We investigate the programming of reactive systems combining closed-loop control with performance-intensive components such as Machine Learning (ML). reactive control systems are often safety-critical and associated w...
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We investigate the programming of reactive systems combining closed-loop control with performance-intensive components such as Machine Learning (ML). reactive control systems are often safety-critical and associated with real-time execution requirements, a domain of predilection for synchronous programming languages. Extending the high levels of assurance found in reactive control systems to computationally intensive code remains an open issue. We tackle it by unifying concepts and algorithms from synchronous languages with abstractions commonly found in general-purpose and ML compilers. This unification across embedded and high-performance computing enables a high degree of reuse of compiler abstractions and code. We first recall commonalities between dataflowsynchronous languages and the static single assignment (SSA) form of general-purpose/ML compilers. We highlight the key mechanisms of synchronous languages that SSA does not cover-denotational concepts such as synchronizing computations with an external time base, cyclic and reactive I/O, as well as the operational notions of relaxing control flow dominance and the modeling of absent values. We discover that initialization-related static analyses and code generation aspects can be fully decoupled from other aspects of synchronous semantics such as memory management and causality analysis, the latter being covered by existing dominance-based algorithms of SSA-form compilers. We show how the SSA form can be seamlessly extended to enable all SSA-based transformations and optimizations on reactive programs with synchronous concurrency. We derive a compilation flow suitable for both high-performance and reactive aspects of a control application, by embedding the Lustre dataflow synchronous language into the SSA-based MLIR/LLVM compiler infrastructure. This allows the modeling of signal processing and deep neural network inference in the (closed) loop of feedback-directed control systems. With only minor efforts lev
IT transformation has revolutionized the business landscape and changed most of organizations business model into digital and innovation driven firms. To fully take advantage of this digitalization and the exponential...
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IT transformation has revolutionized the business landscape and changed most of organizations business model into digital and innovation driven firms. To fully take advantage of this digitalization and the exponential growth of data, organizations need to rely on resilient, scalable, extremely connected, highly available & very performant systems. To meet this need, this paper presents a model of middleware for multi micro-agents system based on reactive programming and designed for massively distributed systems and High-Performance Computing, especially to face big data challenges. This middleware is based on multi-agents systems (MAS) which are known as a reliable solution for High Performance Computing. This proposal framework is built on abstraction and modularity principles through a multi-layered architecture. The design choices aim to ensure cooperation between heterogeneous distributed systems by decoupling the communication model and the cognitive pattern of micro agents. To ensure high scalability and to overcome networks latency, the proposal architecture uses distribution model of data & computing, that allows an adaptation of the grid size as needed. The resilience problem is addressed by adopting the same mechanism as Hazelcast middleware, thanks to his peer-to-peer architecture with no single point of failure.
Two recent studies addressed the problem of reducing transitional turbulence in applications developed in C# on .NET. The first study investigated this problem in desktop and Web GUI applications and the second in vir...
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Two recent studies addressed the problem of reducing transitional turbulence in applications developed in C# on .NET. The first study investigated this problem in desktop and Web GUI applications and the second in virtual and augmented reality applications using the Unity3D game engine. The studies used similar solution approaches, but both were somewhat embedded in the details of their applications and implementation platforms. This paper examines these two families of applications and seeks to extract the common aspects of their problem definitions and solution approaches and codify the problem-solution pair as a new software design pattern. To do so, the paper adopts Wellhausen and Fiesser's writer's path methodology and follows it systematically to discover and write the pattern, recording the reasoning at each step. To evaluate the pattern, the paper applies it to an arbitrary C#/.NET GUI application. The resulting design pattern is named Dynamically Coalescing reactive Chains (DCRC). It enables the approach to transitional turbulence reduction to be reused across a range of related applications, languages, and user interface technologies. The detailed example of the writer's path can assist future pattern writers in navigating through the complications and subtleties of the pattern-writing process.
An interregional reactive programming model of the United States dairy industry is used to test the welfare implications of several dairy program changes on milk producers, milk consumers, and taxpayers. The results s...
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An interregional reactive programming model of the United States dairy industry is used to test the welfare implications of several dairy program changes on milk producers, milk consumers, and taxpayers. The results showed that each of the tested alternatives (price support reduction, price support reduction with frozen minimum Class I price, assessments, and production quotas) could reduce price support expenditures substantially. However, assessments reduced expenditures most effectively in terms of cost to milk producers for the United States generally while price support reduction with frozen minimum Class I price was most efficacious in terms of cost to Southeast producers.
作者：
Deleuze, Christophe
50 rue Barthélémy de Laffemas BP54 F-26902 Valence Cedex 09 France
reactive programming allows to write programs as a set of processes executing synchronously and communicating by signal broadcasting. This paradigm can be provided by specialized languages (sometimes based on "cl...
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reactive programming allows to write programs as a set of processes executing synchronously and communicating by signal broadcasting. This paradigm can be provided by specialized languages (sometimes based on "classic" languages) or by a library. reactiveML is such a language based on OCaml. We describe an OCaml library that provides reactiveML reactive constructs for the OCaml language. Processes must be written in trampolined style. Examples show the resulting style to be acceptable, and performances at least as good.
A complete guide on using data structures and algorithms to write sophisticated C# codeKey FeaturesLearn how to build reusable and maintainable code in C#.Delve into effective design and implementation techniques to m...
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ISBN:
(数字)9781788834681
ISBN:
(纸本)9781788833738
A complete guide on using data structures and algorithms to write sophisticated C# codeKey FeaturesLearn how to build reusable and maintainable code in C#.Delve into effective design and implementation techniques to meet your software requirementsExplore illustrations to present data structures and algorithms, as well as their analysis in a clear, visual *** DescriptionData structures allow organizing data efficiently. They are critical to various problems and their suitable implementation can provide a complete solution that acts like reusable code. In this book, you will learn how to use various data structures while developing in the C# language as well as how to implement some of the most common algorithms used with such data *** the beginning, you will get to know arrays, lists, dictionaries, and sets together with real-world examples of your application. Then, you will learn how to create and use stacks and queues. In the following part of the book, the more complex data structures will be introduced, namely trees and graphs, together with some algorithms for searching the shortest path in a graph. We will also discuss how to organize the code in a manageable, consistent, and extendable way. By the end of the book,you will learn how to build components that are easy to understand, debug, and use in different *** you will learnHow to use arrays and lists to get better results in complex scenariosImplement algorithms like the Tower of Hanoi on stacks of C# objectsBuild enhanced applications by using hashtables, dictionaries and setsMake a positive impact on efficiency of applications with tree traversalEffectively find the shortest path in the graphWho This Book Is ForThis book is for developers who would like to learn the Data Structures and Algorithms in C#. Basic C# programming knowledge would be an added advantage.
Modern systems are exposing an ever increasing degree of complexity also due to the heterogeneity of the involved components. Distributed simulation is widely recognized as an effective tool to carry out verification ...
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ISBN:
(纸本)9781728129235
Modern systems are exposing an ever increasing degree of complexity also due to the heterogeneity of the involved components. Distributed simulation is widely recognized as an effective tool to carry out verification and validation activities for heterogeneous and complex systems. Unfortunately, the use of distributed simulation frameworks and related implementation technologies require a proper modeling and simulation know-how, as well as a significant effort and software development skills. As a result, distributed simulation is not typically addressed by systems engineers who do not have the required expertise or background. The MONADS model-driven method has been introduced to overcome such limitations and provide systems engineers with the ability to properly carry out simulation-based verification and validation activities. The method specifically addresses the HLA (High Level Architecture) distributed simulation framework and introduces an automated approach to generate a significant portion of the HLA code from system models specified in SysML, the standard modeling language in the systems engineering field. The automatically obtained code is then to be finalized by a manual programming activity. This paper contributes to make easier and further reduce the effort of such a manual activity by integrating the reactive features of the RxHLA framework into the MONADS method. This integration enables the use of streams to effectively manage HLA-based asynchronous interactions. The paper describes the technical details of the various strategies that can be used to integrate RxHLA into the MONADS method, thus providing a significant degree of flexibility to MONADS users.
Terra is a system that combines the use of configurable component-based virtual machines with a reactive scripting language which can be statically analyzed to avoid unbounded execution and memory conflicts. This appr...
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ISBN:
(纸本)9780994988607
Terra is a system that combines the use of configurable component-based virtual machines with a reactive scripting language which can be statically analyzed to avoid unbounded execution and memory conflicts. This approach allows the flexibility of remotely uploading code on motes to be combined with a set of guarantees for the programmer. The choice of the specific set of components in a virtual machine configuration defines the abstraction level seen by the application script. In this work we demonstrate an instance of Terra with high-level abstractions for routing and grouping. We discuss how these abstractions allow the programmer to build a reasonably powerful application in a few lines of code and present the integrated environment that facilitates the development and testing of applications.
The [email protected] paradigm promotes the use of models during the execution of cyber-physical systems to represent their context and to reason about their runtime behaviour. However, current modeling techniques do ...
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ISBN:
(纸本)9781467369084
The [email protected] paradigm promotes the use of models during the execution of cyber-physical systems to represent their context and to reason about their runtime behaviour. However, current modeling techniques do not allow to cope at the same time with the large-scale, distributed, and constantly changing nature of these systems. In this paper, we introduce a distributed [email protected] approach, combining ideas from reactive programming, peer-to-peer distribution, and large-scale [email protected] We define distributed models as observable streams of chunks that are exchanged between nodes in a peer-to-peer manner. A lazy loading strategy allows to transparently access the complete virtual model from every node, although chunks are actually distributed across nodes. Observers and automatic reloading of chunks enable a reactive programming style. We integrated our approach into the Kevoree Modeling Framework and demonstrate that it enables frequently changing, reactive distributed models that can scale to millions of elements and several thousand nodes.
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