Smart contracts are digital agreements stored and executed on a blockchain. With smart contracts, multiple parties can enter into an agreement whose correct execution is guaranteed by the underlying blockchain. However, there is no inherent way for smart contracts to access data APIs external to the blockchain they reside on, which is needed in order to expand their usefulness. This thesis investigates two approaches of feeding data to a smart contract on the Ethereum blockchain, with regard to the performance metrics gas cost, block delay, and network latency. The investigation is set in the context of train travel where the time of arrival of a train at its destination is retrieved to the smart contract. Receiving and aggregating submissions from varying numbers of passengers is compared to retrieving this data from the dedicated open API provided by Trafikverket using the Chainlink framework. Through experiments, involving issuing transactions and monitoring them, it was found that in the case of passenger submissions with aggregation the gas costs had a linear relationship to the amount of passengers submitting data. Compared to lower amounts, the block delay for passenger submissions started seeing an increase at 100 to 300 submissions whereas it was more or less constant for aggregations. Furthermore, there was no noticeable trend for increase in network delay with increase of submissions. Conclusively, with regard to all performance metrics, it was found that in all cases involving more than five passengers it was cheaper to use Chainlink to fetch data from Trafikverket.

Denna uppsats syfte är att synliggöra de problem som orsakas av dagenspantsättningsförfarande av bostadsrätter och att undersöka om blockkedjor kan vara en lämpligteknik att använda till ett framtida bostadsregistersystem och därmed komma till rätta meddessa problem. Grunden till problemen ligger i att proceduren för att pantsätta en bostadsrättinte är lika rättssäker som när en fastighet pantsätts. Hur själva pantsättningen av fast egendomoch lös egendom går till skiljer sig radikalt åt då det finns tydliga krav på hur förfarandet skagå till för fast egendom. Samt att det finns en speciell inskrivningsmyndighet för fastigheter,Lantmäteriet som ansvarar för detta. För bostadsrätter finns däremot ingen myndighet utan detåligger bostadsrättsföreningarnas styrelser att ansvara för att inskrivningen av panten sker. Detgör att det alltför ofta saknas eller finns felaktiga pantnoteringar i lägenhetsförteckningarnavilket kan orsaka stora problem för flera parter.Under 2016 fick Lantmäteriet i uppdrag av den svenska regeringen att undersöka möjligheternamed att använda blockkedjor för fastighetsöverlåtelser och pantsättningsinskrivningar.Projektet har blivit internationellt uppmärksammat och Sverige ses som en pionjär på området.Detta pilotprojekt tillsammans med den uppmärksammade Bostadsrättspantsättningsdomen T2106-17 från Svea Hovrätt i Stockholm från 2018 är inspirationskällan till denna uppsatsfrågeställningar och syfte. Hovrättsdomen fastställdes i högsta domstolen i Stockholm den 8mars 2019, mål nr T 1559-18.Uppsatsens slutsats är att det pantsättningssystem som idag används är föråldrat och behövermoderniseras och samordnas av en ansvarig enhet. Studien visar även på att blockkedjeteknikmycket väl kan vara lämplig att använda för ett framtida bostadsrättsregister och vidpantsättningsförfarande till följd av sin säkerhet, transparens och förkortade ledtider. / The purpose of this essay is to highlight the problems caused by the current pledging procedureof tenant-owned apartments and to investigate whether blockchains can be a suitabletechnology to use for a future apartment register system and thus overcome these problems.The reason for the problems lies in the fact that the procedure for pledging a tenant-ownedapartment is not as legally secure as when a property is pledged. How the actual pledging ofproperty and pledging of tenant-owned apartment differ greatly since there are clearrequirements for pledging of the property but not for the tenant-owned apartments.Lantmäteriet is the authority in Sweden that is responsible for the land register and themortgage register. For tenant-owned apartments on the other hand there is no authority. Theresponsibility for the registration of the mortgage lies on the tenant-owner associations boards.This means that too often there is missing or incorrect mortgage listings in the apartmentlistings, which can cause major problems for several parties.In 2016, Lantmäteriet were commissioned by the Swedish government to investigate thepossibilities of using blockchains for real estate transfers and pledge registrations. The projecthas become internationally recognized and Sweden is seen as a pioneer in the field. This pilotproject together with the court judgement, T 2106-17, which is the source of inspiration for thisessay's issues and purpose. This court judgement was established by the supreme court, casenumber T 1559-18.The conclusion of the thesis is that the pledging system that is used today is obsolete and needsto be modernized and coordinated by a centralized unit within the government. Blockchaintechnology could be a suitable solution for a future tenant-owned apartment register becauseof its transparency, security and reduction in lead times.

The digital technologies advances are growing day per day, many of them are here to give us a new perspective and help us to do many things productively and efficiently. In the last years, there is considerable debate throughout how we can implement the new technologies and how they will transform the use of intellectual property rights. In this paper, we aboard this issue from the perspective of the copyrights. Many years ago, when platforms like Spotify or Apple Music came to this world, many artists and consumers were excited. Many people that were involved in the music industry saw this as a new way to reach a global market, fight piracy, and receive many economic benefits. For the consumers, the implementation of digital platforms was a new way to discover new artists and a new way to enjoy music. In the case of consumers, many of them are still thinking the same, but what about the rightsholders? For example, there is a lot of trendy artists that it is not possible to find in Spotify due to the skepticism about how beneficial it can be this kind of technology. This work looks at how beneficial it can be to the use of blockchain technology due to make a better industry that can be profitable again for the artist.

Purchase management of medical supplies is a critical and important process that affects the services provision quality. Nonetheless, it is facing a growing pressure to provide visibility and traceability of the purchase, to reduce fraud, to improve flexibility and to ensure communication between everyone involved. Currently, private health institutions in Peru choose to implant different software products within the same company with restricted visibility access to other concerned parties and based on information from a single source. A new alternative is Blockchain technology, since it provides a single source of shared truth to all participants and ensures that the information cannot be altered, thus offering high levels of transparency that, together with IoT technology, creates not only visibility about where things are, but also traceability, showing the current state of things. / Revisón por pares

Indiana University-Purdue University Indianapolis (IUPUI) / Combining rooftop solar with energy storage for off-grid residential operation is restrictively expensive. Historically, operating off-grid requires an 'isolated self-consumption' operating strategy where any excess generation is wasted and to ensure reliability you must install costly, polluting generators or a large amount of energy storage. With the advent of Blockchain technology residents can come together and establish transactive microgrids which have two possible operating strategies: Centralized Energy Sharing (CES) and Interconnected Energy Sharing (IES). The CES strategy proposes that all systems combine their photovoltaic (PV) generation and energy storage systems (ESS) to meet their loads. IES strategy establishes an energy trading system between stand-alone systems which allows buying energy when battery capacity is empty and selling energy when battery capacity is full. Transactive microgrids have been investigated analytically by several sources, none of which consider year-round off-grid operation. A simulation tool was developed through MATLAB for comparing the three operating strategies: isolated self-consumption, CES, and IES. This simulation tool could easily be incorporated into existing software such as HOMER. The effect of several variables on total cost was tested including interconnection type, initial charge, load variability, starting month, number of stand-alone systems, geographic location, and required reliability. It was found that the CES strategy improves initial cost by 7\% to 10\% compared to the baseline (isolated self-consumption) and IES cases in every simulation. The IES case consistently saved money compared to the baseline, just by a very small amount (less than 1\%). Initial charge was investigated for March, July, and November and was only found to have an effect in November. More research should be done to show the effect of initial charge for every month of the year. Load variability had inconsistent results between the two geographic locations studied, Indianapolis and San Antonio. This result would be improved with an improved load simulation which includes peak shifting. The number of systems did not have a demonstrable effect, giving the same cost whether there were 2 systems or 50 involved in the trading strategies. It may be that only one other system is necessary to receive the benefits from a transactive microgrid. Geographic locations studied (Indianapolis, Indiana; Phoenix, Arizona; Little Rock, Arkansas; and Erie, Pennsylvania) showed a large effect on the total cost with Phoenix being considerably cheaper than any other location and Erie having the highest cost. This result was expected due to each geographic location's load and solar radiation profiles. Required reliability showed a consistent and predictable effect with cost going down as the requirement relaxed and more hours of outage were allowed. In order to accomplish off-grid operation with favorable economics it is likely that a system will need to reduce its reliability requirement, adopt energy saving consumption habits, choose a favorable geographic location, and either establish a transactive microgrid or include secondary energy generation and/or storage.

Indiana University-Purdue University Indianapolis (IUPUI) / The advancement in technology has revolutionized the role of software in recent years. Software usage is practically found in all areas of the industry and has become a prime factor in the overall working of the companies. Simultaneously with an increase in the utilization of software, the software quality assurance parameters have become more crucial and complex. Currently the quality measurement approaches, standards, and models that are applied in the software industry are extremely divergent. Many a time the correct approach will wind up to be a combination of di erent concepts and techniques from di erent software assurance approaches [1]. Thus, having a platform that provides a single workspace for incorporating multiple software quality assurance approaches will ease the overall software quality process. In this thesis we have proposed a theoretical framework for distributed software quality assurance, which will be able to continuously monitor a source code repository; create a snapshot of the system for a given commit (both past and present); the snapshot can be used to create a multi-granular blockchain of the system and its metrics (i.e.,metadata) which we believe will let the tool developers and vendors participate continuously in assuring quality and security of systems and in the process be accessible when required while being rewarded for their services.

Syftet med uppsatsen är att kartlägga användningsområden för blockkedjeteknologin imusikindustrin i dagsläget [2021]. Arbetet är en kvalitativ studie med fokus påblockkedjans användningsområden i musikindustrin. Som metod användsenkätundersökning riktad åt personer med anknytning till antingen blockkedjeteknologieller musikindustrin eller både och. Verksamhetsanalys av relevanta organisationerkompletterar enkätstudien. Resultatet analyseras med koppling till Lars-Erik Gaddesförändringsdimensioner samt musikindustrins tre kärnindustrier. I mitt resultat har jagkommit fram till att blockkedjeteknologin är tydligast i den inspelade musikindustrinoch musiklicensindustrin. Blockkedjans anlag för dataintegritet, förtroende och säkerhetär en klar fördel, medan dess komplexitet är en nackdel för konsumenter. Ytterligareanalys med hjälp av Gaddes förändringsdimensioner visar att blockkedjeteknologin ären synlig och aktiv aktör i alla tre förändringsdimensioner i olika utsträckning.Påtagligast är blockkedjeteknologin i aktivitetsdimensionen och resursdimensionen.

Masters of Science / With the development of information and network technologies, Electronic Health Records (EHRs) management system has gained wide spread application in managing medical records. One of the major challenges of EHRs is the independent nature of medical institutions. This non-collaborative nature puts a significant barrier between patients, doctors, medical researchers and medical data. Moreover, unlike the unique and strong anti-tampering nature of traditional paper-based records, electronic health records stored in centralization database are vulnerable to risks from network attacks, forgery and tampering. In view of the data sharing difficulties and information security problems commonly found in existing EHRs, this dissertation designs and develops a credible Blockchain-based electronic health records (CB-EHRs) management system. To improve security, the proposed system combines digital signature (using MD5 and RSA) with Role-Based Access Control (RBAC). The advantages of these are strong anti-tampering, high stability, high security, low cost, and easy implementation. To test the efficacy of the system, implementation was done using Java web programming technology. Tests were carried out to determine the efficiency of the Delegated Byzantine Fault Tolerance (dBFT) consensus algorithm, functionality of the RBAC mechanism and the various system modules. Results obtained show that the system can manage and share EHRs safely and effectively. The expectation of the author is that the output of this research would foster the development and adaptation of EHRs management system.

Bakgrund/Problem Blockchain är ett tämligen nytt fenomen inom revision. I tidigare forskning går det att läsa om blockchain som ett nytt fenomen som kommer hjälpa revisorn att effektivisera och diversifiera sitt arbete. Andra forskare menar på att blockchain kan helt tar över professionen. De flesta forskare ser det från ett mer kritiskt perspektiv och menar på att revisorn kommer ha fortsatt stor roll i samhället. Syfte Studiens syfte är att skapa ökad förståelse för blockchain och hur den påverkar revisorsprofessionen. Studien bidrar till diskussionen om blockchain kan anses som ett hot eller en möjlighet för revisorsprofessionen. Metod I denna studie används en kvalitativ metod med en litteraturöversikt som grund.Data och kunskap kring ämnet samlas först in på ett explorativt och induktiv sätt och analyseras genom en tematisk analys för att identifiera mönster och ge oss en holistiskt vy över ämnet. Sedan utförs strukturerade sökningar av de stora teman som genererades av den tematiska analysen. Slutsats Sammanfattningsvis kom studien fram till att blockchain, rent teoretiskt, har potential till att helt ta över revisorsprofessionen. Det återstår dock många utmaningar som fortfarande behöver lösas för att detta ska bli verklighet. Implementeringen av blockchain förväntas effektivisera och förändra revisornsarbete och sätta högre krav på en mer teknisk utbildning. Vilket kommer att styrka revisorn som en profession enligt professionsteorin.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第24151号 / 情博第799号 / 新制||情||135(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 伊藤 孝行, 教授 吉川 正俊, 教授 緒方 広明, 特定准教授 LIN Donghui / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM