Les études d’usages : entre normalisation et rhétorique

The usability studies trend is now widely recognized as useful in the industry, although not always reliable. Usability must complain with a realistic constraint as well as with a formalist one, but nevertheless succeeds in being considered as users ’ spokesman through a normalization process. By doing this, it makes acceptable a number of conceptual reductions, that should be challenged by academic research, regarding the categories used to think the users, the contexts or the uses goals. Finally, the trust in usability experts services relies more in their ability to convince industrials and developers. This requires good quality products, the very products of ergonomist activity : report, presentation, recommandations, and so on, which are the only way for their arguments to survive in the development process.     

Large time behavior for discrete models in age-dependent SIS epidemics

A stabilization result is proved for two discrete age dependent SIS epidemic models (intercohort and intracohort transmission are both studied). Their dynamics depend on a threshold parameter and also on the fertility of the initial condition. Received: February 1995 / Revised version: August 1996     

New fluorinated polysiloxanes containing an ester function in the spacer—II. Surface tension studies

The surface tensions of fluorinated polysiloxanes prepared by hydrosilylation of unsaturated perfluoroalkyl esters derived from undecylenic acid [CH₂?CH? (CH₂)₈? COO? CH₂? CH₂? R_F, with R_F = C₆F₁₃, C₈F₁₇, and C₈F₁₇? (CH₂)₁₀COO? CH₂? CH₂? CH?CH₂] by methylhydrodimethylsiloxane copolymers of various Si? H contents have been measured. The critical surface tensions, γ_c, and the solid surface tensions, γ^D_s, were deduced from n-alkane and water contact angle data. They decrease as the perfluoroalkyl graft content of the copolymers increases. Some of them, which are in the range of the lowest surface tension fluoro polymers known, are observed when the fluorinated segments are self-organized at the interface, i.e. when the polymers are mesomorphous or crystalline at room temperature.     

Initiation à la conception de circuits à la demande avec Solo 2000

The pedagogical product presented in this paper is a practical work for initiation to computer aided design environment for full-customVLSI circuits, specifically the Solo 2000CAD design environment. Students of “MST architecture de machines informatiques”,“DESS microélectronique”, or “maîtrise d’informatique” follow this initiation. This practical work being a lecture support, students have the sufficientVLSI design knowlegde for its realisation. Through the same example from electrical schematic capture to layout, the students go over the different methodology steps with aCAD environment such as Solo 2000. Starting with a general presentation ofCAD tools, the practical work is divided into a 6 step approach. The required time for this initiation is about 15 to 18 hours, per session of 3 hours. This formation is done in theCCMO lecture room fitted out with 6 SUN3 workstations, each running a Solo 2000 licence (received fromCNFM). In this lecture room, groups of 12 students can follow the initiation toCAD environment for full customVLSI circuits.     

Improving the Durability of a Biomedical-Grade Zirconia Ceramic by the Addition of Silica

The lifetime of tetragonal zirconia ceramic implants is controlled by their resistance to slow crack growth and low-temperature degradation (LTD). A decrease of the grain size is often proposed to decrease the effect of LTD on zirconia; however, this decrease also reduces the resistance to crack propagation. An alternative approach is reported here; such an approach consists of introducing a silica glass phase only at triple grain junctions, without changing the grain size. The addition of a small amount of silica (0.5 wt%) decreases the internal stresses, which improves the resistance to LTD without affecting the resistance to crack propagation. These results are discussed from a microstructural standpoint.     

Interfacial transfer between copper and polyurethane in chemical-mechanical polishing

The interactions between a copper and urethane polishing pads were characterized to investigate the effects of friction on removal mechanisms of a polishing system of copper interconnect wafers in water. In-situ characterization of polished copper and urethane were conducted using Auger and x-ray photoelectron spectroscopy (XPS) analysis techniques. These techniques pinpointed the chemical interactions immediately during polishing. Results indicated that, because of the stimulation of friction, the molecules from the pad transferred to the copper surface, and the oxidized copper surface was transferred to the urethane surface. Without friction, however, such a transformation did not occur and passivation of the copper surface took place. This evidence proves a possible new chemical-mechanical polishing (CMP) mechanism. In addition to the formation and removal of a passivation layer, a transformation layer is formed during CMP because of friction stimulation. This layer is found on both copper and pad surfaces with different chemical bonds. Understanding the transformation layer helps to understand the formation of defects, pad conditioning, and pad life.     

Stability of attachment representations: The transition to marriage.

This study examined the stability of adult attachment representations across the transition to marriage. One hundred fifty-seven couples were assessed using the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1985), the Current Relationship Interview (J. A. Crowell & G. Owens, 1996), and measures describing relationship functioning and life events 3 months prior to their weddings and 18 months into their marriages. The authors tested the hypotheses that attachment classifications are stable and that change is related to experiences in the relationship and/or life events; 78% of the sample received the same primary AAI classification (secure, preoccupied, and dismissing) at both times. Change was toward increased security and was associated with feelings and cognitions about the relationship. Only 46% of participants initially classified as unresolved retained the classification. Stability of the unresolved classification was associated with stressful life events and relationship aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure to Condensation Moisture of Sheathing in Retrofitted Leaky Wall Assemblies

Exfiltration of moist indoor air during winter conditions may lead to the gradual wetting of the sheathing of wall assemblies that are not airtight. In this study, seven full-scale wood-frame wall specimens were tested to evaluate the impact of both the geometry of the air leakage path and the addition of rigid insulation on the warm side or the cold side of the assembly on the hygrothermal response of wall assemblies. Walls were exposed to 72?days of steady-state winter conditions and 47?days of steady-state late spring conditions. The position of the added rigid insulation and the geometry of the air leakage paths were different in each wall specimen. The moisture content of the fiberboard sheathing was monitored, and the results are presented. The evolution over time of the moisture distribution across the plane of the sheathing is also presented. The duration of exposure to moisture content above 19 and 28% is examined, allowing a comparison of the performance of the specimens. Leaky assemblies with vapor-tight insulation board added on their cold side were exposed to high moisture content longer than the assemblies not reinsulated or reinsulated on their warm side because the assemblies without insulation on the cold side of the sheathing were exposed to a buildup of frost that prevented moisture to be absorbed by the sheathing.     

Effects of Task Relevance and Stimulus-Driven Salience in Feature-Search Mode.

Attentional allocation in feature-search mode (W. F. Bacon & H. E. Egeth, 1994) is thought to be solely determined by top-down factors, with no role for stimulus-driven salience. The authors reassessed this conclusion using variants of the spatial cuing and rapid serial visual presentation paradigms developed by C. L. Folk and colleagues (C. L. Folk, R. W. Remington, & J. C. Johnston, 1992; C. L. Folk, A. B. Leber, & H. E. Egeth, 2002). They found that (a) a nonsingleton distractor that possesses the target feature produces attentional capture, (b) such capture is modulated by bottom-up salience, and (c) resistance to capture by irrelevant singletons is mediated by inhibitory processes. These results extend the role of top-down factors in search for a nonsingleton target while arguing against the notion that effects of bottom-up salience and top-down factors on attentional priority are strictly encapsulated within distinct search modes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)