26,578 research outputs found
Multivariate Polarimetric Bistatic Clutter Statistical Analysis
No full textThis paper deals with the analysis of simultaneously collected co- and cross-polarized bistatic sea-clutter returns with special emphasis on their representation as a Spherically Invari-ant Random Process (SIRP). The study is conducted by using appropriate testing procedures involving the complex envelope of the measured data that provide both first- and higher-order compatibility conditions. The results highlight that the SIRP model is a good candidate for the representation of bistatic coherent clutter, and usually the coherence time of the SIRP texture is longer than that in the monostatic case.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Disciplining Orchestration and Conversation in Service-Oriented Computing
No full textWe give a formal account of a calculus for modeling service-based systems, suitable to describe both service composition (orchestration) and the protocol that services run when invoked (conversation). The calculus includes primitives for defining and for invoking services, for isolating conversations between requesters and providers of services, and primitives for orchestrating services, that is, to make use of existent services as building blocks to accomplish complex tasks.
The calculus is equipped with a reduction and a labeled transition semantics; an equivalence result relates the two. To hint how the structuring mechanisms of the language can be exploited for static analysis we present a simple type system guaranteeing the compatibility between client and server protocols, an application of bisimilarity to prove equivalence among services, and we discuss deadlock-avoidance
Dual Chemical-Electric Propulsion Systems Design for Interplanetary CubeSats
No full textInterplanetary CubeSats enable universities and smallspacecraft- consortia to pursue low-cost, high-risk and highgain Solar System Exploration missions, especially Mars; for which cost-effective, reliable, and flexible space systems need to be developed. Missions to Mars can be achieved through a) in-situ deployment by a mothership and b) highly flexible stand-alone CubeSats on deep-space cruise. The current work focuses on sizing and establishing critical design parameters for dual chemical-electric propulsion systems that shall enable a stand-alone 16U CubeSat mission on a hybrid high-thrust & low-thrust trajectory. High thrust is used to escape Earth whereas low-thrust is used in autonomous deep-space cruise, achieving ballistic capture, and emplacement on an areosynchronous orbit at Mars. Chemical propulsion characterisation is based on V requirement and a heuristic optimisation of thrust, specific impulse and burn time while balancing transfer time and propellant mass. Limitations are set to minimise destabilising momentum. Electric propulsion characterisation is based on the V, power consumption, and trajectory requirements for fueloptimal and time-optimal strategies. The sizes amount to 16% and 21% of the assumed total mass ( 30 kg) for chemical and electric systems, respectively.Space Systems Egineerin
A. PUSHKIN IN LITERARY CRITICISM OF F. SOLOGUB: TYPOLOGY OF POETRY
No full textThe article analyzes the criticism of F. Sologub. The negative attitude of the master of symbolism towards A. Pushkin comes from peculiarities of his philosophical and aesthetic views. The author concludes that F. Sologub divides poetry into two types: extroverted and introverted; the art, in which a poet’s aesthetic experience refers to the events occurring in observable space and time, and the art in which a poet’s aesthetic experience refers to his inner existential conclusions. In this context the author touches upon the poetry of G. Byron, M. Lermontov, V. Zhukovsky, E. Poe, Novalis, P. Verlaine
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Measurement of the polarization amplitudes and triple product asymmetries in the B0s → Φ Φ decay
No full text<p>Using 1.0 fb−1 of pp collision data collected at a centre-of-mass energy of s√=7 TeV with the LHCb detector, measurements of the polarization amplitudes, strong phase difference and triple product asymmetries in the B0s→ϕϕ decay mode are presented. The measured values are</p>
<p>|A0|2=0.365±0.022(stat)±0.012(syst),|A⊥|2=0.291±0.024(stat)±0.010(syst),cos(δ∥)=−0.844±0.068(stat)±0.029(syst),AU=−0.055±0.036(stat)±0.018(syst),AV=0.010±0.036(stat)±0.018(syst).</p>
b-Generalized Skew Derivations on Multilinear Polynomials in Prime Rings
No full textLet R be a prime ring of characteristic different from 2, Qr be its right Martindale quotient ring and C be its extended centroid. In this paper we define b-generalized skew derivations of prime rings. Then we describe all possible forms of two b-generalized skew derivations F and G satisfying the condition F(x)x − xG(x) = 0, for all x ∈ S, where S is the set of the evaluations of a multilinear polynomial f(x1, ..., xn) over C with n non-commuting variables. Several potential research topics related to our current work are also presented. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG
CURRENT PROBLEMS OF THE SCIENCE OF LAW: A CIVILIST’S VIEW. REVIEW OF THE MONOGRAPH OF V. F. POPONDOPULO “HUMAN ACTIVITY: LEGAL FORMS OF IMPLEMENTATION AND PUBLIC ORGANIZATION” (M.: PROSPECT, 2021. 736 P.)
No full textThe article provides a detailed analysis of the monograph V. F. Popondopulo “Human activity: legal forms of implementation and a public organization”. The review author notes the relevance of the monograph, its integrated and comprehensive nature, allowing to deeply explore the phenomenon of human activity as the basis of law enforcement. According to the author, the concept developed by V. F. Popondopulo has a high scientific and practical value, since it lays the foundation of the theory of law that promotes the crisis of the theoretical and methodological foundations of sectoral legal sciences, primarily the science of civil law. Even though in the monograph V. F. Popondopulo present certain discussion provisions, they, according to the author, not only do not reduce the values of the study, but also stimulate an in-depth study of the problems considered in the study
Avaliação da germinação de sementes de lírio-da-caatinga [Zephyranthes sylvatica (Mart.) Baker] sob temperatura e luminosidade diferentes.
No full textO objetivo deste estudo foi avaliar a germinação de sementes do lírio-da-caatinga sob as condições de temperatura e luminosidade diferentes
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