scholarly journals Theoretical and Practical Aspects Related to the Avoidability of Patterns in Words

2019 ◽  
Author(s):  
Kamelia Reshadi
Keyword(s):  
Computer Program ◽  
Constraint Satisfaction ◽  
Major Part ◽  
Constraint Satisfaction Problems ◽  
Final Part ◽  
Combinatorics On Words ◽  
Sat Solvers ◽  
The Past ◽  
The One ◽  
Avoidance Problem

This thesis concerns repetitive structures in words. More precisely, it contributes to studying appearance and absence of such repetitions in words. In the first and major part of this thesis, we study avoidability of unary patterns with permutations. The second part of this thesis deals with modeling and solving several avoidability problems as constraint satisfaction problems, using the framework of MiniZinc. Solving avoidability problems like the one mentioned in the past paragraph required, the construction, via a computer program, of a very long word that does not contain any word that matches a given pattern. This gave us the idea of using SAT solvers. Representing the problem-based SAT solvers seemed to be a standardised, and usually very optimised approach to formulate and solve the well-known avoidability problems like avoidability of formulas with reversal and avoidability of patterns in the abelian sense too. The final part is concerned with a variation on a classical avoidance problem from combinatorics on words. Considering the concatenation of i different factors of the word w, pexp_i(w) is the supremum of powers that can be constructed by concatenation of such factors, and RTi(k) is then the infimum of pexp_i(w). Again, by checking infinite ternary words that satisfy some properties, we calculate the value RT_i(3) for even and odd values of i.

scholarly journals Experimental Matching of Instances to Heuristics for Constraint Satisfaction Problems

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Jorge Humberto Moreno-Scott ◽  
José Carlos Ortiz-Bayliss ◽  
Hugo Terashima-Marín ◽  
Santiago Enrique Conant-Pablos
Keyword(s):  
Artificial Intelligence ◽  
Constraint Satisfaction ◽  
Operations Research ◽  
Special Interest ◽  
Research Community ◽  
Constraint Satisfaction Problems ◽  
The Past ◽  
Variable Ordering ◽  
Instance Space ◽  
Variable Ordering Heuristics

Constraint satisfaction problems are of special interest for the artificial intelligence and operations research community due to their many applications. Although heuristics involved in solving these problems have largely been studied in the past, little is known about the relation between instances and the respective performance of the heuristics used to solve them. This paper focuses on both the exploration of the instance space to identify relations between instances and good performing heuristics and how to use such relations to improve the search. Firstly, the document describes a methodology to explore the instance space of constraint satisfaction problems and evaluate the corresponding performance of six variable ordering heuristics for such instances in order to find regions on the instance space where some heuristics outperform the others. Analyzing such regions favors the understanding of how these heuristics work and contribute to their improvement. Secondly, we use the information gathered from the first stage to predict the most suitable heuristic to use according to the features of the instance currently being solved. This approach proved to be competitive when compared against the heuristics applied in isolation on both randomly generated and structured instances of constraint satisfaction problems.

scholarly journals A Variable Depth Search Algorithm for Binary Constraint Satisfaction Problems

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
N. Bouhmala
Keyword(s):  
Constraint Satisfaction ◽  
Optimization Problems ◽  
Search Algorithm ◽  
Wide Spectrum ◽  
Constraint Satisfaction Problem ◽  
Practical Interest ◽  
Constraint Satisfaction Problems ◽  
Variable Depth ◽  
The Past ◽  
Binary Constraint

The constraint satisfaction problem (CSP) is a popular used paradigm to model a wide spectrum of optimization problems in artificial intelligence. This paper presents a fast metaheuristic for solving binary constraint satisfaction problems. The method can be classified as a variable depth search metaheuristic combining a greedy local search using a self-adaptive weighting strategy on the constraint weights. Several metaheuristics have been developed in the past using various penalty weight mechanisms on the constraints. What distinguishes the proposed metaheuristic from those developed in the past is the update ofkvariables during each iteration when moving from one assignment of values to another. The benchmark is based on hard random constraint satisfaction problems enjoying several features that make them of a great theoretical and practical interest. The results show that the proposed metaheuristic is capable of solving hard unsolved problems that still remain a challenge for both complete and incomplete methods. In addition, the proposed metaheuristic is remarkably faster than all existing solvers when tested on previously solved instances. Finally, its distinctive feature contrary to other metaheuristics is the absence of parameter tuning making it highly suitable in practical scenarios.

scholarly journals Local Consistency and SAT-Solvers

2012 ◽  
Vol 43 ◽  
pp. 329-351 ◽  
Author(s):  
P. Jeavons ◽  
J. Petke
Keyword(s):  
Constraint Satisfaction ◽  
Constraint Programming ◽  
Inference Rule ◽  
Constraint Satisfaction Problem ◽  
Constraint Satisfaction Problems ◽  
Fixed Size ◽  
Local Consistency ◽  
Sat Solvers ◽  
Clause Learning ◽  
Do So

Local consistency techniques such as k-consistency are a key component of specialised solvers for constraint satisfaction problems. In this paper we show that the power of using k-consistency techniques on a constraint satisfaction problem is precisely captured by using a particular inference rule, which we call negative-hyper-resolution, on the standard direct encoding of the problem into Boolean clauses. We also show that current clause-learning SAT-solvers will discover in expected polynomial time any inconsistency that can be deduced from a given set of clauses using negative-hyper-resolvents of a fixed size. We combine these two results to show that, without being explicitly designed to do so, current clause-learning SAT-solvers efficiently simulate k-consistency techniques, for all fixed values of k. We then give some experimental results to show that this feature allows clause-learning SAT-solvers to efficiently solve certain families of constraint problems which are challenging for conventional constraint-programming solvers.

scholarly journals Esegiël 33 as wentelpunt in die boek van Esegiël

2012 ◽  
Vol 46 (1) ◽  
Author(s):  
Herrie F. Van Rooy
Keyword(s):  
Major Part ◽  
Personal Responsibility ◽  
Final Part ◽  
People Of God ◽  
Pivotal Point ◽  
The People ◽  
The One

Baie geleerdes het Esegiël as die inleiding tot die laaste groot gedeelte van die boek (Eseg 33–48) beskou, met terugverwysing na die eerste gedeelte van die boek (Eseg 1–24). Esegiël 33:1–20 het op verskillende maniere gebruik gemaak van en voortgebou op gedeeltes wat vroeër in die boek voorgekom het, veral die gedeeltes wat oor die roeping van die profeet in Esegiël 1–3 handel, asook Esegiël 18 wat die mens se persoonlike verantwoordelikheid beklemtoon. Die voorstel wat in hierdie artikel gemaak is, is dat die hoofstuk in die finale vorm van die boek ’n wentelfunksie het, om aan die een kant kortliks die boodskap van die profeet voor die val van Jerusalem saam te vat, maar om ook die leser vir die boodskap van Esegiël 34–48 voor te berei. Die twee uitsprake in Esegiël 33:23–33 dui op die toestand van die mense in Jerusalem, asook van die mense in ballingskap. Dit dui dus op die toestand van die twee groepe mense teen die tyd van die val van Jerusalem. Hierdie gedeeltes, soos ook die beklemtoning van die mens se verantwoordelikheid met die moontlikheid van bekering en herstel, antisipeer die boodskap van verlossing en herstel wat op Esegiël 33 sou volg.Ezekiel 33 as pivotal point in the book of Ezekiel. Many scholars regarded Ezekiel as the introduction to the last major part of the book (Ezk 33–48), with references to the first part of the book (Ezk 1–24). Ezekiel 33:1–20 made use, in diverse ways, of previous sections in the book, especially the sections dealing with the call of the prophet in Ezekiel 1–2, as well as Ezekiel 18, with its emphasis on the personal responsibility of the people of God. The proposal of this article was that the chapter served as a pivotal point in the final form of the book. On the one hand it summarised the message of the first part of the book, but it also prepared the people for the message of the final part of the book. The two oracles in Ezekiel 33:23–22 pointed to the circumstances of the people in Jerusalem, as well as that of the exiles, at the time of the fall of Jerusalem. These oracles and the emphasis on the personal responsibility of the people pointed to the message of salvation and restoration following in Ezekiel 34–48.

Al-Rasm al-ʿUthmānī: Towards Correct Pronunciation and the Preclusion of Ambiguity

2011 ◽  
Vol 13 (2) ◽  
pp. 201-171
Author(s):  
Nāṣir Al-Dīn Abū Khaḍīr
Keyword(s):  
Specific Pattern ◽  
Writing Style ◽  
The Third ◽  
The Past ◽  
Different Ages ◽  
Correct Pronunciation ◽  
The One ◽  
The Mind

The ʿUthmānic way of writing (al-rasm al-ʿUthmānī) is a science that specialises in the writing of Qur'anic words in accordance with a specific ‘pattern’. It follows the writing style of the Companions at the time of the third caliph, ʿUthmān b. ʿAffān, and was attributed to ʿUthmān on the basis that he was the one who ordered the collection and copying of the Qur'an into the actual muṣḥaf. This article aims to expound on the two fundamental functions of al-rasm al-ʿUthmānī: that of paying regard to the ‘correct’ pronunciation of the words in the muṣḥaf, and the pursuit of the preclusion of ambiguity which may arise in the mind of the reader and his auditor. There is a further practical aim for this study: to show the connection between modern orthography and the ʿUthmānic rasm in order that we, nowadays, are thereby able to overcome the problems faced by calligraphers and writers of the past in their different ages and cultures.

TARP DVIEJŲ KOLONŲ: XVIII A. PABAIGOS – XIX A. PRADŽIOS VILNIAUS MASONŲ KASDIENYBĖ SIMBOLIKOJE

2018 ◽  
pp. 144-163
Author(s):  
Daiva Milinkevičiūtė
Keyword(s):  
Daily Life ◽  
The Other ◽  
Daily Routine ◽  
The Past ◽  
Secular World ◽  
National Characteristics ◽  
Conservative Christian ◽  
The Subject ◽  
The One ◽  
Craft Guilds

The Age of Enlightenment is defined as the period when the universal ideas of progress, deism, humanism, naturalism and others were materialized and became a golden age for freemasons. It is wrong to assume that old and conservative Christian ideas were rejected. Conversely, freemasons put them into new general shapes and expressed them with the help of symbols in their daily routine. Symbols of freemasons had close ties with the past and gave them, on the one hand, a visible instrument, such as rituals and ideas to sense the transcendental, and on the other, intense gnostic aspirations. Freemasons put in a great amount of effort to improve themselves and to create their identity with the help of myths and symbols. It traces its origins to the biblical builders of King Solomon’s Temple, the posterity of the Templar Knights, and associations of the medieval craft guilds, which were also symbolical and became their link not only to each other but also to the secular world. In this work we analysed codified masonic symbols used in their rituals. The subject of our research is the universal Masonic idea and its aspects through the symbols in the daily life of the freemasons in Vilnius. Thanks to freemasons’ signets, we could find continuity, reception, and transformation of universal masonic ideas in the Lithuanian freemasonry and national characteristics of lodges. Taking everything into account, our article shows how the universal idea of freemasonry spread among Lithuanian freemasonry, and which forms and meanings it incorporated in its symbols. The objective of this research is to find a universal Masonic idea throughout their visual and oral symbols and see its impact on the daily life of the masons in Vilnius. Keywords: Freemasonry, Bible, lodge, symbols, rituals, freemasons’ signets.

The Invention of Papal History

2019 ◽  
Author(s):  
Stefan Bauer
Keyword(s):  
Catholic Reformation ◽  
History Writing ◽  
Historical Texts ◽  
The Past ◽  
History Of ◽  
Cultural Standards ◽  
Commissioned Works ◽  
The One ◽  
Late Renaissance ◽  
The Church

How was the history of post-classical Rome and of the Church written in the Catholic Reformation? Historical texts composed in Rome at this time have been considered secondary to the city’s significance for the history of art. The Invention of Papal History corrects this distorting emphasis and shows how history-writing became part of a comprehensive formation of the image and self-perception of the papacy. By presenting and fully contextualizing the path-breaking works of the Augustinian historian Onofrio Panvinio (1530–68), this book shows what type of historical research was possible in the late Renaissance and the Catholic Reformation. Historiography in this period by no means consisted entirely of commissioned works written for patrons; rather, a creative interplay existed between, on the one hand, the endeavours of authors to explore the past and, on the other hand, the constraints of patronage and ideology placed on them. This book sheds new light on the changing priorities, mentalities, and cultural standards that flourished in the transition from the Renaissance to the Catholic Reformation.

“Ambiguist” Statesmanship

Worldview ◽  
1960 ◽  
Vol 3 (9) ◽  
pp. 7-8
Author(s):  
Will Herberg
Keyword(s):  
Foreign Policy ◽  
Fixed Points ◽  
Natural Law ◽  
The Other ◽  
Moral Decision ◽  
Actual Situation ◽  
The Past ◽  
Mixed Feelings ◽  
Rational Mind ◽  
The One

John Courtney Murray's writing cannot fail to be profound and instructive, and I have profited greatly from it in the course of the past decade. But I must confess that his article, "Morality and Foreign Policy" (Worldview, May), leaves me in a strange confusion of mixed feelings. On the one hand, I can sympathize with what I might call the historical intention of the natural law philosophy he espouses, which I take to be the effort to establish enduring structures of meaning and value to serve as fixed points of moral decision in the complexities of the actual situation. On the other hand, I am rather put off by the calm assurance he exhibits when he deals with these matters, as though everything were at bottom unequivocally rational and unequivocally accessible to the rational mind. And I am really distressed at what seems to 3ie to be his woefully inadequate appreciation of the position of the "ambiguists," among whom I cannot deny I count myself.

scholarly journals From reflex to reflection: Moving from the space of causes to the space of reasons and back

2020 ◽  
Vol 3 (1) ◽  
pp. 681-693
Author(s):  
Ariel Furstenberg
Keyword(s):  
The Other ◽  
Final Part ◽  
Clear Cut ◽  
Other Hand ◽  
Space Of Reasons ◽  
The One ◽  
The Relationship ◽  
Simple Picture

AbstractThis article proposes to narrow the gap between the space of reasons and the space of causes. By articulating the standard phenomenology of reasons and causes, we investigate the cases in which the clear-cut divide between reasons and causes starts to break down. Thus, substituting the simple picture of the relationship between the space of reasons and the space of causes with an inverted and complex one, in which reasons can have a causal-like phenomenology and causes can have a reason-like phenomenology. This is attained by focusing on “swift reasoned actions” on the one hand, and on “causal noisy brain mechanisms” on the other hand. In the final part of the article, I show how an analogous move, that of narrowing the gap between one’s normative framework and the space of reasons, can be seen as an extension of narrowing the gap between the space of causes and the space of reasons.

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