In situ growth regime characterization of cubic GaN using reflection high energy electron diffraction

Cubic GaN layers were grown by plasma-assisted molecular beam epitaxy on 3C-SiC (001)substrates. In situ reflection high energy electron diffraction was used to quantitatively determine the Ga coverage of the GaN surface during growth. Using the intensity of the electron beam as a probe,optimum growth conditions of c-GaN were found when a 1 ML Ga coverage is formed at the surface. 1 micrometer thick c-GaN layers had a minimum surface roughness of 2.5 nm when a Ga coverage of 1 ML was established during growth. These samples revealed also a minimum full width at half maximum of the (002)rocking curve.Comment: 3pages with 4 figure

Domestic Violence, Substance Abuse, and Child Welfare: the Legal System\u27s Response

This Article begins by exploring and documenting the connections between domestic violence, substance abuse, and child abuse. Part II of the Article examines the legal system\u27s response to child protection cases in which maternal abuse and, in some cases, substance abuse are present. This section begins by describing the shifting theories underlying child welfare in this country. It then contrasts these theories with child welfare practice by reporting the results of a study of eighty-five Child in Need of Assistance (CINA) cases in four jurisdictions in Maryland. Although the study examines a limited sample, the cases examined confirm the strong connection between domestic violence, substance abuse, and child protection intervention. In addition, the study reveals the substantial obstacles to developing appropriate child welfare policies in a system that is 1) severely underfunded; 2) not designed to appropriately screen for domestic violence and substance abuse problems; and 3) able to provide only the most rudimentary and boilerplate services and referrals to deal with these problems. Any effort to refocus child welfare politics on family preservation must begin by addressing these issues. Reform efforts that seek to repeal or change ASFA may shift attention from the real barrier to effective assistance to families at risk. The Article concludes by calling for a shift in public policy priorities and summarizing the most promising proposals for improving a child protection system which must respond to these multiple problems

Nonlinear bias correction for satellite data assimilation using Taylor series polynomials

Output from a high-resolution ensemble data assimilation system is used to assess the ability of an innovative nonlinear bias correction (BC) method that uses a Taylor series polynomial expansion of the observation-minus background departures to remove linear and nonlinear conditional biases from all-sky satellite infrared brightness temperatures. Univariate and multivariate experiments were performed in which the satellite zenith angle and variables sensitive to clouds and water vapor were used as the BC predictors. The results showed that even though the bias of the entire observation departure distribution is equal to zero regardless of the order of the Taylor series expansion, there are often large conditional biases that vary as a nonlinear function of the BC predictor. The linear 1st order term had the largest impact on the entire distribution as measured by reductions in variance; however, large conditional biases often remained in the distribution when plotted as a function of the predictor. These conditional biases were typically reduced to near zero when the nonlinear 2nd and 3rd order terms were used. The univariate results showed that variables sensitive to the cloud top height are effective BC predictors especially when higher order Taylor series terms are used. Comparison of the statistics for clear-sky and cloudy-sky observations revealed that nonlinear departures are more important for cloudy-sky observations as signified by the much larger impact of the 2nd and 3rd order terms on the conditional biases. Together, these results indicate that the nonlinear BC method is able to effectively remove the bias from all-sky infrared observation departures

Retention and generalizability of balance recovery response adaptations from trip-perturbations across the adult lifespan

For human locomotion, varying environments require adjustments of the motor system. We asked whether age affects gait balance recovery adaptation, its retention over months and the transfer of adaptation to an untrained reactive balance task. Healthy adults (26 young, 27 middle-aged and 25 older; average ages 24, 52 and 72 years respectively) completed two tasks. The primary task involved treadmill walking: either unperturbed (control; n=39) or subject to unexpected trip perturbations (training; n=39). A single trip perturbation was repeated after a 14-week retention period. The secondary transfer task, before and after treadmill walking, involved sudden loss of balance in a lean-and-release protocol. For both tasks the anteroposterior margin of stability (MoS) was calculated at foot touchdown. For the first (i.e. novel) trip, older adults required one more recovery step ( P=0.03) to regain positive MoS compared to younger, but not middle-aged, adults. However, over several trip perturbations, all age groups increased their MoS for the first recovery step to a similar extent (up to 70%), and retained improvements over 14 weeks, though a decay over time was found for older adults ( P=0.002; middle-aged showing a tendency for decay: P=0.076). Thus, although adaptability in reactive gait stability control remains effective across the adult lifespan, retention of adaptations over time appears diminished with aging. Despite these robust adaptations, the perturbation training group did not show superior improvements in the transfer task compared to aged-matched controls (no differences in MoS changes), suggesting that generalizability of acquired fall-resisting skills from gait-perturbation training may be limited

A Decade of Shared Tasks in Digital Text Forensics at PAN

[EN] Digital text forensics aims at examining the originality and credibility of information in electronic documents and, in this regard, to extract and analyze information about the authors of these documents. The research field has been substantially developed during the last decade. PAN is a series of shared tasks that started in 2009 and significantly contributed to attract the attention of the research community in well-defined digital text forensics tasks. Several benchmark datasets have been developed to assess the state-of-the-art performance in a wide range of tasks. In this paper, we present the evolution of both the examined tasks and the developed datasets during the last decade. We also briefly introduce the upcoming PAN 2019 shared tasks.We are indebted to many colleagues and friends who contributed greatly to PAN's tasks: Maik Anderka, Shlomo Argamon, Alberto Barrón-Cedeño, Fabio Celli, Fabio Crestani, Walter Daelemans, Andreas Eiselt, Tim Gollub, Parth Gupta, Matthias Hagen, Teresa Holfeld, Patrick Juola, Giacomo Inches, Mike Kestemont, Moshe Koppel, Manuel Montes-y-Gómez, Aurelio Lopez-Lopez, Francisco Rangel, Miguel Angel Sánchez-Pérez, Günther Specht, Michael Tschuggnall, and Ben Verhoeven. Our special thanks go to PAN¿s sponsors throughout the years and not least to the hundreds of participants.Potthast, M.; Rosso, P.; Stamatatos, E.; Stein, B. (2019). A Decade of Shared Tasks in Digital Text Forensics at PAN. Lecture Notes in Computer Science. 11438:291-300. https://doi.org/10.1007/978-3-030-15719-7_39S2913001143

THE SUCCESS OF A SOCCER KICK DEPENDS ON RUN UP DECELERATION

The purpose of the study was to relate the motion of the centre of mass (CoM) during run ups in soccer full insteps kicks with the obtained ball speeds. Nineteen experienced play-ers performed kicks onto the goal and their full body kinematics as well as ball motion were analysed in three dimensions using two high speed video cameras. Higher decel-erations of the CoM with the last step are associated with higher ball velocities and higher thigh angular impulses. Those data suggest, that an intensive breaking of the CoM veloc-ity provides a prerequisite to transfer a portion of the CoM impulse into angular impulse of the thigh. High angular impulse of the thigh however can be beneficial for fast instep kicks

THE EFFECT OF DIFFERENT FOOTWEAR ON THE MYOELECTRIC ACTIVITY OF M. TIBIALIS POSTERIOR DURING TREADMILL RUNNING

Overload running injuries of the lower extremity, particularly the knee, are associated with excessive pronation of the foot resulting in tibial rotation (Nigg et al., 1995). M. tibialis posterior (TP) is shown to have an active influence on pronation and the medial longitudinal arch (Kaye & Jahss, 1991). Its functional role during running and interaction with footwear is still not clearly understood (Reber et al., 1993; O’Connor & Hamill, 2004). Therefore the purpose of this study is to investigate the influence of different footwear on the muscle’s EMG pattern

WIRE EMG OF FLEXOR HALLUCIS LONGUS DURING BAREFOOT AND SHOD RUNNING ON A TREADMILL: A PILOT STUDY

Excessive pronation is associated with overload injuries of the lower extremity (Nigg, 1995). The flexor hallucis longus (FHL) acts against the pronation of the calcaneus (Klein, 1996). The influence of different footwear on the activity of the FHL was neither measured in walking nor running. The purpose of this study was to investigate the activity of the FHL during different phases in stance of walking and running in different footwear conditions

Simplified modeling of EM field coupling to complex cable bundles

In this contribution, the procedure "Equivalent Cable Bundle Method" is used for the simplification of large cable bundles, and it is extended to the application on differential signal lines. The main focus is on the reduction of twisted-pair cables. Furthermore, the process presented here allows to take into account cables with wires that are situated quite close to each other. The procedure is based on a new approach to calculate the geometry of the simplified cable and uses the fact that the line parameters do not uniquely correspond to a certain geometry. For this reason, an optimization algorithm is applied

Predicting the Next Best View for 3D Mesh Refinement

3D reconstruction is a core task in many applications such as robot navigation or sites inspections. Finding the best poses to capture part of the scene is one of the most challenging topic that goes under the name of Next Best View. Recently, many volumetric methods have been proposed; they choose the Next Best View by reasoning over a 3D voxelized space and by finding which pose minimizes the uncertainty decoded into the voxels. Such methods are effective, but they do not scale well since the underlaying representation requires a huge amount of memory. In this paper we propose a novel mesh-based approach which focuses on the worst reconstructed region of the environment mesh. We define a photo-consistent index to evaluate the 3D mesh accuracy, and an energy function over the worst regions of the mesh which takes into account the mutual parallax with respect to the previous cameras, the angle of incidence of the viewing ray to the surface and the visibility of the region. We test our approach over a well known dataset and achieve state-of-the-art results.Comment: 13 pages, 5 figures, to be published in IAS-1