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Results for "Gudjon Einar Magnusson"

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Metamorphic Detection of Adversarial Examples in Deep Learning Models With Affine TransformationsJul 10 2019Adversarial attacks are small, carefully crafted perturbations, imperceptible to the naked eye; that when added to an image cause deep learning models to misclassify the image with potentially detrimental outcomes. With the rise of artificial intelligence ... More
Quantum Acoustics with Surface Acoustic WavesJun 04 2015It has recently been demonstrated that surface acoustic waves (SAWs) can interact with superconducting qubits at the quantum level. SAW resonators in the GHz frequency range have also been found to have low loss at temperatures compatible with superconducting ... More
Fundamental issues in nonlinear wideband-vibration energy harvestingSep 14 2012May 02 2013Mechanically nonlinear energy harvesters driven by broadband vibrations modeled as white noise are investigated. We derive an upper bound on output power versus load resistance and show that, subject to mild restrictions that we make precise, the upper-bound ... More
The Coloring Ideal and Coloring Complex of a GraphApr 05 2001Let $G$ be a simple graph on $d$ vertices. We define a monomial ideal $K$ in the Stanley-Reisner ring $A$ of the order complex of the Boolean algebra on $d$ atoms. The monomials in $K$ are in one-to-one correspondence with the proper colorings of $G$. ... More
Generalized permutation patterns -- a short surveyJan 16 2008May 31 2008An occurrence of a classical pattern p in a permutation \pi is a subsequence of \pi whose letters are in the same relative order (of size) as those in p. In an occurrence of a generalized pattern, some letters of that subsequence may be required to be ... More
Statistics on ordered partitions of setsMay 26 2006Sep 02 2014We introduce several statistics on ordered partitions of sets, that is, set partitions where the blocks are permuted arbitrarily. The distribution of these statistics is closely related to the q-Stirling numbers of the second kind. Some of the statistics ... More
Evaluation of a length-based method to estimate discard rate and the effect of sampling sizeFeb 27 2019The common fisheries policy aims at eliminating discarding which has been part of fisheries for centuries. It is important to monitor the compliance with the new regulations but estimating the discard rate is a challenging task, especially where the practise ... More
Random Walks and Mixed Volumes of HypersimplicesJul 20 2012Below is a method for relating a mixed volume computation for polytopes sharing many facet directions to a symmetric random walk. The example of permutahedra and particularly hypersimplices is expanded upon.
A Simple Reinforcement Learning Mechanism for Resource Allocation in LTE-A Networks with Markov Decision Process and Q-LearningSep 27 2017Resource allocation is still a difficult issue to deal with in wireless networks. The unstable channel condition and traffic demand for Quality of Service (QoS) raise some barriers that interfere with the process. It is significant that an optimal policy ... More
The Pfaffian Calabi-Yau, its Mirror, and their link to the Grassmannian G(2,7)Jan 20 1998The rank 4 locus of a general skew-symmetric 7x7 matrix gives the pfaffian variety in P^20 which is not defined as a complete intersection. Intersecting this with a general P^6 gives a Calabi-Yau manifold. An orbifold construction seems to give the 1-parameter ... More
Extremal omega-plurisubharmonic functions as envelopes of disc functionals - Generalization and applications to the local theoryMar 22 2011Jul 19 2011We generalize the Poletsky disc envelope formula for the function $\sup \{u \in \PSH(X,\omega) ; u\leq \phi\}$ on any complex manifold $X$ to the case where the real (1,1)-current $\omega=\omega_1-\omega_2$ is the difference of two positive closed (1,1)-currents ... More
New principle for unpolarized wideband reflectorsJan 06 2016There is immense scientific interest in the properties of resonant thin films embroidered with periodic nanoscale features. This device class possesses considerable innovation potential. Accordingly, we report unpolarized broadband reflectors enabled ... More
Extremal omega-plurisubharmonic functions as envelopes of disc functionalsJun 04 2009Apr 11 2010For each closed, positive (1,1)-current \omega on a complex manifold X and each \omega-upper semicontinuous function \phi on X we associate a disc functional and prove that its envelope is equal to the supremum of all \omega-plurisubharmonic functions ... More
Analytic Discs, Global Extremal Functions and Projective Hulls in Projective SpaceApr 05 2013May 21 2013Using a recent result of L\'arusson and Poletsky regarding plurisubharmonic subextensions we prove a disc formula for the quasiplurisubharmonic global extremal function for domains in complex projective space. As a corollary we get a characterization ... More
TALplanner in IPC-2002: Extensions and Control RulesJun 26 2011TALplanner is a forward-chaining planner that relies on domain knowledge in the shape of temporal logic formulas in order to prune irrelevant parts of the search space. TALplanner recently participated in the third International Planning Competition, ... More
Decreasing subsequences in permutations and Wilf equivalence for involutionsMay 17 2004In a recent paper, Backelin, West and Xin describe a map $\phi ^*$ that recursively replaces all occurrences of the pattern $k... 21$ in a permutation $\sigma$ by occurrences of the pattern $(k-1)... 21 k$. The resulting permutation $\phi^*(\sigma)$ contains ... More
Image-Based Size Analysis of Agglomerated and Partially Sintered Particles via Convolutional Neural NetworksJul 11 2019There is a high demand for fully automated methods for the analysis of particle size distributions of agglomerated, sintered or occluded primary particles. Therefore, a novel, deep learning-based, method for the pixel-perfect detection and sizing of agglomerated, ... More
Mitigating Deep Learning Vulnerabilities from Adversarial Examples Attack in the Cybersecurity DomainMay 09 2019Deep learning models are known to solve classification and regression problems by employing a number of epoch and training samples on a large dataset with optimal accuracy. However, that doesn't mean they are attack-proof or unexposed to vulnerabilities. ... More
On the General Classification of Lie Bialgebra Structures over PolynomialsApr 09 2010The present paper is a continuation of [5], where Lie bialgebra structures on g[u] were studied. These structures fall into different classes labelled by the vertices of the extended Dynkin diagram of g. In [5] the Lie bialgebras corresponding to the ... More
Fully automated primary particle size analysis of agglomerates on transmission electron microscopy images via artificial neural networksJun 08 2018There is a high demand for fully automated methods for the analysis of primary particle size distributions of agglomerates on transmission electron microscopy images. Therefore, a novel method, based on the utilization of artificial neural networks, was ... More
Integer Arithmetic With Hybrid Quantum-Classical CircuitsApr 15 2013Quantum circuits which perform integer arithmetic could potentially outperform their classical counterparts. In this paper, a quantum circuit is considered which performs a specific computational pattern on classically represented integers to accelerate ... More
Permutation Tableaux and Permutation PatternsJul 07 2005Apr 22 2006In this paper we introduce and study a class of tableaux which we call permutation tableaux; these tableaux are naturally in bijection with permutations, and they are a distinguished subset of the Le-diagrams of Alex Postnikov. The structure of these ... More
Dark Energy and the Observable UniverseMay 31 2001Sep 25 2001We consider ever-expanding Big Bang models with a cosmological constant, $\Lambda$, and investigate in detail the evolution of the observable part of the universe. We also discuss quintessence models from the same point of view. A new concept, the $\Lambda$-sphere ... More
2D Map Alignment With Region DecompositionSep 01 2017Jun 30 2018In many applications of autonomous mobile robots the following problem is encountered. Two maps of the same environment are available, one a prior map and the other a sensor map built by the robot. To benefit from all available information in both maps, ... More
New $r$-Matrices for Lie Bialgebra Structures over PolynomialsOct 22 2009Oct 26 2009For a finite dimensional simple complex Lie algebra $\mathfrak{g}$, Lie bialgebra structures on $\mathfrak{g}[[u]]$ and $\mathfrak{g}[u]$ were classified by Montaner, Stolin and Zelmanov. In our paper, we provide an explicit algorithm to produce $r$-matrices ... More
Band flips and bound-state transitions in leaky-mode photonic latticesApr 07 2018Leaky-mode photonic lattices exhibit intricate resonance effects originating in quasi-guided lateral Bloch modes. Key spectral properties are associated with phase-matched modes at the second (leaky) stop band. One band edge mode suffers radiation loss ... More
Disc formulas for the weighted Siciak-Zahariuta extremal functionDec 29 2006We prove a disc formula for the weighted Siciak-Zahariuta extremal function $V_{X,q}$ for an upper semicontinuous function $q$ on an open connected subset $X$ in $\C^n$. This function is also known as the weighted Green function with logaritmic pole at ... More
Image-Based Size Analysis of Agglomerated and Partially Sintered Particles via Convolutional Neural NetworksJul 11 2019Jul 12 2019There is a high demand for fully automated methods for the analysis of particle size distributions of agglomerated, sintered or occluded primary particles. Therefore, a novel, deep learning-based, method for the pixel-perfect detection and sizing of agglomerated, ... More
The Mobius Function of the Permutation Pattern PosetFeb 23 2009Jan 22 2010A permutation \tau contains another permutation \sigma as a pattern if \tau has a subsequence whose elements are in the same order with respect to size as the elements in \sigma. This defines a partial order on the set of all permutations, and gives a ... More
Measurement of Large Forces and Deflections in MicrostructuresMay 07 2008Properties of typical MEMS materials have been widely investigated. Mechanical properties of MEMS structures depend not only on the bulk material properties, but also structural factors. A measurement system has been made to measure force/deflection on ... More
Upper bounds for the Stanley-Wilf limit of 1324 and other layered patternsNov 24 2011We prove that the Stanley-Wilf limit of any layered permutation pattern of length $\ell$ is at most $4\ell^2$, and that the Stanley-Wilf limit of the pattern 1324 is at most 16. These bounds follow from a more general result showing that a permutation ... More
Sound Mixed-Precision Optimization with RewritingJul 07 2017Finite-precision arithmetic computations face an inherent tradeoff between accuracy and efficiency. The points in this tradeoff space are determined, among other factors, by different data types but also evaluation orders. To put it simply, the shorter ... More
Multivariate Analysis of Orthogonal Range Searching and Graph Distances Parameterized by TreewidthMay 18 2018We show that the eccentricities, diameter, radius, and Wiener index of an undirected $n$-vertex graph with nonnegative edge lengths can be computed in time $O(n\cdot \binom{k+\lceil\log n\rceil}{k} \cdot 2^k k^2 \log n)$, where $k$ is the treewidth of ... More
DOLDA - a regularized supervised topic model for high-dimensional multi-class regressionJan 31 2016Oct 20 2016Generating user interpretable multi-class predictions in data rich environments with many classes and explanatory covariates is a daunting task. We introduce Diagonal Orthant Latent Dirichlet Allocation (DOLDA), a supervised topic model for multi-class ... More
Fractional quantization of the ballistic conductance in electron and hole systemsDec 31 2010In the present article we give a brief overview of the theories of the 0.7 anomaly of the ballistic conductance. The special attantion is given to the concept of a fractional quantization of the ballistic conductance arising from exchange interaction ... More
Decompositions and statistics for beta(1,0)-trees and nonseparable permutationsJan 25 2008Mar 24 2010The subject of pattern avoiding permutations has its roots in computer science, namely in the problem of sorting a permutation through a stack. A formula for the number of permutations of length n that can be sorted by passing it twice through a stack ... More
Permutations sortable by n-4 passes through a stackNov 30 2008Feb 03 2009We characterise and enumerate permutations that are sortable by n-4 passes through a stack. We conjecture the number of permutations sortable by n-5 passes, and also the form of a formula for the general case n-k, which involves a polynomial expression. ... More
Voltage Control Using Limited CommunicationApr 03 2017In electricity distribution networks, the increasing penetration of renewable energy generation necessitates faster and more sophisticated voltage controls. Unfortunately, recent research shows that local voltage control fails in achieving the desired ... More
On-Demand WebRTC Tunneling in Restricted NetworksDec 23 2013In this paper we present the implementation of a WebRTC gateway service that can forward ad-hoc RTP data plane traffic from a browser on one local network to a browser on another local network. The advantage compared to the existing IETF STUN (RFC 5389), ... More
Single-periodic-film optical bandpass filterSep 09 2015Resonant periodic surfaces and films enable new functionalities with wide applicability in practical optical systems. Their material sparsity, ease of fabrication, and minimal interface count provide environmental and thermal stability and robustness ... More
Sparse Parallel Training of Hierarchical Dirichlet Process Topic ModelsJun 06 2019Nonparametric extensions of topic models such as Latent Dirichlet Allocation, including Hierarchical Dirichlet Process (HDP), are often studied in natural language processing. Training these models generally requires use of serial algorithms, which limits ... More
Classical quasi-trigonometric $r-$matrices of Cremmer-Gervais type and their quantizationDec 17 2006We propose a method of quantization of certain Lie bialgebra structures on the polynomial Lie algebras related to quasi-trigonometric solutions of the classical Yang-Baxter equation. The method is based on so-called affinization of certain seaweed algebras ... More
A Characterization of totally real Carleman continua and an application to products of stratified totally real setsOct 21 2013We give a characterization of stratified totally real sets that admit Carleman approximation by entire functions. As an application we show that the product of two stratified totally real Carleman continua is a Carleman continuum.
A method to segment maps from different modalities using free space layout - MAORIS : MAp Of RIpples SegmentationSep 28 2017How to divide floor plans or navigation maps into a semantic representation, such as rooms and corridors, is an important research question in fields such as human-robot interaction, place categorization, or semantic mapping. While most algorithms focus ... More
Afterglow Light Curves and Broken Power Laws: A Statistical StudyFeb 09 2006In gamma-ray burst research it is quite common to fit the afterglow light curves with a broken power law to interpret the data. We apply this method to a computer simulated population of afterglows and find systematic differences between the known model ... More
Isolated rational curves on K3-fibered Calabi-Yau threefoldsOct 08 1997Jan 24 2001We study each of the 16 types of complete intersection Calabi-Yau threefolds in projective n-space times the projective line, for various n, and prove existence of isolated rational curves of bidegree (d,0) for all positive integers d on a general threefold ... More
The Möbius function of the consecutive pattern posetMar 01 2011An occurrence of a consecutive permutation pattern $p$ in a permutation $\pi$ is a segment of consecutive letters of $\pi$ whose values appear in the same order of size as the letters in $p$. The set of all permutations forms a poset with respect to such ... More
An involution on β(1,0)-treesOct 04 2012In [Decompositions and statistics for \beta(1,0)-trees and nonseparable permutations, Advances Appl. Math. 42 (2009) 313--328] we introduced an involution, h, on \beta(1,0)-trees. We neglected, however, to prove that h indeed is an involution. In this ... More
Luminosity Functions of Gamma-Ray Burst AfterglowsJul 23 2007Aims: Use the standard fireball model to create virtual populations of gamma-ray burst afterglows and study their luminosity functions. Methods: We randomly vary the parameters of the standard fireball model to create virtual populations of afterglows. ... More
Energy Injection in GRB Afterglow ModelsMay 11 2006We extend the standard fireball model, widely used to interpret gamma-ray burst (GRB) afterglow light curves, to include energy injections, and apply the model to the afterglow light curves of GRB 990510, GRB 000301C and GRB 010222. We show that discrete ... More
Host Galaxies of Gamma-Ray Bursts and their Cosmological EvolutionJul 16 2004We use numerical simulations of large scale structure formation to explore the cosmological properties of Gamma-Ray Burst (GRB) host galaxies. Among the different sub-populations found in the simulations, we identify the host galaxies as the most efficient ... More
On the topology of the permutation pattern posetMay 23 2013Feb 17 2015The set of all permutations, ordered by pattern containment, forms a poset. This paper presents the first explicit major results on the topology of intervals in this poset. We show that almost all (open) intervals in this poset have a disconnected subinterval ... More
Tuning metal-insulator transitions in epitaxial V$_2$O$_3$ thin filmsJan 22 2018Apr 03 2018We present a study of the synthesis of epitaxial V$_2$O$_3$ films on $c$-plane Al$_2$O$_3$ substrates by reactive dc-magnetron sputtering. The results reveal a temperature window, at substantially lower values than previously reported, wherein epitaxial ... More
Criticality of compact and noncompact quantum dissipative $Z_4$ models in $(1+1)$ dimensionsMay 04 2011May 12 2011Using large-scale Monte Carlo computations, we study two versions of a $(1+1)D$ $Z_4$-symmetric model with Ohmic bond dissipation. In one of these versions, the variables are restricted to the interval $[0,2\pi>$, while the domain is unrestricted in the ... More
The Abelian sandpile model on Ferrers graphs -- A classification of recurrent configurationsSep 20 2018Jun 26 2019We classify all recurrent configurations of the Abelian sandpile model (ASM) on Ferrers graphs. The classification is in terms of decorations of EW-tableaux, which undecorated are in bijection with the minimal recurrent configurations. We introduce decorated ... More
Improving power of genetic association studies by extreme phenotype sampling: a review and some new resultsJan 05 2017Extreme phenotype sampling is a selective genotyping design for genetic association studies where only individuals with extreme values of a continuous trait are genotyped for a set of genetic variants. Under financial or other limitations, this design ... More
Prospects for laser-driven ion acceleration through controlled displacement of electrons by standing wavesJan 19 2018During the interaction of intense femtosecond laser pulses with various targets, the natural mechanisms of laser energy transformation inherently lack temporal control and thus commonly do not provide opportunities for a controlled generation of a well-collimated, ... More
Bayesian inference for a principal stratum estimand to assess the treatment effect in a subgroup characterized by post-randomization eventsSep 11 2018The treatment effect in a specific subgroup is often of interest in randomized clinical trials. When the subgroup is characterized by the absence of certain post-randomization events, a naive analysis on the subset of patients without these events may ... More
Bistability phenomena in one-dimensional polariton wiresJun 10 2011Mar 23 2013We investigate the phenomena of bistability and domain wall propagation in polaritonic systems with dissipation provided by the interaction with incoherent phonon bath. The results on the temperature dependence of the polariton bistability behavior and ... More
Convergence of Limited Communications Gradient MethodsMar 01 2016Oct 23 2017Distributed optimization increasingly plays a central role in economical and sustainable operation of cyber-physical systems. Nevertheless, the complete potential of the technology has not yet been fully exploited in practice due to communication limitations ... More
SLAM auto-complete: completing a robot map using an emergency mapFeb 16 2017Nov 08 2017In search and rescue missions, time is an important factor; fast navigation and quickly acquiring situation awareness might be matters of life and death. Hence, the use of robots in such scenarios has been restricted by the time needed to explore and ... More
Sparse Partially Collapsed MCMC for Parallel Inference in Topic ModelsJun 11 2015Aug 15 2017Topic models, and more specifically the class of Latent Dirichlet Allocation (LDA), are widely used for probabilistic modeling of text. MCMC sampling from the posterior distribution is typically performed using a collapsed Gibbs sampler. We propose a ... More
On the lateral instability analysis of MEMS comb-drive electrostatic transducersSep 26 2017This paper investigates the lateral pull-in effect of an in-plane overlap-varying transducer. The instability is induced by the translational and rotational displacements. Based on the principle of virtual work, the equilibrium conditions of force and ... More
Theoretical analysis of electrostatic energy harvester configured as Bennet's doubler based on Q-V cyclesSep 25 2017This paper presents theoretical analysis of a MEMS electrostatic energy harvester configured as the Bennet's doubler. Steady-state operation of the doubler circuit can be approximated by a right-angled trapezoid Q-V cycle. A similarity between voltage ... More
Assumption Commitment Types for Resource Management in Virtually Timed AmbientsJun 22 2018This paper introduces a type system for resource management in the context of nested virtualization. With nested virtualization, virtual machines compete with other processes for the resources of their host environment in order to provision their own ... More
Modeling Deployment Decisions for Elastic Services with ABSOct 26 2016The use of cloud technology can offer significant savings for the deployment of services, provided that the service is able to make efficient use of the available virtual resources to meet service-level requirements. To avoid software designs that scale ... More
Analysis of MEMS electrostatic energy harvesters electrically configured as voltage multipliersSep 26 2017This paper presents the analysis of an efficient alternative interface circuit for MEMS electrostatic energy harvesters. It is entirely composed by diodes and capacitors. Based on modeling and simulation, the anti-phase gap-closing structure is investigated. ... More
Sparse Partially Collapsed MCMC for Parallel Inference in Topic ModelsJun 11 2015Oct 19 2016Topic models are widely used for probabilistic modeling of text and images. MCMC sampling from the posterior distribution is typically performed using a collapsed Gibbs sampler. We propose a parallel sparse partially collapsed Gibbs sampler and compare ... More
Limits of multipole pluricomplex Green functionsMar 11 2011Sep 07 2011Let $S_\epsilon$ be a set of $N$ points in a bounded hyperconvex domain in $C^n$, all tending to 0 as$\epsilon$ tends to 0. To each set $S_\epsilon$ we associate its vanishing ideal $I_\epsilon$ and the pluricomplex Green function $G_\epsilon$ with poles ... More
Wideband resonant polarizers made with ultra-sparse dielectric nanowire gridsJul 08 2015Polarizers are essential in diverse photonics applications including display [1], microscopy [2], polarimetric astrophysical observation [3], laser machining [4], and quantum information processing [5]. Whereas conventional polarizers based on natural ... More
Bayesian leave-one-out cross-validation for large dataApr 24 2019Model inference, such as model comparison, model checking, and model selection, is an important part of model development. Leave-one-out cross-validation (LOO) is a general approach for assessing the generalizability of a model, but unfortunately, LOO ... More
Functional renormalization group approach to the singlet-triplet transition in quantum dotsOct 02 2012We present a functional renormalization group approach to the zero bias transport properties of a quantum dot with two different orbitals and in presence of Hund's coupling. Tuning the energy separation of the orbital states, the quantum dot can be driven ... More
Spin-orbit coupled cold exciton condensatesApr 12 2012We analyze theoretically the dynamics of degenerate condensate of cold indirect excitons. We account for both linear spin dependent terms arising from spin-orbit interaction of Rashba and Dresselhaus types and non-linear terms transforming a pair of bright ... More
Voltage Control Using Limited CommunicationApr 03 2017Feb 27 2019In electricity distribution networks, the increasing penetration of renewable energy generation necessitates faster and more sophisticated voltage controls. Unfortunately, recent research shows that local voltage control fails in achieving the desired ... More
Benchmark for Complex Answer RetrievalMay 13 2017Retrieving paragraphs to populate a Wikipedia article is a challenging task. The new TREC Complex Answer Retrieval (TREC CAR) track introduces a comprehensive dataset that targets this retrieval scenario. We present early results from a variety of approaches ... More
Convergence of Limited Communications Gradient MethodsMar 01 2016Nov 02 2016Distributed optimization increasingly plays a central role in economical and sustainable operation of cyber-physical systems. Nevertheless, the complete potential of the technology has not yet been fully exploited in practice due to communication limitations ... More
Properties of wideband resonant reflectors under fully conical light incidenceJan 06 2016Applying numerical modeling coupled with experiments, we investigate the properties of wideband resonant reflectors under fully conical light incidence. We show that the wave vectors pertinent to resonant first-order diffraction under fully conical mounting ... More
Density-matrix approach for an interacting polariton systemJan 19 2011Mar 14 2013Using the Lindblad approach we develop a general formalism for theoretical description of a spatially inhomogeneous bosonic system with dissipation provided by the interaction of bosons with a phonon bath. We apply our results to model the dynamics of ... More
Phonon-mediated Josephson oscillations in excitonic and polaritonic condensatesJul 17 2010We analyze theoretically the role of the exciton-phonon interactions in phenomena related to the Josephson effect between two spatially separated exciton and exciton-polariton condensates. We consider the role of the dephasing introduced by phonons in ... More
Tutorial: Effective visual communication for the quantitative scientistMar 22 2019Effective visual communication is a core competency for pharmacometricians, statisticians, and more generally any quantitative scientist. It is essential in every step of a quantitative workflow, from scoping to execution and communicating results and ... More
Polya Urn Latent Dirichlet Allocation: a doubly sparse massively parallel samplerApr 12 2017Aug 03 2018Latent Dirichlet Allocation (LDA) is a topic model widely used in natural language processing and machine learning. Most approaches to training the model rely on iterative algorithms, which makes it difficult to run LDA on big corpora that are best analyzed ... More
Tuning metal-insulator transitions in epitaxial V$_2$O$_3$ thin filmsJan 22 2018We present a study of the synthesis of epitaxial V$_2$O$_3$ films on $c$-plane Al$_2$O$_3$ substrates by reactive dc-magnetron sputtering. The results reveal a temperature window, at substantially lower values than previously reported, wherein epitaxial ... More
Quantum criticality in spin chains with non-ohmic dissipationApr 11 2012Jun 12 2012We investigate the critical behavior of a spin chain coupled to bosonic baths characterized by a spectral density proportional to $\omega^s$, with $s>1$. Varying $s$ changes the effective dimension $d_\text{eff} = d + z$ of the system, where $z$ is the ... More
Turbulent Fragmentation and the Initial Conditions for Star FormationNov 11 2000Super-sonic turbulence fragments molecular clouds (MC) into a very complex density field with density contrasts of several orders of magnitude. A fraction of the gas is locked into dense and gravitationally bound cores, which collapse as proto-stars. ... More
Web worlds, web-colouring matrices, and web-mixing matricesJan 28 2013We introduce a new combinatorial object called a web world that consists of a set of web diagrams. The diagrams of a web world are generalizations of graphs, and each is built on the same underlying graph. Instead of ordinary vertices the diagrams have ... More
Assumption-Commitment Types for Resource Management in Virtually Timed AmbientsJun 22 2018Apr 12 2019This paper introduces a type system for resource management in the context of nested virtualization. With nested virtualization, virtual machines compete with other processes for the resources of their host environment in order to provision their own ... More
EasyInterface: A toolkit for rapid development of GUIs for research prototype toolsFeb 01 2017In this paper we describe EasyInterface, an open-source toolkit for rapid development of web-based graphical user interfaces (GUIs). This toolkit addresses the need of researchers to make their research prototype tools available to the community, and ... More
Lightweight Time Modeling in Timed CreolSep 22 2010Creol is an object-oriented modeling language in which inherently concurrent objects exchange asynchronous method calls. The operational semantics of Creol is written in an actor-based style, formulated in rewriting logic. The operational semantics yields ... More
Permutation graphs and the Abelian sandpile model, tiered trees and non-ambiguous binary treesOct 04 2018A permutation graph is a graph whose edges are given by inversions of a permutation. We study the Abelian sandpile model (ASM) on such graphs. We exhibit a bijection between recurrent configurations of the ASM on permutation graphs and the tiered trees ... More
Quantum criticality in a dissipative (2+1)-dimensional XY model of circulating currents in high-Tc cupratesNov 02 2011We present large-scale Monte Carlo results for the dynamical critical exponent z and the spatio-temporal two-point correlation function of a (2+1)-dimensional quantum XY model with bond dissipation, proposed to describe a quantum critical point in high-Tc ... More
Enumerating (2+2)-free posets by indistinguishable elementsJun 14 2010Apr 05 2011A poset is said to be (2+2)-free if it does not contain an induced subposet that is isomorphic to 2+2, the union of two disjoint 2-element chains. Two elements in a poset are indistinguishable if they have the same strict up-set and the same strict down-set. ... More
Simulation of an Electrostatic Energy Harvester at Large Amplitude Narrow and Wide Band VibrationsMay 07 2008An electrostatic in-plane overlap varying energy harvester is modeled and simulated using a circuit simulator. Both linear and nonlinear models are investigated. The nonlinear model includes mechanical stoppers at the displacement extremes. Large amplitude ... More
Global Quantum Circuit OptimizationJan 02 2013One of the main goals in quantum circuit optimisation is to reduce the number of ancillary qubits and the depth of computation, to obtain robust computation. However, most of known techniques, based on local rewriting rules, for parallelising quantum ... More
Tiered trees, weights, and q-Eulerian numbersFeb 08 2017Feb 04 2019Maxmin trees are labeled trees with the property that each vertex is either a local maximum or a local minimum. Such trees were originally introduced by Postnikov, who gave a formula to count them and different combinatorial interpretations for their ... More
Feature Extraction for Machine Learning Based Crackle Detection in Lung Sounds from a Health SurveyMay 31 2017Dec 23 2017In recent years, many innovative solutions for recording and viewing sounds from a stethoscope have become available. However, to fully utilize such devices, there is a need for an automated approach for detecting abnormal lung sounds, which is better ... More
Optimal Scheduling for Interference Mitigation by Range InformationJun 30 2014Sep 01 2016The multiple access scheduling decides how the channel is shared among the nodes in the network. Typical scheduling algorithms aims at increasing the channel utilization and thereby throughput of the network. This paper describes several algorithms for ... More
Convergence of Limited Communications Gradient MethodsMar 01 2016Distributed control and decision making increasingly play a central role in economical and sustainable operation of cyber-physical systems. Nevertheless, the full potential of the technology has not yet been fully exploited in practice due to communication ... More
Surface acoustic wave resonators in the quantum regimeOct 16 2015We present systematic measurements of the quality factors of surface acoustic wave (SAW) resonators on ST-X quartz in the gigahertz range at a temperature of $10 \, \textrm{mK}$. We demonstrate a internal quality factor $Q_\mathrm{i}$ approaching $0.5$ ... More
Excitation properties of the divacancy in 4H-SiCApr 03 2018Oct 17 2018We investigate the quenching of the photoluminescence (PL) from the divacancy defect in 4H-SiC consisting of a nearest-neighbour silicon and carbon vacancies. The quenching occurs only when the PL is excited below certain photon energies (thresholds), ... More
Synthesis of optimal controls and numerical optimization for the vibration-based energy harvestersAug 29 2016This work is devoted to demonstration of the mathematical analysis on maximizing the output power harvested from vibration energy harvester under a single sinusoidal input with time-dependent amplitude or drive frequency. While most of recent works have ... More