Solving Integer Constraint in Reuse Based Requirements Engineering

International audienceProduct Lines (PL) have proved an effective approach to reuse-based systems development. Several modelling languages were proposed so far to specify PL. Although they can be very different, these languages show two common features: they emphasize (a) variability, and (b) the specification of constraints to define acceptable configurations. It is now widely acknowledged that configuring a product can be considered as a constraint satisfaction problem. It is thus natural to consider constraint programming as a first choice candidate to specify constraints on PL. For instance, the different constraints that can be specified using the FODA language can easily be expressed using boolean constraints, which enables automated calculation and configuration using a SAT solver. But constraint programming proposes other domains than the boolean domain: for instance integers, real, or sets. The integer domain was, for instance, proposed by Benavides to specify constraints on feature attributes. This paper proposes to further explore the use of integer constraint programming to specify PL constraints. The approach was implemented in a prototype tool. Its use in a real case showed that constraint programming encompasses different PL modeling languages (such as FORE, OVM, or else), and allows to specify complex constraints that are difficult to specify with these languages

Constraints: the Heart of Domain and Application Engineering in the Product Lines Engineering Strategy

International audienceDrawing from an analogy between features based Product Line (PL) models and Constraint Programming (CP), this paper explores the use of CP in the Domain Engineering and Application Engineering activities that are put in motion in a Product Line Engineering strategy. The start idea is simple: both CP and PL engineering deal with variables, and constraints that these variables must satisfy. Therefore, specifying a PL as a constraint program instead of a feature model, or another kind of PL formalism, carries out two important qualities of CP: expressiveness and direct automation. On the one hand, variables in CP can take values over boolean, integer, real or even complex domains (i.e., lists, arrays and trees) and not only boolean values as in most PL languages such as the Feature-Oriented Domain Analysis (FODA). Specifying boolean, arithmetic, symbolic and reified constraint, provides a power of expression that spans beyond that provided by the boolean dependencies in FODA models. On the other hand, PL models expressed as constraint programs can directly be executed and analyzed by off-the-shelf solvers. Starting with a working example, this paper explores the issues of (a) how to specify a PL model using CP, including in the presence of multi-model representation, (b) how to verify PL specifications, (c) how to specify configuration requirements and (d) how to support the product configuration activity. Tests performed on a benchmark of 50 PL models show that the approach is efficient and scales up easily to very large and complex PL specification

Educating Students Through Understanding the Pathology of Geotechnical Projects

Three projects of end of studies which are related to soil mechanics pathology case histories were undertaken by students at civil engineering department of National Engineering School of Tunis. The two first projects dealt with Joumine and Sidi Saâd earth dams cases. For Joumine dam, concrete slabs of the spillway have been affected by serious disorders. The first disorder is related to the swelling nature of soil foundation of concrete slabs. The second disorder is attributed to high excess pore pressure responsible of slabs up risings. As solution the jet grouting technique was designed to eliminate high pore pressure in the soil foundation of slabs. For Sidi Saâd dam disorders were attributed to high active soil pressures exerted on retaining walls of the spillway. As solution anchored cables were adopted to improve the stability of concrete walls. The third project dealt with four engineering structures crossing Tunis La Goulette express route. All approach slabs were affected by differential settlements due to the existence of highly compressible thick soft clay layers. As solution three soil improvement techniques (rigid inclusions, stone columns prefabricated vertical drains) were compared to stop non admissible consolidation settlements. For each case history, the methodology to diagnose causes of disorders is first presented, second, the utilized approaches, especially those involving finite element codes usage, are highlighted, finally proposal of remedies to re establish suitable exploitation of projects are exposed. This paper well illustrates the great importance for under graduated students, when preparing their works of end of projects, to more understand fundamentals in soil mechanics in parallel with treating serious problems of pathology of case histories

Deriving Product Line Requirements: the RED-PL Guidance Approach

Product lines (PL) modeling have proven to be an effective approach to reuse in software development.Several variability approaches were developed to plan requirements reuse, but only little of them actuallyaddress the issue of deriving product requirements.This paper presents a method, RED-PL that intends to support requirements derivation. The originality ofthe proposed approach is that (i) it is user-oriented, (ii) it guides product requirements elicitation andderivation as a decision making activity, and (iii) it provides systematic and interactive guidance assistinganalysts in taking decisions about requirements. The RED-PL methodological process was validatedin an industrial setting by considering the requirement engineering phase of a product line of blood analyzers

Étude et amélioration du systèmes de notation Elo pour les compétitions sportives.

La conception d’un système de notation et de prédiction efficace pour les sports compétitifs attire de plus en plus d’attention. Une des approches consiste à inférer les forces des équipes à partir des résultats historiques des rencontres. Ceci est l’un des problèmes fondamentaux dans l’analyse sportive. Dans les années cinquante, Arpad Elo a proposé un algorithme simple pour la notation des joueurs d’échecs, qui est depuis l’algorithme de notation le plus populaire. Dans ce travail, nous expliquons le modèle mathématique derrière l’algorithme Elo, et en particulier, nous expliquons la supposition implicite, mais non mentionnée, du modèle avec égalité. De plus, nous proposons une extension du modèle, le rendant ainsi plus flexible, capable de prendre en considération d’autres suppositions plus réalistes. Ceci nous donne le nouvel algorithme, que nous appelons κ-Elo, qui garde la simplicité de l’algorithme Elo tout en ayant la possibilité de s’ajuster à la fréquence des égalités. Nous présentons une discussion sur l’importance du choix approprié des paramètres ainsi que des exemples illustrateurs basés sur les résultats de la Première Ligue Anglaise de football et de la Ligue Nationale de Hockey. The design of an efficient rating and prediction system for competitive sports attracts a lot of attention. One of the approaches consists of inferring the strength of the teams from historic confrontation results. This is one of the fundamental problems in sports analytics. In the fifties, Arpad Elo proposed a simple, non-trivial rating algorithm for chess players, and since then, it has been the most popular rating algorithm. In this work, we explain the mathematical model behind the Elo algorithm, in particular we explain the implicit assumption yet not spelled out of the draw model. Furthermore, we propose an extension to the model, making it more flexible and thus capable of taking in consideration more realistic assumptions. This yield the new algorithm, we call κ-Elo, which is as simple as the Elo algorithm and it provides the possibility to adjust the draws frequency. We discuss the importance of fine-tuning the parameters and present illustrative examples from the English Premier League football games and from the National Hockey League games

Using Integer Constraint Solving in Reuse Based Requirements Engineering

Product Lines (PL) have proved an effective approach to reuse-based systems development. Several modeling languages were proposed so far to specify PL. Although they can be very different, these languages show two common features: they emphasize (a) variability, and (b) the specification of constraints to define acceptable configurations. It is now widely acknowledged that configuring a product can be considered as a constraint satisfaction problem. It is thus natural to consider constraint programming as a first choice candidate to specify constraints on PL. For instance, the different constraints that can be specified using the FODA language can easily be expressed using boolean constraints, which enables automated calculation and configuration using a SAT solver. But constraint programming proposes other domains than the boolean domain: for instance integers, real, or sets. The integer domain was, for instance, proposed by Benavides to specify constraints on feature attributes. This paper proposes to further explore the use of integer constraint programming to specify PL constraints. The approach was implemented in a prototype tool. Its use in a real case showed that constraint programming encompasses different PL modeling languages (such as FORE, OVM, or else), and allows specifying complex constraints that are difficult to specify with these languages

Survival and inactivation of Salmonella enterica serovar Typhimurium on food contact surfaces during log, stationary and long-term stationary phases

One of the most important transmission routes of foodborne pathogens is through contaminated food contact surfaces. In this study, we investigated the survival and inactivation of Salmonella enterica serovar Typhimurium on frequently used food contact surfaces in household settings, including plastic cutting board (CB), formica laminate (LA), and stainless steel (SS) surfaces. S. Typhimurium at log (6 h), stationary (24 h), or long-term stationary (LTS) (14 days) phases were evaluated. Results showed that, at medium and high microbial loads, LTS phase cells had significantly higher survivor population compared to log and stationary phase cells at 24 h after inoculation (p \u3c 0.05). Disinfection study showed that LTS phase cells were very resilient to sodium hypochlorite when the initial microbial load was high with disinfection efficacy ranging from 26 to 35%. Scanning electron microscopy of these surfaces at 24 h after inoculation with a high microbial load revealed an early biofilm structure

Chemical auxiliaries free dyeing of cationized cotton with 1:2 metal complex dye

Application of 1:2 metal complex dyes on pre-cationized cotton has been studied. This unconventional process avoidsthe use of electrolyte required as exhausting agent in conventional dyeing of cotton fabric. Indeed, when we use a largeamount of salt, the discharged wastewater from dye house creates unavoidable environmental threats. The dyeing has beencarried out at the liquor ratio of 1:40 in a sealed stainless steel dyebath housed on the Ahiba Nuance speed varyingtemperature, contact time and sulphate concentration. Optimal conditions are determined using the experimental designsmethod. The results show the possibility of chemical auxiliaries free dyeing of cotton fabrics with 1:2 metal complex dye at75°C for 15 min by treating them with cationizer prior to dyeing. Adsorption kinetic and isotherm are also studied and theparallel exponential model is shown to fit experimental data with higher average regression coefficients

Survival and inactivation of human norovirus GII.4 Sydney on commonly touched airplane cabin surfaces

Human norovirus (HuNoV) is one of the leading causes of acute gastroenteritis globally. HuNoV outbreaks have been recently reported during air travels. Contaminated surfaces are known as a critical transmission route at various settings. The aim of this study was to provide key information about the survival and the decontamination of HuNoV on three commonly touched airplane cabin surfaces. In this study, we monitored the survival of HuNoV on seat leather, plastic tray table, and seatbelt for 30 days, with and without additional organic load (simulated gastric fluid). The efficacy of two EPA registered anti-norovirus disinfectants were also evaluated. Results showed that HuNoV was detected at high titers (\u3e4 log10 genomic copy number) for up to 30 days when additional organic load was present. Both tested disinfectants were found highly ineffective against HuNoV when the surface was soiled. The study showed that when the organic load was present, HuNoV was highly stable and resistant against disinfectants. Findings from this study indicated that appropriate procedures should be developed by airline companies with the help of public health authorities to decrease passengers’ exposure risk to HuNoV