scholarly journals A tiling system for the class ofL-convex polyominoes

2013 ◽  
Vol 475 ◽  
pp. 73-81 ◽  
Author(s):  
S. Brocchi ◽  
A. Frosini ◽  
R. Pinzani ◽  
S. Rinaldi
Keyword(s):  
Tiling System

scholarly journals Generative Aspects of Oxide Pictures by Oxide Tile Rewriting Grammar

2019 ◽  
Vol 8 (3) ◽  
pp. 1537-1543
Keyword(s):  
Two Dimensions ◽  
Two Dimensional ◽  
Silicate Network ◽  
Oxygen Ions ◽  
Tiling System ◽  
Higher Dimensional ◽  
Picture Languages ◽  
Rectangular Grids ◽  
Rewriting Rules ◽  
Special Case

In formal languages, picture language is generalization of string language theory to two dimensions. Pictures which may be regarded as two-dimensional objects occur in studies concerning recognition of patterns, images and various computational fields. Several studies have been done for generating and/or recognizing higher dimensional objects using formal models. Tile rewriting grammar (TRG) is yet another model introduced for generating picture languages. TRG combines isometric rewriting rules with the Giammaresi and Restivo’s Tiling system. This rewriting grammar generates spirals, square and rectangular grids. The power of generating pictures by tile rewriting grammar is more than REC .Sweety et al have generated hexagonal pictures, introducing hexagonal Tile Rewriting Grammar. Kuberalet al have introduced Triangular Tile Rewriting Grammar to generate Triangular Pictures. A special class of objects namely Oxide pictures have been of interest recently. Oxide network is a special case of Silicate network. The silicates are a complicated class of minerals made up of tetrahedral silicates. A basic silicate tetrahedron unit SiO4 is formed with Oxygen ions in the corners and a Silicate ion in the center. In a two dimensional plane a ring of tetrahedrons that are shared by Oxygen nodes forms a silicate sheet.In this paper, Oxide Tile Rewriting Grammar (OXTRG) is proposed for generating Oxide pictures. The motivation for the study is derived from the Oxide network which is obtained by deleting all the silicon nodes of a silicate network. Closure properties of OXTRG are discussed. When compared with schemes such as Oxide Tiling System and Oxide Sgraffito Automaton, OXTRG is found to be more powerful.

scholarly journals A stronger recognizability condition for two-dimensional languages

2013 ◽  
Vol Vol. 15 no. 2 (Automata, Logic and Semantics) ◽  
Author(s):  
Marcella Anselmo ◽  
Maria Madonia
Keyword(s):  
Finite Automata ◽  
The Other ◽  
Two Dimensional ◽  
Minimal Size ◽  
One Dimensional ◽  
Tiling System ◽  
International Audience ◽  
The One

Automata, Logic and Semantics International audience The paper presents a condition necessarily satisfied by (tiling system) recognizable two-dimensional languages. The new recognizability condition is compared with all the other ones known in the literature (namely three conditions), once they are put in a uniform setting: they are stated as bounds on the growth of some complexity functions defined for two-dimensional languages. The gaps between such functions are analyzed and examples are shown that asymptotically separate them. Finally the new recognizability condition results to be the strongest one, while the remaining ones are its particular cases. The problem of deciding whether a two-dimensional language is recognizable is here related to the one of estimating the minimal size of finite automata recognizing a sequence of (one-dimensional) string languages.

scholarly journals ON RECOGNIZABLE LANGUAGES OF INFINITE PICTURES

2004 ◽  
Vol 15 (06) ◽  
pp. 823-840 ◽  
Author(s):  
OLIVIER FINKEL
Keyword(s):  
Two Dimensional ◽  
Infinite Words ◽  
Tiling System ◽  
Tiling Systems ◽  
System Acceptance ◽  
Recognizable Language

In a recent paper, Altenbernd, Thomas and Wöhrle have considered acceptance of languages of infinite two-dimensional words (infinite pictures) by finite tiling systems, with the usual acceptance conditions, such as the Büchi and Muller ones, firstly used for infinite words. The authors asked for comparing the tiling system acceptance with an acceptance of pictures row by row using an automaton model over ordinal words of length ω2. We give in this paper a solution to this problem, showing that all languages of infinite pictures which are accepted row by row by Büchi or Choueka automata reading words of length ω2 are Büchi recognized by a finite tiling system, but the converse is not true. We give also the answer to two other questions which were raised by Altenbernd, Thomas and Wöhrle, showing that it is undecidable whether a Büchi recognizable language of infinite pictures is E-recognizable (respectively, A-recognizable).

scholarly journals Holographic Near-Eye 3D Display Method Based on Large-Size Hologram

2021 ◽  
Vol 8 ◽  
Author(s):  
Su-Juan Liu ◽  
Ning-Tao Ma ◽  
Ping-Ping Li ◽  
Di Wang
Keyword(s):  
Incident Angle ◽  
Linear Structure ◽  
Reconstructed Image ◽  
Spatial Light Modulators ◽  
Image Point ◽  
Viewing Angle ◽  
3D Display ◽  
Light Modulators ◽  
Large Size ◽  
Tiling System

In this paper, we propose a holographic near-eye 3D display method based on large-size computer-generated hologram (CGH). The reconstructed image with a large viewing angle is obtained by using a time multiplexing and spatial tiling system. The large-size CGHs are generated and they record the information of the 3D object from different angles. The CGHs are reproduced at different moments. For a certain reconstructed moment, three spatial light modulators (SLMs) spatially spliced into a linear structure are used to load a single CGH. The diffraction boundary angle of the reconstructed light forming each image point is equal to the maximum diffraction angle of the SLM, so the viewing angle of the image generated by the CGH is enlarged. For different CGHs, the incident angle of reconstructed light is changed. Through time multiplexing, the reconstructed images of the CGHs are combined into a reconstructed image whose viewing angle is further enlarged. Due to the large viewing angle of the reconstructed image, the proposed method has unique advantages in near-eye display. The feasibility of the proposed method is proved by experimental results.

scholarly journals Impact of Environmental Exposure on the Service Life of Façade Claddings—A Statistical Analysis

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 615
Author(s):  
Joana Barrelas ◽  
Ilídio S. Dias ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Inês Flores-Colen ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Service Life ◽  
Environmental Exposure ◽  
Degradation Process ◽  
Related Factors ◽  
High Exposure ◽  
Tiling System ◽  
Building Components ◽  
The Impact ◽  
Exposure Conditions

Façade claddings, as the outer protection layer of the building’s envelope, are directly exposed to environmental degradation agents. The façades’ orientation and their distance from the sea, among other location and protection-related factors, influence their vulnerability to climate loads, in particular wind and air humidity. These loads, as well as exposure to air pollution, affect the degradation process of claddings and the durability of façades. Therefore, studying the impact of the environmental exposure conditions on the service life of different external claddings provides useful information on their performance over time, which can support (i) decision-makers in the selection of the best façade cladding solutions and (ii) further research on the impact of climate change on building components. This study covers six types of cladding: rendered façades (R), natural stone cladding (NSC), ceramic tiling system (CTS), painted surfaces (PS), external thermal insulation composite systems (ETICS), and architectural concrete façades (ACF). Three hundred façades located in Portugal are analysed according to three main groups of variables, which characterize (i) the façades, (ii) their degradation condition, and (iii) the environmental deterioration loads and context. The statistical analysis results reveal that the environmental variables affect the cladding degradation process. South-oriented façades present lower degradation conditions than façades facing north. The distance from the sea and high exposure to pollutants add to the degradation conditions, reducing the expected service life of façades. The results reveal that claddings can be organized according to two main groups: the most durable (CTS, NSC, and ACF) and the least durable (R, PS, and ETICS) systems. This study enables a comprehensive analysis of the data, useful to draw conclusions about the influence of environmental exposure conditions on the degradation and service life of façade claddings.

scholarly journals MOSEV: a global burn severity database from MODIS (2000–2020)

2021 ◽  
Vol 13 (5) ◽  
pp. 1925-1938
Author(s):  
Esteban Alonso-González ◽  
Víctor Fernández-García
Keyword(s):  
Correlation Coefficients ◽  
Burn Severity ◽  
Burned Area ◽  
Landsat 8 ◽  
Surface Reflectance ◽  
Global Database ◽  
Tiling System ◽  
Time To Build ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
The Difference

Abstract. To make advances in the fire discipline, as well as in the study of CO2 emissions, it is of great interest to develop a global database with estimators of the degree of biomass consumed by fire, which is defined as burn severity. In this work we present the first global burn severity database (MOSEV database), which is based on Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance and burned area (BA) products from November 2000 to near real time. To build the database we combined Terra MOD09A1 and Aqua MYD09A1 surface reflectance products to obtain dense time series of the normalized burn ratio (NBR) spectral index, and we used the MCD64A1 product to identify BA and the date of burning. Then, we calculated for each burned pixel the difference of the NBR (dNBR) and its relativized version (RdNBR), as well as the post-burn NBR, which are the most commonly used burn severity spectral indices. The database also includes the pre-burn NBR used for calculations, the date of the pre- and post-burn NBR, and the date of burning. Moreover, in this work we have compared the burn severity metrics included in MOSEV (dNBR, RdNBR and post-burn NBR) with the same ones obtained from Landsat-8 scenes which have an original resolution of 30 m. We calculated the Pearson's correlation coefficients and the significance of the relationships using 13 pairs of Landsat scenes randomly distributed across the globe, with a total BA of 6904 km2 (n=32 163). Results showed that MOSEV and Landsat-8 burn severity indices are highly correlated, particularly the post-burn NBR (R=0.88; P<0.001), and dNBR (R=0.74; P<0.001) showed stronger relationships than RdNBR (R=0.42; P<0.001). Differences between MOSEV and Landsat-8 indices are attributable to variability in reflectance values and to the different temporal resolution of both satellites (MODIS: 1–2 d; Landsat: 16 d). The database is structured according to the MODIS tiling system and is freely downloadable at https://doi.org/10.5281/zenodo.4265209 (Alonso-González and Fernández-García, 2020).

Image-tiling system using optically addressed spatial light modulator for high-resolution and multiview 3D display

2000 ◽  
Author(s):  
Hyung-Wook Jeon ◽  
Adrian R. L. Travis ◽  
Neil Collings ◽  
Tim D. Wilkinson ◽  
Y. Frauel
Keyword(s):  
High Resolution ◽  
Spatial Light Modulator ◽  
3D Display ◽  
Light Modulator ◽  
Tiling System
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