Real-Time Classification of Multiunit Neural Signals Using Reduced Feature Sets

Classification of characteristic neural spike shapes in multi-unit recordings is performed in real time using a reduced feature set. A model of uncorrelated signal-related noise is used to reduce the feature set by choosing a subset of aperiodic samples which is effective for discrimination between signals by a nearest-mean algorithm. Initial signal classes are determined by an unsupervised clustering algorithm applied to the reduced features of the learning set events. Classification is carried out in real time using a distance measure derived for the reduced feature set. Examples of separation and correlation of multiunit activity from cat and frog visual systems are described.     

Quantitative camouflage paint selection for the CH‐47F helicopter

We have determined optimal minimum‐conspicuity monocoat paint colors for the CH‐47F Chinook helicopter, viewed photopically against forest, desert, and sky backgrounds. Our methodology combines use of a validated spectroradiometric model for rigorous 3D signature prediction with statistics of varying background fields and a CIE color difference metric. The study considered a large subset of the Federal Standard 595 (FS595) paint inventory. Each paint color was rigorously modeled with bidirectional reflectance distribution function scattering properties to match existing army paint and spectral reflectances to match spectrophotometer measurements of FS595 reference samples. We devised and validated a method to impute statistical variation in background radiances over environmental conditions consistent with the aircraft radiometric computations. Using a visual jury, we informally calibrated the CIE 1994 color difference formula (which gauges both luminance and chromaticity contrast) to gauge how each paint performed against each background, for varying range, view direction, and sun location. The statistical dispersions in performance were summarized for the CH‐47F Program Manager, who selected the best overall paint for the CH‐47F fleet. We found paints that were optimized to a specific background (forest, desert, etc.) yielded enhanced performance against those backgrounds, as would be expected, and that those paints were better than the paint used on CH‐47s in the current US inventory. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 406–416, 2009     

Validation of the Satz-Mogel short form for the WAIS-R with psychiatric inpatients.

Original WAIS-R protocol records of 64 psychotic, nonpsychotic, and organic inpatients (aged 19–72 yrs) were rescored to obtain Satz-Mogel short-form scale scores and IQs. Pearson product-moment correlations were found to be uniformly high (p?     

Non-neoplastic stenosis of the aqueduct presenting in adolescence and adult life

Twenty-six cases of non-neoplastic stenosis of the aqueduct are reviewed. This condition may take a very chronic course and may not be revealed until decompensation of hydrocephalus takes place. Poor athletic record in the school or intellectual impairment in early life, commonly overlooked, can presage the more obvious symptoms. A prolonged follow-up of these cases is essential to exclude a slowly growing neoplasm near the aqueduct. Our management and the outcome of these cases is discussed.     

Delayed presentation of esophageal perforation as a result of overtube placement

The first use of an overtube to assist endoscopy was described more than 20 years ago. Since then a number of uses of overtubes have been described, but relatively few complications have been reported. We report a case of esophageal perforation caused by overtube insertion during endoscopic band ligation of varices. This case is unique in that the patient presented 13 days after the original procedure, and it is the first reported case of esophageal injury involving the modified Bard overtube. The existing literature involving overtube injury is also reviewed.     

A survey of synchronization methods for parallel computers

An examination is given of how traditional synchronization methods influence the design of MIMD (multiple-instruction multiple-data-stream) multiprocessors. She provides an overview of MIMD multiprocessing and goes on to discuss semaphore-based implementations (Ultracomputers, Cedar, and the Sequent Balance/21000), monitor-based implementations (the HM²p) and implementations based on message-passing (HEP, the BBN Butterfly and the Transputer)