Search results for "Misa"

Comparing technology acceptance of K‐12 teachers with and without prior experience of learning management systems : A Covid‐19 pandemic study

2021

Covid-19 pandemic has caused a massive transformation in K-12 settings towards online education. It is important to explore the factors that facilitate online teaching technology adoption of teachers during the pandemic. The aim of this study was to compare Learning Management System (LMS) acceptance of Finnish K-12 teachers who have been using a specific LMS as part of their regular teaching before the Covid-19 pandemic (experienced group) and teachers who started using it for emergency remote teaching during the pandemic (inexperienced group). Based on the Unified Theory of Acceptance and Use of Technology framework, a self-report questionnaire was administered to 196 teachers (nexperienc…

A New Method for the Price Determination of the Reactive Power Supply

2006

This paper addresses the development of an accurate model for the pricing of reactive power supply as an ancillary service. Reactive power supply is one of the most important ancillary services in the field of transmission systems security. The present work is focused on building a reactive power market at which the Distributors can also take part in injecting reactive power at the connected HV/MV nodes. The authors have studied the particular case of the reactive power supplied by sub-transmission or distribution networks, connected to the nodes of the transmission system. The aim of this work is to establish a reactive power price by crossing demand and offer curves.

Efficient spatial designs using Hausdorff distances and Bayesian optimization

2021

An iterative Bayesian optimisation technique is presented to find spatial designs of data that carry much information. We use the decision theoretic notion of value of information as the design criterion. Gaussian process surrogate models enable fast calculations of expected improvement for a large number of designs, while the full-scale value of information evaluations are only done for the most promising designs. The Hausdorff distance is used to model the similarity between designs in the surrogate Gaussian process covariance representation, and this allows the suggested algorithm to learn across different designs. We study properties of the Bayesian optimisation design algorithm in a sy…

Portfolio optimisation with strictly positive transaction costs and impulse control

1998

One crucial assumption in modern portfolio theory of continuous-time models is the no transaction cost assumption. This assumption normally leads to trading strategies with infinite variation. However, following such a strategy in the presence of transaction costs will lead to immediate ruin. We present an impulse control approach where the investor can change his portfolio only finitely often in finite time intervals. Further, we consider transaction costs including a fixed and a proportional cost component. For the solution of the resulting control problems we present a formal optimal stopping approach and an approach using quasi-variational inequalities. As an application we derive a non…

A Differential Evolution Framework with Ensemble of Parameters and Strategies and Pool of Local Search Algorithms

2014

The file attached to this record is the author's final peer reviewed version. The publisher's final version can be found by following the DOI link. The ensemble structure is a computational intelligence supervised strategy consisting of a pool of multiple operators that compete among each other for being selected, and an adaptation mechanism that tends to reward the most successful operators. In this paper we extend the idea of the ensemble to multiple local search logics. In a memetic fashion, the search structure of an ensemble framework cooperatively/competitively optimizes the problem jointly with a pool of diverse local search algorithms. In this way, the algorithm progressively adapts…

Parametric Design of Sailing Hull Shapes

2006

The author presents an original algorithm aimed at automatically generating the hull shape of a sailing yacht starting from an initial set of parameters. The procedure consists of two steps. First one keel line and a Designed Water Line (DWL in the following) are faired according to a set of parameters, say length of water line, canoe body draft, stem angle and some adimensional coefficients. This information is then used to fair the hull surface, which must in turn fulfil more prerequisites (parameters like displaty cement, floatation area and related coefficients). The hull is defined by means of a B-spline surface, the fairing of which is ensured by allowing for all the imposed objective…

Commento a F. Tamisari, L'atto di nominare e il potere morfopoietico dei nomi e dei toponimi nella cosmogonia yolngu, Terra di Arnhem nordorientale, …

2008

Commento analitico di un articolo etnografico, sul tema delle connessioni tra paesaggio, linguaggio e organizzazione sociale presso gli Yolngu (Australia)

Kalmbergin kartasto R VIII : List 9

1855

On the use of ionic liquids as mobile phase additives in high-performance liquid chromatography. A review.

2015

The popularity of ionic liquids (ILs) has grown during the last decades in several analytical separation techniques. Consequently, the number of reports devoted to the applications of ILs is still increasing. This review is focused on the use of ILs (mainly imidazolium-based associated to chloride and tetrafluoroborate) as mobile phase additives in high-performance liquid chromatography (HPLC). In this approach, ILs just function as salts, but keep several kinds of intermolecular interactions, which are useful for chromatographic separations. Both cation and anion can be adsorbed on the stationary phase, creating a bilayer. This gives rise to hydrophobic, electrostatic and other specific in…

A genetic algorithm for combined topology and shape optimisations

2003

A method to find optimal topology and shape of structures is presented. With the first the optimal distribution of an assigned mass is found using an approach based on homogenisation theory, that seeks in which elements of a meshed domain it is present mass; with the second the discontinuous boundaries are smoothed. The problem of the optimal topology search has an ON/OFF nature and has suggested the employment of genetic algorithms. Thus in this paper a genetic algorithm has been developed, which uses as design variables, in the topology optimisation, the relative densities (with respect to effective material density) 0 or 1 of each element of the structure and, in the shape one, the coord…