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We investigate the performance of linear consensus algorithms subject to a scaling of the underlying network size. Specifically, we model networked systems with nth order integrator dynamics over families of undirected, weighted graphs with bounded nodal degrees. In such networks, the algebraic connectivity affects convergence rates, sensitivity, and, for high-order consensus [n ≥ 3), stability pr
We study the problem of distributed consensus in networks where the local agents have high-order (n ≥ 3) integrator dynamics, and where all feedback is localized in that each agent has a bounded number of neighbors. We prove that no consensus algorithm based on relative differences between states of neighboring agents can then achieve consensus in networks of any size. That is, while a given algor
In this paper, we study fundamental performance limitations of distributed feedback control in large-scale networked dynamical systems. Specifically, we address the question of whether dynamic feedback controllers perform better than static (memoryless) ones when subject to locality constraints. We consider distributed linear consensus and vehicular formation control problems modeled over toric la
Hörförståelse är en central färdighet i moderna språk som kan vara utmanande att utveckla för eleven. Syftet med denna del är att innehållet ska inspirera till kollegiala reflektioner och diskussioner kring hur eleverna utvecklar hörförståelse i målspråket och vad som påverkar processen. Målet är att ni genom att arbeta med den här delen ska öka era kunskaper om vad som ligger bakom elevernas utma
We study performance limitations of distributed feedback control in large-scale networked dynamical systems. Specifically, we address the question of how the performance of distributed integral control is affected by measurement noise. We consider second-order consensus-like problems modeled over a toric lattice network, and study asymptotic scalings (in network size) of H2 performance metrics tha
Distributed approaches to secondary frequency control have become a way to address the need for more flexible control schemes in power networks with increasingly distributed generation. The distributed averaging proportional-integral (DAPI) controller presents one such approach. In this paper, we analyze the transient performance of this controller, and specifically address the question of its per
We consider frequency control of synchronous generator networks and study transient performance under both primary and secondary frequency control. We model random step changes in power loads and evaluate performance in terms of expected deviations from a synchronous frequency over the synchronization transient; what can be thought of as lack of frequency coherence. We compare a standard droop con
We consider distributed control of double-integrator networks, where agents are subject to stochastic disturbances. We study performance of such networks in terms of coherence, defined through an H2 norm metric that represents the variance of nodal state fluctuations. Specifically, we address known performance limitations of the standard consensus protocol, which cause this variance to scale unbou
In this paper, we compare the transient performance of a multi-terminal high-voltage DC (MTDC) grid equipped with a slack bus for voltage control to that of two distributed control schemes: A standard droop controller and a distributed averaging proportional-integral (DAPI) controller. We evaluate performance in terms of an ℋ2 metric that quantifies expected deviations from nominal voltages, and s
We apply an operator-theoretic viewpoint to a class of non-smooth dynamical systems that are exposed to event-triggered state resets. The considered benchmark problem is that of a pendulum which receives a downward kick at certain fixed angles. The pendulum is modeled as a hybrid automaton and is analyzed from both a geometric perspective and the formalism of Koopman operator theory. A connection
Background: Opioid-based treatment is used to manage stress responses during surgery and postoperative pain. However, opioids have both acute and long-term side effects, calling for opioid-free anaesthetic strategies. This meta-analysis compares adverse events, postoperative recovery, discharge time from post-anaesthesia care unit, and postoperative pain, nausea, vomiting, and opioid consumption b
During severe inflammatory and infectious diseases, various mediators modulate the equilibrium of vascular tone, inflammation, coagulation and thrombosis. This Review describes the interactive roles of the renin–angiotensin system, the complement system, and the closely linked kallikrein–kinin and contact systems in cell biological functions such as vascular tone and leakage, inflammation, chemota
Introduction: Recurrent bleeding in severe haemophilia B causes painful hemarthroses and reduces capacity for physical activity. Recombinant factor IX Fc fusion protein (rFIXFc) prophylaxis results in low annualised bleeding rates, with the potential to improve patients’ health-related quality of life (HRQoL). Aim: To present a post hoc analysis of data from B-LONG describing change over time in p
In this paper, I evaluate some recent attacks on Williamson's claim that knowledge is the most general factive stative propositional attitude. Two types of approaches are discussed: The first approach attempts to show that there are factive mental states denoted by factive mental state operators that are not cases of knowing. The second approach aims to show that there are factive mental states th
Pharmacological and genetic evidence support a role for an involvement of the dopamine D2-receptor (D2-R) in the pathophysiology of schizophrenia. Previous molecular imaging studies have suggested lower levels of D2-R in thalamus, but results are inconclusive. The objective of the present study was to use improved methodology to compare D2-R density in whole thalamus and thalamic subregions betwee
Sexual and reproductive health and rights (SRHR) are an essential component of universal health coverage (UHC). In determining which SRHR interventions to include in their UHC benefits package, countries are advised to evaluate each service based on robust and reliable data, including cost-effectiveness data. We conducted a scoping review of full economic evaluations of the essential SRHR interven
Lateral III-V nanowire (NW) MOSFETs are a promising candidate for high-frequency electronics. However, their circuit performance is not yet assessed. Here, we integrate lateral nanowires (LNWs) in a circuit environment and characterize the transistors and amplifiers. MOSFETs are fabricated in a simple scheme with a dc transconductance of up to 1.3 mS/μm, ON-resistance down to 265 &#
This article contributes to ongoing discussions about frailty and vulnerability in critical gerontology by asserting that possibilities to engage and enact influence in everyday life situations is a crucial dimension of democracy in later life. We discuss how democracy in this sense can be threatened for older persons for whom health and social care services are needed, following from the labellin
Purpose: To analyze the relationship between rates of false positive (FP) responses and standard automated perimetry results. Design: Prospective multicenter cross-sectional study. Methods: One hundred twenty-six patients with manifest or suspect glaucoma were tested with Swedish Interactive Thresholding Algorithm (SITA) Standard, SITA Fast, and SITA Faster at each of 2 visits. We calculated inter
In this preliminary report we present data showing that leukotrienes increase the baseline cell viability in human intestinal epithelial cells and that LTB4 partially reverses the morphological hallmarks of non-necrotic cell death induced by the COX-2 specific inhibitor NS-398. The proposed signaling mechanisms regulating these events are summarized in fig. 3. Please view the work on LT signal tra
