Search results for "Computer Science Application"
showing 10 items of 3998 documents
Monotone generalized nonlinear contractions and fixed point theorems in ordered metric spaces
2011
The purpose of this paper is to present some fixed point theorems for T -weakly isotone increasing mappings which satisfy a generalized nonlinear contractive condition in complete ordered metric spaces. As application, we establish an existence theorem for a solution of some integral equations.
Enabling Energy Savings in Offshore Mechatronic Systems by using Self-Contained Cylinders
2019
This paper proposes a novel actuation system for an offshore drilling application. It consists of three self-contained electro-hydraulic cylinders that can share and store regenerated energy. The energy saving potential of the proposed solution is analyzed through a multibody system simulation. The self-contained system demonstrates superior energy efficiency compared to the benchmark system representing the state-of-the-art approach used today (i.e., valve-controlled cylinders by means of pressure-compensated directional control valves and counter-balance valves, supplied by a centralized hydraulic power unit). Due to the power on demand capability, the cancellation of the throttling losse…
Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEM) of a Customized Stent-Graft for Endovascular (EVAR) Treatment of Abdominal Aorti…
2023
Background: The treatment of abdominal aortic aneurysm (AAA) is today commonly treated by inserting a stent-graft by the endovascular route, without resorting to open surgery. However, some clinical cases do not allow this less invasive approach, meaning that the stent-graft cannot be inserted and open surgery is used. Methods: In the study, we propose a fluid–structure interaction (FSI) analysis of an aneurysmatic aorta that could not be treated with Endovascular Aneurysm Repair (EVAR). The vessel is reconstructed through segmentation from CT scans and subsequently modeled on CAD software to create the surface and thickness of the vessel itself. Subsequently, we proceeded to carry out Comp…
Iterative Learning Applied to Hydraulic Pressure Control
2018
This paper addresses a performance limiting phenomenon that may occur in the pressure control of hydraulic actuators subjected to external velocity disturbances. It is demonstrated that under certain conditions a severe peaking of the control error may be observed that significantly degrades the performance of the system due to the presence of nonlinearities. The phenomenon is investigated numerically and experimentally using a system that requires pressure control of two hydraulic cylinders. It is demonstrated that the common solution of feed forwarding the velocity disturbance is not effective in reducing the peaking that occurs as a result of this phenomenon. To improve the system perfor…
Isolation of Four Lytic Phages Infecting Klebsiella pneumoniae K22 Clinical Isolates from Spain
2020
This article belongs to the Special Issue Bacteriophage—Molecular Studies.
DM-like anomalies in neutron multiplicity spectra
2021
Abstract A new experiment collects data, since November 2019, at a depth of 210 m.w.e. in the Callio Lab in the Pyhasalmi mine in Finland. The setup, called NEMESIS (New Emma MEasurementS Including neutronS), incorporates infrastructure from the EMMA experiment with neutron and large-area plastic scintillator detectors. The experiment’s primary aim is to combine muon tracking with position-sensitive neutron detection to measure precision yields, multiplicities, and lateral distributions of high-multiplicity neutron events induced by cosmic muons in various materials. The data are relevant for background evaluation of the deep-underground searches for Dark Matter (DM), neutrino-less double b…
Kohn-Sham Decomposition in Real-Time Time-Dependent Density-Functional Theory An Efficient Tool for Analyzing Plasmonic Excitations
2017
The real-time-propagation formulation of time-dependent density-functional theory (RT-TDDFT) is an efficient method for modeling the optical response of molecules and nanoparticles. Compared to the widely adopted linear-response TDDFT approaches based on, e.g., the Casida equations, RT-TDDFT appears, however, lacking efficient analysis methods. This applies in particular to a decomposition of the response in the basis of the underlying single-electron states. In this work, we overcome this limitation by developing an analysis method for obtaining the Kohn-Sham electron-hole decomposition in RT-TDDFT. We demonstrate the equivalence between the developed method and the Casida approach by a be…
Platformed Interactions: How Social Media Platforms Relate to Candidate–Constituent Interaction During Finnish 2015 Election Campaigning
2020
Interaction between candidates and constituents via social media is a well-studied domain. The article takes this research further through a synthesis with platform studies, emerging scholarship that applies a critical perspective to the role of digital platforms in society. Examination of candidate–constituent interaction via Twitter and Facebook during the 2015 Finnish parliamentary elections revealed that the types of interaction differ between the two platforms: Facebook was used for formal campaigning and for praising and expressing support, while Twitter was utilized for information and for seeking and sharing opinions. An additional finding is that interaction approaches may be plat…
Enhanced chain dynamics in loop-sorting-systems by means of layout optimization and a kinematic model of the polygon action
2012
Published version of an article in the journal: Structural and Multidisciplinary Optimization. Also available from the publisher at: http://dx.doi.org/10.1007/s00158-011-0743-7 Poor dynamics owing to polygon action is a known concern in mechanical applications of closed articulated chains. In this paper a kinematic model of the polygon action in large chains of loop-sorting-systems is proposed. Through optimization techniques the chain dynamics is improved by minimizing the polygon action using a parametric model of the track layout as design variables. Three formulations of the kinematic polygon action are tested on an average sized planer tracks layout to find a superior model. Verificati…
COMPUTATIONAL HOMOGENIZATION OF POLYCRYSTALLINE MATERIALS WITH PORES: A THREE-DIMENSIONAL GRAIN BOUNDARY FORMULATION
2012
In this study, the influence of porosity on the elastic effective properties of polycrystalline materials is investigated using a 3D grain boundary micro mechanical model. The volume fraction of pores, their size and distribution can be varied to better simulate the response of real porous materials. The formulation is built on a boundary integral representation of the elastic problem for the grains, which are modeled as 3D linearly elastic orthotropic domains with arbitrary spatial orientation. The artificial polycrystalline morphology is represented using 3D Voronoi Tessellations. The formulation is expressed in terms of intergranular fields, namely displacements and tractions that play …