Deterministic recognizability of picture languages with Wang automata

special issue dedicated to the second edition of the conference AutoMathA: from Mathematics to ApplicationsInternational audienceWe present a model of automaton for picture language recognition, called Wang automaton, which is based on labeled Wang tiles. Wang automata combine features of both online tessellation acceptors and 4-way automata: as in online tessellation acceptors, computation assigns states to each picture position; as in 4-way automata, the input head visits the picture moving from one pixel to an adjacent one, according to some scanning strategy. Wang automata recognize the class REC, i.e. they are equivalent to tiling systems or online tessellation acceptors, and hence strictly more powerful than 4-way automata. We also introduce a natural notion of determinism for Wang automata, and study the resulting class, extending the more traditional approach of diagonal-based determinism, used e. g. by deterministic tiling systems. In particular, we prove that the concept of row (or column) ambiguity defines the class of languages recognized by Wang automata directed by boustrophedonic scanning strategies

Perfectly quilted rectangular snake tilings

AbstractWe introduce a particular form of snake tilings to define picture languages, and relate the obtained family to the recognizable picture languages (as defined by Wang tiles). The correspondence for substitution tilings is even closer, and hence is applicable to the Hilbert curve

Characterizations of recognizable picture series

AbstractThe theory of two-dimensional languages as a generalization of formal string languages was motivated by problems arising from image processing and pattern recognition, and also concerns models of parallel computing. Here we investigate power series on pictures. These are functions that map pictures to elements of a semiring and provide an extension of two-dimensional languages to a quantitative setting. We assign weights to different devices, ranging from picture automata to tiling systems. We will prove that, for commutative semirings, the behaviours of weighted picture automata are precisely alphabetic projections of series defined in terms of rational operations, and also coincide with the families of series characterized by weighted tiling or weighted domino systems

Strategies to scan pictures with automata based on Wang tiles

Wang automata are devices for picture language recognition recently introduced by us, which characterize the class REC of recognizable picture languages. Thus, Wang automata are equivalent to tiling systems or online tessellation acceptors, and are based like Wang systems on labeled Wang tiles. The present work focus on scanning strategies, to prove that the ones Wang automata are based on are those following four kinds of movements: boustrophedonic, ``L-like'', ``U-like'', and spirals

Subshifts as Models for MSO Logic

We study the Monadic Second Order (MSO) Hierarchy over colourings of the discrete plane, and draw links between classes of formula and classes of subshifts. We give a characterization of existential MSO in terms of projections of tilings, and of universal sentences in terms of combinations of "pattern counting" subshifts. Conversely, we characterise logic fragments corresponding to various classes of subshifts (subshifts of finite type, sofic subshifts, all subshifts). Finally, we show by a separation result how the situation here is different from the case of tiling pictures studied earlier by Giammarresi et al.Comment: arXiv admin note: substantial text overlap with arXiv:0904.245

Picture languages generated by splicing and assembling til·les

Idiomes imatge generats per Empalme i Muntatge Rajoles. L'extensió de l'estudi de les llengües oficials sobre el cas string 2 idiomes dimensionals o idiomes imatge ha estat d'interès per molt temps per les seves vastes aplicacions. En la tesi i l'objecte de dues dimensions més comú estudiat és una imatge que és una matriu rectangular de símbols presos a partir d'un alfabet finit. L 'objectiu d'aquesta tesi se centra en l'estudi de la generació de les classes d'idiomes d'imatge per les operacions de bio-inspirats saber, `Enllaç' i` Auto-Assemblea 'd'ADN-Computing. És a dir, sistema d'entroncament i enrajolats Regla Sistemes H-Array. H-array Empalme Sistema és un formalisme bio-inspirat estès des H-entroncament de la caixa de cadena, un estudi àmpliament investigat introduït per T. Head. Està estructurat com un mecanisme mitjançant l'estudi de les gramàtiques lineals de dues dimensions correctes. Aquest formalisme és un mecanisme que s'aplica al número finit d'imatges trucades imatges inicials amb determinat conjunt de regles d'entroncament de dòmino de columna i fila. El lloc de context en el qual les dues imatges es tallen en columnes i files es va decidir per la seqüència de dòmino adjacents en el conjunt de regles. I llavors el `enganxar 'de la primera part de la imatge a la segona part de la imatge es realitza mitjançant la columna i fila concatenacions respectivament. L'H-Array Enllaç Sistemes s'aplica sobre llengües 2D-RLG generant idiomes Enllaç H-Array (HASL). A continuació, les classes de restricció definides i d'estudi són acte Creu sobre matrius i llenguatges Empalme matriu simples i resultats incomparables es va demostrar amb 2D-RLG, HASL. No són disjunts i es creuen llenguatges recognoscibles. El segon formalisme principal introduït i estudiat a la tesi és Revestiments Sistema de regles . Aquest formalisme genera la imatge pel conjunt de regles de mosaic, muntatge rajoles. Hem demostrat que la classe de L (TS) (Sistema d'enrajolat, llenguatge reconeixible) està continguda en TRuS. A més, vam demostrar existeixen una construcció del formalisme basat en la generació d'imatges en files o columnes que és equivalent a L (TS). L'equivalència es demostra l'ús de sistemes de Wang. Així que porta a una idea interessant d funcionament bio-inspirat (auto-acoblament) a la generació de la imatge.Idiomas de imagen generados por Empalme y Montaje Azulejos. La extensión del estudio de las lenguas oficiales sobre el caso string dos idiomas dimensionales o idiomas imagen ha sido de interés por mucho tiempo por sus vastas aplicaciones. En la tesis y el objeto de dos dimensiones más común estudiado es una imagen que es una matriz rectangular de símbolos tomados a partir de un alfabeto finito. E l objetivo de esta tesis se centra en el estudio de la generación de las clases de idiomas de imagen por las operaciones de bio-inspirados saber, `Empalme 'y` Auto-Asamblea' de ADN-Computing. A saber, sistema de empalme H-Array y sistemas de regla de mosaico. H-array Empalme Sistema es un formalismo bio-inspirado extendido desde H-empalme de la caja de cadena, un estudio ampliamente investigado introducido por T. Head. Está estructurado como un mecanismo mediante el estudio de las gramáticas lineales de dos dimensiones correctas. Este formalismo es un mecanismo que se aplica en el número finito de imágenes llamadas imágenes iniciales con determinado conjunto de reglas de empalme de dominó de columna y fila. El sitio de contexto en el que las dos imágenes se cortan en columnas y filas se decidió por la secuencia de dominós adyacentes en el conjunto de reglas. Y entonces el `pegar 'de la primera parte (o sub-array) de la imagen a la segunda parte de la imagen se realiza mediante la columna y fila concatenaciones respectivamente. El H-Array Empalme Sistemas se aplica sobre lenguas 2D-RLG generando idiomas Empalme H-Array (HASL). A continuación, las clases de restricciones definidas y de estudio son auto Cruz sobre matrices y lenguajes Empalme matriz simples y resultados incomparables se demostró con 2D-RLG, HASL. No son disjuntos y se cruzan lenguajes reconocibles. El segundo formalismo principal introducido y estudiado en la tesis son Revestimientos Sistema de reglas TRuS. Este formalismo genera la imagen por el conjunto de reglas de mosaico, montajes azulejos. Hemos demostrado que la clase de L (TS) (Sistema de alicatado, lenguaje reconocible) está contenida en la TRuS. Además, demostramos existen una construcción del formalismo basado en la generación de imágenes en filas o columnas que es equivalente a L (TS). La equivalencia se demuestra el uso de sistemas de Wang.Picture languages generated by Splicing and Assembling Tiles. The extension of the study of formal languages over string case to two dimensional languages or picture languages has been of interest for long for its vast applications. In the thesis and the most common two-dimensional object studied is a picture which is a rectangular array of symbols taken from a finite alphabet. T he objective of this thesis concentrates on the study of generation of Picture language classes by bio-inspired operations namely, `Splicing' and `Self-Assembly' of DNA-Computing. Namely, H-Array Splicing System and Tiling Rule Systems. H-array Splicing Systems is a bio-inspired formalism extended from H-Splicing from string case, a vastly investigated study introduced by T. Head. In particular it is structured as a mechanism by studying two-dimensional right linear grammars. In elaborate this formalism is a mechanism which is applied on finite number of pictures called initial pictures with given set of column and row domino splicing rules. The context site where the two pictures are cut in columns and rows are decided by the sequence of adjacent dominoes in the set of rules. And then the `pasting' of the first part (or sub-array) of the picture to the second part of the picture is done by column and row concatenations respectively. The H-Array Splicing Systems is applied over 2D-RLG languages generating H-Array Splicing languages (HASL). Then the restriction classes defined and study are Self Cross over Arrays and Simple Array Splicing languages and incomparable results are proved with 2D-RLG, HASL. They are not disjoint and they intersect Recognizable languages. Another and the second main formalism introduced and studied in the thesis is Tiling Rule System TRuS . This formalism generates picture by set of tiling rules, assembling tiles. We have proved that the class of L(TS) (Tiling System, recognizable language) is contained in TRuS . Also, we prove there exist a construct of the formalism based on generating pictures in rows or columns which is equivalent to L(TS). The equivalence is proved using Wang systems. Thus leading to an interesting notion of bio-inspired (self-assembling) operation to picture generation

Ensuring the authenticity of the conservation and reuse of modern industrial heritage architecture: a case study of the large machine factory, China

The Large Machine Factory (LMF) was built in the complex historical context of the late Qing Dynasty (1840–1912). Its space and construction faithfully record the architectural and cultural fusion between Chinese and western traditions and mark the beginning of modern architectural techniques in China. Through historical data and empirical studies, the historical background and architectural characteristics of the LMF were analyzed, and interventions aimed at ensuring authenticity were established. The cultural significance and results of construction were considered two crucial elements in terms of outstanding characteristics. Comprehensive inspection and assessment strategies were discussed, with minimal intervention and interpretation principles. Preventive reinforcement of the foundation, complementary reinforcement of the main structures, restoration of the historic façade and environment, and adaptive spatial interventions were found to be effective ways to ensure authenticity. The principles of minimal intervention and interpretability, which include prevention, recognizability, invisibility, subsidiarity, and intertextuality, were proposed through a comparison with the literature and practical experience. This study provides an appropriate technical reference for ensuring authenticity in the conservation and reuse of modern historic buildings with complex contexts. We propose a new understanding of intervention principles and suggest a guiding intervention path that avoids the complexities arising from the generalized interpretations of authenticity.Postprint (published version

Simulations for a Class of Two-Dimensional Automata

We study the notion of simulation over a class of automata which recognize 2D languages (languages of arrays of letters). This class of two-dimensional On-line Tessellation Automata (2OTA) accepts the same class of languages as the class of tiling systems, considered as the natural extension of classical regular word languages to the 2D case. We prove that simulation over 2OTA implies language inclusion. Even if the existence of a simulation relation between two 2OTA is shown to be an NP-complete problem in time, this is an important result since the inclusion problem is undecidable in general in this class of languages. Then we prove the existence in a given 2OTA of a unique maximal autosimulation relation, computable in polynomial time

Self-Assembly of Tiles: Theoretical Models, the Power of Signals, and Local Computing

DNA-based self-assembly is an autonomous process whereby a disordered system of DNA sequences forms an organized structure or pattern as a consequence of Watson-Crick complementarity of DNA sequences, without external direction. Here, we propose self-assembly (SA) hypergraph automata as an automata-theoretic model for patterned self-assembly. We investigate the computational power of SA-hypergraph automata and show that for every recognizable picture language, there exists an SA-hypergraph automaton that accepts this language. Conversely, we prove that for any restricted SA-hypergraph automaton, there exists a Wang Tile System, a model for recognizable picture languages, that accepts the same language. Moreover, we investigate the computational power of some variants of the Signal-passing Tile Assembly Model (STAM), as well as propose the concept of {\it Smart Tiles}, i.e., tiles with glues that can be activated or deactivated by signals, and which possess a limited amount of local computing capability. We demonstrate the potential of smart tiles to perform some robotic tasks such as replicating complex shapes