Simultaneous Firing of Production Rules on Tree Structured Machines

This paper describes a method to realize the simultaneous firing of production rules on tree c structured machines. We propose a simultaneous firing mechanism consisting of global, communication and global synchronization between subtrees. We also proposes hierarchical decomposition algorithm for production systems which maximizes total throughput by satisfying two requirements, Le. Maximizing parallel executability and minimizing global communication

Research in the effective implementation of guidance computers with large scale arrays Interim report

Functional logic character implementation in breadboard design of NASA modular compute

An Experimental Microarchitecture for a Superconducting Quantum Processor

Quantum computers promise to solve certain problems that are intractable for classical computers, such as factoring large numbers and simulating quantum systems. To date, research in quantum computer engineering has focused primarily at opposite ends of the required system stack: devising high-level programming languages and compilers to describe and optimize quantum algorithms, and building reliable low-level quantum hardware. Relatively little attention has been given to using the compiler output to fully control the operations on experimental quantum processors. Bridging this gap, we propose and build a prototype of a flexible control microarchitecture supporting quantum-classical mixed code for a superconducting quantum processor. The microarchitecture is based on three core elements: (i) a codeword-based event control scheme, (ii) queue-based precise event timing control, and (iii) a flexible multilevel instruction decoding mechanism for control. We design a set of quantum microinstructions that allows flexible control of quantum operations with precise timing. We demonstrate the microarchitecture and microinstruction set by performing a standard gate-characterization experiment on a transmon qubit.Comment: 13 pages including reference. 9 figure

Aerospace Applications of Microprocessors

An assessment of the state of microprocessor applications is presented. Current and future requirements and associated technological advances which allow effective exploitation in aerospace applications are discussed

From Parallel Programs to Customized Parallel Processors

The need for fast time to market of new embedded processor-based designs calls for a rapid design methodology of the included processors. The call for such a methodology is even more emphasized in the context of so called soft cores targeted to reconfigurable fabrics where per-design processor customization is commonplace. The C language has been commonly used as an input to hardware/software co-design flows. However, as C is a sequential language, its potential to generate parallel operations to utilize naturally parallel hardware constructs is far from optimal, leading to a customized processor design space with limited parallel resource scalability. In contrast, when utilizing a parallel programming language as an input, a wider processor design space can be explored to produce customized processors with varying degrees of utilized parallelism. This Thesis proposes a novel Multicore Application-Specific Instruction Set Processor (MCASIP) co-design methodology that exploits parallel programming languages as the application input format. In the methodology, the designer can explicitly capture the parallelism of the algorithm and exploit specialized instructions using a parallel programming language in contrast to being on the mercy of the compiler or the hardware to extract the parallelism from a sequential input. The Thesis proposes a multicore processor template based on the Transport Triggered Architecture, compiler techniques involved in static parallelization of computation kernels with barriers and a datapath integrated hardware accelerator for low overhead software synchronization implementation. These contributions enable scaling the customized processors both at the instruction and task levels to efficiently exploit the parallelism in the input program up to the implementation constraints such as the memory bandwidth or the chip area. The different contributions are validated with case studies, comparisons and design examples

Information management system study results. Volume 1: IMS study results

The information management system (IMS) special emphasis task was performed as an adjunct to the modular space station study, with the objective of providing extended depth of analysis and design in selected key areas of the information management system. Specific objectives included: (1) in-depth studies of IMS requirements and design approaches; (2) design and fabricate breadboard hardware for demonstration and verification of design concepts; (3) provide a technological base to identify potential design problems and influence long range planning (4) develop hardware and techniques to permit long duration, low cost, manned space operations; (5) support SR&T areas where techniques or equipment are considered inadequate; and (6) permit an overall understanding of the IMS as an integrated component of the space station

Process modelling for information system description

My previous experiences and some preliminary studies of the relevant technical literature allowed me to identify several reasons for which the current state of the database theory seemed unsatisfactory and required further research. These reasons included: insufficient formalism of data semantics, misinterpretation of NULL values, inconsistencies in the concept of the universal relation, certain ambiguities in domain definition, and inadequate representation of facts and constraints. The commonly accepted ’sequentiality’ principle in most of the current system design methodologies imposes strong restrictions on the processes that a target system is composed of. They must be algorithmic and must not be interrupted during execution; neither may they have any parallel subprocesses as their own components. This principle can no longer be considered acceptable. In very many existing systems multiple processors perform many concurrent actions that can interact with each other. The overconcentration on data models is another disadvantage of the majority of system design methods. Many techniques pay little (or no) attention to process definition. They assume that the model of the Real World consists only of data elements and relationships among them. However, the way the processes are related to each other (in terms of precedence relation) may have considerable impact on the data model. It has been assumed that the Real World is discretisable, i.e. it may be modelled by a structure of objects. The word object is to be interpreted in a wide sense so it can mean anything within the boundaries of this part of the Real World that is to be represented in the target system. An object may then denote a fact or a physical or abstract entity, or relationships between any of these, or relationships between relationships, or even a still more complex structure. The fundamental hypothesis was formulated stating the necessity of considering the three aspects of modelling - syntax, semantics and behaviour, and these to be considered integrally. A syntactic representation of an object within a target system is called a construct A construct which cannot be decomposed further (either syntactically or semantically) is defined to be an atom. Any construct is a result of the following production rules: construct ::= atom I function construct; function ::= atom I construct. This syntax forms a sentential notation. The sentential notation allows for extensive use of denotational semantics. The meaning of a construct may be defined as a function mapping from a set of syntactic constructs to the appropriate semantic domains; these in turn appear to be sets of functions since a construct may have a meaning in more than one class of objects. Because of its functional form the meaning of a construct may be derived from the meaning of its components. The issue of system behaviour needed further investigation and a revision of the conventional model of computing. The sequentiality principle has been rejected, concurrency being regarded as a natural property of processes. A postulate has been formulated that any potential parallelism should be constructively used for data/process design and that the process structure would affect the data model. An important distinction has been made between a process declaration - considered as a form of data or an abstraction of knowledge - and a process application that corresponds to a physical action performed by a processor, according to a specific process declaration. In principle, a process may be applied to any construct - including its own representation - and it is a matter of semantics to state whether or not it is sensible to do so. The process application mechanism has been explained in terms of formal systems theory by introducing an abstract machine with two input and two output types of channels. The system behaviour has been described by defining a process calculus. It is based on logical and functional properties of a discrete time model and provides a means to handle expressions composed of process-variables connected by logical functors. Basic terms of the calculus are: constructs and operations (equivalence, approximation, precedence, incidence, free-parallelism, strict-parallelism). Certain properties of these operations (e.g. associativity or transitivity) allow for handling large expressions. Rules for decomposing/integrating process applications, analogous in some sense to those forming the basis for structured programming, have been derived

Evaluation of the PlayStation 2 as a cluster computing node

Cluster computing is currently a popular, cost-effective solution to the increasing computational demands of many applications in scientific computing and image processing. A cluster computer is comprised of several networked computers known as nodes. Since the goal of cluster computing is to provide a cost-effective means to processing computationally demanding applications, nodes that can be obtained at a low price with minimal performance tradeoff are always attractive. Presently, the most common cluster computers are comprised of networks of workstations constructed from commodity components. Recent trends have shown that computers being developed and deployed for purposes other than traditional personal computers or workstations have presented new candidates for cluster computing nodes. The new computing node candidates being considered may provide a competitive and even less expensive alternative to the cluster computing nodes being used today. Machines such as video game consoles, whose prices are kept extremely low due to intense marketplace competition, are a prime example of such machines. The Sony PlayStation 2, in particular, provides the user with low-level hardware devices that are often found in more expensive machines. This work presents and evaluation of the PlayStation 2 video game console as a cluster computing node for scientific and image processing applications. From this evaluation, a determination is made as to whether the PlayStation 2 is a viable alternative to the cluster computing nodes being used today

Control, guidance, and navigation for advanced manned missions. Volume 1 - Systems Final report

Advanced computer, radiation, and inertial subsystem guidance and navigation requirements of interplanetary manned space flight mission