Results for "Simon J. Lock"

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The structure of terrestrial bodies: Impact heating, corotation limits and synestiasMay 22 2017During accretion, terrestrial bodies attain a wide range of thermal and rotational states, which are accompanied by significant changes in physical structure (size, shape, pressure and temperature profile, etc.). However, variations in structure have ... More
Tidal evolution of the Moon from a high-obliquity, high-angular-momentum EarthFeb 09 2018In the giant impact hypothesis for lunar origin, the Moon accreted from an equatorial circum-terrestrial disk; however the current lunar orbital inclination of 5 degrees requires a subsequent dynamical process that is still debated. In addition, the giant ... More
The origin of the Moon within a terrestrial synestiaFeb 28 2018The giant impact hypothesis remains the leading theory for lunar origin. However, current models struggle to explain the Moon's composition and isotopic similarity with Earth. Here we present a new lunar origin model. High-energy, high-angular momentum ... More
Scaling graphs of heart rate time series in athletes demonstrate the VLF, LF and HF regionsJul 22 2006Scaling analysis of heart rate time series has emerged as an useful tool for assessment of autonomic cardiac control. We investigate the heart rate time series of ten athletes (five males and five females), by applying detrended fluctuation analysis (DFA). ... More
Joint and individual variation explained (JIVE) for integrated analysis of multiple data typesFeb 20 2011May 28 2013Research in several fields now requires the analysis of data sets in which multiple high-dimensional types of data are available for a common set of objects. In particular, The Cancer Genome Atlas (TCGA) includes data from several diverse genomic technologies ... More
Characterising and recognising game-perfect graphsOct 29 2018Consider a vertex colouring game played on a simple graph with $k$ permissible colours. Two players, a maker and a breaker, take turns to colour an uncoloured vertex such that adjacent vertices receive different colours. The game ends once the graph is ... More
On the Angular Width of Diffractive Beam in Anisotropic MediaDec 15 20112-D diffraction patterns arising in the far-field region were investigated theoretically for the case, when the plane wave with non collinear group and phase velocities is incident on the wide slit in opaque screen with arbitrary orientation. This investigation ... More
Reallocating and Resampling: A Comparison for InferenceAug 07 2017Simulation-based inference plays a major role in modern statistics, and often employs either reallocating (as in a randomization test) or resampling (as in bootstrapping). Reallocating mimics random allocation to treatment groups, while resampling mimics ... More
Characterising and recognising game-perfect graphsOct 29 2018Mar 30 2019Consider a vertex colouring game played on a simple graph with $k$ permissible colours. Two players, a maker and a breaker, take turns to colour an uncoloured vertex such that adjacent vertices receive different colours. The game ends once the graph is ... More
Supervised multiway factorizationSep 11 2016Apr 01 2018We describe a probabilistic PARAFAC/CANDECOMP (CP) factorization for multiway (i.e., tensor) data that incorporates auxiliary covariates, SupCP. SupCP generalizes the supervised singular value decomposition (SupSVD) for vector-valued observations, to ... More
Supervised multiway factorizationSep 11 2016We describe a probabilistic PARAFAC/CANDECOMP (CP) factorization for multiway (i.e., tensor) data that incorporates auxiliary covariates, SupCP. SupCP generalizes the supervised singular value decomposition (SupSVD) for vector-valued observations, to ... More
Superconducting TiN Films Sputtered over a Large Range of Substrate DC BiasAug 14 2014Oct 24 2014We have investigated properties of superconducting titanium nitride (TiN) films that were sputtered over a large range of RF-induced DC bias voltage applied to the substrate. Films grown with the largest bias voltages contained cubic TiN phases with a ... More
Prediction with Dimension Reduction of Multiple Molecular Data Sources for Patient SurvivalApr 07 2017Jul 17 2017Predictive modeling from high-dimensional genomic data is often preceded by a dimension reduction step, such as principal components analysis (PCA). However, the application of PCA is not straightforward for multi-source data, wherein multiple sources ... More
Bayesian nonparametric multiway regression for clustered binomial dataJan 31 2019We introduce a Bayesian nonparametric regression model for data with multiway (tensor) structure, motivated by an application to periodontal disease (PD) data. Our outcome is the number of diseased sites measured over four different tooth types for each ... More
Binding Blocks: building the Universe one nucleus at the timeOct 07 2016We present a new teaching and outreach activity based around the construction of a three-dimensional chart of isotopes using LEGO$^{\copyright}$ bricks. The activity, \emph{Binding Blocks}, demonstrates nuclear and astrophysical processes through a seven-meter ... More
Binding Blocks: building the Universe one nucleus at the timeOct 07 2016Oct 18 2016We present a new teaching and outreach activity based around the construction of a three-dimensional chart of isotopes using LEGO$^{\circledR}$ bricks. The activity, \emph{Binding Blocks}, demonstrates nuclear and astrophysical processes through a seven-meter ... More
Information requirements for enterprise systemsSep 24 2012In this paper, we discuss an approach to system requirements engineering, which is based on using models of the responsibilities assigned to agents in a multi-agency system of systems. The responsibility models serve as a basis for identifying the stakeholders ... More
A smörgåsbord of scalar-flat Kähler ALE surfacesOct 23 2014May 20 2016There are many known examples of scalar-flat K\"ahler ALE surfaces, all of which have group at infinity either cyclic or contained in ${\rm{SU}}(2)$. The main result in this paper shows that for any non-cyclic finite subgroup $\Gamma \subset {\rm{U}}(2)$ ... More
Quotient singularities, eta invariants, and self-dual metricsJan 14 2015There are three main components to this article: (i) A formula for the eta invariant of the signature complex for any finite subgroup of ${\rm{SO}}(4)$ acting freely on $S^3$ is given. An application of this is a non-existence result for Ricci-flat ALE ... More
Curved traversable wormholes in (3+1)-dimensional spacetimeJun 14 2013Dec 08 2013We present the general method of constructing curved traversable wormholes in (3+1)-d spacetime and proceed to thoroughly discuss the physics of a zero tidal force metric without cross-terms. The (3+1)-d solution is compared with the recently studied ... More
Generalized Integrative Principal Component Analysis for Multi-Type Data with Block-Wise Missing StructureAug 07 2018High-dimensional multi-source data are encountered in many fields. Despite recent developments on the integrative dimension reduction of such data, most existing methods cannot easily accommodate data of multiple types (e.g., binary or count-valued). ... More
No-boarding buses: Synchronisation for efficiencyMay 18 2019We investigate a no-boarding policy in a system of $N$ buses serving $M$ bus stops in a loop, which is an entrainment mechanism to keep buses synchronised in a reasonably staggered configuration. Buses always allow alighting, but would disallow boarding ... More
Stabilizer States as a Basis for Density MatricesDec 09 2011We show that the space of density matrices for n-qubit states, considered as a (2^n)^2 dimensional real vector space, has a basis consisting of density matrices of stabilizer states. We describe an application of this result to automated verification ... More
Psychological Frameworks for Persuasive Information and Communications TechnologiesAug 28 2018When developing devices to encourage positive change in users, social psychology can offer useful conceptual resources. This article outlines three major theories from the discipline and discusses their implications for designing persuasive technologies. ... More
Charge and orbital order in frustrated Pb3Mn7O15Jan 13 2012Mar 28 2012The candidate magnetoelectric Pb3Mn7O15 has a structure consisting of 1/3 filled Kagome layers linked by ribbons of edge-sharing octahedra in the stacking direction. Previous reports have indicated a complex hexagonal-orthorhombic structural transition ... More
Slepian functions and their use in signal estimation and spectral analysisSep 29 2009It is a well-known fact that mathematical functions that are timelimited (or spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the finite precision of measurement and computation unavoidably bandlimits our observation and modeling ... More
Programming quantum computers using 3-D puzzles, coffee cups, and doughnutsSep 21 2016The task of programming a quantum computer is just as strange as quantum mechanics itself. But it now looks like a simple 3D puzzle may be the future tool of quantum software engineers.
Streamwise-constant large-scale structures in Couette and Poiseuille flowsApr 24 2019The linear amplification mechanisms leading to streamwise-constant large-scale structures in laminar and turbulent channel flows are considered. A key feature of the analysis is that the Orr--Sommerfeld and Squire operators are each considered separately. ... More
Bayesian Genome- and Epigenome-wide Association Studies with Gene Level DependenceApr 29 2016High-throughput genetic and epigenetic data are often screened for associations with an observed phenotype. For example, one may wish to test hundreds of thousands of genetic variants, or DNA methylation sites, for an association with disease status. ... More
Dynamical Casimir effect in curved spacetimeJul 19 2016Jul 05 2017A boundary undergoing relativistic motion can create particles from quantum vacuum fluctuations in a phenomenon known as the dynamical Casimir effect. We examine the creation of particles, and more generally the transformation of quantum field states, ... More
An equivalence of scalar curvatures on Hermitian manifoldsMay 11 2015For a Kahler metric, the Riemannian scalar curvature is equal to twice the Chern scalar curvature. The question we address here is whether this equivalence can hold for a non-Kahler Hermitian metric. For such metrics, if they exist, the Chern scalar ... More
Rerandomization to improve covariate balance in experimentsJul 24 2012Randomized experiments are the "gold standard" for estimating causal effects, yet often in practice, chance imbalances exist in covariate distributions between treatment groups. If covariate data are available before units are exposed to treatments, these ... More
The lowest eigenvalue of Schrödinger operators on compact manifoldsAug 11 2015May 16 2016The lowest eigenvalue of the Schr\"odinger operator $-\Delta+\mathcal{V}$ on a compact Riemannian manifold without boundary is studied. We focus on the particularly subtle case of a sign changing potential with positive average.
Bayesian Consensus ClusteringFeb 28 2013The task of clustering a set of objects based on multiple sources of data arises in several modern applications. We propose an integrative statistical model that permits a separate clustering of the objects for each data source. These separate clusterings ... More
Classical Control of Large-Scale Quantum ComputersMay 20 2014The accelerated development of quantum technology has reached a pivotal point. Early in 2014, several results were published demonstrating that several experimental technologies are now accurate enough to satisfy the requirements of fault-tolerant, error ... More
Two loop Kahler potential in beta-deformed N=4 SYM theoryMay 23 2008Aug 06 2008In N=2 superconformal field theories the Kahler potential is known to be tree level exact. The beta-deformation of N=4 SU(N) SYM reduces the amount of supersymmetry to N=1, allowing for non-trivial, superconformal loop corrections to the Kahler potential. ... More
Contribution to Temporal Fault Tree Analysis without Modularization and Transformation into the State SpaceMay 18 2015Background: Fault tree analysis (FTA) is a well established method for qualitative as well as probabilistic reliability and safety analysis. As a Boolean model it does not support modelling of dynamic effects like sequence dependencies between fault events. ... More
Performing Quantum Computing Experiments in the CloudMay 18 2016Sep 01 2016Quantum computing technology has reached a second renaissance in the past five years. Increased interest from both the private and public sector combined with extraordinary theoretical and experimental progress has solidified this technology as a major ... More
An examination of some characteristics of Kepler Short and Long Cadence DataJan 30 2012A close comparison of Kepler short- and long-cadence data released prior to 2011 Nov 1 has shown some subtle differences that make the short-cadence data superior to their long-cadence counterparts. The inevitable results of a faster sampling rate are ... More
Pulsating stars in binary systems: a reviewNov 30 2018Jan 08 2019Binary systems anchor many of the fundamental relations relied upon in asteroseismology. Masses and radii are rarely constrained better than when measured via orbital dynamics and eclipse depths. Pulsating binaries have much to offer. They are clocks, ... More
An index theorem for anti-self-dual orbifold-cone metricsSep 14 2012Recently, Atiyah and LeBrun proved versions of the Gauss-Bonnet and Hirzebruch signature Theorems for metrics with edge-cone singularities in dimension four, which they applied to obtain an inequality of Hitchin-Thorpe type for Einstein edge-cone metrics. ... More
Dynamical Casimir effect in curved spacetimeJul 19 2016Aug 25 2016A boundary undergoing relativistic motion can create particles from quantum vacuum fluctuations in a phenomenon known as the dynamical Casimir effect. We examine the creation of particles, and more generally the transformation of quantum field states, ... More
Relativistic quantum clocksSep 29 2016The conflict between quantum theory and the theory of relativity is exemplified in their treatment of time. We examine the ways in which their conceptions differ, and describe a semiclassical clock model combining elements of both theories. The results ... More
On Kähler conformal compactifications of $U(n)$-invariant ALE spacesMay 19 2014Sep 10 2015We prove that a certain class of ALE spaces always has a Kahler conformal compactification, and moreover provide explicit formulas for the conformal factor and the Kahler potential of said compactification. We then apply this to give a new and simple ... More
The potential for super-Nyquist asteroseismology with TESSAug 11 2015The perfect 30-min cadence of the full-frame images from the Transiting Exoplanet Survey Satellite (TESS) will impose a hard Nyquist limit of 24 d$^{-1}$ ($\approx 278$ $\mu$Hz). This will be problematic for asteroseismology of stars with oscillation ... More
Coevality in Young Eclipsing BinariesApr 29 2017The ages of the components in very short period pre-main sequence (PMS) binaries are essential to an understanding of their formation. We considered a sample of 7 PMS eclipsing binaries (EBs) with ages 1 to 6.3 MY and component masses 0.2 to 1.4 Msun ... More
Anti-self-dual orbifolds with cyclic quotient singularitiesMay 17 2012An index theorem for the anti-self-dual deformation complex on anti-self-dual orbifolds with cyclic quotient singularities is proved. We present two applications of this theorem. The first is to compute the dimension of the deformation space of the Calderbank-Singer ... More
A Modification of the Sarkar-Wang Algorithm and an Analysis of its Computational ComplexityNov 28 2007Jan 31 2008The Sarkar-Wang algorithm computes the hat version of the Heegaard Floer homology of a closed oriented three manifold. This paper analyzes the computational complexity of the Sarkar-Wang algorithm; then the algorithm is modified to obtain a better bound. ... More
Helicalised fractalsJun 19 2013Feb 14 2015We formulate the helicaliser, which replaces a given smooth curve by another curve that winds around it. In our analysis, we relate this formulation to the geometrical properties of the self-similar circular fractal (the discrete version of the curved ... More
Shared kernel Bayesian screeningNov 01 2013Feb 17 2016This article concerns testing for equality of distribution between groups. We focus on screening variables with shared distributional features such as common support, modes and patterns of skewness. We propose a Bayesian testing method using kernel mixtures, ... More
Quantum and classical effects in a light-clock falling in Schwarzschild geometryJan 23 2019Jan 24 2019Quantum theory and relativity offer different conceptions of time. To explore the conflict between them, we study a quantum version of the light-clock commonly used to illustrate relativistic time dilation. This semiclassical model combines elements of ... More
On the proportionality of Chern and Riemannian scalar curvaturesSep 01 2015Jun 21 2016On a Kahler manifold there is a clear connection between the complex geometry and underlying Riemannian geometry. In some ways, this can be used to characterize the Kahler condition. While such a link is not so obvious in the non-Kahler setting, one can ... More
Generating of an electric potential on the Moon by Cosmic rays and Solar Wind?Aug 12 2010We investigate the possibility that the Moon develops an electric potential originating from the impinging particles on the Moon from cosmic rays and solar wind. The investigation includes all experimental data of the flux of charged particle for energies ... More
Quantum Information Processing with Nanomechanical QubitsNov 19 2012Feb 15 2013We introduce an approach to quantum information processing where the information is stored in the motional degrees of freedom of nanomechanical devices. The qubits of our approach are formed by the two lowest energy levels of mechanical resonators which ... More
Programming a Topological Quantum ComputerSep 07 2012Topological quantum computing has recently proven itself to be a powerful computational model when constructing viable architectures for large scale computation. The topological model is constructed from the foundation of a error correction code, required ... More
Liveness for VerificationSep 14 2016We explore the use of liveness for interactive program verification for a simple concurrent object language. Our experimental IDE integrates two (formally dual) kinds of continuous testing into the development environment: compatibility-checking, which ... More
Fast simulation of stabilizer circuits using a graph state representationApr 15 2005Jan 03 2006According to the Gottesman-Knill theorem, a class of quantum circuits, namely the so-called stabilizer circuits, can be simulated efficiently on a classical computer. We introduce a new algorithm for this task, which is based on the graph-state formalism. ... More
Further Wolf-Rayet stars in the starburst cluster Westerlund 1Mar 14 2005Mar 21 2005We present new low and intermediate-resolution spectroscopic observations of the Wolf Rayet (WR) star population in the massive starburst cluster Westerlund 1. Finding charts are presented for five new WRs - four WNL and one WCL - raising the current ... More
A newly identified Luminous Blue Variable in the galactic starburst cluster Westerlund 1Dec 02 2003We present observations of the massive transitional star W243 in Westerlund 1. We find an apparent spectral type of early-mid A from our data, in contrast to an earlier classification of B2I, made from data obtained in 1981. The concurrent development ... More
Scalable Similarity Search for Molecular DescriptorsNov 30 2016Similarity search over chemical compound databases is a fundamental task in the discovery and design of novel drug-like molecules. Such databases often encode molecules as non-negative integer vectors, called molecular descriptors, which represent rich ... More
Finite frequency noise in a quantum point contact between helical edge statesAug 03 2012Sep 24 2012We propose and analyze the non-equilibrium finite frequency current-current correlations as a mean to characterize the helical nature of the edge states in a quantum spin hall geometry. We show that the finite frequency noise enables to unambiguously ... More
From Megaparsecs To Milliparsecs: Galaxy Evolution & Supermassive Black Holes with NANOGrav and the ngVLAAug 17 2018The dynamical evolution of supermassive black-hole binary systems is tethered on large scales to the merger rate of massive galaxies, and on small scales to the stellar and gaseous environments of galactic cores. The population of these systems will create ... More
A General Approach to Regularizing Inverse Problems with Regional Data using Slepian WaveletsAug 15 2017Slepian functions are orthogonal function systems that live on subdomains (for example, geographical regions on the Earth's surface, or bandlimited portions of the entire spectrum). They have been firmly established as a useful tool for the synthesis ... More
Fixed Block Compression Boosting in FM-IndexesApr 19 2011A compressed full-text self-index occupies space close to that of the compressed text and simultaneously allows fast pattern matching and random access to the underlying text. Among the best compressed self-indexes, in theory and in practice, are several ... More
D-modules on rigid analytic spaces II: Kashiwara's equivalenceFeb 04 2015We prove that the category of co-admissible D-cap-modules on a smooth rigid analytic space supported on a closed smooth subvariety is naturally equivalent to the category of co-admissible D-cap-modules on the subvariety, and use this result to construct ... More
Overview of Swallow --- A Scalable 480-core System for Investigating the Performance and Energy Efficiency of Many-core Applications and Operating SystemsApr 23 2015We present Swallow, a scalable many-core architecture, with a current configuration of 480 x 32-bit processors. Swallow is an open-source architecture, designed from the ground up to deliver scalable increases in usable computational power to allow experimentation ... More
Compatibility conditions on local and global spectra for $n$-mode Gaussian statesDec 15 2008Compatibility conditions between the (global) spectrum of an $n$-mode Gaussian state and the spectra of the individual modes are presented, making optimal use of beam splitter and (two-mode) squeezing transformations. An unexpected bye-product of our ... More
Gaia's view of the $λ$ Boo star puzzleDec 05 2016The evolutionary status of the chemically peculiar class of $\lambda$ Boo stars has been intensely debated. It is now agreed that the $\lambda$ Boo phenomenon affects A stars of all ages, from star formation to the terminal age main sequence, but the ... More
O VI Observations of the Onset of Convection Zones in Main-Sequence A StarsMay 29 2008If magnetic activity in outer stellar atmospheres is due to an interplay between rotation and subsurface convection, as is generally presumed, then one would not expect to observe indicators of activity in stars with T_eff > 8300 K. Any X-ray or ultraviolet ... More
Scalar and vector Slepian functions, spherical signal estimation and spectral analysisJun 13 2013It is a well-known fact that mathematical functions that are timelimited (or spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the finite precision of measurement and computation unavoidably bandlimits our observation and modeling ... More
Spatiospectral concentration of vector fields on a sphereJun 13 2013We construct spherical vector bases that are bandlimited and spatially concentrated, or, alternatively, spacelimited and spectrally concentrated, suitable for the analysis and representation of real-valued vector fields on the surface of the unit sphere, ... More
Internal and external potential-field estimation from regional vector data at varying satellite altitudeApr 24 2017When modeling global satellite data to recover a planetary magnetic or gravitational potential field and evaluate it elsewhere, the method of choice remains their analysis in terms of spherical harmonics. When only regional data are available, or when ... More
Super-Nyquist Asteroseismology with Future Space MissionsNov 26 2018Nov 28 2018We propose a photometric technique for future space missions that overcomes the problem of Nyquist aliases. These aliases result from typically long cadences of observation imposed by telemetry constraints. The proposed method is to introduce a periodic ... More
Trajectory Clustering, Modelling, and Selection with the Focus on Airspace ProtectionMar 30 2016Take-off and landing are the periods of a flight where aircraft are most vulnerable to a ground based rocket attack by terrorists. While aircraft approach and depart from airports on pre-defined flight paths, there is a degree of uncertainty in the trajectory ... More
A hidden population of Wolf-Rayet stars in the massive galactic cluster Westerlund 1Nov 12 2002We report the discovery of a hitherto undetected population of Wolf-Rayet stars in the young galactic open cluster Westerlund 1. Optical spectroscopy of the cluster identified 11 such objects; provisional classification suggests that 6 are nitrogen rich ... More
A Specification Format and a Verification Method of Fault-Tolerant Quantum CircuitsDec 28 2017Quantum computations are expressed in general as quantum circuits, which are specified by ordered lists of quantum gates. The resulting specifications are used during the optimisation and execution of the expressed computations. However, the specification ... More
Deriving the orbital properties of pulsators in binary systems through their light arrival time delaysApr 20 2015We present the latest developments to the phase modulation method for finding binaries among pulsating stars. We demonstrate how the orbital elements of a pulsating binary star can be obtained analytically, that is, without converting time delays to radial ... More
Disentangling Mass and Mixing HierarchiesJun 30 2015Oct 23 2015We present a fully perturbative mechanism that naturally generates mass hierarchies for the Standard Model (SM) fermions in a flavor-blind sector. The dynamics generating the mass hierarchies can therefore be independent from the source of flavor violation, ... More
Potential-field estimation from satellite data using scalar and vector Slepian functionsJun 27 2013In the last few decades a series of increasingly sophisticated satellite missions has brought us gravity and magnetometry data of ever improving quality. To make optimal use of this rich source of information on the structure of Earth and other celestial ... More
Effective three-body interactions via photon-assisted tunneling in an optical latticeNov 07 2013We present a simple, experimentally realizable method to make coherent three-body interactions dominate the physics of an ultracold lattice gas. Our scheme employs either lattice modulation or laser-induced tunneling to reduce or turn off two-body interactions ... More
Moebius energy of thick knotsAug 30 2001The Moebius energy of a knot is an energy functional for smooth curves based on an idea of self-repelling. If a knot has a thick tubular neighborhood, we would intuitively expect the energy to be low. In this paper, we give explicit bounds for energy ... More
Strategies to cure numerical shock instability in HLLEM Riemann solverJun 07 2018The HLLEM scheme is a popular contact and shear preserving approximate Riemann solver for cheap and accurate computation of high speed gasdynamical flows. Unfortunately this scheme is known to be plagued by various forms of numerical shock instability. ... More
D-modules on rigid analytic spaces II: Kashiwara's equivalenceFeb 04 2015Aug 31 2017We prove that the category of coadmissible D-cap-modules on a smooth rigid analytic space supported on a closed smooth subvariety is naturally equivalent to the category of coadmissible D-cap-modules on the subvariety, and use this result to construct ... More
Searching and Indexing Genomic Databases via KernelizationDec 04 2014The rapid advance of DNA sequencing technologies has yielded databases of thousands of genomes. To search and index these databases effectively, it is important that we take advantage of the similarity between those genomes. Several authors have recently ... More
High-Performance Code Generation though Fusion and VectorizationOct 24 2017We present a technique for automatically transforming kernel-based computations in disparate, nested loops into a fused, vectorized form that can reduce intermediate storage needs and lead to improved performance on contemporary hardware. We introduce ... More
Superdirected Beam of the Surface Spin WaveNov 29 2016Visualized diffraction patterns of the surface spin wave excited by arbitrarily oriented linear transducer in tangentially magnetized ferrite film are investigated experimentally in the plane of ferrite film for the case where the transducer length D ... More
Network Extreme Eigenvalue - from Multimodal to Scale-free NetworkJul 13 2011Dec 22 2011The extreme eigenvalues of adjacency matrices are important indicators on the influences of topological structures to collective dynamical behavior of complex networks. Recent findings on the ensemble averageability of the extreme eigenvalue further authenticate ... More
Range Predecessor and Lempel-Ziv ParsingJul 25 2015The Lempel-Ziv parsing of a string (LZ77 for short) is one of the most important and widely-used algorithmic tools in data compression and string processing. We show that the Lempel-Ziv parsing of a string of length $n$ on an alphabet of size $\sigma$ ... More
Entanglement of Formation for Gaussian StatesAug 12 2008The entanglement of formation (EOF) is computed for arbitrary two-mode Gaussian states. Apart from a conjecture, our analysis rests on two main ingredients. The first is a four-parameter canonical form we develop for the covariance matrix, one of these ... More
Behavioural PrototypesSep 03 2016We sketch a simple language of concurrent objects which explores the design space between type systems and continuous testing. In our language, programs are collections of communicating automata checked automatically for multiparty compatibility. This ... More
An introduction to Fault-tolerant Quantum ComputingAug 15 2015In this paper we provide a basic introduction of the core ideas and theories surrounding fault-tolerant quantum computation. These concepts underly the theoretical framework of large-scale quantum computation and communications and are the driving force ... More
The very rich massive post-main-sequence star population of the open cluster Westerlund 1Aug 23 2002We report the discovery of a population of Wolf-Rayet stars in the young Galactic open cluster Westerlund 1. In an incomplete shallow spectroscopic survey, we find six nitrogen-rich (WN) and five carbon-rich (WC) WR stars. We also confirm the presence ... More
Nonexistence of solutions in $(0,1)$ for K-P-P-type equations for all $d\ge 1$Sep 16 2005Consider the KPP-type equation of the form $\Delta u+f(u)=0$, where $f:[0,1] \to \mathbb R_{+}$ is a concave function. We prove for arbitrary dimensions that there is no solution bounded in $(0,1)$. The significance of this result from the point of view ... More
Modelling the Strategic Alignment of Software Requirements using Goal GraphsNov 27 2012Mar 25 2013This paper builds on existing Goal Oriented Requirements Engineering (GORE) research by presenting a methodology with a supporting tool for analysing and demonstrating the alignment between software requirements and business objectives. Current GORE methodologies ... More
Critical Transitions in Public Opinion: A Case Study of American Presidential ElectionOct 18 2016At the tipping point, it is known that small incident can trigger dramatic societal shift. Getting early-warning signals for such changes are valuable to avoid detrimental outcomes such as riots or collapses of nations. However, it is notoriously hard ... More
Balancing Covariates via Propensity Score WeightingSep 23 2016Covariate balance is crucial for unconfounded descriptive or causal comparisons. However, lack of balance is common in observational studies. This article considers weighting strategies for balancing covariates. We define a general class of weights---the ... More
Balancing Covariates via Propensity Score WeightingSep 23 2016Sep 29 2016Covariate balance is crucial for unconfounded descriptive or causal comparisons. However, lack of balance is common in observational studies. This article considers weighting strategies for balancing covariates. We define a general class of weights---the ... More
Balancing Covariates via Propensity Score WeightingApr 07 2014Nov 15 2016Covariate balance is crucial for unconfounded descriptive or causal comparisons. However, lack of balance is common in observational studies. This article considers weighting strategies for balancing covariates. We define a general class of weights---the ... More
A Fully Convolutional Two-Stream Fusion Network for Interactive Image SegmentationJul 06 2018Oct 02 2018In this paper, we propose a novel fully convolutional two-stream fusion network (FCTSFN) for interactive image segmentation. The proposed network includes two sub-networks: a two-stream late fusion network (TSLFN) that predicts the foreground at a reduced ... More
Spectral Anlysis on Explosive PercolationJan 03 2013We study the spectral properties of the process of explosive percolation. In particular, we explore how the maximum eigenvalue of the adjacency matrix of a network which governs the spreading efficiency evolves as the density of connection increases. ... More