Search results for "driven"
showing 10 items of 224 documents
A modest but practical software process modeling technique for software process improvement
2002
One of the main problems with software engineering is due to the difficulties in evaluating and improving our software processes, especially in the light of the fact that reuse depends on a process which supports it. Generally used approaches to the evaluation and improvement of software processes are based on the CMM, for example. In this paper we present a technique to improve software processes through modeling and evaluation. The presented technique is fairly easy to use, provides reasonably good results and requires only a fraction of resources required by CMM appraisals. Copyright © 2002 John Wiley & Sons, Ltd.
Rare events and scaling properties in field-induced anomalous dynamics
2012
We show that, in a broad class of continuous time random walks (CTRW), a small external field can turn diffusion from standard into anomalous. We illustrate our findings in a CTRW with trapping, a prototype of subdiffusion in disordered and glassy materials, and in the L\'evy walk process, which describes superdiffusion within inhomogeneous media. For both models, in the presence of an external field, rare events induce a singular behavior in the originally Gaussian displacements distribution, giving rise to power-law tails. Remarkably, in the subdiffusive CTRW, the combined effect of highly fluctuating waiting times and of a drift yields a non-Gaussian distribution characterized by long sp…
Relaxation of Electron Spin during High-Field Transport in GaAs Bulk
2011
A semiclassical Monte Carlo approach is adopted to study the multivalley spin depolarization of drifting electrons in a doped n-type GaAs bulk semiconductor, in a wide range of lattice temperature ($40<T_L<300$ K) and doping density ($10^{13}<n<10^{16}$cm$^{-3}$). The decay of the initial non-equilibrium spin polarization of the conduction electrons is investigated as a function of the amplitude of the driving static electric field, ranging between 0.1 and 6 kV/cm, by considering the spin dynamics of electrons in both the $\Gamma$ and the upper valleys of the semiconductor. Doping density considerably affects spin relaxation at low temperature and weak intensity of the driving electric fiel…
Tests for Differentiation in Gene Expression Using a Data-Driven Order or Weights for Hypotheses
2005
In the analysis of gene expression by microarrays there are usually few subjects, but high-dimensional data. By means of techniques, such as the theory of spherical tests or with suitable permutation tests, it is possible to sort the endpoints or to give weights to them according to specific criteria determined by the data while controlling the multiple type I error rate. The procedures developed so far are based on a sequential analysis of weighted p-values (corresponding to the endpoints), including the most extreme situation of weighting leading to a complete order of p-values. When the data for the endpoints have approximately equal variances, these procedures show good power properties…
Tuning active Brownian motion with shot noise energy pulses
2009
The main aim of this work is to explore the possibility of modeling the biological energy support mediated by absorption of ATP (adenosine triphosphate) as an energetic shot noise. We develop a general model with discrete input of energy pulses and study shot-noise-driven ratchets. We consider these ratchets as prototypes of Brownian motors driven by energy-rich ATP molecules. Our model is a stochastic machine able to acquire energy from the environment and convert it into kinetic energy of motion. We present characteristic features and demonstrate the possibility of tuning these motors by adapting the mean frequency of the discrete energy inputs, which are described as a special shot noise…
Light-driven proton transport of bacteriorhodopsin incorporated into long-term stable liposomes of a polymerizable sulfolipid
1983
Abstract The chromoprotein bacteriorhodopsin from Halobacterium halobium has been incorporated into liposomes made of a fully synthetic, polymerizable lipid. Bacteriorhodopsin is found to be active in these polymer liposomes. The advantage in the use of such polymer systems concerning long-term stability in comparison with liposomes made of natural lipid is demonstrated.
Examining the Impact of ICT on Sustainable Development: A Data-Driven Narrative
2021
Considering the challenges of sustainable development and the mixed prescriptions being offered by the use of digital technologies, we present a data-driven narrative of how ICT development impacts the sustainable growth of economies. The analysis is based on historical panel data from 39 economies across the developed and developing economies. The industry-standard CRISP-DM methodology was applied as it is flexible, robust, and offers a practical approach for data analytics. The findings reveal that there are differentiated outcomes in terms of sustainable growth among high-income and low-income economies. This poses legitimate questions as to whether low-income economies will be able to m…
Recursive modeling for completed code generation
2009
Model-Driven Development is promising to software development because it can reduce the complexity and cost of developing large software systems. The basic idea is the use of different kinds of models during the software development process, transformations between them, and automatic code generation at the end of the development. But unlike the structural parts, fully-automated code generation from the behavior parts is still hard, if it works at all, restricted to specific application areas using a domain specific language, DSL.This paper proposes an approach to model the behavior parts of a system and to embed them into the structural models. The underlying idea is recursive refinements …
True prices, latent prices and the Ghosh model : some inconsistencies
2001
Beside the traditional Leontief demand-driven model, there is the Ghosh supply-driven model. This paper explores the typology of the possible models: demand driven models versus supply driven models, true prices versus latent (or index) prices, coefficients in physical terms versus coefficients in value. This demonstrates that the supply-driven model offers results of limited interest, being incapable to separate quantities and prices; and it is only when a very strange hypothesis is chosen -- demand prices, controlled by the buyer -- that the supply-driven model gives an interesting result with a separation between quantities and prices in the solution, becoming the dual of the Leontief mo…
FREESCOO facade 3.0, a compact DEC thermally driven air-conditioning system for apartments
2020
FREESCOO is an innovative Desiccant Evaporative Cooling air conditioning system designed for ventilation, cooling, dehumidification and heating of buildings in residential and tertiary sectors. This paper presents the third generation of the façade version, which will be tested on field in Milan (Italy) within the Merezzate+ project supported by Climate-KIC. The adsorption bed used by the system is a finned heat exchanger packed with silica gel grains, which allows simultaneous dehumidification and cooling of the process air. The direct evaporative cooling process, operated downstream to the dehumidification, is realized using a rotary plate humidifier. The regeneration of the adsorption be…