2,043 research outputs found

    Micro-doppler-based in-home aided and unaided walking recognition with multiple radar and sonar systems

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    Published in IET Radar, Sonar and Navigation. Online first 21/06/2016.The potential for using micro-Doppler signatures as a basis for distinguishing between aided and unaided gaits is considered in this study for the purpose of characterising normal elderly gait and assessment of patient recovery. In particular, five different classes of mobility are considered: normal unaided walking, walking with a limp, walking using a cane or tripod, walking with a walker, and using a wheelchair. This presents a challenging classification problem as the differences in micro-Doppler for these activities can be quite slight. Within this context, the performance of four different radar and sonar systems – a 40 kHz sonar, a 5.8 GHz wireless pulsed Doppler radar mote, a 10 GHz X-band continuous wave (CW) radar, and a 24 GHz CW radar – is evaluated using a broad range of features. Performance improvements using feature selection is addressed as well as the impact on performance of sensor placement and potential occlusion due to household objects. Results show that nearly 80% correct classification can be achieved with 10 s observations from the 24 GHz CW radar, whereas 86% performance can be achieved with 5 s observations of sonar

    A novel single-chip RF-voltage-controlled oscillator for bio-sensing applications

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    A novel interdigiated capacitance (IDC) based affinity biosensor system is presented that detects C-Reactive Protein (CRP), a risk marker for cardiovascular diseases, and transmit the information to a distance location wirelessly. The biosensor system consist of a voltage controlled oscillator (VCO) and an IDC. In the presence of CRP the capacitance of the IDC changes and this directly reflects to the oscillation frequency of the VCO. In the presence of 800 ng/ml antigen the frequency of the system shifts from 1.9438 GHz to 1.94175 GHz and with 64 ug/ml frequency shifts from 1.95975 GHz to 1.94875 GHz with -120 dBc/Hz phase noise

    Cucurbituril-based supramolecular engineered nanostructured materials

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    Cataloged from PDF version of article.Cucurbituril (CB) is a unique macrocycle with a rigid symmetrical structure, which is composed of two identical hydrophilic portals decorated with partially negatively charged carbonyl groups and a hydrophobic cavity. A number of different nanostructured materials, including nanoparticles, nanocomposites, vesicles and rods, have been prepared by taking advantage of the varying cavity size of the CB homologues, their ability to accommodate more than one guest in their cavities, their rigid symmetrical structures, as well as the water solubility of CB7. These nanostructures could find a wide range of potential applications in the areas of self-healing materials, nanomedicine, plasmonics, and nanocatalysis. Here, we review the recent progresses in the synthesis, properties and application of CB-based supramolecular engineered nanostructures, which are either constructed through CB-assisted self-assembly or from post-functionalized-CB homologues

    SAR image reconstruction by expectation maximization based matching pursuit

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    Cataloged from PDF version of article.Synthetic Aperture Radar (SAR) provides high resolution images of terrain and target reflectivity. SAR systems are indispensable in many remote sensing applications. Phase errors due to uncompensated platform motion degrade resolution in reconstructed images. A multitude of autofocusing techniques has been proposed to estimate and correct phase errors in SAR images. Some autofocus techniques work as a post-processor on reconstructed images and some are integrated into the image reconstruction algorithms. Compressed Sensing (CS), as a relatively new theory, can be applied to sparse SAR image reconstruction especially in detection of strong targets. Autofocus can also be integrated into CS based SAR image reconstruction techniques. However, due to their high computational complexity, CS based techniques are not commonly used in practice. To improve efficiency of image reconstruction we propose a novel CS based SAR imaging technique which utilizes recently proposed Expectation Maximization based Matching Pursuit (EMMP) algorithm. EMMP algorithm is greedy and computationally less complex enabling fast SAR image reconstructions. The proposed EMMP based SAR image reconstruction technique also performs autofocus and image reconstruction simultaneously. Based on a variety of metrics, performance of the proposed EMMP based SAR image reconstruction technique is investigated. The obtained results show that the proposed technique provides high resolution images of sparse target scenes while performing highly accurate motion compensation. (C) 2014 Elsevier Inc. All rights reserved

    Assessing Structural Health Monitoring Alternatives Utilizing a Value-Focused Thinking Model

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    Current Air Force operations are undergoing significant changes necessitated by increasing fiscal constraints, increasing aircraft age, and recent drawdown in personnel to perform maintenance, repair, and other necessary functions. In order to deal with these challenges, the Air Force must effectively improve current operations. This paper explores potential structural health monitoring (SHM) solutions to some of the challenges facing aircraft maintenance and repair operations. As with any problem, a variety of solutions exist and this paper explores the potential solutions and limitations of various options. Aircraft SHM is an intriguing concept with potential capability to revolutionize current Air Force maintenance operations. However, this capability needs to be balanced with the total life cycle cost associated with training personnel, and with developing, integrating, maintaining, and disposing of the SHM system. This thesis develops and implements a value-focused thinking model as a decision-making tool to analyze several potential solutions to SHM problems

    Antegradly Performed TEVAR

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    Test beam studies of the TRD prototype filled with different gas mixtures based on Xe, Kr, and Ar

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    Towards the end of LHC Run1, gas leaks were observed in some parts of the Transition Radiation Tracker (TRT) of ATLAS. Due to these leaks, primary Xenon based gas mixture was replaced with Argon based mixture in various parts. Test-beam studies with a dedicated Transition Radiation Detector (TRD) prototype were carried out in 2015 in order to understand transition radiation performance with mixtures based on Argon and Krypton. We present and discuss the results of these test-beam studies with different active gas compositions.Comment: 5 pages,12 figures, The 2nd International Conference on Particle Physics and Astrophysics (ICPPA-2016); Acknowledgments section correcte

    QUANTITATIVE EVALUATION OF PROSPECTIVE TEACHERS' VIEWS ON INCLUSIVE EDUCATION

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    In this study, pre-service teachers' views on inclusive education were evaluated from a quantitative research perspective. The survey model, one of the quantitative research designs, was used. The sample of the study consists of 482 prospective teachers studying at the same state university. The "Opinions Related to Mainstreaming Scale" was used to evaluate the views of pre-service teachers about inclusion. In the study, frequency and percentage values for each item were calculated for the data obtained from the study. In addition, Pearson correlation coefficient was calculated to determine whether there was a relationship between the sub-dimensions of the scale depending on the data collected. Although the results of the research are generally positive, the opinions of the pre-service teachers about inclusive education are inconsistent with each other, indicating that the knowledge and skill levels of the pre-service teachers about students with special needs are insufficient. It is important for a qualified inclusive education that teacher candidates who will start working in schools in the future develop positive attitudes towards inclusive education and have high levels of knowledge and skills.   Article visualizations

    A new nanocrystalline diamond-based biosensor for the detection of cardiovascular risk markers

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    In this paper, a new method to probe associative interactions of C-reactive protein (CRP) antigen with CRP antibody immobilized on a gold-interdigitated diamond electrodes was investigated. The CRP antigen detection was performed by capacitive/dielectric-constant measurements. Our results showed that the dynamic detection range using optimized conditions for a given antibody concentration (100 μg/ml) was found to be in the range 25-800 ng/ml of CRP-antigen. Biosensor developed in this study can be potentially used for detection of elevated CRP levels in suspected subjects for early diagnosis

    Some results of test beam studies of Transition Radiation Detector prototypes at CERN

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    Operating conditions and challenging demands of present and future accelerator experiments result in new requirements on detector systems. There are many ongoing activities aimed to develop new technologies and to improve the properties of detectors based on existing technologies. Our work is dedicated to development of Transition Radiation Detectors (TRD) suitable for different applications. In this paper results obtained in beam tests at SPS accelerator at CERN with the TRD prototype based on straw technology are presented. TRD performance was studied as a function of thickness of the transition radiation radiator and working gas mixture pressure
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