166,709 research outputs found
Architecture for Analysis of Streaming Data
While several attempts have been made to construct a scalable and flexible
architecture for analysis of streaming data, no general model to tackle this
task exists. Thus, our goal is to build a scalable and maintainable
architecture for performing analytics on streaming data.
To reach this goal, we introduce a 7-layered architecture consisting of
microservices and publish-subscribe software. Our study shows that this
architecture yields a good balance between scalability and maintainability due
to high cohesion and low coupling of the solution, as well as asynchronous
communication between the layers.
This architecture can help practitioners to improve their analytic solutions.
It is also of interest to academics, as it is a building block for a general
architecture for processing streaming data
TypEx : a type based approach to XML stream querying
We consider the topic of query evaluation over semistructured information streams, and XML data streams in particular. Streaming evaluation methods are necessarily eventdriven, which is in tension with high-level query models; in general, the more expressive the query language, the harder it is to translate queries into an event-based implementation with finite resource bounds
Relativistic bias in neutrino cosmologies
Halos and galaxies are tracers of the underlying dark matter structures.
While their bias is well understood in the case of a simple Universe composed
dominantly of dark matter, the relation becomes more complex in the presence of
massive neutrinos. Indeed massive neutrinos introduce rich dynamics in the
process of structure formation leading to scale-dependent bias. We study this
process from the perspective of general relativity employing a simple spherical
collapse model. We find a characteristic signature at the neutrino
free-streaming scale in addition to a large-scale feature from general
relativity. The scale-dependent halo bias opposes the suppression in the matter
distribution due to neutrino free-streaming and leads to corrections of a few
percent in the halo power spectrum. It is not only sensitive to the sum of the
neutrino-masses, but respond to the individual masses. Accurate models for the
neutrino bias are a crucial ingredient for the future data analysis and play an
important role in constraining the neutrino masses.Comment: 20 pages, 10 figure
Heuristics Miners for Streaming Event Data
More and more business activities are performed using information systems.
These systems produce such huge amounts of event data that existing systems are
unable to store and process them. Moreover, few processes are in steady-state
and due to changing circumstances processes evolve and systems need to adapt
continuously. Since conventional process discovery algorithms have been defined
for batch processing, it is difficult to apply them in such evolving
environments. Existing algorithms cannot cope with streaming event data and
tend to generate unreliable and obsolete results.
In this paper, we discuss the peculiarities of dealing with streaming event
data in the context of process mining. Subsequently, we present a general
framework for defining process mining algorithms in settings where it is
impossible to store all events over an extended period or where processes
evolve while being analyzed. We show how the Heuristics Miner, one of the most
effective process discovery algorithms for practical applications, can be
modified using this framework. Different stream-aware versions of the
Heuristics Miner are defined and implemented in ProM. Moreover, experimental
results on artificial and real logs are reported
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