Hybrid process algebra

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Index-2 hybrid DAE: a case study with well-posedness and numerical analysis

In this work, we study differential algebraic equations with constraints defined in a piece-wise manner using a conditional statement. Such models classically appear in systems where constraints can evolve in a very small time frame compared to the observed time scale. The use of conditional statements or hybrid automata are a powerful way to describe such systems and are, in general, well suited to simulation with event driven numerical schemes. However, such methods are often subject to chattering at mode switch in presence of sliding modes, and can result in Zeno behaviours. In contrast, the representation of such systems using differential inclusions and method from non-smooth dynamics are often closer to the physical theory but may be harder to interpret. Associated time-stepping numerical methods have been extensively used in mechanical modelling with success and then extended to other fields such as electronics and system biology. In a similar manner to the previous application of non-smooth methods to the simulation of piece-wise linear ODEs, we want to apply non-smooth numerical scheme to piece-wise linear DAEs. In particular, the study of a 2-D dynamical system of index-2 with a switching constraint using set-valued operators, is presented

An adaptive scheme for quantum state tomography

The process of inferring and reconstructing the state of a quantum system from the results of measurements, better known as quantum state tomography, constitutes a crucial task in the emerging field of quantum technologies. Today it is possible to experimentally control quantum systems containing tens of entangled qubits and perform measurements of arbitrary observables with great accuracy. However, in order to complete characterize an unknown $n$-qubit state, quantum state tomography requires a number of measurements which grows exponentially with $n$. A possible way to avoid this problem consists in performing an incomplete tomographic procedure able to provide a good estimate of the true state with few measurements. This thesis proposes a scheme for $n$-qubit state tomography which aims to improve the fidelity between the reconstructed state and the target state. In particular, the scheme identifies the next measurement to perform based on the knowledge already acquired from the previous measurements on the experimental prepared state. The performance of this scheme was finally analyzed by means of simulations of quantum state tomography with product measurements as well as with entangled measurements. In both cases one observes that the here proposed adaptive scheme significantly outperforms a standard scheme in terms of the fidelity of the reconstructed state

Computational Modeling and Design of Protein and Polymeric Nano-Assemblies

Advances in nanotechnology have the potential to utilize biological and polymeric systems to address fundamental scientific and societal issues, including molecular electronics and sensors, energy-relevant light harvesting, â??greenâ?? catalysis, and environmental cleanup. In many cases, synthesis and fabrication are well within grasp, but designing such systems requires simultaneous consideration of large numbers of degrees of freedom including structure, sequence, and functional properties. In the case of protein design, even simply considering amino acid identity scales exponentially with the protein length. This work utilizes computational techniques to develop a fundamental, molecularly detailed chemical and physical understanding to investigate and design such nano-assemblies. Throughout, we leverage a probabilistic computational design approach to guide the identification of protein sequences that fold to predetermined structures with targeted function. The statistical methodology is encapsulated in a computational design platform, recently reconstructed with improvements in speed and versatility, to estimate site-specific probabilities of residues through the optimization of an effective sequence free energy. This provides an information-rich perspective on the space of possible sequences which is able to harness the incorporation of new constraints that fit design objectives. The approach is applied to the design and modeling of protein systems incorporating non-biological cofactors, namely (i) an aggregation prone peptide assembly to bind uranyl and (ii) a protein construct to encapsulate a zinc porphyrin derivative with unique photo-physical properties. Additionally, molecular dynamics simulations are used to investigate purely synthetic assemblies of (iii) highly charged semiconducting polymers that wrap and disperse carbon nanotubes. Free energy calculations are used to explore the factors that lead to observed polymer-SWNT super-structures, elucidating well-defined helical structures; for chiral derivatives, the simulations corroborate a preference for helical handedness observed in TEM and AFM data. The techniques detailed herein, demonstrate how advances in computational chemistry allot greater control and specificity in the engineering of novel nano-materials and offer the potential to greatly advance applications of these systems

Modelado, simulación y control de un convertidor boost acoplado magnéticamente

This thesis covered the modeling, simulation as well as the design of a control law for a coupled inductor Boost converter. In particular, from the point of view of modeling, we focused on the use of averaged modeling and linear complementarity systems (LCS), in order to obtain the dynamic of a coupled inductor Boost converter, which works in discontinuous conduction mode (DCM). The analysis of the converter was performed assuming ideal voltage-current characteristics in the switch and the diodes. In addition, those models were validated through simulation with the model of the converter obtained from the simulation tool for electrical circuits Psim. The interest in researching this converter topology was mainly due to its high efficiency and high conversion rate without extreme duty cycle values. Moreover, from the point of view of control we have proposed a cascade control architecture. The inner loop is a sliding mode current control loop, while the outer one is a PI controller that tunes the current reference to regulate the output voltage to a reference value. The performance and the effectiveness of the feedback control was validated under the presence of load disturbances and input voltage variations through computer simulations by using the linear complementarity model as well as experimentally. Additionally from the linear complementarity model of the converter, it was performed an analysis of the ideal dynamic that takes place when occurs sliding motions in the converter and numerical stability analysis was also carried out.La presente tesis abarca el modelado, simulación y diseño de una ley de control para un convertidor Boost de inductancias acopladas. En particular, desde el punto de vista de modelado, nos enfocamos en las teoíıas de modelos promediados y sistemas lineales complementarios (LCS), para obtener la dinámica del convertidor Boost de inductancias acopladas, el cual trabaja en modo discontinuo de conducción (DCM). El análisis del convertidor se lleva a cabo asumiendo características ideales de tensión-corriente en el interruptor y los diodos. Además, los modelos obtenidos son validados mediante simulación con el modelo del convertidor proporcionado por la herramienta de simulación para circuitos eléctricos Psim. El interés en la topología de este convertidor se debe principalmente a su alta eficiencia y su elevada tasa de conversión sin necesidad de ciclos de trabajos extremos. Por otra parte, desde el punto de vista de control se propone una arquitectura de control en cascada. El lazo interno del control se compone de una estrategia de control no lineal, similar a la teoría de control en modo de deslizamiento, mientras que para el lazo externo se diseña un control de tipo PI. El principal objetivo del control diseñado es regular el voltaje de salida del convertidor a el valor de referencia deseado. La efectividad y desempeño del controlador diseñado es validada tanto en simulación como experimentalmente ante diferentes escenarios que incluyen perturbaciones en la carga y el voltaje de entrada. Adicionalmente a partir del modelo lineal complementario del convertidor, se lleva a cabo un análisis de la dinámica ideal de deslizamiento y un análisis numérico de la estabilidad cuando se tiene modo de deslizamiento

Quantum Nonlocality

This book presents the current views of leading physicists on the bizarre property of quantum theory: nonlocality. Einstein viewed this theory as “spooky action at a distance” which, together with randomness, resulted in him being unable to accept quantum theory. The contributions in the book describe, in detail, the bizarre aspects of nonlocality, such as Einstein–Podolsky–Rosen steering and quantum teleportation—a phenomenon which cannot be explained in the framework of classical physics, due its foundations in quantum entanglement. The contributions describe the role of nonlocality in the rapidly developing field of quantum information. Nonlocal quantum effects in various systems, from solid-state quantum devices to organic molecules in proteins, are discussed. The most surprising papers in this book challenge the concept of the nonlocality of Nature, and look for possible modifications, extensions, and new formulations—from retrocausality to novel types of multiple-world theories. These attempts have not yet been fully successful, but they provide hope for modifying quantum theory according to Einstein’s vision

Recent Advances in Linear and Nonlinear Optics

Sight is the dominant sense of mankind to apprehend the world at the earth scale and beyond the frontiers of the infinite, from the nanometer to the incommensurable. Primarily based on sunlight and natural and artificial light sources, optics has been the major companion of spectroscopy since scientific observation began. The invention of the laser in the early sixties has boosted optical spectroscopy through the intrinsic or specific symmetry electronic properties of materials at the multiscale (birefringence, nonlinear and photonic crystals), revealed by the ability to monitor light polarization inside or on the surface of designed objects. This Special Issue of Symmetry features articles and reviews that are of tremendous interest to scientists who study linear and nonlinear optics, all oriented around the common axis of symmetry. Contributions transverse the entire breadth of this field, including those concerning polarization and anisotropy within colloids of chromophores and metal/semiconducting nanoparticles probed by UV-visible and fluorescence spectroscopies; microscopic structures of liquid–liquid, liquid–gas, and liquid–solid interfaces; surface- and symmetry-specific optical techniques and simulations, including second-harmonic and sum-frequency generations, and surface-enhanced and coherent anti-Stokes Raman spectroscopies; orientation and chirality of bio-molecular interfaces; symmetry breaking in photochemistry; symmetric multipolar molecules; reversible electronic energy transfer within supramolecular systems; plasmonics; and light polarization effects in materials

Understanding Quantum Technologies 2022

Understanding Quantum Technologies 2022 is a creative-commons ebook that provides a unique 360 degrees overview of quantum technologies from science and technology to geopolitical and societal issues. It covers quantum physics history, quantum physics 101, gate-based quantum computing, quantum computing engineering (including quantum error corrections and quantum computing energetics), quantum computing hardware (all qubit types, including quantum annealing and quantum simulation paradigms, history, science, research, implementation and vendors), quantum enabling technologies (cryogenics, control electronics, photonics, components fabs, raw materials), quantum computing algorithms, software development tools and use cases, unconventional computing (potential alternatives to quantum and classical computing), quantum telecommunications and cryptography, quantum sensing, quantum technologies around the world, quantum technologies societal impact and even quantum fake sciences. The main audience are computer science engineers, developers and IT specialists as well as quantum scientists and students who want to acquire a global view of how quantum technologies work, and particularly quantum computing. This version is an extensive update to the 2021 edition published in October 2021.Comment: 1132 pages, 920 figures, Letter forma