We introduce the framework FreeCHR which formalizes the embedding of Constraint Handling Rules (CHR) into a host language, using the concept of initial algebra semantics from category theory, to establish a high-level...
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ISBN:
(纸本)9783031450716;9783031450723
We introduce the framework FreeCHR which formalizes the embedding of Constraint Handling Rules (CHR) into a host language, using the concept of initial algebra semantics from category theory, to establish a high-level implementation scheme for CHR as well as a common formalization for both theory and practice. We propose a lifting of the syntax of CHR via an endofunctor in the category Set and a lifting of the very abstract operational semantics of CHR into FreeCHR, using the free algebra, generated by the endofunctor and give proofs for soundness and completeness w.r.t. their original definition.
Data quality is essential for database integration, machine learning and data science in general. Despite the increasing number of tools for data preparation, the most tedious tasks of data wrangling -and feature mani...
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ISBN:
(纸本)9783030461331;9783030461324
Data quality is essential for database integration, machine learning and data science in general. Despite the increasing number of tools for data preparation, the most tedious tasks of data wrangling -and feature manipulation in particular- still resist automation partly because the problem strongly depends on domain information. For instance, if the strings "17th of August of 2017" and "2017-08-17" are to be formatted into "08/17/2017" to be properly recognised by a data analytics tool, humans usually process this in two steps: (1) they recognise that this is about dates and (2) they apply conversions that are specific to the date domain. However, the mechanisms to manipulate dates are very different from those to manipulate addresses. This requires huge amounts of background knowledge, which usually becomes a bottleneck as the diversity of domains and formats increases. In this paper we help alleviate this problem by using inductive programming (IP) with a dynamic background knowledge (BK) fuelled by a machine learning meta-model that selects the domain, the primitives (or both) from several descriptive features of the data wrangling problem. We illustrate these new alternatives for the automation of data format transformation, which we evaluate on an integrated benchmark and code for data wrangling, which we share publicly for the community.
This paper presents an architecture for monitoring the presentation of multimedia declarative applications, providing feedback about variables states, object properties, media presentation times, among others. Monitor...
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ISBN:
(纸本)9781479970827
This paper presents an architecture for monitoring the presentation of multimedia declarative applications, providing feedback about variables states, object properties, media presentation times, among others. Monitoring tools that follow the proposed architecture are able to detect if visual problems are being caused by programming errors or by player malfunctioning. The architecture presents a communication protocol designed to be independent of the declarative language used in the development of multimedia applications. The main goal is to provide an open and generic architecture that can assist multimedia application authors and presentation engine developers. As an example of the architecture use, the paper also presents a monitoring tool integrated into a graphical user interface developed for the ITU-T reference implementation of the Ginga-NCL middleware.
This paper presents a complete methodology for modeling gradings (also called non-full-availability groups) servicing single-service and multi-service traffic streams. The methodology worked out by the authors makes i...
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This paper presents a complete methodology for modeling gradings (also called non-full-availability groups) servicing single-service and multi-service traffic streams. The methodology worked out by the authors makes it possible to determine traffic characteristics of various types of gradings with state-dependent call arrival processes, including a new proposed structure of the Erlang's Ideal Grading with the multirate links. The elaborated models of the gradings can be used for modeling different systems of modern networks, for example, the radio interfaces of the UMTS system, switching networks carrying a mixture of different multirate traffic streams, and video-on-demand systems. The results of the analytical calculations are compared with the results of the simulation data for selected gradings, which confirm high accuracy of the proposed methodology.
The Communications Web site, http://***, features more than a dozen bloggers in the BLOG@CACM community. In each issue of Communications, we'll publish selected posts or excerpts.twitterFollow us on Twitter at htt...
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The Communications Web site, http://***, features more than a dozen bloggers in the BLOG@CACM community. In each issue of Communications, we'll publish selected posts or excerpts.
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Follow us on Twitter at http://***/blogCACM
http://***/blogs/blog-cacm
Michael Stonebraker issues a call to arms about research groups' data-management problems. Jason Hong discusses the nature of functionality with respect to design.
Haskell (Peyton Jones, 2003) is often used as a host language for embedding other languages. Typically, the abstract syntax of the guest language is defined by a collection of datatype declarations; parsers and pretty...
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Haskell (Peyton Jones, 2003) is often used as a host language for embedding other languages. Typically, the abstract syntax of the guest language is defined by a collection of datatype declarations; parsers and pretty-printers convert between the concrete syntax and its abstract representation. A quote/antiquote mechanism permits a tighter integration of the guest language into the host language by allowing one to use phrases in the guest language's concrete syntax. [ABSTRACT FROM AUTHOR]
Context-aware pervasive systems are an important emerging category of software, increasingly pervading into daily life, play and work. These systems are characterized by capabilities for sensing the physical world and...
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Context-aware pervasive systems are an important emerging category of software, increasingly pervading into daily life, play and work. These systems are characterized by capabilities for sensing the physical world and taking action, autonomously or in cooperation with users. This paper proposes an incremental approach to building context-aware pervasive systems, with a particular emphasis on systematically extending over time the contexts and situations a system can be aware of, and creating a formalism in which these systems can be composed. We present a formalism of operators for building context-aware pervasive systems incrementally and in a compositional manner (by combining multiple systems and subsystems), facilitating reuse in a formal way. The formalism can serve as: (i) a basis for a scripting language for programming composite systems, and (ii) a language for specifying these systems (whether existing or to be built) and then reasoning with specifications of these systems. (C) 2009 Elsevier B.V. All rights reserved.
declarative Networking is a programming methodology that enables developers to concisely specify network protocols and services, which are directly compiled to a dataflow framework that executes the specifications. Th...
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declarative Networking is a programming methodology that enables developers to concisely specify network protocols and services, which are directly compiled to a dataflow framework that executes the specifications. This paper provides an introduction to basic issues in declarative networking, including language design, optimization, and dataflow execution. We present the intuition behind declarativeprogramming of networks, including roots in Datalog, extensions for networked environments, and the semantics of long-running queries over network state. We focus on a sublanguage we call Network Datalog (NDlog), including execution strategies that provide crisp eventual consistency semantics with significant flexibility in execution. We also describe a more general language called Overlog, which makes some compromises between expressive richness and semantic guarantees. We provide an overview of declarative network protocols, with a focus on routing protocols and overlay networks. Finally, we highlight related work in declarative networking, and new declarative approaches to related problems.
We present two implementations of Oppen's pretty-printing algorithm in Haskell that meet the efficiency of Oppen's imperative Solution but have a simpler and a clear structure. We start with an implementation ...
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We present two implementations of Oppen's pretty-printing algorithm in Haskell that meet the efficiency of Oppen's imperative Solution but have a simpler and a clear structure. We start with an implementation that uses lazy evaluation to simulate two co-operating processes. Then we present an implementation that uses higher-order functions for delimited continuations to simulate co-routines with explicit scheduling.
The article discusses the use of the Erlang computer programming language. Erlang, a general-purpose concurrent programming language and runtime system, can be a valuable tool in solving concurrent problems, the artic...
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The article discusses the use of the Erlang computer programming language. Erlang, a general-purpose concurrent programming language and runtime system, can be a valuable tool in solving concurrent problems, the article states. It was developed in the 1980s by the Swedish telecommunications company Ericsson for managing phone switches. Other topics include Erlang's minimal set of concurrency primitives, its natural fit in distributed Internet server applications, and its use in graphical user interfaces and ordinary batch applications.
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