Heterodyne detection at 10.6 ?m using quasiplanar metal-oxide-metal tunnel diodes

Novel high-performance, symmetrical metal-oxide-metal tunnel diodes (MOMTDs) in a quasiplanar configuration (US patent 4 549 194) have been successfully fabricated, and for the first time used as room-temperature detectors for the heterodyne mixing of two CO2 lasers operating on the P14 line near ? = 10.6 ?m. Using these devices, we have achieved state-of-the-art NEP (noise equivalent power) in the 4 to 6 × 10?16 W/Hz range and a D* of 5 × 106 cm Hz?/W.     

Elderly drivers: Future challenges?

The objective of this paper is to describe and interpret the results from a public opinion poll about elderly drivers to provide useful information regarding future challenges related to elderly drivers. The introduction describes demographic developments, factors affecting elderly drivers, crash rates of elderly drivers and characteristics of crashes of elderly drivers. This information is used to provide a context to interpret the results of the public opinion poll. A total of 1238 drivers completed the interview, which required an average of approximately 15 min per respondent. It was administered by telephone to a random sample of Canadian drivers by Opinion Search Inc., in September 2007. Criteria for inclusion were having a valid driver's license and having driven in the past 30 days. Data were weighted according to region, gender and age to avoid bias. Univariate frequency distributions, their 95% confidence intervals and Chi-square statistics were calculated taking account of the stratified and weighted sampling design. Also, multivariate logistic regression was performed, accounting for the design effects of the used sampling design. Lower levels of concern about the issue of elderly drivers were found among the public at large and especially among elderly drivers. While general support for actions to protect elderly drivers was high, elderly drivers were less supportive for a measure requiring them to complete training to maintain their driving privileges. The results from this survey are contrasted against what is known from the literature about the issue of elderly drivers and conclusions regarding future challenges are drawn.     

Selective attention and control of action: Comparative psychology of an artificial, evolved agent and people.

This study examined the selective attention abilities of a simple, artificial, evolved agent and considered implications of the agent's performance for theories of selective attention and action. The agent processed two targets in continuous time, catching one and then the other. This task required many cognitive operations, including prioritizing the first target (T1) over the second (T2); selectively focusing responses on T1, while preventing T2 from interfering with responses; creating a memory for the unselected T2 item, so that it could be efficiently processed later; and reallocating processing towards T2 after catching T1. The evolved agent demonstrated all these abilities. Analysis shows that the agent used reactive inhibition to selectively focus behavior. That is, the more salient T2, the more strongly responses towards T2 were inhibited and the slower the agent was to subsequently reallocate processing towards T2. Reactive inhibition was also suggested in two experiments with people, performing a virtually identical catch task. The presence of reactive inhibition in the simple agent and in people suggests that it is an important mechanism for selective processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reducing intergroup bias: Elements of intergroup cooperation.

The authors examined the potentially separable contributions of 2 elements of intergroup cooperation, interaction and common fate, and the processes through which they can operate. The manipulation of interaction reduced bias in evaluative ratings, which supports the idea that these components are separable, whereas the manipulation of common fate when the groups were interacting was associated with lower bias in nonverbal facial reactions in response to contributions by in-group and out-group members. Whereas interaction activated several processes that can lead to reduced bias, including decategorization, consistent with the common in-group identity model (S. L. Gaertner, I F. Dovidio, P. A. Anastasio, B. A. Bachman, & M. C. Rust, 1993) as well as M. Hewstone and R. J. Brown's (1986) group differentiation model, the primary set of mediators involved participants' representations of the memberships as 2 subgroups within a superordinate entity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Supporting ordinal four-state classification decisions using neural networks

Many accounting and finance problems require ordinal multi-state classification decisions, (e.g., control risk, bond rating, financial distress, etc.), yet few decision support systems are available to aid decision makers in such tasks. In this study, we develop a Neural Network based decision support system (NN-DSS) to classify firms in four ordinal states of financial condition namely healthy, dividend reduction, debt default and bankrupt. The classification results of the NN-DSS model are compared with those of a Naïve model, a Multiple Discriminant Analysis (MDA) model, and an Ordinal Logistic Regression (OLGR) model. Four different evaluation criteria are used to compare the models, namely, simple classification accuracy, distance-weighted classification accuracy, expected cost of misclassification (ECM) and ranked probability score. Our study shows that NN-DSS models perform significantly better than the Naïve, MDA, and OLGR models on the ECM criteria, and provide better results than MDA and OLGR on other criteria, although not always significantly better. The effect of the proportion of firms of each state in the training set is also studied. A balanced training set leads to more uniform (less skewed) classification across all four states, whereas an unbalanced training set biases the classification results in favor of the state with the largest number of observations.     

Development of enzyme biosensor based on trypsin and conductometric thin-film electrodes for protein and artificial substrates determination

ULTRA was established on the 1st April 1990, to consider applications made by registered medical practitioners seeking approval to transplant an organ between 2 living unrelated persons in the United Kingdom.     

A novel algorithm and architecture for adaptive digital beamforming

A novel algorithm and architecture are described which have specific application to high performance, digital, adaptive beamforming. It is shown how a simple, linearly constrained adaptive combiner forms the basis for a wide range of adaptive antenna subsystems. The function of such an adaptive combiner is formulated as a recursive least squares minimization operation and the corresponding weight vector is obtained by means of theQ-Rdecomposition algorithm using Givens rotations. An efficient pipelined architecture to implement this algorithm is also described. It takes the form of a triangular systolic/wavefront array and has many desirable features for very large scale integration (VLSI) system design.     

Mechanical anisotropy of highly oriented polymers

Recent progress on the understanding of the mechanical anisotropy of orientedpolymers is reviewed. The key issues that are discussed include theexperimental validation of theoretical predictions for the elastic constantsof fibres, quantitative interpretations of the mechanical anisotropy of chain-extended polyethylenes and liquid crystalline polymers using aggregate models,the analysis of anisotropic polymers and fibre/resin composites and compositemodels for specially oriented polyethylene sheets and high moduluspolyethylene fibres.