This paper presents a flexible parylene micro-electrodearray (MEA) that records Electrocardiograms (ECG) from the Zebrafish heart in-vivo, covering both the ventricle and atrium area. ECG is a powerful tool for monito...
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ISBN:
(纸本)9781479935086
This paper presents a flexible parylene micro-electrodearray (MEA) that records Electrocardiograms (ECG) from the Zebrafish heart in-vivo, covering both the ventricle and atrium area. ECG is a powerful tool for monitoring the heart activity. While ECG technology for human has been well established, this is not true for zebrafish. Our previous work demonstrated baseline ECG recording from zebrafish using MEMS MEAs [1, 2]. However, due to the body structure and small size of the zebrafish (e.g., the heart is roughly 1mm in size and its atrium is buried deep in the thoracic cavity, Fig. 1b.), all zebrafish ECGs to date were only recorded from the ventricular side, making it easy to miss important electrophysiological signals from the atrium. To our knowledge, ECG from the atrial angles in Zebrafish has not yet been demonstrated. This work describes a flexible MEA implant (i.e., specially designed according to zebrafish heart anatomy) that records from both the ventricular and the atrial angles. Furthermore, to demonstrate that this device is useful for heart regeneration monitoring, our work also includes ECG recording before and after laser damage on the ventricle (532nm green light, 32mJ/mm(2), 20mJ total). This chosen energy level of laser pulse is first calibrated using ablated heart histology by EthD-1 florescence staining. The post injury ECG data clearly show ST-wave depression, an indication of ventricular abnormal repolarization state. In addition, repeated missing T-wave is observed from the channels recorded from the atrial angles, which indicate abnormalities in atrial physiology. A hypothesis is that since absorption coefficient of 532nm light in body tissue is rather low, the laser beam penetrated deeply in the heart and created damage deep in the atrium as well as the ventricle. The MEA presented here shows potential for an effective tool to study long-term adult zebrafish heart development and regeneration.
Ultra Wideband (UWB) technology is a potential technology for short range communication with high data rate and relatively small amount of transmitted power. The coexistence of UWB systems with other narrowband system...
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ISBN:
(纸本)9781479953653
Ultra Wideband (UWB) technology is a potential technology for short range communication with high data rate and relatively small amount of transmitted power. The coexistence of UWB systems with other narrowband systems make UWB systems prone to interference because of low transmission power limits. In this paper, we propose a technique to mitigate the effect of interference from IEEE 802.11a wireless local area network (WLAN) using method of template waveform processing. We use Fourier transform to approximate the template at the receiver. We approximate the template by two methods as a sum of subcarriers at different frequencies except the interfering frequencies and original template with removal of interfering frequencies. We compare the proposed interference mitigation technique with Gabor approximation method proposed by K. Ohno and T. Ikegami to show better interference rejection using proposed technique.
Modern radar development is driven by an evolving and expanding range of threats. The low end of the threat spectrum is composed of small, slow-moving targets such as UAVs or small surface vessels. At the high end of ...
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Modern radar development is driven by an evolving and expanding range of threats. The low end of the threat spectrum is composed of small, slow-moving targets such as UAVs or small surface vessels. At the high end of the threat spectrum there is an increasing number of very fast missiles, up to the level of (Tactical) Ballistic Missiles. Furthermore, the mission environment has evolved as well, which is illustrated on the naval side by increased operations in littoral environments, often in an asymmetric warfare setting. Active Electronically Scanned Array (AESA) radar systems are uniquely suited to operate in these operational and threat environments, where the flexibility and redundancy of AESA systems give them an edge over more conventional solutions. Active array systems have been in use for more than a decade now (e.g., the APAR X-band system). Typically, these systems use RF beamforming or 1D Digital Beamforming (DBF). Recent advances in technology have made it possible to extend these beamforming concepts to full 2D digital beamforming, also known as Dual Axis Multi-beam. This results in additional flexibility and possibilities on a system level. This paper describes the underlying technology evolution and the added functionality and flexibility that is achieved with such systems.
Commercial OFDM signals of opportunity have been studied for numerous radar applications, including SAR imaging. This paper demonstrates the utility of long term evolution (LTE), digital video broadcast (DVB), and dig...
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Commercial OFDM signals of opportunity have been studied for numerous radar applications, including SAR imaging. This paper demonstrates the utility of long term evolution (LTE), digital video broadcast (DVB), and digital audio broadcast (DAB) signals for producing passive SAR images by employing a previously derived OFDM matched filter model. Both full matched filters and partially matched filters (using only a priori known signal features) are considered for generating phase history from collected receiver data. small-scale, experimental SAR images are produced illustrating the merits of the processing schemes and signals of opportunity.
This article examines the detection of faults in electrical systems, particularly those using asynchronous machines. First, the process of failure will be characterized, relevant symptoms will be defined and based on ...
This article examines the detection of faults in electrical systems, particularly those using asynchronous machines. First, the process of failure will be characterized, relevant symptoms will be defined and based on those processes and symptoms, a model of those malfunctions will be obtained. second, the development of diagnosis of the machine will be shown. As studies of malfunctions in electrical systems could only rely on a small amount of experimental data, it has been essential to provide ourselves with simulation tools which allowed us to characterize the faulty behavior. Fault detection use signalprocessing techniques in known operating phases (fixed speed).
Due to complex subsurface situation, echo signals surveyed with Ground Penetration Radar (GPR) often contain a lot of clutters, including direct-coupling wave, random noises and multiples. Existence of these clutters ...
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Due to complex subsurface situation, echo signals surveyed with Ground Penetration Radar (GPR) often contain a lot of clutters, including direct-coupling wave, random noises and multiples. Existence of these clutters submerges measured feature signals of rock structures with GPR, so suppression of them is often essential conduct for rock feature extraction. For extracting rockmass structure features from surveyed GPR datasignals, sparse representation (SR) of the signals is an invaluable scheme with a small number of elementary signals from over-complete dictionary. In processing GPR signaldata for extraction of rock structure and fracture features, this paper investigates sole Curvelet transform or matching pursuit (MP) for directcoupling wave and clutter suppression and feature extraction, and analyzes their limitations. By modeling ground penetrating radar signals with sparse decomposition, the method can achieve better results. Experimental results with simulation as well as real field data show that the proposed sparse decomposition achieves efficient signal representation and yields discriminative features for geological interpretation.
Banks collect large amount of historical records corresponding to millions of credit cards operations, but, unfortunately, only a small portion, if any, is open access. This is because, e.g., the records include confi...
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Banks collect large amount of historical records corresponding to millions of credit cards operations, but, unfortunately, only a small portion, if any, is open access. This is because, e.g., the records include confidential customer data and banks are afraid of public quantitative evidence of existing fraud operations. This paper tackles this problem with the application of surrogate techniques to generate new synthetic credit card data. The quality of the surrogate multivariate data is guaranteed by constraining them to have the same covariance, marginal distributions, and joint distributions as the original multivariate data. The performance of fraud detection algorithms (in terms of receiver operating characteristic (ROC) curves) using a varying proportion of real and surrogate data is tested. We demonstrate the feasibility of surrogates in a real scenario considering very low false alarm and high disproportion between legitimate and fraud operations.
Traditional satellite technologies integrate solar panels, thermo mechanical subsystems, power management, dataprocessing and harness subsystems together in a late stage of design. More recently this approach has bec...
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ISBN:
(纸本)9781479916191
Traditional satellite technologies integrate solar panels, thermo mechanical subsystems, power management, dataprocessing and harness subsystems together in a late stage of design. More recently this approach has become inefficient and its limitation can easily be overcome with modern manufacturing technologies. This paper proposes an innovative approach to embed power, signalprocessing and harness together with thermo mechanical subsystem(s) and when required, solar panels. The approach has been developed for the AraMiS architecture for low-cost modular satellites, but it can easily be adapted to other architectures, missions and spacecraft sizes. The architecture consists of tiles or panel bodies containing solar panels on exterior side and all necessary electronic subsystems on the interior side. The proposed approach uses very thin commercial PCBs (0.2 or 0.3mm thick) as the lateral skins for honeycomb structure. The interior side also contains commercial tile processors and plug & play connectors for any desired subsystem placement. The processors implement common functionalities for signalprocessing, data communication and control operation. The interior side can also host power conversion, for an improved fault-tolerant interface of solar panels with the power management subsystem. A high-performance power distribution bus has also been tested, for a distributed approach to satellite power management. The proposed design uses exclusively the UML diagrams for illustration purpose and software handling of housekeeping data.
We introduce a novel Multi-Carrier Code Division Multiple Access (MC-CDMA) system, where random sparse signatures are deployed in the frequency domain. data symbols transmitted from base station (BS) to mobile station...
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We introduce a novel Multi-Carrier Code Division Multiple Access (MC-CDMA) system, where random sparse signatures are deployed in the frequency domain. data symbols transmitted from base station (BS) to mobile stations (MSs) are drawn from discrete finite alphabets, such as M-QAM constellations. Transmitter-based precoding is introduced so as to allow simple despreading followed by single-user detection at MSs. A power-efficient non-linear precoding optimization problem is formulated by imposing minimum Symbol Error Probability (SEP) targets at MSs. We first elaborate on how to translate the SEP targets into exact constraint regions on noiseless received components at MSs. With relaxation on the exact regions, a tractable convex problem is obtained. A dual-decomposition-based algorithm is then developed to accommodate parallel processors to perform precoding calculation. The signature sparsity turns out to be vital to reduce interprocessor communication overhead and computational complexity for precoding. The scheme proposed offers considerable transmit power reduction compared with the conventional zero-forcing precoder.
Unstructured detectors such as KGLRT, ACE and AMF are widely applied for target detection in hyperspectral imagery (HSI). However, conventional global and local approaches construct background model without considerin...
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ISBN:
(纸本)9781479962853
Unstructured detectors such as KGLRT, ACE and AMF are widely applied for target detection in hyperspectral imagery (HSI). However, conventional global and local approaches construct background model without considering the contamination caused by anomalies and suspected targets. This paper proposes a local ACE algorithm based on the minimum covariance determinant (MCD) estimator. In the proposed algorithm, a spectral angle based clustering method is applied to the whitened hyperspectral data to form several disjoint clusters over the whole image. Then for each cluster, the robust estimations of its background statistics are obtained using the MCD estimator. Finally, the ACE detector is applied to each pixel utilizing the robust background statistics of the cluster. With experimental results on two different real datasets, the superiority of the proposed algorithm is demonstrated.
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