37 research outputs found

    An FPGA-based infant monitoring system

    Get PDF
    We have designed an automated visual surveillance system for monitoring sleeping infants. The low-level image processing is implemented on an embedded Xilinx’s Virtex II XC2v6000 FPGA and quantifies the level of scene activity using a specially designed background subtraction algorithm. We present our algorithm and show how we have optimised it for this platform

    Challenges and New Trends in Power Electronic Devices Reliability

    Get PDF
    The rapid increase in new power electronic devices and converters for electric transportation and smart grid technologies requires a deepanalysis of their component performances, considering all of the different environmental scenarios, overload conditions, and high stressoperations. Therefore, evaluation of the reliability and availability of these devices becomes fundamental both from technical and economicalpoints of view. The rapid evolution of technologies and the high reliability level offered by these components have shown that estimating reliability through the traditional approaches is difficult, as historical failure data and/or past observed scenarios demonstrate. With the aim topropose new approaches for the evaluation of reliability, in this book, eleven innovative contributions are collected, all focusedon the reliability assessment of power electronic devices and related components

    The Design of X-Ray Film Reader with Film Presence Detector

    Get PDF
    X-Ray viewer is a tool for observing the results of X-Ray films using ray lighting. It aims to get clearer readings of X-Ray films by radiographers and doctors. X-Ray viewers in hospitals generally cannot be carried anywhere because they use fluorescent lamps as a source of radiation and use 220 Volt AC voltage directly. So that its use is less effective and efficient because it must be connected directly to a 220 Volt AC power source and requires large power. In this regard the author wants to design an X-Ray viewer tool that can be used to read the results of X-Ray films clearly and is portable so that the device can be used anywhere because it uses a battery as a voltage source and is equipped with a presence detection sensor film in order to save energy so that the use of tools is more effective and efficient

    Challenges and new trends in power electronic devices reliability

    Get PDF
    Power electronic devices are expected to play an ever more fundamental role in unlocking the potentialities of smart power systems and in developing more electric ground and air transportation systems. The reliability of power electronic devices at different hierarchical levels (single component, single device, installation and system) becomes a crucial point in this framework, as failures may determine technical, economical and safety issues that should be carefully addressed at the design and maintenance stages. Power electronic devices are subject to thermal, electrical and mechanical stresses, which can be assessed through consolidated, traditional techniques [1,2,3,4]. However, today these devices are expected to operate under challenging environmental conditions (e.g., high altitudes in more electric aircrafts or high temperatures on photovoltaic (PV) installations), undermining the effectiveness of traditional approaches that are typically based on historical failure data, fault rates or past observed scenarios. In fact, the rapid evolution of power electronic technologies and the ever more challenging operating frameworks pose severe limitations on the trustworthiness of available reliability data, as they are typically related to incoherent operating conditions [1,2,3,4]

    Predicted Image-Capture Device Settings through Machine Learning

    Get PDF
    This publication describes an image-capture manager, which uses machine-learning algorithms modeled after neural networks to predict image-capture device settings that a user desires when capturing an image with an image-capture device. Based on training neural network models, the image-capture manager can dynamically predict and configure the image-capture device settings to match those that the user desires the image-capture device to use when capturing an image under detected conditions

    Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays

    Get PDF
    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 106 virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings

    3D Spatial Sensor

    Get PDF
    This project entitled 3D spatial sensor which is a sensor that is designed for sensing touch coordinates in 3 dimensions for 3D application such as 3Dmodeling andhumancomputer interface. The main idea of this project is to develop 3D sensor that can be used by everybody with minimal learnability and cost. 3D sensor is important to this world because our real world is a 3 dimensions world hence our interaction with computer has to be in 3 dimensions so that the real data can be inputted into the computer for further processing. However, many of the sensors for human computer interaction is limited to 2 dimensions such as keyboard, mouse and touch screen device, hence the real interaction between human and computer is limited by those devices. In this project, the development of 3D spatial sensors will be based on a novel method which make used of 2 cameras for 2 different spatial planes and a computer to calculate and derived the 3Dcoordinates from boththe image frames from the 2 cameras. Froma single touch 3D spatial sensor, additional efforts and resources will be used to develop a multiple touch 3D spatial sensors. Lastly, multiple touch 3D spatial sensors will be incorporate into different applications to demonstrate the abilities of these sensors. Hopefully the development of this device can benefit human and enhance the experience ofhuman computer interaction

    Modeling Ozark Caves with Structure-from-Motion Photogrammetry: An Assessment of Stand-Alone Photogrammetry for 3-Dimensional Cave Survey

    Get PDF
    Nearly all aspects of karst science and management begin with a map. Yet despite this fact, cave survey is largely conducted in the same archaic way that is has been for years - with a compass, tape measure, and a sketchpad. Traditional cave survey can establish accurate survey lines quickly. However, passage walls, ledges, profiles, and cross-sections are time intensive and ultimately rely on the sketcher’s experience at interpretively hand drawing these features between survey stations. This project endeavors to experiment with photogrammetry as a method of improving on traditional cave survey, while also avoiding some of the major pitfalls of terrestrial laser scanning. The proposed method allows for the creation of 3D models which capture cave wall geometry, important cave formations, as well as providing the ability to create cross sections anywhere desired. The interactive 3D cave models are produced cheaply, with equipment that can be operated in extremely confined, harsh conditions, by unpaid volunteers with little to no technical training. While the rapid advancement of photogrammetric software has led to its use in many 3D modeling applications, there is only a sparse body of research examining the use of photogrammetry as a standalone method for surveying caves. The proposed methodology uses a GoPro camera and a 1000 lumen portable floodlight to capture still images down the length of cave passages. The procedure goes against several traditional rules of thumb, both operating in the dark with a moving light source, as well as utilizing a wide angle, fish eye lens, to capture scene information that is not perpendicular to the camera\u27s field of view. Images are later processed into 3D models using Agisoft’s PhotoScan. Four caves were modeled using the method, with varying levels of success. The best results occurred in dry confined passages, while passages greater than 9 meters (30ft) in width, or those with a great deal of standing water in the floor, produced large holes. An additional experiment occurred in the University of Arkansas utility tunnel

    Development of a magneto-optical trap for CaF molecules

    Get PDF
    Laser cooling and trapping in a magneto-optical trap (MOT) have been essential to the success of cold atom physics in the last decades. Recently, the application of the same techniques to molecules has begun. The complexity of even a simple diatomic molecule makes laser cooling difficult, but promises new applications in many areas of research. In this thesis I describe the development of the first three-dimensional MOT of calcium fluoride (CaF) molecules. First, a cryogenic buffer gas source was set up, producing a pulsed beam of 9.3*10^10 molecules per steradian per pulse with forward velocities around 170 m/s. A similar source for very large molecules was set up during a 5 month internship at the University of Vienna. Next, the molecular pulse was slowed down to the capture velocity of a MOT using chirped laser slowing, resulting in about 7*10^5 CaF molecules passing through the typical MOT volume of 1 cm^3 at velocities of 15+-5 m/s. A new deceleration method, called Zeeman-Sisyphus deceleration, was also investigated. In this method molecules move through a spatially varying magnetic field and are optically pumped between low- and high-field seeking states in such as a way that they are always losing kinetic energy. The method promises to deliver more slow molecules because the molecules are guided transversely as they are decelerated. A small prototype was built and the optical pumping step was tested successfully. Finally, 7.6*10^3 CaF molecules were trapped in a MOT and cooled to a temperature of 8.5 mK. The radial trap frequency is 2 pi*130 Hz and the damping constant is beta=9.5*10^2 s^-1. The lifetime is about 100 ms and depends strongly on the scattering rate. This MOT is an an ideal starting point for a wide range of new experiments with ultracold molecules.Open Acces

    Characterizing the Exhaust Plume of the Three-Electrode Micro Pulsed Plasma Thrusters

    Get PDF
    Three-electrode micro-PPTs are a new version of two electrode micro-PPTs devices. Performance predictions and contamination expectations are essential characteristics needed by satellite designers. In order to focus on thruster specific impulse, thrust and efficiency, measuring the exhaust velocity or impulse bit and propellant consumption rate is essential. While this is not always possible to measure directly, focusing on the ejected mass from the PPT provides significant information allowing determination of these performance statistics. Specifically, focusing on exhaust angle distribution and velocity of the exhaust particles is the emphasis of this work. The results show that the three-electrode micro-PPT is more reliable than two-electrode micro-PPT and the operating energy range from 2 to 4.5 Joule is proper value to operate it. This research also shows that the angle distribution is similar to previous mass deposition distributions and the faster particles have shallower angles than that of slower particles. Finally, the energy did not give appreciable effect on angle and velocity distributions and have the Isp value range from 25 to 36 sec from the average exit velocity
    corecore