473 research outputs found
Il Carcer nella produzione di Cardano
No full textAlongside a larger analysis of Cardano's moral philosophy since the De consolatione (1542), the essay focuses on the dialogue Carcer, and suggests a relationship between the difficulties encountered by the author in the Duchy of Milan in 1560-61, and the trial of 1570 in Bologna. Special attention is devoted to the philosophical reasons that support in the Carcer the Plutarchean sera numinis vindicta, one of Cardano's favorites topics
Comparing three possible hypoelliptic Laplacians on the 5-dimensional Cartan group via div-curl type estimates
Get PDFOn general Carnot groups, the definition of a possible hypoelliptic Hodge-Laplacian on forms using
the Rumin complex has been considered in (M. Rumin, “Differential geometry on C-C spaces and application
to the Novikov-Shubin numbers of nilpotent Lie groups,” C. R. Acad. Sci., Paris Sér. I Math., vol. 329, no. 11, pp.
985–990, 1999, M. Rumin, “Sub-Riemannian limit of the differential form spectrum of contactmanifolds,” Geom.
Funct. Anal., vol. 10, no. 2, pp. 407–452, 2000), where the author introduced a 0-order pseudodifferential operator
on forms. However, for questions regarding regularity for example, where one needs sharp estimates, this
0-order operator is not suitable. Up to now, there have only been very few attempts to define hypoelliptic Hodge-
Laplacians on forms that would allow for such sharp estimates. Indeed, this question is rather difficult to address
in full generality, the main issue being that the Rumin exterior differential dc is not homogeneous on arbitrary
Carnot groups. In this note, we consider the specific example of the free Carnot group of step 3 with 2 generators,
and we introduce three possible definitions of hypoelliptic Hodge-Laplacians.We compare how these three possible
Laplacians can be used to obtain sharp div-curl type inequalities akin to those considered by Bourgain &
Brezis and Lanzani & Stein for the de Rham complex, or their subelliptic counterparts obtained by Baldi, Franchi
& Pansu for the Rumin complex on Heisenberg groups
Possession
No full textThis chapter of the Historical Latin Syntax traces the evolution and use of predicative possessive constructions from Archaic to Late Latin. We demonstrate that, far from being merely a so-called “be-language”, Latin is a language where the major possessive type is based on a transitive verb (habeo) since the archaic stage. A textual, contrastive analysis of the habeo x and mihi est x types proves that between these two constructions there is a functional differentiation (i.e. syntactic and pragmatic, while the semantic level is relevant only to a minor extent). This, thus, explains: their different occurrence in the Latin corpus; their division-of-labour and, therefore, their coexistence through the history of Latin; and, finally, the diahronic evolution towards the transitive type. A comparison between the mihi est x and the genitive predicative type, which are fully differentiated on a functional plane, completes the picture of the whole architecture of predicative possession in Latin. Consequences can be drawn on the general plane, as “mixted” types (i.e. languages that are both have- and be-), such as Latin, must be taken into consideration when we approach the typology of predicative possession.
An analysis of attributive constructions is then offered, at the light of parameters such as: the order of the elements in the sequence, the definite status of the possessor/possessum constituents of the phrase, the semantic profile of the relation expressed, and the different morphological markers, etc.. Conclusions partly confirm previous hypotheses about the relation between the Latin stage and the Indoeuropean stage, while several generalizations from the typological point of view have to be adjusted (e.g. external possessor constructions).
The part on predicative possession is mainly due to Andrea Nuti; the part on attributive possession mainly to Philip Baldi. However, as the whole chapter is the result of a deep, mutual work carried on in full cooperation, the authors have agreed not to state explicitly and neatly an author-to-pages correspondence
Moonlighting at replication forks - a new life for homologous recombination proteins BRCA1, BRCA2 and RAD51
No full textCoordination between DNA replication and DNA repair ensures maintenance of genome integrity, which is lost in cancer cells. Emerging evidence has linked homologous recombination (HR) proteins RAD51, BRCA1 and BRCA2 to the stability of nascent DNA. This function appears to be distinct from double-strand break (DSB) repair and is in part due to the prevention of MRE11-mediated degradation of nascent DNA at stalled forks. The role of RAD51 in fork protection resembles the activity described for its prokaryotic orthologue RecA, which prevents nuclease-mediated degradation of DNA and promotes replication fork restart in cells challenged by DNA-damaging agents. Here, we examine the mechanistic aspects of HR-mediated fork protection, addressing the crosstalk between HR and replication proteins
Adaptive synchronization in networks with heterogeneous uncertain Kuramoto-like units
No full textWe analyze adaptive synchronization capabilities in networks with Kuramoto-like units whose dynamical features are unknown and thus synchronization protocols must exhibit co-evolution capabilities. In the presence of heterogeneous and uncertain units, synchronization should be enabled by appropriate adaptive protocols that counteract the effect of heterogeneity. An interaction protocol is presented that is used by the units to communicate with each other: the protocol is based on a distributed disagreement measure. The aim of the protocol is to adapt feedback and coupling gains, so as to guarantee the emergence of a synchronous solution. The adaptive strategy is distributed, i.e. each unit self-determines the strength of its gains by using only neighboring measurements. Convergence of the synchronization error to zero is shown via Lyapunov analysis, and numerical examples demonstrate the effectiveness of the proposed protocol.Accepted Author ManuscriptTeam Bart De Schutte
Valuing a Leveraged Buyout: Expansion of the Adjusted Present Value by means of Real Options Analysis
No full textA major flaw in using the adjusted present value (APV) method to value the target firm of a leveraged buyout is that it results in systematic undervaluation of the firm in question. The author proposes to remedy the problem by employing real options analysis to expand the target firm's APV on its equity side. Two real options may be identified as being inherent in the leveraged buyout structuring process: a financial default call option and an operating default call option, both of American type. The resulting expanded equity value allows for the flexible management of firm value uncertainty while continuing to incorporate the extra value creation deriving from the exploitation of the tax shield
A distributed disagreement-based protocol for synchronization of uncertain heterogeneous agents
No full textIn networks with heterogeneous and uncertain agents, fixed-gain control can lead to synchronization only if the uncertainties are relatively small. If the uncertainties are larger, we need to develop adaptive-gain approaches to achieve synchronization. In this work we propose an adaptive synchronization protocol, in case of full-state measurement, for uncertain heterogeneous agents based on a distributed disagreement reasoning. Specifically, we first define unknown gains (feedback and coupling gains) that could lead all agents to a homogeneous behavior and thus synchronization: however, since these gains are unknown in view of the unknown dynamics, we design adaptive laws for these gains that lead the agents toward synchronization. The adaptive laws are driven by a disagreement error which is calculated among neighbors: a Lyapunov analysis is presented for showing convergence of the synchronization error to zero.Accepted Author ManuscriptTeam Bart De Schutte
The XMM-Newton long look of NGC 1365: uncovering of the obscured X-ray source
No full textWe present an analysis of the extreme obscuration variability observed during an XMM–Newton 5-d continuous monitoring of the active galactic nuclei (AGN) in NGC 1365. The source was in a reflection-dominated state in the first ∼1.5 d, then a strong increase in the 7–10 keV emission was observed in ∼10 h, followed by a symmetric decrease. The spectral analysis of the different states clearly shows that this variation is due to an uncovering of the X-ray source. From this observation, we estimate a size of the X-ray source DS < 1013 cm, a distance of the obscuring clouds R∼ 1016 cm and a density n∼ 1011 cm−3. These values suggest that the X-ray absorption/reflection originates from the broad-line region clouds. This is also supported by the resolved width of the iron narrow Kα emission line, consistent with the width of the broad Hβ line
Adaptive leader-follower synchronization over heterogeneous and uncertain networks of linear systems without distributed observer
No full textA challenging task in network synchronization is steering the network toward a coherent solution, when the dynamics of the constituent systems are heterogeneous and uncertain. In this situation, synchronization can be achieved via adaptive protocols (with adaptive feedback gains or adaptive coupling gains, or both). However, as state-of-the-art synchronization methods adopt a distributed observer architecture, they require to communicate extra observer variables among neighbors, in addition to the neighbors' states (or outputs). The distinguishing feature of this article is to show that for heterogeneous and uncertain networks of some classes of linear systems, synchronization is possible without the need for any distributed observer. Such classes are in line with those in model reference adaptive control literature. Lyapunov analysis is used to derive a new adaptive synchronization protocol with the simplest communication architecture, in which both feedback and coupling gains are adapted without any extra communication other than neighbors' states (in the full-state information case) or neighbors' outputs (in the partial-state information case). Accepted Author ManuscriptTeam Bart De Schutte
Energy storage on ships
No full textEnergy efficiency measures are a priority in the near term to reduce the carbon intensity of maritime sector in the next years. Since 2017, IMO has been proposing policies to rapidly promote the adoption of cleaner technologies and fuels for oceangoing vessels. Lithium-ion batteries have been recently installed onboard smaller scale ferries and passenger vessels either as the primary energy source, or then as a hybrid solution. Various lithium-ion battery chemistries are available, with sources pointing at lithium nickel manganese cobalt oxide as the most feasible solution for ships. In this Chapter (Section 5.2), the authors focus their attention on the design, modeling, and control of maritime batteries, presenting and discussing real-life applications on sizing, modeling and control. Thermal energy storage (TES) technologies are focused on mismatching the gap between the energy production and consumption by recovering surplus energy during the generation to be used on periods of high demand. Although large amount of studies cover the application of TES technology in fields like renewable energies or industrial applications, very few authors evaluated the use of TES systems in ships to increase the efficiency of the engines and reduce their CO2 emissions. In Section 5.3, an analysis of the potential use of TES systems is presented, considering the heat and cold sources in different types of ships, and its use on board. Potential drawbacks of the use of TES on board ships, such as the integration with existing propulsion layouts, the requirements of weight and volume, are also discussed.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.Ship Design, Production and Operation
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