cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Minimizing Flow Time in the Wireless Gathering Problem
Creators: name: Bonifaci, Vincenzo
name: Korteweg, Peter
name: Marchetti-Spaccamela, Alberto
name: Stougie, Leen
Publisher: name: arXiv
Year: 2008
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: We address the problem of efficient data gathering in a wireless network through multi-hop communication. We focus on the objective of minimizing the maximum flow time of a data packet. We prove that no polynomial time algorithm for this problem can have approximation ratio less than $Ω(m^{1/3)$ when $m$ packets have to be transmitted, unless $P = NP$. We then use resource augmentation to assess the performance of a FIFO-like strategy. We prove that this strategy is 5-speed optimal, i.e., its cost remains within the optimal cost if we allow the algorithm to transmit data at a speed 5 times higher than that of the optimal solution we compare to.
The Impact of Tandem Redundant/Sky-Based Calibration in MWA Phase II Data Analysis
Creators: name: Zhang, Zheng
name: Pober, Jonathan C.
name: Li, Wenyang
name: Hazelton, Bryna J.
name: Morales, Miguel F.
name: Trott, Cathryn M.
name: Jordan, Christopher H.
name: Joseph, Ronniy C.
name: Beardsley, Adam
name: Barry, Nichole
name: Byrne, Ruby
name: Tingay, Steven J.
name: Chokshi, Aman
name: Hasegawa, Kenji
name: Jacobs, Daniel C.
name: Lanman, Adam
name: Line, Jack L. B.
name: Lynch, Christene
name: McKinley, Benjamin
name: Mitchell, Daniel A.
name: Murray, Steven
name: Pindor, Bart
name: Rahimi, Mahsa
name: Takahashi, Keitaro
name: Wayth, Randall B.
name: Webster, Rachel L.
name: Wilensky, Michael
name: Yoshiura, Shintaro
name: Zheng, Qian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Precise instrumental calibration is of crucial importance to 21-cm cosmology experiments. The Murchison Widefield Array's (MWA) Phase II compact configuration offers us opportunities for both redundant calibration and sky-based calibration algorithms; using the two in tandem is a potential approach to mitigate calibration errors caused by inaccurate sky models. The MWA Epoch of Reionization (EoR) experiment targets three patches of the sky (dubbed EoR0, EoR1, and EoR2) with deep observations. Previous work in \cite{Li_2018} and \cite{Wenyang_2019} studied the effect of tandem calibration on the EoR0 field and found that it yielded no significant improvement in the power spectrum over sky-based calibration alone. In this work, we apply similar techniques to the EoR1 field and find a distinct result: the improvements in the power spectrum from tandem calibration are significant. To understand this result, we analyze both the calibration solutions themselves and the effects on the power spectrum over three nights of EoR1 observations. We conclude that the presence of the bright radio galaxy Fornax A in EoR1 degrades the performance of sky-based calibration, which in turn enables redundant calibration to have a larger impact. These results suggest that redundant calibration can indeed mitigate some level of model-incompleteness error.
description: 20 pages, 11 figures, accepted for publication in PASA
Energy distribution in the dyadosphere of a Reissner-Nordstrom black hole in Moller's prescription
Creators: name: Vagenas, Elias C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The energy and momentum distributions in the dyadosphere of a Reissner-Nordstrom black hole are evaluated. The Moller's energy-momentum complex is employed for this computation. The spacetime under study is modified due to the effects of vacuum fluctuations in the dyadosphere. Therefore, the corrected Reissner-Nordstrom black hole metric takes into account the first contribution of the weak field limit of one-loop QED. Furthermore, a comparison and a consequent connection between our results that those already existing in the literature is provided. We hypothesize that when the energy distribution is of specific form there is a relation that connects the coefficients in the Einstein's prescription with those in the Moller's prescription.
description: 12 pages, no figure, LaTeX
Parents’perceptions of the interpersonal aspects of care in a pediatric tertiary care neurosciences unit
Creators: name: Solomon, Loretta Margaret
Publisher: name: University of British Columbia
Year: 2009

description: This exploratory, descriptive study was designed to examine parents' perceptions of the interpersonal aspects of care-giving and to explore differences in parents' perceptions of care-giving according to their children's diagnoses and/or reason for hospitalization. The conceptual framework that guided this research is a set of priniciples developed by the Institute for Family Centered Care (Hanson, Johnson, Jeppson, Thomas & Hall, 1994) and is based on the belief that the family members are a major source of strength and support for their child, are experts about their child, and want to care for and nurture their child. The five major concepts that form this framework are respect, information sharing, collaboration, family-to-family support and confidence building. For this study, a convenience sample of parents (n=50) was recruited from a 20 bed neurosciences unit in a pediatric tertiary level hospital over an eight week period. Data were collected by means of a revised 56 item, five subscale self-report Measure of the Processes of Care (MPOC-R) questionnaire (King, Rosenbaum & King, 1996), and a socio-demographic tool. Data were analyzed using descriptive and parametric statistics. The study's findings indicate that during a particular period of time, parents reflect the views of a relatively satisfied group of consumers who view the interpersonal aspects of care-giving on this particular neurosciences unit positively. The findings reveal no differences in parents' perceptions of the interpersonal aspects of care-giving according to their children's diagnoses and/or reason for hospitalization. Suggestions for enhancing family-centered care include educational strategies, clinical practice changes and administrative support. Future research initiatives are presented.
On amenability of automata groups
Creators: name: Bartholdi, Laurent
name: Kaimanovich, Vadim A.
name: Nekrashevych, Volodymyr V.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics

description: We show that the group of bounded automatic automorphisms of a rooted tree is amenable, which implies amenability of numerous classes of groups generated by finite automata. The proof is based on reducing the problem to showing amenability just of a certain explicit family of groups ("Mother groups") which is done by analyzing the asymptotic properties of random walks on these groups.
Controlled Lagrangians and Potential Shaping for Stabilization of Discrete Mechanical Systems
Creators: name: Bloch, Anthony M.
name: Leok, Melvin
name: Marsden, Jerrold E.
name: Zenkov, Dmitry V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: The method of controlled Lagrangians for discrete mechanical systems is extended to include potential shaping in order to achieve complete state-space asymptotic stabilization. New terms in the controlled shape equation that are necessary for matching in the discrete context are introduced. The theory is illustrated with the problem of stabilization of the cart-pendulum system on an incline. We also discuss digital and model predictive control.
description: IEEE Conference on Decision and Control, 2006 6 pages, 4 figures
Forward and Back: Kinematics of the Palomar 5 Tidal Tails
Creators: name: Kuzma, Pete B.
name: Ferguson, Annette M. N.
name: Varri, Anna Lisa
name: Irwin, Michael J.
name: Bernard, Edouard J.
name: Tolstoy, Eline
name: Peñarrubia, Jorge
name: Zucker, Daniel B.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The tidal tails of Palomar 5 (Pal 5) have been the focus of many spectroscopic studies in an attempt to identify individual stars lying along the stream and characterise their kinematics. The well-studied trailing tail has been explored out to a distance of 15^\text{o} from the cluster centre, while less than four degrees have been examined along the leading tail. In this paper, we present results of a spectroscopic study of two fields along the leading tail that we have observed with the AAOmega spectrograph on the Anglo-Australian telescope. One of these fields lies roughly 7^\text{o} along the leading tail, beyond what has been previously been explored spectroscopically. Combining our measurements of kinematics and line strengths with Pan-STARRS1 photometric data and Gaia EDR3 astrometry, we adopt a probabilistic approach to identify 16 stars with high probability of belonging to the Pal 5 stream. Eight of these stars lie in the outermost field and their sky positions confirm the presence of ``fanning'' in the leading arm. We also revisit previously-published radial velocity studies and incorporate Gaia EDR3 astrometry to remove interloping field stars. With a final sample of 109 {\it bona fide} Pal 5 cluster and tidal stream stars, we characterise the 3D kinematics along the the full extent of the system. We provide this catalogue for future modeling work.
description: 13 pages, 8 figures, accepted for publication in MNRAS. The extended version of Table 4 is available as an ancillery file, and will be supplementary material in MNRAS
ศักยภาพของอินโฟกราฟิก (Infographic) ในการเพิ่มคุณภาพการเรียนรู้
Creators: name: พัชรา วาณิชวศิน
Publisher: name: สถาบันการจัดการปัญญาภิวัฒน์
Year: 2558
Subjects: ศักยภาพ, อินโฟกราฟิก, คุณภาพการเรียนรู้

description: พิเศษ, 7, วารสารปัญญาภิวัฒน์
Direct Observation of Spectroscopic Inhomogeneities on La0.7Sr0.3MnO3 Thin Films by Scanning Tunnelling Spectroscopy
Creators: name: Di Capua, R.
name: Perroni, C. A.
name: Cataudella, V.
name: Granozio, F. Miletto
name: Perna, P.
name: Salluzzo, M.
name: Di Uccio, U. Scotti
name: Vaglio, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Scanning tunnelling spectroscopy measurements were performed on La0.7Sr0.3MnO3 thin films both at room temperature and liquid nitrogen temperature. While no inhomogeneities were recorded at liquid nitrogen temperature on any sample, a clear evidence of spectroscopic inhomogeneities was evident in tunnelling conductance maps collected at room temperature. The investigated films exhibit a transition from a ferromagnetic-metallic to a paramagnetic-insulating state around room temperature, so that the observed spectroscopic features can be interpreted within a phase separation scenario. A quantitative analysis of the observed spectroscopic features is reported pointing out the occurrence of phase modulation and its possible correlation with the properties of the system.
Quantum Analysis of BTZ Black Hole Formation Due to the Collapse of a Dust Shell
Creators: name: Andrianov, Alexander A.
name: Starodubtsev, Artem
name: Elmahalawy, Yasser
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We perform Hamiltonian reduction of a model in which 2+1 dimensional gravity with negative cosmological constant is coupled to a cylindrically symmetric dust shell. The resulting action contains only a finite number of degrees of freedom. The phase space consists of two copies of $ADS^2$ -- both coordinate and momentum space are curved. Different regions in the Penrose diagram can be identified with different patches of $ADS^2$ momentum space. Quantization in the momentum representation becomes particularly simple in the vicinity of the horizon, where one can neglect momentum non-commutativity. In this region, we calculate the spectrum of the shell radius. This spectrum turns out to be continuous outside the horizon and becomes discrete inside the horizon with eigenvalue spacing proportional to the square root of the black hole mass. We also calculate numerically quantum transition amplitudes between different regions of the Penrose diagram in the vicinity of the horizon. This calculation shows a possibility of quantum tunneling of the shell into classically forbidden regions of the Penrose diagram, although with an exponentially damped rate away from the horizon.
description: 19 pages, 3 figures
จุดประกาย
Creators: name: ธนาสิทธิ์ เพิ่มเพียร
Publisher: name: สถาบันการจัดการปัญญาภิวัฒน์
Year: 2558
Subjects: แบรนด์นายจ้าง, การจัดการทรัพยากรมนุษย์, การสรรหาทรัพยากรมนุษย์, การรักษาทรัพยากรมนุษย์

description: พิเศษ, 7, วารสารปัญญาภิวัฒน์
MO'G'UL IMPERYASINI TASHKIL ETILISHI VA DASTLABKI BOSHQARUV TIZIMI
Creators: name: Zokirov, Zohidjon
Publisher: name: Zenodo
Year: 2024

description: O‘rta asrlar manbalarining ma'lumotlariga ko‘ra, XII asr oxiri XIII asr boshlarida mo‘g‘ul qabilalari va elatlarining qudratli davlatga birlashuvi jarayonlari bo‘lib o‘tadi. Yozma manbalarda mo‘g‘ullar menu(menva) nomi bilan ilk marotaba Xitoyning Tan sulolasi (618-908 y.y.) solnomasida tilga olinadi. Aksariyat manbalarda mo‘g‘ullarning birlashuv jarayonlari Temuchin nomi bilan bog‘lanadi.Temuchin, bo‘lg‘usi Chingizxon ayrim tarixiy manbalarda 1162-yilda, yana ayrimlarida 1155-yilda tug‘ilgan deb ko‘rsatiladi[1]. U tug‘ilgan vaqtda otasi Yesugey-bahodir tatarlar yo'lboshchisi Temuchin – ugeni mag‘lub etgani sabab, o‘z o‘g‘liga o‘sha mag‘lub dushman nomini beradi
N-Algebraic Structures and S-N-Algebraic Structures
Creators: name: Kandasamy, W. B. Vasantha
name: Smarandache, Florentin
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics
subject: 16-xx

description: For the first time, we have introduced the concept of N-groups, N-semigroups, N-loops, and N-groupoids. We also define a mixed N-algebraic structure. The main aim of this book is to attract young mathematicians to this interesting field. It contains more than 200 new definitions. These concepts find applications in fields like finite automaton, coloring problems and coding theory.
description: 209 pages, over 200 definitions
ระบบสารสนเทศเพื่อการจัดการ สำหรับการบริหารสถาบันอุดมศึกษาที่เป็นการศึกษาอิเล็กทรอนิกส์
Creators: name: อุราเพ็ญ ยิ้มประเสริฐ
name: รพีพร ตันจ้อย
Publisher: name: สถาบันการจัดการปัญญาภิวัฒน์
Year: 2558
Subjects: ระบบสารสนเทศเพื่อการจัดการ, การศึกษาอิเล็กทรอนิกส์

description: พิเศษ, 7, วารสารปัญญาภิวัฒน์
สื่อ-ผู้คน: การส่งความฝัน ความหวัง และอนาคตในวิถีญี่ปุ่น
Creators: name: นงลักษณ์ ลิ้มศิริ
Publisher: name: สถาบันการจัดการปัญญาภิวัฒน์
Year: 2558
Subjects: ญี่ปุ่น, แผ่นดินไหว, สื่อญี่ปุ่น

description: พิเศษ, 7, วารสารปัญญาภิวัฒน์
Bridging the gap between collisional and collisionless shock waves
Creators: name: Bret, Antoine
name: Pe'er, Asaf
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: While the front of a fluid shock is a few mean-free-paths thick, the front of a collisionless shock can be orders of magnitude thinner. By bridging between a collisional and a collisionless formalism, we assess the transition between these two regimes. We consider non-relativistic, un-magnetized, planar shocks in electron/ion plasmas. In addition, our treatment of the collisionless regime is restricted to high Mach number electrostatic shocks. We find that the transition can be parameterized by the upstream plasma parameter $Λ$ which measures the coupling of the upstream medium. For $Λ\lesssim 1.12$, the upstream is collisional, i.e. strongly coupled, and the strong shock front is about $\mathcal{M}_1 λ_{\mathrm{mfp},1}$ thick, where $λ_{\mathrm{mfp},1}$ and $\mathcal{M}_1 $ are the upstream mean-free-path and Mach number respectively. A transition occurs for $Λ\sim 1.12$ beyond which the front is $\sim \mathcal{M}_1λ_{\mathrm{mfp},1}\ln Λ/Λ$ thick for $Λ\gtrsim 1.12$. Considering $Λ$ can reach billions in astrophysical settings, this allows to understand how the front of a collisionless shock can be orders of magnitude smaller than the mean-free-path, and how physics transitions continuously between these 2 extremes.
description: 13 pages, 4 figures, Under consideration for publication in J. Plasma Phys
RESEARCH FOR MANAGEMENT PROBLEM AND COUNTERMEASURE ON THE WUHAN MUSEUM
Creators: name: Zhou, Jing
name: Hongyan Shang
name: Tansiny Lertsiriworapong
Publisher: name: สถาบันการจัดการปัญญาภิวัฒน์
Year: 2558
Subjects: Museums, Management, Systems, Countermeasures

description: พิเศษ, 7, วารสารปัญญาภิวัฒน์
SENSITIVITY ANALYSIS OF E-COMMERCE AND LOGISTICS FACTORS
Creators: name: Hongyan Shang
name: Pak Thaldumrong
name: Tansiny Lertsiriworapong
Publisher: name: สถาบันการจัดการปัญญาภิวัฒน์
Year: 2558
Subjects: E-commerce Logistics Time, Logistics Cost, Logistics Method Sensitivity

description: พิเศษ, 7, วารสารปัญญาภิวัฒน์
Magnetic field strength in cosmic web filaments
Creators: name: Carretti, E.
name: Vacca, V.
name: O'Sullivan, S. P.
name: Heald, G. H.
name: Horellou, C.
name: Rottgering, H. J. A.
name: Scaife, A. M. M.
name: Shimwell, T. W.
name: Shulevski, A.
name: Stuardi, C.
name: Vernstrom, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We used the Rotation Measure (RM) catalogue derived from the LOFAR Two-metre Sky Survey Data Release 2 (LoTSS DR2) at 144-MHz to measure the evolution with redshift of the extragalactic RM (RRM: Residual RM) and the polarization fraction ($p$) of sources in low density environments. We also measured the same at 1.4-GHz by cross-matching with the NRAO VLA Sky Survey RM catalogue. We find that RRM versus redshift is flat at 144-MHz, but, once redshift-corrected, it shows evolution at high significance. Also $p$ evolves with redshift with a decrement by a factor of $\sim$8 at $z\sim2$. Comparing the 144-MHz and 1.4-GHz data, we find that the observed RRM and $p$ are most likely to have an origin local to the source at 1.4-GHz, while a cosmic web filament origin is favoured at 144-MHz. If we attribute the entire signal to filaments, we infer a mean rest frame RRM per filament of RRM_{0,f} = 0.71 \pm 0.07 rad m^{-2} and a magnetic field per filament of B_f = 32 \pm 3 nG. This is in agreement with estimates obtained with a complementary method based on synchrotron emission stacking, and with cosmological simulations if primordial magnetic fields are amplified by astrophysical source field seeding. The measurement of an RRM_{0,f} supports the presence of diffuse baryonic gas in filaments. We also estimated a conservative upper limit of the filament magnetic turbulence of σ_{ RRM_{0,f}} =0.039 \pm 0.001 rad m^{-2}, concluding that the ordered magnetic field component dominates in filaments.
description: Accepted for publication on MNRAS
Dynamical horizons and Super-Translation transitions of the horizon
Creators: name: Chatterjee, Ayan
name: Ghosh, Avirup
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A condition is defined which determines if a supertranslation is induced in the course of a general evolution from one isolated horizon phase to another via a dynamical horizon. This condition fixes preferred slices on an isolated horizon and is preserved along an Isolated Horizon. If it is not preserved, in the course of a general evolution, then a supertranslation will be said to have been induced. A simple example of spherically symmetric dynamical horizons is studied to illustrate the conditions for inducing supertranslations.
description: 18 pages, 3 figures
A very low central oxygen mass in the peculiar type Ia SN 2010lp: further diversity at the low-luminosity end of SNe Ia
Creators: name: Mazzali, P. A.
name: Benetti, S.
name: Stritzinger, M.
name: Ashall, C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A nebular spectrum of the peculiar, low-luminosity type Ia supernova 2010lp is modelled in order to estimate the composition of the inner ejecta and to illuminate the nature of this event. Despite having a normally declining light curve, SN 2010lp was similar spectroscopically to SN 1991bg at early times. However, it showed a very unusual double-peaked [OI] $λλ\,6300,6363$ emission at late times (Taubenberger et al. 2013). Modelling of the nebular spectrum suggests that a very small amount of oxygen ($\sim0.05$ M$_{\odot}$), expanding at very low speed ($\sim2000$ km/s) is sufficient to reproduce the observed emission. The rest of the nebula is not too dissimilar from SN 1991bg, except that SN 2010lp is slightly more luminous. The double-peaked [OI] emission suggests that SN 2010lp may be consistent with the merger or collision of two low-mass white dwarfs. The low end of the SN Ia luminosity sequence is clearly populated by diverse events, where different channels may contribute.
description: Accepted for publication in MNRAS
Factoring Polynomials over Finite Fields using Balance Test
Creators: name: Saha, Chandan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: We study the problem of factoring univariate polynomials over finite fields. Under the assumption of the Extended Riemann Hypothesis (ERH), (Gao, 2001) designed a polynomial time algorithm that fails to factor only if the input polynomial satisfies a strong symmetry property, namely square balance. In this paper, we propose an extension of Gao's algorithm that fails only under an even stronger symmetry property. We also show that our property can be used to improve the time complexity of best deterministic algorithms on most input polynomials. The property also yields a new randomized polynomial time algorithm.
Reducing the uncertainty in ¹¹⁵ᵐCd gamma-ray branching ratios
Creators: name: Gordon, Emily Margaret
name: 0000-0002-1608-956X
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: Nuclear forensics
Gamma-ray branching ratios
Gamma-ray intensities
Nuclear data

description: The isotope ¹¹⁵ᵐCd is an important fission product in nuclear forensics due to its fission yield and relatively long half-life. Currently, analysis procedures for the assay of ¹¹⁵ᵐCd are limited to β⁻ detection due to high uncertainty in the gamma-ray branching ratios. To facilitate the use of gamma spectroscopy in ¹¹⁵ᵐCd analysis, the gamma-ray branching ratio data for the isotope was improved. The relevant uncertainties were reduced significantly by first producing a sample of ¹¹⁵ᵐCd , then combining gamma spectroscopy and β⁻ counting to find the gamma emission rate for a set of gamma-ray energies, and β⁻ emission rate to determine total activity. The data was then used in conjunction with a specially developed analysis procedure to yield the gamma-ray branching ratios with uncertainty ≤5%.
Spin Hall effect of light in inhomogeneous axion field
Creators: name: Hoseini, Mansoureh
name: Mehrafarin, Mohammad
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the spin transport of light in weakly inhomogeneous axion field in a flat Robertson-Walker universe and derive the spin Hall effect for circularly polarized rays. Regarding primordial quantum fluctuations of the axion field in the de Sitter phase as the origin of the inhomogeneity, we show that the conformal invariance of the correlator determines the root-mean-square (r.m.s) fluctuations of the path of circularly polarized cosmic rays. We explain how the r.m.s fluctuations can be experimentally determined.
description: To appear in Phys. Lett. B
Virtual Laboratories
Creators: name: Hut, Piet
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: At the frontier of most areas in science, computer simulations play a central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simulated dialogues between code developers, thus sharing not only the code, but also the motivations behind the code.
description: to appear in Prog. Theor. Phys
Activity-based models to predict kinetics of levulinic acid esterification
Creators: name: Klinksiek, Marcel
name: Baco, Sindi
name: Leveneur, Sébastien
name: Legros, Julien
name: Held, Christoph
Publisher: name: TU Dortmund
Year: 2022
Subjects: subject: Catalyst effect
subject: ePC-SAFT advanced
subject: GVL
subject: Proton activity
subject: Solvent effect
subject: Thermodynamics
subject: 660

description: The solvent is of prime importance in biomass conversion as it influences dissolution, reaction kinetics, catalyst activity and thermodynamic equilibrium of the reaction system. So far, activity-based models were developed to predict kinetics and equilibria, but the influence of the catalyst on kinetics has not been succesfully predicted by thermodynamic models. In this work, the thermodynamic model ePC-SAFT advanced was used to predict the activities of the reactants and of the catalyst at various conditions (temperature, reactant concentrations, γ-valerolactone GVL cosolvent addition, catalyst concentration) for the homogeneously acid-catalyzed esterification of levulinic acid (LA) with ethanol. Different kinetic models were applied, and it was found that the catalyst influence on kinetics could be predicted correctly by simultaneously solving the dissociation equilibrium of H2SO4 catalyst along the reaction coordinate and by relating reaction kinetics to proton activity. ePC-SAFT advanced model parameters were only fitted to reaction-independent phase equilibrium data. The key reaction properties were determined by applying ePC-SAFT advanced to one experimental kinetic curve for a set of temperatures, yielding the reaction enthalpy at standard state urn:x-wiley:14394235:media:cphc202200729:cphc202200729-math-0001 , activation energy urn:x-wiley:14394235:media:cphc202200729:cphc202200729-math-0002 and the intrinsic reaction rate constant k=0.011 s−1 at 323 K, which is independent of catalyst concentration. The new procedure allowed an a-priori identification of the effects of catalyst, solvent and reactant concentration on LA esterification.
description: ChemPhysChem;24(4)
Revisiting the evolved hypergiants in the Magellanic Clouds
Creators: name: Kourniotis, Michalis
name: Kraus, Michaela
name: Maryeva, Olga
name: Fernandes, Marcelo Borges
name: Maravelias, Grigoris
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The massive stars that survive the phase of red supergiants (RSGs) spend the rest of their life in extremity. Their unstable atmospheres facilitate the formation and episodic ejection of shells that alter the stellar appearance and surroundings. In the present study, we revise the evolutionary state of eight hypergiants in the Magellanic Clouds, four of early-A type and four of FG type, and complement the short list of the eruptive post-RSGs termed as yellow hypergiants (YHGs). We refine the outdated temperatures and luminosities of the stars by means of high-resolution spectroscopy with FEROS. The A-type stars are suggested to be in their early, post-main sequence phase, showing spectrophotometric characteristics of redward evolving supergiants. On the other hand, the FG-type stars manifest themselves through the enhanced atmospheric activity that is traced by emission filling in H$α$ and the dynamical modulation of the low-excitation BaII line. Of these stars, the dusty HD269723 is suggested to have recently departed from a cool phase. We identify double-peaked emission in the FEROS data of HD269953 that emerges from an orbiting disk-hosting companion. The highlight of the study is an episode of enhanced mass loss of HD271182 that manifests as a dimming event in the lightcurve and renders the star "modest" analogue to $ρ$ Cas. The luminosity $\log(L/L_{\odot})= 5.6$ of HD271182 can serve as an updated threshold for the luminosity of stars exhibiting a post-RSG evolution in the Large Magellanic Cloud.
description: 17 pages, 14 figures, 7 tables. Accepted for publication in MNRAS
On Termination for Faulty Channel Machines
Creators: name: Bouyer, Patricia
name: Markey, Nicolas
name: Ouaknine, Joël
name: Schnoebelen, Philippe
name: Worrell, James
Publisher: name: arXiv
Year: 2008
Subjects: subject: Information Theory (cs.IT)
subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences

description: A channel machine consists of a finite controller together with several fifo channels; the controller can read messages from the head of a channel and write messages to the tail of a channel. In this paper, we focus on channel machines with insertion errors, i.e., machines in whose channels messages can spontaneously appear. Such devices have been previously introduced in the study of Metric Temporal Logic. We consider the termination problem: are all the computations of a given insertion channel machine finite? We show that this problem has non-elementary, yet primitive recursive complexity.
The Thresher: Lucky Imaging without the Waste
Creators: name: Hitchcock, James A.
name: Bramich, D. M.
name: Foreman-Mackey, Daniel
name: Hogg, David W.
name: Hundertmark, Markus
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In traditional lucky imaging (TLI), many consecutive images of the same scene are taken with a high frame-rate camera, and all but the sharpest images are discarded before constructing the final shift-and-add image. Here we present an alternative image analysis pipeline -- The Thresher -- for these kinds of data, based on online multi-frame blind deconvolution. It makes use of all available data to obtain a best estimate of the astronomical scene in the context of reasonable computational limits; it does not require prior estimates of the point-spread functions in the images, or knowledge of point sources in the scene that could provide such estimates. Most importantly, the scene it aims to return is the optimum of a justified scalar objective based on the likelihood function. Because it uses the full set of images in the stack, The Thresher outperforms TLI in signal-to-noise; as it accounts for the individual-frame PSFs, it does this without loss of angular resolution. We demonstrate the effectiveness of our algorithm on both simulated data and real Electron-Multiplying CCD images obtained at the Danish 1.54m telescope (hosted by ESO, La Silla). We also explore the current limitations of the algorithm, and find that for the choice of image model presented here, non-linearities in flux are introduced into the returned scene. Ongoing development of the software can be viewed at https://github.com/jah1994/TheThresher.
description: 14 pages, 9 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society
Is the 2-Flavor Chiral Transition of First Order?
Creators: name: Digal, Sanatan
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the effects of the interaction between the Chiral condensate and the Polyakov loop on the chiral transition within an effective Lagrangian. We find that the effects of the interaction change the order of the phase transition when the explicit breaking of the Z_N symmetry of the Polyakov loop is large. Our results suggest that the chiral transition in 2-flavor QCD may be first order.
description: 8 pages with 4 figures
Enti locali e società di capitali nella gestione di servizi pubblici locali e strumentali
Local authorities and corporations in the management of local public services and instrumental services
Creators: name: Imola, Ilenia <1981>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: IUS/10 Diritto amministrativo

description: La gestione di servizi pubblici locali e di servizi strumentali tramite società di capitali partecipate da enti locali viene esplorata in vista di una riconsiderazione generale del sistema all'interno del contesto socio-economico sviluppatosi negli anni successivi alla crisi economica mondiale dell'anno 2008.
description: The management of local public services and instrumental services used by corporations owned by local authorities is explored in view of a general reappraisal of the system within the socio-economic context has developed in the years following the global economic crisis of 2008.
On the density of properly maximal claims in financial markets with transaction costs
Creators: name: Jacka, Saul
name: Berkaoui, Abdelkarem
Publisher: name: arXiv
Year: 2006
Subjects: subject: Probability (math.PR)
subject: Optimization and Control (math.OC)
subject: Computational Finance (q-fin.CP)
subject: FOS: Mathematics
subject: FOS: Economics and business
subject: 91B28 (Primary); 52A07, 60H05, 91B26, 90C29 (Secondary)

description: We consider trading in a financial market with proportional transaction costs. In the frictionless case, claims are maximal if and only if they are priced by a consistent price process--the equivalent of an equivalent martingale measure. This result fails in the presence of transaction costs. A properly maximal claim is one which does have this property. We show that the properly maximal claims are dense in the set of maximal claims (with the topology of convergence in probability).
description: Published at http://dx.doi.org/10.1214/105051606000000880 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Controlling wave-front shape and propagation time with tunable disordered non-Hermitian multilayers
Creators: name: Novitsky, Denis
name: Lyakhov, Dmitry
name: Michels, Dominik
name: Redka, Dmitrii
name: Pavlov, Alexander
name: Shalin, Alexander
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Unique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales. Together with an increasing demand for the fast and spatially compact methods of light governing, this peculiar approach paves a broad avenue to novel optical applications. Here, unifying the approaches of disordered metamaterials and non-Hermitian photonics, we propose a conceptually new and simple architecture driven by disordered loss-gain multilayers and, therefore, providing a powerful tool to control both the passage time and the wave-front shape of incident light with different switching times. For the first time we show the possibility to switch on and off kink formation by changing the level of disorder in the case of adiabatically raising wave fronts. At the same time, we deliver flexible tuning of the output intensity by using the nonlinear effect of loss and gain saturation. Since the disorder strength in our system can be conveniently controlled with the power of the external pump, our approach can be considered as a basis for different active photonic devices.
description: 8 pages, 7 figures
The strongly irradiated planets in Praesepe
Creators: name: King, George W.
name: Wheatley, Peter J.
name: Fawcett, Victoria A.
name: Miller, Nicola J.
name: Corrales, Lía R.
name: Agüeros, Marcel A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present an analysis of XMM-Newton observations of four stars in the young (670 Myr) open cluster Praesepe. The planets hosted by these stars all lie close in radius-period space to the radius-period valley and/or the Neptunian desert, two features that photoevaporation by X-ray and extreme ultraviolet (EUV) photons could be driving. Although the stars are no longer in the saturated regime, strong X-ray and extreme ultraviolet irradiation is still ongoing. Based on EUV time evolution slopes we derived in a previous paper, in all four cases, two-thirds of their EUV irradiation is still to come. We compare the XMM-Newton light curves to those simultaneously measured with K2 at optical wavelengths, allowing us to search for correlated variability between the X-ray and optical light curves. We find that the X-ray flux decreases and flattens off while the optical flux rises throughout for K2-100, something that could result from active regions disappearing from view as the star spins. Finally, we also investigate possible futures for the four planets in our sample with simulations of their atmosphere evolution still to come, finding that complete photoevaporative stripping of the envelope of three of the four planets is possible, depending on the current planet masses.
description: 15 pages, 12 figures, 7 tables; accepted for publication in MNRAS
Energy-Constrained Delivery of Goods with Drones Under Varying Wind Conditions
Creators: name: Sorbelli, Francesco Betti
name: Corò, Federico
name: Das, Sajal K.
name: Pinotti, Cristina M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: In this paper, we study the feasibility of sending drones to deliver goods from a depot to a customer by solving what we call the Mission-Feasibility Problem (MFP). Due to payload constraints, the drone can serve only one customer at a time. To this end, we propose a novel framework based on time-dependent cost graphs to properly model the MFP and tackle the delivery dynamics. When the drone moves in the delivery area, the global wind may change thereby affecting the drone's energy consumption, which in turn can increase or decrease. This issue is addressed by designing three algorithms, namely: (i) compute the route of minimum energy once, at the beginning of the mission, (ii) dynamically reconsider the most convenient trip towards the destination, and (iii) dynamically select only the best local choice. We evaluate the performance of our algorithms on both synthetic and real-world data. The changes in the drone's energy consumption are reflected by changes in the cost of the edges of the graphs. The algorithms receive the new costs every time the drone flies over a new vertex, and they have no full knowledge in advance of the weights. We compare them in terms of the percentage of missions that are completed with success (the drone delivers the goods and comes back to the depot), with delivered (the drone delivers the goods but cannot come back to the depot), and with failure (the drone neither delivers the goods nor comes back to the depot).
description: typo author's name
Isotopic Separation of Helium through Nanoporous Graphene Membranes: A Ring Polymer Molecular Dynamics Study
Creators: name: Bhowmick, Somnath
name: Hernández, Marta I.
name: Campos-Martínez, José
name: Suleimanov, Yury V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Microscopic-level understanding of the separation mechanism for two-dimensional (2D) membranes is an active area of research due to potential implications of this class of membranes for various technological processes. Helium (He) purification from the natural resources is of particular interest due to the shortfall in its production. In this work, we applied the ring polymer molecular dynamics (RPMD) method to graphdiyne (Gr2) and graphtriyne (Gr3) 2D membranes having variable pore sizes for the separation of He isotopes. We found that the transmission rate through Gr3 is many orders of magnitude greater than Gr2. The selectivity of either isotope at low temperatures is a consequence of a delicate balance between the zero-point energy effect and tunneling of $^4$He and $^3$He. RPMD provides an efficient approach for studying the separation of He isotopes, taking into account quantum effects of light nuclei motions at low temperatures, which classical methods fail to capture.
AstroSat Detection of a Quasi-periodic Oscillation at ~ 42 Hz in Cygnus X-2
Creators: name: Chhangte, Vanzarmawii
name: Roy, Jayashree
name: Misra, Ranjeev
name: Zadeng, Lalthakimi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the results of AstroSat observations of Cygnus X-2 during February 2016. The source's power density spectrum generated using LAXPC data revealed the presence of a prominent Quasi-periodic Oscillation (QPO) at $\sim42$ Hz with broadband continuum noise at lower frequencies at $\sim10$ Hz. The large effective area of LAXPC at $\gtrsim$30 keV allowed for an unprecedented study of the energy dependence of the QPO and the broad noise continuum. The fractional r.m.s increases with energy, and its shape is similar for both the QPO and the continuum noise, suggesting a common radiative origin. However, while the QPO exhibits hard time lags, with the high energy photons lagging the low ones by a few milliseconds, the continuum noise shows the opposite behavior. The photon spectrum from SXT and LAXPC in $0.7-30$ keV band comprises the soft component from a disc and a hard Comptonized component from a hot corona. While the energy dependence of the r.m.s shows that the QPO and the continuum noise variability are dominated by the Comptonized component, the change in sign of the time-lag suggests that the dynamic origin of the QPO may be in the disk while the noise continuum may originate from the corona.
description: 5 pages, 5 figures, accepted for publication in MNRAS Letter
Die Kirche auf dem Maidan: Die Macht des gesellschaftlichen Wandels
Creators: name: Hovorun, Cyril
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 63 Nr. 3 (2014): Ökumenische Rundschau, Band 63, Heft 3
Substantial changes of economic policy and strategy in the People’s Republic of China and the Republic of China on Taiwan : a comparative study
Creators: name: Shih, Philbert Han-Yeung
Publisher: name: University of British Columbia
Year: 2009

description: This thesis focuses on an isolated subset of cases where governments have made decisions to substantially change economic development policy and strategy. The two countries under consideration are the Republic of China on Taiwan and the People's Republic of China. The initiation of market opening reforms in China during the late 1970s/early 1980s, the transition to export-led growth strategies during the late 1950s/early 1960s, and the postwar land reform in Taiwan constitute three specific cases of economic policy change. This thesis will attempt to compare and contrast these cases in the hopes of uncovering the underlying rationales explaining the initation of policy change in China and Taiwan, illuminating some of their important similarities and differences. This thesis will also attempt to draw some theoretical conclusions concerning economic policy change from these unique experiences. The conclusion presented in this thesis argues that in the cases considered, the sources of economic policy change are multi-causal. Economic, political, international, ideational, and institutional factors are interrelated and together explain economic policy changes. The interrelationships between these variables are elucidated most clearly when particular attention is paid to the political and economic contexts surrounding instances of policy change. In short, it is the mufti-causal nature of economic policy change that confirms the insufficiency of exclusively economic explanations of economic policy change.
An observational synthesis of the Taurid meteor complex
Creators: name: Egal, A.
name: Brown, P. G.
name: Wiegert, P.
name: Kipreos, Y.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We provide an overview of the observational properties of the four major Taurid showers, namely the Northern and Southern Taurids (#017 NTA and #002 STA), the Beta Taurids (#173 BTA) and the Zeta Perseids (#172 ZPE). Analysing more than two decades of meteor observations from visual, optical and radar measurements we present the Taurids average activity, annual variations in strength, radiant drift and orbital variations as a function of solar longitude and particle size. The Taurid showers are detected over several weeks in the spring and autumn, but their annual activity level is generally low (less than 15 visual meteors per hour). We find the STA to be predominant in autumn, while its twin the ZPE dominates over the BTA in spring. Due to their long duration, the position of each shower's radiant and orbital elements are variable with time. Optical measurements have previously recorded enhanced STA activity and increased fireball rates caused by the return of a swarm of meteoroids trapped in the 7:2 mean motion resonance with Jupiter. However, we find no presence of the swarm in radar data, suggesting that small meteoroids are removed from the resonance faster than fireball-producing meteoroids. We also find the STA to be enriched in smaller particles early in their activity period. The differences we identify in our analysis between the showers at different particle sizes provide strong observational constraints to future dynamical modelling of the Taurid Meteoroid Complex.
description: Accepted for publication in MNRAS (Acceptation date: 2022 February 10)
Elicitation of animals
Creators: name: Hien, Sansan Claude
name: Sande, Hannah
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: lob

description: 1 MP4, 1 PDF file. Class conducted on Zoom during two-week period of virtual class meetings at outset of Spring 2022 semester due to the COVID-19 pandemic.