Search results for "sähkö"

Generalized finite difference schemes with higher order Whitney forms

2021

Finite difference kind of schemes are popular in approximating wave propagation problems in finite dimensional spaces. While Yee’s original paper on the finite difference method is already from the sixties, mathematically there still remains questions which are not yet satisfactorily covered. In this paper, we address two issues of this kind. Firstly, in the literature Yee’s scheme is constructed separately for each particular type of wave problem. Here, we explicitly generalize the Yee scheme to a class of wave problems that covers at large physics field theories. For this we introduce Yee’s scheme for all problems of a class characterised on a Minkowski manifold by (i) a pair of first ord…

Shaping graphene with optical forging: from a single blister to complex 3D structures

2020

Properties of graphene, such as electrical conduction and rigidity can be tuned by introducing local strain or defects into its lattice. We used optical forging, a direct laser writing method, under an inert gas atmosphere, to produce complex 3D patterns of single layer graphene. We observed bulging of graphene out of the plane due to defect induced lattice expansion. By applying low peak fluences, we obtained a 3D-shaped graphene surface without either ablating it or deforming the underlying Si/SiO2 substrate. We used micromachining theory to estimate the single-pulse modification threshold fluence of graphene, which was 8.3 mJ cm−2, being an order of magnitude lower than the threshold for…

The use of e-government services and the Internet: The role of socio-demographic, economic and geographical predictors

2013

This article explores the use of e-government services from the perspective of digital divides. First, it aims to find out which socio-demographic, economic and geographical factors predict the use of e-government services. Second, the article aims to show whether these factors moderate the way in which the time spent on the Internet is associated with the use of e-government services. The article is based on survey data (N=612) collected in Finland in May–June 2011 and is analysed by using a logistic regression modelling. Results show that gender and income moderate the link between the Internet and e-government service use. The more that women use the Internet, the more they use the gover…

Synthetic electromagnetic knot in a three-dimensional skyrmion

2018

We experimentally simulate a quantum-mechanical particle interacting with knotted electromagnetic fields.

Observation of Poincaré-Andronov-Hopf Bifurcation in Cyclotron Maser Emission from a Magnetic Plasma Trap

2018

We report the first experimental evidence of a controlled transition from the generation of periodic bursts of electromagnetic radiation into the continuous-wave regime of a cyclotron maser formed in magnetically confined nonequilibrium plasma. The kinetic cyclotron instability of the extraordinary wave of weakly inhomogeneous magnetized plasma is driven by the anisotropic electron population resulting from electron cyclotron plasma heating in a MHD-stable minimum-B open magnetic trap. peerReviewed

Into the world of e-waste: mobility among e-scrappers in Nigeria

2017

AbstractIn the management of e-waste, mobility of e-scrappers plays a pivotal role, especially in e-waste acquisition and sales of extracted materials. This research examines the relationship between e-scrappers and the locations of their work by analysing the influence of environmental and social factors on their mobility behaviour in Nigeria. A qualitative analysis of video material collected from 29 male e-scrappers in Nigeria between 2014 and 2015 reveals that e-waste has inherent properties that intermittently mobilise e-scrappers to search for recyclable and valuable electronic trash. Applying the new mobilities paradigm and the new materialism theory, we present that e-scrappers’ mob…

CMC features in lingua franca e-mail messages

2007

Business architecture development at public administration - Insights from government EA method engineering project in Finland

2008

Governments worldwide are concerned for efficient production of services to customers. To improve quality of services and to make service production more efficient, information and communication technology (ICT) is largely exploited in public administration (PA). Succeeding in this exploitation calls for large-scale planning which embraces issues from strategic to technological level. In this planning the notion of enterprise architecture (EA) is commonly applied. One of the sub-architectures of EA is business architecture (BA). BA planning is challenging in PA due to a large number of stakeholders, a wide set of customers, and solid and hierarchical structures of organizations. To support …

Towards a Trustful Digital World : Exploring Self-Sovereign Identity Ecosystems

2021

In the current global situation-burdened by, among others, a vast number of people without formal identification, digital leap, the need for health passports and contact tracking applications-providing private and secure digital identity for individuals, organizations and other entities is crucial. The emerging self-sovereign identity (SSI) solutions rely on distributed ledger technologies and verifiable credentials and have the potential to enable trustful digital interactions. In this human-centric paradigm, trust among actors can be established in a decentralized manner while the identity holders are able to own and control their confidential data. In this paper, we build on observations…

Design of a Programmable and Modular Neuromuscular Electrical Stimulator Integrated Into a Wireless Body Sensor Network

2021

Neuromuscular electrical stimulation finds application in several fields, from basic neurophysiology, to motor rehabilitation and cardiovascular conditioning. Despite the progressively increasing interest in this technique, its State-of-the-Art technology is mainly based on monolithic, mostly wired devices, leading to two main issues. First, these devices are often bulky, limiting their usability in applied contexts. Second, the possibility of interfacing these stimulation devices with external systems for the acquisition of electrophysiological and biomechanical variables to control the stimulation output is often limited. The aim of this work is to describe the design and development of a…