TCC - Bacharelado em Ciência da Computação (Sede)
URI permanente para esta coleçãohttps://arandu.ufrpe.br/handle/123456789/415
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Item Alocação dinâmica de recursos para URLLC em redes 5G NFV-MEC(2020-11-03) Souza, Caio Bruno Bezerra de; Araújo, Danilo Ricardo Barbosa de; Balieiro, Andson Marreiros; http://lattes.cnpq.br/9825617657358787; http://lattes.cnpq.br/2708354422178489; http://lattes.cnpq.br/5915479506163386The Fifth Generation of mobile networks (5G) seeks to support a diversity of applications categorized into three types: enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC) and Ultra Reliable Low Latency Communications (URLLC), where the latter is perhaps the most challenging due to its endtoend latency restrictions (few milliseconds), low probability of packet loss and high network availability, which are not reachable in today’s mobile networks. As in previous generations, much of the research effort has focused on the Radio Access Network (RAN), with the 5G core often assumed to be similar in operation to that of common data centers, although it is clear that they may not be able to handle the requirements of URLLC services. Support for URLLC applications in MultiAccess Edge Computing (MEC) environments using Network Functions Virtualization (NFV) brings challenges, in which different aspects must be considered. This work seeks to analyze the provisioning of resources for URLLC services in 5G networks based on MECNFV, considering the time of configuration / initialization of the Virtualized Network Function (VNF), the possibility of failure during service, associated with the preinitialization technique resources, determining the limits of how minimally performance the URLLC resource provisioning should be. For this purpose, an analytical model based on queue theory and validated via a simulator developed in a Colored Petri Net was proposed in this monograph and the average response time, the probability of blocking and the average number of active resources are analyzed under different service arrival rates, resource startup rates, maximum system capacity, number of resources (containers) and number of preinitialized containers. From this it was observed that the effect of the lower setup rate can be mitigated by the preinitialization of containers, reducing the waiting time for service delivery.Item Optimization of public transport networks by considering alternative positions for network stations(2024-02-20) Montarroyos, Ingo Porfírio Pastl; Araújo, Danilo Ricardo Barbosa de; http://lattes.cnpq.br/2708354422178489; http://lattes.cnpq.br/3644210138447014Nowadays, the planning of metropolitan areas considers improving the quality of life of inhabitants and urban mobility is one of the main concerns. Studies point out that investments in public transportation and other modes are aimed at the overall improvement of mobility. However, there is a gap in proper tools for optimizing public transport networks. In fact, network optimization is an NP-Hard problem and there are usually many conflicting objectives that need to be optimized simultaneously. This paper proposes the use of manyobjective evolutionary algorithms to address the problem of public transport networks optimization, focusing on metropolitan bus lines. The proposal consists in optimizing the position of bus stops and consequently obtaining new routes that pass through these stops in order to minimize the average travel time, the time spent between origin / destination and the variance of distance between the stops. To evaluate our proposal, a simulator was used to simulate the behavior of different passenger profiles in an urban area and the results were compared between the lines obtained by the optimization process and existing bus lines in the city of São Paulo. According to our results, optimized bus routes have mean travel time 22% less than the existing route and the time spent between origin/destination has decreased up to 18%.Item Projeto integrado de redes ópticas de longa distância e Metropolitanas usando algoritmos de inteligência computacional: estudo de caso para o estado de Pernambuco(2017) Nascimento, Jorge Candeias do; Araújo, Danilo Ricardo Barbosa de; http://lattes.cnpq.br/2708354422178489; http://lattes.cnpq.br/8065833426856653Nowadays, several network technologies with different prices and adaptations are appearing in the market. A network topology project involves several metrics; the metrics are used to evaluate a project. In the evaluation we use metrics such as robustness metrics (which help in the network’s ability to recover from a failure), blocking probability and energy consumption. The best way to optimize infrastructure in a network design would be to use the latest technologies, only the most efficient ones, even if such technologies are more expensive. However, of the metrics to be considered in this type of project, one of them is the cost (capital employed). Therefore, it is not always feasible to use the most expensive ones on the market. Many technical issues can help control the metrics of these projects, among which is the network topology (link interconnection). Multiobjective evolutionary algorithms (algorithms inspired by the evolution of the species) have been studied in the state of the art for the conception of network topologies. At the same time, clustering algorithms (algorithms specialized in separating samples into groups) have been used in other types of network studies. This study aimed to make use of computational intelligence algorithms in the construction of a network topology project, using the state of Pernambuco as a case study. In a first stage of the study, a clustering algorithm was used in the division of the state into groups. The intention of this part of the work was to measure the coverage of the network in relation to the entire size of the state, and thus ensure the completeness of the network. In addition, the clustering stage also aimed to propose a cost control model through the merging of different technologies for the network (Passive or active) depending on the function of the network segment. In a second step, an evolutionary multiobjective algorithm was used to compose several network topologies that served the clusters created in the previous step. This algorithm has evolved the various network topologies in order to improve four metrics, Blocking Probability, Cost, Energy Consumption and Algebraic Connectivity. The multiobjective algorithm was designed as a memetic algorithm, and, after a set of executions, the algorithm performances were compared with and without the alteration. The results of the tests, in the first stage, showed that the clustering techniques are quite efficient and adaptable to the proposed goal both in terms of network completeness and cost control. Already in the second stage, or multiobjective search stage, it was verified, through the use of a quality indicator (hypervolume), that there was an improvement of the algorithm in relation to convergence and diversity to the Pareto curve, with the use in its new form as memetic algorithm.Item Proposta de um meta-modelo para avaliação de robutez de redes de computadores com base na combinação de métricas topológicas(2017) Barros, Gustavo Henrique Pinto Soares de; Araújo, Danilo Ricardo Barbosa de; http://lattes.cnpq.br/2708354422178489; http://lattes.cnpq.br/1155438495823549A growing demand for resilience and robustness in the field of computer networks rises from the great diversity of its aplications. The modern sistems display an increasing critical nature, and the occurrence of perturbations may cause significant losses either human, monetary or environmental. Optical fiber acts on the current systems as the main mean of transportation. Among its variety of applications, which are heavily dependant on its infrastructure, some of them are the internet, cable television and high transmission rates systems. The non-homogeneous and complex topology nature of these networks determine their increasing avaluation cost. For these reasons, optical networks are the study object of this research. Quantifying the robustness of networks is usually accomplished by nodes and links failure simulations, on which the monetary and temporal cost scales proportionally to the network size. This research analyzes the possibility of obtaining values of robustness metrics in complex networks which would originally be obtained from simulations through an alternative regression method. This method has as inputs the values of simple metrics which are obtained through applications other than simulations and uses artificial neural networks to forecast simulation results in a smaller period. The results are obtained through a comparison between the proposed model output and the node and link failure simulation output. They indicate that the proposed model presents a satisfactory error margin, between 10−³ and 10−9, thus the simulation values were reached successfully through regression on a smaller time period.Item Redes ópticas de acesso: uma análise comparativa entre EPON e SuperPON(2024-12-12) Silva, Marcos Antonio da; Araújo, Danilo Ricardo Barbosa de; http://lattes.cnpq.br/2708354422178489The demand for high transmission rates for Internet services has been increasing over time, resulting in a large flow of data. This project focuses on access networks, which provide quality intemet services to homes and small business. Optical fiber offers high transmission rates, both for upstream and downstream, capable of transporting several Gbps, depending on the network architecture and equipment used, such as the OLT (Optical Line Terminal). Passive optical networks are access networks that use interconnected optical fibers in a star topology and point-to-multipoint configuration, consisting only of passive optical components between the Optical Line Terminal (OLT) and the Optical Network Unit (ONU). As a technological evolution strategy, they can be used to leverage the installed base of copper cables and coaxial cables in the access network, serving as feeder cables for technologies such as Digital Subscriber Line (DSL), cable modem, and Local Multipoint Distribution System (LMDS), and, in the future, to provide optical fiber to user premises. This project aims to show the difference between EPON and SuperPON technologies, both of which are passive network technologies, and to verify the cost-effectiveness of both. In this work, we explore the particularities of both technologies, considering the size of the network. We observe that EPON (Ethernet Passive Optical Network) stands out for its significantly lower cost compared to SuperPON when expanding the network to smaller areas. This is due to the lower need for expenses with CO (Central Office) and equipment. On the other hand, SuperPON presents a cost advantage when expanding to larger areas, as it requires less CO. Therefore, it becomes a more advantageous option compared to EPON in such network expansion scenarios. Another comparison we will address is the number of ONUs (Optical Network Unit) that we can obtain compared to EPON and SuperPON. In EPON, one fiber can support up to 64 ONUs in a network with a 1:8 splitter, resulting in 8 CTOs (Optical Termination Boxes). In a network with a 1:16 splitter, we can have 4 CTOs. On the other hand, in the SuperPON network, we can accommodate up to 1024 ONUS on a single fiber with a 1:8 splitter, resulting in 128 CTOs. With a 1:16 splitter, we can have 64 CTOs.Item Sentiment analysis of tweets related to SUS before and during COVID-19 pandemic(2021-02-19) Silva, Henrique Farias Pereira da; Andrade, Ermeson Carneiro de; Araújo, Danilo Ricardo Barbosa de; Dantas, Jamilson Ramalho; http://lattes.cnpq.br/5655706091153128; http://lattes.cnpq.br/2466077615273972; http://lattes.cnpq.br/9810796504568932The COVID-19 pandemic has affected the whole world since the beginning of 2020. In Brazil, over 70% of the population rely on the Brazil’s Unified Health System (SUS). Knowing public opinion related to SUS is very important for the improvement of services and assistance provided by such an entity. Sentiment analysis has been used in several applications including social networks and blogs to extract public opinion. Despite the fact that other papers have already worked with sentiment analysis, none of them have focused on SUS. Therefore, the goal of this paper is to analyse the sentiments shown by Brazillian Twitter users about SUS before and during COVID-19 pandemic. To reach this goal, a database of portuguese tweets regarding SUS posted between december 2019 and october 2020 was created. The tweets were pre-processed, classified and then analysed. The results show that, in most cases, users are in favor of SUS.Item Smart Tour PE: um aplicativo android para monitoramento remoto de pontos turísticos no estado Pernambuco(2021-07-13) Fonsêca, Eder Lucena Andrade da; Araújo, Danilo Ricardo Barbosa de; http://lattes.cnpq.br/2708354422178489; http://lattes.cnpq.br/9564226085565142The tourism sector has been growing sustainably since the 90s, and not even the period of economic downturn at the time was able to stop it. In recent years, around 2018 and 2019, the sector was breaking new records of international arrivals, with the COVID19 pandemic being the only “disaster” capable of stopping this success streak. More than a year after the beginning of the pandemic, thanks to the medical advances allowing the creation of effective vaccines and viable means to return to normality, it is expected that the search for tourist destinations will grow again very soon, with ecotourism being pointed out as the most likely niche to be sought after. Therefore, it is important that technological solutions are made available to support tourism, especially ecotourism. This undergraduate thesis is the idealization of a tool to help tourists dynamically choose their next travel destination based on the location’s real time weather. Accurate information about the climate will ensure that tourists make the most of their leisure time, being able to visit a place that most suits them, from beaches to tree lined hiking trails in preservation areas, based on climate reports. The real time weather reports from tourist attractions will be displayed through an application idealized in this undergraduate thesis, designed to work on mobile devices with internet access. This application will use information from weather stations installed in tourist attractions in the state of Pernambuco during the execution of the research project related to this undergraduate thesis, also offering the user geolocation data, video streaming from local cameras, routes to access the desired location, as well as additional information about utility telephones and a panic buttons for emergencies. According to usability tests carried out with the target audience, only 3% of them considered the application difficult to use and 97% considered it easy or extremely easy to use. In addition, the application scored 75 points in the Net Promoter Score indicator, with the average for the tourism sector in Brazil being 70 points, additionally to several other positive indicators to be explained later.Item Uso de técnicas de detecção de comunidades para análise de redes ópticas(2021-12-09) Barros, Jonas Freire de Alcântara Marques de; Araújo, Danilo Ricardo Barbosa de; http://lattes.cnpq.br/2708354422178489; http://lattes.cnpq.br/6917406943428049The growth in the use of services on the Internet has promoted a increasing demand for high transmission rates. This demand have been met by optical networks. At the design stage of these networks, the engineer must be able to assess the performance of a given network before its actual physical implementation. In this design process, several topologies are considered. The comparison between topologies is made through metrics that indicate a certain aspect of the network. Typically the metrics considered are performance indicators, such as Throughput, Blocking Probability, Resilience and also other indicators, such as the network Cost. Performance indicators are important because they inform about the quality of a particular topology. Therefore, performance metrics are essential for the design projects of such networks. The most reliable way to calculate the values of these performance indicators is through simulations. However, simulations have a high computational cost, increasing the time needed to obtain information about topologies; since, in these projects, a very large number of different topologies must be considered. On the other hand, a large number of researches in the most diverse domains of knowledge have been carried out on the theme of community detection in graphs. However, there are no applications of these techniques in high capacity fiber-optic networks. Thus, the present work aims to investigate the existence of a correlation between the ability of a fiber-optic network to form communities and its performance indicators. More specifically, it’s Blocking Probability and indicators of Resilience. The analysis was performed comparing the Blocking Probability and Resilience of these networks and the clustering metrics using scatter plots. According to the results, there is a positive correlation between the community metrics and the network performance indicators, and comparatively a speedup of approximately 4,500 times was obtained between the community metrics and the simulations.