Recently, companies are adopting Mobile Cloud Computing (MCC) to efficiently deliver enterprise services to users (or consumers) on their personalized devices. MCC is the facilitation of mobile devices (e.g., smartphones, tablets, notebooks, and smart watches) to access virtualized services such as software applications, servers, storage, and network services over the Internet. With the advancement and diversity of the mobile landscape, there has been a growing trend in consumer attitude where a single user owns multiple mobile devices. This paradigm of supporting a single user or consumer to access multiple services from n-devices is referred to as the Ubiquitous Cloud Computing (UCC) or the Personal Cloud Computing. In the UCC era, consumers expect to have application and data consistency across their multiple devices and in real time. However, this expectation can be hindered by the intermittent loss of connectivity in wireless networks, user mobility, and peak load demands. Hence, this dissertation presents an architectural framework called, Cloud Services Brokerage for Mobile Ubiquitous Cloud Computing (CSB-UCC), which ensures soft real-time and reliable services consumption on multiple devices of users. The CSB-UCC acts as an application middleware broker that connects the n-devices of users to the multi-cloud services. The designed system determines the multi-cloud services based on the user's subscriptions and the n-devices are determined through device registration on the broker. The preliminary evaluations of the designed system shows that the following are achieved: 1) high scalability through the adoption of a distributed architecture of the brokerage service, 2) providing soft real-time application synchronization for consistent user experience through an enhanced mobile-to-cloud proximity-based access technique, 3) reliable error recovery from system failure through transactional services re-assignment to active nodes, and 4) transparent audit trail through access-level and context-centric provenance.

La Institución Pública es un organismo encargado de la recaudación en el Perú vinculado al Ministerio de Economía y Finanzas, y tiene como Misión transformarse en la administración tributaria y aduanera más exitosa, moderna y respetada de la región. Para eso desde hace algunos años la institución ha comenzado a lanzar iniciativas de proyectos de software que utilicen cloud computing, para que de esta forma puedan trabajar de manera más eficiente la gestión y compra de infraestructura, así como poder atender la demanda creciente de servicios digitales solicitados por los contribuyentes. La presente tesis analizó la forma de cómo la Institución Pública fue adoptando cloud computing en sus proyectos de software, y como esta adopción puede ser mejorada al contar con un marco de trabajo que le permita tener pautas de cómo lanzar iniciativas que involucren en su desarrollo el uso de cloud como base tecnológica, y como esto debe estar alineada a la estrategia de crecimiento de servicios digitales que la Institución Pública desea ir cubriendo poco a poco para mejora su servicio hacia los contribuyentes. / The Public Organization is an institution in charge of tax collection in Peru, and linked to the Ministry of Economy and Finance, and has as its main mission to become the most successful, modern and respected tax and customs administration in the region. For this reason, for some years ago, the institution has begun to launch software project initiatives that use cloud computing, so that they can work more efficiently in the management and purchase of infrastructure, as well as being able to meet the growing demand for digital services. requested by taxpayers The current thesis analyzed how the Public Organization was adopting cloud computing in its software projects, and how this adoption can be improved, by having a framework that allows it to have guidelines on how to launch initiatives that involve in its development the use of Cloud as a technology base, and how this should be aligned with the digital services growth strategy that the Public Organization wishes to gradually cover to improve its service to taxpayers. / Trabajo de investigación

<p>Data and information have increased exponentially in recent years. The promising era of big data is advancing many new practices. One of the emerging big data applications is healthcare. Large quantities of data with varying complexities have been leading to a great need in smart and secure big data systems. </p> <p>Mobile edge, more specifically the smart phone, is a natural source of big data and is ubiquitous in our daily lives. Smartphones offer a variety of sensors, which make them a very valuable source of data that can be used for analysis. Since this data is coming directly from personal phones, that means the generated data is sensitive and must be handled in a smart and secure way. In addition to generating data, it is also important to interact with the big data. Therefore, it is critical to create edge systems that enable users to access their data and ensure that these applications are smart and secure. As the first major contribution of this thesis, we have implemented a mobile edge system, called s²Edge. This edge system leverages Amazon Web Service (AWS) security features and is backed by an AWS cloud system. The implemented mobile application securely logs in, signs up, and signs out users, as well as connects users to the vast amounts of data they generate. With a high interactive capability, the system allows users (like patients) to retrieve and view their data and records, as well as communicate with the cloud users (like physicians). The resulting mobile edge system is promising and is expected to demonstrate the potential of smart and secure big data interaction.</p> <p>The smart and secure transmission and management of the big data on the cloud is essential for healthcare big data, including both patient information and patient measurements. The second major contribution of this thesis is to demonstrate a novel big data cloud system, s²Cloud, which can help enhance healthcare systems to better monitor patients and give doctors critical insights into their patients' health. s²Cloud achieves big data security through secure sign up and log in for the doctors, as well as data transmission protection. The system allows the doctors to manage both patients and their records effectively. The doctors can add and edit the patient and record information through the interactive website. Furthermore, the system supports both real-time and historical modes for big data management. Therefore, the patient measurement information can, not only be visualized and demonstrated in real-time, but also be retrieved for further analysis. The smart website also allows doctors and patients to interact with each other effectively through instantaneous chat. Overall, the proposed s²Cloud system, empowered by smart secure design innovations, has demonstrated the feasibility and potential for healthcare big data applications. This study will further broadly benefit and advance other smart home and world big data applications. </p>

Switching from traditional information technology to cloud based technology is becoming more common for organizations looking to obtain benefits such as scalability, pay-per-use, and increased availability. A cloud migration is a project of high-level complexity, and having a methodological step-by-step approach can assist an organization through the process. Although there is a substantial amount of research on cloud migration, there is a lack of step-by-step descriptions to guide organizations looking to switch to cloud technology.  This is a case study evaluation of a cloud migration, where the cloud migration process is explored and compared to established frameworks for cloud migration. The case study organization is a large Swedish retail company that performed a cloud migration between 2020-2022, when switching from a legacy point-of-sale system to a cloud based application for commerce. Data collection consisted of a document review, an archival data review, and a survey that was sent out to end users of the cloud application. These three methods were selected to obtain triangulation of data and to provide an accurate description of the cloud migration process of the case study organization.  The results of the study demonstrate that the evaluated cloud migration process had many similarities to the frameworks for cloud migration, although with differences in order of execution and emphasis on activities. Challenges experienced during the cloud migration process were related to interoperability, project complexity, and having a third-party service provider. By contrast, success factors of the cloud migration were proper planning for support flow and deployment, having substantial user support, and sufficient training for end users.  This study provides a description of an executed cloud migration with an overview of the process from start to finish, along with insights into challenges and lessons learned regarding project execution. This could be of value for organizations looking to migrate from legacy applications to cloud based applications.

Information Technology (IT) leaders must leverage cloud computing to maintain competitive advantage. Evidence suggests that IT leaders who have leveraged cloud computing in small and medium sized organizations have saved an average of $1 million in IT services for their organizations. The purpose of this qualitative single case study was to explore strategies that IT leaders use to adopt cloud computing for their organizations. The target population consisted of 15 IT leaders who had experience with designing and deploying cloud computing solutions at their organization in Long Island, New York within the past 2 years. The conceptual framework of this research project was the disruptive innovation theory. Semistructured interviews were conducted and company documents were gathered. Data were inductively analyzed for emergent themes, then subjected to member checking to ensure the trustworthiness of findings. Four main themes emerged from the data: the essential elements for strategies to adopt cloud computing; most effective strategies; leadership essentials; and barriers, critical factors, and ineffective strategies affecting adoption of cloud computing. These findings may contribute to social change by providing insights to IT leaders in small and medium sized organizations to save money while gaining competitive advantage and ensure sustainable business growth that could enhance community standards of living.

La haute performance ainsi que la basse consommation d’énergie offertes par lesField-Programmable Gate Arrays (FPGAs) contribuent à leur popularité en tant queaccélérateurs matériels. Cet argument a été soutenu par les intégrations récentes des FPGAs dans des systèmes cloud et centre de données. Toutefois, le potentiel d’une architecture reconfigurable peut être encore optimisé en traitant les FPGAs comme une ressource virtualisée et en les offrant une capacité de multitâche. La solution pour interrompre une tâche sur FPGAs à pour objectif d’effectuer un changement de contexte matériel (hardware context switch) a été un sujet de recherche depuis des nombreuses années. Les travaux précédents ont principalement proposé une stratégie pour extraire le contexte d’une tâche en cours de son exécution d’un FPGA pour offrir la possibilité de sa reprise plus tard. Cependant, la communication tout au long du processus n’a pas reçu autant d’attention.Dans cette thèse, nous étudions la gestion de communication d’une tâche matérielle durant son changement de contexte. Cette gestion de communicationest nécessaire pour garantir la cohérence de la communication d’une tâche dans un système reconfigurable avec la capacité de changement de contexte. Autrement, un changement de contexte matériel est seulement autorisé sous des contraintes restrictifs; il est possible après que les flux de communication soient fini et que toutes les données d’entrées/de sorties sont déjà consommées. De plus, certaines techniques demandent l’homogénéité au sein de la plate-forme pour qu’un changement de contexte matériel puisse se réaliser.Nous présentons içi un mécanisme qui conserve la cohérence de communication durant un changement de contexte matériel dans une architecture reconfigurable. Les données de communication sont gérées avec le contexte de tâche pour assurer leur intégrité. La gestion du contexte et les données de communication suivent un protocole spécifique pour des architectures hétérogènes reconfigurables. Ce protocole permet donc un changement de contexte matériel pendant que la tâche a encore des flux de communication. À partir des expérimentations, nous découvrons que le surcoût de la gestion de communication devient négligeable car notre mécanisme fournit une grande réactivité nécessaire pour l’allocation de tâche de façon préemptive - outre que sa consistance de communication. Enfin, les applications de solution proposée sont présentées dans un prototypage de tâche migration et dans un système utilisant un hyperviseur. / Field-Programmable Gate Arrays (FPGAs) have been gaining popularity as hardware accelerators in heterogeneous architectures thanks to their high performance and low energy consumption. This argument has been supported by the recent integration of FPGA devices in cloud services and data centers. The potential offered by the reconfigurable architectures can still be optimized by treating FPGAs as virtualizable resources and offering them multitasking capability. The solution to preempt a hardware task on an FPGA with the objective of context switching it has been in research for many years. The previous works mainly proposed the strategy to extract the context of a running task from the FPGA to provide the possibility of its resumption at a later time. The communication during the process, on the contrary, has not been receiving much attention.In this work, we study the communication management of a hardware task whileit is being context switched. This communication management is necessary to ensure the consistency in the communication of a task with context switch capability in a reconfigurable system. Otherwise, a hardware context switch can only be allowed under restrictive constraints which may lead to a considerable penalty in performance; context switching a task is possible after the communication flows finish and the input/output data have been consumed. Furthermore, certain techniques demand homogeneity in the platform for a hardware context switch can take place.We present a mechanism which preserves the communication consistency during ahardware context switch in a reconfigurable architecture. The input/output communication data are managed together with the task context to ensure their integrity. The overall management of the hardware task context and communication data follows a dedicated protocol developed for heterogeneous reconfigurable architectures. This protocol thus allows a hardware context switch to take place while the task still has ongoing communication flows on Reconfigurable System-on-Chips (RSoCs). From the experiments, we discover that the overhead due to managing the communication data becomes negligible since our mechanism provides the necessary high responsiveness for preemptive scheduling, besides the consistency in communication. Finally, the applications of the proposed solution are presented in a task migration prototyping and in a hypervisor-based system.

Le Cloud Computing est devenu l'un des grands paradigmes de l'informatique et propose de fournir les ressources informatiques sous forme de services accessibles au travers de l'Internet. Ces services sont généralement organisés selon trois types ou niveaux. On parle de modèle SPI pour “Software, Platform, Infrastructure” en anglais. De la même façon que pour les applications ``standard'', les services de Cloud doivent être capables de s'adapter de manière autonome afin de tenir compte de l'évolution de leur environnement. À ce sujet, il existe de nombreux travaux tels que ceux concernant la consolidation de serveur et l'économie d'énergie. Mais ces travaux sont généralement spécifiques à l'un des niveaux et ne tiennent pas compte des autres. Pourtant, comme l'a affirmé Kephart et al. en 2000, même s'il existe des adaptations à priori indépendantes les unes des autres, celles-ci ont un impact sur l'ensemble du système informatique dans lequel elles sont appliquées. De ce fait, une adaptation au niveau infrastructure peut avoir un impact au niveau plate-forme ou au niveau application. L'objectif de cette thèse est de fournir un support pour l'adaptation permettant de gérer celle-ci comme une problématique transverse au différents niveaux afin d'assurer la cohérence et l'efficacité de l'adaptation. Pour cela, nous proposons une abstraction capable de représenter l'ensemble des niveaux et servant de support pour la définition des reconfigurations. Cette abstraction repose sur les techniques de modèle à l'exécution (Model at Runtime en anglais) qui propose de porter les outils utilisés à la conception pour définir, valider et appliquer une nouvelle configuration pendant l'exécution du système lui-même. Afin de montrer l'utilisabilité de cette abstraction, nous présentons trois expérimentations permettant de montrer l'extensibilité et la généricité de notre solution, de montrerque l'impact sur les performances du système est faible, et de montrer que cette abstraction permet de faire de l'adaptation multiniveaux. / Cloud Computing is becoming the new paradigm for information technology to provide resources as Internet-based services. These services are basically categorized according to three layers also called SPI model (Software, Platform, Infrastructure). The same way as ``non-Cloud'' applications, Cloud services must be able to adapt themselves according to the evolution of their environment. There are many works on dynamic adaptation such as server consolidation and green computing but these works are generally specifics to one layer and do not take the others into account. However Kephart et al. have explain in 2000 that even if adaptations are, in theory, independant, they have an impact on the overall system. Consequently, an adaptation at the infrastructure layer can have an impact at the platform or at the application layers.This thesis provides an abstraction to manage adaptation as an orthogonal concern overs Cloud layers. Based on Model atRuntime (M@R) techniques which offer to use design tools to build and validate new configuration of the system at the runtime, this abstraction is able to modelize all the Cloud layers. To show the usability of this abstraction, we provide three experimentations showing the extensibility and genericity of our approach, showing that performance overhead on the system (infrastructure or platform) is weak and showing that the abstraction allows to build multi-layers adaptations.

Thin clouds are the most difficult cloud type to observe. The recent availability of joint cloud products from the active remote sensing instruments aboard CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) facilitates the study of these clouds. Using one of these joint cloud products, 2B-GEOPROF-Lidar, and a post-processing algorithm designed to find horizontally continuous thin clouds within the cloud product, the locations, length scales, and vertical distributions by length of thin clouds are determined. It is found that thin clouds vary in length from a few km to over 2900 km and tend to be longer in the tropical upper troposphere than lower in the atmosphere and at higher latitudes. In the upper troposphere between 0° and 40°N, over 20% of all thin cloud measurements in the 2B-GEOPROF-Lidar product are contributed by thin clouds that are longer than 500 km. In fact, in this latitude range, over 65% of all thin cloud measurements are contributed by clouds longer than 100 km. Also, thin cloud length and frequency differ between the four seasons in the year of data used here.

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Cloud computing has a significant impact on information and communication technology (ICT) and is one of the most important technological drivers of the digitalization of enterprises. However, due to the increasing dissemination of cloud services and the growing number of cloud service providers (CSPs), the uncertainty and risks for user companies in adopting cloud services have also increased. In this paper, we address those aspects from the perspective of the CSPs. We identified relevant literature and studies and conducted interviews with business experts from 16 German CSPs. In our results, we present current customer requirements and barriers to using cloud services from a provider’s viewpoint and identify the actions of and obstacles for CSPs in meeting the needs and constraints of the customers. Finally, we identify current and future challenges for CSPs in dealing with customer requirements and barriers by addressing their root causes. One of the main challenges from the CSPs’ perspective is addressing customers appropriately and building relationships of trust. This also “forces” changes in the sales processes. In this process, the essential challenges can be identified as an increase in complexity and a simultaneous simplification of specific sales activities. Therefore, the necessity arises for the continuous support of business relationships through value-adding and additional services. However, this results in another challenge for the CSPs – Namely, to find the right balance between standardization and meeting customer-specific requirements. In our paper, we show that the perspective of the CSPs is rarely discussed in the literature. Nevertheless, understanding the perceptions of the providers and their actions and measures is essential for future research activities in the field of cloud service selection. Comparing the customers’ perspectives and viewpoints with the CSPs’ actions will enhance the development of a holistic selection approach for future cloud projects. Therefore, our paper’s contribution to research is also the identification of this missing integration.