17 research outputs found

    Real-Time RF-DNA Fingerprinting of ZigBee Devices Using a Software-Defined Radio with FPGA Processing

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    ZigBee networks are increasingly popular for use in medical, industrial, and other applications. Traditional security techniques for ZigBee networks are based on presenting and verifying device bit-level credentials (e.g. keys). While historically effective, ZigBee networks remain vulnerable to attack by any unauthorized rogue device that can obtain and present bit-level credentials for an authorized device. This research focused on utilizing a National Instruments (NI) X310 Software-Defined Radio (SDR) hosting an on-board Field Programmable Gate Array (FPGA). The demonstrations included device discrimination assessments using like-model ZigBee AVR RZUSBstick devices and included generating RF fingerprints in real-time, as an extension to AFIT\u27s RF-DNA fingerprinting work. The goal was to develop a fingerprinting process that was both 1) effective at discriminating between like-model ZigBee devices and 2) efficient for implementation in FPGA hardware. As designed and implemented, the full-dimensional FPGA fingerprint generator only utilized approximately 7% of the X310 Kintex-7 FPGA resources. The full-dimensional fingerprinting performance of using only 7% of FPGA resources demonstrates the feasibility for real-time RF-DNA fingerprint generation and like-model ZigBee device discrimination using an SDR platform

    Power, Food and Agriculture: Implications for Farmers, Consumers and Communities

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    Development of Bone and Cartilage in Tissue-Engineered Human Middle Phalanx Models

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    Human middle phalanges were tissue-engineered with midshaft scaffolds of poly(L-lactide-ɛ-caprolactone) [P(LA-CL)], hydroxyapatite-P(LA-CL), or β-tricalcium phosphate-P(LA-CL) and end plate scaffolds of bovine chondrocyte-seeded polyglycolic acid. Midshafts were either wrapped with bovine periosteum or left uncovered. Constructs implanted in nude mice for up to 20 weeks were examined for cartilage and bone development as well as gene expression and protein secretion, which are important in extracellular matrix (ECM) formation and mineralization. Harvested 10- and 20-week constructs without periosteum maintained end plate cartilage but no growth plate formation. They also consisted of chondrocytes secreting type II collagen and proteoglycan, and they were composed of midshaft regions devoid of bone. In all periosteum-wrapped constructs at like times, end plate scaffolds held chondrocytes elaborating type II collagen and proteoglycan and cartilage growth plates resembling normal tissue. Chondrocyte gene expression of type II collagen, aggrecan, and bone sialoprotein varied depending on midshaft composition, presence of periosteum, and length of implantation time. Periosteum produced additional cells, ECM, and mineral formation within the different midshaft scaffolds. Periosteum thus induces midshaft development and mediates chondrocyte gene expression and growth plate formation in cartilage regions of phalanges. This work is important for understanding developmental principles of tissue-engineered phalanges and by extension those of normal growth plate cartilage and bone
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