A spatial scan statistic for zero-inflated Poisson process

The scan statistic is widely used in spatial cluster detection applications of inhomogeneous Poisson processes. However, real data may present substantial departure from the underlying Poisson process. One of the possible departures has to do with zero excess. Some studies point out that when applied to data with excess zeros, the spatial scan statistic may produce biased inferences. In this work, we develop a closed-form scan statistic for cluster detection of spatial zero-inflated count data. We apply our methodology to simulated and real data. Our simulations revealed that the Scan-Poisson statistic steadily deteriorates as the number of zeros increases, producing biased inferences. On the other hand, our proposed Scan-ZIP and Scan-ZIP+EM statistics are, most of the time, either superior or comparable to the Scan-Poisson statistic

Cost, power consumption and performance analysis in SDM ROADM architectures for uncoupled spatial channels

Currently optical networks are reaching their maximum transport capacity. Different solutions can be used to overcome this capacity limit, but we are going to study, in particular, space division multiplexing (SDM). To use SDM, the reconfigurable optical add/drop multiplexers (ROADMs) need to be adapted to support this multiplexing. In this paper we analyze four switching strategies used in SDM ROADMs and the respective SDM ROADM architectures. These strategies are explained and analyzed, for uncoupled scenarios, in terms of cost and power consumption. The impact of the physical layer impairments (PLIs) amplified spontaneous emission noise, non-linear interference, passband narrowing due to optical filtering and in-band crosstalk is also assessed, considering a cascade of SDM ROADMs with spatial and spatial-wavelength switching granularities. The PLI inband crosstalk, has insignificant impact, in networks with a single spatial channel or in SDM networks with spatial granularity ROADM architecture, but in a SDM network with spatial wavelength granularity this PLI can lead to an OSNR penalty of around 2 dB, when the number of spatial channels is high. The other PLIs have similar impacts in all networks studied.info:eu-repo/semantics/acceptedVersio

Integrating a QPSK Quantum Key Distribution Link

We present the integration of the optical and electronic subsystems of a BB84-QKD fiber link. A highspeed FPGA MODEM generates the random QPSK sequences for a fiber-optic delayed self-homodyne scheme using APD detectors.Comment: 2 pages, 4 figures, European Conference on Optical Communication 200

Sistemas agroflorestais agroecológicos em Rondônia: espécies, idade dos plantios e origem dos agricultores.

Sistemas agroflorestais são uma opção de uso do solo muito propícia para pequenos agricultores na região Amazônica brasileira. Esta pesquisa objetivou determinar idade dos sistemas agroflorestais, quais as espécies perenes que ocorrem e seu uso por produtores agroecológicos em diferentes municípios do Estado de Rondônia, bem como origem dos produtores. Foram visitados 23 sistemas em 20 propriedades. Foram encontrados sistemas com a média de 17 anos de plantio, onde café é a cultura principal. As espécies florestais de maior ocorrência foram paricá (Schizolobium parahyba var. amazonicum (Huber ex Ducke), seguida de ipê (Tabebuia sp), cerejeira (Torresia acreana Ducke ) e teca (Tectona grandis L. f.).Resumos do VIII Congresso Brasileiro de Agroecologia. Porto Alegre/RS ? 25 a 28/11/2013. Trabalho número 14753

Levantamento detalhado de solos em uma área de reassentamento de colonos na Bacia do Jatobá - PE.

bitstream/CNPS-2010/14929/1/comtec41-2006-levant-jatoba.pd