Navegando por Assunto "Simulation"

Agora exibindo 1 - 15 de 15

Acesso aberto (Open Access)
Análise de handover a partir do uso de femtocells em redes LTE: abordagem baseada em simulação discreta
(Universidade Federal do Pará, 2014-06-13) SILVA, Ketyllen da Costa; FRANCÊS, Carlos Renato Lisboa; http://lattes.cnpq.br/7458287841862567
The volume of data traffic in mobile networks is growing exponentially. The explosion of mobile devices and applications in recent years has led to an overload of the network infrastructure responsible for disposing of this traffic, thus affecting the performance of the network as the user experience. One of the key elements in the networks (LTE) Long Term Evolution is the possibility of deploying multiple femtocells for the improvement of coverage and data rate. However, arbitrary overlapping coverage of these cells makes the handover mechanism complex and challenging. Thus, this dissertation proposes a methodology to study the impact of handover in LTE networks with femtocells. From a discrete simulation approach, the effects of the deployment of femtocells were evaluated. This study aimed to measure the impact and correlation of the use of femtocell parameters of QoS (Quality of Service) and performance indicators handover.
Acesso aberto (Open Access)
Avalanche como rede de percolação não homogênea
(Universidade Federal do Pará, 2019-09-13) SOUZA, Raimundo Nonato Carneiro de; TAVARES, Heliton Ribeiro; http://lattes.cnpq.br/1313373547379006; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Avalanches can be considered as a percolation process. This hypothesis will be posted to evaluate if this approach is possible and what are its advantages. Some literature speculates that there is the possibility of considering avalanches as a percolation event. However, there is no clear distinction from the percolation model that these events describe, either a homogeneous or non-homogeneous process. This work deals with avalanche simulations as physical cases of percolation. To characterize the avalanches, two percolation models were simulated: homogeneous and heterogeneous. Simulations were developed to compare avalanches in both models. To perform these simulations, the probability of a site being open equal to 0:5 was used. The sizes and transients were measured for each avalanche in the different models. To close the work, experiments were carried out to create avalanches, in order to better calibrate the simulations using real avalanche data. For when comparing the simulated results with existing data in the literature, a typical behavior of a probability function was perceived. Given this behavior one can make predictions about the size of the avalanches. Analyzing the results obtained, it is possible that the behavior of avalanches created with non-homogeneous probability presented well defined characteristics, having larger values of size and transient. It was concluded that the non-homogeneous model has a high stability and is better in the evolution aspect of the avalanche, so with some adjustments the heterogeneous model can approach a real avalanche with greater accuracy.
Acesso aberto (Open Access)
Ferramenta computacional para dimensionamento e avaliação de desempenho de sistemas fotovoltaicos conectados à rede elétrica
(Universidade Federal do Pará, 2012-10-11) PINTO FILHO, Gilberto Figueiredo; MACÊDO, Wilson Negrão; http://lattes.cnpq.br/3386249951714088
This dissertation presents the utilization of some mathematical models present on literature which represent the energy processing steps on Grid-Connected Photovoltaic Systems (GCPV). Besides, two models regarding the power limitation due to inverter’s temperature and the electric losses are proposed. All models are implemented at MATLAB GUIDE enviroment which allows the analysis, helps on the design and makes possible the operacionality simulation and and energy contribution of GCPV with diferent sizes. The work presents the program interface developed and its data validation by comparing it with experimental data. Some energy forecasting for five Brazilian cities are shown at the end of the work with examples on how analyze the data generated by the program.
Acesso aberto (Open Access)
Hermes: um software-modem ADSL baseado no framework Ptolemy II
(Universidade Federal do Pará, 2011-04-20) GUEDES, Gustavo Cunha; KLAUTAU JÚNIOR, Aldebaro Barreto da Rocha; http://lattes.cnpq.br/1596629769697284
This dissertation has as main objective to present the implementation of an ADSL software-modem totally written in Java, using the Ptolemy II framework, named Hermes (from \A Handy Experimental softwaRe ModEm System"). A software-modem is useful in cases where one needs to perform tests and simulations of communication systems with a large number of modems and when systems' parameters must be changed with high degree of freedom. Besides, a software-modem has features that make it easy to add, eliminate, validate and evaluate signal processing and telecommunications functions and algorithms. Tests and simulations were performed to evaluate the Hermes functionality, including the use of Tracespan, a non-intrusive analisys equipment for DSL networks. From obtained results together with Tracespan, it was possible to successfully validate the Hermes functions.
Acesso aberto (Open Access)
Impactos na qualidade da energia elétrica provenientes do rápido crescimento da demanda no Sudeste do Estado do Pará
(Universidade Federal do Pará, 2012-03-15) ESTEVES, Eduardo Augusto Cardoso; BEZERRA, Ubiratan Holanda; http://lattes.cnpq.br/6542769654042813; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
In the recent years, the social and economical development in the Southeast of the State of Pará has been mainly caused by the exploitation and processing of mineral industries, which added to the population growth, has generated a high increase in the demand of electric energy and consumption due to the increasing installation of new industrial, commercial, residential and rural single-phase charges. This global increase is impacting directly the performance of distribution of electric utility, which can be expressed by the permanent disturbances caused by harmonics, such as buzzing in the power transformer and disruption of medium voltage conductors. These disturbances will be presented in a study of case involving the Substations (SE’s) Itacaiúna and Itupiranga. To prove how they can be harmful in these SE’s, campaigns of measurement were performed to obtain practical results and then, to perform studies involving simulations of short-circuit, load flow and spreading of harmonics in order to obtain an analytical diagnostic about the situations found and thus to issue recommendations to solve the problems identified. This study will provide a valuable support to the Concessionaire of Energy and it may be taken as a reference to the study of Power Quality in other substations, in addition to experimental basis for future charges from ANEEL, regarding the implementation of procedures in Electric Power Distribution National Electric System (PRODIST).
Acesso aberto (Open Access)
Métricas de QoE/QoS de vídeo em redes sem fio para auxilio ao planejamento de ambientes indoor utilizando uma abordagem bayesiana
(Universidade Federal do Pará, 2015-03-30) CARVALHO, André Augusto Pacheco de; CAVALCANTE, Gervásio Protásio dos Santos; http://lattes.cnpq.br/2265948982068382
The evolution of applications on wireless networks has grown in recent years, due to the increased number of smartphone users, tablets and others. The availability of demanding services such as video transmission, affects Quality Experience (QoE) and Quality of Service (QoS) provided to domestic users and trade, this had stimulated the study of new resource management techniques networks, aiming to provide quality services to a customer each increasingly demanding. This thesis presents a methodology Intelligence Artificial using a Bayesian network with a hybrid evaluation strategy analyzing the behavior metrics QoE and QoS in the LAN network design wireless. The diversity of the place of Measurements chosen compound materials such as brick, glass, wood and concrete. It was necessary first to map all the points to be measured before and after deliberately placing each barrier outdated the signal. Metrics as level Receiver Signal Strength Intensity signal (RSSI) Jitter, delay end to end network for the video transmission, PeakSignal-to-NoiseRatio (PSNR) and Structural Similarity (SSIM) were collected during the Measurements. And using the Bayesian Network inferences were made for each metric and could not find satisfactory results for the proposed solution assist the wireless network planning in indoor environments. Enabling demonstrate that up to 10 meters away from the transmitter, the signal has its best power, and delay metrics in order to have more than 65% probability that the lower delay range and following this optimum performance the Jitter has more than 65% probability in this lower range. And the QE metrics, PSRN and SSIM have a similar behavior and has more than 80% probability of getting your greater value, and consequently the video has its best reception. These results show that does not preclude the use of this proposal in other situations.
Acesso aberto (Open Access)
Modelagem do rompimento e delimitação da área de inundação da barragem da Universidade Federal Rural da Amazônia em Castanhal-PA
(Universidade Federal do Pará, 2023-06-29) FONTES, Erick Alexandre de Oliveira; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690; https://orcid.org/0000-0003-1710-8862
Dams have structures that can cause changes over the years, which can cause changes in change processes, impacts, changes, changes in change processes, changes in the internal change process, changes in the change process, changes in the internal change process, changes in the process of change, changes in the process of internal change, overturning and others, the cause of which may come from natural phenomena or also from mismanagement. Thus, the experimental work presented as objective the objective of analyzing the hypothetical land located in the aquaculture station of the Universidade Federal Rural da Amazônia, in the municipality of objective Castanhal - PA. No methodological approach was used to simulate the flooding of the floodplain of HEC-RAS 5.0.3 (Hydrologic Engineers Corps – River System). The model software is based on the solution of permanent or non-permanent or two-dimensional Saint-Ven solutions, in version 5.3, considering the permanent regimes. The research numbers were observed from the simulation of the effects of the dam of results that were carried out: Seven, an information survey was carried out about the dam and an information survey was carried out with the ANA. A hazard implementation process is carried out afterwards and a report that this dam is nearing completion. Therefore, it is concluded in that study that the maintenance carried out in a severe way of materials and immaterial makes the impacts downstream, in front of the exposed, necessary to maintain the interdiction of the dam so that the maintenance of materials and emergency is necessary.
Acesso aberto (Open Access)
Políticas de alocação de espectro em roteamento baseado em balanceamento de cargas e fragmentação para redes ópticas elásticas
(Universidade Federal do Pará, 2015-02-05) DONZA, André Cunha de Sousa; COSTA, João Crisóstomo Weyl Albuquerque; http://lattes.cnpq.br/9622051867672434; FRANCÊS, Carlos Renato Lisboa; http://lattes.cnpq.br/7458287841862567
The rigid nature of wavelength division multiplexing (WDM) routed networks leads to inefficient capacity utilization. Thus, flexible networks are a possible breakthrough for optical technology, as long as they provide higher spectrum efficiency use. In order to assess the possible applicability of flexible networks, this work proposes a performance evaluation strategy based on simulations and comparisons between obtained results. Several discrete-time simulations were carried out in two simulators developed in Matlab in order to analyze different spectrum allocation policies (First-Fit, Smallest-Fit, Exact-Fit and Random-Fit) in some algorithms for single path routing: The External Fragmentation Aware Assignment (FA), the Shortest Path with Maximum Spectrum Reuse (SPSR) and the Balanced Load Score Spectrum Assignment (BLSA). Two network topologies were used: a small 6-node subset of Cost239 and a 7-node random topology. With no physical layer effects as restrictions, comparisons were made between the different techniques studied, aiming to point out, based on the specific features of the proposed scenarios, the most appropriate method of spectral allocation in terms of blocking frequency between the four considered spectrum allocation policies.
Acesso aberto (Open Access)
Projeto e fabricação de extrusora monorrosca com matriz de extrusão filamentar
(Universidade Federal do Pará, 2024-10-25) RODRIGUES, Rodimilson Coelho; EL BANNA, Wassim Raja; http://lattes.cnpq.br/2005046563115507; HTTPS://ORCID.ORG/0000-0001-5085-4352; NASCIMENTO, Walber Alexandre do; http://lattes.cnpq.br/8022410578951099; https://orcid.org/0000-0002-2699-3982
Large industrial establishments are always looking for increasingly sophisticated technologies to monitor manufacturing processes. This work aims to design and build a laboratory single-screw extruder and its extrusion die for processing polymers and polymer composites, in addition to enabling studies in the area of mechanical recycling of polymers. The first stage of the work involved choosing the type of extruder to be manufactured. The second stage consisted of dimensioning and designing the equipment using Solidworks software. In the third stage, the types of materials and mechanical and electrical components for assembling the extruder were selected. In the fourth stage, the manufacturing processes of the extruder and assembly of the mechanical and electrical components were carried out. In the fifth stage, the equipment was validated, where temperature and mass flow tests were performed, in addition to mechanical and electrical tests in the processing of a thermoplastic polymer, which, in this case, was polypropylene (PP). The last stage consisted of simulating a die with a cylindrical profile, aiming to study the characteristics of the polymer melt flow and define how the die structure should be adjusted to obtain the desired diameter. After designing the die in Solidworks software, a simulation was performed in Ansys software. In this case, the rheological behavior of the melt as it passed through the die was studied through the simulation, analyzing in which part of it the high and/or low shear rates are observed when the polymer flows through it. The drag flow and pressure flow were then extracted from the simulation parameters, which led to the calculation of the operating point and operating pressure for the die. It was also possible to calculate the mass flow rate and the velocity drop at the die wall, in addition to optimizing the die profile for the circular shape and desired diameter.
Acesso aberto (Open Access)
Projeto e implementação em DSP de sistema de comunicação multiportadora baseado no padrão G.fast
(Universidade Federal do Pará, 2013-08-30) ALMEIDA, Igor Mesquita de; KLAUTAU JÚNIOR, Aldebaro Barreto da Rocha; http://lattes.cnpq.br/1596629769697284
The evolving broadband access systems using copper networks are currently deployed in a frequency band that goes up to 30 MHz, as specified in VDSL2. As hybrid fiber-copper architectures become more important in the industry and academia, using shorter loop lengths (i.e. up to 250 meters) from the last distribution point to users enables adopting even higher frequencies to achieve very high data rates of 500 Mbps and beyond, as is the case with the G.fast standard under development by ITU-T. In this work, a time-domain simulator has been developed to evaluate G.fast system performance with different cyclic extension lengths and different reference loop topologies specified by ITU-T. The simulation results show that G.fast systems are robust to bridged taps and capable of providing very high data rates for all simulated loop topologies to support next generation ultra high speed broadband services. Furthermore, this work describes an ongoing effort to implement a G.fast-based modem protototype in a hybrid multicore DSP and FPGA environment using readily-available evaluation kits purchased by UFPA. Architecture plans, communication protocols and benchmarks are presented and evaluated to conclude that such a prototype is both feasible and flexible to support several avenues of research in next generation broadband.
Acesso aberto (Open Access)
As redes WLAN serão superadas? Um estudo de viabilidade de redes WLAN em densenets: uma análise baseada em QOS/QOE
(Universidade Federal do Pará, 2015-09-04) CASTILHO, Jessica Janile Monteiro de; ARAUJO, Jasmine Priscyla Leite de; http://lattes.cnpq.br/4001747699670004; FRANCÊS, Carlos Renato Lisboa; http://lattes.cnpq.br/7458287841862567
The proliferation of mobile devices like smartphones and tablets and the changes of user profile caused the exponentially growth of mobile data traffic. Which leads to an overload of network infrastructure responsible for disposing of this traffic. In order to mitigate or even solve this problem some possibility are presented, one of which is the offloading of traffic cellular networks. For this, two technologies have had greater relevance: Femtocell and WLAN. However, the use of Femtocell has been considered panacea. However there is the alternative of WLAN networks, which has a very large legacy infrastructure. In this sense, this work proposes a comparative study through discrete simulation, aiming to analyze the performance of our networks.
Acesso aberto (Open Access)
Simulação do processo de extração supercrítica do óleo de tucumã-do-Pará (Astrocaryum vulgare) usando aspenHYSYS
(Universidade Federal do Pará, 2023-09-25) MORAIS, Rayelle Mendonça; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
The adaptation of industrialization in the form of a sustainable economy, technological advances and computational benefits have motivated the use of process simulators to evaluate the potential of oleaginous species native to the Amazon region through fast and automated simulations. Therefore, the objective of this work was to apply the AspenHYSYS simulator to describe the tucumã-do-Pará oil extraction process using supercritical carbon dioxide as solvent. The feasibility of simulations of the tucumã oil extraction process using the mathematical models of Menezes et al. (2023) and Tan and Liou (1989) were comparatively evaluated with experimental data previously selected from the literature. Simulations of the supercritical extraction of tucumã-do Pará oil found that the model by Menezes et al. (2023) was adequate to describe the experimental kinetic data for all evaluated systems, which presented an RSD with a lower value of 0.57. The energy and material cost were calculated, and the value obtained (2.82 R$/g of oil) together with the high concentration of bioactives in the product demonstrate that the studied process presents a positive cost-benefit ratio. An increase in scale was carried out for beds 1, 5, 10 and 50L. For beds of up to 10L, an adequate projection of the process was obtained, considering that the deviations obtained were less than 1, however, for 50L, the adjustment presented a deviation of 58, which may infer that the model used has a scalability limit. Simulations of the supercritical extraction of tucumã-do-Pará oil, using AspenHYSYS, led to values consistent with the experimental data, thus confirming that the studied plant proved to be an effective tool for the study of the process.
Acesso aberto (Open Access)
Simulador em realidade virtual para o manejo de lesão por pressão para discentes do curso de graduação em enfermagem
(Universidade Federal do Pará, 2025-06-03) TEIXEIRA, Niceane dos Santos Figueiredo; MONTEIRO, Dionne Cavalcante; http://lattes.cnpq.br/4423219093583221
This dissertation investigated the elaboration, development, testing, and outcomes of a simulator within a virtual reality environment as an innovative pedagogical approach for the teaching-learning process of pressure injury management in an undergraduate nursing program. To substantiate this research, the contributions of active methodologies are highlighted. These have emerged as pedagogical strategies focused on promoting active student learning. In this context, virtual reality (VR) is employed as an innovative technological resource for teaching and improvement in the healthcare field, with a particular focus on nursing. The methodology was applied research, employing a quantitative-qualitative, exploratory, and descriptive approach. For theoretical grounding and contextualization, an integrative literature review and data collection were conducted. The simulator software was developed by a multidisciplinary team, utilizing the 3D modeling system Blender 3.5 for the creation of virtual elements. The integration of these models into the immersive virtual reality environment was executed through the Unity 3D game development engine. Product testing involved the utilization of virtual reality resources, such as the Oculus Rift, consoles, and motion sensors, in conjunction with a monitor and computer, thereby providing students with an interactive and immersive experience within the simulated pressure injury management scenario. The research involved the participation of nursing specialists and undergraduate students and was conducted at the Laboratory of Applied Artificial Intelligence (LAAI) of the Federal University of Pará (UFPA), located in Belém. Data collection at each stage of the development and testing process employed specific instruments. The analysis of the obtained data encompassed content analysis of discursive and objective responses, and the interpretation of quantitative data presented in graphs, aiming to understand the participants' perception of the simulator. The results and discussions presented in this dissertation demonstrate that the developed virtual simulator possesses significant potential as an empowering and facilitating tool for the teaching-learning process of pressure injury management in nursing education.
Acesso aberto (Open Access)
Sistematização de projetos de controladores fuzzy através de programação orientada a objetos
(Universidade Federal do Pará, 2009-10-06) LEITÃO, Álvaro Luís dos Reis; COSTA JÚNIOR, Carlos Tavares da; http://lattes.cnpq.br/6328549183075122
By using object oriented language programming and, applying a specific programming technique, it‟s possible to generate a set of generic classes whose objects represent each block of a fuzzy controller as well its linguistic variables. Such classes, being applied in a systematic way, make easy the programming of a set of controllers of this nature. This work presents this technique and shows the results obtained via a model simulation of a inverted rotational pendulum which is controlled by a control system composed by three fuzzy controllers designed and built under this point of view.
Acesso aberto (Open Access)
Soluções híbridas com uso de transformadas integrais na análise do escoamento em mancais de escora circulares
(Universidade Federal do Pará, 2014-12-15) MEDEIROS, Nielson Veloso; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785; https://orcid.org/0000-0001-9365-7498
This paper explores the modeling and solution of the Reynolds equation and simulate the problem of hydrodynamic lubrication in bearings of circular anchor shoes with Rayleigh and milled pad. Mathematical modeling of the problem of hydrodynamic flow in bearings with consideration of centrifugal inertial terms produces a modified generic equation Reynolds called Reynolds equation with inertial terms version. This equation is solved by the generalized integral transform technique (TTIG) method, where it transforms the Reynolds equation system for generating a common, endless and non- linear equations for obtaining the analytical and numerical solutions of the field of fluid film pressure, the charge and power consumed by the bearing, where these performance parameters depend on the geometry adopted for the bearing. Thus, four algorithms were originated by the transformed system, and the difference between them are the geometries chosen for the bearings, but all computer codes made use of the traditional way of TTIG. In all codes were implemented in Fortran 90/95 language and solved by routine BVPFD of IMSL (1987) library. The solution to said Reynolds equation expressed using the work dimensionless transfer potential P(r,) that was found for various combinations of dimensionless coefficients that constitute the terms of this equation. The applicability of the technique was verified by comparing the results from the use of GITT the values found by the finite volume method (FVM) in a paper published by Blanco e Prata, 1998 e 2014. Behavior of pressure fields was verified by varying the sizes of the series obtained by computer codes. The results show reasonable convergence.