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Recorded Data (recorded + data)
Selected AbstractsA Probabilistic Framework for Bayesian Adaptive Forecasting of Project ProgressCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2007Paolo Gardoni An adaptive Bayesian updating method is used to assess the unknown model parameters based on recorded data and pertinent prior information. Recorded data can include equality, upper bound, and lower bound data. The proposed approach properly accounts for all the prevailing uncertainties, including model errors arising from an inaccurate model form or missing variables, measurement errors, statistical uncertainty, and volitional uncertainty. As an illustration of the proposed approach, the project progress and final time-to-completion of an example project are forecasted. For this illustration construction of civilian nuclear power plants in the United States is considered. This application considers two cases (1) no information is available prior to observing the actual progress data of a specified plant and (2) the construction progress of eight other nuclear power plants is available. The example shows that an informative prior is important to make accurate predictions when only a few records are available. This is also the time when forecasts are most valuable to the project manager. Having or not having prior information does not have any practical effect on the forecast when progress on a significant portion of the project has been recorded. [source] Using Scanner Technology to Collect Expenditure Data,FISCAL STUDIES, Issue 3-4 2009Andrew Leicester C81; C83; C33; C41 Abstract In terms of collecting panel expenditure data, there are trade-offs between the demands imposed on respondents and the detail and coverage of data collected. Comprehensive spending data tend to be cross-sectional whilst panel studies include only limited, aggregated expenditure questions. Recently, economists have begun to use detailed, bar-code-level spending data from household panels collected by market research companies. However, there has not been a detailed assessment of the strengths and weaknesses of this collection method or its implications for the recorded data. This paper seeks to fill this gap by providing an in-depth examination of data from one company, Taylor Nelson Sofres (TNS), recording grocery purchases over five years. We assess how far the ongoing demands of participation lead to ,fatigue' in respondents' recording of their spending and the implications for household attrition, and we provide a detailed comparison of the expenditure data collected by TNS and the well-established Expenditure and Food Survey (EFS). Broadly, we suggest that problems of fatigue and attrition may not be particularly severe, though there are differences in expenditures that cannot be attributed to demographic or time effects and may be suggestive of survey mode effects. [source] Reverse modelling for seismic event characterizationGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2005Dirk Gajewski SUMMARY The localization of seismic events is of utmost importance in seismology and exploration. Current techniques rely on the fact that the recorded event is detectable at most of the stations of a seismic network. Weak events, not visible in the individual seismogram of the network, are missed out. We present an approach, where no picking of events in the seismograms of the recording network is required. The observed wavefield of the network is reversed in time and then considered as the boundary value for the reverse modelling. Assuming the correct velocity model, the reversely modelled wavefield focuses on the hypocentre of the seismic event. The origin time of the event is given by the time where maximum focussing is observed. The spatial extent of the focus resembles the resolution power of the recorded wavefield and the acquisition. This automatically provides the uncertainty in the localization with respect to the bandwidth of the recorded data. The method is particularly useful for the upcoming large passive networks since no picking is required. It has great potential for localizing very weak events, not detectable in the individual seismogram, since the reverse modelling sums the energy of all recorded traces and, therefore, enhances the signal-to-noise ratio similar to stacking in seismic exploration. The method is demonstrated by 2-D and 3-D numerical case studies, which show the potential of the technique. Events with a S/N ratio smaller than 1 where the events cannot be identified in the individual seismogram of the network are localized very well by the method. [source] Low-frequency passive seismic experiments in Abu Dhabi, United Arab Emirates: implications for hydrocarbon detectionGEOPHYSICAL PROSPECTING, Issue 5 2010Mohammed Y. Ali ABSTRACT Low-frequency passive seismic experiments utilizing arrays of 3-component broadband seismometers were conducted over two sites in the emirate of Abu Dhabi in the United Arab Emirates. The experiments were conducted in the vicinity of a producing oilfield and around a dry exploration well to better understand the characteristics and origins of microtremor signals (1,6 Hz), which had been reported as occurring exclusively above several hydrocarbon reservoirs in the region. The results of the experiments revealed that a strong correlation exists between the recorded ambient noise and observed meteorological and anthropogenic noises. In the frequency range of 0.15,0.4 Hz, the dominant feature is a double-frequency microseism peak generated by the non-linear interactions of storm induced surface waves in the Arabian Sea. We observed that the double-frequency microseism displays a high variability in spectral amplitude, with the strongest amplitude occurring when Cyclone Gonu was battering the eastern coast of Oman; this noise was present at both sites and so is not a hydrocarbon indicator. Moreover, this study found that very strong microtremor signals in the frequency range of 2,3 Hz were present in all of the locations surveyed, both within and outside of the reservoir boundary and surrounding the dry exploration well. This microtremor signal has no clear correlation with the microseism signals but significant variations in the characteristics of the signals were observed between daytime and nighttime recording periods that clearly correlate with human activity. High-resolution frequency-wavenumber (f - k) spectral analyses were performed on the recorded data to determine apparent velocities and azimuths of the wavefronts for the microseism and microtremor events. The f - k analyses confirmed that the double-frequency microseism originates from wave activity in the Arabian Sea, while the microtremor events have an azimuth pointing towards the nearest motorways, indicating that they are probably being excited by traffic noise. Results drawn from particle motion studies confirm these observations. The vertical-to-horizontal spectral ratios of the data acquired in both experiments show peaks around 2.5,3 Hz with no dependence on the presence or absence of subsurface hydrocarbons. Therefore, this method should not be used as a direct hydrocarbon indicator in these environments. Furthermore, the analyses provide no direct evidence to indicate that earthquakes are capable of stimulating the hydrocarbon reservoir in a way that could modify the spectral amplitude of the microtremor signal. [source] Behavioral change related to Wenchuan devastating earthquake in miceBIOELECTROMAGNETICS, Issue 8 2009Yonghong Li Abstract It has been suggested that some animals are much more capable of perceiving certain kinds of geophysical stimuli which may precede earthquakes than humans, but the anecdotal phenomena or stories about unusual animal behaviors prior to an earthquake should be interpreted with objective data. During the Wenchuan magnitude 8.0 earthquake that happened in Wenchuan county (31.0° north latitude, 103.4° east longitude) of Sichuan province, China, on May 12, 2008, eight mice were monitored for locomotor activity and circadian rhythm in constant darkness with temperature 22,24 °C and humidity 55,65% for 38 days. The ongoing monitoring of locomotor activity of mice in our laboratory made it possible to design a posteriori study investigating whether the earthquake was associated with any change in animal behavior. Based on analyzing the recorded data with single cosinor, we found that the locomotor activity dramatically decreased in six of these eight mice on day 3 before the earthquake, and the circadian rhythm of their locomotor activity was no longer detected. The behavioral change lasted for 6 days before the locomotor activity returned to its original state. Analyses of concurrent geomagnetic data showed a higher total intensity during the span when the circadian rhythm in locomotor activity weakened. These results indicated that the behaviors, including circadian rhythm and activity, in these mice indeed changed prior to the earthquake, and the behavioral change might be associated with a change of geomagnetic intensity. Bioelectromagnetics 30:613,620, 2009. © 2009 Wiley-Liss, Inc. [source] The copper-containing amine oxidase from Arthrobacter globiformis: refinement at 1.55 and 2.20,Å resolution in two crystal formsACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2006David B. Langley Copper-containing amine oxidases are found in all the major kingdoms of life. They catalyse the oxidation of organic amines in the presence of molecular dioxygen to aldehydes and hydrogen peroxide. The catalytic centres contain a Cu atom and a topaquinone cofactor formed autocatalytically from a tyrosine residue in the presence of Cu and molecular oxygen. The structure of the Cu-containing amine oxidase from Arthrobacter globiformis, which was previously refined at 1.8,Å resolution in space group C2 with unit-cell parameters a = 157.84, b = 63.24, c = 91.98,Å, , = 112.0° [Wilce et al. (1997), Biochemistry, 36, 16116,16133], has been re-refined with newly recorded data at 1.55,Å resolution. The structure has also been solved and refined at 2.2,Å resolution in a new crystal form, space group C2, with unit-cell parameters a = 158.04, b = 64.06, c = 69.69,Å, , = 111.7°. [source] Analysis of Single-Molecule Fluorescence Spectroscopic Data with a Markov-Modulated Poisson ProcessCHEMPHYSCHEM, Issue 14 2009Mark Jäger Dr. Abstract We present a photon-by-photon analysis framework for the evaluation of data from single-molecule fluorescence spectroscopy (SMFS) experiments using a Markov-modulated Poisson process (MMPP). A MMPP combines a discrete (and hidden) Markov process with an additional Poisson process reflecting the observation of individual photons. The algorithmic framework is used to automatically analyze the dynamics of the complex formation and dissociation of Cu2+ ions with the bidentate ligand 2,2,-bipyridine-4,4,dicarboxylic acid in aqueous media. The process of association and dissociation of Cu2+ ions is monitored with SMFS. The dcbpy-DNA conjugate can exist in two or more distinct states which influence the photon emission rates. The advantage of a photon-by-photon analysis is that no information is lost in preprocessing steps. Different model complexities are investigated in order to best describe the recorded data and to determine transition rates on a photon-by-photon basis. The main strength of the method is that it allows to detect intermittent phenomena which are masked by binning and that are difficult to find using correlation techniques when they are short-lived. [source] | |||||||||||||