Search results for "VDP::Matematikk og naturvitenskap: 400"
showing 10 items of 647 documents
New delay-dependent stability conditions for time-varying delay systems
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/360924 Open Access This paper addresses the delay-dependent stability for systems with time-varying delay. First, by taking multi-integral terms into consideration, new Lyapunov-Krasovskii functional is defined. Second, in order to reduce the computational complexity of the main results, reciprocally convex approach and some special transformations are introduced, and new delay-dependent stability criteria are proposed, which are less conservative and have less decision variables than some previous results. Finally, two well-known example…
BioTIME: A database of biodiversity time series for the Anthropocene
2018
Abstract Motivation The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, th…
A Decision-support Algorithm for Self-management of Anticoagulation Therapy Used in a Smartphone Application
2019
Warfarin for anticoagulation therapy is used by patients with specific cardiovascular diseases to control the ability of blood clotting. Traditional ways for self-management of the therapy are based on paper forms and procedures. This paper presents an algorithm developed for the smartphone application “Warfarin Guide”, which is a computer-assisted decision-support system used to help patients with self-management of their anticoagulation therapy related to International Normalized Ratio (INR) values. The algorithm was based on clinical guidelines for Warfarin therapy and it was adapted for the software application to address challenges with regular INR checks and adjustments for temporary …
Streamwater responses to reduced nitrogen deposition at four small upland catchments in Norway
2020
AbstractReduced emissions of nitrogen (N) in Europe have resulted in decreasing atmospheric deposition since 1990. Long-term data (1988–2017) from four small Norwegian catchments located along gradients in N deposition, rainfall, and organic carbon (C) show different responses to 25–30% reductions in N deposition during the same period. At three sites the decreased N deposition caused reduced leaching of nitrate to surface water, whereas the westernmost site showed no decrease, probably due to thin soils with low C:N ratio, poor vegetation cover and high precipitation. The loss of total N to streamwater constituted 30–50% of the N deposition. Losses via denitrification are unknown but assum…
Desiccant Properties Comparison of Natural Bio-polymers
2020
Background and Objective: Desiccants are substances used in the dehumidification process which is vital in order to avoid the degradation of materials. Silica gel is the most prominent type of desiccant used and today the world has developed an interest in bio-polymers due to certain demerits of silica. Hence this study was conducted to investigate the desiccant properties of the four commercial flours wheat, corn, potato and gram and to compare them with the common silica gel desiccant. Materials and Methods: The bio-polymers were dried under vacuum at 120°C and were studied over time using Near-Infrared spectroscopy for their-OH combination peak which appears at around 5200 cm–1 and the d…
An activity theory perspective on contradictions in flipped mathematics classrooms at the university level
2019
Author´s accepted manuscript (postprint). This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Mathematical Education in Science and Technology on 24/03/2019, available online: http://www.tandfonline.com/10.1080/0020739X.2019.1591533.
Distributed Learning Automata-based S-learning scheme for classification
2019
This paper proposes a novel classifier based on the theory of Learning Automata (LA), reckoned to as PolyLA. The essence of our scheme is to search for a separator in the feature space by imposing an LA-based random walk in a grid system. To each node in the grid, we attach an LA whose actions are the choices of the edges forming a separator. The walk is self-enclosing, and a new random walk is started whenever the walker returns to the starting node forming a closed classification path yielding a many-edged polygon. In our approach, the different LA attached to the different nodes search for a polygon that best encircles and separates each class. Based on the obtained polygons, we perform …
Ungdom og e-demokrati : hvilke ønsker og forventninger har ungdom til e-demokrati?
2007
Masteroppgave i informasjonssystemer 2007 - Høgskolen i Agder, Kristiansand E-demokrati er et satsningsområde i offentlig sektor. Det har i Norge vært synkende deltagelse i valg både til Storting og kommunevalg ved de siste valgene. Ungdom i aldersgruppen 18 til 21 år har lavere oppslutning rundt valgene enn eldre aldersgrupper. Flere mener at e-demokrati kan bidra til å øke oppslutning rundt demokratiet og valgene. I denne sammenheng er ungdom en viktig målgruppe. Vi har sett nærmere på e-demokrati rettet mot ungdom. Målet for denne masteroppgaven har vært å forstå hvilke ønsker og forventninger ungdom har til informasjonssystemer innen for edemokrati. For å besvare dette spørsmålet har vi…
Design of an Air Management System for a Dry Room and Utilization of Waste Heat
2021
Master's thesis in Renewable energy (ENE500) This thesis presents the design of an air management system used in a dry room fora lithium-ion battery factory using a Matlab/Simulink environment. The sizing of the system is based on the 32 GWh battery factory, currently under construction by Morrow Batteries in Arendal, Norway. The generic air management system from the literature review was used as a base for the general layout and initial values. Combining coolers and a desiccant dehumidification wheel was the optimal solution for the dehumidification system. The molecular sieve was the selected desiccant due to its high performance at low relative humidity. The outlet air quality from the …
Role of protozooplankton in the diet of North Sea autumn spawning herring (Clupea harengus) larvae
2022
AbstractThe role of small prey (< 200 µm) in larval marine fish nutrition is largely understudied. Here, we explore the contribution of protozooplankton (PZP 20–200 µm) to larval fish diets, compared to metazoan microzooplankton (MZP 55–200 µm). More specifically, we tested whether the contribution of PZP increased during the low productivity season and decreased as larvae grow. We used North Sea autumn spawning herring (Clupea harengus) as a case study, as it is a key species with high commercial and ecological importance. In autumn and winter, the potential PZP and MZP prey was dominated by cells < 50 µm (mainly Gymnodiniales, Pronoctiluca pelagica,Tripos spp. and Strombidium spp.),…