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arXiv 2024年

作者： Akama, Shingo Orlando, Giorgio Delgado, Paola C.M. Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow30-348 Poland

It has been shown that a three-point correlation function of tensor perturbations from a bounce model in general relativity with a minimally-coupled scalar field is highly suppressed, and the resultant three-point function of cosmic microwave background (CMB) B-mode polarizations is too small to be detected by CMB experiments. On the other hand, bounce models in a more general class with a non-minimal derivative coupling between a scalar field and gravity can predict the three-point correlation function of the tensor perturbations without any suppression, the amplitude of which is allowed to be much larger than that in general relativity. In this paper, we evaluate the three-point function of the B-mode polarizations from the general bounce cosmology with the non-minimal coupling and show that a signal-to-noise ratio of the B-mode auto-bispectrum in the general class can reach unity for max ≥ 9 and increase up to 5.39 for max = 100 in the full-sky case. We also discuss the possibility to test the general class of bounce models by upcoming CMB experiments. Copyright © 2024, The Authors. All rights reserved.

关键词： Tensors

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Parity violation in primordial tensor non-Gaussianities from matter bounce cosmology

arXiv

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arXiv 2024年

作者： Akama, Shingo Zhu, Mian Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow30-348 Poland

It has been shown that primordial tensor non-Gaussianities from a cubic Weyl action with a non-dynamical coupling are suppressed by the so-called slow-roll parameter in a conventional framework of slow-roll inflation. In this paper, we consider matter bounce cosmology in which the background spacetime is no longer quasi-de Sitter, and hence one might expect that the matter bounce models could predict non-suppressed non-Gaussianities. Nevertheless, we first show that the corresponding non-Gaussian amplitudes from the cubic Weyl term with a non-dynamical coupling are much smaller than those from the conventional slow-roll inflation, in spite of the fact that there is no slow-roll suppression. We then introduce a dynamical coupling that can boost the magnitude of graviton cubic interactions and clarify that there is a parameter region where the tensor non-Gaussianities can be enhanced and can potentially be tested by cosmic microwave background experiments. Copyright © 2024, The Authors. All rights reserved.

关键词： Tensors

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Prefix-Free Parsing for Building Large Tunnelled Wheeler Graphs 22

Prefix-Free Parsing for Building Large Tunnelled Wheeler Gra...

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22nd International Workshop on Algorithms in Bioinformatics, WABI 2022

作者： Goga, Adrián Baláž, Andrej Department of Computer Science Faculty of Mathematics Physics and Informatics Comenius University Bratislava Slovakia Department of Applied Informatics Faculty of Mathematics Physics and Informatics Comenius University Bratislava Slovakia

ISBN: (纸本)9783959772433

We propose a new technique for creating a space-efficient index for large repetitive text collections, such as pangenomic databases containing sequences of many individuals from the same species. We combine two recent techniques from this area: Wheeler graphs (Gagie et al., 2017) and prefix-free parsing (PFP, Boucher et al., 2019). Wheeler graphs are a general framework encompassing several indexes based on the Burrows-Wheeler transform (BWT), such as the FM-index. Wheeler graphs admit a succinct representation which can be further compacted by employing the idea of tunnelling, which exploits redundancies in the form of parallel, equally-labelled paths called blocks that can be merged into a single path. The problem of finding the optimal set of blocks for tunnelling, i.e. the one that minimizes the size of the resulting Wheeler graph, is known to be NP-complete and remains the most computationally challenging part of the tunnelling process. To find an adequate set of blocks in less time, we propose a new method based on the prefix-free parsing (PFP). The idea of PFP is to divide the input text into phrases of roughly equal sizes that overlap by a fixed number of characters. The phrases are then sorted lexicographically. The original text is represented by a sequence of phrase ranks (the parse) and a list of all used phrases (the dictionary). In repetitive texts, the PFP representation of the text is generally much shorter than the original since individual phrases are used many times in the parse, thus reducing the size of the dictionary. To speed up the block selection for tunnelling, we apply the PFP to obtain the parse and the dictionary of the original text, tunnel the Wheeler graph of the parse using existing heuristics and subsequently use this tunnelled parse to construct a compact Wheeler graph of the original text. Compared with constructing a Wheeler graph from the original text without PFP, our method is much faster and uses less memory on collections of

关键词： Graphic methods

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Enhancing the Swanepoel method: precise envelope detection of thin-film transmission spectra

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Optics Express 2025年第6期33卷 13376-13400页

作者： Ballester, Manuel Marquez, Almudena P. Lopez-Tapia, Santiago Fernandez, Susana Bass, John Minkov, Dorian Wuersch, Christoph Willomitzer, Florian Marquez, Emilio Katsaggelos, Aggelos K. Computer Science Department Northwestern University EvanstonIL60208 United States Department of Mathematics Faculty of Science University of Cadiz Puerto Real11510 Spain Department of Electrical and Computer Engineering Northwestern University EvanstonIL60208 United States CIEMAT Avenida Complutense 40 Madrid28040 Spain Wyant College of Optical Sciences University of Arizona TucsonAZ85721 United States Sofia1000 Bulgaria Institute for Computational Engineering ICE OST Eastern Switzerland University of Applied Sciences Switzerland Department of Condensed-matter Physics Faculty of Science University of Cadiz Puerto Real11510 Spain

The Swanepoel method is a widely used optical technique for characterizing thin films through normal-incidence transmission measurements. A critical step in this approach involves extracting the upper and lower envelopes of the measured oscillatory spectrum. By analyzing the transmission spectrum and its corresponding envelopes, the Swanepoel procedure enables precise determination of the film refractive index and extinction coefficient. However, even minor inaccuracies in envelope construction can propagate significant errors into the final characterization results. To address this challenge, we present what we believe to be a novel physics-informed optimization algorithm for envelope detection. Our mathematical model reformulates the envelope detection problem as a global optimization task that enforces the physical properties of the Swanepoel envelopes. Extensive validation on fifty randomly generated transmission spectra demonstrates unprecedented accuracy: the method achieves root-mean-square errors (RMSE) below 0.10% for the upper envelope and 0.06% for the lower envelope (more than doubling the accuracy of current state-of-the-art approaches). Furthermore, the proposed model has been assessed with two experimental transmission spectra, demonstrating its robustness and accuracy with real noisy data. We have developed an open-source Python software package (see text below). This software includes not only our innovative envelope construction algorithm but also additional envelope drawing algorithms for comparison and an efficient implementation of the Swanepoel method, enabling complete optical characterization of thin films. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

关键词： Mean square error

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Ask the experts: Sourcing a high-quality nutrition counseling dataset through Human-AI collaboration

Ask the experts: Sourcing a high-quality nutrition counselin...

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2024 Conference on Empirical Methods in Natural Language Processing, EMNLP 2024

作者： Balloccu, Simone Reiter, Ehud Li, Karen Jia-Hui Sargsyan, Rafael Kumar, Vivek Recupero, Diego Reforgiato Riboni, Daniele Dusek, Ondrej Charles University Faculty of Mathematics and Physics Institute of Formal and Applied Linguistics Prague Czech Republic Department of Computing Science University of Aberdeen United Kingdom FI CODE University of Bundeswehr Munich Germany Department of Mathematics and Computer Science University of Cagliari Italy

ISBN: (纸本)9798891761681

Large Language Models (LLMs) are being employed by end-users for various tasks, including sensitive ones such as health counseling, disregarding potential safety concerns. It is thus necessary to understand how adequately LLMs perform in such domains. We conduct a case study on ChatGPT in nutrition counseling, a popular use-case where the model supports a user with their dietary struggles. We crowdsource real-world diet-related struggles, then work with nutrition experts to generate supportive text using ChatGPT. Finally, experts evaluate the safety and text quality of ChatGPT's output. The result is the HAI-Coaching dataset, containing ∼2.4K crowdsourced dietary struggles and ∼97K corresponding ChatGPT-generated and expert-annotated supportive texts. We analyse ChatGPT's performance, discovering potentially harmful behaviours, especially for sensitive topics like mental health. Finally, we use HAI-Coaching to test open LLMs on various downstream tasks, showing that even the latest models struggle to achieve good performance. HAI-Coaching is available at https://***/uccollab/hai-coaching/. © 2024 Association for Computational Linguistics.

关键词： Computational linguistics

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Influence of structural defects on charge density waves in 1T-TaS_(2)

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Nano Research 2023年第8期16卷 11528-11539页

作者： Iaroslav Lutsyk Karol Szalowski Pawel Krukowski Pawel Dabrowski Maciej Rogala Witold Kozlowski Maxime Le Ster Michal Piskorski Dorota A.Kowalczyk Wojciech Rys Rafal Dunal Aleksandra Nadolska Klaudia Toczek Przemyslaw Przybysz Ewa Lacinska Johannes Binder Andrzej Wysmolek Natalia Olszowska Jacek J.Kolodziej Martin Gmitra Takuma Hattori Yuji Kuwahara Guang Bian Tai-Chang Chiang Pawel J.Kowalczyk Faculty of Physics and Applied Informatics University of LodzPomorska 149/15390-236 LodzPoland Faculty of Physics University of WarsawPasteura 502-093 WarsawPoland Faculty of Physics Astronomyand Applied Computer ScienceJagiellonian UniversityLojasiewicza 1130-348 KrakowPoland National Synchrotron Radiation Centre SOLARIS Jagiellonian UniversityCzerwone Maki 9830-392 KrakówPoland Institute of Physics Faculty of SciencePavol JozefŠafárik University in KošicePark Angelinum 904001 KošiceSlovakia Institute of Experimental Physics Slovak Academy of SciencesWatsonova 4704001 KošiceSlovakia Department of Precision Engineering Graduate School of EngineeringOsaka University2-1 Yamada-okaSuita 565-0871Japan Department of Physics and Astronomy University of MissouriColumbiaMissouri 65211USA Department of Physics and Frederick Seitz Materials Research Laboratory University of Illinois at Urbana-ChampaignUrbanaIllinois 61801-3080USA

The influence of intrinsic defects of 1T-TaS_(2)on charge density waves(CDWs)is studied using scanning tunneling microscopy and spectroscopy(STM,STS),angle-resolved photoelectron spectroscopy(ARPES),and density functional theory(DFT).We identify several types of structural defects and find that most have a local character limited to a single CDW site,with a single exception which effectively behaves as a dopant,leading to band-bending and affecting multiple neighboring *** only one type of defect can be observed by STM topographic imaging,all defects are easily resolved in STS *** results indicate modulation of the Mott band gap commensurate with the CDW and breaking of the three-fold symmetry of electronic *** calculations(with included Coulomb interactions)are used to investigate the electronic structure,focusing on both sulfur vacancy and oxygen-sulfur *** sulfur vacancy system,characterized with a metallic behavior,is identified as the origin of one of the experimentally observed ***,the effect of oxidation of 1T-TaS_(2)depends on the substitution site,leading to the heterogeneity of electronic properties.

关键词： structural charge sulfur

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Are You Aroused Enough to See the Difference? The Role of Physiological Arousal in Perceiving Realism of Virtual Scene

Are You Aroused Enough to See the Difference? The Role of Ph...

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2023 IEEE International Symposium on Mixed and Augmented Reality Adjunct, ISMAR-Adjunct 2023

作者： Lipp, Natalia Strojny, Pawel Strojny, Agnieszka Śpiewak, Slawomir Argasiński, Jan Korzeniowski, Przemyslaw Sano Centre for Computational Medicine Kraków Poland Jagiellonian University Faculty of Management and Social Communication Kraków Poland Jagiellonian University Faculty of Physics Astronomy and Applied Computer Science Kraków Poland

ISBN: (纸本)9798350328912

Simulation realism is a crucial factor for task performance in virtual reality. The issue is that it does not simply result from a simulation's graphical quality and is often connected to users' expectations and the capacity of the cognitive system. It is assumed that perceived realism may be affected by physiological arousal which is the basis of emotional reactions and of attention prioritizing. The main aim of the presented study is to verify whether perceptual characteristics of a virtual scene - complexity and vividness of virtual objects - affect perceived realism. The secondary aim is to test whether realism assessment changes because of arousal. An experimental study was conducted with 100 participants in total. Four experimental groups differ in terms of the complexity of a virtual scene (i.e., number of objects in the field of view) and vividness of virtual objects (i.e., figure-ground contrast). Participants were asked to perform a task, that was taking on the role of a marshaller and positioning the plane on the airport apron in the virtual reality simulation. During the task, electrodermal activity was measured. After the virtual session, participants assessed perceived realism. Results indicate that the complexity and vividness of virtual scene do not affect perceived realism directly. Physiological arousal (i.e., skin conductance level) is a moderator of the relationship between the vividness of the virtual scene and perceived realism. A high level of arousal increases realism assessment in vivid simulations. © 2023 IEEE.

关键词： Virtual reality

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LSTM Deep Learning Method for Radiation Short and Long-Term Prediction 7th

LSTM Deep Learning Method for Radiation Short and Long-Term ...

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7th International Conference on Smart City Applications, SCA 2022

作者： Khala, Mohamed Abouzid, Houda Teidj, Sara Eloutassi, Omar Messaoudi, Choukri Optoelectronics and Applied Energy Techniques Faculty of Science and Technology Moulay Ismail University of Meknes Meknes Morocco Computer Science and New Technology Trends Abdelmalek Essaadi University Tetouan Morocco Department of Physics Faculty of Science and Technology Moulay Ismail University of Meknes Meknes Morocco

ISBN: (纸本)9783031268519

The renewable energy market, like conventional energy, is often unstable. Solar energy in particular presents disturbances linked to the spatiotemporal fluctuations that solar radiation undergoes. To remedy this problem, it is essential to predict its fluctuations that have exhausting consequences for integration into the electricity network and reduce the dependence on fossil fuels essential for socio-economic development. The main objective of this study is to propose a prognostication model based on artificial intelligence to predict with great accuracy the fluctuations of global solar radiation (GSR). Indeed, we adopted a deep dynamic recurrent memory artificial neural network (ANN) model which can manipulate the dynamics of atmospheric factors and is capable to save the history of these characteristics. For this purpose, we developed two long-short term memory (LSTM) models for short and long term forecasting of global solar radiation time series. The first model is a monovariate LSTM, the second one is a multivariate LSTM, after selecting the input variables (predictors) by correlation study, the models are trained by dividing the data set into two subsections, the first subsection is used for model training and the second subsection is reserved for testing. The indices and results established in this work demonstrate the robustness attributed to our method which can provide power grid managers at Er-Rachidia, MOROCCO (Latitude: 31°55′53″N;Longitude: 4°25 ′35″ W;Altitude: 1039 m) credible predictions to ensure better supervision of the energy system and to adapt solar energy to the electricity production system, especially multivariate LSTM model which proved more accuracy compared to monovariate LSTM. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Forecasting

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Studies of Critical Phenomena in Causal Dynamical Triangulations on a Torus

arXiv

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arXiv 2023年

作者： Németh, Dániel Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Poland

This document contains my publications and results based on research done as a member of the Causal Dynamical Triangulations (CDT) group at the Jagiellonian University during my PhD studies. The field of my research was the four-dimensional CDT, which is a lattice regularization of the theory of quantum gravity, based on the formalism of Regge Calculus and Feynman path integrals. Due to mathematical complexity, analytical solutions to the model exists only in two dimensions. The four-dimensional theory is analyzed by numerical simulations. Earlier discoveries include dynamically emergent quantum de Sitter universes with emergent four-dimensional properties, scale-dependent spectral dimensions and a complex phase structure in which first- and higher-order phase transitions were shown to exist. The document describes the nature of previously not yet analyzed phase transitions, new ways to analyze triangulations and the impact of classical and dynamical (quantum) scalar fields in four-dimensional CDT with toroidal spatial topology. The main results of the dissertation are the six publications attached to the last chapter. This document is intended as an introduction to CDT and serves as a guide to the papers comprising the doctoral thesis. © 2023, CC BY.

关键词： Triangulation

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"To renormalize or not to renormalize ?" in the proton-deuteron scattering calculations

arXiv

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arXiv 2024年

作者： Witala, H. Golak, J. Skibiński, R. Smoluchowski, M. Institute of Physics Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University KrakówPL-30059 Poland

We discuss two approaches which, by applying the screening method, permit one to include the long range proton-proton (pp) Coulomb force in proton-deuteron (pd) momentum-space scattering calculations. In the first one, based on Alt-Grassberger-Sandhas (AGS) equation, presented in Phys. Rev. C71, 054005 (2005) and 73, 057001 (2006), one needs to renormalize elastic scattering amplitude before calculating observables. In the second treatment, proposed by us in Eur. Phys. Journal A 41, 369 (2009), 41, 385 (2009), and arXiv:2310.03433 [***], this renormalization is avoided. For the proton induced deuteron breakup reaction both approaches require renormalization of the corresponding transition amplitudes. We derive the basic equations underlying both methods under the assumption that all contributing partial wave states are included and explain why in our approach renormalization of the elastic scattering amplitude is superfluous. We show that in order to take into account in the screening limit all partial waves it is required that four additional terms, based on the 3-dimensional and partial-wave projected pp Coulomb t-matrices, identical for both approaches, must appear in transition amplitudes. We investigate importance of these terms for elastic pd scattering below the breakup threshold. © 2024, CC BY.

关键词： Elastic scattering

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