in this note we characterize polynomial numerical hulls of matrices $a in m_n$ such that$a^2$ is hermitian. also, we consider normal matrices $a in m_n$ whose $k^{th}$ power are semidefinite. for such matriceswe show that $v^k(a)=sigma(a)$.

let a and b be n × m matrices. the matrix b is said to be g-row majorized (respectively g-column majorized) by a, if every row (respectively column) of b, is g-majorized by the corresponding row (respectively column) of a. in this paper all kinds of g-majorization are studied on mn,m, and the possible structure of their linear preservers will be found. also all linear operators t : mn,m ---> mn...

begin{abstract} The relations between the spectrum of the matrix $Q+R$ and the spectra of the matrices $(gamma + delta)Q+(alpha + beta)R-QR-RQ$, $QR-RQ$, $alpha beta R-QRQ$, $alpha RQR-(QR)^{2}$, and $beta R-QR$ have been given on condition that the matrix $Q+R$ is diagonalizable, where $Q$, $R$ are ${alpha, beta}$-quadratic matrix and ${gamma, delta}$-quadratic matrix, respectively, of ord...

Using coherent x-ray speckle metrology, we have measured the influence of disorder on major loop return point memory (RPM) and complementary point memory (CPM) for a series of perpendicular anisotropy Co/Pt multilayer films. In the low disorder limit, the domain structures show no memory with field cycling--no RPM and no CPM. With increasing disorder, we observe the onset and the saturation of ...

Previous studies have sought to improve cycling performance by altering various aspects of the pedaling motion using novel crank-pedal mechanisms and non-circular chainrings. However, most designs have been based on empirical data and very few have provided significant improvements in cycling performance. The purpose of this study was to use a theoretical framework that included a detailed musc...

Sao Paulo Med J. 2007;125(2):85-90. O R IG IN A L A R T IC L E Oscar Tadashi Matsuoka

15 Greenland S. Application of stratified analysis methods. In: Rothman KJ, Greenland S (eds). Modern Epidemiology. 2nd Edn. Philadelphia: Lippincott-Raven, 1997, pp. 281–300. 16 Bartley M, Power C, Blane D, Davey Smith G, Shipley M. Birth weight and later socioeconomic disadvantage: evidence from the 1958 British cohort study. BMJ 1994;309:1475–78. 17 Burström B, Whitehead M, Lindholm C, Dider...

This paper proposes a new non‐magnetic motor with a rotor rotated by using the resonance en‐ ergy of a bimorph cantilever beam excited by electrostatic force. The use of flexible material en‐ ables conversion of translational vibration to rotary movement in one direction. Basic character‐ istics of a prototype motor with two bimorph cantilever beams, such as rotational speed, output torque, and...