1,721,012 research outputs found
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
Mobile Agents Integrity for Electronic Commerce Applications
No full textThe Mobile Agent (MA) paradigm proposes a new approach for designing applications in open and heterogeneous distributed environments. Several application areas can benefit from the adoption of the MA technology, because it can support electronic commerce transactions and help in information gathering, filtering, and negotiation. MA solutions provide mobility, autonomy and easy personalization, but still lack a comprehensive and widely accepted security framework. Only a full answer to the requirement of protection for both execution sites and mobile shopping agents can leverage the adoption of MA solutions in the electronic commerce area. This paper proposes an MA environment to support secure and open electronic commerce applications. In particular, the paper focuses on how mobile shopping agents can be protected from malicious behaviour of execution sites and presents a range of solution strategies. The first solution makes use of a Trusted Third Party entity, while the second one is based on a distributed approach that does not assume the presence of trusted entities. In addition, these two solutions are integrated in a combined one. The paper compares the different approaches and describes their implementation performance
Large HSDI CR diesel engines multiple injections and multiple swirls concept
No full textAll future power developments should consider as primary tasks the achievement of the required emission levels and CO2-values, while still providing optimum torque-to-rpm curves, the lowest SFC (Specific Fuel Consumption) over the widest range possible, good power-to-weight and affordable costs. One method to achieve these objectives is the downsizing. To achieve the levels of engine performance that are required, a significant increase in the rated speed and in the boost pressure is mandatory. In this case, the result is an increase in the flow rate through the intake and exhaust ports and valves. Considering the impact of these changes, the port layout of the system is reanalyzed. Another physical limit to the maximum speed depends on the CR (Common Rail) injector dynamic performances. These performances decrease with size for inertia problems and they depend on the amount of effort involved in their development. Automotive engines in the range of 10 to 100 HP per cylinder are the most common. For this reason, these injectors are the most advanced and costeffective. Furthermore, their small size and inertia is favorable to the best dynamic performance. The larger number of nozzles improves combustion performance. In fact the better surface to volume ratio or the spray improves heat transfer. For this reason, multiple injection systems can be used in the modern HSDI (High Speed Direct Injection) CR large diesels. This solution was commonplace before WWII, but has been progressively abandoned with the introduction of mechanical high-pressure injection systems and the bowl combustion chamber. In this paper, a dual combustion chamber per cylinder engine is considered. The primary purpose of this study is to examine the best port layout on a modern diesel combustion system and to introduce a new promising concept. The study included flow measurements of intake flow and CFD simulations of the flow field during intake. This design enables the formation of two homogenous swirls centered onto the injectors, with excellent flow coefficient. The design also allows an increase in volumetric efficiency combined with a reduction in flow losses. © 2006-2015 Asian Research Publishing Network (ARPN)
Coordination in context: Authentication, authorisation and topology in mobile agent applications
No full textAdding the dimension of mobility to the engineering of complex software systems extends the scope of coordination. Since a mobile agent can roam a collection of different execution environments, physically distributed and possibly heterogeneous, interacting with both local resources and other mobile agents, both topology and security strictly relate to coordination. In this context, we propose an extension to the TuCSoN coordination model for Internet applications based on network-aware and mobile agents, which makes the coordination model coherently account for security and topology. TuCSoN defines a coordination space made up of a multiplicity of tuple centres, i.e., tuple spaces whose behaviour can be programmed to embed the laws of coordination, by means of specification tuples defining reactions to communication events
CFD analysis of the Zimmerman's V173 stol aircraft
No full textThe present work had as its main aim to carry out a study of the high lift of an unconventional aircraft of the '40s, the Vought V-173 Flying Pancake. To obtain this result the Authors used the Computational Fluid Dynamics (CFD) software SolidWorks Flow Simulation. In particular, the CL-αand CD-αcurves have been interpolated from the points obtained from the simulations for different configurations of the V173 aircraft CAD model. In a first phase the aerodynamics of the aircraft was evaluated 'clean' without the presence of the propellers was analysed. In a second phase, the influence of the two large propellers was taken into account. The effect of the propeller was clearly shown especially at high AOA. These results were obtained from the direct comparison of the Lift-AOA and Drag-AOA curves for the unpowered and the powered condition. The CFD results confirmed the impression of high controllability of the powered aircraft up to AOA of 50°. This behavior with the extremely smooth stall gave the impression of an aircraft impossible to stall or to spin. © 2006-2015 Asian Research Publishing Network (ARPN)
Life Cycle Assessment of an Axial Air Compressor Manufactured by the Firm FINI COMPRESSORI
No full textThis study was performed jointly by ENEA (Italian National Agency for New Technologies, Energy and Environment), Bologna and Florence Universities and the firm FINI COMPRESSORI. The functional unit is an axial air compressor manufactured by FINI COMPRESSORI, lubricated, having a 25-litres air tank, provided by 1.8 kW electrical motor. The system boundaries include raw material extraction and the end of life of the compressor. All metallic materials have the recycling as waste scenario. The LCA is obtained by using the SimaPro 3.1 code and the two methods Eco-indicator 95 and Ecopoints. The results show that air tank and stator of electrical motor are the components with greater environmental damage, even if the damage is mainly due to the electrical energy consumed during use
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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