Time-dependent angularly averaged inverse transport

This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain

Inverse Transport Theory of Photoacoustics

We consider the reconstruction of optical parameters in a domain of interest from photoacoustic data. Photoacoustic tomography (PAT) radiates high frequency electromagnetic waves into the domain and measures acoustic signals emitted by the resulting thermal expansion. Acoustic signals are then used to construct the deposited thermal energy map. The latter depends on the constitutive optical parameters in a nontrivial manner. In this paper, we develop and use an inverse transport theory with internal measurements to extract information on the optical coefficients from knowledge of the deposited thermal energy map. We consider the multi-measurement setting in which many electromagnetic radiation patterns are used to probe the domain of interest. By developing an expansion of the measurement operator into singular components, we show that the spatial variations of the intrinsic attenuation and the scattering coefficients may be reconstructed. We also reconstruct coefficients describing anisotropic scattering of photons, such as the anisotropy coefficient $g(x)$ in a Henyey-Greenstein phase function model. Finally, we derive stability estimates for the reconstructions

A Game Engine based Networked Infrastructure to Create and Share 3D Abstract Art

Online communities have been proactive in producing collaborative creative content such as music, games and other social interactions. Online collaboration has enabled contributors to peer produce and share masses of creative content. Examples range from information sharing such as Wikipedia to open source software and other specific art projects. Software vendors have recently introduced low cost 2D and 3D content authoring tools allowing user communities to generate and share creative content. Emerging networking programming interfaces available inside modern game engines allow contributors to implement multiplayer or multiuser interaction relatively easily. This paper presents a 3D art creation framework to be used over networked infrastructure in a multiuser environment. Contributors will be able to create 3D sculptures at runtime, share with other users in a common networked working environment and critique each other’s work. Experimental work also involved evaluating procedurally generated meshes versus instantiation of primitive mesh objects. Saving and loading mesh information in an optimum way is also explored

Why do employees negotiate idiosyncratic deals? An exploration of the process of i-deal negotiation

This study investigated why employees negotiate idiosyncratic deals with their organizations, and interviews with 31 employees who successfully negotiated i-deals showed that three main themes could be identified in the i-deal negotiation process: motives for negotiating (i.e., earned and problem solving), enablers (i.e., relationships and flexibility), and inhibitors (i.e., secrecy, and culture and structure). The study shows that people may have different motives for negotiating i-deals, and subsequently also experience different enabling and inhibiting factors in the process of obtaining i-deals

Het psychologisch contract tussen oudere werknemers en de organisatie.

Door recente reorganisaties binnen en fusies en overnames tussen organisaties veranderen de relaties tussen werkgevers en werknemers drastisch. De oude relatie tussen werkgevers en werknemers die bestond uit de (impliciete) belofte van de werkgever om een werknemer voor de duur van een loopbaan aan te nemen in ruil voor loyaliteit en hard werken, is voorbij. Werkgevers bieden in mindere mate de zekerheid van een vast contract, en gaan meer over op tijdelijke contracten. Hierdoor ontstaat een nieuwe relatie tussen werkgever en werknemer. Om de impliciete onderdelen van deze relatie te beschrijven is de term ‘psychologisch contract’ geïntroduceerd. In dit artikel wordt uitgelegd wat het psychologisch contract is, en welke relaties het psychologisch contract heeft met gedrag en organisatie-uitkomsten. Verder wordt ingegaan op de vraag waar het psychologisch contract voor gebruikt kan worden in organisaties, met name met het oog op vergrijzing van de arbeidsmarkt

Voorbij neoliberalisme in de arbeids- en organisatiepsychologie: Menselijke waardigheid en organisatiedemocratie

In this article, I explore the relation between neoliberalism and work and organizational psychology. This article explains how the neoliberal paradigm has influenced the way research is conducted in the field of work and organizational psychology. The article continues by providing an alternative paradigm based on human dignity, which is translated into the concept of organizational democracy. The article finishes with the implications of the human dignity paradigm for research in the field of work and organizational psychology, as well as with an agenda for future research on the new paradigm

Post-pensionados. Hoe worden 65-plussers gemotiveerd om te werken?

Nu de vergrijzing begint toe te slaan en organisaties steeds meer moeite moeten doen om goed gekwalificeerd personeel te werven en te behouden, wordt het aanspreken van onze stille arbeidsreserve steeds belangrijker. 65-plussers vormen een interessante groep potentiële werknemers. Ze zijn vaak ervaren, gedreven en loyaal, en zijn graag bereid zich flexibel op te stellen als de werkgever oog heeft voor hun specifieke behoeften

Phase Space Models for Stochastic Nonlinear Parabolic Waves: Wave Spread and Singularity

We derive several kinetic equations to model the large scale, low Fresnel number behavior of the nonlinear Schrodinger (NLS) equation with a rapidly fluctuating random potential. There are three types of kinetic equations the longitudinal, the transverse and the longitudinal with friction. For these nonlinear kinetic equations we address two problems: the rate of dispersion and the singularity formation. For the problem of dispersion, we show that the kinetic equations of the longitudinal type produce the cubic-in-time law, that the transverse type produce the quadratic-in-time law and that the one with friction produces the linear-in-time law for the variance prior to any singularity. For the problem of singularity, we show that the singularity and blow-up conditions in the transverse case remain the same as those for the homogeneous NLS equation with critical or supercritical self-focusing nonlinearity, but they have changed in the longitudinal case and in the frictional case due to the evolution of the Hamiltonian