Analysis of noise in aircraft cabins through the VHF channel

Purpose - The purpose of this paper is to present a method to analyze the noise in aircraft cabins through the VHF Aeronautical Communication Channel, aimed at examining an environment that has the possibility of communication problems between the aircraft crew and the professionals responsible for the controls on land. Design/methodology/approach - This analysis includes equipment normally used for identification and comparison of electromagnetic noise, the cabin and the environment that are present in an airport, as well as equipment for frequency analysis and intensity of those signals. The analysis is done in a reverse way, eliminating situations that are not common in the examined environment, until the identification of the situation with the irregularity. Findings - According to the results, the implementation of the Fourier transform for noise analysis in the cabin was efficient. These results demonstrate that through this transformation, the noise sources can be identified in the environments in cases where there is much spectrum pollution. Research limitations/implications - This kind of noise analysis is important, considering the importance of having good accuracy in airport environment analysis. Originality/value - The paper presents the main trends in the future of aviation communications, and describes the new applications that aim to minimize problems with the current VHF channel.

A novel self consistent calculation approach for the capacitance-voltage characteristics of semiconductor quantum wire transistors based on a split-gate configuration

Purpose - The purpose of this paper is to develop an efficient numerical algorithm for the self-consistent solution of Schrodinger and Poisson equations in one-dimensional systems. The goal is to compute the charge-control and capacitance-voltage characteristics of quantum wire transistors. Design/methodology/approach - The paper presents a numerical formulation employing a non-uniform finite difference discretization scheme, in which the wavefunctions and electronic energy levels are obtained by solving the Schrodinger equation through the split-operator method while a relaxation method in the FTCS scheme ("Forward Time Centered Space") is used to solve the two-dimensional Poisson equation. Findings - The numerical model is validated by taking previously published results as a benchmark and then applying them to yield the charge-control characteristics and the capacitance-voltage relationship for a split-gate quantum wire device. Originality/value - The paper helps to fulfill the need for C-V models of quantum wire device. To do so, the authors implemented a straightforward calculation method for the two-dimensional electronic carrier density n(x,y). The formulation reduces the computational procedure to a much simpler problem, similar to the one-dimensional quantization case, significantly diminishing running time.

Genetic variation of the Ananas genus with ornamental potential

Brazil is one of the main centers of origin of pineapple species presenting the largest genetic variation of the Ananas genus. Embrapa Cassava and Fruits is a Brazilian Agricultural Research Corporation and has an ex-situ collection of 678 accessions of the Ananas genus and some other Bromeliaceae. The use of ornamental pineapple has increased in the last years demanding new varieties, mainly for the external market, due to the originality and colors of its tiny fruits. The main aim of the present study was describing accessions from the pineapple gene bank in order to quantify their genetic variation and identify possible progenitors to be used in breeding programs of ornamental pineapples. Eighty-nine accessions of Ananas comosus var. comosus, A. comosus var. bracteatus (Lindl.) Coppens et Leal, A. comosus var. ananassoides (Baker) Coppens et Leal, A. comosus var. erectifolius (L. B. Smith) Coppens et Leal, A. comosus var. parguasensis (Camargo et L. B. Smith) Coppens et Leal and A. macrodontes Morren were evaluated with 25 morphological descriptors. According to the results, the evaluated accessions were separated into the following categories: landscape plants, cut flower, potted plants, minifruits, foliage and hedge. The genetic distance among accessions was determined using the combined qualitative and quantitative data by the Gower algorithm. The pre-selected accessions presented genetic variation and ornamental potential for different uses. The multicategory analysis formed seven clusters through a classification method based on the average Euclidean distance between all accessions using the cut-point of genetic dissimilarity (D dg = 0.35). The genotypes A. comosus var. erectifolius were selected to be used as landscape plants, cut flower, minifruits and potted plants. Accessions of A. comosus var. bracteatus and A. macrodontes were selected as landscape plants and hedge. The highest variation was observed in A. comosus var. ananassoides genotypes, which presented high potential for use as cut flowers.

Knowledge management and strategic orientation: leveraging innovativeness and performance

Purpose - The aim of this study is to investigate whether knowledge management (KM) contributes to the development of strategic orientation and to enhance innovativeness, and whether these three factors contribute to improve business performance. Design/methodology/approach - A sample of 241 Brazilian companies was surveyed, using Web-based questionnaires with 54 questions, using ten-point scales to measure the degree of agreement on each item of each construct. Structural equation modeling techniques were applied for model assessment and analysis of the relationships among constructs. Exploratory factor analysis, confirmatory factor analysis, and path analysis using the technique of structural equation modeling were applied to the data. Findings - Effective KM contributes positively to strategic orientation. Although there is no significant direct effect of KM on innovativeness, the relationship is significant when mediated by strategic orientation. Similarly effective KM has no direct effect on business performance, but this relationship becomes statistically significant when mediated by strategic orientation and innovativeness. Research limitations/implications - The findings indicate that KM permeates all relationships among the constructs, corroborating the argument that knowledge is an essential organizational resource that leverages all value-creating activities. The results indicate that both KM and innovativeness produce significant impacts on performance when they are aligned with a strategic orientation that enables the organization to anticipate and respond to changing market conditions. Originality/value - There is a substantial body of research on several types of relationships involving KM, strategic orientation, innovativeness and performance. This study offers an original contribution by analyzing all of those constructs simultaneously using established scales so that comparative studies are possible.

An investigation about Brazilian mango and grape exports

Purpose - The objective of this paper is to characterise the transactions between European buyers and Brazilian mango and grape producers. Design/methodology/approach - The method selected for this paper was multiple case studies. The Brazilian mango and grape supply chains' export activities to Europe were investigated. The field research was undertaken in Brazil, Germany, The Netherlands and the UK. In total, 41 face-to-face interviews were carried out. Findings - The supermarkets' literature tends to generalise the strategies of retailers focusing on differentiation and preferred suppliers. However, in empirical research conducted in the UK, Germany and The Netherlands it is possible to conclude that the procurement strategies of supermarkets can vary sharply. The results reveal the presence of different agents who demand different quality standards. The level of intensity depends on consumer behaviour, the features of product commercialised and the characteristics of the production segment in each country. Research limitations/implications - First, in relation to the empirical method there is a limitation because the case study does not allow statistical generalisation. Consequently, it will be interesting to undertake quantitative research in order to quantify the variables presented and their impact on the structure of value chains. Second, the research focuses only on two stages of the supply chain, producers and buyers. Practical implications - The differences between UK and German supermarkets challenge the supermarket literature, which tends to generalise the strategies of retailers focusing on differentiation and preferred suppliers. Originality/value - The study shows that the issue of influence and activities of retail agents along the value chain can be analysed taking several variables into consideration: the products commercialised; the distribution segment; and the consumer market. This result opens the way for analysing different structures of the value chain and the impact of these differences on the entry of producers for developing countries into the global market.

O Recuo Brutalista

Em conformidade com a dúvida de seu título, o difundido livro The New Brutalism: Ethic or Aesthetic? de Reyner Banham não é possível explicar o Brutalismo como manifestação artística coesa, dotada de consistência e reprodutibilidade formal. A citação de arquitetos famosos, porém divergentes, parece associar e comparar obras ásperas com a pretensão de reerguer uma arquitetura moderna considerada ascética, monótona e insuficiente e gera um teoricismo da aparência crua e do moralismo dos objetos. Discurso que oculta, ou desvia a atenção do retorno artístico à sublimidade e construção artesanal. O Brutalismo é aceito como evolução natural dos estágios modernos anteriores e sanciona artefatos toscos, pesados e inacabados como se fossem filiados ao processo moderno desinfestado. Esconde contradições e disfarça seu rompimento com o moderno para prolongar a expressão Movimento moderno. Mas o objeto claro, econômico e preciso é repudiado pelo consumidor e, por ser pouco representativo, o artista faz sua maquiagem com episódios contrastantes e monumentais na informalidade das cidades espontâneas. No entanto, parece possível suspender a noção positiva e corretiva do Brutalismo para entendê-lo como um recuo artístico vulgarizador que despreza aperfeiçoamento e afronta a atitude moderna com banalização conceptiva, exagero, figuralidade, musculação estrutural, grandeza tectônica, rudimento e rudeza. Assim, moralismo, retorno rústico e originalidade desqualificam a expressão International Style entendida como a culminação da arquitetura moderna do pós-guerra, ao depreciá-la como decadente, como produto imobiliário, comercial e corporativo a serviço do capital. Essa interpretação desvela uma crítica anti-industrial, portanto antimodernista e diversa da pós-modernidade, porém contestadora e realista para fornecer imagens à cultura e aos insensíveis à estrutura da forma moderna. Diverso da pós-modernidade pela dependência ao moderno e ausência de apelo popular. Tornada insignificante a configuração oportuna do artefato, o arquiteto tenta reter sua notabilidade artística, ou o prestígio que parece enfraquecer na aparência símile da especificação de catálogo, no rigor modular. Indispõe-se e repudia componentes, Standards e acabamentos impessoais da indústria da construção para insistir em autoria e inspiração, mas repete cacoetes estilísticos de época e o inexplicável uso intensivo de concreto bruto e aparente para sentir-se engajado e atualizado. Porém, é necessário distinguir obras de aparência severa concebidas pela atitude moderna mais autêntica das de concreto aparente em tipos ou configurações aberrantes. Para avançar na discussão do Brutalismo propõe-se entender este fenômeno com a substituição do juízo estético moderno de sentido visual postulado por Immanuel Kant (1724-1804) por um sentimento estético fácil e relacionado com a sensação da empatia, com a Einfühlung de Robert Vischer (1847-1933). Na época da cultura de massas, admite-se o rebaixamento das exigências no artefato e a adaptação brutalista com a transfiguração dos processos de arquitetura moderna. Assim, a forma é substituída pela figura ou pelo resumo material; a estrutura formal subjacente pelo ritmo e exposição da estrutura física; o reconhecimento visual pelo entusiasmo psicológico ou pelo impulso dionisíaco; a concepção substituída pelo partido, ou, ainda, pelo conceito; a sistematização e a ordem pela moldagem e a organização; a abstração e síntese pela originalidade e essencialidade, o sentido construtivo pela honestidade material; a identidade das partes pela fundição ou pela unicidade objetal e a residência pela cabana primitiva.