GPGPU Computing for Microscopic Simulations of Crowd Dynamics

We compare GPGPU implementations of two popular models of crowd dynamics. Specifically, we consider a continuous social force model, based on differential equations (molecular dynamics) and a discrete social distances model based on non-homogeneous cellular automata. For comparative purposes both models have been implemented in two versions: on the one hand using GPGPU technology, on the other hand using CPU only. We compare some significant characteristics of each model, for example: performance, memory consumption and issues of visualization. We also propose and test some possibilities for tuning the proposed algorithms for efficient GPU computations

Using shared memory as a cache in high performance cellular automata water flow simulations

Graphics processors (GPU -- Graphic Processor Units) recently have gained a lot of interest as an efficient platform for general-purpose computation. Cellular Automata approach which is inherently parallel gives the opportunity to implement high performance simulations. This paper presents how shared memory in GPU can be used to improve performance for Cellular Automata models. In our previous works, we proposed algorithms for Cellular Automata model that use only a GPU global memory. Using a profiling tool, we found bottlenecks in our approach. We introduce modifications that takes an advantage of fast shared memory. The modified algorithm is presented in details, and the results of profiling and performance test are demonstrated. Our unique achievement is comparing the efficiency of the same algorithm working with a global and shared memory

Informatyczne modele wzrostu w wybranych zagadnieniach geologii : rozprawa doktorska /

Recenzenci pracy: Robert Schaefer, Ryszard Tadeusiewicz.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2005.Bibliogr. k. 141-155.Metodologia obliczeń, współczesne systemy obliczeniowe, rozwój modelowania komputerowego, problemy geologii, modelowanie komputerowe, systemów złożonych, lokalność oddziaływań, sąsiedztwo w automacie komórkowym, siatka automatu komórkowego, formalna definicja, synchroniczny, asynchroniczny, ciągły automat komórkowy, homogeniczny, niehomogeniczny, warunki brzegowe, nieodwracalność, równoległość, automaty komórkowe, równania różniczkowe cząstkowe, reprezentacja przy pomocy grafu, zastosowania, rozszerzenia koncepcji L-systemów, modelowanie transportu w L-systemach, tablicowe L-systemy, kolonie, ekogramatyki, modelowanie wpływu środowiska, modelowanie sieci rzecznych, modele statystyczne, deterministyczne, optymalne sieci kanałów, rzeka anastomozująca, sieć transportowa w konsumującym środowisku, komputerowy model rzeki anastomozującej, model przepływu wody w terenie, formalna definicja automatu, algorytm, implementacja, wyniki symulacji, SCAMAN, MANGraCA, graf, model rozwoju rzeki anastomozującej, wzrostu rozgałęziającej się sieci transportowej, metody mierzenia złożoności struktur sieciowych, prawa skalowalności, klasyfikacja hydrograficzna, zastosowanie metod klasyfikacji hydrograficznej do ilościowej oceny wyników symulacji, model wzrostu szkieletu otwornicy, morfologia teoretyczna, komputerowe modelowanie wzrostu organizmów żywych, otwornic, otwornice, przegląd wcześniejszych modeli, w przestrzeni 2D, 3D, poszukiwania optymalnego położenia ujścia, zakres zabroniony, oś wzrostu, skalowanie alometryczne, model deterministyczny, z rozmyciem parametrów, parametry modelu, uwagi na temat implementacji modelu, morfoprzestrzeń modelu wzrostu otwornicy, kierunki dalszych badań, projekty badawcze, słownik poję

Using shared memory as a cache in cellular automata water flow simulations on GPUs

Tyt. z nagłówka.Bibliogr. s. 399-401.Graphics processors (GPU – Graphic Processor Units) recently have gained a lot of interest as an efficient platform for general-purpose computation. Cellular Automata approach which is inherently parallel gives the opportunity to implement high performance simulations. This paper presents how shared memory in GPU can be used to improve performance for Cellular Automata models. In our previous works, we proposed algorithms for Cellular Automata model that use only a GPU global memory. Using a profiling tool, we found bottlenecks in our approach. With this paper, we will introduce modifications that takes an advantage of fast shared memory. The modified algorithm is presented in details, and the results of profiling and performance test are demonstrated. Our unique achievement is comparing the efficiency of the same algorithm working with a global and shared memory.Dostępny również w formie drukowanej.KEYWORDS: Cellular Automata, GPU computation, modelling physical phenomena

eVolutus: A New Platform for Evolutionary Experiments

eVolutus is a new software platform designed for modeling evolutionary and population dynamics of living organisms. Single-celled eukaryotes, foraminifera, are selected as model organisms that have occupied the marine realm for at least 500 Ma and left an extraordinary fossil record preserved in microscopic shells. This makes them ideal objects for testing general evolutionary hypotheses based on studying multiscale genotypic, phenotypic, ecologic and macroevolutionary patterns. Our platform provides a highly configurable environment for conducting evolutionary experiments at various spatiotemporal scales

New, highly versatile bimolecular photoinitiating systems for free-radical, cationic and thiol–ene photopolymerization processes under low light intensity UV and visible LEDs for 3D printing application

1-Amino-4-methyl-naphthalene-2-carbonitrile derivatives are proposed for the role of photosensitizers of iodonium salt during the photopolymerization processes upon near UV-A and visible ranges. Remarkably, 1-amino-4-methyl-naphthalene-2-carbonitrile derivatives are highly versatile allowing access to photoinitiating systems for (i) the cationic photopolymerization of epoxide monomers with a ring opening mechanism and vinyl ether monomers with chain growth mechanisms (ii) the free-radical photopolymerization of acrylate monomers, (iii) the photopolymerization of interpenetrated polymer networks (IPNs) based on epoxide and acrylate monomers under air and under laminate in an oxygen-free atmosphere (iv) the thiol–ene photopolymerization processes. Excellent polymerization profiles are obtained during all types of photopolymerization processes. The initiation mechanisms are analyzed through steady state photolysis, cyclic voltammetry and fluorescence experiments. Moreover, the newly developed bimolecular photoinitiating systems were investigated by applying an additive manufacturing process under visible light sources. Furthermore, vat photopolymerization processes using IPN compositions, which are polymerizable by using new photoinitiating systems, provide high resolution and speeds. For these reasons, new bimolecular photoinitiating systems are promising initiators for photopolymerization-based 3D printing process to fabricate 3D structures

Form and function of F-actin during biomineralization revealed from live experiments on foraminifera

Although the emergence of complex biomineralized forms has been investigated for over a century, still little is known on how single cells control morphology of skeletal structures, such as frustules, shells, spicules, or scales. We have run experiments on the shell formation in foraminifera, unicellular, mainly marine organisms that can build shells by successive additions of chambers. We used live imaging to discover that all stages of chamber/shell formation are controlled by dedicated actin-driven pseudopodial structures. Successive reorganization of an F-actin meshwork, associated with microtubular structures, is actively involved in formation of protective envelope, followed by dynamic scaffolding of chamber morphology. Then lamellar dynamic templates create a confined space and control mineralization separated from seawater. These observations exclude extracellular calcification assumed in selected foraminiferal clades, and instead suggest a semiintracellular biomineralization pattern known from other unicellular calcifying and silicifying organisms. These results give a challenging prospect to decipher the vital effect on geochemical proxies applied to paleoceanographic reconstructions. They have further implications for understanding multiscale complexity of biomineralization and show a prospect for material science applications

Novel Formulations Containing Fluorescent Sensors to Improve the Resolution of 3D Prints

Three-dimensional printing in SLA (stereolithography) and DLP (digital light processing) technologies has recently been experiencing a period of extremely rapid development. This is due to the fact that researchers recognise the many advantages of 3D printing, such as the high resolution and speed of the modelling and printing processes. However, there is still a search for new resin formulations dedicated to specific 3D printers allowing for high-resolution prints. Therefore, in the following paper, the effects of dyes such as BODIPY, europium complex, and Coumarin 1 added to light-cured compositions polymerised according to the radical mechanism on the photopolymerisation process speed, polymerisation shrinkage, and the final properties of the printouts were investigated. The kinetics of the photopolymerisation of light-cured materials using real-time FT-IR methods, as well as printouts that tangibly demonstrate the potential application of 3D printing technology in Industry 4.0, were examined. These studies showed that the addition of dyes has an effect on obtaining fluorescent prints with good resolution