Searching Arxiv, refresh for possibly better results.

Results for "Neereja Sundaresan"

total 95took 0.12s
Observation of a dissipative phase transition in a one-dimensional circuit QED latticeJul 23 2016Condensed matter physics has been driven forward by significant experimental and theoretical progress in the study and understanding of equilibrium phase transitions based on symmetry and topology. However, nonequilibrium phase transitions have remained ... More
Time-Reversal Symmetrization of Spontaneous Emission for High Fidelity Quantum State TransferAug 15 2013We demonstrate the ability to control the spontaneous emission from a superconducting qubit coupled to a cavity. The time domain profile of the emitted photon is shaped into a symmetric truncated exponential. The experiment is enabled by a qubit coupled ... More
Verifying Multipartite Entangled GHZ States via Multiple Quantum CoherencesMay 14 2019The ability to generate and verify multipartite entanglement is an important benchmark for near-term quantum devices devices. We develop a scalable entanglement metric based on multiple quantum coherences, and demonstrate experimentally on a 20-qubit ... More
Guessing based on length functionsFeb 20 2007Apr 15 2007A guessing wiretapper's performance on a Shannon cipher system is analyzed for a source with memory. Close relationships between guessing functions and length functions are first established. Subsequently, asymptotically optimal encryption and attack ... More
Guessing under source uncertaintyMar 16 2006Sep 08 2006This paper considers the problem of guessing the realization of a finite alphabet source when some side information is provided. The only knowledge the guesser has about the source and the correlated side information is that the joint source is one among ... More
Interacting Qubit-Photon Bound States with Superconducting CircuitsJan 30 2018Qubits strongly coupled to a photonic crystal give rise to many exotic physical scenarios, beginning with single and multi-excitation qubit-photon dressed bound states comprising induced spatially localized photonic modes, centered around the qubits, ... More
Filtered models for reacting gas-particle flowsApr 26 2012Using the kinetic-theory-based two-fluid models as a starting point, we develop filtered two-fluid models for a gas-particle flow in the presence of an isothermal, first-order, solid-catalyzed reaction of a gaseous species. As a consequence of the filtering ... More
Belief propagation for optimal edge cover in the random complete graphDec 25 2012Sep 05 2014We apply the objective method of Aldous to the problem of finding the minimum-cost edge cover of the complete graph with random independent and identically distributed edge costs. The limit, as the number of vertices goes to infinity, of the expected ... More
The Size of Optimal Sequence Sets for Synchronous CDMA SystemsJun 03 2006Feb 27 2008The sum capacity on a symbol-synchronous CDMA system having processing gain $N$ and supporting $K$ power constrained users is achieved by employing at most $2N-1$ sequences. Analogously, the minimum received power (energy-per-chip) on the symbol-synchronous ... More
Radial hopper flow prediction using a constitutive model with microstructure evolutionJul 07 2012We present theoretical predictions of granular flow in a conical hopper based on a continuum theory employing a recently-developed constitutive model with microstructure evolution by Sun and Sundaresan [1]. The model is developed for strain rate-independent ... More
Decentralized sequential change detection using physical layer fusionJul 22 2007Aug 04 2008The problem of decentralized sequential detection with conditionally independent observations is studied. The sensors form a star topology with a central node called fusion center as the hub. The sensors make noisy observations of a parameter that changes ... More
Separable convex optimization problems with linear ascending constraintsJul 16 2007Separable convex optimization problems with linear ascending inequality and equality constraints are addressed in this paper. Under an ordering condition on the slopes of the functions at the origin, an algorithm that determines the optimum point in a ... More
Beyond Strong Coupling in a Massively Multimode CavityFeb 09 2015Feb 13 2015The study of light-matter interaction has seen a resurgence in recent years, stimulated by highly controllable, precise, and modular experiments in cavity quantum electrodynamics (QED). The achievement of strong coupling, where the coupling between a ... More
Guessing Revisited: A Large Deviations ApproachAug 11 2010The problem of guessing a random string is revisited. A close relation between guessing and compression is first established. Then it is shown that if the sequence of distributions of the information spectrum satisfies the large deviation property with ... More
Double-Auction Mechanisms for Resource Trading MarketJan 27 2019We consider a double-auction mechanism, which was recently proposed in the context of a mobile data-offloading market. It is also applicable in a network slicing market. Network operators (users) derive benefit from offloading their traffic to third party ... More
Minimization Problems Based on Relative $α$-Entropy II: Reverse ProjectionOct 21 2014Jun 10 2015In part I of this two-part work, certain minimization problems based on a parametric family of relative entropies (denoted $\mathscr{I}_{\alpha}$) were studied. Such minimizers were called forward $\mathscr{I}_{\alpha}$-projections. Here, a complementary ... More
Stochastic Approximation Algorithm for Optimal Throughput Performance of Wireless LANsJun 10 2010Throughput improvement of the Wireless LANs has been a constant area of research. Most of the work in this area, focuses on designing throughput optimal schemes for fully connected networks (no hidden nodes). But, we demonstrate that the proposed schemes, ... More
Active Search with a Cost for Switching ActionsMay 10 2015Active Sequential Hypothesis Testing (ASHT) is an extension of the classical sequential hypothesis testing problem with controls. Chernoff (Ann. Math. Statist., 1959) proposed a policy called Procedure A and showed its asymptotic optimality as the cost ... More
Further Results on Geometric Properties of a Family of Relative EntropiesFeb 24 2011May 28 2011This paper extends some geometric properties of a one-parameter family of relative entropies. These arise as redundancies when cumulants of compressed lengths are considered instead of expected compressed lengths. These parametric relative entropies are ... More
Relative $α$-Entropy Minimizers Subject to Linear Statistical ConstraintsOct 18 2014We study minimization of a parametric family of relative entropies, termed relative $\alpha$-entropies (denoted $\mathscr{I}_{\alpha}(P,Q)$). These arise as redundancies under mismatched compression when cumulants of compressed lengths are considered ... More
Minimization Problems Based on Relative $α$-Entropy I: Forward ProjectionOct 09 2014Jun 10 2015Minimization problems with respect to a one-parameter family of generalized relative entropies are studied. These relative entropies, which we term relative $\alpha$-entropies (denoted $\mathscr{I}_{\alpha}$), arise as redundancies under mismatched compression ... More
Reputation-Based Information Design for Inducing Prosocial BehaviorMay 02 2019We study the idea of information design for inducing prosocial behavior in the context of electricity consumption. We consider a continuum of agents. Each agent has a different intrinsic motivation to reduce her power consumption. Each agent models the ... More
Asymptotics of the Invariant Measure in Mean Field Models with JumpsJul 21 2011Jan 23 2013We consider the asymptotics of the invariant measure for the process of the empirical spatial distribution of $N$ coupled Markov chains in the limit of a large number of chains. Each chain reflects the stochastic evolution of one particle. The chains ... More
Learning to detect an oddball targetAug 23 2015Sep 23 2015We consider the problem of detecting an odd process among a group of Poisson point processes, all having the same rate except the odd process. The actual rates of the odd and non-odd processes are unknown to the decision maker. We consider a time-slotted ... More
Learning to Detect an Odd Markov ArmApr 25 2019A multi-armed bandit with finitely many arms is studied when each arm is a homogeneous Markov process on an underlying finite state space. The transition law of one of the arms, referred to as the odd arm, is different from the common transition law of ... More
Learning to Detect an Odd Markov ArmApr 25 2019Apr 27 2019A multi-armed bandit with finitely many arms is studied when each arm is a homogeneous Markov process on an underlying finite state space. The transition law of one of the arms, referred to as the odd arm, is different from the common transition law of ... More
An Iterative Interior Point Network Utility Maximization AlgorithmSep 11 2016Distributed and iterative network utility maximization algorithms, such as the primal-dual algorithms or the network-user decomposition algorithms, often involve trajectories where the iterates may be infeasible. In this paper, we propose a distributed ... More
Learning to Detect an Odd Markov ArmApr 25 2019May 01 2019A multi-armed bandit with finitely many arms is studied when each arm is a homogeneous Markov process on an underlying finite state space. The transition law of one of the arms, referred to as the odd arm, is different from the common transition law of ... More
Bridging the rheology of granular flows in three regimesJan 27 2012We investigate the rheology of granular materials via molecular dynamics simulations of homogeneous, simple shear flows of soft, frictional, noncohesive spheres. In agreement with previous results for frictionless particles, we observe three flow regimes ... More
The Shannon Cipher System with a Guessing Wiretapper: General SourcesAug 11 2010The Shannon cipher system is studied in the context of general sources using a notion of computational secrecy introduced by Merhav & Arikan. Bounds are derived on limiting exponents of guessing moments for general sources. The bounds are shown to be ... More
A Survey of Algorithms for Separable Convex Optimization with Linear Ascending ConstraintsAug 29 2016The paper considers the minimization of a separable convex function subject to linear ascending constraints. The problem arises as the core optimization in several resource allocation scenarios, and is a special case of an optimization of a separable ... More
Influence of Internal Fields on the Electronic Structure in Self-Assembled InAs/GaAs Quantum DotsMay 22 2010Built-in electrostatic fields in Zincblende quantum dots originate mainly from - (1) the fundamental crystal atomicity and the interfaces between two dissimilar materials, (2) the strain relaxation, and (3) the piezoelectric polarization. In this paper, ... More
A non-linear dynamical systems approach to source compression for constrained sourcesSep 11 2007We have recently established a strong connection between the Tent map (also known as Generalized Luroth Series or GLS which is a chaotic, ergodic and lebesgue measure preserving non-linear dynamical system) and Arithmetic coding which is a popular source ... More
Optimal Mechanisms for Selling Two Items to a Single Buyer Having Uniformly Distributed ValuationsOct 21 2016We consider the design of an optimal mechanism for a seller selling two items to a single buyer so that the expected revenue to the seller is maximized. The buyer's valuation of the two items is assumed to be the uniform distribution over an arbitrary ... More
A Mean-field Approach for Controlling Singularly Perturbed Multi-population SIS EpidemicsFeb 15 2019We consider a multi-population epidemic model with one or more (almost) isolated communities and one mobile community. Each of the isolated communities has contact within itself and, in addition, contact with the outside world but only through the mobile ... More
Asynchronous Gossip for Averaging and Spectral RankingSep 30 2013Jan 06 2014We consider two variants of the classical gossip algorithm. The first variant is a version of asynchronous stochastic approximation. We highlight a fundamental difficulty associated with the classical asynchronous gossip scheme, viz., that it may not ... More
Implications and consequences of ferromagnetism universally exhibited by inorganic nanoparticlesMay 02 2009Occurrence of surface ferromagnetism in inorganic nanoprticles as a universal property not only explains many of the unusual magnetic features of oxidic thin films, but also suggests its possible use in creating new materials, as exemplified by multiferroic ... More
Combined Base Station Association and Power Control in Multi-channel Cellular NetworksDec 08 2011A combined base station association and power control problem is studied for the uplink of multichannel multicell cellular networks, in which each channel is used by exactly one cell (i.e., base station). A distributed association and power update algorithm ... More
Regulation of off-network pricing in a nonneutral networkApr 20 2012Sep 30 2013Representatives of several Internet service providers (ISPs) have expressed their wish to see a substantial change in the pricing policies of the Internet. In particular, they would like to see content providers (CPs) pay for use of the network, given ... More
Neural dissimilarity indices that predict oddball detection in behaviourMay 10 2015Neuroscientists have recently shown that images that are difficult to find in visual search elicit similar patterns of firing across a population of recorded neurons. The $L^{1}$ distance between firing rate vectors associated with two images was strongly ... More
Valence instability of cerium under pressure in the Kondo-like perovskite La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$Jul 05 2005Effect of hydrostatic pressure and magnetic field on electrical resistance of the Kondo-like perovskite manganese oxide, La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$ with a ferrimagnetic ground state, have been investigated up to 2.1 GPa and 9 T. In this compound, ... More
Simple test for high Jc and low Rs superconducting thin filmsFeb 13 2003A simple method, fishing high-Tc superconductor thin films out of liquid nitrogen bath by a permanent magnet (field > Hc1) due to the effect of high flux pinning, has been suggested to identify films having high critical current density (Jc > 106 A/cm2 ... More
Spying on the Smart Home: Privacy Attacks and Defenses on Encrypted IoT TrafficAug 16 2017The growing market for smart home IoT devices promises new conveniences for consumers while presenting new challenges for preserving privacy within the home. Many smart home devices have always-on sensors that capture users' offline activities in their ... More
Room-temperature ferromagnetism in nanoparticles of superconducting materialsJun 05 2007Nanoparticles of superconducting YBa2Cu3O7-delta (YBCO) (Tc = 91 K) exhibit ferromagnetism at room temperature while the bulk YBCO, obtained by heating the nanoparticles at high temperature (940 degree C), shows a linear magnetization curve. Across the ... More
The Economics of Quality Sponsored Data in Non-Neutral NetworksJan 12 2015Oct 17 2016The growing demand for data has driven the Service Providers (SPs) to provide differential treatment of traffic to generate additional revenue streams from Content Providers (CPs). While SPs currently only provide best-effort services to their CPs, it ... More
Model-Based Cross-Correlation Search for Gravitational Waves from Scorpius X-1Apr 22 2015May 20 2015We consider the cross-correlation search for periodic GWs and its potential application to the LMXB Sco X-1. This method coherently combines data from different detectors at the same time, as well as different times from the same or different detectors. ... More
On the Feasibility of Decentralized Derivatives MarketsFeb 14 2018In this paper, we present Velocity, a decentralized market deployed on Ethereum for trading a custom type of derivative option. To enable the smart contract to work, we also implement a price fetching tool called PriceGeth. We present this as a case study, ... More
Particle simulation of vibrated gas-fluidized beds of cohesive fine powdersOct 05 2005Aug 09 2006We use three-dimensional particle dynamics simulations, coupled with volume-averaged gas phase hydrodynamics, to study vertically vibrated gas-fluidized beds of fine, cohesive powders. The volume-averaged interstitial gas flow is restricted to be one-dimensional ... More
Investigation of biferroic properties in La0.6Sr0.4MnO3/0.7 Pb(Mg1/3Nb2/3)O3 0.3 PbTiO3 epitaxial bilayered heterostructuresJun 25 2009Epitaxial bilayered thin films consisting of La0.6Sr0.4MnO3 (LSMO) and 0.7 Pb(Mg1/3Nb2/3)O3 0.3 PbTiO3 (PMN-PT) layers of relatively different thicknesses were fabricated on LaNiO3 coated LaAlO3 (100) single crystal substrates by pulsed laser ablation ... More
Compact Scene Graphs for Layout Composition and Patch RetrievalApr 19 2019Structured representations such as scene graphs serve as an efficient and compact representation that can be used for downstream rendering or retrieval tasks. However, existing efforts to generate realistic images from scene graphs perform poorly on scene ... More
Optimal Forwarding in Delay Tolerant Networks with Multiple DestinationsOct 27 2011We study the trade-off between delivery delay and energy consumption in a delay tolerant network in which a message (or a file) has to be delivered to each of several destinations by epidemic relaying. In addition to the destinations, there are several ... More
An asymptotically optimal push-pull method for multicasting over a random networkOct 11 2012Feb 08 2013We consider allcast and multicast flow problems where either all of the nodes or only a subset of the nodes may be in session. Traffic from each node in the session has to be sent to every other node in the session. If the session does not consist of ... More
Subgraph Detection with cues using Belief PropagationNov 10 2016Nov 23 2016We consider an Erdos-Renyi graph with $n$ nodes and edge probability $q$ that is embedded with a random subgraph of size $K$ with edge probabilities $p$ such that $p\textgreater{}q.$ We address the problem of detecting the subgraph nodes when only the ... More
Multiferroic nature of charge-ordered rare earth manganitesAug 06 2007Charge-ordered rare earth manganites Nd0.5Ca0.5MnO3, La0.25Nd0.25Ca0.5MnO3, Pr0.7Ca0.3MnO3 and Pr0.6Ca0.4MnO3 are found to exhibit dielectric constant anomalies around the charge-ordering or the magnetic transition temperatures. Magnetic fields have a ... More
Large magnetoelectric effect in the Al1-xGaxFeO3 family of multiferroic OxidesAug 27 2010AlFeO3, GaFeO3 and Al0.5Ga0.5FeO3, all crystallizing in a non-centrosymmetric space group, are multiferroic and also exhibit magnetoelectric properties, with Al0.5Ga0.5FeO3 showing unusually large magnetocapacitance at 300 K.
Fast Approximate Matching of Cell-Phone Videos for Robust Background SubtractionApr 22 2014We identify a novel instance of the background subtraction problem that focuses on extracting near-field foreground objects captured using handheld cameras. Given two user-generated videos of a scene, one with and the other without the foreground object(s), ... More
Coarse-grained computations of demixing in dense gas-fluidized bedsNov 06 2006We use an "equation-free", coarse-grained computational approach to accelerate molecular dynamics-based computations of demixing (segregation) of dissimilar particles subject to an upward gas flow (gas-fluidized beds). We explore the coarse-grained dynamics ... More
SkyLiTE: End-to-End Design of Low-Altitude UAV Networks for Providing LTE ConnectivityFeb 16 2018Feb 20 2018Un-manned aerial vehicle (UAVs) have the potential to change the landscape of wide-area wireless connectivity by bringing them to areas where connectivity was sparing or non-existent (e.g. rural areas) or has been compromised due to disasters. While Google's ... More
The Economics of Quality Sponsored Data in Non-Neutral NetworksJan 12 2015Apr 29 2016The growing demand for data has driven the Service Providers (SPs) to provide differential treatment of traffic to generate additional revenue streams from Content Providers (CPs). While SPs currently only provide best-effort services to their CPs, it ... More
Subgraph Detection with cues using Belief PropagationNov 10 2016We consider an Erdos-Renyi graph with $n$ nodes and edge probability $q$ that is embedded with a random subgraph of size $K$ with edge probabilities $p$ such that $p>q$. We address the problem of detecting the subgraph nodes when only the graph edges ... More
Almost Budget Balanced Mechanisms with Scalar Bids For Allocation of a Divisible GoodOct 21 2016This paper is about allocation of an infinitely divisible good to several rational and strategic agents. The allocation is done by a social planner who has limited information because the agents' valuation functions are taken to be private information ... More
Compaction and dilation rate dependence of stresses in gas-fluidized bedsFeb 06 2006Aug 09 2006A particle dynamics-based hybrid model, consisting of monodisperse spherical solid particles and volume-averaged gas hydrodynamics, is used to study traveling planar waves (one-dimensional traveling waves) of voids formed in gas-fluidized beds of narrow ... More
Magnetocapacitive La0.6Sr0.4MnO3 0.7Pb(Mg0.33Nb0.67)O3 0.3PbTiO3 epitaxial heterostructuresFeb 15 2008Apr 16 2008Epitaxial heterostructures of La0.6Sr0.4MnO3 0.7Pb(Mg0.33Nb0.67)O3 0.3PbTiO3 were fabricated on LaNiO3 coated LaAlO3 (100) substrates by pulsed laser ablation. Ferromagnetic and ferroelectric hysteresis established their biferroic nature. Dielectric behviour ... More
A QoS aware Novel Probabilistic strategy for Dynamic Resource AllocationMar 24 2015The paper proposes a two player game based strategy for resource allocation in service computing domain such as cloud, grid etc. The players are modeled as demand/workflows for the resource and represent multiple types of qualitative and quantitative ... More
Coarse Bifurcation Studies of Bubble Flow Microscopic SimulationsNov 16 2001The parametric behavior of regular periodic arrays of rising bubbles is investigated with the aid of 2-dimensional BGK Lattice-Boltzmann (LB) simulators. The Recursive Projection Method is implemented and coupled to the LB simulators, accelerating their ... More
The Power of Side-information in Subgraph DetectionNov 10 2016Mar 06 2017In this work, we tackle the problem of hidden community detection. We consider Belief Propagation (BP) applied to the problem of detecting a hidden Erd\H{o}s-R\'enyi (ER) graph embedded in a larger and sparser ER graph, in the presence of side-information. ... More
Weak ferromagnetism and magnetization reversal in YFe$_{1-x}$Cr$_x$O$_3$Oct 26 2015We present combined experimental and theoretical studies on the magnetic properties of a solid solution between yttrium orthoferrite and yttrium orthochromite systems, YFe$_{1-x}$Cr$_x$O$_3$ (0 $\leq$ x $\leq$ 1) where Fe$^{3+}$ and Cr$^{3+}$ ions are ... More
Large Scale Visual Recommendations From Street Fashion ImagesJan 08 2014We describe a completely automated large scale visual recommendation system for fashion. Our focus is to efficiently harness the availability of large quantities of online fashion images and their rich meta-data. Specifically, we propose four data driven ... More
Spatial SINR Games of Base Station Placement and Mobile AssociationFeb 17 2011We study the question of determining locations of base stations that may belong to the same or to competing service providers. We take into account the impact of these decisions on the behavior of intelligent mobile terminals who can connect to the base ... More
Haystack: A Multi-Purpose Mobile Vantage Point in User SpaceOct 06 2015May 17 2016Despite our growing reliance on mobile phones for a wide range of daily tasks, their operation remains largely opaque. A number of previous studies have addressed elements of this problem in a partial fashion, trading off analytic comprehensiveness and ... More
Interplay of 4f-3d Magnetism and Ferroelectricity in DyFeO3Jan 15 2013DyFeO3 exhibits a weak ferromagnetism (TNFe ~ 645 K) that disappears below a spin-reorientation (Morin) transition at TSRFe ~ 50 K. It is also known that applied magnetic field induces ferroelectricity at the magnetic ordering temperature of Dy-ions (TNDy ... More
Tracking the Trackers: Towards Understanding the Mobile Advertising and Tracking EcosystemSep 22 2016Oct 26 2016Third-party services form an integral part of the mobile ecosystem: they allow app developers to add features such as performance analytics and social network integration, and to monetize their apps by enabling user tracking and targeted ad delivery. ... More
Neighbor Oblivious and Finite-State Algorithms for Circumventing Local Minima in Geographic ForwardingMar 01 2011May 04 2012We propose distributed link reversal algorithms to circumvent communication voids in geographic routing. We also solve the attendant problem of integer overflow in these algorithms. These are achieved in two steps. First, we derive partial and full link ... More
Simultaneous Small Noise Limit for Singularly Perturbed Slow-Fast Coupled DiffusionsOct 08 2018Oct 16 2018We consider a simultaneous small noise limit for a singularly perturbed coupled diffusion described by \begin{eqnarray*} dX^{\varepsilon}_t &=& b(X^{\varepsilon}_t, Y^{\varepsilon}_t)dt + \varepsilon^{\alpha}dB_t, dY^{\varepsilon}_t &=& - \frac{1}{\varepsilon} ... More
Field-induced Polar Order at the Néel Temperature of Chromium in Rare-earth Orthochromites: Interplay of Rare-earth and Cr MagnetismDec 12 2012We report field-induced switchable polarization (P = 0.2 ~ 0.8 microC/cm2) below the N\'eel temperature of chromium (TN Cr) in weakly ferromagnetic rareearth orthochromites, RCrO3 (R=rareearth) but only when the rareearth ion is magnetic. Intriguingly, ... More
A Multi-Modal Approach to Infer Image AffectMar 13 2018The group affect or emotion in an image of people can be inferred by extracting features about both the people in the picture and the overall makeup of the scene. The state-of-the-art on this problem investigates a combination of facial features, scene ... More
Ferroelectricity at the Néel Temperature of Chromium in Rare-earth Orthochromites: Interplay of Rare-earth and Cr MagnetismJan 04 2012Dec 18 2012We report ferroelectricity with fairly large spontaneous polarization (P ~ 0.2 - 0.8 \muC/cm2) below the N\'eel temperature of chromium (TNCr) in weakly ferromagnetic rare-earth orthochromites, RCrO3 (R=rare-earth) only when the rare-earth ion is magnetic. ... More
Effect of pressure on octahedral distortions in RCrO3 (R = Lu, Tb, Gd, Eu, Sm): The role of R-ion size and its implicationsDec 24 2013Jun 05 2014The effect of rare-earth ion size on the octahedral distortions in rare-earth chromites (RCrO3, R = Lu, Tb, Gd, Eu, Sm) crystallizing in the orthorhombic structure has been studied using Raman scattering and synchrotron powder x-ray diffraction up to ... More
Multiferroic and magnetoelectric nature of GaFeO3, AlFeO3 and related oxidesDec 26 2011Aug 12 2012GaFeO3, AlFeO3 and related oxides are ferrimagnetic exhibiting magnetodielectric effect. There has been no evidence to date for ferroelectricity and hence multiferroicity in these oxides. We have investigated these oxides as well as oxides of the composition ... More
119Sn NMR probe of magnetic fluctuations in SnO2 nanoparticlesNov 05 2011119Sn nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation rate (1/T1) in SnO2 nanoparticles were measured as a function of temperature and compared with those of SnO2 bulk sample. A 15% loss of 119Sn NMR signal intensity for the nano ... More
Lightweight, General Inference of Streaming Video Quality from Encrypted TrafficJan 17 2019Jan 23 2019Accurately monitoring application performance is becoming more important for Internet Service Providers (ISPs), as users increasingly expect their networks to consistently deliver acceptable application quality. At the same time, the rise of end-to-end ... More
Tracking the Trackers: Towards Understanding the Mobile Advertising and Tracking EcosystemSep 22 2016Third-party services form an integral part of the mobile ecosystem: they allow app developers to add features such as performance analytics and social network integration, and to monetize their apps by enabling user tracking and targeted ad delivery. ... More
Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxidesJul 21 2007Room-temperature ferromagnetism has been observed in the nanoparticles (7 - 30 nm dia) of nonmagnetic oxides such as CeO2, Al2O3, ZnO, In2O3 and SnO2. The saturated magnetic moments in CeO_2 and Al_2O_3 nanoparticles are comparable to those observed in ... More
Multiferroic Properties of Nanocrystalline BaTiO3Sep 10 2008Sep 11 2008Some of the Multiferroics [1] form a rare class of materials that exhibit magnetoelectric coupling arising from the coexistence of ferromagnetism and ferroelectricity, with potential for many technological applications.[2,3] Over the last decade, an active ... More
Structural and magnetic properties of a new and ordered quaternary alloy MnNiCuSb (SG: F-43m)Sep 16 2015We have synthesized a new crystallographically ordered quaternary Heusler alloy, MnNiCuSb. The crystal structure of the alloy has been determined by Rietveld refinement of the powder x-ray diffraction data. This alloy crystallizes in the LiMgPdSb type ... More
Temperature dependent magnetic, dielectric and Raman studies of partially disordered La2NiMnO6Dec 26 2013We report a detailed magnetic, dielectric and Raman studies on partially disordered and biphasic double perovskite La2NiMnO6. DC and AC magnetic susceptibility measurements show two magnetic anomalies at TC1 ~ 270 K and TC2 ~ 240 K, which may indicate ... More
Silo Music and Silo Quake: Granular Flow Induced VibrationOct 04 2003Acceleration and sound measurements during granular discharge from silos are used to show that silo music is a sound resonance produced by silo quake. The latter is produced by stick-slip friction between the wall and the granular material in tall narrow ... More
Haystack: A Multi-Purpose Mobile Vantage Point in User SpaceOct 06 2015Oct 29 2016Despite our growing reliance on mobile phones for a wide range of daily tasks, their operation remains largely opaque. A number of previous studies have addressed elements of this problem in a partial fashion, trading off analytic comprehensiveness and ... More
Interface dominated biferroic La0.6Sr0.4MnO3/0.7Pb(Mg0.33Nb0.66)O3 0.3PbTiO3 epitaxial superlatticesDec 27 2006Superlattices composed of ferromagnetic La0.6Sr0.4MnO3 and ferroelectric 0.7Pb(Mg0,33Nb0.66)O3 0.3(PbTiO3) layers were fabricated on (100) LaAlO3 substrates by pulsed laser deposition technique. Ferromagnetic and frequency independent ferroelectric hysteresis ... More
Evidence of a cluster spin-glass state in the B-site disordered perovskite SrTi0.5Mn0.5O3Feb 24 2019SrTi0.5Mn0.5O3 (STMO) is a chemically disordered perovskite having random distribution of Ti and Mn over 1b site. Striking discrepancies about the structural and magnetic properties of STMO demands detailed analysis which is addressed. To explore the ... More
Realization of biferroic properties in La0.6Sr0.4MnO3 0.7Pb(Mg0.33Nb0.67)O3 0.3(PbTiO3) epitaxial superlatticesMar 30 2007A set of symmetric and asymmetric superlattices with ferromagnetic La0.6Sr0.4MnO3 and ferroelectric 0.7Pb(Mg0.33Nb0.67)O3 0.3(PbTiO3) as the constituting layers were fabricated on LaNiO3 coated (100) oriented LaAlO3 substrates using pulsed laser ablation. ... More
Coupled Phonons, Magnetic Excitations and Ferroelectricity in AlFeO3: Raman and First-principles StudiesApr 28 2012We determine the nature of coupled phonons and magnetic excitations in AlFeO3 using inelastic light scattering from 5 K to 315 K covering a spectral range from 100-2200 cm-1 and complementary first-principles density functional theory-based calculations. ... More
Near room-temperature colossal magnetodielectricity and multiglass properties in partially-disordered La2NiMnO6Feb 20 2012Apr 27 2012We report magnetic, dielectric and magnetodielectric responses of pure monoclinic bulk phase of partially-disordered La2NiMnO6, exhibiting a spectrum of unusual properties and establish that this system intrinsically is a true multiglass with a large ... More
Highly tunable magnetic spirals and electric polarization in Gd$_{0.5}$Dy$_{0.5}$MnO$_3$Mar 05 2019Recent progress in the field of multiferroics led to the discovery of many new materials in which ferroelectricity is induced by cycloidal spiral orders. The direction of the electric polarization is typically constrained by spin anisotropies and magnetic ... More
Tuning of dielectric properties and magnetism of SrTiO3 by site-specific doping of MnSep 24 2010Oct 01 2011Combining experiments with first principles calculations, we show that site-specific doping of Mn into SrTiO3 has a decisive influence on the dielectric properties of these doped systems. We find that phonon contributions to the dielectric constant invariably ... More