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We present an Ethash-based blockchain relay that utilizes Off-Chain Computation (OCC) to validate block headers on-chain. Current work compromises on fundamental ideas of the blockchain concept: they either require a centralized entity, require a centralized Trusted Third Party (TTP) or are built on economic assumptions. That way, they try to circumvent the on-chain cost-heavy Ethash computation. We utilize Zero Knowledge Proofs (ZKPs) to outsource the Ethash validation to an Off-Chain Computation Framework (OCCF) and only verify the validity of the OCC on-chain. The required dataset for the Ethash validation is inserted into a merkle tree for computational feasibility. Additionally, we validate multiple block headers in batches to further minimize on-chain costs. The on-chain costs of our batch validation mechanism are minimal and constant since only the proof of an OCC is verified on-chain. Through merkle proofs we enable the efficient inclusion of intermediary block headers for any submitted batch. The OCC is feasible on average consumer hardware specifications. Our prototype verifies 5 block headers in a single proof using the ZoKrates framework. Compared to current approaches we only use 3.3% of the gas costs resulting in a highly scalable alternative that is trustless, distributed and has no economic assumptions. For future work, we propose to distribute the computational overhead of computing Ethash inside a ZKP through an off-chain distribution module. This is because we rely on the concurrent execution of the OCC by at least 36 active participants to catch up with the current state of the relay’s blockchain. / Vi presenterar ett Ethash-baserat blockchain-relä som använder sig av Off-Chain Computation (OCC) att validera blockhuvuden i kedjan. Nuvarande arbete kompromissar med grundläggande idéer om blockchain-konceptet: de kräver antingen en centraliserad enhet, kräver en centraliserad Trusted Third Party (TTP) eller bygger på ekonomiska antaganden. På så sätt försöker de kringgå den kostnadstunga Ethash-beräkningen på kedjan. Vi använda Zero Knowledge Proof (ZKP) för att lägga ut Ethash-valideringen på en Off-Chain Computation Framework (OCCF) och verifiera endast giltigheten av OCC på kedjan. Den nödvändiga datamängden för Ethash-valideringen är infogas i ett merkleträd för beräkningsmöjlighet. Dessutom validerar vi flera blockhuvuden i omgångar för att ytterligare minimera kostnader i kedjan. På-kedjan kostnaderna för vår batchvalideringsmekanism är minimala och konstanta eftersom endast bevis på en OCC verifieras i kedjan. Genom merkle proofs möjliggör vi det effektiva inkludering av mellanliggande blockrubriker för alla inlämnade partier. OCC är genomförbart i genomsnitt konsumenthårdvaruspecifikationer. Vår prototyp verifierar 5 blockhuvuden i ett enda bevis med hjälp av ZoKrates-ramverket. Jämfört med nuvarande tillvägagångssätt vi använder bara 3,3% av gaskostnaderna vilket resulterar i ett mycket skalbart alternativ dvs förtroendelös, distribuerad och har inga ekonomiska antaganden. För framtida arbete, föreslår vi för att distribuera beräkningsoverheaden för beräkning av Ethash inuti en ZKP genom en distributionsmodul utanför kedjan. Detta beror på att vi skulle förlita oss på det samtidiga utförandet av OCC med minst 36 aktiva deltagare för att komma ikapp med det aktuella tillståndet för reläets blockkedja.

Background and Objectives: I investigated the use of sensitivity analyses in assessing statistical results or analytical approaches in three different statistical issues: (1) accounting for within-subject correlations in analyzing discrete choice data, (2) handling both-armed zero-event studies in meta-analyses for rare event outcomes, and (3) incorporating external information using Bayesian approach to estimate rare-event rates. Methods: Project 1: I empirically compared ten statistical models in analyzing correlated data from a discrete choice survey to elicit patient preference for colorectal cancer screening. Logistic and probit models with random-effects, generalized estimating equations or robust standard errors were applied to binary, multinomial or bivariate outcomes. Project 2: I investigated the impacts of including or excluding both-armed zero-event studies on pooled odds ratios for classical meta-analyses using simulated data. Five commonly used pooling methods: Peto, Mantel-Haenszel fixed/random effects and inverse variance fixed/random effects, were compared in terms of bias and precision. Project 3: I explored the use of Bayesian approach to incorporate external information through priors to verify, enhance or modify the study evidence. Three study scenarios were derived from previous studies to estimate inhibitor rates for hemophilia A patients treated with rAHF-PFM: 1) a single cohort of previously treated patients, 2) individual patient data meta-analysis, and 3) an previously unexplored patient population with limited data. Results and Conclusion: Project 1: When within-subject correlations were substantial, the results from different statistical models were inconsistent. Project 2: Including both-armed zero-event studies in meta-analyses increased biases for pooled odd ratios when true treatment effects existed. Project 3: Through priors, Bayesian approaches effectively incorporated different types of information to strengthen or broaden research evidence. Through this thesis I demonstrated that when analyzing complicated health research data, it was important to use sensitivity analyses to assess the robustness of analysis results or proper choice of statistical models. / Dissertation / Doctor of Philosophy (PhD)

Enterprises have focused on mechanisms to track insiders who may intentionally exceed and misuse their authorized access. However, there is an opportunity to understand why a trusted individual would want to exploit the trust and seek information with the intent of a malicious outcome. The detection of insider rogue or nefarious activities with information to which a user is already authorized is extremely difficult. Such insider threats require more deliberation than just considering it to be a problem that can be mitigated only by software or hardware enhancements. This research expects to help gain an early understanding of antecedents to such information behavior and provide an opportunity to develop approaches to address relevant character traits which could lead to a higher propensity of information misuse. This research proposes a theoretical framework and a conceptual research model to understand the antecedent factors to opportunistic information-seeking behavior of individuals. The study follows the three-essay format. Essay 1 explores the scholarly literature published about insider behavior to understand information behavior and proposes the theoretical framework for the study. PRISMA methodology was used for the thematic literature review. Essay 2 is a quantitative study of 424 university students surveyed using an online instrument for their responses to various scenarios in the context of academic dishonesty. Academic dishonesty is proposed as a proxy for information misuse. Essay 3 is a qualitative study engaging senior executives from various industries to understand their perspectives on the behavioral characteristics of individuals as they try to protect their corporate information from being misused and protect their reputation and liability from malicious use of their information.

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Climate change is progressing and society must act now to crea- te a future worth living in. This means changing the structure and behaviour of society. We will have to live together with nature again. The rebuilding of society to create this change creates new values and new ways of living in the future. Nature is changing because of our society‘s im- pact, so society must change to have less impact. The inspiration came from current trends that are happening. Groups like Greenpeace and Ex- tinction Rebellion are actively fighting for positive change to create a desirable future. On the other hand, people are changing more quietly by mo- ving to Eco Villages. It‘s a principle of living toge- ther in a community where minimising the impact on the environment is a top priority. But it also has other benefits, such as feeling more connec- ted to people and also feeling needed in life by doing a job for the community. By interviewing the eco-village Schloss Tempelhof in Germany, Igot a great overview of their living structure and their daily habits and needs. The biggest benefit for the people living in this community is that it creates a more meaningful life for them, which has a positive effect on everyone‘s happiness. To- day, more than 10,000 people live in Eco Villages.The process began by combing the research on current trends with past trends. In the past, punks in England challenged the mainstream and the sta- tus quo to make a positive impact on the world. They used fashion to stand out and shock. It hel- ped them to make a statement and it created a sense of obligation to dress like them to be part of that group. This was combined with an urgent need to be and live sustainably in the future. This com- bination created the persona of the Eco-Warrior. They fight to minimise human impact on the en- vironment and to achieve this they live together in ecovillages around the world. They have their local energy supply from wind, water and solar systems. They also grow their own seasonal food locally to maintain the food supply for the community. Furt- hermore, their fashion is used to show their belon- ging to a group and their beliefs. By creating a sub- culture and trend, more people could be attracted and feel the desire to join and be part of the change.Through the interview with Schloss Tempelhof, the vehicle requirements were identified and transla- ted into the future. Firstly, a vehicle must have a low impact on the environment. It has to be chan- geable by renewable and local energies, so being electric is advantageous for a small impact. Se- condly, it belongs to everyone in the community. The vehicle is parked at the community house to be available to everyone. The vehicle is used toge- ther and alone. So there is a relationship between comfort and footprint. If you are travelling alone, you do not want to feel guilty about driving a car that is too big, but if you are travelling together, you need a certain footprint. When driving alone, the driver sits comfortably in the back. When driving together, more people can sit on the front bench at an angle of 90 degrees to the direction of travel.Comfort is not a priority here, so more people sit closer together to keep the footprint small. The final need is to transport the fruit and vegetables pro- duced in the village to the neighbouring ecovillage.During the design process, several proposals were tried out in order to learn what worked and what did not. By creating different variations when imple- menting the identified needs and testing different sizes and proportions, the right proportion could be identified. By having serval design languages, the one that represented the Eco Warrior could also be found and developed further in the final proposal.The final proposal is a maximally reduced ve- hicle. Its open structure reduces the amount of materials used. The vehicle belongs to everyo- ne in the community, which is also represented by the open design. Through its multiple uses, a vehicle can be used as much as possible during its lifetime. In addition, the provocative aest- hetics bring together the pragmatic, utilitarian side with the rebellious side of the eco-warrior.

In 2003 a proclamation of Zero Tolerance towards sexual exploitation and abuse was made by Secretary General of United Nations Kofi Annan. The policy have been around for 20 years and so has the scandals how come? To find out Bacchis (2009) What’s the problem represented to be? approach to policy analysis was chosen to find out what strategies was applied to manage zero tolerance. The identified strategies are a systemwide implementation of the principles of conduct, a victim centred approach including procedures for reporting, and finally an accountability framework. Identified silences are how to change an organisational culture of tolerance, how to restore confidence and how to manage mixed messages.

Blockchains and Byzantine Fault Tolerance form the basis of decentralized currencies and ledgers, such as Bitcoin, Ripple, ZeroCash, and Ethereum. Several studies have focused on the currency aspects (e.g. authenticity, integrity, anonymity, and independence from central banks). In this thesis, we start by exploring to understand the security challenges and practical solutions for building simple payment networks. Then, we leverage such understanding in identifying the security challenges of more advanced and complex systems, in particular Futures Exchanges. The decentralization of a Futures Exchange poses new security challenges: i) the interplay between the security and economic viability, i.e. using the Price Discrimination Attack one can strategically force a trader out of the market when the trader's anonymity is broken; ii) the non-monotonic security behavior of an Exchange, i.e. an honest action may invalidate security evidence; and iii) the proportional burden requirement in the presence of high-frequency participants. Our goal is to enucleate the non-trivial design principles to resolve these challenges for building secure and distributed financial exchanges. We demonstrate the application of the distilled design principles by building a cryptographic reference for a futures exchange called FuturesMEX. We also simulate the performance of a FuturesMEX Proof-of-Concept with the Lean Hog market data obtained from the Thomson Reuters Ticks History DB. The results show that the obtained protocol is feasible for a low-frequency market such as Lean Hog. Furthermore, we investigate an extension of public markets, i.e. dark pools (private markets), in which the order book information is conditionally visible to some (financially) suitable parties. We propose a new cryptographic scheme called Witness Key Agreement that makes dark trading possible by probing prices and volumes based on committed financial information Finally, we evaluate the theoretical and practical performance of the new scheme; using a simulation of the dark pool data collected from the aggressive Bloomberg Tradebook, we obtain positive results.

Individual and societal desires for fossiluel independence are an increasingly popular goal. This research investigates residential geothermal space heating and cooling as a viable technical and financial alternative. The road to net-zero energy is then assessed, weighing the benefits and detriments to the consumer. First, the template for location-specific geothermal space heating and cooling is developed through a pilot analysis of a home in Memphis, Tennessee. A methodical process of soil investigation, prototype home characteristics, and financial incentives is designed. Expanding upon existing studies, accurate soil data is extracted from beneath the foundation of a specific address, rather than region-wide soil averages. This high level of precision allows the owner of a specific address to preview realistic results and develop truthful expectations. Payback period and system lifetimes savings are calculated using two methods. Second, the framework developed through the Memphis, Tennessee pilot home is used to investigate 11 additional cities across the continental United States. The increase in breadth uses a representative city from its respective climate zone. While each city within a single climate zone will vary from the representative city, a general climate performance can be determined. With each location’s soil properties and heating and cooling demands, the borefield design and heat pump system capacity is customized and applied for analysis. Using human interest surveys from previous energy projects, a climate is ultimately classified as viable or nonviable for geothermal heating and cooling. Finally, the increasingly popular net-zero energy building concept is explored through a complementary solar photovoltaic (PV) array to the geothermal system. An array capacity is sized and priced to offset the total facility energy use in each climate’s representative city. Once determined, the payback and lifetime savings values are calculated and the GHP + PV system results are compared to a baseline + PV system. From this, a system type is identified as the more viable option for each of the 12 climate zones. The final touch on this research is the introduction of the human perceptions toward environmentally friendly renewable energy in general and how it affects a consumer’s ultimate decision.

In this dissertation we have studied nearield phenomena in dipole radiation. We have studied first the energy flow patterns of the radiation emitted by an electric dipole located in between parallel mirrors. The field lines of the Poynting vector have intricate structures, including many singularities and vortices. For a dipole parallel to the mirror surfaces, vortices appear close to the dipole. Vortices are located where the magnetic field vanishes. Also, a radiating electric dipole near the joint of two orthogonal mirrors is considered, and also here we find numerous singularities and vortices in the energy flow patterns. We have also studied the current density in the mirrors. Next we have studied the reflection of radiation by and the transmission of radiation through an interface with an  -near-zero (ENZ) material. For p polarization, we find that the reflection coefficient is -1, and the transmission coefficient is zero for all angles of incidence. The transmitted electric field is evanescent and circularly polarized. The transmitted magnetic field is identically zero. For s polarization, the transmitted electric field is s polarized and the transmitted magnetic field is circularly polarized. The next topic was the study of the force exerted on the dipole by its own reflected field near an ENZ interface. We found that, under certain circumstances, it could be possible that the dipole would levitate in its reflected field. This levitation is brought about by evanescent reflected waves. Finally, power emission by an electric dipole near an interface was considered. We have derived expressions for the emitted power crossing an interface. The power splits in contributions from traveling and evanescent incident waves. We found that for an ENZ interface, only evanescent dipole waves penetrate the material, but there is no net power flow into the material.