Cooperative learning strategies for intelligent tutoring systems

Intelligent tutoring systems (ITS) are evolving towards a more cooperative relationship between the system and the student. More and more, learning is considered as a constructive process rather than a simple transfer of knowledge. This trend has brought to light new cooperative tutoring strategies. One of these tutoring strategies, the learning companion, designed to overcome some of the limitations of the classical tutoring model, involves a student and two simulated participants: a tutor and another student. More recently, a new strategy, learning by disturbing, has been proposed. In this strategy, the simulated student is a troublemaker whose role is to deliberately disturb the human student. This article describes the learning by disturbing strategy by contrasting it with the learning companion strategy. In addition, links are drawn between this new strategy and the psychology of learning, in particular the cognitive dissonance theory. An indicator has been developed that measures discord between the ideas, helping to pinpoint the concepts that are most likely to be misunderstood by the learner. Doing so allows one to plan more efficiently the interventions of the troublemaker.     

Activity recognition using eye-gaze movements and traditional interactions

The need for intelligent HCI has been reinforced by the increasing numbers of human-centered applications in our daily life. However, in order to respond adequately, intelligent applications must first interpret users’ actions. Identifying the context in which users’ interactions occur is an important step toward automatic interpretation of behavior. In order to address a part of this context-sensing problem, we propose a generic and application-independent framework for activity recognition of users interacting with a computer interface. Our approach uses Layered Hidden Markov Models (LHMM) and is based on eye-gaze movements along with keyboard and mouse interactions. The main contribution of the proposed framework is the ability to relate users’ interactions to a task model in variant applications and for different monitoring purposes. Experimental results from two user studies show that our activity recognition technique is able to achieve good predictive accuracy with a relatively small amount of training data.     

Developing a hybrid, carbon/glass fiber-reinforced, epoxy composite automotive drive shaft

In this study, a finite element analysis was used to design composite drive shafts incorporating carbon and glass fibers within an epoxy matrix. A configuration of one layer of carbon–epoxy and three layers of glass–epoxy with 0°, 45° and 90° was used. The developed layers of structure consists of four layers stacked as [+45_glass°/-45_glass°/0_carbon°/90_glass°]. The results show that, in changing carbon fibers winding angle from 0° to 90°, the loss in the natural frequency of the shaft is 44.5%, while, shifting from the best to the worst stacking sequence, the drive shaft causes a loss of 46.07% in its buckling strength, which represents the major concern over shear strength in drive shaft design.     

Preservative Effect on Stress-Laminated Southern Pine Bridge Decks

Stress-laminated timber bridge decks have gained increasing popularity in the United States in recent years. As with all wood exposed to the environment, wood for these decks must be treated with preservatives. There has been reluctance to build chromated-copper-arsenate (CCA) –treated wood bridges due to concerns about dimensional stability. Because no research has been undertaken to investigate the use of CCA-treated southern pine in stress-laminated bridge decks, a good resource for economic rural bridges has remained untapped. The objective of this study was to evaluate the performance of various wood preservatives on stress-laminated southern pine bridge decks. A total of nine decks with seven different preservatives were built and exposed to the environment for more than 2 years. Force levels in prestressing bars and wood moisture contents from each deck were continuously monitored. It was found that the short-term variations in the bar stress levels are less for decks with oil-type preservatives, as compared to CCA preservatives. The long-term performance for decks with both preservative types was found to be similar. The anchorage effect on the deck performance was found to be negligible.     

Investigation of the effect of charge transfer coefficient (CTC) on the operating voltage of polymer electrolyte membrane (PEM) electrolyzer

Activation overpotential is a very important parameter in evaluating the performance of PEM electrolyzer, it is one of the major overpotentials that contribute towards overall operating voltage of the electrolyzer. One of the most significant parameters associated with this overvoltage is charge transfer coefficient (CTC). This study aims to contribute to this growing area of research by investigating the effects of operating temperature and CTC on the overall operating voltage. This study also provides an important opportunity to advance the understanding of the effect of different temperature and pressure on the CTC. The result of this study was successfully compared with experimental data. The simulation result shows that, within the temperature range of 10 °C–90 °C, the CTC values at the anode electrode ranges between 0.807 and 1.035 while at the cathode electrode, the variation is only within 0.202–0.259. It was observed that activation overvoltage decreases when the CTC increase from 0.1 to 2.0 both at anode and cathode electrodes. Interestingly it was observed that the CTC remains the same even at balanced and unbalanced pressure.     

Current trends of tropical fruit waste utilization

Recent rapid growth of the world's population has increased food demands. This phenomenon poses a great challenge for food manufacturers in maximizing the existing food or plant resources. Nowadays, the recovery of health benefit bioactive compounds from fruit wastes is a research trend not only to help minimize the waste burden, but also to meet the intensive demand from the public for phenolic compounds which are believed to have protective effects against chronic diseases. This review is focused on polyphenolic compounds recovery from tropical fruit wastes and its current trend of utilization. The tropical fruit wastes include in discussion are durian (Durio zibethinus), mangosteen (Garcinia mangostana L.), rambutan (Nephelium lappaceum), mango (Mangifera indica L.), jackfruit (Artocarpus heterophyllus), papaya (Carica papaya), passion fruit (Passiflora edulis), dragon fruit (Hylocereus spp), and pineapple (Ananas comosus). Highlights of bioactive compounds in different parts of a tropical fruit are targeted primarily for food industries as pragmatic references to create novel innovative health enhancement food products. This information is intended to inspire further research ideas in areas that are still under-explored and for food processing manufacturers who would like to minimize wastes as the norm of present day industry (design) objective.