Estimation de l'impact du changement dans les programmes à objets

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Études empiriques des relations entre les modèles de qualité du logiciel d' ISO 9126 en utilisant le référentiel de données d'ISBSG et la méthode Taguchi

Avec l'évolution du domaine du genie logiciel, la gestion de la qualite du logiciel a évolué : elle s'est orientee non seulement vers la production de logiciels qui s'executent, mais aussi vers la satisfaction des objectifs pour lesquels ces logiciels sont concus. Contrairement au genie industriel, la gestion de la qualite du logiciel ne porte pas sur le traitement des produits physiques (hard) mais des produits logiques (soft), incluant le developpement du produit logiciel. En genie logiciel la gestion de la qualite requiert l'elaboration d'un ensemble de criteres de qualite que le logiciel doit satisfaire et la proposition de mesures pour evaluer cette qualite, tel que presente dans ISO 9126. La serie ISO 9126 comprend une norme intemationale sur la qualite du produit logiciel et trois rapports techniques. La norme ISO 9126-1 definit deux modeles de qualite du produit logiciel. Le premier modele de « qualite inteme » et de « qualite externe » comprend un ensemble de six caracteristiques, subdivisees en un ensemble de 27 souscaracteristiques pour lesquelles des mesures sont proposees dans les rapports techniques ISO TR 9126-2 et 3. Le deuxieme modele de « qualite en utilisation » comprend un ensemble de quatre caracteristiques et des mesures sont proposees dans le rapport technique ISO TR 9126-4 pour evaluer ces caracteristiques. Cette serie ISO (9126 parties 1 a 4) propose des liens entre ces trois modeles de qualite. Cependant, ces liens, bien que definis par un consensus international d'experts ISO, n'ont pas necessairement été démontrés objectivement et empiriquement: ces liens ne devraient donc etre consideres que comme un ensemble theorique interessant, et pour lequel des experimentations rigoureuses sont requises afin d'en demontrer indubitablement la validite. L'experimentation necessite une collecte de donnees pour realiser les experiences et faire ressortir les resultats des experiences. Cependant, en absence d'opportunites d'experimentations en Industrie, il est possible d'utiliser des referentiels de donnees disponibles en genie logiciel : par exemple, le referentiel de donnees industrielles de rinternational Software Benchmarking Standards Group (ISBSG) regroupe un ensemble d'informations sur les différentes phases du cycle de vie du logiciel. L'approche choisie pour ce projet de recherche est de combiner deux disciplines (genie industriel et genie logiciel) a travers I'utilisafion de la methode Taguchi afin de mener les experimentations avec le contenu des documents ISO 9126 et en exploitant le referentiel de donnees d'ISBSG. La methode Taguchi de concepfion de plan d'experiences, developpee par le Dr. Genichi Taguchi, combine des pratiques industrielles et statistiques et offi-e un moyen d'evaluer la qualite. Le but principal de ce projet de recherche est d'explorer la pertinence des relations entre les modeles de qualite d'ISO 9126 dans la production de logiciels de qualite. Afin de demontrer la pertinence ou non des relations entre ces modeles, les objectifs spécifiques de cette recherche sont de demontrer, par des etudes empiriques, si les relations prises pour acquises par ISO 9126 sont supportees par des donnees empiriques. II s'agit des relations entre : 1. La qualite inteme et la qualite externe. 2. La qualite exteme et la qualite en utilisation. 3. La qualite inteme et la qualite en utilisation. Pour realiser ces objectifs, la methodologie suivante a ete suivie : • verifier jusqu'a quel point le questionnaire d'ISBSG tient compte des trois types de qualite definis dans la norme ISO 9126-1. Pour cela, nous avons aligne les differentes parties du questionnaire d'ISBSG par rapport a la qualite interne, la qualite exteme et la qualite en utilisation de la norme ISO 9126-1; • identifier les caracteristiques de qualite inteme, exteme et en utilisation couvertes par le questionnaire d'ISBSG a travers I'idenfificafion des donnees de qualite du questionnaire d'ISBSG et leurs mesures correspondantes dans les rapports techniques ISO TR 9126-2 a 4; • analyser le referentiel de donnees d'ISBSG afin de determiner les donnees de qualite disponibles pour evaluer les trois types de qualite du produit logiciel d'ISO 9126. Nous avons propose des mesures propres a ISBSG a base de ces donnees. Ces mesures seront utiles lors de la conception des plans d'analyses empiriques avec la methode Taguchi; • adapter la methode Taguchi dc conception de plans d'experiences, d'ordre industriel, au contexte d'analyse empirique en genie logiciel, laquelle adaptation a porte sur I'etape de parametres de design de la strategic hors production (offline) du controle de la qualite de Taguchi; • etablir et analyser les resultats des plans d'analyses empiriques permettant de verifier les liens entre les trois types de qualite d'ISO 9126-1 en utilisant la methode Taguchi et en exploitant les donnees de I'extrait du referentiel d'ISBSG mis a notre disposition pour des fins de recherche. Les resultats de ces travaux de cette recherche ont permis la verification des hypothèses des liens de la norme ISO 9126-1 entre les trois types de qualite : la qualite interne affecte la qualite exteme qui affecte, a son tour, la qualite en utilisation du produit logiciel est effectivement justifiee dans cette these. Les resultats de ces travaux de recherche pourront être utiles pour les chercheurs, praticiens et industriels dans le domaine de la qualite du logiciel. Les resultats de cette recherche pourront egalement être utiles pour l'organisation ISBSG et les experts d'ISO 9126 en particulier, et pour la discipline du genie logiciel en general

Novel synthesis of mesoporous hydroxyapatite using carbon nanorods as a hard-template

© 2017 Elsevier Ltd and Techna Group S.r.l. A novel hard-template synthesis approach for the fabrication of mesoporous hydroxyapatite (HAP) is described herein. Carbon nanorods, synthesised using mesoporous silica (SBA-15) and an acidified sucrose solution, are used as a hard template, after which, they are utilised to synthesise mesoporous HAP. Transmission electron microscopy (TEM), X-ray diffraction (XRD) energy-dispersive X-ray spectroscopy (EDX) and nitrogen adsorption/Brunauer-Emmett-Teller (BET), are all employed to characterise the synthesised materials. We demonstrate that this approach allows for the successful fabrication of single phase HAP with surface area 242.20±2.27m2 g-1 and average pore diameter 3.5nm and 18.9nm. This work proposes for the first time a bespoke innovative procedure that employs carbon nanorods as a template for the synthesis of mesoporous HAP via a hard templating protocol

Acaricide resistance status of livestock ticks from East and West Africa and in vivo efficacy of acaricides to control them

Through a collaborative effort across six Sub-Saharan African countries, using recognized international assessment techniques, 23 stocks of three tick species (Rhipicephalus microplus, Rhipicephalus appendiculatus and Amblyomma variegatum) of economic importance for rural small holder farming communities from East and West Africa were collected from cattle, and evaluated in in vitro larval packet tests (LPT). The results demonstrated medium to high resistance to chlorfenvinphos and amitraz across species. Rhipicephalus microplus demonstrated high level alpha-cypermethrin and cypermethrin resistance. Stocks of A. variegatum (West Africa) and R. appendiculatus (Uganda) demonstrated medium level ivermectin resistance. The four least susceptible stocks (East and West African R. microplus, A. variegatum and R. appendiculatus) were taken into in vivo controlled cattle studies where fipronil was found effective against West and East African R. microplus isolates although persistent efficacy failed to reach 90%. Cymiazole and cypermethrin, and ivermectin based acaricides were partially effective against R. microplus without persistent efficacy. Flumethrin spray-on killed A. variegatum within 72 h for up to 10 days posttreatment, however product application was directly to tick attachment sites, which may be impractical under field conditions. A flumethrin pour-on formulation on goats provided persistent efficacy against A. variegatum for up to one-month. Therapeutic control was achieved against R. appendiculatus through weekly spraying cattle with flumethrin, amitraz or combined cymiazole and cypermethrin. A fipronil pour-on product offered four-week residual control against R. appendiculatus (with slow onset of action). Few studies have assessed and directly compared acaricidal activity in vitro and in vivo. There was some discordance between efficacy indicated by LPT and in vivo results. This observation calls for more research into accurate and affordable assessment methods for acaricide resistance. No single active or product was effective against all three tick species, emphasising the need for the development of alternative integrated tick management solutions.The BMGF and a Bill & Melinda Gates Foundation (BMGF) supported project.https://www.elsevier.com/locate/ijpddrhj2024Veterinary Tropical DiseasesSDG-02:Zero HungerSDG-03:Good heatlh and well-bein

Methane emission management in a dual-fuel engine exhaust using Pd and Ni hydroxyapatite catalysts

© 2017 Elsevier Ltd While dual-fuel engines reduce transportation costs and CO 2 emissions by using alternative energy sources e.g. natural gas, the exhaust streams often contain quantities of emissions that exceed limits and therefore require removal. Pd- and Ni-hydroxyapatite (HAP) catalysts were prepared using a soft-templating method and tested in the dry reforming of methane (DRM) in a fixed bed reactor that simulates an exhaust from a diesel-natural gas dual-fuel engine. XRD revealed the characteristic HAP crystal structure of all the prepared materials. The HAP phase was further confirmed by TEM, which also showed the presence of submicron sized particles. The BET surface areas of HAP prepared using a single surfactant was 27.7 m 2  g −1 and increased to 84.9 m 2  g −1 when mixed surfactants were used. Active metals were added to HAP using either incipient wetness impregnation, ion-exchange or solid dispersion. All the catalysts tested were active in DRM with the optimal samples converting over 85% of methane at 650 °C

Power laws govern mitochondrial optimization of inheritable cellular memory and fate decision

Chronic environmental exposure to arsenic in drinking water is a major public health concern affecting the health of more than 130 million people worldwide. In addition to causing cancer and non-cancer diseases, arsenic causes muscle weakness and dysfunction. We found that arsenic targets muscle stem cell mitochondrial functionality to impair muscle maintenance and regeneration. Stem cell behavior was determined by their epigenetic memory. Although mitochondrial remodeling is inescapable for successful differentiation and pluripotency reprogramming and mitochondria-derived outputs shape cellular epigenetic landscape, their role in the regulation of cellular memory is poorly understood. Arsenic is a mitochondrial stressor and epigenetic modifier that alters stem-cell fate determination making it an excellent tool to determine the mitochondrial contribution to regulation of cellular memory and fate decisions. Using a model of myogenic differentiation, we imprinted a memory of arsenite-induced stress into myogenic reserve cells (RC) and monitored the fate of their progeny in arsenic-free medium. Phenotyping of primed RC revealed inherited aberrant mitochondrial dynamics that limited self-renewal capacity and enhanced their proliferation; trapping them in a poised state. Non-Gaussian statistics demonstrated that nuclear protein profiles and morphometrics were distributed as power-laws, indicating the presence of critical self-organization at the cell population level. Using graph theory, we modeled the mitochondria and showed an increased connectivity of the primed RC progeny mitochondrial networks. We identified crucial interplay of H2A.Z acetylation with RNA polymerase II at bivalent chromatin domains that define chromatin state and transcriptional plasticity of the primed RC. Importantly, the intervention by mitochondria-targeted XJB-5-131 fully restored mitochondrial functionality and dynamics, RC cellular phenotypic identity, nuclear morphometrics, and epigenetic regulation that reset RC memory including histone modifications. Collectively, this work demonstrated that poising of chromatin regulation and cellular memory are fundamentally contingent on mitochondrial functionality and dynamics. Furthermore, we provided an innovative conceptual framework whereby cellular memory and cell fate are statistical properties defined at the cell population level by intricate mechanisms integrated at the mitochondrial level and governed by power laws. Significantly, the beneficial effects of XJB-5-131 suggest a window of opportunity for preventing or reverting disease resulting from stem cell dysfunction

Methane conversion to higher alkanes over ruthenium and cobalt loaded Zr3_{3}(PO4_{4})4_{4}

The catalyst Ru-Co/Zr$_3$(PO$_4)_4$ was synthesized by impregnation and was tested in the reaction of oligomerization of methane into higher hydrocarbon. The reaction was carried out using a two-steps procedure consisting of: 
- Methane adsorption. 
- Hydrogenation of the adsorbed entities and formation of higher hydrocarbons. 
The production of these alkanes extends from ethane to pentane and could schematically be described by the following pathways: 
 {\rm CH}_4 \, \hbox{\fontsize{20}{20}\selectfont $\rightleftharpoons$} ({\rm CH}_{\rm x})_{\rm ads} \,+\, (4-{\rm X})/2\,{\rm H}_2 {\rm CH}_{\rm x}, \, {\rm CH}_{\rm y}\hbox{\fontsize{20}{20}\selectfont $\rightleftharpoons$} {\rm C}_{\rm n}{\rm H}_{\rm m} The results showed that addition of cobalt to ruthenium improved the global activity. This promoter effect was attributed to the synergy brought in by cobalt and to the formation of Ru-CO$^{2+ }$species which are more active than ruthenium alone. These species were identified by EDX-STEM and XPS analyses