21,926 research outputs found
Monoidal categorifications of cluster algebras of type A and D
In this note, we introduce monoidal subcategories of the tensor category of
finite-dimensional representations of a simply-laced quantum affine algebra,
parametrized by arbitrary Dynkin quivers. For linearly oriented quivers of
types A and D, we show that these categories provide monoidal categorifications
of cluster algebras of the same type. The proof is purely
representation-theoretical, in the spirit of [arXiv:0903.1452].Comment: 15 pages ; to appear in the proceedings of the Conference Symmetries,
Integrable systems and Representation
Designing intelligent computer‐based simulations: A pragmatic approach
This paper examines the design of intelligent multimedia simulations. A case study is presented which uses an approach based in part on intelligent tutoring system design to integrate formative assessment into the learning of clinical decision‐making skills for nursing students. The approach advocated uses a modular design with an integrated intelligent agent within a multimedia simulation. The application was created using an object‐orientated programming language for the multimedia interface (Delphi) and a logic‐based interpreted language (Prolog) to create an expert assessment system. Domain knowledge is also encoded in a Windows help file reducing some of the complexity of the expert system. This approach offers a method for simplifying the production of an intelligent simulation system. The problems developing intelligent tutoring systems are examined and an argument is made for a practical approach to developing intelligent multimedia simulation systems
Visual ageing of human faces in three dimensions using morphable models and projection to latent structures
We present an approach to synthesising the effects of ageing on human face images using three-dimensional modelling. We extract a set of three dimensional face models from a set of two-dimensional face images by fitting a Morphable Model. We propose a method to age these face models using Partial Least Squares to extract from the data-set those factors most related to ageing. These ageing related factors are used to train an individually weighted linear model. We show that this is an effective means of producing an aged face image and compare this method to two other linear ageing methods for ageing face models. This is demonstrated both quantitatively and with perceptual evaluation using human raters.Postprin
Image denoising by statistical area thresholding
Area openings and closings are morphological filters which efficiently
suppress impulse noise from an image, by removing small connected components of
level sets. The problem of an objective choice of threshold for the area
remains open. Here, a mathematical model for random images will be considered.
Under this model, a Poisson approximation for the probability of appearance of
any local pattern can be computed. In particular, the probability of observing
a component with size larger than in pure impulse noise has an explicit
form. This permits the definition of a statistical test on the significance of
connected components, thus providing an explicit formula for the area threshold
of the denoising filter, as a function of the impulse noise probability
parameter. Finally, using threshold decomposition, a denoising algorithm for
grey level images is proposed
Building sustainability on deep values through mindfulness nurturing
To effectively pursue sustainability, companies need to develop an awareness of the importance of social and environmental objectives in addition to economic. To achieve this, they need to promote a set of shared values in their strategy and cultural change which align global sustainability with organisational performance. To assist organisations with this process and thus identify and nurture their members’ underpinning values, we present the Organisational Presence Model including a Real Dialogue Methodology. We draw on Lewin’s participative approach to change and the deep concept of Mindfulness related to Buddhist precepts, while contributing with a way to initiate Mindfulness nurturing in business context, facilitating its acceptance and practice by organizational members. In our study case we find signs of positive effects of the model in sustainability pursuing. The new strategy has been built aligned with resulting values, that are also perceived by organizational members as inspirational, generating motivation and helping the effective communication that integrates the strategic objectives in the economic, social and environmental aspects
Environmental Regulation and the Eco-industry
This paper re-examines environmental regulation, under the assumption that pollution abatement technologies and services are provided by an imperfectly competitive environment industry. It is shown that each regulatory instrument (emission taxes and quotas; design standards; and voluntary agreements) has a specific impact on the price-elasticity of the polluters’ demand for abatement services, hence on the market power of the eco-industry and the resulting cost of abatement. This implies that the optimal pollution tax will be higher than the marginal cost of pollution damage, while a voluntary approach to pollution abatement may fail unless the eco-industry itself is properly regulated. Cet article reconsidère la réglementation environnementale, sous l'hypothèse que les technologies et services de réduction de la pollution sont offerts par des entreprises spécialisées formant un oligopole. On y montre que chaque approche réglementaire (taxes et quotas sur les émissions polluantes, normes techniques, ou approches volontaires) a un impact particulier sur l'élasticité-prix de la demande de services en dépollution, donc sur le pouvoir de marché de l'éco-industrie et les coûts de réduction de la pollution. Ceci entraîne, entre autres, qu'une taxe optimale sur les émissions devrait être supérieure au coût marginal des dommages associés à celles-ci, tandis qu'une approche volontaire de réduction des émissions polluantes peut se révéler inopérante si les pratiques de marché de l'éco-industrie ne sont pas elles-mêmes correctement réglementées.pollution regulation, end-of-pipe pollution abatement, environment industry, régulation de la pollution, réduction en bout de chaîne de la pollution, industries environnementales
- …