Designing a 161-element Ku-band microstrip reflectarray of variable size patches using an equivalent unit cell waveguide approach

An equivalent unit cell waveguide approach (WGA) to designing 4 multilayer microstrip reflectarray of variable size patches is presented. In this approach, a normal incidence of a plane wave on an infinite periodic array of radiating elements is considered to obtain reflection coefficient phase curves for the reflectarray's elements. It is shown that this problem is equivalent to the problem of reflection of the dominant TEM mode in a waveguide with patches interleaved by layers of dielectric. This waveguide problem is solved using a field matching technique and a method of moments (MoM). Based on this solution, a fast computer algorithm is developed to generate reflection coefficient phase curves for a multilayer microstrip patch reflectarray. The validity of the developed algorithm is tested against alternative approaches and Agilent High Frequency Structure Simulator (HFSS). Having confirmed the validity of the WGA approach, a small offset feed two-layer microstrip patch array is designed and developed. This reflectarray is tested experimentally and shows good performance.

Zygosity Diagnosis in the Absence of Genotypic Data: An Approach Using Latent Class Analysis

For zygosity diagnosis in the absence of genotypic data, or in the recruitment phase of a twin study where only single twins from same-sex pairs are being screened, or to provide a test for sample duplication leading to the false identification of a dizygotic pair as monozygotic, the appropriate analysis of respondents' answers to questions about zygosity is critical. Using data from a young adult Australian twin cohort (N = 2094 complete pairs and 519 singleton twins from same-sex pairs with complete responses to all zygosity items), we show that application of latent class analysis (LCA), fitting a 2-class model, yields results that show good concordance with traditional methods of zygosity diagnosis, but with certain important advantages. These include the ability, in many cases, to assign zygosity with specified probability on the basis of responses of a single informant (advantageous when one zygosity type is being oversampled); and the ability to quantify the probability of misassignment of zygosity, allowing prioritization of cases for genotyping as well as identification of cases of probable laboratory error. Out of 242 twins (from 121 like-sex pairs) where genotypic data were available for zygosity confirmation, only a single case was identified of incorrect zygosity assignment by the latent class algorithm. Zygosity assignment for that single case was identified by the LCA as uncertain (probability of being a monozygotic twin only 76%), and the co-twin's responses clearly identified the pair as dizygotic (probability of being dizygotic 100%). In the absence of genotypic data, or as a safeguard against sample duplication, application of LCA for zygosity assignment or confirmation is strongly recommended.

Classical approach to interpretation of the charge-dependence of peptide mobilities obtained by capillary zone electrophoresis

Published mobility measurements obtained by capillary zone electrophoresis of human growth hormone peptides are described reasonably well by the classical theoretical relationships for electrophoretic migration. This conformity between theory and experiment has rendered possible a more critical assessment of a commonly employed empirical relationship between mobility (u), net charge (z) and molecular mass (M) of peptides in capillary electrophoresis. The assumed linear dependence between u and z/M-2/3 is shown to be an approximate description of a shallow curvilinear dependence convex to the abscissa. An improved procedure for the calculation of peptide charge (valence) is also described. (C) 2003 Elsevier B.V. All rights reserved.

Visual Biology of Hawaiian Coral Reef Fishes. III. Environmental Light and an Integrated Approach to the Ecology of Reef Fish Vision

In the previous two papers in this three-part series, we have examined visual pigments, ocular media transmission, and colors of the coral reef fish of Hawaii. This paper first details aspects of the light field and background colors at the microhabitat level on Hawaiian reefs and does so from the perspective and scale of fish living on the reef. Second, information from all three papers is combined in an attempt to examine trends in the visual ecology of reef inhabitants. Our goal is to begin to see fish the way they appear to other fish. Observations resulting from the combination of results in all three papers include the following. Yellow and blue colors on their own are strikingly well matched to backgrounds on the reef such as coral and bodies of horizontally viewed water. These colors, therefore, depending on context, may be important in camouflage as well as conspicuousness. The spectral characteristics of fish colors are correlated to the known spectral sensitivities in reef fish single cones and are tuned for maximum signal reliability when viewed against known backgrounds. The optimal positions of spectral sensitivity in a modeled dichromatic visual system are generally close to the sensitivities known for reef fish. Models also predict that both UV-sensitive and red-sensitive cone types are advantageous for a variety of tasks. UV-sensitive cones are known in some reef fish, red-sensitive cones have yet to be found. Labroid colors, which appear green or blue to us, may he matched to the far-red component of chlorophyll reflectance for camouflage. Red cave/hole dwelling reef fish are relatively poorly matched to the background they are often viewed against but this may be visually irrelevant. The model predicts that the task of distinguishing green algae from coral is optimized with a relatively long wavelength visual pigment pair. Herbivorous grazers whose visual pigments are known possess the longest sensitivities so far found. Labroid complex colors are highly contrasting complementary colors close up but combine, because of the spatial addition, which results from low visual resolution, at distance, to match background water colors remarkably well. Therefore, they are effective for simultaneous communication and camouflage.

Anaphoric choices in Japanese fictional novels: the discourse arrangement of noun phrases, zero and third person pronouns

By examining Japanese fictional novels, this article will discuss how anaphoric devices (noun phrases (NPs), third person pronouns (TPPs), and zero anaphors) are selected and arranged in a given discourse. The traditional view of anaphora considers the co-referential relationship between anaphoric devices to be syntagmatic; that is, a pronoun, for example, refers back to its antecedent. It also declares the hierarchical order of information values between anaphoric devices; NPs are semantically the most informative, indicating an episode boundary, and pronouns less informative. Furthermore, zero anaphora is the most referentially transparent, showing the most accessibility of a topic. However, real text shows the contrary. NPs occur frequently while there is no apparent discourse boundary, and the same episode is continuous. This is because zero anaphors and TPPs (if they occur) break down readily due to the nature of a forthcoming sentence and the NP is reinstated, in order to continue the same topic in a given discourse. Therefore, the article opposes the traditional view of anaphora. Based on the concept of text processing, using ‘mental representations’, this article will determine certain occurrence patterns of the three anaphoric devices.

A genetic algorithm/method of moments approach to the optimization of an RF coil for MRI applications - Theoretical considerations - Abstract

A Combined Genetic Algorithm and Method of Moments design methods is presented for the design of unusual near-field antennas for use in Magnetic Resonance Imaging systems. The method is successfully applied to the design of an asymmetric coil structure for use at 190MHz and demonstrates excellent radiofrequency field homogeneity.

An approach to verifying and debugging simulation models governed by ordinary differential equations: Part 1. Methodology for residual generation

For dynamic simulations to be credible, verification of the computer code must be an integral part of the modelling process. This two-part paper describes a novel approach to verification through program testing and debugging. In Part 1, a methodology is presented for detecting and isolating coding errors using back-to-back testing. Residuals are generated by comparing the output of two independent implementations, in response to identical inputs. The key feature of the methodology is that a specially modified observer is created using one of the implementations, so as to impose an error-dependent structure on these residuals. Each error can be associated with a fixed and known subspace, permitting errors to be isolated to specific equations in the code. It is shown that the geometric properties extend to multiple errors in either one of the two implementations. Copyright (C) 2003 John Wiley Sons, Ltd.

An approach to verifying and debugging simulation models governed by ordinary differential equations: Part 2. Residuals analysis and a case study

In Part 1 of this paper a methodology for back-to-back testing of simulation software was described. Residuals with error-dependent geometric properties were generated. A set of potential coding errors was enumerated, along with a corresponding set of feature matrices, which describe the geometric properties imposed on the residuals by each of the errors. In this part of the paper, an algorithm is developed to isolate the coding errors present by analysing the residuals. A set of errors is isolated when the subspace spanned by their combined feature matrices corresponds to that of the residuals. Individual feature matrices are compared to the residuals and classified as 'definite', 'possible' or 'impossible'. The status of 'possible' errors is resolved using a dynamic subset testing algorithm. To demonstrate and validate the testing methodology presented in Part 1 and the isolation algorithm presented in Part 2, a case study is presented using a model for biological wastewater treatment. Both single and simultaneous errors that are deliberately introduced into the simulation code are correctly detected and isolated. Copyright (C) 2003 John Wiley Sons, Ltd.

A metalinguistic approach to deconstructing the concepts of 'face' and 'politeness' in Chinese, English and Japanese

In this paper we investigate the concepts of 'face' and 'politeness'. We introduce a metalanguage which we believe is a framework for simplifying the analysis of 'face' and 'politeness'. This metalanguage is based on the observation that both 'face' and 'politeness' involve external evaluations of people. This common element is represented in the metalanguage as B what A shows A thinks of B and what B thinks A thinks of B. The implications of the metalanguage for the analysis of Chinese mian and lion ('face') and English face are then discussed. This is followed by an analysis of examples of politeness in English and teineisa ('politeness') in Japanese. We conclude that the metalanguage may be further developed for use in comparisons of 'face' and 'politeness' across cultures. (C) 2003 Elsevier B.V. All rights reserved.

Balancing the number and size of sites: An economic approach to the optimal design of cluster samples

The design of randomized controlled trials entails decisions that have economic as well as statistical implications. In particular, the choice of an individual or cluster randomization design may affect the cost of achieving the desired level of power, other things being equal. Furthermore, if cluster randomization is chosen, the researcher must decide how to balance the number of clusters, or sites, and the size of each site. This article investigates these interrelated statistical and economic issues. Its principal purpose is to elucidate the statistical and economic trade-offs to assist researchers to employ randomized controlled trials that have desired economic, as well as statistical, properties. (C) 2003 Elsevier Inc. All rights reserved.

Quantum theory of the far-off-resonance continuous-wave Raman laser: Heisenberg-Langevin approach

We present the quantum theory of the far-off-resonance continuous-wave Raman laser using the Heisenberg-Langevin approach. We show that the simplified quantum Langevin equations for this system are mathematically identical to those of the nondegenerate optical parametric oscillator in the time domain with the following associations: pump pump, Stokes signal, and Raman coherence idler. We derive analytical results for both the steady-state behavior and the time-dependent noise spectra, using standard linearization procedures. In the semiclassical limit, these results match with previous purely semiclassical treatments, which yield excellent agreement with experimental observations. The analytical time-dependent results predict perfect photon statistics conversion from the pump to the Stokes and nonclassical behavior under certain operational conditions.

Crítica à concepção hegemônica de "erradicação da pobreza" : um estudo sobre a estratégia de naturalização e gestão da barbárie no Espírito Santo

Com base em pesquisa bibliográfica e documental, e fazendo uso da análise de conteúdo, este trabalho tem como objetivo geral analisar a meta erradicar a pobreza até 2025, constituinte do Plano de Desenvolvimento Espírito Santo 2025. Compreendemos que essa meta faz parte do modelo de ―desenvolvimento sustentado‖ elaborado pela burguesia capixaba, organizada no Movimento Empresarial Espírito Santo em Ação, e em articulação com o executivo estadual e a Petrobrás, sem que tenha havido participação de trabalhadores na elaboração do Plano mencionado. Seguem-se as principais conclusões. A meta em questão foi construída sob o marco ideopolítico e teórico da ―internacionalização do combate à pobreza‖, transpondo-se para o território estadual o discurso hegemônico de erradicação daquela condição social, entendida como sendo, em última análise, de responsabilidade do indivíduo, e não enquanto consequência direta do modo de produção capitalista. Além disso, os pobres são compreendidos, na elaboração da meta, de forma dual: ora identificados através do ―pressuposto da falta‖, ora enquanto ―agentes‖ livres para construir seu próprio futuro. Em consequência dessa dualidade, são propostas duas vias de ação tidas como essenciais para ―erradicar a pobreza‖: uma, centrada na transferência de renda para os que vivem na pobreza mais acentuada, e outra, na concessão de (micro)crédito para os pobres não miseráveis, com vistas a possibilitar que se tornem ―empreendedores‖. A meta analisada visa contribuir para promover a ―paz social‖, através da contenção dos pobres e de sua latente revolta diante de sua degradada condição de vida em território espírito-santense, o que demonstra sua funcionalidade para naturalizar e gerir a barbárie que marca a contemporaneidade capitalista.

O ethos no discurso político de Dilma Rousseff : a imagem da mulher na política

Este estudo propõe-se a analisar o discurso político de voz feminina, pela pers-pectiva da Análise do Discurso (AD) de linha francesa, a partir da escolha de quatro discursos proferidos pela presidente brasileira Dilma Rousseff, utilizan-do-se das contribuições trazidas por Dominique Maingueneau e Patrick Charaudeau. O eixo dessa pesquisa está no exame do ethos discursivo segundo as noções apresentadas pelos dois estudiosos, para a identificação das características de discurso político proferido por enunciador de voz feminina. Dos estudos de Maingueneau, além da categoria de ethos discursivo, são utilizadas as categorias de interdiscurso e de cenas de enunciação, especialmente as cenografias constituídas nos discursos políticos escolhidos. Das pesquisas semiolinguísticas de Charaudeau, privilegiamos as noções de ethos, de carisma e de pathos aplicadas ao discurso político, buscando caracterizar a maneira de ser e de dizer do sujeito enunciador, revelada pela patemização discursiva. Embora os dois pesquisadores tenham propostas teórico-metodológicas basilares diferentes, busca-se encontrar os pontos de complementação de abordagens para a caracterização do ethos discursivo de voz feminina. Os procedimentos de análises são precedidos por breve histórico do percurso, da participação e da presença da mulher na política nacional e internacional, principalmente nos séculos XX e XXI, a fim de compor o cenário histórico-social atual, uma vez que há o fato inédito e relevante de uma mulher tornar-se a primeira presidente do Brasil. As principais discussões realizadas neste estudo giram em torno aos macrotemas e microtemas dos discursos selecionados, suas cenografias ali constituídas, destacando as marcas, que influem na caracterização de ethos, incluindo aquelas propostas por Charaudeau, tais como, de autoridade, de credibilidade, de seriedade e de co-ragem. Associado a esses aspectos que ajudam a caracterizar o ethos, são analisados também os elementos constituintes da memória discursiva, articulando-os com as formações discursivas inerentes aos campos discursivos aos quais pertencem. Por fim, realiza-se uma síntese das análises empreendidas e conclui-se com o detalhamento da repercussão observada na imagem da mulher na política, discorrendo-se sobre ethos de enunciador de voz feminina em discurso político.