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Blockchain is a decentralized and immutable append-only ledger. Smart contracts, the self-executing programs on blockchain, help build the Decentralized Finance (DeFi) markets. Front-running is the practice of benefiting from advanced knowledge of pending transactions. It impairs the fairness of DeFi ecosystem, leading to huge losses of honest participants. In this thesis, We present Flash Freezing Flash Boys (F3B), a blockchain framework that mitigates front-running with threshold cryptography. In F3B, transactions are encrypted with symmetric keys, which are collaboratively kept by a decentralized secret-management committee (SMC). Once the transactions are committed and immutable, the keys are reconstructed to execute the transactions. F3B hides the content of pending transactions so that adversaries cannot acquire information about them, thus mitigating frontrunning. Previous work using threshold encryption mitigates front-running with per-block encryption, which would fail when a transaction is not included in the expected future block. F3B solves this issue by adopting per-transaction encryption, ensuring that any uncommitted transaction remains encrypted and private, even when a huge network delay occurs. F3B is an execution layer front-running solution, meaning that it is independent of the consensus algorithms and compatible with existing blockchain networks and smart contracts. F3B is evaluated on a simulated Ethereum network, and proved to be a practical low-latency solution. F3B presents a negligible (0.026%) latency overhead with 128 SMC members, compared with the unprotected blockchain. / Blockchain är en decentraliserad och oföränderlig bilaga-endast reskontra. Smarta kontrakt, de självutförande programmen på blockchain, hjälper till att bygga decentraliserade finansmarknader (DeFi). Front-running är praktiken att dra nytta av avancerad kunskap av pågående transaktioner. Det försämrar rättvisan hos DeFi-ekosystemet, leder till enorma förluster av ärliga deltagare. I denna avhandling presenterar vi Flash Freezing Flash Boys (F3B), ett blockchain-ramverk som dämpar frontkörning med tröskelkryptografi. I F3B krypteras transaktioner med symmetriska nycklar, som hålls i samarbete av en decentraliserad hemlig förvaltningskommitté (SMC). När transaktionerna väl är genomförda och oföränderliga, nycklarna rekonstrueras för att utföra transaktionerna. F3B döljer innehållet i pågående transaktioner så att motståndare inte kan få information om dem, vilket minskar frontrunning. Tidigare arbete med tröskelkryptering minskar körning i förväg med kryptering per block, vilket skulle misslyckas när en transaktion inte ingår i det förväntade framtida blocket. F3B löser det här problemet genom att använda kryptering per transaktion, vilket säkerställer att alla oengagerade transaktioner förblir krypterade och privata, även när en enorm nätverksfördröjning inträffar. F3B är en exekveringslagers frontrunning lösning, vilket innebär att den är oberoende av konsensusalgoritmerna och kompatibel med befintliga blockchain-nätverk och smarta kontrakt. F3B utvärderas på ett simulerat Ethereum-nätverk och visade sig vara en praktisk lösning med låg latens. F3B presenterar en försumbar (0,026%) latensoverhead med 128 SMC-medlemmar, jämfört med den oskyddade blockkedjan.

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The main problems concerning birth of running injuries is their unclear ethiopathogenesis and high frequency. Injuries are often lined with forces affected on tread-down which have to be defused by running shoes. There are also opinions that currently used footwear can cause injuries on the contrary. This work explores impact of particular types of running shoes for influencing of stability. Methods: There are compared two groups of runners: minimalists and classic runners. Their stability is examined with help of posturography in three versions: barefoot, classic and minimalistic footwear. Thereafter there is analyzed relation among stability, used footwear, training usage and frequency of injuries. Results: Minimalists and classic runners have the same stability while they are barefoot. Usage of footwear does not cause significant deterioration of stability in any of groups. Nevertheless most of runners subjectively evaluate the variant of testing barefoot as the simplest. There is more frequent occurence of flat foot among classic runners in comparison with minimalists. Flat foot increases risk of formation injuries, on the contrary, regular compensation motion activity decreases this risk.

Sammanfattning   Syfte och frågeställningar Syftet med denna studie var att sammanställa kvalitet på och resultat av studier som undersökt om långdistanslöpning ger artros i höft-, knä- eller fotleder. Finns det vetenskaplig evidens för att långdistanslöpning ger artros i höft-, knä- eller fotleder? Vilka styrkor och svagheter har de studier som försökt utröna om samband finns mellan långdistanslöpning och artros i höft-, knä- eller fotleder?   Metod Sökning av litteratur utfördes i PubMed, CINAHL, Cochrane Library och PEDro. Detta resulterade i att tio artiklar inkluderades för närmare granskning och sammanställning. Utifrån artiklarnas sammantagna bevisvärde poängsattes och graderades artiklarna efter evidensnivå enligt Statens Beredning för medicinsk Utvärderings (SBU) granskningsmallar för kohortstudier med kontrollgrupper.   Resultat Endast en av tio studier visar ett positivt samband mellan långdistanslöpning och artros i höft-, knä- eller fotleder, i detta fall höftledsartros. Studierna har ingen tydlig och gemensam definition över vad långdistanslöpning är. De granskade studierna använder sig av olika mätmetoder för att bedöma leddegenerationen, både av självrapportering och av olika diagnostiska kriterier för artros. Alla studier har inslag av selektionsbias.   Slutsats En indikation på att det inte finns ett vetenskapligt stöd för att långdistanslöpning ger höft-, knä- eller fotledsartros hos människor. Studierna har brister i hantering av confounders och selektionsbias och bedöms vara av låg eller medelhög kvalitet. / Abstract   Aim The purpose of this study was to compile the quality and results of studies that examined if long-distance running gives osteoarthritis of the hip, knee or ankle joints. Is there scientific evidence that long-distance running gives osteoarthritis of the hip, knee or ankle? What strengths and weaknesses of the studies attempted to determine if the link between long-distance running and osteoarthritis of the hip, knee or ankle joints.   Method Search of the literature was performed in PubMed, CINAHL, Cochrane Library, and PEDro. This resulted in ten articles that were included for further review and compilation. Based on the articles combined probative value was scored and graded articles for level of evidence according to the National Council on Technology Evaluation (SBU) examination templates for cohort studies with control groups.   Results Only one of the ten studies showed a positive association between long distance running and osteoarthritis of the hip, knee or ankle joints, in this case hip joint. The studies have not a clear and common definition of what long-distance running is. The studies reviewed use different metrics to assess joint degeneration, both by self-report and of different diagnostic criteria for osteoarthritis. All studies have an element of selection bias.   Conclusion An indication that there is no scientific evidence that long-distance running gives hip, knee or ankle osteoarthritis in humans. The studies were inadequate handling of confounders and selection bias and judged to be of low or medium quality.

Research on athletes has shown that mental skills are an important component of being a successful athlete. The importance of these mental skills is seen in the number of athletes who have formally started training using mental skills training programmes (MST) according to the literature. The study of mental skills in South Africa lags behind other countries like USA, UK and Sweden. This particular study explored the use of mental skills by road running athletes. The study was conducted with six competitive marathon athletes. Semi-structured interviews were conducted as part of an elaborate qualitative methodology design. The data collected from these semi-structured interviews was analysed using thematic analysis. The results show that road running athletes use mental skills that include; mental rehearsal, planning, goal setting and self-talk. The athletes in this research showed the importance of mental skills and it is recommended that formal training in these mental skills will be highly beneficial not only to road running athletes but for all South African sports people in general

В диссертационном исследовании проведен конкурентный анализ рынка услуг школ бега в Екатеринбурге, выявлены проблемы и предложены пути их решения. Разработана услуга пробного занятия для внедрения в школе бега Foreverun. Предложенные в работе мероприятия позволяют познакомить потенциального клиента со школой бега, повысить уровень лояльности и доверия клиента. / The dissertation study analyses the market for running school services in Ekaterinburg, identifies problems and suggests ways to solve them. A trial lesson service was developed to be implemented in the Foreverun running school. The suggested activities allow to introduce a potential client to the running school, to increase the level of loyalty and trust on the side of a client.

Call number: LD2668 .T4 1985 W54 / Master of Science

Recently, one of the major problems in various countries is the management of complicated organisations to cope with the increasingly competitive marketplace. This problem can be solved using Enterprise Resource Planning (ERP) systems which can offer an integrated view of the whole business process within an organisation in real-time. However, those systems have complicated workflow, are costly to be analysed to manage the whole business process in those systems. Thus, Long Running Transaction (LRTs) models have been proposed as optimal solutions, which can be used to simplify the analysis of ERP systems workflow to manage the whole organiational process and ensure that completed transactions in a business process are not processed in any other process. Practically, LRTs models have various problems, such as the rollback and check-pointing activities. This led to the use of Communication Closed Layers (CCLs) for decomposing processes into layers to be analysed easily using sequential programs. Therefore, the purpose of this work is to develop an advanced approach to implement and analyse the workflow of an organisation in order to deal with failures in Long Running Transaction (LRTs) within Enterprise Resource Planning (ERP) systems using Communication Closed Layers (CCLs). Furthermore, it aims to examine the possible enhancements for the available methodology for ERP systems based on studying the LRT suitability and applicability to model the ERP workflows and offer simple and elegant constructs for implementing those complex and expensive ERP workflow systems. The implemented model in this thesis offers a solution for two main challenges; incompatibilities that result from the application of transitional transaction processing concepts to the ERP context and the complexity of ERP workflow. The first challenge is addressed based on offering new semantics to allow modelling of concepts, such as rollbacks and check-points through various constraints, while the second is addressed through the use of the Communication Closed Layer (CCL) approach. The implemented computational reconfigurable model of an ERP workflow system in this work is able to simulate real ERP workflow systems and allows obtaining more understanding of the use of ERP system in enterprise environments. Moreover, a case study is introduced to evaluate the application of the implemented model using three scenarios. The conducted evaluation stage explores the effectiveness of executable ERP computational models and offers a simple methodology that can be used to build those systems using novel approaches. Based on comparing the current model with two previous models, it can be concluded that the new model outperforms previous models based on benefiting from their features and solving their limitations which make them inappropriate to be used in the context of ERP workflow models.

Background: Running is one of the most popular branches of athletics. Running has several physiological benefits, such as a higher maximal oxygen consumption, increased muscle mass and reduced blood pressure. There have been plenty of discussions about what the most efficient running technique might be, should you use a short step length and a high step frequency or vice versa. It is generally known that you can increase your running speed by increasing your step frequency or your step length, and also both. However, maximal speed is achieved by increasing your step frequency rather than your step length. For endurance runners it is important to have a good running economy, because runners with a good running economy use less energy while running, and therefore require less oxygen than a runner with poor running economy. Previous research have not found any correlations between the length of the leg with step frequency or step length.  Aim: The aim of this study was to examine whether there are any significant correlations between the length of the leg in relation to the step frequency or the step length while running in different speeds.  Method: 15 trained males participated in this correlation study. All participants’ leg length were measured with a measuring tape. Three running trials, with the speeds of 12, 16 and 20 km/h were performed on a treadmill during 1 minute each. Between each trial the participants rested for 3 minutes. The trials were recorded with a video camera, and the participants individual step frequency, step length and heel or fore foot strike were collected. Persons coefficient of correlation test was used to analyze if there were any significant correlations between the length of the leg with step frequency and step length. Also a paired samples T test was performed to see if there was a significant increase between step frequency and step length with the speeds.  Result: There were no significant correlations (p>0,05) found between the length of the leg and the step frequency or the length of the leg and step length in any of the different speeds. The paired samples t-test showed a significant (p<0,001) increase in step frequency and step length with the different speeds.  Conclusion: In conclusion, according to the present study, there were no significant correlations found between the length of the leg with step frequency or step length, which is in consensus with previous research.  Therefore, it is not advisable to predict an individual’s step length based on their leg length. There are various factors involved in determining a person’s step length and step frequency, and this study showed that running speed is one important factor. This information may be useful for runners and their coaches to apply, so they avoid making interventions involving alternations in the runners step length based on their body dimensions, such as leg length.