Search results for "550"
showing 10 items of 1192 documents
Constraints on Cosmic Strings Using Data from the Third Advanced LIGO–Virgo Observing Run
2021
We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 data set. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks and, for the first time, kink-kink collisions.cA template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension, $G\mu$, as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models.cAdditionally, we develop and test a third model which interpolat…
Volatility of secondary organic aerosol during OH radical induced ageing
2011
The aim of this study was to investigate oxidation of SOA formed from ozonolysis of <i>&alpha;</i>-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ) in Jülich. A fresh SOA was produced from ozonolysis of <i>&alpha;</i>-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in…
Widely Acclaimed but Lowly Utilized: Congruencing ODL Utilization with its Wide Acclaim
2019
World over, open distance learning (ODL) is widely articulated and vouchered as a panacea pedagogy for increased access and flexibility to higher education. In reality, however, the actual use of ODL approaches in higher institutions of learning in developing regions is unexpectedly low and not in tandem with its wide favorable regional and international vouchering. This paper has the goal to suggest a framework for congruencing the low utilization levels of ODL approaches with their wide acclaim. Using a cross sectional survey, an inquiry was conducted among faculty across institutions of higher learning in Uganda to establish: i) the factors explaining the wide acclaim for ODL; ii) the ut…
A Lite Romanian BERT: ALR-BERT
2022
Large-scale pre-trained language representation and its promising performance in various downstream applications have become an area of interest in the field of natural language processing (NLP). There has been huge interest in further increasing the model’s size in order to outperform the best previously obtained performances. However, at some point, increasing the model’s parameters may lead to reaching its saturation point due to the limited capacity of GPU/TPU. In addition to this, such models are mostly available in English or a shared multilingual structure. Hence, in this paper, we propose a lite BERT trained on a large corpus solely in the Romanian language, which we cal…
Single-channel speech enhancement using implicit Wiener filter for high-quality speech communication
2022
AbstractSpeech enables easy human-to-human communication as well as human-to-machine interaction. However, the quality of speech degrades due to background noise in the environment, such as drone noise embedded in speech during search and rescue operations. Similarly, helicopter noise, airplane noise, and station noise reduce the quality of speech. Speech enhancement algorithms reduce background noise, resulting in a crystal clear and noise-free conversation. For many applications, it is also necessary to process these noisy speech signals at the edge node level. Thus, we propose implicit Wiener filter-based algorithm for speech enhancement using edge computing system. In the proposed algor…
Modelling, Identification and Control of a 5-DOF Shotcrete Robot : Development of a Framework for Automatic Application of Shotcrete for AMV 4200H
2019
Master's thesis Mechatronics MAS500 - University of Agder 2019 Today, process automation is the primary area of development in the shotcrete industry. Automaticshotcrete operations can yield an increase in operational efficiency and personnel safety as well asreductions in cost and environmental impact. This thesis develops a framework for automaticapplication of shotcrete using the AMV 4200H and provides an automatic spraying mode usinginteroceptive sensing. The shotcrete vehicle is equipped with a five degrees-of-freedom manipulatorand is currently operated manually. Our contributions include solving the forward kinematicsthrough the Denavit-Hartenberg convention, and the inverse kinemati…
Bi-objective multi-layer location–allocation model for the immediate aftermath of sudden-onset disasters
2019
International audience; Locating distribution centers is critical for humanitarians in the immediate aftermath of a sudden-onset disaster. A major challenge lies in balancing the complexity and uncertainty of the problem with time and resource constraints. To address this problem, we propose a location–allocation model that divides the topography of affected areas into multiple layers; considers constrained number and capacity of facilities and fleets; and allows decision-makers to explore trade-offs between response time and logistics costs. To illustrate our theoretical work, we apply the model to a real dataset from the 2015 Nepal earthquake response. For this case, our method results in…
Combined numerical and experimental study of microstructure and permeability in porous granular media
2020
&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;Fluid flow on different scales is of interest for several Earth science disciplines like petrophysics, hydrogeology and volcanology. To parameterize fluid flow in large-scale numerical simulations (e.g. groundwater and volcanic systems), flow properties on the microscale need to be considered. For this purpose experimental and numerical investigations of flow through porous media over a wide range of porosities are necessary. In the present study we sinter glass bead media with&amp;#160;various porosities, representing shallow depth crustal sediments.&amp;#160;The microstructure, namely effective porosity …
Water budgets of three small catchments under montane forest in Ecuador: experimental and modelling approach
2006
The water budget of forested catchments controls the local water supply and influences the regional climate. To assess the anthropogenic impact on the water cycle, we constructed a water budget for three ∼10 ha catchments under lower montane forest on the east-facing slope of the Andes in south Ecuador at 1900–2150 m elevation. We used field hydrological measurements and modelled surface flows with TOPMODEL, a semi-distributed catchment model. We measured incident precipitation, throughfall, stemflow, and surface flow between May 1998 and April 2002 in hourly to weekly resolution, and determined all variables needed to parameterise TOPMODEL. On average, of the four monitored years and three…
Real-Life Experiments based on IQRF IoT Testbed: From Sensors to Cloud
2018
Master's thesis Information- and communication technology IKT590 - University of Agder 2018 Internet of things (IoT) is the next generation internet technology which connects devices and objects intelligently to control data collected by diverse types of sensors, radio frequency identification and other physical objects. To address the challenges in IoT such as integrating artificial intelligent techniques with IoT concept, developing green IoT technologies and combining IoT and cloud computing, various platforms which support reliable and low power wireless connectivity are required. IQRF is a recently developed platform for wireless connectivity. It provides low power, low speed, reliable…