cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Mediation and the indirect metafiction of Randolph Stow, M. K. Joseph, and Timothy Findley
Creators: name: Ingham, David Keith
Publisher: name: University of British Columbia
Year: 2010

description: In order to explore the range of indirect metafiction as presented in three exemplary novels, this dissertation begins by examining how the assumptions of "realism" on the one hand and "postmodernism" on the other relate to the paradigmatic triad of story-teller, story, and audience. From this context emerges the view that the range of metafiction is determined by how it reveals the processes and nature of fiction according to a spectrum of mediation: that of the writer between his "raw materials" and the text, that of the text between writer and reader, and that of the reader between the text and his interpretation. Indirect metafiction (or "pretend realism") mediates between realism and postmodernism, revealing without breaking the illusions of realism. Each of the next three chapters, after initially placing the key novel within the context of the author's work as a whole, discusses in detail a novel whose metafictional focus is on one of the three mediations. Accordingly, Chapter II focusses on Randolph Stow's The Girl Green as Elderflower (1980) and on the way it reveals the mediation of the author by presenting a writer's fiction as a synthesis of his personal and literary experiences. Chapter III notes how M. K. Joseph's A Soldier's Tale (1976) reflects the mediation of the reader by depicting a writer's interpretation and literary redaction of an oral tale. And Chapter IV shows how Timothy Findley's Famous Last Words (1981) demonstrates the mediation of the text by presenting a writer whose text "crystallizes" the illusions of fiction, then undercuts and exposes them. The analyses of the key texts employ both postmodern and traditional critical approaches, demonstrating them to be complementary; by noting the interpenetration of metafictional and traditional import and significance, the analyses also highlight the mediary nature of indirect metafiction. The fifth chapter draws theoretical conclusions from ideas in the practical chapters: from metafictional revelations through the paradigm of mediation comes an "anatomy" of fiction, delineating its elements; from a sense of how the mind "structures" experience through "fictional" representations of both "reality" and fictional texts comes a "physiology," a sense of how fiction works through language. This discussion leads to definitions of realistic, unrealistic, and self-conscious fiction, and of metafiction, both direct and indirect; the dissertation concludes by remarking on the inter-relations of language, "fiction," and "reality."
title: On Beyond-Birthday-Bound Security: Revisiting the Development of ISO/IEC 9797-1 MACs
Creators: name: Shen, Yaobin
name: Wang, Lei
Publisher: name: Ruhr-Universität Bochum
Year: 2019

description: ISO/IEC 9797-1 is an international standard for block-cipher-based Message Authentication Code (MAC). The current version ISO/IEC 9797-1:2011 specifies six single-pass CBC-like MAC structures that are capped at the birthday bound security. For a higher security that is beyond-birthday bound, it recommends to use the concatenation combiner of two single-pass MACs. In this paper, we reveal the invalidity of the suggestion, by presenting a birthday bound forgery attack on the concatenation combiner, which is essentially based on Joux’s multi-collision. Notably, our new forgery attack for the concatenation of two MAC Algorithm 1 with padding scheme 2 only requires 3 queries. Moreover, we look for patches by revisiting the development of ISO/IEC 9797-1 with respect to the beyond-birthday bound security. More specifically, we evaluate the XOR combiner of single-pass CBC-like MACs, which was used in previous version of ISO/IEC 9797-1.
description: IACR Transactions on Symmetric Cryptology, Volume 2019, Issue 2
title: Classification of Balanced Quadratic Functions
Creators: name: De Meyer, Lauren
name: Bilgin, Begül
Publisher: name: Ruhr-Universität Bochum
Year: 2019

description: S-boxes, typically the only nonlinear part of a block cipher, are the heart of symmetric cryptographic primitives. They significantly impact the cryptographic strength and the implementation characteristics of an algorithm. Due to their simplicity, quadratic vectorial Boolean functions are preferred when efficient implementations for a variety of applications are of concern. Many characteristics of a function stay invariant under affine equivalence. So far, all 6-bit Boolean functions, 3- and 4-bit permutations have been classified up to affine equivalence. At FSE 2017, Bozoliv et al. presented the first classification of 5-bit quadratic permutations. In this work, we propose an adaptation of their work resulting in a highly efficient algorithm to classify n x m functions for n ≥ m. Our algorithm enables for the first time a complete classification of 6-bit quadratic permutations as well as all balanced quadratic functions for n ≤ 6. These functions can be valuable for new cryptographic algorithm designs with efficient multi-party computation or side-channel analysis resistance as goal. In addition, we provide a second tool for finding decompositions of length two. We demonstrate its use by decomposing existing higher degree S-boxes and constructing new S-boxes with good cryptographic and implementation properties.
description: IACR Transactions on Symmetric Cryptology, Volume 2019, Issue 2
Multi-orbital model reveals second-order topological insulator in 1H-transition metal dichalcogenide
Creators: name: Zeng, Jiang
name: Liu, Haiwen
name: Jiang, Hua
name: Sun, Qing-Feng
name: Xie, X. C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Recently, a new class of second-order topological insulators (SOTIs) characterized by an electronic dipole has been theoretically introduced and proposed to host topological corner states. As a novel topological state, it has been attracting great interest and experimentally realized in artificial systems of various fields of physics based on multi-sublattice models, e.g., breathing kagome lattice. In order to realize such kind of SOTI in natural materials, we proposed a symmetry-faithful multi-orbital model. Then, we reveal several familiar transition metal dichalcogenide (TMD) monolayers as a material family of two-dimensional SOTI with large bulk gaps. The topologically protected corner state with fractional charge is pinned at Fermi level due to the charge neutrality and filling anomaly. Additionally, we propose that the zero-energy corner state preserves in the heterostructure composed of a topological nontrivial flake embedded in a trivial material. The novel second-order corner states in familiar TMD materials hold promise for revealing unexpected quantum properties and applications.
Turbulence energetics in stably stratified geophysical flows: strong and weak mixing regimes
Creators: name: Zilitinkevich, S. S.
name: Elperin, T.
name: Kleeorin, N.
name: Rogachevskii, I.
name: Esau, I.
name: Mauritsen, T.
name: Miles, M. W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Chaotic Dynamics (nlin.CD)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Traditionally, turbulence energetics is characterized by turbulent kinetic energy (TKE) and modelled using solely the TKE budget equation. In stable stratification, TKE is generated by the velocity shear and expended through viscous dissipation and work against buoyancy forces. The effect of stratification is characterized by the ratio of the buoyancy gradient to squared shear, called Richardson number, Ri. It is widely believed that at Ri exceeding a critical value, Ric, local shear cannot maintain turbulence, and the flow becomes laminar. We revise this concept by extending the energy analysis to turbulent potential and total energies (TPE and TTE = TKE + TPE), consider their budget equations, and conclude that TTE is a conservative parameter maintained by shear in any stratification. Hence there is no "energetics Ric", in contrast to the hydrodynamic-instability threshold, Ric-instability, whose typical values vary from 0.25 to 1. We demonstrate that this interval, 0.25>1, clarify principal difference between turbulent boundary layers and free flows, and provide basis for improving operational turbulence closure models.
description: 23 pages, 4 figures, Quarterly Journal of Royal Meteorological Society, in press
An OFDM-CDMA scheme for high data rate UWB applications
Creators: name: Guéguen, Emeric
name: Crussière, Matthieu
name: Hélard, Jean-François
Publisher: name: arXiv
Year: 2007
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: In this paper, we investigate a new waveform for UWB systems obtained by the combination of Orthogonal Frequency Division Multiplex (OFDM) and Code Division Multiple Access (CDMA). The proposed system, called Spread Spectrum - Multi-Carrier - Multiple Access (SS-MC-MA) turns out to be a judicious solution to combat frequency selectivity and narrowband interferers, and to manage the coexistence of several users and piconets. It is shown that the addition of a degree of freedom brought by the spreading component of SS-MC-MA allows to optimize jointly the assignment of the number of used codes and coding rates in order to make the system more robust. Through simulations, it is demonstrated that the new system can outperform Multi-Band OFDM Alliance (MBOA) for low data rates and is able to provide wider range of rates.
On chains in $H$-closed topological pospaces
Creators: name: Gutik, Oleg V.
name: Pagon, Dušan
name: Repovš, Dušan
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Topology (math.GN)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 54F05; 54H12; 06B30; 06F30; 22A26

description: We study chains in an $H$-closed topological partially ordered space. We give sufficient conditions for a maximal chain $L$ in an $H$-closed topological partially ordered space such that $L$ contains a maximal (minimal) element. Also we give sufficient conditions for a linearly ordered topological partially ordered space to be $H$-closed. We prove that any $H$-closed topological semilattice contains a zero. We show that a linearly ordered $H$-closed topological semilattice is an $H$-closed topological pospace and show that in the general case this is not true. We construct an example an $H$-closed topological pospace with a non-$H$-closed maximal chain and give sufficient conditions that a maximal chain of an $H$-closed topological pospace is an $H$-closed topological pospace.
description: We have rewritten and substantially expanded the manuscript
Approaching the thermodynamic limit in equilibrated scale-free networks
Creators: name: Waclaw, B.
name: Bogacz, L.
name: Janke, W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We discuss how various models of scale-free complex networks approach their limiting properties when the size N of the network grows. We focus mainly on equilibrated networks and their finite-size degree distributions. Our results show that subleading corrections to the scaling of the position of the cutoff are strong even for networks of order 10^9 nodes. We observe also a logarithmic correction to the scaling for degenerated graphs when the degree distribution follows a power law k^(-3). We study also the distribution of the maximal degree and show that it may have a different scaling than the cutoff and, moreover, it approaches the thermodynamic limit much faster. We present also some results on the cutoff function and the distribution of the maximal degree in equilibrated networks.
description: 9 pages, 5 figures, minor changes, figures replaced
Bayesian reconstruction of the cosmological large-scale structure: methodology, inverse algorithms and numerical optimization
Creators: name: Kitaura, F. S.
name: Ensslin, T. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We address the inverse problem of cosmic large-scale structure reconstruction from a Bayesian perspective. For a linear data model, a number of known and novel reconstruction schemes, which differ in terms of the underlying signal prior, data likelihood, and numerical inverse extra-regularization schemes are derived and classified. The Bayesian methodology presented in this paper tries to unify and extend the following methods: Wiener-filtering, Tikhonov regularization, Ridge regression, Maximum Entropy, and inverse regularization techniques. The inverse techniques considered here are the asymptotic regularization, the Jacobi, Steepest Descent, Newton-Raphson, Landweber-Fridman, and both linear and non-linear Krylov methods based on Fletcher-Reeves, Polak-Ribiere, and Hestenes-Stiefel Conjugate Gradients. The structures of the up-to-date highest-performing algorithms are presented, based on an operator scheme, which permits one to exploit the power of fast Fourier transforms. Using such an implementation of the generalized Wiener-filter in the novel ARGO-software package, the different numerical schemes are benchmarked with 1-, 2-, and 3-dimensional problems including structured white and Poissonian noise, data windowing and blurring effects. A novel numerical Krylov scheme is shown to be superior in terms of performance and fidelity. These fast inverse methods ultimately will enable the application of sampling techniques to explore complex joint posterior distributions. We outline how the space of the dark-matter density field, the peculiar velocity field, and the power spectrum can jointly be investigated by a Gibbs-sampling process. Such a method can be applied for the redshift distortions correction of the observed galaxies and for time-reversal reconstructions of the initial density field.
description: 40 pages, 11 figures
Proposed experiment for testing quantum contextuality with neutrons
Creators: name: Cabello, Adan
name: Filipp, Stefan
name: Rauch, Helmut
name: Hasegawa, Yuji
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show that an experimental demonstration of quantum contextuality using 2 degrees of freedom of single neutrons based on a violation of an inequality derived from the Peres-Mermin proof of the Kochen-Specker theorem would be more conclusive than those obtained from previous experiments involving pairs of ions [M. A. Rowe et al., Nature (London) 409, 791 (2001)] and single neutron [Y. Hasegawa et al., Nature (London) 425, 45 (2003)] based on violations of Clauser-Horne-Shimony-Holt-like inequalities.
description: REVTeX4, 4 pages, 1 figure
title: ZOCB and ZOTR: Tweakable Blockcipher Modes for Authenticated Encryption with Full Absorption
Creators: name: Bao, Zhenzhen
name: Guo, Jian
name: Iwata, Tetsu
name: Minematsu, Kazuhiko
Publisher: name: Ruhr-Universität Bochum
Year: 2019

description: We define ZOCB and ZOTR for nonce-based authenticated encryption with associated data, and analyze their provable security. These schemes use a tweakable blockcipher (TBC) as the underlying primitive, and fully utilize its input to process a plaintext and associated data (AD). This property is commonly referred to as full absorption, and this has been explored for schemes based on a permutation or a pseudorandom function (PRF). Our schemes improve the efficiency of TBC-based counterparts of OCB and OTR called OCB3 (Krovetz and Rogaway, FSE 2011) and OTR (Minematsu, EUROCRYPT 2014). Specifically, ΘCB3 and OTR have an independent part to process AD, and our schemes integrate this process into the encryption part of a plaintext by using the tweak input of the TBC. Up to a certain length of AD, ZOCB and ZOTR completely eliminate the independent process for it. Even for longer AD, our schemes process it efficiently by fully using the tweak input of the TBC. For this purpose, based on previous tweak extension schemes for TBCs, we introduce a scheme called XTX*. To our knowledge, ZOCB and ZOTR are the first efficiency improvement of ΘCB3 and OTR in terms of the number of TBC calls. Compared to Sponge-based and PRF-based schemes, ZOCB and ZOTR allow fully parallel computation of the underlying primitive, and have a unique design feature that an authentication tag is independent of a part of AD. We present experimental results illustrating the practical efficiency gain and clarifying the efficiency cost for it with a concrete instantiation. The results show that for long input data, our schemes have gains, while we have efficiency loss for short input data.
description: IACR Transactions on Symmetric Cryptology, Volume 2019, Issue 2
Altruism and politics
Creators: name: MacDermid, Robert Hugh
Publisher: name: University of British Columbia
Year: 2010

description: The growth of state authority in the societies of modern liberal democracies has resulted in a diminished scope for the exercise of individual obligations, duties and rights in private life. The decreasing sphere of individual authority may be partly explained by liberal theorists', and particularly John Locke's contention that individuals cannot provide without the coercion of the state, those public goods such as justice which distinguish the state of nature from civil society. For while man can be benevolent in private life, in public life he cannot be trusted to see beyond his own self-interest. Therefore, Locke and others concluded that public goods, which are produced by many and consumed by all, must be provided by the state. The thesis argues that benevolence or altruism is a theoretically possible if not prevalent motivation in public life. The spread of state authority manifest in the welfare state, reduces the opportunities and atrophies the willingness of individuals to behave altruistically. Moreover, different kinds of situations impose constraints upon the choice of an altruistic course of action. In a formal analysis of simple variable sum noncooperative games of the 2 x 2 order, altruism is shown to be a choice alternative in only a minority of games. But where altruism is not constrained, it is a demonstrable pressure on subjects' choices in two experiments. The subjects in the two experiments were required to choose between the two alternatives of a 2 x 2 game where decision pressures were defined over the payoff values of the matrix. The decision pressures represented in the games were benevolence, Pareto optimality, collective rationality, competition, and individual gains maximization. While the pressures of individual maximization and competition were revealed as the strongest by a multiple regression analysis, benevolence was shown to have a surprisingly strong influence upon the subjects' decisions. The finding supports the contention that individuals may be capable even in highly competitive albeit abstract situations, of sufficient benevolence to provide some of the public goods now supplied by the state. The findings therefore lend weight to the classical liberal argument for a reduced if not minimal state.
Ion-Photonic Frequency Qubit Correlations for Quantum Networks
Creators: name: Connell, Steven C.
name: Scarabel, Jordan
name: Bridge, Elizabeth M.
name: Shimizu, Kenji
name: Blums, Valdis
name: Ghadimi, Mojtaba
name: Lobino, Mirko
name: Streed, Erik W.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Efficiently scaling quantum networks to long ranges requires local processing nodes to perform basic computation and communication tasks. Trapped ions have demonstrated all the properties required for the construction of such a node, storing quantum information for up to 12 minutes, implementing deterministic high fidelity logic operations on one and two qubits, and ion-photon coupling. While most ions suitable for quantum computing emit photons in visible to near ultraviolet (UV) frequency ranges poorly suited to long-distance fibre optical based networking, recent experiments in frequency conversion provide a technological solution by shifting the photons to frequencies in the telecom band with lower attenuation for fused silica fibres. Encoding qubits in frequency rather than polarization makes them more robust against decoherence from thermal or mechanical noise due to the conservation of energy. To date, ion-photonic frequency qubit entanglement has not been directly shown. Here we demonstrate a frequency encoding ion-photon entanglement protocol in $^{171}$Yb$^+$ with correlations equivalent to 92.4(8)% fidelity using a purpose-built UV hyperfine spectrometer. The same robustness against decoherence precludes our passive optical setup from rotating photonic qubits to unconditionally demonstrate entanglement, however it is sufficient to allow us to benchmark the quality of ion-UV photon correlations prior to frequency conversion to the telecom band.
description: 11 pages. 5 figures, 31 references, submitted to New Journal of Physics
title: Quantum Security Analysis of AES
Creators: name: Bonnetain, Xavier
name: Naya-Plasencia, María
name: Schrottenloher, André
Publisher: name: Ruhr-Universität Bochum
Year: 2019

description: In this paper we analyze for the first time the post-quantum security of AES. AES is the most popular and widely used block cipher, established as the encryption standard by the NIST in 2001. We consider the secret key setting and, in particular, AES-256, the recommended primitive and one of the few existing ones that aims at providing a post-quantum security of 128 bits. In order to determine the new security margin, i.e., the lowest number of non-attacked rounds in time less than 2128 encryptions, we first provide generalized and quantized versions of the best known cryptanalysis on reduced-round AES, as well as a discussion on attacks that don’t seem to benefit from a significant quantum speed-up.
We propose a new framework for structured search that encompasses both the classical and quantum attacks we present, and allows to efficiently compute their complexity. We believe this framework will be useful for future analysis.
Our best attack is a quantum Demirci-Selçuk meet-in-the-middle attack. Unexpectedly, using the ideas underlying its design principle also enables us to obtain new, counter-intuitive classical TMD trade-offs. In particular, we can reduce the memory in some attacks against AES-256 and AES-128.
One of the building blocks of our attacks is solving efficiently the AES S-Box differential equation, with respect to the quantum cost of a reversible S-Box. We believe that this generic quantum tool will be useful for future quantum differential attacks. Judging by the results obtained so far, AES seems a resistant primitive in the post-quantum world as well as in the classical one, with a bigger security margin with respect to quantum generic attacks.
description: IACR Transactions on Symmetric Cryptology, Volume 2019, Issue 2
Legge del valore, legge dello scambio e problema della trasformazione: una nota
Creators: name: Gozzi, Giancarlo
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2014
Subjects: SECS-P/01 Economia politica

description: Marx’s analysis of the determination of the general rate of profit and of the associated relative prices is based on the conceptual distinction between law of value and law of
exchange. The law of value states that simple, necessary abstract labour is the substance and measure of the value of commodities and is fundamental in the analysis of the social relations of the capitalist economy, i.e. for the analysis of the creation of surplus-value; it therefore represents the theoretical framework within which the problem of the distribution of surplus-value among the different capitals may be approached, i.e. the law of
exchange must be taken into consideration.
The analytical mistakes surrounding the marxian solution of the problem have given the way to the critics of the labour theory of value to question its relevance and coherence
as a tool for the analysis of the capitalist mode of production. The aim of the present note is simply to show that it is possible to frame the relationship between law of value and law of exchange along marxian lines while determining in a coherent way the rate of profit and
the corresponding relative prices of commodities in such a way that the proportionality between profits and surplus-labour is retained. Actually this is the main result of the “New Interpretation” of the marxian transformation problem which is obtained by defining the conservation of value in terms of the net product and not the gross one and the value of labour power in terms of generalized (or unallocated) purchasing power. This interpretation of the problem is therefore in contrast with the neoricardian one which is based on the refutation of the role of the law of value different from that of the determination of the relative prices of the commodities.
The cluster glass state in the two-dimensional extended t-J model
Creators: name: Chou, Chung-Pin
name: Fukushima, Noboru
name: Lee, Ting Kuo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The recent observation of an electronic cluster glass state composed of random domains with unidirectional modulation of charge density and/or spin density on Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} reinvigorates the debate of existence of competing interactions and their importance in high temperature superconductivity. By using a variational approach, here we show that the presence of the cluster glass state is actually an inherent nature of the model based on the antiferromagnetic interaction (J) only, i.e. the well known t-J model. There is no need yet to introduce a competing interaction to understand the existence of the cluster glass state. The long-range pairing correlation is not much influenced by the disorder in the glass state which also has nodes and linear density of states. In the antinodal region, the spectral weight is almost completely suppressed. The modulation also produces subgap structures inside the "coherent" peaks of the local density of states.
description: 9 pages, 5 figures, submitted to PRB
New New Realism. Su Ipermodernità di Raffaele Donnarumma
Creators: name: Baldi, Valentino
Publisher: name: Università degli Studi di Cagliari
Year: 2014

description: Nel 2010 Einaudi ha proposto al pubblico un progetto editoriale presentato con ampi sforzi di marketing ed intitolato Atlante della letteratura italiana. L’opera, in tre volumi, era suddivisa secondo periodi e movimenti storico-culturali affermati da secoli (Medioevo, Rinascimento, Illuminismo), ma al suo interno si strutturava per aree geografiche rilevanti, fondendo così storia, storiografia e topografia (L’età di Avignone, L’età di Trento, L’età di Venezia, ecc.). I curatori, Sergio Luzzatto e Gabriele Pedullà, firmarono una densa Introduzione in cui, dopo aver rimarcato l’originalità del progetto, si interrogavano sul senso della storiografia letteraria negli anni Zero.
description: Between, Vol 4, N° 8 (2014): Tecnologia, immaginazione e forme del narrare
Combination of OFDM and CDMA for high data rate UWB
Creators: name: Guéguen, Emeric
name: Madaoui, Nadia
name: Hélard, Jean-François
name: Crussière, Matthieu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: For Wireless Personal Area Network (WPAN) systems, resource allocation between several users within a piconet and the coexistence of several piconets are very important points to take into consideration for the optimization of high data rate Ultra Wide Band (UWB) systems. To improve the performance of the Multi-Band OFDM (Orthogonal Frequency Division Multiplex) solution proposed by the Multi-Band OFDM Alliance (MBOA), the addition of a spreading component in the frequency domain is a good solution since it makes resource allocation easier and also offers better robustness against channel frequency selectivity and narrowband interference. The Spread Spectrum - Multi-Carrier - Multiple Access (SS-MC-MA) system proposed in this article offers not only the advantages of Multi-Carrier - Coded Division Multiple Access (MC-CDMA) brought by frequency spreading, but also a more effective dynamic resource allocation in a multi-user and multi-piconet context. These improvements are obtained without increasing the complexity of the radio-frequency part compared to the classical MBOA solution.
Su Ipermodernità di Raffaele Donnarumma
Creators: name: Mussgnug, Florian
Publisher: name: Università degli Studi di Cagliari
Year: 2014

description: Nella letteratura la realtà viene investigata, esplorata, vissuta. È lì che ci rendiamo intellegibili, per così dire, a noi stessi. Anche per questo la letteratura contemporanea ci riguarda tutti, indipendentemente dal suo valore estetico: è lì che capiamo chi siamo, oggi. Spiegare il presente, tuttavia, è un compito arduo e quasi impossibile, come ammonisce Jean-Paul Sartre in un celebre saggio del 1939 su The Sound and the Fury di William Faulkner. L’oggi, scrive Sartre, «non è che un rumore scomposto» e i nostri sforzi di rendere comprensibile quest’attimo «anonimo e sfuggente» assomigliano all’esperienza di un «uomo seduto all’indietro in una decappottabile».
description: Between, Vol 4, N° 8 (2014): Tecnologia, immaginazione e forme del narrare
Magnifying perfect lens and superlens design by coordinate transformation
Creators: name: Tsang, Mankei
name: Psaltis, Demetri
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The coordinate transformation technique is applied to the design of perfect lenses and superlenses. In particular, anisotropic metamaterials that magnify two-dimensional planar images beyond the diffraction limit are designed by the use of oblate spheroidal coordinates. The oblate spheroidal perfect lens or superlens can naturally be used in reverse for lithography of planar subwavelength patterns.
description: 8 pages, 8 figures, v2: submitted, v3: accepted by Physical Review B
Bosonic CNOT gates with Quantum Interrogation
Creators: name: Garcia-Escartin, Juan Carlos
name: Chamorro-Posada, Pedro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We put forward a new CNOT gate scheme with atoms and ions based on quantum interrogation and a bosonic particle extension of the models of linear optics quantum computation. We show how the possibility of particle collision can provide the strong interaction that is needed for universal quantum gates. Two atom optics proposals are provided. Unlike previous schemes, these gates are at the same time nondestructive, valid for arbitrary inputs and can work with a probability as close to unity as desired in the lossless case. Data is encoded into position modes and the gates only require basic atom optics elements, which gives potentially simpler quantum computer implementations.
description: 5 pages, 3 figures, preliminar version
Phenomenology of the nMSSM from colliders to cosmology
Creators: name: Balazs, C.
name: Carena, M.
name: Freitas, A.
name: Wagner, C. E. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Low energy supersymmetric models provide a solution to the hierarchy problem and also have the necessary ingredients to solve two of the most outstanding issues in cosmology: the origin of dark matter and baryonic matter. One of the most attractive features of this framework is that the relevant physical processes are related to interactions at the weak scale and therefore may be tested in collider experiments in the near future. This is true for the Minimal Supersymmetric Standard Model (MSSM) as well as for its extension with the addition of one singlet chiral superfield, the so-called nMSSM. It has been recently shown that within the nMSSM an elegant solution to both the problem of baryogenesis and dark matter may be found, that relies mostly on the mixing of the singlet sector with the Higgs sector of the theory. In this work we review the nMSSM model constraints from cosmology and present the associated collider phenomenology at the LHC and the ILC. We show that the ILC will efficiently probe the neutralino, chargino and Higgs sectors, allowing to confront cosmological observations with computations based on collider measurements. We also investigate the prospects for a direct detection of dark matter and the constraints imposed by the current bounds of the electron electric dipole moment in this model.
description: 44 pp, 10 figures; Fig.9 replaced; discussion on CP violation extended and references added; few minor additions in text about details of the cuts
Type Ia and II supernovae contributions to the metal enrichment in intra-cluster medium observed with Suzaku
Creators: name: Sato, Kosuke
name: Tokoi, Kazuyo
name: Matsushita, Kyoko
name: Ishisaki, Yoshitaka
name: Yamasaki, Noriko Y.
name: Ishida, Manabu
name: Ohashi, Takaya
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We studied the properties of the intra-cluster medium (ICM) in two clusters of galaxies (AWM 7 and Abell 1060) and two groups (HCG 62 and NGC 507) with the X-ray Observatory Suzaku. Based on spatially resolved energy spectra, we measured for the first time precise cumulative ICM metal masses within 0.1 and ~0.3 r_{180}. Comparing our results with supernova nucleosynthesis models, the number ratio of type II (SNe II) to type Ia (SNe Ia) is estimated to be ~3.5, assuming the metal mass in the ICM is represented by the sum of products synthesized in SNe Ia and SNe II. Normalized by the K-band luminosities of present galaxies, and including the metals in stars, the integrated number of past SNe II explosions is estimated to be close to or somewhat higher than the star formation rate determined from Hubble Deep Field observations.
description: 7 pages, 2 figures, accepted for publication in ApJL
Realismo. Quale ritorno?
Creators: name: Tinelli, Giacomo
Publisher: name: Università degli Studi di Cagliari
Year: 2014

description: La lettura di Ipermodernità – dove va la narrativa contemporanea di Raffaele Donnarumma è un passaggio imprescindibile per la comprensione del dibattito, attuale e vivissimo, sulle vie contemporanee della narrativa italiana e occidentale. E non solo perché si tratta di una rassegna ampia e ragionata del presente letterario, che propone alcune coordinate per muoversi nella contemporaneità – operazione difficoltosa a causa della prossimità temporale dell’oggetto d’indagine –, ma anche per il tentativo di declinare in ambito letterario la proposta del ritorno alla realtà che ha nel Manifesto del nuovo realismo (2011) di Maurizio Ferraris il suo programma filosofico. Il libro raccoglie anni di articoli e dibattiti, condotti in gran parte sulle pagine di Allegoria, ed ha il merito di comporre in modo organico e complessivo un discorso rimasto fino ad ora relativamente frammentario.
description: Between, Vol 4, N° 8 (2014): Tecnologia, immaginazione e forme del narrare
Measuring co-authorship and networking-adjusted scientific impact
Creators: name: Ioannidis, John P. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Appraisal of the scientific impact of researchers, teams and institutions with productivity and citation metrics has major repercussions. Funding and promotion of individuals and survival of teams and institutions depend on publications and citations. In this competitive environment, the number of authors per paper is increasing and apparently some co-authors don't satisfy authorship criteria. Listing of individual contributions is still sporadic and also open to manipulation. Metrics are needed to measure the networking intensity for a single scientist or group of scientists accounting for patterns of co-authorship. Here, I define I1 for a single scientist as the number of authors who appear in at least I1 papers of the specific scientist. For a group of scientists or institution, In is defined as the number of authors who appear in at least In papers that bear the affiliation of the group or institution. I1 depends on the number of papers authored Np. The power exponent R of the relationship between I1 and Np categorizes scientists as solitary (R>2.5), nuclear (R=2.25-2.5), networked (R=2-2.25), extensively networked (R=1.75-2) or collaborators (R<1.75). R may be used to adjust for co-authorship networking the citation impact of a scientist. In similarly provides a simple measure of the effective networking size to adjust the citation impact of groups or institutions. Empirical data are provided for single scientists and institutions for the proposed metrics. Cautious adoption of adjustments for co-authorship and networking in scientific appraisals may offer incentives for more accountable co-authorship behaviour in published articles.
description: 25 pages, 5 figures
title: New Conditional Cube Attack on Keccak Keyed Modes
Creators: name: Li, Zheng
name: Dong, Xiaoyang
name: Bi, Wenquan
name: Jia, Keting
name: Wang, Xiaoyun
name: Meier, Willi
Publisher: name: Ruhr-Universität Bochum
Year: 2019

description: The conditional cube attack on round-reduced Keccak keyed modes was proposed by Huang et al. at EUROCRYPT 2017. In their attack, a conditional cube variable was introduced, whose diffusion was significantly reduced by certain key bit conditions. The attack requires a set of cube variables which are not multiplied in the first round while the conditional cube variable is not multiplied with other cube variables (called ordinary cube variables) in the first two rounds. This has an impact on the degree of the output of Keccak and hence gives a distinguisher. Later, the MILP method was applied to find ordinary cube variables. However, for some Keccak based versions with few degrees of freedom, one could not find enough ordinary cube variables, which weakens or even invalidates the conditional cube attack.
In this paper, a new conditional cube attack on Keccak is proposed. We remove the limitation that no cube variables multiply with each other in the first round. As a result, some quadratic terms may appear in the first round. We make use of some new bit conditions to prevent the quadratic terms from multiplying with other cube variables in the second round, so that there will be no cubic terms in the first two rounds. Furthermore, we introduce the kernel quadratic term and construct a 6-2-2 pattern to reduce the diffusion of quadratic terms significantly, where the Θ operation even in the second round becomes an identity transformation (CP-kernel property) for the kernel quadratic term. Previous conditional cube attacks on Keccak only explored the CP-kernel property of Θ operation in the first round. Therefore, more degrees of freedom are available for ordinary cube variables and fewer bit conditions are used to remove the cubic terms in the second round, which plays a key role in the conditional cube attack on versions with very few degrees of freedom. We also use the MILP method in the search of cube variables and give key-recovery attacks on round-reduced Keccak keyed modes.
As a result, we reduce the time complexity of key-recovery attacks on 7-round Keccak-MAC-512 and 7-round Ketje Sr v2 from 2111, 299 to 272, 277, respectively. Additionally, we have reduced the time complexity of attacks on 9-round KMAC256 and 7-round Ketje Sr v1. Besides, practical attacks on 6-round Ketje Sr v1 and v2 are also given in this paper for the first time.
description: IACR Transactions on Symmetric Cryptology, Volume 2019, Issue 2
title: FridaysForFuture : Digitalisierung macht Protest wissenschaftlicher
Creators: name: Hagedorn, Gregor
Publisher: name: Deutsches GeoForschungsZentrum GFZ
Year: 2019

description: Dank FridaysForFuture steht die Erdsystemforschung im Mittelpunkt öffentlicher Debatten. Die Digitalisierung unterstützt diese Entwicklung. Ein Gastbeitrag von Dr. Gregor Hagedorn von Scientists for Future.
Field-induced incommensurate order for the quasi-one-dimensional XXZ model in a magnetic field
Creators: name: Okunishi, Kouichi
name: Suzuki, Takahumi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate phase transitions of the quasi-one-dimensional XXZ model in a magnetic field, using the bosonization combined with the mean field treatment of the inter-chain interaction. We then find that the field induced incommensurate order is certainly realized in the low field region, while the transverse staggered order appears in the high field region. On the basis of the result, we discuss the field-induced phase transition recently observed for BaCo2V2O8.
description: 6 pages, 3 figures, to appear in PRB
Chiral transition in a strong magnetic background
Creators: name: Fraga, Eduardo S.
name: Mizher, Ana Júlia
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The presence of a strong magnetic background can modify the nature and the dynamics of the chiral phase transition at finite temperature. We compute the modified effective potential in the linear sigma model with quarks to one loop in the $\bar{MS}$ scheme for $N_{f}=2$. For fields $eB\sim 5 m_π^{2}$ and larger a crossover is turned into a weak first-order transition. We discuss possible implications for non-central heavy ion collisions at RHIC and LHC, and for the primordial QCD transition.
description: 7 pages, 7 figures
Physical properties of the jet in 0836+710 revealed by its transversal structure
Creators: name: Perucho, M.
name: Lobanov, A. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Studying the internal structure of extragalactic jets is crucial for understanding their physics. The Japanese-led space VLBI project VSOP has presented an opportunity for such studies, by reaching baseline lengths of up to 36,000 km and resolving structures down to an angular size of $\approx 0.3$ mas at 5 GHz. VSOP observations of the jet in 0836+710 at 1.6 and 5 GHz have enabled tracing of the radial structure of the flow on scales from 2 mas to 200 mas along the jet and determination of the wavelengths of individual oscillatory modes responsible for the formation of the structure observed. We apply linear stability analysis to identify the oscillatory modes with modes of Kelvin-Helmholtz instability that match the wavelengths of the structures observed. We find that the jet structure in 0836+710 can be reproduced by the helical surface mode and a combination of the helical and elliptic body modes of Kelvin-Helmholtz instability. Our results indicate that the jet is substantially stratified and different modes of the instability grow inside the jet at different distances to the jet axis. The helical surface mode can be driven externally, and we discuss the implications of the driving frequency on the physics of the active nucleus in 0836+710.
description: Accepted for publication in Astronomy & Astrophysics Letters
Stochastic gravity and turbulence
Creators: name: Waeber, Sebastian
name: Yarom, Amos
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Chaotic Dynamics (nlin.CD)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study the ensemble average of the thermal expectation value of an energy momentum tensor in the presence of a random external metric. In a holographic setup this quantity can be read off of the near boundary behavior of the metric in a stochastic theory of gravity. By numerically solving the associated Einstein equations and mapping the result to the dual boundary theory, we find that the non relativistic energy power spectrum exhibits a power law behavior as expected by the theory of Kolmogorov.
description: 24 pages, 7 figures
A Comprehensive View of Circumstellar Disks in Chamaeleon I: Infrared Excess, Accretion Signatures and Binarity
Creators: name: Damjanov, Ivana
name: Jayawardhana, Ray
name: Scholz, Alexander
name: Ahmic, Mirza
name: Nguyen, Duy C.
name: Brandeker, Alexis
name: van Kerkwijk, Marten H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a comprehensive study of disks around 81 young low-mass stars and brown dwarfs in the nearby ~2-Myr-old Chamaeleon I star-forming region. We use mid-infrared photometry from the Spitzer Space Telescope, supplemented by findings from ground-based high-resolution optical spectroscopy and adaptive optics imaging. We derive disk fractions of 52 (+/-6) % and 58 (+6/-7) % based on 8-micron and 24-micron colour excesses, respectively, consistent with those reported for other clusters of similar age. Within the uncertainties, the disk frequency in our sample of K3-M8 objects in Cha I does not depend on stellar mass. Diskless and disk-bearing objects have similar spatial distributions. There are no obvious transition disks in our sample, implying a rapid timescale for the inner disk clearing process; however, we find two objects with weak excess at 3-8 microns and substantial excess at 24 microns, which may indicate grain growth and dust settling in the inner disk. For a sub-sample of 35 objects with high-resolution spectra, we investigate the connection between accretion signatures and dusty disks: in the vast majority of cases (29/35) the two are well correlated, suggesting that, on average, the timescale for gas dissipation is similar to that for clearing the inner dust disk. The exceptions are six objects for which dust disks appear to persist even though accretion has ceased or dropped below measurable levels. Adaptive optics images of 65 of our targets reveal that 17 have companions at (projected) separations of 10-80 AU. Of the five <20 AU binaries, four lack infrared excess, possibly indicating that a close companion leads to faster disk dispersal. The closest binary with excess is separated by ~20 AU, which sets an upper limit of ~8 AU for the outer disk radius. (abridged)
description: accepted for publication in the Astrophysical Journal
Time-resolved detection of single-electron interference
Creators: name: Gustavsson, S.
name: Leturcq, R.
name: Studer, M.
name: Ihn, T.
name: Ensslin, K.
name: Driscoll, D. C.
name: Gossard, A. C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate real-time detection of self-interfering electrons in a double quantum dot embedded in an Aharonov-Bohm interferometer, with visibility approaching unity. We use a quantum point contact as a charge detector to perform time-resolved measurements of single-electron tunneling. With increased bias voltage, the quantum point contact exerts a back-action on the interferometer leading to decoherence. We attribute this to emission of radiation from the quantum point contact, which drives non-coherent electronic transitions in the quantum dots.
description: Supporting Information Available: http://www.nanophys.ethz.ch/gallery/movies/SingleElectronAB/index.htm contains a movie showing how the interference pattern builds up in real-time as electrons pass through the structure one-by-one