Today, computer networks are dominated by data distribution and content retrieval, but technology was created for communication between hosts. Content and service access requires mappnig between what users want and where in network it can be found. Content-centric networks separate content from its location. This thesis aims to security of Content-centric networks, looks for weak spots in its design and suggests steps for improvements of their security.

Dans les dernières années, l’utilisation d’Internet a sensiblement changé en passant d’un modèle de communication centré sur les machines á un centré sur les contenus. La plus part de services utilisés par les clients d’Internet aujourd’hui sont déjà centré sur les contenus même et pas sur leurs emplacement. Dans ce contexte, beaucoup de projets de recherche proposent un changement de l’architecture de l’Internet, en mettent des contenu identifié par leur nom au centre du réseau. Ce group de proposition est identifiés sous le nom de Information Centric Networking (ICN). Cette thèse se focalise sur la proposition Content-Centric Network (CCN). Dans une premier temps, nous analysons les performance du modèle de communication CCN en se concentrent sur le partage de la bande passante et de la mémoire et en proposant des formules pour la caractérisation du temps de transfert. Deuxièmement, nous proposons un protocole de contrôle de congestion et des mécanismes de forwarding pour CCN. En particulier on présent un premier mécanisme de contrôle de congestion, Interest Control Protocol (ICP), qui utilise une fenêtre contrôlé avec le mécanisme Additive Increase Multiplicative Decrease au récepteur. En complément avec ça, nous présentons un mécanisme distribué (hop-by-hop) pour obtenir une détection/réaction à la congestion plus rapide. Nous proposons aussi une modification d'ICP en implémentant le mécanisme Remote Adaptive Active Queue Management pour exploiter efficacement le multi-chemin. En fin, nous présentons un mécanisme de forwarding distribué qui base ses décisions sur des mesure de qualité d’interface par chaque préfixe disponible dans les tableaux de routage. / The advent of the World Wide Web has radically changed Internet usage from host-to-host to service access and data retrieval. The majority of services used by Internet’s clients are content-centric (e.g. web). However, the original Internet revolves around host-to-host communication for which it was conceived. Even if Internet has been able to address the challenges offered by new applications, there is an evident mismatch between the architecture and its current usage. Many projects in national research agencies propose to redesign the Internet architecture around named data. Such research efforts are identified under the name of Information Centric Networking. This thesis focuses on the Content-Centric Networking (CCN) proposition. We first analyze the CCN communication model with particular focus on the bandwidth and storage sharing performance, We compute closed formulas for data delivery time, that we use in the second part of the thesis as guideline for network protocol design. Second, we propose some CCN congestion control and forwarding mechanisms. We present a first window based receiver driven flow control protocol, Interest Control Protocol (ICP). We also introduce a hop-by-hop congestion control mechanism to obtain early congestion detection and reaction. We then extend the original ICP congestion control protocol implementing a Remote Adaptive Active Queue Management mechanism in order to efficiently exploit heterogeneous (joint/disjoint) network paths. Finally, we introduce a distributed forwarding mechanism that bases its decisions on per prefix and per interface quality measurement without impacting the system scalability.

Modern changes in lifestyle have inadvertently disconnected urban inhabitants from experiences known to be good for our well-being, including spending time in nature and having a sense of community and connectedness to those around us. We spend 90% of our time indoors in limited and artificial environments, mostly in our homes or places of work. The internet and a global pandemic have advanced this disconnection to our surroundings through the rise of remote work and a slew of apps ready to deliver whatever you desire to your front door. This thesis seeks to remedy these unintended consequences of modernity by reconnecting District of Columbia residents back to nature and to their surrounding communities through the design of a public library that incorporates nature to promote the holistic health of the community and the individual. The incorporation of nature into the built environment is proven to have physiological and psychological benefits and improve overall well-being. Neighborhood libraries have always been important institutions in our social infrastructure; functioning as places of self improvement, providing free resources, and acting as central public spaces in the communities they serve. In urban environments where public and private outdoor spaces are limited, a beneficial experience of nature can be one of the resources that public libraries provide to their communities. Through the use of natural materials, vegetation, passive ventilation, and natural light, this project utilizes biophilic design to promote wellbeing, enhanced cognition, and create a welcoming environment that draws District residents out of their homes and together to create a sense of community. The proposed project pairs D.C. Branch Library programming with outdoor spaces, including a courtyard and a public plaza, creating a permeable indoor/outdoor social center within the dense Washington D.C. neighborhood of Adams Morgan. The neighborhood is vegetated by a field of ginkgo trees taking over 18th Street and an lush internal courtyard between the library's volumes. Community oriented spaces are located on the ground level of the site while the traditional library volume becomes an urban oasis floating over the plaza in a sea of trees. / Master of Architecture / Living in urban areas and the continuing shift of professional and social interactions to online have disconnected people from experiences known to be good for our well-being, including spending time in nature and having a sense of community and connectedness to those around us. This thesis seeks to reconnect Washington D.C. residents back to nature and their surrounding communities through the design of a public library that incorporates elements of nature, which have physical and mental health benefits and improve overall well-being. Libraries have always been an important anchor in their neighborhoods, providing free resources and acting as central public spaces in the communities they serve. In dense urban environments where public and private outdoor spaces are limited, access to nature can be one of the resources that public libraries provide to their communities. This project incorporates elements of nature, like natural materials, plants, passive airflow, and natural light, to promote wellbeing, enhanced cognition, and create a welcoming environment that draws D.C. residents out of their homes and together to create a sense of community. The proposed project is a D.C. branch library with added outdoor spaces, including a courtyard and a public plaza, creating a permeable indoor/outdoor social center within the dense Washington D.C. neighborhood of Adams Morgan. The new plaza and courtyard are each populated by trees to green the neighborhood. Louder, gathering areas of the building are located on the ground level and the quieter traditional library spaces are located on the overhanging upper levels which become an urban oasis floating over the plaza in a sea of trees.

Smart grid is a power supply system that uses digital communication technology to detect and react to local changes for power demand. Modern and future power supply system requires a distributed system for effective communication and management. Blockchain, a distributed technology, has been applied in many fields, e.g., cryptocurrency exchange, secure sharing of medical data, and personal identity security. Much research has been done on the application of blockchain to smart grid. While blockchain has many advantages, such as security and no interference from third parties, it also has inherent disadvantages, such as untrusted network environment, lacking data source privacy, and low network throughput.In this research, three systems are designed to tackle some of these problems in blockchain technology. In the first study, Information-Centric Blockchain Model, we focus on data privacy. In this model, the transactions created by nodes in the network are categorized into separate groups, such as billing transactions, power generation transactions, etc. In this model, all transactions are first encrypted by the corresponding pairs of asymmetric keys, which guarantees that only the intended receivers can see the data so that data confidentiality is preserved. Secondly, all transactions are sent on behalf of their groups, which hides the data sources to preserve the privacy. Our preliminary implementation verified the feasibility of the model, and our analysis demonstrates its effectiveness in securing data source privacy, increasing network throughput, and reducing storage usage. In the second study, we focus on increasing the network’s trustworthiness in an untrusted network environment. A reputation system is designed to evaluate all node’s behaviors. The reputation of a node is evaluated on its computing power, online time, defense ability, function, and service quality. The performance of a node will affect its reputation scores, and a node’s reputation scores will be used to assess its qualification, privileges, and job assignments. Our design is a relatively thorough, self-operated, and closed-loop system. Continuing evaluation of all node’s abilities and behaviors guarantees that only nodes with good scores are qualified to handle certain tasks. Thus, the reputation system helps enhance network security by preventing both internal and external attacks. Preliminary implementation and security analysis showed that the reputation model is feasible and enhances blockchain system’s security. In the third research, a countermeasure was designed for double spending. Double spending is one of the two most concerned security attacks in blockchain. In this study, one of the most reputable nodes was selected as detection node, which keeps checking for conflict transactions in two consecutive blocks. Upon a problematic transaction was discovered, two punishment transactions were created to punish the current attack behavior and to prevent it to happen in future. The experiment shows our design can detect the double spending effectively while using much less detection time and resources.

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Auto-scaling is a major way of minimizing the gap between the demand and the availability of the computing resources for the applications with dynamic workloads. Even though a lot of effort has been taken to address the requirement of auto-scaling for the distributed systems, most of the available solutions are application-specific and consider only on fulfilling the application level requirements. Today, with the pay-as-you-go model of cloud computing, many different price plans have been offered by the cloud providers which leads the resource price to become an important decision-making criterion at the time of auto-scaling. One major step is using the spot instances which are more advantageous in the aspect of cost for elasticity. However, using the spot instances for auto-scaling should be handled carefully to avoid its drawbacks since the spot instances can be terminated at any time by the infrastructure providers. Despite the fact that some cloud providers such as Amazon Web Services and Google Compute Engine have their own auto-scaling solutions, they do not follow the goal of cost-effectiveness. In this work, we introduce our auto-scaling solution that is targeted for middle-layers in-between the cloud and the application, such as Karamel. Our work combines the aspect of minimizing the cost of the deployment with maintaining the demand for the resources. Our solution is a rule-based system that is built on top of resource utilization metrics as a more general metric for workloads. Further, the machine terminations and the billing period of the instances are taken into account as the cloud source events. Different strategies such as window based profiling, dynamic event profiling, and optimized scale-in strategy have been used to achieve our main goal of providing a cost-effective auto-scaling solution for cloud-based deployments. With the help of our simulation methodology, we explore our parameter space to find the best values under different workloads. Moreover, our cloud-based experiments show that our solution performs much more economically compare to the available cloud-based auto-scaling solutions.

The information contained in this thesis explores ways to develop a habitat for human settlement on Mars. Currently, most designs for living on Mars focus primarily on survival and emphasize the technological aspects necessary for sustaining life. However, there is a lack of holistic consideration for what life on Mars would entail beyond mere survival. These existing designs are understandably geared towards astronauts who will spend only a few months on Mars. In contrast, this project is dedicated to envisioning the future of Mars settlement, aiming to support astronauts who intend to permanently live and establish communities on Mars, ultimately transforming them into Martians. The project adopts a human-centric approach by integrating biophilic design principles to enhance the well-being of future Martian inhabitants. It seeks to address potential psychological challenges that settlers on Mars may encounter, offering innovative solutions rooted in biophilia. This approach aims to create environments that foster connection with nature, promote mental health, and support overall quality of life for individuals living on Mars. Humans have evolved over millions of years to thrive on Earth, and many of our primal instincts are deeply rooted in our hunter-gatherer ancestry. Transitioning humans to live on another planet would uproot them from their natural environment, potentially depriving them of these primal instincts and causing psychological challenges. (Szocik, n.d.) This project aims to address these issues through architectural solutions. By designing habitats that consider and accommodate our innate instincts and connections to nature, we can mitigate the psychological impacts of living on a different planet. The goal is to create environments on Mars that resonate with our evolutionary heritage, fostering psychological well-being and adaptation in extra-terrestrial settlements. / Master of Architecture / This thesis looks at how to create a habitat for humans to live on Mars. Right now, most designs focus mainly on survival and the technology needed to sustain life. Most don't really consider what everyday life would be like beyond just staying alive. Most current designs are for astronauts who will only be on Mars for a few months. This project, however, imagines a future where people live on Mars permanently and form communities, essentially becoming Martians. The project uses a design method that focuses on human needs at a subconscious and psychological level. It incorporates biophilic design principles, which emphasize our connection to nature, to improve the well-being of future Martian inhabitants. This approach aims to address psychological challenges that settlers on Mars might face, offering innovative solutions based on biophilia. The goal is to create environments that foster a connection with nature, promote mental health, and support a good quality of life. Humans have evolved over millions of years to live on Earth, and many of our basic instincts are tied to our hunter-gatherer ancestors. Moving to another planet could take us away from our natural environment and cause psychological challenges. This project aims to tackle these issues through thoughtful architectural design. By creating habitats that consider our natural instincts and connections to nature, we can reduce the psychological impacts of living on Mars. The goal is to design environments that align with our evolutionary background, helping people adapt and thrive in extra-terrestrial settlements.

The purpose of this project is to improve parents experience in the NICU through design, technology, communication and storytelling. A series of shadowing appointments were conducted to gain empathy and a greater understanding of the environment the design would be in. Next 15 user interviews were conducted. The qualitative data was then analyzed and a needs analysis for the application was determined by identifying patterns in the qualitative data. The design then went through three phases of design, testing and iterating, before the final prototype was complete. This study found that design, technology and storytelling could improve communication and the experience of parents in the NICU. / Master of Fine Arts

Increasing computing power has been helping researchers understand many complex scientific problems. Scientific computing helps to model and visualize complex processes such as molecular modelling, medical imaging, astrophysics and space exploration by processing large set of data streams collected through sensors or cameras. This produces a massive amount of data which consume a large amount of processing and storage resources. Monitoring the data streams and filtering unwanted information will enable efficient use of the available resources. This thesis proposes a data-centric system that can monitor high-speed data streams in real-time. The proposed system provides a flexible environment where users can plug-in application-specific data monitoring algorithms. The Long Wavelength Array telescope (LWA) is an astronomical apparatus that works with high speed data streams, and the proposed data-centric platform is developed to evaluate FPGAs to implement data monitoring algorithms in LWA. The throughput of the data-centric system has been modeled and it is observed that the developed data-centric system can deliver a maximum throughput of 164 MB/s. / Master of Science

Yes / This paper considers recent field evidence to analyse what online public services citizens need, explores potential citizen subsidy of these specific services and investigates where resources should be invested in terms of media accessibility. We explore these from a citizen-centric affordability perspective within three ‘exemplar’ developing countries in sub-Saharan Africa. The World Bank and United Nations in particular promote initiatives under the ‘Information and Communication Technologies for Development’ (ICT4D) to stress the relevance of e-Government as a way to ensure development and reduce poverty. We adopt a ‘Contingency Value’ method to conceptually outline reported citizens willingness to pay for digital public services. Hence, our focus is mainly upon an empirical investigation through extensive fieldwork in the context of sub-Sahara Africa. A substantive survey was conducted in the respective cities of Addis Ababa (Ethiopia), Lagos (Nigeria) and Johannesburg (South Africa). The sample of citizens was drawn from each respective Chamber of Commerce database for Ethiopia and South Africa, and for Nigeria a purchased database of businesses, based on stratified random sampling. These were randomly identified from both sectors ensuring all locations were covered with a total sample size of 1,297 respondents. It was found, in particular, that citizens were willing to pay to be able to access digital public services and that amounts of fees they were willing to pay varied depending on what services they wish to access and what devices they use (PCs or mobile phones). / European Investment Bank under the EIB-Universities Research Action Programme