Predicting and Explaining Human Semantic Search in a Cognitive Model

Recent work has attempted to characterize the structure of semantic memory and the search algorithms which, together, best approximate human patterns of search revealed in a semantic fluency task. There are a number of models that seek to capture semantic search processes over networks, but they vary in the cognitive plausibility of their implementation. Existing work has also neglected to consider the constraints that the incremental process of language acquisition must place on the structure of semantic memory. Here we present a model that incrementally updates a semantic network, with limited computational steps, and replicates many patterns found in human semantic fluency using a simple random walk. We also perform thorough analyses showing that a combination of both structural and semantic features are correlated with human performance patterns.Comment: To appear in proceedings for CMCL 201

Simple Search Algorithms on Semantic Networks Learned from Language Use

Recent empirical and modeling research has focused on the semantic fluency task because it is informative about semantic memory. An interesting interplay arises between the richness of representations in semantic memory and the complexity of algorithms required to process it. It has remained an open question whether representations of words and their relations learned from language use can enable a simple search algorithm to mimic the observed behavior in the fluency task. Here we show that it is plausible to learn rich representations from naturalistic data for which a very simple search algorithm (a random walk) can replicate the human patterns. We suggest that explicitly structuring knowledge about words into a semantic network plays a crucial role in modeling human behavior in memory search and retrieval; moreover, this is the case across a range of semantic information sources

A model for uphill droplet motion

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.This paper focuses on the behaviour of a liquid droplet over the surface of a treated solid substrate. It deals with the use of surface tension forces induced by setting up a gradient of wettability to allow the evacuation of the dispersed phase. The main aim is to present a new model capable of predicting the motion of a droplet of known volume over a surface with a wettability gradient that explicitly takes contact angle hysteresis into account. Several authors have established a phenomenological footprint radius, from which the droplet starts moving. Our model, provides a relationship to find this critical droplet size. The results show that the contact angle hysteresis parameter appears to be a key issue in droplet dynamics and in the accurate prediction of droplet motion

Experimental Study of Slug Flow for Condensation in a Square Cross-Section Micro-Channel at Low Mass Velocities

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In this paper, condensation flows in a cross-flow air-cooled micro-condenser were investigated for mass velocities (representing the mass flow rates over the micro-condenser cross-section area) lower than 12 kg.m (−2).s(−1), with n-pentane used as the working fluid. This micro-condenser consisted of a transparent square cross-section micro-channel placed horizontally, having inner and outer edges of 553 and 675 μm, respectively, and a real length exposed to the coolant of 196 mm. One of the specificities of the experimental bench was the choice of the air as a coolant so that the external heat transfer is limiting. Three main flow zones were identified: annular zone, intermittent (i.e. elongated bubbles or slug) zone and spherical bubbles zone. A specific experimental procedure based on bubbles tracking was developed in order to determine the hydraulic and thermal parameters in the intermittent zone. The mean displacement and condensation velocities of the elongated bubbles were determined according to their mean length for different mass velocities of the n-pentane. Besides, the mean latent heat flux density released by the condensation of the elongated bubbles was determined according to their mean surface for different mass velocities of the n-pentane, and compared to the imposed heat flux density

On the effect of the dynamic contact angle of a vapor embryo interface trapped in a nucleation site

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The effect of boiling and cavitation phenomena on nucleation was first experimentally studied. Results highlight the fact that the "classical" theory of nucleation cannot describe such a configuration. New theoretical approaches were proposed in order to describe the dynamic effects which occur when the liquid pressure oscillates over time and when a heat flux imposed to the system. It then appears that the dynamic and the hysteresis of the contact angle may play a significant role in nucleation by simultaneous boiling and cavitation effects

Zombies in Western Culture

"Why has the zombie become such a pervasive figure in twenty-first-century popular culture? John Vervaeke, Christopher Mastropietro and Filip Miscevic seek to answer this question by arguing that particular aspects of the zombie, common to a variety of media forms, reflect a crisis in modern Western culture. The authors examine the essential features of the zombie, including mindlessness, ugliness and homelessness, and argue that these reflect the outlook of the contemporary West and its attendant zeitgeists of anxiety, alienation, disconnection and disenfranchisement. They trace the relationship between zombies and the theme of secular apocalypse, demonstrating that the zombie draws its power from being a perversion of the Christian mythos of death and resurrection. Symbolic of a lost Christian worldview, the zombie represents a world that can no longer explain itself, nor provide us with instructions for how to live within it. The concept of 'domicide' or the destruction of home is developed to describe the modern crisis of meaning that the zombie both represents and reflects. This is illustrated using case studies including the relocation of the Anishinaabe of the Grassy Narrows First Nation, and the upheaval of population displacement in the Hellenistic period. Finally, the authors invoke and reformulate symbols of the four horseman of the apocalypse as rhetorical analogues to frame those aspects of contemporary collapse that elucidate the horror of the zombie. Zombies in Western Culture: A Twenty-First Century Crisis is required reading for anyone interested in the phenomenon of zombies in contemporary culture. It will also be of interest to an interdisciplinary audience including students and scholars of culture studies, semiotics, philosophy, religious studies, eschatology, anthropology, Jungian studies, and sociology.

Control of pool boiling incipience in confined space: dynamic morphing of the wall effect

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.A new active heat transfer enhancement and control technique is proposed in this work. One of the major aims of the technique is to decrease pool boiling incipience temperature by dynamic morphing imposed to confinement wall. Dynamic deformation generates variation of pressure which increases the fluid metastability level. An experimental device was built to evaluate boiling incipience temperature. Experimental results were compared with hydrodynamic and nucleation models.CNRS Energie CITAMPE PR09-3.1.3-2 and FNRAE SYRTIP