Search results for "HD"

Entrepreneurship and psychological disorders in academic publishing

2019

The role that different psychological disorders play in entrepreneurial intentions and behaviors is of increasing interest and importance to the scientific community. Scholars have undertaken a range of investigations that demonstrate that individuals with specific psychological disorders should be treated differently to other individuals. Some studies contribute to psychological disorders shifting from a disability paradigm to a paradigm of diversity. The main objective of this work is to carry out a preliminary analysis of the literature published about the relationship between psychological disorders and entrepreneurship. For this purpose, a bibliometric methodology and a fractional coun…

Simulation is decidable for one-counter nets

1998

We prove that the simulation preorder is decidable for the class of one-counter nets. A one-counter net consists of a finite-state machine operating on a variable (counter) which ranges over the natural numbers. Each transition can increase or decrease the value of the counter. A transition may not be performed if this implies that the value of the counter becomes negative. The class of one-counter nets is computationally equivalent to the class of Petri nets with one unbounded place, and to the class of pushdown automata where the stack alphabet is restricted to one symbol. To our knowledge, this is the first result in the literature which gives a positive answer to the decidability of sim…

Superiority Of One-Way And Realtime Quantum Machines

2012

In automata theory, quantum computation has been widely examined for finite state machines, known as quantum finite automata (QFAs), and less attention has been given to QFAs augmented with counters or stacks. In this paper, we focus on such generalizations of QFAs where the input head operates in one-way or realtime mode, and present some new results regarding their superiority over their classical counterparts. Our first result is about the nondeterministic acceptance mode: Each quantum model architecturally intermediate between realtime finite state automaton and one-way pushdown automaton (one-way finite automaton, realtime and one-way finite automata with one-counter, and realtime push…

Automata and differentiable words

2011

We exhibit the construction of a deterministic automaton that, given k > 0, recognizes the (regular) language of k-differentiable words. Our approach follows a scheme of Crochemore et al. based on minimal forbidden words. We extend this construction to the case of C\infinity-words, i.e., words differentiable arbitrary many times. We thus obtain an infinite automaton for representing the set of C\infinity-words. We derive a classification of C\infinity-words induced by the structure of the automaton. Then, we introduce a new framework for dealing with \infinity-words, based on a three letter alphabet. This allows us to define a compacted version of the automaton, that we use to prove that ev…

On the Class of Languages Recognizable by 1-Way Quantum Finite Automata

2007

It is an open problem to characterize the class of languages recognized by quantum finite automata (QFA). We examine some necessary and some sufficient conditions for a (regular) language to be recognizable by a QFA. For a subclass of regular languages we get a condition which is necessary and sufficient. Also, we prove that the class of languages recognizable by a QFA is not closed under union or any other binary Boolean operation where both arguments are significant.

Quantum Pushdown Automata

2000

Quantum finite automata, as well as quantum pushdown automata were first introduced by C. Moore, J. P. Crutchfield [13]. In this paper we introduce the notion of quantum pushdown automata (QPA) in a non-equivalent way, including unitarity criteria, by using the definition of quantum finite automata of [11]. It is established that the unitarity criteria of QPA are not equivalent to the corresponding unitarity criteria of quantum Turing machines [4]. We show that QPA can recognize every regular language. Finally we present some simple languages recognized by QPA, two of them are not recognizable by deterministic pushdown automata and one seems to be not recognizable by probabilistic pushdown …

TIGHT BOUNDS FOR THE SPACE COMPLEXITY OF NONREGULAR LANGUAGE RECOGNITION BY REAL-TIME MACHINES

2013

We examine the minimum amount of memory for real-time, as opposed to one-way, computation accepting nonregular languages. We consider deterministic, nondeterministic and alternating machines working within strong, middle and weak space, and processing general or unary inputs. In most cases, we are able to show that the lower bounds for one-way machines remain tight in the real-time case. Memory lower bounds for nonregular acceptance on other devices are also addressed. It is shown that increasing the number of stacks of real-time pushdown automata can result in exponential improvement in the total amount of space usage for nonregular language recognition.

A graph theoretic approach to automata minimality

2012

AbstractThe paper presents a graph-theoretic approach to test the minimality of a deterministic automaton. In particular, we focus on problems concerning the dependence of the minimality of an automaton on the choice of the set F of final states or on the cardinality of the set F. We introduce different minimality conditions of an automaton and show that such conditions can be characterized in graph-theoretic terms.

Naiskuvan rakentuminen Sport-lehdessä

2014

Arjen kuva naistenlehdissä : arjen ajan ja paikan representaatioiden kielellistä tarkastelua vuoden 2011 Kotiliesi- ja Kotivinkki-lehdissä

2012

Tutkielma käsittelee arjen kielellisiä esittämistapoja mediatekstien kontekstissa. Työn tarkoituksena on perehtyä arjen lingvistiseen kuvaukseen kahdessa eri naistenlehdessä, Kotiliedessä ja Kotivinkissä. Arjen kuvaamisen tapoja eli representaatioita tutkiva työ on toteutettu konstruktionistisen ja diskursiivisen kielikäsityksen kehyksessä. Tutkimuksen aihe on yhteiskunnallisesti ajankohtainen ja liittyy elämäntapavalinnoista käytävään keskusteluun. Representaatioita tutkiva työ keskittyy arjen ajan ja paikan kartoittamiseen. Tutkielman keskeisimpänä tavoitteena on arjen rytmin käsitteen ympärille hahmottuvan tutkimustehtävän ratkaiseminen. Tutkimuksen keinoin on tarkoitus selvittää arjen r…