Low-cost interactive active monocular range finder

This paper describes a low-cost interactive active monocular range finder and illustrates the effect of introducing interactivity to the range acquisition process. The range finder consists of only one camera and a laser pointer, to which three LEDs are attached. When a user scans the laser along surfaces of objects, the camera captures the image of spots (one from the laser, and the others from LEDs), and triangulation is carried out using the camera\u27s viewing direction and the optical axis of the laser. The user interaction allows the range finder to acquire range data in which the sampling rate varies across the object depending on the underlying surface structures. Moreover, the processes of separating objects from the background and/or finding parts in the object can be achieved using the operator\u27s knowledge of the objects

Dynamic privacy in public surveillance

In implementing privacy protection in surveillance systems, designers must maximize privacy while retaining the system?s purpose. One way to achieve this is to combine data-hiding techniques with context-aware policies governing access to securely collected and stored data

Using interaction signatures to find and label chairs and floors

The use of interaction signatures to recognize objects without considering the object\u27s physical structure is discussed. Without object recognition, smart homes cannot make full use of video cameras because vision systems cannot provide object-related context to the human activities monitored. One important advantage of interaction signatures is that people frequently and repeatedly interact with household objects, so the system can build evidence for object locations and labels

Object labelling from human action recognition

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Symbolic representation and distributed matching strategies for schematics

This paper describes object-centered symbolic representation and distributed matching strategies of 3D objects in a schematic form which occur in engineering drawings and maps. The object-centered representation has a hierarchical structure and is constructed from symbolic representations of schematics. With this representation, two independent schematics representing the same object can be matched. We also consider matching strategies using distributed algorithms. The object recognition is carried out with two matching methods: (1) matching between an object model and observed data at the lowest level of the hierarchy, and (2) constraints propagation. The first is carried out with symbolic Hopfield-type neural networks and the second is achieved via hierarchical winner-takes-all algorithms<br /

Segmentation of intentional human gestures for sports video annotation

We present results on the recognition of intentional human gestures for video annotation and retrieval. We define a gesture as a particular, repeatable, human movement having a predefined meaning. An obvious application of the work is in sports video annotation where umpire gestures indicate specific events. Our approach is to augment video with data obtained from accelerometers worn as wrist bands by one or more officials. We present the recognition performance using a Hidden Markov Model approach for gesture modeling with both isolated gestures and gestures segmented from a stream

Microstructural evolution in Nimonic 263 for high temperature power plant

It is necessary to develop and implement new power plant due to both current energy and environmental demands. To enable these objectives to be met, the next generation of power plant must be more efficient. A common method of improving efficiency in plant is to increase the steam temperatures and pressures, which will necessitate the introduction of new materials. Nickel-based alloys lend themselves to high temperature and pressure applications due to their significant creep strength and the ability to operate at metal temperatures above 750°C. Steam header and pipework systems carry steam from the boilers to the turbines and are of particular interest in this research. Header and pipework systems experience high operating temperatures and pressures in the power plant, and it is therefore paramount that a suitable material is chosen and methodologies are put in place to predict their safe operating lifetimes Microstructural evolution in Nimonic 263, one candidate material for next generation plant, has been quantified using a variety of advanced analytical electron microscopy techniques, including field emission gun scanning electron microscopy (FEGSEM) and transmission electron microscopy (TEM). A focussed ion beam technique has also been used to produce site specific samples for examination in the TEM to assist in the identification of grain boundary precipitates. The changes occurring in the microstructure as a result of time and temperature of exposure have been quantified and the precipitates fully identified. The results are also compared to predictions from thermodynamic equilibrium calculations. It is shown that variation in exposure time and temperature can affect the microstructural development, and therefore the mechanical properties, of the Nimonic 263 alloy

Extensive crustal extraction in Earth’s early history inferred from molybdenum isotopes

Estimates of the volume of the earliest crust based on zircon ages and radiogenic isotopes remain equivocal. Stable isotope systems, such as molybdenum, have the potential to provide further constraints but remain underused due to the lack of complementarity between mantle and crustal reservoirs. Here we present molybdenum isotope data for Archaean komatiites and Phanerozoic komatiites and picrites and demonstrate that their mantle sources all possess subchondritic signatures complementary to the superchondritic continental crust. These results confirm that the present-day degree of mantle depletion was achieved by 3.5 billion years ago and that Earth has been in a steady state with respect to molybdenum recycling. Mass balance modelling shows that this early mantle depletion requires the extraction of a far greater volume of mafic-dominated protocrust than previously thought, more than twice the volume of the continental crust today, implying rapid crustal growth and destruction in the first billion years of Earth’s history