An asynchronous circuit design language system

This paper presents a system for specifying the behavior of asynchronous sequential circuits. The system consists of a special purpose Asynchronous Circuit Design Language (ACDL), a translator and a flow table generation algorithm. The language includes many special features which permit quick and precise specification of terminal behavior. It is best suited for problems originating from a word description of the circuit\u27s operation. The translator is written with the XPL Translator Writing System and is a syntax-directed compilation method. From the translated ACDL specifications, the flow table algorithm generates a primitive flow table which is the required input for the conventional synthesis procedures of asynchronous sequential circuits. A thorough description of the translator and flow table programs is given in the Appendices. In addition a number of example problems illustrating the use of ACDL are provided --Abstract, page ii

Energy-Efficient Algorithms

We initiate the systematic study of the energy complexity of algorithms (in addition to time and space complexity) based on Landauer's Principle in physics, which gives a lower bound on the amount of energy a system must dissipate if it destroys information. We propose energy-aware variations of three standard models of computation: circuit RAM, word RAM, and transdichotomous RAM. On top of these models, we build familiar high-level primitives such as control logic, memory allocation, and garbage collection with zero energy complexity and only constant-factor overheads in space and time complexity, enabling simple expression of energy-efficient algorithms. We analyze several classic algorithms in our models and develop low-energy variations: comparison sort, insertion sort, counting sort, breadth-first search, Bellman-Ford, Floyd-Warshall, matrix all-pairs shortest paths, AVL trees, binary heaps, and dynamic arrays. We explore the time/space/energy trade-off and develop several general techniques for analyzing algorithms and reducing their energy complexity. These results lay a theoretical foundation for a new field of semi-reversible computing and provide a new framework for the investigation of algorithms.Comment: 40 pages, 8 pdf figures, full version of work published in ITCS 201

In-flight maintenance study Final report

Sample system analysis, MF requirements, redesign, and packaging desig

A fast-initializing digital equalizer with on-line tracking for data communications

A theory is developed for a digital equalizer for use in reducing intersymbol interference (ISI) on high speed data communications channels. The equalizer is initialized with a single isolated transmitter pulse, provided the signal-to-noise ratio (SNR) is not unusually low, then switches to a decision directed, on-line mode of operation that allows tracking of channel variations. Conditions for optimal tap-gain settings are obtained first for a transversal equalizer structure by using a mean squared error (MSE) criterion, a first order gradient algorithm to determine the adjustable equalizer tap-gains, and a sequence of isolated initializing pulses. Since the rate of tap-gain convergence depends on the eigenvalues of a channel output correlation matrix, convergence can be improved by making a linear transformation on to obtain a new correlation matrix

Nonholonomic motion planning: steering using sinusoids

Methods for steering systems with nonholonomic constraints between arbitrary configurations are investigated. Suboptimal trajectories are derived for systems that are not in canonical form. Systems in which it takes more than one level of bracketing to achieve controllability are considered. The trajectories use sinusoids at integrally related frequencies to achieve motion at a given bracketing level. A class of systems that can be steered using sinusoids (claimed systems) is defined. Conditions under which a class of two-input systems can be converted into this form are given

Computer aided design of substation switching schemes

Every switching operation in a power substation must be executed after proper evaluation of its consequence. Often, switching actions for various operating conditions and contingencies are pre determined by using the control engineer's knowledge and previous experience. When the need arises, either a computer or an operator carries out these actions. However, it is difficult for an operator to know all the operating conditions and contingencies in advance. An on line decision making tool can provide an operator with the most appropriate switching decisions for the present system configuration and system state so the continuity and quality of power supply can be maintained by implementing those switching decisions. Since the circuit configuration varies from one substation to another, such decision-making tools developed for one substation may not be applicable to another substation. This thesis presents a technique to design digital computer based substation switching schemes. The technique is applicable to all practical substations. The rules of interlocking and sequence switching used by the schemes are generalized and are not based upon a particular substation configuration. While being applicable to all substations, these schemes also ensure the most appropriate switching operations with minimum operator intervention. The switching schemes ensure the safety of the system before making any switching action. They assist human operators in the evaluation of abnormal circumstances and are easy to integrate with other monitoring, control and protection systems. A software application for developing switching schemes for substations called SSP was developed by using the techniques presented in this thesis. Switching schemes were developed for eight substations by using the semi-automated design tools provided with SSP. The switching schemes were then tested for their correct operation. Results of the tests showed that the technique developed by the work presented in this thesis can provide appropriate switching scheme for a substation of any practical configuration