Results for "Dana S. Balser"

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An 8.5 GHz Arecibo survey of Carbon Recombination Lines toward Ultra-compact \HII regions: Physical properties of dense molecular materialJan 29 2005We report here on a survey of carbon recombination lines (RLs) near 8.5 GHz toward 17 ultra-compact \HII regions (\UCHII s). Carbon RLs are detected in 11 directions, indicating the presence of dense photodissociation regions (PDRs) associated with the ... More
Unveiling Extragalactic Star Formation Using Radio Recombination Lines: An EVLA Pilot Study with NGC 253Jun 23 2011Radio recombination lines (RRLs) are powerful, extinction-free diagnostics of the ionized gas in young, star-forming regions. Unfortunately, these lines are difficult to detect in external galaxies. We present the results of EVLA observations of the RRL ... More
The Chemical Evolution of HeliumAug 21 2006We report on measurements of the 4He abundance toward the outer Galaxy HII region S206 with the NRAO Green Bank telescope. Observations of hydrogen and helium radio recombination lines between 8-10 GHz were made toward the peak radio continuum position ... More
Convex rank 1 subsets of Euclidean buildings (of type $A_2$)Oct 30 2006For a Euclidean building $X$ of type $A_{2}$, we classify the 0-dimensional subbuildings $A$ of $\partial_{T}X$ that occur as the asymptotic boundary of closed convex subsets. In particular, we show that triviality of the holonomy of a triple (of points ... More
Limits on Turbulent HI Fluctuations Towards PSR B0329+54 On Scales Between 0.0025 and 12.5 AUJun 02 2005We have measured the HI absorption towards pulsar B0329+54 using the Green Bank Telescope during 18 epochs between 2002 June 30 and 2003 October 10. Three observing epochs consisted of a continuous period of 20 hours each, while fifteen epochs were 1-2 ... More
CO Isotopes in Planetary NebulaeFeb 25 2002Standard stellar evolution theory is inconsistent with the observed isotopic carbon ratio, 12C/13C, in evolved stars. This theory is also inconsistent with the 3He/H abundance ratios observed in Galactic HII regions, when combined with chemical evolution ... More
The Arecibo HII Region Discovery SurveySep 21 2012We report the detection of radio recombination line emission (RRL) using the Arecibo Observatory at X-band (9GHz, 3cm) from 37 previously unknown HII regions in the Galactic zone 66 deg. > l > 31 deg. and |b| < 1 deg. This Arecibo HII Region Discovery ... More
Rate of Convergence for Cardy's FormulaOct 15 2012May 02 2014We show that crossing probabilities in 2D critical site percolation on the triangular lattice in a piecewise analytic Jordan domain converge with power law rate in the mesh size to their limit given by the Cardy-Smirnov formula. We use this result to ... More
Naturality of Rieffel's Morita equivalence for proper actionsOct 15 2008Suppose that a locally compact group $G$ acts freely and properly on the right of a locally compact space $T$. Rieffel proved that if $\alpha$ is an action of $G$ on a $C^*$-algebra $A$ and there is an equivariant embedding of $C_0(T)$ in $M(A)$, then ... More
A Galactic Plane Defined by the Milky Way HII Region DistributionDec 05 2018We develop a framework for a new definition of the Galactic midplane, allowing for tilt (rotation about Galactic azimuth 90deg.), and roll (rotation about Galactic azimuth 0deg.) of the midplane with respect to the current definition. Derivation of the ... More
The Green Bank Telescope Galactic H II Region Discovery SurveyJun 30 2010We discovered a large population of previously unknown Galactic H II regions by using the Green Bank Telescope to detect their hydrogen radio recombination line emission. Since recombination lines are optically thin at 3 cm wavelength, we can detect H ... More
The Green Bank Telescope H II Region Discovery Survey: IV. Helium and Carbon Recombination LinesDec 10 2012The Green Bank Telescope H II Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate H II region targets. Since the ... More
The Green Bank Telescope HII Region Discovery Survey II. The Source CatalogMar 25 2011The Green Bank Telescope HII Region Discovery Survey has doubled the number of known HII regions in the Galactic zone 343deg.\leql\leq67deg. with |b|\leq1deg. We detected 603 discrete hydrogen radio recombination line (RRL) components at 9GHz (3cm) from ... More
3-He in the Milky Way Interstellar Medium: Ionization StructureJun 13 2007The cosmic abundance of the 3-He isotope has important implications for many fields of astrophysics. We are using the 8.665 GHz hyperfine transition of 3-He+ to determine the 3-He/H abundance in Milky Way HII regions and planetary nebulae. This is one ... More
Azimuthal Metallicity Structure in the Milky Way DiskMay 15 2015Elemental abundance patterns in the Galactic disk constrain theories of the formation and evolution of the Milky Way. HII region abundances are the result of billions of years of chemical evolution. We made radio recombination line and continuum measurements ... More
HII Region Ionization of the Interstellar Medium: A Case Study of NGC 7538May 09 2016Using data from the Green Bank Telescope, we analyze the radio continuum (free-free) and radio recombination line (RRL) emission of the compact HII region NGC 7538 (Sharpless 158). We detect extended radio continuum and hydrogen RRL emission beyond the ... More
HII Region Metallicity Distribution in the Milky Way DiskJun 08 2011The distribution of metals in the Galaxy provides important information about galaxy formation and evolution. HII regions are the most luminous objects in the Milky Way at mid-infrared to radio wavelengths and can be seen across the entire Galactic disk. ... More
Radio Recombination Lines in Galactic HII RegionsMar 06 2006We report radio recombination line (RRL) and continuum observations of a sample of 106 Galactic HII regions made with the NRAO 140 Foot radio telescope in Green Bank, WV. We believe this to be the most sensitive RRL survey ever made for a sample this ... More
Radio continuum observations of local star-forming galaxies using the Caltech Continuum Backend on the Green Bank TelescopeNov 11 2013Nov 14 2013We observed radio continuum emission in 27 local (D < 70 Mpc) star-forming galaxies with the Robert C. Byrd Green Bank Telescope between 26 GHz and 40 GHz using the Caltech Continuum Backend. We obtained detections for 22 of these galaxies at all four ... More
Diffuse Ionized Gas in the Milky Way DiskSep 26 2017We analyze the diffuse ionized gas (DIG) in the first Galactic quadrant from l=18deg to 40deg using radio recombination line (RRL) data from the Green Bank Telescope. These data allow us to distinguish DIG emission from HII region emission and thus study ... More
Kinematic Distances: A Monte Carlo MethodFeb 12 2018Distances to high mass star forming regions (HMSFRs) in the Milky Way are a crucial constraint on the structure of the Galaxy. Only kinematic distances are available for a majority of the HMSFRs in the Milky Way. Here we compare the kinematic and parallax ... More
The Detection of 3He+ in a Planetary Nebula Using the VLANov 16 2005We used the VLA to search for 3He+ emission from two Galactic planetary nebulae (PNe): NGC6572 and J320}. Standard stellar models predict that the 3He/H abundance ratios for PNe should be 1-2 orders of magnitude higher than the primordial value (3He/H ... More
Untangling the Recombination Line Emission from HII Regions with Multiple Velocity ComponentsJul 20 2015HII regions are the ionized spheres surrounding high-mass stars. They are ideal targets for tracing Galactic structure because they are predominantly found in spiral arms and have high luminosities at infrared and radio wavelengths. In the Green Bank ... More
The Green Bank Telescope HII Region Discovery Survey: III. Kinematic DistancesMay 18 2012Using the HI Emission/Absorption method, we resolve the kinematic distance ambiguity and derive distances for 149 of 182 (82%) HII regions discovered by the Green Bank Telescope HII Region Discovery Survey (GBT HRDS). The HRDS is an X-band (9GHz, 3cm) ... More
The WISE Catalog of Galactic HII RegionsDec 21 2013Using data from the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite, we made a catalog of over 8000 Galactic HII regions and HII region candidates by searching for their characteristic mid-infrared (MIR) morphology. WISE has sufficient sensitivity ... More
Tracing the Spiral Structure of the Outer Milky Way with Dense Atomic Hydrogen GasJun 30 2017We present a new face-on map of dense neutral atomic hydrogen (HI) gas in the outer Galaxy. Our map has been produced from the Leiden/Argentine/Bonn (LAB) HI 21-cm line all-sky survey by finding intensity maxima along every line of sight and then by projecting ... More
Magnetic Field Strengths in Photodissociation RegionsNov 23 2015We measure carbon radio recombination line (RRL) emission at 5.3 GHz toward four HII regions with the Green Bank Telescope (GBT) to determine the magnetic field strength in the photodissociation region (PDR) that surrounds the ionized gas. Roshi (2007) ... More
Posterior Asymptotic Normality for an Individual Coordinate in High-dimensional Linear RegressionApr 09 2017We consider the sparse high-dimensional linear regression model $Y=Xb+\epsilon$ where $b$ is a sparse vector. For the Bayesian approach to this problem, many authors have considered the behavior of the posterior distribution when, in truth, $Y=X\beta+\epsilon$ ... More
High-Mass Star Formation in the Outer Scutum-Centaurus ArmMay 08 2017The Outer Scutum-Centaurus (OSC) spiral arm is the most distant molecular spiral arm in the Milky Way, but until recently little was known about this structure. Discovered by Dame and Thaddeus (2011), the OSC lies $\sim$15 kpc from the Galactic Center. ... More
A Green Bank Telescope Survey of Large Galactic HII RegionsOct 20 2017As part of our ongoing HII Region Discovery Survey (HRDS), we report the Green Bank Telescope detection of 148 new angularly-large Galactic HII regions in radio recombination line (RRL) emission. Our targets are located at a declination greater than -45deg., ... More
Hydrogen Radio Recombination Line Emission from M51 and NGC628May 29 2018We report the discovery of hydrogen radio recombination line (RRL) emission from two galaxies with star formation rates (SFRs) similar to that of the Milky Way: M51 and NGC628. We use the Green Bank Telescope (GBT) to measure $\sim$15 Hn$\alpha$ recombination ... More
H-, He-like recombination spectra III: $n$-changing collisions in highly-excited Rydberg states and their impact on the radio, IR and optical recombination linesMar 13 2019Mar 18 2019At intermediate to high densities, electron (de-)excitation collisions are the dominant process for populating or depopulating high Rydberg states. In particular, the accurate knowledge of the energy changing ($n$-changing) collisional rates is determinant ... More
H-, He-like recombination spectra III: $n$-changing collisions in highly-excited Rydberg states and their impact on the radio, IR and optical recombination linesMar 13 2019At intermediate to high densities, electron (de-)excitation collisions are the dominant process for populating or depopulating high Rydberg states. In particular, the accurate knowledge of the energy changing ($n$-changing) collisional rates is determinant ... More
Finding Distant Galactic HII RegionsOct 26 2015The WISE Catalog of Galactic HII Regions contains $\sim2000$ HII region candidates lacking ionized gas spectroscopic observations. All candidates have the characteristic HII region mid-infrared morphology of WISE $12\,\,\mu\,m$ emission surrounding $22\,\mu\,m$ ... More
Universal Minimal Flows of Groups of Automorphisms of Uncountable StructuresNov 21 2011It is a well-known fact, that the greatest ambit for a topological group $G$ is the Samuel compactification of $G$ with respect to the right uniformity on $G.$ We apply the original destription by Samuel from 1948 to give a simple computation of the universal ... More
Carbon Monoxide Observations Toward Star Forming Regions in the Outer Scutum-Centaurus Spiral ArmNov 16 2017The Outer Scutum-Centaurus arm (OSC) is the most distant molecular spiral arm known in the Milky Way. The OSC may be the very distant end of the well-known Scutum-Centaurus arm, which stretches from the end of the Galactic bar to the outer Galaxy. At ... More
Science with an ngVLA: Radio Recombination Lines from HII RegionsOct 15 2018The ngVLA will create a Galaxy-wide, volume-limited sample of HII regions; solve some long standing problems in the physics of HII regions; and provide an extinction-free star formation tracer in nearby galaxies.
Torpid Mixing of Local Markov Chains on 3-Colorings of the Discrete TorusJun 14 2012We study local Markov chains for sampling 3-colorings of the discrete torus $T_{L,d}={0,..., L-1}^d$. We show that there is a constant $\rho \approx .22$ such that for all even $L \geq 4$ and $d$ sufficiently large, certain local Markov chains require ... More
Lelek fan from a projective Fraisse limitDec 29 2013May 12 2015We show that a natural quotient of the projective Fraisse limit of a family that consists of finite rooted trees is the Lelek fan. Using this construction, we study properties of the Lelek fan and of its homeomorphism group. We show that the Lelek fan ... More
Non-cancellable elements in type affine $C$ Coxeter groupsOct 06 2009Jan 02 2018Let $(W,S)$ be a Coxeter system and suppose that $w \in W$ is fully commutative (in the sense of Stembridge) and has a reduced expression beginning (respectively, ending) with $s \in S$. If there exists $t\in S$ such that $s$ and $t$ do not commute and ... More
Diagram calculus for a type affine $C$ Temperley--Lieb algebra, IOct 06 2009Jun 24 2015In this paper, we present an infinite dimensional associative diagram algebra that satisfies the relations of the generalized Temperley--Lieb algebra having a basis indexed by the fully commutative elements (in the sense of Stembridge) of the Coxeter ... More
Renault's Equivalence Theorem for Reduced Groupoid C*-algebrasFeb 16 2010Jul 13 2010We use the technology of linking groupoids to show that equivalent groupoids have Morita equivalent reduced C*-algebras. This equivalence is compatible in a natural way in with the Equivalence Theorem for full groupoid C*-algebras.
Detection of Voigt Spectral Line Profiles of Hydrogen Radio Recombination Lines toward Sagittarius B2(N)Feb 19 2010We report the detection of Voigt spectral line profiles of radio recombination lines (RRLs) toward Sagittarius B2(N) with the 100-m Green Bank Telescope (GBT). At radio wavelengths, astronomical spectra are highly populated with RRLs, which serve as ideal ... More
The Southern HII Region Discovery Survey I: The Bright CatalogDec 12 2018The census of Galactic HII regions is vastly incomplete in the Southern sky. We use the Australia Telescope Compact Array (ATCA) to observe 4-10 GHz radio continuum and hydrogen radio recombination line (RRL) emission from candidate HII regions in the ... More
The Southern HII Region Discovery Survey (SHRDS): Pilot SurveyMay 24 2017The Southern HII Region Discovery Survey (SHRDS) is a survey of the third and fourth quadrants of the Galactic plane that will detect radio recombination line and continuum emission at cm-wavelengths from several hundred HII region candidates using the ... More
Wavelet Based Dictionaries for Dimensionality Reduction of ECG SignalsNov 13 2018Dimensionality reduction of ECG signals is considered within the framework of sparse representation. The approach constructs the signal model by selecting elementary components from a redundant dictionary via a greedy strategy. The proposed wavelet dictionaries ... More
The primitive ideals of some étale groupoid C*-algebrasJan 10 2015Consider the Deaconu-Renault groupoid of an action of a finitely generated free abelian monoid by local homeomorphisms of a locally compact Hausdorff space. We catalogue the primitive ideals of the associated groupoid C*-algebra. For a special class of ... More
Structure of crossed products by strictly proper actions on continuous-trace algebrasAug 22 2012We examine the ideal structure of crossed products B\rtimes G where B is a continuous-trace C*-algebra and the induced action of G on the spectrum of B is proper. In particular, we are able to obtain a concrete description of the topology on the spectrum ... More
Convexity theorems for semisimple symmetric spacesJan 06 2014Mar 09 2015We prove a remarkable generalization of a convexity theorem for semisimple symmetric spaces G/H established earlier in 1986 by the second named author. The latter result generalized Kostant's non-linear convexity theorem for the Iwasawa decomposition ... More
A Local Algorithm for Constructing Spanners in Minor-Free GraphsApr 24 2016Constructing a spanning tree of a graph is one of the most basic tasks in graph theory. We consider this problem in the setting of local algorithms: one wants to quickly determine whether a given edge $e$ is in a specific spanning tree, without computing ... More
From Tensor Equations to Numerical Code -- Computer Algebra Tools for Numerical RelativityNov 17 2004In this paper we present our recent work in developing a computer-algebra tool for systems of partial differential equations (PDEs), termed "Kranc". Our work is motivated by the problem of finding solutions of the Einstein equations through numerical ... More
Remarks on Kneip's linear smoothersMay 07 2014We were trying to understand the analysis provided by Kneip (1994, Ordered Linear Smoothers). In particular we wanted to persuade ourselves that his results imply the oracle inequality stated by Tsybakov (2014, Lecture 8). This note contains our reworking ... More
On the number of commutation classes of the longest element in the symmetric groupJan 25 2016Feb 29 2016Using the standard Coxeter presentation for the symmetric group $S_n$, two reduced expressions for the same group element are said to be commutation equivalent if we can obtain one expression from the other by applying a finite sequence of commutations. ... More
Temporal Variability of Lunar Exospheric Helium During January 2012 from LRO/LAMPSep 14 2012We report observations of the lunar helium exosphere made between December 29, 2011, and January 26, 2012, with the Lyman Alpha Mapping Project (LAMP) ultraviolet spectrograph on NASA's Lunar Reconnaissance Orbiter Mission (LRO). The observations were ... More
Towards a classification of CMC-1 Trinoids in hyperbolic space via conjugate surfacesOct 24 2003Oct 01 2004We derive necessary conditions on the parameters of the ends of a CMC-1 trinoid in hyperbolic 3-space $H^{3}$ with symmetry plane by passing to its conjugate minimal surface. Together with Daniel's results, this yields a classification of generic symmetric ... More
Polygons with prescribed Gauss map in Hadamard spaces and Euclidean buildingsDec 02 2004We show that given a stable weighted configuration on the asymptotic boundary of a locally compact Hadamard space, there is a polygon with Gauss map prescribed by the given weighted configuration if the configuration is stable. Moreover, the same result ... More
Axiomatizing Category Theory in Free LogicSep 06 2016Sep 14 2016Starting from a generalization of the standard axioms for a monoid we present a stepwise development of various, mutually equivalent foundational axiom systems for category theory. Our axiom sets have been formalized in the Isabelle/HOL interactive proof ... More
Estimation of convex supports from noisy measurementsApr 26 2018A popular class of problem in statistics deals with estimating the support of a density from $n$ observations drawn at random from a $d$-dimensional distribution. The one-dimensional case reduces to estimating the end points of a univariate density. In ... More
Axiomatizing Category Theory in Free LogicSep 06 2016Oct 12 2018Starting from a generalization of the standard axioms for a monoid we present a stepwise development of various, mutually equivalent foundational axiom systems for category theory. Our axiom sets have been formalized in the Isabelle/HOL interactive proof ... More
Estimating the Coefficients of a Mixture of Two Linear Regressions by Expectation MaximizationApr 26 2017Oct 16 2018We give convergence guarantees for estimating the coefficients of a symmetric mixture of two linear regressions by expectation maximization (EM). In particular, we show that the empirical EM iterates converge to the target parameter vector at the parametric ... More
A robust Bayesian approach to modelling epistemic uncertainty in common-cause failure modelsJan 03 2013In a standard Bayesian approach to the alpha-factor model for common-cause failure, a precise Dirichlet prior distribution models epistemic uncertainty in the alpha-factors. This Dirichlet prior is then updated with observed data to obtain a posterior ... More
A tunable ferroelectric based unreleased RF resonatorMay 15 2019This paper introduces the first tunable ferroelectric capacitor (FeCAP) based unreleased RF MEMS resonator, integrated seamlessly in Texas Instruments' 130nm Ferroelectric RAM (FeRAM) technology. An array of FeCAPs in this complementary metal-oxide-semiconductor ... More
The Electron Temperature Gradient in the Galactic DiskSep 01 2006We derive the electron temperature gradient in the Galactic disk using a sample of HII regions that spans Galactocentric distances 0--17 kpc. The electron temperature was calculated using high precision radio recombination line and continuum observations ... More
Out-Of-Focus Holography at the Green Bank TelescopeDec 10 2006Mar 31 2007We describe phase-retrieval holography measurements of the 100-m diameter Green Bank Telescope using astronomical sources and an astronomical receiver operating at a wavelength of 7 mm. We use the technique with parameterization of the aperture in terms ... More
Rigorous path integrals for supersymmetric quantum mechanics: completing the path integral proof of the index theoremMay 01 2018Many introductory courses in quantum mechanics include Feynman's time-slicing definition of the path integral, with a complete derivation of the propagator in the simplest of cases. However, attempts to generalize this, for instance to non-quadratic potentials, ... More
A Simple Convex Layers AlgorithmFeb 22 2017Mar 16 2017Given a set of $n$ points $P$ in the plane, the first layer $L_1$ of $P$ is formed by the points that appear on $P$'s convex hull. In general, a point belongs to layer $L_i$, if it lies on the convex hull of the set $P \setminus \bigcup_{j<i}\{L_j\}$. ... More
Equivalence and Disintegration Theorems for Fell Bundles and their C*-algebrasJun 05 2008Aug 18 2008We study the C*-algebras of Fell bundles. In particular, we prove the analogue of Renault's disintegration theorem for groupoids. As in the groupoid case, this result is the key step in proving a deep equivalence theorem for the C*-algebras of Fell bundles. ... More
The Dixmier-Douady Class of Groupoid Crossed ProductsSep 11 2002We give a formula for the Dixmier-Douady class of a continuous-trace groupoid crossed product that arises from an action of a locally trivial, proper, principal groupoid on a bundle of elementary $C^*$-algebras that satisfies Fell's condition.
Centers of convex subsets of buildingsOct 20 2004We prove that two dimensional convex subsets of spherical buildings are either buildings or have a center.
Building-like spacesOct 20 2004We study convex subsets of buildings, discuss some structural features and derive several characterizations of buildings.
Renault's Equivalence Theorem for Groupoid Crossed ProductsJul 24 2007Jun 05 2008We provide an exposition and proof of Renault's equivalence theorem for crossed products by locally Hausdorff, locally compact groupoids. Our approach stresses the bundle approach, concrete imprimitivity bimodules and is a preamble to a detailed treatment ... More
Learning to Engage with Interactive Systems: A field StudyApr 14 2019Physical agents that can autonomously generate engaging, life-like behaviour will lead to more responsive and interesting robots and other autonomous systems. Although many advances have been made for one-to-one interactions in well controlled settings, ... More
Composition operators from logarithmic Bloch spaces to weighted Bloch spacesMar 13 2012Nov 24 2012We characterize the analytic self-maps $\phi$ of the unit disk ${\Bbb D}$ in ${\Bbb C}$ that induce continuous composition operators $C_\phi$ from the log-Bloch space $\mathcal{B}^{\log}({\Bbb D})$ to $\mu$-Bloch spaces ${\mathcal B}^\mu({\Bbb D})$ in ... More
Effects and side-effects of plasmonic photothermal therapy in brain tissueFeb 18 2019Heat generated from plasmonic nanoparticles can be utilized in plasmonic photothermal therapy. A combination of near-infrared laser and metallic nanoparticles are compelling for the treatment of brain cancer, due to their efficient light-to-heat conversion ... More
Compact Folded Metasurface SpectrometerJul 29 2018Recent advances in optical metasurfaces enable control of the wavefront, polarization and dispersion of optical waves beyond the capabilities of conventional diffractive optics. An optical design space that is poised to highly benefit from these developments ... More
MEMS-tunable dielectric metasurface lensDec 18 2017Mar 08 2018Varifocal lenses, conventionally implemented by changing the axial distance between multiple optical elements, have a wide range of applications in imaging and optical beam scanning. The use of conventional bulky refractive elements makes these varifocal ... More
Angle-multiplexed metasurfaces: encoding independent wavefronts in a single metasurface under different illumination anglesNov 07 2017The angular response of thin diffractive optical elements is highly correlated. For example, the angles of incidence and diffraction of a grating are locked through the grating momentum determined by the grating period. Other diffractive devices, including ... More
DDSL: Deep Differentiable Simplex Layer for Learning Geometric SignalsJan 30 2019Mar 22 2019We present a Deep Differentiable Simplex Layer (DDSL) for neural networks for geometric deep learning. The DDSL is a differentiable layer compatible with deep neural networks for bridging simplex mesh-based geometry representations (point clouds, line ... More
Coactions and Fell bundlesSep 17 2009We show that if $\AA$ is a Fell bundle over a locally compact group $G$, then there is a natural coaction $\delta$ of $G$ on the Fell-bundle $C^*$-algebra $C^*(G,\AA)$ such that if $\hat{\delta}$ is the dual action of $G$ on the crossed product $C^*(G,\AA) ... More
Veto Interval Graphs and VariationsSep 26 2017Jul 26 2018We introduce a variation of interval graphs, called veto interval (VI) graphs. A VI graph is represented by a set of closed intervals, each containing a point called a veto mark. The edge $ab$ is in the graph if the intervals corresponding to the vertices ... More
Application of Variance-Based Sensitivity Analysis to a Large System Dynamics ModelMar 28 2018Variance-based sensitivity methods can provide insights into large computational models. We present a novel application of sensitivity analysis to the Biomass Scenario Model (BSM) a large and complex system dynamics model of the developing biofuels industry ... More
Fell bundles and imprimitivity theorems: towards a universal generalized fixed point algebraJun 28 2012Nov 29 2012We apply the One-Sided Action Theorem from the first paper in this series to prove that Rieffel's Morita equivalence between the reduced crossed product by a proper saturated action and the generalized fixed-point algebra is a quotient of a Morita equivalence ... More
Fell bundles and imprimitivity theoremsJan 24 2012Jun 25 2012Our goal in this paper and two sequels is to apply the Yamagami-Muhly-Williams equivalence theorem for Fell bundles over groupoids to recover and extend all known imprimitivity theorems involving groups. Here we extend Raeburn's symmetric imprimitivity ... More
Fell bundles and imprimitivity theorems: Mansfield's and Fell's theoremsJul 25 2012Mar 19 2013In the third and latest paper in this series, we recover the imprimitivity theorems of Mansfield and Fell using our technique of Fell bundles over groupoids. Also, we apply the Rieffel Surjection of the first paper in the series to relate our version ... More
Using Game Theory to Study the Evolution of Cultural NormsJun 06 2016Mar 16 2017We discuss how to use evolutionary game theory (EGT) as a framework for studying how cultural dynamics and structural properties can influence the evolution of norms and behaviors within a society. We provide a brief tutorial on how EGT works, and discuss ... More
Interpreting Deep Neural Networks Through Variable ImportanceJan 28 2019While the success of deep neural networks (DNNs) is well-established across a variety of domains, our ability to explain and interpret these methods is limited. Unlike previously proposed local methods which try to explain particular classification decisions, ... More
Summability of solutions of the heat equation with inhomogeneous thermal conductivity in two variablesFeb 27 2009We investigate Gevrey order and 1-summability properties of the formal solution of a general heat equation in two variables. In particular, we give necessary and sufficient conditions for the 1-summability of the solution in a given direction. When restricted ... More
Fixed-point algebras for proper actions and crossed products by homogeneous spacesJul 03 2009We consider a fixed free and proper action of a locally compact group $G$ on a space $T$, and actions $\alpha:G\to \Aut A$ on $C^*$-algebras for which there is an equivariant embedding of $(C_0(T),\rt)$ in $(M(A),\alpha)$. A recent theorem of Rieffel ... More
Synchronization in counter-rotating oscillatorsJun 28 2011An oscillatory system can have clockwise and anticlockwise senses of rotation. We propose a general rule how to obtain counter-rotating oscillators from the definition of a dynamical system and then investigate synchronization. A type of mixed synchronization ... More
Statistical measures and diffusion dynamics in a modified Chua's circuit equation with multi-scroll attractorsMay 18 2011In this paper the focus is set on a modified Chua's circuit model equation with saw-tooth function in place of piece-wise linear function of Chua's circuit displaying multi-scroll chaotic attractors. We study the characteristic properties of first passage ... More
Understanding Norm Change: An Evolutionary Game-Theoretic Approach (Extended Version)Apr 16 2017Human societies around the world interact with each other by developing and maintaining social norms, and it is critically important to understand how such norms emerge and change. In this work, we define an evolutionary game-theoretic model to study ... More
Induction in stages for crossed products of C*-algebras by maximal coactionsFeb 10 2006Apr 03 2007Let B be a C*-algebra with a maximal coaction of a locally compact group G, and let N and H be closed normal subgroups of G with N contained in H. We show that the process Ind_(G/H)^G which uses Mansfield's bimodule to induce representations of the crossed ... More
Detecting falls with X-Factor HMMs when the training data for falls is not availableApr 08 2015Jun 30 2016Identification of falls while performing normal activities of daily living (ADL) is important to ensure personal safety and well-being. However, falling is a short term activity that occurs infrequently. This poses a challenge to traditional classification ... More
Tipping Points for Norm Change in Human CulturesApr 19 2018Jul 02 2018Humans interact with each other on a daily basis by developing and maintaining various social norms and it is critical to form a deeper understanding of how such norms develop, how they change, and how fast they change. In this work, we develop an evolutionary ... More
Naturality of Symmetric Imprimitivity TheoremsMar 21 2011May 30 2011The first imprimitivity theorems identified the representations of groups or dynamical systems which are induced from representations of a subgroup. Symmetric imprimitivity theorems identify pairs of crossed products by different groups which are Morita ... More
Extension problems for representations of crossed-product C*-algebrasFeb 08 2005Nov 09 2006We consider the following problem. Suppose $\alpha$ is an action of a locally compact group $G$ on a $C^*$-algebra $A$, $H$ is a closed subgroup of $G$, and $(\pi,U)$ is a covariant representation of $(A,H,\alpha)$. For which closed subgroups $K$ containing ... More
Experimental Realization of Quantum-Resonance RatchetsJun 06 2007Nov 27 2007Quantum-resonance ratchets associated with the periodically kicked particle are experimentally realized for the first time. This is achieved by using a Bose-Einstein condensate exposed to a pulsed standing light wave and prepared in an initial state differing ... More
Continuous-Trace Groupoid Crossed ProductsJul 11 2002Let $G$ be a second countable, locally compact groupoid with Haar system, and let $\mathcal{A}$ be a bundle of $C^{\ast}$-algebras defined over the unit space of $G$ on which $G$ acts continuously. We determine conditions under which the associated crossed ... More
Toward Single Electron Resolution Phonon Mediated Ionization DetectorsOct 04 2015Experiments seeking to detect rare event interactions such as dark matter or coherent elastic neutrino nucleus scattering are striving for large mass detectors with very low detection threshold. Using Neganov-Luke phonon amplification effect, the Cryogenic ... More
Reprogrammable Graphene-based Metasurface Mirror with Adaptive Focal Point for THz ImagingMar 04 2019Mar 06 2019Recent emergence of metasurfaces has enabled the development of ultra-thin flat optical components through different wavefront shaping techniques at various wavelengths. However, due to the non-adaptive nature of conventional metasurfaces, the focal point ... More