Search results for "Dynamics"

A dynamic performance management approach to support local strategic planning

2015

In spite of efforts devoted in the last decades to local strategic planning, such field of research and practice has been frequently characterized by a lack of implementation. We argue here that this phenomenon is due to the limitations of the static and linear approach to local strategic planning in fostering the development of common shared view among policy makers on the relevant system's structure and behavior. By means of a case-study, we illustrate how an approach based on system dynamics modeling applied to Performance Management can be useful to overcome such weaknesses. The proposed approach enhances a better understanding of the causes and effects related to adopted policies, unde…

A System Dynamics approach to improve clinical risk management effectiveness in an italian hospital ward: a case study.

Anomaly detection approach to keystroke dynamics based user authentication

2017

Keystroke dynamics is one of the authentication mechanisms which uses natural typing pattern of a user for identification. In this work, we introduced Dependence Clustering based approach to user authentication using keystroke dynamics. In addition, we applied a k-NN-based approach that demonstrated strong results. Most of the existing approaches use only genuine users data for training and validation. We designed a cross validation procedure with artificially generated impostor samples that improves the learning process yet allows fair comparison to previous works. We evaluated the methods using the CMU keystroke dynamics benchmark dataset. Both proposed approaches outperformed the previou…

Justification of point electrode models in electrical impedance tomography

2011

The most accurate model for real-life electrical impedance tomography is the complete electrode model, which takes into account electrode shapes and (usually unknown) contact impedances at electrode-object interfaces. When the electrodes are small, however, it is tempting to formally replace them by point sources. This simplifies the model considerably and completely eliminates the effect of contact impedance. In this work we rigorously justify such a point electrode model for the important case of having difference measurements ("relative data") as data for the reconstruction problem. We do this by deriving the asymptotic limit of the complete model for vanishing electrode size. This is s…

Ultrafast electronic relaxation and vibrational cooling dynamics of Au 144(SC2H4Ph)60 nanocluster probed by transient mid-IR spectroscopy

2014

Energy relaxation dynamics of a gold nanocluster with atomically precise composition, Au144(SC2H4Ph)60, is studied by transient mid-IR spectroscopy. The experiment is designed to simultaneously pro...

Fractal dynamics in chaotic quantum transport

2013

Despite several experiments on chaotic quantum transport in two-dimensional systems such as semiconductor quantum dots, corresponding quantum simulations within a real-space model have been out of reach so far. Here we carry out quantum transport calculations in real space and real time for a two-dimensional stadium cavity that shows chaotic dynamics. By applying a large set of magnetic fields we obtain a complete picture of magnetoconductance that indicates fractal scaling. In the calculations of the fractality we use detrended fluctuation analysis -- a widely used method in time series analysis -- and show its usefulness in the interpretation of the conductance curves. Comparison with a s…

Force Distribution Analysis of Mechanochemically Reactive Dimethylcyclobutene

2013

Internal molecular forces can guide chemical reactions, yet are not straightforwardly accessible within a quantum mechanical description of the reacting molecules. Here, we present a force-matching force distribution analysis (FM-FDA) to analyze internal forces in molecules. We simulated the ring opening of trans-3,4-dimethylcyclobutene (tDCB) with on-the-fly semiempirical molecular dynamics. The self-consistent density functional tight binding (SCC-DFTB) method accurately described the force-dependent ring-opening kinetics of tDCB, showing quantitative agreement with both experimental and computational data at higher levels. Mechanical force was applied in two different ways, namely, exter…

Synchronization of hidden chaotic attractors on the example of radiophysical oscillators

2017

In the present paper we consider the problem of synchronization of hidden and self-excited attractors in the context of application to a system of secure communication. The system of two coupled Chua models was studied. Complete synchronization was observed as for self-excited, as hidden attractors. Beside it for hidden attractors some special type of dynamic was revealed.

Dynamic Sustainability. Sustainability Window Analysis of Chinese Poverty-Environment Nexus Development

2015

Sustainability Window is a new analysis tool for assessing the sustainability of development simultaneously in all of its three dimensions (environmental, economic, and social). The analysis method provides information of the maximum and minimum economic development that is required to maintain the direction of social and environmental development towards more sustainable targets. With the Sustainability Window method it is possible to easily analyze the sustainability using different indicators and different time periods making comparative analyses easy. The new method makes it also possible to analyze the dynamics of the sustainability and the changes over time in the width of the window.…

Branching Ratios and Spectral Functions of $\tau$ Decays: final ALEPH measurements and physics implications

2005

The full LEP-1 data set collected with the ALEPH detector at the $Z$ pole during 1991-1995 is analysed in order to measure the $\tau$ decay branching fractions. Extensive systematic studies are performed, in order to match the large statistics of the data sample corresponding to over 300 000 measured and identified $\tau$ decays. Branching fractions are obtained for the two leptonic channels and eleven hadronic channels defined by their respective numbers of charged particles and $\pi^0$'s. Using previously published ALEPH results on final states with charged and neutral kaons, corrections are applied to the hadronic channels to derive branching ratios for exclusive final states without kao…