A software-defined receiver for laser communications using a GPU

This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018Cataloged from PDF version of thesis.Includes bibliographical references (pages 43-46).Laser commiunication systems provide a high data rate, power efficient communication solution for small satellites and deep space missions. One challenge that limits the widespread use of laser communication systems is the lack of accessible, low-complexity receiver electronics and software implementations. Graphics Processing Units (GPUs) can reduce the complexity in receiver design since GPUs require less specialized knowledge and can enable faster development times than Field Programmnable Cate Array (FPGA) implementations, while still retaining comparable data throughputs via parallelization. This thesis explores the use of a Graphics Processing Unit (GPU) as the sole computational unit for the signal processing algorithms involved in laser conmnunications.by Joseph Matthew Kusters.M. Eng.M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Scienc

Wolpert, Chaitin and Wittgenstein on impossibility, incompleteness, the liar paradox, theism, the limits of computation, a non-quantum mechanical uncertainty principle and the universe as computer—the ultimate theorem in Turing Machine Theory (revised 2019)

I have read many recent discussions of the limits of computation and the universe as computer, hoping to find some comments on the amazing work of polymath physicist and decision theorist David Wolpert but have not found a single citation and so I present this very brief summary. Wolpert proved some stunning impossibility or incompleteness theorems (1992 to 2008-see arxiv dot org) on the limits to inference (computation) that are so general they are independent of the device doing the computation, and even independent of the laws of physics, so they apply across computers, physics, and human behavior. They make use of Cantor's diagonalization, the liar paradox and worldlines to provide what may be the ultimate theorem in Turing Machine Theory, and seemingly provide insights into impossibility, incompleteness, the limits of computation, and the universe as computer, in all possible universes and all beings or mechanisms, generating, among other things, a non- quantum mechanical uncertainty principle and a proof of monotheism. There are obvious connections to the classic work of Chaitin, Solomonoff, Komolgarov and Wittgenstein and to the notion that no program (and thus no device) can generate a sequence (or device) with greater complexity than it possesses. One might say this body of work implies atheism since there cannot be any entity more complex than the physical universe and from the Wittgensteinian viewpoint, ‘more complex’ is meaningless (has no conditions of satisfaction, i.e., truth-maker or test). Even a ‘God’ (i.e., a ‘device’with limitless time/space and energy) cannot determine whether a given ‘number’ is ‘random’, nor find a certain way to show that a given ‘formula’, ‘theorem’ or ‘sentence’ or ‘device’ (all these being complex language games) is part of a particular ‘system’. Those wishing a comprehensive up to date framework for human behavior from the modern two systems view may consult my book ‘The Logical Structure of Philosophy, Psychology, Mind and Language in Ludwig Wittgenstein and John Searle’ 2nd ed (2019). Those interested in more of my writings may see ‘Talking Monkeys--Philosophy, Psychology, Science, Religion and Politics on a Doomed Planet--Articles and Reviews 2006-2019 2nd ed (2019) and Suicidal Utopian Delusions in the 21st Century 4th ed (2019

A Modular Command and Data Handling System Concept for Small Satellites

The increasing demand for high-performance computer systems on board space missions applications, such as artificial intelligence and machine learning, are drivers of the need for higher on-board command and data handling specifications. Consequently, a modular Command and Data Handling Subsystem (CDHS) is required in order to manage the complexity of future CDHS hardware. Some systems have applied a similar approach; however, they either focus on large scale satellites or have a certain level of complexity that limits their usage by learners. This paper proposes a modular Command and Data Handling System that includes several layers providing more flexibility in design at a low cost. The system also potentially allows the integration of CDHS initially used in CubeSats in larger-scale satellites. Also, Through this paper highlights the interfacing options used in the proposed design, including the regular command and data interfaces, wireless command and data interfaces, high-speed data interfaces, and power interfaces. The results validate the usefulness and potential of the proposed system as a modular Command and Data Handling System that can be used in future missions. It also opens the door for further development, allowing the low-cost development of Command and Data Handling Systems

Reconfigurable Asynchronous Logic Automata (RALA)

Computer science has served to insulate programs and programmers from knowledge of the underlying mechanisms used to manipulate information, however this fiction is increasingly hard to maintain as computing devices decrease in size and systems increase in complexity. Manifestations of these limits appearing in computers include scaling issues in interconnect, dissipation, and coding. Reconfigurable Asynchronous Logic Automata (RALA) is an alternative formulation of computation that seeks to align logical and physical descriptions by exposing rather than hiding this underlying reality. Instead of physical units being represented in computer programs only as abstract symbols, RALA is based on a lattice of cells that asynchronously pass state tokens corresponding to physical resources. We introduce the design of RALA, review its relationships to its many progenitors, and discuss its benefits, implementation, programming, and extensions.National Science Foundation (U.S.) Center for Bits and AtomsUnited States. Army Research Office (Grant number W911NF-08-1-0254)United States. Army Research Office (Grant number W911NF-09-1-0542

Urban Simulation Models: Contributions as Analysis-Methodology in a Project of Urban Renewal

The recent urban transformations produced in cities indicate the need to propose new theoretical and methodological approaches in physical planning. Based on the idea of complexity, it is required to integrate, in the analysis, multiplicity of interrelated factors involved in urban development,moreover, to develop planning tools that can incorporate variables not initially considered (for example when the norms were sanctioned) and instruments that would provide assessment alternatives to planning decisions in real time. The simulation models are suggested as tools to detect the elements, relationships and the dynamics in a simplified form that allow experiencing on the results. That is to say, a theoretical position on to a computer model is translated to investigate (in an experimental way) possible solutions derived from manipulating the variables, before the phenomenon is materialized. In the case of urban planning, this condition is of particular relevance, given the importance to anticipate unwanted effects in the intervention context that may arise when urban projects are built. The paper evaluates the application of a simulation methodology,based on the dynamics of systems and the application of software that can anticipate the effects of certain decisions in an urban renewal project in the city of Córdoba, Argentina. It applies the General Systems Theory that is a contribution to the notion of complex thought and is trans-disciplinary. Based on the idea of complex and multidimensional city, the effects of a real estate development are analyzed and conclusions on the limits and possibilities of using this tool during the processes of urban management are provided.Fil: Marengo, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño. Instituto de Investigación de la Vivienda; Argentin

Validation of a Scaled Plane Strain Hypervelocity Gouging Model

The phenomenon of high speed impact is of great interest to the Air Force of Scientific Research and the Air Force Research Laboratory\u27s Holloman High Speed test track. Rocket sled tests at the facility frequently are limited to velocities lower than actually attainable due to damage to the rail in the form of gouges. Direct observation of the gouging phenomenon is not currently possible. This leaves computational modeling as the only means to study the phenomenon. A computer model has previously been used to model the development of gouging at the Holloman High Speed Test Track. However, this model has not been experimentally verifiable due to its complexity. This research is primarily concerned with comparing experiment and analysis of a simplified gouging model. This simplified gouging experiment utilized a 30 mm powder gun to shoot cylindrical projectiles at a target at oblique angles. Computer simulations of the event overestimated penetration depths by 13 to 29 percent, which is well within acceptable limits. Using dimensional analysis, the simplified gouging model was scaled up to an equivalent sled system model. While this equivalent system does not actually exist, it does give reasonable estimates for similar sized systems