1,720,977 research outputs found
Optimization of E-bike networks
No full textBattery-assisted bicycles, or E-bikes, are part of a disruptive wave of transportation technology that uses electricity and rechargeable batteries to increase the velocity, the traveled distance and, as a consequence, the ridership. Biking and E-biking are globally recognized to have the potential to play an important role in the transition to a Net-Zero society. The widespread availability of E-bikes is significantly impacting several sectors of the tourist industry. Therefore, Touristic Administrations (TAs) now provide tourists with trail options and the corresponding charging infrastructure for E-bikers with different profiles. Our main objective is to provide TAs with a suitable decision-support tool that serves two purposes: (1) finding locations for charging stations by considering the difficulty and the cost of installing such stations in remote, often off-the-road locations; and (2) designing itineraries that are suitable for different categories of E-bikers. In the scientific literature, the first decision component has been mostly addressed in the context of electric cars, and it is not suitable for E-bikes. On the other hand, works on the second decision focused on muscular bikes, thus ignoring the first decision component. In this paper, we aim at closing this gap. We formulate this problem as a mixed-integer linear program. We develop an efficient branch-and-cut algorithm and present a comprehensive computational experiment. In particular, we provide a case study in the Asiago Sette Comuni Plateau in Italy, where the obtained charging stations and bike trails maximize a measure of attractiveness for three types of users
A Benders Decomposition Approach for the Symmetric TSP with Generalized Latency Arising in the Design of Semiflexible Transit Systems
Full text linkWe present the symmetric traveling salesman problem with generalized latency (TSP-GL) a new problem arising in the planning of the important class of semiflexible transit systems. The TSP-GL can be seen as a very challenging variant of the symmetric traveling salesman problem (S-TSP), where the objective function combines the usual cost of the circuit with a routing component accounting for the passenger travel times. The main contributions of the paper include the formulation of the problems in terms of mul- ticommodity flows, the study of its mathematical properties, and the introduction of a branch-and-cut approach based on Benders reformulation taking advantage of properties that relate the feasible region of the TSP-GL and the S-TSP polyhedron. An extensive com- putational experimentation compares a number of variants of the proposed algorithm, as well as a commercial solver. These experiments show that the method we propose signif- icantly outperforms a well-known commercial solver and obtains good-quality solutions to realistically sized instances within short computational times
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
The Single-Line Design Problem for Demand-Adaptive Transit Systems: A Modeling Framework and Decomposition Approach for the Stationary-Demand Case
No full textWhen demand for transportation is low or sparse, traditional transit cannot pro- vide efficient and good-quality service, because of its fixed structure. For this reason, mass transit is evolving toward some degree of flexibility. Although the extension of Dial-a-Ride systems to general public meets such need of adaptability, it presents several drawbacks mostly related to the their extreme flexibility. Consequently, new transportation alterna- tives, such as demand-adaptive systems (DASs), combining characteristics from both the traditional transit and Dial-a-Ride, have been introduced. For their twofold nature, DASs require careful planning. We focus on tactical aspects of the planning process by formaliz- ing the single-line DAS design problem with stationary demand and proposing two alternative hierarchical decomposition approaches for its solution. The main motivation behind this work is to provide a general methodology suitable to be used as a tool to build the tactical DAS plan in real-life conditions. We provide an experimental study where the two pro- posed decomposition methods are compared and the general behavior of the systems is an- alyzed when altering some design parameters. Furthermore, we test the versatility of our methods on a variety of situation that may be encountered in real-life conditions
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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