Synthesis Of Automata Research Articles

A Passive Online Technique for Learning Hybrid Automata from Input/Output Traces

Specification synthesis is the process of deriving a model from the input-output traces of a system. It is used extensively in test design, reverse engineering, and system identification. One type of the resulting artifact of this process for cyber-physical systems is hybrid automata. They are intuitive, precise, tool independent, and at a high level of abstraction, and can model systems with both discrete and continuous variables. In this article, we propose a new technique for synthesizing hybrid automaton from the input-output traces of a non-linear cyber-physical system. Similarity detection in non-linear behaviors is the main challenge for extracting such models. We address this problem by utilizing the Dynamic Time Warping technique. Our approach is passive, meaning that it does not need interaction with the system during automata synthesis from the logged traces; and online, which means that each input/output trace is used only once in the procedure. In other words, each new trace can be used to improve the already synthesized automaton. We evaluated our algorithm in one industrial and two simulated case studies. The accuracy of the derived automata shows promising results.

Оптимізація схеми автомата Мілі в базисі FPGA

Introduction. The ubiquitous penetration of digital systems into all spheres of human activity has made obvious the desire to reduce hardware costs. If for the implementation of combinational circuits there are standard solutions used in various CAD systems, then for many types of accumulating blocks, which include control devices (CU), there are no standard library solutions. CU circuits, which are a sequential circuit, must be designed first each time because, as a rule, these circuits differ in an irregular structure and a complex interconnection system. The characteristics of the control device have a significant impact on the quality of the digital system, and therefore the issue of designing a control device is a responsible process that, as a rule, requires solving the problem of reducing hardware costs. Methods for solving this problem depend on the features of both the architecture of the control device and the elemental basis. Purpose. The main goal of this work is to reduce hardware costs and power consumption of control devices of digital systems by taking into account features of an element base of the control device and rational organization of micro-command addressing. FPGA (field-programmable logic array) microcircuits, widely used for the implementation of modern digital systems, were chosen as an elementary basis. Methods. To evaluate the effectiveness of solving the problem, we used the methods of set theory, synthesis of automata, and software simulation using Xilinx Vivado CAD. Results. The paper proposes a method for reducing hardware costs in the microprogram Mealy automaton (MPA) scheme implemented on an EMB and LUT basis. The method is based on the use of EMB to implement the logical condition replacement block. It is proposed to implement a part of the output signals (micro-operations) on EMB. The applicability conditions for this approach are shown. An example of the synthesis of MPA using the proposed method is given. All stages of the synthesis are analyzed in detail. Some alternative solutions are proposed and the conditions for their use are shown. Conclusion. Studies have shown that when using one EMB block, our method gives a gain in the number of LUT elements. Comparisons were made with schemes obtained using the Auto, One-hot, and Sequential methods of the Vivado system.

Optimization of a Composition Microprogram Control Unit with Elementary Circuits

Introduction. The control unit coordinating interaction of all other blocks of a digital system is one of the central blocks and is a sequential circuit. As a rule, when synthesizing control unit circuits, the problem arises of reducing hardware costs. Methods for solving this problem depend on features of both the architecture of the control unit and the elemental basis. Purpose. The main goal of this work is to reduce hardware costs and power consumption of control units of digital systems by taking into account features of the element base of the control unit and rational organization of addressing microinstructions. FPGA (field-programmable logic array) microcircuits, widely used for the implementation of modern digital systems, were chosen as an elementary basis. Methods. Methods of set theory, synthesis of automata, and software modeling as well as the library of standard automata and FPGA Virtex-7 from Xilinx were used for assessment the effectiveness of solving the problem. Results. The paper proposes a method for optimizing the circuit of the microinstruction addressing unit based on splitting the set of outputs of elementary linear operator circuits, which is based on the idea of double coding of states. The proposed method, under certain conditions, makes it possible to reduce the number of levels in the microinstruction addressing circuit to two. Conclusion. Studies have shown that double coding of states can increase performance, reduce hardware costs (the number of LUTs and their interconnections) and power consumption in Mealy’s circuitry. Based on these results, it can be expected that, with the number of conditions exceeding the number of LUT inputs, the proposed approach will improve the characteristics of the composition microprogram control unit in comparison with the equivalent control unit U1.

A sufficient condition to polynomially compute a minimum separating DFA

The computation of a minimal separating automaton (MSA) for regular languages has been studied from many different points of view, from synthesis of automata or Grammatical Inference to the minimization of incompletely specified machines or Compositional Verification. In the general case, the problem is NP-complete, but this drawback does not prevent the problem from having a real application in the above-mentioned fields. In this paper, we propose a sufficient condition that guarantees that the computation of the MSA can be carried out with polynomial time complexity.

Games with delay for automaton synthesis

Games with delay for automaton synthesis

More on (2,2)-separating systems

The theory of separating systems has been applied in different areas of science and technology such as automata synthesis, technical diagnosis, and authenticating ownership claims. Constructions of (2,2)-separating systems derived from error-correcting codes are given, together with bounds on their parameters based on distance considerations.

System for automatic synthesis of automata

System for automatic synthesis of automata

On the Learnability of Infinitary Regular Sets

In this paper we extend the automaton synthesis paradigm to infinitary languages, that is, to subsets of the set Σω of all infinite sequences over some alphabet Σ. Our main result is a polynomial algorithm for learning a sub-class of the ω-regular sets from membership queries and counter-examples based on the framework suggested by Angluin (Angluin, D. (1987), Inform. and Comput.75, 87-106) for learning regular subsets of Σ*.

Determinization of logical specifications of automata

The present article is a continuation of a series of studies on functional synthesis of automata from their logical specifications. A specification language L based on the logic of one-place predicates interpreted on the set of integers has been described. A specification S in this language defines the class K(S) of equivalent nondeterministic automata. If S is treated as a specification of deterministic automata, then the class of all automata satisfying the specification S is identical with the class of all determinizations of any automaton from K(S). The problem of functional synthesis of a deterministic automaton specified in the language L involves constructing a procedural representation of the automaton (i.e., a representation in terms of states and transition and output functions) that satisfies the original specification. It thus includes the construction of one or several determinizations of an automaton from the class K(S). The last problem can be solved either on the procedural level (i.e., the level of the automaton graph) by constructing a procedural representation of an automation from K(S) or on the logical level (i.e., the level of formulas in the language L). In this article, we propose a solution of the problem based on the methodology ofmore » verification design of automaton. An essential feature of this methodology is that all transformations of the automaton being designed (except the construction of a procedural representation of the automaton) are carried out on the level of specification language formulas. This permits using logic methods to verify the correctness of the applied by the designer in the process of design. The problem is accordingly formulated as follows: given the specification S, constructed a specification S such that K(S{sup *}) is a class of equivalent deterministic automata that are determinizations of automata from K(S).« less

Synthesis of automata from elements with given constraints on their complexity

Techniques for logic synthesis of control units from elements with given constraints on their complexity are presented. Programmable logic arrays (PLA) with restrictions on the number of inputs, outputs and terms are used as an example of such elements. Two synthesis methods are suggested: terms distribution and distribution of pairs (term, function), and two algorithms, precise and approximate, are described. The results of computational experiments with these algorithms are discussed.

Control of Infinite Behavior of Finite Automata

A problem in the control of automata on infinite strings is defined and analyzed. The key to the investigation is the development of a fixpoint characterization of the of a deterministic Rabin automaton, the set of states from which the automaton can be controlled to the satisfaction of its own acceptance condition. The fixpoint representation allows straightforward computation of the controllability subset and the construction of a suitable state-feedback control for the automaton. The results have applications to control synthesis, automaton synthesis, and decision procedures for logical satisfiability; in particular, they represent a direct, efficient and natural solution to Church's problem, the construction of winning strategies for two-player zero-sum $\omega$-regular games of perfect information, and the emptiness problem for automata on infinite trees.

Digital Synthesis of Self-Modifying Waveforms by Means of Linear Automata

Linear Automata Synthesis (LASy) is a new sound synthesis technique that uses cellular automata as models for the evolution of the synthesized sound. The technique has two positive characteristics: simplicity of the computational algorithm (realtime synthesis is possible using a common microprocessor); and the wealth of musical results that can be achieved. The LASy technique allows the creation of a large range of timbres, from simple tones (e.g., the Karplus-Strong plucked string algorithm may be simulated by some automata) to very complex ones. Due to the computational properties of the algorithm, the generation of a large family of sounds presents a unique character not found in classical synthesis techniques. This article gives some guidelines for practical implementation and musical applications of the LASy algorithm. The drawbacks of the LASy technique are examined too, along with some methods to avoid them. Elements for the analysis of the synthesis algorithm are given in Appendix 1.

Synthesis of automata given by A system of integer functions

Synthesis of automata given by A system of integer functions

Statistical reliability synthesis of automata with arbitrary alphabets

Statistical reliability synthesis of automata with arbitrary alphabets

Synthesis of automata, asymptotically optimal in stationary random media

Synthesis of automata, asymptotically optimal in stationary random media

Analysis and synthesis of automata given by a system of excitation and output functions

Analysis and synthesis of automata given by a system of excitation and output functions