cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Thermodynamics of a two-dimensional frustrated spin-1/2 Heisenberg ferromagnet
Creators: name: Härtel, M.
name: Richter, J.
name: Ihle, D.
name: Drechsler, S. -L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Using the spin-rotation-invariant Green's function method we calculate the thermodynamic quantities (correlation functions , uniform static spin susceptibility χ, correlation length ξ, and specific heat C_V) of the two-dimensional spin-1/2 J1-J2 Heisenberg ferromagnet for J2 < J2^c \approx 0.44|J1|, where J2^c is the critical frustrating antiferromagnetic next-nearest neighbor coupling at which the ferromagnetic ground state gives way for a ground-state phase with zero magnetization. Examining the low-temperature behavior of χand ξ, in the limit T \to 0 both quantities diverge exponentially, i.e., χ\propto \exp(b/T) and ξ\propto\exp(b/2T), respectively. We find a linear decrease of the coefficient b with increasing frustration according to b=-(π/2)(J1+2J2), i.e., the exponential divergence of χand ξis present up to J2^c. Furthermore, we find an additional low-temperature maximum in the specific heat when approaching the critical point, J2 \to J2^c.
description: 7 pages, 6 figures, version as published in PRB
Evaluation of Non-Negative Matrix Factorization and n-stage Latent Dirichlet Allocation for Emotion Analysis in Turkish Tweets
Creators: name: Guven, Zekeriya Anil
name: Diri, Banu
name: Cakaloglu, Tolgahan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences
subject: H.3.3; I.2.7; I.7.0

description: With the development of technology, the use of social media has become quite common. Analyzing comments on social media in areas such as media and advertising plays an important role today. For this reason, new and traditional natural language processing methods are used to detect the emotion of these shares. In this paper, the Latent Dirichlet Allocation, namely LDA, and Non-Negative Matrix Factorization methods in topic modeling were used to determine which emotion the Turkish tweets posted via Twitter. In addition, the accuracy of a proposed n-level method based on LDA was analyzed. Dataset consists of 5 emotions, namely angry, fear, happy, sad and confused. NMF was the most successful method among all topic modeling methods in this study. Then, the F1-measure of Random Forest, Naive Bayes and Support Vector Machine methods was analyzed by obtaining a file suitable for Weka by using the word weights and class labels of the topics. Among the Weka results, the most successful method was n-stage LDA, and the most successful algorithm was Random Forest.
description: Published in: 2019 Innovations in Intelligent Systems and Applications Conference (ASYU). This paper is extension version of Comparison Method for Emotion Detection of Twitter Users (http://dx.doi.org/10.1109/ASYU48272.2019.8946435). Please citation this IEEE paper
The closure of ideals of $\boldsymbol{\ell^1(Σ)}$ in its enveloping $\boldsymbol{\mathrm{C}^\ast}$-algebra
Creators: name: de Jeu, Marcel
name: Tomiyama, Jun
Publisher: name: arXiv
Year: 2017
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46K99 (Primary), 46H10, 47L65, 54H20 (Secondary)

description: If $X$ is a compact Hausdorff space and $σ$ is a homeomorphism of $X$, then an involutive Banach algebra $\ell^1(Σ)$ of crossed product type is naturally associated with the topological dynamical system $Σ=(X,σ)$. We initiate the study of the relation between two-sided ideals of $\ell^1(Σ)$ and ${\mathrm C}^\ast(Σ)$, the enveloping $\mathrm{C}^\ast$-algebra ${\mathrm C}(X)\rtimes_σ\mathbb Z$ of $\ell^1(Σ)$. Among others, we prove that the closure of a proper two-sided ideal of $\ell^1(Σ)$ in ${\mathrm C}^\ast(Σ)$ is again a proper two-sided ideal of ${\mathrm C}^\ast(Σ)$.
description: 9 pages. Minor changes in presentation from the original. Final version; to appear in Adv. Oper. Theory
title: GSICS quarterly. Volume 6, number 1 (2012)
Creators: name: Global Space-Based Inter-Calibration System Coordination Center,
Publisher: name: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service, Center for Satellite Applications and Research
Year: 2012
Subjects: subject: Satellite meteorology
subject: Global Observing System (Meteorology)

description: GSICS Quarterly is a newsletter designed to communicate GSICS activities to all GSICS members and partners, as well as to satellite data users and policy makers
The structure of doubly non-commuting isometries
Creators: name: de Jeu, Marcel
name: Pinto, Paulo R.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47A45, 47A20

description: Suppose that $n\geq 1$ and that, for all $i$ and $j$ with $1\leq i,j\leq n$ and $i\neq j$, $z_{ij}\in{\mathbb T}$ are given such that $z_{ji}=\overline{z}_{ij}$ for all $i\neq j$. If $V_1,\dotsc, V_n$ are isometries on a Hilbert space such that $V_i^\ast V_j^{\phantom{\ast}}\!=\overline{z}_{ij} V_j^{\phantom{\ast}}\!V_i^\ast$ for all $i\neq j$, then $(V_1,\dotsc,V_n)$ is called an $n$-tuple of doubly non-commuting isometries. The generators of non-commutative tori are well-known examples. In this paper, we establish a simultaneous Wold decomposition for $(V_1,\dotsc,V_n)$. This decomposition enables us to classify such $n$-tuples up to unitary equivalence. We show that the joint listing of a unitary equivalence class of a representation of each of the $2^n$ non-commutative tori that are naturally associated with the structure constants is a classifying invariant. A dilation theorem is also established, showing that an $n$-tuple of doubly non-commuting isometries can be extended to an $n$-tuple of doubly non-commuting unitary operators on an enveloping Hilbert space.
description: A remark on the relation between the dilation theorem in this paper and other dilation theorems for multiple operators in the literature has been added. Otherwise, there are only a few minor editorial changes compared to the first version; some typos have also been corrected. Final version, to appear in Advances in Mathematics
A construction for coisotropic subalgebras of Lie bialgebras
Creators: name: Zambon, Marco
Publisher: name: arXiv
Year: 2008
Subjects: subject: Symplectic Geometry (math.SG)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 17B62, 53D17

description: Given a Lie bialgebra (g,g*), we present an explicit procedure to construct coisotropic subalgebras, i.e. Lie subalgebras of g whose annihilator is a Lie subalgebra of g*. We write down families of examples for the case that g is a classical complex simple Lie algebra.
description: 12 pages. New, shorter proof for Prop. 2.3. New Remark 4.1. Some material moved to appendix. Final version
Lattice homomorphisms in harmonic analysis
Creators: name: Dales, H. Garth
name: de Jeu, Marcel
Publisher: name: arXiv
Year: 2018
Subjects: subject: Functional Analysis (math.FA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 43A99 (Primary), 28C05, 06F25, 43A10, 43A15, 43A20 (Secondary)

description: Let $S$ be a non-empty, closed subspace of a locally compact group $G$ that is a subsemigroup of $G$. Suppose that $X, Y$, and $Z$ are Banach lattices that are vector sublattices of the order dual $\mathrm{C}_{\mathrm{c}}(S,\mathbb R)^\sim$ of the real-valued, continuous functions with compact support on $S$, and where $Z$ is Dedekind complete. Suppose that $\ast: X\times Y\to Z$ is a positive bilinear map such that $\mathrm{supp}\,{(x \ast y)}\subseteq\mathrm{supp}\,{x}\,\cdot\,\mathrm{supp}\,{y}$ for all $x\in X^+$ and $y\in Y^+$ with compact support. We show that, under mild conditions, the canonically associated map from $X$ into the vector lattice of regular operators from $Y$ into $Z$ is then a lattice homomorphism. Applications of this result are given in the context of convolutions, answering questions previously posed in the literature. As a preparation, we show that the order dual of the continuous, compactly supported functions on a closed subspace of a locally compact space can be canonically viewed as an order ideal of the order dual of the continuous, compactly supported functions on the larger space. As another preparation, we show that $\mathrm{L}^p$-spaces and Banach lattices of measures on a locally compact space can be embedded as vector sublattices of the order dual of the continuous, compactly supported functions on that space.
description: 43 pages. Minor corrections; mathematically identical to the first version. Final version, to appear in `Positivity and noncommutative analysis. Festschrift in honour of Ben de Pagter on the occasion of his 65th birthday' (Birkhauser, 2019; edited by Gerard Buskes, Marcel de Jeu, Peter Dodds, Anton Schep, Fedor Sukochev, Jan van Neerven, and Anthony Wickstead)
A large-scale one-way quantum computer in an array of coupled cavities
Creators: name: Lin, G. W.
name: Zou, X. B.
name: Lin, X. M.
name: Guo, G. C.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose an efficient method to realize a large-scale one-way quantum computer in a two-dimensional (2D) array of coupled cavities, based on coherent displacements of an arbitrary state of cavity fields in a closed phase space. Due to the nontrivial geometric phase shifts accumulating only between the qubits in nearest-neighbor cavities, a large-scale 2D cluster state can be created within a short time. We discuss the feasibility of our method for scale solid-state quantum computation
description: 5 pages, 3 figures
Biological effects of bioactive components and extracts derived from edible plants commonly used in human nutrition
Creators: name: Danesi, Francesca <1977>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: BIO/10 Biochimica

description: The main aim of this PhD research project was the evaluation of the biological effects of bioactive compounds derived from edible plants, with particular attention on their possibility to counteract oxidative damage and inflammation. 
After a preliminary study of in vitro antioxidant activity, regarding the modification eventually occurring after home freezing and cooking of edible vegetables, cultured mammalian cells were used as experimental model systems. 
Soluble extract and essential oils derived from different cultivars of Brassicaceae and Lamiaceae were tested as possible tools for the counteraction of the oxidative damage due to reactive oxygen species (ROS), underlining differences related to cultivar and agronomic techniques.
Since accumulating evidence indicates that phytochemicals exhibit several additional properties in complex biological systems, a nutrigenomic approach was used to further explain the biological activity of a green tea extract, and to evidence the anti-inflammatory role of bioactive compounds derived from different foods.
Overall, results obtained could contribute to a better understanding of the potential health benefit of plant foods.
Lithography in the schools
Creators: name: Wilson, Robert
Publisher: name: University of British Columbia
Year: 2010

description: Lithography is a print medium which allows the artist almost complete freedom in terms of image development. It is the fastest growing art medium on the North American Continent. However, until now, this important print medium has virtually been ignored in the high schools. The reasons for the omission in the high school art programs are financial and technical. The traditional methods of establishing a lithography workshop requires a vast amount of money, usually much more than the average art department's budget could afford. The technical difficulties involved not only in setting up the workshop but also in the processing and printing of the lithographs seemed to have finished any furthur discussion of establishing facilities at the high school level. Drawing upon fourteen years acquaintance with lithography, the experience of setting up a lithographic workshop on a small budget and experience as a high school art teacher I am attempting in this thesis to provide alternate methods for establishing a lithographic program in the schools. The teacher, although he may be lacking in any technical knowledge of lithography, should be able to follow the instructions set down in the thesis and be able to start a litho program with his classes. Included in the thesis are instruction whereby the teacher can start his classes using almost soley the existing facilities found in most art rooms or he can, if budget allows, develope a full facility including all aspects of lithography. All the equipment has been built by the writer and all the procedures have been tested. I am sure that by diligently following the instructions any art teacher could provide an interesting and rewarding lithographic program for his students.
Core-corona effect in hadron collisions and muon production in air showers
Creators: name: Baur, Sebastian
name: Dembinski, Hans
name: Perlin, Matias
name: Pierog, Tanguy
name: Ulrich, Ralf
name: Werner, Klaus
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is very well known that the fraction of energy in a hadron collision going into electromagnetic particles (electrons and photons, including those from decays) has a large impact on the number of muons produced in air shower cascades. Recent measurements at the LHC confirm features that can be linked to a mixture of different underlying particle production mechanisms such as a collective statistical hadronization (core) in addition to the expected string fragmentation (corona). Since the two mechanisms have a different electromagnetic energy fraction, we present a possible connection between statistical hadronization in hadron collisions and muon production in air showers. Using a novel approach, we demonstrate that the core-corona effect as observed at the LHC could be part of the solution for the lack of muon production in simulations of high energy cosmic rays. To probe this hypothesis, we study hadronization in high energy hadron collisions using calorimetric information over a large range of pseudorapidity in combination with the multiplicity of central tracks. As an experimental observable, we propose the production of energy in electromagnetic particles versus hadrons, as a function of pseudorapidity and central charged particle multiplicity.
A hypothetical upper bound for the solutions of a Diophantine equation with a finite number of solutions
Creators: name: Tyszka, Apoloniusz
Publisher: name: arXiv
Year: 2009
Subjects: subject: Number Theory (math.NT)
subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03D20, 11U05

description: We conjecture that if a system S \subseteq {x_i=1, x_i+x_j=x_k, x_i \cdot x_j=x_k: i,j,k \in {1,...,n}} has only finitely many solutions in integers x_1,...,x_n, then each such solution (x_1,...,x_n) satisfies |x_1|,...,|x_n| \leq 2^{2^{n-1}}. By the conjecture, if a Diophantine equation has only finitely many solutions in integers (non-negative integers, rationals), then their heights are bounded from above by a computable function of the degree and the coefficients of the equation. The conjecture implies that the set of Diophantine equations which have infinitely many solutions in integers (non-negative integers) is recursively enumerable. The conjecture stated for an arbitrary computable bound instead of 2^{2^{n-1}} remains in contradiction to Matiyasevich's conjecture that each recursively enumerable set M \subseteq {\mathbb N}^n has a finite-fold Diophantine representation.
description: Unchanged text, the conjecture with the bound 2^(2^(n-1)) is false, see http://dx.doi.org/10.13140/2.1.1707.2640 arXiv admin note: substantial text overlap with arXiv:1105.5747, arXiv:1102.4122, arXiv:1011.4103, arXiv:1109.3826
Evolution of Saturn's north polar color and cloud structure between 2012 and 2017 inferred from Cassini VIMS and ISS observations
Creators: name: Sromovsky, L. A.
name: Baines, K. H.
name: Fry, P. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Cassini/ISS imagery and Cassini/VIMS spectral imaging observations from 0.35 to 5.12 microns show that between 2012 and 2017 the region poleward of the Saturn's northern hexagon changed from dark blue/green to a moderately brighter gold color, except for the inner eye region (88.2 deg - 90 deg N), which remained relatively unchanged. These and even more dramatic near-IR changes can be reproduced by an aerosol model of four compact layers consisting of a stratospheric haze at an effective pressure near 50 mbar, a deeper haze of putative diphosphine particles typically near 300 mbar, an ammonia cloud layer with a base pressure between 0.4 bar and 1.3 bar, and a deeper cloud of a possible mix of NH4SH and water ice particles within the 2.7 to 4.5 bar region. Our analysis of the background clouds between the discrete features shows that between 2013 and 2016 the effective pressures of most layers changed very little, except for the ammonia ice layer, which decreased from about 1 bar to 0.4 bar near the edge of the eye, but increased to 1 bar inside the eye. Inside the hexagon there were large increases in optical depth, by up to a factor of 10 near the eye for the putative diphosphine layer and by a factor of four over most of the hexagon interior. Inside the eye, aerosol optical depths were very low, suggesting downwelling motions. The high contrast between eye and surroundings in 2016 was due to substantial increases in optical depths outside the eye. The color change from blue/green to gold inside most of the hexagon region can be explained in our model almost entirely by changes in the stratospheric haze, which increased between 2013 and 2016 by a factor of four in optical depth and by almost a factor of three in the short-wavelength peak imaginary index.
description: 47 pages, 38 figures, 7 tables
Triplon current generation in solids
Creators: name: Chen, Yao
name: Sato, Masahiro
name: Tang, Yifei
name: Shiomi, Yuki
name: Oyanagi, Koichi
name: Masuda, Takatsugu
name: Nambu, Yusuke
name: Fujita, Masaki
name: Saitoh, Eiji
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A triplon refers to a fictitious particle that carries angular momentum $S = 1$ corresponding to the elementary excitation in a broad class of quantum dimerized spin systems. Such systems without magnetic order have long been studied as a testing ground for quantum properties of spins. Although triplons have been found to play a central role in thermal and magnetic properties in dimerized magnets with singlet correlation, a spin angular momentum flow carried by triplons, a triplon current, has not been detected yet. Here we report spin Seebeck effects induced by a triplon current: triplon spin Seebeck effect, using a spin-Peierls system CuGeO$_3$. The result shows that the heating-driven triplon transport induces spin current whose sign is positive, opposite to the spin-wave cases in magnets. The triplon spin Seebeck effect persists far below the spin-Peierls transition temperature, being consistent with a theoretical calculation for triplon spin Seebeck effects.
Assessment of applied microwave power of intermittent microwave-dried carrot powders from Colour and NIRS
Creators: name: Keskin, M.
name: Soysal, Y.
name: Sekerli, Y.E.
name: Arslan, A.
name: Celiktas, N.
Publisher: name: Agronomy Research
Year: 2019
Subjects: Microwave drying
applied power
carrot
reflectance
chromameter
FT-NIRS
article

description: Applied microwave (MW) power level is an essential factor on the quality of the dried agricultural products. Even if higher MW powers result in shorter drying times, they lead to quality degradations. It is almost impossible to know the applied MW power of a dried and powdered product by human vision. Thus, the aim of this study was to predict the applied MW power of carrot powders by using two different instruments, a chromameter and FT-NIRS. The experiments were carried out at nine different power levels (100–500 W) with three replications (N = 27). The colour and NIR reflectance was measured using a chromameter and NIRS system. The data was analysed using PLS regression. The drying time of intermittent MW drying at the highest applied power of 500 W was 1.12–5.47 times shorter than those of other lower applied powers. Applied MW power was a crucial factor on all colour parameters of the powdered carrots. Brightness (L*) decreased significantly with the increase of applied MW power resulting in darker product colours. Data analysis results showed that the NIRS system (R2 = 0.99; SEP = 16.1 W) can predict the microwave power of powdered carrots with significantly better performance than a chromameter (R2 = 0.95; SEP = 29.9 W). But, the chromamater is far more inexpensive when compared with the NIRS system and hence, it can also be used to predict the applied MW power from the colour data relatively well. Also, a mathematical model was developed to predict applied MW power from the colour parameters.
The Generalized Injectivity Conjecture
Creators: name: Dijols, Sarah
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: We prove a conjecture of Casselman and Shahidi stating that the unique irreducible generic subquotient of a standard module is necessarily a subrepresentation for a large class of connected quasi-split reductive groups, in particular for those which have a root system of classical type (or product of such groups). To do so, we prove and use the existence of strategic embeddings for irreducible generic discrete series representations, extending some results of Moeglin.
description: accepted for publication at Bulletin de la SMF, slightly shortened version (67p)
title: Journal Bildende Kunst.Gestaltung.Musik.Bühne.Wissen
Creators: name: Universität Der Künste Berlin
Publisher: name: Verlag der Universität der Künste
Year: 2021

description: Ausgabe 14 (2021 Herbst)
description: Journal Bildende Kunst.Gestaltung.Musik.Bühne.Wissen; 2021, Herbst
On the zero-temperature limit of Gibbs states
Creators: name: Chazottes, J. -R.
name: Hochman, M.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mathematical Physics (math-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We exhibit Lipschitz (and hence Hölder) potentials on the full shift $\{0,1\}^{\mathbb{N}}$ such that the associated Gibbs measures fail to converge as the temperature goes to zero. Thus there are "exponentially decaying" interactions on the configuration space $\{0,1\}^{\mathbb Z}$ for which the zero-temperature limit of the associated Gibbs measures does not exist. In higher dimension, namely on the configuration space $\{0,1\}^{\mathbb{Z}^{d}}$, $d\geq3$, we show that this non-convergence behavior can occur for finite-range interactions, that is, for locally constant potentials.
description: The statement of Theorem 1.2 is more accurate and some new comment follow it
Classification of simple modules with finite-dimensional weight spaces for the N = 2 Ramond algebra
Creators: name: Liu, Dong
name: Pei, Yufeng
name: Xia, Limeng
Publisher: name: arXiv
Year: 2019
Subjects: subject: Representation Theory (math.RT)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 17B10, 17B65, 17B68, 17B70

description: In this paper, we classify all simple weight modules with finite-dimensional weight spaces over the $N=2$ Ramond algebra. Any such module $V$ is either a simple highest weight module or a simple lowest weight module, or a simple cuspidal module with ${\rm b}(V)\le 2$.
description: 15 pages, the published manuscript is its Chinese version, the methods in Section 4 are original
On the minimax optimality and superiority of deep neural network learning over sparse parameter spaces
Creators: name: Hayakawa, Satoshi
name: Suzuki, Taiji
Publisher: name: arXiv
Year: 2019
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 62G08

description: Deep learning has been applied to various tasks in the field of machine learning and has shown superiority to other common procedures such as kernel methods. To provide a better theoretical understanding of the reasons for its success, we discuss the performance of deep learning and other methods on a nonparametric regression problem with a Gaussian noise. Whereas existing theoretical studies of deep learning have been based mainly on mathematical theories of well-known function classes such as Hölder and Besov classes, we focus on function classes with discontinuity and sparsity, which are those naturally assumed in practice. To highlight the effectiveness of deep learning, we compare deep learning with a class of linear estimators representative of a class of shallow estimators. It is shown that the minimax risk of a linear estimator on the convex hull of a target function class does not differ from that of the original target function class. This results in the suboptimality of linear methods over a simple but non-convex function class, on which deep learning can attain nearly the minimax-optimal rate. In addition to this extreme case, we consider function classes with sparse wavelet coefficients. On these function classes, deep learning also attains the minimax rate up to log factors of the sample size, and linear methods are still suboptimal if the assumed sparsity is strong. We also point out that the parameter sharing of deep neural networks can remarkably reduce the complexity of the model in our setting.
description: 33 pages
On Designing Compliant Actuators Based On Dielectric Elastomers
Creators: name: Berselli, Giovanni <1978>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: ING-IND/13 Meccanica applicata alle macchine

description: Dielectric Elastomers (DE) are incompressible dielectrics which can experience deviatoric (isochoric) finite deformations in response to applied large electric fields. Thanks to the strong electro-mechanical coupling, DE intrinsically offer great potentialities for conceiving novel solid-state mechatronic devices, in particular linear actuators, which are more integrated, lightweight, economic, silent, resilient and disposable than equivalent devices based on traditional technologies. Such systems may have a huge impact in applications where the traditional technology does not allow coping with the limits of weight or encumbrance, and with problems involving interaction with humans or unknown environments. Fields such as medicine, domotic, entertainment, aerospace and transportation may profit.
For actuation usage, DE are typically shaped in thin films coated with compliant electrodes on both sides and piled one on the other to form a multilayered DE. DE-based Linear Actuators (DELA) are entirely constituted by polymeric materials and their overall performance is highly influenced by several interacting factors; firstly by the electromechanical properties of the film, secondly by the mechanical properties and geometry of the polymeric frame designed to support the film, and finally by the driving circuits and activation strategies.
In the last decade, much effort has been focused in the devolvement of analytical and numerical models that could explain and predict the hyperelastic behavior of different types of DE materials. Nevertheless, at present, the use of DELA is limited. The main reasons are 1) the lack of quantitative and qualitative models of the actuator as a whole system 2) the lack of a simple and reliable design methodology.
In this thesis, a new point of view in the study of DELA is presented which takes into account the interaction between the DE film and the film supporting frame. Hyperelastic models of the DE film are reported which are capable of modeling the DE and the compliant electrodes. The supporting frames are analyzed and designed as compliant mechanisms using pseudo-rigid body models and subsequent finite element analysis.
A new design methodology is reported which optimize the actuator performances allowing to specifically choose its inherent stiffness. As a particular case, the methodology focuses on the design of constant force actuators. This class of actuators are an example of how the force control could be highly simplified. Three new DE actuator concepts are proposed which highlight the goodness of the proposed method.
The impact of R&D in firm value across Europe
L'impatto della ricerca e sviluppo sul valore delle imprese in Europa
Creators: name: Duqi, Andi <1980>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2012
Subjects: SECS-P/11 Economia degli intermediari finanziari

description: In this thesis the impact of R&D expenditures on firm market value and stock returns is examined. This is performed in a sample of European listed firms for the period 2000-2009. I apply different linear and GMM econometric estimations for testing the impact of R&D on market prices and construct country portfolios based on firms’ R&D expenditure to market capitalization ratio for studying the effect of R&D on stock returns. The results confirm that more innovative firms have a better market valuation,investors consider R&D as an asset that produces long-term benefits for corporations. The impact of R&D on firm value differs across countries. It is significantly modulated by the financial and legal environment where firms operate. Other firm and industry characteristics seem to play a determinant role when investors value R&D. First, only larger firms with lower financial leverage that operate in highly innovative sectors decide to disclose their R&D investment. Second, the markets assign a premium to small firms, which operate in hi-tech sectors compared to larger enterprises for low-tech industries.
On the other hand, I provide empirical evidence indicating that generally highly R&D-intensive firms may enhance mispricing problems related to firm valuation. As R&D
contributes to the estimation of future stock returns, portfolios that comprise high R&D-intensive stocks may earn significant excess returns compared to the less innovative after controlling for size and book-to-market risk. Further, the most innovative firms are generally more risky in terms of stock volatility but not systematically more risky than low-tech firms. Firms that operate in Continental Europe suffer more mispricing compared
to Anglo-Saxon peers but the former are less volatile, other things being equal. The sectors where firms operate are determinant even for the impact of R&D on stock returns; this effect is much stronger in hi-tech industries.
Correlation-Based Device Energy-Efficient Dynamic Multi-Task Offloading for Mobile Edge Computing
Creators: name: Zhang, Siqi
name: Yi, Na
name: Ma, Yi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Task offloading to mobile edge computing (MEC) has emerged as a key technology to alleviate the computation workloads of mobile devices and decrease service latency for the computation-intensive applications. Device battery consumption is one of the limiting factors needs to be considered during task offloading. In this paper, multi-task offloading strategies have been investigated to improve device energy efficiency. Correlations among tasks in time domain as well as task domain are proposed to be employed to reduce the number of tasks to be transmitted to MEC. Furthermore, a binary decision tree based algorithm is investigated to jointly optimize the mobile device clock frequency, transmission power, structure and number of tasks to be transmitted. MATLAB based simulation is employed to demonstrate the performance of our proposed algorithm. It is observed that the proposed dynamic multi-task offloading strategies can reduce the total energy consumption at device along various transmit power versus noise power point compared with the conventional one.
description: 5 pages
Convergence analysis of approximation formulas for analytic functions via duality for potential energy minimization
Creators: name: Hayakawa, Satoshi
name: Tanaka, Ken'ichiro
Publisher: name: arXiv
Year: 2019
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We investigate the approximation formulas that were proposed by Tanaka & Sugihara (2019), in weighted Hardy spaces, which are analytic function spaces with certain asymptotic decay. Under the criterion of minimum worst error of $n$-point approximation formulas, we demonstrate that the formulas are nearly optimal. We also obtain the upper bounds of the approximation errors that coincide with the existing heuristic bounds in asymptotic order by duality theorem for the minimization problem of potential energy.
description: 17 pages
Gravitoelectromagnetism and stellar orbits in galaxies
Creators: name: Toth, Viktor T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Beyond the Newtonian approximation, gravitational fields in general relativity can be described using a formalism known as gravitoelectromagnetism. In this formalism a vector potential, the gravitomagnetic potential, arises as a result of moving masses, in strong analogy with the magnetic force due to moving charges in Maxwell's theory. Gravitomagnetism can affect orbits in the gravitational field of a massive, rotating body. This raises the possibility that gravitomagnetism may serve as the dominant physics behind the anomalous rotation curves of spiral galaxies, eliminating the need for dark matter. In this essay, we methodically work out the magnitude of the gravitomagnetic equivalent of the Lorentz force and apply the result to the Milky Way. We find that the resulting contribution is too small to produce an observable effect on these orbits. We also investigate the impact of cosmological boundary conditions on the result and find that these, too, are negligible.
description: 5 pages, no figures (accepted for publication in Int. J. Mod. Phys. D)
Development of the Double Cascade Reconstruction Techniques in the Baikal-GVD Neutrino Telescope
Creators: name: Allakhverdyan, V. A.
name: Avrorin, A. D.
name: Avrorin, A. V.
name: Aynutdinov, V. M.
name: Bannasch, R.
name: Bardačová, Z.
name: Belolaptikov, I. A.
name: Borina, I. V.
name: Brudanin, V. B.
name: Budnev, N. M.
name: Dik, V. Y.
name: Domogatsky, G. V.
name: Doroshenko, A. A.
name: Dvornický, R.
name: Dyachok, A. N.
name: Dzhilkibaev, Zh. -A. M.
name: Eckerová, E.
name: Elzhov, T. V.
name: Fajt, L.
name: Fialkovski, S. V.
name: Gafarov, A. R.
name: Golubkov, K. V.
name: Gorshkov, N. S.
name: Gress, T. I.
name: Katulin, M. S.
name: Kebkal, K. G.
name: Kebkal, O. G.
name: Khramov, E. V.
name: Kolbin, M. M.
name: Konischev, K. V.
name: Kopański, K. A.
name: Korobchenko, A. V.
name: Koshechkin, A. P.
name: Kozhin, V. A.
name: Kruglov, M. V.
name: Kryukov, M. K.
name: Kulepov, V. F.
name: Malecki, Pa.
name: Malyshkin, Y. M.
name: Milenin, M. B.
name: Mirgazov, R. R.
name: Naumov, D. V.
name: Nazari, V.
name: Noga, W.
name: Petukhov, D. P.
name: Pliskovsky, E. N.
name: Rozanov, M. I.
name: Rushay, V. D.
name: Ryabov, E. V.
name: Safronov, G. B.
name: Shaybonov, B. A.
name: Shelepov, M. D.
name: Šimkovic, F.
name: Sirenko, A. E.
name: Skurikhin, A. V.
name: Solovjev, A. G.
name: Sorokovikov, M. N.
name: Štekl, I.
name: Stromakov, A. P.
name: Sushenok, E. O.
name: Suvorova, O. V.
name: Tabolenko, V. A.
name: Tarashansky, B. A.
name: Yablokova, Y. V.
name: Yakovlev, S. A.
name: Zaborov, D. N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The Baikal-GVD is a neutrino telescope under construction in Lake Baikal. The main goal of the Baikal-GVD is to observe neutrinos via detecting the Cherenkov radiation of the secondary charged particles originating in the interactions of neutrinos. In 2021, the installation works concluded with 2304 optical modules installed in the lake resulting in effective volume approximately 0.4 km$^{3}$. In this paper, the first steps in the development of double cascade reconstruction techniques are presented.
description: Presented at the 37th International Cosmic Ray Conference (ICRC 2021)
Genetic analysis of tumour initiation and progression in a Drosophila model of epithelial cancer
Creators: name: Froldi, Francesca <1984>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2012
Subjects: MED/04 Patologia generale

description: Neoplastic overgrowth depends on the cooperation of several mutations ultimately leading to major rearrangements in cellular behaviour. The molecular crosstalk occurring between precancerous and normal cells strongly influences the early steps of the tumourigenic process as well as later stages of the disease.  Precancerous cells are often removed by cell death from normal tissues but the mechanisms responsible for such fundamental safeguard processes remain in part elusive. To gain insight into these phenomena I took advantage of the clonal analysis methods available in Drosophila for studying the phenotypes due to loss of function of the neoplastic tumour suppressor lethal giant larvae (lgl). I found that lgl mutant cells growing in wild-type imaginal wing discs are subject to the phenomenon of cell competition and are eliminated by JNK-dependent cell death because they express very low levels of dMyc oncoprotein compared to those in the surrounding tissue. Indeed, in non-competitive backgrounds lgl mutant clones are able to overgrow and upregulate dMyc, overwhelming the neighbouring tissue and forming tumourous masses that display several cancer hallmarks.  These phenotypes are completely abolished by reducing dMyc abundance within mutant cells while increasing it in lgl clones growing in a competitive context re-establishes their tumourigenic potential.
Similarly,  the neoplastic growth observed upon the oncogenic cooperation between lgl mutation and activated Ras/Raf/MAPK signalling was found to be characterised by and dependent on the ability of cancerous cells to upregulate dMyc with respect to the adjacent normal tissue, through both transcriptional and post-transcriptional mechanisms, thereby confirming its key role in lgl-induced tumourigenesis. These results provide first evidence that the dMyc oncoprotein is required in lgl mutant tissue to promote invasive overgrowth in developing and adult epithelial tissues and that  dMyc abundance inside versus outside lgl mutant clones plays a key role in driving neoplastic overgrowth.
The Cook-Reckhow definition
Creators: name: Krajicek, Jan
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computational Complexity (cs.CC)
subject: Logic (math.LO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: The Cook-Reckhow 1979 paper defined the area of research we now call Proof Complexity. There were earlier papers which contributed to the subject as we understand it today, the most significant being Tseitin's 1968 paper, but none of them introduced general notions that would allow to make an explicit and universal link between lengths-of-proofs problems and computational complexity theory. In this note we shall highlight three particular definitions from the paper: of proof systems, p-simulations and the pigeonhole principle formula, and discuss their role in defining the field. We will also mention some related developments and open problems.
Improved hydrodynamic pulsation models for the pulsating extreme helium star V652 Herculis
Creators: name: Jeffery, C. Simon
name: Montañés-Rodríguez, Pilar
name: Saio, Hideyuki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: New non-linear hydrodynamic models have been constructed to simulate the radial pulsations observed in the extreme helium star V652 Her. These use a finer zoning to allow higher radial resolution than in previous simulations. Models incorporate updated OPAL and OP opacity tables and adopt a composition based on the best atmospheric analyses to date. Key pulsation properties including period, velocity amplitude and shock acceleration are examined as a function of the mean stellar parameters (mass, luminosity, and effective temperature). The new models confirm that, for large amplitude pulsations, a strong shock develops at minimum radius, and is associated with a large phase delay between maximum brightness and minimum radius. Using the observed pulsation period to constrain parameter space in one dimension, other pulsation properties are used to constrain the model space further, and to critically discuss observational measurements. Similar models may be useful for the interpretation of other blue large amplitude pulsators, which may also exhibit pulsation-driven shocks.
description: 19 pages, 14 figures, MNRAS in press
Role of Notch signalling in human hepatocellular carcinoma
Creators: name: Minguzzi, Manuela <1982>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2012
Subjects: BIO/11 Biologia molecolare

description: The Notch signalling is a cellular pathway that results conserved from Drosophila to Homo sapiens controlling a wide range of cellular processes in development and in differentiated organs. It induces cell proliferation or differentiation, increased survival or apoptosis, and it is involved in stemness maintainance. These functions are conserved, but exerted with a high tissue and cellular context specificity. Signalling activation determs nuclear translocation of the receptor’s cytoplasmic domain and activation of target genes transcription. As many developmental pathway, Notch deregulation is involved in cancer, leading to oncogenic or tumour suppressive role depending on the functions exerted in normal tissue. Notch1 and Notch3 resulted aberrantly expressed in human hepatocellular carcinoma (HCC) that is the more frequent tumour of the liver and the sixth most common tumour worldwide. This thesis has the aim to investigate the role of the signalling in HCC, with particular attention to dissect common and uncommon regulatory pathways between Notch1 and Notch3 and to define the role of the signalling in HCC. Nocth1 and Notch3 were analysed on their regulation on Hes1 target and involvement in cell cycle control. They showed to regulate  CDKN1C/p57kip2 expression through Hes1 target. CDKN1C/p57kip2 induces not only cell cycle arrest, but also senescence in HCC cell lines. Moreover, the involvement of Notch1 in cancer progression and epithelial to mesenchymal transition was investigated. Notch1 showed to induce invasion of HCC, regulating EMT and E- Cadherin expression. Moreover, Notch3 showed specific regulation on p53 at post translational levels.   In vitro and ex vivo analysis on HCC samples suggests a complex role of both receptors in regulate HCC, with an oncogenic role but also showing tumour suppressive effects, suggesting a complex and deep involvement of this signalling in HCC.
Canonical Equivariant Cohomology Classes Generating Zeta Values of Totally Real Fields
Creators: name: Bannai, Kenichi
name: Hagihara, Kei
name: Yamada, Kazuki
name: Yamamoto, Shuji
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11M35 (Primary), 11R42, 14L15, 55N91 (Secondary)

description: It is known that the special values at nonpositive integers of a Dirichlet $L$-function may be expressed using the generalized Bernoulli numbers, which are defined by a canonical generating function. The purpose of this article is to consider the generalization of this classical result to the case of Hecke $L$-functions of totally real fields. Hecke $L$-functions may be expressed canonically as a finite sum of zeta functions of Lerch type. By combining the non-canonical multivariable generating functions constructed by Shintani, we newly construct a canonical class, which we call the Shintani generating class, in the equivariant cohomology of an algebraic torus associated to the totally real field. Our main result states that the specializations at torsion points of the derivatives of the Shintani generating class give values at nonpositive integers of the zeta functions of Lerch type. This result gives the insight that the correct framework in the higher dimensional case is to consider higher equivariant cohomology classes instead of functions.
description: 18 pages, Updated version with minor corrections