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In today's society we need an emergency communication system to facilitate communication for when disaster strikes. Where the previous attempts only focused on the network communication and were missing a messaging capability between users. This thesis focused on using blockchain technologies and distributed technologies to validate if a messaging application could be built for a LoRaMesh network by using these technologies. This thesis uses the Design science method to create a design and a proof-of-concept messaging application based on the LoRaMesh protocols network constraints. The first step was to gather knowledge about Blockchain technologies and distributed technologies since these were found to be able to complement weaknesses of IoT protocols and their devices. This knowledge was then used to create a design which could then be used to create the proof-of-concept application and a controlled experiment used to validate the solution.  The controlled experiment was executed in two different iterations for a total of 430 test runs. From this controlled experiment quantitative data could be collected and then measured using the statistical analysis method linear regression analysis. The linear regression analysis was used to produce statistical data to validate the design and proof-of-concept application by controlling it against a standard p-value. The results and conclusions of this thesis contributed to new knowledge by showing how Blockchain technologies and distributed technologies can be used to complement each other. To gain a decentralized message application which can be used in an Emergency communication network based on the LoRaMesh protocols network constraints.

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This work first implements a prototype of the proof-of-location scheme Vouch in order for an evaluation to be conducted in a real-world environment. With simulations of the scheme showing promising results, the next step would be an evaluation of the schemes performance in the real-world. This report introduces the scheme and similar works in relation to implementation and evaluation. Method of implementation is presented followed by an evaluation. The evaluation focuses on detection accuracy of the scheme by investigating impacts of the inevitably arising staleness. Contributors of staleness are identified and their impacts on overall detection accuracy of Vouch are measured. With the prototype successfully implemented, measurements showed a trend in improving detection accuracy with higher proof update frequencies, reaching as high as 9̃5% in a high velocity environment. The results shows that the Vouch scheme not only gives promising results in simulation, but also in the real-world.

Syfte: Den aktuella studien är en metodstudie för att undersöka möjligheten att mäta förändringar i muskeltjocklek med ultraljud. Om detta fungerar kan metoden användas i studier som för närvarande undersöker om muskeltjocklek eller förändringar i muskeltjocklek vid användning är relaterade till orofacial smärta.Material och metod: Tjugotvå friska forskningsindivider undersöktes. Alla forskningsindivider svarade negativt på de tre screeningfrågorna för temporomandibulär dysfunktion. Ultraljudsundersökningen utfördes för att utvärdera massetermuskelns och temporalismuskeln tjocklek (tjockaste delen och på en standardiserad plats för varje muskel) bilateralt som ett surrogatmått för det totala muskelblodflödet i vila och under hopbitning före och efter en tuggövning. Individen skulle tugga tre smaklösa paraffintuggummi med en frekvens av 90 Hz (90 tugg per minut) under 5 minuter. Individen svarade också på tre frågor om muskelsmärta, trötthet och obehag före och efter tuggövningen.Resultat: Vid jämförelse av muskeltjockleken i vila kontra hopbitning, både före och efter tuggövningen, var resultaten att massetermuskeln är tjockare vid hopbitning än vid vila. Resultaten var signifikant för masseter men inte för den temporalis. Resultaten avseende NRS-skalorna, som visade en ökning i värde efter tuggövningen, var enligt den statistiska analysen signifikanta.Slutsats: Denna studie visar att bedömning av muskeltjocklek med ultraljud är möjlig för masseter eftersom metoden kan upptäcka skillnader mellan vila och hopbitning. / Aim: The current study is a proof-of-concept study to investigate the possibility to measure changes in muscle thickness with ultrasound. If this works, the methodology can be used in studies that are currently investigating whether muscle thickness or changes in muscle thickness in use are related to orofacial pain. Materials and method: Twentytwo healthy research individuals were examined. All of the research individuals answered negatively on the three screening questions for temporomandibular disorders. The ultrasound examination was performed to assess masseter and temporal muscle thickness (thickest part at one standardized location for each muscle) bilaterally as a surrogate measure of total muscle blood flow at rest and during clenching before and after a chewing exercise. The subject would chew three paraffin wax taste-less chewing gums at a frequency of 90 Hz (90 chews per minute) for 5.0 minutes. The subject also answered three questions about muscle pain, fatigue and discomfort before and after chewing. Result: When comparing the muscle thickness at rest versus clenching, both before and after the chewing exercise, the results were that the masseter muscle is thicker when clenching than at rest. The difference was significant for the masseter but not for the temporal muscle. The results obtained regarding the NRS-scales, which showed an increase in value after the chewing exercise was according to the statistical analysis significant. Conclusion: This study shows that assessment of muscle thickness with ultrasound is feasible for the masseter muscle since the method is capable of detecting differences between rest and clenching.

<p>Fully homomorphic encryption allows computations to be made on encrypted data without decryption, while preserving data integrity. This feature is desirable in a variety of applications such as banking, search engine and database querying, and some cloud computing services. Despite not knowing the plaintext content of the data, a remote server performing the computation would still be aware of the functions being applied to the data. To address the issue, this thesis proposes a method of encrypting circuits and executing encrypted instructions, by combining fully homomorphic encryption and digital logic theory. We use the classic RISC Archtecture as a foundation of our work, and the result of our algorithm is essentially an encrypted programming language, where a remote server is capable of executing program code that was written and encrypted by a local client.</p> / Master of Science (MS)

In this dissertation, we propose a computational approach using a resampling based permutation test as an alternative to MCP-Mod (a hybrid framework integrating the multiple comparison procedure and the modeling technique) and gMCP-Mod (generalized MCP-Mod) [11], [29] in the step of identifying significant dose-response signals via model selection. We name our proposed approach RMCP-Mod or gRMCP-Mod correspondingly. The RMCP-Mod/gRMCP-Mod transforms the drug dose comparisons into a dose-response model selection issue via multiple hypotheses testing, an area where not much extended researches have been done, and solve it using resampling based multiple testing procedures [38]. The proposed approach avoids the inclusion of the prior dose-response knowledge known as "guesstimates" used in the model selection step of the MCP-Mod/gMCP-Mod framework, and therefore reduces the uncertainty in the significant model identification. When a new drug is being developed to treat patients with a specified disease, one of the key steps is to discover an optimal drug dose or doses that would produce the desired clinical effect with an acceptable level of toxicity. In order to nd such a dose or doses (different doses may be able to produce the same or better clinical effect with similar acceptable toxicity), the underlying dose-response signals need to be identified and thoroughly examined through statistical analyses. A dose-response signal refers to the fact that a drug has different clinical effects at many quantitative dose levels. Statistically speaking, the dose-response signal is a numeric relationship curve (shape) between drug doses and the clinical effects in quantitative measures. It's often been a challenge to nd correct and accurate efficacy and/or safety dose-response signals that would best describe the dose-effect relationship in the drug development process via conventional statistical methods because the conventional methods tend to either focus on a fixed, small number of quantitative dosages or evaluate multiple pre-denied dose-response models without Type I error control. In searching for more efficient methods, a framework of combining both multiple comparisons procedure (MCP) and model-based (Mod) techniques acronymed MCP-Mod was developed by F. Bretz, J. C. Pinheiro, and M. Branson [11] to handle normally distributed, homoscedastic dose response observations. Subsequently, a generalized version of the MCP- Mod named gMCP-Mod which can additionally deal with binary, counts, or time-to-event dose-response data as well as repeated measurements over time was developed by J. C. Pinheiro, B. Bornkamp, E. Glimm and F. Bretz [29]. The MCP-Mod/gMCP-Mod uses the guesstimates" in the MCP step to pre-specify parameters of the candidate models; however, in situations where the prior knowledge of the dose-response information is difficult to obtain, the uncertainties could be introduced into the model selection process, impacting on the correctness of the model identification. Throughout the evaluation of its application to the hypothetical and real study examples as well as simulation comparisons to the MCP-Mod/gMCP-Mod, our proposed approach, RMCP-Mod/gRMCP-Mod seems a viable method that can be used in the practice with some further improvements and researches that are still needed in applications to broader dose-response data types. / Statistics

<p dir="ltr">Combinatorial graph theory is an essential tool in the design and analysis of cryptographic primitives such as Memory-Hard Functions (MHFs) and Proofs of Sequential Work (PoSWs). MHFs are used to design egalitarian Proofs of Work and to help protect low-entropy secrets such as user passwords against brute-force attacks in password hashing. A PoSW is a protocol for proving that one spent significant sequential computation work to validate some statement. PoSWs have many applications, including time-stamping, blockchain design, and universally verifiable CPU benchmarks. Prior work has used combinatorial properties of graphs to construct provably secure MHFs and PoSWs. However, some open problems still exist, such as improving security bounds for MHFs, finding approximation algorithms for measuring their memory hardness, and analyzing the post-quantum security of MHFs and PoSWs. This dissertation addresses these challenges in the security analysis of MHFs and PoSWs using combinatorial graph theory. </p><p dir="ltr">We first improve the understanding of the classical security of MHFs in the following ways. (1) We present improved security bounds for MHF candidates such as Argon2i and DRSample under plausible graph-theoretic conjectures. (2) We prove that it is Unique Games-hard to approximate the cumulative pebbling complexity of a directed acyclic graph, which is an important metric to understand the memory-hardness of data-independent MHFs. (3) We provide the first explicit construction of extremely depth-robust graphs with small indegree. Here, (extreme) depth-robustness is a crucial combinatorial tool to construct secure MHFs and PoSWs. (4) We build a new family of graphs that achieves better provable parameters for concrete depth-robustness.</p><p dir="ltr">Second, as we progress toward developing quantum computers, we initiate the post-quantum security analysis of MHFs and PoSWs. Specifically, we make the following contributions. (1) We introduce the parallel reversible pebbling game, which captures additional restrictions in quantum computing. We use combinatorial graph theory as a tool to analyze the space-time complexity and the cumulative pebbling complexity of MHF candidates such as Argon2i and DRSample in a reversible setting, which we call reversible space-time/cumulative pebbling cost, respectively. (2) We prove that the reversible cumulative pebbling cost is never too much larger than the classical cumulative pebbling cost, along with the separation result that, in some instances, the reversible cumulative pebbling cost is asymptotically larger than the classical one. (3) We prove that it is also Unique Games-hard to approximate the reversible cumulative pebbling cost of a directed acyclic graph. (4) Finally, we establish the post-quantum security of a PoSW from Cohen and Pietrzak (EUROCRYPT 2018) in the parallel quantum random oracle model by extending Zhandry's compressed oracle technique (CRYPTO 2019) and utilizing underlying combinatorial techniques of PoSWs.</p>

In this thesis we develop tools for carrying out computer assisted proof of the stability of traveling wave solutions of the spatially one-dimensional compressible Navier-Stokes equations with an ideal gas equation of state. In particular, we obtain rigorous, tight error bounds on a high-accuracy numerical approximation of the traveling wave profile for parameters corresponding to air, and we obtain rigorous representations in a neighborhood of positive and negative infinity of the solution to the first order ODE associated with linearizing the PDE equations about the traveling wave solution. We also develop supporting tools for rigorous verification of wave stability.

京都大学 / 0048 / 新制・論文博士 / 博士(情報学) / 乙第13184号 / 論情博第94号 / 新制||情||116(附属図書館) / (主査)教授 石田 亨, 教授 中村 佳正, 教授 岡部 寿男, 教授 岡本 龍明 / 学位規則第4条第2項該当 / Doctor of Informatics / Kyoto University / DFAM