Conscious machines: memory, melody and muscular imagination

A great deal of effort has been, and continues to be, devoted to developing consciousness artificially (A small selection of the many authors writing in this area includes: Cotterill (J Conscious Stud 2:290–311, 1995, 1998), Haikonen (2003), Aleksander and Dunmall (J Conscious Stud 10:7–18, 2003), Sloman (2004, 2005), Aleksander (2005), Holland and Knight (2006), and Chella and Manzotti (2007)), and yet a similar amount of effort has gone in to demonstrating the infeasibility of the whole enterprise (Most notably: Dreyfus (1972/1979, 1992, 1998), Searle (1980), Harnad (J Conscious Stud 10:67–75, 2003), and Sternberg (2007), but there are a great many others). My concern in this paper is to steer some navigable channel between the two positions, laying out the necessary pre-conditions for consciousness in an artificial system, and concentrating on what needs to hold for the system to perform as a human being or other phenomenally conscious agent in an intersubjectively-demanding social and moral environment. By adopting a thick notion of embodiment—one that is bound up with the concepts of the lived body and autopoiesis (Maturana and Varela 1980; Varela et al. 2003; and Ziemke 2003, 2007a, J Conscious Stud 14(7):167–179, 2007b)—I will argue that machine phenomenology is only possible within an embodied distributed system that possesses a richly affective musculature and a nervous system such that it can, through action and repetition, develop its tactile-kinaesthetic memory, individual kinaesthetic melodies pertaining to habitual practices, and an anticipatory enactive kinaesthetic imagination. Without these capacities the system would remain unconscious, unaware of itself embodied within a world. Finally, and following on from Damasio’s (1991, 1994, 1999, 2003) claims for the necessity of pre-reflective conscious, emotional, bodily responses for the development of an organism’s core and extended consciousness, I will argue that without these capacities any agent would be incapable of developing the sorts of somatic markers or saliency tags that enable affective reactions, and which are indispensable for effective decision-making and subsequent survival. My position, as presented here, remains agnostic about whether or not the creation of artificial consciousness is an attainable goal

Femtosecond study of the interplay between excitons, trions, and carriers in (Cd,Mn)Te quantum wells

We present an absorption study of the neutral and positively charged exciton (trion) under the influence of a femtosecond, circularly polarized, resonant pump pulse. Three populations are involved: free holes, excitons, and trions, all exhibiting transient spin polarization. In particular, a polarization of the hole gas is created by the formation of trions. The evolution of these populations is studied, including the spin flip and trion formation processes. The contributions of several mechanisms to intensity changes are evaluated, including phase space filling and spin-dependent screening. We propose a new explanation of the oscillator strength stealing phenomena observed in p-doped quantum wells, based on the screening of neutral excitons by charge carriers. We have also found that binding heavy holes into charged excitons excludes them from the interaction with the rest of the system, so that oscillator strength stealing is partially blockedComment: 4 pages, 4 figure

Traduction comparée du français et de l'arabe

Cet article se propose de trouver des exemples en arabe et en français qui peuvent illustrer les procédés comparatifs de traduction élaborés par J. P. Vinay et J. Darbelnet dans leur ouvrage intitulé Stylistique comparée du français et de l'anglais, et complétés  plus tard par H. Chuquet et M. Paillard, dans leur ouvrage intitulé Approche linguistique des problèmes de traduction : anglais–français.  En fait, nous avons remarqué que ces procédés ne sont souvent abordés qu'occasionnellement dans les manuels de traduction français-arabe. Aussi, nous avons pensé qu'il serait nécessaire d'apporter notre pierre à cet édifice tout en jetant un regard critique. Nous montrerons à la fin de notre article les limites du modèle comparatif qui ne permet qu'une analyse descriptive et hors contexte, même s'il constitue un jalon important sur le chemin de la traduction et de la compréhension de deux systèmes langagiers différents.

The ‘long tail’ of anthropogenic CO₂ decline in the atmosphere and its consequences for post-closure performance assessments for disposal of radioactive wastes

AbstractThe extended timescales involved in the decay of radioactive wastes to safe levels mean that geological disposal facilities must continue to function effectively long into the future. It is therefore essential to consider long-term climate evolution in post-closure performance assessments in order to evaluate a geological disposal system's response and robustness to a variety of potential environmental changes, driven by both natural and anthropogenic forcings. In this paper, we illustrate the multiple decay components that characterize the primary driver of climate change – atmospheric CO2 – in response to fossil fuel carbon emissions. We perform a multi-exponential analysis on a series of atmospheric CO2 decay curves predicted by an Earth system model and create an empirical response function that encapsulates the long-term (&gt;1 kyr) removal of excess CO2 from the atmosphere. We present this response function as a simple tool for rapidly projecting the future atmospheric CO2 concentration resulting from any plausible cumulative release of CO2. We discuss the implications of the long 'tail' to this atmospheric CO2 decay curve, both in terms of future climate evolution as well as potential impacts on radioactive waste repositories.</jats:p

Experimental and modeling study of the autoignition of 1-hexene/iso-octane mixtures at low temperatures

Autoignition delay times have been measured in a rapid compression machine at Lille at temperatures after compression from 630 to 840 K, pressures from 8 to 14 bar, \Phi = 1 and for a iso octane/1 hexene mixture containing 82% iso-octane and 18% 1 hexene. Results have shown that this mixture is strongly more reactive than pure iso-octane, but less reactive than pure 1 hexene. It exhibits a classical low temperature behaviour, with the appearance of cool flame and a negative temperature coefficient region. The composition of the reactive mixture obtained after the cool flame has also been determined. A detailed kinetic model has been obtained by using the system EXGAS, developed in Nancy for the automatic generation of kinetic mechanisms, and an acceptable agreement with the experimental results has been obtained both for autoignition delay times and for the distribution of products. A flow rate analysis reveals that the crossed reactions between species coming from both reactants (like H-abstractions or combinations) are negligible in the main flow consumption of the studied hydrocarbons. The ways of formation of the main primary products observed and the most sensitive rate constants have been identified

Statistical optimization for passive scalar transport: maximum entropy production vs maximum Kolmogorov-Sinay entropy

We derive rigorous results on the link between the principle of maximum entropy production and the principle of maximum Kolmogorov-Sinai entropy using a Markov model of the passive scalar diffusion called the Zero Range Process. We show analytically that both the entropy production and the Kolmogorov-Sinai entropy seen as functions of f admit a unique maximum denoted fmaxEP and fmaxKS. The behavior of these two maxima is explored as a function of the system disequilibrium and the system resolution N. The main result of this article is that fmaxEP and fmaxKS have the same Taylor expansion at _rst order in the deviation of equilibrium. We find that fmaxEP hardly depends on N whereas fmaxKS depends strongly on N. In particular, for a fixed difference of potential between the reservoirs, fmaxEP (N) tends towards a non-zero value, while fmaxKS (N) tends to 0 when N goes to infinity. For values of N typical of that adopted by Paltridge and climatologists we show that fmaxEP and fmaxKS coincide even far from equilibrium. Finally, we show that one can find an optimal resolution N_ such that fmaxEP and fmaxKS coincide, at least up to a second order parameter proportional to the non-equilibrium uxes imposed to the boundaries.Comment: Nonlinear Processes in Geophysics (2015