WorldWideScience

Sample records for high-bandwidth communication rates

  1. Three-Axis Attitude Estimation With a High-Bandwidth Angular Rate Sensor

    Science.gov (United States)

    Bayard, David S.; Green, Joseph J.

    2013-01-01

    A continuing challenge for modern instrument pointing control systems is to meet the increasingly stringent pointing performance requirements imposed by emerging advanced scientific, defense, and civilian payloads. Instruments such as adaptive optics telescopes, space interferometers, and optical communications make unprecedented demands on precision pointing capabilities. A cost-effective method was developed for increasing the pointing performance for this class of NASA applications. The solution was to develop an attitude estimator that fuses star tracker and gyro measurements with a high-bandwidth angular rotation sensor (ARS). An ARS is a rate sensor whose bandwidth extends well beyond that of the gyro, typically up to 1,000 Hz or higher. The most promising ARS sensor technology is based on a magnetohydrodynamic concept, and has recently become available commercially. The key idea is that the sensor fusion of the star tracker, gyro, and ARS provides a high-bandwidth attitude estimate suitable for supporting pointing control with a fast-steering mirror or other type of tip/tilt correction for increased performance. The ARS is relatively inexpensive and can be bolted directly next to the gyro and star tracker on the spacecraft bus. The high-bandwidth attitude estimator fuses an ARS sensor with a standard three-axis suite comprised of a gyro and star tracker. The estimation architecture is based on a dual-complementary filter (DCF) structure. The DCF takes a frequency- weighted combination of the sensors such that each sensor is most heavily weighted in a frequency region where it has the lowest noise. An important property of the DCF is that it avoids the need to model disturbance torques in the filter mechanization. This is important because the disturbance torques are generally not known in applications. This property represents an advantage over the prior art because it overcomes a weakness of the Kalman filter that arises when fusing more than one rate

  2. Designing and implementing Multibeam Smart Antennas for high bandwidth UAV communications using FPGAs

    Science.gov (United States)

    Porcello, J. C.

    Requirements for high bandwidth UAV communications are often necessary in order to move large amounts of mission information to/from Users in real-time. The focus of this paper is antenna beamforming for point-to-point, high bandwidth UAV communications in order to optimize transmit and receive power and support high data throughput communications. Specifically, this paper looks at the design and implementation of Multibeam Smart Antennas to implement antenna beamforming in an aerospace communications environment. The Smart Antenna is contrasted against Fast Fourier Transform (FFT) based beamforming in order to quantify the increase in both computational load and FPGA resources required for multibeam adaptive signal processing in the Smart Antenna. The paper begins with an overall discussion of Smart Antenna design and general beamforming issues in high bandwidth communications. Important design considerations such as processing complexity in a constrained Size, Weight and Power (SWaP) environment are discussed. The focus of the paper is with respect to design and implementation of digital beamforming wideband communications waveforms using FPGAs. A Multibeam Time Delay element is introduced based on Lagrange Interpolation. Design data for Multibeam Smart Antennas in FPGAs is provided in the paper as well as reference circuits for implementation. Finally, an example Multibeam Smart Antenna design is provided based on a Xilinx Virtex-7 FPGA. The Multibeam Smart Antenna example design illustrates the concepts discussed in the paper and provides design insight into Multibeam Smart Antenna implementation from the point of view of implementation complexity, required hardware, and overall system performance gain.

  3. Low latency, high bandwidth data communications between compute nodes in a parallel computer

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2010-11-02

    Methods, parallel computers, and computer program products are disclosed for low latency, high bandwidth data communications between compute nodes in a parallel computer. Embodiments include receiving, by an origin direct memory access (`DMA`) engine of an origin compute node, data for transfer to a target compute node; sending, by the origin DMA engine of the origin compute node to a target DMA engine on the target compute node, a request to send (`RTS`) message; transferring, by the origin DMA engine, a predetermined portion of the data to the target compute node using memory FIFO operation; determining, by the origin DMA engine whether an acknowledgement of the RTS message has been received from the target DMA engine; if the an acknowledgement of the RTS message has not been received, transferring, by the origin DMA engine, another predetermined portion of the data to the target compute node using a memory FIFO operation; and if the acknowledgement of the RTS message has been received by the origin DMA engine, transferring, by the origin DMA engine, any remaining portion of the data to the target compute node using a direct put operation.

  4. A Study of an Optical Lunar Surface Communications Network with High Bandwidth Direct to Earth Link

    Science.gov (United States)

    Wilson, K.; Biswas, A.; Schoolcraft, J.

    2011-01-01

    Analyzed optical DTE (direct to earth) and lunar relay satellite link analyses, greater than 200 Mbps downlink to 1-m Earth receiver and greater than 1 Mbps uplink achieved with mobile 5-cm lunar transceiver, greater than 1Gbps downlink and greater than 10 Mpbs uplink achieved with 10-cm stationary lunar transceiver, MITLL (MIT Lincoln Laboratory) 2013 LLCD (Lunar Laser Communications Demonstration) plans to demonstrate 622 Mbps downlink with 20 Mbps uplink between lunar orbiter and ground station; Identified top five technology challenges to deploying lunar optical network, Performed preliminary experiments on two of challenges: (i) lunar dust removal and (ii)DTN over optical carrier, Exploring opportunities to evaluate DTN (delay-tolerant networking) over optical link in a multi-node network e.g. Desert RATS.

  5. Health care using high-bandwidth communication to overcome distance and time barriers for the Department of Defense

    Science.gov (United States)

    Mun, Seong K.; Freedman, Matthew T.; Gelish, Anthony; de Treville, Robert E.; Sheehy, Monet R.; Hansen, Mark; Hill, Mac; Zacharia, Elisabeth; Sullivan, Michael J.; Sebera, C. Wayne

    1993-01-01

    Image management and communications (IMAC) network, also known as picture archiving and communication system (PACS) consists of (1) digital image acquisition, (2) image review station (3) image storage device(s), image reading workstation, and (4) communication capability. When these subsystems are integrated over a high speed communication technology, possibilities are numerous in improving the timeliness and quality of diagnostic services within a hospital or at remote clinical sites. Teleradiology system uses basically the same hardware configuration together with a long distance communication capability. Functional characteristics of components are highlighted. Many medical imaging systems are already in digital form. These digital images constitute approximately 30% of the total volume of images produced in a radiology department. The remaining 70% of images include conventional x-ray films of the chest, skeleton, abdomen, and GI tract. Unless one develops a method of handling these conventional film images, global improvement in productivity in image management and radiology service throughout a hospital cannot be achieved. Currently, there are two method of producing digital information representing these conventional analog images for IMAC: film digitizers that scan the conventional films, and computed radiography (CR) that captures x-ray images using storage phosphor plate that is subsequently scanned by a laser beam.

  6. High-Bandwidth Hybrid Sensor (HYSENS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA has demonstrated the primary innovation of combining a precision MEMS gyro (BAE SiRRS01) with a high bandwidth angular rate sensor, ATA's ARS-14 resulting in a...

  7. High-Bandwidth AFM-Based Rheology Reveals that Cartilage is Most Sensitive to High Loading Rates at Early Stages of Impairment

    Science.gov (United States)

    Nia, Hadi Tavakoli; Bozchalooi, Iman S.; Li, Yang; Han, Lin; Hung, Han-Hwa; Frank, Eliot; Youcef-Toumi, Kamal; Ortiz, Christine; Grodzinsky, Alan

    2013-01-01

    Utilizing a newly developed atomic-force-microscopy-based wide-frequency rheology system, we measured the dynamic nanomechanical behavior of normal and glycosaminoglycan (GAG)-depleted cartilage, the latter representing matrix degradation that occurs at the earliest stages of osteoarthritis. We observed unique variations in the frequency-dependent stiffness and hydraulic permeability of cartilage in the 1 Hz-to-10 kHz range, a frequency range that is relevant to joint motions from normal ambulation to high-frequency impact loading. Measurement in this frequency range is well beyond the capabilities of typical commercial atomic force microscopes. We showed that the dynamic modulus of cartilage undergoes a dramatic alteration after GAG loss, even with the collagen network still intact: whereas the magnitude of the dynamic modulus decreased two- to threefold at higher frequencies, the peak frequency of the phase angle of the modulus (representing fluid-solid frictional dissipation) increased 15-fold from 55 Hz in normal cartilage to 800 Hz after GAG depletion. These results, based on a fibril-reinforced poroelastic finite-element model, demonstrated that GAG loss caused a dramatic increase in cartilage hydraulic permeability (up to 25-fold), suggesting that early osteoarthritic cartilage is more vulnerable to higher loading rates than to the conventionally studied “loading magnitude”. Thus, over the wide frequency range of joint motion during daily activities, hydraulic permeability appears the most sensitive marker of early tissue degradation. PMID:23561529

  8. Ultra-low Noise, High Bandwidth, 1550nm HgCdTe APD Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To meet the demands of future high-capacity free space optical communications links, a high bandwidth, near infrared (NIR), single photon sensitive optoelectronic...

  9. Ultra-high bandwidth quantum secured data transmission

    Science.gov (United States)

    Dynes, James F.; Tam, Winci W.-S.; Plews, Alan; Fröhlich, Bernd; Sharpe, Andrew W.; Lucamarini, Marco; Yuan, Zhiliang; Radig, Christian; Straw, Andrew; Edwards, Tim; Shields, Andrew J.

    2016-10-01

    Quantum key distribution (QKD) provides an attractive means for securing communications in optical fibre networks. However, deployment of the technology has been hampered by the frequent need for dedicated dark fibres to segregate the very weak quantum signals from conventional traffic. Up until now the coexistence of QKD with data has been limited to bandwidths that are orders of magnitude below those commonly employed in fibre optic communication networks. Using an optimised wavelength divisional multiplexing scheme, we transport QKD and the prevalent 100 Gb/s data format in the forward direction over the same fibre for the first time. We show a full quantum encryption system operating with a bandwidth of 200 Gb/s over a 100 km fibre. Exploring the ultimate limits of the technology by experimental measurements of the Raman noise, we demonstrate it is feasible to combine QKD with 10 Tb/s of data over a 50 km link. These results suggest it will be possible to integrate QKD and other quantum photonic technologies into high bandwidth data communication infrastructures, thereby allowing their widespread deployment.

  10. Ultra-high bandwidth quantum secured data transmission

    Science.gov (United States)

    Dynes, James F.; Tam, Winci W-S.; Plews, Alan; Fröhlich, Bernd; Sharpe, Andrew W.; Lucamarini, Marco; Yuan, Zhiliang; Radig, Christian; Straw, Andrew; Edwards, Tim; Shields, Andrew J.

    2016-01-01

    Quantum key distribution (QKD) provides an attractive means for securing communications in optical fibre networks. However, deployment of the technology has been hampered by the frequent need for dedicated dark fibres to segregate the very weak quantum signals from conventional traffic. Up until now the coexistence of QKD with data has been limited to bandwidths that are orders of magnitude below those commonly employed in fibre optic communication networks. Using an optimised wavelength divisional multiplexing scheme, we transport QKD and the prevalent 100 Gb/s data format in the forward direction over the same fibre for the first time. We show a full quantum encryption system operating with a bandwidth of 200 Gb/s over a 100 km fibre. Exploring the ultimate limits of the technology by experimental measurements of the Raman noise, we demonstrate it is feasible to combine QKD with 10 Tb/s of data over a 50 km link. These results suggest it will be possible to integrate QKD and other quantum photonic technologies into high bandwidth data communication infrastructures, thereby allowing their widespread deployment. PMID:27734921

  11. Modulator-Based, High Bandwidth Optical Links for HEP Experiments

    CERN Document Server

    Underwood, D G; Fernando, W S; Stanek, R W

    2012-01-01

    As a concern with the reliability, bandwidth and mass of future optical links in LHC experiments, we are investigating CW lasers and light modulators as an alternative to VCSELs. These links will be particularly useful if they utilize light modulators which are very small, low power, high bandwidth, and are very radiation hard. We have constructed a test system with 3 such links, each operating at 10 Gb/s. We present the quality of these links (jitter, rise and fall time, BER) and eye mask margins (10GbE) for 3 different types of modulators: LiNbO3-based, InP-based, and Si-based. We present the results of radiation hardness measurements with up to ~1012 protons/cm2 and ~65 krad total ionizing dose (TID), confirming no single event effects (SEE) at 10 Gb/s with either of the 3 types of modulators. These optical links will be an integral part of intelligent tracking systems at various scales from coupled sensors through intra-module and off detector communication. We have used a Si-based photonic transceiver to...

  12. High-bandwidth hybrid quantum repeater.

    Science.gov (United States)

    Munro, W J; Van Meter, R; Louis, Sebastien G R; Nemoto, Kae

    2008-07-25

    We present a physical- and link-level design for the creation of entangled pairs to be used in quantum repeater applications where one can control the noise level of the initially distributed pairs. The system can tune dynamically, trading initial fidelity for success probability, from high fidelity pairs (F=0.98 or above) to moderate fidelity pairs. The same physical resources that create the long-distance entanglement are used to implement the local gates required for entanglement purification and swapping, creating a homogeneous repeater architecture. Optimizing the noise properties of the initially distributed pairs significantly improves the rate of generating long-distance Bell pairs. Finally, we discuss the performance trade-off between spatial and temporal resources.

  13. Bullet: high bandwidth data dissemination using an overlay mesh

    OpenAIRE

    Kostic, D.; Rodriguez, A.; J. Albrecht; Vahdat, A.

    2003-01-01

    In recent years, overlay networks have become an effective alternative to IP multicast for efficient point to multipoint communication across the Internet. Typically, nodes self-organize with the goal of forming an efficient overlay tree, one that meets performance targets without placing undue burden on the underlying network. In this paper, we target high-bandwidth data distribution from a single source to a large number of receivers. Applications include large-file transfers and real-time ...

  14. High bandwidth synaptic communication and frequency tracking in human neocortex

    NARCIS (Netherlands)

    Testa-Silva, Guilherme; Verhoog, Matthijs B; Linaro, Daniele; de Kock, Christiaan P J; Baayen, Johannes C; Meredith, Rhiannon M; De Zeeuw, Chris I; Giugliano, Michele; Mansvelder, Huibert D

    2014-01-01

    Neuronal firing, synaptic transmission, and its plasticity form the building blocks for processing and storage of information in the brain. It is unknown whether adult human synapses are more efficient in transferring information between neurons than rodent synapses. To test this, we recorded from c

  15. Network Bandwidth Utilization Forecast Model on High Bandwidth Network

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Wucherl; Sim, Alex

    2014-07-07

    With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology, our forecast model reduces computation time by 83.2percent. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.

  16. Knee implant imaging at 3 Tesla using high-bandwidth radiofrequency pulses.

    Science.gov (United States)

    Bachschmidt, Theresa J; Sutter, Reto; Jakob, Peter M; Pfirrmann, Christian W A; Nittka, Mathias

    2015-06-01

    To investigate the impact of high-bandwidth radiofrequency (RF) pulses used in turbo spin echo (TSE) sequences or combined with slice encoding for metal artifact correction (SEMAC) on artifact reduction at 3 Tesla in the knee in the presence of metal. Local transmit/receive coils feature increased maximum B1 amplitude, reduced SAR exposition and thus enable the application of high-bandwidth RF pulses. Susceptibility-induced through-plane distortion scales inversely with the RF bandwidth and the view angle, hence blurring, increases for higher RF bandwidths, when SEMAC is used. These effects were assessed for a phantom containing a total knee arthroplasty. TSE and SEMAC sequences with conventional and high RF bandwidths and different contrasts were tested on eight patients with different types of implants. To realize scan times of 7 to 9 min, SEMAC was always applied with eight slice-encoding steps and distortion was rated by two radiologists. A local transmit/receive knee coil enables the use of an RF bandwidth of 4 kHz compared with 850 Hz in conventional sequences. Phantom scans confirm the relation of RF bandwidth and through-plane distortion, which can be reduced up to 79%, and demonstrate the increased blurring for high-bandwidth RF pulses. In average, artifacts in this RF mode are rated hardly visible for patients with joint arthroplasties, when eight SEMAC slice-encoding steps are applied, and for patients with titanium fixtures, when TSE is used. The application of high-bandwidth RF pulses by local transmit coils substantially reduces through-plane distortion artifacts at 3 Tesla. © 2014 Wiley Periodicals, Inc.

  17. VISA IB Ultra-High Bandwidth, High Gain SASE FEL

    CERN Document Server

    Andonian, Gerard; Murokh, Alex; Pellegrini, Claudio; Reiche, Sven; Rosenzweig, J B; Travish, Gil

    2004-01-01

    The results of a high energy-spread SASE FEL experiment, the intermediary experiment linking the VISA I and VISA II projects, are presented. A highly chirped beam (~1.7%) was transported without correction of longitudinal aberrations in the ATF dogleg, and injected into the VISA undulator. The output FEL radiation displayed an uncharacteristicly large bandwidth (~11%) with extremely stable lasing and measured energy of about 2 microJoules. Start-to-end simulations reproduce key features of the measured results and provide an insight into the mechanisms giving rise to such a high bandwidth. These analyses are described as they relate to important considerations for the VISA II experiment.

  18. Simple High-Bandwidth Sideband Locking with Heterodyne Readout

    CERN Document Server

    Reinhardt, Christoph; Sankey, Jack C

    2016-01-01

    We present a robust sideband laser locking technique that is ideally suited for applications requiring low probe power and heterodyne readout. By feeding back to a high-bandwidth voltage controlled oscillator, we lock a first-order phase-modulation sideband to a table-top high-finesse Fabry-Perot cavity, achieving a feedback bandwidth of 3.5 MHz with a single integrator, limited fundamentally by the signal delay. The directly measured transfer function of the closed feedback loop agrees with a model assuming ideal system components, and from this we suggest a modified design that should realistically achieve a bandwidth exceeding 6 MHz with a near-causally limited feedback gain of $4\\times 10^7$ at 1 kHz. The off-resonance optical carrier is used for alignment-free heterodyne readout, alleviating the need for a second laser or additional optical modulators.

  19. Managing high-bandwidth real-time data storage

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, David D. [Los Alamos National Laboratory; Brandt, Scott A [Los Alamos National Laboratory; Bent, John M [Los Alamos National Laboratory; Chen, Hsing-Bung [Los Alamos National Laboratory

    2009-09-23

    There exist certain systems which generate real-time data at high bandwidth, but do not necessarily require the long-term retention of that data in normal conditions. In some cases, the data may not actually be useful, and in others, there may be too much data to permanently retain in long-term storage whether it is useful or not. However, certain portions of the data may be identified as being vitally important from time to time, and must therefore be retained for further analysis or permanent storage without interrupting the ongoing collection of new data. We have developed a system, Mahanaxar, intended to address this problem. It provides quality of service guarantees for incoming real-time data streams and simultaneous access to already-recorded data on a best-effort basis utilizing any spare bandwidth. It has built in mechanisms for reliability and indexing, can scale upwards to meet increasing bandwidth requirements, and handles both small and large data elements equally well. We will show that a prototype version of this system provides better performance than a flat file (traditional filesystem) based version, particularly with regard to quality of service guarantees and hard real-time requirements.

  20. High-bandwidth remote flat panel display interconnect system

    Science.gov (United States)

    Peterson, Darrel G.

    1999-08-01

    High performance electronic displays (CRT, AMLCD, TFEL, plasma, etc.) require wide bandwidth electrical drive signals to produce the desired display images. When the image generation and/or image processing circuitry is located within the same line replaceable unit (LRU) as the display media, the transmission of the display drive signals to the display media presents no unusual design problems. However, many aircraft cockpits are severely constrained for available space behind the instrument panel. This often forces the system designer to specify that only the display media and its immediate support circuitry are to be mounted in the instrument panel. A wide bandwidth interconnect system is then required to transfer image data from the display generation circuitry to the display unit. Image data transfer rates of nearly 1.5 Gbits/second may be required when displaying full motion video at a 60 Hz field rate. In addition to wide bandwidth, this interconnect system must exhibit several additional key characteristics: (1) Lossless transmission of image data; (2) High reliability and high integrity; (3) Ease of installation and field maintenance; (4) High immunity to HIRF and electrical noise; (5) Low EMI emissions; (6) Long term supportability; and (7) Low acquisition and maintenance cost. Rockwell Collins has developed an avionics grade remote display interconnect system based on the American National Standards Institute Fibre Channel standard which meets these requirements. Readily available low cost commercial off the shelf (COTS) components are utilized, and qualification tests have confirmed system performance.

  1. High Bandwidth Short Stroke Rotary Fast Tool Servo

    Energy Technology Data Exchange (ETDEWEB)

    Montesanti, R C; Trumper, D L

    2003-08-22

    This paper presents the design and performance of a new rotary fast tool servo (FTS) capable of developing the 40 g's tool tip acceleration required to follow a 5 micron PV sinusoidal surface at 2 kHz with a planned accuracy of 50 nm, and having a full stroke of 50 micron PV at lower frequencies. Tests with de-rated power supplies have demonstrated a closed-loop unity-gain bandwidth of 2 kHz with 20 g's tool acceleration, and we expect to achieve 40 g's with supplies providing {+-} 16 Amp to the Lorentz force actuator. The use of a fast tool servo with a diamond turning machine for producing non-axisymmetric or textured surfaces on a workpiece is well known. Our new rotary FTS was designed to specifically accommodate fabricating prescription textured surfaces on 5 mm diameter spherical target components for High Energy Density Physics experiments on the National Ignition Facility Laser (NIF).

  2. International distance education and the transition from ISDN to high-bandwidth Internet connectivity.

    Science.gov (United States)

    Vincent, Dale S; Berg, Benjamin W; Chitpatima, Suwicha; Hudson, Donald

    2002-12-01

    The Thailand Hawaii Assessment of Interactive Healthcare Initiative (THAI-HI) is an international distance-education project between two teaching hospitals in Honolulu and Bangkok that uses videoconferencing over three ISDN lines. A 'morning report' format is used to discuss clinical cases primarily covering infectious disease and critical-care topics. An audience response system is used at both sites to add interactivity. From July 2001 to May 2002, 816 health-care providers attended 20 clinical conferences. Audiences rated the conferences as highly relevant and as having high training value. Since the ISDN connection is expensive, we plan to convert the telecommunications to a high-bandwidth Internet connection. The Honolulu site will use a 45 Mbit/s commercial connection to the Hawaii Intranetwork Consortium, which links to the Abilene Network on the US mainland. The Bangkok hospital will use a 155 Mbit/s wireless optical connection to UNINET Thailand, which has a 45 Mbit/s circuit to Abilene.

  3. Mahanaxar: quality of service guarantees in high-bandwidth, real-time streaming data storage

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, David [Los Alamos National Laboratory; Bent, John [Los Alamos National Laboratory; Chen, Hsing-Bung [Los Alamos National Laboratory; Brandt, Scott [UCSC

    2010-04-05

    Large radio telescopes, cyber-security systems monitoring real-time network traffic, and others have specialized data storage needs: guaranteed capture of an ultra-high-bandwidth data stream, retention of the data long enough to determine what is 'interesting,' retention of interesting data indefinitely, and concurrent read/write access to determine what data is interesting, without interrupting the ongoing capture of incoming data. Mahanaxar addresses this problem. Mahanaxar guarantees streaming real-time data capture at (nearly) the full rate of the raw device, allows concurrent read and write access to the device on a best-effort basis without interrupting the data capture, and retains data as long as possible given the available storage. It has built in mechanisms for reliability and indexing, can scale to meet arbitrary bandwidth requirements, and handles both small and large data elements equally well. Results from our prototype implementation shows that Mahanaxar provides both better guarantees and better performance than traditional file systems.

  4. High-gain, high-bandwidth, rail-to-rail, constant-gm CMOS operational amplifier

    Science.gov (United States)

    Huang, Hong-Yi; Wang, Bo-Ruei

    2013-01-01

    This study presents a high-gain, high-bandwidth, constant-gm , rail-to-rail operational amplifier (op-amp). The constant transconductance is improved with a source-to-bulk bias control of an input pair. A source degeneration scheme is also adapted to the output stage for receiving wide input range without degradation of the gain. Additionally, several compensation schemes are employed to enhance the stability. A test chip is fabricated in a 0.18 µm complementary metal-oxide semiconductor process. The active area of the op-amp is 181 × 173 µm2 and it consumes a power of 2.41 mW at a supply voltage of 1.8 V. The op-amp achieves a dc gain of 94.3 dB and a bandwidth of 45 MHz when the output capacitive load is connected to an effective load of 42.5 pF. A class-AB output stage combining a slew rate (SR) boost circuit provides a sinking current of 6 mA and an SR of 17 V/µs.

  5. Low data rate digital space communications

    Science.gov (United States)

    Chen, C. H.

    1973-01-01

    The low available transmitter power and the large frequency uncertainty constrain the data rate to be low. An all-digital communication receiver is proposed, and its feasibility is established. Although coherent systems should be used whenever practical, the noncoherent MFSK system is more suitable for very low data rates. The effect of Rician fading on the performance of MFSK receiver is studied. Fading characteristics of the Venus channel are examined based on the exponential model and available experimental data on the Venus atmosphere. Because of the requirement of high communication efficiency, three codes are evaluated and compared. The rapidly varying phase error at low data rate has great effects on the tracking loop behaviors which are examined by extensive computer study of the phase plane trajectories.

  6. High Bandwidth Rotary Fast Tool Servos and a Hybrid Rotary/Linear Electromagnetic Actuator

    Energy Technology Data Exchange (ETDEWEB)

    Montesanti, Richard Clement [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2005-09-01

    This thesis describes the development of two high bandwidth short-stroke rotary fast tool servos and the hybrid rotary/linear electromagnetic actuator developed for one of them. Design insights, trade-o® methodologies, and analytical tools are developed for precision mechanical systems, power and signal electronic systems, control systems, normal-stress electromagnetic actuators, and the dynamics of the combined systems.

  7. Automatic high-bandwidth calibration and reconstruction of arbitrarily sampled parallel MRI.

    Directory of Open Access Journals (Sweden)

    Jan Aelterman

    Full Text Available Today, many MRI reconstruction techniques exist for undersampled MRI data. Regularization-based techniques inspired by compressed sensing allow for the reconstruction of undersampled data that would lead to an ill-posed reconstruction problem. Parallel imaging enables the reconstruction of MRI images from undersampled multi-coil data that leads to a well-posed reconstruction problem. Autocalibrating pMRI techniques encompass pMRI techniques where no explicit knowledge of the coil sensivities is required. A first purpose of this paper is to derive a novel autocalibration approach for pMRI that allows for the estimation and use of smooth, but high-bandwidth coil profiles instead of a compactly supported kernel. These high-bandwidth models adhere more accurately to the physics of an antenna system. The second purpose of this paper is to demonstrate the feasibility of a parameter-free reconstruction algorithm that combines autocalibrating pMRI and compressed sensing. Therefore, we present several techniques for automatic parameter estimation in MRI reconstruction. Experiments show that a higher reconstruction accuracy can be had using high-bandwidth coil models and that the automatic parameter choices yield an acceptable result.

  8. Low latency, high bandwidth data communications between compute nodes in a parallel computer

    Energy Technology Data Exchange (ETDEWEB)

    Blocksome, Michael A

    2014-04-01

    Methods, systems, and products are disclosed for data transfers between nodes in a parallel computer that include: receiving, by an origin DMA on an origin node, a buffer identifier for a buffer containing data for transfer to a target node; sending, by the origin DMA to the target node, a RTS message; transferring, by the origin DMA, a data portion to the target node using a memory FIFO operation that specifies one end of the buffer from which to begin transferring the data; receiving, by the origin DMA, an acknowledgement of the RTS message from the target node; and transferring, by the origin DMA in response to receiving the acknowledgement, any remaining data portion to the target node using a direct put operation that specifies the other end of the buffer from which to begin transferring the data, including initiating the direct put operation without invoking an origin processing core.

  9. Low latency, high bandwidth data communications between compute nodes in a parallel computer

    Energy Technology Data Exchange (ETDEWEB)

    Blocksome, Michael A

    2014-04-22

    Methods, systems, and products are disclosed for data transfers between nodes in a parallel computer that include: receiving, by an origin DMA on an origin node, a buffer identifier for a buffer containing data for transfer to a target node; sending, by the origin DMA to the target node, a RTS message; transferring, by the origin DMA, a data portion to the target node using a memory FIFO operation that specifies one end of the buffer from which to begin transferring the data; receiving, by the origin DMA, an acknowledgement of the RTS message from the target node; and transferring, by the origin DMA in response to receiving the acknowledgement, any remaining data portion to the target node using a direct put operation that specifies the other end of the buffer from which to begin transferring the data, including initiating the direct put operation without invoking an origin processing core.

  10. The effect of ECB communication on interest rates : An assessment

    NARCIS (Netherlands)

    de Haan, J.

    2008-01-01

    This paper reviews the literature on the communication policy of the European Central Bank (ECB) addressing two questions. First, to what extent has ECB communication affected interest rates? Second, to what extent has ECB communication affected the predictability of the ECB's interest rate

  11. The effect of ECB communication on interest rates : An assessment

    NARCIS (Netherlands)

    de Haan, J.

    2008-01-01

    This paper reviews the literature on the communication policy of the European Central Bank (ECB) addressing two questions. First, to what extent has ECB communication affected interest rates? Second, to what extent has ECB communication affected the predictability of the ECB's interest rate decision

  12. APEnet+: high bandwidth 3D torus direct network for petaflops scale commodity clusters

    Science.gov (United States)

    Ammendola, R.; Biagioni, A.; Frezza, O.; Lo Cicero, F.; Lonardo, A.; Paolucci, P. S.; Rossetti, D.; Salamon, A.; Salina, G.; Simula, F.; Tosoratto, L.; Vicini, P.

    2011-12-01

    We describe herein the APElink+ board, a PCIe interconnect adapter featuring the latest advances in wire speed and interface technology plus hardware support for a RDMA programming model and experimental acceleration of GPU networking; this design allows us to build a low latency, high bandwidth PC cluster, the APEnet+ network, the new generation of our cost-effective, tens-of-thousands-scalable cluster network architecture. Some test results and characterization of data transmission of a complete testbench, based on a commercial development card mounting an Altera® FPGA, are provided.

  13. APEnet+: high bandwidth 3D torus direct network for petaflops scale commodity clusters

    CERN Document Server

    Ammendola, Roberto; Frezza, Ottorino; Cicero, Francesca Lo; Lonardo, Alessandro; Paolucci, Pier Stanislao; Rossetti, Davide; Salamon, Andrea; Salina, Gaetano; Simula, Francesco; Tosoratto, Laura; Vicini, Piero

    2011-01-01

    We describe herein the APElink+ board, a PCIe interconnect adapter featuring the latest advances in wire speed and interface technology plus hardware support for a RDMA programming model and experimental acceleration of GPU networking; this design allows us to build a low latency, high bandwidth PC cluster, the APEnet+ network, the new generation of our cost-effective, tens-of-thousands-scalable cluster network architecture. Some test results and characterization of data transmission of a complete testbench, based on a commercial development card mounting an Altera FPGA, are provided.

  14. Applied Techniques for High Bandwidth Data Transfers across Wide Area Networks

    Institute of Scientific and Technical Information of China (English)

    JasonLee; BillAllcock; 等

    2001-01-01

    Large distributed systems such as Computational/Data Grids require large amounts of data to be co-located with the computing facilities for processing.From our work develogpin a scalable distributed network cache.we have gained experience with techniques necessary to achieve high data throughput over high bandwidth Wide Area Networks(WAN).In this paper,we discuss several hardware and software dsign techniques,and then describe their application to an implementation of an enhanced FTP protocol called GridFTP,We describe results from the Supercomputing 2000 conference.

  15. Plasma Sensor for High Bandwidth Mass-Flow Measurements at High Mach Numbers with RF Link Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposal is aimed at the development of a miniature high bandwidth (1 MHz class) plasma sensor for flow measurements at high enthalpies. This device uses a...

  16. High-Bandwidth Tactical-Network Data Analysis in a High-Performance-Computing (HPC) Environment: Device Status Data

    Science.gov (United States)

    2015-09-01

    5.1.1 Basic Components The Hydra data processing framework provides an object - oriented hierarchy for organizing data processing within an HPC...ARL-CR-0780 ● SEP 2015 US Army Research Laboratory High-Bandwidth Tactical-Network Data Analysis in a High-Performance-Computing...ARL-CR-0780 ● SEP 2015 US Army Research Laboratory High-Bandwidth Tactical-Network Data Analysis in a High-Performance-Computing (HPC

  17. Performance of free-space laser communication systems as a function of the sampling rate in the tracking loop

    Science.gov (United States)

    Nikulin, V.; Sofka, J.; Khandekar, R.

    2005-08-01

    Laser technology plays an ever-increasing role in aerospace and communication systems and is often viewed as a technology that has the potential for providing the material base for high-bandwidth applications. Laser provides the most logical connectivity channel for mobile systems requiring high data rates, low power consumption, covert operation, and high resistance to jamming. While advancements in modern opto-electronics have resulted in small size, reliable and power efficient lasers and modulators, successful operation of any communication technology hinges upon the ability to develop an equally advanced beam steering/positioning system. In many aerospace applications, when the transmitting optical platform is placed on board of an airplane, the ability to track the target is affected by the complex high-speed maneuvers performed by the aircraft and the resident vibration of the airframe. The tracking system must assure that in spite of the relative motion of both the transmitting and receiving stations and adverse environments, such as vibration, mutual alignment of two systems will be maintained to minimize communication errors. The work presented in this paper concentrates on the development of agile beam steering systems for laser communication terminals. Acousto-optic Bragg cells are used as deflectors while feedback information is generated by a quadrant detector. The control system is synthesized using a relatively simple constant-gain controller augmented with an adaptive Kalman filter to mitigate the effects of measurement noise in the tracking system. Laboratory experiments are conducted to investigate communication performance as a function of the sampling rate in the beam position feedback.

  18. Silicon Photonics for All-Optical Processing and High-Bandwidth-Density Interconnects

    Science.gov (United States)

    Ophir, Noam

    The first chapter of the thesis provides motivation for the integration of silicon photonic modules into compute systems and surveys some of the recent developments in the field. The second chapter then proceeds to detail a technical case study of silicon photonic microring-based WDM links' scalability and power efficiency for these chip I/O applications which could be developed in the intermediate future. The analysis, initiated originally for a workshop on optical and electrical board and rack level interconnects, looks into a detailed model of the optical power budget for such a link capturing both single-channel aspects as well as WDM-operation-related considerations which are unique for a microring physical characteristics. The third chapter, while continuing on the theme silicon photonic high bandwidth density links, proceeds to detail the first experimental demonstration and characterization of an on-chip spatial division multiplexing (SDM) scheme based on microrings for the multiplexing and demultiplexing functionalities. In the context of more forward looking optical network-on-chip environments, SDM-enabled WDM photonic interconnects can potentially achieve superior bandwidth densities per waveguide compared to WDM-only photonic interconnects. The microring-based implementation allows dynamic tuning of the multiplexing and demultiplexing characteristic of the system which allows operation on WDM grid as well device tuning to combat intra-channel crosstalk. The characterization focuses on the first reported power penalty measurements for on-chip silicon photonic SDM link showing minimal penalties achievable with 3 spatial modes concurrently operating on a single waveguide with 10-Gb/s data carried by each mode. The fourth, fifth, and sixth chapters shift in topic from the application of silicon photonics to communication links to the evolving use of silicon waveguides for nonlinear all-optical processing. Chapter four primarily introduces and motivates

  19. Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

    Science.gov (United States)

    Dykstra, D.; Bockelman, B.; Blomer, J.; Herner, K.; Levshina, T.; Slyz, M.

    2015-12-01

    A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called "alien cache" to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached locally on the

  20. Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

    Energy Technology Data Exchange (ETDEWEB)

    Dykstra, D. [Fermilab; Bockelman, B. [Nebraska U.; Blomer, J. [CERN; Herner, K. [Fermilab; Levshina, T. [Fermilab; Slyz, M. [Fermilab

    2015-12-23

    A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called 'alien cache' to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached

  1. Resident Ratings of Communication Skills Using the Kalamazoo Adapted Checklist.

    Science.gov (United States)

    Porcerelli, John H; Brennan, Simone; Carty, Jennifer; Ziadni, Maisa; Markova, Tsveti

    2015-09-01

    The Kalamazoo Essential Elements Communication Checklist-Adapted (KEECC-A) is a well-regarded instrument for evaluating communication and interpersonal skills. To date, little research has been conducted that assesses the accuracy of resident self-ratings of their communication skills. To assess whether residents can accurately self-rate communication skills, using the KEECC-A, during an objective structured clinical examination (OSCE). A group of 104 residents from 8 specialties completed a multistation OSCE as part of an institutional communication skills curriculum conducted at a single institution. Standardized patients (SPs) and observers were trained in rating communication skills using the KEECC-A. Standardized patient ratings and resident self-ratings were completed immediately following each OSCE encounter, and trained observers rated archived videotapes of the encounters. Resident self-ratings and SP ratings using the KEECC-A were significantly correlated (r104  = 0.238, P = .02), as were resident self-ratings and observer ratings (r104  = 0.284, P = .004). The correlation between the SP ratings and observer (r104  = 0.378, P = .001) ratings were larger in magnitude, but not significantly different (P > .05) from resident/SP or resident/observer correlations. The results suggest that residents, with a modicum of training using the KEECC-A, can accurately rate their own communication and interpersonal skills during an OSCE. Using trained observers to rate resident communication skills provides a unique opportunity for evaluating SP and resident self-ratings. Our findings also lend further support for the reliability and validity of the KEECC-A.

  2. High Bandwidth Pickup Design for Bunch Arrival-time Monitors for Free-Electron Laser

    CERN Document Server

    Angelovski, Aleksandar; Hansli, Matthias; Penirschke, Andreas; Schnepp, Sascha M; Bousonville, Michael; Schlarb, Holger; Bock, Marie Kristin; Weiland, Thomas; Jakoby, Rolf

    2012-01-01

    In this paper, we present the design and realization of high bandwidth pickup electrodes with a cutoff frequency above 40 GHz. The proposed cone-shaped pickups are part of a bunch arrival-time monitor (BAM) designed for high (> 500 pC) and low (20 pC) bunch charge operation mode providing for a time resolution of less than 10 fs for both operation modes. The proposed design has a fast voltage response, low ringing, and a resonance-free spectrum. For assessing the influence of manufacturing tolerances on the performance of the pickups, an extensive tolerance study has been performed via numerical simulations. A non-hermetic model of the pickups was built for measurement and validation purposes. The measurement and simulation results are in good agreement and demonstrate the capability of the proposed pickup system to meet the given specifications.

  3. High bandwidth pickup design for bunch arrival-time monitors for free-electron laser

    Directory of Open Access Journals (Sweden)

    Aleksandar Angelovski

    2012-11-01

    Full Text Available In this paper, we present the design and realization of high bandwidth pickup electrodes with a cutoff frequency above 40 GHz. The proposed cone-shaped pickups are part of a bunch arrival-time monitor designed for high (>500  pC and low (20 pC bunch charge operation mode providing for a time resolution of less than 10 fs for both operation modes. The proposed design has a fast voltage response, low ringing, and a resonance-free spectrum. For assessing the influence of manufacturing tolerances on the performance of the pickups, an extensive tolerance study has been performed via numerical simulations. A nonhermetic model of the pickups was built for measurement and validation purposes. The measurement and simulation results are in good agreement and demonstrate the capability of the proposed pickup system to meet the given specifications.

  4. Pickup design for high bandwidth bunch arrival-time monitors in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Angelovski, Aleksandar; Penirschke, Andreas; Jakoby, Rolf [TU Darmstadt (Germany). Institut fuer Mikrowellentechnik und Photonik; Kuhl, Alexander; Schnepp, Sascha [TU Darmstadt (Germany). Graduate School of Computational Engineering; Bock, Marie Kristin; Bousonville, Michael; Schlarb, Holger [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Weiland, Thomas [TU Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder

    2012-07-01

    The increased demands for low bunch charge operation mode in the free-electron lasers (FELs) require an upgrade of the existing synchronization equipment. As a part of the laser-based synchronization system, the bunch arrival-time monitors (BAMs) should have a sub-10 femtosecond precision for high and low bunch charge operation. In order to fulfill the resolution demands for both modes of operation, the bandwidth of such a BAM should be increased up to a cutoff frequency of 40 GHz. In this talk, we present the design and the realization of high bandwidth cone-shaped pickup electrodes as a part of the BAM for the FEL in Hamburg (FLASH) and the European X-ray free-electron laser (European XFEL). The proposed pickup was simulated with CST STUDIO SUITE, and a non-hermetic model was built up for radio frequency (rf) measurements.

  5. High bandwidth all-optical 3×3 switch based on multimode interference structures

    Science.gov (United States)

    Le, Duy-Tien; Truong, Cao-Dung; Le, Trung-Thanh

    2017-03-01

    A high bandwidth all-optical 3×3 switch based on general interference multimode interference (GI-MMI) structure is proposed in this study. Two 3×3 multimode interference couplers are cascaded to realize an all-optical switch operating at both wavelengths of 1550 nm and 1310 nm. Two nonlinear directional couplers at two outer-arms of the structure are used as all-optical phase shifters to achieve all switching states and to control the switching states. Analytical expressions for switching operation using the transfer matrix method are presented. The beam propagation method (BPM) is used to design and optimize the whole structure. The optimal design of the all-optical phase shifters and 3×3 MMI couplers are carried out to reduce the switching power and loss.

  6. Novel high bandwidth wall shear stress sensor for ultrasonic cleaning applications

    Science.gov (United States)

    Gonzalez-Avila, S. Roberto; Prabowo, Firdaus; Ohl, Claus-Dieter

    2010-11-01

    Ultrasonic cleaning is due to the action of cavitation bubbles. The details of the cleaning mechanisms are not revealed or confirmed experimentally, yet several studies suggest that the wall shear stresses generated are very high, i.e. of the order of several thousand Pascal. Ultrasonic cleaning applications span a wide range from semiconductor manufacturing, to low pressure membrane cleaning, and the in the medical field cleaning of surgical instruments. We have developed a novel sensor to monitor and quantify cleaning activity which is (1) very sturdy, (2) has a high bandwidth of several megahertz, (3) is cheap in manufacturing costs, and (4) of very small size. We analyze the sensor signal by comparing its response time correlated to single laser induced cavitation bubbles using high-speed photography. Additionally, we will present first measurements in ultrasonic cleaning bathes using again high-speed photography. A preliminary discussion on the working mechanism of the sensor will be presented.

  7. Applied techniques for high bandwidth data transfers across wide area networks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jason; Gunter, Dan; Tierney, Brian; Allcock, Bill; Bester, Joe; Bresnahan, John; Tuecke, Steve

    2001-04-30

    Large distributed systems such as Computational/Data Grids require large amounts of data to be co-located with the computing facilities for processing. Ensuring that the data is there in time for the computation in today's Internet is a massive problem. From our work developing a scalable distributed network cache, we have gained experience with techniques necessary to achieve high data throughput over high bandwidth Wide Area Networks (WAN). In this paper, we discuss several hardware and software design techniques and issues, and then describe their application to an implementation of an enhanced FTP protocol called GridFTP. We also describe results from two applications using these techniques, which were obtained at the Supercomputing 2000 conference.

  8. Design of high-bit-rate coherent communication links

    Science.gov (United States)

    Konyshev, V. A.; Leonov, A. V.; Nanii, O. E.; Novikov, A. G.; Treshchikov, V. N.; Ubaydullaev, R. R.

    2016-12-01

    We report an analysis of the problems encountered in the design of modern high-bit-rate coherent communication links. A phenomenological communication link model is described, which is suitable for solving applied tasks of the network design with nonlinear effects taken into account. We propose an engineering approach to the design that is based on the use of fundamental nonlinearity coefficients calculated in advance for the experimental configurations of communication links. An experimental method is presented for calculating the nonlinearity coefficient of communication links. It is shown that the proposed approach allows one to successfully meet the challenges in designing communication networks.

  9. Comparing audio and video data for rating communication.

    Science.gov (United States)

    Williams, Kristine; Herman, Ruth; Bontempo, Daniel

    2013-09-01

    Video recording has become increasingly popular in nursing research, adding rich nonverbal, contextual, and behavioral information. However, benefits of video over audio data have not been well established. We compared communication ratings of audio versus video data using the Emotional Tone Rating Scale. Twenty raters watched video clips of nursing care and rated staff communication on 12 descriptors that reflect dimensions of person-centered and controlling communication. Another group rated audio-only versions of the same clips. Interrater consistency was high within each group with Interclass Correlation Coefficient (ICC) (2,1) for audio .91, and video = .94. Interrater consistency for both groups combined was also high with ICC (2,1) for audio and video = .95. Communication ratings using audio and video data were highly correlated. The value of video being superior to audio-recorded data should be evaluated in designing studies evaluating nursing care.

  10. Gbps wireless transceivers for high bandwidth interconnections in distributed cyber physical systems

    Science.gov (United States)

    Saponara, Sergio; Neri, Bruno

    2015-05-01

    In Cyber Physical Systems there is a growing use of high speed sensors like photo and video camera, radio and light detection and ranging (Radar/Lidar) sensors. Hence Cyber Physical Systems can benefit from the high communication data rate, several Gbps, that can be provided by mm-wave wireless transceivers. At such high frequency the wavelength is few mm and hence the whole transceiver including the antenna can be integrated in a single chip. To this aim this paper presents the design of 60 GHz transceiver architecture to ensure connection distances up to 10 m and data rate up to 4 Gbps. At 60 GHz there are more than 7 GHz of unlicensed bandwidth (available for free for development of new services). By using a CMOS SOI technology RF, analog and digital baseband circuitry can be integrated in the same chip minimizing noise coupling. Even the antenna is integrated on chip reducing cost and size vs. classic off-chip antenna solutions. Therefore the proposed transceiver can enable at physical layer the implementation of low cost nodes for a Cyber Physical System with data rates of several Gbps and with a communication distance suitable for home/office scenarios, or on-board vehicles such as cars, trains, ships, airplanes

  11. Serialized quantum error correction protocol for high-bandwidth quantum repeaters

    Science.gov (United States)

    Glaudell, A. N.; Waks, E.; Taylor, J. M.

    2016-09-01

    Advances in single-photon creation, transmission, and detection suggest that sending quantum information over optical fibers may have losses low enough to be correctable using a quantum error correcting code (QECC). Such error-corrected communication is equivalent to a novel quantum repeater scheme, but crucial questions regarding implementation and system requirements remain open. Here we show that long-range entangled bit generation with rates approaching 108 entangled bits per second may be possible using a completely serialized protocol, in which photons are generated, entangled, and error corrected via sequential, one-way interactions with as few matter qubits as possible. Provided loss and error rates of the required elements are below the threshold for quantum error correction, this scheme demonstrates improved performance over transmission of single photons. We find improvement in entangled bit rates at large distances using this serial protocol and various QECCs. In particular, at a total distance of 500 km with fiber loss rates of 0.3 dB km-1, logical gate failure probabilities of 10-5, photon creation and measurement error rates of 10-5, and a gate speed of 80 ps, we find the maximum single repeater chain entangled bit rates of 51 Hz at a 20 m node spacing and 190 000 Hz at a 43 m node spacing for the {[[3,1,2

  12. Controllable high bandwidth storage of optical information in a Bose-Einstein Condensate

    Science.gov (United States)

    Jayaseelan, Maitreyi; Schultz, Justin T.; Murphree, Joseph D.; Hansen, Azure; Bigelow, Nicholas P.

    2016-05-01

    The storage and retrieval of optical information has been of interest for a variety of applications including quantum information processing, quantum networks and quantum memories. Several schemes have been investigated and realized with weak, narrowband pulses, including techniques using EIT in solid state systems and both hot and cold atomic vapors. In contrast, we investigate the storage and manipulation of strong, high bandwidth pulses in a Bose-Einstein Condensate (BEC) of ultracold 87 Rb atoms. As a storage medium for optical pulses, BECs offer long storage times and preserve the coherence properties of the input information, suppressing unwanted thermal decoherence effects. We present numerical simulations of nanosecond pulses addressing a three-level lambda system on the D2 line of 87 Rb. The signal pulse is stored as a localized spin excitation in the condensate and can be moved or retrieved by reapplication of successive control pulses. The relative Rabi frequencies and areas of the pulses and the local atomic density in the condensate determine the storage location and readout of the signal pulse. Extending this scheme to use beams with a variety of spatial modes such as Hermite- and Laguerre-Gaussian modes offers an expanded alphabet for information storage.

  13. Multiplexed CV quantum teleportation for high rates in quantum communication

    CERN Document Server

    Christ, Andreas; Silberhorn, Christine

    2012-01-01

    A major challenge of today's quantum communication systems lies in the transmission of quantum information with high rates over long distances in the presence of unavoidable losses. Thereby the achievable quantum communication rate is fundamentally limited by the amount of energy that can be transmitted per use of the channel. It is hence vital to develop quantum communication protocols which encode quantum information as energy efficiently as possible. To this aim we investigate continuous-variable quantum teleportation as a method of distributing quantum information. We explore the possibility to encode information on multiple optical modes and derive upper and lower bounds on the achievable quantum channel capacities. This analysis enables us to benchmark single-mode vs. multi-mode entanglement resources. Our research reveals that multiplexing does not only feature an enhanced energy efficiency, significantly increasing the achievable quantum communication rates in comparison to single-mode coding, but als...

  14. Assessing students' communication skills: validation of a global rating.

    Science.gov (United States)

    Scheffer, Simone; Muehlinghaus, Isabel; Froehmel, Annette; Ortwein, Heiderose

    2008-12-01

    Communication skills training is an accepted part of undergraduate medical programs nowadays. In addition to learning experiences its importance should be emphasised by performance-based assessment. As detailed checklists have been shown to be not well suited for the assessment of communication skills for different reasons, this study aimed to validate a global rating scale. A Canadian instrument was translated to German and adapted to assess students' communication skills during an end-of-semester-OSCE. Subjects were second and third year medical students at the reformed track of the Charité-Universitaetsmedizin Berlin. Different groups of raters were trained to assess students' communication skills using the global rating scale. Validity testing included concurrent validity and construct validity: Judgements of different groups of raters were compared to expert ratings as a defined gold standard. Furthermore, the amount of agreement between scores obtained with this global rating scale and a different instrument for assessing communication skills was determined. Results show that communication skills can be validly assessed by trained non-expert raters as well as standardised patients using this instrument.

  15. Quantum data locking for high-rate private communication

    Science.gov (United States)

    Lupo, Cosmo; Lloyd, Seth

    2015-03-01

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security holds against an eavesdropper who is forced to measure her share of the quantum system within a finite time after she gets it.

  16. An Architecture for High Data Rate Very Low Frequency Communication

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2013-01-01

    Full Text Available Very low frequency (VLF communication is used for long range shore-to-ship broadcasting applications. This paper proposes an architecture for high data rate VLF communication using Gaussian minimum shift keying (GMSK modulation and low delay parity check (LDPC channel coding. Non-data aided techniques are designed and used for carrier phase synchronization, symbol timing recovery, and LDPC code frame synchronization. These require the estimation of the operative Eb/N0 for which a kurtosis based algorithm is used. Also, a method for modeling the probability density function of the received signal under the bit condition is presented in this regard. The modeling of atmospheric radio noise (ARN that corrupts VLF signals is described and an algorithm for signal enhancement in the presence of ARN in given. The BER performance of the communication system is evaluated for bit rates of 400 bps, 600 bps, and 800 bps for communication bandwidth of ~200 Hz.

  17. Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

    Science.gov (United States)

    Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

    2012-01-01

    At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

  18. Design, analysis and testing of a parallel-kinematic high-bandwidth XY nanopositioning stage

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chun-Xia; Gu, Guo-Ying; Yang, Mei-Ju; Zhu, Li-Min, E-mail: zhulm@sjtu.edu.cn [State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-12-15

    This paper presents the design, analysis, and testing of a parallel-kinematic high-bandwidth XY nanopositioning stage driven by piezoelectric stack actuators. The stage is designed with two kinematic chains. In each kinematic chain, the end-effector of the stage is connected to the base by two symmetrically distributed flexure modules, respectively. Each flexure module comprises a fixed-fixed beam and a parallelogram flexure serving as two orthogonal prismatic joints. With the purpose to achieve high resonance frequencies of the stage, a novel center-thickened beam which has large stiffness is proposed to act as the fixed-fixed beam. The center-thickened beam also contributes to reducing cross-coupling and restricting parasitic motion. To decouple the motion in two axes totally, a symmetric configuration is adopted for the parallelogram flexures. Based on the analytical models established in static and dynamic analysis, the dimensions of the stage are optimized in order to maximize the first resonance frequency. Then finite element analysis is utilized to validate the design and a prototype of the stage is fabricated for performance tests. According to the results of static and dynamic tests, the resonance frequencies of the developed stage are over 13.6 kHz and the workspace is 11.2 μm × 11.6 μm with the cross-coupling between two axes less than 0.52%. It is clearly demonstrated that the developed stage has high resonance frequencies, a relatively large travel range, and nearly decoupled performance between two axes. For high-speed tracking performance tests, an inversion-based feedforward controller is implemented for the stage to compensate for the positioning errors caused by mechanical vibration. The experimental results show that good tracking performance at high speed is achieved, which validates the effectiveness of the developed stage.

  19. High-Bandwidth Photon-Counting Detectors with Enhanced Near-Infrared Response Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Laser optical communications offer the potential to dramatically increase the link bandwidth and decrease the emitter power in long-range space communications....

  20. Level-1 Data Driver Card - A high bandwidth radiation tolerant aggregator board for detectors

    CERN Document Server

    Gkountoumis, Panagiotis; The ATLAS collaboration

    2017-01-01

    The Level-1 Data Driver Card (L1DDC) was designed for the needs of the future upgrades of the innermost stations of the ATLAS end-cap muon spectrometer. The L1DDC is a high speed aggregator board capable of communicating with multiple front-end electronic boards. It collects the Level-1 data along with monitoring data and transmits them to a network interface through bidirectional and/or unidirectional fiber links at 4.8 Gbps each. In addition, the L1DDC board distributes trigger, time and configuration data coming from the network interface to the front-end boards. The L1DDC is fully compatible with the Phase II upgrade where the trigger rate is expected to reach the 1 MHz. Three different types of L1DDC boards will be fabricated handling up to 10.080 Gbps of user data. It consist of custom made radiation tolerant ASICs: the GigaBit Transceiver (GBTx), the FEAST DC-DC converter, the Slow Control Adapter (SCA), and the Versatile Tranceivers (VTRX) and transmitters (VTTX). The overall scheme of the data acquis...

  1. OFDM-based Low-voltage Powerline High Rate Communication

    Institute of Scientific and Technical Information of China (English)

    ZHANG You-bing(张有兵); CHENG Shi-jie(程时杰); Joseph Nguimbis; XIONG Lan(熊兰)

    2004-01-01

    Based on the experimental results, a simplified model for low-voltage powerline used as a high frequency communication channel is presented. With this model, the Orthogonal Frequency Division Multiplexing (OFDM) based high rate digital communication over low-voltage powerline is analyzed and simulated. The capability of thc signal transmission system in overcoming multi-path interference and selection of the system parameters are discussed. And time-domain simulation is carried out to investigate the transmission capability of the OFDM cammunication system for different mapping schemes and transmission power levels. Simulation results show that it is possible to realize high rate digital communication over iow-voltage powerliue using OFDM when the transmitted power is large enough.

  2. Ka-band MMIC microstrip array for high rate communications

    Science.gov (United States)

    Lee, R. Q.; Raquet, C. A.; Tolleson, J. B.; Sanzgiri, S. M.

    1991-01-01

    In a recent technology assessment of alternative communication systems for the space exploration initiative (SEI), Ka-band (18 to 40 GHz) communication technology was identified to meet the mission requirements of telecommunication, navigation, and information management. Compared to the lower frequency bands, Ka-band antennas offer higher gain and broader bandwidths; thus, they are more suitable for high data rate communications. Over the years, NASA has played an important role in monolithic microwave integrated circuit (MMIC) phased array technology development, and currently, has an ongoing contract with Texas Instrument (TI) to develop a modular Ka-band MMIC microstrip subarray (NAS3-25718). The TI contract emphasizes MMIC integration technology development and stipulates using existing MMIC devices to minimize the array development cost. The objective of this paper is to present array component technologies and integration techniques used to construct the subarray modules.

  3. Simple Laser Communications Terminal for Downlink from Earth Orbit at Rates Exceeding 10 Gb/s

    Science.gov (United States)

    Kovalik, Joseph M.; Hemmati, Hamid; Biswas, Abhijit; Roberts, William T.

    2013-01-01

    A compact, low-cost laser communications transceiver was prototyped for downlinking data at 10 Gb/s from Earth-orbiting spacecraft. The design can be implemented using flight-grade parts. With emphasis on simplicity, compactness, and light weight of the flight transceiver, the reduced-complexity design and development approach involves: 1. A high-bandwidth coarse wavelength division multiplexed (CWDM) (4 2.5 or 10-Gb/s data-rate) downlink transmitter. To simplify the system, emphasis is on the downlink. Optical uplink data rate is modest (due to existing and adequate RF uplink capability). 2. Highly simplified and compact 5-cm diameter clear aperture optics assembly is configured to single transmit and receive aperture laser signals. About 2 W of 4-channel multiplexed (1,540 to 1,555 nm) optically amplified laser power is coupled to the optical assembly through a fiber optic cable. It contains a highly compact, precision-pointing capability two-axis gimbal assembly to coarse point the optics assembly. A fast steering mirror, built into the optical path of the optical assembly, is used to remove residual pointing disturbances from the gimbal. Acquisition, pointing, and tracking are assisted by a beacon laser transmitted from the ground and received by the optical assembly, which will allow transmission of a laser beam. 3. Shifting the link burden to the ground by relying on direct detection optical receivers retrofitted to 1-m-diameter ground telescopes. 4. Favored mass and volume reduction over power-consumption reduction. The two major variables that are available include laser transmit power at either end of the link, and telescope aperture diameter at each end of the link. Increased laser power is traded for smaller-aperture diameters. 5. Use of commercially available spacequalified or qualifiable components with traceability to flight qualification (i.e., a flight-qualified version is commercially available). An example is use of Telecordia-qualified fiber

  4. An Architecture for High Data Rate Very Low Frequency Communication

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2013-01-01

    Full Text Available Very low frequency (VLF communication is used for long range shore-to-ship broadcasting applications. This paper proposes an architecture for high data rate VLF communication using Gaussian minimum shift keying (GMSK modulation and low delay parity check (LDPC channel coding. Non-data aided techniques are designed and used for carrier phase synchronization, symbol timing recovery, and LDPC code frame synchronization. These require the estimation of the operative Eb/N0 for which a kurtosis based algorithm is used. Also, a method for modeling the probability density function of the received signal under the bit condition is presented in this regard. The modeling of atmospheric radio noise (ARN that corrupts VLF signals is described and an algorithm for signal enhancement in the presence of ARN in given. The BER performance of the communication system is evaluated for bit rates of 400 bps, 600 bps, and 800 bps for communication bandwidth of ~200 Hz.Defence Science Journal, 2013, 63(1, pp.25-33, DOI:http://dx.doi.org/10.14429/dsj.63.3760

  5. Information theory and rate distortion theory for communications and compression

    CERN Document Server

    Gibson, Jerry

    2013-01-01

    This book is very specifically targeted to problems in communications and compression by providing the fundamental principles and results in information theory and rate distortion theory for these applications and presenting methods that have proved and will prove useful in analyzing and designing real systems. The chapters contain treatments of entropy, mutual information, lossless source coding, channel capacity, and rate distortion theory; however, it is the selection, ordering, and presentation of the topics within these broad categories that is unique to this concise book. While the cover

  6. Fiber optic communications fundamentals and applications

    CERN Document Server

    Kumar, Shiva

    2014-01-01

    Fiber-optic communication systems have advanced dramatically over the last four decades, since the era of copper cables, resulting in low-cost and high-bandwidth transmission. Fiber optics is now the backbone of the internet and long-distance telecommunication. Without it we would not enjoy the benefits of high-speed internet, or low-rate international telephone calls. This book introduces the basic concepts of fiber-optic communication in a pedagogical way. The important mathematical results are derived by first principles rather than citing research articles. In addition, physical interpre

  7. High-bandwidth Modulation of H2/Syngas Fuel to Control Combustion Dynamics in Micro-Mixing Lean Premix Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Melzak; Tim Lieuwen; Adel Mansour

    2012-01-31

    The goal of this program was to develop and demonstrate fuel injection technologies that will facilitate the development of cost-effective turbine engines for Integrated Gasification Combined Cycle (IGCC) power plants, while improving efficiency and reducing emissions. The program involved developing a next-generation multi-point injector with enhanced stability performance for lean premix turbine systems that burn hydrogen (H2) or synthesis gas (syngas) fuels. A previously developed injector that demonstrated superior emissions performance was improved to enhance static flame stability through zone staging and pilot sheltering. In addition, piezo valve technology was implemented to investigate the potential for enhanced dynamic stability through high-bandwidth modulation of the fuel supply. Prototype injector and valve hardware were tested in an atmospheric combustion facility. The program was successful in meeting its objectives. Specifically, the following was accomplished: Demonstrated improvement of lean operability of the Parker multi-point injector through staging of fuel flow and primary zone sheltering; Developed a piezo valve capable of proportional and high-bandwidth modulation of gaseous fuel flow at frequencies as high as 500 Hz; The valve was shown to be capable of effecting changes to flame dynamics, heat release, and acoustic signature of an atmospheric combustor. The latter achievement indicates the viability of the Parker piezo valve technology for use in future adaptively controlled systems for the mitigation of combustion instabilities, particularly for attenuating combustion dynamics under ultra-lean conditions.

  8. Improved Rate-Equivocation Regions for Secure Cooperative Communication

    CERN Document Server

    Marina, Ninoslav; Poor, H Vincent

    2011-01-01

    A simple four node network in which cooperation improves the information-theoretic secrecy is studied. The channel consists of two senders, a receiver, and an eavesdropper. One or both senders transmit confidential messages to the receiver, while the eavesdropper tries to decode the transmitted message. The main result is the derivation of a newly achievable rate-equivocation region that is shown to be larger than a rate-equivocation region derived by Lai and El Gamal for the relay-eavesdropper channel. When the rate of the helping interferer is zero, the new rate-equivocation region reduces to the capacity-equivocation region over the wire-tap channel, hence, the new achievability scheme can be seen as a generalization of a coding scheme proposed by Csiszar and Korner. This result can naturally be combined with a rate-equivocation region given by Tang et al. (for the interference assisted secret communication), yielding an even larger achievable rate-equivocation region.

  9. High-rate wireless data communications: An underwater acoustic communications framework at the physical layer

    Directory of Open Access Journals (Sweden)

    Bessios Anthony G.

    1996-01-01

    Full Text Available A variety of signal processing functions are performed by Underwater Acoustic Systems. These include: 1 detection to determine presence or absence of information signals in the presence of noise, or an attempt to describe which of a predetermined finite set of possible messages { m i , i , ... , M } the signal represents; 2 estimation of some parameter θ ˆ associated with the received signal (i.e. range, depth, bearing angle, etc.; 3 classification and source identification; 4 dynamics tracking; 5 navigation (collision avoidance and terminal guidance; 6 countermeasures; and 7 communications. The focus of this paper is acoustic communications. There is a global current need to develop reliable wireless digital communications for the underwater environment, with sufficient performance and efficiency to substitute for costly wired systems. One possible goal is a wireless system implementation that insures underwater terminal mobility. There is also a vital need to improve the performance of the existing systems in terms of data-rate, noise immunity, operational range, and power consumption, since, in practice, portable high-speed, long range, compact, low-power systems are desired. We concede the difficulties associated with acoustic systems and concentrate on the development of robust data transmission methods anticipating the eventual need for real time or near real time video transmission. An overview of the various detection techniques and the general statistical digital communication problem is given based on a statistical decision theory framework. The theoretical formulation of the underwater acoustic data communications problem includes modeling of the stochastic channel to incorporate a variety of impairments and environmental uncertainties, and proposal of new compensation strategies for an efficient and robust receiver design.

  10. High-Bandwidth Atomic Force Microscopy Reveals A Mechanical spike Accompanying the Action Potential in mammalian Nerve Terminals

    Science.gov (United States)

    Salzberg, Brian M.

    2008-03-01

    Information transfer from neuron to neuron within nervous systems occurs when the action potential arrives at a nerve terminal and initiates the release of a chemical messenger (neurotransmitter). In the mammalian neurohypophysis (posterior pituitary), large and rapid changes in light scattering accompany secretion of transmitter-like neuropeptides. In the mouse, these intrinsic optical signals are intimately related to the arrival of the action potential (E-wave) and the release of arginine vasopressin and oxytocin (S-wave). We have used a high bandwidth (20 kHz) atomic force microscope (AFM) to demonstrate that these light scattering signals are associated with changes in nerve terminal volume, detected as nanometer-scale movements of a cantilever positioned on top of the neurohypophysis. The most rapid mechanical response, the ``spike'', has duration comparable to that of the action potential (˜2 ms) and probably reflects an increase in terminal volume due to H2O movement associated with Na^+-influx. Elementary calculations suggest that two H2O molecules accompanying each Na^+-ion could account for the ˜0.5-1.0 å increase in the diameter of each terminal during the action potential. Distinguishable from the mechanical ``spike'', a slower mechanical event, the ``dip'', represents a decrease in nerve terminal volume, depends upon Ca^2+-entry, as well as on intra-terminal Ca^2+-transients, and appears to monitor events associated with secretion. A simple hypothesis is that this ``dip'' reflects the extrusion of the dense core granule that comprises the secretory products. These dynamic high bandwidth AFM recordings are the first to monitor mechanical events in nervous systems and may provide novel insights into the mechanism(s) by which excitation is coupled to secretion at nerve terminals.

  11. Radiation-tolerant, low-mass, high bandwidth, flexible printed circuit cables for particle physics experiments

    Science.gov (United States)

    McFadden, N. C.; Hoeferkamp, M. R.; Seidel, S.

    2016-09-01

    The design of meter long flexible printed circuit cables required for low-mass ultra-high speed signal transmission in the high radiation environment of the High Luminosity Large Hadron Collider is described. The design geometry is a differential embedded microstrip with 100 Ω nominal impedance. Minimal mass and maximal radiation hardness are pre-eminent considerations. Several dielectric materials are compared. To reduce mass, a cross hatched ground plane is applied. The long flexible printed circuit cables are characterized in bit error rate tests, attenuation versus frequency, mechanical response to temperature induced stress, and dimensional implications on radiation length. These tests are performed before and after irradiation with 1 MeV neutrons to 2×1016/cm2 and 800 MeV protons to 2×1016 1-MeV neutron equivalent/cm2. A 1.0 m Kapton cable with cross hatched ground plane, effective bandwidth of 4.976 gigabits per second, 0.0160% of a radiation length, and no detectable radiation-induced mechanical or electrical degradation is obtained.

  12. Radiation-tolerant, low-mass, high bandwidth, flexible printed circuit cables for particle physics experiments

    Energy Technology Data Exchange (ETDEWEB)

    McFadden, N.C.; Hoeferkamp, M.R.; Seidel, S.

    2016-09-11

    The design of meter long flexible printed circuit cables required for low-mass ultra-high speed signal transmission in the high radiation environment of the High Luminosity Large Hadron Collider is described. The design geometry is a differential embedded microstrip with 100 Ω nominal impedance. Minimal mass and maximal radiation hardness are pre-eminent considerations. Several dielectric materials are compared. To reduce mass, a cross hatched ground plane is applied. The long flexible printed circuit cables are characterized in bit error rate tests, attenuation versus frequency, mechanical response to temperature induced stress, and dimensional implications on radiation length. These tests are performed before and after irradiation with 1 MeV neutrons to 2×10{sup 16}/cm{sup 2} and 800 MeV protons to 2×10{sup 16} 1-MeV neutron equivalent/cm{sup 2}. A 1.0 m Kapton cable with cross hatched ground plane, effective bandwidth of 4.976 gigabits per second, 0.0160% of a radiation length, and no detectable radiation-induced mechanical or electrical degradation is obtained.

  13. ICE-based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

    CERN Document Server

    Bandura, Kevin; Dobbs, Matt; Gilbert, Adam; Ittah, David; Parra, Juan Mena; Smecher, Graeme

    2016-01-01

    New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2048 digitizer inputs across 400~MHz of bandwidth. Measured in $N^2~\\times $ bandwidth, it is the largest radio correlator that has been built. Its digital back-end must exchange and reorganize the 6.6~terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256-node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. `corner-turn'). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct,...

  14. High Bandwidth, Multi-Purpose Passive Radar Receiver Design For Aerospace and Geoscience Targets

    Science.gov (United States)

    Vertatschitsch, Laura

    Passive radar permits inexpensive and stealthy detection and tracking of aerospace and geoscience targets. Transmitters of opportunity such as commercial FM broadcast, DTV broadcast, and cell phone towers are already illuminating many populated areas with continuous power. Passive radar receivers can be located at a distance from the transmitter, and can sense this direct transmission as well as any reflections from ground clutter, aircraft, ionospheric turbulence and meteor trails. The 100% duty cycle allows for long coherent integration, increasing the sensitivity of these instruments greatly. Traditional radar receivers employ analog front end downconverters to translate the radio frequency spectrum to an intermediate frequency (IF) for sampling and signal processing. Such downconverters limit the spectrum available for study, and can introduce nonlinearities which limit the detectability of weak signals in the presence of strong signals. With suitably fast digitizers one can bypass the downconversion stage completely. Very fast digitizers may have relatively few bits, but precision is recovered in subsequent signal processing. We present a new passive radar receiver designed to utilize a broad spectrum of commercial transmitters without the use of a front end analog downconverter. The receiver centers around a Reconfigurable Open Architecture Computing Hardware (ROACH) board developed by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) group. Fast sampling rates (8-bit samples as fast as 3 GSps) combined with 640 multiply/addition operations on the Virtex-5 FPGA centered on the ROACH allows for coherent processing of broad spectrum and dynamic decision-making on one device all while sharing a single front end, putting this device on the cutting edge of wideband receiver technology. The radar is also designed to support mobile operation. It fits within a 19'' rack, it is equipped with solid state hard drives, and can run off an

  15. Packet Capture Solutions: PcapDB Benchmark for High-Bandwidth Capture, Storage, and Searching

    Energy Technology Data Exchange (ETDEWEB)

    Steinfadt, Shannon Irene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ferrell, Paul Steven [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-21

    PcapDB stands alone when looking at the overall field of competitors, from the cost-effective COTS hardware, to the efficient utilization of disk space that enables a longer packet history. A scalable, 100GbE-enabled system that indexes every packet and indexes flow data without complicated load-balancing requirements. The Transport Layer search and indexing approach led to patent-pending flow indexing technology, providing a specialized database system specifically optimized around providing fast flow searches. While there are a plethora of options in network packet capture, there are very few that are able to effectively manage capture rates of more than 10 Gb/s, distributed capture and querying, and a responsive user interface. By far, the primary competitor in the market place is Endace and DeepSee; in addition to meeting the technical requirements we set out in this document, they provide technical support and a fully 'appliance like' system. In terms of cost, however, our experience has been that the yearly maintenance charges alone outstrip the entire hardware cost of solutions like PcapDB. Investment in cyber security research and development is a large part of what has enabled us to build the base of knowlegable workers needed to defend government resources in the rapidly evolving cyber security landscape. We believe projects like Bro, WireCap, and Farm do more than just fill temporary gaps in our capabilities. They give allow us to build the firm foundation needed to tackle the next generation of cyber challenges. PcapDB was built with loftier ambitions than simply solving the packet capture of a single lab site, but instead to provide a robust, scaleable packet capture solution to the DOE complex and beyond.

  16. ICE-Based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

    Science.gov (United States)

    Bandura, K.; Cliche, J. F.; Dobbs, M. A.; Gilbert, A. J.; Ittah, D.; Mena Parra, J.; Smecher, G.

    New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2,048 digitizer inputs across 400MHz of bandwidth. Measured in N2× bandwidth, it is the largest radio correlator that is currently commissioning. Its digital back-end must exchange and reorganize the 6.6terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256 graphics processing unit (GPU) node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. ‘corner-turn’). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct, passive copper, full-mesh, high speed serial connections between sixteen circuit boards in a crate, to exchange data between crates, and to offload the data to a cluster of 256 GPU nodes using standard 10Gbit/s Ethernet links. The GPU nodes complete the corner-turn by combining data from all crates and then computing visibilities. Eye diagrams and frame error counters confirm error-free operation of the corner-turn network in both the currently operating CHIME Pathfinder telescope (a prototype for the full CHIME telescope) and a representative fraction of the full CHIME hardware providing an end-to-end system validation. An analysis of an equivalent corner-turn system built with Ethernet switches instead of custom passive data links is provided.

  17. Modelling high data rate communication network access protocol

    Science.gov (United States)

    Khanna, S.; Foudriat, E. C.; Paterra, Frank; Maly, Kurt J.; Overstreet, C. Michael

    1990-01-01

    Modeling of high data rate communication systems is different from the low data rate systems. Three simulations were built during the development phase of Carrier Sensed Multiple Access/Ring Network (CSMA/RN) modeling. The first was a model using SIMCRIPT based upon the determination and processing of each event at each node. The second simulation was developed in C based upon isolating the distinct object that can be identified as the ring, the message, the node, and the set of critical events. The third model further identified the basic network functionality by creating a single object, the node which includes the set of critical events which occur at the node. The ring structure is implicit in the node structure. This model was also built in C. Each model is discussed and their features compared. It should be stated that the language used was mainly selected by the model developer because of his past familiarity. Further the models were not built with the intent to compare either structure or language but because the complexity of the problem and initial results contained obvious errors, so alternative models were built to isolate, determine, and correct programming and modeling errors. The CSMA/RN protocol is discussed in sufficient detail to understand modeling complexities. Each model is described along with its features and problems. The models are compared and concluding observations and remarks are presented.

  18. Micro-Laser Communications Modules Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High bandwidth communication links are needed between satellites and ground stations, inter-satellite, and to airborne assets. As data loads increase and satellites...

  19. Preliminary Measurement of Communication Rates on the Cray T3D Interprocessor Network

    Science.gov (United States)

    Springer, Paul; Peterson, John; Numrich, Robert

    1993-01-01

    None given.(from task description): Objectives: test the communication network, determine how communication rates scale with message size, test the effect of contention, show the effect of contention.

  20. Training-Based Schemes are Suboptimal for High Rate Asynchronous Communication

    CERN Document Server

    Chandar, Venkat; Wornell, Gregory W

    2009-01-01

    We consider asynchronous point-to-point communication. Building on a recently developed model, we show that training based schemes, i.e., communication strategies that separate synchronization from information transmission, perform suboptimally at high rate.

  1. Assessing Students' Communication Skills: Validation of a Global Rating

    Science.gov (United States)

    Scheffer, Simone; Muehlinghaus, Isabel; Froehmel, Annette; Ortwein, Heiderose

    2008-01-01

    Communication skills training is an accepted part of undergraduate medical programs nowadays. In addition to learning experiences its importance should be emphasised by performance-based assessment. As detailed checklists have been shown to be not well suited for the assessment of communication skills for different reasons, this study aimed to…

  2. Electro-optic prism-pair setup for efficient high bandwidth isochronous CEP phase shift or group delay generation

    Science.gov (United States)

    Gobert, Olivier; Mennerat, Gabriel; Cornaggia, Christian; Lupinski, Dominique; Perdrix, Michel; Guillaumet, Delphine; Lepetit, Fabien; Oksenhendler, Thomas; Comte, Michel

    2016-05-01

    We report the experimental demonstration of an electro-optic prism pair pure carrier-envelope phase (CEP) shifter at low voltage (shift of 1 rad for a voltage of 90 V, applied to a crystal of 5 mm aperture). Validating our mathematical model, the experiments prove that this set-up which uses two rubidium titanyl phosphate (RTP) crystals, can be used either as an efficient high bandwidth CEP shifter without modifying the group delay of an ultrashort pulse (isochronous CEP shifter) or alternatively as a group delay generator with quasi-constant CEP (Pure Group Delay generator). These two configurations which correspond to specific geometries are characterized by spectral interferometry with a 800 nm mode-locked Ti:sapphire laser. The results are in very good agreement with the model. In the pure group delay mode, a group delay of 2.3 fs is obtained at 1000 V/cm without significant CEP shift. In the isochronous mode, a shift of 5.5 rad at 1000 V/cm is generated without significant delay. The applied voltage is also lowered by a factor of nearly three in this configuration, compared to the case of an RTP rectangular slab of the same total length.

  3. Parent and Teacher Ratings of Communication among Children with Severe Disabilities and Visual Impairment/Blindness

    Science.gov (United States)

    Cascella, Paul W.; Trief, Ellen; Bruce, Susan M.

    2012-01-01

    Three trends emerged from independent parent and teacher ratings of receptive communication and expressive forms and functions among students with severe disabilities and visual impairment/blindness. Parents had higher ratings than teachers, receptive communication was rated the highest, and no skills occurred often. Implications are discussed for…

  4. Evaluating the Effectiveness of Rating Instruments for a Communication Skills Assessment of Medical Residents

    Science.gov (United States)

    Iramaneerat, Cherdsak; Myford, Carol M.; Yudkowsky, Rachel; Lowenstein, Tali

    2009-01-01

    The investigators used evidence based on response processes to evaluate and improve the validity of scores on the Patient-Centered Communication and Interpersonal Skills (CIS) Scale for the assessment of residents' communication competence. The investigators retrospectively analyzed the communication skills ratings of 68 residents at the…

  5. Validity Evidence for the Interpretation and Use of Essential Elements of Communication Global Rating Scale Scores

    Science.gov (United States)

    Schneider, Nancy Rhoda

    2015-01-01

    Purpose. Clinical communication influences health outcomes, so medical schools are charged to prepare future physicians with the skills they need to interact effectively with patients. Communication leaders at The University of New Mexico School of Medicine (UNMSOM) developed The Essential Elements of Communication-Global Rating Scale (EEC-GRS) to…

  6. Validity Evidence for the Interpretation and Use of Essential Elements of Communication Global Rating Scale Scores

    Science.gov (United States)

    Schneider, Nancy Rhoda

    2015-01-01

    Purpose. Clinical communication influences health outcomes, so medical schools are charged to prepare future physicians with the skills they need to interact effectively with patients. Communication leaders at The University of New Mexico School of Medicine (UNMSOM) developed The Essential Elements of Communication-Global Rating Scale (EEC-GRS) to…

  7. Specialties differ in which aspects of doctor communication predict overall physician ratings.

    Science.gov (United States)

    Quigley, Denise D; Elliott, Marc N; Farley, Donna O; Burkhart, Q; Skootsky, Samuel A; Hays, Ron D

    2014-03-01

    Effective doctor communication is critical to positive doctor-patient relationships and predicts better health outcomes. Doctor communication is the strongest predictor of patient ratings of doctors, but the most important aspects of communication may vary by specialty. To determine the importance of five aspects of doctor communication to overall physician ratings by specialty. For each of 28 specialties, we calculated partial correlations of five communication items with a 0-10 overall physician rating, controlling for patient demographics. Consumer Assessment of Healthcare Providers and Systems Clinician and Group (CG-CAHPS®) 12-month Survey data collected 2005-2009 from 58,251 adults at a 534-physician medical group. CG-CAHPS includes a 0 ("Worst physician possible") to 10 ("Best physician possible") overall physician rating. Five doctor communication items assess how often the physician: explains things; listens carefully; gives easy-to-understand instructions; shows respect; and spends enough time. Physician showing respect was the most important aspect of communication for 23/28 specialties, with a mean partial correlation (0.27, ranging from 0.07 to 0.44 across specialties) that accounted for more than four times as much variance in the overall physician rating as any other communication item. Three of five communication items varied significantly across specialties in their associations with the overall rating (p < 0.05). All patients valued respectful treatment; the importance of other aspects of communication varied significantly by specialty. Quality improvement efforts by all specialties should emphasize physicians showing respect to patients, and each specialty should also target other aspects of communication that matter most to their patients. The results have implications for improving provider quality improvement and incentive programs and the reporting of CAHPS data to patients. Specialists make important contributions to coordinated patient

  8. Effects of Therapist's Nonverbal Communication on Rated Skill and Effectiveness.

    Science.gov (United States)

    Sherer, Mark; Rogers, Ronald W.

    1980-01-01

    Nonverbal cues of immediacy significantly improved ratings of the therapist's interpersonal skills and effectiveness. A therapist's nonverbal behavior is a basis for interpretations of empathy, warmth, genuineness, and effectiveness. (Author)

  9. Quantum Communication with a High-Rate Entangled Photon Source

    Science.gov (United States)

    Wilson, Nathaniel C.; Chaffee, Dalton W.; Lekki, John D.; Wilson, Jeffrey D.

    2016-01-01

    A high generation rate photon-pair source using a dual element periodically-poled potassium titanyl phosphate (PP KTP) waveguide is described. The photon-pair source features a high pair generation rate, a compact power-efficient package, and continuous wave (CW) or pulsed operation. Characterization and test results are presented. Details and preliminary results of a laboratory free-space QKD experiment with the B92 protocol are also presented.

  10. Concordance between Self and Standardized Patient Ratings of Medical Students' Communication Skills.

    Science.gov (United States)

    Je, Min Ji; Lee, Su Hyun; Lee, Chang Hyung; Kim, Sung Soo

    2013-03-01

    The purpose of this study was to examine the concordance between self and standardized patient (SP) ratings of medical students' communication skills. Forty-three students interviewed SPs. The students were asked to complete a communication skills questionnaire that comprised 2 measures (empathy and interpersonal communication) before the interview. After each student's interview with the SP, the latter completed the same questionnaire as the students. Based on Lin's concordance coefficient, there was strong disconcordance between students' self-ratings and the SPs' ratings. With regard to empathic communication, more than 50% of students who considered themselves higher than middle level were regarded by SP as low level. On interpersonal communication, 39% of students who assessed themselves as higher than middle level were scored low level by SPs. There was strong disconcordance between students' self-ratings and the SPs' ratings-students tended to overevaluate themselves regarding their communication skills. These differences might result in patient dissatisfaction and noncompliance. Further, it could become a serious hindrance to the development of a good doctor-patient relationship. Medical educators should make sincere efforts to reduce this gap by teaching medical students the importance of the patients' perception of his doctors' communication skills.

  11. Programmable High-Rate Multi-Mission Receiver for Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current and upcoming NASA space links require both highly reliable low-rate communications links supporting critical TT&C, ranging and voice services and highly...

  12. Robust Frequency Hopping for High Data Rate Tactical Communications

    Science.gov (United States)

    2006-12-01

    Filter Insert Pilot Channel, h(τ;t) AWGN Jamming Models. J(t) Demod Q Parallel subbands to Serial bit stream Demod EQU EQU Channel...results remains fixed at 5MHz, such that the subband bandwidths are defined as x (5 / )Q MHz Q ; this ensures that the data rate of the system is

  13. The Effects of Hospital-Level Factors on Patients' Ratings of Physician Communication.

    Science.gov (United States)

    Al-Amin, Mona; Makarem, Suzanne C

    2016-01-01

    The quality of physician-patient communication influences patient health outcomes and satisfaction with healthcare delivery. Yet, little is known about contextual factors that influence physicians' communication with their patients. The main purpose of this article is to examine organizational-level factors that influence patient perceptions of physician communication in inpatient settings. We used the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey and American Hospital Association data to determine patients' ratings of physician communication at the hospital level, and to collect information about hospital-level factors that can potentially influence physician communication. Our sample consisted of 2,756 hospitals. We ran a regression analysis to determine the predictors of poor physician communication, measured as the percentage of patients in a hospital who reported that physicians sometimes or never communicated well. In our sample of hospitals, this percentage ranged between 0% and 21%, with 25% of hospitals receiving poor ratings from more than 6% of patients. Three organizational factors had statistically significant negative associations with physician communication: for-profit ownership, hospital size, and hospitalists providing care in the hospital, On the other hand, the number of full-time-equivalent physicians and dentists per 10,000 inpatient days, physician ownership of the hospital, Medicare share of inpatient days, and public ownership were positively associated with patients' ratings of physician communication. Physician staffing levels are an understudied area in healthcare research. Our findings indicate that physician staffing levels affect the quality of physician communication with patients. Moreover, for-profit and larger hospitals should invest more in physician communication given the role that HCAHPS plays in value-based purchasing.

  14. Who "owns" the network: a case study of new media artists' use of high-bandwidth networks

    Science.gov (United States)

    Lesage, F.

    The objective of this paper is to briefly give an overview of a research project dealing with the social construction of use of information communication technologies among new media artists interested in online collaboration. It will outline the theoretical and methodological tools applied to the case study of the MARCEL Network.

  15. Radiation Hardened, Modulator ASIC for High Data Rate Communications

    Science.gov (United States)

    McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

    2000-01-01

    Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

  16. Revisiting Frequency Reuse towards Supporting Ultra-Reliable Ubiquitous-Rate Communication

    DEFF Research Database (Denmark)

    Park, Jihong; Kim, Dong Min; Popovski, Petar

    2017-01-01

    One of the goals of 5G wireless systems stated by the NGMN alliance is to provide moderate rates (50+ Mbps) everywhere and with very high reliability. We term this service Ultra-Reliable Ubiquitous-Rate Communication (UR2C). This paper investigates the role of frequency reuse in supporting UR2C...... downlink rate. To fairly capture this reliability-rate tradeoff, we propose ubiquitous rate defined as the maximum downlink rate whose required SIR can be achieved with ultra-reliability. By using stochastic geometry, we derive closed-form ubiquitous rate as well as the optimal frequency reuse rules for UR...

  17. High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

    Science.gov (United States)

    Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

    2016-01-01

    We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

  18. On Bit Rate Reduction of Inter-Channel Communication for a Binaural Hearing Assistance System

    Science.gov (United States)

    Chisaki, Yoshifumi; Kawano, Ryouji; Usagawa, Tsuyoshi

    A binaural hearing assistance system based on the frequency domain binaural model has been previously proposed. The system can enhance a signal coming from a specific direction. Since the system utilizes a binaural signal, an inter-channel communication between left and right subsystems is required. The bit rate reduction in inter-channel communication is essential for the detachment of the headset from the processing system. In this paper, the performance of a system which uses a differential pulse code modulation codec is examined and the relationship between the bit rate and sound quality is discussed.

  19. Development of an observer rating scale for caregiver communication in persons with Alzheimer's disease.

    Science.gov (United States)

    Williams, Christine L; Parker, Carlo

    2012-04-01

    There have been few reported studies of communication between spouses with Alzheimer's disease (AD) and related dementia. An observer rating scale for verbal and nonverbal behavior, Verbal-Nonverbal Interaction Scale for Caregivers (VNVIS-CG), was developed to study caregiver communication in couples affected by AD. Preliminary psychometric testing showed that the VNVIS-CG evidenced good reliability and validity. Researchers observed both common caregiver communication strategies and novel strategies that have not been reported in the literature. In future studies, researchers can examine the relationship between caregiver communication and indicators of mental health. Everyday conversations provide fertile ground for nurses to influence family relationships. Nurses can teach caregivers to use strategies that promote engagement and avoid those that discourage participation.

  20. Investigation on the bit error rate performance of 40Gb/s space optical communication system based on BPSK scheme

    Science.gov (United States)

    Li, Mi; Li, Bowen; Zhang, Xuping; Song, Yuejiang; Liu, Jia; Tu, Guojie

    2015-08-01

    Space optical communication technique is attracting increasingly more attention because it owns advantages such as high security and great communication quality compared with microwave communication. As the space optical communication develops, people have already achieved the communication at data rate of Gb/s currently. The next generation for space optical system have goal of the higher data rate of 40Gb/s. However, the traditional optical communication system cannot satisfy it when the data rate of system is at such high extent. This paper will introduce ground optical communication system of 40Gb/s data rate as to achieve the space optical communication at high data rate. Speaking of the data rate of 40Gb/s, we must apply waveguide modulator to modulate the optical signal and magnify this signal by laser amplifier. Moreover, the more sensitive avalanche photodiode (APD) will be as the detector to increase the communication quality. Based on communication system above, we analyze character of communication quality in downlink of space optical communication system when data rate is at the level of 40Gb/s. The bit error rate (BER) performance, an important factor to justify communication quality, versus some parameter ratios is discussed. From results, there exists optimum ratio of gain factor and divergence angle, which shows the best BER performance. We can also increase ratio of receiving diameter and divergence angle for better communication quality. These results can be helpful to comprehend the character of optical communication system at high data rate and contribute to the system design.

  1. Multiband carrierless amplitude/phase modulation for ultra-wideband high data rate wireless communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Altabas, Jose A.

    2016-01-01

    We report on the first experimental demonstration of carrierless amplitude/phase modulation in a flexible multiband approach for ultrawideband high-data-rate wireless communications. An effective bitrate of 2 GB/s is achieved while complying with the restrictions on the effective radiated power e...

  2. Dispersion Monitoring techniques in High Bit-rate Optical Communication Systems

    Institute of Scientific and Technical Information of China (English)

    SANG Xin-zhu; YU Chong-xiu; ZHANG Qi; WANG Xu

    2004-01-01

    For the efficient dynamic dispersion compensation, it is essential to monitor the dispersion accurately. The existing main dispersion monitoring techniques in high bit- rate optical communication systems are presented as well as their operating principles and research progress. The advantages and disadvantages of these methods are analyzed and discussed.

  3. LOW RATE SPACE-TIME TRELLIS CODES IN POWER LIMITED WIRELESS COMMUNICATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Wu Gang; Chen Ming; Wang Haifeng; Cheng Shixin

    2002-01-01

    Space-time trellis codes can achieve the best tradeoff among bandwidth effciency,diversity gain, constellation size and trellis complexity. In this paper, some optimum low rate space-time trellis codes are proposed. Performance analysis and simulation show that the low rate space-time trellis codes outperform space-time block codes concatenated with convolutional code at the same bandwidth effciency, and are more suitable for the power limited wireless communication system.

  4. Modeling and Model Predictive Power and Rate Control of Wireless Communication Networks

    Directory of Open Access Journals (Sweden)

    Cunwu Han

    2014-01-01

    Full Text Available A novel power and rate control system model for wireless communication networks is presented, which includes uncertainties, input constraints, and time-varying delays in both state and control input. A robust delay-dependent model predictive power and rate control method is proposed, and the state feedback control law is obtained by solving an optimization problem that is derived by using linear matrix inequality (LMI techniques. Simulation results are given to illustrate the effectiveness of the proposed method.

  5. Entanglement can increase asymptotic rates of zero-error classical communication over classical channels

    CERN Document Server

    Leung, Debbie; Matthews, William; Ozols, Maris; Roy, Aidan

    2010-01-01

    It is known that the number of different classical messages which can be communicated with a single use of a classical channel with zero probability of decoding error can sometimes be increased by using entanglement shared between sender and receiver. It has been an open question to determine whether entanglement can ever offer an advantage in terms of the zero-error communication rates achievable in the limit of many channel uses. In this paper we show, by explicit examples, that entanglement can indeed increase asymptotic zero-error capacity. Interestingly, in our examples the quantum protocols are based on the root systems of the exceptional Lie groups E7 and E8.

  6. Exponentially enhanced quantum communication rate by multiplexing continuous-variable teleportation

    Science.gov (United States)

    Christ, Andreas; Lupo, Cosmo; Silberhorn, Christine

    2012-08-01

    A major challenge of today's quantum communication systems lies in the transmission of quantum information with high rates over long distances in the presence of unavoidable losses. Thereby the achievable quantum communication rate is fundamentally limited by the amount of energy that can be transmitted per use of the channel. It is hence vital to develop quantum communication protocols that encode quantum information as energy efficiently as possible. To this aim we investigate continuous-variable quantum teleportation as a method of distributing quantum information. We explore the possibility to encode information on multiple optical modes and derive upper and lower bounds on the achievable quantum channel capacities. This analysis enables us to benchmark single-mode versus multi-mode entanglement resources. Our research reveals that multiplexing does not only feature an enhanced energy efficiency, leading to an exponential increase in the achievable quantum communication rates in comparison to single-mode coding, but also yields an improved loss resilience. However, as reliable quantum information transfer is only achieved for entanglement values above a certain threshold a careful optimization of the number of coding modes is needed to obtain the optimal quantum channel capacity.

  7. Development of Radiation-Tolerant, Low Mass, High Bandwidth Flexible Printed Circuit Cables for Particle Detection Applications

    Science.gov (United States)

    McFadden, Neil

    2016-03-01

    Design options for meter long flexible printed circuit cables required for low mass ultra-high speed signal transmission in the high radiation environment at the High Luminosity run of the Large Hadron Collider (LHC) are described. Two dielectric materials were considered in this study, Kapton and a Kapton/Teflon mixture. The design geometry is a differential embedded microstrip with nominal 100 Ω impedance. Minimal mass and maximal radiation hardness are pre-eminent considerations. The long flexible printed circuit cables are characterized in bit error rate tests (BERT), attenuation versus frequency, mechanical response to stress and temperature change, and RLC decomposition. These tests are performed before and after irradiation with 1 MeV neutrons to 2x1016/cm 2 and 800 MeV protons to 2x1016 1 MeV-neq/cm2. A 1.0 m Kapton cable, with bandwidth of 6.22 gigabits per second, 0.03% of a radiation length, and no radiation induced mechanical or electrical degradation is obtained.

  8. Improved achievable secrecy rate of visible light communication with cooperative jamming

    KAUST Repository

    Zaid, Hajar

    2016-02-25

    In this paper we study the problem of securing a visible light communication (VLC) link against passive eavesdropping, with the help of a (friendly) jammer. Differently from radio frequency (RF) communications, VLC imposes a peak amplitude constraint on the input distribution which renders Gaussian inputs not admissible. We provide an achievable secrecy rate that improves upon a recently established one in a concurrent work by Mostafa and Lampe. Our scheme follows from both the secrecy capacity result by Wyner and the artificial noise scheme by Goel and Negi, but using truncated Gaussian input distributions instead of uniform ones. Via numerical results, we show that our secrecy rate outperforms the concurrent rate in different settings. © 2015 IEEE.

  9. [The effect of assertiveness training on communication related factors and personnel turnover rate among hospital nurses].

    Science.gov (United States)

    Kang, Myung Ja; Lee, Haejung

    2006-08-01

    The purpose of this study was to investigate the effects of assertiveness training on nurses' assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate. A non-equivalent control group pretest-posttest design was used in this study. Nurses were assigned into the experimental or control groups, each consisting of 39 nurses. Data was collected between January to March 2004. An 'Assertiveness Training Program' for Nurses developed by Park was used for the study. To emphasize assertiveness practice, 5 practice sessions utilizing ABCDE principles were added to Park's program. To examine the effects of the program, differences between the two groups in assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate were analyzed using ANCOVA. The assertiveness training was effective in improving the nurses' assertiveness behaviors, but was not effective in improving interpersonal relations, reducing the subjects' communication conflicts, changing the conflict management style or reducing their personnel turnover rate. There have been many studies about factors affecting nurses' personnel turnover rates, but few have been done about methods of intervention to reduce the personnel turnover rate. Thus, this study provides a significant contribution in attempting such an intervention from nursing management perspectives.

  10. Communication

    NARCIS (Netherlands)

    Sigafoos, J.; Lancioni, G.E.; O'Reilly, M.F.; Lang, R.; Singh, N.N.; Didden, H.C.M.; Green, V.A.; Marschik, P.B.

    2016-01-01

    Communication disorders are common among people with intellectual disabilities. Consequently, enhancing the communication skills of such individuals is a major intervention priority. This chapter reviews the nature and prevalence of the speech, language, and communication problems associated with

  11. Design of visible light communication system for maintaining uniform data rate

    Science.gov (United States)

    Sung, Jiun-Yu; Lin, Wan-Feng; Wu, Yu-Fu; Chow, Chi-Wai; Yeh, Chien-Hung

    2014-09-01

    Light-emitting diode (LED) is gradually replacing the fluorescent lamp for lighting. Higher modulation bandwidth of LEDs makes the additional application of visible light communication (VLC) possible. Every location of a VLC system should be provided by equal data rate for smooth communication. However, locations away from the LED lamp have less power. These low-power locations have lower signal-to-noise ratio (SNR); and hence lower data rate can be achieved. For achieving high capacity VLC, strategies should be adequately provided to mitigate this problem. Moreover, for some real-time continuous applications, such as video and voice, latency reduction plan should also be considered. In this paper, an orthogonal frequency-division multiplexing access (OFDMA) based system was proposed to solve the above problem. Because we do not use time-division multiplexing access (TDMA) based system, the latency issue can be reduced. The OFDMA based system is also beneficial for large scale operation because the user bandwidth is not reduced by TDM mechanism. Signal-to-noise-plus-interference ratio (SNIR) distribution of the VLC system is designed to ensure uniform and optimal system capacity. Discrete multi-tone (DMT) is used for this VLC system. The DMT subcarriers are bit-loaded depending on the LED frequency response. More subcarriers are allocated for communication at low SNIR locations. Hence, nearly equal data rate can be provided everywhere. Demonstration of 17 Mb/s/LED data rate was provided.

  12. Healthcare Communication Barriers and Self-Rated Health in Older Chinese American Immigrants.

    Science.gov (United States)

    Tsoh, Janice Y; Sentell, Tetine; Gildengorin, Ginny; Le, Gem M; Chan, Elaine; Fung, Lei-Chun; Pasick, Rena J; Stewart, Susan; Wong, Ching; Woo, Kent; Burke, Adam; Wang, Jun; McPhee, Stephen J; Nguyen, Tung T

    2016-08-01

    Older Chinese immigrants are a growing population in the United States who experience multiple healthcare communication barriers such as limited English proficiency and low health literacy. Each of these obstacles has been associated with poor health outcomes but less is known about their effects in combination. This study examined the association between healthcare communication barriers and self-rated health among older Chinese immigrants. Cross-sectional survey data were obtained from 705 Chinese American immigrants ages 50-75 living in San Francisco, California. Communication barriers examined included spoken English proficiency, medical interpreter needs, and health literacy in written health information. The study sample (81 % females, mean age = 62) included 67 % who spoke English poorly or not at all, 34 % who reported needing a medical interpreter, and 37 % who reported "often" or "always" needing assistance to read health information. Two-thirds reported poor self-rated health; many reported having access to racial-concordant (74 %) and language-concordant (86 %) healthcare services. Both poor spoken English proficiency and low health literacy were associated with poor self-rated health, independent of other significant correlates (unemployment, chronic health conditions, and having a primary doctor who was ethnic Chinese). Results revealed that spoken English proficiency and print health literacy are independent communication barriers that are directly associated with health status among elderly Chinese American immigrants. Access to racial- or language-concordant health care services did not appear to resolve these barriers. These findings underscore the importance of addressing both spoken and written healthcare communication needs among older Chinese American immigrants.

  13. Cost effective optical coupling for enhanced rate polymer optical fiber communication

    Science.gov (United States)

    Chandrappan, Jayakrishnan; Zhang, Jing; Ramana, Pamidighantam V.; Lau, John Hon Shing; Kwong, Dim Lee

    2008-02-01

    Recent developments in the short distance communication have made polymer optical fibers (POF) an attractive product in the high speed data communication market. The requirement of a large bandwidth, low cost, light weight and flexibility in installation have placed them over the copper cables especially in applications like home networking and automotives. Since POFs are large core multimoded fibers, their band width is limited by intermodal dispersion. This confines POFs application to low data rate short distance communications. Restrictive mode launchers (RML) and higher order mode strippers placed in the data link helps to reduce the intermodal dispersion. The techniques used to implement these signal conditioners should be simple and cost effective to keep POFs attractive in the short distance communication. In this paper we explore the possibility of integrating the RML and mode stripping elements in the transmitter and receiver package itself. The pre-designed optical signal conditioning elements are projected to get molded in the plastic packages and are fiber plug in modules. This connector less package design, universal to any light source proposes to enhance the data rate and is widely manufacturable at an ease of installation and low cost.

  14. 20-meter underwater wireless optical communication link with 15 Gbps data rate

    KAUST Repository

    Shen, Chao

    2016-10-24

    The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (∼10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.3 mW, we demonstrated a high-speed UWOC link offering a data rate up to 2 Gbps over a 12-meter-long, and 1.5 Gbps over a record 20-meter-long underwater channel. The measured bit-error rate (BER) are 2.8 × 10-5, and 3.0 × 10-3, respectively, which pass well the forward error correction (FEC) criterion. © 2016 Optical Society of America.

  15. Single Carrier Architecture for High Data Rate Wireless PAN Communications System

    CERN Document Server

    Rakotondrainibe, Lahatra; Zaharia, Gheorghe; Grunfelder, Guy; Zein, Ghaïs El

    2010-01-01

    A 60 GHz wireless Gigabit Ethernet (G.E.) communication system is developed at IETR. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fibre (RoF) link is used to ensure the communications in all the rooms of a residential environment. The realized system covers 2 GHz bandwidth. Due to the hardware constraints, a symbol rate at 875 Mbps is attained using simple single carrier architecture. In the baseband (BB) processing block, an original byte/frame synchronization process is designed to provide a smaller value of the preamble missing detection and false alarm probabilities. Bit error rate (BER) measurements have been realized in a large gym for line-of-sight (LOS) conditions. A Tx-Rx distance greater than 30 meters was attained with low BER using high gain antennas and forward error correction RS (255, 239) coding.

  16. 20-meter underwater wireless optical communication link with 1.5 Gbps data rate.

    Science.gov (United States)

    Shen, Chao; Guo, Yujian; Oubei, Hassan M; Ng, Tien Khee; Liu, Guangyu; Park, Ki-Hong; Ho, Kang-Ting; Alouini, Mohamed-Slim; Ooi, Boon S

    2016-10-31

    The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (~10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.3 mW, we demonstrated a high-speed UWOC link offering a data rate up to 2 Gbps over a 12-meter-long, and 1.5 Gbps over a record 20-meter-long underwater channel. The measured bit-error rate (BER) are 2.8 × 10-5, and 3.0 × 10-3, respectively, which pass well the forward error correction (FEC) criterion.

  17. Timing Analysis of Rate Constrained Traffic for the TTEthernet Communication Protocol

    DEFF Research Database (Denmark)

    Tamas-Selicean, Domitian; Pop, Paul; Steiner, Wilfried

    2015-01-01

    proposed, such as TTEthernet, which is the focus of this paper. TTEthernet is suitable for mixed-criticality systems both in the safety and temporal domain. TTEthernet offers three traffic classes: static time-triggered (TT) traffic, dynamic traffic with bounded transmission rate (called "Rate Constrained......Ethernet is a low-cost communication solution offering high transmission speeds. Although its applications extend beyond computer networking, Ethernet is not suitable for real-time and safety-critical systems. To alleviate this, several real-time Ethernet-based communication protocols have been......", RC), and unbounded dynamic traffic ("Best-Effort", BE). In this paper we propose a novel worst-case end-to-end delay analysis of the RC traffic for TTEthernet systems. The proposed technique considerably reduces the pessimism of the analysis, compared to existing approaches. We have evaluated the new...

  18. Existence detection and embedding rate estimation of blended speech in covert speech communications.

    Science.gov (United States)

    Li, Lijuan; Gao, Yong

    2016-01-01

    Covert speech communications may be used by terrorists to commit crimes through Internet. Steganalysis aims to detect secret information in covert communications to prevent crimes. Herein, based on the average zero crossing rate of the odd-even difference (AZCR-OED), a steganalysis algorithm for blended speech is proposed; it can detect the existence and estimate the embedding rate of blended speech. First, the odd-even difference (OED) of the speech signal is calculated and divided into frames. The average zero crossing rate (ZCR) is calculated for each OED frame, and the minimum average ZCR and AZCR-OED of the entire speech signal are extracted as features. Then, a support vector machine classifier is used to determine whether the speech signal is blended. Finally, a voice activity detection algorithm is applied to determine the hidden location of the secret speech and estimate the embedding rate. The results demonstrate that without attack, the detection accuracy can reach 80 % or more when the embedding rate is greater than 10 %, and the estimated embedding rate is similar to the real value. And when some attacks occur, it can also reach relatively high detection accuracy. The algorithm has high performance in terms of accuracy, effectiveness and robustness.

  19. Power Consumption Efficiency Evaluation of Multi-User Full-Duplex Visible Light Communication Systems for Smart Home Technologies

    OpenAIRE

    Muhammad Tabish Niaz; Fatima Imdad; Hyung Seok Kim

    2017-01-01

    Visible light communication (VLC) has recently gained significant academic and industrial attention. VLC has great potential to supplement the functioning of the upcoming radio-frequency (RF)-based 5G networks. It is best suited for home, office, and commercial indoor environments as it provides a high bandwidth and high data rate, and the visible light spectrum is free to use. This paper proposes a multi-user full-duplex VLC system using red-green-blue (RGB), and white emitting diodes (LEDs)...

  20. Low-sampling-rate M-ary multiple access UWB communications in multipath channels

    KAUST Repository

    Alkhodary, Mohammad T.

    2015-08-31

    The desirable characteristics of ultra-wideband (UWB) technology are challenged by formidable sampling frequency, performance degradation in the presence of multi-user interference, and complexity of the receiver due to the channel estimation process. In this paper, a low-rate-sampling technique is used to implement M-ary multiple access UWB communications, in both the detection and channel estimation stages. A novel approach is used for multiple-access-interference (MAI) cancelation for the purpose of channel estimation. Results show reasonable performance of the proposed receiver for different number of users operating many times below Nyquist rate.

  1. Digital modulation and achievable information rates of thru-body haptic communications

    Science.gov (United States)

    Hanisch, Natalie; Pierobon, Massimiliano

    2017-05-01

    The ever increasing biocompatibility and pervasive nature of wearable and implantable devices demand novel sustainable solutions to realize their connectivity, which can impact broad application scenarios such as in the defense, biomedicine, and entertainment fields. Where wireless electromagnetic communications are facing challenges such as device miniaturization, energy scarcity, limited range, and possibility of interception, solutions not only inspired but also based on natural communication means might result into valid alternatives. In this paper, a communication paradigm where digital information is propagated through the nervous system is proposed and analyzed on the basis of achievable information rates. In particular, this paradigm is based on an analytical framework where the response of a system based on haptic (tactile) information transmission and ElectroEncephaloGraphy (EEG)-based reception is modeled and characterized. Computational neuroscience models of the somatosensory signal representation in the brain, coupled with models of the generation and propagation of somatosensory stimulation from skin mechanoreceptors, are employed in this paper to provide a proof-of-concept evaluation of achievable performance in encoding information bits into tactile stimulation, and decoding them from the recorded brain activity. Based on these models, the system is simulated and the resulting data are utilized to train a Support Vector Machine (SVM) classifier, which is finally used to provide a proof-of-concept validation of the system performance in terms of information rates against bit error probability at the reception.

  2. An Adaptive Multiuser Chip-Rate Equalizer for CDMA Underwater Communication System

    Institute of Scientific and Technical Information of China (English)

    HAN Jing; HUANG Jian-guo; SHEN Xiao-hong

    2008-01-01

    Direct-sequence code-division multiple access (CDMA) is considered for multiuser communication network in underwater acoustic channel, where extended multipath and rapid time-variability are encountered. To track and compensate the channel distortion, a decentralized hypothesis-feedback equalization (HFE) algorithm based on chip-rate update has been used[1]. But due to multiple access interference (MAI), its performance suffers degradation. For this reason, successive interference cancellation hypothesis-feedback equalization (SIC-HFE) algorithm is proposed, which combines the capabilities of HFE to track the time-varying channel and SIC implemented by cross-over feedback filters to cancel out the MAI effects between users. Simulation and experiment results show that the proposed algorithm can significantly improve the performance of asynchronous multiuser CDMA underwater communication system.

  3. Modelling the spreading rate of controlled communicable epidemics through an entropy-based thermodynamic model

    CERN Document Server

    Wang, W B; Cao, Z M; Hu, R F

    2013-01-01

    A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics in a city, when the epidemic is governed by controlling efforts of multiple scales so that an entropy is associated with the system. All the epidemic details are factored into a single parameter that is determined by maximizing the rate of entropy production. Despite the simplicity of the final model, it predicts the number of hospitalized cases with a reasonable accuracy, using the data of SARS of the year 2003, once the inflexion point characterizing the effect of multiple controlling efforts is known. This model is supposed to be of potential usefulness since epidemics such as avian influenza like H7H9 in China this year have the risk to become communicable among human beings.

  4. On the Capacity of Rate-Adaptive Packetized Wireless Communication Links under Jamming

    CERN Document Server

    Firouzbakht, Koorosh; Salehi, Masoud

    2012-01-01

    We formulate the interaction between the communicating nodes and an adversary within a game-theoretic context. We show that earlier information-theoretic capacity results for a jammed channel correspond to a pure Nash Equilibrium (NE). However, when both players are allowed to randomize their actions (i.e., coding rate and jamming power) new mixed Nash equilibria appear with surprising properties. We show the existence of a threshold ($J_{TH}$) such that if the jammer average power exceeds $J_{TH}$, the channel capacity at the NE is the same as if the jammer was using its maximum allowable power, $J_{Max}$, all the time. This indicates that randomization significantly advantages powerful jammers. We also show how the NE strategies can be derived, and we provide very simple (e.g., semi-uniform) approximations to the optimal communication and jamming strategies. Such strategies are very simple to implement in current hardware and software.

  5. Experimental implant communication of high data rate video using an ultra wideband radio link.

    Science.gov (United States)

    Chávez-Santiago, Raúl; Balasingham, Ilangko; Bergsland, Jacob; Zahid, Wasim; Takizawa, Kenichi; Miura, Ryu; Li, Huan-Bang

    2013-01-01

    Ultra wideband (UWB) is one of the radio technologies adopted by the IEEE 802.15.6™-2012 standard for on-body communication in body area networks (BANs). However, a number of simulation-based studies suggest the feasibility of using UWB for high data rate implant communication too. This paper presents an experimental verification of said predictions. We carried out radio transmissions of H.264/1280×720 pixels video at 80 Mbps through a UWB multiband orthogonal frequency division multiplexing (MB-OFDM) interface in a porcine chirurgical model. The results demonstrated successful transmission up to a maximum depth of 30 mm in the abdomen and 33 mm in the thorax within the 4.2-4.8 GHz frequency band.

  6. Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE)--A Systematic Review of Rating Scales.

    Science.gov (United States)

    Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

    2016-01-01

    Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students' communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed in order to yield psychometrically

  7. Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE--A Systematic Review of Rating Scales.

    Directory of Open Access Journals (Sweden)

    Musa Cömert

    Full Text Available Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students' communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales.We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed, reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues.Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate.Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed in order to yield

  8. Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE) - A Systematic Review of Rating Scales

    Science.gov (United States)

    Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

    2016-01-01

    Background Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students’ communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. Methods We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Results Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Discussion Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed

  9. Assertive Communication in Condom Negotiation: Insights From Late Adolescent Couples' Subjective Ratings of Self and Partner.

    Science.gov (United States)

    Schmid, Amy; Leonard, Noelle R; Ritchie, Amanda S; Gwadz, Marya V

    2015-07-01

    Assertive communication has been associated with higher levels of condom use among youth using self-report survey methodology. The purpose of this study was to examine the subjective ratings of assertiveness among young, romantically involved couples in the context of a condom negotiation task. Using an innovative video-recall procedure, 32 couples (64 youth) engaged in a videotaped condom negotiation task and then rated self and partners' level of assertiveness. Both individual ratings of assertiveness and couple-level assertiveness were assessed using dyadic hierarchical linear modeling. Individuals' assertiveness was positively associated with condom use. Unexpectedly, the overall level of assertiveness in couples showed a curvilinear association with condom use. Very high and very low assertiveness was associated with lower condom use, whereas moderate levels of assertiveness were associated with higher condom use. Moderate levels of assertiveness during condom negotiation may facilitate condom use in young couples. Increasing condom use among romantic partners may require developing interventions that strengthen youths' ability to engage in assertive communication strategies that balance emotional intimacy with self-advocacy. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  10. Assertive communication in condom negotiation: Insights from late adolescent couples’ subjective ratings of self and partner

    Science.gov (United States)

    Schmid, Amy; Leonard, Noelle R.; Ritchie, Amanda S.; Gwadz, Marya V.

    2015-01-01

    Purpose Assertive communication has been associated with higher levels of condom use among youth using self-report survey methodology. The purpose of this study was to examine the subjective ratings of assertiveness among young, romantically-involved couples in the context of a condom negotiation task. Methods Using an innovative video-recall procedure, 32 couples (64 youth) engaged in a videotaped condom negotiation task and then rated self and partners’ level of assertiveness. Both individual ratings of assertiveness and couple-level assertiveness were assessed using dyadic hierarchical linear modeling. Results Individuals’ assertiveness was positively associated with condom use. Unexpectedly, the overall level of assertiveness in couples showed a curvilinear association with condom use. Very high and very low assertiveness was associated with lower condom use, while moderate levels of assertiveness were associated with higher condom use. Conclusions Moderate levels of assertiveness during condom negotiation may facilitate condom use in young couples. Increasing condom use among romantic partners may require developing interventions that strengthen youths’ ability to engage in assertive communication strategies that balance emotional intimacy with self-advocacy. PMID:25937470

  11. High power, high efficiency millimeter wavelength traveling wave tubes for high rate communications from deep space

    Science.gov (United States)

    Dayton, James A., Jr.

    1991-01-01

    The high-power transmitters needed for high data rate communications from deep space will require a new class of compact, high efficiency traveling wave tubes (TWT's). Many of the recent TWT developments in the microwave frequency range are generically applicable to mm wave devices, in particular much of the technology of computer aided design, cathodes, and multistage depressed collectors. However, because TWT dimensions scale approximately with wavelength, mm wave devices will be physically much smaller with inherently more stringent fabrication tolerances and sensitivity to thermal dissipation.

  12. Evaluating true BCI communication rate through mutual information and language models.

    Science.gov (United States)

    Speier, William; Arnold, Corey; Pouratian, Nader

    2013-01-01

    Brain-computer interface (BCI) systems are a promising means for restoring communication to patients suffering from "locked-in" syndrome. Research to improve system performance primarily focuses on means to overcome the low signal to noise ratio of electroencephalogric (EEG) recordings. However, the literature and methods are difficult to compare due to the array of evaluation metrics and assumptions underlying them, including that: 1) all characters are equally probable, 2) character selection is memoryless, and 3) errors occur completely at random. The standardization of evaluation metrics that more accurately reflect the amount of information contained in BCI language output is critical to make progress. We present a mutual information-based metric that incorporates prior information and a model of systematic errors. The parameters of a system used in one study were re-optimized, showing that the metric used in optimization significantly affects the parameter values chosen and the resulting system performance. The results of 11 BCI communication studies were then evaluated using different metrics, including those previously used in BCI literature and the newly advocated metric. Six studies' results varied based on the metric used for evaluation and the proposed metric produced results that differed from those originally published in two of the studies. Standardizing metrics to accurately reflect the rate of information transmission is critical to properly evaluate and compare BCI communication systems and advance the field in an unbiased manner.

  13. The relationship between communication scores from the USMLE Step 2 Clinical Skills examination and communication ratings for first-year internal medicine residents.

    Science.gov (United States)

    Winward, Marcia L; Lipner, Rebecca S; Johnston, Mary M; Cuddy, Monica M; Clauser, Brian E

    2013-05-01

    This study extends available evidence about the relationship between scores on the Step 2 Clinical Skills (CS) component of the United States Medical Licensing Examination and subsequent performance in residency. It focuses on the relationship between Step 2 CS communication and interpersonal skills scores and communication skills ratings that residency directors assign to residents in their first postgraduate year of internal medicine training. It represents the first large-scale evaluation of the extent to which Step 2 CS communication and interpersonal skills scores can be extrapolated to examinee performance in supervised practice. Hierarchical linear modeling techniques were used to examine the relationships among examinee characteristics, residency program characteristics, and residency-director-provided ratings. The sample comprised 6,306 examinees from 238 internal medicine residency programs who completed Step 2 CS for the first time in 2005 and received ratings during their first year of internal medicine residency training. Although the relationship is modest, Step 2 CS communication and interpersonal skills scores predict communication skills ratings for first-year internal medicine residents after accounting for other factors. The results of this study make a reasonable case that Step 2 CS communication and interpersonal skills scores provide useful information for predicting the level of communication skill that examinees will display in their first year of internal medicine residency training. This finding demonstrates some level of extrapolation from the testing context to behavior in supervised practice, thus providing validity-related evidence for using Step 2 CS communication and interpersonal skills scores in high-stakes decisions.

  14. Strong converse rates for classical communication over thermal and additive noise bosonic channels

    Science.gov (United States)

    Roy Bardhan, Bhaskar; Wilde, Mark M.

    2014-02-01

    We prove that several known upper bounds on the classical capacity of thermal and additive noise bosonic channels are actually strong converse rates. Our results strengthen the interpretation of these upper bounds, in the sense that we now know that the probability of correctly decoding a classical message rapidly converges to 0 in the limit of many channel uses if the communication rate exceeds these upper bounds. In order for these theorems to hold, we need to impose a maximum photon number constraint on the states input to the channel (the strong converse property need not hold if there is only a mean photon number constraint). Our first theorem demonstrates that Koenig and Smith's upper bound on the classical capacity of the thermal bosonic channel is a strong converse rate, and we prove this result by utilizing the structural decomposition of a thermal channel into a pure-loss channel followed by an amplifier channel. Our second theorem demonstrates that Giovannetti et al.'s upper bound on the classical capacity of a thermal bosonic channel corresponds to a strong converse rate, and we prove this result by relating the success probability to the rate, the effective dimension of the output space, and the purity of the channel as measured by the Rényi collision entropy. Finally, we use similar techniques to prove that similar previously known upper bounds on the classical capacity of an additive noise bosonic channel correspond to strong converse rates.

  15. Increasing BCI communication rates with dynamic stopping towards more practical use: an ALS study

    Science.gov (United States)

    Mainsah, B. O.; Collins, L. M.; Colwell, K. A.; Sellers, E. W.; Ryan, D. B.; Caves, K.; Throckmorton, C. S.

    2015-02-01

    Objective. The P300 speller is a brain-computer interface (BCI) that can possibly restore communication abilities to individuals with severe neuromuscular disabilities, such as amyotrophic lateral sclerosis (ALS), by exploiting elicited brain signals in electroencephalography (EEG) data. However, accurate spelling with BCIs is slow due to the need to average data over multiple trials to increase the signal-to-noise ratio (SNR) of the elicited brain signals. Probabilistic approaches to dynamically control data collection have shown improved performance in non-disabled populations; however, validation of these approaches in a target BCI user population has not occurred. Approach. We have developed a data-driven algorithm for the P300 speller based on Bayesian inference that improves spelling time by adaptively selecting the number of trials based on the acute SNR of a user’s EEG data. We further enhanced the algorithm by incorporating information about the user’s language. In this current study, we test and validate the algorithms online in a target BCI user population, by comparing the performance of the dynamic stopping (DS) (or early stopping) algorithms against the current state-of-the-art method, static data collection, where the amount of data collected is fixed prior to online operation. Main results. Results from online testing of the DS algorithms in participants with ALS demonstrate a significant increase in communication rate as measured in bits/min (100-300%), and theoretical bit rate (100-550%), while maintaining selection accuracy. Participants also overwhelmingly preferred the DS algorithms. Significance. We have developed a viable BCI algorithm that has been tested in a target BCI population which has the potential for translation to improve BCI speller performance towards more practical use for communication.

  16. Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

    KAUST Repository

    Smadi, Mahmoud A.

    2012-12-06

    In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate the system performance under very realistic Nakagami-m fading and additive white Gaussian noise channel. On the other hand, the accuracy of the obtained results is verified through running the simulation under a good confidence interval reliability of 95 %. We see that as the number of simulation runs N increases, the simulated error rate becomes closer to the actual one and the confidence interval difference reduces. Hence our results are expected to be of significant practical use for such scenarios. © 2012 Springer Science+Business Media New York.

  17. Data rate enhancement of optical camera communications by compensating inter-frame gaps

    Science.gov (United States)

    Nguyen, Duy Thong; Park, Youngil

    2017-07-01

    Optical camera communications (OCC) is a convenient way of transmitting data between LED lamps and image sensors that are included in most smart devices. Although many schemes have been suggested to increase the data rate of the OCC system, it is still much lower than that of the photodiode-based LiFi system. One major reason of this low data rate is attributed to the inter-frame gap (IFG) of image sensor system, that is, the time gap between consecutive image frames. In this paper, we propose a way to compensate for this IFG efficiently by an interleaved Hamming coding scheme. The proposed scheme is implemented and the performance is measured.

  18. RF and Optical Communications: A Comparison of High Data Rate Returns From Deep Space in the 2020 Timeframe

    Science.gov (United States)

    Williams, W. Dan; Collins, Michael; Boroson, Don M.; Lesh, James; Biswas, Abihijit; Orr, Richard; Schuchman, Leonard; Sands, O. Scott

    2007-01-01

    As NASA proceeds with plans for increased science data return and higher data transfer capacity for science missions, both RF and optical communications are viable candidates for significantly higher-rate communications from deep space to Earth. With the inherent advantages, smaller apertures and larger bandwidths, of optical communications, it is reasonable to expect that at some point in time and combination of increasing distance and data rate, the rapidly emerging optical capabilities would become more advantageous than the more mature and evolving RF techniques. This paper presents a comparison of the burden to a spacecraft by both RF and optical communications systems for data rates of 10, 100, and 1000 Mbps and large distances. Advanced technology for RF and optical communication systems have been considered for projecting capabilities in the 2020 timeframe. For the comparisons drawn, the optical and RF ground terminals were selected to be similar in cost. The RF system selected is composed of forty-five 12-meter antennas, whereas the selected optical system is equivalent to a 10-meter optical telescope. Potential differences in availability are disregarded since the focus of this study is on spacecraft mass and power burden for high-rate mission data, under the assumption that essential communications will be provided by low-rate, high availability RF. For both the RF and optical systems, the required EIRP, for a given data rate and a given distance, was achieved by a design that realized the lowest possible communications subsystem mass (power + aperture) consistent with achieving the lowest technology risk. A key conclusion of this paper is that optical communications has great potential for high data rates and distances of 2.67 AU and beyond, but requires R&D and flight demonstrations to prove out technologies.

  19. Integrating 360° behavior-orientated feedback in communication skills training for medical undergraduates: concept, acceptance and students' self-ratings of communication competence.

    Science.gov (United States)

    Engerer, Cosima; Berberat, Pascal O; Dinkel, Andreas; Rudolph, Baerbel; Sattel, Heribert; Wuensch, Alexander

    2016-10-18

    Feedback is considered a key didactic element in medical education, especially for teaching of communication skills. This study investigates the impact of a best evidence-based practice feedback concept within the context of communication skills training (CST). We evaluate this concept for acceptance and changes in students self-ratings of communication competence. Our CST integrating feedback process comprises a short theoretical introduction presenting standards for good communication and a constructive 360° feedback from three perspectives: feedback from peers, from standardized patients (SPs), and from a trainer. Feed-forward process was facilitated for documenting suggestions for improvements based on observable behaviors to maximize learning benefits. Our CST was applied to four groups of eight or nine students. We assessed the data on students' acceptance using a 6-point scale ranging from very good (1) to poor (6), applied a forced choice question to rank didactic items, and assessed changes in student' self-ratings of their communication competence on a 10-cm visual analogue scale (VAS). Thirty-four medical undergraduates (82 % female, 18 % male) in their first clinical year, with an average age of 21.4 years (SD = 1.0), participated in the new training. The concept achieved high acceptance from good to very good: overall impression (M = 1.56), sufficient interaction for discussion (M = 1.15), and constructive learning atmosphere (M = 1.18). Specific elements, such as practical training with SPs (M = 1.18) and feedback by SPs (M = 1.12), showed highest acceptance. The forced choice ranking placed all feedback elements at the top of the list (feedback (FB) by SPs, rank 2; FB by trainer, rank 3; FB by colleagues, rank 4), whereas theoretical elements were at the bottom (theoretical introduction, rank 7; memory card, rank 9). Overall, student self-ratings of communication competence significantly improved in nine of the ten

  20. Reconfigurable Antennas for High Data Rate Multi-beam Communication Systems

    Science.gov (United States)

    Bernhard, Jennifer T.; Michielssen, Eric

    2005-01-01

    High-speed (2-100 Mb/sec) wireless data communication - whether land- or satellite-based - faces a major challenge: high error rates caused by interference and unpredictable environments. A planar antenna system that can be reconfigured to respond to changing conditions has the potential to dramatically improve data throughput and system reliability. Moreover, new planar antenna designs that reduce array size, weight, and cost can have a significant impact on terrestrial and satellite communication system performance. This research developed new individually-reconfigurable planar antenna array elements that can be adjusted to provide multiple beams while providing increased scan angles and higher aperture efficiency than traditional diffraction-limited arrays. These new elements are microstrip spiral antennas with specialized tuning mechanisms that provide adjustable radiation patterns. We anticipate that these new elements can be used in both large and small arrays for inter-satellite communication as well as tracking of multiple mobile surface-based units. Our work has developed both theoretical descriptions as well as experimental prototypes of the antennas in both single element and array embodiments. The technical summary of the results of this work is divided into six sections: A. Cavity model for analysis and design of pattern reconfigurable antennas; B. Performance of antenna in array configurations for broadside and endfire operation; C. Performance of antenna in array configurations for beam scanning operation; D. Simulation of antennas in infinite phased arrays; E. Demonstration of antenna with commercially-available RF MEMS switches; F. Design of antenna MEMS switch combinations for direct simultaneous fabrication.

  1. 2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode

    KAUST Repository

    Oubei, Hassan M.

    2015-07-30

    We experimentally demonstrate a record high-speed underwater wireless optical communication (UWOC) over 7 m distance using on-off keying non-return-to-zero (OOK-NRZ) modulation scheme. The communication link uses a commercial TO-9 packaged pigtailed 520 nm laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. At 2.3 Gbit/s transmission, the measured bit error rate of the received data is 2.23×10−4, well below the forward error correction (FEC) threshold of 2×10−3 required for error-free operation. The high bandwidth of the LD coupled with high sensitivity APD and optimized operating conditions is the key enabling factor in obtaining high bit rate transmission in our proposed system. To the best of our knowledge, this result presents the highest data rate ever achieved in UWOC systems thus far.

  2. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

    Science.gov (United States)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

    2017-01-01

    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes. PMID:28145513

  3. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

    Science.gov (United States)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

    2017-02-01

    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

  4. Rating Parent-Child Interactions: Joint Engagement, Communication Dynamics, and Shared Topics in Autism, Down Syndrome, and Typical Development

    Science.gov (United States)

    Adamson, Lauren B.; Bakeman, Roger; Deckner, Deborah F.; Nelson, P. Brooke

    2012-01-01

    A battery of 17 rating items were applied to video records of typically-developing toddlers and young children with autism and Down syndrome interacting with their parents during the Communication Play Protocol. This battery provided a reliable and broad view of the joint engagement triad of child, partner, and shared topic. Ratings of the child's…

  5. High-Counting Rate Photon Detectors for Long-Range Space Optical Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Long range, RF space communications do not meet anymore the bandwidth requirements or power constraints of future NASA missions. Optical communications offer the...

  6. Influence of beam wander on bit-error rate in a ground-to-satellite laser uplink communication system.

    Science.gov (United States)

    Ma, Jing; Jiang, Yijun; Tan, Liying; Yu, Siyuan; Du, Wenhe

    2008-11-15

    Based on weak fluctuation theory and the beam-wander model, the bit-error rate of a ground-to-satellite laser uplink communication system is analyzed, in comparison with the condition in which beam wander is not taken into account. Considering the combined effect of scintillation and beam wander, optimum divergence angle and transmitter beam radius for a communication system are researched. Numerical results show that both of them increase with the increment of total link margin and transmitted wavelength. This work can benefit the ground-to-satellite laser uplink communication system design.

  7. Receivers for Diffusion-Based Molecular Communication: Exploiting Memory and Sampling Rate

    CERN Document Server

    Mosayebi, Reza; Gohari, Amin; Kenari, Masoumeh Nasiri; Mitra, Urbashi

    2014-01-01

    In this paper, a diffusion-based molecular communication channel between two nano-machines is considered. The effect of the amount of memory on performance is characterized, and a simple memory-limited decoder is proposed and its performance is shown to be close to that of the best possible imaginable decoder (without any restriction on the computational complexity or its functional form), using Genie-aided upper bounds. This effect is specialized for the case of Molecular Concentration Shift Keying; it is shown that a four-bits memory achieved nearly the same performance as infinite memory. Then a general class of threshold decoders is considered and shown not to be optimal for Poisson channel with memory, unless SNR is higher than a value specified in the paper. Another contribution is to show that receiver sampling at a rate higher than the transmission rate, i.e., a multi-read system, can significantly improve the performance. The associated decision rule for this system is shown to be a weighted sum of t...

  8. Ethnic and gender differentials in non-communicable diseases and self-rated health in Malaysia.

    Directory of Open Access Journals (Sweden)

    Jane K L Teh

    Full Text Available OBJECTIVES: This paper examines the ethnic and gender differentials in high blood pressure (HBP, diabetes, coronary heart disease (CHD, arthritis and asthma among older people in Malaysia, and how these diseases along with other factors affect self-rated health. Differentials in the prevalence of non-communicable diseases among older people are examined in the context of socio-cultural perspectives in multi-ethnic Malaysia. METHODS: Data for this paper are obtained from the 2004 Malaysian Population and Family Survey. The survey covered a nationally representative sample of 3,406 persons aged 50 and over, comprising three main ethnic groups (Malays, Chinese and Indians and all other indigenous groups. Bivariate analyses and hierarchical logistic regression were used in the analyses. RESULTS: Arthritis was the most common non-communicable disease (NCD, followed by HBP, diabetes, asthma and CHD. Older females were more likely than males to have arthritis and HBP, but males were more likely to have asthma. Diabetes and CHD were most prevalent among Indians, while arthritis and HBP were most prevalent among the Indigenous groups. Older people were more likely to report poor health if they suffered from NCD, especially CHD. Controlling for socio-economic, health and lifestyle factors, Chinese were least likely to report poor health, whereas Indians and Indigenous people were more likely to do so. Chinese that had HBP were more likely to report poor health compared to other ethnic groups with the same disease. Among those with arthritis, Indians were more likely to report poor health. CONCLUSION: Perceived health status and prevalence of arthritis, HBP, diabetes, asthma and CHD varied widely across ethnic groups. Promotion of healthy lifestyle, early detection and timely intervention of NCDs affecting different ethnic groups and gender with socio-cultural orientations would go a long way in alleviating the debilitating effects of the common NCDs among

  9. Ethnic and gender differentials in non-communicable diseases and self-rated health in Malaysia.

    Science.gov (United States)

    Teh, Jane K L; Tey, Nai Peng; Ng, Sor Tho

    2014-01-01

    This paper examines the ethnic and gender differentials in high blood pressure (HBP), diabetes, coronary heart disease (CHD), arthritis and asthma among older people in Malaysia, and how these diseases along with other factors affect self-rated health. Differentials in the prevalence of non-communicable diseases among older people are examined in the context of socio-cultural perspectives in multi-ethnic Malaysia. Data for this paper are obtained from the 2004 Malaysian Population and Family Survey. The survey covered a nationally representative sample of 3,406 persons aged 50 and over, comprising three main ethnic groups (Malays, Chinese and Indians) and all other indigenous groups. Bivariate analyses and hierarchical logistic regression were used in the analyses. Arthritis was the most common non-communicable disease (NCD), followed by HBP, diabetes, asthma and CHD. Older females were more likely than males to have arthritis and HBP, but males were more likely to have asthma. Diabetes and CHD were most prevalent among Indians, while arthritis and HBP were most prevalent among the Indigenous groups. Older people were more likely to report poor health if they suffered from NCD, especially CHD. Controlling for socio-economic, health and lifestyle factors, Chinese were least likely to report poor health, whereas Indians and Indigenous people were more likely to do so. Chinese that had HBP were more likely to report poor health compared to other ethnic groups with the same disease. Among those with arthritis, Indians were more likely to report poor health. Perceived health status and prevalence of arthritis, HBP, diabetes, asthma and CHD varied widely across ethnic groups. Promotion of healthy lifestyle, early detection and timely intervention of NCDs affecting different ethnic groups and gender with socio-cultural orientations would go a long way in alleviating the debilitating effects of the common NCDs among older people.

  10. [Monitor of ECG signal and heart rate using a mobile phone with Bluetooth communication protocol].

    Science.gov (United States)

    Becerra-Luna, Brayans; Dávila-García, Rodrigo; Salgado-Rodríguez, Paola; Martínez-Memije, Raúl; Infante-Vázquez, Oscar

    2012-01-01

    To develop a portable signal monitoring equipment for electrocardiography (ECG) and heart rate (HR), communicated with a mobile phone using the Bluetooth (BT) communication protocol for display of the signal on screen. A monitoring system was designed in which the electronic section performs the ECG signal acquisition, as well as amplification, filtering, analog to digital conversion and transmission of the ECG and HR using BT. Two programs were developed for the system. The first one calculates HR through QRS identification and sends the ECG signals and HR to the mobile, and the second program is an application to acquire and display them on the mobile screen. We developed a portable electronic system powered by a 9 volt battery, with amplification and bandwidth meeting the international standards for ECG monitoring. The QRS complex identification was performed using the second derivative algorithm, while the programs allow sending and receiving information from the ECG and HR via BT, and viewing it on the mobile screen. The monitoring is feasible within distances of 15 m and it has been tested in various mobiles telephones of brands Nokia®, Sony Ericsson® and Samsung®. This system shows an alternative for mobile monitoring using BT and Java 2 Micro Edition (J2ME) programming. It allows the register of the ECG trace and HR, and it can be implemented in different phones. Copyright © 2011 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  11. Communications

    Science.gov (United States)

    Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

    2013-01-01

    Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and…

  12. Evaluating a nursing communication skills training course: The relationships between self-rated ability, satisfaction, and actual performance.

    Science.gov (United States)

    Mullan, Barbara A; Kothe, Emily J

    2010-11-01

    Effective communication is a vital component of nursing care, however, nurses often lack the skills to communicate with patients, carers and other health care professionals. Communication skills training programs are frequently used to develop these skills. However, there is a paucity of data on how best to evaluate such courses. The aim of the current study was to evaluate the relationship between student self rating of their own ability and their satisfaction with a nurse training course as compared with an objective measure of communication skills. 209 first year nursing students completed a communication skills program. Both qualitative and quantitative data were collected and associations between measures were investigated. Paired samples t-tests showed significant improvement in self-rated ability over the course of the program. Students generally were very satisfied with the course which was reflected in both qualitative and quantitative measures. However, neither self-rated ability nor satisfaction was significantly correlated with the objective measure of performance, but self-rated ability and satisfaction were highly correlated with one another. The importance of these findings is discussed and implications for nurse education are proposed.

  13. Influence of UAS Pilot Communication and Execution Delay on Controller's Acceptability Ratings of UAS-ATC Interactions

    Science.gov (United States)

    Vu, Kim-Phuong L.; Morales, Gregory; Chiappe, Dan; Strybel, Thomas Z.; Battiste, Vernol; Shively, Jay; Buker, Timothy J

    2013-01-01

    Successful integration of UAS in the NAS will require that UAS interactions with the air traffic management system be similar to interactions between manned aircraft and air traffic management. For example, UAS response times to air traffic controller (ATCo) clearances should be equivalent to those that are currently found to be acceptable with manned aircraft. Prior studies have examined communication delays with manned aircraft. Unfortunately, there is no analogous body of research for UAS. The goal of the present study was to determine how UAS pilot communication and execution delays affect ATCos' acceptability ratings of UAS pilot responses when the UAS is operating in the NAS. Eight radar-certified controllers managed traffic in a modified ZLA sector with one UAS flying in it. In separate scenarios, the UAS pilot verbal communication and execution delays were either short (1.5 s) or long (5 s) and either constant or variable. The ATCo acceptability of UAS pilot communication and execution delays were measured subjectively via post trial ratings. UAS verbal pilot communication delay, were rated as acceptable 92% of the time when the delay was short. This acceptability level decreased to 64% when the delay was long. UAS pilot execution delay had less of an influence on ATCo acceptability ratings in the present stimulation. Implications of these findings for UAS in the NAS integration are discussed.

  14. THz Communications using Photonics and Electronic Devices: the Race to Data-Rate

    Science.gov (United States)

    Ducournau, Guillaume; Szriftgiser, Pascal; Pavanello, Fabio; Peytavit, Emilien; Zaknoune, Mohammed; Bacquet, Denis; Beck, Alexandre; Akalin, Tahsin; Lampin, Jean-François; Lampin, Jean-François

    2015-02-01

    With the mass development of mobile data transfers, wireless communications have recently entered a new area: the carrier frequency is now entering the THz region. After a brief overview of context and key features of THz communication, focus is given on photonic-based THz emitters based on quasi-optic UTC-PDs. A special design of wideband photomixer is presented and its applications for narrow bandwidth THz generation. Using this photomixer, communication links at 200, 400 and 600 GHz are presented.

  15. Advanced Communications Technology Satellite (ACTS) Fade Compensation Protocol Impact on Very Small-Aperture Terminal Bit Error Rate Performance

    Science.gov (United States)

    Cox, Christina B.; Coney, Thom A.

    1999-01-01

    The Advanced Communications Technology Satellite (ACTS) communications system operates at Ka band. ACTS uses an adaptive rain fade compensation protocol to reduce the impact of signal attenuation resulting from propagation effects. The purpose of this paper is to present the results of an analysis characterizing the improvement in VSAT performance provided by this protocol. The metric for performance is VSAT bit error rate (BER) availability. The acceptable availability defined by communication system design specifications is 99.5% for a BER of 5E-7 or better. VSAT BER availabilities with and without rain fade compensation are presented. A comparison shows the improvement in BER availability realized with rain fade compensation. Results are presented for an eight-month period and for 24 months spread over a three-year period. The two time periods represent two different configurations of the fade compensation protocol. Index Terms-Adaptive coding, attenuation, propagation, rain, satellite communication, satellites.

  16. Voice analysis during bad news discussion in oncology: reduced pitch, decreased speaking rate, and nonverbal communication of empathy.

    Science.gov (United States)

    McHenry, Monica; Parker, Patricia A; Baile, Walter F; Lenzi, Renato

    2012-05-01

    This study was designed to determine if differences exist in the speaking rate and pitch of healthcare providers when discussing bad news versus neutral topics, and to assess listeners' ability to perceive voice differences in the absence of speech content. Participants were oncology healthcare providers seeing patients with cancer of unknown primary. The encounters were audio recorded; the information communicated by the oncologist to the patient was identified as neutral or bad news. At least 30 seconds of both bad news and neutral utterances were analyzed; provider voice pitch and speaking rate were measured. The same utterances were subjected to low pass filtering that maintained pitch contours and speaking rate, but eliminated acoustic energy associated with consonants making the samples unintelligible, but with unchanged intonation. Twenty-seven listeners (graduate students in a voice disorders class) listened to the samples and rated them on three features: caring, sympathetic, and competent. All but one provider reduced speaking rate, the majority also reduced pitch in the bad news condition. Listeners perceived a significant difference between the nonverbal characteristics of the providers' voice when performing the two tasks and rated speech produced with the reduced rate and lower pitch as more caring and sympathetic. These results suggest that simultaneous assessment of verbal content and multiparameter prosodic analysis of speech is necessary for a more thorough understanding of the expression and perception of empathy. This information has the potential to contribute to the enhancement of communication training design and of oncologists' communication effectiveness.

  17. Study of dual-directional high rate secure communication systems using chaotic multiple-quantum-well lasers

    Institute of Scientific and Technical Information of China (English)

    Yan Sen-Lin

    2007-01-01

    A scheme of synchronized injection multi-quantum-well (MQW) laser system using optical coupling-feedback is presented for performing chaotic dual-directional secure communication. The performance characterization of chaos masking is investigated theoretically, the equation of synchronization demodulation is deduced and its root is also given. Chaos masking encoding with a rate of 5 Gbit/s and a modulation frequency of 1 GHz, chaos modulation with a rate of 0.2 Gbit/s and a modulation frequency of 0.2 GHz and chaos shifting key with a rate of 0.2 Gbit/s are numerically simulated, separately. The ratio of the signal to the absolute synchronous error and the time for achieving synchronous demodulation are analysed in detail. The results illustrate that the system has stronger privacy and good performances so that it can be applied in chaotic dual-directional high rate secure communications.

  18. Rating Parent-Child Interactions: Joint Engagement, Communication Dynamics, and Shared Topics in Autism, Down Syndrome, and Typical Development

    OpenAIRE

    Adamson, Lauren B.; Bakeman, Roger; Deckner, Deborah F.; Nelson, P. Brooke

    2012-01-01

    A battery of 17 rating items were applied to video records of typically-developing toddlers and young children with autism and Down syndrome interacting with their parents during the Communication Play Protocol. This battery provided a reliable and broad view of the joint engagement triad of child, partner, and shared topic. Ratings of the child’s joint engagement correlated very strongly with state coding of joint engagement and replicated the findings that coordinated joint engagement was l...

  19. COMMUNICATIONS

    CERN Document Server

    A. Petrilli

    2013-01-01

    The organisation of the Open Days at the end of September was the single biggest effort of the CMS Communications Group this year. We would like to thank all volunteers for their hard work to show our Point 5 facilities and explain science and technology to the general public. During two days more than 5,000 people visited the CMS detector underground and profited from the surface activities, which included an exhibition on CMS, a workshop on superconductivity, and an activity for our younger visitors involving wooden Kapla blocks. The Communications Group took advantage of the preparations to produce new CMS posters that can be reused at other venues. Event display images have been produced not just for this occasion but also for other exhibits, education purposes, publications etc. During the Open Days, Gilles Jobin, 2012 winner of CERN Collide@CERN prize, performed his Quantum show in Point 5, with the light installation of German artist Julius von Bismarck. Image 3: CERN Open Days at CMS wel...

  20. COMMUNICATIONS

    CERN Multimedia

    L. Taylor and D. Barney

    2010-01-01

    CMS Centres, Outreach and the 7 TeV Media Event The new CMS Communications group is now established and is addressing three areas that are critical to CMS as it enters the physics operations phase: - Communications Infrastructure, including almost 50 CMS Centres Worldwide, videoconferencing systems, and CERN meeting rooms - Information systems, including the internal and external Web sites as well as the document preparation and management systems - Outreach and Education activities, including working with print, radio and TV media, visits to CMS, and exhibitions. The group has been active in many areas, with the highest priority being accorded to needs of CMS operations and preparations for the major media event planned for 7 TeV collisions. Unfortunately the CMS Centre@CERN suffered a major setback when, on 21st December, a cooling water pipe froze and burst on the floor above the CMS Centre main room. Water poured through the ceiling, flooding the floor and soaking some of the consoles, before e...

  1. Routing and Allocation of Unmanned Aerial Vehicles with Communication Considerations

    Science.gov (United States)

    Sabo, Chelsea

    Cooperative Unmanned Aerial Vehicles (UAV) teams are anticipated to provide much needed support for human intelligence, measurement and signature intelligence, signals intelligence, imagery intelligence, and open source intelligence through algorithms, software, and automation. Therefore, it is necessary to have autonomous algorithms that route multiple UAVs effectively and efficiently throughout missions and that these are realizable in the real-world given the associated uncertainties. Current routing strategies ignore communication constraints altogether. In reality, communication can be restricted by bandwidth, line-of-sight, maximum communication ranges, or a need for uninterrupted transmission. Generating autonomous algorithms that work effectively around these communication constraints is key for the future of UAV surveillance applications. In this work, both current and new routing strategies for UAVS are analyzed to determine how communications impact efficiency of information return. It is shown that under certain communication conditions, a new approach on routing can be more efficient than typically adopted strategies. This new approach defines and presents a new formulation based on a minimum delivery latency objective function. The problem is formulated such that information is not considered delivered until it is returned back to a high-bandwidth connection (depot) which is common when communication is restricted. The size of the region is shown to be dependent upon distance between requests, UAV bandwidth, UAV velocity, and data size, but it was shown that for large-sized data, long distances, and low bandwidth, it is generally better to route UAVs with this new minimum latency objective. With the added decision of when to deliver information to a high-bandwidth connection, an already computationally complex problem grows even faster. Because of scaling issues, a heuristic algorithm was developed that was constructed by analyzing the optimal

  2. A web-based team-oriented medical error communication assessment tool: development, preliminary reliability, validity, and user ratings.

    Science.gov (United States)

    Kim, Sara; Brock, Doug; Prouty, Carolyn D; Odegard, Peggy Soule; Shannon, Sarah E; Robins, Lynne; Boggs, Jim G; Clark, Fiona J; Gallagher, Thomas

    2011-01-01

    Multiple-choice exams are not well suited for assessing communication skills. Standardized patient assessments are costly and patient and peer assessments are often biased. Web-based assessment using video content offers the possibility of reliable, valid, and cost-efficient means for measuring complex communication skills, including interprofessional communication. We report development of the Web-based Team-Oriented Medical Error Communication Assessment Tool, which uses videotaped cases for assessing skills in error disclosure and team communication. Steps in development included (a) defining communication behaviors, (b) creating scenarios, (c) developing scripts, (d) filming video with professional actors, and (e) writing assessment questions targeting team communication during planning and error disclosure. Using valid data from 78 participants in the intervention group, coefficient alpha estimates of internal consistency were calculated based on the Likert-scale questions and ranged from α=.79 to α=.89 for each set of 7 Likert-type discussion/planning items and from α=.70 to α=.86 for each set of 8 Likert-type disclosure items. The preliminary test-retest Pearson correlation based on the scores of the intervention group was r=.59 for discussion/planning and r=.25 for error disclosure sections, respectively. Content validity was established through reliance on empirically driven published principles of effective disclosure as well as integration of expert views across all aspects of the development process. In addition, data from 122 medicine and surgical physicians and nurses showed high ratings for video quality (4.3 of 5.0), acting (4.3), and case content (4.5). Web assessment of communication skills appears promising. Physicians and nurses across specialties respond favorably to the tool.

  3. Error rates in forensic DNA analysis: definition, numbers, impact and communication.

    Science.gov (United States)

    Kloosterman, Ate; Sjerps, Marjan; Quak, Astrid

    2014-09-01

    Forensic DNA casework is currently regarded as one of the most important types of forensic evidence, and important decisions in intelligence and justice are based on it. However, errors occasionally occur and may have very serious consequences. In other domains, error rates have been defined and published. The forensic domain is lagging behind concerning this transparency for various reasons. In this paper we provide definitions and observed frequencies for different types of errors at the Human Biological Traces Department of the Netherlands Forensic Institute (NFI) over the years 2008-2012. Furthermore, we assess their actual and potential impact and describe how the NFI deals with the communication of these numbers to the legal justice system. We conclude that the observed relative frequency of quality failures is comparable to studies from clinical laboratories and genetic testing centres. Furthermore, this frequency is constant over the five-year study period. The most common causes of failures related to the laboratory process were contamination and human error. Most human errors could be corrected, whereas gross contamination in crime samples often resulted in irreversible consequences. Hence this type of contamination is identified as the most significant source of error. Of the known contamination incidents, most were detected by the NFI quality control system before the report was issued to the authorities, and thus did not lead to flawed decisions like false convictions. However in a very limited number of cases crucial errors were detected after the report was issued, sometimes with severe consequences. Many of these errors were made in the post-analytical phase. The error rates reported in this paper are useful for quality improvement and benchmarking, and contribute to an open research culture that promotes public trust. However, they are irrelevant in the context of a particular case. Here case-specific probabilities of undetected errors are needed

  4. Simulation and Analysis of Router Buffer Requirements in High Bandwidth-Delay Networks%高带宽延迟网络中路由器缓存需求的仿真分析

    Institute of Scientific and Technical Information of China (English)

    王建新; 李春泉; 黄家玮

    2009-01-01

    In order to meet the requirement for router buffer size in high bandwidth-delay networks, five typical buffer-sizing methods based on the TCP model are analyzed via the NS2 simulation, and the effects of various high-speed TCP protocols and active queue management (AQM) mechanisms on the buffer-sizing methods in high bandwidth-delay networks are discussed in detail. Simulated results show that: (1) the buffer-sizing methods based on different assumptions adapt to different network environments; (2) the validity of the existing cache mechanisms depends on the ratio of the bandwidth-delay product to the flow number; and (3) when high-speed TCP protocols and AQM mechanisms are used in high bandwidth-delay networks, the buffer size is greatly reduced.%文中针对当今高带宽延迟网络下路由器缓存大小的需求问题,通过NS2仿真实验,对基于TCP协议模型的5种典型的缓存设置方法展开研究,着重分析了在高带宽延迟网络下各种高速TCP协议和主动队列管理(AQM)机制对各种缓存设置方法的影响.仿真实验表明:基于不同假设前提的缓存设置方法适应于不同的网络负载环境;缓存机制的选择取决于网络带宽延迟乘积与流数的比值;在高带宽延迟网络下,当采用高速TCP协议和AQM机制时,缓存需求可以大大减小.

  5. Rain rate intensity model for communication link design across the Indian region

    Science.gov (United States)

    Kilaru, Aravind; Kotamraju, Sarat K.; Avlonitis, Nicholas; Sri Kavya, K. Ch.

    2016-07-01

    A study on rain statistical parameters such as one minute rain intensity, possible number of minute occurrences with respective percentage of time in a year has been evaluated for the purpose of communication link design at Ka, Q, V bands as well as at Free-Space Optical communication links (FSO). To understand possible outage period of a communication links due to rainfall and to investigate rainfall pattern, Automatic Weather Station (AWS) rainfall data is analysed due its ample presence across India. The climates of the examined AWS regions vary from desert to cold climate, heavy rainfall to variable rainfall regions, cyclone effective regions, mountain and coastal regions. In this way a complete and unbiased picture of the rainfall statistics for Indian region is evaluated. The analysed AWS data gives insight into yearly accumulated rainfall, maximum hourly accumulated rainfall, mean hourly accumulated rainfall, number of rainy days and number of rainy hours from 668 AWS locations. Using probability density function the one minute rainfall measurements at KL University is integrated with AWS measurements for estimating number of rain occurrences in terms of one minute rain intensity for annual rainfall accumulated between 100 mm and 5000 mm to give an insight into possible one minute accumulation pattern in an hour for comprehensive analysis of rainfall influence on a communication link for design engineers. So that low availability communications links at higher frequencies can be transformed into a reliable and economically feasible communication links for implementing High Throughput Services (HTS).

  6. Laser Communication Experiments with Artemis Satellite

    Science.gov (United States)

    Kuzkov, Sergii; Sodnik, Zoran; Kuzkov, Volodymyr

    2013-10-01

    In November 2001, the European Space Agency (ESA) established the world-first inter-satellite laser communication link between the geostationary ARTEMIS satellite and the low Earth orbiting (LEO) SPOT-4 Earth observation satellite, demonstrating data rates of 50 Mbps. In 2006, the Japanese Space Agency launched the KIRARI (OICETS) LEO satellite with a compatible laser communication terminal and bidirectional laser communication links (50 Mbps and 2 Mbps) were successfully realized between KIRARI and ARTEMIS. ESA is now developing the European Data Relay Satellite (EDRS) system, which will use laser communication technology to transmit data between the Sentinel 1 and 2 satellites in LEO to two geostationary satellites (EDRS-A and EDRS-C) at data rates of 1.8 Gbps. As the data handling capabilities of state-of-the-art telecommunication satellites in GEO increase so is the demand for the feeder-link bandwidth to be transmitted from ground. This is why there is an increasing interest in developing high bandwidth ground-to-space laser communication systems working through atmosphere. In 2002, the Main Astronomical Observatory (MAO) started the development of its own laser communication system for its 0.7m AZT-2 telescope, located in Kyiv, Ukraine. The work was supported by the National Space Agency of Ukraine and by ESA. MAO developed a highly accurate computerized tracking system for AZT-2 telescope and a compact laser communication package called LACES (Laser Atmosphere and Communication Experiments with Satellites). The LACES instrument includes a camera of the pointing and tracking subsystems, a receiver module, a laser transmitter module, a tip/tilt atmospheric turbulence compensation subsystem, a bit error rate tester module and other optical and electronic components. The principal subsystems are mounted on a platform, which is located at the Cassegrain focus of the AZT-2 telescope. All systems were tested with the laser communication payload on-board ARTEMIS and

  7. Shallow-water acoustic communication with high bit rate BPSK signals

    NARCIS (Netherlands)

    Gijzen, M.B. van; Walree, P.A. van

    2000-01-01

    BPSK signals have been defined for transmission through a shallow-water acoustic communication channel. The signals were accompanied by two displaced carriers to facilitate carrier recovery. To correct for the adverse effects of time spreading, a pseudo-random learning sequence was transmitted ahead

  8. Design and Evaluation of 10-Gbps Inter-satellite Optical Wireless Communication Link for Improved Performance

    Science.gov (United States)

    Gupta, Amit; Nagpal, Shaina

    2017-05-01

    Inter-satellite optical wireless communication (IsOWC) systems can be chosen over existing microwave satellite systems for deploying in space in the future due to their high bandwidth, small size, light weight, low power and low cost. However, the IsOWC system suffers from various attenuations due to weather conditions, turbulence or scintillations which limit its performance and decreases its availability. So, in order to improve the performance, IsOWC system using directly modulated laser source is proposed in this work. The system is designed and evaluated to be suitable for high data rate transmissions up to 10 Gbps. The performance of the system is investigated in order to reduce the cost and complexity of link and improving the quality of information signal. Further the proposed IsOWC system is analysed using BER analyser, power meter and oscilloscope Visualizer.

  9. Evaluation of Heart Rate Assessment Timing, Communication, Accuracy, and Clinical Decision-Making during High Fidelity Simulation of Neonatal Resuscitation

    Directory of Open Access Journals (Sweden)

    Win Boon

    2014-01-01

    Full Text Available Objective. Accurate heart rate (HR determination during neonatal resuscitation (NR informs subsequent NR actions. This study’s objective was to evaluate HR determination timeliness, communication, and accuracy during high fidelity NR simulations that house officers completed during neonatal intensive care unit (NICU rotations. Methods. In 2010, house officers in NICU rotations completed high fidelity NR simulation. We reviewed 80 house officers’ videotaped performance on their initial high fidelity simulation session, prior to training and performance debriefing. We calculated the proportion of cases congruent with NR guidelines, using chi square analysis to evaluate performance across HR ranges relevant to NR decision-making: <60, 60–99, and ≥100 beats per minute (bpm. Results. 87% used umbilical cord palpation, 57% initiated HR assessment within 30 seconds, 70% were accurate, and 74% were communicated appropriately. HR determination accuracy varied significantly across HR ranges, with 87%, 57%, and 68% for HR <60, 60–99, and ≥100 bpm, respectively (P<0.001. Conclusions. Timeliness, communication, and accuracy of house officers’ HR determination are suboptimal, particularly for HR 60–100 bpm, which might lead to inappropriate decision-making and NR care. Training implications include emphasizing more accurate HR determination methods, better communication, and improved HR interpretation during NR.

  10. The performance of coherent receiver controlled by the phase lock loop in dual rate free-space laser communication

    Science.gov (United States)

    Ma, Xiaoping; Sun, Jianfeng; Hou, Peipei; Lu, Wei; Xu, Qian; Liu, Liren

    2015-09-01

    The technique of differential phase shift keying(DPSK) modulation is applied into demodulating phase information in the coherent optical receiver. The dual rate free-space receiving structure on the base of Mach-Zehnder delay interferometer with the lens is used suitably for differential delay which is equal to the one bit corresponding to a certain data rate. Delay distance at the interference receiver is varied with transmission rata from satellite to ground. Differential information is obtained by the subtraction of the two successive wave-front phases when made to interfere. The phase demodulation is extremely sensitive to phase fluctuation. Because of the incident light through atmospheric turbulence, the wave-front of optical signal became jittered in the temporal and spatial domain rapidly. In the paper, the dual rate free-space laser communication receiver for phase lock to stable signal light phase is proposed, increasing the homodyne efficiency and decreasing the bit error rate.

  11. A Review on Inter-satellite Link in Inter-satellite Optical Wireless Communication

    Science.gov (United States)

    Arora, Heena; Goyal, Rakesh

    2017-06-01

    In this paper, inter-satellite optical wireless communication (IsOWC) system is proposed, one of the imperative utilizations of free space optics/wireless space optics (FSO)/WSO innovation. IsOWC frameworks give a high bandwidth, small size, small weight, low power and minimal effort different option for present microwave satellite frameworks. Optical communications systems have evolved from lengthy fibers to powerful wireless system. This has hence resulted in the use of optical wireless communication system in space communications. As the quantity of satellites circling the Earth expands year by year, a system between the satellites gives a strategy to them to correspond with one another. This is vital for satellites to send data to each other furthermore to hand off the data starting with one satellite then onto the next satellite and after that to the ground stations. By utilizing laser satellite correspondence, the satellites can be joined with information rates up to a few Gbps. The system performance including bit rates, input power, wavelength and distance on an inter-satellite link was analyzed. Various issues such as bit rates, input power, wavelength and distance were presented in IsOWC.

  12. Bit error rate estimation for galvanic-type intra-body communication using experimental eye-diagram and jitter characteristics.

    Science.gov (United States)

    Li, Jia Wen; Chen, Xi Mei; Pun, Sio Hang; Mak, Peng Un; Gao, Yue Ming; Vai, Mang I; Du, Min

    2013-01-01

    Bit error rate (BER), which indicates the reliability of communicate channel, is one of the most important values in all kinds of communication system, including intra-body communication (IBC). In order to know more about IBC channel, this paper presents a new method of BER estimation for galvanic-type IBC using experimental eye-diagram and jitter characteristics. To lay the foundation for our methodology, the fundamental relationships between eye-diagram, jitter and BER are first reviewed. Then experiments based on human lower arm IBC are carried out using quadrature phase shift keying (QPSK) modulation scheme and 500 KHz carries frequency. In our IBC experiments, the symbol rate is from 10 Ksps to 100 Ksps, with two transmitted power settings, 0 dBm and -5 dBm. Finally, the BER results were obtained after calculation by experimental data through the relationships among eye-diagram, jitter and BER. These results are then compared with theoretical values and they show good agreement, especially when SNR is between 6 dB to 11 dB. Additionally, these results demonstrate assuming the noise of galvanic-type IBC channel as Additive White Gaussian Noise (AWGN) in previous study is applicable.

  13. High-Bandwidth, High-Efficiency Envelope Tracking Power Supply for 40W RF Power Amplifier Using Paralleled Bandpass Current Sources

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a high-performance power conversion scheme for power supply applications that require very high output voltage slew rates (dV/dt). The concept is to parallel 2 switching bandpass current sources, each optimized for its passband frequency space and the expected load current....... The principle is demonstrated with a power supply, designed for supplying a 40 W linear RF power amplifier for efficient amplification of a 16-QAM modulated data stream...

  14. High-Rate Communications Outage Recorder Operations for Optimal Payload and Science Telemetry Management Onboard the International Space Station

    Science.gov (United States)

    Shell, Michael T.; McElyea, Richard M. (Technical Monitor)

    2002-01-01

    All International Space Station (ISS) Ku-band telemetry transmits through the High-Rate Communications Outage Recorder (HCOR). The HCOR provides the recording and playback capability for all payload, science, and International Partner data streams transmitting through NASA's Ku-band antenna system. The HCOR is a solid-state memory recorder that provides recording capability to record all eight ISS high-rate data during ISS Loss-of-Signal periods. NASA payloads in the Destiny module are prime users of the HCOR; however, NASDA and ESA will also utilize the HCOR for data capture and playback of their high data rate links from the Kibo and Columbus modules. Marshall Space Flight Center's Payload Operations Integration Center manages the HCOR for nominal functions, including system configurations and playback operations. The purpose of this paper is to present the nominal operations plan for the HCOR and the plans for handling contingency operations affecting payload operations. In addition, the paper will address HCOR operation limitations and the expected effects on payload operations. The HCOR is manifested for ISS delivery on flight 9A with the HCOR backup manifested on flight 11A. The HCOR replaces the Medium-Rate Communications Outage Recorder (MCOR), which has supported payloads since flight 5A.1.

  15. Prediction Method for Rain Rate and Rain Propagation Attenuation for K-Band Satellite Communications Links in Tropical Areas

    Directory of Open Access Journals (Sweden)

    Baso Maruddani

    2015-01-01

    Full Text Available This paper deals with the prediction method using hidden Markov model (HMM for rain rate and rain propagation attenuation for K-band satellite communication link at tropical area. As is well known, the K-band frequency is susceptible of being affected by atmospheric condition, especially in rainy condition. The wavelength of K-band frequency which approaches to the size of rain droplet causes the signal strength is easily attenuated and absorbed by the rain droplet. In order to keep the quality of system performance for K-band satellite communication link, therefore a special attention has to be paid for rain rate and rain propagation attenuation. Thus, a prediction method for rain rate and rain propagation attenuation based on HMM is developed to process the measurement data. The measured and predicted data are then compared with the ITU-R recommendation. From the result, it is shown that the measured and predicted data show similarity with the model of ITU-R P.837-5 recommendation for rain rate and the model of ITU-R P.618-10 recommendation for rain propagation attenuation. Meanwhile, statistical data for measured and predicted data such as fade duration and interfade duration have insignificant discrepancy with the model of ITU-R P.1623-1 recommendation.

  16. New high performance SAW convolvers used in high bit rate and wideband spread spectrum CDMA communications system.

    Science.gov (United States)

    Hikita, M; Takubo, C; Asai, K

    2000-01-01

    New surface acoustic wave (SAW) convolver structures with high conversion efficiency and self-temperature compensation characteristics have been developed. Strong piezoelectric substrates, regardless of temperature coefficients of delay (TCD), can be used in these convolvers. New demodulation techniques using the developed SAW convolver for high bit rate and wideband spread spectrum code division multiple access (CDMA) communications have also been developed. I- and Q-channel demodulation data can be derived directly from binary phase shift keying (BPSK) or quadri-phase shift keying (QPSK) CDMA signals. In an experiment using a 128 degrees YX-LiNbO(3) substrate, CDMA signals of 9 Mbps (megabits per second) with 60 Mcps (megachips per second) spread by 13-chip Barker code and 11 Mbps with 140 Mcps spread by 25-chip Shiba's code were clearly demodulated, demonstrating the effectiveness of these techniques for use in future CDMA communications.

  17. Interspecialty communication supported by health information technology associated with lower hospitalization rates for ambulatory care-sensitive conditions.

    Science.gov (United States)

    O'Malley, Ann S; Reschovsky, James D; Saiontz-Martinez, Cynthia

    2015-01-01

    Practice tools such as health information technology (HIT) have the potential to support care processes, such as communication between health care providers, and influence care for "ambulatory care-sensitive conditions" (ACSCs). ACSCs are conditions for which good outpatient care can potentially prevent the need for hospitalization. To date, associations between such primary care practice capabilities and hospitalizations for ambulatory care-sensitive conditions have been primarily limited to smaller, local studies or unique delivery systems rather than nationally representative studies of primary care physicians in the United States. We analyzed a nationally representative sample of 1,819 primary care physicians who responded to the Center for Studying Health System Change's Physician Survey. We linked 3 years of Medicare claims (2007 to 2009) with these primary care physician survey respondents. This linkage resulted in the identification of 123,760 beneficiaries with one or more of 4 ambulatory care-sensitive chronic conditions (diabetes, chronic obstructive pulmonary disease, asthma, and congestive heart failure) for whom these physicians served as the usual provider. Key independent variables of interest were physicians' practice capabilities, including communication with specialists, use of care managers, participation in quality and performance measurement, use of patient registries, and HIT use. The dependent variable was a summary measure of ambulatory care-sensitive hospitalizations for one or more of these 4 conditions. Higher provider-reported levels of communication between primary care and specialist physicians were associated with lower rates of potentially avoidable hospitalizations. While there was no significant main effect between HIT use and ACSC hospitalizations, the associations between interspecialty communication and ACSC hospitalizations were magnified in the presence of higher HIT use. For example, patients in practices with both the

  18. Global synchronization of complex dynamical networks through digital communication with limited data rate.

    Science.gov (United States)

    Wang, Yan-Wu; Bian, Tao; Xiao, Jiang-Wen; Wen, Changyun

    2015-10-01

    This paper studies the global synchronization of complex dynamical network (CDN) under digital communication with limited bandwidth. To realize the digital communication, the so-called uniform-quantizer-sets are introduced to quantize the states of nodes, which are then encoded and decoded by newly designed encoders and decoders. To meet the requirement of the bandwidth constraint, a scaling function is utilized to guarantee the quantizers having bounded inputs and thus achieving bounded real-time quantization levels. Moreover, a new type of vector norm is introduced to simplify the expression of the bandwidth limit. Through mathematical induction, a sufficient condition is derived to ensure global synchronization of the CDNs. The lower bound on the sum of the real-time quantization levels is analyzed for different cases. Optimization method is employed to relax the requirements on the network topology and to determine the minimum of such lower bound for each case, respectively. Simulation examples are also presented to illustrate the established results.

  19. Participants' ratings of male physicians who vary in race and communication style.

    Science.gov (United States)

    Aruguete, Mara S; Roberts, Carlos A

    2002-12-01

    Research has shown minorities receive lower quality health care than White persons even with socioeconomic conditions controlled. This difference may partially be related to racially biased attitudes and impaired communication in interracial relationships between physicians and patients. This study investigated the effect of physicians' race and nonverbal communication style on participants' evaluations. Patients at a local health clinic were participants (N = 116: 84% Black, 16% White). Each participant viewed one of four videotapes showing varied race of a physician (Black or White) and the physician's nonverbal behavior (expressing concern or distance), and then completed a questionnaire evaluating the depicted physician. Overall, participants did not give significantly different preferences for physicians of the same race. However, participants' evaluations were significantly associated with physicians' nonverbal style. Nonverbal concern was associated with highest satisfaction, trust, self-disclosure, recall of information, likelihood of recommending the physician, and intent to comply with the physician's recommendations. When male and female participants were compared, preference for a physician of the same race was found only among male participants who viewed verbally distant physicians. Results suggest that social skills are more important than race in shaping patients' perceptions of physicians.

  20. Burst Format Design for Optimum Joint Estimation of Doppler-Shift and Doppler-Rate in Packet Satellite Communications

    Directory of Open Access Journals (Sweden)

    Luca Giugno

    2007-05-01

    Full Text Available This paper considers the problem of optimizing the burst format of packet transmission to perform enhanced-accuracy estimation of Doppler-shift and Doppler-rate of the carrier of the received signal, due to relative motion between the transmitter and the receiver. Two novel burst formats that minimize the Doppler-shift and the Doppler-rate Cramér-Rao bounds (CRBs for the joint estimation of carrier phase/Doppler-shift and of the Doppler-rate are derived, and a data-aided (DA estimation algorithm suitable for each optimal burst format is presented. Performance of the newly derived estimators is evaluated by analysis and by simulation, showing that such algorithms attain their relevant CRBs with very low complexity, so that they can be directly embedded into new-generation digital modems for satellite communications at low SNR.

  1. LETTERS AND COMMENTS: Self-initiation of EEG-based brain computer communication using the heart rate response

    Science.gov (United States)

    Scherer, R.; Müller-Putz, G. R.; Pfurtscheller, G.

    2007-12-01

    Self-initiation, that is the ability of a brain-computer interface (BCI) user to autonomously switch on and off the system, is a very important issue. In this work we analyze whether the respiratory heart rate response, induced by brisk inspiration, can be used as an additional communication channel. After only 20 min of feedback training, ten healthy subjects were able to self-initiate and operate a 4-class steady-state visual evoked potential-based (SSVEP) BCI by using one bipolar ECG and one bipolar EEG channel only. Threshold detection was used to measure a beat-to-beat heart rate increase. Despite this simple method, during a 30 min evaluation period on average only 2.9 non-intentional switches (heart rate changes) were detected.

  2. Laser Rate Equation Based Filtering for Carrier Recovery in Characterization and Communication

    DEFF Research Database (Denmark)

    Piels, Molly; Iglesias Olmedo, Miguel; Xue, Weiqi;

    2015-01-01

    We formulate a semiconductor laser rate equationbased approach to carrier recovery in a Bayesian filtering framework. Filter stability and the effect of model inaccuracies (unknown or un-useable rate equation coefficients) are discussed. Two potential application areas are explored: laser charact...

  3. High-bandwidth AFM-based rheology is a sensitive indicator of early cartilage aggrecan degradation relevant to mouse models of osteoarthritis.

    Science.gov (United States)

    Nia, Hadi T; Gauci, Stephanie J; Azadi, Mojtaba; Hung, Han-Hwa; Frank, Eliot; Fosang, Amanda J; Ortiz, Christine; Grodzinsky, Alan J

    2015-01-02

    Murine models of osteoarthritis (OA) and post-traumatic OA have been widely used to study the development and progression of these diseases using genetically engineered mouse strains along with surgical or biochemical interventions. However, due to the small size and thickness of murine cartilage, the relationship between mechanical properties, molecular structure and cartilage composition has not been well studied. We adapted a recently developed AFM-based nano-rheology system to probe the dynamic nanomechanical properties of murine cartilage over a wide frequency range of 1 Hz to 10 kHz, and studied the role of glycosaminoglycan (GAG) on the dynamic modulus and poroelastic properties of murine femoral cartilage. We showed that poroelastic properties, highlighting fluid-solid interactions, are more sensitive indicators of loss of mechanical function compared to equilibrium properties in which fluid flow is negligible. These fluid-flow-dependent properties include the hydraulic permeability (an indicator of the resistance of matrix to fluid flow) and the high frequency modulus, obtained at high rates of loading relevant to jumping and impact injury in vivo. Utilizing a fibril-reinforced finite element model, we estimated the poroelastic properties of mouse cartilage over a wide range of loading rates for the first time, and show that the hydraulic permeability increased by a factor ~16 from knormal=7.80×10(-16)±1.3×10(-16) m(4)/N s to kGAG-depleted=1.26×10(-14)±6.73×10(-15) m(4)/N s after GAG depletion. The high-frequency modulus, which is related to fluid pressurization and the fibrillar network, decreased significantly after GAG depletion. In contrast, the equilibrium modulus, which is fluid-flow independent, did not show a statistically significant alteration following GAG depletion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Spectrum slicing WDM for FSO communication systems under the heavy rain weather

    Science.gov (United States)

    Rashidi, Florence; He, Jing; Chen, Lin

    2017-03-01

    In the paper, the spectrum sliced wavelength division multiplexed (SS-WDM) is proposed for Free Space Optic (FSO) communication in the heavy rain weather of Changsha, China. The study seeks to investigate the possibility of communication links up to 3 km with 1.56 Gb/s data rate on the wavelength of 1550 nm. A WDM-Demux is used to operate as slicing system. The SS-WDM-FSO system has been realized and investigated for 4 channels with data rate up to 1.56 Gb/s using a continue wave (CW) laser source with and without SS technique. The simulation results show that, using the SS-WDM technique, a data rate of 1.56 Gb/s is achieved over a transmission distance of 2.5 km with the bit error ratio of nearly 9.816×10-11 and the power of 0 dBm. Meanwhile transmitting over FSO channel using WDM without spectrum slicing, the sampled data rate is achieved over a transmission distance of 2.5 km with the BER of 10-3 on power supply of 10 dBm. In addition, the proposed SS-WDM scheme can improve the FSO communication system performance compared to WDM-FSO scheme. Also, its adaptive and scalable network architecture support high bandwidth and wide coverage area over the heavy rain weather, without power penalty.

  5. Left-ventricular peak ejection rate, filling rate, and ejection fraction--frame rate requirements at rest and exercise: concise communication.

    Science.gov (United States)

    Bacharach, S L; Green, M V; Borer, J S; Hyde, J E; Farkas, S P; Johnston, G S

    1979-03-01

    The effect of framing rate on the measurement of left-ventricular (LV) ejection fraction (EF), peak ejection rate (PER), and peak filling rate (PFR) was evaluated at rest and during exercise in 11 normal subjects and 21 patients who underwent gated equilibrium blood-pool imaging. Left-ventricular time-activity curves were obtained in each subject, at rest and during stress, at temporal resolutions of 10, 20, 30, 40, and 50 msec per frame. Ejection fraction, PER, and PFR were determined for each frame duration. By observing changes in the measured values of these quantities with framing rate we conclude that: a) for the measurement of EF, 50 msec per frame at rest and 40 msec per frame at exercise is sufficient; b) PER requires 40 msec per frame at rest and 20 msec per frame during exercise; and c) for the measurement of PFR, at least 40 msec per frame at rest and 20 msec per frame during exercise are needed. These results should hold for both first-pass and gated equilibrium studies.

  6. An evaluation of multiple-schedule variations to reduce high-rate requests in the picture exchange communication system.

    Science.gov (United States)

    Landa, Robin; Hanley, Gregory P

    2016-06-01

    Using procedures similar to those of Tiger, Hanley, and Heal (2006), we compared two multiple-schedule variations (S+/S- and S+ only) to treat high-rate requests for edible items in the Picture Exchange Communication System (PECS). Two individuals with autism participated, after they showed persistent requests for edible items after PECS training. Stimulus control was achieved only with the multiple schedule that involved presentation of a discriminative stimulus during reinforcement components and its removal during extinction components (S+ only). Discriminated requests were maintained for the 1 participant who experienced schedule thinning. © 2016 Society for the Experimental Analysis of Behavior.

  7. Effect of communication channels on success rate of entrepreneurial SMEs in the agricultural sector (a case study

    Directory of Open Access Journals (Sweden)

    Z. Khoshnodifar

    2016-01-01

    Full Text Available The present research aimed at investigating the effect of communication channels on the economic success of early profitable and entrepreneur small and medium enterprises in the agricultural sector. It was an applied research in which the descriptive-survey method was used. The research sample included 356 founders of entrepreneur small and medium enterprises (at the time of conducting the research in the Markazi province, Iran, among which 100 founders were selected according to the Cochran formulation using the stratified random sampling method. A questionnaire was used as the research tool and its validity was confirmed as the face validity by a group of teachers and experts. The questionnaire’s reliability was calculated using Cronbach’s alpha (α = 0.82. The results indicated that the information seeking facilities of most of the entrepreneurs were seen at a good level (53 persons, 53% and acquiring information from other businesses and consulting contacts with the neighbors and relatives, product sellers and promoting factors were listed as the highest priorities of the respondents, respectively. Also, there was a meaningful relationship between rate of using information and communication resources with the variables namely age, duration of operation on the job, number of people operating the business and number using loans. The results of regression analysis indicated that seven communication channels, promoters, other producers, product sellers, group visit, training films, creditors, radio and TV in the order of significance have defined 78.4% of the dependent variable changes.

  8. Low-Noise Free-Running High-Rate Photon-Counting for Space Communication and Ranging

    Science.gov (United States)

    Lu, Wei; Krainak, Michael A.; Yang, Guan; Sun, Xiaoli; Merritt, Scott

    2016-01-01

    We present performance data for low-noise free-running high-rate photon counting method for space optical communication and ranging. NASA GSFC is testing the performance of two types of novel photon-counting detectors 1) a 2x8 mercury cadmium telluride (HgCdTe) avalanche array made by DRS Inc., and a 2) a commercial 2880-element silicon avalanche photodiode (APD) array. We successfully measured real-time communication performance using both the 2 detected-photon threshold and logic AND-gate coincidence methods. Use of these methods allows mitigation of dark count, after-pulsing and background noise effects without using other method of Time Gating The HgCdTe APD array routinely demonstrated very high photon detection efficiencies (50) at near infrared wavelength. The commercial silicon APD array exhibited a fast output with rise times of 300 ps and pulse widths of 600 ps. On-chip individually filtered signals from the entire array were multiplexed onto a single fast output. NASA GSFC has tested both detectors for their potential application for space communications and ranging. We developed and compare their performances using both the 2 detected photon threshold and coincidence methods.

  9. Inflatable Antennas Support Emergency Communication

    Science.gov (United States)

    2010-01-01

    Glenn Research Center awarded Small Business Innovation Research (SBIR) contracts to ManTech SRS Technologies, of Newport Beach, California, to develop thin film inflatable antennas for space communication. With additional funding, SRS modified the concepts for ground-based inflatable antennas. GATR (Ground Antenna Transmit and Receive) Technologies, of Huntsville, Alabama, licensed the technology and refined it to become the world s first inflatable antenna certified by the Federal Communications Commission. Capable of providing Internet access, voice over Internet protocol, e-mail, video teleconferencing, broadcast television, and other high-bandwidth communications, the systems have provided communication during the wildfires in California, after Hurricane Katrina in Mississippi, and following the 2010 Haiti earthquake.

  10. Optoelectronics research for communication programs at the Goddard Space Flight Center

    Science.gov (United States)

    Krainak, Michael A.

    1991-01-01

    Current optoelectronics research and development of high-power, high-bandwidth laser transmitters, high-bandwidth, high-sensitivity optical receivers, pointing, acquisition and tracking components, and experimental and theoretical system modeling at the NASA Goddard Space Flight Center is reviewed. Program hardware and space flight milestones are presented. It is believed that these experiments will pave the way for intersatellite optical communications links for both the NASA Advanced Tracking and Data Relay Satellite System and commercial users in the 21st century.

  11. VisIO: enabling interactive visualization of ultra-scale, time-series data via high-bandwidth distributed I/O systems

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Christopher J [Los Alamos National Laboratory; Ahrens, James P [Los Alamos National Laboratory; Wang, Jun [UCF

    2010-10-15

    Petascale simulations compute at resolutions ranging into billions of cells and write terabytes of data for visualization and analysis. Interactive visuaUzation of this time series is a desired step before starting a new run. The I/O subsystem and associated network often are a significant impediment to interactive visualization of time-varying data; as they are not configured or provisioned to provide necessary I/O read rates. In this paper, we propose a new I/O library for visualization applications: VisIO. Visualization applications commonly use N-to-N reads within their parallel enabled readers which provides an incentive for a shared-nothing approach to I/O, similar to other data-intensive approaches such as Hadoop. However, unlike other data-intensive applications, visualization requires: (1) interactive performance for large data volumes, (2) compatibility with MPI and POSIX file system semantics for compatibility with existing infrastructure, and (3) use of existing file formats and their stipulated data partitioning rules. VisIO, provides a mechanism for using a non-POSIX distributed file system to provide linear scaling of 110 bandwidth. In addition, we introduce a novel scheduling algorithm that helps to co-locate visualization processes on nodes with the requested data. Testing using VisIO integrated into Para View was conducted using the Hadoop Distributed File System (HDFS) on TACC's Longhorn cluster. A representative dataset, VPIC, across 128 nodes showed a 64.4% read performance improvement compared to the provided Lustre installation. Also tested, was a dataset representing a global ocean salinity simulation that showed a 51.4% improvement in read performance over Lustre when using our VisIO system. VisIO, provides powerful high-performance I/O services to visualization applications, allowing for interactive performance with ultra-scale, time-series data.

  12. Least Reliable Bits Coding (LRBC) for high data rate satellite communications

    Science.gov (United States)

    Vanderaar, Mark; Wagner, Paul; Budinger, James

    1992-02-01

    An analysis and discussion of a bandwidth efficient multi-level/multi-stage block coded modulation technique called Least Reliable Bits Coding (LRBC) is presented. LRBC uses simple multi-level component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Further, soft-decision multi-stage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Using analytical expressions and tight performance bounds it is shown that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of Binary Phase Shift Keying (BPSK). Bit error rates (BER) vs. channel bit energy with Additive White Gaussian Noise (AWGN) are given for a set of LRB Reed-Solomon (RS) encoded 8PSK modulation formats with an ensemble rate of 8/9. All formats exhibit a spectral efficiency of 2.67 = (log2(8))(8/9) information bps/Hz. Bit by bit coded and uncoded error probabilities with soft-decision information are determined. These are traded with with code rate to determine parameters that achieve good performance. The relative simplicity of Galois field algebra vs. the Viterbi algorithm and the availability of high speed commercial Very Large Scale Integration (VLSI) for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

  13. Re-entry communication through a plasma sheath using standing wave detection and adaptive data rate control

    Science.gov (United States)

    Xie, Kai; Yang, Min; Bai, Bowen; Li, Xiaoping; Zhou, Hui; Guo, Lixin

    2016-01-01

    Radio blackout during the re-entry has puzzled the aerospace industry for decades and has not yet been completely resolved. To achieve a continuous data link in the spacecraft's re-entry period, a simple and practicable communication method is proposed on the basis that (1) the electromagnetic-wave backscatter of the plasma sheath affects the voltage standing wave ratio (VSWR) of the antenna, and the backscatter is negatively correlated to transmission components, and (2) the transmission attenuation caused by the plasma sheath reduces the channel capacity. We detect the voltage standing wave ratio changes of the antenna and then adjust the information rate to accommodate the varying channel capacity, thus guaranteeing continuous transmission (for fewer critical data). The experiment was carried out in a plasma generator with an 18-cm-thick and 30-cm-diameter hollow propagation path, and the adaptive communication was implemented using spread spectrum frequency, shift key modulation with a variable spreading factor. The experimental results indicate that, when the over-threshold of VSWR was detected, the bit rate reduced to 250 bps from 4 Mbps automatically and the tolerated plasma density increased by an order of magnitude, which validates the proposed scheme. The proposed method has little additional cost, and the adaptive control does not require a feedback channel. The method is therefore applicable to data transmission in a single direction, such as that of a one-way telemetry system.

  14. Error rates in forensic DNA analysis: Definition, numbers, impact and communication

    NARCIS (Netherlands)

    Kloosterman, A.; Sjerps, M.; Quak, A.

    2014-01-01

    Forensic DNA casework is currently regarded as one of the most important types of forensic evidence, and important decisions in intelligence and justice are based on it. However, errors occasionally occur and may have very serious consequences. In other domains, error rates have been defined and pub

  15. Rate-constrained source separation for speech enhancement in wireless-communicated binaural hearing aids

    Science.gov (United States)

    Ayllón, David; Gil-Pita, Roberto; Rosa-Zurera, Manuel

    2013-12-01

    A recent trend in hearing aids is the connection of the left and right devices to collaborate between them. Binaural systems can provide natural binaural hearing and support the improvement of speech intelligibility in noise, but they require data transmission between both devices, which increases the power consumption. This paper presents a novel sound source separation algorithm for binaural speech enhancement based on supervised machine learning and time-frequency masking. The system is designed considering the power restrictions in hearing aids, constraining both the computational cost of the algorithm and the transmission bit rate. The transmission schema is optimized using a tailored evolutionary algorithm that assigns a different number of bits to each frequency band. The proposed algorithm requires less than 10% of the available computational resources for signal processing and obtains good separation performance using bit rates lower than 64 kbps.

  16. Brief Communication: Correlation of global earthquake rates with temperature and sunspot cycle

    Science.gov (United States)

    Rajesh, R.; Tiwari, R. K.

    2014-04-01

    We studied the complex and non-stationary records of global earthquake employing the robust statistical and spectral techniques to understand the patterns, processes and periodicity. Singular Spectral Analysis (SSA) and correlation methods are used to quantify the nature of principle dynamical processes of global annual earthquake rates. The SSA decomposes the principle component of earthquake rates (first mode), which suggests that there is a linear increase in the yearly earthquake number from 1975 to 2005 accounting for 93% variance and may be identified with the earth's internal dynamical processes. Superimposed on this monotonic trend, there is an 11 years cyclic variation (second and third modes) accounting for 5% variance, which may corresponds to the well-known solar cycle. The remaining 2% higher order fluctuating components appears to be associated with artificial recharge and natural triggering forces (reservoir, tidal triggering etc.). The correlation study indicates that there is strong positive and negative correlation among the global earthquake rates with surface air temperature and sunspot numbers respectively. Interesting coupling mechanisms do exist, in which atmospheric circulations perturbed by the abrupt temperature variability might change the torques/momentum of inertia (earth's angular momentum) of the earth and thereby may offer the required inputs to trigger earthquake activities at the "critical phases".

  17. E-bra with nanosensors, smart electronics and smart phone communication network for heart rate monitoring

    Science.gov (United States)

    Varadan, Vijay K.; Kumar, Prashanth S.; Oh, Sechang; Mathur, Gyanesh N.; Rai, Pratyush; Kegley, Lauren

    2011-04-01

    Heart related ailments have been a major cause for deaths in both men and women in United States. Since 1985, more women than men have died due to cardiac or cardiovascular ailments for reasons that are not well understood as yet. Lack of a deterministic understanding of this phenomenon makes continuous real time monitoring of cardiovascular health the best approach for both early detection of pathophysiological changes and events indicative of chronic cardiovascular diseases in women. This approach requires sensor systems to be seamlessly mounted on day to day clothing for women. With this application in focus, this paper describes a e-bra platform for sensors towards heart rate monitoring. The sensors, nanomaterial or textile based dry electrodes, capture the heart activity signals in form Electrocardiograph (ECG) and relay it to a compact textile mountable amplifier-wireless transmitter module for relay to a smart phone. The ECG signal, acquired on the smart phone, can be transmitted to the cyber space for post processing. As an example, the paper discusses the heart rate estimation and heart rate variability. The data flow from sensor to smart phone to server (cyber infrastructure) has been discussed. The cyber infrastructure based signal post processing offers an opportunity for automated emergency response that can be initiated from the server or the smartphone itself. Detailed protocols for both the scenarios have been presented and their relevance to the present emergency healthcare response system has been discussed.

  18. Brief Communication: Correlation of global earthquake rates with temperature and sunspot cycle

    Directory of Open Access Journals (Sweden)

    R. Rajesh

    2014-04-01

    Full Text Available We studied the complex and non-stationary records of global earthquake employing the robust statistical and spectral techniques to understand the patterns, processes and periodicity. Singular Spectral Analysis (SSA and correlation methods are used to quantify the nature of principle dynamical processes of global annual earthquake rates. The SSA decomposes the principle component of earthquake rates (first mode, which suggests that there is a linear increase in the yearly earthquake number from 1975 to 2005 accounting for 93% variance and may be identified with the earth's internal dynamical processes. Superimposed on this monotonic trend, there is an 11 years cyclic variation (second and third modes accounting for 5% variance, which may corresponds to the well-known solar cycle. The remaining 2% higher order fluctuating components appears to be associated with artificial recharge and natural triggering forces (reservoir, tidal triggering etc.. The correlation study indicates that there is strong positive and negative correlation among the global earthquake rates with surface air temperature and sunspot numbers respectively. Interesting coupling mechanisms do exist, in which atmospheric circulations perturbed by the abrupt temperature variability might change the torques/momentum of inertia (earth's angular momentum of the earth and thereby may offer the required inputs to trigger earthquake activities at the "critical phases".

  19. Visible light communication: Applications, architecture, standardization and research challenges

    Directory of Open Access Journals (Sweden)

    Latif Ullah Khan

    2017-05-01

    Full Text Available The Radio Frequency (RF communication suffers from interference and high latency issues. Along with this, RF communication requires a separate setup for transmission and reception of RF waves. Overcoming the above limitations, Visible Light Communication (VLC is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs which further motivates the usage of VLC. This paper presents a survey of the potential applications, architecture, modulation techniques, standardization and research challenges in VLC.

  20. Bit error rate analysis of X-ray communication system%X射线通信系统的误码率分析∗

    Institute of Scientific and Technical Information of China (English)

    王律强; 苏桐; 赵宝升; 盛立志; 刘永安; 刘舵

    2015-01-01

    X-ray communication, which was firstly introduced by Keithe Gendreau in 2007, is potential to compete with conventional communication methods, such as microwave and laser communication, against space surroundings. As a result, a great deal of time and effort has been devoted to making the initial idea into reality in recent years. Eventually, the X-ray communication demonstration system based on the grid-controlled X-ray source and microchannel plate detector can deliver both audio and video information in a 6-meter vacuum tunnel. The point is how to evaluate this space X-ray demonstration system in a typical experimental way. The method is to design a specific board to measure the relationship between bit-error-rate and emitting power against various communicating distances. In addition, the data should be compared with the calculation and simulation results to estimate the referred theoretical model. The concept of using X-ray as signal carriers is confirmed by our first generation X-ray communication demonstration system. Specifically, the method is to use grid-controlled emission source as a transceiver while implementing the photon counting detector which can be regarded as an important orientation of future deep-space X-ray communication applications. As the key specification of any given communication system, bit-error-rate level should be informed first. In addition, the theoretical analysis by using Poisson noise model also has been implemented to support this novel communication concept. Previous experimental results indicated that the X-ray audio demonstration system requires a 10−4 bit-error-rate level with 25 kbps communication rate. The system bit-error-rate based on on-off keying (OOK) modulation is calculated and measured, which corresponds to the theoretical calculation commendably. Another point that should be taken into consideration is the emitting energy, which is the main restriction of current X-ray communication system. The designed

  1. Fast Faraday Cup With High Bandwidth

    Science.gov (United States)

    Deibele, Craig E [Knoxville, TN

    2006-03-14

    A circuit card stripline Fast Faraday cup quantitatively measures the picosecond time structure of a charged particle beam. The stripline configuration maintains signal integrity, and stitching of the stripline increases the bandwidth. A calibration procedure ensures the measurement of the absolute charge and time structure of the charged particle beam.

  2. Performance limits of high-rate space-to-ground optical communications through the turbulent atmospheric channel

    Science.gov (United States)

    Kaufmann, John E.

    1995-04-01

    Atmospheric turbulence corrupts both the amplitude and phase of an optical field propagating from space to an earth-based receiver. While aperture averaging can mitigate amplitude scintillation effects, the performance of single spatial-mode receiver systems such as coherent detection or preamplified direction detection can be significantly degraded by the corrupted phase when the ratio of aperture diameter D to atmospheric coherence length r0 exceeds unity. Although adaptive optics may be employed to correct the wavefront, in practice the correction is imperfect and the residual phase errors induce a communications performance loss. That loss is quantified here by Monte Carlo simulation techniques. Single-mode-receiver fade statistics for imperfect phase correction are calculated in terms of the atmospheric Greenwood frequency fg, the adaptive optic servo loop cutoff frequency fc, and the ratio D/r0. From these statistics, link bit-error rate (BER) performance is calculated. The results reveal that conventional performance measures such as Strehl ratio or mean signal-to- noise ratio loss can significantly underestimate receiver BER losses. Only when the ratio fg/fc is 0.1 or less will communications losses be small (about 0.5 dB) over a wide range of D/r0.

  3. Full-Duplex Airborne Ultrasonic Data Communication Using a Pilot-Aided QAM-OFDM Modulation Scheme.

    Science.gov (United States)

    Jiang, Wentao; Wright, William M D

    2016-08-01

    Orthogonal frequency division multiplexing (OFDM) has been extensively used in a variety of broadband digital wireless communications applications because of its high bandwidth utilization efficiency and effective immunity to multipath distortion. This paper has investigated quadrature amplitude modulation and OFDM methods in air-coupled ultrasonic communication, using broadband capacitive ultrasonic transducers with high- k dielectric layers. OFDM phase noise was discussed and corrected using a pilot-aided estimation algorithm. The overall system data rate achieved was up to 400 kb/s with a spectral efficiency of 2 b/s/Hz. An ultrasonic propagation model for signal prediction considered atmospheric absorption of sound in air, beam divergence, and transducer frequency response. The simulations were compared with the experimental results, and good agreement was found between the two. Two-way communication through air was also implemented successfully by applying three-way handshaking initialization and an adaptive modulation scheme with variable data rates depending on the transmission distance, estimated using received signal strength indication measurement. It was shown that the error-free transmission range could be extended up to 2.5 m using different system transfer rates from 400 kb/s down to 100 kb/s. In full-duplex transmission mode, the overall error-free system data rate achieved was 0.8 Mb/s up to 1.5 m.

  4. Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET

    OpenAIRE

    Murat Kuscu; Alper Kiraz; Akan, Ozgur B.

    2015-01-01

    Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET Murat Kuscu1, Alper Kiraz2 & Ozgur B. Akan1 1Next-generation andWireless Communications Laboratory (NWCL), Department of Electrical and Electronics Engineering, Koc University, Istanbul, 34450, Turkey, 2Optofluidics and Nano-Optics Research Laboratory, Department of Physics, Koc University, Istanbul, 34450, Turke...

  5. The Law of the Tendency of the Rate of Profit to Fall and the End User Communication Technology

    Directory of Open Access Journals (Sweden)

    Peter Sekloča

    2015-03-01

    Full Text Available The author critically analyses the contemporary debate about the law of the tendential fall in the rate of profit in which Marx summed up the central contradiction of the capitalist mode of production. The results of the analysis are then applied on the business strategies of the informational capitalism in the segment of end users of the informational and communicational technology. Unpaid labor of users for digital media platform owners as well as hardware and software purchase both resemble peculiar counteracting tendencies for the “law”. The analysis indicates that the immaterial labor and outsourcing of equipment may truly increase the profit rate in a way that was rather inconceivable in Marx's day, but this still does not undermine the “law’s” validity. Counteracting tendencies have their own limits and that is also why the capital does not allow them to reach their end and restore conditions for a “new” central contradiction conceptualized by Italian autonomists.

  6. Systems and Methods for Radar Data Communication

    Science.gov (United States)

    Bunch, Brian (Inventor); Szeto, Roland (Inventor); Miller, Brad (Inventor)

    2013-01-01

    A radar information processing system is operable to process high bandwidth radar information received from a radar system into low bandwidth radar information that may be communicated to a low bandwidth connection coupled to an electronic flight bag (EFB). An exemplary embodiment receives radar information from a radar system, the radar information communicated from the radar system at a first bandwidth; processes the received radar information into processed radar information, the processed radar information configured for communication over a connection operable at a second bandwidth, the second bandwidth lower than the first bandwidth; and communicates the radar information from a radar system, the radar information communicated from the radar system at a first bandwidth.

  7. Race, income, and education: associations with patient and family ratings of end-of-life care and communication provided by physicians-in-training.

    Science.gov (United States)

    Long, Ann C; Engelberg, Ruth A; Downey, Lois; Kross, Erin K; Reinke, Lynn F; Cecere Feemster, Laura; Dotolo, Danae; Ford, Dee W; Back, Anthony L; Curtis, J Randall

    2014-04-01

    Minority race and lower socioeconomic status are associated with poorer patient ratings of health care quality and provider communication. To examine the association of race/ethnicity or socioeconomic status with patients' and families' ratings of end-of-life care and communication about end-of-life care provided by physicians-in-training. As a component of a randomized trial evaluating a program designed to improve clinician communication about end-of-life care, patients and patients' families completed preintervention survey data regarding care and communication provided by internal medicine residents and medical subspecialty fellows. We examined associations between patient and family race or socioeconomic status and ratings they gave trainees on two questionnaires: the Quality of End-of-Life Care (QEOLC) and Quality of Communication (QOC). Patients from racial/ethnic minority groups, patients with lower income, and patients with lower educational attainment gave trainees higher ratings on the end-of-life care subscale of the QOC (QOCeol). In path models, patient educational attainment and income had a direct effect on outcomes, while race/ethnicity did not. Lower family educational attainment was also associated with higher trainee ratings on the QOCeol, while family non-white race was associated with lower trainee ratings on the QEOLC and general subscale of the QOC. Patient race is associated with perceptions of the quality of communication about end-of-life care provided by physicians-in-training, but the association was opposite to our hypothesis and appears to be mediated by socioeconomic status. Family member predictors of these perceptions differ from those observed for patients. Further investigation of these associations may guide interventions to improve care delivered to patients and families.

  8. Optical communications and a comparison of optical technologies for a high data rate return link from Mars

    Science.gov (United States)

    Spence, Rodney L.

    1993-01-01

    The important principles of direct- and heterodyne-detection optical free-space communications are reviewed. Signal-to-noise-ratio (SNR) and bit-error-rate (BER) expressions are derived for both the direct-detection and heterodyne-detection optical receivers. For the heterodyne system, performance degradation resulting from received-signal and local oscillator-beam misalignment and laser phase noise is analyzed. Determination of interfering background power from local and extended background sources is discussed. The BER performance of direct- and heterodyne-detection optical links in the presence of Rayleigh-distributed random pointing and tracking errors is described. Finally, several optical systems employing Nd:YAG, GaAs, and CO2 laser sources are evaluated and compared to assess their feasibility in providing high-data-rate (10- to 1000-Mbps) Mars-to-Earth communications. It is shown that the root mean square (rms) pointing and tracking accuracy is a critical factor in defining the system transmitting laser-power requirements and telescope size and that, for a given rms error, there is an optimum telescope aperture size that minimizes the required power. The results of the analysis conducted indicate that, barring the achievement of extremely small rms pointing and tracking errors (less than 0.2 microrad), the two most promising types of optical systems are those that use an Nd:YAG laser (lambda = 1.064 microns) and high-order pulse position modulator (PPM) and direct detection, and those that use a CO2 laser (lambda = 10.6 microns) and phase shifting keying homodyne modulation and coherent detection. For example, for a PPM order of M = 64 and an rms pointing accuracy of 0.4 microrad, an Nd:YAG system can be used to implement a 100-Mbps Mars link with a 40-cm transmitting telescope, a 20-W laser, and a 10-m receiving photon bucket. Under the same conditions, a CO2 system would require 3-m transmitting and receiving telescopes and a 32-W laser to implement such

  9. 未来高带宽网络中FAST TCP与TCP Vegas的公平性分析%Fairness analysis of FAST TCP and TCP Vegas over future high-bandwidth internet

    Institute of Scientific and Technical Information of China (English)

    朱小松

    2012-01-01

    FAST TCP, a modern end-to-end protocol adopting queuing delay as a congestion measure. However, the lack of a precise measurement of queuing delay leads to a potential unfairness problem that FAST TCP flows may be discriminated against according to their starting times in a persistent congestion scenario, TCP Vegas also encounters the unfairness problem. The unfairness problem is quantitatively assessed by mathematical analysis and ns2 simulations, then, we compared FAST TCP with TCP Vegas. Consequently, FAST TCP demonstrates a competitive edge over TCP Vegas, under future high bandwidth-delay product environment. This conclusion will contribute to the improvement of FAST TCP for future reference.%FAST TCP是先进的端到端拥塞控制协议,采用队列时延作为拥塞度量.由于不能准确测得精确的队列时延,此协议中存有不公平的隐患,即在某些持续拥塞场景下,不同时刻启动的FAST TCP流会受到差别对待,TCP Vegas中同样存在不公平问题.通过数学分析和ns2仿真对这种不公平问题进行量化,进而比较FASTTCP与TCP Vegas在公平性问题上的性能差异.结果证明了在将来高带宽时延乘积网络环境下,FAST TCP在公平性上要明显优于TCP Vegas.这为对FAST TCP协议的改进给出了有价值的参照.

  10. A comparison of medical students' written expressions of emotion and coping and standardized patients' ratings of student professionalism and communication skills.

    Science.gov (United States)

    Shapiro, Johanna; Lie, Desiree

    2004-12-01

    Little is known about the relationship between medical students' expression of emotion when confronted with a traumatic medical event and their perceived communication skills and professionalism. Eighty-nine second year medical students participated in an objective structured clinical examination (OSCE) that included a writing exercise. Standardized patients assessed student performance on communication and professionalism. Student writing samples were analysed for emotional language and coping strategies. Two kinds of written language, high positive and distancing, were related to "active" and "detached" coping methods. Standardized patients rated students who used highly positive emotional language as having poorer professionalism and communication skills. Students who endorsed "accepting" coping were perceived as more professional. Future research should investigate whether certain emotional expressions in medical students' writings are related to less patient-centered coping, poorer communication skills, and less professionalism.

  11. Packet error rate analysis of digital pulse interval modulation in intersatellite optical communication systems with diversified wavefront deformation.

    Science.gov (United States)

    Zhu, Jin; Wang, Dayan; Xie, Wanqing

    2015-02-20

    Diversified wavefront deformation is an inevitable phenomenon in intersatellite optical communication systems, which will decrease system performance. In this paper, we investigate the description of wavefront deformation and its influence on the packet error rate (PER) of digital pulse interval modulation (DPIM). With the wavelet method, the diversified wavefront deformation can be described by wavelet parameters: coefficient, dilation, and shift factors, where the coefficient factor represents the depth, dilation factor represents the area, and shift factor is for location. Based on this, the relationship between PER and wavelet parameters is analyzed from a theoretical viewpoint. Numerical results illustrate the validity of theoretical analysis: PER increases with the depth and area and decreases if location gets farther from the center of the optical antenna. In addition to describing diversified deformation, the advantage of the wavelet method over Zernike polynomials in computational complexity is shown via numerical example. This work provides a feasible method for the description along with influence analysis of diversified wavefront deformation from a practical viewpoint and will be helpful for designing optical systems.

  12. Mobile free-space optical communications: a feasibility study of various battlefield scenarios

    Science.gov (United States)

    Harris, Alan; Al-Akkoumi, Mouhammad K.; Sluss, James J., Jr.

    2012-06-01

    Free Space Optics (FSO) technology was originally envisioned to be a viable solution for the provision of high bandwidth optical connectivity in the last mile of today's telecommunications infrastructure. Due to atmospheric limitations inherent to FSO technology, FSO is now widely envisioned as a solution for the provision of high bandwidth, temporary mobile communications links. The need for FSO communications links will increase as mobility is introduced to this technology. In this paper, a theoretical solution for adding mobility to FSO communication links is introduced. Three-dimensional power estimation studies are presented to represent mobile FSO transmission under various weather conditions. Three wavelengths, 0.85, 1.55 and 10 um, are tested and compared to illustrate the pros and cons of each source wavelength used for transmission, depending on prevalent weather conditions and atmospheric turbulence conditions. A simulation analysis of the transmission properties of the source wavelengths used in the study is shown.

  13. On-chip Optical Communication Using

    Directory of Open Access Journals (Sweden)

    Graphene M.Sankar

    2015-05-01

    Full Text Available Advancement in technology is increasing day by day. Accordance to Moore‟s Law, the number of transistors per square inch on integrated circuits had doubled every year. In this way, Graphene research so far has focused on electronics and photonic applications, in spite of its impressive optical properties, graphene can be used as optical communication devices which are more efficient than any other materials. It has as unique photonic and electronic extraordinary properties. This leads to remarkable high bandwidth, zero source-drain bias, better modulation of light, and good internal quantum efficiency.

  14. Has ECB communication been helpful in predicting interest rate decisions? An evaluation of the early years of the Economic and Monetary Union

    NARCIS (Netherlands)

    Jansen, D.J.; de Haan, J.

    2009-01-01

    We examine the usefulness of communication by the European Central Bank for predicting its policy decisions during the early years of the European Economic and Monetary Union. Using ordered probit models based on the Taylor rule, we find that statements on the main refinancing rate and future inflat

  15. Public Hygiene Campaign in Denmark during the 2009 H1N1 Pandemic Had No Effect on Hospitalization Rate of Communicable Diseases in Children

    OpenAIRE

    Nadja Hawwa Vissing; Astrid Sevelsted; Hans Bisgaard

    2013-01-01

    BACKGROUND: During the 2009 H1N1 pandemic the Danish National board of Health carried out massive public hygiene campaigns to limit spread of disease. We aimed to investigate whether this resulted in lower incidences of communicable diseases in the paediatric population. METHODS: The study compared annual hospitalization rates for childhood infections from 2005 to 2011. RESULTS: Admission rates for infections were higher during the year of the pandemic compared to the rest of the period. CONC...

  16. Data communications

    Energy Technology Data Exchange (ETDEWEB)

    Preckshot, G.G. [Lawrence Livermore National Lab., CA (United States)

    1993-08-01

    The purpose of this paper is to recommend regulatory guidance for reviewers examining computer communication systems used in nuclear power plants. The recommendations cover three areas important to these communications systems: system design, communication protocols, and communication media. The first area, system design, considers three aspects of system design--questions about architecture, specific risky design elements or omissions to look for in designs being reviewed, and recommendations for multiplexed data communication systems used in safety systems. The second area reviews pertinent aspects of communication protocol design and makes recommendations for newly designed protocols or the selection of existing protocols for safety system, information display, and non-safety control system use. The third area covers communication media selection, which differs significantly from traditional wire and cable. The recommendations for communication media extend or enhance the concerns of published IEEE standards about three subjects: data rate, imported hazards and maintainability.

  17. The relation between the specific absorption rate and electromagnetic field intensity for heterogeneous exposure conditions at mobile communications frequencies.

    Science.gov (United States)

    Neubauer, Georg; Preiner, Patrick; Cecil, Stefan; Mitrevski, Niki; Gonter, Johannes; Garn, Heinrich

    2009-12-01

    The relation between the incident electromagnetic field strength and both the whole-body and the local specific absorption rate (SAR) was investigated for typical heterogeneous exposure scenarios for frequencies relevant for mobile communication. The results were compared to results from plane wave exposure. Heterogeneous exposure arises from multiple path propagation of the electromagnetic waves to the location of interest. It is shown that plane wave exposure does not represent worst-case exposure conditions. When the electric field strength arising at plane wave exposure is compared to the electric field strength averaged over the volume of the human body occurring during multipath exposure, 12% of all heterogeneous cases examined represent worse exposure conditions than plane wave exposure for whole-body exposure at 946 MHz, 15% at 1840 MHz, and 22% at 2140 MHz. The deviation between plane wave and heterogeneous whole-body SAR ranges from -54% to 54%. For partial-body SAR averaged over 10 g of tissue, a range from -93% to 209% was found when comparing multiple wave exposure to single incoming plane waves. The investigations performed using the Visible Human as phantom showed that the basic restrictions are met as long as the reference levels are not exceeded. However, this must not be necessarily the case when different phantoms are used to perform similar investigations because recent studies demonstrated that reference levels might not be conservative when phantoms of children are used. Therefore, the results of this work indicate the need to extend the investigations to numerical simulations with additional human phantoms representing parts of the human population having different anatomy and morphology compared to the phantom used within the frame of this project. This also applies to phantoms of children.

  18. Initial Characterization of Optical Communications with Disruption-Tolerant Network Protocols

    Science.gov (United States)

    Schoolcraft, Joshua; Wilson, Keith

    2011-01-01

    Disruption-tolerant networks (DTNs) are groups of network assets connected with a suite of communication protocol technologies designed to mitigate the effects of link delay and disruption. Application of DTN protocols to diverse groups of network resources in multiple sub-networks results in an overlay network-of-networks with autonomous data routing capability. In space environments where delay or disruption is expected, performance of this type of architecture (such as an interplanetary internet) can increase with the inclusion of new communications mediums and techniques. Space-based optical communication links are therefore an excellent building block of space DTN architectures. When compared to traditional radio frequency (RF) communications, optical systems can provide extremely power-efficient and high bandwidth links bridging sub-networks. Because optical links are more susceptible to link disruption and experience the same light-speed delays as RF, optical-enabled DTN architectures can lessen potential drawbacks and maintain the benefits of autonomous optical communications over deep space distances. These environment-driven expectations - link delay and interruption, along with asymmetric data rates - are the purpose of the proof-of-concept experiment outlined herein. In recognizing the potential of these two technologies, we report an initial experiment and characterization of the performance of a DTN-enabled space optical link. The experiment design employs a point-to-point free-space optical link configured to have asymmetric bandwidth. This link connects two networked systems running a DTN protocol implementation designed and written at JPL for use on spacecraft, and further configured for higher bandwidth performance. Comparing baseline data transmission metrics with and without periodic optical link interruptions, the experiment confirmed the DTN protocols' ability to handle real-world unexpected link outages while maintaining capability of

  19. Development and pilot testing the Family Conference Rating Scale: A tool aimed to assess interprofessional patient-centred communication and collaboration competencies.

    Science.gov (United States)

    Dojeiji, Sue; Byszewski, Anna; Wood, Tim

    2015-01-01

    There is a paucity of evidence-based literature on the essential communication and collaboration skills to guide health care teams in conducting and assessing their performance in the Family Conference (FC). The authors developed and collected validity evidence for a rating scale of team FC performance, the Family Conference Rating Scale (FCRS). In phase 1, essential FC communication and collaboration skills were identified through a review of existing communication tools and literature on team functioning; a draft 34-item scale was developed. In phase 2, the scale was narrowed to a 6-category, 9-point scale with descriptors of expected behaviours through an iterative process: testing of the scale on 10 FC transcripts by two experts, soliciting feedback from a focus group of seven health care providers, and testing by non-experts on 49 live FCs. In phase 3, scores on the revised scale were validated by 10 health care providers from different disciplines by rating three videos of FCs of variable quality. Raters were able to detect inter-video variation in FC quality. The reliability of the FCRS was 0.95 and the inter-rater reliability, 0.68. The FCRS may enhance the ability of health professions educators to teach and assess interprofessional patient-centred communication and collaboration competencies.

  20. Optical Communication for Coping the UAS Data Deluge

    Science.gov (United States)

    Griethe, Wolfgang; Heine, Frank; Seel, Stefan; Alberty, Thomas

    2012-08-01

    Hardly any technology has retained a greater recovery in recent years than that of the Unmanned Aerial Systems (UAS). The rationale for this is manifold. UAS are currently operated by many countries around the world. Upcoming sensors and raised numbers of operated vehicles create an increased bandwidth demand for Unmanned Aerial Vehicle (UA V) to ground communication bandwidth in the near future, exceeding currently installed RF communication capabilities. A high bandwidth optical link between an above-the-weather UAV and a GEO spacecraft offers a secure, jamming resistant, non-ITU regulated alternative to existing and envisaged Ku- and Ka- band UAV data and TM/TC links.

  1. The use of a rating instrument to teach and assess communication skills of health-care workers in a clinic in the Western Cape.

    Science.gov (United States)

    Steyn, M; Borcherds, R; van der Merwe, N

    1999-06-01

    Research in health communication shows communication to be an important aspect of successful health-care. Moreover, training courses which provide feedback have been shown to improve health professionals' ability to conduct successful interviews. This article describes a rating instrument which was developed in order to facilitate teaching and assessing the communication aspects of health-care interviews. The instrument was found to be useful in a training programme offered to nursing staff of a TB Clinic in Mitchells Plain, Western Cape. The instrument appears as Table 1. In the Table categories of communication behaviours, each indicating an important aspect of the interaction, are given as the six headings. These are: establishing rapport and respect listening receptively confirming the patient sharing control informing effectively and checking perceptions. Within each category the more detailed specific behaviours are listed, allowing for close analysis of a care-giver's interviewing skill. The article briefly discusses the importance in effective communication between the care-giver and patient of each category of behaviours given in the instrument, supported by evidence from research. Lastly the article describes a "case study" on how the instrument has been successfully used in a training programme.

  2. Analytical bit error rate performance evaluation of an orthogonal frequency division multiplexing power line communication system impaired by impulsive and Gaussian channel noise

    OpenAIRE

    Munshi Mahbubur Rahman; Satya Prasad Majumder

    2015-01-01

    An analytical approach is presented to evaluate the bit error rate (BER) performance of a power line (PL) communication system considering the combined influence of impulsive noise and background PL Gaussian noise. Middleton class-A noise model is considered to evaluate the effect of impulsive noise. The analysis is carried out to find the expression of the signal-to-noise ratio and BER considering orthogonal frequency division multiplexing (OFDM) with binary phase shift keying modulation wit...

  3. An experimental evaluation of patient decision aid design to communicate the effects of medications on the rate of progression of structural joint damage in rheumatoid arthritis.

    Science.gov (United States)

    Martin, Richard W; Brower, Matthew E; Geralds, Alexander; Gallagher, Patience J; Tellinghuisen, Donald J

    2012-03-01

    To explore how effectively information presentation formats used in a patient decision aid communicated the ability of a disease modifying anti-rheumatic drug to slow the rate of progression of rheumatoid arthritis related structural joint damage (SJD). 91 first year psychology students and 91 RA patients participated in a prospective randomized, single blind, factorial experimental design evaluating the effect of four information formats on: satisfaction with risk communication, verbatim and gist recall of a hypothetical anti-rheumatic drug's ability to slow the rate of progression of SJD. Both groups underestimated the hypothetical drug's ability to slow SJD. Formats that supported the narrative statement with a reinforcing graphic element resulted in recall closer to the true value. Comparison of the results from testing of RA patients and college students were remarkably similar across formats. Rate of progression as communicated by narrative statement plus a graphic element (i.e. speedometer metaphor or pictograph) aided recall better than a narrative statement alone. Our results suggest that testing decision aid components with non-patients may provide data generalizable to patient populations. Graphics must be used carefully in patient decision aids as they can enhance recall, but may also introduce unintended recall bias. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Public hygiene campaign in denmark during the 2009 H1N1 pandemic had no effect on hospitalization rate of communicable diseases in children.

    Science.gov (United States)

    Vissing, Nadja Hawwa; Sevelsted, Astrid; Bisgaard, Hans

    2013-01-01

    During the 2009 H1N1 pandemic the Danish National board of Health carried out massive public hygiene campaigns to limit spread of disease. We aimed to investigate whether this resulted in lower incidences of communicable diseases in the paediatric population. The study compared annual hospitalization rates for childhood infections from 2005 to 2011. Admission rates for infections were higher during the year of the pandemic compared to the rest of the period. There were no indications of a preventive effect by the hygiene campaign on incidence of severe common childhood infections.

  5. Public hygiene campaign in denmark during the 2009 H1N1 pandemic had no effect on hospitalization rate of communicable diseases in children.

    Directory of Open Access Journals (Sweden)

    Nadja Hawwa Vissing

    Full Text Available BACKGROUND: During the 2009 H1N1 pandemic the Danish National board of Health carried out massive public hygiene campaigns to limit spread of disease. We aimed to investigate whether this resulted in lower incidences of communicable diseases in the paediatric population. METHODS: The study compared annual hospitalization rates for childhood infections from 2005 to 2011. RESULTS: Admission rates for infections were higher during the year of the pandemic compared to the rest of the period. CONCLUSION: There were no indications of a preventive effect by the hygiene campaign on incidence of severe common childhood infections.

  6. In the eye of the beholder: perceived, actual, and peer-rated similarity in personality, communication, and friendship intensity during the acquaintanceship process.

    Science.gov (United States)

    Selfhout, Maarten; Denissen, Jaap; Branje, Susan; Meeus, Wim

    2009-06-01

    The authors examined associations of perceived similarity, actual similarity, and peer-rated similarity in personality with friendship intensity during the acquaintanceship process in a naturalistic setting. Self- and peer-rated personality data were gathered from undergraduates (mean age = 18.9) at 5 time points during the first year of university using a round-robin design. Whereas perceived similarity and peer-rated similarity in personality were concurrently associated with more friendship intensity for just-acquainted individuals, actual similarity in personality was not. Further, bidirectional cross-lagged associations between perceived similarity and friendship intensity were found. Peer-rated similarity was also associated with increases in friendship intensity, and this association was mediated by communication frequency. These results indicate that specific types of similarity in personality are differentially associated with friendship intensity during early phases of acquaintanceship in a real-life setting. Further, insight was provided in the direction of causality between similarity and attraction: Perceived and peer-rated similarity seem to breed friendship intensity, whereas friendship intensity seems to breed perceived similarity only. Finally, peers' expectations seem to affect individuals' communicative behaviors, which in turn affect friendship formation.

  7. Free-space optical communication links and evaporation layer study near sea surface at 1.55 μm

    Science.gov (United States)

    Zeller, John; Manzur, Tariq

    2011-06-01

    In many situations where it is necessary to set up a communication link such as emergencies or in remote locations, running fiber between two sites is not practical. Free-space optics (FSO) holds the potential for high bandwidth communication in such situations with relatively low cost, low maintenance, quick installation times, and average 70- 80% connectivity. Since atmospheric conditions can significantly affect the capability of this type of communication system to transfer information consistently and operate effectively, the effects of atmosphere on FSO communication and consequent optimal wavelength range for transmission are investigated through MODTRAN-based modeling of 1.55 μm transmission. Simulations were performed for multiple elevation angles in atmospheric weather conditions including clear maritime, desert extinction, and various levels of rain and fog to simulate surface-to-surface and surfaceto- air FSO communication networks. Atmospheric, free-space, and scintillation losses are analyzed for optical path lengths of up to 2 km or greater to determine minimum transmit power required for successful data reception. In addition, the effects of atmospheric turbulence on beam propagation in the evaporation layer are investigated, where wavefront sensing with adaptive optics as well as a software Kalman filter are seen as a means to compensate for wavefront distortion. Using advanced laser sources to provide illumination at infrared wavelengths, particularly around the eye-safe 1.55 μm wavelength, it should be possible to overcome many transmission limitations associated with atmospheric conditions such as adverse weather and turbulence to enable high data rate communication links where the use of fiber is not practical or prohibited.

  8. INVESTIGATION ON HYBRID WDM (DWDM+CWDM FREE SPACE OPTICAL COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    S. Robinson

    2015-12-01

    Full Text Available Free Space Optical (FSO communication is being realized as an effective solution for future accessing networks, offering light passed through air. The performance of FSO can be primarily degraded by various atmospheric attenuation namely, rain, fog, haze and snow. At present, hybridization of Dense Wavelength Division Multiplexing (DWDM with Coarse Wavelength Division Multiplexing (CWDM becomes necessary to scale the speed and high bandwidth of the services. In this paper, hybrid WDM system is proposed, designed and the network parameters such as Bit Error Rate (BER, Quality Factor and receiver sensitivity are analyzed with respect to link distance for various weather conditions. For investigation, 4 CWDM and 8 DWDM channels are considered whose corresponding channel spacing is 20nm and 0.8nm, respectively. From the simulation, it is investigated that the average link distance of proposed hybrid WDM-FSO system for DWDM and CWDM system at very clear condition are around 810km and 780km. The proposed hybrid WDM based FSO system is designed to handle the quality of transmission for 12 users, each at a data rate of 2.5Gbps.

  9. Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET

    Science.gov (United States)

    Kuscu, Murat; Kiraz, Alper; Akan, Ozgur B.

    2015-01-01

    Nanocommunications via Förster Resonance Energy Transfer (FRET) is a promising means of realising collaboration between photoactive nanomachines to implement advanced nanotechnology applications. The method is based on exchange of energy levels between fluorescent molecules by the FRET phenomenon which intrinsically provides a virtual nanocommunication link. In this work, further to the extensive theoretical studies, we demonstrate the first information transfer through a FRET-based nanocommunication channel. We implement a digital communication system combining macroscale transceiver instruments and a bulk solution of fluorophore nanoantennas. The performance of the FRET-based Multiple-Input and Multiple-Output (MIMO) nanocommunication channel between closely located mobile nanoantennas in the sample solution is evaluated in terms of Signal-to-Noise Ratio (SNR) and Bit Error Rate (BER) obtained for the transmission rates of 50 kbps, 150 kbps and 250 kbps. The results of the performance evaluation are very promising for the development of high-rate and reliable molecular communication networks at nanoscale.

  10. Performance improvement of OFDM-FSO multi-user communication system with combined transmit frequency diversity and receive space diversity

    Science.gov (United States)

    Kumar, Pravindra; Srivastava, Anand

    2016-05-01

    Orthogonal frequency division multiplexed (OFDM) based free space optical (FSO) communication link gives improved performance because of narrow-band interference, improved robustness against fading and high bandwidth efficiency. It is further improved using transmit frequency diversity and space diversity at the receiver. In this paper, we propose to use OFDM architecture combined with spreading code in electrical domain, referred as code division multiplexed-orthogonal frequency division multiplexing (CDM-OFDM) which provides frequency diversity at the transmitter and using more than one receiver to get receive diversity. Analytical model of CDM-OFDM-FSO communication system with photo-detector space diversity using maximal ratio combining (MRC) is analyzed in the presence of turbulent atmosphere, multi-user-interference (MUI) and timing jitter. The error performance is computed in terms of receiver sensitivity and bit-error-rate (BER). In the analysis, Gamma-Gamma distribution is considered for atmospheric turbulence. The performance of OFDM-FSO link and CDM-OFDM-FSO link is compared. It is seen that for multiple users, CDM-OFDM-FSO link with transmit and receive diversity gives improved performance as compared to OFDM-FSO link.

  11. On the Optimality of Repetition Coding among Rate-1 DC-offset STBCs for MIMO Optical Wireless Communications

    KAUST Repository

    Sapenov, Yerzhan

    2017-07-06

    In this paper, an optical wireless multiple-input multiple-output communication system employing intensity-modulation direct-detection is considered. The performance of direct current offset space-time block codes (DC-STBC) is studied in terms of pairwise error probability (PEP). It is shown that among the class of DC-STBCs, the worst case PEP corresponding to the minimum distance between two codewords is minimized by repetition coding (RC), under both electrical and optical individual power constraints. It follows that among all DC-STBCs, RC is optimal in terms of worst-case PEP for static channels and also for varying channels under any turbulence statistics. This result agrees with previously published numerical results showing the superiority of RC in such systems. It also agrees with previously published analytic results on this topic under log-normal turbulence and further extends it to arbitrary turbulence statistics. This shows the redundancy of the time-dimension of the DC-STBC in this system. This result is further extended to sum power constraints with static and turbulent channels, where it is also shown that the time dimension is redundant, and the optimal DC-STBC has a spatial beamforming structure. Numerical results are provided to demonstrate the difference in performance for systems with different numbers of receiving apertures and different throughput.

  12. High-Efficiency K-Band Space Traveling-Wave Tube Amplifier for Near-Earth High Data Rate Communications

    Science.gov (United States)

    Simons, Rainee N.; Force, Dale A.; Spitsen, Paul C.; Menninger, William L.; Robbins, Neal R.; Dibb, Daniel R.; Todd, Phillip C.

    2010-01-01

    The RF performance of a new K-Band helix conduction cooled traveling-wave tube amplifier (TWTA), is presented in this paper. A total of three such units were manufactured, tested and delivered. The first unit is currently flying onboard NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft and has flawlessly completed over 2000 orbits around the Moon. The second unit is a proto-flight model. The third unit will fly onboard NASA's International Space Station (ISS) as a very compact and lightweight transmitter package for the Communications, Navigation and Networking Reconfigurable Testbed (CoNNeCT), which is scheduled for launch in 2011. These TWTAs were characterized over the frequencies 25.5 to 25.8 GHz. The saturated RF output power is greater than 40 W and the saturated RF gain is greater than 46 dB. The saturated AM-to-PM conversion is 3.5 /dB and the small signal gain ripple is 0.46 dB peak-to-peak. The overall efficiency of the TWTA, including that of the electronic power conditioner (EPC) is as high as 45%.

  13. FPGA-based rate-adaptive LDPC-coded modulation for the next generation of optical communication systems.

    Science.gov (United States)

    Zou, Ding; Djordjevic, Ivan B

    2016-09-05

    In this paper, we propose a rate-adaptive FEC scheme based on LDPC codes together with its software reconfigurable unified FPGA architecture. By FPGA emulation, we demonstrate that the proposed class of rate-adaptive LDPC codes based on shortening with an overhead from 25% to 42.9% provides a coding gain ranging from 13.08 dB to 14.28 dB at a post-FEC BER of 10-15 for BPSK transmission. In addition, the proposed rate-adaptive LDPC coding combined with higher-order modulations have been demonstrated including QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM, which covers a wide range of signal-to-noise ratios. Furthermore, we apply the unequal error protection by employing different LDPC codes on different bits in 16-QAM and 64-QAM, which results in additional 0.5dB gain compared to conventional LDPC coded modulation with the same code rate of corresponding LDPC code.

  14. A Conflict-Free Low-Jitter Guaranteed-Rate MAC Protocol for Base-Station Communications in Wireless Mesh Networks

    Science.gov (United States)

    Szymanski, T. H.

    A scheduling algorithm and MAC protocol which provides low-jitter guaranteed-rate (GR) communications between base-stations (BS) in a Wireless Mesh Network (WMN) is proposed. The protocol can provision long-term multimedia services such as VOIP, IPTV, or Video-on-Demand. The time-axis is partitioned into scheduling frames with F time-slots each. A directional antennae scheme is used to provide each directed link with a fixed transmission rate. A protocol such as IntServ is used to provision resources along an end-to-end path of BSs for GR sessions. The Guaranteed Rates between the BSs are then specified in a doubly stochastic traffic rate matrix, which is recursively decomposed to yield a low-jitter GR frame transmission schedule. In the resulting schedule, the end-to-end delay and jitter are small and bounded, and the cell loss rate due to primary scheduling conflicts is zero. For dual-channel WMNs, the MAC protocol can achieve 100% utilization, as well as near-minimal queueing delays and near minimal delay jitter. The scheduling time complexity is O(NFlogNF), where N is the number of BSs. Extensive simulation results are presented.

  15. Short communication: Effects of dairy calf hutch elevation on heat reduction, carbon dioxide concentration, air circulation, and respiratory rates.

    Science.gov (United States)

    Moore, D A; Duprau, J L; Wenz, J R

    2012-07-01

    Heat stress affects dairy calf welfare and can result in morbidity, mortality, and lower weight gain. The purpose of this project was to evaluate the effects of elevating the back of plastic calf hutches on measures of ventilation and heat stress. A total of 15 calves housed in individual hutches were enrolled, with each calf hutch serving as its own control. Heat, humidity, carbon dioxide, and wind speed were measured inside each hutch and the observations were compared with external measurements over two 24-h periods; 1 period without and 1 with hutch elevation. Respiratory rates were measured in the morning and afternoon as an indicator of the degree of heat stress experienced by calves with and without elevation of the hutch. When the hutch was elevated, internal hutch temperatures were cooler than external temperatures, hutch carbon dioxide levels were lower and respiratory rates were lower, particularly comparing the afternoon observation periods.

  16. Communication: Transition state trajectory stability determines barrier crossing rates in chemical reactions induced by time-dependent oscillating fields.

    Science.gov (United States)

    Craven, Galen T; Bartsch, Thomas; Hernandez, Rigoberto

    2014-07-28

    When a chemical reaction is driven by an external field, the transition state that the system must pass through as it changes from reactant to product--for example, an energy barrier--becomes time-dependent. We show that for periodic forcing the rate of barrier crossing can be determined through stability analysis of the non-autonomous transition state. Specifically, strong agreement is observed between the difference in the Floquet exponents describing stability of the transition state trajectory, which defines a recrossing-free dividing surface [G. T. Craven, T. Bartsch, and R. Hernandez, "Persistence of transition state structure in chemical reactions driven by fields oscillating in time," Phys. Rev. E 89, 040801(R) (2014)], and the rates calculated by simulation of ensembles of trajectories. This result opens the possibility to extract rates directly from the intrinsic stability of the transition state, even when it is time-dependent, without requiring a numerically expensive simulation of the long-time dynamics of a large ensemble of trajectories.

  17. Rate Maximization in MIMO Decode-and-Forward Communications With an EH Relay and Possibly Imperfect CSI

    KAUST Repository

    Benkhelifa, Fatma

    2016-08-29

    In this paper, we investigate the simultaneous wireless information and power transfer (SWIPT) in a multiple-input multiple-output (MIMO) decode-and-forward (DF) relay system where the relay is an energy harvesting (EH) multi-antenna node equipped with an EH receiver and an information decoding (ID) receiver. The relay harvests the energy from the radio frequency (RF) signals sent by the source and uses it to forward the signals to the destination. The main objective in this paper is to maximize the achievable transmission rate of the overall link by optimizing the source/relay precoders. First, we study an upper bound on the maximum achievable rate where we assume that the EH and ID receivers operate simultaneously and have access to the whole power of the received signals. Afterwards, we study two practical schemes, which are the power splitting (PS) and time switching (TS) schemes, where the ID and EH receivers have partial access to the power or duration of the received signals. For each scheme, we have studied the complexity and the performance comparison. In addition, we considered the case of the imperfect channel estimation error and we have observed its impact on the achievable end-to-end rate and the harvested energy at the relay. © 1972-2012 IEEE.

  18. Evaluation and Verification of Channel Transmission Characteristics of Human Body for Optimizing Data Transmission Rate in Electrostatic-Coupling Intra Body Communication System: A Comparative Analysis.

    Directory of Open Access Journals (Sweden)

    Yuhwai Tseng

    Full Text Available Intra-body communication is a new wireless scheme for transmitting signals through the human body. Understanding the transmission characteristics of the human body is therefore becoming increasingly important. Electrostatic-coupling intra-body communication system in a ground-free situation that integrate electronic products that are discretely located on individuals, such as mobile phones, PDAs, wearable computers, and biomedical sensors, are of particular interest.The human body is modeled as a simplified Resistor-Capacitor network. A virtual ground between the transmitter and receiver in the system is represented by a resister-capacitor network. Value of its resistance and capacitance are determined from a system perspective. The system is characterized by using a mathematical unit step function in digital baseband transmission scheme with and without Manchester code. As a result, the signal-to-noise and to-intersymbol-interference ratios are improved by manipulating the load resistor. The data transmission rate of the system is optimized. A battery-powered transmitter and receiver are developed to validate the proposal.A ground-free system fade signal energy especially for a low-frequency signal limited system transmission rate. The system transmission rate is maximized by simply manipulating the load resistor. Experimental results demonstrate that for a load resistance of 10k-50k Ω, the high-pass 3 dB frequency of the band-pass channel is 400kHz-2MHz in the worst-case scenario. The system allows a Manchester-coded baseband signal to be transmitted at speeds of up to 20M bit per second with signal-to-noise and signal-to-intersymbol-interference ratio of more than 10 dB.The human body can function as a high speed transmission medium with a data transmission rate of 20Mbps in an electrostatic-coupling intra-body communication system. Therefore, a wideband signal can be transmitted directly through the human body with a good signal

  19. Bit error rate analysis of free-space optical communication over general Malaga turbulence channels with pointing error

    KAUST Repository

    Alheadary, Wael G.

    2016-12-24

    In this work, we present a bit error rate (BER) and achievable spectral efficiency (ASE) performance of a freespace optical (FSO) link with pointing errors based on intensity modulation/direct detection (IM/DD) and heterodyne detection over general Malaga turbulence channel. More specifically, we present exact closed-form expressions for adaptive and non-adaptive transmission. The closed form expressions are presented in terms of generalized power series of the Meijer\\'s G-function. Moreover, asymptotic closed form expressions are provided to validate our work. In addition, all the presented analytical results are illustrated using a selected set of numerical results.

  20. Information and communication technology demands at work: the association with job strain, effort-reward imbalance and self-rated health in different socio-economic strata.

    Science.gov (United States)

    Stadin, Magdalena; Nordin, Maria; Broström, Anders; Magnusson Hanson, Linda L; Westerlund, Hugo; Fransson, Eleonor I

    2016-10-01

    The use of information and communication technology (ICT) is common in modern working life. ICT demands may give rise to experience of work-related stress. Knowledge about ICT demands in relation to other types of work-related stress and to self-rated health is limited. Consequently, the aim of this study was to examine the association between ICT demands and two types of work-related stress [job strain and effort-reward imbalance (ERI)] and to evaluate the association between these work-related stress measures and self-rated health, in general and in different SES strata. This study is based on cross-sectional data from the Swedish Longitudinal Occupational Survey of Health collected in 2014, from 14,873 gainfully employed people. ICT demands, job strain, ERI and self-rated health were analysed as the main measures. Sex, age, SES, lifestyle factors and BMI were used as covariates. ICT demands correlated significantly with the dimensions of the job strain and ERI models, especially with the demands (r = 0.42; p < 0.01) and effort (r = 0.51; p < 0.01) dimensions. ICT demands were associated with suboptimal self-rated health, also after adjustment for age, sex, SES, lifestyle and BMI (OR 1.49 [95 % CI 1.36-1.63]), but job strain (OR 1.93 [95 % CI 1.74-2.14) and ERI (OR 2.15 [95 % CI 1.95-2.35]) showed somewhat stronger associations with suboptimal self-rated health. ICT demands are common among people with intermediate and high SES and associated with job strain, ERI and suboptimal self-rated health. ICT demands should thus be acknowledged as a potential stressor of work-related stress in modern working life.

  1. Integrated Performance of Next Generation High Data Rate Receiver and AR4JA LDPC Codec for Space Communications

    Science.gov (United States)

    Cheng, Michael K.; Lyubarev, Mark; Nakashima, Michael A.; Andrews, Kenneth S.; Lee, Dennis

    2008-01-01

    Low-density parity-check (LDPC) codes are the state-of-the-art in forward error correction (FEC) technology that exhibits capacity approaching performance. The Jet Propulsion Laboratory (JPL) has designed a family of LDPC codes that are similar in structure and therefore, leads to a single decoder implementation. The Accumulate-Repeat-by-4-Jagged- Accumulate (AR4JA) code design offers a family of codes with rates 1/2, 2/3, 4/5 and lengths 1024, 4096, 16384 information bits. Performance is less than one dB from capacity for all combinations.Integrating a stand-alone LDPC decoder with a commercial-off-the-shelf (COTS) receiver faces additional challenges than building a single receiver-decoder unit from scratch. In this work, we outline the issues and show that these additional challenges can be over-come by simple solutions. To demonstrate that an LDPC decoder can be made to work seamlessly with a COTS receiver, we interface an AR4JA LDPC decoder developed on a field-programmable gate array (FPGA) with a modern high data rate receiver and mea- sure the combined receiver-decoder performance. Through optimizations that include an improved frame synchronizer and different soft-symbol scaling algorithms, we show that a combined implementation loss of less than one dB is possible and therefore, most of the coding gain evidence in theory can also be obtained in practice. Our techniques can benefit any modem that utilizes an advanced FEC code.

  2. High Data Rates for AubieSat-2 A & B, Two CubeSats Performing High Energy Science in the Upper Atmosphere

    Science.gov (United States)

    Sims, William H.

    2015-01-01

    This paper will discuss a proposed CubeSat size (3 Units / 6 Units) telemetry system concept being developed at Marshall Space Flight Center (MSFC) in cooperation with Auburn University. The telemetry system incorporates efficient, high-bandwidth communications by developing flight-ready, low-cost, PROTOFLIGHT software defined radio (SDR) payload for use on CubeSats. The current telemetry system is slightly larger in dimension of footprint than required to fit within a 0.75 Unit CubeSat volume. Extensible and modular communications for CubeSat technologies will provide high data rates for science experiments performed by two CubeSats flying in formation in Low Earth Orbit. The project is a collaboration between the University of Alabama in Huntsville and Auburn University to study high energy phenomena in the upper atmosphere. Higher bandwidth capacity will enable high-volume, low error-rate data transfer to and from the CubeSats, while also providing additional bandwidth and error correction margin to accommodate more complex encryption algorithms and higher user volume.

  3. The emancipated energy customer - new possibilities for communication and in designing energy rate systems; Der muendige Energiekunde - neue Moeglichkeiten der Kommunikation und Tarifmodellgestaltung

    Energy Technology Data Exchange (ETDEWEB)

    Thiemann, R.; Passenberg, I.; Suer, S. [IBM Global Business Services, Duesseldorf (Germany)

    2008-01-15

    Whoever wants to attract new and bind existing customers must be familiar with their life habits, behaviours and needs. This rule applies for energy providers just much as it does for other types of enterprise. A study by the business consultancy IBM Global Business Services has illuminated consumers' everyday use of and perspectives on energy. It transpires that customer behaviour is characterised by contradictions. Whereas on one side price and environmental issues play a significant role, on the other so does their personal comfort. The results of the study show that these conflicting priorities open up new possibilities for energy providers to communicate with their customers and design their energy rate systems.

  4. Obtaining a W state from a Greenberger-Horne-Zeilinger state via stochastic local operations and classical communication with a rate approaching unity.

    Science.gov (United States)

    Yu, Nengkun; Guo, Cheng; Duan, Runyao

    2014-04-25

    We introduce a notion of the entanglement transformation rate to characterize the asymptotic comparability of two multipartite pure entangled states under stochastic local operations and classical communication (SLOCC). For two well known SLOCC inequivalent three-qubit states |GHZ⟩=(1/2)(|000⟩+|111⟩) and |W⟩=(1/3)(|100⟩+|010⟩+|001⟩), we show that the entanglement transformation rate from |GHZ⟩ to |W⟩ is exactly 1. That means that we can obtain one copy of the W state from one copy of the Greenberg-Horne-Zeilinger (GHZ) state by SLOCC, asymptotically. We then apply similar techniques to obtain a lower bound on the entanglement transformation rates from an N-partite GHZ state to a class of Dicke states, and prove the tightness of this bound for some special cases which naturally generalize the |W⟩ state. A new lower bound on the tensor rank of the matrix permanent is also obtained by evaluating the tensor rank of Dicke states.

  5. Obtaining a W State from a Greenberger-Horne-Zeilinger State via Stochastic Local Operations and Classical Communication with a Rate Approaching Unity

    Science.gov (United States)

    Yu, Nengkun; Guo, Cheng; Duan, Runyao

    2014-04-01

    We introduce a notion of the entanglement transformation rate to characterize the asymptotic comparability of two multipartite pure entangled states under stochastic local operations and classical communication (SLOCC). For two well known SLOCC inequivalent three-qubit states |GHZ⟩=(1/√2 )(|000⟩+|111⟩) and |W⟩=(1/√3 )(|100⟩+|010⟩+|001⟩), we show that the entanglement transformation rate from |GHZ⟩ to |W⟩ is exactly 1. That means that we can obtain one copy of the W state from one copy of the Greenberg-Horne-Zeilinger (GHZ) state by SLOCC, asymptotically. We then apply similar techniques to obtain a lower bound on the entanglement transformation rates from an N-partite GHZ state to a class of Dicke states, and prove the tightness of this bound for some special cases which naturally generalize the |W⟩ state. A new lower bound on the tensor rank of the matrix permanent is also obtained by evaluating the tensor rank of Dicke states.

  6. A Simplified Mobile Ad Hoc Network Structure for Helicopter Communication

    Directory of Open Access Journals (Sweden)

    Abdeldime Mohamed Salih Abdelgader

    2016-01-01

    Full Text Available There are a number of volunteer and statutory organizations who are capable of conducting an emergency response using helicopters. Rescue operations require a rapidly deployable high bandwidth network to coordinate necessary relief efforts between rescue teams on the ground and helicopters. Due to massive destruction and loss of services, ordinary communication infrastructures may collapse in these situations. Consequently, information exchange becomes one of the major challenges in these circumstances. Helicopters can be also employed for providing many services in rugged environments, military applications, and aerial photography. Ad hoc network can be used to provide alternative communication link between a set of helicopters, particularly in case of significant amount of data required to be shared. This paper addresses the ability of using ad hoc networks to support the communication between a set of helicopters. A simplified network structure model is presented and extensively discussed. Furthermore, a streamlined routing algorithm is proposed. Comprehensive simulations are conducted to evaluate the proposed routing algorithm.

  7. Underwater Communications for Video Surveillance Systems at 2.4 GHz

    Directory of Open Access Journals (Sweden)

    Sandra Sendra

    2016-10-01

    Full Text Available Video surveillance is needed to control many activities performed in underwater environments. The use of wired media can be a problem since the material specially designed for underwater environments is very expensive. In order to transmit the images and videos wirelessly under water, three main technologies can be used: acoustic waves, which do not provide high bandwidth, optical signals, although the effect of light dispersion in water severely penalizes the transmitted signals and therefore, despite offering high transfer rates, the maximum distance is very small, and electromagnetic (EM waves, which can provide enough bandwidth for video delivery. In the cases where the distance between transmitter and receiver is short, the use of EM waves would be an interesting option since they provide high enough data transfer rates to transmit videos with high resolution. This paper presents a practical study of the behavior of EM waves at 2.4 GHz in freshwater underwater environments. First, we discuss the minimum requirements of a network to allow video delivery. From these results, we measure the maximum distance between nodes and the round trip time (RTT value depending on several parameters such as data transfer rate, signal modulations, working frequency, and water temperature. The results are statistically analyzed to determine their relation. Finally, the EM waves’ behavior is modeled by a set of equations. The results show that there are some combinations of working frequency, modulation, transfer rate and temperature that offer better results than others. Our work shows that short communication distances with high data transfer rates is feasible.

  8. Underwater Communications for Video Surveillance Systems at 2.4 GHz

    Science.gov (United States)

    Sendra, Sandra; Lloret, Jaime; Jimenez, Jose Miguel; Rodrigues, Joel J.P.C.

    2016-01-01

    Video surveillance is needed to control many activities performed in underwater environments. The use of wired media can be a problem since the material specially designed for underwater environments is very expensive. In order to transmit the images and videos wirelessly under water, three main technologies can be used: acoustic waves, which do not provide high bandwidth, optical signals, although the effect of light dispersion in water severely penalizes the transmitted signals and therefore, despite offering high transfer rates, the maximum distance is very small, and electromagnetic (EM) waves, which can provide enough bandwidth for video delivery. In the cases where the distance between transmitter and receiver is short, the use of EM waves would be an interesting option since they provide high enough data transfer rates to transmit videos with high resolution. This paper presents a practical study of the behavior of EM waves at 2.4 GHz in freshwater underwater environments. First, we discuss the minimum requirements of a network to allow video delivery. From these results, we measure the maximum distance between nodes and the round trip time (RTT) value depending on several parameters such as data transfer rate, signal modulations, working frequency, and water temperature. The results are statistically analyzed to determine their relation. Finally, the EM waves’ behavior is modeled by a set of equations. The results show that there are some combinations of working frequency, modulation, transfer rate and temperature that offer better results than others. Our work shows that short communication distances with high data transfer rates is feasible. PMID:27782095

  9. Advanced communications technology satellite high burst rate link evaluation terminal power control and rain fade software test plan, version 1.0

    Science.gov (United States)

    Reinhart, Richard C.

    1993-01-01

    The Power Control and Rain Fade Software was developed at the NASA Lewis Research Center to support the Advanced Communications Technology Satellite High Burst Rate Link Evaluation Terminal (ACTS HBR-LET). The HBR-LET is an experimenters terminal to communicate with the ACTS for various experiments by government, university, and industry agencies. The Power Control and Rain Fade Software is one segment of the Control and Performance Monitor (C&PM) Software system of the HBR-LET. The Power Control and Rain Fade Software automatically controls the LET uplink power to compensate for signal fades. Besides power augmentation, the C&PM Software system is also responsible for instrument control during HBR-LET experiments, control of the Intermediate Frequency Switch Matrix on board the ACTS to yield a desired path through the spacecraft payload, and data display. The Power Control and Rain Fade Software User's Guide, Version 1.0 outlines the commands and procedures to install and operate the Power Control and Rain Fade Software. The Power Control and Rain Fade Software Maintenance Manual, Version 1.0 is a programmer's guide to the Power Control and Rain Fade Software. This manual details the current implementation of the software from a technical perspective. Included is an overview of the Power Control and Rain Fade Software, computer algorithms, format representations, and computer hardware configuration. The Power Control and Rain Fade Test Plan provides a step-by-step procedure to verify the operation of the software using a predetermined signal fade event. The Test Plan also provides a means to demonstrate the capability of the software.

  10. Design and Performance Evaluation of Contention Resolution Schemes with QoS Support for Multimedia Traffic in High Bit-Rate Wireless Communications

    Science.gov (United States)

    Srichavengsup, Warakorn; Charoenpanichkit, Akkarapat; Wuttisittikulkij, Lunchakorn

    This paper considers the problem of contention resolution algorithm for multi-class with quality of service (QoS) constrained for wireless communication. Five different channel reservation schemes are proposed, namely, UNI+MLA, UNI+DS, UNI+DS+MLA, Partial UNI and Partial UNI+MLA schemes for multimedia traffic, all are extensions of our recently proposed UNI scheme for single-class traffic. The goal is to achieve the highest system performance and enable each traffic type to meet its QoS requirements. We evaluate the performance of each scheme by mathematical analysis. The numerical results show that our proposed schemes are effective in enabling each traffic type to achieve the best successful rate possible in this kind of environment. Finally when comparing between our proposed schemes and conventional technique in terms of both throughput performance and QoS requirements it is found that the UNI+MLA, UNI+DS+MLA and Partial UNI+MLA schemes are relatively efficient and suitable for practical applications.

  11. Analytical bit error rate performance evaluation of an orthogonal frequency division multiplexing power line communication system impaired by impulsive and Gaussian channel noise

    Directory of Open Access Journals (Sweden)

    Munshi Mahbubur Rahman

    2015-02-01

    Full Text Available An analytical approach is presented to evaluate the bit error rate (BER performance of a power line (PL communication system considering the combined influence of impulsive noise and background PL Gaussian noise. Middleton class-A noise model is considered to evaluate the effect of impulsive noise. The analysis is carried out to find the expression of the signal-to-noise ratio and BER considering orthogonal frequency division multiplexing (OFDM with binary phase shift keying modulation with coherent demodulation of OFDM sub-channels. The results are evaluated numerically considering the multipath transfer function model of PL with non-flat power spectral density of PL background noise over a bandwidth of 0.3–100 MHz. The results are plotted for several system and noise parameters and penalty because of impulsive noise is determined at a BER of 10^−6. The computed results show that the system suffers significant power penalty because of impulsive noise which is higher at higher channel bandwidth and can be reduced by increasing the number of OFDM subcarriers to some extent. The analytical results conform well with the simulation results reported earlier.

  12. Deep-space and near-Earth optical communications by coded orbital angular momentum (OAM) modulation.

    Science.gov (United States)

    Djordjevic, Ivan B

    2011-07-18

    In order to achieve multi-gigabit transmission (projected for 2020) for the use in interplanetary communications, the usage of large number of time slots in pulse-position modulation (PPM), typically used in deep-space applications, is needed, which imposes stringent requirements on system design and implementation. As an alternative satisfying high-bandwidth demands of future interplanetary communications, while keeping the system cost and power consumption reasonably low, in this paper, we describe the use of orbital angular momentum (OAM) as an additional degree of freedom. The OAM is associated with azimuthal phase of the complex electric field. Because OAM eigenstates are orthogonal the can be used as basis functions for N-dimensional signaling. The OAM modulation and multiplexing can, therefore, be used, in combination with other degrees of freedom, to solve the high-bandwidth requirements of future deep-space and near-Earth optical communications. The main challenge for OAM deep-space communication represents the link between a spacecraft probe and the Earth station because in the presence of atmospheric turbulence the orthogonality between OAM states is no longer preserved. We will show that in combination with LDPC codes, the OAM-based modulation schemes can operate even under strong atmospheric turbulence regime. In addition, the spectral efficiency of proposed scheme is N2/log2N times better than that of PPM.

  13. High bandwidth on-chip capacitive tuning of microtoroid resonators

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-01-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications.

  14. Effective Actuation: High Bandwidth Actuators and Actuator Scaling Laws

    Science.gov (United States)

    2007-11-02

    piezo elements mounted on structural members and devices that exhibited aeroacoustic resonance. The former type of actuator ( piezo ) was considered...Raman and Kibens (Raman et al. 2000). These experiments involved high-frequency forcing applied to low-speed flows using wedge piezo actuators and... Subharmonic Interaction and Wall Influence," AIAA- 86-1047, May, 1986. Davis, S. A., 2000, "The manipulation of large and small flow structures in single and

  15. Design of application specific high bandwidth Nyquist DAC

    NARCIS (Netherlands)

    Zhijun, Wei

    2008-01-01

    Digital-to-analog (DAC) converters translate digital codes into different physical quantities in voltage, current or charges. They are used either as a stand alone functional block in a big system or as a subsystem in analog-to-digital (ADC) converters. The DAC in this project is a subsystem in a tw

  16. Extremelly High Bandwidth Rad Hard Data Acquisition System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Analog-to-digital converters (ADCs) are the key components for digitizing high-speed analog data in modern data acquisition systems, which is a critical part of...

  17. Extremelly High Bandwidth Rad Hard Data Acquisition System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advancements in sensors/detectors are needed to support future NASA mission concepts including polarimetry, large format imaging arrays, and high-sensitivity...

  18. Using the Sirocco File System for high-bandwidth checkpoints.

    Energy Technology Data Exchange (ETDEWEB)

    Klundt, Ruth Ann; Curry, Matthew L.; Ward, H. Lee

    2012-02-01

    The Sirocco File System, a file system for exascale under active development, is designed to allow the storage software to maximize quality of service through increased flexibility and local decision-making. By allowing the storage system to manage a range of storage targets that have varying speeds and capacities, the system can increase the speed and surety of storage to the application. We instrument CTH to use a group of RAM-based Sirocco storage servers allocated within the job as a high-performance storage tier to accept checkpoints, allowing computation to potentially continue asynchronously of checkpoint migration to slower, more permanent storage. The result is a 10-60x speedup in constructing and moving checkpoint data from the compute nodes. This demonstration of early Sirocco functionality shows a significant benefit for a real I/O workload, checkpointing, in a real application, CTH. By running Sirocco storage servers within a job as RAM-only stores, CTH was able to store checkpoints 10-60x faster than storing to PanFS, allowing the job to continue computing sooner. While this prototype did not include automatic data migration, the checkpoint was available to be pushed or pulled to disk-based storage as needed after the compute nodes continued computing. Future developments include the ability to dynamically spawn Sirocco nodes to absorb checkpoints, expanding this mechanism to other fast tiers of storage like flash memory, and sharing of dynamic Sirocco nodes between multiple jobs as needed.

  19. Adaptive slope compensation for high bandwidth digital current mode controller

    DEFF Research Database (Denmark)

    Taeed, Fazel; Nymand, Morten

    2015-01-01

    An adaptive slope compensation method for digital current mode control of dc-dc converters is proposed in this paper. The compensation slope is used for stabilizing the inner current loop in peak current mode control. In this method, the compensation slope is adapted with the variations...... in converter duty cycle. The adaptive slope compensation provides optimum controller operation in term of bandwidth over wide range of operating points. In this paper operation principle of the controller is discussed. The proposed controller is implemented in an FPGA to control a 100 W buck converter...

  20. 5G Wireless Communication Systems

    Directory of Open Access Journals (Sweden)

    Saddam Hossain

    2013-10-01

    Full Text Available As a subscriber becomes more aware of the mobile phone technology, he/she will seek for anappropriate package all together, including all the advanced features of a cellular phone can have. Hence, the search for new technology is always the main intention of the prime cell phone giants to out innovate their competitors. In addition, the main purpose of the fifth generation wireless networks (5G Wireless networks is planned to design the best wireless world that is free from limitations and hindrance of the previous generations.5G technologies will change the way most high bandwidth users access their Mobile Radio Communication (MRC. So, this paper represents, great evolution of 1G (First Generation to 4G yield 5G, introduction to 5G technologies, why there is a need for 5G, advantages of 5G networks technology, exceptional applications, Quality of Service (QoS, 5G network architecture-The MasterCore as well as hardware and software for the 5GMasterCore technology

  1. A configurable realtime DWT-based neural data compression and communication VLSI system for wireless implants.

    Science.gov (United States)

    Yang, Yuning; Kamboh, Awais M; Mason, Andrew J

    2014-04-30

    This paper presents the design of a complete multi-channel neural recording compression and communication system for wireless implants that addresses the challenging simultaneous requirements for low power, high bandwidth and error-free communication. The compression engine implements discrete wavelet transform (DWT) and run length encoding schemes and offers a practical data compression solution that faithfully preserves neural information. The communication engine encodes data and commands separately into custom-designed packet structures utilizing a protocol capable of error handling. VLSI hardware implementation of these functions, within the design constraints of a 32-channel neural compression implant, is presented. Designed in 0.13μm CMOS, the core of the neural compression and communication chip occupies only 1.21mm(2) and consumes 800μW of power (25μW per channel at 26KS/s) demonstrating an effective solution for intra-cortical neural interfaces.

  2. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    The course presents the fundamental principles for digital communication, e.g. fixed-wire modems or wireless communication channels, as applied in mobile phones, wireless computer networks or wireless systems in intelligent houses. Based on the functional blocks of a digital communication system......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a communication...... system. Having passed the course, the student will be able to accomplish the following, within the areas shown below: Model for Communication System. Prepare and explain the functional block in a digital communication system, corresponding to the specific course contents. Model for Communication Channel...

  3. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    The course presents the fundamental principles for digital communication, e.g. fixed-wire modems or wireless communication channels, as applied in mobile phones, wireless computer networks or wireless systems in intelligent houses. Based on the functional blocks of a digital communication system......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a communication...... system. Having passed the course, the student will be able to accomplish the following, within the areas shown below: Model for Communication System. Prepare and explain the functional block in a digital communication system, corresponding to the specific course contents. Model for Communication Channel...

  4. Demonstration of Communication using Neutrinos

    CERN Document Server

    Stancil, D D; Alania, M; Aliaga, L; Andrews, M; Del Castillo, C Araujo; Bagby, L; Alba, J L Bazo; Bodek, A; Boehnlein, D; Bradford, R; Brooks, W K; Budd, H; Butkevich, A; Caicedo, D A M; Capista, D P; Castromonte, C M; Chamorro, A; Charlton, E; Christy, M E; Chvojka, J; Conrow, P D; Danko, I; Day, M; Devan, J; Downey, J M; Dytman, S A; Eberly, B; Fein, J R; Felix, J; Fields, L; Fiorentini, G A; Gago, A M; Gallagher, H; Gran, R; Grange, J; Griffin, J; Griffin, T; Hahn, E; Harris, D A; Higuera, A; Hobbs, J A; Hoffman, C M; Hughes, B L; Hurtado, K; Judd, A; Kafka, T; Kephart, K; Kilmer, J; Kordosky, M; Kulagin, S A; Kuznetsov, V A; Lanari, M; Le, T; Lee, H; Loiacono, L; Maggi, G; Maher, E; Manly, S; Mann, W A; Marshall, C M; McFarland, K S; Mislivec, A; McGowan, A M; Morfin, J G; da Motta, H; Mousseau, J; Nelson, J K; Niemiec-Gielata, J A; Ochoa, N; Osmanov, B; Osta, J; Palomino, J L; Paradis, J S; Paolone, V; Park, J; Pena, C; Perdue, G; Lara, C E Perez; Peterman, A M; Pla-Dalmau, A; Pollock, B; Prokoshin, F; Ransome, R D; Ray, H; Reyhan, M; Rubinov, P; Ruggiero, D; Sands, O S; Schellman, H; Schmitz, D W; Schulte, E C; Simon, C; Salinas, C J Solano; Stefanski, R; Stevens, R G; Tagg, N; Takhistov, V; Tice, B G; Tilden, R N; Velasquez, J P; Vergalosova, I; Voirin, J; Walding, J; Walker, B J; Walton, T; Wolcott, J; Wytock, T P; Zavala, G; Zhang, D; Zhu, L Y; Ziemer, B P

    2012-01-01

    Beams of neutrinos have been proposed as a vehicle for communications under unusual circumstances, such as direct point-to-point global communication, communication with submarines, secure communications and interstellar communication. We report on the performance of a low-rate communications link established using the NuMI beam line and the MINERvA detector at Fermilab. The link achieved a decoded data rate of 0.1 bits/sec with a bit error rate of 1% over a distance of 1.035 km, including 240 m of earth.

  5. Absolutely covert quantum communication

    CERN Document Server

    Bradler, Kamil; Siopsis, George; Weedbrook, Christian

    2016-01-01

    We present truly ultimate limits on covert quantum communication by exploiting quantum-mechanical properties of the Minkowski vacuum in the quantum field theory framework. Our main results are the following: We show how two parties equipped with Unruh-DeWitt detectors can covertly communicate at large distances without the need of hiding in a thermal background or relying on various technological tricks. We reinstate the information-theoretic security standards for reliability of asymptotic quantum communication and show that the rate of covert communication is strictly positive. Therefore, contrary to the previous conclusions, covert and reliable quantum communication is possible.

  6. Public Hygiene Campaign in Denmark during the 2009 H1N1 Pandemic Had No Effect on Hospitalization Rate of Communicable Diseases in Children

    DEFF Research Database (Denmark)

    Vissing, Nadja Hawwa; Sevelsted, Astrid; Bisgaard, Hans

    2013-01-01

    During the 2009 H1N1 pandemic the Danish National board of Health carried out massive public hygiene campaigns to limit spread of disease. We aimed to investigate whether this resulted in lower incidences of communicable diseases in the paediatric population.......During the 2009 H1N1 pandemic the Danish National board of Health carried out massive public hygiene campaigns to limit spread of disease. We aimed to investigate whether this resulted in lower incidences of communicable diseases in the paediatric population....

  7. Power Consumption Efficiency Evaluation of Multi-User Full-Duplex Visible Light Communication Systems for Smart Home Technologies

    Directory of Open Access Journals (Sweden)

    Muhammad Tabish Niaz

    2017-02-01

    Full Text Available Visible light communication (VLC has recently gained significant academic and industrial attention. VLC has great potential to supplement the functioning of the upcoming radio-frequency (RF-based 5G networks. It is best suited for home, office, and commercial indoor environments as it provides a high bandwidth and high data rate, and the visible light spectrum is free to use. This paper proposes a multi-user full-duplex VLC system using red-green-blue (RGB, and white emitting diodes (LEDs for smart home technologies. It utilizes red, green, and blue LEDs for downlink transmission and a simple phosphor white LED for uplink transmission. The red and green color bands are used for user data and smart devices, respectively, while the blue color band is used with the white LED for uplink transmission. The simulation was carried out to verify the performance of the proposed multi-user full-duplex VLC system. In addition to the performance evaluation, a cost-power consumption analysis was performed by comparing the power consumption and the resulting cost of the proposed VLC system to the power consumed and resulting cost of traditional Wi-Fi based systems and hybrid systems that utilized both VLC and Wi-Fi. Our findings showed that the proposed system improved the data rate and bit-error rate performance, while minimizing the power consumption and the associated costs. These results have demonstrated that a full-duplex VLC system is a feasible solution suitable for indoor environments as it provides greater cost savings and energy efficiency when compared to traditional Wi-Fi-based systems and hybrid systems that utilize both VLC and Wi-Fi.

  8. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  9. Communication technology update and fundamentals

    CERN Document Server

    Grant, August E

    2010-01-01

    New communication technologies are being introduced at an astonishing rate. Making sense of these technologies is increasingly difficult. Communication Technology Update and Fundamentals is the single best source for the latest developments, trends, and issues in communication technology. Featuring the fundamental framework along with the history and background of communication technologies, Communication Technology Update and Fundamentals, 12th edition helps you stay ahead of these ever-changing and emerging technologies.As always, every chapter ha

  10. Differential employment rates in the journalism and mass communication labor force based on gender, race and ethnicity: Exploring the impact of affirmative action

    NARCIS (Netherlands)

    Becker, L.B.; Lauf, E.; Lowrey, W.

    1999-01-01

    This paper examines whether gender, race, and ethnicity are associated with employment in the journalism and mass communication labor market and—if discrepancies in employment exist—what explanations might he offered for them. The data show strong evidence that race and ethnicity are associated with

  11. Providing prenatal care to pregnant women with overweight or obesity: Differences in provider communication and ratings of the patient-provider relationship by patient body weight.

    Science.gov (United States)

    Washington Cole, Katie O; Gudzune, Kimberly A; Bleich, Sara N; Cheskin, Lawrence J; Bennett, Wendy L; Cooper, Lisa A; Roter, Debra L

    2017-06-01

    To examine the association of women's body weight with provider communication during prenatal care. We coded audio recordings of prenatal visits between 22 providers and 117 of their patients using the Roter Interaction Analysis System. Multivariate, multilevel Poisson models were used to examine the relationship between patient pre-pregnancy body mass index and provider communication. Compared to women with normal weight, providers asked fewer lifestyle questions (IRR 0.66, 95% CI 0.44-0.99, p=0.04) and gave less lifestyle information (IRR 0.51, 95% CI 0.32-0.82, p=0.01) to women with overweight and obesity, respectively. Providers used fewer approval (IRR 0.68, 95% CI 0.51-0.91, p=0.01) and concern statements (IRR 0.68, 95% CI 0.53-0.86, p=0.002) when caring for women with overweight and fewer self-disclosure statements caring for women with obesity (IRR 0.40, 95% CI 0.19-0.84 p=0.02). Less lifestyle and rapport building communication for women with obesity may weaken patient-provider relationship during routine prenatal care. Interventions to increase use of patient-centered communication - especially for women with overweight and obesity - may improve prenatal care quality. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Differential Employment Rates in the Journalism and Mass Communication Labor Force Based on Gender, Race, and Ethnicity: Exploring the Impact of Affirmative Action.

    Science.gov (United States)

    Becker, Lee B.; Lauf, Edmund; Lowrey, Wilson

    1999-01-01

    Finds strong evidence that race and ethnicity are associated with lower levels of employment among journalism and mass communication graduates. Notes these discrepancies in success in the job market are explainable by factors normally associated with hiring, such as type of training, type of institution offering the training, or qualifications…

  13. Differential employment rates in the journalism and mass communication labor force based on gender, race and ethnicity: Exploring the impact of affirmative action

    NARCIS (Netherlands)

    Becker, L.B.; Lauf, E.; Lowrey, W.

    1999-01-01

    This paper examines whether gender, race, and ethnicity are associated with employment in the journalism and mass communication labor market and—if discrepancies in employment exist—what explanations might he offered for them. The data show strong evidence that race and ethnicity are associated with

  14. Cooperative wireless communications

    CERN Document Server

    Zhang, Yan

    2009-01-01

    Cooperative devices and mechanisms are increasingly important to enhance the performance of wireless communications and networks, with their ability to decrease power consumption and packet loss rate and increase system capacity, computation, and network resilience. Considering the wide range of applications, strategies, and benefits associated with cooperative wireless communications, researchers and product developers need a succinct understanding of relevant theory, fundamentals, and techniques to navigate this challenging field. ""Cooperative Wireless Communications"" provides just that. I

  15. Postcultural Communication?

    DEFF Research Database (Denmark)

    Jensen, Iben

    2015-01-01

    When we as scholars use the concept of intercultural communication in its classic definition, as communication between people with different cultural backgrounds, we perpetuate the notion that national differences influence communication more than other differences; in doing so, ethnic minorities...

  16. Strategizing Communication

    DEFF Research Database (Denmark)

    Gulbrandsen, Ib Tunby; Just, Sine Nørholm

    not determine the success of strategic communication. Rather, contextual factors such as competition, technological developments, global cultural trends and local traditions as well as employees’ skills and attitudes will determine the organization’s communicative success. This holds true regardless...... and less on the plan to communicate. Against the backdrop of the comprehensive changes to communication in and about organizations brought about by the rise of digital communication technologies and related contextual developments, Strategizing Communication provides better and more up to date tools...

  17. Mission-Critical Mobile Broadband Communications in Open Pit Mines

    DEFF Research Database (Denmark)

    Uzeda Garcia, Luis Guilherme; Portela Lopes de Almeida, Erika; Barbosa, Viviane S. B.

    2016-01-01

    that need to be met by the wireless network. This article introduces fundamental concepts behind open-pit mining and discusses why this ever changing environment coupled with strict industrial reliability requirements pose unique challenges to traditional broadband network planning and optimization......The need for continuous safety improvements and increased operational efficiency is driving the mining industry through a transition towards automated operations. From a communications perspective, this transition introduces a new set of high-bandwidth business- and mission-critical applications...... techniques. On the other hand, unlike unpredictable disaster scenarios, mining is a carefully planned activity. Taking advantage of this predictability element, we propose a framework that integrates mine and network planning so that continuous and automated adaptation of the network becomes possible...

  18. Communications article

    KAUST Repository

    Fariborzi, Hossein

    2017-07-20

    Seamless, covert communications using a communications system integrated or incorporated within an article of clothing is described. In one embodiment, the communications system is integrated or incorporated into a shoe insole and includes a haptic feedback mechanism, a communications module, a flexible pressure sensor, and a battery. The communications module includes a wireless communications module for wireless communications, a wired interface for wired communications, a microcontroller, and a battery charge controller. The flexible pressure sensor can be actuated by an individual\\'s toe, for example, and communication between two communications nodes can be achieved using coded signals sent by individuals using a combination of long and short presses on the pressure sensor. In response to the presses, wireless communications modules can transmit and receive coded signals based on the presses.

  19. Research on Low Rate Turbo Code and Its Applications%极低码率Turbo码及其应用研究

    Institute of Scientific and Technical Information of China (English)

    胡东伟

    2014-01-01

    For the purpose of transmission with very low signal to noise ratios,the structure of the encoder of a low rate turbo code is presented in this paper.The corresponding decoding algorithm is analyzed,and the performance of this coding scheme is obtained by simulations.This paper presents the application method of low rate Turbo code in shortwave communications or meteor burst communica⁃tions systems is proposed in high bandwidth and complex channel environment. Comparisons are conducted between the application of low rate turbo code and the concatenating scheme of high rate turbo code and spectrum spread technique.The study proves that low rate Turbo code has better performance than traditional ones.With low rate turbo code,the application of adaptive modulation and coding technique can be extended to low signal to noise scenarios.%针对极低信噪比条件下的传输,研究了极低码率Turbo码的编译码器结构,仿真分析了其性能。提出了极低码率Turbo码在高带宽容量、复杂信道环境,例如:短波通信、流星余迹通信等系统中的使用方法。比较了极低码率Turbo码与高码率Turbo码加扩频的性能。研究表明,极低码率Turbo码较传统高码率Turbo码有更好的性能,能将自适应调制编码技术向低信噪比环境扩展。

  20. Dependence of the bit error rate on the signal power and length of a single-channel coherent single-span communication line (100 Gbit s-1) with polarisation division multiplexing

    Science.gov (United States)

    Gurkin, N. V.; Konyshev, V. A.; Nanii, O. E.; Novikov, A. G.; Treshchikov, V. N.; Ubaydullaev, R. R.

    2015-01-01

    We have studied experimentally and using numerical simulations and a phenomenological analytical model the dependences of the bit error rate (BER) on the signal power and length of a coherent single-span communication line with transponders employing polarisation division multiplexing and four-level phase modulation (100 Gbit s-1 DP-QPSK format). In comparing the data of the experiment, numerical simulations and theoretical analysis, we have found two optimal powers: the power at which the BER is minimal and the power at which the fade margin in the line is maximal. We have derived and analysed the dependences of the BER on the optical signal power at the fibre line input and the dependence of the admissible input signal power range for implementation of the communication lines with a length from 30 - 50 km up to a maximum length of 250 km.

  1. Participatory Communication

    DEFF Research Database (Denmark)

    Tufte, Thomas

    This user guide on participatory communication aims to answer the following questions: What do we mean when we say participatory communication? What are the practical implications of working with participatory communication strategies in development and social change processes? What practical...... experiences document that participatory communication adds value to a development project or program? Many communication practitioners and development workers face obstacles and challenges in their practical work. A participatory communication strategy offers a very specific perspective on how to articulate......, tools, and experiences on how to implement participatory communications strategies. It is targeted toward government officials, World Bank staff, develompent workers in the field, and civil society....

  2. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    system.   Sessions in class with active participation by the students. The time will be divided between lectures and the students solving problems, including simulating digital communication building blocks in Matlab. Combines lectures and hands-on work. Semester: E2011 Extent: 7.5 ects......The course presents the fundamental principles for digital communication, e.g. fixed-wire modems or wireless communication channels, as applied in mobile phones, wireless computer networks or wireless systems in intelligent houses. Based on the functional blocks of a digital communication system......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a communication...

  3. Are Student Ratings of Communication Instructors Due to "Easy" Grading Practices? An Analysis of Teacher Credibility and Student-Reported Performance Levels.

    Science.gov (United States)

    Beatty, Michael J.; Zahn, Christopher J.

    1990-01-01

    Investigates the empirical relationships between student ratings of teachers and student-reported performance. Finds that students discriminate between sociability and qualification-related aspects of teacher performance and that student ratings were not the product of "easy" grading practices. (SR)

  4. Submarine Communications .

    Directory of Open Access Journals (Sweden)

    H.B. Singh

    1993-01-01

    Full Text Available Submarines operating in deep water are virtually cut off from the outer world. It becomes very important and essential to convey survivable and critical information to the submarine during the time it operates under water. Conventional means of radio communication do not serve any useful purpose as the higher frequencies get attenuated very sharply in sea water. At VLF band, which is presently being used by most of the world Navies, signal can penetrate only upto 8-10 m of depth. This depth is not sufficient under hostile environment. ELF is another band where listening depth is around 100 m but data rate is very low. This paper summarizes the various means of communication used to send messages to submarine while cruising at various depths. It seems that in the near future blue-green laser is going to be the vital means of sending large information to a submarine operating much deeper (500-700 m with unrestricted speed.

  5. CSR communication

    DEFF Research Database (Denmark)

    Golob, Ursa; Podnar, Klement; Elving, Wim

    2013-01-01

    Purpose – This paper aims to introduce the special issue on CSR communication attached to the First International CSR Communication Conference held in Amsterdam in October 2011. The aim of the introduction is also to review CSR communication papers published in scholarly journals in order to make...... a summary of the state of CSR communication knowledge. Design/methodology/approach – The existing literature on CSR communication was approached via systematic review. with a combination of conventional and summative qualitative content analysis. The final dataset contained 90 papers from two main business...... communications. The most important outlets for CSR communication-related topics are Journal of Business Ethics and Corporate Communications: An International Journal. Originality/value – This paper represents the first attempt to perform a systematic and comprehensive overview of CSR communication papers...

  6. Scientific communication

    Directory of Open Access Journals (Sweden)

    Aleksander Kobylarek

    2017-09-01

    Full Text Available The article tackles the problem of models of communication in science. The formal division of communication processes into oral and written does not resolve the problem of attitude. The author defines successful communication as a win-win game, based on the respect and equality of the partners, regardless of their position in the world of science. The core characteristics of the process of scientific communication are indicated , such as openness, fairness, support, and creation. The task of creating the right atmosphere for science communication belongs to moderators, who should not allow privilege and differentiation of position to affect scientific communication processes.

  7. Communication skills.

    Science.gov (United States)

    Ellison, Deborah

    2015-03-01

    The front-line nurse is responsible for providing direct patient care, patient satisfaction, care coordination, policy, safety, and communication during a 12-hour shift. Every nurse has the opportunity to make a positive impact on patient outcomes through day-to-day advocacy for patients, nurses, and the nursing profession. Communication is a means of advocacy that provides the avenue to which a positive impact can be made. There are multiple barriers to effective communication in the day-to-day communication of the front-line nurse. Interprofessional communication and shared governance models offer ways to improve communication within nursing and within a systems approach.

  8. Communication technology update and fundamentals

    CERN Document Server

    Grant, August E

    2008-01-01

    New communication technologies are being introduced at an astonishing rate. Making sense of these technologies is increasingly difficult. Communication Technology Update is the single best source for the latest developments, trends, and issues in communication technology. Now in its 11th edition, Communication Technology Update has become an indispensable information resource for business, government, and academia. As always, every chapter has been completely rewritten to reflect the latest developments and market statistics, and now covers mobile computing, dig

  9. Robust Timing Synchronization for AC-OFDM Based Optical Wireless Communications

    CERN Document Server

    Ranjha, Bilal A; Kavehrad, Mohsen; Deng, Peng

    2015-01-01

    Visible light communications (VLC) have recently attracted a growing interest and can be a potential solution to realize indoor wireless communication with high bandwidth capacity for RF-restricted environments such as airplanes and hospitals. Optical based orthogonal frequency division multiplexing (OFDM) systems have been proposed in the literature to combat multipath distortion and intersymbol interference (ISI) caused by multipath signal propagation. In this paper, we present a robust timing synchronization scheme suitable for asymmetrically clipped (AC) OFDM based optical intensity modulated direct detection (IM/DD) wireless systems. Our proposed method works perfectly for ACO-OFDM, Pulse amplitude modulated discrete multitone (PAM-DMT) and discrete Hartley transform (DHT) based optical OFDM systems. In contrast to existing OFDM timing synchronization methods which are either not suitable for AC OFDM techniques due to unipolar nature of output signal or perform poorly, our proposed method is suitable for...

  10. Communication (action with communicative content).

    Science.gov (United States)

    Russo, M T

    2010-01-01

    The term Communication generally designate the transmission of a message of concepts, feelings or needs from a speaker to a receiver by means of verbal or no verbal language. The pragmatic approach to human communication has put in evidence a further implication of this concept: every behaviour therefore has a value even when it is not intentional. Recently, a more dynamic concept of communication has been elaborated where communication means communicative action. This interpretation is the starting point for the theory of the "communicative acting" and subsequently of the so called discourse ethic elaborated by J. Habermas.

  11. Communicative Writing

    Institute of Scientific and Technical Information of China (English)

    彭燕

    2016-01-01

    Writing, like all other aspects of language , is communicative.Communicative writing takes an important part in English learn-ing.Communicative writing assignments train students to turn personal observations into impersonal prose , avoid value judgments unwelcome in the sciences, and write with economy and precision .In the English language classroom , however, writing often lacks this.Why?There are lots of reasons , as there are lots of ways to make the writing we do with students more communicative .

  12. Participatory Communication

    DEFF Research Database (Denmark)

    Tufte, Thomas

    This user guide on participatory communication aims to answer the following questions: What do we mean when we say participatory communication? What are the practical implications of working with participatory communication strategies in development and social change processes? What practical......, tools, and experiences on how to implement participatory communications strategies. It is targeted toward government officials, World Bank staff, develompent workers in the field, and civil society....

  13. Existential Communication.

    Science.gov (United States)

    Self, Charles C.

    Focusing on the seminal work "Being and Nothingness," this paper explores the implications of the ideas of Jean-Paul Sartre for the study of communication in society. The paper redefines communication from an existential point of view, explores some implications of this redefinition for the study of communication within the social…

  14. Existential Communication.

    Science.gov (United States)

    Self, Charles C.

    Focusing on the seminal work "Being and Nothingness," this paper explores the implications of the ideas of Jean-Paul Sartre for the study of communication in society. The paper redefines communication from an existential point of view, explores some implications of this redefinition for the study of communication within the social setting, and…

  15. Communication Links

    OpenAIRE

    2003-01-01

    This interactive tutorial helps learners to: Identify key upward, lateral, downward, and informal communication links in their organizations. , Reflect on the benefits, control, satisfaction, information filters, and feedback mechanism of various communication links in the organizations. OCL1000 Communicating Change in Complex Organizations

  16. Stereotypes Communication

    Science.gov (United States)

    Zhang, Shuli; Deng, Dongyuan

    2009-01-01

    We live in a world, which is becoming a Global Village in which information and communication attract people's attention more than ever before. Our desire to communicate with strangers and our relationships with them depend on the degree to which we are effective in communicating with them. There are so many factors restricting or improving…

  17. Existential Communication.

    Science.gov (United States)

    Self, Charles C.

    Focusing on the seminal work "Being and Nothingness," this paper explores the implications of the ideas of Jean-Paul Sartre for the study of communication in society. The paper redefines communication from an existential point of view, explores some implications of this redefinition for the study of communication within the social…

  18. Cultural Communications.

    Science.gov (United States)

    Armas, Jose

    It is too often taken for granted that the communication process with culturally different children takes place as readily as it might with children from Anglo cultures. Most teachers receive training in verbal and formal communication skills; children come to school with nonverbal and informal communication skills. This initially can create…

  19. Perinatal Risks in "Late Motherhood" Defined Based On Parity and Preterm Birth Rate - an Analysis of the German Perinatal Survey (20th Communication).

    Science.gov (United States)

    Schure, V; Voigt, M; Schild, R L; Hesse, V; Carstensen, M; Schneider, K T M; Straube, S

    2012-01-01

    Aim: "Late motherhood" is associated with greater perinatal risks but the term lacks precise definition. We present an approach to determine what "late motherhood" associated with "high risk" is, based on parity and preterm birth rate. Materials and Methods: Using data from the German Perinatal Survey of 1998-2000 we analysed preterm birth rates in women with zero, one, or two previous live births. We compared groups of "late" mothers (with high preterm birth rates) with "control" groups of younger women (with relatively low preterm birth rates). Data of 208 342 women were analysed. For women with zero (one; two) previous live births, the "control" group included women aged 22-26 (27-31; 29-33) years. Women in the "late motherhood" group were aged > 33 (> 35; > 38) years. Results: The "late motherhood" groups defined in this way were also at higher risk of adverse perinatal events other than preterm birth. For women with zero (one; two) previous live births, normal cephalic presentation occurred in 89 % (92.7 %; 93.3 %) in the "control" group, but only in 84.5 % (90 %; 90.4 %) in the "late motherhood" group. The mode of delivery was spontaneous or at most requiring manual help in 71.3 % (83.4 %; 85.8 %) in the "control" group, but only in 51.4 % (72.2 %; 76.4 %) in the "late motherhood" group. Five-minute APGAR scores were likewise worse for neonates of "late" mothers and the proportion with a birth weight ≤ 2499 g was greater. Conclusion: "Late motherhood" that is associated with greater perinatal risks can be defined based on parity and preterm birth rate.

  20. Communication Acoustics

    DEFF Research Database (Denmark)

    Blauert, Jens

    Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

  1. Fiber Optic Infrastructure for Wireless Communication Networks

    Science.gov (United States)

    Lau, Kam Y.; Cutrer, David M.; Georges, John B.; Yeung, Simon

    It is clear that to meet the new demands of wireless customers, conventional cellular service providers and upcoming Personal Communication Service (PCS) providers for conventional phone service and high bandwidth wireless LAN must upgrade their networks to provide complete radio coverage. This evolution has motivated the need for low-cost systems that transport radio signals to and from areas of poor signal coverage. The most important area where this problem must be solved is inside of buildings, since this is where people spend most of their time. Unfortunately, the in-building environment is also the most challenging area to provide radio coverage due to severe attenuation and multi-path effects. The problem must be tackled from the viewpoint of optimization of performance/cost ratio of the network. In this paper, we describe a system-level approach to tackle this problem. We demonstrate how one can trade-off hardware performance, which represent cost, with proper choice of system architecture which includes, among other factors, in-building radio environment, to arrive at an optimum network solution technically and economically.

  2. Communication: Rigorous quantum dynamics of O + O2 exchange reactions on an ab initio potential energy surface substantiate the negative temperature dependence of rate coefficients.

    Science.gov (United States)

    Li, Yaqin; Sun, Zhigang; Jiang, Bin; Xie, Daiqian; Dawes, Richard; Guo, Hua

    2014-08-28

    The kinetics and dynamics of several O + O2 isotope exchange reactions have been investigated on a recently determined accurate global O3 potential energy surface using a time-dependent wave packet method. The agreement between calculated and measured rate coefficients is significantly improved over previous work. More importantly, the experimentally observed negative temperature dependence of the rate coefficients is for the first time rigorously reproduced theoretically. This negative temperature dependence can be attributed to the absence in the new potential energy surface of a submerged "reef" structure, which was present in all previous potential energy surfaces. In addition, contributions of rotational excited states of the diatomic reactant further accentuate the negative temperature dependence.

  3. Short communication: Development of the first follicular wave dominant follicle on the ovary ipsilateral to the corpus luteum is associated with decreased conception rate in dairy cattle.

    Science.gov (United States)

    Miura, R; Haneda, S; Kayano, M; Matsui, M

    2015-01-01

    In this study, we examined the effect of the locations of the first-wave dominant follicle (DF) and corpus luteum (CL) on fertility. In total, 350 artificial insemination (AI) procedures were conducted (lactating dairy cows: n=238, dairy heifers: n=112). Ovulation was confirmed 24 h after AI. The locations of the first-wave DF and CL were examined 5 to 9d after AI using rectal palpation or transrectal ultrasonography. Lactating dairy cows and dairy heifers were divided into 2 groups: (1) the ipsilateral group (IG), in which the DF was ipsilateral to the CL; and (2) the contralateral group (CG), in which the DF was contralateral to the CL. Pregnancy was diagnosed using transrectal ultrasonography 40d after AI. Conception rates were 54.0% in all cattle: 48.9% in lactating dairy cows, and 58.9% in dairy heifers. The incidence of the first-wave DF location did not differ between IG and CG (all cattle: 184 vs. 166; lactating cows: 129 vs. 109; heifers: 55 vs. 57 for IG vs. CG). Conception rates were lower in IG than in CG (all cattle: 40.2 vs. 69.3%; lactating dairy cows: 38.0 vs. 67.0%; dairy heifers: 45.5 vs. 73.7%, for IG vs. CG). Conception rate was not affected by season or live weight in heifers and lactating cows. In addition, days in milk at AI, milk production, body condition score, and parity did not affect conception in lactating cows. In summary, development of the first-wave DF in the ovary ipsilateral to the CL was associated with reduced conception rates in both lactating cows and heifers.

  4. Demonstration of Multi-Gbps Data Rates at Ka-Band Using Software-Defined Modem and Broadband High Power Amplifier for Space Communications

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.; Landon, David G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen; McIntire, William K.; Metz, John L.; Smith, Francis J.

    2011-01-01

    The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 W and efficiency greater than 60 percent. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10(exp -9). The presented results include a plot of the received waveform constellation, BER vs. E(sub b)/N(sub 0) and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA s payload data rate can be increased by at least an order of magnitude (greater than 10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.

  5. Multichannel Human Body Communication

    Science.gov (United States)

    Przystup, Piotr; Bujnowski, Adam; Wtorek, Jerzy

    2016-01-01

    Human Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Performance of single and multichannel transmission with frequency modulation of analog signal has been tested. Experiment results show that HBC is a feasible solution for transmitting data between BSN nodes.

  6. Tariff design for communication-capable metering systems in conjunction with time-variant electricity consumption rates; Gestaltung von Tarifen fuer kommunikationsfaehige Messsysteme im Verbund mit zeitvariablen Stromtarifen. Eine empirische Analyse von Praeferenzen privater Stromkunden in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Gerpott, Torsten J.; Paukert, Mathias [Duisburg-Essen Univ., Duisburg (Germany). Lehrstuhl Unternehmens- und Technologieplanung, Schwerpunkt Telekommunikationswirtschaft

    2013-06-15

    In Germany too, communication-capable electricity metering systems (CMS) together with time-based differentiation of kWh-rates for energy consumption are increasingly proliferated among household customers. Nevertheless, empirical evidence with respect to preferences of members of this customer group for the design of CMS tariff elements and of time-variant electricity consumption rates is still scarce. The present study captures such preferences by means of conjoint analysis of data obtained in an online survey of 754 German-speaking adults. Examined CMS tariff elements are a one-off installation fee and monthly recurring use charges. The studied characteristics of time-based rates are the number of time/tariff blocks, the maximum spread between kWh-rates for different time windows and the adaptability/predictability of kWh-rates. Most respondents judged multidimensional CMS and electricity consumption tariff offerings mainly in light of the CMS tariff characteristics. The vast majority of the participants perceived kWh-rates, which may change with a minimum lead time of one day as reducing the benefit of CMS and consumption tariff bundles. Tariff preferences on the one hand were only rarely significantly related to customers' socio-demographic and electricity procurement characteristics as well as their CMS-related expectations/assessments on the other. The willingness to accept CMS-related one-off installation and recurring service charges as well as the propensity to opt for time-dependent electricity consumption tariff variants differing clearly from non-differentiated electricity price schemes appear to be positively affected by customers' practical application experience with CMS and time-variant electricity consumption rates. Conclusions are drawn for energy suppliers seeking to propagate CMS-based time-variant tariffs among household customers in Germany and for future scholarly research. (orig.)

  7. BASALT 1: Extravehicular Activity Science Operations Concepts under Communication Latency and Bandwidth Constraints at Craters of the Moon, Idaho

    Science.gov (United States)

    Chappell, Steven P.; Beaton, Kara; Miller, Matthew J.; Lim, Darlene S. S.; Abercromby, Andrew F. J.

    2017-01-01

    conservative and affordable flight data rate, and a higher bandwidth case (5.0 Mb/s uplink, 10.0 Mb/s downlink), representing an upgraded human mission capability that would require additional infrastructure and technology development. In all conditions, two EVA crewmembers communicated with two intravehicular (IV) crewmembers with high bandwidth and near-zero communication latency, simulating communication among crewmembers on Mars. EVA crewmembers wore simulated EVA informatics backpacks including communication systems, position tracking, hand-held field spectrometers, cameras, and sample collection tools. Bidirectional communication between crewmembers ("Mars") and a Mission Support Center ("Earth"), staffed by a team of science and operations experts, was subject to the aforementioned latency and bandwidth constraints. This paper presents the synthesized results of the BASALT 1 deployment with respect to ConOps and capabilities assessment. Evaluation of the ConOps and capabilities was accomplished through a combination of network analytical data, completion of scientific objectives, ethnographic observations, planned versus actual timeline data, and collection of subjective ratings and comments using the same methodology employed during multiple previous NASA analog tests. In addition to assessing the acceptability of the ConOps and capabilities from scientific and operational perspectives, the extent to which specific capabilities enabled or enhanced the science operations was also evaluated. These data will provide a basis for prioritization of capability development for future BASALT deployments and, ultimately, future human exploration missions.

  8. Communication theory

    DEFF Research Database (Denmark)

    Stein, Irene F.; Stelter, Reinhard

    2011-01-01

    Communication theory covers a wide variety of theories related to the communication process (Littlejohn, 1999). Communication is not simply an exchange of information, in which we have a sender and a receiver. This very technical concept of communication is clearly outdated; a human being...... is not a data processing device. In this chapter, communication is understood as a process of shared meaning-making (Bruner, 1990). Human beings interpret their environment, other people, and themselves on the basis of their dynamic interaction with the surrounding world. Meaning is essential because people...... ascribe specific meanings to their experiences, their actions in life or work, and their interactions. Meaning is reshaped, adapted, and transformed in every communication encounter. Furthermore, meaning is cocreated in dialogues or in communities of practice, such as in teams at a workplace or in school...

  9. Strategizing Communication

    DEFF Research Database (Denmark)

    Gulbrandsen, Ib Tunby; Just, Sine Nørholm

    not determine the success of strategic communication. Rather, contextual factors such as competition, technological developments, global cultural trends and local traditions as well as employees’ skills and attitudes will determine the organization’s communicative success. This holds true regardless......Strategizing Communication offers a unique perspective on the theory and practice of strategic communication. Written for students and practitioners interested in learning about and acquiring tools for dealing with the technological, environmental and managerial challenges, which organizations face...... when communicating in today’s mediascape, this book presents an array of theories, concepts and models through which we can understand and practice communication strategically. The core of the argument is in the title: strategizing – meaning the act of making something strategic. This entails looking...

  10. Short communication: Estimation of the financial benefit of using Jersey milk at different inclusion rates for Cheddar cheese production using partial budgeting.

    Science.gov (United States)

    Bland, J H; Bailey, A P; Grandison, A S; Fagan, C C

    2015-03-01

    Partial budgeting was used to estimate the net benefit of blending Jersey milk in Holstein-Friesian milk for Cheddar cheese production. Jersey milk increases Cheddar cheese yield. However, the cost of Jersey milk is also higher; thus, determining the balance of profitability is necessary, including consideration of seasonal effects. Input variables were based on a pilot plant experiment run from 2012 to 2013 and industry milk and cheese prices during this period. When Jersey milk was used at an increasing rate with Holstein-Friesian milk (25, 50, 75, and 100% Jersey milk), it resulted in an increase of average net profit of 3.41, 6.44, 8.57, and 11.18 pence per kilogram of milk, respectively, and this additional profit was constant throughout the year. Sensitivity analysis showed that the most influential input on additional profit was cheese yield, whereas cheese price and milk price had a small effect. The minimum increase in yield, which was necessary for the use of Jersey milk to be profitable, was 2.63, 7.28, 9.95, and 12.37% at 25, 50, 75, and 100% Jersey milk, respectively. Including Jersey milk did not affect the quantity of whey butter and powder produced. Although further research is needed to ascertain the amount of additional profit that would be found on a commercial scale, the results indicate that using Jersey milk for Cheddar cheese making would lead to an improvement in profit for the cheese makers, especially at higher inclusion rates.

  11. Intersatellite communications optoelectronics research at the Goddard Space Flight Center

    Science.gov (United States)

    Krainak, Michael A.

    1992-01-01

    A review is presented of current optoelectronics research and development at the NASA Goddard Space Flight Center for high-power, high-bandwidth laser transmitters; high-bandwidth, high-sensitivity optical receivers; pointing, acquisition, and tracking components; and experimental and theoretical system modeling at the NASA Goddard Space Flight Center. Program hardware and space flight opportunities are presented.

  12. [Verbal communication].

    Science.gov (United States)

    Fiorini, Fulvio; Panini, Roberta; Ameri, Cinzia

    2014-01-01

    The communication is an action that occupies a lot of part of the life of every individual and understands a whole activity that the purpose has to reach a preset goal: the communication obligatorily foresees the presence of a recipient/receiving.During communication we used both the word, but also the gesture and the way of do/say. The oral communication represents the most complete system however, evolved, end and thin to communicate, able to also express concepts and thoughts and not only behaviors: with it he can also lie and to supply misinformation. The oral communication also possesses an important temporal value, in how much you/he/she can define him now, the before and the then, but also the ability to determine the human relationships, because it participates in to define the different roles in which broadcasting station and receiver are found at that time. The truest power of the words is that to create, to maintain, to modify other people's behaviors; a natural correlation exists that is between communication and behavior. The final objective of the communication results therefore that to create or to modify the relationships and the human behaviors; in other terms we can be affirmed that the words can determine the reality. The true ragion to be to communicate is the purpose however, that who speaks he/she wants to reach: it is a voluntary, both mental and physical effort, that originates from a need both explicit and implicit of whom sends forth the message.

  13. Alive communication.

    Science.gov (United States)

    Fogel, Alan; Garvey, Andrea

    2007-05-01

    The purpose of this paper is to propose a theoretical model, based on a dynamic systems perspective and the metaphor of aliveness in communication. Traditional concepts and methods for the study of communication are relatively static and based on the metaphor of signal and response. These traditional methods lend themselves to relatively simplified measures of frequencies and durations, sequences and co-occurrences: a model of objectified communication. The concept of alive communication focuses on the dynamically changing aspects of communication using three related components: coregulation, ordinary variability, and innovation. Like living organisms, alive communication develops over time as it forms dynamically stable patterns. Aliveness can be applied to communication at any age, in any species, between species, in any form including time-delayed practices using written symbols, and with non-living objects. The model provides a tool for evaluating the "life-likeness" of communication with animate and inanimate objects and robotic devices, and for assessing and treating communicative difficulties--in which aliveness is missing--within and between dyads/families.

  14. Postcultural Communication?

    DEFF Research Database (Denmark)

    Jensen, Iben

    2015-01-01

    When we as scholars use the concept of intercultural communication in its classic definition, as communication between people with different cultural backgrounds, we perpetuate the notion that national differences influence communication more than other differences; in doing so, ethnic minorities...... in multicultural societies are silently/verbally excluded from national communities. The aim of the article is to develop a theoretical position, which is able to conceptualize intercultural communication in complex multicultural societies and function as a frame for empirical analysis. The theoretical position...... is presented as a postcultural prism composed by practice theory (Schatzki 1996, Reckwitz 2002, Nicolini 2012, Kemmis 2012), Intersectionality (Brah, Phoenix, Collins Rahsack) and positioning theory (Harre & Langenhove 1998)....

  15. Short communication: The effect of 4 antiseptic compounds on umbilical cord healing and infection rates in the first 24 hours in dairy calves from a commercial herd.

    Science.gov (United States)

    Robinson, A L; Timms, L L; Stalder, K J; Tyler, H D

    2015-08-01

    The objective of this study was to compare the effect of 4 antiseptic compounds on the healing rate and incidence of infection of umbilical cords in newborn calves (n=60). Late gestation Jersey cows were monitored at a commercial farm (Sioux Jersey, Salix, IA) and newborn purebred (n=30) and crossbred (n=30) calves were obtained within 30min after birth. Calves were alternately assigned by birth order to 4 treatment groups: 7% tincture of iodine, 0.1% chlorine created using a novel chlorine disinfectant technology, chlorohexidine gluconate 4.0% wt/vol, and 10% trisodium citrate. Prior to dipping (within 30min of birth), diameter of the umbilical cords (as an indicator of cord drying and healing) were determined using digital calipers. In addition, as an indicator of umbilical infections, surface temperature of the umbilical stump (along with a reference point at the midpoint of the sternum) was determined using a dual-laser infrared thermometer. These measurements were all repeated at 24±1 h of age. All data were analyzed using mixed model methods. All models included fixed effects of breed (Jersey or Jersey cross), sex (bull or heifer), and treatment. Fixed effect interactions were not included in the statistical model due to the relatively small sample size. No treatment differences were noted for healing rate of umbilical cords. Initially, mean umbilical cord diameter was 22.84±3.89mm and cords healed to a mean diameter of 7.64±4.12mm at 24 h of age. No umbilical infections were noted for calves on any treatment during the course of this study. Mean surface temperature of the umbilical stump was 33.1±2.2°C at birth (1.5±1.6°C higher than the sternal reference temperature), and at 24±1 h of age the mean temperature of the umbilical stump was 33.0±4.3°C (0.5±1.8°C lower than the sternal reference temperature). These data suggest that these antiseptic compounds are equally effective for preventing infections and permitting healing of the umbilical cord

  16. Communicating up

    Science.gov (United States)

    Lum, Lydia

    2013-01-01

    Chief communicators at many U.S. institutions are interested in forging closer ties with governing boards. Proponents say such relationships can increase board trust and confidence in communicators before a crisis occurs, making it easier to manage the institution's reputation and limit negative publicity when one does. At some institutions, such…

  17. Interracial Communication

    Science.gov (United States)

    Harris, Tina M.

    2004-01-01

    This course explores the inextricable and multidimensional relationships among race, culture, and communication by providing students with an extensive theoretical framework to enhance their understanding of interracial communication. Specific attention is geared toward the construction of one's own racial and ethnic identity as well as those of…

  18. Industrial Communications.

    Science.gov (United States)

    Lindsay, Dan

    Intended for seniors planning a career in industry as skilled laborers, this specialized course in Industrial Communications offers the student basic communications skills which he will need in his work and in his daily life. Since class activities center around short, factual oral reports, class size will be limited to 20, providing a maximum of…

  19. Influence of partially coherent beam passing through strong turbulence on bit error rate of laser communication systems%部分相干光通过强湍流对通信系统误码率的影响

    Institute of Scientific and Technical Information of China (English)

    王江安; 赵英俊; 吴荣华; 任席闯

    2009-01-01

    A theoretical base for using the technology of multibeam transmission and the reception in the ship laser communication systems was provided by the research on the influence of partially coherent beams passing through the strong turbulence on the bit error rate. The relation between system bit error rate and transmission range was obtained under the conditions of different turbulence measurement, transmission laser wavelength and light source coherence parameter by the aid of a method to parse the equation of laser transmission in atmospheric turbulence field, ignoring other noises in the system, but considering the bit error rate caused by atmospheric turbulence only. The result indicates that under the strong turbulence condition, the system bit error rate is increased gradually with the increase of the transmission range when the quantity of transmitting antennas reaches a certain number, but the system bit error rate tends to saturation when the transmission range accretion reaches a definite degree; the bigger the light source coherence parameter increases, the lower the system bit error rate becomes; the more the turbulence inner scale is, the higher the system bit error rate becomes; and the variation of the transmission laser wavelength has no obvious influence on the system bit error rate.%为研究部分相干光通过强湍流对系统误码率的影响,借助对激光在大气湍流场中的传输方程进行解析求解(忽略系统中其他噪声,仅考虑由大气湍流引起的系统误码率),得到不同湍流内尺度、传输激光波长和光源相干参数条件下,系统误码率和传输距离的关系.结果表明:在强湍流条件下,当发射天线数目达到一定时,随着传输距离的增加,系统误码率逐渐增大,但增大到一定程度后趋于饱和;光源相干参数越大,系统误码率越低;湍流内尺度越大,系统误码率越高;传输激光波长的变化对系统误码率无明显影响.

  20. Communicating health.

    Science.gov (United States)

    Chatterjee, A

    1995-01-01

    Routine production of communication materials without paying attention to utilization, field test, and impact analysis is ineffective. The concept of information, education, and communication (IEC) should encompass voluntary activity of health education in a tradition of innovation. One seminal factor may be the communication technologies developed by the National Technology Missions. The missions were participatory by seeking solutions among communities and analyzing health issues from the perspective of those directly involved, rather than from the top down. The prime focus of the national drinking water mission was convenience, hence messages concentrating on health advantages were ignored. At this juncture, influencing health behavior required decentralization reflecting local cultures. Thus community-based partners became the foundation of a strategy of communicating safe water. As national strategies emerged in each of the technology missions, communication addressed advocacy of the need for political will, dissemination of technical information, and influencing patterns of behavior. Despite learning a new understanding, the danger exists that IEC remains just another label of mass communication with posters, advertisements, brochures, radio, and television. Decisions on contraceptive choice and use requires more than just accurate information; it requires the power to make such a decision. A new approach demands a priority for communication skills taking into account people's aspirations. The HIV-AIDS crisis underlines the urgency with which communication has to respond to health challenges. A series of experiments facilitated by the World Conservation Union helped build communication capabilities among environmental groups working in Latin America, Africa, and India. The International Reference Center on Water and Sanitation initiated pilot communication projects in West Africa for community health.

  1. Cross-Layer Design For Energy-Efficient In Wireless Underwater Communication: Acoustic Frequency IDentification Case Study

    Directory of Open Access Journals (Sweden)

    Ghada Zaibi

    2011-05-01

    Full Text Available Thanks to the recent developments on communication techniques, micro-technology and on digital electronics, Underwater Wireless Sensor Networks (UWSNs are being employed in several types of underwater applications such as wireless identification named Acoustic Frequency Identification (AFID. In this research, we are trying to adapt concepts of wireless acoustic identification to the difficult underwater environment with its hard constraints especially absence of high bandwidth communication (no radio.So, there is a critical parameter in UWSN making challenge because it determines how longer sensor nodes and the entire networks would remain functional. However, in these types of Networks, node's battery presents a limited energy resource and network lifetime is related to the energy consumption by a node. Thus, in this paper we will propose some contributions and cross-layer design to prolong the AFID network lifetime.

  2. Intercultural Communication

    Directory of Open Access Journals (Sweden)

    Georgeta Modiga

    2014-05-01

    Full Text Available The concept of culture has become one of strategic importance for all disciplines studying human and social universe, being invested today with multiple explanatory connotations. Meanwhile, conjunction and theoretical approaches we witness interference, under the imperative of interdisciplinary vision lead us, often up to a damaging confusion between communication and culture. Distinction between symbolic and instrumental, of culture and civilization are necessary to not confuse the contents of symbolic culture media of communication technology. An inventory of issues and social transformations that have acquired an indisputable relevance in contemporary development equation surgery is necessary but difficult. It should be mentioned two of them, given their global significance: the rediscovery of culture as a defining factor of the social and importance that have acquired communication processes in living societies. In fact, between the two aspects there is a relationship of inherent and consubstantiality, validated by actual historical experience. Culture and Communication is now a binomial with terms interchangeably, the two processes intertwined in a single block. Welding of the two dimensions was otherwise devoted to the vocabulary of social sciences and humanities through the concepts of culture media and intercultural communication. If we examine the paradigm shift in the theoretical space of the last century, the most surprising phenomena that we observe is that theories concerning communication space literally invaded the area that was traditionally reserved for theories about culture. For theorists today, communication is a structural constituent and all definitions, descriptions and characterizations that build on contemporary culture.

  3. Science communication as political communication.

    Science.gov (United States)

    Scheufele, Dietram A

    2014-09-16

    Scientific debates in modern societies often blur the lines between the science that is being debated and the political, moral, and legal implications that come with its societal applications. This manuscript traces the origins of this phenomenon to professional norms within the scientific discipline and to the nature and complexities of modern science and offers an expanded model of science communication that takes into account the political contexts in which science communication takes place. In a second step, it explores what we know from empirical work in political communication, public opinion research, and communication research about the dynamics that determine how issues are debated and attitudes are formed in political environments. Finally, it discusses how and why it will be increasingly important for science communicators to draw from these different literatures to ensure that the voice of the scientific community is heard in the broader societal debates surrounding science.

  4. Science communication as political communication

    Science.gov (United States)

    Scheufele, Dietram A.

    2014-01-01

    Scientific debates in modern societies often blur the lines between the science that is being debated and the political, moral, and legal implications that come with its societal applications. This manuscript traces the origins of this phenomenon to professional norms within the scientific discipline and to the nature and complexities of modern science and offers an expanded model of science communication that takes into account the political contexts in which science communication takes place. In a second step, it explores what we know from empirical work in political communication, public opinion research, and communication research about the dynamics that determine how issues are debated and attitudes are formed in political environments. Finally, it discusses how and why it will be increasingly important for science communicators to draw from these different literatures to ensure that the voice of the scientific community is heard in the broader societal debates surrounding science. PMID:25225389

  5. Satellite Communications

    CERN Document Server

    Pelton, Joseph N

    2012-01-01

    The field of satellite communications represents the world's largest space industry. Those who are interested in space need to understand the fundamentals of satellite communications, its technology, operation, business, economic, and regulatory aspects. This book explains all this along with key insights into the field's future growth trends and current strategic challenges. Fundamentals of Satellite Communications is a concise book that gives all of the key facts and figures as well as a strategic view of where this dynamic industry is going. Author Joseph N. Pelton, PhD, former Dean of the International Space University and former Director of Strategic Policy at Intelstat, presents a r

  6. Communicating EAM

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh

    Since the early years of electro acoustic music great self-awareness is found among the field’s composers who often and willingly have communicated historical chronology, thoughts about analysis, aesthetic directions and rivalries. This we find both in relation to the historical studios (Schaeffe......Since the early years of electro acoustic music great self-awareness is found among the field’s composers who often and willingly have communicated historical chronology, thoughts about analysis, aesthetic directions and rivalries. This we find both in relation to the historical studios......’s communication of EAM and Sound Art....

  7. Securing underwater wireless communication networks

    OpenAIRE

    Domingo Aladrén, Mari Carmen

    2011-01-01

    Underwater wireless communication networks are particularly vulnerable to malicious attacks due to the high bit error rates, large and variable propagation delays, and low bandwidth of acoustic channels. The unique characteristics of the underwater acoustic communication channel, and the differences between underwater sensor networks and their ground-based counterparts require the development of efficient and reliable security mechanisms. In this article, a compl...

  8. Compressive Sampling for Wireless Communications

    NARCIS (Netherlands)

    Gishkori, S.S.

    2014-01-01

    Wireless communications is undergoing massive development in all forms of its manifestations. In the field of short-range communications, technologies like ultra- wideband (UWB) systems are promising very high data rates, fine timing resolution and coexistence with other physical layer standards. Al

  9. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group, established at the start of 2010, has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure There are now 55 CMS Centres worldwide that are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS offline and computing operations, hosting dedicated analysis efforts such as during the CMS Heavy Ion lead-lead running. With a majority of CMS sub-detectors now operating in a “shifterless” mode, many monitoring operations are now routinely performed from there, rather than in the main Control Room at P5. The CMS Communications Group, CERN IT and the EVO team are providing excellent videoconferencing support for the rapidly-increasing number of CMS meetings. In parallel, CERN IT and ...

  10. COMMUNICATIVE COMPETENCE

    Directory of Open Access Journals (Sweden)

    Józef Podgórecki

    2015-01-01

    Full Text Available The paper presents the most significant factors that influence interpersonal and group communication in multicultural environment in education. It highlights main theories of intercultural communication and its effectiveness as well as ones which deal with coping with conflicts in the intercultural environment. In contemporary times, which require working in multicultural environment, communicative skills become more and more important. In teachers’ work cultural awareness and being openminded about differences between nations and cultures are essential. These skills are especially important while there is a need to avoid or overcome problems, conflicts which may occur. The author shows the significance of these factors. The article closes with the recommendations and clues concerning effective intercultural communication.

  11. Communication Acoustics

    DEFF Research Database (Denmark)

    Blauert, Jens

    the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... chapters represent review articles covering the most relevant areas of the field. They are written with the goal of providing students with comprehensive introductions. Further they offer a supply of numerous references to the relevant literature. Besides its usefulness as a textbook, this will make...

  12. Communicating biosecurity.

    Science.gov (United States)

    Briggs, Charles L

    2011-01-01

    Shifting from risk-calculation orientations focusing on populations to preparedness perspectives that model uncertainty through scenario-based projections, biosecurity debates redefined notions of "health" and "security." Nevertheless, a key focus of biosecurity discussions--the domain labeled "communication"--has not been fundamentally rethought, even as it has expanded and professionalized. Bracketing preconceived ideas about the term's content, the article traces debates about biosecurity "communication" from the 1990s to the present, drawing on ethnography and textual analysis. Using a notion of biocommunicability, the cultural modeling of how discourse is produced, circulates, and is received, the article analyzes assumptions regarding subjects, subject-positions, objects, spatializing and temporalizing practices, scales, economies of affect, and regimes of ethics that are built into discourse about "communication." Ironically, the conviction that "communication" is of marginal importance as a focus of critical inquiry, seemingly shared by most medical anthropologists, enables these assumptions to fundamentally shape discussions of biosecurity and emergency management.

  13. Communication breakdown?

    Science.gov (United States)

    Kron, Tomas

    2017-04-01

    In response to Brian Clegg's feature article “Speaking a different language” (February pp34-37), in which he suggests that a good science communicator anticipates the kind of questions the audience will want to have answered.

  14. An ATP System for Deep-Space Optical Communication

    Science.gov (United States)

    Lee, Shinhak; Irtuzm Gerardi; Alexander, James

    2008-01-01

    An acquisition, tracking, and pointing (ATP) system is proposed for aiming an optical-communications downlink laser beam from deep space. In providing for a direction reference, the concept exploits the mature technology of star trackers to eliminate the need for a costly and potentially hazardous laser beacon. The system would include one optical and two inertial sensors, each contributing primarily to a different portion of the frequency spectrum of the pointing signal: a star tracker (50 Hz. The outputs of these sensors would be combined in an iterative averaging process to obtain high-bandwidth, high-accuracy pointing knowledge. The accuracy of pointing knowledge obtainable by use of the system was estimated on the basis of an 8-cm-diameter telescope and known parameters of commercially available star trackers and inertial sensors: The single-axis pointing-knowledge error was found to be characterized by a standard deviation of 150 nanoradians - below the maximum value (between 200 and 300 nanoradians) likely to be tolerable in deep-space optical communications.

  15. Animal communication.

    Science.gov (United States)

    Kaplan, Gisela

    2014-11-01

    Animal communication is first and foremost about signal transmission and aims to understand how communication occurs. It is a field that has contributed to and been inspired by other fields, from information technology to neuroscience, in finding ever better methods to eavesdrop on the actual 'message' that forms the basis of communication. Much of this review deals with vocal communication as an example of the questions that research on communication has tried to answer and it provides an historical overview of the theoretical arguments proposed. Topics covered include signal transmission in different environments and different species, referential signaling, and intentionality. The contention is that animal communication may reveal significant thought processes that enable some individuals in a small number of species so far investigated to anticipate what conspecifics might do, although some researchers think of such behavior as adaptive or worth dismissing as anthropomorphizing. The review further points out that some species are more likely than others to develop more complex communication patterns. It is a matter of asking how animals categorize their world and which concepts require cognitive processes and which are adaptive. The review concludes with questions of life history, social learning, and decision making, all criteria that have remained relatively unexplored in communication research. Long-lived, cooperative social animals have so far offered especially exciting prospects for investigation. There are ample opportunities and now very advanced technologies as well to tap further into expressions of memory of signals, be they vocal or expressed in other modalities. WIREs Cogn Sci 2014, 5:661-677. doi: 10.1002/wcs.1321 For further resources related to this article, please visit the WIREs website. The author has declared no conflicts of interest for this article. © 2014 John Wiley & Sons, Ltd.

  16. Department Chairs' Perceptions of the Importance of Business Communication Skills.

    Science.gov (United States)

    Wardrope, William J.

    2002-01-01

    Determines business department chairs' ratings of topics typically covered in the business communication course. Indicates that department chairs perceive writing skills to be more important to business communication courses than other communication skills, such as speaking, technology-mediated communication, interpersonal communication,…

  17. Department Chairs' Perceptions of the Importance of Business Communication Skills.

    Science.gov (United States)

    Wardrope, William J.

    2002-01-01

    Determines business department chairs' ratings of topics typically covered in the business communication course. Indicates that department chairs perceive writing skills to be more important to business communication courses than other communication skills, such as speaking, technology-mediated communication, interpersonal communication,…

  18. Aesthetic Communication

    DEFF Research Database (Denmark)

    Thyssen, Ole

    2012-01-01

    Based on Niklas Luhmann's systems theory, aesthetics is defined as a manner of reinforcing the connectivity, or Anschlusswert, of communication. Without changing the content, a message can be made more attractive, strengthening the receiver's willingness to be attentive and accepting. As communic......Based on Niklas Luhmann's systems theory, aesthetics is defined as a manner of reinforcing the connectivity, or Anschlusswert, of communication. Without changing the content, a message can be made more attractive, strengthening the receiver's willingness to be attentive and accepting....... As communication inevitably makes use of a sensuous medium, such as light or sound, all communication has an aesthetic dimension. In the 19th Century, an important distinction was made between pure and applied art, following Immanuel Kant's separation of theory of knowledge, moral theory and aesthetic theory....... Whereas pure art is produced in order to be observed, applied art has to fulfill practical purposes as well. Modern organizations, defined as systems of communication, may use art works to embellish and define themselves. But they inevitably use applied art as a practical tool in their normal...

  19. Characterization and Design of Digital Pointing Subsystem for Optical Communication Demonstrator

    Science.gov (United States)

    Racho, C.; Portillo, A.

    1998-01-01

    The Optical Communications Demonstrator (OCD) is a laboratory-based lasercom demonstration terminal designed to validate several key technologies, including beacon acquisition, high bandwidth tracking, precision bearn pointing, and point-ahead compensation functions. It has been under active development over the past few years. The instrument uses a CCD array detector for both spatial acquisition and high-bandwidth tracking, and a fiber coupled laser transmitter. The array detector tracking concept provides wide field-of-view acquisition and permits effective platform jitter compensation and point-ahead control using only one steering mirror. This paper describes the detailed design and characterization of the digital control loop system which includes the Fast Steering Mirror (FSM), the CCD image tracker, and the associated electronics. The objective is to improve the overall system performance using laboratory measured data. The. design of the digital control loop is based on a linear time invariant open loop model. The closed loop performance is predicted using the theoretical model. With the digital filter programmed into the OCD control software, data is collected to verify the predictions. This paper presents the results of the, system modeling and performance analysis. It has been shown that measurement data closely matches theoretical predictions. An important part of the laser communication experiment is the ability of FSM to track the laser beacon within the. required tolerances. The pointing must be maintained to an accuracy that is much smaller than the transmit signal beamwidth. For an earth orbit distance, the system must be able to track the receiving station to within a few microradians. The failure. to do so will result in a severely degraded system performance.

  20. Communication with Disturbance Constraints

    CERN Document Server

    Bandemer, Bernd

    2011-01-01

    The problem of communication with disturbance constraints is introduced. The rate-disturbance region is established for the single constraint case. The optimal encoding scheme turns out to be the same as the Han-Kobayashi scheme for the two user-pair interference channel. For communication with two disturbance constraints, a coding scheme and a corresponding inner bound for the deterministic case are presented. The results suggest a natural way to obtain a new inner bound on the capacity region of the interference channel with more than two user pairs.

  1. Submarine neutrino communication

    CERN Document Server

    Huber, Patrick

    2009-01-01

    We discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

  2. Submarine neutrino communication

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Patrick, E-mail: pahuber@vt.ed [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2010-09-06

    We discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

  3. Submarine neutrino communication

    Science.gov (United States)

    Huber, Patrick

    2010-09-01

    We discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

  4. Acoustic Communication for Medical Nanorobots

    CERN Document Server

    Hogg, Tad

    2012-01-01

    Communication among microscopic robots (nanorobots) can coordinate their activities for biomedical tasks. The feasibility of in vivo ultrasonic communication is evaluated for micron-size robots broadcasting into various types of tissues. Frequencies between 10MHz and 300MHz give the best tradeoff between efficient acoustic generation and attenuation for communication over distances of about 100 microns. Based on these results, we find power available from ambient oxygen and glucose in the bloodstream can readily support communication rates up to 10,000 bits/second between micron-sized robots. We discuss techniques, such as directional acoustic beams, that can increase this rate. The acoustic pressure fields enabling this communication are unlikely to damage nearby tissue, and short bursts at considerably higher power could be of therapeutic use.

  5. Communicating Science

    Science.gov (United States)

    Holland, G. J.; McCaffrey, M. S.; Kiehl, J. T.; Schmidt, C.

    2010-12-01

    We are in an era of rapidly changing communication media, which is driving a major evolution in the modes of communicating science. In the past, a mainstay of scientific communication in popular media was through science “translators”; science journalists and presenters. These have now nearly disappeared and are being replaced by widespread dissemination through, e.g., the internet, blogs, YouTube and journalists who often have little scientific background and sharp deadlines. Thus, scientists are required to assume increasing responsibility for translating their scientific findings and calibrating their communications to non-technical audiences, a task for which they are often ill prepared, especially when it comes to controversial societal issues such as tobacco, evolution, and most recently climate change (Oreskes and Conway 2010). Such issues have been politicized and hi-jacked by ideological belief systems to such an extent that constructive dialogue is often impossible. Many scientists are excellent communicators, to their peers. But this requires careful attention to detail and logical explanation, open acknowledgement of uncertainties, and dispassionate delivery. These qualities become liabilities when communicating to a non-scientific audience where entertainment, attention grabbing, 15 second sound bites, and self assuredness reign (e.g. Olson 2009). Here we report on a program initiated by NCAR and UCAR to develop new approaches to science communication and to equip present and future scientists with the requisite skills. If we start from a sound scientific finding with general scientific consensus, such as the warming of the planet by greenhouse gases, then the primary emphasis moves from the “science” to the “art” of communication. The art cannot have free reign, however, as there remains a strong requirement for objectivity, honesty, consistency, and above all a resistance to advocating particular policy positions. Targeting audience

  6. Why Communicate

    Science.gov (United States)

    Illingworth, Samuel

    2015-04-01

    "Half the world is composed of people who have something to say and can't, and the other half who have nothing to say and keep on saying it." - Robert Frost In this age of digital soap boxes and half-truths, the importance of geoscientists as communicators cannot be underestimated, nor has there been a more important time for researchers to stand up and demand to be heard. So why is there still such an overwhelming public perception that scientists are poor communicators, and what can we do to change this? In this work I will present an overview of a number of successful initiatives that have been developed at Manchester Metropolitan University, and beyond, to ensure that science is communicated to a large variety of people, from policy makers to members of the local community. I will also present an overview of the emerging field of Science Communication, how it has changed in the past few decades from a one-way diatribe to a two-way discussion, and how this represents a possible new direction and career path for geoscientists. Anne Roe, the noted American psychologist, told us, "nothing in science has any value to society if it is not communicated." As geoscientists, we have a professional and moral obligation to ensure that we not only research the facts, but that we also present them in an informative and engaging manner, so that the rest of humanity can benefit from the fruits of our labour.

  7. 低速率物联网蜂窝通信技术现状及发展趋势%The Status and Trend of Low Rate Cellular Communication Technology for IoT

    Institute of Scientific and Technical Information of China (English)

    赵静

    2016-01-01

    低速率应用占据了物联网应用的最大比重,同时这类应用还兼具低功耗、低成本等特点。为了满足这类应用的需求,3GPP制定了Cat.1、Cat.0,以及标准即将冻结的Cat.M和NB-IoT。针对这些低功耗蜂窝通信技术的演进路线进行了阐述,并从技术背景、标准进展、技术参数、应用场景、网络部署等角度详细对比了Cat.M和NB-IoT两种超低功耗通信技术,分析了二者如何发展和应用的关键问题。%Low rate applications accounted for the largest share of IoT applications, which are featured as low power and low cost at the same time. In order to meet the demands of such applications, 3GPP has established Cat1/Cat0, as well as Cat.M and NB-IoT which will be frozen soon as a standard. This paper depicted the evolution of these low rate cellular communication technology, and also compared Cat.M and NB-IoT from the point of technology background, progress of standard, technical parameters, application scenarios, network deployment etc., answered the key question about the prospect and application of the two technology.

  8. Interlimb communication

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas

    A continual coordination between the two legs is necessary for maintaining a symmetric walking pattern and adapting to changes in the external environment. Recent evidence in animals and humans suggests that spinal interneuronal circuits under supraspinal control may mediate communication between...... the lower limbs. The overall objective of the present thesis was to further investigate and elucidate neural pathways underlying interlimb communication in humans, focusing primarily on the possible interlimb connections to the biceps femoris muscle. The major aims were 1) to investigate whether interlimb...... walking (Study IV). The results of the this thesis provide new insights into the neural mechanisms underlying human interlimb communication, as well as their functional relevance to human locomotion. Although it is difficult to propose the exact neural pathways mediating interlimb reflexes...

  9. Communication & Management

    CERN Multimedia

    2006-01-01

    Calendar of courses for September to December 2006 Please check our Web site to find out the number of places available, which may vary. Management Curriculum 2nd semester 2006 Titles Dates Language Quality Management 18, 19 September Bilingual Managing Teams 19, 20, 21 September English Communicating Effectively - Residential 20, 21, 22 septembre Bilingual (Full) Personal Awareness & Impact 26, 27, 28 September Bilingual Introduction to Leadership 4, 5, 6 October Bilingue IProject Scheduling & Costing 12, 13 October English CDP-SL part 1 Several sessions Dates to be fixed English or French Personal Awareness & Impact 23, 24 October Bilingual Communicating to Convince 23, 24, 25 October Bilingual CDP-GL part 2 25, 26, 27 October English CDP-GL part 1 Dates to be fixed Bilingual Risk Management 20, 21 December Bilingual Communication curriculum 2nd semester 2006 Titles Dates Language Techniques d'exposé et de présentation 18, 19 s...

  10. Management & Communication

    CERN Multimedia

    2006-01-01

    Calendar of courses for September to December 2006 Please check our Web site to find out the number of places available, which may vary. Management Curriculum 2nd semester 2006 Titles Dates Language Quality Management 18, 19 September Bilingual Managing Teams 19, 20, 21 September English Communicating Effectively - Residential 20, 21, 22 septembre Bilingual (Full) Personal Awareness & Impact 26, 27, 28 September Bilingual Introduction to Leadership 4, 5, 6 October Bilingue IProject Scheduling & Costing 12, 13 October English CDP-SL part 1 Several sessions Dates to be fixed English or French Personal Awareness & Impact 23, 24 October Bilingual Communicating to Convince 23, 24, 25 October Bilingual CDP-GL part 2 25, 26, 27 October English CDP-GL part 1 Dates to be fixed Bilingual Risk Management 20, 21 December Bilingual Communication curriculum 2nd semester 2006 Titles Dates Language Techniques d'exposé et de présentation 18, 19 sept...

  11. Communication & Management

    CERN Multimedia

    Nathalie Dumeaux

    2006-01-01

    Calendar of courses for September to December 2006 Please check our Web site to find out the number of places available, which may vary. Management Curriculum 2nd semester 2006 Titles Dates Language Quality Management 18, 19 September Bilingual Managing Teams 19, 20, 21 September English Communicating Effectively - Residential 20, 21, 22 septembre Bilingual (Full) Personal Awareness & Impact 26, 27, 28 September Bilingual Introduction to Leadership 4, 5, 6 October Bilingue IProject Scheduling & Costing 12, 13 October English CDP-SL part 1 Several sessions Dates to be fixed English or French Personal Awareness & Impact 23, 24 October Bilingual Communicating to Convince 23, 24, 25 October Bilingual CDP-GL part 2 25, 26, 27 October English CDP-GL part 1 Dates to be fixed Bilingual Risk Management 20, 21 December Bilingual Communication curriculum 2nd semester 2006 Titles Dates Language Techniques d'exposé et de présentation 18, 19 s...

  12. Optimum design of Cassegrain antenna for space laser communication

    Science.gov (United States)

    Hu, Yuan; Jiang, Lun; Wang, Chao; Li, Yingchao

    2016-10-01

    The divergence angle is very important index in space laser communication for energy transfer. Typically, the large aperture telescope as optical antenna is used for angle compression, and the divergence angle of communication beam is usually calculated by diffraction limit angle equation 1.22λ/D. This equation expresses the diffraction of a spherical wave through a circular aperture. However, the light source commonly used laser with a Gaussian distribution, and the optical antenna is central obscurations. The antenna parameters which is obscuration ratio and Gaussian beam apodization were significantly relative with the far field energy. In this study, we obtain the mathematic relation between the divergence angle, energy loss and the antenna parameters. From the relationship, we know that the divergence angle smaller as the increase of antenna obscuration ratio. It would tend to enhance the far-field energy density. But a larger obscuration ratio will increase the energy loss. At the same time, the increase of Gaussian beam apodization resulted in the energy of first diffraction ring was raised but the radius of first ring was increased. They were conflict. And then, the antenna parameters of trade-off was found from curves of obscuration ratio and curves of divergence angle. The parameters of a Cassegrain antenna was optimum designed for the energy maximization, and considerd the apodization from mechanical structure blocking. The long-distance laser communications were successful in these airborne tests. Stable communication was demonstrated. The energy gain is sufficient for SNR of high-bandwidth transmission in atmospheric channel.

  13. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  14. Scholarly Communication

    CERN Document Server

    Romary, Laurent

    2011-01-01

    The chapter tackles the role of scholarly publication in the research process (quality, preservation) and looks at the consequences of new information technologies in the organization of the scholarly communication ecology. It will then show how new technologies have had an impact on the scholarly communication process and made it depart from the traditional publishing environment. Developments will address new editorial processes, dissemination of new content and services, as well as the development of publication archives. This last aspect will be covered on all levels (open access, scientific, technical and legal aspects). A view on the possible evolutions of the scientific publishing environment will be provided.

  15. Digital communication

    CERN Document Server

    Das, Apurba

    2010-01-01

    ""Digital Communications"" presents the theory and application of the philosophy of Digital Communication systems in a unique but lucid form. This book inserts equal importance to the theory and application aspect of the subject whereby the authors selected a wide class of problems. The Salient features of the book are: the foundation of Fourier series, Transform and wavelets are introduces in a unique way but in lucid language; the application area is rich and resemblance to the present trend of research, as we are attached with those areas professionally; a CD is included which contains code

  16. Communications standards

    CERN Document Server

    Stokes, A V

    1986-01-01

    Communications Standards deals with the standardization of computer communication networks. This book examines the types of local area networks (LANs) that have been developed and looks at some of the relevant protocols in more detail. The work of Project 802 is briefly discussed, along with a protocol which has developed from one of the LAN standards and is now a de facto standard in one particular area, namely the Manufacturing Automation Protocol (MAP). Factors that affect the usage of networks, such as network management and security, are also considered. This book is divided into three se

  17. Communicating EAM

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh

    Since the early years of electro acoustic music great self-awareness is found among the field’s composers who often and willingly have communicated historical chronology, thoughts about analysis, aesthetic directions and rivalries. This we find both in relation to the historical studios (Schaeffe......Since the early years of electro acoustic music great self-awareness is found among the field’s composers who often and willingly have communicated historical chronology, thoughts about analysis, aesthetic directions and rivalries. This we find both in relation to the historical studios...

  18. Constructive communication

    CERN Document Server

    Ellis, Richard

    2012-01-01

    Richard Ellis is a consultant in communications and the successful author of 'Communication for Engineers'. In each chapter he highlights key points and situations, and provides exercises to consolidate what has already been learnt. The book ends with a 'toolbox' of useful information on subjects such as writing letters, spelling, punctuation, using abbreviations, studying for exams, using libraries and training.Written in clear, informative English, with the emphasis on the practical, this book is essential reading for both students and professionals in the con

  19. Crisis Communication: The Business Communicator's Strategies for Communicating under Stress.

    Science.gov (United States)

    Vielhaber, Mary E.

    1990-01-01

    Uses the 1979 Three Mile Island nuclear plant accident to illustrate the communication problems embedded in a crisis. Describes the reactions created by the stress related to crisis. Suggests business communication strategies for improving communication to the public. (SR)

  20. Magnetostatic communication

    Science.gov (United States)

    Daily, William D.

    2008-02-26

    A system for providing communication of information by modulating a magnetostatic field with a magnetostatic transmitter that modulates said magnetostatic field to contain the information and detecting the information in the modulated field at a distance with a magnetostatic detector that detects the modulated magnetic field containing the information.

  1. Communication Way

    Science.gov (United States)

    Atwood, Margaret

    1976-01-01

    Basic to Library-College thought is the Communication Way. Such a construct is theoretical in the sense it combines the structure of a discipline and the structure of a literature into a system which enables the learner to see that finding and thinking about given subject matter is a unified process. (Author)

  2. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS Offline and Computing operations, and a number of subdetector shifts can now take place there, rather than in the main Control Room at P5. A new CMS meeting room has been equipped for videoconferencing in building 42, next to building 40. Our building 28 meeting room and the facilities at P5 will be refurbished soon and plans are underway to steadily upgrade the ageing equipment in all 15 CMS meeting rooms at CERN. The CMS evaluation of the Vidyo tool indicates that it is not yet ready to be considered as a potential replacement for EVO. The Communications Group provides the CMS-TV (web) cha...

  3. Core Communications

    Science.gov (United States)

    Block, Greg; Ross, J. D.; Mulder, David

    2011-01-01

    The website--it is where people go to find out anything and everything about a school, college, or university. In the relatively short life of the Internet, institutional websites have moved from the periphery to center stage and become strategically integral communications and marketing tools. As the flow of information accelerates and new…

  4. Health communication

    DEFF Research Database (Denmark)

    Sørensen, Mariann B.

    communication changes from information to conversation and negotiation of a chared understanding and challenges the concept of professionalism. The success of conversations depends on the interactions and the capacity to deal with several voices in a complex context. The study discusses the opportunity...

  5. Health communication

    DEFF Research Database (Denmark)

    Sørensen, Mariann B.

    communication changes from information to conversation and negotiation of a chared understanding and challenges the concept of professionalism. The success of conversations depends on the interactions and the capacity to deal with several voices in a complex context. The study discusses the opportunity...... to develop this “skill” in health education and to refine the capacity in practice using creativity and artistic approaches....

  6. Quantum communications

    CERN Document Server

    Cariolaro, Gianfranco

    2015-01-01

    This book demonstrates that a quantum communication system using the coherent light of a laser can achieve performance orders of magnitude superior to classical optical communications Quantum Communications provides the Masters and PhD signals or communications student with a complete basics-to-applications course in using the principles of quantum mechanics to provide cutting-edge telecommunications. Assuming only knowledge of elementary probability, complex analysis and optics, the book guides its reader through the fundamentals of vector and Hilbert spaces and the necessary quantum-mechanical ideas, simply formulated in four postulates. A turn to practical matters begins with and is then developed by: ·         development of the concept of quantum decision, emphasizing the optimization of measurements to extract useful information from a quantum system; ·         general formulation of a transmitter–receiver system ·         particular treatment of the most popular quantum co...

  7. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The recently established CMS Communications Group, led by Lucas Taylor, has been busy in all three of its main are areas of responsibility: Communications Infrastructure, Information Systems, and Outreach and Education Communications Infrastructure The damage caused by the flooding of the CMS Centre@CERN on 21st December has been completely repaired and all systems are back in operation. Major repairs were made to the roofs, ceilings and one third of the floor had to be completely replaced. Throughout these works, the CMS Centre was kept operating and even hosted a major press event for first 7 TeV collisions, as described below. Incremental work behind the scenes is steadily improving the quality of the CMS communications infrastructure, particularly Webcasting, video conferencing, and meeting rooms at CERN. CERN/IT is also deploying a pilot service of a new videoconference tool called Vidyo, to assess whether it might provide an enhanced service at a lower cost, compared to the EVO tool currently in w...

  8. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The CMS Communications Group, established at the start of 2010, has been strengthening the activities in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The Communications Group has invested a lot of effort to support the operations needs of CMS. Hence, the CMS Centres where physicists work on remote CMS shifts, Data Quality Monitoring, and Data Analysis are running very smoothly. There are now 55 CMS Centres worldwide, up from just 16 at the start of CMS data-taking. The latest to join are Imperial College London, the University of Iowa, and the Università di Napoli. The CMS Centre@CERN in Meyrin, which is now full repaired after the major flooding at the beginning of the year, has been at the centre of CMS offline and computing operations, most recently hosting a large fraction of the CMS Heavy Ion community during the lead-lead run. A number of sub-detector shifts can now take pla...

  9. W频段卫星通信中正交频分复用技术的误码性能分析%Bit error rate analysis of orthogonal frequency division multiplexing technology in W-band satellite communication

    Institute of Scientific and Technical Information of China (English)

    赵乐; 宋爱民; 刘剑; 薛斌; 郭兴阳

    2015-01-01

    针对传统的卫星通信频段( C频段、Ku频段、Ka频段)应用逐渐趋于饱和的问题,研究了更高的W频段卫星通信。该频段带宽更宽,可以支持更高的数据传输速率,同等条件下天线尺寸更小并可获得更大的天线增益。正交频分复用技术具有很高的频带利用率,适合于高速数据传输,在W频段具有很好的应用前景。参照“IKNOW”项目中的链路预算,采用固态功放的Rapp模型,对OFDM技术应用在W频段卫星通信中的误码性能进行了仿真分析。仿真结果表明:在考虑功放非线性时,存在一个最佳的输入功率补偿点,使OFDM系统的误码率最低,并且发射功率越高,最佳补偿点对应的误码率越低。%Since traditional band applications ( C-band, Ku-band, Ka-band) for satellite communication will gradually tend to be saturated, the higher W-band was studied. W-band has a wider bandwidth, supports a higher data rate, acquires a smaller equipment size and a bigger antenna gain under the same conditions. Orthogonal Frequency Division Multiplexing ( OFDM) technology has a high spectrum efficiency, which makes it be suitable for high data rate transmission, so it has a good application prospect in W-band. Referring to the link budget of “IKNOW” project and using the Rapp model of solid-state power amplifier, the Bit Error Rate ( BER) of OFDM in W-band was simulated and analyzed. The simulation results show that there is a best input power backoff point which makes the BER be lowest when the nonlinear power amplifier is taken in account, and the higher the transmission power is, the lower the BER of the best input power backoff point will be.

  10. Real-time Dynamic Spectrum Management in OFDM-based High-data Rate Narrowband Power Line Communications%高速窄带OFDM电力线通信实时动态频谱分配

    Institute of Scientific and Technical Information of China (English)

    张童飞; 郭静波

    2014-01-01

    A lot of challenges have to be solved in implementation of dynamic spectrum management (DSM) such as allocation strategy and the related real time algorithm, and yet there is no such work reported publicly. Architecture of an actual orthogonal frequency division multiplexing (OFDM)-based high data rate narrowband power line communication (HDR NB PLC) system was defined and designed, and a novel strategy of DSM and the related real time algorithm suitable for the system was proposed. Under a given dimension of modulation, the algorithm partitioned the subcarriers, sorted them in power order,chose the available group, and finally determined the best modulation scheme and optimally allocated the power according to the rate maximization criteria. Comparing to the typical Hughes-Hartogs algorithm, the proposed algorithm has lower computational complexity and less signaling overhead. Comparing with conventional constant power allocation, the algorithm has a better performance of bit error rate. Simulation and experimental results verified the effectiveness and advantages of the algorithm.%动态频谱分配应用于实际电力线通信系统面临分配策略、实时算法等诸多挑战,到目前为止还未见有公开报道。定义并设计了一个实际的基于正交频分复用(orthogonal frequency division multiplexing,OFDM)的高速窄带电力线通信系统构架,并提出一种适用于该系统的动态频谱分配策略和对应的实时实现算法。该算法在任一种调制方式下将子载波进行分组,并对各个子载波组的功率进行排序,选择可用的子载波组,根据速率最大化准则确定最优的调制方式并分配功率。该算法与 Hughes-Hartogs 算法相比,具有较低的运算复杂度和较少的信令开销,与传统的等功率分配方式相比,误码性能更好。仿真结果和实验结果证明了该算法的有效性和优越性。

  11. Atmospheric transmission at ~1.55 μm for free-space optical communication

    Science.gov (United States)

    Zeller, John; Manzur, Tariq

    2010-04-01

    Free-space optics (FSO) holds the potential for high bandwidth communication, but atmospheric conditions can significantly affect the capability of a communication system to transfer information successfully. The effects of atmosphere on FSO communication and consequent optimal wavelength range for transmission are investigated through MODTRAN-based modeling of 1.55 μm transmission for multiple elevation angles in atmospheric conditions including clear maritime, desert extinction, and various levels of rain and fog. Beam transmission was also simulated for different relevant elevations for surface-to-surface and surface-to-air free-space optical communication networks. The atmospheric, free-space, and scintillation losses are investigated for optical path lengths of 2 km to determine transmit power required for successful data reception. In addition, FSO transmitter and receiver circuits were designed to optically relay an analog video signal and tested at path distances of up to 130 m. Using advanced tunable laser sources to provide illumination across wavelength ranges, particularly around the eye-safe 1.55 μm wavelength, it should be possible to overcome transmission limitations associated with adverse weather and atmospheric conditions.

  12. Communicating Science

    Science.gov (United States)

    Russell, Nicholas

    2009-10-01

    Introduction: what this book is about and why you might want to read it; Prologue: three orphans share a common paternity: professional science communication, popular journalism, and literary fiction are not as separate as they seem; Part I. Professional Science Communication: 1. Spreading the word: the endless struggle to publish professional science; 2. Walk like an Egyptian: the alien feeling of professional science writing; 3. The future's bright? Professional science communication in the age of the internet; 4. Counting the horse's teeth: professional standards in science's barter economy; 5. Separating the wheat from the chaff: peer review on trial; Part II. Science for the Public: What Science Do People Need and How Might They Get It?: 6. The Public Understanding of Science (PUS) movement and its problems; 7. Public engagement with science and technology (PEST): fine principle, difficult practice; 8. Citizen scientists? Democratic input into science policy; 9. Teaching and learning science in schools: implications for popular science communication; Part III. Popular Science Communication: The Press and Broadcasting: 10. What every scientist should know about mass media; 11. What every scientist should know about journalists; 12. The influence of new media; 13. How the media represents science; 14. How should science journalists behave?; Part IV. The Origins of Science in Cultural Context: Five Historic Dramas: 15. A terrible storm in Wittenberg: natural knowledge through sorcery and evil; 16. A terrible storm in the Mediterranean: controlling nature with white magic and religion; 17. Thieving magpies: the subtle art of false projecting; 18. Foolish virtuosi: natural philosophy emerges as a distinct discipline but many cannot take it seriously; 19. Is scientific knowledge 'true' or should it just be 'truthfully' deployed?; Part V. Science in Literature: 20. Science and the Gothic: the three big nineteenth-century monster stories; 21. Science fiction: serious

  13. Astronomy Communication

    Science.gov (United States)

    Heck, A.; Madsen, C.

    2003-07-01

    Astronomers communicate all the time, with colleagues of course, but also with managers and administrators, with decision makers and takers, with social representatives, with the news media, and with the society at large. Education is naturally part of the process. Astronomy communication must take into account several specificities: the astronomy community is rather compact and well organized world-wide; astronomy has penetrated the general public remarkably well with an extensive network of associations and organizations of aficionados all over the world. Also, as a result of the huge amount of data accumulated and by necessity for their extensive international collaborations, astronomers have pioneered the development of distributed resources, electronic communications and networks coupled to advanced methodologies and technologies, often much before they become of common world-wide usage. This book is filling up a gap in the astronomy-related literature by providing a set of chapters not only of direct interest to astronomy communication, but also well beyond it. The experts contributing to this book have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy nor in communication techniques while providing specific detailed information, as well as plenty of pointers and bibliographic elements. This book will be very useful for researchers, teachers, editors, publishers, librarians, computer scientists, sociologists of science, research planners and strategists, project managers, public-relations officers, plus those in charge of astronomy-related organizations, as well as for students aiming at a career in astronomy or related space science. Link: http://www.wkap.nl/prod/b/1-4020-1345-0

  14. Digital communication communication, multimedia, security

    CERN Document Server

    Meinel, Christoph

    2014-01-01

    The authors give a detailed summary about the fundamentals and the historical background of digital communication. This includes an overview of the encoding principles and algorithms of textual information, audio information, as well as images, graphics, and video in the Internet. Furthermore the fundamentals of computer networking, digital security and cryptography are covered. Thus, the book provides a well-founded access to communication technology of computer networks, the internet and the WWW. Numerous pictures and images, a subject-index and a detailed list of historical personalities in

  15. Protocol for Communication Networking for Formation Flying

    Science.gov (United States)

    Jennings, Esther; Okino, Clayton; Gao, Jay; Clare, Loren

    2009-01-01

    An application-layer protocol and a network architecture have been proposed for data communications among multiple autonomous spacecraft that are required to fly in a precise formation in order to perform scientific observations. The protocol could also be applied to other autonomous vehicles operating in formation, including robotic aircraft, robotic land vehicles, and robotic underwater vehicles. A group of spacecraft or other vehicles to which the protocol applies could be characterized as a precision-formation- flying (PFF) network, and each vehicle could be characterized as a node in the PFF network. In order to support precise formation flying, it would be necessary to establish a corresponding communication network, through which the vehicles could exchange position and orientation data and formation-control commands. The communication network must enable communication during early phases of a mission, when little positional knowledge is available. Particularly during early mission phases, the distances among vehicles may be so large that communication could be achieved only by relaying across multiple links. The large distances and need for omnidirectional coverage would limit communication links to operation at low bandwidth during these mission phases. Once the vehicles were in formation and distances were shorter, the communication network would be required to provide high-bandwidth, low-jitter service to support tight formation-control loops. The proposed protocol and architecture, intended to satisfy the aforementioned and other requirements, are based on a standard layered-reference-model concept. The proposed application protocol would be used in conjunction with conventional network, data-link, and physical-layer protocols. The proposed protocol includes the ubiquitous Institute of Electrical and Electronics Engineers (IEEE) 802.11 medium access control (MAC) protocol to be used in the datalink layer. In addition to its widespread and proven use in

  16. Aggregating and Communicating Uncertainty.

    Science.gov (United States)

    1980-04-01

    means for identifying and communicating uncertainty. i 12- APPENDIX A BIBLIOGRAPHY j| 1. Ajzen , Icek ; "Intuitive Theories of Events and the Effects...disregarding valid but noncausal information." (Icak Ajzen , "Intuitive Theo- ries of Events and the Effects of Base-Rate Information on Prediction...9 4i,* ,4.. -. .- S % to the criterion while disregarding valid but noncausal information." (Icak Ajzen , "Intuitive Theories of Events and the Effects

  17. Intercultural communication

    Directory of Open Access Journals (Sweden)

    Zouaoui ,Merbouh

    2009-03-01

    Full Text Available With the increase in international trade, the global economy and the globalization of English usage, more and more students are seeking to study in order to gain intercultural understanding, to achieve individual academic goals. One of the most common reasons for students wanting to study is to improve their English competence and to improve their communicative ability with other people. One effect of the globalization of the English language is a significant increase in the number of intercultural interactions. More people than ever before are involved in interactions with foreigners and communities are becoming increasingly multilingual and multicultural to mix with people from their own community rather than interact or communicate with students from other cultural backgrounds.

  18. Communications technology

    Science.gov (United States)

    Cuccia, C. Louis; Sivo, Joseph

    1986-01-01

    The technologies for optimized, i.e., state of the art, operation of satellite-based communications systems are surveyed. Features of spaceborne active repeater systems, low-noise signal amplifiers, power amplifiers, and high frequency switches are described. Design features and capabilities of various satellite antenna systems are discussed, including multiple beam, shaped reflector shaped beam, offset reflector multiple beam, and mm-wave and laser antenna systems. Attitude control systems used with the antenna systems are explored, along with multiplexers, filters, and power generation, conditioning and amplification systems. The operational significance and techniques for exploiting channel bandwidth, baseband and modulation technologies are described. Finally, interconnectivity among communications satellites by means of RF and laser links is examined, as are the roles to be played by the Space Station and future large space antenna systems.

  19. Communication Strategies

    OpenAIRE

    Strate, Simon Wolter; Loznica, Javor; Nærland, Kristoffer; Skipper, Mads Christian; Jensen, Charlotte Haagen

    2013-01-01

    This project focuses on the oil company, Shell, and their way of conducting themselves on social media sites, specifically Facebook and twitter. We establish this by using social media theory, and corporate campaign theories, and applying these to the content that Shell puts out on these particular social media sites. Furthermore, the project establishes a critical evaluation of the weight and presence of social media within modern corporate communication and issue management.

  20. Compressive Sensing in Communication Systems

    DEFF Research Database (Denmark)

    Fyhn, Karsten

    2013-01-01

    Wireless communication is omnipresent today, but this development has led to frequency spectrum becoming a limited resource. Furthermore, wireless devices become more and more energy-limited, due to the demand for continual wireless communication of higher and higher amounts of information....... The need for cheaper, smarter and more energy efficient wireless devices is greater now than ever. This thesis addresses this problem and concerns the application of the recently developed sampling theory of compressive sensing in communication systems. Compressive sensing is the merging of signal...... acquisition and compression. It allows for sampling a signal with a rate below the bound dictated by the celebrated Shannon-Nyquist sampling theorem. In some communication systems this necessary minimum sample rate, dictated by the Shannon-Nyquist sampling theorem, is so high it is at the limit of what...

  1. Holographic optical receiver front end for wireless infrared indoor communications.

    Science.gov (United States)

    Jivkova, S; Kavehrad, M

    2001-06-10

    Multispot diffuse configuration (MSDC) for indoor wireless optical communications, utilizing multibeam transmitter and angle diversity detection, is one of the most promising ways of achieving high capacities for use in high-bandwidth islands such as classrooms, hotel lobbies, shopping malls, and train stations. Typically, the optical front end of the receiver consists of an optical concentrator to increase the received optical signal power and an optical bandpass filter to reject the ambient light. Using the unique properties of holographic optical elements (HOE), we propose a novel design for the receiver optical subsystem used in MSDC. With a holographic curved mirror as an optical front end, the receiver would achieve more than an 10-dB improvement in the electrical signal-to-noise ratio compared with a bare photodetector. Features such as multifunctionality of the HOE and the receiver's small size, light weight, and low cost make the receiver front end a promising candidate for a user's portable equipment in broadband indoor wireless multimedia access.

  2. Multicarrier chaotic communications in multipath fading channels without channel estimation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shilian, E-mail: wangsl@nudt.edu.cn; Zhang, Zhili [College of Electrical Science and Engineering, National University of Defense Technology, Changsha, 410073, P R China (China)

    2015-01-15

    A multi-carrier chaotic shift keying(MC-CSK) communication scheme with low probability of interception(LPI) is proposed in this article. We apply chaotic spreading sequences in the frequency domain, mapping a different chip of a chaotic sequence to an individual orthogonal frequency division multiplexing(OFDM) subcarrier. In each block size of $M$ OFDM symbols, we use one pilot OFDM symbol inserted time-spaced in all-frequency to transmit the reference chaotic signal and use the other M-1 OFDM symbols to transmit the information-bearing signals each spreaded by the reference chaotic signal. At the receiver, we construct a differential detector after DFT and recover the information bits from the correlations between the pilot OFDM symbol and the other M-1 OFDM symbols in each block size of M. Performance analysis and computer simulations show that the MC-CSK outperforms differential chaos shift keying(DCSK) in AWGN channels with high bandwidth efficiency for the block size of M=2 and that the MC-CSK exploits effectively the frequent diversity of the multipath channel.

  3. Multicarrier chaotic communications in multipath fading channels without channel estimation

    Directory of Open Access Journals (Sweden)

    Shilian Wang

    2015-01-01

    Full Text Available A multi-carrier chaotic shift keying(MC-CSK communication scheme with low probability of interception(LPI is proposed in this article. We apply chaotic spreading sequences in the frequency domain, mapping a different chip of a chaotic sequence to an individual orthogonal frequency division multiplexing(OFDM subcarrier. In each block size of $M$ OFDM symbols, we use one pilot OFDM symbol inserted time-spaced in all-frequency to transmit the reference chaotic signal and use the other M-1 OFDM symbols to transmit the information-bearing signals each spreaded by the reference chaotic signal. At the receiver, we construct a differential detector after DFT and recover the information bits from the correlations between the pilot OFDM symbol and the other M-1 OFDM symbols in each block size of M. Performance analysis and computer simulations show that the MC-CSK outperforms differential chaos shift keying(DCSK in AWGN channels with high bandwidth efficiency for the block size of M=2 and that the MC-CSK exploits effectively the frequent diversity of the multipath channel.

  4. The Critical Care Communication project: improving fellows' communication skills.

    Science.gov (United States)

    Arnold, Robert M; Back, Anthony L; Barnato, Amber E; Prendergast, Thomas J; Emlet, Lillian L; Karpov, Irina; White, Patrick H; Nelson, Judith E

    2015-04-01

    The aim of this study was to develop an evidence-based communication skills training workshop to improve the communication skills of critical care fellows. Pulmonary and critical care fellows (N = 38) participated in a 3-day communication skills workshop between 2008 and 2010 involving brief didactic talks, faculty demonstration of skills, and faculty-supervised small group skills practice sessions with simulated families. Skills included the following: giving bad news, achieving consensus on goals of therapy, and discussing the limitations of life-sustaining treatment. Participants rated their skill levels in a pre-post survey in 11 core communication tasks using a 5-point Likert scale. Of 38 fellows, 36 (95%) completed all 3 days of the workshop. We compared pre and post scores using the Wilcoxon signed rank test. Overall, self-rated skills increased for all 11 tasks. In analyses by participant, 95% reported improvement in at least 1 skill; with improvement in a median of 10 of 11 skills. Ninety-two percent rated the course as either very good/excellent, and 80% recommended that it be mandatory for future fellows. This 3-day communication skills training program increased critical care fellows' self-reported family meeting communication skills. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Nursing the patient with complex communication needs: time as a barrier and a facilitator to successful communication in hospital.

    Science.gov (United States)

    Hemsley, Bronwyn; Balandin, Susan; Worrall, Linda

    2012-01-01

    Effective nurse-patient communication is an essential aspect of health care. Time to communicate, however, is limited and subject to workload demands. Little is known about how nurses manage this 'lack of time' when caring for patients with developmental disability and complex communication needs, who typically communicate at a slow rate. The aim of this study was to investigate nurses' expressed concepts of 'time' in stories about communicating with patients with developmental disability and complex communication needs in hospital. In 2009, 15 hospital nurses from a range of wards in two metropolitan hospitals participated in interviews about barriers to and strategies for successful communication with patients with developmental disability and complex communication needs in hospital. The data were analysed using narrative inquiry methodology and the stories verified with the participants. Nurses identified 'time' as a barrier and a facilitator to successful communication. Time as a barrier was related thematically to avoiding direct communication and preferring that family or paid carers communicated on behalf of the patient. Time as a facilitator was related to valuing communication, investing extra time, and to applying a range of adaptive communication strategies to establish successful communication. Time is perceived by nurses as both an enemy and friend for improving communication. Nurses who perceive that communication takes too long may avoid communication and miss opportunities to improve communication through increased familiarity with the person's communication methods. Those who take time to communicate narrate applying a range of strategies to achieve success in basic needs communication. © 2011 Blackwell Publishing Ltd.

  6. Covert Quantum Communication

    Science.gov (United States)

    Arrazola, Juan Miguel; Scarani, Valerio

    2016-12-01

    We extend covert communication to the quantum regime by showing that covert quantum communication is possible over optical channels with noise arising either from the environment or from the sender's lab. In particular, we show that sequences of qubits can be transmitted covertly by using both a single photon and a coherent state encoding. We study the possibility of performing covert quantum key distribution (QKD) and show that positive key rates and covertness can be achieved simultaneously. Covert communication requires a secret key between the sender and receiver, which raises the problem of how this key can be regenerated covertly. We show that covert QKD consumes more secret bits than it can generate and propose instead a hybrid protocol for covert key regeneration that uses pseudorandom number generators (PRNGs) together with covert QKD to regenerate secret keys. The security of the new key is guaranteed by QKD while the security of the covert communication is at least as strong as the security of the PRNG.

  7. Optimization Design for Virtual Prototype of Variable Rate Fertilization Based on Embedded Communication System%基于嵌入式通信系统的变量施肥虚拟样机优化设计

    Institute of Scientific and Technical Information of China (English)

    葛蓁; 熊琼; 邓明华; 汪小志; 鲍秀兰

    2016-01-01

    为了达到液态施肥机高速作业的目标,提出了一种新的施肥机施肥变量控制的方法,该方法主要采用Pro/E和ADMAS 联合仿真的方式对机构的机械运动轨迹进行验证,采用模糊控制和二阶差分算法降低施肥量的误差,使用PLC 实现施肥数据的处理和通信。为了验证该方法的有效性和可靠性,应用三维造型设计软件 Pro/E ,绘制机构各零部件模型并装配,通过改变保存文件的类型实现 Pro/E 与 ADAMS 数据交换,在 ADAMS 中建立机构虚拟样机和运动学仿真,得到了施肥机虚拟样机的运动轨迹。最后,通过PLC 嵌入式通信系统的优化,得到了虚拟样机施肥量随速度变化曲线,并将优化前后的施肥准确度和效率进行了对比。通过对比发现:使用 PLC嵌入式系统优化后的施肥机,施肥的精确性得到了明显的改善,且施肥效率较高,为变量施肥控制的研究提供了理论参考。%In order to achieve high speed operation of liquid fertilizer machine goal , it proposes a new method of variable control fertilization , the method mainly by the joint simulation of Pro/E and ADMAS mode of mechanical motion trajecto-ry of the mechanism is verified ,by using fuzzy control and two order differential algorithm to reduce the low fertilization a-mount of error , the realization of the use of PLC processing fertilization and communication data .In order to verify the validity of the method and reliability , application of 3D modeling design software Pro/E, the parts and assembly drawing mechanism model , through the type change save file to realize Pro/E and ADAMS data exchange , to establish the mecha-nism of virtual prototype and kinematics simulation in ADAMS , get the trajectory of the virtual prototype and fertilizing machine .Finally , through the optimization of the PLC embedded communication system , obtained the change curve of virtual prototype with the speed

  8. Underwater optical wireless communication network

    Science.gov (United States)

    Arnon, Shlomi

    2010-01-01

    The growing need for underwater observation and subsea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, biogeochemical, evolutionary, and ecological changes in the sea, ocean, and lake environments, and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. Models are presented for three kinds of optical wireless communication links: (a) a line-of-sight link, (b) a modulating retroreflector link, and (c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered light it was possible to mitigate this decrease in some cases. It is concluded from the analysis that a high-data-rate underwater optical wireless network is a feasible solution for emerging applications such as UUV-to-UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

  9. Intercultural Communication Ethics and Communication Competence%Intercultural Communication Ethics and Communication Competence

    Institute of Scientific and Technical Information of China (English)

    时婷洁

    2012-01-01

    This paper investigates intercultural communication ethics is a vital element to promote intercultural communication competence. Firstly, it defines the concept of intercultural communication ethics; Secondly, it illustrates the relation between ethics and the key point of intercultural communication competence; and finally addresses how intercultural communication ethics can improve intercultural communication competence.

  10. Communication theory

    CERN Document Server

    Goldie, Charles M

    1991-01-01

    This book is an introduction, for mathematics students, to the theories of information and codes. They are usually treated separately but, as both address the problem of communication through noisy channels (albeit from different directions), the authors have been able to exploit the connection to give a reasonably self-contained treatment, relating the probabilistic and algebraic viewpoints. The style is discursive and, as befits the subject, plenty of examples and exercises are provided. Some examples and exercises are provided. Some examples of computer codes are given to provide concrete illustrations of abstract ideas.

  11. Interdisciplinary Communication

    Directory of Open Access Journals (Sweden)

    Nagib Callaos

    2013-12-01

    Full Text Available Communication is fundamental in scientific practice and an integral part of academic work. The practice of communication cannot be neglected by those who are trying to advance scientific research. Effective means should continuously be identified in order to open channels of communication within and among disciplines, among scientists and between scientists and the general public.[1]The increasing importance of interdisciplinary communication has been pointed out by an increasing number of researchers and scholars, as well as in conferences and roundtables on the subject. Some authors even estimate that "interdisciplinary study represents the future of the university."[2] Since interdisciplinary study is "the most underthought critical, pedagogical and institutional concept in modern academy"[3] it is important to think and reflect, and even do some research, on this concept or notion. Research and practice based reflections with regards to this issue are important especially because the increasing complexity and proliferation of scientific research is generating countless specialties, sub-specialties and sub-sub-specialties, with their respective special languages; which were "created for discrete local areas of research based upon the disconnected branches of science."[4] On the other hand, scientific, technical and societal problems are requiring multi- or inter-disciplinary consideration. Consequently, interdisciplinary communication channels are being needed with urgency, and scientific research should be integrated, not just in the context of its discipline, but also in the context of related disciplines. Much more reflection and research should be done on this issue. Research on adequate research integration and communication is urgently required, i.e. meta-research efforts should be done in order to relate research results in an adequate and more useful way. This meta-research effort might be done in the context of each particular

  12. Biomonitoring with Wireless Communications

    Energy Technology Data Exchange (ETDEWEB)

    Budinger, Thomas F.

    2003-03-01

    This review is divided into three sections: technologies for monitoring physiological parameters; biosensors for chemical assays and wireless communications technologies including image transmissions. Applications range from monitoring high risk patients for heart, respiratory activity and falls to sensing levels of physical activity in military, rescue, and sports personnel. The range of measurements include, heart rate, pulse wave form, respiratory rate, blood oxygen, tissue pCO2, exhaled carbon dioxide and physical activity. Other feasible measurements will employ miniature chemical laboratories on silicon or plastic chips. The measurements can be extended to clinical chemical assays ranging from common blood assays to protein or specialized protein measurements (e.g., troponin, creatine, and cytokines such as TNF and IL6). Though the feasibility of using wireless technology to communicate vital signs has been demonstrated 32 years ago (1) it has been only recently that practical and portable devices and communications net works have become generally available for inexpensive deployment of comfortable and affordable devices and systems.

  13. 超高速毫米波无线局域网通信系统性能分析%Performance Analysis for Ultra-high Rate Millimeter Wave Wireless Local Area Network Communication Systems

    Institute of Scientific and Technical Information of China (English)

    陈鹏; 缪小龙; 何世文; 黄永明; 杨绿溪

    2015-01-01

    针对中国毫米波频段(45GHz),制定下一代 IEEE 802.11 aj 无线局域网(Wireless Local Area Network, WLAN)协议标准通信系统的物理层结构及发射机发送方式,研究了一种新的适用于该标准的循环移位分集(Cy-clic Shift Diversity,CSD)方案,该方案在不增加接收机额外复杂度的前提下能够获得较好的性能。同时,本文对通信系统在各种调制和编码方式(Modulation and Coding Scheme,MCS)下的性能进行了仿真和评估。结果表明,在将系统发射功率控制在20dB 时,采用码率为1/2的16-QAM调制方式可以在保证误帧率性能的同时获得较高的吞吐率。%IEEE 802.1 1 aj is a standard of next generation wireless local area network(WLAN)for millimeter wave band (45GHz)of China.A structure of physical layer and a structure of transmitter are designed for communication system.This paper made a research on a new scheme of cyclic shift diversity for IEEE 802.1 1 aj standard.The scheme can achieve good performance without additional effort at the receiver.In addition,this paper made an analysis on the performance of all modulation and coding schemes.In conclusion,in order to limit the transmitting power at 20dB,the 1 6-QAMmodulation of rate-1 /2 could achieve high throughput ensuring the PER performance at the same time.

  14. 湍流大气光通信系统误码率分析与实验研究%Analysis and Experimental Research on Bit Error Rate for Free-Space Optical Communication Systems through Turbulent Atmosphere

    Institute of Scientific and Technical Information of China (English)

    李菲; 吴毅; 侯再红

    2012-01-01

    自由空间光通信(FSO)系统的性能由于受大气湍流影响会产生剧烈波动.根据系统和大气参数评估系统差错性能的研究具有现实意义.以大气湍流信道和光电探测两个模型为基础,建立了FSO系统差错性能的数学仿真模型,提出了湍流条件下系统误码率计算公式.对仿真结果与弱湍流条件下获得的实验数据进行了比较,并依据此模型对光强起伏和背景噪声等因素的影响进行仿真.仿真结果表明,基于该模型的仿真结果与实验数据一致,光强起伏是引起系统性能波动的主要因素,最优判决阈值需根据实际大气条件进行调整.该模型可有效评估湍流条件下FSO系统性能,并为相关理论研究提供参考.%Performance of free-space optical communication (FSO) system fluctuates greatly due to influence by atmospheric turbulence. Research about evaluating system error performance according to parameters of system and atmosphere is a subject of current interest. Based on both optical turbulence channel and photoelectric detection model, a ma thematic simulation model of error performance for FSO system is established, and an expression of bit error rate for FSO system through turbulent atmosphere is proposed. Results of simulation are compared with experimental data obtained under weak turbulence condition and the model is used to characterize factors in turbulence, such as intensity fluctuation and background noise, etc. Simulation results are shown to be consistent with experimental data, intensity fluctuation is a chief factor of system performance fluctuation, and optimized threshold should be adjusted according to pratical atmosphere. The presented model can lead to an efficient performance evaluation and provide reference to correlative theoretical researches.

  15. Wireless communication technologies in distribution automation

    Energy Technology Data Exchange (ETDEWEB)

    Takala, J. [VTT Energy, Espoo (Finland)

    1996-12-31

    The project examines four different wireless communication technologies: GSM short message service, NMT data calls, packet radio network, Autonet (Actionet) status message service. The targets for communication include: energy measurement, especially in the de-regulated electricity market, secondary sub-station control, fault indicators. The research concentrates on the usability of different communication technologies for different purposes. Data about response times, error rates, retry times, communication delays, costs etc. will be collected for each communication technology and comparative results will be obtained. Some field experiments and demonstrations will be made in energy measurement and distribution network remote control. The project is divided in four tasks. Each task is described briefly

  16. Terabit Wireless Communication Challenges

    Science.gov (United States)

    Hwu, Shian U.

    2012-01-01

    This presentation briefly discusses a research effort on Terabit Wireless communication systems for possible space applications. Recently, terahertz (THz) technology (300-3000 GHz frequency) has attracted a great deal of interest from academia and industry. This is due to a number of interesting features of THz waves, including the nearly unlimited bandwidths available, and the non-ionizing radiation nature which does not damage human tissues and DNA with minimum health threat. Also, as millimeter-wave communication systems mature, the focus of research is, naturally, moving to the THz range. Many scientists regard THz as the last great frontier of the electromagnetic spectrum, but finding new applications outside the traditional niches of radio astronomy, Earth and planetary remote sensing, and molecular spectroscopy particularly in biomedical imaging and wireless communications has been relatively slow. Radiologists find this area of study so attractive because t-rays are non-ionizing, which suggests no harm is done to tissue or DNA. They also offer the possibility of performing spectroscopic measurements over a very wide frequency range, and can even capture signatures from liquids and solids. According to Shannon theory, the broad bandwidth of the THz frequency bands can be used for terabit-per-second (Tb/s) wireless communication systems. This enables several new applications, such as cell phones with 360 degrees autostereoscopic displays, optic-fiber replacement, and wireless Tb/s file transferring. Although THz technology could satisfy the demand for an extremely high data rate, a number of technical challenges need to be overcome before its development. This presentation provides an overview the state-of-the- art in THz wireless communication and the technical challenges for an emerging application in Terabit wireless systems. The main issue for THz wave propagation is the high atmospheric attenuation, which is dominated by water vapor absorption in the THz

  17. A data pump for communication

    Science.gov (United States)

    Kang, Myong H.; Moskowitz, Ira S.

    1995-09-01

    As computer systems become more open and interconnected, the need for reliable and secure communication also increases. In this paper, we introduce a communication device, the Pump, that balances the requirements of reliability and security. The Pump provides acknowledgements (ACK's) to the message source to insure reliability. These ACK's are also used to regulate the source to prevent the Pump's buffer from becoming/staying full. This is desirable because once the buffer is filled there exists a huge covert communication channel. The Pump controls the input rate from the source by attempting to slave the input rate to the service rate through the randomized ACK back to the source. An analysis of the covert channel is also presented. The purpose of the covert channel analysis is to provide guidelines for the designer of the Pump to choose appropriate design parameters (e.g., size of buffer) dependent upon the analysis presented in this paper and system requirements.

  18. Wireless communication with chaos.

    Science.gov (United States)

    Ren, Hai-Peng; Baptista, Murilo S; Grebogi, Celso

    2013-05-03

    The modern world fully relies on wireless communication. Because of intrinsic physical constraints of the wireless physical media (multipath, damping, and filtering), signals carrying information are strongly modified, preventing information from being transmitted with a high bit rate. We show that, though a chaotic signal is strongly modified by the wireless physical media, its Lyapunov exponents remain unaltered, suggesting that the information transmitted is not modified by the channel. For some particular chaotic signals, we have indeed proved that the dynamic description of both the transmitted and the received signals is identical and shown that the capacity of the chaos-based wireless channel is unaffected by the multipath propagation of the physical media. These physical properties of chaotic signals warrant an effective chaos-based wireless communication system.

  19. An Effective Queue Management Scheme for Data Communication

    Directory of Open Access Journals (Sweden)

    Sheela Thavasi

    2011-01-01

    Full Text Available Problem statement: The growth in the needs of Internet applications that transmit massive amount of data has led to the emergence of Effective Queue Management. Approach: Queues were used to smooth spikes in incoming packet rates and to allow the router sufficient time for packet processing. When the waiting time is less a better queue management is ensured thereby resulting in increased flow in the queue. When the incoming packet rate was higher than the router's outgoing packet rate, the queue size was increased, eventually exceeding the available buffer space. With respect to TCP’s RED queue management, the problem was that the buffer size was reduced to half and the packets were dropped abruptly. The congestion was detected early and the packets were dropped. The merit may be that congestion was detected early but the adverse effect was loss of packets. Results: The sender had to retransmit causing delay onto the network. This caused adverse effects on the network performance. In proposed system queue was extended whenever the number of packets present in the queue exceeds queue threshold. Packet drops were insignificantly even during network congestion. When the queue was continuously extended and if there was steady inflow of high volume of data, packet drop ratio was insignificant. Conclusions: Thus by the adoption of the proposed work, network throughput rose considerably thereby enabling effective data transfer. So it exhibits high bandwidth utilization, good throughput and processing time.

  20. Creativity in clinical communication: from communication skills to skilled communication.

    Science.gov (United States)

    Salmon, Peter; Young, Bridget

    2011-03-01

    Medical Education 2011: 45: 217-226 Objectives  The view that training in communication skills produces skilled communication is sometimes criticised by those who argue that communication is individual and intuitive. We therefore examine the validity of the concept of communication as a skill and identify alternative principles to underpin future development of this field. Methods  We critically examine research evidence about the nature of clinical communication, and draw from theory and evidence concerning education and evaluation, particularly in creative disciplines. Results  Skilled communication cannot be fully described using the concept of communication skills. Attempts to do so risk constraining and distorting pedagogical development in communication. Current education practice often masks the difficulties with the concept by introducing subjectivity into the definition and assessment of skills. As all clinical situations differ to some extent, clinical communication is inherently creative. Because it is rarely possible to attribute specific effects to specific elements of communication, communication needs to be taught and evaluated holistically. Conclusions  For communication teaching to be pedagogically and clinically valid in supporting the inherent creativity of clinical communication, it will need to draw from education theory and practice that have been developed in explicitly creative disciplines.

  1. The Use of Post-Purchase Communication to Reduce Dissonance and Improve Direct Marketing Effectiveness.

    Science.gov (United States)

    Milliman, Ronald E.; Decker, Phillip J.

    1990-01-01

    Demonstrates the use and potentially positive effects of postpurchase communication on order refund requests and reorder rates. Finds that dissonance was effectively reduced through postpurchase communication. (MG)

  2. Communicative Musicality

    DEFF Research Database (Denmark)

    Holck, Ulla

    2010-01-01

    how rhythmic organization between mother and infant allow both partners to sustain a coordinated relationship in time (Mazokopaki & Kuguimutzakis), and that vowel sounds expressed in musical ways engage emotions and serve as a vehicle for enculturation as to how to use feelings to share activities...... forms of music, dance, poetry or ceremony; whether they are the universal narratives of a mother and her baby quietly conversing with one another; whether it is the wordless emotional and motivational narrative that sits beneath a conversation between two or more adults or between a teacher and a class....... In the coordination of practical tasks, a shared, intuitively communicated understanding is necessary for success. It is our common musicality that makes it possible for us to share time meaningfully together, in its emotional richness and its structural holding, and for us to participate with anticipation...

  3. OFDM systems for wireless communications

    CERN Document Server

    Narasimhamurthy, Adarsh

    2010-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution.This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is

  4. Application of 4G Mobile Communication Technology in the Emergency Communication of Nuclear Power%4G移动通信技术在核电应急通信中的应用

    Institute of Scientific and Technical Information of China (English)

    陆帆; 景弋

    2015-01-01

    Relying on the existing nuclear power system communication resources, this paper puts forward a kind of time-sharing long-term evolution (TD-LTE) nuclear emergency communication system, through the establishment of cover area emergency special td-scdma LTE network, for the nuclear power emergency command center offers unexpect-ed emergency field audio and video data, as well as the temporary channels of nuclear power communication fault recov-ery with high bandwidth.The construction of the emergency system improves the ability of nuclear power system commu-nication to deal with emergency events, to ensure safe and reliable operation of the nuclear power system.%依托现有核电系统的通信资源,提出了一种基于分时长期演进(TD-LTE)的核电应急通信系统,通过建立覆盖应急区域的专用TD-LTE网络,为核电应急指挥中心提供突发应急现场音视频数据,同时也为核电通信故障恢复提供高带宽的临时通道。该应急系统的建设提高了核电系统通信应对应急事件的能力,保障核电系统的安全可靠运行。

  5. Web Applications for Patient Communication.

    Science.gov (United States)

    Lewis, Kristopher; Reicher, Murray A

    2016-12-01

    Communication between imaging professionals and patients can help achieve many goals, including improved patient understanding of imaging-related diagnostic and treatment options, better compliance with appropriate imaging screening procedures, and improved efficiency of service. The explosive growth of out-of-pocket consumer spending on health care has heightened health care shopping, thus making patient communication an important goal of any imaging practice or health care organization. Furthermore, the Merit-Based Incentive Payment System introduced by CMS will publicly disclose physicians' quality ratings, which are in part dependent on patient engagement. The authors summarize the rationale for web communication with patients, the range of content that should be considered, and the technology options. The aim is to help imaging providers develop organized patient communication strategic and implementation plans. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  6. Robots and communication

    CERN Document Server

    Sandry, E

    2015-01-01

    This book explores communication between humans and robots. Using a range of communication theories, it highlights how each theory provides a different perspective on the communication that occurs. The analysis of human interactions with a variety of forms of robot suggests new ways to perceive what communication, and being a communicator, entails.

  7. Using Codes to Communicate

    Institute of Scientific and Technical Information of China (English)

    李媛

    2005-01-01

    @@ When we communicate, we want our messages and meanings to be understood. The difficulty is that much of what we do when we communicate comes from our subjective culture. In communications, when we share culture, we share meanings,and when we communicate, we exchange meanings. When we prepare to communicate with strangers from other cultures, we usually begin by learning a language.

  8. Business Communication Strategies

    OpenAIRE

    Lavinia Hulea

    2005-01-01

    General communication processes rely on messages implying contents, communication channels, a receiver and clear objectives. Once accepting the importance of defining objectives, three strategies, narrative, implicative, and decisional, seem to be specific for most business communications. While narrative business communications convey information with a view of simply transmitting information and depend on accuracy, complexity, and clarity, implicative business communications convey informat...

  9. Hazard Communication Standard

    Energy Technology Data Exchange (ETDEWEB)

    Sichak, S.

    1991-01-01

    The current rate of technological advances has brought with it an overwhelming increase in the usage of chemicals in the workplace and in the home. Coupled to this increase has been a heightened awareness in the potential for acute and chronic injuries attributable to chemical insults. The Hazard Communication Standard has been introduced with the desired goal of reducing workplace exposures to hazardous substances and thereby achieving a corresponding reduction in adverse health effects. It was created and proclaimed by the US Department of Labor and regulated by the Occupational Safety and Health Administration. 1 tab.

  10. Airborne wireless communication systems, airborne communication methods, and communication methods

    Science.gov (United States)

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  11. Atmospheric Laser Communication.

    Science.gov (United States)

    Fischer(, Kenneth W.; Witiw, Michael R.; Baars+, Jeffrey A.; Oke, T. R.

    2004-05-01

    Atmospheric laser communication, often referred to as free-space optics (FSO) or free-space laser (FSL) communication, is similar to fiber optic cable in terms of carrier wavelength and bandwidth capability, but data are transmitted directly through the atmosphere via laser beams over paths from a few meters to 4 km or longer. FSL uses lasers in the near-infrared spectrum, typically at wavelengths of 850 or 1550 nm. Given these wavelengths, atmospheric attenuation must be considered, and an adequate margin of optical power (dB) must exist to support high system availability (the percentage of time that an FSL link is in operation, typically 99.9%). A visual range of 100 m can attenuate a laser beam at a rate of nearly 130 dB km-1. For short links (rain, and snow frequently become issues. To address these issues, long-term climate data are analyzed to determine the frequency of occurrence of low visibilities and low-cloud ceilings. To estimate availability at a site of interest, adjustments to airport climate data are made to accommodate differences in altitude, geography, and the effects of the urban heat island. In sum, communication via FSL is a feasible alternative to fiber optic cable when atmospheric conditions are considered and properly analyzed.(Current affiliation: The Boeing Company, Seattle, Washington+Current affiliation: Department of Atmospheric Sciences, University of Washington, Seattle, Washington

  12. Architecture and governance for communication services

    CERN Document Server

    Crespi , Noel

    2013-01-01

    Communication services are evolving at an unprecedented rate. No longer limited to interpersonal vocal communication, they now integrate functions such as address books, content sharing and messaging. The emergence of social networks - which may also include these features - is an important element of this transformation. Content services are becoming flagship services themselves, and are sometimes paired up with conversation services. The boundaries between different services are becoming less and less distinct. This book meets the need for a better understanding of communication services,

  13. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin is particularly busy at the moment, hosting about 50 physicists taking part in the heavy-ion data-taking and analysis. Three new CMS meeting room will be equipped for videoconferencing in early 2012: 40/5B-08, 42/R-031, and 28/S-029. The CMS-TV service showing LHC Page 1, CMS Page 1, etc. (http://cmsdoc.cern.ch/cmscc/projector/index.jsp) is now also available for mobile devices: http://cern.ch/mcmstv. Figure 12: Screenshots of CMS-TV for mobile devices Information Systems CMS has a new web site: (http://cern.ch/cms) using a modern web Content Management System to ensure content and links are managed and updated easily and coherently. It covers all CMS sub-projects and groups, replacing the iCMS internal pages. It also incorporates the existing CMS public web site (http:/...

  14. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2012-01-01

      Outreach and Education We are fortunate that our research has captured the public imagination, even though this inevitably puts us under the global media spotlight, as we saw with the Higgs seminar at CERN in December, which had 110,000 distinct webcast viewers. The media interest was huge with 71 media organisations registering to come to CERN to cover the Higgs seminar, which was followed by a press briefing with the DG and Spokespersons. This event resulted in about 2,000 generally positive stories in the global media. For this seminar, the CMS Communications Group prepared up-to-date news and public material, including links to the CMS results, animations and event displays [http://cern.ch/go/Ch8thttp://cern.ch/go/Ch8t]. There were 44,000 page-views on the CMS public website, with the Higgs news article being by far the most popular item. CMS event displays from iSpy are fast becoming the iconic media images, featuring on numerous major news outlets (BBC, CNN, MSN...) as well as in the sci...

  15. DIORAMA Communications

    Energy Technology Data Exchange (ETDEWEB)

    Galassi, Mark C. [Los Alamos National Laboratory

    2016-05-24

    Diorama is written as a collection of modules that can run in separate threads or in separate processes. This defines a clear interface between the modules and also allows concurrent processing of different parts of the pipeline. The pipeline is determined by a description in a scenario file[Norman and Tornga, 2012, Tornga and Norman, 2014]. The scenario manager parses the XML scenario and sets up the sequence of modules which will generate an event, propagate the signal to a set of sensors, and then run processing modules on the results provided by those sensor simulations. During a run a variety of “observer” and “processor” modules can be invoked to do interim analysis of results. Observers do not modify the simulation results, while processors may affect the final result. At the end of a run results are collated and final reports are put out. A detailed description of the scenario file and how it puts together a simulation are given in [Tornga and Norman, 2014]. The processing pipeline and how to program it with the Diorama API is described in Tornga et al. [2015] and Tornga and Wakeford [2015]. In this report I describe the communications infrastructure that is used.

  16. Evaluating Internal Communication: The ICA Communication Audit.

    Science.gov (United States)

    Goldhaber, Gerald M.

    1978-01-01

    The ICA Communication Audit is described in detail as an effective measurement procedure that can help an academic institution to evaluate its internal communication system. Tools, computer programs, analysis, and feedback procedures are described and illustrated. (JMF)

  17. Optical Wireless Communications and Autonomous Beam Control Moving User Terminal

    OpenAIRE

    Tangtrongbenchasil, Charoen; HAMADA, Yoichi; KATO, Toshihiro; Nonaka, Koji

    2007-01-01

    Optical wireless communications is a research topic of extreme interest since it offers high data rate (Gbps data rate), security, and RF interference immunity. However, optical wireless communications places severe restrictions on the communications paths; they must be direct beam connections. To increase the number of users and link robustness, optical wireless communications must be able to operate even when obstacles are placed between transmitters and receivers, so optical micro-cell (OM...

  18. Communication and Alzheimer's

    Science.gov (United States)

    ... We will not sell or share your name. Communication and Alzheimer's Tweet Bookmark this page | Email | Print ... stage Communication in the late stage Changes in communication In addition to changes in the brain caused ...

  19. What Is Communicative?

    Science.gov (United States)

    Harmer, Jeremy

    1982-01-01

    Examines word "communicative" and nature of communication and suggests it should not be applied to a methodology. Draws distinction between "communicative" and "noncommunicative" activities while claims each has its place in balanced approach to language teaching. (Author/BK)

  20. Communication and Social Responsibility.

    Science.gov (United States)

    Bennett, W. Lance

    1985-01-01

    Proposes a code for a new communication consciousness that would keep language sensitive and accountable to human experience. Focuses on mass political communication and the tendency toward systematic negative communication inherent in news pronouncements. (PD)

  1. What Is Good Communication?

    Science.gov (United States)

    Spitzberg, Brian H.

    2000-01-01

    Explores issues entailed in defining good communication including multiple reasonable criteria, competency bias, and communication as a function of context, locus, and abstraction. Claims good communication is a subjective evaluation and not subject to being codified in reductionist models. (NH)

  2. 央行沟通行为与市场利率波动的相关性研究--基于中国银行业同业拆放利率Shibor的数据检验%The Correlation Research on Central Bank Communication Behavior and Market Interest Rate Fluctuations:Evidence from Shibor

    Institute of Scientific and Technical Information of China (English)

    马理; 黄帆帆; 孙芳芳

    2013-01-01

    近年来,在常规的货币政策之外,各国央行越来越重视其沟通行为在经济调控中的作用。但是央行沟通行为的传导路径与传导效果尚有待深入探讨,本文运用MVGARCH与Probit模型,基于中国银行业的同业拆放利率Shibor的数据,对央行沟通行为的有效性进行了研究。结果表明:央行沟通能够显著影响市场利率波动;口头沟通侧重于创造信息,影响利率水平的变化;书面沟通更侧重于减少噪音,降低利率的波动程度。中央银行应根据经济环境选择恰当的沟通方式,更有效地发挥央行沟通行为的作用。%In recent years, central bank communication behavior has also been paid more and more atten-tion by the central banks besides the traditional monetary policy tools , however its conduction path and con-duction effect remains to be further discussed .Based on Shibor , this paper studies the effectiveness of central bank communication behavior by using multivariate GARCH model and Probit model .The results show that China ’ s central bank communications can significantly affect the market interest rate fluctuations .Specifical-ly, oral communications focused more on creating information , which change the level of interest rates , while written communications tended to be rather effective in reducing noise , which lower the volatility of interest rates.Appropriate ways should be chosen according to different economic environments in order to enable the most effective use of central bank communication behavior .

  3. Wireless Communication over Dispersive Channels

    NARCIS (Netherlands)

    Fang, K.

    2010-01-01

    Broadband wireless communication systems require high transmission rates, where the bandwidth of the transmitted signal is larger than the channel coherence bandwidth. This gives rise to time dispersion of the transmitted symbols or frequency-selectivity with different frequency components exhibitin

  4. Active photonic sensor communication cable for field application of optical data and power transmission

    Science.gov (United States)

    Suthau, Eike; Rieske, Ralf; Zerna, Thomas

    2014-10-01

    Omitting electrically conducting wires for sensor communication and power supply promises protection for sensor systems and monitored structures against lightning or high voltages, prevention of explosion hazards, and reduction of susceptibility to tampering. The ability to photonically power remote systems opens up the full range of electrical sensors. Power-over-fiber is an attractive option in electromagnetically sensitive environments, particularly for longterm, maintenance-free applications. It can deliver uninterrupted power sufficient for elaborate sensors, data processing or even actuators alongside continuous high speed data communication for remote sensor application. This paper proposes an active photonic sensor communication system, which combines the advantages of optical data links in terms of immunity to electromagnetic interference (EMI), high bandwidth, hardiness against tampering or eavesdropping, and low cable weight with the robustness one has come to expect from industrial or military electrical connectors. An application specific integrated circuit (ASIC) is presented that implements a closed-loop regulation of the sensor power supply to guarantee continuous, reliable data communications while maintaining a highly efficient, adaptive sensor supply scheme. It is demonstrated that the resulting novel photonic sensor communication cable can handle sensors and actuators differing orders of magnitude with respect to power consumption. The miniaturization of the electro-optical converters and driving electronics is as important to the presented development as the energy efficiency of the detached, optically powered sensor node. For this reason, a novel photonic packaging technology based on wafer-level assembly of the laser power converters by means of passive alignment will be disclosed in this paper.

  5. Development of Laser Beam Transmission Strategies for Future Ground-to-Space Optical Communications

    Science.gov (United States)

    Wilson, Keith E.; Kovalik, Joseph M.; Biswas, Abhijit; Roberts, William T.

    2007-01-01

    Optical communications is a key technology to meet the bandwidth expansion required in the global information grid. High bandwidth bi-directional links between sub-orbital platforms and ground and space terminals can provide a seamless interconnectivity for rapid return of critical data to analysts. The JPL Optical Communications Telescope Laboratory (OCTL) is located in Wrightwood California at an altitude of 2.2.km. This 200 sq-m facility houses a state-of- the-art 1-m telescope and is used to develop operational strategies for ground-to-space laser beam propagation that include safe beam transmission through navigable air space, adaptive optics correction and multi-beam scintillation mitigation, and line of sight optical attenuation monitoring. JPL has received authorization from international satellite owners to transmit laser beams to more than twenty retro-reflecting satellites. This paper presents recent progress in the development of these operational strategies tested by narrow laser beam transmissions from the OCTL to retro-reflecting satellites. We present experimental results and compare our measurements with predicted performance for a variety of atmospheric conditions.

  6. Communication analysis for feedback control of civil infrastructure using cochlea-inspired sensing nodes

    Science.gov (United States)

    Peckens, Courtney A.; Cook, Ireana; Lynch, Jerome P.

    2016-04-01

    Wireless sensor networks (WSNs) have emerged as a reliable, low-cost alternative to the traditional wired sensing paradigm. While such networks have made significant progress in the field of structural monitoring, significantly less development has occurred for feedback control applications. Previous work in WSNs for feedback control has highlighted many of the challenges of using this technology including latency in the wireless communication channel and computational inundation at the individual sensing nodes. This work seeks to overcome some of those challenges by drawing inspiration from the real-time sensing and control techniques employed by the biological central nervous system and in particular the mammalian cochlea. A novel bio-inspired wireless sensor node was developed that employs analog filtering techniques to perform time-frequency decomposition of a sensor signal, thus encompassing the functionality of the cochlea. The node then utilizes asynchronous sampling of the filtered signal to compress the signal prior to communication. This bio-inspired sensing architecture is extended to a feedback control application in order to overcome the traditional challenges currently faced by wireless control. In doing this, however, the network experiences high bandwidths of low-significance information exchange between nodes, resulting in some lost data. This study considers the impact of this lost data on the control capabilities of the bio-inspired control architecture and finds that it does not significantly impact the effectiveness of control.

  7. 5G- FUTURE GENERATION TECHNOLOGIES OF WIRELESS COMMUNICATION “REVOLUTION 2020”

    Directory of Open Access Journals (Sweden)

    Manjurul H. Khan

    2015-05-01

    Full Text Available This paper is focused on the specification of future generations of wireless mobile communication networks. The paper throws light on the evolution and development of various generations of mobile wireless technology along with their significance and advantages of one over the other. 5G technologies will change the way most high-bandwidth users access their phones. With 5G people will experience a level of call volume and data transmission never experienced before. 5G technology is offering the services in different fields like Documentation, supporting electronic transactions (e-Payments, e-transactions etc. As the customer becomes more and more aware of the mobile phone technology, he or she will look for a decent package all together, including all the advanced features a cellular phone can have. The 5G design is based on user-centric mobile environment with many wireless and mobile technologies on the ground. WWWW that is World Wide Wireless Web allows complete wireless communication with almost no limitation, Multi-Media Newspapers, watch TV programs with the clarity as to that of an HD TV.

  8. Intervehicle Communication Research – Communication Scenarios

    Directory of Open Access Journals (Sweden)

    Šarūnas Stanaitis

    2011-03-01

    Full Text Available Recently intervehicle communications are attracting much attention from industry and academia. Upcoming standard for intervehicle communication IEEE 802.11p, known as Wireless Access in Vehicular Environments (WAVE, is still in its draft stage, but already coming into final standardization phase. Problematic, regarding mobile WAVE nodes, are described in several articles, simulations prepared and experiments done. But most of these works do not consider possible maximal communication load. This paper presents intervehicle communication scenario in respect to radio communications, mobility and other aspects of vehicular environments.Article in English

  9. High Speed Peltier Calorimeter for the Calibration of High Bandwidth Power Measurement Equipment

    CERN Document Server

    Frost, Damien F

    2015-01-01

    Accurate power measurements of electronic components operating at high frequencies are vital in determining where power losses occur in a system such as a power converter. Such power measurements must be carried out with equipment that can accurately measure real power at high frequency. We present the design of a high speed calorimeter to address this requirement, capable of reaching a steady state in less than 10 minutes. The system uses Peltier thermoelectric coolers to remove heat generated in a load resistance, and was calibrated against known real power measurements using an artificial neural network. A dead zone controller was used to achieve stable power measurements. The calibration was validated and shown to have an absolute accuracy of +/-8 mW (95% confidence interval) for measurements of real power from 0.1 to 5 W.

  10. Efficient route to high-bandwidth nanoscale magnetometry using single spins in diamond.

    Science.gov (United States)

    Puentes, Graciana; Waldherr, Gerald; Neumann, Philipp; Balasubramanian, Gopalakrishnan; Wrachtrup, Jörg

    2014-04-14

    Nitrogen-vacancy (NV) center in diamond is a promising quantum metrology tool finding applications across disciplines. The spin sensor measures magnetic fields, electric fields and temperature with nano-scale precision and is fully operable under ambient conditions. Moreover, it achieves precision scaling inversely with total measurement time σB ∝ 1/T (Heisenberg scaling) rather than as the inverse of the square root of T, with σB = √T the Shot-Noise limit. This scaling can be achieved by means of phase estimation algorithms (PEAs), in combination with single-shot read-out. Despite their accuracy, the range of applicability of PEAs is limited to sensing single frequencies with negligible temporal fluctuations. Nuclear Magnetic Resonance (NMR) signals from molecules often contain multifrequency components and sensing them using PEA is ruled out. Here we propose an alternative method for precision magnetometry in frequency multiplexed signals via compressive sensing (CS) techniques focusing on nanoscale NMR. We show that CS can provide for precision scaling approximately as σB ≈ 1/T, as well as for a 5-fold increase in sensitivity over dynamic-range gain, in addition to reducing the total number of resources required. We illustrate our method by taking model solid-state spectra of Glycine acquired under Magic Angle Spinning conditions.

  11. Multi-input and binary reproducible, high bandwidth floating point adder in a collective network

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dong; Eisley, Noel A.; Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2016-11-15

    To add floating point numbers in a parallel computing system, a collective logic device receives the floating point numbers from computing nodes. The collective logic devices converts the floating point numbers to integer numbers. The collective logic device adds the integer numbers and generating a summation of the integer numbers. The collective logic device converts the summation to a floating point number. The collective logic device performs the receiving, the converting the floating point numbers, the adding, the generating and the converting the summation in one pass. One pass indicates that the computing nodes send inputs only once to the collective logic device and receive outputs only once from the collective logic device.

  12. 3-D readout-electronics packaging for high-bandwidth massively paralleled imager

    Science.gov (United States)

    Kwiatkowski, Kris; Lyke, James

    2007-12-18

    Dense, massively parallel signal processing electronics are co-packaged behind associated sensor pixels. Microchips containing a linear or bilinear arrangement of photo-sensors, together with associated complex electronics, are integrated into a simple 3-D structure (a "mirror cube"). An array of photo-sensitive cells are disposed on a stacked CMOS chip's surface at a 45.degree. angle from light reflecting mirror surfaces formed on a neighboring CMOS chip surface. Image processing electronics are held within the stacked CMOS chip layers. Electrical connections couple each of said stacked CMOS chip layers and a distribution grid, the connections for distributing power and signals to components associated with each stacked CSMO chip layer.

  13. A High Bandwidth Non-Destructive Method for Characterizing Simple Media

    Science.gov (United States)

    2012-03-22

    Havrilla (Chairman) Dr. Michael Saville (Member) Zr.{ ~ L, 20((... Date Date 21 fe-h 2otŖ_ Date AFIT/GE/ENG/12-39 iv Abstract The relative...OF PAGES 74 19a. NAME OF RESPONSIBLE PERSON Dr. Michael Havrilla a. REPORT U b. ABSTRACT U c. THIS PAGE U 19b. TELEPHONE NUMBER

  14. A Low Power High Bandwidth Four Quadrant Analog Multiplier in 32 NM CNFET Technology

    Directory of Open Access Journals (Sweden)

    Vitrag Sheth

    2012-05-01

    Full Text Available Carbon Nanotube Field Effect Transistor (CNFET is a promising new technology that overcomes several limitations of traditional silicon integrated circuit technology. In recent years, the potential of CNFET for analog circuit applications has been explored. This paper proposes a novel four quadrant analog multiplier design using CNFETs. The simulation based on 32nm CNFET technology shows that the proposed multiplier has very low harmonic distortion (<0.45%, large input range (±400mV, large bandwidth (~50GHz and low power consumption (~247µW, while operating at a supply voltage of ±0.9V.

  15. A 750MHz and a 8GHz High Bandwidth Digital FFT Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The scope of this project is to to develop a wide bandwidth, low power, and compact single board digital Fast Fourier Transform spectrometer (FFTS) optimized for the...

  16. High-Bandwidth Photon-Counting Detectors with Enhanced Near-Infrared Response Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Long-range optical telecommunications (LROT) impose challenging requirements on detector array sensitivity at 1064nm and arrays timing bandwidth. Large photonic...

  17. High-bandwidth squeezed light at 1550 nm from a compact monolithic PPKTP cavity

    CERN Document Server

    Ast, Stefan; Schnabel, Roman

    2013-01-01

    We report the generation of squeezed vacuum states of light at 1550 nm with a broadband quantum noise reduction of up to 4.8 dB ranging from 5 MHz to 1.2 GHz sideband frequency. We used a custom-designed 2.6 mm long biconvex periodically-poled potassium titanyl phosphate (PPKTP) crystal. It featured reflectively coated end surfaces, 2.26 GHz of linewidth and generated the squeezing via optical parametric amplification. Two homodyne detectors with different quantum efficiencies and bandwidths were used to characterize the non-classical noise suppression. We measured squeezing values of up to 4.8 dB from 5 to 100 MHz and up to 3 dB from 100 MHz to 1.2 GHz. The squeezed vacuum measurements were limited by detection loss. We propose an improved detection scheme to measure up to 10 dB squeezing over 1 GHz. Our results of GHz bandwidth squeezed light generation provide new prospects for high-speed quantum key distribution.

  18. Development of Advanced Low Emission Injectors and High-Bandwidth Fuel Flow Modulation Valves

    Science.gov (United States)

    Mansour, Adel

    2015-01-01

    Parker Hannifin Corporation developed the 3-Zone fuel nozzle for NASA's Environmentally Responsible Aviation Program to meet NASAs target of 75 LTO NOx reduction from CAEP6 regulation. The nozzle concept was envisioned as a drop-in replacement for currently used fuel nozzle stem, and is built up from laminates to provide energetic mixing suitable for lean direct injection mode at high combustor pressure. A high frequency fuel valve was also developed to provide fuel modulation for the pilot injector. Final testing result shows the LTO NOx level falling just shy of NASAs goal at 31.

  19. Application of Advanced Electromagnetic Arrays to High Efficiency, High Bandwidth, Redundant Linear Actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed SBIR effort will employ a systems approach to develop motor/controller/screw element systems adequate for demanding launch thrust vector control and...

  20. Multi-input and binary reproducible, high bandwidth floating point adder in a collective network

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dong; Eisley, Noel A; Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-03-10

    To add floating point numbers in a parallel computing system, a collective logic device receives the floating point numbers from computing nodes. The collective logic devices converts the floating point numbers to integer numbers. The collective logic device adds the integer numbers and generating a summation of the integer numbers. The collective logic device converts the summation to a floating point number. The collective logic device performs the receiving, the converting the floating point numbers, the adding, the generating and the converting the summation in one pass. One pass indicates that the computing nodes send inputs only once to the collective logic device and receive outputs only once from the collective logic device.

  1. Full phase stabilization of a Yb:fiber femtosecond frequency comb via high-bandwidth transducers

    NARCIS (Netherlands)

    Benko, C.; Ruehl, A.; Martin, M.J.; Eikema, K.S.E.; Fermann, M.E.; Hartl, I.; Ye, J.

    2012-01-01

    We present full phase stabilization of an amplified Yb:fiber femtosecond frequency comb using an intracavity electro-optic modulator and an acousto-optic modulator. These transducers provide high servo bandwidths of 580 kHz and 250 kHz for f(rep) and f(ceo), producing a robust and low phase noise fi

  2. Ultra-low Noise, High Bandwidth, 1550nm HgCdTe APD Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Voxtel Inc. proposes to optimize the design of a large area, 1.55?m sensitive HgCdTe avalanche photodiode (APD) that achieves high gain with nearly no excess noise....

  3. High-bandwidth multimode self-sensing in bimodal atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Michael G. Ruppert

    2016-02-01

    Full Text Available Using standard microelectromechanical system (MEMS processes to coat a microcantilever with a piezoelectric layer results in a versatile transducer with inherent self-sensing capabilities. For applications in multifrequency atomic force microscopy (MF-AFM, we illustrate that a single piezoelectric layer can be simultaneously used for multimode excitation and detection of the cantilever deflection. This is achieved by a charge sensor with a bandwidth of 10 MHz and dual feedthrough cancellation to recover the resonant modes that are heavily buried in feedthrough originating from the piezoelectric capacitance. The setup enables the omission of the commonly used piezoelectric stack actuator and optical beam deflection sensor, alleviating limitations due to distorted frequency responses and instrumentation cost, respectively. The proposed method benefits from a more than two orders of magnitude increase in deflection to strain sensitivity on the fifth eigenmode leading to a remarkable signal-to-noise ratio. Experimental results using bimodal AFM imaging on a two component polymer sample validate that the self-sensing scheme can therefore be used to provide both the feedback signal, for topography imaging on the fundamental mode, and phase imaging on the higher eigenmode.

  4. High-Bandwidth Dynamic Full-Field Profilometry for Nano-Scale Characterization of MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L-C [Graduate Institute of Automation Technology, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd., Taipei, 106, Taiwan (China); Huang, Y-T [Graduate Institute of Automation Technology, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd., Taipei, 106, Taiwan (China); Chang, P-B [Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd., Taipei, 106, Taiwan (China)

    2006-10-15

    The article describes an innovative optical interferometric methodology to delivery dynamic surface profilometry with a measurement bandwidth up to 10MHz or higher and a vertical resolution up to 1 nm. Previous work using stroboscopic microscopic interferometry for dynamic characterization of micro (opto)electromechanical systems (M(O)EMS) has been limited in measurement bandwidth mainly within a couple of MHz. For high resonant mode analysis, the stroboscopic light pulse is insufficiently short to capture the moving fringes from dynamic motion of the detected structure. In view of this need, a microscopic prototype based on white-light stroboscopic interferometry with an innovative light superposition strategy was developed to achieve dynamic full-field profilometry with a high measurement bandwidth up to 10MHz or higher. The system primarily consists of an optical microscope, on which a Mirau interferometric objective embedded with a piezoelectric vertical translator, a high-power LED light module with dual operation modes and light synchronizing electronics unit are integrated. A micro cantilever beam used in AFM was measured to verify the system capability in accurate characterisation of dynamic behaviours of the device. The full-field seventh-mode vibration at a vibratory frequency of 3.7MHz can be fully characterized and nano-scale vertical measurement resolution as well as tens micrometers of vertical measurement range can be performed.

  5. Carbon nanotubes as electromechanical resonators: Single-electron tunneling, nonlinearity, and high-bandwidth readout

    NARCIS (Netherlands)

    Meerwaldt, H.B.

    2013-01-01

    A carbon nanotube (CNT) is a remarkable material and can be thought of as a single-atom thick cylinder of carbon atoms capped of with a semisphere. This is called a single-walled CNT and, depending on how the cylinder is rolled up, CNTs are either semiconducting or metallic. A CNT is made into a mec

  6. Carbon nanotubes as electromechanical resonators: Single-electron tunneling, nonlinearity, and high-bandwidth readout

    OpenAIRE

    Meerwaldt, H. B.

    2013-01-01

    A carbon nanotube (CNT) is a remarkable material and can be thought of as a single-atom thick cylinder of carbon atoms capped of with a semisphere. This is called a single-walled CNT and, depending on how the cylinder is rolled up, CNTs are either semiconducting or metallic. A CNT is made into a mechanical resonator by suspending it between two electrodes. The CNT is driven into motion electrostatically, and the mechanical motion is detected using the current flowing through the CNT. We use t...

  7. Application of Advanced Electromagnetic Arrays to High Efficiency, High Bandwidth, Redundant Linear Actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a need to develop electromechanical actuators to improve performance beyond that of hydraulic devices currently being used in numerous aerospace and...

  8. A HIGH BANDWIDTH BIPOLAR POWER SUPPLY FOR THE FAST CORRECTORS IN THE APS UPGRADE*

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ju; Sprau, Gary

    2017-06-25

    The APS Upgrade of a multi-bend achromat (MBA) storage ring requires a fast bipolar power supply for the fast correction magnets. The key performance requirement of the power supply includes a small-signal bandwidth of 10 kHz for the output current. This requirement presents a challenge to the design because of the high inductance of the magnet load and a limited input DC voltage. A prototype DC/DC power supply utilizing a MOSFET H-bridge circuit with a 500 kHz PWM has been developed and tested successfully. The prototype achieved a 10-kHz bandwidth with less than 3-dB attenuation for a signal 0.5% of the maximum operating current of 15 amperes. This paper presents the design of the power circuit, the PWM method, the control loop, and the test results.

  9. Development and Implementation of High Bandwidth Pulsed Microactuators for Sub and Supersonic Applications

    Science.gov (United States)

    2012-06-15

    Fluids, Vol. 10, No. 8, 1998, pp 2026-2036. 39. Stanek, M. J., Raman, G., Kibens, V., Ross, J. A., Odedra, J., and Peto , J. W., “Control of Cavity...Vol. 10, No. 8, 1998, pp 2026-2036. 26 18. Stanek, M. J., Raman, G., Kibens, V., Ross, J. A., Odedra, J., and Peto , J. W., “Control of

  10. Carbon nanotubes as electromechanical resonators: Single-electron tunneling, nonlinearity, and high-bandwidth readout

    NARCIS (Netherlands)

    Meerwaldt, H.B.

    2013-01-01

    A carbon nanotube (CNT) is a remarkable material and can be thought of as a single-atom thick cylinder of carbon atoms capped of with a semisphere. This is called a single-walled CNT and, depending on how the cylinder is rolled up, CNTs are either semiconducting or metallic. A CNT is made into a

  11. High Bandwidth Zero Voltage Injection Method for Sensorless Control of PMSM

    DEFF Research Database (Denmark)

    Ge, Xie; Lu, Kaiyuan; Kumar, Dwivedi Sanjeet

    2014-01-01

    High frequency signal injection is widely used in PMSM sensorless control system for low speed operations. The conventional voltage injection method often needs filters to obtain particular harmonic component in order to estimate the rotor position; or it requires several voltage pulses to be inj...... in a fast current regulation performance. Injection of zero voltage also minimizes the inverter voltage error effects caused by the dead-time.......High frequency signal injection is widely used in PMSM sensorless control system for low speed operations. The conventional voltage injection method often needs filters to obtain particular harmonic component in order to estimate the rotor position; or it requires several voltage pulses...... to be injected before the position may be estimated. In this paper, a single pulse zero voltage injection method is proposed. The rotor position is directly estimated from the current ripple at half of the switching frequency. No machine parameters are needed and using of filters is avoided. This results...

  12. Soviet satellite communications science and technology

    Energy Technology Data Exchange (ETDEWEB)

    Birch, J.N.; Campanella, S.J.; Gordon, G.D.; McElroy, D.R.; Pritchard, W.L.; Stamminger, R.

    1991-08-01

    This is a report by six US scientists and engineers concerning the current state of the art and projections of future Soviet satellite communications technologies. The panel members are experts in satellite stabilization, spacecraft environments, space power generation, launch systems, spacecraft communications sciences and technologies, onboard processing, ground stations, and other technologies that impact communications. The panel assessed the Soviet ability to support high-data-rate space missions at 128 Mbps by evaluating current and projected Soviet satellite communications technologies. A variety of space missions were considered, including Earth-to-Earth communications via satellites in geostationary or highly elliptical orbits, those missions that require space-to-Earth communications via a direct path and those missions that require space-to-Earth communications via a relay satellite. Soviet satellite communications capability, in most cases, is 10 years behind that of the United States and other industrialized nations. However, based upon an analysis of communications links needed to support these missions using current Soviet capabilities, it is well within the current Soviet technology to support certain space missions outlined above at rates of 128 Mbps or higher, although published literature clearly shows that the Soviet Union has not exceeded 60 Mbps in its current space system. These analyses are necessary but not sufficient to determine mission data rates, and other technologies such as onboard processing and storage could limit the mission data rate well below that which could actually be supported via the communications links. Presently, the Soviet Union appears to be content with data rates in the low-Earth-orbit relay via geostationary mode of 12 Mbps. This limit is a direct result of power amplifier limits, spacecraft antenna size, and the utilization of K{sub u}-band frequencies. 91 refs., 16 figs., 15 tabs.

  13. Central Bank Communication and the Yield Curve

    DEFF Research Database (Denmark)

    Leombroni, Matteo; Vedolin, Andrea; Venter, Gyuri

    We extract novel measures of ECB target rate announcement and communications shocks using high frequency data on money market rates and study their impact on yields of Eurozone countries. We find that (i) target rate shocks have little effect on changes in bond yields of Eurozone countries, while...... communication shocks have a significant impact, with intermediate maturities being affected the most; (ii) positive (negative) communication shocks significantly lower (raise) the yield spread between the peripheral and core countries; (iii) this cross-sectional difference arises after the 2008 financial crises......; (iv) higher credit risk amplifies the effect of communication shocks, and more so for core countries. We rationalize these findings in a parsimonious international term structure model in which interest rates are determined by the interaction between risk-averse arbitrageurs and reaching...

  14. Quantum network communication -- the butterfly and beyond

    CERN Document Server

    Leung, D; Winter, A; Leung, Debbie; Oppenheim, Jonathan; Winter, Andreas

    2006-01-01

    We study the communication of quantum information in networks of (directed) quantum channels. We consider the asymptotic rates of high fidelity quantum communication between specific sender-receiver pairs, and obtain outer and inner bounds of the achievable rate regions. All four scenarios of classical communication assistance (none, forward, backward, and two-way) are considered. For networks in which (1) the receivers are information sinks, (2) the maximum distance from senders to receivers is small, and without further constraints on the networks (such as the number of intermediate parties), we prove that rerouting of quantum information is optimal. Furthermore, the optimal use of the free assisting classical communication is simply to modify the directions of quantum channels in the network. Consequently, the achievable rate regions are given by counting edge avoiding paths, and precise achievable rate regions in all four assisting scenarios can be obtained. These complete solutions apply to many networks...

  15. Reconfigurable/Reprogrammable Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The future of reconfigurable/reprogrammable transceivers with !Y 1 Gbps transmission and reception data rates for future NASA space communications applications will...

  16. Patients' communication with doctors: a randomized control study of a brief patient communication intervention.

    Science.gov (United States)

    Talen, Mary R; Muller-Held, Christine F; Eshleman, Kate Grampp; Stephens, Lorraine

    2011-09-01

    In research on doctor-patient communication, the patient role in the communication process has received little attention. The dynamic interactions of shared decision making and partnership styles which involve active patient communication are becoming a growing area of focus in doctor-patient communication. However, patients rarely know what makes "good communication" with medical providers and even fewer have received coaching in this type of communication. In this study, 180 patients were randomly assigned to either an intervention group using a written communication tool to facilitate doctor-patient communication or to standard care. The goal of this intervention was to assist patients in becoming more effective communicators with their physicians. The physicians and patients both rated the quality of the communication after the office visit based on the patients' knowledge of their health concerns, organizational skills and questions, and attitudes of ownership and partnership. The results supported that patients in the intervention group had significantly better communication with their doctors than patients in the standard care condition. Physicians also rated patients who were in the intervention group as having better overall communication and organizational skills, and a more positive attitude during the office visit. This study supports that helping patients structure their communication using a written format can facilitate doctor-patient communication. Patients can become more adept at describing their health concerns, organizing their needs and questions, and being proactive, which can have a positive effect on the quality of the doctor-patient communication during outpatient office visits. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

  17. Physical layer simulator for undersea free-space laser communications

    Science.gov (United States)

    Dalgleish, Fraser R.; Shirron, Joseph J.; Rashkin, David; Giddings, Thomas E.; Vuorenkoski Dalgleish, Anni K.; Cardei, Ionut; Ouyang, Bing; Caimi, Frank M.; Cardei, Mihaela

    2014-05-01

    High bandwidth (10 to 100 Mbps), real-time data networking in the subsea environment using free-space lasers has a potentially high impact as an enabling technology for a variety of future subsea operations in the areas of distributed sensing, real-time wireless data transfer, control of unmanned undersea vehicles, and other submerged assets. However, the development and testing of laser networking equipment in the undersea environment are expensive and time consuming, and there is a clear need for a network simulation framework that will allow researchers to evaluate the performance of alternate optical and electronic configurations under realistic operational and environmental constraints. The overall objective of the work reported in this paper was to develop and validate such a simulation framework, which consists of (1) a time-dependent radiative transfer model to accurately predict the channel impulse characteristics for alternate system designs over a range of geometries and optical properties and (2) digital modulation and demodulation blocks which accurately simulate both laser source and receiver noise characteristics in order to generate time domain bit stream samples that can be digitally demodulated to predict the resulting bit error rate of the simulated link.

  18. Central Bank Communication and the Yield Curve

    DEFF Research Database (Denmark)

    Leombroni, Matteo; Vedolin, Andrea; Venter, Gyuri

    We extract novel measures of ECB target rate announcement and communications shocks using high frequency data on money market rates and study their impact on yields of Eurozone countries. We find that (i) target rate shocks have little effect on changes in bond yields of Eurozone countries, while...

  19. Internet-Based Communication

    Science.gov (United States)

    Gernsbacher, Morton Ann

    2014-01-01

    Google the question, "How is the Internet changing the way we communicate?," and you will find no shortage of opinions, or fears, about the Internet altering the way we communicate. Although the Internet is not necessarily making communication briefer (neither is the Internet making communication less formal), the Internet is manifesting…

  20. Intercultural Communication and ELT

    Institute of Scientific and Technical Information of China (English)

    许玲

    2013-01-01

    Intercultural communication seeks to understand how people from different countries or cultures act, communicate and perceive the world around them. To develop students’culture awareness and intercultural communication skills have been incorporated in ELT curriculum. This paper will focus on culture awareness, cultural disparities and cross-cultural communica-tion in ELT context.

  1. Language and Communication.

    Science.gov (United States)

    Richards, Jack C., Ed.; Schmidt, Richard W., Ed.

    A collection of essays addresses the connection between the study of communication and its sociocultural contexts and the approach to second language teaching based on the concept of communicative competence. Essays include: "From Communicative Competence to Communicative Language Pedagogy" (Michael Canale); "The Domain of Pragmatics" (Bruce…

  2. Overview of communications programs

    Science.gov (United States)

    Depaula, Ramon P.

    1991-01-01

    The objective of the communications program is to advance critical areas of enabling and enhancing communication technologies that support commercial needs, science, and exploration missions for the 1990's and beyond. The technology program consists of research and technology development in the following areas: RF technology; digital technology; optical communications; mobile communications; and systems integration, test, and evaluation.

  3. Animal and Human Communication.

    Science.gov (United States)

    Rummel, Lynda

    Several misconceptions regarding the status of human communication systems relative to the systems of other animals are discussed in this paper. Arguments are offered supporting the expansion of the communication discipline to include the study of the communication systems of other species. The "communicative continuity" view which ranks…

  4. Implementation of Communicative Approach

    Science.gov (United States)

    Jabeen, Shazi Shah

    2014-01-01

    In the contemporary age of high professional requirements such as excellent communicative skills, the need for successful learning of communicative skills of English language suggests communicative ability to be the goal of language teaching. In other words, to teach English language using communicative approach becomes essential. Studies to…

  5. Internet-Based Communication

    Science.gov (United States)

    Gernsbacher, Morton Ann

    2014-01-01

    Google the question, "How is the Internet changing the way we communicate?," and you will find no shortage of opinions, or fears, about the Internet altering the way we communicate. Although the Internet is not necessarily making communication briefer (neither is the Internet making communication less formal), the Internet is manifesting…

  6. Non-Verbal Communication.

    Science.gov (United States)

    Hinde, R. A., Ed.

    This inter-disciplinary approach to the subject of non-verbal communication includes essays by linguists, zoologists, psychologists, anthropologists and a drama critic. It begins with a theoretical analysis of communicative processes written from the perspective of a communications engineer, compares vocal communication in animals and man, and…

  7. Infrared Free Space Communication - The Autonomous Testing of Free Space Infrared Communication

    Science.gov (United States)

    Heldman, Christopher

    2017-01-01

    Fiber optics has been a winning player in the game of high-speed communication and data transfer in cable connections. Yet, in free space RF has been the repeated choice of communication medium of the space industry. Investigating the benefits of free space optical communication over radio frequency is worthwhile. An increase in science data rate return capabilities could occur if optical communication is implemented. Optical communication systems also provide efficiencies in power, mass, and volume over RF systems1. Optical communication systems have been demonstrated from a satellite in orbit with the moon to earth, and resulted in the highest data rates ever seen through space (622Mbps)2. Because of these benefits, optical communication is far superior to RF. The HiDRA (High Data Rate Architecture) project is researching Passive Misalignment Mitigation of Dynamic Free Apace Optical Communication Links. The goal of this effort is to enable gigabit per second transmission of data in short range dynamic links (less than 100 meters). In practice this would enhance data rates between sites on the International Space Station with minimal size, weight, and power requirements. This paper will focus on an autonomous code and a hardware setup that will be used to fulfill the next step in the research being conducted. The free space optical communications pointing downfalls will be investigated. This was achieved by creating 5 python programs and a top-level code to automate this test.

  8. FOMC communication and emerging equity markets

    OpenAIRE

    Hayo, Bernd; Ali M. Kutan; Neuenkirch, Matthias

    2009-01-01

    Using a GARCH model, we study the effects of Federal Funds target rate changes and FOMC communication on emerging equity market returns and volatility over the period 1998–2006. First, both types of news have a significant impact on market returns. Second, target rate changes are more important than informal communication. Third, the occurrence of monetary policy reports lowers price volatility. Finally, American emerging markets react more to U.S. news than non-American markets.

  9. Optical Communication on SmallSats - Enabling the Next Era in Space Science (a Keck Institute for Space Studies Workshop)

    Science.gov (United States)

    Grefenstette, Brian

    2017-08-01

    Small satellites (science from space-borne platforms. A number of scientific CubeSats have been recently launched or are under development, including some bound for interplanetary space. Recent miniaturization of technology for high-precision pointing, high efficiency solar power, high-powered on-board processing, and scientific detectors provide the capability for groundbreaking, focused science from these resource-limited spacecraft. Similar innovations in both radio frequency and optical/laser communications are poised to increase telemetry bandwidth to a gigabit per second (Gb/s) or more. This enhancement can allow real-time, global science measurements and/or ultra-high fidelity (resolution, cadence, etc.) observations from tens or hundreds of Earth-orbiting satellites, or permit high-bandwidth, direct-to-earth communications for (inter)planetary missions. Here we present the results of a recent Keck Institue for Space Science workshop that brought together scientists and engineers from academia and industry to showcase the breakthrough science enabled by optical communications on small satellites for future missions.

  10. On Communication Models

    Institute of Scientific and Technical Information of China (English)

    蒋娜; 谢有琪

    2012-01-01

    With the development of human society, the social hub enlarges beyond one community to the extent that the world is deemed as a community as a whole. Communication, therefore, plays an increasingly important role in our daily life. As a consequence, communication model or the definition of which is not so much a definition as a guide in communication. However, some existed communication models are not as practical as it was. This paper tries to make an overall contrast among three communication models Coded Model, Gable Communication Model and Ostensive Inferential Model, to see how they assist people to comprehend verbal and non -verbal communication.

  11. Communications device identification methods, communications methods, wireless communications readers, wireless communications systems, and articles of manufacture

    Science.gov (United States)

    Steele, Kerry D [Kennewick, WA; Anderson, Gordon A [Benton City, WA; Gilbert, Ronald W [Morgan Hill, CA

    2011-02-01

    Communications device identification methods, communications methods, wireless communications readers, wireless communications systems, and articles of manufacture are described. In one aspect, a communications device identification method includes providing identification information regarding a group of wireless identification devices within a wireless communications range of a reader, using the provided identification information, selecting one of a plurality of different search procedures for identifying unidentified ones of the wireless identification devices within the wireless communications range, and identifying at least some of the unidentified ones of the wireless identification devices using the selected one of the search procedures.

  12. Organizational Communication: Communication and Motivation in the Workplace

    Directory of Open Access Journals (Sweden)

    Sari Ramadanty

    2016-01-01

    nonverbal communication, interpersonal communication leadership and communication climate have a significant role to form employee motivation. Nonverbal communication has slightly strong role in shaping the positive motivation to employee. The role includes body communication, facial communication and eye communication. Interpersonal communication leader is based on the satisfaction level of information between management and employees. Management and transparency in openness in downward communication under the form of information from superiors are by listening the communication between supervisors and employees are running smoothly.

  13. I-centric Communications

    CERN Document Server

    Arbanowski, S; Steglich, S; Popescu-Zeletin, R

    2001-01-01

    During the last years, a variety of concepts for service integration and corresponding systems have gained momentum. On the one hand, they aim for the interworking and integration of classical telecommunications and data communications services. On the other hand, they are focusing on universal service access from a variety of end user systems. Looking at humans' communication behavior and communication space, it is obvious that human beings interact frequently in a set of contexts in their environment (communication space). Following this view, we want to build communication systems on the analysis of the individual communication spaces. The results are communication systems adapted to the specific demands of each individual. The authors introduce I-centric Communication Systems, an approach to design communication systems which adapt to the individual communication space and individual environment and situation. In this context "I" means I, or individual, "Centric" means adaptable to I requirements and a ce...

  14. 47 CFR 64.1801 - Geographic rate averaging and rate integration.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Geographic rate averaging and rate integration. 64.1801 Section 64.1801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... Rate Integration § 64.1801 Geographic rate averaging and rate integration. (a) The rates charged...

  15. Communication skills of anesthesiologists: An Indian perspective.

    Science.gov (United States)

    Kumar, Mritunjay; Dash, Hari Har; Chawla, Rajiv

    2013-07-01

    Communication failure is a risk factor for mishaps and complaints, which can be reduced by effective communication between operating room team members and patients. To conduct a survey among anesthesiologists regarding communications skills and related issues like stress in case of communication failure, need for training, music in operation theater, and language barrier at their work place. We conducted a survey among anesthesiologists coming for a neuroanesthesia conference in India (n = 110) in February 2011 by questionnaire sent by e-mail to them. The response rate was 61.8% (68/110). Majority (95.5%) of the respondents agreed that good verbal communication leads to better patient outcome, better handling of crisis and is important between surgeons and anesthesiologists (98.5%). A total of 86% of the anesthesiologists felt that failure of communication caused stress to them. The idea of communication by e-mail or phone text messages instead of verbal communications was discouraged by 65.2%. A total of 82% of respondents felt that training of communication skills should be mandatory for all medical personnel and 77.6% were interested in participating in such course. Language barrier at work place was seen as hurdle by 62.7% of the respondents. A total of 80% of respondents felt that playing music in operating theater is appropriate. Results of the survey highlight the need for effective communication in the operating room between team members and need for formal training to improve it.

  16. Wireless communication technology NFC

    OpenAIRE

    MÁROVÁ, Kateřina

    2014-01-01

    Aim of this bachelor thesis is to handle the issue of new wireless communication technology NFC (Near Field Communication) including a comparison of advantages and disadvantages of NFC with other wireless technologies (Bluetooth, Wi-Fi, etc.). NFC is a technology for wireless communications between different electronic devices, one of which is typically a mobile phone. Near Field Communication allows wireless communication at very short distance by approaching or enclosing two devices and can...

  17. Silence in Intercultural communication

    Institute of Scientific and Technical Information of China (English)

    Guo Jun

    2012-01-01

    In communication, most of people's attention focuses on verbal communication, nonverbal language as a means of exchange is often ignored. However, nonverbal language continues sending signals, and most of these signals are sent to conversational partners unconsciously. So correct understanding of these signals will help people improve effectiveness of communication. This article will focus on silence, a major part of nonverbal communication, exploring its communicative functions and cultural differences.

  18. Newnes communications technology handbook

    CERN Document Server

    Lewis, Geoff

    1994-01-01

    Newnes Communications Technology Handbook provides a discussion on different topics relevant to communications technology. The book is comprised of 39 chapters that tackle a wide variety of concern in communications technology. The coverage of the text includes technologies, such as analog digital communications systems, radio frequency receiver, and satellite systems. The book also discusses some methods and techniques used in communications technology, including mixer signal processing, modulation and demodulation, and spread spectrum techniques. The text will be of great use to engineers, t

  19. Improving Employee Communications

    Energy Technology Data Exchange (ETDEWEB)

    A. R. Pomplun; B. J. Kelley; B. L. Schrader; R. C. Christma; R. H. Tucker

    1999-01-01

    This report summarizes the findings and recommendation of the Sandia/California Site Communications Team based on activities during FY98. The important conclusions are that effective communications are everyone's business; careful planning and execution are required for effective communications; and communication planning can be described in steps easily understood by everyone. Included in this report is a quick reference (toolkit) for communication planning and implementation.

  20. Trends in communications satellites

    CERN Document Server

    Curtin, Denis J

    1979-01-01

    Trends in Communications Satellites offers a comprehensive look at trends and advances in satellite communications, including experimental ones such as NASA satellites and those jointly developed by France and Germany. The economic aspects of communications satellites are also examined. This book consists of 16 chapters and begins with a discussion on the fundamentals of electrical communications and their application to space communications, including spacecraft, earth stations, and orbit and wavelength utilization. The next section demonstrates how successful commercial satellite communicati

  1. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  2. Nurse-Patient Communication Interactions in the Intensive Care Unit

    Science.gov (United States)

    Happ, Mary Beth; Garrett, Kathryn; Thomas, Dana DiVirgilio; Tate, Judith; George, Elisabeth; Houze, Martin; Radtke, Jill; Sereika, Susan

    2011-01-01

    Background The inability to speak during critical illness is a source of distress for patients, yet nurse-patient communication in the intensive care unit has not been systematically studied or measured. Objectives To describe communication interactions, methods, and assistive techniques between nurses and nonspeaking critically ill patients in the intensive care unit. Methods Descriptive observational study of the nonintervention/usual care cohort from a larger clinical trial of nurse-patient communication in a medical and a cardiothoracic surgical intensive care unit. Videorecorded interactions between 10 randomly selected nurses (5 per unit) and a convenience sample of 30 critically ill adults (15 per unit) who were awake, responsive, and unable to speak because of respiratory tract intubation were rated for frequency, success, quality, communication methods, and assistive communication techniques. Patients self-rated ease of communication. Results Nurses initiated most (86.2%) of the communication exchanges. Mean rate of completed communication exchange was 2.62 exchanges per minute. The most common positive nurse act was making eye contact with the patient. Although communication exchanges were generally (>70%) successful, more than one-third (37.7%) of communications about pain were unsuccessful. Patients rated 40% of the communication sessions with nurses as somewhat difficult to extremely difficult. Assistive communication strategies were uncommon, with little to no use of assistive communication materials (eg, writing supplies, alphabet or word boards). Conclusions Study results highlight specific areas for improvement in communication between nurses and nonspeaking patients in the intensive care unit, particularly in communication about pain and in the use of assistive communication strategies and communication materials. PMID:21362711

  3. Vocoders in mobile satellite communications

    Science.gov (United States)

    Kriedte, W.; Canavesio, F.; dal Degan, N.; Pirani, G.; Rusina, F.; Usai, P.

    Owing to the power constraints that characterize onboard transmission sections, low-bit-rate coders seem suitable for speech communications inside mobile satellite systems. Vocoders that operate at rates below 4.8 kbit/s could therefore be a desirable solution for this application, providing also the redundancy that must be added to cope with the channel error rate. After reviewing the mobile-satellite-systems aspects, the paper outlines the features of two different types of vocoders that are likely to be employed, and the relevant methods of assessing their performances. Finally, some results from computer simulations of the speech transmission systems are reported.

  4. Pseudo-communication vs Quasi-communication

    Directory of Open Access Journals (Sweden)

    Елена Константиновна Черничкина

    2016-12-01

    Full Text Available The article is devoted to the analysis of such specific forms of human interaction as quasi- and pseudo-communication. The authors specify the terms which sometimes are used interchangeably. The aim of the conducted research is to find out and demonstrate existing differences and similarities of these communicative phenomena on the basis of theoretical and empirical analysis of the research material in the Russian and English languages. The authors describe communicative features of these phenomena and consider the reasons for such forms of communication and their increased use at present. The research material is represented fiction extracts, film scripts, jokes, print media, a collection of oral speech records both in Russian and English. The authors make use of the following research methods: definitional analysis (to define the terminology of the research, the method of linguistic observation and introspection (to select the communicative situations, the descriptive-analytical method and the method of comparative analysis (to identify similarities and differences of the target phenomena, and the conversational analysis method (to view productivity and effectiveness of a dialogue, etc. The classification of possible forms of their existence in different discourses is suggested. The authors assume that both pseudo- and quasi-communication are characterized as fictitious forms of human interaction with some noticeable violation of the basic communicative model. Pseudo-communication suffers from the discrepancy of the meaning of a coded and decoded message. The authors put forward the main parameters of scientific classification of it as follows: adequate understanding, intentionality, and the stage of communicative action where the failure takes place. At the same time they stress the necessity to distinguish the cases of pseudo talks from phatic and indirect communication. Quasi-communcation is marked by the lack of a real partner and hence

  5. Communication: Rate coefficients of the H + CH{sub 4} → H{sub 2} + CH{sub 3} reaction from ring polymer molecular dynamics on a highly accurate potential energy surface

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qingyong, E-mail: mengqingyong@dicp.ac.cn; Chen, Jun, E-mail: chenjun@dicp.ac.cn; Zhang, Dong H., E-mail: zhangdh@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China)

    2015-09-14

    The ring polymer molecular dynamics (RPMD) calculations are performed to calculate rate constants for the title reaction on the recently constructed potential energy surface based on permutation invariant polynomial (PIP) neural-network (NN) fitting [J. Li et al., J. Chem. Phys. 142, 204302 (2015)]. By inspecting convergence, 16 beads are used in computing free-energy barriers at 300 K ≤ T ≤ 1000 K, while different numbers of beads are used for transmission coefficients. The present RPMD rates are in excellent agreement with quantum rates computed on the same potential energy surface, as well as with the experimental measurements, demonstrating further that the RPMD is capable of producing accurate rates for polyatomic chemical reactions even at rather low temperatures.

  6. Underwater acoustic communication research at TNO-Past and present

    NARCIS (Netherlands)

    Dol, H.; Walree, P. van

    2011-01-01

    This paper provides an overview of more than 12 years of underwater acoustic communication research at the Sonar Department of TNO The Hague. The research covered both point-to-point links and relay networks, from long-range covert communication to short-range high-data-rate communication, for both

  7. Communication Analysis modelling techniques

    CERN Document Server

    España, Sergio; Pastor, Óscar; Ruiz, Marcela

    2012-01-01

    This report describes and illustrates several modelling techniques proposed by Communication Analysis; namely Communicative Event Diagram, Message Structures and Event Specification Templates. The Communicative Event Diagram is a business process modelling technique that adopts a communicational perspective by focusing on communicative interactions when describing the organizational work practice, instead of focusing on physical activities1; at this abstraction level, we refer to business activities as communicative events. Message Structures is a technique based on structured text that allows specifying the messages associated to communicative events. Event Specification Templates are a means to organise the requirements concerning a communicative event. This report can be useful to analysts and business process modellers in general, since, according to our industrial experience, it is possible to apply many Communication Analysis concepts, guidelines and criteria to other business process modelling notation...

  8. Improving Pathologists' Communication Skills.

    Science.gov (United States)

    Dintzis, Suzanne

    2016-08-01

    The 2015 Institute of Medicine report on diagnostic error has placed a national spotlight on the importance of improving communication among clinicians and between clinicians and patients [1]. The report emphasizes the critical role that communication plays in patient safety and outlines ways that pathologists can support this process. Despite recognition of communication as an essential element in patient care, pathologists currently undergo limited (if any) formal training in communication skills. To address this gap, we at the University of Washington Medical Center developed communication training with the goal of establishing best practice procedures for effective pathology communication. The course includes lectures, role playing, and simulated clinician-pathologist interactions for training and evaluation of pathology communication performance. Providing communication training can help create reliable communication pathways that anticipate and address potential barriers and errors before they happen.

  9. Communication at millimeter waves

    Science.gov (United States)

    Kamal, A. K.; Christopher, P. F.

    The advantage and disadvantages of millimeter waves for terrestrial and satellite communications are enumerated. Atmospheric attenuation is discussed in detail, with brief attention given to signal loss in particulates, sandstorms, snow, hail, and fog. Short closed forms are then found for gaseous attenuation on ground-satellite paths. An exponential rain loss probability density function is used in generating atmospheric loss at arbitrary required availability. It is pointed out that this loss (as a function of frequency) can be used to pick optimum carrier frequencies as a function of location, required availability, elevation angle, and system cost. An estimate is made of the rate-of-change of millimeter wave device availability. Special attention is given to GaAs FETs, not only because they will be useful, but because one phase of their millimeter wave performance is predictable: their noise performance as a function of frequency can be estimated with the aid of a Fukui equation.

  10. On the Ergodic Secrecy Capacity with Full Duplex Communication

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Mogensen, Preben Elgaard

    2017-01-01

    Full duplex communication promises performance gains in terms of the throughput and the delay. Generally, it has been shown that the throughput and delay gains of full duplex communication are somewhat limited in realistic network settings, leading researchers to study other possible applications...... capacity for a pair of nodes with full duplex communication. The ergodic secrecy rate with full duplex communication is found to grow linearly with the log of the direct channel SNR as opposed to the flattened out secrecy rate with conventional half duplex communication, irrespective of the eavesdropper...

  11. New Research in Communication Theory: A Summary.

    Science.gov (United States)

    Haun, Martha J.

    Recent studies in communication theory are outlined and briefly discussed. Categories of research included are information systems, interpersonal communication, mass communication, organizational communication, intercultural communication, political communication, instructional communication, and health communication. Except for the area of health…

  12. Cellular communication through light.

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    Full Text Available Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry.

  13. Affordable underwater wireless optical communication using LEDs

    Science.gov (United States)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  14. Digital Marketing Communication

    OpenAIRE

    Corniani, Margherita

    2006-01-01

    Digital marketing communication is directed to profiled targets, which are active in the communication process. Every communication flow can ask for an information answer from the market. This opportunity grants immediate feed-backs and feed-forwards, so that digital communication can be easily and cheaply measured; digital communication flows are diffused at costs that are getting lower and lower, but it asks specialized and deep competences to communication managers. The ease in the flowing...

  15. [Leadership and communication].

    Science.gov (United States)

    Henninger, Michael; Barth, Christina

    2009-01-01

    Medical leadership requires specific communication skills in order to meet professional demands. Communicative behaviour is usually highly automated and not necessarily conscious. Managerial communication competes against elaborated but not role-specific behaviour patterns, especially in critical situations. Accordingly, competent medical leadership requires the awareness of individual communication habits as well as the knowledge and ability to use conversation techniques suitable for a specific situational context. The training of leadership-related communication techniques requires the de-automation of existing skills and a problem-oriented construction and re-automation of new communication techniques.

  16. Simultaneous classical communication and quantum key distribution using continuous variables*

    Science.gov (United States)

    Qi, Bing

    2016-10-01

    Presently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters show that both deterministic classical communication with a bit error rate of 10-9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.

  17. A new generation of IC based beam steering devices for free-space optical communication

    Science.gov (United States)

    Bedi, Vijit

    Free Space Optical (FSO) communication has tremendously advanced within the last decade to meet the ever increasing demand for higher communication bandwidth. Advancement in laser technology since its invention in the 1960's [1] attracted them to be the dominant source in FSO communication modules. The future of FSO systems lay in implementing semiconductor lasers due to their small size, power efficiency and mass fabrication abilities. In the near future, these systems are very likely to be used in space and ground based applications and revolutionary beam steering technologies will be required for distant communications in free-space. The highly directional characteristic inherent to a laser beam challenges and calls for new beam pointing and steering technologies for such type of communication. In this dissertation, research is done on a novel FSO communication device based on semiconductor lasers for high bandwidth communication. The "Fly eye transceiver" is an extremely wide steering bandwidth, completely non-mechanical FSO laser communication device primarily designed to replace traditional mechanical beam steering optical systems. This non-mechanical FSO device possesses a full spherical steering range and a very high tracking bandwidth. Inspired by the evolutionary model of a fly's eye, the full spherical steering range is assured by electronically controlled switching of its sub-eyes. Non mechanical technologies used in the past for beam steering such as acousto-optic Bragg cells, liquid crystal arrays or piezoelectric elements offer the wide steering bandwidth and fast response time, but are limited in their angular steering range. Mechanical gimbals offer a much greater steering range but face a much slower response time or steering bandwidth problem and often require intelligent adaptive controls with bulky driver amplifiers to feed their actuators. As a solution to feed both the fast and full spherical steering, the Fly-eye transceiver is studied as

  18. Software-Synchronized All-Optical Sampling for Fiber Communication Systems

    Science.gov (United States)

    Westlund, Mathias; Sunnerud, Henrik; Karlsson, Magnus; Andrekson, Peter A.

    2005-03-01

    This paper describes a software-synchronized all-optical sampling system that presents synchronous eye diagrams and data patterns as well as calculates accurate Q values without requiring clock recovery. A synchronization algorithm is presented that calculates the offset frequency between the data bit rate and the sampling rate, and as a result, synchronous eye diagrams can be presented. The algorithm is shown to be robust toward poor signal quality and adds less than 100-fs timing drift to the eye diagrams. An extension of the software synchronization algorithm makes it possible to automatically find the pattern length of a periodic data pattern in a data signal. As a result, individual pulses can be investigated and detrimental effects present on the data signal can be identified. Noise averaging can also be applied. To measure accurate Q values without clock recovery, a high sampling rate is required in order to establish the noise statistics of the measured signal before any timing drift occurs. This paper presents a system with a 100-MHz sampling rate that measures accurate Q values at bit rates as high as 160 Gb/s. The high bandwidth of the optical sampling system also contributes to sampling more noise, which in turn results in lower Q values compared with conventional electrical sampling with a lower bandwidth. A theory that estimates the optically sampled Q values as a function of the sampling gate width is proposed and experimentally verified.

  19. Communicating with Professionals

    Medline Plus

    Full Text Available ... rushed than you (or your professionals) want. Simple communication skills can help you get what you need – ... at the hospital or during office visits. Good communication skills help you get better results from the ...

  20. Communicating with Professionals

    Medline Plus

    Full Text Available ... more rushed than you (or your professionals) want. Simple communication skills can help you get what you ... Introduction - Taking Control of Your Medicines - Medicine Assistance Programs - Medicine Checklist - Medication Tracker Communicating with Professionals - Introduction - ...