RAPID CLOCK RECOVERY ALGORITHMS FOR DIGITAL MAGNETIC RECORDING AND DATA COMMUNICATIONS

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Liquid Crystal on Silicon Devices: Modeling and Advanced Spatial Light Modulation Applications

Liquid Crystal on Silicon (LCoS) has become one of the most widespread technologies for spatial light modulation in optics and photonics applications. These reflective microdisplays are composed of a high-performance silicon complementary metal oxide semiconductor (CMOS) backplane, which controls the light-modulating properties of the liquid crystal layer. State-of-the-art LCoS microdisplays may exhibit a very small pixel pitch (below 4 ?m), a very large number of pixels (resolutions larger than 4K), and high fill factors (larger than 90%). They modulate illumination sources covering the UV, visible, and far IR. LCoS are used not only as displays but also as polarization, amplitude, and phase-only spatial light modulators, where they achieve full phase modulation. Due to their excellent modulating properties and high degree of flexibility, they are found in all sorts of spatial light modulation applications, such as in LCOS-based display systems for augmented and virtual reality, true holographic displays, digital holography, diffractive optical elements, superresolution optical systems, beam-steering devices, holographic optical traps, and quantum optical computing. In order to fulfil the requirements in this extensive range of applications, specific models and characterization techniques are proposed. These devices may exhibit a number of degradation effects such as interpixel cross-talk and fringing field, and time flicker, which may also depend on the analog or digital backplane of the corresponding LCoS device. The use of appropriate characterization and compensation techniques is then necessary

Gravity Informed

Formulating a universally satisfactory theory of quantum gravity is a long-standing open problem in theoretical physics. Relatively recently, the use of techniques from quantum information has emerged as a powerful tool for analyzing phenomena that lie at the intersection of quantum theory and gravitation. This thesis describes several advances and novel proposals that were made regarding information theoretic aspects of quantum gravity in three broad areas: holography, cosmology, and the black hole information problem. Regarding holography, we first assess the differences between typical holographic states and fully random states. Next, we show that determining Ryu-Takayanagi surfaces in AdS3/CFT2 is computationally easy from a complexity-theoretic standpoint. Finally, we identify precise consistency conditions that constrain the validity of an early tensor network model for the AdS/CFT correspondence that uses the Multiscale Entanglement Renormalization Ansatz (MERA). Regarding cosmology, we propose an alternative interpretation of the MERA as a discretization of de Sitter spacetime. Next, we return to holographic ideas and show that an appropriately-defined Generalized Second Law implies a cosmic no-hair theorem for certain classes of cosmological spacetimes. Finally, we advance an information-theoretic proposal for calculating the signature of a quantum gravity-motivated, fully covariant, natural ultraviolet cutoff in the spectrum of inflationary perturbations. Regarding the black hole information problem, we begin by exhibiting a simple protocol which, under highly specific circumstances, allows one to retrieve a single qubit from a black hole. Next, we propose an operational resolution of the black hole information problem in which observers who enter the black hole could never detect an inconsistency between their experiences and quantum mechanics due to the finite amount of time available before reaching the central singularity. Finally, we discuss a proposal to understand the emergence of an ensemble of definite geometries during the process of black hole evaporation as a decoherence process, as well as its implications for the black hole information problem.</p

Multimedia

The nowadays ubiquitous and effortless digital data capture and processing capabilities offered by the majority of devices, lead to an unprecedented penetration of multimedia content in our everyday life. To make the most of this phenomenon, the rapidly increasing volume and usage of digitised content requires constant re-evaluation and adaptation of multimedia methodologies, in order to meet the relentless change of requirements from both the user and system perspectives. Advances in Multimedia provides readers with an overview of the ever-growing field of multimedia by bringing together various research studies and surveys from different subfields that point out such important aspects. Some of the main topics that this book deals with include: multimedia management in peer-to-peer structures & wireless networks, security characteristics in multimedia, semantic gap bridging for multimedia content and novel multimedia applications

Computational and Spectroscopic Investigations of Intermolecular Interactions in Clusters

In this thesis, the study of intermolecular interactions within cluster systems is presented. Covalently and non-covalently bound clusters possess oftentimes unique and unexpected properties which can be tuned by adjustment of size, composition, and geometry to target desired properties for use in nanotechnologies. Additionally, clusters present a computationally tractable model of bulk systems such as reactive sites on bulk heterogeneous catalysts. Infrared spectra have been collected of various clusters and theoretical computations have been conducted to interpret spectra and provide predictions for other properties to guide future works. Investigations of the forces binding cluster species together are conducted to provide insight into the fundamental underpinning of molecular properties with applications in the field of nanomaterial design. A variety of clusters have been studied here. Computational studies of size-dependency in nitrous oxide reactions with rhodium sulphide clusters have been conducted. Barriers to competing N2O desorption and decomposition have been ascertained and compared with and without thermal corrections. Inclusion of the sulphur atom is found to alter which reaction pathway is preferred, as seen by comparison with analogous studies on pure rhodium clusters. Infrared multiple photon dissociation (IRMPD) spectroscopy is utilized to probe the additional clusters; a series of palladium coordination complexes and a series of clusters containing icosahedral [B12X12]2─ (X = H, halogen) cages complexed with a cationic transition metal atom, a cationic amine, or a neutral polar cyclohexane-based compound. This IRMPD technique successfully produced infrared spectra for these species in the gas phase and unique properties were observed for each cluster upon IR induced dissociation. Density functional theory calculations determined geometries, dissociation thresholds, and interpreted IR spectra. Additional theoretical tools quantified molecular orbital interactions and topographical parameters of the electron density

Recent Advances in Signal Processing

The signal processing task is a very critical issue in the majority of new technological inventions and challenges in a variety of applications in both science and engineering fields. Classical signal processing techniques have largely worked with mathematical models that are linear, local, stationary, and Gaussian. They have always favored closed-form tractability over real-world accuracy. These constraints were imposed by the lack of powerful computing tools. During the last few decades, signal processing theories, developments, and applications have matured rapidly and now include tools from many areas of mathematics, computer science, physics, and engineering. This book is targeted primarily toward both students and researchers who want to be exposed to a wide variety of signal processing techniques and algorithms. It includes 27 chapters that can be categorized into five different areas depending on the application at hand. These five categories are ordered to address image processing, speech processing, communication systems, time-series analysis, and educational packages respectively. The book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity