A spherical Hopfield model

We introduce a spherical Hopfield-type neural network involving neurons and patterns that are continuous variables. We study both the thermodynamics and dynamics of this model. In order to have a retrieval phase a quartic term is added to the Hamiltonian. The thermodynamics of the model is exactly solvable and the results are replica symmetric. A Langevin dynamics leads to a closed set of equations for the order parameters and effective correlation and response function typical for neural networks. The stationary limit corresponds to the thermodynamic results. Numerical calculations illustrate our findings.Comment: 9 pages Latex including 3 eps figures, Addition of an author in the HTML-abstract unintentionally forgotten, no changes to the manuscrip

Clustering transition in a system of particles self-consistently driven by a shear flow

We introduce a simple model of active transport for an ensemble of particles driven by an external shear flow. Active refers to the fact that the flow of the particles is modified by the distribution of particles itself. The model consists in that the effective velocity of every particle is given by the average of the external flow velocities felt by the particles located at a distance less than a typical radius, $R$. Numerical analysis reveals the existence of a transition to clustering depending on the parameters of the external flow and on $R$. A continuum description in terms of the number density of particles is derived, and a linear stability analysis of the density equation is performed in order to characterize the transitions observed in the model of interacting particles.Comment: 11 pages, 2 figures. To appear in PR

Von Neumann Regular Cellular Automata

For any group $G$ and any set $A$, a cellular automaton (CA) is a transformation of the configuration space $A^G$ defined via a finite memory set and a local function. Let $\text{CA}(G;A)$ be the monoid of all CA over $A^G$. In this paper, we investigate a generalisation of the inverse of a CA from the semigroup-theoretic perspective. An element $\tau \in \text{CA}(G;A)$ is von Neumann regular (or simply regular) if there exists $\sigma \in \text{CA}(G;A)$ such that $\tau \circ \sigma \circ \tau = \tau$ and $\sigma \circ \tau \circ \sigma = \sigma$, where $\circ$ is the composition of functions. Such an element $\sigma$ is called a generalised inverse of $\tau$. The monoid $\text{CA}(G;A)$ itself is regular if all its elements are regular. We establish that $\text{CA}(G;A)$ is regular if and only if $\vert G \vert = 1$ or $\vert A \vert = 1$, and we characterise all regular elements in $\text{CA}(G;A)$ when $G$ and $A$ are both finite. Furthermore, we study regular linear CA when $A= V$ is a vector space over a field $\mathbb{F}$; in particular, we show that every regular linear CA is invertible when $G$ is torsion-free elementary amenable (e.g. when $G=\mathbb{Z}^d, \ d \in \mathbb{N}$) and $V=\mathbb{F}$, and that every linear CA is regular when $V$ is finite-dimensional and $G$ is locally finite with $\text{Char}(\mathbb{F}) \nmid o(g)$ for all $g \in G$.Comment: 10 pages. Theorem 5 corrected from previous versions, in A. Dennunzio, E. Formenti, L. Manzoni, A.E. Porreca (Eds.): Cellular Automata and Discrete Complex Systems, AUTOMATA 2017, LNCS 10248, pp. 44-55, Springer, 201

CYBORG GENESIS

We are currently living in an artificial, increasingly complex created system of discourse heavily base on socially constructed systems of language and digital technologies. How we use these technologies to advance the human condition in terms of our very existence makes us inherently cyborg in nature. With the increase in digital technologies in every aspect of day –to-day existence from your morning coffee to higher education, we have become increasingly dependent on our cyborg identities. This thesis, then, serves as a project that looks to understand how we have come to this point and to what extent our newly found cyborg identities can serve as the catalyst for progress particularly in education and the further production and transmission of human knowledge

How participatory is participatory development? : a review of the Philippine experience

About two-thirds of the Philippine population reside in the rural areas, earning an average family income of only half of their urban counterparts. It is, therefore, not surprising that much interest has been expressed in the progress of rural development strategies,the impact they have had on rural communities, the means by which they can be made more effective, and the various alternatives that exist. This timely book by Gelia Castillo deals with a number of contemporary and, to some extent, controversial issues regarding Philippine rural development. More specifically, it looks into two important aspects of rural development, namely: rural institutions and people's participation. The former is about institutional changes in the rural areas : changes in the way things are being done, as well as changes in social organization and in the relationships among the actors in that setting.Whether these changes are deliberately designed and created, e.g., Samahang Nayon, Masagana99, compact farms, etc., or result spontaneously from social, economic and political changesthat take place over time, e.g., the relationships between farmer and hired farm labor, and between landlord and tenant, they nonetheless form part and parcel of the Philippine rural setting. Thus, to fully understand rural development in the country, one must appreciate these institutional changes. The other aspect of rural development which Castillo examines is that of people's participation. Who should participate? Who are "the people"? Are they interested in participating? What constitutes participation? Does participation make a difference? What experience have we had in the practice of people's participation? These are some of the questions that the author grapples with in her work. The coverage alone, as well as the complexity of the issues involved, suggests how courageous the author had been in venturing into this study. Her work demanded that she personally sieve through volumes upon volumes of research reports,,evaluative studies, surveys, graduate theses, etc., organize their findings into an integrated, readable form, and derive insights from many otherwise apparently innocent observations. Through this book, the author has done for us a great service. Not only do we now have access to the results of scattered studies on important aspects of rural development in the country. We can also appreciate them from the vantage point the author has taken, as well as enjoy her fluid, thought-provoking and insightful style. Gelia Castillo has, indeed, made another valuable contribution to our better understanding of Philippine rural society

Mobile travel services: A three-country study into the impact of local circumstances

In this paper we explore the difference in acceptance patterns of mobile services that are related to travelling in three countries: Finland, The Netherlands and New Zealand. The objective of this paper is to understand differences in the use of Mobile Travel Services in three countries that differ with regard to national travel patterns. This paper also contributes to the discussion of the relevance of the Technology Acceptance Model for mobile applications by focusing on the importance of context characteristics, such as the degree of mobility of the user, the social situation people are in, and their need for social interaction. Based on surveys in the three countries as executed in 2009, we use structural equation modelling to find differences in patterns. The paper concludes that context factors have an impact on the relation between the core concepts as used in TAM and DOI approach, and that t here is a clear need for closer research in the moderating effect of physical (e.g. mobile and fixed context) and social context, as well as the need for social interaction. Moreover it is clear that country specific characteristics play a role in the acceptance of mobile travel services. As we pointed out in many of our research projects before the acceptance and use of mobile services requires deep understanding from individual, context and technology related characteristics and their mutual interactions

Rural Development Reconsidered: Some Emerging Niches for Population Studies

This paper attempts to identify a number of emerging population-relevant rural scenarios that require a more creative degree of understanding complex interactive determinants and consequences both at the micro and macro levels. It offers several settings which are illustrative rather than exhaustive and definitive and are hoped to become part of future research agenda.urbanization, environmental issues, poverty, rural sector