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.

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.

Boosting Reversible Pushdown and Queue Machines by Preprocessing

2020 ◽  
pp. 1-29
Author(s):  
Holger Bock Axelsen ◽  
Martin Kutrib ◽  
Andreas Malcher ◽  
Matthias Wendlandt
Keyword(s):  
Real Time ◽  
Finite Automata ◽  
Point Of View ◽  
Regular Languages ◽  
Theoretical Point ◽  
Computational Power ◽  
Finite State ◽  
Finite State Transducer ◽  
Context Free ◽  
Pushdown Automata

It is well known that reversible finite automata do not accept all regular languages, that reversible pushdown automata do not accept all deterministic context-free languages, and that reversible queue automata are less powerful than deterministic real-time queue automata. It is of significant interest from both a practical and theoretical point of view to close these gaps. We here extend these reversible models by a preprocessing unit which is basically a reversible injective and length-preserving finite state transducer. It turns out that preprocessing the input using such weak devices increases the computational power of reversible deterministic finite automata to the acceptance of all regular languages, whereas for reversible pushdown automata the accepted family of languages lies strictly in between the reversible deterministic context-free languages and the real-time deterministic context-free languages. For reversible queue automata the preprocessing of the input leads to machines that are stronger than real-time reversible queue automata, but less powerful than real-time deterministic (irreversible) queue automata. Moreover, it is shown that the computational power of all three types of machines is not changed by allowing the preprocessing finite state transducer to work irreversibly. Finally, we examine the closure properties of the family of languages accepted by such machines.

DESCRIPTIONAL COMPLEXITY OF NFA OF DIFFERENT AMBIGUITY

2005 ◽  
Vol 16 (05) ◽  
pp. 975-984 ◽  
Author(s):  
HING LEUNG
Keyword(s):  
Finite Automata ◽  
Regular Languages ◽  
The Other ◽  
Deterministic Finite Automata ◽  
Descriptional Complexity ◽  
Nondeterministic Finite Automata ◽  
Initial States

In this paper, we study the tradeoffs in descriptional complexity of NFA (nondeterministic finite automata) of various amounts of ambiguity. We say that two classes of NFA are separated if one class can be exponentially more succinct in descriptional sizes than the other. New results are given for separating DFA (deterministic finite automata) from UFA (unambiguous finite automata), UFA from MDFA (DFA with multiple initial states) and UFA from FNA (finitely ambiguous NFA). We present a family of regular languages that we conjecture to be a good candidate for separating FNA from LNA (linearly ambiguous NFA).

Non-Self-Embedding Grammars, Constant-Height Pushdown Automata, and Limited Automata

2020 ◽  
pp. 1-25
Author(s):  
Bruno Guillon ◽  
Giovanni Pighizzini ◽  
Luca Prigioniero
Keyword(s):  
Finite Automata ◽  
Regular Languages ◽  
Deterministic Finite Automata ◽  
Polynomial Size ◽  
Constant Height ◽  
Double Exponential ◽  
Recursive Structures ◽  
Deterministic Formula ◽  
Context Free ◽  
Pushdown Automata

Non-self-embedding grammars are a restriction of context-free grammars which does not allow to describe recursive structures and, hence, which characterizes only the class of regular languages. A double exponential gap in size from non-self-embedding grammars to deterministic finite automata is known. The same size gap is also known from constant-height pushdown automata and [Formula: see text]-limited automata to deterministic finite automata. Constant-height pushdown automata and [Formula: see text]-limited automata are compared with non-self-embedding grammars. It is proved that non-self-embedding grammars and constant-height pushdown automata are polynomially related in size. Furthermore, a polynomial size simulation by [Formula: see text]-limited automata is presented. However, the converse transformation is proved to cost exponential. Finally, a different simulation shows that also the conversion of deterministic constant-height pushdown automata into deterministic [Formula: see text]-limited automata costs polynomial.

scholarly journals On Newcomb's method of investigating periodicities and its application to Brückner's weather cycle

1914 ◽  
Vol 90 (619) ◽  
pp. 349-355
Keyword(s):  
Thermal Radiation ◽  
The Other ◽  
New Method ◽  
Critical Examination ◽  
Numerical Work ◽  
Average Value ◽  
Other Hand ◽  
Relationship Of ◽  
The Relationship ◽  
Great Simplicity

During the last few years of his life Prof. Simon Newcomb was keenly interested in the problem of periodicities, and devised a new method for their investigation. This method is explained, and to some extent applied, in a paper entitled "A Search for Fluctuations in the Sun's Thermal Radiation through their Influence on Terrestrial Temperature." The importance of the question justifies a critical examination of the relationship of the older methods to that of Newcomb, and though I do not agree with his contention that his process gives us more than can be obtained from Fourier's analysis, it has the advantage of great simplicity in its numerical work, and should prove useful in a certain, though I am afraid, very limited field. Let f ( t ) represent a function of a variable which we may take to be the time, and let the average value of the function be zero. Newcomb examines the sum of the series f ( t 1 ) f ( t 1 + τ) + f ( t 2 ) f ( t 2 + τ) + f ( t 3 ) f ( t 3 + τ) + ..., where t 1 , t 2 , etc., are definite values of the variable which are taken to lie at equal distances from each other. If the function be periodic so as to repeat itself after an interval τ, the products are all squares and each term is positive. If, on the other hand, the periodic time be 2τ, each product will be negative and the sum itself therefore negative. It is easy to see that if τ be varied continuously the sum of the series passes through maxima and minima, and the maxima will indicated the periodic time, or any of its multiples.

scholarly journals Physical Activity and Psychological Well-Being: Testing Alternative Sociological Interpretations

1990 ◽  
Vol 7 (4) ◽  
pp. 329-346 ◽  
Author(s):  
William McTeer ◽  
James E. Curtis
Keyword(s):  
Physical Activity ◽  
Socioeconomic Status ◽  
Social Interaction ◽  
Physical Fitness ◽  
Well Being ◽  
The Other ◽  
Positive Zero ◽  
Psychological Well Being ◽  
Relationship Of ◽  
The Relationship

This study examines the relationship between physical activity in sport and feelings of well-being, testing alternative interpretations of the relationship between these two variables. It was expected that there would be positive relationships between physical activity on the one hand and physical fitness, feelings of well-being, social interaction in the sport and exercise environment, and socioeconomic status on the other hand. It was also expected that physical fitness, social interaction, and socioeconomic status would be positively related to psychological well-being. Further, it was expected that any positive zero-order relationship of physical activity and well-being would be at least in part a result of the conjoint effects of the other variables. The analyses were conducted separately for the male and female subsamples of a large survey study of Canadian adults. The results, after controls, show a modest positive relationship of physical activity and well-being for males but no such relationship for females. The predicted independent effects of the control factors obtained for both males and females. Interpretations of the results are discussed.

THE RELATIONSHIP OF THE SODIUM, POTASSIUM, AND CHLORIDE CONCENTRATION OF THE FEEDING TO THE WEIGHT GAIN OF PREMATURE INFANTS

PEDIATRICS ◽  
1962 ◽  
Vol 30 (6) ◽  
pp. 909-916
Author(s):  
Herbert I. Goldman ◽  
Samuel Karelitz ◽  
Hedda Acs ◽  
Eli Seifter
Keyword(s):  
Weight Gain ◽  
Sodium Chloride ◽  
Human Milk ◽  
Premature Infants ◽  
Chloride Concentration ◽  
The Other ◽  
Milk Formula ◽  
Sodium Potassium ◽  
Relationship Of ◽  
The Relationship

One hundred four healthy premature infants, of birth weight 1,000 to 1,800 gm, were fed one of five feedings: (1) human milk; (2) human milk plus 13 meq/l of sodium chloride; (3) human milk plus 13 meq/l of sodium chloride and 18 meq/l of potassium chloride; (4) a half-skimmed cows milk formula; and (5) a partially-skimmed vegetable oil, cows milk formula. The infants fed any of the three human milk formulas gained weight at a slower rate than the infants fed either of the two cows milk formulas. Infants whose diets were changed from unmodified human milk to the half-skimmed cows milk gained large amounts of weight, and at times were visibly edematous. Infants whose diets were changed from the human milks with added sodium chloride, to the half-skimmed cows milk, gained lesser amounts of weight and did not become edematous. The infants fed the two cows milk diets gained similar amounts of weight, although one diet provided 6.5 gm/kg/day, the other 3.1 gm/kg/day of protein.

Een beetje onsterfelijk

Lampas ◽  
2019 ◽  
Vol 52 (4) ◽  
pp. 437-452
Author(s):  
Gerard Boter
Keyword(s):  
Present Article ◽  
The Other ◽  
Relationship Of ◽  
The Relationship ◽  
Immortality Of The Soul

Summary The present article discusses three hotly debated interpretational issues in Diotima´s speech in Plato´s Symposium. The first of these is the relationship of Diotima´s speech to other dialogues, such as the Phaedo and the Republic, with regard to the immortality of the soul. It is argued that there is no discrepancy at all, because the immortality of the soul does not play any role in the Symposium. The second issue is the nature of the three classes of posterity: biological, spiritual and philosophical. Whereas the posterity of the first two classes can be relatively easily defined, the character of the philosopher´s posterity, ‘true virtue’, remains rather vague. It may consist in dialectical teaching of the Idea of Beauty by Socrates. Thirdly, it is argued that the philosopher´s immortality differs only gradually from the immortality of the other two classes, that is, the philosopher as a man only survives by means of his posterity.

Comparing the Arrangements of Governance and Sustainable Development in OECD Countries: Coupled or Decoupled?

2019 ◽  
Vol 34 (1) ◽  
pp. 99-117
Author(s):  
Huh Taewook
Keyword(s):  
Sustainable Development ◽  
Oecd Countries ◽  
The Other ◽  
Type Analysis ◽  
Ideal Types ◽  
Type 3 ◽  
Relationship Of ◽  
The Relationship

This study attempts to analyze to what extent governance and sustainable development (SD) empirically appear compatible in the thirtyfive OECD countries through the fuzzy-set ideal type analysis, and identify which ideal types appear coupled or decoupled, and then reveal which countries belong to the coupled types or to the decoupled types. In short, twenty-two countries (including Sweden (fuzzy score, 0.953), Denmark (0.920), Finland (0.914), Norway (0.911) in Type 1 (G*S, ‘strong G-S coupled countries’); and Turkey (0.906), Greece (0.833), Mexico (0.828) in Type 4 (g*s, ‘lite g-s coupled countries’) are in line with the accepted conventions regarding the compatible relationship between governance and SD. On the other hand, the rest of thirteen countries (including USA (fuzzy score, 0.815), Luxembourg (0.721), Australia (0.660) in Type 2 (G*s, ‘G-s decoupled countries’); and Slovenia (0.728), France (0.644), Czech Rep. (0.625) in Type 3 (g*S, ‘g-S decoupled countries’) may indicate that the relationship of governance and SD is in fact experiencing tensions in the national contexts. These findings are characterized by the substance (of SD) and procedure (of governance) divide. Considering the results, this study focuses on the idea of reflexivity or reflexive capacity.

Interpersonal Conflicts in the Relationship of Twins

1998 ◽  
Vol 47 (3-4) ◽  
pp. 153-160
Author(s):  
S. A. Gruszewska
Keyword(s):  
Social Life ◽  
Interpersonal Conflict ◽  
The Other ◽  
Psychological Space ◽  
Interpersonal Conflicts ◽  
Educational Methods ◽  
The Moment ◽  
Relationship Of ◽  
The Relationship

AbstractTaking into consideration two facts: that the structure of social life forces twins to part and that the presented roles in a pair are not equal, (one of the twins plays the role of a leader (L) and the other, the subordinate (P.)), one can ask the question — what meaning does the moment of parting have and what are its consequences?In order to do that, a survey was conducted, (a sample of 31 pairs of twins above the age of 30), in which every pair was asked the question: “Which one of you made the decision about parting?” The answer had two options: A – I, B – brother/sister. Out of 31 pairs of twins, 16 pairs chose the variant different from his brother or sister – that is A, B, admitting that the interpersonal conflict was the result of the parting. In 7 pairs, both twins chose the B variant – they withdrew from the conflict; and in 8 pairs they chose the A variant – looking for a compromise as the means of agreement.When analyzing the results of the survey, we can state the following:– in the relationship of twins, there is an interpersonal conflict;– the decision about parting is difficult with prevalent feelings of sadness and sorrow;– after parting, at least one of the twins has problems with preserving his identity and integrity of psychological space.Since the moment of parting is necessary and difficult, specialists and mainly parents are required to consciously change their position towards the relationship of twins. It has to be the result of applied educational methods which aim at creating subjectivity and equality of each of the twins before the moment of parting.

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