Pore Propagation Directions in P+ Porous Silicon

A comparative study is presented on the pore propagation directions of porous silicon layers (PSL) formed on p⁺-type substrates of different orientations. PSLs were formed on plain (0 0 1) and (1 1 1) silicon wafers as well as on structured (0 0 1) wafers containing facets of various orientations. During anodization, regular pores follow the 0 0 1 direction on the (0 0 1) planes. While on the (1 1 1) planes fewer regular pores develop and seemingly propagate closely to the 1 1 1 direction. These results indicate that the pores propagate perpendicular to the surface i.e. along the field lines when the surface orientation is either (0 0 1) or (1 1 1).When the silicon surface provided (1 1 0) orientation (Chuang, Collins, and Smith, 1989), or its position is in between the (0 0 1) and (1 1 1) planes then the pores do not propagate perpendicular to the surface but along the 0 0 1 direction.All the phenomena exhibited might be explained by presuming that during formation, the pores propagate along the 1 0 0 directions, and that those 1 0 0 directions are preferred which are closely to the field lines. In PSLs formed on (0 0 1) surfaces the field lines and the 0 0 1 crystallographic direction are coincident. However, in the (1 1 1) oriented wafer where three equally probable 1 0 0 directions exist around the field lines, more irregular structure of PSLs will develop.     

Coarse-Grain Coherence Tracking: RegionScout and Region Coherence Arrays

Coarse-grain coherence tracking is a new technique that extends a conventional coherence mechanism and optimizes coherence enforcement. It monitors the coherence status of large regions of memory and uses that information to avoid unnecessary broadcasts and filter unnecessary cache tag lookups, thus improving system performance and power consumption.     

Reliability study of TaON capacitors: From leakage current characterization to ESD robustness prediction

Electrostatic discharges are a permanent threaten for integrated metal–insulator–metal capacitors. Hence, the development of comprehensive models able to predict the capacitors robustness against ESD aggression is of major importance to adopt the adequate protection strategies. This work focuses more particularly on the failure mechanisms of TaON capacitors submitted to HBM ESD waves. From leakage current characterization to thermal dissipation effects, we propose a complete reliability model which accurately foresees not only ESD failure voltage, but also TDDB capacitors lifetime.     

L'échelle de développement pubertaire: équivalence en langue fran?aise du <>.

The Pubertal Development Scale from A. C. Petersen and L. J. Crockett (1985) is a self-report instrument that measures levels of pubertal maturation in adolescence. The main goal of this study was to validate the French version of the instrument on a high school population. The latter was administered on 3 occasions to 255 students during their 1st and 2nd high school years. The measure's internal consistency and the sequence of bodily changes of boys and girls allowed the authors to establish the reliability of the students' perception of their pubertal development. Like J. M. Tanner (1962) and Petersen et al. (1985, 1988), 5 categories identifying different pubertal status were labeled. Results show satisfactory reliability from such a pubertal classification system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual map‐less navigation based on homographies

We introduce a method for autonomous robot navigation based on homographies computed between the current image and images taken in a previous teaching phase with a monocular vision system. The features used to estimate the homography are vertical lines automatically extracted and matched. From homography, the underlying motion correction between the reference path and the current robot location is computed. The proposed method, which uses a sole calibration parameter, has turned out to be especially useful to correct heading and lateral displacement, which are critical in systems based on odometry. We have tested the proposal in simulation, and with real images. Besides, the visual system has been integrated into an autonomous wheelchair for handicapped, working in real time with robustness. © 2005 Wiley Periodicals, Inc.     

Development of a multitechnology field-programmable gate array suitable for photonic information processing

The architecture of a novel, multitechnology field-programmable gate array (FPGA) is introduced. Based on conventional complementary metal-oxide semiconductor VLSI technology this architecture has demonstrated the feasibility of reconfigurable and programmable hardware for prototyping photonic information processing systems. We report that this new FPGA architecture will enable the design of reconfigurable systems that incorporated technologies outside the traditional electronic domain. The smart photoreceivers monolithically integrated in the new FPGA architecture can receive optically encoded signals in parallel and process them with user programmable logic hardware.