Real-Time Camera Tracking for Mobile Devices: The VisiTrack System

This paper presents VisiTrack, a novel approach for video based incremental tracking in real-time. The major objectives in the development of VisiTrack was to design or select algorithms that are well suited for embedded real-time computation. We had a special focus on latency reduction and storage minimization since the algorithms should run on mobile devices like PDAs with the appropriate extension, i.e. mainly a camera, in real-time. The image analysis, camera localization and feature position approximation of VisiTrack are explained in detail. The CV-SDF model, an extension of Synchronous Dataflow graphs (SDF), supporting the principles of linear processing and fine-grained pipelining was defined and applied for the design of all VisiTrack modules in order to fulfill real-time constraints and reduce system latency. Furthermore the camera localization and position approximation include mechanisms for minimization of errors that may arise for instance due to measurement inaccuracies. Current applications of VisiTrack in the augmented reality domain and robotic self localization show its good performance. However VisiTrack is not limited to these application domains.     

Age discrimination in simulated employment contexts: An integrative analysis.

In the area of age discrimination in simulated employment settings, the present study meta-analytically tested 4 primary hypotheses derived from the social psychological stereotyping literature, referred to as the in-group bias, job information, salience, and job stereotype hypotheses. In general, the results supported the in-group bias, job information, and salience hypotheses, in that younger raters tended to give less favorable ratings to older workers when they were not provided with job-relevant information about the workers and when they concurrently rated old and young workers. Future research, including the initiation of research on economic-based age stereotypes, as well as practice directions related to valuing age diversity in organizational stakeholder groups are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Representations of self across the life span.

This research extends a cognitive-developmental approach to examining age differences in self-representation from adolescence to mature adulthood and later life. The authors suggest that mature adults move from representations of self that are relatively poorly differentiated from others or social conventions to ones that involve emphasis on process, context, and individuality. Participants (n men?=?73, n women?=?76), ranging in age from 11 to 85 years, provided spontaneous accounts of their self-representations and responded to measures assessing cognitive and emotional functioning and broad dimensions of personality. On average, self-representation scores peaked in middle-aged adults and were lowest in the preadolescent and older adult age groups. Level of self-representation was related to cognitive and personality variables, but there was some evidence that the pattern of correlates shifted from younger (ages 15–45) to older (ages 46–85) age segments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of selected process variables on the elimination of cyanide from cassava

The effects of selected methods of size reduction, holding periods and drying on elimination of cyanide from cassava roots of variety MCol 1684 were investigated. Drying at 50°C eliminated approximately 50% of the total cyanide from mechanically prepared chips, and 25% from manually prepared chips. Mechanical chipping and drying at 50°C eliminated 65% of the total cyanide from small chips and 47% from large chips. Mincing of whole roots completely degraded the glucoside, and rasping and mechanical chipping degraded 70–80% and 30% of the initial glucoside respectively. The results indicate that the method of size reduction and particle size control the rate of glucoside degradation, and that the drying rate limits the quantity of glucosidic cyanide eliminated. The results are compared with those of other researchers.     

Coulomb Enhanced Charge Transport in Semicrystalline Polymer Semiconductors

Polymer semiconductors provide unique possibilities and flexibility in tailoring their optoelectronic properties to match specific application demands. The recent development of semicrystalline polymers with strongly improved charge transport properties forces a review of the current understanding of the charge transport mechanisms and how they relate to the polymer's chemical and structural properties. Here, the charge density dependence of field effect mobility in semicrystalline polymer semiconductors is studied. A simultaneous increase in mobility and its charge density dependence, directly correlated to the increase in average crystallite size of the polymer film, is observed. Further evidence from charge accumulation spectroscopy shows that charges accumulate in the crystalline regions of the polymer film and that the increase in crystallite size affects the average electronic orbitals delocalization. These results clearly point to an effect that is not caused by energetic disorder. It is instead shown that the inclusion of short range coulomb repulsion between charge carriers on nanoscale crystalline domains allows describing the observed mobility dependence in agreement with the structural and optical characterization. The conclusions that are extracted extend beyond pure transistor characterization and can provide new insights into charge carrier transport for regimes and timescales that are relevant to other optoelectronic devices.     

Flexible and Ultrasoft Inorganic 1D Semiconductor and Heterostructure Systems Based on SnIP

Low dimensionality and high flexibility are key demands for flexible electronic semiconductor devices. SnIP, the first atomic‐scale double helical semiconductor combines structural anisotropy and robustness with exceptional electronic properties. The benefit of the double helix, combined with a diverse structure on the nanoscale, ranging from strong covalent bonding to weak van der Waals interactions, and the large structure and property anisotropy offer substantial potential for applications in energy conversion and water splitting. It represents the next logical step in downscaling the inorganic semiconductors from classical 3D systems, via 2D semiconductors like MXenes or transition metal dichalcogenides, to the first downsizeable, polymer‐like atomic‐scale 1D semiconductor SnIP. SnIP shows intriguing mechanical properties featuring a bulk modulus three times lower than any IV, III‐V, or II‐VI semiconductor. In situ bending tests substantiate that pure SnIP fibers can be bent without an effect on their bonding properties. Organic and inorganic hybrids are prepared illustrating that SnIP is a candidate to fabricate flexible 1D composites for energy conversion and water splitting applications. SnIP@C₃N₄ hybrid forms an unusual soft material core–shell topology with graphenic carbon nitride wrapping around SnIP. A 1D van der Waals heterostructure is formed capable of performing effective water splitting.     

Investigation of Thermal Stability and Degradation Mechanisms in Ni-Based Ohmic Contacts to <Emphasis Type="Italic">n</Emphasis>-Type SiC for High-Temperature Gas Sensors

We investigated the thermal stability of Pt/TaSi _x /Ni/SiC ohmic contacts, which have been implemented in SiC-based gas sensors developed for applications in diesel engines and power plants. The contacts remained ohmic on lightly doped n-type (~1 × 10¹⁶ cm⁻³) 4H-SiC for over 1000 h in air at 300°C. Although a gradual increase in specific contact resistance from 3.4 × 10⁻⁴ Ω cm² to 2.80 × 10⁻³ Ω cm² was observed, the values appeared to stabilize after ~800 h of heating in air at 300°C. The contacts heated at 500°C and 600°C, however, showed larger increases in specific contact resistance followed by nonohmic behavior after 240 h and 36 h, respectively. Concentration profiles from Auger electron spectroscopy and electron energy-loss spectroscopy show that loss of ohmic behavior occurs when the entire tantalum silicide layer has oxidized.     

Process Improvement: Reengineering Spacelab Mission Requirements Flow

ABSTRACT

An example of process improvement at the Marshall Space Flight Center is presented. The objective of this activity was to increase efficiency in the Spacelab mission requirements flow, which is the process that manages change requests from mission customers. The team formed to review the existing process used a systems engineering approach and Deming's plan, do, study, act cycle. The goal of the analysis was to eliminate rework and duplication, minimize the time that change requests spend in the system, and standardize procedures. After implementing the team's recommendations, average processing time was reduced by more than 60%.     

Kalman filtering to suppress spurious signals in adaptive optics control

In many scenarios, an adaptive optics (AO) control system operates in the presence of temporally non-white noise. We use a Kalman filter with a state space formulation that allows suppression of this colored noise, hence improving residual error over the case where the noise is assumed to be white. We demonstrate the effectiveness of this new filter in the case of the estimated Gemini Planet Imager tip-tilt environment, where there are both common-path and non-common-path vibrations. We discuss how this same framework can also be used to suppress spatial aliasing during predictive wavefront control assuming frozen flow in a low-order AO system without a spatially filtered wavefront sensor, and present experimental measurements from Altair that clearly reveal these aliased components.     

Microscale wear behavior and crosslinking of PEG-like coatings for total hip replacements

The predominant cause of late-state failure of total hip replacements is wear-mediated osteolysis caused by wear particles that originate from the ultrahigh molecular weight polyethylene (UHMWPE) acetabular cup surface. One strategy for reducing wear particle formation from UHMWPE is to modify the surface with a hydrophilic coating to increase lubrication from synovial fluid. This study focuses on the wear behavior of hydrophilic coatings similar to poly(ethylene glycol) (PEG). The coatings were produced by plasma-polymerizing tetraglyme on UHMWPE in a chamber heated to 40°C or 50°C. Both temperatures yielded coatings with PEG-like chemistry and increased hydrophilicity relative to uncoated UHMWPE; however, the 40°C coatings were significantly more resistant to damage induced by atomic force microscopy nanoscratching. The 40°C coatings exhibited only one damage mode (delamination) and often showed no signs of damage after repeated scratching. In contrast, the 50°C coatings exhibited three damage modes (roughening, thinning, and delamination), and always showed visible signs of damage after no more than two scratches. The greater wear resistance of the 40°C coatings could not be explained by coating chemistry or hydrophilicity, but it corresponded to an approximately 26–32% greater degree of crosslinking relative to the 50°C surfaces, suggesting that crosslinking should be a significant design consideration for hydrophilic coatings used for total hip replacements and other wear-dependent applications.