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Full-Text Articles in Engineering

Intrinsic Physical Layer Authentication Of Integrated Circuits, William E. Cobb, Michael A. Temple, Rusty O. Baldwin, Eric W. Garcia, Eric D. Lapse May 2015

Intrinsic Physical Layer Authentication Of Integrated Circuits, William E. Cobb, Michael A. Temple, Rusty O. Baldwin, Eric W. Garcia, Eric D. Lapse

AFIT Patents

A system and method of generating and comparing a fingerprint for an integrated circuit is provided. A sensor module captures electromagnetic emissions from the integrated circuit. A feature extraction module extracts discriminating features from the captured electromagnetic emissions. A classifier training module generates a plurality of authentication fingerprints of the integrated circuit from the extracted discriminating features creating a reference fingerprint template for the integrated circuit. The reference template for the integrated circuit is stored in a database. For authentication, the reference fingerprint template from the database is compared to the generated authentication fingerprint.


Global Navigation Satellite System Signal Decomposition And Parameterization Algorithm, Marshall E. Haker, John F. Raquet May 2015

Global Navigation Satellite System Signal Decomposition And Parameterization Algorithm, Marshall E. Haker, John F. Raquet

AFIT Patents

A method and apparatus is provided for intra-PIT signal decomposition of a signal received with RF front end hardware. The method begins by aligning a signal received by RF front end hardware into integer multiples of a duration of a pseudorandom noise code sequence. A search grid is computed based on an integer multiple of the aligned signal. A plurality of initial ray parameters associated with the computed search grid is coarsely estimated. Using the coarsely estimated plurality of initial ray parameters, a fine estimation of the plurality of initial ray parameters is initiated utilizing stochastic search and optimization techniques. …


Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton Apr 2015

Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to identify a new and unique photoactive silicon-related point defect in single crystals of rutile TiO2. The importance of this defect lies in its assignment to interstitial silicon ions and the unexpected establishment of silicon impurities as a major hole trap in TiO2. Principal g values of this new S=1/2 center are 1.9159, 1.9377, and 1.9668 with principal axes along the [¯110],[001], and [110] directions, respectively. Hyperfine structure in the EPR spectrum shows the unpaired spin interacting equally with two Ti nuclei and unequally with two Si nuclei. These silicon …


Remote Sensing Of Hidden Objects, Mark G. Hoelscher, Michael A. Marciniak Mar 2015

Remote Sensing Of Hidden Objects, Mark G. Hoelscher, Michael A. Marciniak

AFIT Patents

An apparatus and method are provided for creating an indirect image of an object. The apparatus includes a light source and an imaging system. Light emitted from the light source is reflected by a first non-specular surface toward the object. Light reflected by the object is further reflected by a second non-specular surface toward the imaging system. The imaging system is configured to create the indirect image from the reflected light.


Low Clutter Method For Bistatic Rcs Measurements, Peter J. Collins Feb 2015

Low Clutter Method For Bistatic Rcs Measurements, Peter J. Collins

AFIT Patents

A bistatic radar measurement system is provided having a radar source configured to produce a radio frequency signal. A transmitting antenna is configured to transmit the radio frequency signal toward a target. A receiving antenna is configured to receive a reflected radio frequency signal from the target. A support system is configured to support the receiving antenna. The support system includes a plurality of low scattering dielectric strings configured to orient the receiving antenna.


Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr. Feb 2015

Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr.

Faculty Publications

This paper applies a con-resistant trust mechanism to improve the performance of a communications-based special protection system to enhance its effectiveness and resiliency. Smart grids incorporate modern information technologies to increase reliability and efficiency through better situational awareness. However, with the benefits of this new technology come the added risks associated with threats and vulnerabilities to the technology and to the critical infrastructure it supports. The research in this paper uses con-resistant trust to quickly identify malicious or malfunctioning (untrustworthy) protection system nodes to mitigate instabilities. The con-resistant trust mechanism allows protection system nodes to make trust assessments based on …


Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan Jan 2015

Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan

Faculty Publications

We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ/mm2. Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 104, which is limited by both solvent …


Reconfigurable Solid-State Dye-Doped Polymer Ring Resonator Lasers, Hengky Chandrahalim, Xudong Fan Jan 2015

Reconfigurable Solid-State Dye-Doped Polymer Ring Resonator Lasers, Hengky Chandrahalim, Xudong Fan

Faculty Publications

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3′-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G) and 3,3′-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse …