Showing papers on "Signal published in 2016"

TianQin: a space-borne gravitational wave detector

Abstract: TianQin is a proposal for a space-borne detector of gravitational waves in the millihertz frequencies. The experiment relies on a constellation of three dragfree spacecraft orbiting the Earth. Inter-spacecraft laser interferometry is used to monitor the distances between the test masses. The experiment is designed to be capable of detecting a signal with high confidence from a single source of gravitational waves within a few months of observing time. We describe the preliminary mission concept for TianQin, including the candidate source and experimental designs. We present estimates for the major constituents of the experiment's error budget and discuss the project's overall feasibility. Given the current level of technological readiness, we expect TianQin to be flown in the second half of the next decade.

A wearable chemical-electrophysiological hybrid biosensing system for real-time health and fitness monitoring

Abstract: Flexible, wearable sensing devices can yield important information about the underlying physiology of a human subject for applications in real-time health and fitness monitoring. Despite significant progress in the fabrication of flexible biosensors that naturally comply with the epidermis, most designs measure only a small number of physical or electrophysiological parameters, and neglect the rich chemical information available from biomarkers. Here, we introduce a skin-worn wearable hybrid sensing system that offers simultaneous real-time monitoring of a biochemical (lactate) and an electrophysiological signal (electrocardiogram), for more comprehensive fitness monitoring than from physical or electrophysiological sensors alone. The two sensing modalities, comprising a three-electrode amperometric lactate biosensor and a bipolar electrocardiogram sensor, are co-fabricated on a flexible substrate and mounted on the skin. Human experiments reveal that physiochemistry and electrophysiology can be measured simultaneously with negligible cross-talk, enabling a new class of hybrid sensing devices.

Optoelectronically innervated soft prosthetic hand via stretchable optical waveguides

Abstract: Because of their continuous and natural motion, fluidically powered soft actuators have shown potential in a range of robotic applications, including prosthetics and orthotics. Despite these advantages, robots using these actuators require stretchable sensors that can be embedded in their bodies for sophisticated functions. Presently, stretchable sensors usually rely on the electrical properties of materials and composites for measuring a signal; many of these sensors suffer from hysteresis, fabrication complexity, chemical safety and environmental instability, and material incompatibility with soft actuators. Many of these issues are solved if the optical properties of materials are used for signal transduction. We report the use of stretchable optical waveguides for strain sensing in a prosthetic hand. These optoelectronic strain sensors are easy to fabricate, are chemically inert, and demonstrate low hysteresis and high precision in their output signals. As a demonstration of their potential, the photonic strain sensors were used as curvature, elongation, and force sensors integrated into a fiber-reinforced soft prosthetic hand. The optoelectronically innervated prosthetic hand was used to conduct various active sensation experiments inspired by the capabilities of a real hand. Our final demonstration used the prosthesis to feel the shape and softness of three tomatoes and select the ripe one.

Signal and power communication system positioned on a rotatable shaft

Abstract: A surgical instrument assembly can comprise a handle including an electric motor, a shaft assembly including a drive member, and a magnet configured to generate a magnetic field The surgical instrument assembly further comprises, one, a rotatable output shaft operably coupled with the electric motor and the drive member and, two, a wire coil wound around the output shaft which is positioned in the magnetic field The wire coil is rotated within the magnetic field when the output shaft is rotated about a longitudinal axis which induces a current in the wire coil The surgical instrument assembly further comprises a strain gauge mounted to the output shaft configured to detect strain created within the output shaft and, in addition, a circuit mounted to the output shaft, wherein the circuit and/or the strain gauge is powered by the current induced in the wire coil

Enabling UAV cellular with millimeter-wave communication: potentials and approaches

Abstract: To support high data rate urgent or ad hoc communications, we consider mmWave UAV cellular networks and the associated challenges and solutions. To enable fast beamforming training and tracking, we first investigate a hierarchical structure of beamforming codebooks and design of hierarchical codebooks with different beam widths via sub-array techniques. We next examine the Doppler effect as a result of UAV movement and find that the Doppler effect may not be catastrophic when high gain directional transmission is used. We further explore the use of mmWave spatial-division multiple access and demonstrate its clear advantage in improving the cellular network capacity. We also explore different ways of dealing with signal blockage and point out that possible adaptive UAV cruising algorithms would be necessary to counteract signal blockage. Finally, we identify a close relationship between UAV positioning and directional mmWave user discovery, where update of the former may directly impact the latter and vice versa.

A fully reconfigurable photonic integrated signal processor

Abstract: Photonic signal processing has been considered a solution to overcome the inherent electronic speed limitations. Over the past few years, an impressive range of photonic integrated signal processors have been proposed, but they usually offer limited reconfigurability, a feature highly needed for the implementation of large-scale general-purpose photonic signal processors. Here, we report and experimentally demonstrate a fully reconfigurable photonic integrated signal processor based on an InP–InGaAsP material system. The proposed photonic signal processor is capable of performing reconfigurable signal processing functions including temporal integration, temporal differentiation and Hilbert transformation. The reconfigurability is achieved by controlling the injection currents to the active components of the signal processor. Our demonstration suggests great potential for chip-scale fully programmable all-optical signal processing. Scientists experimentally demonstrate a fully configurable photonic integrated signal processor based on an InP–InGaAs material system by controlling the injection currents to the active components.

Single-Channel Multi-Speaker Separation using Deep Clustering

Abstract: Deep clustering is a recently introduced deep learning architecture that uses discriminatively trained embeddings as the basis for clustering. It was recently applied to spectrogram segmentation, resulting in impressive results on speaker-independent multi-speaker separation. In this paper we extend the baseline system with an end-to-end signal approximation objective that greatly improves performance on a challenging speech separation. We first significantly improve upon the baseline system performance by incorporating better regularization, larger temporal context, and a deeper architecture, culminating in an overall improvement in signal to distortion ratio (SDR) of 10.3 dB compared to the baseline of 6.0 dB for two-speaker separation, as well as a 7.1 dB SDR improvement for three-speaker separation. We then extend the model to incorporate an enhancement layer to refine the signal estimates, and perform end-to-end training through both the clustering and enhancement stages to maximize signal fidelity. We evaluate the results using automatic speech recognition. The new signal approximation objective, combined with end-to-end training, produces unprecedented performance, reducing the word error rate (WER) from 89.1% down to 30.8%. This represents a major advancement towards solving the cocktail party problem.

Radar Signal Processing for Elderly Fall Detection: The future for in-home monitoring

Abstract: Radar is considered an important technology for health monitoring and fall detection in elderly assisted living due to a number of attributes not shared by other sensing modalities. In this article, we describe the signal processing algorithms and techniques involved in elderly fall detection using radar. A human?s radar signal returns differ in their Doppler characteristics, depending on the nature of the human gross motor activities. These signals are nonstationary in nature, inviting time-frequency analysis in both its linear and bilinear aspects, to play a fundamental role in motion identification, including fall features determination and classification. This article employs real fall data to demonstrate the success of existing detection algorithms as well as to report on some of the challenges facing technology developments for fall detection.

Remote distributed antenna system

Abstract: A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.

Passive electrical coupling device and methods for use therewith

Abstract: Aspects of the subject disclosure may include, for example, a coupling device includes a circuit that receives a signal At least one passive electrical circuit element generates an electromagnetic field in response to the signal A portion of the electromagnetic field is guided by a surface of a transmission medium to propagate as a guided electromagnetic wave longitudinally along the transmission medium Other embodiments are disclosed

An Efficient Threshold Prediction Scheme for Wavelet Based ECG Signal Noise Reduction Using Variable Step Size Firefly Algorithm

Abstract: Electrocardiographic (ECG) signal is significant to diagnose cardiac arrhythmia among various biological signals. The accurate analysis of noisy Electrocardiographic (ECG) signal is very motivating challenge. Prior to automated analysis, the noises present in ECG signal need to be eliminated for accurate diagnosis. Many researchers have been reported different methods for denoising the ECG signal in recent years. In this paper, an optimized threshold mechanism is proposed for wavelet based medical signal noise reduction. This scheme is based on a variable step size firefly algorithm (VSSFA) in dual tree complex wavelet scheme, in which the VSSFA is utilized for threshold optimization. This approach is evaluated on several normal and abnormal ECG signals of MIT/BIH arrhythmia database, by artificially adding white Gaussian noises with variation of 5dB and 10dB. Simulation result illustrate that the proposed system is well performance in various noise level, and obtains better visual quality compare with other methods.

Multi-petahertz electronic metrology

Abstract: Investigations using single-cycle intense optical fields to drive electron motion in bulk silicon dioxide show that the light-induced electric currents extend in frequency up to about 8 petahertz. The speed of electronics, and hence of computing, is limited by the frequencies of the electric currents that are used. Light fields can induce and manipulate electric currents at vastly higher frequencies than are achievable in conventional devices, and Eleftherios Goulielmakis and colleagues now extend this approach to reach an even faster regime. They use single-cycle intense optical fields to drive electron motion in the bulk of silicon dioxide and show that the light-induced intraband electric currents extend in frequency up to about eight petahertz. This demonstration of real-time access to the dynamic nonlinear conductivity of silicon dioxide, with the ability to directly probe and control the intraband currents on attosecond timescales, establishes intense light fields as a platform for multi-petahertz coherent electronics and points to new opportunities for fundamental studies of electron dynamics in condensed matter. The frequency of electric currents associated with charge carriers moving in the electronic bands of solids determines the speed limit of electronics and thereby that of information and signal processing1. The use of light fields to drive electrons promises access to vastly higher frequencies than conventionally used, as electric currents can be induced and manipulated on timescales faster than that of the quantum dephasing of charge carriers in solids2. This forms the basis of terahertz (1012 hertz) electronics in artificial superlattices2, and has enabled light-based switches3,4,5 and sampling of currents extending in frequency up to a few hundred terahertz. Here we demonstrate the extension of electronic metrology to the multi-petahertz (1015 hertz) frequency range. We use single-cycle intense optical fields (about one volt per angstrom) to drive electron motion in the bulk of silicon dioxide, and then probe its dynamics by using attosecond (10−18 seconds) streaking6,7 to map the time structure of emerging isolated attosecond extreme ultraviolet transients and their optical driver. The data establish a firm link between the emission of the extreme ultraviolet radiation and the light-induced intraband, phase-coherent electric currents that extend in frequency up to about eight petahertz, and enable access to the dynamic nonlinear conductivity of silicon dioxide. Direct probing, confinement and control of the waveform of intraband currents inside solids on attosecond timescales establish a method of realizing multi-petahertz coherent electronics. We expect this technique to enable new ways of exploring the interplay between electron dynamics and the structure of condensed matter on the atomic scale.

Method and apparatus for use with a radio distributed antenna system having an in-band reference signal

Abstract: Aspects of the subject disclosure may include, for example, receiving, by a network element of a distributed antenna system, a reference signal, a control channel and a first modulated signal at a first carrier frequency, the first modulated signal including first communications data provided by a base station and directed to a mobile communication device The instructions in the control channel direct the network element of the distributed antenna system to convert the first modulated signal at the first carrier frequency to the first modulated signal in a first spectral segment The reference signal is received at an out of band frequency relative to the control channel Other embodiments are disclosed

Method and apparatus for use with a radio distributed antenna system having a clock reference

Abstract: Aspects of the subject disclosure may include, for example, receiving, by a network element of a distributed antenna system, a clock signal, a control channel and a first modulated signal at a first carrier frequency, the first modulated signal including first communications data provided by a base station and directed to a mobile communication device. The clock signal synchronizes timing of digital control channel processing by the network element to recover instructions from the control channel. The instructions in the control channel direct the network element of the distributed antenna system to convert the first modulated signal at the first carrier frequency to the first modulated signal in a first spectral segment. Other embodiments are disclosed.

Method and apparatus for use with a radio distributed antenna system having an ultra-wideband control channel

Abstract: Aspects of the subject disclosure may include, for example, receiving, by a network element of a distributed antenna system, a reference signal, an ultra- wideband control channel and a first modulated signal at a first carrier frequency, the first modulated signal including first communications data provided by a base station and directed to a mobile communication device. The instructions in the ultra- wideband control channel direct the network element of the distributed antenna system to convert the first modulated signal at the first carrier frequency to the first modulated signal in a first spectral segment. The reference signal is received at an in-band frequency relative to the control channel. Other embodiments are disclosed.

Apparatus and methods for generating non-interfering electromagnetic waves on an insulated transmission medium

Abstract: Aspects of the subject disclosure may include, receiving a plurality of communication signals, and generating, according to the plurality of communication signals, signals that induce a plurality of electromagnetic waves bound at least in part to a dielectric material. Each electromagnetic wave of the plurality of electromagnetic waves conveys at least one communication signal of the plurality of communication signals, and the plurality of electromagnetic waves has a multiplexing configuration that reduces an interference between the plurality of electromagnetic waves. Other embodiments are disclosed.

Apparatus and methods for launching guided waves via circuits

Abstract: Aspects of the subject disclosure may include, for example, a system having a plurality of transmitters for launching, according to a signal, instances of first electromagnetic waves having different phases to induce propagation of a second electromagnetic wave at an interface of a transmission medium, the second electromagnetic wave having a non-fundamental wave mode and a non-optical operating frequency, wherein the plurality of transmitters has a corresponding plurality of antennas. A reflective plate is spaced a distance behind the plurality of antennas relative to a direction of the propagation of the second electromagnetic wave. Other embodiments are disclosed.

Distributed antenna system and methods for use therewith

Abstract: Aspects of the subject disclosure may include, for example, a method, includes coordinating relay transmission of a modulated signal via relay links of a distributed antenna system to reduce an accumulated forwarding delay in forwarding the modulated signal through the relay links. One of the relay links of the distributed antenna system reconverts the spectral segment of the modulated signal for transmission to a communication device to which the modulated signal is directed.

Apparatus and methods for measuring signals

Abstract: Aspects of the subject disclosure may include, a system that obtains a group of signals that are each representative of a corresponding one of a group of electromagnetic waves, analyzes the group of signals to determine signal characteristics, and determines, according to the signal characteristics, predicted characteristics for a communication signal that is to be transmitted by a circuit. Other embodiments are disclosed.

Apparatus and methods for launching guided waves via plural waveguide systems

Abstract: Aspects of the subject disclosure may include, for example, a system having a first plurality of transmitters for launching according to a signal, first electromagnetic waves, and a second plurality of transmitters for launching, according to the signal, second electromagnetic waves. The first electromagnetic waves and the second electromagnetic waves combine at an interface of a transmission medium to induce a propagation of a third electromagnetic wave, the third electromagnetic wave having a non-fundamental wave mode and a non-optical operating frequency, and wherein the second plurality of transmitters are spaced apart from the first plurality of transmitters in a direction of propagation of the third electromagnetic wave. Other embodiments are disclosed.

Apparatus and methods for launching electromagnetic waves having a certain electric field structure

Abstract: Aspects of the subject disclosure may include, receiving a signal, and launching, according to the signal, an electromagnetic wave along a transmission medium, where the electromagnetic wave propagates along the transmission medium without requiring an electrical return path, and where the electromagnetic wave has a phase delay profile that is dependent on an azimuth angle about an axis of the transmission medium. Other embodiments are disclosed.

Apparatus and methods for launching guided waves via an antenna

Abstract: Aspects of the subject disclosure may include, for example, a system having an antenna for launching, according to a signal, a first electromagnetic wave to induce a propagation of a second electromagnetic wave along a transmission medium, the second electromagnetic wave having a non-fundamental wave mode and a non-optical operating frequency. A reflective plate is spaced a distance behind the antenna relative to a direction of the propagation of the second electromagnetic wave. Other embodiments are disclosed.

ESPRIT—Estimation of Signal Parameters via Rotational lnvariance Techniques

Abstract: An approach to the general problem of signal parameter estimation is described. The algorithm differs from its predecessor in that a total least-squares rather than a standard least-squares criterion is used. Although discussed in the context of direction-of-arrival estimation, ESPRIT can be applied to a wide variety of problems including accurate detection and estimation of sinusoids in noise. It exploits an underlying rotational invariance among signal subspaces induced by an array of sensors with a translational invariance structure. The technique, when applicable, manifests significant performance and computational advantages over previous algorithms such as MEM, Capon's MLM, and MUSIC. >

Effects of neutron-star dynamic tides on gravitational waveforms within the effective-one-body approach

Abstract: Extracting the unique information on ultradense nuclear matter from the gravitational waves emitted by merging neutron-star binaries requires robust theoretical models of the signal. We develop a novel effective-one-body waveform model that includes, for the first time, dynamic (instead of only adiabatic) tides of the neutron star as well as the merger signal for neutron-star–black-hole binaries. We demonstrate the importance of the dynamic tides by comparing our model against new numerical-relativity simulations of nonspinning neutron-star–black-hole binaries spanning more than 24 gravitational-wave cycles, and to other existing numerical simulations for double neutron-star systems. Furthermore, we derive an effective description that makes explicit the dependence of matter effects on two key parameters: tidal deformability and fundamental oscillation frequency.

Baseline correction of vibration acceleration signals with inconsistent initial velocity and displacement

Abstract: This study improves upon the traditional polynomial detrending method in order to correct the vibration acceleration signals with inconsistent initial velocity and displacement more rationally and efficiently. When numerical integration of recorded acceleration signals using assumed initial velocity and displacement values (which are generally inconsistent with real values) is performed, baseline shift or drift phenomenon can arise in velocity and displacement curves obtained. Baseline correction must be performed if an inconsistent acceleration signal is to be used in dynamic analyses. Polynomial detrending is generally used to remove unreasonable trends in time series, but the consistency among acceleration, velocity, and displacement has not received sufficient attention. The traditional polynomial detrending method is improved by purposefully removing the shifted trends in velocity and displacement. Two inconsistent vibration signals are selected to be corrected using both the traditional method and t...

Quantum optical circulator controlled by a single chirally coupled atom

Abstract: A circulator is a passive three- or four-port device that routes signals according to a simple protocol: If the ports are numbered in ascending order, a signal that enters the circulator through port 1, 2, 3, or 4 exits it through port 2, 3, 4, or 1, respectively. Scheucher et al. demonstrate an integrated optical circulator that operates by using the internal quantum state of a single atom (see the Perspective by Munro and Nemoto). Moreover, the routing can be reversed by flipping the atomic spin. Such an integrated optical device may be important for routing and processing quantum information in scalable integrated optical circuits. Science , this issue p. [1577][1]; see also p. [1532][2] [1]: /lookup/doi/10.1126/science.aaj2118 [2]: /lookup/doi/10.1126/science.aal3163

Wireless power transmission apparatus and wireless power transmission method

Abstract: The embodiment relates to a wireless power transmission apparatus and a wireless power transmission method The wireless power transmission apparatus includes a first power converting unit to generate high-frequency AC signals; a second power converting unit to generate low-frequency AC signals; a first coil receiving the high-frequency AC signals and transmitting a wireless power through a first power transmission scheme; a second coil receiving the low-frequency AC signals and transmitting the wireless power through a second power transmission scheme; and a control unit to control the first and second coils, wherein the control unit is configured to transmit a detection signal for the first power transmission scheme to a wireless power reception apparatus through the first coil, detect a reception of a first response signal corresponding to the first detection signal during a first predetermined time, determine a power transmission scheme of the wireless power reception apparatus as the first power transmission scheme in response to a detection of the first response signal, and deactivate the first power converting unit in response to no detection of the first response signal