Search results for "decoupling"
showing 10 items of 87 documents
A universal definition of life: autonomy and open-ended evolution.
2004
Life is a complex phenomenon that not only requires individual self-producing and self- sustaining systems but also a historical-collective organization of those individual systems, which brings about characteristic evolutionary dynamics. On these lines, we propose to define univer- sally living beings as autonomous systems with open-ended evolution capacities, and we claim that all such systems must have a semi-permeable active boundary (membrane), an energy trans- duction apparatus (set of energy currencies) and, at least, two types of functionally interdependent macromolecular components (catalysts and records). The latter is required to articulate a 'phenotype- genotype' decoupling that…
Le débat macroévolutif : apports de la disparité morphologique
2003
Resume La theorie macroevolutive est abordee sous des aspects historiques, puis sous un de ses aspects plus novateurs, qui aboutit a l’elaboration d’un programme de recherche initie par differentes equipes depuis une dizaine d’annees : il consiste a decoupler les composantes taxinomiques (diversite) et morphologiques (disparite) de la biodiversite, lors de l’etude de ses fluctuations. Plusieurs etudes suggerent des decouplages temporels frequents entre ces deux metriques au cours de l’histoire des clades. La confrontation des deux apparait comme une demarche feconde qui a permis d’explorer en termes de patterns , mais egalement de processus, les fluctuations de la biodiversite a large echel…
Analytic energy gradients for the spin-free exact two-component theory using an exact block diagonalization for the one-electron Dirac Hamiltonian.
2011
We report the implementation of analytic energy gradients for the evaluation of first-order electrical properties and nuclear forces within the framework of the spin-free (SF) exact two-component (X2c) theory. In the scheme presented here, referred to in the following as SFX2c-1e, the decoupling of electronic and positronic solutions is performed for the one-electron Dirac Hamiltonian in its matrix representation using a single unitary transformation. The resulting two-component one-electron matrix Hamiltonian is combined with untransformed two-electron interactions for subsequent self-consistent-field and electron-correlated calculations. The "picture-change" effect in the calculation of p…
Decoupling of HRM as health sector regulation
2022
This systematic review of the academic literature since early 1990s on the application of some HRM practices in health care sheds light on the persistence decoupling between institutional norms and standards related to human resource management (HRM) procedures and the actual practices in organizations. Contrary to the affirmation of NIT, translation processes do not put an end to decoupling. The isomorphisms identified by the neo institutionalists relate to leadership decisions, not practices. The application of HRM practice bundles is opposed by health care professionals. This analysis of the «critical» approach is apparently contradicted by that which we describe as «optimistic» because …
Simplifying differential equations for multi-scale Feynman integrals beyond multiple polylogarithms
2017
In this paper we exploit factorisation properties of Picard-Fuchs operators to decouple differential equations for multi-scale Feynman integrals. The algorithm reduces the differential equations to blocks of the size of the order of the irreducible factors of the Picard-Fuchs operator. As a side product, our method can be used to easily convert the differential equations for Feynman integrals which evaluate to multiple polylogarithms to $\varepsilon$-form.
Renormalization, running couplings, and decoupling for the Yukawa model in a curved spacetime
2021
The decoupling of heavy fields as required by the Appelquist-Carazzone theorem plays a fundamental role in the construction of any effective field theory. However, it is not a trivial task to implement a renormalization prescription that produces the expected decoupling of massive fields, and it is even more difficult in curved spacetime. Focused on this idea, we consider the renormalization of the one-loop effective action for the Yukawa interaction with a background scalar field in curved space. We compute the beta functions within a generalized DeWitt-Schwinger subtraction procedure and discuss the decoupling in the running of the coupling constants. For the case of a quantized scalar fi…
Vibrational Signature of Water Molecules in Asymmetric Hydrogen Bonding Environments
2013
The O–H stretching vibrational modes of water molecules are sensitive to their local environments. Here, we applied effective normal-mode analysis to isolate contributions of each of the two hydrogen atoms to the vibrational modes ν1 and ν3 of water molecules in the liquid phase. We demonstrate that the decoupling of the two contributions fd and the frequency splitting of the vibrational modes Δω13 are inextricably related to the symmetry of the hydrogen bonding environment. We show that ambient liquid water modeled at the density functional level of theory exhibits the characteristics of an asymmetric environment with an average decoupling of 0.82 and a splitting of 137 inverse centimeters…
Visual Servoing Based on Shifted Moments
2015
Over the past decade, image moments have been exploited in several visual servoing schemes for their ability to represent object regions, objects defined by contours or a set of discrete points. Moments have also been useful to achieve control decoupling properties and to choose a minimal number of features to control the whole degrees of freedom (DOFs) of a camera. However, the choice of moment-based features to control the rotational motions around the $x$ -axis and $y$ -axis simultaneously with the translational motions along the same axis remains a key issue. In this paper, we introduce new visual features computed from low-order “shifted moments invariant.” Importantly, they allow us 1…
Dark matter from gravitational particle production at reheating
2015
We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses $m$ and non-minimal coupling values $\xi$. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for $m\sim 0.1$ GeV and $\xi \sim 1$. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.
On-Surfaces Synthesis on Insulating Substrates
2016
On-surface synthesis has attracted great attention in recent years due to its promising potential for creating functional structures on surfaces. An important aspect of on-surface synthesis is the capability to arrive at covalently linked thermally stable structures that offer the possibility for application even in harsh environments outside ultra-high vacuum conditions. Additionally, covalent linking allows for fabricating conjugated structures with superior electron transport properties. Especially, the latter is of tremendous interest when considering future applications in the field of molecular electronics. Having molecular electronics applications in mind explains the need for decoup…