Transient Analysis and Control for Scalable Network Systems

The rapidly evolving domain of network systems poses complex challenges, especially when considering scalability and transient behaviors. This thesis aims to address these challenges by offering insights into the transient analysis and control design tailored for large-scale network systems. The thesis consists of three papers, each of which contributes to the overarching goal of this work.The first paper, A closed-loop design for scalable high-order consensus, studies the coordination of nth-order integrators in a networked setting. The paper introduces a novel closed-loop dynamic named serial consensus, which is designed to achieve consensus in a scalable manner and is shown to be implementable through localized relative feedback. In the paper, it is shown that the serial consensus system will be stable under a mild condition — that the underlying network contains a spanning tree — thereby mitigating a previously known scale fragility. Robustness against both model and feedback uncertainties is also discussed.The second paper, Closed-loop design for scalable performance of vehicular formations, expands on the theory on the serial consensus system for the special case when n=2, which is of special interest in the context of vehicular formations. Here, it is shown that the serial consensus system can also be used to give guarantees on the worst-case transient behavior of the closed-loop system. The potential of achieving string stability through the use of serial consensus is explored.The third paper, Input-output pseudospectral bounds for transient analysis of networked and high-order systems, presents a novel approach to transient analysis of networked systems. Bounds on the matrix exponential, coming from the theory on pseudospectra, are adapted to an input-output setting. The results are shown to be useful for high-order matrix differential equations, offering a new perspective on the transient behavior of high-order networked systems

Використання системи автоматизованого розрахунку для вибору оптимальної конструкції валу ротора молоткової дробарки

Paul Crutzen’s 2006 call for geoengineering research triggered public debate in the mass media of several countries. Since then, a common belief among numerous involved scientists has been that more geoengineering experimentation or research is needed and that geoengineering should be carefully considered in a precautionary way as an emergency option or ‘Plan B’. Despite the controversial potential of geoengineering in terms of mega-risks, ethical dilemmas and governance challenges, public geoengineering debate in the daily press from 2006 to 2013 was heavily dominated by accounts of scientists’ arguments for more geoengineering research or even deployment, only about 8% of mass media articles expressing criticism of geoengineering. However, based on a reading of 700 articles published worldwide in 2014 and 2015, we demonstrate a gradual shift in the coverage, and the daily press now primarily reports critical views of geoengineering technologies. The patterns outlined here point in the same direction: It seems as though the grand idea of geoengineering as Plan B is fading.LUC

Reacting to uncertainty in partial Democracies : the role of negative framing in power struggles in Ukrainian energy politics, 1990s-2000s.

The thesis is about the processes and effects of strategic public elite communication in partial democracies, and Ukraine is used as a case study. The study is situated within the field of comparative politics that investigates the internal dynamics of partial democracies defined here as highly competitive and institutionally weak hybrid regimes. The central argument of this thesis is that the contextual uncertainty inherent in partial democracies produces incentives for political actors to rely on negative framing as a strategy in power struggles, which, in effect, reproduces contextual uncertainty. To understand how negativity functions in partial democracies, the thesis explores the psychological mechanisms of negative framing, its characteristics as a strategy, its conditions of success and effects on the political regime. It advances an innovative analytical framework that connects literatures across different subdisciplines of the social sciences. The theoretical model is derived from a qualitative study of the delegitimization of two state patronage schemes in Ukrainian gas politics. The first case study is confined to a detailed analysis of events and discourses in 1997-1998, i.e., the period when the gas patronage scheme built by the Prime Minister Pavlo Lazarenko became contested and actors involved in its operation were delegitimized. The second case study is devoted to the power struggle around the gas intermediary within the Orange coalition during the presidency of Viktor Yushchenko in 2005-2009. In both cases, I analyze how key political actors involved in these struggles construct their frames, legitimize certain actions and address accusations of misconduct and corruption. The research results show that negative framing aimed at discrediting a political opponent is standard behavior in Ukraine. Overall, such discursive practices have a very negative effect on the political regime and political culture of Ukraine. The result is a cynical population that mistrusts politics and politicians, which in turn reinforces political uncertainty and contributes to the dwindling legitimacy of the government

Trafikklasser för markplattor av natursten : förslag till klassificeringstabell

This report deals with hard surfaces and the factors which are behind the criteria for dimensioning, also dependent on the level, or volume, of traffic. A test was made on slabs of two kinds of natural stone. This was made to see if the values that were reached for breakload was transferable to the same tables that the concrete industry is using for surface dimensions of slabs and paving stones. The test showed very high values and the result, together with the written study, led to the author's suggestion for a classification table where slabs of natural stone were divided in to different classes depending on traffic, thickness and durability.Det finns idag inom betongindustrin tabeller och dimensioneringsanvisningar framtagna för ytor av plattor och marksten i betong. De är framtagna för att underlätta för projektörer så de kan välja rätt produkt för rätt trafikklass. Från stenindustrins sida har inga liknade tabeller ta-gits fram. Detta har setts som en brist av både branschfolk och projektörer. Föreliggande rap-port behandlar området hårdgjorda ytor och vilka faktorer det är som ligger bakom och styr de dimensioneringskrav som finns. Natursten och betong är båda material som har använts historiskt under en lång tid och an-vänds fortfarande även idag. Användningsområdena, på grund av dess goda tryckhållfasthet och beständighet, är ofta ytor som utsätts för trafik och för konstruktioner utomhus som t ex murar. De trafikerade ytorna är uppbyggda av en så kallad överbyggnad som består av ett antal olika lager i olika dimensioner. Beroende på trafiksituation så varierar utformningen. Vägverket delar in överbyggnader i två typer, styva (ex. betongväg) och flexibla (ex. asfaltväg). Ytor av markplattor och marksten i betong och natursten räknas in till de flexibla överbyggnaderna på grund av deras verkningssätt. De olika lager som är typiska för flexibla överbyggnader med beläggning av plattor eller marksten är uppifrån sett slitlagret (plattan/markstenen), sättsands-lager, bärlager och förstärkningslager. Bär- och förstärkningslager utgörs materialmässigt främst av samkross eller makadam och mer sällan idag av naturgrus. Tillsammans vilar de här lagren i överbyggnaden på terrassen. Lagren har olika funktioner och krav ställda på sig som exempelvis dränerande förmåga, jämnhet och styvhet. Överbyggnadsdimensionering är det som är viktigast vid utformningen av en trafikerad yta. Om inte de krav som ställs av Vägverket uppfylls finns det stor risk att brott uppstår och ytan blir trafikfarlig. De faktorer som ligger bakom de beräkningar som görs för överbyggnader är bland annat klimat, geologi och tjälfarlighet. Trafiklaster och hur mycket trafik som beräknas förekomma är också av största betydelse för överbyggnadsdimensionering. För att förenkla beräkningsgångar har Vägverket räknat fram olika trafikklasser som används när man skall bestämma dimensioneringen för en överbyggnad. Vikten av att ha valt rätt material till de oli-ka lagren i överbyggnaden har stor inverkan på hur bra överbyggnaden kommer att hålla. De olika materialen har olika styvhet, E-modul, och väljs fel material så finns risk för att ojämn-heter uppstår. Ett högt värde visar på hög styvhet och härigenom också en ökad hållbarhet för överbyggnaden. E-modulen varierar också för de olika materialen med årstiden. Ytor av plattor eller marksten kan läggas i olika mönster. De fogar som blir mellan mönstren måste fyllas upp med fogsand så att ytan blir stabil. De krafter som uppstår vid belastning blir härmed jämnt fördelade och risken för att sättningar och skador i beläggningen skall uppstå minskar. En undersökande provning utfördes på plattor av natursten, av två sorter, vid SP i Borås. Syf-tet med provningen var att se om de värden som uppnåddes för brottlast var överförbara till liknande tabeller som betongbranschen använder sig av. Provningen visade på höga värden och resultaten, tillsammans med litteraturstudien, ledde fram till författarens förslag av en klassificeringstabell där markplattor av natursten delas in i olika trafikklasser med avseende på deras tjocklek och hållfasthet

Effektivare dokumentering av ÄTA-arbeten

Att undersöka om en effektivare arbetsmetod för hantering av ÄTA-arbeten skulle kunna användas samtidigt som det ger en bättre transparens mellan beställare och entreprenör

Fundamental limitations of case isolation

Case isolation is a strategy with the potential to curb infectious disease epidemics. Expressions for the stability boundary of a case isolation scheme defined through the proportion of the infectious population that it isolates with a given delay have recently been established. Here we quantify how this stability boundary moves when heterogeneity of the inter-individual contact network increases, and explain the underlying mechanism through insightful examples

The importance of work organization on workload and musculoskeletal health - Grocery store work as a model.

We have evaluated the consequences of work organization on musculoskeletal health. Using a postal questionnaire, answered by 1600 female grocery store workers, their main work tasks were identified and four work groups were defined (cashier, picking, and delicatessen work, and a mixed group, who performed a mix of these tasks). The crude odds ratios (ORs) for neck/shoulder complaints were 1.5 (95% CI 1.0-2.2), 1.1 (0.7-1.5) and 1.6 (1.1-2.3), respectively, compared to mixed work. Adjusting for individual and psychosocial factors had no effect on these ORs. For elbows/hands, no significant differences were found. Technical measurements of the workload showed large differences between the work groups. Picking work was the most strenuous, while cashier work showed low loads. Quantitative measures of variation revealed for mixed work high between minutes variation and the highest between/within minutes variation. Combining work tasks with different physical exposure levels increases the variation and may reduce the risk of musculoskeletal complaints

Relationship between commuting and health outcomes in a cross-sectional population survey in southern Sweden

<p>Abstract</p> <p>Background</p> <p>The need for a mobile workforce inevitably means that the length of the total work day (working and traveling time) will increase, but the health effects of commuting have been surprisingly little studied apart from perceived stress and the benefits of physically active commuting.</p> <p>Methods</p> <p>We used data from two cross-sectional population-based public health surveys performed in 2004 and 2008 in Scania, Sweden (56% response rate). The final study population was 21, 088 persons aged 18-65, working > 30 h/week. Duration (one-way) and mode of commuting were reported. The outcomes studied were perceived poor sleep quality, everyday stress, low vitality, mental health, self-reported health, and absence from work due to sickness during the past 12 months. Covariates indicating socioeconomic status and family situation, overtime, job strain and urban/rural residency were included in multivariate analyses. Subjects walking or cycling to work < 30 min were used as a reference category.</p> <p>Results</p> <p>Monotonous relations were found between duration of public transport commuting and the health outcomes. For the category commuting > 60 min odds ratios (ORs) ranged from 1.2 - 1.6 for the different outcomes. For car commuting, the relationships were concave downward or flat, with increasing subjective health complaints up to 30-60 min (ORs ranging from 1.2 - 1.4), and lower ORs in the > 60 min category. A similar concave downward relationship was observed for sickness absence, regardless of mode of transport.</p> <p>Conclusions</p> <p>The results of this study are concordant with the few earlier studies in the field, in that associations were found between commutation and negative health outcomes. This further demonstrates the need to consider the negative side-effects of commuting when discussing policies aimed at increasing the mobility of the workforce. Studies identifying population groups with increased susceptibility are warranted.</p

Collagen Type I Improves the Differentiation of Human Embryonic Stem Cells towards Definitive Endoderm

Human embryonic stem cells have the ability to generate all cell types in the body and can potentially provide an unlimited source of cells for cell replacement therapy to treat degenerative diseases such as diabetes. Current differentiation protocols of human embryonic stem cells towards insulin producing beta cells focus on soluble molecules whereas the impact of cell-matrix interactions has been mainly unattended. In this study almost 500 different extracellular matrix protein combinations were screened to systemically identify extracellular matrix proteins that influence differentiation of human embryonic stem cells to the definitive endoderm lineage. The percentage of definitive endoderm cells after differentiation on collagen I and fibronectin was >85% and 65%, respectively. The cells on collagen I substrates displayed different morphology and gene expression during differentiation as assessed by time lapse studies compared to cells on the other tested substrates. Global gene expression analysis showed that cells differentiated on collagen I were largely similar to cells on fibronectin after completed differentiation. Collectively, the data suggest that collagen I induces a more rapid and consistent differentiation of stem cells to definitive endoderm. The results shed light on the importance of extracellular matrix proteins for differentiation and also points to a cost effective and easy method to improve differentiation

Migrant minors in detention: Practical needs and the limits set by the European Convention

State officials report practical needs to put migrant minors in detention, and the European Convention on Human Rights sets legal limits on this practice. This article defines the scope of circumstances under which migrating minors may be detained by analyzing The European Court of Human Rights case law, using judgments in which the detention of migrant minors has been alleged a violation of Articles 3, 5.1, or 8. It also explores states’ needs for detaining such children, using data from 19 interviews with Swedish police officers, and compares these views with the case law. Police interviewees primarily describe two needs to detain children: to make deportations of children smooth and dignified, and to prevent minors from committing crimes. The investigation finds that migrant minor detentions are rarely permissible according to the Convention—especially under Article 3—and that the permissible scope is too small to meet the expressed practical needs. The actors involved in the issue of detaining migrant minors might have different perspectives on the issue, but they must not lose sight of the fact that these children are categorized as some of the most vulnerable in society and that their rights must be protected