1,720,962 research outputs found
Development of mathematical models and methods of task distribution in distributed computing system
No full textThe article deals with certain aspects of Grid and Grid modeling. Grid is a distributed softwarehardware environment based on new computation and job flow management structure, principally. For analyzing the problems related to the logics of user-resource interaction, there has been developed a general model scheme. Within that scheme the authors consider the models that allow the formulation of concrete mathematical tasks. The ways of solving the assigned tasks are discussed as well
Some Bayesian Queueing and Reliability Models
No full textThe Bayesian approach for certain tasks of queueing systems theory and reliability theory is
introduced. The method provides the randomization of system characteristics with regard of a priori
distributions of input parameters. This approach could be used, for instance, for calculating average
values and for construction of confidential intervals applicable for performance and reliability
characteristics of large groups of systems or devices
Decomposition of exponential G-networks, with dependent service and route change
No full textQueueing networks with negative customers (G-networks), Poisson flow of positive customers, multi-server exponential nodes, and dependent service at the different nodes are studied. Every customer arriving at the network is defined by a set of random parameters: customer route, the length of customer route, customer volume and its service time at each route stage as well. The arrival of a negative customer to a queuing system causes one of the ordinary (or “positive”) customers to be removed (or “killed”) if any is present. However, the “killed” customer does not quit the network but continues his way along the new random route. For such G-networks, the multidimensional stationary distribution of the network state probabilities is shown to be representable in product form
Analysis of multi-server queueing system with semi-Markovian input flow and negative customers acted upon queue end
No full textThe multi-server queueing system with a finite of an infinite buffer, with semi-Markovian input
flow (for positive and negative customers) and with Markovian Service Process (for positive
customers) whose the number of the states of the process and the intensities of the transitions
between phases depend on the number of the customers in the system is considered. An arriving
negative customer kills the one positive customer at the end of the queue. The relations and
algorithms for computation of the steady-state probabilities and for calculation of the steadystate
distribution of waiting time of positive customer are received. It is shown how the multiserver
queueing system with semi-Markovian input flow, the servicing of the phase type and
the above mentioned order of act of the negative customers can be bring to the general queuing
system
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
A two-priority queueing system with trunk reservation, infinite capacity buffers for customers of both priorities, and different service intensities for high-priority and non-priority customers
No full textA two-priority queueing system with trunk reservation,
Poisson input flows of both priorities customers, infinite buffers and different
exponential distributions of both priorities customers service times
is considered. Trunk reservation means that there are some
channels which can be used only by customers of high priority. Analytic
relations to calculate the main stationary distributions of both priorities
customers quantities are obtained
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
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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