Wyniki wyszukiwania - BazTech

1

Monitoring and forecasting spatio-temporal LULC for Akure rainforest habitat in Nigeria

Aliyu Yahaya A, Youngu Terwase T., Abubakar Aliyu Z., Bala Adamu, Jesulowo Christianah I.

Reports on Geodesy and Geoinformatics

|

2020

|

Vol. 110

29--38

EN

For several decades, Nigerian cities have been experiencing a decline in their biodiversity resulting from rapid land use land cover (LULC) changes. Anticipating short/long-term consequences, this study hypothesised the effects of LULC variables in Akure, a developing tropical rainforest city in south-west Nigeria. A differentiated trend of urban LULC was determined over a period covering 1999–2019. The study showed the net change for bare land, built-up area, cultivated land, forest cover and grassland over the two decades to be -292.68 km2, +325.79 km2, +88.65 km2, +8.62 km2 and -131.38 km2, respectively. With a projected population increase of about 46.85%, the study identified that the built-up land cover increased from 1.98% to 48.61%. The change detection analysis revealed an upsurge in built area class. The expansion indicated a significant inverse correlation with the bare land class (50.97% to 8.66%) and grassland class (36.33% to 17.94%) over the study period. The study observed that the land consumption rate (in hectares) steadily increased by 0.00505, 0.00362 and 0.0687, in the year 1999, 2009 and 2019, respectively. This rate of increase is higher than studies conducted in more populated cities. The Cellular Automata (CA) Markovian analysis predicted a 37.92% growth of the study area will be the built-up area in the next two decades (2039). The 20-year prediction for Akure built-up area is within range when compared to CA Markov prediction for other cities across the globe. The findings of this study will guide future planning for rational LULC

2

Sphere packing algorithm for the generation of digital models of polycrystalline microstructures with heterogeneous grain sizes

Hajder Lucyna, Madej Łukasz

Computer Methods in Materials Science

|

2020

|

Vol. 20, No. 1

22--30

EN

Development of the cellular automata (CA) sphere packing algorithm dedicated to the generation of two- and three-dimensional digital, synthetic microstructure models with heterogenous grain size distribution is presented within the paper. The synthetic microstructure model is generated in four major steps: generation of 2D/3D cellular automata computational domain, generation of circles/spheres with a required size distribution, close-packed filling of the computational domain with generated circles/spheres, growth of the circles/spheres according to the unconstrained CA growth algorithm. As a result, synthetic microstructure models with specific, required grain size distribution described by e.g. uni- or bimodal one are obtained. To reduce computational complexity and decrease execution time, the rotation of the circles/spheres during the packing stage is based on the vector accounting for the distance from computational domain borders and other spheres. The CA grain growth algorithm is also implemented using threads mechanism allowing parallel execution of computations to increase its efficiency. The developed algorithm with the implementation details as well as a set of examples of obtained results are presented within the paper.

PL

W pracy przedstawiono opracowanie algorytmu pakowania sferycznego automatu komórkowego (CA) dedykowanego do generowania dwu- i trójwymiarowych, cyfrowych, syntetycznych modeli mikrostruktury o niejednorodnym rozkładzie ziarnistości. Syntetyczny model mikrostruktury jest generowany w czterech głównych etapach: generowanie domeny obliczeniowej automatu komórkowego 2D/3D, generowanie okręgów/kul o wymaganym rozkładzie wielkości, wypełnianie domeny obliczeniowej wygenerowanymi okręgami/kulami, wzrost okręgów/kul zgodnie z algorytmem nieograniczonego wzrostu CA. W rezultacie otrzymujemy syntetyczne modele mikrostruktury o specyficznym, wymaganym rozkładzie uziarnienia opisanym np. jedno- lub dwumodalnym rozkładem. Aby zmniejszyć złożoność obliczeniową i skrócić czas wykonania, rotacja kół/kul podczas etapu pakowania opiera się na wektorowym rozliczaniu odległości od granic domen obliczeniowych z innymi sferami. Algorytm wzrostu ziarna CA jest również zaimplementowany z wykorzystaniem mechanizmu wątków, co pozwala na równoległe wykonywanie obliczeń w celu zwiększenia jego wydajności. W artykule przedstawiono opracowany algorytm wraz ze szczegółami implementacji oraz zestawem przykładów uzyskanych wyników.

3

Improving the effectivity of urban freight transport by means of cellular automata simulations

Kijewska K., Małecki K.

Archives of Transport System Telematics

|

2020

|

Vol. 13, iss. 1

20--25

EN

Unloading bays are one of the most popular and simple to implement solutions to support development of sustainable urban freight transport systems. The solution is aimed at reducing congestion on busy city streets, which is often caused by freight vehicles that, in an attempt to load or unload their cargoes, park directly in traffic lanes. Where dedicated unloading bays are in place, the traffic is undisturbed, which helps to prevent extra consumption of energy and fuel, and thus extra pollution, and which also makes it possible to avoid wasting time in traffic jams and ensuing costs. Therefore, the major benefit derived from this solution is its contribution to reduction of traffic congestion, followed by a perceptible decrease in pollutant emissions. This article aims at developing an algorithm for recommended distribution of unloading bays based on the reported locations of delivery points and parameters related to varied quantities of goods and the number of available parking spaces in the vicinity of unloading bays. Additionally, it addresses the issue of using unloading bays as EV charging stations. The proposed solution was implemented on the basis of a dedicated road traffic simulator based on the original cellular automaton model..

4

Symulacje propagacji pęknięć w materiałach ceramicznych metodą ruchomych automatów komórkowych

Czopor J., Rybaczuk M.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

|

2003

|

Z. 78

99-106

PL

W pracy przedstawiono algorytm symulacji metodą ruchomych automatów komórkowych zmian struktury materiałów wywołanej zewnętrznymi obciążeniami. Ograniczono się do przypadku dwuwymiarowego oraz stosunkowo niewielkiej liczby automatów komórkowych.

EN

Paper presents simulations of changes of internal structure of material due to external loads. Calculations were done with the help of movable cellular automata. Model has been confined to the two-dimensinal case with limited number of automatas.

5

Jednowymiarowy rozmyty automat komórkowy modelujący ruch drogowy

Burzyński M., Kosiński W.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

|

2002

|

Z. 76

143-151

PL

W pracy przedstawiono jednowymiarowy automat komórkowy, z regułami rozmytymi do modelowania jednowymiarowego, jednokierunkowego ruchu drogowego. Wyniki przeprowadzonych symulacji są zgodne z tzw. diagramem fundamentalnym (przepływność vs gęstość), opartym na przeprowadzonych rzeczywistych obserwacjach i pomiarach ruchu drogowego. Sterowanie rozmyte pozwala na wierne oddanie indywidualnych cech kierowcy, co wprowadza nową jakość w modelowaniu ruchu drogowego i stanowi obiecujący punkt odniesienia w dalszych badaniach rozpatrywanego zagadnienia.

EN

A discrete automation with fuzzy rules to simulate one-way traffic flow is introduced. Results of simulations are consistent with the so-called fundamental diagram (flow versus density), as is observed in the real free-way traffic. Fuzzy controller approach makes possible to include driver's individual characteristics and provides a new point of view in the further traffic flow research.