This study investigated 15 child care centres to find out their responsiveness to the needs of families from non-Anglo backgrounds. Results of this study showed a need to improve service quality in child care to best serve the needs of children from non-Anglo backgrounds. Forty Filipino, 15 Cambodian and 30 Sudanese families were involved in this study.

In future service markets a selection of functionally equal services is omnipresent. The evolving challenge, finding the best-fit service, requires a distinction between the non-functional service characteristics (e.g., response time, price, availability). Service providers commonly capture those quality characteristics in so-called Service Level Agreements (SLAs). However, a service selection based on SLAs is inadequate, because the static SLAs generally do not consider the dynamic service behaviors and quality changes in a service-oriented environment. Furthermore, the profit-oriented service providers tend to embellish their SLAs by flexibly handling their correctness. Within the SOC (Service Oriented Computing) research project of the Karlsruhe University of Applied Sciences and the Linnaeus University of Sweden, a service broker framework for an optimized web service selection is introduced. Instead of relying on the providers’ quality assertions, a distributed knowledge is developed by automatically monitoring and measuring the service quality during each service consumption. The broker aims at optimizing the service selection based on the past real service performances and the defined quality preferences of a unique consumer.This thesis work concerns the design, implementation and evaluation of appropriate machine learning methods with focus on the broker’s best-fit web service selection. Within the time-critical service optimization the performance and scalability of the broker’s machine learning plays an important role. Therefore, high- performance algorithms for predicting the future non-functional service characteristics within a continuous machine learning process were implemented. The introduced so-called foreground-/background-model enables to separate the real-time request for a best-fit service selection from the time-consuming machine learning. The best-fit services for certain consumer call contexts (e.g., call location and time, quality preferences) are continuously pre-determined within the asynchronous background-model. Through this any performance issues within the critical path from the service request up to the best-fit service recommendation are eliminated. For evaluating the implemented best-fit service selection a sophisticated test data scenario with real-world characteristics was created showing services with different volatile performances, cyclic performance behaviors and performance changes in the course of time. Besides the significantly improved performance, the new implementation achieved an overall high selection accuracy. It was possible to determine in 70% of all service optimizations the actual best-fit service and in 94% of all service optimizations the actual two best-fit services.

Seleção de serviços em composições distribuídas considera principalmente a qualidade de serviço que atenda requisitos estabelecidos pelo usuário, como por exemplo, preço. No entanto, problemas relacionados a execução de composições de serviços podem ocorrer quando não se considera aspectos relacionados à rede e ao hardware, que afetam diretamente o desempenho da composição. Esse problema se agrava em composições coreografadas, pois a característica descentralizada requer um maior esforço para que essas informações possam ser consideradas em uma perspectiva global. Dessa forma, apesar da descentralização apresentar vantagens, é necessário que requisitos de qualidade de serviço da composição também sejam considerados em coreografias de serviços web para que a escolha de serviços para desempenhar um papel leve em consideração parâmetros importantes que podem afetar no desempenho da composição. Este trabalho apresenta um mecanismo, implementado sobre o framework OpenKnowledge, para selecionar serviços web em ambientes coreografados considerando primeiramente estimativas de atraso, taxa de perda e por fim considera a utilização de outros parâmetros, como utilização de CPU. Os primeiros experimentos em diferentes cenários de rede confirmaram as vantagens da proposta em relação a um seletor de serviços que ignora aspectos relacionados com a rede. Obteve-se ganhos de 20 a 97% no que diz respeito ao tempo total da execução da coreografia. Em seguida, experimentos inserindo utilização de CPU na escolha dos serviços confirmaram as vantagens de utilização de diferentes parâmetros para seleção de serviços em coreografias. / Selection of services in distributed compositions mainly considers the quality of service that meets requirements set by the user, such as price. However, problems related to the execution of service compositions may occur when aspects related to network and hardware, which directly affect the performance of the composition, are not taken in consideration. This problem is aggravated in choreographed compositions because the decentralized feature requires a greater effort so that this information may be considered in a global perspective. Thus, despite the decentralization advantages, it is necessary that the service quality requirements of the composition may also be considered in the choreography of web services so that the choice of services may play a role that takes into account important parameters, which can affect the performance of the composition. This dissertation presents a mechanism, implemented on the OpenKnowledge framework, to select web services in choreographed environments. First, considering delay estimates, loss rate and finally the use of other parameters, such as CPU utilization. The first experiments on different network scenarios confirmed the proposal advantages in relation to a selection mechanism that bypasses aspects of the network. It was obtained gains from 20% to 97% considering the total time of execution of the choreography. Then, experiments inserting CPU utilization in the choice of services confirmed the advantages of using different parameters for selection of services in choreography.

With the development of 5G technology and edge computing, more and more network application services have been migrated to the cloud network in order to improve the performance, availability and ensure Quality of Service. Edge computing has essentially changed the service deployment model and reduce the latency further for better customer experience, which is realized by deploying network service replicas in geographically distributed edge sites. However, how to discover edge application servers and select a proper instance to serve the edge users becomes an important research topic. This master thesis project addresses the problem by leveraging DNS based service selection mechanism, designing and implementing stable match based service selection algorithms with the aim of minimizing latency between edge users and services and balance the load among edge sites, and integrating the solutions by RESTful APIs. To evaluate the performance of the service selection algorithms, a set of experiments are carried on different simulated topologies with different traffic pattern. The experimental results show that the stable match algorithm and its variants can significantly reduce the average latency by up to 50% compared to traditional approaches, while the enhanced stable match based algorithms are able to have the same load balancing effect with the widely used Round Robin algorithm. / Med utvecklingen av 5G-teknik och edge computing har fler nätverkstjänster migrerats till molnätet för att förbättra prestanda, tillgänglighet och säkerställa servicekvalitet. Edge computing har i huvudsak förändrat tjänster distribution modellen och minskat latensen ytterligare för bättre kundupplevelse, vilket realiseras genom att distribuera nätverkstjänstreplikat på geografiskt distribuerade kantsajter. Hur man upptäcker kantappservrar och väljer en rätt instans för att betjäna kantanvändarna blir dock ett viktigt forskningsämne. Detta projekt löser problemet genom att utnyttja DNS-baserad mekanism för tjänstval, designa och implementera stabila matchbaserade algoritmer för tjänsteval i syfte att minimera latens mellan kantanvändare och tjänster och balansera belastningen mellan kantsajter och integrera lösningarna med RESTful API:er. För att utvärdera prestandan för algoritmerna för val av tjänster utförs en uppsättning experiment på olika simulerade topologier med olika trafikmönster. De experimentella resultaten visar att den stabila matchningsalgoritmen och dess varianter avsevärt kan minska den genomsnittliga latensen med upp till 50% jämfört med traditionella metoder, medan de förbättrade stabila matchbaserade algoritmerna kan ha samma belastningsbalanseringseffekt med den mycket använda Round Robin algoritm.

A brokerless edge service marketplace could play a significant role in enabling an eco- system where a large number of edge providers and Communication Service Providers (CSPs) offer Mobile Edge Infrastructure Services (EISs) to providers of edge-based applications and services. The marketplace would be the bridge between EIS providers and their customers, managing the relations between actors in the mobile edge eco- system. One of the key services of the marketplace is service selection where not only a list of EISs matching the customers’ demands is provided but also enables service selection based on the customers’ requirements to fully automate the process.We firstly consider different selection scenarios and investigate essential parameters for service selection in such a marketplace, including (i) important attributes of EISs such as coverage area, latency, pricing, etc, and (ii) the requirements of edge-based applications such as latency and reliability. We formulate how these application requirements can be fulfilled by choosing the right set of EISs among available services in the marketplace as two different optimization problems considering average latency and cost as separate objectives to minimize. First, we relax the objective function in average delay minimization problem, which is a linear-fractional programming problem. We solve the relaxed version of the problem by Branch and bound (BnB) and Bound and Branch with Priority Queue (BnBPQ) algorithms. Additionally, we relax the objective function in total monetary cost minimization problem which is an integer linear programming problem. We propose Best Fit (BF) and Improved Best Fit (IBF) algorithms to solve the problem. Furthermore, the IBM CPLEX Optimizer [1] is also implemented to solve the two problems. The evaluation shows that the algorithms we implemented can solve the problems with results close to optimal as compared to the results of exhaustive search and shorter run time than exhaustive search. Meanwhile, the CPLEX can solve the problem well, but it’s not scalable for huge problem instances since the problems are NP-complete and not solvable in polynomial time. / En marknadslös marknadsföring på kanten av tjänster kan spela en viktig roll för att möjliggöra ett ekosystem där ett stort antal kantleverantörer och acp CSP erbjuder Mobile acp EIS till leverantörer av kantbaserade applikationer och tjänster. Marknadsplatsen skulle vara bron mellan ac EIS leverantörer och deras kunder och hantera relationerna mellan aktörer i det mobila ekosystemet. En av marknadens viktigaste tjänster är val av tjänster där inte bara en lista över acp EIS som matchar kundernas krav tillhandahålls utan också möjliggör serviceval baserat på kundernas krav för att automatisera processen helt.Vi överväger för det första olika urvalsscenarier och undersöker väsentliga parametrar för val av tjänster på en sådan marknadsplats, inklusive (i) viktiga attribut för acp EIS som täckningsområde, latens, prissättning osv. Och (ii) kraven på kant- baserade applikationer som latens och tillförlitlighet. Vi formulerar hur dessa applikationskrav kan uppfyllas genom att välja rätt uppsättning acp EIS bland tillgängliga tjänster på marknaden som två olika optimeringsproblem med tanke på genomsnittlig latens och kostnad som separata mål för att minimera. Först slappnar vi av objektivfunktionen i ett genomsnittligt förseningsminimeringsproblem, vilket är ett linjärt-fraktionellt programmeringsproblem. Vi löser den avslappnade versionen av problemet med ac BnB och ac BnBPQ algoritmer. Dessutom slappnar vi av objektivfunktionen i totala monetära kostnadsminimeringsproblem som är ett heltal linjärt programmeringsproblem. Vi föreslår ac BF och ac IBF algoritmer för att lösa problemet. Dessutom implementeras IBM CPLEX Optimizer cite cplex för att lösa de två problemen. Utvärderingen visar att algoritmerna vi implementerade kan lösa problemen med resultat som är nära optimala jämfört med resultaten av uttömmande sökning och kortare körtid än uttömmande sökning. Under tiden kan CPLEX lösa problemet väl, men det är inte skalbart för stora problemstillfällen eftersom problemen är NP-kompletta och inte lösbara under polynom tid.

<p>This thesis is concerned with two separate subjects; (i) Defect localization using tree mining and tree matching, and (ii) Quality-of-service-aware service selection; it is divided into these parts accordingly.</p> / <p>This thesis is concerned with two separate subjects; (i) Defect localization using tree mining and tree matching, and (ii) Quality-of-service-aware service selection; it is divided into these parts accordingly.</p> <p>In the first part of this thesis we present a novel technique for defect localization which is able to localize call-graph-affecting defects using tree mining and tree matching techniques. In this approach, given a set of successful executions and a failing execution and by following a series of analyses we generate an extended report of suspicious method calls. The proposed defect localization technique is implemented as a prototype and evaluated using four subject programs of various sizes, developed in Java or C. Our experiments show comparable results to similar defect localization tools, but unlike most of its counterparts, we do not require the availability of multiple failing executions to localize the defects. We believe that this is a major advantage, since it is often the case that we have only a single failing execution to work with. Potential risks of the proposed technique are also investigated.</p> <p>In the second part of this thesis we present an alternative strategy for service selection in service oriented architecture, which provides better quality services for less cost. The proposed Request Replication technique replicates a client’s request over a number of cheap, low quality services to gain the required quality of service. Following this approach, we also present a number of recommendations about how service providers should advertise non-functional properties of their services.</p> / Doctor of Philosophy (PhD)

The aim of this essay is to investigate how the audit profession has changed since the abolition of audit obligation and how the auditors have adapted to the change. Through qualitative interviews with auditors, the auditor's role and duties has been analyzed since the abolition of audit obligation and the reduced demand for auditing. This in order to determine whether the abolition of the audit obligation has resulted in a change in the auditor's offer of services and if this has affected independence. Continuingly, the role of the auditor has been analyzed by the importance of the relationship with the customer as well as the expectation gap that exists. The collected material will be explained by an objective approach. The empirical evidence shows that there is a difference for the auditor's role as well as duties following the abolition of audit obligation where the service offer has been expanded while there is a reduced demand for auditing, which has been replaced by other services.

Avec l'apparition des paradigmes de l'intelligence ambiante et de la robotique ubiquitaire, on assiste à l'émergence de nouveaux systèmes intelligents ambiants visant à créer et gérer des environnements ou écosystèmes intelligents d'une façon intuitive et transparente. Ces environnements sont des espaces intelligents caractérisés notamment par l'ouverture, l'hétérogénéité, l'incertitude et la dynamicité des entités qui les constituent. Ces caractéristiques soulèvent ainsi des défis scientifiques considérables pour la conception et la mise en œuvre d'un système intelligent adéquat. Ces défis sont principalement au nombre de cinq : l'abstraction de la représentation des entités hétérogènes, la gestion des incertitudes, la réactivité aux événements, la sensibilité au contexte et l'auto-adaptation face aux changements imprévisibles qui se produisent dans l'environnement ambiant. L'approche par composition dynamique de services constitue l'une des réponses prometteuses à ces défis. Dans cette thèse, nous proposons un système intelligent capable d'effectuer une composition dynamique de services en tenant compte, d'une part, du contexte d'utilisation et des diverses fonctionnalités offertes par les services disponibles dans un environnement ambiant et d'autre part, des besoins variables exprimés par les utilisateurs. Ce système est construit suivant un modèle multicouche, adaptatif et réactif aux événements. Il repose aussi sur l'emploi d'un modèle de connaissances expressif permettant une ouverture plus large vers les différentes entités de l'environnement ambiant notamment : les dispositifs, les services, les événements, le contexte et les utilisateurs. Ce système intègre également un modèle de découverte et de classification de services afin de localiser et de préparer sémantiquement les services nécessaires à la composition de services. Cette composition est réalisée d'une façon automatique et dynamique en deux phases principales: la phase offline et la phase online. Dans la phase offline, un graphe global reliant tous les services abstraits disponibles est généré automatiquement en se basant sur des règles de décision sur les entrées et les sorties des services. Dans la phase online, des sous-graphes sont extraits automatiquement à partir du graphe global selon les tâches à réaliser qui sont déclenchées par des événements qui surviennent dans l'environnement ambiant. Les sous-graphes ainsi obtenus sont exécutés suivant un modèle de sélection et de monitoring de services pour tenir compte du contexte d'utilisation et garantir une meilleure qualité de service. Les différents modèles proposés ont été mis en œuvre et validés sur la plateforme ubiquitaire d'expérimentation du laboratoire LISSI à partir de plusieurs scénarii d'assistance et de maintien de personnes à domicile / With the appearance of the paradigms of the ambient intelligence and ubiquitaire robotics, we attend the emergence of new ambient intelligent systems to create and manage environments or intelligent ecosystems in a intuitive and transparent way. These environments are intelligent spaces characterized in particular by the opening, the heterogeneousness, the uncertainty and the dynamicité of the entities which establish(constitute) them. These characteristics so lift(raise) considerable scientific challenges for the conception(design) and the implementation of an adequate intelligent system. These challenges are mainly among five: the abstraction of the representation of the heterogeneous entities, the management of the uncertainties, the reactivity in the events, the sensibility in the context and the auto-adaptation

Le but de cette thèse est de dégager un cadre sémantique formel approprié supportant l'interopérabilité dedifférents formalismes déjà utilisés pour décrire et déployer un service Web. En d’autres termes, nouscontribuons au développement d’un formalisme mathématique rigoureux permettant de décrire un service Webcomplexe susceptible de changer pendant l’exécution et de coordonner avec les autres services de façonadaptative. Pour atteindre cet objectif, les étapes de description, de sélection et de composition ont constitué lestrois majeures problématiques étudiées dans cette thèse.Pour ce faire, nous avons proposé dans un premier temps, à travers l’utilisation du cadre sémantique formel K lelangage K-WSDL; un langage de description de services Web doté d’une sémantique opérationnelle en terme derègles de réécriture qui peut être exécutable et analysable sous Maude. Nous avons introduit, dans un secondtemps, l’approche WS-Sim basée sur la théorie des catégories qui évalue l’équivalence comportementale entreservices en représentant chaque service par une catégorie et en établissant des liens formels (foncteur) entre elles.Enfin, nous avons présenté le modèle RMop-ECATNet (Refined Meta Open ECATNet ) : un modèle dédié à laspécification formelle de la composition des services Web et fruit du raffinement du modèle Mop-ECATNetproposé par [LB14]. Nous avons étendu et enrichi ce dernier aux trois niveaux : structurel, comportemental etimplémentation. / The aim of this thesis is to provide a suitable formal semantic framework that supports interoperability ofdifferent formalisms already used to describe and deploy a Web service. In other words, we contribute to thedevelopment of a rigorous mathematical formalism to describe a complex Web service that may change duringexecution and coordinate with other services adaptively. To achieve this goal, the steps of description, selectionand composition constitute the three major issues studied in this thesis.We proposed so, initially, through the use of the K semantic framework the K-WSDL : a Web servicesdescription language endowed with an operational semantics in terms of rewriting rules which can be executedand analyzed in Maude. We introduced, in a second step, WS-Sim, a new approach based on the category theorywhich evaluates the behavioral equivalence between services by representing each service by a category and byestablishing formal links (functor) between them. Finally, we present RMop-ECATNet (Refined Meta OpenECATNet): a formal model for the specification of services composition. product of the refinement of the Mop-ECATNets model, introduced initially by [LB14]. We extended and enriched this model at three distinct levels:at the structural, behavioural level and implementation levels.