Results for "Petar Veličković"

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X-CNN: Cross-modal Convolutional Neural Networks for Sparse DatasetsOct 01 2016In this paper we propose cross-modal convolutional neural networks (X-CNNs), a novel biologically inspired type of CNN architectures, treating gradient descent-specialised CNNs as individual units of processing in a larger-scale network topology, while ... More
Graph Attention NetworksOct 30 2017Feb 04 2018We present graph attention networks (GATs), novel neural network architectures that operate on graph-structured data, leveraging masked self-attentional layers to address the shortcomings of prior methods based on graph convolutions or their approximations. ... More
XFlow: 1D-2D Cross-modal Deep Neural Networks for Audiovisual ClassificationSep 02 2017We propose two multimodal deep learning architectures that allow for cross-modal dataflow (XFlow) between the feature extractors, thereby extracting more interpretable features and obtaining a better representation than through unimodal learning, for ... More
Automatic Inference of Cross-modal Connection Topologies for X-CNNsMay 02 2018This paper introduces a way to learn cross-modal convolutional neural network (X-CNN) architectures from a base convolutional network (CNN) and the training data to reduce the design cost and enable applying cross-modal networks in sparse data environments. ... More
Quantifying the Effects of Enforcing Disentanglement on Variational AutoencodersNov 24 2017The notion of disentangled autoencoders was proposed as an extension to the variational autoencoder by introducing a disentanglement parameter $\beta$, controlling the learning pressure put on the possible underlying latent representations. For certain ... More
XFlow: Cross-modal Deep Neural Networks for Audiovisual ClassificationSep 02 2017Apr 12 2019In recent years, there have been numerous developments towards solving multimodal tasks, aiming to learn a stronger representation than through a single modality. Certain aspects of the data can be particularly useful in this case - for example, correlations ... More
Attentive cross-modal paratope predictionJun 12 2018Antibodies are a critical part of the immune system, having the function of directly neutralising or tagging undesirable objects (the antigens) for future destruction. Being able to predict which amino acids belong to the paratope, the region on the antibody ... More
ChronoMID - Cross-Modal Neural Networks for 3-D Temporal Medical Imaging DataJan 12 2019ChronoMID builds on the success of cross-modal convolutional neural networks (X-CNNs), making the novel application of the technique to medical imaging data. Specifically, this paper presents and compares alternative approaches - timestamps and difference ... More
X-CNN: Cross-modal Convolutional Neural Networks for Sparse DatasetsOct 01 2016Oct 17 2016In this paper we propose cross-modal convolutional neural networks (X-CNNs), a novel biologically inspired type of CNN architectures, treating gradient descent-specialised CNNs as individual units of processing in a larger-scale network topology, while ... More
Towards Sparse Hierarchical Graph ClassifiersNov 03 2018Recent advances in representation learning on graphs, mainly leveraging graph convolutional networks, have brought a substantial improvement on many graph-based benchmark tasks. While novel approaches to learning node embeddings are highly suitable for ... More
Deep Graph InfomaxSep 27 2018Dec 21 2018We present Deep Graph Infomax (DGI), a general approach for learning node representations within graph-structured data in an unsupervised manner. DGI relies on maximizing mutual information between patch representations and corresponding high-level summaries ... More
Spatio-Temporal Deep Graph InfomaxApr 12 2019Spatio-temporal graphs such as traffic networks or gene regulatory systems present challenges for the existing deep learning methods due to the complexity of structural changes over time. To address these issues, we introduce Spatio-Temporal Deep Graph ... More
Borel partitions of infinite subtrees of a perfect treeJan 15 1993A theorem of Galvin asserts that if the unordered pairs of reals are partitioned into finitely many Borel classes then there is a perfect set P such that all pairs from P lie in the same class. The generalization to n-tuples for n >= 3 is false. Let us ... More
Drug-Drug Adverse Effect Prediction with Graph Co-AttentionMay 02 2019Complex or co-existing diseases are commonly treated using drug combinations, which can lead to higher risk of adverse side effects. The detection of polypharmacy side effects is usually done in Phase IV clinical trials, but there are still plenty which ... More
Topological complexity of a fibrationSep 24 2018We study certain topological problems that are inspired by applications to autonomous robot manipulation. Consider a continuous map $f\colon X\to Y$, where $f$ can be a kinematic map from the configuration space $X$ to the working space $Y$ of a robot ... More
Einstein's Lost Battles and Neglected AchievementsSep 28 2007We analyze some of Einstein's failures to accomplish tasks which he posed to himself, notably deterministic interpretation of Quantum mechanics and formulation of the Unified theory of physical interactions, putting them into broader ontological and epistemological ... More
Monotonicity of the Schwarz genusJan 03 2019Schwarz genus $\mathsf{g}(\xi)$ of a fibration $\xi\colon E\to B$ is defined as the minimal integer $n$, such that there exists a cover of $B$ by $n$ open sets that admit partial section to $\xi$. Many important concepts, including Lusternik-Schnirelmann ... More
A Topologist's View of Kinematic Maps and Manipulation ComplexityJul 12 2017In this paper we combine a survey of the most important topological properties of kinematic maps that appear in robotics, with the exposition of some basic results regarding the topological complexity of a map. In particular, we discuss mechanical devices ... More
Theta lifts of generic representations for dual pairs $(\mathrm{Sp}_{2n}, \mathrm{O}(V))$Nov 10 2018We determine the occurrence and explicitly describe the theta lifts on all levels of all the irreducible generic representations for the dual pair of groups $(\mathrm{Sp}_{2n}, \mathrm{O}(V))$ defined over a local nonarchimedean field $\mathbb{F}$ of ... More
A proof of the Khavinson conjectureMar 11 2019Mar 27 2019\begin{abstract} This paper deals with an extremal problem for bounded harmonic functions in the unit ball $\mathbb{B}^n.$ We solve the Khavinson conjecture in $\mathbb{R}^3,$ an intriguing open question since 1992 posed by D. Khavinson, later considered ... More
A proof of the Khavinson conjectureMar 11 2019\begin{abstract} This paper deals with an extremal problem for bounded harmonic functions in the unit ball $\mathbb{B}^n.$ We solve the Khavinson conjecture in $\mathbb{R}^3,$ an intriguing open question since 1992 posed by D. Khavinson, later considered ... More
Triangulations with few vertices of manifolds with non-free fundamental groupJan 15 2018We study lower bounds for the number of vertices in a PL-triangulation of a given manifold $M$. While most of the previous estimates are based on the dimension and the connectivity of $M$, we show that further information can be extracted by studying ... More
Cross-modal Recurrent Models for Weight Objective Prediction from Multimodal Time-series DataSep 23 2017Nov 29 2017We analyse multimodal time-series data corresponding to weight, sleep and steps measurements. We focus on predicting whether a user will successfully achieve his/her weight objective. For this, we design several deep long short-term memory (LSTM) architectures, ... More
Markov Process Simulation with Quantum ComputerJun 15 2018Jun 18 2018This paper shows a novel way of simulating a Markov process by a quantum computer. The main purpose of the paper is to show a particular application of quantum computing in the field of stochastic processes analysis. Using a Quantum computer, the process ... More
Topological complexity of a mapSep 24 2018Jun 10 2019We study certain topological problems that are inspired by applications to autonomous robot manipulation. Consider a continuous map $f\colon X\to Y$, where $f$ can be a kinematic map from the configuration space $X$ to the working space $Y$ of a robot ... More
Complexity of the forward kinematic mapAug 02 2017The main objective of this paper is to introduce a new method for qualitative analysis of various designs of robot arms. To this end we define the complexity of a map, examine its main properties and develop some methods of computation. In particular, ... More
A note on mean-value properties of harmonic functions on the hypercubeJun 16 2015Aug 20 2015For functions defined on the $n$-dimensional hypercube $I_n (r) = \{{\bm{x}} \in \mathbb{R}^n ~\vert~ \vert x_i \vert \le r,~ i = 1, 2, \ldots , n\}$ and harmonic therein, we establish certain analogues of Gauss surface and volume mean-value formulas ... More
Some epistemic questions of cosmologySep 20 2007We discuss a number of fundamental aspects of modern cosmological concepts, from the phenomenological, observational, theoretical and epistemic points of view. We argue that the modern cosmology, despite a great advent, in particular in the observational ... More
Two-Way Communication with Energy ExchangeApr 09 2012The conventional assumption made in the design of communication systems is that the energy used to transfer information between a sender and a recipient cannot be reused for future communication tasks. A notable exception to this norm is given by passive ... More
Wireless Secrecy in Cellular Systems with Infrastructure--Aided CooperationMay 03 2008In cellular systems, confidentiality of uplink transmission with respect to eavesdropping terminals can be ensured by creating intentional inteference via scheduling of concurrent downlink transmissions. In this paper, this basic idea is explored from ... More
A Transposition Rule Analysis Based on a Particle ProcessApr 02 2004Jun 12 2005A linear list is a collection of items that can be accessed sequentially. The cost of a request is the number of items that need to be examined before the desired item is located, i.e., the distance of the requested item from the beginning of the list. ... More
Subspace acceleration for large-scale parameter-dependent Hermitian eigenproblemsApr 23 2015This work is concerned with approximating the smallest eigenvalue of a parameter-dependent Hermitian matrix $A(\mu)$ for many parameter values $\mu \in \mathbb{R}^P$. The design of reliable and efficient algorithms for addressing this task is of importance ... More
Coded Slotted ALOHA with Varying Packet Loss Rate across UsersJun 29 2013The recent research has established an analogy between successive interference cancellation in slotted ALOHA framework and iterative belief-propagation erasure-decoding, which has opened the possibility to enhance random access protocols by utilizing ... More
Bethe-Salpeter approach to the collective-mode spectrum of a superfluid Fermi gas in a moving optical latticeMar 10 2011We have derived the Bethe-Salpeter (BS) equations for the collective-mode spectrum of a mixture of fermion atoms of two hyperfine states loaded into a moving optical lattice. The collective excitation spectrum exhibits rotonlike minimum and the Landau ... More
Protocol Coding through Reordering of User Resources, Part I: Capacity ResultsFeb 01 2012The vast existing wireless infrastructure features a variety of systems and standards. It is of significant practical value to introduce new features and devices without changing the physical layer/hardware infrastructure, but upgrade it only in software. ... More
Electric routing and concurrent flow cuttingSep 15 2009We investigate an oblivious routing scheme, amenable to distributed computation and resilient to graph changes, based on electrical flow. Our main technical contribution is a new rounding method which we use to obtain a bound on the L1->L1 operator norm ... More
Start Making Sense: Semantic Plane Filtering and Control for Post-5G ConnectivityJan 18 2019This is a short position paper that introduces the concepts of semantic plane filtering and control for post-5G connectivity.
Spaces with high topological complexityApr 23 2012Oct 23 2012By a formula of Farber the topological complexity TC(X) of a (p-1)-connected, m-dimensional CW-complex X is bounded above by (2m+1)/p+1. There are also various lower estimates for TC(X) such as the nilpotency of the ring $H^*(X\times X,\Delta(X))$, and ... More
Lower bounds for topological complexityOct 31 2011Apr 20 2013We introduce fibrewise Whitehead- and fibrewise Ganea definitions of monoidal topological complexity. We then define several lower bounds for the topological complexity, which improve on the standard lower bound in terms of nilpotency of the cohomology ... More
Parking functions and tree inversions revisitedJun 10 2015Feb 02 2016Kreweras proved that the reversed sum enumerator for parking functions of length $n$ is equal to the inversion enumerator for labeled trees on $n+1$ vertices. Recently, Perkinson, Yang, and Yu gave a bijective proof of this equality that moreover generalizes ... More
Experimental Realization of Controlled Square Root of Z Gate Using IBM's Cloud Quantum Experience PlatformJun 07 2018Quantum computers form a technological cluster with huge growth in the last few years. Although this technology is of still very limited size: perhaps the reason it is not seen as a technology which may be mass produced or of public use in the near future: ... More
Zero-Error Capacity of a Class of Timing ChannelsNov 06 2013Aug 24 2014We analyze the problem of zero-error communication through timing channels that can be interpreted as discrete-time queues with bounded waiting times. The channel model includes the following assumptions: 1) Time is slotted, 2) at most $ N $ "particles" ... More
Compressed sensing MRI using masked DCT and DFT measurementsMar 25 2015This paper presents modification of the TwIST algorithm for Compressive Sensing MRI images reconstruction. Compressive Sensing is new approach in signal processing whose basic idea is recovering signal form small set of available samples. The application ... More
Steady-state analysis of a multi-server queue in the Halfin-Whitt regimeOct 02 2007Mar 18 2008We consider a multi-server queue in the Halfin-Whitt regime: as the number of servers $n$ grows without a bound, the utilization approaches 1 from below at the rate $\Theta(1/\sqrt{n})$. Assuming that the service time distribution is lattice-valued with ... More
SU(3)-instantons and $G_2, Spin(7)$-heterotic string solitonsDec 03 2003Feb 24 2005Necessary and sufficient conditions to the existence of a hermitian connection with totally skew-symmetric torsion and holonomy contained in SU(3) are given. Non-compact solution to the supergravity-type I equations of motion with non-zero flux and non-constant ... More
Generic representations of metaplectic groups and their theta liftsFeb 20 2019In this paper we give the description of generic representations of metaplectic groups over p-adic fields in terms of their Langlands parameters and calculate their theta lifts on all levels for any tower of odd orthogonal groups. We also describe precisely ... More
Information carrying capacity of a cosmological constantAug 19 2016Jan 05 2017We analyze the exchange of information in different cosmological backgrounds when sender and receiver are timelike separated and communicate through massless fields (without the exchange of light-signals). Remarkably, we show that the dominance of a cosmological ... More
Reliable Reception of Wireless Metering Data with Protocol CodingMay 21 2013Stationary collectors reading wireless, battery powered smart meters, often operate in harsh channel conditions to cut network installation cost to a minimum, challenging the individual link to each meter. The desired performance measure is reliable reception ... More
Zero-Outage Cellular Downlink with Fixed-Rate D2D UnderlayApr 28 2014Dec 30 2014Two of the emerging trends in wireless cellular systems are Device-to-Device (D2D) and Machine-to-Machine (M2M) communications. D2D enables efficient reuse of the licensed spectrum to support localized transmissions, while M2M connections are often characterized ... More
Non-perturbative analysis of entanglement harvesting from coherent field statesJun 30 2017We study (non-perturbatively) the interactions of delta-coupled detectors with coherent states of a scalar field. We show that the time-evolved density matrix spectra of i) a single detector, ii) two detectors, and iii) the partial transpose of the latter, ... More
Surface roughness evolution in a solid-on-solid model of epitaxial growthJan 02 2014Aug 14 2014The paper presents results from kinetic Monte Carlo simulations of kinetic surface roughening using an important and experimentally relevant model of epitaxial growth -- the solid-on-solid model with Arrhenius dynamics. A restriction on diffusing adatoms ... More
The information carrying capacity of a cosmological constantAug 19 2016We analyze the exchange of information in different cosmological backgrounds when sender and receiver are timelike separated and communicate through massless fields (without the exchange of light-signals). Remarkably, we show that the dominance of a cosmological ... More
Minimizing the Age of Information from Sensors with Correlated ObservationsNov 15 2018The Age of Information (AoI) metric has recently received much attention as a measure of freshness of information in a network. In this paper, we study the average AoI in a generic setting with correlated sensor information, which can be related to multiple ... More
Harvesting correlations from thermal and squeezed coherent statesSep 14 2018We study the harvesting of entanglement and mutual information by Unruh-DeWitt particle detectors from thermal and squeezed coherent field states. We prove (for arbitrary spatial dimensions, switching profiles and detector smearings) that while the entanglement ... More
All coherent field states entangle equallyMay 11 2017We analyze the interactions of particle detectors with coherent states of a free scalar field. We find that the eigenvalues of the post-interaction density matrices of i) a single detector, ii) two detectors, and iii) the partial transpose of the latter, ... More
Minimizing the Age of Information from Sensors with Common ObservationsNov 15 2018Mar 19 2019We study the average Age of Information (AoI) in a system where physical sources produce independent discrete-time updates that are each observed by several sensors. We devise a model that is simple, but still capable to capture the main tradeoffs. Two ... More
Sign-Compute-Resolve for Tree Splitting Random AccessFeb 08 2016We present an approach to random access that is based on three elements: physical-layer network coding (PLNC), signature codes and tree splitting. In presence of a collision, physical-layer network coding enables the receiver to decode, i.e. compute the ... More
Adapting the Number of Particles in Sequential Monte Carlo Methods through an Online Scheme for Convergence AssessmentSep 16 2015Particle filters are broadly used to approximate posterior distributions of hidden states in state-space models by means of sets of weighted particles. While the convergence of the filter is guaranteed when the number of particles tends to infinity, the ... More
Multikast rutiranje open-source platformom - XORPDec 03 2017Integration of a software router into embedded systems is obtained possibility of the most modern routers, at a much more affordable price. Transfer services TV and radio signals over the IP network are only activated by using multicast 1 protocol for ... More
Communications with decode-and-forward relays in mesh networksOct 16 2012We consider mesh networks composed of groups of relaying nodes which operate in decode-and-forward mode, where each node from a group relays information to all the nodes in the next group. We study these networks in two setups, one where the nodes have ... More
Optimized Interface Diversity for Ultra-Reliable Low Latency Communication (URLLC)Dec 14 2017An important ingredient of the future 5G systems will be Ultra-Reliable Low-Latency Communication (URLLC). A way to offer URLLC without intervention in the baseband/PHY layer design is to use \emph{interface diversity} and integrate multiple communication ... More
Decoupled Uplink and Downlink in a Wireless System with Buffer-Aided RelayingSep 21 2016Sep 22 2016The paper treats a multiuser relay scenario where multiple user equipments (UEs) have a two-way communication with a common Base Station (BS) in the presence of a buffer-equipped Relay Station (RS). Each of the uplink (UL) and downlink (DL) transmission ... More
Geodesic equivalence and integrabilityNov 10 1999We suggest a construction that, given a trajectorial diffeomorphism between two Hamiltonian systems, produces integrals of them. As the main example we treat geodesic equivalence of metrics. We show that the existence of a non-trivially geodesically equivalent ... More
Information-Centric Grant-Free Access for IoT Fog Networks: Edge vs Cloud Detection and LearningJul 11 2019A multi-cell Fog-Radio Access Network (F-RAN) architecture is considered in which Internet of Things (IoT) devices periodically make noisy observations of a Quantity of Interest (QoI) and transmit using grant-free access in the uplink. The devices in ... More
Geometry of compact lifting spacesJan 07 2019We study a natural generalization of inverse systems of finite regular covering spaces. A limit of such a system is a fibration whose fibres are profinite topological groups. However, as shown in a previous paper (Conner-Herfort-Pavesic: Some anomalous ... More
Adapting the Number of Particles in Sequential Monte Carlo Methods through an Online Scheme for Convergence AssessmentSep 16 2015Oct 31 2017Particle filters are broadly used to approximate posterior distributions of hidden states in state-space models by means of sets of weighted particles. While the convergence of the filter is guaranteed when the number of particles tends to infinity, the ... More
Estimates of covering type and the number of vertices of minimal triangulationsOct 09 2017Jun 29 2019The covering type of a space $X$ is defined as the minimal cardinality of a good cover of a space that is homotopy equivalent to $X$. We derive estimates for the covering type of $X$ in terms of other invariants of $X$, namely the ranks of the homology ... More
Dynamical and Topological methods in Theory of Geodesically Equivalent MetricsNov 09 1999This paper is a review on recently found connection between geodesically equivalent metrics and integrable geodesic flows. Suppose two different metrics on one manifold have the same geodesics. We show that then the geodesic flows of these metrics admit ... More
Inter-plane satellite matching in dense LEO constellationsMay 21 2019Dense constellations of Low Earth Orbit (LEO) small satellites are envisioned to extend the coverage of IoT applications via the inter-satellite link (ISL). Within the same orbital plane, the inter-satellite distances are preserved and the links are rather ... More
Action Branching Architectures for Deep Reinforcement LearningNov 24 2017Jan 25 2019Discrete-action algorithms have been central to numerous recent successes of deep reinforcement learning. However, applying these algorithms to high-dimensional action tasks requires tackling the combinatorial increase of the number of possible actions ... More
Analysis of LT Codes with Unequal Recovery TimeApr 20 2012In this paper we analyze a specific class of rateless codes, called LT codes with unequal recovery time. These codes provide the option of prioritizing different segments of the transmitted data over other. The result is that segments are decoded in stages ... More
Design and Analysis of LT Codes with Decreasing Ripple SizeNov 09 2010Jun 07 2012In this paper we propose a new design of LT codes, which decreases the amount of necessary overhead in comparison to existing designs. The design focuses on a parameter of the LT decoding process called the ripple size. This parameter was also a key element ... More
Classical gravity is safe from an ultraviolet catastropheMay 16 2019Max Planck famously showed that the ultraviolet catastrophe of the classical electromagnetic radiation emitted by a black body is avoided by the quantization of electromagnetism. Does it follow, analogously, that in order to avoid an ultraviolet catastrophe ... More
Visuospatial Skill Learning for RobotsJun 03 2017A novel skill learning approach is proposed that allows a robot to acquire human-like visuospatial skills for object manipulation tasks. Visuospatial skills are attained by observing spatial relationships among objects through demonstrations. The proposed ... More
5G Ultra-Reliable Vehicular CommunicationOct 05 2015Oct 08 2015Applications enabled by Cooperative Intelligent Transport Systems (C-ITS) represent a major step towards making the road transport system safer and more efficient (green), and thus suited for a sustainable future. Wireless communication between vehicles ... More
Scotogenic R\nuMDM at Three-Loop LevelFeb 27 2015Mar 30 2015We propose a model in which the radiative neutrino (R\nu) masses are induced by fermion quintuplet and scalar septuplet fields from the minimal-dark-matter (MDM) setup. In conjunction with the 2HDM fields, on top of which our model is built, these hypercharge ... More
Using Wireless Network Coding to Replace a Wired with Wireless BackhaulApr 14 2014Cellular networks are evolving towards dense deployment of small cells. This in turn demands flexible and efficient backhauling solutions. A viable solution that reuses the same spectrum is wireless backhaul where the Small Base Station (SBS) acts as ... More
Physical Layer Network Coding: A Cautionary Story with Interference and Spatial ReservationNov 06 2013Physical layer network coding (PLNC) has the potential to improve throughput of multi-hop networks. However, most of the works are focused on the simple, three-node model with two-way relaying, not taking into account the fact that there can be other ... More
Afterglow Model for the Radio Emission from the Jetted Tidal Disruption Candidate Swift J1644+57Oct 05 2011Jun 12 2012The recent transient event Swift J1644+57 has been interpreted as emission from a collimated relativistic jet, powered by the sudden onset of accretion onto a supermassive black hole following the tidal disruption of a star. Here we model the radio-microwave ... More
Estimates of covering type and the number of vertices of minimal triangulationsOct 09 2017The covering type of a space $X$ is defined as the minimal cardinality of a good cover of a space that is homotopy equivalent to $X$. We derive estimates for the covering type of $X$ in terms of other invariants of $X$, namely the ranks of the homology ... More
Towards Massive, Ultra-Reliable, and Low-Latency Wireless Communication with Short PacketsApr 24 2015Mar 01 2016Most of the recent advances in the design of high-speed wireless systems are based on information-theoretic principles that demonstrate how to efficiently transmit long data packets. However, the upcoming wireless systems, notably the 5G system, will ... More
INFRAWEBS axiom editor - a graphical ontology-driven tool for creating complex logical expressionsApr 02 2009Jan 07 2012The current INFRAWEBS European research project aims at developing ICT framework enabling software and service providers to generate and establish open and extensible development platforms for Web Service applications. One of the concrete project objectives ... More
On Buffer-Aided Multiple-Access Relay ChannelSep 21 2016Sep 22 2016The paper treats uplink scenario where M user equipments (UEs) send to a Base Station (BS), possibly via a common Relay Station (RS) that is equipped with a buffer. This is a multiple-access relay channel (MARC) aided by a buffer. We devise a protocol ... More
Coexistence of URLLC and eMBB services in the C-RAN Uplink: An Information-Theoretic StudyApr 18 2018The performance of orthogonal and non-orthogonal multiple access is studied for the multiplexing of enhanced Mobile BroadBand (eMBB) and Ultra-Reliable Low-Latency Communications (URLLC) users in the uplink of a multi-cell Cloud Radio Access Network (C-RAN) ... More
Minimizing Latency to Support VR Social Interactions over Wireless Cellular Systems via Bandwidth AllocationFeb 09 2018Apr 04 2018Immersive social interactions of mobile users are soon to be enabled within a virtual space, by means of virtual reality (VR) technologies and wireless cellular systems. In a VR mobile social network, the states of all interacting users should be updated ... More
Delay Minimization in Real-time Communications with Joint Buffering and CodingOct 14 2016We present a closed-form expression for the minimal delay that is achievable in a setting that combines a buffer and an erasure code, used to mitigate the packet delay variance. The erasure code is modeled according to the recent information-theoretic ... More
Some anomalous examples of lifting spacesAug 02 2017An inverse limit of a sequence of covering spaces over a given space $X$ is not, in general, a covering space over $X$ but is still a lifting space, i.e. a Hurewicz fibration with unique path lifting property. Of particular interest are inverse limits ... More
Information-Centric Grant-Free Access for IoT Fog Networks: Edge vs Cloud Detection and LearningJul 11 2019Jul 12 2019A multi-cell Fog-Radio Access Network (F-RAN) architecture is considered in which Internet of Things (IoT) devices periodically make noisy observations of a Quantity of Interest (QoI) and transmit using grant-free access in the uplink. The devices in ... More
Coded Splitting Tree ProtocolsJan 30 2013This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree ... More
On the Role of Feedback in LT CodesDec 13 2010This paper concerns application of feedback in LT codes. The considered type of feedback is acknowledgments, where information on which symbols have been decoded is given to the transmitter. We identify an important adaptive mechanism in standard LT codes, ... More
Buffer-Aided Relaying with Adaptive Link SelectionFeb 24 2012Oct 13 2012In this paper, we consider a simple network consisting of a source, a half-duplex decode-and-forward relay, and a destination. We propose a new relaying protocol employing adaptive link selection, i.e., in any given time slot, based on the channel state ... More
Ultra-Reliable Low Latency Communication (URLLC) using Interface DiversityNov 21 2017An important ingredient of the future 5G systems will be Ultra-Reliable Low-Latency Communication (URLLC). A way to offer URLLC without intervention in the baseband/PHY layer design is to use interface diversity and integrate multiple communication interfaces, ... More
Delivery Latency Trade-Offs of Heterogeneous Contents in Fog Radio Access NetworksJan 23 2017Apr 18 2017A Fog Radio Access Network (F-RAN) is a cellular wireless system that enables content delivery via the caching of popular content at edge nodes (ENs) and cloud processing. The existing information-theoretic analyses of F-RAN systems, and special cases ... More
Reliability-Latency Performance of Frameless ALOHA with and without FeedbackJul 15 2019This paper presents a finite length analysis of multi-slot type frameless ALOHA based on a dynamic programming approach. The analysis is exact, but its evaluation is only feasible for short contention periods due to the computational complexity. The analysis ... More
Massive Random Access with Common Alarm MessagesJan 18 2019The established view on massive IoT access is that the IoT devices are activated randomly and independently. This is a basic premise also in the recent information-theoretic treatment of massive access by Polyanskiy. In a number of practical scenarios, ... More
Convergent measure of focal extent, and largest peak intensity for non-paraxial beamsApr 26 2018Jun 06 2018Second moment beam widths are commonly used in paraxial optics to define the focal extent of beams. However, second moments of arbitrary beams are not guaranteed to be finite. I propose the focal concentration area as a measure of beam focal area, defined ... More
Norm of the Bergman projection onto the Bloch space with $\mathcal{M}-$invariant gradientNov 23 2017May 18 2018The value of the operator norm of Bergman projections from $L^{\infty}(\mathbb{B}^n)$ to Bloch space is found in \cite{KalajMarkovic2014}. The authors of mentioned paper proposed the problem of calculating the norm of the same class of operators with ... More
Economic impact of IoT cyber risk - Analysing past and present to predict the future developments in IoT risk analysis and IoT cyber insuranceOct 13 2018This paper is focused on mapping the current evolution of Internet of Things (IoT) and its associated cyber risks for the Industry 4.0 (I4.0) sector. We report the results of a qualitative empirical study that correlates academic literature with 14 - ... More
Global Computation in a Poorly Connected World: Fast Rumor Spreading with No Dependence on ConductanceApr 14 2011In this paper, we study the question of how efficiently a collection of interconnected nodes can perform a global computation in the widely studied GOSSIP model of communication. In this model, nodes do not know the global topology of the network, and ... More
Modeling Frequency and Severity of Claims with the Zero-Inflated Generalized Cluster-Weighted ModelsDec 31 2018In this paper, we propose two important extensions to cluster-weighted models (CWMs). First, we extend CWMs to have generalized cluster-weighted models (GCWMs) by allowing modeling of non-Gaussian distribution of the continuous covariates, as they frequently ... More