1,721,630 research outputs found
Adeguamento di una strada in relazione al sistema binario uomo-strada. Applicazione e verifica locale dei modelli esistenti riferiti al calcolo della velocità operativa
No full textNegli ultimi anni sono stati sviluppati numerosi modelli matematici che permettono di
calcolare la velocità operativa e/o la velocità ambientatale in funzione delle caratteristiche
geometriche e di progetto della strada.
Gli studi svolti, nell’ambito delle strade extraurbane a due corsie, hanno evidenziato che la
velocità di guida della maggior parte dei conducenti è superiore alla velocità di progetto, che
rappresenta, per molti Paesi, ancora il parametro di base in funzione del quale vengono calcolate
le principali caratteristiche geometriche e di progetto della strada.
In Italia nel Novembre del 2001 è entrata in vigore la nuova normativa stradale: le principali
caratteristiche geometriche e di progetto della strada sono calcolate sempre in funzione della
velocità di progetto. In Sardegna sono poche le strade che sono state progettate o adeguate
secondo la nuova normativa. Una di queste è la S.S. n. 125. Percorrendola è stato verificato che
la velocità di progetto in base alla quale è stata progettata è facilmente ed ampiamente
superabile.
L’articolo si incentra proprio su questa strada, applicando i modelli nazionali ed internazionali
sul rapporto tra conducente e caratteristiche geometriche e di progetto, essendo noto
l’andamento plano-altimetrico e presentando un tracciato che raccoglie diverse tipologie di
ambiente stradale. Nell’articolo vengono inizialmente riassunti i principali modelli nazionali ed
internazionali che consentono di calcolare la velocità operativa e/o la velocità ambientale. Per
ogni modello vengono riportate le relative ipotesi di base. Tra i modelli disponibili, sono stati
verificati quelli le cui ipotesi maggiormente si avvicinano alle caratteristiche della strada in esame.
È stato possibile, considerando differenti sezioni stradali, applicare più modelli che si basano su
ipotesi leggermente differenti. Successivi rilievi sul posto della velocità hanno permesso di
confermare o confutare i risultati ottenuti matematicamente. Il lavoro svolto ha l’obiettivo di
studiare i modelli esistenti, di implementare quelli italiani al fine di trovare un modello che leghi la
velocità del conducente anche a grandezze quali, ad esempio, la visibilità disponibile. Infine
vengono riportate possibili ipotesi d’intervento al fine di adeguare il comportamento di guida agli
standard di sicurezza offerti dalla strada
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
Experimental evaluation of PM emission from red mud basins exposed to wind erosion
Full text linkThe disposal of industrial and mineral processing residues represents a major concern for human health and the environment as a whole. In order to reduce the impact on soil and groundwater due to the waste leachability, the implementation of environmental regulations worldwide has favored the conversion of the disposal techniques from wet to dry (i.e., dry stacking or dry disposal). Such a change in the storage practice may cause the increase of particulate matter (PM) emission from the dry surfaces of the tailings exposed to wind erosion. Considering the significance of the environmental issue on a global scale and the increasingly stricter orientation of environmental policies, the need for modeling tools capable of estimating the contribution of tailing basins to air pollution becomes apparent. The paper deals with the disposal of red mud resulting from the bauxite processing in the alumina industry. An experimental research was carried with an environmental wind tunnel to estimate the Emission Factor (EF) of the basin surfaces as a function of the main affecting variables (i.e., residue water content and wind velocity). The article reports the results of the experimental test carried out on the red mud from a major basin located in Sardinia (Italy)
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
SHARING ARCHAEOLOGY IN THE MESS-AGE. ARCHAEOLOGY AS MATTER OF COMMUNICATION EXCHANGE AT THE SERVICE OF SOCIAL COHESION
No full textGreenways as Integrated Systems: A Proposal for Planning and Design Guidelines Based on Case Studies Evaluation
Full text linkGreenways (GWs) can play a key role in the context of policies and strategies for sustainable territorial development because they contribute to the development of integrated plans and interventions for environmental safeguarding and socio-economic growth. As is generally understood, in their modern conception, GWs are not only develop soft mobility, but they also represent supporting elements of a new concept of development and use of territory, attentive to its particular characteristics and the needs of resident populations. Beginning with a critical analysis of the most significant case studies of greenways, the authors propose a system of design and evaluation guidelines useful in identifying specific GW-related actions. The identified actions are divided into two categories, which are tangible and intangible actions. The first category corresponds with concrete actions that are directly implemented through different design and construction phases; the second category corresponds with processes activated in the design phase and are concretized after the “commissioning” of the path and has repercussions on the sphere of place identity. These categories are often difficult to distinguish between because many actions can be considered to be both tangible and intangible
- …
