A unified approach to accessibility for a person in a wheelchair

Adapting the environment for a person with physical needs consists first and foremost to assess areas that may pose a problem of accessibility. Two problems arise: the person seated in a wheelchair must be able to approach an object and then grasp it. The placement of the mobility device has a significant influence on the grasping capabilities. We propose in this paper a unified method for evaluating the accessibility of objects in a domestic environment. The idea is to model the human articulated system and the mobility device and then to evaluate the existence of a global solution of the inverse kinematics. We propose to use our methodology to label a complete environment by checking at each point, whether it is accessible or not to a person, whose joint constraints are known, for moving in an indoor environment with obstacles.     

Modeling the stimulators of the behavioral intention to use mobile entertainment: Does gender really matter?

This research aims to empirically examine the stimulators that influence consumers’ behavioral intention to use (IU) mobile entertainment (ME) in Malaysia. The proposed stimulators are perceived usefulness (PU), perceived ease of use (PEOU), social influence (SI), perceived self-efficacy (PSE) and perceived enjoyment (PE). PU and PEOU were derived from TAM, SI was taken from the TRA, TPB and DOI model, PE was obtained from the extended-TAM model and PSE was taken from Bandura’s theory. This is among the first study that uses a model consisting of integrated constructs from TAM, extended-TAM, TRA, TPB, DOI and Bandura’s theory in predicting acceptance of ME. Empirical data were analyzed by employing Structural Equation Modeling (SEM) analysis. Gender moderating effect was examined via multiple group analysis (MGA). The findings revealed that PU, PEOU, SI and PE are positively associated with consumer IU of ME. Surprisingly, there were no significant moderating effects of gender. The control variables (i.e. age, marital status, education level, number of mobile phone and experience) were found to have no confounding effects on the ME adoption. The findings have contributed theoretical and managerial implications to ME providers, mobile phone manufacturers, the music, movie and gaming industry players.     

Prediction of Online Students Performance by Means of Genetic Programming

ABSTRACT

Problem: Online higher education (OHE) failure rates reach 40% worldwide. Prediction of student performance at early stages of the course calendar has been proposed as strategy to prevent student failure.

Objective: To investigate the application of genetic programming (GP) to predict the final grades (FGs) of online students using grades from an early stage of the course as the independent variable

Method: Data were obtained from the learning management system; we performed statistical analyses over FGs as dependent variable and 11 independent variables; two statistical and one GP models were generated; the prediction accuracies of the models were compared by means of a statistical test.

Results: GP model was better than statistical models with confidence levels of 90% and 99% for the training testing data sets respectively. These results suggest that GP could be implemented for supporting decision making process in OHE for early student failure prediction.     

Micropatterning PEDOT:PSS layers

PEDOT:PSS is a conductive polymer that is used as electrodes in organic electronic devices, but also in neuronal probes and implantable devices. This material can also be used for building deformable electrodes in soft substrates for several sensing applications. However, this material being sensitive to several chemicals and moisture it is difficult to pattern microstructures using standard lithography techniques. This paper will review and show some techniques developed for patterning PEDOT:PSS thin films using both soft lithography, such as microcontact printing and shadow masking, and conventional lithography techniques. In addition of this review we present a new lithography technique using silicon nitride protection layer and an analysis and comparison of ICP RIE dry plasma etch rates of PEDOT:PSS with different gases.     

A residual-based compact scheme of optimal order for hyperbolic problems

A new fourth-order dissipative scheme on a compact 3 × 3 stencil is presented for solving 2D hyperbolic problems. It belongs to the family of previously developed residual-based compact schemes and can be considered as optimal since it offers the maximum achievable order of accuracy on the 3 × 3-point stencil. The computation of 2D scalar problems demonstrates the excellent accuracy and efficiency properties offered by this new RBC scheme with respect to existing second- and third-order versions.     

Tracking the dynamics of translation and absolute orientation of a sphere in a turbulent flow

We study the six-dimensional dynamics--position and orientation--of a large sphere advected by a turbulent flow. The movement of the sphere is recorded with two high-speed cameras. Its orientation is tracked using a novel, efficient algorithm; it is based on the identification of possible orientation "candidates" at each time step, with the dynamics later obtained from maximization of a likelihood function. Analysis of the resulting linear and angular velocities and accelerations reveal a surprising intermittency for an object whose size lies in the inertial range, close to the integral scale of the underlying turbulent flow.     

Autonomous rigid body attitude synchronization

Control laws to synchronize attitudes in a swarm of fully actuated rigid bodies, in the absence of a common reference attitude or hierarchy in the swarm, are proposed in [Smith, T. R., Hanssmann, H., & Leonard, N.E. (2001). Orientation control of multiple underwater vehicles with symmetry-breaking potentials. In Proc. 40th IEEE conf. decision and control (pp. 4598-4603); Nair, S., Leonard, N. E. (2007). Stable synchronization of rigid body networks. Networks and Heterogeneous Media, 2(4), 595-624]. The present paper studies two separate extensions with the same energy shaping approach: (i) locally synchronizing the rigid bodies’ attitudes, but without restricting their final motion and (ii) relaxing the communication topology from undirected, fixed and connected to directed, varying and uniformly connected. The specific strategies that must be developed for these extensions illustrate the limitations of attitude control with reduced information.     

Étude théorique et expérimentale d’une modulation simplifiée par déplacement de fréquence d’indice 1/2 à phase continue

The minimum shift keying modulation (MSK)to which a lot of recent publications have been done,presents some advantage about linear and non-linear distortions towards common 2 or 4 Phase Shift Keying (PSK)modulations. The simplified MSK modulation described in this paper is obtained by linear filtering of a coherent 2 phase shift keying modulation. Then the demodulator can be implemented with a matched filter followed by a coherent demodulator using only one carrier recovery circuit. In the first part of this paper, the modulator and the demodulator are described. After, some theorical results in the presence of noise and other impairments are given. In CCETT laboratories at Rennes, a modem has been realized at a data rate of 2,048 Mbit/s and performs at 0,8 dB of the theoretical results.     

北方乡村生态屋设计实践

本论文给出在恶劣条件下,改善北方乡村居民居住质量、创造舒适与生态的人居环境的设计策略与技术手段,论文通过对当地传统民居与生态屋进行的同步测试、评估与比较分析,验证了生态屋生态技术的有效性,为北方乡村住宅建设的可持续发展指明了方向。     

New generation photon-counting cameras: algol and CPNG

Algol and Comptage de Photons Nouvelle Génération (CPNG) are new generation photon counting cameras developed for high angular resolution in the visible by means of optical aperture synthesis and speckle interferometry and for photon noise limited fast imaging of biological targets. They are intensified CCDs. They have been built to benefit from improvements in photonic commercial components, sensitivity, and personal computer workstations processing power. We present how we achieve optimal performances (sensitivity and spatiotemporal resolution) by the combination of proper optical and electronics design, and real-time elaborated data processing. The number of pixels is 532 x 516 and 1024(2) read at a frame rate of 262 and 100 Hz for CPNG and Algol, respectively. The dark current is very low: 5.5 x 10(-4) e(-) .pixel(-1). s(-1). The saturation flux is approximately 7 photon events /pixel/s. Quantum efficiencies reach up to 36% and 26% in the visible with the GaAsP photocathodes and in the red with the GaAs ones, respectively, thanks to the sensitivity of the photocathodes and to the photon centroiding algorithm; they are likely the highest values reported for intensified CCDs.