A guided tour of asynchronous cellular automata

Research on asynchronous cellular automata has received a great amount of attention these last years and has turned to a thriving field. We survey the recent research that has been carried out on this topic and present a wide state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat

Programmable surfaces

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 131-135).Robotic vehicles walk on legs, roll on wheels, are pulled by tracks, pushed by propellers, lifted by wings, and steered by rudders. All of these systems share the common character of momentum transport across their surfaces. These existing approaches rely on bulk response among the fluids and solids. They are often not finely controllable and complex approaches suffer from manufacturing and practical operational challenges. In contrast I present a study of a dynamic, programmable interface between the surface and its surrounding fluids. This research explores a synthetic hydrodynamic regime, using a programmable surface to dynamically alter the flow around an object. Recent advances in distributed computing and communications, actuator integration and batch fabrication, make it feasible to create intelligent active surfaces, with significant implications for improving energy efficiency, recovering energy, introducing novel form factors and control laws, and reducing noise signatures. My approach applies ideas from programmable matter to surfaces rather than volumes. The project is based on covering surfaces with large arrays of small cells that can each compute, communicate, and generate shear or normal forces. The basic element is a cell that can be joined in arrays to tile a surface, each containing a processor, connections for power and communications, and means to control the local wall velocity The cell size is determined by the characteristic length scale of the flow field ranging from millimeters to centimeters to match the desired motion and fluidic system. Because boundary layer effects are significant across fluid states from aerodynamics to hydrodynamics to rheology, the possible implications of active control of the boundary layer are correspondingly far reaching, with applications from transportation to energy generation to building air handling. This thesis presents a feasibility study, evaluating current manufacturing, processing, materials, and technologies capabilities to realize programmable surfaces.by Amy Sun.Ph.D

Aeronautical engineering: A continuing bibliography with indexes (supplement 295)

This bibliography lists 581 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in Sep. 1993. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Design of a Reconfigurable Pulsed Quad-Cell for Cellular-Automata-Based Conformal Computing

This paper presents the design of a reconfigurable asynchronous unit, called the pulsed quad-cell (PQ-cell), for conformal computing. The conformal computing vision is to create computational materials that can conform to the physical and computational needs of an application. PQ-cells, like cellular automata, are assembled into arrays with nearest neighbor communication and are capable of general computation. They operate asynchronously to minimize power consumption and to allow sealing without the limitations imposed by a global clock. Cell operations are stimulated by pulses which use two wires to encode a data bit. Cells are individually reconfirgurable to perform logic, move and store information, and coordinate parallel activity. The PQ-cell design targets a 0.25 μm CMOS technology. Simulation results show that a PQ-cell, when pulsed at 1.3 GHz, consumes 16.9 pJ per operation. Examples of self-timed multi-cell structures include a 98 MHz ring oscillator and a 385 MHz pipeline

NASA patent abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 46)

A subject index is provided for over 5600 patents and patent applications for the period May 1969 through December 1994. Additional indexes list personal authors, corporate authors, contract numbers, NASA case numbers, U.S. patent class numbers, U.S. patent numbers, and NASA accession numbers

Naval Postgraduate School Catalog 2015

Approved for public release; distribution is unlimited