A non-linear structure preserving matrix method for the low rank approximation of the Sylvester resultant matrix

A non-linear structure preserving matrix method for the computation of a structured low rank approximation S((f) over bar , (g) over bar) of the Sylvester resultant matrix S(f , g) of two inexact polynomials f = f(y) and g = g(y) is considered in this paper. It is shown that considerably improved results are obtained when f (y) and g(y) are processed prior to the computation of S((f) over bar , (g) over bar), and that these preprocessing operations introduce two parameters. These parameters can either be held constant during the computation of S((f) over bar , (g) over bar), which leads to a linear structure preserving matrix method, or they can be incremented during the computation of S((f) over bar, (g) over bar), which leads to a non-linear structure preserving matrix method. It is shown that the non-linear method yields a better structured low rank approximation of S((f) over bar , (g) over bar) and that the assignment of f (y) and g(y) is important because S((f) over bar , (g) over bar) may be a good structured low rank approximation of S(f, g), but S((f) over bar , (g) over bar) may be a poor structured low rank approximation of S (g f) because its numerical rank is not defined. Examples that illustrate the differences between the linear and non-linear structure preserving matrix methods, and the importance of the assignment off (y) and g(y), are shown. (C) 2010 Elsevier B.V. All rights reserved

Structured total least norm and approximate GCDs of inexact polynomials

The determination of an approximate greatest common divisor (GCD) of two inexact polynomials f=f(y) and g=g(y) arises in several applications, including signal processing and control. This approximate GCD can be obtained by computing a structured low rank approximation S*(f,g) of the Sylvester resultant matrix S(f,g). In this paper, the method of structured total least norm (STLN) is used to compute a low rank approximation of S(f,g), and it is shown that important issues that have a considerable effect on the approximate GCD have not been considered. For example, the established works only yield one matrix S*(f,g), and therefore one approximate GCD, but it is shown in this paper that a family of structured low rank approximations can be computed, each member of which yields a different approximate GCD. Examples that illustrate the importance of these and other issues are presented

Mixed adsorption and surface tension prediction of nonideal ternary surfactant systems

To deal with the mixed adsorption of nonideal ternary surfactant systems, the regular solution approximation for nonideal binary surfactant systems is extended and a pseudo-binary system treatment is also proposed. With both treatments, the compositions of the mixed monolayer and the solution concentrations required to produce given surface tensions can be predicted based only on the gamma-LogC curves of individual surfactants and the pair interaction parameters. Conversely, the surface tensions of solutions with different bulk compositions can be predicted by the surface tension equations for mixed surfactant systems. Two ternary systems: SDS/Hyamine 1622/AEO7, composed of homogeneous surfactants, and AES/DPCl/AEO9, composed of commercial surfactants, in the presence of excess NaCl, are examined for the applicability of the two treatments. The results show that, in general, the pseudo-binary system treatment gives better prediction than the extended regular solution approximation, and the applicability of the latter to typical anionic/cationic/nonionic nonideal ternary surfactant systems seems to depend on the combined interaction parameter, $${\mathop {(\beta }\nolimits_{an}^s } + {\mathop \beta \nolimits_{cn}^s })/2 - {\mathop \beta \nolimits_{ac}^s }/4$$ : the more it deviates from zero, the larger the prediction difference. If $${\mathop {(\beta }\nolimits_{an}^s } + {\mathop \beta \nolimits_{cn}^s })/2 - {\mathop \beta \nolimits_{ac}^s }/4$$ rarr0, good agreements between predicted and experimental results can be obtained and both treatments, though differently derived, are interrelated and tend to be equivalent

The felt-presence experience:from cognition to the clinic

The Felt Presence (FP) experience is the basic feeling that someone else is present in the immediate environment, without any other clear sensory evidence. Ranging from benevolent to distressing, personified to ambiguous, FP has been observed in neuropsychological case studies, within psychosis and paranoia, associated with sleep paralysis, anxiety, and recorded within endurance sports and spiritualist communities. In this review we summarise the philosophical and phenomenological, clinical and non-clinical correlates of FP, as well current measurement using psychometric, cognitive, and neurophysiological methods. We present current mechanistic explanations for FP, suggest a unifying cognitive framework for the phenomenon, and discuss outstanding questions for the field. FP offers a sublime window of opportunity to understand the cognitive neuroscience of own-body awareness and social agency detection; an intuitive, but poorly understood experience in health and disorder

The felt-presence experience: from cognition to the clinic

The felt presence experience is the basic feeling that someone else is present in the immediate environment, without clear sensory evidence. Ranging from benevolent to distressing, personified to ambiguous, felt presence has been observed in neurological case studies and within psychosis and paranoia, associated with sleep paralysis and anxiety, and recorded within endurance sports and spiritualist communities. In this Review, we summarise the philosophical, phenomenological, clinical, and non-clinical correlates of felt presence, as well as current approaches that use psychometric, cognitive, and neurophysiological methods. We present current mechanistic explanations for felt presence, suggest a unifying cognitive framework for the phenomenon, and discuss outstanding questions for the field. Felt presence offers a sublime opportunity to understand the cognitive neuroscience of own-body awareness and social agency detection, as an intuitive, but poorly understood, experience in health and disorder

Noncognitive skills in the classroom

This book provides an overview of recent research on the relationship between noncognitive attributes (motivation, self efficacy, resilience) and academic outcomes (such as grades or test scores). We focus primarily on how these sets of attributes are measured and how they relate to important academic outcomes. Noncognitive attributes are those academically and occupationally relevant skills and traits that are not “cognitive”—that is, not specifically intellectual or analytical in nature. We examine seven attributes in depth and critique the measurement approaches used by researchers and talk about how they can be improved.Publishe

Vegetation history and climatic fluctuations on a transect along the Dead Sea west shore and impact on past societies over the last 3500 years.

This study represents the vegetation history of the last 3500 years and conducts an analysis of the climatic fluctuations on a 75 km long transect on the western Dead Sea shore. Palynological and sedimentological data are available from six cores near Mount Sedom, Ein Boqueq, and Ein Gedi and from outcrops near Ze'elim and Ein Feshkha. The comparison of the pollen data with the lake levels shows synchronous trends. During the Middle Bronze Age, Iron Age and Hellenistic to Byzantine Period the high lake level of the Dead Sea signals an increase in precipitation. Contemporaneously, values of cultivated plants indicate an increase in agriculture. Lake level is low during the Late Bronze Age, within the Iron Age and at the end of the Byzantine period, indicating dry periods when all pds show a decrease of cultivated plants. Forest regeneration led by drought-resistant pines is observed in all pollen diagrams (pds) following the agricultural decline in the Byzantine period and, in the pds near Ein Boqeq, Ze'elim and Ein Feshkha, during the late Iron Age. The modern vegetation gradient is reflected in the palaeo-records: a stronger expansion of Mediterranean vegetation and cultivated plants in the northern sites is recognisable

Twenty challenges for innovation studies

With the field of innovation studies now half a century old, the occasion has been marked by several studies looking back to identify the main advances made over its lifetime. Starting from a list of 20 advances over the field’s history, this discussion paper sets out 20 challenges for coming decades. The intention is to prompt a debate within the innovation studies community on what are, or should be, the key challenges for us to take up, and more generally on what sort of field we aspire to be. It is argued that the empirical focus of our studies has failed to keep pace with the fast changing world and economy, especially the shift from manufacturing to services and the increasingly urgent need for sustainability. Moreover, the very way we conceptualise, define, operationalise and analyse ‘innovation’ seems somewhat rooted in the past, leaving us less able to grapple with other less visible or ‘dark’ forms of innovation