1,813 research outputs found
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
Estimates of compensation and stability parameters in common bean lines aiming at multilines.
This study aimed to determine parameter estimates of compensation of common bean lines and verify if the stability of a mixture of lines is higher than of the line components. Six common bean lines were evaluated, pairwise, in equal proportions. The experiments were conducted in 11 environments, where the trait seed yield was evaluated (grams per plot). The positive ci estimate (compensation ability of line i) of cultivar Talismã was highest, indicating the line for mixtures. The combination of the pair Carioca and MA-II-16, with the highest positive sij estimate (specific compensation ability for the pair of lines i and j), was satisfactory. It was observed that the mean contribution of mixtures to the interaction was in the mean lower than of lines in monoculture. The stability was highest in the mixture Talismã and MA-II-8 and the risk of adoption lowest. The estimates of these compensation and stability parameters in mixtures underlying additional information are a support in the choice of lines to compose a multiline
NITROGEN FERTILIZATION AND INOCULATION OF COMMON BEAN WITH \u3ci\u3eRhizobium tropici\u3c/i\u3e
INTRODUCTION Common bean (Phaseolus vulgaris L.) has a great importance as a food crop worldwide and Brazil has a production about 3.29 million tons (FAO, 2014). Nitrogen (N) is the nutrient most absorbed and extracted by common bean and its use has a significant influence on yield. Due to the high cost of nitrogen fertilizers and the losses of this nutrient in the soil, which contributes to environmental pollution, it is of great interest to search for techniques that can maximize its efficiency. Although bean plants have the capacity to establish mutual symbiosis with bacteria, biotic and abiotic factors can act to reduce the efficiency of this relationship. This study aimed at evaluating the efficiency of inoculation practice with rhizobia and doses of nitrogen on production components of common bean
Treatment with warm water containing ethanol for controlling Salmonella spp. on post-harvest mangos.
Espacialização de notícias de cana-de-açúcar utilizando entidades do IBGE.
O foco deste trabalho é gerar a classificação manual de notícias agrícolas, de acordo com essas divisões geográficas, para serem utilizadas no âmbito do projeto "Tecnologias Inovadoras em mineração de textos para a Espacialização de Notícias Agrícolas" (TIENA). O objetivo dessa classificação é comparar resultados de classificação automática obtida por classificadores desenvolvidos no âmbito do projeto com os resultados manuais, a fim de validar os resultados automaticamente obtidos e encontrar formas de aprimorá-los
The SpatialCIM methodology for spatial document coverage disambiguation and the entity recognition process aided by linguistic techniques.
Abstract. Nowadays it is becoming more usual for users to take into account the geographical localization of the documents in the retrieval information process. However, the conventional retrieval information systems based on key-word matching do not consider which words can represent geographical entities that are spatially related to other entities in the document. This paper presents the SpatialCIM methodology, which is based on three steps: pre-processing, data expansion and disambiguation. In the pre-processing step, the entity recognition process is carried out with the support of the Rembrandt tool. Additionally, a comparison between the performances regarding the discovery of the location entities in the texts of the Rembrandt tool against the use of a controlled vocabulary corresponding to the Brazilian geographic locations are presented. For the comparison a set of geographic labeled news covering the sugar cane culture in the Portuguese language is used. The results showed a F-measure value increase for the Rembrandt tool from 45% in the non-disambiguated process to 0.50 after disambiguation and from 35% to 38% using the controlled vocabulary. Additionally, the results showed the Rembrandt tool has a minimal amplitude difference between precision and recall, although the controlled vocabulary has always the biggest recall values.GeoDoc 2012, PAKDD 2012
Desenvolvimento e produtividade de grãos de milho submetido a níveis de desfolha.
O objetivo deste trabalho foi avaliar a influência da desfolha do milho no desenvolvimento e na produtividade de grãos. Seis ensaios foram conduzidos em diferentes safras e locais e em dois níveis de produtividade. Utilizou-se o delineamento de blocos ao acaso, com sete repetições. A desfolha foi realizada no estádio vegetativo V4 do milho (quatro folhas expandidas), e os tratamentos foram: remoção das duas folhas basais, remoção das quatro folhas expandidas, remoção total das folhas (secção da parte aérea) e testemunha (sem desfolha). Foram avaliados: duração do período vegetativo; e, em pré‑colheita, altura de planta, altura de espiga, percentagem de plantas acamadas, força de quebramento de colmo, força de arranquio da planta e produtividade. A remoção das quatro folhas e a remoção total aumentaram a duração do período vegetativo e reduziram a altura de planta, a altura de espiga e a resistência do colmo ao quebramento. Esses níveis de desfolha também reduziram a produtividade, principalmente com a remoção total das folhas. A força de arranquio da planta não foi influenciada pela desfolha. A retirada de quatro folhas e do total das folhas reduz a produtividade de grãos, respectivamente, em 6,25 a 14,05% nos híbridos avaliados.Título em inglês: Grain development and yield in maize subjected to defoliation levels
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