Three hierarchies of transducers

Composition of top-down tree transducers yields a proper hierarchy of transductions and of output languages. The same is true for ETOL systems (viewed as transducers) and for two-way generalized sequential machines

Controllability of sequential machines

A sequential machine is said to be k-controllable if there exists a minimum integer k such that every state transition can be achieved by an input sequence of length k. In this paper properties of controllable sequential machines are discussed. The main results are as follows: (1) An efficient procedure for controllability test is given. (2) It is shown that every uncontrollable strongly connected machine has an autonomous component machine. (3) The upper bound of k in a controllable machine containing a loop of length l is given. (4) The upper and lower bounds of k in k-controllable machines are shown. (5) It is shown that any sequential machine can be realized by a controllable or uncontrollable machine

Structure theory for the realization of finite state automata Final report, 1 Nov. 1966 - 31 Oct. 1968

Feedback and inessential errors in sequential machines, realization of sequential machines, and logic hazards in threshold gate network

Exact Essential-Hazard-Free State Minimization of Incompletely Specified Asynchronous Sequential Machines

To insure correct dynamic behaviour of asynchronous sequential machines, hazards must be eliminated for they may cause malfunctions of the whole system. However, Hazard-free state minimization has received almost no prior attention in the literature. This paper describes an exact algorithm for essential-hazard-free state minimization of incompletely specified asynchronous sequential machines. Novel techniques for the elimination of apparent and potential essential hazards are proposed and exploited in our algorithm. The algorithm has been implemented and applied to over a dozen asynchronous sequential machines. Results are compared with results of non-essential-hazard-free method SIS. Most of the tested cases can be reduced to essential hazard free flow tables

Fault detection on sequential machines

This paper presents an algorithm for deriving an optimum test sequence for detecting faults in a synchronous machine. In this study, the flow table is used as a tool to generate the fault detection tests. The fault stuck-at-1 (or stuck-at-0 ) is said to be present when a permanent signal valued 1 (or 0) appears on a component of the machine. Only single faults are treated . The result of the procedure is one or more test sequences guaranteed to detect a set of faults (Fp). First, sequential machines with feedback lines as memory elements are considered . Then the memory elements are changed to R-S flip-flops. Finally, several suggestions for further work are made --Abstract, Page ii

Time-varying linear sequential machines. I

AbstractA time-varying linear sequential machine (TVLSM) model is considered which hasthe property that the dimensionality of the system is a function of time. General response formulas for TVLSM's are developed and an effective procedure is described for minimizing such systems with respect to dimensionality. It is shown that every TVLSM has a minimal form unique up to isomorphism. “Equivalent” fixed sequential machines, referred to as “fixed analogs”, may be constructed for certain periodic TVLSM's

Sorting Integers on the AP1000

Sorting is one of the classic problems of computer science. Whilst well understood on sequential machines, the diversity of architectures amongst parallel systems means that algorithms do not perform uniformly on all platforms. This document describes the implementation of a radix based algorithm for sorting positive integers on a Fujitsu AP1000 Supercomputer, which was constructed as an entry in the Joint Symposium on Parallel Processing (JSPP) 1994 Parallel Software Contest (PSC94). Brief consideration is also given to a full radix sort conducted in parallel across the machine.Comment: 1994 Project Report, 23 page

DYNAMIC PARAMETERS CERTIFICATION FOR ASYNCHRONOUS FSM

Although the use of asynchronous sequential machines is confined to solving specific problems where synchronous machines are non-applicable or perform poorly, we can encounter many situations where we definitely wish to exploit their benefits (high speed, low resolution time,…, etc.). However considering the fact that these asynchronous sequential machines are integrated with synchronous machines, a minimal output signal width must be provided in order to obtain the needed control capability. A control method for the output signal width is presented and experimental results confirm its validity. This method represents in fact a hybrid asynchronous model