A CSP approach for the network of product lifecycle constraints consistency in a collaborative design context

In this paper, we are considering that the design process can be modelled in the form of a constraint satisfaction problem (CSP). CSP modelling or resolution has proved its efficiency within the framework of single-designer design. We propose to extend the functions of CSP to the context of multi-concept design of the same artefact. We define CoCSP as cooperative constraint satisfaction problem including the actors of the design problem. We are presenting the operating principles of an algorithm for the real-time management of design decisions, based on a model described in the form of a CoCSP for the integration of supply-chain constraints. This algorithm enables the number of design decisions rejected at a given moment in design to be kept to a minimum. The algorithm forms the core of a prototype for an unsupervised, generic constraint-based collaborative design system. Our aim is to produce a platform centred on the notion of constraints that will enable a product design problem to be modelled and solved by integrating supply-chain constraints as far upstream as possible.     

Model-driven analysis and synthesis of textual concrete syntax

Meta-modeling is raising more and more interest in the field of language engineering. While this approach is now well understood for defining abstract syntaxes, formally defining textual concrete syntaxes with meta-models is still a challenge. Textual concrete syntaxes are traditionally expressed with rules, conforming to EBNF-like grammars, which can be processed by compiler compilers to generate parsers. Unfortunately, these generated parsers produce concrete syntax trees, leaving a gap with the abstract syntax defined by meta-models, and further ad hoc hand-coding is required. In this paper we propose a new kind of specification for concrete syntaxes, which takes advantage of meta-models to generate fully operational tools (such as parsers or text generators). The principle is to map abstract syntaxes to textual concrete syntaxes via bidirectional mapping-models with support for both model-to-text, and text-to-model transformations.

Tightly Secure Signatures From Lossy Identification Schemes

In this paper, we present three digital signature schemes with tight security reductions in the random oracle model. Our first signature scheme is a particularly efficient version of the short exponent discrete log-based scheme of Girault et al. (J Cryptol 19(4):463–487, 2006). Our scheme has a tight reduction to the decisional short discrete logarithm problem, while still maintaining the non-tight reduction to the computational version of the problem upon which the original scheme of Girault et al. is based. The second signature scheme we construct is a modification of the scheme of Lyubashevsky (Advances in Cryptology—ASIACRYPT 2009, vol 5912 of Lecture Notes in Computer Science, pp 598–616, Tokyo, Japan, December 6–10, 2009. Springer, Berlin, 2009) that is based on the worst-case hardness of the shortest vector problem in ideal lattices. And the third scheme is a very simple signature scheme that is based directly on the hardness of the subset sum problem. We also present a general transformation that converts what we term \(lossy \) identification schemes into signature schemes with tight security reductions. We believe that this greatly simplifies the task of constructing and proving the security of such signature schemes.     

Rainfall-runoff modeling of flash floods in the absence of rainfall forecasts: the case of “Cévenol flash floods”

“Cévenol flash floods” are famous in the field of hydrology, because they are archetypical of flash floods that occur in populated areas, thereby causing heavy damages and casualties. As a consequence, their prediction has become a stimulating challenge to designers of mathematical models, whether physics based or machine learning based. Because current, state-of-the-art hydrological models have difficulty performing forecasts in the absence of rainfall previsions, new approaches are necessary. In the present paper, we show that an appropriate model selection methodology, applied to neural network models, provides reliable two-hour ahead flood forecasts.     

Signed Lp-distance fields

We introduce and study a family of generalized double-layer potentials which are used to build smooth and accurate approximants for the signed distance function. Given a surface, the value of an approximant at a given point is a power mean of distances from the point to the surface points parameterized by the angle they are viewed from the given point. We analyze mathematical properties of the potentials and corresponding approximants. In particular, approximation accuracy estimates are derived. Our theoretical results are supported by numerical experiments which reveal the high practical potential of our approach.     

Applying an object-oriented method to design a VPN bandwidth management system

This paper describes the application of the Fusion method to the design of a bandwidth management system for ATM-based virtual private networks as well as the rationale for selecting that particular general purpose object-oriented method. The system considered allows a vpn customer to dynamically modify the bandwidth allocated to vpn connections. The design process has focused on the software structures and interactions between them required to provide the desired functionality to the customer. Finally the vpn customer, value added service provider and network providers service management system interfaces have been designed and corresponding primitives are given.     

Generating tests from B specifications and dynamic selection criteria

This paper is about generating tests from dynamic selection criteria called test purposes, in addition to structural tests, obtained from static selection criteria. We present a method that re-uses a behavioral model and an abstract test concretization layer developed for structural testing, and relies on additional test purposes. We propose, in the B framework, a process of test generation that uses the symbolic animation mechanisms of Leirios Test Generator (LTG) based on constraint solving, and guided by the test purposes. We build for that a B model that is the synchronized product of a behavioral B abstract model and a test purpose described as a labeled transition system. We prove the correctness of this method, and show some experimental results obtained on the IAS case study. IAS is an industrial smart-card platform dedicated to the operations of Identification, Authentication and electronic Signature. Our experiments show that the tests obtained from test purposes are complementary to the structural tests.     

Exploiting model driven technology: a tale of two startups

This article describes the experiences of two independent start-up companies that were created in the white-heat of the early days of model-based engineering. Each company aimed to revolutionise software development by raising the level of abstraction through modelling. The article describes the context, technical innovations, business experiences, demise and lessons learned by each company.     

Partition coefficients of ionizable compounds in o-nitrophenyl octyl ether/water measured by the potentiometric method

The objective of this study was to investigate the reliability of potentiometric measurements of partition coefficients (log P) in the o-NPOE/water system, o-nitrophenyl octyl ether being an organic solvent widely used for the voltammetric determination of the partition coefficient of ions. Three sets of ionizable model compounds were explored in this study. The results showed that the potentiometric technique gave precise and reliable log P(npoe) values in the explored range of 0.1-4.3.