English
norskBlar i tittel Artikler, rapporter og annet (datateknologi og beregningsorienterte ingeniørfag)
Viser treff 85-104 av 161
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On the boundedness of subsequences of Vilenkin-Fejér means on the martingale Hardy spaces
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03)In this paper we characterize subsequences of Fejér means with respect to Vilenkin systems, which are bounded from the Hardy space <i>H<sub>p</sub></i> to the Lebesgue space <i>L<sub>p</sub></i>, for all 0 < p < 1/2. The result is in a sense sharp. -
On the Heat and Wave Equations with the Sturm-Liouville Operator in Quantum Calculus
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-19)In this paper, we explore a generalised solution of the Cauchy problems for the q-heat and q-wave equations which are generated by Jackson’s and the q-Sturm-Liouville operators with respect to t and x, respectively. For this, we use a new method, where a crucial tool is used to represent functions in the Fourier series expansions in a Hilbert space on quantum calculus. We show that these solutions ... -
On Weighted Fourier InequalitieS –– Some New Scales of Equivalent Conditions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06)For Lebesgue spaces on R<sup>n</sup>, we study two-weight p → q-inequalities for Fourier transform. Some sufficient conditions on weights for such inequalities are known for special ranges of parameters p and q. In the same ranges of parameters we show, that in every case each of those conditions can be replaced by infinitely many conditions, even by continuous scales of conditions. We also ... -
Osmosis for non-electrolyte solvents in permeable periodic porous media
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-08)The paper gives a rigorous description, based on mathematical homogenization theory, for flows of solvents with not charged solute particles under osmotic pressure for periodic porous media permeable for solute particles. The effective Darcy type equations for the flow under osmotic pressure distributed within the porous media are derived. The effective Darcy law contains an additional flux term ... -
Path Planning for Perception-Driven Obstacle-Aided Snake Robot Locomotion
(Chapter; Bokkapittel, 2020)Development of snake robots have been motivated by the ability of snakes to move efficiently in unstructured and cluttered environments. A snake robot has the potential to utilise obstacles for generating locomotion, in contrast to wheeled robots which are unable to move efficiently in rough terrain. In this paper, we propose a local path planning algorithm for snake robots based on obstacle-aided ... -
Periodic homogenization of nonlocal operators with a convolution-type kernel
(Journal article; Peer reviewed; Tidsskriftartikkel, 2017)The paper deals with a homogenization problem for a nonlocal linear operator with a kernel of convolution type in a medium with a periodic structure. We consider the natural diffusive scaling of this operator and study the limit behavior of the rescaled operators as the scaling parameter tends to 0. More precisely we show that in the topology of resolvent convergence the family of rescaled operators ... -
Pointwise estimates for heat kernels of convolution-type operators
(Journal article; Peer reviewed; Tidsskriftartikkel, 2018-04-16)We study the large‐time behaviour of the fundamental solution of parabolic equations with an elliptic part being non‐local convolution‐type operator. We assume that this operator is a generator of a Markov jump process, and that its convolution kernel decays at least exponentially at infinity. The fundamental solution shows rather different asymptotic behaviour depending on whether | x | ≲ t , or t ... -
Potential type operators in PDEs and their applications
(Journal article; Peer reviewed; Tidsskriftartikkel, 2017-01)We prove the boundedness of Potential operator in weighted generalized Morrey space in terms of Matuszewska-Orlicz indices of weights and apply this result to the Hemholtz equation in ℝ<sup>3</sup> with a free term in such a space. We also give a short overview of some typical situations when Potential type operators arise when solving PDEs. -
Pre-evaluation and interactive editing of B-spline and GERBS curves and surfaces
(Conference object; Konferansebidrag, 2017-12)Interactive computer based geometry editing is very useful for designers and artists. Our goal has been to develop useful tools for geometry editing in a way that increases the ability for creative design. When we interactively editing geometry, we want to see the change happening gradually and smoothly on the screen. Pre-evaluation is a tool for increasing the speed of the graphics when doing ... -
Predicting Bedside Falls using Current Context
(Peer reviewed; Chapter; Bokkapittel, 2018-02-05)Each year about a third of the elderly aged 65 or older experience a fall. Many of these falls could be avoided if fall risk assessment and prevention tools where available in the daily living situation. Such tools would need to use the current context as input to predict an imminent fall. This paper presents an approach predicting imminent falls using data from a roof-mounted infrared array combined ... -
Predicting Peak Prices in the Current Day-Ahead Market
(Chapter; Bokkapittel, 2023-06)The work presented has studied price developments in the day-ahead market. The statistical properties inherent in the time series constituting the day-to-day prices have been investigated. It is shown that these properties are radically different in 2022 than former years and resemble more chance like properties for which make predicting future peak prices especially hard. To overcome this, a space ... -
Preliminary studies on transition curve geometry: Reality and virtual reality
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-01)The topic of transition curves is well known in track and road engineering. Over the years the need for easement between straight and curved sections in railway and road design has grown, with an important reason being increase in vehicle speed. Testing of transitions is often done with graph analysis where the property of lateral change of acceleration is compared between varieties of curves. ... -
Properties of sequence of linear functionals on BV with applications
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-24)This paper is devoted to investigating the sequence of some linear functionals in the space BV of finite variation functions. We prove that under certain conditions this sequence is bounded. We also prove that this result is sharp. In particular, the obtained results can be used to study convergence of some general Fourier series. Moreover, the obtained conditions seem to be new and useful also for ... -
Quantitative analysis of accuracy of voidage computations in CFD-DEM Simulations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012) -
Railway transition curves: A review of the state-of-the-art and future research
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-18)Transition curves are a useful tool for lateral alignment of railway segments. Their design is important to ensure safe and comfortable travel for passengers and cargo. Well designed transition curves can lead to reduced wear of tracks and vehicles, which is beneficial from a maintenance point of view. Extensive studies have been performed through decades to find transition curves that can replace ... -
Real-Time Voxel-based 2D to 3D CT Visualisation Framework for Volumetric Capacity Estimation
(Journal article; Tidsskriftartikkel, 2022)Over the decades medical analyses have grown in importance and practice possibilities. Digital operations like split-image procedures have become an integral part of modern medical practices and are still gaining momentum. Through the application of this technique medical computed tomography (CT) and magnetic resonance imaging scans (MRI) can be converted to three-dimensional bodies. This paper ... -
Rearrangements and jensen type inequalities related to convexity, superquadracity, strong convexity and 1-quasiconvexity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09)In this paper we derive and discuss some new theorems related to all rearrangements of a given set in Rn , denoted (x) and use the results to prove some new Jensen type inequalities for convex, superquadratic, strongly convex and 1 -quasiconvex functions. -
Recent trends in operation modal analysis techniques and its application on a steel truss bridge
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019)Aging of infrastructure causes many problems with great consequences, essentially economical. Operation modal analysis (OMA) is one of the most crucial techniques used for dynamic analysis of civil engineering structures (e.g. bridges, dams or tunnels). OMA uses various time and frequency domain methods to obtain the modal parameters. The analysis of OMA techniques can be used to detect, locate and ... -
Recognizing Bedside Events Using Thermal and Ultrasonic Readings
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-09)Falls in homes of the elderly, in residential care facilities and in hospitals commonly occur in close proximity to the bed. Most approaches for recognizing falls use cameras, which challenge privacy, or sensor devices attached to the bed or the body to recognize bedside events and bedside falls. We use data collected from a ceiling mounted 80 60 thermal array combined with an ultrasonic sensor ... -
Refinements of Bennett type inequalities
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023)In this paper we discuss, complement and improve some Bennett type inequalities. In particular,we prove a new refinement of a Bennett type inequality using super quadracity argument.
