Complexities of Some Problems Related to Synchronizing, Non-Synchronizing and Monotonic Automata

2015 ◽  
Vol 26 (01) ◽  
pp. 99-121 ◽  
Author(s):  
Uraz Cengiz Türker ◽  
Hüsnü Yenigün
Keyword(s):  
Finite Automata ◽  
The Other ◽  
Np Hard ◽  
Deterministic Finite Automata ◽  
Practical Applications ◽  
Other Hand ◽  
Synchronizable Automaton ◽  
Bio Engineering

In this study, we first introduce several problems related to finding reset words for deterministic finite automata, and present motivations for these problems for practical applications in areas such as robotics and bio-engineering. We then analyse computational complexities of these problems. Second, we consider monotonic and partially specified automata. Monotonicity is known to be a feature simplyfing the synchronizability problems. On the other hand for partially specified automata, synchronizability problems are known to be harder than the completely specified automata. We investigate the complexity of some synchronizability problems for automata that are both monotonic and partially specified. We show that checking the existence, computing one, and computing a shortest reset word for a monotonic partially specified automaton is NP-hard. We also show that finding a reset word that synchronizes 𝓚 number of states (or maximum number of states) of a given monotonic non-synchronizable automaton to a given set of states is NP-hard.

On the Complexity of Deadlock Recovery

1986 ◽  
Vol 9 (3) ◽  
pp. 323-342
Author(s):  
Joseph Y.-T. Leung ◽  
Burkhard Monien
Keyword(s):  
Computational Complexity ◽  
Polynomial Time ◽  
Arbitrary Number ◽  
The Other ◽  
Np Hard ◽  
Total Cost ◽  
Other Hand ◽  
Input Parameters ◽  
Resource Type

We consider the computational complexity of finding an optimal deadlock recovery. It is known that for an arbitrary number of resource types the problem is NP-hard even when the total cost of deadlocked jobs and the total number of resource units are “small” relative to the number of deadlocked jobs. It is also known that for one resource type the problem is NP-hard when the total cost of deadlocked jobs and the total number of resource units are “large” relative to the number of deadlocked jobs. In this paper we show that for one resource type the problem is solvable in polynomial time when the total cost of deadlocked jobs or the total number of resource units is “small” relative to the number of deadlocked jobs. For fixed m ⩾ 2 resource types, we show that the problem is solvable in polynomial time when the total number of resource units is “small” relative to the number of deadlocked jobs. On the other hand, when the total number of resource units is “large”, the problem becomes NP-hard even when the total cost of deadlocked jobs is “small” relative to the number of deadlocked jobs. The results in the paper, together with previous known ones, give a complete delineation of the complexity of this problem under various assumptions of the input parameters.

Effect of Specimen Geometry on the Predicted Mechanical Behavior of Polyethylene Pipe Material

2014 ◽  
Author(s):  
Tarek M. A. A. El-Bagory ◽  
Tawfeeq A. R. Alkanhal ◽  
Maher Y. A. Younan
Keyword(s):  
Mechanical Behavior ◽  
Longitudinal Direction ◽  
Primary Objective ◽  
The Other ◽  
Pipe Material ◽  
Ring Specimen ◽  
Design Data ◽  
Practical Applications ◽  
Other Hand ◽  
Gauge Section

The primary objective of the present paper is to depict the mechanical behavior of high density polyethylene, (HDPE), pipes under different loading conditions with different specimen geometries to provide the designer with reliable design data relevant to practical applications. Therefore, it is necessary to study the effect of strain rate, ring configuration, and grip or fixture type on the mechanical behavior of dumb-bell-shaped, (DBS), and ring specimens made from HDPE pipe material. DBS and ring specimens are cut from the pipe in longitudinally, and circumferential (transverse) direction respectively. On the other hand, the ring specimen configuration is classified into two types; full ring, (FR), and notched ring, (NR) (equal double notch from two sides of notched ring specimen) specimens according to ASTM D 2290-12 standard. Tensile tests are conducted on specimens cut out from the pipe with thickness 10 mm at different crosshead speeds (10–1000 mm/min), and ambient temperature, Ta = 20 °C to investigate the mechanical properties of DBS, and ring specimens. In the case of test specimens taken from longitudinal direction from the pipe a necking phenomenon before failure appears at different locations along the gauge section. On the other hand, the fracture of NR specimens occurs at one notched side. The results demonstrated that the NR specimen has higher yield stress than DBS, and FR specimens at all crosshead speeds. The present experimental work reveals that the crosshead speed has a significant effect on the mechanical behavior of both DBS, and ring specimens. The fixture type plays an important role in the mechanical behavior for both FR and NR specimens at all crosshead speeds.

STATELESS ONE-WAY MULTI-HEAD FINITE AUTOMATA WITH PEBBLES

2014 ◽  
Vol 25 (08) ◽  
pp. 1141-1159 ◽  
Author(s):  
MARTIN KUTRIB ◽  
ANDREAS MALCHER ◽  
MATTHIAS WENDLANDT
Keyword(s):  
Finite Automata ◽  
The Other ◽  
Other Hand ◽  
Emptiness Problem ◽  
The Cost

Stateless variants of deterministic one-way multi-head finite automata with pebbles, that is, automata where the heads can drop, sense, and pick up pebbles, are studied. The relation between heads and pebbles is investigated, and a proper double hierarchy concerning these two resources is obtained. Moreover, it is shown that a conversion of an arbitrary automaton to a stateless automaton can always be achieved at the cost of additional heads and/or pebbles. On the other hand, there are languages where one head cannot be traded for any number of additional pebbles and vice versa. Finally, the emptiness problem and related problems are shown to be undecidable even for the ‘simplest’ model, namely, for stateless one-way finite automata with two heads and one pebble.

Space-bounded OTMs and REG ∞

Computability ◽  
2021 ◽  
pp. 1-16
Author(s):  
Merlin Carl
Keyword(s):  
Complexity Theory ◽  
Turing Machine ◽  
Finite Automata ◽  
Regular Languages ◽  
The Other ◽  
Deterministic Finite Automata ◽  
Logarithmic Space ◽  
Working Space ◽  
Important Theorem

An important theorem in classical complexity theory is that REG = LOGLOGSPACE, i.e., that languages decidable with double-logarithmic space bound are regular. We consider a transfinite analogue of this theorem. To this end, we introduce deterministic ordinal automata (DOAs) and show that they satisfy many of the basic statements of the theory of deterministic finite automata and regular languages. We then consider languages decidable by an ordinal Turing machine (OTM), introduced by P. Koepke in 2005 and show that if the working space of an OTM is of strictly smaller cardinality than the input length for all sufficiently long inputs, the language so decided is also decidable by a DOA, which is a transfinite analogue of LOGLOGSPACE ⊆ REG; the other direction, however, is easily seen to fail.

Assessing the Utilization of Automata in Representing Players' Behaviors in Game Theory

Game Theory ◽  
2017 ◽  
pp. 106-119
Author(s):  
Khaled Suwais
Keyword(s):  
Game Theory ◽  
Cellular Automata ◽  
Finite Automata ◽  
The State ◽  
The Other ◽  
Direct Impact ◽  
Complex Environments ◽  
Other Hand ◽  
Different Types ◽  
State Of Art

Representing players' strategies in game theory has a direct impact on the players' performance. The state of art shows that automata are one of the primary techniques used for representing players' strategies and behaviors. In this paper, the author will identify different types of automata and assess their utilization in the field of game theory. Is has been found that finite automata, adaptive automata, and cellular automata are widely adopted in game theory. The utilization of finite automata is found to be limited to represent simpler players' behavior. On the other hand, adaptive automata and cellular automata are intensively applied in complex environments, where the number of interacted players is large and therefore, representing complex behaviors are needed.

scholarly journals The limits of distribution-free conditional predictive inference

2020 ◽  
Author(s):  
Rina Foygel Barber ◽  
Emmanuel J Candès ◽  
Aaditya Ramdas ◽  
Ryan J Tibshirani
Keyword(s):  
The Other ◽  
Conditional Inference ◽  
Predictive Inference ◽  
Distribution Free ◽  
Conformal Prediction ◽  
Underlying Distribution ◽  
Practical Applications ◽  
Other Hand ◽  
Test Points ◽  
Exact Conditional Inference

Abstract We consider the problem of distribution-free predictive inference, with the goal of producing predictive coverage guarantees that hold conditionally rather than marginally. Existing methods such as conformal prediction offer marginal coverage guarantees, where predictive coverage holds on average over all possible test points, but this is not sufficient for many practical applications where we would like to know that our predictions are valid for a given individual, not merely on average over a population. On the other hand, exact conditional inference guarantees are known to be impossible without imposing assumptions on the underlying distribution. In this work, we aim to explore the space in between these two and examine what types of relaxations of the conditional coverage property would alleviate some of the practical concerns with marginal coverage guarantees while still being possible to achieve in a distribution-free setting.

ON THE EXISTENCE OF LOOKAHEAD DELEGATORS FOR NFA

2007 ◽  
Vol 18 (05) ◽  
pp. 949-973 ◽  
Author(s):  
BALA RAVIKUMAR ◽  
NICOLAE SANTEAN
Keyword(s):  
Open Problem ◽  
Finite Automata ◽  
Fixed Number ◽  
Buffer Size ◽  
Membership Problem ◽  
Web Services Composition ◽  
Deterministic Finite Automata ◽  
Practical Applications ◽  
Services Composition ◽  
The Right

We investigate deterministically simulating (i.e., solving the membership problem for) nondeterministic finite automata (NFA), relying solely on the NFA's resources (states and transitions). Unlike the standard NFA simulation, involving an algorithm which stores at each step all the states reached nondeterministically while reading the input, we consider deterministic finite automata (DFA) with lookahead, which choose the “right” NFA transitions based on a fixed number of input symbols read ahead. This concept, known as lookahead delegation, arose in a formal study of web services composition and its subsequent practical applications. Here we answer several related questions, such as “when is lookahead delegation possible?” and “how hard is it to find a delegator with a given lookahead buffer size?”. In particular, we show that only finite languages have the property that all their NFA have delegators. This implies, among others, that delegation is a machine property, rather than a language property. We also prove that the existence of lookahead delegators for unambiguous NFA is decidable, thus partially solving an open problem. Finally, we show that finding delegators (even for a given buffer size) is hard in general, and is more efficient for unambiguous NFA, and we give an algorithm and a compact characterization for NFA delegation in general.

scholarly journals Reversible parallel communicating finite automata systems

2021 ◽  
Vol 58 (4) ◽  
pp. 263-279
Author(s):  
Henning Bordihn ◽  
György Vaszil
Keyword(s):  
Finite Automata ◽  
Regular Languages ◽  
The Other ◽  
Deterministic Case ◽  
Computational Power ◽  
Deterministic Finite Automata ◽  
Relationship Of ◽  
The Relationship ◽  
Context Free

AbstractWe study the concept of reversibility in connection with parallel communicating systems of finite automata (PCFA in short). We define the notion of reversibility in the case of PCFA (also covering the non-deterministic case) and discuss the relationship of the reversibility of the systems and the reversibility of its components. We show that a system can be reversible with non-reversible components, and the other way around, the reversibility of the components does not necessarily imply the reversibility of the system as a whole. We also investigate the computational power of deterministic centralized reversible PCFA. We show that these very simple types of PCFA (returning or non-returning) can recognize regular languages which cannot be accepted by reversible (deterministic) finite automata, and that they can even accept languages that are not context-free. We also separate the deterministic and non-deterministic variants in the case of systems with non-returning communication. We show that there are languages accepted by non-deterministic centralized PCFA, which cannot be recognized by any deterministic variant of the same type.

scholarly journals Chatbot and its Practical Applications in the Materialistic World

2019 ◽  
Vol 8 (4) ◽  
pp. 4459-4463
Keyword(s):  
Artificial Intelligence ◽  
Machine Learning ◽  
Industrial Revolution ◽  
Gradual Increase ◽  
The Other ◽  
Way Of Life ◽  
Practical Applications ◽  
Other Hand ◽  
The World ◽  
Different Types

These days Chat has become the new way of conversation and changed the way of life and the view that the world used to see before and due to Industrial revolution 4.0 , the gradual increase in machine learning and artificial intelligence fields has gone to higher and many companies are reaching customers to get their products with more ease . This is where chatbots are used. It all started with one question! can machines think? The concept of chatbots came into existence to check whether the machines could fool users and make them think that they are actually talking to humans and not robots. On the Other hand, with the Successes Rate of Chat bots, Different companies Started using machines for having conversations with their customers about everything which made their work simpler and reduced the need of man power. There are many different types of building a chatbot but this paper will mainly concentrate on building a Chatbot using TensorFlow API in python

scholarly journals PRINCIPAIS DESAFIOS DAS CIDADES BRASILEIRAS E ALTERNATIVAS OPORTUNIZADAS PELA INTERNET DAS COISAS

2020 ◽  
Vol 11 (1) ◽  
pp. 39-51
Author(s):  
Deuzilene Braga Santana ◽  
Vivianni Marques Leite dos Santos
Keyword(s):  
Decision Making ◽  
Internet Of Things ◽  
Electronic Devices ◽  
The Other ◽  
The Internet ◽  
Systematic Mapping ◽  
Practical Applications ◽  
Other Hand ◽  
The Internet Of Things ◽  
Internet Network

The Internet of Things (IoT) is a technology that encompasses electronic devices that have embedded technologies, sensors and connection to the Internet network, capable of collecting, processing, transmitting data and sharing information among each other, in order to transform data into information for decision making. On the other hand, there are still urban challenges facing cities where IoT can contribute. Aiming to support this theme, this study developed a systematic mapping of the literature on IoT and the main challenges faced by Brazilian cities, pointing out existing initiatives and alternatives of how IoT can help to solve them. The results showed evidence of practical applications on the use of IoT as a solution to the challenges in the cities. In addition, these results suggest the feasibility of using IoT in the solution of these problems.  

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