Search results for "VARIATION"
showing 10 items of 2124 documents
An international cohort comparison of size effects on job growth
2015
The contribution of different-sized businesses to job creation continues to attract policymakers’ attention, however, it has recently been recognized that conclusions about size were confounded with the effect of age. We probe the role of size, controlling for age, by comparing the cohorts of firms born in 1998 over their first decade of life, using variation across half a dozen northern European countries Austria, Finland, Germany, Norway, Sweden, and the UK to pin down size effects. We find that a very small proportion of the smallest firms play a crucial role in accounting for cross-country differences in job growth. A closer analysis reveals that the initial size distribution and surviv…
The Merits of Playing It by the Book: Routine versus Deliberate Learning and the Development of Dynamic Capabilities
2018
In this study, we investigate the nature of dynamic capabilities and use a fine-grained measurement to test how centralization, routinization, and formalization relate to the underlying learning components of dynamic capabilities. We find that the effects of our three dimensions of managerial practices are broadly similar for almost all components of dynamic capabilities, and that only a few show a different pattern. Centralization and routinization are negatively related to dynamic capabilities, formalization is shown to have a significantly positive effect. We provide insights into the role of three dimensions of managerial practice by explaining variation among the learning components of…
Is traditional teaching really all that bad? A within-student between-subject approach
2011
Abstract Recent studies conclude that teachers are important for student learning but it remains uncertain what actually determines effective teaching. This study directly peers into the black box of educational production by investigating the relationship between lecture style teaching and student achievement. Based on matched student–teacher data for the US, the estimation strategy exploits between-subject variation to control for unobserved student traits. Results indicate that traditional lecture style teaching is associated with significantly higher student achievement. No support for detrimental effects of lecture style teaching can be found even when evaluating possible selection bia…
Cross-country variation in patience, persistent current account imbalances and the external wealth of nations
2022
This paper is the first to utilize large-scale international surveys on economic preferences to examine the long-run relationships between patience, current accounts and external wealth. We find robust empirical evidence that countries with more patient individuals tend to run persistent current account surpluses, which in turn result in the accumulation of foreign assets. This theoretically plausible but empirically unexplored relationship holds true for euro area current account imbalances, global current account imbalances and net foreign asset positions worldwide. While the existing current account literature concentrates on proximate macroeconomic determinants, this paper’s extension o…
Deconstrucción del “buen profesor”. Análisis de las características formales y no formales de la docencia universitaria
2016
Antecedentes: la evaluación de la calidad del profesorado universitario, desde el punto de vista del alumnado, se ha centrado principalmente en los aspectos más formales del ejercicio docente, desatendiendo así otros factores de tipo personal. Objetivo: identificar y analizar las cargas de cada uno de los distintos factores que conforman la idea de la buena docencia según el alumnado. Es decir, detectar la ecuación que da lugar al esquema mental de “buen profesor” o “buena profesora”. Método: encuesta transversal, elaborada a partir de los resultados de revisiones e investigaciones propias que permitieron conocer la identidad de los distintos factores implicados en la evaluación de la doce…
Analysis and optimization against buckling of beams interacting with elastic foundation
2017
We consider an infinite continuous elastic beam that interacts with linearly elastic foundation and is under compression. The problem of the beam buckling is formulated and analyzed. Then the optimization of beam against buckling is investigated. As a design variable (control function) we take the parameters of cross-section distribution of the beam from the set of periodic functions and transform the original problem of optimization of infinite beam to the corresponding problem defined at the finite interval. All investigations are on the whole founded on the analytical variational approaches and the optimal solutions are studied as a function of problems parameters. peerReviewed
A method of variation of boundaries for waveguide grating couplers
2008
We describe a method for calculating the solution of the electromagnetic field in a non-rectilinear open waveguide by using a series expansion, starting from the field of a rectilinear waveguide. Our approach is based on a method of variation of boundaries. We prove that the obtained series expansion converges and we provide a radiation condition at infinity in such a way that the problem has a unique solution. Our approach can model several kinds of optical devices which are used in optical integrated circuits. Numerical examples will be shown for the case of finite aperiodic waveguide grating couplers.
The Contingent Negative Variation – An Electrophysiological Correlate of Temporal Processing or Reference Memory?
2014
Abstract In EEG research, the contingent negative variation (CNV) is considered to be strongly related to interval timing (e.g., Macar & Vidal, 2004 ; Macar, Vidal, & Casini, 1999). However, it is discussed controversially whether certain properties of the CNV (e.g., amplitude, peak latency and resolution) directly reflect the process of temporal accumulation or rather processes related to reference memory or decision stages in temporal information processing (van Rijn et al., 2011). This present study was designed in order to investigate the relationship between CNV mean amplitude, CNV resolution, and memory processes as well as processes of temporal accumulation. The task design aimed at …
Optimization of the domain in elliptic variational inequalities
1988
This paper is concerned with a nonsmooth shape optimization problem for the Signorini unilateral boundary-value problem. The necessary optimality conditions are derived. The results of computations are presented.
Least energy solutions to the Dirichlet problem for the equation −D(u) = f (x, u)
2017
Let be a bounded smooth domain in RN. We prove a general existence result of least energy solutions and least energy nodal ones for the problem −u = f(x, u) in u = 0 on ∂ (P) where f is a Carathéodory function. Our result includes some previous results related to special cases of f . Finally, we propose some open questions concerning the global minima of the restriction on the Nehari manifold of the energy functional associated with (P) when the nonlinearity is of the type f(x, u) = λ|u| s−2u − μ|u| r−2u, with s, r ∈ (1, 2) and λ,μ > 0.