1,721,373 research outputs found
Experiments on virtual private network design with concave capacity costs
No full textFor the first time in the literature, this paper considers computational aspects of concave cost virtual private network design problems. It introduces careful bound tightening mechanisms and computationally demonstrates how such bound tightening could impressively improve convex relaxations of the problem. It turns out that, incorporating such bound tightening with a general solution approach could significantly enhance the behavior of the solution approach over the problem
A study of open innovation in facilitating environmental sustainability in road transport innovation networks
No full textOpen innovation is a new approach in innovation studies emphasize at opening the boundaries of the firm for exchanging the knowledge and R&D achievements with other enterprises, research centres and even competitors. As innovation plays a key role in achieving sustainable development goals and among them environmental sustainability, the effect of open innovation in facilitating the innovation process in transport sector will be discussed in this paper. Three indicators of open innovation have been analysed in order to identify how they can affect the number of firms which could introduce new innovations to the market in European Union countries. These indicators are: cooperation, acquisition of external resources and patents registered for electric and hybrid vehicles. The results of this study showed that while the cooperative and acquisition activities has a significant effect on the number of firms which could introduce new innovation to the market the effect of electric hybrid vehicle patents toward mitigating goals (reducing transport sector GHG emission) can't be judged using the existing data, as this indicator is related to the car manufacturers while some major manufacturing companies located in US and Japan and were outside geographical region of the study.
Purpose the study aimed at discussing how the success of firms in launching innovations to the market is affected by open innovation in road transport sector.
Design/methodology/approach- An explorative study related to the environmental innovations in transport sector has been conducted based on a mixed research approach, The data gathering methods is based on analysing data from OECD database, community innovation survey results (2010) derived from Eurostat database. Statistical analysis includes analysis of variances and regression analysis.
Originality/value - The study allows contributing to fill the gap in literature between open innovation and environmental sustainability in European Union using the network model for identifying the main players of innovative activities,
Practical implications-The results of the study shows the extent to what European firms are willing to share their innovation and how open innovation variables can affect the firm's ability in launching new innovations to the market.Open innovation is a new approach in innovation studies emphasize at opening the boundaries of the firm for exchanging the knowledge and R&D achievements with other enterprises, research centres and even competitors. As innovation plays a key role in achieving sustainable development goals and among them environmental sustainability, the effect of open innovation in facilitating the innovation process in transport sector will be discussed in this paper. Three indicators of open innovation have been analysed in order to identify how they can affect the number of firms which could introduce new innovations to the market in European Union countries. These indicators are: cooperation, acquisition of external resources and patents registered for electric and hybrid vehicles. The results of this study showed that while the cooperative and acquisition activities has a significant effect on the number of firms which could introduce new innovation to the market the effect of electric hybrid veh..
A long term analysis of stochastic theta methods for mean reverting linear process with jumps
No full textIn this paper a relative analysis of moments reversion of the class of theta methods is provided for an stochastic differential equation with Poisson-driven jumps. We first determine under which conditions the first and second moments revert to steady state values. Second, we consider two different classes of implicit theta methods; theta-Euler method, and compensated theta-Euler method, and derive closed-form expressions for the conditional and asymptotic means and variances of considered methods. We provide a full analysis about the possibility to find methods able to replicate such long-terms quantities. Finally, to verify our theoretical results numerical experiments are given
Variable stepsize multivalue collocation methods
No full textWhen faced with the task of solving stiff problems, highly stable numerical methods are often needed to avoid the phenomenon of order reduction. The purpose of this paper is to construct a family of high order multivalue collocation methods for the numerical solution of stiff problems and implement them in a variable stepsize environment. We construct a sixth order A-stable method with r=m+1, where m and r are the number of internal and external stages, respectively. The implementation issues of such methods in variable stepsize environments including starting procedure, stage predictors, local error estimation and the changing stepsize strategy are discussed. To show the efficiency and capability of constructed methods in solving stiff problems, some fixed and variable stepsize numerical experiments along with the reliability of local error estimation are presented
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
Local government's contribution to low carbon mobility transitions
Full text linkAn important area of urban sustainability planning refers to the reduction of environmental impacts. Transport sector is one of the main contributors of these impacts due to its role in air pollution, greenhouse gases and CO2 emissions. Effective actions are needed to limit the environmental impacts of transport activities. Transition studies focus on these types of actions and plans. The role of local authorities as the closest level of government to the citizens in managing transition process is highlighted because they can better understand, inform, and guide local inhabitants, businesses and industries for achieving sustainability targets.The paper aims at assessing the efforts of local public authorities in transition toward low carbon mobility in Italy. To achieve this aim a mixed method analysis was applied. First, the analysis of qualitative data obtained from interviews with urban mobility stakeholders; used to design a framework for evaluating the role of local government in transition process. Then a quantitative analysis conducted on the data gathered through a questionnaire distributed to a sample of mobility managers (or transport responsible) in municipalities. The analyses provided a final framework showing how municipalities influence low carbon mobility transition process in Italy. In conclusion, municipalities’ strategies and plans have a direct effect on the final goals. These strategies are influenced by financial support and cooperative activities, while the level of cooperation is dependent on the attitudes of deciding authorities. The paper also discusses the need to identify challenges and impediments for sustainable urban mobility transitions which was highlighted by stakeholders but less valued by local authorities
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
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