1,411 research outputs found
Symbolic Tensor Calculus -- Functional and Dynamic Approach
In this paper, we briefly discuss the dynamic and functional approach to
computer symbolic tensor analysis. The ccgrg package for Wolfram
Language/Mathematica is used to illustrate this approach. Some examples of
applications are attached
Wheelchair-based game design for older adults
Few leisure activities are accessible to institutionalized older adults using wheelchairs; in consequence, they experience lower levels of perceived health than able-bodied peers. Video games have been shown to be an engaging leisure activity for older adults. In our work, we address the design of wheelchair-accessible motion-based games. We present KINECTWheels, a toolkit designed to integrate wheelchair movements into motion-based games, and Cupcake Heaven, a wheelchair-based video game designed for older adults using wheelchairs. Results of two studies show that KINECTWheels can be applied to make motion-based games wheelchair-accessible, and that wheelchair-based games engage older adults. Through the application of the wheelchair as an enabling technology in play, our work has the potential of encouraging older adults to develop a positive relationship with their wheelchair. Copyright 2013 ACM
The utilization of selection after 100-days lactation in forming a high productive Red and White herd
International audienc
Recommended from our members
Connection between sea surface anomalies and atmospheric quasi-stationary waves
Large scale, quasi-stationary atmospheric waves (QSWs) are known to be strongly connected with extreme events and general weather conditions. Yet, despite their importance, there is still a lack of understanding about what drives variability in QSW. This study is a step towards this goal, and identifies three statistically significant connections between QSWs and sea surface anomalies (temperature and ice cover) by applying a maximum covariance analysis technique to reanalysis data (1979-2015). The two most dominant connections are linked to the El Ni\~no Southern Oscillation and the North Atlantic Oscillation. They confirm the expected relationship between QSWs and anomalous surface conditions in the tropical Pacific and the North Atlantic, but they cannot be used to infer a driving mechanism or predictability from the sea surface temperature or the sea ice cover to the QSW. The third connection, in contrast, occurs between late winter to early spring Atlantic sea ice concentrations and anomalous QSW patterns in the following late summer to early autumn. This new finding offers a pathway for possible long term predictability of late summer QSW occurrence
Effect of Sb and MnO2-Doping on Phase Transitions, Crystal Structure, Thermal, Dielectric, Ferroelectric and Piezoelectric Properties of Na0.5K0.5NbO3 Ceramics
Lead-free ceramics of Na0.5K0.5Nb1-xSbxO3 (NKNS) and Na0.5K0.5Nb1-xSbxO3 + 0.5 mol%MnO2 (NKNS + 0.5 mol%MnO2)
(0 < x < 0.06) ceramics were prepared by a conventional solid-state hot pressing method. The ceramics possess a single-phase
perovskite structure with orthorhombic symmetry. Microstructural examination revealed that Mn doping of NKNS leads to improvement
of densification. The cubic-tetragonal and tetragonal-orthorhombic phase transitions of NKNS shifted to higher and
lower temperature, respectively after introduction of Mn ion. Besides, ferroelectric and piezoelectric properties were improved.
The results were discussed in term of difference in both ionic size and electronegativity of Nb5+ and Sb5+ and improvement of
densification after Mn ion doping
Recommended from our members
Quasi-stationary waves and their impact on European weather and extreme events
Large-scale, quasi-stationary atmospheric waves (QSWs) have long been known to be associated with weather extremes such as the European heatwave in 2003. There is much debate in the scientific literature as to whether QSW activity may increase under a changing climate, providing a strong motivation for developing a better understanding of the behaviour and drivers of QSWs. This paper presents the first steps in this regard: the development of a robust objective method for a simple identification and characterisation of these waves. A clear connection between QSWs and European weather and extreme events is confirmed for all seasons, indicating that blocking anticyclones are often part of a broader scale wave pattern.
Investigation of the QSW climatology in the Northern Hemisphere reveals that wave activity is typically strongest in midlatitudes, particularly at the exit of the Atlantic and Pacific storm track with weaker intensities in summer. In general, the structure of individual QSW events tends to follow the climatological pattern, except in winter where the strongest and most persistent QSWs are typically shifted polewards, indicating a distinct evolution of the ’strongest’ QSW events. Modes of inter-annual variability are calculated to better understand their importance and connection to European temperatures and to identify relevant QSW patterns. This analysis highlights that European winter temperatures are strongly associated with the meridional location of QSW activity whereas warm European summer temperatures are associated with increases in the overall intensity of midlatitude QSW activity.
QSWs are shown to be strongly connected to commonly used indices to describe the large scale atmospheric circulation (NAO, AO, Ni˜no 3.4, PNA) but offer a more direct link to understanding their impact on regional weather events. It is therefore hoped that objective identification of QSWs will provide a useful new viewpoint for interpreting large-scale weather alongside more traditional measures and metrics
Interpreting myocardial perfusion scintigraphy using single-photon emission computed tomography. Part 1
This article discusses the protocol for myocardial perfusion scintigraphy performed with single-photon emission computed tomography (SPECT). Indications for SPECT are listed with consideration given to the results of the increasingly more common angio-CT examinations of the coronary arteries (multislice computed tomography). The paper also presents basic information about interpreting the results, including the scores of left ventricle myocardial perfusion using the 17-segment polar map, and explains the concept of total perfusion deficit
Histological Remission during Corticosteroid Therapy of Overlapping Nonalcoholic Steatohepatitis and Autoimmune Hepatitis: Case Report and Literature Review
Concurrence of nonalcoholic steatohepatitis (NASH) with autoimmune hepatitis (AIH) is a rare condition that is challenging to diagnosis, due to the relatively high prevalence of autoantibodies in NASH. It is also difficult to determine the most effective treatment as corticosteroids are likely to worsen NASH despite being effective in the treatment of AIH. In this case report, we present a female diagnosed with NASH-AIH overlap with accompanying diabetes mellitus, who successfully achieved normalization of serum alanine aminotransferase levels following prednisolone therapy and weight loss. A follow-up liver biopsy performed 40 months after the initial diagnosis showed only minimal inflammatory infiltrates in the portal area without any NASH histology. Resolution of NASH, in conjunction with a reduction in hepatic fibrosis, might suggest that prednisolone itself does not aggravate steatohepatitis, but rather prevents disease progression. Appropriate immunosuppressive treatment may therefore be an important component of the optimum therapy for NASH-AIH overlap
Tip-surface forces, amplitude, and energy dissipation in amplitude-modulation (tapping mode) force microscopy
Amplitude-modulation (tapping mode) atomic force microscopy is a technique for high resolution imaging of a wide variety of surfaces in air and liquid environments. Here by using the virial theorem and energy conservation principles we have derived analytical relationships between the oscillation amplitude, phase shift, and average tip-surface forces. We find that the average value of the interaction force and oscillation and the average power dissipated by the tip-surface interaction are the quantities that control the amplitude reduction. The agreement obtained between analytical and numerical results supports the analytical method.This work has been supported by the Dirección General de Investigación Científica y Técnica (PB98-0471) and the
European Union (BICEPS, BIO4-CT-2112). A. S. P. acknowledges financial support from the Comunidad Autónoma de Madrid.Peer reviewe
Design of a robotic hand with a biologically-inspired parallel actuation system for prosthetic applications
Trabajo presentado al 34th Annual Mechanisms and Robotics Conference celebrado en Quebec del 15 al 18 de agosto de 2010.This paper presents the design of a robotic hand for prosthetic applications. The main characteristic of this robotic hand is its biologically-inspired parallel actuation system, which is based on the behavior/strength space of the Flexor Digitorum Profundus (FDP) and the Flexor Digitorum Superficialis (FDS) muscles. The design separates the strength space of the FDS and FDP muscles into a lighter strength region where finer manipulation and general approach tasks are executed, and a higher strength region where the more robust grasps are achieved. Two parallel actuator types and kinematic structures are designed to complement the requirements of both strength space regions.This research was performed under an award/contract from Telemedicine Advanced Technology Research Center (TATRC), of the U.S. Army Medical Research and Materiel Command
(USAMRMC) of the U.S. Department of Defense.Peer Reviewe
- …