Synchronization of discrete-time complex dynamical networks with interval time-varying delays via non-fragile controller with randomly occurring perturbation

This paper addresses synchronization problem for discrete-time complex dynamical networks with interval time-varying delays. In order to achieve the synchronization, a feedback controller subjected to randomly occurring perturbations will be considered. The randomly occurring perturbations are assumed to belong to the Binomial sequence. By constructing a suitable Lyapunov–Krasovskii functional, and utilizing reciprocally convex approach and Finsler?s lemma, the synchronization criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. The networks are represented by the use of Kronecker product technique. The effectiveness of the proposed methods will be verified via numerical examples.     

Study for optical manipulation of a surfactant-covered droplet using lattice Boltzmann method

In this study, we simulated deformation and surfactant distribution on the interface of a surfactant-covered droplet using optical tweezers as an external source. Two optical forces attracted a single droplet from the center to both sides. This resulted in an elliptical shape deformation. The droplet deformation was characterized as the change of the magnitudes of surface tension and optical force. In this process, a non-linear relationship among deformation, surface tension, and optical forces was observed. The change in the local surfactant concentration resulting from the application of optical forces was also analyzed and compared with the concentration of surfactants subjected to an extensional flow. Under the optical force influence, the surfactant molecules were concentrated at the droplet equator, which is totally opposite to the surfactants behavior under extensional flow, where the molecules were concentrated at the poles. Lastly, the quasi-equilibrium surfactant distribution was obtained by combining the effects of the optical forces with the extensional flow. All simulations were executed by the lattice Boltzmann method which is a powerful tool for solving micro-scale problems.     

Changes in velocity profile according to blood viscosity in a microchannel

Red blood cells (RBCs) are important to dictate hemorheological properties of blood. The shear-thinning effect of blood is mainly attributed to the characteristics of the RBCs. Variations in hemorheological properties alter flow resistance and wall shear stress in blood vessels. Therefore, detailed understanding of the relationship between the hemorheological and hemodynamic properties is of great importance. In this study, blood viscosity and blood flow were simultaneously measured in the same microfluidic device by monitoring the flow-switching phenomenon. To investigate blood flows according to hemorheological variations, the flow rate of blood samples (RBCs suspended in autologous plasma, dextran-treated plasma, and in phosphate buffered saline solution) was precisely controlled with a syringe pump. Velocity profiles of blood flows were measured by using a micro-particle image velocimetry technique. The shape of velocity profiles was quantified by using a curve-fitting equation. It is found that the shape of the velocity profiles is highly correlated with blood viscosity. To demonstrate the relationship under ex vivo conditions, biophysical properties and velocity profiles were measured in an extracorporeal rat bypass loop. Experimental results show that increased blood viscosity seems to induce blunt velocity profile with high velocity component at the wall of the microchannel. Simultaneous measurement of blood viscosity and velocity profile would be useful for understanding the effects of hemorheological features on the hemodynamic characteristics in capillary blood vessels.     

The social stratification of theatre,dance and cinema attendance

In current sociological literature the relationship between social inequality and patterns of cultural taste and consumption is the subject of a large and complex debate. In this paper the primary aim is to examine, in the light of empirical results from a research project in which the authors are presently engaged, three main, and rival, positions that have been taken up in this debate, here labelled as the ‘homology’, the ‘individualization’ and the ‘omnivore–univore’ arguments. Elsewhere, we have concentrated on musical consumption in England, and find evidence that is broadly supportive of the omnivore–univore argument. Here we ask whether such findings are confirmed in the case of theatre, dance and cinema attendance. A secondary aim of the paper is to bring to the attention of practitioners in the field of cultural policy and administration the need to address the issues that arise through the use of more powerful methods of data analysis than those often applied in the past. We explain how indicators of theatre, dance and cinema attendance derived from the Arts in England survey of 2001 can be subject to analysis so as to reveal two distinctive patterns of attendance and, in turn, two distinctive types of consumer—who can, it turns out, be regarded as omnivores and univores, even if with some qualification. The former have relatively high rates of attendance at all kinds of the events covered, including musicals and pantomimes as well as plays and ballet, while the latter tend to be cinema-goers only, that is, non-consumers of theatre and dance. A range of measures of social inequality are then introduced into the authors' analyses, including separate measures of social class and social status and also of educational level and income, and it is further shown that, again in conformity with the omnivore–univore argument, these two types of consumer are socially stratified. Omnivores are of generally higher social status than univores and also have usually higher levels of education and higher income than do univores (the latter finding marking the main difference with musical consumption, which was unaffected by income once other stratification variables were controlled). In sum, our results for theatre, dance and cinema attendance lend, overall, further support to the omnivore–univore argument as against its rivals, but also indicate that different aspects of social inequality impact on different forms of cultural consumption in varying degrees and probably through largely separate processes.