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Articles 1 - 30 of 85
Full-Text Articles in Physical Sciences and Mathematics
Analysis Of Transient Growth In Iterative Learning Control Using Pseudospectra, Douglas A. Bristow, John R. Singler
Analysis Of Transient Growth In Iterative Learning Control Using Pseudospectra, Douglas A. Bristow, John R. Singler
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In this paper we examine the problem of transient growth in Iterative Learning Co ntrol (ILC). Transient growth is generally avoided in design by using robust monotonic convergence (RMC) criteria. However, RMC leads to fundamental performance limitations. We consider the possibility of allowing safe transient growth in ILC algorithms as a means to circumvent these limitations. Here the pseudospectra is used for the first time to study transient growth in ILC. Basic properties of the pseudospectra that are relevant to the ILC problem are presented. Two ILC design problems are considered and examined using pseduospectra. The pseudospectra provides new results …
Approximating Stationary Statistical Properties, Xiaoming Wang
Approximating Stationary Statistical Properties, Xiaoming Wang
Mathematics and Statistics Faculty Research & Creative Works
It is well-known that physical laws for large chaotic dynamical systems are revealed statistically. Many times these statistical properties of the system must be approximated numerically. the main contribution of this manuscript is to provide simple and natural criterions on numerical methods (temporal and spatial discretization) that are able to capture the stationary statistical properties of the underlying dissipative chaotic dynamical systems asymptotically. the result on temporal approximation is a recent finding of the author, and the result on spatial approximation is a new one. Applications to the infinite Prandtl number model for convection and the barotropic quasi-geostrophic model are …
Systematic Analysis Of Double-Ionization Dynamics Based On Four-Body Dalitz Plots, Daniel Fischer, Michael Schulz, Katharina R. Schneider, Marcelo F. Ciappina, Tom Kirchner, Aditya H. Kelkar, S. Hagman, Manfred Grieser, Kai Uwe Kuhnel, Robert Moshammer, Joachim Hermann Ullrich
Systematic Analysis Of Double-Ionization Dynamics Based On Four-Body Dalitz Plots, Daniel Fischer, Michael Schulz, Katharina R. Schneider, Marcelo F. Ciappina, Tom Kirchner, Aditya H. Kelkar, S. Hagman, Manfred Grieser, Kai Uwe Kuhnel, Robert Moshammer, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
We report on an experimental and theoretical systematic study of double ionization of helium by ion impact in terms of four-particle Dalitz plots. Several collision systems covering abroad range of perturbation parameters η (projectile charge to speed ratio) were investigated. With increasing η we observe a systematic trend from features, characteristic to correlated double-ionization mechanisms, to signatures of higher-order processes not requiring electron-electron correlations [the mechanism called "two-step-two projectile-electron interaction" (TS-2)]. The data for the largest η can qualitatively be amazingly well described by a simple model only including the TS-2 mechanism.
(E,2e) Study Of Two-Center Interference Effects In The Ionization Of N₂, Leigh R. Hargreaves, Christopher J. Colyer, Mark A. Stevenson, B. Lohmann, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning
(E,2e) Study Of Two-Center Interference Effects In The Ionization Of N₂, Leigh R. Hargreaves, Christopher J. Colyer, Mark A. Stevenson, B. Lohmann, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning
Physics Faculty Research & Creative Works
A number of previous studies have suggested the possibility of two-center interference effects in the single ionization of diatomic molecules such as H2 and N2. While interference effects have been successfully observed in the ionization of H2, to date evidence for interference in N2 ionization has yet to be conclusively demonstrated. This study presents triply differential cross sections for electron impact ionization of N2, measured using the (e,2e) technique. The data are probed for signatures of two-center interference effects. Evidence for interference manifesting in the cross sections is observed.
Nonlinear Evolution Of Baryon Acoustic Oscillations From Improved Perturbation Theory In Real And Redshift Spaces, Atsushi Taruya, Takahiro Nishimichi, Shun Saito, Takashi Hiramatsu
Nonlinear Evolution Of Baryon Acoustic Oscillations From Improved Perturbation Theory In Real And Redshift Spaces, Atsushi Taruya, Takahiro Nishimichi, Shun Saito, Takashi Hiramatsu
Physics Faculty Research & Creative Works
We study the nonlinear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of renormalized PT, which provides a nonperturbative way to treat the gravitational clustering of large-scale structure, we apply the closure approximation that truncates the infinite series of loop contributions at one-loop order, and obtain a closed set of integral equations for power spectrum and nonlinear propagator. The resultant integral expressions are basically equivalent to those previously derived in the form of evolution equations, and they keep important nonperturbative properties which can dramatically improve …
Four-Body Model For Transfer Excitation, Allison L. Harris, Jerry Peacher, Don H. Madison, James Colgan
Four-Body Model For Transfer Excitation, Allison L. Harris, Jerry Peacher, Don H. Madison, James Colgan
Physics Faculty Research & Creative Works
We present here a four-body model for transfer-excitation collisions, which we call the four-body transfer-excitation (4BTE) model. Each two-body interaction is explicitly included in the 4BTE model, allowing us to study the effects of individual two-body interactions. We apply our model to fully differential cross sections for proton+helium collisions, and study the effect of the incident projectile-atom interaction, the scattered projectile-ion interaction, the projectile-nuclear interaction, and electron correlation within the target atom.
Protein Secondary Structure Prediction Using Parallelized Rule Induction From Coverings, Leong Lee, Cyriac Kandoth, Jennifer Leopold, Ronald L. Frank
Protein Secondary Structure Prediction Using Parallelized Rule Induction From Coverings, Leong Lee, Cyriac Kandoth, Jennifer Leopold, Ronald L. Frank
Computer Science Faculty Research & Creative Works
Protein 3D structure prediction has always been an important research area in bioinformatics. In particular, the prediction of secondary structure has been a well-studied research topic. Despite the recent breakthrough of combining multiple sequence alignment information and artificial intelligence algorithms to predict protein secondary structure, the Q3 accuracy of various computational prediction algorithms rarely has exceeded 75%. In a previous paper [1], this research team presented a rule-based method called RT-RICO (Relaxed Threshold Rule Induction from Coverings) to predict protein secondary structure. The average Q3 accuracy on the sample datasets using RT-RICO was 80.3%, an improvement over comparable computational methods. …
On Transport Protocol Performance Measurement Over 10gbps High Speed Optical Networks, Yixin Wu, Suman Kumar, Seung Jong Park
On Transport Protocol Performance Measurement Over 10gbps High Speed Optical Networks, Yixin Wu, Suman Kumar, Seung Jong Park
Computer Science Faculty Research & Creative Works
With the integration of IP and optical technology, fast optical network (of the order of 10Gbps) has emerged to support international research cooperation such as massive scientific data transfer and next generation Internet related research. Therefore, it is important to analyze the measurement issues to guide the high-speed transport protocol research for high-speed optical network of the order of 10Gbps. The objectives of this paper are as follows: i) determine the suitability of TCP parameters such as Jumbo Frame size, TCP sender and receiver buffer sizes; ii) evaluate TCP performance measurement tools and emulation tools over 10Gbps high speed optical …
Search For Gravitational-Wave Bursts In The First Year Of The Fifth Ligo Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational-Wave Bursts In The First Year Of The Fifth Ligo Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present the results obtained from an all-sky search for gravitational-wave (GW) bursts in the 64-2000 Hz frequency range in data collected by the LIGO detectors during the first year (November 2005-November 2006) of their fifth science run. The total analyzed live time was 268.6 days. Multiple hierarchical data analysis methods were invoked in this search. The overall sensitivity expressed in terms of the root-sum-square (rss) strain amplitude hrss for gravitational-wave bursts with various morphologies was in the range of 6 x 10-22 Hz -1/2 to a few x 10-21Hz-1/2. No GW signals were …
Correlated Two-Photon Emission By Transitions Of Dirac-Volkov States In Intense Laser Fields: Qed Predictions, Erik Lotstedt, Ulrich D. Jentschura
Correlated Two-Photon Emission By Transitions Of Dirac-Volkov States In Intense Laser Fields: Qed Predictions, Erik Lotstedt, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
In an intense laser field, an electron may decay by emitting a pair of photons. The two photons emitted during the process, which can be interpreted as a laser-dressed double Compton scattering, remain entangled in a quantifiable way: namely, the so-called concurrence of the photon polarizations gives a gauge-invariant measure of the correlation of the hard gamma rays. We calculate the differential rate and concurrence for a backscattering setup of the electron and photon beam, employing Volkov states and propagators for the electron lines, thus accounting nonperturbatively for the electron-laser interaction. The nonperturbative results are shown to differ significantly compared …
Microbial-Induced Heterogeneity In The Acoustic Properties Of Porous Media, Caroline A. Davis, Laura J. Pyrak-Nolte, Estella A. Atekwana, D. Dale, Werkema, Marisa E. Haugen
Microbial-Induced Heterogeneity In The Acoustic Properties Of Porous Media, Caroline A. Davis, Laura J. Pyrak-Nolte, Estella A. Atekwana, D. Dale, Werkema, Marisa E. Haugen
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
It is not known how biofilms affect seismic wave propagation in porous media. Such knowledge is critical for assessing the utility of seismic techniques for imaging biofilm development and their effects in field settings. Acoustic wave data were acquired over a two-dimensional region of a microbial-stimulated sand column and an unstimulated sand column. The acoustic signals from the unstimulated column were relatively uniform over the 2D scan region. The data from the microbial-stimulated column exhibited a high degree of spatial heterogeneity in the acoustic wave amplitude, with some regions exhibiting significant increases in attenuation while others exhibited decreases. Environmental scanning …
Adaptive Distributed Fair Scheduling For Multiple Channels In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda
Adaptive Distributed Fair Scheduling For Multiple Channels In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda
Electrical and Computer Engineering Faculty Research & Creative Works
A novel adaptive and distributed fair scheduling (ADFS) scheme for wireless sensor networks (WSN) in the presence of multiple channels (MC-ADFS) is developed. The proposed MC-ADFS increases available network capacity and focuses on quality-of-service (QoS) issues. when nodes access a shared channel, the proposed MC-ADFS allocates the channel bandwidth proportionally to the packet's weight which indicates the priority of the packet's flow. The packets are dynamically assigned to channels based on the packet weight and current channel utilization. The dynamic assignment of channels is facilitated by use of receiver-based allocation and alternative routes. Moreover, MC-ADFS allows the dynamic allocation of …
Nuclear Form Factor, Validity Of The Equivalent Photon Approximation And Coulomb Corrections To Muon Pair Production In Photon-Nucleus And Nucleus-Nucleus Collisions, Ulrich D. Jentschura, V. G. Serbo
Nuclear Form Factor, Validity Of The Equivalent Photon Approximation And Coulomb Corrections To Muon Pair Production In Photon-Nucleus And Nucleus-Nucleus Collisions, Ulrich D. Jentschura, V. G. Serbo
Physics Faculty Research & Creative Works
We study in detail the influence of the nuclear form factor both on the Born cross section and on the Coulomb corrections to the photo-production of muon pairs off heavy nuclei (γ Z→μ + μ - Z) and in heavy-ion collisions (ZZ→ZZ μ + μ -). Our findings indicate a number of issues which have not been sufficiently described as yet in the literature: (i) the use of a realistic form factor, based on the Fermi charge distribution for the nucleus, is absolutely indispensable for reliable theoretical predictions; (ii) we checked quantitatively that the equivalent photon approximation has a very …
Search For High Frequency Gravitational-Wave Bursts In The First Calendar Year Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For High Frequency Gravitational-Wave Bursts In The First Calendar Year Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present an all-sky search for gravitational waves in the frequency range 1 to 6 kHz during the first calendar year of LIGO's fifth science run. This is the first untriggered LIGO burst analysis to be conducted above 3 kHz. We discuss the unique properties of interferometric data in this regime. 161.3 days of triple-coincident data were analyzed. No gravitational events above threshold were observed and a frequentist upper limit of 5.4 year-1 on the rate of strong gravitational-wave bursts was placed at a 90% confidence level. Implications for specific theoretical models of gravitational-wave emission are also discussed.
Analysis Of Angular Dependence Of Strong-Field Tunneling Ionization For Co₂, Song-Feng Zhao, Cheng Jin, Anh-Thu Le, T. F. Jiang, C. D. Lin
Analysis Of Angular Dependence Of Strong-Field Tunneling Ionization For Co₂, Song-Feng Zhao, Cheng Jin, Anh-Thu Le, T. F. Jiang, C. D. Lin
Physics Faculty Research & Creative Works
We analyzed the discrepancy of the angular dependence of strong-field ionization for CO₂ among the different theoretical calculations and experiments. Using a more accurate ground-state wave function of CO₂ in the asymptotic region, we showed that the accuracy in the earlier tunneling ionization theory of Tong et al. [Phys. Rev. A 66, 033402 (2002)] is much improved. We also concluded that the angular dependence deduced from the experiment of Pavicic [Phys. Rev. Lett. 98, 243001 (2007)] appears to be too narrowly distributed.
Analysis Of Globule Types In Malignant Melanoma, Jin Xu, Kapil Kumar Gupta, William V. Stoecker, Yamini Krishnamurthy, Harold S. Rabinovitz, Austin Bangert, David A. Calcara, Margaret C. Oliviero, Joseph M. Malters, Rhett J. Drugge, R. Joe Stanley, Randy Hays Moss, Mehmed Emre Celebi
Analysis Of Globule Types In Malignant Melanoma, Jin Xu, Kapil Kumar Gupta, William V. Stoecker, Yamini Krishnamurthy, Harold S. Rabinovitz, Austin Bangert, David A. Calcara, Margaret C. Oliviero, Joseph M. Malters, Rhett J. Drugge, R. Joe Stanley, Randy Hays Moss, Mehmed Emre Celebi
Chemistry Faculty Research & Creative Works
Objective: To identify and analyze subtypes of globules based on size, shape, network connectedness, pigmentation, and distribution to determine which globule types and globule distributions are most frequently associated with a diagnosis of malignant melanoma. Design: Retrospective case series of dermoscopy images with globules. Setting: Private dermatology practices. Participants: Patients in dermatology practices. Intervention: Observation only. Main Outcome Measure: Association of globule types with malignant melanoma. Results: The presence of large globules (odds ratio [OR], 5.25) and globules varying in size (4.72) or shape (5.37) had the highest ORs for malignant melanoma among all globule types and combinations studied. Classical …
Reinforcement-Learning-Based Output-Feedback Control Of Nonstrict Nonlinear Discrete-Time Systems With Application To Engine Emission Control, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Reinforcement-Learning-Based Output-Feedback Control Of Nonstrict Nonlinear Discrete-Time Systems With Application To Engine Emission Control, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Electrical and Computer Engineering Faculty Research & Creative Works
A novel reinforcement-learning-based output adaptive neural network (NN) controller, which is also referred to as the adaptive-critic NN controller, is developed to deliver the desired tracking performance for a class of nonlinear discrete-time systems expressed in nonstrict feedback form in the presence of bounded and unknown disturbances. The adaptive-critic NN controller consists of an observer, a critic, and two action NNs. The observer estimates the states and output, and the two action NNs provide virtual and actual control inputs to the nonlinear discrete-time system. The critic approximates a certain strategic utility function, and the action NNs minimize the strategic utility …
Nonlinear Power Spectrum In The Presence Of Massive Neutrinos: Perturbation Theory Approach, Galaxy Bias, And Parameter Forecasts, Shun Saito, Masahiro Takada, Atsushi Taruya
Nonlinear Power Spectrum In The Presence Of Massive Neutrinos: Perturbation Theory Approach, Galaxy Bias, And Parameter Forecasts, Shun Saito, Masahiro Takada, Atsushi Taruya
Physics Faculty Research & Creative Works
Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the high-precision measurements of galaxy power spectrum, when combined with CMB information. In this paper we develop a method to model galaxy power spectrum in the weakly nonlinear regime for a mixed dark matter [cold dark matter (CDM) plus finite-mass neutrinos] model, based on perturbation theory (PT) whose validity is well tested by simulations for a CDM model. In doing this we carefully study various aspects of the nonlinear clustering (nonlinear neutrino perturbations and the higher-order growth functions), and then arrive at a useful approximation allowing …
Reliability Analysis For The Advanced Electric Power Grid: From Cyber Control And Communication To Physical Manifestations Of Failure, Ayman Z. Faza, Sahra Sedigh, Bruce M. Mcmillin
Reliability Analysis For The Advanced Electric Power Grid: From Cyber Control And Communication To Physical Manifestations Of Failure, Ayman Z. Faza, Sahra Sedigh, Bruce M. Mcmillin
Electrical and Computer Engineering Faculty Research & Creative Works
The advanced electric power grid is a cyber-physical system comprised of physical components, such as transmission lines and generators, and a network of embedded systems deployed for their cyber control. The objective of this paper is to qualitatively and quantitatively analyze the reliability of this cyber-physical system. The original contribution of the approach lies in the scope of failures analyzed, which crosses the cyber-physical boundary by investigating physical manifestations of failures in cyber control. As an example of power electronics deployed to enhance and control the operation of the grid, we study Flexible AC Transmission System (FACTS) devices, which are …
Search For Gravitational Wave Ringdowns From Perturbed Black Holes In Ligo S4 Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational Wave Ringdowns From Perturbed Black Holes In Ligo S4 Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
According to general relativity a perturbed black hole will settle to a stationary configuration by the emission of gravitational radiation. Such a perturbation will occur, for example, in the coalescence of a black hole binary, following their inspiral and subsequent merger. At late times the waveform is a superposition of quasinormal modes, which we refer to as the ringdown. The dominant mode is expected to be the fundamental mode, l = m = 2. Since this is a well-known waveform, matched filtering can be implemented to search for this signal using LIGO data. We present a search for gravitational waves …
On The Transition Rate Of The Fe X Red Coronal Line, Gunter Brenner, Jose R. Crespo Lopez-Urrutia, Sven Bernitt, Daniel Fischer, Rainer Ginzel, Kai Uwe Kuhnel, Volkhard Mackel, Paul H. Mokler, Martin C. Simon, Joachim Hermann Ullrich
On The Transition Rate Of The Fe X Red Coronal Line, Gunter Brenner, Jose R. Crespo Lopez-Urrutia, Sven Bernitt, Daniel Fischer, Rainer Ginzel, Kai Uwe Kuhnel, Volkhard Mackel, Paul H. Mokler, Martin C. Simon, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
We present a lifetime measurement of the 3s 23p 5 2 Po 1/2 first excited fine-structure level of the ground state configuration in chlorine-like Fe X, which relaxes to the ground state through a magnetic dipole (M1) transition (the so-called red coronal line) with a wavelength accurately determined to 637.454(1) nm. Moreover, the Zeeman splitting of line was observed. The lifetime of 14.2(2) ms is the most precise one measured in the red wavelength region and agrees well with advanced theoretical predictions and an empirically scaled interpolation based on experimental values from the same isoelectronic sequence.
First Ligo Search For Gravitational Wave Bursts From Cosmic (Super)Strings, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
First Ligo Search For Gravitational Wave Bursts From Cosmic (Super)Strings, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models. Many grand unified theory-scale models (with string tension Gμ/c …
Nonperturbative Treatment Of Double Compton Backscattering In Intense Laser Fields, Erik Lotstedt, Ulrich D. Jentschura
Nonperturbative Treatment Of Double Compton Backscattering In Intense Laser Fields, Erik Lotstedt, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
The emission of a pair of entangled photons by an electron in an intense laser field can be described by two-photon transitions of laser-dressed, relativistic Dirac-Volkov states. In the limit of a small laser field intensity, the two-photon transition amplitude approaches the result predicted by double Compton scattering theory. Multiexchange processes with the laser field, including a large number of exchanged laser photons, cannot be described without the fully relativistic Dirac-Volkov propagator. The nonperturbative treatment significantly alters theoretical predictions for future experiments of this kind. We quantify the degree of polarization correlation of the photons in the final state by …
Einstein@Home Search For Periodic Gravitational Waves In Early S5 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Einstein@Home Search For Periodic Gravitational Waves In Early S5 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The data were searched for quasimonochromatic waves with frequencies f in the range from 50 to 1500 Hz, with a linear frequency drift ḟ (measured at the solar system barycenter) in the range -f/τ < ḟ < 0.1f/τ, for a minimum spin-down age τ of 1000 years for signals below 400 Hz and 8000 years above 400 Hz. The main computational work …
Apparent Weekly And Daily Earthquake Periodicities In The Western United States, Ali Hadi Atef, Kelly H. Liu, Stephen S. Gao
Apparent Weekly And Daily Earthquake Periodicities In The Western United States, Ali Hadi Atef, Kelly H. Liu, Stephen S. Gao
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Analysis of apparent seismicity rate (ASR) using magnitude ≥1 earthquakes located in the western United States confirmed the existence of prominent spectral peaks with periods of 1 and 7 days. The number of recorded earthquakes on Sundays for the duration of 1963-2008 is about 5% higher than that on weekdays, and, more significantly, there is a 9% increase of ASR in the early morning compared with that in the middle of the days. Significant similarities in the spatial distributions of the weekly and daily variations suggest that the two types of variations have the same sources and both originate from …
Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We report on a search for gravitational waves from coalescing compact binaries, of total mass between 2 and 35M⊙, using LIGO observations between November 14, 2006 and May 18, 2007. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass. The LIGO cumulative 90%-confidence rate upper limits of the binary coalescence of neutron stars, black holes and black hole-neutron star systems are 1.4x10-2, 7.3x10-4 and 3.6x10yr-1L10-1, respectively, where L10 is 1010 times the blue solar …
T-Plausibility: Semantic Preserving Text Sanitization, Wei Jiang, Mummoorthy Murugesan, Chris Clifton, Luo Si
T-Plausibility: Semantic Preserving Text Sanitization, Wei Jiang, Mummoorthy Murugesan, Chris Clifton, Luo Si
Computer Science Faculty Research & Creative Works
Text documents play significant roles in decision making and scientific research. Under federal regulations, documents (e.g., pathology records) containing personally identifiable information cannot be shared freely, unless properly sanitized. Generally speaking, document sanitization consists of finding and hiding personally identifiable information. The first task has received much attention from the research community, but the main strategy for the second task has been to simply remove personal identifiers and very sensitive information (e.g., diseases and treatment). It is not hard to see that if important information (e.g., diagnoses and personal medical histories) is completely removed from pathology records, these records are …
Relativistic (Zα)2 Corrections And Leading Quantum Electrodynamic Corrections To The Two-Photon Decay Rate Of Ionic States, Benedikt J. Wundt, Ulrich D. Jentschura
Relativistic (Zα)2 Corrections And Leading Quantum Electrodynamic Corrections To The Two-Photon Decay Rate Of Ionic States, Benedikt J. Wundt, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We calculate the relativistic corrections of relative order (Zα) 2 to the two-photon decay rate of higher excited S and D states in ionic atomic systems, and we also evaluate the leading radiative corrections of relative order α (Zα) 2 ln [(Zα) -2]. We thus complete the theory of the two-photon decay rates up to relative order α3 ln (α). An approach inspired by nonrelativistic quantum electrodynamics is used. We find that the corrections of relative order (Zα) 2 to the two-photon decay are given by the Zitterbewegung, by the spin-orbit coupling and by relativistic corrections to the electron mass, …
Stacked Search For Gravitational Waves From The 2006 Sgr 1900+14 Storm, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Stacked Search For Gravitational Waves From The 2006 Sgr 1900+14 Storm, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present the results of a LIGO search for short-duration gravitational waves (GWs) associated with the 2006 March 29 SGR 1900+14 storm. A new search method is used, "stacking" the GW data around the times of individual soft-gamma bursts in the storm to enhance sensitivity for models in which multiple bursts are accompanied by GW emission. We assume that variation in the time difference between burst electromagnetic emission and potential burst GW emission is small relative to the GW signal duration, and we time-align GW excess power time-frequency tilings containing individual burst triggers to their corresponding electromagnetic emissions. We use …
Light-Particle Single Ionization Of Argon: Influence Of The Projectile Charge Sign, Sebastian Otranto, Ronald E. Olson
Light-Particle Single Ionization Of Argon: Influence Of The Projectile Charge Sign, Sebastian Otranto, Ronald E. Olson
Physics Faculty Research & Creative Works
The ionization of the 3p orbital of argon by incident electrons and positrons is studied by means of the post version of the continuum distorted wave-eikonal initial-state model. Results are presented at both 200 and 500 eV impact energies for conditions amenable to present experiments. Differences in the fully differential cross sections (FDCSs) are analyzed and the influence of the projectile charge sign on the emission dynamics is discussed. The FDCSs are found to display the classic binary plus recoil peak structure at 500 eV, but transition to a more complicated four-lobed structure at the lower impact energy.