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Sample records for background phase offset

  1. Estimation of satellite antenna phase center offsets for Galileo

    Science.gov (United States)

    Steigenberger, P.; Fritsche, M.; Dach, R.; Schmid, R.; Montenbruck, O.; Uhlemann, M.; Prange, L.

    2016-08-01

    Satellite antenna phase center offsets for the Galileo In-Orbit Validation (IOV) and Full Operational Capability (FOC) satellites are estimated by two different analysis centers based on tracking data of a global GNSS network. The mean x- and y-offsets could be determined with a precision of a few centimeters. However, daily estimates of the x-offsets of the IOV satellites show pronounced systematic effects with a peak-to-peak amplitude of up to 70 cm that depend on the orbit model and the elevation of the Sun above the orbital plane. For the IOV y-offsets, no dependence on the orbit model exists but the scatter strongly depends on the elevation of the Sun above the orbital plane. In general, these systematic effects are significantly smaller for the FOC satellites. The z-offsets of the two analysis centers agree within the 10-15 cm level, and the time series do not show systematic effects. The application of an averaged Galileo satellite antenna model obtained from the two solutions results in a reduction of orbit day boundary discontinuities by up to one third—even if an independent software package is used.

  2. Estimation of satellite antenna phase center offsets for Galileo

    Science.gov (United States)

    Steigenberger, P.; Fritsche, M.; Dach, R.; Schmid, R.; Montenbruck, O.; Uhlemann, M.; Prange, L.

    2016-05-01

    Satellite antenna phase center offsets for the Galileo In-Orbit Validation (IOV) and Full Operational Capability (FOC) satellites are estimated by two different analysis centers based on tracking data of a global GNSS network. The mean x- and y-offsets could be determined with a precision of a few centimeters. However, daily estimates of the x-offsets of the IOV satellites show pronounced systematic effects with a peak-to-peak amplitude of up to 70 cm that depend on the orbit model and the elevation of the Sun above the orbital plane. For the IOV y-offsets, no dependence on the orbit model exists but the scatter strongly depends on the elevation of the Sun above the orbital plane. In general, these systematic effects are significantly smaller for the FOC satellites. The z-offsets of the two analysis centers agree within the 10-15 cm level, and the time series do not show systematic effects. The application of an averaged Galileo satellite antenna model obtained from the two solutions results in a reduction of orbit day boundary discontinuities by up to one third—even if an independent software package is used.

  3. Study on Optimization of Phase Offset at Adjacent Intersections

    Directory of Open Access Journals (Sweden)

    Yuanli GU

    2010-11-01

    Full Text Available Optimization of the phase offset at adjacent intersections is the key parameter regarding coordinated control of traffic signal for adjacent intersections, which decides the effect of the coordinated control for adjacent intersections. According to characters of saturated traffic flow of Chinese urban road, this thesis establishes a model for optimization of phase offset for adjacent interactions and finds a solution from such model by adopting genetic algorithm. The model is verified by actual traffic flow datum of two adjacent signal intersections on Changan Avenue. Then a comparison is made between the optimization result of such model and that of the existing mathematical method and SYNCHRO model, which indicates that the model established by this thesis can reduce the delay suffered by vehicles at the intersections and increase the traffic efficiency of the intersections.

  4. Performance Evaluation Of An Ofdm System Under The Influence Of Phase Noise And Carrier Frequency Offset(

    Directory of Open Access Journals (Sweden)

    Gurpreet Kaur

    2012-06-01

    Full Text Available The two most important parameters to be considered while designing an OFDM based communication system are phase noise and carrier frequency offset (CFO. It has been observed that the OFDM systems are very sensitive to phase noise and CFO, and an accurate prediction of the tolerable values of theseparameters can help the system to relax the specifications. This paper analyses the performance of OFDM systems in the presence of phase noise and carrier frequency offset. Results clearly show the SINR penalty in the OFDM system due to phase noise and CFO.

  5. Blind Estimation of the Phase and Carrier Frequency Offsets for LDPC-Coded Systems

    Directory of Open Access Journals (Sweden)

    Houcke Sebastien

    2010-01-01

    Full Text Available Abstract We consider in this paper the problem of phase offset and Carrier Frequency Offset (CFO estimation for Low-Density Parity-Check (LDPC coded systems. We propose new blind estimation techniques based on the calculation and minimization of functions of the Log-Likelihood Ratios (LLR of the syndrome elements obtained according to the parity check matrix of the error-correcting code. In the first part of this paper, we consider phase offset estimation for a Binary Phase Shift Keying (BPSK modulation and propose a novel estimation technique. Simulation results show that the proposed method is very effective and outperforms many existing algorithms. Then, we modify the estimation criterion so that it can work for higher-order modulations. One interesting feature of the proposed algorithm when applied to high-order modulations is that the phase offset of the channel can be blindly estimated without any ambiguity. In the second part of the paper, we consider the problem of CFO estimation and propose estimation techniques that are based on the same concept as the ones presented for the phase offset estimation. The Mean Squared Error (MSE and Bit Error Rate (BER curves show the efficiency of the proposed estimation techniques.

  6. Modulation of auroral electrojet currents using dual HF beams with ELF phase offset

    Science.gov (United States)

    Golkowski, M.; Cohen, M.; Moore, R. C.

    2012-12-01

    The modulation of naturally occuring ionospheric currents with high power radio waves in the high frequency (HF, 3-10 MHz) band is a well known technique for generation of extremely low frequency (ELF, 3-3000 Hz) and very low frequency (VLF, 3-30 kHz) waves. We use the heating facility of the High Frequency Active Auroral Research Program (HAARP) to investigate the effect of using dual HF beams with an ELF/VLF phase offset between the modulation waveforms. Experiments with offset HF beams confirm the model of independent ELF/VLF sources. Experiments with co-located HF beams exhibit interaction between the first and second harmonics of the modulated tones when square and sine wave modulation waveforms are employed. Using ELF/VLF phase offsets for co-loacted beams is also shown to be a potential diagnostic for the D-region ionospheric profile.

  7. The effects and inhibition of frequency offset on differential phase-shift keying detection

    Science.gov (United States)

    Guo, Hao; Zhou, Jing; Su, Shaojing; Pan, Zhongming

    2015-10-01

    Differential phase-shift keying (DPSK) has been widely implemented and developed in high-speed optical communication systems. The low error rate detection at high access rate is one of the considerable issues in practical engineering application. Balanced detection based on fiber Mach-Zehnder delay interferometer (MZDI) is the typical optical DPSK signal detecting method. It requires that the free spectrum range (FSR) of the MZDI equals the reciprocal of symbol period of the DPSK signal. For the reasons of ambient temperature variation and nonlinear phase noise, a dynamic frequency offset always exists between the FSR and the reciprocal of symbol period. That may introduce some optical signal-to-noise ratio (OSNR) costs and fault detections. Therefore, it is significant to inhibit the frequency offset on DPSK detection. In this paper, firstly, we discuss the effects of frequency offset on DPSK detection, and realize the conclusion that frequency offset is virtually equivalent to an additional phase difference between adjacent symbols. Secondly, through simulation, we analyze the feasibility of DPSK detection in the presence of a definite range of frequency offset, and present the quantitative computation of effective coverage, duty cycle, and optimal sampling time of symbol interference. Some issues which should be considered in practical implementation are also discussed. Finally, according to the relationship among phase difference, temperature and voltage, we propose a phase difference compensation scheme which can automatically adjust the voltage for optimal detections, and dynamically track the changing of ambient temperature and nonlinear phase noise. Furthermore, we ascertain the performance of the voltage requested for implementing the scheme. The scheme can be also developed to quadrature phase-shift keying (QPSK) and differential QPSK (DQPSK) modulation situations.

  8. A SHA-less 14-bit, 100-MS/s pipelined ADC with comparator offset cancellation in background

    Science.gov (United States)

    Xiaofei, Wang; Hong, Zhang; Jie, Zhang; Xin, Du; Yue, Hao

    2016-03-01

    A 14-bit 100-MS/s pipelined analog-to-digital converter (ADC) without dedicated front-end sample-and-hold amplifier (SHA) is presented. In addition to elaborate matching of the sampling network in the first stage, a background offset cancellation circuit is proposed in this paper to suppress the offset of the comparators in the first-stage sub-ADC, which ensures the overall offset does not exceed the correction range of the built-in redundant structure. Fabricated in a 0.18-μm CMOS technology, the presented ADC occupies a chip area of 12 mm2, and consumes 237 mW from a 1.8-V power supply. Measurement results with a 30.1-MHz input sine wave under a sampling rate of 100 MS/s show that the ADC achieves a 71-dB signal-to-noise and distortion ratio (SNDR), an 85.4-dB spurious-free dynamic range (SFDR), a maximum differential nonlinearity (DNL) of 0.22 LSB and a maximum integral nonlinearity (INL) of 1.4 LSB. Project supported by the National Natural Science Foundation of China (No. 61474092).

  9. Offset phase locking of noisy diode lasers aided by frequency division

    Science.gov (United States)

    Ivanov, E. N.; Esnault, F.-X.; Donley, E. A.

    2011-08-01

    For heterodyne phase locking, frequency division of the beat note between two oscillators can improve the reliability of the phase lock and the quality of the phase synchronization. Frequency division can also reduce the size, weight, power, and cost of the instrument by excluding the microwave synthesizer from the control loop when the heterodyne offset frequency is large (5 to 10 GHz). We have experimentally tested the use of a frequency divider in an optical phase-lock loop and compared the achieved level of residual phase fluctuations between two diode lasers with that achieved without the use of a frequency divider. The two methods achieve comparable phase stability provided that sufficient loop gain is maintained after frequency division to preserve the required bandwidth. We have also numerically analyzed the noise properties and internal dynamics of phase-locked loops subjected to a high level of phase fluctuations, and our modeling confirms the expected benefits of having an in-loop frequency divider.

  10. Improving the Estimation of Uncalibrated Fractional Phase Offsets for PPP Ambiguity Resolution

    OpenAIRE

    Xingxing Li; Zhang, X

    2012-01-01

    Integer ambiguity resolution in Precise Point Positioning (PPP) can shorten convergence time and improve accuracy significantly. Uncalibrated Fractional Offsets (UFOs) originating in the satellites destroy the integer nature of carrier phase ambiguities observed at a single station. Several methods have been developed to estimate UFO information from a reference network for PPP ambiguity resolution. In this paper, we present a new approach for estimating Zero-Differenced (ZD) UFOs via float Z...

  11. Characteristics and performance of offset phase locked single frequency heterodyned laser systems

    Science.gov (United States)

    Tulchinsky, David A.; Hastings, Alexander S.; Williams, Keith J.

    2016-05-01

    We demonstrate and characterize the performance of two heterodyned optical phase locked loop (PLL) laser systems for use in characterizing photodetector RF frequency response and nonlinearities. Descriptions of PLL circuit parameters for Nd:YAG non-planar ring oscillator lasers at 1064 nm and 1319 nm, and Er ion fiber lasers from 1530 nm to 1565 nm are presented. Both laser systems have piezoelectric transducer wavelength control over the PLL voltage controlled oscillator circuit. Offset frequency phase locking from 1.5 kHz to 51+ GHz is demonstrated. Frequency stability at 10 MHz is measured to be ±50 μHz, limited by the stability of the Rb stabilized crystal oscillator. Phase noise of the phase-locked 1319 nm laser system is discussed where we find that the phase noise is dominated by the input source noise at frequency offsets below 100 Hz and by the laser's RIN noise at frequency offsets > 100 Hz. Comparing nonlinearity data from an InGaAs p-i-n photodiode using both 1319 nm and 1550 nm PLL nonlinearity measurement systems, we find two new separate photodetector nonlinearity mechanisms. Measurements of the harmonic components of a 11 MHz sinusoidal heterodyned optical beat note signal are found to be at or below 1 nW/mW for the second harmonic (at 22 MHz) and at or below 0.25 nW/mW for the 3rd harmonic (at 33 MHz), confirming the nearly pure sinusoidal nature of the optically generated microwave beat note.

  12. Laser Trimming for Adjustment of Grating Offset in Phase-Shifted Fiber Grating Coupler for All-Optical Switching Application

    Institute of Scientific and Technical Information of China (English)

    Hirohisa; Yokota; Yutaka; Sasaki

    2003-01-01

    We theoretically investigated laser trimming to adjust grating offset in phase-shifted fiber grating coupler (FGC) for all-optical switching application. It was clarified that the trimming made the extinction ratio higher in all-optical FGC switch.

  13. Improved dichotomous search frequency offset estimator for burst-mode continuous phase modulation

    Science.gov (United States)

    Zhai, Wen-Chao; Li, Zan; Si, Jiang-Bo; Bai, Jun

    2015-11-01

    A data-aided technique for carrier frequency offset estimation with continuous phase modulation (CPM) in burst-mode transmission is presented. The proposed technique first exploits a special pilot sequence, or training sequence, to form a sinusoidal waveform. Then, an improved dichotomous search frequency offset estimator is introduced to determine the frequency offset using the sinusoid. Theoretical analysis and simulation results indicate that our estimator is noteworthy in the following aspects. First, the estimator can operate independently of timing recovery. Second, it has relatively low outlier, i.e., the minimum signal-to-noise ratio (SNR) required to guarantee estimation accuracy. Finally, the most important property is that our estimator is complexity-reduced compared to the existing dichotomous search methods: it eliminates the need for fast Fourier transform (FFT) and modulation removal, and exhibits faster convergence rate without accuracy degradation. Project supported by the National Natural Science Foundation of China (Grant No. 61301179), the Doctorial Programs Foundation of the Ministry of Education, China (Grant No. 20110203110011), and the Programme of Introducing Talents of Discipline to Universities, China (Grant No. B08038).

  14. Feed-forward carrier phase recovery for offset-QAM Nyquist WDM transmission.

    Science.gov (United States)

    Tang, Haoyuan; Xiang, Meng; Fu, Songnian; Tang, Ming; Shum, Perry; Liu, Deming

    2015-03-01

    Due to the half symbol delay between in-phase and quadrature components for offset quadrature amplitude modulation (OQAM) signal, phase noise cannot only lead to constellation rotation but also introduce additional crosstalk. Therefore, OQAM signal has very poor tolerance to the laser linewidth. Here, we carry out a semi-analytical investigation of phase noise induced crosstalk during OQAM Nyquist WDM transmission, and find that the carrier phase recovery (CPR) has to be implemented prior to the inter-symbol-interference (ISI) equalization. Then, after a function separation of polarization de-multiplexing and ISI equalization, we propose a new DSP flow with a linewidth-tolerant blind feed-forward CPR scheme for OQAM signal. Its effectiveness is verified under the scenario of 5-channel 28-Gbaud polarization multiplexing (PM) OQAM Nyquist WDM systems. A tolerance of linewidth and symbol duration products of 6.5×10(-4) and 1.1×10(-4) is secured for 4-OQAM and 16-OQAM, respectively, given 1-dB required-OSNR penalty at BER = 10(-3).

  15. Phase-ramp reduction in interseismic interferograms from pixel-offsets

    KAUST Repository

    Wang, Teng

    2014-05-01

    Interferometric synthetic aperture radar (InSAR) is increasingly used to measure interseismic deformation. Inaccurate satellite-orbit information, expressed as phase ramps across interseismic interferograms, is believed to be one of the main sources of error in such measurements. However, many interferograms exhibit higher phase gradients than expected from the reported orbital accuracy, suggesting that there are other error sources. Here, we show that interferogram phase ramps are in part caused by uncorrected satellite timing-parameter errors. We propose a two-step approach to reduce the phase ramps using pixel-offsets estimated between SAR amplitude images. The first step involves using a digital elevation model (DEM) to estimate absolute timing-parameter errors for the reference image of the SAR dataset and the second step updates the timing parameters of the master image for each interferogram. We demonstrate a clear ramp reduction on interseismic interferograms covering the North Anatolian Fault in eastern Turkey. The resulting interferograms show clear signs of interseismic deformation even before stacking. © 2014 IEEE.

  16. Monitoring Mining Subsidence Using A Combination of Phase-Stacking and Offset-Tracking Methods

    Directory of Open Access Journals (Sweden)

    Hongdong Fan

    2015-07-01

    Full Text Available An approach to study the mechanism of mining-induced subsidence, using a combination of phase-stacking and sub-pixel offset-tracking methods, is reported. In this method, land subsidence with a small deformation gradient was calculated using time-series differential interferometric synthetic aperture radar (D-InSAR data, whereas areas with greater subsidence were calculated by a sub-pixel offset-tracking method. With this approach, time-series data for mining subsidence were derived in Yulin area using 11 TerraSAR-X (TSX scenes from 13 December 2012 to 2 April 2013. The maximum mining subsidence and velocity values were 4.478 m and 40 mm/day, respectively, which were beyond the monitoring capabilities of D-InSAR and advanced InSAR. The results were compared with the GPS field survey data, and the root mean square errors (RMSE of the results in the strike and dip directions were 0.16 m and 0.11 m, respectively. Four important results were obtained from the time-series subsidence in this mining area: (1 the mining-induced subsidence entered the residual deformation stage within about 44 days; (2 the advance angle of influence changed from 75.6° to 80.7°; (3 the prediction parameters of mining subsidence; (4 three-dimensional deformation. This method could be used to predict the occurrence of mining accidents and to help in the restoration of the ecological environment after mining activities have ended.

  17. A high-resolution multi-phase delay-locked loop with offset locking technique

    Science.gov (United States)

    Chuang, Chi-Nan; Wu, Chun-Yen; Lin, Tsui-Wei

    2016-10-01

    In this work, we propose a new type of high-resolution delay-locked loop (DLL) which achieves the performance of high-resolution output by offset locking techniques without restrictions of intrinsic delay in the delay cell. Compared to traditional multi-phase clock generator, this architecture has the features of small size, low jitters, low-power consumption and high resolution. This DLL has been fabricated in 0.35 μm complementary metal-oxide-semiconductor (CMOS) process. The measured root-mean-square and peak-to-peak jitters are 2.89 ps and 31.1 ps at 250 MHz, respectively. The power dissipation is 68 mW for a supply voltage of 3.3 V. The maximum resolution of this work is 144 p and the intrinsic delay of 0.35 μm CMOS process is 220 ps. Comparing with intrinsic delay, the improvement of maximum resolution is 34.5%.

  18. Displaced phase-amplitude variables for waves on finite background

    NARCIS (Netherlands)

    Groesen, van E.; Andonowati,; Karjanto, N.

    2006-01-01

    Wave amplification in nonlinear dispersive wave equations may be caused by nonlinear focussing of waves from a certain background. In the model of nonlinear Schrödinger equation we will introduce a transformation to displaced phase-amplitude variables with respect to a background of monochromatic wa

  19. Removing Background Noise with Phased Array Signal Processing

    Science.gov (United States)

    Podboy, Gary; Stephens, David

    2015-01-01

    Preliminary results are presented from a test conducted to determine how well microphone phased array processing software could pull an acoustic signal out of background noise. The array consisted of 24 microphones in an aerodynamic fairing designed to be mounted in-flow. The processing was conducted using Functional Beam forming software developed by Optinav combined with cross spectral matrix subtraction. The test was conducted in the free-jet of the Nozzle Acoustic Test Rig at NASA GRC. The background noise was produced by the interaction of the free-jet flow with the solid surfaces in the flow. The acoustic signals were produced by acoustic drivers. The results show that the phased array processing was able to pull the acoustic signal out of the background noise provided the signal was no more than 20 dB below the background noise level measured using a conventional single microphone equipped with an aerodynamic forebody.

  20. Phase offsets between core and conal components of radio pulsars and their emission altitudes

    CERN Document Server

    Kapoor, R C

    2002-01-01

    We present a new method for investigating emission altitudes of radio pulsar core and conal components by attributing them different altitudes and by providing a framework to understand the resulting longitude offsets between them which are frequently observed. By investigating the contributions to these offsets due to aberration and the magnetic field line sweepback, we show that they are always dominated by aberration for all emission altitudes and inclination angles. This directly allows the conclusion that the core emission does not necessarily come from the surface. Our results and the observational trends imply that for a large number of pulsars the emission altitudes of core and conal components are close when compared to the light cylinder radius but not necessarily relative to the stellar radius. The core/cone altitude differences that we find are typically larger than the individual altitudes ascribed to them so far. Widely different core/cone altitudes for some pulsars are also supported by data an...

  1. Background velocity inversion by phase along reflection wave paths

    KAUST Repository

    Yu, Han

    2014-08-05

    A background velocity model containing the correct lowwavenumber information is desired for both the quality of the migration image and the success of waveform inversion. We propose to invert for the low-wavenumber part of the velocity model by minimizing the phase difference between predicted and observed reflections. The velocity update is exclusively along the reflection wavepaths and, unlike conventional FWI, not along the reflection ellipses. This allows for reconstructing the smoothly varying parts of the background velocity model. Tests with synthetic data show both the benefits and limitations of this method.

  2. Five Approaches to Deal With Problem of DC Offset in Phase-Locked Loop Algorithms: Design Considerations and Performance Evaluations

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Gharehpetian, Gevork B.

    2016-01-01

    The presence of the dc component in the phaselocked loop (PLL) input results in fundamental frequency oscillations in the phase and frequency estimated by the PLL. The removal of these oscillations is a challenging task because of their low frequency. The aim of this paper is to provide a detailed...... analysis of several approaches that little work has been conducted on their application for addressing the problem of dc offset in the PLL algorithms. These approaches include using the dq-frame delayed signal cancellation (DSC) operator and the notch filter as the PLL in-loop filtering stages, and using...

  3. Background rejection of n+ surface events in GERDA Phase II

    Science.gov (United States)

    Lehnert, Björn

    2016-05-01

    The GERDA experiment searches for neutrinoless double beta (0vββ) decay in 76Ge using an array of high purity germanium (HPGe) detectors immersed in liquid argon (LAr). Phase II of the experiment uses 30 new broad energy germanium (BEGe) detectors with superior pulse shape discrimination capabilities compared to the previously used semi-coaxial detector design. By far the largest background component for BEGe detectors in GERDA are n+-surface events from 42K β decays which are intrinsic in LAr. The β particles with up to 3.5 MeV can traverse the 0.5 to 0.9 mm thick electrode and deposit energy within the region of interest for the 0vββ decay. However, those events have particular pulse shape features allowing for a strong discrimination. The understanding and simulation of this background, showing a reduction by up to a factor 145 with pulse shape discrimination alone, is presented in this work.

  4. Non-Pilot-Aided Sequential Monte Carlo Method to Joint Signal, Phase Noise, and Frequency Offset Estimation in Multicarrier Systems

    Directory of Open Access Journals (Sweden)

    Christelle Garnier

    2008-05-01

    Full Text Available We address the problem of phase noise (PHN and carrier frequency offset (CFO mitigation in multicarrier receivers. In multicarrier systems, phase distortions cause two effects: the common phase error (CPE and the intercarrier interference (ICI which severely degrade the accuracy of the symbol detection stage. Here, we propose a non-pilot-aided scheme to jointly estimate PHN, CFO, and multicarrier signal in time domain. Unlike existing methods, non-pilot-based estimation is performed without any decision-directed scheme. Our approach to the problem is based on Bayesian estimation using sequential Monte Carlo filtering commonly referred to as particle filtering. The particle filter is efficiently implemented by combining the principles of the Rao-Blackwellization technique and an approximate optimal importance function for phase distortion sampling. Moreover, in order to fully benefit from time-domain processing, we propose a multicarrier signal model which includes the redundancy information induced by the cyclic prefix, thus leading to a significant performance improvement. Simulation results are provided in terms of bit error rate (BER and mean square error (MSE to illustrate the efficiency and the robustness of the proposed algorithm.

  5. Direct frequency comb synthesis with arbitrary offset and shot-noise-limited phase noise

    Science.gov (United States)

    Koke, Sebastian; Grebing, Christian; Frei, Harald; Anderson, Alexandria; Assion, Andreas; Steinmeyer, Günter

    2010-07-01

    Carrier-envelope phase stabilization has opened an avenue towards achieving frequency metrology with unprecedented precision and optical pulse generation on the previously inaccessible attosecond timescale. Recently, sub-100-as pulse generation has been demonstrated, approaching the timescale of the fastest transients in atomic physics. However, further progress in attophysics appears to be limited by the performance of the traditional feedback approach used for carrier-envelope phase stabilization. Here, we demonstrate a conceptually different self-referenced feed-forward approach to phase stabilization. This approach requires no complicated locking electronics, does not compromise laser performance, and is demonstrated with 12-as residual timing jitter, which is below the atomic unit of time. This surpasses the precision of previous methods by more than a factor of five and has potential for resolving even the fastest transients in atomic or molecular physics. Such shot-noise-limited comb synthesis may also simplify progress in current research in frequency metrology.

  6. Background suppression in Gerda Phase II and its study in the LArGe low background set-up

    International Nuclear Information System (INIS)

    In Phase II of the Gerda experiment additional ∝20 kg of BEGe-type germanium detectors, enriched in 76Ge, will be deployed in liquid argon (LAr) to further increase the sensitivity for the half-life of neutrinoless double beta (0νββ) decay of 76Ge to > 2 . 1026 yr. To reduce background by a factor of 10 to the required level of -3 cts/(keV.kg.yr), it is necessary to employ active background-suppression techniques, including anti-Compton veto using scintillation light detection from LAr and pulse shape discrimination exploiting the characteristic electrical field distribution inside BEGe detectors. The latter technique can identify single-site events (typical for 0νββ) and efficiently reject multi-site events (mainly from γ-rays), as well as different types of background events from detector surfaces. The combined power of these techniques was studied for 42K and other background sources at the low background facility LArGe. Together with extensive simulations, the information from tracking of the Phase II detector material exposure to cosmic rays and based on the background contributions observed in Phase I, the expected background level in Phase II in the region of interest at 2039 keV, the Qββ energy of 76Ge, is estimated. The preliminary analysis shows that contributions from all expected background components after all cuts are in line with the goal of Gerda Phase II.

  7. Analysis of an automated background correction method for cardiovascular MR phase contrast imaging in children and young adults

    Energy Technology Data Exchange (ETDEWEB)

    Rigsby, Cynthia K.; Hilpipre, Nicholas; Boylan, Emma E.; Popescu, Andrada R.; Deng, Jie [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); McNeal, Gary R. [Siemens Medical Solutions USA Inc., Customer Solutions Group, Cardiovascular MR R and D, Chicago, IL (United States); Zhang, Gang [Ann and Robert H. Lurie Children' s Hospital of Chicago Research Center, Biostatistics Research Core, Chicago, IL (United States); Choi, Grace [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Greiser, Andreas [Siemens AG Healthcare Sector, Erlangen (Germany)

    2014-03-15

    Phase contrast magnetic resonance imaging (MRI) is a powerful tool for evaluating vessel blood flow. Inherent errors in acquisition, such as phase offset, eddy currents and gradient field effects, can cause significant inaccuracies in flow parameters. These errors can be rectified with the use of background correction software. To evaluate the performance of an automated phase contrast MRI background phase correction method in children and young adults undergoing cardiac MR imaging. We conducted a retrospective review of patients undergoing routine clinical cardiac MRI including phase contrast MRI for flow quantification in the aorta (Ao) and main pulmonary artery (MPA). When phase contrast MRI of the right and left pulmonary arteries was also performed, these data were included. We excluded patients with known shunts and metallic implants causing visible MRI artifact and those with more than mild to moderate aortic or pulmonary stenosis. Phase contrast MRI of the Ao, mid MPA, proximal right pulmonary artery (RPA) and left pulmonary artery (LPA) using 2-D gradient echo Fast Low Angle SHot (FLASH) imaging was acquired during normal respiration with retrospective cardiac gating. Standard phase image reconstruction and the automatic spatially dependent background-phase-corrected reconstruction were performed on each phase contrast MRI dataset. Non-background-corrected and background-phase-corrected net flow, forward flow, regurgitant volume, regurgitant fraction, and vessel cardiac output were recorded for each vessel. We compared standard non-background-corrected and background-phase-corrected mean flow values for the Ao and MPA. The ratio of pulmonary to systemic blood flow (Qp:Qs) was calculated for the standard non-background and background-phase-corrected data and these values were compared to each other and for proximity to 1. In a subset of patients who also underwent phase contrast MRI of the MPA, RPA, and LPA a comparison was made between standard non-background

  8. The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores

    CERN Document Server

    Behroozi, Peter S; Wu, Hao-Yi

    2011-01-01

    We present a new algorithm for identifying dark matter halos, substructure, and tidal features. The approach is based on adaptive hierarchical refinement of friends-of-friends groups in six phase-space dimensions and one time dimension, which allows for robust (grid-independent, shape-independent, and noise-resilient) tracking of substructure; as such, it is named Rockstar (Robust Overdensity Calculation using K-Space Topologically Adaptive Refinement). Our method is massively parallel (up to 10^5 CPUs) and runs on the largest current simulations (>10^10 particles) with high efficiency (10 CPU hours and 60 gigabytes of memory required per billion particles analyzed). A previous paper (Knebe et al 2011) has shown Rockstar to have class-leading recovery of halo properties; we expand on these comparisons with more tests and higher-resolution simulations. We show a significant improvement in substructure recovery as compared to several other halo finders and discuss the theoretical and practical limits of simulat...

  9. Background suppression in Gerda Phase II and its study in the LArGe low background set-up

    Energy Technology Data Exchange (ETDEWEB)

    Budjas, Dusan [Physik-Department E15, Technische Universitaet Muenchen (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    In Phase II of the Gerda experiment additional ∝20 kg of BEGe-type germanium detectors, enriched in {sup 76}Ge, will be deployed in liquid argon (LAr) to further increase the sensitivity for the half-life of neutrinoless double beta (0νββ) decay of {sup 76}Ge to > 2 . 10{sup 26} yr. To reduce background by a factor of 10 to the required level of < 10{sup -3} cts/(keV.kg.yr), it is necessary to employ active background-suppression techniques, including anti-Compton veto using scintillation light detection from LAr and pulse shape discrimination exploiting the characteristic electrical field distribution inside BEGe detectors. The latter technique can identify single-site events (typical for 0νββ) and efficiently reject multi-site events (mainly from γ-rays), as well as different types of background events from detector surfaces. The combined power of these techniques was studied for {sup 42}K and other background sources at the low background facility LArGe. Together with extensive simulations, the information from tracking of the Phase II detector material exposure to cosmic rays and based on the background contributions observed in Phase I, the expected background level in Phase II in the region of interest at 2039 keV, the Q{sub ββ} energy of {sup 76}Ge, is estimated. The preliminary analysis shows that contributions from all expected background components after all cuts are in line with the goal of Gerda Phase II.

  10. Modulation of auroral electrojet currents using dual modulated HF beams with ELF phase offset, a potential D-region ionospheric diagnostic

    Science.gov (United States)

    GołKowski, M.; Cohen, M. B.; Moore, R. C.

    2013-05-01

    Experiments at the ionospheric heating facility of the High Frequency Active Auroral Research Program (HAARP) are performed employing dual HF beams amplitude modulated at ELF/VLF with a phase offset between the two modulation waveforms. The amplitude of the observed ELF/VLF waves is strongly dependent on the imposed ELF/VLF phase offset, the modulation waveform, and the orientation of the HF beams. Data from two ground stations are interpreted using simulations of modulated heating power envelopes as well as a comprehensive model of ionospheric ELF/VLF generation. It is found that two colocated vertical beams HF beams excite a single ionospheric ELF/VLF source, but independent ELF/VLF sources can be induced in the ionospheric region above the heater if the HF beams are offset from zenith to intersect at their 3 dB points. Furthermore, the use of two vertical HF beams with ELF phase offset is found to be a potential diagnostic method for the ionospheric D region.

  11. Aharonov-Bohm phase for an electromagnetic wave background

    Energy Technology Data Exchange (ETDEWEB)

    Bright, Max [California State University Fresno, Department of Physics, Fresno, CA (United States); Singleton, Douglas [California State University Fresno, Department of Physics, Fresno, CA (United States); UNESP-Univ. Estadual Paulista, ICTP South American Institute for Fundamental Research, Sao Paulo, SP (Brazil); Yoshida, Atsushi [University of Virginia, Department of Physics, Charlottesville, VA (United States); Hue University College of Education, Hue (Viet Nam)

    2015-09-15

    The canonical Aharonov-Bohm effect is usually studied with time-independent potentials. In this work, we investigate the Aharonov-Bohm phase acquired by a charged particle moving in time-dependent potentials. In particular, we focus on the case of a charged particle moving in the time-varying field of a plane electromagnetic wave. We work out the Aharonov-Bohm phase using both the potential (i.e. circular integral A{sub μ} dx{sup μ}) and the field (i.e. (1)/(2) ∫ F{sub μν}dσ{sup μν}) forms of the Aharonov-Bohm phase. We give conditions in terms of the parameters of the system (frequency of the electromagnetic wave, the size of the space-time loop, amplitude of the electromagnetic wave) under which the time-varying Aharonov-Bohm effect could be observed. (orig.)

  12. The Effect of Doppler Frequency Shift, Frequency Offset of the Local Oscillators, and Phase Noise on the Performance of Coherent OFDM Receivers

    Science.gov (United States)

    Xiong, Fuqin; Andro, Monty

    2001-01-01

    This paper first shows that the Doppler frequency shift affects the frequencies of the RF carrier, subcarriers, envelope, and symbol timing by the same percentage in an Orthogonal Frequency Division Multiplexing (OFDM) signal or any other modulated signals. Then the SNR degradation of an OFDM system due to Doppler frequency shift, frequency offset of the local oscillators and phase noise is analyzed. Expressions are given and values for 4-, 16-, 64-, and 256-QAM OFDM systems are calculated and plotted. The calculations show that the Doppler shift of the D3 project is about 305 kHz, and the degradation due to it is about 0.01 to 0.04 dB, which is negligible. The degradation due to frequency offset and phase noise of local oscillators will be the main source of degradation. To keep the SNR degradation under 0.1 dB, the relative frequency offset due to local oscillators must be below 0.01 for the 16 QAM-OFDM. This translates to an offset of 1.55 MHz (0.01 x 155 MHz) or a stability of 77.5 ppm (0.01 x 155 MHz/20 GHz) for the DI project. To keep the SNR degradation under 0.1 dB, the relative linewidth (0) due to phase noise of the local oscillators must be below 0.0004 for the 16 QAM-OFDM. This translates to a linewidth of 0.062 MHz (0.0004 x 155 MHz) of the 20 GHz RIF carrier. For a degradation of 1 dB, beta = 0.04, and the linewidth can be relaxed to 6.2 MHz.

  13. Phase shift extraction and wavefront retrieval from interferograms with background and contrast fluctuations

    International Nuclear Information System (INIS)

    The fluctuations of background and contrast cause measurement errors in the phase-shifting technique. To extract the phase shifts from interferograms with background and contrast fluctuations, an iterative algorithm is represented. The phase shifts and wavefront phase are calculated in two individual steps with the least-squares method. The fluctuation factors are determined when the phase shifts are calculated, and the fluctuations are compensated when the wavefront phase is calculated. The advantage of the algorithm lies in its ability to extract phase shifts from interferograms with background and contrast fluctuations converging stably and rapidly. Simulations and experiments verify the effectiveness and reliability of the proposed algorithm. The convergence accuracy and speed are demonstrated by the simulation results. The experiment results show its ability for suppressing phase retrieval errors. (paper)

  14. Analog CMOS peak detect and hold circuits. Part 2. The two-phase offset-free and derandomizing configuration

    International Nuclear Information System (INIS)

    An analog CMOS peak detect and hold (PDH) circuit, which combines high speed and accuracy, rail-to-rail sensing and driving, low power, and buffering is presented. It is based on a configuration that cancels the major error sources of the classical CMOS PDH, including offset and common mode gain, by re-using the same amplifier for tracking, peak sensing, and output buffering. By virtue of its high absolute accuracy, two or more PDHs can be used in parallel to serve as a data-driven analog memory for derandomization. The first experimental results on the new peak detector and derandomizer (PDD) circuit, fabricated in 0.35 μm CMOS technology, include a 0.2% absolute accuracy for pulses with 500 ns peaking time, 2.7 V linear input range, 3.3 mW power dissipation, 250 mV/s droop rate, and negligible dead time. The use of such a high performance analog PDD can greatly relax the requirements on the digitization in multi-channel systems

  15. Analog CMOS peak detect and hold circuits. Part 2. The two-phase offset-free and derandomizing configuration

    Science.gov (United States)

    De Geronimo, Gianluigi; O'Connor, Paul; Kandasamy, Anand

    2002-05-01

    An analog CMOS peak detect and hold (PDH) circuit, which combines high speed and accuracy, rail-to-rail sensing and driving, low power, and buffering is presented. It is based on a configuration that cancels the major error sources of the classical CMOS PDH, including offset and common mode gain, by re-using the same amplifier for tracking, peak sensing, and output buffering. By virtue of its high absolute accuracy, two or more PDHs can be used in parallel to serve as a data-driven analog memory for derandomization. The first experimental results on the new peak detector and derandomizer (PDD) circuit, fabricated in 0.35 μm CMOS technology, include a 0.2% absolute accuracy for pulses with 500 ns peaking time, 2.7 V linear input range, 3.3 mW power dissipation, 250 mV/s droop rate, and negligible dead time. The use of such a high performance analog PDD can greatly relax the requirements on the digitization in multi-channel systems.

  16. Analog CMOS peak detect and hold circuits. Part 2. The two-phase offset-free and derandomizing configuration

    CERN Document Server

    De Geronimo, G; Kandasamy, A

    2002-01-01

    An analog CMOS peak detect and hold (PDH) circuit, which combines high speed and accuracy, rail-to-rail sensing and driving, low power, and buffering is presented. It is based on a configuration that cancels the major error sources of the classical CMOS PDH, including offset and common mode gain, by re-using the same amplifier for tracking, peak sensing, and output buffering. By virtue of its high absolute accuracy, two or more PDHs can be used in parallel to serve as a data-driven analog memory for derandomization. The first experimental results on the new peak detector and derandomizer (PDD) circuit, fabricated in 0.35 mu m CMOS technology, include a 0.2% absolute accuracy for pulses with 500 ns peaking time, 2.7 V linear input range, 3.3 mW power dissipation, 250 mV/s droop rate, and negligible dead time. The use of such a high performance analog PDD can greatly relax the requirements on the digitization in multi-channel systems.

  17. Phase analysis of the cosmic microwave background from an incomplete sky coverage

    CERN Document Server

    Chiang, Lung-Yih

    2007-01-01

    Phases of the spherical harmonic analysis of full-sky cosmic microwave background (CMB) temperature data contain useful information complementary to the ubiquitous angular power spectrum. In this letter we present a new method of phase analysis on incomplete sky maps. They are the Fourier phases of equal-latitude pixel rings of the map, which are related to the mean angle of the trigonometric moments from the full-sky phases. They have an advantage for probing regions of interest without tapping polluted Galactic plane area, and can localize non-Gaussian features and departure from statistical isotropy in the CMB.

  18. Phase retrieval with background compensation in 4f configuration: advanced augmented Lagrangian technique for amplitude object

    CERN Document Server

    Migukin, Artem; Katkovnik, Vladimir

    2012-01-01

    Generally, wave field reconstructions obtained by phase-retrieval algorithms are noisy, blurred and corrupted by various artifacts such as irregular waves, spots, etc. These disturbances, arising due to many factors such as non-idealities of optical system (misalignment, focusing errors), dust on optical elements, reflections, vibration, are hard to be localized and specified. It is assumed that there is a generalized pupil function at the object plane which describes aberrations in the coherent imaging system manifested at the sensor plane. Here we propose a novel two steps phase-retrieval algorithm to compensate these distortions. We first estimate the cumulative disturbance, called background, using special calibration experiments. Then, we use this background for reconstruction of the object amplitude and phase. The second part of the algorithm is based on the maximum likelihood approach and, in this way, targeted on the optimal amplitude and phase reconstruction from noisy data. Numerical experiments dem...

  19. Temporal Offsets between Maximum CME Speed Index and Solar, Geomagnetic, and Interplanetary Indicators during Solar Cycle 23 and the Ascending Phase of Cycle 24

    CERN Document Server

    Özgüç, A; Georgieva, K; Kirov, B

    2016-01-01

    On the basis of morphological analysis of yearly values of the maximum CME (coronal mass ejection) speed index, the sunspot number and total sunspot area, sunspot magnetic field, and solar flare index, the solar wind speed and interplanetary magnetic field strength, and the geomagnetic Ap and Dst indices, we point out the particularities of solar and geomagnetic activity during the last cycle 23, the long minimum which followed it and the ascending branch of cycle 24. We also analyze temporal offset between the maximum CME speed index and the above-mentioned solar, geomagnetic, and interplanetary indices. It is found that this solar activity index, analyzed jointly with other solar activity, interplanetary parameters, and geomagnetic activity indices, shows a hysteresis phenomenon. It is observed that these parameters follow different paths for the ascending and the descending phases of solar cycle 23. It is noticed that the hysteresis phenomenon represents a clue in the search for physical processes responsi...

  20. Myocardial first-pass perfusion imaging with hybrid-EPI: frequency-offsets and potential artefacts

    OpenAIRE

    Ferreira Pedro F; Gatehouse Peter D; Firmin David N

    2012-01-01

    Abstract Background First-pass myocardial perfusion is often imaged with a tailored hybrid centric interleaved echo-planar-imaging sequence, providing rapid image acquisition with good contrast enhancement. The centric interleaved phase-encode order minimises the effective time-of-echo but it is sensitive to frequency-offsets. This short article aims to show possible artefacts that might originate with this sequence, in the context of first-pass perfusion imaging, when frequency-offsets are p...

  1. Myocardial first-pass perfusion imaging with hybrid-EPI: frequency-offsets and potential artefacts

    Directory of Open Access Journals (Sweden)

    Ferreira Pedro F

    2012-06-01

    Full Text Available Abstract Background First-pass myocardial perfusion is often imaged with a tailored hybrid centric interleaved echo-planar-imaging sequence, providing rapid image acquisition with good contrast enhancement. The centric interleaved phase-encode order minimises the effective time-of-echo but it is sensitive to frequency-offsets. This short article aims to show possible artefacts that might originate with this sequence, in the context of first-pass perfusion imaging, when frequency-offsets are present. Non-uniform magnitude modulation effects were also analysed. Methods Numerical and phantom simulations were used to illustrate the effects of frequency-offsets and non-uniform magnitude modulation with this sequence in a typical perfusion protocol. In vivo data was post-processed to analyse the h-EPI’s sensitivity to the frequency-offsets. Results The centric phase-order was shown to be highly sensitive to frequency-offsets due to its symmetrical phase slope. Resulting artefacts include blurring, and splitting of the image into two identical copies along the phase-encode direction. It was also shown that frequency-offsets can introduce signal loss and ghosting of the right ventricle signal into the myocardium. The in vivo results were confirmed by numerical and phantom simulations. Magnitude modulation effects were found to be small. Conclusions Imaging first-pass myocardial perfusion with an hybrid centric echo-planar-imaging sequence can be corrupted with ghosting and splitting of the image due to frequency-offsets.

  2. First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background.

    Science.gov (United States)

    Follin, Brent; Knox, Lloyd; Millea, Marius; Pan, Zhen

    2015-08-28

    The unimpeded relativistic propagation of cosmological neutrinos prior to recombination of the baryon-photon plasma alters gravitational potentials and therefore the details of the time-dependent gravitational driving of acoustic oscillations. We report here a first detection of the resulting shifts in the temporal phase of the oscillations, which we infer from their signature in the cosmic microwave background temperature power spectrum. PMID:26371637

  3. Temporal Offsets Between Maximum CME Speed Index and Solar, Geomagnetic, and Interplanetary Indicators During Solar Cycle 23 and the Ascending Phase of Cycle 24

    Science.gov (United States)

    Özgüç, A.; Kilcik, A.; Georgieva, K.; Kirov, B.

    2016-05-01

    On the basis of a morphological analysis of yearly values of the maximum coronal mass ejection (CME) speed index, the sunspot number and total sunspot area, sunspot magnetic field, and solar flare index, the solar wind speed and interplanetary magnetic field strength, and the geomagnetic Ap and D_{st} indices, we point out the particularities of solar and geomagnetic activity during the last Cycle 23, the long minimum that followed it, and the ascending branch of Cycle 24. We also analyze the temporal offset between the maximum CME speed index and the above-mentioned solar, geomagnetic, and interplanetary indices. It is found that this solar activity index, analyzed jointly with other solar activity, interplanetary parameters, and geomagnetic activity indices, shows a hysteresis phenomenon. It is observed that these parameters follow different paths for the ascending and descending phases of Cycle 23. The hysteresis phenomenon represents a clue in the search for physical processes responsible for linking the solar activity to near-Earth and geomagnetic responses.

  4. Offsets - An opportunity of Financing

    International Nuclear Information System (INIS)

    Nuclear Research Reactors sometimes need to implement projects to upgrade, revamp or convert their reactor, acquire new fuel elements, etc. However, as their activities are mainly of noncommercial nature, they sometimes lack of financial resources to implement these projects by themselves. Several solutions exist: loans, governmental budget, subsidies from international organizations (IAEA). Offsets are another source of financing. They also are free of charge for the reactor. The objective of offsets is to Identify, implement and finance projects that: directly create or sustain a local economic activity of high-added value, would not have happened without the Obligor's intervention, and are of crucial importance given the country's political background (favor employment, technology transfers, training and education, research and development, etc.). Companies worldwide are willing to finance local projects to fulfill their Offset Obligation. Local organizations or institutions are willing to invest to increase their activities but lack of financial resources. Offset regulations are an opportunity on both sides and are free for the local organization. The monetary value of an Offset obligation is calculated as a percentage of the main contract price (or as a percentage of the imported part value). That percentage depends on the Country's legislation and on the nature of the main contract (defense or civilian). This value has to be compensated by an equivalent economic value (a Project's cost is different from its value). There is two ways of assessing a value: - Political aspects: The Project is of political importance for the country (development of an export capability, technology and/or know-how transfers) and the project in line with the country's political priorities (employment, research, international presence, etc.). - Economic benefits: the project directly sustains or creates additional activities, turnover, R and D, employment, etc. It benefits directly

  5. Offset unfurlable antenna, phase 1

    Science.gov (United States)

    1984-03-01

    The configuration, technology requirements, development aspects, and experimental activities for satellite reflectors for fixed and mobile communications and television broadcasting are outlined. A 4.5 m antenna for 4 GHz, and an 8 m antenna for 1.6 GHz were studied, assuming an L-Sat type satellite. A radial rib concept with auxiliary adjustment ribs, and a three dimensional scissors concept (spatial framework) with mesh adjustment elements were compared concerning mass, stowage, volume, development risk, and reliability. For antennas of diameter from 3.6 to 12 m (12 GHz to 800 MHz) the radial rib reflector is preferred. Main advantages (with rib folding for larger reflector diameters) are: lower costs; less critical technology problems; lower development risks; high deployment reliability; lightweight intermediate ribs can adapt surface accuracy to higher frequency requirements (high application flexibility); and folded main ribs provide high package capability at larger diameters. The scissors concept is advantageous for applications requiring reflectors from 12 m diameter onwards.

  6. Offset drilling obligations

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, K.D.; Kalmakoff, J.J. [Kanuka Thuringer, Regina, SK (Canada)

    1998-12-31

    A review of the `offset well` clause found in freehold and Crown natural gas and petroleum leases was presented. The objective was to provide lessors and lessees with a clear understanding of the rights and obligations associated with offset wells. It was noted that offset well obligations vary according to the form of lease used, the type of offsetting well, the regulatory regime and the geophysical characteristics of the producing formation. Some suggestions were made as to how current versions of the offset well clause can be amended to overcome some of the problems encountered in applying the clause to an offset horizontal well that has been drilled on adjoining lands. Failure to resolve the new issues presented by horizontal drilling technology in terms of documentation, which records respective rights and obligations on the basis of generally accepted principles, will result in large numbers of conflicts and unnecessary litigation. 144 refs., 1 fig.

  7. Are environmental offsets indulgences?

    OpenAIRE

    Bougherara, Douadia; Costa, Sandrine; Teisl, Mario

    2010-01-01

    Environmental offsetting is a concept whereby a company can offset its environmental impacts by paying for another party to reduce its environmental impacts. Offsets are designed for greenhouse gases emissions (carbon) and biodiversity. Though the concept is new in the debate, it relies on the idea common to environmental economists of flexibility and cost efficiency where the firms that have the lowest pollution abatement costs reduce more pollution than firms that have high abatement costs....

  8. Blinking Phase-Change Nanocapsules Enable Background-Free Ultrasound Imaging.

    Science.gov (United States)

    Hannah, Alexander S; Luke, Geoffrey P; Emelianov, Stanislav Y

    2016-01-01

    Microbubbles are widely used as contrast agents to improve the diagnostic capability of conventional, highly speckled, low-contrast ultrasound imaging. However, while microbubbles can be used for molecular imaging, these agents are limited to the vascular space due to their large size (> 1 μm). Smaller microbubbles are desired but their ultrasound visualization is limited due to lower echogenicity or higher resonant frequencies. Here we present nanometer scale, phase changing, blinking nanocapsules (BLInCs), which can be repeatedly optically triggered to provide transient contrast and enable background-free ultrasound imaging. In response to irradiation by near-infrared laser pulses, the BLInCs undergo cycles of rapid vaporization followed by recondensation into their native liquid state at body temperature. High frame rate ultrasound imaging measures the dynamic echogenicity changes associated with these controllable, periodic phase transitions. Using a newly developed image processing algorithm, the blinking particles are distinguished from tissue, providing a background-free image of the BLInCs while the underlying B-mode ultrasound image is used as an anatomical reference of the tissue. We demonstrate the function of BLInCs and the associated imaging technique in a tissue-mimicking phantom and in vivo for the identification of the sentinel lymph node. Our studies indicate that BLInCs may become a powerful tool to identify biological targets using a conventional ultrasound imaging system. PMID:27570556

  9. Neutron background signal in superheated droplet detectors of the Phase II SIMPLE dark matter search

    CERN Document Server

    Fernandes, A C; Felizardo, M; Girard, T A; Ramos, A R; Marques, J G; Prudêncio, M I; Marques, R; Carvalho, F P; Lázaro, I

    2015-01-01

    The simulation of the neutron background for Phase II of the SIMPLE direct dark matter search experiment is described, including further improvements relatively to previously reported data. Spontaneous fission and decay-induced (\\alpha,n) reactions originating in $^{238}$U and $^{232}$Th naturally present in the experiment materials were considered. The model employs the Monte Carlo MCNP neutron transport code, using a realistic geometry description and measured radioassays and material compositions as input. Tabled (\\alpha,n) yields, measured detection efficiencies and evaluated cross section data were used. The energy distribution of the recoiling nuclei is dealt with a distinct code. A thorough uncertainty analysis of the simulated results is performed that addresses statistical and most non-statistical uncertainties. The estimated recoil event rate is 0.367 $\\pm$ 0.002(stat.) $\\pm$ 0.064 (non-stat.) evt/kgd, a 10$\\%$ increase in the previous reported result.

  10. Electron/gamma and alpha backgrounds in CRESST-II Phase 2

    CERN Document Server

    Strauss, R; Bento, A; Bucci, C; Canonica, L; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Münster, A; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schäffner, K; Schieck, J; Scholl, S; Schönert, S; Seidel, W; Sivers, M v; Stodolsky, L; Strandhagen, C; Tanzke, A; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2014-01-01

    The experiment CRESST-II aims at the detection of dark matter with scintillating CaWO$_4$ crystals operated as cryogenic detectors. Recent results on spin-independent WIMP-nucleon scattering from the CRESST-II Phase 2 allowed to probe a new region of parameter space for WIMP masses below 3$\\,$GeV/c$^2$. This sensitivity was achieved after background levels were reduced significantly. We present extensive background studies of a CaWO$_4$ crystal, called TUM40, grown at the Technische Universit\\"at M\\"unchen. The average beta/gamma rate of 3.44/[kg$\\,$keV$\\,$day] (1-40$\\,$keV) and the total intrinsic alpha activity from natural decay chains of $3.08\\pm0.04\\,$mBq/kg are the lowest reported for CaWO$_4$ detectors. Contributions of gamma lines resulting from cosmogenic activation, external X-rays and intrinsic beta emitters are investigated in detail.

  11. GERDA phase II detectors: Behind the production and characterisation at low background conditions

    International Nuclear Information System (INIS)

    The low background GERmanium Detector Array (GERDA) at Laboratori Nazionali del Gran Sasso (LNGS) is designed to search for the rare neutrinoless double beta decay (0νββ) in 76Ge. Bare germanium diodes are operated in liquid argon which is used as coolant, as passive and soon active as well shield against external radiation. Currently, Phase I of the experiment is running using ∼15 kg of co-axial High Purity Germanium diodes. In order to increase the sensitivity of the experiment 30 Broad Energy Germanium (BEGe) diodes will be added within 2013. This presentation reviews the production chain of the new BEGe detectors from isotopic enrichment to diode production and testing. As demonstrated all steps were carefully planned in order to minimize the exposure of the enriched germanium to cosmic radiation. Following this premise, acceptance and characterisation measurement of the newly produced diodes have been performed within the HEROICA project in the Belgian underground laboratory HADES close to the diode manufacturer. The test program and the results from a subset of the recently terminated GERDA Phase II BEGe survey will be presented

  12. GERDA phase II detectors: Behind the production and characterisation at low background conditions

    Energy Technology Data Exchange (ETDEWEB)

    Maneschg, Werner [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Collaboration: GERDA Collaboration; and others

    2013-08-08

    The low background GERmanium Detector Array (GERDA) at Laboratori Nazionali del Gran Sasso (LNGS) is designed to search for the rare neutrinoless double beta decay (0νββ) in {sup 76}Ge. Bare germanium diodes are operated in liquid argon which is used as coolant, as passive and soon active as well shield against external radiation. Currently, Phase I of the experiment is running using ∼15 kg of co-axial High Purity Germanium diodes. In order to increase the sensitivity of the experiment 30 Broad Energy Germanium (BEGe) diodes will be added within 2013. This presentation reviews the production chain of the new BEGe detectors from isotopic enrichment to diode production and testing. As demonstrated all steps were carefully planned in order to minimize the exposure of the enriched germanium to cosmic radiation. Following this premise, acceptance and characterisation measurement of the newly produced diodes have been performed within the HEROICA project in the Belgian underground laboratory HADES close to the diode manufacturer. The test program and the results from a subset of the recently terminated GERDA Phase II BEGe survey will be presented.

  13. GERDA phase II detectors: Behind the production and characterisation at low background conditions

    Science.gov (United States)

    Maneschg, Werner; Gerda Collaboration

    2013-08-01

    The low background GERmanium Detector Array (GERDA) at Laboratori Nazionali del Gran Sasso (LNGS) is designed to search for the rare neutrinoless double beta decay (0νββ) in 76Ge. Bare germanium diodes are operated in liquid argon which is used as coolant, as passive and soon active as well shield against external radiation. Currently, Phase I of the experiment is running using ˜15 kg of co-axial High Purity Germanium diodes. In order to increase the sensitivity of the experiment 30 Broad Energy Germanium (BEGe) diodes will be added within 2013. This presentation reviews the production chain of the new BEGe detectors from isotopic enrichment to diode production and testing. As demonstrated all steps were carefully planned in order to minimize the exposure of the enriched germanium to cosmic radiation. Following this premise, acceptance and characterisation measurement of the newly produced diodes have been performed within the HEROICA project in the Belgian underground laboratory HADES close to the diode manufacturer. The test program and the results from a subset of the recently terminated GERDA Phase II BEGe survey will be presented.

  14. Critical point in the QCD phase diagram for extremely strong background magnetic fields

    Science.gov (United States)

    Endrödi, Gergely

    2015-07-01

    Lattice simulations have demonstrated that a background (electro)magnetic field reduces the chiral/deconfinement transition temperature of quantum chromodynamics for eB Polyakov loop and in a suppression of the light quark condensates (inverse magnetic catalysis) in the transition region. In this paper, we report on lattice simulations of 1 + 1 + 1-flavor QCD at an unprecedentedly high value of the magnetic field eB = 3 .25 GeV2. Based on the behavior of various observables, it is shown that even at this extremely strong field, inverse magnetic catalysis prevails and the transition, albeit becoming sharper, remains an analytic crossover. In addition, we develop an algorithm to directly simulate the asymptotically strong magnetic field limit of QCD. We find strong evidence for a first-order deconfinement phase transition in this limiting theory, implying the presence of a critical point in the QCD phase diagram. Based on the available lattice data, we estimate the location of the critical point.

  15. Critical endpoint in the QCD phase diagram for extremely strong background magnetic fields

    CERN Document Server

    Endrodi, Gergely

    2015-01-01

    Lattice simulations have demonstrated that a background (electro)magnetic field reduces the chiral/deconfinement transition temperature of quantum chromodynamics for eB < 1 GeV^2. On the level of observables, this reduction manifests itself in an enhancement of the Polyakov loop and in a suppression of the light quark condensates (inverse magnetic catalysis) in the transition region. In this paper, we report on lattice simulations of 1+1+1-flavor QCD at an unprecedentedly high value of the magnetic field eB = 3.25 GeV^2. Based on the behavior of various observables, it is shown that even at this extremely strong field, inverse magnetic catalysis prevails and the transition, albeit becoming sharper, remains an analytic crossover. In addition, we develop an algorithm to directly simulate the asymptotically strong magnetic field limit of QCD. We find strong evidence for a first-order deconfinement phase transition in this limiting theory, implying the presence of a critical endpoint in the QCD phase diagram. ...

  16. Phase I Final Report: Ultra-Low Background Alpha Activity Counter

    International Nuclear Information System (INIS)

    easily distinguish between these two risetimes and thereby count only alpha particles emitted by the sample. Alpha particles emitted from the sample tray are absorbed in the rear of the sample, so the tray's emissivity does not contribute to the background either. Extensions of the method to the counter's sidewalls similarly allow us to reject alpha particles emitted from the sidewalls. We can thus able obtain background rates over a factor of 1000 lower than in conventional instruments without active background rejection. Extending this principle to count at the 0.00001 alpha/cm2/hour, level encounters difficulties because there will typically be only 2.4 alpha particles per square meter per day. Since about 6 counts are required to measure activity at the 95% confidence level, large sample areas are required to make measurements in reasonable times. Unfortunately, increasing the counter's anode area to a square meter raises its capacitance so much that the preamplifier noise levels swamp the alpha particle signals and make counting impossible. In this SBIR we worked to solve this dilemma by segmenting the single large area electrode into several smaller, lower capacitance electrodes that could still detect the alpha particles reliably. Each electrode would have its own electronic and we would capture signals from all of them in coincidence (since an alpha track might well deposit charge on more than one electrode), a technique in which XIA is experienced. Therefore, in Phase I we worked to show proof of principle by subdividing our original 1,800 cm2 electrode into 4 square segments, each 625 cm2 and demonstrating that signal noise on individual channels reduced as expected. Because the Phase II counter with a 1 m2 segmented anode would require 16 segments plus a segmented guard as well, we also designed low cost signal processing electronics to instrument it in Phase II. Our Phase I effort met our major proof of principle goals. In particular, reducing the anode size

  17. Frequency-offset separated oscillatory fields

    Science.gov (United States)

    Vutha, A. C.; Hessels, E. A.

    2015-11-01

    A frequency-offset separated-oscillatory-field technique is presented. The technique is a modification of the Ramsey method of separated oscillatory fields [Phys. Rev. 76, 996 (1949), 10.1103/PhysRev.76.996], in which the frequencies of the two separated oscillatory fields are slightly offset from each other, so that the relative phase of the two fields varies continuously with time. With this technique, the detection signal oscillates in time at the offset frequency, and the resonance frequency is obtained by using a simple straight-line fit of the phase of this signal. The technique has the advantages of being insensitive to the frequency response of the experimental system, of being sensitive only to noise at the offset frequency, and of allowing systematic effects to be more cleanly resolved due to the simple lineshape.

  18. Cosmological Backgrounds of Gravitational Waves and eLISA/NGO: Phase Transitions, Cosmic Strings and Other Sources

    CERN Document Server

    Binétruy, Pierre; Caprini, Chiara; Dufaux, Jean-François

    2012-01-01

    We review the main cosmological backgrounds of gravitational waves accessible to detectors in space sensitive to the range $10^{-4}$ to $10^{-1}$ Hz, with a special emphasis on those backgrounds due to phase transitions or networks of cosmic strings. We apply this to identify the scientific potential of the NGO/eLISA mission of ESA, regarding the detectability of such cosmological backgrounds.

  19. Anatomical background noise power spectrum in differential phase contrast breast images

    Science.gov (United States)

    Garrett, John; Ge, Yongshuai; Li, Ke; Chen, Guang-Hong

    2015-03-01

    In x-ray breast imaging, the anatomical noise background of the breast has a significant impact on the detection of lesions and other features of interest. This anatomical noise is typically characterized by a parameter, β, which describes a power law dependence of anatomical noise on spatial frequency (the shape of the anatomical noise power spectrum). Large values of β have been shown to reduce human detection performance, and in conventional mammography typical values of β are around 3.2. Recently, x-ray differential phase contrast (DPC) and the associated dark field imaging methods have received considerable attention as possible supplements to absorption imaging for breast cancer diagnosis. However, the impact of these additional contrast mechanisms on lesion detection is not yet well understood. In order to better understand the utility of these new methods, we measured the β indices for absorption, DPC, and dark field images in 15 cadaver breast specimens using a benchtop DPC imaging system. We found that the measured β value for absorption was consistent with the literature for mammographic acquisitions (β = 3.61±0.49), but that both DPC and dark field images had much lower values of β (β = 2.54±0.75 for DPC and β = 1.44±0.49 for dark field). In addition, visual inspection showed greatly reduced anatomical background in both DPC and dark field images. These promising results suggest that DPC and dark field imaging may help provide improved lesion detection in breast imaging, particularly for those patients with dense breasts, in whom anatomical noise is a major limiting factor in identifying malignancies.

  20. Cosmological backgrounds of gravitational waves and eLISA/NGO: phase transitions, cosmic strings and other sources

    International Nuclear Information System (INIS)

    We review several cosmological backgrounds of gravitational waves accessible to direct-detection experiments, with a special emphasis on those backgrounds due to first-order phase transitions and networks of cosmic (super-)strings. For these two particular sources, we revisit in detail the computation of the gravitational wave background and improve the results of previous works in the literature. We apply our results to identify the scientific potential of the NGO/eLISA mission of ESA regarding the detectability of cosmological backgrounds

  1. Policy Development for Biodiversity Offsets: A Review of Offset Frameworks

    Science.gov (United States)

    McKenney, Bruce A.; Kiesecker, Joseph M.

    2010-01-01

    Biodiversity offsets seek to compensate for residual environmental impacts of planned developments after appropriate steps have been taken to avoid, minimize or restore impacts on site. Offsets are emerging as an increasingly employed mechanism for achieving net environmental benefits, with offset policies being advanced in a wide range of countries (i.e., United States, Australia, Brazil, Colombia, and South Africa). To support policy development for biodiversity offsets, we review a set of major offset policy frameworks—US wetlands mitigation, US conservation banking, EU Natura 2000, Australian offset policies in New South Wales, Victoria, and Western Australia, and Brazilian industrial and forest offsets. We compare how the frameworks define offset policy goals, approach the mitigation process, and address six key issues for implementing offsets: (1) equivalence of project impacts with offset gains; (2) location of the offset relative to the impact site; (3) “additionality” (a new contribution to conservation) and acceptable types of offsets; (4) timing of project impacts versus offset benefits; (5) offset duration and compliance; and (6) “currency” and mitigation replacement ratios. We find substantial policy commonalities that may serve as a sound basis for future development of biodiversity offsets policy. We also identify issues requiring further policy guidance, including how best to: (1) ensure conformance with the mitigation hierarchy; (2) identify the most environmentally preferable offsets within a landscape context; and (3) determine appropriate mitigation replacement ratios.

  2. Policy development for biodiversity offsets: a review of offset frameworks.

    Science.gov (United States)

    McKenney, Bruce A; Kiesecker, Joseph M

    2010-01-01

    Biodiversity offsets seek to compensate for residual environmental impacts of planned developments after appropriate steps have been taken to avoid, minimize or restore impacts on site. Offsets are emerging as an increasingly employed mechanism for achieving net environmental benefits, with offset policies being advanced in a wide range of countries (i.e., United States, Australia, Brazil, Colombia, and South Africa). To support policy development for biodiversity offsets, we review a set of major offset policy frameworks-US wetlands mitigation, US conservation banking, EU Natura 2000, Australian offset policies in New South Wales, Victoria, and Western Australia, and Brazilian industrial and forest offsets. We compare how the frameworks define offset policy goals, approach the mitigation process, and address six key issues for implementing offsets: (1) equivalence of project impacts with offset gains; (2) location of the offset relative to the impact site; (3) "additionality" (a new contribution to conservation) and acceptable types of offsets; (4) timing of project impacts versus offset benefits; (5) offset duration and compliance; and (6) "currency" and mitigation replacement ratios. We find substantial policy commonalities that may serve as a sound basis for future development of biodiversity offsets policy. We also identify issues requiring further policy guidance, including how best to: (1) ensure conformance with the mitigation hierarchy; (2) identify the most environmentally preferable offsets within a landscape context; and (3) determine appropriate mitigation replacement ratios.

  3. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  4. Dynamical Background for L-G Phase Transition in QHD-I Model

    Institute of Scientific and Technical Information of China (English)

    JIN Meng; CHEN Ji-Sheng; LI Jia-Rong

    2003-01-01

    Starting from the QHD-I model, the nucleon-nucleon interaction potential in hot/dense nuclear matter is studied. We find that the attractive and repulsive Yukawa potential between nucleons is modified by the variation of Debye mass directly and, especially, the nucleon system described by this Yukawa potential will be unbounded at some critical T and μ. The critical point we get accords with that of L-G phase transition given by the P - pB phase diagram.

  5. A Novel Offset Fresnel Zone Plate Antenna

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel offset Fresnel Zone Plate reflector Antenna (FZPA) is proposed, the phase correcting zone of this FZPA is elliptic. Based on Physical Optics Method, the focusing characteristics of the reflector are analyzed. The comparison of this new FZPA with the circular FZPA and Mawzones FZPA is made.

  6. Phase speed saturation of Farley-Buneman waves due to stochastic, self-induced fluctuations in the background flow

    Science.gov (United States)

    Rojas, E. L.; Young, M. A.; Hysell, D. L.

    2016-06-01

    The phase speed saturation of Farley-Buneman waves is studied as an interaction with the random turbulent fluctuations in the background. We used the formalism of stochastic differential equations to model the complex interactions with a linearized system plus a stochastic term. Applying an averaging technique, we can obtain an augmented linear system that depends on the random behavior of the waves. The results show that following this approach we can obtain phase velocities that saturate close to the ion acoustic speed (Cs). This approach seems promising for the study of the influence of plasma turbulence generated by different kinds of instabilities on the mean state of the ionosphere.

  7. More General Optimal Offset Assignment

    Directory of Open Access Journals (Sweden)

    Sven Mallach

    2015-06-01

    Full Text Available This manuscript presents exact approaches to the general offset assignment problem arising in the address code generation phase of compilers for application-specific processors. First, integer programming models for architecture-dependent and theoretically motivated special cases of the problem are established. Then, these models are extended to provide the first widely applicable formulations for the most general problem setting, supporting processors with several address registers and complex addressing capabilities. Existing heuristics are similarly extended and practical applicability of the proposed methods is demonstrated by experimental evaluation using an established and large benchmark set. The experiments allow us to study the impact of exploiting more complex memory addressing capabilities on the address computation costs of real-world programs. We also show how to integrate operand reordering techniques for commutative instructions into existing solution approaches.

  8. Keeping the Background Low: Production and Testing of the GERDA Phase II Detectors

    International Nuclear Information System (INIS)

    The Germanium Detector Array (GERDA) experiment at the INFN Laboratori Nazionali del Gran Sasso searches for neutrinoless double beta decay of 76Ge. The first phase using ∼15 kg of coaxial germanium detectors is ongoing. In a second phase, additional ∼20 kg of newly produced Broad Energy Germanium (BEGe) detectors will be deployed. To limit the generation of cosmogenically induced radioisotopes, the exposure of the germanium to cosmic radiation during the detector production and testing was minimized. An acceptance and characterization campaign of the newly produced detectors was carried out at the HEROICA facility in the HADES underground laboratory in Mol, Belgium. An overview over the complete production process, from isotopic enrichment of the material to the detector testing protocol, is given. (authors)

  9. Research And Investigation To Establish The Database Of Environment Radiation Background For Vietnam (Phase 2009 -2011)

    International Nuclear Information System (INIS)

    Setting up data base of natural radiation background serves for planning socio-economics development in a province as well as the whole country and estimating annual effective dose of population. Beside external irradiation dose caused by the natural radioisotopes in the series 238U, 232Th and 40K in soil, population has been received internal dose caused by the above radioisotopes taken in the body from several ways. In order to complete the database of national radiation background and go to estimate annual effective radiation dose of population in the whole country, this project focus to carry out the works as following: (i) Setting up database of radiation background in the whole country: 150 soil samples that collected in the districts of 46 provinces have been analyzed. The average activity concentration of 238U, 232Th and 40K are 37.86 Bq/kg, 58.88 Bq/kg and 462.78 Bq/kg, respectively. The outdoor, indoor and total annual effective doses are calculated: 0.087±0.036 mSv; 0.488±0.202 mSv and 0.576± 0.240 mSv, respectively. (ii) Setting up database of radiation background of province Ninh Thuan and Quang Nam: The detailed database of radiation background of all villages in Ninh Thuan and Quang Nam has been established. 84 soil samples in Ninh Thuan and 311 in Quang Nam were collected for analyze. The indoor and outdoor radon concentration at sampling positions has been measured. The average activities of 238U, 232Th, 40K, and 222Rn isotopes in Ninh Thuan are reported: 33.50 Bq/kg, 55.43 Bq/kg, 701.12 Bq/kg and 12.1 Bq/m3, 9.5 Bq/m3, respectively. The outdoor, indoor and total annual effective doses in Ninh Thuan are calculated: 0.095±0.029 mSv; 0.529±0.162 mSv and 0.624± 0.382 mSv, respectively. The average activities of 238U, 232Th, 40K, and 222Rn isotopes in Quang Nam are reported: 44.47 Bq/kg, 52.68 Bq/kg, 459.33 Bq/kg, 18.0 Bq/m3. The outdoor, indoor and total annual effective doses are calculated: 0.086±0.039 mSv; 0.482±0.216 mSv and 0.568± 0

  10. Background Characterization and Discrimination in the Final Analysis of the CDMS II Phase of the Cryogenic Dark Matter Search

    Energy Technology Data Exchange (ETDEWEB)

    Fritts, Matthew C. [Univ. of Minnesota, Minneapolis, MN (United States)

    2011-02-01

    The Cryogenic Dark Matter Search (CDMS) is designed to detectWeakly-Interacting Massive Particles (WIMPs) in the Milky Way halo. The phase known as CDMS II was performed in the Soudan Underground Laboratory. The final set of CDMS II data, collected in 2007-8 and referred to as Runs 125-8, represents the largest exposure to date for the experiment. We seek collisions between WIMPs and atomic nuclei in disk-shaped germanium and silicon detectors. A key design feature is to keep the rate of collisions from known particles producing WIMP-like signals very small. The largest category of such background is interactions with electrons in the detectors that occur very close to one of the faces of the detector. The next largest category is collisions between energetic neutrons that bypass the experimental shielding and nuclei in the detectors. Analytical efforts to discriminate these backgrounds and to estimate the rate at which such discrimination fails have been refined and improved throughout each phase of CDMS. Next-generation detectors for future phases of CDMS require testing at cryogenic test facilities. One such facility was developed at the University of Minnesota in 2007 and has been used continuously since then to test detectors for the next phase of the experiment, known as SuperCDMS.

  11. Seismic survey in southeastern Socorro Island: Background noise measurements, seismic events, and T phases

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Raul W [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Galindo, Marta [Comprehensive Nuclear-Test-Ban Treaty Organization, IMS, Vienna (Austria); Pacheco, Javier F; Iglesias, Arturo; Teran, Luis F [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Barreda, Jose L; Coba, Carlos [Facultad de Ingenieria, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

    2005-01-15

    We carried out a seismic survey and installed five portable, broadband seismometers in the southeastern corner of Socorro Island during June 1999. Power spectral densities for all five sites were relatively noisy when compared to reference curves around the world. Power spectral densities remain constant regardless of the time of day, or the day of the week. Cultural noise at the island is very small. Quiet and noisy sites were identified to determine the best location of the T phase station to be installed jointly by the Universidad Nacional Autonoma de Mexico and the Comprehensive Nuclear-Test-Ban Treaty Organization. During the survey six earthquakes were recorded at epicentral distances between 42 km and 2202 km, with magnitudes between 2.8 and 7.0. Two small earthquakes (M{sub c} = 2.8 and 3.3) occurred on the Clarion Fracture Zone. The four largest and more distant earthquakes produced T waves. One T wave from an epicenter near the coast of Guatemala had a duration of about 100 s and a frequency content between 2 and 8 Hz, with maximum amplitude at about 4.75 Hz. The Tehuacan earthquake of June 15, 1999 (M{sub w} = 7.0) produced arrivals of P {yields} T and S {yields} T waves, with energy between 2 Hz and 3.75 Hz. The earthquake occurred inland within the subducted Cocos plate at a depth of 60 km; a significant portion of the path was continental. Seismic P and S waves probably propagated upward in the subducted slab, and were converted to acoustic energy at the continental slope. Total duration of the T phase is close to 500 s and reaches its maximum amplitude about 200 s after the P {yields} T arrival. The T wave contains energy at frequencies between 2 and 10 Hz and reaches its maximum amplitude at about 2.5 Hz. T phases were also recorded from two earthquakes in Guerrero, Mexico and in the Rivera Fracture Zone. [Spanish] En junio de 1999 instalamos cinco sismometros portatiles de banda ancha en el sureste de la Isla Socorro. Se encontro que las densidades

  12. Quadrupole to BPM offset determination in Indus-2

    International Nuclear Information System (INIS)

    A feasibility of finding the quadrupole to BPM offset using beam based alignment (BBA) technique in Indus-2 has been studied. The measurements of the offsets between BPM and quadrupoles could be performed by using quadratic fitting for the minima of the orbit response w. r. t. changes in the quadrupole strengths. These offsets will be integrated to the orbit data during closed orbit correction. There are 72 quadrupoles and 56 BPMs in Indus-2. However the assessment of Quad-BPM offsets is not feasible in some cases due to non-availability of BPM adjacent to quadrupole and also in some cases because of a large phase advance between quadrupole and nearby BPM. Here single corrector method is used to obtain these offsets and assumed the current of each quadrupole can be varied independently. A graphical user interface (GUI) is developed in MATLAB for the use of BBA in Indus-2. (author)

  13. Success Factors in Offset Deals: A Case Study Based Examination

    Directory of Open Access Journals (Sweden)

    Heinz Kirchwehm

    2014-04-01

    Full Text Available The requests for offset obligations occurs primarily in the area of arms imports and covers the full range of industrial and commercial benefits that companies provide to foreign governments as inducements or conditions for the purchase of military goods and services. Increasingly, all major contracts ask for offset obligations. They are now key differentiators in major contracts and it is a fast growing market. For the suppliers, offsets are a key differentiator in earning new business and therefore should be accepted that much accurateness is put on the successful execution of the offset projects. Nevertheless, it comes to problems during the project phase and sometimes we’ve the situation that a offset project failed. The aim of this paper is to exam which success- giving factors are exists in the offset related interaction between buyer, seller and participating industry. The data for this investigation were obtained from secondary sources which were mainly accessible via internet. After data collection, an analysis was performed which was based on the context of this paper and also in connection with the chosen case study: Saudi Arabia. As a result of this analysis can be derived several success factors, which could be also seen as the foundation for an optimized execution of offset obligations. The paper concludes with a reflection of the investigation approach and as well with a classification of the subject offset. Furthermore the results of the analyzes are summarized and an outlook for further researches is given.

  14. Cap and trade offsets regulation - consultation paper

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Due to increasing concerns about the environment, British Columbia has committed to reducing its 2007 greenhouse gas emissions levels by 33% in 2020 and 80% in 2050. To reach those objectives, emissions trading and offset regulations are being developed by the Climate Action Secretariat. The aim of this document is to present a first draft of the regulations to the various stakeholders, including First Nations and the general public, together with the proposed offset eligibility criteria and related process, and to get their feedback. This document is itself part of the 5-phase process of developing the regulations. Following the 45 days during which comments on the proposed regulation were sought, the climate action secretariat will complete legal drafting of the regulations, drawing on help from this stakeholder input, and the regulation will subsequently be implemented. An accompanying response form was attached to this consultation paper.

  15. Temperature Induced Voltage Offset Drifts in Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Lukco, Dorothy; Nguyen, Vu; Savrun, Ender

    2012-01-01

    We report the reduction of transient drifts in the zero pressure offset voltage in silicon carbide (SiC) pressure sensors when operating at 600 C. The previously observed maximum drift of +/- 10 mV of the reference offset voltage at 600 C was reduced to within +/- 5 mV. The offset voltage drifts and bridge resistance changes over time at test temperature are explained in terms of the microstructure and phase changes occurring within the contact metallization, as analyzed by Auger electron spectroscopy and field emission scanning electron microscopy. The results have helped to identify the upper temperature reliable operational limit of this particular metallization scheme to be 605 C.

  16. Asymmetric dynamics of adaptation after onset and offset of flicker

    NARCIS (Netherlands)

    Snippe, H.P.; Poot, L.; Hateren, J.H. van

    2004-01-01

    We measured human psychophysical detection thresholds for test pulses which are superimposed on spatially homogeneous backgrounds that have abrupt onsets and offsets of high-contrast 25 Hz flicker. After the onset of the background flicker, test thresholds reach their steady-state levels within 20-6

  17. 5 CFR 179.307 - Administrative offset.

    Science.gov (United States)

    2010-01-01

    ... administrative offset regulations, and the applicable provisions of 4 CFR part 102 with respect to providing the debtor with due process. (c) Request for offset from a Federal agency: When administrative offset is... administrative offset regulations and with the applicable provisions of 4 CFR part 102, including providing...

  18. 26 CFR 1.812-5 - Offset.

    Science.gov (United States)

    2010-04-01

    ... by the following example: Example. In computing the operations loss deduction for 1960, Y, a life... and Loss from Operations § 1.812-5 Offset. (a) Offset defined. Section 812(d) defines the term “offset... offset is only that portion of the increase in the operations loss deduction for the taxable year...

  19. Background field removal technique using regularization enabled sophisticated harmonic artifact reduction for phase data with varying kernel sizes.

    Science.gov (United States)

    Kan, Hirohito; Kasai, Harumasa; Arai, Nobuyuki; Kunitomo, Hiroshi; Hirose, Yasujiro; Shibamoto, Yuta

    2016-09-01

    An effective background field removal technique is desired for more accurate quantitative susceptibility mapping (QSM) prior to dipole inversion. The aim of this study was to evaluate the accuracy of regularization enabled sophisticated harmonic artifact reduction for phase data with varying spherical kernel sizes (REV-SHARP) method using a three-dimensional head phantom and human brain data. The proposed REV-SHARP method used the spherical mean value operation and Tikhonov regularization in the deconvolution process, with varying 2-14mm kernel sizes. The kernel sizes were gradually reduced, similar to the SHARP with varying spherical kernel (VSHARP) method. We determined the relative errors and relationships between the true local field and estimated local field in REV-SHARP, VSHARP, projection onto dipole fields (PDF), and regularization enabled SHARP (RESHARP). Human experiment was also conducted using REV-SHARP, VSHARP, PDF, and RESHARP. The relative errors in the numerical phantom study were 0.386, 0.448, 0.838, and 0.452 for REV-SHARP, VSHARP, PDF, and RESHARP. REV-SHARP result exhibited the highest correlation between the true local field and estimated local field. The linear regression slopes were 1.005, 1.124, 0.988, and 0.536 for REV-SHARP, VSHARP, PDF, and RESHARP in regions of interest on the three-dimensional head phantom. In human experiments, no obvious errors due to artifacts were present in REV-SHARP. The proposed REV-SHARP is a new method combined with variable spherical kernel size and Tikhonov regularization. This technique might make it possible to be more accurate backgroud field removal and help to achive better accuracy of QSM.

  20. On Bimodal Offset Cauchy Distribution

    Directory of Open Access Journals (Sweden)

    Girija S.V.S.

    2013-05-01

    Full Text Available The bivariate Cauchy distribution has received applications in many areas, including biological analyses, clinical trials, stochastic modeling of decreasing failure rate life components, study of labour turnover, queuing theory and reliability (Nayak (1987 and Lee and Gross (1991. In the study of biological analyses, clinical trials and reliability circular distributions will yield suitable results. Circular data arises in a number of different areas such as geological, meteorological, biological and industrial sciences. It is not suggestive to use standard statistical techniques to model circular data, due to the circular geometry of the sample space (p.2 Jammalamadaka and Sen Gupta (2001. It is possible to construct a circular model by transforming a bivariate linear random variate to just its directional component and the resultant model is called ‘offset distribution’. In the literature most of the available circular models were constructed by wrapping a linear model. In recent years some wrapped models were constructed by Dattatreya Rao et al (2007. Here an attempt is made to exploit method of offsetting on Bivariate Cauchy distribution to construct a circular model named by us “OFFSET CAUCHY DISTRIBUTION (OC”. The characteristic function of the Offset Cauchy model is derived and its characteristics are discussed.

  1. Examination of Newton's Method Used for Indirect Frequency Offset Estimation

    Directory of Open Access Journals (Sweden)

    J. Dzubera

    2007-09-01

    Full Text Available This paper deals with the topic of an indirect carrier frequency offset estimation and elimination. The main goal is to modify a conventional method as an attempt to develop a different approach and then to compare the performance of the modified method with the performance of the conventional one. The conventional approach is here represented by the gradient optimization method called the steepest descent. It is the base for the modification which utilizes Newton's method for the indirect carrier offset estimation. Both algorithms are implemented as phase-locked loops in a model of communication system. The simulation is processed in Matlab.

  2. Blind Estimation of Multiple Carrier Frequency Offsets

    CERN Document Server

    Yu, Yuanning; Poor, H Vincent; Koivunen, Visa

    2007-01-01

    Multiple carrier-frequency offsets (CFO) arise in a distributed antenna system, where data are transmitted simultaneously from multiple antennas. In such systems the received signal contains multiple CFOs due to mismatch between the local oscillators of transmitters and receiver. This results in a time-varying rotation of the data constellation, which needs to be compensated for at the receiver before symbol recovery. This paper proposes a new approach for blind CFO estimation and symbol recovery. The received base-band signal is over-sampled, and its polyphase components are used to formulate a virtual Multiple-Input Multiple-Output (MIMO) problem. By applying blind MIMO system estimation techniques, the system response is estimated and used to subsequently transform the multiple CFOs estimation problem into many independent single CFO estimation problems. Furthermore, an initial estimate of the CFO is obtained from the phase of the MIMO system response. The Cramer-Rao Lower bound is also derived, and the la...

  3. A NOVEL INTEGER FREQUENCY OFFSET ESTIMATOR FOR OFDM

    Institute of Scientific and Technical Information of China (English)

    Cai Xuelian; Li Jiandong; Li Changle; Chen Chen

    2005-01-01

    One of the principal disadvantages of Orthogonal Frequency Division Multiplexing (OFDM) is very sensitive to carrier frequency offset. The integer frequency offset has no effect on the orthogonality among the subcarriers, but it causes a circular shift and phase rotation of the received data symbols sequence, resulting in a Bit Error Rate(BER) of 0.5. In this paper,a novel integer frequency offset estimator for OFDM is derived based on maximum likelihood estimation technique and exploration of the differential relation between two consecutive OFDM data symbol sequences in frequency domain. Its performance is compared with the conventional method by computer simulations for the additive white Gaussian noise channel and a multipath fading channel. Simulation results show that the performance of the proposed estimator is better than the conventional estimator.

  4. Frequency-Offset Cartesian Feedback Based on Polyphase Difference Amplifiers.

    Science.gov (United States)

    Zanchi, Marta G; Pauly, John M; Scott, Greig C

    2010-05-01

    A modified Cartesian feedback method called "frequency-offset Cartesian feedback" and based on polyphase difference amplifiers is described that significantly reduces the problems associated with quadrature errors and DC-offsets in classic Cartesian feedback power amplifier control systems.In this method, the reference input and feedback signals are down-converted and compared at a low intermediate frequency (IF) instead of at DC. The polyphase difference amplifiers create a complex control bandwidth centered at this low IF, which is typically offset from DC by 200-1500 kHz. Consequently, the loop gain peak does not overlap DC where voltage offsets, drift, and local oscillator leakage create errors. Moreover, quadrature mismatch errors are significantly attenuated in the control bandwidth. Since the polyphase amplifiers selectively amplify the complex signals characterized by a +90° phase relationship representing positive frequency signals, the control system operates somewhat like single sideband (SSB) modulation. However, the approach still allows the same modulation bandwidth control as classic Cartesian feedback.In this paper, the behavior of the polyphase difference amplifier is described through both the results of simulations, based on a theoretical analysis of their architecture, and experiments. We then describe our first printed circuit board prototype of a frequency-offset Cartesian feedback transmitter and its performance in open and closed loop configuration. This approach should be especially useful in magnetic resonance imaging transmit array systems. PMID:20814450

  5. Deep geological disposal of nuclear fuel waste: background information and regulatory requirements regarding the concept assessment phase

    International Nuclear Information System (INIS)

    In their Joint Statement of August 1981, the governments of Canada and Ontario noted that the Nuclear Fuel Waste Program had been established to assure the safe and permanent disposal of radioactive waste from nuclear power reactors. The statement addressed the scope and schedule of the 'Concept Assessment Phase' of the Program, and identified the participating organizations and their responsibilities. The scope of this initial phase includes the development and assessment by Ontario Hydro and Atomic Energy of Canada Limited (AECL) of a disposal concept and its subsequent review by the regulatory agencies and government. The Atomic Energy Control Board (AECB), as lead regulatory agency is issuing this statement to outline its position with respect to evaluation of the concept

  6. Annual report on the Background Soil Characterization Project on the Oak Ridge Reservation, Oak Ridge, Tennessee: Results of Phase 1 investigation

    International Nuclear Information System (INIS)

    Many constituents of potential concern for human health occur naturally at low concentrations in undisturbed soils. The Background soil Characterization Project (BSCP) was undertaken to provide background concentration data on potential contaminants in natural soils on the Oak Ridge Reservation (ORR). The objectives of the BSCP are to provide baseline data for contaminated site assessment and estimates of potential human health risk associated with background concentrations of hazardous and other constituents in native soils. This report presents, evaluates, and documents data and results obtained in Phase I of the project. It is intended to be a stand-alone document for application and use in structuring and conducting remedial investigation and remedial action projects in the Environmental Restoration (ER) Program

  7. Annual report on the Background Soil Characterization Project on the Oak Ridge Reservation, Oak Ridge, Tennessee: Results of Phase 1 investigation

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, D.R.; Goddard, P.L.; Hatmaker, T.L.; Hook, L.A.; Jackson, B.L.; Kimbrough, C.W.; Lee, S.Y.; Lietzke, D.A.; McGin, C.W.; Nourse, B.D.; Schmoyer, R.L.; Shaw, R.A.; Stinnette, S.E.; Switek, J.; Wright, J.C. [Oak Ridge National Lab., TN (United States); Ammons, J.T.; Branson, J.L.; Burgoa, B.B. [Tennessee Univ., Knoxville, TN (United States). Dept. of Plant and Soil Science; Lietzke, D.A. [Lietzke (David A.), Rutledge, TN (United States)

    1993-05-01

    Many constituents of potential concern for human health occur naturally at low concentrations in undisturbed soils. The Background soil Characterization Project (BSCP) was undertaken to provide background concentration data on potential contaminants in natural soils on the Oak Ridge Reservation (ORR). The objectives of the BSCP are to provide baseline data for contaminated site assessment and estimates of potential human health risk associated with background concentrations of hazardous and other constituents in native soils. This report presents, evaluates, and documents data and results obtained in Phase I of the project. It is intended to be a stand-alone document for application and use in structuring and conducting remedial investigation and remedial action projects in the Environmental Restoration (ER) Program.

  8. Quark matter in a parallel electric and magnetic field background: Chiral phase transition and equilibration of chiral density

    Science.gov (United States)

    Ruggieri, M.; Peng, G. X.

    2016-05-01

    In this article, we study spontaneous chiral symmetry breaking for quark matter in the background of static and homogeneous parallel electric field E and magnetic field B . We use a Nambu-Jona-Lasinio model with a local kernel interaction to compute the relevant quantities to describe chiral symmetry breaking at a finite temperature for a wide range of E and B . We study the effect of this background on the inverse catalysis of chiral symmetry breaking for E and B of the same order of magnitude. We then focus on the effect of the equilibration of chiral density n5 , produced dynamically by an axial anomaly on the critical temperature. The equilibration of n5 , a consequence of chirality-flipping processes in the thermal bath, allows for the introduction of the chiral chemical potential μ5, which is computed self-consistently as a function of the temperature and field strength by coupling the number equation to the gap equation and solving the two within an expansion in E /T2 , B /T2 , and μ52/T2 . We find that even if chirality is produced and equilibrates within a relaxation time τM , it does not change drastically the thermodynamics, with particular reference to the inverse catalysis induced by the external fields, as long as the average μ5 at equilibrium is not too large.

  9. Quark Matter in a Parallel Electric and Magnetic Field Background: Equilibrated Chiral Density Effect on Chiral Phase Transition

    CERN Document Server

    Ruggieri, M

    2016-01-01

    In this article we study spontaneous chiral symmetry breaking for quark matter in the background of an electric-magnetic flux tube with static, homogeneous and parallel electric field $\\bm E$ and magnetic field $\\bm B$. We use a Nambu-Jona-Lasinio model with a local kernel interaction to compute the relevant quantities to describe chiral symmetry breaking at finite temperature for a wide range of $E$ and $B$. We study the effect of the flux tube background on inverse catalysis of chiral symmetry breaking for $E$ and $B$ of the same order of magnitude. We then focus on the effect of equilibration of chiral density, $n_5$, produced dynamically by axial anomaly on the critical temperature. The equilibration of $n_5$, a consequence of chirality flipping processes in the thermal bath, allows for the introduction of the chiral chemical potential, $\\mu_5$, which is computed self-consistently as a function of temperature and field strength by coupling the number equation to the gap equation. We find that even if chir...

  10. Impact of the vertical emission profiles on background gas-phase pollution simulated from the EMEP emissions over Europe

    Directory of Open Access Journals (Sweden)

    S. Mailler

    2013-06-01

    Full Text Available Five one-year air quality simulations over a domain covering Europe have been performed using the CHIMERE chemistry transport model and the EMEP emission dataset for Europe. These five simulations differ only by the representation of the effective emission heights for anthropogenic emissions: one has been run using the EMEP standard recommendations, three others with vertical injection profiles derived from the EMEP recommendations but multiplying the injection height by 0.75, 0.50 and 0.25, respectively, while the last one uses vertical profiles derived from the recent literature. It is shown that using injection heights lower than the EMEP recommendations leads to significantly improved simulation of background SO2, NO2 and O3 concentrations when compared to the Airbase station measurements.

  11. Thermodynamics of Charged AdS Black Holes in Extended Phases Space via M2-branes Background

    CERN Document Server

    Chabab, M; Masmar, K

    2015-01-01

    Motivated by a recent work on asymptotically Ad$S_4$ black holes in M-theory, we investigate both thermodynamics and thermodynamical geometry of Raissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in $AdS_{4}\\times S^{7}$, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner and Quevedo metrics for M2-branes geometry to study the stability of such black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results obtained by the phase transition program via the heat capacities in different ensembles either when the number of the M2 branes or the charge are held fixed. Also, we note that all results derived in [1] are recovered in the ...

  12. On thermodynamics of charged AdS black holes in extended phases space via M2-branes background

    Science.gov (United States)

    Chabab, M.; El Moumni, H.; Masmar, K.

    2016-06-01

    Motivated by a recent work on asymptotically AdS_4 black holes in M-theory, we investigate both thermodynamics and the thermodynamical geometry of Reissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in AdS4× S7, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner, and Quevedo metrics for M2-branes geometry to study the stability of such a black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results to those obtained by the phase transition diagram via the heat capacities in different ensembles either when the number of the M2 branes or the charge is held fixed. Also, we note that all results derived in Belhaj et al. (Eur Phys J C 76(2):73, 2016) are recovered in the limit of the vanishing charge.

  13. On thermodynamics of charged AdS black holes in extended phases space via M2-branes background

    Energy Technology Data Exchange (ETDEWEB)

    Chabab, M.; Masmar, K. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); El Moumni, H. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); Universite Ibn Zohr, Departement de Physique, Faculte des Sciences, Agadir (Morocco)

    2016-06-15

    Motivated by a recent work on asymptotically AdS{sub 4} black holes in M-theory, we investigate both thermodynamics and the thermodynamical geometry of Reissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in AdS{sub 4} x S{sup 7}, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner, and Quevedo metrics for M2-branes geometry to study the stability of such a black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results to those obtained by the phase transition diagram via the heat capacities in different ensembles either when the number of the M2 branes or the charge is held fixed. Also, we note that all results derived in Belhaj et al. (Eur Phys J C 76(2):73, 2016) are recovered in the limit of the vanishing charge. (orig.)

  14. 电压频率偏移条件下新型锁相环在三相电压型PWM整流器中的应用%The application of the novel phase-locked loop in three-phase voltage source PWM rectifier under frequency offset of voltage

    Institute of Scientific and Technical Information of China (English)

    侯世英; 张诣

    2011-01-01

    Aiming at the problems that classic phase-locked loop (PLL) has low response speed and detection accuracy under frequency offset of network voltage conditions, a novel analog signal PLL based on coordinate transformation is proposed, and based on the PLL, the model of three-phase voltage source pulse width modulation (PWM) rectifier is built. The rectifier adopts the modulation method of space vector pulse width modulation(SVPWM). According to the circuit topology of the PWM rectifier, the framework of control strategy is given. Also the circuit topology and working principle of PLL are analyzed. Finally, a simulation is done through the Matlab. Simulation results show that the PLL can track the network frequency so well that it can realize phase locking. And the novel PLL can also achieve phase locking under the condition of frequency drift of three-phase network voltage.%为了解决在电网电压出现频率偏移时,传统锁相环响应速度慢、锁相精度差的问题,提出一种基于坐标变换理论的新型模拟信号锁相环,并建立了基于模拟信号锁相环的三相电压型PWM整流器模型.该整流器采用空间矢量脉宽调制(Space Vector Pulse Width Modulation,SVPWM).在对所提PwM整流器的基本拓扑进行分析的基础上,给出了控制策略框图,并分析了新型锁相环的电路结构和工作原理.通过Matlab对所建模型进行了仿真.仿真结果表明:模拟信号锁相环能够快速跟踪系统频率的变化,实现锁相功能.同时,在三相电网电压频率出现小范围漂移情况下,新型锁相环也能够准确锁相.

  15. Offset rejection for PLL based synchronization in grid-connected converters

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Teodorescu, Remus; Agelidis, Vassilios

    2008-01-01

    in the measured grid voltage. This voltage offset is typically introduced by the measurements and data conversion processes and causes errors for the estimated parameters of the grid voltage. Accordingly, this paper presents an offset rejection method for grid-connected converters based on a phase-lockedloop (PLL......Grid-connected converters rely on fast and accurate detection of the phase angle, amplitude and frequency of the utility voltage to guarantee the correct generation of the reference signals. An important issue associated with accurate grid voltage monitoring is the presence of an offset...

  16. Influence of Frequency Offset on Modified EGC Diversity Receiver

    Directory of Open Access Journals (Sweden)

    B. Z. Nikolić

    2013-11-01

    Full Text Available In this paper a performance analysis of a modified M-ary phase-shift-keying (MPSK signal diversity receiver with a predetection equal gain combiner (EGC will be presented. The modification is in introducing a structure that performs the estimation with remodulation (ER. The EGC combining is realized by using a constant modulus algorithm (CMA. The influence of carrier frequency offset, length of ER structure and other parameters of the receiver will be examined.

  17. Offset and linear spread geometry in the MASW method

    International Nuclear Information System (INIS)

    This paper evaluates the effect of near offset and geophone configuration on dispersion image for linear spreads in the multichannel analysis of surface waves (MASW) method. In order to determine the effect of near offset, MASW records were collected for a variety of offsets and the corresponding calculated dispersion images were compared for a fixed layout. To reveal the spectral resolution of dispersion images, MASW records were collected using nine different types of linear spread configuration, then dispersion images for each MASW record were calculated using the phase velocity analysis technique and were compared to the present preferable linear spread type for a MASW survey. The results show that at least one pair of near offset shots is required for distinguishing the fundamental mode from the higher modes without ambiguity, and for picking a dispersion curve in a wide frequency range. The first shot distance should not be longer than four times the geophone interval, and the second shot distance should be equal to or longer than the one-third spread length, depending on the power of the seismic source. A better dispersion image resolution and dispersion curve in the wide frequency range can be obtained by using the SL-type geophone configuration. Besides this, in a survey in which higher frequencies are more important, the SII-type configuration may be preferable. With the SII-type spread configuration, the fundamental mode can easily be distinguished from the higher modes

  18. Rift offsets, Gulf of Suez, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Patton, T.L.; Nelson, R.A.

    1988-01-01

    Structure and stratigraphic mapping in the northern half of the Gulf of Suex (GOS) documents two en echelon, rift-parallel (Clysmic trend) rift segments. The segments are right stepping and share a zone of overlap, which extends southward from the southern border of the Wadi Araba structure on the western shore of the gulf to the north end of the Abu Durba block on the east side of the gulf. The spatial relationship of the two segments defines the central GOS rift offset, and the structural depression linking the segments in the area of overlap forms a rift-offset zone. Another potential rift offset, though less well constrained, also with a north-south trend may be present south of Gebel Zeit. This rift and the central GOS rift offset provide a model for the opening of the GOS in which north-south rift-offset zones link Clysmic-trending rift segments, imparting a regional zig-zag pattern to the initial rift configuration. Recognition of offset zones and their associated fault fabrics is essential for effective exploration of rift basins. For example, the alignment of producing fields and elongation directions of individual fields in the central GOS offset are anomalous relative to those of other producing trends in the Gulf.

  19. Rift offsets, Gulf of Suez, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Patton, T.L.; Nelson, R.A.

    1988-02-01

    Structure and stratigraphic mapping in the northern half of the Gulf of Suez (GOS) documents two en echelon, rift-parallel (Clysmic trend) rift segments. The segments are right stepping and share a zone of overlap, which extends southward from the southern border of the Wadi Araba structure on the western shore of the gulf to the north end of the Abu Durba block on the east side of the gulf. The spatial relationship of the two segments defines the central GOS rift offset, and the structural depression linking the segments in the area of overlap forms a rift-offset zone. Another potential rift offset, though less well constrained, also with a north-south trend may be present south of Gebel Zeit. This rift and the central GOS rift offset provide a model for the opening of the GOS in which north-south rift-offset zones link Clysmic-trending rift segments, imparting a regional zig-zag pattern to the initial rift configuration. Recognition of offset zones and their associated fault fabrics is essential for effective exploration of rift basins. For example, the alignment of producing fields and elongation directions of individual fields in the central GOS offset are anomalous relative to those of other producing trends in the Gulf.

  20. Great apes and biodiversity offset projects in Africa: the case for national offset strategies.

    Directory of Open Access Journals (Sweden)

    Rebecca Kormos

    Full Text Available The development and private sectors are increasingly considering "biodiversity offsets" as a strategy to compensate for their negative impacts on biodiversity, including impacts on great apes and their habitats in Africa. In the absence of national offset policies in sub-Saharan Africa, offset design and implementation are guided by company internal standards, lending bank standards or international best practice principles. We examine four projects in Africa that are seeking to compensate for their negative impacts on great ape populations. Our assessment of these projects reveals that not all apply or implement best practices, and that there is little standardization in the methods used to measure losses and gains in species numbers. Even if they were to follow currently accepted best-practice principles, we find that these actions may still fail to contribute to conservation objectives over the long term. We advocate for an alternative approach in which biodiversity offset and compensation projects are designed and implemented as part of a National Offset Strategy that (1 takes into account the cumulative impacts of development in individual countries, (2 identifies priority offset sites, (3 promotes aggregated offsets, and (4 integrates biodiversity offset and compensation projects with national biodiversity conservation objectives. We also propose supplementary principles necessary for biodiversity offsets to contribute to great ape conservation in Africa. Caution should still be exercised, however, with regard to offsets until further field-based evidence of their effectiveness is available.

  1. Great apes and biodiversity offset projects in Africa: the case for national offset strategies.

    Science.gov (United States)

    Kormos, Rebecca; Kormos, Cyril F; Humle, Tatyana; Lanjouw, Annette; Rainer, Helga; Victurine, Ray; Mittermeier, Russell A; Diallo, Mamadou S; Rylands, Anthony B; Williamson, Elizabeth A

    2014-01-01

    The development and private sectors are increasingly considering "biodiversity offsets" as a strategy to compensate for their negative impacts on biodiversity, including impacts on great apes and their habitats in Africa. In the absence of national offset policies in sub-Saharan Africa, offset design and implementation are guided by company internal standards, lending bank standards or international best practice principles. We examine four projects in Africa that are seeking to compensate for their negative impacts on great ape populations. Our assessment of these projects reveals that not all apply or implement best practices, and that there is little standardization in the methods used to measure losses and gains in species numbers. Even if they were to follow currently accepted best-practice principles, we find that these actions may still fail to contribute to conservation objectives over the long term. We advocate for an alternative approach in which biodiversity offset and compensation projects are designed and implemented as part of a National Offset Strategy that (1) takes into account the cumulative impacts of development in individual countries, (2) identifies priority offset sites, (3) promotes aggregated offsets, and (4) integrates biodiversity offset and compensation projects with national biodiversity conservation objectives. We also propose supplementary principles necessary for biodiversity offsets to contribute to great ape conservation in Africa. Caution should still be exercised, however, with regard to offsets until further field-based evidence of their effectiveness is available. PMID:25372894

  2. Great apes and biodiversity offset projects in Africa: the case for national offset strategies.

    Science.gov (United States)

    Kormos, Rebecca; Kormos, Cyril F; Humle, Tatyana; Lanjouw, Annette; Rainer, Helga; Victurine, Ray; Mittermeier, Russell A; Diallo, Mamadou S; Rylands, Anthony B; Williamson, Elizabeth A

    2014-01-01

    The development and private sectors are increasingly considering "biodiversity offsets" as a strategy to compensate for their negative impacts on biodiversity, including impacts on great apes and their habitats in Africa. In the absence of national offset policies in sub-Saharan Africa, offset design and implementation are guided by company internal standards, lending bank standards or international best practice principles. We examine four projects in Africa that are seeking to compensate for their negative impacts on great ape populations. Our assessment of these projects reveals that not all apply or implement best practices, and that there is little standardization in the methods used to measure losses and gains in species numbers. Even if they were to follow currently accepted best-practice principles, we find that these actions may still fail to contribute to conservation objectives over the long term. We advocate for an alternative approach in which biodiversity offset and compensation projects are designed and implemented as part of a National Offset Strategy that (1) takes into account the cumulative impacts of development in individual countries, (2) identifies priority offset sites, (3) promotes aggregated offsets, and (4) integrates biodiversity offset and compensation projects with national biodiversity conservation objectives. We also propose supplementary principles necessary for biodiversity offsets to contribute to great ape conservation in Africa. Caution should still be exercised, however, with regard to offsets until further field-based evidence of their effectiveness is available.

  3. 13 CFR 120.1722 - SBA's offset rights.

    Science.gov (United States)

    2010-01-01

    ... offset rights. SBA shall have the right to offset any amount owed by Lender to SBA, including, without limitation, an offset against CSA's obligation to pay Lender pursuant to any Section 504 First Mortgage...

  4. 34 CFR 31.11 - Offset process.

    Science.gov (United States)

    2010-07-01

    ... provisions of 4 CFR 102.4. (e) The Secretary effects an offset under this part against payments owing to an... the provisions of 5 CFR 550.1108. (Authority: 5 U.S.C. 5514; 31 U.S.C. 3716) ... 34 Education 1 2010-07-01 2010-07-01 false Offset process. 31.11 Section 31.11 Education Office...

  5. Ecological evaluation of proposed discharge of dredged material from Oakland Harbor into ocean waters (Phase 3 of 38-Foot Project). Volume 1, Background and appendixes A through H

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.A.; Word, J.Q.; Pinza, M.R.; Mayhew, H.L.; Barrows, E.S.; Kohn, N.P.; Lefkovitz, L.F. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1992-01-01

    At the request of the US Army Corps of Engineering (USACE), environmental studies were conducted by Battelle/Marine Sciences Laboratory (MSL) to evaluate the suitability of sediments from Oakland Inner Harbor for dredging and ocean disposal. During the Phase 3 38-Foot Project, sediment cores were collected from mudline to {minus}39 ft mean lower low water at various locations in Oakland Inner Harbor channel and allocated to six composite samples. These composites were evaluated through physical/chemical analyses, acute toxicity to sensitive marine organisms, and bioaccumulation potential. Sediment samples from individual locations were tested for physical/chemical parameters only. The results of toxicological and bioaccumulation testing may be used by USACE to determine the amount of potential dredged material from Oakland Inner Harbor channel acceptable for open-water disposal as defined by the Draft Implementation Manual (EPA/USACE 1990) and consistent with the Water Resources Development Act of 1986 (Public Law 99-662). This is Volume 1 of a two-volume data report that presents the data gathered during the Oakland Harbor Phase 3 38-Foot Project, conducted in the Fall of 1990. This data report does not include interpretation or statistical analysis of the 38-Foot data. Volume 1 includes the project background as well as a full presentation of data and results in Appendixes A through H. Volume 2 contains the remaining data in Appendixes I through L.

  6. Great Apes and Biodiversity Offset Projects in Africa: The Case for National Offset Strategies

    OpenAIRE

    Rebecca Kormos; Kormos, Cyril F.; Tatyana Humle; Annette Lanjouw; Helga Rainer; Ray Victurine; Mittermeier, Russell A; Diallo, Mamadou S.; Rylands, Anthony B.; Williamson, Elizabeth A.

    2014-01-01

    The development and private sectors are increasingly considering "biodiversity offsets" as a strategy to compensate for their negative impacts on biodiversity, including impacts on great apes and their habitats in Africa. In the absence of national offset policies in sub-Saharan Africa, offset design and implementation are guided by company internal standards, lending bank standards or international best practice principles. We examine four projects in Africa that are seeking to compensate fo...

  7. Cumulative-Phase-Alteration of Galactic-Light Passing Through the Cosmic-Microwave-Background: A New Mechanism for Some Observed Spectral-Shifts

    Directory of Open Access Journals (Sweden)

    Tank H. K.

    2012-07-01

    Full Text Available Currently, whole of the measured “cosmological-red-shift ” is interpreted as due to the “metric-expansion-of-space”; so for the required “closer -density” of the universe, we need twenty times more mass-energy than the visible baryonic-matter contained in the universe. This paper proposes a new mechanism, which can account for good per- centage of the red-shift in the extra-galactic-light, greatly reducing the requirement of dark matter-energy. Also, this mechanism can cause a new kin d of blue-shift reported here, and their observational evidences. These spectral-s hifts are proposed to result due to cumulative phase-alteration of extra-galactic-light b ecause of vector-addition of: (i electric-field of extra-galactic-light and (ii that of the cosmic-microwave-background (CMB. Since the center-frequency of CMB is much lower than extra-galactic-light, the cumulative-phase-alteration results in red -shift, observed as an additional contribu- tor to the measured “cosmological red-shift”; and since the center-frequency of CMB is higher than the radio-frequency-signals used to measure velocity of space-probes like: Pioneer-10, Pioneer-11, Galileo and Ulysses, the cum ulative-phase-alteration re- sulted in blue-shift, leading to the interpretation of deceleration of these space-probes. While the galactic-light experiences the red-shift, and th e ranging-signals of the space- probes experience blue -shift, they are comparable in magnitude, providing a supportive- evidence for the new mechanism proposed here. More confirmative-experiments for this new mechanism are also proposed.

  8. Great Apes and Biodiversity Offset Projects in Africa: The Case for National Offset Strategies

    Science.gov (United States)

    Kormos, Rebecca; Kormos, Cyril F.; Humle, Tatyana; Lanjouw, Annette; Rainer, Helga; Victurine, Ray; Mittermeier, Russell A.; Diallo, Mamadou S.; Rylands, Anthony B.; Williamson, Elizabeth A.

    2014-01-01

    The development and private sectors are increasingly considering “biodiversity offsets” as a strategy to compensate for their negative impacts on biodiversity, including impacts on great apes and their habitats in Africa. In the absence of national offset policies in sub-Saharan Africa, offset design and implementation are guided by company internal standards, lending bank standards or international best practice principles. We examine four projects in Africa that are seeking to compensate for their negative impacts on great ape populations. Our assessment of these projects reveals that not all apply or implement best practices, and that there is little standardization in the methods used to measure losses and gains in species numbers. Even if they were to follow currently accepted best-practice principles, we find that these actions may still fail to contribute to conservation objectives over the long term. We advocate for an alternative approach in which biodiversity offset and compensation projects are designed and implemented as part of a National Offset Strategy that (1) takes into account the cumulative impacts of development in individual countries, (2) identifies priority offset sites, (3) promotes aggregated offsets, and (4) integrates biodiversity offset and compensation projects with national biodiversity conservation objectives. We also propose supplementary principles necessary for biodiversity offsets to contribute to great ape conservation in Africa. Caution should still be exercised, however, with regard to offsets until further field-based evidence of their effectiveness is available. PMID:25372894

  9. Rounded leaf end effect of multileaf collimator on penumbra width and radiation field offset: an analytical and numerical study

    Directory of Open Access Journals (Sweden)

    Zhou Dong

    2015-09-01

    Full Text Available Background. Penumbra characteristics play a significant role in dose delivery accuracy for radiation therapy. For treatment planning, penumbra width and radiation field offset strongly influence target dose conformity and organ at risk sparing.

  10. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia;

    2016-01-01

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  11. 7 CFR 3.46 - Offset against tax refunds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Offset against tax refunds. 3.46 Section 3.46 Agriculture Office of the Secretary of Agriculture DEBT MANAGEMENT Administrative Offset § 3.46 Offset against tax refunds. USDA will take action to effect administrative offset against tax refunds due to...

  12. Performance Analysis of OFDM with Frequency Offset and Correction Model

    Institute of Scientific and Technical Information of China (English)

    QIN Sheng-ping; YIN Chang-chuan; LUO Tao; YUE Guang-xin

    2003-01-01

    The performance of OFDM with frequency offset is analyzed and simulated in this paper. It is concluded that the SIR is very large and the BER of OFDM system with frequency offset is strongly affected. A BER calculating method is introduced and simulated. Assumed that the frequency offset is known, frequency offset correction model is discussed.

  13. Conservation planning for offsetting the impacts of development: a case study of biodiversity and renewable energy in the Mojave Desert

    Science.gov (United States)

    Kreitler, Jason R.; Schloss, Carrie A.; Soong, Oliver; Lee Hannah,; Davis, Frank W.

    2015-01-01

    Balancing society’s competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species’ habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide

  14. Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert.

    Directory of Open Access Journals (Sweden)

    Jason Kreitler

    Full Text Available Balancing society's competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species' habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and

  15. Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert.

    Science.gov (United States)

    Kreitler, Jason; Schloss, Carrie A; Soong, Oliver; Hannah, Lee; Davis, Frank W

    2015-01-01

    Balancing society's competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species' habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide

  16. Retrodirective Antenna Array Using High Frequency Offset

    Directory of Open Access Journals (Sweden)

    P. Sindler

    2012-12-01

    Full Text Available The paper deals with the design of a simple retrodirective antenna array exhibiting by high frequency offset between received and transmitted wave. Analysis of the beam pointing error using antenna array model developed in MATLAB is described. The frequencies of transmitted wave and received wave are chosen on the basis of this analysis. Then a suitable structure for further design is determined and particular blocks of complete retrodirective antenna array are briefly described and their measured parameters are presented. Relatively high frequency offset between received and transmitted wave makes it possible to use frequency filters for received and transmitted signal separation which led to significant reduction of the circuit complexity.

  17. Can Exercise Offset Alcohol's Damaging Effects?

    Science.gov (United States)

    ... Videos & Tools Español You Are Here: Home → Latest Health News → Article URL of this page: https://medlineplus.gov/news/fullstory_160853.html Can Exercise Offset Alcohol's Damaging Effects? Even gardening, brisk walking may reduce your risk ...

  18. 20 CFR 627.708 - Offset process.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Offset process. 627.708 Section 627.708 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR GENERAL PROVISIONS GOVERNING... process. (a) In accordance with section 164(d) of the Act, the primary sanction for misexpenditure of...

  19. Effects of Carrier Frequency Offset, Timing Offset, and Channel Spread Factor on the Performance of Hexagonal Multicarrier Modulation Systems

    Directory of Open Access Journals (Sweden)

    Xu Kui

    2009-01-01

    Full Text Available Abstract Hexagonal multicarrier modulation (HMM system is the technique of choice to overcome the impact of time-frequency dispersive transmission channel. This paper examines the effects of insufficient synchronization (carrier frequency offset, timing offset on the amplitude and phase of the demodulated symbol by using a projection receiver in hexagonal multicarrier modulation systems. Furthermore, effects of CFO, TO, and channel spread factor on the performance of signal-to-interference-plus-noise ratio (SINR in hexagonal multicarrier modulation systems are further discussed. The exact SINR expression versus insufficient synchronization and channel spread factor is derived. Theoretical analysis shows that similar degradation on symbol amplitude and phase caused by insufficient synchronization is incurred as in traditional cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM transmission. Our theoretical analysis is confirmed by numerical simulations in a doubly dispersive (DD channel with exponential delay power profile and U-shape Doppler power spectrum, showing that HMM systems outperform traditional CP-OFDM systems with respect to SINR against ISI/ICI caused by insufficient synchronization and doubly dispersive channel.

  20. Effects of Carrier Frequency Offset, Timing Offset, and Channel Spread Factor on the Performance of Hexagonal Multicarrier Modulation Systems

    Directory of Open Access Journals (Sweden)

    Kui Xu

    2009-01-01

    Full Text Available Hexagonal multicarrier modulation (HMM system is the technique of choice to overcome the impact of time-frequency dispersive transmission channel. This paper examines the effects of insufficient synchronization (carrier frequency offset, timing offset on the amplitude and phase of the demodulated symbol by using a projection receiver in hexagonal multicarrier modulation systems. Furthermore, effects of CFO, TO, and channel spread factor on the performance of signal-to-interference-plus-noise ratio (SINR in hexagonal multicarrier modulation systems are further discussed. The exact SINR expression versus insufficient synchronization and channel spread factor is derived. Theoretical analysis shows that similar degradation on symbol amplitude and phase caused by insufficient synchronization is incurred as in traditional cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM transmission. Our theoretical analysis is confirmed by numerical simulations in a doubly dispersive (DD channel with exponential delay power profile and U-shape Doppler power spectrum, showing that HMM systems outperform traditional CP-OFDM systems with respect to SINR against ISI/ICI caused by insufficient synchronization and doubly dispersive channel.

  1. Carrier-based Modulation and Capacitor Voltage Balance Control Method With Voltage Offset Injection of Single Phase Cascaded H-bridge Rectifiers%基于电压补偿分量注入的单相级联H桥整流器载波调制与电容电压平衡方法

    Institute of Scientific and Technical Information of China (English)

    王顺亮; 宋文胜; 冯晓云

    2015-01-01

    无工频牵引变压器技术是实现高速列车轻量化的手段之一。该文首先分析了无工频变压器电力牵引传动系统前端级联 H 桥整流器的工作原理,以及开关状态和网侧电流对直流侧电容充放电的影响。针对级联 H 桥整流器电容电压平衡问题,为了实现负载严重不对称情况下直流侧电容电压快速平衡的控制目标,以传统的载波移相脉宽调制方法为基础,提出了一种基于电压补偿分量注入的载波移相脉宽调制算法。考虑负载不平衡度很大的恶劣情况,对该算法的电压补偿分量进行设计与定量计算,并针对该算法多个 H 桥级联拓扑的应用进行了理论扩展。计算机仿真和半实物实验都验证了该算法的有效性和正确性。%Transformerless technology is one of the realization of high-speed railway train lightweight. The operation principle of the front-end cascaded H-bridge rectifiers is analyzed, as well as switching states and the line current’s influence on DC-link capacitors’ charging and discharging. A carrier phase-shift PWM with voltage offset injection (CPSPWM-VOI) algorithm based on the conventional CPSPWM is proposed to balance DC-link capacitors’ voltages quickly in severe terrible application condition. Voltage offset component is designed and calculated quantitatively in a bad load imbalance degree. And the proposed algorithm is extended in multiple cascaded H-bridge rectifiers. The effectiveness and correctness of the CPSPWM-VOI algorithm are verified by the computer simulation and hardware-in-the-loop experiments.

  2. The isotropic radio background revisited

    CERN Document Server

    Fornengo, Nicolao; Regis, Marco; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emi...

  3. Surface reconstruction by offset surface filtering

    Institute of Scientific and Technical Information of China (English)

    DONG Chen-shi; WANG Guo-zhao

    2005-01-01

    The problem of computing a piecewise linear approximation to a surface from its sample has been a focus of research in geometry modeling and graphics due to its widespread applications in computer aided design. In this paper, we give a new algorithm, to be called offset surface filtering (OSF) algorithm, which computes a piecewise-linear approximation of a smooth surface from a finite set of cloud points. The algorithm has two main stages. First, the surface normal on every point is estimated by the least squares best fitting plane method. Second, we construct a restricted Delaunay triangulation, which is a tubular neighborhood of the surface defined by two offset surfaces. The algorithm is simple and robust. We describe an implementation of it and show example outputs.

  4. Offset wrap rib antenna concept development

    Science.gov (United States)

    Woods, A. A., Jr.; Garcia, N. F.

    1982-01-01

    The demonstration of 50 to 150 m, STS compatible, offset antenna technology readiness is reported. Fabrication of a ground and flight testable partial 55 m reflector section and feed support structure is discussed. Reduction to practice through ground test verification is presently contained in the program. Key objectives for the program include the design of a compatible feed support structure and the fabrication and testing of critical components.

  5. Voluntary biodiversity offset strategies in Madagascar

    OpenAIRE

    Bidaud, C.; Hrabranski, M.; Méral, Philippe

    2015-01-01

    In this article we examine the institutional strategies and methods of biodiversity offset calculation employed by two mining companies in Madagascar. Much like the REDD+ mechanisms, these environmental projects are based on estimations of the past and predictions of the future, and require validation by international experts. They incorporate a set of standard indicators adapted to the affected habitats, and specially developed units of measurement to demonstrate ecological equivalence. The ...

  6. Update on markets for forestry offsets

    International Nuclear Information System (INIS)

    This guide is an update of the book 'Guidebook to Markets and Commercialization of CDM forestry projects'. The document provides information on the development of CMD methodologies, projects registered and markets since the publication of the first version. In addition it introduces the emerging non-Kyoto markets, it presents a classification of the existing developments, it describes each market including the buyer's preferences and it discusses the use of standards and quality criteria and transaction costs. We focus on markets for offsets from developing countries, rather than domestic offsets in developed countries. Section 1 is an introduction to the topic and an overview of the most recent developments. Sections 2 and 3 look at recent experiences and market developments for CDM reforestation projects. These sections are meant to be an update of the above mentioned guidebook and thus refrain from an exhaustive description. Section 4 assesses non-Kyoto markets for carbon offsets from forestry projects. It includes a description of the various market schemes and types of buyers. The section attempts to provide the project developer with useful information for developing a project following buyer' requirements. Finally, section 5 puts the assessment of opportunities for forestry in the broader context of the larger carbon markets. The report then concludes with a comparison of advantages and disadvantages of the CDM and non-Kyoto schemes from the project developer's point of view

  7. 40 CFR 13.20 - Administrative offset of general debts.

    Science.gov (United States)

    2010-07-01

    ... provides for EPA's collection of debts by administrative offset under section 5 of the Debt Collection Act...) Failure to take the offset would substantially prejudice EPA's ability to collect the debt; and (ii)...

  8. Net Present Biodiversity Value and the Design of Biodiversity Offsets

    OpenAIRE

    Overton, Jacob McC.; Stephens, R. T. Theo; Ferrier, Simon

    2012-01-01

    There is an urgent need to develop sound theory and practice for biodiversity offsets to provide a better basis for offset multipliers, to improve accounting for time delays in offset repayments, and to develop a common framework for evaluating in-kind and out-of-kind offsets. Here, we apply concepts and measures from systematic conservation planning and financial accounting to provide a basis for determining equity across type (of biodiversity), space, and time. We introduce net present biod...

  9. 47 CFR 1.1951 - Offset against tax refunds.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Offset against tax refunds. 1.1951 Section 1... Claims Owed the United States Cooperation with the Internal Revenue Service § 1.1951 Offset against tax refunds. The Commission will take action to effect administrative offset against tax refunds due...

  10. 5 CFR 179.211 - Notice of salary offset.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Notice of salary offset. 179.211 Section 179.211 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CLAIMS COLLECTION STANDARDS Salary Offset § 179.211 Notice of salary offset. (a) Upon receipt of...

  11. 5 CFR 179.212 - Procedures for salary offset.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Procedures for salary offset. 179.212 Section 179.212 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CLAIMS COLLECTION STANDARDS Salary Offset § 179.212 Procedures for salary offset. (a) The Director or his or...

  12. Structure of three-dimensional turbulent offset jets with small offset distances

    Science.gov (United States)

    Agelin-Chaab, Martin; Tachie, Mark

    2009-11-01

    An offset jet is a jet that discharges into a medium above a wall which is offset by a certain distance. The ``Coanda effect'' forces the offset jet to deflect towards the wall and eventually attaches itself to the wall. The only detailed study of three-dimensional offset jets (3DOJs) did not report the flow field in the region from the jet exit to the point where the jet attaches itself to the wall. In this region flow reversal is expected. Velocity measurements of 3DOJs were conducted using particle image velocimetry. The 3DOJs have different jet exit offset distances (h) normalized by the jet exit diameter (d) of h/d = 0.5 to 4. The Reynolds numbers based on the jet exit velocities and jet exit diameters were 5000, 10000 and 20000. The detailed flow fields of the 3DOJs were examined in terms of mean velocities, and one-point turbulence statistics. In view of the wide range of length and temporal scales that are present in turbulent flows, multi-point turbulence statistics such as two-point velocity correlations and proper orthogonal decomposition are used to document the salient features of 3DOJs.

  13. Influence of frequency offset on the reception of OFDM/QPSK signal using MBDD algorithm

    Directory of Open Access Journals (Sweden)

    N. Milošević

    2011-11-01

    Full Text Available In this paper we present the basic characteristics of Orthogonal Frequency Division Multiplex (OFDM systems with quadrature phase shift keying (QPSK modulation and multi-bit differential detection (MBDD. In the simulation environment designed for this purpose, we analyze the effects of frequency offset on the performances of OFDM digital communications. We also analyze the influence of OFDM system parameters on system performances for various values of frequency offset, number of bits for multi-bit detection and the number of subcarriers. We have shown the advantages and disadvantages of using MBDD in the OFDM systems.

  14. Interior micro-CT with an offset detector

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Kriti Sen [Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Gong, Hao [VT-WFU School of Biomedical Engingeering and Sciences, Virginia Tech, Blacksburg, Virginia 24061 (United States); Ghasemalizadeh, Omid [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Yu, Hengyong [VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina 27157 (United States); Wang, Ge [Biomedical Imaging Center/Cluster CBIS/BME, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Cao, Guohua, E-mail: ghcao@vt.edu [VT-WFU School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2014-06-15

    Purpose: The size of field-of-view (FOV) of a microcomputed tomography (CT) system can be increased by offsetting the detector. The increased FOV is beneficial in many applications. All prior investigations, however, have been focused to the case in which the increased FOV after offset-detector acquisition can cover the transaxial extent of an object fully. Here, the authors studied a new problem where the FOV of a micro-CT system, although increased after offset-detector acquisition, still covers an interior region-of-interest (ROI) within the object. Methods: An interior-ROI-oriented micro-CT scan with an offset detector poses a difficult reconstruction problem, which is caused by both detector offset and projection truncation. Using the projection completion techniques, the authors first extended three previous reconstruction methods from offset-detector micro-CT to offset-detector interior micro-CT. The authors then proposed a novel method which combines two of the extended methods using a frequency split technique. The authors tested the four methods with phantom simulations at 9.4%, 18.8%, 28.2%, and 37.6% detector offset. The authors also applied these methods to physical phantom datasets acquired at the same amounts of detector offset from a customized micro-CT system. Results: When the detector offset was small, all reconstruction methods showed good image quality. At large detector offset, the three extended methods gave either visible shading artifacts or high deviation of pixel value, while the authors’ proposed method demonstrated no visible artifacts and minimal deviation of pixel value in both the numerical simulations and physical experiments. Conclusions: For an interior micro-CT with an offset detector, the three extended reconstruction methods can perform well at a small detector offset but show strong artifacts at a large detector offset. When the detector offset is large, the authors’ proposed reconstruction method can outperform the three

  15. Focal surfaces of offset dual-reflector antennas

    Science.gov (United States)

    Sletten, C. J.; Shore, R. A.

    1982-01-01

    An analytical technique is described for finding the best focal surfaces for offset-fed dual-reflector antennas. A ray tracing procedure traces the loci of rays incident on the main reflector onto a plane or 'screen' situated perpendicular to a central ray of the antenna system. Given, then, by computer graphics, the best feed locations for azimuth and elevation plane patterns, an aperture diffraction method is used which can compute the sidelobe levels and beamwidths resulting from aperture phase errors on scanned or multibeam patterns. High-magnification Cassegrain or Gregorian antennas, with tilt angles optimised according to Japanese criteria, produce excellent radiation diagrams many beamwidths from the central, unaberrated pattern direction.

  16. Research on Stress Neutral Layer Offset in the Straightening Process

    Directory of Open Access Journals (Sweden)

    Hailian Gui

    2015-01-01

    Full Text Available The stress neutral layer offset is analyzed by theoretical and numerical calculation methods. In traditional straightening theory, the stress neutral layer was consistent with the geometric central layer. However, there is a phenomenon that the stress neutral layer has some offset with the geometric neutral layer. This offset is a very important factor for improving the precision of the straightening force. The formula of the stress neutral layer offset is obtained by a theoretical method and the change law is given by numerical calculation method. The neutral layer offset theory provides the theoretical basis for establishing the model of straightening force precisely.

  17. The azimuth-dependent offset-midpoint traveltime pyramid in 3D HTI media

    KAUST Repository

    Hao, Qi

    2013-09-22

    Analytical representation of offset-midpoint traveltime equation is very important for pre-stack Kirchhoff migration and velocity inversion in anisotropic media. For VTI media, the offset-midpoint traveltime resembles the shape of Cheop\\'s pyramid. In this study, we extend the offset-midpoint traveltime pyramid to the case of 3D HTI media. We employ the stationary phase method to derive the analytical representation of traveltime equation, and then use Shanks transformation to improve the accuracy of horizontal and vertical slownesses. The traveltime pyramid is derived in both the depth- and time-domain. Numerical examples indicate that the azimuthal characteristics of both the traveltime pyramid and the migration isochrones are very obvious in HTI media due to the effect of anisotropy.

  18. Emissions trading with offset markets and free quota allocations

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl, Knut Einar; Strand, Jon

    2012-07-01

    We study interactions between a 'policy bloc's' emissions quota market and an offset market where emissions offsets can be purchased from a non-policy 'fringe' of countries (such as for the CDM under the Kyoto Protocol). Policy-bloc firms are assumed to benefit from free quota allocations that are updated according to either past emissions or past outputs. We show that both overall abatement, and the allocation of given abatement between the policy bloc and the fringe, tend to be inefficient. When the policy-bloc quota market and offset markets are fully integrated (and firms buy offsets directly from the fringe), and all quotas and offsets must be traded at a single price, it is optimal for the policy bloc to either not constrain the offset market whatsoever, or to ban offsets completely. The former (latter) case occurs when free allocation of quotas is not too generous (very generous), and the offset market can profitably deliver large (only a small) quota amounts. Governments of policy countries would however instead prefer to buy offsets directly from the fringe at a price below the policy-bloc quota price. The offset price will then be below the marginal damage cost of emissions, and the quota price in the policy bloc above marginal damage cost. This solution is also inefficient as the policy bloc (acting as a monopsonist) purchases too few offsets from the fringe.(Author)

  19. First-principles study of Cu{sub 2}ZnSnS{sub 4} and the related band offsets for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Nagoya, A; Asahi, R [Toyota Central R and D Laboratories, Incorporated, Nagakute, Aichi 480-1192 (Japan); Kresse, G, E-mail: e1405@mosk.tytlabs.co.jp [Faculty of Physics, Universitaet Wien and Center for Computational Materials Science, Sensengasse 8/12, A-1090, Wien (Austria)

    2011-10-12

    First-principles calculations of the band offsets between Cu{sub 2}ZnSnS{sub 4} (CZTS) and XS (X = Cd, Zn) are performed. While the interface dipole contribution for the band offsets is calculated using the Perdew-Burke-Ernzerhof functional, the Heyd-Scuseria-Ernzerhof hybrid functional is employed to introduce the quasiparticle corrections to the band offsets. The calculated conduction band offset between CZTS and CdS is 0.2 eV, validating CdS for the buffer layer of the CZTS solar cell. The small conduction band offset stems from the band gap narrowing of CdS under the interface strain caused by the lattice misfit with CZTS. A large valence band offset over 0.9 eV between CZTS and ZnS indicates that precipitated ZnS is regarded as an inactive insulator phase in CZTS absorbers.

  20. IQ Imbalance Estimation Scheme in the Presence of DC Offset and Frequency Offset in the Frequency Domain

    Science.gov (United States)

    Inamori, Mamiko; Takayama, Shuzo; Sanada, Yukitoshi

    Direct conversion receivers in orthogonal frequency division multiplexing (OFDM) systems suffer from direct current (DC) offset, frequency offset, and IQ imbalance. We have proposed an IQ imbalance estimation scheme in the presence of DC offset and frequency offset, which uses preamble signals in the time domain. In this scheme, the DC offset is eliminated by a differential filter. However, the accuracy of IQ imbalance estimation is deteriorated when the frequency offset is small. To overcome this problem, a new IQ imbalance estimation scheme in the frequency domain with the differential filter has been proposed in this paper. The IQ imbalance is estimated with pilot subcarriers. Numerical results obtained through computer simulation show that estimation accuracy and bit error rate (BER) performance can be improved even if the frequency offset is small.

  1. OFFSET - RAY TRACING OPTICAL ANALYSIS OF OFFSET SOLAR COLLECTOR FOR SPACE STATION SOLAR DYNAMIC POWER SYSTEM

    Science.gov (United States)

    Jefferies, K.

    1994-01-01

    OFFSET is a ray tracing computer code for optical analysis of a solar collector. The code models the flux distributions within the receiver cavity produced by reflections from the solar collector. It was developed to model the offset solar collector of the solar dynamic electric power system being developed for Space Station Freedom. OFFSET has been used to improve the understanding of the collector-receiver interface and to guide the efforts of NASA contractors also researching the optical components of the power system. The collector for Space Station Freedom consists of 19 hexagonal panels each containing 24 triangular, reflective facets. Current research is geared toward optimizing flux distribution inside the receiver via changes in collector design and receiver orientation. OFFSET offers many options for experimenting with the design of the system. The offset parabolic collector model configuration is determined by an input file of facet corner coordinates. The user may choose other configurations by changing this file, but to simulate collectors that have other than 19 groups of 24 triangular facets would require modification of the FORTRAN code. Each of the roughly 500 facets in the assembled collector may be independently aimed to smooth out, or tailor, the flux distribution on the receiver's wall. OFFSET simulates the effects of design changes such as in receiver aperture location, tilt angle, and collector facet contour. Unique features of OFFSET include: 1) equations developed to pseudo-randomly select ray originating sources on the Sun which appear evenly distributed and include solar limb darkening; 2) Cone-optics technique used to add surface specular error to the ray originating sources to determine the apparent ray sources of the reflected sun; 3) choice of facet reflective surface contour -- spherical, ideal parabolic, or toroidal; 4) Gaussian distributions of radial and tangential components of surface slope error added to the surface normals at

  2. Joint frequency offset tracking and PAPR reduction algorithm in OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Lijun Ge; Yingxin Zhao; Hong Wu; Ning Xu; Yu'ang Jin; Wenqi Li

    2010-01-01

    This paper presents an algorithm that aims to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) communication systems while main-taining frequency tracking. The algorithm achieves PAPR reduction by applying the complex conjugates of the data symbol obtained from the frequency domain to cancel the phase of the data sym-bol. A likelihood estimator is used to obtain the sub-carrier phase error due to the residual carrier frequency offset (RCFO) using the same complex conjugates as a pilot signal. Furthermore, a joint time and frequency domain multicarrier phase locked loop (MPLL) is developed to compensate additional frequency offset. Simula-tion results show that this algorithm is capable of reducing PAPR without impacting the frequency tracking performance.

  3. Development by Design in Western Australia: Overcoming Offset Obstacles

    Directory of Open Access Journals (Sweden)

    James Fitzsimons

    2014-02-01

    Full Text Available Biodiversity offsets can be an important tool for maintaining or enhancing environmental values in situations where development is sought despite negative environmental impacts. There are now approximately 45 compensatory mitigation programs for biodiversity impacts worldwide, with another 27 programs in development. While offsets have great potential as a conservation tool, their establishment requires overcoming a number of conceptual and methodological hurdles. In Australia, new policy changes at the national and state (i.e., Western Australia level require that offsets follow a set of general principles: (1 Environmental offsets may not be appropriate for all projects and will only be considered after avoidance and mitigation options have been pursued; (2 Environmental offsets will be based on sound environmental information and knowledge; (3 Establishing goals for offsets requires an estimate of expected direct and indirect impacts; (4 Environmental offsets will be focused on longer term strategic outcomes; (5 Environmental offsets will be cost-effective, as well as relevant and proportionate to the significance of the environmental value being impacted. Here we focus on the challenges of determining and implementing offsets using a real world example from a voluntary offset process undertaken for Barrick Gold’s Kanowna Belle mine site in Western Australia to highlight those challenges and potential solutions.

  4. Biodiversity offsets and the challenge of achieving no net loss.

    Science.gov (United States)

    Gardner, Toby A; VON Hase, Amrei; Brownlie, Susie; Ekstrom, Jonathan M M; Pilgrim, John D; Savy, Conrad E; Stephens, R T Theo; Treweek, Jo; Ussher, Graham T; Ward, Gerri; Ten Kate, Kerry

    2013-12-01

    Businesses, governments, and financial institutions are increasingly adopting a policy of no net loss of biodiversity for development activities. The goal of no net loss is intended to help relieve tension between conservation and development by enabling economic gains to be achieved without concomitant biodiversity losses. biodiversity offsets represent a necessary component of a much broader mitigation strategy for achieving no net loss following prior application of avoidance, minimization, and remediation measures. However, doubts have been raised about the appropriate use of biodiversity offsets. We examined what no net loss means as a desirable conservation outcome and reviewed the conditions that determine whether, and under what circumstances, biodiversity offsets can help achieve such a goal. We propose a conceptual framework to substitute the often ad hoc approaches evident in many biodiversity offset initiatives. The relevance of biodiversity offsets to no net loss rests on 2 fundamental premises. First, offsets are rarely adequate for achieving no net loss of biodiversity alone. Second, some development effects may be too difficult or risky, or even impossible, to offset. To help to deliver no net loss through biodiversity offsets, biodiversity gains must be comparable to losses, be in addition to conservation gains that may have occurred in absence of the offset, and be lasting and protected from risk of failure. Adherence to these conditions requires consideration of the wider landscape context of development and offset activities, timing of offset delivery, measurement of biodiversity, accounting procedures and rule sets used to calculate biodiversity losses and gains and guide offset design, and approaches to managing risk. Adoption of this framework will strengthen the potential for offsets to provide an ecologically defensible mechanism that can help reconcile conservation and development. Balances de Biodiversidad y el Reto de No Obtener P

  5. Biodiversity offsets and the challenge of achieving no net loss.

    Science.gov (United States)

    Gardner, Toby A; VON Hase, Amrei; Brownlie, Susie; Ekstrom, Jonathan M M; Pilgrim, John D; Savy, Conrad E; Stephens, R T Theo; Treweek, Jo; Ussher, Graham T; Ward, Gerri; Ten Kate, Kerry

    2013-12-01

    Businesses, governments, and financial institutions are increasingly adopting a policy of no net loss of biodiversity for development activities. The goal of no net loss is intended to help relieve tension between conservation and development by enabling economic gains to be achieved without concomitant biodiversity losses. biodiversity offsets represent a necessary component of a much broader mitigation strategy for achieving no net loss following prior application of avoidance, minimization, and remediation measures. However, doubts have been raised about the appropriate use of biodiversity offsets. We examined what no net loss means as a desirable conservation outcome and reviewed the conditions that determine whether, and under what circumstances, biodiversity offsets can help achieve such a goal. We propose a conceptual framework to substitute the often ad hoc approaches evident in many biodiversity offset initiatives. The relevance of biodiversity offsets to no net loss rests on 2 fundamental premises. First, offsets are rarely adequate for achieving no net loss of biodiversity alone. Second, some development effects may be too difficult or risky, or even impossible, to offset. To help to deliver no net loss through biodiversity offsets, biodiversity gains must be comparable to losses, be in addition to conservation gains that may have occurred in absence of the offset, and be lasting and protected from risk of failure. Adherence to these conditions requires consideration of the wider landscape context of development and offset activities, timing of offset delivery, measurement of biodiversity, accounting procedures and rule sets used to calculate biodiversity losses and gains and guide offset design, and approaches to managing risk. Adoption of this framework will strengthen the potential for offsets to provide an ecologically defensible mechanism that can help reconcile conservation and development. Balances de Biodiversidad y el Reto de No Obtener P

  6. The phenological phases of flowering and pollen seasons of spring flowering tree taxa against a background of meteorological conditions in Kraków, Poland

    Directory of Open Access Journals (Sweden)

    Danuta Stępalska

    2016-06-01

    Full Text Available The aim of the study was to compare phenological observations of pollen seasons of selected early spring trees. Special attention was paid to meteorological conditions which favored or did not favor tree flowering and pollen release. For this reason, we used phenological observation, pollen counts, and meteorological data in five sites in the center of Kraków in the period 2009–2011. Phenological phases (5 of four tree species: Alnus glutinosa, Alnus incana, Corylus avellana, and Betula pendula, were analyzed. It was found that in case of A. glutinosa the pollen season often preceded the flowering period, while for A. incana those two phenomena were more correlated. As regards Corylus avellana, the beginning of the pollen season and phenological phases was simultaneous. However, pollen grains occurred in the air longer, even by a dozen or so days. The phenological phases and pollen seasons of Alnus and Corylus were dependent on meteorological conditions. To give the definition of the relationship between pollen concentration and weather conditions, Spearman rank correlation analysis was applied. High Alnus and Corylus pollen concentrations were found on sunny days with a maximum temperature over 10°C and no precipitation, and when the snow cover was gone. In case of Betula, the phenological phases of the full pollination period usually coincided with the periods of high pollen concentrations. However, Betula pollen sometimes appears earlier and stays in the air longer than the flowering period of local trees in the nearest vicinity. This situation indicates long-distance transport or secondary deposition.

  7. Fluorescence suppression using micro-scale spatially offset Raman spectroscopy.

    Science.gov (United States)

    Conti, Claudia; Botteon, Alessandra; Colombo, Chiara; Realini, Marco; Matousek, Pavel

    2016-09-21

    We present a new concept of fluorescence suppression in Raman microscopy based on micro-spatially offset Raman spectroscopy which is applicable to thin stratified turbid (diffusely scattering) matrices permitting the retrieval of the Raman signals of sublayers below intensely fluorescing turbid over-layers. The method is demonstrated to yield good quality Raman spectra with dramatically suppressed fluorescence backgrounds enabling the retrieval of Raman sublayer signals even in situations where conventional Raman microscopy spectra are fully overwhelmed by intense fluorescence. The concept performance was studied theoretically using Monte Carlo simulations indicating the potential of up to an order or two of magnitude suppression of overlayer fluorescence backgrounds relative to the Raman sublayer signals. The technique applicability was conceptually demonstrated on layered samples involving paints, polymers and stones yielding fluorescence suppression factors between 12 to above 430. The technique has potential applications in a number of analytical areas including cultural heritage, archaeology, polymers, food, pharmaceutical, biological, biomedical, forensics and catalytic sciences and quality control in manufacture.

  8. Effect of background color of tanks on growth and survival of juvenile Yellow Seahorse, Hippocampus kuda (Bleeker 1852), in the pelagic phase

    Digital Repository Service at National Institute of Oceanography (India)

    Pawar, H.B.; Sanaye, S.V.; Murugan, A.; Sreepada, R.A.; Tanu

    (Naas et al., 1996). While first-feeding Atlantic salmon alevins possess innate color preferences that can be altered by a single associative learning event (Clarke and Sutterlin, 1985), the presence of such innate color preferences has not been... and background color on feeding by Atlantic salmon alevins. Prog. Fish-Cult., 49:141-143. Clarke L.A. and A.M. Sutterlin, 1985. Associative learning, short-term memory, and color preference during first feeding by juvenile Atlantic salmon. Can. J. Zool., 63...

  9. OFFSET: Optical Fiber Folded Scintillating Extended Tracker

    International Nuclear Information System (INIS)

    The OFFSET collaboration aims at the development of a novel system for tracking charged particles, designed to achieve real-time imaging, large detection areas, and a high spatial resolution especially suitable for use in medical diagnostics. This paper presents the first prototype of this tracker, having a 20×20 cm2 sensitive area made by two crossed ribbons of 500μm square scintillating fibers. The track position information is extracted in real time using a reduced number of read-out channels to obtain very large detection area at moderate cost and complexity. The performance of the tracker was investigated using β sources, cosmic rays and a 62 MeV proton beam

  10. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.;

    2003-01-01

    revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... phase dependence in the background outside radiation belts was observed. The analysis yielded an average of 5 cps for the diffuse background, and 20 cps for the instrument background. The instrument background was found highly dependent on position, both for spectral shape and intensity. Diff use...... background was enhanced in the central area of a detector, and it decreased radially towards the edge, with a clear vignetting effect for both JEM-X units. The instrument background was weakest in the central area of a detector and showed a steep increase at the very edges of both JEM-X detectors, with...

  11. Net present biodiversity value and the design of biodiversity offsets.

    Science.gov (United States)

    Overton, Jacob McC; Stephens, R T Theo; Ferrier, Simon

    2013-02-01

    There is an urgent need to develop sound theory and practice for biodiversity offsets to provide a better basis for offset multipliers, to improve accounting for time delays in offset repayments, and to develop a common framework for evaluating in-kind and out-of-kind offsets. Here, we apply concepts and measures from systematic conservation planning and financial accounting to provide a basis for determining equity across type (of biodiversity), space, and time. We introduce net present biodiversity value (NPBV) as a theoretical and practical measure for defining the offset required to achieve no-net-loss. For evaluating equity in type and space we use measures of biodiversity value from systematic conservation planning. Time discount rates are used to address risk of non-repayment, and loss of utility. We illustrate these concepts and measures with two examples of biodiversity impact-offset transactions. Considerable further work is required to understand the characteristics of these approaches. PMID:22956430

  12. Orthogonal Frequency Division Multiplexing System with Frequency Offset Estimation

    Directory of Open Access Journals (Sweden)

    Meghashree D.Nimje

    2013-03-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM system, use a large number of parallel narrowband subcarriers instead of a single wide-band carrier to transport information. Orthogonal frequency division multiplexing is the modulation technique use in digital communication systems . Carrier frequency offset occurs due to Doppler effect or noise. Carrier frequency offsets (CFOs is the Offset between the transmitter and the receiver oscillators .CFO damages the orthogonality of the carries ,resulting in degradation of the systems performance. Carrier frequency offset estimation method is discussed in this paper. In this paper one complex training sequence use, which can effectively estimate carrier frequency offset in the time domain and frequency domain. Here fine and coarse frequency is estimated to improve the improve the system performance. This paper shows the estimation range for frequency offset can be improve to large extent..

  13. Rational offset approximation of rational Bézier curves

    Institute of Scientific and Technical Information of China (English)

    CHENG Min; WANG Guo-jin

    2006-01-01

    The problem of parametric speed approximation of a rational curve is raised in this paper. Offset curves are widely used in various applications. As for the reason that in most cases the offset curves do not preserve the same polynomial or rational polynomial representations, it arouses difficulty in applications. Thus approximation methods have been introduced to solve this problem. In this paper, it has been pointed out that the crux of offset curve approximation lies in the approximation of parametric speed. Based on the Jacobi polynomial approximation theory with endpoints interpolation, an algebraic rational approximation algorithm of offset curve, which preserves the direction of normal, is presented.

  14. Economic and ecological outcomes of flexible biodiversity offset systems.

    Science.gov (United States)

    Habib, Thomas J; Farr, Daniel R; Schneider, Richard R; Boutin, Stan

    2013-12-01

    The commonly expressed goal of biodiversity offsets is to achieve no net loss of specific biological features affected by development. However, strict equivalency requirements may complicate trading of offset credits, increase costs due to restricted offset placement options, and force offset activities to focus on features that may not represent regional conservation priorities. Using the oil sands industry of Alberta, Canada, as a case study, we evaluated the economic and ecological performance of alternative offset systems targeting either ecologically equivalent areas (vegetation types) or regional conservation priorities (caribou and the Dry Mixedwood natural subregion). Exchanging dissimilar biodiversity elements requires assessment via a generalized metric; we used an empirically derived index of biodiversity intactness to link offsets with losses incurred by development. We considered 2 offset activities: land protection, with costs estimated as the net present value of profits of petroleum and timber resources to be paid as compensation to resource tenure holders, and restoration of anthropogenic footprint, with costs estimated from existing restoration projects. We used the spatial optimization tool MARXAN to develop hypothetical offset networks that met either the equivalent-vegetation or conservation-priority targets. Networks that required offsetting equivalent vegetation cost 2-17 times more than priority-focused networks. This finding calls into question the prudence of equivalency-based systems, particularly in relatively undeveloped jurisdictions, where conservation focuses on limiting and directing future losses. Priority-focused offsets may offer benefits to industry and environmental stakeholders by allowing for lower-cost conservation of valued ecological features and may invite discussion on what land-use trade-offs are acceptable when trading biodiversity via offsets. Resultados Económicos y Ecológicos de Sistemas de Compensación de

  15. Economic and ecological outcomes of flexible biodiversity offset systems.

    Science.gov (United States)

    Habib, Thomas J; Farr, Daniel R; Schneider, Richard R; Boutin, Stan

    2013-12-01

    The commonly expressed goal of biodiversity offsets is to achieve no net loss of specific biological features affected by development. However, strict equivalency requirements may complicate trading of offset credits, increase costs due to restricted offset placement options, and force offset activities to focus on features that may not represent regional conservation priorities. Using the oil sands industry of Alberta, Canada, as a case study, we evaluated the economic and ecological performance of alternative offset systems targeting either ecologically equivalent areas (vegetation types) or regional conservation priorities (caribou and the Dry Mixedwood natural subregion). Exchanging dissimilar biodiversity elements requires assessment via a generalized metric; we used an empirically derived index of biodiversity intactness to link offsets with losses incurred by development. We considered 2 offset activities: land protection, with costs estimated as the net present value of profits of petroleum and timber resources to be paid as compensation to resource tenure holders, and restoration of anthropogenic footprint, with costs estimated from existing restoration projects. We used the spatial optimization tool MARXAN to develop hypothetical offset networks that met either the equivalent-vegetation or conservation-priority targets. Networks that required offsetting equivalent vegetation cost 2-17 times more than priority-focused networks. This finding calls into question the prudence of equivalency-based systems, particularly in relatively undeveloped jurisdictions, where conservation focuses on limiting and directing future losses. Priority-focused offsets may offer benefits to industry and environmental stakeholders by allowing for lower-cost conservation of valued ecological features and may invite discussion on what land-use trade-offs are acceptable when trading biodiversity via offsets. Resultados Económicos y Ecológicos de Sistemas de Compensación de

  16. Induced CMB quadrupole from pointing offsets

    Science.gov (United States)

    Moss, Adam; Scott, Douglas; Sigurdson, Kris

    2011-01-01

    Recent claims in the literature have suggested that the WMAP quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than the WMAP value. We discuss reasons why the WMAP data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between the pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here — the dipole signal lies close to the Ecliptic Plane, and its direction, together with the WMAP scan strategy, results in a strong coupling to the Y2, -1 component in Ecliptic co-ordinates. The dominant strength of this component in the measured quadrupole suggests that one should exercise increased caution in interpreting its estimated amplitude. The Planck satellite has a different scan strategy which does not so directly couple the dipole and quadrupole in this way and will soon provide an independent measurement.

  17. Induced CMB quadrupole from pointing offsets

    CERN Document Server

    Moss, Adam; Sigurdson, Kris

    2010-01-01

    Recent claims in the literature have suggested that the {\\it WMAP} quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than claimed. We discuss reasons why the {\\it WMAP} data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between the pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here -- the dipole signal lies close to the Ecliptic Plane, and its direction, together with t...

  18. Induced CMB quadrupole from pointing offsets

    Energy Technology Data Exchange (ETDEWEB)

    Moss, Adam; Scott, Douglas; Sigurdson, Kris, E-mail: adammoss@phas.ubc.ca, E-mail: dscott@phas.ubc.ca, E-mail: krs@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 Canada (Canada)

    2011-01-01

    Recent claims in the literature have suggested that the WMAP quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this result and delineate the key physics leading to the effect. We find that, even if real, the induced quadrupole would be smaller than the WMAP value. We discuss reasons why the WMAP data are unlikely to suffer from this particular systematic effect, including the implications for observations of point sources. Given this evidence against the reality of the effect, the similarity between the pointing-offset-induced signal and the actual quadrupole then appears to be quite puzzling. However, we find that the effect arises from a convolution between the gradient of the dipole field and anisotropic coverage of the scan direction at each pixel. There is something of a directional conspiracy here — the dipole signal lies close to the Ecliptic Plane, and its direction, together with the WMAP scan strategy, results in a strong coupling to the Y{sub 2,−1} component in Ecliptic co-ordinates. The dominant strength of this component in the measured quadrupole suggests that one should exercise increased caution in interpreting its estimated amplitude. The Planck satellite has a different scan strategy which does not so directly couple the dipole and quadrupole in this way and will soon provide an independent measurement.

  19. A high-speed and low-offset dynamic latch comparator.

    Science.gov (United States)

    Rahman, Labonnah Farzana; Bin Ibne Reaz, Mamun; Yin, Chia Chieu; Marufuzzaman, Mohammad; Rahman, Mohammad Anisur

    2014-01-01

    Circuit intricacy, speed, low-offset voltage, and resolution are essential factors for high-speed applications like analog-to-digital converters (ADCs). The comparator circuit with preamplifier increases the power dissipation, as it requires higher amount of currents than the latch circuitry. In this research, a novel topology of dynamic latch comparator is illustrated, which is able to provide high speed, low offset, and high resolution. Moreover, the circuit is able to reduce the power dissipation as the topology is based on latch circuitry. The cross-coupled circuit mechanism with the regenerative latch is employed for enhancing the dynamic latch comparator performance. In addition, input-tracking phase is used to reduce the offset voltage. The Monte-Carlo simulation results for the designed comparator in 0.18 μm CMOS process show that the equivalent input-referred offset voltage is 720 μV with 3.44 mV standard deviation. The simulated result shows that the designed comparator has 8-bit resolution and dissipates 158.5 μW of power under 1.8 V supply while operating with a clock frequency of 50 MHz. In addition, the proposed dynamic latch comparator has a layout size of 148.80 μm × 59.70 μm. PMID:25114959

  20. A High-Speed and Low-Offset Dynamic Latch Comparator

    Directory of Open Access Journals (Sweden)

    Labonnah Farzana Rahman

    2014-01-01

    Full Text Available Circuit intricacy, speed, low-offset voltage, and resolution are essential factors for high-speed applications like analog-to-digital converters (ADCs. The comparator circuit with preamplifier increases the power dissipation, as it requires higher amount of currents than the latch circuitry. In this research, a novel topology of dynamic latch comparator is illustrated, which is able to provide high speed, low offset, and high resolution. Moreover, the circuit is able to reduce the power dissipation as the topology is based on latch circuitry. The cross-coupled circuit mechanism with the regenerative latch is employed for enhancing the dynamic latch comparator performance. In addition, input-tracking phase is used to reduce the offset voltage. The Monte-Carlo simulation results for the designed comparator in 0.18 μm CMOS process show that the equivalent input-referred offset voltage is 720 μV with 3.44 mV standard deviation. The simulated result shows that the designed comparator has 8-bit resolution and dissipates 158.5 μW of power under 1.8 V supply while operating with a clock frequency of 50 MHz. In addition, the proposed dynamic latch comparator has a layout size of 148.80 μm×59.70 μm.

  1. 40 CFR 13.21 - Employee salary offset-general.

    Science.gov (United States)

    2010-07-01

    ....C. 5705, employee training expenses under 5 U.S.C. 4108 and to other debts where collection by... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Employee salary offset-general. 13.21... STANDARDS Administrative Offset § 13.21 Employee salary offset—general. (a) Purpose. This...

  2. PILOT-BASED FREQUENCY OFFSET DETECTION SCHEME IN OFDM SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Du Zheng; Zhu Jinkang

    2003-01-01

    The frequency offset information is extracted from local pilot amplitude characteristics, which suffer much less distortion in frequency-selective fading channels than those utilizing frequency domain correlation techniques. Simulation shows that the performance of this scheme has better performance than the existing frequency domain pilot-based frequency offset detection scheme.

  3. 5 CFR 185.144 - Right to administrative offset.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Right to administrative offset. 185.144 Section 185.144 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PROGRAM FRAUD CIVIL REMEDIES § 185.144 Right to administrative offset. The amount of any penalty or...

  4. Frequency-Offset Cartesian Feedback Based on Polyphase Difference Amplifiers

    OpenAIRE

    Zanchi, Marta G.; Pauly, John M.; Scott, Greig C

    2010-01-01

    A modified Cartesian feedback method called “frequency-offset Cartesian feedback” and based on polyphase difference amplifiers is described that significantly reduces the problems associated with quadrature errors and DC-offsets in classic Cartesian feedback power amplifier control systems.

  5. Offset-Control Attenuates Context Conditioning Induced by US-unpredictability in a Human Conditioned Suppression Paradigm

    Directory of Open Access Journals (Sweden)

    Ann Meulders

    2013-03-01

    Full Text Available We investigated whether offset-control of the unconditioned stimulus (US reduces context conditioning induced by US-unpredictability within a human conditioned suppression preparation. We also examined lack of control 'vs'. loss of control. Three groups (No Controllability, NC; Controllability, C; Loss of Controllability, LC received unsignaled USs during two learning phases (ACQ1-2. The NC group, never had offset-control, whereas the C group, always had offset-control. The LC group, had offset-control during ACQ1, but not during ACQ2. Results indicated that US-unpredictability led to contextual conditioned suppression during ACQ1, only when participants did not have offset-control; when they did, no context conditioning was established. From ACQ1 to ACQ2, contextual conditioned suppression increased in the LC group, but it was not more pronounced than in the NC group. These data suggest that offset-control attenuates context conditioning induced by US-unpredictability and – at least in this paradigm – loss of control is not worse than lack of control.

  6. Measuring coseismic displacements with point-like targets offset tracking

    KAUST Repository

    Hu, Xie

    2014-01-01

    Offset tracking is an important complement to measure large ground displacements in both azimuth and range dimensions where synthetic aperture radar (SAR) interferometry is unfeasible. Subpixel offsets can be obtained by searching for the cross-correlation peak calculated from the match patches uniformly distributed on two SAR images. However, it has its limitations, including redundant computation and incorrect estimations on decorrelated patches. In this letter, we propose a simple strategy that performs offset tracking on detected point-like targets (PT). We first detect image patches within bright PT by using a sinc-like template from a single SAR image and then perform offset tracking on them to obtain the pixel shifts. Compared with the standard method, the application on the 2010 M 7.2 El Mayor-Cucapah earthquake shows that the proposed PT offset tracking can significantly increase the cross-correlation and thus result in both efficiency and reliability improvements. © 2013 IEEE.

  7. Femoral head-neck offset in the Indian population: A CT based study

    Directory of Open Access Journals (Sweden)

    Rajesh Malhotra

    2012-01-01

    Full Text Available Background: Femoroacetabular impingement has been postulated as the important cause of primary osteoarthritis in non dysplastic hips. We postulated that the rarity of primary osteoarthritis of hip in Indian population could be attributable to morphological differences, specifically to a lower prevalence of abnormal head-neck morphology. We conducted an anthropometric study to evaluate the prevalence of abnormal head-neck offset in Indian population and to correlate it with the low prevalence of primary osteoarthrosis in the Indian population. Materials and Methods: The computed tomography (CT images of 85 apparently normal hips were analysed. An axial image was created parallel to the central axis of the femoral neck and passing through the center of the femoral head using coronal scout view. This image was then used to calculate alpha and beta angles and the head-neck offset ratio. The measurements were made by two independent observers on two different occasions. Results: The prevalence of abnormal head-neck offset ratio was 11.7% and the mean alpha and beta angles were 45.6° and 40.6°, respectively. Pearson correlation coefficients for intra-observer and inter-observer agreement were, respectively, 0.84 and 0.80 for alpha angle, 0.80 and 0.77 for beta angle and 0.78 and 0.75 for head-neck offset ratio. The values were similar to those reported in the western population. Conclusion: The differences in the prevalence of hip osteoarthritis in Indian and western populations are not attributable to variation in the prevalence of abnormal head-neck offset.

  8. Adaptive Offset Correction for Intracortical Brain Computer Interfaces

    Science.gov (United States)

    Homer, Mark L.; Perge, János A.; Black, Michael J.; Harrison, Matthew T.; Cash, Sydney S.; Hochberg, Leigh R.

    2014-01-01

    Intracortical brain computer interfaces (iBCIs) decode intended movement from neural activity for the control of external devices such as a robotic arm. Standard approaches include a calibration phase to estimate decoding parameters. During iBCI operation, the statistical properties of the neural activity can depart from those observed during calibration, sometimes hindering a user’s ability to control the iBCI. To address this problem, we adaptively correct the offset terms within a Kalman filter decoder via penalized maximum likelihood estimation. The approach can handle rapid shifts in neural signal behavior (on the order of seconds) and requires no knowledge of the intended movement. The algorithm, called MOCA, was tested using simulated neural activity and evaluated retrospectively using data collected from two people with tetraplegia operating an iBCI. In 19 clinical research test cases, where a nonadaptive Kalman filter yielded relatively high decoding errors, MOCA significantly reduced these errors (10.6 ±10.1%; p<0.05, pairwise t-test). MOCA did not significantly change the error in the remaining 23 cases where a nonadaptive Kalman filter already performed well. These results suggest that MOCA provides more robust decoding than the standard Kalman filter for iBCIs. PMID:24196868

  9. Offset dual reflector antennas for very low sidelobes

    Science.gov (United States)

    Sletten, C. J.; Payne, W.; Shillue, W.

    1986-05-01

    Design procedures for controlling sidelobe levels with low losses in antenna aperture efficiencies are emphasized. A new subreflector edge shaping technique is described for reducing the far-out and back-direction sidelobes on dual reflector antennas. Corrugated horn feeds with wide semi-flare angles are used to improve the bandwidth of the offset Gregorian subreflector antenna. A study of 'ideal' dish aperture distributions is presented. It relates computed horn radiation illumination of the subreflector and paraboloid aperture with several of the best analytical models for achieving low near-in sidelobe levels. Dolph-Chebychev distributions on linear arrays are shown to be useful guides for attaining very low sidelobes. Subreflector shape synthesis computer programs are described for converting the horn illuminations that are near ideal to the best analytical aperture distributions. Shaping of only the subreflector edges can be used without main dish shaping in most cases to control the levels of far-out sidelobes, correct for horn phase errors, and approximate the ideal aperture distributions.

  10. An intercomparison of the thermal offset for different pyranometers

    Science.gov (United States)

    Sanchez, G.; Cancillo, M. L.; Serrano, A.

    2016-07-01

    An unprecedented intensive intercomparison campaign focused on the experimental measurement of the thermal offset of pyranometers has been conducted at Badajoz (Spain) with the participation of three main manufacturers. The purpose of this study is to compare the thermal offset of six commercially available pyranometers, being some of them widely used and others recently commercialized. In this campaign, the capping methodology has been used to experimentally measure the daytime thermal offset of the pyranometers. Thus, a short but intense campaign has been conducted in two selected summer days under clear-sky conditions, covering a large range of solar zenith angle, irradiance, and temperature. Along the campaign, a total of 305 capping events have been performed, 61 for each pyranometer. The daytime thermal offset obtained for different pyranometers ranges between 0 and -16.8 W/m2 depending on the environmental conditions, being sometimes notably higher than values estimated indoors by manufacturers. The thermal offset absolute value of all instruments shows a diurnal cycle, increasing from sunrise to central hours of the day and decreasing from midafternoon to sunset. The analysis demonstrates that thermal offset is notably higher and more variable during daytime than during nighttime, requiring specific daytime measurements. Main results emphasize the key role played by wind speed in modulating the thermal offset.

  11. Bayesian integer frequency offset estimator for MIMO-OFDM systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Carrier frequency offset (CFO) in MIMO-OFDM systems can be decoupled into two parts: fraction frequency offset (FFO) and integer frequency offset (IFO). The problem of IFO estimation is addressed and a new IFO estimator based on the Bayesian philosophy is proposed. Also, it is shown that the Bayesian IFO estimator is optimal among all the IFO estimators. Furthermore, the Bayesian estimator can take advantage of oversampling so that better performance can be obtained. Finally, numerical results show the optimality of the Bayesian estimator and validate the theoretical analysis.

  12. A currency for offsetting energy development impacts: horse-trading sage-grouse on the open market.

    Directory of Open Access Journals (Sweden)

    Kevin E Doherty

    Full Text Available BACKGROUND: Biodiversity offsets provide a mechanism to compensate for unavoidable damages from new energy development as the U.S. increases its domestic production. Proponents argue that offsets provide a partial solution for funding conservation while opponents contend the practice is flawed because offsets are negotiated without the science necessary to backup resulting decisions. Missing in negotiations is a biologically-based currency for estimating sufficiency of offsets and a framework for applying proceeds to maximize conservation benefits. METHODOLOGY/PRINCIPAL FINDINGS: Here we quantify a common currency for offsets for greater sage-grouse (Centrocercus urophasianus by estimating number of impacted birds at 4 levels of development commonly permitted. Impacts were indiscernible at 1-12 wells per 32.2 km(2. Above this threshold lek losses were 2-5 times greater inside than outside of development and bird abundance at remaining leks declined by -32 to -77%. Findings reiterated the importance of time-lags as evidenced by greater impacts 4 years after initial development. Clustering well locations enabled a few small leks to remain active inside of developments. CONCLUSIONS/SIGNIFICANCE: Documented impacts relative to development intensity can be used to forecast biological trade-offs of newly proposed or ongoing developments, and when drilling is approved, anticipated bird declines form the biological currency for negotiating offsets. Monetary costs for offsets will be determined by true conservation cost to mitigate risks such as sagebrush tillage to other populations of equal or greater number. If this information is blended with landscape level conservation planning, the mitigation hierarchy can be improved by steering planned developments away from conservation priorities, ensuring compensatory mitigation projects deliver a higher return for conservation that equate to an equal number of birds in the highest priority areas, provide on

  13. 29 CFR 4903.22 - Administrative offset procedures.

    Science.gov (United States)

    2010-07-01

    ... (access under the Freedom of Information Act (5 U.S.C. 552) or the Privacy Act (5 U.S.C. 552a...) Failure to take the offset would substantially prejudice the government's ability to collect the debt;...

  14. Analysis of DC offset Influence on Transient Signal

    Science.gov (United States)

    Wang, Y.; Lin, J.; Zhou, G. H.

    2006-10-01

    Based on the characteristic of transient signal and the principle of floating-point data acquisition circuit, the influences of DC offset on transient signal are analyzed. And the conclusion can be obtained that the singularity and saturation distortions in transient signals can be produced by DC offset through the detailed principle analysis, the limits calculation of DC offset, and waveform simulation while the DC offset is present in floating-point amplifier circuit of floating-point data acquisition circuit. At the same time, the distributions of distortions in those conditions that the single and several theoretic transient signals and also in actual measured transient signal are compared and discussed. Finally, the corresponding solutions are given according to the main factors which produce the waveform distortion. In a word, this research can provide useful references for the adjustment of floating-point receiver and the analysis of waveform distortion.

  15. Synthesis of offset-fed Gregorian VSAT antennas

    OpenAIRE

    Dubrovka, Fedor F.; Dubrovka, Rostyslav F.; Kim, Oleksiy S.; Syrotyuk, V. H.; Khymych, H. P.

    2003-01-01

    The paper presents results of synthesis, design, development, manufacturing and testing prototypes of 1.2 m, 1.8 m and 2.4 m Gregorian shaped offset dual-reflector antennas with low crosspolar radiation for VSAT applications.

  16. Public Budget Database - Budget Authority and offsetting receipts 1976-Current

    Data.gov (United States)

    Executive Office of the President — This file contains historical budget authority and offsetting receipts for 1976 through the current budget year, as well as four years of projections. It can be...

  17. Public Budget Database - Outlays and offsetting receipts 1962-Current

    Data.gov (United States)

    Executive Office of the President — This file contains historical outlays and offsetting receipts for 1962 through the current budget year, as well as four years of projections. It can be used to...

  18. Pair Cascades and Deathlines in Offset Magnetic Dipole Fields

    Science.gov (United States)

    Harding, Alice; Muslimov, Alex

    2010-01-01

    We investigate electron-positron pair cascades in a dipole magnetic field whose axis is offset from the neutron star center. In such a field geometry, the polar cap is displaced from the neutron star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the polar cap of an offset dipole, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset parameter. We find that the pair multiplicity can change dramatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity.

  19. Hanford Site background: Part 3, Groundwater background

    International Nuclear Information System (INIS)

    This report presents and interprets groundwater background data collected from the unconfined aquifer beneath the Hanford Site, a U.S. Department of Energy complex located near Richland, Washington. Characterization of background composition is an important component of environmental characterization activities and serves as a basis for distinguishing the presence and significance of contamination. Background data can also be used to assess the levels of baseline risk to which humans or other receptors are typically exposed and to establish remediation goals. Evaluating background on a sitewide basis provides a consistent, technically defensible definition of background as opposed to determining area-specific background compositions for each waste management unit being considered for remediation across the Hanford Site

  20. Development by Design in Western Australia: Overcoming Offset Obstacles

    OpenAIRE

    James Fitzsimons; Michael Heiner; Bruce McKenney; Kei Sochi; Joseph Kiesecker

    2014-01-01

    Biodiversity offsets can be an important tool for maintaining or enhancing environmental values in situations where development is sought despite negative environmental impacts. There are now approximately 45 compensatory mitigation programs for biodiversity impacts worldwide, with another 27 programs in development. While offsets have great potential as a conservation tool, their establishment requires overcoming a number of conceptual and methodological hurdles. In Australia, new policy cha...

  1. Spatially Offset Active Galactic Nuclei. I. Selection and Spectroscopic Properties

    Science.gov (United States)

    Barrows, R. Scott; Comerford, Julia M.; Greene, Jenny E.; Pooley, David

    2016-09-01

    We present a sample of 18 optically selected and X-ray-detected spatially offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey (SDSS). In nine systems, the X-ray active galactic nucleus (AGN) is spatially offset from the galactic stellar core that is located within the 3″ diameter SDSS spectroscopic fiber. In 11 systems, the X-ray AGN is spatially offset from a stellar core that is located outside the fiber, with an overlap of two. To build the sample, we cross-matched Type II AGNs selected from the SDSS galaxy catalog with archival Chandra imaging and employed our custom astrometric and registration procedure. The projected angular (physical) offsets span a range of 0.″6 (0.8 kpc) to 17.″4 (19.4 kpc), with a median value of 2.″7 (4.6 kpc). The offset nature of an AGN is an unambiguous signature of a galaxy merger, and these systems can be used to study the properties of AGNs in galaxy mergers without the biases introduced by morphological merger selection techniques. In this paper (Paper I), we use our sample to assess the kinematics of AGN photoionized gas in galaxy mergers. We find that spectroscopic offset AGN selection may be up to {89}-16+7% incomplete due to small projected velocity offsets. We also find that the magnitude of the velocity offsets are generally larger than expected if our spatial selection introduces a bias toward face-on orbits, suggesting the presence of complex kinematics in the emission line gas of AGNs in galaxy mergers.

  2. Evaluating the Effectiveness of Offsets as a Mechanism for Promoting Malaysian Defence Industrial and Technological Development

    OpenAIRE

    Balakrishnan, Kogila

    2008-01-01

    Offsets have taken centre stage in defence trade. To date, more than 78 countries around the world practice offsets and outstanding offsets obligations run into billions of US dollars However, why have offsets gained such a momentum? Increasingly, both sellers and buyers in the arms trade view offsets as an efficient and effective economic compensation tool to justify arms deals. Buyers, consider offsets as a catalyst for industrial and technological development, employment, cr...

  3. Time-resolved spatially offset Raman spectroscopy for depth analysis of diffusely scattering layers.

    Science.gov (United States)

    Iping Petterson, Ingeborg E; Dvořák, Patrick; Buijs, Joost B; Gooijer, Cees; Ariese, Freek

    2010-12-01

    The objective of this study is to use time-resolved (TR) Raman spectroscopy, spatially offset Raman spectroscopy (SORS), and a combination of these approaches to obtain high quality Raman spectra from materials hidden underneath an opaque layer. Both TR Raman and SORS are advanced techniques that allow for an increased relative selectivity of photons from deeper layers within a sample. Time-resolved detection reduces fluorescence background, and the selectivity for the second layer is improved. By combining this with spatially offset excitation we additionally increased selectivity for deeper layers. Test samples were opaque white polymer blocks of several mm thicknesses. Excitation was carried out with a frequency-doubled Ti:sapphire laser at 460 nm, 3 ps pulse width and 76 MHz repetition rate. Detection was either with a continuous-wave CCD camera or in time-resolved mode using an intensified CCD camera with a 250 ps gate width. The Raman photons were collected in backscatter mode, with or without lateral offset. By measuring the delay of the Raman signal from the second layer (polyethylene terephthalate/PET/Arnite), the net photon migration speeds through Teflon, polythene, Delrin and Nylon were determined. Raman spectra could be obtained from a second layer of PET through Teflon layers up to 7 mm of thickness. The ability to obtain chemical information through layers of diffusely scattering materials has powerful potential for biomedical applications.

  4. Rationale and design of LAPLACE-2: a phase 3, randomized, double-blind, placebo- and ezetimibe-controlled trial evaluating the efficacy and safety of evolocumab in subjects with hypercholesterolemia on background statin therapy.

    Science.gov (United States)

    Robinson, Jennifer G; Rogers, William J; Nedergaard, Bettina S; Fialkow, Jonathan; Neutel, Joel M; Ramstad, David; Somaratne, Ransi; Legg, Jason C; Nelson, Patric; Scott, Rob; Wasserman, Scott M; Weiss, Robert

    2014-04-01

    Low-density lipoprotein cholesterol (LDL-C) levels are significantly associated with atherosclerotic cardiovascular disease (ASCVD) risk, and studies using interventions that lower LDL-C levels have been shown to reduce the risk of ASCVD events and mortality. Statin treatment is the current first-line therapy for lowering LDL-C and reducing ASCVD risk. However, many patients are still unable to reach recommended LDL-C goals on maximally tolerated statin therapy. Monoclonal antibodies that inhibit proprotein convertase subtilisin/kexin type 9, including evolocumab (previously AMG 145), dramatically lowered LDL-C in phase 2 clinical trials when administered alone or in combination with a statin. The aim of this phase 3 study is to evaluate the efficacy of 12 weeks of subcutaneous evolocumab (vs placebo) administered every 2 weeks or every month in combination with a statin in patients with hypercholesterolemia and mixed dyslipidemia. This study will also provide comparative efficacy, safety, and tolerability data between evolocumab and ezetimibe when added to background atorvastatin therapy.

  5. Common-image gathers in the offset domain from reverse-time migration

    KAUST Repository

    Zhan, Ge

    2014-04-01

    Kirchhoff migration is flexible to output common-image gathers (CIGs) in the offset domain by imaging data with different offsets separately. These CIGs supply important information for velocity model updates and amplitude-variation-with-offset (AVO) analysis. Reverse-time migration (RTM) offers more insights into complex geology than Kirchhoff migration by accurately describing wave propagation using the two-way wave equation. But, it has difficulty to produce offset domain CIGs like Kirchhoff migration. In this paper, we develop a method for obtaining offset domain CIGs from RTM. The method first computes the RTM operator of an offset gather, followed by a dot product of the operator and the offset data to form a common-offset RTM image. The offset domain CIGs are then achieved after separately migrating data with different offsets. We generate offset domain CIGs on both the Marmousi synthetic data and 2D Gulf of Mexico real data using this approach. © 2014.

  6. Beam-Generated Detector Backgrounds at CESR

    OpenAIRE

    Henderson, Stuart; Cinabro, David

    2000-01-01

    The CESR/CLEO Phase II interaction region is described. The operational experience with beam-generated detector backgrounds is reviewed. The status of our understanding of beam-generated detector backgrounds at CESR is described and comparisons of background measurements with simulation predictions are presented.

  7. Spatially Offset Active Galactic Nuclei I: Selection and Spectroscopic Properties

    CERN Document Server

    Barrows, R Scott; Greene, Jenny E; Pooley, David

    2016-01-01

    We present a sample of 18 optically-selected and X-ray detected spatially offset active galactic nuclei (AGN) from the Sloan Digital Sky Survey (SDSS). In 9 systems, the X-ray AGN is spatially offset from the galactic stellar core that is located within the 3'' diameter SDSS spectroscopic fiber. In 11 systems, the X-ray AGN is spatially offset from a stellar core that is located outside the fiber, with an overlap of 2. To build the sample, we cross-matched Type II AGN selected from the SDSS galaxy catalogue with archival Chandra imaging and employed our custom astrometric and registration procedure. The projected angular (physical) offsets span a range of 0."6 (0.8 kpc) to 17."4 (19.4 kpc), with a median value of 2."7 (4.6 kpc). The offset nature of an AGN is an unambiguous signature of a galaxy merger, and these systems can be used to study the properties of AGN in galaxy mergers without the biases introduced by morphological merger selection techniques. In this paper (Paper I), we use our sample to assess t...

  8. Lower limb length and offset in total hip arthroplasty.

    Science.gov (United States)

    Flecher, X; Ollivier, M; Argenson, J N

    2016-02-01

    Restoration of normal hip biomechanics is a key goal of total hip arthroplasty (THA) and favorably affects functional recovery. Furthermore, a major concern for both the surgeon and the patient is preservation or restoration of limb length equality, which must be achieved without compromising the stability of the prosthesis. Here, definitions are given for anatomic and functional limb length discrepancies and for femoral and hip offset, determined taking anteversion into account. Data on the influence of operated-limb length and offset on patient satisfaction, hip function, and prosthesis survival after THA are reviewed. Errors may adversely impact function, quality of life, and prosthetic survival and may also generate conflicts between the surgeon and patient. Surgeons rely on two- or three-dimensional preoperative templating and on intraoperative landmarks to manage offset and length. Accuracy can be improved by using computer-assisted planning or surgery and the more recently introduced EOS imaging system. The prosthetic's armamentarium now includes varus-aligned and lateralized implants, as well as implants with modular or custom-made necks, which allow restoration of the normal hip geometry, most notably in patients with coxa vara or coxa valga. Femoral anteversion must also receive careful attention. The most common errors are limb lengthening and a decrease in hip offset. When symptoms are caused by an error in length and/or offset, revision arthroplasty may deserve consideration. PMID:26797005

  9. Biodiversity offsets and caribou conservation in Alberta: opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Christine B. Robichaud

    2015-12-01

    Full Text Available The federal recovery strategy for boreal woodland caribou (Rangifer tarandus caribou sets a goal of self-sustaining populations for all caribou ranges across Canada. All caribou herds in Alberta are currently designated as not self-sustaining and the recovery strategy requires an action plan to achieve self-sustaining status. At the same time, continued natural resource extraction in caribou ranges may be worth hundreds of billions of dollars. Some regulatory bodies have recognized an opportunity for biodiversity offsets to help meet the caribou recovery strategy’s goals while still permitting economic benefits of development. In this review, we evaluate offset opportunities for caribou in Alberta and practical impediments for implementation. We conclude that a number of actions to offset impacts of development and achieve no net loss or net positive impact for caribou are theoretically feasible (i.e., if implemented they should work, including habitat restoration and manipulations of the large mammal predator-prey system. However, implementation challenges are substantial and include a lack of mechanisms for setting aside some resources for long periods of time, public opposition to predator control, and uncertainty associated with loss-gain calculations. A framework and related policy for offsets are currently lacking in Alberta and their development is urgently needed to guide successful design and implementation of offsets for caribou.

  10. An offset tone based gain stabilization technique for mixed-signal RF measurement systems

    Science.gov (United States)

    Joshi, Gopal; Motiwala, Paresh D.; Randale, G. D.; Singh, Pitamber; Agarwal, Vivek; Kumar, Girish

    2015-09-01

    This paper describes a gain stabilization technique for a RF signal measurement system. A sinusoidal signal of known amplitude, phase and close enough in frequency is added to the main, to be measured RF signal at the input of the analog section. The system stabilizes this offset tone in the digital domain, as it is sampled at the output of the analog section. This process generates a correction factor needed to stabilize the magnitude of the gain of the analog section for the main RF signal. With the help of a simple calibration procedure, the absolute amplitude of the main RF signal can be measured. The technique is especially suited for a system that processes signals around a single frequency, employs direct signal conversion into the digital domain, and processes subsequent steps in an FPGA. The inherent parallel signal processing in an FPGA-based implementation allows a real time stabilization of the gain. The effectiveness of the technique is derived from the fact, that the gain stabilization stamped to the main RF signal measurement branch requires only a few components in the system to be inherently stable. A test setup, along with experimental results is presented from the field of RF instrumentation for particle accelerators. Due to the availability of a phase synchronized RF reference signal in these systems, the measured phase difference between the main RF and the RF reference is also stabilized using this technique. A scheme of the signal processing is presented, where a moving average filter has been used to filter out not only the unwanted frequencies, but also to separate the main RF signal from the offset tone signal. This is achieved by a suitable choice of sampling and offset tone frequencies. The presented signal processing scheme is suitable to a variety of RF measurement applications.

  11. A Novel Minimum Output Variance Estimator for Carrier Frequency Offset in OFDM Systems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In orthogonal frequency-division multiplexing (OFDM) systems, the carrier frequency offset (CFO)destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have been developed to compensate for the CFO at the receiver. This paper describes a novel minimum output variance method for OFDM systems with CFO in additive white Gaussian noise channels.This method utilizes the phase and the amplitude of the received signal and reduces the mean square error of the CFO by about 3 dB compared with the original minimum output variance method.

  12. Background Independent String Field Theory

    CERN Document Server

    Bars, Itzhak

    2014-01-01

    We develop a new background independent Moyal star formalism in bosonic open string field theory. The new star product is formulated in a half-phase-space, and because phase space is independent of any background fields, the interactions are background independent. In this basis there is a large amount of symmetry, including a supersymmetry OSp(d|2) that acts on matter and ghost degrees of freedom, and simplifies computations. The BRST operator that defines the quadratic kinetic term of string field theory may be regarded as the solution of the equation of motion A*A=0 of a purely cubic background independent string field theory. We find an infinite number of non-perturbative solutions to this equation, and are able to associate them to the BRST operator of conformal field theories on the worldsheet. Thus, the background emerges from a spontaneous-type breaking of a purely cubic highly symmetric theory. The form of the BRST field breaks the symmetry in a tractable way such that the symmetry continues to be us...

  13. Flow and heat transfer in compact offset strip fin surfaces

    Institute of Scientific and Technical Information of China (English)

    Junqi DONG; Jiangping CHEN; Zhijiu CHEN

    2008-01-01

    Experimental studies of air-side heat transfer and pressure drop characteristics of offset strip fins and flat tube heat exchangers were performed. A series of tests were conducted for 9 heat exchangers with different fin space, fin height, fin strip length and flow length, at a constant tube-side water flow rate of 2.5 m3/h. The char-acteristics of the heat transfer and pressure drop of differ-ent fin space, fin height and fin length were analyzed and compared. The curves of the heat transfer coefficients vs. The pumping power per unit frontal area were then plot-ted. Moreover, the enhanced heat transfer mechanism of offset strip fins was analyzed using field synergy theory. The results showed that fin length and flow length have more obviously effect on the thermal hydraulic character-istics of offset strip fins.

  14. Diffraction profile synthesis applied to offset dual reflector antennas

    Science.gov (United States)

    Henderson, R. I.

    1985-05-01

    During the last 15 years, in work carried out at a research center, the physical optics method has been applied directly to the synthesis process itself. It is pointed out that the results of this method, known as Diffraction Profile Synthesis (DPS), are Cassegrain antennas with efficiencies superior to those of any ray optics design. Thus, the reflectors generated by this process realize the theoretical maximum efficiency for any given size of antenna. Attention is given to the diffraction profile synthesis, the extension of DPS, spherical wave expansions, the application to offset reflectors, the main reflector focussed field, the near-field feed pattern, reflector perturbations, profile smoothing, high efficiency offset Gregorian, the offset Gregorian with Hansen distribution, and the low sidelobe elliptical antenna.

  15. The seam offset identification based on support vector regression machines

    Institute of Scientific and Technical Information of China (English)

    Zeng Songsheng; Shi Yonghua; Wang Guorong; Huang Guoxing

    2009-01-01

    The principle of the support vector regression machine(SVR) is first analysed. Then the new data-dependent kernel function is constructed from information geometry perspective. The current waveforms change regularly in accordance with the different horizontal offset when the rotational frequency of the high speed rotational arc sensor is in the range from 15 Hz to 30 Hz. The welding current data is pretreated by wavelet filtering, mean filtering and normalization treatment. The SVR model is constructed by making use of the evolvement laws, the decision function can be achieved by training the SVR and the seam offset can be identified. The experimental results show that the precision of the offset identification can be greatly improved by modifying the SVR and applying mean filtering from the longitudinal direction.

  16. Using Audio-Derived Affective Offset to Enhance TV Recommendation

    DEFF Research Database (Denmark)

    Shepstone, Sven Ewan; Tan, Zheng-Hua; Jensen, Søren Holdt

    2014-01-01

    . First a user's mood profile is determined using 12-class audio-based emotion classifications . An initial TV content item is then displayed to the user based on the extracted mood profile. The user has the option to either accept the recommendation, or to critique the item once or several times, by...... navigating the emotion space to request an alternative match. The final match is then compared to the initial match, in terms of the difference in the items' affective parameterization . This offset is then utilized in future recommendation sessions. The system was evaluated by eliciting three different...... moods in 22 separate users and examining the influence of applying affective offset to the users' sessions. Results show that, in the case when affective offset was applied, better user satisfaction was achieved: the average ratings went from 7.80 up to 8.65, with an average decrease in the number of...

  17. Contact of surfaces and contact characteristics of offset surfaces

    Institute of Scientific and Technical Information of China (English)

    Lixin CAO; Hu GONG; Jian LIU

    2008-01-01

    Based on differential geometry, the contact problems of two surfaces are discussed in this paper. The relationship between the contact status of two sur-faces and that of offset surfaces are also analyzed. For a 5-axis NC machining, some research such as optimization of cutter location and calculation of the geometrical cusp height are important. The research results indicate that the relative normal curvature is an important geometrical invariant for describing the contact state of two surfaces. For point contact two surfaces, the calculation equation for the second order remained error is given. For line contact two surfaces, the condition of the second order line contact is that the principal directions and curvatures of the two surfaces are the same along the contact curve. If two surfaces keep the second order line contact, their two offset surfaces will also keep the second order line contact, and their third order remained errors are also uniform with that of the two offset surfaces.

  18. A 3D measurement of the offset in paleoseismological studies

    Science.gov (United States)

    Ferrater, Marta; Echeverria, Anna; Masana, Eulàlia; Martínez-Díaz, José J.; Sharp, Warren D.

    2016-05-01

    The slip rate of a seismogenic fault is a crucial parameter for establishing the contribution of the fault to the seismic hazard. It is calculated from measurements of the offset of linear landforms, such channels, produced by the fault combined with their age. The three-dimensional measurement of offset in buried paleochannels is subject to uncertainties that need to be quantitatively assessed and propagated into the slip rate. Here, we present a set of adapted scripts to calculate the net, lateral and vertical tectonic offset components caused by faults, together with their associated uncertainties. This technique is applied here to a buried channel identified in the stratigraphic record during a paleoseismological study at the El Saltador site (Alhama de Murcia fault, Iberian Peninsula). After defining and measuring the coordinates of the key points of a buried channel in the walls of eight trenches excavated parallel to the fault, we (a) adjusted a 3D straight line to these points and then extrapolated the tendency of this line onto a simplified fault plane; (b) repeated these two steps for the segment of the channel in the other side of the fault; and (c) measured the distance between the two resulting intersection points with the fault plane. In doing so, we avoided the near fault modification of the channel trace and obtained a three-dimensional measurement of offset and its uncertainty. This methodology is a substantial modification of previous procedures that require excavating progressively towards the fault, leading to possible underestimation of offset due to diffuse deformation near the fault. Combining the offset with numerical dating of the buried channel via U-series on soil carbonate, we calculated a maximum estimate of the net slip rate and its vertical and lateral components for the Alhama de Murcia fault.

  19. Is there any empirical support for biodiversity offset policy?

    Science.gov (United States)

    Curran, Michael; Hellweg, Stefanie; Beck, Jan

    2014-06-01

    Biodiversity offsets are seen as a policy mechanism to balance development and conservation goals. Many offset schemes employ habitat restoration in one area to recreate biodiversity value that is destroyed elsewhere, assuming that recovery is timely and predictable. Recent research has challenged these assumptions on the grounds that restoration implies long time delays and a low certainty of success. To investigate these assertions, and to assess the strength of empirical support for offset policy, we used a meta-analytic approach to analyze data from 108 comparative studies of secondary growth (SG) and old-growth (OG) habitat (a total of 1228 SG sites and 716 OG reference sites). We extracted species checklists and calculated standardized response ratios for species richness, Fisher's alpha, Sorenson similarity, and Morisita-Horn similarity. We modeled diversity change with habitat age using generalized linear models and multi-model averaging, correcting for a number of potential explanatory variables. We tested whether (1) diversity of passively and actively restored habitat converges to OG values over time, (2) active restoration significantly accelerates this process, and (3) current offset policies are appropriate to the predicted uncertainties and time lags associated with restoration. The results indicate that in the best case, species richness converges to OG reference values within a century, species similarity (Sorenson) takes about twice as long, and assemblage composition (Morisita-Horn) up to an order of magnitude longer (hundreds to thousands of years). Active restoration significantly accelerates the process for all indices, but the inherently large time lags, uncertainty, and risk of restoration failure require offset ratios that far exceed what is currently applied in practice. Restoration offset policy therefore leads to a net loss of biodiversity, and represents an inappropriate use of the otherwise valuable tool of ecosystem restoration. PMID

  20. Pulsar Pair Cascades in Magnetic Fields with Offset Polar Caps

    Science.gov (United States)

    Harding, Alice K.; Muslimov, Alex G.

    2012-01-01

    Neutron star magnetic fields may have polar caps (PC) that are offset from the dipole axis, through field-line sweepback near the light cylinder or non-symmetric currents within the star. The effects of such offsets on electron-positron pair cascades are investigated, using simple models of dipole magnetic fields with small distortions that shift the PCs by different amounts or directions. Using a Monte Carlo pair cascade simulation, we explore the changes in the pair spectrum, multiplicity and energy flux across the PC, as well as the trends in pair flux and pair energy flux with spin-down luminosity, L(sub sd). We also give an estimate of the distribution of heating flux from returning positrons on the PC for different offsets. We find that even modest offsets can produce significant increases in pair multiplicity, especially for pulsars that are near or beyond the pair death lines for centered PCs, primarily because of higher accelerating fields. Pair spectra cover several decades in energy, with the spectral range of millisecond pulsars (MSPs) two orders of magnitude higher than for normal pulsars, and PC offsets allow significant extension of all spectra to lower pair energies. We find that the total PC pair luminosity L(sub pair) is proportional to L(sub sd), with L(sub pair) approximates 10(exp -3) L(sub sd) for normal pulsars and L(sub pair) approximates 10(exp -2) L(sub sd) for MSPs. Remarkably, the total PC heating luminosity for even large offsets increases by less than a factor of two, even though the PC area increases by much larger factors, because most of the heating occurs near the magnetic axis.

  1. Optimization based tuning approach for offset free MPC

    DEFF Research Database (Denmark)

    Olesen, Daniel Haugård; Huusom, Jakob Kjøbsted; Jørgensen, John Bagterp

    2012-01-01

    We present an optimization based tuning procedure with certain robustness properties for an offset free Model Predictive Controller (MPC). The MPC is designed for multivariate processes that can be represented by an ARX model. The advantage of ARX model representations is that standard system...... identifiation techniques using convex optimization can be used for identification of such models from input-output data. The stochastic model of the ARX model identified from input-output data is modified with an ARMA model designed as part of the MPC-design procedure to ensure offset-free control. The ARMAX...

  2. Offset removing in the domain of signal shapes

    OpenAIRE

    Rix, Hervé

    2011-01-01

    National audience The recognition of a given shape in a positive signal using the Distribution Function Method (DFM) assumes an affine transform on the abscissa and only a multiplicative coefficient on the ordinates, without any offset. The aim of the paper is to extent DFM when shape equality includes an offset. In fact, this problem is a particular case of signal shape recognition in a sum of two signals whose shapes are known. The first application in mind is the beat to beat extraction...

  3. Baseline correction of phase-contrast images in congenital cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Lai Wyman W

    2010-03-01

    Full Text Available Abstract Background One potential source of error in phase contrast (PC congenital CMR flow measurements is caused by phase offsets due to local non-compensated eddy currents. Phantom correction of these phase offset errors has been shown to result in more accurate measurements of blood flow in adults with structurally normal hearts. We report the effect of phantom correction on PC flow measurements at a clinical congenital CMR program. Results Flow was measured in the ascending aorta, main pulmonary artery, and right and left pulmonary arteries as clinically indicated, and additional values such as Qp/Qs were derived from these measurements. Phantom correction in our study population of 149 patients resulted in clinically significant changes in 13% to 48% of these phase-contrast measurements in patients with known or suspected heart disease. Overall, 640 measurements or calculated values were analyzed, and clinically significant changes were found in 31%. Larger vessels were associated with greater phase offset errors, with 22% of the changes in PC flow measurements attributed to the size of the vessel measured. In patients with structurally normal hearts, the pulmonary-to-systemic flow ratio after phantom correction was closer to 1.0 than before phantom correction. There was no significant difference in the effect of phantom correction for patients with tetralogy of Fallot as compared to the group as a whole. Conclusions Phantom correction often resulted in clinically significant changes in PC blood flow measurements in patients with known or suspected congenital heart disease. In laboratories performing clinical CMR with suspected phase offset errors of significance, the routine use of phantom correction for PC flow measurements should be considered.

  4. The use of airborne laser scanning to develop a pixel-based stratification for a verified carbon offset project

    OpenAIRE

    Carah Jennifer; Hanus Mark; Golinkoff Jordan

    2011-01-01

    Abstract Background The voluntary carbon market is a new and growing market that is increasingly important to consider in managing forestland. Monitoring, reporting, and verifying carbon stocks and fluxes at a project level is the single largest direct cost of a forest carbon offset project. There are now many methods for estimating forest stocks with high accuracy that use both Airborne Laser Scanning (ALS) and high-resolution optical remote sensing data. However, many of these methods are n...

  5. Building Background Knowledge

    Science.gov (United States)

    Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley

    2014-01-01

    This article make a case for the importance of background knowledge in children's comprehension. It suggests that differences in background knowledge may account for differences in understanding text for low- and middle-income children. It then describes strategies for building background knowledge in the age of common core standards.

  6. Method to Minimize the Low-Frequency Neutral-Point Voltage Oscillations With Time-Offset Injection for Neutral-Point-Clamped Inverters

    DEFF Research Database (Denmark)

    Choi, Ui-Min; Blaabjerg, Frede; Lee, Kyo-Beum

    2015-01-01

    This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time offset to the three-phase turn-on times. The proper time offset is simply calculated considering the phase currents and dwe...... also proposed. The change in switching frequency by the proposed method and its effects on the outputs are negligible. Simulation and experimental results verify the validity and feasibility of the proposed strategy....

  7. Method to minimize the low-frequency neutral-point voltage oscillations with time-offset injection for neutral-point-clamped inverters

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, Kyo-Beum; Blaabjerg, Frede

    2013-01-01

    time of small and medium voltage vectors. The proposed method does not affect the outputs and there is no increase in the switching frequency. Further, it does not require additional hardware or complex calculations. Simulation and experimental results verify the validity and feasibility......This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time-offset to the three phase turn-on times. The proper time-offset is simply calculated considering the phase currents and dwell...

  8. Applications of spatially offset Raman spectroscopy to defense and security

    Science.gov (United States)

    Guicheteau, Jason; Hopkins, Rebecca

    2016-05-01

    Spatially offset Raman spectroscopy (SORS) allows for sub-surface and through barrier detection and has applications in drug analysis, cancer detection, forensic science, as well as defense and security. This paper reviews previous efforts in SORS and other through barrier Raman techniques and presents a discussion on current research in defense and security applications.

  9. Forest Carbon Offsets Revisited: Shedding Light on Darkwoods

    NARCIS (Netherlands)

    Kooten, van G.C.; Bogle, T.; Vries, de F.P.

    2015-01-01

    This paper investigates the viability of carbon offset credits created through forest conservation and preservation. A detailed forest management model based on a case study of a forest estate in southeastern British Columbia, owned by The Nature Conservancy of Canada (NCC) is used to demonstrate th

  10. Anisotropic parameter estimation using velocity variation with offset analysis

    Energy Technology Data Exchange (ETDEWEB)

    Herawati, I.; Saladin, M.; Pranowo, W.; Winardhie, S.; Priyono, A. [Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, 40132 (Indonesia)

    2013-09-09

    Seismic anisotropy is defined as velocity dependent upon angle or offset. Knowledge about anisotropy effect on seismic data is important in amplitude analysis, stacking process and time to depth conversion. Due to this anisotropic effect, reflector can not be flattened using single velocity based on hyperbolic moveout equation. Therefore, after normal moveout correction, there will still be residual moveout that relates to velocity information. This research aims to obtain anisotropic parameters, ε and δ, using two proposed methods. The first method is called velocity variation with offset (VVO) which is based on simplification of weak anisotropy equation. In VVO method, velocity at each offset is calculated and plotted to obtain vertical velocity and parameter δ. The second method is inversion method using linear approach where vertical velocity, δ, and ε is estimated simultaneously. Both methods are tested on synthetic models using ray-tracing forward modelling. Results show that δ value can be estimated appropriately using both methods. Meanwhile, inversion based method give better estimation for obtaining ε value. This study shows that estimation on anisotropic parameters rely on the accuracy of normal moveout velocity, residual moveout and offset to angle transformation.

  11. A Meta-Regression Analysis of Forest Carbon Offset Costs

    NARCIS (Netherlands)

    Kooten, van G.C.; Laaksonen-Craig, S.; Wang, Y.

    2009-01-01

    The main focus of efforts to mitigate climate change is on the avoidance of fossil fuel emissions. However, the Kyoto Protocol rules permit the use of forestry activities that create carbon offset credits. These could obviate the need for lifestyle-changing reductions in fossil fuel use. Therefore,

  12. 76 FR 24406 - Collection by Offset From Indebted Government Employees

    Science.gov (United States)

    2011-05-02

    ... offset. The proposed regulations conform with an amendment made by the Food, Conservation, and Energy Act... amendment to 31 U.S.C. 3716(e) made by section 14219 of the Food, Conservation, and Energy Act of 2008 (Pub... to reflect this change (see 74 FR 68537, December 28, 2009). To avoid any undue hardship,...

  13. Continental Announces Carbon Offsetting Program with Sustainable Travel International

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ On December 3,2007,HOUSTON,-Continental Airlines announced that it has launched acarbon offsetting program,developed in partnership with non-profit Sustainable Travel International which is a US-based non-profit organization whose mission is to promote sustainable development and responsible travel by providing programs.

  14. Performance Comparison of Symmetric and Offset Reflector Antennas Adaptively Illuminated by Novel Triple Mode Feedhorn

    Directory of Open Access Journals (Sweden)

    Satish K. Sharma

    2012-01-01

    Full Text Available Parabolic symmetric and offset reflector antennas adaptively illuminated using a novel triple-mode feedhorn (TE11+TM01+TE21 with different mode combinations and impedance and radiation performances are presented. The combination of the radiating modes in a feedhorn with proper amplitude and fixed phase values helps in electronically pointing the main beam of the radiating patterns such as that obtained in a beam-steering antenna with limited beam-scan range. This type of radiation performance virtually creates a displaced phase center location for the feedhorn, which, consequently, adaptively illuminates the reflector antenna surface. Impedance-matching bandwidths are preserved for both reflector antennas similar to the case of feedhorn alone. The copolarization gain and peak cross-polarization levels are far better with the offset reflector antenna than the symmetric reflector antenna. Such reflector antennas find applications in ground moving target indicator (GMTI and space based radars. The investigation results are solely computed using FEKO full-wave analysis tool.

  15. 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.

  16. Detection of object onsets and offsets: Does the primacy of onset persist even with bias for detecting offset?

    Science.gov (United States)

    Donaldson, Maria J; Yamamoto, Naohide

    2016-10-01

    Onset primacy is a robust visual phenomenon in which appearance of new objects (onsets) in a scene more effectively captures observers' attention compared with disappearance of previously viewed objects (offsets). We hypothesized that the human attentional system is programmed by default to prioritize the processing of onsets, because quick detection of them is advantageous in most situations. However, the attentional priority may be able to flexibly adapt to the detection of object offsets depending on observers' behavioral goals. To test these hypotheses, two experiments were conducted in which participants were biased toward finding offset of an existing object through top-down and bottom-up manipulations. Results showed that although onset primacy was reduced to some degree under strong offset bias, in general participants continued to detect onsets efficiently. These findings did not eliminate the possibility of attentional flexibility, but they do demonstrate the robustness of onset primacy, suggesting that environmental demands or motivational factors would need to be sufficiently strong for people to switch to an adaptive attentional mode. PMID:27495326

  17. Kiloparsec Mass/Light Offsets in the Galaxy Pair-Lyα Emitter Lens System SDSS J1011+0143

    Science.gov (United States)

    Shu, Yiping; Bolton, Adam S.; Moustakas, Leonidas A.; Stern, Daniel; Dey, Arjun; Brownstein, Joel R.; Burles, Scott; Spinrad, Hyron

    2016-03-01

    We report the discovery of significant mass/light offsets in the strong gravitational lensing system SDSS J1011+0143. We use the high-resolution Hubble Space Telescope (HST) F555W- and F814W-band imaging and Sloan Digital Sky Survey (SDSS) spectroscopy of this system, which consists of a close galaxy pair with a projected separation of ≈ 4.2 {{kpc}} at zlens ˜ 0.331 lensing an Lyα emitter (LAE) at zsource = 2.701. Comparisons between the mass peaks inferred from lens models and light peaks from HST imaging data reveal significant spatial mass/light offsets as large as 1.72 ± 0.24 ± 0.34 kpc in both filter bands. Such large mass/light offsets, not seen in isolated field lens galaxies and relaxed galaxy groups, may be related to the interactions between the two lens galaxies. The detected mass/light offsets can potentially serve as an important test for the self-interacting dark matter model. However, other mechanisms such as dynamical friction on spatially differently distributed dark matter and stars could produce similar offsets. Detailed hydrodynamical simulations of galaxy-galaxy interactions with self-interacting dark matter could accurately quantify the effects of different mechanisms. The background LAE is found to contain three distinct star-forming knots with characteristic sizes from 116 to 438 pc. It highlights the power of strong gravitational lensing in probing the otherwise too faint and unresolved structures of distance objects below subkiloparsec or even 100 pc scales through its magnification effect. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. These observations are associated with program #10831.

  18. Supersymmetric heterotic string backgrounds

    NARCIS (Netherlands)

    Gran, U.; Papadopoulos, G.; Roest, D.; Cvetič, M.

    2007-01-01

    We present the main features of the solution of the gravitino and dilatino Killing spinor equations derived in hep-th/0510176 and hep-th/0703143 which have led to the classification of geometric types of all type I backgrounds. We then apply these results to the supersymmetric backgrounds of the het

  19. The Cosmic Microwave Background

    OpenAIRE

    Silk, Joseph

    2001-01-01

    This set of lectures provides an overview of the basic theory and phenomenology of the cosmic microwave background. Topics include a brief historical review; the physics of temperature and polarization fluctuations; acoustic oscillations of the primordial plasma; the space of inflationary cosmological models; current and potential constraints on these models from the microwave background; and constraints on inflation.

  20. Heavy metals in the products of deinking flotation of digital offset prints.

    Science.gov (United States)

    Barbaric-Mikocevic, Zeljka; Orescanin, Visnja; Bolanca, Zdenka; Lulic, Stipe; Rozic, Mirela

    2004-01-01

    This study was undertaken to investigate the suitability of applying the conventional method of chemical deinking flotation of digital offset prints and ecological implications of the disposal of digital offset prints, with special emphasis on the content of heavy metal cations. The EDXRF method was used to determine the concentrations of Pb, Zr, Sr, As, Co, Zn, Cu, Ni, Fe, Mn, Cr, V, Ti, Ca, and K cations in handsheet ashes after flotation as well as in ashes of foams separated from cellulose suspension in the flotation phase. The same method was applied to determine the concentrations of Pb, Cr, Mn, Fe, Ni, Cu, Zn, and Co in process water filtrates obtained from the cellulose suspension after flotation and in foam filtrates. Centrifuging and coagulation previously treated flotation process water, while foam filtrates were centrifuged. Concentrations of Pb, As, Sr, Zr, K, Ca, Ti, V, Cr, Mn, Fe, Cu, and Zn were determined in the sediments obtained by centrifuging process water. The trials were done with unprinted substrates without deinking chemicals, with unprinted substrates in the presence of deinking chemicals and with printed substrates in the presence of deinking chemicals. Cation analysis revealed that deinking chemicals facilitate release of cations from the substrate and their transition into process water. Concentrations of most cations in the flotation process water, in foam water as well as in the sediment of the process water of printed substrate flotation deinking were lower than those obtained by flotation of unprinted substrate suspension. Polymer particles of ElectroInk incompletely separated from cellulose fibers prevent release of cations from cellulose fibers into process water. Deinking chemicals do not affect release of cations from ElectroInk particles, so the substrate is the main source of increased concentration of cations in the water of digital offset print deinking. The major part of cations in process water is bound to the colloid

  1. Limitations on near-surface correction for multicomponent offset VSP

    Energy Technology Data Exchange (ETDEWEB)

    Macbeth, C.; Li, X.Y.; Horne, S. [British Geological Survey, Edinburgh (United Kingdom)

    1994-12-31

    Multicomponent data are degraded due to near-surface scattering and non-ideal or unexpected source behavior. These effects cannot be neglected when interpreting relative wavefield attributes derived from compressional and shear waves. They confuse analyses based on standard scalar procedures and a prima facia interpretation of the vector wavefield properties. Here, the authors highlight two unique polar matrix decompositions for near-surface correction in offset VSPs, consider their inherent mathematical constraints and how they impact on subsurface interpretation. The first method is applied to a four component subset of a six component field data from a configuration of three concentric rings and walkaway source positions forming offset VSPs in the Cymric field, California. The correction appears successful in automatically converting the wavefield into its ideal form, and the qSl polarizations scatter around N15{degree}E in agreement with the layer stripping of Winterstein and Meadows (1991).

  2. Modification of the aluminum for making offset printing plates

    Directory of Open Access Journals (Sweden)

    NENAD ILIC

    2000-12-01

    Full Text Available Aluminum as the base of offset printing plates should make good contact with wetting agents and the light sensitive layer and should be resistant to wear and cracking. In order to achieve this, the aluminum is roughened and eventually anodized. A thin, electrochemically deposited chromium layer is used as the non-printing element in bimetallic offset printing forms. Chromium shows excellent wettability and wear resistance. The possibility of chemical deposition of chromium on aluminum from an alkaline solution is examined in this paper. The presence of chromium was confirmed and measured by EDAX. A difference in the spectral reflection characteristic between chromium-treated and non-treated specimens was also detected. An influence of a chromium layer on an aluminum surface was examined by water drop spreading. Chromium-treated samples showed better wettability than non-treated samples, but they are less wettable than anodized samples.

  3. Histogram Equalization with Range Offset for Brightness Preserved Image Enhancement

    Directory of Open Access Journals (Sweden)

    Haidi Ibrahim

    2011-12-01

    Full Text Available In this paper, a simple modification to Global Histogram Equalization (GHE, a well known digital image enhancement method, has been proposed. This proposed method known as Histogram Equalization with Range Offset (HERO is divided into two stages. In its first stage, an intensity mapping function is constructed by using the cumulative density function of the input image, similar to GHE. Then, during the second stage, an offset for the intensity mapping function will be determined to maintain the mean brightness of the image, which is a crucial criterion for digital image enhancement in consumer electronic products. Comparison with some of the current histogram equalization based enhancement methods shows that HERO successfully preserves the mean brightness and give good enhancement to the image.

  4. A high performance frequency offset estimator for OFDM

    Institute of Scientific and Technical Information of China (English)

    WU Yun; LUO Han-wen; DING Ming; YAN Chong-guang

    2006-01-01

    This paper proposes a simple method to enlarge the estimation range of conventional carrier frequency offset (CFO)estimation methods based on correlations among the identical parts of the preamble. A novel preamble is designed, which is composed of one regular OFDM training block with even numbers of identical parts and one irregular OFDM training block with odd numbers of identical parts. The initial estimates obtained over the two training blocks are next exploited to jointly estimate the CFO. By elaborately selecting the numbers of identical parts for the two training blocks, the proposed CFO estimator can estimate frequency offset over tens of the subcarrier spacing. Simulation results showed that the proposed CFO estimator satisfies the estimate range requirement for the practical OFDM systems, while achieving a very good estimate performance.

  5. Greenhouse gas emission offsets: A global warming insurance policy

    International Nuclear Information System (INIS)

    While scientists work to define the nature and extent of potential climate change, policy makers debate the appropriateness of different responses. One voluntary initiative has pursued a possible response: greenhouse gas offsets. This article describes a program undertaken by The AES Corporation to attempt to offset CO2 emissions from cogeneration facilities run by the corporation. Independent investigations indicated that an extensive reforestation program might be a practical way to create sinks for CO2. This article describes some of the practical concerns of this project. It also describes efforts made to locate areas to carry out a reforestation program, groups worked with, and effort devoted to finding ways to quantify the success of any effort undertaken

  6. First-arrival Tomography Using the Double-square-root Equation Solver Stepping in Subsurface Offset

    KAUST Repository

    Serdyukov, A.S.

    2013-01-01

    Double-square-root (DSR) equation can be viewed as a Hamilton-Jacobi equation describing kinematics of downward data continuation in depth. It describes simultaneous propagation of source and receiver rays assuming that they are nowhere horizontal. Thus it is not suitable for describing diving waves. This equation can be rewritten in a new form when stepping is made in subsurface offset instead of depth. In this form it can be used for describing traveltimes of diving waves in prestack seismic data. This equation can be solved using WENO-RK numerical scheme. Prestack traveltimes (for multiple sources) can be computed in one run thus speeding up solution of the forward problem. We derive linearized version of this new DSR equation that can be used for tomographic inversion of first-arrival traveltimes. Here we used a ray-based tomographic inversion consisting of the following steps: get numerical solution of the offset DSR equation in the background velocity model, back trace DSR rays connecting receivers to sources, update velocity model using truncated SVD pseudoinverse. This approach was tested on a synthetic model generating diving waves.

  7. Velocity versus Offset (VVO Estimation Using Local Event Correlation and Its Application in Seismic Processing & Analysis

    Directory of Open Access Journals (Sweden)

    Supriyono

    2013-07-01

    Full Text Available Conventional velocity analysis is usually done in a relatively spare grid, for instance every half kilometers, during the processing of seismic data. It is very laborious work and very subjective. To deliver an accurate velocity picking, processing geophysicists must have a good understanding of geological background of area being analyzed and experiences. Velocity errors often occur during picking. Proper quality control and checking are a must. A good and reliable velocity field is very important in seismic processing for achieving high-quality seismic images as well as for delivering an accurate depth conversion. The new method presented here, was developed to correct velocity errors automatically by means of residual velocity correction, and to produce an offset-dependent RMS velocity field at the same time. The method is data driven, based on the normal move out equation (NMO and measuring the local even correlation between adjacent traces. The stacking velocity is derived simply by averaging the velocity field. The proposed method was tested on synthetic and real data examples with good result. The velocity field has certain characteristics related to hydrocarbon presence. Supriyono (2011 and 2012 developed a new DHI method using velocity gradient attributes by cross-plotting the velocity versus offset (VVO. The velocity gradient exhibits high anomalous values in the presence of gas.

  8. Validation of Maturity Offset in the Fels Longitudinal Study.

    Science.gov (United States)

    Malina, Robert M; Choh, Audrey C; Czerwinski, Stefan A; Chumlea, Wm Cameron

    2016-08-01

    Sex-specific equations for predicting maturity offset, time before or after peak height velocity (PHV), were evaluated in 63 girls and 74 boys from the Fels Longitudinal Study. Serially measured heights (0.1 cm), sitting heights (0.1 cm), weights (0.1 kg), and estimated leg lengths (0.1 cm) from 8 to 18 years were used. Predicted age at PHV (years) was calculated as the difference between chronological age (CA) and maturity offset. Actual age at PHV for each child was derived with a triple logistic model (Bock-Thissen-du Toit). Mean predicted maturity offset was negative and lowest at 8 years and increased linearly with increasing CA. Predicted ages at PHV increased linearly with CA from 8 to 18 years in girls and from 8 to 13 years in boys; predictions varied within relatively narrow limits from 12 to 15 years and then increased to 18 years in boys. Differences between predicted and actual ages at PHV among youth of contrasting maturity status were significant across the age range in both sexes. Dependence of predicted age at PHV upon CA at prediction and on actual age at PHV limits its utility as an indicator of maturity timing and in sport talent programs. PMID:26757350

  9. Tax-Optimal Step-Up and Imperfect Loss Offset

    Directory of Open Access Journals (Sweden)

    Markus Diller

    2012-05-01

    Full Text Available In the field of mergers and acquisitions, German and international tax law allow for several opportunities to step up a firm's assets, i.e., to revaluate the assets at fair market values. When a step-up is performed the taxpayer recognizes a taxable gain, but also obtains tax benefits in the form of higher future depreciation allowances associated with stepping up the tax base of the assets. This tax-planning problem is well known in taxation literature and can also be applied to firm valuation in the presence of taxation. However, the known models usually assume a perfect loss offset. If this assumption is abandoned, the depreciation allowances may lose value as they become tax effective at a later point in time, or even never if there are not enough cash flows to be offset against. This aspect is especiallyrelevant if future cash flows are assumed to be uncertain. This paper shows that a step-up may be disadvantageous or a firm overvalued if these aspects are not integrated into the basic calculus. Compared to the standard approach, assets should be stepped up only in a few cases and - under specific conditions - at a later point in time. Firm values may be considerably lower under imperfect loss offset.

  10. Improved SAR Image Coregistration Using Pixel-Offset Series

    KAUST Repository

    Wang, Teng

    2014-03-14

    Synthetic aperture radar (SAR) image coregistration is a key procedure before interferometric SAR (InSAR) time-series analysis can be started. However, many geophysical data sets suffer from severe decorrelation problems due to a variety of reasons, making precise coregistration a nontrivial task. Here, we present a new strategy that uses a pixel-offset series of detected subimage patches dominated by point-like targets (PTs) to improve SAR image coregistrations. First, all potentially coherent image pairs are coregistered in a conventional way. In this step, we propose a coregistration quality index for each image to rank its relative “significance” within the data set and to select a reference image for the SAR data set. Then, a pixel-offset series of detected PTs is made from amplitude maps to improve the geometrical mapping functions. Finally, all images are resampled depending on the pixel offsets calculated from the updated geometrical mapping functions. We used images from a rural region near the North Anatolian Fault in eastern Turkey to test the proposed method, and clear coregistration improvements were found based on amplitude stability. This enhanced the fact that the coregistration strategy should therefore lead to improved InSAR time-series analysis results.

  11. Cosmogenic Backgrounds to 0{\

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Feyzbakhsh, S; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Njoya, O; Nelson, R; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retière, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2015-01-01

    As neutrinoless double-beta decay experiments become more sensitive and intrinsic radioactivity in detector materials is reduced, previously minor contributions to the background must be understood and eliminated. With this in mind, cosmogenic backgrounds have been studied with the EXO-200 experiment. Using the EXO-200 TPC, the muon flux (through a flat horizontal surface) underground at the Waste Isolation Pilot Plant (WIPP) has been measured to be {\\Phi} = 4.07 $\\pm$ 0.14 (sys) $\\pm$ 0.03 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$, with a vertical intensity of $I_{v}$ = 2.97$^{+0.14}_{-0.13}$ (sys) $\\pm$ 0.02 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$ sr$^{-1}$. Simulations of muon-induced backgrounds identified several potential cosmogenic radionuclides, though only 137Xe is a significant background for the 136Xe 0{\

  12. A Robust Approach for Clock Offset Estimation in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Kim Jang-Sub

    2010-01-01

    Full Text Available The maximum likelihood estimators (MLEs for the clock phase offset assuming a two-way message exchange mechanism between the nodes of a wireless sensor network were recently derived assuming Gaussian and exponential network delays. However, the MLE performs poorly in the presence of non-Gaussian or nonexponential network delay distributions. Currently, there is a need to develop clock synchronization algorithms that are robust to the distribution of network delays. This paper proposes a clock offset estimator based on the composite particle filter (CPF to cope with the possible asymmetries and non-Gaussianity of the network delay distributions. Also, a variant of the CPF approach based on the bootstrap sampling (BS is shown to exhibit good performance in the presence of reduced number of observations. Computer simulations illustrate that the basic CPF and its BS-based variant present superior performance than MLE under general random network delay distributions such as asymmetric Gaussian, exponential, Gamma, Weibull as well as various mixtures.

  13. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  14. On Background Independence

    OpenAIRE

    Anderson, Edward

    2013-01-01

    This paper concerns what Background Independence itself is (as opposed to some particular physical theory that is background independent). The notions presented mostly arose from a layer-by-layer analysis of the facets of the Problem of Time in Quantum Gravity. Part of this coincides with two relational postulates which are thus identified as classical precursors of two of the facets of the Problem of Time. These are furthemore tied to the forms of each of the GR Hamiltonian and momentum cons...

  15. Estimates of Future Supply of International Greenhouse Gas Offsets: A Critical Review

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, Peter; Lazarus, Michael (Stockholm Environment Inst. (United States)), e-mail: mlaz@sei-us.org; Kelly, Alexia (World Resources Inst., (United States))

    2010-07-01

    This report reviews estimates of the projected availability (i.e., supply) of international offsets, evaluates the various methods used and outlines factors that should be incorporated into future analyses of international offset supply and quality. U.S. policymakers have relied on offsets from developing countries as a primary form of cost containment in proposed cap-and-trade legislation. These legislative proposals allow for emitters to use up to 1.5 billion tons CO{sub 2}e of offsets from developing countries to meet their annual compliance obligations. In this paper, we review estimates of the projected availability (i.e., supply) of international offsets, and evaluate the various methods used. We find that: (1) Estimates of supply of international offsets to global markets vary widely, with estimates differing by billions of tons CO{sub 2}e annually in 2020; (2) Despite the variation, existing studies suggest that by 2020 gross international offset supply will likely exceed U.S. demand for international offsets under current Congressional cap-and-trade designs; (3) Competition with governments and entities with emission reduction obligations (e.g. the EU), as well as with policies and measures undertaken by developing countries as part of their own mitigation contributions, could reduce the net offset supply available to U.S. entities; and (4) Several important offset program design and market factors that are central to future offset markets and credit issuance (e.g., sources of offset supply, program stringency and crediting methods, establishment of international governance and market structures) have yet to be systematically considered in offset supply assessments. This paper outlines factors that should be incorporated into future analyses of international offset supply and quality. 7 Such analyses could prove particularly germane as policy makers continue to deliberate on the role of international offsets, including whether and how to recognize credits

  16. A method for calculating minimum biodiversity offset multipliers accounting for time discounting, additionality and permanence

    OpenAIRE

    Laitila, Jussi; Moilanen, Atte; Pouzols, Federico M

    2014-01-01

    Biodiversity offsetting, which means compensation for ecological and environmental damage caused by development activity, has recently been gaining strong political support around the world. One common criticism levelled at offsets is that they exchange certain and almost immediate losses for uncertain future gains. In the case of restoration offsets, gains may be realized after a time delay of decades, and with considerable uncertainty. Here we focus on offset multipliers, which are ratios b...

  17. 76 FR 37030 - Financial Derivatives Transactions To Offset Interest Rate Risk; Investment and Deposit Activities

    Science.gov (United States)

    2011-06-24

    ... ADMINISTRATION 12 CFR Part 703 Financial Derivatives Transactions To Offset Interest Rate Risk; Investment and... name] Comments on Part 703 ANPR, Financial Derivatives Transactions to Offset Interest Rate Risk'' in... and sale of financial derivatives, provided it is for the purpose of offsetting interest rate...

  18. 75 FR 16493 - Agency Information Collection Activities: Distribution of Continued Dumping and Subsidy Offset to...

    Science.gov (United States)

    2010-04-01

    ... Continued Dumping and Subsidy Offset to Affected Domestic Producers (CDSOA) AGENCY: U.S. Customs and Border... Dumping and Subsidy Offset to Affected Domestic Procedures. This request for comment is being made... Continued Dumping and Subsidy Offset to Affected Domestic Producers (CDSOA). OMB Number: 1651-0086....

  19. Thermal inflation and the gravitational wave background

    International Nuclear Information System (INIS)

    We consider the impact of thermal inflation—a short, secondary period of inflation that can arise in supersymmetric scenarios—on the stochastic gravitational wave background. We show that while the primordial inflationary gravitational wave background is essentially unchanged at cosmic microwave background scales, it is massively diluted at solar system scales and would be unobservable by a Big Bang Observer (BBO) style experiment. Conversely, bubble collisions at the end of thermal inflation can generate a new stochastic background. We calculate the likely properties of the bubbles created during this phase transition, and show that the expected amplitude and frequency of this signal would fall within the BBO range

  20. Frequency-offset separated oscillatory fields: A demonstration of a new technique for a measurement of the helium n=2 triplet P fine structure

    Science.gov (United States)

    Fitzakerley, D. W.; Kato, K.; George, M. C.; Vutha, A. C.; Skinner, T. D. G.; Bezginov, N.; Hessels, E. A.

    2016-05-01

    We perform a proof-of-principle demonstration of the frequency-offset separated oscillatory field (FOSOF) technique. For the FOSOF technique, the two separated field have frequencies which are offset from each other, so that the relative phases of the fields varies linearly in time. This proof-of-principle demonstration measures the 23 P1 m = 1 to 23 P2 m = 1 transition in atomic helium and demonstrates the usefulness of the FOSOF technique for high-precision atomic measurements. Supported by NSERC, CRC.

  1. A NEW ALGORITHM FOR ELIMINATING PHASE-SHIFT ERROR IN PHASE SHIFTING INTERFEROMETRY

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The effect of phase-shift error in phase shifting interferometry is investigated. A new algorithm with two sets of 4 samples for eliminating phase-shift error is presented. The computer simulation and experiment result show that the phase-shift offset should be π when the algorithm is used, and this algorithm has gotten better result than the original 4-sample algorithm.

  2. A comparison of leg length and femoral offset discrepancies in hip resurfacing, large head metal-on- metal and conventional total hip replacement: a case series

    Directory of Open Access Journals (Sweden)

    Herman Katie A

    2011-12-01

    Full Text Available Abstract Background A discrepancy in leg length and femoral offset restoration is the leading cause of patient dissatisfaction in hip replacement surgery and has profound implications on patient quality of life. The aim of this study is to compare biomechanical hip reconstruction in hip resurfacing, large-diameter femoral head hip arthroplasty and conventional total hip replacement. Method Sixty patient's post-operative radiographs were reviewed; 20 patients had a hip resurfacing (HR, 20 patients had a Large Head Metal-on-metal (LHM hip replacement and 20 patients had a conventional small head Total Hip Replacement (THR. The leg length and femoral offset of the operated and unoperated hips were measured and compared. Results Hip resurfacing accurately restored hip biomechanics with no statistical difference in leg length (P = 0.07 or femoral offset (P = 0.95 between the operated and non-operative hips. Overall HR was superior for reducing femoral offset discrepancies where it had the smallest bilateral difference (-0.2%, P = 0.9. The traditional total hip replacement was least effective at restoring the hip anatomy. Conclusion The use of a larger-diameter femoral head in hip resurfacing does not fully account for the superior biomechanical restoration, as LHM did not restore femoral offset as accurately. We conclude that restoration of normal hip biomechanics is best achieved with hip resurfacing.

  3. Unitarity and singular backgrounds

    CERN Document Server

    Brouzakis, Nikos

    2013-01-01

    We compute the graviton Kaluza-Klein spectrum on a gravity-dilaton background with a naked singularity for all possible boundary conditions at the singularity which are consistent with unitary evolution. We apply methods from non-relativistic quantum mechanics with singular Schr\\"{o}dinger potentials. In general the spectrum contains a tachyon, a sign of instability. Only for a particular boundary condition at the singularity the spectrum is free of tachyons. In this case the lowest-lying graviton mode is massless. We argue that this result will also hold for other backgrounds with similar geometry near the curvature singularity. We complete our study with a brief discussion on radion perturbations and Higgs mechanism on this singular background.

  4. Exploring String Theory Backgrounds

    CERN Document Server

    Williams, B P

    2004-01-01

    This thesis examines phenomenological and theoretical questions by exploring string theoretic backgrounds. Part I focuses on cosmology. First we propose that the induced metric along a brane moving through a curved bulk may be interpreted as the cosmology of the brane universe, providing a resolution to the apparent cosmological singularity on the brane. We then look at various decay channels of the certain meta-stable de Sitter vacua and show that there exist NS5-brane meditated decays which are much faster than decays to decompactification. Part II discusses a new class of nongeometric vacua in string theory. These backgrounds may be described locally as T2 fibrations. By enlarging the monodromy group of the fiber to include perturbative stringy duality symmetries we are able to explicitly construct nongeometric backgrounds.

  5. Laser Frequency Stabilization and Control through Offset Sideband Locking to Optical Cavities

    Science.gov (United States)

    Thorpe, James I.; Livas, J.; Numata, K.

    2008-01-01

    We describe a class of techniques whereby a laser frequency can be stabilized to a fixed optical cavity resonance with an adjustable offset, providing a wide tuning range for the central frequency. These techniques require only minor modifications to the standard Pound-Drever-Hall locking techniques and have the advantage of not altering the intrinsic stability of the frequency reference. In a laboratory investigation the sideband techniques were found to perform equally well as the standard, non-tunable Pound-Drever-Hall technique, each providing more than four decades of frequency noise suppression over the free-running noise. An application of a tunable system as a pre-stabilization stage in a phase-lock loop is also presented with the combined system achieving a frequency noise suppression of nearly twelve orders of magnitude.

  6. An offset-fed 20/30 GHz dual-band circularly polarized reflectarray antenna

    DEFF Research Database (Denmark)

    Smith, Thomas Gunst; Vesterdal, Niels; Gothelf, Ulrich;

    2013-01-01

    A dual-frequency circularly polarized offset reflectarray antenna for Ka-band satellite communication is presented. The reflectarray is designed using the concentric dual split-loop element which enables full 360° phase adjustment simultaneously in two separate frequency bands. The elements have...... been optimized to suppress the cross-polar reflection. Thereafter, the element data is used for synthesis of the reflectarray layout and computation of the associated radiation patterns. The reflectarray is 400mm × 400mm and radiates LHCP at 19.95 GHz and RHCP at 29.75 GHz. Aperture efficiencies of 58......% and 60% are obtained at these frequencies, and the cross-polarization is more than 25 dB below peak gain....

  7. Effect of random surface errors on radiation characteristics of the side-fed offset Cassegrain antenna

    Institute of Scientific and Technical Information of China (English)

    LIU Shao-dong; JIAO Yong-chang; ZHANG Fu-shun

    2006-01-01

    In this paper the average power pattern of the side-fed offset Cassegrain (SFOC) dual reflector antenna is analyzed,and the effect of the random surface error on radiation characteristics of the antenna is introduced.Here,the random surface error is defined as the error of the standard reflector in its normal direction and the errors in a small zone of the reflector are considered as equal.We also assume that the phase error on the aperture led by the random surface error obeys a Gaussian distribution with zero mean,under which the expression of the average power pattern is deduced.Finally,the data related to the radiation characteristics of the antenna are calculated and the corresponding curves are presented.The obtained results can be used for the user to determine the manufacturing accuracy of the reflector of the SFOC antennas.

  8. Offsets and conservation of the species of the EU habitats and birds directives.

    Science.gov (United States)

    Regnery, Baptiste; Couvet, Denis; Kerbiriou, Christian

    2013-12-01

    Biodiversity offsets are intended to achieve no net loss of biodiversity due to economic and human development. A variety of biodiversity components are addressed by offset policies. It is required that loss of protected species due to development be offset under the EU Habitats and Birds Directives in Europe. We call this type of offset a species-equality offset because the offset pertains to the same species affected by the development project. Whether species equality can be achieved by offset design is unknown. We addressed this gap by reviewing derogation files (i.e., specific files that describe mitigation measures to ensure no net loss under the EU Habitats and Birds Directives) from 85 development projects in France (2009-2010). We collected information on type of effect (reversible vs. irreversible) and characteristics of affected and offset sites (i.e., types of species, total area). We analyzed how the type of effect and the affected-site characteristics influenced the occurrence of offset measures. The proportion of species targeted by offset measures (i.e., offset species) increased with the irreversibility of the effect of development and the conservation status of the species affected by development (i.e., affected species). Not all effects on endangered species (International Union for Conservation of Nature Red List) were offset; on average, 82% of affected species would be offset. Twenty-six percent of species of least concern were offset species. Thirty-five percent of development projects considered all affected species in their offset measures. Species richness was much lower in offset sites than in developed sites even after offset proposals. For developed areas where species richness was relatively high before development, species richness at offset sites was 5-10 times lower. The species-equality principle appears to have been applied only partially in offset policies, as in the EU directives. We suggest the application of this principle

  9. Offsets and conservation of the species of the EU habitats and birds directives.

    Science.gov (United States)

    Regnery, Baptiste; Couvet, Denis; Kerbiriou, Christian

    2013-12-01

    Biodiversity offsets are intended to achieve no net loss of biodiversity due to economic and human development. A variety of biodiversity components are addressed by offset policies. It is required that loss of protected species due to development be offset under the EU Habitats and Birds Directives in Europe. We call this type of offset a species-equality offset because the offset pertains to the same species affected by the development project. Whether species equality can be achieved by offset design is unknown. We addressed this gap by reviewing derogation files (i.e., specific files that describe mitigation measures to ensure no net loss under the EU Habitats and Birds Directives) from 85 development projects in France (2009-2010). We collected information on type of effect (reversible vs. irreversible) and characteristics of affected and offset sites (i.e., types of species, total area). We analyzed how the type of effect and the affected-site characteristics influenced the occurrence of offset measures. The proportion of species targeted by offset measures (i.e., offset species) increased with the irreversibility of the effect of development and the conservation status of the species affected by development (i.e., affected species). Not all effects on endangered species (International Union for Conservation of Nature Red List) were offset; on average, 82% of affected species would be offset. Twenty-six percent of species of least concern were offset species. Thirty-five percent of development projects considered all affected species in their offset measures. Species richness was much lower in offset sites than in developed sites even after offset proposals. For developed areas where species richness was relatively high before development, species richness at offset sites was 5-10 times lower. The species-equality principle appears to have been applied only partially in offset policies, as in the EU directives. We suggest the application of this principle

  10. Fracture characterization from near-offset VSP inversion

    Energy Technology Data Exchange (ETDEWEB)

    Horne, S. [British Geological Survey, Edinburgh (United Kingdom)]|[Univ. of Edinburgh (United Kingdom). Dept. of Geology and Geophysics; MacBeth, C. [British Geological Survey, Edinburgh (United Kingdom); Queen, J.; Rizer, W.; Cox, V. [Conoco, Inc., Ponca City, OK (United States)

    1997-01-01

    A global optimization method incorporating a ray-tracing scheme is used to invert observations of shear-wave splitting from two near-offset VSPs recorded at the Conoco Borehole Test Facility, Kay County, Oklahoma. Inversion results suggest that the seismic anisotropy is due to a non-vertical fracture system. This interpretation is constrained by the VSP acquisition geometry for which two sources are employed along near diametrically opposite azimuths about the well heads. A correlation is noted between the time-delay variations between the fast and slow split shear waves and the sandstone formations.

  11. Zero-Offset VSP in the COSC-1 borehole

    Science.gov (United States)

    Krauß, Felix; Simon, Helge; Giese, Rüdiger; Buske, Stefan; Hedin, Peter; Juhlin, Christopher; Lorenz, Henning

    2015-04-01

    As support for the COSC drilling project (Collisional Orogeny in the Scandinavian Caledonides), an extensive seismic survey took place during September and October 2014 in and around the newly drilled borehole COSC-1. The main aim of the COSC project is to better understand orogenic processes in past and recently active mountain belts. For this an approx. 2.5 km deep borehole, with nearly 100% core recovery, was drilled in the Scandinavian Caledonides, close to the town of Åre in western Jämtland/Sweden. The seismic survey consisted of a high resolution zero-offset VSP (vertical seismic profiling) and a multi-azimuthal walkaway VSP experiment with receivers at the surface and in the borehole. For the zero-offset VSP (ZVSP) a hydraulic hammer source (VIBSIST 3000) was used and activated over a period of 20 seconds as a sequence of impacts with increasing hit frequency. For each source point, 25 seconds of data were recorded. The wavefield was recorded in the borehole by 15 three-component receivers using a Sercel Slimwave geophone chain with an inter-tool spacing of 10 meters. The ZVSP was designed to result in a geophone spacing of 2 meters over the whole borehole length. The source was about 30 meters away from the borehole and thus, provides a poor geometry to rotate 3C-data in greater depths. For this reason, a check shot position was defined in about 1.9 km distance to the borehole. With this offset shots, it is possible to rotate the components of the 3C receivers and to concentrate the S-wave energy on one component and thus, increase the signal-to-noise ratio of S-wave events. This offset source point was activated periodically for certain depth positions of the geophone chain. The stacked ZVSP-data show a high signal-to-noise ratio and good data quality. Frequencies up to 150 Hz were recorded. On the vertical component, clear direct P-wave arrivals are visible. Several P-wave reflections occur below 1600 meters depth. After rotating the components

  12. Frequency comb offset dynamics of SESAM modelocked thin disk lasers

    OpenAIRE

    Emaury, Florian; Diebold, Andreas; Klenner, Alexander; Clara J. Saraceno; Schilt, Stéphane; Südmeyer, Thomas; Keller, Ursula

    2015-01-01

    We present a detailed study of the carrier-envelope offset (CEO) frequency dynamics of SESAM modelocked thin disk lasers (TDLs) pumped by kW-class highly transverse multimode pump diodes with a typical M2 value of 200-300, and give guidelines for future frequency stabilization of multi-100-W oscillators. We demonstrate CEO frequency detection with > 30 dB signal-to-noise ratio with a resolution bandwidth of 100 kHz from a SESAM modelocked Yb:YAG TDL delivering 140 W average output power with ...

  13. Timing and frequency offset estimation in the uplink OFDMA

    DEFF Research Database (Denmark)

    Nguyen, Huan Cong; Carvalho, Elisabeth De; Prasad, Ramjee

    2006-01-01

    in the downlink, it is more challenging in the uplink as users must be aligned in time and frequency to maintain the orthogonality of the subcarriers. This paper proposes a novel method to estimate jointly timing and frequency offset for multi-user in the uplink OFDMA. The scheme is compatible with the ranging......Based on Orthogonal Frequency Division Multiplexing (OFDM), Orthogonal Frequency Division Multiple Access (OFDMA) has emerged as one of the prime multiple access schemes for broadband wireless networks, e.g. the IEEE 802.16 wireless MAN standard. While OFDMA is relatively simple to implement...

  14. Life cycle assessment of offset printed matter with EDIP97

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred; Hansen, Morten Søes; Hauschild, Michael Zwicky

    2009-01-01

    warming, acidification and nutrient enrichment. Ecotoxicity and human toxicity, which are related to emissions of chemicals etc., are only included to a limited degree or not at all. In this paper we include the impacts from chemicals emitted during the life cycle of sheet fed offset printed matter....... This is done by making use of some of the newest knowledge about emissions from the production at the printing industry combined with knowledge about the composition of the printing materials used. In cases with available data also upstream emissions from the production of printing materials are included...

  15. Luminosity dilution due to random offset beam-beam interaction

    International Nuclear Information System (INIS)

    We consider beam-beam interaction in a collider in the case when the beams randomly displace around the equilibrium orbit at the interaction point. Due to the random part of the interaction, particles diffuse over the betatron amplitude causing an emittance growth of the beam. A Fokker-Planck equation is derived in which a diffusion coefficient is related with the spectral density of the noise. Estimations for the Superconducting Super Collider parameters give a tolerable level of the high-frequency beam offset at the interaction point. 2 refs

  16. Interference of Dark Matter Solitons and Galactic Offsets

    CERN Document Server

    Paredes, Angel

    2015-01-01

    By performing numerical simulations, we discuss the collisional dynamics of stable solitary waves in the Schrodinger-Poisson equation. In the framework of a model in which part or all of dark matter is a Bose-Einstein condensate of ultralight axions, we show that these dynamics can naturally account for the relative displacement between dark and ordinary matter in a galactic cluster, whose recent observation is the first empirical evidence of dark matter interactions beyond gravity. We argue that future observations might bear out or falsify this coherent wave interpretation of dark matter offsets.

  17. Efficient Timing and Frequency Offset Estimation Scheme for OFDM Systems

    Institute of Scientific and Technical Information of China (English)

    GUO Yi; GE Jianhua; LIU Gang; ZHANG Wujun

    2009-01-01

    A new training symbol weighted by pseudo-noise(PN) sequence is designed and an efficient timing and fre quency offset estimation scheme for orthogonal frequency division multiplcxing(OFDM)systems is proposed.The timing synchronization is accomplished by using the piecewise symmetric conjugate of the primitive training symbol and the good autocorrelation of PN weighted factor.The frequency synchronization is finished by utilizing the training symbol whose PN weighted factor is removed after the timing synchronization.Compared with conventional schemes,the proposed scheme can achieve a smaller mean square error and provide a wider frequency acquisition range.

  18. Enhanced Heat Exchanger with Offset Spine Fin Design

    OpenAIRE

    Kempiak, Michael; Junge, Brent

    2014-01-01

    An Offset Spine Fin Spine (segmented) fin coils have been used in certain applications as a result of their effective use of coil material. One can improve coil heat transfer performance by adding more fins per inch (FPI). This comes at the expense of air side pressure drop, which requires more fan energy to achieve the same air flow. When this type of fin is used in an evaporator, there is a secondary penalty associated with the fan heat that must be removed by the refrigeration system. Also...

  19. Background characterization for the GERDA experiment

    International Nuclear Information System (INIS)

    The GERmanium Detector Array (Gerda) experiment at the LNGS laboratory of INFN searches for the neutrinoless double beta (0νββ) decay of 76Ge. A discovery of this decay can greatly advance our knowledge on the nature and properties of neutrinos. The current best limit on the half-life of 76Ge 0νββ decay is 1.9 . 1025 years (90% C.L.). In order to increase the sensitivity on the half-life with respect to past experiments, the background rate in the energy region of interest (ROI) around Qββ = 2039 keV has been reduced by a factor 10. Gerda started data-taking with the full set of Phase I detectors in November 2011. Identification of the background in the first phase of the experiment is of major importance to further mitigate the background for Gerda Phase II. An analysis of the Phase I data resulted in a good understanding of the individual components in the Gerda background spectrum. The background components in the ROI have been identified to be mainly due to β- and γ-induced events originating from 214Bi (238U-series), 208Tl (232Th-series), 42K (progeny of 42Ar) and α-induced events coming from isotopes in the 226Ra decay chain. A background decomposition in the ROI will be presented, with a special emphasis on the contribution from α-induced events.

  20. Opportunities and Challenges for Terrestrial Carbon Offsetting and Marketing, with Some Implications for Forestry in the UK

    Directory of Open Access Journals (Sweden)

    Maria Nijnik

    2010-12-01

    Full Text Available Background and Purpose: Climate change and its mitigation have become increasingly high profile issues since the late 1990s, with the potential of forestry in carbon sequestration a particular focus. The purpose of this paper is to outline the importance of socio-economic considerations in this area. Opportunities for forestry to sequester carbon and the role of terrestrial carbon uptake credits in climate change negotiations are addressed, together with the feasibility of bringing terrestrial carbon offsets into the regulatory emission trading scheme. The paper discusses whether or not significant carbon offsetting and trading will occur on a large scale in the UK or internationally. Material and Methods: The paper reviews the literature on the socio-economic aspects of climate change mitigation via forestry (including the authors’ research on this topic to assess the potential for carbon offsetting and trading, and the likely scale of action. Results and Conclusion: We conclude that the development of appropriate socio-economic framework conditions (e.g. policies, tenure rights, including forest carbon ownership, and markets and incentives for creating and trading terrestrial carbon credits are important in mitigating climate change through forestry projects, and we make suggestions for future research that would be required to support such developments.

  1. Berkeley Low Background Facility

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K. J.; Norman, E. B. [Department of Nuclear Engineering, University of California-Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, CA 94720 (United States); Smith, A. R.; Poon, A. W. P.; Chan, Y. D. [Nuclear Science Division, Lawrence Berkeley National Laboratory, CA 94720 (United States); Lesko, K. T. [Physics Division, Lawrence Berkeley National Laboratory, CA 94720 (United States)

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  2. Backgrounded but not peripheral

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    -cultural construction of identity, and, as a matter of fact, that their role might be quite important. I argue that the DDAs are backgrounded but not peripheral, i.e. marginal or insignificant. And I introduce the notion of “contextualization cue” in this argument (Levinson, 2003a, Gumperz, 1992)....

  3. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

  4. China: Background Notes Series.

    Science.gov (United States)

    Reams, Joanne Reppert

    Concise background information on the People's Republic of China is provided. The publication begins with a profile of the country, outlining the people, geography, economy, and membership in international organizations. The bulk of the document then discusses in more detail China's people, geography, history, government, education, economy, and…

  5. Local microwave background radiation

    OpenAIRE

    Soares, Domingos

    2006-01-01

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  6. Offset Active Galactic Nuclei as Tracers of Galaxy Mergers and Supermassive Black Hole Growth

    CERN Document Server

    Comerford, Julia M

    2014-01-01

    Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search for offset AGNs in the Sloan Digital Sky Survey, by selecting AGN emission lines that exhibit statistically significant line-of-sight velocity offsets relative to systemic. From a parent sample of 18314 Type 2 AGNs at z<0.21, we identify 351 offset AGN candidates with velocity offsets of 50 km/s < |v| < 410 km/s. When we account for projection effects in the observed velocities, we estimate that 4% - 8% of AGNs are offset AGNs. We designed our selection criteria to bypass velocity offsets produced by rotating gas disks, AGN outflows, and gravitational recoil of supermassive black holes, but follow-up observations are still required to confirm our candidates as offset AGNs. We find that the fraction of AGNs that are offset candidates increases with AGN bolometric l...

  7. Biodiversity Offsets: Two New Zealand Case Studies and an Assessment Framework

    Science.gov (United States)

    Norton, David A.

    2009-04-01

    Biodiversity offsets are increasingly being used for securing biodiversity conservation outcomes as part of sustainable economic development to compensate for the residual unavoidable impacts of projects. Two recent New Zealand examples of biodiversity offsets are reviewed—while both are positive for biodiversity conservation, the process by which they were developed and approved was based more on the precautionary principal than on any formal framework. Based on this review and the broader offset literature, an environmental framework for developing and approving biodiversity offsets, comprising six principles, is outlined: (1) biodiversity offsets should only be used as part of an hierarchy of actions that first seeks to avoid impacts and then minimizes the impacts that do occur; (2) a guarantee is provided that the offset proposed will occur; (3) biodiversity offsets are inappropriate for certain ecosystem (or habitat) types because of their rarity or the presence of threatened species within them; (4) offsets most often involve the creation of new habitat, but can include protection of existing habitat where there is currently no protection; (5) a clear currency is required that allows transparent quantification of values to be lost and gained in order to ensure ecological equivalency between cleared and offset areas; (6) offsets must take into account both the uncertainty involved in obtaining the desired outcome for the offset area and the time-lag that is involved in reaching that point.

  8. A Computer Simulation of the System-Wide Effects of Parallel-Offset Route Maneuvers

    Science.gov (United States)

    Lauderdale, Todd A.; Santiago, Confesor; Pankok, Carl

    2010-01-01

    Most aircraft managed by air-traffic controllers in the National Airspace System are capable of flying parallel-offset routes. This paper presents the results of two related studies on the effects of increased use of offset routes as a conflict resolution maneuver. The first study analyzes offset routes in the context of all standard resolution types which air-traffic controllers currently use. This study shows that by utilizing parallel-offset route maneuvers, significant system-wide savings in delay due to conflict resolution of up to 30% are possible. It also shows that most offset resolutions replace horizontal-vectoring resolutions. The second study builds on the results of the first and directly compares offset resolutions and standard horizontal-vectoring maneuvers to determine that in-trail conflicts are often more efficiently resolved by offset maneuvers.

  9. Using offsets to mitigate environmental impacts of major projects: A stakeholder analysis.

    Science.gov (United States)

    Martin, Nigel; Evans, Megan; Rice, John; Lodhia, Sumit; Gibbons, Philip

    2016-09-01

    Global patterns of development suggest that as more projects are initiated, business will need to find acceptable measures to conserve biodiversity. The application of environmental offsets allows firms to combine their economic interests with the environment and society. This article presents the results of a multi-stakeholder analysis related to the design of offsets principles, policies, and regulatory processes, using a large infrastructure projects context. The results indicate that business was primarily interested in using direct offsets and other compensatory measures, known internationally as indirect offsets, to acquit their environmental management obligations. In contrast, the environmental sector argued that highly principled and scientifically robust offsets programs should be implemented and maintained for enduring environmental protection. Stakeholder consensus stressed the importance of offsets registers with commensurate monitoring and enforcement. Our findings provide instructive insights into the countervailing views of offsets policy stakeholders.

  10. Using offsets to mitigate environmental impacts of major projects: A stakeholder analysis.

    Science.gov (United States)

    Martin, Nigel; Evans, Megan; Rice, John; Lodhia, Sumit; Gibbons, Philip

    2016-09-01

    Global patterns of development suggest that as more projects are initiated, business will need to find acceptable measures to conserve biodiversity. The application of environmental offsets allows firms to combine their economic interests with the environment and society. This article presents the results of a multi-stakeholder analysis related to the design of offsets principles, policies, and regulatory processes, using a large infrastructure projects context. The results indicate that business was primarily interested in using direct offsets and other compensatory measures, known internationally as indirect offsets, to acquit their environmental management obligations. In contrast, the environmental sector argued that highly principled and scientifically robust offsets programs should be implemented and maintained for enduring environmental protection. Stakeholder consensus stressed the importance of offsets registers with commensurate monitoring and enforcement. Our findings provide instructive insights into the countervailing views of offsets policy stakeholders. PMID:27173891

  11. Offsetting the impacts of mining to achieve no net loss of native vegetation.

    Science.gov (United States)

    Sonter, L J; Barrett, D J; Soares-Filho, B S

    2014-08-01

    Offsets are a novel conservation tool, yet using them to achieve no net loss of biodiversity is challenging. This is especially true when using conservation offsets (i.e., protected areas) because achieving no net loss requires avoiding equivalent loss. Our objective was to determine if offsetting the impacts of mining achieves no net loss of native vegetation in Brazil's largest iron mining region. We used a land-use change model to simulate deforestation by mining to 2020; developed a model to allocate conservation offsets to the landscape under 3 scenarios (baseline, no new offsets; current practice, like-for-like [by vegetation type] conservation offsetting near the impact site; and threat scenario, like-for-like conservation offsetting of highly threatened vegetation); and simulated nonmining deforestation to 2020 for each scenario to quantify avoided deforestation achieved with offsets. Mines cleared 3570 ha of native vegetation by 2020. Under a 1:4 offset ratio, mining companies would be required to conserve >14,200 ha of native vegetation, doubling the current extent of protected areas in the region. Allocating offsets under current practice avoided deforestation equivalent to 3% of that caused by mining, whereas allocating under the threat scenario avoided 9%. Current practice failed to achieve no net loss because offsets did not conserve threatened vegetation. Explicit allocation of offsets to threatened vegetation also failed because the most threatened vegetation was widely dispersed across the landscape, making conservation logistically difficult. To achieve no net loss with conservation offsets requires information on regional deforestation trajectories and the distribution of threatened vegetation. However, in some regions achieving no net loss through conservation may be impossible. In these cases, other offsetting activities, such as revegetation, will be required. PMID:24673499

  12. Neoclassical offset toroidal velocity and auxiliary ion heating in tokamaks

    Science.gov (United States)

    Lazzaro, E.

    2016-05-01

    In conditions of ideal axisymmetry, for a magnetized plasma in a generic bounded domain, necessarily toroidal, the uniform absorption of external energy (e.g., RF or any isotropic auxiliary heating) cannot give rise to net forces or torques. Experimental evidence on contemporary tokamaks shows that the near central absorption of RF heating power (ICH and ECH) and current drive in presence of MHD activity drives a bulk plasma rotation in the co- I p direction, opposite to the initial one. Also the appearance of classical or neoclassical tearing modes provides a nonlinear magnetic braking that tends to clamp the rotation profile at the q-rational surfaces. The physical origin of the torque associated with P RF absorption could be due the effects of asymmetry in the equilibrium configuration or in power deposition, but here we point out also an effect of the response of the so-called neoclassical offset velocity to the power dependent heat flow increment. The neoclassical toroidal viscosity due to internal magnetic kink or tearing modes tends to relax the plasma rotation to this asymptotic speed, which in absence of auxiliary heating is of the order of the ion diamagnetic velocity. It can be shown by kinetic and fluid calculations, that the absorption of auxiliary power by ions modifies this offset proportionally to the injected power thereby forcing the plasma rotation in a direction opposite to the initial, to large values. The problem is discussed in the frame of the theoretical models of neoclassical toroidal viscosity.

  13. Optical-radio positional offsets for active galactic nuclei

    CERN Document Server

    Orosz, G

    2013-01-01

    Context. It will soon become possible to directly link the most accurate radio reference frame with the Gaia optical reference frame using many common extragalactic objects. It is important to know the level of coincidence between the radio and optical positions of compact active galactic nuclei (AGN). Aims. Using the best catalogues available at present, we investigate how many AGN with significantly large optical-radio positional offsets exist as well as the possible causes of these offsets. Methods. We performed a case study by finding optical counterparts to the International Celestial Reference Frame (ICRF2) radio sources in the Sloan Digital Sky Survey (SDSS) Data Release 9 (DR9). The ICRF2 catalogue was used as a reference because the radio positions determined by Very Long Baseline Interferometry (VLBI) observations are about two orders of magnitude more accurate than the optical positions. Results. We find 1297 objects in common for ICRF2 and SDSS DR9. Statistical analysis of the optical-radio differ...

  14. Willingness to Pay of Air Passengers for Carbon-Offset

    Directory of Open Access Journals (Sweden)

    Rong-Chang Jou

    2015-03-01

    Full Text Available An important source of anthropogenic greenhouse gas (GHG emissions is the air transport sector, which accounts for approximately 2% of global GHG emissions. Therefore, reducing GHG emissions from aircrafts has become a major challenge for transportation authorities worldwide. In recent years, much research has focused on tax ideas related to the CO2 emissions produced by air transport, such as the voluntary carbon offset (VCO. This study investigates the willingness of economy class air passengers to pay to compensate for the CO2 emissions produced during their journeys from Taiwan to Hong Kong. Together with the Spike model, a framework known as the contingent valuation (CV method offers a way to investigate how much the air passenger would be willing to pay to offset a journey’s airplane-generated CO2 emissions. The Spike model was applied to address the problem of zero willingness to pay (WTP. The results obtained in this study are consistent with the results found in previous studies and therefore can provide valuable insights into pricing strategies for airlines.

  15. Tidally Induced Offset Disks in Magellanic Spiral Galaxies

    Science.gov (United States)

    Pardy, Stephen A.; D'Onghia, Elena; Athanassoula, E.; Wilcots, Eric M.; Sheth, Kartik

    2016-08-01

    Magellanic spiral galaxies are a class of one-armed systems that often exhibit an offset stellar bar and are rarely found around massive spiral galaxies. Using a set of N-body and hydrodynamic simulations, we consider a dwarf-dwarf galaxy interaction as the driving mechanism for the formation of this peculiar class of systems. We investigate here the relation between the dynamical, stellar, and gaseous disk center and the bar. In all our simulations the bar center always coincides with the dynamical center, while the stellar disk becomes highly asymmetric during the encounter, causing the photometric center of the Magellanic galaxy disk to become mismatched with both the bar and the dynamical center. The disk asymmetries persist for almost 2 Gyr, the time that it takes for the disk to be recentered with the bar, and well after the companion has passed. This explains the nature of the offset bar found in many Magellanic-type galaxies, including the Large Magellanic Cloud (LMC) and NGC 3906. In particular, these results, once applied to the LMC, suggest that the dynamical center should reside in the bar center instead of the H i center as previously assumed, pointing to a variation in the current estimate of the north component of the LMC proper motion.

  16. Spatially offset Raman spectroscopy (SORS) for liquid screening

    Science.gov (United States)

    Loeffen, Paul W.; Maskall, Guy; Bonthron, Stuart; Bloomfield, Matthew; Tombling, Craig; Matousek, Pavel

    2011-11-01

    Recently, Spatially Offset Raman Spectroscopy (SORS) has been discussed as a novel method for the screening of liquids, aerosols and gels (LAGs) at airports and for other security applications. SORS is an optical spectroscopic method which enables the precise chemical identification of substances from a reference list and, due to the rich spectral information, has an inherently high probability of detection and low false alarm rate. The method is generally capable of screening substances inside non-metallic containers such as plastic and glass bottles. SORS is typically successful through opaque plastic and coloured glass, which are often challenging for conventional backscatter Raman spectroscopy. SORS is performed in just a few seconds by shining a laser light onto the container and then measuring the Raman signal at the excitation point but also at one or more offset positions. Each measurement has different relative orthogonal contributions from the container and contents Raman spectra, so that, with no prior knowledge, the pure Raman spectra of both the container and contents can be extracted - either by scaled subtraction or via multivariate statistical methods in an automated process. In this paper, the latest results will be described from a prototype SORS device designed for aviation security and the advantages and limitations of SORS will be discussed.

  17. Determination of band offsets in strained-Si heterolayers

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, C.K.; Samanta, S.K.; Chatterjee, S.; Dalapati, G.K.; Bhattacharya, S.; Armstrong, B.M.; Gamble, H.S.; McCarthy, J.; Perova, T.S.; Moore, R.A

    2004-09-01

    Strained-Si/SiGe/Si structures are of increasing importance for microelectronic applications. A fully relaxed-SiGe buffer layer is required for growing strained-Si for applications towards high performance field effect transistors (FETs) having strained-Si as the channel. Preparation of epitaxial strained-Si layers on relaxed-SiGe (001) heterostructures using low pressure chemical vapor deposition (LPCVD) is reported. Gas source molecular beam epitaxy (GSMBE) grown strained-Si films are used to compare with LPCVD strained-Si films. Characterization of the strained-Si layers has been performed using AFM, TEM and Raman spectroscopy. Conduction and valence band offsets of strained-Si on relaxed-SiGe heterostructures have been extracted from measured capacitance-voltage (C-V) profiling of MOS capacitors fabricated on strained-Si using SiO{sub 2} as the dielectric. Extracted experimental values of the valence and conduction band offsets are in good agreement with theoretical predictions.

  18. Tidally-Induced Offset Disks in Magellanic Spiral Galaxies

    CERN Document Server

    Pardy, Stephen A; Athanassoula, E; Wilcots, Eric M; Sheth, Kartik

    2016-01-01

    Magellanic spiral galaxies are a class of one-armed systems that often exhibit an offset stellar bar, and are rarely found around massive spiral galaxies. Using a set of N-body and hydrodynamic simulations we consider a dwarf-dwarf galaxy interaction as the driving mechanism for the formation of this peculiar class of systems. We investigate here the relation between the dynamical, stellar and gaseous disk center and the bar. In all our simulations the bar center always coincides with the dynamical center, while the stellar disk becomes highly asymmetric during the encounter causing the photometric center of the Magellanic galaxy disk to become mismatched with both the bar and the dynamical center. The disk asymmetries persist for almost 2 Gyrs, the time that it takes for the disk to be re-centered with the bar, and well after the companion has passed. This explains the nature of the offset bar found in many Magellanic-type galaxies, including the Large Magellanic Cloud (LMC) and NGC 3906. In particular, thes...

  19. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  20. Sri Lanka; Background Papers

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This Background Paper on Sri Lanka provides information on the economic developments during 1992–95. Developments in the domestic and external sectors are discussed. The deficiencies of the official consumer price index that resulted in a substantial understatement of inflation performance in 1994 and alternative estimates of underlying inflation are described. The structural rigidities in the labor market that perpetuate high unemployment and limit job growth are also described. The paper ...

  1. Background, phenomenology, and motivation

    International Nuclear Information System (INIS)

    The authors discuss the background to the kinetics of adsorption and desorption after an elementary introduction to the problem of chemisorption in two limiting cases. Other topics discussed include the thermodynamics of adsorption, reaction mechanisms outside surfaces, and a case history of catalytic hydrogenation of carbon monoxide. Figures show the potential energy barrier as a function of an appropriate reaction coordinate, and bonding of carbon monoxide to platinum metal

  2. Australia; Background Material

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This paper describes the developments in the Australian labor market during the 1990s. In 1994, a number of new labor market programs were launched, directed especially at the long-term unemployed, and a further step was taken in the evolutionary reform of the industrial relations system. The paper reviews developments in employment, wages, and productivity in Australia that formed the background to these policy initiatives. It also examines the conduct of fiscal policy at the Commonwealth an...

  3. Some background about satellites

    Science.gov (United States)

    Burns, Joseph A.

    1986-01-01

    Four tables of planetary and satellite data are presented which list satellite discoveries, planetary parameters, satellite orbits, and satellite physical properties respectively. A scheme for classifying the satellites is provided and it is noted that most known moons fall into three general classes: regular satellites, collisional shards, and irregular satellites. Satellite processes are outlined with attention given to origins, dynamical and thermal evolution, surface processes, and composition and cratering. Background material is provided for each family of satellites.

  4. Methodology to include a correction for offset in the calibration of a Diode-based 2D verification device; Metodologia para incluir una correccion por offset en la calibracion de un dispositivo de verificacion 2D basado en diodos

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Ros, J. C.; Pamos Urena, M.; Jerez Sainz, M.; Lobato Munoz, M.; Jodar Lopez, C. A.; Ruiz Lopez, M. a.; Carrasco Rodriguez, J. L.

    2013-07-01

    We propose a methodology to correct doses of device verification 2D MapChek2 planes by offset. This methodology provides an array of correction by Offset applied to the calibration per dose due to the Offset of the diode Central as well as the correction of the Offset of each diode on each acquisition. (Author)

  5. Background and introduction

    DEFF Research Database (Denmark)

    Jensen, Per Anker; van der Voordt, Theo; Coenen, Christian

    2012-01-01

    Purpose: To explain the purpose and background of this book and introduce the three basic perspectives behind the research presented as well as the structure and editing process of the book. Methodology: The editors shared and discussed individual contributions to this chapter, based on their own...... in scope between FM and CREM is that CREM has its focus on real estate as physical and economical assets utilized by an organisation, while FM has a wider service focus. The difference in scope between FM and CREM on one side and B2B marketing on the other is that FM and CREM are related to organisations...

  6. Family Background and Entrepreneurship

    DEFF Research Database (Denmark)

    Lindquist, Matthew J.; Sol, Joeri; Van Praag, Mirjam;

    Vast amounts of money are currently being spent on policies aimed at promoting entrepreneurship. The success of such policies, however, rests in part on the assumption that individuals are not ‘born entrepreneurs’. In this paper, we assess the importance of family background and neighborhood...... effects as determinants of entrepreneurship. We start by estimating sibling correlations in entrepreneurship. We find that between 20 and 50 percent of the variance in different entrepreneurial outcomes is explained by factors that siblings share. The average is 28 percent. Allowing for differential...... entrepreneurship does play a large role, as do shared genes....

  7. Malaysia; Background Paper

    OpenAIRE

    International Monetary Fund

    1996-01-01

    This Background Paper on Malaysia examines developments and trends in the labor market since the mid-1980s. The paper describes the changes in the employment structure and the labor force. It reviews wages and productivity trends and their effects on unit labor cost. The paper highlights that Malaysia’s rapid growth, sustained since 1987, has had a major impact on the labor market. The paper outlines the major policy measures to address the labor constraints. It also analyzes Malaysia’s r...

  8. Quasi MT Inversion of Short-Offset Transient Electromagnetic Data

    Science.gov (United States)

    Chen, Wei-ying; Xue, Guo-qiang; Khan, Muhammad Younis

    2016-07-01

    The short-offset transient electromagnetic method (SOTEM) has been extensively used for mineral and hydrocarbon exploration and hydrogeological investigations due to its ease of use and capability to generate diagnostic subsurface information. At present, the data processing methods of SOTEM are mainly focused on one dimensional inversion. To apply the proven inversion methods of frequency domain electromagnetic methods to SOTEM data, this paper presents a new transformation relation from time to frequency based on the similarity between SOTEM all-time apparent resistivity and magnetotelluric (MT) apparent resistivity. Results show that the transformation coefficients depend on the variation trend of SOTEM all-time apparent resistivity curves. Bostick inversion and conjugate gradient inversion techniques were applied to transformed SOTEM data and the results were validated by some simulated calculations and field measured data. This study provides a novel method to SOTEM data processing and a useful aid to join inversion with MT data.

  9. Development of a precision reverse offset printing system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunchang; Lee, Eonseok; Choi, Young-Man; Kwon, Sin; Lee, Seunghyun; Jo, Jeongdai; Lee, Taik-Min; Kang, Dongwoo, E-mail: dwkang@kimm.re.kr [Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of)

    2016-01-15

    In printed electronics technology, the overlay accuracy of printed patterns is a very important issue when applying printing technology to the production of electric devices. In order to achieve accurate positioning of the printed patterns, this study proposes a novel precision reverse offset printing system. Furthermore, the study evaluates the effects of synchronization and printing force on position errors of the printed patterns, and presents methods of controlling synchronization and printing force so as to eliminate positional errors caused by the above-mentioned reasons. Finally, the printing position repeatability of 0.40 μm and 0.32 μm (x and y direction, respectively) at a sigma level is obtained over the dimension of 100 mm under repeated printing tests with identical printing conditions.

  10. Offset dual reflector antenna for 20/30 GHz

    Science.gov (United States)

    Henderson, R. I.

    The design and testing results of the TDS-6 high performance dual reflector antenna, intended for communications experiments with the ESA Olympus satellite in the 20/30 GHz band, are discussed. The offset Gregorian antenna has an aperture of 2.47 m, and it exhibits high gain while maintaining 90 percent of the sidelobes below 29-25 log theta dBi. The reflector shapes are optimized using the method of diffraction profile synthesis. A wide-band corrugated horn feed with a ring-loaded throat section has been incorporated in the antenna. The results show the achievement of an accuracy of 140-145 microns rms for the main reflectors.

  11. Carrier Frequency Offset Compensation for an Interleaved OFDMA Uplink

    Institute of Scientific and Technical Information of China (English)

    FAN Da; CAO Zhigang

    2008-01-01

    This paper reports an investigation of the carrier frequency offset (CFO) compensation in the up-link of the orthogonal frequency division multiple access (OFDMA) system with interleaved subcarrier as-signment. The presence of CFOs between the transmitters and the uplink receiver will destroy the orthogo-nality among the different subcarriers, resulting in inter-carrier interference and multiuser interference. This paper proposes a pseudoinverse CFO compensation method based on the signal structure. The proposed method can compensate the CFOs of all users simultaneously and isolate the signals from all users at the same time. Compared with the existing CFO compensation methods, the new method provides a consider-able signal-to-noise ratio gain on the bit error rate performance and has a relatively low implementation complexity.

  12. Offset balancing in pseudo-correlation radiometers for CMB measurements

    Science.gov (United States)

    Mennella, A.; Bersanelli, M.; Seiffert, M.; Kettle, D.; Roddis, N.; Wilkinson, A.; Meinhold, P.

    2003-11-01

    Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the PLANCK-LFI pseudo-correlation receivers which uses a tunable gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to PLANCK-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to PLANCK-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.

  13. Offset balancing in pseudo-correlation radiometers for CMB measurements

    CERN Document Server

    Mennella, A; Seiffert, M; Kettle, D; Roddis, N; Wilkinson, A; Meinhold, P; Mennella, Aniello; Bersanelli, Marco; Seiffert, Michael; Kettle, Danielle; Roddis, Neil; Wilkinson, Althea; Meinhold, Peter

    2003-01-01

    Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the Planck-LFI pseudo-correlation receivers which uses a tunable "gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to Planck-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to Planck-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.

  14. The Backgrounds Data Center

    Science.gov (United States)

    Snyder, W. A.; Gursky, H.; Heckathorn, H. M.; Lucke, R. L.; Berg, S. L.; Dombrowski, E. G.; Kessel, R. A.

    1993-01-01

    The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible.

  15. Offsetting Ongoing Methane Emissions --- An Alternative to Emission Equivalence Metrics

    Science.gov (United States)

    Clisby, N.; Enting, I. G.; Lauder, A.; Carter, J.; Cowie, A.; Henry, B.; Raupach, M. R.

    2012-12-01

    The Global Warming Potential (GWP) has been widely adopted as a metric for comparing the climate impact of different greenhouse gases. As has been frequently noted, there are many problems with using GWPs to define emission equivalence in spite of the use of GWPs for this purpose in contexts such as the Kyoto Protocol. We propose that for methane, rather than define emission equivalence, the appropriate comparison is between ongoing emissions of 0.9 to 1.0 kg of CH4 per year and one-off emissions of 1 tonne of carbon. This approach represents an approximate solution to the inverse problem of defining a forcing equivalent index (FEI) that gives exact equivalence of radiative forcing over a range of timescales. In our approach, if ongoing methane emissions are offset by a one-off carbon removal that is built up with 40-year e-folding time, then the result is close to radiatively neutral over periods from years to centuries. In contrast, the GWP provides radiative equivalence (in integrated terms) only at a single time, with large discrepancies at other times. Our approach also follows from consideration of greenhouse gas stabilisation, since stabilising atmospheric CO2 requires an approximate cap on total emissions, while stabilising methane requires stabilisation of ongoing emissions. Our quantitative treatment recognises that, on time scales of centuries, removal of 1 tonne of carbon only lowers the atmospheric carbon content by 0.3 to 0.35 tonnes. We discuss the implications for rangeland grazing systems. In the absence of effective mitigation techniques for methane from rangeland systems, this approach may provide an attractive offset mechanism in spite of requiring that woody vegetation be established and maintained over about 15% of the landscape, or an equivalent amount of carbon storage in soil.

  16. 13 CFR 140.2 - What is a debt and how can the SBA collect it through offset?

    Science.gov (United States)

    2010-01-01

    ... collect it through offset? 140.2 Section 140.2 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION DEBT COLLECTION Offset § 140.2 What is a debt and how can the SBA collect it through offset? (a) A.... (1) Administrative offset. SBA may withhold money it owes to the debtor in order to satisfy the...

  17. An Enhanced Technique for Ultrasonic Flow Metering Featuring Very Low Jitter and Offset.

    Science.gov (United States)

    Hamouda, Assia; Manck, Otto; Hafiane, Mohamed Lamine; Bouguechal, Nour-Eddine

    2016-01-01

    This paper proposes a new, improved method for water flow metering. It applies to a transit time ultrasonic flow meter device. In principle, the flow of a given liquid in a pipe is obtained by measuring the transit times of an ultrasonic wave in the upstream and downstream directions. The difference between these times is, in theory, linearly proportional to the liquid flow velocity. However, the fainter the flow is, the smaller the transit time difference (TTD) is. This difference can be as low as a few picoseconds, which gives rise to many technical difficulties in measuring such a small time difference with a given accuracy. The proposed method relies on measuring the TTD indirectly by computing the phase difference between the steady-state parts of the received signals in the upstream and downstream directions and by using a least-square-sine-fitting technique. This reduces the effect of the jitter noise and the offset, which limit measurement precision at very low flow velocity. The obtained measurement results illustrate the robustness of the proposed method, as we measure the TTD at no-flow conditions, with a precision as low as 10 ps peak-to-peak and a TTD offset of zero, within a temperature range from room temperature to 80 °C. This allows us to reach a smaller minimum detectable flow when compared with previous techniques. The proposed method exhibits a better trade-off between measurement accuracy and system complexity. It can be completely integrated in an ASIC (application specific integrated circuit) or incorporated in a CPU- or micro-controller-based system. PMID:27367701

  18. An Enhanced Technique for Ultrasonic Flow Metering Featuring Very Low Jitter and Offset

    Directory of Open Access Journals (Sweden)

    Assia Hamouda

    2016-06-01

    Full Text Available This paper proposes a new, improved method for water flow metering. It applies to a transit time ultrasonic flow meter device. In principle, the flow of a given liquid in a pipe is obtained by measuring the transit times of an ultrasonic wave in the upstream and downstream directions. The difference between these times is, in theory, linearly proportional to the liquid flow velocity. However, the fainter the flow is, the smaller the transit time difference (TTD is. This difference can be as low as a few picoseconds, which gives rise to many technical difficulties in measuring such a small time difference with a given accuracy. The proposed method relies on measuring the TTD indirectly by computing the phase difference between the steady-state parts of the received signals in the upstream and downstream directions and by using a least-square-sine-fitting technique. This reduces the effect of the jitter noise and the offset, which limit measurement precision at very low flow velocity. The obtained measurement results illustrate the robustness of the proposed method, as we measure the TTD at no-flow conditions, with a precision as low as 10 ps peak-to-peak and a TTD offset of zero, within a temperature range from room temperature to 80 °C. This allows us to reach a smaller minimum detectable flow when compared with previous techniques. The proposed method exhibits a better trade-off between measurement accuracy and system complexity. It can be completely integrated in an ASIC (application specific integrated circuit or incorporated in a CPU- or micro-controller-based system.

  19. A Framework for Implementing and Valuing Biodiversity Offsets in Colombia: A Landscape Scale Perspective

    OpenAIRE

    Shirley Saenz; Tomas Walschburger; Juan Carlos González; Jorge León; Bruce McKenney; Joseph Kiesecker

    2013-01-01

    Biodiversity offsets provide a mechanism for maintaining or enhancing environmental values in situations where development is sought, despite negative environmental impacts. They seek to ensure that unavoidable deleterious environmental impacts of development are balanced by environmental gains. When onsite impacts warrant the use of offsets there is often little attention paid to make sure that the location of offset sites provides the greatest conservation benefit, ensuring they are consist...

  20. FORUM: Indirect leakage leads to a failure of avoided loss biodiversity offsetting

    OpenAIRE

    Moilanen, Atte; Laitila, Jussi

    2015-01-01

    Summary Biodiversity offsetting has quickly gained political support all around the world. Avoided loss (averted risk) offsetting means compensation for ecological damage via averted loss of anticipated impacts through the removal of threatening processes in compensation areas. Leakage means the phenomenon of environmentally damaging activity relocating elsewhere after being stopped locally by avoided loss offsetting. Indirect leakage means that locally avoided losses displace to other admini...

  1. Analysis of wave-field abnormality of big offset VSP data

    Energy Technology Data Exchange (ETDEWEB)

    Peicheng, G.; Guozhu, B.

    1991-01-01

    Bigger offset results in wider VSP image extent and better VSP application. However, there follow two disadvantages, some wavefield abnormality of raw VSP data and increased stretching distortion in VSP-CDP transformation. The casual relation between big offset and VSP first-arrival abnormality or wave group interference is analyzed using the VSP data from well NU34. Suggestions on avoiding wave-field abnormality and designing optimum VSP offset are made by the authors of this paper.

  2. Performance of a novel carrier frequency offset estimation algorithm for OFDM-based WLANs

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presents a novel carrier frequency offset estimation (CFO) algorithm for orthogonal frequency division multiplexing (OFDM)-based Wireless Local Area Networks (WLANs). Compared with previous approaches, this paper extends the whole frequency offset acquisition range by embedding a synthetic algorithm according to the preamble structure of WLANs symbols. The numerical results presented support the effectiveness of this algorithm by which the estimation error of the whole carrier frequency offset in the WLANs is effectively decreased.

  3. Ultraviolet Background Radiation

    Science.gov (United States)

    Henry, R. C.; Murthy, J.

    1993-12-01

    The UVX experiment was carried on the Space Shuttle Columbia between 1986 January 12 and 19 (STS-61C). Several ultraviolet spectrometers were used to obtain measurements of the diffuse ultraviolet background at 8 locations in the sky. We have reanalysed the UVX measurements of the surface brightness of the diffuse ultraviolet background above b = 40 using the dust-scattering model of Onaka & Kodaira (1991), which explicitly takes into account the variation of the source function with galactic longitude. The range of allowed values of interstellar grain albedoJa, and scattering asymmetry parameter g, is considerably expanded over those of a previous analysis. The new chi square probability contours come close to, but do not include, the values of a and g found for the interstellar grains by Witt et al. (1992) using the Ultraviolet Imaging Telescope (UIT) on the Astro mission. If we hypothesize in additon to the dust-scattered light an extragalactic component, of 300 1 100 photons cm-2 s-1 sr-1 A-1, attenuated by a cosecant b law, the new reduction of the UVX data gives complete consistency with the Witt et al. determination of the optical parameters of the grains in the ultraviolet. This work was supported by United States Air Force Contract F19628-93-K-0004, and by National Aeronautics and Space Administration grant NASA NAG5-619. We are grateful for the encouragement of Dr. Stephan Price, and we thank Dr. L. Danly for information. Onaka, T., & Kodaira, K. 1991, ApJ, 379, 532 Witt, A. N., Petersohn, J. K., Bohlin, R. C., O'Connell, R. W., Roberts, M. S., Smith, A. M., & Stecher, T. P. 1992, ApJ, 395, L5

  4. Cosmic microwave background theory.

    Science.gov (United States)

    Bond, J R

    1998-01-01

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in -space are consistent with a DeltaT flat in frequency and broadly follow inflation-based expectations. That the levels are approximately (10(-5))2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Lambda cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 +/- 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 +/- 0.08 for DMR plus the SK95 experiment; 1.00 +/- 0.04 for DMR plus all smaller angle experiments; 1.00 +/- 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Lambda and moderate constraints on Omegatot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant.

  5. Frequency-wavenumber domain phase inversion along reflection wavepaths

    KAUST Repository

    Yu, Han

    2014-12-01

    A background velocity model containing the correct low-wavenumber information is desired for both the quality of the migration image and the success of waveform inversion. To achieve this goal, the velocity is updated along the reflection wavepaths, rather than along both the reflection ellipses and transmission wavepaths as in conventional FWI. This method allows for reconstructing the low-wavenumber part of the background velocity model, even in the absence of long offsets and low-frequency component of the data. Moreover, in gradient-based iterative updates, instead of forming the data error conventionally, we propose to exploit the phase mismatch between the observed and the calculated data. The phase mismatch emphasizes a kinematic error and varies quasi-linearly with respect to the velocity error. The phase mismatch is computed (1) in the frequency-wavenumber (f-k) domain replacing the magnitudes of the calculated common shot gather by those of the observed one, and (2) in the temporal-spatial domain to form the difference between the transformed calculated common-shot gather and the observed one. The background velocity model inverted according to the proposed methods can serve as an improved initial velocity model for conventional waveform inversion. Tests with synthetic and field data show both the benefits and limitations of this method.

  6. Accurate and Simple Time Synchronization and Frequency Offset Correction in OFDM System

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-ming; JIANG Wei-yu; LIU Yuan-an

    2004-01-01

    We present a new synchronization scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems. In this scheme, time synchronization and carrier frequency offset correction can be performed in one identical training symbol. Time synchronization algorithm is robust and simple operated, and its performance is independent of the carrier frequency offset. We derive the theoretical variance error for our time synchronization algorithm in AWGN channel. We also derive the performance lower bound of our frequency offset correction algorithm. The frequency offset correction algorithm is high accuracy and its performance will degrade very little under multipath fading environment.

  7. Exploring residential energy consumers' willingness to accept and pay to offset their CO2-emission

    DEFF Research Database (Denmark)

    Yang, Yingkui; Solgaard, Hans Stubbe

    2015-01-01

    are willing to pay to offset the CO2 emission from electricity consumption. Design/methodology/approach Data was collected using a self-administrated online questionnaire. A sample of size 1022 respondents with useable questionnaires was received. Contingent valuation method is used to measure the willingness...... to pay for carbon offset. Finally, the ordered logit model is used in modelling willing to pay for carbon offset. Findings The results show that there is significant support from residential energy consumer to offset their CO2 emission from electricity consumption. The WTP is motivated by consumers...

  8. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  9. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

  10. Background characterization for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Becerici-Schmidt, Neslihan [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    The GERmanium Detector Array (Gerda) experiment at the LNGS laboratory of INFN searches for the neutrinoless double beta (0νββ) decay of {sup 76}Ge. A discovery of this decay can greatly advance our knowledge on the nature and properties of neutrinos. The current best limit on the half-life of {sup 76}Ge 0νββ decay is 1.9 . 10{sup 25} years (90% C.L.). In order to increase the sensitivity on the half-life with respect to past experiments, the background rate in the energy region of interest (ROI) around Q{sub ββ} = 2039 keV has been reduced by a factor 10. Gerda started data-taking with the full set of Phase I detectors in November 2011. Identification of the background in the first phase of the experiment is of major importance to further mitigate the background for Gerda Phase II. An analysis of the Phase I data resulted in a good understanding of the individual components in the Gerda background spectrum. The background components in the ROI have been identified to be mainly due to β- and γ-induced events originating from {sup 214}Bi ({sup 238}U-series), {sup 208}Tl ({sup 232}Th-series), {sup 42}K (progeny of {sup 42}Ar) and α-induced events coming from isotopes in the {sup 226}Ra decay chain. A background decomposition in the ROI will be presented, with a special emphasis on the contribution from α-induced events.

  11. Genetical background of intelligence.

    Science.gov (United States)

    Junkiert-Czarnecka, Anna; Haus, Olga

    2016-01-01

    Intelligence as an ability to reason, think abstractly and adapt effectively to the environment is a subject of research in the field of psychology, neurobiology, and in the last twenty years genetics as well. Genetical testing of twins carried out from XX century indicated heritebility of intelligence, therefore confirmed an influence of genetic factor on cognitive processes. Studies on genetic background of intelligence focus on dopaminergic (DRD2, DRD4, COMT, SLC6A3, DAT1, CCKAR) and adrenergic system (ADRB2, CHRM2) genes as well as, neutrofins (BDNF) and oxidative stress genes (LTF, PRNP). Positive effect of investigated gene polymorphism was indicated by variation c.957C>T DRD2 gene (if in polymorphic site is thymine), polymorphism c.472G>A COMT gene (presence of adenine) and also gene ADRB2 c.46A->G (guanine), CHRM2 (thymine in place c.1890A>T) and BDNF (guanine in place c.472G>A) Obtained results indicate that intelligence is a feature dependent not only on genetic but also an environmental factor. PMID:27333929

  12. Biological aerosol background characterization

    Science.gov (United States)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  13. The effects of roughness and offset on fracture compliance ratio

    Science.gov (United States)

    Ahmadi, M.; Taleghani, A. Dahi; Sayers, C. M.

    2016-04-01

    Fractures are a source of extra compliance in the rock mass. The mechanical properties of the rock matrix as well as the propagation of seismic waves inside the rock medium are dependent on the magnitude of roughness and offset between the imperfect fracture interfaces. Fracture compliance can estimate the degree of contact between fracture faces, type of fluid filling the fracture and the fracture roughness. To characterize these fracture properties, compliance ratio, known by the ratio of normal-to-shear compliance, can be a potential tool in the subsurface studies to improve the well layout design. The focus of this study is to illustrate how the compliance ratio of a rough fracture, with or without the offset between the fracture faces, can diverge from the compliance ratio of a fracture with smooth interface. Quasi-static and dynamic methods are two common ways to calculate the compliance. The former calculates the compliance by measuring the change in the displacement with the applied stress, while the latter estimates the compliance through monitoring the changes in propagation of seismic waves. To compare the compliance ratios of fractures with imperfect and smooth interfaces in an infinite medium, a numerical finite-element model is built in commercial finite-element software. The imperfect interface of the fracture is modeled with saw-tooth-like structures where they can be partially or fully in contact. The defined saw-tooth-like structures of contact asperities impose an in-plane asymmetry in the shear direction. This asymmetry causes two different values for the compliance in shear direction, known as the soft and stiff shear compliance. Our numerical simulations suggest the increase in the degree of contact between the fracture faces increases the compliance ratio in the stiff direction more than the soft direction. The compliance ratio of the fracture with the imperfect interface is larger than the compliance ratio of the smooth fracture. We suggest

  14. Chopper-stabilized phase detector

    Science.gov (United States)

    Hopkins, P. M.

    1978-01-01

    Phase-detector circuit for binary-tracking loops and other binary-data acquisition systems minimizes effects of drift, gain imbalance, and voltage offset in detector circuitry. Input signal passes simultaneously through two channels where it is mixed with early and late codes that are alternately switched between channels. Code switching is synchronized with polarity switching of detector output of each channel so that each channel uses each detector for half time. Net result is that dc offset errors are canceled, and effect of gain imbalance is simply change in sensitivity.

  15. Enhanced marine sulphur emissions offset global warming and impact rainfall

    Science.gov (United States)

    Grandey, B. S.; Wang, C.

    2015-08-01

    Artificial fertilisation of the ocean has been proposed as a possible geoengineering method for removing carbon dioxide from the atmosphere. The associated increase in marine primary productivity may lead to an increase in emissions of dimethyl sulphide (DMS), the primary source of sulphate aerosol over remote ocean regions, potentially causing direct and cloud-related indirect aerosol effects on climate. This pathway from ocean fertilisation to aerosol induced cooling of the climate may provide a basis for solar radiation management (SRM) geoengineering. In this study, we investigate the transient climate impacts of two emissions scenarios: an RCP4.5 (Representative Concentration Pathway 4.5) control; and an idealised scenario, based on RCP4.5, in which DMS emissions are substantially enhanced over ocean areas. We use mini-ensembles of a coupled atmosphere-ocean configuration of CESM1(CAM5) (Community Earth System Model version 1, with the Community Atmosphere Model version 5). We find that the cooling effect associated with enhanced DMS emissions beneficially offsets greenhouse gas induced warming across most of the world. However, the rainfall response may adversely affect water resources, potentially impacting human livelihoods. These results demonstrate that changes in marine phytoplankton activity may lead to a mixture of positive and negative impacts on the climate.

  16. A Novel Two-step Frequency Offset Estimator for OFDM

    Institute of Scientific and Technical Information of China (English)

    WU Yun; JIANG Xin-hua; XU Wu-jun

    2008-01-01

    Based on an orthogonal frequency division multiplexing (OFDM) training symbol with I identical parts, a novel carrier frequency offset (CFO) estimator is proposed for OFDM systems.The CFO is estimated in two steps, fine estimate and coarse estimate.In the first step, the fine estimation is performed based on the principle of minimum variance.However, the fine estimation has ambiguity since its estimate range is limited.In the second step, the coarse estimation is obtained, which results in a larger estimate range but less precision.Using the coarse estimation, the ambiguity of fine estimation is resolved.To fully use the correlation among L identical parts, the fine estimation resolved the ambiguity and the coarse estimation are optimally combined to obtain the final estimation.Furthermore, the estimation variance of the proposed method is derived.Simulation results demonstrate that the novel two-step estimator outperforms the conventional two-step estimator in terms of estimate performance and computational complexity.

  17. Interference of dark matter solitons and galactic offsets

    Science.gov (United States)

    Paredes, Angel; Michinel, Humberto

    2016-06-01

    By performing numerical simulations, we discuss the collisional dynamics of stable solitary waves in the Schrödinger-Poisson equation. In the framework of a model in which part or all of dark matter is a Bose-Einstein condensate of ultralight axions, we show that these dynamics can naturally account for the relative displacement between dark and ordinary matter in the galactic cluster Abell 3827, whose recent observation is the first empirical evidence of dark matter interactions beyond gravity. The essential assumption is the existence of solitonic galactic cores in the kiloparsec scale. For this reason, we present simulations with a benchmark value of the axion mass ma = 2 × 10-24eV, which is somewhat lower than the one preferred for cosmological structure formation if the field is all of dark matter (ma ≈ 10-22 eV). We argue that future observations might bear out or falsify this coherent wave interpretation of dark matter offsets.

  18. 75 FR 36106 - Agency Information Collection Activities: Distribution of Continued Dumping and Subsidy Offset to...

    Science.gov (United States)

    2010-06-24

    ... Federal Register (75 FR 16493) on April 1, 2010, allowing for a 60-day comment period. One comment was... Continued Dumping and Subsidy Offset to Affected Domestic Producers (CDSOA) AGENCY: U.S. Customs and Border...: Distribution of Continued Dumping and Subsidy Offset to Affected Domestic Procedures. This is a...

  19. 78 FR 36560 - Agency Information Collection Activities: Distribution of Continued Dumping and Subsidy Offset to...

    Science.gov (United States)

    2013-06-18

    ... Continued Dumping and Subsidy Offset to Affected Domestic Producers AGENCY: U.S. Customs and Border... of Continued Dumping and Subsidy Offset to Affected Domestic Producers (CDSOA). This request for... concerning the following information collection: Title: Distribution of Continued Dumping and Subsidy...

  20. 78 FR 55280 - Agency Information Collection Activities: Distribution of Continued Dumping and Subsidy Offset to...

    Science.gov (United States)

    2013-09-10

    ... Register (78 FR 36560) on June 18, 2013, allowing for a 60-day comment period. This notice allows for an... Continued Dumping and Subsidy Offset to Affected Domestic Producers AGENCY: U.S. Customs and Border...: Distribution of Continued Dumping and Subsidy Offset to Affected Domestic Producers (ADPs). This is a...

  1. 77 FR 5416 - Financial Derivatives Transactions To Offset Interest Rate Risk; Investment and Deposit Activities

    Science.gov (United States)

    2012-02-03

    ... transaction. The Board is considering whether to establish exposure limits as a way to guard against such... ADMINISTRATION 12 CFR Part 703 Financial Derivatives Transactions To Offset Interest Rate Risk; Investment and... in certain derivatives transactions for the purpose of offsetting interest rate risk (IRR).\\1\\...

  2. A tuning approach for offset-free MPC with conditional reference adaptation

    DEFF Research Database (Denmark)

    Waschl, Harald; Jørgensen, John Bagterp; Huusom, Jakob Kjøbsted;

    2014-01-01

    or model plant mismatch have to be taken into account the tuning effort to achieve offset-free tracking increases. In this work a novel approach for offset-free MPC is presented, which divides the tuning in two steps, the setup of a nominal MPC loop and an external reference adaptation. The inner nominal...

  3. An offset-trimmable array of magnetic-field-sensitive MOS transistors (MAGFETs)

    DEFF Research Database (Denmark)

    Ning, Feng; Bruun, Erik

    1997-01-01

    . In this paper we present a new combination of an offset compensating circuit and a MAGFET cascade circuit with increased sensitivity. The offset compensation utilizes a digitally trimmable current mirror implemented by a multiple-gate MOS transistor structure. A prototype circuit has been fabricated in a 2.4 mu...

  4. 41 CFR 105-56.008 - Pre-offset paper hearing.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Pre-offset paper hearing. 105-56.008 Section 105-56.008 Public Contracts and Property Management Federal Property Management... General Services Administration Employees § 105-56.008 Pre-offset paper hearing. If a hearing is to...

  5. Band offsets at the crystalline / hydrogenated amorphous silicon interface from first-principles

    Science.gov (United States)

    Hazrati, Ebrahim; Jarolimek, Karol; de Wijs, Gilles A.; InstituteMolecules; Materials Team

    2015-03-01

    The heterojunction formed between crystalline silicon (c-Si) and hydrogenated amorphous silicon (a-Si:H) is a key component of a new type of high-efficiency silicon solar cell. Since a-Si:H has a larger band gap than c-Si, band offsets are formed at the interface. A band offset at the minority carrier band will mitigate recombination and lead to an increased efficiency. Experimental values of band offsets scatter in a broad range. However, a recent meta-analysis of the results (W. van Sark et al.pp. 405, Springer 2012) gives a larger valence offset (0.40 eV) than the conduction offset (0.15 eV). In light of the conflicting reports our goal is to calculate the band offsets at the c-Si/a-Si:H interface from first-principles. We have prepared several atomistic models of the interface. The crystalline part is terminated with (111) surfaces on both sides. The amorphous structure is generated by simulating an annealing process at 1100 K, with DFT molecular dynamics. Once the atomistic is ready it can be used to calculate the electronic structure of the interface. Our preliminary results show that the valence offset is larger than the conduction band offset.

  6. Improved SAR Amplitude Image Offset Measurements for Deriving Three-Dimensional Coseismic Displacements

    KAUST Repository

    Wang, Teng

    2015-02-03

    Offsets of synthetic aperture radar (SAR) images have played an important role in deriving complete three-dimensional (3-D) surface displacement fields in geoscientific applications. However, offset maps often suffer from multiple outliers and patch-like artifacts, because the standard offset-measurement method is a regular moving-window operation that does not consider the scattering characteristics of the ground. Here, we show that by focusing the offset measurements on predetected strong reflectors, the reliability and accuracy of SAR offsets can be significantly improved. Application to the 2011 Van (Turkey) earthquake reveals a clear deformation signal from an otherwise decorrelated interferogram, making derivation of the 3-D coseismic displacement field possible. Our proposed method can improve mapping of coseismic deformation and other ground displacements, such as glacier flow and landslide movement when strong reflectors exist.

  7. Numerical simulation of offset-drain amorphous oxide-based thin-film transistors

    Science.gov (United States)

    Jeong, Jaewook

    2016-11-01

    In this study, we analyzed the electrical characteristics of amorphous indium–gallium–zinc-oxide (a-IGZO) thin-film transistors (TFTs) with an offset-drain structure by technology computer aided design (TCAD) simulation. When operating in a linear region, an enhancement-type TFT shows poor field-effect mobility because most conduction electrons are trapped in acceptor-like defects in an offset region when the offset length (L off) exceeds 0.5 µm, whereas a depletion-type TFT shows superior field-effect mobility owing to the high free electron density in the offset region compared with the trapped electron density. When operating in the saturation region, both types of TFTs show good field-effect mobility comparable to that of a reference TFT with a large gate overlap. The underlying physics of the depletion and enhancement types of offset-drain TFTs are systematically analyzed.

  8. Industry perspectives on carbon-offset programs in Canada and the United States

    Directory of Open Access Journals (Sweden)

    Rachel Dodds

    2012-08-01

    Full Text Available Carbon offsetting is often put forward as a possible mitigation strategy for climate change. This study examines carbon-offset businesses in Canada and the United States to better understand their standards, project types, and project locations and to determine their perspectives regarding the challenges of the carbon-offset industry. Twenty companies (a 40% response rate agreed to a structured interview, although many were reluctant to share some information. Several salient themes emerged and are discussed in more detail: involvement of the hospitality and tourism industry, financial commitment, confusion in the marketplace, transparency, and needs for education. Implementation of three recommendations—covering standardization, education, and further engagement among the industry, its customers, and researchers—could reduce confusion and increase the transparency of carbon offsetting. Yet these changes might not help business since customers might decide that purchasing carbon offsets does little to address climate change.

  9. Frequency comb offset dynamics of SESAM modelocked thin disk lasers.

    Science.gov (United States)

    Emaury, Florian; Diebold, Andreas; Klenner, Alexander; Saraceno, Clara J; Schilt, Stéphane; Südmeyer, Thomas; Keller, Ursula

    2015-08-24

    We present a detailed study of the carrier-envelope offset (CEO) frequency dynamics of SESAM modelocked thin disk lasers (TDLs) pumped by kW-class highly transverse multimode pump diodes with a typical M(2) value of 200-300, and give guidelines for future frequency stabilization of multi-100-W oscillators. We demonstrate CEO frequency detection with > 30 dB signal-to-noise ratio with a resolution bandwidth of 100 kHz from a SESAM modelocked Yb:YAG TDL delivering 140 W average output power with 748-fs pulses at 7-MHz pulse repetition rate. We compare with a low-power CEO frequency stabilized Yb:CALGO TDL delivering 2.1 W with 77-fs pulses at 65 MHz. For both lasers, we perform a complete noise characterization, measure the relevant transfer functions (TFs) and compare them to theoretical models. The measured TFs are used to determine the propagation of the pump noise step-by-step through the system components. From the noise propagation analysis, we identify the relative intensity noise (RIN) of the pump diode as the main contribution to the CEO frequency noise. The resulting noise levels are not excessive and do not prevent CEO frequency stabilization. More importantly, the laser cavity dynamics are shown to play an essential role in the CEO frequency dynamics. The cavity TFs of the two lasers are very different which explains why at this point a tight CEO frequency lock can be obtained with the Yb:CALGO TDL but not with the Yb:YAG TDL. For CEO stabilization laser cavities should exhibit high damping of the relaxation oscillations by nonlinear intra-cavity elements, for example by operating a SESAM in the roll-over regime. Therefore the optimum SESAM operation point is a trade-off between enough damping and avoiding multiple pulsing instabilities. Additional cavity components could be considered for supplementary damping independent of the SESAM operation point. PMID:26368160

  10. Prediction of three-dimensional femoral offset from AP pelvis radiographs in primary hip osteoarthritis

    International Nuclear Information System (INIS)

    Background: In pre-operative planning for total hip arthroplasty (THA), femoral offset (FO) is frequently underestimated on AP pelvis radiographs as a result of inaccurate patient positioning, imprecise magnification, and radiographic beam divergence. The aim of the present study was to evaluate the accuracy and reliability of predicting three-dimensional (3-D) FO from standardised AP pelvis radiographs. Methods: In a retrospective cohort study, pre-operative AP pelvis radiographs, AP hip radiographs and CT scans of a consecutive series of 345 patients (345 hips, 146 males, 199 females, mean age 60 (range: 40–79) years, mean body-mass-index 27 (range: 19–57) kg/m2) with primary end-stage hip OA were reviewed. Patients were positioned according to a standardised protocol and all images were calibrated. Using validated custom programmes, FO was measured on corresponding radiographs and CT scans. Measurement reliability was evaluated using intra-class-correlation-coefficients. To predict 3-D FO from AP pelvis measurements and to assess the accuracy compared to CT, the entire cohort was randomly split into subgroups A and B. Gender specific regression equations were derived from group A (245 patients) and the accuracy of prediction was evaluated in group B (100 patients) using Bland–Altman plots. Results: In the entire cohort, mean FO was 39.2 mm (95%CI: 38.5–40.0 mm) on AP pelvis radiographs, 44.1 mm (95%CI: 43.4–44.9 mm) on AP hip radiographs and 44.6 mm (95%CI: 44.0–45.2 mm) on CT scans. In group B, we observed no significant difference between gender specific predicted FO (males: 48.0 mm, 95%CI: 47.1–48.8 mm; females: 42.0 mm, 95%CI: 41.1–42.8 mm) and FO as measured on CT (males: 47.7 mm, 95%CI: 46.1–49.4 mm, p = 0.689; females: 41.6 mm, 95%CI: 40.3–43.0 mm, p = 0.607). Conclusions: The present study suggests that FO can be accurately and reliably predicted from AP pelvis radiographs in patients with primary end-stage hip osteoarthritis. Our

  11. Prediction of three-dimensional femoral offset from AP pelvis radiographs in primary hip osteoarthritis

    Energy Technology Data Exchange (ETDEWEB)

    Merle, C., E-mail: christian.merle@med.uni-heidelberg.de [Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford (United Kingdom); Department of Orthopaedic and Trauma Surgery, University Hospital Heidelberg (Germany); Waldstein, W., E-mail: wwaldstein@gmail.com [Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford (United Kingdom); Department of Orthopaedic and Trauma Surgery, University Hospital Heidelberg (Germany); Pegg, E.C., E-mail: elise.pegg@ndorms.ox.ac.uk [Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford (United Kingdom); Streit, M.R., E-mail: marcus.streit@med.uni-heidelberg.de [Department of Orthopaedic and Trauma Surgery, University Hospital Heidelberg (Germany); Gotterbarm, T., E-mail: tobias.gotterbarm@med.uni-heidelberg.de [Department of Orthopaedic and Trauma Surgery, University Hospital Heidelberg (Germany); Aldinger, P.R., E-mail: peter.aldinger@diak-stuttgart.de [Department of Orthopaedic Surgery, Paulinenhilfe, Diakonieklinikum, Stuttgart (Germany); Murray, D.W., E-mail: david.murray@ndorms.ox.ac.uk [Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford (United Kingdom); Gill, H.S., E-mail: r.gill@bath.ac.uk [Department of Mechanical Engineering, University of Bath (United Kingdom)

    2013-08-15

    Background: In pre-operative planning for total hip arthroplasty (THA), femoral offset (FO) is frequently underestimated on AP pelvis radiographs as a result of inaccurate patient positioning, imprecise magnification, and radiographic beam divergence. The aim of the present study was to evaluate the accuracy and reliability of predicting three-dimensional (3-D) FO from standardised AP pelvis radiographs. Methods: In a retrospective cohort study, pre-operative AP pelvis radiographs, AP hip radiographs and CT scans of a consecutive series of 345 patients (345 hips, 146 males, 199 females, mean age 60 (range: 40–79) years, mean body-mass-index 27 (range: 19–57) kg/m{sup 2}) with primary end-stage hip OA were reviewed. Patients were positioned according to a standardised protocol and all images were calibrated. Using validated custom programmes, FO was measured on corresponding radiographs and CT scans. Measurement reliability was evaluated using intra-class-correlation-coefficients. To predict 3-D FO from AP pelvis measurements and to assess the accuracy compared to CT, the entire cohort was randomly split into subgroups A and B. Gender specific regression equations were derived from group A (245 patients) and the accuracy of prediction was evaluated in group B (100 patients) using Bland–Altman plots. Results: In the entire cohort, mean FO was 39.2 mm (95%CI: 38.5–40.0 mm) on AP pelvis radiographs, 44.1 mm (95%CI: 43.4–44.9 mm) on AP hip radiographs and 44.6 mm (95%CI: 44.0–45.2 mm) on CT scans. In group B, we observed no significant difference between gender specific predicted FO (males: 48.0 mm, 95%CI: 47.1–48.8 mm; females: 42.0 mm, 95%CI: 41.1–42.8 mm) and FO as measured on CT (males: 47.7 mm, 95%CI: 46.1–49.4 mm, p = 0.689; females: 41.6 mm, 95%CI: 40.3–43.0 mm, p = 0.607). Conclusions: The present study suggests that FO can be accurately and reliably predicted from AP pelvis radiographs in patients with primary end-stage hip osteoarthritis

  12. S-NPP VIIRS DNB Dark Offset and Detector Dark Current Trending Study

    Science.gov (United States)

    Sun, Z.; Chen, W.; DeLuccia, F.; Moy, G.

    2015-12-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB) is a panchromatic band in the VisNIR spectral range from 0.5 to 0.9 μm with a dynamic range from 3x10-9 to about 0.02 W cm-2 sr-1. DNB achieves this large dynamic range by having three gain stages: low gain (LGS), mid gain (MGS), and high gain (HGS). HGS is the average of two redundant detector arrays, HGA and HGB. The HGS offset determination is critically important to improve the imagery capability and calibration accuracy and stability at novel low radiances. Currently, the dark offset is determined on a monthly basis by observing new moon data in the dark regions in the Pacific Ocean. The data is mainly comprised of detector dark current, electronic/clock offsets, artificial illumination sources, and nighttime airglow contamination. The first two are instrument phenomena/characterizations and the last two are scene contaminations.In this presentation, we discuss the long-term growth in offset with short-term fluctuations we have captured since the beginning of the mission. We associate the long-term growth with dark current increase. We show that the offset rate of change over time is proportional to the number of Charge Coupled Device (CCD) elements aggregated to comprise a DNB pixel. We compare offset growth rate from new moon data in the dark ocean and that from calibration sector data at the same time; which contain very limited scene contaminations. We associate the short-term variability in offset growth with airglow effects that survive the filtering process used to derive the offsets from dark ocean data. These spurious offset fluctuations are removed from the offset LUTs via long time scale smoothing of the offsets. The remaining persistent time average contribution due to airglow can be estimated by comparison of the pitch maneuver propagated offsets determined from deep space scans early in the mission and the offsets determined from the dark regions in the Pacific Ocean.

  13. Blind Identification of Distributed Antenna Systems with Multiple Carrier Frequency Offsets

    CERN Document Server

    Yu, Yuanning; Poor, H Vincent

    2007-01-01

    In spatially distributed multiuser antenna systems, the received signal contains multiple carrier-frequency offsets (CFOs) arising from mismatch between the oscillators of transmitters and receivers. This results in a time-varying rotation of the data constellation, which needs to be compensated at the receiver before symbol recovery. In this paper, a new approach for blind CFO estimation and symbol recovery is proposed. The received base-band signal is over-sampled, and its polyphase components are used to formulate a virtual Multiple-Input Multiple-Output (MIMO) problem. By applying blind MIMO system estimation techniques, the system response can be estimated and decoupled versions of the user symbols can be recovered, each one of which contains a distinct CFO. By applying a decision feedback Phase Lock Loop (PLL), the CFO can be mitigated and the transmitted symbols can be recovered. The estimated MIMO system response provides information about the CFOs that can be used to initialize the PLL, speed up its ...

  14. Nyquist WDM superchannel using offset-16QAM and receiver-side digital spectral shaping.

    Science.gov (United States)

    Xiang, Meng; Fu, Songnian; Tang, Ming; Tang, Haoyuan; Shum, Perry; Liu, Deming

    2014-07-14

    The performance of Nyquist WDM superchannel using advanced modulation formats with coherent detection is degraded due to the existence of both inter-symbol interference (ISI) and inter-channel interference (ICI). Here, we propose and numerically investigate a Nyquist WDM superchannel using offset-16QAM and receiver-side digital spectral shaping (RS-DSS), achieving a spectral efficiency up to 7.44 bit/s/Hz with 7% hard-decision forward error correction (HD-FEC) overhead. Compared with Nyquist WDM superchannel using 16QAM and RS-DSS, the proposed system has 1.4 dB improvement of required OSNR at BER = 10(-3) in the case of back-to-back (B2B) transmission. Furthermore, the range of launched optical power allowed beyond HD-FEC threshold is drastically increased from -6 dBm to 1.2 dBm, after 960 km SSMF transmission with EDFA-only. In particular, no more than 1.8 dB required OSNR penalty at BER = 10(-3) is achieved for the proposed system even with the phase difference between channels varying from 0 to 360 degree.

  15. Effect of Magnetic Field on Entropy Generation in a Microchannel Heat Sink with Offset Fan Shaped

    Directory of Open Access Journals (Sweden)

    Mohammad Nasiri

    2015-12-01

    Full Text Available In this study, convection flow in microchannel heat sink with offset fan-shaped reentrant cavities in sidewall filled with Fe3O4-water is numerically investigated. The effects of changing some parameters such as Reynolds number and magnetic field are considered. The nanofluid flow is laminar, steady and incompressible, while the thermo-physical properties of nanoparticles were assumed constant. A finite volume method and two phase mixture models were used to simulate the flow. The obtained results show that the frictional entropy generation increases as Reynolds number increases, while a reverse trend is observed for thermal entropy generation. By applying a non-uniform magnetic field, the entropy generation due to heat transfer decreases at first and then increases. When using the uniform magnetic field, the frictional entropy generation and thermal entropy generation is negligible. For all studied cases, the total entropy generation decreases using non-uniform magnetic fields. The results indicate that by increasing the magnetic field power, the total entropy generation decreases.

  16. Simulation of cosmological stochastic background in LISA

    International Nuclear Information System (INIS)

    A pilot study has been carried out to simulate stochastic gravitational wave background originating from first order phase transitions in the early universe. The space based gravitational wave detector LISA will be operational in the range of 10-4 to 0.1 Hz and could be sensitive to the red shifted gravitational waves from cosmological origin. In this study we have modeled the signals from first order phase transitions and we compared the signal both with the expected instrumental noise and realistic simulated foreground signals, originating from the white dwarf population in our galaxy.

  17. Polarization Observations with the Cosmic Background Imager

    CERN Document Server

    Readhead, A C S; Pearson, T J; Sievers, J L; Mason, B S; Contaldi, C R; Bond, J R; Bustos, R; Altamirano, P; Achermann, C; Bronfman, L; Carlstrom, J E; Cartwright, J K; Casassus, S; Dickinson, C; Holzapfel, W L; Kovács, J M; Leitch, E M; May, J; Padin, S; Pogosyan, D; Pospieszalski, M; Pryke, C L; Reeves, R; Shepherd, M C; Torres, S

    2004-01-01

    Polarization observations of the cosmic microwave background with the Cosmic Background Imager over the period September 2002 - May 2004 provide a highly significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum, as predicted by theory. This key agreement between the phase of the observed polarization spectrum and that predicted based on the total intensity spectrum provides new support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models.

  18. MECHANISM RESEARCH FOR 3D NON-AXISYMMETRIC THIN-WALL TUBE OFFSET SPINNING

    Institute of Scientific and Technical Information of China (English)

    KUANG Weihua; XIA Qinxiang; RUAN Feng

    2006-01-01

    Difference of offset spinning with conventional symmetric spinning is analyzed. A 3D FEM model for offset tube neck-spinning is established and the spinning process is simulated by means of ANSYS software. Dynamic boundary and contact problems in simulation are solved. Transient stress distribution of contact area, transient strain distribution of nodes in typical section and strain distribution of the workpiece at last are attained, the place and the cause of crack are analyzed.Strain variation curves with time of offset spinning and conventional spinning are compared. It shows the mechanism difference between offset spinning and conventional spinning. In addition, simulation results show how strain distribution of typical section, thickness of some typical nodes, axial extension in left section and force of three rollers change with time. According to the study of the variation curve, material flow law along radial, tangential and axial direction is attained and the whole spinning process is studied. The simulation results discover that offset distance is the key to manufacture offset non-symmetric tube, and process parameters change with spinning angle. Experiment data really reflect different process parameters' influence on conventional symmetric and offset spinning force.Experiments accord well with simulation.

  19. Low-Complexity Carrier Frequency Offset Estimation Algorithm in TD-LTE

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2013-10-01

    Full Text Available Frequency offset estimation is an important module in the downlink synchronization process of orthogonal frequency division multiplexing (OFDM system. Research on frequency synchronization of OFDM, a low-complexity and efficient method is proposed to evaluate frequency offset in this paper. In general, maximum likelihood (ML based on cyclic prefix (CP and primary synchronization signal (PSS frequency-domain cross-correlation algorithm are applied for fractional carrier frequency offset estimation. PSS time-domain cross-correlation algorithm is used to estimate integral carrier frequency offset. However, for fractional carrier frequency estimation, the performance of ML based on CP degrades in fading channel. The complexity of the other algorithm is high. Also, the conventional integral carrier frequency estimation requires cross-correlation between the received PSS and local PSS or auto-correlation of received PSS, so they also have great complexity. In this paper, relying on the PSS time center-symmetric property, we perform PSS auto-correlation method twice in the time domain. Hence fractional carrier frequency offset is obtained and compensated. Next, relying on the PSS frequency center-symmetric property, we perform energy difference computations to estimate the integral carrier frequency offset, which is equal to the distance between the calculated minimum and the central frequency in frequency domain. Simulation results demonstrate that the proposed algorithm can estimate frequency offset accurately, guarantee the reliance and reduce complexity in comparison with the normal methods

  20. A Framework for Implementing and Valuing Biodiversity Offsets in Colombia: A Landscape Scale Perspective

    Directory of Open Access Journals (Sweden)

    Shirley Saenz

    2013-11-01

    Full Text Available Biodiversity offsets provide a mechanism for maintaining or enhancing environmental values in situations where development is sought, despite negative environmental impacts. They seek to ensure that unavoidable deleterious environmental impacts of development are balanced by environmental gains. When onsite impacts warrant the use of offsets there is often little attention paid to make sure that the location of offset sites provides the greatest conservation benefit, ensuring they are consistent with landscape level conservation goals. In most offset frameworks it is difficult for developers to proactively know the offset requirements they will need to implement. Here we propose a framework to address these needs. We propose a series of rules for selecting offset sites that meet the conservation needs of potentially impacted biological targets. We then discuss an accounting approach that seeks to support offset ratio determinations based on a structured and transparent approach. To demonstrate the approach, we present a framework developed in partnership with the Colombian Ministry of Environment and Sustainable Development to reform existing mitigation regulatory processes.

  1. Constraining sub-parsec binary supermassive black holes in quasars with multi-epoch spectroscopy. II. The population with kinematically offset broad Balmer emission lines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Bian, Fuyan [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Loeb, Abraham [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tremaine, Scott, E-mail: xinliu@astro.ucla.edu [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2014-07-10

    first-epoch spectrum and the average acceleration between two epochs, which could be explained by orbital phase modulation when the time separation between two epochs is a non-negligible fraction of the orbital period of the motion causing the line displacement. We discuss the implications of our results for the identification of sub-pc BBH candidates in offset-line quasars and for the constraints on their frequency and orbital parameters.

  2. Background reduction in the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Segui, L. [University of Oxford, Denys Wilkinson Building, Keble Road, OX1 Oxford (United Kingdom)

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  3. Multidimensional J-driven NMR correlations by single-scan offset-encoded recoupling

    Science.gov (United States)

    Lin, Yulan; Lupulescu, Adonis; Frydman, Lucio

    2016-04-01

    Two-dimensional (2D) correlations between bonded heteroatoms, lie at the cornerstone of many uses given to contemporary nuclear magnetic resonance (NMR). Improving the efficiency with which these correlations are established is an important topic in modern NMR, with potential applications in rapid chemical analysis and dynamic biophysical studies. Alternatives have been developed over the last decade to speed up these experiments, based among others on reducing the number of data points that need to be sampled, and/or shortening the inter-scan delays. Approaches have also been proposed to forfeit multi-scan schemes altogether, and complete full 2D correlations in a single shot. Here we explore and discuss a new alternative enabling the collection of such very fast - in principle, single-scan - acquisitions of 2D heteronuclear correlations among bonded species, which operates on the basis of a partial reintroduction of J couplings. Similar approaches had been proposed in the past based on collecting coupled spectra for arrays of off-resonance decoupling values; the proposal that is here introduced operates on the basis of suitably incorporating frequency-swept pulses, into spin-echo sequences. Thanks to the offset-dependent amplitude modulations of the in- and anti-phase components that such sequences impart, chemical shifts of coupled but otherwise unobserved nuclear species, can be extracted from the relative intensities and phases of J-coupled multiplets observed in one-dimensional acquisitions. A description of the steps needed to implement this rapid acquisition approach in a quantitative fashion, as well as applications of the ensuing sequences, are presented.

  4. The offset-midpoint traveltime pyramid of P-waves in homogeneous orthorhombic media

    KAUST Repository

    Hao, Qi

    2016-07-18

    The offset-midpoint traveltime pyramid describes the diffraction traveltime of a point diffractor in homogeneous media. We have developed an analytic approximation for the P-wave offset-midpoint traveltime pyramid for homogeneous orthorhombic media. In this approximation, a perturbation method and the Shanks transform were implemented to derive the analytic expressions for the horizontal slowness components of P-waves in orthorhombic media. Numerical examples were shown to analyze the proposed traveltime pyramid formula and determined its accuracy and the application in calculating migration isochrones and reflection traveltime. The proposed offset-midpoint traveltime formula is useful for Kirchhoff prestack time migration and migration velocity analysis for orthorhombic media.

  5. [Offsets under the Kyoto Protocol : economic requirements for post Kyoto emissions trading

    International Nuclear Information System (INIS)

    The Greenhouse Emissions Management Consortium (GEMCo) is a group of Canadian companies, all of which are carbon producing. GEMCo develops offset projects (emissions trading) for its members. This presentation outlines the economic risks involved in investing in emissions trading by attempting to answer questions about what the risks are, what are the elements that make up that risk, whether to focus on spending on offsets or on reducing the risk, what are the risks of carbon constraints and where they are likely to come from (regulation or trade action), and what are the best markets for buying offsets. Methods to determine the degree of risk are explored and assessed

  6. Laser frequency offset locking scheme for high-field imaging of cold atoms

    CERN Document Server

    Puentes, Graciana

    2011-01-01

    We present a simple and flexible frequency offset locking scheme developed for high-field imaging of ultra-cold atoms which relies on commercially available RF electronics only. The main new ingredient is the use of the sharp amplitude response of a home-made RF filter to provide an error signal for locking the lasers. We were able to offset lock two independent diode lasers within a capture range of 200 MHz, and with a tuning range of up to 1.4GHz. The beat-note residual fluctuations for offset locked lasers are bellow 2MHz for integration times of several hundreds of seconds.

  7. Supergravity backgrounds and symmetry superalgebras

    CERN Document Server

    Ertem, Ümit

    2016-01-01

    We consider the bosonic sectors of supergravity theories in ten and eleven dimensions which correspond to the low energy limits of string theories and M-theory. The solutions of supergravity field equations are known as supergravity backgrounds and the number of preserved supersymmetries in those backgrounds are determined by Killing spinors. We provide some examples of supergravity backgrounds which preserve different fractions of supersymmetry. An important invariant for the characterization of supergravity backgrounds is their Killing superalgebras which are constructed out of Killing vectors and Killing spinors of the background. After constructing Killing superalgebras of some special supergravity backgrounds, we discuss about the possibilities of the extensions of these superalgebras to include the higher degree hidden symmetries of the background.

  8. Scientific background of the project

    International Nuclear Information System (INIS)

    The main objective of the proposed project is the development of radioimmunometric assay(s) for the determination of free and total PSA in serum samples from normal and pathological individuals (BPH, PCa). This will be achieved by: A. Selection of appropriate antibody pairs (capture and labelled antibody) for determination of total PSA (free and complex) and for determination of free PSA. From bibliography we have already spotted some antibody pairs. B. Radiolabelling of antibodies. Several labelling and purification procedures will be followed in order to obtain the required analytical sensitivity and dynamic range of the assays. Special attention will be given to the affinity constant as well as to the stability of the radiolabelled molecules. C. Development of protocols for immobilisation of capture antibodies. We will use several solid support formats (plastic tubes, beads and magnetizable particles). Direct adsorption or covalent binding will be used. Immunoadsorption through immobilised second antibody will be also tested in order to decrease the preparation cost of the solid phase reagents. D. Preparation of standards of suitable purity levels. We will test different PSA-free matrices (Bovine serum, buffer solutions etc.) in order to select the most appropriate among them in terms of low background determination and low reagents cost. E. Optimisation of the immunoassays conditions for the free PSA and total PSA (e.g. assay buffers, incubation time, temperature, one or two step procedure, washings). F. Optimisation and standardisation of assay protocols for kit production. G. Production of kits for distribution in clinical laboratories in Greece for comparison with commercial kits. H. Evaluation of the developed assays in real clinical conditions using well characterised human serum samples. This will be performed in co-operation with the Hellenic Society for Tumor Markers, and other anticancer institutions and hospital clinicians of long standing relation

  9. Distance Dependent Offsets between Parallaxes for Nearby Stars and Gaia DR1 Parallaxes

    CERN Document Server

    Jao, Wei-Chun; Riedel, Adric R; Winters, Jennifer G; Slatten, Kenneth J; Gies, Douglas R

    2016-01-01

    We use 612 single stars with previously published trigonometric parallaxes placing them within 25 pc to evaluate parallaxes released in Gaia's first data release (DR1). We find that the Gaia parallaxes are, on average, $0.24 \\pm 0.02$ mas smaller than the weighted mean trigonometric parallax values for these stars in the solar neighborhood. We also find that the offset changes with distance out to 100 pc, in the sense that the closer the star, the larger the offset. We find no systematic trends in the parallax offsets with stellar $V$ magnitude, $V-K$ color, or proper motion. We do find that the offset is roughly twice as large for stars south of the ecliptic compared to those that are north.

  10. Beam models for radio sources. III. Offset sources and single jets

    International Nuclear Information System (INIS)

    The early stages of radio source evolution are studied using a modified version of our previously developed approach to the twin beam model. A continuous source of energy and relativistic plasma lies within a cloud of confining gas in an active galactic nucleus. The nature of ''engine'' is not specified, but we assume an initially symmetric ejection of plasma. The boundary between the relativistic plasma and the confining medium is calculated using several approximations, and we treat the source's nondimensional reduced luminosity, its offset from the confining cloud's center, and the cloud's eccentricity as the key parameters, as the other properties of the cloud can be coupled with the engine's power to give the reduced luminosity. We conclude: sources with low energy tend to form bubbles while those with higher luminosities form jets; larger offsets increase the probability of direct jet formation; higher eccentricities provide better collimation, as do smaller offsets; even low offsets produce single jets or plasmoid streams in one direction

  11. An offset cancellation technique in a switched-capacitor comparator for SAR ADCs

    International Nuclear Information System (INIS)

    An offset cancellation technique for a SAR (successive approximation register) ADC switched-capacitor comparator is described. The comparator is designed with a pre-amplifying and regenerative latching structure and realized in 0.18 μm CMOS. With the first stage preamplifier offset cancellation and low offset regenerative latching approach, the equivalent offset of the comparator is reduced to < 0.55 mV. By using the pre-amplifying and regenerative latching comparison mode the comparator exhibits low power dissipation. Under a 1.8 V power supply, with a 200 kS/s ADC sampling rate and 3 MHz clock frequency, a 13-bit comparison resolution is reached and less than 0.09 mW power dissipation is consumed. The superiority of this comparator is discussed and proved by the post-simulation and application to a 10 bit 200 kS/s touch screen SAR A/D converter. (semiconductor integrated circuits)

  12. Pair Cascades and Deathlines in Magnetic Fields with Offset Polar Caps

    Science.gov (United States)

    Harding, Alice K.; Muslimov, Alex G.

    2012-01-01

    We present results of electron-positron pair cascade simulations in a dipole magnetic field whose polar cap is offset from the dipole axis. In such a field geometry, the polar cap is displaced a small fraction of the neutron star radius from the star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the offset polar cap, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset. We find that the pair multiplicity can change dr;unatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity. The results have some important implications for pulsar particle production, high-energy emission and cosmic-ray contribution.

  13. Dynamics analysis of microsphere in a dual-beam fiber-optic trap with transverse offset.

    Science.gov (United States)

    Chen, Xinlin; Xiao, Guangzong; Luo, Hui; Xiong, Wei; Yang, Kaiyong

    2016-04-01

    A comprehensive dynamics analysis of microsphere has been presented in a dual-beam fiber-optic trap with transverse offset. As the offset distance between two counterpropagating beams increases, the motion type of the microsphere starts with capture, then spiral motion, then orbital rotation, and ends with escape. We analyze the transformation process and mechanism of the four motion types based on ray optics approximation. Dynamic simulations show that the existence of critical offset distances at which different motion types transform. The result is an important step toward explaining physical phenomena in a dual-beam fiber-optic trap with transverse offset, and is generally applicable to achieving controllable motions of microspheres in integrated systems, such as microfluidic systems and lab-on-a-chip systems. PMID:27137046

  14. Blind Spectrum Sensing in Cognitive Radio over Fading Channels and Frequency Offsets

    CERN Document Server

    Nevat, Ido; Yuan, Jinhong

    2010-01-01

    This paper deals with the challenging problem of spectrum sensing in cognitive radio. We consider a stochastic system model where the the Primary User (PU) transmits a periodic signal over fading channels. The effect of frequency offsets due to oscillator mismatch, and Doppler offset is studied. We show that for this case the Likelihood Ratio Test (LRT) cannot be evaluated poitnwise. We present a novel approach to approximate the marginilisation of the frequency offset using a single point estimate. This is obtained via a low complexity Adaptive Notch Filter (ANF) to estimate the frequency offset. Performance is evaluated via numerical simulations and it is shown that the proposed spectrum sensing scheme can achieve the same performance as the "near-optimal" scheme, that is based on a bank of matched filters, using only a fraction of the complexity required.

  15. The case for background independence

    CERN Document Server

    Smolin, L

    2005-01-01

    The aim of this paper is to explain carefully the arguments behind the assertion that the correct quantum theory of gravity must be background independent. We begin by recounting how the debate over whether quantum gravity must be background independent is a continuation of a long-standing argument in the history of physics and philosophy over whether space and time are relational or absolute. This leads to a careful statement of what physicists mean when we speak of background independence. Given this we can characterize the precise sense in which general relativity is a background independent theory. The leading background independent approaches to quantum gravity are then discussed, including causal set models, loop quantum gravity and dynamical triangulations and their main achievements are summarized along with the problems that remain open. Some first attempts to cast string/M theory into a background independent formulation are also mentioned. The relational/absolute debate has implications also for ot...

  16. A practical approach to offset permits in post Kyoto climate policy

    OpenAIRE

    Heindl, Peter; Voigt, Sebastian

    2011-01-01

    International Carbon Offsets from developing countries and emerging economies such as permits from the Clean Development Mechanism (CDM) will potentially play an important role for cost containment in domestic greenhouse gas regulation schemes in industrialised countries. We analyse the potential role of offset permits assuming that major emitters such as the USA, Canada, Japan, Australia and New Zealand install domestic greenhouse gas regulation schemes to achieve the emissions reductions pl...

  17. Australia’s marginal tax rates, tax offsets and the Medicare levy

    OpenAIRE

    Keldon Pattugalan; David Ellis

    2010-01-01

    Australia has a progressive personal income tax schedule with a seemingly simple five rate structure (including a zero rate). Overlaying the statutory tax schedule are more than 40 offsets designed to reduce tax liability for certain taxpayers. These offsets add complexity to the tax system and result in a person’s tax liability being determined by several factors, not just their level of income as implied by the statutory schedule. In this article, we discuss the adverse impacts of high leve...

  18. Stakeholders of Voluntary Forest Carbon Offset Projects in China: An Empirical Analysis

    OpenAIRE

    Derong Lin; Yingzhi Lin

    2015-01-01

    Climate change is one of the defining challenges facing the planet. Voluntary forest carbon offset project which has the potential to boost forest carbon storage and mitigate global warming has aroused the global concern. The objective of this paper is to model the game situation and analyze the game behaviors of stakeholders of voluntary forest carbon offset projects in China. A stakeholder model and a Power-Benefit Matrix are constructed to analyze the roles, behaviors, and conflicts of sta...

  19. Biodiversity Offsets: A Cost-Effective Interim Solution to Seabird Bycatch in Fisheries?

    OpenAIRE

    Sean Pascoe; Chris Wilcox; C Josh Donlan

    2011-01-01

    The concept of biodiversity offsets is well established as an approach to environmental management. The concept has been suggested for environmental management in fisheries, particularly in relation to the substantial numbers of non-target species--seabirds in particular--caught and killed as incidental bycatch during fishing activities. Substantial areas of fisheries are being closed to protect these species at great cost to the fishing industry. However, other actions may be taken to offset...

  20. Combining Landscape-Level Conservation Planning and Biodiversity Offset Programs: A Case Study

    Science.gov (United States)

    Underwood, Jared G.

    2011-01-01

    Habitat loss is major factor in the endangerment and extinction of species around the world. One promising strategy to balance continued habitat loss and biodiversity conservation is that of biodiversity offsets. However, a major concern with offset programs is their consistency with landscape-level conservation goals. While merging offset polices and landscape-level conservation planning is thought to provide advantages over a traditional disconnected approach, few such landscape-level conservation-offset plans have been designed and implemented, so the effectiveness of such a strategy remains uncertain. In this study, we quantitatively assess the conservation impact of combining landscape-level conservation planning and biodiversity offset programs by comparing regions of San Diego County, USA with the combined approach to regions with only an offset program. This comparison is generally very difficult due to a variety of complicating factors. We overcome these complications and quantify the benefits to rare and threatened species of implementing a combined approach by assessing the amount of each species' predicted distribution, and the number of documented locations, conserved in comparison to the same metric for areas with an offset policy alone. We found that adoption of the combined approach has increased conservation for many rare species, often 5-10 times more than in the comparison area, and that conservation has been focused in the areas most important for these species. The level of conservation achieved reduces uncertainty that these species will persist in the region into the future. This San Diego County example demonstrates the potential benefits of combining landscape-level conservation planning and biodiversity offset programs.

  1. Species considerations in the design of biodiversity offset schemes in England

    OpenAIRE

    Howard, Bruce; Benmayor, Bex; Ausden, Malcolm; Butcher, Bill; Bull, Joe; Burrows, Larry; Chanin, Paul; Gent, Tony; Jowitt, Adrian; Mountford, Owen; Roy, David; Treweek, Jo; Jennings, Sarah

    2013-01-01

    On 16th September 2013, twelve ecologists met to evaluate how species can be given consideration in biodiversity offsets in the English context. They noted that while the type, area and distinctiveness of vegetation cover (‘habitat’) within a proposed development site is sometimes a useful basis for assessing likely impacts on individual species, this is not always the case. If biodiversity offsetting is to contribute towards a goal of ‘no net loss’ of biodiversity, assessment of the impacts ...

  2. Exact synthesis of offset multi-reflector antennas using dynamic and kinematic ray tracing

    Science.gov (United States)

    Kildal, P.-S.

    The equations and stepwise procedure of a new synthesis-by-ray tracing method is presented. The usefulness of the technique is demonstrated by synthesizing an offset dual-reflector antenna with low cross-polarization and an offset Gregorian dual-reflector feed for the spherical reflector antenna of the radio telescope in Arecibo. The synthesis method can be extended to synthesize contoured beams.

  3. Developing an Efficient Calibration System for Joint Offset of Industrial Robots

    OpenAIRE

    Bingtuan Gao; Yong Liu; Ning Xi; Yantao Shen

    2014-01-01

    Joint offset calibration is one of the most important methods to improve the positioning accuracy for industrial robots. This paper presents an efficient method to calibrate industrial robot joint offset. The proposed method mainly relies on a laser pointer mounted on the robot end-effector and a position sensitive device (PSD) located in the work space arbitrarily. A vision based control was employed to aid the laser beam shooting at the center of PSD surface from several initial robot p...

  4. Offset ancient city wall yields plausible slip rate for the Sagaing fault, Burma (Myanmar)

    Science.gov (United States)

    Wang, Y.; Aung, T.; Min, S.; Lin, K.; Tun, S.; Sieh, K.; Myint, U.

    2008-12-01

    The Sagaing fault offers great potential for paleoseismology study, because it traverses a region with a long history and high rates of sedimentation. Buddhist documents from ancient Pegu (Bago), in southern Myanmar, record 34 strong earthquakes in the past 2.3 millennia. The latest of these is the 1930 Pegu earthquake (M 7.3), which had high intensities along a 90 km stretch from Pegu to the southern coastline of the country. We have found evidences for surface rupture in 1930 in the stories of village elders and in offset paddy fields. These reports and offsets suggest that coseismic displacement decreased from several meters in Pegu to liquefaction without faulting near Payagyi Township, 15 km farther north. West of Payagyi, the fault trace cuts through and offsets an ancient city wall. The age of the ancient city is uncertain, but descriptions from Burmese history indicate it was built in the late 16th century, probably about 440 yrs ago. Determination of the offset of the 440-year-old city wall is possible, but not simple, in part because vertical displacements across the fault have resulted in differential sedimentation on the flanks of the wall. After accounting geomorphologically for the differential sedimentation, the offset of both the outer and inner edges of the city wall appear to have sustained a right-lateral offset of about 6 meters. This yields an approximate slip rate of 14 mm/yr, which is slightly lower than the slip rate determined by others from GPS geodesy. The number of earthquakes involved in creating the 6-meter offset is currently unknown, but paleoseismic excavations within the ancient city may well yield evidence of discrete offsets that we will be able to ascribe to specific large earthquakes in the historical record. Candidates include historical earthquakes 1582, 1644, 1768, 1830, 1888, 1913 and 1917 C.E.

  5. Pushing the limits of CAN - scheduling frames with offsets provides a major performance boost

    OpenAIRE

    Grenier, Mathieu; Havet, Lionel; Navet, Nicolas

    2008-01-01

    International audience With the increasing amount of electronics, making best usage of the bandwidth becomes of primary importance in automotive networks. One solution that is being investigated by car manufacturers is to schedule the messages with offsets, which leads to a desynchronization of the message streams. As it will be shown, this “traffic shaping” strategy is very beneficial in terms of worst-case response times. In this chapter, the problem of choosing the best offsets is addre...

  6. Statistically tuned Gaussian background subtraction technique for UAV videos

    Indian Academy of Sciences (India)

    R Athi Lingam; K Senthil Kumar

    2014-08-01

    Background subtraction is one of the efficient techniques to segment the targets from non-informative background of a video. The traditional background subtraction technique suits for videos with static background whereas the video obtained from unmanned aerial vehicle has dynamic background. Here, we propose an algorithm with tuning factor and Gaussian update for surveillance videos that suits effectively for aerial videos. The tuning factor is optimized by extracting the statistical features of the input frames.With the optimized tuning factor and Gaussian update an adaptive Gaussian-based background subtraction technique is proposed. The algorithm involves modelling, update and subtraction phases. This running Gaussian average based background subtraction technique uses updation at both model generation phase and subtraction phase. The resultant video extracts the moving objects from the dynamic background. Sample videos of various properties such as cluttered background, small objects, moving background and multiple objects are considered for evaluation. The technique is statistically compared with frame differencing technique, temporal median method and mixture of Gaussian model and performance evaluation is done to check the effectiveness of the proposed technique after optimization for both static and dynamic videos.

  7. Background subtraction theory and practice

    CERN Document Server

    Elgammal, Ahmed

    2014-01-01

    Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back

  8. Background correction in near-infrared spectra of plant extracts by orthogonal signal correction

    Institute of Scientific and Technical Information of China (English)

    QU Hai-bin; OU Dan-lin; CHENG Yi-yu

    2005-01-01

    In near-infrared (NIR) analysis of plant extracts, excessive background often exists in near-infrared spectra. The detection of active constituents is difficult because of excessive background, and correction of this problem remains difficult. In this work, the orthogonal signal correction (OSC) method was used to correct excessive background. The method was also compared with several classical background correction methods, such as offset correction, multiplicative scatter correction (MSC),standard normal variate (SNV) transformation, de-trending (DT), first derivative, second derivative and wavelet methods. A simulated dataset and a real NIR spectral dataset were used to test the efficiency of different background correction methods. The results showed that OSC is the only effective method for correcting excessive background.

  9. An improved offset generator developed for Allan deviation measurement of ultra stable frequency standards

    Science.gov (United States)

    Hamell, Robert L.; Kuhnle, Paul F.; Sydnor, Richard L.

    1992-01-01

    Measuring the performance of ultra stable frequency standards such as the Superconducting Cavity Maser Oscillator (SCMO) necessitates improvement of some test instrumentation. The frequency stability test equipment used at JPL includes a 1 Hz Offset Generator to generate a beat frequency between a pair of 100 MHz signals that are being compared. The noise floor of the measurement system using the current Offset Generator is adequate to characterize stability of hydrogen masers, but it is not adequate for the SCMO. A new Offset Generator with improved stability was designed and tested at JPL. With this Offset Generator and a new Zero Crossing Detector, recently developed at JPL, the measurement flow was reduced by a factor of 5.5 at 1 second tau, 3.0 at 1000 seconds, and 9.4 at 10,000 seconds, compared against the previous design. In addition to the new circuit designs of the Offset Generator and Zero Crossing Detector, tighter control of the measurement equipment environment was required to achieve this improvement. The design of this new Offset Generator are described, along with details of the environment control methods used.

  10. Study on axial offset oscillation for WWER-1000 reactor by using WWER-1000 simulator

    International Nuclear Information System (INIS)

    In the operation of thermal neutron reactors, it is known that the spatial xenon oscillations arise frequently. The nature of these oscillations is that almost of power concentrate just at a small region in the reactor core volume. The characteristic parameter for the axial power distribution is axial offset. In this subject, the cause of axial offset oscillation and its characteristics are studied. We investigate axial offset oscillation in begin of fuel cycle (BOC) and end of fuel cycle (EOC) of loading 1 enrichment and loading 5 enrichment for WWER-1000 reactor, using WWER-1000 reactor simulation program that was originally developed by IAEA. The results are: (1) the formation of axial offset oscillation is due to periodic deviation from an equilibrium distribution of iodine, xenon and neutron flux density between the upper half and the lower half of the reactor core, when the control group number 1 is inserted into the bottom of reactor core; (2) regarding the same fuel enrichment, in BOC, offset oscillates with larger amplitude and slower damping than in EOC. On the other hand, in higher fuel enrichment, offset oscillates with smaller amplitude and quicker damping than in lower fuel enrichment. (author)

  11. A framework for implementing biodiversity offsets: selecting sites and determining scale

    Science.gov (United States)

    Kiesecker, Joseph M.; Copeland, Holly; Pocewicz, Amy; Nibbelink, Nate; McKenney, Bruce; Dahlke, John; Holloran, Matthew J.; Stroud, Dan

    2009-01-01

    Biodiversity offsets provide a mechanism for maintaining or enhancing environmental values in situations where development is sought despite detrimental environmental impacts. They seek to ensure that unavoidable negative environmental impacts of development are balanced by environmental gains, with the overall aim of achieving a net neutral or positive outcome. Once the decision has been made to offset, multiple issues arise regarding how to do so in practice. A key concern is site selection. In light of the general aim to locate offsets close to the affected sites to ensure that benefits accrue in the same area, what is the appropriate spatial scale for identifying potential offset sites (e.g., local, ecoregional)? We use the Marxan site-selection algorithm to address conceptual and methodological challenges associated with identifying a set of potential offset sites and determining an appropriate spatial scale for them. To demonstrate this process, we examined the design of offsets for impacts from development on the Jonah natural gas field in Wyoming.

  12. Policy development for environmental licensing and biodiversity offsets in Latin America.

    Science.gov (United States)

    Villarroya, Ana; Barros, Ana Cristina; Kiesecker, Joseph

    2014-01-01

    Attempts to meet biodiversity goals through application of the mitigation hierarchy have gained wide traction globally with increased development of public policy, lending standards, and corporate practices. With interest in biodiversity offsets increasing in Latin America, we seek to strengthen the basis for policy development through a review of major environmental licensing policy frameworks in Argentina, Brazil, Chile, Colombia, Mexico, Peru and Venezuela. Here we focused our review on an examination of national level policies to evaluate to which degree current provisions promote positive environmental outcomes. All the surveyed countries have national-level Environmental Impact Assessment laws or regulations that cover the habitats present in their territories. Although most countries enable the use of offsets only Brazil, Colombia, Mexico and Peru explicitly require their implementation. Our review has shown that while advancing quite detailed offset policies, most countries do not seem to have strong requirements regarding impact avoidance. Despite this deficiency most countries have a strong foundation from which to develop policy for biodiversity offsets, but several issues require further guidance, including how best to: (1) ensure conformance with the mitigation hierarchy; (2) identify the most environmentally preferable offsets within a landscape context; (3) determine appropriate mitigation replacement ratios; and (4) ensure appropriate time and effort is given to monitor offset performance. PMID:25191758

  13. Policy development for environmental licensing and biodiversity offsets in Latin America.

    Directory of Open Access Journals (Sweden)

    Ana Villarroya

    Full Text Available Attempts to meet biodiversity goals through application of the mitigation hierarchy have gained wide traction globally with increased development of public policy, lending standards, and corporate practices. With interest in biodiversity offsets increasing in Latin America, we seek to strengthen the basis for policy development through a review of major environmental licensing policy frameworks in Argentina, Brazil, Chile, Colombia, Mexico, Peru and Venezuela. Here we focused our review on an examination of national level policies to evaluate to which degree current provisions promote positive environmental outcomes. All the surveyed countries have national-level Environmental Impact Assessment laws or regulations that cover the habitats present in their territories. Although most countries enable the use of offsets only Brazil, Colombia, Mexico and Peru explicitly require their implementation. Our review has shown that while advancing quite detailed offset policies, most countries do not seem to have strong requirements regarding impact avoidance. Despite this deficiency most countries have a strong foundation from which to develop policy for biodiversity offsets, but several issues require further guidance, including how best to: (1 ensure conformance with the mitigation hierarchy; (2 identify the most environmentally preferable offsets within a landscape context; (3 determine appropriate mitigation replacement ratios; and (4 ensure appropriate time and effort is given to monitor offset performance.

  14. Policy development for environmental licensing and biodiversity offsets in Latin America.

    Science.gov (United States)

    Villarroya, Ana; Barros, Ana Cristina; Kiesecker, Joseph

    2014-01-01

    Attempts to meet biodiversity goals through application of the mitigation hierarchy have gained wide traction globally with increased development of public policy, lending standards, and corporate practices. With interest in biodiversity offsets increasing in Latin America, we seek to strengthen the basis for policy development through a review of major environmental licensing policy frameworks in Argentina, Brazil, Chile, Colombia, Mexico, Peru and Venezuela. Here we focused our review on an examination of national level policies to evaluate to which degree current provisions promote positive environmental outcomes. All the surveyed countries have national-level Environmental Impact Assessment laws or regulations that cover the habitats present in their territories. Although most countries enable the use of offsets only Brazil, Colombia, Mexico and Peru explicitly require their implementation. Our review has shown that while advancing quite detailed offset policies, most countries do not seem to have strong requirements regarding impact avoidance. Despite this deficiency most countries have a strong foundation from which to develop policy for biodiversity offsets, but several issues require further guidance, including how best to: (1) ensure conformance with the mitigation hierarchy; (2) identify the most environmentally preferable offsets within a landscape context; (3) determine appropriate mitigation replacement ratios; and (4) ensure appropriate time and effort is given to monitor offset performance.

  15. Investigation of Maximum Blade Loading Capability of Lift-Offset Rotors

    Science.gov (United States)

    Yeo, Hyeonsoo; Johnson, Wayne

    2013-01-01

    Maximum blade loading capability of a coaxial, lift-offset rotor is investigated using a rotorcraft configuration designed in the context of short-haul, medium-size civil and military missions. The aircraft was sized for a 6600-lb payload and a range of 300 nm. The rotor planform and twist were optimized for hover and cruise performance. For the present rotor performance calculations, the collective pitch angle is progressively increased up to and through stall with the shaft angle set to zero. The effects of lift offset on rotor lift, power, controls, and blade airloads and structural loads are examined. The maximum lift capability of the coaxial rotor increases as lift offset increases and extends well beyond the McHugh lift boundary as the lift potential of the advancing blades are fully realized. A parametric study is conducted to examine the differences between the present coaxial rotor and the McHugh rotor in terms of maximum lift capabilities and to identify important design parameters that define the maximum lift capability of the rotor. The effects of lift offset on rotor blade airloads and structural loads are also investigated. Flap bending moment increases substantially as lift offset increases to carry the hub roll moment even at low collective values. The magnitude of flap bending moment is dictated by the lift-offset value (hub roll moment) but is less sensitive to collective and speed.

  16. Sample application to test site No. 1, Kenedy Co. [Offset well information, drilling fluids program, cost estimates, and data acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Podio, A.L.; Gray, K.E.; Isokrari, O.F.; Knapp, R.M.; Silberberg, I.H.; Thompson, T.W.

    1976-01-01

    In order to satisfy the objective of outlining the preliminary plan and schedules as well as obtaining representative costs for drilling a geopressured geothermal well the guidelines have been applied to one of the possible test sites identified by the Resource Assessment Phase I of the project. The specific site is the Armstrong lease in the Candelaria Field in Kenedy County, Texas. Offset well information including bit records, drilling fluid programs, formation pressure encountered and casing programs for the Armstrong No. 20 and No. 22 wells are presented. Based on this information a preliminary drilling program has been prepared. Well completion and production considerations were taken into account in the preparation of the drilling program. A brief description of drilling operations is also included to clarify the terminology used.

  17. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples

  18. Strings in pp-wave background and background B-field from membrane and its symplectic quantization

    International Nuclear Information System (INIS)

    The symplectic quantization technique is applied to open free membrane and strings in pp-wave background and background gauge field obtained by compactifying the open membrane in the presence of a background anti-symmetric 3-form field. In both cases, first the Poisson brackets among the Fourier modes are obtained and then the Poisson brackets among the membrane (string) coordinates are computed. The full non-commutative phase-space structure is reproduced in case of strings in pp-wave background and background gauge field. We feel that this method of obtaining the Poisson algebra is more elegant than previous approaches discussed in the literature

  19. Air quality and Atmospheric resources: Phase 1: Background document

    International Nuclear Information System (INIS)

    The Environment and Sustainable Development Indicators (ESDI) initiative, under the umbrella of the National Round Table on the Environment and the Economy (NRTEE), commissioned a study for the evaluation and the development of sustainable development indicators (SDIs) in the field of air quality and atmospheric resources. The report contained key information with regard to each indicator or indicator set, and no comprehensive comparative analysis was performed. The report was designed to be used as a technical reference. Where appropriate, SDIs developed by foreign organizations were included. The emphasis of the report was: (1) ambient air quality and human health effects, (2) air emissions having transboundary or global implications for ecosystem health and human health, and (3) demand on the atmosphere for environmental services. The bulk of the research was conducted on the Internet. The report was divided into three sections. A review of the availability of SDIs based on ambient air quality measures was discussed in the first section, while the second section was devoted to the availability of SDIs based on pollutant emission levels. The last section contained a systematic review of those SDIs used or being proposed along with the supporting data available to calculate SDI values. Some observations were also made touching on topics such as the abundance of ambient air quality information, the abundance of pollutant emissions information, the linkages between emissions and ambient air quality, the absence of forecasting, the indoor air quality gap, and the connections to human health. refs., 1 fig

  20. Cosmological Backgrounds of Gravitational Waves and eLISA

    CERN Document Server

    Dufaux, Jean-Francois

    2012-01-01

    We review cosmological backgrounds of gravitational waves with a particular attention to the scientific potential of the eLISA/NGO mission. After an overview of cosmological backgrounds and detectors, we consider different cosmological sources that could lead to an observable signal. We then study the backgrounds produced by first-order phase transitions and networks of cosmic strings, assessing the prospects for their detection.

  1. The Nature of Active Galactic Nuclei with Velocity Offset Emission Lines

    Science.gov (United States)

    Müller-Sánchez, F.; Comerford, J.; Stern, D.; Harrison, F. A.

    2016-10-01

    We obtained Keck/OSIRIS near-IR adaptive optics-assisted integral-field spectroscopy to probe the morphology and kinematics of the ionized gas in four velocity-offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey. These objects possess optical emission lines that are offset in velocity from systemic as measured from stellar absorption features. At a resolution of ∼0.″18, OSIRIS allows us to distinguish which velocity offset emission lines are produced by the motion of an AGN in a dual supermassive black hole system, and which are produced by outflows or other kinematic structures. In three galaxies, J1018+2941, J1055+1520, and J1346+5228, the spectral offset of the emission lines is caused by AGN-driven outflows. In the remaining galaxy, J1117+6140, a counterrotating nuclear disk is observed that contains the peak of Paα emission 0.″2 from the center of the galaxy. The most plausible explanation for the origin of this spatially and kinematically offset peak is that it is a region of enhanced Paα emission located at the intersection zone between the nuclear disk and the bar of the galaxy. In all four objects, the peak of ionized gas emission is not spatially coincident with the center of the galaxy as traced by the peak of the near-IR continuum emission. The peaks of ionized gas emission are spatially offset from the galaxy centers by 0.″1–0.″4 (0.1–0.7 kpc). We find that the velocity offset originates at the location of this peak of emission, and the value of the offset can be directly measured in the velocity maps. The emission-line ratios of these four velocity-offset AGNs can be reproduced only with a mixture of shocks and AGN photoionization. Shocks provide a natural explanation for the origin of the spatially and spectrally offset peaks of ionized gas emission in these galaxies. Based on observations at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the

  2. Surface speed and frontal ablation of Kronebreen and Kongsbreen, NW-Svalbard, from SAR offset tracking

    Directory of Open Access Journals (Sweden)

    T. Schellenberger

    2014-12-01

    Full Text Available Kronebreen and Kongsbreen are among the fastest flowing glaciers on Svalbard, and therefore important contributors to glacier mass loss from the archipelago through frontal ablation. Here, we present a time series of area-wide surface velocity fields from April 2012 to December 2013 based on offset tracking on repeat high-resolution Radarsat-2 Ultrafine data. Surface speeds reached up to 3.2 m d−1 near the calving front of Kronebreen in summer 2013 and 2.7 m d−1 at Kongsbreen in late autumn 2012. Additional velocity fields from Radarsat-1, Radarsat-2 and TerraSAR-X data since December 2007 together with continuous GPS measurements on Kronebreen since September 2008 revealed complex patterns in seasonal and interannual speed evolution. Part of the ice-flow variations seem closely linked to the amount and timing of surface melt water production and rainfall, both of which are known to have a strong influence on the basal water pressure and lubrication. In addition, terminus retreat and the associated reduction in backstress appear to have influenced the speed close to the calving front, especially at Kongsbreen in 2012 and 2013. Since 2007, Kongsbreen retreated up to 1800 m, corresponding to a total area loss of 2.5 km2. In 2011 the retreat of Kronebreen of up to 850 m, responsible for a total area loss of 2.8 km2, was triggered after a phase of stable terminus position since ~1990. The retreat is an important component of the mass balance of both glaciers, in which frontal ablation is the largest component. Total frontal ablation between April 2012 and December 2013 was estimated to 0.21–0.25 Gt a−1 for Kronebreen and 0.14–0.16 Gt a−1 for Kongsbreen.

  3. A novel tuning approach for offset-free MPC

    DEFF Research Database (Denmark)

    Waschl, Harald; Jørgensen, John Bagterp; Huusom, Jakob Kjøbsted;

    2015-01-01

    Since the beginnings in the chemical and process industry, model based predictive control strategies have become widely accepted. Often mentioned success factors for MPC are the use of optimization based on a plant model, the consideration of constraints, and an intuitive tuning. Indeed, if a nom......Since the beginnings in the chemical and process industry, model based predictive control strategies have become widely accepted. Often mentioned success factors for MPC are the use of optimization based on a plant model, the consideration of constraints, and an intuitive tuning. Indeed......, if a nominal plant and overall objective are known, the tuning can become straightforward. However, as soon as disturbances have to be taken into account, the tuning effort increases and becomes less intuitive. Against this background, a novel strategy to address the issues with unknown disturbances...

  4. Cosmic Microwave Background Data Analysis

    Science.gov (United States)

    Paykari, Paniez; Starck, Jean-Luc Starck

    2012-03-01

    that the highest power fluctuations occur at scales of about one degree. A number of ground-based interferometers provided measurements of the fluctuations with higher accuracy over the next three years, including the Very Small Array [16], Degree Angular Scale Interferometer (DASI) [61], and the Cosmic Background Imager (CBI) [78]. DASI was the first to detect the polarization of the CMB and the CBI provided the first E-mode polarization spectrum with compelling evidence that it is out of phase with the T-mode spectrum. In June 2001, NASA launched its second CMB mission (after COBE), Wilkinson Microwave Anisotropy Explorer (WMAP) [44], to make much more precise measurements of the CMB sky. WMAP measured the differences in the CMB temperature across the sky creating a full-sky map of the CMB in five different frequency bands. The mission also measured the CMB's E-mode and the foreground polarization. As of October 2010, the WMAP spacecraft has ended its mission after nine years of operation. Although WMAP provided very accurate measurements of the large angular-scale fluctuations in the CMB, it did not have the angular resolution to cover the smaller-scale fluctuations that had been observed by previous ground-based interferometers. A third space mission, the Planck Surveyor [1], was launched by ESA* in May 2009 to measure the CMB on smaller scales than WMAP, as well as making precise measurements of the polarization of CMB. Planck represents an advance over WMAP in several respects: it observes in higher resolution, hence allowing one to probe the CMB power spectrum to smaller scales; it has a higher sensitivity and observes in nine frequency bands rather than five, hence improving the astrophysical foreground models. The mission has a wide variety of scientific aims, including: (1) detecting the total intensity/polarization of the primordial CMB anisotropies; (2) creating a galaxy-cluster catalogue through the Sunyaev-Zel'dovich (SZ) effect [93]; (3) observing the

  5. Validation of meter-scale surface faulting offset measurements from high-resolution topographic data

    Science.gov (United States)

    Salisbury, Barrett; Haddad, D.E.; Rockwell, T.K.; Arrowsmith, R.; Madugo, C.; Zielke, O.; Scharer, Katherine M.

    2015-01-01

    Studies of active fault zones have flourished with the availability of high-resolution topographic data, particularly where airborne light detection and ranging (lidar) and structure from motion (SfM) data sets provide a means to remotely analyze submeter-scale fault geomorphology. To determine surface offset at a point along a strike-slip earthquake rupture, geomorphic features (e.g., stream channels) are measured days to centuries after the event. Analysis of these and cumulatively offset features produces offset distributions for successive earthquakes that are used to understand earthquake rupture behavior. As researchers expand studies to more varied terrain types, climates, and vegetation regimes, there is an increasing need to standardize and uniformly validate measurements of tectonically displaced geomorphic features. A recently compiled catalog of nearly 5000 earthquake offsets across a range of measurement and reporting styles provides insight into quality rating and uncertainty trends from which we formulate best-practice and reporting recommendations for remote studies. In addition, a series of public and beginner-level studies validate the remote methodology for a number of tools and emphasize considerations to enhance measurement accuracy and precision for beginners and professionals. Our investigation revealed that (1) standardizing remote measurement methods and reporting quality rating schemes is essential for the utility and repeatability of fault-offset measurements; (2) measurement discrepancies often involve misinterpretation of the offset geomorphic feature and are a function of the investigator’s experience; (3) comparison of measurements made by a single investigator in different climatic regions reveals systematic differences in measurement uncertainties attributable to variation in feature preservation; (4) measuring more components of a displaced geomorphic landform produces more consistently repeatable estimates of offset; and (5

  6. High Octane Fuel: Terminal Backgrounder

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Kristi [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-11

    The Bioenergy Technologies Office of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy sponsored a scoping study to assess the potential of ethanol-based high octane fuel (HOF) to reduce energy consumption and greenhouse gas emissions. When the HOF blend is made with 25%-40% ethanol by volume, this energy efficiency improvement is potentially sufficient to offset the reduced vehicle range often associated with the decreased volumetric energy density of ethanol. The purpose of this study is to assess the ability of the fuel supply chain to accommodate more ethanol at fuel terminals. Fuel terminals are midstream in the transportation fuel supply chain and serve to store and distribute fuels to end users. While there are no technical issues to storing more ethanol at fuel terminals, there are several factors that could impact the ability to deploy more ethanol. The most significant of these issues include the availability of land to add more infrastructure and accommodate more truck traffic for ethanol deliveries as well as a lengthy permitting process to erect more tanks.

  7. The Cosmic Microwave Background anisotropies: open problems

    CERN Document Server

    Martínez-González, E

    2005-01-01

    The standard inflationary model presents a simple scenario within which the homogeneity, isotropy and flatness of the universe appear as natural outcomes and, in addition, fluctuations in the energy density are originated during the inflationary phase. These seminal density fluctuations give rise to fluctuations in the temperature of the Cosmic Microwave Background (CMB) at the decoupling surface. Afterward, the CMB photons propagate almost freely, with slight gravitational interactions with the evolving gravitational field present in the large scale structure (LSS) of the matter distribution and a low scattering rate with free electrons after the universe becomes reionized. These secondary effects slightly change the shape of the intensity and polarization angular power spectra (APS) of the radiation. The APS contain very valuable information on the parameters characterizing the background model of the universe and those parametrising the power spectra of both matter density perturbations and gravitational w...

  8. Generalized Background-Field Method

    CERN Document Server

    Feng, Y J

    1997-01-01

    The graphical method discussed previously can be used to create new gauges not reachable by the path-integral formalism. By this means a new gauge is designed for more efficient two-loop QCD calculations. It is related to but simpler than the ordinary background-field gauge, in that even the triple-gluon vertices for internal lines contain only four terms, not the usual six. This reduction simplifies the calculation inspite of the necessity to include other vertices for compensation. Like the ordinary background-field gauge, this generalized background-field gauge also preserves gauge invariance of the external particles. As a check of the result and an illustration for the reduction in labour, an explicit calculation of the two-loop QCD 45% of computation compared to the ordinary background-field gauge.

  9. Geometrodynamics on a background spacetime

    CERN Document Server

    Papadopoulos, P P; Papadopoulos, Philippos; Sopuerta, Carlos F.

    2001-01-01

    The formulation of the initial value problem for the Einstein equations is at the heart of obtaining interesting new solutions using numerical relativity and still very much under theoretical and applied scrutiny. We develop a specialised background geometry approach, for systems where there is non-trivial a priori knowledge about the spacetime under study. The background three-geometry and associated connection are used to express the ADM evolution equations in terms of physical non-linear deviations from that background. Expressing the equations in first order form leads naturally to a system closely linked to the Einstein-Christoffel system, introduced by Anderson and York, and sharing its hyperbolicity properties. The background metric approach can drastically alter the source structure of the equations, and we present an argument as to why this is likely to be numerically advantageous.

  10. Backgrounds in AFP Detector Estimation

    CERN Document Server

    Huang, Yicong

    2016-01-01

    The ATLAS Forward Proton (AFP) detectors aim to measure protons that are scattered in the ATLAS interaction point under very small angles ($90-160 \\mu rad$). The diffractive protons detected by the AFP may be accompanied by beam halo. This report presents an estimation of the beam halo backgrounds in the AFP using low pile-up data, and position distributions of the backgrounds in the AFP.

  11. First investigation of the noise and modulation properties of the carrier-envelope offset in a modelocked semiconductor laser.

    Science.gov (United States)

    Brochard, Pierre; Jornod, Nayara; Schilt, Stéphane; Wittwer, Valentin J; Hakobyan, Sargis; Waldburger, Dominik; Link, Sandro M; Alfieri, Cesare G E; Golling, Matthias; Devenoges, Laurent; Morel, Jacques; Keller, Ursula; Südmeyer, Thomas

    2016-07-15

    We present the first characterization of the noise properties and modulation response of the carrier-envelope offset (CEO) frequency in a semiconductor modelocked laser. The CEO beat of an optically-pumped vertical external-cavity surface-emitting laser (VECSEL) at 1030 nm was characterized without standard f-to-2f interferometry. Instead, we used an appropriate combination of signals obtained from the modelocked oscillator and an auxiliary continuous-wave laser to extract information about the CEO signal. The estimated linewidth of the free-running CEO beat is approximately 1.5 MHz at 1-s observation time, and the feedback bandwidth to enable a tight CEO phase lock to be achieved in a future stabilization loop is in the order of 300 kHz. We also characterized the amplitude and phase of the pump current to CEO-frequency transfer function, which showed a 3-dB bandwidth of ∼300  kHz for the CEO frequency modulation. This fulfills the estimated required bandwidth and indicates that the first self-referenced phase-stabilization of a modelocked semiconductor laser should be feasible in the near future. PMID:27420486

  12. Carbon Offsets in California: What Role for Earth Scientists in the Policy Process? (Invited)

    Science.gov (United States)

    Cullenward, D.; Strong, A. L.

    2013-12-01

    This talk addresses the policy structure in California for developing and approving carbon offset protocols, which rely on findings from the environmental and earth sciences communities. In addition to providing an overview of the legal requirements of carbon offsets, we describe a series of case studies of how scientists can engage with policymakers. Based on those experiences, we suggest ways for the earth sciences community to become more involved in climate policy development. California's climate law, known as AB 32, requires that major sectors of the state's economy reduce their emissions to 1990 levels by 2020. As part of AB 32, the California Air Resources Board created a cap-and-trade market to ensure compliance with the statutory target. Under this system, regulated companies have to acquire tradable emissions permits (called 'compliance instruments') for the greenhouse gas emissions they release. The State allocates a certain number of allowances to regulated entities through a mixture of auctions and free transfers, with the total number equal to the overall emissions target; these allowances, along with approved offsets credits, are the compliance instruments that regulated entities are required to obtain by law. One of the key policy design issues in California's cap-and-trade market concerns the use of carbon offsets. Under AB 32, the Air Resources Board can issue offset credits to project developers who reduce emissions outside of the capped sectors (electricity, industry, and transportation)--or even outside of California--pursuant to approved offset protocols. Project developers then sell the credits to regulated companies in California. Essentially, offsets allow regulated entities in California to earn credit for emissions reductions that take place outside the scope of AB 32. Many regulated entities and economists are in favor of offsets because they view them as a source of low-cost compliance instruments. On the other hand, critics argue that

  13. SU-E-J-259: Quantification of Rotational Localization Offset in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Nguyen, N; Lee, S; Liu, F [Rhode Island Hospital / Warren Alpert Medical, Providence, RI (United States)

    2014-06-01

    Purpose: To verify the necessity of 6D localization detection and correction in radiation therapy. Methods: An anthropomorphic head and neck phantom was used to test the BrainLab ExacTrac x-ray imaging system. After initial positioning, both ExacTrac and the on-board kV CBCT were used to detect the offset at the same position, using both manual and automatic registration algorithms. Then 6D offset including rotational errors up to 5 degree were introduced. Both ExacTrac and CBCT were used to correct the offsets and the residual errors were evaluated. Finally, 6D offset detected by ExacTrac for a C-Spine patient was reported. Results: The differences in 3D offset detected by ExacTrac and CBCT were 1.5 ± 1.2(Lateral), 2.7 ± 2.7(Vertical), and 4.0 ± 6.3(longitudinal) mm with manual registration while the corresponding differences decreased to 0.6 ± 0.3, 1.0 ± 0.3, and 0.3 ± 0.3 when automatic registration were used. CBCT corrected the translational offset to within 0.5 mm but the rotational errors remained and detected by the ExacTrac system (Yaw=2.1, Roll=1.1, Pitch=1.4 degree). When similar offset was introduced and corrected using ExacTrac, the residual error detected by both CBCT and ExacTrac were within 0.5 mm / 0.5 degree. The average offset from the 112 ExacTrac x-ray corrections for the C-Spine patient was 0.6 ± 1.6 (lateral), 5.4 ± 8(vertical), 1.6±1.1(longitudinal) mm, and 0.7 ± 0.6 (pitch), 0.7 ± 0.4(roll), 1.2 ± 0.7 (yaw) degree. Larger rotational errors, with a maximum of 2.7 degree (corresponds to about 1.5 to 4.5 mm offset for a POI 10 to 30 cm away from the isocenter), were observed when couch rotational were involved. Conclusion: Rotational errors are common in patient localization, especially when couch rotation is involved. Both appropriate imaging system and 6D robotic couch are necessary to detect and correct the rotational localization errors.

  14. Numerical Investigation of Nozzle Geometry Effect on Turbulent 3-D Water Offset Jet Flows

    Directory of Open Access Journals (Sweden)

    Negar Mohammad Aliha

    2016-01-01

    Full Text Available Using the Yang-Shih low Reynolds k-ε turbulence model, the mean flow field of a turbulent offset jet issuing from a long circular pipe was numerically investigated. The experimental results were used to verify the numerical results such as decay rate of streamwise velocity, locus of maximum streamwise velocity, jet half width in the wall normal and lateral directions, and jet velocity profiles. The present study focused attention on the influence of nozzle geometry on the evolution of a 3D incompressible turbulent offset jet. Circular, square-shaped, and rectangular nozzles were considered here. A comparison between the mean flow characteristics of offset jets issuing from circular and square-shaped nozzles, which had equal area and mean exit velocity, were made numerically. Moreover, the effect of aspect ratio of rectangular nozzles on the main features of the flow was investigated. It was shown that the spread rate, flow entrainment, and mixing rate of an offset jet issuing from circular nozzle are lower than square-shaped one. In addition, it was demonstrated that the aspect ratio of the rectangular nozzles only affects the mean flow field of the offset jet in the near field (up to 15 times greater than equivalent diameter of the nozzles. Furthermore, other parameters including the wall shear stress, flow entrainment and the length of potential core were also investigated.

  15. Lateral wave-field stacking of seismic Fresnel zones for the generalized-offset case

    Science.gov (United States)

    Tian, Nan; Fan, Ting-En; Wang, Zong-Jun; Cai, Wen-Tao

    2015-06-01

    To unify different seismic geometries, the concept of generalized offset is defined and the expressions for Fresnel zones of different order on a plane are presented. Based on wave theory, the equation of the lateral wave-field stacking for generalized-offset Fresnel zones is derived. For zero and nonzero offsets, the lateral stacking amplitude of diffraction bins of different sizes is analyzed by referring to the shape of the Fresnel zones of different order. The results suggest the following. First, the contribution of diffraction bins to wave-field stacking is related to the offset, surface relief, interface dip, the depth of the shot point to the reflection interface, the observational geometry, and the size of the interference stacking region. Second, the first-order Fresnel zone is the main constructive interference, and its contribution to the reflection amplitude is slightly smaller than half the contribution of all Fresnel zones. Finally, when the size of the diffraction bin is smaller than the first-order Fresnel zone, the larger the size of the diffraction bin, the larger is the amplitude of the receiver, even in the nonzero offset-case.

  16. Offset-Free Model Predictive Control of Open Water Channel Based on Moving Horizon Estimation

    Science.gov (United States)

    Ekin Aydin, Boran; Rutten, Martine

    2016-04-01

    Model predictive control (MPC) is a powerful control option which is increasingly used by operational water managers for managing water systems. The explicit consideration of constraints and multi-objective management are important features of MPC. However, due to the water loss in open water systems by seepage, leakage and evaporation a mismatch between the model and the real system will be created. These mismatch affects the performance of MPC and creates an offset from the reference set point of the water level. We present model predictive control based on moving horizon estimation (MHE-MPC) to achieve offset free control of water level for open water canals. MHE-MPC uses the past predictions of the model and the past measurements of the system to estimate unknown disturbances and the offset in the controlled water level is systematically removed. We numerically tested MHE-MPC on an accurate hydro-dynamic model of the laboratory canal UPC-PAC located in Barcelona. In addition, we also used well known disturbance modeling offset free control scheme for the same test case. Simulation experiments on a single canal reach show that MHE-MPC outperforms disturbance modeling offset free control scheme.

  17. Increased tone-offset response in the lateral nucleus of the amygdala underlies trace fear conditioning.

    Science.gov (United States)

    Kim, Namsoo; Kong, Mi-Seon; Jo, Kyeong Im; Kim, Eun Joo; Choi, June-Seek

    2015-12-01

    Accumulating evidence suggests that the lateral nucleus of the amygdala (LA) stores associative memory in the form of enhanced neural response to the sensory input following classical fear conditioning in which the conditioned stimulus (CS) and the unconditioned stimulus (US) are presented in a temporally continuous manner. However, little is known about the role of the LA in trace fear conditioning where the CS and the US are separated by a temporal gap. Single-unit recordings of LA neurons before and after trace fear conditioning revealed that the short-latency activity to the CS offset, but not that to the onset, increased significantly and accompanied the conditioned fear response. The increased short-latency activity was evident in two aspects: the number of offset-responsive neurons was increased and the latency of the neuronal response to the CS offset was shortened. On the contrary, changes in the firing rate to either the onset or the offset were negligible following unpaired presentations of the CS and US. In sum, our results suggest that increased synaptic efficacy in the CS offset pathway in the LA might underlie the association between temporally distant stimuli in trace fear conditioning.

  18. Valence band offsets at Cu(In,Ga)Se{sub 2}/Zn(O,S) interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Tobias; Klein, Andreas [Surface Science Division, Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstrasse 32, 64287, Darmstadt (Germany); Botros, Miriam [Surface Science Division, Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstrasse 32, 64287, Darmstadt (Germany); Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Industriestrasse 6, 70565, Stuttgart (Germany); Witte, Wolfram; Hariskos, Dimitrios; Menner, Richard; Powalla, Michael [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Industriestrasse 6, 70565, Stuttgart (Germany)

    2014-09-15

    The energy band alignment at interfaces between Cu-chalcopyrites and Zn(O,S) buffer layers, which are important for thin-film solar cells, are considered. Valence band offsets derived from X-ray photoelectron spectroscopy for Cu(In,Ga)Se{sub 2} absorber layers with CdS and Zn(O,S) compounds are compared to theoretical predictions. It is shown that the valence band offsets at Cu(In,Ga)Se{sub 2}/Zn(O,S) interfaces approximately follow the theoretical prediction and vary significantly from sample to sample. The integral sulfide content of chemical bath deposited Zn(O,S) is reproducibly found to be 50-70%, fortuitously resulting in a conduction band offset suitable for solar cell applications with Cu(In,Ga)Se{sub 2} absorber materials. The observed variation in offset can neither be explained by variation of the Cu content in the Cu(In,Ga)Se{sub 2} near the interface nor by local variation of the chemical composition. Fermi level pinning induced by high defect concentrations is a possible origin of the variation of band offset. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. The potential for biodiversity offsetting to fund effective invasive species control.

    Science.gov (United States)

    Norton, David A; Warburton, Bruce

    2015-02-01

    Compensating for biodiversity losses in 1 location by conserving or restoring biodiversity elsewhere (i.e., biodiversity offsetting) is being used increasingly to compensate for biodiversity losses resulting from development. We considered whether a form of biodiversity offsetting, enhancement offsetting (i.e., enhancing the quality of degraded natural habitats through intensive ecological management), can realistically secure additional funding to control biological invaders at a scale and duration that results in enhanced biodiversity outcomes. We suggest that biodiversity offsetting has the potential to enhance biodiversity values through funding of invasive species control, but it needs to meet 7 key conditions: be technically possible to reduce invasive species to levels that enhance native biodiversity; be affordable; be sufficiently large to compensate for the impact; be adaptable to accommodate new strategic and tactical developments while not compromising biodiversity outcomes; acknowledge uncertainties associated with managing pests; be based on an explicit risk assessment that identifies the cost of not achieving target outcomes; and include financial mechanisms to provide for in-perpetuity funding. The challenge then for conservation practitioners, advocates, and policy makers is to develop frameworks that allow for durable and effective partnerships with developers to realize the full potential of enhancement offsets, which will require a shift away from traditional preservation-focused approaches to biodiversity management.

  20. Determination of Flux-Gate Magnetometer Spin Axis Offsets with the Electron Drift Instrument

    Science.gov (United States)

    Plaschke, Ferdinand; Nakamura, Rumi; Giner, Lukas; Teubenbacher, Robert; Chutter, Mark; Leinweber, Hannes K.; Magnes, Werner

    2014-05-01

    Spin-stabilization of spacecraft enormously supports the in-flight calibration of onboard flux-gate magnetometers (FGMs): eight out of twelve calibration parameters can be determined by minimization of spin tone and harmonics in the calibrated magnetic field measurements. From the remaining four parameters, the spin axis offset is usually obtained by analyzing observations of Alfvénic fluctuations in the solar wind. If solar wind measurements are unavailable, other methods for spin axis offset determination need to be used. We present two alternative methods that are based on the comparison of FGM and electron drift instrument (EDI) data: (1) EDI measures the gyration periods of instrument-emitted electrons in the ambient magnetic field. They are inversely proportional to the magnetic field strength. Differences between FGM and EDI measured field strengths can be attributed to inaccuracies in spin axis offset, if the other calibration parameters are accurately known. (2) For EDI electrons to return to the spacecraft, they have to be sent out in perpendicular direction to the ambient magnetic field. Minimization of the variance of electron beam directions with respect to the FGM-determined magnetic field direction also yields an estimate of the spin axis offset. Prior to spin axis offset determination, systematic inaccuracies in EDI gyration period measurements and in the transformation of EDI beam directions into the FGM spin-aligned reference coordinate system have to be corrected. We show how this can be done by FGM/EDI data comparison, as well.

  1. Echoic memory: investigation of its temporal resolution by auditory offset cortical responses.

    Directory of Open Access Journals (Sweden)

    Makoto Nishihara

    Full Text Available Previous studies showed that the amplitude and latency of the auditory offset cortical response depended on the history of the sound, which implicated the involvement of echoic memory in shaping a response. When a brief sound was repeated, the latency of the offset response depended precisely on the frequency of the repeat, indicating that the brain recognized the timing of the offset by using information on the repeat frequency stored in memory. In the present study, we investigated the temporal resolution of sensory storage by measuring auditory offset responses with magnetoencephalography (MEG. The offset of a train of clicks for 1 s elicited a clear magnetic response at approximately 60 ms (Off-P50m. The latency of Off-P50m depended on the inter-stimulus interval (ISI of the click train, which was the longest at 40 ms (25 Hz and became shorter with shorter ISIs (2.5∼20 ms. The correlation coefficient r2 for the peak latency and ISI was as high as 0.99, which suggested that sensory storage for the stimulation frequency accurately determined the Off-P50m latency. Statistical analysis revealed that the latency of all pairs, except for that between 200 and 400 Hz, was significantly different, indicating the very high temporal resolution of sensory storage at approximately 5 ms.

  2. The Nature of Active Galactic Nuclei with Velocity Offset Emission Lines

    CERN Document Server

    Müller-Sánchez, Francisco; Stern, Daniel; Harrison, Fiona A

    2016-01-01

    We obtained Keck/OSIRIS near-IR adaptive optics-assisted integral-field spectroscopy to probe the morphology and kinematics of the ionized gas in four velocity-offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey. These objects possess optical emission lines that are offset in velocity from systemic as measured from stellar absorption features. At a resolution of ~0.18", OSIRIS allows us to distinguish which velocity offset emission lines are produced by the motion of an AGN in a dual supermassive black hole system, and which are produced by outflows or other kinematic structures. In three galaxies, J1018+2941, J1055+1520 and J1346+5228, the spectral offset of the emission lines is caused by AGN-driven outflows. In the remaining galaxy, J1117+6140, a counterrotating nuclear disk is observed that contains the peak of Pa$\\alpha$ emission 0.2" from the center of the galaxy. The most plausible explanation for the origin of this spatially and kinematically offset peak is that it is a region of en...

  3. ESTIMATION OF CARRIER FREQUENCY OFFSETS FOR MIMO SYSTEMS WITH DISTRIBUTED TRANSMIT ANTENNAS

    Institute of Scientific and Technical Information of China (English)

    Deng Kai; Tang Youxi; Lei Xia; Li Shaoqian

    2007-01-01

    The problem of estimating the carrier frequency offsets in Multiple-Input Multiple-Output (MIMO) systems with distributed transmit antennas is addressed. It is supposed that the transmit antennas are distributed while the receive antennas are still centralized, and the general case where both the time delays and the frequency offsets are possibly different for each transmit antenna is considered. The channel is supposed to be frequency flat, and the macroscopic fading is also taken into consideration. A carrier frequency offset estimator based on Maximum Likelihood (ML) is proposed,which can separately estimate the frequency offset for each transmit antenna and exploit the spatial diversity. The Cramer-Rao Bound (CRB) for synchronous MIMO (i.e., the time delays for each transmit antenna are all equal) is also derived. Simulation results are given to illustrate the performance of the estimator and compare it with the CRB. It is shown that the estimator can provide satisfactory frequency offset estimates and its performance is close to the CRB for the Signal-to-Noise Ratio (SNR) below 20dB.

  4. Effect of the Carrier-Envelope-Offset Dynamics on the Stabilization of a Diode-Pumped Solid-State Frequency Comb

    OpenAIRE

    Bucalovic, Nikola; Dolgovskiy, Vladimir; Stumpf, Max C.; Schori, Christian; Di Domenico, Gianni; Keller, Ursula; Schilt, Stéphane; Südmeyer, Thomas

    2012-01-01

    We investigate the dynamics of the carrier-envelope-offset (CEO) frequency, ƒ CEO, controlled by a pump current on the self-referencing of an optical frequency comb generated from a diode-pumped solid-state laser at 1.56 μm. We observe a reversal point in the tuning of ƒ CEO with the pump current. Between the low- and high-frequency region in the dynamic response of ƒ CEO to pump current modulation, we observe a significant phase shift of ≈180  deg in the transfer function. As a result, it is...

  5. Low Background Micromegas in CAST

    Science.gov (United States)

    Garza, J. G.; Aune, S.; Aznar, F.; Calvet, D.; Castel, J. F.; Christensen, F. E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J. A.; Giomataris, I.; Hill, R. M.; Iguaz, F. J.; Irastorza, I. G.; Jakobsen, A. C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M. J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J. K.

    2015-11-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10-6 counts/keV/cm2/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10-7 counts/keV/cm2/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as the strategies to further reduce the background level. Finally, we will describe the R&D paths to achieve sub-keV energy thresholds, which could broaden the physics case of axion helioscopes.

  6. Maximum-Likelihood Estimator of Clock Offset between Nanomachines in Bionanosensor Networks

    Science.gov (United States)

    Lin, Lin; Yang, Chengfeng; Ma, Maode

    2015-01-01

    Recent advances in nanotechnology, electronic technology and biology have enabled the development of bio-inspired nanoscale sensors. The cooperation among the bionanosensors in a network is envisioned to perform complex tasks. Clock synchronization is essential to establish diffusion-based distributed cooperation in the bionanosensor networks. This paper proposes a maximum-likelihood estimator of the clock offset for the clock synchronization among molecular bionanosensors. The unique properties of diffusion-based molecular communication are described. Based on the inverse Gaussian distribution of the molecular propagation delay, a two-way message exchange mechanism for clock synchronization is proposed. The maximum-likelihood estimator of the clock offset is derived. The convergence and the bias of the estimator are analyzed. The simulation results show that the proposed estimator is effective for the offset compensation required for clock synchronization. This work paves the way for the cooperation of nanomachines in diffusion-based bionanosensor networks. PMID:26690173

  7. Evidence for a systematic offset of $-$0.25~mas in the Gaia DR1 parallaxes

    CERN Document Server

    Stassun, Keivan G

    2016-01-01

    We test the parallaxes reported in the Gaia first data release using the sample of eclipsing binaries with accurate, empirical distances from Stassun & Torres (2016). We find a clear average offset of $-$0.25$\\pm$0.05 mas in the sense of the Gaia parallaxes being too small (i.e., the distances too long). The documented Gaia systematic uncertainty is 0.3 mas, which the eclipsing binary sample corroborates. The offset does not depend strongly on obvious parameters such as color, brightness, or spatial position. However, with a statistical significance of 99.7%, nearer stars possibly exhibit larger offsets according to $\\Delta\\pi \\approx -0.16 -0.02 \\times \\pi$ mas.

  8. Tuning SISO offset-free Model Predictive Control based on ARX models

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted; Poulsen, Niels Kjølstad; Jørgensen, Sten Bay;

    2012-01-01

    -free control in face of unknown disturbances or model-plant mismatch, integrators must be introduced in either the estimator or the regulator. Traditionally, offset-free control is achieved using Brownian disturbance models in the estimator. In this paper we achieve offset-free control by extending the noise......In this paper, we present a tuning methodology for a simple offset-free SISO Model Predictive Controller (MPC) based on autoregressive models with exogenous inputs (ARX models). ARX models simplify system identification as they can be identified from data using convex optimization. Furthermore...... model with a filter containing an integrator. This filter is a first order ARMA model. By simulation and analysis, we argue that it is independent of the parameterization of the underlying linear plant; while the tuning of traditional disturbance models is system dependent. Using this insight, we...

  9. Implementation of an offset-dipole magnetic field in a pulsar modelling code

    CERN Document Server

    Breed, M; Harding, A K; Johnson, T J

    2014-01-01

    The light curves of gamma-ray pulsars detected by the Fermi Large Area Telescope show great variety in profile shape and position relative to their radio profiles. Such diversity hints at distinct underlying magnetospheric and/or emission geometries for the individual pulsars. We implemented an offset-dipole magnetic field in an existing geometric pulsar modelling code which already includes static and retarded vacuum dipole fields. In our model, this offset is characterised by a parameter epsilon (with epsilon = 0 corresponding to the static dipole case). We constructed sky maps and light curves for several pulsar parameters and magnetic fields, studying the effect of an offset dipole on the resulting light curves. A standard two-pole caustic emission geometry was used. As an application, we compared our model light curves with Fermi data for the bright Vela pulsar.

  10. Application of offset dual-shaped reflectors to large ground antennas

    Science.gov (United States)

    Galindo-Israel, V.; Veruttipong, W.; Imbriale, W. A.; Norrod, R.

    1991-06-01

    Several characteristics of dual offset shaped reflector (DOSR) antennas are examined. Despite the potentially superior performance of DOSR over conventional Cassegrain/Gregorian offset designs and over shaped circular symmetric designs, these characteristics can make the DOSR designs less desirable. In particular, the simultaneous multiple-beam capability of DOSR is found to be inferior to conic (paraboloid-ellipse/hyperboloid) reflectors. This difficulty can possibly be overcome to some degree by the use of overlapping feed arrays. The higher manufacturing cost of a DOSR can be somewhat ameliorated by the use of adjustable panels on a large offset paraboloid if the paraboloid and a shaped reflector are very little different in shape. The adjustable panels may be used for correction of gravity and wind distortions as well as for shaping. It is pointed out that new exact synthesis methods for DOSR permit the design of very low cross-polarization aperture distributions such as are obtainable with Mizugutch designs for conic systems.

  11. Joint timing synchronization and frequency offset acquisition algorithm for MIMO OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Liu Qi; Hu Bo

    2009-01-01

    For multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) sys-tems, a joint timing synchronization and frequency offset acquisition algorithm based on fractional Fourier transform (FRFT) is proposed. The linear frequency modulation signals superimposed on the data signals are used as the training signals. By performing FRFT on the receiver signals and searching the peak value of the FRFT results, the receiver can realize timing synchronization and frequency offset acquisition simultaneously. Compared with the existing methods, the proposed algorithm can provide better timing synchronization performance and larger frequency offset acquisition range even under multi-path channels with low signal to noise ratio. Theoretical analysis and simulation results prove this point.

  12. Improving OFDM/DQPSK System Performance in the Conditions of Frequency Offset Existence

    Directory of Open Access Journals (Sweden)

    B. R. Dimitrijević

    2010-11-01

    Full Text Available The basic characteristics of Orthogonal Frequency Division Multiplex (OFDM systems with DQPSK modulation and channel estimation with an adaptive transversal filter and LMS algorithm are analyzed and presented in this paper. In the simulation environment designed for this purpose, we analyzed the effects of frequency offset on the performance of OFDM digital communications and presented the method for improving system performance in the presence of frequency offset. We analyzed the influence of OFDM system parameters on system’s performance for various values of frequency offsets, filter lengths and the number of subcarriers. Finally, we compared the result with the one for a perfectly synchronized OFDM/DQPSK system with differential and coherent demodulation.

  13. Modelling electroluminescence in insulating polymers under ac stress: effect of voltage offset and pre-stressing

    International Nuclear Information System (INIS)

    Ac electroluminescence (EL) in polyethylene films is well documented on experimental grounds but a detailed model encompassing injection and transport is still to be strengthened. In particular, different papers report that the EL under ac sinusoidal voltage for both divergent and uniform field configurations is independent of a superimposed dc voltage offset, which is confirmed by our own measurements. Based on modelling, we show that the dc offset voltage induces a transient behaviour of the ac EL; where the symmetry between the EL peaks occurring during each half cycle of the ac voltage is broken but the same steady state is reached for any value of dc offset. The transient duration is short relative to the timescale of a typical EL measurement explaining why it has not been reported experimentally. It depends on the injection level, charge mobility and recombination efficiency. The model also explains the dependence of ac EL on the presence of homo-space charge near the electrodes. (paper)

  14. Programmable Gain Amplifiers with DC Suppression and Low Output Offset for Bioelectric Sensors

    Directory of Open Access Journals (Sweden)

    Alonso Alonso

    2013-09-01

    Full Text Available DC-offset and DC-suppression are key parameters in bioelectric amplifiers. However, specific DC analyses are not often explained. Several factors influence the DC-budget: the programmable gain, the programmable cut-off frequencies for high pass filtering and, the low cut-off values and the capacitor blocking issues involved. A new intermediate stage is proposed to address the DC problem entirely. Two implementations were tested. The stage is composed of a programmable gain amplifier (PGA with DC-rejection and low output offset. Cut-off frequencies are selectable and values from 0.016 to 31.83 Hz were tested, and the capacitor deblocking is embedded in the design. Hence, this PGA delivers most of the required gain with constant low output offset, notwithstanding the gain or cut-off frequency selected.

  15. Axial offset as measure of stability of light water nuclear reactor during capacity maneuvering

    Directory of Open Access Journals (Sweden)

    Mark V. Nikolsky

    2015-03-01

    Full Text Available High reliability and security of power unit are required during operation of power unit while maneuvering. They depend on the stability of reactor when transition from one power level to another. The axial offset is a quantitative measure of the reactor stability. It is shown that change of the active core inlet coolant temperature yields an uncontrollable disturbance affecting the axial offset and therefore the reactor stability. To insure the reactor stability the compromise-combined power control method is proposed. Analysis of the influence of temperature of coolant at the magnitude of the axial offset for different regulatory programs is carried out. The change in the depth of immersion of regulators in the active zone for different regulatory programs when the reactor plant daily capacity maneuver is studied.

  16. A definition of background independence

    International Nuclear Information System (INIS)

    We propose a definition for background (in)/dependence in dynamical theories of the evolution of configurations that have a continuous symmetry and test this definition on particle models and on gravity. Our definition draws from Barbour's best matching framework developed for the purpose of implementing spatial and temporal relationalism. Among other interesting theories, general relativity can be derived within this framework in novel ways. We study the detailed canonical structure of a wide range of best matching theories and show that their actions must have a local gauge symmetry. When gauge theory is derived in this way, we obtain at the same time a conceptual framework for distinguishing between background-dependent and -independent theories. Gauge invariant observables satisfying Kuchar's criterion are identified and, in simple cases, explicitly computed. We propose a procedure for inserting a global background time into temporally relational theories. Interestingly, using this procedure in general relativity leads to unimodular gravity.

  17. Neutron background estimates in GESA

    Directory of Open Access Journals (Sweden)

    Fernandes A.C.

    2014-01-01

    Full Text Available The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against (μ,n neutrons to below 10−8 cm−2 s−1, it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10−3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container.

  18. A novel calibration method for phase-locked loops

    DEFF Research Database (Denmark)

    Cassia, Marco; Shah, Peter Jivan; Bruun, Erik

    2005-01-01

    A novel method to calibrate the frequency response of a Phase-Locked Loop is presented. The method requires just an additional digital counter to measure the natural frequency of the PLL; moreover it is capable of estimating the static phase offset. The measured value can be used to tune the PLL ...

  19. Detector Background at Muon Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2011-09-01

    Physics goals of a Muon Collider (MC) can only be reached with appropriate design of the ring, interaction region (IR), high-field superconducting magnets, machine-detector interface (MDI) and detector. Results of the most recent realistic simulation studies are presented for a 1.5-TeV MC. It is shown that appropriately designed IR and MDI with sophisticated shielding in the detector have a potential to substantially suppress the background rates in the MC detector. The main characteristics of backgrounds are studied.

  20. Children of ethnic minority backgrounds

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    2010-01-01

    media products and toys just as they will have knowledge of different media texts, play genres, rhymes etc. This has consequences for their ability to access social settings, for instance in play. New research in this field will focus on how children themselves make sense of this balancing of cultures......Children of ethnic minority background balance their everyday life between a cultural background rooted in their ethnic origin and a daily life in day care, schools and with peers that is founded in a majority culture. This means, among other things, that they often will have access to different...

  1. Background music and cognitive performance.

    Science.gov (United States)

    Angel, Leslie A; Polzella, Donald J; Elvers, Greg C

    2010-06-01

    The present experiment employed standardized test batteries to assess the effects of fast-tempo music on cognitive performance among 56 male and female university students. A linguistic processing task and a spatial processing task were selected from the Criterion Task Set developed to assess verbal and nonverbal performance. Ten excerpts from Mozart's music matched for tempo were selected. Background music increased the speed of spatial processing and the accuracy of linguistic processing. The findings suggest that background music can have predictable effects on cognitive performance. PMID:20865993

  2. Generative electronic background music system

    International Nuclear Information System (INIS)

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions

  3. Generative electronic background music system

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, Lukasz [Faculty of Computer Science, West Pomeranian University of Technology in Szczecin, Zolnierska Street 49, Szczecin, PL (Poland)

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  4. Exotic branes and nongeometric backgrounds.

    Science.gov (United States)

    de Boer, Jan; Shigemori, Masaki

    2010-06-25

    When string or M theory is compactified to lower dimensions, the U-duality symmetry predicts so-called exotic branes whose higher-dimensional origin cannot be explained by the standard string or M-theory branes. We argue that exotic branes can be understood in higher dimensions as nongeometric backgrounds or U folds, and that they are important for the physics of systems which originally contain no exotic charges, since the supertube effect generically produces such exotic charges. We discuss the implications of exotic backgrounds for black hole microstate (non-)geometries. PMID:20867363

  5. The Purchase of Voluntary Carbon Offsets by Australian Consumers: Exploring the Attitude-Behaviour Gap

    DEFF Research Database (Denmark)

    Adamsen, Jannie Mia; Sloan, Sarah

    2011-01-01

    This research examines the level of environmental awareness among Australian consumers and identifies the factors that affect attitudes and behaviour towards purchasing carbon offset products. Data was obtained from 83 consumers through an online survey to measure knowledge and purchase behaviour...... of carbon offsets, intention for future purchases and attitudes towards the environment. The results demonstrate that an attitude-behaviour gap exists among Australian consumers; while consumers possess strong positive attitudes towards the environment and climate change, this does not translate into actual...

  6. Temperature dependent band offsets in PbSe/PbEuSe quantum well heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Simma, M.; Bauer, G.; Springholz, G. [Institut fuer Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet, A-4040 Linz (Austria)

    2012-10-22

    The band offsets of PbSe/Pb{sub 1-x}Eu{sub x}Se multi-quantum wells grown by molecular beam epitaxy are determined as a function of temperature and europium content using temperature-modulated differential transmission spectroscopy. The confined quantum well states in the valence and conduction bands are analyzed using a k{center_dot}p model with envelope function approximation. From the fit of the experimental data, the normalized conduction band offset is determined as 0.45{+-}0.15 of the band gap difference, independently of Eu content up to 14% and temperature from 20 to 300 K.

  7. SOA-based OTDM-DPSK Demultiplexing Assisted by Offset-Filtering

    DEFF Research Database (Denmark)

    Xu, Jing; Ding, Yunhong; Peucheret, Christophe;

    2011-01-01

    We demonstrated for the first time 80 to 40 Gb/s OTDM-DPSK demultiplexing using a single SOA assisted by offset-filtering. Error free performance is achieved with an average power penalty of 5.5 dB.......We demonstrated for the first time 80 to 40 Gb/s OTDM-DPSK demultiplexing using a single SOA assisted by offset-filtering. Error free performance is achieved with an average power penalty of 5.5 dB....

  8. Strike slip faulting inferred from offsetting of drainages: Lower Narmada basin, western India

    Indian Academy of Sciences (India)

    Rachna Raj

    2007-10-01

    The detailed analysis of landforms,drainages and geology of the area between the rivers Amaravati and Karjan was carried out in order to understand the tectonic history of the lower Narmada basin. Movement along the various faults in the area was studied on the basis of the drainage offsetting. Horizontal offsetting of stream channels was found quite demonstrable along NNW –SSE trending transverse faults.Tectonic landforms including systematic de flection of stream channels and ridges, alignment of fault scarp and saddles and displacement in the basement rocks and alluvial deposits show that the area is undergoing active deformation driven by the NSF system.

  9. Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

    CERN Document Server

    Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

    2011-01-01

    We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

  10. Additional evidence concerning the valence-band offset in HgTe/CdTe

    Science.gov (United States)

    Young, P. M.; Ehrenreich, H.

    1991-05-01

    The consistency of large values of the valence-band offset, Λ, in HgTe/CdTe superlattices with magneto-optical experiments is examined in light of data on a 90-Å HgTe/40-Å CdTe superlattice. The data are shown to be consistent with values Λ=400+/-40 meV rather than the much smaller cited values. This analysis, when considered with photoemission experiments, leaves intact the conclusion that HgTe/CdTe superlattices are best explained by a large offset.

  11. Sectoral Offsets in the Mexican Oil and Gas Industry: Developing a Credible Baseline via Econometric Methods

    OpenAIRE

    Morgenstern, Richard; Egorenkov, Alexander; Velez-Lopez, Daniel

    2015-01-01

    Sectoral greenhouse gas offsets can provide the same incentives for emissions reductions as a carbon tax or a cap-and-trade program, with a focus on rewards rather than costs. This paper develops a pilot analysis of such offsets using relatively transparent quantitative methods to estimate a business-asusual (BAU) emissions path for the gas and basic petrochemical subsidiary of Mexico’s national oil company, Pemex. This BAU path, in turn, may be used as a basis for monetizing emissions reduct...

  12. Efficient Calculation of Born Scattering for Fixed-Offset Ground-Penetrating Radar Surveys

    DEFF Research Database (Denmark)

    Meincke, Peter

    2007-01-01

    A formulation is presented for efficient calculation of linear electromagnetic scattering by buried penetrable objects, as involved in the analysis of fixed-offset ground-penetrating radar (GPR) systems. The actual radiation patterns of the GPR antennas are incorporated in the scattering calculat......A formulation is presented for efficient calculation of linear electromagnetic scattering by buried penetrable objects, as involved in the analysis of fixed-offset ground-penetrating radar (GPR) systems. The actual radiation patterns of the GPR antennas are incorporated in the scattering...

  13. Point Climat no. 11 'Japan's Bilateral Offset Crediting Mechanism: A Bilateral Solution to a Global Issue?'

    International Nuclear Information System (INIS)

    Among the publications of CDC Climat Research, 'Climate Briefs' presents, in a few pages, hot topics in climate change policy. This issue addresses the following points: In order to achieve its long-term emission reduction target following the Fukushima incident, Japan would rely more heavily on international offsetting activities. Concurrent to vigorous proposals to reform the CDM, Japan is also promoting an offset crediting scheme through bilateral agreements with developing countries as a post-2012 market mechanism. Despite potential benefits, issues relating to the accounting rules, environmental integrity and implications to carbon markets warrant further consideration prior to international recognition

  14. Application of the Common Offset Seismic Reflection Method to Urban Active Fault Surveys

    Institute of Scientific and Technical Information of China (English)

    Liu Baojin; Ji Jifa; Xu Zhaofan; Yuan Hongke; Liao Xu; Bai Yun; Wan Bo

    2007-01-01

    The method and principle of common offset seismic surveys as well as the field data gathering and processing technique were introduced briefly. Through two urban active fault survey examples in Fuzhou and Shenyang, the efficiency and limitation of using the common offset seismic reflection technique to carry out urban active fault surveys were probed. The results show that this technique has the properties of high resolving power, better reconstruction of subsurface structures, and real-time analyzing and interpretation of investigation results on site. This method can be used to quickly locate objects under investigation accurately in the areas with thinner Quaternary overburdens and strong bedrock interface fluctuations.

  15. A novel phase noise measurement of phase modulation microwave photonic links

    Science.gov (United States)

    Ye, Quanyi; Gao, Yingjie; Yang, Chun

    2016-07-01

    Microwave photonic links can provide many advantages over traditional coaxial due to its low loss, small size, lightweight, large bandwidth and immunity to external interference. In this paper, a novel phase noise measurement system is built, since the input signal and the power supply noise can be effectively cancelled by a two-arm configuration without the phase locking. Using this approach, the phase noise performance of the 10-GHz phase modulation photonic link has been measured for the first time, evaluated the values of -124 dBc/Hz at 1 kHz offset and -132 dBc/Hz at 10 kHz offset is obtained. Theoretical analysis on the phase noise measurement system calibration is also discussed.

  16. No net loss of biodiversity or paper offsets? A critical review of the French no net loss policy

    OpenAIRE

    Quetier, Fabien; Regnery, Baptiste; Levrel, Harold

    2014-01-01

    French regulations concerning the mitigation of development impacts have been progressively strengthened with offsets now required for impacts on forests, wetlands, and protected species, among others. In 2012, following a national consultative process called Grenelle de l’Environnement, legal requirements in terms of monitoring and effective implementation of measures aimed at avoiding, reducing and offsetting impacts were strengthened. This has created strong “demand” for offsets. The w...

  17. Genetic vulnerability to diabetes and obesity: does education offset the risk?

    Science.gov (United States)

    Liu, S Y; Walter, S; Marden, J; Rehkopf, D H; Kubzansky, L D; Nguyen, T; Glymour, M M

    2015-02-01

    The prevalence of type 2 diabetes (T2D) and obesity has recently increased dramatically. These common diseases are likely to arise from the interaction of multiple genetic, socio-demographic and environmental risk factors. While previous research has found genetic risk and education to be strong predictors of these diseases, few studies to date have examined their joint effects. This study investigates whether education modifies the association between genetic background and risk for type 2 diabetes (T2D) and obesity. Using data from non-Hispanic Whites in the Health and Retirement Study (HRS, n = 8398), we tested whether education modifies genetic risk for obesity and T2D, offsetting genetic effects; whether this effect is larger for individuals who have high risk for other (unobserved) reasons, i.e., at higher quantiles of HbA1c and BMI; and whether effects differ by gender. We measured T2D risk using Hemoglobin A1c (HbA1c) level, and obesity risk using body-mass index (BMI). We constructed separate genetic risk scores (GRS) for obesity and diabetes respectively based on the most current available information on the single nucleotide polymorphism (SNPs) confirmed as genome-wide significant predictors for BMI (29 SNPs) and diabetes risk (39 SNPs). Linear regression models with years of schooling indicate that the effect of genetic risk on HbA1c is smaller among people with more years of schooling and larger among those with less than a high school (HS) degree compared to HS degree-holders. Quantile regression models show that the GRS × education effect systematically increased along the HbA1c outcome distribution; for example the GRS × years of education interaction coefficient was -0.01 (95% CI = -0.03, 0.00) at the 10th percentile compared to -0.03 (95% CI = -0.07, 0.00) at the 90th percentile. These results suggest that education may be an important socioeconomic source of heterogeneity in responses to genetic vulnerability to T2D.

  18. Educational Choice. A Background Paper.

    Science.gov (United States)

    Quality Education for Minorities Network, Washington, DC.

    This paper addresses school choice, one proposal to address parental involvement concerns, focusing on historical background, definitions, rationale for advocating choice, implementation strategies, and implications for minorities and low-income families. In the past, transfer payment programs such as tuition tax credits and vouchers were…

  19. Low Background Micromegas in CAST

    DEFF Research Database (Denmark)

    Garza, J G; Aune, S.; Aznar, F.;

    2014-01-01

    to background levels below 10−6 counts/keV/cm2/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10−7 counts/keV/cm2/s, showing good prospects for the application of this technology in IAXO...

  20. Low Background Micromegas in CAST

    CERN Document Server

    Garza, J G; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

    2015-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

  1. Willingness to pay for carbon offset certification and co-benefits among (high-)flying young adults in the UK

    Energy Technology Data Exchange (ETDEWEB)

    MacKerron, George J.; Mourato, Susana [Department of Geography and Environment, and Grantham Research Institute on Climate Change and the Environment, London School of Economics and Political Science, Houghton Street, London WC2A 2AE (United Kingdom); Egerton, Catrin [Centre for Environmental and Sustainability Research, Ecological Economics and Environmental Management Group, New University of Lisbon, Quinta da Torre, 2829-516 Caparica (Portugal); Gaskell, Christopher [106 Bryer Court, Barbican, London EC2Y 8DE (United Kingdom); Parpia, Aimie [New Carbon Finance, New Penderel House, 283-288 High Holborn, London WC1V 7HP (United Kingdom)

    2009-04-15

    Voluntary carbon offsets represent a growing share of the carbon market as a whole, and have the potential to contribute to meeting greenhouse gas emissions targets and reducing anthropogenic climate change. Certain offset project types may also deliver co-benefits including safeguarding or promoting biodiversity, supporting human development and poverty reduction, and enabling market and technology development in low-carbon sectors. These co-benefits might encourage consumers to participate in the voluntary offset market, depending on their effects both on consumers' willingness to pay (WTP) for offsets and on implementation costs. However, the offset market is not yet sufficiently developed to give a clear indication of consumer WTP for offsets with varying attributes. This exploratory stated preference study therefore uses a choice experiment to estimate WTP for certified and uncertified offsets, with or without these specific co-benefits, in an aviation context. It is, to the best of our knowledge, the first to do so. Our results suggest that uptake of voluntary offsets may be encouraged by investing in projects with co-benefits and by emphasising those co-benefits to consumers. They also suggest that certification regimes will add value to offsets, helping compensate for increased costs, provided that consumers are made fully aware of them. (author)

  2. Willingness to pay for carbon offset certification and co-benefits among (high-)flying young adults in the UK

    International Nuclear Information System (INIS)

    Voluntary carbon offsets represent a growing share of the carbon market as a whole, and have the potential to contribute to meeting greenhouse gas emissions targets and reducing anthropogenic climate change. Certain offset project types may also deliver co-benefits including safeguarding or promoting biodiversity, supporting human development and poverty reduction, and enabling market and technology development in low-carbon sectors. These co-benefits might encourage consumers to participate in the voluntary offset market, depending on their effects both on consumers' willingness to pay (WTP) for offsets and on implementation costs. However, the offset market is not yet sufficiently developed to give a clear indication of consumer WTP for offsets with varying attributes. This exploratory stated preference study therefore uses a choice experiment to estimate WTP for certified and uncertified offsets, with or without these specific co-benefits, in an aviation context. It is, to the best of our knowledge, the first to do so. Our results suggest that uptake of voluntary offsets may be encouraged by investing in projects with co-benefits and by emphasising those co-benefits to consumers. They also suggest that certification regimes will add value to offsets, helping compensate for increased costs, provided that consumers are made fully aware of them

  3. Willingness to pay for carbon offset certification and co-benefits among (high-)flying young adults in the UK

    International Nuclear Information System (INIS)

    Voluntary carbon offsets represent a growing share of the carbon market as a whole, and have the potential to contribute to meeting greenhouse gas emissions targets and reducing anthropogenic climate change. Certain offset project types may also deliver co-benefits including safeguarding or promoting biodiversity, supporting human development and poverty reduction, and enabling market and technology development in low-carbon sectors. These co-benefits might encourage consumers to participate in the voluntary offset market, depending on their effects both on consumers' willingness to pay (WTP) for offsets and on implementation costs. However, the offset market is not yet sufficiently developed to give a clear indication of consumer WTP for offsets with varying attributes. This exploratory stated preference study therefore uses a choice experiment to estimate WTP for certified and uncertified offsets, with or without these specific co-benefits, in an aviation context. It is, to the best of our knowledge, the first to do so. Our results suggest that uptake of voluntary offsets may be encouraged by investing in projects with co-benefits and by emphasising those co-benefits to consumers. They also suggest that certification regimes will add value to offsets, helping compensate for increased costs, provided that consumers are made fully aware of them. (author)

  4. The Calaveras Fault, Northern California: A Geophysical Perspective on Offset and 3-D Geometry

    Science.gov (United States)

    Jachens, R. C.; Wentworth, C. M.; Graymer, R. W.; Walker, J. P.; Chuang, F. C.; Simpson, R. W.; McLaughlin, R. J.

    2002-12-01

    Gravity and magnetic investigations of the Calaveras Fault (CF) present an image of a San Andreas system strike-slip fault that is highly variable along strike, both in offset accommodation and geometry. Geologic correlation of rocks of the Permanente terrane (Franciscan Complex) west of the CF near Gilroy (km 120) with similar rocks east of the San Andreas Fault near Parkfield indicate 165-190 km of San Andreas Fault system total offset at the south end of the CF (McLaughlin et al., 1996) (note: all distances are measured along the CF from Carquinez Strait). Characteristic gravity and magnetic anomalies refine this offset to 174 km. Farther north (km 100), the CF active trace appears to offset the extreme south end of the linear Evergreen gravity low (which reflects a deep basin) no more than 3-5 km. In San Felipe valley (km 90), gravity reveals a shallow 2-km-long extensional basin along the active trace (implying a minimum offset), where a narrow belt of Miocene sedimentary units cut by the CF also appears to be offset at most only a few km. An alternative interpretation exists with much larger offset on a subparallel strand (Graymer et al., 2002). Near Calaveras Reservoir (km 60), magnetic anomalies imply that a wide sheet of inferred Coast Range Ophiolite extends at depth from at least 20 km NE of the CF to at least 1 km SW of the trace. The ophiolite is not obviously offset by the CF, which could be explained by small total offset, a shallowly west-dipping CF, or other unrecognized strands to the west. Near Dublin (km 30) the trace of the CF crosses a linear magnetic anomaly without apparently offsetting it. This anomaly is caused by folded magnetic strata of the Neroly Formation (formation age 10-7 Ma, fold age CF (km 10) near Pleasant Hill, a shallow basin about 10 km long is properly located to be an extensional basin caused by a right-step from the CF to the Concord Fault. If correctly interpreted, this basin could indicate at least 10 km of offset. The 3

  5. Application of offset-CT scanning to the inspection of high power feeder lines and connections

    Science.gov (United States)

    Schneberk, Daniel; Maziuk, Robert; Soyfer, Boris; Shashishekhar, N.; Alreja, Rahul

    2016-02-01

    VJT is developing techniques and scanning methods for the in-situ Radiographic and Computed Tomographic inspection of underground high-power feeder cables. The goals for the inspection are to measure the 3D state of the cables and the cable-connections. Recent in-situ Digital Radiographic inspections performed by VJT have demonstrated the value of NDE inspection information for buried power lines. These NDE data have raised further questions as to the exact state of the cables and connections and pointed to the need for more 3D information of the type provided by volumetric CT scanning. VJT is pursuing a three phased approach to address the many issues involved in this type of inspection: 1) develop a high-power feeder-cable test-bed CT scanner, 2) acquire scans on underground feeder pipes that have been removed from service, and 3) from the work in 1) and 2) develop limited-angle CT scanning methods for extending in-situ Digital Radiography to volumetric CT measurements. To this end, VJT has developed and fielded a high-energy test-bed Gantry-type CT scanner (the source and detector move around the object) with a number of important properties. First, the geometry of the gantry-scans can be configured to match the techniques used in the in-situ radiographic inspection. The same X-ray source is employed as in portable Radiographic inspections, a 7.5 MeV Betatron coupled to a Perkin-Elmer Amorphous Silicon detector. Offset-CT scanning is employed as the high-power feeder line assembly is larger than the detector. A description of this scanner and the scan geometry will be presented showing the connection to in-situ radiography. Results from the CT scans of high-power feeder-cable specimens removed from service will be presented with a focus on the inspection potential of volumetric CT data on these assemblies. An evaluation of the scan performance properties of these data compared to the spectrum of life-cycle inspection issues will be presented. Continuing and

  6. Offset Manchester coding for Rayleigh noise suppression in carrier-distributed WDM-PONs

    Science.gov (United States)

    Xu, Jing; Yu, Xiangyu; Lu, Weichao; Qu, Fengzhong; Deng, Ning

    2015-07-01

    We propose a novel offset Manchester coding in upstream to simultaneously realize Rayleigh noise suppression and differential detection in a carrier-distributed wavelength division multiplexed passive optical network. Error-free transmission of 2.5-Gb/s upstream signals over 50-km standard single mode fiber is experimentally demonstrated, with a 7-dB enhanced tolerance to Rayleigh noise.

  7. Attribution of precipitation changes on ground-air temperature offset: Granger causality analysis

    Science.gov (United States)

    Cermak, Vladimir; Bodri, Louise

    2016-06-01

    This work examines the causal relationship between the value of the ground-air temperature offset and the precipitation changes for monitored 5-min data series together with their hourly and daily averages obtained at the Sporilov Geophysical Observatory (Prague). Shallow subsurface soil temperatures were monitored under four different land cover types (bare soil, sand, short-cut grass and asphalt). The ground surface temperature (GST) and surface air temperature (SAT) offset, ΔT(GST-SAT), is defined as the difference between the temperature measured at the depth of 2 cm below the surface and the air temperature measured at 5 cm above the surface. The results of the Granger causality test did not reveal any evidence of Granger causality for precipitation to ground-air temperature offsets on the daily scale of aggregation except for the asphalt pavement. On the contrary, a strong evidence of Granger causality for precipitation to the ground-air temperature offsets was found on the hourly scale of aggregation for all land cover types except for the sand surface cover. All results are sensitive to the lag choice of the autoregressive model. On the whole, obtained results contain valuable information on the delay time of ΔT(GST-SAT) caused by the rainfall events and confirmed the importance of using autoregressive models to understand the ground-air temperature relationship.

  8. Development of karanja oil based offset printing ink in comparison with linseed oil.

    Science.gov (United States)

    Bhattacharjee, Moumita; Roy, Ananda Sankar; Ghosh, Santinath; Dey, Munmun

    2011-01-01

    The conventional offset lithographic printing ink is mainly based on linseed oil. But in recent years, due to stiff competition from synthetic substitutes mainly from petroleum products, the crop production shrinks down to an unsustainable level, which increases the price of linseed oil. Though soyabean oil has replaced a major portion of linseed oil, it is also necessary to develop alternate cost effective vegetable oils for printing ink industry. The present study aims to evaluate the performance of karanja oil (Pongamia glabra) as an alternative of linseed oil in the formulation of offset printing ink because karanja oil is easily available in rural India. Physical properties of raw karanja oil are measured and compared with that of alkali refined linseed oil. Rosin modified phenolic resin based varnishes were made with linseed oil as well as with karanja oil and their properties are compared. Sheetfed offset inks of process colour yellow and cyan is chosen to evaluate the effect of karanja oil in ink properties. In conclusion, karanja oil can be accepted as an alternate vegetable oil source with its noticeable effect on print and post print properties with slower drying time on paper. However, the colour and odour of the oil will restrict its usage on offset inks.

  9. 49 CFR 526.5 - Earning offsetting monetary credits in future model years.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Earning offsetting monetary credits in future model years. 526.5 Section 526.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PETITIONS AND PLANS FOR RELIEF UNDER THE AUTOMOBILE FUEL EFFICIENCY...

  10. Stakeholders of Voluntary Forest Carbon Offset Projects in China: An Empirical Analysis

    Directory of Open Access Journals (Sweden)

    Derong Lin

    2015-01-01

    Full Text Available Climate change is one of the defining challenges facing the planet. Voluntary forest carbon offset project which has the potential to boost forest carbon storage and mitigate global warming has aroused the global concern. The objective of this paper is to model the game situation and analyze the game behaviors of stakeholders of voluntary forest carbon offset projects in China. A stakeholder model and a Power-Benefit Matrix are constructed to analyze the roles, behaviors, and conflicts of stakeholders including farmers, planting entities, communities, government, and China Green Carbon Foundation. The empirical analysis results show that although the stakeholders have diverse interests and different goals, a win-win solution is still possible through their joint participation and compromise in the voluntary forest carbon offset project. A wide governance structure laying emphasis on benefit balance, equality, and information exchanges and being regulated by all stakeholders has been constructed. It facilitates the agreement among the stakeholders with conflicting or different interests. The joint participation of stakeholders in voluntary forest carbon offset projects might change the government-dominated afforestation/reforestation into a market, where all participators including government are encouraged to cooperate with each other to improve the condition of fund shortage and low efficiency.

  11. 12 CFR 313.124 - Pre-offset notice and consideration of evidence.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Pre-offset notice and consideration of evidence... consideration of evidence. (a) For purposes of § 313.123(c)(2), the FDIC has made a reasonable effort to notify... or part of the debt is past-due and legally enforceable to request review by an officer or...

  12. 75 FR 32343 - Debt Collection and Administrative Offset for Monies Due the Federal Government

    Science.gov (United States)

    2010-06-08

    ..., Minerals Revenue Management, P.O. Box 25165, MS 61013B, Denver, Colorado 80225. Hand-carry comments or use... questions on procedural issues, contact Hyla Hurst, Regulatory Specialist, Minerals Revenue Management (MRM... Minerals Management Service 30 CFR Part 218 RIN 1010-AD36 Debt Collection and Administrative Offset...

  13. CMOS instrumentation amplifier with offset cancellation circuitry and high PSRR for low power application

    International Nuclear Information System (INIS)

    This paper presents the design and development of a CMOS instrumentation amplifier for biomedical application. The instrumentation amplifier possesses a very high power-supply rejection ratio (PSRR) and is able to operate at single supply voltage for low power application with improved performance compared to existing work. It also has a full CMOS implementation of offset cancellation circuitry. (author)

  14. Development of landsat-5 thematic mapper internal calibrator gain and offset table

    Science.gov (United States)

    Barsi, J.A.; Chander, G.; Micijevic, E.; Markham, B.L.; Haque, Md. O.

    2008-01-01

    The National Landsat Archive Production System (NLAPS) has been the primary processing system for Landsat data since U.S. Geological Survey (USGS) Earth Resources Observation and Science Center (EROS) started archiving Landsat data. NLAPS converts raw satellite data into radiometrically and geometrically calibrated products. NLAPS has historically used the Internal Calibrator (IC) to calibrate the reflective bands of the Landsat-5 Thematic Mapper (TM), even though the lamps in the IC were less stable than the TM detectors, as evidenced by vicarious calibration results. In 2003, a major effort was made to model the actual TM gain change and to update NLAPS to use this model rather than the unstable IC data for radiometric calibration. The model coefficients were revised in 2007 to reflect greater understanding of the changes in the TM responsivity. While the calibration updates are important to users with recently processed data, the processing system no longer calculates the original IC gain or offset. For specific applications, it is useful to have a record of the gain and offset actually applied to the older data. Thus, the NLAPS calibration database was used to generate estimated daily values for the radiometric gain and offset that might have been applied to TM data. This paper discusses the need for and generation of the NLAPSIC gain and offset tables. A companion paper covers the application of and errors associated with using these tables.

  15. Offset-sparsity decomposition for automated enhancement of color microscopic image of stained specimen in histopathology

    Science.gov (United States)

    Kopriva, Ivica; Hadžija, Marijana Popović; Hadžija, Mirko; Aralica, Gorana

    2015-07-01

    We propose an offset-sparsity decomposition method for the enhancement of a color microscopic image of a stained specimen. The method decomposes vectorized spectral images into offset terms and sparse terms. A sparse term represents an enhanced image, and an offset term represents a "shadow." The related optimization problem is solved by computational improvement of the accelerated proximal gradient method used initially to solve the related rank-sparsity decomposition problem. Removal of an image-adapted color offset yields an enhanced image with improved colorimetric differences among the histological structures. This is verified by a no-reference colorfulness measure estimated from 35 specimens of the human liver, 1 specimen of the mouse liver stained with hematoxylin and eosin, 6 specimens of the mouse liver stained with Sudan III, and 3 specimens of the human liver stained with the anti-CD34 monoclonal antibody. The colorimetric difference improves on average by 43.86% with a 99% confidence interval (CI) of [35.35%, 51.62%]. Furthermore, according to the mean opinion score, estimated on the basis of the evaluations of five pathologists, images enhanced by the proposed method exhibit an average quality improvement of 16.60% with a 99% CI of [10.46%, 22.73%].

  16. WASTE REDUCTION EVALUATION OF SOY-BASED INK AT A SHEET-FED OFFSET PRINTER

    Science.gov (United States)

    This Waste Reduction Innovative Technology Evaluation (WRITE) project quantifies and compares wastes generated from the use of soy-based and petroleum-based inks in sheet-fed offset printing. Data were collected in a full-scale print run on a Miller TP104 Plus 6-color press in Ju...

  17. 10 CFR 490.808 - Use of credits to offset petroleum reduction shortfall.

    Science.gov (United States)

    2010-01-01

    ... shortfall. DOE derives the credit amount using the fleet's fuel use per vehicle data. (c) DOE gives the.... 490.808 Section 490.808 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490.808 Use of credits to offset petroleum reduction...

  18. Fully integrated low-noise readout circuit with automatic offset cancellation loop for capacitive microsensors.

    Science.gov (United States)

    Song, Haryong; Park, Yunjong; Kim, Hyungseup; Cho, Dong-Il Dan; Ko, Hyoungho

    2015-10-14

    Capacitive sensing schemes are widely used for various microsensors; however, such microsensors suffer from severe parasitic capacitance problems. This paper presents a fully integrated low-noise readout circuit with automatic offset cancellation loop (AOCL) for capacitive microsensors. The output offsets of the capacitive sensing chain due to the parasitic capacitances and process variations are automatically removed using AOCL. The AOCL generates electrically equivalent offset capacitance and enables charge-domain fine calibration using a 10-bit R-2R digital-to-analog converter, charge-transfer switches, and a charge-storing capacitor. The AOCL cancels the unwanted offset by binary-search algorithm based on 10-bit successive approximation register (SAR) logic. The chip is implemented using 0.18 μm complementary metal-oxide-semiconductor (CMOS) process with an active area of 1.76 mm². The power consumption is 220 μW with 3.3 V supply. The input parasitic capacitances within the range of -250 fF to 250 fF can be cancelled out automatically, and the required calibration time is lower than 10 ms.

  19. Fully Integrated Low-Noise Readout Circuit with Automatic Offset Cancellation Loop for Capacitive Microsensors

    Directory of Open Access Journals (Sweden)

    Haryong Song

    2015-10-01

    Full Text Available Capacitive sensing schemes are widely used for various microsensors; however, such microsensors suffer from severe parasitic capacitance problems. This paper presents a fully integrated low-noise readout circuit with automatic offset cancellation loop (AOCL for capacitive microsensors. The output offsets of the capacitive sensing chain due to the parasitic capacitances and process variations are automatically removed using AOCL. The AOCL generates electrically equivalent offset capacitance and enables charge-domain fine calibration using a 10-bit R-2R digital-to-analog converter, charge-transfer switches, and a charge-storing capacitor. The AOCL cancels the unwanted offset by binary-search algorithm based on 10-bit successive approximation register (SAR logic. The chip is implemented using 0.18 μm complementary metal-oxide-semiconductor (CMOS process with an active area of 1.76 mm2. The power consumption is 220 μW with 3.3 V supply. The input parasitic capacitances within the range of −250 fF to 250 fF can be cancelled out automatically, and the required calibration time is lower than 10 ms.

  20. Gamma-Ray Pulsar Light Curves in Offset Polar Cap Geometry

    Science.gov (United States)

    Harding, Alice K.; DeCesar, Megan; Miller, M. Coleman

    2011-01-01

    Recent studies have shown that gamma-ray pulsar light curves are very sensitive to the geometry of the pulsar magnetic field. Pulsar magnetic field geometries, such as the retarded vacuum dipole and force-free magnetospheres, used to model high-energy light curves have distorted polar caps that are offset from the magnetic axis in the direction opposite to rotation. Since this effect is due to the sweepback of field lines near the light cylinder, offset polar caps are a generic property of pulsar magnetospheres and their effects should be included in gamma-ray pulsar light curve modeling. In slot gap models (having two-pole caustic geometry), the offset polar caps cause a strong azimuthal asymmetry of the particle acceleration around the magnetic axis. We have studied the effect of the offset polar caps in both retarded vacuum dipole and force-free geometry on the model high-energy pulse profile. We find that. corn pared to the profile:-; derived from :-;ymmetric caps, the flux in the pulse peaks, which are caustics formed along the trailing magnetic field lines. increases significantly relative to the off-peak emission. formed along leading field lines. The enhanced contrast produces greatly improved slot gap model fits to Fermi pulsar light curves like Vela, which show very little off-peak emIssIon.

  1. Hospitalization Cost Offset of a Hostility Intervention for Coronary Heart Disease Patients

    Science.gov (United States)

    Davidson, Karina W.; Gidron, Yori; Mostofsky, Elizabeth; Trudeau, Kimberlee J.

    2007-01-01

    The authors evaluated hospitalization cost offset of hostility management group therapy for patients with coronary heart disease (CHD) from a previously published randomized controlled trial (Y. Gidron, K. Davidson, & I. Bata, 1999). Twenty-six male patients with myocardial infarction or unstable angina were randomized to either 2 months of…

  2. 78 FR 32713 - Distribution of Continued Dumping and Subsidy Offset to Affected Domestic Producers

    Science.gov (United States)

    2013-05-31

    ... Offset to Affected Domestic Producers) in the Federal Register (66 FR 48546) on September 21, 2001, which... Co Inc. HG Wood Industries LLC. Hogan & Storey Wood Prod. Hogan Lumber Co. Hood Industries. HS Hofler.... Raymond & Melissa Pierie. Roper Growers Cooperative. Royal Brothers Groves. Seminole Tribe of Florida...

  3. Mechanical Properties of New Type Negative Offset Structure During Shearing Process of Heavy Steel Plate

    Institute of Scientific and Technical Information of China (English)

    MA Li-feng; HUANG Qing-xue; WANG Jian-mei; YANG Jian-wei; LI Ying; LI Jin-bao

    2007-01-01

    According to the revised Cailikefu's rolling shear force formula, motion path equation of spatial seven-bar path was built, and a mechanical model, with the new structural feature of negative offset, was thus successfully established for 2 800 mm heavy shear of some iron and steel company. Shear and bar forces of steel plate, before and after the adoption of negative offset structure, were analyzed, as well as horizontal force component of mechanism that influences pure rolling shear and back-wall push force that keeps blade clearance. It was found that the back-wall push force keeps large even at the time that the maximum rolling shear was obtained; meanwhile, back-wall push force is the most approximate to side forces when 60-100 mm of offset was adopted. Both theoretical results and on-site shear quality show that the negative offset plays an important role in ensuring the stability of pure rolling shear and keeping blade clearance constant.

  4. Beyond pure offsetting: Assessing options to generate Net-Mitigation-Effects in carbon market mechanisms

    NARCIS (Netherlands)

    Warnecke, C.; Wartmann, S.; Hoehne, N.E.; Blok, K.

    2014-01-01

    The current project-based carbon market mechanisms such as the Clean Development Mechanism (CDM) and the Joint Implementation (JI) do not have a direct impact on global greenhouse gas emission levels, because they only replace or offset emissions. Nor do they contribute to host country¿s national gr

  5. Beyond pure offsetting: Assessing options to generate Net-Mitigation-Effects in carbon market mechanisms

    NARCIS (Netherlands)

    Warnecke, C.; Wartmann, S.; Hohne, N.; Blok, Kornelis

    2014-01-01

    The current project-based carbon market mechanisms such as the Clean Development Mechanism (CDM) and the Joint Implementation (JI) do not have a direct impact on global greenhouse gas emission levels, because they only replace or offset emissions. Nor do they contribute to host country׳s national gr

  6. Derivation and application of the equivalent paraboloid for classical offset Cassegrain and Gregorian antennas

    Science.gov (United States)

    Rusch, Willard V. T.; Prata, Aluizio, Jr.; Rahmat-Samii, Yahya; Shore, Robert A.

    1990-08-01

    The equivalent paraboloid is derived for classical offset Cassegrain and Gregorian antennas. The important practical case of systems with circular exit apertures is discussed in detail, and a condition for a symmetric equivalent paraboloid is derived. For such systems, diffraction effects are investigated using tapered and scanned feeds to illuminate the equivalent paraboloid and the two-reflector system.

  7. Feedback and Stimulus-Offset Timing Effects in Perceptual Category Learning

    Science.gov (United States)

    Worthy, Darrell A.; Markman, Arthur B.; Maddox, W. Todd

    2013-01-01

    We examined how feedback delay and stimulus offset timing affected declarative, rule-based and procedural, information-integration category-learning. We predicted that small feedback delays of several hundred milliseconds would lead to the best information-integration learning based on a highly regarded neurobiological model of learning in the…

  8. Estimation of primaries and near-offset reconstruction by sparse inversion: Marine data applications

    NARCIS (Netherlands)

    Van Groenestijn, G.J.A.; Verschuur, D.J.

    2009-01-01

    ost wave-equation-based multiple removal algorithms are based on prediction and subtraction of multiples. Especially for shallow water, the prediction strongly relies on a correct interpolation of the missing near offsets. The subtraction of predicted multiples from the data can easily lead to the d

  9. How costly are carbon offsets? A meta-analysis of carbon forest sinks

    NARCIS (Netherlands)

    Kooten, van G.C.; Eagle, A.J.; Manley, J.; Smolak, T.

    2004-01-01

    Carbon terrestrial sinks are seen as a low-cost alternative to fuel switching and reduced fossil fuel use for lowering atmospheric CO2. As a result of agreements reached at Bonn and Marrakech, carbon offsets have taken on much greater importance in meeting Kyoto targets for the first commitment peri

  10. Crystal timing offset calibration method for time of flight PET scanners

    Science.gov (United States)

    Ye, Jinghan; Song, Xiyun

    2016-03-01

    In time-of-flight (TOF) positron emission tomography (PET), precise calibration of the timing offset of each crystal of a PET scanner is essential. Conventionally this calibration requires a specially designed tool just for this purpose. In this study a method that uses a planar source to measure the crystal timing offsets (CTO) is developed. The method uses list mode acquisitions of a planar source placed at multiple orientations inside the PET scanner field-of-view (FOV). The placement of the planar source in each acquisition is automatically figured out from the measured data, so that a fixture for exactly placing the source is not required. The expected coincidence time difference for each detected list mode event can be found from the planar source placement and the detector geometry. A deviation of the measured time difference from the expected one is due to CTO of the two crystals. The least squared solution of the CTO is found iteratively using the list mode events. The effectiveness of the crystal timing calibration method is evidenced using phantom images generated by placing back each list mode event into the image space with the timing offset applied to each event. The zigzagged outlines of the phantoms in the images become smooth after the crystal timing calibration is applied. In conclusion, a crystal timing calibration method is developed. The method uses multiple list mode acquisitions of a planar source to find the least squared solution of crystal timing offsets.

  11. 7 CFR 3.47 - Offset against amounts payable from Civil Service Retirement and Disability Fund.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Offset against amounts payable from Civil Service Retirement and Disability Fund. 3.47 Section 3.47 Agriculture Office of the Secretary of Agriculture DEBT... debtor's anticipated or future benefit payments under the Civil Service Retirement and Disability...

  12. Overview of Agricultural and Forestry GHG Offsets on the US Landscape

    OpenAIRE

    Murray, Brian C.

    2004-01-01

    US agriculture and forestry can help mitigate greenhouse gas emissions reaching up to 40% in a model analysis. Conservation tillage, forest management, afforestation, and bio-energy crop production are the most economic options, but their role depends on the value of offsets.

  13. Line-scan spatially offset Raman spectroscopy for inspecting subsurface food safety and quality

    Science.gov (United States)

    This paper presented a method for subsurface food inspection using a newly developed line-scan spatially offset Raman spectroscopy (SORS) technique. A 785 nm laser was used as a Raman excitation source. The line-shape SORS data was collected in a wavenumber range of 0–2815 cm-1 using a detection mod...

  14. Design of the Dual Offset Active Caster Wheel for Holonomic Omni-directional Mobile Robots

    Directory of Open Access Journals (Sweden)

    Woojin Chung

    2011-01-01

    Full Text Available It is shown how a holonomic and omni-directional mobile robot is designed towards indoor public services. Dual offset steerable wheels with orthogonal velocity components are proposed. The proposed wheel provides precise positioning and reliable navigation performance as well as durability. A fabricated prototype is introduced, then, an experiment is carried out.

  15. The Diffuse Supernova Neutrino Background

    CERN Document Server

    Beacom, John F

    2010-01-01

    The Diffuse Supernova Neutrino Background (DSNB) is the weak glow of MeV neutrinos and antineutrinos from distant core-collapse supernovae. The DSNB has not been detected yet, but the Super-Kamiokande (SK) 2003 upper limit on the electron antineutrino flux is close to predictions, now quite precise, based on astrophysical data. If SK is modified with dissolved gadolinium to reduce detector backgrounds and increase the energy range for analysis, then it should detect the DSNB at a rate of a few events per year, providing a new probe of supernova neutrino emission and the cosmic core-collapse rate. If the DSNB is not detected, then new physics will be required. Neutrino astronomy, while uniquely powerful, has proven extremely difficult -- only the Sun and the nearby Supernova 1987A have been detected to date -- so the promise of detecting new sources soon is exciting indeed.

  16. Stealths on Anisotropic Holographic Backgrounds

    CERN Document Server

    Ayón-Beato, Eloy; Juárez-Aubry, María Montserrat

    2015-01-01

    In this paper, we are interested in exploring the existence of stealth configurations on anisotropic backgrounds playing a prominent role in the non-relativistic version of the gauge/gravity correspondence. By stealth configuration, we mean a nontrivial scalar field nonminimally coupled to gravity whose energy-momentum tensor evaluated on the anisotropic background vanishes identically. In the case of a Lifshitz spacetime with a nontrivial dynamical exponent z, we spotlight the role played by the anisotropy to establish the holographic character of the stealth configurations, i.e. the scalar field is shown to only depend on the radial holographic direction. This configuration which turns out to be massless and without integration constants is possible for a unique value of the nonminimal coupling parameter. Then, using a simple conformal argument, we map this configuration into a stealth solution defined on the so-called hyperscaling violation metric which is conformally related to the Lifshitz spacetime. Thi...

  17. Background paper on aquaculture research

    OpenAIRE

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto; Torrissen, Ole

    2013-01-01

    The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including ...

  18. Stochastic background of gravitational waves

    CERN Document Server

    D'Araújo, J C N; Aguiar, O D

    2000-01-01

    A continuous stochastic background of gravitational waves (GWs) for burst sources is produced if the mean time interval between the occurrence of bursts is smaller than the average time duration of a single burst at the emission, i.e., the so called duty cycle must be greater than one. To evaluate the background of GWs produced by an ensemble of sources, during their formation, for example, one needs to know the average energy flux emitted during the formation of a single object and the formation rate of such objects as well. In many cases the energy flux emitted during an event of production of GWs is not known in detail, only characteristic values for the dimensionless amplitude and frequencies are known. Here we present a shortcut to calculate stochastic backgrounds of GWs produced from cosmological sources. For this approach it is not necessary to know in detail the energy flux emitted at each frequency. Knowing the characteristic values for the ``lumped'' dimensionless amplitude and frequency we show tha...

  19. Background independence in a background dependent renormalization group

    Science.gov (United States)

    Labus, Peter; Morris, Tim R.; Slade, Zöe H.

    2016-07-01

    Within the derivative expansion of conformally reduced gravity, the modified split Ward identities are shown to be compatible with the flow equations if and only if either the anomalous dimension vanishes or the cutoff profile is chosen to have a power-law form. No solutions exist if the Ward identities are incompatible. In the compatible case, a clear reason is found for why Ward identities can still forbid the existence of fixed points; however, for any cutoff profile, a background independent (and parametrization independent) flow equation is uncovered. Finally, expanding in vertices, the combined equations are shown generically to become either overconstrained or highly redundant beyond the six-point level.

  20. A study of the background corona near solar minimum

    Science.gov (United States)

    Saito, K.; Poland, A. I.; Munro, R. H.

    1977-01-01

    Equatorial and polar K and F coronal components during the declining phase of the solar cycle are studied through use of the white light coronagraph data obtained by Skylab. At this phase of the solar cycle, streams and holes dominate the equatorial corona (approximately 50 and 30% of the time, respectively) between 2.5 and 5.5 solar radii; however, two episodes are noted when equatorial background density of the corona could be distinguished. The derived background density is less than 15% below values predicted by the models of Newkirk (1967) and Saito (1970). The brightness of the F-corona is also discussed.

  1. Leaky-Wave Slot Array Antenna Fed by a Pin-Made Planar Dual Offset Gregorian Reflector System

    NARCIS (Netherlands)

    Ettorre, M.; Neto, A.; Gerini, G.; Maci, S.

    2008-01-01

    This work proposes a leaky-wave slot array antenna fed by a dual offset Gregorian reflector system realized by pins in a parallel plate waveguide. The radiating part of the antenna is composed by parallel slots etched on one side of the same parallel plate waveguide. The dual offset Gregorian reflec

  2. How much compensation is enough? A framework for incorporating uncertainty and time discounting when calculating offset ratios for impacted habitats

    NARCIS (Netherlands)

    Moilanen, A.; Teeffelen, van A.J.A.; Ben-Haim, Y.; Ferrier, S.

    2009-01-01

    Biodiversity offset areas may compensate for ecological damage caused by human activity elsewhere. One way of determining the offset ratio, or the compensation area needed, is to divide the present conservation value of the development site by the predicted future conservation value of a compensatio

  3. Investigation of LO-leakage cancellation and DC-offset influence on flicker-noise in X-band mixers

    DEFF Research Database (Denmark)

    Michaelsen, Rasmus; Johansen, Tom; Tamborg, Kjeld

    2012-01-01

    This paper describes an investigation on the influences in 1/f noise of LO-leakage and DC-offset cancellation for X-band mixers. Conditions for LO-leakage cancellation and zero DC-offset is derived. Measurements on a double balanced diode mixer shows an improvement in noise figure from 14.3dB to 12...

  4. Cosmic Microwave Background Acoustic Peak Locations

    CERN Document Server

    Pan, Zhen; Mulroe, Brigid; Narimani, Ali

    2016-01-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and twelve extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g., that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 degrees out of phase. However, there are large differences in expectations for extrema locations from simple analytic models vs. numerical calculations. Here we quantitatively explore the origin of these differences in gravitational potential tr...

  5. [Toothache with a neuropathic background].

    Science.gov (United States)

    Khatchaturian, V; de Wijer, A; Kalaykova, S I; Steenks, M H

    2015-03-01

    A 48-year old woman in good general health was referred to the orofacial pain clinic in a centre for special dentistry with a toothache in the premolar region of the left maxillary quadrant. The complaints had existed for 15 years and various dental treatments, including endodontic treatments, apical surgery, extraction and splint therapy, had not helped to alleviate the complaints. As a result of the fact that anti-epileptic drugs were able to reduce the pain it was concluded that this 'toothache' satisfied the criteria of an atypical odontalgia: 'toothache' with a neuropathic background. PMID:26181392

  6. Breast cancer - background and overview

    International Nuclear Information System (INIS)

    This summary is to provide the reader with a brief overview of the key concepts relating to epidemiology and etiology; clinical presentation and patterns of spread; Canadian guidelines for management; prognosis; and current Canadian screening recommendations in the diagnosis and treatment of breast cancer. This information will enable the reader to have the appropriate background knowledge before delving into the subsequent articles in this special CJMRT breast cancer edition. A variety of references have been provided for readers who are interested in more than a skeleton version of the current literature. (author)

  7. Band offsets for biaxially and uniaxially stressed silicon-germanium layers with arbitrary substrate and channel orientations

    Science.gov (United States)

    Eneman, Geert; Roussel, Philippe; Brunco, David Paul; Collaert, Nadine; Mocuta, Anda; Thean, Aaron

    2016-08-01

    The conduction and valence band offsets between a strained silicon-germanium layer and a silicon-germanium substrate are reported for arbitrary substrate and channel crystal orientations. The offsets are calculated both for the case of biaxial stress, corresponding approximately to the stress state of a thin strained channel in a planar field-effect transistor (FET), and for uniaxial stress, which is the approximate stress state for strained channels in a FinFET configuration. Significant orientation dependence is found for the conduction band offset, overall leading to the strongest electron quantum confinement in biaxial-tensile stressed channels on {100}-oriented substrates, and uniaxial-tensile stressed channels in the ⟨100⟩ and ⟨110⟩ directions. For biaxially stressed layers on {111} substrates, the conduction band offset is significantly smaller than for {100} or {110} directions. For the valence band offset, the dependence on crystal orientation is found to be small.

  8. Simulation of a two-pollutant, two-season pollution offset system for the Colorado River of Texas below Austin

    Science.gov (United States)

    Letson, David

    1992-05-01

    A pollution offset system is a discharge permit system in which transfers are made subject to a restriction that no violations of water quality standards occur at any location. Simulation of a pollution offset system with seasonal variation and multiple pollutants allows for comparison of the savings possible from these design features. A simulation model (Qual-TX) developed by the Texas Water Commission is applied to a case study region near Austin, Texas, yielding impact coefficients for an economic optimization model without investment whose least cost solution represents the theoretical equilibrium of a pollution offset system. The optimization model finds short-run savings of 17.5% for a pollution offset system, as compared to a command and control policy that would also achieve the dissolved oxygen standard. Seasonal variation in permit design produces minimal effects; virtually all savings come from allowing pollution offsets for the two different pollutants.

  9. Nonlinear Equations of Motion for Cantilever Rotor Blades in Hover with Pitch Link Flexibility, Twist, Precone, Droop, Sweep, Torque Offset, and Blade Root Offset

    Science.gov (United States)

    Hodges, D. H.

    1976-01-01

    Nonlinear equations of motion for a cantilever rotor blade are derived for the hovering flight condition. The blade is assumed to have twist, precone, droop, sweep, torque offset and blade root offset, and the elastic axis and the axes of center of mass, tension, and aerodynamic center coincident at the quarter chord. The blade is cantilevered in bending, but has a torsional root spring to simulate pitch link flexibility. Aerodynamic forces acting on the blade are derived from strip theory based on quasi-steady two-dimensional airfoil theory. The equations are hybrid, consisting of one integro-differential equation for root torsion and three integro-partial differential equations for flatwise and chordwise bending and elastic torsion. The equations are specialized for a uniform blade and reduced to nonlinear ordinary differential equations by Galerkin's method. They are linearized for small perturbation motions about the equilibrium operating condition. Modal analysis leads to formulation of a standard eigenvalue problem where the elements of the stability matrix depend on the solution of the equilibrium equations. Two different forms of the root torsion equation are derived that yield virtually identical numerical results. This provides a reasonable check for the accuracy of the equations.

  10. Limits of Astrophysics with Gravitational-Wave Backgrounds

    Science.gov (United States)

    Callister, Thomas; Sammut, Letizia; Qiu, Shi; Mandel, Ilya; Thrane, Eric

    2016-07-01

    The recent Advanced LIGO detection of gravitational waves from the binary black hole GW150914 suggests there exists a large population of merging binary black holes in the Universe. Although most are too distant to be individually resolved by advanced detectors, the superposition of gravitational waves from many unresolvable binaries is expected to create an astrophysical stochastic background. Recent results from the LIGO and Virgo Collaborations show that this astrophysical background is within reach of Advanced LIGO. In principle, the binary black hole background encodes interesting astrophysical properties, such as the mass distribution and redshift distribution of distant binaries. However, we show that this information will be difficult to extract with the current configuration of advanced detectors (and using current data analysis tools). Additionally, the binary black hole background also constitutes a foreground that limits the ability of advanced detectors to observe other interesting stochastic background signals, for example, from cosmic strings or phase transitions in the early Universe. We quantify this effect.

  11. [Cosmic Microwave Background (CMB) Anisotropies

    Science.gov (United States)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10-7, where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  12. Low background aspects of GERDA

    International Nuclear Information System (INIS)

    The GERDA experiment operates bare Germanium diodes enriched in 76Ge in an environment of pure liquid argon to search for neutrinoless double beta decay. A very low radioactive background is essential for the success of the experiment. We present here the research done in order to remove radio-impurities coming from the liquid argon, the stainless steel cryostat and the front-end electronics. We found that liquid argon can be purified efficiently from 222Rn. The main source of 222Rn in GERDA is the cryostat which emanates about 55 mBq. A thin copper shroud in the center of the cryostat was implemented to prevent radon from approaching the diodes. Gamma ray screening of radio-pure components for front-end electronics resulted in the development of a pre-amplifier with a total activity of less than 1 mBq 228Th.

  13. Polarization of Cosmic Microwave Background

    CERN Document Server

    Buzzelli, Alessandro; de Gasperis, Giancarlo; Vittorio, Nicola

    2016-01-01

    In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross-correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales.

  14. The Cosmic Background Imager 2

    CERN Document Server

    Taylor, Angela C; Allison, James R; Angelakis, Emmanouil; Bond, J Richard; Bronfman, Leonardo; Bustos, Ricardo; Davis, Richard J; Dickinson, Clive; Leech, Jamie; Mason, Brian S; Myers, Steven T; Pearson, Timothy J; Readhead, Anthony C S; Reeves, Rodrigo; Shepherd, Martin C; Sievers, Jonathan L

    2011-01-01

    We describe an upgrade to the Cosmic Background Imager instrument to increase its surface brightness sensitivity at small angular scales. The upgrade consisted of replacing the thirteen 0.9-m antennas with 1.4-m antennas incorporating a novel combination of design features, which provided excellent sidelobe and spillover performance for low manufacturing cost. Off-the-shelf spun primaries were used, and the secondary mirrors were oversized and shaped relative to a standard Cassegrain in order to provide an optimum compromise between aperture efficiency and low spillover lobes. Low-order distortions in the primary mirrors were compensated for by custom machining of the secondary mirrors. The secondaries were supported on a transparent dielectric foam cone to minimize scattering. The antennas were tested in the complete instrument, and the beam shape and spillover noise contributions were as expected. We demonstrate the performance of the telescope and the inter-calibration with the previous system using observ...

  15. Recognizing foreground-background interaction

    Science.gov (United States)

    Jenkins, Jeffrey; Szu, Harold

    2010-04-01

    Can the background affect a foreground target in distant, low-quality imagery? If it does, it might occur in our mind, or perhaps it may represent a snapshot of our early vision. An affirmative answer, one way or another, may affect our current understanding of this phenomena and potentially for related applications. How can we be sure about this in the psycho-physical sense? We begin with the physiology of our brain's homeostasis, of which an isothermal equilibrium is characterized by the minimum of Helmholtz isothermal Free Energy: A = U - T0S >= 0, where T0 = 37°C, the Boltzmann Entropy S = KB1n(W), and U is the unknown internal energy to be computed.

  16. Gauging the cosmic microwave background

    International Nuclear Information System (INIS)

    We provide a new derivation of the anisotropies of the cosmic microwave background (CMB), and find an exact expression that can be readily expanded perturbatively. Close attention is paid to gauge issues, with the motivation to examine the effect of super-Hubble modes on the CMB. We calculate a transfer function that encodes the behavior of the dipole, and examine its long-wavelength behavior. We show that contributions to the dipole from adiabatic super-Hubble modes are strongly suppressed, even in the presence of a cosmological constant, contrary to claims in the literature. We also introduce a naturally defined CMB monopole, which exhibits closely analogous long-wavelength behavior. We discuss the geometrical origin of this super-Hubble suppression, pointing out that it is a simple reflection of adiabaticity, and hence argue that it will occur regardless of the matter content.

  17. NLC and the background atmosphere above ALOMAR

    Directory of Open Access Journals (Sweden)

    J. Fiedler

    2011-02-01

    Full Text Available Noctilucent clouds (NLC have been measured by the Rayleigh/Mie/Raman-lidar at the ALOMAR research facility in Northern Norway (69° N, 16° E. From 1997 to 2010 NLC were detected during more than 1850 h on 440 different days. Colocated MF-radar measurements and calculations with the Leibniz-Institute Middle Atmosphere (LIMA- model are used to characterize the background atmosphere. Temperatures as well as horizontal winds at 83 km altitude show distinct differences during NLC compared to the absence of NLC. On seasonal mean it is colder and the winds are stronger westward when NLC are detected. The wind separation is a robust feature as it shows up in measurements as well as in model and it is consistent with the current understanding that lower temperatures support the existence of ice particles. For the whole 14-years data set there is no statistically significant relation between NLC occurrence and solar activity. On the other hand NLC occurrence and temperatures at 83 km show a significant anti-correlation, which suggests that the thermal state plays a major role for the existence of ice particles and dominates the pure Lyman-α influence on water vapor during certain years. We find the seasonal mean NLC altitudes to be correlated to both Lyman-α radiation and temperature. NLC above ALOMAR are strongly influenced by atmospheric tides. Diurnal and semidiurnal amplitudes and phases show partly pronounced year-to-year variations. In general, amplitudes as well as phases vary in a different manner. Amplitudes change by a factor of more than 3 and phases vary by up to 7 h. Such variability can impact NLC observations limited to fixed local times.

  18. NLC and the background atmosphere above ALOMAR

    Directory of Open Access Journals (Sweden)

    J. Fiedler

    2011-06-01

    Full Text Available Noctilucent clouds (NLC have been measured by the Rayleigh/Mie/Raman-lidar at the ALOMAR research facility in Northern Norway (69° N, 16° E. From 1997 to 2010 NLC were detected during more than 1850 h on 440 different days. Colocated MF-radar measurements and calculations with the Leibniz-Institute Middle Atmosphere (LIMA- model are used to characterize the background atmosphere. Temperatures as well as horizontal winds at 83 km altitude show distinct differences during NLC observations compared to when NLC are absent. The seasonally averaged temperature is lower and the winds are stronger westward when NLC are detected. The wind separation is a robust feature as it shows up in measurements as well as in model results and it is consistent with the current understanding that lower temperatures support the existence of ice particles. For the whole 14-year data set there is no statistically significant relation between NLC occurrence and solar Lyman-α radiation. On the other hand NLC occurrence and temperatures at 83 km show a significant anti-correlation, which suggests that the thermal state plays a major role for the existence of ice particles and dominates the pure Lyman-α influence on water vapor during certain years. We find the seasonal mean NLC altitudes to be correlated to both Lyman-α radiation and temperature. NLC above ALOMAR are strongly influenced by atmospheric tides. The cloud water content varies by a factor of 2.8 over the diurnal cycle. Diurnal and semidiurnal amplitudes and phases show some pronounced year-to-year variations. In general, amplitudes as well as phases vary in a different manner. Amplitudes change by a factor of more than 3 and phases vary by up to 7 h. Such variability could impact long-term NLC observations which do not cover the full diurnal cycle.

  19. A novel low-offset dynamic comparator for sub-1-V pipeline ADCs

    Institute of Scientific and Technical Information of China (English)

    Yang Jinda; Wang Xianbiao; Li Li; Cheng Xu; Guo Yawei; Zeng Xiaoyang

    2011-01-01

    A novel low-offset dynamic comparator for high-speed low-voltage analog-to-digital converters (ADCs) has been proposed.In the proposed comparator,a CMOS switch takes the place of the dynamic current sources in the differential comparator,which allows the differential input transistors still to operate in the saturation region at the comparing time.This gives the proposed comparator a low offset as the differential comparator while tolerating a sub-1-V supply voltage.Additionally,it also features a larger input swing,less sensitivity to common mode voltage,and a simple relationship between the input and reference voltage.This proposed comparator with two traditional comparators has been realized by SMIC 0.13 μm CMOS technology.The contrast experimental resuits verify these advantages over conventional comparators.It has been used in a 12-bit 100-MS/s pipeline ADC.

  20. Characteristics of the orbital rotation in dual-beam fiber-optic trap with transverse offset.

    Science.gov (United States)

    Chen, Xinlin; Xiao, Guangzong; Yang, Kaiyong; Xiong, Wei; Luo, Hui

    2016-07-25

    The orbital rotation is an important type of motion of trapped particles apart from translation and spin rotation. It could be realized by introducing a transverse offset to the dual-beam fiber-optic trap. The characteristics (e.g. rotation perimeter and frequency) of the orbital rotation have been analyzed in this article. We demonstrate the influences of offset distance, beam waist separation distance, light power, and radius of the microsphere by both experimental and numerical work. The experiment results, i.e. orbital rotation perimeter and frequency as functions of these parameters, are consistent with the theoretical model in the present work. The orbital rotation amplitude and frequency could be exactly controlled by varying these parameters. This controllable orbital rotation can be easily applied to the area where microfluidic mixing is required. PMID:27464147