304 research outputs found
Nuclear spin dynamics of donor-bound electrons in GaAs
Modern computer processors are nowadays approaching limits due to their quantum limitations. The basic principle of modern electronics is measuring a small electrical charge of electrons passing through electronic circuits. An alternative approach based on novel materials could be the solution, which instead relies on the fundamental quantum- mechanical property – spin. The fundamental requirements that apply to a device based on quantum spin qubits include the ability to scale a quantum system, simplicity of creating and reading of the quantum state, long coherence time, and universal set of quantum gates. Concerning nuclear and electron spin states are of particular interest in the field of solid-state qubits manipulating where individual charge and spin carriers can be strongly decoupled from their environment so that the processes destroying the quantum coherence in bulk are largely suppressed. This work is concentrated on the nuclear spin system in GaAs and contributes to the research field of semiconductor nuclear spin physics. In this work, the nuclear spin dynamics of a donor-bound electron was studied in GaAs with n and p doping via optical spectroscopy technique. Since the optical operation of a mesoscopic nuclear spin ensemble is a complex and nonlinear process that involves transferring the angular momentum and energy between nuclear spins and optically-oriented localized electrons, the fundamental optical methods and initial experimental ideas that were formed a structure of this dissertation trace back to the studies of spin-related phenomena in atomic vapors. The conducted research sheds some more light on the complex interdependent system formed by the electron spin and the ensemble of surrounding nuclear spins in the conventional semiconductor – the bulk GaAs. Special attention was given to the detailed study of the nuclear spin relaxation times under a wide range of controlled physical conditions of the experiments. The developed theoretical models explain the whole set of experimental results. It is assumed that this study is another step towards the understanding of this challenging system that can lead to implementations in future quantum information technologies
Giambattista Vicos Bibelwissenschaft. Giganten als „Übersetzer“ der heidnischen Geselligkeit
The paper deals with the ways Giambattista Vico approaches the Baroque erudite gigantology and Biblical account of the Babylonian confusion of tongues. Focusing primarily on Vico’s treatise The Constancy of Philology (second part of De constantia jurisprudentis), we set ourselves the goal to point out the line of historical development located between two major tracks of the Vichian history of nations – that of the gentiles and that of the Jews. Our study made it possible to consider the Vico’s science as resulting of an interaction of various disciplinary palimpsests and discursive splinters, cut short and not written to the end – Protestant exegesis or historiosophy of the prisca sapientia among them.Članak se bavi načinima na koje Giambattista Vico pristupa baroknoj eruditskoj gigantologiji te biblijskom prikazu babilonske pomutnje jezika. Fokusirajući se prvenstveno na Vicovu raspravu O konstantnosti filologije (drugi dio djela De constantia jurisprudentis), namjera nam je ukazati na liniju povijesnog razvoja koja se nalazi između dva glavna puta vikovske povijesti naroda – poganskog i židovskog. Naša studija omogućuje razmatranje Vicove znanosti kao rezultata interakcije različitih disciplinarnih palimpsesta i diskurzivnih krhotina, naprasno prekinute i nedovršene – uključujući i protestantsku egzegezute historiozofiju priscae sapientiae.Cet article se penche sur les façons dont Giambattista Vico approche la gigantologie érudite baroque et sur l’explication biblique de la confusion babylonienne des langues. En nous concentrant en premier lieu sur le débat Sur la constance de la philologie (seconde partie de
l’oeuvre De constantia jurisprudentis), notre intention est de mettre en avant la ligne de développement historique qui se situe entre deux voies de l’histoire vichienne des peuples – celle du peuple païen et du peuple juif. Notre étude nous permet d’examiner la science de Vico comme le résultat d’une interaction entre différents palimpsestes disciplinaires et fragments discursifs, subitement interrompus et non terminés, comportant également l’exégèse protestante et l’historiosophie de priscae sapientiae.Der Artikel befasst sich mit der Arten und Weisen, wie Giambattista Vico an die barocke gelehrte Gigantologie und den biblischen Bericht über die babylonische Sprachverwirrung herangeht. Indem wir Vicos Abhandlung Über die Beständigkeit der Philologie (zweiter Teil des Werks De constantia jurisprudentis) vorzugsweise zu unserem Fokus machen, setzen wir uns das Ziel, die Linie der historischen Entwicklung aufzuzeigen, die sich zwischen zwei Hauptwegen der vicoschen Völkergeschichte befindet – dem der Heiden und dem der Juden. Unsere Studie bietet die Gelegenheit, Vicos Wissenschaft als ein Ergebnis der Interaktion von unterschiedlichen disziplinären Palimpsesten und diskursiven Splittern zu betrachten, die abrupt abgebrochen und nicht bis zu Ende geschrieben sind – unter ihnen auch die protestantische Exegese oder die Historiosophie der prisca sapientia
FORMULATION OF DESIGN TASKS OF TOWED UNDERWATER VEHICLES CREATION FOR SHALLOW WATER AND AUTOMATION OF THEIR MOTION CONTROL
The towed underwater system is one of the fixed assets of the study of water areas. The effectiveness of its application depends on the characteristics laid at the design stage. The main task of the towed underwater vehicle (TUV) is the motion of technological equipment. Therefore, it is important to ensure the specified dynamic properties of the unit and automate the control of its motion. In the paper the typical forms of the unit are analyzed, the features of their control at small depths are set.
TUV control is carried out in conditions of uncertainty. Therefore, the design of an automatic control system (ACS) for its motion is proposed to be carried out using the appropriate synthesis method – the method of minimizing local functionals.
The control law contains integral components and, under the constraints of control actions, generates the problem of integral saturation. To eliminate the integral saturation in the work, the condition integration method is improved. On its basis, the control law and the structure of the controller of high dynamic accuracy of a second-order nonlinear object are synthesized. It is the basis for the synthesis of ACS controlled degrees of freedom of the underwater vehicle in conditions of uncertainty.
Usually TUVs contain two degrees of mobility. Translational motions of the unit are generated by changing its angular orientation. The paper synthesizes TUV controllers of pitch and roll based on the control law of the second order. Each control signal of the unit can affect both the roll and the pitch of the unit, which leads to decrease in the quality of control in general. To coordinate the work of controllers, a method is proposed, which is based on adjusting the initial conditions of the controller with greater error. On its basis, the automatic control system of the rotational motion of the unit is synthesized. It provides high dynamic precision control of two-dimensional rotational motion of the unit in uncertainty and is the basis for the ACS synthesis of its translational motion in space
A Shared Task on Bandit Learning for Machine Translation
We introduce and describe the results of a novel shared task on bandit
learning for machine translation. The task was organized jointly by Amazon and
Heidelberg University for the first time at the Second Conference on Machine
Translation (WMT 2017). The goal of the task is to encourage research on
learning machine translation from weak user feedback instead of human
references or post-edits. On each of a sequence of rounds, a machine
translation system is required to propose a translation for an input, and
receives a real-valued estimate of the quality of the proposed translation for
learning. This paper describes the shared task's learning and evaluation setup,
using services hosted on Amazon Web Services (AWS), the data and evaluation
metrics, and the results of various machine translation architectures and
learning protocols.Comment: Conference on Machine Translation (WMT) 201
Ad populum. Parlare alla pancia: retoriche del populismo in Europa
Recensiamo il libro Ad populum. Parlare alla pancia: retorica del populismo in Europa. Eds. Bruno Capaci e Giuditta Spassini. Bologna: I libri di Emil di Odoya srl., 2016. Stampa. Review of Ad populum. Parlare alla pancia: retorica del populismo in Europa. Eds. Bruno Capaci and Giuditta Spassini. Bologna: I libri di Emil di Odoya srl., 2016. Prin
Experimental and Computational Investigations of Phase Change Thermal Energy Storage Canisters
Two sets of experimental data are examined in this paper, ground and space experiments, for cylindrical canisters with thermal energy storage applications. A 2-D computational model was developed for unsteady heat transfer (conduction and radiation) with phase-change. The radiation heat transfer employed a finite volume method. The following was found in this study: (1) Ground Experiments: the convection heat transfer is equally important to that of the radiation heat transfer; radiation heat transfer in the liquid is found to be more significant than that in the void; including the radiation heat transfer in the liquid resulted in lower temperatures (about 15 K) and increased the melting time (about 10 min.); generally, most of the heat flow takes place in the radial direction. (2) Space Experiments: radiation heat transfer in the void is found to be more significant than that in the liquid (exactly the opposite to the Ground Experiments); accordingly, the location and size of the void affects the performance considerably; including the radiation heat transfer in the void resulted in lower temperatures (about 40 K)
The influence of natural magnetic field inhomogeneity areas of active geological fault on the dynamics of functional state of human brain
Tsaryovokokokshaysk Defensive Structures
The article deals with the data of archaeological studies of Tsaryovokokokokshaysk defensive structures. During archaeological studies the remains of posad fortifications – ostrog (wooden tortress), were found in the historical center of Yoshkar-Ola. The moat and the base of the poling wall were cut during archaeological excavations in 2008 and 2009 on the construction area of the cultural and historical complex "Tsaryovokokokshaysk Kremlin". Then a part of the moat, located to the south of the previously studied areas, was discovered during archaeological reconnaissance in 2013. Later in 2019, the moat and the ostrog's paling were investigated during archaeological excavations in the Kremlyovsky Housing Estate construction area south of the Tsaryovokokokokshaysky Kremlin. The results of archaeological studies of Tsaryovokokokokshaysk defensive structures allow the authors to clarify and supplement significantly archival sources and recreate the historical landscape of the city
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