Lossless subband coding system based on rounding transform

We propose a new rounding transform called the overlapping rounding transform (ORT). It is defined as a two-port input/two-port output FIR filtering system with a pair of rounding operations. The ORT is applied to develop lossless subband coding systems. The ORT approach has both a simpler representation and more possibilities for lossless subband implementation than the lifting scheme     

Hyperparameter estimation for satellite image restoration using a MCMC maximum-likelihood method

The satellite image deconvolution problem is ill-posed and must be regularized. Herein, we use an edge-preserving regularization model using a ? function, involving two hyperparameters. Our goal is to estimate the optimal parameters in order to automatically reconstruct images. We propose to use the maximum-likelihood estimator (MLE), applied to the observed image. We need sampling from prior and posterior distributions. Since the convolution prevents use of standard samplers, we have developed a modified Geman-Yang algorithm, using an auxiliary variable and a cosine transform. We present a Markov chain Monte Carlo maximum-likelihood (MCMCML) technique which is able to simultaneously achieve the estimation and the reconstruction.     

Specificity of antiperinuclear factor for rheumatoid arthritis in rheumatoid factor-positive sera

Although antiperinuclear factor (APF) has the same specificity for rheumatoid arthritis (RA) as rheumatoid factor (RF), there is no evidence that this specificity is maintained in patients with positive RF-agglutination tests. Thus, we evaluated the specificity and usefulness of APF for RA diagnosis, regardless of RF titre. APF was tested (1:100 threshold) on 214 sera sent for RF evaluation over a 9-month period. These sera were previously determined to have latex or Rose-Waaler (RW) titres > or = 12 or 4 IU, respectively, but not necessarily above the threshold values of 100 and 32 IU. The APF test was performed blindly, and physicians were not advised of the results. In the patient population (119 RA and 95 non-RA) APF still demonstrated good specificity (0.82) for RA. As expected, APF proved useful for RA diagnosis in 28/33 (85%) RA cases with an RF level below 1:100 for latex and 1:32 for RW, thus reducing the number of 'seronegative' RA from 33/119 to 5/119. However, it also improved the serological positive predictive value for RA, even in cases when RW results were > or = 32 IU. Indeed, the positive predictive value for RA when both tests were positive was 0.94 (68/72), whereas concordant results (either positive or negative) for both APF and RW tests allowed correct classification (RA or non-RA) in 94% of cases.     

An Experimental Approach for the Characterisation of Rigid Porous Media and Unsaturated Conductivity Relations

A laboratory procedure for the characterisation of rigid, porous media is developed and tested. The overall objective of the characterisation is to provide a basis for the choice of a relevant unsaturated conductivity relation. With the proposed procedure, the porous materials are characterised through hydraulic conductivity measurements, saturation-pressure measurements, porosity measurements and air entry pressure measurements. The measurements were conducted using water and a selected non-aqueous phase liquid (n-decane), and two types of homogeneous, rigid porous media of different origin (fritted glass samples with guaranteed homogeneity by the manufacturer, and chalk). The laboratory method successfully characterised the fritted glass samples as homogeneous on basis of calculated tortuosity values, measured bubble pressures and measured pore-size density curves. The contact angle between the liquid and the solid had negligible impact when comparing the drainage of water with the drainage of n-decane, and also when comparingn -decane drainage in dry porous media withn -decane drainage in media where a film of water separated then -decane from the pore wall. Also, the differences in saturated conductivities between n-decane and water in both samples of chalk and fritted glass were well predicted on basis of differences in density and viscosity of the liquids. The laboratory procedure was furthermore used for characterisation of the pore space available for non-aqueous liquid flow in partially water-saturated porous media. Then -decane conductivities in the fritted glass samples partially saturated with water were considerably lower than the n-decane conductivities in the dry fritted glass samples.     

Investigation of charge carrier depletion in freestanding nanowires by a multi-probe scanning tunneling microscope

Profiling of the electrical properties of nanowires (NWs) and NW heterocontacts with high spatial resolution is a challenge for any application and advanced NW device development. For appropriate NW analysis, we have established a four-point prober, which is combined in vacuo with a state-of-the-art vapor-liquid-solid preparation, enabling contamination-free NW characterization with high spatial resolution. With this ultrahigh-vacuum-based multi-tip scanning tunneling microscopy (MT-STM), we obtained the resistance and doping profiles of freestanding NWs, along with surface-sensitive information. Our in-system 4-probe STM approach decreased the detection limit for low dopant concentrations to the depleted case in upright standing NWs, while increasing the spatial resolution and considering radial depletion regions, which may originate from surface changes. Accordingly, the surface potential of oxide-free GaAs NW {112} facets has been estimated to be lower than 20 mV, indicating a NW surface with very low surface state density.

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Variational implicit surface meshing

In this paper, we propose a new algorithm to mesh implicit surfaces which produces meshes both with a good triangle aspect ratio as well as a good approximation quality. The number of vertices of the output mesh is defined by the end-user. For this goal, we perform a two-stage processing: an initialization step followed by an iterative optimization step. The initialization step consists in capturing the surface topology and allocating the vertex budget. The optimization algorithm is based on a variational vertices relaxation and triangulation update. In addition a gradation parameter can be defined to adapt the mesh sampling to the curvature of the implicit surface. We demonstrate the efficiency of the approach on synthetic models as well as real-world acquired data, and provide comparisons with previous approaches.     

Generic remeshing of 3D triangular meshes with metric-dependent discrete voronoi diagrams

In this paper, we propose a generic framework for 3D surface remeshing. Based on a metric-driven Discrete Voronoi Diagram construction, our output is an optimized 3D triangular mesh with a user defined vertex budget. Our approach can deal with a wide range of applications, from high quality mesh generation to shape approximation. By using appropriate metric constraints the method generates isotropic or anisotropic elements. Based on point-sampling, our algorithm combines the robustness and theoretical strength of Delaunay criteria with the efficiency of entirely discrete geometry processing . Besides the general described framework, we show experimental results using isotropic, quadric-enhanced isotropic and anisotropic metrics which prove the efficiency of our method on large meshes, for a low computational cost.     

Effect of the doping time of the 1‐butyl‐3‐methylimidazolium ionic liquid cation on the Nafion membrane proprieties

Nafion membranes were prepared by incorporating in the polymer matrix the 1‐butyl‐3‐methylimidazolium (BMI⁺) ionic liquid cation at different doping levels. Increasing the doping time of the membranes with the ionic liquid results in increased incorporation of the BMI⁺ cation but a decrease in the bulk conductivity. The thermogravimetric analysis shows that the BMI⁺ cation incorporation increases the thermal stability of the membranes. The higher discharge efficiency of the fuel cell at 80°C was obtained by using Nafion membrane after 15 minutes of doping in the ionic liquid solution.     

Effects of the smoking process on odour characteristics of smoked herring (Clupea harengus) and relationships with phenolic compound content

The relationship between smoking parameters and odour characteristics, evaluated by a trained sensory panel, were studied on smoked herring. In addition, a possible correlation between the content of 10 phenolic compounds and sensory perceptions was investigated. Five smoking techniques were applied, combining smoke production conditions, performed by pyrolysis of beech wood sawdust or by friction of beech wood log, with smoke deposition, either in a controlled kiln (traditional smoking) or by an electrostatic process. In the fifth smoking technique, a purified condensate of beech smokes was vaporised on fish fillets in the smokehouse. The time of smoking was 3 h for traditional smoking and the liquid smoke atomisation process and 12 min for the electrostatic method. The effects of three smoking temperatures (16, 24, 32 °C) were tested for both the traditional and the liquid smoke atomisation processes, as well as the effect of the position of the exhaust valve in the smokehouse in the case of the traditional method. Two different voltages were applied for the electrostatic process, 37 and 42 kV.