197,227 research outputs found
Stratigraphic and photographic documentation of the Ksar Akil excavations.
No full text<p>(a) Stratigraphic sequence as established by the early excavations of Boston College. The section drawing of the 23 m-deep stratigraphy illustrates both the archaeological levels (in Latin numerals) and the broad techno-typologically distinct phases (Mousterian, Initial Upper Palaeolithic, etc.) that these levels have been ascribed to; (b) The discovery of Egbert (Ksar Akil 1) in 1938. Close up of the skull <i>in situ</i>. Image copyright Pitt Rivers Museum, University of Oxford (accession number: 1998.294.820); (c) Inferior view of the partial right maxilla of Ethelruda (Ksar Akil 2), modified after <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0072931#pone.0072931-Ewing4" target="_blank">[32]</a>.</p
Identification for control: Deterministic algorithms and error bounds
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by the University of Cambridge.This dissertation deals with frequency domain identification of linear dynamic systems in a deterministic set-up. Various untuned algorithms are suggested, including one which is robustly convergent and asymptotically optimal (in n-width sense) for a finite model order. The suggested algorithms can easily be implemented in commercially available software for convex optimization
Un nouveau type de burin à Ksar Akil (Liban)
No full textNewcomer M.H. Un nouveau type de burin à Ksar Akil (Liban). In: Bulletin de la Société préhistorique française. Comptes rendus des séances mensuelles, tome 68, n°9, 1971. pp. 267-272
Exponential Stabilization of an Euler-Bernoulli Beam by a Heat Equation Involving Memory Effects
No full textThis study delves into the dynamic behavior of a coupled system comprising an Euler-Bernoulli beam equation and a heat equation with memory, governed by different heat conduction laws. These laws, represented by a parameter m include the Coleman-Gurtin and Gurtin-Pipkin laws, which uniquely influence the material's temperature evolution. By formulating a set of partial differential equations along with appropriate boundary and transmission conditions, we lay the groundwork for analyzing the coupled system's behavior. Our investigation primarily centers on understanding the asymptotic properties of the solution semigroup within the framework of Dafermos history space. We establish exponential stability under both the Coleman-Gurtin and Gurtin-Pipkin heat conduction models by imposing distinct conditions on the relaxation function. The article concludes with a comparison of the two heat conduction laws and a discussion on potential directions for extending this research
Exponential Stability for a Degenerate/Singular Beam-Type Equation in Non-Divergence Form
No full textThe paper deals with the stability of a degenerate/singular beam equation in non-divergence form. In particular, we assume that the degeneracy and the singularity are at the same boundary point and we impose clamped conditions where the degeneracy occurs and dissipative conditions at the other endpoint. Using the energy method, we provide some conditions to obtain the stability for the considered problem
Correction to: Primary Sjögren’s syndrome (pSS)-related cerebellar ataxia: a systematic review and meta-analysis (Acta Neurologica Belgica, (2021), 10.1007/s13760-021-01784-1)
No full textThe first name and family name of all authors have been incorrectly swapped in the original publication. The complete correct author names are given below. Andreas Liampas, Antonios Nteveros, Konstantinos Parperis, Mohammed Akil, Efthymios Dardiotis, Elizabeth Andreadou, Marios Hadjivassiliou, Panagiotis Zis. The original article has been corrected. © 2021, Belgian Neurological Society
Flexural behaviour of pultruded jute/glass and kenaf/glass hybrid composites monitored using acoustic emission
No full textThe flexural (before and after cyclic loading up to 50% of ultimate load) and indentation behaviour of pultruded jute/glass and kenaf/glass hybrid polyester composites has been monitored using acoustic emission, and compared with that of kenaf fiber composites. In all hybrids, natural fiber content was 40 wt.%, while glass fiber one was 25 wt.%. Acoustic emission (AE) has been used for real-time monitoring during flexural and indentation loading: the analysis concentrated on AE resuming during reloading (Felicity ratio) and AE activity at low loads during unloading (crack closure effect). The results show that the introduction of this large amount of reinforcement appears quite effective on jute fiber reinforced laminates, although with a significant effect of fiber architecture, whilst it did not yield comparable results in kenaf fiber laminates. This was attributed to the insufficient fiber impregnation and to the need for improving the control of fiber orientation in the laminate. (C) 2010 Elsevier B.V. All rights reserved
Boundary controllability of coupled degenerate Euler-Bernoulli beam equations
No full textThe aim of this paper is to study the null controllability property for two coupled degenerate beam equations where the control function acts only on one of the two equations. The beam equations are coupled via velocity damping terms, where the velocity of the second equation appears in the first equation and vice versa. As a first step, we analyze the well-posedness of the associated homogeneous adjoint problem in suitable functional spaces using semigroup theory. Then, we prove the validity of an indirect observability estimate for this kind of problem in a sufficiently large time, provided that the coupling coefficient is assumed to be positive and small. By means of this estimate and applying the classical Hilbert uniqueness method, we deduce that the original system is null controllable. We also give the explicit controllability time which depends both on the degree of the degeneration and the coupling term
Multi-covert channel attack in the cloud
No full textFrequently, it is believed that the adoption of encryption is adequate to ensure the safety of the message. However, encryption only restricts unapproved individuals from decoding the message. Whereas in many circumstances, the mere presence of communication or variations in communication patterns, such as an increase in message rate, is sufficient to raise doubt and initiate alerts. One of the best ways to bypass that is by using covert channels. In this paper, we create innovative protocols that use multiple covert channels working in parallel to exfiltrate data from a remote-controlled machine to our server. The provided protocols guarantee the completeness and unforgeability of the exfiltrated data. We analyze the difference in performance between the created protocols and provide mathematical equations to evaluate them
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