Search results for "Instability"
showing 10 items of 724 documents
From 2009 to 1929
2010
The current and still unfolding crisis of our economic system shows disturbing resemblances to the Great Depression in terms of magnitude, triggering mechanisms, and curative public interventions. This paper compares the experience, mechanisms, and consequences of these two crises in light of the analysis of Fisher, Keynes, and Minsky. This analysis proves very useful for understanding the triggering mechanisms of the current crisis, as well as its propagation mechanisms. It also addresses two dilemmas within the debate about the curative as well as preventive measures for getting out of the crisis and avoiding a new disaster: the dilemma of monetary activism and that of liquidity.
Die kinetik der allendimerisation, ein beitrag zum mechanismus
1971
Zusammenfassung The reaction kinetics of the dimerization of some polyhalogenated allenes with the general formula Cl2CCCCIX (X = Cl, Br, C6H5, COOEt) and of tetrabromoallene was studied by an IR spectrophotometric method. The reaction was found to be of strictly second order kinetics. The activation parameters were determined and the experimental data and the influence of the substituents were discussed in terms of the accepted general theory of allene cycloaddition. All data are in agreement with a non-concerted two-step electrocyclic addition mechanism. Within the experimental limits no paramagnetic species like a diradical could be detected by the ESR-method during the dimerization re…
Energy localization in a nonlinear discrete system
1996
International audience; We show that, in the weak amplitude and slow time limits, the discrete equations describing the dynamics of a one-dimensional lattice can be reduced to a modified Ablowitz-Ladik equation. The stability of a continuous wave solution is then investigated without and with periodic boundary conditions; Energy localization via modulational instability is predicted. Our numerical simulations, performed on a cyclic system of six oscillators, agree with our theoretical predictions.
Modulational instability and two-dimensional dynamical structures
2008
A process of nonlinear structure formation on a two-dimensional lattice is proposed. The basic model consists of a two-dimensional lattice equipped at each node with a molecule or dipole rotating in the lattice plane. The interactions involved in the model are reduced to a periodic lattice. Such a discrete system can be applied to the problem of molecule adsorption on a substrate crystal surface, for instance. The continuum approximation of the model leads to a 2-D sine-Gordon system including nonlinear couplings, which itself can be reduced to a 2-D nonlinear Schrodinger equation in the low amplitude limit. Spatio-temporal structure formation is investigated by means of numerical simulatio…
Dissipative rogue wave generation in multiple-pulsing mode-locked fiber laser
2013
Following the first experimental observation of a new mechanism leading to optical rogue wave (RW) formation briefly reported in Lecaplain et al (2012 Phys. Rev. Lett. 108 233901), we provide an extensive study of the experimental conditions under which these RWs can be detected. RWs originate from the nonlinear interactions of bunched chaotic pulses that propagate in a fiber laser cavity, and manifest as rare events of high optical intensity. The crucial influence of the electrical detection bandwidth is illustrated. We also clarify the observation of RWs with respect to other pulsating regimes, such as Q-switching instability, that also lead to L-shaped probability distribution functions.…
Parenting Styles, Prosocial, and Aggressive Behavior: The Role of Emotions in Offender and Non-offender Adolescents
2017
The aim is to analyse the parenting styles effects (acceptance, negative control and negligence) on prosociality and aggressive behavior in adolescents through the mediator variables empathy and emotional instability, and also, if this model fits to the same extent when we study adolescents institutionalized due to problems with the law and adolescents from the general population, and at the same time, if the values of the different analyzed variables are similar in both groups of adolescents. We carried out a cross-sectional study. 220 participants from schools in the metropolitan area of Valencia took part in the study. Also, 220 young offenders took part recruited from four Youth Detenti…
Re-Emerging Vaccine-Preventable Diseases in War-Affected Peoples of the Eastern Mediterranean Region—An Update
2017
For the past few decades, the Eastern Mediterranean Region has been one area of the world profoundly shaped by war and political instability. On-going conflict and destruction have left the region struggling with innumerable health concerns that have claimed the lives of many. Wars, and the chaos they leave behind, often provide the optimal conditions for the growth and re-emergence of communicable diseases. In this article, we will highlight three of the major re-emerging vaccine preventable diseases cholera, measles, and polio, in four countries of the Eastern Mediterranean Region that are currently affected by war leading to a migration crisis: Iraq, South Sudan, Syria, and Yemen. The re…
Investment–productivity dynamics and distribution dynamics in a multisector economy: some theory and an application to Italian regions
2003
Abstract In this paper, we study the investment–productivity dynamics in the Framework Space, presented by Bohm and Punzo [Cycles, Growth and Structural Change, Routledge, London (2001) 47], as the distribution dynamics of the production sectors of an economy. We apply such theoretical framework to data from Italian regions to identify differences in sectoral behaviors both within and across regions. Our main findings are: sectors within a region generally follow different regime dynamics; Southern Italian regions are generally characterized by higher degrees of heterogeneity in sectoral growth behaviors and of regime instability. Also, we find support to the hypothesis of a positive relati…
Spillovers through banking centers: a panel data analysis of bank flows
2003
Abstract This paper presents evidence that spillovers through bank lending contributed to the transmission of currency crises during the recent episodes of financial instability in emerging markets. The innovation of the paper is that it looks beyond aggregated measures of contagion into the structure of bank flows, disaggregating by banking centers. The main findings are that spillovers caused by banks’ exposures to a crisis country help predict flows in third countries after the Mexican and Asian crises, but not after the Russian crisis. In the latter, there is evidence of a generalized outflow from emerging markets. The importance of spillovers through banking centers suggests that count…
Instability tests in cointegration relationships. An application to the term structure of interest rates
2002
Abstract This paper tries to review, from a practitioner's point of view, the recent strand of literature on cointegration tests allowing for structural changes or parameter instability. Thus, we apply several tests using as an example the expectations model of the term structure of interest rates. The results are consistent with the existence of cointegration between the long and the short run Spanish interest rates, with a vector (1,−1), as predicted by the theory. However, there is also evidence of structural instability, mainly at the beginning of 1994, that can be attributed to the financial changes that occurred in Spain as a result of its external commitments in the process of the Eu…