Sökresultat

Filtyp

Din sökning på "*" gav 537704 sökträffar

Inversion efficiency model yields improved accuracy in MP2RAGE-based T1-mapping in the human brain at 7.0T

Introduction: Estimation of the longitudinal relaxation time T1 from the MP2RAGE pulse sequence is based on a monoexponential signal evolution model. However, magnetization transfer caused by the inversion pulse induces a fast relaxation component which appears as a reduction in the efficiency of the inversion. This may explain the underestimation of T1 derived from MP2RAGE. To address this system

Den utställda idrotten : Idrott som kulturarv på idrottsmuseer i Sverige

The purpose of this dissertation is to explore the heritagisation of Swedish sports, which is examined through studies of five Swedish sports museums of today. Additionally, the disseration explores the heritagisation of Swedish sports in a wider historical perspective, mainly focusing on the years between 1900 and 2000.There are plenty of sports museums in Sweden today, most of them run by amateu

Assessing the elevational synchronization in vegetation phenology across Northern Hemisphere mountain ecosystems under global warming

In recent decades, changes in vegetation phenology have exhibited a tight coupling with global warming. Mountain ecosystems are particularly susceptible to climate change, with high elevations warming faster than lower areas. The inconsistent rate of temperature change across elevations may lead to synchronization of phenological patterns, reducing the differences in phenology timing between high

Optimal Control on Positive Cones

An optimal control problem on finite-dimensional positive cones is stated. Under a critical assumption on the cone, the corresponding Bellman equation is satisfied by a linear function, which can be computed by convex optimization. A separate theorem relates the assumption on the cone to the existence of minimal elements in certain subsets of the dual cone. Three special cases are derived as examp

Attack Stealthiness and Detection of Multiagent Systems : A Zero-Sum Formulation

Cybersecurity has in recent years emerged as a paramount concern in the design and operation of industrial systems and civil infrastructures, due mainly to their susceptibility to malicious cyber attacks which take advantage of the vulnerability of communication networks and IT devices. In this paper, we investigate such an attack and counter attack scenario by considering multiagent systems, a so

Global Methane Budget 2000-2020

Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. CH4 is the second most important human-influenced greenhouse gas in terms of climate forcing after carbon dioxide (CO2), and both emissions and atmospheric concentrations of CH4 have continued to increase since 2007 after a temporary pause. The relative importance

Sea floor classification from airborne lidar data

Airborne depth sounding lidar has proven to be a valuable sensor for rapid and accurate sounding of shallow areas. The received lidar pulse echo contains information of the sea floor depth, but also other data can be extracted. We currently perform work on bottom classification and water turbidity estimation based on lidar data. In this paper we present the theoretical background and experimental

III-V MOSFETs for RF Applications

Integration of high-quality oxides on III-V materials allows for versatile design of electronic devices, suitable for RF and power applications. We here present an overview of our results of planar and non-planar III-V MOSFETs for RF electronics, highlighting possibilities and challenges.

An Experimental Study of Jet-Wall and Jet-Jet Interactions of Directly Injected Hydrogen and Methane in a Wave-Piston Geometry

This study investigates the interaction dynamics of directly injected (DI) hydrogen and methane jets with wall and neighboring jets in a non-reactive environment, focusing on the influence of wave-shaped piston geometry. Experiments were conducted in a high-pressure optical chamber using a custom 2-hole DI injector, with Schlieren imaging employed to capture the temporal evolution of jet structure

Optical and Laser Diagnostics on the Effects of Wave-shaped Piston Geometry in a Heavy-duty CI Engine

In this work, a novel piston design with wave-structures around the periphery of piston bowl, was studied to investigate the effect of waves on fuel and air mixing, and combustion processes in a heavy-duty optical engine. Lower soot emissions were achieved with this piston geometry in previous works. High-speed particle image velocimetry (PIV) was used to capture the flow field inside the combusti

I floden av källpublikationer : Mediehistoriska perspektiv på svensk urkundsutgivning, 1834–1847

An outpouring of scholarly editions: Media history perspectives on the editing of historical sources in Sweden, 1834–1847This article examines the scholarly editing of historical sources for publication in nineteenth-century Sweden. The analysis focuses on the approximately 500 letters exchanged between Hans Järta, the Director General of the National Archives of Sweden, and Bror Emil Hildebrand,

Infrastructuring the policymaking, funding and positioning of libraries : unpacking tensions in public library policies in three European cities

Public libraries are increasingly acknowledged as important social infrastructures that can stimulate a sense of community, social cohesion and mental wellbeing. This paper investigates how (inter)national, provincial and local policies conceptualise and fund libraries as social infrastructures in three European cities. Drawing on 32 semi-structured interviews with library management and associatiPublic libraries are increasingly acknowledged as important social infrastructures that can stimulate a sense of community, social cohesion and mental wellbeing. This paper investigates how (inter)national, provincial and local policies conceptualise and fund libraries as social infrastructures in three European cities. Drawing on 32 semi-structured interviews with library management and associati

On-Chip Light Transmission between Nanoscale Optoelectronic Devices

On-chip light broadcasting can reduce spatial footprint and enhance energy efficiency in photonic neuromorphic systems. We demonstrate on-chip light transmission between InP nanowire photodiodes on silicon, addressing the gap towards complete nanoscale photonic integrated circuits.