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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

An Advanced, Programmable Data Acquisition System

Wargo, William D., Eckstein, Howard 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / The MicroDAS-1000 is an airborne Data Acquisition System (DAS) designed to meet the growing needs of airframe manufacturers for extensive test data accumulation, processing and evaluation. As such, the system has been designed with emphasis on modularity, miniaturization and ease of operator usage and expansion. The MicroDAS product line includes a series of components used as building blocks to configure systems of virtually any size. The modular design of these components allows considerable latitude to the instrumentation engineer in configuring systems for simple or complex applications. The modular concept has been extended to the design of plug-in modules for different functional requirements and system applications. All units are under software control to allow rapid reconfiguration and setup as requirements for instrumentation and data gathering change.
112

Design and Development of Data Acquisition/Processing and Communication Interface for Radar Front-End

Käll, Daniel, Lannerhjelm, Emelie January 2016 (has links)
This thesis follows the design process of a back end. The purpose of this back end is to interface a radar front end, developed by Acreo Swedish ICT, and stream it’s digitalized output to a PC using Universal Serial Bus (USB) 3.0. The front end, which acts as a basis for this project, is a Frequency Modulated Continuous Wave (FMCW) radar which is connected to the back end by a header. The header connects the digitalized radar signals, together with two SPI-buses and a few GPIO pins. Thus, enabling configuration and set up of the front end board via a PC. The result of the thesis is a data acquisition board that can be used to interface with the front end. The implemented back end features an FPGA to handle the ADC data from the front end, so the board has DSP capabilities, but can also stream the raw radar data. The FPGA is connected to a USB 3.0 controller through a 32-bit parallel interface. The configuration of the front end, via the produced board, is verified in it’s functionality and can be controlled by a PC using a simple GUI. Commands are sent through the USB 3.0 controller to a front end controller which handles the communication. Since getting the hardware functional has been the main objective of the thesis, the project has been deemed to be successful. The final result is a back end radar prototype, which has the requested core hardware functionalities. In addition to this, the prototype has the capacity to act as a platform for further expanding its functionality after a hand over of the project to Acreo Swedish ICT.
113

Tremor quantification and parameter extraction

Bejugam, Santosh January 2011 (has links)
Tremor is a neuro degenerative disease causing involuntary musclemovements in human limbs. There are many types of tremor that arecaused due to the damage of nerve cells that surrounds thalamus of thefront brain chamber. It is hard to distinguish or classify the tremors asthere are many reasons behind the formation of specific category, soevery tremor type is named behind its frequency type. Propermedication for the cure by physician is possible only when the disease isidentified.Because of the argument given in the above paragraph, there is a needof a device or a technique to analyze the tremor and for extracting theparameters associated with the signal. These extracted parameters canbe used to classify the tremor for onward identification of the disease.There are various diagnostic and treatment monitoring equipment areavailable for many neuromuscular diseases. This thesis is concernedwith the tremor analysis for the purpose of recognizing certain otherneurological disorders. A recording and analysis system for human’stremor is developed.The analysis was performed based on frequency and amplitudeparameters of the tremor. The Fast Fourier Transform (FFT) and higherorderspectra were used to extract frequency parameters (e.g., peakamplitude, fundamental frequency of tremor, etc). In order to diagnosesubjects’ condition, classification was implemented by statisticalsignificant tests (t‐test).
114

Acquisition and Mining of the Whole Mouse Brain Microstructure

Kwon, Jae-Rock 2009 August 1900 (has links)
Charting out the complete brain microstructure of a mammalian species is a grand challenge. Recent advances in serial sectioning microscopy such as the Knife- Edge Scanning Microscopy (KESM), a high-throughput and high-resolution physical sectioning technique, have the potential to finally address this challenge. Nevertheless, there still are several obstacles remaining to be overcome. First, many of these serial sectioning microscopy methods are still experimental and are not fully automated. Second, even when the full raw data have been obtained, morphological reconstruction, visualization/editing, statistics gathering, connectivity inference, and network analysis remain tough problems due to the unprecedented amounts of data. I designed a general data acquisition and analysis framework to overcome these challenges with a focus on data from the C57BL/6 mouse brain. Since there has been no such complete microstructure data from any mammalian species, the sheer amount of data can overwhelm researchers. To address the problems, I constructed a general software framework for automated data acquisition and computational analysis of the KESM data, and conducted two scientific case studies to discuss how the mouse brain microstructure from the KESM can be utilized. I expect the data, tools, and studies resulting from this dissertation research to greatly contribute to computational neuroanatomy and computational neuroscience.
115

Sub-Nyquist Rate Sampling Data Acquisition Systems Based on Compressive Sensing

Chen, Xi 2011 May 1900 (has links)
This dissertation presents the fundamental theory and design procedure of the sub-Nyquist rate sampling receiver front-end that exploits signal sparsity by employing Compressive Sensing (CS) techniques. The CS receiver serves as an Analog-to-Information Conversion (AIC) system that works at sampling rates much lower than the Nyquist rate. The performance of a parallel path CS front-end structure that employs current mode sampling techniques is quantified analytically. Useful and fundamental design guidelines that are unique to CS are provided based on the analytical tools. Simulations with IBM 90nm CMOS process verify the theoretical derivations and the circuit implementations. Based on these results, it is shown that instantaneous receiver signal bandwidth of 1.5 GHz and 44 dB of signal to noise plus distortion ratio (SNDR) are achievable in simulations assuming 0.5 ps clock jitter is present. The ADC and front-end core power consumption is estimated to be 120.8 mW. The front-end is fabricated with IBM 90nm CMOS process, and a BPSK sub-Nyquist rate communication system is realized as a prototype in the testing. A 1.25 GHz reference clock with 4.13 ps jitter variance is employed in the test bench. The signal frequency, phase and amplitude can be correctly reconstructed, and the maximum signal SNR obtained in the testing is 40 dB with single tone input and 30 dB with multi-tones test. The CS system has a better FOM than state-of-art Nyquist rate data acquisition systems taking into account the estimated PLL power.
116

Moving Data Analysis into the Acquisition Hardware

Buckley, Dave 10 1900 (has links)
ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / Data acquisition for flight test is typically handled by dedicated hardware which performs specific functions and targets specific interfaces and buses. Through the use of an FPGA state machine based design approach, performance and robustness can be guaranteed. Up to now sufficient flexibility has been provided by allowing the user to configure the hardware depending on the particular application. However by allowing custom algorithms to be run on the data acquisition hardware, far greater control and flexibility can be offered to the flight test engineer. As the volume of the acquired data increases, this extra control can be used to vastly reduce the amount of data to be recorded or telemetered. Also real-time analysis of test points can now be done where post processing would previously have been required. This paper examines examples of data acquisition, recording and processing and investigates where data reduction and time savings can be achieved by enabling the flight test engineer to run his own algorithms on the hardware.
117

A New Approach to Time Sync for Telemetry System

Lu, Chun, Kung, Changchun, Song, Jian 10 1900 (has links)
ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Instead of using a single data acquisition device, the distribute data acquisition system is broadly applied for onboard flight testing now. Therefore, the sync of data acquisition in varied devices and the real time data transportation have become the most important factors in a telemetry system. This paper presents a new approach to clock synchronization in a real time transportation network for a data acquisition system by using IRIG time code and an inner timer through network time recovery technique. This paper also illustrates how to keep the synchronization and continuity of a time tag used by each device through a precise estimation method for the difference of time resources and local inner timers.
118

Gas Phase Etching of Silicon Dioxide Films

Montano, Gerardo January 2006 (has links)
The gas phase etching of thermal silicon dioxide films was investigated with in situ Fourier Transformed Infrared Spectroscopy (FTIR) and ex situ X-ray Photoelectron Spectroscopy (XPS). The initiation process, the bulk etching of the oxide, and the termination mechanism were characterized as a function of reactant concentration, temperature, and pressure. The experiments were carried out in a custom made vessel with a gas panel and a data acquisition and control system (DA&C) capable of lowering flow and pressure disturbances originated by reactant introduction. The FTIR technique used to monitor the reaction in real time allowed distinguishing reactions that initiated in a gas/solid regime from reactions that started in a gas/liquid/solid regime. This study was focused on the gas/solid initiation process in order to expand the general assumption in published works that a condensed layer is previously required to initiate and sustain the reaction. It was found in this investigation that, depending on the experimental parameters, the water layer is not always a requisite for the initiation of the reaction but a consequence of the etching process. The FTIR data also showed the role in the initiation process of gas phase heterogeneous associated species, specifically (HF)H₂O and (HF)₂H₂O. After the initiation period, the experimental conditions determined the amount of water present on the surface of the sample, which in turn determined the local environment of the reaction and by extension the etching species. Reactions developing in a gas/solid regime were found to be slow, with etching rates of less than 1 °A/sec. Contrarily, reactions taking place in a gas/liquid/solid regime reached etching rates of 100 °A/sec, a maximum value determined by transport limitations. The condensed layer was found to be especially sensitive to temperature since a variation of 15 ° C changed the local environment from gas/liquid/solid to gas/solid. Finally, it was corroborated through the XPS analysis that the removal process in the gas phase leaves the silicon surfaces with high fluorine and oxygen concentrations in the form of SiFₓ and SiOH.
119

Development of a computer interface for a clamp-on ultrasonic flow meter

Sundin, Peter January 2007 (has links)
The section for volume, flow and temperature at SP Technical Research Institute of Sweden performs measurements of volume, flow and temperature in liquids. Flow meters are best calibrated in its installation to take sources of error like installation effects and the medium into account. If this can be done without having to place measurement equipment inside the pipe it will mean several practical benefits. Since many years, clamp-on ultrasonic flow meters have been available on the market. But even with today’s improvements they still have a measurement uncertainty in the measurements that is five to ten times too big to make them useful as references for calibration procedures. This thesis focuses on analysis, using reversed engineering, of an existing clamp-on ultrasonic flow meter. The goal of the project is evaluation and further development of the ultrasonic flow meter’s existing computer interface with the purpose of offering the option of using Microsoft Excel and Visual Basic for data acquisition and measurement of the flow rate of liquids.
120

Gray Code Composite Pattern Structured Light Illumination

Gupta, Pratibha 01 January 2007 (has links)
Structured light is the most common 3D data acquisition technique used in the industry. Traditional Structured light methods are used to obtain the 3D information of an object. Multiple patterns such as Phase measuring profilometry, gray code patterns and binary patterns are used for reliable reconstruction. These multiple patterns achieve non-ambiguous depth and are insensitive to ambient light. However their application is limited to motion much slower than their projection time. These multiple patterns can be combined into a single composite pattern based on the modulation and demodulation techniques and used for obtaining depth information. In this way, the multiple patterns are applied simultaneously and thus support rapid object motion. In this thesis we have combined multiple gray coded patterns to form a single Gray code Composite Pattern. The gray code composite pattern is projected and the deformation produced by the target object is captured by a camera. By demodulating these distorted patterns the 3D world coordinates are reconstructed.

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