This dissertation focuses on media coverage and public opinion about United States foreign policy during a time of national crisis. It seeks to better understand the nature of news content by exploring the concept of press independence through the lens of two theories of news media: indexing and echoing. Focusing on the current U.S. military engagement with the Islamic State of Iraq and the Levant (ISIL), the present study tracks media coverage between June 2014 and June 2015 across six distinct print and online news outlets. This content analysis reveals that the press offered limited criticism of policies, particularly early in the intervention. Print and online news media covered U.S. policy in similar fashion, each relying more on nongovernmental sources than on Washington elites. Combat and non-combat policies were more likely to appear together in the same story in print news than in online news and print offered more justifications for policy positions than did online news. This dissertation examined how news media affects public opinion by experimentally manipulating news coverage of U.S. policy toward ISIL. Based on a national sample, the current work utilized a 2 (high/low in-group threat)X 2 (high/low in-group strength) experiment to explore the mediating role of group emotions on support for foreign policies. Guided by intergroup emotions theory, this study found that group anger mediated the relationships between in-group threat and a host of combat and non-combat policies, while group anxiety did not. On the other hand, in-group threat and in-group strength interacted to predict group anxiety, resulting in two moderated-mediation models, which predicted support for negotiating with ISIL and modern racism toward Muslims. This experiment demonstrates that these group emotions operate in divergent ways, and that group emotions on the whole function differently than individual emotions when predicting political attitudes.

Syftet med studien var att undersöka hur lärare verksamma i förskoleklass till och med årskurs 3 beskriver arbetet med naturvetenskapliga undersökningar, mål med aktiviteterna samt möjligheter och utmaningar i undervisningssammanhang. Studien hade en kvalitativ ansats med semistrukturerade intervjuer. Det framgick att det var en stor spridning av hur mycket av undervisningstiden som lades på naturvetenskapliga undersökningar, mellan drygt 30 % upp till 75 %. Samtliga fem respondenter använder sig av naturvetenskapliga undersökningar med prövning av hypotes eller idéer och undersökningar utan prövning av hypotes eller idéer. Studien visar också att lärarna är positivt inställda till användandet av naturvetenskapliga undersökningar och ser dem som motivationsbidragare till elevernas lärande. Utmaningarna var färre och beskrevs som negativt tänkande om NO av vissa kolleger samt bristande tillgång till material och lokaler. Lärarna gav skilda svar på frågan om mål med aktiviteterna. Detta indikerar att ett ökat kollegialt utbyte mellan kollegor skulle kunna främja utvecklingen av undervisningen.

Växthusgasutsläpp från personbilar påverkar klimatet negativt och har lett till att vi idag står inför stora utmaningar. För att minska på växthusgasutsläppen krävs att människor förändrar sina transportbeteenden. Nudging är ett koncept som används för att komplettera befintliga åtgärder och bygger på att en valsituation arrangeras på ett sätt som hjälper människan att fatta ett önskvärt beslut utan att begränsa individens valfrihet. Det finns olika typer av nudge-verktyg, varav ett handlar om framing av information. Framing innebär att en viss typ av information presenteras på ett visst sätt genom att via kommunikationstexter belysa ett särskilt problem. Huvudsyftet med föreliggande studie är att med hjälp av en enkätundersökning demonstrera om, och i så fall hur, framing av information och bilder påverkar hur människor skattar sina miljöattityder, samt attityder och intentioner till resvanor och val av färdmedel. Ett delsyfte är också att undersöka om framing av geografiskt avstånd påverkar skattningen i enkäten olika. Enkäten besvarades av 120 studenter på Högskolan i Gävle. Enkäten innehöll frågor som mätte generella miljöattityder samt egenkonstruerade frågor som mätte studenternas attityder och intentioner till sina resvanor och val av färdmedel. Tre enkäter utformades, varav två innehöll framing av information om problemet med växthusgasutsläpp från personbilar, samt en kompletterande bild utifrån ett geografiskt lokalt respektive globalt perspektiv. Resultaten visade att framing inte hade någon signifikant påverkan på hur studenterna skattade sina miljöattityder, eller sina attityder och intentioner till resvanor och val av färdmedel. Resultaten indikerade heller inte på några skillnader mellan hur geografisk framing påverkade skattningen. Baserat på resultaten har det metodiska förfarandet diskuterats. Ett antagande är att framingen haft större chans till att ge en effekt om budskapet varit skarpare och mer oroväckande, och om urvalet gjorts på en annan population än studenter. Resultaten påvisar dock vikten av att fortsätta testa olika nudges, däribland nudge-verktyget framing, i olika kontexter och att de testas småskaligt innan de implementeras i större skala. / Greenhouse gas emissions from passenger cars have a negative impact on the climate and have led us to face major challenges today. To reduce greenhouse gas emissions, people need to change their transport behavior. Nudging is a concept that is used to supplement existing measures and is based on the fact that a selection situation is arranged in a way that helps man to make a desirable decision without limiting the individual's freedom of choice. There are different types of nudge tools, one of which is about producing information. Framing means that a certain type of information is presented in a certain way by highlighting a particular problem via communication texts. The main purpose of the present study is to demonstrate, by means of a questionnaire survey, whether, and if so, how, presentation of information and images affect how people estimate their environmental attitudes, as well as attitudes and intentions to travel habits and choice of means of transport. A sub-purpose is also to investigate whether framing of geographical distance affects the estimation in the survey differently. The survey was answered by 120 students at the University of Gävle. The questionnaire contained questions that measured general environmental attitudes and self-constructed issues that measured the students' attitudes and intentions to their travel habits and choice of means of transport. Three questionnaires were designed, two of which contained information on the problem of greenhouse gas emissions from passenger cars, and a supplementary picture from a geographically local and global perspective. The results showed that framing had no significant impact on how the students estimated their environmental attitudes, or their attitudes and intentions to travel habits and choice of means of transport. The results also did not indicate any differences between how geographical framing affected the estimate. Based on the results, the methodical procedure has been discussed. One assumption is that the framing had a greater chance of giving an effect if the message was sharper and more worrying, and if the selection was made in a different population than students. The results, however, demonstrate the importance of continuing to test different nudges, including the nudge tool framing, in different contexts and that they are tested on a small scale before being implemented on a larger scale.

O presente trabalho foi desenvolvido com o intuito de verificar a influência do efeito escala na variação da forma da curva tensão-deformação e na resistência de duas rochas brasileiras: o arenito silicificado da Formação Botucatu e o basalto da Formação Serra Geral. Para tanto, foram executados ensaios de flexão a três pontos, com controle do processo de fraturamento, em amostras de ambas as rochas. Os ensaios foram conduzidos sobre quatro tamanhos diferentes de corpos de prova. Experimentalmente, não foi observada variação na forma da curva força-deslocamento com o tamanho das amostras. Observou-se também que a variação da resistência em função dos tamanhos das amostras aproxima-se do previsto pela Mecânica da Fratura Elástica Linear. As curvas força-deslocamento obtidas experimentalmente foram comparadas com duas outras curvas obtidas numericamente, uma através de simulações baseadas na Mecânica da Fratura Elástica Linear, e outra com base na teoria do Modelo Coesivo de propagação de fraturas em análise não linear. Os dados obtidos mostram que entre as duas simulações numéricas a que apresenta melhor aproximação à simulação experimental é a do Modelo Coesivo e que ambas subestimam os deslocamentos no trecho pós-ruptura dos ensaios. / This present work has been developed aiming to verify the scale effect influence on the stress-strain curve form as well on the strength of two Brazilian rocks: Botucatu sandstone and basalt from Serra Geral Formation. Using samples of those rocks three point beam bending experiments have been made in with the crack displacement opening mouth was controlled. The experiments have been conducted using four different samples size. In the experiments no variation in the form of the force-displacement curve has been observed considering those chosen samples sizes. The rock strength variation for those samples is approximately the one predicted by the Linear Elastic Fracture Mechanics Theory. The force-displacement curves experimentally achieved were compared with two other curves obtained numerically, one using the Linear Elastic Fracture Mechanics Theory with FEM and other assuming the fictitious Cohesive Crack Model with BEM. It has been verified that among the two numerical procedures the Cohesive Crack Model gives better results and both give smaller displacements after the rupture.

Since the observation of a narrow mass resonance consistent with the Higgs boson by ATLAS and CMS collaborations in 2012, a number of important studies have been made in order to understand the properties of the newly discovered particle. The most fundamental precision measurements include the Higgs coupling to other particles and itself; properties that have a direct relation with the total decay width. The theoretical total width of the Standard Model (SM) Higgs boson is extremely small (4.2 MeV), making its direct measurement by the LHC experiments non feasible due to the finite experimental detector resolution. Recent publications have shown a novel way to set an indirect limit on the total Higgs boson width by using measurements of both off-shell and on-shell production. This thesis presents a determination of the off-shell Higgs boson coupling, and a further interpretation of the Higgs total width in the H → ZZ → 4l channel (l = e; μ). The results are based on pp collision data collected by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 20.3 fb-1 at a collision energy of √s = 8 TeV. Using the CLs statistical method and assuming the same higher-order QCD corrections applied for both signal and background processes, the observed 95% confidence level (CL) upper limit on the off-shell signal strength is 7.3 (with the yields normalized to the SM expectation). Similarly, the 95% CL upper limit on the Higgs total width is 24.7 MeV. The LHC will undergo its last big upgrade in 2021, in preparation for the high-luminosity LHC Run (HL-LHC), with a luminosity increase of approximately a factor of 5 beyond its nominal design rate. Raising the muon transverse momentum threshold becomes a necessity in order to maintain a low online selection rate with the existing trigger system, at the cost of a reduced efficiency for the electroweak scale physics. An alternative to this approach is a proposed design of a first-level hardware trigger that uses tracking information. Being able to use tracking information at the first level of the ATLAS trigger in the implementation of a muon isolation algorithm offers an extra handle for differentiating between signal and background. The second part of this thesis presents studies on the performance of tracking-based muon isolation designed for a first-level hardware trigger system. These studies demonstrate the improved trigger performance of the muon isolation algorithm when compared to an increase of the transverse momentum threshold of the muon candidates.

This thesis draws on previous engagements between art and Geography in experimental geographies to explore relationships between artists and different forms of institutions. It focuses on experimental artists and associated experimental artist-led collectives, which I term ‘artist-led groups’, to explore how these artists and groups have experimented with different forms of institutions’ as part of their work around science and technology. These experimental artists and groups draw on successive waves of institutional critique in the art world, alongside forms of social practice, to ask key spatial and social questions of institutions. This thesis explores the approaches these experimental artist-led groups and two other key artists have used to experiment with key facets of institutions, allowing them to ask critical questions of science and technology. In doing so, this thesis demonstrates creative approaches to engaging publics around science and technology which offer potential for expanding inter- and cross-disciplinary conversations in geographical discourse. This thesis uses an experimental methodology combining a form of artistic practice as research method on the one hand and ethnographic methods on the other. It combines these methods as part of an ethnography to explore how these artist-led groups associate with one another in a social network. The thesis then focuses on two experimental artists in this social network whose works are becoming increasingly heard within geographical discourse. These experimental artist-led groups and artists are shown to operate different creative approaches when engaging with institutions. I show these in three ways, showing how 1) artist-led groups experiment with different modes of institutions to bring contemporary science and technology issues into the public realm; 2) experimental artist Neal White uses artistic experiments to critique science and technology; and 3) experimental artist Richard Pell uses his Center for PostNatural History to experiment with ways of prompting public discussions around science and technology. Accordingly, this thesis argues that these experimental engagements highlight the benefit of inter- and cross-disciplinary conversations in better understanding and shaping institutions. For geographers, this experimental approach can create novel forms of knowledge to help better understand the social nature and implications of institutions.

Práce vystihuje teoretické poznatky z oblasti simulace a teorie hromadné obsluhy. Tyto poznatky jsou využity při zpracování praktického příkladu. Pro zpracování případové studie je využíván simulační software SIMUL8, pomocí kterého je vytvořen model. Cílem práce je namodelovat současný chod dispečinku, zjistit jeho úzká místa a po té pomocí experimentu s modelem navrhnout nutné rozšíření počtu pracovišť na dispečinku.

An axial compressor for a domestic appliance can be designed to be smaller than an equivalent centrifugal compressor. However, the performance of such a compact axial compression system is limited by increased viscous losses and reduced flow turning at low Reynolds numbers ($Re$). In domestic appliance compressors, $Re$ is typically in the range $10^4$ - $10^5$. Although the aerodynamics of isolated aerofoils operating at these $Re$ have been studied extensively, the flow fields within low $Re$ axial compressors have not been investigated in detail. This dissertation aims to develop an improved understanding of loss variation at low $Re$ and to explore how the losses can be reduced through design changes. Experiments on a 5 times scaled-up single stage axial compressor have been conducted across a range of $Re$ of $10^4$ - $10^5$. The flow field has been characterised using detailed area traverses with a miniaturised five-hole probe at the rotor inlet, rotor exit and stator exit and a miniature hot-wire at the rotor exit. The probe was specifically designed and calibrated for the scale of the experiments and methods to improve the accuracy of the measurements have been applied including a probe geometry correction. The traverse experiments were performed at the design operating condition ($\phi=0.55$ and $Re= 6\times10^4$) and at a condition close to stall for a datum stage design, a stage with an improved stator design and two stators with compound lean. It was found that losses in the rotor were greater than the stator losses across the whole range of $Re$. As expected, the loss decreased with increasing $Re$ for both the stator and rotor. The losses were also increased by three-dimensional flow, with typical loss coefficients at the hub and tip of the blade rows in the range of $20-30\%$. A major contributor to the rotor loss was an unexpected hub separation that increased in size as $Re$ was reduced. At higher $Re$, the major loss sources were the rotor tip leakage, the stator wake and the stator hub separation. The results indicate that an improved stator design that accounts for the actual, measured, rotor exit flow field at low $Re$ could reduce the $Re$ at which blade row losses start to rise dramatically as well as reduce the loss across all $Re$. The improved stator design was better matched to the radial distribution of rotor exit flow angle, which led to a decrease in stator loss across all $Re$. For all stator designs, however, the measured stage stall margin was identical at all $Re$. This, along with the increase in velocity deficit in the rotor tip region at off-design indicates that stall occurred in the rotor and was neither $Re$ nor stator design dependent. The introduction of compound lean to the the stator design had the expected result of decreasing the endwall corner separation loss and increasing midspan losses. The experiments have shown that there was a loss increase in both the midspan and casing region much greater than the corresponding decrease in the stator hub. Also the mass flow redistribution in the experiments was larger that the redistribution predicted by the CFD. Three-dimensional RANS computations at low $Re$ of the same designs as experimentally studied were also conducted in order to investigate the predictive accuracy of industry standard CFD. The simulation results predicted the overall loss distribution but overestimated the end-wall losses and failed to capture the drop in stage performance at low $Re$. The differences with the experiments were caused by the inherent limitations of a fully turbulent solver that cannot reproduce transitional flow-features. Similarly to the experiments, there was no stall margin dependency on $Re$ in the simulations. This thesis has shown that with axial compressors designed specifically for low $Re$, the $Re$ at which the losses start increasing exponentially can be shifted from $10\times10^4$ to $ 4\times10^4$. The loss increase is predominantly caused by the rotor hub corner separation.

abstract: In the realm of network science, many topics can be abstracted as graph problems, such as routing, connectivity enhancement, resource/frequency allocation and so on. Though most of them are NP-hard to solve, heuristics as well as approximation algorithms are proposed to achieve reasonably good results. Accordingly, this dissertation studies graph related problems encountered in real applications. Two problems studied in this dissertation are derived from wireless network, two more problems studied are under scenarios of FIWI and optical network, one more problem is in Radio- Frequency Identification (RFID) domain and the last problem is inspired by satellite deployment. The objective of most of relay nodes placement problems, is to place the fewest number of relay nodes in the deployment area so that the network, formed by the sensors and the relay nodes, is connected. Under the fixed budget scenario, the expense involved in procuring the minimum number of relay nodes to make the network connected, may exceed the budget. In this dissertation, we study a family of problems whose goal is to design a network with “maximal connectedness” or “minimal disconnectedness”, subject to a fixed budget constraint. Apart from “connectivity”, we also study relay node problem in which degree constraint is considered. The balance of reducing the degree of the network while maximizing communication forms the basis of our d-degree minimum arrangement(d-MA) problem. In this dissertation, we look at several approaches to solving the generalized d-MA problem where we embed a graph onto a subgraph of a given degree. In recent years, considerable research has been conducted on optical and FIWI networks. Utilizing a recently proposed concept “candidate trees” in optical network, this dissertation studies counting problem on complete graphs. Closed form expressions are given for certain cases and a polynomial counting algorithm for general cases is also presented. Routing plays a major role in FiWi networks. Accordingly to a novel path length metric which emphasizes on “heaviest edge”, this dissertation proposes a polynomial algorithm on single path computation. NP-completeness proof as well as approximation algorithm are presented for multi-path routing. Radio-frequency identification (RFID) technology is extensively used at present for identification and tracking of a multitude of objects. In many configurations, simultaneous activation of two readers may cause a “reader collision” when tags are present in the intersection of the sensing ranges of both readers. This dissertation ad- dresses slotted time access for Readers and tries to provide a collision-free scheduling scheme while minimizing total reading time. Finally, this dissertation studies a monitoring problem on the surface of the earth for significant environmental, social/political and extreme events using satellites as sensors. It is assumed that the impact of a significant event spills into neighboring regions and there will be corresponding indicators. Careful deployment of sensors, utilizing “Identifying Codes”, can ensure that even though the number of deployed sensors is fewer than the number of regions, it may be possible to uniquely identify the region where the event has taken place. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2019

My dissertation focuses on changes in health-related behavior in react to information-based intervention. The first chapter analyzes the results of a field experiment to investigate the effects of comparative information on the daily number of steps taken of adults. The second chapter further explores the effects using qualitative analysis. The third chapter intends to offer explanations in the mechanisms of the results from the first chapter. My first chapter uncovers how patterns in the daily number of steps of adults are affected by information that compares one with unknown peers. I conducted a field experiment that used fitness trackers to collect daily and minute-by-minute data on the total number of steps an individual takes in a day. Participants were randomized into a group that was provided with comparison information and a group that did not receive such information. I examined whether individuals in the two groups behaved differently during and after the intervention period. I find no clear evidence of an aggregate impact of social norms on the daily number of steps taken. However, I find individuals who are not overweight or nor married or cohabiting are more likely to be influenced by social norms. Greater treatment effects are found among individuals whose number of steps that are at the tails of the distribution curve. My second chapter reports the results of the textual data from the survey in the field experiment. I present dominant themes that emerged from answers to the open-ended essay questions in the survey. The results support that health concern, body image, appearance, psychological factors, peers and friends are major motives for being physically active. For participation in the study specifically, text messages that contain comparative information produced some improvement of the exercise level. However, participants also requested more interactions with peers, additional information provision, rewards for reaching goals. The results imply external incentives play a smaller role in promoting daily number of steps. In the third chapter, I conduct a survey experimentation to test the effectiveness of informing descriptive social norms and types of text messages in predictions about health-related behaviors. First, I investigate if errors in beliefs about activity levels exist and I find no evidence of over- or under-confidence in one’s own activity levels. Further analysis provide preliminary evidence of negative effects of informedness in predictions about one’s own behavior. However, the intention-to-treat effects of comparative information are unclear. The data provide evidence in favor of the correlation between first-order personal beliefs, not higher-order normative beliefs, in predicting an increase number of steps taken in response to intervention with text messages.