Effect of field-dependent mobility on m.o.s. transistor characteristics

The authors calculate the characteristics of m.o.s.t.s, taking full account of the surface electric-field dependence of mobility in the channel, which is very significant for thin-oxide or high-gate-voltage devices. An approximation is used for the average effect of background ionised impurity charge. Fields along the channel are assumed to have a negligible influence on mobility.     

Data-driven latent-variable model-based predictive control for continuous processes

A model-based predictive control methodology in the space of the latent variables for continuous processes is presented. Implementing identification and control in the latent variable space eases identification in the case of correlation in the data set, acts as a prefilter reducing the effect of noisy data, and reduces computational complexity. The proposed data-driven LV-MPC approach deals with setting the control horizon different to the prediction horizon, improves Hessian conditioning, and attains offset-free tracking. Additionally, a weighting matrix is introduced in the identification stage so that the performance of the predictor in the near horizon can be enhanced. A MIMO example shows how the proposed methodology can outperform conventional data-driven MPC in terms of computational complexity and reference tracking.     

Latent variable based model predictive control: Ensuring validity of predictions

This paper presents a methodology to constrain the optimisation problem in LV-MPC so that validity of predictions can be ascertained. LV-MPC is a model-based predictive control methodology implemented in the space of the latent variables and is based on a linear predictor. Provided real processes are non-linear, there is model-process mismatch, and under tight control, the predictor can be used for extrapolation. Extrapolation leads to bad predictions which deteriorates control performance, hence the interest in validity of predictions. In the proposed approach first two validity indicators on predictions are defined. The novelty in the two indicators proposed is they neglect past data, and so validity of predictions is ascertained in terms of future moves which are actually the degrees of freedom in the optimisation. Second, the indicators are introduced in the optimisation as constraints. Provided the indicators are quadratic, recursive optimisation with linearised constraints is implemented. A MIMO example shows how ensuring validity of predictions neglecting past data can improve closed-loop performance, specially under tight control outside the identification region.     

Expression of TRPV4 in the zebrafish retina during development

The transient receptor potential (TRP) channels are involved in sensing mechanical/physical stimuli such as temperature, light, pressure, as well as chemical stimuli. Some TRP channels are present in the vertebrate retina, and the occurrence of the multifunctional channel TRP vanilloid 4 (TRPV4) has been reported in adult zebrafish. Here, we investigate the expression and distribution of TRPV4 in the retina of zebrafish during development using polymerase chain reaction (PCR), Western blot, and immunohistochemistry from 3 days post fertilization (dpf) until 100 dpf. TRPV4 was detected at the mRNA and protein levels in the eye of zebrafish at all ages sampled. Immunohistochemistry revealed the presence of TRPV4 in a population of the retinal cells identified as amacrine cells on the basis of their morphology and localization within the retina, as well as the co-localization of TRPV4 with calretinin. TRPV4 was first (3 dpf) found in the soma of cells localized in the inner nuclear and ganglion cell layers, and thereafter (10 dpf) also in the inner plexiform layer. The adult pattern of TRPV4 expression was achieved by 40 dpf the expression being restricted to the soma of some cells in the inner nuclear layer and ganglion cell layers. These data demonstrate the occurrence and developmental changes in the expression and localization of TRPV4 in the retina of zebrafish, and suggest a role of TRPV4 in the visual processing.     

A simulation tool for the analysis and verification of the steady state of circuit designs

Analogue and microwave design requires accurate and reliable simulation tools and methods to meet the design specifications. System properties are often measured in the steady state. Well-suited algorithms for calculating the steady state can be classified into shooting methods, finite difference methods and the harmonic balance (HB) technique. Harmonic balance is a frequency domain method which approaches the problem of finding the steady state by a trigonometric polynomial. Depending on the size of the circuit and the number of Fourier coefficients of the polynomial, the resulting system of non-linear equations can become very large. These non-linear equations are solved by using Newton's method. The sparse linear system arising from Newton's method can be solved by direct, stationary or non-stationary iterative solvers. Iterative methods are normally easy to parallelize or vectorize. In this paper a tool for the simulation of the steady state of electronic circuits is presented. the steady state is calculated using the harmonic balance technique. Non-linear equations are solved by Newton's method and linear equations by preconditioned non-stationary iterative solvers (CGS, Bi-CGSTAB, BiCGSTAB(2), TFQMR). the run time is reduced dramatically, by up to an order of magnitude.     

Ray Differentials and Multiresolution Geometry Caching for Distribution Ray Tracing in Complex Scenes

When rendering only directly visible objects, ray tracing a few levels of specular reflection from large, low‐curvaturesurfaces, and ray tracing shadows from point‐like light sources, the accessed geometry is coherentand a geometry cache performs well. But in many other cases, the accessed geometry is incoherent and a standardgeometry cache performs poorly: ray tracing of specular reflection from highly curved surfaces, tracing rays thatare many reflection levels deep, and distribution ray tracing for wide glossy reflection, global illumination, widesoft shadows, and ambient occlusion. Fortunately, less geometric accuracy is necessary in the incoherent cases.This observation can be formalized by looking at the ray differentials for different types of scattering: coherentrays have small differentials, while incoherent rays have large differentials. We utilize this observation to obtainefficient multiresolution caching of geometry and textures (including displacement maps) for classic and distributionray tracing in complex scenes. We use an existing multiresolution caching scheme (originally developed forscanline rendering) for textures and displacement maps, and introduce a multiresolution geometry caching schemefor tessellated surfaces. The multiresolution geometry caching scheme makes it possible to efficiently render scenesthat, if fully tessellated, would use 100 times more memory than the geometry cache size.     

Correlation between int-2 oncogene amplification and increased tumor size in breast cancer]

Gloves should provide two-way protection from the transmission of microorganisms between worker and patient. Until recently, glove manufacturers paid little attention to barrier properties. Because the operating room is a high-risk area, surgical nurses must be especially careful about gloving practices.     

Influence of substrate on the pulsed laser deposition growth and microwave behaviour of KTa0.6Nb0.4O3 potassium tantalate niobate ferroelectric thin films

Thin films of potassium tantalate niobate KTa_0.6Nb_0.4O₃ (KTN) were grown by pulsed laser deposition on five different substrates suitable for microwave devices: (100)MgO, (100)LaAlO₃, (1–102)sapphire (R-plane), (0001)sapphire (C-plane) and alumina. The high volatility of potassium at the film growth temperature required the addition of an excess of potassium to the ablation target. For optimized deposition conditions, Rutherford backscattering showed that the KTN films had a 1: 1 atomic ratio for K:(Nb + Ta). As grown KTN thin films were single-phase, without any particular orientation on sintered alumina, whereas an epitaxial growth with the (100) orientation was achieved on (100)MgO and (100)LaAlO₃ with a mosaicity Δω_(100)KTN close to 0.7°–1.5° and  0.4°–0.9°, respectively, attesting a high crystalline quality. In contrast, growth of KTN on R-plane sapphire results in a texture with the (100) orientation and the presence of the (110) orientation as a secondary one. The room temperature measurements carried out on Au interdigited capacitors patterned on KTN coated (100) LaAlO₃ and sapphire led at 1 GHz to an agility ΔC / C  4.6% and  7.2%, respectively, for a moderate applied field of 15 kV cm^− 1. Stubs patterned on the same systems led to an agility ΔF_r / F_r of  2.2% and 4.2%, respectively, for F_r = 7 GHz and the same applied field.