Chromatic Methodology Research Articles

Multispectral imaging: Monitoring vulnerable people

This paper describes the development of a new healthcare monitoring system for vulnerable people which uses a visible image sensor and passive infrared sensors, in an unconventional manner, to monitor daily living activities. It based on a novel method, using chromatic methodology, to process spatially and temporally the incoming multispectral data from the visible and infrared parts of the spectrum, to overcome the impact of noisy environments, illumination changes and a dynamic background. An efficient chromatic descriptor is suggested to improve activity recognition of vulnerable people. The new monitoring system is robust to distortions associated with healthcare systems and its descriptor has an improved quality of description. System performance was evaluated using a series of experimental data, the results showing the efficacy of using both spatial and temporal domains of multispectral data to deal with events that disturb monitoring systems. The chromatic descriptor achieved a better performance in comparison to traditional methods when describing daily living activities.

Human region segmentation and description methods for domiciliary healthcare monitoring using chromatic methodology

A descriptor is proposed for use in domiciliary healthcare monitoring systems. The descriptor is produced from chromatic methodology to extract robust features from the monitoring system’s images. It has superior discrimination capabilities, is robust to events that normally disturb monitoring systems, and requires less computational time and storage space to achieve recognition. A method of human region segmentation is also used with this descriptor. The performance of the proposed descriptor was evaluated using experimental data sets, obtained through a series of experiments performed in the Centre for Intelligent Monitoring Systems, University of Liverpool. The evaluation results show high recognition performance for the proposed descriptor in comparison to traditional descriptors, such as moments invariant. The results also show the effectiveness of the proposed segmentation method regarding distortion effects associated with domiciliary healthcare systems.

UHF Signal Processing and Pattern Recognition of Partial Discharge in Gas-Insulated Switchgear Using Chromatic Methodology.

The ultra-high frequency (UHF) method is widely used in insulation condition assessment. However, UHF signal processing algorithms are complicated and the size of the result is large, which hinders extracting features and recognizing partial discharge (PD) patterns. This article investigated the chromatic methodology that is novel in PD detection. The principle of chromatic methodologies in color science are introduced. The chromatic processing represents UHF signals sparsely. The UHF signals obtained from PD experiments were processed using chromatic methodology and characterized by three parameters in chromatic space (H, L, and S representing dominant wavelength, signal strength, and saturation, respectively). The features of the UHF signals were studied hierarchically. The results showed that the chromatic parameters were consistent with conventional frequency domain parameters. The global chromatic parameters can be used to distinguish UHF signals acquired by different sensors, and they reveal the propagation properties of the UHF signal in the L-shaped gas-insulated switchgear (GIS). Finally, typical PD defect patterns had been recognized by using novel chromatic parameters in an actual GIS tank and good performance of recognition was achieved.

Chromatic methodology for laser detection and ranging (LADAR) image description

Chromatic methodology for information extraction has evolved from a number of origins, some based upon human perceptions and the others on scientific and analytical approaches. From the applications of this methodology, a new robust LADAR image descriptor is proposed. This descriptor is developed to has a high discrimination capability, robust to the effects that disturb LADAR images, and requires less storage space and computational time for recognition. The performance of the proposed LADAR descriptor is evaluated using simulated LADAR images. Experimental tests are also being undertaken on the new descriptor to validate its ability with processing real LADAR images. The results show high discrimination capability for the new descriptor over the traditional techniques such as Moments descriptor, which is used to benchmark the results. The results also show the robustness of the new descriptor in the presence of noise, view change, low resolution, translation, scaling, and rotation effects.

Invariant chromatic descriptor for LADAR data processing

A new LADAR data descriptor is proposed. This descriptor is produced from the application of the chromatic methodology to extract features from the LADAR data by applying invariant spatial chromatic processors. The descriptor developed has a high discrimination capability, robust to the effects that disturb LADAR data, and requires less storage space and computational time for recognition. The performance of the proposed LADAR descriptor is evaluated using simulated LADAR data, which are generated from special software called LADAR simulator. The simulation results show high discrimination capability for the new descriptor over the traditional techniques such as Moments descriptor. This Moments descriptor is used to benchmark the results. The results also show the robustness of the proposed descriptor in the presence of noise, low resolution, view change, rotation, translation, and scaling effects.

Current Interruption Using Electromagnetically Convolved Electric Arcs in Gases

Measurements were described as current, voltage, and local dielectric strength for a current interrupter which utilized a novel form of electromagnetically convolved electric arc in air. Experiments have been performed with various interrupter structures and operational conditions. Precurrent zero-voltage extinction peaks and post-arc local breakdown voltages have been measured and are compared with values for nonconvoluted arcs in nitrogen and SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> . An empirical relationship between the extinction peak voltage and various design and operational parameters is presented. Signatures for the various interrupter structures under different operational conditions have been obtained by using a chromatic methodology and embodying the extinction peak and a local breakdown voltage.

Towards holistic chromatic intelligent monitoring of complex systems

PurposeTo introduce chromatic methods and their application to monitoring complex systems.Design/methodology/approachComplexity is introduced and the need for holistic monitoring is suggested. The chromatic methodologies are introduced and their broad‐ranging applicability is illustrated with reference to a number of diverse applications.FindingsThe generic chromatic monitoring technology has much to offer as a way of visualising, understanding, monitoring and controlling complex processes and system behaviour.Practical implicationsThe technology is leading to new ways of characterising and evaluating aspects of system behaviour, in a holistic and non‐intrusive manner, that are difficult to measure – e.g. walking behaviour of the elderly, tiredness of drivers.Originality/valueDraws out the generic basis of the chromatic methodology and how it may be applied to a wide range of complex systems and situations to predict when and where human intervention is required.

Chromatic classification of RF signals produced by electrical discharges in HV transformers

The results of investigations into the use of chromatic processing of radio frequency signals emitted from transformers known to be suffering from partial discharging are described. The work formed part of a project operated by National Grid Transco involving several industrial parties and UK universities. The chromatic processing methodology developed at the University of Liverpool has been explored for discriminating between various radio frequency signals measured with different techniques, by Glasgow Caledonian University, UMIST, the University of Southampton and the University of Bath. Such discrimination is based on three chromatic parameters: hue (dominant frequency), lightness (nominal signal strength) and saturation (effective signal bandwidth). The chromatic results are capable of yielding patterns, which appear to be associated with indications of discharges of different types and from different sources/locations.

Monitoring plasma jets containing micro particles with chromatic techniques

A description about the use of the chromatic methodology for monitoring an arc plasma jet utilised for heating micro particles for forming plasma sprayed coatings is given. It is shown that the behaviour of both the plasma and heated micro particles are distinguishable from their different coordinates on an H‐S polar map. Calibration with a standard ribbon lamp would appear feasible for tracking the temperature of the plasma heated micro particles.

Chromatic monitoring of plasma and plasma systems

Chromatic systems were originally developed for monitoring the optical emissions of plasma. This contribution describes how the technology has been utilised on low- and high-pressure plasma systems. The speed of operation of chromatic systems has allowed their use in the monitoring of fast changing plasma, such as arcs and laser plumes. The chromatic methodology has now been extended from the optical domain and is used for more general signal processing. This more general application of the chromatic method is outlined and is related to the plasma processing industry.

The Gabor transform basis of chromatic monitoring

Chromaticity based monitoring methodologies have evolved from polychromatic optical fibre based sensing systems, which was first implemented during the 1980s. The evolution has led to a recognition that such a methodology is applicable to monitoring systems more widely. It is shown that the method may be regarded as the manifestation of a particular form of signal representation by Gabor transforms. Examples of generically different practical implementations of the chromatic methodology to a range of different monitoring situations are given.