Finite State Automata Research Articles

Hierarchical control for generator and battery in the more electric aircraft

This paper addresses the problem of intelligent power management for the more electric aircraft framework. The main objective is to regulate the power flow between a low voltage and a high voltage busses through control of a Buck-Boost converter unit. This approach allows the battery to help the generator when an overload scenario occurs, keeping at the same time the battery state of charge above a prescribed threshold. Moreover, in case a continued severe overload causes the battery state of charge to drop below a prescribed threshold, partial shedding of (noncritical) loads occurs. The control objectives are achieved through the design of a hierarchical control strategy based on high gain control for the low level and a finite state automaton for the high level control. Rigorous mathematical proofs of stability are provided for both low level and high level control and a detailed simulator with accurate model of the battery is presented in order to demonstrate the correctness and effectiveness of the proposed approach.

Bound-decreasing duplication system

We introduce the bound-decreasing duplication operation, a new variant of tandem duplication operation, that has restrictions on the position and the maximum size of the duplication segment in a target string. Then, we examine the bound-decreasing duplication system that iteratively generates strings from an initial string using the bound-decreasing duplication operation.We show that there exists a nondeterministic finite-state automaton (NFA) accepting all strings generated by the bound-decreasing duplication system when an initial input is a single string; in other words, the bound-decreasing duplication system produces a regular language. This helps us to calculate the system capacity based on the corresponding NFA. Furthermore, we revisit a deduplication operation—a reverse process of duplication—on an NFA that transforms a given NFA to a smaller NFA while generating the same language by the string duplication system.

Parallel and Distributed Pattern Mining

The treatment of large data is difficult and it looks like the arrival of the framework MapReduce is a solution of this problem. This framework can be used to analyze and process vast amounts of data. This happens by distributing the computational work across a cluster of virtual servers running in a cloud or a large set of machines. Process mining provides an important bridge between data mining and business process analysis. Its techniques allow for extracting information from event logs. Generally, there are two steps in process mining, correlation definition or discovery and the inference or composition. First of all, their work mines small patterns from 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; and the final model is the combination of only two types of different patterns whom are represented by the regular expressions (ab)* and (ab*c)*. Second, they compute these patterns in parallel, and then combine those small patterns using the Hadoop framework. They have two steps; the first is the Map Step through which they mine patterns from execution traces, and the second one is the combination of these small patterns as a reduce step. The results show that their approach is scalable, general and precise. It minimizes the execution time by the use of the Hadoop framework.

Supervisory Control of Communicating Timed Discrete Event Systems for State Avoidance Problem

We study the supervisory control of timed discrete event systems (TDESs) communicating via unbounded FIFO channels. We model a local TDES by a finite-state automaton with a special event of the global clock. A local supervisor observes the events generated by the corresponding local TDES, and estimates the current state of the other local TDESs based on the synchronized global clock and the received events. We study the state avoidance problem, and propose a distributed control algorithm for the local supervisors to collectively control the global system not to reach a given set of undesirable states.

General Fuzzy Finite Switchboard Automata

The constructions of finite switchboard state automata are known to be an extension of finite automata in the view of commutative and switching state machines. This research incorporated an idea of a switchboard in the general fuzzy automata to introduce general fuzzy finite switchboard automata. The attained output reveals that a strongly connected general fuzzy finite switchboard automaton is equivalent to the retrievable general fuzzy automata. Further, the notion of the switchboard subsystem and strong switchboard subsystem of general fuzzy finite switchboard automata are examined. Finally, the concept of fuzzy topology on general fuzzy finite switchboard automata in terms of these characterisations is formulated.

Deciding probabilistic simulation between probabilistic pushdown automata and finite-state systems

Checking whether a pushdown automaton is simulated – in the sense of a simulation pre-order – by a finite-state automaton is EXPTIME-complete. This paper shows that the same computational complexity is obtained in a probabilistic setting. That is, the problem of deciding whether a probabilistic pushdown automaton (pPDA) is simulated by a finite Markov decision process (MDP) is EXPTIME-complete. The considered pPDA contain both probabilistic and non-deterministic branching. The EXPTIME-membership is shown by combining a partition-refinement algorithm with a tableaux system that is inspired by Stirling's technique for bisimilarity checking of ordinary pushdown automata. The hardness is obtained by exploiting the EXPTIME-hardness for the non-probabilistic case. Moreover, our decision problem is in PTIME when both the number of states of the pPDA and the number of states in the MDP are fixed.

Finite state automaton based control system for walking machines

Walking machines have proved to be an important invention as they do not require any prepared surface, making them ideal for applications involving unexplored environments. They are equipped with a large number of actuators and sensors to achieve a robust locomotion; thus, a systematic approach to designing their control system is required. This article presents a functional control structure based on the logic-labelled finite state automaton approach developed for walking machines. A general control structure is presented and a hexapod robot is used to verify the practicability of the design.

A Novel Machine Translation Method based on Stochastic Finite Automata Model for Spoken English

Stochastic finite automata have been applied to a variety of fields, machine trans-lation is one of them. It can learn from data and build model automatically from training sets. Stochastic finite automata are well adapted for the constrained inte-gration of pairs of sentences for language processing. In this paper, a novel ma-chine translation method based on stochastic finite automata is proposed. The method formalized rational grammars by using stochastic finite automata. Through given pairs of source and target utterances, our proposed method will produce a series of conventional rules from which a stochastic rational grammar would be inferred, and the grammar is finally converted into a finite state automa-ton. The efficacy and accuracy of our proposed method is evaluated by a large number of English-Chinese and Chinese-English machine translation experi-ments.

Turkish lexicon expansion by using finite state automata

Turkish is an agglutinative language with rich morphology. A Turkish verb can have thousands of different word forms. Therefore, sparsity becomes an issue in many Turkish natural language processing (NLP) applications. This article presents a model for Turkish lexicon expansion. We aimed to expand the lexicon by using a morphological segmentation system by reversing the segmentation task into a generation task. Our model uses finite-state automata (FSA) to incorporate orthographic features and morphotactic rules. We extracted orthographic features by capturing phonological operations that are applied to words whenever a suffix is added. Each FSA state corresponds to either a stem or a suffix category. Stems are clustered based on their parts-of-speech (i.e. noun, verb, or adjective) and suffixes are clustered based on their allomorphic features. We generated approximately 1 million word forms by using only a few thousand Turkish stems with an accuracy of 82.36%, which will help to reduce the out-of-vocabulary size in other NLP applications. Although our experiments are performed on Turkish language, the same model is also applicable to other agglutinative languages such as Hungarian and Finnish.

Policy-Compliant Maximum Network Flows

Computer network administrators are often interested in the maximal bandwidth that can be achieved between two nodes in the network, or how many edges can fail before the network gets disconnected. Classic maximum flow algorithms that solve these problems are well-known. However, in practice, network policies are in effect, severely restricting the flow that can actually be set up. These policies are put into place to conform to service level agreements and optimize network throughput, and can have a large impact on the actual routing of the flows. In this work, we model the problem and define a series of progressively more complex conditions and algorithms that calculate increasingly tighter bounds on the policy-compliant maximum flow using regular expressions and finite state automata. To the best of our knowledge, this is the first time that specific conditions are deduced, which characterize how to calculate policy-compliant maximum flows using classic algorithms on an unmodified network.

Transliteration Balinese Script using Finite State Automata (FSA) Algorithm

Currently only few people are able to write with Balinese script. This research has main goal to transform the Latin alphabet in the language of Bali to Balinese script using Finite State Automata (FSA). FSA algorithm is using six syllables that exist in the Balinese language structure and generates by font Bali simbar-b. In this test, the use of the Application has advantages (a) the characters generated can be copied and pasted in another document (b) completeness of Balinese script can be written (c) applications run on Linux OS, Windows, Mac OS. The Application is developed in GTK with C# language. The application was tested in (1) Syllables base (2) Basic word (3) marker vocals word (4) Vocal independent (5) marker semi-vowel word (6) Characters Swaitha (7) Pengange Tengenan (8) other markers (9 ) syllable other (10) numbers (11) punctuation (12) variations in the use of Tedung (13) stands (14) transliteration paragraphs to result 94% accuracy. Some of the drawback in this transliteration using a local database technology are some rule from Balinese Script not applied in algorithms

An approach integrating planning and image-based visual servo control for road following and moving obstacles avoidance

ABSTRACT This paper proposes an approach that integrates planning and image based visual servo control for road following and moving obstacle avoidance. One main objective of this article is to represent a robot's general plan or strategy in the form of a finite state machine or automaton. This automaton is designed previously to execution of the plan and then it is used for any instance of the robot's task. The visual servo control is used to regulate the robot's velocity according to the visual target (task specification) which depends on the state in the automaton. All the algorithms and control laws have been implemented and simulation results and experiments with a real scale-size car-like robot are presented and discussed.

Trace abstraction modulo probability

We propose trace abstraction modulo probability, a proof technique for verifying high-probability accuracy guarantees of probabilistic programs. Our proofs overapproximate the set of program traces using failure automata, finite-state automata that upper bound the probability of failing to satisfy a target specification. We automate proof construction by reducing probabilistic reasoning to logical reasoning: we use program synthesis methods to select axioms for sampling instructions, and then apply Craig interpolation to prove that traces fail the target specification with only a small probability. Our method handles programs with unknown inputs, parameterized distributions, infinite state spaces, and parameterized specifications. We evaluate our technique on a range of randomized algorithms drawn from the differential privacy literature and beyond. To our knowledge, our approach is the first to automatically establish accuracy properties of these algorithms.

Pattern analysis and texture classification using finite state automata scheme

The paper proposes a complete modelling of finite state automata along with the associated classifier for texture classification. Pattern analysis of the texture image is performed by proposing a symbolic pattern-based algorithm. This algorithm is developed based on the symbolic dynamics and finite state automata theory for estimating the state transition of the texture variations. Texture image is divided into several partitions, i.e., texture, background of the texture, shadow of the texture, etc. Finite automata state transitions are used to extract the features from the symbolised image. A binary classifier is designed to classify the texture categories based on the feature extraction from the finite automata theory. Pattern analysis is performed on the KITH-TIPS dataset for ten varied categories of texture. 99.12% classification accuracy is achieved when compared with other state-of-art techniques. The experimental study shows the better efficiency of the proposed system when compared to other existing methods.

Radiomic Features for Medical Images Tamper Detection by Equivalence Checking

Digital medical images are very easy to be modified for illegal purposes. An attacker may perform this act in order to stop a political candidate, sabotage research, commit insurance fraud, perform an act of terrorism, or even commit murder. Between the machine that performs medical scans and the radiologist monitor, medical images pass through different devices: in this chain an attacker can perform its malicious action. In this paper we propose a method aimed to avoid medical images modifications by means of equivalence checking. Magnetic images are represented as finite state automata and equivalence checking is exploited to check whether the medical resource have been subject to illegal modifications.

You click, I steal: analyzing and detecting click hijacking attacks in web pages

Click Hijacking (clickjacking) is emerging as a web-based threat on the Internet. The prime objective of clickjacking is stealing user clicks. An attacker can carry out a clickjacking attack by tricking the victim into clicking an element that is barely visible or completely hidden. By stealing the victim’s clicks, an attacker could entice the victim to perform an unintended action from which the attacker can benefit. These actions include online money transactions, sharing malicious website links, initiate social networking links, etc. This paper presents an anatomy of advanced clickjacking attacks not yet reported in the literature. In particular, we propose new class of clickjacking attacks that employ SVG filters and create various effects with SVG filters. We demonstrate that current defense techniques are ineffective to deal with these sophisticated clickjacking attacks. Furthermore, we develop a novel detection method for such attacks based on the behavior (response) of a website active content against the user clicks (request). In our experiments, we found that our method can detect advanced Scalable Vector Graphics (SVG)-based attacks where most of the contemporary tools fail. We explore and utilize various common and distinguishing characteristics of malicious and legitimate web pages to build a behavioral model based on Finite State Automaton. We evaluate our proposal with a sample set of 78,000 web pages from various sources, and 1000 web pages known to involve clickjacking. Our results demonstrate that the proposed solution enjoys good accuracy and a negligible percentage of false positives (i.e., 0.28%), and zero false negatives in distinguishing clickjacking and legitimate websites.

농업용 군집드론 시스템을 제어하기 위한 관리제어기 설계 : 예비결과

A discrete event systems (DES) based approach is an efficient method to control complex dynamic systems. This paper describes a DES which uses supervisory control theory to control multiple. Agricultural unmanned aerial vehicles (UAVs). Finite state automata (FSA) are used as a modeling tool to design a supervisor to coordinate the behavior of multiple UAVs. In this paper, DES models for obstacle avoidance, path following, formation control, and task control are modeled by the FSA and controlled by the supervisor. The proposed supervisors are implemented. Their controllability, nonblocking, and non-conflicting behaviors are verified through simulation. The use of the DES formalism reflects a modular controllable system with the potential for reusability and scalability.

DOPdefender: An approach to thwarting data-oriented programming attacks based on a data-aware automaton

In recent years, non-control data attacks have become a popular topic in the field of network security. These attacks, such as data-oriented programming (DOP), do not aim to circumvent the control-flow integrity (CFI) protections; rather, they need corrupt only the security-critical non-control data of the target program. Non-control data attacks have been shown to achieve Turing-complete computation. In this paper, we build a non-control data attack description model and analyse feasible defence strategies. We present a new program behaviour model, i.e., the data-aware finite-state automaton (dFSA). Based on the dFSA, we propose the DOPdefender method, which is a method of defending against non-control data attacks. DOPdefender monitors the target process and is aware of the security-critical non-control data that are expected to be operated at runtime, thus validating the legality of the operation on the security-critical non-control data. DOPdefender can prevent adversaries from corrupting the security-critical non-control data of the target program and defend against existing non-control data attacks. We evaluate our method on a Linux operating system. An effectiveness test and a performance test indicate the effectiveness of DOPdefender in thwarting non-control data attacks with a 28.4% runtime overhead on average for CPU-intensive programs and a 13.5% runtime overhead on average for I/O-intensive programs. In the Limitations Section, we discuss a solution to making our method scalable for large-scale programs under some guiding information.

Improved deep packet inspection in data stream detection

Finite state automata are widely used in firewalls, data detection and content audit systems to match complex sets of regular expressions in network packets. However, with the continuous increase in the types of network contents and network traffics in recent years, the deep packet inspection systems based on finite state automata also require regular engines for less memory consumption and higher operating speed. This paper analyzes the feature and problem of finite state automata and improves non-deterministic finite automata by reducing the conversion edge to reduce the memory usage. The experiment results which are made by real-world dataset show that the memory usage is reduced more than half.

Autómatas jugando al dilema del prisionero iterado

This study deals with deterministic strategies for playing the iterated Prisoner's Dilemma. Each strategy is incorporated into the table of a finite state automaton. 4-bit and 16-bit strategies are exhaustively studied on this paper, meanwhile 64-bit strategies have been approached by means of a Genetic Algorithm. Both ideas, of studying deterministic strategies and using a Genetic Algorithm, are in Axelrod's The Complexity of Cooperation.Regardings4-bit strategies, a conclusion has been imposed: Tit for Tat is not the winning strategy.Regarding 16-bit strategies, Tit for Tat has not been the winner either.Regarding 64-bit strategies, we should mention the method to evolve chromosomes found by the Genetic Algorithm confronting them with a control set of strategies. There are also 64-bit strategies better than Tit for Tat.