Search results for "L25"
showing 10 items of 15 documents
A continuous time tug-of-war game for parabolic $p(x,t)$-Laplace type equations
2019
We formulate a stochastic differential game in continuous time that represents the unique viscosity solution to a terminal value problem for a parabolic partial differential equation involving the normalized $p(x,t)$-Laplace operator. Our game is formulated in a way that covers the full range $1<p(x,t)<\infty$. Furthermore, we prove the uniqueness of viscosity solutions to our equation in the whole space under suitable assumptions.
Bhabha Scattering and a special pencil of K3 surfaces
2018
We study a pencil of K3 surfaces that appeared in the $2$-loop diagrams in Bhabha scattering. By analysing in detail the Picard lattice of the general and special members of the pencil, we identify the pencil with the celebrated Ap\'ery--Fermi pencil, that was related to Ap\'ery's proof of the irrationality of $\zeta(3)$ through the work of F. Beukers, C. Peters and J. Stienstra. The same pencil appears miraculously in different and seemingly unrelated physical contexts.
Convex functions on Carnot Groups
2007
We consider the definition and regularity properties of convex functions in Carnot groups. We show that various notions of convexity in the subelliptic setting that have appeared in the literature are equivalent. Our point of view is based on thinking of convex functions as subsolutions of homogeneous elliptic equations.
Mouse langerhans cells differentially express an activated T cell-attracting CC chemokine.
1999
Epidermal Langerhans cells represent an immature population of dendritic cells, not yet able to prime naive T cells. Following in vitro culture Langerhans cells mature into potent immunostimulatory cells. We constructed a representative cDNA library of in vitro matured murine Langerhans cells. Applying a differential screening procedure 112 differentially expressed cDNA clones were isolated. Thirty-six clones represented cDNA fragments of the same gene, identifying it to be the most actively expressed gene induced in maturing Langerhans cells. A full-length cDNA was sequenced completely. The open reading frame codes for a protein of 92 amino acids containing a leader peptide of 24 amino aci…
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…
One swallow does not make a summer: episodes and persistence in high growth
2021
This paper analyzes firms’ episodes (spells) of high growth (HG) using a sample of Spanish manufacturing firms observed over two decades. The use of duration models allows us to investigate the following: (i) the probability of experiencing HG episodes, (ii) persistence in HG, and (iii) the determinants of the transitions in and out of the HG state and whether their impact varies over the business cycle. We find that about half of the firms experience at least one HG episode, but they seldom experience more than one. Moreover, high-growth status is rarely repeated due to high first-year selection. Yet, in subsequent years beyond the first one, the hazard rate from HG status falls substantia…
On the Returns to Invention within Firms: Evidence from Finland
2018
International audience; In this paper we merge individual income data, firm-level data, patenting data, and IQ data in Finland over the period 1988–2012 to analyze the returns to invention for inventors and their coworkers or stakeholders within the same firm. We find that: (i) inventors collect only 8 percent of the total private return from invention; (ii) entrepreneurs get over 44 percent of the total gains; (iii) bluecollar workers get about 26 percent of the gains and the rest goes to white-collar workers. Moreover, entrepreneurs start with significant negative returns prior to the patent application, but their returns subsequently become highly positive.
Antecedentes y dinamismo de la ambidestreza organizativa en las pymes
2014
El objetivo de este trabajo es analizar algunos de los antecedentes de la ambidestreza organizativa en las pequenas y medianas empresas (Pymes). La ambidestreza es una capacidad dinamica que permite a las empresas obtener un elevado nivel de desempeno en situaciones que requieren alinearse con el entorno. En el trabajo se defiende que la ambidestreza tiene un componente estructural que la hace depender de los niveles previos de ambidestreza, pero que tambien tiene como antecedente las opciones de estrategia corporativa de la empresa. Concretamente, se postula que la utilizacion por parte de las empresas de las modalidades de crecimiento externo, a traves de las fusiones y adquisiciones, y d…
Learning from foreign operation modes: The virtuous path for innovation
2020
In this article, we analyze the impact of learning from internationalization on small and medium enterprises’ (SMEs) performance along different development paths. Drawing on the exploitation versus exploration logic, we use an alternative view of foreign operation modes (the learning perspective) to provide insights into the impact of such learning on technological and organizational innovation as well as overall performance. Our results, which are derived from a sample of 132 SMEs active in traditional manufacturing industries, point to a path to superior performance that entails resource-augmenting operation modes and organizational innovation. JEL CLASSIFICATION: O31; F23; L25; M10; M1…
A 1D coupled Schrödinger drift-diffusion model including collisions
2005
We consider a one-dimensional coupled stationary Schroedinger drift-diffusion model for quantum semiconductor device simulations. The device domain is decomposed into a part with large quantum effects (quantum zone) and a part where quantum effects are negligible (classical zone). We give boundary conditions at the classic-quantum interface which are current preserving. Collisions within the quantum zone are introduced via a Pauli master equation. To illustrate the validity we apply the model to three resonant tunneling diodes.