21,866 research outputs found

    Efficacy of alternative seating on attention, in-seat behavior, and occupational performance in children with Attention Deficit Hyperactivity Disorder

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    Currently, there is one systematic review conducted by Gochenour and Poskey7 that synthesize current research evidence regarding alternative seating for students with attention difficulties. A limitation of this review, as noted by the authors, is a lack of a consistent definition of attention difficulty in the studies they included. A systematic review focused on a specific, well-defined diagnosis will better contribute to practice recommendations since these recommendations will be tailored to a clear and comprehensive understanding of the child’s attentional and occupational challenges. The review also included studies of children with autism spectrum disorder (ASD).7 While those with ASD may also have difficulties with attention, in-seat behavior and occupational performance, the underlying mechanism yielding these symptoms may be different than in children with ADHD. Thus, alternative seating may not work in the same way for children with ASD as it would for children with ADHD.7 Thus, a systematic review is needed to examine the evidence from all current studies regarding alternative seating on improving attention, in-seat behavior and occupational performance in students with ADHD to increase evidence-based practice in the field of occupational therapy

    Elliptic flow of ϕ\phi meson and strange quark collectivity at RHIC

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    Based on A Multi-Phase Transport (AMPT) model, we have studied the elliptic flow v2v_{2} of ϕ\phi mesons from reconstructed K+KK^{+}K^{-} decay channel at the top Relativistic Heavy Ion Collider energy at Brookhaven National Laboratory. The dependences of v2v_{2} on transverse momentum pTp_T and collision centrality are presented and the rescattering effect of ϕ\phi mesons in the hadronic phase is also investigated. The results show that experimental measurement of v2v_{2} for ϕ\phi mesons can retain the early collision information before ϕ\phi decays and that the ϕ\phi v2v_2 value obeys the constituent quark number scaling which has been observed for other mesons and baryons. Our study indicates that the ϕ\phi v2v_2 mostly reflects partonic level collectivity developed during the early stage of the nucleus-nucleus collision and the strange and light up/down quarks have developed similar angular anistropy properties at the hadronization.Comment: 5 pages and 5 figures; accepted by Physical Review

    Fetching marked items from an unsorted database in NMR ensemble computing

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    Searching a marked item or several marked items from an unsorted database is a very difficult mathematical problem. Using classical computer, it requires O(N=2n)O(N=2^n) steps to find the target. Using a quantum computer, Grover's algorithm uses O(N=2n)O(\sqrt{N=2^n}) steps. In NMR ensemble computing, Brushweiler's algorithm uses logN\log N steps. In this Letter, we propose an algorithm that fetches marked items in an unsorted database directly. It requires only a single query. It can find a single marked item or multiple number of items.Comment: 4 pages and 1 figur

    Time-varying systems identification using continuous wavelet analysis of free decay response signals

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    This paper proposes a time-varying approach used for identification of time-varying systems and presents a simulation example of a simple vibration system with time-varying mass, stiffness and damping characteristics, which is a five-storey shear-beam building model. Free decay acceleration response signals are analyzed to reveal time-varying nature of the system. Wavelet analysis is used for system identification. The method is based on a recently developed direct identification algorithm. Numerical results confirm that the proposed method is accurate and effective in identification of the time-varying system

    Instantaneous frequency identification of a time varying structure using wavelet-based state-space method

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    This paper presents a method to identify the instantaneous frequency of the time varying structures based on wavelet and state space methods by using free and forced vibration response data. Firstly, the second-order vibration differential equations are rewritten as the first-order state equations using state space theory. Secondly, both excitation and response signals are projected by the Daubechies wavelet scaling functions. Thus, the first-order state equations are transformed into linear algebraic equations using the orthogonality of the scaling functions. Lastly, the equivalent time varying state space system matrices of time varying structure are extracted directly by solving the linear equations. The instantaneous frequencies are determined via eigenvalue decomposition of the state space system matrices. The proposed identification algorithm is investigated with a four degrees-of-freedom spring-mass-damper model. Numerical simulations demonstrate that the proposed method is robust and effective for identification of the abruptly, smoothly and periodically changing instantaneous frequencies of time varying structures

    A knowledge-based ideation approach for bio-inspired design

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    Bio-inspired design (BID) involves generating innovative ideas for engineering design by drawing inspiration from natural biological phenomena and systems, using a form of design-by-analogy. Despite its many successes, BID approaches encounter research challenges including unstructured data and existing models that hinder comprehension and processing, limited focus on finding biological knowledge compared to defined problems, and insufficient guidance of the ideation process with algorithms. This paper proposes a knowledge-based approach to address the challenges. The approach involves transforming unstructured data into structured knowledge, including information about natural sources, their benefits, and applications. The structured knowledge is then used to construct a semantic network, enabling designers to retrieve information for BID in two ways. Furthermore, a three-step ideation method is developed to encourage divergent thinking and explore additional potential solutions by drawing inspiration and utilizing knowledge. The knowledge-based BID approach is implemented as a tool and design cases are conducted to illustrate the process of applying this tool for BID
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