On operator effectiveness: the role of expertise and familiarity of environment on the detection of deviant behaviour

This paper examines factors contributing to the effectiveness of camera operators in urban camera surveillance. The use of camera surveillance has taken an enormous flight in the past decades. Despite this increase, its effectiveness is strongly debated. One reason for the disputed effectiveness may be that an understanding of how to use camera surveillance, including elements contributing to the effectiveness of camera operators, has not kept track with technological developments. This paper focuses on the role of expertise and familiarity with the environment on the effectiveness of camera operators to detect offenders in video footage from Rotterdam City Surveillance in the Netherlands. Results show no effect of expertise, but do show that familiarity with the location contributes to operator effectiveness and that camera operators seem to use different criteria for detecting and selecting suspects depending on the familiarity with the location. These results contribute to our understanding of operator effectiveness and offer guidelines for the training of camera operators. Implications are discussed.     

Ubiquitous emotion-aware computing

Emotions are a crucial element for personal and ubiquitous computing. What to sense and how to sense it, however, remain a challenge. This study explores the rare combination of speech, electrocardiogram, and a revised Self-Assessment Mannequin to assess people’s emotions. 40 people watched 30 International Affective Picture System pictures in either an office or a living-room environment. Additionally, their personality traits neuroticism and extroversion and demographic information (i.e., gender, nationality, and level of education) were recorded. The resulting data were analyzed using both basic emotion categories and the valence--arousal model, which enabled a comparison between both representations. The combination of heart rate variability and three speech measures (i.e., variability of the fundamental frequency of pitch (F0), intensity, and energy) explained 90% (p < .001) of the participants’ experienced valence--arousal, with 88% for valence and 99% for arousal (ps < .001). The six basic emotions could also be discriminated (p < .001), although the explained variance was much lower: 18–20%. Environment (or context), the personality trait neuroticism, and gender proved to be useful when a nuanced assessment of people’s emotions was needed. Taken together, this study provides a significant leap toward robust, generic, and ubiquitous emotion-aware computing.     

Flexible electronics: Prediction of substrate deformation during different steps of the lithography process

A numerical model was developed to simulate the micro-deformations of a polymeric substrate due to lithographic processing of different layers of a transistor-like structure. The results of the model were validated with the results from experiments. The model, a mechanical-thermal-hygroscopic model, takes into account the dimensional effects of temperature, moisture and stresses. It also includes the temperature dependent visco-elastic behaviour of the polymer substrate. The model can be used to predict overlay accuracies between different functional layers introduced by the lithographic process. It can also be used to understand the underlying processes such that it provides a tool to improve the overlay accuracy during actual processing.     

Evaluating expectations about negative emotional states of aggressive boys using Bayesian model selection.

Researchers often have expectations about the research outcomes in regard to inequality constraints between, e.g., group means. Consider the example of researchers who investigated the effects of inducing a negative emotional state in aggressive boys. It was expected that highly aggressive boys would, on average, score higher on aggressive responses toward other peers than moderately aggressive boys, who would in turn score higher than nonaggressive boys. In most cases, null hypothesis testing is used to evaluate such hypotheses. We show, however, that hypotheses formulated using inequality constraints between the group means are generally not evaluated properly. The wrong hypotheses are tested, i.e.. the null hypothesis that group means are equal. In this article, we propose an innovative solution to these above-mentioned issues using Bayesian model selection, which we illustrate using a case study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exact solutions to the modified 2D Burgers vortex equation: a general result for the unsteady case

Exact solutions to the unsteady modified 2D Burgers vortex equation are obtained for arbitrary forms of the flow parameter γ(t) via Fourier analysis. The result extends the available literature, where only very specific forms of the flow parameter γ(t) have been considered in the unsteady flow cases. One strength of the method is that we need not assume separable solutions.     

Zirconia-modified exfoliated graphite

Zirconia has been incorporated into exfoliated graphite (EG) through the anodic polarization in the natural graphite-ZrO(NO₃)₂-HNO₃-H₂O system, followed by flash heating. The thermal properties of the oxidized graphites employed as precursors to EG have been studied by thermogravimetry in combination with differential scanning calorimetry, and the distribution of ZrO₂ particles in the EG has been assessed by scanning and transmission electron microscopy. Conditions are described for the preparation of EG with bulk densities in the range 1.3–4.7 g/l and ZrO₂ contents in the range 4–34 wt %.     

Variational density matrix optimization using semidefinite programming

We discuss how semidefinite programming can be used to determine the second-order density matrix directly through a variational optimization. We show how the problem of characterizing a physical or N-representable density matrix leads to matrix-positivity constraints on the density matrix. We then formulate this in a standard semidefinite programming form, after which two interior point methods are discussed to solve the SDP. As an example we show the results of an application of the method on the isoelectronic series of Beryllium.     

A Revised Criterion for the Portevin–Le Chatelier Effect Based on the Strain-Rate Sensitivity of the Work-Hardening Rate

An improved analysis is presented of the stability of plastic deformation under conditions where dynamic strain aging (DSA) occurs, which leads to instabilities known as the Portevin–Le Chatelier (PLC) effect. It is shown that PLC instabilities can occur for conditions that are not covered by the currently prevailing criterion presented by Estrin and Kubin (1991), which focuses on a negative strain rate sensitivity of the flow stress, caused by interactions of solutes with thermally activated glide of mobile dislocations. The current analysis recognizes that the strain-rate sensitivity of the flow stress consists of two contributions, one associated with glide of mobile dislocations and the second with work hardening, related to storage of immobile dislocations. In this paper, an instability criterion is proposed that takes into account the possibility of a negative strain-rate sensitivity of the work-hardening rate, which is caused by diffusion of solutes to immobile dislocations. The latter contribution leads to an extended instability criterion. This criterion also provides an explanation for the existence of a critical strain above which instabilities occur. In this article, previously published tensile test data are used to show that a negative strain-rate sensitivity of the work-hardening rate, which influences significantly the occurrence of the PLC effect, can indeed occur under DSA conditions.     

An in-vitro method for prediction of the digestible crude protein content in pig feeds

An in-vitro method using commercially available enzymes for the prediction of the in-vivo digestible crude protein content was developed and tested on seven feedstuffs and 16 diets for pigs. Fat-extracted feed samples were consecutively incubated with pepsin at pH 1 and pancreatin at pH 6.8. From the nitrogen content of the feed sample and of the residue after incubation the in-vitro digestibility of the crude protein was calculated. Using the linear regression of in-vitro on in-vivo digestible crude protein of samples obtained in feeding trials, the in-vivo digestible crude protein content (DXP_p) in g kg^?1 dry matter could be predicted. For feedstuffs and diets the correlation was 0.99 and 0.95 and the residual standard deviation 17 and 6 g kg^?1 dry matter, respectively. In a similar procedure the nitrogen solubilised during incubation with enzymes was analysed. The regression value was similar to that of the original procedure. However, this procedure was abandoned because it was more laborious.     

Smoothing Streams in an In-Home Digital Network: Optimization of Bus and Buffer Usage

In an in-home digital network it may be expected that several data streams (audio, video) run simultaneously over a shared communication device, e.g., a bus. The burstiness of a data stream can be reduced by buffering data at the sending and receiving side, thereby allowing a lower bus share allocation for the stream. In this paper we present an algorithm that determines how much of the bus capacity and buffer space should be allocated to each stream, in order to have a feasible transmission schedule for each stream. Furthermore, the algorithm determines a transmission schedule for each stream, indicating how much data is transmitted over time. We show how this multiple-stream problem can be solved by repeatedly solving single-stream problems. We present efficient algorithms to solve these single-stream problems. Furthermore, we present some experimental results. This revised version was published online in September 2006 with corrections to the Cover Date.