Reduced complexity set-point following in self-tuning control

An external input signal is incorporated into a self-tuning controller which, although it is based on a CARMA system model, employs a state-space framework for control law calculations. Steady-state set point following can then be accomplished even when only a recursive least squares parameter estimation scheme is used, despite the fact that the disturbance affecting the system may well be coloured.

Long-term acclimation of leaf production, development, longevity and quality following 3 yr exposure to free-air CO2 enrichment during canopy closure in Populus

The effects of elevated CO2 on leaf development in three genotypes of Populus were investigated during canopy closure, following exposure to elevated CO2 over 3 yr using free-air enrichment.• Leaf quality was altered such that nitrogen concentration per unit d. wt (Nmass) declined on average by 22 and 13% for sun and shade leaves, respectively, in elevated CO2. There was little evidence that this was the result of ‘dilution’ following accumulation of nonstructural carbohydrates. Most likely, this was the result of increased leaf thickness. Specific leaf area declined in elevated CO2 on average by 29 and 5% for sun and shade leaves, respectively.• Autumnal senescence was delayed in elevated CO2 with a 10% increase in the number of days at which 50% leaf loss occurred in elevated as compared with ambient CO2.• These data suggest that changes in leaf quality may be predicted following long-term acclimation of fast-growing forest trees to elevated CO2, and that canopy longevity may increase, with important implications for forest productivity.

The role of corticospinal tract damage in chronic motor recovery and neurorehabilitation: a pilot study

Background. With diffusion-tensor imaging (DTi) it is possible to estimate the structural characteristics of fiber bundles in vivo. This study used DTi to infer damage to the corticospinal tract (CST) and relates this parameter to (a) the level of residual motor ability at least 1 year poststroke and (b) the outcome of intensive motor rehabilitation with constraint-induced movement therapy (CIMT). Objective. To explore the role of CST damage in recovery and CIMT efficacy. Methods. Ten patients with low-functioning hemiparesis were scanned and tested at baseline, before and after CIMT. Lesion overlap with the CST was indexed as reduced anisotropy compared with a CST variability map derived from 26 controls. Residual motor ability was measured through the Wolf Motor Function Test (WMFT) and the Motor Activity Log (MAL) acquired at baseline. CIMT benefit was assessed through the pre—post treatment comparison of WMFT and MAL performance. Results. Lesion overlap with the CST correlated with residual motor ability at baseline, with greater deficits observed in patients with more extended CST damage. Infarct volume showed no systematic association with residual motor ability. CIMT led to significant improvements in motor function but outcome was not associated with the extent of CST damage or infarct volume. Conclusion. The study gives in vivo support for the proposition that structural CST damage, not infarct volume, is a major predictor for residual functional ability in the chronic state. The results provide initial evidence for positive effects of CIMT in patients with varying, including more severe, CST damage.

Where the interaction is: collisions of the situated and mediated in living room interactions

This article presents three ethnographic tales of interactions with living room media to help recreate the experience of significant moments in time, of affective encounters at the interface in which there is a collision or confusion of situated and virtual worlds. It draws on a year-long video ethnography of the practice and performance of everyday interactions with living room media. By studying situated activity and the lived practice of (new) media, rather than taking an exclusive focus on the virtual as a detached space, this ethnographic work demonstrates how the situated and mediated clash, or are crafted into complex emotional encounters during everyday living room life.

Bottom-up planning and the future of planning education in India

The article discusses normative guidelines for reorienting planning education in India within the context of the immensely influential Constitutional Amendment Act of 1993. First, it briefly sketches the status of planning education at present in India, in relation to the role of planners in planning practice. It then descibes the changes that have taken place in general, following the Constitutional Amendment Act, dwelling more on the specific changes within the State of Kerala. The implications of these for planning education in general are then discussed normatively, highlighting three areas that need immediate attention from the planning academic community.

Accessing extremes of mid-latitudinal wave activity: methodology and application

A statistical methodology is proposed and tested for the analysis of extreme values of atmospheric wave activity at mid-latitudes. The adopted methods are the classical block-maximum and peak over threshold, respectively based on the generalized extreme value (GEV) distribution and the generalized Pareto distribution (GPD). Time-series of the ‘Wave Activity Index’ (WAI) and the ‘Baroclinic Activity Index’ (BAI) are computed from simulations of the General Circulation Model ECHAM4.6, which is run under perpetual January conditions. Both the GEV and the GPD analyses indicate that the extremes ofWAI and BAI areWeibull distributed, this corresponds to distributions with an upper bound. However, a remarkably large variability is found in the tails of such distributions; distinct simulations carried out under the same experimental setup provide sensibly different estimates of the 200-yr WAI return level. The consequences of this phenomenon in applications of the methodology to climate change studies are discussed. The atmospheric configurations characteristic of the maxima and minima of WAI and BAI are also examined.

The regional and global competitiveness of multinational firms

International competitiveness ultimately depends upon the linkages between a firm’s unique, idiosyncratic capabilities (firm-specific advantages, FSAs) and its home country assets (country-specific advantages, CSAs). In this paper, we present a modified FSA/CSA matrix building upon the FSA/CSA matrix (Rugman 1981). We relate this to the diamond framework for national competitiveness (Porter 1990), and the double diamond model (Rugman and D’Cruz 1993). We provide empirical evidence to demonstrate the merits and usefulness of the modified FSA/CSA matrix using the Fortune Global 500 firms. We examine the FSAs based on the geographic scope of sales and CSAs that can lead to national, home region, and global competitiveness. Our empirical analysis suggests that the world’s largest 500 firms have increased their firm-level international competitiveness. However, much of this is still being achieved within their home region. In other words, international competitiveness is a regional not a global phenomenon. Our findings have significant implications for research and practice. Future research in international marketing should take into account the multi-faceted nature of FSAs and CSAs across different levels. For MNE managers, our study provides useful insights for strategic marketing planning and implementation.

Bayesian estimation of the spatial Durbin error model with an application to voter turnout in the 2004 presidential election

The potential for spatial dependence in models of voter turnout, although plausible from a theoretical perspective, has not been adequately addressed in the literature. Using recent advances in Bayesian computation, we formulate and estimate the previously unutilized spatial Durbin error model and apply this model to the question of whether spillovers and unobserved spatial dependence in voter turnout matters from an empirical perspective. Formal Bayesian model comparison techniques are employed to compare the normal linear model, the spatially lagged X model (SLX), the spatial Durbin model, and the spatial Durbin error model. The results overwhelmingly support the spatial Durbin error model as the appropriate empirical model.

Assessing the impact of occupant behaviour on the electricity consumption for lighting and small power in office buildings

Lighting and small power will typically account for more than half of the total electricity consumption in an office building. Significant variations in electricity used by different tenants suggest that occupants can have a significant impact on the electricity demand for these end-uses. Yet current modelling techniques fail to represent the interaction between occupant and the building environment in a realistic manner. Understanding the impact of such behaviours is crucial to improve the methodology behind current energy modelling techniques, aiming to minimise the significant gap between predicted and in-use performance of buildings. A better understanding of the impact of occupant behaviour on electricity consumption can also inform appropriate energy saving strategies focused on behavioural change. This paper reports on a study aiming to assess the intent of occupants to switch off lighting and appliances when not in use in office buildings. Based on the Theory of Planned Behaviour, the assessment takes the form of a questionnaire and investigates three predictors to behaviour individually: 1) behavioural attitude; 2) subjective norms; 3) perceived behavioural control. The paper details the development of the assessment procedure and discusses preliminary findings from the study. The questionnaire results are compared against electricity consumption data for individual zones within a multi-tenanted office building. Initial results demonstrate a statistically significant correlation between perceived behavioural control and energy consumption for lighting and small power

Drivers of increased soil respiration in a poplar coppice exposed to elevated CO2

Background and Aims. The response of soil respiration (SR) to elevated CO2 is driven by a number of processes and feedbacks. This work aims to i) detect the effect of elevated CO2 on soil respiration during the second rotation of a short rotation forest, at two levels of N availability; and ii) identify the main drivers behind any changes in soil respiration. Methods. A poplar plantation (POP-EUROFACE) was grown for two rotations of three years under elevated CO2 maintained by a FACE (Free Air CO2 Enrichment) technique. Root biomass, litter production and soil respiration were followed for two consecutive years after coppice. Results. In the plantation, the stimulation of fine root and litter production under elevated CO2 observed at the beginning of the rotation declined over time. Soil respiration (SR) was continuously stimulated by elevated CO2, with a much larger enhancement during the growing (up to 111 %) than in the dormant season (40 %). The SR increase at first appeared to be due to the increase in fine root biomass, but at the end of the 2nd rotation was supported by litter decomposition and the availability of labile C. Soil respiration increase under elevated CO2 was not affected by N availability. Conclusions. The stimulation of SR by elevated CO2 was sustained by the decomposition of above and belowground litter and by the greater availability of easily decomposable substrates into the soil. C losses through SR were greater in the last year of the plantation due to a lack of effect of elevated CO2 on C allocation to roots, reducing the potential for C accumulation.