Pulse-stream VLSI neural networks mixing analog and digitaltechniques

The pulse-stream technique, which represents neural states as sequences of pulses, is reviewed. Several general issues are raised, and generic methods appraised, for pulsed encoding, arithmetic, and intercommunication schemes. Two contrasting synapse designs are presented and compared. The first is based on a fully analog computational form in which the only digital component is the signaling mechanism itself-asynchronous, pulse-rate encoded digital voltage pulses. In this circuit, multiplication occurs in the voltage/current domain. The second design uses more conventional digital memory for weight storage, with synapse circuits based on pulse stretching. Integrated circuits implementing up to 15000 analog, fully programmable synaptic connections are described. A demonstrator project is described in which a small robot localization network is implemented using asynchronous, analog, pulse-stream devices.     

Non-pinched, minimum energy distillation designs

Non-pinched, minimum energy solutions are important class of distillation designs that offer the potential advantage of a better trade-off between capital investment and operating costs. In this paper, two important tasks associated with non-pinched distillation designs are studied. Thus the novel contributions of this work to the literature are

(1) A comprehensive methodology for finding non-pinched minimum energy designs.

(2) Understanding of the reasons for the existence of non-pinched distillation designs.

It is shown that the recent shortest stripping line distance approach of Lucia et al. [Lucia, A., Amale, A. and Taylor, R., 2007, Distillation pinch points and more. Comput Chem Eng, available on-line] is capable of systematically and reliably finding non-pinched, minimum energy distillation designs. In addition, we provide an understanding of the reasons behind the existence of non-pinched designs, which include trajectories that follow unstable branches of a pinch point curve in azeotropic systems, the inherent looping structure of trajectories in hydrocarbon separations, and the presence of ancillary constraints in multi-unit processes like extraction/distillation. Several distillation examples are studied and many numerical results and geometric illustrations are presented that show the shortest stripping line distance methodology is indeed a powerful and systematic tool for computing non-pinched, minimum energy designs and that support the underlying reason we provide for the existence of non-pinched designs.     

Continuous and Discontinuous Innovation: Overcoming the Innovator Dilemma

Challenged by competition pressures and unprecedented pace of change, firms can no longer choose whether to concentrate on the needs of today's customers or on the anticipation of those of tomorrow: they must be excellent in both. This requires managing two related balancing acts: on the one side, being excellent in both exploitation and exploration of their capabilities and, on the other side, being excellent in managing both incremental and radical innovation. These balances are critical since exploitation and exploration, on the one side, and incremental and radical innovation, on the other, require different approaches that have traditionally been considered difficult to combine within the same organization. Working on evidence and discussion from the 7th CINet Conference held in Lucca (Italy) in 2006, this Special Section is aimed at contributing to theory and practice on these two complex balancing acts that today represent a hot issue in innovation management.     

A Neural Network Model of Caenorhabditis Elegans: The Circuit of Touch Sensitivity

The paper presents a neural network model of the touch sensitivity circuit of the nematode Caenorhabditis elegans. We describe a serie of simulations in which neural networks are trained, using a genetic algorithm, to reproduce the habituation of the nematode's touch sensitive behavior. A lesion study of the network allows to make a direct comparison between the fine functioning of the model and the data collected in real organisms. The model accords well with the known neurobiological data and it suggests some hypotheses about the functioning of the neural circuit and of single neurons.     

Feasibility of a long-term low-sodium diet in mild hypertension

The present study set out to assess the feasibility of long-term moderate dietary sodium restriction in patients with mild hypertension in general practice. After screening and a run-in phase of 6-8 weeks, a total of 77 previously undiagnosed mildly hypertensive patients were identified. Half of them were randomized to receive a few simple dietary instructions from their general practitioners in order to reduce salt usage; the others were randomized to receive no advice. The patients were followed up for 12 months with quarterly visits. A total of 56 patients (72.7%) completed the study, 26 on a low-sodium diet (LD) and 30 on their usual diet (UD). At each visit in the diet phase, patients provided 24h urine, which was analysed for volume and sodium concentration in order to assess their sodium intake. Blood pressure, heart the rate and body weight were recorded. The mean urinary sodium excretion for all diet phase visits overlapped in the two groups (177.0 +/- 32.9 vs. 169.3 +/- 49.4 mEq/24h respectively in the LD and UD groups). Nevertheless the mean systolic and diastolic blood pressures for all diet phase visits were significantly lower in the LD than in UD group (144.2 +/- 11.1/91.6 +/- 6.4 and 148.0 +/- 13.7/95.6 +/- 4.7 mmHg respectively, P less than 0.01). Our data suggest that it is not feasible at present to reduce sodium intake in mild hypertensives with simple and inexpensive dietary instructions, the only ones suitable for widespread application in general practice.     

Effects of category prototypes on performance-rating accuracy.

Two studies examined whether the accessibility of performance prototypes influences performance appraisals. Pilot studies revealed students used performance prototypes when rating instructor performance. Study 1 manipulated the accessibility of these prototypes and the time delay of performance ratings. Results showed no effect of the prime on rating error and accuracy; however, discrimination accuracy decreased over time and recognition bias became more conservative. Study 2 manipulated prototype accessibility and type of rating stimuli (videotape vs. vignette). Rating accuracy and recall were higher for vignette than videotape stimuli, and only those participants exposed to the vignette exhibited priming effects. Results supported transfer-appropriate processing and implied that cognitive primes may have a stronger effect on performance ratings based on "paper-people" than videotaped stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognition of Adulterated Oils by Direct Analysis of the Minor Components

Recognition of adulteration by other oils via direct analysis of the minor components (“sterol fraction”) is shown for olive oil. 10 % of various oils were admixed, the free alcohols silylated and the minor components analyzed by on-line coupled LC-GC-FID. For most oils, even smaller additions can be recognized. Admixed oils can no longer be determined, however, if their minor components have been removed by strong raffination. Bleaching of rapeseed oil with 7% of earth at 180 °C, in fact, completely removed free and esterified sterols.     

Simulation of Facial Muscle Actions Based on Rational Free Form Deformations

This paper describes interactive facilities for simulating abstract muscle actions using Rational Free Form Deformations (RFFD). The particular muscle action is simulated as the displacement of the control points of the control-unit for an RFFD defined on a region of interest. One or several simulated muscle actions constitute a Minimum Perceptible Action (MPA), which is defined as the atomic action unit, similar to Action Unit (AU) of the Facial Action Coding System (FACS), to build an expression.