1,700 research outputs found

    Clarke subgradients of stratifiable functions

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    We establish the following result: if the graph of a (nonsmooth) real-extended-valued function f:RnR{+}f:\mathbb{R}^{n}\to \mathbb{R}\cup\{+\infty\} is closed and admits a Whitney stratification, then the norm of the gradient of ff at xdomfx\in{dom}f relative to the stratum containing xx bounds from below all norms of Clarke subgradients of ff at xx. As a consequence, we obtain some Morse-Sard type theorems as well as a nonsmooth Kurdyka-\L ojasiewicz inequality for functions definable in an arbitrary o-minimal structure

    Mechanical properties of Pt monatomic chains

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    The mechanical properties of platinum monatomic chains were investigated by simultaneous measurement of an effective stiffness and the conductance using our newly developed mechanically controllable break junction (MCBJ) technique with a tuning fork as a force sensor. When stretching a monatomic contact (two-atom chain), the stiffness and conductance increases at the early stage of stretching and then decreases just before breaking, which is attributed to a transition of the chain configuration and bond weakening. A statistical analysis was made to investigate the mechanical properties of monatomic chains. The average stiffness shows minima at the peak positions of the length-histogram. From this result we conclude that the peaks in the length-histogram are a measure of the number of atoms in the chains, and that the chains break from a strained state. Additionally, we find that the smaller the initial stiffness of the chain is, the longer the chain becomes. This shows that softer chains can be stretched longer.Comment: 6 pages, 5 figure

    The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors

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    The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors is reported. After treatment of the devices by annealing processes in forming gas atmosphere at different temperatures and for different times, distinct and reproducible changes of their resistance and capacitance values were found. According to the temperature regime, we observed different behaviors as regards the resistance changes, namely the tendency to decrease the resistance by annealing at T = 200 degree C, but to increase the resistance by annealing at T = 400 degree C. We attribute this behavior to changes in the aluminum oxide barriers of the tunnel junctions. The good reproducibility of these effects with respect to the changes observed allows the proper annealing treatment to be used for post-process tuning of tunnel junction parameters. Also, the influence of the annealing treatment on the noise properties of the transistors at low frequency was investigated. In no case did the noise figures in the 1/f-regime show significant changes.Comment: 6 pages, 7 eps-figure

    Self-Consistent MHD Modeling of a Coronal Mass Ejection, Coronal Dimming, and a Giant Cusp-Shaped Arcade Formation

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    We performed magnetohydrodynamic simulation of coronal mass ejections (CMEs) and associated giant arcade formations, and the results suggested new interpretations of observations of CMEs. We performed two cases of the simulation: with and without heat conduction. Comparing between the results of the two cases, we found that reconnection rate in the conductive case is a little higher than that in the adiabatic case and the temperature of the loop top is consistent with the theoretical value predicted by the Yokoyama-Shibata scaling law. The dynamical properties such as velocity and magnetic fields are similar in the two cases, whereas thermal properties such as temperature and density are very different.In both cases, slow shocks associated with magnetic reconnectionpropagate from the reconnection region along the magnetic field lines around the flux rope, and the shock fronts form spiral patterns. Just outside the slow shocks, the plasma density decreased a great deal. The soft X-ray images synthesized from the numerical results are compared with the soft X-ray images of a giant arcade observed with the Soft X-ray Telescope aboard {\it Yohkoh}, it is confirmed that the effect of heat conduction is significant for the detailed comparison between simulation and observation. The comparison between synthesized and observed soft X-ray images provides new interpretations of various features associated with CMEs and giant arcades.Comment: 39 pages, 18 figures. Accepted for publication in the Astrophysical Journal. The PDF file with high resplution figures can be downloaded from http://www.kwasan.kyoto-u.ac.jp/~shiota/study/ApJ62426.preprint.pdf

    A Research of Basic Energy Reduction Approach Using PV Power Smoothing EV Storage System and LED Simple Circuit for Create Green Innovation

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    In general, Light Emitting Diode (LED) is low power consumption, and Photovoltaic (PV) generation of Renewable Energy is effective as energy creation. However, LED applications have a problem of LED Circuit Radiation Noise and PV generation applications have a problem of the Output Power fluctuation in the weather. This paper will be proposed as an especial approach of the energy reduction to contribute to the realization of the low carbon society in the world. In this research, without using Common Mode Choke (CMC) Noise Cut filter, the Radiation Noise reduction result in World Standard Guideline by the selection of a simple circuit of the most effective LED lighting of various power reduction methods have been confirmed by the examinations. Additionally, in order to investigate the lighting specification, the simple Lighting evaluation equipment has been developed. As an energy fluctuation reduction research, the new control system of the PV fluctuation electric power using EV battery charge-discharge electric power that is able to be easily connected with a Power Conditioning System (PCS) input is proposed. A simulation result using the actual PV generator output data is provided to confirm the effectiveness of Simple Moving Average (SMA) method. Moreover, the outline of a new large area monitoring control GIS system for the implementation of the PV generator power prognostication without the weather estimation is introduced.九工大・マレーシアプトラ大学国際合同シンポジウム: International Symposium on Applied Engineering and Sciences (SAES), September 30- October 1, 2013, Universiti Putra Malaysia, Malaysi
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