TGFbeta affects collagen cross-linking independent of chondrocyte phenotype but strongly depending on physical environment

Transforming growth factor beta (TGFbeta) is often used in cartilage tissue engineering to increase matrix formation by cells with various phenotypes. However, adverse effects of TGFbeta, such as extensive cross-linking in cultured fibroblasts, have also been reported. Our goal was to study effects of TGFbeta on collagen cross-linking and...

Forward and inverse modeling of near-well flow using discrete edge-based vector potentials

Homogeneous effective permeabilities in the near-well region are generally obtained using analytical solutions for transient flow. In contrast, this paper focuses on heterogeneous permeability obtained from steady flow solutions, although extensions to unsteady flow are introduced too. Exterior calculus and its discretized form have been used as...

Algebraic software analysis and embedded simulation of a driving robot

At TNO Automotive the Generic Driving Actuator (GDA) is developed. The GDA is a device capable of driving a vehicle fully automatically using the same interface as a human driverdoes. In this paper, the design of the GDA is discussed. The software and hardware of the GDA and its effect on vehicle behaviour are analyzed from a safety point of...

Colorizing single band intensified nightvision images

We present a method to give single band intensified nightvision imagery a natural day-time color appearance. For input, the method requires a true color RGB source image and a grayscale nightvision target image. The source and target image are both transformed into a perceptually decorrelated color space. In this color space a best matching...

Robust spectral factor approximation of discrete-time frequency domain power spectras

This paper presents a subspace-based identification algorithm for estimating the state-space quadruple [A,B,C,D] of a minimum-phase spectral factor from matrix-valued power spectrum data. For a given pair [A,C] with A stable, the minimum-phase property is guaranteed via the solution of a conic linear programming (CLP) problem. In comparison with...

Net analyte signal based statistical quality control

Net analyte signal statistical quality control (NAS-SQC) is a new methodology to perform multivariate product quality monitoring based on the net analyte signal approach. The main advantage of NAS-SQC is that the systematic variation in the product due to the analyte (or property) of interest is separated from the remaining systematic variation...

Adjoint method for missile performance analysis on state-space models

The adjoint method is a method widely used in the preliminary design of guidance loops to obtain quick estimates of the performance of a guided weapon while avoiding time consuming Monte Carlo simulation experiments. Traditionally, the adjoint method is presented as a set of rules for transforming the original (linearized) model of the guidance...

Phased arrays of rectangular apertures on conformal cylindrical surfaces: A multimode equivalent network approach

In this paper, we present an efficient integral equation formulation based on a multimode equivalent network (MEN) approach for the analysis of phased arrays on cylindrical surfaces using open-ended waveguide radiators. In addition to theory, experimental data are also presented showing very good agreement with simulated results. © 2004 IEEE.

A Two-Stage Method for Determining the Position and Corresponding Precision of Marine Mammal Sounds; 2004BU1-OT

Today there is a concern that man-made sounds, such as that from sonar experiments, seismic operations and oil rigs, affect marine mammals. Detection and localisation of marine mammals will definitely support measures to reduce the possible detrimental effects. This paper presents a two-stage localisation method, which is applied to data...

Vehicle ego-motion estimation with geometric algebra

A method for estimating ego-motion with vehicle mounted stereo cameras is presented. This approach is based on finding corresponding features in stereo images and tracking them between succeeding stereo frames. Our approach estimates stereo ego-motion with geometric algebra techniques. Starting with a simple linear estimate of the ego-motion,...

Dealing with friction in a reusable 6 degrees of freedom adjustment mechanism with sliding contacts

Although the possibility of a 6 degrees of freedom adjustment based on a single body pulled onto on six adjustable supports follows directly from the kinematic theory, such mechanisms are seldom used in actual products. Two major drawbacks for the use of this solution are: Due to the sliding contact between the body and the supports, friction...

A modified RRSQRT-filter for assimilating data in atmospheric chemistry models

The RRSQRT-filter is a special formulation of the Kalman filter for assimilation of data in large scale models. In this formulation, the covariance matrix of the model state is expressed in a limited number of modes. Two modifications have been made to the filter such that it is more robust when applied in combination with an atmospheric...

Engineering Multirate Convolutions for Radar Imaging

We present a schematic design methodology for multirate convolution systems, based on combined algorithmic development and architecture design. It allows us to map the algebraic specification of a long convolution algorithm directly onto efficient fast convolution hardware based on short FFT processor elements or dedicated VLSI processors. The...

The penetration depth in modelling natural groundwater flow

In this paper, we present a method that may lead to a better quantitative insight into the relation between the size (horizontal dimensions) of a natural groundwater flow modelling area and the schematization required for a numerical model. The method is based on a decomposition of the spatial variability of the groundwater table into a Fourier...

Determination of the elastic constants of some composites by using ultrasonic velocity measurements

An ultrasonic immersion technique was used to determine the velocity and amplitude of sound waves in composite materials. The materials under study were E-glass/IPN, E-glass/PET, Kevlar 29/IPN, Dyneema/PE and Dyneema/Kraton. The velocity and amplitude of longitudinal and transverse sound waves at the frequency of 1 MHz were measured in three...

An analysis of element-by-element preconditioners for nonsymmetric problems

A group of preconditioners for systems of linear equations arising from finite element discretization, which is of increasing interest, is the class of element-by-element preconditioners. These preconditioners allow the solution of a system without the need to assemble the global stiffness matrix. The success of a preconditioner depends on how...