Differential Attenuation
Mostrando 1-12 de 49 artigos, teses e dissertações.
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1. Extension of the Misme and Fimbel model for the estimation of the cumulative distribution function of the differential rain attenuation between two converging terrestrial links
A distribution-free model is presented for the cumulative distribution function of the differential rain attenuation between two co-channel converging terrestrial links operating at frequencies above 10 GHz. This is accomplished through an extension of the Misme and Fimbel model, which determines the cumulative distribution of the rain attenuation on an isol
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06
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2. Optical cryptography through analog control of amplitude and delay of spectral slices: anlysis for NRZ and DQPSK signals. / Criptografia Ãptica mediante controle analÃgico da amplitude e do atraso de fatias espectrais: anÃlise para sinais NRZ e DQPSK.
This work investigates a technique to encrypt the optical signal for Transparent Optical Network, TON, in order to safeguard the confidentiality and guarantee the security of informations that are transmitted through the Telecommunications Network. The technique is assessed on the physical layer of the reference model for open systems interconnection, OSI, a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/11/2012
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3. ATTENUATION AND IMMUNOGENICITY OF A RECOMBINANT BOVINE HERPESVIRUS 5 DEFECTIVE IN GLYCOPROTEIN E AND THYMIDINE KINASE / ATENUAÇÃO E IMUNOGENICIDADE DE UMA CEPA RECOMBINANTE DO HERPESVÍRUS BOVINO TIPO 5 DEFECTIVA NA GLICOPROTEÍNA E E ENZIMA TIMIDINA QUINASE
O presente trabalho descreve a atenuação/virulência e imunogenicidade de uma cepa recombinante do herpesvírus bovino tipo 5 (BoHV-5) candidata a cepa vacinal. O recombinante BoHV-5gE/TKΔ foi construído a partir da cepa brasileira SV507/99 e contém deleções nos genes da glicoproteína E (gE) como marcador antigênico - e da enzima timidina quinas
Publicado em: 2010
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4. Identificação e expressão de genes da biossíntese do jasmonato na interação entre Theobroma cacao e Moniliophthora perniciosa / Identification and expression of genes associated with jasmonate biosynthesis in the Theobroma cacao and Moniliophthora perniciosa interaction
Witches broom disease of cacao (Theobroma cacao L.), caused by the basidiomycete Moniliophthora perniciosa is an important disease and the use of resistant varieties is the only economic and environmental long-term solution. Plant hormones are essential in the signaling network involved in the response against a variety of biotic and abiotic stresses. It is
Publicado em: 2009
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5. EXTENSION OF THE MISME AND FIMBEL MODEL FOR THE DETERMINATION OF THE CUMULATIVE DISTRIBUTION OF THE RAIN DIFFERENTIAL ATTENUATION BETWEEN TWO CONVERGING LINKS / EXTENSÃO DO MODELO DE MISME E FIMBEL PARA A DETERMINAÇÃO DA DISTRIBUIÇÃO CUMULATIVA DA ATENUAÇÃO DIFERENCIAL DEVIDA À CHUVA ENTRE DOIS ENLACES CONVERGENTES
In this work, we will develop a theoretical model based on an extension of the Misme and Fimbel model for the determination of the cumulative distribution of the rain differential attenuation between two converging links. Results from the developed model will be compared with measurements performed in the City of São Paulo and in Japan. Additionally, we wil
Publicado em: 2008
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6. Uma contribuiÃÃo ao estudo da sedimentaÃÃo gravitacional em batelada
Thickeners are equipments that uses the gravitational force as separating agent of suspended solid particle in liquid chains of industrial processes. The frequent use of the settlers in chemical industries is the reason of the interest on the development of studies on the subject. The batch sedimentation is the starting point for the project of continuous in
Publicado em: 2007
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7. PLANEJAMENTO DE SISTEMAS FIXOS PARA ACESSO SEM FIO EM FAIXA LARGA OPERANDO EM AMBIENTES ABERTOS EM FREQÜÊNCIAS ENTRE 10 E 66 GHZ / PLANNING OF OUTDOOR BROADBAND FIXED WIRELESS ACCESS SYSTEMS OPERATING AT 10-66 GHZ BAND
The development of outdoor fixed broadband wireless access (BWA) systems operating at 10-66 GHz frequency requires a carefully planning in order to maximizing the use of the bandwidth, maximizing network capacity, assuring minimum requirements of availability and minimizing costs in an environment and in a frequency band where the propagation of electromagne
Publicado em: 2006
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8. Sobre o calculo de atenuação e de atividade em tomografia por emissão a partir de dados de atividade / Activity and attenuation reconstruction for emission computed tomography using emisssion data only
This thesis eals with the problem of estimating the attenuation from activity ata in emission computed tomography.We present several new methods aiming at solving the main rawback of the problem:the `crosstalk`between activity and attenuation images.The first group of methods is base on iteratively solving a regularized maximum likelihood model and the secon
Publicado em: 2004
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9. MODELLING TO RAIN ATTENUATION EFECTS IN POINT-TO-POINT AND POINT-TO-MULTIPOINT TERRESTRIAL LINKS / MODELAMENTO DE EFEITOS DE ATENUAÇÃO POR CHUVAS EM ENLACES TERRESTRES PONTO-A-PONTO E PONTO-MULTIPONTO
The growing demand for broadband services such as high- speed data, video, audio and multimedia, has lead to the use of point-multipoint radio systems operating in frequencies above of 10 GHz, that are not yet allocated for other services and allow the use of the large bandwidths required by these services. At these frequencies, the main contribution for the
Publicado em: 2003
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10. Fractal ladder models and power law wave equations
The ultrasonic attenuation coefficient in mammalian tissue is approximated by a frequency-dependent power law for frequencies less than 100 MHz. To describe this power law behavior in soft tissue, a hierarchical fractal network model is proposed. The viscoelastic and self-similar properties of tissue are captured by a constitutive equation based on a lumped
Acoustical Society of America.
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11. Differential Transcription Attenuation of Rabies Virus Genes by Intergenic Regions: Generation of Recombinant Viruses Overexpressing the Polymerase Gene
Gene expression of nonsegmented negative-sense RNA viruses involves sequential synthesis of monocistronic mRNAs and transcriptional attenuation at gene borders resulting in a transcript gradient. To address the role of the heterogeneous rabies virus (RV) intergenic regions (IGRs) in transcription attenuation, we constructed bicistronic model RNAs in which tw
American Society for Microbiology.
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12. Unusual lipid structures selectively reduce the toxicity of amphotericin B.
Ribbon-like structures result when amphotericin B interacts with lipid in an aqueous environment. At high ratios of amphotericin to lipid these structures, which are lipid-stabilized amphotericin aggregates, become prevalent resulting in a dramatic attenuation of amphotericin-mediated mammalian cell, but not fungal cell, toxicity. Studies utilizing freeze-et