1,721,072 research outputs found
Forecasting Labour Market Indicators: Micro vs Macro
No full textThis work analyses the dynamics of a set of labour market indicators using micro-data instead of aggregate time series. The goal is to produce short-term (up to four quarters) forecasts of aggregate labour force participation rates, employment rates and unemployment rates and to compare the
performance of the repeated cross-sections predictor with that of the traditional time series estimators proposed in the literature. Exploiting the ISTAT continuous labour force survey, an extensive analysis of the trends is carried out in order to understand if different socio-demographic groups follow different trends. As trend heterogeneity between groups emerges, a cross-section estimator which decomposes behavioural and compositional effects may add useful information for out-of-the-sample predictions.
ARIMA, SARIMA and state space models are implemented and compared with the decomposed cross-section estimator which includes a logistic specification.
Through exponential smoothing, traditional time series can model the trend in a very efficient way.
Besides that, they are not able to catch compositional effects that are instead fundamental in the patterns of considered indicators. Average forecast errors of the cross section predictor, calculated on a rolling basis, show that the latter is competitive with the traditional models. It outperforms ARIMA and SARIMA. A crucial factor is that time series models improve their efficiency as the sample length increases. The proposed cross section estimator instead is built in order to work on a short sample length, like in the continuous labour force survey case
3,5-Di-t-butylcatechol as a ryanodine receptor agonist in rat intact skeletal muscle fibers
No full text3,5-Di-t-butylcatechol (DTCAT) stimulates the rat skeletal muscle sarcoplasmic reticulum ryanodine receptor (RyR). In the present study, its effects on the contractile response of diaphragm preparation were characterized using electrically stimulated phrenic nerve–diaphragm preparations and diaphragm strips. DTCAT reduced, concentration-dependently, twitch contraction of the phrenic nerve– diaphragm preparation evoked by both direct and indirect stimulation and increased spontaneous tone. Twitch amplitude reduction was irreversible, while the increase of spontaneous tone was only partially reversible upon DTCAT washout. In diaphragm strips, caffeine > 4-chloro-m-cresol >> 3,5-diisopropylcatechol = ryanodine > DTCAT enhanced spontaneous tone, whereas quercetin reduced it with all the compounds reducing twitch amplitude. DTCAT-induced contracture was partly dependent on extracellular Ca2+ influx and antagonized by a Cd2+/La3+ mixture. In intact skeletal muscle preparations, DTCAT behaved as a RyR agonist
Nonlinear silicon photonic signal processing devices for future optical networks
No full textIn this paper, we present a review on silicon-based nonlinear devices for all optical nonlinear processing of complex telecommunication signals. We discuss some recent developments achieved by our research group, through extensive collaborations with academic partners across Europe, on optical signal processing using silicon-germanium and amorphous silicon based waveguides as well as novel materials such as silicon rich silicon nitride and tantalum pentoxide. We review the performance of four wave mixing wavelength conversion applied on complex signals such as Differential Phase Shift Keying (DPSK), Quadrature Phase Shift Keying (QPSK), 16-Quadrature Amplitude Modulation (QAM) and 64-QAM that dramatically enhance the telecom signal spectral efficiency, paving the way to next generation terabit all-optical networks
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
AMI for nonlinearity mitigation in O-band transmission
No full textWe utilise the alternate mark inversion (AMI) scheme to mitigate the nonlinearity in O-band transmission. The results after transmission over 60km of SMF show that AMI outperforms the duobinary and on-off keying formats.</p
Strategies for wideband light generation in nonlinear multimode integrated waveguides
No full textIn this paper we discuss two strategies to achieve wideband light generation through intermodal nonlinear parametric processes in multimode integrated waveguides. We outline how the interplay among intermodal interactions and high dispersion may lead to the generation of light characterized by substantial power spectral density if compared to supercontinuum sources. These results are valid independently of the waveguide material; however, our numerical simulations focus on silicon waveguides, which are nowadays at the core of integrated photonics. The long-term vision is that by exploiting an adequate number of intermodal processes, widely tunable radiation having high-power spectral density can be generated in a broad portion of the transparency window of silicon
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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