Fisher-symmetric informationally complete measurements for pure states', Phys. Rev. Lett., vol. 116, no. 18, pp. 180402-180402.
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We introduce a new kind of quantum measurement that is defined to besymmetric in the sense of uniform Fisher information across a set of parametersthat injectively represent pure quantum states in the neighborhood of afiducial pure state. The measurement is locally informationallycomplete---i.e., it uniquely determines these parameters, as opposed todistinguishing two arbitrary quantum states---and it is maximal in the sense ofa multi-parameter quantum Cramer-Rao bound. For a $d$-dimensional quantumsystem, requiring only local informational completeness allows us to reduce thenumber of outcomes of the measurement from a minimum close to but below $4d-3$,for the usual notion of global pure-state informational completeness, to$2d-1$.
Lu, D, Xin, T, Yu, N, Ji, Z, Chen, J, Long, G, Baugh, J, Peng, X, Zeng, B & Laflamme, R 2015, 'Tomography is necessary for universal entanglement detection with single-copy observables', Phys. Rev. Lett., vol. 116, no. 23, p. 230501.
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Entanglement, one of the central mysteries of quantum mechanics, plays anessential role in numerous applications of quantum information theory. Anatural question of both theoretical and experimental importance is whetheruniversal entanglement detection is possible without full state tomography. Inthis work, we prove a no-go theorem that rules out this possibility for anynon-adaptive schemes that employ single-copy measurements only. We also examinein detail a previously implemented experiment, which claimed to detectentanglement of two-qubit states via adaptive single-copy measurements withoutfull state tomography. By performing the experiment and analyzing the data, wedemonstrate that the information gathered is indeed sufficient to reconstructthe state. These results reveal a fundamental limit for single-copymeasurements in entanglement detection, and provides a general framework tostudy the detection of other interesting properties of quantum states, such asthe positivity of partial transpose and the $k$-symmetric extendibility.
Mandal, R, Roy, PP, Pal, U & Blumenstein, M 2015, 'Multi-lingual date field extraction for automatic document retrieval by machine', Information Sciences, vol. 314, pp. 277-292.
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© 2014 Elsevier Inc. All rights reserved. Robotic intelligence has recently received significant attention in the research community. Application of such artificial intelligence can be used to perform automatic document retrieval and interpretation by a robot through query. So, it is necessary to extract the key information from the document based on the query to produce the desired feedback. For this purpose, in this paper we propose a system for automatic date field extraction from multi-lingual (English, Devnagari and Bangla scripts) handwritten documents. The date is a key piece of information, which can be used in various robotic applications such as date-wise document indexing/retrieval. In order to design the system, first the script of the document is identified, and based on the identified script, word components of each text line are classified into month and non-month classes using word-level feature extraction and classification. Next, non-month words are segmented into individual components and labelled into one of text, digit, punctuation or contraction categories. Subsequently, the date patterns are searched using the labelled components. Both numeric and semi-numeric regular expressions have been used for date part extraction. Dynamic Time Warping (DTW) and profile feature-based approaches are used for classification of month/non-month words. Other date components such as numerals and punctuation marks are recognised using a gradient-based feature and Support Vector Machine (SVM) classifier. The experiments are performed on English, Devnagari and Bangla document datasets and the encouraging results obtained from the system indicate the effectiveness of the proposed system.
Mathieson, L 2015, 'Graph Editing Problems with Extended Regularity Constraints', Theoretical Computer Science, vol. 677, pp. 56-68.
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Graph editing problems offer an interesting perspective on sub- andsupergraph identification problems for a large variety of target properties.They have also attracted significant attention in recent years, particularly inthe area of parameterized complexity as the problems have rich parameterecologies. In this paper we examine generalisations of the notion of editing a graph toobtain a regular subgraph. In particular we extend the notion of regularity toinclude two variants of edge-regularity along with the unifying constraint ofstrong regularity. We present a number of results, with the central observationthat these problems retain the general complexity profile of theirregularity-based inspiration: when the number of edits $k$ and the maximumdegree $r$ are taken together as a combined parameter, the problems aretractable (i.e. in \FPT{}), but are otherwise intractable. We also examine variants of the basic editing to obtain a regular subgraphproblem from the perspective of parameterizing by the treewidth of the inputgraph. In this case the treewidth of the input graph essentially becomes alimiting parameter on the natural $k+r$ parameterization.
Paler, A, Polian, I, Nemoto, K & Devitt, SJ 2015, 'Fault-Tolerant High Level Quantum Circuits: Form, Compilation and Description', Quantum Science and Technology, vol. 2, no. 2, p. 025003.
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Fault-tolerant quantum error correction is a necessity for any quantumarchitecture destined to tackle interesting, large-scale problems. Itstheoretical formalism has been well founded for nearly two decades. However, westill do not have an appropriate compiler to produce a fault-tolerant, errorcorrected description from a higher level quantum circuit for state of the arthardware models. There are many technical hurdles, including dynamic circuitconstructions that occur when constructing fault-tolerant circuits withcommonly used error correcting codes. We introduce a package that converts highlevel quantum circuits consisting of commonly used gates into a form employingall decompositions and ancillary protocols needed for fault-tolerant errorcorrection. We call this form the (I)initialisation, (C)NOT, (M)measurementform (ICM) and consists of an initialisation layer of qubits into one of fourdistinct states, a massive, deterministic array of CNOT operations and a seriesof time ordered $X$- or $Z$-basis measurements. The form allows a more flexbileapproach towards circuit optimisation. At the same time, the package outputs astandard circuit or a canonical geometric description which is a necessity foroperating current state-of-the-art hardware architectures using topologicalquantum codes.
Pfister, C, Kaniewski, J, Tomamichel, M, Mantri, A, Schmucker, R, McMahon, N, Milburn, G & Wehner, S 2015, 'Understanding nature from experimental observations: a theory independent test for gravitational decoherence', Nature Communications, vol. 7, pp. 13022-13022.
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Quantum mechanics and the theory of gravity are presently not compatible. Aparticular question is whether gravity causes decoherence - an unavoidablesource of noise. Several models for gravitational decoherence have beenproposed, not all of which can be described quantum mechanically. In parallel,several experiments have been proposed to test some of these models, where thedata obtained by such experiments is analyzed assuming quantum mechanics. Sincewe may need to modify quantum mechanics to account for gravity, however, onemay question the validity of using quantum mechanics as a calculational tool todraw conclusions from experiments concerning gravity. Here we propose an experiment to estimate gravitational decoherence whoseconclusions hold even if quantum mechanics would need to be modified. We firstestablish a general information-theoretic notion of decoherence which reducesto the standard measure within quantum mechanics. Second, drawing on ideas fromquantum information, we propose a very general experiment that allows us toobtain a quantitative estimate of decoherence of any physical process for anyphysical theory satisfying only very mild conditions.Finally, we propose aconcrete experiment using optomechanics to estimate gravitational decoherencein any such theory, including quantum mechanics as a special case. Our work raises the interesting question whether other properties of naturecould similarly be established from experimental observations alone - that is,without already having a rather well formed theory of nature like quantummechanics to make sense of experimental data.
Ross, PK & Blumenstein, M 2015, 'Cloud computing as a facilitator of SME entrepreneurship', Technology Analysis & Strategic Management, vol. 27, no. 1, pp. 87-101.
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Sharma, N, Shivakumara, P, Pal, U, Blumenstein, M & Tan, CL 2015, 'Piece-wise linearity based method for text frame classification in video', Pattern Recognition, vol. 48, no. 3, pp. 862-881.
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Sutter, D, Tomamichel, M & Harrow, AW 2015, 'Strengthened Monotonicity of Relative Entropy via Pinched Petz Recovery Map', IEEE Transactions on Information Theory, vol. 62, no. 5, pages 2907-2913, 2016, vol. 62, no. 5, pp. 2907-2913.
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The quantum relative entropy between two states satisfies a monotonicityproperty meaning that applying the same quantum channel to both states cannever increase their relative entropy. It is known that this inequality is onlytight when there is a 'recovery map' that exactly reverses the effects of thequantum channel on both states. In this paper we strengthen this inequality byshowing that the difference of relative entropies is bounded below by themeasured relative entropy between the first state and a recovered state fromits processed version. The recovery map is a convex combination of rotated Petzrecovery maps and perfectly reverses the quantum channel on the second state.As a special case we reproduce recent lower bounds on the conditional mutualinformation such as the one proved in [Fawzi and Renner, Commun. Math. Phys.,2015]. Our proof only relies on elementary properties of pinching maps and theoperator logarithm.
Tomamichel, M & Hayashi, M 2015, 'Operational Interpretation of Renyi Information Measures via Composite Hypothesis Testing Against Product and Markov Distributions', IEEE Transactions on Information Theory, vol. 64, no. 2, pp. 1064-1082.
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We revisit the problem of asymmetric binary hypothesis testing against acomposite alternative hypothesis. We introduce a general framework to treatsuch problems when the alternative hypothesis adheres to certain axioms. Inthis case we find the threshold rate, the optimal error and strong converseexponents (at large deviations from the threshold) and the second orderasymptotics (at small deviations from the threshold). We apply our results tofind operational interpretations of various Renyi information measures. In casethe alternative hypothesis is comprised of bipartite product distributions, wefind that the optimal error and strong converse exponents are determined byvariations of Renyi mutual information. In case the alternative hypothesisconsists of tripartite distributions satisfying the Markov property, we findthat the optimal exponents are determined by variations of Renyi conditionalmutual information. In either case the relevant notion of Renyi mutualinformation depends on the precise choice of the alternative hypothesis. Assuch, our work also strengthens the view that different definitions of Renyimutual information, conditional entropy and conditional mutual information areadequate depending on the context in which the measures are used.
Tomamichel, M & Leverrier, A 2015, 'A largely self-contained and complete security proof for quantum key distribution', Quantum, vol. 1, pp. 14-52.
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In this work we present a security analysis for quantum key distribution,establishing a rigorous tradeoff between various protocol and securityparameters for a class of entanglement-based and prepare-and-measure protocols.The goal of this paper is twofold: 1) to review and clarify thestate-of-the-art security analysis based on entropic uncertainty relations, and2) to provide an accessible resource for researchers interested in a securityanalysis of quantum cryptographic protocols that takes into account finiteresource effects. For this purpose we collect and clarify several argumentsspread in the literature on the subject with the goal of making this treatmentlargely self-contained. More precisely, we focus on a class of prepare-and-measure protocols based onthe Bennett-Brassard (BB84) protocol as well as a class of entanglement-basedprotocols similar to the Bennett-Brassard-Mermin (BBM92) protocol. We carefullyformalize the different steps in these protocols, including randomization,measurement, parameter estimation, error correction and privacy amplification,allowing us to be mathematically precise throughout the security analysis. Westart from an operational definition of what it means for a quantum keydistribution protocol to be secure and derive simple conditions that serve assufficient condition for secrecy and correctness. We then derive and eventuallydiscuss tradeoff relations between the block length of the classicalcomputation, the noise tolerance, the secret key length and the securityparameters for our protocols. Our results significantly improve upon previouslyreported tradeoffs.
Tomamichel, M, Berta, M & Renes, JM 2015, 'Quantum Coding with Finite Resources', Nature Communications 7:11419 (2016), vol. 7.
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The quantum capacity of a memoryless channel is often used as a single figureof merit to characterize its ability to transmit quantum informationcoherently. The capacity determines the maximal rate at which we can codereliably over asymptotically many uses of the channel. We argue that thisasymptotic treatment is insufficient to the point of being irrelevant in thequantum setting where decoherence severely limits our ability to manipulatelarge quantum systems in the encoder and decoder. For all practical purposes weshould instead focus on the trade-off between three parameters: the rate of thecode, the number of coherent uses of the channel, and the fidelity of thetransmission. The aim is then to specify the region determined by allowedcombinations of these parameters. Towards this goal, we find approximate andexact characterizations of the region of allowed triplets for the qubitdephasing channel and for the erasure channel with classical post-processingassistance. In each case the region is parametrized by a second channelparameter, the quantum channel dispersion. In the process we also developseveral general inner (achievable) and outer (converse) bounds on the codingregion that are valid for all finite-dimensional quantum channels and can becomputed efficiently. Applied to the depolarizing channel, this allows us todetermine a lower bound on the number of coherent uses of the channel necessaryto witness super-additivity of the coherent information.
Yu, N 2015, 'Separability of Bosonic Systems', Phys. Rev. A, vol. 94, no. 6, p. 060101.
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In this paper, we study the separability of quantum states in bosonic system.Our main tool here is the 'separability witnesses', and a connection between'separability witnesses' and a new kind of positivity of matrices--- 'PowerPositive Matrices' is drawn. Such connection is employed to demonstrate thatmulti-qubit quantum states with Dicke states being its eigenvectors isseparable if and only if two related Hankel matrices are positive semidefinite.By employing this criterion, we are able to show that such state is separableif and only if it's partial transpose is non-negative, which confirms theconjecture in [Wolfe, Yelin, Phys. Rev. Lett. (2014)]. Then, we present a classof bosonic states in $d\otimes d$ system such that for general $d$, determineits separability is NP-hard although verifiable conditions for separability iseasily derived in case $d=3,4$.
Yu, N & Ying, M 2015, 'Optimal simulation of Deutsch gates and the Fredkin gate', PHYSICAL REVIEW A, vol. 91, no. 3.
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Zhao, Y-Y, Yu, N-K, Kurzynski, P, Xiang, G-Y, Li, C-F & Guo, G-C 2015, 'Experimental realisation of generalised qubit measurements based on quantum walks', Physical Review A - Atomic, Molecular, and Optical Physics, vol. 91, no. 4.
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We report an experimental implementation of a single-qubit generalisedmeasurement scenario(POVM) based on a quantum walk model. The qubit is encodedin a single-photon polarisation. The photon performs a quantum walk on an arrayof optical elements, where the polarisation-dependent translation is performedvia birefringent beam displacers and a change of the polarisation isimplemented with the help of wave-plates. We implement: (i) Trine-POVM, i.e.,the POVM elements uniformly distributed on an equatorial plane of the Blochsphere; (ii) Symmetric-Informationally- Complete (SIC) POVM; and (iii)Unambiguous Discrimination of two non-orthogonal qubit states.
Zhou, B, Xu, G & Li, S 2015, 'The Quintuple Implication Principle of fuzzy reasoning', Information Sciences, vol. 297, pp. 202-215.
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© 2014 Elsevier Inc. Fuzzy Modus Ponens (FMP) and Fuzzy Modus Tollens (FMT) are two fundamental patterns of approximate reasoning. Suppose A and B are fuzzy predicates and 'IF A THEN B' is a fuzzy rule. Approximate reasoning often requires to derive an approximation A∗ of B from a given approximation A∗ of A, or vice versa. To solve these problems, Zadeh introduces the well-known Compositional Rule of Inference (CRI), which models fuzzy rule by implication and computes A∗ (A∗, resp.) by composing A∗ (A∗, resp.) with A→B. Wang argues that the use of the compositional operation is logically not sufficiently justified and proposes the Triple Implication Principle (TIP) instead. Both CRI and TIP do not explicitly use the closeness of A and A∗ (or that of B and A∗) in the process of calculating the consequence, which makes the thus computed approximation sometimes useless or misleading. In this paper, we propose the Quintuple Implication Principle (QIP) for fuzzy reasoning, which characterizes the approximation A∗ of B (A∗ of A, resp.) as the formula which is best supported by A→B,A∗→A and A∗ (A→B,B→A∗ and A∗, resp.). Based upon Monoidal t-norm Logic (MTL), this paper applies QIP to solve FMP and FMT for four important implications. Most importantly, we show that QIP, when using Gödel implication, computes exactly the same approximation as Mamdani-type fuzzy inference does. This is surprising as Mamdani interprets fuzzy rules in terms of the minimum operation, while CRI, TIP and QIP all interpret fuzzy rules in terms of implication.
Adak, C, Maitra, P, Chaudhuri, BB & Blumenstein, M 1970, 'Binarization of old halftone text documents', TENCON 2015 - 2015 IEEE Region 10 Conference, TENCON 2015 - 2015 IEEE Region 10 Conference, IEEE, Macao, PEOPLES R CHINA, pp. 1-5.
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© 2015 IEEE. A degraded document image should be cleaned before subjecting to Optical Character Recognition (OCR), otherwise the result may be erroneous. Though major studies have been conducted on degraded document image cleaning, halftone documents received less attention. Since halftone documents contain halftone dot patterns, classical binarization techniques do not produce proper output for feeding into the OCR engine. In this paper, old halftone documents are considered for text area cleaning and binarization. At the beginning, the zone of interest (text area) is found using local binary pattern and contour analysis. Reasonably smaller zones are filtered out as noise. Then the foreground pixels are separated using background estimation. After this, an automated spatial smoothing technique is employed on the foreground. At last, a local binarization technique is used to produce the binary image. The proposed method is tested on various old and degraded halftone documents, which has produced fairly good results.
Bremner, MJ, Montanaro, A & Shepherd, D 1970, 'Average-case complexity versus approximate simulation of commuting quantum computations', 15th Asian Quantum Information Science Conference, Seoul, Korea.
Chitambar, E, Fortescue, B & Hsieh, M-H 1970, 'Distributions Attaining Secret Key at a Rate of the Conditional Mutual Information', Advances in Cryptology -- CRYPTO 2015, Volume 9216 of the series Lecture Notes in Computer Science pp. 443-462, 2015, Annual International Cryptology Conference, SPRINGER-VERLAG BERLIN, Santa Barbara, CA, pp. 443-462.
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In this paper we consider the problem of extracting secret key from aneavesdropped source $p_{XYZ}$ at a rate given by the conditional mutualinformation. We investigate this question under three different scenarios: (i)Alice ($X$) and Bob ($Y$) are unable to communicate but share common randomnesswith the eavesdropper Eve ($Z$), (ii) Alice and Bob are allowed one-way publiccommunication, and (iii) Alice and Bob are allowed two-way publiccommunication. Distributions having a key rate of the conditional mutualinformation are precisely those in which a 'helping' Eve offers Alice and Bobno greater advantage for obtaining secret key than a fully adversarial one. Foreach of the above scenarios, strong necessary conditions are derived on thestructure of distributions attaining a secret key rate of $I(X:Y|Z)$. Inobtaining our results, we completely solve the problem of secret keydistillation under scenario (i) and identify $H(S|Z)$ to be the optimal keyrate using shared randomness, where $S$ is the G\'acs-K\'orner CommonInformation. We thus provide an operational interpretation of the conditionalG\'acs-K\'orner Common Information. Additionally, we introduce simple exampledistributions in which the rate $I(X:Y|Z)$ is achievable if and only if two-waycommunication is allowed.
Connor, M, Ghapanchi, AH, Blumenstein, M, Amrollahi, A & Najaftorkaman, M 1970, 'Decision Support Systems and Line Performance: Case of Gold Coast University Hospital.', Stud Health Technol Inform, National Health Informatics Conference, IOS Press, Netherlands, pp. 22-28.
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Computer-based decision support information systems have been promoted for their potential to improve physician performance and patient outcomes and support clinical decision making. The current case study reported design and implementation of a high-level decision support system (DSS) which facilitated the flow of data from operational level to top managers and leadership level of hospitals. The results shows that development of a DSS improve data connectivity, timing, and responsiveness issues via centralised sourcing and storing of principal health-related information in the hospital. The implementation of the system has resulted in significant enhancements in outpatient waiting times management.
Dasa, A, Palb, U, Ferrerc, MA & Blumensteina, M 1970, 'SSBC 2015: Sclera segmentation benchmarking competition', 2015 IEEE 7th International Conference on Biometrics Theory, Applications and Systems (BTAS), 2015 IEEE 7th International Conference on Biometrics Theory, Applications and Systems (BTAS), IEEE.
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Datta, N, Tomamichel, M & Wilde, MM 1970, 'Second-order coding rates for entanglement-assisted communication', 2015 IEEE International Symposium on Information Theory (ISIT), 2015 IEEE International Symposium on Information Theory (ISIT), IEEE, Hong Kong, China, pp. 2772-2776.
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© 2015 IEEE. The entanglement-assisted capacity of a quantum channel is known to provide the formal quantum generalization of Shannon's classical channel capacity theorem, in the sense that it admits a single-letter characterization in terms of the quantum mutual information and does not increase in the presence of a noiseless quantum feedback channel from receiver to sender. In this work, we investigate second-order asymptotics of the entanglement-assisted communication task. That is, we consider how quickly the rates of entanglement-assisted codes converge to the entanglement-assisted capacity of a channel as a function of the number of channel uses and the error tolerance. We define a quantum generalization of the mutual information variance of a channel in the entanglement-assisted setting. For covariant channels, we show that this quantity is equal to the channel dispersion, and characterizes the convergence towards the entanglement-assisted capacity when the number of channel uses increases. More generally, we prove that the Gaussian approximation for a second-order coding rate is achievable for all quantum channels.
Fazel, SAA, Mirfenderesk, H, Tomlinson, R & Blumenstein, M 1970, 'Towards robust flood forecasts using neural networks', 2015 International Joint Conference on Neural Networks (IJCNN), 2015 International Joint Conference on Neural Networks (IJCNN), IEEE, Killarney, Ireland.
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© 2015 IEEE. In this paper, design of a neural network for a domain-specific problem is described. The problem of concern is forecasting flood events where data is contaminated heavily by noise, training examples have different importance levels and noisy data coincides with the most important ones. To this end, two ideas are explored namely, changing the loss function and integrating a coefficient that reflects on the relative importance of training examples. To this end, backpropagation is re-derived considering implication of having a more general objective function. Independently, inclusion of scores associated with each training examples and its implication of overall loss function and the way weights are optimized is explored. The derived model is implemented in MATLAB and flood data from Talebudgera, Australia is considered for investigations. Compared to the base case being backpropagation, the results suggest that inclusion of scored for training examples corresponds to visible improvement when predicting peaks.
Ghanbarzadeh, R, Ghapanchi, AH & Blumenstein, M 1970, 'Characteristics of Research on the Application of Three-Dimensional Immersive Virtual Worlds in Health', Health Information Science (LNCS), International Conference on Health Information Science (HIS), Springer International Publishing, Melbourne, Australia, pp. 213-224.
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© Springer International Publishing Switzerland 2015. Three-dimensional immersive virtual worlds (3DVW) offer researchers and health professionals the opportunities to experiment with their rich communication, collaboration, virtual and 3D content creation integrated tools. This study presents the results of a systematic literature review conducted on the adoption of 3DVWs in the health care sector. Our systematic review began with an initial set of 1088 studies from five major and top-ranking scientific databases published from 1990 to 2013 which have used 3DVWs in health. We found a large quantity of application areas for the 3DVWs in health care, and classified them into two main categories: educational and non-educational applications. We also analyzed different 3DVW platforms and virtual environments which have been used in health care, as well as the avatar-mediated roles these applications, and frequency of papers in different countries. Our findings can be very insightful for the health care community and researchers.
Grochow, JA & Qiao, Y 1970, 'Polynomial-time isomorphism test of groups that are tame extensions (Extended abstract)', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), pp. 578-589.
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We give new polynomial-time algorithms for testing isomorphism of a class of groups given by multiplication tables (GpI). Two results (Cannon & Holt, J. Symb. Comput. 2003; Babai, Codenotti & Qiao, ICALP 2012) imply that GpI reduces to the following: given groups G,H with characteristic subgroups of the same type and isomorphic to ℤdp , and given the coset of isomorphisms Iso(G/ℤdp ,H/ℤdp), compute Iso(G,H) in time poly(|G|). Babai&Qiao (STACS 2012) solved this problem when a Sylow p-subgroup of G/ℤdp is trivial. In this paper, we solve the preceding problem in the so-called “tame” case, i. e., when a Sylow p-subgroup of G/ℤdp is cyclic, dihedral, semi-dihedral, or generalized quaternion. These cases correspond exactly to the group algebra (Formula presented.) being of tame type, as in the celebrated tame-wild dichotomy in representation theory. We then solve new cases of GpI in polynomial time. Our result relies crucially on the divide-and-conquer strategy proposed earlier by the authors (CCC 2014), which splits GpI into two problems, one on group actions (representations), and one on group cohomology. Based on this strategy, we combine permutation group and representation algorithms with new mathematical results, including bounds on the number of indecomposable representations of groups in the tame case, and on the size of their cohomology groups. Finally, we note that when a group extension is not tame, the preceding bounds do not hold. This suggests a precise sense in which the tame-wild dichotomy from representation theory may also be a key barrier to cross to put GpI into P.
Grochow, JA & Qiao, Y 1970, 'Polynomial-Time Isomorphism Test of Groups that are Tame Extensions (Extended Abstract)', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), pp. 578-589.
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We give new polynomial-time algorithms for testing isomorphism of a class of groups given by multiplication tables (GpI). Two results (Cannon & Holt, J. Symb. Comput. 2003; Babai, Codenotti & Qiao, ICALP 2012) imply that GpI reduces to the following: Given groups G,H with characteristic subgroups of the same type and isomorphic to Zdp, and given the coset of isomorphisms Iso(G/Zdp,H/Zdp), compute Iso(G,H) in time poly(|G|). Babai&Qiao (STACS 2012) solved this problem when a Sylow p-subgroup of G/Zdp is trivial. In this paper, we solve the preceding problem in the so-called “tame” case, i. e., when a Sylow p-subgroup of G/Zdp is cyclic, dihedral, semi-dihedral, or generalized quaternion. These cases correspond exactly to the group algebra Fp[G/Zdp] being of tame type, as in the celebrated tame-wild dichotomy in representation theory. We then solve new cases of GpI in polynomial time. Our result relies crucially on the divide-and-conquer strategy proposed earlier by the authors (CCC 2014), which splits GpI into two problems, one on group actions (representations), and one on group cohomology. Based on this strategy, we combine permutation group and representation algorithms with new mathematical results, including bounds on the number of indecomposable representations of groups in the tame case, and on the size of their cohomology groups. Finally, we note that when a group extension is not tame, the preceding bounds do not hold. This suggests a precise sense in which the tame-wild dichotomy from representation theory may also be a key barrier to cross to put GpI into P.
Hayashi, M & Tomamichel, M 1970, 'Correlation detection and an operational interpretation of the Rényi mutual information', 2015 IEEE International Symposium on Information Theory (ISIT), 2015 IEEE International Symposium on Information Theory (ISIT), IEEE, Hong Kong, China, pp. 1447-1451.
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Hsieh, M-H & Watanabe, S 1970, 'Fully Quantum Source Compression with a Quantum Helper', 2015 IEEE Information Theory Workshop, pp. 307-311, 2015, Information Theory Workshop, IEEE, Jeju, pp. 307-311.
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We study source compression with a helper in the fully quantum regime,extending our earlier result on classical source compression with a quantumhelper [arXiv:1501.04366, 2015]. We characterise the quantum resources involvedin this problem, and derive a single-letter expression of the achievable rateregion when entanglement assistance is available. The direct coding proof isbased on a combination of two fundamental protocols, namely the quantum statemerging protocol and the quantum reverse Shannon theorem (QRST). This resultdemonstrates an unexpected connection between distributed source compressionwith the QRST protocol, a quantum protocol that consumes noiseless resources tosimulate a noisy quantum channel.
Hsieh, M-H & Watanabe, S 1970, 'Source Compression with a Quantum Helper', 2015 IEEE International Symposium on Information Theory (ISIT), pp. 2762-2766, 2015, IEEE International Symposium on Information Theory, IEEE, Hong Kong, pp. 2762-2766.
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We study classical source coding with quantum side-information where thequantum side-information is observed by a helper and sent to the decoder via aclassical channel. We derive a single-letter characterization of the achievablerate region for this problem. The direct part of our result is proved via themeasurement compression theory by Winter. Our result reveals that a helper'sscheme that separately conducts a measurement and a compression is suboptimal,and the measurement compression is fundamentally needed to achieve the optimalrate region.
Kaniewski, J, Lee, T & de Wolf, R 1970, 'Query Complexity in Expectation', Springer Berlin Heidelberg, pp. 761-772.
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Khosravi, P, Ghapanchi, AH & Blumenstein, M 1970, 'Investigating Various Technologies Applied to Assist Seniors', Health Information Science (LNCS), International Conference on Health Information Science (HIS), Springer International Publishing, Melbourne, Australia, pp. 202-212.
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© Springer International Publishing Switzerland 2015. This study undertakes a systematic literature review to investigate current empirical studies on the assistive technologies applied in aged care. Our systematic review of 54 studies published from 2000 to 2014 examines the role of assistive technologies in seniors’ daily lives, from enhancements in their mobility to improvements in the social connectedness and decreases in readmission to hospitals. We found eight key issues in aged care that have been targeted by ICT researchers. We also identified the assistive technologies that have been proposed to overcome those problems, and we categorised these assistive technologies into six clusters. Our analysis showed significant growth in the number of publications in this area in the past few years. It also showed that most of the studies in this area have been conducted in North America.
Kulkarni, R, Qiao, Y & Sun, X 1970, 'On the Power of Parity Queries in Boolean Decision Trees', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Conference on Theory and Applications of Models of Computation, Springer International Publishing, Singapore, pp. 99-109.
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© Springer International Publishing Switzerland 2015. In an influential paper,Kushilevitz and Mansour (1993) introduced a natural extension of Boolean decision trees called parity decision tree (PDT) where one may query the sum modulo 2, i.e., the parity, of an arbitrary subset of variables. Although originally introduced in the context of learning, parity decision trees have recently regained interest in the context of communication complexity (cf. Shi and Zhang 2010) and property testing (cf. Bhrushundi, Chakraborty, and Kulkarni 2013). In this paper, we investigate the power of parity queries. In particular, we show that the parity queries can be replaced by ordinary ones at the cost of the total influence aka average sensitivity per query. Our simulation is tight as demonstrated by the parity function. At the heart of our result lies a qualitative extension of the result of O’Donnell, Saks, Schramme, and Servedio (2005) titled: Every decision tree has an influential variable. Recently Jain and Zhang (2011) obtained an alternate proof of the same. Our main contribution in this paper is a simple but surprising observation that the query elimination method of Jain and Zhang can indeed be adapted to eliminate, seemingly much more powerful, parity queries. Moreover, we extend our result to linear queries for Boolean valued functions over arbitrary finite fields.
Malik, MI, Ahmed, S, Marcelli, A, Pal, U, Blumenstein, M, Alewijns, L & Liwicki, M 1970, 'ICDAR2015 competition on signature verification and writer identification for on- and off-line skilled forgeries (SigWIcomp2015)', 2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015 13th International Conference on Document Analysis and Recognition (ICDAR), IEEE, Tunis, Tunisia, pp. 1186-1190.
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© 2015 IEEE. This paper presents the results of the ICDAR 2015 competition on signature verification and writer identification for on- and off-line skilled forgeries jointly organized by PR-researchers and Forensic Handwriting Examiners (FHEs). The aim is to bridge the gap between recent technological developments and forensic casework. Two modalities (signatures and handwritten text) are considered and training and evaluation data are collected and provided by FHEs and PR-researchers. Four tasks are defined for four different languages; Bengali off-line signature verification, Italian off-line signature verification, German on-line signature verification, and English handwritten text based writer identification. In total, 40 systems have participated in this competition. The participants of the signatures modality were motivated to report their results in Likelihood Ratios (LRs). This has made the systems even more interesting for application in forensic casework. For evaluating the performance of the systems, we have used the forensically substantial Cost of Log Likelihood Ratios (ɤllr) in the case of signatures, and the F-measure in the case of handwritten text.
Mandal, R, Roy, PP, Palz, U & Blumenstein, M 1970, 'Date field extraction from handwritten documents using HMMs', 2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015 13th International Conference on Document Analysis and Recognition (ICDAR), IEEE, Nancy, France, pp. 866-870.
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© 2015 IEEE. Automatic document interpretation and retrieval is an important task to access handwritten digitized document repositories. In documents, the date is an important field and it has various applications such as date-wise document indexing/retrieval. In this paper a framework has been proposed for automatic date field extraction from handwritten documents. In order to design the system, sliding window-wise Local Gradient Histogram (LGH)-based features and a character-level Hidden Markov Model (HMM)-based approach have been applied for segmentation and recognition. Individual date components such as month-word (month written in word form i.e. January, Jan, etc.), numeral, punctuation and contraction categories are segmented and labelled from a text line. Next, a Histogram of Gradient (HoG)-based features and a Support Vector Machine (SVM)- based classifier have been used to improve the results obtained from the HMM-based recognition system. Subsequently, both numeric and semi-numeric regular expressions of date patterns have been considered for undertaking date pattern extraction in labelled components. The experiments are performed on an English document dataset and the encouraging results obtained from the approach indicate the effectiveness of the proposed system.
Pal, S, Alaei, A, Pal, U & Blumenstein, M 1970, 'Interval-valued symbolic representation based method for off-line signature verification', 2015 International Joint Conference on Neural Networks (IJCNN), 2015 International Joint Conference on Neural Networks (IJCNN), IEEE, Killarney, Ireland.
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© 2015 IEEE. The objective of this investigation is to present an interval-symbolic representation based method for offline signature verification. In the feature extraction stage, Connected Components (CC), Enclosed Regions (ER), Basic Features (BF) and Curvelet Feature (CF)-based approaches are used to characterize signatures. Considering the extracted feature vectors, an interval data value is created for each feature extracted from every individual's signatures as an interval-valued symbolic data. This process results in a signature model for each individual that consists of a set of interval values. A similarity measure is proposed as the classifier in this paper. The interval-valued symbolic representation based method has never been used for signature verification considering Indian script signatures. Therefore, to evaluate the proposed method, a Hindi signature database consisting of 2400 (100×24) genuine signatures and 3000 (100×30) skilled forgeries is employed for experimentation. Concerning this large Hindi signature dataset, the highest verification accuracy of 91.83% was obtained on a joint feature set considering all four sets of features, while 2.5%, 13.84% and 8.17% of FAR (False Acceptance Rate), FRR (False Rejection Rate), and AER (Average Error Rate) were achieved, respectively.
Paler, A & Devitt, SJ 1970, 'An introduction to Fault-tolerant Quantum Computing', DAC'15 Proceedings of the 52nd Annual Design Automation Conference Article No. 60 (2015).
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In this paper we provide a basic introduction of the core ideas and theoriessurrounding fault-tolerant quantum computation. These concepts underly thetheoretical framework of large-scale quantum computation and communications andare the driving force for many recent experimental efforts to construct smallto medium sized arrays of controllable quantum bits. We examine the basicprincipals of redundant quantum encoding, required to protect quantum bits fromerrors generated from both imprecise control and environmental interactions andthen examine the principals of fault-tolerance from largely a classicalframework. As quantum fault-tolerance essentially is avoiding theuncontrollable cascade of errors caused by the interaction of quantum-bits,these concepts can be directly mapped to quantum information.
Paler, A, Polian, I, Nemoto, K & Devitt, SJ 1970, 'A Regular Representation of Quantum Circuits', Bernard, pp. 139-154.
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We present a quantum circuit representation consisting entirely of qubitinitialisations (I), a network of controlled-NOT gates (C) and measurementswith respect to different bases (M). The ICM representation is useful foroptimisation of quantum circuits that include teleportation, which is requiredfor fault-tolerant, error corrected quantum computation. The non-deterministicnature of teleportation necessitates the conditional introduction of correctivequantum gates and additional ancillae during circuit execution. Therefore, thestandard optimisation objectives, gate count and number of wires, are notwell-defined for general teleportation-based circuits. The transformation of acircuit into the ICM representation provides a canonical form for an exactfault-tolerant, error corrected circuit needed for optimisation prior to thefinal implementation in a realistic hardware model.
Sharma, N, Mandal, R, Sharma, R, Pal, U & Blumenstein, M 1970, 'Bag-of-Visual Words for word-wise video script identification: A study', 2015 International Joint Conference on Neural Networks (IJCNN), 2015 International Joint Conference on Neural Networks (IJCNN), IEEE, Killarney, Ireland.
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© 2015 IEEE. Use of multiple scripts for information communication through various media is quite common in a multilingual country. Optical character recognition of such document images or videos assists in indexing them for effective information retrieval. Hence, script identification from multi-lingual documents/images is a necessary step for selecting the appropriate OCR, due the absence of a single OCR system capable of handling multiple scripts. Script identification from printed as well as handwritten documents is a well-researched area, but script identification from video frames has not been explored much. Low resolution, blur, noisy background, to mention a few are the major bottle necks when processing video frames, and makes script identification from video images a challenging task. This paper examines the potential of Bag-of-Visual Words based techniques for word-wise script identification from video frames. Two different approaches namely, Bag-Of-Features (BoF) and Spatial Pyramid Matching (SPM), using patch based SIFT descriptors were considered for the current study. SVM Classifier was used for analysing the three popular south Indian scripts, namely Tamil, Telugu and Kannada in combination with English and Hindi. A comparative study of Bag-of-Visual words with traditional script identification techniques involving gradient based features (e.g. HoG) and texture based features (e.g. LBP) is presented. Experimental results shows that patch-based features along with SPM outperformed the traditional techniques and promising accuracies were achieved on 2534 words from the five scripts. The study reveals that patch-based feature can be used for scripts identification in-order to overcome the inherent problems with video frames.
Sharma, N, Mandal, R, Sharma, R, Pal, U & Blumenstein, M 1970, 'ICDAR2015 Competition on Video Script Identification (CVSI 2015)', 2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015 13th International Conference on Document Analysis and Recognition (ICDAR), IEEE, pp. 1196-1200.
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© 2015 IEEE. This paper presents the final results of the ICDAR 2015 Competition on Video Script Identification. A description and performance of the participating systems in the competition are reported. The general objective of the competition is to evaluate and benchmark the available methods on word-wise video script identification. It also provides a platform for researchers around the globe to particularly address the video script identification problem and video text recognition in general. The competition was organised around four different tasks involving various combinations of scripts comprising tri-script and multi-script scenarios. The dataset used in the competition comprised ten different scripts. In total, six systems were received from five participants over the tasks offered. This report details the competition dataset specifications, evaluation criteria, summary of the participating systems and their performance across different tasks. The systems submitted by Google Inc. were the winner of the competition for all the tasks, whereas the systems received from Huazhong University of Science and Technology (HUST) and Computer Vision Center (CVC) were very close competitors.
Sharma, N, Mandal, R, Sharma, R, Roy, PP, Pal, U & Blumenstein, M 1970, 'Multi-lingual text recognition from video frames', 2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015 13th International Conference on Document Analysis and Recognition (ICDAR), IEEE, Nancy, France, pp. 951-955.
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© 2015 IEEE. Text recognition from video frames is a challenging task due to low resolution, blur, complex and coloured backgrounds, noise, to mention a few. Consequently, the traditional ways of text recognition from scanned documents having simple backgrounds fails when applied to video text. Although there are various techniques available for text recognition from handwritten and printed documents with simple backgrounds, text recognition from video frames has not been comprehensively investigated, especially for multi-lingual videos. In this paper, we present a technique for multi-lingual video text recognition which involves script identification in the first stage, followed by word and character recognition, and finally the results are refined using a post-processing technique. Considering the inherent problems in videos, a Spatial Pyramid Matching (SPM) based technique, using patch-based SIFT descriptors and SVM classifier, is employed for script identification. In the next stage, a Hidden Markov Model (HMM) based approach is used for word and character recognition, which utilizes the context information. Finally, a lexicon-based post-processing technique is applied to verify and refine the word recognition results. The proposed method was tested on a dataset comprising of 4800 words from three different scripts, namely, Roman (English), Hindi and Bengali. The script identification results obtained are encouraging. The word and character recognition results are also encouraging considering the complexity and problems associated with video text processing.
Suwanwiwat, H, Blumenstein, M & Pal, U 1970, 'A complete automatic short answer assessment system with student identification', 2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015 13th International Conference on Document Analysis and Recognition (ICDAR), IEEE, Nancy, France, pp. 611-615.
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© 2015 IEEE. There are only a few studies undertaken in developing automatic assessment systems using handwriting recognition, even though a successful system would undoubtedly benefit the education system as schools and universities in many countries still employ paper-based examinations. To the best of the authors' knowledge, there is no existing work on an automatic off-line short answer assessment system comprising a student identification component. Hence in this paper, the authors propose a system towards this, where a new feature extraction technique called the Enhanced Water Reservoir, Loop and Gaussian Grid Feature, as well as other enhanced feature extraction techniques were utilised. Artificial Neural Networks and Support Vector Machines were employed as the classifiers; they were used for the investigation, and a comparison of the recognition and accuracy rates of the proposed systems, as well as the feature extraction techniques, was undertaken. The proposed assessment system achieved a recognition rate of 87.12% with 91.12% assessment accuracy, and the student identification component obtained a recognition rate of 99.52% with a 100% identification accuracy rate.
Suwanwiwat, H, Blumenstein, M & Pal, U 1970, 'Short answer question examination using an automatic off-line handwriting recognition system and a novel combined feature', 2015 International Joint Conference on Neural Networks (IJCNN), 2015 International Joint Conference on Neural Networks (IJCNN), IEEE, Killarney, Ireland.
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© 2015 IEEE. Off-line automatic assessment systems can be an aid for teachers in the marking process. There has been no recent work in the development of off-line automatic assessment systems using handwriting recognition, even though such systems will clearly benefit the education sector. The reason is many schools and universities in many parts of the world still use paper-based examination. This research proposes the use of a newly developed feature extraction technique called the Modified Water Reservoir, Loop and Gaussian Grid Feature, as well as other feature extraction techniques. These techniques were investigated employing artificial neural networks and support vector machines as classifiers to develop an automatic assessment system for marking short answer questions. The system has high assessment accuracy (up to 94.75% for hand printed, 96.09% for cursive handwritten, and 95.71% for hand printed and cursive handwritten combined). The proposed system also includes assessment criteria to augment its accuracy.
Tomamichel, M, Wilde, MM & Winter, A 1970, 'Strong converse rates for quantum communication', 2015 IEEE International Symposium on Information Theory (ISIT), 2015 IEEE International Symposium on Information Theory (ISIT), IEEE, Hong Kong, China, pp. 2386-2390.
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© 2015 IEEE. We revisit a fundamental open problem in quantum information theory, namely whether it is possible to transmit quantum information at a rate exceeding the channel capacity if we allow for a non-vanishing probability of decoding error. Here we establish that the Rains information of any quantum channel is a strong converse rate for quantum communication: For any code with a rate exceeding the Rains information of the channel, we show that the fidelity vanishes exponentially fast as the number of channel uses increases. This remains true even if we consider codes that perform classical post-processing on the transmitted quantum data. Our result has several applications. Most importantly, for generalized dephasing channels we show that the Rains information is also achievable, and thereby establish the strong converse property for quantum communication over such channels. This for the first time conclusively settles the strong converse question for a class of quantum channels that have a non-trivial quantum capacity.
Xu, J, Shivakumara, P, Lu, T, Tan, CL & Blumenstein, M 1970, 'Text detection in born-digital images by mass estimation', 2015 3rd IAPR Asian Conference on Pattern Recognition (ACPR), 2015 3rd IAPR Asian Conference on Pattern Recognition (ACPR), IEEE, Kuala Lumpur, Malaysia, pp. 690-694.
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© 2015 IEEE.There is a need for effective web-document understanding due to the explosive progress of internet and network technologies. In this paper, we propose a new method for text detection in born-digital images by introducing a mass estimation concept. We propose to explore super-pixel information of different color channels to identify text atoms in images. The proposed method uses similarity graphs and spectral clustering to identify candidate text regions. We propose a new idea of mapping Gabor responses of a candidate text region to a spatial circle to study the spatial coherency of pixels. We introduce a mass estimation concept to identify text candidates from the pixel distribution in a spatial circle. The linear linkage graphs help in grouping text candidates to obtain full text lines. The same Gabor responses are used as features to eliminate false positives with an SVM classifier. We evaluate the proposed method for the testing on standard datasets, such as ICDAR 2013 (challenge-1) and the Situ et al. dataset. Experimental results on both the datasets show that the proposed method outperforms the existing methods.
