cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Weighted Linear Dynamic Logic
Creators: name: Droste, Manfred
name: Rahonis, George
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We introduce a weighted linear dynamic logic (weighted LDL for short) and show the expressive equivalence of its formulas to weighted rational expressions. This adds a new characterization for recognizable series to the fundamental Schützenberger theorem. Surprisingly, the equivalence does not require any restriction to our weighted LDL. Our results hold over arbitrary (resp. totally complete) semirings for finite (resp. infinite) words. As a consequence, the equivalence problem for weighted LDL formulas over fields is decidable in doubly exponential time. In contrast to classical logics, we show that our weighted LDL is expressively incomparable to weighted LTL for finite words. We determine a fragment of the weighted LTL such that series over finite and infinite words definable by LTL formulas in this fragment are definable also by weighted LDL formulas.
description: In Proceedings GandALF 2016, arXiv:1609.03648
Deciphering the Functional Redundancy of USP4 and USP15
Creators: name: Zachariah, Sarah
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2020
Subjects: Deubiquitinating enzymes
Molecular evolution
Functional redundancy

description: The deubiquitinating enzymes USP4 and USP15 are encoded by genes that are ohnologues arising from whole genome duplication events early in vertebrate evolution, and the majority of known vertebrate genomes contain a functional copy of both. Both USPs are known to be involved in some of the same signalling pathways such as Wnt/β-catenin, however subfunctionalization has occurred such that they each regulate the stability of distinct substrates. Despite their sequence and evolutionary similarities, the ohnologues may have opposite correlations in overall survival of lung adenocarcinoma patients. Early work with knockout mice has determined that while mice null in one ohnologue display no phenotype, the double null genotype is lethal. We hypothesize that there are mechanisms in place that allow one to perform the other’s functions to a certain extent when deficient in one USP. To study the extent of this functional redundancy, we are analyzing the progeny of genetic crosses of mice in which one or both genes have been inactivated. There is evidence for partial functional redundancy and more severe phenotypes when deficient in USP15. Embryos null for both genes die at midgestation and are physically smaller than embryos heterozygous for both genes. They have underdeveloped livers, and a likely defect in hematopoiesis. Proper fetal hematopoiesis requires signalling through Wnt/ β-catenin pathway, and a systematic analysis of the components of this pathway has been undertaken to correlate deficiencies with the genotypes of our knockout mice. There also may be preliminary evidence of transcriptional compensation in one ohnologue USP when the related USP is knocked out. These findings will have implications for potential targeted therapies.
Evolution of the hydrogen-bonded network in methanol-water mixtures upon cooling
Creators: name: Pethes, Ildikó
name: Pusztai, László
name: Temleitner, László
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The hydrogen-bonded structure of methanol-water mixtures is investigated over the entire alcohol concentration range (from $x_{\mathrm{Methanol}}=$ 0.1 to 1.0) at several temperatures, from 300 K down to the freezing point of the given mixture. Classical molecular dynamics simulations have been carried out, using the all-atom OPLS-AA force field for methanol and the TIP4P/2005 model for water molecules. Simulation trajectories ('particle configurations') obtained have been analyzed, in order to characterize the hydrogen-bonded network in the mixtures. The temperature and concentration dependence of the average hydrogen bond (H-bond) numbers between different types of molecules, the donor/acceptor roles of water and methanol molecules, and hydrogen bond number distributions have been revealed. The topology of the total system, as well as that of the water and methanol subsystems, has been investigated by calculating the cluster size distributions, the number of primitive rings, and ring size and ring type distributions. It has been found that upon cooling, the average number of H-bonded water molecules increases at every concentration and temperature investigated. As far as the connectivity of the hydrogen-bonded network is concerned, the percolation threshold has been shown to be above $x_{\mathrm{M}}=$ 0.9 already at room temperature.
description: 62 pages together with Supplementary Material, published in Journal of Molecular Liquids
Growing Graphs with Hyperedge Replacement Graph Grammars
Creators: name: Aguiñaga, Salvador
name: Palacios, Rodrigo
name: Chiang, David
name: Weninger, Tim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Discovering the underlying structures present in large real world graphs is a fundamental scientific problem. In this paper we show that a graph's clique tree can be used to extract a hyperedge replacement grammar. If we store an ordering from the extraction process, the extracted graph grammar is guaranteed to generate an isomorphic copy of the original graph. Or, a stochastic application of the graph grammar rules can be used to quickly create random graphs. In experiments on large real world networks, we show that random graphs, generated from extracted graph grammars, exhibit a wide range of properties that are very similar to the original graphs. In addition to graph properties like degree or eigenvector centrality, what a graph "looks like" ultimately depends on small details in local graph substructures that are difficult to define at a global level. We show that our generative graph model is able to preserve these local substructures when generating new graphs and performs well on new and difficult tests of model robustness.
description: 18 pages, 19 figures, accepted to CIKM 2016 in Indianapolis, IN
Motivations and benefits of formal volunteering
Creators: name: Polidano., Cain
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Asymmetry and tighter uncertainty relations for Rényi entropies via quantum-classical decompositions of resource measures
Creators: name: Hall, Michael J. W.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: It is known that the variance and entropy of quantum observables decompose into intrinsically quantum and classical contributions. Here a general method of constructing quantum-classical decompositions of resources such as uncertainty is discussed, with the quantum contribution specified by a measure of the noncommutativity of a given set of operators relative to the quantum state, and the classical contribution generated by the mixedness of the state. Suitable measures of noncommutativity or 'quantumness' include quantum Fisher information, and the asymmetry of a given set, group or algebra of operators, and are generalised to nonprojective observables and quantum channels. Strong entropic uncertainty relations and lower bounds for Rényi entropies are obtained, valid for arbitrary discrete observables, that take the mixedness of the state into account via a classical contribution to the lower bound. These relations can also be interpreted without reference to quantum-classical decompositions, as tradeoff relations that bound the asymmetry of one observable in terms of the entropy of another.
description: v1: 12+3 pages, 0 figures, 1 bazinga! v2: comparison with classical lower bound for Renyi entropy added (including 1 Figure), plus minor corrections/clarifications
Calibration of photomultiplier tubes
Creators: name: Kalousis, L. N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The purpose of the present article is to demonstrate the calibration of photomultipliers with a gaussian single photoelectron response using a numerical method based on the Discrete Fourier Transform (DFT). Conventional techniques, commonly employed in the literature, use approximate models or brute force numerical calculations of the convolution integrals that lead to the charge response function of the photomultiplier, $S_R(x)$. In this publication, we explain how a truncated gaussian model for the single photoelectron amplification can lead to rigorous results if one leans on the DFT approach. The distinct feature of this procedure is that $S_R(x)$ is calculated to all orders in the Poisson mean $μ$ that characterizes the light intensity and no approximations are needed. This scheme was applied to the calibration of the Hamamatsu R7081 photomultiplier tube and a comparison of the DFT approach with the more standard numerical integration method is also presented. Last, toy Monte Carlo data were analyzed for different values of $μ$ to understand the precision of the DFT method.
Cycle Detection in Computation Tree Logic
Creators: name: Fontaine, Gaëlle
name: Mogavero, Fabio
name: Murano, Aniello
name: Perelli, Giuseppe
name: Sorrentino, Loredana
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic in Computer Science (cs.LO)
subject: Formal Languages and Automata Theory (cs.FL)
subject: FOS: Computer and information sciences
subject: F.1.1, F.4.4, F.4.3

description: Temporal logic is a very powerful formalism deeply investigated and used in formal system design and verification. Its application usually reduces to solving specific decision problems such as model checking and satisfiability. In these kind of problems, the solution often requires detecting some specific properties over cycles. For instance, this happens when using classic techniques based on automata, game-theory, SCC decomposition, and the like. Surprisingly, no temporal logics have been considered so far with the explicit ability of talking about cycles. In this paper we introduce Cycle-CTL*, an extension of the classical branching-time temporal logic CTL* along with cycle quantifications in order to predicate over cycles. This logic turns out to be very expressive. Indeed, we prove that it strictly extends CTL* and is orthogonal to mu-calculus. We also give an evidence of its usefulness by providing few examples involving non-regular properties. We investigate the model checking problem for Cycle-CTL* and show that it is PSPACE-Complete as for CTL*. We also study the satisfiability problem for the existential-cycle fragment of the logic and show that it is solvable in 2ExpTime. This result makes use of an automata-theoretic approach along with novel ad-hoc definitions of bisimulation and tree-like unwinding.
description: In Proceedings GandALF 2016, arXiv:1609.03648
Shortcut to adiabaticity in spinor condensates
Creators: name: Sala, Arnau
name: Núñez, David López
name: Martorell, Joan
name: De Sarlo, Luigi
name: Zibold, Tilman
name: Gerbier, Fabrice
name: Polls, Artur
name: Juliá-Díaz, Bruno
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We devise a method to shortcut the adiabatic evolution of a spin-1 Bose gas with an external magnetic field as the control parameter. An initial many-body state with almost all bosons populating the Zeeman sublevel $m=0$, is evolved to a final state very close to a macroscopic spin-singlet condensate, a fragmented state with three macroscopically occupied Zeeman states. The shortcut protocol, obtained by an approximate mapping to a harmonic oscillator Hamiltonian, is compared to linear and exponential variations of the control parameter. We find a dramatic speedup of the dynamics when using the shortcut protocol.
description: 10 pages, 7 figures
Influence of an amorphous wall on the distribution of localized excitations in a colloidal glass-forming liquid
Creators: name: Gokhale, Shreyas
name: Nagamanasa, K. Hima
name: Sood, A. K.
name: Ganapathy, Rajesh
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Elucidating the nature of the glass transition has been the holy grail of condensed matter physics and statistical mechanics for several decades. A phenomenological aspect that makes glass formation a conceptually formidable problem is that structural and dynamic correlations in glass-forming liquids are too subtle to be captured at the level of conventional two-point functions. As a consequence, a host of theoretical techniques, such as quenched amorphous configurations of particles, have been devised and employed in simulations and colloid experiments to gain insights into the mechanisms responsible for these elusive correlations. Very often, though, the analysis of spatio-temporal correlations is performed in the context of a single theoretical framework, and critical comparisons of microscopic predictions of competing theories are thereby lacking. Here, we address this issue by analysing the distribution of localized excitations, which are building blocks of relaxation as per the Dynamical Facilitation (DF) theory, in the presence of an amorphous wall, a construct motivated by the Random First-Order Transition theory (RFOT). We observe that spatial profiles of the concentration of excitations exhibit complex features such as non-monotonicity and oscillations. Moreover, the smoothly varying part of the concentration profile yields a length scale $ξ_c$, which we compare with a previously computed length scale $ξ_{dyn}$. Our results suggest a method to assess the role of dynamical facilitation in governing structural relaxation in glass-forming liquids.
description: 19 pages, 7 figures
TRIPS and the political economy of the rice value chain : a focus on small producers in North-Western India
Creators: name: Plahe., Jagjit Kaur
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Quantum quench dynamics in the Luttinger liquid phase of the Hatano-Nelson model
Creators: name: Dóra, Balázs
name: Werner, Miklós Antal
name: Moca, Cătălin Paşcu
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We investigate the quantum quench dynamics of the interacting Hatano-Nelson model with open boundary conditions using both abelian bosonization and numerical methods. Specifically, we follow the evolution of the particle density and current profile in real space over time by turning the imaginary vector potential on or off in the presence of weak interactions. Our results reveal spatio-temporal Friedel oscillations in the system with light cones propagating ballistically from the open ends, accompanied by local currents of equal magnitude for both switch off and on protocols. Remarkably, the bosonization method accurately accounts for the density and current patterns with a single overall fitting parameter. The continuity equation is satisfied by the long wavelength part of the density and current, despite the non-unitary time evolution when the Hatano-Nelson term is switched on.
description: 9 pages, 4 figures
Causality, Non-Locality and Negative Refraction
Creators: name: Forcella, Davide
name: Prada, Claire
name: Carminati, Rémi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The importance of spatial non-locality in the description of negative refraction in electromagnetic materials has been put forward recently. We develop a theory of negative refraction in homogeneous and isotropic media, based on first principles, and that includes non-locality in its full generality. The theory shows that both dissipation and spatial non-locality are necessary conditions for the existence of negative refraction. It also provides a sufficient condition in materials with weak spatial non-locality. These fundamental results should have broad implications in the theoretical and practical analyses of negative refraction of electromagnetic and other kinds of waves.
description: 8 pages, 3 figures
Black holes in a new gravitational theory with trace anomalies
Creators: name: Tsujikawa, Shinji
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In a new gravitational theory with the trace anomaly recently proposed by Gabadadze, we study the existence of hairy black hole solutions on a static and spherically symmetric background. In this theory, the effective 4-dimensional action contains a kinetic term of the conformal scalar field related to a new scale $bar{M}$ much below the Planck mass. This property can overcome a strong coupling problem known to be present in general relativity supplemented by the trace anomaly as well as in 4-dimensional Einstein-Gauss-Bonnet gravity. We find a new hairy black hole solution arising from the Gauss-Bonnet trace anomaly, which satisfies regular boundary conditions of the conformal scalar and metric on the horizon. Unlike unstable exact black hole solutions with a divergent derivative of the scalar on the horizon derived for some related theories in the literature, we show that our hairy black hole solution can be consistent with all the linear stability conditions of odd- and even-parity perturbations.
description: 14 pages, 1 figure
An inventory of existing tools to promote crop diversification: fifty tools and methods already available for farmers and advisors
Creators: name: VANDEWALLE Aline
name: CAPPE DE BAILLON, Paul
name: MEROT Emmanuel
Publisher: name: Zenodo
Year: 2020

description: Nowadays, farmers and advisors can access numerous tools and methods linked to crop diversification. Some of them express their difficulties to find the most adapted through this jungle. In DiverIMPACTS project, an inventory of existing tools and methods for crop diversification across Europe was conducted in 2018, aiming to identify and characterize them according to their purpose, type, users, and technical characteristics. This is the first step to build a decision tree to support farmers, advisors and other actors along the value chain, to identify the most suitable tool for their situation and needs. This inventory aims to give an overview of the existing tools and methods to promote crop diversification, including all its components (e.g., rotation, multiple cropping, inter-cropping) at the value chain and territory levels. The large scope of this inventory led to identify tools and/or methods created to support crop diversification (with one or more identified strategies), as well as those using crop diversification as a way to achieve an expected impact. The inventory was based on an online survey as well as interviews. 58 responses have been collected from 38 different people from 11 countries. The database contains 42 tools and eight methods from eight different countries. A tool/method often allows users to make several kinds of decisions (e.g., management, design, mobilization of references, diagnosis, assessment) and can mobilize different diversification mechanisms (e.g., rotation, multiple cropping, intercropping) or a combination of different levers. Most of the tools can be implemented at the field or cropping system scale (46/50). Only eight could be used at the territory or value chain level. Different kinds of information about how to mobilize these tools/methods have been registered such as format, language, when to use the tool, training requirements, cost of the tool and contact person or organization. The database describing all of the tools is available and will be incremented during the project with new tools. Eight tools under development (mainly from other H2020 projects) were also identified during the inventory process. They will be added to the database when they become available for end-users.
Second-Harmonic Scattering as a Probe of Structural Correlations in Liquids
Creators: name: Tocci, Gabriele
name: Liang, Chungwen
name: Wilkins, David M.
name: Roke, Sylvie
name: Ceriotti, Michele
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Second-harmonic scattering experiments of water and other bulk molecular liquids have long been assumed to be insensitive to interactions between the molecules. The measured intensity is generally thought to arise from incoherent scattering due to individual molecules. We introduce a method to compute the second-harmonic scattering pattern of molecular liquids directly from atomistic computer simulations, which takes into account the coherent terms. We apply this approach to large-scale molecular dynamics simulations of liquid water, where we show that nanosecond second-harmonic scattering experiments contain a coherent contribution arising from radial and angular correlations on a length scale of < 1 nm, much shorter than had been recently hypothesized (Shelton, D. P. J. Chem. Phys. 2014, 141). By combining structural correlations from simulations with experimental data (Shelton, D. P. J. Chem. Phys. 2014, 141), we can also extract an effective molecular hyperpolarizability in the liquid phase. This work demonstrates that second-harmonic scattering experiments and atomistic simulations can be used in synergy to investigate the structure of complex liquids, solutions, and biomembranes, including the intrinsic intermolecular correlations.
Perturbatively corrected ring-polymer instanton theory for accurate tunneling splittings
Creators: name: Lawrence, Joseph E.
name: Dusek, Jindrich
name: Richardson, Jeremy O.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We introduce an approach for calculating perturbative corrections to the ring-polymer instanton approximation to tunneling splittings (RPI+PC), by computing higher-order terms in the asymptotic expansion in $\hbar$. The resulting method goes beyond standard instanton theory by using information on the third and fourth derivatives of the potential along the tunneling path to include additional anharmonic effects. This leads to significant improvements both in systems with low barriers and in systems with anharmonic modes. We demonstrate the applicability of RPI+PC to molecular systems by computing the tunneling splitting in full-dimensional malonaldehyde and a deuterated derivative. Comparing to both experiment and recent quantum-mechanical benchmark results, we find that our perturbative correction reduces the error from -11% to 2% for hydrogen transfer and performs even better for the deuterated case. This makes our approach more accurate than previous calculations using diffusion Monte Carlo and path-integral molecular dynamics, while being more computationally efficient.
description: 18 pages, 4 figures
Path-Following Algorithms for Beamforming and Signal Splitting in RF Energy Harvesting Networks
Creators: name: Nasir, Ali A.
name: Tuan, Hoang D.
name: Ngo, Duy T.
name: Durrani, Salman
name: Kim, Dong In
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We consider the joint design of transmit beamforming and receive signal-splitting ratios in the downlink of a wireless network with simultaneous radio-frequency (RF) information and energy transfer. Under constraints on the signal-to-interference-plus-noise ratio (SINR) at each user and the total transmit power at the base station, the design objective is to maximize either the sum harvested energy or the minimum harvested energy. We develop a computationally efficient path-following method to solve these challenging nonconvex optimization problems. We mathematically show that the proposed algorithms iteratively progress and converge to locally optimal solutions. Simulation results further show that these locally optimal solutions are the same as the globally optimal solutions for the considered practical network settings.
description: accepted for publication in IEEE Communication Letters
Learning to Predict Navigational Patterns from Partial Observations
Creators: name: Karlsson, Robin
name: Carballo, Alexander
name: Lepe-Salazar, Francisco
name: Fujii, Keisuke
name: Ohtani, Kento
name: Takeda, Kazuya
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences
subject: I.2.10; I.2.9

description: Human beings cooperatively navigate rule-constrained environments by adhering to mutually known navigational patterns, which may be represented as directional pathways or road lanes. Inferring these navigational patterns from incompletely observed environments is required for intelligent mobile robots operating in unmapped locations. However, algorithmically defining these navigational patterns is nontrivial. This paper presents the first self-supervised learning (SSL) method for learning to infer navigational patterns in real-world environments from partial observations only. We explain how geometric data augmentation, predictive world modeling, and an information-theoretic regularizer enables our model to predict an unbiased local directional soft lane probability (DSLP) field in the limit of infinite data. We demonstrate how to infer global navigational patterns by fitting a maximum likelihood graph to the DSLP field. Experiments show that our SSL model outperforms two SOTA supervised lane graph prediction models on the nuScenes dataset. We propose our SSL method as a scalable and interpretable continual learning paradigm for navigation by perception. Code is available at https://github.com/robin-karlsson0/dslp.
description: Accepted to IEEE Robotics and Automation Letters (RA-L) 2023
Universe's memory and spontaneous coherence in loop quantum cosmology
Creators: name: Pawłowski, Tomasz
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The quantum bounce a priori connects several (semi)classical epochs of Universe evolution, however determining if and how well the semiclassicality is preserved in this transition is highly nontrivial. We review the present state of knowledge in that regards in the isotropic sector of loop quantum cosmology. This knowledge is next extended by studies of an isotropic universe admitting positive cosmological constant (featuring an infinite chain of large Universe epochs). It is also shown, that such universe always admits a semiclassical epoch thanks to spontaneous spontaneous coherence, provided it is semiclassical in certain constant of motion playing the role of energy.
description: RevTex4-1, 12 pages, contribution to special issue on loop quantum cosmology of IJMPD
Bounded-oscillation Pushdown Automata
Creators: name: Ganty, Pierre
name: Valput, Damir
Publisher: name: arXiv
Year: 2016
Subjects: subject: Formal Languages and Automata Theory (cs.FL)
subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences

description: We present an underapproximation for context-free languages by filtering out runs of the underlying pushdown automaton depending on how the stack height evolves over time. In particular, we assign to each run a number quantifying the oscillating behavior of the stack along the run. We study languages accepted by pushdown automata restricted to k-oscillating runs. We relate oscillation on pushdown automata with a counterpart restriction on context-free grammars. We also provide a way to filter all but the k-oscillating runs from a given PDA by annotating stack symbols with information about the oscillation. Finally, we study closure properties of the defined class of languages and the complexity of the k-emptiness problem asking, given a pushdown automaton P and k >= 0, whether P has a k-oscillating run. We show that, when k is not part of the input, the k-emptiness problem is NLOGSPACE-complete.
description: In Proceedings GandALF 2016, arXiv:1609.03648
Dynamic Optimization of Trajectory for Ramp-up Current Profile in Tokamak Plasmas
Creators: name: Ren, Zhigang
name: Xu, Chao
name: Ou, Yongsheng
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Optimization and Control (math.OC)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In this paper, we consider an open-loop, finite-time, optimal control problem of attaining a specific desired current profile during the ramp-up phase by finding the best open-loop actuator input trajectories. Average density, total power, and plasma current are used as control actuators to manipulate the profile shape in tokamak plasmas. Based on the control parameterization method, we propose a numerical solution procedure directly to solve the original PDE-constrained optimization problem using gradient-based optimization techniques such as sequential quadratic programming (SQP). This paper is aimed at proposing an effective framework for the solution of PDE-constrained optimization problem in tokamak plasmas. A more user-friendly and efficient graphical user interface (GUI) is designed in MATLAB and the numerical simulation results are verified to demonstrate its applicability. In addition, the proposed framework of combining existing PDE and numerical optimization solvers to solve PDE-constrained optimization problem has the prospective to target challenge advanced control problems arising in more general chemical engineering processes.
description: 19 pages, 13 figures
Linear analysis of the Kelvin-Helmholtz instability in relativistic magnetized symmetric flows
Creators: name: Chow, Anthony
name: Rowan, Michael E.
name: Sironi, Lorenzo
name: Davelaar, Jordy
name: Bodo, Gianluigi
name: Narayan, Ramesh
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We study the linear stability of a planar interface separating two fluids in relative motion, focusing on the symmetric configuration where the two fluids have the same properties (density, temperature, magnetic field strength, and direction). We consider the most general case with arbitrary sound speed $c_{\rm s}$, Alfvén speed $v_{\rm A}$, and magnetic field orientation. For the instability associated with the fast mode, we find that the lower bound of unstable shear velocities is set by the requirement that the projection of the velocity onto the fluid-frame wavevector is larger than the projection of the Alfvén speed onto the same direction, i.e., shear should overcome the effect of magnetic tension. In the frame where the two fluids move in opposite directions with equal speed $v$, the upper bound of unstable velocities corresponds to an effective relativistic Mach number $M_{re} \equiv v/v_{\rm f\perp} \sqrt{(1-v_{\rm f\perp}^2)/(1-v^2)} \cosθ=\sqrt{2}$, where $v_{rm f\perp}=[v_A^2+c_{\rm s}^2(1-v_A^2)]^{1/2}$ is the fast speed assuming a magnetic field perpendicular to the wavevector (here, all velocities are in units of the speed of light), and $θ$ is the laboratory-frame angle between the flow velocity and the wavevector projection onto the shear interface. Our results have implications for shear flows in the magnetospheres of neutron stars and black holes -- both for single objects and for merging binaries -- where the Alfvén speed may approach the speed of light.
description: 11 pages, 7 figures, 1 table, Accepted for publication in Monthly Notices of the Royal Astronomical Society
World coffee markets : economic theory and time series analysis
Creators: name: Olsen., Tine Skov
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Tracing evolutionary trajectories in the presence of gene flow in South American temperate lizards (Squamata: Liolaemus kingii group)
Creators: name: Sánchez, Kevin
name: Recknagel, Hans
name: Elmer, Kathryn Rebecca
name: Avila, Luciano J.
name: Morando, Mariana
Publisher: name: Zenodo
Year: 2024
Subjects: Phylogeography
Gene flow
Phyloclimatic modelling
phenotypic evolution

description: Evolutionary processes behind lineage divergence often involve multidimensional differentiation. However, in the context of recent divergences, the signals exhibited by each dimension may not converge. In such scenarios, incomplete lineage sorting, gene flow, and scarce phenotypic differentiation are pervasive. Here, we integrated genomic (RAD loci of 90 individuals), phenotypic (linear and geometric traits of 823 and 411 individuals, respectively), spatial, and climatic data to reconstruct the evolutionary history of a speciation continuum of liolaemid lizards (Liolaemus kingii group). Specifically, we (i) inferred the population structure of the group and contrasted it with the phenotypic variability; (ii) assessed the role of post-divergence gene flow in shaping phylogeographic and phenotypic patterns; and (iii) explored eco-geographic drivers of diversification across time and space. We inferred eight genomic clusters exhibiting leaky genetic borders coincident with geographic transitions. We also found evidence of post-divergence gene flow resulting in transgressive phenotypic evolution in one species. Predicted ancestral niches unveiled suitable areas in southern and eastern Patagonia during glacial and interglacial periods. Our study underscores integrating different data and model-based approaches to determine the underlying causes of diversification, a challenge faced in the study of recently diverged groups. We also highlight Liolaemus as a model system for phylogeographic and broader evolutionary studies.
description: Funding provided by: Consejo Nacional de Investigaciones Científicas y TécnicasCrossref Funder Registry ID: https://ror.org/03cqe8w59Award Number: PUE 0044-2016
Funding provided by: Consejo Nacional de Investigaciones Científicas y TécnicasCrossref Funder Registry ID: https://ror.org/03cqe8w59Award Number: PIP 6469/05
Funding provided by: Consejo Nacional de Investigaciones Científicas y TécnicasCrossref Funder Registry ID: https://ror.org/03cqe8w59Award Number: PEI 6397/01
Funding provided by: Consejo Nacional de Investigaciones Científicas y TécnicasCrossref Funder Registry ID: https://ror.org/03cqe8w59Award Number: PIP 0336/13
Funding provided by: Consejo Nacional de Investigaciones Científicas y TécnicasCrossref Funder Registry ID: https://ror.org/03cqe8w59Award Number: PIP 1631/21
Funding provided by: Consejo Nacional de Investigaciones Científicas y TécnicasCrossref Funder Registry ID: https://ror.org/03cqe8w59Award Number:
Optimal Scheduling in IoT-Driven Smart Isolated Microgrids Based on Deep Reinforcement Learning
Creators: name: Qi, Jiaju
name: Lei, Lei
name: Zheng, Kan
name: Yang, Simon X.
name: Xuemin
name: Shen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this paper, we investigate the scheduling issue of diesel generators (DGs) in an Internet of Things (IoT)-Driven isolated microgrid (MG) by deep reinforcement learning (DRL). The renewable energy is fully exploited under the uncertainty of renewable generation and load demand. The DRL agent learns an optimal policy from history renewable and load data of previous days, where the policy can generate real-time decisions based on observations of past renewable and load data of previous hours collected by connected sensors. The goal is to reduce operating cost on the premise of ensuring supply-demand balance. In specific, a novel finite-horizon partial observable Markov decision process (POMDP) model is conceived considering the spinning reserve. In order to overcome the challenge of discrete-continuous hybrid action space due to the binary DG switching decision and continuous energy dispatch (ED) decision, a DRL algorithm, namely the hybrid action finite-horizon RDPG (HAFH-RDPG), is proposed. HAFH-RDPG seamlessly integrates two classical DRL algorithms, i.e., deep Q-network (DQN) and recurrent deterministic policy gradient (RDPG), based on a finite-horizon dynamic programming (DP) framework. Extensive experiments are performed with real-world data in an IoT-driven MG to evaluate the capability of the proposed algorithm in handling the uncertainty due to inter-hour and inter-day power fluctuation and to compare its performance with those of the benchmark algorithms.
An Efficient Quadratic Interpolation Scheme for a Third-Order Cell-Centered Finite-Volume Method on Tetrahedral Grids
Creators: name: Nishikawa, Hiroaki
name: White, Jeffery A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we propose an efficient quadratic interpolation formula utilizing solution gradients computed and stored at nodes and demonstrate its application to a third-order cell-centered finite-volume discretization on tetrahedral grids. The proposed quadratic formula is constructed based on an efficient formula of computing a projected derivative. It is efficient in that it completely eliminates the need to compute and store second derivatives of solution variables or any other quantities, which are typically required in upgrading a second-order cell-centered unstructured-grid finite-volume discretization to third-order accuracy. Moreover, a high-order flux quadrature formula, as required for third-order accuracy, can also be simplified by utilizing the efficient projected-derivative formula, resulting in a numerical flux at a face centroid plus a curvature correction not involving second derivatives of the flux. Similarly, a source term can be integrated over a cell to high-order in the form of the source term evaluated at the cell centroid plus a curvature correction, again, not requiring second derivatives of the source term. The discretization is defined as an approximation to an integral form of a conservation law but the numerical solution is defined as a point value at a cell center, leading to another feature that there is no need to compute and store geometric moments for a quadratic polynomial to preserve a cell average. Third-order accuracy and improved second-order accuracy are demonstrated and investigated for simple but illustrative test cases in three dimensions.
Chiral phase transitions in the linear sigma model in the Tsallis nonextensive statistics
Creators: name: Ishihara, Masamichi
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We studied chiral phase transitions in the Tsallis nonextensive statistics which has two parameters, the temperature $T$ and entropic parameter $q$. The linear sigma model was used in this study. The critical temperature, condensate, masses, and energy density were calculated under the massless free particle approximation. The critical temperature decreases as $q$ increases. The condensate at $q>1$ is smaller than that at $q=1$. The sigma mass at $q>1$ is heavier than the mass at $q=1$ at high temperature, while the sigma mass at $q>1$ is lighter than the mass at $q=1$ at low temperature. The pion mass at $q>1$ is heavier than the mass at $q=1$. The energy density increases remarkably as $q$ increases. The $q$ dependence in the case of the $q$-expectation value is weaker than that in the case of the conventional expectation value with a Tsallis distribution. The parameter $q$ should be smaller than $4/3$ from energetic point of view. The validity of the Tsallis statistics can be determined by the difference in $q$ of the restriction for $5/4 < q < 4/3$ when the interaction is weak, because the parameter $q$ is smaller than $5/4$ in the case of the conventional expectation value with a Tsallis distribution.
description: 10 pages, 6 figures
iMet: A computational tool for structural annotation of unknown metabolites from tandem mass spectra
Creators: name: Aguilar-Mogas, Antoni
name: Sales-Pardo, Marta
name: Navarro, Miriam
name: Tautenhahn, Ralf
name: Guimerà, Roger
name: Yanes, Oscar
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences
subject: 92-08

description: Untargeted metabolomic studies are revealing large numbers of naturally occurring metabolites that cannot be characterized because their chemical structures and MS/MS spectra are not available in databases. Here we present iMet, a computational tool based on experimental tandem mass spectrometry that could potentially allow the annotation of metabolites not discovered previously. iMet uses MS/MS spectra to identify metabolites structurally similar to an unknown metabolite, and gives a net atomic addition or removal that converts the known metabolite into the unknown one. We validate the algorithm with 148 metabolites, and show that for 89% of them at least one of the top four matches identified by iMet enables the proper annotation of the unknown metabolite. iMet is freely available at http://imet.seeslab.net.
description: 21 pages, 6 figures
On Quantified Propositional Logics and the Exponential Time Hierarchy
Creators: name: Hannula, Miika
name: Kontinen, Juha
name: Lück, Martin
name: Virtema, Jonni
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: F.1.3; F.4.1

description: We study quantified propositional logics from the complexity theoretic point of view. First we introduce alternating dependency quantified boolean formulae (ADQBF) which generalize both quantified and dependency quantified boolean formulae. We show that the truth evaluation for ADQBF is AEXPTIME(poly)-complete. We also identify fragments for which the problem is complete for the levels of the exponential hierarchy. Second we study propositional team-based logics. We show that DQBF formulae correspond naturally to quantified propositional dependence logic and present a general NEXPTIME upper bound for quantified propositional logic with a large class of generalized dependence atoms. Moreover we show AEXPTIME(poly)-completeness for extensions of propositional team logic with generalized dependence atoms.
description: In Proceedings GandALF 2016, arXiv:1609.03648
Guidebook on co-creation and reflexive policy making Synthesis of the UPLIFT WP4 Results
Creators: name: Hoekstra, Joris
name: Gentili, Martina
Publisher: name: Zenodo
Year: 2023
Subjects: policy co-creation
Reflexive Policy Making
policy innovation
Reflexive Policy Agenda

description: This Guidebook is the final deliverable of the work package 4 (WP4) of the UPLIFT project. The overall aim of this work package was to explore how young people’s voices can be put at the centre of youth policy. In order to do this, we carried out four parallel policy co-creation processes with young people in four different locations across Europe, each with a different focus – education, housing and NEET youth. The process took the best part of three years and involved several institutional stakeholders, as well as dozens of young people. This deliverable is a comprehensive outlook of the WP4 work in all four locations – Tallin, Sfântu Gheorghe, Barakaldo and Amsterdam.
Emission from quantum-dot high- microcavities: transition from spontaneous emission to lasing and the effects of superradiant emitter coupling
Creators: name: Kreinberg, S.
name: Chow, W. W.
name: Wolters, J.
name: Schneider, C.
name: Gies, C.
name: Jahnke, F.
name: Höfling, S.
name: Kamp, M.
name: Reitzenstein, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Measured and calculated results are presented on the emission properties of a new class of emitters operating in the cavity quantum electrodynamics regime. The structures are based on high-finesse GaAs/AlAs micropillar cavities, each with an active medium consisting of a layer of InGaAs quantum dots and distinguishing feature of having substantial fraction of spontaneous emission channeled into one cavity mode (high-beta factor). This paper shows that the usual criterion for lasing with a conventional (low-beta factor) cavity, a sharp nonlinearity in an input-output curve accompanied by noticeable linewidth narrowing, has to be reinforced by the equal-time second-order photon autocorrelation function for confirming lasing. It will also show that the equal-time second-order photon autocorrelation function is useful for recognizing superradiance, a manifestation of the correlations possible in high- microcavities operating with quantum dots. In terms of consolidating the collected data and identifying the physics underlying laser action, both theory and experiment suggest a sole dependence on intracavity photon number. Evidence for this comes from all our measured and calculated data on emission coherence and fluctuation, for devices ranging from LEDs and cavity-enhanced LEDs to lasers, lying on the same two curves: one for linewidth narrowing versus intracavity photon number and the other for g(2)(0) versus intracavity photon number.