18,418 research outputs found
A formal actor-based model for streaming the future
Asynchronous Actor-based programming has gained increasing attention as a model of concurrency and distribution. The Abstract Behavioral Specification (ABS) language is an actor-based programming language that has been developed for both the modeling and formal analysis of distributed systems. In ABS, actors are modeled as concurrent objects that communicate by asynchronous method calls. Return values are also communicated asynchronously via return statements and so-called futures. Many modern distributed software
Demonstration of Run-time Spatial Mapping of Streaming Applications to a Heterogeneous Multi-Processor System-on-Chip (MPSoC)
In this paper, the problem of spatial mapping is defined. Reasons are presented to show why performing spatial mappings at run-time is both necessary and desirable and criteria for the qualitative comparison of spatial mappings are introduced. An algorithm is described that implements a preliminary spatial mapper. The methods used in the algorithm are demonstrated with an illustrative example
Asynchronous programming in the abstract behavioural specification language
Chip manufacturers are rapidly moving towards so-called manycore chips with thousands of independent processors on the same silicon real estate. Current programming languages can only leverage the potential power by inserting code with low level concurrency constructs, sacrificing clarity. Alternatively, a programming language can integrate a thread of execution with a stable notion of identity, e.g., in active objects.Abstract Behavioural Specification (ABS) is a language for designing executable models of parallel and distributed object-oriented systems based on active objects, and is defined in terms of a formal operational semantics which enables a variety of static and dynamic analysis techniques for the ABS models.The overall goal of this thesis is to extend the asynchronous programming model and the corresponding analysis techniques in ABS.Algorithms and the Foundations of Software technolog
Taste and the algorithm
Today, a consistent part of our everyday interaction with art and aesthetic artefacts occurs through digital media, and our preferences and choices are systematically tracked and analyzed by algorithms in ways that are far from transparent. Our consumption is constantly documented, and then, we are fed back through tailored information. We are therefore witnessing the emergence of a complex interrelation between our aesthetic choices, their digital elaboration, and also the production of content and the dynamics of creative processes. All are involved in a process of mutual influences, and are partially determined by the invisible guiding hand of algorithms.
With regard to this topic, this paper will introduce some key issues concerning the role of algorithms in aesthetic domains, such as taste detection and formation, cultural consumption and production, and showing how aesthetics can contribute to the ongoing debate about the impact of todayās āalgorithmic cultureā
Lightweight Asynchronous Snapshots for Distributed Dataflows
Distributed stateful stream processing enables the deployment and execution
of large scale continuous computations in the cloud, targeting both low latency
and high throughput. One of the most fundamental challenges of this paradigm is
providing processing guarantees under potential failures. Existing approaches
rely on periodic global state snapshots that can be used for failure recovery.
Those approaches suffer from two main drawbacks. First, they often stall the
overall computation which impacts ingestion. Second, they eagerly persist all
records in transit along with the operation states which results in larger
snapshots than required. In this work we propose Asynchronous Barrier
Snapshotting (ABS), a lightweight algorithm suited for modern dataflow
execution engines that minimises space requirements. ABS persists only operator
states on acyclic execution topologies while keeping a minimal record log on
cyclic dataflows. We implemented ABS on Apache Flink, a distributed analytics
engine that supports stateful stream processing. Our evaluation shows that our
algorithm does not have a heavy impact on the execution, maintaining linear
scalability and performing well with frequent snapshots.Comment: 8 pages, 7 figure
Foundations and modelling of dynamic networks using Dynamic Graph Neural Networks: A survey
Dynamic networks are used in a wide range of fields, including social network
analysis, recommender systems, and epidemiology. Representing complex networks
as structures changing over time allow network models to leverage not only
structural but also temporal patterns. However, as dynamic network literature
stems from diverse fields and makes use of inconsistent terminology, it is
challenging to navigate. Meanwhile, graph neural networks (GNNs) have gained a
lot of attention in recent years for their ability to perform well on a range
of network science tasks, such as link prediction and node classification.
Despite the popularity of graph neural networks and the proven benefits of
dynamic network models, there has been little focus on graph neural networks
for dynamic networks. To address the challenges resulting from the fact that
this research crosses diverse fields as well as to survey dynamic graph neural
networks, this work is split into two main parts. First, to address the
ambiguity of the dynamic network terminology we establish a foundation of
dynamic networks with consistent, detailed terminology and notation. Second, we
present a comprehensive survey of dynamic graph neural network models using the
proposed terminologyComment: 28 pages, 9 figures, 8 table
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