2,287 research outputs found

    Seismic cycles, size of the largest events, and the avalanche size distribution in a model of seismicity

    Get PDF
    We address several questions on the behavior of a numerical model recently introduced to study seismic phenomena, that includes relaxation in the plates as a key ingredient. We make an analysis of the scaling of the largest events with system size, and show that when parameters are appropriately interpreted, the typical size of the largest events scale as the system size, without the necessity to tune any parameter. Secondly, we show that the temporal activity in the model is inherently non-stationary, and obtain from here justification and support for the concept of a "seismic cycle" in the temporal evolution of seismic activity. Finally, we ask for the reasons that make the model display a realistic value of the decaying exponent bb in the Gutenberg-Richter law for the avalanche size distribution. We explain why relaxation induces a systematic increase of bb from its value b≃0.4b\simeq 0.4 observed in the absence of relaxation. However, we have not been able to justify the actual robustness of the model in displaying a consistent bb value around the experimentally observed value b≃1b\simeq 1.Comment: 11 pages, 10 figure

    Highway Service That Satisfies

    Get PDF

    Educating teachers about human rights: building a rights based culture in Australian schools

    Full text link
    © 2016 Australian Teacher Education Association. A well-educated active citizenry is the primary aim of our education systems. An essential component of a well-educated citizenry in a civil society is its understanding of the value of human rights and what it means to live with dignity in a community, where rights and freedoms are protected. This paper uses evidence from international and national reports and programmes to argue that HRE should be an essential component of the curriculum in Australian schools. It draws on data from the first national cross-sectoral Australian study investigating the place of HRE in the school curriculum. There is a need for both pre-service and in-service teachers to have focused professional training, in order to better engage students to be critically aware of the importance of developing a human rights culture within a school; also, to adopt a transformative “whole school” approach linked to local, national, and global communities

    Human Rights and History Education: An australian study

    Get PDF
    The place of education for and about human rights within the school curriculum remains contested and this paper reports on the first national crosssectoral investigation of its place in Australian curricula and more specifically in national and state History curriculum documents. Opportunities for the inclusion of human rights based studies were examined across school learning stages, taking into account explicit and implicit, compulsory or elective, as well as curricular and extra-curricular dimensions. Given the continued importance of History as a learning area, there is a need to strengthen the available explicit and mandatory opportunities for students to learn about human rights issues, working closely with key teacher associations, non-government agencies and supportive networks, drawing on available educational technologies

    The effects of early rheumatoid arthritis on dominant and non-dominant hand impairment and function

    Get PDF
    Rheumatoid arthritis (RA) is defined as a symmetrical disease yet there is evidence that hand joint damage sustained in RA is related to use, and hand dominance could affect the degree of structural impairment evident in the wrist and hand. This exploratory research aimed to examine the relationship of dominant and non-dominant wrist and hand joint impairment and function in an early rheumatoid population. A multi-centre cohort study was conducted, recruiting consenting patients with early rheumatoid arthritis from eight outpatient occupational therapy departments. Wrist and hand joint impairment and function were assessed by measuring joint pain and swelling, range of motion and joint deviation, handgrip and hand dexterity. The results demonstrated that the non-dominant hand showed less pathological structural and functional involvement than the dominant hand in all but one outcome measure. These differences reached statistical significance between dominant and non-dominant hands on active range of motion in the wrist and some digits. Dominant hand structural impairment and dysfunction in this early RA sample was consistently greater than the non-dominant hand and bilateral handgrip ratio did not reflect healthy values for norms. Individuals with early RA showed a greater level of impairment in their dominant hands

    Fractal Dimensionof the El Salvador Earthquake (2001) time Series

    Full text link
    We have estimated multifractal spectrum of the El Salvador earthquake signal recorded at different locations.Comment: multifractal analysi

    Functional Electrical Stimulation mediated by Iterative Learning Control and 3D robotics reduces motor impairment in chronic stroke

    Get PDF
    Background: Novel stroke rehabilitation techniques that employ electrical stimulation (ES) and robotic technologies are effective in reducing upper limb impairments. ES is most effective when it is applied to support the patients’ voluntary effort; however, current systems fail to fully exploit this connection. This study builds on previous work using advanced ES controllers, and aims to investigate the feasibility of Stimulation Assistance through Iterative Learning (SAIL), a novel upper limb stroke rehabilitation system which utilises robotic support, ES, and voluntary effort. Methods: Five hemiparetic, chronic stroke participants with impaired upper limb function attended 18, 1 hour intervention sessions. Participants completed virtual reality tracking tasks whereby they moved their impaired arm to follow a slowly moving sphere along a specified trajectory. To do this, the participants’ arm was supported by a robot. ES, mediated by advanced iterative learning control (ILC) algorithms, was applied to the triceps and anterior deltoid muscles. Each movement was repeated 6 times and ILC adjusted the amount of stimulation applied on each trial to improve accuracy and maximise voluntary effort. Participants completed clinical assessments (Fugl-Meyer, Action Research Arm Test) at baseline and post-intervention, as well as unassisted tracking tasks at the beginning and end of each intervention session. Data were analysed using t-tests and linear regression. Results: From baseline to post-intervention, Fugl-Meyer scores improved, assisted and unassisted tracking performance improved, and the amount of ES required to assist tracking reduced. Conclusions: The concept of minimising support from ES using ILC algorithms was demonstrated. The positive results are promising with respect to reducing upper limb impairments following stroke, however, a larger study is required to confirm this

    Sequential Composition of Dynamically Dexterous Robot Behaviors

    Get PDF
    We report on our efforts to develop a sequential robot controller-composition technique in the context of dexterous “batting” maneuvers. A robot with a flat paddle is required to strike repeatedly at a thrown ball until the ball is brought to rest on the paddle at a specified location. The robot’s reachable workspace is blocked by an obstacle that disconnects the free space formed when the ball and paddle remain in contact, forcing the machine to “let go” for a time to bring the ball to the desired state. The controller compositions we create guarantee that a ball introduced in the “safe workspace” remains there and is ultimately brought to the goal. We report on experimental results from an implementation of these formal composition methods, and present descriptive statistics characterizing the experiments.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67990/2/10.1177_02783649922066385.pd

    Toward A Systems Theory for the Composition of Dynamically Dexterous Robot Behaviors

    Get PDF
    We report on our efforts to develop robot controller composition techniques in the context of dexterous “batting” maneuvers. A robot with a flat paddle is required to strike repeatedly at a falling ball until it is brought to zero velocity at a a specified position. The robot’s workspace is cluttered with obstacles that disconnect the freespace formed when the ball and paddle remain in contact - the machine is forced to “let go” for a time in order to bring the ball to the desired state. The controller compositions that we create will guarantee that a ball introduced in the “safe workspace” remains there and is ultimately brought to the goal. We believe that the developing systems discipline described here may be extended to build a variety of useful dexterous machines that are similarly single-minded in their pursuit of the user’s goal behavior and ability to surmount unanticipated perturbations along the way. For more information: Kod*La
    • 

    corecore