Performance Analysis of a 5G Transceiver Implementation for Remote Areas Scenarios

The fifth generation of mobile communication networks will support a large set of new services and applications. One important use case is the remote area coverage for broadband Internet access. This use case ha significant social and economic impact, since a considerable percentage of the global population living in low populated area does not have Internet access and the communication infrastructure in rural areas can be used to improve agribusiness productivity. The aim of this paper is to analyze the performance of a 5G for Remote Areas transceiver, implemented on field programmable gate array based hardware for real-time processing. This transceiver employs the latest digital communication techniques, such as generalized frequency division multiplexing waveform combined with 2 by 2 multiple-input multiple-output diversity scheme and polar channel coding. The performance of the prototype is evaluated regarding its out-of-band emissions and bit error rate under AWGN channel.Comment: Presented in 2018 European Conference on Networks and Communications (EuCNC),18-21 June, 2018, Ljubljana, Sloveni

Robust preconditioners for a new stabilized discretization of the poroelastic equations

In this paper, we present block preconditioners for a stabilized discretization of the poroelastic equations developed in [45]. The discretization is proved to be well-posed with respect to the physical and discretization parameters, and thus provides a framework to develop preconditioners that are robust with respect to such parameters as well. We construct both norm-equivalent (diagonal) and field-of-value-equivalent (triangular) preconditioners for both the stabilized discretization and a perturbation of the stabilized discretization that leads to a smaller overall problem after static condensation. Numerical tests for both two- and three-dimensional problems confirm the robustness of the block preconditioners with respect to the physical and discretization parameters

Developing Dynamic Audio Navigation UIs to Pinpoint Elements in Tactile Graphics

Access to complex graphical information is essential when connecting blind and visually impaired (BVI) people with the world. Tactile graphics readers enable access to graphical data through audio-tactile user interfaces (UIs), but these have yet to mature. A challenging task for blind people is locating specific elements–areas in detailed tactile graphics. To this end, we developed three audio navigation UIs that dynamically guide the user’s hand to a specific position using audio feedback. One is based on submarine sonar sounds, another relies on the target’s coordinate plan x and y-axis, and the last uses direct voice instructions. The UIs were implemented in the Tactonom Reader device, a new tactile graphic reader that enhances swell paper graphics with pinpointed audio explanations. To evaluate the effectiveness of the three different dynamic navigation UIs, we conducted a within-subject usability test that involved 13 BVI participants. Beyond comparing the effectiveness of the different UIs, we observed and recorded the interaction of the visually impaired participants with the different navigation UI to further investigate their behavioral patterns during the interaction. We observed that user interfaces that required the user to move their hand in a straight direction were more likely to provoke frustration and were often perceived as challenging for blind and visually impaired people. The analysis revealed that the voice-based navigation UI guides the participant the fastest to the target and does not require prior training. This suggests that a voice-based navigation strategy is a promising approach for designing an accessible user interface for the blind

Revised Coordinates and Proper Motions of the Stars in the Luyten Half-Second Catalogue

We present refined coordinates and proper motion data for the high proper motion (HPM) stars in the Luyten Half-Second (LHS) catalogue. The positional uncertainty in the original Luyten catalogue is typically >10" and is often >30". We have used the digital scans of the Palomar Observatory Sky Survey (POSS) I and POSS II plates to derive more accurate positions and proper motions of the objects. Out of the 4470 candidates in the LHS catalogue, 4323 objects were manually re-identified in the POSS I and POSS II scans. A small fraction of the stars were not found due to the lack of finder charts and digitized POSS II scans. The uncertainties in the revised positions are typically ~2", but can be as high as ~8" in a few cases; this is a large improvement over the original data. Cross-correlation with the Tycho-2 and Hipparcos catalogues yielded 819 candidates (with m_R < 12). For these brighter sources, the position and proper motion data have been replaced with the more accurate Tycho/Hipparcos data. In total, we have revised proper motion measurements and coordinates for 4040 stars and revised coordinates for 4330 stars, which are presented here.Comment: 108 pages. Accepted for Publication in ApJ Suppl. Some errors caused by the transcription errors in the original LHS catalogue have been corrected in this resubmission. The most current version of the catalogue is also available online at http://www.stsci.edu/~ksahu/lh

The contribution of the major planet search surveys to EChO target selection

The EChO core science will be based on a three tier survey, each with increasing sensitivity, in order to study the population of exo-planets from super-Earths to Jupiter-like planets, in the very hot to temperate zones (temperatures of 300 K - 3000 K) of F to M-type host stars. To achieve a meaningful outcome an accurate selection of the target sample is needed. In this paper we analyse the targets, suitable for EChO observations, expected to result from a sample of present and forthcoming detection surveys. Exoplanets currently known are already sufficient to provide a large and diverse sample. However we expect the results from these surveys to increase the sample of smaller planets that will allow us to optimize the EChO sample selection.Comment: Submitted to Experimental Astronom

CONTROL OF LEG STIFFNESS AND ITS EFFECT ON MECHANICAL ENERGETIC

INTRODUCTION: In normal daily activity as in sports, humans adjust their physical behavior depending on the ground surface characteristics (Farley et al., 1998; Ferris, Liang & Farley, 1999) by being able to vary their performance (Arampatzis, 1999; Sanders, 1993). A difference in surface stiffness leads to a change in leg stiffness (Farley et al., 1998; Ferris, Liang & Farley, 1999). There are published results on relationships between joint stiffness and oxygen consumption (Dalleau et al., 1998; Heise & Martin, 1993). From this research, it can be concluded that leg stiffness influences athletic performance. The relationship between leg stiffness and performance during explosive movements on a sprung surface has not been reported in the literature to date. Leg Stiffness can be influenced by stride frequency while running (Farley & Gonzalez, 1996) or hopping frequency when bouncing in place (Farley & Morgenroth, 1999). These findings support the idea that it is possible to control leg stiffness by manipulating ground contact times and to consider its effects on mechanical energetic processes during drop jumps on a sprung surface. The purpose of this study is two-fold: a. Examinations of the effect of verbal instructions, given to the subjects for the control of lower -extremity stiffness. b. Assessment of the effect of the leg stiffness on mechanical energetic processes during drop jumps on a sprung surface

Optimal selection of weighting functions by genetic algorithms to design H∞ Anti-roll bar controllers for heavy vehicles

International audienceMulti-criterion optimization is so far popular for many complex engineering problems. The objective of active anti-roll bar of heavy vehicles is to maximize roll stability to prevent rollover in dangerous cases. However, such a performance objective must be balanced with the energy consumption of the anti-roll bar system, which is not a trivial task. In a previous work, the authors proposed an H∞ active anti-roll bar controller for which the weighting functions were chosen by trials and errors during the design step. In this paper, Genetic Algorithms (GAs) are proposed to find optimal weighting functions for the H∞ control synthesis. Such a general procedure is applied to the case of active anti-roll bar control in heavy vehicles. Thanks to GAs, the conflicting objectives between roll stability and torques generated are handled using one high level parameter only. The multi-criterion optimization solution is illustrated via the Pareto frontier. Simulations, performed in the frequency and time domains, emphasize the efficiency of the proposed method

DIFFERENCES IN MUSCULAR CONTROL AND GROUND REACTION FORCES IN SUBJECTS WITH STABLE AND UNSTABLE ANKLES

The aim of this study was to investigate if there is a common behaviour distinguishing subjects with stable ankles from those with unstable ankles. Therefore the muscular response and the ground reaction forces (GRF) of 24 subjects performing horizontal jumps and also drop landings from a 40cm high box, on three different surfaces (a level one and two surfaces inclined 3° either laterally or medially) were measured. Eight parameters of the EMG signals from each of six muscles of the lower leg and several GRF parameters (eight for jumping and seven for landing) were analysed. EMG data reveal that stable subjects have higher mean power frequencies (MPF), whereas unstable subjects increase their amplitudes. The GRFs show significant differences (

A concept for a novel polymer extruder part 1: active grooved feed section

This paper presents a novel concept for an extruder to be used with plastics and polymer composites, especially in the food industry. The design solutions include a grooved feed section with adjustable geometric parameters, which makes it possible for dynamic adjustment of the depth, inclination angle and number of grooves used for granulate transport during continuous operation of the machine. The proposed grooved feed section concept facilitates optimum performance, and is adjustable to suit the general parameters of production. The scope of our study also included the numerical strength and thermal analysis of the designed grooved feed section, conducted using the finite element method. Numerical calculation involved a coupled temperaturedisplacement analysis which constituted a geometrically and physically non-linear problem. The results corroborated the achievement of satisfactory strength for the structural elements of the grooved feed section in the extruder and demonstrated the suitability of the adopted solution in terms of temperature distribution in the parts of the machine, as well as the correct concept of the rcial program