96 research outputs found
SAP HANA distributed in-memory database system: Transaction, session, and metadata management
One of the core principles of the SAP HANA database system is the comprehensive support of distributed query facility. Supporting scale-out scenarios was one of the major design principles of the system from the very beginning. Within this paper, we first give an overview of the overall functionality with respect to data allocation, metadata caching and query routing. We then dive into some level of detail for specific topics and explain features and methods not common in traditional disk-based database systems. In summary, the paper provides a comprehensive overview of distributed query processing in SAP HANA database to achieve scalability to handle large databases and heterogeneous types of workloads
DDoS Capability and Readiness - Evidence from Australian Organisations
A common perception of cyber defence is that it should protect systems and data from malicious attacks, ideally keeping attackers outside of secure perimeters and preventing entry. Much of the effort in traditional cyber security defence is focused on removing gaps in security design and preventing those with legitimate permissions from becoming a gateway or resource for those seeking illegitimate access. By contrast, Distributed Denial of Service (DDoS) attacks do not use application backdoors or software vulnerabilities to create their impact. They instead utilise legitimate entry points and knowledge of system processes for illegitimate purposes. DDoS seeks to overwhelm system and infrastructure resources so that legitimate requests are prevented from reaching their intended destination. For this thesis, a literature review was performed using sources from two perspectives. Reviews of both industry literature and academic literature were combined to build a balanced view of knowledge of this area. Industry and academic literature revealed that DDoS is outpacing internet growth, with vandalism, criminal and ideological motivations rising to prominence. From a defence perspective, the human factor remains a weak link in cyber security due to proneness for mistakes, oversights and the variance in approach and methods expressed by differing cultures. How cyber security is perceived, approached, and applied can have a critical effect on the overall outcome achieved, even when similar technologies are implemented. In addition, variance in the technical capabilities of those responsible for the implementation may create further gaps and vulnerabilities. While discussing technical challenges and theoretical concepts, existing literature failed to cover the experiences held by the victim organisations, or the thoughts and feelings of their personnel. This thesis addresses these identified gaps through exploratory research, which used a mix of descriptive and qualitative analysis to develop results and conclusions. The websites of 60 Australian organisations were analysed to uncover the level and quality of cyber security information they were willing to share and the methods and processes they used to engage with their audience. In addition, semi-structured interviews were conducted with 30 employees from around half of those websites analysed. These were analysed using NVivo12 qualitative analysis software. The difficulty experienced with attracting willing participants reflected the comfort that organisations showed with sharing cyber security information and experiences. However, themes found within the results show that, while DDoS is considered a valid threat, without encouragement to collaborate and standardise minimum security levels, firms may be missing out on valuable strategies to improve their cyber security postures. Further, this reluctance to share leads organisations to rely on their own internal skill and expertise, thus failing to realise the benefits of established frameworks and increased diversity in the workforce. Along with the size of the participant pool, other limitations included the diversity of participants and the impact of COVID-19 which may have influenced participants' thoughts and reflections. These limitations however, present opportunity for future studies using greater participant numbers or a narrower target focus. Either option would be beneficial to the recommendations of this study which were made from a practical, social, theoretical and policy perspective. On a practical and social level, organisational capabilities suffer due to the lack of information sharing and this extends to the community when similar restrictions prevent collaboration. Sharing of knowledge and experiences while protecting sensitive information is a worthy goal and this is something that can lead to improved defence. However, while improved understanding is one way to reduce the impact of cyber-attacks, the introduction of minimum cyber security standards for products, could reduce the ease at which devices can be used to facilitate attacks, but only if policy and effective governance ensures product compliance with legislation. One positive side to COVID-19's push to remote working, was an increase in digital literacy. As more roles were temporarily removed from their traditional physical workplace, many employees needed to rapidly accelerate their digital competency to continue their employment. To assist this transition, organisations acted to implement technology solutions that eased the ability for these roles to be undertaken remotely and as a consequence, they opened up these roles to a greater pool of available candidates. Many of these roles are no longer limited to the geographical location of potential employees or traditional hours of availability. Many of these roles could be accessed from almost anywhere, at any time, which had a positive effect on organisational capability and digital sustainability
Design of a strategic plan for the creation of an online education and advisory platform focused on personal finance
The thesis explores the development of strategic plan to design a platform aimed at addressing the problem of financial illiteracy. The primary objective of the thesis was to design an online platform that provides educational resources and advisory services to combat financial illiteracy. To achieve this goal, thorough research has been conducted on the industry, delving into its current state, trends, and challenges. Understanding the industry landscape has served as a foundation for formulating an effective strategic plan. The study also focuses on understanding the potential end users of the platform. Through in-depth analysis, this thesis aims to gain insights into their needs, preferences, and behaviours. This understanding played a crucial role in shaping the platform's features, usability, and user experience. Additionally, the thesis examines existing competitors in the market. By conducting a comprehensive competitor analysis, it has been tried to identify the strengths and weaknesses of established players in the industry. This analysis facilitated the development of a unique value proposition for the proposed platform. A significant aspect of the thesis involved exploring design alternatives for the platform. This project discusses different approaches, considering factors such as user interface design, technical infrastructure, and scalability. A crucial point of consideration is the debate between open- source and proprietary software, weighing the advantages and disadvantages of each approach. Lastly, financial projections are also included in the thesis to assess the platform's potential viability. This has been done by conducting a detailed financial analysis, forecasting revenue streams, cost structures, and potential growth trajectories. These projections aim to provide valuable insights into the platform's economic sustainability and future prospects. Based on the comprehensive research and analysis, the thesis concludes that the development of an online education and advisory platform focused on personal finance is a complex endeavour. The industry requires deep expertise and knowledge to effectively address financial illiteracy. Additionally, the thesis recommends the next steps to be the transition from conceptualization to implementation by building the platform. It is emphasized the importance of reinforcing the team with key profiles to ensure the platform's long-term sustainabilit
Online and Distance Education for a Connected World
Learning at a distance and learning online are growing in scale and importance in higher education, presenting opportunities for large scale, inclusive, flexible and engaging learning. These modes of learning swept the world in response to the Covid-19 pandemic. The many challenges of providing effective education online and remotely have been acknowledged, particularly by those who rapidly jumped into online and distance education during the crisis.
This volume, edited by the University of London’s Centre for Online and Distance Education, addresses the practice and theory of online and distance education, building on knowledge and expertise developed in the University over some 150 years. The University is currently providing distance transnational education to around 50,000 students in more than 180 countries around the world. Throughout the book, contributors explore important principles and highlight successful practices in areas including course design and pedagogy, online assessment, open education, inclusive practice, and enabling student voice. Case studies illustrate prominent issues and approaches. Together, the chapters offer current and future leaders and practitioners a practical, productive, practice- and theory-informed account of the present and likely future state of online and distance higher education worldwide
Engage in Public Scholarship! A Guidebook on Feminist and Accessible Communication
Public scholarship – sharing research with audiences outside of academic settings – has become increasingly necessary to counter the rise of misinformation, to fill gaps from cuts to traditional media, and to increase the reach of important scholarship by making it available to the public. However, engaging in these efforts also comes with the risk of harassment and threats – especially for women, people of colour, queer communities, and precariously employed workers. Engage in Public Scholarship! provides constructive guidance on how to translate research into inclusive public outreach while ensuring that such efforts are accessible for a range of abilities as well as safer for those involved.
In clear and helpful language, Alex D. Ketchum discusses practices and planning for a great range of educational activities – from in-person and online events, conferences, and lectures, to publishing and working with the media, to social media activity, blogging, and podcasting. Using an intersectional feminist lens, this book serves as a concise approach to the key challenges and benefits of feminist and accessible public scholarship by surveying debates and offering solutions. Examining the needs for long-term preservation and impact, Ketchum discusses issues relating to digital sustainability, maintenance, the concept of “openness,” and how to be mindful of exclusionary barriers that impede access.
A useful and readable guidebook for scholars, students, and content creators, Engage in Public Scholarship! offers both encouragement and toolkits for reaching audiences and sharing knowledge in practical and more equitable ways.
Dr. Alex D. Ketchum is an Assistant Professor at the Institute for Gender, Sexuality, and Feminist Studies of McGill University
Scale aware modeling and monitoring of the urban energy chain
With energy modeling at different complexity levels for smart cities and the concurrent data availability revolution from connected devices, a steady surge in demand for spatial knowledge has been observed in the energy sector. This transformation occurs in population centers focused on efficient energy use and quality of life. Energy-related services play an essential role in this mix, as they facilitate or interact with all other city services. This trend is primarily driven by the current age of the Ger.: Energiewende or energy transition, a worldwide push towards renewable energy sources, increased energy use efficiency, and local energy production that requires precise estimates of local energy demand and production. This shift in the energy market occurs as the world becomes aware of human-induced climate change, to which the building stock has a significant contribution (40% in the European Union). At the current rate of refurbishment and building replacement, of the buildings existing in 2050 in the European Union, 75% would not be classified as energy-efficient. That means that substantial structural change in the built environment and the energy chain is required to achieve EU-wide goals concerning environmental and energy policy. These objectives provide strong motivation for this thesis work and are generally made possible by energy monitoring and modeling activities that estimate the urban energy needs and quantify the impact of refurbishment measures.
To this end, a modeling library called aEneAs was developed in the scope of this thesis that can perform city-wide building energy modeling. The library performs its tasks at the level of a single building and was a first in its field, using standardized spatial energy data structures that allow for portability from one city to another. For data input, extensive use was made of digital twins provided from CAD, BIM, GIS, architectural models, and a plethora of energy data sources. The library first quantifies primary thermal energy demand and then the impact of refurbishment measures. Lastly, it estimates the potential of renewable energy production from solar radiation. aEneAs also includes network modeling components that consider energy distribution in the given context, showing a path toward data modeling and simulation required for distributed energy production at the neighborhood and district level.
In order to validate modeling activities in solar radiation and green façade and roof installations, six spatial models were coupled with sensor installations. These digital twins are included in three experiments that highlight this monitoring side of the energy chain and portray energy-related use cases that utilize the spatially enabled web services SOS-SES-WNS, SensorThingsAPI, and FIWARE. To this author\u27s knowledge, this is the first work that surveys the capabilities of these three solutions in a unifying context, each having its specific design mindset.
The modeling and monitoring activity and their corresponding literature review indicated gaps in scientific knowledge concerning data science in urban energy modeling. First, a lack of standardization regarding the spatial scales at which data is stored and used in urban energy modeling was observed. In order to identify the appropriate spatial levels for modeling and data aggregation, scale is explored in-depth in the given context and defined as a byproduct of resolution and extent, with ranges provided for both parameters. To that end, a survey of the encountered spatial scales and actors in six different geographical and cultural settings was performed. The information from this survey was used to put forth a standardized spatial scales definition and create a scale-dependent ontology for use in urban energy modeling. The ontology also provides spatially enabled persistent identifiers that resolve issues encountered with object relationships in modeling for inheritance, dependency, and association. The same survey also reveals two significant issues with data in urban energy modeling. These are data consistency across spatial scales and urban fabric contiguity. The impact of these issues and different solutions such as data generalization are explored in the thesis.
Further advancement of scientific knowledge is provided specifically with spatial standards and spatial data infrastructure in urban energy modeling. A review of use cases in the urban energy chain and a taxonomy of the standards were carried out. These provide fundamental input for another piece of this thesis: inclusive software architecture methods that promote data integration and allow for external connectivity to modern and legacy systems. In order to reduce time-costly extraction, transformation, and load processes, databases and web services to ferry data to and from separate data sources were used. As a result, the spatial models become central linking elements of the different types of energy-related data in a novel perspective that differs from the traditional one, where spatial data tends to be non-interoperable / not linked with other data types. These distinct data fusion approaches provide flexibility in an energy chain environment with inconsistent data structures and software. Furthermore, the knowledge gathered from the experiments presented in this thesis is provided as a synopsis of good practices
Volume II Acquisition Research Creating Synergy for Informed Change, Thursday 19th Annual Acquisition Research Proceedings
ProceedingsApproved for public release; distribution is unlimited
Formal Foundations for Information-Preserving Model Synchronization Processes Based on Triple Graph Grammars
Zwischen verschiedenen Artefakten, die Informationen teilen, wieder Konsistenz herzustellen, nachdem eines von ihnen geändert wurde, ist ein wichtiges Problem, das in verschiedenen Bereichen der Informatik auftaucht. Mit dieser Dissertation legen wir eine Lösung für das grundlegende Modellsynchronisationsproblem vor. Bei diesem Problem ist ein Paar solcher Artefakte (Modelle) gegeben, von denen eines geändert wurde; Aufgabe ist die Wiederherstellung der Konsistenz. Tripelgraphgrammatiken (TGGs) sind ein etablierter und geeigneter Formalismus, um dieses und verwandte Probleme anzugehen. Da sie auf der algebraischen Theorie der Graphtransformation und dem (Double-)Pushout Zugang zu Ersetzungssystemen basieren, sind sie besonders geeignet, um Lösungen zu entwickeln, deren Eigenschaften formal bewiesen werden können. Doch obwohl TGG-basierte Ansätze etabliert sind, leiden viele von ihnen unter dem Problem des Informationsverlustes. Wenn ein Modell geändert wurde, können während eines Synchronisationsprozesses Informationen verloren gehen, die nur im zweiten Modell vorliegen. Das liegt daran, dass solche Synchronisationsprozesse darauf zurückfallen Konsistenz dadurch wiederherzustellen, dass sie das geänderte Modell (bzw. große Teile von ihm) neu übersetzen. Wir schlagen einen TGG-basierten Ansatz vor, der fortgeschrittene Features von TGGs unterstützt (Attribute und negative Constraints), durchgängig formalisiert ist, implementiert und inkrementell in dem Sinne ist, dass er den Informationsverlust im Vergleich mit vorherigen Ansätzen drastisch reduziert. Bisher gibt es keinen TGG-basierten Ansatz mit vergleichbaren Eigenschaften.
Zentraler Beitrag dieser Dissertation ist es, diesen Ansatz formal auszuarbeiten und seine wesentlichen Eigenschaften, nämlich Korrektheit, Vollständigkeit und Termination, zu beweisen. Die entscheidende neue Idee unseres Ansatzes ist es, Reparaturregeln anzuwenden. Dies sind spezielle Regeln, die es erlauben, Änderungen an einem Modell direkt zu propagieren anstatt auf Neuübersetzung zurückzugreifen. Um diese Reparaturregeln erstellen und anwenden zu können, entwickeln wir grundlegende Beiträge zur Theorie der algebraischen Graphtransformation. Zunächst entwickeln wir eine neue Art der sequentiellen Komposition von Regeln. Im Gegensatz zur gewöhnlichen Komposition, die zu Regeln führt, die Elemente löschen und dann wieder neu erzeugen, können wir Regeln herleiten, die solche Elemente stattdessen bewahren. Technisch gesehen findet der Synchronisationsprozess, den wir entwickeln, außerdem in der Kategorie der partiellen Tripelgraphen statt und nicht in der der normalen Tripelgraphen. Daher müssen wir sicherstellen, dass die für Double-Pushout-Ersetzungssysteme ausgearbeitete Theorie immer noch gültig ist. Dazu entwickeln wir eine (kategorientheoretische) Konstruktion neuer Kategorien aus gegebenen und zeigen, dass (i) diese Konstruktion die Axiome erhält, die nötig sind, um die Theorie für Double-Pushout-Ersetzungssysteme zu entwickeln, und (ii) partielle Tripelgraphen als eine solche Kategorie konstruiert werden können. Zusammen ermöglichen diese beiden grundsätzlichen Beiträge es uns, unsere Lösung für das grundlegende Modellsynchronisationsproblem vollständig formal auszuarbeiten und ihre zentralen Eigenschaften zu beweisen.Restoring consistency between different information-sharing artifacts after one of them has been changed is an important problem that arises in several areas of computer science. In this thesis, we provide a solution to the basic model synchronization problem. There, a pair of such artifacts (models), one of which has been changed, is given and consistency shall be restored. Triple graph grammars (TGGs) are an established and suitable formalism to address this and related problems. Being based on the algebraic theory of graph transformation and (double-)pushout rewriting, they are especially suited to develop solutions whose properties can be formally proven. Despite being established, many TGG-based solutions do not satisfactorily deal with the problem of information loss. When one model is changed, in the process of restoring consistency such solutions may lose information that is only present in the second model because the synchronization process resorts to restoring consistency by re-translating (large parts of) the updated model. We introduce a TGG-based approach that supports advanced features of TGGs (attributes and negative constraints), is comprehensively formalized, implemented, and is incremental in the sense that it drastically reduces the amount of information loss compared to former approaches. Up to now, a TGG-based approach with these characteristics is not available.
The central contribution of this thesis is to formally develop that approach and to prove its essential properties, namely correctness, completeness, and termination. The crucial new idea in our approach is the use of repair rules, which are special rules that allow one to directly propagate changes from one model to the other instead of resorting to re-translation. To be able to construct and apply these repair rules, we contribute more fundamentally to the theory of algebraic graph transformation. First, we develop a new kind of sequential rule composition. Whereas the conventional composition of rules leads to rules that delete and re-create elements, we can compute rules that preserve such elements instead. Furthermore, technically the setting in which the synchronization process we develop takes place is the category of partial triple graphs and not the one of ordinary triple graphs. Hence, we have to ensure that the elaborate theory of double-pushout rewriting still applies. Therefore, we develop a (category-theoretic) construction of new categories from given ones and show that (i) this construction preserves the axioms that are necessary to develop the theory of double-pushout rewriting and (ii) partial triple graphs can be constructed as such a category. Together, those two more fundamental contributions enable us to develop our solution to the basic model synchronization problem in a fully formal manner and to prove its central properties
Ami-deu : un cadre sémantique pour des applications adaptables dans des environnements intelligents
Cette thèse vise à étendre l’utilisation de l'Internet des objets (IdO) en facilitant le développement d’applications par des personnes non experts en développement logiciel. La thèse propose une nouvelle approche pour augmenter la sémantique des applications d’IdO et l’implication des experts du domaine dans le développement d’applications sensibles au contexte. Notre approche permet de gérer le contexte changeant de l’environnement et de générer des applications qui s’exécutent dans plusieurs environnements intelligents pour fournir des actions requises dans divers contextes. Notre approche est mise en œuvre dans un cadriciel (AmI-DEU) qui inclut les composants pour le développement d’applications IdO. AmI-DEU intègre les services d’environnement, favorise l’interaction de l’utilisateur et fournit les moyens de représenter le domaine d’application, le profil de l’utilisateur et les intentions de l’utilisateur. Le cadriciel permet la définition d’applications IoT avec une intention d’activité autodécrite qui contient les connaissances requises pour réaliser l’activité. Ensuite, le cadriciel génère Intention as a Context (IaaC), qui comprend une intention d’activité autodécrite avec des connaissances colligées à évaluer pour une meilleure adaptation dans des environnements intelligents.
La sémantique de l’AmI-DEU est basée sur celle du ContextAA (Context-Aware Agents) – une plateforme pour fournir une connaissance du contexte dans plusieurs environnements. Le cadriciel effectue une compilation des connaissances par des règles et l'appariement sémantique pour produire des applications IdO autonomes capables de s’exécuter en ContextAA. AmI- DEU inclut également un outil de développement visuel pour le développement et le déploiement rapide d'applications sur ContextAA. L'interface graphique d’AmI-DEU adopte la métaphore du flux avec des aides visuelles pour simplifier le développement d'applications en permettant des définitions de règles étape par étape. Dans le cadre de l’expérimentation, AmI-DEU comprend un banc d’essai pour le développement d’applications IdO. Les résultats expérimentaux montrent une optimisation sémantique potentielle des ressources pour les applications IoT dynamiques dans les maisons intelligentes et les villes intelligentes.
Notre approche favorise l'adoption de la technologie pour améliorer le bienêtre et la qualité de vie des personnes. Cette thèse se termine par des orientations de recherche que le cadriciel AmI-DEU dévoile pour réaliser des environnements intelligents omniprésents fournissant des adaptations appropriées pour soutenir les intentions des personnes.Abstract: This thesis aims at expanding the use of the Internet of Things (IoT) by facilitating the development of applications by people who are not experts in software development. The thesis proposes a new approach to augment IoT applications’ semantics and domain expert involvement in context-aware application development. Our approach enables us to manage the changing environment context and generate applications that run in multiple smart environments to provide required actions in diverse settings. Our approach is implemented in a framework (AmI-DEU) that includes the components for IoT application development. AmI- DEU integrates environment services, promotes end-user interaction, and provides the means to represent the application domain, end-user profile, and end-user intentions. The framework enables the definition of IoT applications with a self-described activity intention that contains the required knowledge to achieve the activity. Then, the framework generates Intention as a Context (IaaC), which includes a self-described activity intention with compiled knowledge to be assessed for augmented adaptations in smart environments. AmI-DEU framework semantics adopts ContextAA (Context-Aware Agents) – a platform to provide context-awareness in multiple environments. The framework performs a knowledge compilation by rules and semantic matching to produce autonomic IoT applications to run in ContextAA. AmI-DEU also includes a visual tool for quick application development and deployment to ContextAA. The AmI-DEU GUI adopts the flow metaphor with visual aids to simplify developing applications by allowing step-by-step rule definitions. As part of the experimentation, AmI-DEU includes a testbed for IoT application development. Experimental results show a potential semantic optimization for dynamic IoT applications in smart homes and smart cities. Our approach promotes technology adoption to improve people’s well-being and quality of life. This thesis concludes with research directions that the AmI-DEU framework uncovers to achieve pervasive smart environments providing suitable adaptations to support people’s intentions
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