1,720,956 research outputs found
Slow transformation of mechanically dehydroxylated kaolinite to kaolinite—an aged mechanochemically activated formamide-intercalated kaolinite study
No full textFormamide-intercalated high defect kaolinite which was mechanochemically activated for periods of time up to 6 h has been aged for up to 1 year. These modified materials were studied using a combination of X-ray diffraction, thermal analysis and DRIFT spectroscopy. Ageing of the formamide-intercalated mechanochemically activated kaolinite results in de-intercalation of the formamide and the de-intercalated kaolinite returns to its original d-spacing. Thermal analysis shows that the temperature of dehydration and dehydroxylation increase by up to 30 °C. The temperature of the dehydroxylation of the aged samples was identical to that of the untreated kaolinite. The DRIFT spectroscopy showed that the spectrum of the aged samples approached that of the untreated kaolinite. The kaolinite showed partial de-intercalation and the 6 h sample had reformed to a mineral resembling the untreated kaolinite. The process of ageing the mechanochemically activated kaolinite enabled the reformation of the kaolinite
A Novel Routing Strategy for Public, Wide Area ATM Networks
No full textIt is highly probable that future Asynchronous Transfer Mode (ATM) networks will be partitioned into several logical (virtual) networks which serve calls belonging to different traffic classes. Because logical networks can be configured quickly and easily, (virtual) network topologies may change frequently as a result of network management intervention, the unpredictability of the topology, combined with unpredictable network element failures and traffic bursts, means that simple, fixed or alternate, routing strategies cannot be used; a dynamic, adaptive routing algorithm is needed.
Most conventional adaptive routing algorithms rely on the availability of a database containing information on the current network status. This database is usually replicated in all nodes which calculate routes but may (exceptionally) be housed at a central site within the network. The establishment and maintenance of such a database, particularly if it is distributed, is a difficult task, especially in geographically large networks. The main concern IS keeping the database contents up-to-date so that the routing algorithm is working with accurate data. At regular intervals, or whenever a significant (threshold) change in network status is detected at any node, update messages are flooded through the network to refresh the database contents. The problem is that if the network is operating with economical traffic levels, updates may be frequent and the routing overhead therefore unacceptable.
This thesis proposes a new, original routing strategy called Surge Routing which solves the problem in a different way. It is not computationally demanding and does not rely on the existence of a large, time-sensitive, database. It uses controlled flooding to discover truly optimal routes. Separate routing decisions are made for outgoing and incoming paths so that it is possible that different (but optimal) routes will be selected for each direction of transmission.
The main advantages of Surge Routing are:
1. it is robust since faulty network elements do not participate in route making decisions;
2. the applied routing strategy can be altered as the network load changes;
3. it is fast because it explores all possible routes in parallel and it is accurate and robust because it uses actual network metrics, not potentially outdated. Hooded update information;
4. the routing function is always aware of the actual network topology, so that routing decisions always produce optimal paths.
Simulation results indicate that the traffic overhead generated by Surge Routing is acceptable. The traffic overhead generated by this new routing algorithm is larger than that of conventional adaptive routing techniques under heavy loads, but it is still less than 0.5% of the overall user traffic transmitted on the network.
Surge Routing is an adaptive routing technique which can provide better performance than existing routing techniques currently proposed for wide area ATM networks
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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