Signal classification through multifractal analysis and complex domain neural networks

This paper describes a system capable of classifying stochastic self-affine nonstationary signals produced by nonlinear systems. The classification and the analysis of these signals are important because these are generated by many real-world processes. The first stage of the signal classification process entails the transformation of the signal into the multifractal dimension domain, through the computation of the variance fractal dimension trajectory (VFDT). Features can then be extracted from the VFDT using a Kohonen self-organizing feature map. The second stage involves the use of a complex domain neural network and a probabilistic neural network to determine the class of a signal based on these extracted features. The results of this paper show that these techniques can be successful in creating a classification system which can obtain correct classification rates of about 87% when performing classification of such signals without knowing the number of classes.     

Comprehensive Automation for Specialty Crops: Year 1 results and lessons learned

Comprehensive Automation for Specialty Crops is a project focused on the needs of the specialty crops sector, with a focus on apples and nursery trees. The project’s main thrusts are the integration of robotics technology and plant science; understanding and overcoming socio-economic barriers to technology adoption; and making the results available to growers and stakeholders through a nationwide outreach program. In this article, we present the results obtained and lessons learned in the first year of the project with a reconfigurable mobility infrastructure for autonomous farm driving. We then present sensor systems developed to enable three real-world agricultural applications—insect monitoring, crop load scouting, and caliper measurement—and discuss how they can be deployed autonomously to yield increased production efficiency and reduced labor costs.     

Work hours, workload, sleep and fatigue in Australian Rail Industry employees

Research suggests that less than 5 h sleep in the 24 h prior to work and/or more than 16 h of wakefulness can significantly increase the likelihood of fatigue-related impairment and error at work. Studies have also shown exponential safety declines with time on shift, with roughly double the likelihood of accident or injury after 10 h relative to the first 8 h. While it is acknowledged that reduced sleep, increased wakefulness and longer work hours produce work-related fatigue, few studies have examined the impact of workload on this relationship. Studies in the rail industry have focused on drivers. This study investigated fatigue in a large sample of Australian Rail Industry Employees. Participants were from four companies (n = 90: 85m, 5f; mean age 40.2 ± 8.6 y). Data was analysed for a total of 713 shifts. Subjects wore wrist actigraphs and completed sleep and work diaries for 14-days. They also completed the Samn–Perelli Fatigue Scale at the beginning and end of shifts, and the NASA-TLX workload scale at least twice during each shift. Average (±SD) sleep length (7.2 ± 2.6 h), prior wake at shift end (12.0 ± 4.7 h), shift duration (8.0 ± 1.3) and fatigue (4.1 ± 1.3, “a little tired, less than fresh”) were within limits generally considered acceptable from a fatigue perspective. However, participants received 5 h or less sleep in the prior 24 h on 13%, were awake for at least 16 h at the end of 16% and worked at least 10 h on 7% of shifts. Subjects reported that they felt “extremely tired, very difficult to concentrate,” or “completely exhausted, unable to function effectively” on 13% of shifts. Sleep length (OR = 0.88, p < 0.01), shift duration (OR = 1.18, p < 0.05), night shift (REF = morning shift, OR = 2.12, p < 0.05) and workload ratings (OR = 1.2, p < 0.05) were significant predictors of ratings of extreme tiredness/exhaustion (yes/no). While on average, sleep loss, extended wakefulness, longer work hours and work-related fatigue do not appear problematic in this sample, there is still a notable percentage of shifts that are likely to be associated with high levels of work-related fatigue. Given the size of the Australian Rail Industry, with thousands of shifts occurring each day, this is potentially of operational concern. Further, results indicate that, in addition to sleep length, wakefulness and work hours, workload significantly influences fatigue. This has possible implications for bio-mathematical predictions of fatigue and for fatigue management more generally.     

Simulated train driving: fatigue, self-awareness and cognitive disengagement

Fatigue is a serious issue for the rail industry, increasing inefficiency and accident risk. The performance of 20 train drivers in a rail simulator was investigated at low, moderate and high fatigue levels. Psychomotor vigilance (PVT), self-rated performance and subjective alertness were also assessed. Alertness, PVT reaction times, extreme speed violations (>25% above the limit) and penalty brake applications increased with increasing fatigue level. In contrast, fuel use, draft (stretch) forces and braking errors were highest at moderate fatigue levels. Thus, at high fatigue levels, errors involving a failure to act (errors of omission) increased, whereas incorrect responses (errors of commission) decreased. The differential effect of fatigue on error types can be explained through a cognitive disengagement with the virtual train at high fatigue levels. Interaction with the train reduced dramatically, and accident risk increased. Awareness of fatigue-related performance changes was moderate at best. These findings are of operational concern.     

Creativity and Innovation in Haute Cuisine: Towards a Systemic Model

The contribution of this study is an increased understanding of personal creativity and the innovation process in haute cuisine, a validation of the socio‐cultural systems view of creativity and a model that accounts for the socio‐cultural dimensions of haute cuisine. In this paper we discuss existing views that conceptualize creativity and innovation in this sector as a sequential developmental process following the principles of operations management. However, based on in‐depth interviews with world‐renowned chefs, we argue for a systemic rather than sequential developmental process view. The reason for this is that the chefs interviewed understand the ‘creativity part’ of the innovation process as an embodied experience often guided by intuition and the ‘innovation part’ as a process of social evaluation greatly dependent on the perception, knowledge and value judgement of the testers from the leading restaurant guides. The main implications of the findings go beyond the haute cuisine sector and open areas for future research on creativity and intuition more generally.     

Examining the correlates of psychological aggression among a community sample of couples.

In this study, the authors examined the correlates of psychological aggression victimization and perpetration among a community sample of 145 heterosexual couples. For both women and men, psychological aggression victimization was associated with greater psychological distress, anxiety, and physical health symptoms beyond the effects of physical aggression. Psychological aggression victimization was also uniquely associated with higher levels of depression for women. Trait anger and poor relationship adjustment were the strongest correlates of psychological aggression perpetration across genders. Childhood father-to-child and father-to-mother aggressions were associated with psychological aggression perpetration for men only, suggesting possible distinct etiologies across genders. These data highlight the importance of the further development of models for psychological aggression in both women and men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Further specification of the five robust factors of personality.

Factor analysis of teacher ratings of 499 6th graders on 43 adjectives (e.g., curious, fearful) supported a 5-factor model of personality trait information. The factors are interpreted as reflecting introversion–extraversion, conscience-governed concern for others, will, anxiety, and intellect. A weak 6th factor related to creativity was also observed. Findings are discussed in relation to the existence of additional factors, the possibility that the correlations reflect the language used by raters rather than behavioral traits, and the potential utility of the ratings. The relation of the 5 robust factors to theories of interpersonal relations, H. J. Eysenck's (1953) 3-factor model, R. B. Catell's (1947) multiple-factor system, and studies of the semantic meaning of personality terms is also considered. (65 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functionalization of Silicon Surfaces for Device Applications

Over the past decade, there has been increasing interest in functionalizing silicon surfaces, avoiding the ubiquitous oxide overlayer utilized in most integrated circuits based upon silicon. While silicon is clearly the backbone material of the microelectronics industry, an understanding of its surface chemistry still remains in preliminary stages. The native oxide overlayer on silicon chips has served admirably well for most microelectronic applications but as the features on integrated circuits become increasingly small, the ability to tailor the interfacial properties of the surface is extremely desirable. As the well known Moore's law describes, the number of devices on an integrated circuit has been increasing exponentially since the early 1960's, approximately doubling every year to 18 months. The smallest feature on a Pentium processor chip is now about 300 nm, and both industry and academia look to make even tinier surface features and devices as the state-of-the-art moves from ultra-to giga-scale integration, with over 10 to 100 million transistors per chip. Because the surface properties of these nanoscale devices will have crucial effects on their performance, new surface terminations and the chemical tools to access them are required.