Caratterizzazione sperimentale di sistemi di comunicazione UWB

Questo elaborato presenta la caratterizzazione sperimentale di un sistema di comunicazione e localizzazione della DecaWave. Il sistema analizzato �è il kit EVK1000, che permette di e�ffettuare stime di distanza tra due nodi e una comunicazione robusta ai disturbi e immune alla propagazione multicammino grazie alla tecnologia UWB.

PIES time series in the North Atlantic at the Mid-Atlantic Ridge (2006-2010)

In the western North Atlantic, warm and saline water is brought by the North Atlantic Current (NAC) from the subtropics into the subpolar gyre. Four inverted echo sounders with high precision pressure sensors (PIES) were moored between 47°40' N and 52°30' N to study the main pathways of the NAC from the western into the eastern basin. The array configuration that forms three segments (northern, central, and southern) allows partitioning of the NAC and some assessment of NAC flow paths through the different Mid-Atlantic Ridge fracture zones. We exploit the correlation between the NAC transport measured between 2006 and 2010 and the geostrophic velocity from altimeter data to extend the time series of NAC transports to the period from 1992 to 2013. The mean NAC transport over the entire 21 years is 27 ± 5 Sv, consisting of 60% warm water of subtropical origin and 40% subpolar water. We did not find a significant trend in the total transport time series, but individual segments had opposing trends, leading to a more focused NAC in the central subsection and decreasing transports in the southern and northern segments. The spectral analysis exhibits several significant peaks. The two most prominent are around 120 days, identified as the time scale of meanders and eddies, and at 4-9 years, most likely related to the NAO. Transport composites for the years of highest and lowest NAO indices showed a significantly higher transport (+2.9 Sv) during strong NAO years, mainly in the southern segment.

O PLANEJAMENTO DA COMUNICAÇÃO ON-LINE: Como a velocidade no fluxo da informação altera a forma de planejar

O advento da internet causou uma revolução na forma como a sociedade se relaciona. A consolidação das mídias sociais na ambiência digital acentuou o poder das mudanças e forçou a comunicação a rever paradigmas. O imediatismo e a velocidade com que a informação se propaga num processo simétrico de mão dupla – emissor e receptor – mudou a forma de trabalhar, pensar e planejar. O presente trabalho traz uma pesquisa com profissionais de comunicação e analisa como o fator prazo tem impactado no processo do planejamento de longo prazo – tradicionalmente anual – das ações voltadas para o ambiente digital. A pesquisa baseou-se em amplo referencial teórico das áreas de comunicação, marketing, redes e mídias sociais, tecnologia, administração, além de institutos de pesquisas e empresas. A fim de descrever as experiências vividas pelos profissionais, empreendemos ainda uma pesquisa qualitativa com entrevistas em profundidade, com amostra não probabilística, com foco nas disciplinas de marketing e propaganda e relações públicas. Os resultados apontam para um aprendizado ainda sendo conquistado, dia após dia, a partir de tentativas e erros, onde a preocupação dos profissionais fica dividida entre o prazo de antecedência com que é feito um planejamento e a obrigatoriedade de sua revisão contínua.

Analysis of residuals in contingency tables: another nail in the coffin of conditional approaches to significance testing.

Omnibus tests of significance in contingency tables use statistics of the chi-square type. When the null is rejected, residual analyses are conducted to identify cells in which observed frequencies differ significantly from expected frequencies. Residual analyses are thus conditioned on a significant omnibus test. Conditional approaches have been shown to substantially alter type I error rates in cases involving t tests conditional on the results of a test of equality of variances, or tests of regression coefficients conditional on the results of tests of heteroscedasticity. We show that residual analyses conditional on a significant omnibus test are also affected by this problem, yielding type I error rates that can be up to 6 times larger than nominal rates, depending on the size of the table and the form of the marginal distributions. We explored several unconditional approaches in search for a method that maintains the nominal type I error rate and found out that a bootstrap correction for multiple testing achieved this goal. The validity of this approach is documented for two-way contingency tables in the contexts of tests of independence, tests of homogeneity, and fitting psychometric functions. Computer code in MATLAB and R to conduct these analyses is provided as Supplementary Material.

Barriers and facilitators to asthma self-management in adolescents:a systematic review of qualitative and quantitative studies

BACKGROUND: Many adolescents have poor asthma control and impaired quality of life despite the availability of modern pharmacotherapy. Research suggests that poor adherence to treatment and limited engagement in self-management could be contributing factors. OBJECTIVE: To conduct a systematic review of the barriers and facilitators to self-management of asthma reported by adolescents using a narrative synthesis approach to integrate the findings. DESIGN: MEDLINE, EMBASE, CINAHL, and PsycINFO were searched for all types of study design. Full papers were retrieved for study abstracts that included data from participants aged 12-18 years referring to barriers or facilitators of asthma self-management behaviors. RESULTS: Sixteen studies (5 quantitative and 11 qualitative) underwent data extraction, quality appraisal, and thematic analysis. Six key themes were generated that encompassed barriers and/or facilitators to self-management of asthma in adolescents: Knowledge, Lifestyle, Beliefs and Attitudes, Relationships, Intrapersonal Characteristics, and Communication. CONCLUSIONS: There is a pressing need to prepare adolescents for self-management, using age-appropriate strategies that draw on the evidence we have synthesized. Current clinical practice should focus on ensuring adolescents have the correct knowledge, beliefs, and positive attitude to self-manage their illness. This needs to be delivered in a supportive environment that facilitates two-way communication, fosters adolescents' self-efficacy to manage their disease, and considers the wider social influences that impinge on self-management. Pediatr Pulmonol. 2016; 9999:XX-XX. © 2016 Wiley Periodicals, Inc.

Essays on Intergenerational and Regional Aspects of Water Management

This dissertation consists of three essays on different aspects of water management. The first essay focuses on the sustainability of freshwater use by introducing the notion that altruistic parents do bequeath economic assets for their offspring. Constructing a two-period, over-lapping generational model, an optimal ratio of consumption and pollution for old and young generations in each period is determined. Optimal levels of water consumption and pollution change according to different parameters, such as, altruistic degree, natural recharge rate, and population growth. The second essay concerns water sharing between countries in the case of trans-boundary river basins. The paper recognizes that side payments fail to forge water-sharing agreement among the international community and that downstream countries have weak bargaining power. An interconnected game approach is developed by linking the water allocation issue with other non-water issues such as trade or border security problems, creating symmetry between countries in bargaining power. An interconnected game forces two countries to at least partially cooperate under some circumstances. The third essay introduces the concept of virtual water (VW) into a traditional international trade model in order to estimate water savings for a water scarce country. A two country, two products and two factors trade model is developed, which includes not only consumers and producer’s surplus, but also environmental externality of water use. The model shows that VW trade saves water and increases global and local welfare. This study should help policy makers to design appropriate subsidy or tax policy to promote water savings especially in water scarce countries.