A cut finite element method for coupled bulk-surface problems on time-dependent domains

In this contribution we present a new computational method for coupled bulk-surface problems on time-dependent domains. The method is based on a space-time formulation using discontinuous piecewise linear elements in time and continuous piecewise linear elements in space on a fixed background mesh. The domain is represented using a piecewise linear level set function on the background mesh and a cut finite element method is used to discretize the bulk and surface problems. In the cut finite element method the bilinear forms associated with the weak formulation of the problem are directly evaluated on the bulk domain and the surface defined by the level set, essentially using the restrictions of the piecewise linear functions to the computational domain. In addition a stabilization term is added to stabilize convection as well as the resulting algebraic system that is solved in each time step. We show in numerical examples that the resulting method is accurate and stable and results in well conditioned algebraic systems independent of the position of the interface relative to the background mesh

Different features in Wegener's granulomatosis: Report of five cases

Wegener's granulomatosis (WG) is an autoimmune inflammatory condition. It is often a rapidly progressive and potentially fatal disease. The clinical presentation of WG can be so diverse that the list of its differential diagnosis is vast, ranging from infectious diseases to other vasculitis (e.g. Behcet's disease), as well as malignancies. The exact aetiology of WG remains unclear. The upper airway diseases including sinusitis, oral lesions and otitis media are the most common presenting features of WG. In this paper, we have described 5 WG cases. They had different presentations and chief complaints. Some of them presented with upper airways diseases, while the others mainly suffered from the manifestations of pulmonary involvement. Although all of them were finally diagnosed as WG cases, the processes of the work up for the diagnosis as well as the outcome of the disease were not the same. So, the diversities in the presentation should be mentioned in the management of the WG suspected patients

Full Gradient Stabilized Cut Finite Element Methods for Surface Partial Differential Equations

We propose and analyze a new stabilized cut finite element method for the Laplace-Beltrami operator on a closed surface. The new stabilization term provides control of the full $\mathbb{R}^3$ gradient on the active mesh consisting of the elements that intersect the surface. Compared to face stabilization, based on controlling the jumps in the normal gradient across faces between elements in the active mesh, the full gradient stabilization is easier to implement and does not significantly increase the number of nonzero elements in the mass and stiffness matrices. The full gradient stabilization term may be combined with a variational formulation of the Laplace-Beltrami operator based on tangential or full gradients and we present a simple and unified analysis that covers both cases. The full gradient stabilization term gives rise to a consistency error which, however, is of optimal order for piecewise linear elements, and we obtain optimal order a priori error estimates in the energy and $L^2$ norms as well as an optimal bound of the condition number. Finally, we present detailed numerical examples where we in particular study the sensitivity of the condition number and error on the stabilization parameter.Comment: 20 pages, 4 figures, 5 tables. arXiv admin note: text overlap with arXiv:1507.0583

A Theory of Cheap Control in Embodied Systems

We present a framework for designing cheap control architectures for embodied agents. Our derivation is guided by the classical problem of universal approximation, whereby we explore the possibility of exploiting the agent's embodiment for a new and more efficient universal approximation of behaviors generated by sensorimotor control. This embodied universal approximation is compared with the classical non-embodied universal approximation. To exemplify our approach, we present a detailed quantitative case study for policy models defined in terms of conditional restricted Boltzmann machines. In contrast to non-embodied universal approximation, which requires an exponential number of parameters, in the embodied setting we are able to generate all possible behaviors with a drastically smaller model, thus obtaining cheap universal approximation. We test and corroborate the theory experimentally with a six-legged walking machine. The experiments show that the sufficient controller complexity predicted by our theory is tight, which means that the theory has direct practical implications. Keywords: cheap design, embodiment, sensorimotor loop, universal approximation, conditional restricted Boltzmann machineComment: 27 pages, 10 figure

Yield and yield components of six canola (Brassica napus L.) cultivars affected by planting date and water deficit stress

In order to study the effect of planting dates and different irrigation regimes on yield and yield components of six canola cultivars, an experiment was conducted in two growing seasons; 2008 to 2009 and 2009 to 2010. Six canola cultivars (Zarfam, GKH1103, GKH1605, GKH2005, GKH305 and GKH3705) were cultivated in two different dates (October 7th and November 6th) with two levels of irrigation regimes (irrigation after 60 mm evaporation from Class A evaporation pan and irrigation interrupting at flowering stage). The experiments were conducted in randomized complete block design arrangement in split factorial with four replications The results demonstrated that late planting date and interrupting of irrigation at flowering stage significantly decreased growth, yield and yield components the of canola cultivars. In addition, oil yield was affected by late planting and water stress and it was dramatically decreased. Also, there was no significant difference among the cultivars with respect to oil percentage. The highest seed yield (5930.4 kg. ha-1) was obtained from GKH1103 cultivars planted on October 7th under the conditions of full irrigation. Seed yield and oil yield in the second year was more than that of the first year; this increase was related to the increase in seed weight and pod number per plant but not to number of seed per pod. In general, canola cultivation on November 6th considerably decreased seed and oil yield and it is an important point to achieve desirable yield to seed sowing not done later than October 7th. Additionally, complementary irrigation was very important to gain high yield in canola under the conditions of this study.Key words: Canola, planting date, water stress, yield and yield components

Oil removal from water oil emulsions using magnetic nanocomposite fibrous mats

Herein we present the fabrication of hydrophobic and oleophilic poly(methyl methacrylate) based nanocomposite fibrous mats with magnetic properties, and their utilization for oil removal from stable water oil emulsions