Event‐switched control design with guaranteed performances

In this paper, a new event‐switched control method is presented for controlling discrete‐time linear systems subject to bounded disturbances. The main advantage of the proposed method is that the nominal performance of the controlled system with periodic control updates is kept in a framework that do not require to periodically update the control law. The feedback control loop can be opened as long a state‐dependent event condition is satisfied. This condition is obtained using set theory approaches. In particular, the concept of robustly positively invariant sets is used to calculate the nominal performance and the event condition. The simulation presented in this paper confirms the efficiency of the present approach. A reduction of the numerical complexity of the approach is also proposed. Copyright © 2016 John Wiley & Sons, Ltd.     

Monoterpene effect on feeding choice by deer

A previous study showed that Sitka black-tailed deer (Odocoileus hemionus sitkensis) consumption was negatively correlated with monoterpene content in western redcedar (Thuja plicata). To test whether these monoterpenes were deterrent to Sitka black-tailed deer, we performed feeding choice experiments with four hydrocarbon (sabinene, myrcene, -pinene, and d + l-limonene) and one oxygenated (,-thujone) monoterpene solution at their highest natural concentration in western redcedar foliage. To test whether deer response was species specific, we ran similar experiments on European roe deer (Capreolus capreolus) and rusa deer (Cervus timorensis russa). In all experiments, monoterpenes were repellent. Solutions with ,-thujone, the major monoterpene in redcedar leaves, were the most repellent of the solutions tested. We then analyzed how black-tailed and roe deer responded to (1) an increase in concentration of the monoterpenes with the weakest repellent effects (hydrocarbon monoterpenes) and (2) a decrease in concentration of the monoterpene with strongest effect (,-thujone). Repellency tended to increase with concentration for hydrocarbon monoterpenes, but remained strong for ,-thujone. As wild deer regularly feed on plants containing monoterpenes, this raises the question as to how the animals deal with these molecules.     

Chiral Phosphoric Acid‐Catalyzed Enantioselective Aza‐Friedel–Crafts Alkylation of Indoles with γ‐Hydroxy‐γ‐lactams

An enantioselective aza‐Friedel–Crafts reaction of indoles with γ‐hydroxy‐γ‐lactams using a chiral phosphoric acid catalyst is reported. The approach described herein provides an efficient access to 5‐indolylpyrrolidinones in good to quantitative yields and excellent enantioselectivities (up to >99% ee). The results suggest that the reaction may proceed via N‐acyliminium intermediates associated with the chiral phosphoric acid anion.     

In situ Dynamic Rheological Study of Polyacrylamide during Gelation Coupled with Mathematical Models of Viscosity Advancement

Acrylamide dynamic viscosity has been measured in aqueous solutions. Separate rheological measurements were performed on neat resins devoid of the curing agent over a range of shear rates to yield the initial resin viscosity. The gels were also characterized by sub‐ambient DSC to determine the phase structure as a function of formulation. The dynamic viscosity shows a marked sigmoidal behavior with a plateau viscosity. Mathematical interpretations of the gel time both by sigmoidal and power law models were comparable. The power law model allowed a direct determination of the gel time while the sigmoidal model yielded parameters associated with the initial viscosity, one associated with the plateau viscosity of the gel, and two time constants controlling the sharpness of the transition.

     

Ecosystem mapping at the African continent scale using a hybrid clustering approach based on 1-km resolution multi-annual data from SPOT/VEGETATION

The goal of this study is to propose a new classification of African ecosystems based on an 8-year analysis of Normalized Difference Vegetation Index (NDVI) data sets from SPOT/VEGETATION. We develop two methods of classification. The first method is obtained from a k-nearest neighbour (k-NN) classifier, which represents a simple machine learning algorithm in pattern recognition. The second method is hybrid in that it combines k-NN clustering, hierarchical principles and the Fast Fourier Transform (FFT). The nomenclature of the two classifications relies on three levels of vegetation structural categories based on the Land Cover Classification System (LCCS). The two main outcomes are: (i) The delineation of the spatial distribution of ecosystems into five bioclimatic ecoregions at the African continental scale; (ii) Two ecosystem maps were made sequentially: an initial map with 92 ecosystems from the k-NN, plus a deduced hybrid classification with 73 classes, which better reflects the bio-geographical patterns. The inclusion of bioclimatic information and successive k-NN clustering elements helps to enhance the discrimination of ecosystems. Adopting this hybrid approach makes the ecosystem identification and labelling more flexible and more accurate in comparison to straightforward methods of classification. The validation of the hybrid classification, conducted by crossing-comparisons with validated continental maps, displayed a mapping accuracy of 54% to 61%.     

Action compatibility effects are hedonically marked and have incidental consequences on affective judgment.

Recent results from Cannon, Hayes, and Tipper (2010) have established that the Action Compatibility Effect (ACE) is hedonically marked and elicits a genuine positive reaction. In this work, we aim to show that the hedonic marking of the ACE has incidental consequences on affective judgment. For this, we used the affective priming paradigm principle (for a review, see Musch & Klauer, 2003): participants have to respond, as quickly as they can, regarding the pleasantness or unpleasantness character of a target word. In the priming phase, we do not present an affective stimulus; however, we present two different graspable objects, one after the other. The handles of the graspable objects are shown either both on the same side (i.e., perceptual action compatibility) or not (i.e., perceptual action incompatibility). In addition, the orientation of the handles of the objects are either compatible (i.e., action compatibility) or not (i.e., action compatibility) with the response hand used for the word evaluation. Consistent with our hypothesis, participants responded faster to positive words after perceptual action compatibility and action compatibility (thus demonstrating the ACE) than after incompatibility conditions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Long-term storage conditions for carriers with denitrifying biomass of the fluidized, methanol-fed denitrification reactor of the Montreal Biodome, and the impact on denitrifying activity and bacterial population

The Montreal Biodome has a denitrification system to stabilize the nitrate concentration in its 3 million liter seawater aquarium. However, this microbial process has failed periodically due to various technical problems. The system can take several weeks to recover its full denitrification capacity. In order to provide the denitrification system with a backup of active biomass, different freezing conditions for the denitrifying biomass were tested. The biomass was conserved for 1 week-17 months at -20 degrees C with and without glycerol or at -80 degrees C with and without glycerol, and the denitrifying activity was tested in batch culture for 140 h periods at various intervals. Our results showed that glycerol was required for fast recovery of the microbial community's denitrifying activity. The -20 degrees C and -80 degrees C conservation temperatures with glycerol gave similar results although there was a short period of nitrite accumulation in the -20 degrees C sample. There were no substantial changes in the microbial community of any of the frozen samples after 17 months of conservation as monitored by denaturing gradient gel electrophoresis. This is the first report on the long-term conservation of a complex denitrifying population by freezing.     

Spatial Logic and the Distribution of Open and Green Public Spaces in Hanoi: Planning in a Dense and Rapidly Changing City

Vietnam recently started to recognise the multiple benefits brought by open and green spaces to urban population and environment. In this paper, we analyse the provision of open and green spaces (parks, public gardens and lakeshores) in Hanoi. Using a model proposed by Talen (2010), we examine the spatial evolution of these spaces between 2000 and 2010, their level of proximity to residential units, and the extent to which their distribution matches social needs (defined in terms of population density). We find that while the absolute number and surface area of parks and public gardens has increased significantly in Hanoi, these new public spaces are mainly built on the city’s newly urbanised periphery. As a result, in 2010, only 15% of Hanoi’s residential blocks had access to a park or public garden within a reasonable walking (1000m) or biking distance (2500m). Moreover, the city’s densest residential areas have only access to relatively small gardens and parks, resulting in overcrowding. Lakeshores, however, represent an opportunity to enhance access to open and green spaces in Hanoi due to their spatial distribution. We conclude by advocating for the integration of spatial measures of proximity and needs into Hanoi’s public space planning policy framework.     

Extended equivalent linear model (X-ELM) to assess liquefaction triggering: Application to the City of Urayasu during the 2011 Tohoku earthquake

This paper proposes a hybrid iterative approach to evaluating the liquefaction potential and settlements when liquefaction is not triggered for a saturated sand deposit subjected to seismic motion. The proposed method is a combination of an equivalent linear dynamic analysis and an empirical pore pressure build-up model. The two concepts are combined to account for the increase of pore-water pressure in the dynamic response. This extended equivalent linear model, or X-ELM, introduces a parameter $\chi$ identified by means of an extensive set of computations and observations. The approach has been validated in the case of Urayasu City during the 2011 Great East Japan Earthquake. The X-ELM enables the assessment of the triggering of the soil liquefaction of 12 representative soil profiles, namely, four profiles representing non-liquefied grounds in the old town of Urayasu and eight profiles representing the liquefaction-prone grounds in the reclaimed area of the city. The X-ELM computed areas of triggered liquefaction or non-liquefaction are found to be in good agreement with qualitative observations and in-situ measured responses.