Protocolo AODV com eficiência energética para plataforma android

Monografia (graduação)—Universidade de Brasília, Faculdade de Tecnologia, 2013.Os smartphones vêm se tornando cada dia mais populares e acessíveis. Os mais variados sistemas operacionais, propiciam aos usuários diversas aplicações, dentre elas várias que utilizam o acesso a redes para a comunicação como jogos, correio eletrônico e redes sociais. Com o advento da plataforma Android, sistema operacional para dispositivos móveis disponível em grande parte dos aparelhos celulares fabricados atualmente, surgem diversos trabalhos que focam no desenvolvimento de melhorias para estes dispositivos inclusive também no âmbito das redes. As redes ad hoc podem facilitar esta comunicação entre dispositivos em alguns cenários dispensando o uso de pontos de acesso e possibilitando a conexão direta entre os aparelhos usando técnicas de roteamento específicas para estas redes. Neste sentido, este trabalho apresenta uma implementação do protocolo de roteamento AODV (do inglês Ad hoc On-Demand Distance Vector) para formação de redes ad hoc de comunicações sem fio em dispositivos habilitados com a tecnologia Android, tendo como foco a eficiência energética da rede. Para tanto, foram sugeridas mudanças no protocolo AODV a fim de torná-lo um protocolo mais eficiente em termos energéticos. Para isso, foram introduzidas informações da bateria remanescente de cada nó da rede dentro dos cabeçalhos dos pacotes de controle do AODV. Esta informação se propaga através da rede e cada nó passa a saber a informação de bateria de cada nó da rede. Dessa forma, propomos também introduzir custos nas rotas baseado nessas informações energéticas. Esta medida evita que rotas sejam formadas por dispositivos ou rotas que estão próximas de ficarem sem bateria. Outro recurso introduzido é a criação de limiares que impedem a criação de rotas por dispositivos que estão com pouca bateria remanescente. Isso permite que o restante da bateria daquele dispositivo seja economizada. Utilizamos uma biblioteca desenvolvida para Android que executa o roteamento em redes ad hoc com o uso do AODV. Fizemos ainda melhorias nessa biblioteca que agora é capaz de iniciar e configurar a rede ad hoc por si mesma. Anteriormente este procedimento deveria ser feito manualmente antes da inicialização do protocolo de roteamento. Uma série de experimentos foi realizada com o objetivo de verificar o correto funcionamento do protocolo e seu desempenho.Smartphones are becoming increasingly more popular and less costly to the end user each day. Designed for working under various operating systems, a number of apps are available today, with many of them relying on communication networks for its operation, such as on-line games, e-mail, and social networks. With the advent of the Android platform---an operating system for mobile devices that is available in most cell phones today---a number of works have been done to improve the performance of these devices and their inter-netwoking as well. Ad hoc networks may facilitate communication among devices by avoiding the use of access points and by allowing direct communication among nodes through routing techniques that are specific to this kind of network. Based on that, this work presents an energy-efficient implementation of the Ad hoc On-Demand Distance Vector (AODV) routing protocol for Android smartphones. To accomplish that, information regarding remaining battery energy level at each node is embedded in the header of every AODV control message. As a result, information regarding each node's energy level is broadcast through the network, and each reachable node may receive energy information regarding every other node in the network. In addition, we propose the assignment of route costs based on energy information. This way, the routing protocol may avoid the selection of routes through nodes that are close to energy starvation. Another feature we introduce is the use of an energy threshold by which a node decides to not execute the routing functionality anymore and to inform, indirectly, the rest of the network about its decision. This allows fast path recovery and selection. Finally, an improvement to the basic AODV software is presented that allows self-initialization and self-configuration, as opposed to manual network setup. A set of experiments is performed and presented in order to evaluate correct protocol operation and performance

USE OF NANOCOMPOSITE HYDROGEL WITH N-UREA IN THE PRODUCTION OF EGGPLANT SEEDLINGS

The use of quality seedlings of eggplant is directly related to the success of their production, with polymers added to the substrate, which work as water conditioners, increase the water retention capacity, and provide better seedling quality. The study aimed to evaluate the use of nanocomposite hydrogel enriched with different proportions of N-urea in the production of eggplant seedlings. The experiment was conducted at the State University of Mato Grosso do Sul, Cassilândia, MS, Brazil, from June to August 2019, under sombrite® 30%. Five treatments were evaluated, using the commercial substrate, Carolina Soil®: 1) commercial substrate without hydrogel; 2) commercial substrate with 0.075g of pure hydrogel (0.00g of N-urea)/15 mL of a substrate; 3) commercial substrate with 0.075g of hydrogel and 10% N-urea/15 mL of a substrate; 4) commercial substrate with 0.075g of hydrogel and 20% N-urea/15 mL of a substrate, and 5) commercial substrate with 0.075g of hydrogel and 40% N-urea/15 mL of a substrate. The experiment was conducted with four replications of 25 seedlings. The emergence speed index, percentage of emergence, height, number of leaves, stem diameter, shoot dry matter, root dry matter, and total dry matter were evaluated, as well as the Dickson Quality Index. The data were subjected to analysis of variance (SPEEDSTAT statistical software) and grouping test of means. A regression analysis was performed to adjust equations for some of the variables. The best seedlings can be obtained using the dosage of 28.83% N-urea with 0.075g of hydrogel per 15 ml of the substrate, according to the DQI adjustment, which includes several traits of the seedlings, thus reflecting on its quality

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good