A decision theoretic approach to file search

We investigate the relationship between algorithm construction and optimal decision processes. We provide a sufficient condition, a linear ordering over the experiment set, for when we can efficiently use an optimization approach for selecting a decision strategy. We demonstrate the linear ordering condition within the context of the file search problem; however, any problem whose representation satisfies the linear ordering condition is amenable to the optimization approach.     

Neuronal codes: reading them and learning how their structure influences network organization

Antioxidant enzymes together with trace elements in 26 patients with chronic renal failure treated with hemodialysis and 25 healthy subjects were investigated. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSHPx) in plasma and erythrocytes were examined immediately before and after hemodialysis. The results are summarized as follows: 1. A significant decrease in plasma SOD, CAT, and GSHPx and erythrocyte GSHPx were found in patients before hemodialysis. 2. Erythrocyte CAT and GSHPx were significantly lower in the patients after hemodialysis than in the controls. 3. Plasma GSHPx was significantly higher after a single hemodialysis than before hemodialysis. 4. A good correlation between erythrocyte SOD and copper (Cu) in patients before hemodialysis was found. 5. A good correlation of GSHPx in erythrocytes and plasma was found before hemodialysis, whereas an even better correlation was found after hemodialysis. 6. Abnormalities of trace elements were found in hemodialyzed patients. 7. There is indirect evidence for increased oxidizing stress in uremic patients with hemodialysis. Dialysis treatment may improve some abnormalities (e.g., Hb, P), but may also induce some deleterious effects of free radicals or lipid peroxidation.     

Computer simulation and psychological theories of perception.

Computer simulations of perceptual processes have often not related directly to questions of concern to the psychology of perception and, in particular, have regarded perception as a sensory, as opposed to a sensorimotor or active, process. Some of the psychological literature which is relevant to the issue of perception as a passive vs. an active process is reviewed and differences between these alternative conceptions of perception and gains to be derived from using the active-perceiver model are spelled out. Past computer models are reviewed in the light of such theories. A different simulation program based explicitly on the active-perceiver model of perception is then sketched in broad outlines and its potential for doing research upon psychological problems is reviewed. (50 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Error rate for envelope-detected on?off keying in the presence of interference

The effects of an interfering carrier and Gaussian noise on envelope-detected on?off keying are analysed. Optimum decision levels with their resulting error rates were found numerically and are presented for a range of interference and noise levels.     

New strip drawing experiments using transparent sapphire dies

Experimental results are presented for carefully controlled plane-strain strip drawing experiments. Transparent aluminum oxide (sapphire) dies have been used to make direct observations of the die-work interface in strip drawing, including the distortion of scribed lines which were used for estimating velocity profiles at the interface. Such profiles can be used as input to theoretical models (Appleby et al., 1984), thus permitting the calculation of interface friction rather than requiring its assumption. Experiments were conducted with tungsten carbide, as well as sapphire, dies in which process parameters such as reduction, speed, die angle, lubricant, and back tension were varied, and die separating forces and drawing loads were measured. In general the friction was lower for the sapphire dies, but the variation with process parameters was similar. For one experiment, residual stresses in the product strip were measured. The results are believed to be documented in sufficient detail to be of general use in evaluating theoretical models.     

The strange case of the misplaced suppository

In a controversial decision, the General Medical Council has found a consultant anesthetist guilty of serious professional misconduct for giving a painkilling suppository without forewarning the patient and obtaining consent. Even though the suppository was misplaced in the patient's vagina, this was accepted as a mistake, at issue was whether a specific separate consent was required for insertion of the suppository.     

Error rate for p.s.k. and d.p.s.k. in the presence of source noise

The analysis of error rate in 2-level p.s.k. and d.p.s.k. systems has been extended to include the effects of source phase noise. Curves are presented for channel S/N ratios up to 6 dB and source phase deviations up to 0.6 rad r.m.s.