248 research outputs found
Virtuelle Realität: Der Friedenspreis für Jaron Lanier - und die Missverständnisse, auf denen er beruht.
No full textVirtuelle Realität
Der Friedenspreis für Jaron Lanier - und die Missverständnisse, auf denen er beruht
Big Data, Big Libraries, Big Problems?: the 2014 LibTech Anti-talk?
No full textThe desire to create automatons is a familiar theme in human history, and during the age of the Enlightenment mechanical automatons became not only an “emblem of the cosmos”, but a symbol of man’s confidence that he would unlock nature’s greatest mysteries and fully harness her power. And yet only a century later, automatons had begun to represent human repression and servitude, a theme later picked up by writers of science fiction. Man’s confidence undeterred, the endgame of the modern scientific and technological mindset, or MSTM, seems to be increasingly coming into view with the rise of “information technology” in general and “Big data” in particular. Along with those who wield them, these can be seen as functioning together as a “mechanical muse” of sorts – surprisingly alluring – and, like a physical automaton can serve as a symbol – a microcosm – of what the MSTM sees (at the very least in practice) as the cosmic machine, our “final frontier”. And yet, individuals who unreflectively participate in these things – giving themselves over to them and seeking the powers afforded by the technology apart from technology’s rightful purposes – in fact yield to the same pragmatism and reductionism those wielding them are captive to. Thus, they ultimately nullify themselves philosophically, politically, and economically – their value increasingly being only the data concerning their persons, and its perceived usefulness. Likewise libraries, the time-honored place of, and symbol for, the intellectual flowering of the individual, will, insofar as they spurn the classical liberal arts (with the idea that things are intrinsically good, and in the case of humans, special as well) in favor of the alluring embrace of MSTM-driven “information technology” and Big data - unwittingly contribute to their irrelevance and demise as they find themselves increasingly less needed, valued, wanted. Likewise for the liberal arts as a whole, and in fact history itself, if the acid of a “science” untethered from what is, in fact, good (intrinsically), continues to gain strengt
Dependence of strong-field photoelectron angular distributions on molecular orientation
No full textJaron-Becker A, Becker A, Faisal F. Dependence of strong-field photoelectron angular distributions on molecular orientation. JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS. 2003;36(21):L375-L380.We have analysed angular distributions of the photoelectron yields arising from strong-field ionization of diatomic and polyatomic linear molecules using a leading-order intense-field S-matrix theory. For molecules with active pi electrons the distribution is found to strongly depend on the degree of molecular alignment, showing a nodal minimum along the laser polarization direction as a characteristic signature
Signatures of molecular orientation and orbital symmetry in strong-field photoelectron angular and energy distributions of diatomic molecules and small carbon clusters
No full textJaron-Becker A, Becker A, Faisal F. Signatures of molecular orientation and orbital symmetry in strong-field photoelectron angular and energy distributions of diatomic molecules and small carbon clusters. LASER PHYSICS. 2004;14(2):179-185.Using leading order intense-field S-matrix analysis, we study the angular and energy distribution of the photoelectron for multiphoton ionization of diatomic molecules and linear carbon clusters. We show that alignment of molecules can be simply determined from the observation (i) of a nodal minimum along the laser polarization direction in the photoelectron angular distributions for molecules with active pi electrons or (ii) of a minimum in the above threshold ionization spectra of homonuclear diatomics at high energies. The origins, as well as the conditions under which these signatures can be observed in the experiment, are discussed
Saturated ionization of fullerenes in intense laser fields
No full textJaron-Becker A, Becker A, Faisal F. Saturated ionization of fullerenes in intense laser fields. PHYSICAL REVIEW LETTERS. 2006;96(14): 143006.We investigate the ionization of icosahedral fullerenes (C-20, C-60, C-80, and C-180) in an intense laser pulse using the S-matrix theory. The results obtained are in excellent agreement with the recent observations of unexpectedly high saturation intensities of the Buckminster fullerene and its multiply charged ions. Our analysis strongly suggests that the related phenomenon of suppressed ionization of these complex fullerenes is due to the finite cage size and the "multislit" interference effect between partial waves emitted from the different nuclei rather than to a dynamical multielectron polarization effect
An old quarrel, revisited (Review of "You are Not a Gadget" by Jaron Lanier, "Digital Barbarism" by Mark Helprin, and "The Net Delusion" by Evgeny Morozov)
No full textThis comparative book review of You are Not a Gadget (Knopf, 2010, 224 pages) by Jaron Lanier, Digital Barbarism (Harper, 2010, 232 pages) by Mark Helprin, and The Net Delusion (PublicAffairs, 2011, 432 pages) by Evgeny Morozov, examines the anxiety about loss of personhood and the external threats to the individual present in society, from very different points of view. The author states that it is neither internet-boosterism, nor the information-freedom or copyleft movements that threaten the individual’s social position and freedom of expression. The real threats to the individual are those who would try to control free expression, whether such people or organizations are represented by the state, corporate interests, or perhaps even a small group of well-motivated activists.
@Journal of Professional Communication, all rights reserved
Vienna Correlator Report 2021–2022
No full textThe Vienna Correlator is operated by the research unit Higher Geodesy of the Technische University at Wien (TU Wien). The Vienna Scientific Cluster (VSC), a supercomputer located in Vienna, is used as a hardware component. A bandwidth of 10 GBit/s (shared by all VSC users), 480 compute cores, and 1 PByte memory for VLBI correlation are available. Three people are actively involved in VLBI correlation: J. Gruber, F. Jaron, and L. Baldreich. In 2021, seven out of a total of 27 (26%) VGOS-OPS sessions, and in 2022, 12 out of a total of 44 (27%) were correlated in Vienna. In the EU-VGOS project, sessions were observed, correlated, analyzed, and new software solutions were organized and developed
Markov Chains and Hitting Times for Error Accumulation in Quantum Circuits
No full textWe study a classical model for the accumulation of errors in multi-qubit quantum computations. By modeling the error process in a quantum computation using two coupled Markov chains, we are able to capture a weak form of time-dependency between errors in the past and future. By subsequently using techniques from the field of discrete probability theory, we calculate the probability that error quantities such as the fidelity and trace distance exceed a threshold analytically. The formulae cover fairly generic error distributions, cover multi-qubit scenarios, and are applicable to the randomized benchmarking protocol. To combat the numerical challenge that may occur when evaluating our expressions, we additionally provide an analytical bound on the error probabilities that is of lower numerical complexity. Besides this, we study a model describing continuous errors accumulating in a single qubit. Finally, taking inspiration from the field of operations research, we illustrate how our expressions can be used to decide how many gates one can apply before too many errors accumulate with high probability, and how one can lower the rate of error accumulation in existing circuits through simulated annealing.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.Network Architectures and Service
Ionization of N-2, O-2, and linear carbon clusters in a strong laser pulse
No full textJaron-Becker A, Becker A, Faisal F. Ionization of N-2, O-2, and linear carbon clusters in a strong laser pulse. PHYSICAL REVIEW A. 2004;69(2): 023410.Multiphoton ionization of linear molecules is studied using the strong-field S-matrix approach. Numerical calculations for the angular distribution and the energy spectrum of the photoelectron as well as the total ionization rates and yields in an intense linearly polarized laser pulse are performed. Results are obtained for molecules aligned along the polarization axis and for ensembles of molecules having a random orientation of the molecular axis with respect to the polarization direction. Signatures of the molecular geometry and the orbital symmetry are identified and discussed with reference to molecular imaging and alignment. It is found that these signatures are clearly marked for the diatomic molecules C-2, N-2, and O-2, but are much weaker for the group of linear carbon clusters due to the polyatomic character as well as to the competing contributions from different valence shells of these molecules. Finally, predictions of the present theory for the dependence of the total ionization rates and yields on the orientation of the molecule are compared with other theoretical models and recent experimental data
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