1,991 research outputs found
Potencial de produção de biocarvão no Norte do Estado de Mato Grosso.
Muitas formas de processamento de resíduos têm sido utilizadas, dentre elas, a pirólise para obtenção de biocarvão. Este trabalho apresenta o potencial da região Norte do Estado de Mato Grosso em reaproveitar resíduos do processamento da madeira por meio da pirólise. Pretendeu-se levantar o montante de resíduos produzidos na região, buscando alternativas para solucionar um problema regional, convertendo esse problema em alternativa para beneficiar o setor agrícola. Para levantar o montante de madeira processada foram utilizados os dados obtidos pelo Anuário Estatístico de Mato Grosso ? 2007. A região possui grande potencial de produção principalmente pela proximidade com as fontes produtoras de resíduos e das áreas de aplicação. Estima-se que os resíduos gerados na Região Norte de Mato Grosso possam produzir cerca de 123.600 Mg de biocarvão, equivalente a 86.500 Mg ano-1 de carbono. Quantidade equivalente à compensação de 317.200 Mg de CO2 emitido, além do carbono fixo na madeira processada
Modeling quasi-dark states with Temporal Coupled-Mode Theory
Coupled resonators are commonly used to achieve tailored spectral responses
and allow novel functionalities in a broad range of applications, from optical
modulation and filtering in integrated photonic circuits to the study of
nonlinear dynamics in arrays of resonators. The Temporal Coupled-Mode Theory
(TCMT) provides a simple and general tool that is widely used to model these
devices and has proved to yield very good results in many different systems of
low-loss, weakly coupled resonators. Relying on TCMT to model coupled
resonators might however be misleading in some circumstances due to the
lumped-element nature of the model. In this article, we report an important
limitation of TCMT related to the prediction of dark states. Studying a coupled
system composed of three microring resonators, we demonstrate that TCMT
predicts the existence of a dark state that is in disagreement with
experimental observations and with the more general results obtained with the
Transfer Matrix Method (TMM) and the Finite-Difference Time-Domain (FDTD)
simulations. We identify the limitation in the TCMT model to be related to the
mechanism of excitation/decay of the supermodes and we propose a correction
that effectively reconciles the model with expected results. A comparison with
TMM and FDTD allows to verify both steady-state and transient solutions of the
modified-TCMT model. The proposed correction is derived from general
considerations, energy conservation and the non-resonant power circulating in
the system, therefore it provides good insight on how the TCMT model should be
modified to eventually account for the same limitation in a different
coupled-resonator design. Moreover, our discussion based on coupled microring
resonators can be useful for other electromagnetic resonant systems due to the
generality and far-reach of the TCMT formalism.Comment: 7 pages, 4 figure
A flexible algorithm to offload DAG applications for edge computing
Multi-access Edge Computing (MEC) is an enabling technology to leverage new
network applications, such as virtual/augmented reality, by providing faster
task processing at the network edge. This is done by deploying servers closer
to the end users to run the network applications. These applications are often
intensive in terms of task processing, memory usage, and communication; thus
mobile devices may take a long time or even not be able to run them
efficiently. By transferring (offloading) the execution of these applications
to the servers at the network edge, it is possible to achieve a lower
completion time (makespan) and meet application requirements. However,
offloading multiple entire applications to the edge server can overwhelm its
hardware and communication channel, as well as underutilize the mobile devices'
hardware. In this paper, network applications are modeled as Directed Acyclic
Graphs (DAGs) and partitioned into tasks, and only part of these tasks are
offloaded to the edge server. This is the DAG application partitioning and
offloading problem, which is known to be NP-hard. To approximate its solution,
this paper proposes the FlexDO algorithm. FlexDO combines a greedy phase with a
permutation phase to find a set of offloading decisions, and then chooses the
one that achieves the shortest makespan. FlexDO is compared with a proposal
from the literature and two baseline decisions, considering realistic DAG
applications extracted from the Alibaba Cluster Trace Program. Results show
that FlexDO is consistently only 3.9% to 8.9% above the optimal makespan in all
test scenarios, which include different levels of CPU availability, a
multi-user case, and different communication channel transmission rates. FlexDO
outperforms both baseline solutions by a wide margin, and is three times closer
to the optimal makespan than its competitor
Eficiência Relativa de Agricultores Familiares na Produção de Leite.
O objetivo deste trabalho foi avaliar a eficiência relativa na produção de leite de uma amostra de agricultores familiares do Estado do Paraná, que estão sob orientação técnica de extensionistas participantes do Projeto Balde Cheio. A avaliação foi feita utilizando-se o Método de Envelopamento de Dados ? DEA. A média da eficiência da amostra analisada foi de 92% evidenciando que o grupo de produtores foi muito eficiente na gestão da tecnologia empregada e a importância do extensionista como agente de transferência de tecnologia
Exact solution of the full RMSA problem in elastic optical networks
Exact solutions of the Routing, Modulation, and Spectrum Allocation (RMSA)
problem in Elastic Optical Networks (EONs), so that the number of admitted
demands is maximized while those of regenerators and frequency slots used are
minimized, require a complex ILP formulation taking into account frequency-slot
continuity and contiguity. We introduce the first such formulation, ending a
hiatus of some years since the last ILP formulation for a much simpler RMSA
variation was introduced. By exploiting a number of problem and solver
specificities, we use the NSFNET topology to illustrate the practicality and
importance of obtaining exact solutions.Comment: This work has been submitted to the IEEE for possible publication.
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Desenvolvimento de um ambiente facilitador de integração de ferramentas de mineração de textos.
O objetivo deste trabalho é criar um ambiente que integre as várias ferramentas desenvolvidas e utilizadas nos projetos Tiena (MOURA et al., 2010) e Ainfo6 (PRAXEDES et al., 2009)
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