Autochthony through self-organization: Interactivism and emergence in a virtual environment

In this paper we take an interactivist perspective on the computer-mediated classroom, and explore the autopoietic teaching approach in the context of emergence of diversity in the classroom. The POPSICLE (Patterns in Orientation: Pattern-Aided Simulated Interaction Context-Learning Experiment) is presented and discussed, as well as its multiple consequences. POPSICLE is a study of learning in human subjects, as well as of interaction and transfer of knowledge between subjects in a collaborative environment.     

Tailoring the crack-tip microstructure: a novel approach

This investigation demonstrates a way to innovatively modify the ferritic microstructure at a local scale, particularly at the failure prone area such as Charpy V-notch (CVN) root. Tensile pre-strain (PS) up to 6% and 12% were employed before annealing (An) the samples at 650°C for 15?minutes. Ferrite grain size increased sharply and gradually (along the distance ahead of the notch root) within the microstructurally modified region in 6–12% pre-strained and annealed samples, respectively. The critical strain which promotes strain-induced boundary migration (SIBM), was found to be 0.1 which resulted in abnormally coarse ferrite grains.     

Evidence for the external validity of a social simulation measure of social skills

Two studies were conducted in order to obtain evidence regarding the external validity of a social simulation measure of social skills. The first study employed a contrasted group design, with the groups consisting of National Guardsmen and psychiatric patients. As predicted, trained judges rated the performances of the National Guardsmen in the simulations as more skillful and appearing less anxious than the psychiatric patients. In the second study, trained judges' ratings of psychiatric patients' performances in the simulations were found to be significantly related to ratings made by interviewers who had conducted a structured social history interview with the patients, nurses' ratings based on their observations of patients after 3 days on the psychiatric unit, a research assistant's ratings based on contact with the patient during the experiment, and finally, the subject's own self-ratings. In discussing the findings, it is hypothesized that one reason why support was found for the external validity of the simulation strategy in this study, in contrast to some previously reported studies, was the use of molar ratings in this study as opposed to the more molecular rating procedures used in those previous studies.These studies were funded in part by a research grant from the Veterans Administration.     

A simulated annealing methodology for clusterwise linear regression

In many regression applications, users are often faced with difficulties due to nonlinear relationships, heterogeneous subjects, or time series which are best represented by splines. In such applications, two or more regression functions are often necessary to best summarize the underlying structure of the data. Unfortunately, in most cases, it is not known a priori which subset of observations should be approximated with which specific regression function. This paper presents a methodology which simultaneously clusters observations into a preset number of groups and estimates the corresponding regression functions' coefficients, all to optimize a common objective function. We describe the problem and discuss related procedures. A new simulated annealing-based methodology is described as well as program options to accommodate overlapping or nonoverlapping clustering, replications per subject, univariate or multivariate dependent variables, and constraints imposed on cluster membership. Extensive Monte Carlo analyses are reported which investigate the overall performance of the methodology. A consumer psychology application is provided concerning a conjoint analysis investigation of consumer satisfaction determinants. Finally, other applications and extensions of the methodology are discussed.     

Measured increases in steering entropy may predict when performance will degrade: A driving simulator study

We investigated the effect of time-on-task on driver’s mental workload and driving performance during a simulated driving task. The extent of mental workload was estimated from steering entropy, while driver performance was measured from the Standard Deviation of Lateral Position (SDLP) and the Standard Deviation (SD) Sterring Angle. Seventeen participants underwent a simulated highway driving task for 60 min. The results show that mental workload increased significantly after 15 min, whereas driving performance did not degrade until 30 min. These results suggest that when drivers first affected by time-on-task, they can cope with the situation by increasing mental effort investment and can manage to perform normally for a while (15 min). Since changes in steering entropy precede changes in driving performance, this measure of mental workload may have utility as a predictor of increased accident risk.     

Post-irradiation annealing behaviour of oxide dispersion strengthened Fe-Cr alloys studied by nanoindentation

ABSTRACT

To study the nature of irradiation-induced nanofeatures in oxide dispersion strengthened (ODS) Fe-Cr alloys, post-irradiation isochronal thermal annealing up to 600°C was performed for ODS Fe-9%Cr and Fe-14%Cr alloys ion-irradiated at 300°C and 500°C. Nanoindentation indicated hardening for all as-irradiated alloys and complete hardness recovery upon post-irradiation annealing. Cross-sectional TEM indicated an irradiation-induced defect band near peak damage mainly consisting of dislocation loops. Candidate mechanisms of recovery were critically evaluated. Shrinkage of loops via capture of thermal vacancies was found to correctly reflect the annealing behaviour of ODS Fe-9Cr irradiated at 300°C.     

Effect of heat treatment on the NO2-sensing properties of sputter-deposited indium tin oxide thin films

Transparent conducting indium tin oxide (ITO) films were deposited onto glass substrates by radio-frequency magnetron sputtering at 648?K, under an oxygen partial pressure of 1?Pa. The effect of annealing on the electrical properties of the films was studied. Characterization of the coatings revealed an electrical resistivity below 6.5?×?10^??3?Ω?cm. The ITO films deposited at 648?K were amorphous, while the crystallinity improved after annealing at 700?K. The surface morphology examined by scanning electron microscopy appears to be uniform over the entire surface area after annealing. The NO₂-sensing properties of the ITO films were investigated and showed sensitivity at concentrations lower than 50?ppm, at a working temperature of 600?K.     

The inherent tensile strength of iron

The cohesive energy of Fe as a function of structure, strain and magnetic state has been computed using the full potential linearized augmented-plane-wave method within the framework of density functional theory and the generalized gradient approximation. Calculations corresponding to uniaxial stress in the <100> direction reveal that the ideal tensile strength of bcc Fe is about 14.2GPa and is determined by instability with respect to transformation into an unstable ferromagnetic fcc structure. The low-energy fcc phase is a modulatedantiferromagnetic fcc structure that is connected to the bcc phase via a first-order magnetic transformation and does not compromise its ideal strength.     

The effects of music tempo on simulated driving performance and vehicular control

The automobile is currently the most popular and frequently reported location for listening to music. Yet, not much is known about the effects of music on driving performance, and only a handful of studies report that music-evoked arousal generated by loudness decreases automotive performance. Nevertheless, music tempo increases driving risks by competing for attentional space; the greater number of temporal events which must be processed, and the frequency of temporal changes which require larger memory storage, distract operations and optimal driving capacities. The current study explored the effects of music tempo on PC-controlled simulated driving. It was hypothesized that simulated driving while listening to fast-paced music would increase heart rate (HR), decrease simulated lap time, and increase virtual traffic violations. The study found that music tempo consistently affected both simulated driving speed and perceived speed estimates: as the tempo of background music increased, so too did simulated driving speed and speed estimate. Further, the tempo of background music consistently affected the frequency of virtual traffic violations: disregarded red traffic-lights (RLs), lane crossings (LNs), and collisions (ACs) were most frequent with fast-paced music. The number of music-related automobile accidents and fatalities is not a known statistic. Police investigators, drivers, and traffic researchers themselves are not mindful of the risks associated with listening to music while driving. Implications of the study point to a need for drivers' education courses to raise public awareness about the effects of music during driving.     

A differentiating empirical linguistic analysis of dreamer activity in reports of EEG-controlled REM-dreams and hypnagogic hallucinations

We present Activity Analysis as a new method for the quantification of subjective reports of altered states of consciousness with regard to the indicated level of simulated motor activity. Empirical linguistic activity analysis was conducted with dream reports conceived immediately after EEG-controlled periods of hypnagogic hallucinations and REM-sleep in the sleep laboratory. Reports of REM-dreams exhibited a significantly higher level of simulated physical dreamer activity, while hypnagogic hallucinations appear to be experienced mostly from the point of passive observer. This study lays the groundwork for clinical research on the level of simulated activity in pathologically altered states of subjective experience, for example in the REM-dreams of clinically depressed patients, or in intrusions and dreams of patients diagnosed with PTSD.