cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Gravitational Scattering in the ADD-model Revisited
Creators: name: Sjodahl, Malin
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Gravitational scattering in the ADD-model is studied and it is argued that no cut-off is needed for the exchange of virtual Kaluza--Klein modes. By introduction of a small coordinate in the extra dimensions a unique form of the Kaluza--Klein-summed propagator is found for an odd number of extra dimensions. The matrix element corresponding to this propagator can also (as opposed to the cut-offed version) be Fourier transformed to position space, giving back the extra-dimensional version of Newton's law. For an even number of extra dimensions the propagator is found by requiring that Newton's law should be recovered.
Generalized diagonalization scheme for many-particle systems
Creators: name: Sykora, Steffen
name: Hübsch, Arnd
name: Becker, Klaus W.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Despite the advances in the development of numerical methods analytical approaches still play the key role on the way towards a deeper understanding of many-particle systems. In this regards, diagonalization schemes for Hamiltonians represent an important direction in the field. Among these techniques the method, presented here, might be that approach with the widest range of possible applications: We demonstrate that both stepwise and continuous unitary transformations to diagonalize the many-particle Hamiltonian as well as perturbation theory and also non-perturbative treatments can be understood within the same theoretical framework. The new method is based on the introduction of generalized projection operators and allows to develop a renormalization scheme which is used to evaluate directly the physical quantities of a many-particle system. The applicability of this approach is shown for two important elementary many-particle problems.
description: 19 pages, 6 figures
Exact moments and re-entrant transitions in the inertial dynamics of active Brownian particles
Creators: name: Patel, Manish
name: Chaudhuri, Debasish
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: In this study, we investigate the behavior of free inertial Active Brownian Particles (ABP) in the presence of thermal noise. While finding a closed-form solution for the joint distribution of positions, orientations, and velocities using the Fokker-Planck equation is generally challenging, we utilize a Laplace transform method to obtain the exact temporal evolution of all dynamical moments in arbitrary dimensions. Our expressions in $d$ dimensions reveal that inertia significantly impacts steady-state kinetic temperature and swim pressure while leaving the late-time diffusivity unchanged. Notably, as a function of activity and inertia, the steady-state velocity distribution exhibits a remarkable re-entrant crossover from passive Gaussian to active non-Gaussian behaviors. We construct a corresponding phase diagram using the exact expression of the $d$-dimensional kurtosis. Our analytic expressions describe steady states and offer insights into time-dependent crossovers observed in moments of velocity and displacement. Our calculations can be extended to predict up to second-order moments for run-and-tumble particles (RTP) and the active Ornstein-Uhlenbeck process (AOUP). Additionally, the kurtosis shows differences from AOUP.
description: 24 pages, single column, 6 figures; version accepted for publication in New Journal of Physics
The linear sigma model at a finite isospin chemical potential
Creators: name: Mao, Hong
name: Petropoulos, Nicholas
name: Shu, Song
name: Zhao, Wei-Qin
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The effect of finite isospin chemical potential to the effective masses of the mesons at finite temperature is investigated in the framework of the O(4) linear sigma model with explicit chiral symmetry breaking. We present a mechanism to include the isospin chemical potential in the model. By using the Cornwall-Jackiw-Tomboulis method of composite operators, we obtain a set gap equations for the effective masses of the mesons and get the numerical results in the Hartree approximation. We find that the introduction of the chemical potential only affects the mass of the charged pions and sigma, while there is almost NO effects on the mass of neutral pions.
description: 11 pages, 6 figures; Version to appear in J. Phys. G
The Eastern Question from Shanghai : Views of the Ottoman Empire in Shenbao, 1870s-1880s
Creators: name: Nomura, Haruka
Publisher: name: The Australian National University
Year: 2017

description: This thesis examines late-Qing Chinese perspectives of world order. Concentrating on the images of the Ottoman Empire in the Shanghai-based, Chinese-language commercial newspaper Shenbao (1872-1949), this study examines how the Chinese elite rethought China's position among expanding European empires based on their understanding of the contemporary world. During the 1870s and 1880s the Ottoman Empire emerged as a theatre of European politics in the newspaper owing primarily to the "Eastern Question," a series of British diplomatic concerns arising from the disintegration of the Ottoman Empire. One of the earliest Chinese-language newspaper ventures in China, Shenbao provides a rare window on the lively discussions about a wide range of political and cultural issues among the little-known elite authors in and around Shanghai where the histories of Qing China and the British Empire intersected.Considering empire as a useful umbrella term to mean certain forms of large state, the chapters explore thematically the relationship between the notions of the world and the state (guo) as two primary fields of ordering in Shenbao. Chapter 1 situates Shenbao's writing at the intersection of Qing and British news networks that brought China the Eastern Question. Chapter 2 considers the implications of the Eastern Question in Chinese official writings, to argue that the East in question encompassed China between the 1840s and 1880s. Chapter 3 considers vocabularies used by Shenbao in imagining the Ottoman Empire in an unfamiliar scheme of the world spanning the entire surface of the globe. Chapter 4 moves on to the concept of state and its internal constitution consisting of human relationships extending beyond the state, as seen through the replacement of the Ottoman sovereigns in the palace coups d'etat in mid-1876, and concurrent armed uprisings within the Ottoman Empire. In turn Chapter 5 analyses reports on the Russo-Ottoman War of 1877-1878, to chart the limits of the state and the sense of the temporal and spatial breakdown between a state and the world. Chapter 6 continues the enquiry on a different subject of foreign trade which was central to Shenbao's ancient imagination of a unified world-state.
Enhanced reaction kinetics in biological cells
Creators: name: Loverdo, C.
name: Benichou, O.
name: Moreau, M.
name: Voituriez, R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Cell Behavior (q-bio.CB)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The cell cytoskeleton is a striking example of "active" medium driven out-of-equilibrium by ATP hydrolysis. Such activity has been shown recently to have a spectacular impact on the mechanical and rheological properties of the cellular medium, as well as on its transport properties : a generic tracer particle freely diffuses as in a standard equilibrium medium, but also intermittently binds with random interaction times to motor proteins, which perform active ballistic excursions along cytoskeletal filaments. Here, we propose for the first time an analytical model of transport limited reactions in active media, and show quantitatively how active transport can enhance reactivity for large enough tracers like vesicles. We derive analytically the average interaction time with motor proteins which optimizes the reaction rate, and reveal remarkable universal features of the optimal configuration. We discuss why active transport may be beneficial in various biological examples: cell cytoskeleton, membranes and lamellipodia, and tubular structures like axons.
description: 10 pages, 2 figures
A-Priori Reduction of Scenario Approximation for Automated Generation Control in High-Voltage Power Grids with Renewable Energy
Creators: name: Lukashevich, Aleksander
name: Bulkin, Aleksander
name: Maximov, Yury
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optimization and Control (math.OC)
subject: Computation (stat.CO)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Renewable energy sources (RES) are increasingly integrated into power systems to support the United Nations' Sustainable Development Goals of decarbonization and energy security. However, their low inertia and high uncertainty pose challenges to grid stability and increase the risk of blackouts. Stochastic chance-constrained optimization, particularly data-driven methods, offers solutions but can be time-consuming, especially when handling multiple system snapshots. This paper addresses a dynamic joint chance-constrained Direct Current Optimal Power Flow (DC-OPF) problem with Automated Generation Control (AGC) to facilitate cost-effective power generation while ensuring that balance and security constraints are met. We propose an approach for a data-driven approximation that includes a priori sample reduction, maintaining solution reliability while reducing the size of the data-driven approximation. Both theoretical analysis and empirical results demonstrate the superiority of this approach in handling generation uncertainty, requiring up to twice less data while preserving solution reliability.
description: 6 pages, 6 figures
Gauge symmetries of strings in supertwistor space
Creators: name: Uvarov, D. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recently we have considered supertwistor reformulation of the D=4 N=1,2 superstring action that comprises Newman-Penrose dyad components and is classically equivalent to the Green-Schwarz one. It was shown that in the covariant kappa-symmetry gauge the supertwistor representation of the string action simplifies. Here we analyze its Hamiltonian formulation, classify the constraints on the phase-space variables, and find the covariant set of generators of the gauge symmetries. Quantum symmetries of the supertwistor representation of the string action are examined applying the world-sheet CFT technique. Considered are various generalizations of the model from the perspective of their possible relation to known twistor superstring models.
description: 17 pages, LaTeX; v.2 minor changes in the text, references added, misprints corrected
Piecewise nonlinear materials and Monotonicity Principle
Creators: name: Esposito, Antonio Corbo
name: Faella, Luisa
name: Mottola, Vincenzo
name: Piscitelli, Gianpaolo
name: Prakash, Ravi
name: Tamburrino, Antonello
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: This paper is focused on the Monotonicity Principle (MP) for nonlinear materials with piecewise growth exponent. This results are relevant because enables the use of a fast imaging method based on MP, to the wide class of problems with two or more materials, where at least one is nonlinear.
 The treatment is very general and allows to model a wide variety of practical configurations such as, for instance, Superconducting (SC) or Perfect Electrical Conducting (PEC) or Perfect Electrical Insulating (PEI) materials.
 A key role is played by the average Dirichlet-to-Neumann operator, introduced in [Corbo Esposito et. al, Inverse Problems 2021], where the MP for a single type of nonlinearity was treated.
 Realistic numerical examples confirm the theoretical findings.
Optimization of loading factor preventing target cancellation
Creators: name: Oreshkin, Boris N.
name: Bakulev, Peter A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Adaptive algorithms based on sample matrix inversion belong to an important class of algorithms used in radar target detection to overcome prior uncertainty of interference covariance. Sample matrix inversion problem is generally ill conditioned. Moreover, the contamination of the empirical covariance matrix by the useful signal leads to significant degradation of performance of this class of adaptive algorithms. Regularization, also known in radar literature as sample covariance loading, can be used to combat both ill conditioning of the original problem and contamination of the empirical covariance by the desired signal. However, the optimum value of loading factor cannot be derived unless strong assumptions are made regarding the structure of covariance matrix and useful signal penetration model. In this paper an iterative algorithm for loading factor optimization based on the maximization of empirical signal to interference plus noise ratio (SINR) is proposed. The proposed solution does not rely on any assumptions regarding the structure of empirical covariance matrix and signal penetration model. The paper also presents simulation examples showing the effectiveness of the proposed solution.
Repulsive, nonmonotonic Casimir forces in a glide-symmetric geometry
Creators: name: Rodriguez, Alejandro W.
name: Joannopoulos, John D.
name: Johnson, Steven G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We describe a three-dimensional geometry that exhibits a repulsive Casimir force using ordinary metallic materials, as computed via an exact numerical method (no uncontrolled approximations). The geometry consists of a zippelike, glide-symmetric structure formed of interleaved metal brackets attached to parallel plates. Depending on the separation, the perpendicular force between the plates/brackets varies from attractive (large separations) to repulsive (intermediate distances) and back to attractive (close separations), with one point of stable equilibrium in the perpendicular direction. This geometry was motivated by a simple intuition of attractive interactions between surfaces, and so we also consider how a rough proximity force approximation of pairwise attractions compares to the exact calculations.
An investigation into the forming behaviour of metal composite hybrids
Creators: name: Dhar Malingam, Sivakumar
Publisher: name: The Australian National University
Year: 2018
Subjects: subject: TA481.5.D53 2011
subject: Metallic composites
subject: Fibrous composites
subject: Composite materials in automobiles

description: In an effort to reduce gas emissions from fuel combustion generated by the transportation sector the use of lightweight materials such as composites are currently being intensively explored. Fuel-economy improvement for passenger vehicles is projected to increase by 6-7 % for every 10 % of weight reduction. Composite materials are stronger than steel and lighter than aluminium. Fibre Metal Laminates (FML) is a class of composite material comprised by alternating aluminium sheets and composites which has been successfully employed in the aerospace industry. The resulting synergy of material properties gives FMLs superior mechanical properties when compared with those of their individual constituent materials. FMLs based on thermoplastic composites have been shown to possess better fracture toughness, shorter processing times, good impact and localised blast resistance as well as being recyclable. For the automotive industry to take advantage of FML's superior mechanical properties, the forming behaviours of this class of material need to be understood. Stamp forming is a much cheaper way to produce FML parts in high-volume industries compared to autoclaving. FML systems can be immediately used as a replacement for metal in production lines with minimal change to stamp-forming tools. Two systems of FML with different fiber stiffness, FMIL-Curv and FML-Twintex, were benchmarked with monolithic aluminium of the same thickness to study their formability. Full factorial experimental work was conducted to study the influence of process parameters -binder force, feedrate and preheat temperature, using the Swift test. The Swift round-bottom test was chosen to study both stretch and draw behaviour during forming. A full field-strain measurement system was used to study the effects of varying forming conditions on strain evolution in real time during the stamp-forming process. A statistical test, ANOVA, shows that preheat temperature and binder force have significant effects on strain evolution for both FML systems. FML samples showed better strain distribution in stretch forming compared to monolithic aluminium. They also required less work to form and have a weight reduction of approximately 30% when compared to aluminium samples. High-temperature forming is preferred for FML-Twintex while low-temperature forming is better for FML-Curv. FML-Curv can also be formed to higher depths compared to monolithic aluminium. By proper selection of process parameters, contact conditions and composite fiber properties it is possible to produce FML parts that have superior formability characteristics compared to monolithic metals. A predictive finite element model was developed to model forming process. The results from the finite element solution showed a high degree of correlation with experimental results.
Vowel harmonies of the Congo Basin : an optimality theory analysis of variation in the Bantu zone C
Creators: name: Leitch, Myles Francis
Publisher: name: University of British Columbia
Year: 2009

description: A central claim of Optimality Theory (Prince and Smolensky 1993, McCarthy and Prince 1993a) is that phonological variation can be modeled through the variable ranking of universal constraints. In this thesis, I test this claim by examining variation in the tongue root vowel harmony system in a number of closely related yet distinct Bantu languages of Congo and Zaire. The twenty-odd languages are drawn from each of Guthrie 1967's eight Bantu C. subgroups and are shown to vary along a number of dimensions. One is morphological, related to whether or not the harmonic element in the lexical root extends to prefixes and suffixes. This variation is shown to follow from the variable ranking of constraints that seek to ALIGN the harmonic feature, [retracted tongue root] ([rtr]) with the edges of the morphological domains STEM and WORD. A second parameter of variation concerns the relationship between high vowels and [rtr]. A third dimension involves the interaction of [rtr] with the low vowel [a] under harmony. Here, three patterns involving (i) low vowel assimilation, (ii) low vowel opacity, or (iii) low vowel transparency under harmony are shown to follow from the variable ranking of a few constraints. A significant theme that emereges in the study is recognizing and characterizing the distinct morphological and phonological domain edges involved in vowel harmony. An important contribution of this study is in bringing to light a language family where phonological tongue height, in this case expressed by the feature [low], is shown to be incompatible with tongue root retraction, as expressed in the feature [rtr]. Although the gestures of tongue body lowering and tongue root retraction are sympathetic in the articulatory dimension and in their acoustic effect, they are seen to be phonologically hostile, in fact, because of the redundancy relation between them. This redundancy-based phonological incompatibility is implemented via licensing-failure: [low] fails to "license" [rtr] because lowness implies retraction (Ito, Mester and Padgett 1994).
Newspaper clipping titled "Half Okanagan Fruit Lots are 7.5 Acres or Less" and "Fumigation for Oriental Fruit Moth Takes in Two Canneries, Large Orchard
Creators: name: [Unknown]
Publisher: name: The University of British Columbia
Year: 2017

description: Newspaper clipping titled "Half Okanagan Fruit Lots are 7.5 Acres or Less" and "Fumigation for Oriental Fruit Moth Takes in Two Canneries, Large Orchard" regarding the size of Okanagan fruit lots and the biggest fumigation operation in Canadian history.
An autonomous out of equilibrium Maxwell's demon for controlling the energy fluxes produced by thermal fluctuations
Creators: name: Ciliberto, Sergio
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: An autonomous out of equilibrium Maxwell's demon is used to reverse the natural direction of the heat flux between two electric circuits kept at different temperatures and coupled by the electric thermal noise. The demon does not process any information, but it achieves its goal by using a frequency dependent coupling with the two reservoirs of the system. There is no energy flux between the demon and the system, but the total entropy production (system+demon) is positive. The demon can be power supplied by thermocouples. The system and the demon are ruled by equations similar to those of two coupled Brownian particles and of the Brownian gyrator. Thus our results pave the way to the application of autonomous out equilibrium Maxwell demons to coupled nanosystems at different temperatures.
Quantifying the stellar ages of dynamically separated bulges and disks of CALIFA spiral galaxies
Creators: name: Jin, Yunpeng
name: Zhu, Ling
name: Zibetti, Stefano
name: Costantin, Luca
name: van de Ven, Glenn
name: Mao, Shude
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We employ a recently developed population-orbit superposition technique to simultaneously fit the stellar kinematic and age maps of 82 CALIFA spiral galaxies and obtain the ages of stars in different dynamical structures. We first evaluated the capabilities of this method on CALIFA-like mock data created from the Auriga simulations. The recovered mean ages of dynamically cold, warm, and hot components match the true values well, with an observational error of up to $20\%$ in the mock age maps. For CALIFA spiral galaxies, we find that the stellar ages of the cold, warm, and hot components all increase with the stellar mass of the galaxies, from $\overline{t_{\rm cold}}\sim2.2$ Gyr, $\overline{t_{\rm warm}}\sim2.3$ Gyr, and $\overline{t_{\rm hot}}\sim2.6$ Gyr for galaxies with stellar mass $M_*<10^{10}\,\rm M_{\odot}$, to $\overline{t_{\rm cold}}\sim4.0$ Gyr, $\overline{t_{\rm warm}}\sim5.1$ Gyr, and $\overline{t_{\rm hot}}\sim5.9$ Gyr for galaxies with $M_*>10^{11}\,\rm M_{\odot}$. About $80\%$ of the galaxies in our sample have $t_{\rm hot}>t_{\rm cold}$, and the mean values of $t_{\rm hot}-t_{\rm cold}$ also increase with stellar mass, from $0.7_{-0.2}^{+0.6}$ Gyr in low-mass galaxies ($10^{8.9}\,\rm M_{\odot}
description: 22 pages, 18 figures
Population ecology of the clonal red alga Mazzaella Cornucopiae from Barkley Sound, Canada
Creators: name: Scrosati, Ricardo Augusto
Publisher: name: University of British Columbia
Year: 2009

description: This Thesis examines aspects of the population ecology of clonal algae using as a model Mazzaella cornucopiae (Rhodophyta, Gigartinaceae), an abundant species in the high intertidal zone of Prasiola Point, Barkley Sound, British Columbia, Canada. Research focused on investigating the kind of interactions that occur among fronds during growth, discussing its significance for M. cornucopiae in light of what is known for the better studied clonal and non-clonal terrestrial plants. M. cornucopiae develops from holdfasts as a turf, which results in both costs and benefits for thalli, and they are analyzed in relation to the characteristics of its habitat. Additionally, the role of holdfasts and spores for population maintenance, recolonization after disturbance, and frond regeneration after harvesting was also studied. During the growth season for Mazzaella cornucopiae, between late winter and summer, frond density and stand biomass increases simultaneously, hence no self-thinning occurred among fronds as it occurs among individual thalli of actively growing, non-clonal algae. I introduced the use of randomization tests to solve the lack of randomness i n data collection. The decrease of frond size hierarchy observed during the growth season indicates that the growth increment of small fronds per time unit was higher than that of large fronds (symmetric competition model). A n increase of frond crowding, as it occurs during the growth season, involves a cost expressed as reduced net photosynthetic rates; however, frond crowding is beneficial overall. Laboratory and field experiments indicated that high frond densities protect fronds from high desiccation and irradiance and the associated bleaching and tissue loss that spring and summer daytime lowtides bring. Additionally, frond crowding confers protection against the negative effects of wave action on frond survival. Holdfasts are fundamental for population maintenance. They are mostly perennial and constitute the main source of the annual production of fronds; the annual contribution of spores is very low. Finally, experimental pruning of fronds showed that, if commercial harvesting of this species is ever done, a spring collection of all frond biomass, without damaging holdfasts, gives the highest possible biomass yield while allowing frond biomass to be annually renewed.
On Committor Functions in Milestoning
Creators: name: Ji, Xiaojun
name: Wang, Ru
name: Wang, Hao
name: Liu, Wenjian
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: As an optimal one-dimensional reaction coordinate, the committor function not only describes the probability of a trajectory initiated at a phase space point first reaching the product state before reaching the reactant state, but also preserves the kinetics when utilized to run a reduced dynamics model. However, calculating the committor function in high-dimensional systems poses significant challenges. In this paper, within the framework of Milestoning, exact expressions for committor functions at two levels of coarse graining are given, including committor functions of phase space point to point (CFPP) and milestone to milestone (CFMM). When combined with transition kernels obtained from trajectory analysis, these expressions can be utilized to accurately and efficiently compute the committor functions. Furthermore, based on the calculated committor functions, an adaptive algorithm is developed to gradually refine the transition state region. Finally, two model examples are employed to assess the accuracy of these different formulations of committor functions.
Gross misinterpretation of a conditionally solvable eigenvalue equation
Creators: name: Amore, Paolo
name: Fernández, Francisco M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We solve an eigenvalue equation that appears in several papers about a wide range of physical problems. The Frobenius method leads to a three-term recurrence relation for the coefficients of the power series that, under suitable truncation, yields exact analytical eigenvalues and eigenfunctions for particular values of a model parameter. From these solutions some researchers have derived a variety of predictions like allowed angular frequencies, allowed field intensities and the like. We also solve the eigenvalue equation numerically by means of the variational Rayleigh-Ritz method and compare the resulting eigenvalues with those provided by the truncation condition. In this way we prove that those physical predictions are merely artifacts of the truncation condition.
description: arXiv admin note: text overlap with arXiv:2009.07039, arXiv:2008.03376
Active Feature Selection for the Mutual Information Criterion
Creators: name: Schnapp, Shachar
name: Sabato, Sivan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We study active feature selection, a novel feature selection setting in which unlabeled data is available, but the budget for labels is limited, and the examples to label can be actively selected by the algorithm. We focus on feature selection using the classical mutual information criterion, which selects the $k$ features with the largest mutual information with the label. In the active feature selection setting, the goal is to use significantly fewer labels than the data set size and still find $k$ features whose mutual information with the label based on the \emph{entire} data set is large. We explain and experimentally study the choices that we make in the algorithm, and show that they lead to a successful algorithm, compared to other more naive approaches. Our design draws on insights which relate the problem of active feature selection to the study of pure-exploration multi-armed bandits settings. While we focus here on mutual information, our general methodology can be adapted to other feature-quality measures as well. The code is available at the following url: https://github.com/ShacharSchnapp/ActiveFeatureSelection.
description: To appear in AAAI-21
The 4D geometric quantities versus the usual 3D quantities. The resolution of Jackson's paradox
Creators: name: Ivezic, Tomislav
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In this paper we present definitions of different four-dimensional (4D) geometric quantities (Clifford multivectors). New decompositions of the torque N and the angular momentum M (bivectors) into 1-vectors N_{s}, N_{t} and M_{s}, M_{t} respectively are given. The torques N_{s}, N_{t} (the angular momentums M_{s}, M_{t}), taken together, contain the same physical information as the bivector N (the bivector M). The usual approaches that deal with the 3D quantities $\mathbf{E}$, $\mathbf{B}$, $\mathbf{F}$, $\mathbf{L}$, $\mathbf{N}$, etc. and their transformations are objected from the viewpoint of the invariant special relativity (ISR). In the ISR it is considered that 4D geometric quantities are well-defined both theoretically and \emph{experimentally} in the 4D spacetime. This is not the case with the usual 3D quantities. It is shown that there is no apparent electrodynamic paradox with the torque, and that the principle of relativity is naturally satisfied, when the 4D geometric quantities are used instead of the 3D quantities.
description: 13 pages, revtex
Linear polarization constant of $\R^n$
Creators: name: Matolcsi, Mate
Publisher: name: arXiv
Year: 2006
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 46G25, 52A40, 46B07

description: The present work contributes to the determination of the $n$-th linear polarization constant $c_n(H)$ of an $n$-dimensional real Hilbert space $H$. We provide some new lower bounds on the value of $\sup_{\|y\|=1}| x_1,y >... x_n,y |$, where $x_1, ..., x_n$ are unit vectors in $H$. In particular, the results improve an earlier estimate of Marcus. However, the intriguing conjecture $c_n(H)=n^{n/2}$ remains open.
description: 8 pages
From Puppy Love to Pet Peeve: What Causes Second/Successor Dog Syndrome in Assistance-Dog Handlers and Companion-Dog Owners?
Creators: name: Disanayake, M
name: Howell, Tiffani
name: Oliva, JL
Publisher: name: La Trobe
Year: 2024
Subjects: classificationCode: 3109
subject: Zoology
subject: FOS: Biological sciences
classificationCode: 3003
subject: Animal production

description: In a Guide Dog population, there is a higher return rate of handlers’ second dog compared with any prior or subsequent dog pairings. This phenomenon is called Second Dog Syndrome (SDS). Qualitative studies have identified defining features of this syndrome in Guide Dog handlers; however, there has been no peer-reviewed study into the experience of SDS in companion-dog owners or handlers of other assistance dogs. As such, this exploratory study aimed to define the SDS experience in companion-dog owners and assistance-dog handlers. Ten participants, all women, were recruited to participate in focus groups for companion-dog owners (n = 5) and assistance-dog handlers (n = 5). Transcripts were analyzed using thematic analysis. SDS was characterized by a strong bond with the previous dog, ongoing bereavement related to the previous dog loss, negative emotions related to the successor dog, and inability to bond with them. This appeared to be due to comparisons made between the successor and previous dog and unmet expectations of the new dog. For companion-dog owners it was also characterized by a fear of getting hurt again; for assistance-dog owners it was an inability to trust the successor dog, differences in work ability, and a threat to their independence. Time since the loss of the previous dog, awareness of the phenomenon of SDS, and support from the community also influenced the SDS experience. One unexpected finding was that SDS was not exclusively linked to second-paired dogs and that it may be more aptly named “Successor Dog Syndrome.” Given that poor outcomes associated with unsuccessful dog–owner bonding may result in relinquishment, this study provides an important first step to being able to quantify the experience of SDS to develop interventions in the future.
Efficient Model-Agnostic Multi-Group Equivariant Networks
Creators: name: Baltaji, Razan
name: Basu, Sourya
name: Varshney, Lav R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Constructing model-agnostic group equivariant networks, such as equitune (Basu et al., 2023b) and its generalizations (Kim et al., 2023), can be computationally expensive for large product groups. We address this problem by providing efficient model-agnostic equivariant designs for two related problems: one where the network has multiple inputs each with potentially different groups acting on them, and another where there is a single input but the group acting on it is a large product group. For the first design, we initially consider a linear model and characterize the entire equivariant space that satisfies this constraint. This characterization gives rise to a novel fusion layer between different channels that satisfies an invariance-symmetry (IS) constraint, which we call an IS layer. We then extend this design beyond linear models, similar to equitune, consisting of equivariant and IS layers. We also show that the IS layer is a universal approximator of invariant-symmetric functions. Inspired by the first design, we use the notion of the IS property to design a second efficient model-agnostic equivariant design for large product groups acting on a single input. For the first design, we provide experiments on multi-image classification where each view is transformed independently with transformations such as rotations. We find equivariant models are robust to such transformations and perform competitively otherwise. For the second design, we consider three applications: language compositionality on the SCAN dataset to product groups; fairness in natural language generation from GPT-2 to address intersectionality; and robust zero-shot image classification with CLIP. Overall, our methods are simple and general, competitive with equitune and its variants, while also being computationally more efficient.
Cydia crassicornis
Creators: name: Austin, Kyhl A.
name: Rubinoff, Daniel
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Tortricidae
Cydia
Cydia crassicornis

description: Cydia crassicornis (Walsingham)
Presumed extinct
This species is known only from two males collected by R.C.L. Perkins in 1892 at 4000 ft near Kona, Hawaiʻi island (Walsingham 1907). Although possibly a color form of the koa-feeding C. walsinghamii (Butler), Oboyski (2011) considered it distinct based on subtle differences in the male genitalia. Perkins’ field notes for September 1892 indicates that he “collected … by sifting dead leaves at the foot of a big koa tree” (Evenhuis 2007). The forewings are very similar to C. conspicua (Walsingham), but the absence of a “sex pouch” (Zimmerman 1978) on the ventral surface of the male hindwing readily separates it from that species.
description: Published as part of Austin, Kyhl A. & Rubinoff, Daniel, 2023, Rediscoveries and Presumed Extinctions of Hawaiian Leaf-roller Moths (Lepidoptera: Tortricidae), pp. 11-27 in Proceedings of the Hawaiian Entomological Society 55 on page 14, DOI: 10.5281/zenodo.8159762
Fast signal recovery from quadratic measurements
Creators: name: Moscoso, Miguel
name: Novikov, Alexei
name: Papanicolaou, George
name: Tsogka, Chrysoula
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: Probability (math.PR)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We present a novel approach for recovering a sparse signal from cross-correlated data. Cross-correlations naturally arise in many fields of imaging, such as optics, holography and seismic interferometry. Compared to the sparse signal recovery problem that uses linear measurements, the unknown is now a matrix formed by the cross correlation of the unknown signal. Hence, the bottleneck for inversion is the number of unknowns that grows quadratically. The main idea of our proposed approach is to reduce the dimensionality of the problem by recovering only the diagonal of the unknown matrix, whose dimension grows linearly with the size of the problem. The keystone of the methodology is the use of an efficient {\em Noise Collector} that absorbs the data that come from the off-diagonal elements of the unknown matrix and that do not carry extra information about the support of the signal. This results in a linear problem whose cost is similar to the one that uses linear measurements. Our theory shows that the proposed approach provides exact support recovery when the data is not too noisy, and that there are no false positives for any level of noise. Moreover, our theory also demonstrates that when using cross-correlated data, the level of sparsity that can be recovered increases, scaling almost linearly with the number of data. The numerical experiments presented in the paper corroborate these findings.
Imaging of nonlinear materials via the Monotonicity Principle
Creators: name: Mottola, Vincenzo
name: Esposito, Antonio Corbo
name: Piscitelli, Gianpaolo
name: Tamburrino, Antonello
Publisher: name: arXiv
Year: 2023
Subjects: subject: Numerical Analysis (math.NA)
subject: Signal Processing (eess.SP)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Inverse problems, which are related to Maxwell's equations, in the presence of nonlinear materials is a quite new topic in the literature. The lack of contributions in this area can be ascribed to the significant challenges that such problems pose. Retrieving the spatial behaviour of some unknown physical property, from boundary measurements, is a nonlinear and highly ill-posed problem even in the presence of linear materials. Furthermore, this complexity grows exponentially in the presence of nonlinear materials. In the tomography of linear materials, the Monotonicity Principle (MP) is the foundation of a class of non-iterative algorithms able to guarantee excellent performances and compatibility with real-time applications. Recently, the MP has been extended to nonlinear materials under very general assumptions. Starting from the theoretical background for this extension, we develop a first real-time inversion method for the inverse obstacle problem in the presence of nonlinear materials. The proposed method is intendend for all problems governed by the quasilinear Laplace equation, i.e. static problems involving nonlinear materials. In this paper, we provide some preliminary results which give the foundation of our method and some extended numerical examples.
Bootstrapping boundary-localized interactions
Creators: name: Behan, Connor
name: Di Pietro, Lorenzo
name: Lauria, Edoardo
name: van Rees, Balt C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study conformal boundary conditions for the theory of a single real scalar to investigate whether the known Dirichlet and Neumann conditions are the only possibilities. For this free bulk theory there are strong restrictions on the possible boundary dynamics. In particular, we find that the bulk-to-boundary operator expansion of the bulk field involves at most a `shadow pair' of boundary fields, irrespective of the conformal boundary condition. We numerically analyze the four-point crossing equations for this shadow pair in the case of a three-dimensional boundary (so a four-dimensional scalar field) and find that large ranges of parameter space are excluded. However a `kink' in the numerical bounds obeys all our consistency checks and might be an indication of a new conformal boundary condition.
description: 58 pages, 5 figures; v2: references added
Fast Power Curve Approximation for Posterior Analyses
Creators: name: Hagar, Luke
name: Stevens, Nathaniel T.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Bayesian hypothesis tests leverage posterior probabilities, Bayes factors, or credible intervals to inform data-driven decision making. We propose a framework for power curve approximation with such hypothesis tests. We present a fast approach to explore the approximate sampling distribution of posterior probabilities when the conditions for the Bernstein-von Mises theorem are satisfied. We extend that approach to consider segments of such sampling distributions in a targeted manner for each sample size explored. These sampling distribution segments are used to construct power curves for various types of posterior analyses. Our resulting method for power curve approximation is orders of magnitude faster than conventional power curve estimation for Bayesian hypothesis tests. We also prove the consistency of the corresponding power estimates and sample size recommendations under certain conditions.
description: arXiv admin note: text overlap with arXiv:2306.09476
Cydia gypsograpta
Creators: name: Austin, Kyhl A.
name: Rubinoff, Daniel
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Tortricidae
Cydia
Cydia gypsograpta

description: Cydia gypsograpta (Meyrick)
Presumed extinct
This species is known only from the male holotype supposedly collected by R.C.L. Perkins near Honolulu, Oʻahu in 1908 (Meyrick 1932; but see comments below). Oboyski (2011) found it difficult to distinguish from Canavalia -feeding Hawaiian Cydia.
description: Published as part of Austin, Kyhl A. & Rubinoff, Daniel, 2023, Rediscoveries and Presumed Extinctions of Hawaiian Leaf-roller Moths (Lepidoptera: Tortricidae), pp. 11-27 in Proceedings of the Hawaiian Entomological Society 55 on page 14, DOI: 10.5281/zenodo.8159762
Deformed Symmetry in Snyder Space and Relativistic Particle Dynamics
Creators: name: Banerjee, Rabin
name: Kulkarni, Shailesh
name: Samanta, Saurav
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We describe the deformed Poincare-conformal symmetries implying the covariance of the noncommutative space obeying Snyder's algebra. Relativistic particle models invariant under these deformed symmetries are presented. A gauge (reparametrisation) independent derivation of Snyder's algebra from such models is given. The algebraic transformations relating the deformed symmetries with the usual (undeformed) ones are provided. Finally, an alternative form of an action yielding Snyder's algebra is discussed where the mass of a relativistic particle gets identified with the inverse of the noncommutativity parameter.
description: 19 pages; Latex; title changed, 3 new references added and minor changes; to appear in JHEP
Observation of scattering and absorption centers in lead fluoride crystals
Creators: name: Achenbach, Patrick
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: For the first time, lead fluoride is used as a fast and compact material in electromagnetic calorimetry. Excellent optical and mechanical properties of the pure Cherenkov crystals are necessary for the A4 collaboration to perform a measurement of the nucleon's strange form factors. Visible scattering and absorption centers as well as surface damages have been investigated to characterize the quality of more than one thousand crystals. Besides, transmittance measurements have been performed on all crystals to reveal absorption bands produced by intrinsic or impurity related point-structure defects. As a consequence, 89 crystals had to be replaced by the Chinese manufacturer SICCAS.
description: LaTeX, 6 pages, 6 figures
Cydia obliqua
Creators: name: Austin, Kyhl A.
name: Rubinoff, Daniel
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Tortricidae
Cydia
Cydia obliqua

description: Cydia obliqua (Walsingham)
Presumed extinct
This species is known from three female specimens collected at Hualālai (5000 ft) and Kona (4000 ft) on Hawaiʻi island by R.C.L. Perkins in 1892. Oboyski (2011) considered it possibly just an extreme color form of the widespread and polymorphic C. plicatum (Walsingham), but refrained from synonymizing it because of significant differences in the female genitalia. The collection date given for the two female types from Hualālai (5 viii 1892) corresponds to a journal entry in which Perkins wrote, “there were two Tortricids on Koa” (Evenhuis 2007).
description: Published as part of Austin, Kyhl A. & Rubinoff, Daniel, 2023, Rediscoveries and Presumed Extinctions of Hawaiian Leaf-roller Moths (Lepidoptera: Tortricidae), pp. 11-27 in Proceedings of the Hawaiian Entomological Society 55 on page 14, DOI: 10.5281/zenodo.8159762