5,763 research outputs found

    User orientation

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    This chapter discusses the evolution of the user-oriented approaches in the design process in the built environment. Along with the 4 research dimensions of the research program in the USO-Built Graduate School (functional, intentional, structural, and instrumental), the present chapter looks at 3 stages of the user approaches in the architectural, building and urban disciplines: (1) a standardised or functional, approach; (2) a phenomenological, or intentional, approach; and (3) postmodern, or structural and instrumental, approach. The chapter concludes that the active relationship between the 4 dimensions is essential in the research and design of the future built environment. What is required now is to consider social practices

    Composite and elementary natures of a1(1260) meson

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    We develop a practical method to analyze the mixing structure of hadrons consisting of two components of quark-composite and hadronic composite. As an example we investigate the properties of the axial vector meson a1(1260) and discuss its mixing properties quantitatively. We also make reference to the large Nc procedure and its limitation for the classification of such a mixed state.Comment: 13 pages, 4 figure

    Saari's homographic conjecture for planar equal-mass three-body problem under a strong force potential

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    Donald Saari conjectured that the NN-body motion with constant configurational measure is a motion with fixed shape. Here, the configurational measure μ\mu is a scale invariant product of the moment of inertia I=∑kmk∣qk∣2I=\sum_k m_k |q_k|^2 and the potential function U=∑i<jmimj/∣qi−qj∣αU=\sum_{i<j} m_i m_j/|q_i-q_j|^\alpha, α>0\alpha >0. Namely, μ=Iα/2U\mu = I^{\alpha/2}U. We will show that this conjecture is true for planar equal-mass three-body problem under the strong force potential ∑i<j1/∣qi−qj∣2\sum_{i<j} 1/|q_i-q_j|^2

    Choreographic Three Bodies on the Lemniscate

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    We show that choreographic three bodies {x(t), x(t+T/3), x(t-T/3)} of period T on the lemniscate, x(t) = (x-hat+y-hat cn(t))sn(t)/(1+cn^2(t)) parameterized by the Jacobi's elliptic functions sn and cn with modulus k^2 = (2+sqrt{3})/4, conserve the center of mass and the angular momentum, where x-hat and y-hat are the orthogonal unit vectors defining the plane of the motion. They also conserve the moment of inertia, the kinetic energy, the sum of square of the curvature, the product of distance and the sum of square of distance between bodies. We find that they satisfy the equation of motion under the potential energy sum_{i<j}(1/2 ln r_{ij} -sqrt{3}/24 r_{ij}^2) or sum_{i<j}1/2 ln r_{ij} -sum_{i}sqrt{3}/8 r_{i}^2, where r_{ij} the distance between the body i and j, and r_{i} the distance from the origin. The first term of the potential energies is the Newton's gravity in two dimensions but the second term is the mutual repulsive force or a repulsive force from the origin, respectively. Then, geometric construction methods for the positions of the choreographic three bodies are given

    A synthetic Escherichia coli predator–prey ecosystem

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    We have constructed a synthetic ecosystem consisting of two Escherichia coli populations, which communicate bi-directionally through quorum sensing and regulate each other's gene expression and survival via engineered gene circuits. Our synthetic ecosystem resembles canonical predator–prey systems in terms of logic and dynamics. The predator cells kill the prey by inducing expression of a killer protein in the prey, while the prey rescue the predators by eliciting expression of an antidote protein in the predator. Extinction, coexistence and oscillatory dynamics of the predator and prey populations are possible depending on the operating conditions as experimentally validated by long-term culturing of the system in microchemostats. A simple mathematical model is developed to capture these system dynamics. Coherent interplay between experiments and mathematical analysis enables exploration of the dynamics of interacting populations in a predictable manner

    Gallium Nitride Super-Luminescent Light Emitting Diodes for Optical Coherence Tomography Applications

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    The role of biasing of absorber sections in multi-contact GaN ~400nm SLEDs is discussed. We go on to assess such devices for OCT applications. Analysis of the SLED emission spectrum allows an axial resolution of 6.0μm to be deduced in OCT applications

    Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms

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    Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance

    Krylov Subspace Method for Molecular Dynamics Simulation based on Large-Scale Electronic Structure Theory

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    For large scale electronic structure calculation, the Krylov subspace method is introduced to calculate the one-body density matrix instead of the eigenstates of given Hamiltonian. This method provides an efficient way to extract the essential character of the Hamiltonian within a limited number of basis set. Its validation is confirmed by the convergence property of the density matrix within the subspace. The following quantities are calculated; energy, force, density of states, and energy spectrum. Molecular dynamics simulation of Si(001) surface reconstruction is examined as an example, and the results reproduce the mechanism of asymmetric surface dimer.Comment: 7 pages, 3 figures; corrected typos; to be published in Journal of the Phys. Soc. of Japa

    Efficient Recursion Method for Inverting Overlap Matrix

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    A new O(N) algorithm based on a recursion method, in which the computational effort is proportional to the number of atoms N, is presented for calculating the inverse of an overlap matrix which is needed in electronic structure calculations with the the non-orthogonal localized basis set. This efficient inverting method can be incorporated in several O(N) methods for diagonalization of a generalized secular equation. By studying convergence properties of the 1-norm of an error matrix for diamond and fcc Al, this method is compared to three other O(N) methods (the divide method, Taylor expansion method, and Hotelling's method) with regard to computational accuracy and efficiency within the density functional theory. The test calculations show that the new method is about one-hundred times faster than the divide method in computational time to achieve the same convergence for both diamond and fcc Al, while the Taylor expansion method and Hotelling's method suffer from numerical instabilities in most cases.Comment: 17 pages and 4 figure
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