Fabrication and characteristics of high-speed implant-confined index-guided lateral-current 850-nm vertical cavity surface-emitting lasers

Process technology of high-speed implant-apertured index-guide lateral-current-injection top dielectric-mirror quantum-well 850-nm vertical cavity surface-emitting lasers (VCSELs) has been developed. Oxygen and helium implantation for aperture definition and extrinsic capacitance reduction, dielectric mirror formation, p- and n-ohmic contact formation, VCSEL resistance, and thermal analysis were investigated. Employing this technology, GaAs/AlGaAs-based 850-nm VCSELs with small signal modulation bandwidths up to 11.5 Gb/s and an eye diagram generated at 12 Gb/s by a pseudorandom bit sequence of 2/sup 31/-1 were achieved. The bit-error rates were below 10/sup -13/. The threshold current is as low as 0.8 mA for 7-/spl mu/m-diameter current apertures and typical slope efficiencies of 0.45-0.5 mA/mW were obtained.     

Group therapy for adult women survivors of child sexual abuse: Differentiation of completers versus dropouts.

Examined intake profiles of 54 depressed women survivors of child sexual abuse presenting for a specialized group therapy program at a community mental health center. The 32 therapy completers were compared with the 22 dropouts. Both groups possessed extensive and severe childhood and adult abuse histories. Both were extremely socially disadvantaged and clinically impaired as measured on the Millon Clinical Multiaxial Inventory (MCMI). Dropouts were more likely to have been battered as children and to have been sexually abused only within the family. Completers were more likely to have been multiply offended both by intrafamilial and extrafamilial perpetrators. The groups differed in terms of marital status and extent of economic dependence on spouse. Dropouts appeared to be more actively enmeshed in the abuse cycle at the time of therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation three-dimensional motion of rigid objects from noisyobservations

An estimate is made of the motion of a rigid body from two noisy 2-D perspective projections using the least-squares method and the algebra of R.Y. Tsai and T.S. Huang (1984). The accuracy of the estimated motion parameters is influenced by the position of the features of the object used in the calculation. Four test variables are derived that indicate how the accuracy is affected, and they are used for discarding inaccurate estimates. Monte Carlo tests demonstrate the obtained accuracy     

Estimating block selectivities for physical database design

Access path deployment is a critical issue in physical database design. Access paths typically include a clustered index as the primary access path and a set of secondary indexes as auxiliary access paths. To deploy the right access paths requires an effective algorithm and accurate estimation of the parameters used by the algorithm. One parameter central to any index-selection algorithm is the block selectivity of a query. Existing methods for estimating block selectivities are limited by restrictive assumptions. Furthermore, most existing methods produce estimates useful for aiding the selection of secondary indexes only. Little research has been done in the area of estimating block selectivities for supporting the selection of the clustered index. The paper presents a set of methods that do not depend on any specific assumption, produce accurate estimates, and can be used to aid in selecting the clustered index as well as secondary indexes     

Very high-order microring resonator filters for WDM applications

High-order microring resonators having from 1 to 11 coupled cavities are demonstrated. These filters exhibit low loss, flat tops, and out-of-band rejection ratios that can exceed 80 dB. They achieve performance that is suitable for commercial applications.     

NMR Studies of Diffusion-Coherence Phenomena in Red Cell Suspensions: Current Status

Pulsed field-gradient spin-echo (PGSE) nuclear magnetic resonance (NMR) diffusion experiments conducted on some heterogeneous systems have been observed to show periodicities in the data. These “coherence patterns” are manifest in the normalized PGSE signal intensities as a function of the spatial wave vector q in so-called q-space plots. The sample that to our knowledge best reveals these coherence patterns is suspensions of red blood cells (RBC). The origin of these patterns and their mathematical and physical underpinnings are now well established. We have used computer simulations of molecular diffusion in lattices of RBC and other cells to aid in the interpretation and analysis of the corresponding experimental data. The aim of this review is to present the current status of NMR q-space studies of RBC suspensions that show the diffusion-coherence effect.