cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Explicit Diagonalization of Pair Interaction Models
Creators: name: Matsuzawa, Yasumichi
name: Sasaki, Itaru
name: Usami, Kyosuke
Publisher: name: arXiv
Year: 2019
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 81Q10

description: We provide a general method for constructing bosonic Bogoliubov transformations that diagonalize a general class of quadratic Hamiltonians. These Hamiltonians describe the pair interaction models. Bogoliubov transformations are constructed algebraically, and the resulting Hamiltonians become the second quantizations of explicit one-particle Hamiltonians. Moreover, an explicit formula for the ground state energies is given. Our method systematically diagonalizes various models of quantum field theory, including a model of a harmonic oscillator coupled to a Bose field and the Pauli-Fierz models in the dipole approximation.
description: 48 pages
Uncovering axion-like particles in supernova gamma-ray spectra
Creators: name: Calore, Francesca
name: Carenza, Pierluca
name: Eckner, Christopher
name: Giannotti, Maurizio
name: Lucente, Giuseppe
name: Mirizzi, Alessandro
name: Sivo, Francesco
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A future Galactic Supernova (SN) explosion can lead to a gamma-ray signal induced by ultralight Axion-Like Particles (ALPs) thermally produced in the SN core and converted into high-energy photons in the Galactic magnetic field. The detection of such a signal is in the reach of the Large Area Telescope aboard the \emph{Fermi} Gamma-Ray Space Telescope. The observation of gamma-ray emission from a future SN has a sensitivity to $g_{aγ}\gtrsim 4\times 10^{-13}$ GeV$^{-1}$ for a SN at fiducial distance of $10$ kpc and would allow us to reconstruct the ALP-photon coupling within a factor of $\sim2$, mainly due to the uncertainties on the modeling of the Galactic magnetic field.
description: 17 pages, 8 figures. v2: 18 pages, 8 figures. Minor changes to match the published version
FOOD AID IN BANGLADESH: ITS IMPLICATIONS
Creators: name: Bari, A.K. Maksudul
name: Bari, A.K. Maksudul
Publisher: name: Unknown
Year: 1987
Subjects: Research and Development/Tech Change/Emerging Technologies

description: Bangladesh has been continuing as a major recipient of food aid since her independence. This article reviews and analyses the implications of large food aid imports on Bangladesh economy. Available evi dente justifies that food aid has had some adverse effects by keeping the country dependent on food imports and probably by reducing pressure on government to accord high priority for agricultural research and development. The serious adverse effect of food aid came as a pressure from the donors for policy changes and also as political lever. However, there were certain beneficial effects of food aid on balance of payments, government revenues and wheat output growth through developing its taste among the consumers.
Color superconducting quark matter core in the third family of compact stars
Creators: name: Banik, Sarmistha
name: Bandyopadhyay, Debades
Publisher: name: arXiv
Year: 2002
Subjects: subject: Astrophysics (astro-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate first order phase transitions from $β$-equilibrated hadronic matter to color flavor locked quark matter in compact star interior. The hadronic phase including hyperons and Bose-Einstein condensate of $K^-$ mesons is described by the relativistic field theoretical model with density dependent meson-baryon couplings. The early appearance of hyperons and/or Bose-Einstein condensate of $K^-$ mesons delays the onset of phase transition to higher density. In the presence of hyperons and/or $K^-$ condensate, the overall equations of state become softer resulting in smaller maximum masses than the cases without hyperons and $K^-$ condensate. We find that the maximum mass neutron stars may contain a mixed phase core of hyperons, $K^-$ condensate and color superconducting quark matter. Depending on the parameter space, we also observe that there is a stable branch of superdense stars called the third family branch beyond the neutron star branch. Compact stars in the third family branch may contain pure color superconducting core and have radii smaller than those of the neutron star branch. Our results are compared with the recent observations on RX J185635-3754 and the recently measured mass-radius relationship by X-ray Multi Mirror-Newton Observatory.
description: 24 pages, RevTex, 9 figures included; section II shortened, section III elaborated, two new curves in Fig. 9 and acknowledgements added; version to bepublished in Phys. Rev. D
About Algebraic Foundations of Majorana-Oppenheimer Quantum Electrodynamics and de Broglie-Jordan Neutrino Theory of Light
Creators: name: Varlamov, Vadim V.
Publisher: name: arXiv
Year: 2001
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 15A66, 15A90

description: An algebraic description of basic physical fields (neutrino field, electron-positron field and electromagnetic field) is studied. It is sown that the electromagnetic field can be described within a quotient representation of the proper orthochronous Lorentz group. The relation of such a description with Majorana-Oppenheimer quantum electrodynamics and de Broglie-Jordan neutrino theory of light is discussed.
description: 10 pages, LaTeX2e, corrected version, to appear in Annales de la Fondation Louis de Broglie
Comment on "1/f noise in the Bak-Sneppen model"
Creators: name: Davidsen, J.
name: Luethje, N.
Publisher: name: arXiv
Year: 2002
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Contrary to the recently published results by Daerden and Vanderzande [Phys. Rev. E 53, 4723 (1996)], we show that the time correlation function in the random-neighbor version of the Bak-Sneppen model can be well approximated by an exponential giving rise to a 1/f2 power spectrum.
description: 2 pages, 2 figures
title: Interpreting Summer in the Parks in the National Capital Area of the National Park Service
Creators: name: Kane, Brendan J.
Publisher: name: Old Dominion University Libraries
Year: 2021

description: Washington D.C. has witnessed many watershed events throughout the history of the United States of America. One of these events was the Summer in the Parks (SITP) program organized by the National Park Service (NPS) from 1968-1976. Summer in the Parks was a community-based series of events including concerts, park visits, and exhibitions designed to quell racial tensions and promote park usage. Researchers have begun chronicling SITP, but have yet to explore how the story of SITP is conveyed by park interpreters to visitors and subsequently what themes are shared to inform public understanding of the historic relationship between NPS resources in the National Capital Area and individuals identifying as Black, Indigenous, and People of Color (BIPOC). This research sought to understand where and how SITP is interpreted in the National Capital Area, Region 1 (hereafter referred to as the NCA), what methods are used to produce interpretive programs for SITP, and NPS employees’ perspectives on the role of the SITP story in the NCA. In-depth interviews with 5 interpretive program managers were conducted to understand their experience interpreting SITP and how they perceive SITP relates to the larger community engagement narrative woven through the Washington D.C, the NCA, and the NPS. Specifically, we were interested in how interpreters made sense of SITP and its relationship with the current narrative surrounding the engagement of BIPOC visitors at NPS units. Interviews were then analyzed using Interpretive Phenomenological Analysis to better understand how interpreters make sense of and perceive the opportunities they provide visitors to engage with this history. Results will inform future SITP interpretation, as well as how SITP is situated within the goal of the Urban Agenda, created by the NPS to focus on providing opportunities for the many diverse communities in urban centers and “nurture a Culture of Collaboration” (NPS, 2017). Finally, this work aims to further the goal of individuals of all cultures, races, and ethnicities to feeling comfortable, accepted, and represented in NCA units.
Cont-Bouchaud percolation model including Tobin tax
Creators: name: Ehrenstein, Gudrun
Publisher: name: arXiv
Year: 2002
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Statistical Finance (q-fin.ST)
subject: FOS: Physical sciences
subject: FOS: Economics and business

description: The Tobin tax is an often discussed method to tame speculation and get a source of income. The discussion is especially heated when the financial markets are in crisis. In this article we refer to foreign exchange markets. The Tobin tax should be a small international tax affecting all currency transactions and thus consequently reducing the destabilizing speculations. In this way this tax should take over a control function. By including Tobin tax in the microscopic model of Cont and Bouchaud one finds that Tobin tax could be the right method to control foreign exchange operations and get a good source of income
description: Expanded for of paper to be published in Int. J. Mod. Phys. C 13 (2002)
Wrapyfi: A Python Wrapper for Integrating Robots, Sensors, and Applications across Multiple Middleware
Creators: name: Abawi, Fares
name: Allgeuer, Philipp
name: Fu, Di
name: Wermter, Stefan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Message oriented and robotics middleware play an important role in facilitating robot control, abstracting complex functionality, and unifying communication patterns between sensors and devices. However, using multiple middleware frameworks presents a challenge in integrating different robots within a single system. To address this challenge, we present Wrapyfi, a Python wrapper supporting multiple message oriented and robotics middleware, including ZeroMQ, YARP, ROS, and ROS 2. Wrapyfi also provides plugins for exchanging deep learning framework data, without additional encoding or preprocessing steps. Using Wrapyfi eases the development of scripts that run on multiple machines, thereby enabling cross-platform communication and workload distribution. We finally present the three communication schemes that form the cornerstone of Wrapyfi's communication model, along with examples that demonstrate their applicability.
description: Accepted at HRI 2024
Estimation of the number of single-photon emitters for multiple fluorophores with the same spectral signature
Creators: name: Li, Wenchao
name: Li, Shuo
name: Brown, Timothy C.
name: Sun, Qiang
name: Wang, Xuezhi
name: Yakovlev, Vladislav V.
name: Kealy, Allison
name: Moran, Bill
name: Greentree, Andrew D.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: Biological Physics (physics.bio-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Fluorescence microscopy is of vital importance for understanding biological function. However most fluorescence experiments are only qualitative inasmuch as the absolute number of fluorescent particles can often not be determined. Additionally, conventional approaches to measuring fluorescence intensity cannot distinguish between two or more fluorophores that are excited and emit in the same spectral window, as only the total intensity in a spectral window can be obtained. Here we show that, by using photon number resolving experiments, we are able to determine the number of emitters and their probability of emission for a number of different species, all with the same measured spectral signature. We illustrate our ideas by showing the determination of the number of emitters per species and the probability of photon collection from that species, for one, two, and three otherwise unresolvable fluorophores. The convolution Binomial model is presented to model the counted photons emitted by multiple species. And then the Expectation-Maximization (EM) algorithm is used to match the measured photon counts to the expected convolution Binomial distribution function. In applying the EM algorithm, to leverage the problem of being trapped in a sub-optimal solution, the moment method is introduced in finding the initial guess of the EM algorithm. Additionally, the associated Cramér-Rao lower bound is derived and compared with the simulation results.
Velocity Distributions and Correlations in Homogeneously Heated Granular Media
Creators: name: Moon, Sung Joon
name: Shattuck, M. D.
name: Swift, J. B.
Publisher: name: arXiv
Year: 2001
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We compare the steady state velocity distributions from our three-dimensional inelastic hard sphere molecular dynamics simulation for homogeneously heated granular media, with the predictions of a mean field-type Enskog-Boltzmann equation for inelastic hard spheres [van Noije & Ernst, Gran. Matt. {\bf 1}, 57 (1998)]. Although we find qualitative agreement for all values of density and inelasticity, the quantitative disagreement approaches $\sim 40%$ at high inelasticity or density. By contrast the predictions of the pseudo-Maxwell molecule model [Carrillo, Cercignani & Gamba, Phys. Rev. E, {\bf 62}, 7700 (2000)] are both qualitatively and quantitatively different from those of our simulation. We also measure short-range and long-range velocity correlations exhibiting non-zero correlations at contact before the collision, and being consistent with a slow algebraic decay over a decade in the unit of the diameter of the particle, proportional to $r^{-(1+α)}$, where $0.2 < α< 0.3$. The existence of these correlations imply the failure of the molecular chaos assumption and the mean field approximation, which is responsible for the quantitative disagreement of the inelastic hard sphere kinetic theory.
description: 23 pages, 15 figures, Phys. Rev. E, in press
Production Mechanism for Quark Gluon Plasma in Heavy Ion Collisions
Creators: name: Jain, Ambar
name: Ravishankar, V.
Publisher: name: arXiv
Year: 2002
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A general scheme is proposed here to describe the production of semi soft and soft quarks and gluons that form the bulk of the plasma in ultra relativistic heavy ion collisions. We show how to obtain rates as a function of time in a self consistent manner, without any ad-hoc assumption. All the required features - the dynamical nature of QCD vacuum, the non-Markovian nature of the production, and quasi particle nature of the partons, and the importance of quantum interference effects are naturally incorporated. We illustrate the results with a realistic albeit toy model and show how almost all the currently employed source terms are unreliable in their predictions. We show the rates in the momentum space and indicate at the end how to extract the full phase-space dependence.
description: 4 pages, 4 figures, two column
The primordial Helium abundance
Creators: name: Luridiana, V.
Publisher: name: arXiv
Year: 2002
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The primordial abundance of 4He, Y_P, is one of the hottest themes in present-day astronomy, mostly due to its cosmological relevance. The disagreement between different determinations has been currently reduced to the 1-2 percent level, but these differences are still large enough to have deep implications for Big-Bang nucleosynthesis. It is therefore crucial to estimate precisely the uncertainties involved in the measurement of Y_P. Here, I review the methods used in the determination of Y_P and the related uncertainties. I also discuss some recent results, and emphasize the assumptions underlying the differences among them.
description: 8 pages, 1 figure. Moriond Latex style. To be published in the proceedings of the XXXVIIth Moriond Astrophysics Meeting "The Cosmological Model", Les Arcs, France, March 16-23, 2002
Path Integrals and Perturbation Theory for Stochastic Processes
Creators: name: Dickman, Ronald
name: Vidigal, Ronaldo
Publisher: name: arXiv
Year: 2002
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We review and extend the formalism introduced by Peliti, that maps a Markov process to a path-integral representation. After developing the mapping, we apply it to some illustrative examples: the simple decay process, the birth-and-death process, and the Malthus-Verhulst process. In the first two cases we show how to obtain the exact probability generating function using the path integral. We show how to implement a diagrammatic perturbation theory for processes that do not admit an exact solution. Analysis of a set of coupled Malthus-Verhulst processes on a lattice leads, in the continuum limit, to a field theory for directed percolation and allied models.
description: 33 pages, 6 figures
Det-Det Correlations for Quantum Maps: Dual Pair and Saddle-Point Analyses
Creators: name: Nonnenmacher, S.
name: Zirnbauer, M. R.
Publisher: name: arXiv
Year: 2001
Subjects: subject: Mathematical Physics (math-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: An attempt is made to clarify the ballistic non-linear sigma model formalism recently proposed for quantum chaotic systems, by the spectral determinant Z(s)=Det(1-sU) of a quantized map U element of U(N). More precisely, we study the correlator omega_U(s)= (averaging t over the unit circle). Identifying the group U(N) as one member of a dual pair acting in the spinor representation of Spin(4N), omega_U(s) is expanded in terms of irreducible characters of U(N). In close analogy with the ballistic non-linear sigma model, a coherent-state integral representation of omega_U(s) is developed. We show that the leading-order saddle-point approximation reproduces omega_U(s) exactly, up to a constant factor; this miracle can be explained by interpreting omega_U(s) as a character of U(2N), for which the saddle-point expansion yields the Weyl character formula. Unfortunately, this decomposition behaves non-smoothly in the semiclassical limit, and to make further progress some averaging over U needs to be introduced. Several averaging schemes are investigated. In general, a direct application of the saddle-point approximation to these schemes is demonstrated to give incorrect results; this is not the case for a `semiclassical averaging scheme', for which all loop corrections vanish identically. As a side product of the dual pair decomposition, we compute a crossover between the Poisson and CUE ensembles for omega_U(s).
The lower mass function of young open clusters
Creators: name: Bouvier, J.
name: Moraux, E.
name: Stauffer, J. R.
name: Navascues, D. Barrado y
name: Cuillandre, J. -C.
Publisher: name: arXiv
Year: 2002
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report new estimates for the lower mass function of 5 young open clusters spanning an age range from 80 to 150 Myr. In all studied clusters, the mass function across the stellar/substellar boundary (~0.072 Mo) and up to 0.4 Mo is consistent with a power-law with an exponent alpha of -0.5 +/- 0.1, i.e., dN/dM ~ M**(-0.5).
description: 8 pages, 4 figures
Evidence of Two Distinct Dynamic Critical Exponents in Connection with Vortex Physics
Creators: name: Minnhagen, Petter
name: Kim, Beom Jun
name: Weber, Hans
Publisher: name: arXiv
Year: 2001
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The dynamic critical exponent $z$ is determined from numerical simulations for the three-dimensional (3D) lattice Coulomb gas (LCG) and the 3D XY models with relaxational dynamics. It is suggested that the dynamics is characterized by two distinct dynamic critical indices $z_0$ and $z$ related to the divergence of the relaxation time $τ$ by $τ\propto ξ^{z_0}$ and $τ\propto k^{-z}$, where $ξ$ is the correlation length and $k$ the wavevector. The values determined are $z_0\approx 1.5$ and $z\approx 1$ for the 3D LCG and $z_0\approx 1.5$ and $z\approx 2$ for the 3D XY model. It is argued that the nonlinear $IV$ exponent relates to $z_0$, whereas the usual Hohenberg-Halperin classification relates to $z$. Possible implications for the interpretation of experiments are pointed out. Comparisons with other existing results are discussed.
description: to appear in PRL
Application of Absorbing Boundary Condition to Nuclear Breakup Reactions
Creators: name: Ueda, Manabu
name: Yabana, Kazuhiro
name: Nakatsukasa, Takashi
Publisher: name: arXiv
Year: 2002
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Absorbing boundary condition approach to nuclear breakup reactions is investigated. A key ingredient of the method is an absorbing potential outside the physical area, which simulates the outgoing boundary condition for scattered waves. After discretizing the radial variables, the problem results in a linear algebraic equation with a sparse coefficient matrix, to which efficient iterative methods can be applicable. No virtual state such as discretized continuum channel needs to be introduced in the method. Basic aspects of the method are discussed by considering a nuclear two-body scattering problem described with an optical potential. We then apply the method to the breakup reactions of deuterons described in a three-body direct reaction model. Results employing the absorbing boundary condition are found to accurately coincide with those of the existing method which utilizes discretized continuum channels.
description: 21 pages, 5 figures, RevTeX4
Effect of Measurement Location on Cardiac Time Intervals Estimated by Seismocardiography
Creators: name: Mann, Aysha
name: Kakavand, Bahram
name: Gamage, Peshala Thibbotuwawa
name: Taebi, Amirtahà
Publisher: name: arXiv
Year: 2023
Subjects: subject: Medical Physics (physics.med-ph)
subject: Signal Processing (eess.SP)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Cardiac time intervals (CTIs) are important parameters for assessing cardiac function and can be measured using non-invasive methods such as electrocardiography (ECG) and seismocardiography (SCG). It is widely accepted that SCG signals, when measured from various locations on the chest surface, exhibit distinct temporal and spectral characteristics. In that regard, the goal of this study was to determine the effect of the SCG measurement location on estimating SCG-based CTIs. For this purpose, ECG, SCG, and phonocardiography (PCG) signals were acquired from fourteen healthy adult subjects. For SCG, three tri-axial accelerometers were attached on the top, middle, and bottom of the sternum with double-sided tape. In this study, only the dorsoventral components of the SCG signals were analyzed. Using Pan-Tompkin's algorithm, ECG R peaks and their temporal indices were found. Then, a custom-built algorithm in MATLAB was developed to estimate heart rate (HR) from ECG and SCG signals. Furthermore, SCG fiducial points and CTIs were defined from the SCG signals recorded from different sternal locations. The average and correlation coefficient of the CTIs and HRs derived from all three locations were compared. Mean difference and standard deviation were analyzed for the CTIs and their respective sensor location. Results demonstrated that SCG-based CTIs varied with the SCG measurement locations. In conclusion, these results highlighted the importance of establishing consistent research and clinical protocols for reporting CTIs based on SCG. This work also calls for further investigation into comparing estimated CTIs with gold-standard methods such as echocardiography and 4D cardiac computed tomography.
Partial Fourier series on compact Lie groups
Creators: name: Kirilov, Alexandre
name: de Moraes, Wagner Augusto Almeida
name: Ruzhansky, Michael
Publisher: name: arXiv
Year: 2019
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 22E30, 43A77 (Primary), 58D25, 43A25 (Secondary)

description: In this note we investigate the partial Fourier series on a product of two compact Lie groups. We give necessary and sufficient conditions for a sequence of partial Fourier coefficients to define a smooth function or a distribution. As applications, we will study conditions for the global solvability of an evolution equation defined on $\mathbb{T}^1\times\mathbb{S}^3$ and we will show that some properties of this evolution equation can be obtained from a constant coefficient equation.
description: 21 pages
Surface anchoring on layers of grafted liquid-crystalline chain molecules: A computer simulation
Creators: name: Lange, Harald
name: Schmid, Friederike
Publisher: name: arXiv
Year: 2002
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: By Monte Carlo simulations of a soft ellipsoid model for liquid crystals, we study whether a layer of grafted liquid-crystalline chain molecules can induce tilt in a nematic fluid. The chains are fairly short (four monomers) and made of the same particles as the solvent. They are attached to a substrate which favors parallel (planar) alignment. At low grafting densities, the substrate dominates and we observe planar alignment. On increasing the grafting density, we find a first order transition from planar to tilted alignment. Beyond the transition, the tilt angle with respect to the surface normal decreases continuously. The range of accessible anchoring angles is quite large.
description: To appear in J. Chem. Phys
PROFIT, SUPPLY AND INPUT DEMAND FUNCTIONS: A CASE STUDY OF WINTER RICE IN BANGLADESH
Creators: name: Ahmed, A.
name: Molla, A.R.
name: Ashraf, M.A.
name: Ahmed, A.
name: Molla, A.R.
name: Ashraf, M.A.
Publisher: name: Unknown
Year: 1987
Subjects: Research Methods/ Statistical Methods

description: A cross section sample of 98 rice farm families in the five selected villages of Modhupur Upazila of Tangail District were surveyed in the year, 1983- The :findings are that farmers as a whole in the study area are economically inefficient, but large farmers are relatively more efficient than the small farmers. The production of rice by small farmers is more responsive to changes in the price of rice, fertilizer and land area than in the case of large farmers.
Electromagnetomotive force fields in noninertial reference frames and accelerated superconducting quantum interferometers
Creators: name: Fischer, Uwe R.
name: Haeussler, Christoph
name: Oppenlaender, Joerg
name: Schopohl, Nils
Publisher: name: arXiv
Year: 2001
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We discuss the prospects of detecting with high precision the force fields related to noninertiality in superconducting circuits. Special emphasis is laid on the perfectly conducting and perfect diamagnetism analogues of the Tolman-Stewart respectively Barnett effects. The influence of acceleration and rotation on the electrodynamics of superconducting interferometers is explicitly described. In particular, we show how motion induced changes of the oscillation frequency of the local Josephson oscillators in superconducting quantum interference filters can be used for precision measurements of acceleration in free space.
description: 9 pages, 3 figures; final version
NFAD: Fixing anomaly detection using normalizing flows
Creators: name: Ryzhikov, Artem
name: Borisyak, Maxim
name: Ustyuzhanin, Andrey
name: Derkach, Denis
Publisher: name: arXiv
Year: 2019
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Anomaly detection is a challenging task that frequently arises in practically all areas of industry and science, from fraud detection and data quality monitoring to finding rare cases of diseases and searching for new physics. Most of the conventional approaches to anomaly detection, such as one-class SVM and Robust Auto-Encoder, are one-class classification methods, i.e. focus on separating normal data from the rest of the space. Such methods are based on the assumption of separability of normal and anomalous classes, and subsequently do not take into account any available samples of anomalies. Nonetheless, in practical settings, some anomalous samples are often available; however, usually in amounts far lower than required for a balanced classification task, and the separability assumption might not always hold. This leads to an important task -- incorporating known anomalous samples into training procedures of anomaly detection models. In this work, we propose a novel model-agnostic training procedure to address this task. We reformulate one-class classification as a binary classification problem with normal data being distinguished from pseudo-anomalous samples. The pseudo-anomalous samples are drawn from low-density regions of a normalizing flow model by feeding tails of the latent distribution into the model. Such an approach allows to easily include known anomalies into the training process of an arbitrary classifier. We demonstrate that our approach shows comparable performance on one-class problems, and, most importantly, achieves comparable or superior results on tasks with variable amounts of known anomalies.
On shattering, splitting and reaping partitions
Creators: name: Halbeisen, Lorenz
Publisher: name: arXiv
Year: 2001
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03E05; 03E35; 03C25; 04A20; 05A18

description: In this article we investigate the dual-shattering cardinal H, the dual-splitting cardinal S and the dual-reaping cardinal R, which are dualizations of the well-known cardinals h (the shattering cardinal, also known as the distributivity number of P(omega) modulo finite, s (the splitting number) and r (the reaping number). Using some properties of the ideal J of nowhere dual-Ramsey sets, which is an ideal over the set of partitions of omega, we show that add(J)=cov(J)=H. With this result we can show that H > omega_1 is consistent with ZFC and as a corollary we get the relative consistency of H > t, where t is the tower number. Concerning S we show that cov(M) is less than or equal to S (where M is the ideal of the meager sets). For the dual-reaping cardinal R we get p is less than or equal to R, which is less than or equal to r (where p is the pseudo-intersection number) and for a modified dual-reaping number R' we get that R' is less than or equal to d (where d is the dominating number). As a consistency result we get R < cov(M).
MUKTA PADDY MARKETING PROJECT: AN EVALUATION
Creators: name: RAHMAN, M.L.
name: MURSHED, S.M.M.
name: HUQ, A.F.M.F.
name: RAHMAN, M.L.
name: MURSHED, S.M.M.
name: HUQ, A.F.M.F.
Publisher: name: Unknown
Year: 1987
Subjects: subject: Marketing
subject: FOS: Economics and business

description: This paper attempts to analyse various aspects of Mukta paddy marketing project as a pioneering cooperative marketing venture and evaluate its performance. Inspite of much potentiality the project seems to have failed to provide benefits to the farmers as expected. The farmers' participation also has not been encouraging. To improve the performance of the project a number of measures have been recommended.
AN ANALYSIS OF DIFFERENCES BETWEEN ADOPTERS AND NON-ADOPTERS OF HIGH YIELDING VARIETIES OF RICE AMONG SMALL FARMERS
Creators: name: Kashem, M. A.
name: Kashem, M. A.
Publisher: name: Unknown
Year: 1987
Subjects: Research and Development/Tech Change/Emerging Technologies

description: Small farmers constituting about two-thirds of the rural households mostly cultivate rice. Adoption of high yielding varieties (HYVs) of rice is one of the ways to increase average rice yield of an individual as well as total rice production of the country. However, as individual characteristics may differ between adopters and non-adopters of HYV rice. the present study was undertaken in order to analyse the extent of differences between adopters and non-adopters of HYV rice among small farmers. The findings indicate that very few differences in the individual characteristics exist between the adopters and non-adopters of HYV rice, Small farmers as a whole, therefore, can be considered as a single category for conducting extension work without segregating them into different categories on the basis of their adoption and non-adoption of HYV rice.
INFLUENCE OF TENURIAL STATUS OF LAND ON THE ADOPTION OF IMPROVED PRODUCTION TECHNOLOGY IN AN AREA OF BANGLADESH
Creators: name: BHUIYAN, M. S. R.
name: BHUIYAN, M. S. R.
Publisher: name: Unknown
Year: 1987
Subjects: Research and Development/Tech Change/Emerging Technologies

description: Analysis of field data collected from a sample of 100 part-tenant farmers has brought out findings about influence of tenurial status of land on adoption of improved seed-fertilizer-irrigation technology. Adoption of improved production technology tended to be the highest on owned land followed by cash rented land, crop-share rented land with input cost-sharing and crop-share rented land without input cost-sharing. Thus, the findings lead to suggest that irrespective of rental arrangements the mechanism of land tenancy acts as hinderance to adoption of improved production technology. Inter-rental system comparison reveals that cash renting system is a better mechanism than crop-share renting even if with input-cost sharing. However, input cost-sharing practice accelerated adoption of improved production technology on crop-share rented land.
Additional file 1: of Effective integration of sexual reproductive health and HIV prevention, treatment, and care services across sub-Saharan Africa: where is the evidence for program implementation?
Creators: name: Kangudie, Didier
name: Guidigbi, Hugues
name: Mensah, Sheila
name: Bala, Abdul
name: Delate, Richard
Publisher: name: figshare
Year: 2019
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Cancer
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: 60506 Virology
subject: Computational Biology

description: Translation of this article into French. (PDF 173 kb)
A modified version of the Gregory-Loredo method for Bayesian periodic signal detection
Creators: name: Aigrain, S.
name: Favata, F.
Publisher: name: arXiv
Year: 2002
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The detection of planetary transits in stellar photometric light-curves is poised to become the main method for finding substantial numbers of terrestrial planets. The French-European mission COROT (foreseen for launch in 2005) will perform the first search on a limited number of stars, and larger missions Eddington (from ESA) and Kepler (from NASA) are planned for launch in 2007. Transit signals from terrestrial planets are small (Delta_F/F approx 10^{-4}), short (Delta_t approx 10 hours) dips, which repeat with periodicity of a few months, in time series lasting up to a few years. The reliable and automated detection of such signals in large numbers of light curves affected by different sources of noise is a statistical and computational challenge. We present a novel algorithm based on a Bayesian approach. The algorithm is based on the Gregory-Loredo method originally developed for the detection of pulsars in X-ray data. In the present paper the algorithm is presented, and its performance on simulated data sets dominated by photon noise is explored. In an upcoming paper the influence of additional noise sources (such as stellar activity) will be discussed.
description: 12 pages, 11 figures, uses bibtex and the macros aa.cls and aa.bst. Accepted for publication in Astronomy and Astrophysics
Trion photoluminescence and trion stability in atomically thin semiconductors
Creators: name: Perea-Causin, Raul
name: Brem, Samuel
name: Schmidt, Ole
name: Malic, Ermin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The optical response of doped monolayer semiconductors is governed by trions, i.e. photoexcited electron-hole pairs bound to doping charges. While their photoluminescence (PL) signatures have been identified in experiments, a microscopic model consistently capturing bright and dark trion peaks is still lacking. In this work, we derive a generalized trion PL formula on a quantum-mechanical footing, considering direct and phonon-assisted recombination mechanisms. We show the trion energy landscape in WSe$_2$ by solving the trion Schrödinger equation. We reveal that the mass imbalance between equal charges results in less stable trions exhibiting a small binding energy and, interestingly, a large energetic offset from exciton peaks in PL spectra. Furthermore, we compute the temperature-dependent PL spectra for n- and p-doped monolayers and predict yet unobserved signatures originating from trions with an electron at the $Λ$ point. Our work presents an important step towards a microscopic understanding of the internal structure of trions determining their stability and optical fingerprint.
Decision Models for Workforce and Technology Planning in Services
Creators: name: Li, Gang
name: Field, Joy M.
name: Jiang, Hongxun
name: He, Tian
name: Pang, Youming
Publisher: name: arXiv
Year: 2019
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business

description: Today's service companies operate in a technology-oriented and knowledge-intensive environment while recruiting and training individuals from an increasingly diverse population. One of the resulting challenges is ensuring strategic alignment between their two key resources - technology and workforce - through the resource planning and allocation processes. The traditional hierarchical decision approach to resource planning and allocation considers only technology planning as a strategic-level decision, with workforce recruiting and training planning as a subsequent tactical-level decision. However, two other decision approaches - joint and integrated - elevate workforce planning to the same strategic level as technology planning. Thus we investigate the impact of strategically aligning technology and workforce decisions through the comparison of joint and integrated models to each other and to a baseline hierarchical model in terms of the total cost. Numerical experiments are conducted to characterize key features of solutions provided by these approaches under conditions typically found in this type of service company. Our results show that the integrated model is the lowest cost across all conditions. This is because the integrated approach maintains a small but skilled workforce that can operate new and more advanced technology with higher capacity. However, the cost performance of the joint model is very close to the integrated model under many conditions and is easier to implement computationally and managerially, making it a good choice in many environments. Managerial insights derived from this study can serve as a valuable guide for choosing the proper decision approach for technology-oriented and knowledge-intensive service companies.
description: 31 pages, 7 tables
Kähler manifolds with almost non-negative curvature
Creators: name: Lee, Man-Chun
name: Tam, Luen-Fai
Publisher: name: arXiv
Year: 2019
Subjects: subject: Differential Geometry (math.DG)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: In this paper, we construct local and global solutions to the Kähler-Ricci flow from a non-collapsed Kähler manifold with curvature bounded from below. Combines with the mollification technique of McLeod-Simon-Topping, we show that the Gromov-Hausdorff limit of sequence of complete noncompact non-collapsed Kähler manifolds with orthogonal bisectional curvature and Ricci curvature bounded from below is homeomorphic to a complex manifold. We also use it to study the complex structure of complete Kähler manifolds with nonnegative orthogonal bisectional curvature, nonnegative Ricci curvature and maximal volume growth.
description: 32 pages
Insights into the Origin of Mass
Creators: name: Roberts, Craig D.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Atomic nuclei are the core of everything we can see. At the first level of approximation, their atomic weights are simply the sum of the masses of all the nucleons they contain. Each nucleon has a mass $m_N \approx 1\,$GeV, i.e. approximately 2000-times the electron mass. The Higgs boson produces the latter, but what produces the nucleon mass? This is the crux: the vast bulk of the mass of a nucleon is lodged with the energy needed to hold quarks together inside it; and that is supposed to be explained by quantum chromodynamics (QCD), the strong-interaction piece within the Standard Model. This contribution canvasses the potential for a coherent effort in QCD phenomenology and theory, coupled with experiments at existing and planned facilities, to reveal the origin and distribution of mass by focusing on the properties of the strong-interaction Nambu-Goldstone modes. Key experiments are approved at JLab 12; planned with COMPASS++/AMBER at CERN; and could deliver far-reaching insights by exploiting the unique capabilities foreseen at an electron ion collider.
description: 9 pages, 4 figures. Summary of a plenary presentation at "INPC 2019 - 27th International Nuclear Physics Conference", Glasgow, UK, 29 July to 2 August, 2019. arXiv admin note: substantial text overlap with arXiv:1909.11102
Studying the mass sensitivity of air-shower observables using simulated cosmic rays
Creators: name: Flaggs, Benjamin
name: Coleman, Alan
name: Schröder, Frank G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Using CORSIKA simulations, we investigate the mass sensitivity of cosmic-ray air-shower observables for sites at the South Pole and Malargüe, Argentina, the respective locations of the IceCube Neutrino Observatory and the Pierre Auger Observatory. Exact knowledge of observables from air-shower simulations was used to study the event-by-event mass separation between proton, helium, oxygen, and iron primary cosmic rays with a Fisher linear discriminant analysis. Dependencies on the observation site as well as the energy and zenith angle of the primary particle were studied in the ranges from $10^{16.0}-10^{18.5}\,$eV and $0^\circ$ to $60^\circ$: they are mostly weak and do not change the qualitative results. Promising proton-iron mass separation is achieved using combined knowledge of all studied observables, also when typical reconstruction uncertainties are accounted for. However, even with exact measurements, event-by-event separation of intermediate-mass nuclei is challenging and better methods than the Fisher discriminant and/or the inclusion of additional observables will be needed. As an individual observable, high-energy muons ($> 500\,$GeV) provide the best event-by-event mass discrimination, but the combination of muons of any energy and $X_{\text{max}}$ provides already a high event-by-event separation between proton-iron primaries at both sites. We also confirm that the asymmetry and width parameters of the air-shower longitudinal profile, $R$ and $L$, are mass sensitive. Only $R$ seems to be suitable for event-by-event mass separation, but $L$ can potentially be used to statistically determine the proton-helium ratio. Overall, our results motivate the coincident measurement of several air-shower observables, including at least $X_{\text{max}}$ and the sizes of the muonic and electromagnetic shower components, for the next generation of air-shower experiments.
Generalizable synthetic MRI with physics-informed convolutional networks
Creators: name: Jacobs, Luuk
name: Mandija, Stefano
name: Liu, Hongyan
name: Berg, Cornelis A. T. van den
name: Sbrizzi, Alessandro
name: Maspero, Matteo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Medical Physics (physics.med-ph)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: In this study, we develop a physics-informed deep learning-based method to synthesize multiple brain magnetic resonance imaging (MRI) contrasts from a single five-minute acquisition and investigate its ability to generalize to arbitrary contrasts to accelerate neuroimaging protocols. A dataset of fifty-five subjects acquired with a standard MRI protocol and a five-minute transient-state sequence was used to develop a physics-informed deep learning-based method. The model, based on a generative adversarial network, maps data acquired from the five-minute scan to "effective" quantitative parameter maps, here named q*-maps, by using its generated PD, T1, and T2 values in a signal model to synthesize four standard contrasts (proton density-weighted, T1-weighted, T2-weighted, and T2-weighted fluid-attenuated inversion recovery), from which losses are computed. The q*-maps are compared to literature values and the synthetic contrasts are compared to an end-to-end deep learning-based method proposed by literature. The generalizability of the proposed method is investigated for five volunteers by synthesizing three non-standard contrasts unseen during training and comparing these to respective ground truth acquisitions via contrast-to-noise ratio and quantitative assessment. The physics-informed method was able to match the high-quality synthMRI of the end-to-end method for the four standard contrasts, with mean \pm standard deviation structural similarity metrics above 0.75 \pm 0.08 and peak signal-to-noise ratios above 22.4 \pm 1.9 and 22.6 \pm 2.1. Additionally, the physics-informed method provided retrospective contrast adjustment, with visually similar signal contrast and comparable contrast-to-noise ratios to the ground truth acquisitions for three sequences unused for model training, demonstrating its generalizability and potential application to accelerate neuroimaging protocols.
description: 23 pages, 7 figures, 1 table. Presented at ISMRM 2022. Will be submitted to NMR in biomedicine
Chinese Consumer Willingness to Pay for Pork with Credence Quality Attributes
Creators: name: Dong, Hao
name: Hu, Wuyang
name: Dong, Hao
name: Hu, Wuyang
Publisher: name: Unknown
Year: 2016
Subjects: subject: Consumer/Household Economics
subject: Willingness To Pay
subject: Consumer Preference
subject: Pork
subject: China
subject: Credence Quality Attributes

description: Food labeling has become increasingly important in pork marketing. Various labels such as local production, organic, and non-GMOs are reported as being valued by consumers across different countries and cultures. China is the largest pork consumer and producer in the world. However, studies on Chinese consumer perception and willingness to pay for various pork attributes are scarce. This study examines how credence attributes related to pork quality may affect Chinese consumers’ pork consumption. Results show that Chinese consumers are particularly responsive to pork’s food safety information and they also attach value to authenticity of the product information.