1,937 research outputs found
Spectral Domain RF Fingerprinting for 802.11 Wireless Devices
The increase in availability and reduction in cost of commercial communication devices (e.g. IEEE compliant such as 802.11, WiFi, 802.16, Bluetooth etc.) has increased wireless user exposure and the need for techniques to properly identify/classify signals for increased security measures. Communication device emissions include intentional modulation that enables correct device operation. Hardware and environmental factors alter the ideal response and induce unintentional modulation effects. If these effects (features) are sufficiently unique, it becomes possible to identify a device using its fingerprint, with potential discrimination of not only the manufacturer but possibly the serial number for a given manufacturer. Many techniques in many domains have been investigated to extract features, identify a fingerprint, classify signals, and each technique has certain benefits and limitations. Previous AFIT research has demonstrated the effectiveness of RF Fingerprinting using 802.11A signals with 1) spectral correlation on Power Spectral Density (PSD) fingerprints, 2) Multiple Discriminant Analysis/Maximum Likelihood (MDA/ML) classification with fingerprints obtained from Time Domain (TD) and Wavelet Domain (WD) statistical features. Performance \gain , defined as the difference in Signal-to-Noise ratio (SNR) required to achieve comparable classification performance, has been used to demonstrate considerable improvement. Spectral Domain (SD) fingerprinting uses PSD features for device discrimination. Results presented here show some improvement over the WD approach (gain ≈ 3 dB) and significant improvement over the TD approach (gain ≈ 8 dB)
Interview with Marjorie Risser, Class of 1944
Oral history interview with Illinois State Normal University alumnus Marjorie Munns Risser, Class of 1944. The interview was conducted on November 3, 1979, by student Denise Cook of ISU Alumni Services. They discuss changes in the student body size, extracurricular activities, and memorable faculty.https://ir.library.illinoisstate.edu/aoh/1010/thumbnail.jp
The WA Goldfields Aboriginal Community Antenatal Program: A community midwifery initiative
Aim: To investigate the acceptability and satisfaction with the Aboriginal Community Antenatal Program by staff in the program and partner agencies. Design: A Strengths, Weaknesses, Opportunities and Threats framework guided the research and data collection methods. Mixed methodology was used, accessing qualitative and quantitative information from data bases, program and supporting agency staff. Quantitative data were analysed through a social sciences statistical package. Qualitative data were identified through questionnaires and analysed using thematic analysis. Setting: Remote Aboriginal communities in the Goldfields region of Western Australia. Participant sources: Twenty two participants including program and supporting agency staff. Main outcome measures: This study measures acceptability and satisfaction of program antenatal and pre-conception activities by program staff and partner agencies. Results: Qualitative results indicate acceptability and satisfaction with the program, identifying a range of organisational, staffing, cultural and interagency issues relating to a model of service provision. Quantitative data suggested positive program outputs from service delivery. Conclusion: Findings suggest the Aboriginal Community Antenatal Program and partner agencies are increasing provision of community based pre-conception and antenatal health services and enhancing collaboration between a range of health provider agencies, with partnerships between Aboriginal and non-Aboriginal program staff contributing to an emerging model of community antenatal care
Raman Quantum Memory with Built-In Suppression of Four-wave Mixing Noise
Quantum memories are essential for large-scale quantum information networks.
Along with high efficiency, storage lifetime and optical bandwidth, it is
critical that the memory add negligible noise to the recalled signal. A common
source of noise in optical quantum memories is spontaneous four-wave mixing. We
develop and implement a technically simple scheme to suppress this noise
mechanism by means of quantum interference. Using this scheme with a Raman
memory in warm atomic vapour we demonstrate over an order of magnitude
improvement in noise performance. Furthermore we demonstrate a method to
quantify the remaining noise contributions and present a route to enable
further noise suppression. Our scheme opens the way to quantum demonstrations
using a broadband memory, significantly advancing the search for scalable
quantum photonic networks.Comment: 6 pages, 5 figures plus Supplementary Materia
Utilizing reamer irrigator aspirator (RIA) autograft for opening wedge high tibial osteotomy: A new surgical technique and report of three cases
AbstractINTRODUCTIONThe lateral closing wedge high tibial osteotomy (HTO) was popularized by Coventry in the 1960s. In the 1990s the medial opening wedge osteotomy gained popularity because it could achieve greater valgus correction and it did not require dissociation of the fibula from the tibia, an important consideration when treating varus knees with lateral and posterolateral ligament deficiencies (Noyes’ double-varus and triple-varus knees). However, it has the disadvantage of requiring bone graft to fill bony defects. Recently, the reamer-irrigator-aspirator (RIA; Synthes, Paoli, PA) system was developed, and as a result of this procedure, a large amount of usable autogenous bone graft can be collected safely for use. To our knowledge, there is no published series combining opening wedge HTO with the use of RIA obtained autogenous bone graft.PRESENTATION OF CASEWe present a novel technique in which a series of three patients underwent opening wedge HTO using ipsilateral, retrograde femur RIA graft to fill the bone defect. All patients had satisfactory clinical and radiologic outcomes following the new technique at latest follow up.DISCUSSIONOpening wedge high tibial osteotomy is a well-documented and accepted orthopedic procedure, however, has the disadvantage of requiring varying amounts of bone graft. Traditionally, iliac crest or tricortical allograft have been the grafting modalities of choice, however both have inherent drawbacks to their use. In our series, the use of RIA autograft is a safe and reliable harvest technique for high tibial osteotomy, providing abundant and quality autogenous bone graft.CONCLUSIONAll three of our patients achieved radiographic union with high clinical patient satisfaction without any major complications. We feel this novel technique is a safe and acceptable operative solution grafting opening wedge osteotomies about the knee
Tissue tolerance: an essential but elusive trait for salt-tolerant crops
For a plant to persist in saline soil, osmotic adjustment of all plant cells is essential. The more salt-tolerant species accumulate Na+ and Cl– to concentrations in leaves and roots that are similar to the external solution, thus allowing energy-efficient osmotic adjustment. Adverse effects of Na+ and Cl– on metabolism must be avoided, resulting in a situation known as ‘tissue tolerance’. The strategy of sequestering Na+ and Cl– in vacuoles and keeping concentrations low in the cytoplasm is an important contributor to tissue tolerance. Although there are clear differences between species in the ability to accommodate these ions in their leaves, it remains unknown whether there is genetic variation in this ability within a species. This viewpoint considers the concept of tissue tolerance, and how to measure it. Four conclusions are drawn: (1) osmotic adjustment is inseparable from the trait of tissue tolerance; (2) energy-efficient osmotic adjustment should involve ions and only minimal organic solutes; (3) screening methods should focus on measuring tolerance, not injury; and (4) high-throughput protocols that avoid the need for control plants and multiple Na+ or Cl-
measurements should be developed. We present guidelines to identify useful genetic variation in tissue tolerance that can be harnessed for plant breeding of salt tolerance
Theory of noise suppression in {\Lambda}-type quantum memories by means of a cavity
Quantum memories, capable of storing single photons or other quantum states
of light, to be retrieved on-demand, offer a route to large-scale quantum
information processing with light. A promising class of memories is based on
far-off-resonant Raman absorption in ensembles of -type atoms. However
at room temperature these systems exhibit unwanted four-wave mixing, which is
prohibitive for applications at the single-photon level. Here we show how this
noise can be suppressed by placing the storage medium inside a moderate-finesse
optical cavity, thereby removing the main roadblock hindering this approach to
quantum memory.Comment: 10 pages, 3 figures. This paper provides the theoretical background
to our recent experimental demonstration of noise suppression in a
cavity-enhanced Raman-type memory ( arXiv:1510.04625 ). See also the related
paper arXiv:1511.05448, which describes numerical modelling of an atom-filled
cavity. Comments welcom
Identification of compounds that cause axonal dieback without cytotoxicity in dorsal root ganglia explants and intervertebral disc cells with potential to treat pain via denervation
Low back pain, knee osteoarthritis, and cancer patients suffer from chronic pain. Aberrant nerve growth into intervertebral disc, knee, and tumors, are common pathologies that lead to these chronic pain conditions. Axonal dieback induced by capsaicin (Caps) denervation has been FDA-approved to treat painful neuropathies and knee osteoarthritis but with shortterm efficacy and discomfort. Herein, we propose to evaluate pyridoxine (Pyr), vincristine sulfate (Vcr) and ionomycin (Imy) as axonal dieback compounds for denervation with potential to alleviate pain. Previous literature suggests Pyr, Vcr, and Imy can cause undesired axonal degeneration, but no previous work has evaluated axonal dieback and cytotoxicity on adult rat dorsal root ganglia (DRG) explants. Thus, we performed axonal dieback screening using adult rat DRG explants in vitro with Caps as a positive control and assessed cytotoxicity. Imy inhibited axonal outgrowth and slowed axonal dieback, while Pyr and Vcr at high concentrations produced significant reduction in axon length and robust axonal dieback within three days. DRGs treated with Caps, Vcr, or Imy had increased DRG cytotoxicity compared to matched controls, but overall cytotoxicity was minimal and at least 88% lower compared to lysed DRGs. Pyr did not lead to any DRG cytotoxicity. Further, neither Pyr nor Vcr triggered intervertebral disc cell death or affected cellular metabolic activity after three days of incubation in vitro. Overall, our findings suggest Pyr and Vcr are not toxic to DRGs and intervertebral disc cells, and there is potential for repurposing these compounds for axonal dieback compounds to cause local denervation and alleviate pain
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