cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On-chip Optical Phase Monitoring in Multi-Transverse-Mode Integrated Silicon-based Optical Processors
Creators: name: Mojaver, Kaveh Rahbardar
name: Liboiron-Ladouceur, Odile
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We design a Multi-Transverse-Mode Optical Processor (MTMOP) on 220 nm thick Silicon Photonics exploiting the first two quasi-transverse electric modes (TE0 and TE1). The objective is to measure the optical phase, required for programming the optical processor, without use of conventional optical phase detection techniques (e.g., coherent detection). In the proposed design, we use a novel but simple building block that converts the optical phase to optical power. Mode TE0 carries the main optical signal while mode TE1 is for programming purposes. The MTMOP operation relies on the fact that the group velocity of TE0 and TE1 propagating through a mode-sensitive phase shifter are different. An unbalanced Mach-Zehnder interferometer (MZI) consists of a mode-sensitive and mode-insensitive phase shifters in the two arms. We set the bias of the phase shifters so that TE0 propagating in the two arms constructively interfere while this will not be the case for TE1. Hence, we detect the phase shift applied to TE0 by measuring the variation in the optical power of TE1. To the best of our knowledge, this design is the first attempt towards realizing a programmable optical processor with fully integrated programming unit exploiting multimode silicon photonics.
Cost-effective photonic super-resolution millimeter-wave joint radar-communication system using self-coherent detection
Creators: name: Bai, Wenlin
name: Li, Peixuan
name: Zou, Xihua
name: Zhong, Ningyuan
name: Pan, Wei
name: Yan, Lianshan
name: Luo, Bin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: A cost-effective millimeter-wave (MMW) joint radar-communication (JRC) system with super resolution is proposed and experimentally demonstrated, using optical heterodyne up-conversion and self-coherent detection down-conversion techniques. The point lies in the designed coherent dual-band constant envelope linear frequency modulation-orthogonal frequency division multiplexing (LFM-OFDM) signal with opposite phase modulation indexes for the JRC system. Then the self-coherent detection, as a simple and low-cost means, is accordingly facilitated for both de-chirping of MMW radar and frequency down-conversion reception of MMW communication, which circumvents the costly high-speed mixers along with MMW local oscillators and more significantly achieves the real-time decomposition of radar and communication information. Furthermore, a super resolution radar range profile is realized through the coherent fusion processing of dual-band JRC signal. In experiments, a dual-band LFM-OFDM JRC signal centered at 54-GHz and 61-GHz is generated. The dual bands are featured with an identical instantaneous bandwidth of 2 GHz and carry an OFDM signal of 1 GBaud, which help to achieve a 6-Gbit/s data rate for communication and a 1.76-cm range resolution for radar.
Cluster structures of the $0^+$ states of $^{13}_Λ{\rm C}$ with the 3$α+Λ$ four-body orthogonality condition model
Creators: name: Wu, Qian
name: Funaki, Yasuro
name: Chen, Xurong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study structures of the $0^+$ states of $^{13}_Λ$C within the framework of $α+α+α+Λ$ four-body orthogonality condition model with the Gaussian expansion method. We obtain five $0^+$ states of $^{13}_Λ$C and compare them with the low-lying four $0^+$ states of $^{12}$C. We find that the $0_1^+$, $0_2^+$ and $0_4^+$ states correspond to the $0_1^+$, $0_2^+$ and $0_4^+$ states of $^{12}$C, respectively. We also find that both the $0_3^+$ and $0_5^+$ states have analogous nature to the $0_3^+$ state of $^{12}$C, where the additional $Λ$ particle couples with $^8$Be cluster and one $α$ cluster, in the $0_3^+$ state of $^{12}$C, respectively. The former is then shown to have an elongated $^9_Λ$Be$(0_1^+) + α$ cluster structure with a higher nodal behaviour for their relative wave function, and the latter have a dilute three-body gas consisting of $2α+^5_Λ$He clusters.
Decreasing ultrafast X-ray pulse durations with saturable absorption and resonant transitions
Creators: name: Cardoch, Sebastian
name: Trost, Fabian
name: Scott, Howard A.
name: Chapman, Henry N.
name: Caleman, Carl
name: Timneanu, Nicusor
Publisher: name: arXiv
Year: 2022
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Saturable absorption is a nonlinear effect where a material's ability to absorb light is frustrated due to a high influx of photons and the creation of electron vacancies. Experimentally induced saturable absorption in copper revealed a reduction in the temporal duration of transmitted X-ray laser pulses, but a complete understanding of this process is still missing. In this computational work, we employ non-local thermodynamic equilibrium plasma simulations to study the interaction of femtosecond X-rays and copper. Following the onset of frustrated absorption, we find that a $K\text{--}M$ resonant transition occurring at highly charged states turns copper opaque again. The changes in absorption generate a transient transparent window responsible for the shortened transmission signal. We also propose using fluorescence induced by the incident beam as an alternative source to achieve shorter X-ray pulses. Intense femtosecond X-ray pulses are valuable to probe the structure and dynamics of biological samples or to reach extreme states of matter. Shortened pulses could be relevant for emerging imaging techniques.
Second order symmetry operators for the massive Dirac equation
Creators: name: Jacobsson, Simon
name: Bäckdahl, Thomas
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 83C60, 58J70, 83-04

description: Employing the covariant language of two-spinors, we find what conditions a curved Lorentzian spacetime must satisfy for existence of a second order symmetry operator for the massive Dirac equation. The conditions are formulated as existence of a set of Killing spinors satisfying a set of covariant linear differential equations. Using these Killing spinors, we then state the most general form of such an operator. Partial results for the zeroth and first order are presented and interpreted as well. Computer algebra tools from the Mathematica package suite xAct were used for the calculations.
description: 16 pages
Internal Conversion Rates from the Extended Thawed Gaussian Approximation: Theory and Validation
Creators: name: Wenzel, Michael
name: Mitric, Roland
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The theoretical prediction of the rates of nonradiative processes in molecules is fundamental to assess their emissive properties. In this context, global harmonic models have been widely used to simulate vibronic spectra as well as internal conversion rates and to predict photoluminescence quantum yields. However, these simplified models suffer from the limitations that are inherent to the harmonic approximation and can have a severe effect on the calculated internal conversion rates. Therefore, the development of more accurate semiclassical methods is highly desirable. Here, we introduce a procedure for the calculation of nonradiative rates in the framework of the time-dependent semi-classical Extended Thawed Gaussian Approximation (ETGA). We systematically investigate the performance of the ETGA method by comparing it to the the adiabatic and vertical harmonic method, which belong to the class of widely used global harmonic models. Its performance is tested in potentials that cannot be treated adequately by global harmonic models, beginning with Morse potentials of varying anharmonicity followed by a double well potential. The calculated radiative and nonradiative internal conversion rates are compared to reference values based on exact quantum dynamics. We find that the ETGA has the capability to predict internal conversion rates in anharmonic systems with an appreciable energy gap, whereas the global harmonic models prove to be insufficient.
Strong gravitational lensing and shadow constraint from M87* of slowly rotating Kerr-like black hole
Creators: name: Kuang, Xiao-Mei
name: Övgün, Ali
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Motivated by (i) more and more interest in strong gravitational lensing by supermassive black holes due to the achievement of EHT observations, (ii) the ongoing popular topic on the possibility of Lorentz symmetry being broken in gravitation and its consequences, we will apply the Einstein bumblebee gravity with Lorentz violation (LV) to the study of strong gravitational lensing effect and the black hole shadow of slowly rotating Kerr-like black hole. In the strong gravitational lensing sector, we first calculate the deflection angel; then treating the slowly rotating Kerr-like black hole as supermassive M87* black hole, we evaluate the gravitational lensing observables (position, separation and magnification) and the time delays between the relativistic images. In the black hole shadow sector, we show the effect of LV parameter on the luminosity of the black hole shadow and photon sphere using the infalling spherical accretion. Moreover, we explore the dependence of various shadow observables on the LV parameter, and then give the possible constraint on the LV parameter by M87* black hole of EHT observations. We find that the LV parameter show significant effect on the strong gravitational lensing effect, the black hole shadow and photon sphere luminosity by accretion material. Our results point out that the future generations of EHT observation may help to distinguish the Einstein bumblebee gravity from GR, and also give a possible constrain on the LV parameter.
description: 22 pages; version accepted for publication in Annals of Physics
Shear viscosity of the $Φ^4$ theory from classical simulation
Creators: name: Homor, M. M.
name: Jakovac, A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Shear viscosity of the classical $Φ^4$ theory is measured using classical microcanonical simulation. To calculate the Kubo formula, we measure the energy-momentum tensor correlation function, and apply the Green-Kubo relation. Being a classical theory, the results depend on the cutoff which should be chosen in the range of the temperature. Comparison with experimentally accessible systems is also performed.
description: 19 pages, 12 figures
Serum N-propeptide of collagen IIA (PIIANP) as a marker of radiographic osteoarthritis burden
Creators: name: Renner, Jordan B.
name: Daghestani, Hikmat N.
name: Gerry Wilson,
name: Jordan, Joanne M.
name: Doherty, Michael
name: Kraus, Virginia B.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: Cartilage homeostasis relies on a balance of catabolism and anabolism of cartilage matrix. Our goal was to evaluate the burden of radiographic osteoarthritis and serum levels of type IIA procollagen amino terminal propeptide (sPIIANP), a biomarker representing type II collagen synthesis, in osteoarthritis.
Single dose primaquine to reduce gametocyte carriage and Plasmodium falciparum transmission in Cambodia: An open-label randomized trial
Creators: name: Sok, Somethy
name: Gosi, Panita
name: Lin, Jessica T
name: Chann, Soklyda
name: Balasubramanian, Sujata
name: Thay, Kheangheng
name: Spring, Michele D
name: Char, Mengchuor
name: Lanteri, Charlotte A
name: Ubalee, Ratawan
name: My, Mok
name: Kuntawunginn, Worachet
name: Ittiverakul, Mali
name: Rahman, Rifat
name: Lon, Chanthap
name: Saunders, David L
name: Meshnick, Steven R
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: Single low dose primaquine (SLD PQ, 0.25mg/kg) is recommended in combination with artemisinin-based combination therapy (ACT) as a gametocytocide to prevent Plasmodium falciparum transmission in areas threatened by artemisinin resistance. To date, no randomized controlled trials have measured primaquine’s effect on infectiousness to Anopheline mosquitoes in Southeast Asia.
On spectra of Koopman, groupoid and quasi-regular representations
Creators: name: Dudko, Artem
name: Grigorchuk, Rostislav
Publisher: name: arXiv
Year: 2015
Subjects: subject: Representation Theory (math.RT)
subject: Group Theory (math.GR)
subject: FOS: Mathematics

description: In this paper we investigate relations between Koopman, groupoid and quasi-regular representations of countable groups. We show that for an ergodic measure class preserving action of a countable group G on a standard Borel space the associated groupoid and quasi-regular representations are weakly equivalent and weakly contained in the Koopman representation. Moreover, if the action is hyperfinite then the Koopman representation is weakly equivalent to the groupoid. As a corollary of our results we obtain a continuum of pairwise disjoint pairwise equivalent irreducible representations of weakly branch groups. As an illustration we calculate spectra of regular, Koopman and groupoid representations associated to the action of the 2-group of intermediate growth constructed by the second author in 1980.
description: Some typos are fixed (including in Theorem 1 and in the proof of Kuhn's Theorem). Several passages not directly relevant to the proofs are removed. Other minor changes are performed
Extension of nano-confined DNA: quantitative comparison between experiment and theory
Creators: name: Iarko, V.
name: Werner, E.
name: Nyberg, L. K.
name: Müller, V.
name: Fritzsche, J.
name: Ambjörnsson, T.
name: Beech, J. P.
name: Tegenfeldt, J. O.
name: Mehlig, K.
name: Westerlund, F.
name: Mehlig, B.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The extension of DNA confined to nanochannels has been studied intensively and in detail. Yet quantitative comparisons between experiments and model calculations are difficult because most theoretical predictions involve undetermined prefactors, and because the model parameters (contour length, Kuhn length, effective width) are difficult to compute reliably, leading to substantial uncertainties. Here we use a recent asymptotically exact theory for the DNA extension in the "extended de Gennes regime" that allows us to compare experimental results with theory. For this purpose we performed new experiments, measuring the mean DNA extension and its standard deviation while varying the channel geometry, dye intercalation ratio, and ionic buffer strength. The experimental results agree very well with theory at high ionic strengths, indicating that the model parameters are reliable. At low ionic strengths the agreement is less good. We discuss possible reasons. Our approach allows, in principle, to measure the Kuhn length and effective width of a single DNA molecule and more generally of semiflexible polymers in solution.
description: Revised version, 6 pages, 2 figures, 1 table, supplementary material
Primordial power spectrum of tensor perturbations in Finsler spacetime
Creators: name: Li, Xin
name: Wang, Sai
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We first investigate the gravitational wave in the flat Finsler spacetime. In the Finslerian universe, we derive the perturbed gravitational field equation with tensor perturbations. The Finslerian background spacetime breaks rotational symmetry and induces parity violation. Then we obtain the modified primordial power spectrum of tensor perturbations. The parity violation feature requires that the anisotropic effect contributes to $TT,TE,EE,BB$ angular correlation coefficients with $l'=l+1$ and $TB,EB$ with $l'=l$. The numerical results show that the anisotropic contributions to angular correlation coefficients depend on $m$, and $TE$ and $ET$ angular correlation coefficients are different.
description: 15 pages, 12 fugures. arXiv admin note: text overlap with arXiv:1502.02256
Flow-oriented perturbation theory
Creators: name: Borinsky, Michael
name: Capatti, Zeno
name: Laenen, Eric
name: Salas-Bernárdez, Alexandre
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We introduce a new diagrammatic approach to perturbative quantum field theory, which we call flow-oriented perturbation theory (FOPT). Within it, Feynman graphs are replaced by strongly connected directed graphs (digraphs). FOPT is a coordinate space analogue of time-ordered perturbation theory and loop-tree duality, but it has the advantage of having combinatorial and canonical Feynman rules, combined with a simplified $i\varepsilon$ dependence of the resulting integrals. Moreover, we introduce a novel digraph-based representation for the S-matrix. The associated integrals involve the Fourier transform of the flow polytope. Due to this polytope's properties, our S-matrix representation exhibits manifest infrared singularity factorization on a per-diagram level. Our findings reveal an interesting interplay between spurious singularities and Fourier transforms of polytopes.
description: 54 pages, many figures; v2: typos corrected and discussion on renormalization added - version to appear in JHEP
Metastable discrete time-crystal resonances in a dissipative central spin system
Creators: name: Cabot, Albert
name: Carollo, Federico
name: Lesanovsky, Igor
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the non-equilibrium behavior of a central spin system where the central spin is periodically reset to its ground state. The quantum mechanical evolution under this effectively dissipative dynamics is described by a discrete-time quantum map. Despite its simplicity this problem shows surprisingly complex dynamical features. In particular, we identify several metastable time-crystal resonances. Here the system does not relax rapidly to a stationary state but undergoes long-lived oscillations with a period that is an integer multiple of the reset period. At these resonances the evolution becomes restricted to a low-dimensional state space within which the system undergoes a periodic motion. Generalizing the theory of metastability in open quantum systems, we develop an effective description for the evolution within this long-lived metastable subspace and show that in the long-time limit a non-equilibrium stationary state is approached. Our study links to timely questions concerning emergent collective behavior in the 'prethermal' stage of a dissipative quantum many-body evolution and may establish an intriguing link to the phenomenon of quantum synchronization.
Searching for Conformity Across Cosmic Time with Local Group and Local Volume Star Formation Histories
Creators: name: Olsen, Charlotte
name: Gawiser, Eric
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Conformity denotes the correlation of properties between pairs of galaxies as a function of separation. Correlations between properties such as star formation rate (SFR), stellar mass, and specific star formation rate (sSFR) have implications for the impact of environment upon galaxy formation and evolution. Conformity between primary galaxies and satellites within the same dark matter halo has been well documented in simulations and observations. However, the existence of conformity at greater distances - known as two-halo conformity - remains uncertain. We investigate whether galaxies in the Local Volume to a distance of 4 Mpc show conformity by examining SFR, sSFR, stellar mass, and quenched fraction as a function of physical separation. Making use of the star formation histories of these galaxies, we then extend this analysis back in time to offer the first probe of conformity inside our past light cone. At the present day, we find that the stellar mass or sSFR of a galaxy correlates with the median SFR of neighboring galaxies at a separation of 2 to 3 Mpc. At a lookback time of 1 Gyr, we find a correlation with the quenched fraction of neighboring galaxies, again at 2 to 3 Mpc separation. These signals of conformity likely arise from the differences between the recent star formation histories of Local Group dwarf galaxies and those outside the Local Group. As current and future missions including JWST, Rubin, and Roman expand the sample of Local Volume galaxies, tests of conformity using star formation histories will provide an important tool for exploring spatio-temporal correlations between galaxies.
description: 14 pages, 10 figures, accepted to ApJ 12/07/2022
Green Mining: A Methodology of Relating Software Change to Power Consumption
Creators: Hindle, Abram
Publisher: name: University of Alberta Library
Year: 2012

Power consumption is becoming more and more important with the increased popularity of smart-phones, tablets and laptops. The threat of reducing a customer's battery-life now hangs over the software developer who asks, “will this next change be the one that causes my software to drain a customer's battery?” One solution is to detect power consumption regressions by measuring the power usage of tests, but this is time-consuming and often noisy. An alternative is to rely on software metrics that allow us to estimate the impact that a change might have on power consumption thus relieving the developer from expensive testing. This paper presents a general methodology for investigating the impact of software change on power consumption, we relate power consumption to software changes, and then investigate the impact of static OO software metrics on power consumption. We demonstrated that software change can effect power consumption using the Firefox web-browser and the Azureus/Vuze BitTorrent client. We found evidence of a potential relationship between some software metrics and power consumption. In conclusion, we explored the effect of software change on power consumption on two projects; and we provide an initial investigation on the impact of software metrics on power consumption.
Do the stars align? Multidimensional analysis of Android's Layered Architecture
Creators: Guana, V.
Rocha, F.P.
Hindle, Abram
Stroulia, E.
Publisher: name: University of Alberta Library
Year: 2012

In this paper we mine the Android bug tracker repository and study the characteristics of the architectural layers of the Android system. We have identified the locality of the Android bugs in the architectural layers of the its infrastructure, and analysed the bug lifetime patterns in each one of them. Additionally, we mined the bug tracker reporters and classified them according to its social centrality in the Android bug tracker community. We report three interesting findings, firstly while some architectural layers have a diverse interaction of people, attracting not only non-central reporters but highly important ones, other layers are mostly captivating for peripheral actors. Second, we exposed that even the bug lifetime is similar across the architectural layers, some of them have higher bug density and differential percentages of unsolved bugs. Finally, comparing the popularity distribution between layers, we have identified one particular layer that is more important to developers and users alike.
Software Bertillonage: Finding the provenance of an entity
Creators: Davies, J.
Godfrey, M.
German, D.
Hindle, Abram
Publisher: name: University of Alberta Library
Year: 2011

Deployed software systems are typically composed of many pieces, not all of which may have been created by the main development team. Often, the provenance of included components -- such as external libraries or cloned source code -- is not clearly stated, and this uncertainty can introduce technical and ethical concerns that make it difficult for system owners and other stakeholders to manage their software assets. In this work, we motivate the need for the recovery of the provenance of software entities by a broad set of techniques that could include signature matching, source code fact extraction, software clone detection, call flow graph matching, string matching, historical analyses, and other techniques. We liken our provenance goals to that of Bertillonage, a simple and approximate forensic analysis technique based on bio-metrics that was developed in 19th century France before the advent of fingerprints. As an example, we have developed a fast, simple, and approximate technique called anchored signature matching for identifying library version information within a given Java application. This technique involves a type of structured signature matching performed against a database of candidates drawn from the Maven2 repository, a 150GB collection of open source Java libraries. An exploratory case study using a proprietary e-commerce Java application illustrates that the approach is both feasible and effective.
Soccer-based promotion of voluntary medical male circumcision: A mixed-methods feasibility study with secondary students in Uganda
Creators: name: Torondel, Belen
name: Francis, Suzanna
name: Gibson, Lorna J.
name: Weiss, Helen A.
name: Rutakumwa, Rwamahe
name: Hershow, Rebecca B.
name: DeCelles, Jeff
name: Ross, David A.
name: Muzira, Philip
name: Miiro, George
name: Nakiyingi-Miiro, Jessica
name: Ssembajjwe, Wilber
name: Musoke, Saidat
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: The Ugandan government is committed to scaling-up proven HIV prevention strategies including safe male circumcision, and innovative strategies are needed to increase circumcision uptake. The aim of this study was to assess the acceptability and feasibility of implementing a soccer-based intervention (“Make The Cut”) among schoolboys in a peri-urban district of Uganda. The intervention was led by trained, recently circumcised “coaches” who facilitated a 60-minute session delivered in schools, including an interactive penalty shoot-out game using metaphors for HIV prevention, sharing of the coaches’ circumcision story, group discussion and ongoing engagement from the coach to facilitate linkage to male circumcision. The study took place in four secondary schools in Entebbe sub-district, Uganda. Acceptability of safe male circumcision was assessed through a cross-sectional quantitative survey. The feasibility of implementing the intervention was assessed by piloting the intervention in one school, modifying it, and implementing the modified version in a second school. Perceptions of the intervention were assessed with in-depth interviews with participants. Of the 210 boys in the cross-sectional survey, 59% reported being circumcised. Findings showed high levels of knowledge and generally favourable perceptions of circumcision. The initial implementation of Make The Cut resulted in 6/58 uncircumcised boys (10.3%) becoming circumcised. Changes made included increasing engagement with parents and improved liaison with schools regarding the timing of the intervention. Following this, uptake improved to 18/69 (26.1%) in the second school. In-depth interviews highlighted the important role of family and peer support and the coach in facilitating the decision to circumcise. This study showed that the modified Make The Cut intervention may be effective to increase uptake of safe male circumcision in this population. However, the intervention is time-intensive, and further work is needed to assess the cost-effectiveness of the intervention conducted at scale.
The Effect of a Noisy Driving Field on a Bistable Polariton System
Creators: name: Abbaspour, H.
name: Sallen, G.
name: Trebaol, S.
name: Morier-Genoud, F.
name: Portella-Oberli, M. T.
name: Deveaud, B.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on the effect of noise on the characteristics of the bistable polariton emission system. The present experiment provides a time resolved access to the polariton emission intensity. We evidence the noise-induced transitions between the two stable states of the bistable polaritons. It is shown that the external noise specifications, intensity and correlation time, can efficiently modify the polariton Kramers time and residence time. We find that there is a threshold noise strength that provokes the collapse of the hysteresis loop. The experimental results are reproduced by numerical simulations using Gross-Pitaeviskii equation driven by a stochastic excitation.
Green Mining: a Methodology of Relating Software Change and Configuration to Power Consumption
Creators: Hindle, Abram
Publisher: name: University of Alberta Library
Year: 2013

Power consumption is becoming more and more important with the increased popularity of smart-phones, tablets and laptops. The threat of reducing a customer’s battery-life now hangs over the software developer, who now asks, “will this next change be the one that causes my software to drain a customer’s battery?” One solution is to detect power consumption regressions by measuring the power usage of tests, but this is time-consuming and often noisy. An alternative is to rely on software metrics that allow us to estimate the impact that a change might have on power consumption thus relieving the developer from expensive testing. This paper presents a general methodology for investigating the impact of software change on power consumption, we relate power consumption to software changes, and then investigate the impact of OO software metrics and churn metrics on power consumption. We demonstrated that software change can effect power consumption using the Firefox web-browser and the Azureus/Vuze BitTorrent client. We found evidence of a potential relationship between some software metrics and power consumption. We also investigate the effect of library versioning on the power consumption of rTorrent. In conclusion, we investigate the effect of software change on power consumption on two projects; and we provide an initial investigation on the impact of software metrics on power consumption.
Data-driven construction of stochastic reduced dynamics encoded with non-Markovian features
Creators: name: She, Zhiyuan
name: Ge, Pei
name: Lei, Huan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: One important problem in constructing the reduced dynamics of molecular systems is the accurate modeling of the non-Markovian behavior arising from the dynamics of unresolved variables. The main complication emerges from the lack of scale separations, where the reduced dynamics generally exhibits pronounced memory and non-white noise terms. We propose a data-driven approach to learn the reduced model of multi-dimensional resolved variables that faithfully retains the non-Markovian dynamics. Different from the common approaches based on the direct construction of the memory function, the present approach seeks a set of non-Markovian features that encode the history of the resolved variables, and establishes a joint learning of the extended Markovian dynamics in terms of both the resolved variables and these features. The training is based on matching the evolution of the correlation functions of the extended variables that can be directly obtained from the ones of the resolved variables. The constructed model essentially approximates the multi-dimensional generalized Langevin equation and ensures numerical stability without empirical treatment. We demonstrate the effectiveness of the method by constructing the reduced models of molecular systems in terms of both one-dimensional and four-dimensional resolved variables.
Visualizing Project Evolution Through Abstract Syntax Tree Analysis
Creators: Feist, M.D.
Santos, E.A.
Watts, I.
Hindle, Abram
Publisher: name: University of Alberta Library
Year: 2016

What is a developer's contribution to a repository? By only counting commits and number of lines changed, existing tools that visualize source code repositories (such as GitHub's graphs) fall short on showing the effective contributions made by each developer. When many commits are viewed as a group, the details are lost. Commit information can be misleading since lines of code give no indication of what was actually being worked on without careful examination of the changed code. Providing a semantic view of this information could provide deeper insights into how software projects evolve since changes to design and features are not clearly visible from line changes alone. We present TypeV: a method for visualizing Java source code repositories. Instead of counting line changes in a commit we extract detailed type information over time by using the differences between abstract syntax trees (ASTs). We are then able to track the additions and deletions of declarations and invocations for each type. Furthermore, we can track each author's type usage over time. Using TypeV, we examine specific cases in well-known repositories where our tool reveals interesting and useful information. We then compare type coverage information from the AST compared to file coverage to determine if unique information is provided by type information.
Improved Answer-Set Programming Encodings for Abstract Argumentation
Creators: name: Gaggl, Sarah A.
name: Manthey, Norbert
name: Ronca, Alessandro
name: Wallner, Johannes P.
name: Woltran, Stefan
Publisher: name: arXiv
Year: 2015
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: The design of efficient solutions for abstract argumentation problems is a crucial step towards advanced argumentation systems. One of the most prominent approaches in the literature is to use Answer-Set Programming (ASP) for this endeavor. In this paper, we present new encodings for three prominent argumentation semantics using the concept of conditional literals in disjunctions as provided by the ASP-system clingo. Our new encodings are not only more succinct than previous versions, but also outperform them on standard benchmarks.
description: To appear in Theory and Practice of Logic Programming (TPLP), Proceedings of ICLP 2015
Social, structural, behavioral and clinical factors influencing retention in Pre-Exposure Prophylaxis (PrEP) care in Mississippi
Creators: name: Johnson, Kendra
name: Chan, Philip A.
name: Nunn, Amy
name: Perez-Brumer, Amaya
name: Beauchamps, Laura
name: Mena, Leandro
name: Bologna, Estefany S.
name: Arnold, Trisha
name: Brinkley-Rubinstein, Lauren
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: Pre-exposure prophylaxis (PrEP) is a biomedical intervention that can reduce rates of HIV transmission when taken once daily by HIV-negative individuals. Little is understood about PrEP uptake and retention in care among the populations most heavily impacted by the HIV epidemic, particularly among young men who have sex with men (YMSM) in the Deep South. Therefore, this study explored the structural, social, behavioral, and clinical factors that affect PrEP use and retention in care among YMSM in Jackson, Mississippi. Thirty MSM who were prescribed PrEP at an outpatient primary care clinic were interviewed and included 23 men who had been retained in PrEP care and seven who had not been retained. The mean age of participants was 26.6 years. Most (23) participants were African American. Major factors affecting PrEP use and retention in PrEP care included 1) structural factors such as cost and access to financial assistance for medications and clinical services; 2) social factors such as stigma and relationship status; 3) behavioral factors including sexual risk behaviors; and 4) clinical factors such as perceived and actual side effects. Many participants also discussed the positive spillover effects of PrEP use and reported that PrEP had a positive impact on their health. Four of the seven individuals who had not been retained re-enrolled in PrEP care after completing their interviews, suggesting that case management and ongoing outreach can enhance retention in PrEP care. Interventions to enhance retention in PrEP care among MSM in the Deep South will be most effective if they address the complex structural, social, clinical, and behavioral factors that influence PrEP uptake and retention in PrEP care.
Photoacoustic ultrasound sources from diffusion-limited aggregates
Creators: name: Patel, Krutik
name: Brubaker, Morgan
name: Kotlerman, Alexander
name: Salazar, Robert
name: Wolf, Eli
name: Weld, David
Publisher: name: arXiv
Year: 2015
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Metallic diffusion-limited aggregate (DLA) films are well-known to exhibit near-perfect broadband optical absorption. We demonstrate that such films also manifest a substantial and relatively material-independent photoacoustic response, as a consequence of their random nanostructure. We theoretically and experimentally analyze photoacoustic phenomena in DLA films, and show that they can be used to create broadband air- coupled acoustic sources. These sources are inexpensive and simple to fabricate, and work into the ultrasonic regime. We illustrate the device possibilities by building and testing an optically-addressed acoustic phased array capable of producing virtually arbitrary acoustic intensity patterns in air.
description: 5 pages, 5 figures
Understanding Android Fragmentation with Topic Analysis of Vendor-Specific Bugs
Creators: Han, D.
Chenlei, Z.
Fan, X.
Hindle, Abram
Wong, K.
Stroulia, E.
Publisher: name: University of Alberta Library
Year: 2012

The fragmentation of the Android ecosystem causes portability and compatibility issues within the entire Android platform, which increases developer workload, delays application deployment, and ultimately disappoints users. This subject is discussed in the press and in scientific publications but it has yet to be systematically examined. The Android bug reports, as submitted by Android-device users, span across operating-system versions and hardware platforms and can provide interesting evidence about the problem. In this paper, we analyze the bug reports related to two popular vendors, HTC and Motorola. First, we manually label the bug reports. Next, we use Labeled-LDA (Latent Dirichlet Allocation) on the labeled data and LDA on the original data, to infer topics. Finally, by examining the relevance of the top 18 bug topics for each vendor's bug reports over time, we classify topics as common or unique (vendor-specific). The latter category constitutes evidence of fragmentation and lack of portability. By comparing Labeled-LDA against LDA, we find that Labeled-LDA produced better, i.e., more feature oriented, topics than LDA. In this paper we find out how fragmentation is manifested within the Android project and we propose a method for tracking fragmentation using feature analysis on project repositories.
Additional file 8 of A scoping review of health literacy in rare disorders: key issues and research directions
Creators: name: Stenberg, Una
name: Westfal, Lydia
name: Dybesland Rosenberger, Andreas
name: Ørstavik, Kristin
name: Flink, Maria
name: Holmen, Heidi
name: Systad, Silje
name: Westermann, Karl Fredrik
name: Velvin, Gry
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Cancer
subject: Science Policy
subject: Mental Health

description: Supplementary Material 8
Formation of hot spots around small primordial black holes
Creators: name: He, Minxi
name: Kohri, Kazunori
name: Mukaida, Kyohei
name: Yamada, Masaki
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this paper, we investigate the thermalization of Hawking radiation from primordial black holes (PBHs) in the early Universe, taking into account the interference effect on thermalization of high energy particles, known as Landau-Pomeranchuk-Migdal (LPM) effect. Small PBHs with masses $ \lesssim 10^9 \, \mathrm{g} $ completely evaporate before the big bang nucleosynthesis (BBN). The Hawking radiation emitted from these PBHs heats up the ambient plasma with temperature lower than the Hawking temperature, which results in a non-trivial temperature profile around the PBHs, namely a hot spot surrounding a PBH with a broken power-law tail. We find that the hot spot has a core with a radius much larger than the black hole horizon and its highest temperature is independent of the initial mass of the PBH such as $2 \times 10^{9} \, {\rm GeV} \times (α/0.1)^{19/3}$, where $α$ generically represents the fine-structure constants. We also briefly discuss the implications of the existence of the hot spot for phenomenology.
description: 20 pages, 4 figures. Coincides with published version
Multifractal Aspects of Software Development
Creators: Hindle, Abram
Godfrey, M.M.
Holt, R.C.
Publisher: name: University of Alberta Library
Year: 2011

Software development is difficult to model, particularly the noisy, non-stationary signals of changes per time unit, extracted from version control systems (VCSs). Currently researchers are utilizing timeseries analysis tools such as ARIMA to model these signals extracted from a project's VCS. Unfortunately current approaches are not very amenable to the underlying power-law distributions of this kind of signal. We propose modeling changes per time unit using multifractal analysis. This analysis can be used when a signal exhibits multi-scale self-similarity, as in the case of complex data drawn from power-law distributions. Specifically we utilize multifractal analysis to demonstrate that software development is multifractal, that is the signal is a fractal composed of multiple fractal dimensions along a range of Hurst exponents. Thus we show that software development has multi-scale self-similarity, that software development is multifractal. We also pose questions that we hope multifractal analysis can answer.
Erasing the Milky Way: new cleaning technique applied to GBT intensity mapping data
Creators: name: Wolz, L.
name: Blake, C.
name: Abdalla, F. B.
name: Anderson, C. M.
name: Chang, T. -C.
name: Li, Y. -C.
name: Masui, K. W.
name: Switzer, E.
name: Pen, U. -L.
name: Voytek, T. C.
name: Yadav, J.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the first application of a new foreground removal pipeline to the current leading HI intensity mapping dataset, obtained by the Green Bank Telescope (GBT). We study the 15hr and 1hr field data of the GBT observations previously presented in Masui et al (2013) and Switzer et al (2013), covering about 41 square degrees at 0.6
description: 14 pages, 11 figures, published in Monthly Notices of the Royal Astronomical Society 2016
Starobinsky-Bel-Robinson gravity
Creators: name: Ketov, Sergei V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A novel superstring-inspired gravitational theory in four spacetime dimensions is proposed as a sum of the modified $(R+αR^2)$ gravity motivated by the Starobinsky inflation and the Bel-Robinson-tensor-squared term motivated by the eleven-dimensional M-theory dimensionally reduced to four dimensions. The proposed Starobinsky-Bel-Robinson action has only two parameters, which makes it suitable for verifiable physical applications in black hole physics, cosmological inflation and Hawking radiation in the early universe.
description: 7 pages, no figures, LaTeX; major revision
Behaviors of Concrete Beam to Column Connections under Static Load Using Finite Element Method
Creators: name: Atthaphon Atichat
Publisher: name: TUENGR Group
Year: 2017
Subjects: ABAQUS
Beam-Column Joint
Reinforce concrete
Structural stiffness
Structural ductility .

description: International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies, 8, 2, 57-67
Sugary drinks taxation, projected consumption and fiscal revenues in Colombia: Evidence from a QUAIDS model
Creators: name: Ng, Shu Wen
name: Bonilla, Ricardo
name: Tovar, Jorge
name: Popkin, Barry M.
name: Caro, Juan Carlos
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: The global shift towards diets high in sugar-sweetened beverages (SSBs) is linked to higher prevalence of obesity, diabetes and most other non-communicable diseases. In Colombia, one out of every two people was overweight or obese by 2010. This study estimates price-elasticities from a Quadratic Almost Ideal Demand System model, using the 2006–2007 Colombian Income and Expenditure survey. The food groups that were jointly considered were: unsweetened unflavored milks; coffee and tea; sugar sweetened beverages (SSBs); sweets and candies (including sugar); dairy products; meats and animal-based products; grains based staples; fruits and vegetables; and condiments and snacks. We take into account the high proportion of households not purchasing specific food and beverage groups (censored data) and endogeneity on both prices (as unit values) and total expenditure. Unhealthy beverages are price-elastic (-1.61 for SSBs) meaning that the change in consumption is proportionally larger with respect to a change in price. Also, there is a high complementarity among SSBs and major food groups (grains, meats and fruits and vegetables). In Colombia, the design of a meaningful tax to influence healthier diets is a next critical step. This study also shows that a tax of 20% on SSBs should prove to be effective, and can yield revenues of about 1% of the Colombian government’s total annual fiscal revenue, which can potentially be directed towards public health promotion and investments.