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Convex formulations of dynamic network traffic assignment for control of freeway networks

We study System Optimum Dynamic Traffic Assignment (SO-DTA) for realistic traffic dynamics controlled by variable speed limits, ramp metering, and routing controls. We consider continuous-time cell-based Dynamic Network Loading models that include as special cases the Cell Transmission Model (CTM) with FIFO rule at the diverge junctions as well as non-FIFO diverge rules. While a straightforward co

Robustness of large-scale stochastic matrices to localized perturbations

Many linear dynamics over networks can be related by duality to the evolution of a Markov chain with state space coinciding with the node set of the network. Examples include opinion dynamics over social networks as well as distributed averaging algorithms for estimation or control. When the transition probability matrix P associated to the Markov chain is irreducible, a key quantity is its invari

On maximally stabilizing traffic signal control with unknown turn ratios

This paper designs distributed dynamic traffic signal control policies for urban traffic networks. Vehicles at the end of an approach to an intersection queue up in separate lanes corresponding to different possible turn maneuvers at the upcoming intersection, according to fixed turn ratios. The departure rate of vehicles from the queue is governed by traffic signal control at the intersections. W

Enhanced summer warming reduces fungal decomposer diversity and litter mass loss more strongly in dry than in wet tundra

Many Arctic regions are currently experiencing substantial summer and winter climate changes. Litter decomposition is a fundamental component of ecosystem carbon and nutrient cycles, with fungi being among the primary decomposers. To assess the impacts of seasonal climatic changes on litter fungal communities and their functioning, Betula glandulosa leaf litter was surface-incubated in two adjacen

Length Distributions of Nanowires Growing by Surface Diffusion

We present experimental data on the time and radius-dependent length distributions of Au-catalyzed InAs nanowires grown by metal organic vapor phase epitaxy. We show that these distributions are not as sharp as commonly believed. Rather, they appear to be much broader than Poissonian from the very beginning and spread quickly as the nanowires grow. We develop a model that attributes the observed b

Comparing Analog Front-Ends for Duty-Cycled Wake-Up Receivers in Wireless Sensor Networks

Using ultralow-power wake-up receivers (WRxs) can reduce idle listening energy cost in wireless sensor networks with low traffic intensity. This has led to many WRx analog front-end (AFE) designs presented in literature, with a large variety of trade-offs between the sensitivity, the data rate, and the power consumption. Energy consumed during wake-up in a network depends on many parameters and wi

Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities

Recent research using repeat photography, long-term ecological monitoring and dendrochronology has documented shrub expansion in arctic, high-latitude and alpine tundra ecosystems. Here, we (1) synthesize these findings, (2) present a conceptual framework that identifies mechanisms and constraints on shrub increase, (3) explore causes, feedbacks and implications of the increased shrub cover in tun

Holistic approach for treatment of accidental hazards during conceptual design of bridge - A case study in Sweden

The control of risks in engineering design is, for most conventional construction projects, achieved through the use of design codes. However, relying on design based on code-compliance can lead to situations where risks are overlooked or inadequately treated; a complementary approach is needed. In this paper, a holistic risk-informed approach for the treatment of accidental hazards during the con

Convexity and Robustness of Dynamic Network Traffic Assignment for Control of Freeway Networks

We study System Optimum Dynamic Traffic Assignment (SO-DTA) for realistic traffic dynamics controlled by variable speed limits, ramp metering, and routing controls. We consider continuous-time cell-based Dynamic Network Loading models that include the Cell Transmission Model with FIFO rule at the diverge junctions as well as non-FIFO diverge rules. We consider SO-DTA formulations in which the tota

Prolonged Working Life and Flexible Retirement in Public and Occupational Pension Schemes

The chapter monitors the different pillars of old age pension schemes and discusses coherence and coordination between primarily the public schemes and the occupational pension schemes with the example of the reformed Swedish model and takes into account both labour and tax related consequences. While the public pension scheme in Sweden was subject to significant reforms already 20 years ago, manyThis chapter monitors the different pillars of old-age pension schemes and discusses coherence and coordination, primarily between public schemes and occupational pension schemes, with the example of the reformed Swedish model. The chapter also takes into account both labour and tax-related consequences. While the public pension scheme in Sweden was already subject to significant reforms 20 years

The use of a metabolically structured model in the study of growth, nitrification, and denitrification by Thiosphaera pantotropha

Thiosphaera pantotropha is capable of aerobic heterotropic nitrification and both aerobic and anaerobic denitrification. These phenomena have been studied in acetate-limited aerobic and anaerobic continous cultures supplied with ammonia and nitrate. The internal reaction rates were defined, based on biochemical knowledge. The observable external conversion rates are related through a linear equati

Heterotrophic nitrification and aerobic denitrification in Alcaligenes faecalis strain TUD

Heterotrophic nitrification and aerobic and anaerobic denitrification byAlcaligenes faecalis strain TUD were studied in continuous cultures under various environmental conditions. Both nitrification and denitrification activities increased with the dilution rate. At dissolved oxygen concentrations above 46% air saturation, hydroxylamine, nitrite and nitrate accumulated, indicating that both the ni

Resilient Educational Outcomes: Participation in School by Youth With Histories of Homelessness

Disrupted high school experiences, including dropout, are educational consequences for many youth with histories of homelessness. Using an ecological resilience prediction model (ERPM) based on the literature on resilience in at-risk youth, the study followed 82 youth who were initially homeless for a 2-year period, to identify predictors of participating in school. Female sex and increased durati

Influence of gut microbiota on mouse B2 B cell ontogeny and function

A complex interplay between the microbiota and the host immune system is evidenced to shape the immune system throughout life, but little is known about the microbial effect on key players of the adaptive immune system, the B2 B cells. In the presented study, we have evaluated the effect of commensal bacteria on B cell ontogeny and function, with the focus on B2 B cells of spleen and Peyer's patch

Time-resolved quantitative proteome analysis of in vivo intestinal development

Postnatal intestinal development is a very dynamic process characterized by substantial morphological changes that coincide with functional adaption to the nutritional change from a diet rich in fat (milk) to a diet rich in carbohydrates on from weaning. Time-resolved studies of intestinal development have so far been limited to investigation at the transcription level or to single or few proteins

Breaking the vicious circle. Studies on the interplay between mental health and school achievement among students in the first years of primary school in Sweden.

The general objective of this thesis was to increase the knowledge of how mental health and school performance are associated and how interventions may be designed and implemented to enhance the two.The data used in the four quantitative studies on which this thesis is based were derived from two age cohorts of students attending 14 elementary schools in two cities in the southern part of Sweden.

Shrub expansion may reduce summer permafrost thaw in Siberian tundra

Climate change is expected to cause extensive vegetation changes in the Arctic: deciduous shrubs are already expanding, in response to climate warming. The results from transect studies suggest that increasing shrub cover will impact significantly on the surface energy balance. However, little is known about the direct effects of shrub cover on permafrost thaw during summer. We experimentally quan