Automatic Identification System (AIS) provides estimated position time along with reception time and a time stamp at the receiving station; however, the exact position estimation time remains unidentified. Therefore, this study examines the extent of positional error when using current AIS reception time. As a result, a maximum positional error of 116.9 m was observed between AIS and RTK-GPS (Real-Time Kinematic GPS). Subsequent time correction reduced this error to less than 10 m, with the product of ship speed and correction time nearly matching the error pre-correction. Consequently, it was concluded that transmitting position estimation time is essential for maintaining the reliability of Position Accuracy transmitted by AIS or VHF Data Exchange System (VDES). Furthermore, VDES may possess the communication capacity to transmit and receive vessel attitude data. Therefore, to assess the required transmission frequency, the data transmission period of roll and pitch attitude data was analysed through the mutual correlation of acceleration and angular velocity. The results indicated that the correlation coefficient for each axis exceeded 0.65 at frequencies of 0.5 Hz or higher.

Mean corrected higher order sample moments are asymptotically normally distributed. It is shown that both in the literature and popular software the estimates of their asymptotic covariance matrices are incorrect. An introduction to the infinitesimal jackknife is given and it is shown how to use it to correctly estimate the asymptotic covariance matrices of higher order sample moments. Another advantage in using the infinitesimal jackknife is the ease with which it may be used when stacking or sub-setting estimators. The estimates given are used to test the goodness of fit of a non-linear factor analysis model. A computationally accelerated form for infinitesimal jackknife estimates is given.

The aim of this study was to investigate the combined effect of driver and driving style on the behaviour, salivary cortisol concentration, and heart-rate variability of pigs during a short journey. In addition, the effect of differing accelerations (longitudinal, lateral, and vertical) of the trailer on these variables was studied. One hundred and thirty-five cross-bred pigs (Piétrain × Hypor) were transported in groups of five on a trailer towed by a jeep. Three different drivers transported the pigs using a normal, a quiet, and a wild driving style (the latter two in relation to their normal style). Driving style mainly had an effect on the longitudinal and lateral accelerations. Salivary cortisol increases were lowest for the wild driving style. The latter can be explained by the shorter duration of these journeys and not by the accelerations, thus it is our view that acceleration due to manoeuvring as opposed to acceleration due to overall speed should be avoided. Also, in practice, journeys should take as brief a time as possible. Increasing acceleration saw an increase in the proportion of pigs standing during the journey and a decrease in the proportion of pigs lying down. Measurements of variability in heart rate revealed that lateral acceleration was an important stressor for pigs. We concluded that, as driving style has an effect on different stress variables, increased driver awareness of the effects of their driving on the responses of pigs, would improve pig welfare.

We consider the sum $\sum 1/\gamma $, where $\gamma $ ranges over the ordinates of nontrivial zeros of the Riemann zeta-function in an interval $(0,T]$, and examine its behaviour as $T \to \infty $. We show that, after subtracting a smooth approximation $({1}/{4\pi }) \log ^2(T/2\pi ),$ the sum tends to a limit $H \approx -0.0171594$, which can be expressed as an integral. We calculate H to high accuracy, using a method which has error $O((\log T)/T^2)$. Our results improve on earlier results by Hassani [‘Explicit approximation of the sums over the imaginary part of the non-trivial zeros of the Riemann zeta function’, Appl. Math. E-Notes 16 (2016), 109–116] and other authors.

The purpose of this study was to examine whether vehicle type based on size (car vs. other = truck/van/SUV) had an impact on the speeding, acceleration, and braking patterns of older male and female drivers (70 years and older) from a Canadian longitudinal study. The primary hypothesis was that older adults driving larger vehicles (e.g., trucks, SUVs, or vans) would be more likely to speed than those driving cars. Participants (n = 493) had a device installed in their vehicles that recorded their everyday driving. The findings suggest that the type of vehicle driven had little or no impact on per cent of time speeding or on the braking and accelerating patterns of older drivers. Given that the propensity for exceeding the speed limit was high among these older drivers, regardless of vehicle type, future research should examine what effect this behaviour has on older-driver road safety.

The objective of this study was to develop an automated monitoring system to detect lameness in group-housed sows early and reliably on the basis of acceleration data sampled from ear tags. To this end, acceleration data from ear tags were acquired from an experimental system deployed at the Futterkamp Agriculture Research Farm from May 2012 until November 2013. The developed method performs a wavelet transform for each individual sow’s time series of total acceleration. Feature series are then computed by locally estimating the energy, variation and variance in a small moving window. These feature series are then further decomposed into uniform level sets. From these series of level sets, the highest and lowest levels are monitored for lameness detection. To that end, they are split into a past record to serve as reference data representing a sow’s expected behaviour. The deviations between the reference and the remaining detection part of current data, termed feature activated, were then utilised to possibly indicate a lameness condition. The method was applied to a sample of 14 sows, seven of which were diagnosed as lame by a veterinarian on the last day of the sampling period of 14 days each. A prediction part of 3 days was set. Feature activated were clearly separable for the lame and healthy group with means of 8.8 and 0.8, respectively. The day-wise means were 1.93, 9.47 and 15.16 for the lame group and 0.02, 1.13 and 1.44 for the healthy group. A threshold could be set to completely avoid false positives while successfully classifying six lame sows on at least one of the 2 last days. The accuracy values for this threshold were 0.57, 0.71 and 0.78 when restricting to data from the particular day. A threshold that maximised the accuracy achieved values of 0.57, 0.79 and 0.93. Thus, the method presented seems powerful enough to suggest that an individual classification from ear tag-sampled acceleration data into lame and healthy is feasible without previous knowledge of the health status, but has to be validated by using a larger data set.

The ultrafast charge dynamics following the interaction of an ultra-intense laser pulse with a foil target leads to the launch of an ultra-short, intense electromagnetic (EM) pulse along a wire connected to the target. Due to the strong electric field (of the order of $\text{GV m}^{-1}$) associated to such laser-driven EM pulses, these can be exploited in a travelling-wave helical geometry for controlling and optimizing the parameters of laser accelerated proton beams. The propagation of the EM pulse along a helical path was studied by employing a proton probing technique. The pulse-carrying coil was probed along two orthogonal directions, transverse and parallel to the coil axis. The temporal profile of the pulse obtained from the transverse probing of the coil is in agreement with the previous measurements obtained in a planar geometry. The data obtained from the longitudinal probing of the coil shows a clear evidence of an energy dependent reduction of the proton beam divergence, which underpins the mechanism behind selective guiding of laser-driven ions by the helical coil targets.

Temporo-spatial observation of the leg could provide important information about the general condition of an animal, especially for those such as sheep and other free-ranging farm animals that can be difficult to access. Tri-axial accelerometers are capable of collecting vast amounts of data for locomotion and posture observations; however, interpretation and optimization of these data records remain a challenge. The aim of the present study was to introduce an optimized method for gait (walking, trotting and galloping) and posture (standing and lying) discrimination, using the acceleration values recorded by a tri-axial accelerometer mounted on the hind leg of sheep. The acceleration values recorded on the vertical and horizontal axes, as well as the total acceleration values were categorized. The relative frequencies of the acceleration categories (RFACs) were calculated in 3-s epochs. Reliable RFACs for gait and posture discrimination were identified with discriminant function and canonical analyses. Post hoc predictions for the two axes and total acceleration were conducted, using classification functions and classification scores for each epoch. Mahalanobis distances were used to determine the level of accuracy of the method. The highest discriminatory power for gait discrimination yielded four RFACs on the vertical axis, and five RFACs each on the horizontal axis and total acceleration vector. Classification functions showed the highest accuracy for walking and galloping. The highest total accuracy on the vertical and horizontal axes were 90% and 91%, respectively. Regarding posture discrimination, the vertical axis exhibited the highest discriminatory power, with values of RFAC (0, 1]=99.95% for standing; and RFAC (−1, 0]=99.50% for lying. The horizontal axis showed strong discrimination for the lying side of the animal, as values were in the acceleration category of (0, 1] for lying on the left side and (−1, 0] on the right side. The algorithm developed by the method employed in the present study facilitates differentiation of the various types of gait and posture in animals from fewer data records, and produces the most reliable acceleration values from only one axis within a short time frame. The present study introduces an optimized method by which the tri-axial accelerometer can be used in gait and posture discrimination in sheep as an animal model.

Lameness is an important issue in group-housed sows. Automatic detection systems are a beneficial diagnostic tool to support management. The aim of the present study was to evaluate data of a positioning system including acceleration measurements to detect lameness in group-housed sows. Data were acquired at the Futterkamp research farm from May 2012 until April 2013. In the gestation unit, 212 group-housed sows were equipped with an ear sensor to sample position and acceleration per sow and second. Three activity indices were calculated per sow and day: path length walked by a sow during the day (Path), number of squares (25×25 cm) visited during the day (Square) and variance of the acceleration measurement during the day (Acc). In addition, data on lameness treatments of the sows and a weekly lameness score were used as reference systems. To determine the influence of a lameness event, all indices were analysed in a linear random regression model. Test day, parity class and day before treatment had a significant influence on all activity indices (P<0.05). In healthy sows, indices Path and Square increased with increasing parity, whereas variance slightly decreased. The indices Path and Square showed a decreasing trend in a 14-day period before a lameness treatment and to a smaller extent before a lameness score of 2 (severe lameness). For the index acceleration, there was no obvious difference between the lame and non-lame periods. In conclusion, positioning and acceleration measurements with ear sensors can be used to describe the activity pattern of sows. However, improvements in sampling rate and analysis techniques should be made for a practical application as an automatic lameness detection system.

Laser ion acceleration (Wilks et al., 2001; Passoni et al., 2010) has become an interesting field of research in the past years. Several experiments, such as LIGHT (Schollmeier et al., 2008; Bagnoud et al., 2010; Busold et al., 2013; 2014a; 2014b) are performed worldwide. High intense, pulsed laser beams are used to generate and accelerate a plasma. For higher laser intensities (>1021 W cm−1), simulations (Esirkepov et al., 2004; Macchi et al., 2005; 2009; 2010; Robinson et al., 2008; Rykovanov et al., 2008; Henig et al., 2009; Schlegel et al., 2009; Shoucri et al., 2011; 2013; 2014; Kar et al., 2012; Korzhimanov et al., 2012; Shoucri, 2012) have revealed a new acceleration mechanism: The Radiation Pressure Acceleration. The entire foil target is accelerated by the radiation pressure of the laser pulse. Ideally, a sharp peak spectrum is generated, with energies up to GeV and nearly solid body density. This work faces on a detailed analysis of the acceleration mechanism in order to develop the optimum laser- and target parameters for the process. The analysis is supported by one-dimensional PIC simulations, using the commercial code VSim© Tech-X (2015).

This study examines the production of consonant clusters in simultaneous Polish–English bilingual children and in language-matched English monolinguals (aged 7;01–8;11). Selection of the language pair was based on the fact that Polish allows a greater range of consonant clusters than English. A nonword repetition task was devised in order to examine clusters of different types (obstruent-liquid vs. s + obstruent) and in different word positions (initial vs. medial), two factors that play a significant role in repetition accuracy in monolingual acquisition (e.g., Kirk & Demuth, 2005). Our findings show that bilingual children outperformed monolingual controls in the word initial s + obstruent condition. These results indicate that exposure to complex word initial clusters (in Polish) can accelerate the development of less phonologically complex clusters (in English). This constitutes significant new evidence that the facilitatory effects of bilingual acquisition extend to structural phonological domains. The implications that these results have on competing views of phonological organisation and phonological complexity are also discussed.

Our numerical simulations show that the reconnection of magnetic field becomes fast in the presence of weak turbulence in the way consistent with the Lazarian & Vishniac (1999) model of fast reconnection. This process in not only important for understanding of the origin and evolution of the large-scale magnetic field, but is seen as a possibly efficient particle accelerator producing cosmic rays through the first order Fermi process. In this work we study the properties of particle acceleration in the reconnection zones in our numerical simulations and show that the particles can be efficiently accelerated via the first order Fermi acceleration.

Introduction: In squamous-cell carcinoma (SCC) of the head and neck, unplanned gaps risk prolongation of the overall treatment time (OTT) and reduction in tumour control. This audit determines whether further acceleration can safely be employed to compensate for missed treatments during accelerated hypofractionated radiotherapy.

Methods: Patients receiving accelerated hypofractionated radiotherapy for SCC of the head and neck were prospectively audited. Outcome measures were OTT, degree of compensation and acute toxicity determined by incidence of grade 3 mucositis, prolonged grade 3 mucositis, grade 3 dysphagia and pain.

Results: In the 87 patients identified, the dose administered was 55 Gy in 20 fractions (81 patients), 50 Gy in 20 fractions (1 patient) and 50 Gy in 16 fractions (5 patients). Of those patients receiving 20 fractions, 94% completed within 28 days. Grade 3 mucositis was seen in 56 patients (64%). Compensating for unplanned gaps did not result in any significant increase in toxicity. Administering 6 fractions/week, as compensation, was associated with a lower pain score (p = 0.003) as was receiving 2 fractions on the same day (p = 0.0004).

Conclusions: Accelerated hypofractionation is tolerable with most patients completing treatment within the planned OTT. When unplanned gaps occur, then compensation by further acceleration is possible.

Impact is considered the most critical part of the stance phase for the development of chronic articular disorders such as osteoarthritis in the equine distal limb. Modern, synthetic shoeing materials are believed to modify impact and therefore are often used to treat an/r prevent lameness due to chronic joint disorders. Scientific evidence is scarce, however, to prove this. Hoof impact of forelimb was compared quantitatively in a group of horses under three conditions: unshod, classical steel shoes and shod with a synthetic shoe. Twelve sound warmblood horses were trotted by hand on an asphalt track at a mean speed of 3.5ms−1 and measured in a Latin square design (unshod condition, with steel shoes and with polyurethane (PU) shoes) using a triaxial accelerometer that had been fixed to the lateral hoof wall of the left forelimb. The sampling frequency was set at 10kHz per channel. The maximum amplitude of vertical and horizontal, forwar/ackward accelerations at hoof impact was lowest when shod using the PU shoeing condition (P<0.05), but the duration of the impact vibrations was lowest when unshod. PU shoes cause more damping, less friction and slower shock absorption at hoof level compared with the other two conditions and thus modify impact. Synthetic, polyurethane shoes may help in reducing peak vibrations. These short-term effects appear to be promising enough to evaluate PU shoes under field conditions in reducing impact on the longer term after substantial wear and tear. Furthermore, the possible role of synthetic materials in repairing critical tissues or even in preventing osteoarthritis in horses warrants further investigation.