Stigmergic epistemology, stigmergic cognition

To know is to cognize, to cognize is to be a culturally bounded, rationality-bounded and environmentally located agent. Knowledge and cognition are thus dual aspects of human sociality. If social epistemology has the formation, acquisition, mediation, transmission and dissemination of knowledge in complex communities of knowers as its subject matter, then its third party character is essentially stigmergic. In its most generic formulation, stigmergy is the phenomenon of indirect communication mediated by modifications of the environment. Extending this notion one might conceive of social stigmergy as the extra-cranial analog of an artificial neural network providing epistemic structure. This paper recommends a stigmergic framework for social epistemology to account for the supposed tension between individual action, wants and beliefs and the social corpora. We also propose that the so-called ‘‘extended mind’’ thesis offers the requisite stigmergic cognitive analog to stigmergic knowledge. Stigmergy as a theory of interaction within complex systems theory is illustrated through an example that runs on a particle swarm optimization algorithm.Social epistemology; Extended mind; Social cognition; Particle swarm optimization

Impact de la variabilité non-mesurée des précipitations sur les débits en hydrologie urbaine : un cas d'étude dans le cadre multifractal

National audienceCet article utilise les propriétés multifractales d'un évènement pluvieux dans la région de Londres le 9 février 2009, pour mieux comprendre et quantifier 'incertitude associée à la variabilité spatio-temporelle des précipitations non mesurées par les radars météorologiques en bande C, dont la résolution estimée est de 1 km*1 km*5min, et comment elle se transfère aux prévisions des débits en réseaux d'assainissement. Le cas d'étude hydrologique est celui du bassin versant urbain de 900 hectares de Cranbrook (Londres). Les propriétés multifractales sont en accord avec le modèle spatio-temporel le plus simple, reposant sur un exposant d'anisotropie entre l'espace et le temps. Ceci permet de désagréger le champ de précipitation à l'aide de cascades multifractales spatio-temporelles. Un ensemble de champs de précipitations désagrégés réalistes est alors généré à l'aide des multifractals universels, puis l'ensemble des hydrogrammes correspondants est obtenu par un modèle urbain pluie-débit semi-distribué. Il apparait que les queues de probabilité issues de l'analyse de 100 échantillons de précipitation présentent un comportement en loi de puissance, qui est retrouvé sur les débits de pointe mais avec des exposants différent

Consciousness and its Place in Nature: Does Physicalism Entail Panpsychism?

This collection of papers, Consciousness and its Place in Nature: Does Physicalism Entail Panpsychism?, edited by Anthony Freeman presents seventeen responses to Galen Strawson’s keynote paper which claims that the only plausible way to be a real physicalist is to accept that the intrinsic properties of the physical are experiential in character, i.e., the doctrine of panpsychism. The book concludes with Strawson’s reply to these responses. This “real physicalism” is, according to Strawson, the only way of dealing with what Chalmers calls the “hard problem of consciousness.” This problem lies in the fact that the experiential nature of our conscious experience is a puzzling phenomenon for the materialist. It is of an apparently fundamentally different nature from the rest of the physical world, hence the problem of integrating it into a satisfactory naturalistic world-pictur

A rainfall model for drought risk analysis in south-east UK

Drought risk assessment ideally requires long-term rainfall records especially where inter-annual droughts are of potential concern, and spatially consistent estimates of rainfall to support regional and inter-regional scale assessments. This paper addresses these challenges by developing a spatially consistent stochastic model of monthly rainfall for south-east UK. Conditioned on 50 gauged sites, the model infills the historic record from 1855-2011 in both space and time, and extends the record by synthesising droughts which are consistent with the observed rainfall statistics. The long record length allows more insight into the variability of rainfall and potentially a stronger basis for risk assessment than is generally possible. It is shown that, although localised biases exist in both space and time, the model results are generally consistent with the observed record including for a range of inter-annual droughts and spatial statistics. Simulations show that some of the most severe inter-annual droughts on the record may recur, despite a trend towards generally wetter winters

A Cox process with State-Dependent exponential pulses to model rainfall

A point process model based on a class of Cox processes is developed to analyse precipitation data at a point location. The model is constructed using state-dependent exponential pulses that are governed by an unobserved underlying Markov chain. The mathematical formulation of the model where both the arrival rate of the rain cells and the initial pulse depth are determined by the Markov chain is presented. Second-order properties of the rainfall depth process are derived and utilised in model assessment. A method of moment estimation is employed in model fitting. The proposed model is used to analyse 69 years of sub-hourly rainfall data from Germany and 15 years of English rainfall data. The results of the analysis using variants of the proposed model with fixed pulse lifetime and variable pulse duration are presented. The performance of the proposed model, in reproducing second-moment characteristics of the rainfall, is compared with that of two stochastic models where one has exponential pulses and the other has rectangular pulses. The proposed model is found to capture most of the empirical rainfall properties well and outperform the two alternative models considered in our analysis

Spatial and temporal dependence framework in multi-site precipitation modelling

Multi-site stochastic models consist of a rich class of models that can be utilised to analyse environmental data and provide a range of possible inputs to hydrological models to quantify uncertainty and assess risk in environmental systems. We develop a class of multi-site hidden Markov models that incorporate a copula to capture the characteristics of the daily precipitation process across a network of stations. The construction of the likelihood function of the proposed multi-site precipitation models is described. A copula with appropriate dependence structure is selected from the family of Archimedean copulas. The maximum likelihood method is used to estimate the parameters of the models. The proposed class of models is used to analyse twelve years of daily rainfall data from four weather stations in London, England. The copula-embedded multi-site models captured the properties of the daily rainfall well and reproduced the correlation structure of the daily precipitation better than the other hidden Markov models

Stochastic modelling of British rainfall using Poisson processes.

Imperial Users onl

Reality in-itself and the Ground of Causality

AbstractThis article presents a metaphysical approach to the interpretation of the role of things-in-themselves in Kant’s theoretical philosophy. This focuses upon identifying their transcendental function as the grounding of appearances. It is interpreted as defining the relation of appearing as the grounding of empirical causality. This leads to a type of dual-aspect account that is given further support through a detailed examination of two sections of Kant’s firstCritique. This shows the need to embed this dual-aspect account within a two-perspective framework. The resulting picture is contrasted with the main rival theories and objections are addressed.</jats:p