Israel-Wilson metrics are solutions to the Einstein-Maxwell equations in the Lorentzian regime. We prove theorems showing that these metrics can consistently be analytically continued into the Euclidean sector where they can be made to satisfy asymptotically flat or asymptotically Euclidean boundary conditions. We show these spacetimes can have complicated topologies and suggest they provide a possible model for the gravitational vacuum. We note that these metrics admit a gauge covariant constant supergravity transformation.

Comparisons of exha-cellular fluid (w) volume estimates made by isotope dilution and electrical impedance techniques have been made in a group of 16 children. For each patient an estimate of BCF volume (V,) was obtained from measurements of the blood clearance of 99Tc"-diethylene triamine penta-acetate @PI A) which was compared with WO estimates (V,l and Vi) of FCF volume obtained from measurements of the whole-body electrical impedance at 50 frequencies in the range 1 kkh to 1.348 MHz and a third estimate Vh based on patient heighr L, alone. The observed frequency response of the impedance measurements was fined to a thee. element equivalent-circuit model of whole-body impedance and gave a value of the ECF resistance R. V i 1 was obtained from Vi, = 4 ( L z / R ) + b. Viz was given by C ( W ? L~/ R )~~~ where W is the patient weight and Vh was given by dLZ + e. The constants (1, b. e, d, e were determined by comparison with V, and were equal to 0.335 IClm-' (standard error = 0.01 0.42 1 (0.25 I), 0.33 1 (~2~k g -~m -~)~i~ 0.007 1 (s2'kg-1m-4)1n, 4.92 I m-' (2.8 x 1m-l). 0.13 1 (0.41 1). respectively. 91, Viz. Vh were linearly correlated with V, 0' = 0.98, 0.99. 0.95, respectively, p < 0.001), and upper and lower levels of agreement were given by 50.95 1 (V,and Vi), 1.44 1 and -1.12 1 (V, and Viz), k1.5 1 (V, and Vh), respectively. Thus inclusion of the impedance data accounted for gmter volume variation. but differences between the techniques were not signficant (paired t-test and Man"-Whimey analysis) suggesting that more accurate and detailed measurements are quired.

A new write shift compensation method is proposed in this paper. The method is suitable for an optical disk system which adopts partial response maximum likelihood (PRML) detection, and it can optimize adaptive controlled writing pulses even under severe inter-symbol interference (ISI) conditions to reduce detection errors. This advantage is attributable to the use of the Euclidean distance as the estimation index of the mark edge shift error. The effect is confirmed by the experimental results for blue laser systems.

No abstract

No abstract