cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Out-of-time-order fluctuation-dissipation theorem
Creators: name: Tsuji, Naoto
name: Shitara, Tomohiro
name: Ueda, Masahito
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We prove a generalized fluctuation-dissipation theorem for a certain class of out-of-time-ordered correlators (OTOCs) with a modified statistical average, which we call bipartite OTOCs, for general quantum systems in thermal equilibrium. The difference between the bipartite and physical OTOCs defined by the usual statistical average is quantified by a measure of quantum fluctuations known as the Wigner-Yanase skew information. Within this difference, the theorem describes a universal relation between chaotic behavior in quantum systems and a nonlinear-response function that involves a time-reversed process. We show that the theorem can be generalized to higher-order $n$-partite OTOCs as well as in the form of generalized covariance.
Robust and scalable domain decomposition solvers for unfitted finite element methods
Creators: name: Badia, Santiago
name: Verdugo, Francesc
Publisher: name: arXiv
Year: 2017
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: Unfitted finite element methods, e.g., extended finite element techniques or the so-called finite cell method, have a great potential for large scale simulations, since they avoid the generation of body-fitted meshes and the use of graph partitioning techniques, two main bottlenecks for problems with non-trivial geometries. However, the linear systems that arise from these discretizations can be much more ill-conditioned, due to the so-called small cut cell problem. The state-of-the-art approach is to rely on sparse direct methods, which have quadratic complexity and are thus not well suited for large scale simulations. In order to solve this situation, in this work we investigate the use of domain decomposition preconditioners (balancing domain decomposition by constraints) for unfitted methods. We observe that a straightforward application of these preconditioners to the unfitted case has a very poor behavior. As a result, we propose a {customization} of the classical BDDC methods based on the stiffness weighting operator and an improved definition of the coarse degrees of freedom in the definition of the preconditioner. These changes lead to a robust and algorithmically scalable solver able to deal with unfitted grids. A complete set of complex 3D numerical experiments show the good performance of the proposed preconditioners.
Hyper-volatile Entrapment in Interstellar Ice Analogues
Creators: name: Fitzsimmons, Anna
name: Piacentino, Elettra
name: Oberg, Karin I.
name: Rajappan, Mahesh
Publisher: name: Zenodo
Year: 2024
Subjects: hyper-volatiles
planets
interstellar ice
infrared spectroscopy
quadrupole mass spectrometry
Astro 98

description: Planets and planetesimals acquire their volatile reservoir through ice and gas accretion in proto-planetary disks. The distribution of volatiles between solid and gas phases within these disks thus determines the quantity of volatiles accreted onto a solid core or gaseous atmosphere of planets forming throughout different disk regions. The entrapment of hyper-volatiles in less volatile ices allows the hyper-volatile to remain solid beyond its sublimation temperature, producing more complex chemical profiles than what would be expected for simple snowline models. This study uses laboratory experiments to explore the ability of several abundant interstellar ices (H2O, CO2, NH3, CH3OH, and C2H6) to trap key hyper-volatile components, (CO, CH4, N2, and Ar). The entrapment efficiencies of these ices are measured for each hyper-volatile through temperature programmed desorption (TPD) experiments. During the TPD, the ice is heated at a rate of 1 K/min, and the desorption of both the hyper-volatile and ice species is detected using a quadrupole mass spectrometer (QMS) and further monitored by infrared (IR) spectroscopy.

Preliminary results find entrapment efficiencies around 60% for H2O and CO2, aligning with fiducial efficiencies previously reported. Entrapment in NH3 ices showed comparable efficiencies to H2O and suggesting an entrapment mechanism that operates independently of the chemical properties of both the hyper-volatile and ice species. However, the entrapment efficiencies for CH3OH and C2H6 diverged drastically from this trend; less than 10% entrapment was observed for mixtures of N2 and Ar in CH3 OH; the observed entrapment efficiencies for mixtures of CO, CH4 , N2 , and Ar in C2 H6 were 30%,10%, 70%, and 40% respectively. To further investigate the peculiar entrapment patterns observed for CH3OH and C2H6 matrices, entrapment efficiencies were re-calculated using a new method – defined for this study as β-entrapment – that includes hyper-volatile desorption occurring at temperatures between the sublimation temperatures of the hyper-volatile and ice matrix. Using the β-entrapment definition (as opposed to the previously used α-entrapment definition that only includes co-desorbing hyper-volatiles) to calculate entrapment efficiency did produce results more comparable for all hyper-volatiles across all matrix species. Nevertheless, further investigation into the entrapment mechanism, particularly for organic matrix species, is likely warranted to completely understand entrapment as a whole. A complete understanding of entrapment and a comprehensive catalogue of entrapment efficiencies would provide the framework to explain and predict the volatile ratios in protoplanetary disks and their subsequent planets.
description: Astro 98
Examples of non-trivial contact mapping classes for overtwisted contact manifolds in all dimensions
Creators: name: Gironella, Fabio
Publisher: name: arXiv
Year: 2017
Subjects: subject: Symplectic Geometry (math.SG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 53D10, 57R17

description: We construct (infinitely many) examples in all dimensions of contactomorphisms of closed overtwisted contact manifolds that are smoothly isotopic but not contact-isotopic to the identity.
description: v3: Considerable improvement in both content and form, thanks to referee's suggestions; version corresponding to the published one; 18 pages. v2: Minor changes with respect to the first version, 20 pages
Star Formation Rates of High Redshift Galaxies: JADES High Hα Emitters and their Evolution with Redshift and Luminosity
Creators: name: Griffin, Ellie
Publisher: name: Zenodo
Year: 2024
Subjects: star formation
redshift galaxies
galaxy evolution
Astro 98

description: To understand the formation and evolution of galaxies in our Universe, the star formation rate (SFR) is an important parameter. Here we use deep Near-Infrared Camera (NIRCam) imaging with six medium band filters from JADES (JWST Advanced Deep Extragalactic Survey) to form catalogues of high Hα-emitting galaxies in the GOODS-S field across a redshift range of z ∼ 1.3 to z ∼ 4.5. These catalogues represent the galaxies with high SFRs, as Hα serves as a marker of star formation. The filters used–F335M, F300M, F250M, F210M, F182M, and F162M–comprise the medium bands currently with the deepest imaging from the James Webb Space Telescope (JWST) with exposure times of over 30 hours. We utilized the JADES photometry to determine the number density, luminosity, and Hα equivalent width (EW) values of the high Hα emitters across the filters. We see evidence of increased density of high Hα emitters in the F250M and F300M filters, corresponding to redshifts z ∼ 2.6 to z ∼ 3.9. These filters also show higher luminosities of the high-Hα-emitting galaxies when compared to adjacent filters. Additionally, a peak in the rest Hα EW is observed in the F182M filter, at an average redshift z ∼ 1.8. The photometry from JADES enables this analysis of high-Hα-emitting galaxies at high redshifts and low luminosities to contribute to the understanding of how the number density and luminosity of vigorously-star-forming galaxies changes with redshift.
description: Astro 98
A Search for Pulsations in M Dwarfs in 20-second Cadence TESS Data
Creators: name: Painter, Caleb
Publisher: name: Zenodo
Year: 2024
Subjects: red-giant stars
photometry
spectroscopy
dwarf stars
Astro 98

description: Asteroseismology is a powerful tool in probing the internal structure and ages of solar-type and red- giant stars, through the study of oscillations detectable in photometric and spectroscopic observations. As of yet though, it has not been successfully applied to low mass stars. We present the results of a search for solar-like oscillations in M dwarf stars observed by TESS in the 20-second cadence mode. Our analysis covers all M dwarfs between 0.1M⊙ and 0.3M⊙ within 15pc listed in the catalog of Winters et al. (2021), comprising 512 in total, as well as an extended sample of 705 stars based on the Fifth Catalogue of Nearby Stars and the All-sky Catalogue of Bright M Dwarfs (Golovin et al. 2023, L ́epine & Gaidos 2011). Of these 1217 stars, 868 of them had at least one corresponding 20-second TESS observation. We probe frequencies up to the Nyquist frequency of 25000 μHz, making this study the largest sample size and highest time-resolution search for pulsations in M dwarfs to date. We quantify the sensitivity of our search through signal injection and recovery tests of synthetic oscillations. Our detection thresholds are between 10 − 40 parts per million (ppm) for 54% of stars in our combined sample and between 1-10 ppm for 38% of them. We reach detection thresholds bewteen 0.2-1 ppm for nine of the stars in our sample. We co-add the power spectra of M dwarfs with similar masses to search for signals that might be too noisy to detect in individual stars and discuss the efficacy of this method. The analysis reveals no clear solar-like oscillations for any of the M dwarfs in our sample, suggesting that the driving mechanisms behind oscillations in M dwarfs do not produce large enough amplitudes to be observable with the current photometric precision of TESS.
description: Astro 98
title: КУЛЬТУРНАЯ ИНТЕРВЕНЦИЯ КАК МЕТОД РЕГЕНЕРАЦИИ ЗОНЫ ИСТОРИЧЕСКОЙ ЗАСТРОЙКИ
Creators: name: Афанасьев, Кирилл
Publisher: name: Новгородский государственный университет имени Ярослава Мудрого (НовГУ)
Year: 2022

description: В рамках представленной работы рассматриваются подходы и методы, связанные с формированием нового отношения заинтересованных лиц к проектам регенерации зоны исторической застройки современного города. Одним из действенных механизмов запуска социальных изменений являются культурные интервенции – варианты временной активности, сочетающей элементы перформанса и подходы, характерные для тактического урбанизма. Итогом применения данного инструмента является переформатирование ассоциативного поля и привычного восприятия исторического объекта в пользу его перспективного использования. Практическое применение данного инструмента в Санкт-Петербурге продемонстрировало значительное изменение отношения жителей к новым функциям исторических зданий, что позволяет адаптировать концепции и планы в отношении регенерации зоны исторической застройки. В качестве возможного применения культурных интервенций можно упомянуть тестирование проектов создания общественных пространств, концепций культурных мероприятий и форматов самоорганизации жителей для решения общих проблем.
Constraining the Dynamics and Distances to Intermediate Velocity Clouds Using a 3D Galactic Dust Map
Creators: name: Yoshida, Stephanie
Publisher: name: Zenodo
Year: 2024
Subjects: dust map
galactic rotation
intermediate velocity clouds
Astro 98

description: Intermediate velocity clouds (IVCs) are composed of low-density gas in the lower portion of the Galactic halo and move at velocities of 20 to 90 km s−1, anomalous compared to Galactic rotation and typical velocity dispersion. IVCs are thought to be clouds previously ejected from the disk by feedback events, such as supernovae, that are cooling and falling back onto the Galactic disk as part of the Galactic fountain. The release of a high resolution, three-dimensional dust map of the Milky Way from Edenhofer et al. (2023) has the potential to constrain the distances to IVCs with lower distance uncertainties than traditional approaches based on UV absorption towards background stars, which are only able to provide an upper limit on the cloud’s distance based on the star’s distance. In this study, we target these potential IVCs detected in the 3D dust map by exploring clouds significantly above and below the Galactic disk (| z |> 500 pc) with significant dust densities. We employ a peak finding algorithm on the line-of-sight dust density distribution to constrain the distances to clouds that lie within the boundary of the Edenhofer 3D dust map (69 pc < d < 1.25 kpc) and beyond our Galactic height cut. Using HI 21 cm emission from the HI4PI all-sky survey, we then measure the line-of-sight radial velocity of each distance peak to determine the velocity of each IVC, as well as any velocity gradient across the cloud. By cross-referencing with a study conducted by R ̈ohser, T. et al. (2016), we preliminary identified five IVCs. Morphological matching between the Edenhofer et al. (2023) map and HI4PI survey indicated that all five clouds were good candidates for IVCs. These kinematic constraints provide important inputs for solving the trajectories of the potential IVCs, which will be the subject of future work. These combined spatial and dynamical measurements of a uniform sample of IVCs should help constrain models of inflows/outflows of the Galactic fountain, which plays a key role in the overall galactic baryon cycle of the Galaxy.
description: Astro 98
Relations between positivity, localization and degrees of freedom: the Weinberg-Witten theorem and the van Dam-Veltman-Zakharov discontinuity
Creators: name: Mund, Jens
name: Rehren, Karl-Henning
name: Schroer, Bert
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The problem of accounting for the quantum degrees of freedom in passing from massive higher-spin potentials to massless ones and its inverse, the "fattening" of massless tensor potentials of helicity $\pm h$ to their massive $s = |h|$ counterparts, are solved - in a perfectly ghost-free approach - using "string-localized fields". This approach allows to overcome the Weinberg-Witten impediment against the existence of massless $|h| \geq 2$ energy-momentum tensors, and to qualitatively and quantitatively resolve the van Dam-Veltman-Zakharov discontinuity concerning, e.g., very light gravitons, in the limit $m \to 0$.
description: v3: Final version as to appear in Phys.Lett.B. This is an abridged version of arXiv:1703.04407
Discrete-time construction of nonequilibrium path integrals on the Kostantinov-Perel' time contour
Creators: name: Secchi, Andrea
name: Polini, Marco
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Rigorous nonequilibrium actions for the many-body problem are usually derived by means of path integrals combined with a discrete temporal mesh on the Schwinger-Keldysh time contour. The latter suffers from a fundamental limitation: the initial state on this contour cannot be arbitrary, but necessarily needs to be described by a non-interacting density matrix, while interactions are switched on adiabatically. The Kostantinov-Perel' contour overcomes these and other limitations, allowing generic initial-state preparations. In this Article, we apply the technique of the discrete temporal mesh to rigorously build the nonequilibrium path integral on the Kostantinov-Perel' time contour.
description: This is the version of the article before peer review or editing, as submitted by an author to Journal of Physics A: Mathematical and Theoretical. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://dx.doi.org/10.1088/1751-8121/ab2080
Low-energy phonons in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ and their possible interaction with electrons measured by inelastic neutron scattering
Creators: name: Merritt, A. M.
name: Castellan, J. -P.
name: Keller, T.
name: Park, S. R.
name: Fernandez-Baca, J. A.
name: Gu, G. D.
name: Reznik, D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Electron-phonon interaction in copper oxide superconductors is still enigmatic. Strong coupling for certain optic phonons is now well established experimentally, but theoretical understanding is challenging. Scattering of electrons near the Fermi surface by the longitudinal acoustic (LA) phonons is expected from basic theory because these phonons modulate electron density. We used inelastic neutron scattering on a large single crystal sample of optimally-doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ to show that low-energy LA phonons could couple to electronic density fluctuations only at small phonon wavevectors, which naturally limits any interaction to forward scattering. Such scattering should not be pairbreaking in the case of the d-wave gap. We also found that previously the reported low energy phonon spectral weight half-way to the zone boundary is consistent with conventional lattice dynamics and does not reflect an incipient charge density wave.
description: Updated Oct. 2019 to include new measurements and additional discussion. 7 pages, 4 figures, Supplementary included: 6 pages, 5 figures
Database on hydrogeochemical properties of geothermal reservoirs in the Netherlands
Creators: name: Kottsova, Anna
name: Brehme, Maren
Publisher: name: Zenodo
Year: 2022

description: This is a database related to the EASYGO Report - Deliverable 1.1 - Database on hydrogeochemical properties of geothermal reservoirs in the Netherlands. The spreadsheet provides the following data: General properties (General information about geothermal wells, such as stratigraphy, depth, reservoir temperature, etc.) Brine composition (Information about the chemical composition of the produced brines, incl. fluid properties (pH, salinity, etc.)) Gas composition (Information about the chemical composition of the flashed gas)
Skewed target range strategy for multiperiod portfolio optimization using a two-stage least squares Monte Carlo method
Creators: name: Zhang, Rongju
name: Langrené, Nicolas
name: Tian, Yu
name: Zhu, Zili
name: Klebaner, Fima
name: Hamza, Kais
Publisher: name: arXiv
Year: 2017
Subjects: subject: Portfolio Management (q-fin.PM)
subject: Computational Finance (q-fin.CP)
subject: General Finance (q-fin.GN)
subject: Risk Management (q-fin.RM)
subject: FOS: Economics and business
subject: J.4; G.3; I.2.8; G.1.6
subject: 91G10, 91G80, 91G60

description: In this paper, we propose a novel investment strategy for portfolio optimization problems. The proposed strategy maximizes the expected portfolio value bounded within a targeted range, composed of a conservative lower target representing a need for capital protection and a desired upper target representing an investment goal. This strategy favorably shapes the entire probability distribution of returns, as it simultaneously seeks a desired expected return, cuts off downside risk and implicitly caps volatility and higher moments. To illustrate the effectiveness of this investment strategy, we study a multiperiod portfolio optimization problem with transaction costs and develop a two-stage regression approach that improves the classical least squares Monte Carlo (LSMC) algorithm when dealing with difficult payoffs, such as highly concave, abruptly changing or discontinuous functions. Our numerical results show substantial improvements over the classical LSMC algorithm for both the constant relative risk-aversion (CRRA) utility approach and the proposed skewed target range strategy (STRS). Our numerical results illustrate the ability of the STRS to contain the portfolio value within the targeted range. When compared with the CRRA utility approach, the STRS achieves a similar mean-variance efficient frontier while delivering a better downside risk-return trade-off.
description: 25 pages, 10 figures
Foliation boudinage structures in the Mount Isa Cu system
Creators: name: Williams, B. J.
name: Blenkinsop, T. G.
name: Lilly, R.
name: Thompson, M. P.
name: Ila’ava, P.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biophysics
subject: Space Science
subject: Medicine
subject: Neuroscience
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Evolutionary Biology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Astronomical and Space Sciences not elsewhere classified
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Infectious Diseases
subject: FOS: Health sciences

description: Small-scale foliation boudinage structures occur in rocks that were sampled in drill core from the Mount Isa Cu deposit, northwest Queensland. The necks of foliation boudinage structures plunge gently to the north and south as a result of layer normal shortening and layer parallel extension of the steeply west-dipping Urquhart Shale. Detailed petrographic analysis of the foliation boudinage structures has identified an initial rim of quartz and dolomite, followed by infill and replacement by pyrrhotite and minor chalcopyrite. Foliation boudinage structures formed after dolomitisation and silicification of the shale. They occur most commonly in the unaltered Urquhart Shale where the anisotropy and homogeneity provided by the shale layering is still intact. Infilling of the structures occurred during protracted silica-dolomite alteration, pyrrhotite and chalcopyrite mineralisation. The paragenesis of the foliation boudinage structures is consistent with the established paragenesis of the main Cu mineralisation. Foliation boudinage structures formed over the period from shortening during D4a through to the main Cu mineralisation during D4b west-northwest–east-southeast sinistral-reverse shortening. The timing of foliation boudinage is consistent with a current kinematic model for the Mount Isa system.KEY POINTSFirst record of foliation boudinage structures at Mount Isa.Foliation boudinage structures with sulfide-dominated infills.Foliation boudinage structures formed as a result of progressive deformation from a D4a dextral-reverse through to D4b sinistral-reverse slip.Foliation boudinage structures are associated with the timing and kinematics of Cu mineralisation at Mount Isa. First record of foliation boudinage structures at Mount Isa. Foliation boudinage structures with sulfide-dominated infills. Foliation boudinage structures formed as a result of progressive deformation from a D4a dextral-reverse through to D4b sinistral-reverse slip. Foliation boudinage structures are associated with the timing and kinematics of Cu mineralisation at Mount Isa.
A uniform bound on the Brauer groups of certain log K3 surfaces
Creators: name: Bright, Martin
name: Lyczak, Julian
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 14F22

description: Let U be the complement of a smooth anticanonical divisor in a del Pezzo surface of degree at most 7 over a number field k. We show that there is an effective uniform bound for the size of the Brauer group of U in terms of the degree of k.
description: Minor improvements to presentation
Analysis on "The Spirit of the Prosperous Tang Dynasty" and "Picturesense" of Frontier Fortress Poetry in the Prosperous Tang Dynasty
Creators: name: Chen, Luo
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Tang Poetry
Frontier Fortress Poetry in the Prosperous Tang Dynasty
Tang Dynasty
Picture Sense
Spirit of the Prosperous Tang Dynasty

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 1-13
Professional Learning Community with Interventions for STEM School Improvement: A Case Study of Surin Phitthayakom School, Surin Province, Thailand
Creators: name: Amnuay Wattanakornsiri
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Interventions
Professional Learning Community
Whole School Approach

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 14-22
A Comparative Study of Hedging in English Research Article Discussion Written by Thai, Chinese, and Saudi Arabian Writers
Creators: name: Chuthaporn Somsakoon
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Hedging
Academic Writing
Research Discussion
Research Articles
NNS Writers
Cross-cultural Discourse

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 23-34
Generation of Supernova Spectral Evolution Templates
Creators: name: Chen, Kobe
name: Villar, Ashley
Publisher: name: Zenodo
Year: 2024
Subjects: supernovae classification
transient classification
photometry
temporal evolution of supernovae
Astro 98

description: The advent of improved large sky surveys necessitates the development of photometric methods of transient classification, due to the resource limitations of spectroscopic analysis. This paper introduces a photometric approach to supernova identification, using a Python package named ’extrabol’ (2). Extrabol transforms photometric data into bolometric light curves using Gaussian process regression and blackbody laws. This method does not rely on assumptions about the system’s physical properties and aggregates data across energy bands to calculate bolometric flux. The bolometric flux allows us to study the temporal evolution of supernovae and infer their physical characteristics.

The focus of this paper is on the development of templates to guide ’extrabol’ in predicting supernova evolution. By analyzing over 500 spectroscopically verified supernovae, focusing on types Ia and II, we established average light curve templates. These templates inform ’extrabol’ about expected supernova evolution, allowing for more accurate predictions, particularly in data-sparse scenarios. Our templates were derived from the averages of bolometric luminosity and temperature, weighted by uncertainty, and formulated using blackbody laws.

Testing the templates involved simulating observational gaps and assessing ’extrabol’s performance in filling these gaps. Results showed a significant improvement in prediction accuracy, as evidenced by a reduction in mean squared error. These templates allow us to model the spectral evolution of supernovae with greater accuracy, with the ultimate goal being to develop a predictive classification system for supernova types.
description: Astro 98
Spill the Tea: Current Conditions and External Factors Affecting EnTEApreneurs in Lagawe, Ifugao, Philippines
Creators: name: Client William M. Malinao
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Access to Finance
Cultural Value
Entrepreneurship
Herb Tea EnTEApreneurs
One Town One Product
Product Potentials

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 35-54
Assessing the Potential for the Sustainable Development of the Lower Andaman Sub-region in Thailand Using AHP and PSA Techniques
Creators: name: Natthita Rojchanaprasart
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Potential Assessment
Sustainable Development
Lower Andaman Sub-region in Thailand

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 55-71
Baseline Data and Stakeholder Participation in Developing a Sustainable Tourism Economic Plan for the Lower Andaman Subregion (Krabi, Trang, and Satun Provinces) in Thailand
Creators: name: Supannee Keawchaum
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Tourism Economic Plan
Sustainable Development
Sustainable Tourism
Baseline Data
Stakeholder Participation
Lower Andaman Subregion Thailand

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 72-84
Improving Asteroid Family Age Estimation
Creators: name: Bae, Owen
Publisher: name: Zenodo
Year: 2024
Subjects: Astro 98

description: Asteroids are orbiting objects created from the leftover material of the formation of the solar system. The collision of asteroids are important and informative phenomena in the evolution and history of our solar system. An asteroid family is the group of asteroids that result from an asteroid collision, with those related objects having similar orbits post-collision. By analyzing the current dynamical state of asteroid families, the properties of Near Earth Asteroids (NEAs), and the gradually non-negligible effect of sunlight on the asteroids over millions of years (the so-called Yarkovsky effect), we can estimate when the collision that generated each asteroid family happened. By creating a history of collisions in the solar system, we gain insights into how the solar system (and then other planetary systems) form and evolve. Also, we can understand the mechanisms that transport asteroids from the main belt to the near-Earth region. This project focuses on the calculations of the ages of different asteroid families within the Main Asteroid Belt. This effort consists of improving the uncertainties in our age estimation, testing different possibilities, such as (i) using a more recent data-set; (ii) improving the calibration of the Yarkovsky effect and comparing the results with previous studies. A more accurate age estimation will help us better understand the collisional evolution of our solar system.
description: Astro 98
Modeling the Triple-Star System TOI-568 Using EXOFASTv2
Creators: name: Frommer, Arielle
Publisher: name: Zenodo
Year: 2024
Subjects: triple star systems
planetary systems
modeling tools
Astro 98

description: We present observations from the Transiting Exoplanet Survey Satellite (TESS), Tillinghast Reflector Echelle Spectrograph (TRES), and the Miniature Exoplanet Radial Velocity Array (MINERVA) of the false positive target TOI568 and provide best fit models for the data using EXOFASTv2. This object was labeled a TESS Object of Interest (TOI) by the mission due to the approximately 10-day transit observed; a secondary transit was also observed at around half of the period, suggesting a stellar companion around the host star. We spatially resolve two stars from AO imaging with a 0.29 arcsec separation, which corresponds to a minimum semimajor axis of approximately 140 AU given the stars’ distance of 700 pc and their masses. Provided with the semi-major axis, we calculate that the secondary star has a minimum period of roughly 700 years, leading us to conclude that a third body is present in the system to cause the 10-day transit. The lack of any recognizable radial velocity perturbations in the MINERVA and TRES data from the primary star suggests that the transit event instead occurs around the secondary star. We then use EXOFASTv2 to produce fits for the transit light curve, spectral energy distribution, and MIST evolutionary models of the three stars. We derive the stars to be around 5.27, 2.7, and 1.99 solar masses and 6.4, 4.4, and 4.1 solar radii, with temperatures of around 13,900 K, 8360 K, and 6530 K. The MIST models constrain the stars to be young massive stars, and at least one appears to be past the turnoff on the main sequence. In addition, we found an unusually low rotational velocity on the primary star of 8 km/s, which is much lower than expected from a B star and likely indicates that we are observing the star pole-on. The massive triple-star architecture coupled with the pole-on orientation make this system quite an interesting and complicated target that takes advantage of several new capabilities from EXOFASTv2, which has never previously been utilized to model a triple-star system. The models and parameters derived from EXOFASTv2’s fitting of this target serve as an excellent example of EXOFASTv2’s capabilities as a flexible modeling tool for probing the characteristics of stellar and planetary systems.
description: Astro 98
Adams operations and symmetries of representation categories
Creators: name: Meir, Ehud
name: Szymik, Markus
Publisher: name: arXiv
Year: 2017
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: Group Theory (math.GR)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics

description: Adams operations are the natural transformations of the representation ring functor on the category of finite groups, and they are one way to describe the usual lambda-ring structure on these rings. From the representation-theoretical point of view, they codify some of the symmetric monoidal structure of the representation category. We show that the monoidal structure on the category alone, regardless of the particular symmetry, determines all the odd Adams operations. On the other hand, we give examples to show that monoidal equivalences do not have to preserve the second Adams operations and to show that monoidal equivalences that preserve the second Adams operations do not have to be symmetric. Along the way, we classify all possible symmetries and all monoidal autoequivalences of representation categories of finite groups.
description: 20 pages, Indiana Univ. Math. J. (to appear)
Information Retrieval and Criticality in Parity-Time-Symmetric Systems
Creators: name: Kawabata, Kohei
name: Ashida, Yuto
name: Ueda, Masahito
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: By investigating information flow between a general parity-time (PT) -symmetric non-Hermitian system and an environment, we find that the complete information retrieval from the environment can be achieved in the PT-unbroken phase, whereas no information can be retrieved in the PT-broken phase. The PT-transition point thus marks the reversible-irreversible criticality of information flow, around which many physical quantities such as the recurrence time and the distinguishability between quantum states exhibit power-law behavior. Moreover, by embedding a PT-symmetric system into a larger Hilbert space so that the entire system obeys unitary dynamics, we reveal that behind the information retrieval lies a hidden entangled partner protected by PT symmetry. Possible experimental situations are also discussed.
description: 6+5 pages, 1+2 figures
Symbolic computation in hyperbolic programming
Creators: name: Naldi, Simone
name: Plaumann, Daniel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 14Q20, 68W30, 90C22, 90C25

description: Hyperbolic programming is the problem of computing the infimum of a linear function when restricted to the hyperbolicity cone of a hyperbolic polynomial, a generalization of semidefinite programming. We propose an approach based on symbolic computation, relying on the multiplicity structure of the algebraic boundary of the cone, without the assumption of determinantal representability. This allows us to design exact algorithms able to certify the multiplicity of the solution and the optimal value of the linear function.
description: Final version, published in the Journal of Algebra and its Applications (2017). 16 pages, 1 figure
From Tagalog to English: Pupils' Writing Proficiency Levels After Three Years in Mother Tongue-Based Multilingual Education
Creators: name: De Lemios, Ronald O.
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Writing Proficiency
First Language
Second Language
MTB-MLE

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 115-133
Causes and Consequences of Compulsive Buying Behavior: The Moderator Effects of Gender and Generation
Creators: name: Darunee Chalermjirapas
Publisher: name: Naresuan University Graduate School
Year: 2023
Subjects: Causes and Consequences
Compulsive Buying Behavior
Credit Card Debts
Credit Card Usage
Gender
Generation
Structural Equation Model (SEM)

description: Journal of Community Development Research (Humanities and Social Sciences), 16, 3, 134-153
A Host Property-Based Machine Learning Supernova Classifier
Creators: name: Boesky, Adam
name: Villar, Ashley
Publisher: name: Zenodo
Year: 2024
Subjects: supernova classification
machine learning
supernovae
surveys
galaxies
neural networks
random forests
Astro 98

description: Recent astronomical surveys have offered a large number of wide-field observations which will grow exponentially as the Vera C. Rubin Observatory begins its decade-long Legacy Survey of Space and Time. It is well known that the properties of galaxies are correlated with the classes of supernovae (SNe) that they host, implying that astronomers can use host galaxy properties to aid in SN classification. A particularly useful case is classifying young SNe with their host properties, as little information can be extracted from the few photometric observations taken in their short lifetimes. We present a novel machine learning pipeline that classifies SNe using the spectral energy distributions (SEDs) of their host galaxies. We infer host stellar mass, star formation rate, and redshift from the host  SEDs with a multilayer perceptron—a type of neural network. We then input these values and the host-supernova angular separation into a random forest (an ensemble learning method often used for classification) to produce a supernova classification. Our neural network infers galaxy properties quite well, producing log(M∗), log(SFR), and redshift predictions with mean fractional errors of 0.133 and root-mean-squared errors of 0.621. These are reasonable given that the measured uncertainty to value ratios of our dataset are 0.40, 0.25, and 0.83 for log(M∗), log(SFR), and redshift, respectively. Finally, our random forest performs comparably to other supernova classification methods, classifying type Ia SNe and other SNe with ∼ 97.5% and ∼ 55% purity, respectively, using 30% completeness. We believe that we can improve classification performance by expanding our dataset, which we plan to do in the coming weeks by conducting domain adaptation with galaxies from the Pan-STARRS catalog.
description: astro 98
Cosmological perturbation effects on gravitational-wave luminosity distance estimates
Creators: name: Bertacca, Daniele
name: Raccanelli, Alvise
name: Bartolo, Nicola
name: Matarrese, Sabino
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Waveforms of gravitational waves provide information about a variety of parameters for the binary system merging. However, standard calculations have been performed assuming a FLRW universe with no perturbations. In reality this assumption should be dropped: we show that the inclusion of cosmological perturbations translates into corrections to the estimate of astrophysical parameters derived for the merging binary systems. We compute corrections to the estimate of the luminosity distance due to velocity, volume, lensing and gravitational potential effects. Our results show that the amplitude of the corrections will be negligible for current instruments, mildly important for experiments like the planned DECIGO, and very important for future ones such as the Big Bang Observer.
description: 17 pages, 4 figures. Typos corrected; minor corrections; additional explanations added
Pixel-Scale Hα Mapping of z ∼ 4 − 5 Morphologically Complex JWST JADES Galaxies
Creators: name: Villaneuva, Natalia Cristina
Publisher: name: Zenodo
Year: 2023
Subjects: Astro 99

description: Early data from the JWST Advanced Deep Extragalactic Survey (JADES) Cycle 1 James Webb Space Telescope (JWST) observational program have already revolutionized our understanding of galaxy evolution and the properties of galaxy populations across cosmic time by allowing us to access information about these galaxies never seen before. In this study, we select 70 galaxies at redshift z ∼ 4 - 5 that exhibit excess flux in filter F356W, characteristic of redshifted Hα line emission. We probe the morphologies of star-forming regions of the galaxies by classifying the galaxies into four morphological categories, and from the comparison of Hα and rest-UV continuum emission maps. Ultimately, we present the difference image maps between Hα and rest-UV continuum emission for 5 galaxies, which are particularly chosen for their morphological complexity and multi-component structures that emphasize the advent of JWST's powerful spatial resolution of these high-redshift galaxies. We see evidence of how physical mechanisms such as mergers and interactions affect the formation of complex morphologies and star formation, supplemented by measurements of rest-frame Hα equivalent widths that probe the connections between bursty star-forming regions and their morphologies at z ∼ 4 - 5. Above all, this work lays the foundations for deeper quantitative studies that will further our understanding of star formation in this epoch of cosmic time.
description: Astro 99
Medium Stars with Big Attitudes: Testing the Effect of Stellar Activity in the Atmospheric Signals of Plants Transiting F-type Stars
Creators: name: Wurmser, Serena
Publisher: name: Zenodo
Year: 2023
Subjects: Astro 99

description: While our ability to observe and characterize exoplanet atmospheres has grown immensely in the past decade, stellar activity continues to present a major barrier towards a clear understanding of transmission spectra. Notably, there have been three exoplanets around F- type stars (WASP-121 b, WASP-79 b, and WASP-103 b) with quiet photometric curves but radial velocity (RV) plots that indicate activity, revealing the potential presence of faculæ. In this work, we explore how faculæ can present a source of contamination in transmission spectra of F-type stars by modifying SOAP 2.0, a code that simulates the effects of active regions on stars. We compare the activity indicators (i.e. bisector span, full width at half maximum) observed in these three F stars to the values modeled in SOAP 2.0 to determine if faculæ can cause the activity observed while not appearing in the star’s photometry. We find that it is plausible for widespread, hot faculæ to be present within observations of WASP-121 b, in contrast to prior studies that have rejected significant stellar activity as a source of contamination. We then explore the wide applicability of our method to other transiting exoplanet systems, focusing specifically on the case of TOI-1266—an M-dwarf with two planetary companions. Although stellar activity is historically not considered for transmission spectra around F stars, our results highlight a potential source of contamination that must be taken into account for other observations of transmission spectra in exoplanets around F stars. Further, we present a method that future studies can use to assess the likelihood that faculæ are contaminating transit observations—which can be applied to any system with F stars or smaller.
description: astro 99
Sequence dependent aggregation of peptides and fibril formation
Creators: name: Hung, Nguyen Ba
name: Le, Duy-Manh
name: Hoang, Trinh X.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Biomolecules (q-bio.BM)
subject: FOS: Biological sciences

description: Deciphering the links between amino acid sequence and amyloid fibril formation is key for understanding protein misfolding diseases. Here we use Monte Carlo simulations to study aggregation of short peptides in a coarse-grained model with hydrophobic-polar (HP) amino acid sequences and correlated side chain orientations for hydrophobic contacts. A significant heterogeneity is observed in the aggregate structures and in the thermodynamics of aggregation for systems of different HP sequences and different number of peptides. Fibril-like ordered aggregates are found for several sequences that contain the common HPH pattern while other sequences may form helix bundles or disordered aggregates. A wide variation of the aggregation transition temperatures among sequences, even among those of the same hydrophobic fraction, indicates that not all sequences undergo aggregation at a presumable physiological temperature. The transition is found to be the most cooperative for sequences forming fibril-like structures. For a fibril-prone sequence, it is shown that fibril formation follows the nucleation and growth mechanism. Interestingly, a binary mixture of peptides of an aggregation-prone and a non-aggregation-prone sequence shows association and conversion of the latter to the fibrillar structure. Our study highlights the role of sequence in selecting fibril-like aggregates and also the impact of structural template on fibril formation by peptides of unrelated sequences.
description: 11 pages, 10 figures
$k$-means as a variational EM approximation of Gaussian mixture models
Creators: name: Lücke, Jörg
name: Forster, Dennis
Publisher: name: arXiv
Year: 2017
Subjects: subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: 62H30

description: We show that $k$-means (Lloyd's algorithm) is obtained as a special case when truncated variational EM approximations are applied to Gaussian Mixture Models (GMM) with isotropic Gaussians. In contrast to the standard way to relate $k$-means and GMMs, the provided derivation shows that it is not required to consider Gaussians with small variances or the limit case of zero variances. There are a number of consequences that directly follow from our approach: (A) $k$-means can be shown to increase a free energy associated with truncated distributions and this free energy can directly be reformulated in terms of the $k$-means objective; (B) $k$-means generalizations can directly be derived by considering the 2nd closest, 3rd closest etc. cluster in addition to just the closest one; and (C) the embedding of $k$-means into a free energy framework allows for theoretical interpretations of other $k$-means generalizations in the literature. In general, truncated variational EM provides a natural and rigorous quantitative link between $k$-means-like clustering and GMM clustering algorithms which may be very relevant for future theoretical and empirical studies.
Breaking Lorentz reciprocity with frequency conversion and delay
Creators: name: Rosenthal, Eric I.
name: Chapman, Benjamin J.
name: Higginbotham, Andrew P.
name: Kerckhoff, Joseph
name: Lehnert, K. W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Classical Physics (physics.class-ph)
subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce a method for breaking Lorentz reciprocity based upon the non-commutation of frequency conversion and delay. The method requires no magnetic materials or resonant physics, allowing for the design of scalable and broadband non-reciprocal circuits. With this approach, two types of gyrators --- universal building blocks for linear, non-reciprocal circuits --- are constructed. Using one of these gyrators, we create a circulator with > 15 dB of isolation across the 5 -- 9 GHz band. Our designs may be readily extended to any platform with suitable frequency conversion elements, including semiconducting devices for telecommunication or an on-chip superconducting implementation for quantum information processing.
description: 5 page main text, 5 page supplement