Localized patterns and hole solutions in one-dimension extended sytem

The existence, stability properties, and bifurcation diagrams of localized patterns and hole solutions in one-dimensional extended systems is studied from the point of view of front interactions. An adequate envelope equation is derived from a prototype model that exhibits these particle-type solutions. This equation allow us to obtain an analytical expression for the front interaction, which is in good agreement with numerical simulations.Comment: 7 pages, 3 figure

Detecting Physical Collaborations in a Group Task Using Body-Worn Microphones and Accelerometers

This paper presents a method of using wearable accelerometers and microphones to detect instances of ad-hoc physical collaborations between members of a group. 4 people are instructed to construct a large video wall and must cooperate to complete the task. The task is loosely structured with minimal outside assistance to better reflect the ad-hoc nature of many real world construction scenarios. Audio data, recorded from chest-worn microphones, is used to reveal information on collocation, i.e. whether or not participants are near one another. Movement data, recorded using 3-axis accelerometers worn on each person's head and wrists, is used to provide information on correlated movements, such as when participants help one another to lift a heavy object. Collocation and correlated movement information is then combined to determine who is working together at any given time. The work shows how data from commonly available sensors can be combined across multiple people using a simple, low power algorithm to detect a range of physical collaborations

Analysis of the Usefulness of Mobile Eyetracker for the Recognition of Physical Activities

We investigate the usefulness of information from a wearable eyetracker to detect physical activities during assembly and construction tasks. Large physical activities, like carrying heavy items and walking, are analysed alongside more precise, hand-tool activities like using a screwdriver. Statistical analysis of eye based features like fixation length and frequency of fixations show significant correlations for precise activities. Using this finding, we selected 10, calibration-free eye features to train a classifier for recognising up to 6 different activities. Frame-byframe and event based results are presented using data from an 8-person dataset containing over 600 activity events. We also evaluate the recognition performance when gaze features are combined with data from wearable accelerometers and microphones. Our initial results show a duration-weighted event precision and recall of up to 0.69 & 0.84 for independently trained recognition on precise activities using gaze. This indicates that gaze is suitable for spotting subtle precise activities and can be a useful source for more sophisticated classifier fusion

A Slow-Cycling Proton Driver for a Neutrino Factory

An 8 Hz proton driver for a neutrino factory of 4 MW beam power and an energy of 25-30 GeV is under study at CERN, in parallel with a similar investigation using a 2.2 GeV high-energy linac and an accumulator plus a compressor ring cycling at 75 Hz. At RAL, synchrotron drivers with final energies of 5 and 15 GeV cycling at 50 and 25 Hz, respectively, are being studied. With these four scenarios, one hopes to cope with all possible constraints emerging from the studies of the pion production target and the muon rotation and cooling system. The high beam energy of this scenario requires less proton current and could inject into the SPS above transition and upgrade LHC and fixed target physics. Its 440 kW booster would upgrade ISOLDE.The main problems of the driver synchrotron are: the requirement of about 4 MV RF voltage at 10 MHz for acceleration and adiabatic bunch compression to the required r.m.s length of 1 ns; the sensitivity of the compression to the impedance of the vacuum chamber and to non-linearities of the momentum compaction of the high-gt lattice

CERN PS laser ion source development

CERN, together with ITEP and TRINITI (Russia), is developing a CO2 laser ion source. The key design parameters are: 1.4 1010 ions of Pb25+ in a pulse of 5.5 ms, with a 4-rms emittance of 0.2 10-6 rad m, working at a repetition rate of 1 Hz. This device is considered as one candidate source for LHC heavy ion operation. The status of the laser development, the experimental set-up of the source consisting of the target area and its illumination, the plasma expansion area and extraction, beam transport and ion pre-acceleration by an RFQ, will be given

Quadriceps tendinosis and patellar tendinosis in professional beach volleyball players: sonographic findings in correlation with clinical symptoms

The purpose was to assess quadriceps and patellar tendinosis in professional beach volleyball players and to correlate ultrasound findings with clinical symptoms. During a grand-slam beach volleyball tournaments all 202 athletes (100 men and 102 women) were invited to participate at this study. Sixty-one athletes (38 male, mean age 29.6, 23 female, mean age 27.1) were included. The dominant leg was right in 51 (84%) and left in ten athletes (16%). Lysholm knee score and pain during the game was assessed using a visual analogue scale. Sonography of the quadriceps tendon and the patellar tendon was performed by a blinded sonographer. Sonographic findings were compared between both legs and correlated to clinical findings using a regression analysis. Quadriceps tendinosis was diagnosed in 13 (21%, dominant leg)/21 (34%, non-dominant leg), patellar tendinosis in 13(21%)/18(30%). Only sonographic findings at the quadriceps tendon were significantly associated with pain: thickness of the quadriceps tendon (mean diameter 6.9 mm/7.1 mm, significant for both legs P = 0.011/P = 0.030), abnormal echo texture (11/16; P = 0.001/P = 0.228), areas with positive power Doppler signals (mean number 0.3/0.4; P = 0.049/0.346), calcifications (mean number: 0.9/1.1; P = 0.021/0.864). A relationship between findings at patellar tendon was not found. Quadriceps tendinosis is as common as patellar tendinosis in professional beach volleyball players. Thickening and structure alteration of the quadriceps tendon is associated with anterior knee pain during beach volleyball

Emergent behaviour in collaborative indoor localisation: an example of self-organisation in ubiquitous sensing systems

We investigate emergent effects in collaborative indoor localisation as an example of self-organisation in ubiquitous sensing systems. We consider pedestrian dead reckoning (PDR) systems that collaborate to improve their location estimate when two users are detected to be close to each other. In a simulation based on empirically determined parameters we discover two qualitatively different regimes of 'location awareness'. We show that as the frequency of collaborative improvements increases the system makes a transition from a state where the error of each device is unbounded to a state where the averaged maximum error is constant, i.e., location awareness suddenly emerges even though the individual mobile devices are by themselves not capable of exact location and have a tendency to accumulate error without bounds