Percorrer por autor "Fachada,Nuno"
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Item Assessing the feasibility of OpenCL CPU implementations for agent-based simulations(AGENT-BASED MODELING, 2017-05) Fachada,Nuno; Rosa,Agostinho C.; Escola de Comunicação, Arquitetura, Artes e Tecnologias da InformaçãoAgent-based modeling (ABM) is a bottom-up modeling approach, where each entity of the system being modeled is uniquely represented as a self-determining agent. Large scale emergent behavior in ABMs is population sensitive. As such, it is advisable that the number of agents in a simulation is able to reflect the reality of the system being modeled. This means that in domains such as social modeling, ecology, and biology, systems can contain millions or billions of individuals. Such large scale simulations are only feasible in non-distributed scenarios when the computational power of commodity processors, such as GPUs and multi-core CPUs, is fully exploited. In this paper we evaluate the feasibility of using CPU-oriented OpenCL for high-performance simulations of agent-based models. We compare a CPU-oriented OpenCL implementation of a reference ABM against a parallel Java version of the same model. We show that there are considerable gains in using CPU-based OpenCL for developing and implementing ABMs, with speedups up to 10x over the parallel Java version on a 10-core hyper-threaded CPU.Item Enlarged PLIN5-uncoated lipid droplets in inner regions of skeletal muscle type II fibers associate with type 2 diabetes(Edições Universitárias Lusófonas, 2022-02) Fachada,Vasco; Rahkila,Paavo; Fachada,Nuno; Turpeinen,Tuomas; Kujala,Urho M.; Kainulainen,Heikki; Faculdade de EngenhariaSkeletal muscle physiology remains of paramount importance in understanding insulin resistance. Due to its high lipid turnover rates, regulation of intramyocellular lipid droplets (LDs) is a key factor. Perilipin 5 (PLIN5) is one of the most critical agents in such regulation, being often referred as a protector against lipotoxicity and consequent skeletal muscle insulin resistance. We examined area fraction, size, subcellular localization and PLIN5 association of LDs in two fiber types of type 2 diabetic (T2D), obese (OB) and healthy (HC) individuals by means of fluorescence microscopy and image analysis. We found that T2D type II fibers have a significant sub-population of large and internalized LDs, uncoated by PLIN5. Based on this novel result, additional hypotheses for the pathophysiology of skeletal muscle insulin resistance are formulated, together with future research directions. Keywords: Lipid droplets, PLIN5, Type II diabetes, Skeletal muscle, Insulin resistance, Fiber typeItem A method for detecting statistically significant differences in EEG data(OHBM, 2017) Fachada,Nuno; Cruz,Janir R. da; Herzog,Michael H.; Figueiredo,Patrícia; Rosa,Agostinho C.; Escola de Comunicação, Arquitetura, Artes e Tecnologias da InformaçãoThe highly multivariate nature of EEG data often limits the search for statistically significant differences in data collected from two or more groups of subjects. We have recently developed a new technique for assessing whether two or more multidimensional samples are drawn from the same distribution. Here, we apply this to EEG data collected from schizophrenia patients and healthy controls while performing a Visual Backward Masking (VBM) task.Item Particle swarm and population structure(ACM, 2018) Fernandes,Carlos M.; Rosa,Agostinho C.; Fachada,Nuno; Laredo,Juan L. J.; Merelo,J. J.; Escola de Comunicação, Arquitetura, Artes e Tecnologias da InformaçãoWe investigate the convergence speed, accuracy, robustness and scalability of PSOs structured by regular and random graphs with 3 ≤ k ≤ n. The main conclusion is that regular and random graphs with the same averaged connectivity k may result in significantly different performance, namely when k is low.Item Procedural generation of 3D maps with snappable meshes(IEEE, 2022-04-20) Silva,Rafael Castro e; Fachada,Nuno; Andrade,Diogo de; Códices,Nélio; Faculdade de EngenhariaIn this paper we present a technique for procedurally generating 3D maps using a set of premade meshes which snap together based on designer-specified visual constraints. The proposed approach avoids size and layout limitations, offering the designer control over the look and feel of the generated maps, as well as immediate feedback on a given map’s navigability. A prototype implementation of the method, developed in the Unity game engine, is discussed, and a number of case studies are analyzed. These include a multiplayer game where the method was used, together with a number of illustrative examples which highlight various parameterizations and piece selection methods. The technique can be used as a designer-centric map composition method and/or as a prototyping system in 3D level design, opening the door for quality map and level creation in a fraction of the time of a fully human-based approach. INDEX TERMS : 3D maps, computer games, designer-centric methods, layout, procedural content generation (PCG).Item Unity Snappable Meshes(Elsevier, 2022-08-01) Fachada,Nuno; Silva,Rafael Castro e; Andrade,Diogo de; Códices,Nélio; Faculdade de EngenhariaThe Snappable Meshes algorithm procedurally generates 3D maps for computer games by iteratively selecting and linking pre-built map pieces via designer-specified connectors. In this paper we present an implementation of this algorithm in the Unity game engine, describing its architecture and discussing core implementational solutions. A number of examples illustrate the potential of the algorithm and the capabilities of the software. We assess the application’s impact on past and ongoing research, and how it can be improved to support future research questions. Keywords: Procedural content generation (PCG) ; Computer games ; Layout ; Designer-centric methods ;3D maps ; Unity game engine