Context-Based Path Prediction for Targets with Switching Dynamics

International Journal of Computer Vision - Anticipating future situations from streaming sensor data is a key perception challenge for mobile robotics and automated vehicles. We address the problem...     

3D Human model adaptation by frame selection and shape–texture optimization

We present a novel approach for 3D human body shape model adaptation to a sequence of multi-view images, given an initial shape model and initial pose sequence. In a first step, the most informative frames are determined by optimization of an objective function that maximizes a shape–texture likelihood function and a pose diversity criterion (i.e. the model surface area that lies close to the occluding contours), in the selected frames. Thereafter, a batch-mode optimization is performed of the underlying shape- and pose-parameters, by means of an objective function that includes both contour and texture cues over the selected multi-view frames.Using above approach, we implement automatic pose and shape estimation using a three-step procedure: first, we recover initial poses over a sequence using an initial (generic) body model. Both model and poses then serve as input to the above mentioned adaptation process. Finally, a more accurate pose recovery is obtained by means of the adapted model.We demonstrate the effectiveness of our frame selection, model adaptation and integrated pose and shape recovery procedure in experiments using both challenging outdoor data and the HumanEva data set.     

Real-time dense stereo for intelligent vehicles

Stereo vision is an attractive passive sensing technique for obtaining three-dimensional (3-D) measurements. Recent hardware advances have given rise to a new class of real-time dense disparity estimation algorithms. This paper examines their suitability for intelligent vehicle (IV) applications. In order to gain a better understanding of the performance and the computational-cost tradeoff, the authors created a framework of real-time implementations. This consists of different methodical components based on single instruction multiple data (SIMD) techniques. Furthermore, the resulting algorithmic variations are compared with other publicly available algorithms. The authors argue that existing publicly available stereo data sets are not very suitable for the IV domain. Therefore, the authors' evaluation of stereo algorithms is based on novel realistically looking simulated data as well as real data from complex urban traffic scenes. In order to facilitate future benchmarks, all data used in this paper is made publicly available. The results from this study reveal that there is a considerable influence of scene conditions on the performance of all tested algorithms. Approaches that aim for (global) search optimization are more affected by this than other approaches. The best overall performance is achieved by the proposed multiple-window algorithm, which uses local matching and a left-right check for a robust error rejection. Timing results show that the simplest of the proposed SIMD variants are more than twice as fast than the most complex one. Nevertheless, the latter still achieves real-time processing speeds, while their average accuracy is at least equal to that of publicly available non-SIMD algorithms.     

Specific characteristics of infrared spectra of irradiated γ-polypropylene

Nonvolatile products have been identified that arise through γ-irradiation in isotactic polypropylene by Fourier transform infrared (FTIR) analysis. The γ-irradiation was performed in the air with doses varying between 20 and 1200 kGy, for a dose rate of 800 Gy/h. The contour lines of FTIR absorption bands of carbonyl groups at different region of the cross section of an irradiated sample have been determined. The carbonyl groups arise from the concentration of esters or ketones, carboxylic acids, and γ-lactones, but their structure is different for different doses. We have also investigated the degradation of irradiated polypropylene by using FTIR mappings. Dust particles of irradiated brittle polypropylene have also been studied. The gel fraction has been determined for different doses of irradiation, and the relation between the moment of the appearance of the gel and disappearance of the carbonyl groups has been made evident. © 1996 John Wiley & Sons, Inc.     

Sensor-based pedestrian protection

Pedestrian accidents represent the second-largest source of traffic-related injuries and fatalities, after accidents involving car passengers. Children are especially at risk. A complementary approach to accident prevention is to focus on sensor-based solutions, which let vehicles "look ahead" and detect pedestrians in their surroundings. The article investigates the state of the art in this domain, reviewing passive, video based approaches and approaches involving active sensors (radar and laser range finders).     

Neurochemical basis of conditioned partner preference in the female rat: II. Disruption by flupenthixol.

The effects of the dopamine receptor antagonist flupenthixol were examined on the development of conditioned partner preference induced by paced copulation in female rats. In Experiment 1, ovariectomized, hormone-primed rats were conditioned to associate scented and unscented males with paced and nonpaced copulation, respectively. Females in Experiment 2 associated albino or pigmented males with paced or nonpaced copulation. Flupenthixol or saline was administered before each conditioning trial. During a final drug-free preference test, females could choose to copulate with either a pacing-related or nonpacing-related male. Saline-trained females copulated preferentially with the pacing-related male, whereas flupenthixol disrupted odor but not strain conditioning. The role of dopamine in conditioned partner preference depends on the type of stimuli to be learned. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anti-fog chitosan/sodium lauryl ether sulfate films

The aim of this study was the preparation and characterization of hydrophobic–hydrophilic chitosan films obtained through interaction between the cationic biopolymer, chitosan (CH), with sodium lauryl ether sulfate (SLES), an anionic surfactant, which has also nonionic surfactant properties. The chitosan flat films were obtained at different concentrations of SLES, in the range of 0.02–0.1 M, where spherical capsules were also obtained. The wettability, quantified by the values of contact angle, indicated the hydrophobic character of the films. The significant values of swelling capacity in water, and in 1 % acetic acid solution confirmed the hydrophilic character of the obtained films. Weight loss of CH/SLES films after 24 h, in water and 1 % acetic acid solution was less than 3 % for the all samples. The structure of CH/SLES complex was determined by FTIR spectroscopy method. The morphology of CH/SLES film surfaces determined by atomic force microscopy showed a film surface with nanoroughness structure, determined by the SLES self-assembled nanostructures. The obtained CH/SLES films are transparent and have anti-fogging properties, compared with CH/sodium lauryl sulfate film, which is also transparent but, it gets fogged when coming in contact with warm air.     

Real time vision for intelligent vehicles

The authors first discuss the Intelligent StopandGo system, a sophisticated cruise control that autonomously follows a lead vehicle, pays attention to the relevant elements of the traffic infrastructure, and accounts for other traffic participants. The Intelligent StopandGo represents a multiyear effort by DaimlerChrysler to build a sophisticated cruise control that can function on highways, on secondary roads, and in urban environments. It combines the following capabilities: extracting lane boundaries, even when they are not clearly marked and do not contain the typical structure of highways; detecting a vehicle that can be followed, estimating ifs distance, speed, and acceleration; detecting stationary obstacles, such as parked cars, which limit the available free space; recognising the traffic signs and traffic lights that are relevant; and detecting and classifying additional traffic participants, such as pedestrians, who might cut in between the lead vehicle and the host vehicle. The DaimlerChrysIer demonstrator Urban Traffic Assistant (UTA) has devoted special attention to information, warning, and assistant functions in an inner-city environment. UTA is an E-class Mercedes-Bent containing sensors for longitudinal speed, longitudinal and lateral acceleration, yaw and pitch rate, and the sfeering wheel angle. It is equipped with a stereo black-and-white camera system as well as a color camera. UTA has access to throttle, brake, and steering. Furthermore, it displays the results of the perceptual modules in a graphical environment from either the driver's perspective or a virtual viewpoint. The computer hardware in UTA comprises three 400-MHz Linux/Pentium II (SMP) PCs for the perception of the environment and one Lynx/604e PowerPC for the control of sensors and actuators     

Propagation of material and surface profile uncertainties on MEMS micro‐resonators using a stochastic second‐order computational multi‐scale approach

This paper aims at accounting for the uncertainties because of material structure and surface topology of micro‐beams in a stochastic multi‐scale model. For micro‐resonators made of anisotropic polycrystalline materials, micro‐scale uncertainties exist because of the grain size, grain orientation, and the surface profile. First, micro‐scale realizations of stochastic volume elements are obtained based on experimental measurements. To account for the surface roughness, the stochastic volume elements are defined as a volume element having the same thickness as the microelectromechanical system (MEMS), with a view to the use of a plate model at the structural scale. The uncertainties are then propagated up to an intermediate scale, the meso‐scale, through a second‐order homogenization procedure. From the meso‐scale plate‐resultant material property realizations, a spatially correlated random field of the in‐plane, out‐of‐plane, and cross‐resultant material tensors can be characterized. Owing to this characterized random field, realizations of MEMS‐scale problems can be defined on a plate finite element model. Samples of the macro‐scale quantity of interest can then be computed by relying on a Monte Carlo simulation procedure. As a case study, the resonance frequency of MEMS micro‐beams is investigated for different uncertainty cases, such as grain‐preferred orientations and surface roughness effects. Copyright © 2016 John Wiley & Sons, Ltd.