<div>This thesis consists of three chapters. In the first chapter, I investigate the effects of complexity in various voting systems on individual behavior in small group electoral competitions. Using a laboratory experiment, I observe individual behavior within one of three voting systems -- plurality, instant runoff voting (IRV), and score then automatic runoff (STAR). I then estimate subjects' behavior in three different models of bounded rationality. The estimated models are a model of Level-K thinking (Nagel, 1995), the Cognitive Hierarchy (CH) model (Camerer, et al. 2004), and a Quantal Response Equilibrium (QRE) (McKelvey and Palfrey 1995). I consistently find that more complex voting systems induce lower levels of strategic thinking. This implies that policy makers desiring more sincere voting behavior could potentially achieve this through voting systems with more complex strategy sets. Of the tested behavioral models, Level-K consistently fits observed data the best, implying subjects make decisions that combine of steps of thinking with random, utility maximizing, errors.</div><div><br></div><div>In the second chapter, I investigate the relationship between the mechanisms used to select leaders and both measures of group performance and leaders' ethical behavior. Using a laboratory experiment, we measure group performance in a group minimum effort task with a leader selected using one of three mechanisms: random, a competition task, and voting. After the group task, leaders must complete a task that asks them to behave honestly or dishonestly in questions related to the groups performance. We find that leaders have a large impact on group performance when compared to those groups without leaders. Evidence for which selection mechanism performs best in terms of group performance seems mixed. On measures of honesty, the strongest evidence seems to indicate that honesty is most positively impacted through a voting selection mechanism, which differences in ethical behavior between the random and competition selection treatments are negligible.</div><div><br></div><div><br></div><div>In the third chapter, I provide an investigation into the factors and conditions that drive "free riding" behavior in dynamic innovation contests. Starting from a dynamic innovation contest model from Halac, et al. (2017), I construct a two period dynamic innovation contest game. From there, I provide a theoretical background and derivation of mixed strategies that can be interpreted as an agent's degree to which they engage in free riding behavior, namely through allowing their opponent to exert effort in order to uncover information about an uncertain state of the world. I show certain conditions must be fulfilled in order to induce free riding in equilibrium, and also analytically show the impact of changing contest prize structures on the degree of free riding. I end this paper with an experimental design to test these various theoretical conclusions in a laboratory setting while also considering the behavioral observations recorded in studies investigating similar contest models and provide a plan to analyze the data collected by this laboratory experiment.</div><div><br></div><div>All data collected for this study consists of individual human subject data collected from laboratory experiments. Project procedures have been conducted in accordance with Purdue's internal review board approval and known consent from all participants was obtained.</div>

Stormwater is water that originates from snow or rainfall and that cannot naturally infiltrate the soil. When stormwater flows from hard surfaces it can transport different pollutants to watercourses. By measuring turbidity continuously and using the relationship between turbidity and pollutants the pollutant levels can be estimated. The aim of this study was partly to investigate the relationship between turbidity and phosphorus, metals and PAHs in stormwater in three catchment areas. This study also aimed to investigate how the distribution between dissolved and particulate bound concentrations of phosphorus and metals varied during different rain courses and at different catchment areas. The study was carried out in Uppsala and included continuous measurement of turbidity in three stormwater wells in three catchment areas. Seven samples were also taken at different precipitation occasions in both stormwater and in Fyrisån. In Svartbäcken there was a strong relationship between turbidity and phosphorus and metals. In Librobäck there was an indication that there was a strong relationship between turbidity and some metals and PAH:s. There was no relationship between turbidity and pollutants in Luthagen. Based on these samples, it is difficult to draw any conclusions about why the connections differed for certain pollutants and catchment areas. Due to the fact that the number of measuring points was too few the continuous measurement could not be used to estimate variations in pollution levels. To be able to use the continuous measurement, a longer sampling period and different precipitation occasions is needed. The continuous measurements were used to get an idea of when the samples were taken during the stormwater flow. The results also showed that all pollutants were mostly particulate bound for samples taken at the beginning of a precipitation occasion and with some precipitation during the sampling. For samples that did not take place in connection with stormwater runoff events, the distribution varied for the pollutants in the study. It has not been possible to see a clear trend for how the distribution between dissolved and particulate bound pollutants has varied between different catchment areas. / Dagvatten är vatten som uppkommer vid regn eller vid snösmältning och som inte kan infiltrera naturligt i marken. När dagvattnet avrinner ytligt på marken kan det föra med sig föroreningar till recipienten. Genom att mäta turbiditet kontinuerligt och utnyttja eventuella samband med föroreningar kan föroreningshalter i dagvatten uppskattas. Studien hade två huvudsakliga syften varav det ena var att undersöka samband mellan turbiditet och fosfor, metaller samt PAH:er i dagvatten i tre avrinningsområden. Detta för att se om sambanden kunde användas för att med hjälp av kontinuerlig mätning av turbiditet uppskatta föroreningshalter vid avrinningsområdena. Det andra syftet var att undersöka hur fördelningen mellan lösta och partikulärt bundna andelar fosfor och metaller varierade under olika regnförlopp och vid olika avrinningsområden.  Studien utfördes i Uppsala och innefattade delvis kontinuerlig mätning av turbiditet i tre dagvattenbrunnar i tre avrinningsområden. Det gjordes även sju stickprovtagningar vid olika nederbördstillfällen i både dagvatten och i Fyrisån. I Svartbäcken visade resultaten att det fanns starka samband mellan turbiditet och fosfor och metaller. I Librobäck fanns det en indikation för starka samband mellan turbiditet och fosfor samt vissa metaller och PAH:er. I Luthagen fanns det dock inga samband mellan turbiditet och undersökta föroreningarna. Utifrån dessa prover var det svårt att dra några slutsatser kring varför sambanden skilde sig åt för vissa föroreningar och avrinningsområden. På grund av att antalet mätpunkter var för få kunde inte den kontinuerliga mätningen användas för att uppskatta variationer av föroreningshalter. För att kunna använda den kontinuerliga mätningen behövs en längre provtagningsperiod med fler provtagningar.  Resultatet visade även att den partikulärt bundna andelen dominerade för alla föroreningar vid de provtagningar som togs i början på ett nederbördstillfälle och vid viss nederbörd. Vid provtagningar som utfördes senare under nederbördstillfället varierade fördelningen för de olika föroreningarna. Det har inte varit möjligt att se en tydlig trend för hur fördelningen mellan lösta och partikulärt bundna föroreningar varierade mellan olika avrinningsområden.

<p>This thesis studies non-nearest-neighbor random walks in random environments (RWRE) on the integers and on the d-dimensional integer lattic that are drawn in an i.i.d. way according to a Dirichlet distribution. We complete a characterization of recurrence and transience in a given direction for random walks in Dirichlet environments (RWDE) by proving directional recurrence in the case where the Dirichlet parameters are balanced and the annealed drift is zero. As a step toward this, we prove a 0-1 law for directional transience of i.i.d. RWRE on the 2-dimensional integer lattice with bounded jumps. Such a 0-1 law was proven by Zerner and Merkl for nearest-neighbor RWRE in 2001, and Zerner gave a simpler proof in 2007. We modify the latter argument to allow for bounded jumps. We then characterize ballisticity, or nonzero liiting velocity, of transienct RWDE on the integers. It turns out that ballisticity is controlled by two parameters, kappa0 and kappa1. The parameter kappa0, which controls finite traps, is known to characterize ballisticity for nearest-neighbor RWDE on the d-dimensional integer lattice for dimension d at least 3, where transient walks are ballistic if and only if kappa0 is greater than 1. The parameter kappa1, which controls large-scale backtracking, is known to characterize ballisticity for nearest-neighbor RWDE on the one-dimensional integer lattice, where transient walks are ballistic if and only if the absolute value of kappa1 is greater than 1. We show that in our model, transient walks are ballistic if and only if both parameters are greater than 1. Our characterization is thus a mixture of known characterizations of ballisticity for nearest-neighbor one-dimensional and higher-dimensional cases. We also prove more detailed theorems that help us better understand the phenomena affecting ballisticity.</p>

Abstract in English / In this dissertation we apply linear evolution equations to the Newtonian derivative, Caputo time fractional derivative and $-time fractional derivative. It is notable that the most utilized fractional order derivatives for modelling true life challenges are Riemann- Liouville and Caputo fractional derivatives, however these fractional derivatives have the same weakness of not satisfying the chain rule, which is one of the most important elements of the match asymptotic method [2, 3, 16]. Furthermore the classical bounded perturbation theorem associated with Riemann-Liouville and Caputo fractional derivatives has con rmed not to be in general truthful for these models, particularly for solution operators of evolution systems of a derivative with fractional parameter ' that is less than one (0 < ' < 1) [29]. To solve this problem, we introduce the derivative with new parameter, which is de ned as a local derivative but has a fractional order called $-derivative and apply this derivative to linear evolution equation and to support what we have done in the theory, we utilize application to population dynamics and we provide the numerical simulations for particular cases. / Mathematical Sciences / M.Sc. (Applied Mathematics)

Alla företag har – från tid till annan – någon form av investeringar i sin verksamhet. För att utvärdera olika investeringsalternativ används investeringskalkyleringar, men de bakomlig-gande antaganden som görs vid dessa kalkyler är präglade av osäkerhet då ingen kan sia om framtidens utfall. Ett verktyg som kan användas för att hantera denna osäkerhet är känslighets-analys. Det finns många studier gjorda om känslighetsanalyser, men nästan alla följer en rationell an-sats och tar sällan hänsyn till den begränsade rationella människan som står bakom analyserna. Syftet med denna studie är att analysera hur företag använder sig av känslighetsanalys i sam-band med investeringsbeslut, oavsett om de förhåller sig till den rationella ansatsen eller inte. Studien har därför genomförts med intervjuer för att kunna uppnå detta syfte. Studien visar på att det finns viktiga faktorer som gör att känslighetsanalysens roll och använ-dande inför investeringsbeslut skiljer sig åt i de intervjuer vi gjort. Faktorerna som denna studie har tagit hänsyn till är hur ägarstrukturen ser ut, vilka typer av investeringar som görs och organisationens tolkningsprocess av omgivningen. Genom vår analysmodell hoppas vi kunna visa på varför behovet och utförandet av känslighetsanalysen ser ut som det gör, men även ge en förståelse för varför den skiljer sig åt mellan olika företag. / All companies have some form of investment in their business. To evaluate different invest-ment options, they will use some form of capital budgeting techniques. However, the underly-ing assumptions made in these calculations are characterized by uncertainty, as no one can predict the outcome of the future. One tool that can be used to deal with this uncertainty is sensitivity analysis. There have been many studies done on the subject of sensitivity analysis. But almost all of them follow a rational approach and rarely consider the limited rational person behind these analyses. The purpose of this study is to analyse how companies use sensitivity analysis for investment decisions, regardless of whether they relate to the rational approach or not. This study was therefore conducted with interviews to be able to achieve this purpose. This study shows that there are important factors that change the sensitivity analysis purpose and how it is used for investments decisions in the interviews that we have done. The factors this study will take into account are company structures, types of investments and how organ-izations manage their interpretation process of their environment. Through our analysis model we hope to show why the need and implementation of sensitivity analysis looks the way it does and provide an understanding of why it differs between companies.

This thesis deals with the application of bounded model checking method for self-healing assurance of concurrency related problems. The self-healing is currently interested in the Java programming language. Therefore, it concetrate mainly on the model checker Java PathFinder which is built for handling Java programs. The verification method is implemented like the Record&Replay trace strategy for navigation through a state space and performance bounded model checking from reached state through the use of Record&Replay trace strategy. Java PathFinder was extended by new moduls and interfaces in order to perform the bounded model checking for self-healing assurance. Bounded model checking is applied at the neighbourhood of self-healing.

Social tillit är en central faktor i ett välfungerande samhälle och skapar förutsättningar för ekonomisktillväxt och sänkta transaktionskostnader. Att förstå vilka komponenter som kan bidra till nedbrytning avsocial tillit har därför stor betydelse för att kunna påverka samhällsutvecklingen. Syftet med denna uppsats är att identifiera och analysera drivkrafter och mekanismer som kan bryta ned social tillit i Sverige. En del forskare, däribland Robert Putnam, pekar på att etnisk mångfald på kort sikt kan bryta ned tillit. För att besvara uppsatsens syfte består studien av tre steg. Först identifieras tre komplikationer samt teser som utgör grunden för vår analysmodell. Dessa är modern informationsteknologi kan sprida misstro, identitet och polariserande drivkrafter kan styra individer att inte lita på andra samt begränsad rationalitet kan främja nedbrytningen av social tillit. Därefter genomfördes en omfattande litteraturstudie. Arbetet avslutades med en kvalitativ studie med sju semistrukturerade intervjuer där forskare och professorer fick granska den analysmodell som identifierats i studiens första steg. Komplikationerna analyseras med utgångspunkt i spelteorins förtroendespel. Även ett köns- ochgenusperspektiv inkluderas i analysen för att ta hänsyn till jämställdhetens centrala roll för ett fungerande högtillitssamhälle. Uppsatsen är explorativ och undersöker komplikationer som inte tidigare forskats kring. Därför önskade vi få kunskapsbidrag från professorer och forskare från olika discipliner för att skapa en helhetsbild av komplikationernas relevans för nedbrytningen av social tillit. Studien pekar på ett fortsatt högt och stabilt tillitsläge i Sverige och utöver komplikationerna visar studien att ekonomisk ojämlikhet och brist på gemenskap kan bidra till nerbrytning av social tillit. Denna hypotesgenererande uppsats ger upphov till tre hypoteser för fortsatt forskning. Att identitet och polariserande drivkrafter direkt kan förklara nedbrytning av social tillit genom att styra individer att inte lita på andra. Att modern informationsteknologi och begränsad rationalitet indirekt kan förklara nedbrytning av social tillit genom att sprida misstro respektive främja nedbrytningen. Att Putnams tes endast ger en förenklad bild av verkligheten och att etnisk mångfald inte ärdet största hotet för nedbrytning av social tillit. / Social trust is a key factor in a prosperous society and creates prerequisites for economic growth and reduced transaction costs. It is of significant value to understand which components contribute to the decomposition of social trust in order to impact social development. The purpose of this essay is toidentify and analyze forces and mechanisms that could decompose social trust in Sweden. Some researchers, including Robert Putnam, indicate that ethnic diversity could decompose trust in the short run. To answer the purpose of this study, the study consists of three stages. Three complications as well as theses were first chosen to create our analytical model. These are, that modern information technology could disseminate mistrust, that identity and polarizing forces could steer individuals not to trust others and that bounded rationality could promote the decomposition of social trust. After this stage, an extensive literature study was conducted. Lastly, a qualitative study with seven semi-structured interviews took place where professors and researchers were asked to review the analytical model that was conducted in the first stage of the study. The complications are analyzed from a game theoretic- and gender perspective. The study is explorative and examines complications that have not previously been examined or researched. As of this, we wish to gather knowledge from professors and researchers from different disciplines to create a holistic view of the complication's relevance on the decomposition of social trust. The study indicates a continuously high and stable state of trust in Sweden and, beyond the complications, the study shows that economic inequality and lack of community can contribute to the decomposition of social trust. This hypothesis generating essay originates three hypotheses for further research. That identity and polarizing forces could directly explain the decomposition of social trust by disseminating individuals not to trust others. That modern information technology and bounded rationality could indirectly explain the decomposition of social trust by steering mistrust respectively promoting the decomposition. That Putnam ́s thesis gives a simplified view of reality, and that ethnic diversity is not themost significant threat for the decomposition of social trust.

Couette, pipe, channel, and zero-pressure gradient (ZPG) turbulent boundary layer (TBL) flows have classically been considered as canonical wall-bounded turbulent flows since their near-wall behavior is generally considered to be universal, i.e. invariant of the flow case and the Reynolds number. Nevertheless, the idea that large-scale motions, being dominant in regions further away from the wall, might interact with and influence small-scale fluctuations close to the wall has not been disregarded. This view was mainly motivated due to the observed failure of collapse of the Reynolds normal stresses in viscous scaling. While this top-down influence has been studied extensively over the last decade, the idea of a bottom-up influence (backward energy transfer) is less examined. One exception was the recent experimental work on a Couette flow by Kawata, T. &amp; Alfredsson, P. H. (Phys. Rev. Lett. 120, 244501, 2018). In the present work, a spectral representation of the Reynolds Stress transport equation is used to perform a scale-by-scale analysis of the terms in the equation. Two flow cases were studied: first, a Direct Numerical Simulation (DNS) of a Couette flow at a similar Reynolds number as Kawata and Alfredsson. The Reynolds number was ReT = 120, viscosity v. Second, a Large Eddy Simulation (LES) of a ZPG TBL at ReT = 730, 1270, and 2400. For both cases the classic interscale transport or turbulent kinetic energy was observed. However, also an inverse interscale transport of Reynolds shear stress was observed for both cases.

No description available.

<p>We study the effect of minute perturbations by using blowing jets at upstream and bio-inspired micro denticles on turbulence large-scale motions which are observed to be crucial in controlling heat transfer, noise and drag reduction. This work is divided into two phases. In first phase, we studied the effect of blowing perturbations at upstream on large-scale motions and associated co?herent vortical structures which are crucial in enhancing heat transfer by promoting mixing. The second phase is focused on impact of flow dynamics in preventing the biofouling using micro bioinspired structures and the importance of flow regime in designing the antifouling coating us?ing bioinspired structures is demonstrated, and subsequently, separation bubble dynamics and its characterization is carried out for a transonic channel imposed with pressure gradient to further expand our thesis outcomes to utilize micro bioinspired structures in aerospace applications, noise reduction, and to delay separation.</p> <p><br></p> <p>Extensive studies were focused on the importance of large-scale motions (LSM) and their con?tribution to TKE and turbulence mixing. Although there are studies focusing on the λ2 coherent vortical structures and large-scale motions separately, there are no studies addressing the control?ling using upstream perturbations on the large-scale motions and their associated λ2 vortices. In the first phase of our studies, we used the DNS data of channel flow for Reτ = 394 generated using in-house code. In these simulations, we created blowing perturbations using spanwise jets of low blowing ratio, 0.2, placed at upstream. The spatial large-scale motions are extracted using a a novel 3D adaptive Gaussian filtering technique developed based on Lee and Sung [1] for turbulent pipe flows. POD is used to extract the energetic large-scale motions and coherent vortical structures are extracted using λ2-criterion for its efficiency in educing coherent structures in cross flow jets. The results show that the upstream perturbations enhance streamwise heat flux via energetic LSM and also create a secondary peak of scalar production in the log-layer showing that the perturbations alter LSMs to enhance the heat transfer. Filtered large-scale field from Gaussian filtering technique have an integral length scale greater than 2h (where h is channel half-height) are used to obtain λ2 vortices. The resulted λ2 vortices are of ring-type and have higher signature of temperature than their counterpart. The pre-multiplied spectra shows that the upstream perturbations can excite the large-scale wave-numbers which are in the same order as the jet diameter and spacing between them. Simulations show the presence of secondary peak in the log-layer and increased turbulence production which are eminent of large-scales. Furthermore, our results suggest that jet spacing and diameter are crucial in exciting large-scale field to control turbulent flows.</p> <p><br></p> <p>Evans, Hamed, Gorumlu, et al. [2] modeled the denticles present on Mako shark skin into a diverging micro-pillars. They conducted experimental studies in a water tunnel using these on the back of airfoil exposed to an adverse pressure gradient flow. They observed that presence of these pillars reduced the re-circulation bubble (form drag) by 50%. They proposed a blowing and suction type mechanism by which the micro pillars interact with the boundary layer. However, the details of underlying interfacial mechanism is not completely understood. The unique impact of flow conditions on anti-biofouling and the corresponding mechanisms for the first time is illustrated. We employed commercially available bioinspired structures as micro-diverging pillars making it feasible to apply in real life. We demonstrated the underlying mechanism by which bio?inspired structures are responsible for anti-biofouling. To study the pressure gradient effects on the separation under transonic conditions, we performed direct numerical simulations (DNS) in a non?equilibrium flow created by a sinsuoidal contraction and also, we quantified the separation length,</p> <p>detachment, and attachment points of separation bubble imposed with various pressure gradients and their variation in the transonic and subsonic regimes. We noticed that the resultant shear at the attachement led to the enhancement of coherent structures which are extended into the outer layer under transonic flow which is quite different than the subsonic flow.</p>