The influence of virtual presence: Effects on experienced cognitive load and learning outcomes in educational computer games

Does the immersive design of an educational gaming environment affect learners’ virtual presence and how much do they learn? Does virtual presence affect learning? This study tries to answer these questions by examining the differences in virtual presence and learning outcomes in two different computer-based multimedia environments: a gaming environment with high immersive design vs. hypertext learning environment with low immersive design. As the main focus, the effect of virtual presence on learning is also explained and tested. By identifying virtual presence as a variable that may determine learning, it is argued that computer gaming environments present a new challenge for researchers to investigate, particularly, the effects of virtual presence on the immersive design of games in order to help designers to predict which instructional configurations will maximize learning performance. In general, results revealed that the high-immersive gaming environment leads to the strongest form of virtual presence but also decreased learning. Although regression analyses indicate that virtual presence positively influences trivial- and non-trivial learning outcomes, learners who learned in a low-immersive environment outperformed the gaming group. A mediation analysis showed that the relation between virtual presence and non-trivial learning outcomes is partly mediated through increased cognitive load.     

Multilingual resources for NLP in the lexical markup framework (LMF)

Optimizing the production, maintenance and extension of lexical resources is one the crucial aspects impacting natural language processing (NLP). A second aspect involves optimizing the process leading to their integration in applications. With this respect, we believe that a consensual specification on monolingual, bilingual and multilingual lexicons can be a useful aid for the various NLP actors. Within ISO, one purpose of Lexical Markup Framework (LMF, ISO-24613) is to define a standard for lexicons that covers multilingual lexical data.

Analyzing visually impaired people’s touch gestures on smartphones

Multimedia Tools and Applications - We present an analysis of how visually impaired people perform gestures on touch-screen smartphones and report their preferences, explaining the procedure and...     

Design and control of an IPMC wormlike robot.

This paper presents an innovative wormlike robot controlled by cellular neural networks (CNNs) and made of an ionic polymer-metal composite (IPMC) self-actuated skeleton. The IPMC actuators, from which it is made of, are new materials that behave similarly to biological muscles. The idea that inspired the work is the possibility of using IPMCs to design autonomous moving structures. CNNs have already demonstrated their powerfulness as new structures for bio-inspired locomotion generation and control. The control scheme for the proposed IPMC moving structure is based on CNNs. The wormlike robot is totally made of IPMCs, and each actuator has to carry its own weight. All the actuators are connected together without using any other additional part, thereby constituting the robot structure itself. Worm locomotion is performed by bending the actuators sequentially from "tail" to "head," imitating the traveling wave observed in real-world undulatory locomotion. The activation signals are generated by a CNN. In the authors' opinion, the proposed strategy represents a promising solution in the field of autonomous and light structures that are capable of reconfiguring and moving in line with spatial-temporal dynamics generated by CNNs.     

Luminescent Eu(III) hybrid sensors for in situ copper detection

In this work we used the sol-gel technique to develop luminescent Eu(III) transparent films deposited on glass slides to build for sensor devices capable of monitoring transition metal ions in aqueous solutions. The films were obtained from a bis(trialkoxysilyl) organic precursor synthesized from the amide of the 2,6-pyridinedicarboxylic acid (DPA) with aminopropyltriethoxysilane (APTES) in the presence or absence of cetyl trimethyl ammonium bromide (CTAB) surfactant as templating agent and triethylethoxysilane (TEOS) as crosslinker. These sensor devices were used to perform in situ quenching experiments by Cu(II), Fe(III), Co(II) and Ni(II) ions. The results indicate that the templated films allow the detection and quantification of these metals down to ppb levels by means of the values of the Stern-Volmer constants. In particular, it was shown that Cu(II) acts as an extremely efficient quencher (K_SV = 3.5 × 10⁵ M⁻¹) when compared with the results obtained for the other metals, opening the possibility to use these devices as potential Cu(II) sensors for actual applications in aqueous media.     

Low Power Encoding Techniques for Dynamically Reconfigurable Hardware

In this paper, an approach to the implementation of digital systems is presented which utilizes dynamic hardware reconfiguration in order to automatically minimize the power dissipated on module interconnections such as system buses during system run time. Reduction of power dissipation is achieved by means of an activity-reducing system bus encoding technique. Encoder and decoder are implemented with dynamically reconfigured code tables which contain a transition minimizing code that is periodically recomputed during run time of the system in order to adapt to variations in the statistical parameters of the encoded data stream. We present the theoretical basics and an efficient implementation of a corresponding coder-decoder system. Experimental results showed a reduction in bus transition activity of up to 41%.     

A Graph Abstract Machine Describing Event Structure Composition

Event structures, Game Semantics strategies and Linear Logic proof-nets arise in different domains (concurrency, semantics, proof-theory) but can all be described by means of directed acyclic graphs (dag's). They are all equipped with a specific notion of composition, interaction or normalization.We report on-going work, aiming to investigate the common dynamics which seems to underly these different structures.In this paper we focus on confusion free event structures on one side, and linear strategies [Jean-Yves Girard. Locus solum. Mathematical Structures in Computer Science, 11:301–506, 2001, C. Faggian and F. Maurel. Ludics nets, a game model of concurrent interaction. In Proc. of LICS'05 (Logic in Computer Science). IEEE Computer Society Press, 2005] on the other side. We introduce an abstract machine which is based on (and generalizes) strategies interaction; it processes labelled dag's, and provides a common presentation of the composition at work in these different settings.     

Practical voting rules with partial information

Voting is an essential mechanism that allows multiple agents to reach a joint decision. The joint decision, representing a function over the preferences of all agents, is the winner among all possible (candidate) decisions. To compute the winning candidate, previous work has typically assumed that voters send their complete set of preferences for computation, and in fact this has been shown to be required in the worst case. However, in practice, it may be infeasible for all agents to send a complete set of preferences due to communication limitations and willingness to keep as much information private as possible. The goal of this paper is to empirically evaluate algorithms to reduce communication on various sets of experiments. Accordingly, we propose an iterative algorithm that allows the agents to send only part of their preferences, incrementally. Experiments with simulated and real-world data show that this algorithm results in an average of 35% savings in communications, while guaranteeing that the actual winning candidate is revealed. A second algorithm applies a greedy heuristic to save up to 90% of communications. While this heuristic algorithm cannot guarantee that a true winning candidate is found, we show that in practice, close approximations are obtained.     

Activity-rest schedules in physically demanding work and the variation of responses with age

Workers in physically demanding occupations require work breaks to recover from exertion. In a laboratory setting, we investigated the impact of ergometer cycling for 7 h in two conditions with an identical total break time but with two different activity-rest schedules. We hypothesised that more frequent but shorter breaks lead to less psychophysical strain and its effects than do less frequent but longer breaks, particularly for older workers. Twenty-nine participants representing three different age groups were tested in both conditions. Heart rate, perceived exertion/tension and feelings of fatigue were assessed and used as dependent variables. Results indicate no general activity-rest differences as well as no age-related differences of break effects under the condition of subjectively equal straining load. However, heart rate was found to be lower at some measurement points in the frequent-short-break condition and perceived exertion was lower in the infrequent-long-break condition. PRACTITIONER SUMMARY: Design of activity-rest schedules in physically demanding occupations is a key issue in the prevention of strain and hence of interest to ergonomists. Our study suggests that breaks during physically demanding work have the same effect if they are frequent and short or infrequent and long, regardless of age.     

Novel 3D manufacturing method combining microelectrial discharge machining and electrochemical polishing

This paper reports on the potential of microelectrical discharge machining (μEDM) as an innovative method for the fabrication of 3D microdevices. To demonstrate the wide capabilities of μEDM two different microsystems—a microfluidic device for the dispersion of nanoparticles and a star probe for microcoordinate metrology—are presented. To gain optimized process conditions as well as a high surface quality an adequate adaption of the single erosion parameters such as energy, pulse frequency and spark gap has to be carried out and is discussed below. Thus, a surface roughness of R_a?=?80?nm is achieved at the channel bottom. The fabricated stylus elements for the star probe have sphere diameters of 40–200?μm. For further surface quality enhancement a subsequent electrochemical polishing step is investigated. In case of the dispersion micromodule a combined process chain of μEDM-milling and electropolishing has reached a surface improvement above 70%.