Storage of correlated patterns in a perceptron

We calculate the storage capacity of a perceptron for correlated gaussian patterns. We find that the storage capacity $\alpha_c$ can be less than 2 if similar patterns are mapped onto different outputs and vice versa. As long as the patterns are in general position we obtain, in contrast to previous works, that $\alpha_c \geq 1$ in agreement with Cover's theorem. Numerical simulations confirm the results.Comment: 9 pages LaTeX ioplppt style, figures included using eps

Correlations between hidden units in multilayer neural networks and replica symmetry breaking

We consider feed-forward neural networks with one hidden layer, tree architecture and a fixed hidden-to-output Boolean function. Focusing on the saturation limit of the storage problem the influence of replica symmetry breaking on the distribution of local fields at the hidden units is investigated. These field distributions determine the probability for finding a specific activation pattern of the hidden units as well as the corresponding correlation coefficients and therefore quantify the division of labor among the hidden units. We find that although modifying the storage capacity and the distribution of local fields markedly replica symmetry breaking has only a minor effect on the correlation coefficients. Detailed numerical results are provided for the PARITY, COMMITTEE and AND machines with K=3 hidden units and nonoverlapping receptive fields.Comment: 9 pages, 3 figures, RevTex, accepted for publication in Phys. Rev.

Multifractal analysis of perceptron learning with errors

Random input patterns induce a partition of the coupling space of a perceptron into cells labeled by their output sequences. Learning some data with a maximal error rate leads to clusters of neighboring cells. By analyzing the internal structure of these clusters with the formalism of multifractals, we can handle different storage and generalization tasks for lazy students and absent-minded teachers within one unified approach. The results also allow some conclusions on the spatial distribution of cells.Comment: 11 pages, RevTex, 3 eps figures, version to be published in Phys. Rev. E 01Jan9

Learners reconceptualising education: Widening participation through creative engagement?

This paper argues that engaging imaginatively with ways in which statutory and further education is provided and expanding the repertoire of possible transitions into higher education, is necessary for providers both in higher education and in the contexts and phases which precede study at this level. Fostering dispositions for creativity in dynamic engagement with educational technology together with the consideration of pedagogy, learning objects, inclusion, policy and the management of change, requires innovative provision to span the spaces between school, home, work and higher education learning. Reporting on The Aspire Pilot, a NESTA-funded initiative at The Open University, the paper offers the beginning of a theoretical frame for considering learning, learners and learning systems in the information age prioritizing learner agency. It will report emergent empirical findings from this inter-disciplinary project, with a significant e-dimension, which seeks to foster the creativity of 13-19 year olds in considering future learning systems, developing provocations for others to explore creative but grounded possibilities. It explores implications arising from this project for approaches that may facilitate widening participation in higher education

The Australian Farm Business Management Network: Industry, Education, Consultancy and Research Coming Together

Under the sponsorship of the University of Sydney, on 5-6th December 2002 the future of farm management in Australia was discussed. The fundamental conclusion achieved by key primary industry representatives, corporate executives, academics, consultants and researchers is that farm management will have a more significant role to play in the future than previously in servicing the primary sector. The idea of farm management as a profession was proposed. Its basis would be business management supported by farming systems and technology, and using an holistic approach to action (i.e. finance, people and environment). The new profession of Farm Business Management would seek to influence education, research, consultancy and extension in Australia. Interested parties participating of the 2002 National Farm Management Workshop came away with the idea of championing a consultative network, constituted by interested institutions and interested individuals, as a first step in the process of nurturing the future development of farm business management. By integrating farmers and academics with corporate executives, consultants and researchers the objective is to behave as a consultative group. This group will influence educational models, implement consultancy and research strategies, and network in social and professional terms. Moreover, this network will provide a systematic opportunity for the channelling of farm business management and farming systems related information at different levels for education, extension and scientific purposes. This network is called the Australian Farm Business Management Network (AFBMnetwork).Institutional and Behavioral Economics,

Do divorcing couples become happier by breaking up?

Divorce is a leap in the dark. The paper investigates whether people who split up actually become happier. Using the British Household Panel Survey, we can observe an individual's level of psychological well-being in the years before and after divorce. Our results show that divorcing couples reap psychological gains from the dissolution of their marriages. Men and women benefit equally. The paper also studies the effects of bereavement, of having dependant children and of remarriage. We measure well-being by using general health questionnaire and life satisfaction scores

Sea Floor Mapping in the Arctic: Support for a Potential US Extended Continental Shelf

For the United States, the greatest opportunity for an extended continental shelf under UNCLOS is in the ice-covered regions of the Arctic north of Alaska. Since 2003, CCOM/JHC has been using the icebreaker Healy equipped with a multibeam echosounder, chirp subbottom profiler, and dredges, to map and sample the region of Chukchi Borderland and Alpha-Mendeleev Ridge complex. These data have led to the discovery of several new features, have radically changed our view of the bathymetry and geologic history of the area, and may have important ramifica-tions for the determination of the limits of a U.S. extended continental shelf under Article 76.Para los Estados Unidos, la mayor oportunidad de extensión de la plataforma continental en el marco de la Convención de las Naciones Unidas sobre la Ley del Mar reside en las regiones cubiertas por el hielo del Artico, al Norte de Alaska. Desde el 2003, el CCOM/JHC ha estado utilizando el rompehielos Healy, equipado de un sondador acústico multihaz, un perfilador de sub-fondo por ondas moduladas en frecuencia, y de rastras, para cartografiar y muestrear la región del conjunto de ―Chukchi Borderland‖ y de la ―Alpha-Mendeleev Ridge‖. Estos datos han llevado al descubrimiento de varias nuevas formas del relieve, han cambiado radicalmente nuestra visión de la historia de la batimetría y la geología en la zona, y pueden tener importantes ramificaciones para la determinación de los límites de la plataforma continental estadounidense ampliada en el marco del Artículo 76.En ce qui concerne les Etats-Unis, la plus grande possibilité d‘extension du plateau continental dans le cadre de la Convention des Nations Unies sur le droit de la mer réside dans les régions englacées de l‘Arctique, au nord de l‘Alaska. Depuis 2003, le CCOM/JHC a utilisé le brise-glace HEALY, équipé d‘un sondeur multifaisceaux, d‘un sondeur de sédiment chirp et de dragues, pour cartographier et échantillonner la région de l‘ensemble « Chukchi Borderland » et de l‘« Alpha-Mendeleev Ridge ». Ces données ont conduit à la découverte de plusieurs nouveaux éléments, ont changé radicalement nos points de vue sur l‘histoire de la bathymétrie et de la géologie dans la zone et peuvent avoir des ramifications importantes en ce qui concerne la détermination des limites du plateau continental étasunien étendu dans le cadre de l‘Article 76

Bistability in a simple fluid network due to viscosity contrast

We study the existence of multiple equilibrium states in a simple fluid network using Newtonian fluids and laminar flow. We demonstrate theoretically the presence of hysteresis and bistability, and we confirm these predictions in an experiment using two miscible fluids of different viscosity--sucrose solution and water. Possible applications include bloodflow, microfluidics, and other network flows governed by similar principles