1,721,018 research outputs found
Sulla determinazione sperimentale del coefficiente di trasmissione della radiazione solare in lastre piane alveolari
No full textOrigin-Destination Traffic Flow Modelling at Subregional Level
No full textStudies on tra±c °ows simulation and forecast have already lead to a signi ̄cant theoretical
corpus and to e®ective marketed packages. However, the current state of the art is not yet
fully satisfactory for local government agencies, especially for medium sized ones, because
of the operational constraints and of the inherent rigidity of currently available models and
software. Greater importance has to be given to data re ̄nement and to interactivity with the
operator, which, in turn, constrains response times. We developed an original methodology
for dealing with imprecise and not fully reliable input data by means of state of the art
optimization techniques, leading to an e®ective tra±c simulation package.
We pursued the two intertwined objectives of simulating/predicting tra±c °ows and of
re ̄ning origin/destination (OD) matrix input data. We worked at a regional level, corre-
sponding to a province in the Italian context. We built upon a legacy GIS-based application,
using a road network of about 10000 arcs, a superimposed region zoning decomposing the
area of interest into about 60 zones, each of which corresponds to a row/column of an OD
matrix, and 100 geocoded points, were actual tra±c counts were available.
We de ̄ned and calibrated a model, which makes use of the tra±c counts collected on the
arcs, of the OD matrix of the province and of physical characteristics of networks arcs, and
permits to identify tra±c °ows compatible with actual counts. This same model, after the
calibration of its parameters for the province network, has also been utilized for forecasting
new °ows following structural variations of the network. The application also contains an
OD matrix re ̄nement module which permits to update matrix entries as a function of the
actual tra±c counts.
We validated our model when supporting the de ̄nition of the so-called Territorial Plan
of Provincial Coordination" for the province of Forlμ3-Cesena, where we forecasted tra±c °ows
following the infrastructural scenarios included in the plan for the next 20 years
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
New route relaxation and pricing strategies for the vehicle routing problem
No full textIn this paper, we describe an effective exact method for solving both the capacitated vehicle routing problem (cvrp) and
the vehicle routing problem with time windows (vrptw) that improves the method proposed by Baldacci et al. [Baldacci,
R., N. Christofides, A. Mingozzi. 2008. An exact algorithm for the vehicle routing problem based on the set partitioning
formulation with additional cuts. Math. Programming 115(2) 351–385] for the cvrp. The proposed algorithm is based
on the set partitioning (SP) formulation of the problem. We introduce a new route relaxation called ng-route, used by
different dual ascent heuristics to find near-optimal dual solutions of the LP-relaxation of the SP model. We describe a
column-and-cut generation algorithm strengthened by valid inequalities that uses a new strategy for solving the pricing
problem. The new ng-route relaxation and the different dual solutions achieved allow us to generate a reduced SP problem
containing all routes of any optimal solution that is finally solved by an integer programming solver. The proposed method
solves four of the five open Solomon’s vrptw instances and significantly improves the running times of state-of-the-art
algorithms for both vrptw and cvrp
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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