Real-time lane tracking using Rao-Blackwellized particle filter

A novel approach to real-time lane modeling using a single camera is proposed. The proposed method is based on an efficient design and implementation of a particle filter which applies the concepts of the Rao-Blackwellized particle filter (RBPF) by separating the state into linear and non-linear parts. As a result the dimensionality of the problem is reduced, which allows the system to perform in real-time in embedded systems. The method is used to determine the position of the vehicle inside its own lane and the curvature of the road ahead to enhance the performance of advanced driver assistance systems. The effectiveness of the method has been demonstrated implementing a prototype and testing its performance empirically on road sequences with different illumination conditions (day and nightime), pavement types, traffic density, etc. Results show that our proposal is capable of accurately determining if the vehicle is approaching the lane markings (Lane Departure Warning), and the curvature of the road ahead, achieving processing times below 2 ms per frame for laptop CPUs, and 12 ms for embedded CPUs.     

Nanoconfined (Bio)Catalysts as Efficient Glucose‐Responsive Nanoreactors

Herein, the design, synthesis, and characterization of bifunctional hybrid nanoreactors used for concurrent one‐pot chemoenzymatic reactions are shown. In the design, the enzyme, glucose oxidase, is wrapped with a peroxidase‐mimetic catalytic polymer. Hemin, the organic catalyst, is linked to the flexible polymeric scaffold through coordination to the imidazole groups that hang out the network. This spatial arrangement, which works as a metabolic channel, is optimized for cooperative chemoenzymatic reactions in which the enzyme catalyzes first. A deep characterization of the integrated nanoreactors demonstrates that the confinement of two distinct catalytic sites in the nanospace is very effective in one‐pot reactions. Moreover, besides its role as scaffold material, the polymeric mantel protects both the biocatalyst and the chemical catalyst from degradation and inactivation in the presence of organic solvents. Furthermore, the polymeric environment of the nanoreactors can be tailored in order to trigger the assembly of those into highly active heterogeneous hybrid catalysts. Finally, the new nanoreactors are applied to the efficient degradation of organic aromatic compounds using glucose as the only fuel.     

Engineered Metal-Loaded Biohybrids to Promote the Attachment and Electron-Shuttling between Enzymes and Carbon Electrodes

The inorganic content and the catalytic performance pose metal-loaded enzyme nanoflowers as promising candidates for developing bioelectrodes capable of functioning without the external addition of a redox mediator. However, these protein-inorganic hybrids have yet to be successfully applied in combination with electrode materials. Herein, the synthesis procedure of these bionanomaterials is reproposed to precisely control the morphology, composition, and performance of this particular protein-mineral hybrid, formed by glucose oxidase and cobalt phosphate. This approach aims to enhance the adherence and electron mobility between the enzyme and a carbon electrode. The strategy relies on dressing the protein in a tailored thin nanogel with multivalent chemical motifs. The functional groups of the polymer facilitate the fast protein sequence-independent biomineralization. Furthermore, the engineered enzymes enable the fabrication of robust cobalt-loaded enzyme inorganic hybrids with exceptional protein loads, exceeding 90% immobilization yields. Notably, these engineered biohybrids can be readily deposited onto flat electrode surfaces without requiring chemical pre-treatment. The resulting bioelectrodes are robust and exhibit electrochemical responses even without the addition of a redox mediator, suggesting that cobalt complexes promote electron wiring between the active site of the enzyme and the electrode.     

Associative and orthographic neighborhood density effects in normal aging and Alzheimer’s disease.

A group of patients with Alzheimer’s disease and a group of healthy elderly controls were tested with a lexical-decision task that included words with dense or sparse orthographic and associative neighborhoods to investigate whether there is automatic orthographic and semantic activation of related representations in these populations similar to that found with younger samples. Although some studies support the idea of deteriorated connections in semantic networks in Alzheimer’s disease, other studies propose that the automatic spread of activation at lexicosemantic levels remains intact and that intergroup differences are a consequence of impaired retrieval or attentional deficits. In this study, participants responded to words with dense orthographic and associative neighborhoods faster than they did to words with sparse neighborhoods, providing evidence in favor of a preserved automatic spread of activation through intact orthographic and semantic representations. Furthermore, no differences were found between the two groups regarding the magnitude of the effects, although control participants responded significantly faster than patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Pruning Algorithm for Stable Voronoi Skeletons

We present a skeleton computation algorithm for binary image shape which is stable and efficient. The algorithm follows these steps: first the shape boundary curves are subsampled, then the Voronoi Skeleton is computed from the resulting reduced boundary set of points, and finally, a?novel two stage pruning procedure is applied to obtain a?simplified skeleton. The first stage removes skeleton edges non fully included in the shape. The second stage applies an enhanced variation of the Discrete Curve Evolution (DCE) for Voronoi skeletons. We obtain improved skeleton stability, complexity reduction and noise robustness. Pruning computing time efficiency is improved thanks to some properties of Voronoi skeletons. Entire skeleton edges can be removed or retained on the basis of conditions tested on the edge endpoints. Pattern recognition experiments and skeleton stability experiments of the algorithm outperform previous approaches in the literature.     

A 0.6 V and 0.395 pJ/bit nonius TDC for a passive RFID pressure sensor tag

This work presents a nonius time to digital converter (TDC) adapted to a passive RF identification (RFID) pressure sensor tag. The proposed converter exploits the characteristics of time-based sensor interfaces and allows reducing voltage supply and power consumption while maintaining resolution and conversion efficiency. The nonius TDC has been designed and fabricated using the TSMC 90 nm standard CMOS technology. The main blocks of the converter are described and both the resolution adjustment and measurement processes are explained in detail. Measurement results show 10.49 bits of effective resolution for an input time range from 28.19 to 42.93 μs. With a sampling rate of 19 KS/s the converter has a conversion efficiency of 0.395 pJ/bit with a voltage supply of only 0.6 V. This characteristics in the proposed nonius TDC enables an increased reading range of the passive RFID pressure sensor tag.     

Effects of ultrasonic waves on carbon dioxide solubility in brine at different pressures and temperatures

The adverse impacts of CO₂ emission on the global warming highlight the importance of carbon capture and storage technology and geological storage of CO₂ under solubility trapping mechanisms. Enhancing the solubility of CO₂ in formation water has always been the focus of research in the area of CO₂ sequestration. Ultrasound techniques are one of the environmentally friendly methods that use high-intensity acoustic waves to improve gas solubility in liquids. Ultrasonic waves can alter the properties of different phases that lead to chemical reactions and provide a means to increase the solubility of CO₂ in connate water. In this study, we investigated the effects of ultrasound on the solubility of CO₂ in connate water under different conditions of pressure, temperature, and salinity. The results showed that the solubility of CO₂ was improved with increasing pressure under ultrasonic effects. However, the solubility of CO₂ was inversely proportional to the increase in brine salinity and temperature. Therefore, it was concluded that the solubility of CO₂ might be enhanced in the presence of ultrasound.     

The relative position priming effect depends on whether letters are vowels or consonants.

The relative position priming effect is a type of subset priming in which target word recognition is facilitated as a consequence of priming the word with some of its letters, maintaining their relative position (e.g., csn as a prime for casino). Five experiments were conducted to test whether vowel-only and consonant-only subset primes contribute equally to this effect. Experiment 1 revealed that this subset priming effect emerged when primes were composed exclusively of consonants, compared with vowel-only primes (csn-casino vs. aia-animal). Experiment 2 tested the impact of letter frequency in this asymmetry. Subset priming effects were obtained for both high- and low-frequency consonants but not for vowels, which rules out a letter frequency explanation. Experiment 3 tested the role of phonology and its contribution to the priming effects observed, by decreasing the prime duration. The results showed virtually the same effects as in the previous experiments. Finally, Experiments 4 and 5 explored the influence of repeated letters in the primes on the magnitude of the priming effects obtained for consonant and vowel subset primes (iuo-dibujo and aea-madera vs. mgn-imagen and rtr-frutero). Again, the results confirmed the priming asymmetry. We propose that a functional distinction between consonants and vowels, mainly based on the lexical constraints imposed by each of these types of letters, might provide an explanation for the whole set of results. (PsycINFO Database Record (c) 2011 APA, all rights reserved)