1,720,960 research outputs found
Port Rail Shunting Optimization Problems
No full textThe work focuses on a particular section of the intermodal chain of freight transportation, which is the link between rail and sea transportation modes and happens in the maritime port area. Among this field, the study deals with the management of rail operations, called here rail shunting operations, that have to be performed in the port area.
Two optimization problems arises in this context. The first concerns the scheduling of the rail shunting operations, here called Port Rail Shunting Scheduling Problem (PRSSP). The second deals with the re-scheduling of the same operations in case of unpredictable events, here called Port Rail Shunting Re-Scheduling Problem (PRSRP). After a literature overview on the concerning studies, we concentrate on an innovative way to use the well known space-time networks as solution approach structure for both the above mentioned problems. The innovative structure has been called operation-time-space network and is deeply analyzed in a dedicated chapter.
A network flow model based on an operation-time-space network for solving PRSSP has been developed. It has been tested using random generated instances providing good results. The same model has been extended in order to solve PRSRP and it has been tested giving good results as well.
Finally, the models have been used to solve the real case of a port area located in Italy in order to test the applicability of the developed models to a real context. The tests have been executed using real data and provided good results confirming the possibility to apply the proposed approach in similar real problems
An optimization model to design a new cruise itinerary: the case of Costa Crociere
No full textThis work analyses the complex processes for the development of cruises' itineraries to offer on the market and proposes a mathematical model for determining a new itinerary maximizing revenues, customers satisfaction, while minimizing operative costs. This work represents one of the first attempt to apply optimization techniques to cruise shipping and has been realized in collaboration with Costa Crociere, a cruise company operating in Europe
An innovative operation‐time‐space network for solving different logistic problems with capacity and time constraints
No full textThis work describes an innovative operation-time-space network that can be easily adapted to model different logistic problems involving time and space decisions. In the recent literature, different time-space networks have been proposed to deal with specific requirements of problems arising in the logistic and transportation fields. The proposed network is able to deal with different types of capacity and time constraints that characterized the most part of logistic problems. The article explains how to construct the operation-time-space network, how to model time and capacity constraints of different types; moreover, it presents an application of this network to solve a logistic problem arising in the rail-sea exchange node, that is the scheduling of port rail shunting operations. Other applications are briefly introduced. Finally, the well-known quay crane scheduling problem is modeled, thanks to the operation-time-space network; the related flow model is tested by using a benchmark suite available in the literature
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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