1,722,258 research outputs found
The Robert D. Mason Co. (1911)
No full textPlan of a The Robert D. Mason Co. site in Pawtucket, Rhode Island from August 18, 1911.https://digitalcommons.usm.maine.edu/oml-athm-collection/1610/thumbnail.jp
Bringing together efficiency and effectiveness in distributed simulations: The experience with D-Mason
No full textAgent-based simulation models are an increasingly popular tool for research and management in many fields. In executing such simulations “speed” is one of the most general and important issues because of the size and complexity of simulations. But another important issue is the effectiveness of the solution, which consists of how easily usable and portable the solutions are for the users, i.e. the programmers of the distributed simulation. Our study, then, is aimed at efficient and effective distribute simulations by adopting a framewor-level approach, with our design and implementation of a framework, D-Mason, which is a parallel version of the Mason library for writing and running simulations of agent-based simulation models. In particular, besides the efficiency due to workload distribution with small overhead, D-Mason at a framework level proves itself effective since it enables the scientists that use the framework (domain expert but with limited knowledge of distributed programming) only minimally aware of the fact that the simulation is running on a distributed environment. Then, we present tests that compare D-Mason against Mason in order to assess the improved scalability and D-Mason capability to exploit heterogeneous distributed hardware. Our tests also show that several massive simulations that are impossible to execute on Mason (e.g. because of CPU and/or memory requirements) can be easily performed using D-Mason
D-MASON on the cloud: An experience with amazon web services
No full textD-Mason framework is a parallel version of the Mason library for writing and running Agent-based simulations – a class of models that, by simulating the behavior of multiple agents, aims to emulate and/or predict complex phenomena. D-Mason has been conceived to harness the amount of unused computing power available in common installations like educational laboratory. Then the focus moved to dedicated installation, such as massively parallel machines or supercomputing centers. In this paper, D-Mason takes another step forward and now it canbeusedonacloudenvironment. The goal of the paper is twofold. Firstly, we are going to present D-Mason on the cloud – a D-Mason extension that, starting from an IaaS (Infrastructure as a Service) abstraction, and exploiting Amazon Web Services and StarCluster, provides a SIMulation-as-a-Service (SIMaaS) abstraction that simplifies the process of setting up and running distributed simulations in the cloud. Secondly, an additional goal of the paper is to assess computational and economic efficiency of running distributed multi-agent simulations on the Amazon Web Services EC2 instances. The computational speed and costs of an EC2 cluster will be compared against an on-site HPC cluster
Exploiting D-Mason on parallel platforms: A novel communication strategy
No full textAgent-based simulation models are a powerful experimental tool for research and management in many scientific and technological fields.D-Mason is a parallel version of Mason, a library for writing and running Agent-based simulations.In this paper, we present a novel development of D-Mason, a decentralized communication strategy which realizes a Publish/Subscribe paradigm through a layer based on the MPI standard. We show that our communication mechanism is much more scalable and efficient than the previous centralized one
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
Communication strategies in distributed agent-based simulations: The experience with D-Mason
No full textAgent-Based simulation Models (ABMs) are a very powerful experimental tool of analysis, used in many scientific and technological communities of researchers, to assess and predict the dynamic unfolding of a series of events or processes, according to the imposition of certain conditions, given by the analyst. The computing power usually represents a limit for such simulations and the traditional answer to the need for computing power is to invest in computer resources. D-Mason is a framework for parallelizing simulations developed on top of Mason toolkit. The goal of D-Mason is to exploit wasted computing power in a network of computers, eventually heterogeneous, as a research lab or a cluster of workstation. In this paper we present a novel communication strategy using Publish/ Subscribe paradigm through a layer based on the MPI Standard. © 2014 Springer-Verlag Berlin Heidelberg
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