High-level language virtual machines (HLL VMs) have been playing a key role as a mechanism for implementing programming languages. Languages that run on these execution environments have many advantages over languages that are compiled to native code. These advantages have led HLL VMs to gain broad acceptance in both academy and industry. However, much of the research in this area has been devoted to boosting the performance of these execution environments. Few eorts have attempted to introduce features that automate or facilitate some software engineering activities, including software testing. This research argues that HLL VMs provide a reasonable basis for building an integrated software testing environment. To this end, two software testing features that build on the characteristics of a Java virtual machine (JVM) were devised. The purpose of the rst feature is to automate weak mutation. Augmented with mutation support, the chosen JVM achieved speedups of as much as 95% in comparison to a strong mutation tool. To support the testing of concurrent programs, the second feature is concerned with enabling the deterministic re-execution of Java programs and exploration of new scheduling sequences / Máquinas virtuais de linguagens de programação têm desempenhado um papel importante como mecanismo para a implementação de linguagens de programação. Linguagens voltadas para esses ambientes de execução possuem várias vantagens em relação às linguagens compiladas. Essas vantagens fizeram com que tais ambientes de execução se tornassem amplamente utilizados pela indústria e academia. Entretanto, a maioria dos estudos nessa area têm se dedicado a aprimorar o desempenho desses ambientes de execução e poucos têm enfocado o desenvolvimento de funcionalidades que automatizem ou facilitem a condução de atividades de engenharia de software, incluindo atividades de teste de software. Este trabalho apresenta indícios de que máquinas virtuais de linguagens de programação podem apoiar a criação de ambientes de teste de software integrado. Para tal, duas funcionalidades que tiram proveito das características de uma máquina virtual Java foram desenvolvidas. O propósito da primeira funcionalidade e automatizar a condução de atividades de mutação fraca. Após a implementação de tal funcionalidade na máquina virtual Java selecionada, observou-se um desempenho até 95% melhor em relação a uma ferramenta de mutação forte. Afim de apoiar o teste de programas concorrentes, a segunda funcionalidade permite reexecutá-los de forma determinística além de automatizar a exploração de que novas sequências de escalonamento

Moderne Softwaresysteme sind komplexe Gebilde, welche häufig im Verbund mit anderen technischen und betriebswirtschaftlichen Systemen eingesetzt werden. Für die Hersteller solcher Systeme stellt es oft eine große Herausforderung dar, den oft weit reichenden Anforderungen bezüglich der Anpassbarkeit solcher Systeme gerecht zu werden. Zur Erfüllung dieser Anforderungen hat es sich vielfach bewährt, eine virtuelle Maschine in das betreffende System zu integrieren. <br><br> Die Dissertation richtet sich insbesondere an Personen, die vor der Aufgabe der Integration virtueller Maschinen in bestehende Systeme stehen und zielt darauf ab, solche für die Entscheidung über Integrationsfragen wichtigen Zusammenhänge klar darzustellen. <br><br> Typischerweise treten bei der Integration einer virtuellen Maschine in ein System eine Reihe unterschiedlicher Problemstellungen auf. Da diese Problemstellungen oft eng miteinander verzahnt sind, ist eine isolierte Betrachtung meist nicht sinnvoll. Daher werden die Problemstellungen anhand eines zentral gewählten, sehr umfangreichen Beispiels aus der industriellen Praxis eingeführt. Dieses Beispiel hat die Integration der "Java Virtual Machine" in den SAP R/3 Application Server zum Gegenstand. Im Anschluss an dieses Praxisbeispiel wird die Diskussion der Integrationsproblematik unter Bezug auf eine Auswahl weiterer, in der Literatur beschriebener Integrationsbeispiele vertieft. <br><br> Das Hauptproblem bei der Behandlung der Integrationsproblematik bestand darin, dass die vorgefundenen Beschreibungen, der als Beispiel herangezogenen Systeme, nur bedingt als Basis für die Auseinandersetzung mit der Integrationsproblematik geeignet waren. Zur Schaffung einer verwertbaren Diskussionsgrundlage war es daher erforderlich, eine homogene, durchgängige Modellierung dieser Systeme vorzunehmen. Die Modellierung der Systeme erfolgte dabei unter Verwendung der "Fundamental Modeling Concepts (FMC)". Die erstellten Modelle sowie die auf Basis dieser Modelle durchgeführte Gegenüberstellung der unterschiedlichen Ansätze zur LÖsung typischer Integrationsprobleme bilden den Hauptbeitrag der Dissertation. <br><br> Im Zusammenhang mit der Integration virtueller Maschinen in bestehende Systeme besteht häufig der Bedarf, zeitgleich mehrere "Programme" durch die integrierte virtuelle Maschine ausführen zu lassen. Angesichts der Konstruktionsmerkmale vieler heute verbreiteter virtueller Maschinen stellt die Realisierung eines "betriebsmittelschonenden Mehrprogrammbetriebs" eine große Herausforderung dar. Die Darstellung des Spektrums an Maßnahmen zur Realisierung eines "betriebsmittelschonenden Mehrprogrammbetriebs" bildet einen zweiten wesentlichen Beitrag der Dissertation. / Modern software systems are complex entities which are frequently linked to other technical and economic systems. For the manufacturers of such systems it often represents a big challenge to fulfill the demanding requirements concerning the adaptability of such systems. One possible way to meet the demands is to integrate a virtual machine into the system concerned. <br><br> This thesis is primarily intended to be used by persons who intend to integrate a virtual machine into an existing system. The primary goal is to pinpoint those dependencies which are important for decisions about integration questions. <br><br> The integration of a virtual machine into an existing system is typically accompanied by many different problems. Since these problems are often closely interconnected, it often makes no sense to treat them individually. Therefore, the problems are introduced along with an adequately chosen, complex real life example. This example deals with the integration of the "Java Virtual Machine" into the "SAP R/3" application server. Following this practical example, the discussion of integration problems is deepened by presenting an assortment of additional examples taken from the literature. <br><br> The main problem encountered during the treatment of the integration process was caused by inadequate and incomparable descriptions of the samples used. The existing descriptions were therefore unsuitable as a basis of discussion for the integration topic. For a useful discussion, it was necessary to prepare a uniform and sound modeling of these systems. This was done by adopting the "Fundamental Modeling Concepts (FMC)" technique. The created models as well as the comparison of the different approaches that can be used to solve typical integration problems form the main contribution of the thesis. <br><br> The integration of virtual machines into existing systems is frequently accompanied by the requirement to have the integrated virtual machine process several "programs" simultaneously. In view of the design features of many common virtual machines, the realization of a virtual machine integration that allows the integrated virtual machine to be operated in "multiprogram" mode is still challenging. The most challenging task in this context is the problem of keeping the resource usage of the system at a tolerable level. A comparison of measures that can be taken to reduce the resource usage of an integrated virtual machine that can be operated in "multiprogram" mode forms a second essential contribution of the thesis.

High-level language virtual machines (HLL VMs) have been playing a key role as a mechanism for implementing programming languages. Languages that run on these execution environments have many advantages over languages that are compiled to native code. These advantages have led HLL VMs to gain broad acceptance in both academy and industry. However, much of the research in this area has been devoted to boosting the performance of these execution environments. Few eorts have attempted to introduce features that automate or facilitate some software engineering activities, including software testing. This research argues that HLL VMs provide a reasonable basis for building an integrated software testing environment. To this end, two software testing features that build on the characteristics of a Java virtual machine (JVM) were devised. The purpose of the rst feature is to automate weak mutation. Augmented with mutation support, the chosen JVM achieved speedups of as much as 95% in comparison to a strong mutation tool. To support the testing of concurrent programs, the second feature is concerned with enabling the deterministic re-execution of Java programs and exploration of new scheduling sequences / Máquinas virtuais de linguagens de programação têm desempenhado um papel importante como mecanismo para a implementação de linguagens de programação. Linguagens voltadas para esses ambientes de execução possuem várias vantagens em relação às linguagens compiladas. Essas vantagens fizeram com que tais ambientes de execução se tornassem amplamente utilizados pela indústria e academia. Entretanto, a maioria dos estudos nessa area têm se dedicado a aprimorar o desempenho desses ambientes de execução e poucos têm enfocado o desenvolvimento de funcionalidades que automatizem ou facilitem a condução de atividades de engenharia de software, incluindo atividades de teste de software. Este trabalho apresenta indícios de que máquinas virtuais de linguagens de programação podem apoiar a criação de ambientes de teste de software integrado. Para tal, duas funcionalidades que tiram proveito das características de uma máquina virtual Java foram desenvolvidas. O propósito da primeira funcionalidade e automatizar a condução de atividades de mutação fraca. Após a implementação de tal funcionalidade na máquina virtual Java selecionada, observou-se um desempenho até 95% melhor em relação a uma ferramenta de mutação forte. Afim de apoiar o teste de programas concorrentes, a segunda funcionalidade permite reexecutá-los de forma determinística além de automatizar a exploração de que novas sequências de escalonamento

Background. The awareness of cyber attacks in businesses is increasing with the rising number of cyber incidents for businesses. With nearly 350 000 new malware detected per day, there is a big incentive to allocate resources to company infrastructure to mitigate malware. These solutions require scalability not to become bottlenecks and expensive. Therefore, to combat malware, automated solutions have been developed. The automated solutions comprises isolated virtual environments (sandbox), automated analysis, and reports. As a response from malware developers, malware has evolved to become aware of its environment, which has led to an arms race between malware developers and analysts. Objectives. In this thesis, we study how malware can identify sandbox environments and attempt to find appropriate values for masking system information (features). Methods. First, we research previous techniques to identify sandbox environments and consult with Windows environment experts from Truesec. We found 179 features to examine. Then, we gather a dataset of 2448 non-sandbox samples and 77 sandbox samples with a probing method. We use the statistical test Mann-Whitney U-test to identify features that differ between the dataset's groups. We conduct masking on a dataset level and evaluate it with a method similar to k-fold cross-validation using a random forest classifier. Furthermore, we analyze each feature's ability to detect sandboxes with the feature importance calculated by the Mean Decrease in Impurity (MDI). Results. We found 156 out of 179 features that reveal sandbox environments. Which seven out of those features could independently expose sandboxes, i.e., it was possible to classify all sandboxes and non-sandboxes with only one of them. The masking evaluation indicates that our proposed methods are effective at masking the sandboxes. The results of the feature importance showed that Windows Management Instrumentation (WMI) is an ideal source of information when it comes to exposing sandbox environments. Conclusions. Based on the result, we conclude that various values can expose a sandbox. Furthermore, we conclude that our method to find masking values is adequate and the proposed masking methods successfully masks sandbox samples. Lastly, we conclude that there needs to be a change of focus from evasion techniques to masking implementations in the research field. / Bakgrund. Medvetenheten om cyberattacker i företag ökar med det ökande antalet cyberincidenter mot företag. Med nästan 350 000 nya skadliga program som upptäcks per dag, finns det ett stort incitament att allokera resurser till företagets infrastruktur för att motarbeta denna typ av attack. Dessa lösningar kräver skalbarhet för att inte bli flaskhalsar och dyra. Därför har automatiserade lösningar utvecklats för att bekämpa skadlig programvara. De automatiserade lösningarna omfattar isolerade virtuella miljöer (sandlådor), automatiserad analys och rapporter. Som ett svar från utvecklare av skadlig programvara har skadlig programvara utvecklats till att bli medveten om sin miljö, vilket har lett till en kapprustning mellan utvecklare av skadlig programvara och analytiker. Syfte. I den här artikeln studerar vi hur skadlig programvara kan identifiera sandlådemiljöer och försöka hitta lämpliga värden för att maskera systeminformation (parametrar). Metod. Först undersöker vi tidigare tekniker för att identifiera sandlådemiljöer och rådgör med Windows-miljöexperter från Truesec. Vi hittade 179 parametrar att undersöka. Sedan samlar vi en datauppsättning med 2448 icke-sandlådeprover och 77 sandlådeprover med en sonderingsmetod. Vi använder det statistiska testet Mann-Whitney U-test för att identifiera parametrar som skiljer sig åt mellan datamängdens grupper. Vi utför maskering på datauppsättningsnivå och utvärderar den med en metod som liknar k-faldig korsvalidering med hjälp av en random forest klassificerare. Vidare analyserar vi hur viktig varje parameter är för klassificeraren för att utvärdera parametrarnas förmåga att avslöja sandlådor. Resultat. Vi hittade 156 av 179 parametrar som avslöjar sandlådemiljöer. Vilka sju av dessa parametrar kunde oberoende avslöja sandlådor, det vill säga det var möjligt att klassificera alla sandlådor och icke-sandlådor med endast en av dem. Maskeringsutvärderingen indikerar att våra föreslagna metoder är effektiva för att maskera sandlådorna. Resultaten av viktigheten för parametrarna visade att Windows Management Instrumentation (WMI) är en ideal informationskälla när det gäller att exponera sandlådemiljöer. Slutsatser. Baserat på resultatet drar vi slutsatsen att olika värden kan exponera en sandlåda. Dessutom drar vi slutsatsen att vår metod för att hitta maskeringsvärden är adekvat och de föreslagna maskeringsmetoderna maskerar framgångsrikt sandlådeprover. Slutligen drar vi slutsatsen att det måste ske en förändring av fokus från undanflyktstekniker till maskeringsimplementeringar inom forskningsfältet.

L’objectif de cette thèse est de présenter de nouveaux algorithmes de répartition des ressources sous la forme de machines virtuelles (VMs) et fonction de réseau virtuel (VNFs) dans les Clouds et réseaux de diffusion de contenu (CDNs). La thèse comprend deux principales parties: la première se concentre sur la rentabilité des Clouds distribués, et développe ensuite les raisons d’optimiser les coûts ainsi que les émissions de carbone. Cette partie comprend quatre contributions. La première contribution est une étude de l’état de l’art sur la répartition des coûts et des émissions de carbone dans les environnements de clouds distribués. La deuxième contribution propose une méthode d’allocation des ressources, appelée NACER, pour les clouds distribués. La troisième contribution présente une méthode de placement VM efficace en termes de coûts et de carbone (appelée CACEV) pour les clouds distribués verts. Pour obtenir une meilleure performance, la quatrième contribution propose une méthode dynamique de placement VM (D-CACEV) pour les clouds distribués. La deuxième partie propose des algorithmes de placement de VNFs dans les Clouds et réseaux de CDNs pour optimiser les coûts. Cette partie comprend cinq contributions. Une étude de l’état de l’art sur les solutions proposées est le but de la première contribition. La deuxième contribution propose une méthode d’allocation des ressources, appelée CCVP, pour le provisionnement de service réseau dans les clouds et réseaux de ISP. La troisième contribution implémente le résultat de l’algorithme CCVP dans une plateforme réelle. La quatrième contribution considère l’effet de la permutation de VNFs dans les chaîne de services et la cinquième contribution explique le placement de VNFs pour les services à valeur ajoutée dans les CDNs / High energy costs and carbon emissions are two significant problems in distributed computing domain, such as distributed clouds and Content Delivery Networks (CDNs). Resource allocation methods (e.g., in form of Virtual Machine (VM) or Virtual Network Function (VNF) placement algorithms) have a direct effect on cost, carbon emission and Quality of Service (QoS). This thesis includes three related parts. First, it targets the problem of resource allocation (i.e., in the form of network aware VM placement algorithms) for distributed clouds and proposes cost and carbon emission efficient resource allocation algorithms for green distributed clouds. Due to the similarity of the network-aware VM placement problem in distributed clouds with a VNF placement problem, the second part of the thesis, getting experience from the first part, proposes a new cost efficient resource allocation algorithm (i.e., VNF placement) for network service provision in data centers and Internet Service Provider (ISP) network. Finally, the last part of the thesis presents new cost efficient resource allocation algorithms (i.e., VNF placement) for value-added service provisioning in NFV-based CDNs

I denna uppsats genomför vi en kvalitativ granskning av bilder och text i artiklar från VM i längdskidåkning i Falun, 2015. Tidningarna som är del av undersökningen är Aftonbladet och Dagens Nyheter. Syftet är att undersöka representationen av kön i tidningarna och utröna vilka eventuella mönster och avvikelser från mönster som går att identifiera i framställningen av skidåkarna. Vid granskning av bilder utgår vi ifrån Helena Tolvheds mall för bildanalys som fokuserar på bildkomposition och gestaltning av kroppar. Vid granskning av text försöker vi identifiera mönster utifrån begreppen trivialisering, infantilisering och ambivalens. Resultaten av studien visar att kvinnliga längdskidåkare i större utsträckning trivialiseras och infantiliseras genom skribenternas språkbruk. De kvinnliga längdskidåkarna framställs också mer frekvent på ett sätt som ger intryck av att vara arrangerat i bild. Vår studie visar således att det råder en något skev nyhetsbevakning i framställningen av idrottsmän och idrottskvinnor i tidningarna, vilket också flera tidigare studier kommit fram till. Däremot verkar skillnaderna vara mindre påtagliga än i studier där tidigare perioder i historien legat i fokus, likt i Helena Tolvheds studie. Det bör dock inte förringa att skillnader fortfarande förekommer i framställningen av idrottsmän och idrottskvinnor.

The research reported in this thesis is set within the context of Supply Chain Management within BAE SYSTEMS Naval Business. It explores issues and solutions concerning the optimisation of performance within an operating and business environment experiencing both internal and external pressures to adapt and manage change. This thesis commences with a review of the pertinent literature, identifying six gaps for the writer to address. This attracted a comparative study with two other service orientated industries. The comparison identified similarities and solution methodologies that would inform how best to approach the supply chain factors impacting upon the Naval Defence Industry. Utilising both qualitative and quantitative techniques, the research then progressed to examine the peculiarities of the company's supply chain. Through triangulation, the thesis generated conclusions both from a research and management perspective that were impacting the business. The main focus of this thesis, and thus its contribution to knowledge through addressing the six gaps, is based on how culture, collaboration and change are managed within complex supply chain environments. Through this research, the writer has derived theoretical models and approaches on how one may best address and manage performance driven supply chain initiatives within both the naval defence business and similarly complex service orientated industries.

A Level I code format is proposed for the buckling design of ring-stiffened cylindrical shells under external pressure. Depth independent partial safety factors to be applied to the resistance (collapse pressures), are proposed for the four relevant collapse modes (Interframe Shell Collapse, Frame Yield, Plate Yield and Frame Tripping), covering design and fabrication factors. A partial safety factor to be applied to the load (external pressure), and varying with the design pressure and the maximum expected overdiving, is proposed to cover operational factors. For deep diving vessels or in cases in which the risk of overdiving is not relevant, it is proposed that the overall safety factors used in design may be smaller than those presently recommended. In order to obtain such partial safety factors, different aspects of strength modelling and Structural Reliability had to be addressed. On the strength modelling side, the work was focused on the frame collapse modes. Seventy two experimental results were compiled, corresponding to machined models failing by elastic General Instability. Finite Element (FE) meshes were validated in view of mesh studies and experimental results and further used in parametric studies. The effect of boundary conditions on the elastic General Instability pressure Pn was investigated in view of both experiments and results of the FE models. Statistical properties were obtained for the model uncertainty associated with Pn. Thirty five experimental results were compiled corresponding to welded models failing by General Instability. FE models were validated in view of the most relevant of these experiments as well as in view of other numerical results found in the literature.

Following extensive development over the past two decades, techniques of inverse simulation have led to a range of successful applications, mainly in the fields of helicopter flight mechanics, aircraft handling qualities and associated issues in terms of model validation. However, the available methods still have some well-known limitations. The traditional methods based on the Newton-Raphson algorithm suffer from numerical problems such as high-frequency oscillations and can have limitations in their applicability due to problems of input-output redundancy. The existing approaches may also show a phenomenon which has been termed “constraint oscillations” which leads to low-frequency oscillatory behaviour in the inverse solutions. Moreover, the need for derivative information may limit their applicability for situations involving manoeuvre discontinuities, model discontinuities or input constraints. Two new methods are developed to overcome these issues. The first one, based on sensitivity-analysis theory, allows the Jacobian matrix to be calculated by solving a sensitivity equation and also overcomes problems of input-output redundancy. In addition, it can improve the accuracy of results compared with conventional methods and can deal with the problem of high-frequency oscillations to some extent. The second one, based on a constrained Nelder-Mead search-based optimisation algorithm, is completely derivative-free algorithm for inverse simulation. This approach eliminates problems which make traditional inverse simulation techniques difficult to apply in control applications involving discontinuous issues such as actuator amplitude or rate limits. This thesis also offers new insight into the relationship between mathematically based techniques of model inversion and the inverse simulation approach. The similarities and shortcomings of both these methodologies are explored. The findings point to the possibility that inverse simulation can be used successfully within the control system design process for feedforward controllers for model-based output-tracking control system structures. This avoids the more complicated and relatively tedious techniques of model inversion which have been used in the past for feedforward controller design. The methods of inverse simulation presented in this thesis have been applied to a number of problems which are concerned mainly with helicopter and ship control problems and include cases involving systems having nonminimum-phase characteristics. The analysis of results for these practical applications shows that the approaches developed and presented in this thesis are of practical importance. It is believed that these developments form a useful step in moving inverse simulation methods from the status of an academic research topic to a practical and robust set of tools for engineering system design.

Adhesive-bonded applications are widely used in industry, because of significant advantages such as uniform stress distribution, design flexibility and suitability to bond similar and dissimilar structural materials. This study focuses the adhesive-bonded long overlap of steel/carbon fibre reinforced polymer (CFRP) composite double lap shear (DLS) joints. The purpose of the work is to predict and assess the structural failure and behaviour of the DLS joint, including delamination of the composite, and to determine the effects of the design parameters of adherend thickness, overlap length and fabric orientation on the joint’s failure. There are different ways for such a joint to fail, which makes predicting failure very difficult. Another important difference is the failure mode of composites, where the relatively low interlaminar shear or tensile strength of the resin system causes failure of the composite before failure of the adhesive bondline occurs. Both experimental and numerical methods were used for the analysis. The experimental programme includes fabrication, mechanical testing and failure examinations of various joints. The numerical methods are based on 2D models, using strength of materials and cohesive zone modelling (CZM) approaches. In order to model adhesive joints accurately and efficiently, fracture tests were implemented to determine the fracture criteria. Mode-I and mode-II fracture energies were obtained by double cantilever beam (DCB) and end notched flexure (ENF) tests. An inverse method was used to define the cohesive parameters of the bilinear relation, fitting the numerical and experimental load-displacement curves. The DLS model has been created in Abaqus software, and results for each approach have been presented. Critical locations of stress concentrations in the DLS joint were identified, and the CZM successfully predicted the delamination initiation and propagation region observed in the experiment. As a result, it was concluded that the data obtained from the analysis showed good agreement with the experimental results, and in addition to the fibre orientation angles of the CFRP laminate markedly affecting the failure load of joints, the failure mode and stress distributions appeared in adhesive and composite. Furthermore, the study shows that the cohesive elements enable the numerical results to be obtained in shorter simulation times than the strength of materials approach, which should encourage use of CZM to analyse large structural applications.