The ontogeny of long-term memory over the first year-and-a-half of life

This research documents the development of long-term memory in human infants from 2 months through the end of the first year-and-a-half of life. In the initial study phase, we trained 6- to 18-month-old human infants in an operant task and tested them after increasing delays until they exhibited no retention for 2 successive weeks. In the second phase, their data were combined with data previously obtained from 2- to 6-month-olds in an equivalent task. The resulting function revealed that the duration of retention increases monotonically between 2 and 18 months of age. This increase was not due to age differences in original learning. This is the first systematic analysis of the course of long-term memory across an extended period of infant development that is based on standardized parameters of training and testing. It provides a reference function against which measures of retention from infants of different ages that are obtained in different memory tasks with different parameters can be meaningfully compared.     

Using wavelet transforms for ECG characterization. An on-linedigital signal processing system

The rapid and objective measurement of timing intervals of the electrocardiogram (ECG) by automated systems is superior to the subjective assessment of ECG morphology. The timing interval measurements are usually made from the onset to the termination of any component of the EGG, after accurate detection of the QRS complex. This article describes a real-time system that uses wavelet transforms to overcome the limitations of other methods of detecting QRS and the onsets and offsets of P- and T-waves. Wavelet transformation is briefly discussed, and detection methods and hardware and software aspects of the system are presented, as well as experimental results     

Routing multiple paths in hypercubes

We present new techniques for mapping computations onto hypercubes. Our methods speed up classical implementations of grid and tree communications by a factor of (n), wheren is the number of hypercube dimensions. The speedups are asymptotically the best possible.We obtain these speedups by mapping each edge of the guest graph onto short, edge-disjoint paths in the hypercube such that the maximum congestion on any hypercube edge isO(1). These multiple-path embeddings can be used to reduce communication time for large grid-based scientific computations, to increase tolerance to link faults, and for fast routing of large messages.We also develop a general technique for deriving multiple-path embeddings from multiple-copy embeddings. Multiple-copy embeddings are one-to-one maps of independent copies of the guest graph within the hypercube. We present an efficient multiple-copy embedding of the cube-connected-cycles network within the hypercube. This embedding is used to derive efficient multiple-path embeddings of trees and butterfly networks in hypercubes.This research was supported by NSF/DARRA Grant CCR-8908285, NSF Grant CCR-8807426, and AFOSR Grant 89-0382.     

Investigations on N-halogen cyclic ureide based magnesium primary cell system at various temperatures

This paper reports the results of experimental studies on a magnesium/magnesium perchlorate/N,N-dichlorodimethylhydantoin cell system at various temperatures ranging from 70 to –20° C. A constant current discharge method was employed to evaluate the battery parameters such as discharge capacity, energy density, coulombic efficiency and internal resistance. Cyclic voltammetric (CV) investigations of the N,N-dichlorodimethylhydantoin (DDH) were carried out in 0.1 M magnesium perchlorate medium in order to supplement the results. Scanning electron microscopy (SEM) was performed on post-polarized magnesium samples to follow the morphological changes in the anodic material with respect to temperatures. These investigations broadly reveal that the cell system can give rise to the open-circuit/closed-circuit voltage of 2.0 V and it is possible to obtain current densities of 20 mA cm^–2 during discharge.