Experimental evidence of the volume dependence of the deformational free energy of polymer networks

Summary Analysis of reported data on the swelling and deformation of polymer networks shows that the volume-dependent term in the deformational free energy cannot be neglected. The analysis is based on a comparison between the equilibrium modulof networks prepared at various dilutions and of the same degree of swelling and on a comparison between concentration dependences of the interaction parameter for a linear and a crosslinked polymer.     

1991 International Assessment of Educational Progress in Mathematics and Sciences: The gender differences perspective.

This study provides a global perspective on gender differences in performance of 9- and 13-year-olds on mathematics and science exams by reanalyzing and interpreting results on the 1991 International Assessment of Educational Progress. The analyses were performed across 20 countries that tested 13-year-olds and 14 countries that tested 9-year-olds. A random sample of 3,300 students was selected from each population at each age level; half were assessed in mathematics and half in science. The gender effect sizes on the mathematics assessment at both the subdomains level and the total scores were found to be small, especially among 9-year-olds. In general, the gender effects for science were substantially larger than those for mathematics (SD = 0.16 and 0.26 SDs on the total score, in favor of boys, for 9- and 13-year-olds, respectively). Analyses were carried out in seven selected countries—Hungary, Ireland, Israel, Korea, Scotland, Spain, and the United States. Gender differences in variability, reliability, and the structure of the intercorrelations among the subdomains were discussed as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of processing on the transverse fatigue properties of low-sulfur AISI 4140 steel

The effects of inclusions due to steelmaking processes on the fatigue life of AISI 4140 have been investigated. The test matrix consisted of three commercially produced heats of AISI 4140 of comparable cleanliness: one was conventionally cast (CC), and two were inert gas-shielded/ bottom-poured (IGS). One of the IGS heats was calcium-treated to explore the effects of inclusion shape control (IGS/SC). All heats were hot-rolled and reduced over 95 pct to produce bar stock of 127 to 152 mm (5 to 6 in.) in diameter. Transverse axial specimens conforming to ASTM E466 were machined, quenched, and tempered to approximately 40 HRC, and they were fatigue tested in tension-tension cycling (R = 0.1). Test results and statistical analyses of the stress-life data show that the IGS grade has several times the fatigue strength of the CC grade at 10⁷ cycles. Lower-limit fatigue strengths calculated at a 99.9 pct probability were 518.5 MPa (75.2 ksi) for IGSvs 55.6 MPa (8.1 ksi) for the CC grade. The IGS/SC grade had the best performance at all stress and life levels. The results obtained indicate that fatigue performance can be improved by choosing a processing method that reduces the incidence of exogenous oxides and by controlling the shape of the sulfides.     

Carbide Precipitation in Electrical Steels

This study determined the changes in core loss of a typical nonoriented silicon steel as a function of carbon saturation and aging temperature and time. The kinetics of carbide precipitation were investigated over the temperature range from 150 to 760°C and times from 30 sec. to 240 hrs. The changes in core loss were evaluated and correlated with morphology and distribution of carbide precipitates, using optical and electron microscopy. Once a transition carbide dispersion was initially established at a given aging temperature, particle coarsening and core loss changes were generally insensitive to aging time.     

Active synthesis using the DVCCS/DVCVS

In the paper basic properties of a new versatile linear active element acting simultaneously as a Differential Voltage Controlled Current Source (DVCCS) and Differential Voltage Controlled Voltage Source (DVCVS) are described. This element called a DVCCS/DVCVS can be used for generation of all linear nondynamic elements and also can be applied directly in active RC synthesis models. The general synthesis model with one DVCCS/DVCVS element and two particular synthesis models derived from the general one are described. All synthesis models presented here allow for cascading the second degree sections without additional buffers.     

Unobtrusive vehicle motion prediction cues reduced simulator sickness during passive travel in a driving simulator

This study investigated cues that permit prediction of turns during passive movement through a virtual environment. Effects on simulator sickness (SS), presence and enjoyment were examined. Subjects were exposed to complex visual motion through a cartoon-like simulated environment in a driving simulator. Forward velocity remained constant and the motion path was the same across all experimental conditions. Using a within-subject design, we examined visual paths that provided different levels of cue salience - detailed, simplified and no cues - for the upcoming simulated vehicle motion. Following each trial, participants completed questionnaires on SS, presence and enjoyment. After all of the trials were completed, a debriefing determined participants' perceptions of vehicle motion attributes and their awareness of the prediction cues. The results showed that SS in the no-cue condition was significantly greater than that in the conditions that provided vehicle motion cues. Presence and enjoyment responses were not different across the conditions. No participants reported differences between prediction cue conditions or recognized that the vehicle motion followed the same path across trials. However, participants tended to report that the motion was smoother for the detailed-cue than the no-cue condition. Participants ranked turn predictability as higher in conditions with prediction cues. The results support the hypothesis that unobtrusive and unreported motion cues may alleviate SS in a virtual environment.     

Space-time super-resolution

We propose a method for constructing a video sequence of high space-time resolution by combining information from multiple low-resolution video sequences of the same dynamic scene. Super-resolution is performed simultaneously in time and in space. By "temporal super-resolution," we mean recovering rapid dynamic events that occur faster than regular frame-rate. Such dynamic events are not visible (or else are observed incorrectly) in any of the input sequences, even if these are played in "slow-motion." The spatial and temporal dimensions are very different in nature, yet are interrelated. This leads to interesting visual trade-offs in time and space and to new video applications. These include: 1) treatment of spatial artifacts (e.g., motion-blur) by increasing the temporal resolution and 2) combination of input sequences of different space-time resolutions (e.g., NTSC, PAL, and even high quality still images) to generate a high quality video sequence. We further analyze and compare characteristics of temporal super-resolution to those of spatial super-resolution. These include: the video cameras needed to obtain increased resolution; the upper bound on resolution improvement via super-resolution; and, the temporal analogue to the spatial "ringing" effect.     

An application of a decision–theoretic model to a quota-free selection problem.

Demonstrated a possible application of a threshold utility model for evaluating the student selection procedure based on 1,554 applications made to the Faculty of Humanities at the Hebrew University of Jerusalem. Results show that the predictor was useful, unless its costs were very large. This conclusion is generalizable across the different definitions of success, since the utility ratios and the prior probabilities of success tended to neutralize one another. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)