On the Analysis and Detection of Flames Withan Asynchronous Spiking Image Sensor

We have investigated the capabilities of a customasynchronous spiking image sensor operating in the NearInfrared band to study flame radiation emissions, monitortheir transient activity, and detect their presence. Asynchronoussensors have inherent capabilities, i.e., good temporal resolution,high dynamic range, and low data redundancy. This makesthem competitive against infrared (IR) cameras and CMOSframe-based NIR imagers. In this paper, we analyze, discuss,and compare the experimental data measured with our sensoragainst results obtained with conventional devices. A set ofmeasurements have been taken to study the flame emissionlevels and their transient variations. Moreover, a flame detectionalgorithm, adapted to our sensor asynchronous outputs, has beendeveloped. Results show that asynchronous spiking sensors havean excellent potential for flame analysis and monitoring.Universidad de Cádiz PR2016-07Ministerio de Economía y Competitividad TEC2015-66878-C3-1-RJunta de Andalucía TIC 2012-2338Office of Naval Research (USA) N00014141035

Challenges of Video Monitoring for Phenomenological Diagnostics in Present and Future Tokamaks

With the development of heterogeneous camera networks working at different wavelengths and frame rates and covering a large surface of vacuum vessel, the visual observation of a large variety of plasma and thermal phenomena (e.g., hot spots, ELMs, MARFE, arcs, dusts, etc.) becomes possible. In the domain of machine protection, a phenomenological diagnostic is a key-element towards plasma/thermal event dangerousness assessment during real time operation. It is also of primary importance to automate the extraction and the storage of phenomena information for further off-line event retrieval and analysis, thus leading to a better use of massive image data bases for plasma physics studies. To this end, efforts have been devoted to the development of image processing algorithms dedicated to the recognition of specific events. But a need arises now for the integration of techniques developed so far in both hardware and software directions. We present in this paper our latests results in the field of real time phenomena recognition and management through our image understanding software platform. This platform has been validated on Tore Supra during operation and is under evaluation for the foreseen imaging diagnostic of ITER

Development of light-addressable potentiometric sensor systems and their applications in biotechnological environments

The simultaneous analysis of multiple analytes and spatially resolved measurements of concentration distributions with a single sensor chip are an important task in the field of (bio-)chemical sensing. Together with the miniaturisation, this is a promising step forward for applications and processes that profit from (bio-)chemical sensors. In combination with biological recognition elements, like enzymes or cells, these biosensors are becoming an interesting tool for e.g., biotechnological, medical and pharmaceutical applications. One promising sensor principle is the light-addressable potentiometric sensor (LAPS). A LAPS is a semiconductor-based potentiometric sensor that allows determining analyte concentrations of aqueous solutions in a spatially resolved manner. Therefore, it is using a focused light source to address the area of interest. The light that illuminates the local area of the LAPS chip generates a photocurrent that correlates with the local analyte concentration on the sensor surface. Based on the "state of the art", further developments of LAPS set-ups were carried out within this PhD thesis. Furthermore, by utilising enzymes and whole cells, the benefits of these LAPS set-ups for biotechnological, medical and pharmaceutical applications are demonstrated. During the present thesis, three different LAPS set-ups were developed: The first LAPS set-up makes use of a field-programmable gate array (FPGA) to drive a 4x4 light-emitting diode (LED) array that defines 16 measurement spots on the sensor-chip surface. With the help of the FPGA, the driving parameters, like light brightness, modulation amplitude and frequency can be selected individually and all LEDs can be driven concurrently. Thus, a simultaneous readout of all measurement spots is possible and chemical images of the whole sensor surface can be achieved within 200 ms. The FPGA-based LAPS set-up is used to observe the frequency behaviour of LAPS chips. In a second LAPS set-up, a commercially available organic-LED (OLED) display is used as light source. The OLED panel consists of 96x64 pixels with a pixel size of 200x200 µm and thus, an over 16 times higher lateral resolution compared to the IR-LED array. It was demonstrated that chemical images of the whole sensor surface can be obtained in 2.5 min. Since the lateral resolution of LAPS is not only specified by the light source, but also by the LAPS chip itself, the lateral resolution of the LAPS structures is characterised. Therefore, the third LAPS set-up has been developed, which utilises a single laser diode that can be moved by an XY-stage. By scanning a specially patterned LAPS chip, a lateral resolution of the LAPS structures in the range of the pixel size of the OLED display is demonstrated. Label-free imaging of biological phenomena is investigated with the FPGA-based LAPS. With the help of an enzymatic layer with the enzyme acetylcholine esterase (AChE) the detection of the neuronal transmitter acetylcholine (ACh) is demonstrated. The dynamic and static response as well as the long-term stability is characterised and compared with another semiconductor-based chemical imaging sensor based on charge-coupled devices (CCD) using the same enzymatic layer. The usage of the FPGA-based LAPS as whole-cell-based biosensor is studied with the model organism Escherichia coli. Here, the metabolic activity of the E. coli cells is investigated by determining the extracellular acidification. An immobilisation technique for embedding the microorganisms in polyacrylamide gel on the sensor surface has been developed. The immobilisation is realised in an on-chip differential arrangement by making use of the addressability of LAPS. This way, external influences such as sensor drift, temperature changes and external pH changes can be compensated. In a comparative study of the extracellular acidification rate between immobilised E. coli and E. coli that are in suspension, acidification rates in the same order were determined, demonstrating that the immobilisation does not have any influence on the metabolic activity. Further measurements with this cell-based LAPS system underline the sensitivity towards different nutrient concentrations, namely glucose. The ability to observe the extracellular acidification of microorganisms and the sensitively towards nutrient concentrations enables to detect high-order effects, like toxicity or pharmacological activity in complex analytes

Topics in Adaptive Optics

Advances in adaptive optics technology and applications move forward at a rapid pace. The basic idea of wavefront compensation in real-time has been around since the mid 1970s. The first widely used application of adaptive optics was for compensating atmospheric turbulence effects in astronomical imaging and laser beam propagation. While some topics have been researched and reported for years, even decades, new applications and advances in the supporting technologies occur almost daily. This book brings together 11 original chapters related to adaptive optics, written by an international group of invited authors. Topics include atmospheric turbulence characterization, astronomy with large telescopes, image post-processing, high power laser distortion compensation, adaptive optics and the human eye, wavefront sensors, and deformable mirrors

Design And Development Of Active Power Filter For Harmonic Minimization Using Synchronous Reference Frame (SRF)

The research for the aimed towards avoiding the waveform of the current from distorted is make the researchers interested to do that.. The controllers used in an active power filter play an important role in determining the current waveform in electrical system will smooth with a minimum of the total harmonic distortion (THD). The main purpose of this paper is to propose the controller of an active power filter based on synchronous reference frame (SRF). A model of the proposed controller has been developed using MATLAB/SIMULINK. The results of the simulation shows that the effectiveness of the proposed controller toward in reducing THD at the acceptable

An Accurate Scheme for Distance Measurement using an Ordinary Webcam

Nowadays, image processing has become one of the widely used computer aided science. Two major branches of this scientific field are image enhancement and machine vision. Machine vision has many applications and demands in robotic and defense industries. Detecting distance of objects is one of the extensive research in the defense industry and robotic industries that a lot of annual projects have been involved in this issue both inside and outside the country. So, in this paper, an accurate algorithm is presented for measuring the distance of the objects from a camera. In this method, a laser transmitter is used alongside a regular webcam. The laser light is transmitted to the desired object and then the distance of the object is calculated using image processing methods and mathematical and geometric relations. The performance of the proposed algorithm was evaluated using MATLAB software. The accuracy rate of distance detection is up to 99.62%. The results also has shown that the presented algorithms make the obstacle distance measurement more reliable. Finally, the performance of the proposed algorithm was compared with other methods from different literatures

Gaze Controlled Human-Computer Interface

The goal of the Gaze Controlled Human Computer Interface project is to design and construct a non-invasive gaze-tracking system that will determine where a user is looking on a computer screen in real time. To accomplish this, a fixed illumination source consisting of Infrared (IR) Light Emitting Diodes (LEDs) is used to produce corneal reflections on the user’s eyes. These reflections are captured with a video camera and compared to the relative location of the user’s pupils. From this comparison, a correlation matrix can be created and the approximate location of the screen that the user is looking at can be determined. The final objective is to allow the user to manipulate a cursor on the computer screen simply by looking at different boxes in a grid on the monitor. The project includes design of the hardware setup to provide a suitable environment for glint detection, image processing of the user’s eyes to determine pupil location, the implementation of a probabilistic algorithm to determine an appropriate matrix transformation, and performance analysis on various users