Finite State Automata Research Articles

Formalizing falsification for theories of consciousness across computational hierarchies.

The scientific study of consciousness is currently undergoing a critical transition in the form of a rapidly evolving scientific debate regarding whether or not currently proposed theories can be assessed for their scientific validity. At the forefront of this debate is Integrated Information Theory (IIT), widely regarded as the preeminent theory of consciousness because it quantified subjective experience in a scalar mathematical measure called that is in principle measurable. Epistemological issues in the form of the “unfolding argument” have provided a concrete refutation of IIT by demonstrating how it permits functionally identical systems to have differences in their predicted consciousness. The implication is that IIT and any other proposed theory based on a physical system’s causal structure may already be falsified even in the absence of experimental refutation. However, so far many of these arguments surrounding the epistemological foundations of falsification arguments, such as the unfolding argument, are too abstract to determine the full scope of their implications. Here, we make these abstract arguments concrete, by providing a simple example of functionally equivalent machines realizable with table-top electronics that take the form of isomorphic digital circuits with and without feedback. This allows us to explicitly demonstrate the different levels of abstraction at which a theory of consciousness can be assessed. Within this computational hierarchy, we show how IIT is simultaneously falsified at the finite-state automaton level and unfalsifiable at the combinatorial-state automaton level. We use this example to illustrate a more general set of falsification criteria for theories of consciousness: to avoid being already falsified, or conversely unfalsifiable, scientific theories of consciousness must be invariant with respect to changes that leave the inference procedure fixed at a particular level in a computational hierarchy.

Research of a multithreaded non-deterministic system model

Managing the systems which behaviour is non-deterministic is one of the most important problems in modern management theory. Today, systems with structural and behavioural complexity are prevalent in all areas of human activity, and therefore, their research is of the utmost importance. Such systems, as opposed to deterministic systems, are called non-deterministic. They are characterised by difficult predictable behaviour determined both by external random influences, and within the systems themselves. A clear example of a non-deterministic system is crowds of people, factories, and computer networks and systems. The problem of non-deterministic behaviour directly within the context of professional activities can be seen using an example of building syntactic analysers. The aim of the paper is to design a class of systems oriented towards supporting elements of a discrete event model. The target of research is to simulate discrete event models. The subject of research is a creation of a discrete event model based on the behaviour of an undetermined finite state automaton. During the preparation of the paper, there was developed and practically implemented an algorithm for the application, which materializes the principle of working with threads. The results obtained in the paper are aimed at solving the problem of parallel data processing based on the parallelism of NFA's (non-deterministic finite automaton) behaviour when reading the input string characters. As a result, this should have a positive impact on the regulation of the simulation processes of a non-deterministic system, increasing its efficiency and stability. In conclusion, the algorithm of the application work is disclosed and conclusions about the effectiveness and efficiency of its development are drawn.

Formalized description of cyber-physical systems models using temporary non-deterministic automata

The principles of building finite state automata taking into account temporal logic were considered. In this case, time delays of the input symbol are added to the elements of the finite state automaton, which allow the automaton to change its state without producing an output symbol, as well as delays of the output symbol that determine the necessary time interval for the corresponding transition. The main approaches to the definition of the concept of a process, such as “process is a state” and “process is a transition”, which are characterized by the principles of signal processing, taking into account the possibility of saving the state and forming a queue for signal processing, are distinguished. The scientific novelty of this article lies in the approach to the formation of a hierarchical cyber system and the use of temporary SNDA. This method allows to synchronize processes in multithreaded data processing in complex organized, multilevel systems and excludes the possibility of unstable operation, and also improves the performance of the entire complex. As a visual representation of the model of the created principle of temporal non-deterministic automata, a system of grinding and transferring grain in a mill was used.

Functional approach to deterministic finite-state automata systems dynamic modeling

Research aim is to study the functional approach to modeling the deterministic finite-state automata system which is not confined to the elements communication topology and the heterogeneity of the algorithm types. Relevance. The substantial part of engineering systems applied in the mining industry may be described through the finite-state automaton model. They include the mine conveyor systems, shaft signal systems, processing facilities control systems, etc. Such model makes it possible to shorten the time spent on control software development and carry out algorithm analysis, debug, and testing effectively. There are a lot of effective approaches and tools to solve the problem of finite-state automata dynamic modeling, each of which has its own advantages and disadvantages. Methodology. In this article, the methodology of finite-state automata systems modeling is considered as applied to mine conveyor systems. Results. Final-state automata (FSA) models have been developed together with the conditions for FSA systems dynamic modeling as applied to mine conveyor systems. Conclusions. The considered approach to modeling, which involves functors and applicative functors 122 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 2. 2021 ISSN 0536-1028 for structure composition and its operational dynamics study, as well as the possibility to mathematically prove the model’s properties, makes the approach a good alternative when choosing tools for systems models development.

PENERAPAN KONSEP FINITE STATE AUTOMATA DALAM PROSES PENDAFTARAN KELAS KURSUS BAHASA INGGRIS PADA TEMPAT KURSUS

Research on website-based test applications for digital course registration in order to make it easier for course institutions to determine classes that are consistent and effective and efficient. This research provides alternative solutions for course institutions for class selection or course program that is suitable for users who will study at the place of the course which is cost-effective and time-consuming too. In this study a course registration application is designed by integrating a website and database to retrieve data after the user has tested. It is intended that users who want to learn English can receive a choice of classes or programs in accordance with their abilities and initial knowledge. This minimizing test instructor errors in determining class and program choices that will be obtained by the user. In this study using the Finite State Automata (FSA) method to discuss the NFA type FSA model can be implemented in the registration process to the user (member) where the course is expected as needed and can better understand how the process of class or program selection is effective and right on target

NooJ local grammars and cognitive small worlds:

Over the course of centuries, time has been and still is one of the concepts men have been long investigating, more specifically, the way in which time, in its flow, can be objectively managed and coped with. Scientists, philosophers, writers and artists have tried and still try to make their contribution to the conceptual definition of time, however discovering that it constantly seems to escape any form of definitive and immutable indication, especially as regards the classic tripartite but elusive subdivision of time conceived as past, present and future. Consequently, the postulations regarding the concept of time have produced innumerable and extremely varied statements. To name just two of them, only apparently dissimilar, we will recall Albert Einstein’s "Time is relative, its only value is given by what we do while it is passing" and Marcel Proust’s "The days are perhaps the same for a watch, but not for a man." The attempt to “dominate” time and its continuous and uninterrupted flow is present also in the morphosyntactic structures of natural languages, including Italian. Therefore, the aim of this paper is to assess how date and duration expressions are morphosyntactically built and can be formalised by means of specific NooJ local grammars, finite-state automata (FSA) and graphs.

Checking is Believing: Event-Aware Program Anomaly Detection in Cyber-Physical Systems

Securing cyber-physical systems (CPS) against malicious attacks is of paramount importance because these attacks may cause irreparable damages to physical systems. Recent studies have revealed that control programs running on CPS devices suffer from both control-oriented attacks (e.g., code-injection or code-reuse attacks) and data-oriented attacks (e.g., non-control data attacks). Unfortunately, existing detection mechanisms are insufficient to detect runtime data-oriented exploits, due to the lack of runtime execution semantics checking. In this work, we propose Orpheus, a new security methodology for defending against data-oriented attacks by enforcing cyber-physical execution semantics. We first present a general method for reasoning cyber-physical execution semantics of a control program (i.e., causal dependencies between the physical context and program control flows), including the event identification and dependence analysis. As an instantiation of Orpheus, we then present a new program behavior model, i.e., the event-aware finite-state automaton (eFSA). eFSA takes advantage of the event-driven nature of CPS control programs and incorporates event checking in anomaly detection. It detects data-oriented exploits if a specific physical event is missing along with the corresponding event dependent state transition. We evaluate our prototype's performance by conducting case studies under data-oriented attacks. Results show that eFSA can successfully detect different runtime attacks. Our prototype on Raspberry Pi incurs a low overhead, taking 0.0001s for each state transition integrity checking, and 0.063s~0.211s for the cyber-physical contextual consistency checking.

Identification of Long-Term Behavior of Natural Circulation Loops: A Thresholdless Approach from an Initial Response

Natural circulation loop (NCL) systems are buoyancy-driven heat exchangers that are used in various industrial applications. The concept of passive heat exchange in NCL systems is attractive, because there is no need for an externally driven equipment (e.g., a pump) to maintain the fluid circulation. However, relying on buoyancy as the sole driving force may lead to several potential difficulties, one of which is generation of (possibly) time-varying nonlinearities in the dynamical system, where a difference in the time scales of heat transfer and fluid flow causes the flow to change from a steady-state regime to either an oscillatory regime or a flow-reversal regime, both of which are undesirable. In this paper, an algorithm is developed using tools of symbolic time-series analysis (e.g., probabilistic finite state automata (PFSA)) for the purpose of identifying selected regimes of operation in NCL systems using only data from the early transient operation, where the underlying principle is built upon the concept of pattern classification from measurements of fluid-flow dynamics. The proposed method is shown to be capable of identifying the current regime of operation from the initial time response under a given set of operational parameters. The efficacy of regime classification is demonstrated by testing on two datasets, generated from numerical simulation of a MATLAB SimuLink model that has previously been validated with experimental data. The results of the proposed PFSA-based classification are compared with those of a hidden Markov model (HMM) that serves as the baseline.

Discrete Event Dynamic Modeling and Analysis of the Democratic Progress in a Society Controlled by Networked Agents

This paper proposes a formal framework based on discrete event systems in order to analyze the democratic progress and regression in a society controlled by networked agents. For this purpose, we construct a simple model using a finite state automaton that describes the dynamic behavior of progress and regression in a democracy. We represent a network of agents as a directed graph where each agent has its own objective. Each agent may be a citizen or a group of people sharing a common objective, and it makes decisions on enabling or disabling events upon the observation of states of a system. Agents may have different decisions on the same event, and the final decision follows the majority rule. Upon this framework, we derive the necessary and sufficient conditions for a democratic system controlled by networked agents to be progressive or regressive, where a progressive one implies that it reaches a more equal state at which a larger number of agents meet their objectives. Finally, we obtain some convergence results for special graph topologies.

РАЗРАБОТКА АВТОМАТА НАДЕЖНОСТИ ТЕХНИКИ (обоснование регулирования стандартизации)

Aim . This paper presents the development of the dependability automaton. The development is a conceptual description of the automaton as the term structure of a fixed complexity that shows non-contradictory interrelations and clear dependability state transitions of an item. The description of the state structure of the automaton implies subsequent development of a computing device for monitoring the dependability of items of any nature. Unlike in the standard, dependability is defined as a set of states, the measure of concordance with the purpose of an item. The purpose is defined as the property of an object attributed to the natural origin or designed application. In accordance with such definitions, alternative definitions of dependability states have been developed. An observation of the dependability states of an item can be described with a common algorithm. The problem is defined with the help of the automata theory. Methods . We will call a dependability automaton (DA) a deterministic, fully specified finite-state automaton. In the automata theory, the properties of items are examined in terms of being in states and transitioning between them. Dependability states change in terms of disruption and restoration of item purpose. Such changes can be represented as a directed graph, whose nodes correspond to states, while the edges correspond to transitions between states. As the dependability restoration states are deterministic, they can be represented as processes, i.e. planned, consisting of activities, measures, procedures, operations. The states of disrupted dependability are random, therefore they can be considered as events. Thus, the property of an entity’s purpose is observed when the states of dependability are observed that change in events and processes. The automation is described using terms and symbols from standards, as well as alternative definitions of states developed by the author. A review of the appropriate standards is to involve a new terminology. The operation of the dependability automaton reflects transitions and alternative transitions. Restoration is designed as a complete and partially incomplete processes: a) transition from the down state into the up state; b) transition from the down state into the faulty state; c) transition from the down state into the good state. The findings contributed to the development of theoretical and practical dependability of organization, social groups and individuals. The dependability automaton concept includes the development of the engineering design of an expert decision support system for flight operation of an airline. Conclusion . Technical standards require prior preliminarily philosophical, philological, logical review. Such research is to produce logical proof and substantiation of a set of coordinated, non-contradictory ontological terms: property, state, event, etc. The results will be used in technical standards for the purpose of construction and substantiation of special terms. The paper provides a theoretical and practical substantiation of applying individual provisions of the dependability theory of technology for the purpose of developing the dependability theory of non-digital entities.

Designing efficient algorithms for querying large corpora

I describe several new efficient algorithms for querying large annotated corpora. The search algorithms as they are implemented in several popular corpus search engines are less than optimal in two respects: regular expression string matching in the lexicon is done in linear time, and regular expressions over corpus positions are evaluated starting in those corpus positions that match the constraints of the initial edges of the corresponding network. To address these shortcomings, I have developed an algorithm for regular expression matching on suffix arrays that allows fast lexicon lookup, and a technique for running finite state automata from edges with lowest corpus counts. The implementation of the lexicon as suffix array also lends itself to an elegant and efficient treatment of multi-valued and set-valued attributes. The described techniques have been implemented in a fully functional corpus management system and are also used in a treebank query system.

Copyful Streaming String Transducers

Copyless streaming string transducers (copyless SST) have been introduced by R. Alur and P. Černý in 2010 as a one-way deterministic automata model to define transductions of finite strings. Copyless SST extend deterministic finite state automata with a set of variables in which to store intermediate output strings, and those variables can be combined and updated all along the run, in a linear manner, i.e., no variable content can be copied on transitions. It is known that copyless SST capture exactly the class of MSO-definable string-to-string transductions, and are as expressive as deterministic two-way transducers. They enjoy good algorithmic properties. Most notably, they have decidable equivalence problem (in PSpace). On the other hand, HDT0L systems have been introduced for a while, the most prominent result being the decidability of the equivalence problem. In this paper, we propose a semantics of HDT0L systems in terms of transductions, and use it to study the class of deterministic copyful SST. Our contributions are as follows: (i)HDT0L systems and total deterministic copyful SST have the same expressive power, (ii)the equivalence problem for deterministic copyful SST and the equivalence problem for HDT0L systems are inter-reducible, in quadratic time. As a consequence, equivalence of deterministic SST is decidable, (iii)the functionality of non-deterministic copyful SST is decidable, (iv)determining whether a non-deterministic copyful SST can be transformed into an equivalent non-deterministic copyless SST is decidable in polynomial time.

Michelangelo, the Duck and the Rabbit

The concept of modes of existence of semiotic entities underlies (post)Greimasian semiotics, yet it seems to have received little attention. Modes of existence can be used in different senses. For Greimas, from the perspective of narrative semiotics, when Michelangelo first receives a block of marble and decides to sculpt the David, his intention is in a virtual mode; as Michelangelo progresses he ends up bringing the David into existence, and his intention comes to the realized mode. In Fontanille’s tensive semiotics, however, modes of existence can have to do with how one can narrow or broaden the scope of our apprehension of the David as our eyes look at it in order to produce a meaningful experience. In this work, the perspectives of narrative and tensive semiotics are contrasted both theoretically and practically applying both to a number of examples. In order to identify all possible modes of existence and all the possibilities of transitioning from one to the other in the examples presented, we resort to the method of finite-state automata from computer science. In the end, we propose a robust narrative account of modes of existence that relies on narrative semiotics for its definition, but into which intent and apprehension from tensive semiotics can be integrated. This work calls for the need of establishing a syntax of modes of existence, since both Greimas and Fontanille construe them as being necessary to account for the production of signification.

Subpath Queries on Compressed Graphs: A Survey

Text indexing is a classical algorithmic problem that has been studied for over four decades: given a text T, pre-process it off-line so that, later, we can quickly count and locate the occurrences of any string (the query pattern) in T in time proportional to the query’s length. The earliest optimal-time solution to the problem, the suffix tree, dates back to 1973 and requires up to two orders of magnitude more space than the plain text just to be stored. In the year 2000, two breakthrough works showed that efficient queries can be achieved without this space overhead: a fast index be stored in a space proportional to the text’s entropy. These contributions had an enormous impact in bioinformatics: today, virtually any DNA aligner employs compressed indexes. Recent trends considered more powerful compression schemes (dictionary compressors) and generalizations of the problem to labeled graphs: after all, texts can be viewed as labeled directed paths. In turn, since finite state automata can be considered as a particular case of labeled graphs, these findings created a bridge between the fields of compressed indexing and regular language theory, ultimately allowing to index regular languages and promising to shed new light on problems, such as regular expression matching. This survey is a gentle introduction to the main landmarks of the fascinating journey that took us from suffix trees to today’s compressed indexes for labeled graphs and regular languages.

Adversarial Specification Mining

There have been numerous studies on mining temporal specifications from execution traces. These approaches learn finite-state automata (FSA) from execution traces when running tests. To learn accurate specifications of a software system, many tests are required. Existing approaches generalize from a limited number of traces or use simple test generation strategies. Unfortunately, these strategies may not exercise uncommon usage patterns of a software system. To address this problem, we propose a new approach, adversarial specification mining, and develop a prototype, Diversity through Counter-examples (DICE). DICE has two components: DICE-Tester and DICE-Miner. After mining Linear Temporal Logic specifications from an input test suite, DICE-Tester adversarially guides test generation, searching for counterexamples to these specifications to invalidate spurious properties. These counterexamples represent gaps in the diversity of the input test suite. This process produces execution traces of usage patterns that were unrepresented in the input test suite. Next, we propose a new specification inference algorithm, DICE-Miner, to infer FSAs using the traces, guided by the temporal specifications. We find that the inferred specifications are of higher quality than those produced by existing state-of-the-art specification miners. Finally, we use the FSAs in a fuzzer for servers of stateful protocols, increasing its coverage.

Reliability and Safety of Autonomous Systems Based on Semantic Modelling for Self-Certification

A novel modelling paradigm for online diagnostics and prognostics for autonomous systems is presented. A model for the autonomous system being diagnosed is designed using a logic-based formalism. The model supports the run-time ability to verify that the autonomous system is safe and reliable for operation within a dynamic environment. The paradigm is based on the philosophy that there are different types of semantic relationships between the states of different parts of the system. A finite state automaton is devised for each sensed component and some of the non-sensed components. To capture the interdependencies of components within such a complex robotic platform, automatons were related to each other by semantic relationships. Modality was utilised by the formalism to abstract the relationships and to add measures for the possibility and uncertainty of the relationships. The complexity of the model was analysed to evaluate its scalability and applicability to other systems. The results demonstrate that the complexity is not linear and a computational time of 10 ms was required to achieve run-time diagnostics for 2200 KB of knowledge for complex system interdependences. The ability to detect and mitigate hardware related failures was demonstrated within a confined space autonomous operation. Our findings provide evidence of the applicability of our approach for the significant challenge of run-time safety compliance and reliability in autonomous systems.

Novel Approach for Mining Patterns

Process mining techniques allow for extracting information from event logs. In general, there are two steps in process mining, correlation definition or discovery and then process inference or composition. Firstly, the work consists to mine small patterns from a log traces; those patterns are the representation of the traces execution from a log file of a business process. In this step, the authors use existing techniques. The patterns are represented by finite state automaton or their regular expression. The final model is the combination of only two types of small patterns that are represented by the regular expressions. Secondly, they compute these patterns in parallel and then combine those small patterns using the MapReduce framework. They have two parties the first is the map step. They mine patterns from execution traces, and the second is the combination of these small patterns as reduce step. The results are promising; they show that the approach is scalable, general, and precise. It minimizes the execution time by the use of the MapReduce framework.

Automata-based Algorithm for Multiple Word Matching

In this paper, an automata-based algorithm that finds the valid shifts of a given set of words W in text T is presented. Unlike known string matching algorithms, a preprocessing phase is applied to T and not to the words being searched for. In this phase, a deterministic finite state automaton (DFA) that recognizes the words in T is built and is augmented with their shifts in T. The preprocessing phase is relatively expensive in terms of time and space. However, it needs to be done once for any number of words to match in a given text document. The algorithm is analyzed for complexity, implemented and compared with an adjusted version of KMP algorithm. It showed better performance than KMP algorithm for large number of words to match in T.

A DSL for Resource Checking Using Finite State Automaton-Driven Symbolic Execution

Abstract Static analysis is an essential way to find code smells and bugs. It checks the source code without execution and no test cases are required, therefore its cost is lower than testing. Moreover, static analysis can help in software engineering comprehensively, since static analysis can be used for the validation of code conventions, for measuring software complexity and for executing code refactorings as well. Symbolic execution is a static analysis method where the variables (e.g. input data) are interpreted with symbolic values. Clang Static Analyzer is a powerful symbolic execution engine based on the Clang compiler infrastructure that can be used with C, C++ and Objective-C. Validation of resources’ usage (e.g. files, memory) requires finite state automata (FSA) for modeling the state of resource (e.g. locked or acquired resource). In this paper, we argue for an approach in which automata are in-use during symbolic execution. The generic automaton can be customized for different resources. We present our domain-specific language to define automata in terms of syntactic and semantic rules. We have developed a tool for this approach which parses the automaton and generates Clang Static Analyzer checker that can be used in the symbolic execution engine. We show an example automaton in our domain-specific language and the usage of generated checker.

Development of the technology dependability automaton (substantiation of standardization regulation)

Aim . This paper presents the development of the dependability automaton. The development is a conceptual description of the automaton as the term structure of a fixed complexity that shows non-contradictory interrelations and clear dependability state transitions of an item. The description of the state structure of the automaton implies subsequent development of a computing device for monitoring the dependability of items of any nature. Unlike in the standard, dependability is defined as a set of states, the measure of concordance with the purpose of an item. The purpose is defined as the property of an object attributed to the natural origin or designed application. In accordance with such definitions, alternative definitions of dependability states have been developed. An observation of the dependability states of an item can be described with a common algorithm. The problem is defined with the help of the automata theory. Methods . We will call a dependability automaton (DA) a deterministic, fully specified finite-state automaton. In the automata theory, the properties of items are examined in terms of being in states and transitioning between them. Dependability states change in terms of disruption and restoration of item purpose. Such changes can be represented as a directed graph, whose nodes correspond to states, while the edges correspond to transitions between states. As the dependability restoration states are deterministic, they can be represented as processes, i.e. planned, consisting of activities, measures, procedures, operations. The states of disrupted dependability are random, therefore they can be considered as events. Thus, the property of an entity’s purpose is observed when the states of dependability are observed that change in events and processes. The automation is described using terms and symbols from standards, as well as alternative definitions of states developed by the author. A review of the appropriate standards is to involve a new terminology. The operation of the dependability automaton reflects transitions and alternative transitions. Restoration is designed as a complete and partially incomplete processes: a) transition from the down state into the up state; b) transition from the down state into the faulty state; c) transition from the down state into the good state. The findings contributed to the development of theoretical and practical dependability of organization, social groups and individuals. The dependability automaton concept includes the development of the engineering design of an expert decision support system for flight operation of an airline. Conclusion . Technical standards require prior preliminarily philosophical, philological, logical review. Such research is to produce logical proof and substantiation of a set of coordinated, non-contradictory ontological terms: property, state, event, etc. The results will be used in technical standards for the purpose of construction and substantiation of special terms. The paper provides a theoretical and practical substantiation of applying individual provisions of the dependability theory of technology for the purpose of developing the dependability theory of non-digital entities.