Search results for "Transform"
showing 10 items of 3975 documents
Reaching for different ends through tenure track—institutional logics in university career systems
2020
AbstractIn this study, we used the institutional logics perspective to identify the logics underpinning the tenure track career system, how the logics manifest themselves in recruitment and performance management and how academic leaders and academics negotiate between the logics. The study contributes to research on governance dynamics in academia and to universities’ organisational transformation in the context of strategic actorhood. The data comprised interviews with academic leaders (vice-rectors, deans, department heads) and academics in tenure track positions at two Finnish universities. Empirically, the study explores two key areas of human resource management: recruitment and perfo…
Automatic Reengineering in MDA Using Rewriting Logic as Transformation Engine
2005
Legacy systems are information systems that have been developed by means of methods, tools and database management systems that have become obsolete, but they are still being used due to their reliability. As time goes on, the maintenance of this software becomes more complex, expensive and painful. The MOMENT framework supports automatic formal model transformations in MDA. This model transformation approach is based on the algebraic specification of models and benefits from mature term rewriting system technology to perform model transformation using rewriting logic. In this paper, we present how we apply this formal transformation mechanism to recover a legacy relational database, obtain…
Min-max control of uncertain multi-inventory systems with multiplicative uncertainties
2001
In this note, we consider production-distribution systems with buffer and capacity constraints. For such systems, we assume that the model is not known exactly. More precisely, the entries of the matrix representing the system structure may be affine functions of some uncertain time-varying parameters that take values within assigned bounds. We give stabilizability conditions that can be checked, in principle, by solving a min-max problem on the surface of the state-space (buffer level space) unit ball. Then, we consider a special case in which each uncertain parameter affects a single column of the system matrix and is independent of all the other ones. In this case, we propose a mixed int…
Multilinear Fourier multipliers related to time–frequency localization
2013
We consider multilinear multipliers associated in a natural way with localization operators. Boundedness and compactness results are obtained. In particular, we get a geometric condition on a subset A⊂R2d which guarantees that, for a fixed synthesis window ψ∈L2(Rd), the family of localization operators Lφ,ψA obtained when the analysis window φ varies on the unit ball of L2(Rd) is a relatively compact set of compact operators.
Unitary transformations depending on a small parameter
2011
We formulate a unitary perturbation theory for quantum mechanics inspired by the LieDeprit formulation of canonical transformations. The original Hamiltonian is converted into a solvable one by a transformation obtained through a Magnus expansion. This ensures unitarity at every order in a small parameter. A comparison with the standard perturbation theory is provided. We work out the scheme up to order ten with some simple examples.
Spectral identification of forced oscillation in PMU signal using mode decomposition
2018
This article gives a new method to identify the frequency of Forced Oscillation (FO) in phasor measurement units (PMUs) signals. The processing of the signal by Empirical Mode Decomposition (EMD) technique leads to effective detection with improvement in accuracy. After testing some improved versions of EMD, it is observed that ‘improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN-2014)’ is the best version to use in processing. The developed methodology is able to spot the frequency of FOs even if there exist multiple modes with mode mixing and multiple events. In such cases, self-coherence method fails to spot FO. Spectral analysis is conducted on the decom…
The Orchestra of Multiple Model Repositories
2013
This paper motivates and encourages the simultaneous use of multiple model repositories in model-driven software. A multi-repository mechanism is proposed for that. With this mechanism, multiple model repositories residing in the same or different technical spaces can be mounted into a single repository (in the same sense as file systems are mounted in UNIX) and accessed in a uniform way. Relations (including generalizations) between elements from the mounted repositories are supported. Some of the repositories may be “computable” (virtual), which leads to the on-the-fly model transformation concept.
Non-periodic Discrete Splines
2015
Discrete Splines with different spans were introduced in Sect. 3.3.1. This chapter focuses on a special case of discrete splines whose spans are powers of 2. These splines are discussed in more detail. The Zak transform provides an integral representation of such splines. Discrete exponential splines are introduced. Generators of the discrete-spline spaces are described whose properties are similar to properties of polynomial-spline spaces generators. Interpolating discrete splines provide efficient tools for upsampling 1D and 2D signals. An algorithm for explicit computation of discrete splines is described.
Non-periodic Discrete-Spline Wavelets
2015
This chapter describes wavelet analysis in the spaces of discrete splines whose spans are powers of 2. This wavelet analysis is similar to wavelet analysis in the polynomial-spline spaces. The transforms are based on relations between exponential discrete splines from different resolution scales. Generators of discrete-spline wavelet spaces are described. The discrete-spline wavelet transforms generate wavelet transforms in signal space. Practically, wavelet transforms of signals are implemented by multirate filtering of signals by two-channel filter banks with the downsampling factor 2 (critically sampled filter banks). The filtering implementation is accelerated by switching to the polyph…
Las grandes exposiciones del siglo XXI frente a la fragilidad del territorio
2019
Las exposiciones no son eventos autónomos ni homogéneos, al contrario, su desarrollo constituye la trama de una historia discontinua, el espejo de una sociedad en evolución que experimenta sus reglas y sus paradigmas, mostrándolos a la sociedad. A través de cartografía y bibliografía específica, además de las experiencias personales de los autores, se analizan los eventos de Hannover (2000) que marca el comienzo de las exposiciones del presente siglo, Shanghái (2010), y Milán (2015) para comprender los efectos que los eventos expositivos tienen sobre la transformación de la ciudad y del territorio, en un momento en el cual existe una renovada preocupación sobre el devenir de las ciudades, s…