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Sample records for achieve efficient signal

  1. Achieving efficient RNAi therapy: progress and challenges

    Directory of Open Access Journals (Sweden)

    Kun Gao

    2013-07-01

    Full Text Available RNA interference (RNAi has been harnessed to produce a new class of drugs for treatment of various diseases. This review summarizes the most important parameters that govern the silencing efficiency and duration of the RNAi effect such as small interfering RNA (siRNA stability and modification, the type of delivery system and particle sizing methods. It also discusses the predominant barriers for siRNA delivery, such as off-target effects and introduces internalization, endosomal escape and mathematical modeling in RNAi therapy and combinatorial RNAi. At present, effective delivery of RNAi therapeutics in vivo remains a challenge although significant progress has been made in this field.

  2. Achieving Energy Efficiency Through Real-Time Feedback

    Energy Technology Data Exchange (ETDEWEB)

    Nesse, Ronald J.

    2011-09-01

    Through the careful implementation of simple behavior change measures, opportunities exist to achieve strategic gains, including greater operational efficiencies, energy cost savings, greater tenant health and ensuing productivity and an improved brand value through sustainability messaging and achievement.

  3. Achieving Energy Efficient Ship Operations Under Third Party Management

    DEFF Research Database (Denmark)

    Taudal Poulsen, René; Sornn-Friese, Henrik

    2015-01-01

    of time to produce and provide reliable energy efficiency information cause energy efficiency gaps. The paper brings together the energy efficiency and ship management literatures, demonstrating how ship management models influence energy efficiency in ship operations. Achieving energy efficiency in ship...... operations is particularly challenging under third party ship management. Finally, the paper discusses management implications for shipping companies, which outsource ship management to third parties.......Profitable energy saving measures are often not fully implemented in shipping, causing energy efficiency gaps. The paper identifies energy efficiency gaps in ship operations, and explores their causes. Lack of information on energy efficiency, lack of energy training at sea and onshore and lack...

  4. Achieving Energy Efficiency in Accordance with Bioclimatic Architecture Principles

    Science.gov (United States)

    Bajcinovci, Bujar; Jerliu, Florina

    2016-12-01

    By using our natural resources, and through inefficient use of energy, we produce much waste that can be recycled as a useful resource, which further contributes to climate change. This study aims to address energy effective bioclimatic architecture principles, by which we can achieve a potential energy savings, estimated at thirty-three per cent, mainly through environmentally affordable reconstruction, resulting in low negative impact on the environment. The study presented in this paper investigated the Ulpiana neighbourhood of Prishtina City, focusing on urban design challenges, energy efficiency and air pollution issues. The research methods consist of empirical observations through the urban spatial area using a comparative method, in order to receive clearer data and information research is conducted within Ulpiana's urban blocks, shapes of architectural structures, with the objective focusing on bioclimatic features in terms of the morphology and microclimate of Ulpiana. Energy supply plays a key role in the economic development of any country, hence, bioclimatic design principles for sustainable architecture and energy efficiency, present an evolutive integrated strategy for achieving efficiency and healthier conditions for Kosovar communities. Conceptual findings indicate that with the integrated design strategy: energy efficiency, and passive bioclimatic principles will result in a bond of complex interrelation between nature, architecture, and community. The aim of this study is to promote structured organized actions to be taken in Prishtina, and Kosovo, which will result in improved energy efficiency in all sectors, and particularly in the residential housing sector.

  5. Achieving Energy Efficiency in Accordance with Bioclimatic Architecture Principles

    Directory of Open Access Journals (Sweden)

    Bajcinovci Bujar

    2016-12-01

    Full Text Available By using our natural resources, and through inefficient use of energy, we produce much waste that can be recycled as a useful resource, which further contributes to climate change. This study aims to address energy effective bioclimatic architecture principles, by which we can achieve a potential energy savings, estimated at thirty-three per cent, mainly through environmentally affordable reconstruction, resulting in low negative impact on the environment. The study presented in this paper investigated the Ulpiana neighbourhood of Prishtina City, focusing on urban design challenges, energy efficiency and air pollution issues. The research methods consist of empirical observations through the urban spatial area using a comparative method, in order to receive clearer data and information research is conducted within Ulpiana’s urban blocks, shapes of architectural structures, with the objective focusing on bioclimatic features in terms of the morphology and microclimate of Ulpiana. Energy supply plays a key role in the economic development of any country, hence, bioclimatic design principles for sustainable architecture and energy efficiency, present an evolutive integrated strategy for achieving efficiency and healthier conditions for Kosovar communities. Conceptual findings indicate that with the integrated design strategy: energy efficiency, and passive bioclimatic principles will result in a bond of complex interrelation between nature, architecture, and community. The aim of this study is to promote structured organized actions to be taken in Prishtina, and Kosovo, which will result in improved energy efficiency in all sectors, and particularly in the residential housing sector.

  6. Efficient sliding spotlight SAR raw signal simulation of extended scenes

    Directory of Open Access Journals (Sweden)

    Huang Pingping

    2011-01-01

    Full Text Available Abstract Sliding spotlight mode is a novel synthetic aperture radar (SAR imaging scheme with an achieved azimuth resolution better than stripmap mode and ground coverage larger than spotlight configuration. However, its raw signal simulation of extended scenes may not be efficiently implemented in the two-dimensional (2D Fourier transformed domain. This article presents a novel sliding spotlight raw signal simulation approach from the wide-beam SAR imaging modes. This approach can generate sliding spotlight raw signal not only from raw data evaluated by the simulators, but also from real data in the stripmap/spotlight mode. In order to obtain the desired raw data from conventional stripmap/spotlight mode, the azimuth time-varying filtering, which is implemented by de-rotation and low-pass filtering, is adopted. As raw signal of extended scenes in the stripmap/spotlight mode can efficiently be evaluated in the 2D Fourier domain, the proposed approach provides an efficient sliding spotlight SAR simulator of extended scenes. Simulation results validate this efficient simulator.

  7. The efficient algorithms for achieving Euclidean distance transformation.

    Science.gov (United States)

    Shih, Frank Y; Wu, Yi-Ta

    2004-08-01

    Euclidean distance transformation (EDT) is used to convert a digital binary image consisting of object (foreground) and nonobject (background) pixels into another image where each pixel has a value of the minimum Euclidean distance from nonobject pixels. In this paper, the improved iterative erosion algorithm is proposed to avoid the redundant calculations in the iterative erosion algorithm. Furthermore, to avoid the iterative operations, the two-scan-based algorithm by a deriving approach is developed for achieving EDT correctly and efficiently in a constant time. Besides, we discover when obstacles appear in the image, many algorithms cannot achieve the correct EDT except our two-scan-based algorithm. Moreover, the two-scan-based algorithm does not require the additional cost of preprocessing or relative-coordinates recording.

  8. Efficient audio signal processing for embedded systems

    Science.gov (United States)

    Chiu, Leung Kin

    As mobile platforms continue to pack on more computational power, electronics manufacturers start to differentiate their products by enhancing the audio features. However, consumers also demand smaller devices that could operate for longer time, hence imposing design constraints. In this research, we investigate two design strategies that would allow us to efficiently process audio signals on embedded systems such as mobile phones and portable electronics. In the first strategy, we exploit properties of the human auditory system to process audio signals. We designed a sound enhancement algorithm to make piezoelectric loudspeakers sound ”richer" and "fuller." Piezoelectric speakers have a small form factor but exhibit poor response in the low-frequency region. In the algorithm, we combine psychoacoustic bass extension and dynamic range compression to improve the perceived bass coming out from the tiny speakers. We also developed an audio energy reduction algorithm for loudspeaker power management. The perceptually transparent algorithm extends the battery life of mobile devices and prevents thermal damage in speakers. This method is similar to audio compression algorithms, which encode audio signals in such a ways that the compression artifacts are not easily perceivable. Instead of reducing the storage space, however, we suppress the audio contents that are below the hearing threshold, therefore reducing the signal energy. In the second strategy, we use low-power analog circuits to process the signal before digitizing it. We designed an analog front-end for sound detection and implemented it on a field programmable analog array (FPAA). The system is an example of an analog-to-information converter. The sound classifier front-end can be used in a wide range of applications because programmable floating-gate transistors are employed to store classifier weights. Moreover, we incorporated a feature selection algorithm to simplify the analog front-end. A machine

  9. Achieving energy efficiency through behaviour change: what does it take?

    Energy Technology Data Exchange (ETDEWEB)

    Barbu, A.-D. [European Environment Agency (EEA), Copenhagen (Denmark); Griffiths, N.; Morton, G. [Ricardo-AEA (United Kingdom)

    2013-04-15

    On October 2012, the European Union adopted the Energy Efficiency Directive in reaction to the fact that EU Member States were not on track to reduce primary energy consumption by 20 % by 2020. The implementation of this directive, and other policies that have been adopted in recent years, will require a change in consumer behaviour and energy consumption practices. Within this context, and related to on-going debates on the same subject, a new European Environment Agency (EEA) report argues that correctly navigating the interface between policymaking and human behaviour is key to achieving sustained reductions in energy consumption. As such, the report provides timely and reliable information and analysis to those involved in designing policy measures to reduce energy consumption which target the end consumer. A growing body of evidence in academic literature demonstrates that there is potential for energy savings due to measures targeting behaviour. There is, however, one issue that has not been covered by previous studies, and which the EEA report directly addresses, namely the distinction between consumer behaviour and consumption practices. Most recent academic literature argues that it is the consumption practices themselves that need careful scrutiny as they tend to lock consumers into patterns that are more and more energy intensive and they involve a wide range of actors. From the energy efficiency policy design perspective, this is relevant because these actors need to be involved from the outset of the policy process. The report also argues that a whole range of changes need to take place in the way energy markets function and are regulated in order to enable the consumer to actively engage with these markets. The report however does not include a discussion on the socio-economic implications of these structural changes. During 2013, the EEA will launch a survey via social media and its own website to follow up on conclusions of the report. The aim will

  10. Air Force Achieves Fuel Efficiency through Industry Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-01

    The U.S. Air Force’s Air Mobility Command (AMC) is changing the way it does business. It is saving energy and money through an aircraft fleet fuel-efficiency program inspired by private industry best practices and ideas resulting from the empowered fuel savings culture.

  11. Efficient Mobility Management Signalling in Network Mobility Supported PMIPV6.

    Science.gov (United States)

    Samuelraj, Ananthi Jebaseeli; Jayapal, Sundararajan

    2015-01-01

    Proxy Mobile IPV6 (PMIPV6) is a network based mobility management protocol which supports node's mobility without the contribution from the respective mobile node. PMIPV6 is initially designed to support individual node mobility and it should be enhanced to support mobile network movement. NEMO-BSP is an existing protocol to support network mobility (NEMO) in PMIPV6 network. Due to the underlying differences in basic protocols, NEMO-BSP cannot be directly applied to PMIPV6 network. Mobility management signaling and data structures used for individual node's mobility should be modified to support group nodes' mobility management efficiently. Though a lot of research work is in progress to implement mobile network movement in PMIPV6, it is not yet standardized and each suffers with different shortcomings. This research work proposes modifications in NEMO-BSP and PMIPV6 to achieve NEMO support in PMIPV6. It mainly concentrates on optimizing the number and size of mobility signaling exchanged while mobile network or mobile network node changes its access point.

  12. Efficient Mobility Management Signalling in Network Mobility Supported PMIPV6

    Directory of Open Access Journals (Sweden)

    Ananthi Jebaseeli Samuelraj

    2015-01-01

    Full Text Available Proxy Mobile IPV6 (PMIPV6 is a network based mobility management protocol which supports node’s mobility without the contribution from the respective mobile node. PMIPV6 is initially designed to support individual node mobility and it should be enhanced to support mobile network movement. NEMO-BSP is an existing protocol to support network mobility (NEMO in PMIPV6 network. Due to the underlying differences in basic protocols, NEMO-BSP cannot be directly applied to PMIPV6 network. Mobility management signaling and data structures used for individual node’s mobility should be modified to support group nodes’ mobility management efficiently. Though a lot of research work is in progress to implement mobile network movement in PMIPV6, it is not yet standardized and each suffers with different shortcomings. This research work proposes modifications in NEMO-BSP and PMIPV6 to achieve NEMO support in PMIPV6. It mainly concentrates on optimizing the number and size of mobility signaling exchanged while mobile network or mobile network node changes its access point.

  13. 10 CFR 433.7 - Water used to achieve energy efficiency. [Reserved

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Water used to achieve energy efficiency. 433.7 Section 433.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND... achieve energy efficiency....

  14. Waveform Fingerprinting for Efficient Seismic Signal Detection

    Science.gov (United States)

    Yoon, C. E.; OReilly, O. J.; Beroza, G. C.

    2013-12-01

    Cross-correlating an earthquake waveform template with continuous waveform data has proven a powerful approach for detecting events missing from earthquake catalogs. If templates do not exist, it is possible to divide the waveform data into short overlapping time windows, then identify window pairs with similar waveforms. Applying these approaches to earthquake monitoring in seismic networks has tremendous potential to improve the completeness of earthquake catalogs, but because effort scales quadratically with time, it rapidly becomes computationally infeasible. We develop a fingerprinting technique to identify similar waveforms, using only a few compact features of the original data. The concept is similar to human fingerprints, which utilize key diagnostic features to identify people uniquely. Analogous audio-fingerprinting approaches have accurately and efficiently found similar audio clips within large databases; example applications include identifying songs and finding copyrighted content within YouTube videos. In order to fingerprint waveforms, we compute a spectrogram of the time series, and segment it into multiple overlapping windows (spectral images). For each spectral image, we apply a wavelet transform, and retain only the sign of the maximum magnitude wavelet coefficients. This procedure retains just the large-scale structure of the data, providing both robustness to noise and significant dimensionality reduction. Each fingerprint is a high-dimensional, sparse, binary data object that can be stored in a database without significant storage costs. Similar fingerprints within the database are efficiently searched using locality-sensitive hashing. We test this technique on waveform data from the Northern California Seismic Network that contains events not detected in the catalog. We show that this algorithm successfully identifies similar waveforms and detects uncataloged low magnitude events in addition to cataloged events, while running to completion

  15. Achieving Textbook Multigrid Efficiency for Hydrostatic Ice Sheet Flow

    KAUST Repository

    Brown, Jed

    2013-03-12

    The hydrostatic equations for ice sheet flow offer improved fidelity compared with the shallow ice approximation and shallow stream approximation popular in today\\'s ice sheet models. Nevertheless, they present a serious bottleneck because they require the solution of a three-dimensional (3D) nonlinear system, as opposed to the two-dimensional system present in the shallow stream approximation. This 3D system is posed on high-aspect domains with strong anisotropy and variation in coefficients, making it expensive to solve with current methods. This paper presents a Newton--Krylov multigrid solver for the hydrostatic equations that demonstrates textbook multigrid efficiency (an order of magnitude reduction in residual per iteration and solution of the fine-level system at a small multiple of the cost of a residual evaluation). Scalability on Blue Gene/P is demonstrated, and the method is compared to various algebraic methods that are in use or have been proposed as viable approaches.

  16. New all-optical RIN suppressing, image rejection receiver with efficient use of LO- and signal-power

    DEFF Research Database (Denmark)

    Pedersen, Rune Johan Skullerud; Ebskamp, F.

    1993-01-01

    An all-optical method of achieving a heterodyne signal is presented whereby the local oscillator (LO) relative intensity noise (RIN) and the image channel have been suppressed while efficient use of both LO and signal power is made. This is achieved with only one photodetector, compared to four...

  17. Efficient sequential compression of multi-channel biomedical signals

    OpenAIRE

    Capurro, Ignacio; Lecumberry, Federico; Martín, Álvaro; Ramírez, Ignacio; Rovira, Eugenio; Seroussi, Gadiel

    2016-01-01

    This work proposes lossless and near-lossless compression algorithms for multi-channel biomedical signals. The algorithms are sequential and efficient, which makes them suitable for low-latency and low-power signal transmission applications. We make use of information theory and signal processing tools (such as universal coding, universal prediction, and fast online implementations of multivariate recursive least squares), combined with simple methods to exploit spatial as well as temporal re...

  18. Efficient sequential compression of multi-channel biomedical signals.

    Science.gov (United States)

    Capurro, Ignacio; Lecumberry, Federico; Martin, Alvaro; Ramirez, Ignacio; Rovira, Eugenio; Seroussi, Gadiel

    2016-06-21

    This work proposes lossless and near-lossless compression algorithms for multi-channel biomedical signals. The algorithms are sequential and efficient, which makes them suitable for low-latency and low-power signal transmission applications. We make use of information theory and signal processing tools (such as universal coding, universal prediction, and fast online implementations of multivariate recursive least squares), combined with simple methods to exploit spatial as well as temporal redundancies typically present in biomedical signals. The algorithms are tested with publicly available electroencephalogram and electrocardiogram databases, surpassing in all cases the current state of the art in near-lossless and lossless compression ratios.

  19. Development of Pathways to Achieve the SE4ALL Energy Efficiency Objective: Global and Regional Potential for Energy Efficiency Improvements

    DEFF Research Database (Denmark)

    Gregg, Jay Sterling; Balyk, Olexandr; Pérez, Cristian Hernán Cabrera

    efficiency. When the SE4ALL renewable energy objective is achieved, the economically optimal solution produced by ETSAP-TIAM also includes a reduction in energy intensity: globally, the compound annual reduction in energy intensity of GDP is 1.8% when the renewable energy objective is achieved. Likewise...

  20. 10 CFR 435.7 - Water used to achieve energy efficiency. [Reserved

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Water used to achieve energy efficiency. 435.7 Section 435.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise...

  1. Area Efficient Rapid Signal Acquisition scheme for High Doppler DSSS Signals

    Directory of Open Access Journals (Sweden)

    D. Karunakar Reddy

    2013-04-01

    Full Text Available The Direct Sequence Spread Spectrum (DSSS communication system is widely used in ground to airmissile links due to its anti-jam and low Signal to Noise Ratio (SNR requirement advantages. The paperpresents the challenges in achieving fast signal acquisition in this scenario and brings out theimplementation challenges for achieving simultaneous Doppler estimation and phase delay of PseudoNoise (PN code. A new scheme for PN code phase delay estimation with correlation of differential signals,followed by precise Doppler estimation using Fast Fourier Transform (FFT is presented. The areaoptimized Field Programmable Gate Array (FPGA friendly architecture is utilized for rapid signalacquisition by combining both time and frequency domain approaches. The advanced design practices inFPGAs are used to achieve resource sharing and high clock speed of operation. The architecture issynthesized for Virtex-6 LX240T FPGA, resulting in 52% of area occupancy and 134 MHz of maximumallowed clock frequency value.

  2. Quantifying efficient information transduction of biochemical signaling cascades

    CERN Document Server

    Tsuruyama, Tatsuaki

    2016-01-01

    Cells can be considered as systems that utilize changes in thermodynamic entropy as information. Therefore, they serve as useful models for investigating the relationships between entropy production and information transmission, i.e., signal transduction. Based on the hypothesis that cells apply a chemical reaction cascade for the most efficient transduction of information, we adopted a coding design that minimizes the number of bits per concentration of molecules that are employed for information transduction. As a result, the average rate of entropy production is uniform across all cycles in a cascade reaction. Thus, the entropy production rate can be a valuable measure for the quantification of intracellular signal transduction.

  3. Time Lens based Optical Fourier Transformation for All-Optical Signal Processing of Spectrally-Efficient Data

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Lillieholm, Mads;

    2016-01-01

    four-wave mixing (FWM), separated by a dispersive medium, which enables time-to-frequency and frequency-to-time conversions simultaneously, thus performing an exchange between the temporal and spectral profiles of the input signal. Using the proposed complete OFT, several advanced all-optical signal......We review recent progress in the use of time lens based optical Fourier transformation for advanced all-optical signal processing. A novel time lens based complete optical Fourier transformation (OFT) technique is introduced. This complete OFT is based on two quadratic phase-modulation stages using...... processing schemes for spectrally-efficient systems and networks have been achieved, including all-optical generation, detection and format conversion of spectrally-efficient signals. The spectrally-efficient signals in this paper mainly refer to efficiently multiplexed signals with a high symbol rate per Hz...

  4. Efficient feature for classification of eye movements using electrooculography signals

    Directory of Open Access Journals (Sweden)

    Phukpattaranont Pornchai

    2016-01-01

    Full Text Available Electrooculography (EOG signal is widely and successfully used to detect activities of human eye. The advantages of the EOG-based interface over other conventional interfaces have been presented in the last two decades; however, due to a lot of information in EOG signals, the extraction of useful features should be done before the classification task. In this study, an efficient feature extracted from two directional EOG signals: vertical and horizontal signals has been presented and evaluated. There are the maximum peak and valley amplitude values, the maximum peak and valley position values, and slope, which are derived from both vertical and horizontal signals. In the experiments, EOG signals obtained from five healthy subjects with ten directional eye movements were employed: up, down, right, left, up-right, up-left, down-right down-left clockwise and counterclockwise. The mean feature values and their standard deviations have been reported. The difference between the mean values of the proposed feature from different eye movements can be clearly seen. Using the scatter plot, the differences in features can be also clearly observed. Results show that classification accuracy can approach 100% with a simple distinction feature rule. The proposed features can be useful for various advanced human-computer interface applications in future researches.

  5. Achieving "Massive MIMO" Spectral Efficiency with a Not-so-Large Number of Antennas

    CERN Document Server

    Huh, Hoon; Papadopoulos, Haralabos C; Ramprashad, Sean A

    2011-01-01

    The main focus and contribution of this paper is a novel network-MIMO TDD architecture that achieves spectral efficiencies comparable with "Massive MIMO", with one order of magnitude fewer antennas per active user per cell. The proposed architecture is based on a family of network-MIMO schemes defined by small clusters of cooperating base stations, zero-forcing multiuser MIMO precoding with suitable inter-cluster interference constraints, uplink pilot signals reuse across cells, and frequency reuse. The key idea consists of partitioning the users population into geographically determined "bins", such that all users in the same bin are statistically equivalent, and use the optimal network-MIMO architecture in the family for each bin. A scheduler takes care of serving the different bins on the time-frequency slots, in order to maximize a desired network utility function that captures some desired notion of fairness. This results in a mixed-mode network-MIMO architecture, where different schemes, each of which i...

  6. AN EFFICIENT APPROXIMATE MAXIMUM LIKELIHOOD SIGNAL DETECTION FOR MIMO SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Cao Xuehong

    2007-01-01

    This paper proposes an efficient approximate Maximum Likelihood (ML) detection method for Multiple-Input Multiple-Output (MIMO) systems, which searches local area instead of exhaustive search and selects valid search points in each transmit antenna signal constellation instead of all hyperplane. Both of the selection and search complexity can be reduced significantly. The method performs the tradeoff between computational complexity and system performance by adjusting the neighborhood size to select the valid search points. Simulation results show that the performance is comparable to that of the ML detection while the complexity is only as the small fraction of ML.

  7. Quantitative Assessment of the Efficiency of Physiological Signals in Emotional State Recognition for Healthcare Applications

    Directory of Open Access Journals (Sweden)

    B. Mojarradshafie

    2013-12-01

    Full Text Available efficient monitoring of emotions may provide medical information with diagnostic value for healthcare applications and clinical researches. Different emotions can generate specific patterns in physiology via Autonomic Nervous System (ANS. Consequently, we achieve an acceptable accuracy of the emotion classification using extracting relevant features from physiological signals. In this study, an experiment is conducted to elicit four emotional states (happiness, anger, sadness and relax in twenty four healthy subjects. The physiological signals such as ECG, SCL (Skin Conductivity Level, EMG and Respiration signal are recorded simultaneously. After necessary preprocessing for primary signals such as segmentation, filtering, smoothing, removing artifacts and removal of baseline drift, various features in time and frequency domain are extracted. Feature selection method is used to find best relevant features. Afterward, different dimension reduction algorithms and classification methods are used to compare the efficiency of different physiological signals in emotion recognition. The precision of classifications with different features is found to be higher than 70%. The results show that the different physiological signals have different ability to classify four given affective states. Our proposed methods can result in developing a robust emotional states recognition system for healthcare applications.

  8. Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels.

    Science.gov (United States)

    Singh, Meenesh R; Clark, Ezra L; Bell, Alexis T

    2015-11-10

    Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32-42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0-0.9 V, 0.9-1.95 V, and 1.95-3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices.

  9. Neurokinin-1 receptor signalling impacts bone marrow repopulation efficiency.

    Directory of Open Access Journals (Sweden)

    Alexandra Berger

    Full Text Available Tachykinins are a large group of neuropeptides with both central and peripheral activity. Despite the increasing number of studies reporting a growth supportive effect of tachykinin peptides in various in vitro stem cell systems, it remains unclear whether these findings are applicable in vivo. To determine how neurokinin-1 receptor (NK-1R deficient hematopoietic stem cells would behave in a normal in vivo environment, we tested their reconstitution efficiency using competitive bone marrow repopulation assays. We show here that bone marrow taken from NK-1R deficient mice (Tacr1(-/- showed lineage specific B and T cell engraftment deficits compared to wild-type competitor bone marrow cells, providing evidence for an involvement of NK-1R signalling in adult hematopoiesis. Tachykinin knockout mice lacking the peptides SP and/or HK-1 (Tac1 (-/-, Tac4 (-/- and Tac1 (-/-/Tac4 (-/- mice repopulated a lethally irradiated wild-type host with similar efficiency as competing wild-type bone marrow. The difference between peptide and receptor deficient mice indicates a paracrine and/or endocrine mechanism of action rather than autocrine signalling, as tachykinin peptides are supplied by the host environment.

  10. An efficient repeating signal detector to investigate earthquake swarms

    Science.gov (United States)

    Skoumal, Robert J.; Brudzinski, Michael R.; Currie, Brian S.

    2016-08-01

    Repetitive earthquake swarms have been recognized as key signatures in fluid injection induced seismicity, precursors to volcanic eruptions, and slow slip events preceding megathrust earthquakes. We investigate earthquake swarms by developing a Repeating Signal Detector (RSD), a computationally efficient algorithm utilizing agglomerative clustering to identify similar waveforms buried in years of seismic recordings using a single seismometer. Instead of relying on existing earthquake catalogs of larger earthquakes, RSD identifies characteristic repetitive waveforms by rapidly identifying signals of interest above a low signal-to-noise ratio and then grouping based on spectral and time domain characteristics, resulting in dramatically shorter processing time than more exhaustive autocorrelation approaches. We investigate seismicity in four regions using RSD: (1) volcanic seismicity at Mammoth Mountain, California, (2) subduction-related seismicity in Oaxaca, Mexico, (3) induced seismicity in Central Alberta, Canada, and (4) induced seismicity in Harrison County, Ohio. In each case, RSD detects a similar or larger number of earthquakes than existing catalogs created using more time intensive methods. In Harrison County, RSD identifies 18 seismic sequences that correlate temporally and spatially to separate hydraulic fracturing operations, 15 of which were previously unreported. RSD utilizes a single seismometer for earthquake detection which enables seismicity to be quickly identified in poorly instrumented regions at the expense of relying on another method to locate the new detections. Due to the smaller computation overhead and success at distances up to ~50 km, RSD is well suited for real-time detection of low-magnitude earthquake swarms with permanent regional networks.

  11. Efficient Sampling of Band-limited Signals from Sine Wave Crossings

    CERN Document Server

    Selva, J

    2010-01-01

    This paper presents an efficient method for reconstructing a band-limited signal in the discrete domain from its crossings with a sine wave. The method makes it possible to design A/D converters that only deliver the crossing timings, which are then used to interpolate the input signal at arbitrary instants. Potentially, it may allow for reductions in power consumption and complexity, as well as for an increase in the achievable sampling bandwidth. The reconstruction in the discrete domain is based on a recently-proposed modification of the Lagrange interpolator, which is readily implementable with linear complexity and efficiently, given that it re-uses known schemes for variable fractional-delay (VFD) filters. As a spin-off, the method allows one to perform spectral analysis from sine wave crossings with the complexity of the FFT. Finally, the results in the paper are validated in a numerical example.

  12. Approaches to achieve high grain yield and high resource use efficiency in rice

    Directory of Open Access Journals (Sweden)

    Jianchang YANG

    2015-06-01

    Full Text Available This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.

  13. HOP: Achieving Efficient Anonymity in MANETs by Combining HIP, OLSR, and Pseudonyms

    Directory of Open Access Journals (Sweden)

    Campos Javier

    2011-01-01

    Full Text Available Offering secure and anonymous communications in mobile ad hoc networking environments is essential to achieve confidence and privacy, thus promoting widespread adoption of this kind of networks. In addition, some minimum performance levels must be achieved for any solution to be practical and become widely adopted. In this paper, we propose and implement HOP, a novel solution based on cryptographic Host Identity Protocol (HIP that offers security and user-level anonymity in MANET environments while maintaining good performance levels. In particular, we introduce enhancements to the authentication process to achieve Host Identity Tag (HIT relationship anonymity, along with source/destination HIT anonymity when combined with multihoming. Afterward we detail how we integrate our improved version of HIP with the OLSR routing protocol to achieve efficient support for pseudonyms. We implemented our proposal in an experimental testbed, and the results obtained show that performance levels achieved are quite good, and that the integration with OLSR is achieved with a low overhead.

  14. An efficient semi-blind source extraction algorithm and its applications to biomedical signal extraction

    Institute of Scientific and Technical Information of China (English)

    YE YaLan; SHEU Phillip C-Y; ZENG JiaZhi; WANG Gang; LU Ke

    2009-01-01

    In many applications, such as biomedical engineering, it is often required to extract a desired signal instead of all source signals. This can be achieved by blind source extraction (BSE) or semi-blind source extraction, which is a powerful technique emerging from the neural network field. In this paper, we propose an efficient semi-blind source extraction algorithm to extract a desired source signal as its first output signal by using a priori information about its kurtosis range. The algorithm is robust to outliers and spiky noise because of adopting a classical robust contrast function. And it is also robust to the estimation errors of the kurtoaia range of the desired signal providing the estimation errors are not large. The algorithm has good extraction performance, even in some poor situations when the kurtosis values of some source signals are very close to each other. Its convergence stability and robustness are theoretically analyzed. Simulations and experiments on artificial generated data and real-world data have confirmed these results.

  15. Computationally efficient sub-band coding of ECG signals.

    Science.gov (United States)

    Husøy, J H; Gjerde, T

    1996-03-01

    A data compression technique is presented for the compression of discrete time electrocardiogram (ECG) signals. The compression system is based on sub-band coding, a technique traditionally used for compressing speech and images. The sub-band coder employs quadrature mirror filter banks (QMF) with up to 32 critically sampled sub-bands. Both finite impulse response (FIR) and the more computationally efficient infinite impulse response (IIR) filter banks are considered as candidates in a complete ECG coding system. The sub-bands are threshold, quantized using uniform quantizers and run-length coded. The output of the run-length coder is further compressed by a Huffman coder. Extensive simulations indicate that 16 sub-bands are a suitable choice for this application. Furthermore, IIR filter banks are preferable due to their superiority in terms of computational efficiency. We conclude that the present scheme, which is suitable for real time implementation on a PC, can provide compression ratios between 5 and 15 without loss of clinical information.

  16. A preferential design approach for energy-efficient and robust implantable neural signal processing hardware.

    Science.gov (United States)

    Narasimhan, Seetharam; Chiel, Hillel J; Bhunia, Swarup

    2009-01-01

    For implantable neural interface applications, it is important to compress data and analyze spike patterns across multiple channels in real time. Such a computational task for online neural data processing requires an innovative circuit-architecture level design approach for low-power, robust and area-efficient hardware implementation. Conventional microprocessor or Digital Signal Processing (DSP) chips would dissipate too much power and are too large in size for an implantable system. In this paper, we propose a novel hardware design approach, referred to as "Preferential Design" that exploits the nature of the neural signal processing algorithm to achieve a low-voltage, robust and area-efficient implementation using nanoscale process technology. The basic idea is to isolate the critical components with respect to system performance and design them more conservatively compared to the noncritical ones. This allows aggressive voltage scaling for low power operation while ensuring robustness and area efficiency. We have applied the proposed approach to a neural signal processing algorithm using the Discrete Wavelet Transform (DWT) and observed significant improvement in power and robustness over conventional design.

  17. An Energy Efficient Compressed Sensing Framework for the Compression of Electroencephalogram Signals

    Directory of Open Access Journals (Sweden)

    Simon Fauvel

    2014-01-01

    Full Text Available The use of wireless body sensor networks is gaining popularity in monitoring and communicating information about a person’s health. In such applications, the amount of data transmitted by the sensor node should be minimized. This is because the energy available in these battery powered sensors is limited. In this paper, we study the wireless transmission of electroencephalogram (EEG signals. We propose the use of a compressed sensing (CS framework to efficiently compress these signals at the sensor node. Our framework exploits both the temporal correlation within EEG signals and the spatial correlations amongst the EEG channels. We show that our framework is up to eight times more energy efficient than the typical wavelet compression method in terms of compression and encoding computations and wireless transmission. We also show that for a fixed compression ratio, our method achieves a better reconstruction quality than the CS-based state-of-the art method. We finally demonstrate that our method is robust to measurement noise and to packet loss and that it is applicable to a wide range of EEG signal types.

  18. Subpixel shift with Fourier transform to achieve efficient and high-quality image interpolation

    Science.gov (United States)

    Chen, Qin-Sheng; Weinhous, Martin S.

    1999-05-01

    A new approach to image interpolation is proposed. Different from the conventional scheme, the interpolation of a digital image is achieved with a sub-unity coordinate shift technique. In the approach, the original image is first shifted by sub-unity distances matching the locations where the image values need to be restored. The original and the shifted images are then interspersed together, yielding an interpolated image. High quality sub-unity image shift which is crucial to the approach is accomplished by implementing the shift theorem of Fourier transformation. It is well known that under the Nyquist sampling criterion, the most accurate image interpolation can be achieved with the interpolating function (sinc function). A major drawback is its computation efficiency. The present approach can achieve an interpolation quality as good as that with the sinc function since the sub-unity shift in Fourier domain is equivalent to shifting the sinc function in spatial domain, while the efficiency, thanks to the fast Fourier transform, is very much improved. In comparison to the conventional interpolation techniques such as linear or cubic B-spline interpolation, the interpolation accuracy is significantly enhanced. In order to compensate for the under-sampling effects in the interpolation of 3D medical images owing to a larger inter-slice distance, proper window functions were recommended. The application of the approach to 2- and 3-D CT and MRI images produced satisfactory interpolation results.

  19. Energy efficient acquisition and reconstruction of EEG signals.

    Science.gov (United States)

    Singh, W; Shukla, A; Deb, S; Majumdar, A

    2014-01-01

    In Wireless Body Area Networks (WBAN) the energy consumption is dominated by sensing and communication. Previous Compressed Sensing (CS) based solutions to EEG tele-monitoring over WBAN's could only reduce the communication cost. In this work, we propose a matrix completion based formulation that can also reduce the energy consumption for sensing. We test our method with state-of-the-art CS based techniques and find that the reconstruction accuracy from our method is significantly better and that too at considerably less energy consumption. Our method is also tested for post-reconstruction signal classification where it outperforms previous CS based techniques. At the heart of the system is an Analog to Information Converter (AIC) implemented in 65nm CMOS technology. The pseudorandom clock generator enables random under-sampling and subsequent conversion by the 12-bit Successive Approximation Register Analog to Digital Converter (SAR ADC). AIC achieves a sample rate of 0.5 KS/s, an ENOB 9.54 bits, and consumes 108 nW from 1 V power supply.

  20. Efficiency of Switch-Mode Power Audio Amplifiers - Test Signals and Measurement Techniques

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    . An alternative signal is proposed for test purposes. The efficiency of a switch-mode power audio amplifier is modelled and measured with both sine wave and the proposed test signal as inputs. The results show that the choice of switching devices with low on resistances are unfairly favored when measuring...... the efficiency with sine waves. A 10% efficiency improvement was found for low power outputs. It is therefore of great importance to use proper test signals when measuring the efficiency....

  1. Enhanced signal-to-noise ratios in frog hearing can be achieved through amplitude death

    CERN Document Server

    Ahn, Kang-Hun

    2013-01-01

    In the ear, hair cells transform mechanical stimuli into neuronal signals with great sensitivity relying on certain active processes. Individual hair cell bundles of non-mammals such as frogs and turtles are known to show spontaneous oscillation. However hair bundles in vivo must be quiet in the absence of stimuli, otherwise, the signal is drowned in intrinsic noise. Thus, a certain mechanism is needed to exist in order to suppress intrinsic noise. Here, through a model study of elastically coupled hair bundles of bullfrog sacculi, we show that a low stimulus threshold and a high signal-to-noise ratio (SNR) can be achieved through the amplitude death phenomenon (the cessation of spontaneous oscillations by coupling). This phenomenon occurs only when the coupled hair bundles have inhomogeneous distribution, which is likely to be the case in biological systems. We show that the SNR has non-monotonic dependence on the mass of the overlying membrane, and find out that the SNR has maximum value in the region of th...

  2. Achievement-Relevant Personality: Relations with the Big Five and Validation of an Efficient Instrument.

    Science.gov (United States)

    Briley, Daniel A; Domiteaux, Matthew; Tucker-Drob, Elliot M

    2014-05-01

    Many achievement-relevant personality measures (APMs) have been developed, but the interrelations among APMs or associations with the broader personality landscape are not well-known. In Study 1, 214 participants were measured on 36 APMs and a measure of the Big Five. Factor analytic results supported the convergent and discriminant validity of five latent dimensions: performance, mastery, self-doubt, effort, and intellectual investment. Conscientiousness, neuroticism, and openness to experience had the most consistent associations with APMs. We constructed a more efficient scale- the Multidimensional Achievement-Relevant Personality Scale (MAPS). In Study 2, we replicated the factor structure and external correlates of the MAPS in a sample of 359 individuals. Finally, we validated the MAPS with four indicators of academic performance and demonstrated incremental validity.

  3. Achieving Efficient Channel Utilization for Data Communications in IEEE 802.11 WLAN

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; SHU Yantai

    2005-01-01

    In the IEEE 802. 11 protocol, the adoption of the exponential backoff technique leads to throughput performance strongly dependent on the initial contention window size and, most importantly, on the number of contending stations considered in the network. This paper proposes a simpie but accurate method to dynamically estimate the number of contending stations in a wireless local area network (WLAN). Based on estimation, all the mobile stations dynamically adjust the initial contention window in medium access control (MAC) layer to avoid collisions. The simulation results show that the proposed algorithm can achieve efficient channel utilization, higher system throughput, and better fairness performance.

  4. Energy efficiency enhancements for semiconductors, communications, sensors and software achieved in cool silicon cluster project

    Science.gov (United States)

    Ellinger, Frank; Mikolajick, Thomas; Fettweis, Gerhard; Hentschel, Dieter; Kolodinski, Sabine; Warnecke, Helmut; Reppe, Thomas; Tzschoppe, Christoph; Dohl, Jan; Carta, Corrado; Fritsche, David; Tretter, Gregor; Wiatr, Maciej; Detlef Kronholz, Stefan; Mikalo, Ricardo Pablo; Heinrich, Harald; Paulo, Robert; Wolf, Robert; Hübner, Johannes; Waltsgott, Johannes; Meißner, Klaus; Richter, Robert; Michler, Oliver; Bausinger, Markus; Mehlich, Heiko; Hahmann, Martin; Möller, Henning; Wiemer, Maik; Holland, Hans-Jürgen; Gärtner, Roberto; Schubert, Stefan; Richter, Alexander; Strobel, Axel; Fehske, Albrecht; Cech, Sebastian; Aßmann, Uwe; Pawlak, Andreas; Schröter, Michael; Finger, Wolfgang; Schumann, Stefan; Höppner, Sebastian; Walter, Dennis; Eisenreich, Holger; Schüffny, René

    2013-07-01

    An overview about the German cluster project Cool Silicon aiming at increasing the energy efficiency for semiconductors, communications, sensors and software is presented. Examples for achievements are: 1000 times reduced gate leakage in transistors using high-fc (HKMG) materials compared to conventional poly-gate (SiON) devices at the same technology node; 700 V transistors integrated in standard 0.35 μm CMOS; solar cell efficiencies above 19% at e-Commerce applications; processors and corresponding data links with 40% and 70% energy savings, respectively, by adaption of clock frequency and supply voltage in less than 20 ns; clock generator chip with tunable frequency from 83-666 MHz and 0.62-1.6 mW dc power; 90 Gb/s on-chip link over 6 mm and efficiency of 174 fJ/mm; dynamic biasing system doubling efficiency in power amplifiers; 60 GHz BiCMOS frontends with dc power to bandwidth ratio of 0.17 mW/MHz; driver assistance systems reducing energy consumption by 10% in cars Contribution to the Topical Issue “International Semiconductor Conference Dresden-Grenoble - ISCDG 2012”, Edited by Gérard Ghibaudo, Francis Balestra and Simon Deleonibus.

  5. An Efficient Wireless Recharging Mechanism for Achieving Perpetual Lifetime of Wireless Sensor Networks.

    Science.gov (United States)

    Yu, Hongli; Chen, Guilin; Zhao, Shenghui; Chang, Chih-Yung; Chin, Yu-Ting

    2016-12-23

    Energy recharging has received much attention in recent years. Several recharging mechanisms were proposed for achieving perpetual lifetime of a given Wireless Sensor Network (WSN). However, most of them require a mobile recharger to visit each sensor and then perform the recharging task, which increases the length of the recharging path. Another common weakness of these works is the requirement for the mobile recharger to stop at the location of each sensor. As a result, it is impossible for recharger to move with a constant speed, leading to inefficient movement. To improve the recharging efficiency, this paper takes "recharging while moving" into consideration when constructing the recharging path. We propose a Recharging Path Construction (RPC) mechanism, which enables the mobile recharger to recharge all sensors using a constant speed, aiming to minimize the length of recharging path and improve the recharging efficiency while achieving the requirement of perpetual network lifetime of a given WSN. Performance studies reveal that the proposed RPC outperforms existing proposals in terms of path length and energy utilization index, as well as visiting cycle.

  6. Energy-Efficient Optical Signal Processing Using Optical Time Lenses

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen;

    2015-01-01

    This chapter describes advanced functionalities for optical signal processing using optical time lenses. A special focus is devoted to functionalities that allow for energy-savings. In particular, we find that optical signal processing, where the processing is broadband and capable of handling ma...

  7. Energy-efficient FastICA implementation for biomedical signal separation.

    Science.gov (United States)

    Van, Lan-Da; Wu, Di-You; Chen, Chien-Shiun

    2011-11-01

    This paper presents an energy-efficient fast independent component analysis (FastICA) implementation with an early determination scheme for eight-channel electroencephalogram (EEG) signal separation. The main contributions are as follows: (1) energy-efficient FastICA using the proposed early determination scheme and the corresponding architecture; (2) cost-effective FastICA using the proposed preprocessing unit architecture with one coordinate rotation digital computer-based eigenvalue decomposition processor and the proposed one-unit architecture with the hardware reuse scheme; and (3) low-computation-time FastICA using the four parallel one-units architecture. The resulting power dissipation of the FastICA implementation for eight-channel EEG signal separation is 16.35 mW at 100 MHz at 1.0 V. Compared with the design without early determination, the proposed FastICA architecture implemented in united microelectronics corporation 90 nm 1P9M complementary metal-oxide-semiconductor process with a core area of 1.221 × 1.218 mm2 can achieve average energy reduction by 47.63%. From the post-layout simulation results, the maximum computation time is 0.29 s.

  8. Design and Analysis of an Efficient Primary Synchronization Signal Detector

    Directory of Open Access Journals (Sweden)

    Mathana.J.M

    2013-01-01

    Full Text Available In this paper, we present a novel design for the detection of primary synchronization signal in a Long Term Evolution (LTE system based device at the expense of low cost and low power. This is facilitated by using a matched filter architecture which incorporates parallel processing. The approach of a 1-bit analog-todigital converter (ADC with down-sampling is compared with that of a 10-bit ADC without down-sampling under multi-path fading conditions defined in LTE standard for user equipment (UE performance test. A high performance primary synchronization signal detection method is derived in this paper.

  9. Influence of Multi-Cascaded Semiconductor Optical Amplifiers on the Signal in an Energy-Efficient System

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-Yong; SHENG Xin-Zhi; WU Chong-Qing

    2012-01-01

    Signal impairment is experimentally studied by using the extinction ratio (ER),error bit rate (BER) and optical spectrum in a three-cascaded semiconductor optical amplifier (SOA ) setup.The signal with the ER of 13 dB and BER of < 10-9 is achieved after the signal passing through the cascaded SOAs.With the results obtained from the experiment,we confirm that the three-cascaded SOAs used to compensate for power in the optical transmission can be accepted.This experimental result also offers the possibility of achieving a higher throughput of multiplane architecture by exploiting three switching domains instead of two switching domains in the energy-efficient design of a scalable optical multi-plane interconnection architecture.The space switches in output ports of multi-plane interconnection architecture can be improved to N =32 x 32 x 32 =32768.%Signal impairment is experimentally studied by using the extinction ratio (ER), error bit rate (BER) and optical spectrum in a three-cascaded semiconductor optical amplifier (SOA) setup. The signal with the ER of 13 dB and BER of<10-9 is achieved after the signal passing through the cascaded SO As. With the results obtained from the experiment, we confirm that the three-cascaded SOAs used to compensate for power in the optical transmission can be accepted. This experimental result also offers the possibility of achieving a higher throughput of multi-plane architecture by exploiting three switching domains instead of two switching domains in the energy-efficient design of a scalable optical multi-plane interconnection architecture. The space switches in output ports of multi-plane interconnection architecture can be improved to N = 32 × 32 × 32 = 32768.

  10. Lead-Free Inverted Planar Formamidinium Tin Triiodide Perovskite Solar Cells Achieving Power Conversion Efficiencies up to 6.22%

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Weiqiang; Zhao, Dewei; Yu, Yue; Grice, Corey R.; Wang, Changlei; Cimaroli, Alexander J.; Schulz, Philip; Meng, Weiwei; Zhu, Kai; Xiong, Ren-Gen; Yan, Yanfa

    2016-11-09

    Efficient lead (Pb)-free inverted planar formamidinium tin triiodide (FASnI3) perovskite solar cells (PVSCs) are demonstrated. Our FASnI3 PVSCs achieved average power conversion efficiencies (PCEs) of 5.41% +/- 0.46% and a maximum PCE of 6.22% under forward voltage scan. The PVSCs exhibit small photocurrent-voltage hysteresis and high reproducibility. The champion cell showed a steady-state efficiency of almost equal to 6.00% for over 100 s.

  11. Efficient Bistatic SAR Raw Signal Simulator of Extended Scenes

    Directory of Open Access Journals (Sweden)

    Liang Yang

    2014-01-01

    Full Text Available Bistatic SAR system is a new mode that allocates the radar transmitter and receiver on different platforms and has more advantages compared to the monostatic case. However, the existing bistatic SAR raw data simulator in the frequency domain can only handle the case of translation invariant system. In this paper, an efficient 2D frequency-domain raw data simulator of extended scenes for bistatic SAR of translation variant system is proposed by a geometric transformation method for the first time, where inverse STOLT interpolation is used to formulate the range migration terms. The presented simulator can accommodate the translation variant bistatic SAR system compared with existing bistatic SAR simulator. And it is more efficient than the time domain one by making use of Fast Fourier Transform (FFT. Simulation results for point targets and a real SAR image demonstrate its validity and effectiveness.

  12. Efficient Bistatic SAR Raw Signal Simulator of Extended Scenes

    OpenAIRE

    Liang Yang; Weidong Yu; Shichao Zheng; Lei Zhang

    2014-01-01

    Bistatic SAR system is a new mode that allocates the radar transmitter and receiver on different platforms and has more advantages compared to the monostatic case. However, the existing bistatic SAR raw data simulator in the frequency domain can only handle the case of translation invariant system. In this paper, an efficient 2D frequency-domain raw data simulator of extended scenes for bistatic SAR of translation variant system is proposed by a geometric transformation method for the first t...

  13. Efficient noise cancellers for ECG signal enhancement for telecardiology applications

    Directory of Open Access Journals (Sweden)

    Nagesh MANTRAVADI

    2016-12-01

    Full Text Available In this paper some effective noise cancellers were proposed using the variants of Least Mean Fourth (LMF Algorithm to remove the artifacts that occur during the acquisition stage of an ECG signal. In order to accelerate the performance of the LMF algorithm we introduce data normalization in weight update process. This results two variants of LMF algorithm, called normalized LMF (NLMF and global NLMF (GNLMF algorithms. Further, to minimize their computational complexity and improve convergence characteristics, tracking ability, filtering capability we apply signum and block processing on the two versions of normalized algorithms. Both the two treatments results six more algorithms. Using these algorithms we develop various adaptive noise cancellers (ANCs. These ANCs are tested with the help of standard MIT-BIH arrhythmia database for various records. The Signal to noise ratio, Excess Mean Square Error and misadjustment are taken as performances measures to analyze the performance of proposed methods. These ANCs exhibit improved performance over the LMF based ANC.

  14. An Efficient Implementation of Generalized Delayed Signal Cancellation PLL

    DEFF Research Database (Denmark)

    Golestan, Saeed; Fernandez, Francisco Daniel Freijedo; Vidal, Ana;

    2016-01-01

    The phase, frequency, and amplitude of the fundamental-frequency positive-sequence component of the grid voltage are crucial information in control of most grid-connected power electronic based equipment. Often, a standard phaselocked loop (PLL) with a prefiltering stage is employed for the extra......The phase, frequency, and amplitude of the fundamental-frequency positive-sequence component of the grid voltage are crucial information in control of most grid-connected power electronic based equipment. Often, a standard phaselocked loop (PLL) with a prefiltering stage is employed...... for the extraction of them. Inspired by the concept of delayed signal cancellation (DSC), the generalized DSC (GDSC) operator has recently been introduced as an interesting option for the PLL prefiltering stage. In its typical structure, the GDSC operator extracts the grid fundamental component and feeds...

  15. Efficient Underground Object Detection for Ground Penetrating Radar Signals

    Directory of Open Access Journals (Sweden)

    Ibrahim Mesecan

    2016-12-01

    Full Text Available Ground penetrating radar (GPR is one of the common sensor system for underground inspection. GPR emits electromagnetic waves which can pass through objects. The reflecting waves are recorded and digitised, and then, the B-scan images are formed. According to the properties of scanning object, GPR creates higher or lower intensity values on the object regions. Thus, these changes in signal represent the properties of scanning object. This paper proposes a 3-step method to detect and discriminate landmines: n-row average-subtraction (NRAS; Min-max normalisation; and image scaling. Proposed method has been tested using 3 common algorithms from the literature. According to the results, it has increased object detection ratio and positive object discrimination (POD significantly. For artificial neural networks (ANN, POD has increased from 77.4 per cent to 87.7 per cent. And, it has increased from 37.8 per cent to 80.2 per cent, for support vector machines (SVM.

  16. Limits on Achievable Dimensional and Photon Efficiencies with Intensity-Modulation and Photon-Counting Due to Non-Ideal Photon-Counter Behavior

    Science.gov (United States)

    Moision, Bruce; Erkmen, Baris I.; Farr, William; Dolinar, Samuel J.; Birnbaum, Kevin M.

    2012-01-01

    An ideal intensity-modulated photon-counting channel can achieve unbounded photon information efficiencies (PIEs). However, a number of limitations of a physical system limit the practically achievable PIE. In this paper, we discuss several of these limitations and illustrate their impact on the channel. We show that, for the Poisson channel, noise does not strictly bound PIE, although there is an effective limit, as the dimensional information efficiency goes as e[overline] e PIE beyond a threshold PIE. Since the Holevo limit is bounded in the presence of noise, this illustrates that the Poisson approximation is invalid at large PIE for any number of noise modes. We show that a finite transmitter extinction ratio bounds the achievable PIE to a maximum that is logarithmic in the extinction ratio. We show how detector jitter limits the ability to mitigate noise in the PPM signaling framework. We illustrate a method to model detector blocking when the number of detectors is large, and illustrate mitigation of blocking with spatial spreading and altering. Finally, we illustrate the design of a high photon efficiency system using state-of-the-art photo-detectors and taking all these effects into account.

  17. Power-efficient method for IM-DD optical transmission of multiple OFDM signals.

    Science.gov (United States)

    Effenberger, Frank; Liu, Xiang

    2015-05-18

    We propose a power-efficient method for transmitting multiple frequency-division multiplexed (FDM) orthogonal frequency-division multiplexing (OFDM) signals in intensity-modulation direct-detection (IM-DD) optical systems. This method is based on quadratic soft clipping in combination with odd-only channel mapping. We show, both analytically and experimentally, that the proposed approach is capable of improving the power efficiency by about 3 dB as compared to conventional FDM OFDM signals under practical bias conditions, making it a viable solution in applications such as optical fiber-wireless integrated systems where both IM-DD optical transmission and OFDM signaling are important.

  18. Efficient Signal-Time Coding Design and its Application in Wireless Gaussian Relay Networks

    CERN Document Server

    Fan, Pingyi; Letaief, Khaled Ben

    2009-01-01

    Signal-time coding, which combines the traditional encoding/modulation mode in the signal domain with signal pulse phase modulation in the time domain, was proposed to improve the information flow rate in relay networks. In this paper, we mainly focus on the efficient signal-time coding design. We first derive an explicit iterative algorithm to estimate the maximum number of available codes given the code length of signal-time coding, and then present an iterative construction method of codebooks. It is shown that compared with conventional computer search, the proposed iterative construction method can reduce the complexity greatly. Numerical results will also indicate that the new constructed codebook is optimal in terms of coding rate. To minimize the buffer size needed to store the codebook while keeping a relatively high efficiency, we shall propose a combinatorial construction method. We will then consider applications in wireless Gaussian relay networks. It will be shown that in the three node network ...

  19. Black silicon solar cells with interdigitated back-contacts achieve 22.1% efficiency

    OpenAIRE

    Savin, Hele; Repo, Päivikki; Von Gastrow, Guillaume; Ortega, Pablo; Calle, Eric; Garín, Moises; Alcubilla, Ramon

    2015-01-01

    The nanostructuring of silicon surfaces—known as black silicon—is a promising approach to eliminate front-surface reflection in photovoltaic devices without the need for a conventional antireflection coating. This might lead to both an increase in efficiency and a reduction in the manufacturing costs of solar cells. However, all previous attempts to integrate black silicon into solar cells have resulted in cell efficiencies well below 20% due to the increased charge carrier recombination at t...

  20. O&M Best Practices - A Guide to Achieving Operational Efficiency (Release 2.0)

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Gregory P.; Pugh, Ray; Melendez, Aldo P.; Hunt, W. D.

    2004-07-31

    This guide, sponsored by DOE's Federal Energy Management Program, highlights operations and maintenance (O&M) programs targeting energy efficiency that are estimated to save 5% to 20% on energy bills without a significant capital investment. The purpose of this guide is to provide the federal O&M energy manager and practitioner with useful information about O&M management, technologies, energy efficiency and cost-reduction approaches.

  1. Black silicon solar cells with interdigitated back-contacts achieve 22.1% efficiency

    Science.gov (United States)

    Savin, Hele; Repo, Päivikki; von Gastrow, Guillaume; Ortega, Pablo; Calle, Eric; Garín, Moises; Alcubilla, Ramon

    2015-07-01

    The nanostructuring of silicon surfaces—known as black silicon—is a promising approach to eliminate front-surface reflection in photovoltaic devices without the need for a conventional antireflection coating. This might lead to both an increase in efficiency and a reduction in the manufacturing costs of solar cells. However, all previous attempts to integrate black silicon into solar cells have resulted in cell efficiencies well below 20% due to the increased charge carrier recombination at the nanostructured surface. Here, we show that a conformal alumina film can solve the issue of surface recombination in black silicon solar cells by providing excellent chemical and electrical passivation. We demonstrate that efficiencies above 22% can be reached, even in thick interdigitated back-contacted cells, where carrier transport is very sensitive to front surface passivation. This means that the surface recombination issue has truly been solved and black silicon solar cells have real potential for industrial production. Furthermore, we show that the use of black silicon can result in a 3% increase in daily energy production when compared with a reference cell with the same efficiency, due to its better angular acceptance.

  2. Black silicon solar cells with interdigitated back-contacts achieve 22.1% efficiency.

    Science.gov (United States)

    Savin, Hele; Repo, Päivikki; von Gastrow, Guillaume; Ortega, Pablo; Calle, Eric; Garín, Moises; Alcubilla, Ramon

    2015-07-01

    The nanostructuring of silicon surfaces--known as black silicon--is a promising approach to eliminate front-surface reflection in photovoltaic devices without the need for a conventional antireflection coating. This might lead to both an increase in efficiency and a reduction in the manufacturing costs of solar cells. However, all previous attempts to integrate black silicon into solar cells have resulted in cell efficiencies well below 20% due to the increased charge carrier recombination at the nanostructured surface. Here, we show that a conformal alumina film can solve the issue of surface recombination in black silicon solar cells by providing excellent chemical and electrical passivation. We demonstrate that efficiencies above 22% can be reached, even in thick interdigitated back-contacted cells, where carrier transport is very sensitive to front surface passivation. This means that the surface recombination issue has truly been solved and black silicon solar cells have real potential for industrial production. Furthermore, we show that the use of black silicon can result in a 3% increase in daily energy production when compared with a reference cell with the same efficiency, due to its better angular acceptance.

  3. How to achieve higher efficiency in waste treatment; Wege zur Effizienzsteigerung bei der Abfallbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, M. [Bauhaus-Univ. Weimar (Germany). Lehrstuhl Verfahren und Umwelt

    2007-07-01

    Many different suggestions have been made during the past few years on how to enhance efficiency. The contribution presents an outline and attempts a classification of measures best suited for existing plants and for new or modified plants. It starts by showing how to assess the initial state of a plant which provides the basis for the optimisations. (orig.)

  4. A Strategy to Achieve High-Efficiency Organolead Trihalide Perovskite Solar Cells

    Science.gov (United States)

    Andalibi, Shabnam; Rostami, Ali; Darvish, Ghafar; Moravvej-Farshi, Mohammad Kazem

    2016-11-01

    Recent theoretical and experimental reports have shown that organometal lead halide perovskite solar cells have attracted attention as a low-cost photovoltaic technology offering high power conversion efficiency. However, the photovoltaic efficiency of these materials is still limited by poor chemical and structural stability in the case of methylammonium lead triiodide and by large bandgap in the case of methylammonium lead tribromide or trichloride. To obtain high-performance devices, we have investigated the computationally optimal efficiency for these materials using the detailed-balance method and present optimal intermediate-band perovskite solar cells with high open-circuit voltage. We model different halide perovskites using density function theory calculations and study their bandgap and absorption coefficient. Based on calculation results, surprisingly Hg doping in different halide perovskites introduces a narrow partially filled intermediate band in the forbidden bandgap. We investigate electrical and optical properties of MAPb0.97Hg0.03I3, MAPb0.96Hg0.04Br3, and MAPb0.96Hg0.04Cl3 and calculate the high absorption efficiency of the different perovskite structures to create thin films suitable for photovoltaic devices.

  5. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    Science.gov (United States)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  6. Achieving energy efficiency in LTE with joint D2D communications and green networking techniques

    KAUST Repository

    Yaacoub, Elias E.

    2013-07-01

    In this paper, the joint operation of cooperative device-to-device (D2D) communications and green cellular communications is investigated. An efficient approach for grouping mobile terminals (MTs) into cooperative clusters is described. In each cluster, MTs cooperate via D2D communications to share content of common interest. Furthermore, an energy-efficient technique for putting BSs in sleep mode in an LTE cellular network is presented. Finally, both methods are combined in order to ensure green communications for both the users\\' MTs and the operator\\'s BSs. The studied methods are investigated in the framework of OFDMA-based state-of-the-art LTE cellular networks, while taking into account intercell interference and resource allocation. © 2013 IEEE.

  7. Identification of Energy Efficiency Opportunities through Building Data Analysis and Achieving Energy Savings through Improved Controls

    Energy Technology Data Exchange (ETDEWEB)

    Katipamula, Srinivas; Taasevigen, Danny J.; Koran, Bill

    2014-09-04

    This chapter will highlight analysis techniques to identify energy efficiency opportunities to improve operations and controls. A free tool, Energy Charting and Metrics (ECAM), will be used to assist in the analysis of whole-building, sub-metered, and/or data from the building automation system (BAS). Appendix A describes the features of ECAM in more depth, and also provide instructions for downloading ECAM and all resources pertaining to using ECAM.

  8. Efficient visual search from synchronized auditory signals requires transient audiovisual events.

    Directory of Open Access Journals (Sweden)

    Erik Van der Burg

    Full Text Available BACKGROUND: A prevailing view is that audiovisual integration requires temporally coincident signals. However, a recent study failed to find any evidence for audiovisual integration in visual search even when using synchronized audiovisual events. An important question is what information is critical to observe audiovisual integration. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrate that temporal coincidence (i.e., synchrony of auditory and visual components can trigger audiovisual interaction in cluttered displays and consequently produce very fast and efficient target identification. In visual search experiments, subjects found a modulating visual target vastly more efficiently when it was paired with a synchronous auditory signal. By manipulating the kind of temporal modulation (sine wave vs. square wave vs. difference wave; harmonic sine-wave synthesis; gradient of onset/offset ramps we show that abrupt visual events are required for this search efficiency to occur, and that sinusoidal audiovisual modulations do not support efficient search. CONCLUSIONS/SIGNIFICANCE: Thus, audiovisual temporal alignment will only lead to benefits in visual search if the changes in the component signals are both synchronized and transient. We propose that transient signals are necessary in synchrony-driven binding to avoid spurious interactions with unrelated signals when these occur close together in time.

  9. [Bariatric surgery is more efficient than medical treatment in achieving remission in diabetes mellitus type 2].

    Science.gov (United States)

    Klein, Mads; Rosenberg, Jacob; Gögenur, Ismail

    2013-04-01

    Observational studies have shown that bariatric surgery can lead to remission of diabetes mellitus type 2 (DMII), but randomized controlled trials have been lacking. Recently, randomized controlled trials comparing bariatric surgery with optimal medical treatment in patients suffering from poorly controlled DMII, have been performed. These trials show that bariatric surgery in general, and the malabsorptive procedures in particular, are more effective than medical treatment in achieving remission of DMII. These procedures should therefore be considered in the treatment of patients with DMII and obesity.

  10. Time domain zero-padding based adaptive-PAM signal transmission with high spectral efficiency in IMDD optical communication system

    Science.gov (United States)

    Zhang, Fangliu; He, Jing; Deng, Rui; Cheng, Yun; Xiao, Minlei; Chen, Lin

    2016-08-01

    In this paper, an adaptive pulse amplitude modulation (APAM) scheme is proposed and experimentally demonstrated in the intensity-modulation and direct-detection (IMDD) optical communications system. In the proposed scheme, the channel is divided into two sub-channels, and different PAM mapping can be chosen for different sub-channel according to the fading conditions. In addition, the 20-km standard single mode fiber (SSMF) transmission of 24 Gbit/s 16/4-APAM signal with the spectral efficiency (SE) up to 6 bit/s/Hz is experimentally demonstrated. The experiment results show that the bit error rate (BER) of the 16/4-APAM signal can be achieved less than 2.4e-2.

  11. Energy-Level Modulation of Small-Molecule Electron Acceptors to Achieve over 12% Efficiency in Polymer Solar Cells.

    Science.gov (United States)

    Li, Sunsun; Ye, Long; Zhao, Wenchao; Zhang, Shaoqing; Mukherjee, Subhrangsu; Ade, Harald; Hou, Jianhui

    2016-11-01

    Fine energy-level modulations of small-molecule acceptors (SMAs) are realized via subtle chemical modifications on strong electron-withdrawing end-groups. The two new SMAs (IT-M and IT-DM) end-capped by methyl-modified dicycanovinylindan-1-one exhibit upshifted lowest unoccupied molecular orbital (LUMO) levels, and hence higher open-circuit voltages can be observed in the corresponding devices. Finally, a top power conversion efficiency of 12.05% is achieved.

  12. Achieving efficiency in Africa: What are the priorities, the best practices and the policy measures?

    Energy Technology Data Exchange (ETDEWEB)

    Fall, Latsoucabe

    2010-09-15

    Energy Efficiency (EE) improvements offer huge opportunities for Africa to meet growing energy needs, secure a more sustainable energy supply and demand, improve business productivity, preserve local environment and mitigate GHG emissions. The paper focuses on the ways and means to overcome the related challenges in order to reap the benefits of such improvements. It also identifies the priorities for Africa and provides responses on how to establish and implement effective policy-measures to enhance EE in African countries. Subsequently, it delivers key recommendations to help improve EE policies and practices and to implement national and regional measures of EE improvements.

  13. Efficient signal processing for time-resolved fluorescence detection of nitrogen-vacancy spins in diamond

    Science.gov (United States)

    Gupta, A.; Hacquebard, L.; Childress, L.

    2016-03-01

    Room-temperature fluorescence detection of the nitrogen-vacancy center electronic spin typically has low signal to noise, requiring long experiments to reveal an averaged signal. Here, we present a simple approach to analysis of time-resolved fluorescence data that permits an improvement in measurement precision through signal processing alone. Applying our technique to experimental data reveals an improvement in signal to noise equivalent to a 14% increase in photon collection efficiency. We further explore the dependence of the signal to noise ratio on excitation power, and analyze our results using a rate equation model. Our results provide a rubric for optimizing fluorescence spin detection, which has direct implications for improving precision of nitrogen-vacancy-based sensors.

  14. Efficient Method of Achieving Agreements between Individuals and Organizations about RFID Privacy

    Science.gov (United States)

    Cha, Shi-Cho

    This work presents novel technical and legal approaches that address privacy concerns for personal data in RFID systems. In recent years, to minimize the conflict between convenience and the privacy risk of RFID systems, organizations have been requested to disclose their policies regarding RFID activities, obtain customer consent, and adopt appropriate mechanisms to enforce these policies. However, current research on RFID typically focuses on enforcement mechanisms to protect personal data stored in RFID tags and prevent organizations from tracking user activity through information emitted by specific RFID tags. A missing piece is how organizations can obtain customers' consent efficiently and flexibly. This study recommends that organizations obtain licenses automatically or semi-automatically before collecting personal data via RFID technologies rather than deal with written consents. Such digitalized and standard licenses can be checked automatically to ensure that collection and use of personal data is based on user consent. While individuals can easily control who has licenses and license content, the proposed framework provides an efficient and flexible way to overcome the deficiencies in current privacy protection technologies for RFID systems.

  15. India`s achievements in energy efficiency and reducing CO{sub 2} emissions

    Energy Technology Data Exchange (ETDEWEB)

    Pachauri, R.k.; Sharma, S. [Tata Energy Research Institute, New Delhi (India)

    1999-08-01

    Energy plays a central role in India`s development efforts and its mandate to alleviate poverty. For this reasons, promoting energy efficiency, conservation, and renewable energy technologies are key aspects of India`s development objectives. Although overall energy use is expected to continue to rise along with India`s population and GDP, government initiatives and policies, particularly since 1990, are affecting India`s CO{sub 2} emission intensity (emission from energy use per unit GDP), which has levelled off and shows signs of declining. Energy efficiency has shown improvement as well, in large part because of a change in pricing structures and a reduction of energy subsidies. India`s promotion of renewable energy, especially for rural areas, represents another significant action to limit greenhouse gases (GHGs). Though India, like other developing countries, has not taken on specific commitments to mitigate CO{sub 2} emissions, it is making progress in this direction. 6 refs., 7 figs., 5 tabs.

  16. AUDIT FUNCTION ROLE IN ACHIEVING AN EFFICIENT CORPORATE GOVERNANCE – CONCEPTUAL MODEL PROPOSAL

    Directory of Open Access Journals (Sweden)

    Melinda Timea Fülöp

    2013-12-01

    Full Text Available Nowadays corporate governance plays an important role in decisions making processes, which represents a relatively new approach for both Romanian scientific studies and practice. As a consequence we consider the increased attention given to corporate governance to be crucial, especially addressing the role of the audit function and the importance of the corporate governance code. Audit function is of particular practical importance in corporate governance, therefore we decided meticulously to consider it, and especially to develop a conceptual framework for its role in support of an effective corporate governance. We consider that there are two levels and seven key elements utilized in order to achieve an effective corporate governance. In conclusion, audit function as a whole, with an active role in improving corporate governance, should perform correlated in terms of its components: internal audit, external audit and audit committees.

  17. Metering Best Practices, A Guide to Achieving Utility Resource Efficiency, Release 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Greg; Hunt, W. D.; Pugh, Ray; Sandusky, William F.; Koehler, Theresa M.; Boyd, Brian K.

    2011-08-31

    This release is an update and expansion of the information provided in Release 1.0 of the Metering Best Practice Guide that was issued in October 2007. This release, as was the previous release, was developed under the direction of the U.S. Department of Energy's Federal Energy Management Program (FEMP). The mission of FEMP is to facilitate the Federal Government's implementation of sound cost-effective energy management and investment practices to enhance the nation's energy security and environmental stewardship. Each of these activities is directly related to achieving requirements set forth in the Energy Policy Acts of 1992 and 2005, the Energy Independence and Security Act (EISA) of 2007, and the goals that have been established in Executive Orders 13423 and 13514 - and also those practices that are inherent in sound management of Federal financial and personnel resources.

  18. RESEARCHES CONCERNING THE ECONOMIC EFFICIENCY ACHIEVED SUCCESSIVE TO THE APPLICATION OF BIOLOGICALLY-ACTIVE PRODUCTS IN SMOOTH BROME CROP

    Directory of Open Access Journals (Sweden)

    ELENA PEł

    2013-12-01

    Full Text Available Within any branch of material production, the supervision of the economic effects caused by the applied technologies is an essential requirement. Not only related to the productive activity, but also related to scientific research, designing and other fields of activity, the final goal is represented by the achievement of immediate or far off economic effects. The introduction and generalization into production of the newest technologies of forage production must rely upon calculations of economic efficiency, too. The objective of these calculations is to offer to any producer the possibility to choose among the optimal technologic variants, with great productions per surface unit, of high quality and low costs. The calculations of economic efficiency were carried out during the three years of experimentation. The economic efficiency obtained after the application of biostimulants in smooth brome during the first year of production is expressed through the achievement of a profit per surface unit of 75.85 – 127.00 €/ha. Successive to the calculations of economic efficiency, during the second year of production, the profit per surface unit recorded values between 79.10 – 153.10 €/ha depending upon the applied biostimulant, and during the third year of production the profit obtained per surface unit was 211.05 – 270.70 €/ha.

  19. Operations & Maintenance Best Practices - A Guide to Achieving Operational Efficiency (Release 3)

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Greg; Pugh, Ray; Melendez, Aldo P.; Hunt, W. D.

    2010-08-04

    This guide highlights operations and maintenance programs targeting energy and water efficiency that are estimated to save 5% to 20% on energy bills without a significant capital investment. The purpose of this guide is to provide you, the Operations and Maintenance (O&M)/Energy manager and practitioner, with useful information about O&M management, technologies, energy and water efficiency, and cost-reduction approaches. To make this guide useful and to reflect your needs and concerns, the authors met with O&M and Energy managers via Federal Energy Management Program (FEMP) workshops. In addition, the authors conducted extensive literature searches and contacted numerous vendors and industry experts. The information and case studies that appear in this guide resulted from these activities. It needs to be stated at the outset that this guide is designed to provide information on effective O&M as it applies to systems and equipment typically found at Federal facilities. This guide is not designed to provide the reader with step-by-step procedures for performing O&M on any specific piece of equipment. Rather, this guide first directs the user to the manufacturer's specifications and recommendations. In no way should the recommendations in this guide be used in place of manufacturer's recommendations. The recommendations in this guide are designed to supplement those of the manufacturer, or, as is all too often the case, provide guidance for systems and equipment for which all technical documentation has been lost. As a rule, this guide will first defer to the manufacturer's recommendations on equipment operation and maintenance.

  20. Efficient Sparse Signal Transmission over a Lossy Link Using Compressive Sensing.

    Science.gov (United States)

    Wu, Liantao; Yu, Kai; Cao, Dongyu; Hu, Yuhen; Wang, Zhi

    2015-08-13

    Reliable data transmission over lossy communication link is expensive due to overheads for error protection. For signals that have inherent sparse structures, compressive sensing (CS) is applied to facilitate efficient sparse signal transmissions over lossy communication links without data compression or error protection. The natural packet loss in the lossy link is modeled as a random sampling process of the transmitted data, and the original signal will be reconstructed from the lossy transmission results using the CS-based reconstruction method at the receiving end. The impacts of packet lengths on transmission efficiency under different channel conditions have been discussed, and interleaving is incorporated to mitigate the impact of burst data loss. Extensive simulations and experiments have been conducted and compared to the traditional automatic repeat request (ARQ) interpolation technique, and very favorable results have been observed in terms of both accuracy of the reconstructed signals and the transmission energy consumption. Furthermore, the packet length effect provides useful insights for using compressed sensing for efficient sparse signal transmission via lossy links.

  1. Efficient Sparse Signal Transmission over a Lossy Link Using Compressive Sensing

    Directory of Open Access Journals (Sweden)

    Liantao Wu

    2015-08-01

    Full Text Available Reliable data transmission over lossy communication link is expensive due to overheads for error protection. For signals that have inherent sparse structures, compressive sensing (CS is applied to facilitate efficient sparse signal transmissions over lossy communication links without data compression or error protection. The natural packet loss in the lossy link is modeled as a random sampling process of the transmitted data, and the original signal will be reconstructed from the lossy transmission results using the CS-based reconstruction method at the receiving end. The impacts of packet lengths on transmission efficiency under different channel conditions have been discussed, and interleaving is incorporated to mitigate the impact of burst data loss. Extensive simulations and experiments have been conducted and compared to the traditional automatic repeat request (ARQ interpolation technique, and very favorable results have been observed in terms of both accuracy of the reconstructed signals and the transmission energy consumption. Furthermore, the packet length effect provides useful insights for using compressed sensing for efficient sparse signal transmission via lossy links.

  2. Efficient Low-Sensitivity Sampling of Multiband Signals with Bounded Components

    CERN Document Server

    Selva, J

    2010-01-01

    This paper presents an efficient method to sample multiband signals with bounded components, at a rate below the Nyquist limit, while keeping at the same time the numerical sensitivity at a low level. The method is based on band-limited windowing, followed by trigonometric approximation in consecutive time intervals. The key point is that the trigonometric approximation "inherits" the multiband property, that is, its coefficients are formed by bursts of non-zero elements corresponding to the multiband components. It is shown that this method can be well combined with the recently proposed synchronous multi-rate sampling (SMRS) scheme, given that the resulting linear system is sparse and formed by ones and zeroes. The proposed method allows one to trade sampling efficiency for noise sensitivity, and is specially well suited for bounded signals with unbounded energy like those in communications, navigation, audio systems, etc. Besides, it is also applicable to finite energy signals and periodic band-limited sig...

  3. The tzero electric sports car : how electric vehicles can achieve both high performance and high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, A.N.; Gage, T.B. [AC Propulsion, San Dimas, CA (United States)

    2000-07-01

    The development of a high-performance electric sports car by AC Propulsion was described along with a status report on the progress in developing the product-certified version. The development of the tzero car began in 1996. In-use testing and safety certification of prototypes is currently underway. The tzero is powered by a high-performance induction motor operated at 37 per cent higher peak current than allowed in a standard system since periods of peak power are limited to only a few seconds. The car, which can accelerate from 0 to 60 mph in 4.1 seconds, is considered to be one of the most energy-efficient cars on the road. Since the tzero will likely be sold without subsidy and since the market size for the tzero is expected to be small, in the order of 1000 units per year, it will have to be sold at a high enough price to cover the costs of small-volume production. AC Propulsion is hopeful that it may even be the first electric vehicle to be sold at a profit. Its technology and image are expected to present examples for other electric vehicles. The paper also included a comprehensive technical description of the car and its systems, such as the power electronics unit, traction converter, charger, auxiliary power supply, 12V battery, recharge interface, battery pack, battery modules and powertrain control. 4 tabs., 15 figs.

  4. Depth filters containing diatomite achieve more efficient particle retention than filters solely containing cellulose fibers

    Directory of Open Access Journals (Sweden)

    Johannes Felix Buyel

    2015-12-01

    Full Text Available The clarification of biological feed stocks during the production of biopharmaceutical proteins is challenging when large quantities of particles must be removed, e.g. when processing crude plant extracts. Single-use depth filters are often preferred for clarification because they are simple to integrate and have a good safety profile. However, the combination of filter layers must be optimized in terms of nominal retention ratings to account for the unique particle size distribution in each feed stock. We have recently shown that predictive models can facilitate filter screening and the selection of appropriate filter layers. Here we expand our previous study by testing several filters with different retention ratings. The filters typically contain diatomite to facilitate the removal of fine particles. However, diatomite can interfere with the recovery of large biopharmaceutical molecules such as virus-like particles and aggregated proteins. Therefore, we also tested filtration devices composed solely of cellulose fibers and cohesive resin. The capacities of both filter types varied from 10 to 50 L m-2 when challenged with tobacco leaf extracts, but the filtrate turbidity was ~500-fold lower (~3.5 NTU when diatomite filters were used. We also tested pre coat filtration with dispersed diatomite, which achieved capacities of up to 120 L m-2 with turbidities of ~100 NTU using bulk plant extracts, and in contrast to the other depth filters did not require an upstream bag filter. Single pre-coat filtration devices can thus replace combinations of bag and depth filters to simplify the processing of plant extracts, potentially saving on time, labor and consumables. The protein concentrations of TSP, DsRed and antibody 2G12 were not affected by pre-coat filtration, indicating its general applicability during the manufacture of plant-derived biopharmaceutical proteins.

  5. An attempt to achieve efficient energy design for High-Income Houses in Egypt

    Directory of Open Access Journals (Sweden)

    Kareem Mohamed Aldali

    2016-12-01

    Full Text Available Taking into consideration the economic status in Egypt in recent years, especially the investment sector will demonstrate the enormous increase in the residential buildings sector, which created massive energy consumption that never was in proportion with the growth in generated power in Egypt. As the residential sector consumes around 42.3% of the total energy used in Egypt, one of the main factors that waste that energy is artificial lighting and electric ventilation. Meanwhile, the architects who design those building never pay the enough attention to the energy in the design process. This paper tackles many strategies for the environmental control of building designs besides showing that now, it is essential to take into consideration energy performance efficiency and the compatibility of the building with the environment by optimizing the design of the building envelope elements such as a window to wall ratio (WWR, the glazing type. This paper will not cover the details of construction and structure, but it sheds light on many guidelines to help to raise the thermal and environmental quality of the envelope of the building. A computer-based simulation tool (Autodesk Ecotect was used to measure current building energy and lighting performance in one of the modern cities like Madenaty city. By the end of this study, some of the characteristics of the building envelope will be concluded like the window wall ratio in the aim to reduce the energy waste in the case study, as well as the different criteria of designing process for residential buildings in Egypt in the near future.

  6. ITC SOLUTIONS TO ACHIEVE PERFORMANCE AND EFFICIENCY OF HEALTH SERVICES: ONLINE VIRTUAL CLINIC

    Directory of Open Access Journals (Sweden)

    Adina BĂLAN

    2010-01-01

    Full Text Available The digital era modified the way people work, how the information and the informational resources are defined and organized. The organization which holds, uses and correctly reproduces the piece of information, the knowledge, the intellectual capital, becomes a leader in the proper field of activity. Following the actual tendencies in the digital era connected to the exchange of professional information, I can say that the exchange and sharing of digital information in a global multitude of interconnected computers are essential instruments that can contribute to the development and consolidation of the intellectual potential of the organization. This is why, the access of the individuals to information is an actual requirement of the development of the Romanian society in the context of globalization and world implication o contemporary processes and phenomena. The Digital integration eliminates the barriers that traditionally suppress the circuit of the medical information, lets the goods and services circulate to and from Romania by promoting efficiency as final purpose. Performance is needed in the health system, the transformation of the system of medical services by bringing the benefits of the medical science and technology to all individuals from every community. In order to accomplish these expectations it is needed that all the components that form the health system look at it as a whole and subscribe to modern solutions for improvement so that the quality of health should raise to an unprecedented level. Even if health systems differ from country to country from the organizational and financial point of view, they face the same challenges and problems, respectively the supply of medical care of better quality and keeping under control the health expenses. The use of information and communication technology in the field of medical assistance in order to stock, share, transmit and analyze clinical data and knowledge is more necessary

  7. Time lens based optical fourier transformation for advanced processing of spectrally-efficient OFDM and N-WDM signals

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Morioka, Toshio

    2016-01-01

    We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals.......We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals....

  8. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael;

    2009-01-01

    using switch-mode power amplifier aided by various linearization techniques can present a feasible way to achieve both high linearity and high power efficiency. In this paper two different implementations of the switch-mode power amplifier a re p resented for varying envelop applications: the RF pulse...

  9. Workshop Summary Proceedings Document: G7 Alliance on Resource Efficiency: U.S.-hosted Workshop on the Use of Life Cycle Concepts in Supply Chain Management to Achieve Resource Efficiency

    Science.gov (United States)

    This proceedings document summarizes prepared remarks, presentations and discussions from the G7 Alliance on Resource Efficiency: U.S.-hosted Workshop on the Use of Life Cycle Concepts in Supply Chain Management to Achieve Resource Efficiency.

  10. High efficiency processing for reduced amplitude zones detection in the HRECG signal

    Science.gov (United States)

    Dugarte, N.; Álvarez, A.; Balacco, J.; Mercado, G.; Gonzalez, A.; Dugarte, E.; Olivares, A.

    2016-04-01

    Summary - This article presents part of a more detailed research proposed in the medium to long term, with the intention of establishing a new philosophy of electrocardiogram surface analysis. This research aims to find indicators of cardiovascular disease in its early stage that may go unnoticed with conventional electrocardiography. This paper reports the development of a software processing which collect some existing techniques and incorporates novel methods for detection of reduced amplitude zones (RAZ) in high resolution electrocardiographic signal (HRECG).The algorithm consists of three stages, an efficient processing for QRS detection, averaging filter using correlation techniques and a step for RAZ detecting. Preliminary results show the efficiency of system and point to incorporation of techniques new using signal analysis with involving 12 leads.

  11. High Efficient Quantum Key Distribution by Random Using Classified Signal Coherent States

    Institute of Scientific and Technical Information of China (English)

    XI Jing-Bo; FANG Xi-Ming

    2006-01-01

    The decoy-state method is a useful method in resisting the attacks on quantum key distribution. However, how to choose the intensities of decoy states and the ratio of the decoy states and the signal state is still an open question. We present a simple formula to analyse the problem. We also give a simple method to derive the bounds of the necessary counting rates and quantum bit error rates for BB84 and SARG04; the latter was previously proposed by Scarani et al. [Phys. Rev. Lett. 92 (2004) 057901] We then propose a multi-signal-state method which employs different coherent states either as the decoy state or as the signal state to carry out quantum key distribution. We find our protocol more efficient and feasible.

  12. An Efficient Method to Identify Conditionally Activated Transcription Factors and their Corresponding Signal Transduction Pathway Segments

    Directory of Open Access Journals (Sweden)

    Haiyan Hu

    2009-11-01

    Full Text Available A signal transduction pathway (STP is a cascade composed of a series of signal transferring steps, which often activate one or more transcription factors (TFs to control the transcription of target genes. Understanding signaling pathways is important to our understanding of the molecular mechanisms of disease. Many condition-annotated pathways have been deposited in public databases. However, condition-annotated pathways are far from complete, considering the large number of possible conditions. Computational methods to assist in the identification of conditionally activated pathways are greatly needed. In this paper, we propose an efficient method to identify conditionally activated pathway segments starting from the identification of conditionally activated TFs, by incorporating protein-DNA binding data, gene expression data and protein interaction data. Applying our methods on several microarray datasets, we have discovered many significantly activated TFs and their corresponding pathway segments, which are supported by evidence in the literature.

  13. Efficient retina formation requires suppression of both Activin and BMP signaling pathways in pluripotent cells

    Directory of Open Access Journals (Sweden)

    Kimberly A. Wong

    2015-03-01

    Full Text Available Retina formation requires the correct spatiotemporal patterning of key regulatory factors. While it is known that repression of several signaling pathways lead to specification of retinal fates, addition of only Noggin, a known BMP antagonist, can convert pluripotent Xenopus laevis animal cap cells to functional retinal cells. The aim of this study is to determine the intracellular molecular events that occur during this conversion. Surprisingly, blocking BMP signaling alone failed to mimic Noggin treatment. Overexpressing Noggin in pluripotent cells resulted in a concentration-dependent suppression of both Smad1 and Smad2 phosphorylation, which act downstream of BMP and Activin signaling, respectively. This caused a decrease in downstream targets: endothelial marker, xk81, and mesodermal marker, xbra. We treated pluripotent cells with dominant-negative receptors or the chemical inhibitors, dorsomorphin and SB431542, which each target either the BMP or Activin signaling pathway. We determined the effect of these treatments on retina formation using the Animal Cap Transplant (ACT assay; in which treated pluripotent cells were transplanted into the eye field of host embryos. We found that inhibition of Activin signaling, in the presence of BMP signaling inhibition, promotes efficient retinal specification in Xenopus tissue, mimicking the affect of adding Noggin alone. In whole embryos, we found that the eye field marker, rax, expanded when adding both dominant-negative Smad1 and Smad2, as did treating the cells with both dorsomorphin and SB431542. Future studies could translate these findings to a mammalian culture assay, in order to more efficiently produce retinal cells in culture.

  14. Nonlinear optical signal processing for high-speed, spectrally efficient fiber optic systems and networks

    Science.gov (United States)

    Zhang, Bo

    The past decade has witnessed astounding boom in telecommunication network traffic. With the emergence of multimedia over Internet, the high-capacity optical transport systems have started to shift focus from the core network towards the end users. This trend leads to diverse optical networks with transparency and reconfigurability requirement. As single channel data rate continues to increase and channel spacing continues to shrink for high capacity, high spectral efficiency, the workload on conventional electronic signal processing elements in the router nodes continues to build up. Performing signal processing functions in the optical domain can potentially alleviate the speed bottleneck if the unique optical properties are efficiently leveraged to assist electronic processing methodologies. Ultra-high bandwidth capability along with the promise for multi-channel and format-transparent operation make optical signal processing an attractive technology which is expected to have great impact on future optical networks. For optical signal processing applications in fiber-optic network and systems, a laudable goal would be to explore the unique nonlinear optical processes in novel photonic devices. This dissertation investigates novel optical signal processing techniques through simulations and experimental demonstrations, analyzes limitations of these nonlinear processing elements and proposes techniques to enhance the system performance or designs for functional photonic modules. Two key signal-processing building blocks for future optical networks, namely slow-light-based tunable optical delay lines and SOA-based high-speed wavelength converters, are presented in the first part of the dissertation. Phase preserving and spectrally efficient slow light are experimentally demonstrated using advanced modulation formats. Functional and novel photonic modules, such as multi-channel synchronizer and variable-bit-rate optical time division multiplexer are designed and

  15. Energy-Efficient Crowdsensing of Human Mobility and Signal Levels in Cellular Networks.

    Science.gov (United States)

    Foremski, Paweł; Gorawski, Michał; Grochla, Krzysztof; Polys, Konrad

    2015-09-02

    The paper presents a practical application of the crowdsensing idea to measure human mobility and signal coverage in cellular networks. Currently, virtually everyone is carrying a mobile phone, which may be used as a sensor to gather research data by measuring, e.g., human mobility and radio signal levels. However, many users are unwilling to participate in crowdsensing experiments. This work begins with the analysis of the barriers for engaging people in crowdsensing. A survey showed that people who agree to participate in crowdsensing expect a minimum impact on their battery lifetime and phone usage habits. To address these requirements, this paper proposes an application for measuring the location and signal strength data based on energy-efficient GPS tracking, which allows one to perform the measurements of human mobility and radio signal levels with minimum energy utilization and without any engagement of the user. The method described combines measurements from the accelerometer with effective management of the GPS to monitor the user mobility with the decrease in battery lifetime by approximately 20%. To show the applicability of the proposed platform, the sample results of signal level distribution and coverage maps gathered for an LTE network and representing human mobility are shown.

  16. Efficient endoderm induction from human pluripotent stem cells by logically directing signals controlling lineage bifurcations.

    Science.gov (United States)

    Loh, Kyle M; Ang, Lay Teng; Zhang, Jingyao; Kumar, Vibhor; Ang, Jasmin; Auyeong, Jun Qiang; Lee, Kian Leong; Choo, Siew Hua; Lim, Christina Y Y; Nichane, Massimo; Tan, Junru; Noghabi, Monireh Soroush; Azzola, Lisa; Ng, Elizabeth S; Durruthy-Durruthy, Jens; Sebastiano, Vittorio; Poellinger, Lorenz; Elefanty, Andrew G; Stanley, Edouard G; Chen, Qingfeng; Prabhakar, Shyam; Weissman, Irving L; Lim, Bing

    2014-02-01

    Human pluripotent stem cell (hPSC) differentiation typically yields heterogeneous populations. Knowledge of signals controlling embryonic lineage bifurcations could efficiently yield desired cell types through exclusion of alternate fates. Therefore, we revisited signals driving induction and anterior-posterior patterning of definitive endoderm to generate a coherent roadmap for endoderm differentiation. With striking temporal dynamics, BMP and Wnt initially specified anterior primitive streak (progenitor to endoderm), yet, 24 hr later, suppressed endoderm and induced mesoderm. At lineage bifurcations, cross-repressive signals separated mutually exclusive fates; TGF-β and BMP/MAPK respectively induced pancreas versus liver from endoderm by suppressing the alternate lineage. We systematically blockaded alternate fates throughout multiple consecutive bifurcations, thereby efficiently differentiating multiple hPSC lines exclusively into endoderm and its derivatives. Comprehensive transcriptional and chromatin mapping of highly pure endodermal populations revealed that endodermal enhancers existed in a surprising diversity of "pre-enhancer" states before activation, reflecting the establishment of a permissive chromatin landscape as a prelude to differentiation.

  17. Cycling excitation process: An ultra efficient and quiet signal amplification mechanism in semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yu-Hsin [Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0418 (United States); Yan, Lujiang; Zhang, Alex Ce; Hall, David; Niaz, Iftikhar Ahmad; Zhou, Yuchun [Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0409 (United States); Sham, L. J. [Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States); Lo, Yu-Hwa, E-mail: ylo@ucsd.edu [Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0418 (United States); Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0409 (United States)

    2015-08-03

    Signal amplification, performed by transistor amplifiers with its merit rated by the efficiency and noise characteristics, is ubiquitous in all electronic systems. Because of transistor thermal noise, an intrinsic signal amplification mechanism, impact ionization was sought after to complement the limits of transistor amplifiers. However, due to the high operation voltage (30-200 V typically), low power efficiency, limited scalability, and, above all, rapidly increasing excess noise with amplification factor, impact ionization has been out of favor for most electronic systems except for a few applications such as avalanche photodetectors and single-photon Geiger detectors. Here, we report an internal signal amplification mechanism based on the principle of the phonon-assisted cycling excitation process (CEP). Si devices using this concept show ultrahigh gain, low operation voltage, CMOS compatibility, and, above all, quantum limit noise performance that is 30 times lower than devices using impact ionization. Established on a unique physical effect of attractive properties, CEP-based devices can potentially revolutionize the fields of semiconductor electronics.

  18. A highly efficient surface plasmon polaritons excitation achieved with a metal-coupled metal-insulator-metal waveguide

    Directory of Open Access Journals (Sweden)

    Hongyan Yang

    2014-12-01

    Full Text Available We propose a novel metal-coupled metal-insulator-metal (MC-MIM waveguide which can achieve a highly efficient surface plasmon polaritons (SPPs excitation. The MC-MIM waveguide is formed by inserting a thin metal film in the insulator of an MIM. The introduction of the metal film, functioning as an SPPs coupler, provides a space for the interaction between SPPs and a confined electromagnetic field of the intermediate metal surface, which makes energy change and phase transfer in the metal-dielectric interface, due to the joint action of incomplete electrostatic shielding effect and SPPs coupling. Impacts of the metal film with different materials and various thickness on SPPs excitation are investigated. It is shown that the highest efficient SPPs excitation is obtained when the gold film thickness is 60 nm. The effect of refractive index of upper and lower symmetric dielectric layer on SPPs excitation is also discussed. The result shows that the decay value of refractive index is 0.3. Our results indicate that this proposed MC-MIM waveguide may offer great potential in designing a new SPPs source.

  19. A 12%-efficient upgraded metallurgical grade silicon-organic heterojunction solar cell achieved by a self-purifying process.

    Science.gov (United States)

    Zhang, Jie; Song, Tao; Shen, Xinlei; Yu, Xuegong; Lee, Shuit-Tong; Sun, Baoquan

    2014-11-25

    Low-quality silicon such as upgraded metallurgical-grade (UMG) silicon promises to reduce the material requirements for high-performance cost-effective photovoltaics. So far, however, UMG silicon currently exhibits the short diffusion length and serious charge recombination associated with high impurity levels, which hinders the performance of solar cells. Here, we used a metal-assisted chemical etching (MACE) method to partially upgrade the UMG silicon surface. The silicon was etched into a nanostructured one by the MACE process, associated with removing impurities on the surface. Meanwhile, nanostructured forms of UMG silicon can benefit improved light harvesting with thin substrates, which can relax the requirement of material purity for high photovoltaic performance. In order to suppress the large surface recombination due to increased surface area of nanostructured UMG silicon, a post chemical treatment was used to decrease the surface area. A solution-processed conjugated polymer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was deposited on UMG silicon at low temperature (silicon substrate. By optimizing the thickness of silicon and suppressing the charge recombination at the interface between thin UMG silicon/PEDOT:PSS, we are able to achieve 12.0%-efficient organic-inorganic hybrid solar cells, which are higher than analogous UMG silicon devices. We show that the modified UMG silicon surface can increase the minority carrier lifetime because of reduced impurity and surface area. Our results suggest a design rule for an efficient silicon solar cell with low-quality silicon absorbers.

  20. Efficient Techniques of Sparse Signal Analysis for Enhanced Recovery of Information in Biomedical Engineering and Geosciences

    KAUST Repository

    Sana, Furrukh

    2016-11-01

    Sparse signals are abundant among both natural and man-made signals. Sparsity implies that the signal essentially resides in a small dimensional subspace. The sparsity of the signal can be exploited to improve its recovery from limited and noisy observations. Traditional estimation algorithms generally lack the ability to take advantage of signal sparsity. This dissertation considers several problems in the areas of biomedical engineering and geosciences with the aim of enhancing the recovery of information by exploiting the underlying sparsity in the problem. The objective is to overcome the fundamental bottlenecks, both in terms of estimation accuracies and required computational resources. In the first part of dissertation, we present a high precision technique for the monitoring of human respiratory movements by exploiting the sparsity of wireless ultra-wideband signals. The proposed technique provides a novel methodology of overcoming the Nyquist sampling constraint and enables robust performance in the presence of noise and interferences. We also present a comprehensive framework for the important problem of extracting the fetal electrocardiogram (ECG) signals from abdominal ECG recordings of pregnant women. The multiple measurement vectors approach utilized for this purpose provides an efficient mechanism of exploiting the common structure of ECG signals, when represented in sparse transform domains, and allows leveraging information from multiple ECG electrodes under a joint estimation formulation. In the second part of dissertation, we adopt sparse signal processing principles for improved information recovery in large-scale subsurface reservoir characterization problems. We propose multiple new algorithms for sparse representation of the subsurface geological structures, incorporation of useful prior information in the estimation process, and for reducing computational complexities of the problem. The techniques presented here enable significantly

  1. Efficient Multiple Description Scalable Video Coding Scheme Based on Weighted Signal Combinations

    Institute of Scientific and Technical Information of China (English)

    ZHAO Anbang; WANG Wensheng; CUI Huijuan; TANG Kun

    2007-01-01

    A simple, efficient multiple description coding (MDC) algorithm was developed based on weighted signal combinations. The scheme uses the standard video encoder with a pre-processing stage to generate multiple descriptions.The decoder then uses a post-proprocessing stage to generate multiple descriptions. The decoder then uses a post-processing algorithm to combine the descriptions to provide better image quality. A scalable codec in the MDC system allows the system to provide multiple descriptions and scalability at the same time. In addition, since the different scalable descriptions may have different qualities, a simple averaging process is not optimal. An optimal weighted combination of the two descriptions was developed based on the signal to noise ratios. Compared with the simple average combination, the algorithm significantly improved the video quality, especially with large quality differences between the two descriptions, with gains of up to 3.56 dB.

  2. Computationally efficient locally-recurrent neural networks for online signal processing

    CERN Document Server

    Hussain, A; Shim, I

    1999-01-01

    A general class of computationally efficient locally recurrent networks (CERN) is described for real-time adaptive signal processing. The structure of the CERN is based on linear-in-the- parameters single-hidden-layered feedforward neural networks such as the radial basis function (RBF) network, the Volterra neural network (VNN) and the functionally expanded neural network (FENN), adapted to employ local output feedback. The corresponding learning algorithms are derived and key structural and computational complexity comparisons are made between the CERN and conventional recurrent neural networks. Two case studies are performed involving the real- time adaptive nonlinear prediction of real-world chaotic, highly non- stationary laser time series and an actual speech signal, which show that a recurrent FENN based adaptive CERN predictor can significantly outperform the corresponding feedforward FENN and conventionally employed linear adaptive filtering models. (13 refs).

  3. A Few Photons Among Many: Unmixing Signal and Noise for Photon-Efficient Active Imaging

    CERN Document Server

    Rapp, Joshua

    2016-01-01

    Conventional LIDAR systems require hundreds or thousands of photon detections to form accurate depth and reflectivity images. Recent photon-efficient computational imaging methods are remarkably effective with only 1.0 to 3.0 detected photons per pixel, but they are not demonstrated at signal-to-background ratio (SBR) below 1.0 because their imaging accuracies degrade significantly in the presence of high background noise. We introduce a new approach to depth and reflectivity estimation that focuses on unmixing contributions from signal and noise sources. At each pixel in an image, short-duration range gates are adaptively determined and applied to remove detections likely to be due to noise. For pixels with too few detections to perform this censoring accurately, we borrow data from neighboring pixels to improve depth estimates, where the neighborhood formation is also adaptive to scene content. Algorithm performance is demonstrated on experimental data at varying levels of noise. Results show improved perfo...

  4. Efficiency of dispersive wave generation from a dual-frequency beat signal

    CERN Document Server

    Webb, K E; Xu, Y Q; Genty, G; Murdoch, S G

    2016-01-01

    The emission of dispersive waves (DWs) by temporal solitons can be described as a cascaded four-wave mixing process triggered by a pair of monochromatic continuous waves (CWs). We report experimental and numerical results demonstrating that the efficiency of this process is strongly and non-trivially affected by the frequency detuning of the CW pump lasers. We explain our results by showing that individual cycles of the input dual-frequency beat signal can evolve as higher-order solitons whose temporal compression and soliton fission govern the DW efficiency. Analytical predictions based on the detuning dependence of the soliton order are shown to be in excellent agreement with experimental and numerical observations.

  5. Efficient transmission of subthreshold signals in complex networks of spiking neurons

    CERN Document Server

    Torres, Joaquin J; Marro, J

    2014-01-01

    We investigate the efficient transmission and processing of weak signals (subthreshold) in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances - that naturally balances the network with excitatory and inhibitory synapses - and considering short-term synaptic plasticity affecting such conductances, we found different dynamical phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron and increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases and therefore for quite well defined and different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite ro...

  6. Efficient ECG signal analysis using wavelet technique for arrhythmia detection: an ANFIS approach

    Science.gov (United States)

    Khandait, P. D.; Bawane, N. G.; Limaye, S. S.

    2010-02-01

    This paper deals with improved ECG signal analysis using Wavelet Transform Techniques and employing subsequent modified feature extraction for Arrhythmia detection based on Neuro-Fuzzy technique. This improvement is based on suitable choice of features in evaluating and predicting life threatening Ventricular Arrhythmia . Analyzing electrocardiographic signals (ECG) includes not only inspection of P, QRS and T waves, but also the causal relations they have and the temporal sequences they build within long observation periods. Wavelet-transform is used for effective feature extraction and Adaptive Neuro-Fuzzy Inference System (ANFIS) is considered for the classifier model. In a first step, QRS complexes are detected. Then, each QRS is delineated by detecting and identifying the peaks of the individual waves, as well as the complex onset and end. Finally, the determination of P and T wave peaks, onsets and ends is performed. We evaluated the algorithm on several manually annotated databases, such as MIT-BIH Arrhythmia and CSE databases, developed for validation purposes. Features based on the ECG waveform shape and heart beat intervals are used as inputs to the classifiers. The performance of the ANFIS model is evaluated in terms of training performance and classification accuracies and the results confirmed that the proposed ANFIS model has potential in classifying the ECG signals. Cross validation is used to measure the classifier performance. A testing classification accuracy of 95.13% is achieved which is a significant improvement.

  7. High efficiency and simple technique for controlling mechanisms by EMG signals

    Science.gov (United States)

    Dugarte, N.; Álvarez, A.; Balacco, J.; Mercado, G.; Gonzalez, A.; Dugarte, E.; Javier, F.; Ceballos, G.; Olivares, A.

    2016-04-01

    This article reports the development of a simple and efficient system that allows control of mechanisms through electromyography (EMG) signals. The novelty about this instrument is focused on individual control of each motion vector mechanism through independent electronic circuits. Each of electronic circuit does positions a motor according to intensity of EMG signal captured. This action defines movement in one mechanical axis considered from an initial point, based on increased muscle tension. The final displacement of mechanism depends on individual’s ability to handle the levels of muscle tension at different body parts. This is the design of a robotic arm where each degree of freedom is handled with a specific microcontroller that responds to signals taken from a defined muscle. The biophysical interaction between the person and the final positioning of the robotic arm is used as feedback. Preliminary tests showed that the control operates with minimal positioning error margins. The constant use of system with the same operator showed that the person adapts and progressively improves at control technique.

  8. Comparison of the optoacoustic signal generation efficiency of different nanoparticular contrast agents.

    Science.gov (United States)

    Bost, Wolfgang; Lemor, Robert; Fournelle, Marc

    2012-11-20

    Optoacoustic imaging represents a new modality that allows noninvasive in vivo molecular imaging with optical contrast and acoustical resolution. Whereas structural or functional imaging applications such as imaging of vasculature do not require contrast enhancing agents, nanoprobes with defined biochemical binding behavior are needed for molecular imaging tasks. Since the contrast of this modality is based on the local optical absorption coefficient, all particle or molecule types that show significant absorption cross sections in the spectral range of the laser wavelength used for signal generation are suitable contrast agents. Currently, several particle types such as gold nanospheres, nanoshells, nanorods, or polymer particles are used as optoacoustic contrast agents. These particles have specific advantages with respect to their absorption properties, or in terms of biologically relevant features (biodegradability, binding to molecular markers). In the present study, a comparative analysis of the signal generation efficiency of gold nanorods, polymeric particles, and magnetite particles using a 1064 nm Nd:YAG laser for signal generation is described.

  9. Co-emergence of multi-scale cortical activities of irregular firing, oscillations and avalanches achieves cost-efficient information capacity

    Science.gov (United States)

    Zhou, Hai-Jun; Zhou, Changsong

    2017-01-01

    The brain is highly energy consuming, therefore is under strong selective pressure to achieve cost-efficiency in both cortical connectivities and activities. However, cost-efficiency as a design principle for cortical activities has been rarely studied. Especially it is not clear how cost-efficiency is related to ubiquitously observed multi-scale properties: irregular firing, oscillations and neuronal avalanches. Here we demonstrate that these prominent properties can be simultaneously observed in a generic, biologically plausible neural circuit model that captures excitation-inhibition balance and realistic dynamics of synaptic conductance. Their co-emergence achieves minimal energy cost as well as maximal energy efficiency on information capacity, when neuronal firing are coordinated and shaped by moderate synchrony to reduce otherwise redundant spikes, and the dynamical clusterings are maintained in the form of neuronal avalanches. Such cost-efficient neural dynamics can be employed as a foundation for further efficient information processing under energy constraint. PMID:28192429

  10. Efficient Consistency Achievement of Federated Identity and Access Management Based on a Novel Self-Adaptable Approach

    Science.gov (United States)

    Cha, Shi-Cho; Chang, Hsiang-Meng

    Federated identity and access management (FIAM) systems enable a user to access services provided by various organizations seamlessly. In FIAM systems, service providers normally stipulate that their users show assertions issued by allied parties to use their services as well as determine user privileges based on attributes in the assertions. However, the integrity of the attributes is important under certain circumstances. In such a circumstance, all released assertions should reflect modifications made to user attributes. Despite the ability to adopt conventional certification revocation technologies, including CRL or OCSP, to revoke an assertion and request the corresponding user to obtain a new assertion, re-issuing an entirely new assertion if only one attribute, such as user location or other environmental information, is changed would be inefficient. Therefore, this work presents a self-adaptive framework to achieve consistency in federated identity and access management systems (SAFIAM). In SAFIAM, an identity provider (IdP), which authenticates users and provides user attributes, should monitor access probabilities according to user attributes. The IdP can then adopt the most efficient means of ensuring data integrity of attributes based on related access probabilities. While Internet-based services emerge daily that have various access probabilities with respect to their user attributes, the proposed self-adaptive framework significantly contributes to efforts to streamline the use of FIAM systems.

  11. Field Programmable DSP Arrays - A Novel Reconfigurable Architecture for Efficient Reliazation of Digital Signal Processing Functions

    Directory of Open Access Journals (Sweden)

    Amitabha Sinha

    2013-04-01

    Full Text Available Digital Signal Processing functions are widely used in real time high speed applications. Those functions are generally implemented either on ASICs with inflexibility, or on FPGAs with bottlenecks of relatively smaller utilization factor or lower speed compared to ASIC. The proposed reconfigurable DSP processor is redolent to FPGA, but with basic fixed Common Modules (CMs (like adders, subtractors, multipliers, scaling units, shifters instead of CLBs. This pape r introduces the development of a reconfigurable DSP processor that integrates different filter and transform functions. The switching between DSP functions is occurred by reconfiguring the interconnection between CMs. Validation of the proposed reconfigurable architecture has been achieved on Virtex5 FPGA. The architecture provides sufficient amount of flexibility, parallelism and scalability.

  12. Can silicon substituted metal-free organic dyes achieve better efficiency compared to silicon free organic dyes? A computational study.

    Science.gov (United States)

    Biswas, Abul Kalam; Das, Amitava; Ganguly, Bishwajit

    2015-12-14

    The power conversion efficiency of metal-free organic dyes in dye-sensitized solar cells (DSSCs) is now comparable to ruthenium-based polypyridyl and zinc-based porphyrin dyes. We have computationally investigated the structural, electronic and optical properties of a series of metal free organic dyes and their corresponding silicon substituted dyes. The DFT and TD-DFT calculations revealed that silicon substituted organic dyes have higher efficiency than the corresponding silicon free organic dyes. The computational results showed that the presence of silole units as a spacer group can significantly affect the performance of DSSCs compared to typically using thiophene as a spacer unit. These results corroborate the experimental observations reported in the literature. The time-dependent density functional theory (TDDFT) calculations performed at the CPCM–CAM-B3LYP/6-31+G* level of theory showed better agreement with the experimental absorption spectra of some reported metal free organic dyes having silole in the spacer group compared to other functionals and are employed in this study. Indoline donor based dye 5 showed a much shorter absorption spectrum (absorption peak at 425 nm) and smaller electron injection driving force (ΔGinjection = -1.77 eV) than the corresponding dye 8 containing silicon substituted indoline as a donor and a silole group as a spacer unit. λmax = 502 nm and ΔGinjection = -1.82 eV calculated for dye 8 are much larger than the corresponding silicon free dye 5. The silicon based dye 8 helps in achieving a much lower ΔGregeneration value than 5, which can facilitate the faster electron injection rate from the dye to the semiconductor TiO2. Dye 8 should also have a higher Voc value compared to other dyes (5-7) due to favourable interaction with the electrolyte (I(-)/I3(-)). The higher planarity and better conjugation in dye 8 facilitate the transfer of electrons from the dye molecules to the semiconductor TiO2. The calculations performed

  13. Arx: a toolset for the efficient simulation and direct synthesis of high-performance signal processing algorithms

    NARCIS (Netherlands)

    Hofstra, K.L.; Gerez, S.H.

    2007-01-01

    This paper addresses the efficient implementation of highperformance signal-processing algorithms. In early stages of such designs many computation-intensive simulations may be necessary. This calls for hardware description formalisms targeted for efficient simulation (such as the programming langua

  14. Improving the efficiency of the detection of gravitational wave signals from inspiraling compact binaries: Chebyshev interpolation

    CERN Document Server

    Mitra, S; Finn, L S

    2005-01-01

    Inspiraling compact binaries are promising sources of gravitational waves for ground and space-based laser interferometric detectors. The time-dependent signature of these sources in the detectors is a well-characterized function of a relatively small number of parameters; thus, the favored analysis technique makes use of matched filtering and maximum likelihood methods. Current analysis methodology samples the matched filter output at parameter values chosen so that the correlation between successive samples is 97% for which the filtered output is closely correlated. Here we describe a straightforward and practical way of using interpolation to take advantage of the correlation between the matched filter output associated with nearby points in the parameter space to significantly reduce the number of matched filter evaluations without sacrificing the efficiency with which real signals are recognized. Because the computational cost of the analysis is driven almost exclusively by the matched filter evaluations...

  15. Signal-signal beat interference cancellation in spectrally-efficient WDM direct-detection Nyquist-pulse-shaped 16-QAM subcarrier modulation.

    Science.gov (United States)

    Li, Zhe; Erkılınç, M Sezer; Pachnicke, Stephan; Griesser, Helmut; Bouziane, Rachid; Thomsen, Benn C; Bayvel, Polina; Killey, Robert I

    2015-09-01

    An experimental demonstration of direct-detection single-sideband Nyquist-pulse-shaped 16-QAM subcarrier modulated (Nyquist-SCM) transmission implementing a receiver-based signal-signal beat interference (SSBI) cancellation technique is described. The performance improvement with SSBI mitigation, which compensates for the nonlinear distortion caused by square-law detection, was quantified by simulations and experiments for a 7 × 25 Gb/s WDM Nyquist-SCM signal with a net optical information spectral density (ISD) of 2.0 (b/s)/Hz. A reduction of 3.6 dB in the back-to-back required OSNR at the HD-FEC threshold was achieved. The resulting reductions in BER in single channel and WDM transmission over distances of up to 800 km of uncompensated standard single-mode fiber (SSMF) achieved are presented.

  16. Efficient Implementation of Elliptic Curve Cryptography Using Low-power Digital Signal Processor

    CERN Document Server

    Malik, Muhammad Yasir

    2011-01-01

    RSA(Rivest, Shamir and Adleman)is being used as a public key exchange and key agreement tool for many years. Due to large numbers involved in RSA, there is need for more efficient methods in implementation for public key cryptosystems. Elliptic Curve Cryptography(ECC) is based on elliptic curves defined over a finite field. Elliptic curve cryptosystems(ECC) were discovered by Victor Miller and Neal Koblitz in 1985.This paper comprises of five sections. Section I is introduction to ECC and its components. Section II describes advantages of ECC schemes and its comparison with RSA. Section III is about some of the applications of ECC. Section IV gives some embedded implementations of ECC. Section V contains ECC implementation on fixed point Digital Signal Processor(TMS320VC5416). ECC was implemented using general purpose microcontrollers and Field Programmable Gate Arrays (FPGA) before this work. DSP is more powerful than microcontrollers and much economical than FPGA. So this implementation can be efficiently u...

  17. Efficient transmission of subthreshold signals in complex networks of spiking neurons.

    Directory of Open Access Journals (Sweden)

    Joaquin J Torres

    Full Text Available We investigate the efficient transmission and processing of weak, subthreshold signals in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances--that naturally balances the network with excitatory and inhibitory synapses--and considering short-term synaptic plasticity affecting such conductances, we found different dynamic phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron, increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases for well-defined different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite robust, as it occurs in different situations including several types of synaptic plasticity, different type and number of stored patterns and diverse network topologies, namely, diluted networks and complex topologies such as scale-free and small-world networks. We conclude that the robustness of the phenomenon in different realistic scenarios, including spiking neurons, short-term synaptic plasticity and complex networks topologies, make very likely that it could also occur in actual neural systems as recent psycho-physical experiments suggest.

  18. High antipredatory efficiency of insular lizards: a warning signal of excessive specimen collection?

    Directory of Open Access Journals (Sweden)

    Miguel Delibes

    Full Text Available We live-captured lizards on islands in the Gulf of California and the Baja California peninsula mainland, and compared their ability to escape predation. Contrary to expectations, endemic lizard species from uninhabited islands fled from humans earlier and more efficiently than those from peninsular mainland areas. In fact, 58.2% (n=146 of the lizards we tried to capture on the various islands escaped successfully, while this percentage was only 14.4% (n=160 on the peninsular mainland. Separate evidence (e.g., proportion of regenerated tails, low human population at the collection areas, etc. challenges several potential explanations for the higher antipredatory efficiency of insular lizards (e.g., more predation pressure on islands, habituation to humans on the peninsula, etc.. Instead, we suggest that the ability of insular lizards to avoid predators may be related to harvesting by humans, perhaps due to the value of endemic species as rare taxonomic entities. If this hypothesis is correct, predation-related behavioral changes in rare species could provide early warning signals of their over-exploitation, thus encouraging the adoption of conservation measures.

  19. Signal Processing and Its Effect on Scanning Efficiencies for a Field Instrument for Detecting Low-energy Radiation.

    Science.gov (United States)

    Marianno, Craig M

    2015-07-01

    Signal processing within a radiation detector affects detection efficiency. Currently, organizations such as private industry, the U.S. Navy, Army, and Air Force are coupling some detector systems with data collection devices to survey large land areas for radioactive contamination. As detector technology has advanced and analog data collection has turned to digital, signal processing is becoming prevalent in some instruments. Using a NIST traceable (241)Am source, detection efficiency for a field instrument for detecting low-energy radiation (FIDLER) was examined for both a static and scanning mode. Experimental results were compared to Monte Carlo-generated efficiencies. Stationary data compared nicely to the theoretical results. Conversely, scanning detection efficiencies were considerably different from their theoretical counterparts. As speed increased, differences in detection efficiency approached two orders of magnitude. To account for these differences, a quasi time-dependent Monte Carlo simulation was created mimicking the signal processing undertaken by the FIDLER detection system. By including signal processing, experimental results fell within the bounds of the Monte Carlo-generated efficiencies, thus demonstrating the negative effects of such processing on detection efficiencies.

  20. Optical signal processing for enabling high-speed, highly spectrally efficient and high capacity optical systems

    Science.gov (United States)

    Fazal, Muhammad Irfan

    may be possible. Recently, interest has increased in exploring the spatial dimension of light to increase capacity, both in fiber as well as free-space communication channels. The orbital angular momentum (OAM) of light, carried by Laguerre-Gaussian (LG) beams have the interesting property that, in theory, an infinite number of OAMs can be transmitted; which due to its inherent orthogonality will not affect each other. Thus, in theory, one can increase the channel capacity arbitrarily. However, in practice, the device dimensions will reduce the number of OAMs used. In addition to advanced modulation formats, it is expected that optical signal processing may play a role in the future development of more efficient optical transmission systems. The hope is that performing signal processing in the optical domain may reduce optical-to-electronic conversion inefficiencies, eliminate bottlenecks and take advantage of the ultrahigh bandwidth inherent in optics. While 40 to 50 Gbit/s electronic components are the peak of commercial technology and 100 Gbit/s capable RF components are still in their infancy, optical signal processing of these high-speed data signals may provide a potential solution. Furthermore, any optical processing system or sub-system must be capable of handling the wide array of data formats and data rates that networks may employ. The work presented in this Ph.D. dissertation attempts at addressing the issue of optical processing for advanced optical modulation formats, and particularly explores the state of the art in increasing the capacity of an optical link by a combination of wavelength/phase/polarization/OAM dimensions of light. Spatial multiplexing and demultiplexing of both coherently and directly detected signals at the 100 Gbit/s Ethernet standard is addressed. The application of a continuously tunable all-optical delay for all-optical functionality like time-slot interchange at high data-rates is presented. Moreover the interplay of chirp

  1. An Efficient Measure for Nonlinear Distortion Severity due to HPA in Downlink DS-CDMA Signals

    Directory of Open Access Journals (Sweden)

    Helaly TarekK

    2010-01-01

    Full Text Available This paper deals with the nonlinear distortion (NLD effects of high power amplifiers (HPAs on direct sequence-code division multiple access systems. Such a distortion drastically degrades the system performance in terms of bit error rate (BER degradation and spectral regrowth. Much effort has been conducted to minimize NLD. A key requirement to do so is to define a certain measure for the HPA nonlinearity, which when reduced often allows NLD to also be reduced. Several measures were proposed such as peak-to-average power ratio, instantaneous power variance, and cubic metric. In this paper, we show that such measures are not closely related to NLD and their reduction does not always lead to optimum performance. Hence, we introduce an efficient measure, namely, nonlinearity severity (NLS, to characterize NLD effects, as an alternative to the existing measures. The NLS is characterized by having direct link to the system performance as it is formulated based on the signal characteristics contributing to BER performance and spectral regrowth. Additionally, a major advantage of the NLS measure is that it is linked to the IBO level allowing the possibility of improving performance at all IBO levels of interest.

  2. Reliable and Efficient Parallel Processing Algorithms and Architectures for Modern Signal Processing. Ph.D. Thesis

    Science.gov (United States)

    Liu, Kuojuey Ray

    1990-01-01

    Least-squares (LS) estimations and spectral decomposition algorithms constitute the heart of modern signal processing and communication problems. Implementations of recursive LS and spectral decomposition algorithms onto parallel processing architectures such as systolic arrays with efficient fault-tolerant schemes are the major concerns of this dissertation. There are four major results in this dissertation. First, we propose the systolic block Householder transformation with application to the recursive least-squares minimization. It is successfully implemented on a systolic array with a two-level pipelined implementation at the vector level as well as at the word level. Second, a real-time algorithm-based concurrent error detection scheme based on the residual method is proposed for the QRD RLS systolic array. The fault diagnosis, order degraded reconfiguration, and performance analysis are also considered. Third, the dynamic range, stability, error detection capability under finite-precision implementation, order degraded performance, and residual estimation under faulty situations for the QRD RLS systolic array are studied in details. Finally, we propose the use of multi-phase systolic algorithms for spectral decomposition based on the QR algorithm. Two systolic architectures, one based on triangular array and another based on rectangular array, are presented for the multiphase operations with fault-tolerant considerations. Eigenvectors and singular vectors can be easily obtained by using the multi-pase operations. Performance issues are also considered.

  3. Focal overlap gating in velocity map imaging to achieve high signal-to-noise ratio in photo-ion pump-probe experiments

    CERN Document Server

    Shivaram, Niranjan; Cryan, James P; Wright, Travis W; Wingard, Taylor; Belkacem, Ali

    2016-01-01

    We demonstrate a new technique in velocity map imaging (VMI) that allows spatial gating of the laser focal overlap region in time resolved pump-probe experiments. This significantly enhances signal-to-noise ratio by eliminating background signal arising outside the region of spatial overlap of pump and probe beams. This enhancement is achieved by tilting the laser beams with respect to the surface of the VMI electrodes which creates a gradient in flight time for particles born at different points along the beam. By suitably pulsing our microchannel plate detector, we can select particles born only where the laser beams overlap. This spatial gating in velocity map imaging can benefit nearly all photoion pump-probe VMI experiments especially when extreme-ultraviolet (XUV) light or X-rays are involved which produce large background signals on their own.

  4. Measuring Transit Signal Recovery in the Kepler Pipeline II: Detection Efficiency as Calculated in One Year of Data

    CERN Document Server

    Christiansen, Jessie L; Burke, Christopher J; Seader, Shawn; Jenkins, Jon M; Twicken, Joseph D; Smith, Jeffrey C; Batalha, Natalie M; Haas, Michael R; Thompson, Susan E; Campbell, Jennifer R; Sabale, Anima; Uddin, Akm Kamal

    2015-01-01

    The Kepler planet sample can only be used to reconstruct the underlying planet occurrence rate if the detection efficiency of the Kepler pipeline is known, here we present the results of a second experiment aimed at characterising this detection efficiency. We inject simulated transiting planet signals into the pixel data of ~10,000 targets, spanning one year of observations, and process the pixels as normal. We compare the set of detections made by the pipeline with the expectation from the set of simulated planets, and construct a sensitivity curve of signal recovery as a function of the signal-to-noise of the simulated transit signal train. The sensitivity curve does not meet the hypothetical maximum detection efficiency, however it is not as pessimistic as some of the published estimates of the detection efficiency. For the FGK stars in our sample, the sensitivity curve is well fit by a gamma function with the coefficients a = 4.35 and b = 1.05. We also find that the pipeline algorithms recover the depths...

  5. Capacity-Approaching Modulation Formats for Optical Transmission Systems: Signal shaping and advanced de/muxing for efficient resource exploitation

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel

    Aiming for efficient fiber-optic data transport, this thesis addresses three scenario-specific modulation and/or multiplexing techniques which, leveraging digital signal processing, can further exploit the available resources.The considered environments are: (i) (ultra) long-haul networks, where we...

  6. The leukemia-associated Rho guanine nucleotide exchange factor LARG is required for efficient replication stress signaling.

    Science.gov (United States)

    Beveridge, Ryan D; Staples, Christopher J; Patil, Abhijit A; Myers, Katie N; Maslen, Sarah; Skehel, J Mark; Boulton, Simon J; Collis, Spencer J

    2014-01-01

    We previously identified and characterized TELO2 as a human protein that facilitates efficient DNA damage response (DDR) signaling. A subsequent yeast 2-hybrid screen identified LARG; Leukemia-Associated Rho Guanine Nucleotide Exchange Factor (also known as Arhgef12), as a potential novel TELO2 interactor. LARG was previously shown to interact with Pericentrin (PCNT), which, like TELO2, is required for efficient replication stress signaling. Here we confirm interactions between LARG, TELO2 and PCNT and show that a sub-set of LARG co-localizes with PCNT at the centrosome. LARG-deficient cells exhibit replication stress signaling defects as evidenced by; supernumerary centrosomes, reduced replication stress-induced γH2AX and RPA nuclear foci formation, and reduced activation of the replication stress signaling effector kinase Chk1 in response to hydroxyurea. As such, LARG-deficient cells are sensitive to replication stress-inducing agents such as hydroxyurea and mitomycin C. Conversely we also show that depletion of TELO2 and the replication stress signaling kinase ATR leads to RhoA signaling defects. These data therefore reveal a level of crosstalk between the RhoA and DDR signaling pathways. Given that mutations in both ATR and PCNT can give rise to the related primordial dwarfism disorders of Seckel Syndrome and Microcephalic osteodysplastic primordial dwarfism type II (MOPDII) respectively, which both exhibit defects in ATR-dependent checkpoint signaling, these data also raise the possibility that mutations in LARG or disruption to RhoA signaling may be contributory factors to the etiology of a sub-set of primordial dwarfism disorders.

  7. Efficient differentiation of embryonic stem cells into mesodermal precursors by BMP, retinoic acid and Notch signalling.

    Directory of Open Access Journals (Sweden)

    Josema Torres

    Full Text Available The ability to direct differentiation of mouse embryonic stem (ES cells into specific lineages not only provides new insights into the pathways that regulate lineage selection but also has translational applications, for example in drug discovery. We set out to develop a method of differentiating ES cells into mesodermal cells at high efficiency without first having to induce embryoid body formation. ES cells were plated on a feeder layer of PA6 cells, which have membrane-associated stromal-derived inducing activity (SDIA, the molecular basis of which is currently unknown. Stimulation of ES/PA6 co-cultures with Bone Morphogenetic Protein 4 (BMP4 both favoured self-renewal of ES cells and induced differentiation into a Desmin and Nestin double positive cell population. Combined stimulation with BMP4 and all-trans Retinoic Acid (RA inhibited self-renewal and resulted in 90% of cells expressing Desmin and Nestin. Quantitative reverse transcription-polymerase chain reaction (qPCR analysis confirmed that the cells were of mesodermal origin and expressed markers of mesenchymal and smooth muscle cells. BMP4 activation of a MAD-homolog (Smad-dependent reporter in undifferentiated ES cells was attenuated by co-stimulation with RA and co-culture with PA6 cells. The Notch ligand Jag1 was expressed in PA6 cells and inhibition of Notch signalling blocked the differentiation inducing activity of PA6 cells. Our data suggest that mesodermal differentiation is regulated by the level of Smad activity as a result of inputs from BMP4, RA and the Notch pathway.

  8. Input/output Buffer based Vedic Multiplier Design for Thermal Aware Energy Efficient Digital Signal Processing on 28nm FPGA

    DEFF Research Database (Denmark)

    Goswami, Kavita; Pandey, Bishwajeet; Hussain, Dil muhammed Akbar

    2016-01-01

    Multiplier is used for multiplication of a signal and a constant in digital signal processing (DSP). 28nm technology based Vedic multiplier is implemented with use of VHDL HDL, Xilinx ISE, Kintex-7 FPGA and XPower Analyzer. Vedic multiplier gain speed improvements by parallelizing the generation...... Programmable Gate Array (FPGA) in order to reduce the development cost. The development cost for Application Specific Integrated Circuits (ASICs) are high in compare to FPGA. Selection of the most energy efficient IO standards in place of signal gating is the main design methodology for design of energy...... efficient Vedic multiplier.There is 68.51%, 69.86%, 74.65%, and 78.39% contraction in total power of Vedic multiplier on 28nm Kintex-7 FPGA, when we use HSTL_II in place of HSTL_II_DCI_18 at 56.7oC, 53.5oC, 40oC and 21oC respectively....

  9. Inflammation-Induced CCR7 Oligomers Form Scaffolds to Integrate Distinct Signaling Pathways for Efficient Cell Migration.

    Science.gov (United States)

    Hauser, Mark A; Schaeuble, Karin; Kindinger, Ilona; Impellizzieri, Daniela; Krueger, Wolfgang A; Hauck, Christof R; Boyman, Onur; Legler, Daniel F

    2016-01-19

    Host defense depends on orchestrated cell migration guided by chemokines that elicit selective but biased signaling pathways to control chemotaxis. Here, we showed that different inflammatory stimuli provoked oligomerization of the chemokine receptor CCR7, enabling human dendritic cells and T cell subpopulations to process guidance cues not only through classical G protein-dependent signaling but also by integrating an oligomer-dependent Src kinase signaling pathway. Efficient CCR7-driven migration depends on a hydrophobic oligomerization interface near the conserved NPXXY motif of G protein-coupled receptors as shown by mutagenesis screen and a CCR7-SNP demonstrating super-oligomer characteristics leading to enhanced Src activity and superior chemotaxis. Furthermore, Src phosphorylates oligomeric CCR7, thereby creating a docking site for SH2-domain-bearing signaling molecules. Finally, we identified CCL21-biased signaling that involved the phosphatase SHP2 to control efficient cell migration. Collectively, our data showed that CCR7 oligomers serve as molecular hubs regulating distinct signaling pathways.

  10. Low-cost and no-cost practice to achieve energy efficiency of government office buildings: A case study in federal territory of Malaysia

    Science.gov (United States)

    Tahir, Mohamad Zamhari; Nawi, Mohd Nasrun Mohd; Ibrahim, Amlus

    2016-08-01

    This paper presents the findings of a case study to achieve energy-efficient performance of conventional office buildings in Malaysia. Two multi-storey office buildings in Federal Territory of Malaysia have been selected. The aim is to study building energy saving potential then to highlight the appropriate measures that can be implemented. Data was collected using benchmarking method by comparing the measured consumption to other similar office buildings and a series of preliminary audit which involves interviews, a brief review of utility and operating data as well as a walkthrough in the buildings. Additionally, in order to get a better understanding of major energy consumption in the selected buildings, general audit have been conducted to collect more detailed information about building operation. In the end, this study emphasized low-cost and no-cost practice to achieve energy efficiency with significant results in some cases.

  11. Computationally Efficient Calculations of Target Performance of the Normalized Matched Filter Detector for Hydrocoustic Signals

    CERN Document Server

    Diamant, Roee

    2016-01-01

    Detection of hydroacoustic transmissions is a key enabling technology in applications such as depth measurements, detection of objects, and undersea mapping. To cope with the long channel delay spread and the low signal-to-noise ratio, hydroacoustic signals are constructed with a large time-bandwidth product, $N$. A promising detector for hydroacoustic signals is the normalized matched filter (NMF). For the NMF, the detection threshold depends only on $N$, thereby obviating the need to estimate the characteristics of the sea ambient noise which are time-varying and hard to estimate. While previous works analyzed the characteristics of the normalized matched filter (NMF), for hydroacoustic signals with large $N$ values the expressions available are computationally complicated to evaluate. Specifically for hydroacoustic signals of large $N$ values, this paper presents approximations for the probability distribution of the NMF. These approximations are found extremely accurate in numerical simulations. We also o...

  12. Absorber and emitter for solar thermo-photovoltaic systems to achieve efficiency exceeding the Shockley-Queisser limit.

    Science.gov (United States)

    Rephaeli, Eden; Fan, Shanhui

    2009-08-17

    We present theoretical considerations as well as detailed numerical design of absorber and emitter for Solar Thermophotovoltaics (STPV) applications. The absorber, consisting of an array of tungsten pyramids, was designed to provide near-unity absorptivity over all solar wavelengths for a wide angular range, enabling it to absorb light effectively from solar sources regardless of concentration. The emitter, a tungsten slab with Si/SiO(2) multilayer stack, provides a sharp emissivity peak at the solar cell band-gap while suppressing emission at lower frequencies. We show that, under a suitable light concentration condition, and with a reasonable area ratio between the emitter and absorber, a STPV system employing such absorber-emitter pair and a single-junction solar cell can attain efficiency that exceeds the Shockley-Queisser limit.

  13. CHARACTERISTICS OF MANAGEMENT AND LEADERSHIP IN ORDER TO EFFICIENTLY ACHIEVE THE ORGANIZATIONAL CHANGES PRODUCED BY THE ECONOMIC CRISIS

    Directory of Open Access Journals (Sweden)

    Iuliana Talmaciu

    2015-05-01

    Full Text Available Change has become the watchword of the present times. The dynamism of economic, social and political life is becoming more pronounced and it determines numerous organizational changes. In times of crisis and during the following periods, companies face major challenges, changes becoming even harder to anticipate and plan. The economic difficulties encountered by the business environment can be a decisive test for the leaders of companies. The main purpose of this article is to analyze the leadership characteristics which are necessary to efficiently manage and implement organizational changes during crisis. The research method used in this paper was based on the content analysis of works by both Romanian and foreign authors and on some studies conducted by different specialized companies. This paper is structured as follows: introduction, aspects regarding managers' role in change management, characteristics needed by the leaders involved in the change process, conclusions and biography.

  14. Achieving Extreme Utilization of Excitons by an Efficient Sandwich-Type Emissive Layer Architecture for Reduced Efficiency Roll-Off and Improved Operational Stability in Organic Light-Emitting Diodes.

    Science.gov (United States)

    Wu, Zhongbin; Sun, Ning; Zhu, Liping; Sun, Hengda; Wang, Jiaxiu; Yang, Dezhi; Qiao, Xianfeng; Chen, Jiangshan; Alshehri, Saad M; Ahamad, Tansir; Ma, Dongge

    2016-02-10

    It has been demonstrated that the efficiency roll-off is generally caused by the accumulation of excitons or charge carriers, which is intimately related to the emissive layer (EML) architecture in organic light-emitting diodes (OLEDs). In this article, an efficient sandwich-type EML structure with a mixed-host EML sandwiched between two single-host EMLs was designed to eliminate this accumulation, thus simultaneously achieving high efficiency, low efficiency roll-off and good operational stability in the resulting OLEDs. The devices show excellent electroluminescence performances, realizing a maximum external quantum efficiency (EQE) of 24.6% with a maximum power efficiency of 105.6 lm W(-1) and a maximum current efficiency of 93.5 cd A(-1). At the high brightness of 5,000 cd m(-2), they still remain as high as 23.3%, 71.1 lm W(-1), and 88.3 cd A(-1), respectively. And, the device lifetime is up to 2000 h at initial luminance of 1000 cd m(-2), which is significantly higher than that of compared devices with conventional EML structures. The improvement mechanism is systematically studied by the dependence of the exciton distribution in EML and the exciton quenching processes. It can be seen that the utilization of the efficient sandwich-type EML broadens the recombination zone width, thus greatly reducing the exciton quenching and increasing the probability of the exciton recombination. It is believed that the design concept provides a new avenue for us to achieve high-performance OLEDs.

  15. High-efficiency transfection and survival rates of embryonic and adult mouse neural stem cells achieved by electroporation.

    Science.gov (United States)

    Bertram, Bettina; Wiese, Stefan; von Holst, Alexander

    2012-08-15

    Cells of the central nervous system are notoriously difficult to transfect. This is not only true for neurons and glial cells but also for dividing neural stem and progenitor cells (NSCs). About ten years ago a major advance was provided by introduction of the nucleofection technology that allowed for transfection of approximately half of the exposed NSCs. However, limitations were encountered with the need for large numbers of NSCs for a single transfection and compromised survival rates with typically only one-third of the cells surviving the pulse conditions. Here, we report the establishment of a pulse protocol that targets NSCs with high efficiency and twofold higher NSC survival rates using the 4D Nucleofector device. We demonstrate that the established protocol not only provides a clear and significant improvement over existing protocols with transfection rates above 80% and two-thirds of the NSCs surviving for at least 48h, but also their unaltered differentiation along neuronal and glial lineages. This improved protocol for the transfection of sensitive mouse central nervous system derived cells will provide an important step forward for studies of gene function by overexpression or knock-down of genes in cultured NSCs.

  16. Enhanced Conversion Efficiencies in Dye-Sensitized Solar Cells Achieved through Self-Assembled Platinum(II) Metallacages

    Science.gov (United States)

    He, Zuoli; Hou, Zhiqiang; Xing, Yonglei; Liu, Xiaobin; Yin, Xingtian; Que, Meidan; Shao, Jinyou; Que, Wenxiu; Stang, Peter J.

    2016-07-01

    Two-component self-assembly supramolecular coordination complexes with particular photo-physical property, wherein unique donors are combined with a single metal acceptor, can be utilized for many applications including in photo-devices. In this communication, we described the synthesis and characterization of two-component self-assembly supramolecular coordination complexes (SCCs) bearing triazine and porphyrin faces with promising light-harvesting properties. These complexes were obtained from the self-assembly of a 90° Pt(II) acceptor with 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPyT) or 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (TPyP). The greatly improved conversion efficiencies of the dye-sensitized TiO2 solar cells were 6.79 and 6.08 respectively, while these SCCs were introduced into the TiO2 nanoparticle film photoanodes. In addition, the open circuit voltage (Voc) of dye-sensitized solar cells was also increased to 0.769 and 0.768 V, which could be ascribed to the inhibited interfacial charge recombination due to the addition of SCCs.

  17. Heavy metal accumulation and signal transduction in herbaceous and woody plants: Paving the way for enhancing phytoremediation efficiency.

    Science.gov (United States)

    Luo, Zhi-Bin; He, Jiali; Polle, Andrea; Rennenberg, Heinz

    2016-11-01

    Heavy metal (HM)-accumulating herbaceous and woody plants are employed for phytoremediation. To develop improved strategies for enhancing phytoremediation efficiency, knowledge of the microstructural, physiological and molecular responses underlying HM-accumulation is required. Here we review the progress in understanding the structural, physiological and molecular mechanisms underlying HM uptake, transport, sequestration and detoxification, as well as the regulation of these processes by signal transduction in response to HM exposure. The significance of genetic engineering for enhancing phytoremediation efficiency is also discussed. In herbaceous plants, HMs are taken up by roots and transported into the root cells via transmembrane carriers for nutritional ions. The HMs absorbed by root cells can be further translocated to the xylem vessels and unloaded into the xylem sap, thereby reaching the aerial parts of plants. HMs can be sequestered in the cell walls, vacuoles and the Golgi apparatuses. Plant roots initially perceive HM stress and trigger the signal transduction, thereby mediating changes at the molecular, physiological, and microstructural level. Signaling molecules such as phytohormones, reactive oxygen species (ROS) and nitric oxide (NO), modulate plant responses to HMs via differentially expressed genes, activation of the antioxidative system and coordinated cross talk among different signaling molecules. A number of genes participated in HM uptake, transport, sequestration and detoxification have been functionally characterized and transformed to target plants for enhancing phytoremediation efficiency. Fast growing woody plants hold an advantage over herbaceous plants for phytoremediation in terms of accumulation of high HM-amounts in their large biomass. Presumably, woody plants accumulate HMs using similar mechanisms as herbaceous counterparts, but the processes of HM accumulation and signal transduction can be more complex in woody plants.

  18. Efficiency

    NARCIS (Netherlands)

    I.P. van Staveren (Irene)

    2009-01-01

    textabstractThe dominant economic theory, neoclassical economics, employs a single economic evaluative criterion: efficiency. Moreover, it assigns this criterion a very specific meaning. Other – heterodox – schools of thought in economics tend to use more open concepts of efficiency, related to comm

  19. Novel Blue Organic Dye for Dye-Sensitized Solar Cells Achieving High Efficiency in Cobalt-Based Electrolytes and by Co-Sensitization.

    Science.gov (United States)

    Hao, Yan; Saygili, Yasemin; Cong, Jiayan; Eriksson, Anna; Yang, Wenxing; Zhang, Jinbao; Polanski, Enrico; Nonomura, Kazuteru; Zakeeruddin, Shaik Mohammed; Grätzel, Michael; Hagfeldt, Anders; Boschloo, Gerrit

    2016-12-07

    Blue and green dyes as well as NIR-absorbing dyes have attracted great interest because of their excellent ability of absorbing the incident photons in the red and near-infrared range region. A novel blue D-π-A dye (Dyenamo Blue), based on the diketopyrrolopyrrole (DPP)-core, has been designed and synthesized. Assembled with the cobalt bipyridine-based electrolytes, the device with Dyenamo Blue achieved a satisfying efficiency of 7.3% under one sun (AM1.5 G). The co-sensitization strategy was further applied on this blue organic dye together with a red D-π-A dye (D35). The successful co-sensitization outperformed a panchromatic light absorption and improved the photocurrent density; this in addition to the open-circuit potential result in an efficiency of 8.7%. The extended absorption of the sensitization and the slower recombination reaction between the blue dye and TiO2 surface inhibited by the additional red sensitizer could be the two main reasons for the higher performance. In conclusion, from the results, the highly efficient cobalt-based DSSCs could be achieved with the co-sensitization between red and blue D-π-A organic dyes with a proper design, which showed us the possibility of applying this strategy for future high-performance solar cells.

  20. Identification of Domains for Efficient Notch Signaling Activity in Immobilized Notch Ligand Proteins.

    Science.gov (United States)

    Liu, Ledi; Wada, Hiroe; Matsubara, Natsuki; Hozumi, Katsuto; Itoh, Motoyuki

    2017-04-01

    Notch is a critical signaling pathway that controls cell fate and tissue homeostasis, but the functional characterization of Notch ligand domains that activate Notch receptors remains incomplete. Here, we established a method for immobilizing Notch ligand proteins onto beads to measure time-dependent Notch activity after the addition of Notch ligand-coated beads. A comparison between activities by the Notch ligand found on the cell surface to that of the ligand immobilized on beads showed that immobilized Notch ligand protein produces comparable signal activity during the first 10 h. Follow-up truncation studies showed that the N-terminal epidermal growth factor (EGF) repeat three region of delta like canonical Notch ligand 4 (DLL4) or jagged 1 (JAG1) is the minimum region for activating Notch signaling, and the DLL4 EGF repeat three domain may have a role in activation through a mechanism other than by increasing binding affinity. In addition, we found that reconstruction of the DLL4 delta and OSM-11 (DOS) motif (N257P) resulted in an increase in both binding affinity and signaling activity, which suggests that the role of the DOS motif is conserved among Notch ligands. Furthermore, active DLL4 protein on beads promoted T cell differentiation or inhibited B cell differentiation in vitro, whereas JAG1 proteins on beads did not have any effect. Taken together, our findings provide unambiguous evidence for the role of different Notch ligands and their domains in Notch signal activation, and may be potential tools for controlling Notch signaling activation. J. Cell. Biochem. 118: 785-796, 2017. © 2016 Wiley Periodicals, Inc.

  1. Efficient method for measuring the parameters encoded in a gravitational-wave signal

    CERN Document Server

    Haster, Carl-Johan; Farr, Will M

    2015-01-01

    Once upon a time, predictions for the accuracy of inference on gravitational-wave signals relied on computationally inexpensive but often inaccurate techniques. Recently, the approach has shifted to actual inference on noisy signals with complex stochastic Bayesian methods, at the expense of significant computational cost. Here, we argue that it is often possible to have the best of both worlds: a Bayesian approach that incorporates prior information and correctly marginalizes over uninteresting parameters, providing accurate posterior probability distribution functions, but carried out on a simple grid at a low computational cost, comparable to the inexpensive predictive techniques.

  2. Signal recognition efficiencies of artificial neural-network pulse-shape discrimination in HPGe 0νββ-decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, A.; Cossavella, F.; Majorovits, B.; Palioselitis, D.; Volynets, O. [Max-Planck-Institut fuer Physik, Munich (Germany)

    2015-07-15

    A pulse-shape discrimination method based on artificial neural networks was applied to pulses simulated for different background, signal and signal-like interactions inside a germanium detector. The simulated pulses were used to investigate variations of efficiencies as a function of used training set. It is verified that neural networks are well-suited to identify background pulses in true-coaxial high-purity germanium detectors. The systematic uncertainty on the signal recognition efficiency derived using signal-like evaluation samples from calibration measurements is estimated to be 5 %. This uncertainty is due to differences between signal and calibration samples. (orig.)

  3. Transmitting RS232/RS485 signal via fiber achieved by CPL%光纤传输 RS232/RS485信号的 CPLD 实现

    Institute of Scientific and Technical Information of China (English)

    陈振; 王景存; 王祥; 赵煜

    2014-01-01

    In the article, a convert-system is designed base on CPLD, which modulates the RS232/RS485 sig-nal in QDPSK, and converts it to optical signal, then transmits the signal via optical fiber, so that the system achieves the long-distance communication of RS232/RS485. It can be seen from the result of the experimental test and field operating that the system has a good performance, and can be a solution of the long-distance communication of RS232/RS485.%基于CPLD设计一个转换系统,对RS232/RS485信号进行QDPSK调制,并转换成光信号,利用光纤进行传输,实现了RS232/RS485的远距离通信。通过实验测试和现场运行结果来看,本系统性能良好,可以作为一种RS232/RS485远距离通信的解决方案。

  4. Inflammatory stress increases hepatic CD36 translational efficiency via activation of the mTOR signalling pathway.

    Directory of Open Access Journals (Sweden)

    Chuan Wang

    Full Text Available Inflammatory stress is an independent risk factor for the development of non-alcoholic fatty liver disease (NAFLD. Although CD36 is known to facilitate long-chain fatty acid uptake and contributes to NAFLD progression, the mechanisms that link inflammatory stress to hepatic CD36 expression and steatosis remain unclear. As the mammalian target of rapamycin (mTOR signalling pathway is involved in CD36 translational activation, this study was undertaken to investigate whether inflammatory stress enhances hepatic CD36 expression via mTOR signalling pathway and the underlying mechanisms. To induce inflammatory stress, we used tumour necrosis factor alpha (TNF-α and interleukin-6 (IL-6 stimulation of the human hepatoblastoma HepG2 cells in vitro and casein injection in C57BL/6J mice in vivo. The data showed that inflammatory stress increased hepatic CD36 protein levels but had no effect on mRNA expression. A protein degradation assay revealed that CD36 protein stability was not different between HepG2 cells treated with or without TNF-α or IL-6. A polysomal analysis indicated that CD36 translational efficiency was significantly increased by inflammatory stress. Additionally, inflammatory stress enhanced the phosphorylation of mTOR and its downstream translational regulators including p70S6K, 4E-BP1 and eIF4E. Rapamycin, an mTOR-specific inhibitor, reduced the phosphorylation of mTOR signalling pathway and decreased the CD36 translational efficiency and protein level even under inflammatory stress resulting in the alleviation of inflammatory stress-induced hepatic lipid accumulation. This study demonstrates that the activation of the mTOR signalling pathway increases hepatic CD36 translational efficiency, resulting in increased CD36 protein expression under inflammatory stress.

  5. Efficient, high-brightness wavelength-beam-combined commercial off-the-shelf diode stacks achieved by use of a wavelength-chirped volume Bragg grating.

    Science.gov (United States)

    Chann, B; Goyal, A K; Fan, T Y; Sanchez-Rubio, A; Volodin, B L; Ban, V S

    2006-05-01

    We report a method of scaling the spatial brightness from commercial off-the-shelf diode laser stacks through wavelength beam combining, by use of a linearly wavelength-chirped volume Bragg grating (VBG). Using a three-bar commercial stack of broad-area lasers and a VBG, we demonstrate 89.5 W cw of beam-combined output with a beam-combining efficiency of 75%. The output beam has a propagation factor M2 approximately 26 on the slow axis and M2 approximately 21 on the fast axis. This corresponds to a brightness of approximately 20 MW/cm2 sr. To our knowledge, this is the highest brightness broad-area diode laser system. We achieve 81% coupling efficiency into a 100 microm, 0.22 N.A. fiber.

  6. Ultrathin Al2O3 interface achieving an 11.46% efficiency in planar n-Si/PEDOT:PSS hybrid solar cells

    Science.gov (United States)

    Nam, Yoon-Ho; Song, Jae-Won; Park, Min-Joon; Sami, Abdul; Lee, Jung-Ho

    2017-04-01

    Hybrid organic–inorganic photovoltaic devices consisting of poly(3,4-etyhlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and n-type silicon have recently been investigated for their cost-efficiency and ease of fabrication. We demonstrate that the insertion of an ultrathin Al2O3 layer between n-Si and PEDOT:PSS significantly improves photovoltaic performance in comparison to the conventional interfacial oxide employing SiO2. A power-conversion efficiency of 11.46% was recorded at the optimal Al2O3 thickness of 2.3 nm. This result was achieved based upon increased built-in potential and improved charge collection via the electron blocking effect of Al2O3. In addition, the hydrophilicity enhanced by Al2O3 improved the coating uniformity of the PEDOT:PSS layer, resulting in a further reduction in surface recombination.

  7. Weak-signal conversion from 1550nm to 532nm with 84% efficiency

    CERN Document Server

    Samblowski, Aiko; Baune, Christoph; Fiurasek, Jaromir; Schnabel, Roman

    2013-01-01

    We report on the experimental frequency conversion of a dim, coherent continuous-wave light field from 1550nm to 532nm with an external photon-number conversion efficiency of (84.4 +/- 1.5)%. We used sum-frequency generation, which was realized in a standing-wave cavity built around a periodically poled type I potassium titanyl phosphate (PPKTP) crystal, pumped by an intense field at 810 nm. Our result is in full agreement with a numerical model. For optimized cavity coupler reflectivities it predicts a conversion efficiency of up to 93% using the same PPKTP crystal.

  8. RIG-I Signaling Is Critical for Efficient Polyfunctional T Cell Responses during Influenza Virus Infection.

    Directory of Open Access Journals (Sweden)

    Matheswaran Kandasamy

    2016-07-01

    Full Text Available Retinoic acid inducible gene-I (RIG-I is an innate RNA sensor that recognizes the influenza A virus (IAV RNA genome and activates antiviral host responses. Here, we demonstrate that RIG-I signaling plays a crucial role in restricting IAV tropism and regulating host immune responses. Mice deficient in the RIG-I-MAVS pathway show defects in migratory dendritic cell (DC activation, viral antigen presentation, and priming of CD8+ and CD4+ T cell responses during IAV infection. These defects result in decreased frequency of polyfunctional effector T cells and lowered protection against heterologous IAV challenge. In addition, our data show that RIG-I activation is essential for protecting epithelial cells and hematopoietic cells from IAV infection. These diverse effects of RIG-I signaling are likely imparted by the actions of type I interferon (IFN, as addition of exogenous type I IFN is sufficient to overcome the defects in antigen presentation by RIG-I deficient BMDC. Moreover, the in vivo T cell defects in RIG-I deficient mice can be overcome by the activation of MDA5 -MAVS via poly I:C treatment. Taken together, these findings demonstrate that RIG-I signaling through MAVS is critical for determining the quality of polyfunctional T cell responses against IAV and for providing protection against subsequent infection from heterologous or novel pandemic IAV strains.

  9. RIG-I Signaling Is Critical for Efficient Polyfunctional T Cell Responses during Influenza Virus Infection

    Science.gov (United States)

    Kandasamy, Matheswaran; Suryawanshi, Amol; Tundup, Smanla; Perez, Jasmine T.; Schmolke, Mirco; Manicassamy, Santhakumar; Manicassamy, Balaji

    2016-01-01

    Retinoic acid inducible gene-I (RIG-I) is an innate RNA sensor that recognizes the influenza A virus (IAV) RNA genome and activates antiviral host responses. Here, we demonstrate that RIG-I signaling plays a crucial role in restricting IAV tropism and regulating host immune responses. Mice deficient in the RIG-I-MAVS pathway show defects in migratory dendritic cell (DC) activation, viral antigen presentation, and priming of CD8+ and CD4+ T cell responses during IAV infection. These defects result in decreased frequency of polyfunctional effector T cells and lowered protection against heterologous IAV challenge. In addition, our data show that RIG-I activation is essential for protecting epithelial cells and hematopoietic cells from IAV infection. These diverse effects of RIG-I signaling are likely imparted by the actions of type I interferon (IFN), as addition of exogenous type I IFN is sufficient to overcome the defects in antigen presentation by RIG-I deficient BMDC. Moreover, the in vivo T cell defects in RIG-I deficient mice can be overcome by the activation of MDA5 –MAVS via poly I:C treatment. Taken together, these findings demonstrate that RIG-I signaling through MAVS is critical for determining the quality of polyfunctional T cell responses against IAV and for providing protection against subsequent infection from heterologous or novel pandemic IAV strains. PMID:27438481

  10. Efficient calculation of inelastic vibration signals in electron transport: Beyond the wide-band approximation

    DEFF Research Database (Denmark)

    Lu, Jing Tao; Christensen, Rasmus Bjerregaard; Foti, Giuseppe;

    2014-01-01

    We extend the simple and efficient lowest order expansion (LOE) for inelastic electron tunneling spectroscopy (IETS) to include variations in the electronic structure on the scale of the vibration energies. This enables first-principles calculations of IETS line shapes for molecular junctions clo...

  11. Efficiency Wages : Signals or Incentives? An Empirical Study of the Relationship between Wage and Commitment

    NARCIS (Netherlands)

    Mühlau, Peter; Lindenberg, Siegwart

    2003-01-01

    Efficiency wage theories argue that firms induce their employees to work in a more disciplined way by paying high wages. Two basic mechanisms have been pointed out in economics about how these wage premia motivate employees. The incentives-driven ‘shirking model’ implies that employees who have a hi

  12. An Optimal Bahadur-Efficient Method in Detection of Sparse Signals with Applications to Pathway Analysis in Sequencing Association Studies.

    Directory of Open Access Journals (Sweden)

    Hongying Dai

    Full Text Available Next-generation sequencing data pose a severe curse of dimensionality, complicating traditional "single marker-single trait" analysis. We propose a two-stage combined p-value method for pathway analysis. The first stage is at the gene level, where we integrate effects within a gene using the Sequence Kernel Association Test (SKAT. The second stage is at the pathway level, where we perform a correlated Lancaster procedure to detect joint effects from multiple genes within a pathway. We show that the Lancaster procedure is optimal in Bahadur efficiency among all combined p-value methods. The Bahadur efficiency,[Formula: see text], compares sample sizes among different statistical tests when signals become sparse in sequencing data, i.e. ε →0. The optimal Bahadur efficiency ensures that the Lancaster procedure asymptotically requires a minimal sample size to detect sparse signals ([Formula: see text]. The Lancaster procedure can also be applied to meta-analysis. Extensive empirical assessments of exome sequencing data show that the proposed method outperforms Gene Set Enrichment Analysis (GSEA. We applied the competitive Lancaster procedure to meta-analysis data generated by the Global Lipids Genetics Consortium to identify pathways significantly associated with high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and total cholesterol.

  13. An Optimal Bahadur-Efficient Method in Detection of Sparse Signals with Applications to Pathway Analysis in Sequencing Association Studies.

    Science.gov (United States)

    Dai, Hongying; Wu, Guodong; Wu, Michael; Zhi, Degui

    2016-01-01

    Next-generation sequencing data pose a severe curse of dimensionality, complicating traditional "single marker-single trait" analysis. We propose a two-stage combined p-value method for pathway analysis. The first stage is at the gene level, where we integrate effects within a gene using the Sequence Kernel Association Test (SKAT). The second stage is at the pathway level, where we perform a correlated Lancaster procedure to detect joint effects from multiple genes within a pathway. We show that the Lancaster procedure is optimal in Bahadur efficiency among all combined p-value methods. The Bahadur efficiency,[Formula: see text], compares sample sizes among different statistical tests when signals become sparse in sequencing data, i.e. ε →0. The optimal Bahadur efficiency ensures that the Lancaster procedure asymptotically requires a minimal sample size to detect sparse signals ([Formula: see text]). The Lancaster procedure can also be applied to meta-analysis. Extensive empirical assessments of exome sequencing data show that the proposed method outperforms Gene Set Enrichment Analysis (GSEA). We applied the competitive Lancaster procedure to meta-analysis data generated by the Global Lipids Genetics Consortium to identify pathways significantly associated with high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and total cholesterol.

  14. A Novel Efficient Cluster-Based MLSE Equalizer for Satellite Communication Channels with -QAM Signaling

    Directory of Open Access Journals (Sweden)

    Dalakas Vassilis

    2006-01-01

    Full Text Available In satellites, nonlinear amplifiers used near saturation severely distort the transmitted signal and cause difficulties in its reception. Nevertheless, the nonlinearities introduced by memoryless bandpass amplifiers preserve the symmetries of the -ary quadrature amplitude modulation ( -QAM constellation. In this paper, a cluster-based sequence equalizer (CBSE that takes advantage of these symmetries is presented. The proposed equalizer exhibits enhanced performance compared to other techniques, including the conventional linear transversal equalizer, Volterra equalizers, and RBF network equalizers. Moreover, this gain in performance is obtained at a substantially lower computational cost.

  15. Water resources transfers through southern African food trade: water efficiency and climate signals

    Science.gov (United States)

    Dalin, Carole; Conway, Declan

    2016-01-01

    Temporal and spatial variability of precipitation in southern Africa is particularly high. The associated drought and flood risks, combined with a largely rain-fed agriculture, pose a challenge for water and food security in the region. As regional collaboration strengthens through the Southern Africa Development Community and trade with other regions increases, it is thus important to understand both how climate variability affects agricultural productivity and how food trade (regional and extra-regional) can contribute to the region's capacity to deal with climate-related shocks. We combine global hydrological model simulations with international food trade data to quantify the water resources embedded in international food trade in southern Africa and with the rest of the world, from 1986-2011. We analyze the impacts of socio-economic changes and climatic variability on agricultural trade and embedded water resources during this period. We find that regional food trade is efficient in terms of water use but may be unsustainable because water-productive exporters, like South Africa, rely on increasingly stressed water resources. The role of imports from the rest of the world in the region's food supply is important, in particular during severe droughts. This reflects how trade can efficiently redistribute water resources across continents in response to a sudden gap in food production. In a context of regional and global integration, our results highlight opportunities for improved water-efficiency and sustainability of the region's food supply via trade.

  16. Highly Functional TNTs with Superb Photocatalytic, Optical, and Electronic Performance Achieving Record PV Efficiency of 10.1% for 1D-Based DSSCs.

    Science.gov (United States)

    Qadir, Muhammad Bilal; Li, Yuewen; Sahito, Iftikhar Ali; Arbab, Alvira Ayoub; Sun, Kyung Chul; Mengal, Naveed; Memon, Anam Ali; Jeong, Sung Hoon

    2016-09-01

    Different nanostructures of TiO2 play an important role in the photocatalytic and photoelectronic applications. TiO2 nanotubes (TNTs) have received increasing attention for these applications due to their unique physicochemical properties. Focusing on highly functional TNTs (HF-TNTs) for photocatalytic and photoelectronic applications, this study describes the facile hydrothermal synthesis of HF-TNTs by using commercial and cheaper materials for cost-effective manufacturing. To prove the functionality and applicability, these TNTs are used as scattering structure in dye-sensitized solar cells (DSSCs). Photocatalytic, optical, Brunauer-Emmett-Teller (BET), electrochemical impedance spectrum, incident-photon-to-current efficiency, and intensity-modulated photocurrent spectroscopy/intensity-modulated photovoltage spectroscopy characterizations are proving the functionality of HF-TNTs for DSSCs. HF-TNTs show 50% higher photocatalytic degradation rate and also 68% higher dye loading ability than conventional TNTs (C-TNTs). The DSSCs having HF-TNT and its composite-based multifunctional overlayer show effective light absorption, outstanding light scattering, lower interfacial resistance, longer electron lifetime, rapid electron transfer, and improved diffusion length, and consequently, J SC , quantum efficiency, and record photoconversion efficiency of 10.1% using commercial N-719 dye is achieved, for 1D-based DSSCs. These new and highly functional TNTs will be a concrete fundamental background toward the development of more functional applications in fuel cells, dye-sensitized solar cells, Li-ion batteries, photocatalysis process, ion-exchange/adsorption process, and photoelectrochemical devices.

  17. Communication efficiency and congestion of signal traffic in large-scale brain networks.

    Science.gov (United States)

    Mišić, Bratislav; Sporns, Olaf; McIntosh, Anthony R

    2014-01-01

    The complex connectivity of the cerebral cortex suggests that inter-regional communication is a primary function. Using computational modeling, we show that anatomical connectivity may be a major determinant for global information flow in brain networks. A macaque brain network was implemented as a communication network in which signal units flowed between grey matter nodes along white matter paths. Compared to degree-matched surrogate networks, information flow on the macaque brain network was characterized by higher loss rates, faster transit times and lower throughput, suggesting that neural connectivity may be optimized for speed rather than fidelity. Much of global communication was mediated by a "rich club" of hub regions: a sub-graph comprised of high-degree nodes that are more densely interconnected with each other than predicted by chance. First, macaque communication patterns most closely resembled those observed for a synthetic rich club network, but were less similar to those seen in a synthetic small world network, suggesting that the former is a more fundamental feature of brain network topology. Second, rich club regions attracted the most signal traffic and likewise, connections between rich club regions carried more traffic than connections between non-rich club regions. Third, a number of rich club regions were significantly under-congested, suggesting that macaque connectivity actively shapes information flow, funneling traffic towards some nodes and away from others. Together, our results indicate a critical role of the rich club of hub nodes in dynamic aspects of global brain communication.

  18. Development and application of VISAR probe with higher signal-collecting efficiency and adjusted depth of field

    CERN Document Server

    Zhao Jian Heng; Sun Cheng Wei

    2001-01-01

    The new design of optical fiber VISAR probes has been described. It consists of optical fibers and two lenses, and has simpler structure and lower cost than others. If the size of the image near the end face of collecting fiber is larger than the diameter of the core fiber, the distance between the probe and the target can be decreased. Requirement for the precision in the design is lower in this way, and is easier to build up. At the same time, the signal-collecting efficiency is improved in some degree. During the process of designing the probe, the technique for manufacturing the lens of plexiglass is developed. The lens of plexiglass is used to replace the lens of glass, which can reduce the cost of the probe. The factors affecting the collecting efficiency are analyzed

  19. Kazakhstan can achieve ambitious HIV targets despite expected donor withdrawal by combining improved ART procurement mechanisms with allocative and implementation efficiencies

    Science.gov (United States)

    Benedikt, Clemens; Bokazhanova, Aliya; Đurić, Predrag; Petrenko, Irina; Ganina, Lolita; Kelly, Sherrie L.; Stuart, Robyn M.; Kerr, Cliff C.; Vinichenko, Tatiana; Zhang, Shufang; Hamelmann, Christoph; Manova, Manoela; Masaki, Emiko; Wilson, David P.; Gray, Richard T.

    2017-01-01

    Background Despite a non-decreasing HIV epidemic, international donors are soon expected to withdraw funding from Kazakhstan. Here we analyze how allocative, implementation, and technical efficiencies could strengthen the national HIV response under assumptions of future budget levels. Methodology We used the Optima model to project future scenarios of the HIV epidemic in Kazakhstan that varied in future antiretroviral treatment unit costs and management expenditure—two areas identified for potential cost-reductions. We determined optimal allocations across HIV programs to satisfy either national targets or ambitious targets. For each scenario, we considered two cases of future HIV financing: the 2014 national budget maintained into the future and the 2014 budget without current international investment. Findings Kazakhstan can achieve its national HIV targets with the current budget by (1) optimally re-allocating resources across programs and (2) either securing a 35% [30%–39%] reduction in antiretroviral treatment drug costs or reducing management costs by 44% [36%–58%] of 2014 levels. Alternatively, a combination of antiretroviral treatment and management cost-reductions could be sufficient. Furthermore, Kazakhstan can achieve ambitious targets of halving new infections and AIDS-related deaths by 2020 compared to 2014 levels by attaining a 67% reduction in antiretroviral treatment costs, a 19% [14%–27%] reduction in management costs, and allocating resources optimally. Significance With Kazakhstan facing impending donor withdrawal, it is important for the HIV response to achieve more with available resources. This analysis can help to guide HIV response planners in directing available funding to achieve the greatest yield from investments. The key changes recommended were considered realistic by Kazakhstan country representatives. PMID:28207809

  20. Sampling frequency, response times and embedded signal filtration in fast, high efficiency liquid chromatography: A tutorial.

    Science.gov (United States)

    Wahab, M Farooq; Dasgupta, Purnendu K; Kadjo, Akinde F; Armstrong, Daniel W

    2016-02-11

    With increasingly efficient columns, eluite peaks are increasingly narrower. To take full advantage of this, choice of the detector response time and the data acquisition rate a.k.a. detector sampling frequency, have become increasingly important. In this work, we revisit the concept of data sampling from the theorem variously attributed to Whittaker, Nyquist, Kotelnikov, and Shannon. Focusing on time scales relevant to the current practice of high performance liquid chromatography (HPLC) and optical absorbance detection (the most commonly used method), even for very narrow simulated peaks Fourier transformation shows that theoretical minimum sampling frequency is still relatively low (fast chromatography on a state-of-the-art column (38,000 plates), we evaluate the responses produced by different present generation instruments, each with their unique black box digital filters. We show that the common wisdom of sampling 20 points per peak can be inadequate for high efficiency columns and that the sampling frequency and response choices do affect the peak shape. If the sampling frequency is too low or response time is too large, the observed peak shapes will not remain as narrow as they really are - this is especially true for high efficiency and high speed separations. It is shown that both sampling frequency and digital filtering affect the retention time, noise amplitude, peak shape and width in a complex fashion. We show how a square-wave driven light emitting diode source can reveal the nature of the embedded filter. We discuss time uncertainties related to the choice of sampling frequency. Finally, we suggest steps to obtain optimum results from a given system.

  1. Mixed-Signal Architectures for High-Efficiency and Low-Distortion Digital Audio Processing and Power Amplification

    Directory of Open Access Journals (Sweden)

    Pierangelo Terreni

    2010-01-01

    Full Text Available The paper addresses the algorithmic and architectural design of digital input power audio amplifiers. A modelling platform, based on a meet-in-the-middle approach between top-down and bottom-up design strategies, allows a fast but still accurate exploration of the mixed-signal design space. Different amplifier architectures are configured and compared to find optimal trade-offs among different cost-functions: low distortion, high efficiency, low circuit complexity and low sensitivity to parameter changes. A novel amplifier architecture is derived; its prototype implements digital processing IP macrocells (oversampler, interpolating filter, PWM cross-point deriver, noise shaper, multilevel PWM modulator, dead time compensator on a single low-complexity FPGA while off-chip components are used only for the power output stage (LC filter and power MOS bridge; no heatsink is required. The resulting digital input amplifier features a power efficiency higher than 90% and a total harmonic distortion down to 0.13% at power levels of tens of Watts. Discussions towards the full-silicon integration of the mixed-signal amplifier in embedded devices, using BCD technology and targeting power levels of few Watts, are also reported.

  2. High Speed and Area Efficient 2D DWT Processor based Image Compression" Signal & Image Processing

    CERN Document Server

    Kaur, Sugreev

    2011-01-01

    This paper presents a high speed and area efficient DWT processor based design for Image Compression applications. In this proposed design, pipelined partially serial architecture has been used to enhance the speed along with optimal utilization and resources available on target FPGA. The proposed model has been designed and simulated using Simulink and System Generator blocks, synthesized with Xilinx Synthesis tool (XST) and implemented on Spartan 2 and 3 based XC2S100-5tq144 and XC3S500E-4fg320 target device. The results show that proposed design can operate at maximum frequency 231 MHz in case of Spartan 3 by consuming power of 117mW at 28 degree/c junction temperature. The result comparison has shown an improvement of 15% in speed.

  3. Biometric Methods for Secure Communications in Body Sensor Networks: Resource-Efficient Key Management and Signal-Level Data Scrambling

    Directory of Open Access Journals (Sweden)

    Dimitrios Hatzinakos

    2008-03-01

    Full Text Available As electronic communications become more prevalent, mobile and universal, the threats of data compromises also accordingly loom larger. In the context of a body sensor network (BSN, which permits pervasive monitoring of potentially sensitive medical data, security and privacy concerns are particularly important. It is a challenge to implement traditional security infrastructures in these types of lightweight networks since they are by design limited in both computational and communication resources. A key enabling technology for secure communications in BSN's has emerged to be biometrics. In this work, we present two complementary approaches which exploit physiological signals to address security issues: (1 a resource-efficient key management system for generating and distributing cryptographic keys to constituent sensors in a BSN; (2 a novel data scrambling method, based on interpolation and random sampling, that is envisioned as a potential alternative to conventional symmetric encryption algorithms for certain types of data. The former targets the resource constraints in BSN's, while the latter addresses the fuzzy variability of biometric signals, which has largely precluded the direct application of conventional encryption. Using electrocardiogram (ECG signals as biometrics, the resulting computer simulations demonstrate the feasibility and efficacy of these methods for delivering secure communications in BSN's.

  4. Biometric Methods for Secure Communications in Body Sensor Networks: Resource-Efficient Key Management and Signal-Level Data Scrambling

    Science.gov (United States)

    Bui, Francis Minhthang; Hatzinakos, Dimitrios

    2007-12-01

    As electronic communications become more prevalent, mobile and universal, the threats of data compromises also accordingly loom larger. In the context of a body sensor network (BSN), which permits pervasive monitoring of potentially sensitive medical data, security and privacy concerns are particularly important. It is a challenge to implement traditional security infrastructures in these types of lightweight networks since they are by design limited in both computational and communication resources. A key enabling technology for secure communications in BSN's has emerged to be biometrics. In this work, we present two complementary approaches which exploit physiological signals to address security issues: (1) a resource-efficient key management system for generating and distributing cryptographic keys to constituent sensors in a BSN; (2) a novel data scrambling method, based on interpolation and random sampling, that is envisioned as a potential alternative to conventional symmetric encryption algorithms for certain types of data. The former targets the resource constraints in BSN's, while the latter addresses the fuzzy variability of biometric signals, which has largely precluded the direct application of conventional encryption. Using electrocardiogram (ECG) signals as biometrics, the resulting computer simulations demonstrate the feasibility and efficacy of these methods for delivering secure communications in BSN's.

  5. Efficient and Robust Detection of GFSK Signals under Dispersive Channel, Modulation Index, and Carrier Frequency Offset Conditions

    Directory of Open Access Journals (Sweden)

    Stephan Weiss

    2005-09-01

    Full Text Available Gaussian frequency shift keying is the modulation scheme specified for Bluetooth. Signal adversities typical in Bluetooth networks include AWGN, multipath propagation, carrier frequency, and modulation index offsets. In our effort to realise a robust but efficient Bluetooth receiver, we adopt a high-performance matched-filter-based detector, which is near optimal in AWGN, but requires a prohibitively costly filter bank for processing of K bits worth of the received signal. However, through filtering over a single bit period and performing phase propagation of intermediate results over successive single-bit stages, we eliminate redundancy involved in providing the matched filter outputs and reduce its complexity by up to 90% (for K=9. The constant modulus signal characteristic and the potential for carrier frequency offsets make the constant modulus algorithm (CMA suitable for channel equalisation, and we demonstrate its effectiveness in this paper. We also introduce a stochastic gradient-based algorithm for carrier frequency offset correction, and show that the relative rotation between successive intermediate filter outputs enables us to detect and correct offsets in modulation index.

  6. A CMOS power-efficient low-noise current-mode front-end amplifier for neural signal recording.

    Science.gov (United States)

    Wu, Chung-Yu; Chen, Wei-Ming; Kuo, Liang-Ting

    2013-04-01

    In this paper, a new current-mode front-end amplifier (CMFEA) for neural signal recording systems is proposed. In the proposed CMFEA, a current-mode preamplifier with an active feedback loop operated at very low frequency is designed as the first gain stage to bypass any dc offset current generated by the electrode-tissue interface and to achieve a low high-pass cutoff frequency below 0.5 Hz. No reset signal or ultra-large pseudo resistor is required. The current-mode preamplifier has low dc operation current to enhance low-noise performance and decrease power consumption. A programmable current gain stage is adopted to provide adjustable gain for adaptive signal scaling. A following current-mode filter is designed to adjust the low-pass cutoff frequency for different neural signals. The proposed CMFEA is designed and fabricated in 0.18-μm CMOS technology and the area of the core circuit is 0.076 mm(2). The measured high-pass cutoff frequency is as low as 0.3 Hz and the low-pass cutoff frequency is adjustable from 1 kHz to 10 kHz. The measured maximum current gain is 55.9 dB. The measured input-referred current noise density is 153 fA /√Hz , and the power consumption is 13 μW at 1-V power supply. The fabricated CMFEA has been successfully applied to the animal test for recording the seizure ECoG of Long-Evan rats.

  7. Time-frequency texture descriptors of EEG signals for efficient detection of epileptic seizure.

    Science.gov (United States)

    Şengür, Abdulkadir; Guo, Yanhui; Akbulut, Yaman

    2016-06-01

    Detection of epileptic seizure in electroencephalogram (EEG) signals is a challenging task and requires highly skilled neurophysiologists. Therefore, computer-aided detection helps neurophysiologist in interpreting the EEG. In this paper, texture representation of the time-frequency (t-f) image-based epileptic seizure detection is proposed. More specifically, we propose texture descriptor-based features to discriminate normal and epileptic seizure in t-f domain. To this end, three popular texture descriptors are employed, namely gray-level co-occurrence matrix (GLCM), texture feature coding method (TFCM), and local binary pattern (LBP). The features that are obtained on the GLCM are contrast, correlation, energy, and homogeneity. Moreover, in the TFCM method, several statistical features are calculated. In addition, for the LBP, the histogram is used as a feature. In the classification stage, a support vector machine classifier is employed. We evaluate our proposal with extensive experiments. According to the evaluated terms, our method produces successful results. 100 % accuracy is obtained with LIBLINEAR. We also compare our method with other published methods and the results show the superiority of our proposed method.

  8. Interferometric Motion Detection in Atomic Layer 2D Nanostructures: Visualizing Signal Transduction Efficiency and Optimization Pathways

    Science.gov (United States)

    Wang, Zenghui; Feng, Philip X.-L.

    2016-07-01

    Atomic layer crystals are emerging building blocks for enabling new two-dimensional (2D) nanomechanical systems, whose motions can be coupled to other attractive physical properties in such 2D systems. Optical interferometry has been very effective in reading out the infinitesimal motions of these 2D structures and spatially resolving different modes. To quantitatively understand the detection efficiency and its dependence on the device parameters and interferometric conditions, here we present a systematic study of the intrinsic motion responsivity in 2D nanomechanical systems using a Fresnel-law-based model. We find that in monolayer to 14-layer structures, MoS2 offers the highest responsivity among graphene, h-BN, and MoS2 devices and for the three commonly used visible laser wavelengths (633, 532, and 405 nm). We also find that the vacuum gap resulting from the widely used 300 nm-oxide substrate in making 2D devices, fortunately, leads to close-to-optimal responsivity for a wide range of 2D flakes. Our results elucidate and graphically visualize the dependence of motion transduction responsivity upon 2D material type and number of layers, vacuum gap, oxide thickness, and detecting wavelength, thus providing design guidelines for constructing 2D nanomechanical systems with optimal optical motion readout.

  9. Overexpression of AtABCG25 enhances the abscisic acid signal in guard cells and improves plant water use efficiency.

    Science.gov (United States)

    Kuromori, Takashi; Fujita, Miki; Urano, Kaoru; Tanabata, Takanari; Sugimoto, Eriko; Shinozaki, Kazuo

    2016-10-01

    In addition to improving drought tolerance, improvement of water use efficiency is a major challenge in plant physiology. Due to their trade-off relationships, it is generally considered that achieving stress tolerance is incompatible with maintaining stable growth. Abscisic acid (ABA) is a key phytohormone that regulates the balance between intrinsic growth and environmental responses. Previously, we identified AtABCG25 as a cell-membrane ABA transporter that export ABA from the inside to the outside of cells. AtABCG25-overexpressing plants showed a lower transpiration phenotype without any growth retardation. Here, we dissected this useful trait using precise phenotyping approaches. AtABCG25 overexpression stimulated a local ABA response in guard cells. Furthermore, AtABCG25 overexpression enhanced drought tolerance, probably resulting from maintenance of water contents over the common threshold for survival after drought stress treatment. Finally, we observed enhanced water use efficiency by overexpression of AtABCG25, in addition to drought tolerance. These results were consistent with the function of AtABCG25 as an ABA efflux transporter. This unique trait may be generally useful for improving the water use efficiency and drought tolerance of plants.

  10. Correlated Equilibria of Classical Strategic Games with Quantum Signals

    CERN Document Server

    La Mura, P

    2003-01-01

    Correlated equilibria are sometimes more efficient than the Nash equilibria of a game without signals. We investigate whether the availability of quantum signals in the context of a classical strategic game may allow the players to achieve even better efficiency than in any correlated equilibrium with classical signals, and find the answer to be positive.

  11. Data-Driven Sampling Matrix Boolean Optimization for Energy-Efficient Biomedical Signal Acquisition by Compressive Sensing.

    Science.gov (United States)

    Wang, Yuhao; Li, Xin; Xu, Kai; Ren, Fengbo; Yu, Hao

    2017-04-01

    Compressive sensing is widely used in biomedical applications, and the sampling matrix plays a critical role on both quality and power consumption of signal acquisition. It projects a high-dimensional vector of data into a low-dimensional subspace by matrix-vector multiplication. An optimal sampling matrix can ensure accurate data reconstruction and/or high compression ratio. Most existing optimization methods can only produce real-valued embedding matrices that result in large energy consumption during data acquisition. In this paper, we propose an efficient method that finds an optimal Boolean sampling matrix in order to reduce the energy consumption. Compared to random Boolean embedding, our data-driven Boolean sampling matrix can improve the image recovery quality by 9 dB. Moreover, in terms of sampling hardware complexity, it reduces the energy consumption by 4.6× and the silicon area by 1.9× over the data-driven real-valued embedding.

  12. Energy-Efficient Full Diversity Collaborative Unitary Space-Time Block Code Design via Unique Factorization of Signals

    CERN Document Server

    Xia, Dong; Dumitrescu, Sorina

    2011-01-01

    In this paper, a novel concept called a \\textit{uniquely factorable constellation pair} (UFCP) is proposed for the systematic design of a noncoherent full diversity collaborative unitary space-time block code by normalizing two Alamouti codes for a wireless communication system having two transmitter antennas and a single receiver antenna. It is proved that such a unitary UFCP code assures the unique identification of both channel coefficients and transmitted signals in a noise-free case as well as full diversity for the noncoherent maximum likelihood (ML) receiver in a noise case. To further improve error performance, an optimal unitary UFCP code is designed by appropriately and uniquely factorizing a pair of energy-efficient cross quadrature amplitude modulation (QAM) constellations to maximize the coding gain subject to a transmission bit rate constraint. After a deep investigation of the fractional coding gain function, a technical approach developed in this paper to maximizing the coding gain is to caref...

  13. Damage localization using a power-efficient distributed on-board signal processing algorithm in a wireless sensor network

    Science.gov (United States)

    Liu, Lei; Liu, Shuntao; Yuan, Fuh-Gwo

    2012-02-01

    A distributed on-board algorithm that is embedded and executed within a group of wireless sensors to locate structural damages in isotropic plates is presented. The algorithm is based on an energy-decay model of Lamb waves and singular value decomposition (SVD) to determine damage locations. A sensor group consists of a small number of sensors, each of which independently collects wave signals and evaluates wave energy upon an external triggering signal sent from a base station. The energy values, usually a few bytes in length, are then sent to the base station to determine the presence and location of damages. In comparison with traditional centralized approaches in which whole datasets are required to be transmitted, the proposed algorithm yields much less wireless communication traffic, yet with a modest amount of computation required within sensors. Experiments have shown that the algorithm is robust to locate damage for isotropic plate structures and is very power efficient, with more than an order-of-magnitude power saving.

  14. Simple combination of oxidants with zero-valent-iron (ZVI) achieved very rapid and highly efficient removal of heavy metals from water.

    Science.gov (United States)

    Guo, Xuejun; Yang, Zhe; Dong, Haiyang; Guan, Xiaohong; Ren, Qidong; Lv, Xiaofang; Jin, Xin

    2016-01-01

    This study, for the first time, demonstrated a continuously accelerated Fe(0) corrosion driven by common oxidants (i.e., NaClO, KMnO4 or H2O2) and thereby the rapid and efficient removal of heavy metals (HMs) by zero-valent iron (ZVI) under the experimental conditions of jar tests and column running. ZVI simply coupled with NaClO, KMnO4 or H2O2 (0.5 mM) resulted in almost complete As(V) removal within only 10 min with 1000 μg/L of initial As(V) at initial pH of 7.5(±0.1) and liquid solid ratio of 200:1. Simultaneous removal of 200 μg/L of initial Cd(II) and Hg(II) to 2.4-4.4 μg/L for Cd(II) and to 4.0-5.0 μg/L for Hg(II) were achieved within 30 min. No deterioration of HM removal was observed during the ten recycles of jar tests. The ZVI columns activated by 0.1 mM of oxidants had stably treated 40,200 (NaClO), 20,295 (KMnO4) and 40,200 (H2O2) bed volumes (BV) of HM-contaminated drinking water, but with no any indication of As breakthrough (removal from both the jar tests and column running implied a continuous and stable activation (overcoming of iron passivation) of Fe(0) surface by the oxidants. Via the proper increase in oxidant dosing, the ZVI/oxidant combination was applicable to treat highly As(V)-contaminated wastewater. During Fe(0) surface corrosion accelerated by oxidants, a large amount of fresh and reactive iron oxides and oxyhydroxides were continuously generated, which were responsible for the rapid and efficient removal of HMs through multiple mechanisms including adsorption and co-precipitation. A steady state of Fe(0) surface activation and HM removal enabled this simply coupled system to remove HMs with high speed, efficiency and perdurability.

  15. Serum starvation and thymidine double blocking achieved efficient cell cycle synchronization and altered the expression of p27, p53, bcl-2 in canine breast cancer cells.

    Science.gov (United States)

    Tong, Jinjin; Sun, Dongdong; Yang, Chao; Wang, Yingxue; Sun, Sichao; Li, Qing; Bao, Jun; Liu, Yun

    2016-04-01

    Cell synchronization is an approach to obtain cell populations of the same stage, which is a prerequisite to studying the regulation of cell cycle progression in vivo. Serum starvation and thymidine double blocking (TdR) are two important practices in studying cell cycle synchronization. However, their effects on canine cancer cells as well as the regulatory mechanisms by these two methods are poorly understood. In this study, we determined the optimum conditions of serum starvation and TdR and their effects on cell cycle synchronization. We further explored the involvement of PI3K/Akt signaling pathway in the cell cycle synchronization by investigating the expression of three key genes (p27, p53 and bcl-2). Serum starvation resulted in a reversible cell cycle arrest and synchronously progress through G0/G1. The highest percentage of CHMm cells (87.47%) in G0/G1 stage was obtained after 42 h incubation with 0.5% fetal bovine serum (FBS). TdR double blocking could arrest 98.9% of CHMm cells in G1/S phase (0 h of release), and could arrest 93.74% of CHMm cells in S phase after 4h of release. We also found that the p27, p53, bcl-2 genes were most highly expressed in G0/G1 phase. Our current work revealed that serum starvation and TdR methods could achieve sufficient synchronization of CHMm cells. Moreover, the expression of p27, p53 and bcl-2 genes was related to cyclical movements and apoptosis. Our results will provide a new insight into cell cycle regulation and reprogramming of canine cancer cells induced by serum starvation and TdR blocking.

  16. Design and Implementation of an Efficient Software Communications Architecture Core Framework for a Digital Signal Processors Platform

    Directory of Open Access Journals (Sweden)

    Wael A. Murtada

    2011-01-01

    Full Text Available Problem statement: The Software Communications Architecture (SCA was developed to improve software reuse and interoperability in Software Defined Radios (SDR. However, there have been performance concerns since its conception. Arguably, the majority of the problems and inefficiencies associated with the SCA can be attributed to the assumption of modular distributed platforms relying on General Purpose Processors (GPPs to perform all signal processing. Approach: Significant improvements in cost and power consumption can be obtained by utilizing specialized and more efficient platforms. Digital Signal Processors (DSPs present such a platform and have been widely used in the communications industry. Improvements in development tools and middleware technology opened the possibility of fully integrating DSPs into the SCA. This approach takes advantage of the exceptional power, cost and performance characteristics of DSPs, while still enjoying the flexibility and portability of the SCA. Results: This study presents the design and implementation of an SCA Core Framework (CF for a TI TMS320C6416 DSP. The framework is deployed on a C6416 Device Cycle Accurate Simulator and TI C6416 Development board. The SCA CF is implemented by leveraging OSSIE, an open-source implementation of the SCA, to support the DSP platform. OIS’s ORBExpress DSP and DSP/BIOS are used as the middleware and operating system, respectively. A sample waveform was developed to demonstrate the framework’s functionality. Benchmark results for the framework and sample applications are provided. Conclusion: Benchmark results show that, using OIS ORBExpress DSP ORB middleware has an impact for decreasing the Software Memory Footprint and increasing the System Performance compared with PrismTech's e*ORB middleware.

  17. Daily energy balance in growth hormone receptor/binding protein (GHR−/−) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency

    Science.gov (United States)

    Longo, Kenneth A.; Berryman, Darlene E.; Kelder, Bruce; Charoenthongtrakul, Soratree; DiStefano, Peter S.; Geddes, Brad J.; Kopchick, John

    2009-01-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR −/− mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (Mb) changes and physical activity in 17 month-old female GHR −/− mice and their age-matched wild type littermates. The GHR −/− mice were smaller, consumed more food per unit Mb, had greater EE per unit Mb and had an increase in 24-h EE/Mb that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR −/− mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, Mb and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for Mb and LMA, the GHR −/− mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR −/− mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR −/− mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final three hours of the dark phase. Therefore, we conclude that GHR −/− mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable Mb. Relative to wild type mice, the GHR −/− mice consumed more calories per unit Mb, which offset the disproportionate increase in their daily energy expenditure. While GHR −/− mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

  18. High Efficiency Wavelength Conversion of 40 Gbps Signals at 1550 nm in SOI Nano-Rib Waveguides Using p-i-n Diodes

    DEFF Research Database (Denmark)

    Gajda, Andrzej; Da Ros, Francesco; Vukovic, Dragana;

    2013-01-01

    We demonstrate enhancement of FWM wavelength conversion of a 40 Gbps signal in a reverse-biased p-i-n junction silicon waveguide. A conversion efficiency of −4.6 dB enables a conversion power penalty as low as 0.2 dB.......We demonstrate enhancement of FWM wavelength conversion of a 40 Gbps signal in a reverse-biased p-i-n junction silicon waveguide. A conversion efficiency of −4.6 dB enables a conversion power penalty as low as 0.2 dB....

  19. Generic System Verilog Universal Verification Methodology Based Reusable Verification Environment for Efficient Verification of Image Signal Processing IPS/SOCS

    Directory of Open Access Journals (Sweden)

    Abhishek Jain

    2012-12-01

    Full Text Available In this paper, we present Generic System Verilog Universal Verification Methodology based Reusable Verification Environment for efficient verification of Image Signal Processing IP’s/SoC’s. With the tight schedules on all projects it is important to have a strong verification methodology which contributes to First Silicon Success. Deploy methodologies which enforce full functional coverage and verification of corner cases through pseudo random test scenarios is required. Also, standardization of verification flow is needed. Previously, inside imaging group of ST, Specman (e/Verilog based Verification Environment forIP/Subsystem level verification and C/C++/Verilog based Directed Verification Environment for SoC Level Verification was used for Functional Verification. Different Verification Environments were used at IP level and SoC level. Different Verification/Validation Methodologies were used for SoC Verification across multiple sites. Verification teams were also looking for the ways how to catch bugs early in the design cycle? Thus, Generic System Verilog Universal Verification Methodology (UVM based Reusable Verification Environment is required to avoid the problem of having so many methodologies and provides a standard unified solution which compiles on all tools.

  20. Limits, discovery and cut optimization for a Poisson process with uncertainty in background and signal efficiency: TRolke 2.0

    Science.gov (United States)

    Lundberg, J.; Conrad, J.; Rolke, W.; Lopez, A.

    2010-03-01

    A C++ class was written for the calculation of frequentist confidence intervals using the profile likelihood method. Seven combinations of Binomial, Gaussian, Poissonian and Binomial uncertainties are implemented. The package provides routines for the calculation of upper and lower limits, sensitivity and related properties. It also supports hypothesis tests which take uncertainties into account. It can be used in compiled C++ code, in Python or interactively via the ROOT analysis framework. Program summaryProgram title: TRolke version 2.0 Catalogue identifier: AEFT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: MIT license No. of lines in distributed program, including test data, etc.: 3431 No. of bytes in distributed program, including test data, etc.: 21 789 Distribution format: tar.gz Programming language: ISO C++. Computer: Unix, GNU/Linux, Mac. Operating system: Linux 2.6 (Scientific Linux 4 and 5, Ubuntu 8.10), Darwin 9.0 (Mac-OS X 10.5.8). RAM:˜20 MB Classification: 14.13. External routines: ROOT ( http://root.cern.ch/drupal/) Nature of problem: The problem is to calculate a frequentist confidence interval on the parameter of a Poisson process with statistical or systematic uncertainties in signal efficiency or background. Solution method: Profile likelihood method, Analytical Running time:<10 seconds per extracted limit.

  1. Retinoic acid signalling is required for the efficient differentiation of CD4+ T cells into pathogenic effector cells during the development of intestinal inflammation

    DEFF Research Database (Denmark)

    Rivollier, Aymeric Marie Christian; Pool, Lieneke; Frising, Ulrika

    , it was also very recently reported to be essential for the stability of the Th1 lineage and to prevent transition to a Th17 program. Here we explored the role of RA signalling in CD4+ T cells during the development of intestinal inflammation in the T cell transfer colitis model. We found that RA signalling....... In vitro studies confirm the inefficacy of RA signalling-deficient T cells to generate bona fide Th1 cells and demonstrate their aberrant increased RORγt expression while their differentiation into Th17 remains unaffected. Surprisingly, RA signalling-deficient CD45RBlo regulatory T cells (Tregs......) are however as efficient as their RA signalling-competent counterparts to inhibit colitis development. Together our results indicate that RA, through its receptor RARα, negatively regulates the early expansion of CD4+ T cells during colitis and is necessary for the generation of colitogenic Th1/Th17 cells...

  2. Design of high-resolution and multilevel reference pattern for improvement of both light utilization efficiency and signal-to-noise ratio in coaxial holographic data storage.

    Science.gov (United States)

    Nobukawa, Teruyoshi; Nomura, Takanori

    2014-06-10

    A high-resolution and multilevel designed reference pattern (DRP) is presented for improvement of both light utilization efficiency and the signal-to-noise ratio (SNR) of reconstructed images in coaxial holographic data storage. With a DRP, the desired Fourier power spectrum of a reference beam is obtained. Numerical and experimental results show that the DRP increases the SNR compared with that of a random phase mask (RPM). Moreover, the light utilization efficiency of the DRP is higher than that of a high-resolution RPM. In addition, the effect of the phase level and the pixel pitch of DRPs on the SNR and the light utilization efficiency are investigated.

  3. On the (In)Efficiency of the Cross-Correlation Statistic for Gravitational Wave Stochastic Background Signals with Non-Gaussian Noise and Heterogeneous Detector Sensitivities

    CERN Document Server

    Lionel, Martellini

    2015-01-01

    Under standard assumptions including stationary and serially uncorrelated Gaussian gravitational wave stochastic background signal and noise distributions, as well as homogenous detector sensitivities, the standard cross-correlation detection statistic is known to be optimal in the sense of minimizing the probability of a false dismissal at a fixed value of the probability of a false alarm. The focus of this paper is to analyze the comparative efficiency of this statistic, versus a simple alternative statistic obtained by cross-correlating the \\textit{squared} measurements, in situations that deviate from such standard assumptions. We find that differences in detector sensitivities have a large impact on the comparative efficiency of the cross-correlation detection statistic, which is dominated by the alternative statistic when these differences reach one order of magnitude. This effect holds even when both the signal and noise distributions are Gaussian. While the presence of non-Gaussian signals has no mate...

  4. Differential pathway coupling efficiency of the activated insulin receptor drives signaling selectivity by xmeta, an allosteric partial agonist antibody

    Science.gov (United States)

    XMetA, an anti-insulin receptor (IR) monoclonal antibody, is an allosteric partial agonist of the IR. We have previously reported that XMetA activates the “metabolic-biased” Akt kinase signaling pathway while having little or no effect on the “mitogenic” MAPK signaling pathwayof ERK 1/2. To inves...

  5. Examining the Impact of an Integrative Method of Using Technology on Students' Achievement and Efficiency of Computer Usage and on Pedagogical Procedure in Geometry

    Science.gov (United States)

    Gurevich, Irina; Gurev, Dvora

    2012-01-01

    In the current study we follow the development of the pedagogical procedure for the course "Constructions in Geometry" that resulted from using dynamic geometry software (DGS), where the computer became an integral part of the educational process. Furthermore, we examine the influence of integrating DGS into the course on students' achievement and…

  6. A Simple Configuration for 40 Gbit/s CSRZ Signal Generation with Electrical Band-Limiting to Achieve Large Dispersion Tolerance

    Institute of Scientific and Technical Information of China (English)

    Dong-Soo; Lee; Man; Seop; Lee; Ampalavanapillai; Nirmalathas

    2003-01-01

    We present a novel configuration for carrier suppressed return-to-zero (CSRZ) signal generation, which only requires a single stage Mach-Zehnder (MZ) modulator in conjunction with an electrical mixer. Electrical band-limiting is also introduced to increase dispersion tolerance without causing additional penalty due to nonlinear effects in long haul dense wavelength division multiplexed (DWDM) CSRZ systems using conventional launch power levels.

  7. Infrared Signal Detection by Upconversion Technique

    Science.gov (United States)

    Wong, Teh-Hwa; Yu, Jirong; Bai, Yingxin; Johnson, William E.

    2014-01-01

    We demonstrated up-conversion assisted detection of a 2.05-micron signal by using a bulk periodically poled Lithium niobate crystal. The 94% intrinsic up-conversion efficiency and 22.58% overall detection efficiency at pW level of 2.05-micron was achieved.

  8. Enzyme-catalysed deposition of ultrathin silver shells on gold nanorods: a universal and highly efficient signal amplification strategy for translating immunoassay into a litmus-type test.

    Science.gov (United States)

    Yang, Xinjian; Gao, Zhiqiang

    2015-04-25

    On the basis of enzyme-catalysed reduction of silver ions and consequent deposition of ultrathin silver shells on gold nanorods, a highly efficient signal amplification method for immunoassay is developed. For a model analyte prostate-specific antigen, a 10(4)-fold improvement over conventional enzyme-linked immunosorbent assay is accomplished by leveraging on the cumulative nature of the enzymatic reaction and the sensitive response of plasnomic gold nanorods to the deposition the silver shells.

  9. Development of an efficient signal amplification strategy for label-free enzyme immunoassay using two site-specific biotinylated recombinant proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jin-Bao [School of Pharmacy, Weifang Medical University, Weifang 261053 (China); Tang, Ying [Affiliated Hospital of Weifang Medical University, Weifang 261041 (China); Yang, Hong-Ming, E-mail: yanghongming2006@sohu.com [School of Pharmacy, Weifang Medical University, Weifang 261053 (China)

    2015-02-15

    Highlights: • An efficient signal amplification strategy for label-free EIA is proposed. • Divalent biotinylated AP and monovalent biotinylated ZZ were prepared via Avitag–BirA system. • The above site-specific biotinylated fusion proteins form complex via SA–biotin interaction. • The mechanism relies on the ZZ–Avi-B/SA/AP–(Avi-B){sub 2} complex. • The analytical signals are enhanced (32-fold) by the proposed strategy. - Abstract: Constructing a recombinant protein between a reporter enzyme and a detector protein to produce a homogeneous immunological reagent is advantageous over random chemical conjugation. However, the approach hardly recombines multiple enzymes in a difunctional fusion protein, which results in insufficient amplification of the enzymatic signal, thereby limiting its application in further enhancement of analytical signal. In this study, two site-specific biotinylated recombinant proteins, namely, divalent biotinylated alkaline phosphatase (AP) and monovalent biotinylated ZZ domain, were produced by employing the Avitag–BirA system. Through the high streptavidin (SA)–biotin interaction, the divalent biotinylated APs were clustered in the SA–biotin complex and then incorporated with the biotinylated ZZ. This incorporation results in the formation of a functional macromolecule that involves numerous APs, thereby enhancing the enzymatic signal, and in the production of several ZZ molecules for the interaction with immunoglobulin G (IgG) antibody. The advantage of this signal amplification strategy is demonstrated through ELISA, in which the analytical signal was substantially enhanced, with a 32-fold increase in the detection sensitivity compared with the ZZ–AP fusion protein approach. The proposed immunoassay without chemical modification can be an alternative strategy to enhance the analytical signals in various applications involving immunosensors and diagnostic chips, given that the label-free IgG antibody is suitable

  10. 科技成果市场转化模式与效率评价研究%Research on the Model and Efficiency Evaluation of the Market Transformation of Scientific and Technological Achievements

    Institute of Scientific and Technical Information of China (English)

    戚湧; 朱婷婷; 郭逸

    2015-01-01

    分析科技成果转化的国内外管理和研究现状,对科技成果分类进行界定,研究不同类别科技成果的转化模式,得出专用技术成果转化应充分发挥市场的主导性作用;基于委托代理模型进行科技成果市场转化分析,得出由于成果生产方在科技成果市场转化中处于信息劣势,通过市场依托科技中介服务机构能够更好地促进科技成果转化;以江苏高校为对象进行科技成果市场转化效率评价研究和实证分析,结果表明江苏高校科技成果市场转化效率还不高;最后,针对研究结论提出促进科技成果市场转化的对策建议。%Analyzes the status of management and research of scientific and technological achievements transformation at home and abroad,defines the categories of scientific and technological achievements,studies the transformation pattern of different categories of scientific and technological achievements. The results show that market in the special technical achievements transformation should fully play a leading role;Research the principal-agent model of production of scientific and technological achievements and science and technology intermediary service agencies,and the results show that the production of scientific and technological achievements is in the information inferiority in the market transformation of scientific and technological achievements,and through market,the use of science and technology intermediary service agencies to more effectively promote the transformation of scientific and technological achievements;Taking the universities in Jiangsu as object,to study on market efficiency evaluation of the transformation of scientific and technological achievements,results show that the market efficiency of the scientific and technological achievements transformation is not high in Jiangsu university;Finally, according to the conclusions,we put forward suggestions to promote the transformation

  11. Cleavable DNA-protein hybrid molecular beacon: A novel efficient signal translator for sensitive fluorescence anisotropy bioassay.

    Science.gov (United States)

    Hu, Pan; Yang, Bin

    2016-01-15

    Due to its unique features such as high sensitivity, homogeneous format, and independence on fluorescent intensity, fluorescence anisotropy (FA) assay has become a hotspot of study in oligonucleotide-based bioassays. However, until now most FA probes require carefully customized structure designs, and thus are neither generalizable for different sensing systems nor effective to obtain sufficient signal response. To address this issue, a cleavable DNA-protein hybrid molecular beacon was successfully engineered for signal amplified FA bioassay, via combining the unique stable structure of molecular beacon and the large molecular mass of streptavidin. Compared with single DNA strand probe or conventional molecular beacon, the DNA-protein hybrid molecular beacon exhibited a much higher FA value, which was potential to obtain high signal-background ratio in sensing process. As proof-of-principle, this novel DNA-protein hybrid molecular beacon was further applied for FA bioassay using DNAzyme-Pb(2+) as a model sensing system. This FA assay approach could selectively detect as low as 0.5nM Pb(2+) in buffer solution, and also be successful for real samples analysis with good recovery values. Compatible with most of oligonucleotide probes' designs and enzyme-based signal amplification strategies, the molecular beacon can serve as a novel signal translator to expand the application prospect of FA technology in various bioassays.

  12. Sensitive Infrared Signal Detection by Upconversion Technique

    Science.gov (United States)

    Wong, Teh-Hwa; Yu, Jirong; Bai, Yingxin; Johnson, William; Chen, Songsheng; Petros, Mulugeta; Singh, Upendra N.

    2014-01-01

    We demonstrated upconversion assisted detection of a 2.05-micron signal by sum frequency generation to generate a 700-nm light using a bulk periodically poled lithium niobate crystal. The achieved 94% intrinsic upconversion efficiency and 22.58% overall detection efficiency at a pW level of 2.05 micron pave the path to detect extremely weak infrared (IR) signals for remote sensing applications.

  13. Signal Delay Reconstruction Metho d Based on Dynamic Index and Complex-Co efficient Lagrange Interp olation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yang,ZHENG Zhe; WU Siliang

    2015-01-01

    This paper presents a large-range, high-precision and continuously variable delay reconstruction method for wideband and arbitrary bandlimited signal, which combines dynamic index technique with complex-coefficient Lagrange interpolation technique. The method samples time-continuous bandlimited signal and stores samples in sequence. It manages to obtain the high-precision delay parameters of every sampling period from desired delay to compute the so-called index position variable and interpolator parameters. It dynamically in-dexes and chooses a set of samples to implement piecewise complex-coefficient Lagrange interpolation for reconstruct-ing the delayed sequences. The time-continuous delay re-construction signal can be simply accomplished through digital-to-analog conversion. The mathematical model of the method and its transformed form is given, and the arithmetic of dynamic index and complex-coefficient La-grange interpolation is derived. Simulation and test results show the validity and performance of the method.

  14. Achievement of Preassigned Spectra in the Synthesis of Band-Pass Constant-Envelope Signals by Rapidly Hopping through Discrete Frequencies

    CERN Document Server

    Callegari, Sergio

    2014-01-01

    Spread-spectrum signals are increasingly adopted in fields including communications, testing of electronic systems, Electro-Magnetic Compatibility (EMC) enhancement, ultrasonic non-destructive testing. This paper considers the synthesis of constant-envelope band-pass wave-forms with preassigned spectra via an FM technique using only a limited number of frequencies. In particular, an optimization-based approach for the selection of appropriate modulation parameters and statistical features of the modulating waveform is proposed. By example, it is shown that the design problem generally admits multiple local optima, but can still be managed with relative ease since the local optima can typically be scanned by changing the initial setting of a single parameter.

  15. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2016-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...

  16. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2014-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...

  17. Neurotensin receptor-1 inducible palmitoylation is required for efficient receptor-mediated mitogenic-signaling within structured membrane microdomains

    OpenAIRE

    2011-01-01

    Neurotensin receptor-1 (NTSR-1) is a G-protein coupled receptor (GPCR) that has been recently identified as a mediator of cancer progression. NTSR-1 and its endogenous ligand, neurotensin (NTS), are co-expressed in several breast cancer cell lines and breast cancer tumor samples. Based on our previously published study demonstrating that intact structured membrane microdomains (SMDs) are required for NTSR-1 mitogenic signaling, we hypothesized that regulated receptor palmitoylation is respons...

  18. Quantative Evaluation of the Efficiency of Facial Bio-potential Signals Based on Forehead Three-Channel Electrode Placement For Facial Gesture Recognition Applicable in a Human-Machine Interface

    Directory of Open Access Journals (Sweden)

    Iman Mohammad Rezazadeh

    2010-06-01

    Full Text Available Introduction: Today, facial bio-potential signals are employed in many human-machine interface applications for enhancing and empowering the rehabilitation process. The main point to achieve that goal is to record appropriate bioelectric signals from the human face by placing and configuring electrodes over it in the right way. In this paper, heuristic geometrical position and configuration of the electrodes has been proposed for improving the quality of the acquired signals and consequently enhancing the performance of the facial gesture classifier. Materials and Methods: Investigation and evaluation of the electrodes' proper geometrical position and configuration can be performed using two methods: clinical and modeling. In the clinical method, the electrodes are placed in predefined positions and the elicited signals from them are then processed. The performance of the method is evaluated based on the results obtained. On the other hand, in the modeling approach, the quality of the recorded signals and their information content are evaluated only by modeling and simulation. In this paper, both methods have been utilized together. First, suitable electrode positions and configuration were proposed and evaluated by modeling and simulation. Then, the experiment was performed with a predefined protocol on 7 healthy subjects to validate the simulation results. Here, the recorded signals were passed through parallel butterworth filter banks to obtain facial EMG, EOG and EEG signals and the RMS features of each 256 msec time slot were extracted.  By using the power of Subtractive Fuzzy C-Mean (SFCM, 8 different facial gestures (including smiling, frowning, pulling up left and right lip corners, left/right/up and down movements of the eyes were discriminated. Results: According to the three-channel electrode configuration derived from modeling of the dipoles effects on the surface electrodes and by employing the SFCM classifier, an average 94

  19. The role of the spray pyrolysed Al2O3 barrier layer in achieving high efficiency solar cells on flexible steel substrates

    Science.gov (United States)

    Gledhill, Sophie E.; Zykov, Anton; Rissom, Thorsten; Caballero, Raquel; Kaufmann, Christian A.; Fischer, Christian-Herbert; Lux-Steiner, Martha; Efimova, Varvara; Hoffmann, Volker; Oswald, Steffen

    2011-07-01

    Thin film chalcopyrite solar cells grown on light-weight, flexible steel substrates are poised to enter the photovoltaic market. To guarantee good solar cell performance, the diffusion of iron from the steel into the CIGSe absorber material must be hindered during layer deposition. A barrier layer is thus required to isolate the solar module from the metal substrate, both electronically and chemically. Ideally the barrier layer would be deposited by a cheap roll-to-roll process suitable to coat flexible steel substrates. Aluminium oxide deposited by spray pyrolysis matches the criteria. The coating is homogeneous over rough substrates allowing comparatively thin barrier layers to be utilized. In this article, solar cell results are presented contrasting the device performance made with a barrier layer to that without a barrier layer. Secondary Ion Mass spectrometry (SIMS) measurements show that the spray pyrolysed barrier layer diminishes iron diffusion to the chalcopyrite absorber layer. The role of sodium, imperative for the growth of high efficiency chalcopyrite solar cells, and how it interacts with Al2O3 is discussed.

  20. 巧用图表形象教学 创设历史高效课堂%Creating Efficient History Class with Diagrams to Achieve Vivid Teaching

    Institute of Scientific and Technical Information of China (English)

    马莉

    2011-01-01

    Historical illustration,as a visual teaching material,is a complement of the teaching materials.In this paper,illustrations resources from import new courses,to solve difficulties,summarize knowledge and expand knowledge,etc.to explore the use of illustrations,the image of teaching strategies to create historical efficient classroom,so as to improve teaching effectiveness.%历史插图作为一种直观教材,具有形象、生动、直观的特点,对历史教材中文字性的描述起到补充、解释的作用。本文利用插图资源从导入新课、解决难点、总结知识、拓展知识等方面,探究巧用插图形象教学的策略,以创设历史高效课堂,提高教学效果。

  1. Efficient reinforcement learning of a reservoir network model of parametric working memory achieved with a cluster population winner-take-all readout mechanism.

    Science.gov (United States)

    Cheng, Zhenbo; Deng, Zhidong; Hu, Xiaolin; Zhang, Bo; Yang, Tianming

    2015-12-01

    The brain often has to make decisions based on information stored in working memory, but the neural circuitry underlying working memory is not fully understood. Many theoretical efforts have been focused on modeling the persistent delay period activity in the prefrontal areas that is believed to represent working memory. Recent experiments reveal that the delay period activity in the prefrontal cortex is neither static nor homogeneous as previously assumed. Models based on reservoir networks have been proposed to model such a dynamical activity pattern. The connections between neurons within a reservoir are random and do not require explicit tuning. Information storage does not depend on the stable states of the network. However, it is not clear how the encoded information can be retrieved for decision making with a biologically realistic algorithm. We therefore built a reservoir-based neural network to model the neuronal responses of the prefrontal cortex in a somatosensory delayed discrimination task. We first illustrate that the neurons in the reservoir exhibit a heterogeneous and dynamical delay period activity observed in previous experiments. Then we show that a cluster population circuit decodes the information from the reservoir with a winner-take-all mechanism and contributes to the decision making. Finally, we show that the model achieves a good performance rapidly by shaping only the readout with reinforcement learning. Our model reproduces important features of previous behavior and neurophysiology data. We illustrate for the first time how task-specific information stored in a reservoir network can be retrieved with a biologically plausible reinforcement learning training scheme.

  2. Signaling Efficiency of the T Cell Receptor Controlled by a Single Amino Acid in the β Chain Constant Region

    OpenAIRE

    Bäckström, B Thomas; Hausmann, Barbara T.; Palmer, Ed

    1997-01-01

    A single amino acid residue, Gln136, located within the connecting peptide domain of Cβ controls the ability of the α/β TCR to transmit a full signal. TCRs in which this Cβ residue is mutated to Phe, the residue found in TCR-γ, are unresponsive to antigenic ligands. Interestingly, this Cβ residue is either polar or charged in every species studied thus far, including the trout and the skate. In contrast, the analogous residue in Cγ is always hydrophobic. In spite of their compromised antigen ...

  3. The Dipole Potential Modifies the Clustering and Ligand Binding Affinity of ErbB Proteins and Their Signaling Efficiency

    Science.gov (United States)

    Kovács, Tamás; Batta, Gyula; Hajdu, Tímea; Szabó, Ágnes; Váradi, Tímea; Zákány, Florina; Csomós, István; Szöllősi, János; Nagy, Peter

    2016-01-01

    Although activation of the ErbB family of receptor tyrosine kinases (ErbB1-4) is driven by oligomerization mediated by intermolecular interactions between the extracellular, the kinase and the transmembrane domains, the transmembrane domain has been largely neglected in this regard. The largest contributor to the intramembrane electric field, the dipole potential, alters the conformation of transmembrane peptides, but its effect on ErbB proteins is unknown. Here, we show by Förster resonance energy transfer (FRET) and number and brightness (N&B) experiments that the epidermal growth factor (EGF)-induced increase in the homoassociation of ErbB1 and ErbB2 and their heteroassociation are augmented by increasing the dipole potential. These effects were even more pronounced for ErbB2 harboring an activating Val → Glu mutation in the transmembrane domain (NeuT). The signaling capacity of ErbB1 and ErbB2 was also correlated with the dipole potential. Since the dipole potential decreased the affinity of EGF to ErbB1, the augmented growth factor-induced effects at an elevated dipole potential were actually induced at lower receptor occupancy. We conclude that the dipole potential plays a permissive role in the clustering of ErbB receptors and that the effects of lipid rafts on ligand binding and receptor signaling can be partially attributed to the dipole potential. PMID:27775011

  4. Jarid2 Coordinates Nanog Expression and PCP/Wnt Signaling Required for Efficient ESC Differentiation and Early Embryo Development

    Directory of Open Access Journals (Sweden)

    David Landeira

    2015-07-01

    Full Text Available Jarid2 is part of the Polycomb Repressor complex 2 (PRC2 responsible for genome-wide H3K27me3 deposition. Unlike other PRC2-deficient embryonic stem cells (ESCs, however, Jarid2-deficient ESCs show a severe differentiation block, altered colony morphology, and distinctive patterns of deregulated gene expression. Here, we show that Jarid2−/− ESCs express constitutively high levels of Nanog but reduced PCP signaling components Wnt9a, Prickle1, and Fzd2 and lowered β-catenin activity. Depletion of Wnt9a/Prickle1/Fzd2 from wild-type ESCs or overexpression of Nanog largely phenocopies these cellular defects. Co-culture of Jarid2−/− with wild-type ESCs restores variable Nanog expression and β-catenin activity and can partially rescue the differentiation block of mutant cells. In addition, we show that ESCs lacking Jarid2 or Wnt9a/Prickle1/Fzd2 or overexpressing Nanog induce multiple ICM formation when injected into normal E3.5 blastocysts. These data describe a previously unrecognized role for Jarid2 in regulating a core pluripotency and Wnt/PCP signaling circuit that is important for ESC differentiation and for pre-implantation development.

  5. Recent development in thermally activated desalination methods: achieving an energy efficiency less than 2.5 kWhelec/m3

    KAUST Repository

    Shahzad, Muhammad Wakil

    2015-05-19

    Water-Energy-Environment nexus is a crucial consideration when designing seawater desalination processes, particularly for the water-stressed countries where the annual water availability is less than 250 m3 per capita. Despite the thermodynamics limit for seawater desalination at normal conditions is about 0.78 to 1.09 kWhelec/m3, the specific energy consumption of desalination of real plants is found to operate at several folds higher. Today’s technological advancement in membranes, namely the reverse osmosis processes, has set an energy consumption of around 3.5–5 kWhelec/m3, while the conventional perception of thermally activated processes such as MSF and MED tends to be higher. Although the higher energetic specific consumption of MED or MSF processes appeared to be higher at 60–100 kWhthermal/m3, their true electricity equivalent has been converted, hitherto, using the energetic analyses where the work potential of working steam of the processes cannot be captured adequately. Thermally activated processes, such as MED and MSF, form the bottoming cycle of a cogeneration plant where both electricity and desalination processes operate in tandem in a cascaded manner. Only the bled-steam at lower exergy is extracted for the desalination processes. In this presentation, we demonstrate that in a cogen plant with 30% bled-steam for MED processes, the exergy destruction ratio is found to be less than 7% of the total available exergy that emanated from the boilers. By the exergetic approach, the equivalent electricity consumption of an average 75 kWhthermal/m3 would result in an electrical equivalent of less than 2.5 kWhelec/m3. Also in this presentation, the authors will elaborate the latest developments in the use of hybridization concept where the MED and the AD cycles are thermodynamically integrated and enhancing the overall efficiency of desalination. © 2015 Balaban Desalination Publications

  6. Simple and efficient methods to generate split roots and grafted plants useful for long-distance signaling studies in Medicago truncatula and other small plants

    Directory of Open Access Journals (Sweden)

    Kassaw Tessema K

    2012-09-01

    Full Text Available Abstract Background Long distance signaling is a common phenomenon in animal and plant development. In plants, lateral organs such as nodules and lateral roots are developmentally regulated by root-to-shoot and shoot-to-root long distance signaling. Grafting and split root experiments have been used in the past to study the systemic long distance effect of endogenous and environmental factors, however the potential of these techniques has not been fully realized because data replicates are often limited due to cumbersome and difficult approaches and many plant species with soft tissue are difficult to work with. Hence, developing simple and efficient methods for grafting and split root inoculation in these plants is of great importance. Results We report a split root inoculation system for the small legume M. truncatula as well as robust and reliable techniques of inverted-Y grafting and reciprocal grafting. Although the split root technique has been historically used for a variety of experimental purposes, we made it simple, efficient and reproducible for M. truncatula. Using our split root experiments, we showed the systemic long distance suppression of nodulation on a second wild type root inoculated after a delay, as well as the lack of this suppression in mutants defective in autoregulation. We demonstrated inverted-Y grafting as a method to generate plants having two different root genotypes. We confirmed that our grafting method does not affect the normal growth and development of the inserted root; the composite plants maintained normal root morphology and anatomy. Shoot-to-root reciprocal grafts were efficiently made with a modification of this technique and, like standard grafts, demonstrate that the regulatory signal defective in rdn1 mutants acts in the root. Conclusions Our split root inoculation protocol shows marked improvement over existing methods in the number and quality of the roots produced. The dual functions of the

  7. An efficient computational approach to characterize DSC-MRI signals arising from three-dimensional heterogeneous tissue structures.

    Science.gov (United States)

    Semmineh, Natenael B; Xu, Junzhong; Boxerman, Jerrold L; Delaney, Gary W; Cleary, Paul W; Gore, John C; Quarles, C Chad

    2014-01-01

    The systematic investigation of susceptibility-induced contrast in MRI is important to better interpret the influence of microvascular and microcellular morphology on DSC-MRI derived perfusion data. Recently, a novel computational approach called the Finite Perturber Method (FPM), which enables the study of susceptibility-induced contrast in MRI arising from arbitrary microvascular morphologies in 3D has been developed. However, the FPM has lower efficiency in simulating water diffusion especially for complex tissues. In this work, an improved computational approach that combines the FPM with a matrix-based finite difference method (FDM), which we call the Finite Perturber the Finite Difference Method (FPFDM), has been developed in order to efficiently investigate the influence of vascular and extravascular morphological features on susceptibility-induced transverse relaxation. The current work provides a framework for better interpreting how DSC-MRI data depend on various phenomena, including contrast agent leakage in cancerous tissues and water diffusion rates. In addition, we illustrate using simulated and micro-CT extracted tissue structures the improved FPFDM along with its potential applications and limitations.

  8. An efficient VLSI implementation of on-line recursive ICA processor for real-time multi-channel EEG signal separation.

    Science.gov (United States)

    Shih, Wei-Yeh; Liao, Jui-Chieh; Huang, Kuan-Ju; Fang, Wai-Chi; Cauwenberghs, Gert; Jung, Tzyy-Ping

    2013-01-01

    This paper presents an efficient VLSI implementation of on-line recursive ICA (ORICA) processor for real-time multi-channel EEG signal separation. The proposed design contains a system control unit, a whitening unit, a singular value decomposition unit, a floating matrix multiply unit and, and an ORICA weight training unit. Because the input sample rate of the ORICA processor is 128 Hz, the ORICA processor should produce independent components before the next sample is input in 1/128 s. Under the timing constraints of commutating multi-channel ORICA in real time, the design of the ORICA processor is a mixed architecture, which is designed as different hardware parallelism according to the complexity of processing units. The shared arithmetic processing unit and shared register can reduce hardware complexity and power consumption. The proposed design is implemented used TSMC 90 nm CMOS technology with 8-channel EEG processing in 128 Hz sample rate of raw data and consumes 2.827 mW at 50 MHz clock rate. The performance of the proposed design is also shown to reach 0.0078125 s latency after each EEG sample time, and the average correlation coefficient between the original source signals and extracted ORICA signals for each 1 s frame is 0.9763.

  9. A stilbene synthase allele from a Chinese wild grapevine confers resistance to powdery mildew by recruiting salicylic acid signalling for efficient defence

    Science.gov (United States)

    Jiao, Yuntong; Xu, Weirong; Duan, Dong; Wang, Yuejin; Nick, Peter

    2016-01-01

    Stilbenes are central phytoalexins in Vitis, and induction of the key enzyme stilbene synthase (STS) is pivotal for disease resistance. Here, we address the potential for breeding resistance using an STS allele isolated from Chinese wild grapevine Vitis pseudoreticulata (VpSTS) by comparison with its homologue from Vitis vinifera cv. ‘Carigane’ (VvSTS). Although the coding regions of both alleles are very similar (>99% identity on the amino acid level), the promoter regions are significantly different. By expression in Arabidopsis as a heterologous system, we show that the allele from the wild Chinese grapevine can confer accumulation of stilbenes and resistance against the powdery mildew Golovinomyces cichoracearum, whereas the allele from the vinifera cultivar cannot. To dissect the upstream signalling driving the activation of this promoter, we used a dual-luciferase reporter system in a grapevine cell culture. We show elevated responsiveness of the promoter from the wild grape to salicylic acid (SA) and to the pathogen-associated molecular pattern (PAMP) flg22, equal induction of both alleles by jasmonic acid (JA), and a lack of response to the cell death-inducing elicitor Harpin. This elevated SA response of the VpSTS promoter depends on calcium influx, oxidative burst by RboH, mitogen-activated protein kinase (MAPK) signalling, and JA synthesis. We integrate the data in the context of a model where the resistance of V. pseudoreticulata is linked to a more efficient recruitment of SA signalling for phytoalexin synthesis. PMID:27702992

  10. Chemical signals and their regulations on the plant growth and water use efficiency of cotton seedlings under partial root-zone drying and different nitrogen applications

    Directory of Open Access Journals (Sweden)

    Wenrao Li

    2017-03-01

    Full Text Available Partial root-zone drying during irrigation (PRD has been shown effective in enhancing plant water use efficiency (WUE, however, the roles of chemical signals from root and shoot that are involved and the possible interactions affected by nitrogen nutrition are not clear. Pot-grown cotton (Gossypium spp. seedlings were treated with three levels of N fertilization and PRD. The concentrations of nitrate (NO3−, abscisic acid (ABA and the pH value of leaf and root xylem saps, biomass and WUE were measured. Results showed that PRD plants produced larger biomass and higher WUE than non-PRD plants, with significant changes in leaf xylem ABA, leaf and root xylem NO3− concentrations and pH values, under heterogeneous soil moisture conditions. Simultaneously, high-N treated plants displayed larger changes in leaf xylem ABA and higher root xylem NO3− concentrations, than in the medium- or low-N treated plants. However, the WUE of plants in the low-N treatment was higher than that of those in the high- and medium-N treatments. PRD and nitrogen levels respectively induced signaling responses of ABA/NO3− and pH in leaf or root xylem to affect WUE and biomass under different watering levels, although significant interactions of PRD and nitrogen levels were found when these signal molecules responded to soil drying. We conclude that these signaling chemicals are regulated by interaction of PRD and nitrogen status to regulate stomatal behavior, either directly or indirectly, and thus increase PRD plant WUE under less irrigation.

  11. The Sensitive Infrared Signal Detection by Sum Frequency Generation

    Science.gov (United States)

    Wong, Teh-Hwa; Yu, Jirong; Bai, Yingxin

    2013-01-01

    An up-conversion device that converts 2.05-micron light to 700 nm signal by sum frequency generation using a periodically poled lithium niobate crystal is demonstrated. The achieved 92% up-conversion efficiency paves the path to detect extremely weak 2.05-micron signal with well established silicon avalanche photodiode detector for sensitive lidar applications.

  12. Charge transfer efficiency measurements at low signal levels on STIS/SOHO TK1024 CCD's. [Space Telescope Imaging Spectrograph / Solar Heliocentric Observatory

    Science.gov (United States)

    Orbock, J. D.; Murata-Seawalt, D.; Delamere, W. A.; Blouke, Morley M.

    1990-01-01

    Charge transfer efficiency (CTE) test methods are reviewed, and the results and conclusions of the tests are given. The test methods have been utilized to describe the CTE characteristics of the Tektronix 1024 by 1024 CCD to optimize low dark current, low readout noise, and high CTE at low signal levels. CTE modelling is described, and three test methods are set forth and compared. The Fe-55 X-ray response method utilizes the response of a CCD to X-ray photons from the radioactive source Fe-55. The extended pixel edge response method employs the measurement of the charge lost to successive pixels by a known initial signal as it is shifted through the array. The charge injection method consists of charge injection through the output amplifier reset transistor. These measurements were performed on several devices with known CTEs. The CTEs are found to be in agreement for the three methods, making application and test requirements the principal criteria for their use.

  13. Efficient and Robust Signal Approximations

    Science.gov (United States)

    2009-05-01

    frustration, impatience, procrastination , despair) await for the weak to slip into their traps. I am deeply grateful to my advisor Mike Lewicki for inspiring...image representation, which overcomes the artifi- cial block confinement and computational obstacles. Our method consists of a preliminary MR (e.g...subband. However, by applying a variant of our method called modified MrICA we can overcome this obstacle. Namely, we impose that for all subbands up to

  14. A gene delivery system containing nuclear localization signal: Increased nucleus import and transfection efficiency with the assistance of RanGAP1.

    Science.gov (United States)

    Chen, Kang; Guo, Lingling; Zhang, Jiulong; Chen, Qing; Wang, Kuanglei; Li, Chenxi; Li, Weinan; Qiao, Mingxi; Zhao, Xiuli; Hu, Haiyang; Chen, Dawei

    2017-01-15

    In the present report, a degradable gene delivery system (PAMS/DNA/10NLS) containing nucleus location signal peptide (NLS) was prepared. The agarose gel electrophoresis, particle size and zeta potential of PAMS/DNA/10NLS were similar to those of PAMS/DNA, which proved that NLS did not affect the interaction between PAMS and DNA. PAMS/DNA/10NLS exhibited marked extracellular and intracellular degradation under acidic conditions. The degradation was believed to allow NLS to come into contact with importins easily, which was able to mediate the nucleus import. With the help of NLS, PAMS/DNA/10NLS exhibited a higher transfection capability than PAMS/DNA. Moreover, the transfection of PAMS/DNA/10NLS was less dependent on the breakdown of the nucleus envelope than PAMS/DNA. Considering that GTPase-activating protein 1 (RanGAP1) was able to activate the endogenous GTPase, which was necessary for NLS-mediated nucleus import, RanGAP1 overexpressed cells (RanGAP1 cells) were produced. This result showed that RanGAP1 cells had higher GTPase activities than normal cells. Both the nucleus import and transfection efficiency of PAMS/DNA/10NLS were markedly higher in RanGAP1 cells than that in normal cells. The in vivo transfection results also showed that the transfection efficiency of PAMS/DNA/10NLS was higher in RanGAP1 pre-treated mice than that in normal mice. These findings showed that PAMS/DNA/10NLS is a promising gene delivery system with the assistance of RanGAP1.

  15. The meganuclease I-SceI containing nuclear localization signal (NLS-I-SceI efficiently mediated mammalian germline transgenesis via embryo cytoplasmic microinjection.

    Directory of Open Access Journals (Sweden)

    Yong Wang

    Full Text Available The meganuclease I-SceI has been effectively used to facilitate transgenesis in fish eggs for nearly a decade. I-SceI-mediated transgenesis is simply via embryo cytoplasmic microinjection and only involves plasmid vectors containing I-SceI recognition sequences, therefore regarding the transgenesis process and application of resulted transgenic organisms, I-SceI-mediated transgenesis is of minimal bio-safety concerns. However, currently no transgenic mammals derived from I-SceI-mediated transgenesis have been reported. In this work, we found that the native I-SceI molecule was not capable of facilitating transgenesis in mammalian embryos via cytoplasmic microinjection as it did in fish eggs. In contrast, the I-SceI molecule containing mammalian nuclear localization signal (NLS-I-SceI was shown to be capable of transferring DNA fragments from cytoplasm into nuclear in porcine embryos, and cytoplasmic microinjection with NLS-I-SceI mRNA and circular I-SceI recognition sequence-containing transgene plasmids resulted in transgene expression in both mouse and porcine embryos. Besides, transfer of the cytoplasmically microinjected mouse and porcine embryos into synchronized recipient females both efficiently resulted in transgenic founders with germline transmission competence. These results provided a novel method to facilitate mammalian transgenesis using I-SceI, and using the NLS-I-SceI molecule, a simple, efficient and species-neutral transgenesis technology based on embryo cytoplasmic microinjection with minimal bio-safety concerns can be established for mammalian species. As far as we know, this is the first report for transgenic mammals derived from I-SceI-mediated transgenesis via embryo cytoplasmic microinjection.

  16. The meganuclease I-SceI containing nuclear localization signal (NLS-I-SceI) efficiently mediated mammalian germline transgenesis via embryo cytoplasmic microinjection.

    Science.gov (United States)

    Wang, Yong; Zhou, Xiao-Yang; Xiang, Peng-Ying; Wang, Lu-Lu; Tang, Huan; Xie, Fei; Li, Liang; Wei, Hong

    2014-01-01

    The meganuclease I-SceI has been effectively used to facilitate transgenesis in fish eggs for nearly a decade. I-SceI-mediated transgenesis is simply via embryo cytoplasmic microinjection and only involves plasmid vectors containing I-SceI recognition sequences, therefore regarding the transgenesis process and application of resulted transgenic organisms, I-SceI-mediated transgenesis is of minimal bio-safety concerns. However, currently no transgenic mammals derived from I-SceI-mediated transgenesis have been reported. In this work, we found that the native I-SceI molecule was not capable of facilitating transgenesis in mammalian embryos via cytoplasmic microinjection as it did in fish eggs. In contrast, the I-SceI molecule containing mammalian nuclear localization signal (NLS-I-SceI) was shown to be capable of transferring DNA fragments from cytoplasm into nuclear in porcine embryos, and cytoplasmic microinjection with NLS-I-SceI mRNA and circular I-SceI recognition sequence-containing transgene plasmids resulted in transgene expression in both mouse and porcine embryos. Besides, transfer of the cytoplasmically microinjected mouse and porcine embryos into synchronized recipient females both efficiently resulted in transgenic founders with germline transmission competence. These results provided a novel method to facilitate mammalian transgenesis using I-SceI, and using the NLS-I-SceI molecule, a simple, efficient and species-neutral transgenesis technology based on embryo cytoplasmic microinjection with minimal bio-safety concerns can be established for mammalian species. As far as we know, this is the first report for transgenic mammals derived from I-SceI-mediated transgenesis via embryo cytoplasmic microinjection.

  17. Using Straight Light Hair to Achieve Interactive Signal Insertion of IPQAM Installation and Debugging%利用直调光发实现 IPQAM互动信号插播的安装与调试

    Institute of Scientific and Technical Information of China (English)

    刘圣奇

    2016-01-01

    在互动电视用户迅速增长的情况下,为了提高服务质量,利用1550 nm直调光发实现IPQAM互动信号的插播,既可平滑升级又可节约投资成本,有利于开展双向业务,同时可以不改变网络结构而升级系统,为今后开展FTTH业务打下基础,具有一定的实用价值。%Paper described has in wired digital interactive TV user growth quickly situation Xia , to guarantee interactive business of normal stable run , and improve service quality , I Taiwan using 1 550 nm straight ad-justable light sent achieved IPQAM interactive signal spots of installation and debugging of actual case , can smooth upgrade and can save investment cost , conducive to broadcasting carried out two -way business fast preemption market , while in user number increased Shi , can in not change network structure Xia upgrade sys-tem, also for future GPON carried out FTTH business laying , Has practical value , for reference.

  18. 耕地集约经营与实现土地使用效益最大化探究%Take the Road of Intensive Arable Land to Achieve Maximum Efficiency of Land Use

    Institute of Scientific and Technical Information of China (English)

    张玖霞; 方杰

    2011-01-01

    In this paper,Meihekou scale intensive arable land to achieve good results as the starting point,the transfer of land from the government guidance to promote,develop policies to create conditions for the scale,speed up the transfer of rural labor to expand the scale of operation in space in the analysis of Meihekou scale intensive arable land on the remarkable results.Meanwhile,for the land transfer process Meihekou exist in many non-standard issues,from land to carry out intensive,in order to achieve maximum efficiency of land use perspective,on how to do large-scale land operation Meihekou proposed measures.%本文以梅河口市做好耕地集约规模经营取得的成效为切入点,从政府引导推动土地流转,制定优惠扶持政策为规模经营创造条件,加快农村劳动力转移为规模经营拓展空间等方面分析了梅河口市在耕地集约规模经营上取得的显著成效。同时,针对梅河口市在土地流转过程中存在的问题,从实现土地使用效益最大化的视角,对梅河口市如何做好土地规模经营提出了相关的对策。

  19. Effects of Root Pruning on Non-Hydraulic Root-Sourced Signal, Drought Tolerance and Water Use Efficiency of Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    MA Shou-chen; LI Feng-min; YANG Shen-jiao; LI Chun-xi; XU Bing-cheng; ZHANG Xu-cheng

    2013-01-01

    Two pot experiments were conducted to study the effects of root pruning at the stem elongation stage on non-hydraulic root-sourced signals (nHRS), drought tolerance and water use efficiency of winter wheat (Triticum aestivum). The root pruning significantly reduced the root weight of wheat, but had no effect on root/shoot ratio at the two tested stages. At booting stage, specific root respiration of root pruned plants was significantly higher than those with intact roots (1.06 and 0.94 mmol g-1 s-1, respectively). The soil water content (SWC) at which nHRS for root pruned plants appeared was higher and terminated lower than for intact root plants, the threshold range of nHRS was markedly greater for root pruned plants (61.1-44.6%field water capacity) than for intact root plants (57.9-46.1%field water capacity). At flowering stage, while there was no significant difference in specific root respiration. The SWCs at which nHRS appeared and terminated were both higher for root pruned plants than for intact root plants. The values of chlorophyll fluorescence parameters, i.e., the effective photosystem II quantum yield ( PS I ), the maximum photochemical efficiency of PS II (Fv/Fm), coefficient of photochemical quenching (qP), and coefficient of non-photochemical quenching (NPQ), in root pruned plants were significantly higher than in intact root plants, 7 d after withholding of water. Root pruned plants had significantly higher water use efficiency (WUE) than intact root plants in well-watered and medium drought soil, but not in severe drought condition. In addition, root pruning had no significant effect on grain yield in well-watered and medium drought soil, but significantly decreased grain yield in severe drought condition. In conclusion, the current study showed that root pruning significantly altered nHRS sensitivity and improved WUE of winter wheat in well-watered and medium drought soil, but lowered drought tolerance of winter wheat in severe drought soil. This

  20. Effect of the AlPO4 join on the pump-to-signal conversion efficiency in heavily Er-doped fibers.

    Science.gov (United States)

    Likhachev, Mikhail E; Bubnov, Mikhail M; Zotov, Kirill V; Lipatov, Denis S; Yashkov, Mikhail V; Guryanov, Aleksei N

    2009-11-01

    Heavily Er-doped fibers (EDFs) based on P(2)O(5)-Al(2)O(3)-SiO(2) (PAS) ternary glass have been studied. A unique feature of this glass is the formation of a AlPO(4) join having a structure similar to that of SiO(2) glass and a refractive index below it. It is found that the Er(3+) absorption and emission spectra in the PAS EDFs are defined by the dopant (Al(2)O(3) or P(2)O(5)) present in excess and are close to those of the corresponding binary glass (Al(2)O(3)-SiO(2) or P(2)O(5)-SiO(2)). The presence of the AlPO(4) join results in the enhancement of the pump-to-signal conversion efficiency in the PAS EDFs as compared with the EDFs based on the P(2)O(5)-SiO(2) and Al(2)O(3)-SiO(2) (with 1.5 mol. %Al(2)O(3) and less) binary glasses. The PAS host glass is advantageous in the case of large-mode-area active fibers.

  1. Efficient hammerhead ribozyme-mediated cleavage of the structured hepatitis B virus encapsidation signal in vitro and in cell extracts, but not in intact cells.

    Science.gov (United States)

    Beck, J; Nassal, M

    1995-01-01

    Hepatitis B virus (HBV), the causative agent of B-type hepatitis in man, is a small enveloped DNA virus that replicates through reverse transcription of an RNA intermediate, the terminally redundant RNA pregenome. An essential highly conserved cis-element present twice on this RNA is the encapsidation signal epsilon, a stem-loop structure that is critical for pregenome packaging and reverse transcription. Epsilon is hence an attractive target for antiviral therapy. Its structure, however, is a potential obstacle to antivirals whose action depends on hybridization, e.g. ribozymes. Here we demonstrate effective in vitro cleavage inside epsilon by hammerhead ribozymes containing flanking sequences complementary to an adjacent less structured region. Upon co-transfection with a HBV expression construct corresponding ribozymes embedded in a U6 snRNA context led to a significant, though modest, reduction in the steady-state level of HBV pregenomes. Inactive ribozyme mutants revealed that antisense effects contributed substantially to this reduction, however, efficient epsilon cleavage by the intracellularly expressed ribozymes was observed in Mg(2+)-supplemented cell lysates. Artificial HBV pregenomes carrying the ribozymes in cis and model RNAs lacking all HBV sequences except epsilon exhibited essentially the same behaviour. Hence, neither the absence of co-localization of ribozyme and target nor a viral component, but rather a cellular factor(s), is responsible for the strikingly different ribozyme activities inside cells and in cellular extracts. Images PMID:8559651

  2. 高效率量子点中间带太阳电池的构建与实现%Construction and Achievement of High Efficient Quantum Dot Intermediate Band Solar Cells

    Institute of Scientific and Technical Information of China (English)

    彭英才; 王峰; 江子荣; 马蕾; 蒋冰; 陈乙豪

    2012-01-01

    中间带太阳电池是为了充分利用太阳光谱中的红外光子能量而提出的一种高效率新概念太阳电池.介绍了中间带太阳电池的能量上转换原理、量子点中间带的物理优势、量子点中间带太阳电池的结构组态和理论转换效率.评述了它的近期研究进展,并提出了发展这种新概念太阳电池的若干技术对策,其中包括补偿量子点的积累应变、优化量子点的生长参数和选择新的量子点结构.最后指出,由于应变的补偿,有序量子点层的形成以及新量子点结构的采用使太阳电池的光伏性能得以有效改善.可以预期,具有高转换效率的量子点中间带太阳电池的构建与实现将会对未来的光伏技术与产业带来革命性的影响.%In order to fully utilize the infrared photon energy in the solar radiation spectrum, the intermediate band solar cell as a efficient new concept solar cell is proposed. The energy up-cover-sion principles of the intermediate band solar cell, physics feature of the quantum dot intermediate band, configurations of the quantum dot intermediat band solar cell and its theoretical conversion efficiency are introduced. Its recent developments are also reviewed, and some technical strategies are suggested, including the compensation for the accumulation strains of quantum dots, optimization of the growth parameters and selection of the new quantum dot structures. The results indicate that because of the compensation of strains, formation of ordering quantum dot layers and employment of new quantum dot structures, the photovoltaic performance of solar cells can be significantlly improved. It can be expected that the construction and achievement of quantum dot intermediate band solar cells with high conversion efficiency and low cost will bring a revolutionary effect on the future photovoltaic technology and industry.

  3. Interactive Digital Signal Processor

    Science.gov (United States)

    Mish, W. H.

    1985-01-01

    Interactive Digital Signal Processor, IDSP, consists of set of time series analysis "operators" based on various algorithms commonly used for digital signal analysis. Processing of digital signal time series to extract information usually achieved by applications of number of fairly standard operations. IDSP excellent teaching tool for demonstrating application for time series operators to artificially generated signals.

  4. 光子晶体光纤中高效的反斯托克斯信号产生%High efficient anti-Stokes signal conversion in photonic crystal fiber

    Institute of Scientific and Technical Information of China (English)

    申向伟; 余重秀; 桑新柱; 苑金辉; 韩颖; 夏长明; 侯蓝田; 饶芬; 夏民; 尹霄丽

    2012-01-01

    基于四波混频的反斯托克斯变换,被广泛应用于短波辐射高分辨率成像以及直接激发分子的电子跃迁等方面.为了实现更加高效的反斯托克斯变换,利用中心波长为810 nm脉冲宽度为120 fs的钛蓝宝石(Ti:sapphire)飞秒激光器作为抽运光源,在长度为0.5 m和3 m的光子晶体光纤中分别实现了高阶模和基膜的简并四波混频.实验中,采用的光子晶体光纤的零色散波长在820 nm附近.在基模相位匹配条件下,在560 nm附近实现了高效地反斯托克斯信号的产生,反斯托克斯信号与残余抽运信号的最大功率比为33:1;反斯托克斯信号和斯托克斯信号的最大功率比25:1;反斯托克斯信号最大功率转换效率P_a/P_(p0)为34%.抽运波长从790 nm逐渐增加到810 nm过程中,在长为3 m的光子晶体光纤中相位从不匹配状态转化为高阶模匹配状态后,再转化为基模匹配状态.通过实验研究得出了相位匹配程度随抽运功率、波长和光纤长度的变化规律,同时分析了造成理论计算与实验结果存在差异的主要因素.本文为研究在光子晶体光纤基模中实现相位匹配和产生高效反斯托克斯信号提供了理论和实验依据.%The anti-Stokes frequency conversion based on four-wave mixing(FWM) has been widely used to generate short-wavelength radiation for high resolution imaging,direct excitation of electronic molecular transitions,and so on.For achieving more effective anti- Stokes conversion,we use the Ti:sapphire laser with a central wavelength of 810 nm and a pulse width of 120 fs as a pump source,and the degenerated FWMs of the higher mode and the fundamental mode are achieved respectively in 0.5 m long and 3 m long photonic crystal fibers(PCFs) with a zero dispersion wavelength of fundamental mode around 820nm in our experiment.The anti-Stokes signals around 560nm are generated efficiently at the fundamental phase matching.The maximum

  5. Development of an efficient signal amplification strategy for label-free enzyme immunoassay using two site-specific biotinylated recombinant proteins.

    Science.gov (United States)

    Tang, Jin-Bao; Tang, Ying; Yang, Hong-Ming

    2015-02-15

    Constructing a recombinant protein between a reporter enzyme and a detector protein to produce a homogeneous immunological reagent is advantageous over random chemical conjugation. However, the approach hardly recombines multiple enzymes in a difunctional fusion protein, which results in insufficient amplification of the enzymatic signal, thereby limiting its application in further enhancement of analytical signal. In this study, two site-specific biotinylated recombinant proteins, namely, divalent biotinylated alkaline phosphatase (AP) and monovalent biotinylated ZZ domain, were produced by employing the Avitag-BirA system. Through the high streptavidin (SA)-biotin interaction, the divalent biotinylated APs were clustered in the SA-biotin complex and then incorporated with the biotinylated ZZ. This incorporation results in the formation of a functional macromolecule that involves numerous APs, thereby enhancing the enzymatic signal, and in the production of several ZZ molecules for the interaction with immunoglobulin G (IgG) antibody. The advantage of this signal amplification strategy is demonstrated through ELISA, in which the analytical signal was substantially enhanced, with a 32-fold increase in the detection sensitivity compared with the ZZ-AP fusion protein approach. The proposed immunoassay without chemical modification can be an alternative strategy to enhance the analytical signals in various applications involving immunosensors and diagnostic chips, given that the label-free IgG antibody is suitable for the ZZ protein.

  6. MRA Based Efficient Database Storing and Fast Querying Technique

    Directory of Open Access Journals (Sweden)

    Mitko Kostov

    2017-02-01

    Full Text Available In this paper we consider a specific way of organizing 1D signals or 2D image databases, such that a more efficient storage and faster querying is achieved. A multiresolution technique of data processing is used in order of saving the most significant processed data.

  7. The role of lipoprotein processing by signal peptidase II in the Gram-positive eubacterium Bacillus subtilis : Signal peptidase II is required for the efficient secretion of alpha-amylase, a non-lipoprotein

    NARCIS (Netherlands)

    Tjalsma, H; Kontinen, VP; Pragai, Z; Meima, R; Venema, G; Bron, S; Sarvas, M; van Dijl, JM

    1999-01-01

    Computer-assisted analyses indicate that Bacillus subtilis contains approximately 300 genes for exported proteins with an amino-terminal signal peptide. About 114 of these are lipoproteins, which are retained in the cytoplasmic membrane. We have investigated the importance of lipoprotein processing

  8. Spectrally and Energy Efficient OFDM (SEE-OFDM) for Intensity Modulated Optical Wireless Systems

    OpenAIRE

    Lam, Emily; Wilson, Sarah Kate; Elgala, Hany; Little, Thomas D. C.

    2015-01-01

    Spectrally and energy efficient orthogonal frequency division multiplexing (SEE-OFDM) is an optical OFDM technique based on combining multiple asymmetrically clipped optical OFDM (ACO-OFDM) signals into one OFDM signal. By summing different components together, SEE-OFDM can achieve the same spectral efficiency as DC-biased optical OFDM (DCO-OFDM) without an energy-inefficient DC-bias. This paper introduces multiple methods for decoding a SEE-OFDM symbol and shows that an iterative decoder wit...

  9. Real-time Nyquist signaling with dynamic precision and flexible non-integer oversampling.

    Science.gov (United States)

    Schmogrow, R; Meyer, M; Schindler, P C; Nebendahl, B; Dreschmann, M; Meyer, J; Josten, A; Hillerkuss, D; Ben-Ezra, S; Becker, J; Koos, C; Freude, W; Leuthold, J

    2014-01-13

    We demonstrate two efficient processing techniques for Nyquist signals, namely computation of signals using dynamic precision as well as arbitrary rational oversampling factors. With these techniques along with massively parallel processing it becomes possible to generate and receive high data rate Nyquist signals with flexible symbol rates and bandwidths, a feature which is highly desirable for novel flexgrid networks. We achieved maximum bit rates of 252 Gbit/s in real-time.

  10. Achieving Mobile Office and Mobile Health by Adopting VPN Technology and Using Operator's Signal%采用VPN技术和利用运营商信号实现移动办公和移动医疗

    Institute of Scientific and Technical Information of China (English)

    牛瑛

    2014-01-01

    The development of information technology, as wel as the mature of application of 3G network and smartphone technology have created a good environment and development space for the application of mobile data service. Zhongshan people's hospital has realized mobile of ice and mobile health by adopting VPN technology, using the signal provided by network operator. It is the author's opinion that, the cost of establishing hospital's own WLAN is too high, and system maintenance can be cumbersome;by contrast, using operator's wireless signals can be more convenient and low-cost, maintenance of system can also be carried out by operators. After testing, microwave therapeutic instrument interferes with Wi-Fi signals, while 3G signals can operate normal y under same circumstances.%中山市人民医院通过采用VPN技术和利用运营商信号实现了移动办公和移动医疗。作者认为,医院自己架设无线局域网成本高,维护麻烦,利用运营商的无线信号比较方便,成本便宜,维护工作可由运营商承担。经过测试,微波治疗仪对Wi-Fi信号有干扰,而3G信号可以正常使用。

  11. Leader as achiever.

    Science.gov (United States)

    Dienemann, Jacqueline

    2002-01-01

    This article examines one outcome of leadership: productive achievement. Without achievement one is judged to not truly be a leader. Thus, the ideal leader must be a visionary, a critical thinker, an expert, a communicator, a mentor, and an achiever of organizational goals. This article explores the organizational context that supports achievement, measures of quality nursing care, fiscal accountability, leadership development, rewards and punishments, and the educational content and teaching strategies to prepare graduates to be achievers.

  12. 关注国有银行与股份制银行的绩效差异%Paying Close Attention to the Difference of Achievement and Efficiency between State-run Bank and Shareholding Bank

    Institute of Scientific and Technical Information of China (English)

    万颖群

    2004-01-01

    Seen from kinds of statistical data, state-run bank and shareholding bank differ in greatly in capital efficiency and harmful assets rate, management effect of shareholding bank are higher than four state-run banks, This article analyses originally main factors affecting dfficiency of commercial bank, such as enterprise administration stucture, put foward lots of valuable opinions.

  13. Evaluation of the efficiency of continuous wavelet transform as processing and preprocessing algorithm for resolution of overlapped signals in univariate and multivariate regression analyses; an application to ternary and quaternary mixtures.

    Science.gov (United States)

    Hegazy, Maha A; Lotfy, Hayam M; Mowaka, Shereen; Mohamed, Ekram Hany

    2016-07-05

    Wavelets have been adapted for a vast number of signal-processing applications due to the amount of information that can be extracted from a signal. In this work, a comparative study on the efficiency of continuous wavelet transform (CWT) as a signal processing tool in univariate regression and a pre-processing tool in multivariate analysis using partial least square (CWT-PLS) was conducted. These were applied to complex spectral signals of ternary and quaternary mixtures. CWT-PLS method succeeded in the simultaneous determination of a quaternary mixture of drotaverine (DRO), caffeine (CAF), paracetamol (PAR) and p-aminophenol (PAP, the major impurity of paracetamol). While, the univariate CWT failed to simultaneously determine the quaternary mixture components and was able to determine only PAR and PAP, the ternary mixtures of DRO, CAF, and PAR and CAF, PAR, and PAP. During the calculations of CWT, different wavelet families were tested. The univariate CWT method was validated according to the ICH guidelines. While for the development of the CWT-PLS model a calibration set was prepared by means of an orthogonal experimental design and their absorption spectra were recorded and processed by CWT. The CWT-PLS model was constructed by regression between the wavelet coefficients and concentration matrices and validation was performed by both cross validation and external validation sets. Both methods were successfully applied for determination of the studied drugs in pharmaceutical formulations.

  14. Evaluation of the efficiency of continuous wavelet transform as processing and preprocessing algorithm for resolution of overlapped signals in univariate and multivariate regression analyses; an application to ternary and quaternary mixtures

    Science.gov (United States)

    Hegazy, Maha A.; Lotfy, Hayam M.; Mowaka, Shereen; Mohamed, Ekram Hany

    2016-07-01

    Wavelets have been adapted for a vast number of signal-processing applications due to the amount of information that can be extracted from a signal. In this work, a comparative study on the efficiency of continuous wavelet transform (CWT) as a signal processing tool in univariate regression and a pre-processing tool in multivariate analysis using partial least square (CWT-PLS) was conducted. These were applied to complex spectral signals of ternary and quaternary mixtures. CWT-PLS method succeeded in the simultaneous determination of a quaternary mixture of drotaverine (DRO), caffeine (CAF), paracetamol (PAR) and p-aminophenol (PAP, the major impurity of paracetamol). While, the univariate CWT failed to simultaneously determine the quaternary mixture components and was able to determine only PAR and PAP, the ternary mixtures of DRO, CAF, and PAR and CAF, PAR, and PAP. During the calculations of CWT, different wavelet families were tested. The univariate CWT method was validated according to the ICH guidelines. While for the development of the CWT-PLS model a calibration set was prepared by means of an orthogonal experimental design and their absorption spectra were recorded and processed by CWT. The CWT-PLS model was constructed by regression between the wavelet coefficients and concentration matrices and validation was performed by both cross validation and external validation sets. Both methods were successfully applied for determination of the studied drugs in pharmaceutical formulations.

  15. G Protein-Dependent CCR5 Signaling Is Not Required for Efficient Infection of Primary T Lymphocytes and Macrophages by R5 Human Immunodeficiency Virus Type 1 Isolates

    OpenAIRE

    2003-01-01

    The requirement of human immunodeficiency virus (HIV)-induced CCR5 activation for infection by R5 HIV type 1 (HIV-1) strains remains controversial. Ectopic CCR5 expression in CD4+-transformed cells or pharmacological inhibition of Gαi proteins coupled to CCR5 left unsolved whether CCR5-dependent cell activation is necessary for the HIV life cycle. In this study, we investigated the role played by HIV-induced CCR5-dependent cell signaling during infection of primary CD4-expressing leukocytes. ...

  16. Achieving Pure Deep-Blue Electroluminescence with CIE y≤0.06 via a Rational Design Approach for Highly Efficient Non-Doped Solution-Processed Organic Light-Emitting Diodes.

    Science.gov (United States)

    Reddy, Saripally Sudhaker; Sree, Vijaya Gopalan; Cho, Woosum; Jin, Sung-Ho

    2016-11-22

    Deep-blue fluorescent emitters with Commission Internationale de l'Eclairage (CIE) y≤0.06 are urgently needed for high-density storage, full-color displays and solid-state lighting. However, developing such emitters with high color purity and efficiency in solution-processable non-doped organic light-emitting diodes (OLEDs) remains an important challenge. Here, we present the synthesis of two new deep-blue fluorescent emitters (AFpTPI and AFmTPI) based on 10-(9,9-diethyl-9H-fluoren-2-yl)-9,9-dimethyl-9,10-dihydroacridine as a core and 1,3- and/or 1,4-phenylene-linked triphenylimidazole (TPI) analogues for non-doped solution-processable OLEDs. Their thermal, photophysical, electrochemical, and device characteristics are explored, and also strongly supported by density functional theory (DFT) study. AFpTPI and AFmTPI exhibit excellent thermal stability (≈450 °C) with high glass transition temperatures (Tg ; 141-152 °C) and deep-blue emission with high quantum yields. Specifically, the solution-processed non-doped device with AFpTPI as an emitter exhibits a maximum external quantum efficiency (EQE) of 4.56 % with CIE coordinates of (0.15, 0.06), which exactly matches the European Broadcasting Union (EBU) blue standard. In addition, AFmTPI also displays good efficiency and better color purity (EQE: 3.37 %; CIE (0.15, 0.05)). To the best of our knowledge, the present work is the first report on non-doped solution-processable OLEDs with efficiency close to 5 % and CIE y≤0.06.

  17. Lesion simulating disease1, enhanced disease susceptibility1, and phytoalexin deficient4 conditionally regulate cellular signaling homeostasis, photosynthesis, water use efficiency, and seed yield in Arabidopsis.

    Science.gov (United States)

    Wituszynska, Weronika; Slesak, Ireneusz; Vanderauwera, Sandy; Szechynska-Hebda, Magdalena; Kornas, Andrzej; Van Der Kelen, Katrien; Mühlenbock, Per; Karpinska, Barbara; Mackowski, Sebastian; Van Breusegem, Frank; Karpinski, Stanislaw

    2013-04-01

    There is growing evidence that for a comprehensive insight into the function of plant genes, it is crucial to assess their functionalities under a wide range of conditions. In this study, we examined the role of lesion simulating disease1 (LSD1), enhanced disease susceptibility1 (EDS1), and phytoalexin deficient4 (PAD4) in the regulation of photosynthesis, water use efficiency, reactive oxygen species/hormonal homeostasis, and seed yield in Arabidopsis (Arabidopsis thaliana) grown in the laboratory and in the field. We demonstrate that the LSD1 null mutant (lsd1), which is known to exhibit a runaway cell death in nonpermissive conditions, proves to be more tolerant to combined drought and high-light stress than the wild type. Moreover, depending on growing conditions, it shows variations in water use efficiency, salicylic acid and hydrogen peroxide concentrations, photosystem II maximum efficiency, and transcription profiles. However, despite these changes, lsd1 demonstrates similar seed yield under all tested conditions. All of these traits depend on EDS1 and PAD4. The differences in the pathways prevailing in the lsd1 in various growing environments are manifested by the significantly smaller number of transcripts deregulated in the field compared with the laboratory, with only 43 commonly regulated genes. Our data indicate that LSD1, EDS1, and PAD4 participate in the regulation of various molecular and physiological processes that influence Arabidopsis fitness. On the basis of these results, we emphasize that the function of such important regulators as LSD1, EDS1, and PAD4 should be studied not only under stable laboratory conditions, but also in the environment abounding in multiple stresses.

  18. 可传输音频信号的简易无线充电器设计%The design of a simple wireless charger that can achieve audio signal transmission

    Institute of Scientific and Technical Information of China (English)

    旭东; 彭华雨; 任重伟; 张建军

    2015-01-01

    无线充电技术是近年新出现的一种充电方式,其极大的方便性在很多方面有重要的应用,所以扩展无线充电器的应用功能必不可少。基于电磁耦合共振原理设计一种充电过程中可同时进行音频信号传输的无线充电装置,实现信号、能量同时传递的多功能化。针对无线充电器的电磁场分布和发射电路的设计,从工作原理到电路逐步分析,并通过实验验证此装置的可行性,为无线充电器的发展提供一种可行的方案。%Wireless charging technology is a new way of charging. Its great convenience finds important applications in many aspects, so it’s indispensible to expand the appliances of wireless charging. The wireless charger based on the electromagnetic coupling resonance principle this paper desingnes a wireless charging device that can simultaneously tranfer audio and visual signals and realizes audio signal transmission and energy transfer. This paper Aiming at the electromagnetic field distribution of wireless charger and the design of transmitting circuit, the team analyses the working principle and the transmitting circuit step by step. The feasibility of this device is verified by experiment. This paper provides a feasible project for the development of the wireless charger.

  19. Faster than Nyquist signaling algorithms to silicon

    CERN Document Server

    Dasalukunte, Deepak; Rusek, Fredrik; Anderson, John B

    2014-01-01

    This book addresses the challenges and design trade-offs arising during the hardware design of Faster-than-Nyquist (FTN) signaling transceivers. The authors describe how to design for coexistence between the FTN system described and Orthogonal frequency-division multiplexing (OFDM) systems, enabling readers to design FTN specific processing blocks as add-ons to the conventional transceiver chain.   • Provides a comprehensive introduction to Faster-than-Nyquist (FTN) signaling transceivers, covering both theory and hardware implementation; • Enables readers to design systems that achieve bandwidth efficiency by making better use of the available spectrum resources; • Describes design techniques to achieve 2x improvement in bandwidth usage with similar performance as that of an OFDM system.  

  20. Herbivory of wild Manduca sexta causes fast down-regulation of photosynthetic efficiency in Datura wrightii: an early signaling cascade visualized by chlorophyll fluorescence.

    Science.gov (United States)

    Barron-Gafford, Greg A; Rascher, Uwe; Bronstein, Judith L; Davidowitz, Goggy; Chaszar, Brian; Huxman, Travis E

    2012-09-01

    Plants experiencing herbivory suffer indirect costs beyond direct loss of leaf area, but differentially so based on the herbivore involved. We used a combination of chlorophyll fluorescence imaging and gas exchange techniques to quantify photosynthetic performance, the efficiency of photochemistry, and heat dissipation to examine immediate and longer-term physiological responses in the desert perennial Datura wrightii to herbivory by tobacco hornworm, Manduca sexta. Herbivory by colony-reared larvae yielded no significant reduction in carbon assimilation, whereas herbivory by wild larvae induced a fast and spreading down-regulation of photosynthetic efficiency, resulting in significant losses in carbon assimilation in eaten and uneaten leaves. We found both an 89 % reduction in net photosynthetic rates in herbivore-damaged leaves and a whole-plant response (79 % decrease in undamaged leaves from adjacent branches). Consequently, herbivory costs are higher than previously estimated in this well-studied plant-insect interaction. We used chlorophyll fluorescence imaging to elucidate the mechanisms of this down-regulation. Quantum yield decreased up to 70 % in a small concentric band surrounding the feeding area within minutes of the onset of herbivory. Non-photochemical energy dissipation by the plant to avoid permanent damage was elevated near the wound, and increased systematically in distant areas of the leaf away from the wound over subsequent hours. Together, the results underscore not only potential differences between colony-reared and wild-caught herbivores in experimental studies of herbivory but also the benefits of quantifying physiological responses of plants in unattacked leaves.

  1. Analysis for the feasibility of achieving high yield and nutrient efficiency at low fertilizer input%低化肥投入下作物高产和养分高效的可行性分析

    Institute of Scientific and Technical Information of China (English)

    周玲; 王朝辉; 薛澄; 李生秀

    2011-01-01

    Overuse of chemical fertilizer has led to both high production costs and serious risk of environmental pollution. Therefore, reduction of fertilizer input while increasing its efficiency will be crucially important for sustainable agriculture. This paper compared chemical fertilizer rates and grain yield of the main crops in different countries, analysed the typical instances that decreased fertilizer use did not lead to obvious reduction of crop yield in western European countries, and found that high grain yield with high nutrient use efficiency could be realized at the same time by rational nutrient management. Based on the successful experience abroad and the agricultural practice in China, we found that halancing nutrient supply, fully use of nutrients other than that from fertilizers and further exploring the biological potential of crops are three important ways for realizing high grain yield with high nutrient use efficiency. Nowadays, basic research is urgently needed for decreasing chemical fertilizer input, and comprehensive management on nutrient resources should be enhanced at the same time.%对比了不同国家主要粮食作物的化肥用量与产量,分析了西欧国家降低化肥投入并未导致粮食产量大幅下降的实例,得出降低化肥投入实现作物高产和养分高效利用是完全可能的.结合国外成功的经验和我国的生产实际,提出我国应通过协调养分间的平衡,充分发挥化肥以外的其他养分的作用,挖掘作物自身的生物学潜力三个途径实现低化肥投入条件下的作物高产和养分资源高效利用.当前,我国急需开展低化肥投入的基础研究,同时加强养分资源的宏观管理.

  2. Effect of alpha and Gaussian refractive index profiles on the design of highly nonlinear optical fibre for efficient nonlinear optical signal processing

    Science.gov (United States)

    Selvendran, S.; Sivanantharaja, A.; Arivazhagan, S.; Kannan, M.

    2016-09-01

    We propose an index profiled, highly nonlinear ultraflattened dispersion fibre (HN-UFF) with appreciable values of fibre parameters such as dispersion, dispersion slope, effective area, nonlinearity, bending loss and splice loss. The designed fibre has normal zero flattened dispersion over S, C, L, U bands and extends up to 1.9857 μm. The maximum dispersion variation observed for this fibre is as low as 1.61 ps km-1 nm-1 over the 500-nm optical fibre transmission spectrum. This fibre also has two zero dispersion wavelengths at 1.487 and 1.9857 μm and the respective dispersion slopes are 0.02476 and 0.0068 ps nm-2 km-1. The fibre has a very low ITU-T cutoff wavelength of 1.2613 μm and a virtuous nonlinear coefficient of 9.43 W-1 km-1. The wide spectrum of zero flattened dispersion and a good nonlinear coefficient make the designed fibre very promising for different nonlinear optical signal processing applications.

  3. Pretreatment of Sialic Acid Efficiently Prevents Lipopolysaccharide-Induced Acute Renal Failure and Suppresses TLR4/gp91-Mediated Apoptotic Signaling

    Directory of Open Access Journals (Sweden)

    Shih-Ping Hsu

    2016-05-01

    Full Text Available Background/Aims: Lipopolysaccharides (LPS binding to Toll-like receptor 4 (TLR4 activate NADPH oxidase gp91 subunit-mediated inflammation and oxidative damage. Recognizing the high binding affinity of sialic acid (SA with LPS, we further explored the preventive potential of SA pretreatment on LPS-evoked acute renal failure (ARF. Methods: We determined the effect of intravenous SA 30 min before LPS-induced injury in urethane-anesthetized female Wistar rats by evaluating kidney reactive oxygen species (ROS responses, renal and systemic hemodynamics, renal function, histopathology, and molecular mechanisms. Results: LPS time-dependently reduced arterial blood pressure, renal microcirculation, and increased blood urea nitrogen and creatinine in the rats. LPS enhanced monocyte/macrophage infiltration and ROS production, and subsequently impaired kidneys with the enhancement of TLR4/NADPH oxidase gp91/Caspase 3/poly-(ADP-ribose-polymerase (PARP-mediated apoptosis in the kidneys. SA pretreatment effectively alleviated LPS-induced ARF. The levels of LPS-increased ED-1 infiltration and ROS production in the kidney were significantly depressed by SA pretreatment. Furthermore, SA pretreatment significantly depressed TLR4 activation, gp91 expression, and Caspase 3/PARP induced apoptosis in the kidneys. Conclusion: We suggest that pretreatment of SA significantly and preventively attenuated LPS-induced detrimental effects on systemic and renal hemodynamics, renal ROS production and renal function, as well as, LPS-activated TLR4/gp91/Caspase3 mediated apoptosis signaling.

  4. 'No delays achiever'.

    Science.gov (United States)

    2007-05-01

    The latest version of the NHS Institute for Innovation and Improvement's 'no delays achiever', a web based tool created to help NHS organisations achieve the 18-week target for GP referrals to first treatment, is available at www.nodelaysachiever.nhs.uk.

  5. SignalR blueprints

    CERN Document Server

    Ingebrigtsen, Einar

    2015-01-01

    This book is designed for software developers, primarily those with knowledge of C#, .NET, and JavaScript. Good knowledge and understanding of SignalR is assumed to allow efficient programming of core elements and applications in SignalR.

  6. The Wnt signaling pathway in cancer.

    Science.gov (United States)

    Duchartre, Yann; Kim, Yong-Mi; Kahn, Michael

    2016-03-01

    The Wnt signaling pathway is critically involved in both the development and homeostasis of tissues via regulation of their endogenous stem cells. Aberrant Wnt signaling has been described as a key player in the initiation of and/or maintenance and development of many cancers, via affecting the behavior of Cancer Stem Cells (CSCs). CSCs are considered by most to be responsible for establishment of the tumor and also for disease relapse, as they possess inherent drug-resistance properties. The development of new therapeutic compounds targeting the Wnt signaling pathway promises new hope to eliminate CSCs and achieve cancer eradication. However, a major challenge resides in developing a strategy efficient enough to target the dysregulated Wnt pathway in CSCs, while being safe enough to not damage the normal somatic stem cell population required for tissue homeostasis and repair. Here we review recent therapeutic approaches to target the Wnt pathway and their clinical applications.

  7. Power Efficient Design of DisplayPort (7.0) Using Low-voltage differential signaling IO Standard Via UltraScale Field Programming Gate Arrays

    DEFF Research Database (Denmark)

    Das, Bhagwan; Abdullah, M.F.L.; Hussain, Dil muhammed Akbar

    2017-01-01

    Port (7.0) need be reduced. In this paper, a power efficient design for DisplayPort (7.0) is proposed using LVDS IO Standard. The proposed design is tested for different frequencies; 500 MHz, 700 MHz, 1.0 GHz, and 1.6 GHz. The design is implemented using vhdl in UltraScale FPGA. It is determined...... the designed vhdl based design of DisplayPort (7.0) can reduced 92% using LVDS IO Standard for all frequencies; 500 MHz, 700 MHz, 1.0 GHz, and 1.6 GHz, compared to vhdl based design of DisplayPort (7.0) without using IO Standard. The proposed design of vhdl based design of DisplayPort (7.0) using LVDS IO...... Standard offers no power consumption for DisplayPort (7.0) in standby mode. The vhdl based design of DisplayPort (7.0) using LVDS IO Standard will be helpful to process the high resolution video at low power consumption...

  8. Achievement report for fiscal 1998. Leading research and development of MGC-built superhigh-efficiency turbine system technology; 1998 nendo MGC chokokoritsu turbine system gijutsu sendo kenkyu kaihatsu kenkyu seika

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    To further enhance energy efficiency by improving on the gas turbine system, it is necessary, first of all, to develop superhigh-temperature materials to allow the system to operate at higher temperatures. Described in this report are studies on the application of MGC (melt-growth composite) materials which retain strength and plastic deformation capability even at high temperatures. Various compositions are explored for improvement on fracture toughness and thermal shock resistance. The Al{sub 2}O{sub 3}/YAG system is investigated for the study of relations between microstructural control and fracture toughness. Literature on the development of nanocomposites is surveyed, and a preliminary experiment is discussed for improvement on purity by zone melting crystallization. In a study for an advanced manufacture of larger crystals, technologies of crystal growth condition setting and optimization, quality stabilization, productivity improvement, and crystal size enlargement are taken up. Casting and machining technologies are studied to enable crystals to assume complicated shapes. For the purpose of elucidating the mechanism of the occurrence of properties proper to high temperatures, a study is made on the evaluation of mechanical and physical properties and on the mechanism and control of crystal growth. Also studied are systems (gas turbine cycle, combustor, etc.) to which MGC materials may be applied. (NEDO)

  9. Analysis of the methods for the achievement of comfort conditions of humidity and temperature in energetically efficient designs; Analisis de los mtodos para lograr condiciones de confort higrotermico en disenos energeticamente eficientes

    Energy Technology Data Exchange (ETDEWEB)

    Mesa A., N. A.; Morillon G., D. [Division de Estudios de Posgrado de la Facultad de Arquitectura, Universidad Nacional Autonoma de Mexico (Mexico)

    1997-12-31

    This paper presents the analysis of the tools commonly utilized in Bioclimatic Design, for the achievement of humidity an temperature comfort conditions in architectonic spaces. The analysis was performed by means of field studies and experimentally for different sport activities, carried out in spaces designed for each purpose. In the experimental part, inside ambient temperature and relative humidity were measured in the different spaces where sport activities were conducted, such as calisthenics, dance, judo, wrestling, weight lifting, boxing, basket-ball, volley-ball, gymnastics and fencing. At the same time an inquiry was conducted among their occupants in respect to the thermal sensation they experimented while conducting such activities. The results obtained in the inquiry were compared with the results reported by other researchers, by means of tables and psychometric diagrams as optimum values for temperature comfort. As a conclusion it was decided that the graphic and mathematical methods analyzed, are based on a sedentary activity, therefore in using them for the design of spaces for different activities uncomfortable conditions are experimented with the consequential necessity of air conditioning, which implies energy consumption and the corresponding expenditure, lastly it is necessary to adapt these tools, that is, consider the activity that is going to be performed in the buildings. [Espanol] En este documento se presenta el analisis de las herramientas, comunmente utilizadas en Diseo Bioclimatico, para lograr el confort higrotermico de espacios arquitectonicos, el analisis se realizo mediante estudios de campo y experimental, para diversas actividades deportivas, llevadas a cabo en espacios disenados para ello. En la parte experimental, se tomaron mediciones de temperatura y humedad relativa internas, de los distintos espacios en los cuales se desarrollaban las actividades deportivas, tales como calistenia, danza, judo, lucha, trabajo con pesas

  10. Crash patterns at signalized intersections

    OpenAIRE

    Polders, Evelien; Daniels, Stijn; HERMANS, Elke; Brijs, Tom; Wets, Geert

    2015-01-01

    Traffic signals are often implemented to provide for efficient movement and to improve traffic safety. Nevertheless, severe crashes still occur at signalized intersections. This study aims to improve the understanding of signalized intersection safety by identifying crash types, locations and factors associated with signalized intersections. For this purpose, 1295 police-reported crashes at 87 signalized intersections are analyzed based on detailed crash descriptions, i.e. crash data and c...

  11. Transcriptional regulation by an NAC (NAM-ATAF1,2-CUC2) transcription factor attenuates ABA signalling for efficient basal defence towards Blumeria graminis f. sp hordei in Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Hagedorn, Peter; De Torres-Zabala, Marta

    2008-01-01

    -representation of abscisic acid (ABA)-responsive genes, including the ABA biosynthesis gene AAO3, which is significantly induced in ataf1 plants compared to wild-type plants following inoculation with Bgh. Additionally, we show that Bgh inoculation results in decreased endogenous ABA levels in an ATAF1-dependent manner......, and that the ABA biosynthetic mutant aao3 showed increased penetration resistance to Bgh compared to wild-type plants. Furthermore, we show that ataf1 plants show ABA-hyposensitive phenotypes during seedling development and germination. Our data support a negative correlation between ABA levels and penetration...... resistance, and identify ATAF1 as a new stimuli-dependent attenuator of ABA signalling for the mediation of efficient penetration resistance in Arabidopsis upon Bgh attack....

  12. Enhancing the efficiency of direct reprogramming of human mesenchymal stem cells into mature neuronal-like cells with the combination of small molecule modulators of chromatin modifying enzymes, SMAD signaling and cyclic adenosine monophosphate levels.

    Science.gov (United States)

    Alexanian, Arshak R; Liu, Qing-song; Zhang, Zhiying

    2013-08-01

    Advances in cell reprogramming technologies to generate patient-specific cells of a desired type will revolutionize the field of regenerative medicine. While several cell reprogramming methods have been developed over the last decades, the majority of these technologies require the exposure of cell nuclei to reprogramming large molecules via transfection, transduction, cell fusion or nuclear transfer. This raises several technical, safety and ethical issues. Chemical genetics is an alternative approach for cell reprogramming that uses small, cell membrane penetrable substances to regulate multiple cellular processes including cell plasticity. Recently, using the combination of small molecules that are involved in the regulation chromatin structure and function and agents that favor neural differentiation we have been able to generate neural-like cells from human mesenchymal stem cells. In this study, to improve the efficiency of neuronal differentiation and maturation, two specific inhibitors of SMAD signaling (SMAD1/3 and SMAD3/5/8) that play an important role in neuronal differentiation of embryonic stem cells, were added to our previous neural induction recipe. Results demonstrated that human mesenchymal stem cells grown in this culture conditions exhibited higher expression of several mature neuronal genes, formed synapse-like structures and exerted electrophysiological properties of differentiating neural stem cells. Thus, an efficient method for production of mature neuronal-like cells from human adult bone marrow derived mesenchymal stem cells has been developed. We concluded that specific combinations of small molecules that target specific cell signaling pathways and chromatin modifying enzymes could be a promising approach for manipulation of adult stem cell plasticity.

  13. Neutron signal transfer analysis

    CERN Document Server

    Pleinert, H; Lehmann, E

    1999-01-01

    A new method called neutron signal transfer analysis has been developed for quantitative determination of hydrogenous distributions from neutron radiographic measurements. The technique is based on a model which describes the detector signal obtained in the measurement as a result of the action of three different mechanisms expressed by signal transfer functions. The explicit forms of the signal transfer functions are determined by Monte Carlo computer simulations and contain only the distribution as a variable. Therefore an unknown distribution can be determined from the detector signal by recursive iteration. This technique provides a simple and efficient tool for analysis of this type while also taking into account complex effects due to the energy dependency of neutron interaction and single and multiple scattering. Therefore this method provides an efficient tool for precise quantitative analysis using neutron radiography, as for example quantitative determination of moisture distributions in porous buil...

  14. Capacity Achieving Modulation for Fixed Constellations with Average Power Constraint

    CERN Document Server

    Bocherer, Georg; Mathar, Rudolf

    2010-01-01

    The capacity achieving probability mass function (PMF) of a finite signal constellation with an average power constraint is in most cases non-uniform. A common approach to generate non-uniform input PMFs is Huffman shaping, which consists of first approximating the capacity achieving PMF by a sampled Gaussian density and then to calculate the Huffman code of the sampled Gaussian density. The Huffman code is then used as a prefix-free modulation code. This approach showed good results in practice, can however lead to a significant gap to capacity. In this work, a method is proposed that efficiently constructs optimal prefix-free modulation codes for any finite signal constellation with average power constraint in additive noise. The proposed codes operate as close to capacity as desired. The major part of this work elaborates an analytical proof of this property. The proposed method is applied to 64-QAM in AWGN and numeric results are given, which show that, opposed to Huffman shaping, by using the proposed me...

  15. Genomic Signal Enhancement by Clustering

    Institute of Scientific and Technical Information of China (English)

    ZHENG Wei-Mou

    2003-01-01

    Weight matrix models for signal sequence motif are simple. A main limitation of the models is the assumption of independence between positions. Signal enhancement is achieved by taking the total likelihood as the objective function for maximization to cluster sequences into groups with different patterns. As an example, the initial and terminal signals for translation in rice genome are examined.

  16. Sensor selection for received signal strength-based source localization in wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Generally, localization is a nonlinear problem, while linearization is used to simplify this problem. Reasonable approximations could be achieved when signal-to-noise ratio (SNR) is large enough. Energy is a critical resource in wireless sensor networks, and system lifetime needs to be prolonged through the use of energy efficient strategies during system operation. In this paper, a closed-form solution for received signal strength (RSS)-based source localization in wireless sensor network (WSN) is obtained...

  17. Signal Words

    Science.gov (United States)

    SIGNAL WORDS TOPIC FACT SHEET NPIC fact sheets are designed to answer questions that are commonly asked by the ... making decisions about pesticide use. What are Signal Words? Signal words are found on pesticide product labels, ...

  18. Separating cyclostationary signals from spectrally overlapping interference

    Institute of Scientific and Technical Information of China (English)

    GUO Jie; LIU Yun; YE Zhi-hui; SONG Tie-cheng; SHEN Lian-feng

    2006-01-01

    This paper studies an algorithm about separating spectmlly overlapping signals using the cyclostationary properties of signals.On the basis of direct sequence spread system (DSSS),frequency shift filter is added into the receiver of the communication system.Although the structure of frequency shift filter is more complicated than the time-domain filter,it uses both time correlations and frequency spectrum correlations so it can achieve better performances on separating the overlapping signals.After the analysis of cyclostationary characteristic and frequency spectrum correlation,the structure of the frequency shift filter can be gained.Then,a self-adaptive algorithm is utilized for the purpose of achieving optimum multidimensional tap weights of frequency shift components.The simulation results indicate that this method can efficiently separate overlapping signals,and its error rate is lower than the time-domain filter or DSSS system by two orders of magnitude on the condition that high-power interference is added into the system.

  19. Acoustic Signal Processing

    Science.gov (United States)

    Hartmann, William M.; Candy, James V.

    Signal processing refers to the acquisition, storage, display, and generation of signals - also to the extraction of information from signals and the re-encoding of information. As such, signal processing in some form is an essential element in the practice of all aspects of acoustics. Signal processing algorithms enable acousticians to separate signals from noise, to perform automatic speech recognition, or to compress information for more efficient storage or transmission. Signal processing concepts are the building blocks used to construct models of speech and hearing. Now, in the 21st century, all signal processing is effectively digital signal processing. Widespread access to high-speed processing, massive memory, and inexpensive software make signal processing procedures of enormous sophistication and power available to anyone who wants to use them. Because advanced signal processing is now accessible to everybody, there is a need for primers that introduce basic mathematical concepts that underlie the digital algorithms. The present handbook chapter is intended to serve such a purpose.

  20. NCLB: Achievement Robin Hood?

    Science.gov (United States)

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the…

  1. Cognitive Processes and Achievement.

    Science.gov (United States)

    Hunt, Dennis; Randhawa, Bikkar S.

    For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

  2. Impact Analysis of Baseband Quantizer on Coding Efficiency for HDR Video

    Science.gov (United States)

    Wong, Chau-Wai; Su, Guan-Ming; Wu, Min

    2016-10-01

    Digitally acquired high dynamic range (HDR) video baseband signal can take 10 to 12 bits per color channel. It is economically important to be able to reuse the legacy 8 or 10-bit video codecs to efficiently compress the HDR video. Linear or nonlinear mapping on the intensity can be applied to the baseband signal to reduce the dynamic range before the signal is sent to the codec, and we refer to this range reduction step as a baseband quantization. We show analytically and verify using test sequences that the use of the baseband quantizer lowers the coding efficiency. Experiments show that as the baseband quantizer is strengthened by 1.6 bits, the drop of PSNR at a high bitrate is up to 1.60dB. Our result suggests that in order to achieve high coding efficiency, information reduction of videos in terms of quantization error should be introduced in the video codec instead of on the baseband signal.

  3. A New Two-Branch Amplification Architecture and its Application with Various Modulated Signals

    Institute of Scientific and Technical Information of China (English)

    W. Hamdane; A. B. Kouki; F. Gagnon

    2011-01-01

    This paper proposes a new two-branch amplification architecture that combines baseband signal decomposition with RF front-end optimization. In the proposed architecture, the filtered modulated signals are separated into two components that are then amplified independently and combined to regenerate an amplified version of the original signal. A branch with an efficient amplifier transmits a low-varying envelope signal that contains the main part of the information. Another branch amplifies the residual portion of the signal. The baseband decomposition and parameters of the RF part are optimized to find the configuration that gives the best power efficiency and linearity. For M-ary quadrature amplitude modulation (M-QAM) signals, this technique is limited in terms of power efficiency. However, for filtered continuous phase modulation (CPM) signals, especially for minimum shift keying (MSK) and Gaussian MSK (GMSK) signals, high power efficiency can be achieved with no significant impact on the overall linearity. The results show that this technique gives better performance than the single-ended ctass-B amplifier.

  4. Industrial energy efficiency: Achieving success in a difficult environment

    Energy Technology Data Exchange (ETDEWEB)

    Castellow, Carl

    2010-09-15

    Energy use and the resulting environmental impacts are major points of concern for the world in the 21st century. Opinions that define the challenges of sustainable energy options are as diverse as the proposed solutions. The industrial sector is a key area both from the standpoint of the amount of energy consumed and the magnitude of the energy options that exist there. However, history has shown that success in the industrial energy sector requires careful planning and consideration of the unique challenges of the manufacturing environment.

  5. DOD Joint Bases: Management Improvements Needed to Achieve Greater Efficiencies

    Science.gov (United States)

    2012-11-01

    bases should maintain a clean and healthy environment by cleaning certain restrooms three times a week, and should sweep and mop floors, vacuum carpets ...remove trash, and clean walk-off mats once a week; buff floors monthly; and maintain/strip floors and shampoo carpets annually. Officials at Joint...Fraud, Waste, and Abuse in Federal Programs Congressional Relations Public Affairs Please Print on Recycled Paper.

  6. Greater Energy Efficiency can be Achieved through Land Use Management.

    Science.gov (United States)

    1981-12-21

    LANDSCAPE ARCHITECTS FOUNDATION, LANDSCAPE PLANNING FOR ENERGY CONSERVATION, ENVIRONMENTAL DESIGN PRESS. 1977 I/American Society of Landscape Architects...Foundation, Landscape Planning for Energy Conservation, Environmental Design Press, 1977, p. 54. 10 Trnees~: and vegetation can also be orientated to help...BUILDINGS 1. American Society of Landscape Architects Foundation, Landscape Planning for Energy Conservation, Environmental Design Press, 1977. Examines the

  7. Drilling Featured for Quality and Speed Achieves Higher Development Efficiency

    Institute of Scientific and Technical Information of China (English)

    Zhang Quanwang; Rong Jiashu

    1997-01-01

    @@ Several heated discussions were carried out by CNOOC in 1993 on the development of Oilfield Jinzhou 9-3,Bohai Bay. Oilfield Jinzhou 9-3 is proved to have reserves nearly of 3 × 106 t, but it was finally put out of development due to failure to reach the minimum profitability set by CNOOC, which was ascribed mainly to long drilling cycle and high cost.

  8. Achieveing Organizational Excellence Through

    Directory of Open Access Journals (Sweden)

    Mehdi Abzari

    2009-04-01

    Full Text Available AbstractToday, In order to create motivation and desirable behavior in employees, to obtain organizational goals,to increase human resources productivity and finally to achieve organizational excellence, top managers oforganizations apply new and effective strategies. One of these strategies to achieve organizational excellenceis creating desirable corporate culture. This research has been conducted to identify the path to reachorganizational excellence by creating corporate culture according to the standards and criteria oforganizational excellence. The result of the so-called research is this paper in which researchers foundtwenty models and components of corporate culture and based on the Industry, organizational goals andEFQM model developed a model called "The Eskimo model of Culture-Excellence". The method of theresearch is survey and field study and the questionnaires were distributed among 116 managers andemployees. To assess the reliability of questionnaires, Cronbach alpha was measured to be 95% in the idealsituation and 0/97 in the current situation. Systematic sampling was done and in the pre-test stage 45questionnaires were distributed. A comparison between the current and the ideal corporate culture based onthe views of managers and employees was done and finally it has been concluded that corporate culture isthe main factor to facilitate corporate excellence and success in order to achieve organizational effectiveness.The contribution of this paper is that it proposes a localized –applicable model of corporate excellencethrough reinforcing corporate culture.

  9. Capacity-achieving CPM schemes

    CERN Document Server

    Perotti, Alberto; Benedetto, Sergio; Montorsi, Guido

    2008-01-01

    The pragmatic approach to coded continuous-phase modulation (CPM) is proposed as a capacity-achieving low-complexity alternative to the serially-concatenated CPM (SC-CPM) coding scheme. In this paper, we first perform a selection of the best spectrally-efficient CPM modulations to be embedded into SC-CPM schemes. Then, we consider the pragmatic capacity (a.k.a. BICM capacity) of CPM modulations and optimize it through a careful design of the mapping between input bits and CPM waveforms. The so obtained schemes are cascaded with an outer serially-concatenated convolutional code to form a pragmatic coded-modulation system. The resulting schemes exhibit performance very close to the CPM capacity without requiring iterations between the outer decoder and the CPM demodulator. As a result, the receiver exhibits reduced complexity and increased flexibility due to the separation of the demodulation and decoding functions.

  10. Achievement report for fiscal 1997 on the technological development for practical application of a solar energy power generation system. Development of technology to manufacture ultra-high efficiency crystal compound solar cells; 1997 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu. Chokokoritsu kessho kagobutsu taiyo denchi no seizo gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The present research is intended to develop hetero-epitaxy technology for compound semiconductors on silicon substrates, and hetero-epitaxy technology for grid mismatch between III-V family compound semiconductors, and realize high-efficiency solar cells on silicon substrates. Based on the InP-based etching using a reactive ion etching device, etching conditions suitable for contact layer removal and element separation were obtained. The InP substrate etched under the optimized condition was found etched ideally. Test samples were made, which use a GaAs layer grown at high V/III ratio as the buffer layer, and its effect on crystallization performance was investigated. As a result, it was found that making the V/III ratio high can achieve reduction in defect density and improvement in crystallization performance. A three-stage growth method was used to improve efficiency of GaAs/Si cells, and heat treatment temperature was optimized for an attempt of improving the cell efficiency. It was revealed that rise in the open terminal voltage contributes to improving the cell characteristics at annealing temperatures higher than 950 degrees C or higher, which has been used on a trial basis during this fiscal year. (NEDO)

  11. Nonlinear Silicon Photonic Signal Processing Devices for Future Optical Networks

    Directory of Open Access Journals (Sweden)

    Cosimo Lacava

    2017-01-01

    Full Text Available In this paper, we present a review on silicon-based nonlinear devices for all optical nonlinear processing of complex telecommunication signals. We discuss some recent developments achieved by our research group, through extensive collaborations with academic partners across Europe, on optical signal processing using silicon-germanium and amorphous silicon based waveguides as well as novel materials such as silicon rich silicon nitride and tantalum pentoxide. We review the performance of four wave mixing wavelength conversion applied on complex signals such as Differential Phase Shift Keying (DPSK, Quadrature Phase Shift Keying (QPSK, 16-Quadrature Amplitude Modulation (QAM and 64-QAM that dramatically enhance the telecom signal spectral efficiency, paving the way to next generation terabit all-optical networks.

  12. Efficient and Accurate WLAN Positioning with Weighted Graphs

    DEFF Research Database (Denmark)

    Hansen, Rene; Thomsen, Bent

    2009-01-01

    , tracking moving users requires a low-latency overhead which translates into efficient computations to be done on a mobile device with limited capabilities. We present a technique to simultaneously improve the positioning accuracy and computational efficiency. The technique utilizes a weighted graph model...... indicate that we are able to achieve similar dynamic localization accuracy to static localization. Effectively, we are able to counter the adverse effects of added signal fluctuations caused by movement. However, as some of our experiments testify, any location system is fundamentally constrained...

  13. Achieving form in autobiography

    Directory of Open Access Journals (Sweden)

    Nicholas (Nick Meihuizen

    2014-06-01

    Full Text Available This article argues that, unlike biographies which tend to follow patterns based on conventional expectations, salient autobiographies achieve forms unique to themselves. The article draws on ideas from contemporary formalists such as Peter McDonald and Angela Leighton but also considers ideas on significant form stemming from earlier writers and critics such as P.N. Furbank and Willa Cather. In extracting from these writers the elements of what they consider comprise achieved form, the article does not seek to provide a rigid means of objectively testing the formal attributes of a piece of writing. It rather offers qualitative reminders of the need to be alert to the importance of form, even if the precise nature of this importance is not possible to define. Form is involved in meaning, and this continuously opens up possibilities regarding the reader’s relationship with the work in question. French genetic critic Debray Genette distinguishes between ‘semantic effect’ (the direct telling involved in writing and ‘semiological effect’ (the indirect signification involved. It is the latter, the article argues in summation, which gives a work its singular nature, producing a form that is not predictable but suggestive, imaginative.

  14. Achieving monospermy or preventing polyspermy?

    Directory of Open Access Journals (Sweden)

    Dale B

    2016-06-01

    Full Text Available Brian Dale Centre for Assisted Fertilization, Naples, Italy Abstract: Images of sea urchin oocytes with hundreds of spermatozoa attached to their surface have fascinated scientists for over a century and led to the idea that oocytes have evolved mechanisms to allow the penetration of one spermatozoon while repelling supernumerary spermatozoa. Popular texts have extrapolated this concept, to the mammals and amphibians, and in many cases to include all the Phyla. Here, it is argued that laboratory experiments, using sea urchin oocytes deprived of their extracellular coats and inseminated at high densities, are artifactual and that the experiments leading to the idea of a fast block to polyspermy are flawed. Under natural conditions, the number of spermatozoa at the site of fertilization is extremely low, compared with the numbers generated. The sperm:oocyte ratio is regulated first by dilution in externally fertilizing species and the female reproductive tract in those with internal fertilization, followed by a bottleneck created by the oocytes extracellular coats. In order to progress to the oocyte plasma membrane, the fertilizing spermatozoon must encounter and respond to a correct sequence of signals from the oocytes extracellular coats. Those that do not, are halted in their progression by defective signaling and fall to the wayside. Final success and entry is finely tuned by the spermatozoon anchoring to an actin-rich predetermined site on the plasma membrane. In this review, the variation in the form, function, and number of gametes produced across the animal kingdom and the many ways in which sperm–oocyte interactions are regulated to reduce numbers are discussed. Since in nature, final sperm:oocyte ratios approach unity it would appear that selective pressures have favored the achievement of monospermy, rather than the evolution of polyspermy preventing mechanisms. Keywords: monospermy, natural conditions, polyspermy, laboratory

  15. Achieving diagnosis by consensus

    LENUS (Irish Health Repository)

    Kane, Bridget

    2009-08-01

    This paper provides an analysis of the collaborative work conducted at a multidisciplinary medical team meeting, where a patient’s definitive diagnosis is agreed, by consensus. The features that distinguish this process of diagnostic work by consensus are examined in depth. The current use of technology to support this collaborative activity is described, and experienced deficiencies are identified. Emphasis is placed on the visual and perceptual difficulty for individual specialities in making interpretations, and on how, through collaboration in discussion, definitive diagnosis is actually achieved. The challenge for providing adequate support for the multidisciplinary team at their meeting is outlined, given the multifaceted nature of the setting, i.e. patient management, educational, organizational and social functions, that need to be satisfied.

  16. Recognizing outstanding achievements

    Science.gov (United States)

    Speiss, Fred

    One function of any professional society is to provide an objective, informed means for recognizing outstanding achievements in its field. In AGU's Ocean Sciences section we have a variety of means for carrying out this duty. They include recognition of outstanding student presentations at our meetings, dedication of special sessions, nomination of individuals to be fellows of the Union, invitations to present Sverdrup lectures, and recommendations for Macelwane Medals, the Ocean Sciences Award, and the Ewing Medal.Since the decision to bestow these awards requires initiative and judgement by members of our section in addition to a deserving individual, it seems appropriate to review the selection process for each and to urge you to identify those deserving of recognition.

  17. Achieving English Spoken Fluency

    Institute of Scientific and Technical Information of China (English)

    王鲜杰

    2000-01-01

    Language is first and foremost oral,spoken language,speaking skill is the most important one of the four skills(L,S,R,W)and also it is the most difficult one of the four skills. To have an all-round command of a language one must be able to speak and to understand the spoken language, it is not enough for a language learner only to have a good reading and writing skills. As Englisn language teachers, we need to focus on improving learners' English speaking skill to meet the need of our society and our country and provide learner some useful techniques to achieving their English spoken fluency. This paper focuses on the spoken how to improving learners speaking skill.

  18. Achieving closure at Fernald

    Energy Technology Data Exchange (ETDEWEB)

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  19. FEWER HOURS MORE ACHIEVEMENTS

    Institute of Scientific and Technical Information of China (English)

    NingQuanxin; QiuLizhong

    2004-01-01

    The goal of this study is to improve instructional classes for “Extensive Reading”. We compare two approaches. The traditional method is based on the original procedure; the method we try is a “task-placemented” one. inspired by the method we try is a “task-placemented” one. inspired by the theory of “Tasks of Ascending Difficulty”.This paper provides a comparative evaluation of our experiments on Extensive Reading. Our aim is to resolve the logistical problem of heavy teaching loads and limited class hours, which often prevents English learners from fulfilling their study targets and our intended learning outcomes. In view of the experimental data,we have managed to establish a “feedback” to test the two hypotheses, and demonstrate that the new approach contributes to efficient acquisition of the information in the presented reading materials. Our study concludes with an interpretation of the function and merits of this approach.

  20. Achievement Goals and Achievement Emotions: A Meta-Analysis

    Science.gov (United States)

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  1. ENERGY EFFICIENCY AND GDP

    Directory of Open Access Journals (Sweden)

    Branka Gvozdenac-Urošević

    2010-01-01

    Full Text Available Improving energy efficiency can be powerful tool for achieving sustainable economic development and most important for reducing energy consumption and environmental pollution on national level. Unfortunately, energy efficiency is difficult to conceptualize and there is no single commonly accepted definition. Because of that, measurement of achieved energy efficiency and its impact on national or regional economy is very complicated. Gross Domestic Product (GDP is often used to assess financial effects of applied energy efficiency measures at the national and regional levels. The growth in energy consumption per capita leads to a similar growth in GDP, but it is desirable to provide for the fall of these values. The paper analyzes some standard indicators and the analysis has been applied to a very large sample ensuring reliability for conclusion purposes. National parameters for 128 countries in the world in 2007 were analyzed. In addition to that, parameters were analyzed in the last years for global regions and Serbia.

  2. Revisiting energy efficiency fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Lombard, L.; Velazquez, D. [Grupo de Termotecnia, Escuela Superior de Ingenieros, Universidad de Sevilla, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Ortiz, J. [Building Research Establishment (BRE), Garston, Watford, WD25 9XX (United Kingdom)

    2013-05-15

    Energy efficiency is a central target for energy policy and a keystone to mitigate climate change and to achieve a sustainable development. Although great efforts have been carried out during the last four decades to investigate the issue, focusing into measuring energy efficiency, understanding its trends and impacts on energy consumption and to design effective energy efficiency policies, many energy efficiency-related concepts, some methodological problems for the construction of energy efficiency indicators (EEI) and even some of the energy efficiency potential gains are often ignored or misunderstood, causing no little confusion and controversy not only for laymen but even for specialists. This paper aims to revisit, analyse and discuss some efficiency fundamental topics that could improve understanding and critical judgement of efficiency stakeholders and that could help in avoiding unfounded judgements and misleading statements. Firstly, we address the problem of measuring energy efficiency both in qualitative and quantitative terms. Secondly, main methodological problems standing in the way of the construction of EEI are discussed, and a sequence of actions is proposed to tackle them in an ordered fashion. Finally, two key topics are discussed in detail: the links between energy efficiency and energy savings, and the border between energy efficiency improvement and renewable sources promotion.

  3. Vietnam: achievements and challenges.

    Science.gov (United States)

    Tran Tien Duc

    1999-01-01

    The Vietnamese Government's successful development of the National Population and Family Planning Program has contributed in raising people's awareness on population issues and changing their attitudes and behavior regarding fostering small families. It has also been found to be very effective in substantially decreasing fertility level. In addition, economic levels of many households have been greatly improved since the adoption of a renovation policy. The advancement of welfare accompanied by the provision of better basic social services, including health services, has boost people's health. Several factors behind the achievements of the National Population and Family Planning Program include: 1) Strengthening of the political commitment of national and local leaders; 2) Nationwide mobilization of mass organizations and NGOs; 3) A strong advocacy and information, education and communication program; 4) Provision of various kinds of contraceptives; 5) Effective management of the program by priority; and 6) Support of the international community. Despite such successes, Vietnam is facing a number of new issues such as enlargement of the work force, shifting migration patterns and accelerating urbanization, aging of population, and change of household structure. Nevertheless, the Government of Vietnam is preparing a New Population Strategy aimed to address these issues.

  4. The research on the transformation efficiency of scientific and technological achievements based on the DEA in the western Colleges and Universities%基于DEA的我国西部高校科技成果转化评价研究——以国家重点建设西部十四所高校为例

    Institute of Scientific and Technical Information of China (English)

    任冬林; 黄燕琳

    2012-01-01

    高等学校是我国科技发展的重要力量,加强高等学校的科技成果转化已经成为国家促进科技进步、推动产业升级和经济增长的必经之路。在构建了国家重点建设的西部十四所大学科技成果转化绩效评价体系的基础上,运用数据包络分析法详细考量各高校科技成果转化的绩效,对其技术有效性及规模有效性进行研究后发现,这些高校的科技成果转化整体效率不平衡,主要是纯技术效率和规模效率的无效引起。%The Colleges and Universities is an important force in the development of the science and technology of China. It has been an important way to strengthen the transformation of scientific and technological achievements, promote the upgrade of industry and the economical growth. Based on building the performance evaluation system for transformation of research findings, using the data envelopment analysis, the author evaluated the performance of transformation of research findings in relating colleges and universities, and discussed the technical validity and scale effectiveness. This paper found that technical efficiency of transformation in the western colleges and universities is unbalanced assigned to the invalid pure technical efficiency and invalid scale efficiency.

  5. Implementation for Controller to Unified Single Phase Power Flow Using Digital Signal Processor (DSP-TMS320C31

    Directory of Open Access Journals (Sweden)

    Abdul Aziz Mohammed Al Buaijan,

    2014-08-01

    Full Text Available Presenting in his paper, Digital signal processor (DSP-based implementation of a single phase unified power flow controller (UPFC. For shunt side and series side An efficient UPFC control algorithm is achieved. Discussing the laboratory experimental results using DC source are taken as an UPFC linked by two ll-bridge PWM voltage source converters.

  6. Spatial filtering efficiency of monostatic biaxial lidar: analysis and applications

    Science.gov (United States)

    Agishev, Ravil R.; Comeron, Adolfo

    2002-12-01

    Results of lidar modeling based on spatial-angular filtering efficiency criteria are presented. Their analysis shows that the low spatial-angular filtering efficiency of traditional visible and near-infrared systems is an important cause of low signal/background-radiation ratio (SBR) at the photodetector input. The low SBR may be responsible for considerable measurement errors and ensuing the low accuracy of the retrieval of atmospheric optical parameters. As shown, the most effective protection against sky background radiation for groundbased biaxial lidars is the modifying of their angular field according to a spatial-angular filtering efficiency criterion. Some effective approaches to achieve a high filtering efficiency for the receiving system optimization are discussed.

  7. Learning efficient correlated equilibria

    KAUST Repository

    Borowski, Holly P.

    2014-12-15

    The majority of distributed learning literature focuses on convergence to Nash equilibria. Correlated equilibria, on the other hand, can often characterize more efficient collective behavior than even the best Nash equilibrium. However, there are no existing distributed learning algorithms that converge to specific correlated equilibria. In this paper, we provide one such algorithm which guarantees that the agents\\' collective joint strategy will constitute an efficient correlated equilibrium with high probability. The key to attaining efficient correlated behavior through distributed learning involves incorporating a common random signal into the learning environment.

  8. Achievable Precision for Optical Ranging Systems

    Science.gov (United States)

    Moision, Bruce; Erkmen, Baris I.

    2012-01-01

    Achievable RMS errors in estimating the phase, frequency, and intensity of a direct-detected intensity-modulated optical pulse train are presented. For each parameter, the Cramer-Rao-Bound (CRB) is derived and the performance of the Maximum Likelihood estimator is illustrated. Approximations to the CRBs are provided, enabling an intuitive understanding of estimator behavior as a function of the signaling parameters. The results are compared to achievable RMS errors in estimating the same parameters from a sinusoidal waveform in additive white Gaussian noise. This establishes a framework for a performance comparison of radio frequency (RF) and optical science. Comparisons are made using parameters for state-of-the-art deep-space RF and optical links. Degradations to the achievable errors due to clock phase noise and detector jitter are illustrated.

  9. Finding Signals for Plant Promoters

    Institute of Scientific and Technical Information of China (English)

    Weimou Zheng

    2003-01-01

    The strongest signal of plant promoter is searched with the model of single motif with two types. It turns out that the dominant type is the TATA-box. The other type may be called TATA-less signal, and may be used in gene finders for promoter recognition. While the TATA signals are very close for the monocot and the dicot, their TATA-less signals are significantly different. A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming. By extending the Gibbs sampler to the dynamic programming and introducing temperature, an efficient algorithm is developed for searching signals in plant promoters.

  10. Signaling aggression.

    Science.gov (United States)

    van Staaden, Moira J; Searcy, William A; Hanlon, Roger T

    2011-01-01

    From psychological and sociological standpoints, aggression is regarded as intentional behavior aimed at inflicting pain and manifested by hostility and attacking behaviors. In contrast, biologists define aggression as behavior associated with attack or escalation toward attack, omitting any stipulation about intentions and goals. Certain animal signals are strongly associated with escalation toward attack and have the same function as physical attack in intimidating opponents and winning contests, and ethologists therefore consider them an integral part of aggressive behavior. Aggressive signals have been molded by evolution to make them ever more effective in mediating interactions between the contestants. Early theoretical analyses of aggressive signaling suggested that signals could never be honest about fighting ability or aggressive intentions because weak individuals would exaggerate such signals whenever they were effective in influencing the behavior of opponents. More recent game theory models, however, demonstrate that given the right costs and constraints, aggressive signals are both reliable about strength and intentions and effective in influencing contest outcomes. Here, we review the role of signaling in lieu of physical violence, considering threat displays from an ethological perspective as an adaptive outcome of evolutionary selection pressures. Fighting prowess is conveyed by performance signals whose production is constrained by physical ability and thus limited to just some individuals, whereas aggressive intent is encoded in strategic signals that all signalers are able to produce. We illustrate recent advances in the study of aggressive signaling with case studies of charismatic taxa that employ a range of sensory modalities, viz. visual and chemical signaling in cephalopod behavior, and indicators of aggressive intent in the territorial calls of songbirds.

  11. Ultrahigh bandwidth signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo

    2016-01-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....

  12. Detection of Doppler Microembolic Signals Using High Order Statistics

    Directory of Open Access Journals (Sweden)

    Maroun Geryes

    2016-01-01

    Full Text Available Robust detection of the smallest circulating cerebral microemboli is an efficient way of preventing strokes, which is second cause of mortality worldwide. Transcranial Doppler ultrasound is widely considered the most convenient system for the detection of microemboli. The most common standard detection is achieved through the Doppler energy signal and depends on an empirically set constant threshold. On the other hand, in the past few years, higher order statistics have been an extensive field of research as they represent descriptive statistics that can be used to detect signal outliers. In this study, we propose new types of microembolic detectors based on the windowed calculation of the third moment skewness and fourth moment kurtosis of the energy signal. During energy embolus-free periods the distribution of the energy is not altered and the skewness and kurtosis signals do not exhibit any peak values. In the presence of emboli, the energy distribution is distorted and the skewness and kurtosis signals exhibit peaks, corresponding to the latter emboli. Applied on real signals, the detection of microemboli through the skewness and kurtosis signals outperformed the detection through standard methods. The sensitivities and specificities reached 78% and 91% and 80% and 90% for the skewness and kurtosis detectors, respectively.

  13. EFFICIENT IMPLEMENTATION OF 3D FILTER FOR MOVING OBJECT EXTRACTION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper the design and implementation of Multi-Dimensional (MD) filter, particularly 3-Dimensional (3D) filter, are presented. Digital (discrete domain) filters applied to image and video signal processing using the novel 3D multirate algorithms for efficient implementation of moving object extraction are engineered with an example. The multirate (decimation and/or interpolation) signal processing algorithms can achieve significant savings in computation and memory usage. The proposed algorithm uses the mapping relations of z-transfer functions between non-multirate and multirate mathematical expressions in terms of time-varying coefficient instead of traditional polyphase decomposition counterparts. The mapping properties can be readily used to efficiently analyze and synthesize MD multirate filters.

  14. Attitude Towards Physics and Additional Mathematics Achievement Towards Physics Achievement

    Science.gov (United States)

    Veloo, Arsaythamby; Nor, Rahimah; Khalid, Rozalina

    2015-01-01

    The purpose of this research is to identify the difference in students' attitude towards Physics and Additional Mathematics achievement based on gender and relationship between attitudinal variables towards Physics and Additional Mathematics achievement with achievement in Physics. This research focused on six variables, which is attitude towards…

  15. Digital encoding and detection of voiceband data signals

    Science.gov (United States)

    Koneru, R. R.

    1980-12-01

    The codecs considered for investigation are Pulse Code Modulation (PCM), Differential PCM, and Delta Modulation operating at bit rates from 16 to 64 kb/sec. A central result of this study was the identification and evaluation of sampling phase differential effect present in a digital encoding system when sampling clock is not synchronous with an integral multiple of the data modern bit clock. PSK voiceband data signals are allowed to pass through these codecs that are designed for speech or data input signals. Digital encoders considered for investigation are ranked using the above performance metrics. Performance results of these coders are fully discussed and analyzed. Recognition algorithm for voiceband data, speech, and silence signals is developed for complete automation in digital channel efficiency models to achieve the optimum system performance. Pattern recognition approaches are sought to formulate and solve this problem. Maximum likelihood estimation procedure with recursive implementation of algorithm is developed.

  16. SoC-based architecture for biomedical signal processing.

    Science.gov (United States)

    Gutiérrez-Rivas, R; Hernández, A; García, J J; Marnane, W

    2015-01-01

    Over the last decades, many algorithms have been proposed for processing biomedical signals. Most of these algorithms have been focused on the elimination of noise and artifacts existing in these signals, so they can be used for automatic monitoring and/or diagnosis applications. With regard to remote monitoring, the use of portable devices often requires a reduced number of resources and power consumption, being necessary to reach a trade-off between the accuracy of algorithms and their computational complexity. This paper presents a SoC (System-on-Chip) architecture, based on a FPGA (Field-Programmable Gate Array) device, suitable for the implementation of biomedical signal processing. The proposal has been successfully validated by implementing an efficient QRS complex detector. The results show that, using a reduced amount of resources, values of sensitivity and positive predictive value above 99.49% are achieved, which make the proposed approach suitable for telemedicine applications.

  17. High Efficient Universal Buck Boost Solar Array Regulator SAR Module

    Science.gov (United States)

    Kimmelmann, Stefan; Knorr, Wolfgang

    2014-08-01

    The high efficient universal Buck Boost Solar Array Regulator (SAR) module concept is applicable for a wide range of input and output voltages. The single point failure tolerant SAR module contains 3 power converters for the transfer of the SAR power to the battery dominated power bus. The converters are operating parallel in a 2 out of 3 redundancy and are driven by two different controllers. The output power of one module can be adjusted up to 1KW depending on the requirements. The maximum power point tracker (MPPT) is placed on a separate small printed circuit board and can be used if no external tracker signal is delivered. Depending on the mode and load conditions an efficiency of more than 97% is achievable. The stable control performance is achieved by implementing the magnetic current sense detection. The sensed power coil current is used in Buck and Boost control mode.

  18. Achieving High Performance Perovskite Solar Cells

    Science.gov (United States)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  19. DPAL: historical perspective and summary of achievements

    Science.gov (United States)

    Zhdanov, B. V.; Knize, R. J.

    2013-10-01

    Alkali vapor lasers are under extensive research and development during the past decade because of their potential for scaling to high powers while maintaining a good beam quality. Also, a possibility of using efficient diode lasers for pumping alkali vapor promises high total wall plug efficiency for a Diode Pumped Alkali Laser (DPAL). Since the first DPAL demonstration with output power of 130 mW in 20051, a significant progress in this field was achieved. The output power of about 1 kW in continuous wave (CW) operation with optical efficiency close to 50% was recently demonstrated for a Cs DPAL2. Also, the DPALs based on other alkali metals (Rubidium and Potassium) were demonstrated3,4 . In spite of these significant achievements, there are still several problems in DPAL power scaling exist that must be addressed. Among them are the thermal5 and photoionization6 issues that become important even at power level about several tens of watts. In this paper we present a historical review of the alkali laser research and development, discuss the most important achievements and future perspectives in this field of research.

  20. Parameter estimation of DSSS signals in non-cooperative communication system

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaoming; Zhang Zhongzhao

    2007-01-01

    A new adaptive estimator for direct sequence spread spectrum (DSSS) signals using fourth-order cumulant based adaptive method is considered. The general higher-order statistics may not be easily applied in signal processing with too complex computation. Based on the fourth-order cumulant with 1-D slices and adaptive filters, an efficient algorithm is proposed to solve the problem and is extended for nonstationary stochastic processes. In order to achieve thc accurate parameter estimation of direct sequence spread spectrum (DSSS) signals, the firrst step uses the modified fourth-order cumulant to reduce the computing complexity. While the second step employs an adaptive recursive system to estimate the power spectrum in the frequency domain. In the case of intercepted signals without large enough data samples, the estimator provides good performance in parameter estimation and white Gaussian noise suppression. Computer simulations are included to corroborate the theoretical development with different signal-to-noise ratio conditions and recursive coefficients.

  1. Digital signal processing techniques for coherent optical communication

    Science.gov (United States)

    Goldfarb, Gilad

    Coherent detection with subsequent digital signal processing (DSP) is developed, analyzed theoretically and numerically and experimentally demonstrated in various fiber-optic transmission scenarios. The use of DSP in conjunction with coherent detection unleashes the benefits of coherent detection which rely on the preservaton of full information of the incoming field. These benefits include high receiver sensitivity, the ability to achieve high spectral-efficiency and the use of advanced modulation formats. With the immense advancements in DSP speeds, many of the problems hindering the use of coherent detection in optical transmission systems have been eliminated. Most notably, DSP alleviates the need for hardware phase-locking and polarization tracking, which can now be achieved in the digital domain. The complexity previously associated with coherent detection is hence significantly diminished and coherent detection is once gain considered a feasible detection alternative. In this thesis, several aspects of coherent detection (with or without subsequent DSP) are addressed. Coherent detection is presented as a means to extend the dispersion limit of a duobinary signal using an analog decision-directed phase-lock loop. Analytical bit-error ratio estimation for quadrature phase-shift keying signals is derived. To validate the promise for high spectral efficiency, the orthogonal-wavelength-division multiplexing scheme is suggested. In this scheme the WDM channels are spaced at the symbol rate, thus achieving the spectral efficiency limit. Theory, simulation and experimental results demonstrate the feasibility of this approach. Infinite impulse response filtering is shown to be an efficient alternative to finite impulse response filtering for chromatic dispersion compensation. Theory, design considerations, simulation and experimental results relating to this topic are presented. Interaction between fiber dispersion and nonlinearity remains the last major challenge

  2. Achievable Rate of Spectrum Sharing Cognitive Radio Multiple-Antenna Channels

    KAUST Repository

    Sboui, Lokman

    2015-04-28

    We investigate the spectral efficiency gain of an uplink Cognitive Radio (CR) Multi-Input-Multi-Output system in which the Secondary User (SU) is allowed to share the spectrum with the Primary User (PU) using a specific precoding scheme to communicate with a common receiver. The proposed scheme exploits, at the same time, the free eigenmodes of the primary channel after a space alignment procedure and the interference threshold tolerated by the PU. At the common receiver, we adopt a Successive Interference Cancellation (SIC) technique to eliminate the effect of the detected primary signal transmitted through the exploited eigenmodes. Furthermore, we analyze the SIC operation inaccuracy as well as the CSI estimation imperfection on the PU and SU throughputs. Numerical results show that our proposed scheme enhances considerably the cognitive achievable rate. For instance, in case of a perfect detection of the PU signal, the CR rate remains non-zero for high Signal to Noise Ratio which is usually impossible when we only employ a space alignment technique. We show that a modified water-filling power allocation policy at the PU can increase the secondary rate with a marginal degradation of the primary rate. Finally, we investigate the behavior of the PU and SU rates through the study of the rate achievable region.

  3. Ultrahigh bandwidth signal processing

    Science.gov (United States)

    Oxenløwe, Leif Katsuo

    2016-04-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, and hence useful for all types of data signals including coherent multi-level modulation formats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signals. In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral magnification of the OFDM signal. Utilising such telescopic arrangements, it has become possible to perform a number of interesting functionalities, which will be described in the presentation. This includes conversion from OFDM to Nyquist WDM, compression of WDM channels to a single Nyquist channel and WDM regeneration. These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platforms like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described.

  4. Bayesian signaling

    OpenAIRE

    Hedlund, Jonas

    2014-01-01

    This paper introduces private sender information into a sender-receiver game of Bayesian persuasion with monotonic sender preferences. I derive properties of increasing differences related to the precision of signals and use these to fully characterize the set of equilibria robust to the intuitive criterion. In particular, all such equilibria are either separating, i.e., the sender's choice of signal reveals his private information to the receiver, or fully disclosing, i.e., the outcome of th...

  5. 2-D MULTIRATE ALGORITHMS FOR EFFICIENT IMPLEMENTATION OF EDGE DETECTION

    Institute of Scientific and Technical Information of China (English)

    Chen Ken; Wang Ping

    2005-01-01

    Edge detection is a fundamental issue in image analysis. This paper proposes multirate algorithms for efficient implementation of edge detector, and a design example is illustrated.The multirate (decimation and/or interpolation) signal processing algorithms can achieve considerable savings in computation and storage. The proposed algorithms result in mapping relations of their z-transfer functions between non-multirate and multirate mathematical expressions in terms of time-varying coefficient instead of traditional polyphase decomposition counterparts.The mapping properties can be readily utilized to efficiently analyze and synthesize multirate edge detection filters. The Very high-speed Hardware Description Language (VHDL) simulation results verify efficiency of the algorithms for real-time Field Programmable Gate-Array (FPGA)implementation.

  6. [Weak signal detection in every heart cycle].

    Science.gov (United States)

    Yuan, J; Xu, X; Gao, D; Shi, G

    2001-12-01

    In this article, a new approach is introduced to lowering the myo-electronic noise in weak ECG signals. We use artificial neural network to make the noise be white, and then we adopt an adaptive filter of which the reference signal is achieved by extracting from other ECG cycle. The outcome is the reduction of both white noise and non-white noise in ECG signal. Satisfactory results have been achieved by using this method in the experiment of late potential detection.

  7. MIMO-OFDM signal optimization for SAR imaging radar

    Science.gov (United States)

    Baudais, J.-Y.; Méric, S.; Riché, V.; Pottier, É.

    2016-12-01

    This paper investigates the optimization of the coded orthogonal frequency division multiplexing (OFDM) transmitted signal in a synthetic aperture radar (SAR) context. We propose to design OFDM signals to achieve range ambiguity mitigation. Indeed, range ambiguities are well known to be a limitation for SAR systems which operates with pulsed transmitted signal. The ambiguous reflected signal corresponding to one pulse is then detected when the radar has already transmitted the next pulse. In this paper, we demonstrate that the range ambiguity mitigation is possible by using orthogonal transmitted wave as OFDM pulses. The coded OFDM signal is optimized through genetic optimization procedures based on radar image quality parameters. Moreover, we propose to design a multiple-input multiple-output (MIMO) configuration to enhance the noise robustness of a radar system and this configuration is mainly efficient in the case of using orthogonal waves as OFDM pulses. The results we obtain show that OFDM signals outperform conventional radar chirps for range ambiguity suppression and for robustness enhancement in 2 ×2 MIMO configuration.

  8. Wideband Array Signal Detection Algorithm Based on Power Focusing

    Directory of Open Access Journals (Sweden)

    Gong Bin

    2012-09-01

    Full Text Available Aiming at the requirement of real-time signal detection in the passive surveillance system, a wideband array signal detection algorithm is proposed based on the concept of power focusing. By making use of the phase difference of the signal received by a uniform linear array, the algorithm makes the power of the received signal focused in the Direction Of Arrival (DOA with improved cascade FFT. Subsequently, the probability density function of the output noise at each angle is derived. Furthermore, a Constant False Alarm Rate (CFAR test statistic and the corresponding detection threshold are constructed. The theoretical probability of detection is also derived for different false alarm rate and Signal-to-Noise Ratio (SNR. The proposed algorithm is computationally efficient, and the detection process is independent of the prior information. Meanwhile, the results can act as the initial value for other algorithms with higher precision. Simulation results show that the proposed algorithm achieves good performance for weak signal detection.

  9. Efficient and Compact Optical Amplifier Using EYDF

    Directory of Open Access Journals (Sweden)

    Sulaiman Wadi Harun

    2010-09-01

    Full Text Available An efficient Erbium/Ytterbium doped fiber amplifier (EYDFA is demonstrated using a 1058nm pumping wavelength, where the amplification is assisted by energy transfer between Yb and Er ions. The energy transfer increases the limit of erbium doping concentration that is imposed by concentration quenching in Erbium-doped fiber (EDF. Therefore, the gain and noise figure are severely degraded with 1480 nm pumping, where the energy transfer cannot be achieved. The use of optical isolator improves the small signal gain and noise figure by about 4.8 dB and 1.6 dB, respectively. By employing a double-pass configuration, a higher gain can be obtained with an expense of a noise figure penalty. The gain improvement of 17.0 dB is obtained at 20 mW and -50 dBm of pump and input signal powers. This shows that the double-pass configuration is an important aspect to consider when designing an efficient EYDFA.

  10. A mixed transform approach for efficient compression of medical images.

    Science.gov (United States)

    Ramaswamy, A; Mikhael, W B

    1996-01-01

    A novel technique is presented to compress medical data employing two or more mutually nonorthogonal transforms. Both lossy and lossless compression implementations are considered. The signal is first resolved into subsignals such that each subsignal is compactly represented in a particular transform domain. An efficient lossy representation of the signal is achieved by superimposing the dominant coefficients corresponding to each subsignal. The residual error, which is the difference between the original signal and the reconstructed signal is properly formulated. Adaptive algorithms in conjunction with an optimization strategy are developed to minimize this error. Both two-dimensional (2-D) and three-dimensional (3-D) approaches for the technique are developed. It is shown that for a given number of retained coefficients, the discrete cosine transform (DCT)-Walsh mixed transform representation yields a more compact representation than using DCT or Walsh alone. This lossy technique is further extended for the lossless case. The coefficients are quantized and the signal is reconstructed. The resulting reconstructed signal samples are rounded to the nearest integer and the modified residual error is computed. This error is transmitted employing a lossless technique such as the Huffman coding. It is shown that for a given number of retained coefficients, the mixed transforms again produces the smaller rms-modified residual error. The first-order entropy of the error is also smaller for the mixed-transforms technique than for the DCT, thus resulting in smaller length Huffman codes.

  11. Signal localization: a new approach in signal discovery.

    Science.gov (United States)

    Malov, Sergey V; Antonik, Alexey; Tang, Minzhong; Berred, Alexandre; Zeng, Yi; O'Brien, Stephen J

    2017-01-01

    A new approach for statistical association signal identification is developed in this paper. We consider a strategy for nonprecise signal identification by extending the well-known signal detection and signal identification methods applicable to the multiple testing problem. Collection of statistical instruments under the presented approach is much broader than under the traditional signal identification methods, allowing more efficient signal discovery. Further assessments of maximal value and average statistics in signal discovery are improved. While our method does not attempt to detect individual predictors, it instead detects sets of predictors that are jointly associated with the outcome. Therefore, an important application would be in genome wide association study (GWAS), where it can be used to detect genes which influence the phenotype but do not contain any individually significant single nucleotide polymorphism (SNP). We compare power of the signal identification method based on extremes of single p-values with the signal localization method based on average statistics for logarithms of p-values. A simulation analysis informs the application of signal localization using the average statistics for wide signals discovery in Gaussian white noise process. We apply average statistics and the localization method to GWAS to discover better gene influences of regulating loci in a Chinese cohort developed for risk of nasopharyngeal carcinoma (NPC).

  12. Mathematics Achievement in High- and Low-Achieving Secondary Schools

    Science.gov (United States)

    Mohammadpour, Ebrahim; Shekarchizadeh, Ahmadreza

    2015-01-01

    This paper identifies the amount of variance in mathematics achievement in high- and low-achieving schools that can be explained by school-level factors, while controlling for student-level factors. The data were obtained from 2679 Iranian eighth graders who participated in the 2007 Trends in International Mathematics and Science Study. Of the…

  13. Efficient power combiner for THz radiation

    Directory of Open Access Journals (Sweden)

    Hamide Seidfaraji

    2016-08-01

    Full Text Available Most dangerous explosive materials, both toxic and radioactive, contain nitrogen salts with resonant absorption lines in the frequency range 0.3-10 THz. Therefore, there has been growing interest in remotely detecting such materials by observing the spectrum of reflected signals when the suspicious material is interrogated by THz radiation. Practical portable THz sources available today generate only 20–40 mW output power. This power level is too low to interrogate suspicious material from a safe distance, especially if the material is concealed. Hence, there is a need for sources that can provide greater power in the THz spectrum. Generating and extracting high output power from THz sources is complicated and inefficient. The efficiency of vacuum electronic microwave sources is very low when scaled to the THz range and THz sources based on scaling down semiconductor laser sources have low efficiency as well, resulting in the well known “THz gap.” The reason for such low efficiencies for both source types is material losses in the THz band. In this article an efficient power combiner is described that is based on scaling to higher frequencies a microwave combiner that increases the output power in the THz range of interest in simulation studies. The proposed power combiner not only combines the THz power output from several sources, but can also form a Gaussian wavebeam output. A minimum conversion efficiency of 89% with cophased inputs in a lossy copper power combiner and maximum efficiency of 100% in a Perfect Electric Conductor (PEC-made power combiner were achieved in simulations. Also, it is shown that the TE01 output mode is a reasonable option for THz applications due to the fact that conductive loss decreases for this mode as frequency increases.

  14. [A fractal denoising method for astronomical spectral signal].

    Science.gov (United States)

    Han, Jin-shu; Luo, A-li; Zhao, Yong-heng

    2011-12-01

    To restore the continuum and the spectral lines from a noisy astronomical spectrum, then to measure the equivalent widths of the spectral lines, the fractal denoising method was firstly used in astronomical spectra in the present paper. The method is based on the distinguishing features, that is the local self-similarities exist in an astronomical spectrum, while not in a random white noise signal. The experimental results show that the fractal denoising method is efficient in parameter measurements, such as equivalent widths for spectral lines, redshift of galaxies, and so on. In addition, the method can achieve data compression. The fractal method can be used in the mass spectra of LAMOST.

  15. Sensor-Based Vibration Signal Feature Extraction Using an Improved Composite Dictionary Matching Pursuit Algorithm

    Directory of Open Access Journals (Sweden)

    Lingli Cui

    2014-09-01

    Full Text Available This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and

  16. Sensor-based vibration signal feature extraction using an improved composite dictionary matching pursuit algorithm.

    Science.gov (United States)

    Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

    2014-09-09

    This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm

  17. Efficient parametric interactions in a low loss GaInP photonic crystal waveguide.

    Science.gov (United States)

    Cestier, I; Willinger, A; Colman, P; Combrié, S; Lehoucq, G; De Rossi, A; Eisenstein, G

    2011-10-01

    We describe time domain characterizations of dynamic four-wave mixing in a low loss modified W1 GaInP photonic crystal waveguide. Using 32 ps wide pump pulses with peak powers of up to 1.1 W we achieved a very large conversion efficiency of -6.8 dB as well as a 1.3 dB parametric gain experienced by a weak CW probe signal. Time domain simulations confirm quantitatively all the measured results.

  18. Design of a High Efficiency Boost DC-DC Converter

    Institute of Scientific and Technical Information of China (English)

    GAO Jing; YAO Suying; XU Jiangtao; SHI Zaifeng

    2009-01-01

    An accurate circuit of PWM/PFM mode converting and a circuit of auto-adaptively adjusting dimension of power transistor are described. The duty cycle of the signal when the control mode converts can be gained accu-rately by using ratios of currents and capacitances, and an optimal dimension of power transistor is derived with different loads. The converter is designed by 0.35 μm standard CMOS technology. Simulation results indicate that the converter starts work at 0.8 V input voltage. Combined with synchronized rectification, the transfer efficiency is higher than 90% with full load range, and achieves 97.5% at rating output.

  19. Peer relationships and academic achievement

    Directory of Open Access Journals (Sweden)

    Krnjajić Stevan B.

    2002-01-01

    Full Text Available After their childhood, when children begin to establish more intensive social contacts outside family, first of all, in school setting, their behavior i.e. their social, intellectual, moral and emotional development is more strongly affected by their peers. Consequently, the quality of peer relationships considerably affects the process of adaptation and academic achievement and their motivational and emotional attitude towards school respectively. Empirical findings showed that there is bi-directional influence between peer relationships and academic achievement. In other words, the quality of peer relationships affects academic achievement, and conversely, academic achievement affects the quality of peer relationships. For example, socially accepted children exhibiting prosocial, cooperative and responsible forms of behavior in school most frequently have high academic achievement. On the other hand, children rejected by their peers often have lower academic achievement and are a risk group tending to delinquency, absenteeism and drop out of school. Those behavioral and interpersonal forms of competence are frequently more reliable predictors of academic achievement than intellectual abilities are. Considering the fact that various patterns of peer interaction differently exert influence on students' academic behavior, the paper analyzed effects of (a social competence, (b social acceptance/rejection, (c child's friendships and (d prosocial behavior on academic achievement.

  20. Healthy Eating and Academic Achievement

    Centers for Disease Control (CDC) Podcasts

    2014-12-09

    This podcast highlights the evidence that supports the link between healthy eating and improved academic achievement. It also identifies a few actions to support a healthy school nutrition environment to improve academic achievement.  Created: 12/9/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 12/9/2014.

  1. Physical Activity and Academic Achievement

    Centers for Disease Control (CDC) Podcasts

    2014-12-09

    This podcast highlights the evidence that supports the link between physical activity and improved academic achievement. It also identifies a few actions to support a comprehensive school physical activity program to improve academic achievement.  Created: 12/9/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 12/9/2014.

  2. Sociocultural Origins of Achievement Motivation

    Science.gov (United States)

    Maehr, Martin L.

    1977-01-01

    Presents a theoretical review of work on sociocultural influences on achievement, focusing on a critical evaluation of the work of David McClellan. Offers an alternative conception of achievement motivation which stresses the role of contextual and situational factors in addition to personality factors. Available from: Transaction Periodicals…

  3. Parental Involvement and Academic Achievement

    Science.gov (United States)

    Goodwin, Sarah Christine

    2015-01-01

    This research study examined the correlation between student achievement and parent's perceptions of their involvement in their child's schooling. Parent participants completed the Parent Involvement Project Parent Questionnaire. Results slightly indicated parents of students with higher level of achievement perceived less demand or invitations…

  4. Efficient Wideband Spectrum Sensing with Maximal Spectral Efficiency for LEO Mobile Satellite Systems

    Directory of Open Access Journals (Sweden)

    Feilong Li

    2017-01-01

    Full Text Available The usable satellite spectrum is becoming scarce due to static spectrum allocation policies. Cognitive radio approaches have already demonstrated their potential towards spectral efficiency for providing more spectrum access opportunities to secondary user (SU with sufficient protection to licensed primary user (PU. Hence, recent scientific literature has been focused on the tradeoff between spectrum reuse and PU protection within narrowband spectrum sensing (SS in terrestrial wireless sensing networks. However, those narrowband SS techniques investigated in the context of terrestrial CR may not be applicable for detecting wideband satellite signals. In this paper, we mainly investigate the problem of joint designing sensing time and hard fusion scheme to maximize SU spectral efficiency in the scenario of low earth orbit (LEO mobile satellite services based on wideband spectrum sensing. Compressed detection model is established to prove that there indeed exists one optimal sensing time achieving maximal spectral efficiency. Moreover, we propose novel wideband cooperative spectrum sensing (CSS framework where each SU reporting duration can be utilized for its following SU sensing. The sensing performance benefits from the novel CSS framework because the equivalent sensing time is extended by making full use of reporting slot. Furthermore, in respect of time-varying channel, the spatiotemporal CSS (ST-CSS is presented to attain space and time diversity gain simultaneously under hard decision fusion rule. Computer simulations show that the optimal sensing settings algorithm of joint optimization of sensing time, hard fusion rule and scheduling strategy achieves significant improvement in spectral efficiency. Additionally, the novel ST-CSS scheme performs much higher spectral efficiency than that of general CSS framework.

  5. Efficient Wideband Spectrum Sensing with Maximal Spectral Efficiency for LEO Mobile Satellite Systems

    Science.gov (United States)

    Li, Feilong; Li, Zhiqiang; Li, Guangxia; Dong, Feihong; Zhang, Wei

    2017-01-01

    The usable satellite spectrum is becoming scarce due to static spectrum allocation policies. Cognitive radio approaches have already demonstrated their potential towards spectral efficiency for providing more spectrum access opportunities to secondary user (SU) with sufficient protection to licensed primary user (PU). Hence, recent scientific literature has been focused on the tradeoff between spectrum reuse and PU protection within narrowband spectrum sensing (SS) in terrestrial wireless sensing networks. However, those narrowband SS techniques investigated in the context of terrestrial CR may not be applicable for detecting wideband satellite signals. In this paper, we mainly investigate the problem of joint designing sensing time and hard fusion scheme to maximize SU spectral efficiency in the scenario of low earth orbit (LEO) mobile satellite services based on wideband spectrum sensing. Compressed detection model is established to prove that there indeed exists one optimal sensing time achieving maximal spectral efficiency. Moreover, we propose novel wideband cooperative spectrum sensing (CSS) framework where each SU reporting duration can be utilized for its following SU sensing. The sensing performance benefits from the novel CSS framework because the equivalent sensing time is extended by making full use of reporting slot. Furthermore, in respect of time-varying channel, the spatiotemporal CSS (ST-CSS) is presented to attain space and time diversity gain simultaneously under hard decision fusion rule. Computer simulations show that the optimal sensing settings algorithm of joint optimization of sensing time, hard fusion rule and scheduling strategy achieves significant improvement in spectral efficiency. Additionally, the novel ST-CSS scheme performs much higher spectral efficiency than that of general CSS framework. PMID:28117712

  6. Juggling Efficiency

    DEFF Research Database (Denmark)

    Andersen, Rikke Sand; Vedsted, Peter

    2015-01-01

    on institutional logics, we illustrate how a logic of efficiency organise and give shape to healthcare seeking practices as they manifest in local clinical settings. Overall, patient concerns are reconfigured to fit the local clinical setting and healthcare professionals and patients are required to juggle...... efficiency in order to deal with uncertainties and meet more complex or unpredictable needs. Lastly, building on the empirical case of cancer diagnostics, we discuss the implications of the pervasiveness of the logic of efficiency in the clinical setting and argue that provision of medical care in today......'s primary care settings requires careful balancing of increasing demands of efficiency, greater complexity of biomedical knowledge and consideration for individual patient needs....

  7. Bandwidth efficient coding

    CERN Document Server

    Anderson, John B

    2017-01-01

    Bandwidth Efficient Coding addresses the major challenge in communication engineering today: how to communicate more bits of information in the same radio spectrum. Energy and bandwidth are needed to transmit bits, and bandwidth affects capacity the most. Methods have been developed that are ten times as energy efficient at a given bandwidth consumption as simple methods. These employ signals with very complex patterns and are called "coding" solutions. The book begins with classical theory before introducing new techniques that combine older methods of error correction coding and radio transmission in order to create narrowband methods that are as efficient in both spectrum and energy as nature allows. Other topics covered include modulation techniques such as CPM, coded QAM and pulse design.

  8. Efficient Quantum Key Distribution

    CERN Document Server

    Ardehali, M; Chau, H F; Lo, H K

    1998-01-01

    We devise a simple modification that essentially doubles the efficiency of a well-known quantum key distribution scheme proposed by Bennett and Brassard (BB84). Our scheme assigns significantly different probabilities for the different polarization bases during both transmission and reception to reduce the fraction of discarded data. The actual probabilities used in the scheme are announced in public. As the number of transmitted signals increases, the efficiency of our scheme can be made to approach 100%. The security of our scheme (against single-photon eavesdropping strategies) is guaranteed by a refined analysis of accepted data which is employed to detect eavesdropping: Instead of lumping all the accepted data together to estimate a single error rate, we separate the accepted data into various subsets according to the basis employed and estimate an error rate for each subset individually. Our scheme is the first quantum key distribution with an efficiency greater than 50%. We remark that our idea is rath...

  9. Wavelet analysis to decompose a vibration simulation signal to improve pre-distribution testing of packaging

    Science.gov (United States)

    Griffiths, K. R.; Hicks, B. J.; Keogh, P. S.; Shires, D.

    2016-08-01

    In general, vehicle vibration is non-stationary and has a non-Gaussian probability distribution; yet existing testing methods for packaging design employ Gaussian distributions to represent vibration induced by road profiles. This frequently results in over-testing and/or over-design of the packaging to meet a specification and correspondingly leads to wasteful packaging and product waste, which represent 15bn per year in the USA and €3bn per year in the EU. The purpose of the paper is to enable a measured non-stationary acceleration signal to be replaced by a constructed signal that includes as far as possible any non-stationary characteristics from the original signal. The constructed signal consists of a concatenation of decomposed shorter duration signals, each having its own kurtosis level. Wavelet analysis is used for the decomposition process into inner and outlier signal components. The constructed signal has a similar PSD to the original signal, without incurring excessive acceleration levels. This allows an improved and more representative simulated input signal to be generated that can be used on the current generation of shaker tables. The wavelet decomposition method is also demonstrated experimentally through two correlation studies. It is shown that significant improvements over current international standards for packaging testing are achievable; hence the potential for more efficient packaging system design is possible.

  10. Emotional stress recognition using a new fusion link between electroencephalogram and peripheral signals

    Directory of Open Access Journals (Sweden)

    Seyyed Abed Hosseini

    2015-10-01

    Full Text Available Background: This paper proposes a new emotional stress assessment system using multi-modal bio-signals. Electroencephalogram (EEG is the reflection of brain activity and is widely used in clinical diagnosis and biomedical research.Methods: We design an efficient acquisition protocol to acquire the EEG signals in five channels (FP1, FP2, T3, T4 and Pz and peripheral signals such as blood volume pulse, skin conductance (SC and respiration, under images induction (calm-neutral and negatively excited for the participants. The visual stimuli images are selected from the subset International Affective Picture System database. The qualitative and quantitative evaluation of peripheral signals are used to select suitable segments of EEG signals for improving the accuracy of signal labeling according to emotional stress states. After pre-processing, wavelet coefficients, fractal dimension, and Lempel-Ziv complexity are used to extract the features of the EEG signals. The vast number of features leads to the problem of dimensionality, which is solved using the genetic algorithm as a feature selection method.Results: The results show that the average classification accuracy is 89.6% for two categories of emotional stress states using the support vector machine (SVM.Conclusion: This is a great improvement in results compared to other similar researches. We achieve a noticeable improvement of 11.3% in accuracy using SVM classifier, in compared to previous studies. Therefore, a new fusion between EEG and peripheral signals are more robust in comparison to the separate signals.

  11. AREA EFFICIENT DISTRIBUTED ARITHMETIC DISCRETE COSINE TRANSFORM USING MODIFIED WALLACE TREE MULTIPLIER

    Directory of Open Access Journals (Sweden)

    R. P. Meenaakshi Sundari

    2014-01-01

    Full Text Available In this study by using the modified Wallace tree multiplier, an error compensated adder tree is constructed in order to round off truncation errors and to obtain high through put discrete cosine transform design. Peak Signal to Noise Ratio (PSNR is met efficiently since modified Wallace Tree method is an efficient, hardware implementable digital circuit that multiplies two integers resulting an output with reduced delays and errors. Nearly 6% of delays and around 1% of gate counts are reduced. The number of look up tables consumed is 2% lesser than that of the previous multipliers. Thus an area efficient discrete cosine transform is built to achieve high throughput with minimum gate counts and delays for the required Peak Signal to Noise Ratio when compared to the existing DCT’s.

  12. A fast and accurate frequency estimation algorithm for sinusoidal signal with harmonic components

    Science.gov (United States)

    Hu, Jinghua; Pan, Mengchun; Zeng, Zhidun; Hu, Jiafei; Chen, Dixiang; Tian, Wugang; Zhao, Jianqiang; Du, Qingfa

    2016-10-01

    Frequency estimation is a fundamental problem in many applications, such as traditional vibration measurement, power system supervision, and microelectromechanical system sensors control. In this paper, a fast and accurate frequency estimation algorithm is proposed to deal with low efficiency problem in traditional methods. The proposed algorithm consists of coarse and fine frequency estimation steps, and we demonstrate that it is more efficient than conventional searching methods to achieve coarse frequency estimation (location peak of FFT amplitude) by applying modified zero-crossing technique. Thus, the proposed estimation algorithm requires less hardware and software sources and can achieve even higher efficiency when the experimental data increase. Experimental results with modulated magnetic signal show that the root mean square error of frequency estimation is below 0.032 Hz with the proposed algorithm, which has lower computational complexity and better global performance than conventional frequency estimation methods.

  13. Seizure classification in EEG signals utilizing Hilbert-Huang transform

    Directory of Open Access Journals (Sweden)

    Abdulhay Enas W

    2011-05-01

    Full Text Available Abstract Background Classification method capable of recognizing abnormal activities of the brain functionality are either brain imaging or brain signal analysis. The abnormal activity of interest in this study is characterized by a disturbance caused by changes in neuronal electrochemical activity that results in abnormal synchronous discharges. The method aims at helping physicians discriminate between healthy and seizure electroencephalographic (EEG signals. Method Discrimination in this work is achieved by analyzing EEG signals obtained from freely accessible databases. MATLAB has been used to implement and test the proposed classification algorithm. The analysis in question presents a classification of normal and ictal activities using a feature relied on Hilbert-Huang Transform. Through this method, information related to the intrinsic functions contained in the EEG signal has been extracted to track the local amplitude and the frequency of the signal. Based on this local information, weighted frequencies are calculated and a comparison between ictal and seizure-free determinant intrinsic functions is then performed. Methods of comparison used are the t-test and the Euclidean clustering. Results The t-test results in a P-value Conclusion An original tool for EEG signal processing giving physicians the possibility to diagnose brain functionality abnormalities is presented in this paper. The proposed system bears the potential of providing several credible benefits such as fast diagnosis, high accuracy, good sensitivity and specificity, time saving and user friendly. Furthermore, the classification of mode mixing can be achieved using the extracted instantaneous information of every IMF, but it would be most likely a hard task if only the average value is used. Extra benefits of this proposed system include low cost, and ease of interface. All of that indicate the usefulness of the tool and its use as an efficient diagnostic tool.

  14. Batch efficiency

    CERN Document Server

    Schwickerath, U; Uria, C; CERN. Geneva. IT Department

    2010-01-01

    A frequent source of concern for resource providers is the efficient use of computing resources in their centers. This has a direct impact on requests for new resources. There are two different but strongly correlated aspects to be considered: while users are mostly interested in a good turn-around time for their jobs, resource providers are mostly interested in a high and efficient usage of their available resources. Both things, the box usage and the efficiency of individual user jobs, need to be closely monitored so that the sources of the inefficiencies can be identified. At CERN, the Lemon monitoring system is used for both purposes. Examples of such sources are poorly written user code, inefficient access to mass storage systems, and dedication of resources to specific user groups. As a first step for improvements CERN has launched a project to develop a scheduler add-on that allows careful overloading of worker nodes that run idle jobs.

  15. Batch efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Schwickerath, Ulrich; Silva, Ricardo; Uria, Christian, E-mail: Ulrich.Schwickerath@cern.c, E-mail: Ricardo.Silva@cern.c [CERN IT, 1211 Geneve 23 (Switzerland)

    2010-04-01

    A frequent source of concern for resource providers is the efficient use of computing resources in their centers. This has a direct impact on requests for new resources. There are two different but strongly correlated aspects to be considered: while users are mostly interested in a good turn-around time for their jobs, resource providers are mostly interested in a high and efficient usage of their available resources. Both things, the box usage and the efficiency of individual user jobs, need to be closely monitored so that the sources of the inefficiencies can be identified. At CERN, the Lemon monitoring system is used for both purposes. Examples of such sources are poorly written user code, inefficient access to mass storage systems, and dedication of resources to specific user groups. As a first step for improvements CERN has launched a project to develop a scheduler add-on that allows careful overloading of worker nodes that run idle jobs.

  16. Efficiency of charged-particle identification by measurement of energy release in thick scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Vlasov, A.V.; Gavrilov, V.B.; Degtyarenko, P.V.; Doroshkevich, E.A.; Efremenko, Yu.V.; Stavinskii, A.V.; Khasanov, F.M.; Shvartsman, B.B.; Shuvalov, S.M.

    It is shown that, when charged particles are identified by measuring their energy release in a thick scintillator, to achieve high accuracy, it is insufficient to determine efficiency by calculating the probability of interaction of a particle during its deceleration. It is also necessary to take into account the shape of the amplitude distribution of the signals from the scintillation counter and, in the process of identification, to place constraints on their amplitude. Corrections are made for the efficiency of identification of protons, deuterons, tritium, and /sup 3/He ions with various energies that can be used in various experiments.

  17. Longitudinal RF capture simulation and BPM signal estimation

    CERN Document Server

    Feng, Yong-Chun; Chen, Yu-Cong; Yin, Yan; Zhang, Xiao-Hu; Ruan, Shuang; Liu, Tong; You, Yao-Yao; Kang, Xin-Cai; Zhao, Tie-Cheng; Xu, Zhi-Guo; Li, Peng; Wang, Yan-Yu; Yuan, You-Jin

    2016-01-01

    In this paper, the theoretical aspects behind longitudinal RF capture are reviewed and the capture process is simulated via a program based on this theory. Four kinds of cases with different initial distribution and capture curve are considered, i.e. uniform distribution with adiabatic capture, uniform distribution with non-adiabatic capture, Gaussian distribution with adiabatic capture and Gaussian distribution with non-adiabatic capture. The simulation results are compared each other and discussed, and Gaussian distribution with adiabatic capture is demonstrated having a higher capture efficiency and leading to a shorter bunch length. In addition, the BPM induced signal is simulated with high input impendence, i.e. $1M\\Omega$, and low input impendence, i.e. $50\\Omega$, respectively. Finally, the BPM signal of Heavy Ion Medical Machine (HIMM) is estimated and compared with measured one, and a good agreement is achieved.

  18. Achievement report for fiscal 1998 on area consortium research and development business. Area consortium for venture business development by building base for small business (high-efficiency superhigh-accuracy grinding technology by nano-scale in-process measurement and control using novel grinding wheel); 1998 nendo venture kigyo ikuseigata chiiki consortium kenkyu kaihatsu (chusho kigyo sozo kibangata). Shingata kensaku toishi wo mochiita nano in-process keisoku seigyo ni yoru konoritsu choseimitsu kensaku kako gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The aim is to develop a superflat grinding system for functional devices such as hard disks and magnetic heads. Cast iron powder is used as bonding material high in reacting with diamond for an increase in the anchoring power. A chemical reaction occurs to realize a strong bond between the two, producing a precision grinding wheel long in life and high in efficiency. A wheel with some hollows is also developed in which the grits have to bear more load because of the hollows, this achieving grinding efficiency five times higher than that of other types of the same grit size. A system is developed, provided with a constant pressure mechanism for the grinding direction and constant travel mechanism normal to the work surface. Using the constant pressure system, the grinding speed depends on the wheel grinding capability, and then the wheel is allowed to exhibits its best. The system suffers less clogging than the conventional ones. The specific grinding energy which is the index of the match between the wheel and the work may be determined, and this enables prompt condition optimization. It is proved that the wheel with hollows is remarkably higher in grinding capability than wheels of the same grit size on the market. The two are found to be alike in achieving top-class finish in terms of surface coarseness and flatness. (NEDO)

  19. Information efficiency in visual communication

    Science.gov (United States)

    Alter-Gartenberg, Rachel; Rahman, Zia-Ur

    1993-01-01

    This paper evaluates the quantization process in the context of the end-to-end performance of the visual-communication channel. Results show that the trade-off between data transmission and visual quality revolves around the information in the acquired signal, not around its energy. Improved information efficiency is gained by frequency dependent quantization that maintains the information capacity of the channel and reduces the entropy of the encoded signal. Restorations with energy bit-allocation lose both in sharpness and clarity relative to restorations with information bit-allocation. Thus, quantization with information bit-allocation is preferred for high information efficiency and visual quality in optimized visual communication.

  20. Achievable rate of cognitive radio spectrum sharing MIMO channel with space alignment and interference temperature precoding

    KAUST Repository

    Sboui, Lokman

    2013-06-01

    In this paper, we investigate the spectral efficiency gain of an uplink Cognitive Radio (CR) Multi-Input MultiOutput (MIMO) system in which the Secondary/unlicensed User (SU) is allowed to share the spectrum with the Primary/licensed User (PU) using a specific precoding scheme to communicate with a common receiver. The proposed scheme exploits at the same time the free eigenmodes of the primary channel after a space alignment procedure and the interference threshold tolerated by the PU. In our work, we study the maximum achievable rate of the CR node after deriving an optimal power allocation with respect to an outage interference and an average power constraints. We, then, study a protection protocol that considers a fixed interference threshold. Applied to Rayleigh fading channels, we show, through numerical results, that our proposed scheme enhances considerably the cognitive achievable rate. For instance, in case of a perfect detection of the PU signal, after applying Successive Interference Cancellation (SIC), the CR rate remains non-zero for high Signal to Noise Ratio (SNR) which is usually impossible when we only use space alignment technique. In addition, we show that the rate gain is proportional to the allowed interference threshold by providing a fixed rate even in the high SNR range. © 2013 IEEE.

  1. Fining Signals for Plant Promoters

    Institute of Scientific and Technical Information of China (English)

    WeimouZheng

    2003-01-01

    The strongest signal of plant promoter is searched with the model of single motif with two types.It turns out that the dominant type is the TATA-box.The other type may be called TATA-less signal,and may be used in gene finders for promoter recognition.While the TATA signals are very close for the monocot and the dicot,their TATA-less signals are significantly different.A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming.By extending the Gibbs sampler to the dynamic programming and introducing temperature,an efficient algorithm is developed for searching signals in plant promoters.

  2. Performance Analysis for Multichannel Reception of OOFSK Signaling

    CERN Document Server

    Wang, Qingyun

    2007-01-01

    In this paper, the error performance of on-off frequency shift keying (OOFSK) modulation over fading channels is analyzed when the receiver is equipped with multiple antennas. The analysis is conducted in two cases: the coherent scenario where the fading is perfectly known at the receiver, and the noncoherent scenario where neither the receiver nor the transmitter knows the fading coefficients. For both cases, the maximum a posteriori probability (MAP) detection rule is derived and analytical probability of error expressions are obtained. The effect of fading correlation among the receiver antennas is also studied. Simulation results indicate that for sufficiently low duty cycle values, lower probability of error values with respect to FSK signaling are achieved. Equivalently, when compared to FSK modulation, OOFSK with low duty cycle requires less energy to achieve the same probability of error, which renders this modulation a more energy efficient transmission technique.

  3. Signal Processing

    Science.gov (United States)

    1989-03-01

    34ESPIRIT Estimation of signal parameters via rotational imvariance techin+I,-- 1\\I111;1 Smith. A. Faradani "Local and ( Moba ! tomography" I’ Nitlerer and...Feb 1 - Jul 30 Friedman, Avner IMA Gader, Paul University of Wisconsin Jun 27 - Jul 24 Games , Richard MITRE Corp Jun 27 - Aug 5 Garvan, Francis U. of...Gader, Paul University of Wisconsin Jun 27 - Jul 24 Games , Richard MITRE Corp Jun 27 - Aug 5 Garvan, Francis U. of Wisconsin Jun 26 - Jul 31 Habsieger

  4. Disciplinary climate and student achievement

    DEFF Research Database (Denmark)

    Sortkær, Bent; Reimer, David

    Disciplinary climate has emerged as one of the single most important factors related to student achievement. Using data from the OECD Programme for International Student Assessment (PISA) 2003 for Canada, Denmark, Finland, Iceland, Latvia and Norway we find a significant and nontrivial association...... between the perceived disciplinary climate in the classroom and students’ mathematics performance in Canada, Denmark and Norway. Furthermore we exploit country specific class-size rules in order to single out a subsample with classroom-level data (PISA is sampled by age and not by classes) and find...... that the estimates based on school-level data might underestimate the relationship between disciplinary climate and student achievement. Finally we find evidence for gender differences in the association between disciplinary climate and student achievement that can partly be explained by gender-specific perceptions...

  5. Mathematics Achievement by Immigrant Children

    Directory of Open Access Journals (Sweden)

    Gary G. Huang

    2000-05-01

    Full Text Available In this study, I examined academic achievement of immigrant children in the United States, Canada, England, Australia, and New Zealand. Analyzing data from the Third International Mathematics and Science Study (TIMSS, I gauged the performance gaps relating to the generation of immigration and the home language background. I found immigrant children's math and science achievement to be lower than the others only in England, the U.S., and Canada. Non-English language background was found in each country to relate to poor math and science learning and this disadvantage was stronger among native-born children—presumably children of indigenous groups—than among immigrant children. I also examined the school variation in math performance gaps, using hierarchical linear modeling (HLM to each country's data. The patterns in which language- and generation-related math achievement gaps varied between schools are different in the five countries.

  6. Self-organization of signal transduction [v1; ref status: indexed, http://f1000r.es/zg

    Directory of Open Access Journals (Sweden)

    Gabriele Scheler

    2013-04-01

    Full Text Available We propose a model of parameter learning for signal transduction, where the objective function is defined by signal transmission efficiency. We apply this to learn kinetic rates as a form of evolutionary learning, and look for parameters which satisfy the objective. This is a novel approach compared to the usual technique of adjusting parameters only on the basis of experimental data. The resulting model is self-organizing, i.e. perturbations in protein concentrations or changes in extracellular signaling will automatically lead to adaptation. We systematically perturb protein concentrations and observe the response of the system. We find compensatory or co-regulation of protein expression levels. In a novel experiment, we alter the distribution of extracellular signaling, and observe adaptation based on optimizing signal transmission. We also discuss the relationship between signaling with and without transients. Signaling by transients may involve maximization of signal transmission efficiency for the peak response, but a minimization in steady-state responses. With an appropriate objective function, this can also be achieved by concentration adjustment. Self-organizing systems may be predictive of unwanted drug interference effects, since they aim to mimic complex cellular adaptation in a unified way.

  7. QRS complex detection in ECG signal for wearable devices.

    Science.gov (United States)

    Arefin, M Riadh; Tavakolian, Kouhyar; Fazel-Rezai, Reza

    2015-01-01

    This paper presents QRS complex detection algorithm based on dual slope technique, which is suitable for wearable electrocardiogram (ECG) applications. For cardiac patients of different arrhythmias, ECG signals are needed to be monitored over an extensive period of time. Thus, the wearable heart monitoring system needs computationally efficient QRS detection technique with good accuracy. In this paper, a method of QRS detection based on two slopes on both sides of an R peak is presented which is computationally efficient. Based on the slopes, first, a variable measuring steepness is developed, then by introducing an adjustable R-R interval based window and adaptive thresholding techniques, depending on the number of peaks detected in such window, R peaks are detected. The algorithm was evaluated against MIT/BIH arrhythmia database and achieved 99.16% detection rate with sensitivity of 0.9935 and positive predictivity of 0.9981. The method was compared with two widely used R peaks detection algorithms.

  8. ARQ scheme reinforced with past acknowledgement signals

    Science.gov (United States)

    Nakamura, Makoto; Takada, Yasushi

    An ARQ (automatic-repeat-request) scheme that can reduce the influence of backward channel errors for bidirectional data transmission systems is proposed. The main feature of the scheme is that both present and past acknowledgement signals are utilized to decide whether the data signals should be retransmitted or not. Throughput performance is analyzed in both go-back-N and selective-repeat ARQ. A small number of returned past acknowledgement signals are required to improve the throughput efficiency. For an ideal selective-repeat ARQ with an infinite buffer, increasing the number of returned past acknowledgement signals makes the throughput efficiency asymptotically close to the upper bound.

  9. Deficient efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, A.

    1995-05-01

    This article is a review of utility policy and public opinion related to energy efficiency. The historical background is presented, and the current socioeconomic status is also presented. Many fallacies of past utility policies intended to promote conservation are noted, and it is demonstrated that past policies have not been effective, i.e. the cost of electricity has increased. Given the failure of past practices, fourteen recommendations for future practices are set forth.

  10. Pattern recognition for electroencephalographic signals based on continuous neural networks.

    Science.gov (United States)

    Alfaro-Ponce, M; Argüelles, A; Chairez, I

    2016-07-01

    This study reports the design and implementation of a pattern recognition algorithm to classify electroencephalographic (EEG) signals based on artificial neural networks (NN) described by ordinary differential equations (ODEs). The training method for this kind of continuous NN (CNN) was developed according to the Lyapunov theory stability analysis. A parallel structure with fixed weights was proposed to perform the classification stage. The pattern recognition efficiency was validated by two methods, a generalization-regularization and a k-fold cross validation (k=5). The classifier was applied on two different databases. The first one was made up by signals collected from patients suffering of epilepsy and it is divided in five different classes. The second database was made up by 90 single EEG trials, divided in three classes. Each class corresponds to a different visual evoked potential. The pattern recognition algorithm achieved a maximum correct classification percentage of 97.2% using the information of the entire database. This value was similar to some results previously reported when this database was used for testing pattern classification. However, these results were obtained when only two classes were considered for the testing. The result reported in this study used the whole set of signals (five different classes). In comparison with similar pattern recognition methods that even considered less number of classes, the proposed CNN proved to achieve the same or even better correct classification results.

  11. Epistemological Beliefs and Academic Achievement

    Science.gov (United States)

    Arslantas, Halis Adnan

    2016-01-01

    This study aimed to identify the relationship between teacher candidates' epistemological beliefs and academic achievement. The participants of the study were 353 teacher candidates studying their fourth year at the Education Faculty. The Epistemological Belief Scale was used which adapted to Turkish through reliability and validity work by…

  12. Adolescents' Academic Expectations and Achievement.

    Science.gov (United States)

    Sanders, Christopher E.; Field, Tiffany M.; Diego, Miguel A.

    2001-01-01

    Hypothesis that mother relationships are more influential than father relationships on adolescents' academic expectations and achievement was tested with 80 high school seniors. The mother child relationship was found to be predictive of academic expectations. It suggests that the amount of time they spend together may be the contributing factor.…

  13. The opening of achievement report

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The unified plan for Sharqu River has been worked out by experts from Yangtze Water Conservancy Commission, Yangtze Hydraulic Engineering Investigation Academy, and the Academy from T.A.R. A meeting of reporting their achievements has been hold in Lhasa.

  14. Chinese Achievements Attract Worldwide Attention

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    THE People’s Republic of China was founded 45 years ago. Since the policies of economic and social reform and opening were carried out in the beginning of the 1980s, China has been gradually entering into prosperity and has made inspiring achievements. 1. The living standards of the people and their

  15. Achieving universal access to broadband

    DEFF Research Database (Denmark)

    Falch, Morten; Henten, Anders

    2009-01-01

    The paper discusses appropriate policy measures for achieving universal access to broadband services in Europe. Access can be delivered by means of many different technology solutions described in the paper. This means a greater degree of competition and affects the kind of policy measures...

  16. Achieving a sustainable service advantage.

    Science.gov (United States)

    Coyne, K P

    1993-01-01

    Many managers believe that superior service should play little or no role in competitive strategy; they maintain that service innovations are inherently copiable. However, the author states that this view is too narrow. For a company to achieve a lasting service advantage, it must base a new service on a capability gap that competitors cannot or will not copy.

  17. Achieving world class maintenance status

    Energy Technology Data Exchange (ETDEWEB)

    Tomlingson, P.D. [Paul D. Tomingson Associates (United States)

    2007-08-15

    The article written by a management consultant, discusses the art of successful planning and operation of maintenance in mines considering factors such as benchmaking, key performance indices (KPIs) and frequency of procedures which can help achieve 'world class maintenance'. 1 fig.

  18. Faculty Development: Assessing Learner Achievement.

    Science.gov (United States)

    Frey, Barbara A.; Overfield, Karen

    This study addressed the challenges of developing a faculty professional development workshop on assessment, measurement, and evaluation of achievement in adult learners. The setting for the workshop was a system of postsecondary career colleges throughout the United States. The curriculum development model of D. Kirkpatrick (1994) was used as a…

  19. Nyquist filtering of 160 GBaud NRZ-like DPSK signal

    DEFF Research Database (Denmark)

    Hu, Hao; Wang, Ju; Ji, Hua;

    2013-01-01

    We have generated a phase-correlated 160 GBaud NRZ-like DPSK signal based on XPM in a HNLF. The generated 160 GBaud DPSK signal is Nyquist filtered with minimized ISI and error-free performance is achieved.......We have generated a phase-correlated 160 GBaud NRZ-like DPSK signal based on XPM in a HNLF. The generated 160 GBaud DPSK signal is Nyquist filtered with minimized ISI and error-free performance is achieved....

  20. Florigen signaling.

    Science.gov (United States)

    Tsuji, Hiroyuki; Taoka, Ken-Ichiro

    2014-01-01

    Florigen is a systemic signal that promotes flowering. Its molecular nature is a conserved FLOWERING LOCUS T (FT) protein that belongs to the PEBP family. FT is expressed in the leaf phloem and transported to the shoot apical meristem where it initiates floral transition. In the cells of the meristem, FT binds 14-3-3 proteins and bZIP transcription factor FD to form the florigen activation complex, FAC, which activates floral meristem identity genes such as AP1. The FAC model provides molecular basis for multiple functions of FT beyond flowering through changes of its partners and transcriptional targets. The surface of FT protein includes several regions essential for transport and functions, suggesting the binding of additional components that support its function. FT expression is under photoperiodic control, involving a conserved GIGANTEA-CONSTANS-FT regulatory module with species-specific modifications that contribute variations of flowering time in natural populations.

  1. VLSI mixed signal processing system

    Science.gov (United States)

    Alvarez, A.; Premkumar, A. B.

    1993-01-01

    An economical and efficient VLSI implementation of a mixed signal processing system (MSP) is presented in this paper. The MSP concept is investigated and the functional blocks of the proposed MSP are described. The requirements of each of the blocks are discussed in detail. A sample application using active acoustic cancellation technique is described to demonstrate the power of the MSP approach.

  2. Energy efficiency and SINR maximization beamformers for cognitive radio utilizing sensing information

    KAUST Repository

    Alabbasi, Abdulrahman

    2014-06-01

    In this paper we consider a cognitive radio multi-input multi-output environment in which we adapt our beamformer to maximize both energy efficiency and signal to interference plus noise ratio (SINR) metrics. Our design considers an underlaying communication using adaptive beamforming schemes combined with the sensing information to achieve an optimal energy efficient system. The proposed schemes maximize the energy efficiency and SINR metrics subject to cognitive radio and quality of service constraints. Since the optimization of energy efficiency problem is not a convex problem, we transform it into a standard semi-definite programming (SDP) form to guarantee a global optimal solution. Analytical solution is provided for one scheme, while the other scheme is left in a standard SDP form. Selected numerical results are used to quantify the impact of the sensing information on the proposed schemes compared to the benchmark ones.

  3. Novel efficient and secure medical data transmission on WiMAX.

    Science.gov (United States)

    Kumar, Basant; Singh, Harsh Vikram; Singh, S P; Mohan, Anand

    2008-12-01

    This paper discusses an improved technique for bandwidth-efficient and secure transmission of medical records over simulated orthogonal frequency division multiplexing (OFDM)-based Worldwide Interoperability for Microwave Access (WiMAX)/IEEE 802.16 physical layer. Medical data compaction along with security has been achieved by embedding electrocardiogram (ECG) data into Haar wavelet coefficients of an x-ray image that is transmitted over the channel. The compaction ratio and peak signal-to-noise ratio (PSNR) between the transmitted and received x-ray images for visual clinical performance have been evaluated. It is shown that 12.5% data compaction along with true reception of ECG signal can be achieved for channel signal-to-noise ratio (SNR) >or= 9.6 dB while the achieved PSNR was 55.97 dB. The PSNR value is well above the minimum acceptable 35 dB level, making it potentially useful for secure and bandwidth-efficient transmission of clinical records.

  4. Metacognition, achievement goals, study strategies and academic achievement: pathways to achievement

    NARCIS (Netherlands)

    Vrugt, A.; Oort, F.J.

    2008-01-01

    The purpose of this research was to develop and test a model of effective selfregulated learning. Based on effort expenditure we discerned effective self-regulators and less effective self-regulators. The model comprised achievement goals (mastery, performance-approach and -avoidance goals), metacog

  5. Metacognition, Achievement Goals, Study Strategies and Academic Achievement: Pathways to Achievement

    Science.gov (United States)

    Vrugt, Anneke; Oort, Frans J.

    2008-01-01

    The purpose of this research was to develop and test a model of effective self-regulated learning. Based on effort expenditure we discerned effective self-regulators and less effective self-regulators. The model comprised achievement goals (mastery, performance-approach and -avoidance goals), metacognition (metacognitive knowledge, regulation and…

  6. The incongruous achiever in adolescence.

    Science.gov (United States)

    Kline, S A; Golombek, H

    1974-06-01

    The authors wished to study some of the internal psychological dynamics of achievement in a nonpatient identified high school population. Questionnaires were administered to the Grade 13 students and their parents in a large high school. A number of students whose achievement and educational plans were not congruous with their general background were selected for interview. The findings suggest that a wide variety of ages and developmental stages can be discerned as critical points in the development of a student's attitude toward higher education. These students have many values in common, and their values appear related to a positive or negative identification with parental values. The students themselves show a wide range of personality integration. They relate in a special way to a wide variety of teachers' personalities.

  7. Improving OR Efficiency.

    Science.gov (United States)

    Vassell, Patricia

    2016-08-01

    The high-cost/high-revenue environment of the OR requires special attention from managers to scrutinize and reduce costs. In the OR, nonlabor cost savings (ie, no staff member will be laid off or reclassified to realize cost savings) can typically be identified most readily. Operational costs in the OR are affected by start times, turnover times, cancellation rates, and adequate supplies, equipment, and staffing. Inefficiency in the OR can increase costs and lead to dissatisfied patients, physicians, and staff members. This article describes concepts that contribute to efficiency in the OR and illustrates the importance of staff member engagement in achieving desired outcomes.

  8. Database Research: Achievements and Challenges

    Institute of Scientific and Technical Information of China (English)

    Shan Wang; Xiao-Yong Du; Xiao-Feng Meng; Hong Chen

    2006-01-01

    Database system is the infrastructure of the modern information system. The R&D in the database system moves along by giant steps. This report presents the achievements Renmin University of China (RUC) has made in the past 25 years and at the same time addresses some of the research projects we, RUC, are currently working on. The National Natural Science Foundation of China supports and initiates most of our research projects and these successfully conducted projects have produced fruitful results.

  9. Predicting educational achievement from DNA

    Science.gov (United States)

    Selzam, S; Krapohl, E; von Stumm, S; O'Reilly, P F; Rimfeld, K; Kovas, Y; Dale, P S; Lee, J J; Plomin, R

    2017-01-01

    A genome-wide polygenic score (GPS), derived from a 2013 genome-wide association study (N=127,000), explained 2% of the variance in total years of education (EduYears). In a follow-up study (N=329,000), a new EduYears GPS explains up to 4%. Here, we tested the association between this latest EduYears GPS and educational achievement scores at ages 7, 12 and 16 in an independent sample of 5825 UK individuals. We found that EduYears GPS explained greater amounts of variance in educational achievement over time, up to 9% at age 16, accounting for 15% of the heritable variance. This is the strongest GPS prediction to date for quantitative behavioral traits. Individuals in the highest and lowest GPS septiles differed by a whole school grade at age 16. Furthermore, EduYears GPS was associated with general cognitive ability (~3.5%) and family socioeconomic status (~7%). There was no evidence of an interaction between EduYears GPS and family socioeconomic status on educational achievement or on general cognitive ability. These results are a harbinger of future widespread use of GPS to predict genetic risk and resilience in the social and behavioral sciences. PMID:27431296

  10. Energy efficiency; Energieffektivisering

    Energy Technology Data Exchange (ETDEWEB)

    2009-06-15

    The Low Energy Panel will halve the consumption in buildings. The Panel has proposed a halving of consumption in the construction within 2040 and 20 percent reduction in the consumption in the industry within 2020. The Panel consider it as possible to gradually reduce consumption in buildings from the current level of 80 TWh with 10 TWh in 2020, 25 TWh in 2030 and 40 TWh in 2040. According the committee one such halving can be reached by significant efforts relating to energy efficiency, by greater rehabilitations, energy efficiency in consisting building stock and stricter requirements for new construction. For the industry field the Panel recommend a political goal to be set at least 20 percent reduction in specific energy consumption in the industry and primary industry beyond general technological development by the end of 2020. This is equivalent to approximately 17 TWh based on current level of activity. The Panel believes that a 5 percent reduction should be achieved by the end of 2012 by carrying out simple measures. The Low Energy Panel has since March 2009 considered possibilities to strengthen the authorities' work with energy efficiency in Norway. The wide complex panel adds up proposals for a comprehensive approach for increased energy efficiency in particular in the building- and industry field. The Panel has looked into the potential for energy efficiency, barriers for energy efficiency, assessment of strengths and weaknesses in the existing policy instruments and members of the Panel's recommendations. In addition the report contains a review of theoretical principles for effects of instruments together with an extensive background. One of the committee members have chosen to take special notes on the main recommendations in the report. (AG)

  11. Cooperation Mechanisms To Achieve Eu Renewable Targets

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik; Pade, Lise-Lotte; Schröder, Sascha Thorsten

    2014-01-01

    for cooperation mechanisms such as joint support schemes for promoting renewable energy to meet the 2020 targets. The potential coordination benefits, with more efficient localisation and composition of renewable investment, can be achieved by creating new areas/sub-segments of renewable technologies where...... connection of new capacity to the electricity grid and cost sharing rules for electricity transmission expansion are examined and examples given. The influence of additional renewable capacity on domestic/regional power market prices can be a barrier. The market will be influenced by for example an expansion...... of the wind capacity resulting in lower prices, which will affect existing conventional producers. This development will be opposed by conventional producers, whereas consumers will support such a strategy. A major barrier is the timing of RES targets and the uncertainty regarding future targets. We...

  12. Signal enhanced holographic fluorescence microscopy with guide-star reconstruction

    Science.gov (United States)

    Jang, Changwon; Clark, David C.; Kim, Jonghyun; Lee, Byoungho; Kim, Myung K.

    2016-01-01

    We propose a signal enhanced guide-star reconstruction method for holographic fluorescence microscopy. In the late 00’s, incoherent digital holography started to be vigorously studied by several groups to overcome the limitations of conventional digital holography. The basic concept of incoherent digital holography is to acquire the complex hologram from incoherent light by utilizing temporal coherency of a spatially incoherent light source. The advent of incoherent digital holography opened new possibility of holographic fluorescence microscopy (HFM), which was difficult to achieve with conventional digital holography. However there has been an important issue of low and noisy signal in HFM which slows down the system speed and degrades the imaging quality. When guide-star reconstruction is adopted, the image reconstruction gives an improved result compared to the conventional propagation reconstruction method. The guide-star reconstruction method gives higher imaging signal-to-noise ratio since the acquired complex point spread function provides optimal system-adaptive information and can restore the signal buried in the noise more efficiently. We present theoretical explanation and simulation as well as experimental results. PMID:27446653

  13. Scalable Video Coding with Interlayer Signal Decorrelation Techniques

    Directory of Open Access Journals (Sweden)

    Yang Wenxian

    2007-01-01

    Full Text Available Scalability is one of the essential requirements in the compression of visual data for present-day multimedia communications and storage. The basic building block for providing the spatial scalability in the scalable video coding (SVC standard is the well-known Laplacian pyramid (LP. An LP achieves the multiscale representation of the video as a base-layer signal at lower resolution together with several enhancement-layer signals at successive higher resolutions. In this paper, we propose to improve the coding performance of the enhancement layers through efficient interlayer decorrelation techniques. We first show that, with nonbiorthogonal upsampling and downsampling filters, the base layer and the enhancement layers are correlated. We investigate two structures to reduce this correlation. The first structure updates the base-layer signal by subtracting from it the low-frequency component of the enhancement layer signal. The second structure modifies the prediction in order that the low-frequency component in the new enhancement layer is diminished. The second structure is integrated in the JSVM 4.0 codec with suitable modifications in the prediction modes. Experimental results with some standard test sequences demonstrate coding gains up to 1 dB for I pictures and up to 0.7 dB for both I and P pictures.

  14. Computationally efficient algorithm for fast transients detection

    CERN Document Server

    Soudlenkov, Gene

    2011-01-01

    Computationally inexpensive algorithm for detecting of dispersed transients has been developed using Cumulative Sums (CUSUM) scheme for detecting abrupt changes in statistical characteristics of the signal. The efficiency of the algorithm is demonstrated on pulsar PSR J0835-4510.

  15. Efficiency stud

    Directory of Open Access Journals (Sweden)

    Brundaban Patro

    2016-03-01

    Full Text Available This paper presents the study of combination tube boilers, as applicable to commercial use, along with the significant features, limitations, and applicability. A heat balance sheet is prepared to know the various heat losses in two different two-pass combination tube boilers, using low grade coal and rice husk as a fuel. Also, the efficiency of the combination tube boilers is studied by the direct and heat loss methods. It is observed that the dry flue gas loss is a major loss in the combination tube boilers. The loss due to the unburnt in the fly ash is very less in the combination tube boilers, due to the surrounded membrane wall. It is also observed that the loss due to the unburnt in the bottom ash has a considerable amount for the heat loss, and cannot be ignored.

  16. Achieving the Renewable Energy Target for Jamaica

    Directory of Open Access Journals (Sweden)

    Abdullahi Olabode ABDULKADRI

    2014-05-01

    Full Text Available ieving the Renewable Energy Target for Jamaica Abstract: The high cost of energy in Jamaica, one of the highest in the Caribbean region, is usually cited as a hindrance to industrial development and efficiency, especially in the manufacturing sector. High energy cost is also considered to be a national energy security issue and the government is taking steps to ensure adequate supply of energy at affordable prices. In the current National Development Plan, the government has set a target for renewable energy sources to supply 20% of the country's energy need by the year 2030. Using a linear programing model of energy planning, we examine how realistically this target could be achieved. Our findings indicate that the 20% renewable energy target is technically achievable with the optimal plan showing a mixture of wind power, hydropower and bagasse power but no solar power. However, when the timeline for investment in new generating capacities that will ensure the attainment of the target is considered, it becomes highly improbable that the target will be met. This study fills the gap that exists in evidence-based analysis of energy policy in Jamaica.

  17. Numerical analysis for four-wave mixing based wavelength conversion of differential phase-shift keying signals

    Institute of Scientific and Technical Information of China (English)

    Liang Jia; Fan Zhang; Ming Li; Yuliang Liu; Zhangyuan Chen

    2009-01-01

    We numerically investigate the main constrains for high efficiency wavelength conversion of differential phase-shift keying (DPSK) signals based on four-wave mixing (FWM) in highly nonlinear fiber (HNLF). Using multi-tone pump phase modulation techniques, high efficiency wavelength conversion of DPSK signals is achieved with the stimulated Brillouin scattering (SBS) effects effectively suppressed. Our analysis shows that there is a compromise between conversion efficiency and converted idler degradation. By optimizing the pump phase modulation configuration, the converted DPSK idler's degradation can be dramatically decreased through balancing SBS suppression and pump phase modulation degradation. Our simulation results also show that these multi-tone pump phase modulation techniques are more appropriate for the future high bit rate systems.

  18. Seismic signal processing on heterogeneous supercomputers

    Science.gov (United States)

    Gokhberg, Alexey; Ermert, Laura; Fichtner, Andreas

    2015-04-01

    require dedicated HPC solutions. The chosen application is using a wide range of common signal processing methods, which include various IIR filter designs, amplitude and phase correlation, computing the analytic signal, and discrete Fourier transforms. Furthermore, various processing methods specific for seismology, like rotation of seismic traces, are used. Efficient implementation of all these methods on the GPU-accelerated systems represents several challenges. In particular, it requires a careful distribution of work between the sequential processors and accelerators. Furthermore, since the application is designed to process very large volumes of data, special attention had to be paid to the efficient use of the available memory and networking hardware resources in order to reduce intensity of data input and output. In our contribution we will explain the software architecture as well as principal engineering decisions used to address these challenges. We will also describe the programming model based on C++ and CUDA that we used to develop the software. Finally, we will demonstrate performance improvements achieved by using the heterogeneous computing architecture. This work was supported by a grant from the Swiss National Supercomputing Centre (CSCS) under project ID d26.

  19. Achieving Universal Access to Broadband

    Directory of Open Access Journals (Sweden)

    Morten FALCH

    2009-01-01

    Full Text Available The paper discusses appropriate policy measures for achieving universal access to broadband services in Europe. Access can be delivered by means of many different technology solutions described in the paper. This means a greater degree of competition and affects the kind of policy measures to be applied. The paper concludes that other policy measure than the classical universal service obligation are in play, and discusses various policy measures taking the Lisbon process as a point of departure. Available policy measures listed in the paper include, universal service obligation, harmonization, demand stimulation, public support for extending the infrastructure, public private partnerships (PPP, and others.

  20. WAVELET ANALYSIS OF MODULATED SIGNALS

    Institute of Scientific and Technical Information of China (English)

    Hu Jianwei; Yang Shaoquan

    2006-01-01

    The relationship between Haar wavelet decomposition coefficients and modulated signal parameters is discussed. A new modulation classification method is presented. The new method uses the amplitude,frequency and phase information derived from Haar wavelet decomposition as feature vectors to distinguish the modulation types of M-ary Frequency-Shift Keying (MFSK), M-ary Phase-Shift Keying (MPSK) and Quadrature Amplitude Modulation (QAM) modulation types. A parallel combined classifier is designed based on these feature vectors. The overall successful recognition rate of 92.4% can be achieved even at a low Signal-to-Noise Ratio (SNR) of 5dB.

  1. Genetic algorithm for the optimization of features and neural networks in ECG signals classification

    Science.gov (United States)

    Li, Hongqiang; Yuan, Danyang; Ma, Xiangdong; Cui, Dianyin; Cao, Lu

    2017-01-01

    Feature extraction and classification of electrocardiogram (ECG) signals are necessary for the automatic diagnosis of cardiac diseases. In this study, a novel method based on genetic algorithm-back propagation neural network (GA-BPNN) for classifying ECG signals with feature extraction using wavelet packet decomposition (WPD) is proposed. WPD combined with the statistical method is utilized to extract the effective features of ECG signals. The statistical features of the wavelet packet coefficients are calculated as the feature sets. GA is employed to decrease the dimensions of the feature sets and to optimize the weights and biases of the back propagation neural network (BPNN). Thereafter, the optimized BPNN classifier is applied to classify six types of ECG signals. In addition, an experimental platform is constructed for ECG signal acquisition to supply the ECG data for verifying the effectiveness of the proposed method. The GA-BPNN method with the MIT-BIH arrhythmia database achieved a dimension reduction of nearly 50% and produced good classification results with an accuracy of 97.78%. The experimental results based on the established acquisition platform indicated that the GA-BPNN method achieved a high classification accuracy of 99.33% and could be efficiently applied in the automatic identification of cardiac arrhythmias.

  2. Solar water splitting: efficiency discussion

    CERN Document Server

    Juodkazyte, Jurga; Sebeka, Benjaminas; Savickaja, Irena; Malinauskas, Tadas; Badokas, Kazimieras; Juodkazis, Kestutis; Juodkazis, Saulius

    2016-01-01

    The current state of the art in direct water splitting in photo-electrochemical cells (PECs) is presented together with: (i) a case study of water splitting using a simple solar cell with the most efficient water splitting electrodes and (ii) a detailed mechanism analysis. Detailed analysis of the energy balance and efficiency of solar hydrogen production are presented. The role of hydrogen peroxide formation as an intermediate in oxygen evolution reaction is newly revealed and explains why an oxygen evolution is not taking place at the thermodynamically expected 1.23 V potential. Solar hydrogen production with electrical-to-hydrogen conversion efficiency of 52% is demonstrated using a simple ~0.7%-efficient n-Si/Ni Schottky solar cell connected to a water electrolysis cell. This case study shows that separation of the processes of solar harvesting and electrolysis avoids photo-electrode corrosion and utilizes optimal electrodes for hydrogen and oxygen evolution reactions and achieves ~10% efficiency in light...

  3. FIPSER: Performance Study of a Readout Concept With Few Digitization Levels for Fast Signals

    CERN Document Server

    Limyansky, Brent; Cressler, John D; Otte, Adam Nepomuk; Taboada, Ignacio; Ulusoy, Cagri

    2016-01-01

    We discuss the performance of a readout system, Fixed Pulse Shape Efficient Readout (FIPSER), to digitize signals from detectors with a fixed pulse shape. In this study we are mainly interested in the readout of fast photon detectors like photomultipliers or Silicon photomultipliers. But the concept can be equally applied to the digitization of other detector signals. FIPSER is based on the flash analog to digital converter (FADC) concept, but has the potential to lower costs and power consumption by using an order of magnitude fewer discrete voltage levels. Performance is bolstered by combining the discretized signal with the knowledge of the underlying pulse shape. Simulated FIPSER data was reconstructed with two independent methods. One using a maximum likelihood method and the other using a modified chisquared test. Both methods show that utilizing 12 discrete voltage levels with a sampling rate of 4 samples per full width half maximum (FWHM) of the pulse achieves an amplitude resolution that is better th...

  4. Real-time reception of multi-gigabit coherent optical OFDM signals.

    Science.gov (United States)

    Yang, Qi; Chen, Simin; Ma, Yiran; Shieh, William

    2009-05-11

    Coherent Optical OFDM (CO-OFDM) has been demonstrated for delivering superior performance in spectral efficiency, receiver sensitivity, and polarization-dispersion resilience. Fueled by the rapid advancement in semiconductor technology, high-speed field-programmable gate arrays (FPGA) and analogue-to-digital-converters/digital-to-analogue converters (ADC/DACs) have been increasingly adopted for digital signal processing in optical communications. In this paper, we report the first FPGA-based real-time implementation of coherent optical OFDM (CO-OFDM) receiver with a transmission rate up to 3.1 Gb/s. Several basic aspects of CO-OFDM signal processing are described in detail, and the BER sensitivity performance are evaluated in real-time. To the best of our knowledge, we have achieved the record real-time reception date rate for a single-input single-output (SISO) coherent OFDM signal, in either RF domain or optical domain.

  5. Teacher Quality and Student Achievement

    Directory of Open Access Journals (Sweden)

    Linda Darling-Hammond

    2000-01-01

    Full Text Available Using data from a 50-state survey of policies, state case study analyses, the 1993-94 Schools and Staffing Surveys (SASS, and the National Assessment of Educational Progress (NAEP, this study examines the ways in which teacher qualifications and other school inputs are related to student achievement across states. The findings of both the qualitative and quantitative analyses suggest that policy investments in the quality of teachers may be related to improvements in student performance. Quantitative analyses indicate that measures of teacher preparation and certification are by far the strongest correlates of student achievement in reading and mathematics, both before and after controlling for student poverty and language status. State policy surveys and case study data are used to evaluate policies that influence the overall level of teacher qualifications within and across states. This analysis suggests that policies adopted by states regarding teacher education, licensing, hiring, and professional development may make an important difference in the qualifications and capacities that teachers bring to their work. The implications for state efforts to enhance quality and equity in public education are discussed.

  6. Updates and achievements in virology.

    Science.gov (United States)

    Buonaguro, Franco M; Campadelli-Fiume, Gabriella; De Giuli Morghen, Carlo; Palù, Giorgio

    2010-07-01

    The 4th European Congress of Virology, hosted by the Italian Society for Virology, attracted approximately 1300 scientists from 46 countries worldwide. It also represented the first conference of the European Society for Virology, which was established in Campidoglio, Rome, Italy in 2009. The main goal of the meeting was to share research activities and results achieved in European virology units/institutes and to strengthen collaboration with colleagues from both western and developing countries. The worldwide representation of participants is a testament to the strength and attraction of European virology. The 5-day conference brought together the best of current virology; topics covered all three living domains (bacteria, archaea and eucarya), with special sessions on plant and veterinary virology as well as human virology, including two oral presentations on mimiviruses. The conference included five plenary sessions, 31 workshops, one hepatitis C virus roundtable, ten special workshops and three poster sessions, as well as 45 keynote lectures, 191 oral presentations and 845 abstracts. Furthermore, the Gesellschaft fur Virologie Loeffler-Frosch medal award was given to Peter Vogt for his long-standing career and achievements; the Gardner Lecture of the European Society for Clinical Virology was presented by Yoshihiro Kawaoka, and the Pioneer in Virology Lecture of the Italian Society for Virology was presented by Ulrich Koszinowski.

  7. High-efficiency FRET-enhanced photoacoustic probes for in vivo tumor imaging

    Science.gov (United States)

    Qin, Huan; Liu, Liming

    2017-01-01

    Photoacoustic imaging can provide high-resolution and high-contrast image under unprecedented depth compared with pure optical imaging techniques by making use of laser-induced ultrasound waves. Although a series of absorption-enhanced optical contrast agents for photoacoustic imaging were developed, the probe with fully conversion from absorbed light energy to acoustic energy has not been achieved so far. Here we develop a high-efficiency photoacoustic probes with fluorescence resonance energy transfer (FRET) effect for enhancement of nonradiative energy. Graphene oxide (GO) binding optical dyes (GO-dyes) were achieved to show highly fluorescence quenching and violently increased photoacoustic signal intensity. GO-dyes were constructed and testified for multi-spectral photoacoustic imaging. As a representative probe, GO-Cy7 nanoparticles were used to validate the feasibility of photoacoustic tumor molecular imaging in vivo. Our work demonstrated a new approach to construct high-efficiency FRET-enhanced multi-spectrum probes for photoacoustic molecular imaging.

  8. A bandwidth efficient two-user cooperative diversity system with limited feedback

    Institute of Scientific and Technical Information of China (English)

    LI Jing; GE JianHua; WANG Yong; TANG YunShuai; XIONG Xiong

    2009-01-01

    A two-user cooperative diversity system based on Alamouti signaling was proposed, which utilizes the orthogonal structure of Alamouti signaling to make cooperative users relay on the shared channel resources so that the spectral efficiency of the traditional cooperative system can be improved. When M-ary phase shift keying (M-PSK) modulation and an improved selection decode-and-forward (SDF) relaying protocol with limited feedback are used at the users and m(m ≥1) receive antennas are configured at the base station, the average bit-error-rata (BER) system performance for statistically similar uplink channels was derived and it was verified by simulations. Under various channel scenarios of interest, numerical and simulation results show that the diversity gain achieved and the BER performance of the proposed system increase with the interuser channel quality, and the full transmit diversity order of two can be obtained for sufficiently high interuser signal-to-noise ratios (SNRs).

  9. Dynamics in atomic signaling games

    KAUST Repository

    Fox, Michael J.

    2015-04-08

    We study an atomic signaling game under stochastic evolutionary dynamics. There are a finite number of players who repeatedly update from a finite number of available languages/signaling strategies. Players imitate the most fit agents with high probability or mutate with low probability. We analyze the long-run distribution of states and show that, for sufficiently small mutation probability, its support is limited to efficient communication systems. We find that this behavior is insensitive to the particular choice of evolutionary dynamic, a property that is due to the game having a potential structure with a potential function corresponding to average fitness. Consequently, the model supports conclusions similar to those found in the literature on language competition. That is, we show that efficient languages eventually predominate the society while reproducing the empirical phenomenon of linguistic drift. The emergence of efficiency in the atomic case can be contrasted with results for non-atomic signaling games that establish the non-negligible possibility of convergence, under replicator dynamics, to states of unbounded efficiency loss.

  10. Progress, Wealth, and Mathematics Achievement

    DEFF Research Database (Denmark)

    Valero, Paola

    2013-01-01

    international mathematics education journal (Laisant & Fehr, 1899). In the times of the Cold War, a similar argument emerged, however the justification was related to keeping the supremacy of the Capitalist West in front of the growing menace of the expansion of the Communist Soviet Union. Nowadays...... as a result, among others, of the growing series of comparative information on educational achievement and development. Such reports can be seen as performances of the comparative logic of Modernity that operates differential positioning, not only among individuals but also among nations, with respect to what...... is considered to be the desired and normal level of development and growth. “Mathematics for all” can be seen as an effect of power that operates on subjects and nations alike to determine who are the individuals/nations who excel, while creating a narrative of inclusion for all those who, by the very same...

  11. Robust Clustering of Acoustic Emission Signals Using Neural Networks and Signal Subspace Projections

    Directory of Open Access Journals (Sweden)

    Shi Zhiqiang

    2003-01-01

    Full Text Available Acoustic emission-based techniques are being used for the nondestructive inspection of mechanical systems. For reliable automatic fault monitoring related to the generation and propagation of cracks, it is important to identify the transient crack-related signals in the presence of strong time-varying noise and other interference. A prominent difficulty is the inability to differentiate events due to crack growth from noise of various origins. This work presents a novel algorithm for automatic clustering and separation of acoustic emission (AE events based on multiple features extracted from the experimental data. The algorithm consists of two steps. In the first step, the noise is separated from the events of interest and subsequently removed using a combination of covariance analysis, principal component analysis (PCA, and differential time delay estimates. The second step processes the remaining data using a self-organizing map (SOM neural network, which outputs the noise and AE signals into separate neurons. To improve the efficiency of classification, the short-time Fourier transform (STFT is applied to retain the time-frequency features of the remaining events, reducing the dimension of the data. The algorithm is verified with two sets of data, and a correct classification ratio over 95% is achieved.

  12. Spectral Efficiency of Multiple Access Fading Channels with Adaptive Interference Cancellation

    CERN Document Server

    Shakya, Indu L

    2012-01-01

    Reliable estimation of users' channels and data in rapidly time varying fading environments is a very challenging task of multiuser detection (MUD) techniques that promise impressive capacity gains for interference limited systems such as non-orthogonal CDMA and spatial multiplexing MIMO based LTE. This paper analyzes relative channel estimation error performances of conventional single user and multiuser receivers for an uplink of DS-CDMA and shows their impact on output signal to interference and noise ratio (SINR) performances. Mean squared error (MSE) of channel estimation and achievable spectral efficiencies of these receivers obtained from the output SINR calculations are then compared with that achieved with new adaptive interference canceling receivers. It is shown that the adaptive receivers using successive (SIC) and parallel interference cancellation (PIC) methods offer much improved channel estimation and SINR performances, and hence significant increase in achievable sum date rates.

  13. Improvements on Signal Processing for HF Radar

    Institute of Scientific and Technical Information of China (English)

    LIU Yongtan; SHEN Yiying

    2001-01-01

    In this paper improvements on signalprocessing are achieved to enhance the performancesof H-F radar system, being unobtainable by the con-ventional signal processing. Using the improved sig-nal processing both high range resolution and longcoherent integration time may be obtained for goodbenefit to the target resolution and weak signal de-tection. Modification to the unmatched correspon-dence between range delay samples and range resolu-tion ceils saves an additional accumulation loss in therange processing. Finally, comparisons between theimproved and the conventional signal processing aregiven by numerical simulation.

  14. Optimal temporal patterns for dynamical cellular signaling

    Science.gov (United States)

    Hasegawa, Yoshihiko

    2016-11-01

    Cells use temporal dynamical patterns to transmit information via signaling pathways. As optimality with respect to the environment plays a fundamental role in biological systems, organisms have evolved optimal ways to transmit information. Here, we use optimal control theory to obtain the dynamical signal patterns for the optimal transmission of information, in terms of efficiency (low energy) and reliability (low uncertainty). Adopting an activation-deactivation decoding network, we reproduce several dynamical patterns found in actual signals, such as steep, gradual, and overshooting dynamics. Notably, when minimizing the energy of the input signal, the optimal signals exhibit overshooting, which is a biphasic pattern with transient and steady phases; this pattern is prevalent in actual dynamical patterns. We also identify conditions in which these three patterns (steep, gradual, and overshooting) confer advantages. Our study shows that cellular signal transduction is governed by the principle of minimizing free energy dissipation and uncertainty; these constraints serve as selective pressures when designing dynamical signaling patterns.

  15. Using abstract language signals power.

    Science.gov (United States)

    Wakslak, Cheryl J; Smith, Pamela K; Han, Albert

    2014-07-01

    Power can be gained through appearances: People who exhibit behavioral signals of power are often treated in a way that allows them to actually achieve such power (Ridgeway, Berger, & Smith, 1985; Smith & Galinsky, 2010). In the current article, we examine power signals within interpersonal communication, exploring whether use of concrete versus abstract language is seen as a signal of power. Because power activates abstraction (e.g., Smith & Trope, 2006), perceivers may expect higher power individuals to speak more abstractly and therefore will infer that speakers who use more abstract language have a higher degree of power. Across a variety of contexts and conversational subjects in 7 experiments, participants perceived respondents as more powerful when they used more abstract language (vs. more concrete language). Abstract language use appears to affect perceived power because it seems to reflect both a willingness to judge and a general style of abstract thinking.

  16. CEREBRAL PALSY AND MUSIC ACHIEVEMENT

    Directory of Open Access Journals (Sweden)

    Miodrag L. STOSHLJEVIKJ

    2008-12-01

    Full Text Available Pupils with cerebral palsy attend elementary education accordind to a regular and special teaching plan and program. Regular school curriculum was reformed in 1992, while special plan and program has not been changed and adapted according to pupil’s needs and capacities. Music is one of the best means of expressing oneself and plays a very important role in the development of every child, the child with cerebral palsy in particular.In order to test the possibility of pupils with cerebral palsy, with and without mental retardation, to apprehend the actual program content, we have conducted research on musical achievement of children with cerebral palsy. During 2007 a research was carried out, on the sample of 27 pupils with cerebral palsy and mild mental retardation who attended classes in the school “Miodrag Matikj”, and a sample of16 students with cerebral palsy without mental retardation who attended the school “Dr. Dragan Hercog” in Belgrade.Results of the research, as well as analysis of music curriculum content, indicated that the capacities of students with cerebral palsy to carry out the curriculum tasks require special approach and methodology. Therefore, we introduced some proposals to overcome the difficulties in fulfilling music curriculum demands of those pupils. We made special emphasis on the use of computer based Assistive technology which facilitates the whole process to a large extent.

  17. Academic Achievement Among Juvenile Detainees.

    Science.gov (United States)

    Grigorenko, Elena L; Macomber, Donna; Hart, Lesley; Naples, Adam; Chapman, John; Geib, Catherine F; Chart, Hilary; Tan, Mei; Wolhendler, Baruch; Wagner, Richard

    2015-01-01

    The literature has long pointed to heightened frequencies of learning disabilities (LD) within the population of law offenders; however, a systematic appraisal of these observations, careful estimation of these frequencies, and investigation of their correlates and causes have been lacking. Here we present data collected from all youth (1,337 unique admissions, mean age 14.81, 20.3% females) placed in detention in Connecticut (January 1, 2010-July 1, 2011). All youth completed a computerized educational screener designed to test a range of performance in reading (word and text levels) and mathematics. A subsample (n = 410) received the Wide Range Achievement Test, in addition to the educational screener. Quantitative (scale-based) and qualitative (grade-equivalence-based) indicators were then analyzed for both assessments. Results established the range of LD in this sample from 13% to 40%, averaging 24.9%. This work provides a systematic exploration of the type and severity of word and text reading and mathematics skill deficiencies among juvenile detainees and builds the foundation for subsequent efforts that may link these deficiencies to both more formal, structured, and variable definitions and classifications of LD, and to other types of disabilities (e.g., intellectual disability) and developmental disorders (e.g., ADHD) that need to be conducted in future research.

  18. A Year of Exceptional Achievements FY 2008

    Energy Technology Data Exchange (ETDEWEB)

    devore, L; Chrzanowski, P

    2008-11-06

    2008 highlights: (1) Stockpile Stewardship and Complex Transformation - LLNL achieved scientific breakthroughs that explain some of the key 'unknowns' in nuclear weapons performance and are critical to developing the predictive science needed to ensure the safety, reliability, and security of the U.S. nuclear deterrent without nuclear testing. In addition, the National Ignition Facility (NIF) passed 99 percent completion, an LLNL supercomputer simulation won the 2007 Gordon Bell Prize, and a significant fraction of our inventory of special nuclear material was shipped to other sites in support of complex transformation. (2) National and Global Security - Laboratory researchers delivered insights, technologies, and operational capabilities that are helping to ensure national security and global stability. Of particular note, they developed advanced detection instruments that provide increased speed, accuracy, specificity, and resolution for identifying and characterizing biological, chemical, nuclear, and high-explosive threats. (3) Exceptional Science and Technology - The Laboratory continued its tradition of scientific excellence and technical innovation. LLNL scientists made significant contributions to Nobel Prize-winning work on climate change. LLNL also received three R&D 100 awards and six Nanotech 50 awards, and dozens of Laboratory scientists and engineers were recognized with professional awards. These honors provide valuable confirmation that peers and outside experts recognize the quality of our staff and our work. (4) Enhanced Business and Operations - A major thrust under LLNS is to make the Laboratory more efficient and cost competitive. We achieved roughly $75 million in cost savings for support activities through organizational changes, consolidation of services, improved governance structures and work processes, technology upgrades, and systems shared with Los Alamos National Laboratory. We realized nonlabor cost savings of $23 million

  19. Phase noise in pulsed Doppler lidar and limitations on achievable single-shot velocity accuracy

    Science.gov (United States)

    Mcnicholl, P.; Alejandro, S.

    1992-01-01

    The smaller sampling volumes afforded by Doppler lidars compared to radars allows for spatial resolutions at and below some sheer and turbulence wind structure scale sizes. This has brought new emphasis on achieving the optimum product of wind velocity and range resolutions. Several recent studies have considered the effects of amplitude noise, reduction algorithms, and possible hardware related signal artifacts on obtainable velocity accuracy. We discuss here the limitation on this accuracy resulting from the incoherent nature and finite temporal extent of backscatter from aerosols. For a lidar return from a hard (or slab) target, the phase of the intermediate frequency (IF) signal is random and the total return energy fluctuates from shot to shot due to speckle; however, the offset from the transmitted frequency is determinable with an accuracy subject only to instrumental effects and the signal to noise ratio (SNR), the noise being determined by the LO power in the shot noise limited regime. This is not the case for a return from a media extending over a range on the order of or greater than the spatial extent of the transmitted pulse, such as from atmospheric aerosols. In this case, the phase of the IF signal will exhibit a temporal random walk like behavior. It will be uncorrelated over times greater than the pulse duration as the transmitted pulse samples non-overlapping volumes of scattering centers. Frequency analysis of the IF signal in a window similar to the transmitted pulse envelope will therefore show shot-to-shot frequency deviations on the order of the inverse pulse duration reflecting the random phase rate variations. Like speckle, these deviations arise from the incoherent nature of the scattering process and diminish if the IF signal is averaged over times greater than a single range resolution cell (here the pulse duration). Apart from limiting the high SNR performance of a Doppler lidar, this shot-to-shot variance in velocity estimates has a

  20. High-efficiency near- and mid-IR intra-cavity OPO

    Science.gov (United States)

    Kilmer, J.; Yin, Y.; Iadevaia, A.

    2010-04-01

    The near and mid-IR spectral region is of significant interest due to the atmospheric windows present in this region. Applications of lasers operating in this spectral region range from their use in remote sensing LIDAR, IR counter measures (IRCM), spectroscopy and Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) sensing systems. We report the development of a compact, highly efficient, high power intra-cavity pumped all-solid-state optical parametric oscillator (OPO) producing nanosecond pulses at kHz repetition rates with an output tunable from 1.5 microns to 3.4 microns with pulse energies up to 10mJ. With our novel Intra-Cavity OPO design, pump to signal conversion efficiencies up to 65% (which is very close to its quantum efficiency) at room temperature are achievable.

  1. Man-machine interface system for neuromuscular training and evaluation based on EMG and MMG signals.

    Science.gov (United States)

    de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durán, Ramon; Fernández, Patricia

    2010-01-01

    This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

  2. Man-Machine Interface System for Neuromuscular Training and Evaluation Based on EMG and MMG Signals

    Directory of Open Access Journals (Sweden)

    Patricia Fernández

    2010-12-01

    Full Text Available This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System, a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES and, as a novelty, the myomechanic signals (MMS. In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

  3. Coherent Detection of Optical Quadrature Phase-Shift Keying Signals With Carrier Phase Estimation

    Science.gov (United States)

    Ly-Gagnon, Dany-Sebastien; Tsukamoto, Satoshi; Katoh, Kazuhiro; Kikuchi, Kazuro

    2006-01-01

    This paper describes a coherent optical receiver for demodulating optical quadrature phase-shift keying (QPSK) signals. At the receiver, a phase-diversity homodyne detection scheme is employed without locking the phase of the local oscillator (LO). To handle the carrier phase drift, the carrier phase is estimated with digital signal processing (DSP) on the homodyne-detected signal. Such a scheme presents the following major advantages over the conventional optical differential detection. First, its bit error rate (BER) performance is better than that of differential detection. This higher sensitivity can extend the reach of unrepeated transmission systems and reduce crosstalk between multiwavelength channels. Second, the optoelectronic conversion process is linear, so that the whole optical signal information can be postprocessed in the electrical domain. Third, this scheme is applicable to multilevel modulation formats such as M-array PSK and quadrature amplitude modulation (QAM). The performance of the receiver is evaluated through various simulations and experiments. As a result, an unrepeated transmission over 210 km with a 20-Gb/s optical QPSK signal is achieved. Moreover, in wavelength-division multiplexing (WDM) environment, coherent detection allows the filtering of a desired wavelength channel to reside entirely in the electrical domain, taking advantage of the sharp cutoff characteristics of electrical filters. The experiments show the feasibility to transmit polarization-multiplexed 40-Gb/s QPSK signals over 200 km with channel spacing of 16 GHz, leading to a spectral efficiency as high as 2.5 b/s/Hz.

  4. Experimental Study of Umts Radio Signal Propagation Characteristics by Field Measurement

    Directory of Open Access Journals (Sweden)

    Isabona Joseph

    2013-07-01

    Full Text Available Knowledge of propagation characteristics in the mobile channel is important to the design, analysis and optimisation of a cellular system. Such need is of great concern to achieve higher quality standards, lower overall running cost, minimize transmit power, better covering of different areas with different environmental situations. Thus, received signal prediction models play an important role in the RF coverage optimization and efficient use of the available resources in wireless communication. As the demand of location based services (LBS increases in non-line of site (NLOS environment, a robust received signal prediction model is needed to enhance the accuracy of the LBS techniques. This paper presents a large scale received signal prediction model for various types of propagation environment from field measured signal data. Based on the experimental data obtained, path loss exponent and standard deviation of signal strength variability are determined. It is shown that the values of these parameters vary from study location to location in the coverage area. The results indicate that different empirical models for mean signal strength should be used in different regions of the coverage area for cellular network planning.

  5. Signal and image multiresolution analysis

    CERN Document Server

    Ouahabi, Abdelialil

    2012-01-01

    Multiresolution analysis using the wavelet transform has received considerable attention in recent years by researchers in various fields. It is a powerful tool for efficiently representing signals and images at multiple levels of detail with many inherent advantages, including compression, level-of-detail display, progressive transmission, level-of-detail editing, filtering, modeling, fractals and multifractals, etc.This book aims to provide a simple formalization and new clarity on multiresolution analysis, rendering accessible obscure techniques, and merging, unifying or completing

  6. Spectral Correlation of Multicarrier Modulated Signals and Its Application for Signal Detection

    Science.gov (United States)

    Zhang, Haijian; Le Ruyet (Eurasipmember), Didier; Terré, Michel

    2009-12-01

    Spectral correlation theory for cyclostationary time-series signals has been studied for decades. Explicit formulas of spectral correlation function for various types of analog-modulated and digital-modulated signals are already derived. In this paper, we investigate and exploit the cyclostationarity characteristics for two kinds of multicarrier modulated (MCM) signals: conventional OFDM and filter bank based multicarrier (FBMC) signals. The spectral correlation characterization of MCM signal can be described by a special linear periodic time-variant (LPTV) system. Using this LPTV description, we have derived the explicit theoretical formulas of nonconjugate and conjugate cyclic autocorrelation function (CAF) and spectral correlation function (SCF) for OFDM and FBMC signals. According to theoretical spectral analysis, Cyclostationary Signatures (CS) are artificially embedded into MCM signal and a low-complexity signature detector is, therefore, presented for detecting MCM signal. Theoretical analysis and simulation results demonstrate the efficiency and robustness of this CS detector compared to traditionary energy detector.

  7. Spectral Correlation of Multicarrier Modulated Signals and Its Application for Signal Detection

    Directory of Open Access Journals (Sweden)

    Zhang Haijian

    2010-01-01

    Full Text Available Spectral correlation theory for cyclostationary time-series signals has been studied for decades. Explicit formulas of spectral correlation function for various types of analog-modulated and digital-modulated signals are already derived. In this paper, we investigate and exploit the cyclostationarity characteristics for two kinds of multicarrier modulated (MCM signals: conventional OFDM and filter bank based multicarrier (FBMC signals. The spectral correlation characterization of MCM signal can be described by a special linear periodic time-variant (LPTV system. Using this LPTV description, we have derived the explicit theoretical formulas of nonconjugate and conjugate cyclic autocorrelation function (CAF and spectral correlation function (SCF for OFDM and FBMC signals. According to theoretical spectral analysis, Cyclostationary Signatures (CS are artificially embedded into MCM signal and a low-complexity signature detector is, therefore, presented for detecting MCM signal. Theoretical analysis and simulation results demonstrate the efficiency and robustness of this CS detector compared to traditionary energy detector.

  8. Effect of recording condition on the diffraction efficiency of magnetic hologram with magnetic garnet films

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Yuichi, E-mail: nakamura@ee.tut.ac.jp; Takagi, Hiroyuki; Lim, Pang Boey; Inoue, Mitsuteru [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, 1-1 Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)

    2014-09-14

    A holographic memory has been attracting attention as recording media with high recording density and high data transfer rate. We have studied the magnetic garnets as a rewritable and long life media for magnetic holography. However, since the signal intensity of reconstructed image was relatively low, the effects of recording conditions on the diffraction efficiency of magnetic hologram were investigated with experiments and the numerical simulation using COMSOL multi-physics. The diffraction efficiency tends to decrease as increasing the spatial frequency, and the use of short pulse laser with the pulse width of 50 ps was found to be effective to achieve high diffraction efficiency. This suggests that the formation of clear magnetic fringe similar to interference pattern can be obtained by the use of short pulse laser since undesirable heat diffusion during radiation does not occur. On the other hand, the diffraction efficiency increased as increasing the film thickness up to 3.1 μm but was saturated in the garnet film thicker than 3.1 μm in the case of spatial frequency of 1500 line pair/mm. The numerical simulation showed that the effective depth of magnetic fringe was limited about 1.8 μm irrespective of the garnet film thickness because the fringes were connected by thermal diffusion near the surface of the film, and the effective depth is limited due to this connection of the magnetic fringe. Avoiding this fringe connection, much higher diffraction efficiency will be achieved.

  9. Signal Processing of Random Physiological Signals

    CERN Document Server

    Lessard, Charles

    2006-01-01

    Signal Processing of Random Physiological Signals presents the most widely used techniques in signal and system analysis. Specifically, the book is concerned with methods of characterizing signals and systems. Author Charles Lessard provides students and researchers an understanding of the time and frequency domain processes which may be used to evaluate random physiological signals such as brainwave, sleep, respiratory sounds, heart valve sounds, electromyograms, and electro-oculograms.Another aim of the book is to have the students evaluate actual mammalian data without spending most or all

  10. Efficient thermoelectric device

    Science.gov (United States)

    Ila, Daryush (Inventor)

    2010-01-01

    A high efficiency thermo electric device comprising a multi nanolayer structure of alternating insulator and insulator/metal material that is irradiated across the plane of the layer structure with ionizing radiation. The ionizing radiation produces nanocrystals in the layered structure that increase the electrical conductivity and decrease the thermal conductivity thereby increasing the thermoelectric figure of merit. Figures of merit as high as 2.5 have been achieved using layers of co-deposited gold and silicon dioxide interspersed with layers of silicon dioxide. The gold to silicon dioxide ratio was 0.04. 5 MeV silicon ions were used to irradiate the structure. Other metals and insulators may be substituted. Other ionizing radiation sources may be used. The structure tolerates a wide range of metal to insulator ratio.

  11. Asynchronous detection of SSB-SC data signals

    Science.gov (United States)

    Sommerville, T. R.; Hanson, J. V.

    Single sideband (SSB) modulation is a special case of combined amplitude and phase modulation that results in suppresion of either the upper or lower sideband of the modulated signal. A study was carried out to combine the bandwidth efficiency of single sideband suppressed carrier transmission with the simplicity of detection offered by envelope detection as proposed by Hanson (1968). In the case of an analog message waveform this has been shown to be impossible, however for a digital data signal it is required only that the envelope have correct value at the sampling instant. Given this weaker constraint a data precoding/predistortion algorithm is proposed that may be applied in order to obtain a solution. The algorithm measures the squared error between the desired and predicted received levels for a given choice of transmitter inputs and determines a correction to the inputs based on the error gradient. The adaptive processor was able to achieve eye openings of up to 60 percent for single sideband suppressed carrier data signals. The best result used a table lookup to generate the initial input estimates, used two input streams, required knowledge of all data values affected by the block under optimization and considered error in the bits preceding and following the block under adaptation.

  12. Method Of Signal Amplification In Multi-Chromophore Luminescence Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Levitsky, Igor A. (Fall River, MA); Krivoshlykov, Sergei G. (Shrewsbury, MA)

    2004-02-03

    A fluorescence-based method for highly sensitive and selective detection of analyte molecules is proposed. The method employs the energy transfer between two or more fluorescent chromophores in a carefully selected polymer matrix. In one preferred embodiment, signal amplification has been achieved in the fluorescent sensing of dimethyl methylphosphonate (DMMP) using two dyes, 3-aminofluoranthene (AM) and Nile Red (NR), in a hydrogen bond acidic polymer matrix. The selected polymer matrix quenches the fluorescence of both dyes and shifts dye emission and absorption spectra relative to more inert matrices. Upon DMMP sorption, the AM fluorescence shifts to the red at the same time the NR absorption shifts to the blue, resulting in better band overlap and increased energy transfer between chromophores. In another preferred embodiment, the sensitive material is incorporated into an optical fiber system enabling efficient excitation of the dye and collecting the fluorescent signal form the sensitive material on the remote end of the system. The proposed method can be applied to multichromophore luminescence sensor systems incorporating N-chromophores leading to N-fold signal amplification and improved selectivity. The method can be used in all applications where highly sensitive detection of basic gases, such as dimethyl methylphosphonate (DMMP), Sarin, Soman and other chemical warfare agents having basic properties, is required, including environmental monitoring, chemical industry and medicine.

  13. Slope efficiency over 30% single-frequency ytterbium-doped fiber laser based on Sagnac loop mirror filter.

    Science.gov (United States)

    Yin, Mojuan; Huang, Shenghong; Lu, Baole; Chen, Haowei; Ren, Zhaoyu; Bai, Jintao

    2013-09-20

    A high-slope-efficiency single-frequency (SF) ytterbium-doped fiber laser, based on a Sagnac loop mirror filter (LMF), was demonstrated. It combined a simple linear cavity with a Sagnac LMF that acted as a narrow-bandwidth filter to select the longitudinal modes. And we introduced a polarization controller to restrain the spatial hole burning effect in the linear cavity. The system could operate at a stable SF oscillating at 1064 nm with the obtained maximum output power of 32 mW. The slope efficiency was found to be primarily dependent on the reflectivity of the fiber Bragg grating. The slope efficiency of multi-longitudinal modes was higher than 45%, and the highest slope efficiency of the single longitudinal mode we achieved was 33.8%. The power stability and spectrum stability were <2% and <0.1%, respectively, and the signal-to-noise ratio measured was around 60 dB.

  14. Photon-efficient imaging with a single-photon camera

    Science.gov (United States)

    Shin, Dongeek; Xu, Feihu; Venkatraman, Dheera; Lussana, Rudi; Villa, Federica; Zappa, Franco; Goyal, Vivek K.; Wong, Franco N. C.; Shapiro, Jeffrey H.

    2016-06-01

    Reconstructing a scene's 3D structure and reflectivity accurately with an active imaging system operating in low-light-level conditions has wide-ranging applications, spanning biological imaging to remote sensing. Here we propose and experimentally demonstrate a depth and reflectivity imaging system with a single-photon camera that generates high-quality images from ~1 detected signal photon per pixel. Previous achievements of similar photon efficiency have been with conventional raster-scanning data collection using single-pixel photon counters capable of ~10-ps time tagging. In contrast, our camera's detector array requires highly parallelized time-to-digital conversions with photon time-tagging accuracy limited to ~ns. Thus, we develop an array-specific algorithm that converts coarsely time-binned photon detections to highly accurate scene depth and reflectivity by exploiting both the transverse smoothness and longitudinal sparsity of natural scenes. By overcoming the coarse time resolution of the array, our framework uniquely achieves high photon efficiency in a relatively short acquisition time.

  15. Model observer design for multi-signal detection in the presence of anatomical noise

    Science.gov (United States)

    Wen, Gezheng; Markey, Mia K.; Park, Subok

    2017-02-01

    As psychophysical studies are resource-intensive to conduct, model observers are commonly used to assess and optimize medical imaging quality. Model observers are typically designed to detect at most one signal. However, in clinical practice, there may be multiple abnormalities in a single image set (e.g. multifocal multicentric (MFMC) breast cancer), which can impact treatment planning. Prevalence of signals can be different across anatomical regions, and human observers do not know the number or location of signals a priori. As new imaging techniques have the potential to improve multiple-signal detection (e.g. digital breast tomosynthesis may be more effective for diagnosis of MFMC than mammography), image quality assessment approaches addressing such tasks are needed. In this study, we present a model observer to detect multiple signals in an image dataset. A novel implementation of partial least squares (PLS) was developed to estimate different sets of efficient channels directly from the images. The PLS channels are adaptive to the characteristics of signals and the background, and they capture the interactions among signal locations. Corresponding linear decision templates are employed to generate both image-level and location-specific scores on the presence of signals. Our results show that: (1) the model observer can achieve high performance with a reasonably small number of channels; (2) the model observer with PLS channels outperforms that with benchmark modified Laguerre–Gauss channels, especially when realistic signal shapes and complex background statistics are involved; (3) the tasks of clinical interest, and other constraints such as sample size would alter the optimal design of the model observer.

  16. Research on the efficiency of coherent balanced detection

    Science.gov (United States)

    Liu, Hongyang; Ai, Yong; Yang, Xiaobo; Chen, Yang; Ji, Fengzhu; Zhao, Xiaodan

    2016-10-01

    In the spatial coherent optical communication, after long distance transmission, the receiver needs to detect and extract the weak signal, and the balanced detection technology is the key technology in the coherent detection. Using balanced detection technology, not only can further improve the receiving sensitivity of coherent optical detection, but also can suppress the common mode intensity noise, so as to improve the output signal to noise ratio of the system. But the problems are (1) due to external causes (polarization control, input optical power loss error, atmospheric turbulence caused by decay, and so on),at both ends of the balanced detector's input signal can not keep consistent (2) two arms of balanced detector electronic devices (including photodiode and amplifier electronic components) are difficult to achieve perfectly matched. The paper is based on the principle of coherent optical detection, firstly, the advantage of balanced detection compared to single detection is detailed analysis, it is shown that balanced detector used in coherent optical communication system and with the improvement of communication rate, this advantage will more obvious. The theoretical and experimental results have verified several important factors that affect the efficiency of coherent balanced detection, namely, the consistency of the detection response, the atmospheric turbulence and the tracking jitter. It is of reference significant to study the balance detection technology in the spatial coherent optical communication.

  17. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B

    1985-01-01

    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  18. Energy Efficiency Maximization through Cooperative Transmit and Receive Antenna Selection for Multicell MU-MIMO System

    Directory of Open Access Journals (Sweden)

    Yanjie Dong

    2013-01-01

    Full Text Available The capacity of Multiple Input Multiple Output (MIMO system is highly related to the number of active antennas. But as the active antenna number increases, the MIMO system will consume more energy. To maximize the energy efficiency of MIMO system, we propose an antenna selection scheme which can maximize the energy efficiency of BS cluster. In the scheme, ergodic energy efficiency is derived according to large scale channel state information (CSI. Based on this ergodic energy efficiency, we introduce a cost function varied with the number of antennas, in which the effect to the energy efficiency of both the serving BS and the neighbor BS is considered. With this function, we can transform the whole system optimization problem to a sectional optimization problem and obtain a suboptimal antenna set using a heuristic algorithm. Simulation results verify that the proposed approach performs better than the comparison schemes in terms of network energy efficiency and achieves 98% network energy efficiency of the centralized antenna selection scheme. Besides, since the proposed scheme does not need the complete CSI of the neighbor BS, it can effectively reduce the signaling overhead.

  19. Wide-band double-pass discrete Raman amplifier with reflection of signals and pumps

    Institute of Scientific and Technical Information of China (English)

    Zhuyuan Wang(王著元); Yiping Cui(崔一平)

    2004-01-01

    A wide-band(1530-1610 nm)and high efficient double-pass discrete Raman amplifier is reported.In this Raman amplifier,by using a one-end gilded fiber as the broadband reflector,signals and multi-pump are both reflected to propagate through the gain fiber for a second time.An increase in net gain of more than 150% has been achieved compared with that in the typical co-pumped Raman amplifier.The advantages of this proposed new configuration have been experimentally studied by comparing with the recently existing Raman amplifier configurations.

  20. Compressive Sampling of EEG Signals with Finite Rate of Innovation

    Directory of Open Access Journals (Sweden)

    Poh Kok-Kiong

    2010-01-01

    Full Text Available Analyses of electroencephalographic signals and subsequent diagnoses can only be done effectively on long term recordings that preserve the signals' morphologies. Currently, electroencephalographic signals are obtained at Nyquist rate or higher, thus introducing redundancies. Existing compression methods remove these redundancies, thereby achieving compression. We propose an alternative compression scheme based on a sampling theory developed for signals with a finite rate of innovation (FRI which compresses electroencephalographic signals during acquisition. We model the signals as FRI signals and then sample them at their rate of innovation. The signals are thus effectively represented by a small set of Fourier coefficients corresponding to the signals' rate of innovation. Using the FRI theory, original signals can be reconstructed using this set of coefficients. Seventy-two hours of electroencephalographic recording are tested and results based on metrices used in compression literature and morphological similarities of electroencephalographic signals are presented. The proposed method achieves results comparable to that of wavelet compression methods, achieving low reconstruction errors while preserving the morphologiies of the signals. More importantly, it introduces a new framework to acquire electroencephalographic signals at their rate of innovation, thus entailing a less costly low-rate sampling device that does not waste precious computational resources.

  1. A spectrally efficient detect-and-forward scheme with two-tier adaptive cooperation

    KAUST Repository

    Benjillali, Mustapha

    2011-09-01

    We propose a simple relay-based adaptive cooperation scheme to improve the spectral efficiency of "Detect-and-Forward" (DetF) half-duplex relaying in fading channels. In a new common framework, we show that the proposed scheme offers considerable gainsin terms of the achievable information ratescompared to conventional DetF relaying schemes for both orthogonal and non-orthogonal source/relay transmissions. The analysis leads on to a general adaptive cooperation strategy based on the maximization of information rates at the destination which needs to observe only the average signal-to-noise ratios of the links. © 2006 IEEE.

  2. An Efficient Audio Classification Approach Based on Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Lhoucine Bahatti

    2016-05-01

    Full Text Available In order to achieve an audio classification aimed to identify the composer, the use of adequate and relevant features is important to improve performance especially when the classification algorithm is based on support vector machines. As opposed to conventional approaches that often use timbral features based on a time-frequency representation of the musical signal using constant window, this paper deals with a new audio classification method which improves the features extraction according the Constant Q Transform (CQT approach and includes original audio features related to the musical context in which the notes appear. The enhancement done by this work is also lay on the proposal of an optimal features selection procedure which combines filter and wrapper strategies. Experimental results show the accuracy and efficiency of the adopted approach in the binary classification as well as in the multi-class classification.

  3. Energy Efficiency and Reliability in Wireless Biomedical Implant Systems

    CERN Document Server

    Abouei, Jamshid; Plataniotis, Konstantinos N; Pasupathy, Subbarayan

    2011-01-01

    The use of wireless implant technology requires correct delivery of the vital physiological signs of the patient along with the energy management in power-constrained devices. Toward these goals, we present an augmentation protocol for the physical layer of the Medical Implant Communications Service (MICS) with focus on the energy efficiency of deployed devices over the MICS frequency band. The present protocol uses the rateless code with the Frequency Shift Keying (FSK) modulation scheme to overcome the reliability and power cost concerns in tiny implantable sensors due to the considerable attenuation of propagated signals across the human body. In addition, the protocol allows a fast start-up time for the transceiver circuitry. The main advantage of using rateless codes is to provide an inherent adaptive duty-cycling for power management, due to the flexibility of the rateless code rate. Analytical results demonstrate that an 80% energy saving is achievable with the proposed protocol when compared to the IE...

  4. TERMA Framework for Biomedical Signal Analysis: An Economic-Inspired Approach

    Directory of Open Access Journals (Sweden)

    Mohamed Elgendi

    2016-11-01

    Full Text Available Biomedical signals contain features that represent physiological events, and each of these events has peaks. The analysis of biomedical signals for monitoring or diagnosing diseases requires the detection of these peaks, making event detection a crucial step in biomedical signal processing. Many researchers have difficulty detecting these peaks to investigate, interpret and analyze their corresponding events. To date, there is no generic framework that captures these events in a robust, efficient and consistent manner. A new method referred to for the first time as two event-related moving averages (“TERMA” involves event-related moving averages and detects events in biomedical signals. The TERMA framework is flexible and universal and consists of six independent LEGO building bricks to achieve high accuracy detection of biomedical events. Results recommend that the window sizes for the two moving averages ( W 1 and W 2 have to follow the inequality ( 8 × W 1 ≥ W 2 ≥ ( 2 × W 1 . Moreover, TERMA is a simple yet efficient event detector that is suitable for wearable devices, point-of-care devices, fitness trackers and smart watches, compared to more complex machine learning solutions.

  5. Earthquake detection through computationally efficient similarity search

    Science.gov (United States)

    Yoon, Clara E.; O’Reilly, Ossian; Bergen, Karianne J.; Beroza, Gregory C.

    2015-01-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection—identification of seismic events in continuous data—is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact “fingerprints” of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes. PMID:26665176

  6. An Analysis of High School Mathematics Achievement and English Language Arts Achievement as Predictors of Science Achievement

    Science.gov (United States)

    Edwards, Anthony C.

    2012-01-01

    Science assessments require students to read and comprehend questions and to solve mathematical problems. The purpose of this study is to determine whether the following variables can be used to predict science achievement: English language arts achievement, mathematics achievement, socioeconomic status (SES), limited English proficiency (LEP)…

  7. Compressive sensing: A methodological approach to an efficient signal processing

    Directory of Open Access Journals (Sweden)

    Evelio Astaiza-Hoyos

    2015-01-01

    Full Text Available Sensado Compresivo (SC es un nuevo paradigma para la adquisici ón y procesamiento de señales, el cual integra muestreo, compre sión, reducción de dimensionalidad y optimización, lo cual ha captado la atención de una gran cantidad de investigadores; SC permite realizar la reconstrucción de señales dispersas en algún dominio a parti r de un conjunto de mediciones que podrían denominarse incomple tas debido a que la tasa a la cual la señal es muestreada es mucho menor q ue la tasa de Nyquist. En este artículo se presenta una aproxim ación metodológica para abordar problema s en el ámbito del procesamie nto de señales desde l a perspectiva de SC.

  8. Simulation of Trigonometric Signals Using Area-Time Efficient Algorithm

    Directory of Open Access Journals (Sweden)

    Siva Kumar K

    2014-01-01

    Full Text Available In this paper, a parametric Co-ordinate Rotation Digital Computer (CORDIC algorithm is presented, simulating fixed point arithmetic (sine, cosine, and arctangent trigonometric functions evaluation. The Important design options for hardware implementation include iterative, unrolled and unrolled pipelined architectures of the CORDIC module. The design uses the VHDL ’93 backwards-compatible version of the fixed point package, as defined according to the verilog 2008 standard. Hardware performance analysis results are presented in this paper for more than 75 circuit variations implemented on a Spartan 3 Xilinx FPGA, each for different parameter values of the proposed CORDIC module. A maximum 47% increase of speed and 57% area reduction are accomplished, in comparison with other designs. In our simulation design we are using circular co-ordinate system for producing digital trigonometric functions and these are calculated in the two main modes in CORDIC algorithm which are rotation mode and vectoring mode.

  9. Hardware efficient monitoring of input/output signals

    Science.gov (United States)

    Driscoll, Kevin R. (Inventor); Hall, Brendan (Inventor); Paulitsch, Michael (Inventor)

    2012-01-01

    A communication device comprises first and second circuits to implement a plurality of ports via which the communicative device is operable to communicate over a plurality of communication channels. For each of the plurality of ports, the communication device comprises: command hardware that includes a first transmitter to transmit data over a respective one of the plurality of channels and a first receiver to receive data from the respective one of the plurality of channels; and monitor hardware that includes a second receiver coupled to the first transmitter and a third receiver coupled to the respective one of the plurality of channels. The first circuit comprises the command hardware for a first subset of the plurality of ports. The second circuit comprises the monitor hardware for the first subset of the plurality of ports and the command hardware for a second subset of the plurality of ports.

  10. How to achieve care coordination inside health care organizations

    DEFF Research Database (Denmark)

    Prætorius, Thim; Becker, Markus

    2015-01-01

    Understanding how health care organizations can achieve care coordination internally is essential because it is difficult to achieve, but essential for high quality and efficient health care delivery. This article offers an answer by providing a synthesis of knowledge about coordination from...... organization theory, where coordination is a central research topic. The article focuses on intra-organizational coordination, which is challenging especially across boundaries such as departments or professions. It provides an overview of the classic coordination mechanisms, e.g., standardization of work...... processes, but also of recent insights that have identified the conditions that are required to achieve coordination, and how these conditions can be provided by formal mechanisms such as standardization, but also informally by drawing on features of the emerging situation. Such research highlights...

  11. Signals and processing for random signal radars

    Science.gov (United States)

    Moore, G. S.

    1980-06-01

    Signals and associated processing techniques are developed which improve the performance, simplify the implementation, and are more amenable to adaptive operation for radars using the random signal concept. These goals are accomplished through the use of a signal set that is composed of a deterministic spreading function, a binary random or pseudo-random noise source, and a possibly random or pseudo-random pulsing sequence. Techniques are developed for determining the parameters of the spreading function that result in signals with desirable ambiguity functions and high effective power. These techniques are based on the use of window functions for sidelobe control and the theory of chirp waveforms for effective power enhancement.

  12. Femtosecond laser direct writing of gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass

    Energy Technology Data Exchange (ETDEWEB)

    Vishnubhatla, K C; Kumar, R Sai Santosh; Rao, D Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Rao, S Venugopal [ACRHEM, University of Hyderabad, Hyderabad 500046 (India); Osellame, R; Ramponi, R [IFN - CNR and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milano (Italy); Bhaktha, S N B; Mattarelli, M; Montagna, M [Dipartimento di Fisica, CSMFO Lab., Universita di Trento, 38050 Trento (Italy); Turrell, S [Universite des Sciences et Technologies de Lille, Laboratoire de Spectrochimie Infrarouge et Raman, Batiment C5 - UMR CNRS 8516, 59655 Villeneuve d' Ascq cedex (France); Chiappini, A; Chiasera, A; Ferrari, M [CNR-IFN, CSMFO Lab., Via alla Cascata 56/c, 38050 Povo-Trento (Italy); Righini, G C, E-mail: dnrsp@uohyd.ernet.i, E-mail: svrsp@uohyd.ernet.i, E-mail: krishna.vishunubhatla@polimi.i [CNR-IFAC, MDF Lab., Sesto Fiorentino (Firenze) (Italy)

    2009-10-21

    The femtosecond laser direct writing technique was employed to inscribe gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass. Using the butt coupling technique, a systematic study of waveguide loss with respect to input pulse energy and writing speed was performed to achieve the best waveguide with low propagation loss (PL). By pumping at 980 nm, we observed signal enhancement in these active waveguides in the telecom spectral region. The refractive index change was smooth and we estimated it to be {approx}10{sup -3}. The high quantum efficiency ({approx}80%) and a best PL of {approx}0.9 dB cm{sup -1} combined with signal enhancement makes Baccarat glass a potential candidate for application in photonics.

  13. Experimental demonstration of high spectral-efficiency transmission with a novel non-interferometric vector modulator and custom DSP algorithms for coherent PON architectures

    Science.gov (United States)

    Lazarou, I.; Spatharakis, C.; Katopodis, V.; Dris, S.; Bakopoulos, P.; Schrenk, B.; Avramopoulos, H.

    2013-12-01

    We demonstrate a flexible multi-format vector modulator for coherent passive optical network (PON) architectures based on a non-interferometric cascade of a Semiconductor Optical Amplifier (SOA) and an Electro-Absorption Modulator (EAM) that exhibits increased simplicity and high energy-efficiency at low cost. 12- and 16- Quadrature Amplitude Modulation (QAM) constellations are generated, achieving modulation efficiencies of 3.6 and 4 bits/symbol respectively. The presented results demonstrate successful transmission over 25 km of fiber below the Forward Error Correction (FEC) limit, with sufficient compatible loss-budgets, making the proposed modulator concept an attractive candidate for urban network deployments, where high user density demands spectrally efficient formats. In addition, we describe the operation principle of the proposed modulator in detail and finally, the complete set of the digital signal processing (DSP) functionalities and algorithms that follow the standard coherent detection scheme is given, emphasizing on novel methods for QAM signal demodulation with uncommon constellation diagrams.

  14. Digital signal processing laboratory

    CERN Document Server

    Kumar, B Preetham

    2011-01-01

    INTRODUCTION TO DIGITAL SIGNAL PROCESSING Brief Theory of DSP ConceptsProblem SolvingComputer Laboratory: Introduction to MATLAB®/SIMULINK®Hardware Laboratory: Working with Oscilloscopes, Spectrum Analyzers, Signal SourcesDigital Signal Processors (DSPs)ReferencesDISCRETE-TIME LTI SIGNALS AND SYSTEMS Brief Theory of Discrete-Time Signals and SystemsProblem SolvingComputer Laboratory: Simulation of Continuous Time and Discrete-Time Signals and Systems ReferencesTIME AND FREQUENCY ANALYSIS OF COMMUNICATION SIGNALS Brief Theory of Discrete-Time Fourier Transform (DTFT), Discrete Fourier Transform

  15. Multiplexing oscillatory biochemical signals.

    Science.gov (United States)

    de Ronde, Wiet; ten Wolde, Pieter Rein

    2014-04-01

    In recent years it has been increasingly recognized that biochemical signals are not necessarily constant in time and that the temporal dynamics of a signal can be the information carrier. Moreover, it is now well established that the protein signaling network of living cells has a bow-tie structure and that components are often shared between different signaling pathways. Here we show by mathematical modeling that living cells can multiplex a constant and an oscillatory signal: they can transmit these two signals simultaneously through a common signaling pathway, and yet respond to them specifically and reliably. We find that information transmission is reduced not only by noise arising from the intrinsic stochasticity of biochemical reactions, but also by crosstalk between the different channels. Yet, under biologically relevant conditions more than 2 bits of information can be transmitted per channel, even when the two signals are transmitted simultaneously. These observations suggest that oscillatory signals are ideal for multiplexing signals.

  16. Enriching the Hierarchical Model of Achievement Motivation: Autonomous and Controlling Reasons Underlying Achievement Goals

    Science.gov (United States)

    Michou, Aikaterini; Vansteenkiste, Maarten; Mouratidis, Athanasios; Lens, Willy

    2014-01-01

    Background: The hierarchical model of achievement motivation presumes that achievement goals channel the achievement motives of need for achievement and fear of failure towards motivational outcomes. Yet, less is known whether autonomous and controlling reasons underlying the pursuit of achievement goals can serve as additional pathways between…

  17. Efficiency improvements in transport

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Christensen, Linda; Jensen, Thomas C. [Technical Univ. of Denmark. DTU Transport, Kgs. Lyngby (Denmark)

    2012-11-15

    (HEV) has two different power sources: an electric motor and a small combustion engine to extend the operating range. Plug-in hybrid electric vehicles (PHEVs) add the ability to charge the battery from the mains. Many experts see PHEVs as a necessary transition to future EVs. The challenge for transport researchers and professionals will be to achieve dramatic efficiency improvements in modes of transport based on fossil fuels. At the same time it is necessary to promote research and demonstration of new power train technologies which can be used beyond 2050. (LN)

  18. Optical Processing of High Dimensionality Signals

    DEFF Research Database (Denmark)

    Da Ros, Francesco

    signal processing, including wavelength conversion, optical phase conjugation (OPC), and signal regeneration. This project focuses precisely on the applications of OPAs for all-optical signal processing with a two-fold focus: on the one hand, processing the advanced modulation formats required......Optical parametric amplifiers (OPAs) combine high-gain broadband ampli- fication at nearly arbitrary wavelengths with the prospect for achieving an ideally 0-dB noise figure when used in phase-sensitive configuration. Furthermore, several recent demonstrations confirm their potential for alloptical...... demonstrates the potential of phase-insensitive and phase-sensitive parametric processing applied to high-dimensionality modulation formats....

  19. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2003-01-01

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. The amplifier is constructed in a fully differential topology to maximize noise rejection. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved....... A continuous-time current-steering offset-compensation technique is utilized in order to minimize the noise contribution and to minimize dynamic impact on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0...

  20. Multidimensional signal processing for ultrasonic signal classification

    Science.gov (United States)

    Kim, J.; Ramuhalli, P.; Udpa, L.; Udpa, S.

    2001-04-01

    Neural network based signal classification systems are being used increasingly in the analysis of large volumes of data obtained in NDE applications. One example is in the interpretation on ultrasonic signals obtained from inspection of welds where signals can be due to porosity, slag, lack of fusion and cracks in the weld region. Standard techniques rely on differences in individual A-scans to classify the signals. This paper proposes an ultrasonic signal classification technique based on the information in a group of signals and examining the statistical characteristics of the signals. The method was 2-dimensional signal processing algorithms to analyze the information in B- and B'-scan images. In this paper, 2-dimensional transform based coefficients of the images are used as features and a multilayer perceptron is used to classify them. These results are then combined to get the final classification for the inspected region. Results of applying the technique to data obtained from the inspection of welds are presented.

  1. Signal Separation in Ultrasonic Non-Destructive Testing

    OpenAIRE

    V. Matz; M. Kreidl; R. Šmíd

    2007-01-01

    In ultrasonic non-destructive testing the signals characterizing the material structure are commonly evaluated. The sensitivity and resolution of ultrasonic systems is limited by the backscattering and electronic noise level commonly contained in the acquired ultrasonic signals. For this reason, it is very important to use appropriate advanced signal processing methods for noise reduction and signal separation. This paper compares algorithms used for efficient noise reduction in ultrasonic si...

  2. Classification of EMG signals using PSO optimized SVM for diagnosis of neuromuscular disorders.

    Science.gov (United States)

    Subasi, Abdulhamit

    2013-06-01

    Support vector machine (SVM) is an extensively used machine learning method with many biomedical signal classification applications. In this study, a novel PSO-SVM model has been proposed that hybridized the particle swarm optimization (PSO) and SVM to improve the EMG signal classification accuracy. This optimization mechanism involves kernel parameter setting in the SVM training procedure, which significantly influences the classification accuracy. The experiments were conducted on the basis of EMG signal to classify into normal, neurogenic or myopathic. In the proposed method the EMG signals were decomposed into the frequency sub-bands using discrete wavelet transform (DWT) and a set of statistical features were extracted from these sub-bands to represent the distribution of wavelet coefficients. The obtained results obviously validate the superiority of the SVM method compared to conventional machine learning methods, and suggest that further significant enhancements in terms of classification accuracy can be achieved by the proposed PSO-SVM classification system. The PSO-SVM yielded an overall accuracy of 97.41% on 1200 EMG signals selected from 27 subject records against 96.75%, 95.17% and 94.08% for the SVM, the k-NN and the RBF classifiers, respectively. PSO-SVM is developed as an efficient tool so that various SVMs can be used conveniently as the core of PSO-SVM for diagnosis of neuromuscular disorders.

  3. Decomposition of indwelling EMG signals.

    Science.gov (United States)

    Nawab, S Hamid; Wotiz, Robert P; De Luca, Carlo J

    2008-08-01

    Decomposition of indwelling electromyographic (EMG) signals is challenging in view of the complex and often unpredictable behaviors and interactions of the action potential trains of different motor units that constitute the indwelling EMG signal. These phenomena create a myriad of problem situations that a decomposition technique needs to address to attain completeness and accuracy levels required for various scientific and clinical applications. Starting with the maximum a posteriori probability classifier adapted from the original precision decomposition system (PD I) of LeFever and De Luca (25, 26), an artificial intelligence approach has been used to develop a multiclassifier system (PD II) for addressing some of the experimentally identified problem situations. On a database of indwelling EMG signals reflecting such conditions, the fully automatic PD II system is found to achieve a decomposition accuracy of 86.0% despite the fact that its results include low-amplitude action potential trains that are not decomposable at all via systems such as PD I. Accuracy was established by comparing the decompositions of indwelling EMG signals obtained from two sensors. At the end of the automatic PD II decomposition procedure, the accuracy may be enhanced to nearly 100% via an interactive editor, a particularly significant fact for the previously indecomposable trains.

  4. Surface electromyography signal processing and classification techniques.

    Science.gov (United States)

    Chowdhury, Rubana H; Reaz, Mamun B I; Ali, Mohd Alauddin Bin Mohd; Bakar, Ashrif A A; Chellappan, K; Chang, T G

    2013-09-17

    Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above.

  5. Signal Classification for Acoustic Neutrino Detection

    CERN Document Server

    Neff, M; Enzenhöfer, A; Graf, K; Hößl, J; Katz, U; Lahmann, R; Richardt, C

    2011-01-01

    This article focuses on signal classification for deep-sea acoustic neutrino detection. In the deep sea, the background of transient signals is very diverse. Approaches like matched filtering are not sufficient to distinguish between neutrino-like signals and other transient signals with similar signature, which are forming the acoustic background for neutrino detection in the deep-sea environment. A classification system based on machine learning algorithms is analysed with the goal to find a robust and effective way to perform this task. For a well-trained model, a testing error on the level of one percent is achieved for strong classifiers like Random Forest and Boosting Trees using the extracted features of the signal as input and utilising dense clusters of sensors instead of single sensors.

  6. Surface Electromyography Signal Processing and Classification Techniques

    Directory of Open Access Journals (Sweden)

    Tae G. Chang

    2013-09-01

    Full Text Available Electromyography (EMG signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above.

  7. Surface Electromyography Signal Processing and Classification Techniques

    Science.gov (United States)

    Chowdhury, Rubana H.; Reaz, Mamun B. I.; Ali, Mohd Alauddin Bin Mohd; Bakar, Ashrif A. A.; Chellappan, Kalaivani; Chang, Tae. G.

    2013-01-01

    Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above. PMID:24048337

  8. Signal classification for acoustic neutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Neff, M., E-mail: max.neff@physik.uni-erlangen.de [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anton, G.; Enzenhoefer, A.; Graf, K.; Hoessl, J.; Katz, U.; Lahmann, R.; Richardt, C. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

    2012-01-11

    This article focuses on signal classification for deep-sea acoustic neutrino detection. In the deep sea, the background of transient signals is very diverse. Approaches like matched filtering are not sufficient to distinguish between neutrino-like signals and other transient signals with similar signature, which are forming the acoustic background for neutrino detection in the deep-sea environment. A classification system based on machine learning algorithms is analysed with the goal to find a robust and effective way to perform this task. For a well-trained model, a testing error on the level of 1% is achieved for strong classifiers like Random Forest and Boosting Trees using the extracted features of the signal as input and utilising dense clusters of sensors instead of single sensors.

  9. Mind the gap. Quantifying principal-agent problems in energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-10-15

    Energy efficiency presents a unique opportunity to address three energy-related challenges in IEA member countries: energy security, climate change, and economic development. Yet an energy-efficiency gap exists between actual and optimal energy use. That is, significant cost-effective energy efficiency potential is wasted because market barriers prevent countries from achieving optimal levels. Market barriers take many forms, from inadequate access to capital, isolation from price signals, information asymmetry, and split-incentives. Though many studies have reported the existence of such market barriers, none so far have attempted to quantify the magnitude of their effect on energy use and efficiency. This publication is an unprecedented attempt to quantify the size of one of the most pervasive barriers to energy efficiency - principal-agent problems, or in common parlance, variations on the 'landlord-tenant' problem. In doing so, the book provides energy analysts and economists with unique insights into the amount of energy affected by principal-agent problems. Using an innovative methodology applied to eight case studies (covering commercial and residential sectors, and end-use appliances) from five different IEA countries, the analysis identifies over 3,800 PJ/year of affected energy use - that is, around 85% of the annual energy use of a country the size of Spain. The book builds on these findings to suggest a range of possible policy solutions that can reduce the impact of principal-agent problems and help policy makers mind the energy efficiency gap.

  10. gTBS: A green Task-Based Sensing for energy efficient Wireless Sensor Networks

    KAUST Repository

    Alhalafi, Abdullah

    2016-09-08

    Wireless sensor networks (WSN) are widely used to sense and measure physical conditions for different purposes and within different regions. However due to the limited lifetime of the sensor\\'s energy source, many efforts are made to design energy efficient WSN. As a result, many techniques were presented in the literature such as power adaptation, sleep and wake-up, and scheduling in order to enhance WSN lifetime. These techniques where presented separately and shown to achieve some gain in terms of energy efficiency. In this paper, we present an energy efficient cross layer design for WSN that we named \\'green Task-Based Sensing\\' (gTBS) scheme. The gTBS design is a task based sensing scheme that not only prevents wasting power in unnecessary signaling, but also utilizes several techniques for achieving reliable and energy efficient WSN. The proposed gTBS combines the power adaptation with a sleep and wake-up technique that allows inactive nodes to sleep. Also, it adopts a gradient-oriented unicast approach to overcome the synchronization problem, minimize network traffic hurdles, and significantly reduce the overall power consumption of the network. We implement the gTBS on a testbed and we show that it reduces the power consumption by a factor of 20%-55% compared to traditional TBS. It also reduces the delay by 54%-145% and improves the delivery ratio by 24%-73%. © 2016 IEEE.

  11. Optimal BLS: Optimizing transit-signal detection for Keplerian dynamics

    Science.gov (United States)

    Ofir, Aviv

    2015-08-01

    Transit surveys, both ground- and space-based, have already accumulated a large number of light curves that span several years. We optimize the search for transit signals for both detection and computational efficiencies by assuming that the searched systems can be described by Keplerian, and propagating the effects of different system parameters to the detection parameters. Importnantly, we mainly consider the information content of the transit signal and not any specific algorithm - and use BLS (Kovács, Zucker, & Mazeh 2002) just as a specific example.We show that the frequency information content of the light curve is primarily determined by the duty cycle of the transit signal, and thus the optimal frequency sampling is found to be cubic and not linear. Further optimization is achieved by considering duty-cycle dependent binning of the phased light curve. By using the (standard) BLS, one is either fairly insensitive to long-period planets or less sensitive to short-period planets and computationally slower by a significant factor of ~330 (for a 3 yr long dataset). We also show how the physical system parameters, such as the host star's size and mass, directly affect transit detection. This understanding can then be used to optimize the search for every star individually.By considering Keplerian dynamics explicitly rather than implicitly one can optimally search the transit signal parameter space. The presented Optimal BLS enhances the detectability of both very short and very long period planets, while allowing such searches to be done with much reduced resources and time. The Matlab/Octave source code for Optimal BLS is made available.

  12. A New Achievability Scheme for the Relay Channel

    CERN Document Server

    Kang, Wei

    2007-01-01

    In this paper, we propose a new coding scheme for the general relay channel. This coding scheme is in the form of a block Markov code. The transmitter uses a superposition Markov code. The relay compresses the received signal and maps the compressed version of the received signal into a codeword conditioned on the codeword of the previous block. The receiver performs joint decoding after it has received all of the B blocks. We show that this coding scheme can be viewed as a generalization of the well-known Compress-And-Forward (CAF) scheme proposed by Cover and El Gamal. Our coding scheme provides options for preserving the correlation between the channel inputs of the transmitter and the relay, which is not possible in the CAF scheme. Thus, our proposed scheme may potentially yield a larger achievable rate than the CAF scheme.

  13. Teaching Low-Achieving Students to Self-Regulate Persuasive Quick Write Responses

    Science.gov (United States)

    Mason, Linda H.; Benedek-Wood, Elizabeth; Valasa, Lauren

    2009-01-01

    Students' academic achievement across content areas is often dependent on their ability to express knowledge through written expression. Many adolescent students lack the skills to write efficiently and effectively. These low-achieving writers can benefit from instruction in self-regulating the writing process. One approach, Self-Regulated…

  14. Achievable Rates for Two-Way Wire-Tap Channels

    CERN Document Server

    Tekin, Ender

    2007-01-01

    We consider two-way wire-tap channels, where two users are communicating with each other in the presence of an eavesdropper, who has access to the communications through a multiple-access channel. We find achievable rates for two different scenarios, the Gaussian two-way wire-tap channel, (GTW-WT), and the binary additive two-way wire-tap channel, (BATW-WT). It is shown that the two-way channels inherently provide a unique advantage for wire-tapped scenarios, as the users know their own transmitted signals and in effect help encrypt the other user's messages, similar to a one-time pad. We compare the achievable rates to that of the Gaussian multiple-access wire-tap channel (GMAC-WT) to illustrate this advantage.

  15. Applying a non-parametric efficiency analysis to measure conversion efficiency in Great Britain

    NARCIS (Netherlands)

    Binder, M.; Broekel, T.

    2011-01-01

    In the literature on Sen's capability approach, studies focusing on the empirical measurement of conversion factors are comparatively rare. We add to this field by adopting a measure of 'conversion efficiency' that captures the efficiency with which individuals convert their resources into achieved

  16. A nonlinear optoelectronic filter for electronic signal processing

    Science.gov (United States)

    Loh, William; Yegnanarayanan, Siva; Ram, Rajeev J.; Juodawlkis, Paul W.

    2014-01-01

    The conversion of electrical signals into modulated optical waves and back into electrical signals provides the capacity for low-loss radio-frequency (RF) signal transfer over optical fiber. Here, we show that the unique properties of this microwave-photonic link also enable the manipulation of RF signals beyond what is possible in conventional systems. We achieve these capabilities by realizing a novel nonlinear filter, which acts to suppress a stronger RF signal in the presence of a weaker signal independent of their separation in frequency. Using this filter, we demonstrate a relative suppression of 56 dB for a stronger signal having a 1-GHz center frequency, uncovering the presence of otherwise undetectable weaker signals located as close as 3.5 Hz away. The capabilities of the optoelectronic filter break the conventional limits of signal detection, opening up new possibilities for radar and communication systems, and for the field of precision frequency metrology. PMID:24402418

  17. Multimedia signal coding and transmission

    CERN Document Server

    Ohm, Jens-Rainer

    2015-01-01

    This textbook covers the theoretical background of one- and multidimensional signal processing, statistical analysis and modelling, coding and information theory with regard to the principles and design of image, video and audio compression systems. The theoretical concepts are augmented by practical examples of algorithms for multimedia signal coding technology, and related transmission aspects. On this basis, principles behind multimedia coding standards, including most recent developments like High Efficiency Video Coding, can be well understood. Furthermore, potential advances in future development are pointed out. Numerous figures and examples help to illustrate the concepts covered. The book was developed on the basis of a graduate-level university course, and most chapters are supplemented by exercises. The book is also a self-contained introduction both for researchers and developers of multimedia compression systems in industry.

  18. Optimal signal patterns for dynamical cellular communication

    CERN Document Server

    Hasegawa, Yoshihiko

    2015-01-01

    Cells transmit information via signaling pathways, using temporal dynamical patterns. As optimality with respect to environments is the universal principle in biological systems, organisms have acquired an optimal way of transmitting information. Here we obtain optimal dynamical signal patterns which can transmit information efficiently (low power) and reliably (high accuracy) using the optimal control theory. Adopting an activation-inactivation decoding network, we reproduced several dynamical patterns found in actual signals, such as steep, gradual and overshooting dynamics. Notably, when minimizing the power of the input signal, optimal signals exhibit the overshooting pattern, which is a biphasic pattern with transient and steady phases; this pattern is prevalent in actual dynamical patterns as it can be generated by an incoherent feed-forward loop (FFL), a common motif in biochemical networks. We also identified conditions when the three patterns, steep, gradual and overshooting, confer advantages.

  19. Three brief assessments of math achievement.

    Science.gov (United States)

    Steiner, Eric T; Ashcraft, Mark H

    2012-12-01

    Because of wide disparities in college students' math knowledge-that is, their math achievement-studies of cognitive processing in math tasks also need to assess their individual level of math achievement. For many research settings, however, using existing math achievement tests is either too costly or too time consuming. To solve this dilemma, we present three brief tests of math achievement here, two drawn from the Wide Range Achievement Test and one composed of noncopyrighted items. All three correlated substantially with the full achievement test and with math anxiety, our original focus, and all show acceptable to excellent reliability. When lengthy testing is not feasible, one of these brief tests can be substituted.

  20. Optimization of energy efficiency for the full-duplex massive MIMO systems

    Institute of Scientific and Technical Information of China (English)

    Xinhua Wang; Ju Liu; Chao Zhai; Pengbo Xing; Lina Zheng

    2016-01-01

    The energy efficiency (EE) for the ful-duplex mas-sive multi-input multi-output (MIMO) system is investigated. Given the transmit powers of both the uplink and the downlink, the closed-form solutions of the optimal number of antennas and the maximum EE are achieved in the high regime of the signal-to-noise ratio (SNR). It is shown that the optimal num-ber of antennas and the maximum EE gets larger with the increase in user numbers. To further improve the EE, an op-timization algorithm with low complexity is proposed to jointly determine the number of antennas and the transmit powers of both the uplink and the downlink. It is shown that, the pro-posed algorithm can achieve the system performance very close to the exhaustive search.

  1. Dynamic optimization of distributed biological systems using robust and efficient numerical techniques

    Directory of Open Access Journals (Sweden)

    Vilas Carlos

    2012-07-01

    Full Text Available Abstract Background Systems biology allows the analysis of biological systems behavior under different conditions through in silico experimentation. The possibility of perturbing biological systems in different manners calls for the design of perturbations to achieve particular goals. Examples would include, the design of a chemical stimulation to maximize the amplitude of a given cellular signal or to achieve a desired pattern in pattern formation systems, etc. Such design problems can be mathematically formulated as dynamic optimization problems which are particularly challenging when the system is described by partial differential equations. This work addresses the numerical solution of such dynamic optimization problems for spatially distributed biological systems. The usual nonlinear and large scale nature of the mathematical models related to this class of systems and the presence of constraints on the optimization problems, impose a number of difficulties, such as the presence of suboptimal solutions, which call for robust and efficient numerical techniques. Results Here, the use of a control vector parameterization approach combined with efficient and robust hybrid global optimization methods and a reduced order model methodology is proposed. The capabilities of this strategy are illustrated considering the solution of a two challenging problems: bacterial chemotaxis and the FitzHugh-Nagumo model. Conclusions In the process of chemotaxis the objective was to efficiently compute the time-varying optimal concentration of chemotractant in one of the spatial boundaries in order to achieve predefined cell distribution profiles. Results are in agreement with those previously published in the literature. The FitzHugh-Nagumo problem is also efficiently solved and it illustrates very well how dynamic optimization may be used to force a system to evolve from an undesired to a desired pattern with a reduced number of actuators. The presented

  2. Predicting Academic Achievement from Classroom Behaviors

    OpenAIRE

    Flynt, Cynthia J.

    2008-01-01

    PREDICTING ACADEMIC ACHIEVEMENT FROM CLASSROOM BEHAVIORS by Cynthia J. Flynt Nancy Bodenhorn & Kusum Singh, Co-Chairs Counselor Education (ABSTRACT) This study examined the influence of behaviors exhibited in the classroom on reading and math achievement in the first, third and eighth grades; and the influence of teacher perceptions on reading and math achievement of African-Americans versus White students and male versus female students. Lastly, the study examined te...

  3. Cognitive abilities, sociocultural background and academic achievement

    OpenAIRE

    Diniz, António; Pocinho, Margarida Maria Ferreira Diogo Dias; Almeida,Leandro Silva

    2011-01-01

    The infl uence of students’ sociocultural background on academic achievement is a well established fact. Research also points out that sociocultural background is related to students’ cognitive abilities and these have an effect on their academic achievement. However, the mediator role of cognitive abilities on the relationship between sociocultural background and academic achievement is less well known. A structural equation model that represents these relationships was tested in a sample...

  4. Cell signaling review series

    Institute of Scientific and Technical Information of China (English)

    Aiming Lin; Zhenggang Liu

    2008-01-01

    @@ Signal transduction is pivotal for many, if not all, fundamental cellular functions including proliferation, differentiation, transformation and programmed cell death. Deregulation of cell signaling may result in certain types of cancers and other human diseases.

  5. Retinoid signalling during embryogenesis

    NARCIS (Netherlands)

    Pijnappel, W.W.M.; Hendriks, H.F.J.; Durston, A.J.

    1996-01-01

    Conclusion: Retinoids are suspected to have multiple functions during embryogenesis, which are carried out via various different signal transduction pathways involving active retinoids and nuclear retinoid receptors. Research focuses on the identification of the retinoid signal transduction componen

  6. Improving efficiency in meat production.

    Science.gov (United States)

    Brameld, John M; Parr, Tim

    2016-08-01

    Selective breeding and improved nutritional management over the past 20-30 years has resulted in dramatic improvements in growth efficiency for pigs and poultry, particularly lean tissue growth. However, this has been achieved using high-quality feed ingredients, such as wheat and soya that are also used for human consumption and more recently biofuels production. Ruminants on the other hand are less efficient, but are normally fed poorer quality ingredients that cannot be digested by human subjects, such as grass or silage. The challenges therefore are to: (i) maintain the current efficiency of growth of pigs and poultry, but using more ingredients not needed to feed the increasing human population or for the production of biofuels; (ii) improve the efficiency of growth in ruminants; (iii) at the same time produce animal products (meat, milk and eggs) of equal or improved quality. This review will describe the use of: (a) enzyme additives for animal feeds, to improve feed digestibility; (b) known growth promoting agents, such as growth hormone, β-agonists and anabolic steroids, currently banned in the European Union but used in other parts of the world; (c) recent transcriptomic studies into molecular mechanisms for improved growth efficiency via low residual feed intake. In doing so, the use of genetic manipulation in animals will also be discussed.

  7. Mobilising Investment in Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Taxes, loans and grants, trading schemes and white certificates, public procurement and investment in R&D or infrastructure: known collectively as 'economic instruments', these tools can be powerful means of mobilising the finances needed to achieve policy goals by implementing energy efficiency measures. The role of economic instruments is to kick-start the private financial markets and to motivate private investors to fund EE measures. They should reinforce and promote energy performance regulations. This IEA analysis addresses the fact that, to date, relatively little effort has been directed toward evaluating how well economic instruments work. Using the buildings sector to illustrate how such measures can support energy efficiency, this paper can help policy makers better select and design economic instruments appropriate to their policy objectives and national contexts. This report’s three main aims are to: 1) Examine how economic instruments are currently used in energy efficiency policy; 2) Consider how economic instruments can be more effective and efficient in supporting low-energy buildings; and 3) Assess how economic instruments should be funded, where public outlay is needed. Detailed case studies in this report assess examples of economic instruments for energy efficiency in the buildings sector in Canada (grants), France (tax relief and loans), Germany (loans and grants), Ireland (grants) and Italy (white certificates and tax relief).

  8. Biomedical signal processing

    CERN Document Server

    Akay, Metin

    1994-01-01

    Sophisticated techniques for signal processing are now available to the biomedical specialist! Written in an easy-to-read, straightforward style, Biomedical Signal Processing presents techniques to eliminate background noise, enhance signal detection, and analyze computer data, making results easy to comprehend and apply. In addition to examining techniques for electrical signal analysis, filtering, and transforms, the author supplies an extensive appendix with several computer programs that demonstrate techniques presented in the text.

  9. Danger signals in stroke.

    Science.gov (United States)

    Gelderblom, Mathias; Sobey, Christopher G; Kleinschnitz, Christoph; Magnus, Tim

    2015-11-01

    Danger molecules are the first signals released from dying tissue after stroke. These danger signals bind to receptors on immune cells that will result in their activation and the release of inflammatory and neurotoxic mediators, resulting in amplification of the immune response and subsequent enlargement of the damaged brain volume. The release of danger signals is a central event that leads to a multitude of signals and cascades in the affected and neighbouring tissue, therefore providing a potential target for therapy.

  10. Tetrapyrrole Signaling in Plants

    Science.gov (United States)

    Larkin, Robert M.

    2016-01-01

    Tetrapyrroles make critical contributions to a number of important processes in diverse organisms. In plants, tetrapyrroles are essential for light signaling, the detoxification of reactive oxygen species, the assimilation of nitrate and sulfate, respiration, photosynthesis, and programed cell death. The misregulation of tetrapyrrole metabolism can produce toxic reactive oxygen species. Thus, it is not surprising that tetrapyrrole metabolism is strictly regulated and that tetrapyrrole metabolism affects signaling mechanisms that regulate gene expression. In plants and algae, tetrapyrroles are synthesized in plastids and were some of the first plastid signals demonstrated to regulate nuclear gene expression. In plants, the mechanism of tetrapyrrole-dependent plastid-to-nucleus signaling remains poorly understood. Additionally, some of experiments that tested ideas for possible signaling mechanisms appeared to produce conflicting data. In some instances, these conflicts are potentially explained by different experimental conditions. Although the biological function of tetrapyrrole signaling is poorly understood, there is compelling evidence that this signaling is significant. Specifically, this signaling appears to affect the accumulation of starch and may promote abiotic stress tolerance. Tetrapyrrole-dependent plastid-to-nucleus signaling interacts with a distinct plastid-to-nucleus signaling mechanism that depends on GENOMES UNCUOPLED1 (GUN1). GUN1 contributes to a variety of processes, such as chloroplast biogenesis, the circadian rhythm, abiotic stress tolerance, and development. Thus, the contribution of tetrapyrrole signaling to plant function is potentially broader than we currently appreciate. In this review, I discuss these aspects of tetrapyrrole signaling.

  11. Exceeding the Carnot efficiency

    Science.gov (United States)

    Ng, Nelly Huei Ying; Woods, Mischa; Wehner, Stephanie

    A suitable way of quantifying work for microscopic quantum systems has been constantly debated in the field of quantum thermodynamics. One natural approach is to measure the average increase in energy of an ancillary system, called the battery, after a work extraction protocol. The quality of work extracted is usually argued to be good by quantifying higher moments of the energy distribution, or by restricting the amount of entropy to be low. This limits the amount of heat contribution to the energy extracted, but does not completely prevent it. We show that if one allows for a definition of work that tolerates a non-negligible entropy increase in the battery, then a small scale heat engine (with a similar set up to that of arXiv:1506.02322) can possibly exceed the Carnot efficiency. This can be done without using any additional resources such as coherence or correlations, and furthermore can be achieved by using finite-size quantum heat baths as well.

  12. HAND-HELD GAMMA-RAY SPECTROMETER BASED ON HIGH-EFFICIENCY FRISCH-RING CdZnTe DETECTORS.

    Energy Technology Data Exchange (ETDEWEB)

    CUI,Y.

    2007-05-01

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution, el% FWHM at 662 keV, and good efficiency for detecting gamma rays. This technique facilitates the application of CdZnTe materials for high efficiency gamma-ray detection. A hand-held gamma-ray spectrometer based on Frisch-ring detectors is being designed at Brookhaven National Laboratory. It employs an 8x8 CdZnTe detector array to achieve a high volume of 19.2 cm3, so that detection efficiency is significantly improved. By using the front-end ASICs developed at BNL, this spectrometer has a small profile and high energy resolution. The spectrometer includes signal processing circuit, digitization and storage circuit, high-voltage module, and USB interface. In this paper, we introduce the details of the system structure and report our test results with it.

  13. Achievement Goals and Discrete Achievement Emotions: A Theoretical Model and Prospective Test

    Science.gov (United States)

    Pekrun, Reinhard; Elliot, Andrew J.; Maier, Markus A.

    2006-01-01

    A theoretical model linking achievement goals to discrete achievement emotions is proposed. The model posits relations between the goals of the trichotomous achievement goal framework and 8 commonly experienced achievement emotions organized in a 2 (activity/outcome focus) x 2 (positive/negative valence) taxonomy. Two prospective studies tested…

  14. Performance Evaluation of the New Compound-Carrier-Modulated Signal for Future Navigation Signals

    Directory of Open Access Journals (Sweden)

    Ruidan Luo

    2016-01-01

    Full Text Available Navigation Signal based on Compound Carrier (NSCC, is proposed as the potential future global navigation satellite system (GNSS signal modulation scheme. NSCC, a kind of multi-carrier (MC signal, is generated by superposition and multi-parameter adjustment of sub-carriers. Therefore, a judious choice of parameter configation is needed. The main objective of this paper is to investigate the performance of the NSCC which is influenced by these parameters and to demonstrate its structure characteristics and superiority, employing a comprehensive evaluation system. The results show that the proposed NSCC signal processes full spectral efficiency and limited out of band (OOB emissions, satisfying the demands of crowed frequency resources. It also presents better performance in terms of spectral separation coefficients (SSCs, tracking accuracy, multipath mitigation capability and anti-jamming reduction compared with the legacy navigation signals. NSCC modulation represents a serious candidate for navigation satellite augmentation systems, especially for signals applied in challenging environments.

  15. FIPSER: Performance study of a readout concept with few digitization levels for fast signals

    Science.gov (United States)

    Limyansky, B.; Reese, R.; Cressler, J. D.; Otte, A. N.; Taboada, I.; Ulusoy, C.

    2016-11-01

    We discuss the performance of a readout system, Fixed Pulse Shape Efficient Readout (FIPSER), to digitize signals from detectors with a fixed pulse shape. In this study we are mainly interested in the readout of fast photon detectors like photomultipliers or Silicon photomultipliers. But the concept can be equally applied to the digitization of other detector signals. FIPSER is based on the flash analog to digital converter (FADC) concept, but has the potential to lower costs and power consumption by using an order of magnitude fewer discrete voltage levels. Performance is bolstered by combining the discretized signal with the knowledge of the underlying pulse shape. Simulated FIPSER data was reconstructed with two independent methods. One using a maximum likelihood method and the other using a modified χ2 test. Both methods show that utilizing 12 discrete voltage levels with a sampling rate of 4 samples per full width half maximum (FWHM) of the pulse achieves an amplitude resolution that is better than the Poisson limit for photon-counting experiments. The time resolution achieved in this configuration ranges between 0.02 and 0.16 FWHM and depends on the pulse amplitude. In a situation where the waveform is composed of two consecutive pulses the pulses can be separated if they are at least 0.05-0.30 FWHM apart with an amplitude resolution that is better than 20%.

  16. Linear signal processing using silicon micro-ring resonators

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Ding, Yunhong; Ou, Haiyan;

    2012-01-01

    We review our recent achievements on the use of silicon micro-ring resonators for linear optical signal processing applications, including modulation format conversion, phase-to-intensity modulation conversion and waveform shaping....

  17. On the bi-dimensional variational decomposition applied to nonstationary vibration signals for rolling bearing crack detection in coal cutters

    Science.gov (United States)

    Jiang, Yu; Li, Zhixiong; Zhang, Chao; Hu, Chao; Peng, Z.

    2016-06-01

    This work aims to detect rolling bearing cracks using a variational approach. An original method that appropriately incorporates bi-dimensional variational mode decomposition (BVMD) into discriminant diffusion maps (DDM) is proposed to analyze the nonstationary vibration signals recorded from the cracked rolling bearings in coal cutters. The advantage of this variational decomposition based diffusion map (VDDM) method in comparison to the current DDM is that the intrinsic vibration mode of the crack can be filtered into a limited bandwidth in the frequency domain with an estimated central frequency, thus discarding the interference signal components in the vibration signals and significantly improving the crack detection performance. In addition, the VDDM is able to simultaneously process two-channel sensor signals to reduce information leakage. Experimental validation using rolling bearing crack vibration signals demonstrates that the VDDM separated the raw signals into four intrinsic modes, including one roller vibration mode, one roller cage vibration mode, one inner race vibration mode, and one outer race vibration mode. Hence, reliable fault features were extracted from the outer race vibration mode, and satisfactory crack identification performance was achieved. The comparison between the proposed VDDM and existing approaches indicated that the VDDM method was more efficient and reliable for crack detection in coal cutter rolling bearings. As an effective catalyst for rolling bearing crack detection, this newly proposed method is useful for practical applications.

  18. Viability of Controlling Prosthetic Hand Utilizing Electroencephalograph (EEG) Dataset Signal

    Science.gov (United States)

    Miskon, Azizi; A/L Thanakodi, Suresh; Raihan Mazlan, Mohd; Mohd Haziq Azhar, Satria; Nooraya Mohd Tawil, Siti

    2016-11-01

    This project presents the development of an artificial hand controlled by Electroencephalograph (EEG) signal datasets for the prosthetic application. The EEG signal datasets were used as to improvise the way to control the prosthetic hand compared to the Electromyograph (EMG). The EMG has disadvantages to a person, who has not used the muscle for a long time and also to person with degenerative issues due to age factor. Thus, the EEG datasets found to be an alternative for EMG. The datasets used in this work were taken from Brain Computer Interface (BCI) Project. The datasets were already classified for open, close and combined movement operations. It served the purpose as an input to control the prosthetic hand by using an Interface system between Microsoft Visual Studio and Arduino. The obtained results reveal the prosthetic hand to be more efficient and faster in response to the EEG datasets with an additional LiPo (Lithium Polymer) battery attached to the prosthetic. Some limitations were also identified in terms of the hand movements, weight of the prosthetic, and the suggestions to improve were concluded in this paper. Overall, the objective of this paper were achieved when the prosthetic hand found to be feasible in operation utilizing the EEG datasets.

  19. DESI systems engineering: throughput and signal-to-noise

    Science.gov (United States)

    Besuner, Robert W.; Sholl, Michael J.

    2016-08-01

    The Dark Energy Spectroscopic Instrument (DESI) is a fiber-fed multi-object spectroscopic instrument under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. Management of light throughput and noise in all elements of the instrument is key to achieving the high-level DESI science requirements over the planned survey area and depth within the planned survey duration. The DESI high-level science requirements flow down to instrument performance requirements on system throughput and operational efficiency. Signal-to-noise requirements directly affect minimum required exposure time per field, which dictates the pace and duration of the entire survey. The need to maximize signal (light throughput) and to minimize noise contributions and time overhead due to reconfigurations between exposures drives the instrument subsystem requirements and technical implementation. Throughput losses, noise contributors, and interexposure reconfiguration time are budgeted, tracked, and managed as DESI Systems Engineering resources. Current best estimates of throughput losses and noise contributions from each individual element of the instrument are tracked together in a master budget to calculate overall margin on completing the survey within the allotted time. That budget is a spreadsheet accessible to the entire DESI project.

  20. Development of signal processing system of avalanche photo diode for space observations by Astro-H

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, M., E-mail: ohno@hep01.hepl.hiroshima-u.ac.jp [Department of Physical Sciences, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8516 (Japan); Goto, K.; Hanabata, Y.; Takahashi, H.; Fukazawa, Y. [Department of Physical Sciences, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8516 (Japan); Yoshino, M.; Saito, T.; Nakamori, T.; Kataoka, J. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Sasano, M.; Torii, S.; Uchiyama, H.; Nakazawa, K. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Watanabe, S.; Kokubun, M.; Ohta, M.; Sato, T.; Takahashi, T. [Institute of Space and Astronautial Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku Sagamihara, Kanagawa 252-5120 (Japan); Tajima, H. [Cosmic-ray Research Facility, Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2013-01-21

    Astro-H is the sixth Japanese X-ray space observatory which will be launched in 2014. Two of onboard instruments of Astro-H, Hard X-ray Imager and Soft Gamma-ray Detector are surrounded by many number of large Bismuth Germanate (Bi{sub 4}Ge{sub 3}O{sub 12}; BGO) scintillators. Optimum readout system of scintillation lights from these BGOs are essential to reduce the background signals and achieve high performance for main detectors because most of gamma-rays from out of field-of-view of main detectors or radio-isotopes produced inside them due to activation can be eliminated by anti-coincidence technique using BGO signals. We apply Avalanche Photo Diode (APD) for light sensor of these BGO detectors since their compactness and high quantum efficiency make it easy to design such large number of BGO detector system. For signal processing from APDs, digital filter and other trigger logics on the Field-Programmable Gate Array (FPGA) is used instead of discrete analog circuits due to limitation of circuit implementation area on spacecraft. For efficient observations, we have to achieve as low threshold of anti-coincidence signal as possible by utilizing the digital filtering. In addition, such anti-coincident signals should be sent to the main detector within 5μs to make it in time to veto the A–D conversion. Considering this requirement and constraint from logic size of FPGA, we adopt two types of filter, 8 delay taps filter with only 2 bit precision coefficient and 16 delay taps filter with 8 bit precision coefficient. The data after former simple filter provides anti-coincidence signal quickly in orbit, and the latter filter is used for detail analysis after the data is down-linked. -- Highlights: ► We develop digital signal processing system of APD for Astro-H. ► We apply two types of digital filter instead of discrete analog circuit. ► By optimization, comparable or better energy threshold to analog shaper is archived. ► Developed digital filter works

  1. Acoustic Signals and Systems

    DEFF Research Database (Denmark)

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...

  2. Multimedia Technology and Students' Achievement in Geography

    Science.gov (United States)

    DaSilva, Edmar Bernardes; Kvasnak, Robb Neil

    2012-01-01

    In this study done at a community college in South Florida, the achievements of students who spoke English as their second language who had attended their K-12 education outside the United States in their home countries, in a U.S. college course on world geography are compared with the achievements of students in the same classes who spoke English…

  3. Achievement and Its Correlates: Symposium III A.

    Science.gov (United States)

    Ismail, Maznah; And Others

    This symposium contains a report of a study which (1) examined the relationship between Malaysian children's perception of control and their academic achievement, by Maznah Ismail and Choo Piang Foong, and two abstracts of studies which (2) investigated achievement motivation and attribution of success in rural and urban Malaysian ethnic groups,…

  4. Professional Learning Communities Impact on Student Achievement

    Science.gov (United States)

    Hamilton, Jan L.

    2013-01-01

    This study examined the impact of the Professional Learning Community model on student achievement in the state of California. Specifically, the study compared student achievement between two school types: Professional Learning Community schools and Non Professional Learning schools. The research utilized existing API scores for California schools…

  5. Physical Environment and Middle Grade Achievement.

    Science.gov (United States)

    Chan, Tak Cheung

    This study measured the influence of air conditioning, carpeting, fluorescent lighting, and interior pastel coloring on the academic achievement of eighth grade Georgia pupils in 1975-76 when the variance due to socioeconomic status was statistically controlled. Analysis of covariance was used to compare the achievement scores of students on the…

  6. Health and Nutrition: Preconditions for Educational Achievement.

    Science.gov (United States)

    Negussie, Birgit

    This paper discusses the importance of maternal and infant health for children's educational achievement. Education, health, and nutrition are so closely related that changes in one causes changes in the others. Improvement of maternal and preschooler health and nutrition is a precondition for improved educational achievement. Although parental…

  7. Achieving scale strategies for sustained competitive performance.

    Science.gov (United States)

    Grube, Mark E; Gish, Ryan S; Tkach, Sasha N

    2008-05-01

    Growth to achieve scale requires the following strategic initiatives: Having a clear understanding of what the organization is and what it wants to become. Ensuring a structured and rigorous growth process. Leveraging size to achieve benefits of scale. Recognizing the importance of physicians, ambulatory care, and primary care. Establishing and maintaining accountability as growth occurs.

  8. Psychological Adjustment and Academic Achievement among Adolescents

    Science.gov (United States)

    Mahmood, Khalid; Iqbal, Muhammad Maqsood

    2015-01-01

    This study was studied that emotional and behavioural problems of young students who are directly related to their academic achievement and thus play a vital role in the development of young learners carrier. This study helped to fill a gap by conducting an exploration of psychological adjustment and academic achievement among adolescents. It also…

  9. Achieve inventory reduction and improve customer service?

    Science.gov (United States)

    Moody, M C

    2000-05-01

    Is it really possible to achieve significant reductions in your manufacturing inventories while improving customer service? If you really want to achieve significant inventory reductions, focus on the root causes, and develop countermeasures and a work plan, to execute your countermeasures. Include measurements for recording your progress, and deploy your countermeasures until they are no longer required, or until new ones are needed.

  10. A Multivariate Model of Achievement in Geometry

    Science.gov (United States)

    Bailey, MarLynn; Taasoobshirazi, Gita; Carr, Martha

    2014-01-01

    Previous studies have shown that several key variables influence student achievement in geometry, but no research has been conducted to determine how these variables interact. A model of achievement in geometry was tested on a sample of 102 high school students. Structural equation modeling was used to test hypothesized relationships among…

  11. Fault Management for Efficient Data Gathering in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    M.Y. Mohamed Yacoab

    2012-12-01

    Full Text Available Wireless Sensor Networks (WSNs are naturally fault-prone owing to the common wireless communication medium, severe developed environments and resources limitation. In data gathering, node and network failures are common in WSNs. It is also essential for the WSN to be able to detect faults early and establish revival actions in order to avoid ruin of service due to faults. In this study we propose a fault management scheme which can efficiently gather data in wireless sensor networks. Our fault management scheme is capable of detecting network faults and node faults along with fault recovery. Initially, we assign some nodes as Reliable nodes (R nodes in the data aggregation tree, to perform accurate fault discovery and recovery. These R nodes collects the details of residual battery power and signal strength of all intermediate nodes. Node faults are detected by comparing the data values of each node with its neighbor and link failure are detected by estimating the Signal to Noise Ratio (SNR and Link Quality Indicator (LQI. In case of any link failure in the network, the succeeding R node will send a failure warning message to the previous R node and will then try to forward the packet to the next R node via an alternate path. By simulation results, we show that our proposed technique achieves good packet delivery ratio with reduced energy consumption and delay.

  12. Efficient and robust ventricular tachycardia and fibrillation detection method for wearable cardiac health monitoring devices.

    Science.gov (United States)

    Prabhakararao, Eedara; Manikandan, M Sabarimalai

    2016-09-01

    In this Letter, the authors propose an efficient and robust method for automatically determining the VT and VF events in the electrocardiogram (ECG) signal. The proposed method consists of: (i) discrete cosine transform (DCT)-based noise suppression; (ii) addition of bipolar sequence of amplitudes with alternating polarity; (iii) zero-crossing rate (ZCR) estimation-based VTVF detection; and (iv) peak-to-peak interval (PPI) feature based VT/VF discrimination. The proposed method is evaluated using 18,000 episodes of different ECG arrhythmias taken from 6 PhysioNet databases. The method achieves an average sensitivity (Se) of 99.61%, specificity (Sp) of 99.96%, and overall accuracy (OA) of 99.92% in detecting VTVF and non-VTVF episodes by using a ZCR feature. Results show that the method achieves a Se of 100%, Sp of 99.70% and OA of 99.85% for discriminating VT from VF episodes using PPI features extracted from the processed signal. The robustness of the method is tested using different kinds of ECG beats and various types of noises including the baseline wanders, powerline interference and muscle artefacts. Results demonstrate that the proposed method with the ZCR, PPI features can achieve significantly better detection rates as compared with the existing methods.

  13. Reliable Signal Transduction

    Science.gov (United States)

    Wollman, Roy

    Stochasticity inherent to biochemical reactions (intrinsic noise) and variability in cellular states (extrinsic noise) degrade information transmitted through signaling networks. We analyzed the ability of temporal signal modulation - that is dynamics - to reduce noise-induced information loss. In the extracellular signal-regulated kinase (ERK), calcium (Ca(2 +)) , and nuclear factor kappa-B (NF- κB) pathways, response dynamics resulted in significantly greater information transmission capacities compared to nondynamic responses. Theoretical analysis demonstrated that signaling dynamics has a key role in overcoming extrinsic noise. Experimental measurements of information transmission in the ERK network under varying signal-to-noise levels confirmed our predictions and showed that signaling dynamics mitigate, and can potentially eliminate, extrinsic noise-induced information loss. By curbing the information-degrading effects of cell-to-cell variability, dynamic responses substantially increase the accuracy of biochemical signaling networks.

  14. Efficient differentiation of mouse embryonic stem cells into motor neurons.

    Science.gov (United States)

    Wu, Chia-Yen; Whye, Dosh; Mason, Robert W; Wang, Wenlan

    2012-06-09

    Direct differentiation of embryonic stem (ES) cells into functional motor neurons represents a promising resource to study disease mechanisms, to screen new drug compounds, and to develop new therapies for motor neuron diseases such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Many current protocols use a combination of retinoic acid (RA) and sonic hedgehog (Shh) to differentiate mouse embryonic stem (mES) cells into motor neurons. However, the differentiation efficiency of mES cells into motor neurons has only met with moderate success. We have developed a two-step differentiation protocol that significantly improves the differentiation efficiency compared with currently established protocols. The first step is to enhance the neuralization process by adding Noggin and fibroblast growth factors (FGFs). Noggin is a bone morphogenetic protein (BMP) antagonist and is implicated in neural induction according to the default model of neurogenesis and results in the formation of anterior neural patterning. FGF signaling acts synergistically with Noggin in inducing neural tissue formation by promoting a posterior neural identity. In this step, mES cells were primed with Noggin, bFGF, and FGF-8 for two days to promote differentiation towards neural lineages. The second step is to induce motor neuron specification. Noggin/FGFs exposed mES cells were incubated with RA and a Shh agonist, Smoothened agonist (SAG), for another 5 days to facilitate motor neuron generation. To monitor the differentiation of mESs into motor neurons, we used an ES cell line derived from a transgenic mouse expressing eGFP under the control of the motor neuron specific promoter Hb9. Using this robust protocol, we achieved 51 ± 0.8% of differentiation efficiency (n = 3; p motor neuron specific markers, Islet-1 and choline acetyltransferase (ChAT). Our two-step differentiation protocol provides an efficient way to differentiate mES cells into spinal motor neurons.

  15. Achieving Timeliness and High Throughput Metrics in Dissemination Systems

    Directory of Open Access Journals (Sweden)

    MANNE ANUSHA

    2012-09-01

    Full Text Available Existing systems for information dissemination is inadequate and typically results in information gaps. The lack of a clear concise system for information dissemination makes it difficult to determine the most efficient and effective way to pass information especially in the fields of ecommerce and security alerting systems to the appropriate parties. These systems usually require that the desired information be matched between numerous sources and sinks based on established subscriptions. Timeliness and Throughput are performance metrics used for evaluation. And these existing systems fail to achieve a balance between the two. So a much better system termed INFOD (INFOrmation Dissemination was proposed earlier that achieves a balance between performance metrics. We observed that an Integrated Control Loop used by admission control scheme of INFOD employs PL/SQL stored procedures that are huge computation overhead. We propose to replace them with Java stored procedures that can tremendously increase the performance.

  16. Recent Achievement in Gene Cloning and Functional Genomics in Soybean

    Directory of Open Access Journals (Sweden)

    Zhengjun Xia

    2013-01-01

    Full Text Available Soybean is a model plant for photoperiodism as well as for symbiotic nitrogen fixation. However, a rather low efficiency in soybean transformation hampers functional analysis of genes isolated from soybean. In comparison, rapid development and progress in flowering time and photoperiodic response have been achieved in Arabidopsis and rice. As the soybean genomic information has been released since 2008, gene cloning and functional genomic studies have been revived as indicated by successfully characterizing genes involved in maturity and nematode resistance. Here, we review some major achievements in the cloning of some important genes and some specific features at genetic or genomic levels revealed by the analysis of functional genomics of soybean.

  17. High-efficiency Transformerless PV Inverter Circuits

    OpenAIRE

    Chen, Baifeng

    2015-01-01

    With worldwide growing demand for electric energy, there has been a great interest in exploring photovoltaic (PV) sources. For the PV generation system, the power converter is the most essential part for the efficiency and function performance. In recent years, there have been quite a few new transformerless PV inverters topologies, which eliminate the traditional line frequency transformers to achieve lower cost and higher efficiency, and maintain lower leakage current as well. With an ov...

  18. Compact High Efficiency Adsorption Heat Pump

    OpenAIRE

    TeGrotenhuis, Ward E; Humble, Paul H; Sweeney, Josh B

    2012-01-01

    An innovative adsorption cycle heat pump technology is presented that is compact and capable of achieving high energy efficiency for integrated space heating, air conditioning, and water heating. High energy efficiency is accomplished by effectively recuperating heat within the system to minimize energy consumption. This substantially reduces the thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. Furthermore, equipment cost is reduc...

  19. Efficient Generation of Generic Entanglement

    CERN Document Server

    Oliveira, R; Plenio, M B

    2006-01-01

    We find that generic entanglement is physical, in the sense that it can be generated in polynomial time from two-qubit gates picked at random. We prove as the main result that such a process generates the average entanglement of the uniform (Haar) measure in at most $O(N^3)$ steps for $N$ qubits. This is despite an exponentially growing number of such gates being necessary for generating that measure fully on the state space. Numerics furthermore show a variation cut-off allowing one to associate a specific time with the achievement of the uniform measure entanglement distribution. Various extensions of this work are discussed. The results are relevant to entanglement theory and to protocols that assume generic entanglement can be achieved efficiently.

  20. Efficiency in higher education

    Directory of Open Access Journals (Sweden)

    Duguleană, C.

    2011-01-01

    Full Text Available The National Education Law establishes the principles of equity and efficiency in higher education. The concept of efficiency has different meanings according to the types of funding and the time horizons: short or long term management approaches. Understanding the black box of efficiency may offer solutions for an effective activity. The paper presents the parallel presentation of efficiency in a production firm and in a university, for better understanding the specificities of efficiency in higher education.