Search results for "boundary"

Optimal Control for Plate Problems

2003

The variational approach leading to indirect methods Optimal Control Problems is applied to the study of simply supported and clamped plates. A unified approach based on distributed optimal control problems governed by second order elliptic boundary value problems and their penalization is used.

The Dynamics of (De)Stigmatization : Boundary construction in the nascent category of organic farming

2020

This study finds that it is possible for organizations in emerging categories to resist stigmatization through discursive reconstruction of the central and distinctive characteristics of the category in question. We examined the emerging market of organic farming in Finland and discovered how resistance to stigmatization was both an internal and an external power struggle in the organic farming community. Over time, the label of organic farming was manipulated and the practice of farming was associated with more conventional and familiar contexts, while the stigma was diverted at the same time to biodynamic farming. We develop a process model for removal of stigma from a nascent category t…

Balancing on a tightrope: Managing the boundaries of a firm-sponsored OSS community and its impact on innovation and absorptive capacity

2014

Realizing the innovation potential of OSS communities, firms now create or sponsor their own open source software (OSS) communities, generally as part of an open innovation strategy. However, maximizing the innovation capability of a sponsored OSS community is a challenging task since firms cannot rely on traditional hierarchical authority to control community members. Furthermore, a firm's efforts to manage its sponsored community may also impact the firm's absorptive capacity, or its ability to effectively absorb and leverage the valuable knowledge created by the community. Thus, the purpose of this article is to investigate two research questions: 1) How does the boundary management of a…

On a singular boundary value problem for a second order ordinary differential equation

2000

Numerische Behandlung von Verzweigungsproblemen bei gew�hnlichen Differentialgleichungen

1979

We present a new method for the numerical solution of bifurcation problems for ordinary differential equations. It is based on a modification of the classical Ljapunov-Schmidt-theory. We transform the problem of determining the nontrivial branch bifurcating from the trivial solution into the problem of solving regular nonlinear boundary value problems, which can be treated numerically by standard methods (multiple shooting, difference methods).

A note on an overdetermined problem for the capacitary potential

2016

We consider an overdetermined problem arising in potential theory for the capacitary potential and we prove a radial symmetry result.

Displacement measurement through DIC and DSPI techniques in cold-expanded holes

2008

In this paper, the displacement field induced by the split-sleeve cold expansion of holes was measured using both digital image correlation (DIC) and digital speckle pattern interferometry (DSPI) techniques. Thus, the experimental results, which were evaluated on the inlet surface of a 6082-T6 aluminium plate, were compared with those from theoretical prediction. DIC provided accurate measurements up to the elastic-plastic boundary, whereas the DSPI technique highlighted the changes of displacement in the elastic domain. Prediction of the displacement based on the existing analytical model agreed with the experimental results achieved with both techniques. Possible explanations for the diff…

Hydrodynamics of the cocurrent downflow of a gas and a foaming liquid through a packed bed. Part I. Estimation of the transition boundary between the…

2004

Abstract In the study the results of investigations are presented aimed at determining such values of the operating parameters for which the change of the hydrodynamic regime occurs from the gas continuous flow (GCF) to the pulsing flow (PF). Nitrogen, helium and argon were used as the gas phase while the liquid phase was formed by the aqueous solutions of the alcohols C 1 –C 4 of the concentrations which ensured the foaming of the system. Thus a wide range of physicochemical properties of the system was covered in the experiments. The present study, as well as Part II, contain a wealth of experimental data which characterise the PF through the packing for the foam-forming systems. It is de…

Hydrodynamics of a cocurrent downflow of gas and foaming liquid through the packed bed. Part II. Liquid holdup and gas pressure drop

2003

Abstract In the present study the results of experiments have been presented whose aim was to determine the values of liquid holdup as well as gas pressure drop through the packing for systems foaming under the pulse flow regime. On the basis of 245 experimental points for the pulse flow regime the verification of the models describing the hydrodynamics of the system has been performed. Attention was focused on the models of Benkrid et al. (Chem. Eng. Sci. 52 (1997) 4021), Pina et al. (AIChE J. 47 (2001) 19) and Fourar et al. (Chem. Eng. Sci. 56 (2001) 5987). It has been concluded that none of the models analysed describes the hydrodynamics of the foaming systems with enough accuracy. Next,…

Analysis of a Parabolic Cross-Diffusion Semiconductor Model with Electron-Hole Scattering

2007

The global-in-time existence of non-negative solutions to a parabolic strongly coupled system with mixed Dirichlet–Neumann boundary conditions is shown. The system describes the time evolution of the electron and hole densities in a semiconductor when electron-hole scattering is taken into account. The parabolic equations are coupled to the Poisson equation for the electrostatic potential. Written in the quasi-Fermi potential variables, the diffusion matrix of the parabolic system contains strong cross-diffusion terms and is only positive semi-definite such that the problem is formally of degenerate type. The existence proof is based on the study of a fully discretized version of the system…