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Articles 1 - 8 of 8
Full-Text Articles in Engineering
A Parametric Analysis Of Microbolometer Pixel Designs, Matthew J. Dumas, Brian A. Lail
A Parametric Analysis Of Microbolometer Pixel Designs, Matthew J. Dumas, Brian A. Lail
Electrical Engineering and Computer Science Faculty Publications
As microbolometer pixel dimensions for infrared imagers continue to decrease, the need for full-wave analysis in the design process is enhanced. Using reflectance as the validation point, an electromagnetic model of a dual-layer microbolometer pixel design was created for a 25 μm pixel design, and an in-depth study of the design was performed. With this model validated, further explorations were completed with a reduced size pixel. While simulating multiple variations of specific parameters, such as bridge thickness, upper and lower cavity heights, and different absorber configurations, a new evaluation metric of dissipated power in the structure was studied. This metric, …
Denoising Medical Imagery Using A Novel Framework, Samuel Peter Kozaitis, Jeetkumar M. Mehta, S. Ponkia
Denoising Medical Imagery Using A Novel Framework, Samuel Peter Kozaitis, Jeetkumar M. Mehta, S. Ponkia
Electrical Engineering and Computer Science Faculty Publications
We proposed a novel framework that allows a method optimized for white noise to be used for denoising CT imagery. We considered low-dose x-ray CT imagery where lowering the dose of x-rays results in an increase in quantum noise. We first denoised an image independently several times using different parameters. Then, we selected pixels from those denoised images to form a final composite image. We produced results using blockmatching denoising, but in principle other methods could work within this framework, as well. The proposed method was able to better reproduce regions of low-contrast than the conventional BM3D approach.
Blood Vessel Segmentation In Magnetic Resonance Angiography Imagery, Samuel Peter Kozaitis, Raghu Chandramohan
Blood Vessel Segmentation In Magnetic Resonance Angiography Imagery, Samuel Peter Kozaitis, Raghu Chandramohan
Electrical Engineering and Computer Science Faculty Publications
Small blood vessels may be difficult to detect in magnetic resonance angiography due to the lack of blood flow caused by disease or injury. Our method, which uses a block-matching denoising approach to segment blood vessels, works well in the presence of noise. We examined extended regions of an image to determine whether they contained blood vessels by fitting a Gaussian mixture model to a region's histogram. Then, dissimilar regions were denoised separately. This approach was beneficial in low-contrast settings. It can be used to detect higher-order blood vessels that may be difficult to detect under normal conditions.
Attenuation And Bit Error Rate For Four Co-Propagating Spatially Multiplexed Optical Communication Channels Of Exactly Same Wavelength In Step Index Multimode Fibers, Syed H. Murshid, Abhijit Chakravarty
Attenuation And Bit Error Rate For Four Co-Propagating Spatially Multiplexed Optical Communication Channels Of Exactly Same Wavelength In Step Index Multimode Fibers, Syed H. Murshid, Abhijit Chakravarty
Electrical Engineering and Computer Science Faculty Publications
Spatial domain multiplexing (SDM) utilizes co-propagation of exactly the same wavelength in optical fibers to increase the bandwidth by integer multiples. Input signals from multiple independent single mode pigtail laser sources are launched at different input angles into a single multimode carrier fiber. The SDM channels follow helical paths and traverse through the carrier fiber without interfering with each other. The optical energy from the different sources is spatially distributed and takes the form of concentric circular donut shaped rings, where each ring corresponds to an independent laser source. At the output end of the fiber these donut shaped independent …
Free-Space Optical Communication Link Using Spatial Optical Encryption, Syed H. Murshid, William B. Howard, Abhijit Chakravarty
Free-Space Optical Communication Link Using Spatial Optical Encryption, Syed H. Murshid, William B. Howard, Abhijit Chakravarty
Electrical Engineering and Computer Science Faculty Publications
Free-space optical links are ideal for short-range (1 km to 3 km) communications. An innovative new technique called Spatial Optical Encryption can be used to secure laser data communications. With this technique, data can be encoded and transmitted spatially through a single fiber, and then transmitted over a free-space optical link. Different sources of data could be simultaneously sent over the same fiber. This endeavor demonstrates the design and performance issues of such a transmitter and receiver using Spatial Optical Encryption over an environmental link of 100 meters.
Optical Encryption As A Function Of Polarization In Optical Fiber Communications, Syed H. Murshid, Hari Priya Muralikrishnan, Jayachandran Tamilarasan, Abhijit Chakravarty, John H. Caulfield
Optical Encryption As A Function Of Polarization In Optical Fiber Communications, Syed H. Murshid, Hari Priya Muralikrishnan, Jayachandran Tamilarasan, Abhijit Chakravarty, John H. Caulfield
Electrical Engineering and Computer Science Faculty Publications
An optical encryption technique based on polarization property of light is proposed. Many techniques using polarization beam splitters to encrypt the signal have been proposed earlier. They are based on splitting and interference of two light signals, namely message and noise. Only by placing suitable mirrors and a second beam splitter in a suitable position, the two signals are reconstructed at the output. In this paper we report the fiber optic version of a polarization based encryption technique that also has the potential to double the data carrying capacity of the fiber. Using polarization dependent couplers in the fiber optic …
Enhanced Ulf Radiation Observed By Demeter Two Months Around The Strong 2010 Haiti Earthquake, M. A. Athanasiou, Georgios C. Anagnostopoulos, A. C. Iliopoulos, G. P. Pavlos, C. N. David
Enhanced Ulf Radiation Observed By Demeter Two Months Around The Strong 2010 Haiti Earthquake, M. A. Athanasiou, Georgios C. Anagnostopoulos, A. C. Iliopoulos, G. P. Pavlos, C. N. David
Electrical Engineering and Computer Science Faculty Publications
In this paper we study the energy of ULF electromagnetic waves that were recorded by the satellite DEMETER, during its passing over Haiti before and after a destructive earthquake. This earthquake occurred on 12 January 2010, at geographic Latitude 18.46° and Longitude 287.47°, with Magnitude 7.0 R. Specifically, we are focusing on the variations of energy of Ez-electric field component concerning a time period of 100 days before and 50 days after the strong earthquake. In order to study these variations, we have developed a novel method that can be divided in two stages: first we filter the signal, keeping …
Iii-Nitride Optoelectronic Devices: From Ultraviolet Detectors And Visible Emitters Towards Terahertz Intersubband Devices, Can Bayram
Link Foundation Energy Fellowship Reports
We review III-Nitride optoelectronic device technologies with an emphasis on recent breakthroughs achieved with the co-support of Link Foundation Energy Fellowship. We start with a brief summary of historical accomplishments and then report the state-of-the-art contributions in three key spectral regimes: Ultraviolet, Visible, and Near-, mid infrared, and terahertz. We also describe future trends and possible prospects in III-Nitride optoelectronic devices made possible with the fellow's work.