1,721,036 research outputs found
DELAYED-REFERENCE CONTROL OF A TWO MASS ELASTIC SYSTEM
No full textAn innovative non-time-based control scheme for path tracking and vibration control of a two-mass system is introduced in this paper. The basic idea of the scheme, called delayed reference control (DRC), is to make the path reference of the system be a function of an action reference parameter which depends both on time and a variable which plays the role of a time delay. By suitably computing the value of the delay on the basis of the vibration measured, such vibration can be actively suppressed while an independent position regulator ensures an accurate tracking of the desired path. The DRC scheme is therefore suitable for those applications, in particular in the robotic field, where a pre-defined path through space must be followed precisely while the time taken to carry out the task is not a primary concern. In this paper the stability of the system is investigated, and numerical results are provided to assess the performance of the proposed method, compared to that of an optimal linear quadratic regulator
L’infanticidio in condizioni di abbandono morale e materiale. Una interpretazione giurisprudenziale
No full textProgressive contour coding in the wavelet domain
No full textThis paper presents a new wavelet-based image contour coding technique, suitable for representing either shapes or generic contour maps. Starting from a contour map (e.g. a segmentation map or the result of a contour extraction operator), this is first converted in a one-dimensional signal. Coordinate jumps among different contour extremities are converted, if under a suitable threshold, into signal discontinuities which can be compactly represented in the wavelet domain. Otherwise, the exceeding discontinuities are coded as side information. This side information is minimized by an optimized contour segment sequencing. The obtained 1D signal is decomposed and coded in the wavelet domain by using a 1D version of an improved implementation of the SPIHT algorithm. This technique can efficiently code every kind of 2D contour map, from one to many unconnected contour segments. It guarantees a fully embedded progressive coding, state-of-art coding performance, good approximation capabilities for both open and closed contours, and visually graceful degradation at low bit-rates
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
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
Knowledge of sexually transmitted diseases and condom use among female street workers in Padua
No full textOBJECTIVES: The aim of the present study was to investigate knowledge of sexually transmitted diseases (STDs) and condom use in a population of young female street sex workers from eastern Europe and other non-EU countries based in the Padua area (north-eastern Italy). To assess whether any aspects of their behavior might foster the spread of STDs.
STUDY DESIGN: Street sex workers (prostitutes) were approached on the streets or during non-STD medical appointments, their knowledge of STDs and condom use were evaluated. They were asked to answer an anonymous questionnaire comprising 16 questions.
RESULTS: 98 of them cooperated. Over one third of the sample frequently did not use a condom. This finding was inversely correlated with their age and educational level. Almost all the street sex workers were aware of AIDS but far less of other STDs. Most were almost totally unacquainted with some of them. We found a statistically significant correlation between condom use and their age, and between condom use and educational level.
CONCLUSIONS: Sex workers often engaged in unprotected intercourse with clients, they practiced their profession even in the presence of STD-related symptoms and did not use a condom during intercourse with non-paying partners or pimps. The irresponsible behavior of some Italian paying partners prepared to pay extra for unprotected sex, increases the risk of acquiring STDs. The intercourse with female street sex workers can be considered a risk behavior for contracting STDs
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