cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Scattering theory for quantum fields with indefinite metric
Creators: name: Albeverio, S.
name: Gottschalk, H.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 81T05, 81T08

description: In this work, we discuss the scattering theory of local, relativistic quantum fields with indefinite metric. Since the results of Haag--Ruelle theory do not carry over to the case of indefinite metric, we propose an axiomatic framework for the construction of in- and out- states, such that the LSZ asymptotic condition can be derived from the assumptions. The central mathematical object for this construction is the collection of mixed vacuum expectation values of local, in- and out- fields, called the ``form factor functional'', which is required to fulfill a Hilbert space structure condition. Given a scattering matrix with polynomial transfer functions, we then construct interpolating, local, relativistic quantum fields with indefinite metric, which fit into the given scattering framework.
Energy-Efficient Fixed-Gain AF Relay Assisted OFDM with Index Modulation
Creators: name: Zhou, Jiusi
name: Dang, Shuping
name: Shihada, Basem
name: Alouini, Mohamed-Slim
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: Information Theory (cs.IT)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: To broaden the application scenario and reduce energy consumption, we propose an energy-efficient fixed-gain (FG) amplify-and-forward (AF) relay assisted orthogonal frequency-division multiplexing with index modulation (OFDM-IM) scheme in this letter. The proposed system needs neither instantaneous channel state information (CSI) nor complicated processing at the relay node. It operates based on the power allocation scheme that minimizes the sum of transmit power at both source and relay node, given an outage probability constraint. Through a series of problem transformation and simplification, we convert the original power allocation problem to its relaxed version and solve it using convex programming techniques. To reveal the computing efficiency of the proposed power allocation scheme, we analyze its computational complexity. Numerical simulations substantiate that the proposed optimization scheme has a neglectable loss compared with the brute force search, but the computational complexity can be considerably reduced.
LABOUR SUPPLY AND OFF-FARM WORK BY FARMERS: THEORY AND ESTIMATION
Creators: name: Robinson, Chris
name: McMahon, Pat J.
name: Quiggin, John C.
name: Robinson, Chris
name: McMahon, Pat J.
name: Quiggin, John C.
Publisher: name: Unknown
Year: 1982
Subjects: Labor and Human Capital

description: Off-farm employment has become increasingly important as an aspect of resource adjustment and a source of income in Australian agriculture. However, it is surprising that there is a paucity of work on this topic reported in the agricultural economics literature. Therefore, we have drawn upon recent developments in labour economics in order to investigate off-farm employment in Australia. A conceptual model of the allocation of a farmer's labour between farm and off-farm work is developed and applied to cross-sectional data from the Australian Agricultural and Grazing Industries Survey. A Tobit maximum likelihood procedure is utilised to test the influences of the life cycle, level of human capital, wealth, non-wage income and farm income on the off-farm labour supply of farmers.
Zeugnis, Dienst, Einheit in orthodoxer Sicht
Creators: name: Slenczka, Reinhard
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 11 Nr. 2 (1962): Ökumenische Rundschau, Band 11, Heft 2
Surprises from the search for quark-gluon plasma? When was quark-gluon plasma seen?
Creators: name: Weiner, Richard M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The historical context of the recent results from high energy heavy ion reactions devoted to the search of quark-gluon plasma (QGP) is reviewed, with emphasis on the surprises encountered. The evidence for QGP from heavy ion reactions is compared with that available from particle reactions.
description: 43 pages, 8 figures, Corrected typos and minor stylistic changes
Comment on "Protective measurements and Bohm's trajectories" by Y.Aharonov, B.G.Englert, and M.O.Scully
Creators: name: Drezet, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the above paper [1], it is claimed that Bohm's mechanics can be challenged by a simple gedanken experiment involving a protecting measurement. Here we show that this gedanken experiment can be justified without problem and without contradicting the axiom attributing a physical meaning to the Bohmian trajectorie
description: Phys.Lett.A 350, 416 (2006). 3 pages no figure
Shaping nanoscale magnetic domain memory in exchange-coupled ferromagnets by field cooling
Creators: name: Chesnel, Karine
name: Safsten, Alex
name: Rytting, Matthew
name: Fullerton, Eric E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The advance of magnetic nanotechnologies relies on detailed understanding of nanoscale magnetic mechanisms in materials. Magnetic domain memory (MDM), i.e., the tendency for magnetic domains to repeat the same pattern during field-cycling, is important to many technologies including magnetic recording developments. We show coherent x-ray magnetic scattering studies unveiling MDM in [Co/Pd]/IrMn films. When illuminated by coherent x-rays, the magnetic domains in the [Co/Pd] multilayer produce a speckle pattern unique to their specific nanoscale configuration. By cross-correlating such speckle patterns throughout the magnetization loop, we measure the MDM. When cooled below its blocking temperature, the film exhibits up to 100% MDM, induced by exchange-couplings with the IrMn layer. Furthermore, the degree of MDM drastically depends on cooling conditions. If the film is cooled under moderate fields, MDM is high throughout the entire magnetization loop. If the film is cooled under nearly saturating field, MDM vanishes, except at nucleation and saturation
Pair-beam propagation in a magnetised plasma for modelling the polarized radiation emission from gamma-ray bursts in laboratory astrophysics experiments
Creators: name: Sinha, Ujjwal
name: Kumar, Naveen
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The propagation of a relativistic electron-positron beam in a magnetized electron-ion plasma is studied, focusing on the polarization of the radiation generated in this case. Special emphasis is laid on investigating the polarization of the generated radiation for a range of beam-plasma parameters, transverse and longitudinal beam sizes, and the external magnetic fields. Our results not only help in understanding the high degrees of circular polarization observed in gamma-rays bursts but they also help in distinguishing the different modes associated with the filamentation dynamics of the pair-beam in laboratory astrophysics experiments.
Lifting smooth curves over invariants for representations of compact Lie groups, III
Creators: name: Kriegl, Andreas
name: Losik, Mark
name: Michor, Peter W.
name: Rainer, Armin
Publisher: name: arXiv
Year: 2005
Subjects: subject: Representation Theory (math.RT)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 22E45; 20F55

description: Any sufficiently often differentiable curve in the orbit space $V/G$ of a real finite-dimensional orthogonal representation $G \to O(V)$ of a finite group $G$ admits a differentiable lift into the representation space $V$ with locally bounded derivative. As a consequence any sufficiently often differentiable curve in the orbit space $V/G$ can be lifted twice differentiably. These results can be generalized to arbitrary polar representations. Finite reflection groups and finite rotation groups in dimensions two and three are discussed in detail.
description: 19 pages, Latex
Liouville theory without an action
Creators: name: Pakman, Ari
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that the crossing symmetry of the four-point function in the Liouville conformal field theory on the sphere contains more information than what was hitherto considered. Under certain assumptions, it provides the special structure constants that were previously computed perturbatively and allows to solve the theory without using the Liouville interaction.
description: 9 pages
Decay of correlations in nearest-neighbor self-avoiding walk, percolation, lattice trees and animals
Creators: name: Hara, Takashi
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 82B27, 82B41, 82B43, 82C41 (Primary) 60K35 (Secondary)

description: We consider nearest-neighbor self-avoiding walk, bond percolation, lattice trees, and bond lattice animals on ${\mathbb{Z}}^d$. The two-point functions of these models are respectively the generating function for self-avoiding walks from the origin to $x\in{\mathbb{Z}}^d$, the probability of a connection from the origin to $x$, and the generating functions for lattice trees or lattice animals containing the origin and $x$. Using the lace expansion, we prove that the two-point function at the critical point is asymptotic to $\mathit{const.}|x|^{2-d}$ as $|x|\to\infty$, for $d\geq 5$ for self-avoiding walk, for $d\geq19$ for percolation, and for sufficiently large $d$ for lattice trees and animals. These results are complementary to those of [Ann. Probab. 31 (2003) 349--408], where spread-out models were considered. In the course of the proof, we also provide a sufficient (and rather sharp if $d>4$) condition under which the two-point function of a random walk on ${\mathbb{Z}^d}$ is asymptotic to $\mathit{const.}|x|^{2-d}$ as $|x|\to\infty$.
description: Published in at http://dx.doi.org/10.1214/009117907000000231 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Partly Divisible Probability Distributions
Creators: name: Albeverio, S.
name: Gottschalk, H.
name: Wu, J. -L.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 42A85; 60B15

description: Given a probability distribution $μ$ a set $Λ(μ)$ of positive real numbers is introduced, so that $Λ(μ)$ measures the "divisibility" of $μ$. The basic properties of $Λ(μ)$ are described and examples of probability distributions are given, which exhibit the existence of a continuum of situations interpolating the extreme cases of infinitely and minimally divisible probability distributions.
description: 11 pages
Large Scale Distribution of Galaxies in The Field HS 47.5-22. II. Observational Data Analysis
Creators: name: Grokhovskaya, Aleksandra
name: Dodonov, Sergei N.
name: Movsessian, T. A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The results of the study of the large-scale distribution of galaxies up to z ~0.8 in the field HS 47.5-22 on the basis of photometric data of the 1-meter Schmidt telescope of the BAO NAS Armenia are presented. The full sample contains 28,398 galaxies. Candidates for large-scale structures were determined using two independent methods for reconstructing density contrast maps in 57 narrow slices of the three-dimensional distribution of galaxies: adaptive aperture algorithm with smoothing and 2D Voronoi tessellation. We have identified more than 250 statistically significant overdense structures. The obtained results demonstrate a wide range of overdense structures over the full range of redshifts up to z ~0.8.
description: Accepted for publication in Astrophysical Bulletin, 16 pages, 14 figures, 2 tabels
Optimal retrofit strategy determination for bridges using decision analysis
Creators: name: Khan, Saqib A.
Publisher: name: University of British Columbia
Year: 2009

description: With our increased knowledge about seismicity and risks related to earthquakes, there is a greater need for retrofitting deficient structures to ensure the functioning of a transportation network and to minimize the life and economic loss associated with catastrophic events. Given the scarcity of funds, the decision maker should try to determine the optimal level of retrofit for a structure and the priorities among various candidates. A decision analysis methodology is thus proposed and demonstrated through two example bridges in order to determine the most preferable level of retrofit and the retrofit order for the two candidates. The decision alternative minimizing the total cost of the structure over its life is the best retrofit strategy while the bridge with the lower cost-to- benefit ratio should be retrofitted first. Seismic assessment o f the Colquitz river south structure was performed in terms of three different levels of seismicity. Various earthquake records were scaled to match the site-specific spectra corresponding to each level of seismicity. These records were then used to drive the non-linear dynamic analysis of the bridge pier. Overall damage states for the bridge were determined based on damage index values for the pier and expert judgement for other bridge components corresponding to various pre-defined levels of retrofit. The structural damage was then translated into dollar damage and this information was used in the decision analysis algorithm as consequence costs. An expected annual cost of future damage was then calculated and converted to present worth for each retrofit level. The estimated retrofit costs and the present value of future damages were then added to find the total expected cost for each decision alternative. Sensitivity analyses were carried out to examine the variations in decision outcome due to changes in different input parameters. Also, the effectiveness of decision analysis techniques not employing probability and risk attributes was briefly examined. For the Interurban overpass, it was assumed that the safety level retrofit would be the optimal strategy. Cost-to-benefit ratios for the two structures were then calculated corresponding to the optimal retrofit decision for each, thus determining the order of retrofit.
Off-shell BRST-VSUSY superalgebra for D=4 BF theories in the superconnection formalism
Creators: name: Aidaoui, A.
name: Tahiri, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose the superconnection formalism to construct the off-shell BRST-VSUSY superalgebra for D=4 BF theories. The method is based on the natural introduction of physical fields as well as auxiliary fields via superconnections and their associated supercurvatures defined on a superspace. We also give a prescription to build the off-shell BRST-VSUSY exact quantum action.
description: Latex, 13 pages, no figures, comments and references added
Quantum-state filtering applied to the discrimination of Boolean functions
Creators: name: Bergou, Janos A.
name: Hillery, Mark
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum state filtering is a variant of the unambiguous state discrimination problem: the states are grouped in sets and we want to determine to which particular set a given input state belongs.The simplest case, when the N given states are divided into two subsets and the first set consists of one state only while the second consists of all of the remaining states, is termed quantum state filtering. We derived previously the optimal strategy for the case of N non-orthogonal states, {|ψ_{1} >, ..., |ψ_{N} >}, for distinguishing |ψ_1 > from the set {|ψ_2 >, ..., |ψ_N >} and the corresponding optimal success and failure probabilities. In a previous paper [PRL 90, 257901 (2003)], we sketched an appplication of the results to probabilistic quantum algorithms. Here we fill in the gaps and give the complete derivation of the probabilstic quantum algorithm that can optimally distinguish between two classes of Boolean functions, that of the balanced functions and that of the biased functions. The algorithm is probabilistic, it fails sometimes but when it does it lets us know that it did. Our approach can be considered as a generalization of the Deutsch-Jozsa algorithm that was developed for the discrimination of balanced and constant Boolean functions.
description: 8 pages
A Bayesian view on Faraday rotation maps - Seeing the magnetic power spectra in galaxy clusters
Creators: name: Vogt, Corina
name: Ensslin, Torsten A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a Bayesian maximum likelihood analysis of Faraday rotation measure (RM) maps of extended radio sources to determine magnetic field power spectra in clusters of galaxies. Using this approach, it is possible to determine the uncertainties in the measurements. We apply this approach to the RM map of Hydra A and derive the power spectrum of the cluster magnetic field. For Hydra A, we measure a spectral index of -5/3 over at least one order of magnitude implying Kolmogorov type turbulence. We find a dominant scale of about 3 kpc on which the magnetic power is concentrated, since the magnetic autocorrelation length is lambda_B = 3 +/- 0.5 kpc. Furthermore, we investigate the influences of the assumption about the sampling volume (described by a window function) on the magnetic power spectrum. The central magnetic field strength was determined to be about 7 +/- 2 muG for the most likely geometries.
description: 11 pages, 8 figures, accepted for publication in A&A
Anyone here? Smart embedded low-resolution omnidirectional video sensor to measure room occupancy
Creators: name: Callemein, Timothy
name: Van Beeck, Kristof
name: Goedemé, Toon
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: In this paper, we present a room occupancy sensing solution with unique properties: (i) It is based on an omnidirectional vision camera, capturing rich scene info over a wide angle, enabling to count the number of people in a room and even their position. (ii) Although it uses a camera-input, no privacy issues arise because its extremely low image resolution, rendering people unrecognisable. (iii) The neural network inference is running entirely on a low-cost processing platform embedded in the sensor, reducing the privacy risk even further. (iv) Limited manual data annotation is needed, because of the self-training scheme we propose. Such a smart room occupancy rate sensor can be used in e.g. meeting rooms and flex-desks. Indeed, by encouraging flex-desking, the required office space can be reduced significantly. In some cases, however, a flex-desk that has been reserved remains unoccupied without an update in the reservation system. A similar problem occurs with meeting rooms, which are often under-occupied. By optimising the occupancy rate a huge reduction in costs can be achieved. Therefore, in this paper, we develop such system which determines the number of people present in office flex-desks and meeting rooms. Using an omnidirectional camera mounted in the ceiling, combined with a person detector, the company can intelligently update the reservation system based on the measured occupancy. Next to the optimisation and embedded implementation of such a self-training omnidirectional people detection algorithm, in this work we propose a novel approach that combines spatial and temporal image data, improving performance of our system on extreme low-resolution images.
Some fractional integral and derivative formulas revisited
Creators: name: Gonzales-Santander, Juan Luis
name: Mainardi, Francesco
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics
subject: 26A33

description: In the most common literature about fractional calculus, we find that $_{a}D_{t}^{α}f\left( t\right) =\,_{a}I_{t}^{-α}f\left( t\right) $ is assumed implicitly in the tables of fractional integrals and derivatives. However, this is not straightforward from the definitions of $_{a}I_{t}^{α}f\left( t\right) $ and $_{a}D_{t}^{α}f\left( t\right) $. In this sense, we prove that $_{0}D_{t}^{α}f\left( t\right) =\,_{0}I_{t}^{-α}f\left( t\right) $ is true for $f\left( t\right) =t^{ν-1}\log t$, and $f\left( t\right) =e^{λt}$, despite the fact that these derivations are highly non-trivial. Moreover, the corresponding formulas for $_{-\infty }D_{t}^{α}\left\vert t\right\vert ^{-δ}$ and $_{-\infty }I_{t}^{α}\left\vert t\right\vert ^{-δ}$ found in the literature are incorrect; thus, we derive the correct ones, proving in turn that $_{-\infty }D_{t}^{α}\left\vert t\right\vert ^{-δ}=\,_{-\infty }I_{t}^{-α}\left\vert t\right\vert ^{-δ}$ holds true
description: 17 pages
Efficient Monte Carlo methods for continuum radiative transfer
Creators: name: Juvela, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We discuss the efficiency of Monte Carlo methods in solving continuum radiative transfer problems. The sampling of the radiation field and convergence of dust temperature calculations in the case of optically thick clouds are both studied. For spherically symmetric clouds we find that the computational cost of Monte Carlo simulations can be reduced, in some cases by orders of magnitude, with simple importance weighting schemes. This is particularly true for models consisting of cells of different sizes for which the run times would otherwise be determined by the size of the smallest cell. We present a new idea of extending importance weighting to scattered photons. This is found to be useful in calculations of scattered flux and could be important for three-dimensional models when observed intensity is needed only for one general direction of observations. Convergence of dust temperature calculations is studied for models with optical depths 10-10000. We examine acceleration methods where radiative interactions inside a cell or between neighbouring cells are treated explicitly. In optically thick clouds with strong self-coupling between dust temperatures the run times can be reduced by more than one order of magnitude. The use of a reference field was also examined. This eliminates the need for repeating simulation of constant sources (e.g., background radiation) after the first iteration and significantly reduces sampling errors. The applicability of the methods for three-dimensional models is discussed.
description: submitted to A&A, 19 pages
A consensus-based approach for parameter and state estimation of agro-hydrological system
Creators: name: Yin, Xunyuan
name: Bo, Song
name: Liu, Jinfeng
name: Huang, Biao
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The development of advanced closed-loop irrigation systems requires accurate soil moisture information. In this work, we address the problem of soil moisture estimation for the agro-hydrological systems in a robust and reliable manner. A nonlinear state-space model is established based on the discretization of the Richards equation to describe the dynamics of agro-hydrological systems. We consider that model parameters are unknown and need to be estimated together with the states simultaneously. We propose a consensus-based estimation mechanism, which comprises two main parts: 1) a distributed extended Kalman filtering algorithm used to estimate several model parameters; and 2) a distributed moving horizon estimation algorithm used to estimate the state variables and one remaining model parameter. Extensive simulations are conducted, and comparisons with existing methods are made to demonstrate the effectiveness and superiority of the proposed approach. In particular, the proposed approach can provide accurate soil moisture estimate even when poor initial guesses of the parameters and the states are used, which can be challenging to be handled using existing algorithms.
Formation of a Partially-Screened Inner Acceleration Region in Radio Pulsars: Drifting Subpulses and Thermal X-Ray Emission from Polar Cap Surface
Creators: name: Gil, Janusz
name: Melikidze, George
name: Zhang, Bing
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The subpulse drifting phenomenon in pulsar radio emission is considered within the partially screened inner gap model, in which the sub-Goldreich-Julian thermionic flow of iron ions or electrons coexists with the spark-associated electron-positron plasma flow. We derive a simple formula that relates the thermal X-ray luminosity $L_{\rm x}$ from the spark-heated polar cap and the \EB subpulse periodicity $\hat{P}_3$ (polar cap carousel time). For PSRs B0943+10 and B1133+16, the only two pulsars for which both $\hat{P}_3$ and $L_{\rm x}$ are known observationally, this formula holds well. For a few other pulsars, for which only one quantity is measured observationally, we predict the value of the other quantity and propose relevant observations that can confirm or discard the model. Then we further study the detailed physical conditions that allow such partially screened inner gap to form. By means of the condition $T_{\rm c}/T_{\rm s}>1$ (where $T_{\rm c}$ is the critical temperature above which the surface delivers a thermal flow to adequately supply the corotation charge density, and $T_{\rm s}$ is the actual surface temperature), it is found that a partially-screened gap (PSG) can be formed given that the near surface magnetic fields are very strong and curved. We consider both curvature radiation (CR) and resonant inverse Compton scattering (ICS) to produce seed photons for pair production, and find that the former is the main agency to produce gamma-rays to discharge PSG.
A five-dimensional Lorenz-type model near the temperature of maximum density
Creators: name: Rastegin, Alexey E.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: The current study formulates a convective model of the Lorenz type near the temperature of maximum density. The existence of this temperature actualizes water dynamics in temperate lakes. There is a conceptual interest what this feature induces in Lorenz-type models. The consideration starts with the zero coefficient of thermal expansion. Other steps are like famous Tritton's approach to derive the Lorenz model. This allows us to reduce difficulties with a selection of Galerkin functions. The analysis focuses on changes induced by zeroing the coefficient of thermal expansion. It results in a five-dimensional Lorenz-type model, whose equations are all nonlinear. The new model reiterates many features of the standard Lorenz model. The nontrivial critical points appear, when the zero critical point becomes unstable. The nontrivial critical points correspond to two possible directions of fluid flow. Phase trajectories of the new model were studied numerically. The results are similar to the known five-dimensional extensions of the Lorenz model.
description: 13 pages, five figures. Published as a contribution to Special Collection: K. R. Sreenivasan: A Tribute on the occasion of his 75th Birthday
Dual Stream Graph Transformer Fusion Networks for Enhanced Brain Decoding
Creators: name: Goene, Lucas
name: Mehrkanoon, Siamak
Publisher: name: arXiv
Year: 2024
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences
subject: I.2; I.5

description: This paper presents the novel Dual Stream Graph-Transformer Fusion (DS-GTF) architecture designed specifically for classifying task-based Magnetoencephalography (MEG) data. In the spatial stream, inputs are initially represented as graphs, which are then passed through graph attention networks (GAT) to extract spatial patterns. Two methods, TopK and Thresholded Adjacency are introduced for initializing the adjacency matrix used in the GAT. In the temporal stream, the Transformer Encoder receives concatenated windowed input MEG data and learns new temporal representations. The learned temporal and spatial representations from both streams are fused before reaching the output layer. Experimental results demonstrate an enhancement in classification performance and a reduction in standard deviation across multiple test subjects compared to other examined models.
description: 6 pages
A Programming Model for Hybrid Workflows: combining Task-based Workflows and Dataflows all-in-one
Creators: name: Ramon-Cortes, Cristian
name: Lordan, Francesc
name: Ejarque, Jorge
name: Badia, Rosa M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: This paper tries to reduce the effort of learning, deploying, and integrating several frameworks for the development of e-Science applications that combine simulations with High-Performance Data Analytics (HPDA). We propose a way to extend task-based management systems to support continuous input and output data to enable the combination of task-based workflows and dataflows (Hybrid Workflows from now on) using a single programming model. Hence, developers can build complex Data Science workflows with different approaches depending on the requirements. To illustrate the capabilities of Hybrid Workflows, we have built a Distributed Stream Library and a fully functional prototype extending COMPSs, a mature, general-purpose, task-based, parallel programming model. The library can be easily integrated with existing task-based frameworks to provide support for dataflows. Also, it provides a homogeneous, generic, and simple representation of object and file streams in both Java and Python; enabling complex workflows to handle any data type without dealing directly with the streaming back-end.
description: Accepted in Future Generation Computer Systems (FGCS). Licensed under CC-BY-NC-ND
Designing Pre-training Datasets from Unlabeled Data for EEG Classification with Transformers
Creators: name: Bary, Tim
name: Macq, Benoit
Publisher: name: arXiv
Year: 2024
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: Transformer neural networks require a large amount of labeled data to train effectively. Such data is often scarce in electroencephalography, as annotations made by medical experts are costly. This is why self-supervised training, using unlabeled data, has to be performed beforehand. In this paper, we present a way to design several labeled datasets from unlabeled electroencephalogram (EEG) data. These can then be used to pre-train transformers to learn representations of EEG signals. We tested this method on an epileptic seizure forecasting task on the Temple University Seizure Detection Corpus using a Multi-channel Vision Transformer. Our results suggest that 1) Models pre-trained using our approach demonstrate significantly faster training times, reducing fine-tuning duration by more than 50% for the specific task, and 2) Pre-trained models exhibit improved accuracy, with an increase from 90.93% to 92.16%, as well as a higher AUC, rising from 0.9648 to 0.9702 when compared to non-pre-trained models.
description: 6 pages, 4 figures, 5 tables, 22nd IEEE Mediterranean Electrotechnical Conference (MELECON 2024)
Analysing Competitiveness of the Hungarian Agro-Food Chains
Creators: name: Feher, Istvan
name: Papp, Zsolt
name: Feher, Istvan
name: Papp, Zsolt
Publisher: name: Unknown
Year: 2002
Subjects: subject: Agribusiness
subject: competitiveness
subject: strategy
subject: accession
subject: technology development
subject: investment

description: Based on the Policy Analysis Matrix (PAM) approach this paper provides an assessment of the competitive position of the Hungarian agro-food industry in view of EU integration. The situation in the food processing sector is assessed with the use of actual cost data from representative Hungarian companies. The paper presents an assessment of the current situation prior to EU integration as well as a future outlook under various scenarios with regard to the expected policy environment and the rate of technological change. The actual measurement of competitiveness in this study focuses mainly on Private Resource Cost (PRC) which indicates competitiveness under real market conditions and Domestic Resource Cost (DRC) which gives an assessment on the social or economic efficiency of an activity, i.e. whether domestic resources are really used efficiently in current production. In the food processing sector 21 different food products have been investigated which fall into four industries: meat, poultry, dairy, and fruits and vegetables. Under current conditions only some products are competitive in private terms. The situation would improve after EU integration especially for poultry, fruits and vegetables, because agricultural policy conditions are more favourable under the CAP. If additional FDI(Foreign Direct Investments) would flow into the country after EU membership, this would boost profitability. As far as DRC values are concerned, it must be stated that only some of the production activities are clearly efficient. Dairy, fruits and vegetables, and roast goose production show relatively weak social competitiveness, while other poultry and fruit and vegetables products are more favourable from the economic point of view. As EU policies provide on average higher protection levels, the competitiveness of Hungarian food processing on world markets would deteriorate for most products after EU accession. However, these effects can be offset by additional technological change due to FDI inflows or otherwise induced technological progress.
High Spectral Resolution Observations of the Massive Stars in the Galactic Center
Creators: name: Tanner, Angelle
name: Figer, Donald F.
name: Najarro, Paco
name: Kudritzki, Rolf P.
name: Gilmore, Diane
name: Morris, Mark
name: Becklin, E. E.
name: McLean, Ian S.
name: Gilbert, Andrea M.
name: Graham, James R.
name: Larkin, James E.
name: Levenson, N. A.
name: Teplitz, Harry I.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present high-resolution near-infrared spectra, obtained with the NIRSPEC spectrograph on the W. M. Keck II Telescope, of a collection of hot, massive stars within the central 25 arcseconds of the Galactic center. We have identified a total of twenty-one emission-line stars, seven of which are new radial velocity detections with five of those being classified as He I emission-line stars for the first time. These stars fall into two categories based on their spectral properties: 1) those with narrow 2.112, 2.113 micron He I doublet absorption lines, and 2) those with broad 2.058 micron He I emission lines. These data have the highest spectral resolution ever obtained for these sources and, as a result, both components of the absorption doublet are separately resolved for the first time. We use these spectral features to measure radial velocities. The majority of the measured radial velocities have relative errors of 20 kms, smaller than those previously obtained with proper-motion or radial velocity measurements for similar stellar samples in the Galactic center. The radial velocities estimated from the He I absorption doublet are more robust than those previously estimated from the 2.058 micron emission line, since they do not suffer from confusion due to emission from the surrounding ISM. Using this velocity information, we agree that the stars are orbiting in a somewhat coherent manner but are not as defined into a disk or disks as previously thought. Finally, multi-epoch radial velocity measurements for IRS 16NE show a change in its velocity presumably due to an unseen stellar companion.
description: ApJ accepted, 42 pages, 16 figures
The Phong Surface: Efficient 3D Model Fitting using Lifted Optimization
Creators: name: Shen, Jingjing
name: Cashman, Thomas J.
name: Ye, Qi
name: Hutton, Tim
name: Sharp, Toby
name: Bogo, Federica
name: Fitzgibbon, Andrew William
name: Shotton, Jamie
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Realtime perceptual and interaction capabilities in mixed reality require a range of 3D tracking problems to be solved at low latency on resource-constrained hardware such as head-mounted devices. Indeed, for devices such as HoloLens 2 where the CPU and GPU are left available for applications, multiple tracking subsystems are required to run on a continuous, real-time basis while sharing a single Digital Signal Processor. To solve model-fitting problems for HoloLens 2 hand tracking, where the computational budget is approximately 100 times smaller than an iPhone 7, we introduce a new surface model: the `Phong surface'. Using ideas from computer graphics, the Phong surface describes the same 3D shape as a triangulated mesh model, but with continuous surface normals which enable the use of lifting-based optimization, providing significant efficiency gains over ICP-based methods. We show that Phong surfaces retain the convergence benefits of smoother surface models, while triangle meshes do not.
Maps of zeroes of the grand canonical partition function in a statistical model of high energy collisions
Creators: name: Brambilla, M.
name: Giovannini, A.
name: Ugoccioni, R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Theorems on zeroes of the truncated generating function in the complex plane are reviewed. When examined in the framework of a statistical model of high energy collisions based on the negative binomial (Pascal) multiplicity distribution, these results lead to maps of zeroes of the grand canonical partition function which allow to interpret in a novel way different classes of events in pp collisions at LHC c.m. energies.
description: 17 pages, figures (ps included); added references, some figures enlarged. To appear in J. Phys. G
Krüger, Hanfried (Hrsg.), Bis an das Ende der Erde
Creators: name: Stratenwerth, Gerhard
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 11 Nr. 1 (1962): Ökumenische Rundschau, Band 11, Heft 1
Relative Forecasting and Hedging Efficiency of Agricultural Futures Markets in the European Union: Evidence for Slaughter Hog Contracts
Creators: name: Loy, Jens-Peter
name: Loy, Jens-Peter
Publisher: name: Unknown
Year: 2002
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: Futures
subject: Pigs
subject: Market Efficiency
subject: Hedging

description: The paper aims at analyzing the potentials for reducing income risk and income variation for slaughter hog producers in Germany and Holland by participating at futures markets in Amsterdam or Hannover. The relative market and hedging efficiency for the Amsterdam stock exchange markets is tested and the optimal hedge ratio is derived for minimizing risk and variance of slaughter hog gross margins (income). Relative market efficiency and a significant impact of hedging on income risk and variance can not be rejected. The results show that the optimal hedge ratio is smaller for variance compared to risk minimizing hedging strategy.
Real-time Embedded Person Detection and Tracking for Shopping Behaviour Analysis
Creators: name: Schrijvers, Robin
name: Puttemans, Steven
name: Callemein, Timothy
name: Goedemé, Toon
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Shopping behaviour analysis through counting and tracking of people in shop-like environments offers valuable information for store operators and provides key insights in the stores layout (e.g. frequently visited spots). Instead of using extra staff for this, automated on-premise solutions are preferred. These automated systems should be cost-effective, preferably on lightweight embedded hardware, work in very challenging situations (e.g. handling occlusions) and preferably work real-time. We solve this challenge by implementing a real-time TensorRT optimized YOLOv3-based pedestrian detector, on a Jetson TX2 hardware platform. By combining the detector with a sparse optical flow tracker we assign a unique ID to each customer and tackle the problem of loosing partially occluded customers. Our detector-tracker based solution achieves an average precision of 81.59% at a processing speed of 10 FPS. Besides valuable statistics, heat maps of frequently visited spots are extracted and used as an overlay on the video stream.
WTO's Agreement on Agriculture: Implications for Trade, Sustained Agricultural Growth and Poverty Alleviation
Creators: name: Chishti, Anwar F.
name: Malik, Waqar
name: Chishti, Anwar F.
name: Malik, Waqar
Publisher: name: Unknown
Year: 2002
Subjects: International Relations/Trade

description: A theory-based graphical analysis of WTO's trade liberalization policies (opening of close-economy to international trade and cuts in price-supports, import-tariffs and export-subsidies) suggests that most of such policies would yield net social gains to the society, as a whole. The adverse effects and losses in producer surpluses of some of the policies would be balanced out by greater gains in consumer surpluses and vice versa. Losses in producer surpluses due to cuts in price supports and import tariffs are also expected to be partially subsided by reductions in export subsidies mainly granted by the USA and EU; hence, policies need to be enforced, not in isolation, but in a simultaneous fashion. Trade liberalization would help minimize control of individuals on trade, leave less room for individual policy makers, tax collectors and interest groups to exploit situations in their own interest and lead the economy to be run in accordance with the supply and demand forces based on the last lasting general tendency of human nature. This would help to achieve a sustainable and stable agricultural growth; however, more durable sustained growth would depend as how effectively trade liberalization is pursued and enforced the world over. Opening of closed economy for exportables, and withdrawal of export subsidies by foreign exporters would be proproducers and would directly contribute to poverty alleviation. Opening of economy for importables, withdrawal of price supports and tariff-cuts on imports would yield savings to consumers and would positively contribute towards poverty reduction.
Influence of vertical alignment on perception of horizontal curvature
Creators: name: Bidulka, Shaun David
Publisher: name: University of British Columbia
Year: 2009

description: Since most of the driver's required information is obtained visually, the importance of the driver receiving precise visual cues from the road environment cannot be overstated. If the visual cues are confusing or in any way cause the driver to incorrectly assess the approaching road environment, the crash risk of the driver may increase. Of particular concern are the perceptual problems induced by superimposing horizontal and vertical curves. To investigate the effect of overlapping vertical alignment on the perceived horizontal curvature, dynamic and static computer generated three-dimensional presentations of the driver's view of a road were created. Phase I of the experiment collected qualitative data to test the hypothesis that overlapping crest curves made horizontal curvature appear sharper and overlapping sag curves made horizontal curvature appear less sharp. Phase II of the experiment quantified the perceived radius Rp. The statistical analysis of the Phase II data showed that horizontal curvature appeared consistently sharper when it was overlapped with a crest curve and consistently flatter when it was overlapped with a sag curve at a level of significance α = 5%. Overall this "optical illusion" effect was more prevalent when sag curves were overlapping horizontal curves. Several regression equations that predict driver perception of horizontal curvature were also developed. For sag vertical curves, the actual radius Ract, the turning direction, and the vertical curve parameter A affected the perceived radius Rp. However, for crest curves, the only geometric parameter found to be a significant predictor of Rp was the actual horizontal curve radius Ract.
International Quota Transfer and Intermediate Goods
Creators: name: Aldanondo, Ana Maria
name: Puertolas, Javier
name: Aldanondo, Ana Maria
name: Puertolas, Javier
Publisher: name: Unknown
Year: 2002
Subjects: subject: International Relations/Trade
subject: Production quota
subject: international trade
subject: intermediate goods

description: In this paper we use a general equilibrium model to examine the effects of international quota transfer when a quota restricts world commodity production whilst the trade in an intermediate good is not regulated. The analysis shows that, when the quota regime is not internationally transferable, intermediate input trade substitutes for final good trade. In these circumstances, the distortions are lower than expected. International quota transfer increases world welfare proportionally to quota rent gap. Welfare distribution is also conditioned by commodity terms of trade and, particularly, by the outcome of the intermediate good price.
On the solvability of bipolar max-product fuzzy relation equations with the standard negation
Creators: name: Cornejo, M. Eugenia
name: Lobo, David
name: Medina, Jesús
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics

description: Bipolar fuzzy relation equations arise when unknown variables together with their logical negations appear simultaneously in fuzzy relation equations. This paper gives a characterization of the solvability of bipolar max product fuzzy (relation) equations with the standard negation. In addition, some properties associated with the existence of the greatest/least solution or maximal/minimal solutions are shown, when these (relation) equations are solvable. Different examples are included in order to clarify the developed theory.