A prismoid framework for languages with resources

Inspired by the Multiplicative Exponential fragment of Linear Logic, we define a framework called the prismoid of resources where each vertex is a language which refines the λ-calculus by using a different choice to make explicit or implicit (meta-level) the definition of the contraction, weakening, and substitution operations. For all the calculi in the prismoid we show simulation of β-reduction, confluence, preservation of β-strong normalisation and strong normalisation for typed terms. Full composition also holds for all the calculi of the prismoid handling explicit substitutions. The whole development of the prismoid is done by making the set of resources a parameter of the formalism, so that all the properties for each vertex are obtained as a particular case of the general abstract proofs.     

The digital economy: Challenges for Central European Industry

The trajectory of beneficial use of information and communication technologies (ICT) in Hungary, Poland, Lithuania and Ukraine is analysed, especially in industry. With respect to telecom access, availability, affordability and uptake indicators, the four countries are generally behind EU cohesion countries. Between the four countries, there are huge differences in development of information society services. In industry, the use of information technologies usually has not attained the phase in which they are most rewarding. Among the most important barriers to a beneficial use of computer networking in industry are the attitude of management, lack of financial resources and a lack of facilitative environment for enterprises. ICT usage is rarely part of a long-term development stratery of the firm.     

The European Declarative System, database, and languages

The EP2025 EDS project, which is developing a highly parallel information server that supports established high-value interfaces, is discussed. The motivation for the project, the architecture of the system, and the design and application of its database and language subsystems are described. The Elipsys logic programming language, its advanced applications, EDS Lisp, and the Metal machine translation system are examined     

A hybrid Arabic POS tagging for simple and compound morphosyntactic tags

The objective of this work is to develop a POS tagger for the Arabic language. This analyzer uses a very rich tag set that gives syntactic information about proclitic attached to words. This study employs a probabilistic model and a morphological analyzer to identify the right tag in the context. Most published research on probabilistic analysis uses only a training corpus to search the probable tags for each words, and this sometimes affects their performances. In this paper, we propose a method that takes into account the tags that are not included in the training data. These tags are proposed by the Alkhalil_Morpho_Sys analyzer (Bebah et al. 2011). We show that this consideration increases significantly the accuracy of the morphosyntactic analysis. In addition, the adopted tag set is very rich and it contains the compound tags that allow analyze the proclitics attached to words.     

语音自动断句及外语视听教学资源的同步整合

外语教学资源开发水平的高低直接影响到外语教学的效率和效果。对目前外语视听教学资源开发中存在的问题进行了分析;对语音自动断句技术及其在外语视听教学资源开发中的应用进行了研究和探讨;结合作者研发的FLAVS(V3.2)系统,给出了实现语音断句的基本思路以及视听资源的同步整合方法。     

Weakly context-sensitive languages as model for programming languages

Summary An abstract family of formal languages containing context-free languages and properly contained in (deterministic) context-sensitive languages is introduced. This family is comprehensive enough to contain e.g. Algol 60 without admitting too complex recursive constructions possible in the frame of general context-sensitive languages.This family is essentially a family of property-languages, whereby the considered properties are restricted to properties which are constructively definable from a finite number of context-free sets.     

Query languages for sequence databases: termination and complexity

This paper develops a query language for sequence databases, such as genome databases and text databases. Unlike relational data, queries over sequential data can easily produce infinite answer sets since the universe of sequences is infinite, even for a finite alphabet. The challenge is to develop query languages that are both highly expressive and finite. This paper develops such a language as a subset of a logic for string databases called Sequence Datalog. The main idea is to use safe recursion to control and limit unsafe recursion. The main results are the definition of a finite form of recursion, called domain-bounded recursion, and a characterization of its complexity and expressive power. Although finite, the resulting class of programs is highly expressive since its data complexity is complete for the elementary functions     

SafeGPU: Contract- and library-based GPGPU for object-oriented languages

Using GPUs as general-purpose processors has revolutionized parallel computing by providing, for a large and growing set of algorithms, massive data-parallelization on desktop machines. An obstacle to their widespread adoption, however, is the difficulty of programming them and the low-level control of the hardware required to achieve good performance. This paper proposes a programming approach, SafeGPU, that aims to make GPU data-parallel operations accessible through high-level libraries for object-oriented languages, while maintaining the performance benefits of lower-level code. The approach provides data-parallel operations for collections that can be chained and combined to express compound computations, with data synchronization and device management all handled automatically. It also integrates the design-by-contract methodology, which increases confidence in functional program correctness by embedding executable specifications into the program text. We present a prototype of SafeGPU for Eiffel, and show that it leads to modular and concise code that is accessible for GPGPU non-experts, while still providing performance comparable with that of hand-written CUDA code. We also describe our first steps towards porting it to C#, highlighting some challenges, solutions, and insights for implementing the approach in different managed languages. Finally, we show that runtime contract-checking becomes feasible in SafeGPU, as the contracts can be executed on the GPU.     

Anti-patterns for rule-based languages

Negation is intrinsic to human thinking and most of the time when searching for something, we base our patterns on both positive and negative conditions. This should be naturally reflected in software that provide pattern-based searches. We would like for example to specify that we search for white cars that are not station wagons, or that we search for a list of objects that does not contain two identical elements.     

Control structures for data-parallel SIMD languages: semantics and implementation

We define a simple language which encapsulates the main concepts of SIMD data-parallel programming, and we give its operational semantics. This language includes a unique data-parallel control structure called multitype conditioning and escape. We show that it suffices to express all data-parallel extensions of usual scalar control structures of C, as found in C^*, MPL, POMPC, etc. Moreover, we give a formal correctness proof for two different implementations of this new statement, respectively by a single context stack, and by a set of counters. Thus, this simple language appears as an interesting basis to study data-parallel SIMD programming methodology.     

Regular patterns, regular languages and context-free languages

In this paper we consider two questions. First we consider whether every pattern language which is regular can be generated by a regular pattern. We show that this is indeed the case for extended (erasing) pattern languages if alphabet size is at least four. In all other cases, we show that there are patterns generating a regular language which cannot be generated by a regular pattern. Next we consider whether there are pattern languages which are context-free but not regular. We show that, for alphabet size 2 and 3, there are both erasing and non-erasing pattern languages which are context-free but not regular. On the other hand, for alphabet size at least 4, every erasing pattern language which is context-free is also regular. It is open at present whether there exist non-erasing pattern languages which are context-free but not regular for alphabet size at least 4.     

The teaching size: computable teachers and learners for universal languages

Machine Learning - The theoretical hardness of machine teaching has usually been analyzed for a range of concept languages under several variants of the teaching dimension: the minimum number of...     

Model-based software configuration: patterns and languages

The common presupposition of enterprise systems (ES) is that they lead to significant efficiency gains. However, this is only the case for well-implemented ES that are well-aligned with the organisation. The list of ES implementation failures is significant which is partly attributable to the insufficiently addressed fundamental problem of adapting an ES efficiently. As long as it is not intuitively possible to configure an ES, this problem will prevail because organisations have a non-generic character. A solution to this problem consists in re-thinking current practices of ES provision. This paper proposes a new approach based on configurable process models, which reflect ES functionalities. We provide in this paper a taxonomy of situations that can occur from a business perspective during process model configuration. This taxonomy is represented via so-called semantic configuration patterns. In the next step, we discuss so-called syntactic configuration patterns. This second type of configuration patterns implements the semantic configuration patterns for specific modelling techniques. We chose two popular process modelling languages in order to illustrate our approach.