Combining Invariant Features and the ALV Homing Method for Autonomous Robot Navigation Based on Panoramas

Biologically inspired homing methods, such as the Average Landmark Vector, are an interesting solution for local navigation due to its simplicity. However, usually they require a modification of the environment by placing artificial landmarks in order to work reliably. In this paper we combine the Average Landmark Vector with invariant feature points automatically detected in panoramic images to overcome this limitation. The proposed approach has been evaluated first in simulation and, as promising results are found, also in two data sets of panoramas from real world environments.     

Parameterization of an acousto-optic programmable dispersive filter for closed-loop learning experiments

A representation of the search space in optical pulse shaping problems employing an acousto-optic programmable dispersive filter (AOPDF) is presented for use in closed-loop learning experiments where the optimal spectral phase function to some control problem is determined by an iterative learning algorithm. The representation allows the algorithm to select a value for the optical chirp at each frequency control point such that only acoustic grating functions which preserve the spectrum of the shaped pulses are tested. The limits of this space with respect to the rate of applied optical chirp, optical bandwidth and acoustic power are examined and tested through diffraction efficiency studies performed using a commercial AOPDF. The main benefits of this representation are the elimination of undesirable frequency mixing effects, reduction of diffraction efficiency variation between arbitrary pulse shapes and faster convergence of the evolutionary algorithm.     

A variational multiscale method for incompressible turbulent flows: Bubble functions and fine scale fields

This paper presents a residual-based turbulence model for the incompressible Navier–Stokes equations. The method is derived employing the variational multiscale (VMS) framework. A multiscale decomposition of the continuous solution and a priori unique decomposition of the admissible spaces of functions lead to two coupled nonlinear problems termed as the coarse-scale and the fine-scale sub-problems. The fine-scale velocity field is assumed to be nonlinear and time-dependent and is modeled via the bubble functions approach applied directly to the fine-scale sub-problem. A significant contribution in this paper is a systematic and consistent derivation of the fine-scale variational operator, commonly termed as the stabilization tensor that possesses the right order in the advective and diffusive limits, and variationally projects the fine-scale solution onto the coarse-scale space. A direct treatment of the fine-scale problem via bubble functions offers several fine-scale approximation options with varying degrees of mathematical sophistication that are investigated via benchmark problems. Numerical accuracy of the proposed method is shown on a forced-isotropic turbulence problem, statistically stationary turbulent channel flow problems at Re_T = 395 and 590, and non-equilibrium turbulent flow around a cylinder at Re = 3,900.     

Increased sensitivity for the diagnosis of Taenia saginata cysticercus infection by additional heart examination compared to the EU-approved routine meat inspection

In spite of the statutory meat inspection at abattoirs, Taenia saginata cysticercus infection in cattle remains an economically important parasitic disease for the livestock industry by affecting food safety. The routinely performed standard meat inspection protocol has a low diagnostic sensitivity for the detection of T. saginata cysticerci infections. Therefore, an abattoir trial aiming to increase the detection level was undertaken. In three EU-approved abattoirs, several additional heart incisions were performed in a total of 1088 slaughtered cattle originating from 832 farms throughout Switzerland. Cysticerci as putative parasitic lesions were classified by visual examination during meat inspection and confirmed microscopically and/or by molecular analyses. With the EU-approved routine meat inspection, bovine cysticercosis was diagnosed in 1.8% (20/1088) of the slaughtered animals. Additional incisions into the heart muscle revealed a further 29 cases, indicating that the prevalence was at least 4.5%. All infected animals originated from individual farms. This straightforward technique had a significantly higher sensitivity and is feasible for routine practice. It also confirms that the prevalence of this zoonotic parasite in the cattle population is underestimated based on the routine abattoir reports.     

Diminished organelle motion in murine Kupffer cells during the erythrocytic stage of malaria

Parasitized erythrocytes are ingested by murine hepatic macrophages during malaria infection. We non-invasively monitored how this altered the motion of intracellular phagosomes in Kupffer cells using magnetometry. Submicrometric γFe₂O₃ particles were injected prior to malaria infection. They were cleared from the blood, primarily by Kupffer cells, and retained within their phagosomes. The mice were periodically magnetized. After removing this external magnet, the aligned iron particles created a remnant magnetic field (RMF) which then decayed (relaxation), reflecting the motion of particle-containing phagosomes. After baseline measurements of relaxation, the mice were injected intravenously with Plasmodium chabaudi-parasitized or normal murine red blood cells (RBCs). During the next 15 days, relaxation measurements, parasitaemia and haematocrit values were monitored. At 6 days post injection with 3 × 10⁷ parasitized RBCs, relaxation rates had decreased. At this time, all mice had parasitaemias greater than 58 per cent and haematocrits less than 20 per cent. At day 7, while the parasitaemias were declining, the rate of relaxation continued to decrease. Throughout the experiment, relaxation remained constant in animals injected with normal RBCs. Electron microscopy revealed Kupffer cells filled with damaged and parasitized erythrocytes, and haemoglobin degradation pigment. We conclude that ingestion and metabolism of parasitized erythrocytes by liver macrophages during malaria infection decreases their organelle motion with likely consequences of compromised host defences.     

High efficiency and reusability of iridium complexes adsorbed in montmorillonite clay on catalytic hydrogenation of imines

Heterogenised homogeneous catalytic hydrogenation of aldimines by removable and reusable immobilised iridium complexes on montmorillonite clay. This revised version was published online in July 2006 with corrections to the Cover Date.     

Capacity and interference statistics of highways W-CDMAcigar-shaped microcells (uplink analysis)

The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied. A model of five cells is used to analyze the uplink. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the cell are studied using a two-slope propagation model. The expected value and the variance of the interference are given for different propagation exponent     

Social class, education, and smoking cessation: Long-term follow-up of patients treated at a smoking cessation unit.

Our objective was to examine social class and educational differences in long-term smoking cessation success among a cohort of smokers attending a specialized smoking clinic. We studied sustained abstinence after cessation among 1,516 smokers (895 men and 621 women) treated for smoking cessation between 1995 and 2001 at a university teaching hospital in the metropolitan area of Barcelona, Spain. We calculated 1-year and long-term (up to 8-year) abstinence probabilities by means of Kaplan-Meier curves and the hazard ratio of relapse by means of Cox regression, after adjusting for other predictors of relapse. Overall abstinence probability was .277 (95% CI = .254-.301). Men and women in social classes IV-V had significant hazard ratios of relapse after long-term follow-up (men: 1.36, 95% CI = 1.07-1.72; women: 1.60, 95% CI = 1.24-2.06), as compared with patients in social classes I-II. The same independent effect was observed for education: Men and women with primary or less than primary studies had higher hazard ratios of relapse (men: 1.75, 95% CI = 1.35-2.25; women: 1.92, 95% CI = 1.51-2.46), as compared with patients with a university degree. Similar estimates were obtained after adjustment for stage of change, Fagerstr?m score for nicotine dependence, and type of treatment. Patients of lower socioeconomic status are at higher risk of relapse, and this association is independent of other well-known predictors of relapse. Social differences have to be taken into account in the clinical setting when tailoring specific actions to treat smoking dependence.     

Performance assessment of intelligent distributed systems through software performance ontology engineering (SPOE)

In the computer science community there is a growing interest in the field of Ambient Intelligent Systems. This systems surround their human users with computing and networking technology unobtrusively embedded in their environment. This technology is aimed to provide the users with useful information and to take action to make the environment more convenient for them. As the number of users increases the resources that make Ambient Intelligence possible can be easily saturated making the system unstable and projecting an image of poor QoS to the users. The main goal of this paper is to provide the means for the Ambient Intelligent Systems to monitor themselves and take corrective action automatically if performance starts to drop. Our approach uses a Performance Ontology that structures the knowledge about Software Performance Engineering, and a reasoning engine that acts like an expert system with the Performance Ontology as its foundation. The case study at the end shows the applicability of the developed techniques.