Adaptive control processes

X-ray microtomography

In this paper, the role and importance of the machine vision systems in the industrial applications are described. First understanding of the vision in terms of a universal concept is explained. System design methodology is discussed and a generic machine vision model is reported. Such a machine includes systems and sub-systems, which of course depend on the type of applications and required tasks. In general, expected functions from a vision machine are the exploitation and imposition of the environmental constraint of a scene, the capturing of the images, analysis of those captured images, recognition of certain objects and features within each image, and the initiation of subsequent actions in order to accept or reject the corresponding objects. After a vision system performs all these stages, the task in hand is almost completed. Here, the sequence and proper functioning of each system and sub-systems in terms of high-quality images is explained. In operation, there is a scene with some constraint, first step for the machine is the image acquisition, pre-processing of image, segmentation, feature extraction, classification, inspection, and finally actuation, which is an interaction with the scene under study. At the end of this report, industrial image vision applications are explained in detail. Such applications include the area of automated visual inspection (AVI), process control, parts identification, and important role in the robotic guidance and control. Vision developments in manufacturing that can result in improvements in the reliability, in the product quality, and enabling technology for a new production process are presented. The key points in design and applications of a machine vision system are also presented. Such considerations can be generally classified into the six different categories such as the scene constraints, image acquisition, image pre-processing, image processing, machine vision justification, and finally the systematic considerations. Each aspect of such processes is described here and the proper condition for an optimal design is reported.

Design and application of industrial machine vision systems

This paper presents a novel technique for hand gesture recognition through human---computer interaction based on shape analysis. The main objective of this effort is to explore the utility of a neural network-based approach to the recognition of the hand gestures. A unique multi-layer perception of neural network is built for classification by using back-propagation learning algorithm. The goal of static hand gesture recognition is to classify the given hand gesture data represented by some features into some predefined finite number of gesture classes. The proposed system presents a recognition algorithm to recognize a set of six specific static hand gestures, namely: Open, Close, Cut, Paste, Maximize, and Minimize. The hand gesture image is passed through three stages, preprocessing, feature extraction, and classification. In preprocessing stage some operations are applied to extract the hand gesture from its background and prepare the hand gesture image for the feature extraction stage. In the first method, the hand contour is used as a feature which treats scaling and translation of problems (in some cases). The complex moment algorithm is, however, used to describe the hand gesture and treat the rotation problem in addition to the scaling and translation. The algorithm used in a multi-layer neural network classifier which uses back-propagation learning algorithm. The results show that the first method has a performance of 70.83% recognition, while the second method, proposed in this article, has a better performance of 86.38% recognition rate.

RETRACTED ARTICLE: Static hand gesture recognition using neural networks

One of the long- and widely held ideas about the dynamics of meandering
rivers is that migration slows down in bends with higher curvatures.
Identifying the radius of curvature at which migration is fastest is
standard practice in field studies of meandering rivers. High-resolution
measurements of local migration rates in time-lapse Landsat images from
two rapidly migrating rivers in the Amazon Basin suggest that the
variation of migration rate closely follows that of the local curvature,
with a roughly constant phase lag between the two; and a quasi-linear
relationship exists between curvature and migration rate if this lag is
taken into account. A simple numerical model of meandering illustrates
the link between curvature and migration rate and reproduces
observations from the studied rivers. The implication is that meandering
rivers migrate fastest at, and slightly downstream of, locations of
high curvature; and one of the most important ways river migration is
rejuvenated and meandering patterns are reshuffled is the generation of
high-curvature bends through cutoffs.

https://eartharxiv.org/repository/object/1536/download/3406/

High curvatures drive river meandering

System design scene constraints image acquisition image preprocessing image understanding image analysis pattern classification applications and case studies visual inspection robotic vision and control.

Applied Image Processing

https://pure.aber.ac.uk/portal/files/26903907/1_s2.0_S0169555X18301065_main.pdf

Morphology and spacing of river meander scrolls

Heat treatment was one of the first transformative technologies in the southern African Middle Stone Age (MSA), with many studies in the Cape coastal zone of South Africa identifying it as an essential step in the preparation of silcrete prior to its use in stone tool manufacture. To date, however, no studies have investigated whether heat treatment is necessary for all silcrete types, and how geographically widespread heat treatment was in the subcontinent. The aim of this study is to investigate experimentally whether heat treatment continued further north into the Kalahari Desert of Botswana and northernmost South Africa, the closest area with major silcrete outcrops to the Cape. For this we analyse the thermal transformations of silcrete from both regions, proposing a comprehensive model of the chemical, crystallographic and `water'-related processes taking place upon heat treatment. For the first time, we also explore the mobility of minor and trace elements during heat treatment and introduce a previously undescribed mechanism - steam leaching - causing depletion of a limited number of elements. The results of this comparative study reveal the Cape and Kalahari silcrete to respond fundamentally differently to heat treatment. While the former can be significantly improved by heat, the latter is deteriorated in terms of knapping quality. These findings have important implications for our understanding of the role of fire as a technical solution in MSA stone tool knapping, and for the extension of its use in southern Africa. Silcrete heat treatment - at least in the form we understand it today - may have been a strictly regional phenomenon, confined to a narrow zone along the west and south coast of the Cape. On the basis of our findings, silcrete heat treatment should not be added as a new trait on the list of behaviours that characterise the MSA of the southern African subcontinent.

/pdf/heat-treatment-as-a-universal-technical-solution-for-45t4p8rw5m.pdf

Heat treatment as a universal technical solution for silcrete use? A comparison between silcrete from the Western Cape (South Africa) and the Kalahari (Botswana).

This paper presents the development of a newstrategy for the calibration of air-fuel ratio measurements in engines by laser-induced fluorescence (LIF). After a brief introduction to the LIF technique, the paper highlights the structured approach undertaken to ensure that accurate quantitative measurements were produced. In particular, the new approach to coping with the fluorescence dependency on pressure and temperature, the issues related to the choice of a fluorescence tracer, the careful determination of the optimum tracer concentration and the complete calibration methodology are described, together with the resolution of some of the obstacles encountered. The paper concludes with some examples of calibrated measurements accompanied by a comparison of the results with combustion and emission performances. These results show a very good correlation.

On the use of laser-induced fluorescence for the measurement of in-cylinder air—fuel ratios:

Hydrological alteration due to climate change events such as floods and drought is a significant threat to globally important wetlands, including floodplain wet grasslands. This research incorporated two field experiments with the aim to assess immediate and longer-term functional responses of floodplain plants to hydrological change. Plant introductions and transplants between a wetter riparian and a drier site in southern England were used to simulate hydrological change. Species showed immediate and differential responses to contrasting hydrologies. Rhinanthus minor, a hemi-parasitic annual species with ruderal traits, was lost from the riparian grassland within four weeks. The survival and production of a leguminous perennial, Lathyrus pratensis, in high groundwater levels soon decreased. However, the perennial Primula veris mostly functioned well in contrasting hydrological regimes, possibly because it can tolerate stress. The perennial wetland species Caltha palustris showed lag effects, over three years, when its hydrology was altered to a sub-optimal drier scenario by transplantation, with declining survival and a sustained reduction in leaf production and flowering. Disturbance caused by transplantation and weather conditions also affected its performance. Thus, this study shows that some functionally important floodplain species may succumb within weeks to a hydrological event facilitated by climate change, unless they are able to tolerate the challenging conditions, while the performance of other characteristic species could decline and continue to show constrained performance for years as a consequence of altered hydrology.

/pdf/immediate-and-lag-effects-of-hydrological-change-on-xpbneekq72.pdf

G. Awcock

Papers

Applied Image Processing

Morphology and spacing of river meander scrolls

Heat treatment as a universal technical solution for silcrete use? A comparison between silcrete from the Western Cape (South Africa) and the Kalahari (Botswana).

On the use of laser-induced fluorescence for the measurement of in-cylinder air—fuel ratios:

Immediate and lag effects of hydrological change on floodplain grassland plants