Navegando por Assunto "Modelagem"

Agora exibindo 1 - 20 de 26

Acesso aberto (Open Access)
Análise da aplicação de modelagem e simulação computacioal como apoio à tomada de decisão em processos produtivos industriais: estudo de caso em uma organização do segmento de duas rodas
(Universidade Federal do Pará, 2011-02-28) NOGUEIRA, Reginaldo Alves; OLIVEIRA, Roberto Célio Limão de; http://lattes.cnpq.br/4497607460894318
This study aims to analyze the resources and advantages of using modeling and computer simulation in industrial manufacturing processes as a tool to support the decision making. Thus, a case study was made at a motorcycle company located in Manaus’ Industrial Center, in which they used the software Tecnomatix® Plant Simulation. Initially, it was developed a simulation project, based on the industrial manufacture of a productive process of the variable support, an important item on the motorcycles production. This manufacture is known for its high complexity, due to the risks during its productive process. This dissertation also presents concepts related to the production management and the importance of decision making as well as the main definitions of modeling and computer simulation, with emphasis on Plant Simulation platform. Some other advantageous applications of using the modeling and computer simulation as tools have been identified, as we wrote this dissertation. However, we would rather make a restriction and just demonstrate the optimization of a manual productive process. After analyzing the simulation’s results, in multiple virtually modeled scenarios, taking into consideration the risk and productivity parameters, as well as having a systemic understanding of the situation, we considered the best option to organize would be the automated productive scenarios whose layouts allow greater interaction, flexibility, productivity and lower risk - providing the maximization of the desired results. Finally, from the analysis of the achieved results, as well as the relevant conclusions, it is easier to see clearly the advantages and resources of applying computer simulation as a support tool on the decision making in industrial manufacture processes.
Acesso aberto (Open Access)
Anomalias eletromagnéticas de corpos tubulares inclinados em contato com o manto de intemperismo usando diferentes arranjos de bobinas-modelamento analógico
(Universidade Federal do Pará, 1997-03-16) SILVA, Roberto Cesar Alves; VERMA, Om Prakash; http://lattes.cnpq.br/2723609019309173
Electromagnetic methods are mainly applied in the prospection of massive sulphide deposits. These deposits are frequently long in extension and thin, therefore the interpretation can be carried out considering a half-plane model in a resistive ambient. However, in Amazon region or in semi-arid and tropical regions where a partialy conductive to conductive overburden is encountered, interpretations using a resistive ambient model give erroneous results. The objective of this work is to study the influence of the conducting overburden on electromagnetic anomalies of inclined sheet-like bodies in ohmic contact with the overburden, using coil configurations - horizontal coplanar (HCP), vertical coplanar (VCP), vertical coaxial (VCA) and minium couple system (PERP). These studies are realized with the aid of analog modelling where the ore-body is simulated by a graphite sheet and the conducting overburden by ammonium choride solution. Generally, the diferente coil systems studied here show the similar characteristics of the overburden effects, reserving some peculiar effects of each coil system. The effects of a conductive overburden in ohmic contact with the orebody could be briefly described as follows: (i) There is an anti-clockwise phase rotation initially with the increase in the overburden induction number, but with further increase the phase rotates clockwise; (ii) The form of the quadrature anomaly profile is altered due to the appearence of an extra peak on the down-dip side of the ore-body, and (iii) The peak to peak quadrature anomaly on the up-dip side increases uniformly with increase in the overburden induction number. Highest anomalies are obtained with the horizontal coplanar system and lowest with vertical coplanar. No extra-peak in the quadrature profile is observed with the vertical coaxial system in this study. Also, the overbuden effects are more prominent in the horizontal coplanar system compared to vertical coil systems, and in the anomalies of the less inclined half-planes and at lesser depths.
Acesso aberto (Open Access)
Avaliação do modelo hidrodinâmico SMC: uma aplicação na Costa Norte Brasileira
(Universidade Federal do Pará, 2016-05-24) MOTA, Fabíola Cardoso da; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471
Coastal environments are highly dynamic because of complex processes that occur in the transition between the ocean and the continent. Climate changes induce changes in the coastal zone that cause decline in economic, environmental and subsistence values. The integrated coastal zone management is a continuous and dynamic process, in which decisions should be taken in order to sustainable development and protection of resources of coastal and marine areas. The main goal of integrated coastal zone management is to improve the life quality of human communities that are dependent of coastal resources, taking into account the maintenance of biological diversity and ecosystems productivity. The coastal modelling system called SMC Brazil was introduced in Brazil by the Ministry of Environment in order to standardize the modeling throughout the coastal zone of the country. This study aims to implement the model SMCBrasil in North Coast of Brazil (Princesa beach- Algodoal Island), evaluate it and analyze the hydrodynamic answers, in order to know more about coastal processes that govern this region. In order to understand the processes in the study area, the methodology consisted in collect in situ data to know about the intensity of coastal parameters. 6 cases were created in the model to represent the wave theories (Linear, Stokes and Composite) and sediment transport (Bailard and Soulsby) for two moments of tide: low tide and high tide. Two mesh grids were created in the study area, and one entry point that would fit better to it and the conditions limits of the model was chosen. The propagated waves by the composed theory represented the study area in question more than the others, and the simulated sediment transport simulated by Soulsby theory suffered less interference of interpolation than the Bailard, since it considers the bed transport and suspension. The simulated cases in this study were based on boundary conditions that more often occur on the study area, so the results can be used as a basin to understanding how the coastal processes occur in it in general way.
Acesso aberto (Open Access)
Cenários de uso da terra nas mesobacias hidrográficas dos igarapés Timboteua e Buiuna, Pará
(Universidade Federal do Pará, 2011-08-19) NASCIMENTO, Nathália Cristina Costa do; BÖRNER, Jan-Christoph; FENZL, Norbert; http://lattes.cnpq.br/6834981018643186
The northeastern Pará is among the first regions of the Amazon receiving projects for induction occupation. Their forms of land use intensely focused on agricultural production triggered in the course of time a distortion of the natural landscape, natural resources and commitment to change in natural processes. Currently, the region is considered the most degraded landscape of the Amazon may be an example for areas frontier agricultural. Thus, this work focused on two river basins located between the towns of Igarapé-Açu and Marapanim in the northeastern region of the State of Pará, with the aim of understanding the dynamics of existing land uses, as well as its future trends, emphasizing their likely consequences on natural resources. The study adopted remote sensing techniques to obtain information about the dynamics of land use based on Landsat-TM image for the years 1984, 1994, 1999, 2004 and 2008. From the resulting use of dynamics, modeling tools were applied to generate future scenarios of land use, were also analyzed in terms of opportunity cost in some agricultural crops in order to discuss probable alternatives to existing forms of use. The results present the scenarios generated for the year 2020 for the two river basins studied; focuses on the impacts that may arise from the different scenarios generated and also highlight the need for projects that take into account local economic and social activities so that production and conservation can be complementary and not opposing, which can be built with technical and scientific support and political will.
Acesso aberto (Open Access)
Clima, solo e água: importância de variáveis ambientais na determinação da distribuição potencial de peixes de rios e riachos amazônicos
(Universidade Federal do Pará, 2017-10-19) ALVAREZ, Facundo; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099; GERHARD, Pedro; http://lattes.cnpq.br/5621269098705408
Estimating the spatial distributions of species is one of the main objectives of macroecology, especially when sampling efforts fail to reach the demographic knowledge of the target species. In this sense, the species distribution models (SDM) allow us to approach the fundamental niche of the species from the extrapolation of predictor variables. The Amazonas-Tocantins basin is characterized by a strong environmental and physical dynamics that act differently in the regional ichthyofauna at different spatial scales. Due to the differential perception of hábitats by the species, four species of rivers were included, Ageneiosus inermis, Acestrorhynchus falcatus, Pygocentrus nattereri and Plagioscion squamosissimus, and four species of streams, Crenuchus spilurus, Helogenes marmoratus, Helogenes marmoratus and Trichomycterus hasemani. The objectives of the study were: (i) To determine which set of predictor variables allows better spatial representations for the species of rivers and streams using SDM; and (ii) To evaluate the predictive power of MaxEnt to generate SDM of rivers and streams using different sets of Predictor variables. The spatial records that presented spatial autocorrelation were processed from the spThin package. To characterize the environmental dynamics, 78 predictors were divided into three treatments: PCA1 (climatic variables), PCA2 (climatic variables, slope and accumulated flow) and PCA3 (climatic variables, slope, accumulated flow, topographic and edaphic variables). MaxEnt software was used and configured from the ENMeval package. Two aspects can be observed in the results: the use of hydrological, topographic and edaphic variables allows to obtain more precise and spatially restricted representations than only climatic variables. In the second place, it is evident that, regardless of the dimensional complexity of the system, MaxEnt allows to obtain MDEs with high predictive power for both river species and species of streams. In the case of river species, the macroscopic predictors (climatic variables - PCA1) allowed to represent their environmental requirements and their wide spatial distributions. Meanwhile, climatic, hydrological, topographic and edaphic variables (PCA3) acted as environmental filters restricting the spatial distributions of both species of rivers and streams. The dimensional complexity of the system does not affect the spatial representation capacity of Maxent, observing that, in the case of species of streams MaxEnt showed greater capacity of spatial representation.
Acesso aberto (Open Access)
Desenvolvimento de um sistema de alerta de enchente aplicado aos planos de defesa civil em áreas de risco no estado do Pará utilizando Sistema de Informações Geográficas (SIG), caso: cidade de Marabá
(Universidade Federal do Pará, 2012-03-02) COSTA, Jamer Andrade da; COSTA, Tony Carlos Dias da; http://lattes.cnpq.br/5776447682706171
This dissertation develops a Flood Warning System for the city of Marabá, located at the confluence of Tocantins and Itacaiúnas Rivers, 400 quilometers south from Belém, capital of the State of Pará (Brazil). The Flood Warning System is based on the hydrological model MOD-4B incorporated into a Geographic Information System. This system forecasts changes in the level of the Tocantins River throughout the year. It monitors the initiation of the flood 4 days in advance, resulting in more efficient Civil Defense actions. As reference, the forecasting model used the limnimeter poles located on the Tocantins and Araguaia Rivers, in the towns of Carolina and Conceição do Araguaia, respectively about 225 and 270 quilometers south from the city of Marabá. The system uses the GIS software ArcView 3.3, which was implemented through an interface developed through an object-oriented programming language called Avenue to run the application of the hydrological model. The use of windows and menus adapted to the model grants access to spatial data and relational database tables and / or record database. It also provides modules for spatial analysis and visualization of geographic data in a Geographic Information System (GIS), which forecasts flooding in the form of maps, charts and reports, showing the flooded areas for periods of 4, 3, 2 and 1 day before the occurrence of flooding. The system also identifies the affected streets and buildings, quantifying the affected population and the damages caused. With this, the Civil Defense can execute efficient action plans before, during and after the flooding.
Acesso aberto (Open Access)
Efeitos do manto de intemperismo sobre anomalias “VLF” dos corpos tabulares inclinados
(Universidade Federal do Pará, 1997-03-16) ROZAL, Edilberto Oliveira; VERMA, Om Prakash; http://lattes.cnpq.br/2723609019309173
Application of eletromagnetic methods for mineral exploration in tropical regions is complicated due to a presence of a conducting overburden encountered in these regions. In the Amazon region, overburden is well developed and conductive; while in semi-arid regions there may be a fine layer containing salts. Consequently, considerable error is introduced in the interpretation of EM data if the presence of the conducting overburden is ignored. In order to study the overburden effects, on VLF anomalies due inclined tabular bodies in contact with the former (Ohmic - overburden), a number of analog model experiments were conducted for varying response parameters of the overburden and the ore body. Overburden is simulated by an amonium chloride solution (NH4Cl) and the ore body by inclined grafite sheets of different thicknesses. Three overburdens of varying conductance were used to simulate diverse geological situations. Both, tilt-angle and elipsity anomalies decrease in amplitude with the increase in depth of the ore body and the position of the peak in the profile is removed further away from the crossover irrespective of the presence of the overburden or not. There is some increase and tilt-angle anomaly profiles. Eliptisity anomaly increases with the increase in the condutance of the overburden while tilt-angle anomaly decreases a little bit. However, at higher overburden condutances both of then are attenuated. Phase angle are rotated anti-clockwise with the overburden. This rotation is more intense at higher induction number of the conductor. In the presence of the ohmic-overburden and at moderate values of their condutance, the conductor appears (i) at lower depth than the real, due to the increase in the anomaly amplitude, and ii) less conducting due to the anti-clockwise rotation of the Argand diagram.
Acesso aberto (Open Access)
Efeitos do manto de intemperismo sobre anomalias eletromagnéticas provocadas por corpos tabulares inclinados: um estudo através de modelamento reduzido
(Universidade Federal do Pará, 1981-09-18) SILVA, Lúcia Maria da Costa e; VERMA, Om Prakash; http://lattes.cnpq.br/2723609019309173
Electromagnetic methods have been extensively applied in the prospecting of sulphide bodies and other conducting materials. The interpretation of e. m. data is based on the results obtained either with reduced scale or analytical modelling. In most models, the host rocks, the overburden as well as the halo of disseminated sulphides are considered highly resistive although in nature they are often weakly conductive. Presence of a well-developed conducting overburden in tropical and sub-tropical regions and a saline rich crustal layer in semi-arid regions have been found to modify significantly the e. m. anomalies in practice. Therefore, the parameters of the target, determined on the basis of simple models where the presence of the conducting environment is neglected, are found to be in considerable error. The effects of the overburden on the e. m. anomalies of a dipping tabular ore body were studied with reduced scale models for varying response parameters of both the overburden and the orebody, and also for different depths and dips of the target. The overburden and the orebody were represented by metallic sheets of varying thickness in the scale model developed in accordance with the law of electromagnetic similitude. The results of these investigations show that the overburden affects the anomaly by causing: a) phase rotation; b) amplitude reduction; c) base level displacement; d) reversion of the quadrature; and e) appearance of an extra peak in the quadrature in the case of low dipping models. The last two effects complicate the quantification of the anomalies but, on the other hand, provide a qualitative indication of the response parameters of both the ore body and the overburden. The results were assembled in the form of Argand diagrams and, finally, an interpretation scheme is suggested for the e. m. field data on the basis of these diagrams.
Acesso aberto (Open Access)
Effect of wind in the design of reinforced concrete buildings
(Universidade Federal do Pará, 2016-12) TAPAJOS, Luamim Sales; FERREIRA, José Augusto Tavares; LIMA NETO, Aarão Ferreira; TEIXEIRA, Marcelo Rassy; FERREIRA, Maurício de Pina
This paper presents the results from a parametric study carried in order to quantify how far errors in the design stage related to the consideration of the wind action may put at risk the response and safety of reinforced concrete buildings. Using an architectural model as reference and varying the number of floors of the building, the structural safety was evaluated as a function of the wind action intensity. Results showed that even for low-rise buildings, with 10 floors, ignoring the wind action can significantly jeopardize their behaviour and safety. Yet, for slenderer buildings, up to 30 floors, it can lead to catastrophic results, as the ruin of the structure by progressive collapse.
Acesso aberto (Open Access)
Estudo da resposta de perfilagem de indução de camadas finas com diferentes arranjos de bobinas: modelamento analógico
(Universidade Federal do Pará, 1993-12-16) CARVALHO, Paulo Roberto de; VERMA, Om Prakash; http://lattes.cnpq.br/2723609019309173
Analog model studies were carried out comparing the eletromagnetic responses of various two-coil systems in a borehole, in order to improve the vertical resolution of the indution tools. For this purpose geoeletric models, simulating well-logging situations in the stratified beds of varying thicknesses, with or without fluid invasion, were constructed at a reduced scale of 20. The sensitivity of the system to measure relative fields (secondary/primary) is of the order of 0.01 %. Following conclusions were drawn after analysing the response profiles obtained for a coaxial and a coplanar coil systems: • In case of thin conducting beds placed in relatively resistive beds, such as shale beds in sandstones containing hydrocarbons, the coaxial system shows a better resolution than coplanar system both in determination and estimating the thickness of thin beds; • On the other hand, in the presence of thin resistive beds placed in relatively conductive zone, such as sandstone containing hydrocarbons lying in a shale, the coplanar coil system gives a better vertical resolution than the coaxial system; • "Shoulder effect" is much more pronounced in the coaxial system than the coplanar coils; • In case of thick beds, bed-boundaries are well defined in the coplanar coil system response. However, when the thickness is reduced the small oscillating signal indicating the interfaces disappears.
Acesso aberto (Open Access)
Estudo de anomalias eletromagnéticas de um condutor tabular vertical sob camadas parcialmente condutiva em multifrequência e multiseparação através de modelamento analógico
(Universidade Federal do Pará, 1986-05-09) QUEIROZ, Joaquim Carlos Barbosa; VERMA, Om Prakash; http://lattes.cnpq.br/2723609019309173
Partially conducting environment surrouding an one body highly affect its electromagnetic response. Conducting host rock, overburden and disseminated sulphide halo, for example, affect the electromagnetic response in different ways depending upon their electrical properties, areal and geometrical relation with the target, and in particular to the EM system used for prospecting. In the thesis, EM anomalies due to vertical tabular conducting bodies under am overburden, obtained through reduced scale models, are analised for different ground EM systems - horizontal coplanar, vertical coplanar and vertical coaxial - in 8 frequencies between 250 Hz to 35 kHz and the coil separation 0,15; 0,20 and 0,25m. Overburden was simulated by horizontally placed thin stainless steel sheet and the main conducting target by thin aluminium shets placed vertically below the former. The dimensions of these sheets were determined according to the modelling conditions for a plane and half-plane. Various geological situations were represented in modelling using the combinations of the three metallic sheets of varying thicknesses and conductivities to simulate the ore body and another three sheets to simulated the overburden. Set of diagrams are plotted using peak-to-peak in phase and quadrature anomalies for analyzing the results. However, another set of diagrams show that the maximum in phase anomaly occurs when the quadrature countpart is zero at relatively low frequencies when the ore-body together with the overburden is studied. On the other hand, the maximum amplitude in quadrature is obtained at relatively high frequencies when the in phase component attains the minimum, almost zero. With this type of analysis, it was to known the band of frequencies, for each of prospecting systems studied, in wich the EM response of the ore body is least affected by the overburden. Highest response was obtained with the horizontal coplanar system and the least with the vertical coplanar coils. An increase in the separation between the transmitter-receiver resulted in dislocating the peaks to lower frequencies. Widest band of frequencies, in wich the EM response of the body is least affected by the overburden, is obtained in case of vertical coaxial system and narrowest for the horizontal coplanar coils. These results helps us in planning the EM prospecting systems by knowing the position and the band with of frequencies to be used along with otimum transmitter-receiver separation such that the EM response remains free from undesired signals, for example those caused by to overburden.
Acesso aberto (Open Access)
Evapotranspiration from Remote Sensing to Improve the Swat Model in Eastern Amazonia
(Universidade Federal do Pará, 2015-12) SOUSA, Adriano Marlisom Leão de; VITORINO, Maria Isabel; CASTRO, Nilza Maria dos Reis; BOTELHO, Marcel do Nascimento; SOUZA, Paulo Jorge de Oliveira Ponte de
In this study, we estimated the evapotranspiration from orbital images - MODIS (Moderate Resolution Imaging Spectroradiometer) for assimilation in the hydrological modeling of the SWAT (Soil Water Assessment Tools) model. The data used include the period between October 2003 and December 2006 of the sub-basin of the Lajeado River, located in the Tocantins-Araguaia River basin in Tocantins state. Overall, the results of the use of heat flows estimated by remote sensors in the SWAT model can be considered satisfactory. The values of the COE (coefficient of efficiency of Nash-Sutcliffe) ranged from -0.40 to 0.91 in the comparison with the daily flow data and from 0.17 to 0.77 with the monthly flow data, with the assimilation of evapotranspiration from orbital images. These results indicate benefit to the model adjustment due to improvement in the data assimilated of approximately 0.91 in the COE on daily scale and 0.60 in the CEO on monthly scale.
Acesso aberto (Open Access)
Interface gráfica para pré e pós-processamentos de dados elétricos e eletromagnéticos em Geofísica
(Universidade Federal do Pará, 2001-10-09) MONTEIRO, Humberto Deodato Malcher; RIJO, Luiz; http://lattes.cnpq.br/3148365912720676
Acesso aberto (Open Access)
Interfaces gráficas de entrada e saída da eGs (electrical GEOPHYSICS suite)
(Universidade Federal do Pará, 2005-03-14) SILVA, Rodrigo Erasmo da Conceição; RIJO, Luiz; http://lattes.cnpq.br/3148365912720676
We present a graphic interface for the program eGs (electrical GEOPHYSICS suite) used for modeling and interpretation of electric and electromagnetic data in geophysical exploration. This master degree dissertation corresponds the portion of the program that treats the interfaces for bi and three-dimensional input data of geoelectrical models together with interfaces for the presentation of the modeling results and for the presentation of observed data as well. The program contains interfaces for creation, modification and visualization of bi and threedimensional geoelectrical models and for illustrations of the calculated results through graphs and images. This work gives a program with several options to alter the geometry and the physical properties of the geoelectrical models, including facilities for three dimensions visualization in order to help geophysical data interpretation. The graphic interfaces can be used to create geoelectrical models associated with the most used electric and electromagnetic geophysical methods and to analyze the answers obtained by numerical modeling associated with different types of observed data in field campaign. The program is sufficiently flexible so that new graphic interfaces of other electric and electromagnetic methods can be implemented easily.
Acesso aberto (Open Access)
Modelagem da disponibilidade de uma unidade geradora da UHE-Tucuruí
(Universidade Federal do Pará, 2013-07-04) MOREIRA, Pedro Igor Carvalho; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
Since 2004, the regulatory rules in the Brazilian Electricity Sector has changed. The agents who act in this market have experienced a rise in new business disputes, showing an increase in competitiveness. The availability of physical assets and maintenance costs are presented as key points of these agents competitiveness. This work aims to present a methodology of Availability Analysis of Repairable Systems during the design or operational phases, covering the measurement of maintenance costs versus the acquisition costs to an expected performance level. The suggested methodology takes the System Block Diagram and exports to the Successful Tree Analysis format, composed by logic gates "AND" and "OR" where each represents a subsystem in the main system. The analyst may re-evaluate the system's topology, adding or removing redundancies in order to adjust the performance to the requirements of availability, acquisition and maintenance costs. As results of this work were identified gaps in the standards rules which defines how to control the assets performance, was established a systematic integration of modeling techniques for reliability and availability, performance indicators of Scheduled Maintenance were incorporated, different scenarios were modeled for an Oil Circulation System and was applied to an entire Hydraulic Generating Unit by modeling the critical components in the main systems.
Acesso aberto (Open Access)
Modelagem da palma de óleo na Amazônia: redução da adequabilidade climática até o final do século
(Universidade Federal do Pará, 2023-09-29) MENEZES, José Felipe Gazel; ARAÚJO, Alessandro Carioca de; http://lattes.cnpq.br/6188087583954899; https://orcid.org/0000-0002-7361-5087
The Amazon has historically suffered from deforestation. From the end of the 1960s to the present day, the occupation process has always been carried out in a disorderly manner. In addition to this fact, there are local problems characteristic of the Amazon region, such as land grabbing and invasion. Therefore, such factors help to explain why the Amazon region has extensive deforested and abandoned areas. This work highlights oil palm monoculture as an alternative to reintegrate and transform abandoned areas into productive areas. Additionally, the importance of oil palm production for the global and local market is presented, and how climate change may affect oil palm production in future scenarios. A surface model developed by the Brazilian Agricultural Research Corporation (EMBRAPA) is used to estimate oil palm production. This study was conducted in an oil palm monoculture with interspecific hybrid (HIE), generated from the cross between the species Elaeis guineensis Jacq (African) and Elaeis oleifera (Kunth) Cortés (American). Subsequently, by building a species distribution model, we estimate how areas climatically suitable for oil palm cultivation may change in the future, based on IPCC climate change scenarios.
Acesso aberto (Open Access)
Modelagem da perda de qualidade de videos H.264 em redes sem fio considerando perdas de PSNR e de frames
(Universidade Federal do Pará, 2019-08-16) CARMONA, João Victor Costa; CAVALCANTE, Gervásio Protásio dos Santos; http://lattes.cnpq.br/2265948982068382; BARROS, Fabrício José Brito; http://lattes.cnpq.br/9758585938727609
Multimedia applications have been growing in recent years; new consumptions like online games, video conference, video on demand and IP telephony are some of these. However, there is a greater prominence in the search related to videos and streaming, currently in high resolutions and mostly traffic over wireless networks, mainly due to the proliferation of mobile devices and significant increase of access networks, which make it more comfortable. Providing this information is easy. Thus, as an immediate consequence of this type of flow, there is a need for investments in techniques and mechanisms that provide the end user with the desired quality and satisfaction in the face of high definition content. This work aims to perform the modeling of video quality loss by analyzing their performance in various resolutions, specifically standards in HD and UHD, at 720p, 1080p and 2160p. In this sense, applying a correlation investigation between the metrics extracted from the videos, using Pearson’s correlation coefficient, and fundamentals of the area in question. Also proposing equations for quality loss modeling, based on analysis of metrics associated with packet loss, in which at the end of the study and according to notes made throughout the text, we used for the general modeling equation, the parameters of Loss of PSNR and Loss of Total Frames. The result obtained shows maximum values of RMSE and Standard Deviation of 0.793 dB and 0.810 dB, respectively, making the developed model very good for the tested video set and its resolutions.
Acesso aberto (Open Access)
Modelagem do “tempo de execução” de obras civis: estudo de caso na Universidade Federal do Pará (UFPA)
(Universidade Federal do Pará, 2010-12-06) COUTINHO, Lêda Sílvia de Aguiar Lédo; DUARTE, André Augusto Azevedo Montenegro; http://lattes.cnpq.br/1135221873341973; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
The aim of this research is to propose a numerical model that treats the variable time so efficient and effective in order to meet the real needs of customers, users and society in general. However, was performed a survey bibliographic on public management, in respect of public works, statistics and operational research to the organizational system, aiming to numerical modeling. The research was based on quantitative methodologies, with emphasis on operational research for the study of public works performed under the management of PCU/UFPA. In developing the database, information was collected construction, renovations and expansions, implemented during the period 2006 to 2009, with the Permanent Commission for Bidding (CPL) and the Foundation that support the Research Development (FADESP). By linear regressions and after the transformed functions were obtained for the model prediction the statistical parameters: correlation coefficient (R) of 0.899, the coefficient of determination (R²) of 0.808, the coefficient of determination (adjusted R²) of 0.796 and error standard (Se) of 0.41. These parameters show a strong linearized correlation between the variables, indicating that 79.60% of the variability of time to execute a public work is caused or produced by variations together the area, the budgeted value, the operational capacity of IFES; operational capacity of the company; the type of service, and the season. With the results, it was concluded that it is possible to apply and implement the prognostic model for public works, considering that it is a powerful tool in its application to improvement of administrative procedures, both in structure and in its performance, whose main result is forecast variable “time of execution” for the performance of public enterprise.
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)
Modelagem e simulação da operação de sistemas de geração com fontes renováveis de energia suprindo minirrede de distribuição
(Universidade Federal do Pará, 2018-01-19) FERREIRA, Andreza Cardoso; GALHARDO, Marcos André Barros; http://lattes.cnpq.br/6672470707462259; PINHO, João Tavares; http://lattes.cnpq.br/0847897516772421
This work is about the development of computational models in Simulink/Matlab workspace, that simulate the operation in islanded or grid connected mode of electrical energy distribution microgrid with hybrid resources, belonging to the Group of Studies and Development of Energy Alternatives (Grupo de Estudos e Desenvolvimento de Alternativas Energéticas - GEDAE) of Universidade Federal do Pará (UFPA), in the Campus of Belém. This paper also describes the hybrid systems and its components (generation systems, power conditioners, microgrid and proposed loads), also the mathematical models, presenting the equations of components applied to dynamic studies. Then the component models that compose the system are validated and analyzed based on the experimental data. It also presents the integration of the proposed models of the hybrid system, simulating three different strategies or modes of operation as a case study. The developed model has the function of helping these studies, simplifying the analysis and providing different possibilities of simulations in short processing time. The principal aim of the work is to make available a computational model able to simulate in detail the behavior of a hybrid system in connected or isolated of conventional power grid operation conditions.