Targeted estimation of nuisance parameters to obtain valid statistical inference.

PubMed

van der Laan, Mark J

2014-01-01

In order to obtain concrete results, we focus on estimation of the treatment specific mean, controlling for all measured baseline covariates, based on observing independent and identically distributed copies of a random variable consisting of baseline covariates, a subsequently assigned binary treatment, and a final outcome. The statistical model only assumes possible restrictions on the conditional distribution of treatment, given the covariates, the so-called propensity score. Estimators of the treatment specific mean involve estimation of the propensity score and/or estimation of the conditional mean of the outcome, given the treatment and covariates. In order to make these estimators asymptotically unbiased at any data distribution in the statistical model, it is essential to use data-adaptive estimators of these nuisance parameters such as ensemble learning, and specifically super-learning. Because such estimators involve optimal trade-off of bias and variance w.r.t. the infinite dimensional nuisance parameter itself, they result in a sub-optimal bias/variance trade-off for the resulting real-valued estimator of the estimand. We demonstrate that additional targeting of the estimators of these nuisance parameters guarantees that this bias for the estimand is second order and thereby allows us to prove theorems that establish asymptotic linearity of the estimator of the treatment specific mean under regularity conditions. These insights result in novel targeted minimum loss-based estimators (TMLEs) that use ensemble learning with additional targeted bias reduction to construct estimators of the nuisance parameters. In particular, we construct collaborative TMLEs (C-TMLEs) with known influence curve allowing for statistical inference, even though these C-TMLEs involve variable selection for the propensity score based on a criterion that measures how effective the resulting fit of the propensity score is in removing bias for the estimand. As a particular special

The Use of Artificial Neural Networks to Estimate Speech Intelligibility from Acoustic Variables: A Preliminary Analysis.

ERIC Educational Resources Information Center

Metz, Dale Evan; And Others

1992-01-01

A preliminary scheme for estimating the speech intelligibility of hearing-impaired speakers from acoustic parameters, using a computerized artificial neural network to process mathematically the acoustic input variables, is outlined. Tests with 60 hearing-impaired speakers found the scheme to be highly accurate in identifying speakers separated by…

Application of Boosting Regression Trees to Preliminary Cost Estimation in Building Construction Projects

PubMed Central

2015-01-01

Among the recent data mining techniques available, the boosting approach has attracted a great deal of attention because of its effective learning algorithm and strong boundaries in terms of its generalization performance. However, the boosting approach has yet to be used in regression problems within the construction domain, including cost estimations, but has been actively utilized in other domains. Therefore, a boosting regression tree (BRT) is applied to cost estimations at the early stage of a construction project to examine the applicability of the boosting approach to a regression problem within the construction domain. To evaluate the performance of the BRT model, its performance was compared with that of a neural network (NN) model, which has been proven to have a high performance in cost estimation domains. The BRT model has shown results similar to those of NN model using 234 actual cost datasets of a building construction project. In addition, the BRT model can provide additional information such as the importance plot and structure model, which can support estimators in comprehending the decision making process. Consequently, the boosting approach has potential applicability in preliminary cost estimations in a building construction project. PMID:26339227

Application of Boosting Regression Trees to Preliminary Cost Estimation in Building Construction Projects.

PubMed

Shin, Yoonseok

2015-01-01

Among the recent data mining techniques available, the boosting approach has attracted a great deal of attention because of its effective learning algorithm and strong boundaries in terms of its generalization performance. However, the boosting approach has yet to be used in regression problems within the construction domain, including cost estimations, but has been actively utilized in other domains. Therefore, a boosting regression tree (BRT) is applied to cost estimations at the early stage of a construction project to examine the applicability of the boosting approach to a regression problem within the construction domain. To evaluate the performance of the BRT model, its performance was compared with that of a neural network (NN) model, which has been proven to have a high performance in cost estimation domains. The BRT model has shown results similar to those of NN model using 234 actual cost datasets of a building construction project. In addition, the BRT model can provide additional information such as the importance plot and structure model, which can support estimators in comprehending the decision making process. Consequently, the boosting approach has potential applicability in preliminary cost estimations in a building construction project.

Preliminary Estimation of Kappa Parameter in Croatia

NASA Astrophysics Data System (ADS)

Stanko, Davor; Markušić, Snježana; Ivančić, Ines; Mario, Gazdek; Gülerce, Zeynep

2017-12-01

Spectral parameter kappa κ is used to describe spectral amplitude decay “crash syndrome” at high frequencies. The purpose of this research is to estimate spectral parameter kappa for the first time in Croatia based on small and moderate earthquakes. Recordings of local earthquakes with magnitudes higher than 3, epicentre distances less than 150 km, and focal depths less than 30 km from seismological stations in Croatia are used. The value of kappa was estimated from the acceleration amplitude spectrum of shear waves from the slope of the high-frequency part where the spectrum starts to decay rapidly to a noise floor. Kappa models as a function of a site and distance were derived from a standard linear regression of kappa-distance dependence. Site kappa was determined from the extrapolation of the regression line to a zero distance. The preliminary results of site kappa across Croatia are promising. In this research, these results are compared with local site condition parameters for each station, e.g. shear wave velocity in the upper 30 m from geophysical measurements and with existing global shear wave velocity - site kappa values. Spatial distribution of individual kappa’s is compared with the azimuthal distribution of earthquake epicentres. These results are significant for a couple of reasons: to extend the knowledge of the attenuation of near-surface crust layers of the Dinarides and to provide additional information on the local earthquake parameters for updating seismic hazard maps of studied area. Site kappa can be used in the re-creation, and re-calibration of attenuation of peak horizontal and/or vertical acceleration in the Dinarides area since information on the local site conditions were not included in the previous studies.

NMR permeability estimators in 'chalk' carbonate rocks obtained under different relaxation times and MICP size scalings

NASA Astrophysics Data System (ADS)

Rios, Edmilson Helton; Figueiredo, Irineu; Moss, Adam Keith; Pritchard, Timothy Neil; Glassborow, Brent Anthony; Guedes Domingues, Ana Beatriz; Bagueira de Vasconcellos Azeredo, Rodrigo

2016-07-01

The effect of the selection of different nuclear magnetic resonance (NMR) relaxation times for permeability estimation is investigated for a set of fully brine-saturated rocks acquired from Cretaceous carbonate reservoirs in the North Sea and Middle East. Estimators that are obtained from the relaxation times based on the Pythagorean means are compared with estimators that are obtained from the relaxation times based on the concept of a cumulative saturation cut-off. Select portions of the longitudinal (T1) and transverse (T2) relaxation-time distributions are systematically evaluated by applying various cut-offs, analogous to the Winland-Pittman approach for mercury injection capillary pressure (MICP) curves. Finally, different approaches to matching the NMR and MICP distributions using different mean-based scaling factors are validated based on the performance of the related size-scaled estimators. The good results that were obtained demonstrate possible alternatives to the commonly adopted logarithmic mean estimator and reinforce the importance of NMR-MICP integration to improving carbonate permeability estimates.

Stability of individual loudness functions obtained by magnitude estimation and production

NASA Technical Reports Server (NTRS)

Hellman, R. P.

1981-01-01

A correlational analysis of individual magnitude estimation and production exponents at the same frequency is performed, as is an analysis of individual exponents produced in different sessions by the same procedure across frequency (250, 1000, and 3000 Hz). Taken as a whole, the results show that individual exponent differences do not decrease by counterbalancing magnitude estimation with magnitude production and that individual exponent differences remain stable over time despite changes in stimulus frequency. Further results show that although individual magnitude estimation and production exponents do not necessarily obey the .6 power law, it is possible to predict the slope of an equal-sensation function averaged for a group of listeners from individual magnitude estimation and production data. On the assumption that individual listeners with sensorineural hearing also produce stable and reliable magnitude functions, it is also shown that the slope of the loudness-recruitment function measured by magnitude estimation and production can be predicted for individuals with bilateral losses of long duration. Results obtained in normal and pathological ears thus suggest that individual listeners can produce loudness judgements that reveal, although indirectly, the input-output characteristic of the auditory system.

Preliminary estimates of radiation exposures for manned interplanetary missions from anomalously large solar flare events

NASA Technical Reports Server (NTRS)

Townsend, Lawrence W.; Nealy, John E.; Wilson, John W.

1988-01-01

Preliminary estimates of radiation exposures for manned interplanetary missions resulting from anomalously large solar flare events are presented. The calculations use integral particle fluences for the February 1956, November 1960, and August 1972 events as inputs into the Langley Research Center nucleon transport code BRYNTRN. This deterministic code transports primary and secondary nucleons (protons and neutrons) through any number of layers of target material of arbitrary thickness and composition. Contributions from target nucleus fragmentation and recoil are also included. Estimates of 5 cm depth doses and dose equivalents in tissue are presented behind various thicknesses of aluminum, water, and composite aluminum/water shields for each of the three solar flare events.

A preliminary structural analysis of space-base living quarters modules to verify a weight-estimating technique

NASA Technical Reports Server (NTRS)

Grissom, D. S.; Schneider, W. C.

1971-01-01

The determination of a base line (minimum weight) design for the primary structure of the living quarters modules in an earth-orbiting space base was investigated. Although the design is preliminary in nature, the supporting analysis is sufficiently thorough to provide a reasonably accurate weight estimate of the major components that are considered to comprise the structural weight of the space base.

Maximum likelihood estimation for predicting the probability of obtaining variable shortleaf pine regeneration densities

Treesearch

Thomas B. Lynch; Jean Nkouka; Michael M. Huebschmann; James M. Guldin

2003-01-01

A logistic equation is the basis for a model that predicts the probability of obtaining regeneration at specified densities. The density of regeneration (trees/ha) for which an estimate of probability is desired can be specified by means of independent variables in the model. When estimating parameters, the dependent variable is set to 1 if the regeneration density (...

Obtaining Cue Rate Estimates for Some Mysticete Species using Existing Data

DTIC Science & Technology

2014-09-30

primary focus is to obtain cue rates for humpback whales (Megaptera novaeangliae) off the California coast and on the PMRF range. To our knowledge, no... humpback whale cue rates have been calculated for these populations. Once a cue rate is estimated for the populations of humpback whales off the...rates for humpback whales on breeding grounds, in addition to average cue rates for other species of mysticete whales . Cue rates of several other

Reliability of fish size estimates obtained from multibeam imaging sonar

USGS Publications Warehouse

Hightower, Joseph E.; Magowan, Kevin J.; Brown, Lori M.; Fox, Dewayne A.

2013-01-01

Multibeam imaging sonars have considerable potential for use in fisheries surveys because the video-like images are easy to interpret, and they contain information about fish size, shape, and swimming behavior, as well as characteristics of occupied habitats. We examined images obtained using a dual-frequency identification sonar (DIDSON) multibeam sonar for Atlantic sturgeon Acipenser oxyrinchus oxyrinchus, striped bass Morone saxatilis, white perch M. americana, and channel catfish Ictalurus punctatus of known size (20–141 cm) to determine the reliability of length estimates. For ranges up to 11 m, percent measurement error (sonar estimate – total length)/total length × 100 varied by species but was not related to the fish's range or aspect angle (orientation relative to the sonar beam). Least-square mean percent error was significantly different from 0.0 for Atlantic sturgeon (x̄  =  −8.34, SE  =  2.39) and white perch (x̄  = 14.48, SE  =  3.99) but not striped bass (x̄  =  3.71, SE  =  2.58) or channel catfish (x̄  = 3.97, SE  =  5.16). Underestimating lengths of Atlantic sturgeon may be due to difficulty in detecting the snout or the longer dorsal lobe of the heterocercal tail. White perch was the smallest species tested, and it had the largest percent measurement errors (both positive and negative) and the lowest percentage of images classified as good or acceptable. Automated length estimates for the four species using Echoview software varied with position in the view-field. Estimates tended to be low at more extreme azimuthal angles (fish's angle off-axis within the view-field), but mean and maximum estimates were highly correlated with total length. Software estimates also were biased by fish images partially outside the view-field and when acoustic crosstalk occurred (when a fish perpendicular to the sonar and at relatively close range is detected in the side lobes of adjacent beams). These sources of

A fully redundant double difference algorithm for obtaining minimum variance estimates from GPS observations

NASA Technical Reports Server (NTRS)

Melbourne, William G.

1986-01-01

In double differencing a regression system obtained from concurrent Global Positioning System (GPS) observation sequences, one either undersamples the system to avoid introducing colored measurement statistics, or one fully samples the system incurring the resulting non-diagonal covariance matrix for the differenced measurement errors. A suboptimal estimation result will be obtained in the undersampling case and will also be obtained in the fully sampled case unless the color noise statistics are taken into account. The latter approach requires a least squares weighting matrix derived from inversion of a non-diagonal covariance matrix for the differenced measurement errors instead of inversion of the customary diagonal one associated with white noise processes. Presented is the so-called fully redundant double differencing algorithm for generating a weighted double differenced regression system that yields equivalent estimation results, but features for certain cases a diagonal weighting matrix even though the differenced measurement error statistics are highly colored.

Use of NMR logging to obtain estimates of hydraulic conductivity in the High Plains aquifer, Nebraska, USA

USGS Publications Warehouse

Dlubac, Katherine; Knight, Rosemary; Song, Yi-Qiao; Bachman, Nate; Grau, Ben; Cannia, Jim; Williams, John

2013-01-01

Hydraulic conductivity (K) is one of the most important parameters of interest in groundwater applications because it quantifies the ease with which water can flow through an aquifer material. Hydraulic conductivity is typically measured by conducting aquifer tests or wellbore flow (WBF) logging. Of interest in our research is the use of proton nuclear magnetic resonance (NMR) logging to obtain information about water-filled porosity and pore space geometry, the combination of which can be used to estimate K. In this study, we acquired a suite of advanced geophysical logs, aquifer tests, WBF logs, and sidewall cores at the field site in Lexington, Nebraska, which is underlain by the High Plains aquifer. We first used two empirical equations developed for petroleum applications to predict K from NMR logging data: the Schlumberger Doll Research equation (KSDR) and the Timur-Coates equation (KT-C), with the standard empirical constants determined for consolidated materials. We upscaled our NMR-derived K estimates to the scale of the WBF-logging K(KWBF-logging) estimates for comparison. All the upscaled KT-C estimates were within an order of magnitude of KWBF-logging and all of the upscaled KSDR estimates were within 2 orders of magnitude of KWBF-logging. We optimized the fit between the upscaled NMR-derived K and KWBF-logging estimates to determine a set of site-specific empirical constants for the unconsolidated materials at our field site. We conclude that reliable estimates of K can be obtained from NMR logging data, thus providing an alternate method for obtaining estimates of K at high levels of vertical resolution.

Probabilities and statistics for backscatter estimates obtained by a scatterometer with applications to new scatterometer design data

NASA Technical Reports Server (NTRS)

Pierson, Willard J., Jr.

1989-01-01

The values of the Normalized Radar Backscattering Cross Section (NRCS), sigma (o), obtained by a scatterometer are random variables whose variance is a known function of the expected value. The probability density function can be obtained from the normal distribution. Models for the expected value obtain it as a function of the properties of the waves on the ocean and the winds that generated the waves. Point estimates of the expected value were found from various statistics given the parameters that define the probability density function for each value. Random intervals were derived with a preassigned probability of containing that value. A statistical test to determine whether or not successive values of sigma (o) are truly independent was derived. The maximum likelihood estimates for wind speed and direction were found, given a model for backscatter as a function of the properties of the waves on the ocean. These estimates are biased as a result of the terms in the equation that involve natural logarithms, and calculations of the point estimates of the maximum likelihood values are used to show that the contributions of the logarithmic terms are negligible and that the terms can be omitted.

Batch Effect Confounding Leads to Strong Bias in Performance Estimates Obtained by Cross-Validation

PubMed Central

Delorenzi, Mauro

2014-01-01

Background With the large amount of biological data that is currently publicly available, many investigators combine multiple data sets to increase the sample size and potentially also the power of their analyses. However, technical differences (“batch effects”) as well as differences in sample composition between the data sets may significantly affect the ability to draw generalizable conclusions from such studies. Focus The current study focuses on the construction of classifiers, and the use of cross-validation to estimate their performance. In particular, we investigate the impact of batch effects and differences in sample composition between batches on the accuracy of the classification performance estimate obtained via cross-validation. The focus on estimation bias is a main difference compared to previous studies, which have mostly focused on the predictive performance and how it relates to the presence of batch effects. Data We work on simulated data sets. To have realistic intensity distributions, we use real gene expression data as the basis for our simulation. Random samples from this expression matrix are selected and assigned to group 1 (e.g., ‘control’) or group 2 (e.g., ‘treated’). We introduce batch effects and select some features to be differentially expressed between the two groups. We consider several scenarios for our study, most importantly different levels of confounding between groups and batch effects. Methods We focus on well-known classifiers: logistic regression, Support Vector Machines (SVM), k-nearest neighbors (kNN) and Random Forests (RF). Feature selection is performed with the Wilcoxon test or the lasso. Parameter tuning and feature selection, as well as the estimation of the prediction performance of each classifier, is performed within a nested cross-validation scheme. The estimated classification performance is then compared to what is obtained when applying the classifier to independent data. PMID:24967636

A Nonlinear Dynamics-Based Estimator for Functional Electrical Stimulation: Preliminary Results From Lower-Leg Extension Experiments.

PubMed

Allen, Marcus; Zhong, Qiang; Kirsch, Nicholas; Dani, Ashwin; Clark, William W; Sharma, Nitin

2017-12-01

Miniature inertial measurement units (IMUs) are wearable sensors that measure limb segment or joint angles during dynamic movements. However, IMUs are generally prone to drift, external magnetic interference, and measurement noise. This paper presents a new class of nonlinear state estimation technique called state-dependent coefficient (SDC) estimation to accurately predict joint angles from IMU measurements. The SDC estimation method uses limb dynamics, instead of limb kinematics, to estimate the limb state. Importantly, the nonlinear limb dynamic model is formulated into state-dependent matrices that facilitate the estimator design without performing a Jacobian linearization. The estimation method is experimentally demonstrated to predict knee joint angle measurements during functional electrical stimulation of the quadriceps muscle. The nonlinear knee musculoskeletal model was identified through a series of experiments. The SDC estimator was then compared with an extended kalman filter (EKF), which uses a Jacobian linearization and a rotation matrix method, which uses a kinematic model instead of the dynamic model. Each estimator's performance was evaluated against the true value of the joint angle, which was measured through a rotary encoder. The experimental results showed that the SDC estimator, the rotation matrix method, and EKF had root mean square errors of 2.70°, 2.86°, and 4.42°, respectively. Our preliminary experimental results show the new estimator's advantage over the EKF method but a slight advantage over the rotation matrix method. However, the information from the dynamic model allows the SDC method to use only one IMU to measure the knee angle compared with the rotation matrix method that uses two IMUs to estimate the angle.

Estimation of desmosponge (Porifera, Demospongiae) larval settlement rates from short-term recruitment rates: Preliminary experiments

NASA Astrophysics Data System (ADS)

Zea, Sven

1992-09-01

During a study of the spatial and temporal patterns of desmosponge (Porifera, Demospongiae) recruitment on rocky and coral reef habitats of Santa Marta, Colombian Caribbean Sea, preliminary attempts were made to estimate actual settlement rates from short-term (1 to a few days) recruitment censuses. Short-term recruitment rates on black, acrylic plastic plates attached to open, non-cryptic substratum by anchor screws were low and variable (0 5 recruits/plate in 1 2 days, sets of n=5 10 plates), but reflected the depth and seasonal trends found using mid-term (1 to a few months) censusing intervals. Moreover, mortality of recruits during 1 2 day intervals was low (0 12%). Thus, short-term censusing intervals can be used to estimate actual settlement rates. To be able to make statistical comparisons, however, it is necessary to increase the number of recruits per census by pooling data of n plates per set, and to have more than one set per site or treatment.

Preliminary Results Obtained in Integrated Safety Analysis of NASA Aviation Safety Program Technologies

NASA Technical Reports Server (NTRS)

Reveley, Mary S.

2003-01-01

The goal of the NASA Aviation Safety Program (AvSP) is to develop and demonstrate technologies that contribute to a reduction in the aviation fatal accident rate by a factor of 5 by the year 2007 and by a factor of 10 by the year 2022. Integrated safety analysis of day-to-day operations and risks within those operations will provide an understanding of the Aviation Safety Program portfolio. Safety benefits analyses are currently being conducted. Preliminary results for the Synthetic Vision Systems (SVS) and Weather Accident Prevention (WxAP) projects of the AvSP have been completed by the Logistics Management Institute under a contract with the NASA Glenn Research Center. These analyses include both a reliability analysis and a computer simulation model. The integrated safety analysis method comprises two principal components: a reliability model and a simulation model. In the reliability model, the results indicate how different technologies and systems will perform in normal, degraded, and failed modes of operation. In the simulation, an operational scenario is modeled. The primary purpose of the SVS project is to improve safety by providing visual-flightlike situation awareness during instrument conditions. The current analyses are an estimate of the benefits of SVS in avoiding controlled flight into terrain. The scenario modeled has an aircraft flying directly toward a terrain feature. When the flight crew determines that the aircraft is headed toward an obstruction, the aircraft executes a level turn at speed. The simulation is ended when the aircraft completes the turn.

Irrigated rice area estimation using remote sensing techniques: Project's proposal and preliminary results. [Rio Grande do Sul, Brazil

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Deassuncao, G. V.; Moreira, M. A.; Novaes, R. A.

1984-01-01

The development of a methodology for annual estimates of irrigated rice crop in the State of Rio Grande do Sul, Brazil, using remote sensing techniques is proposed. The project involves interpretation, digital analysis, and sampling techniques of LANDSAT imagery. Results are discussed from a preliminary phase for identifying and evaluating irrigated rice crop areas in four counties of the State, for the crop year 1982/1983. This first phase involved just visual interpretation techniques of MSS/LANDSAT images.

Estimation of spectral distribution of sky radiance using a commercial digital camera.

PubMed

Saito, Masanori; Iwabuchi, Hironobu; Murata, Isao

2016-01-10

Methods for estimating spectral distribution of sky radiance from images captured by a digital camera and for accurately estimating spectral responses of the camera are proposed. Spectral distribution of sky radiance is represented as a polynomial of the wavelength, with coefficients obtained from digital RGB counts by linear transformation. The spectral distribution of radiance as measured is consistent with that obtained by spectrometer and radiative transfer simulation for wavelengths of 430-680 nm, with standard deviation below 1%. Preliminary applications suggest this method is useful for detecting clouds and studying the relation between irradiance at the ground and cloud distribution.

A Computationally Efficient Method for Polyphonic Pitch Estimation

NASA Astrophysics Data System (ADS)

Zhou, Ruohua; Reiss, Joshua D.; Mattavelli, Marco; Zoia, Giorgio

2009-12-01

This paper presents a computationally efficient method for polyphonic pitch estimation. The method employs the Fast Resonator Time-Frequency Image (RTFI) as the basic time-frequency analysis tool. The approach is composed of two main stages. First, a preliminary pitch estimation is obtained by means of a simple peak-picking procedure in the pitch energy spectrum. Such spectrum is calculated from the original RTFI energy spectrum according to harmonic grouping principles. Then the incorrect estimations are removed according to spectral irregularity and knowledge of the harmonic structures of the music notes played on commonly used music instruments. The new approach is compared with a variety of other frame-based polyphonic pitch estimation methods, and results demonstrate the high performance and computational efficiency of the approach.

Accuracy of patient-specific organ dose estimates obtained using an automated image segmentation algorithm.

PubMed

Schmidt, Taly Gilat; Wang, Adam S; Coradi, Thomas; Haas, Benjamin; Star-Lack, Josh

2016-10-01

The overall goal of this work is to develop a rapid, accurate, and automated software tool to estimate patient-specific organ doses from computed tomography (CT) scans using simulations to generate dose maps combined with automated segmentation algorithms. This work quantified the accuracy of organ dose estimates obtained by an automated segmentation algorithm. We hypothesized that the autosegmentation algorithm is sufficiently accurate to provide organ dose estimates, since small errors delineating organ boundaries will have minimal effect when computing mean organ dose. A leave-one-out validation study of the automated algorithm was performed with 20 head-neck CT scans expertly segmented into nine regions. Mean organ doses of the automatically and expertly segmented regions were computed from Monte Carlo-generated dose maps and compared. The automated segmentation algorithm estimated the mean organ dose to be within 10% of the expert segmentation for regions other than the spinal canal, with the median error for each organ region below 2%. In the spinal canal region, the median error was [Formula: see text], with a maximum absolute error of 28% for the single-atlas approach and 11% for the multiatlas approach. The results demonstrate that the automated segmentation algorithm can provide accurate organ dose estimates despite some segmentation errors.

Accuracy of patient-specific organ dose estimates obtained using an automated image segmentation algorithm

PubMed Central

Schmidt, Taly Gilat; Wang, Adam S.; Coradi, Thomas; Haas, Benjamin; Star-Lack, Josh

2016-01-01

Abstract. The overall goal of this work is to develop a rapid, accurate, and automated software tool to estimate patient-specific organ doses from computed tomography (CT) scans using simulations to generate dose maps combined with automated segmentation algorithms. This work quantified the accuracy of organ dose estimates obtained by an automated segmentation algorithm. We hypothesized that the autosegmentation algorithm is sufficiently accurate to provide organ dose estimates, since small errors delineating organ boundaries will have minimal effect when computing mean organ dose. A leave-one-out validation study of the automated algorithm was performed with 20 head-neck CT scans expertly segmented into nine regions. Mean organ doses of the automatically and expertly segmented regions were computed from Monte Carlo-generated dose maps and compared. The automated segmentation algorithm estimated the mean organ dose to be within 10% of the expert segmentation for regions other than the spinal canal, with the median error for each organ region below 2%. In the spinal canal region, the median error was −7%, with a maximum absolute error of 28% for the single-atlas approach and 11% for the multiatlas approach. The results demonstrate that the automated segmentation algorithm can provide accurate organ dose estimates despite some segmentation errors. PMID:27921070

Preliminary estimates of the direct costs associated with endemic diseases of livestock in Great Britain.

PubMed

Bennett, R; Christiansen, K; Clifton-Hadley, R

1999-04-09

Many 'economic' studies of livestock diseases in Great Britain have been carried out over time. Most studies have considered just one or two diseases and used a different methodology and valuation base from other studies, hampering any comparative assessment of the economic impact of diseases. A standardized methodology was applied to the estimation of the direct costs to livestock production of some 30 endemic diseases/conditions of farm animals in Great Britain. This involved identification of the livestock populations at risk, estimation of the annual incidence of each disease in these populations, identification of the range and incidence of physical effects of each disease on production, valuation of the physical effects of each disease and estimation of the financial value of output losses/resource wastage due to a disease and the costs of specific treatment and prevention measures. The wider economic impacts of disease (such as the implications for human health, animal welfare and markets) were not included in the assessments. Using this standardized methodology with common financial values, a simple spreadsheet model was constructed for each disease. Given the paucity of appropriate disease data for economic assessment, 'low' and 'high' values were used to reflect uncertainties surrounding key disease parameters. Preliminary estimates of the value of disease output losses/resource wastage, treatment and prevention costs are presented for each disease. Despite the limitations of the spreadsheet models and of the estimates derived from them, we conclude that the models represent a useful start in developing a system for the comparative economic assessment of livestock diseases in Great Britain.

Parenchymal Texture Analysis in Digital Breast Tomosynthesis for Breast Cancer Risk Estimation: A Preliminary Study

PubMed Central

Kontos, Despina; Bakic, Predrag R.; Carton, Ann-Katherine; Troxel, Andrea B.; Conant, Emily F.; Maidment, Andrew D.A.

2009-01-01

Rationale and Objectives Studies have demonstrated a relationship between mammographic parenchymal texture and breast cancer risk. Although promising, texture analysis in mammograms is limited by tissue superimposition. Digital breast tomosynthesis (DBT) is a novel tomographic x-ray breast imaging modality that alleviates the effect of tissue superimposition, offering superior parenchymal texture visualization compared to mammography. Our study investigates the potential advantages of DBT parenchymal texture analysis for breast cancer risk estimation. Materials and Methods DBT and digital mammography (DM) images of 39 women were analyzed. Texture features, shown in studies with mammograms to correlate with cancer risk, were computed from the retroareolar breast region. We compared the relative performance of DBT and DM texture features in correlating with two measures of breast cancer risk: (i) the Gail and Claus risk estimates, and (ii) mammographic breast density. Linear regression was performed to model the association between texture features and increasing levels of risk. Results No significant correlation was detected between parenchymal texture and the Gail and Claus risk estimates. Significant correlations were observed between texture features and breast density. Overall, the DBT texture features demonstrated stronger correlations with breast percent density (PD) than DM (p ≤0.05). When dividing our study population in groups of increasing breast PD, the DBT texture features appeared to be more discriminative, having regression lines with overall lower p-values, steeper slopes, and higher R2 estimates. Conclusion Although preliminary, our results suggest that DBT parenchymal texture analysis could provide more accurate characterization of breast density patterns, which could ultimately improve breast cancer risk estimation. PMID:19201357

The cost of child health inequalities in Aotearoa New Zealand: a preliminary scoping study.

PubMed

Mills, Clair; Reid, Papaarangi; Vaithianathan, Rhema

2012-05-28

Health inequalities have been extensively documented, internationally and in New Zealand. The cost of reducing health inequities is often perceived as high; however, recent international studies suggest the cost of "doing nothing" is itself significant. This study aimed to develop a preliminary estimate of the economic cost of health inequities between Māori (indigenous) and non-Māori children in New Zealand. Standard quantitative epidemiological methods and "cost of illness" methodology were employed, within a Kaupapa Māori theoretical framework. Data were obtained from national data collections held by the New Zealand Health Information Service and other health sector agencies. Preliminary estimates suggest child health inequities between Māori and non-Māori in New Zealand are cost-saving to the health sector. However the societal costs are significant. A conservative "base case" scenario estimate is over $NZ62 million per year, while alternative costing methods yield larger costs of nearly $NZ200 million per annum. The total cost estimate is highly sensitive to the costing method used and Value of Statistical Life applied, as the cost of potentially avoidable deaths of Māori children is the major contributor to this estimate. This preliminary study suggests that health sector spending is skewed towards non-Māori children despite evidence of greater Māori need. Persistent child health inequities result in significant societal economic costs. Eliminating child health inequities, particularly in primary care access, could result in significant economic benefits for New Zealand. However, there are conceptual, ethical and methodological challenges in estimating the economic cost of child health inequities. Re-thinking of traditional economic frameworks and development of more appropriate methodologies is required.

43 CFR 3425.1-7 - Preliminary data.

Code of Federal Regulations, 2013 CFR

2013-10-01

... used is other than underground mining techniques, the authorized officer shall obtain documents... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Preliminary data. 3425.1-7 Section 3425.1... Preliminary data. (a) Any application for a lease shall contain preliminary data to assist the authorized...

43 CFR 3425.1-7 - Preliminary data.

Code of Federal Regulations, 2012 CFR

2012-10-01

... used is other than underground mining techniques, the authorized officer shall obtain documents... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Preliminary data. 3425.1-7 Section 3425.1... Preliminary data. (a) Any application for a lease shall contain preliminary data to assist the authorized...

43 CFR 3425.1-7 - Preliminary data.

Code of Federal Regulations, 2014 CFR

2014-10-01

... used is other than underground mining techniques, the authorized officer shall obtain documents... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Preliminary data. 3425.1-7 Section 3425.1... Preliminary data. (a) Any application for a lease shall contain preliminary data to assist the authorized...

Precise attitude rate estimation using star images obtained by mission telescope for satellite missions

NASA Astrophysics Data System (ADS)

Inamori, Takaya; Hosonuma, Takayuki; Ikari, Satoshi; Saisutjarit, Phongsatorn; Sako, Nobutada; Nakasuka, Shinichi

2015-02-01

Recently, small satellites have been employed in various satellite missions such as astronomical observation and remote sensing. During these missions, the attitudes of small satellites should be stabilized to a higher accuracy to obtain accurate science data and images. To achieve precise attitude stabilization, these small satellites should estimate their attitude rate under the strict constraints of mass, space, and cost. This research presents a new method for small satellites to precisely estimate angular rate using star blurred images by employing a mission telescope to achieve precise attitude stabilization. In this method, the angular velocity is estimated by assessing the quality of a star image, based on how blurred it appears to be. Because the proposed method utilizes existing mission devices, a satellite does not require additional precise rate sensors, which makes it easier to achieve precise stabilization given the strict constraints possessed by small satellites. The research studied the relationship between estimation accuracy and parameters used to achieve an attitude rate estimation, which has a precision greater than 1 × 10-6 rad/s. The method can be applied to all attitude sensors, which use optics systems such as sun sensors and star trackers (STTs). Finally, the method is applied to the nano astrometry satellite Nano-JASMINE, and we investigate the problems that are expected to arise with real small satellites by performing numerical simulations.

Effect of windowing on lithosphere elastic thickness estimates obtained via the coherence method: Results from northern South America

NASA Astrophysics Data System (ADS)

Ojeda, GermáN. Y.; Whitman, Dean

2002-11-01

The effective elastic thickness (Te) of the lithosphere is a parameter that describes the flexural strength of a plate. A method routinely used to quantify this parameter is to calculate the coherence between the two-dimensional gravity and topography spectra. Prior to spectra calculation, data grids must be "windowed" in order to avoid edge effects. We investigated the sensitivity of Te estimates obtained via the coherence method to mirroring, Hanning and multitaper windowing techniques on synthetic data as well as on data from northern South America. These analyses suggest that the choice of windowing technique plays an important role in Te estimates and may result in discrepancies of several kilometers depending on the selected windowing method. Te results from mirrored grids tend to be greater than those from Hanning smoothed or multitapered grids. Results obtained from mirrored grids are likely to be over-estimates. This effect may be due to artificial long wavelengths introduced into the data at the time of mirroring. Coherence estimates obtained from three subareas in northern South America indicate that the average effective elastic thickness is in the range of 29-30 km, according to Hanning and multitaper windowed data. Lateral variations across the study area could not be unequivocally determined from this study. We suggest that the resolution of the coherence method does not permit evaluation of small (i.e., ˜5 km), local Te variations. However, the efficiency and robustness of the coherence method in rendering continent-scale estimates of elastic thickness has been confirmed.

An Automated Technique for Estimating Daily Precipitation over the State of Virginia

NASA Technical Reports Server (NTRS)

Follansbee, W. A.; Chamberlain, L. W., III

1981-01-01

Digital IR and visible imagery obtained from a geostationary satellite located over the equator at 75 deg west latitude were provided by NASA and used to obtain a linear relationship between cloud top temperature and hourly precipitation. Two computer programs written in FORTRAN were used. The first program computes the satellite estimate field from the hourly digital IR imagery. The second program computes the final estimate for the entire state area by comparing five preliminary estimates of 24 hour precipitation with control raingage readings and determining which of the five methods gives the best estimate for the day. The final estimate is then produced by incorporating control gage readings into the winning method. In presenting reliable precipitation estimates for every cell in Virginia in near real time on a daily on going basis, the techniques require on the order of 125 to 150 daily gage readings by dependable, highly motivated observers distributed as uniformly as feasible across the state.

The cost of child health inequalities in Aotearoa New Zealand: a preliminary scoping study

PubMed Central

2012-01-01

Background Health inequalities have been extensively documented, internationally and in New Zealand. The cost of reducing health inequities is often perceived as high; however, recent international studies suggest the cost of “doing nothing” is itself significant. This study aimed to develop a preliminary estimate of the economic cost of health inequities between Māori (indigenous) and non-Māori children in New Zealand. Methods Standard quantitative epidemiological methods and “cost of illness” methodology were employed, within a Kaupapa Māori theoretical framework. Data were obtained from national data collections held by the New Zealand Health Information Service and other health sector agencies. Results Preliminary estimates suggest child health inequities between Māori and non-Māori in New Zealand are cost-saving to the health sector. However the societal costs are significant. A conservative “base case” scenario estimate is over $NZ62 million per year, while alternative costing methods yield larger costs of nearly $NZ200 million per annum. The total cost estimate is highly sensitive to the costing method used and Value of Statistical Life applied, as the cost of potentially avoidable deaths of Māori children is the major contributor to this estimate. Conclusions This preliminary study suggests that health sector spending is skewed towards non-Māori children despite evidence of greater Māori need. Persistent child health inequities result in significant societal economic costs. Eliminating child health inequities, particularly in primary care access, could result in significant economic benefits for New Zealand. However, there are conceptual, ethical and methodological challenges in estimating the economic cost of child health inequities. Re-thinking of traditional economic frameworks and development of more appropriate methodologies is required. PMID:22640030

Accuracy of patient specific organ-dose estimates obtained using an automated image segmentation algorithm

NASA Astrophysics Data System (ADS)

Gilat-Schmidt, Taly; Wang, Adam; Coradi, Thomas; Haas, Benjamin; Star-Lack, Josh

2016-03-01

The overall goal of this work is to develop a rapid, accurate and fully automated software tool to estimate patient-specific organ doses from computed tomography (CT) scans using a deterministic Boltzmann Transport Equation solver and automated CT segmentation algorithms. This work quantified the accuracy of organ dose estimates obtained by an automated segmentation algorithm. The investigated algorithm uses a combination of feature-based and atlas-based methods. A multiatlas approach was also investigated. We hypothesize that the auto-segmentation algorithm is sufficiently accurate to provide organ dose estimates since random errors at the organ boundaries will average out when computing the total organ dose. To test this hypothesis, twenty head-neck CT scans were expertly segmented into nine regions. A leave-one-out validation study was performed, where every case was automatically segmented with each of the remaining cases used as the expert atlas, resulting in nineteen automated segmentations for each of the twenty datasets. The segmented regions were applied to gold-standard Monte Carlo dose maps to estimate mean and peak organ doses. The results demonstrated that the fully automated segmentation algorithm estimated the mean organ dose to within 10% of the expert segmentation for regions other than the spinal canal, with median error for each organ region below 2%. In the spinal canal region, the median error was 7% across all data sets and atlases, with a maximum error of 20%. The error in peak organ dose was below 10% for all regions, with a median error below 4% for all organ regions. The multiple-case atlas reduced the variation in the dose estimates and additional improvements may be possible with more robust multi-atlas approaches. Overall, the results support potential feasibility of an automated segmentation algorithm to provide accurate organ dose estimates.

Satellite servicing mission preliminary cost estimation model

NASA Technical Reports Server (NTRS)

1987-01-01

The cost model presented is a preliminary methodology for determining a rough order-of-magnitude cost for implementing a satellite servicing mission. Mission implementation, in this context, encompassess all activities associated with mission design and planning, including both flight and ground crew training and systems integration (payload processing) of servicing hardward with the Shuttle. A basic assumption made in developing this cost model is that a generic set of servicing hardware was developed and flight tested, is inventoried, and is maintained by NASA. This implies that all hardware physical and functional interfaces are well known and therefore recurring CITE testing is not required. The development of the cost model algorithms and examples of their use are discussed.

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions, Addendum

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1975-01-01

New results and insights concerning a previously published iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions were discussed. It was shown that the procedure converges locally to the consistent maximum likelihood estimate as long as a specified parameter is bounded between two limits. Bound values were given to yield optimal local convergence.

Estimating the effect of hospital closure on areawide inpatient hospital costs: a preliminary model and application.

PubMed Central

Shepard, D S

1983-01-01

A preliminary model is developed for estimating the extent of savings, if any, likely to result from discontinuing a specific inpatient service. By examining the sources of referral to the discontinued service, the model estimates potential demand and how cases will be redistributed among remaining hospitals. This redistribution determines average cost per day in hospitals that receive these cases, relative to average cost per day of the discontinued service. The outflow rate, which measures the proportion of cases not absorbed in other acute care hospitals, is estimated as 30 percent for the average discontinuation. The marginal cost ratio, which relates marginal costs of cases absorbed in surrounding hospitals to the average costs in those hospitals, is estimated as 87 percent in the base case. The model was applied to the discontinuation of all inpatient services in the 75-bed Chelsea Memorial Hospital, near Boston, Massachusetts, using 1976 data. As the precise value of key parameters is uncertain, sensitivity analysis was used to explore a range of values. The most likely result is a small increase ($120,000) in the area's annual inpatient hospital costs, because many patients are referred to more costly teaching hospitals. A similar situation may arise with other urban closures. For service discontinuations to generate savings, recipient hospitals must be low in costs, the outflow rate must be large, and the marginal cost ratio must be low. PMID:6668181

A preliminary estimate of the EUVE cumulative distribution of exposure time on the unit sphere. [Extreme Ultra-Violet Explorer

NASA Technical Reports Server (NTRS)

Tang, C. C. H.

1984-01-01

A preliminary study of an all-sky coverage of the EUVE mission is given. Algorithms are provided to compute the exposure of the celestial sphere under the spinning telescopes, taking into account that during part of the exposure time the telescopes are blocked by the earth. The algorithms are used to give an estimate of exposure time at different ecliptic latitudes as a function of the angle of field of view of the telescope. Sample coverage patterns are also given for a 6-month mission.

Challenges in Obtaining Estimates of the Risk of Tuberculosis Infection During Overseas Deployment.

PubMed

Mancuso, James D; Geurts, Mia

2015-12-01

Estimates of the risk of tuberculosis (TB) infection resulting from overseas deployment among U.S. military service members have varied widely, and have been plagued by methodological problems. The purpose of this study was to estimate the incidence of TB infection in the U.S. military resulting from deployment. Three populations were examined: 1) a unit of 2,228 soldiers redeploying from Iraq in 2008, 2) a cohort of 1,978 soldiers followed up over 5 years after basic training at Fort Jackson in 2009, and 3) 6,062 participants in the 2011-2012 National Health and Nutrition Examination Survey (NHANES). The risk of TB infection in the deployed population was low-0.6% (95% confidence interval [CI]: 0.1-2.3%)-and was similar to the non-deployed population. The prevalence of latent TB infection (LTBI) in the U.S. population was not significantly different among deployed and non-deployed veterans and those with no military service. The limitations of these retrospective studies highlight the challenge in obtaining valid estimates of risk using retrospective data and the need for a more definitive study. Similar to civilian long-term travelers, risks for TB infection during deployment are focal in nature, and testing should be targeted to only those at increased risk. © The American Society of Tropical Medicine and Hygiene.

Conceptual Cost Estimating

NASA Technical Reports Server (NTRS)

Brown, J. A.

1983-01-01

Kennedy Space Center data aid in efficient construction-cost managment. Report discusses development and use of NASA TR-1508, Kennedy Space Center Aerospace Construction price book for preparing conceptual budget, funding cost estimating, and preliminary cost engineering reports. Report based on actual bid prices and Government estimates.

Preliminary Estimation of Deoxynivalenol Excretion through a 24 h Pilot Study

PubMed Central

Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Font, Guillermina

2015-01-01

A duplicate diet study was designed to explore the occurrence of 15 Fusarium mycotoxins in the 24 h-diet consumed by one volunteer as well as the levels of mycotoxins in his 24 h-collected urine. The employed methodology involved solvent extraction at high ionic strength followed by dispersive solid phase extraction and gas chromatography determination coupled to mass spectrometry in tandem. Satisfactory results in method performance were achieved. The method’s accuracy was in a range of 68%–108%, with intra-day relative standard deviation and inter-day relative standard deviation lower than 12% and 15%, respectively. The limits of quantitation ranged from 0.1 to 8 µg/Kg. The matrix effect was evaluated and matrix-matched calibrations were used for quantitation. Only deoxynivalenol (DON) was quantified in both food and urine samples. A total DON daily intake amounted to 49.2 ± 5.6 µg whereas DON daily excretion of 35.2 ± 4.3 µg was determined. DON daily intake represented 68.3% of the established DON provisional maximum tolerable daily intake (PMTDI). Valuable preliminary information was obtained as regards DON excretion and needs to be confirmed in large-scale monitoring studies. PMID:25723325

1996 Traffic Crashes, Injuries, and Fatalities: Preliminary Report

DOT National Transportation Integrated Search

1997-03-01

This report contains preliminary estimates of the number of police reported : crashes, injuries, and fatalities for 1996. Trend data are presented using : these estimates. The trend for the fatality rate per 100 million vehicle miles : of travel is a...

The first step toward genetic selection for host tolerance to infectious pathogens: obtaining the tolerance phenotype through group estimates

PubMed Central

Doeschl-Wilson, Andrea B.; Villanueva, Beatriz; Kyriazakis, Ilias

2012-01-01

Reliable phenotypes are paramount for meaningful quantification of genetic variation and for estimating individual breeding values on which genetic selection is based. In this paper, we assert that genetic improvement of host tolerance to disease, although desirable, may be first of all handicapped by the ability to obtain unbiased tolerance estimates at a phenotypic level. In contrast to resistance, which can be inferred by appropriate measures of within host pathogen burden, tolerance is more difficult to quantify as it refers to change in performance with respect to changes in pathogen burden. For this reason, tolerance phenotypes have only been specified at the level of a group of individuals, where such phenotypes can be estimated using regression analysis. However, few stsudies have raised the potential bias in these estimates resulting from confounding effects between resistance and tolerance. Using a simulation approach, we demonstrate (i) how these group tolerance estimates depend on within group variation and co-variation in resistance, tolerance, and vigor (performance in a pathogen free environment); and (ii) how tolerance estimates are affected by changes in pathogen virulence over the time course of infection and by the timing of measurements. We found that in order to obtain reliable group tolerance estimates, it is important to account for individual variation in vigor, if present, and that all individuals are at the same stage of infection when measurements are taken. The latter requirement makes estimation of tolerance based on cross-sectional field data challenging, as individuals become infected at different time points and the individual onset of infection is unknown. Repeated individual measurements of within host pathogen burden and performance would not only be valuable for inferring the infection status of individuals in field conditions, but would also provide tolerance estimates that capture the entire time course of infection. PMID

Estimation of nitrate and nitrogen forms of vegetables by UV-spectrophotometry after photo-oxydation.

PubMed

Ribeiro, T; Depres, S; Couteau, G; Pauss, A

2003-01-01

An alternative method for the estimation of nitrate and nitrogen forms in vegetables is proposed. Nitrate can be directly estimated by UV-spectrophotometry after an extraction step with water. The other nitrogen compounds are photo-oxidized into nitrate, and then estimated by UV-spectrophotometry. An oxidative solution of sodium persulfate and a Hg-UV lamp is used. Preliminary assays were realized with vegetables like salade, spinachs, artichokes, small peas, broccolis, carrots, watercress; acceptable correlations between expected and experimental values of nitrate amounts were obtained, while the detection limit needs to be lowered. The optimization of the method is underway.

1986 traffic fatalities, preliminary report

DOT National Transportation Integrated Search

1987-04-01

This report provides a number of preliminary estimate of traffic fatalities and fatal accidents for 1986. Trend data are presented for both the long and short term. Some summary statistics are provided at the State and Regional level. The national es...

Energy and raw material potentials of wood residue in the Pacific Coast States: a summary of a preliminary feasibility investigation.

Treesearch

John B. Grantham; Eldon Estep; John M. Pierovich; Harold Tarkow; Thomas C. Adams

1974-01-01

Results are reported of a preliminary investigation of feasibility of using wood residue to meet energy and raw material needs in the Pacific Coast States. Magnitude of needs was examined and volume of logging-residue and unused mill residue was estimated. Costs of obtaining and preprocessing logging residue for energy and pulp and particle board raw material were...

Regression model estimation of early season crop proportions: North Dakota, some preliminary results

NASA Technical Reports Server (NTRS)

Lin, K. K. (Principal Investigator)

1982-01-01

To estimate crop proportions early in the season, an approach is proposed based on: use of a regression-based prediction equation to obtain an a priori estimate for specific major crop groups; modification of this estimate using current-year LANDSAT and weather data; and a breakdown of the major crop groups into specific crops by regression models. Results from the development and evaluation of appropriate regression models for the first portion of the proposed approach are presented. The results show that the model predicts 1980 crop proportions very well at both county and crop reporting district levels. In terms of planted acreage, the model underpredicted 9.1 percent of the 1980 published data on planted acreage at the county level. It predicted almost exactly the 1980 published data on planted acreage at the crop reporting district level and overpredicted the planted acreage by just 0.92 percent.

Architects and Design-Phase Cost Estimates: Design Professionals Should Reconsider the Value of Third-Party Estimates

ERIC Educational Resources Information Center

Coakley, John

2010-01-01

Professional cost estimators are widely used by architects during the design phases of a project to provide preliminary cost estimates. These estimates may begin at the conceptual design phase and are prepared at regular intervals through the construction document phase. Estimating professionals are frequently tasked with "selling" the importance…

Estimates of amounts of soil removal for clean-up of transuranics at NAEG offsite safety-shot sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinnison, R.R.; Gilbert, R.O.

Rough estimates are given for the amount of soil removal necessary to decontaminate five representative safety-shot areas. In order to decontaminate to levels of less than 160 pCi /sup 239/Pu per gram of surface soil, it is estimated that over one-half million tons of soil would have to be removed from the five areas. This is a preliminary estimate based on summary data and concentration contour maps readily available in NAEG publications. More accurate estimates could be obtained by applying Kriging techniques to available soil data if the need arises. The inclusion of /sup 241/Am and /sup 238/Pu activities domore » not significantly increase the soil tonnage estimates obtained for /sup 239/ /sup 240/Pu because of their relatively small contributions to total transuranic activity. The magnitude of the errors inherent in our use of summary data to obtain rough estimates also suggests that a revision of the tonnage estimates for /sup 239/ /sup 240/Pu to include /sup 241/Am and /sup 238/Pu is not warranted.« less

An Optimal Estimation Method to Obtain Surface Layer Turbulent Fluxes from Profile Measurements

NASA Astrophysics Data System (ADS)

Kang, D.

2015-12-01

In the absence of direct turbulence measurements, the turbulence characteristics of the atmospheric surface layer are often derived from measurements of the surface layer mean properties based on Monin-Obukhov Similarity Theory (MOST). This approach requires two levels of the ensemble mean wind, temperature, and water vapor, from which the fluxes of momentum, sensible heat, and water vapor can be obtained. When only one measurement level is available, the roughness heights and the assumed properties of the corresponding variables at the respective roughness heights are used. In practice, the temporal mean with large number of samples are used in place of the ensemble mean. However, in many situations the samples of data are taken from multiple levels. It is thus desirable to derive the boundary layer flux properties using all measurements. In this study, we used an optimal estimation approach to derive surface layer properties based on all available measurements. This approach assumes that the samples are taken from a population whose ensemble mean profile follows the MOST. An optimized estimate is obtained when the results yield a minimum cost function defined as a weighted summation of all error variance at each sample altitude. The weights are based one sample data variance and the altitude of the measurements. This method was applied to measurements in the marine atmospheric surface layer from a small boat using radiosonde on a tethered balloon where temperature and relative humidity profiles in the lowest 50 m were made repeatedly in about 30 minutes. We will present the resultant fluxes and the derived MOST mean profiles using different sets of measurements. The advantage of this method over the 'traditional' methods will be illustrated. Some limitations of this optimization method will also be discussed. Its application to quantify the effects of marine surface layer environment on radar and communication signal propagation will be shown as well.

A preliminary assessment of GPM-based multi-satellite precipitation estimates over a monsoon dominated region

NASA Astrophysics Data System (ADS)

Prakash, Satya; Mitra, Ashis K.; AghaKouchak, Amir; Liu, Zhong; Norouzi, Hamidreza; Pai, D. S.

2018-01-01

Following the launch of the Global Precipitation Measurement (GPM) Core Observatory, two advanced high resolution multi-satellite precipitation products namely, Integrated Multi-satellitE Retrievals for GPM (IMERG) and Global Satellite Mapping of Precipitation (GSMaP) version 6 are released. A critical evaluation of these newly released precipitation data sets is very important for both the end users and data developers. This study provides a comprehensive assessment of IMERG research product and GSMaP estimates over India at a daily scale for the southwest monsoon season (June to September 2014). The GPM-based precipitation products are inter-compared with widely used TRMM Multi-satellite Precipitation Analysis (TMPA), and gauge-based observations over India. Results show that the IMERG estimates represent the mean monsoon rainfall and its variability more realistically than the gauge-adjusted TMPA and GSMaP data. However, GSMaP has relatively smaller root-mean-square error than IMERG and TMPA, especially over the low mean rainfall regimes and along the west coast of India. An entropy-based approach is employed to evaluate the distributions of the selected precipitation products. The results indicate that the distribution of precipitation in IMERG and GSMaP has been improved markedly, especially for low precipitation rates. IMERG shows a clear improvement in missed and false precipitation bias over India. However, all the three satellite-based rainfall estimates show exceptionally smaller correlation coefficient, larger RMSE, larger negative total bias and hit bias over the northeast India where precipitation is dominated by orographic effects. Similarly, the three satellite-based estimates show larger false precipitation over the southeast peninsular India which is a rain-shadow region. The categorical verification confirms that these satellite-based rainfall estimates have difficulties in detection of rain over the southeast peninsula and northeast India. These

Estimates of the solar internal angular velocity obtained with the Mt. Wilson 60-foot solar tower

NASA Technical Reports Server (NTRS)

Rhodes, Edward J., Jr.; Cacciani, Alessandro; Woodard, Martin; Tomczyk, Steven; Korzennik, Sylvain

1987-01-01

Estimates are obtained of the solar internal angular velocity from measurements of the frequency splittings of p-mode oscillations. A 16-day time series of full-disk Dopplergrams obtained during July and August 1984 at the 60-foot tower telescope of the Mt. Wilson Observatory is analyzed. Power spectra were computed for all of the zonal, tesseral, and sectoral p-modes from l = 0 to 89 and for all of the sectoral p-modes from l = 90 to 200. A mean power spectrum was calculated for each degree up to 89. The frequency differences of all of the different nonzonal modes were calculated for these mean power spectra.

Estimation of Ice Surface Scattering and Acoustic Attenuation in Arctic Sediments from Long-Range Propagation Data

DTIC Science & Technology

1984-01-01

frequencies over the calculation at 1 meter. This was corrected by +60 dB to obtain the signature at I meter, and then by -160 dB to obtain the voltage...FFT with appropriate corrections for one-sided energy spectral density re . 1 V2/Hz. The spectrum was then smeared over a 4 Hz band by a running...after correcting the array estimated slownesses for slight bathymetric dip local to the receiving array. A preliminary inversion of this type is given by

Preliminary risk assessment for nuclear waste disposal in space, volume 1

NASA Technical Reports Server (NTRS)

Rice, E. E.; Denning, R. S.; Friedlander, A. L.

1982-01-01

The feasibility, desirability and preferred approaches for disposal of selected high-level nuclear wastes in space were analyzed. Preliminary space disposal risk estimates and estimates of risk uncertainty are provided.

Comparison of internal dose estimates obtained using organ-level, voxel S value, and Monte Carlo techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grimes, Joshua, E-mail: grimes.joshua@mayo.edu; Celler, Anna

2014-09-15

Purpose: The authors’ objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient-specific anatomy on the final dose estimate. Methods: Six patients injected with{sup 99m}Tc-hydrazinonicotinamide-Tyr{sup 3}-octreotide were included in this study. A hybrid planar/SPECT imaging protocol was used to estimate {sup 99m}Tc time-integrated activity coefficients (TIACs) for kidneys, liver, spleen, and tumors. Additionally, TIACs were predicted for {sup 131}I, {sup 177}Lu, and {sup 90}Y assuming themore » same biological half-lives as the {sup 99m}Tc labeled tracer. The TIACs were used as input for OLINDA/EXM for organ-level dose calculation and voxel level dosimetry was performed using the voxel S value method and Monte Carlo simulation. Dose estimates for {sup 99m}Tc, {sup 131}I, {sup 177}Lu, and {sup 90}Y distributions were evaluated by comparing (i) organ-level S values corresponding to each method, (ii) total tumor and organ doses, (iii) differences in right and left kidney doses, and (iv) voxelized dose distributions calculated by Monte Carlo and the voxel S value technique. Results: The S values for all investigated radionuclides used by OLINDA/EXM and the corresponding patient-specific S values calculated by Monte Carlo agreed within 2.3% on average for self-irradiation, and differed by as much as 105% for cross-organ irradiation. Total organ doses calculated by OLINDA/EXM and the voxel S value technique agreed with Monte Carlo results within approximately ±7%. Differences between right and left kidney doses determined by Monte Carlo were as high as 73%. Comparison of the Monte Carlo and voxel S value dose distributions showed that each method produced similar dose volume histograms with a minimum dose covering 90% of the volume

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1978-01-01

This paper addresses the problem of obtaining numerically maximum-likelihood estimates of the parameters for a mixture of normal distributions. In recent literature, a certain successive-approximations procedure, based on the likelihood equations, was shown empirically to be effective in numerically approximating such maximum-likelihood estimates; however, the reliability of this procedure was not established theoretically. Here, we introduce a general iterative procedure, of the generalized steepest-ascent (deflected-gradient) type, which is just the procedure known in the literature when the step-size is taken to be 1. We show that, with probability 1 as the sample size grows large, this procedure converges locally to the strongly consistent maximum-likelihood estimate whenever the step-size lies between 0 and 2. We also show that the step-size which yields optimal local convergence rates for large samples is determined in a sense by the 'separation' of the component normal densities and is bounded below by a number between 1 and 2.

Preliminary validation of leaf area index sensor in Huailai

NASA Astrophysics Data System (ADS)

Cai, Erli; Li, Xiuhong; Liu, Qiang; Dou, Baocheng; Chang, Chongyan; Niu, Hailin; Lin, Xingwen; Zhang, Jialin

2015-12-01

Leaf area index (LAI) is a key variable in many land surface models that involve energy and mass exchange between vegetation and the environment. In recent years, extracting vegetation structure parameters from digital photography becomes a widely used indirect method to estimate LAI for its simplicity and ease of use. A Leaf Area Index Sensor (LAIS) system was developed to continuously monitor the growth of crops in several sampling points in Huailai, China. The system applies 3G/WIFI communication technology to remotely collect crop photos in real-time. Then the crop photos are automatically processed and LAI is estimated based on the improved leaf area index of Lang and Xiang (LAILX) algorithm in LAIS. The objective of this study is to primarily verify the LAI estimated from LAIS (Lphoto) through comparing them with the destructive green LAI (Ldest). Ldest was measured across the growing season ntil maximum canopy development while plants are still green. The preliminary verification shows that Lphoto corresponds well with the Ldest (R2=0.975). In general, LAI could be accurately estimated with LAIS and its LAI shows high consistency compared with the destructive green LAI. The continuous LAI measurement obtained from LAIS could be used for the validation of remote sensing LAI products.

Preliminary Results from Powell Research Group on Integrating GRACE Satellite and Ground-based Estimates of Groundwater Storage Changes

NASA Astrophysics Data System (ADS)

Scanlon, B. R.; Zhang, Z.; Reitz, M.; Rodell, M.; Sanford, W. E.; Save, H.; Wiese, D. N.; Croteau, M. J.; McGuire, V. L.; Pool, D. R.; Faunt, C. C.; Zell, W.

2017-12-01

Groundwater storage depletion is a critical issue for many of the major aquifers in the U.S., particularly during intense droughts. GRACE (Gravity Recovery and Climate Experiment) satellite-based estimates of groundwater storage changes have attracted considerable media attention in the U.S. and globally and interest in GRACE products continues to increase. For this reason, a Powell Research Group was formed to: (1) Assess variations in groundwater storage using a variety of GRACE products and other storage components (snow, surface water, and soil moisture) for major aquifers in the U.S., (2) Quantify long-term trends in groundwater storage from ground-based monitoring and regional and national modeling, and (3) Use ground-based monitoring and modeling to interpret GRACE water storage changes within the context of extreme droughts and over-exploitation of groundwater. The group now has preliminary estimates from long-term trends and seasonal fluctuations in water storage using different GRACE solutions, including CSR, JPL and GSFC. Approaches to quantifying uncertainties in GRACE data are included. This work also shows how GRACE sees groundwater depletion in unconfined versus confined aquifers, and plans for future work will link GRACE data to regional groundwater models. The wealth of ground-based observations for the U.S. provides a unique opportunity to assess the reliability of GRACE-based estimates of groundwater storage changes.

Preliminary Analysis of a Submerged Wave Energy Device

NASA Astrophysics Data System (ADS)

Wagner, J. R.; Wagner, J. J.; Hayatdavoodi, M.; Ertekin, R. C.

2016-02-01

Preliminary analysis of a submerged wave energy harvesting device is presented. The device is composed of a thin, horizontally submerged plate that is restricted to heave oscillations under the influence of surface waves. The submerged plate is oscillating, and it can be attached to a fixed rotor, or a piston, to harvest the wave energy. A fully submerged wave energy converter is preferred over a surface energy convertor due to its durability and less visual and physical distractions it presents. In this study, the device is subject to nonlinear shallow-water waves. Wave loads on the submerged oscillating plate are obtained via the Level I Green-Naghdi equations. The unsteady motion of the plate is obtained by solving the nonlinear equations of motion. The results are obtained for a range of waves with varying heights and periods. The amplitude and period of plate oscillations are analyzed as functions of the wave parameters and plate width. Particular attention is given to the selection of the site of desired wave field. Initial estimation on the amount of energy extraction from the device, located near shore at a given site, is provided.

Space Shuttle propulsion parameter estimation using optimal estimation techniques

NASA Technical Reports Server (NTRS)

1983-01-01

The fifth monthly progress report includes corrections and additions to the previously submitted reports. The addition of the SRB propellant thickness as a state variable is included with the associated partial derivatives. During this reporting period, preliminary results of the estimation program checkout was presented to NASA technical personnel.

Estimating Bottleneck Bandwidth using TCP

NASA Technical Reports Server (NTRS)

Allman, Mark

1998-01-01

Various issues associated with estimating bottleneck bandwidth using TCP are presented in viewgraph form. Specific topics include: 1) Why TCP is wanted to estimate the bottleneck bandwidth; 2) Setting ssthresh to an appropriate value to reduce loss; 3) Possible packet-pair solutions; and 4) Preliminary results: ACTS and the Internet.

Separating Autotrophic and Heterotrophic Respiration in Streams and the Importance for Carbon Cycling: a Preliminary Study

NASA Astrophysics Data System (ADS)

Bozeman, M.; Raymond, P.

2005-05-01

Autotrophic and heterotrophic organisms confer different effects on nutrient cycling, especially on carbon (C). In stream ecosystems, net ecosystem production determines the amount and form of C exported; however any transformation due to different respiratory (R) mechanisms are not separated. These mechanisms highly influence the form and lability of the C transported. To understand the current state of knowledge and estimate the importance of autotrophic versus heterotrophic R, we obtained a range of respiratory rates from the literature and modeled effects of different balances of rates on bulk dissolved inorganic and organic C chemistry. Preliminary results show that a wide range of estimates of autotrophic R exist and that these can effect bulk properties of exported C. While specific effects are highly dependent upon physical structure of the study watershed, we offer that separating R mechanisms provides further insight into ecosystem C cycling. We also propose a method to measure autotrophic and heterotrophic R at the ecosystem scale and obtain watershed-level estimates of the importance of these processes on C cycling.

LC-MS/MS-based approach for obtaining exposure estimates of metabolites in early clinical trials using radioactive metabolites as reference standards.

PubMed

Zhang, Donglu; Raghavan, Nirmala; Chando, Theodore; Gambardella, Janice; Fu, Yunlin; Zhang, Duxi; Unger, Steve E; Humphreys, W Griffith

2007-12-01

An LC-MS/MS-based approach that employs authentic radioactive metabolites as reference standards was developed to estimate metabolite exposures in early drug development studies. This method is useful to estimate metabolite levels in studies done with non-radiolabeled compounds where metabolite standards are not available to allow standard LC-MS/MS assay development. A metabolite mixture obtained from an in vivo source treated with a radiolabeled compound was partially purified, quantified, and spiked into human plasma to provide metabolite standard curves. Metabolites were analyzed by LC-MS/MS using the specific mass transitions and an internal standard. The metabolite concentrations determined by this approach were found to be comparable to those determined by valid LC-MS/MS assays. This approach does not requires synthesis of authentic metabolites or the knowledge of exact structures of metabolites, and therefore should provide a useful method to obtain early estimates of circulating metabolites in early clinical or toxicological studies.

A time-frequency analysis method to obtain stable estimates of magnetotelluric response function based on Hilbert-Huang transform

NASA Astrophysics Data System (ADS)

Cai, Jianhua

2017-05-01

The time-frequency analysis method represents signal as a function of time and frequency, and it is considered a powerful tool for handling arbitrary non-stationary time series by using instantaneous frequency and instantaneous amplitude. It also provides a possible alternative to the analysis of the non-stationary magnetotelluric (MT) signal. Based on the Hilbert-Huang transform (HHT), a time-frequency analysis method is proposed to obtain stable estimates of the magnetotelluric response function. In contrast to conventional methods, the response function estimation is performed in the time-frequency domain using instantaneous spectra rather than in the frequency domain, which allows for imaging the response parameter content as a function of time and frequency. The theory of the method is presented and the mathematical model and calculation procedure, which are used to estimate response function based on HHT time-frequency spectrum, are discussed. To evaluate the results, response function estimates are compared with estimates from a standard MT data processing method based on the Fourier transform. All results show that apparent resistivities and phases, which are calculated from the HHT time-frequency method, are generally more stable and reliable than those determined from the simple Fourier analysis. The proposed method overcomes the drawbacks of the traditional Fourier methods, and the resulting parameter minimises the estimation bias caused by the non-stationary characteristics of the MT data.

Obtaining Parts

Science.gov Websites

The Cosmic Connection Parts for the Berkeley Detector Suppliers: Scintillator Eljen Technology 1 obtain the components needed to build the Berkeley Detector. These companies have helped previous the last update. He estimates that the cost to build a detector varies from $1500 to $2700 depending

Title I preliminary engineering for: A. S. E. F. solid waste to methane gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1976-01-01

An assignment to provide preliminary engineering of an Advanced System Experimental Facility for production of methane gas from urban solid waste by anaerobic digestion is documented. The experimental facility will be constructed on a now-existing solid waste shredding and landfill facility in Pompano Beach, Florida. Information is included on: general description of the project; justification of basic need; process design; preliminary drawings; outline specifications; preliminary estimate of cost; and time schedules for design and construction of accomplishment of design and construction. The preliminary cost estimate for the design and construction phases of the experimental program is $2,960,000, based on Dec.more » 1975 and Jan. 1976 costs. A time schedule of eight months to complete the Detailed Design, Equipment Procurement and the Award of Subcontracts is given.« less

Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach

NASA Astrophysics Data System (ADS)

Fienen, M.; Hunt, R.; Krabbenhoft, D.; Clemo, T.

2009-08-01

Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to estimate a unified set of hydrogeologic parameters using the Bayesian geostatistical inverse approach. Parameter flexibility is allowed by using a highly parameterized approach with the level of complexity informed by the data. Despite the effort to adhere to the ideal of minimal a priori structure imposed on the problem, extreme contrasts in parameters can result in the need to censor correlation across hydrostratigraphic bounding surfaces. These partitions segregate parameters into facies associations. With an iterative approach in which partitions are based on inspection of initial estimates, flow path interpretation is progressively refined through the inclusion of more types of data. Head observations, stable oxygen isotopes (18O/16O ratios), and tritium are all used to progressively refine flow path delineation on an isthmus between two lakes in the Trout Lake watershed, northern Wisconsin, United States. Despite allowing significant parameter freedom by estimating many distributed parameter values, a smooth field is obtained.

Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach

USGS Publications Warehouse

Fienen, M.; Hunt, R.; Krabbenhoft, D.; Clemo, T.

2009-01-01

Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to estimate a unified set of hydrogeologic parameters using the Bayesian geostatistical inverse approach. Parameter flexibility is allowed by using a highly parameterized approach with the level of complexity informed by the data. Despite the effort to adhere to the ideal of minimal a priori structure imposed on the problem, extreme contrasts in parameters can result in the need to censor correlation across hydrostratigraphic bounding surfaces. These partitions segregate parameters into facies associations. With an iterative approach in which partitions are based on inspection of initial estimates, flow path interpretation is progressively refined through the inclusion of more types of data. Head observations, stable oxygen isotopes (18O/16O ratios), and tritium are all used to progressively refine flow path delineation on an isthmus between two lakes in the Trout Lake watershed, northern Wisconsin, United States. Despite allowing significant parameter freedom by estimating many distributed parameter values, a smooth field is obtained.

SU-E-T-86: A Systematic Method for GammaKnife SRS Fetal Dose Estimation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geneser, S; Paulsson, A; Sneed, P

Purpose: Estimating fetal dose is critical to the decision-making process when radiation treatment is indicated during pregnancy. Fetal doses less than 5cGy confer no measurable non-cancer developmental risks but can produce a threefold increase in developing childhood cancer. In this study, we estimate fetal dose for a patient receiving Gamma Knife stereotactic radiosurgery (GKSRS) treatment and develop a method to estimate dose directly from plan details. Methods: A patient underwent GKSRS on a Perfexion unit for eight brain metastases (two infratentorial and one brainstem). Dose measurements were performed using a CC13, head phantom, and solid water. Superficial doses to themore » thyroid, sternum, and pelvis were measured using MOSFETs during treatment. Because the fetal dose was too low to accurately measure, we obtained measurements proximally to the isocenter, fitted to an exponential function, and extrapolated dose to the fundus of the uterus, uterine midpoint, and pubic synthesis for both the preliminary and delivered plans. Results: The R-squared fit for the delivered doses was 0.995. The estimated fetal doses for the 72 minute preliminary and 138 minute delivered plans range from 0.0014 to 0.028cGy and 0.07 to 0.38cGy, respectively. MOSFET readings during treatment were just above background for the thyroid and negligible for all inferior positions. The method for estimating fetal dose from plan shot information was within 0.2cGy of the measured values at 14cm cranial to the fetal location. Conclusion: Estimated fetal doses for both the preliminary and delivered plan were well below the 5cGy recommended limit. Due to Pefexion shielding, internal dose is primarily governed by attenuation and drops off exponentially. This is the first work that reports fetal dose for a GK Perfexion unit. Although multiple lesions were treated and the duration of treatment was long, the estimated fetal dose remained very low.« less

Plasma brake model for preliminary mission analysis

NASA Astrophysics Data System (ADS)

Orsini, Leonardo; Niccolai, Lorenzo; Mengali, Giovanni; Quarta, Alessandro A.

2018-03-01

Plasma brake is an innovative propellantless propulsion system concept that exploits the Coulomb collisions between a charged tether and the ions in the surrounding environment (typically, the ionosphere) to generate an electrostatic force orthogonal to the tether direction. Previous studies on the plasma brake effect have emphasized the existence of a number of different parameters necessary to obtain an accurate description of the propulsive acceleration from a physical viewpoint. The aim of this work is to discuss an analytical model capable of estimating, with the accuracy required by a preliminary mission analysis, the performance of a spacecraft equipped with a plasma brake in a (near-circular) low Earth orbit. The simplified mathematical model is first validated through numerical simulations, and is then used to evaluate the plasma brake performance in some typical mission scenarios, in order to quantify the influence of the system parameters on the mission performance index.

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions, 2

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1976-01-01

The problem of obtaining numerically maximum likelihood estimates of the parameters for a mixture of normal distributions is addressed. In recent literature, a certain successive approximations procedure, based on the likelihood equations, is shown empirically to be effective in numerically approximating such maximum-likelihood estimates; however, the reliability of this procedure was not established theoretically. Here, a general iterative procedure is introduced, of the generalized steepest-ascent (deflected-gradient) type, which is just the procedure known in the literature when the step-size is taken to be 1. With probability 1 as the sample size grows large, it is shown that this procedure converges locally to the strongly consistent maximum-likelihood estimate whenever the step-size lies between 0 and 2. The step-size which yields optimal local convergence rates for large samples is determined in a sense by the separation of the component normal densities and is bounded below by a number between 1 and 2.

A study of methods to estimate debris flow velocity

USGS Publications Warehouse

Prochaska, A.B.; Santi, P.M.; Higgins, J.D.; Cannon, S.H.

2008-01-01

Debris flow velocities are commonly back-calculated from superelevation events which require subjective estimates of radii of curvature of bends in the debris flow channel or predicted using flow equations that require the selection of appropriate rheological models and material property inputs. This research investigated difficulties associated with the use of these conventional velocity estimation methods. Radii of curvature estimates were found to vary with the extent of the channel investigated and with the scale of the media used, and back-calculated velocities varied among different investigated locations along a channel. Distinct populations of Bingham properties were found to exist between those measured by laboratory tests and those back-calculated from field data; thus, laboratory-obtained values would not be representative of field-scale debris flow behavior. To avoid these difficulties with conventional methods, a new preliminary velocity estimation method is presented that statistically relates flow velocity to the channel slope and the flow depth. This method presents ranges of reasonable velocity predictions based on 30 previously measured velocities. ?? 2008 Springer-Verlag.

Preliminary assessment of appropriateness of emergency care service use: actions taken and consultations obtained before emergency care presentation.

PubMed

Tzeng, Huey-Ming

2011-01-01

Inappropriate use of emergency care services can increase hospital readmissions and related costs. This pilot, cross-sectional survey project determined whether home health care patients who receive emergency care services during a Medicare-approved home care episode sought consultation from health care professionals before they made the emergency care visit. The two research questions were: (a) What actions were taken by the patient before making an emergency care visit?; (b) If prior consultation was obtained, what were the suggestions? Preliminary data were obtained from a Michigan-based, Medicare-certified, not-for-profit home health agency affiliated with a university health system. A two-page questionnaire recorded up to three emergency care visits. Volunteer participants were Medicare patients who had no cognitive deficits and were able to communicate with home health care providers (HHCPs) by themselves. Thirty-five emergency care visits were reported; 31 (88.6%) Medicare patients participated and 4 (11.4%) of them had two emergency care visits. Before the patients made an emergency care visit, they most often called their primary care physicians (PCPs; N = 20, 57.1%), followed by the HHCPs (N = 10, 28.6%). All 20 patients who contacted their PCPs and 7 patients who contacted their HHCPs were advised to seek emergency care services. In 20 emergency care visits the patient was admitted for an acute hospital stay; the other 15 patients went home. Most patients contacted their PCPs or HHCPs before they went to an emergency department or urgent care facility. These results implied that PCPs and HHCPs seemed to perceive that the need for emergency care should be determined at an emergency room or urgent care facility. This study was unable to differentiate the need for emergency care services or the appropriateness of the advice given by PCPs or HHCPs when the home care patients were under the care of a medical team.

A convenient method of obtaining percentile norms and accompanying interval estimates for self-report mood scales (DASS, DASS-21, HADS, PANAS, and sAD).

PubMed

Crawford, John R; Garthwaite, Paul H; Lawrie, Caroline J; Henry, Julie D; MacDonald, Marie A; Sutherland, Jane; Sinha, Priyanka

2009-06-01

A series of recent papers have reported normative data from the general adult population for commonly used self-report mood scales. To bring together and supplement these data in order to provide a convenient means of obtaining percentile norms for the mood scales. A computer program was developed that provides point and interval estimates of the percentile rank corresponding to raw scores on the various self-report scales. The program can be used to obtain point and interval estimates of the percentile rank of an individual's raw scores on the DASS, DASS-21, HADS, PANAS, and sAD mood scales, based on normative sample sizes ranging from 758 to 3822. The interval estimates can be obtained using either classical or Bayesian methods as preferred. The computer program (which can be downloaded at www.abdn.ac.uk/~psy086/dept/MoodScore.htm) provides a convenient and reliable means of supplementing existing cut-off scores for self-report mood scales.

Uncertainty Estimates of Psychoacoustic Thresholds Obtained from Group Tests

NASA Technical Reports Server (NTRS)

Rathsam, Jonathan; Christian, Andrew

2016-01-01

Adaptive psychoacoustic test methods, in which the next signal level depends on the response to the previous signal, are the most efficient for determining psychoacoustic thresholds of individual subjects. In many tests conducted in the NASA psychoacoustic labs, the goal is to determine thresholds representative of the general population. To do this economically, non-adaptive testing methods are used in which three or four subjects are tested at the same time with predetermined signal levels. This approach requires us to identify techniques for assessing the uncertainty in resulting group-average psychoacoustic thresholds. In this presentation we examine the Delta Method of frequentist statistics, the Generalized Linear Model (GLM), the Nonparametric Bootstrap, a frequentist method, and Markov Chain Monte Carlo Posterior Estimation and a Bayesian approach. Each technique is exercised on a manufactured, theoretical dataset and then on datasets from two psychoacoustics facilities at NASA. The Delta Method is the simplest to implement and accurate for the cases studied. The GLM is found to be the least robust, and the Bootstrap takes the longest to calculate. The Bayesian Posterior Estimate is the most versatile technique examined because it allows the inclusion of prior information.

Fast noise level estimation algorithm based on principal component analysis transform and nonlinear rectification

NASA Astrophysics Data System (ADS)

Xu, Shaoping; Zeng, Xiaoxia; Jiang, Yinnan; Tang, Yiling

2018-01-01

We proposed a noniterative principal component analysis (PCA)-based noise level estimation (NLE) algorithm that addresses the problem of estimating the noise level with a two-step scheme. First, we randomly extracted a number of raw patches from a given noisy image and took the smallest eigenvalue of the covariance matrix of the raw patches as the preliminary estimation of the noise level. Next, the final estimation was directly obtained with a nonlinear mapping (rectification) function that was trained on some representative noisy images corrupted with different known noise levels. Compared with the state-of-art NLE algorithms, the experiment results show that the proposed NLE algorithm can reliably infer the noise level and has robust performance over a wide range of image contents and noise levels, showing a good compromise between speed and accuracy in general.

Preliminary Results of a Magnetotelluric Survey in the Center of Hawaii Island

NASA Astrophysics Data System (ADS)

Lienert, B. R.; Thomas, D. M.; Wallin, E.

2014-12-01

From 2013 up to the present we have been recording magnetotelluric (MT) data at 25 sites in a 35x25 km region (elev. 1943 m) on the saddle between the active volcano of Mauna Loa (4169 m) and the dormant volcano of Mauna Kea (4205 m) on Hawai'i Island. The MT data, particularly the electric fields, are frequently contaminated by spurious components that are not due to the plane-wave magnetic signals required for derivation of the MT impedance tensor. We therefore developed interactive graphical software (MTPlot) to plot and analyze the MT signals in the field. MTPlot allows us to quickly examine records in both the time and frequency domain to in order to judge their quality. It also transforms the data into estimates of apparent resistivity and their error in the frequency range 0.001-500 Hz. This has proved very useful for selecting suitable records for subsequent analysis. We then use multi-taper remote reference processing to obtain our final apparent resistivity estimates and their errors. We present preliminary results of one and two dimensional modeling of these estimates to obtain the three-dimensional distribution of subsurface resistivities down to depths of 5 km. The results are compared to temperatures and properties of cores obtained when we drilled a research hole to a depth of 1760 m in this same region. We shall discuss how our results relate to the extent of the fresh-water and geothermal energy reservoirs that we discovered during drilling.

The "covariation method" for estimating the parameters of the standard Dynamic Energy Budget model II: Properties and preliminary patterns

NASA Astrophysics Data System (ADS)

Lika, Konstadia; Kearney, Michael R.; Kooijman, Sebastiaan A. L. M.

2011-11-01

The covariation method for estimating the parameters of the standard Dynamic Energy Budget (DEB) model provides a single-step method of accessing all the core DEB parameters from commonly available empirical data. In this study, we assess the robustness of this parameter estimation procedure and analyse the role of pseudo-data using elasticity coefficients. In particular, we compare the performance of Maximum Likelihood (ML) vs. Weighted Least Squares (WLS) approaches and find that the two approaches tend to converge in performance as the number of uni-variate data sets increases, but that WLS is more robust when data sets comprise single points (zero-variate data). The efficiency of the approach is shown to be high, and the prior parameter estimates (pseudo-data) have very little influence if the real data contain information about the parameter values. For instance, the effects of the pseudo-value for the allocation fraction κ is reduced when there is information for both growth and reproduction, that for the energy conductance is reduced when information on age at birth and puberty is given, and the effects of the pseudo-value for the maturity maintenance rate coefficient are insignificant. The estimation of some parameters (e.g., the zoom factor and the shape coefficient) requires little information, while that of others (e.g., maturity maintenance rate, puberty threshold and reproduction efficiency) require data at several food levels. The generality of the standard DEB model, in combination with the estimation of all of its parameters, allows comparison of species on the basis of parameter values. We discuss a number of preliminary patterns emerging from the present collection of parameter estimates across a wide variety of taxa. We make the observation that the estimated value of the fraction κ of mobilised reserve that is allocated to soma is far away from the value that maximises reproduction. We recognise this as the reason why two very different

Cost and size estimates for an electrochemical bulk energy storage concept

NASA Technical Reports Server (NTRS)

Warshay, M.; Wright, L. O.

1975-01-01

Preliminary capital cost and size estimates were made for a titanium trichloride, titanium tetrachloride, ferric chloride, ferrous chloride redox-flow-cell electric power system. On the basis of these preliminary estimates plus other important considerations, this electrochemical system emerged as having great promise as a bulk energy storage system for power load leveling. The size of this system is less than two per cent of that of a comparable pumped hydroelectric plant. The estimated capital cost of a 10 MW, 60- and 85-MWh redox-flow system compared well with that of competing systems.

Albedo estimation using near infrared photography at Glaciar Norte of Citlaltepetl Volcano (Mexico).

NASA Astrophysics Data System (ADS)

Ontiveros, Guillermo; Delgado-Granados, Hugo

2015-04-01

In this work we show preliminary results of the application of the methodology proposed by Corripio (2004) for albedo estimation of a glacial surface using oblique photography. This analysis was performed for the Glaciar Norte of Citlaltepetl volcano (Mexico), using images obtained with a modified digital camera for capturing the portion of the near infrared spectrum starting at 950 nm and a digital elevation model with a grid of 2 m. The main goal was to obtain a picture of the spatial distribution of albedo on the glacier, in order to find out if there was any morphological evidence of the influence of the glacier energy balance. Some of the obtained results show a certain spatial distribution with comparatively higher albedo values at the lower parts of the glacier as compared with higher parts. The higher values may correspond to different metamorphism of snow/ice at different heights due to the effects of lower slope. Corripio, J. G. (2004). Snow surface albedo estimation using terrestrial photography. International journal of remote sensing, 25(24), 5705-5729.

Greenhouse gases inventory and carbon balance of two dairy systems obtained from two methane-estimation methods.

PubMed

Cunha, C S; Lopes, N L; Veloso, C M; Jacovine, L A G; Tomich, T R; Pereira, L G R; Marcondes, M I

2016-11-15

The adoption of carbon inventories for dairy farms in tropical countries based on models developed from animals and diets of temperate climates is questionable. Thus, the objectives of this study were to estimate enteric methane (CH4) emissions through the SF6 tracer gas technique and through equations proposed by the Intergovernmental Panel on Climate Change (IPCC) Tier 2 and to calculate the inventory of greenhouse gas (GHG) emissions from two dairy systems. In addition, the carbon balance of these properties was estimated using enteric CH4 emissions obtained using both methodologies. In trial 1, the CH4 emissions were estimated from seven Holstein dairy cattle categories based on the SF6 tracer gas technique and on IPCC equations. The categories used in the study were prepubertal heifers (n=6); pubertal heifers (n=4); pregnant heifers (n=5); high-producing (n=6); medium-producing (n=5); low-producing (n=4) and dry cows (n=5). Enteric methane emission was higher for the category comprising prepubertal heifers when estimated by the equations proposed by the IPCC Tier 2. However, higher CH4 emissions were estimated by the SF6 technique in the categories including medium- and high-producing cows and dry cows. Pubertal heifers, pregnant heifers, and low-producing cows had equal CH4 emissions as estimated by both methods. In trial 2, two dairy farms were monitored for one year to identify all activities that contributed in any way to GHG emissions. The total emission from Farm 1 was 3.21t CO2e/animal/yr, of which 1.63t corresponded to enteric CH4. Farm 2 emitted 3.18t CO2e/animal/yr, with 1.70t of enteric CH4. IPCC estimations can underestimate CH4 emissions from some categories while overestimate others. However, considering the whole property, these discrepancies are offset and we would submit that the equations suggested by the IPCC properly estimate the total CH4 emission and carbon balance of the properties. Thus, the IPCC equations should be utilized with

Preliminary Analysis of Fluctuations in the Received Uplink-Beacon-Power Data Obtained From the GOLD Experiments

NASA Technical Reports Server (NTRS)

Jeganathan, M.; Wilson, K. E.; Lesh, J. R.

1996-01-01

Uplink data from recent free-space optical communication experiments carried out between the Table Mountain Facility and the Japanese Engineering Test Satellite are used to study fluctuations caused by beam propagation through the atmosphere. The influence of atmospheric scintillation, beam wander and jitter, and multiple uplink beams on the statistics of power received by the satellite is analyzed and compared to experimental data. Preliminary analysis indicates the received signal obeys an approximate lognormal distribution, as predicted by the weak-turbulence model, but further characterization of other sources of fluctuations is necessary for accurate link predictions.

Preliminary analysis of fluctuations in the received uplink-beacon-power data obtained from the GOLD experiments

NASA Technical Reports Server (NTRS)

Jeganathan, M.; Wilson, K. E.; Lesh, J. R.

1996-01-01

Uplink data from recent free-space optical communication experiments carried out between the Table Mountain Facility and the Japanese Engineering Test Satellite are used to study fluctuations caused by beam propagation through the atmosphere. The influence of atmospheric scintillation, beam wander and jitter, and multiple uplink beams on the statistics of power received by the satellite is analyzed and compared to experimental data. Preliminary analysis indicates the received signal obeys an approximate lognormal distribution, as predicted by the weak-turbulence model, but further characterization of other sources of fluctuations is necessary for accurate link predictions.

Comparison of Species Richness Estimates Obtained Using Nearly Complete Fragments and Simulated Pyrosequencing-Generated Fragments in 16S rRNA Gene-Based Environmental Surveys▿ †

PubMed Central

Youssef, Noha; Sheik, Cody S.; Krumholz, Lee R.; Najar, Fares Z.; Roe, Bruce A.; Elshahed, Mostafa S.

2009-01-01

Pyrosequencing-based 16S rRNA gene surveys are increasingly utilized to study highly diverse bacterial communities, with special emphasis on utilizing the large number of sequences obtained (tens to hundreds of thousands) for species richness estimation. However, it is not yet clear how the number of operational taxonomic units (OTUs) and, hence, species richness estimates determined using shorter fragments at different taxonomic cutoffs correlates with the number of OTUs assigned using longer, nearly complete 16S rRNA gene fragments. We constructed a 16S rRNA clone library from an undisturbed tallgrass prairie soil (1,132 clones) and used it to compare species richness estimates obtained using eight pyrosequencing candidate fragments (99 to 361 bp in length) and the nearly full-length fragment. Fragments encompassing the V1 and V2 (V1+V2) region and the V6 region (generated using primer pairs 8F-338R and 967F-1046R) overestimated species richness; fragments encompassing the V3, V7, and V7+V8 hypervariable regions (generated using primer pairs 338F-530R, 1046F-1220R, and 1046F-1392R) underestimated species richness; and fragments encompassing the V4, V5+V6, and V6+V7 regions (generated using primer pairs 530F-805R, 805F-1046R, and 967F-1220R) provided estimates comparable to those obtained with the nearly full-length fragment. These patterns were observed regardless of the alignment method utilized or the parameter used to gauge comparative levels of species richness (number of OTUs observed, slope of scatter plots of pairwise distance values for short and nearly complete fragments, and nonparametric and parametric species richness estimates). Similar results were obtained when analyzing three other datasets derived from soil, adult Zebrafish gut, and basaltic formations in the East Pacific Rise. Regression analysis indicated that these observed discrepancies in species richness estimates within various regions could readily be explained by the proportions of

Kinetic Roughening and Energetics of Tetragonal Lysozyme Crystal Growth: A Preliminary Atomic Force Microscopy Investigation

NASA Technical Reports Server (NTRS)

Gorti, Sridhar; Forsythe, Elizabeth L.; Pusey, Marc L.

2004-01-01

We examined particulars of crystal growth from measurements obtained at both microscopic and molecular levels. The crystal growth measurements performed at the microscopic level are well characterized by a model that balances the flux of macromolecules towards the crystal surface with the flux of the crystal surface. Numerical evaluation of model with measurements of crystal growth, in time, provided accurate estimates for the average growth velocities. Growth velocities thus obtained were also interpreted using well-established phenomenological theories. Moreover, we find that microscopic measurements of growth velocity measurements obtained as a function of temperature best characterizes changes in crystal growth modes, when present. We also examined the possibility of detecting a change in crystal growth modes at the molecular level using atomic force microscopy, AFM. From preliminary AFM measurements performed at various supersaturations, we find that magnitude of surface height fluctuations, h(x), increases with supersaturation. Further examination of surface height fluctuations using methods established for fluctuation spectroscopy also enabled the discovery of the existence of a characteristic length, c, which may possibly determine the mode of crystal growth. Although the results are preliminary, we establish the non- critical divergence of 5 and the root-mean-square (rms) magnitude of height-height fluctuations as the kinetic roughening transition temperatures are approached. Moreover, we also examine approximate models for interpreting the non-critical behavior of both 6 and rms magnitude of height-height fluctuations, as the solution supersaturation is increased towards the kinetic roughening supersaturation.

A feasibility study on estimation of tissue mixture contributions in 3D arterial spin labeling sequence

NASA Astrophysics Data System (ADS)

Liu, Yang; Pu, Huangsheng; Zhang, Xi; Li, Baojuan; Liang, Zhengrong; Lu, Hongbing

2017-03-01

Arterial spin labeling (ASL) provides a noninvasive measurement of cerebral blood flow (CBF). Due to relatively low spatial resolution, the accuracy of CBF measurement is affected by the partial volume (PV) effect. To obtain accurate CBF estimation, the contribution of each tissue type in the mixture is desirable. In general, this can be obtained according to the registration of ASL and structural image in current ASL studies. This approach can obtain probability of each tissue type inside each voxel, but it also introduces error, which include error of registration algorithm and imaging itself error in scanning of ASL and structural image. Therefore, estimation of mixture percentage directly from ASL data is greatly needed. Under the assumption that ASL signal followed the Gaussian distribution and each tissue type is independent, a maximum a posteriori expectation-maximization (MAP-EM) approach was formulated to estimate the contribution of each tissue type to the observed perfusion signal at each voxel. Considering the sensitivity of MAP-EM to the initialization, an approximately accurate initialization was obtain using 3D Fuzzy c-means method. Our preliminary results demonstrated that the GM and WM pattern across the perfusion image can be sufficiently visualized by the voxel-wise tissue mixtures, which may be promising for the diagnosis of various brain diseases.

Dual-fuel, dual-throat engine preliminary analysis

NASA Technical Reports Server (NTRS)

Obrien, C. J.

1979-01-01

A propulsion system analysis of the dual fuel, dual throat engine for launch vehicle applications was conducted. Basic dual throat engine characterization data were obtained to allow vehicle optimization studies to be conducted. A preliminary baseline engine system was defined.

Estimation of brittleness indices for pay zone determination in a shale-gas reservoir by using elastic properties obtained from micromechanics

NASA Astrophysics Data System (ADS)

Lizcano-Hernández, Edgar G.; Nicolás-López, Rubén; Valdiviezo-Mijangos, Oscar C.; Meléndez-Martínez, Jaime

2018-04-01

The brittleness indices (BI) of gas-shales are computed by using their effective mechanical properties obtained from micromechanical self-consistent modeling with the purpose of assisting in the identification of the more-brittle regions in shale-gas reservoirs, i.e., the so-called ‘pay zone’. The obtained BI are plotted in lambda-rho versus mu-rho λ ρ -μ ρ and Young’s modulus versus Poisson’s ratio E-ν ternary diagrams along with the estimated elastic properties from log data of three productive shale-gas wells where the pay zone is already known. A quantitative comparison between the obtained BI and the well log data allows for the delimitation of regions where BI values could indicate the best reservoir target in regions with the highest shale-gas exploitation potential. Therefore, a range of values for elastic properties and brittleness indexes that can be used as a data source to support the well placement procedure is obtained.

The burden of chronic mercury intoxication in artisanal small-scale gold mining in Zimbabwe: data availability and preliminary estimates.

PubMed

Steckling, Nadine; Bose-O'Reilly, Stephan; Pinheiro, Paulo; Plass, Dietrich; Shoko, Dennis; Drasch, Gustav; Bernaudat, Ludovic; Siebert, Uwe; Hornberg, Claudia

2014-12-13

Artisanal small-scale gold mining (ASGM) is a poverty-driven activity practiced in over 70 countries worldwide. Zimbabwe is amongst the top ten countries using large quantities of mercury to extract gold from ore. This analysis was performed to check data availability and derive a preliminary estimate of disability-adjusted life years (DALYs) due to mercury use in ASGM in Zimbabwe. Cases of chronic mercury intoxication were identified following an algorithm using mercury-related health effects and mercury in human specimens. The sample prevalence amongst miners and controls (surveyed by the United Nations Industrial Development Organization in 2004 and the University of Munich in 2006) was determined and extrapolated to the entire population of Zimbabwe. Further epidemiological and demographic data were taken from the literature and missing data modeled with DisMod II to quantify DALYs using the methods from the Global Burden of Disease (GBD) 2004 update published by the World Health Organization (WHO). While there was no disability weight (DW) available indicating the relative disease severity of chronic mercury intoxication, the DW of a comparable disease was assigned by following the criteria 1) chronic condition, 2) triggered by a substance, and 3) causing similar health symptoms. Miners showed a sample prevalence of 72% while controls showed no cases of chronic mercury intoxication. Data availability is very limited why it was necessary to model data and make assumptions about the number of exposed population, the definition of chronic mercury intoxication, DW, and epidemiology. If these assumptions hold, the extrapolation would result in around 95,400 DALYs in Zimbabwe's total population in 2004. This analysis provides a preliminary quantification of the mercury-related health burden from ASGM based on the limited data available. If the determined assumptions hold, chronic mercury intoxication is likely to have been one of the top 20 hazards for population

Mars Rover/Sample Return - Phase A cost estimation

NASA Technical Reports Server (NTRS)

Stancati, Michael L.; Spadoni, Daniel J.

1990-01-01

This paper presents a preliminary cost estimate for the design and development of the Mars Rover/Sample Return (MRSR) mission. The estimate was generated using a modeling tool specifically built to provide useful cost estimates from design parameters of the type and fidelity usually available during early phases of mission design. The model approach and its application to MRSR are described.

Water budgets and groundwater volumes for abandoned underground mines in the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania-Preliminary estimates with identification of data needs

USGS Publications Warehouse

Goode, Daniel J.; Cravotta, Charles A.; Hornberger, Roger J.; Hewitt, Michael A.; Hughes, Robert E.; Koury, Daniel J.; Eicholtz, Lee W.

2011-01-01

This report, prepared in cooperation with the Pennsylvania Department of Environmental Protection (PaDEP), the Eastern Pennsylvania Coalition for Abandoned Mine Reclamation, and the Dauphin County Conservation District, provides estimates of water budgets and groundwater volumes stored in abandoned underground mines in the Western Middle Anthracite Coalfield, which encompasses an area of 120 square miles in eastern Pennsylvania. The estimates are based on preliminary simulations using a groundwater-flow model and an associated geographic information system that integrates data on the mining features, hydrogeology, and streamflow in the study area. The Mahanoy and Shamokin Creek Basins were the focus of the study because these basins exhibit extensive hydrologic effects and water-quality degradation from the abandoned mines in their headwaters in the Western Middle Anthracite Coalfield. Proposed groundwater withdrawals from the flooded parts of the mines and stream-channel modifications in selected areas have the potential for altering the distribution of groundwater and the interaction between the groundwater and streams in the area. Preliminary three-dimensional, steady-state simulations of groundwater flow by the use of MODFLOW are presented to summarize information on the exchange of groundwater among adjacent mines and to help guide the management of ongoing data collection, reclamation activities, and water-use planning. The conceptual model includes high-permeability mine voids that are connected vertically and horizontally within multicolliery units (MCUs). MCUs were identified on the basis of mine maps, locations of mine discharges, and groundwater levels in the mines measured by PaDEP. The locations and integrity of mine barriers were determined from mine maps and groundwater levels. The permeability of intact barriers is low, reflecting the hydraulic characteristics of unmined host rock and coal. A steady-state model was calibrated to measured groundwater

Bias Correction of MODIS AOD using DragonNET to obtain improved estimation of PM2.5

NASA Astrophysics Data System (ADS)

Gross, B.; Malakar, N. K.; Atia, A.; Moshary, F.; Ahmed, S. A.; Oo, M. M.

2014-12-01

MODIS AOD retreivals using the Dark Target algorithm is strongly affected by the underlying surface reflection properties. In particular, the operational algorithms make use of surface parameterizations trained on global datasets and therefore do not account properly for urban surface differences. This parameterization continues to show an underestimation of the surface reflection which results in a general over-biasing in AOD retrievals. Recent results using the Dragon-Network datasets as well as high resolution retrievals in the NYC area illustrate that this is even more significant at the newest C006 3 km retrievals. In the past, we used AERONET observation in the City College to obtain bias-corrected AOD, but the homogeneity assumptions using only one site for the region is clearly an issue. On the other hand, DragonNET observations provide ample opportunities to obtain better tuning the surface corrections while also providing better statistical validation. In this study we present a neural network method to obtain bias correction of the MODIS AOD using multiple factors including surface reflectivity at 2130nm, sun-view geometrical factors and land-class information. These corrected AOD's are then used together with additional WRF meteorological factors to improve estimates of PM2.5. Efforts to explore the portability to other urban areas will be discussed. In addition, annual surface ratio maps will be developed illustrating that among the land classes, the urban pixels constitute the largest deviations from the operational model.

Preliminary plan for testing a thermionic reactor in the Plum Brook Space Power Facility

NASA Technical Reports Server (NTRS)

Haley, F. A.

1972-01-01

A preliminary plan is presented for testing a thermionic reactor in the Plum Brook Space Power Facility (SPF). A technical approach, cost estimate, manpower estimate, and schedule are presented to cover a 2 year full power reactor test.

Obtaining continuous BrAC/BAC estimates in the field: A hybrid system integrating transdermal alcohol biosensor, Intellidrink smartphone app, and BrAC Estimator software tools.

PubMed

Luczak, Susan E; Hawkins, Ashley L; Dai, Zheng; Wichmann, Raphael; Wang, Chunming; Rosen, I Gary

2018-08-01

Biosensors have been developed to measure transdermal alcohol concentration (TAC), but converting TAC into interpretable indices of blood/breath alcohol concentration (BAC/BrAC) is difficult because of variations that occur in TAC across individuals, drinking episodes, and devices. We have developed mathematical models and the BrAC Estimator software for calibrating and inverting TAC into quantifiable BrAC estimates (eBrAC). The calibration protocol to determine the individualized parameters for a specific individual wearing a specific device requires a drinking session in which BrAC and TAC measurements are obtained simultaneously. This calibration protocol was originally conducted in the laboratory with breath analyzers used to produce the BrAC data. Here we develop and test an alternative calibration protocol using drinking diary data collected in the field with the smartphone app Intellidrink to produce the BrAC calibration data. We compared BrAC Estimator software results for 11 drinking episodes collected by an expert user when using Intellidrink versus breath analyzer measurements as BrAC calibration data. Inversion phase results indicated the Intellidrink calibration protocol produced similar eBrAC curves and captured peak eBrAC to within 0.0003%, time of peak eBrAC to within 18min, and area under the eBrAC curve to within 0.025% alcohol-hours as the breath analyzer calibration protocol. This study provides evidence that drinking diary data can be used in place of breath analyzer data in the BrAC Estimator software calibration procedure, which can reduce participant and researcher burden and expand the potential software user pool beyond researchers studying participants who can drink in the laboratory. Copyright © 2017. Published by Elsevier Ltd.

Estimating landslide losses - preliminary results of a seven-State pilot project

USGS Publications Warehouse

Highland, Lynn M.

2006-01-01

reliable information on economic losses associated with landslides. Each State survey examined the availability, distribution, and inherent uncertainties of economic loss data in their study areas. Their results provide the basis for identifying the most fruitful methods of collecting landslide loss data nationally, using methods that are consistent and provide common goals. These results can enhance and establish the future directions of scientific investigation priorities by convincingly documenting landslide risks and consequences that are universal throughout the 50 States. This report is organized as follows: A general summary of the pilot project history, goals, and preliminary conclusions from the Lincoln, Neb. workshop are presented first. Internet links are then provided for each State report, which appear on the internet in PDF format and which have been placed at the end of this open-file report. A reference section follows the reports, and, lastly, an Appendix of categories of landslide loss and sources of loss information is included for the reader's information. Please note: The Oregon Geological Survey has also submitted a preliminary report on indirect loss estimation methodology, which is also linked with the others. Each State report is unique and presented in the form in which it was submitted, having been independently peer reviewed by each respective State survey. As such, no universal 'style' or format has been adopted as there have been no decisions on which inventory methods will be recommended to the 50 states, as of this writing. The reports are presented here as information for decision makers, and for the record; although several reports provide recommendations on inventory methods that could be adopted nationwide, currently no decisions have been made on adopting a uniform methodology for the States.

Preliminary results on heavy flavor physics at SLD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Usher, T.

1994-12-01

The author reports on preliminary heavy flavor physics results from the SLD detector at the SLAC Linear Collider. Efficient tagging of b{bar b} events is achieved with an impact parameter technique that takes advantage of the small and stable interaction point of the SLC and all charged tracks in Z{sup 0} decays. This technique is applied to samples of Z{sup 0} events collected during the 1992 and 1993 physics runs. Preliminary measurements of the ratio R{sub b} = {Gamma}(Z{sup 0} {yields} b{bar b})/{Gamma}(Z{sup 0} {yields} hadrons) and the average B hadron lifetime <{tau}{sub B}> are reported. In a sample ofmore » 27K Z{sup 0} events, values of R{sub b} = 0.235 {+-} 0.006(stat.) {+-} 0.018(syst.) and <{tau}{sub B}> = 1.53 {+-} 0.006(stat.) {+-} 0.018(syst.) are obtained. In addition, the first measurement of the left-right asymmetry A{sub b} is reported. Using a sample of 38K Z{sup 0} events with a luminosity weighted electron polarization of 62%, the author obtains a preliminary value of A{sub b} = 0.94 {+-} 0.006(stat.) {+-} 0.018(syst.).« less

Empirical estimation of the arrival time of ICME Shocks

NASA Astrophysics Data System (ADS)

Shaltout, Mosalam

Empirical estimation of the arrival time of ICME Shocks Mosalam Shaltout1 ,M.Youssef 1and R.Mawad2 1 National Research Institute of Astronomy and Geophysics (NRIAG) ,Helwan -Cairo-Egypt Email: mosalamshaltout@hotmail.com 2 Faculty of Science-Monifiia University-Physics Department-Shiben Al-Koum -Monifiia-Egypt We are got the Data of the SSC events from Preliminary Reports of the ISGI (Institut de Physique du Globe, France) .Also we are selected the same CME interval 1996-2005 from SOHO/LASCO/C2.We have estimated the arrival time of ICME shocks during solar cycle 23rd (1996-2005), we take the Sudden storm commencement SSC as a indicator of the arrival of CMEs at the Earth's Magnetosphere (ICME).Under our model ,we selected 203 ICME shock-SSC associated events, we got an imperial relation between CME velocity and their travel time, from which we obtained high correlation between them, R=0.75.

Preliminary data for northern Great Plains test well 1, quarter NE quarter Sec. 11, T.55N., R.77W., Sheridan County, Wyoming

USGS Publications Warehouse

Lobmeyer, D.H.; Anna, L.O.; Busby, J.F.

1982-01-01

This report documents the preliminary data obtained from Northern Great Plains test well 1 and describes the preliminary results and future testing plans. The intended audience includes hydrologists, local water users, drilling contractors, and water managers. The test well was drilled as part of the study to determine the water resource potential of the regional aquifer system in the Northern Great Plains, an area of about 250,000 sq mi. The well is 4,485 ft deep; nine cores were drilled totaling 182 ft; 157.42 ft of core were recovered. Sidewall cores were obtained from 24 horizons. Gamma and density scans of the cores were made, and selected parts were tested for density, porosity, and vertical and horizontal permeability. Eight zones were perforated and tested using conventional drill-stem tests and swabbing. Water samples were obtained from seven zones. No major potential sources of groundwater were penetrated by the test well. Estimated yields from selected zones range from about 240 gal/min with 400 ft of drawdown to about 5 gal/min flow at the surface. Dissolved-solids concentrations ranged from about 1,800 to 3,000 mg/l. (USGS)

Age estimation by pulp-to-tooth area ratio using cone-beam computed tomography: A preliminary analysis.

PubMed

Rai, Arpita; Acharya, Ashith B; Naikmasur, Venkatesh G

2016-01-01

Age estimation of living or deceased individuals is an important aspect of forensic sciences. Conventionally, pulp-to-tooth area ratio (PTR) measured from periapical radiographs have been utilized as a nondestructive method of age estimation. Cone-beam computed tomography (CBCT) is a new method to acquire three-dimensional images of the teeth in living individuals. The present study investigated age estimation based on PTR of the maxillary canines measured in three planes obtained from CBCT image data. Sixty subjects aged 20-85 years were included in the study. For each tooth, mid-sagittal, mid-coronal, and three axial sections-cementoenamel junction (CEJ), one-fourth root level from CEJ, and mid-root-were assessed. PTR was calculated using AutoCAD software after outlining the pulp and tooth. All statistical analyses were performed using an SPSS 17.0 software program. Linear regression analysis showed that only PTR in axial plane at CEJ had significant age correlation ( r = 0.32; P < 0.05). This is probably because of clearer demarcation of pulp and tooth outline at this level.

Preliminary estimates of residence times and apparent ages of ground water in the Chesapeake Bay watershed, and water-quality data from a survey of springs

USGS Publications Warehouse

Focazio, Michael J.; Plummer, Niel; Bohlke, John K.; Busenberg, Eurybiades; Bachman, L. Joseph; Powars, David S.

1998-01-01

Knowledge of the residence times of the ground-water systems in Chesapeake Bay watershed helps resource managers anticipate potential delays between implementation of land-management practices and any improve-ments in river and estuary water quality. This report presents preliminary estimates of ground-water residence times and apparent ages of water in the shallow aquifers of the Chesapeake Bay watershed. A simple reservoir model, published data, and analyses of spring water were used to estimate residence times and apparent ages of ground-water discharge. Ranges of aquifer hydraulic characteristics throughout the Bay watershed were derived from published literature and were used to estimate ground-water residence times on the basis of a simple reservoir model. Simple combinations of rock type and physiographic province were used to delineate hydrogeomorphic regions (HGMR?s) for the study area. The HGMR?s are used to facilitate organization and display of the data and analyses. Illustrations depicting the relation of aquifer characteristics and associated residence times as a continuum for each HGMR were developed. In this way, the natural variation of aquifer characteristics can be seen graphically by use of data from selected representative studies. Water samples collected in September and November 1996, from 46 springs throughout the watershed were analyzed for chlorofluorocarbons (CFC?s) to estimate the apparent age of ground water. For comparison purposes, apparent ages of water from springs were calculated assuming piston flow. Additi-onal data are given to estimate apparent ages assuming an exponential distribution of ages in spring discharge. Additionally, results from previous studies of CFC-dating of ground water from other springs and wells in the watershed were compiled. The CFC data, and the data on major ions, nutrients, and nitrogen isotopes in the water collected from the 46 springs are included in this report. The apparent ages of water

Probabilities and statistics for backscatter estimates obtained by a scatterometer

NASA Technical Reports Server (NTRS)

Pierson, Willard J., Jr.

1989-01-01

Methods for the recovery of winds near the surface of the ocean from measurements of the normalized radar backscattering cross section must recognize and make use of the statistics (i.e., the sampling variability) of the backscatter measurements. Radar backscatter values from a scatterometer are random variables with expected values given by a model. A model relates backscatter to properties of the waves on the ocean, which are in turn generated by the winds in the atmospheric marine boundary layer. The effective wind speed and direction at a known height for a neutrally stratified atmosphere are the values to be recovered from the model. The probability density function for the backscatter values is a normal probability distribution with the notable feature that the variance is a known function of the expected value. The sources of signal variability, the effects of this variability on the wind speed estimation, and criteria for the acceptance or rejection of models are discussed. A modified maximum likelihood method for estimating wind vectors is described. Ways to make corrections for the kinds of errors found for the Seasat SASS model function are described, and applications to a new scatterometer are given.

12 CFR 611.1250 - Preliminary exit fee estimate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... independently audited by a qualified public accountant. We may, in our discretion, waive the audit requirement... termination. Related expenses include, but are not limited to, legal services, accounting services, tax... institution and its stockholders. (ii) Subtract the dollar amount of estimated current and deferred tax...

Porous titanium obtained by a new powder metallurgy technique: Preliminary results of human osteoblast adhesion on surface polished substrates.

PubMed

Biasotto, M; Ricceri, R; Scuor, N; Schmid, C; Sandrucci, M A; Di Lenarda, R; Matteazzi, P

2003-01-01

This study concerns a novel powder metallurgy method for producing porous titanium (pTi) exhibiting high mechanical properties. The preparation procedure consisted of the following stages: first, the preparation of Ti and titanium hydride (TiH2) powder mixtures and their consolidation with a cold isostatic press, followed by a sintering of the green bodies performed with hot isostatic press (HIP) equipment. Thermal decomposition in controlled environment of the TiH2 phase results in the foam structure. The resulting porosity percolates with a volume fraction of approximately 20%. The final material exhibits interesting mechanical properties, comparable to those of full density titanium (between grade 2 and grade 3), with the advantage of a minor density. The samples produced were tested to verify their biological response by studying the effectiveness of osteoblast adhesion and growth. In this preliminary study, osteoblastic cell morphology was investigated and compared to that observed on fully dense commercially pure titanium (Ti-cp) (ASTM, grade 3). The preliminary results were promising regarding cellular adhesion and spreading. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 172-7).

Reverberant shear wave fields and estimation of tissue properties

NASA Astrophysics Data System (ADS)

Parker, Kevin J.; Ormachea, Juvenal; Zvietcovich, Fernando; Castaneda, Benjamin

2017-02-01

The determination of shear wave speed is an important subject in the field of elastography, since elevated shear wave speeds can be directly linked to increased stiffness of tissues. MRI and ultrasound scanners are frequently used to detect shear waves and a variety of estimators are applied to calculate the underlying shear wave speed. The estimators can be relatively simple if plane wave behavior is assumed with a known direction of propagation. However, multiple reflections from organ boundaries and internal inhomogeneities and mode conversions can create a complicated field in time and space. Thus, we explore the mathematics of multiple component shear wave fields and derive the basic properties, from which efficient estimators can be obtained. We approach this problem from the historic perspective of reverberant fields, a conceptual framework used in architectural acoustics and related fields. The framework can be recast for the alternative case of shear waves in a bounded elastic media, and the expected value of displacement patterns in shear reverberant fields are derived, along with some practical estimators of shear wave speed. These are applied to finite element models and phantoms to illustrate the characteristics of reverberant fields and provide preliminary confirmation of the overall framework.

Estimating Evaporative Fraction From Readily Obtainable Variables in Mangrove Forests of the Everglades, U.S.A.

NASA Technical Reports Server (NTRS)

Yagci, Ali Levent; Santanello, Joseph A.; Jones, John; Barr, Jordan

2017-01-01

A remote-sensing-based model to estimate evaporative fraction (EF) the ratio of latent heat (LE; energy equivalent of evapotranspiration -ET-) to total available energy from easily obtainable remotely-sensed and meteorological parameters is presented. This research specifically addresses the shortcomings of existing ET retrieval methods such as calibration requirements of extensive accurate in situ micro-meteorological and flux tower observations, or of a large set of coarse-resolution or model-derived input datasets. The trapezoid model is capable of generating spatially varying EF maps from standard products such as land surface temperature [T(sub s)] normalized difference vegetation index (NDVI)and daily maximum air temperature [T(sub a)]. The 2009 model results were validated at an eddy-covariance tower (Fluxnet ID: US-Skr) in the Everglades using T(sub s) and NDVI products from Landsat as well as the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. Results indicate that the model accuracy is within the range of instrument uncertainty, and is dependent on the spatial resolution and selection of end-members (i.e. wet/dry edge). The most accurate results were achieved with the T(sub s) from Landsat relative to the T(sub s) from the MODIS flown on the Terra and Aqua platforms due to the fine spatial resolution of Landsat (30 m). The bias, mean absolute percentage error and root mean square percentage error were as low as 2.9% (3.0%), 9.8% (13.3%), and 12.1% (16.1%) for Landsat-based (MODIS-based) EF estimates, respectively. Overall, this methodology shows promise for bridging the gap between temporally limited ET estimates at Landsat scales and more complex and difficult to constrain global ET remote-sensing models.

Estimating evaporative fraction from readily obtainable variables in mangrove forests of the Everglades, U.S.A.

USGS Publications Warehouse

Yagci, Ali Levent; Santanello, Joseph A.; Jones, John W.; Barr, Jordan G.

2017-01-01

A remote-sensing-based model to estimate evaporative fraction (EF) – the ratio of latent heat (LE; energy equivalent of evapotranspiration –ET–) to total available energy – from easily obtainable remotely-sensed and meteorological parameters is presented. This research specifically addresses the shortcomings of existing ET retrieval methods such as calibration requirements of extensive accurate in situ micrometeorological and flux tower observations or of a large set of coarse-resolution or model-derived input datasets. The trapezoid model is capable of generating spatially varying EF maps from standard products such as land surface temperature (Ts) normalized difference vegetation index (NDVI) and daily maximum air temperature (Ta). The 2009 model results were validated at an eddy-covariance tower (Fluxnet ID: US-Skr) in the Everglades using Ts and NDVI products from Landsat as well as the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. Results indicate that the model accuracy is within the range of instrument uncertainty, and is dependent on the spatial resolution and selection of end-members (i.e. wet/dry edge). The most accurate results were achieved with the Ts from Landsat relative to the Ts from the MODIS flown on the Terra and Aqua platforms due to the fine spatial resolution of Landsat (30 m). The bias, mean absolute percentage error and root mean square percentage error were as low as 2.9% (3.0%), 9.8% (13.3%), and 12.1% (16.1%) for Landsat-based (MODIS-based) EF estimates, respectively. Overall, this methodology shows promise for bridging the gap between temporally limited ET estimates at Landsat scales and more complex and difficult to constrain global ET remote-sensing models.

Effect of the ultrasound-assisted preliminary maceration on the efficiency of the essential oil distillation from selected herbal raw materials.

PubMed

Kowalski, Radosław; Kowalska, Grażyna; Jamroz, Jerzy; Nawrocka, Agnieszka; Metyk, Damian

2015-05-01

The objective of the study was the estimation of the ultrasound-assisted preliminary maceration effect on the efficiency of essential oil distillation and on its qualitative and quantitative composition. The experiment included analyses on three herbal materials, i.e. peppermint leaves (Mentha piperita L.), marjoram herb (Origanum majorana L.), and chamomile flowers (Chamomilla recutita (L.) Rauschert). The study showed that the application of preliminary water maceration of raw material, augmented with ultrasounds, had a statistically significant increasing effect on the amount of oil distilled, in the case of mint leaf from 1.32% to 1.46% v/w, and in the case of marjoram herb from 1.13% to 1.27% v/w. In the case of chamomile flowers no significant effect of ultrasound on the amount of oil obtained was observed. Generally, comparing the composition of essential oils obtained in the experiments with the requirements of the relevant standards no unfavourable effect of the distillation augmenting techniques applied was noted. Therefore, it should be expected that the studied distillates of volatile fractions will have the desired biological activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Gas geochemistry and preliminary CO2 output estimation from the island of Kos (Greece)

NASA Astrophysics Data System (ADS)

D'Alessandro, Walter; Daskalopoulou, Kyriaki; Calabrese, Sergio; Longo, Manfredi; Kyriakopoulos, Konstantinos; Gagliano, Antonina Lisa

2017-04-01

Several gas samples have been collected from natural gas manifestations at the island of Kos. Most of them are found underwater along the southern coast of the island. On land two anomalous degassing areas have been recognized. These are characterised by lack of vegetation and after long dry periods by the presence of sulfate salts efflorescences. Almost all the gases are CO2-dominated (CO2 ranging from 88 to 99%) with minor amounts of N2 (up to 7%) and CH4 (up to 2.6%). Only the on-land manifestations have also significant contents of H2 (up to 0.2%) and H2S (up to 0.3%). Only one underwater manifestation is N2-dominated (61-99%) with CH4 (0.6-11%) and low CO2 (0.1-26%). The isotopic composition of He shows values ranging from 0.84 to 6.72 R/RA indicating a sometimes strong mantle contribution with the highest values measured in two of the most strongly degassing areas (Paradise Beach and Volcania). C-isotopic composition of CO2 is in the range from -3.6 to 0.6 ‰ vs V-PDB with most of the values around -1‰ indicating a mixed mantle - limestones origin. Isotopic composition of CH4, ranging from -21.5 to 2.8‰ for C and from -143 to 36‰ for H, points to a geothermal origin with sometimes evident secondary oxidation processes. CO2-flux measurements showed values up to about 10,000 g/m2/day in the areas of Volcania and Kokkino Nero and up to about 50,000 g/m2/day at Paradise beach. Preliminary CO2 output estimations gave values of 8.8 and 4 tons/day for the first two areas respectively and of 2.7 tons/day for the latter. The total output of the island (15.5 tons/day) should be considered a minimum estimation because of the incomplete coverage of the area and is comparable to the other active volcanic/geothermal systems of Greece (Nisyros, Nea Kameni and Methana).

Age estimation by pulp-to-tooth area ratio using cone-beam computed tomography: A preliminary analysis

PubMed Central

Rai, Arpita; Acharya, Ashith B.; Naikmasur, Venkatesh G.

2016-01-01

Background: Age estimation of living or deceased individuals is an important aspect of forensic sciences. Conventionally, pulp-to-tooth area ratio (PTR) measured from periapical radiographs have been utilized as a nondestructive method of age estimation. Cone-beam computed tomography (CBCT) is a new method to acquire three-dimensional images of the teeth in living individuals. Aims: The present study investigated age estimation based on PTR of the maxillary canines measured in three planes obtained from CBCT image data. Settings and Design: Sixty subjects aged 20–85 years were included in the study. Materials and Methods: For each tooth, mid-sagittal, mid-coronal, and three axial sections—cementoenamel junction (CEJ), one-fourth root level from CEJ, and mid-root—were assessed. PTR was calculated using AutoCAD software after outlining the pulp and tooth. Statistical Analysis Used: All statistical analyses were performed using an SPSS 17.0 software program. Results and Conclusions: Linear regression analysis showed that only PTR in axial plane at CEJ had significant age correlation (r = 0.32; P < 0.05). This is probably because of clearer demarcation of pulp and tooth outline at this level. PMID:28123269

Preliminary Study of a Piston Pump for Cryogenic Fluids

NASA Technical Reports Server (NTRS)

Biermann, Arnold E.; Kohl, Robert C.

1959-01-01

Preliminary data are presented covering the performance of a low-speed, five-cylinder piston pump designed for handling boiling hydrogen. This pump was designed for a flow of 55 gallons per minute at 240 rpm with a discharge pressure of 135 pounds per square inch. Tests were made using JP-4 fuel, liquid nitrogen, and liquid hydrogen. Pump delivery and endurance characteristics were satisfactory for the range of operation covered. In connection with the foregoing pump development, the cavitation characteristics of a preliminary visual model, glass-cylinder pump and of a simple reciprocating disk were studied. Subcooling of approximately 0.60 F was obtained from the cavitation produced by reciprocating a disk in boiling nitrogen and in boiling water. The subcooling obtained in a similar manner with liquid hydrogen was somewhat less.

Estimator banks: a new tool for direction-of-arrival estimation

NASA Astrophysics Data System (ADS)

Gershman, Alex B.; Boehme, Johann F.

1997-10-01

A new powerful tool for improving the threshold performance of direction-of-arrival (DOA) estimation is considered. The essence of our approach is to reduce the number of outliers in the threshold domain using the so-called estimator bank containing multiple 'parallel' underlying DOA estimators which are based on pseudorandom resampling of the MUSIC spatial spectrum for given data batch or sample covariance matrix. To improve the threshold performance relative to conventional MUSIC, evolutionary principles are used, i.e., only 'successful' underlying estimators (having no failure in the preliminary estimated source localization sectors) are exploited in the final estimate. An efficient beamspace root implementation of the estimator bank approach is developed, combined with the array interpolation technique which enables the application to arbitrary arrays. A higher-order extension of our approach is also presented, where the cumulant-based MUSIC estimator is exploited as a basic technique for spatial spectrum resampling. Simulations and experimental data processing show that our algorithm performs well below the MUSIC threshold, namely, has the threshold performance similar to that of the stochastic ML method. At the same time, the computational cost of our algorithm is much lower than that of stochastic ML because no multidimensional optimization is involved.

Estimation of the Relative Severity of Floods in Small Ungauged Catchments for Preliminary Observations on Flash Flood Preparedness: A Case Study in Korea

PubMed Central

Kim, Eung Seok; Choi, Hyun Il

2012-01-01

An increase in the occurrence of sudden local flooding of great volume and short duration has caused significant danger and loss of life and property in Korea as well as many other parts of the World. Since such floods usually accompanied by rapid runoff and debris flow rise quite quickly with little or no advance warning to prevent flood damage, this study presents a new flash flood indexing methodology to promptly provide preliminary observations regarding emergency preparedness and response to flash flood disasters in small ungauged catchments. Flood runoff hydrographs are generated from a rainfall-runoff model for the annual maximum rainfall series of long-term observed data in the two selected small ungauged catchments. The relative flood severity factors quantifying characteristics of flood runoff hydrographs are standardized by the highest recorded maximum value, and then averaged to obtain the flash flood index only for flash flood events in each study catchment. It is expected that the regression equations between the proposed flash flood index and rainfall characteristics can provide the basis database of the preliminary information for forecasting the local flood severity in order to facilitate flash flood preparedness in small ungauged catchments. PMID:22690208

Preliminary Analysis of the BASALA-H Experimental Programme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blaise, Patrick; Fougeras, Philippe; Philibert, Herve

2002-07-01

This paper is focused on the preliminary analysis of results obtained on the first cores of the first phase of the BASALA (Boiling water reactor Advanced core physics Study Aimed at mox fuel Lattice) programme, aimed at studying the neutronic parameters in ABWR core in hot conditions, currently under investigation in the French EOLE critical facility, within the framework of a cooperation between NUPEC, CEA and Cogema. The first 'on-line' analysis of the results has been made, using a new preliminary design and safety scheme based on the French APOLLO-2 code in its 2.4 qualified version and associated CEA-93 V4more » (JEF-2.2) Library, that will enable the Experimental Physics Division (SPEx) to perform future core designs. It describes the scheme adopted and the results obtained in various cases, going to the critical size determination to the reactivity worth of the perturbed configurations (voided, over-moderated, and poisoned with Gd{sub 2}O{sub 3}-UO{sub 2} pins). A preliminary study on the experimental results on the MISTRAL-4 is resumed, and the comparison of APOLLO-2 versus MCNP-4C calculations on these cores is made. The results obtained show very good agreements between the two codes, and versus the experiment. This work opens the way to the future full analysis of the experimental results of the qualifying teams with completely validated schemes, based on the new 2.5 version of the APOLLO-2 code. (authors)« less

Orbit/attitude estimation with LANDSAT Landmark data

NASA Technical Reports Server (NTRS)

Hall, D. L.; Waligora, S.

1979-01-01

The use of LANDSAT landmark data for orbit/attitude and camera bias estimation was studied. The preliminary results of these investigations are presented. The Goddard Trajectory Determination System (GTDS) error analysis capability was used to perform error analysis studies. A number of questions were addressed including parameter observability and sensitivity, effects on the solve-for parameter errors of data span, density, and distribution an a priori covariance weighting. The use of the GTDS differential correction capability with acutal landmark data was examined. The rms line and element observation residuals were studied as a function of the solve-for parameter set, a priori covariance weighting, force model, attitude model and data characteristics. Sample results are presented. Finally, verfication and preliminary system evaluation of the LANDSAT NAVPAK system for sequential (extended Kalman Filter) estimation of orbit, and camera bias parameters is given.

Estimated burden of fungal infections in Germany.

PubMed

Ruhnke, Markus; Groll, Andreas H; Mayser, Peter; Ullmann, Andrew J; Mendling, Werner; Hof, Herbert; Denning, David W

2015-10-01

In the late 1980's, the incidence of invasive fungal diseases (IFDs) in Germany was estimated with 36.000 IFDs per year. The current number of fungal infections (FI) occurring each year in Germany is still not known. In the actual analysis, data on incidence of fungal infections in various patients groups at risk for FI were calculated and mostly estimated from various (mostly national) resources. According to the very heterogenous data resources robust data or statistics could not be obtained but preliminary estimations could be made and compared with data from other areas in the world using a deterministic model that has consistently been applied in many countries by the LIFE program ( www.LIFE-worldwide.org). In 2012, of the 80.52 million population (adults 64.47 million; 41.14 million female, 39.38 million male), 20% are children (0-14 years) and 16% of population are ≥65 years old. Using local data and literature estimates of the incidence or prevalence of fungal infections, about 9.6 million (12%) people in Germany suffer from a fungal infection each year. These figures are dominated (95%) by fungal skin disease and recurrent vulvo-vaginal candidosis. In general, considerable uncertainty surrounds the total numbers because IFDs do not belong to the list of reportable infectious diseases in Germany and most patients were not hospitalised because of the IFD but a distinct underlying disease. © 2015 Blackwell Verlag GmbH.

Benchmarking the Integration of WAVEWATCH III Results into HAZUS-MH: Preliminary Results

NASA Technical Reports Server (NTRS)

Berglund, Judith; Holland, Donald; McKellip, Rodney; Sciaudone, Jeff; Vickery, Peter; Wang, Zhanxian; Ying, Ken

2005-01-01

The report summarizes the results from the preliminary benchmarking activities associated with the use of WAVEWATCH III (WW3) results in the HAZUS-MH MR1 flood module. Project partner Applied Research Associates (ARA) is integrating the WW3 model into HAZUS. The current version of HAZUS-MH predicts loss estimates from hurricane-related coastal flooding by using values of surge only. Using WW3, wave setup can be included with surge. Loss estimates resulting from the use of surge-only and surge-plus-wave-setup were compared. This benchmarking study is preliminary because the HAZUS-MH MR1 flood module was under development at the time of the study. In addition, WW3 is not scheduled to be fully integrated with HAZUS-MH and available for public release until 2008.

Preliminary experiments on quantification of skin condition

NASA Astrophysics Data System (ADS)

Kitajima, Kenzo; Iyatomi, Hitoshi

2014-03-01

In this study, we investigated a preliminary assessment method for skin conditions such as a moisturizing property and its fineness of the skin with an image analysis only. We captured a facial images from volunteer subjects aged between 30s and 60s by Pocket Micro (R) device (Scalar Co., Japan). This device has two image capturing modes; the normal mode and the non-reflection mode with the aid of the equipped polarization filter. We captured skin images from a total of 68 spots from subjects' face using both modes (i.e. total of 136 skin images). The moisture-retaining property of the skin and subjective evaluation score of the skin fineness in 5-point scale for each case were also obtained in advance as a gold standard (their mean and SD were 35.15 +/- 3.22 (μS) and 3.45 +/- 1.17, respectively). We extracted a total of 107 image features from each image and built linear regression models for estimating abovementioned criteria with a stepwise feature selection. The developed model for estimating the skin moisture achieved the MSE of 1.92 (μS) with 6 selected parameters, while the model for skin fineness achieved that of 0.51 scales with 7 parameters under the leave-one-out cross validation. We confirmed the developed models predicted the moisture-retaining property and fineness of the skin appropriately with only captured image.

Preliminary evaluation of spectral, normal and meteorological crop stage estimation approaches

NASA Technical Reports Server (NTRS)

Cate, R. B.; Artley, J. A.; Doraiswamy, P. C.; Hodges, T.; Kinsler, M. C.; Phinney, D. E.; Sestak, M. L. (Principal Investigator)

1980-01-01

Several of the projects in the AgRISTARS program require crop phenology information, including classification, acreage and yield estimation, and detection of episodal events. This study evaluates several crop calendar estimation techniques for their potential use in the program. The techniques, although generic in approach, were developed and tested on spring wheat data collected in 1978. There are three basic approaches to crop stage estimation: historical averages for an area (normal crop calendars), agrometeorological modeling of known crop-weather relationships agrometeorological (agromet) crop calendars, and interpretation of spectral signatures (spectral crop calendars). In all, 10 combinations of planting and biostage estimation models were evaluated. Dates of stage occurrence are estimated with biases between -4 and +4 days while root mean square errors range from 10 to 15 days. Results are inconclusive as to the superiority of any of the models and further evaluation of the models with the 1979 data set is recommended.

Preliminary measurements of 135Cs with AMS

NASA Astrophysics Data System (ADS)

Yin, Xinyi; He, Ming; Dong, Kejun; Dou, Liang; Lan, Xiaoxi; Pang, Fangfang; Wu, Shaoyong; Jiang, Shan

2015-10-01

135Cs is an interesting nuclide in many research fields, especially in environmental study. Preliminary measurements of the long-lived 135Cs with accelerator mass spectrometry (AMS) have been developed with the HI-13 tandem AMS facility at China Institute of Atomic Energy (CIAE). In order to improve ion extracting current and depressing background interference, experiments were carried out on different ions of Cs extracted from different samples. It was found that Cs- extracted from CsNO3 can be used for AMS measurement of 135Cs. According to the preliminary results, the background level can be obtained with blanks was 135Ba/Cs ∼ 8.8 × 10-12 with the CIAE-AMS system.

A Preliminary Study of a Solar-Probe Mission

NASA Technical Reports Server (NTRS)

Dugan, Duane W.

1961-01-01

A preliminary study is made of some problems associated with the sending of an instrumented probe close to the Sun for the purpose of gathering and telemetering back to Earth information concerning solar phenomena and circumsolar space. The problems considered are primarily those relating to heating and to launch requirements. A nonanalytic discussion of the communications problem of a solar-probe mission is presented to obtain order-of-magnitude estimates of the output and weight of an auxiliary power supply which might be required. From the study it is believed that approaches to the Sun as close as about 4 or 5 million miles do not present insuperable difficulties insofar as heating and communications are concerned. Guidance requirements, in general, do not appear to be stringent. However, in terms of current experience, velocity requirements may be large. It is found, for example, that to achieve perihelion distances between the orbit of Mercury and the visible disc of the Sun, total burnout velocities ranging between 50,000 and 100,000 feet per second are required.

Decoding tactile afferent activity to obtain an estimate of instantaneous force and torque applied to the fingerpad

PubMed Central

Birznieks, Ingvars; Redmond, Stephen J.

2015-01-01

Dexterous manipulation is not possible without sensory information about object properties and manipulative forces. Fundamental neuroscience has been unable to demonstrate how information about multiple stimulus parameters may be continuously extracted, concurrently, from a population of tactile afferents. This is the first study to demonstrate this, using spike trains recorded from tactile afferents innervating the monkey fingerpad. A multiple-regression model, requiring no a priori knowledge of stimulus-onset times or stimulus combination, was developed to obtain continuous estimates of instantaneous force and torque. The stimuli consisted of a normal-force ramp (to a plateau of 1.8, 2.2, or 2.5 N), on top of which −3.5, −2.0, 0, +2.0, or +3.5 mNm torque was applied about the normal to the skin surface. The model inputs were sliding windows of binned spike counts recorded from each afferent. Models were trained and tested by 15-fold cross-validation to estimate instantaneous normal force and torque over the entire stimulation period. With the use of the spike trains from 58 slow-adapting type I and 25 fast-adapting type I afferents, the instantaneous normal force and torque could be estimated with small error. This study demonstrated that instantaneous force and torque parameters could be reliably extracted from a small number of tactile afferent responses in a real-time fashion with stimulus combinations that the model had not been exposed to during training. Analysis of the model weights may reveal how interactions between stimulus parameters could be disentangled for complex population responses and could be used to test neurophysiologically relevant hypotheses about encoding mechanisms. PMID:25948866

The application of parameter estimation to flight measurements to obtain lateral-directional stability derivatives of an augmented jet-flap STOL airplane

NASA Technical Reports Server (NTRS)

Stephenson, J. D.

1983-01-01

Flight experiments with an augmented jet flap STOL aircraft provided data from which the lateral directional stability and control derivatives were calculated by applying a linear regression parameter estimation procedure. The tests, which were conducted with the jet flaps set at a 65 deg deflection, covered a large range of angles of attack and engine power settings. The effect of changing the angle of the jet thrust vector was also investigated. Test results are compared with stability derivatives that had been predicted. The roll damping derived from the tests was significantly larger than had been predicted, whereas the other derivatives were generally in agreement with the predictions. Results obtained using a maximum likelihood estimation procedure are compared with those from the linear regression solutions.

Preliminary estimates of nucleon fluxes in a water target exposed to solar-flare protons: BRYNTRN versus Monte Carlo code

NASA Technical Reports Server (NTRS)

Shinn, Judy L.; Wilson, John W.; Lone, M. A.; Wong, P. Y.; Costen, Robert C.

1994-01-01

A baryon transport code (BRYNTRN) has previously been verified using available Monte Carlo results for a solar-flare spectrum as the reference. Excellent results were obtained, but the comparisons were limited to the available data on dose and dose equivalent for moderate penetration studies that involve minor contributions from secondary neutrons. To further verify the code, the secondary energy spectra of protons and neutrons are calculated using BRYNTRN and LAHET (Los Alamos High-Energy Transport code, which is a Monte Carlo code). These calculations are compared for three locations within a water slab exposed to the February 1956 solar-proton spectrum. Reasonable agreement was obtained when various considerations related to the calculational techniques and their limitations were taken into account. Although the Monte Carlo results are preliminary, it appears that the neutron albedo, which is not currently treated in BRYNTRN, might be a cause for the large discrepancy seen at small penetration depths. It also appears that the nonelastic neutron production cross sections in BRYNTRN may underestimate the number of neutrons produced in proton collisions with energies below 200 MeV. The notion that the poor energy resolution in BRYNTRN may cause a large truncation error in neutron elastic scattering requires further study.

Preliminary design of a mobile lunar power supply

NASA Technical Reports Server (NTRS)

Schmitz, Paul C.; Kenny, Barbara H.; Fulmer, Christopher R.

1991-01-01

A preliminary design for a Stirling isotope power system for use as a mobile lunar power supply is presented. Performance and mass of the components required for the system are estimated. These estimates are based on power requirements and the operating environment. Optimizations routines are used to determine minimum mass operational points. Shielding for the isotope system are given as a function of the allowed dose, distance from the source, and the time spent near the source. The technologies used in the power conversion and radiator systems are taken from ongoing research in the Civil Space Technology Initiative (CSTI) program.

Preliminary estimation of the realistic optimum temperature for vegetation growth in China.

PubMed

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

Preliminary Estimation of the Realistic Optimum Temperature for Vegetation Growth in China

NASA Astrophysics Data System (ADS)

Cui, Yaoping

2013-07-01

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford's law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.

Preliminary findings of serum creatinine and estimated glomerular filtration rate (eGFR) in adolescents with intellectual disabilities.

PubMed

Lin, Jin-Ding; Lin, Lan-Ping; Hsieh, Molly; Lin, Pei-Ying

2010-01-01

The present study aimed to describe the kidney function profile - serum creatinine and estimated glomerular filtration rate (eGFR), and to examine the relationships of predisposing factors to abnormal serum creatinine in people with intellectual disabilities (ID). Data were collected by a cross-sectional study of 827 aged 15-18 years adolescents with ID who participated in annual health examinations as they enrolled into special education schools in Taiwan. We used serum samples to determine participants' creatinine profiles, and the Cockcroft-Gault formula to calculate the data of eGFR to present the chronic kidney disease. The results found 22% of the participants have abnormal serum creatinine value (creatinine>1.0mg/dl) and 59.6%, 36.4% and 4.0% at chronic kidney disease (CKD) stage 1, 2 and 3 cases accordingly based on the Cockcroft-Gault formula. No CKD stage 4 and 5 cases in this study. That is, there were 4% CKD cases (eGFR <60 mL/min/1.73 m(2); CKD stage 3, 4 and 5) in adolescents with ID in this study. The results also indicated that gender and BMI could significantly predict abnormal creatinine condition in multivariate logistic regression analysis. Those boys with ID were more likely to have abnormal creatinine value than girls with ID (OR=10.13, 95% CI=5.96-17.23). In term of BMI, those underweight adolescents with ID were less likely to have high creatinine value compared to normal weight group (OR=0.45, 95% CI=0.28-0.72). In summary, this study provides the preliminary information of creatinine and estimated GFR in people with ID; we suggest the public health policy should initiate appropriate management strategies to monitor kidney function and to improve treatment outcomes of chronic kidney disease for this vulnerable population. Copyright © 2010 Elsevier Ltd. All rights reserved.

Estimation of porphyrin concentration in the kerogen fraction of shales using high-resolution reflectance spectroscopy

NASA Technical Reports Server (NTRS)

Holden, Peter N.; Gaffey, Michael J.; Sundararaman, P.

1991-01-01

An interpretive model for estimating porphyrin concentration in bitumen and kerogen from spectral reaflectance data in the visible and near-ultraviolet region of the spectrum is derived and calibrated. Preliminary results obtained using the model are consistent with concentrations determined from the bitumen extract and suggest that 40 to 60 percent of the total porphyrin concentration remains in the kerogen after extraction of bitumen from thermally immature samples. The reflectance technique will contribute to porphyrin and kerogen studies and can be applied at its present level of development to several areas of geologic and paleo-oceanographic research.

Estimation of the state of solar activity type stars by virtual observations of CrAVO

NASA Astrophysics Data System (ADS)

Dolgov, A. A.; Shlyapnikov, A. A.

2012-05-01

The results of precosseing of negatives with direct images of the sky from CrAO glass library are presented in this work, which became a part of on-line archive of the Crimean Astronomical Virtual Observatory (CrAVO). Based on the obtained data, the parameters of dwarf stars have been estimated, included in the catalog "Stars with solar-type activity" (GTSh10). The following matters are considered: searching methodology of negatives with positions of studied stars and with calculated limited magnitude; image viewing and reduction with the facilities of the International Virtual Observatory; the preliminary results of the photometry of studied objects.

A system level model for preliminary design of a space propulsion solid rocket motor

NASA Astrophysics Data System (ADS)

Schumacher, Daniel M.

Preliminary design of space propulsion solid rocket motors entails a combination of components and subsystems. Expert design tools exist to find near optimal performance of subsystems and components. Conversely, there is no system level preliminary design process for space propulsion solid rocket motors that is capable of synthesizing customer requirements into a high utility design for the customer. The preliminary design process for space propulsion solid rocket motors typically builds on existing designs and pursues feasible rather than the most favorable design. Classical optimization is an extremely challenging method when dealing with the complex behavior of an integrated system. The complexity and combinations of system configurations make the number of the design parameters that are traded off unreasonable when manual techniques are used. Existing multi-disciplinary optimization approaches generally address estimating ratios and correlations rather than utilizing mathematical models. The developed system level model utilizes the Genetic Algorithm to perform the necessary population searches to efficiently replace the human iterations required during a typical solid rocket motor preliminary design. This research augments, automates, and increases the fidelity of the existing preliminary design process for space propulsion solid rocket motors. The system level aspect of this preliminary design process, and the ability to synthesize space propulsion solid rocket motor requirements into a near optimal design, is achievable. The process of developing the motor performance estimate and the system level model of a space propulsion solid rocket motor is described in detail. The results of this research indicate that the model is valid for use and able to manage a very large number of variable inputs and constraints towards the pursuit of the best possible design.

Compound estimation procedures in reliability

NASA Technical Reports Server (NTRS)

Barnes, Ron

1990-01-01

At NASA, components and subsystems of components in the Space Shuttle and Space Station generally go through a number of redesign stages. While data on failures for various design stages are sometimes available, the classical procedures for evaluating reliability only utilize the failure data on the present design stage of the component or subsystem. Often, few or no failures have been recorded on the present design stage. Previously, Bayesian estimators for the reliability of a single component, conditioned on the failure data for the present design, were developed. These new estimators permit NASA to evaluate the reliability, even when few or no failures have been recorded. Point estimates for the latter evaluation were not possible with the classical procedures. Since different design stages of a component (or subsystem) generally have a good deal in common, the development of new statistical procedures for evaluating the reliability, which consider the entire failure record for all design stages, has great intuitive appeal. A typical subsystem consists of a number of different components and each component has evolved through a number of redesign stages. The present investigations considered compound estimation procedures and related models. Such models permit the statistical consideration of all design stages of each component and thus incorporate all the available failure data to obtain estimates for the reliability of the present version of the component (or subsystem). A number of models were considered to estimate the reliability of a component conditioned on its total failure history from two design stages. It was determined that reliability estimators for the present design stage, conditioned on the complete failure history for two design stages have lower risk than the corresponding estimators conditioned only on the most recent design failure data. Several models were explored and preliminary models involving bivariate Poisson distribution and the

A Preliminary Teleseismic Investigation of the Crust and Mantle Lithosphere Obtained from BISN in the Western Canadian Arctic

NASA Astrophysics Data System (ADS)

Schaeffer, A. J.; Snyder, D. B.; Cairns, S.; Elliot, B.; Audet, P.; Esteve, C.; Murray-Bergquist, L.; Falck, H.

2016-12-01

The tectonic evolution of the Beaufort Sea continental margin has contributed to the maturation of these rocks into a major petroleum reservoir. Recent shallow offshore seismic reflection data suggest that Banks Island represents thin crust along a rifted margin established during the opening of the Arctic Ocean. In this case, rifting of the margin caused Banks Island to subside and accumulate sediments rich in petroleum source material. The cooling history and further subsidence of these sediments is important for understanding the thermal maturation of petroleum products. Recently published surface-wave velocity models of North America indicate seismic velocities at 100-150 km depths similar to those beneath Canada's diamond mines in the central Slave craton north of Yellowknife. These results imply that Banks Island is part of the Canadian Shield and that any kimberlites found thereon might contain diamonds. However, the fast velocities are inconsistent with this being a tectonically disrupted and thinned lithosphere along the Arctic margin of the Canada Basin. The problem is therefore to reconcile mantle structure typical of the Canadian Shield with crust typical of a rifted passive margin. Possibly related seismicity beneath the Mackenize River Delta and offshore in the Beaufort Sea has been observed for decades but its origin remains unknown, although has been suggested as due to incipient subduction of oceanic lithosphere beneath the North American craton. Resolving these questions requires high-resolution 3-D seismic models obtained from an array of broadband seismograph stations. Here we present preliminary results on the structure of the crust and uppermost mantle underlying the western Canadian Arctic. These results are generated using new data from the Banks Island Seismograph Network (BISN), three stations installed over the summer of 2014 and 2015; augmented with several USArray Transportable Array stations and older POLARIS and CNSN stations on

Breast density estimation from high spectral and spatial resolution MRI

PubMed Central

Li, Hui; Weiss, William A.; Medved, Milica; Abe, Hiroyuki; Newstead, Gillian M.; Karczmar, Gregory S.; Giger, Maryellen L.

2016-01-01

Abstract. A three-dimensional breast density estimation method is presented for high spectral and spatial resolution (HiSS) MR imaging. Twenty-two patients were recruited (under an Institutional Review Board--approved Health Insurance Portability and Accountability Act-compliant protocol) for high-risk breast cancer screening. Each patient received standard-of-care clinical digital x-ray mammograms and MR scans, as well as HiSS scans. The algorithm for breast density estimation includes breast mask generating, breast skin removal, and breast percentage density calculation. The inter- and intra-user variabilities of the HiSS-based density estimation were determined using correlation analysis and limits of agreement. Correlation analysis was also performed between the HiSS-based density estimation and radiologists’ breast imaging-reporting and data system (BI-RADS) density ratings. A correlation coefficient of 0.91 (p<0.0001) was obtained between left and right breast density estimations. An interclass correlation coefficient of 0.99 (p<0.0001) indicated high reliability for the inter-user variability of the HiSS-based breast density estimations. A moderate correlation coefficient of 0.55 (p=0.0076) was observed between HiSS-based breast density estimations and radiologists’ BI-RADS. In summary, an objective density estimation method using HiSS spectral data from breast MRI was developed. The high reproducibility with low inter- and low intra-user variabilities shown in this preliminary study suggest that such a HiSS-based density metric may be potentially beneficial in programs requiring breast density such as in breast cancer risk assessment and monitoring effects of therapy. PMID:28042590

A comprehensive method for preliminary design optimization of axial gas turbine stages

NASA Technical Reports Server (NTRS)

Jenkins, R. M.

1982-01-01

A method is presented that performs a rapid, reasonably accurate preliminary pitchline optimization of axial gas turbine annular flowpath geometry, as well as an initial estimate of blade profile shapes, given only a minimum of thermodynamic cycle requirements. No geometric parameters need be specified. The following preliminary design data are determined: (1) the optimum flowpath geometry, within mechanical stress limits; (2) initial estimates of cascade blade shapes; (3) predictions of expected turbine performance. The method uses an inverse calculation technique whereby blade profiles are generated by designing channels to yield a specified velocity distribution on the two walls. Velocity distributions are then used to calculate the cascade loss parameters. Calculated blade shapes are used primarily to determine whether the assumed velocity loadings are physically realistic. Model verification is accomplished by comparison of predicted turbine geometry and performance with four existing single stage turbines.

An estimation of global solar p-mode frequencies from IRIS network data: 1989-1996

NASA Astrophysics Data System (ADS)

Serebryanskiy, A.; Ehgamberdiev, Sh.; Kholikov, Sh.; Fossat, E.; Gelly, B.; Schmider, F. X.; Grec, G.; Cacciani, A.; Palle, P. L.; Lazrek, M.; Hoeksema, J. T.

2001-06-01

The IRIS network has accumulated full disk helioseismological data since July 1989, i.e. a complete 11-year solar cycle. Since the last paper publishing a frequency list [A&A 317 (1997) L71], not only has the network acquired new data, but has also developed new co-operative programs with compatible instruments [Abstr. SOHO 6/GONG 98 Workshop (1998) 51], so that merging IRIS files with these co-operative program data sets has made possible the improvement of the overall duty cycle. This paper presents new estimations of low degree p-mode frequencies obtained from this IRIS++ data bank covering the period 1989-1996, as well as the variation of their main parameters along the total range of magnetic activity, from before the last maximum to the very minimum. A preliminary estimation of the peak profile asymmetries is also included.

Estimating Principal Effectiveness. Working Paper 32

ERIC Educational Resources Information Center

Branch, Gregory; Hanushek, Eric; Rivkin, Steven

2009-01-01

Much has been written about the importance of school leadership, but there is surprisingly little systematic evidence on this topic. This paper presents preliminary estimates of key elements of the market for school principals, employing rich panel data on principals from Texas State. The consideration of teacher movements across schools suggests…

A comparison of low back kinetic estimates obtained through posture matching, rigid link modeling and an EMG-assisted model.

PubMed

Parkinson, R J; Bezaire, M; Callaghan, J P

2011-07-01

This study examined errors introduced by a posture matching approach (3DMatch) relative to dynamic three-dimensional rigid link and EMG-assisted models. Eighty-eight lifting trials of various combinations of heights (floor, 0.67, 1.2 m), asymmetry (left, right and center) and mass (7.6 and 9.7 kg) were videotaped while spine postures, ground reaction forces, segment orientations and muscle activations were documented and used to estimate joint moments and forces (L5/S1). Posture matching over predicted peak and cumulative extension moment (p < 0.0001 for all variables). There was no difference between peak compression estimates obtained with posture matching or EMG-assisted approaches (p = 0.7987). Posture matching over predicted cumulative (p < 0.0001) compressive loading due to a bias in standing, however, individualized bias correction eliminated the differences. Therefore, posture matching provides a method to analyze industrial lifting exposures that will predict kinetic values similar to those of more sophisticated models, provided necessary corrections are applied. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Estimating Losses from Volcanic Ash in case of a Mt. Baekdu Eruption

NASA Astrophysics Data System (ADS)

Yu, Soonyoung; Yoon, Seong-Min; Kim, Sung-Wook; Choi, Eun-Kyeong

2014-05-01

We will present the preliminary result of economic losses in South Korea in case of a Mt. Baedu eruption. The Korean peninsula has Mt. Baekdu in North Korea, which will soon enter an active phase, according to volcanologists. The anticipated eruption will be explosive given the viscous and grassy silica-rich magma, and is expected to be one of the largest in recent millennia. We aim to assess the impacts of this eruption to South Korea and help government prepare for the volcanic disasters. In particular, the economic impact from volcanic ash is estimated given the distance from Mt. Baedu to South Korea. In order to scientifically estimate losses from volcanic ash, we need volcanic ash thickness, inventory database, and damage functions between ash thickness and damage ratios for each inventory item. We use the volcanic ash thickness calculated by other research groups in Korea, and they estimated the ash thickness for each eruption scenario using average wind fields. Damage functions are built using the historical damage data in the world, and inventory database is obtained from available digital maps in Korea. According to the preliminary results, the economic impact from volcanic ash is not significant because the ash is rarely deposited in South Korea under general weather conditions. However, the ash can impact human health and environment. Also worst case scenarios can have the significant economic impacts in Korea, and may result in global issues. Acknowledgement: This research was supported by a grant [NEMA-BAEKDUSAN-2012-1-3] from the Volcanic Disaster Preparedness Research Center sponsored by National Emergency Management Agency of Korea.

A GRASS GIS module to obtain an estimation of glacier behavior under climate change: A pilot study on Italian glacier

NASA Astrophysics Data System (ADS)

Strigaro, Daniele; Moretti, Massimiliano; Mattavelli, Matteo; Frigerio, Ivan; Amicis, Mattia De; Maggi, Valter

2016-09-01

The aim of this work is to integrate the Minimal Glacier Model in a Geographic Information System Python module in order to obtain spatial simulations of glacier retreat and to assess the future scenarios with a spatial representation. The Minimal Glacier Models are a simple yet effective way of estimating glacier response to climate fluctuations. This module can be useful for the scientific and glaciological community in order to evaluate glacier behavior, driven by climate forcing. The module, called r.glacio.model, is developed in a GRASS GIS (GRASS Development Team, 2016) environment using Python programming language combined with different libraries as GDAL, OGR, CSV, math, etc. The module is applied and validated on the Rutor glacier, a glacier in the south-western region of the Italian Alps. This glacier is very large in size and features rather regular and lively dynamics. The simulation is calibrated by reconstructing the 3-dimensional dynamics flow line and analyzing the difference between the simulated flow line length variations and the observed glacier fronts coming from ortophotos and DEMs. These simulations are driven by the past mass balance record. Afterwards, the future assessment is estimated by using climatic drivers provided by a set of General Circulation Models participating in the Climate Model Inter-comparison Project 5 effort. The approach devised in r.glacio.model can be applied to most alpine glaciers to obtain a first-order spatial representation of glacier behavior under climate change.

Preliminary Obtained Data from Borehole Geodetic Measurements in Marmara Region, Turkey

NASA Astrophysics Data System (ADS)

Ozener, H.; Aktug, B.; Karabulut, H.; Ergintav, S.; Dogru, A.; Yilmaz, O.; Turgut, B.; Ahiska, B.; Mencin, D.; Mattioli, G. S.

2014-12-01

Dense continuous GPS networks quantify the time-dependent deformation field of the earthquake cycle. However the strainmeters can capture signals with superior precision at local spatial scales, in particular in the short-period, from minutes to a month. Many relatively small-scale events (e.i. SSEs, creeps) have been successfully determined on the subduction zones. Istanbul located near the most active parts of the North Anatolian Fault (NAF) has been monitored by different observing techniques such as seismic networks and continuous/survey-mode GPS networks for decades. However, it is still essential to observe deformation in a broad range of temporal and spatial scales (from seismology to geodesy and to geology). Borehole strainmeters are very sensitive to deformation in the range of less than a month. In this study, we present a new project, financially and technically supported by Istanbul Development Agency (ISTKA) and UNAVCO, respectively, which includes the installation of two borehole strainmeters are being deployed in European side of Istanbul in Marmara Region. Since these instruments can also respond to non-tectonic processes, it is necessary to have more instruments to increase spatial coherence and to have additional sensors to detect and model noise (such as barometric pressure, tides, or precipitation). The introduced monitoring system will provide significant insight about the creeping phenomenon and the possible SSE to our understanding of seismic hazards in active zones and possible precursors. Our long term objective is to build a borehole monitoring system in the region. By integrating various data obtained from borehole observations, we expect to get a better understanding of dynamics in the western NAF. In this presentation, we introduce data and ongoing analysis obtained with strainmeters.

Preliminary Orbit and Differential Photometry of the Nearby Flare Star CR Dra

NASA Astrophysics Data System (ADS)

Tamazian, Vakhtang S.; Docobo, José A.; Balega, Yuri Y.; Melikian, Norair D.; Maximov, Alexander F.; Malogolovets, Evgeny V.

2008-09-01

New speckle measurements with the 6 m telescope of the Special Astrophysical Observatory (Russia) and the first preliminary orbit of the nearby flare star CR Dra (=Gl 616.2; WDS 16171+5516; BLA 3) with a period of 4.04 yr and a semimajor axis of 0farcs148 are reported. The Hipparcos parallax of 48.36 ± 1.16 mas (distance 20.7 pc) leads to an unusually large total mass of 1.8 M sun for a couple of red dwarfs. Meanwhile, the application of the Baize-Romani algorithm resulted in a mass sum of 1.00 M sun and a dynamical parallax of 58.43 mas (17.4 pc), which sensibly differs from that of Hipparcos. For the first time, we measured the photometric magnitude difference between the components (1.8 mag and 1.4 mag in the V and R bands, respectively) and obtained individual brightness estimates for each of them. Independently of the adopted parallax type, standard mass-luminosity relationships applied to individual components yield a total mass less than 1.2 M sun. This lends support to the use of a dynamical parallax, which is a more reliable distance estimate until a third body is discovered and/or our reported preliminary orbit is sensibly changed. CR Dra belongs to a handful of resolved short-period flare binaries, representing an excellent target to calculate a very accurate (or even definitive) orbit and a dynamical mass on a short time span. The available photometric data reveal no plausible correlation between flaring activity of CR Dra and linear distance between the components on the orbital path. Follow-up observations are needed for more detailed study of a possible relationship between dynamical and astrophysical properties of CR Dra and other similar systems.

Density Estimation with Mercer Kernels

NASA Technical Reports Server (NTRS)

Macready, William G.

2003-01-01

We present a new method for density estimation based on Mercer kernels. The density estimate can be understood as the density induced on a data manifold by a mixture of Gaussians fit in a feature space. As is usual, the feature space and data manifold are defined with any suitable positive-definite kernel function. We modify the standard EM algorithm for mixtures of Gaussians to infer the parameters of the density. One benefit of the approach is it's conceptual simplicity, and uniform applicability over many different types of data. Preliminary results are presented for a number of simple problems.

Preliminary tests of the electrostatic plasma accelerator

NASA Technical Reports Server (NTRS)

Aston, G.; Acker, T.

1990-01-01

This report describes the results of a program to verify an electrostatic plasma acceleration concept and to identify those parameters most important in optimizing an Electrostatic Plasma Accelerator (EPA) thruster based upon this thrust mechanism. Preliminary performance measurements of thrust, specific impulse and efficiency were obtained using a unique plasma exhaust momentum probe. Reliable EPA thruster operation was achieved using one power supply.

Heavy oil recovery process: Conceptual engineering of a downhole methanator and preliminary estimate of facilities cost for application to North Slope Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gondouin, M.

1991-10-31

The West Sak (Upper Cretaceous) sands, overlaying the Kuparuk field, would rank among the largest known oil fields in the US, but technical difficulties have so far prevented its commercial exploitation. Steam injection is the most successful and the most commonly-used method of heavy oil recovery, but its application to the West Sak presents major problems. Such difficulties may be overcome by using a novel approach, in which steam is generated downhole in a catalytic Methanator, from Syngas made at the surface from endothermic reactions (Table 1). The Methanator effluent, containing steam and soluble gases resulting from exothermic reactions (Tablemore » 1), is cyclically injected into the reservoir by means of a horizontal drainhole while hot produced fluids flow form a second drainhole into a central production tubing. The downhole reactor feed and BFW flow downward to two concentric tubings. The large-diameter casing required to house the downhole reactor assembly is filled above it with Arctic Pack mud, or crude oil, to further reduce heat leaks. A quantitative analysis of this production scheme for the West Sak required a preliminary engineering of the downhole and surface facilities and a tentative forecast of well production rates. The results, based on published information on the West Sak, have been used to estimate the cost of these facilities, per daily barrel of oil produced. A preliminary economic analysis and conclusions are presented together with an outline of future work. Economic and regulatory conditions which would make this approach viable are discussed. 28 figs.« less

Preliminary feasibility assessment for Earth-to-space electromagnetic (Railgun) launchers

NASA Technical Reports Server (NTRS)

Rice, E. E.; Miller, L. A.; Earhart, R. W.

1982-01-01

An Earth to space electromagnetic (railgun) launcher (ESRL) for launching material into space was studied. Potential ESRL applications were identified and initially assessed to formulate preliminary system requirements. The potential applications included nuclear waste disposal in space, Earth orbital applications, deep space probe launchers, atmospheric research, and boost of chemical rockets. The ESRL system concept consisted of two separate railgun launcher tubes (one at 20 deg from the horizontal for Earth orbital missions, the other vertical for solar system escape disposal missions) powered by a common power plant. Each 2040 m launcher tube is surrounded by 10,200 homopolar generator/inductor units to transmit the power to the walls. Projectile masses are 6500 kg for Earth orbital missions and 2055 kg for nuclear waste disposal missions. For the Earth orbital missions, the projectile requires a propulsion system, leaving an estimated payload mass of 650 kg. For the nuclear waste disposal in space mission, the high level waste mass was estimated at 250 kg. This preliminary assessment included technical, environmental, and economic analyses.

Variance Function Estimation. Revision.

DTIC Science & Technology

1987-03-01

UNLSIFIED RFOSR-TR-87-±112 F49620-85-C-O144 F/C 12/3 NL EEEEEEh LOUA28~ ~ L53 11uLoo MICROOP REOUINTS-’HR ------ N L E U INARF-% - IS %~1 %i % 0111...and 9 jointly. If 7,, 0. and are any preliminary estimators for 71, 6. and 3. define 71 and 6 to be the solutions of (4.1) N1 IN2 (7., ’ Td " ~ - / =0P

Comparison of estimates of left ventricular ejection fraction obtained from gated blood pool imaging, different software packages and cameras.

PubMed

Steyn, Rachelle; Boniaszczuk, John; Geldenhuys, Theodore

2014-01-01

To determine how two software packages, supplied by Siemens and Hermes, for processing gated blood pool (GBP) studies should be used in our department and whether the use of different cameras for the acquisition of raw data influences the results. The study had two components. For the first component, 200 studies were acquired on a General Electric (GE) camera and processed three times by three operators using the Siemens and Hermes software packages. For the second part, 200 studies were acquired on two different cameras (GE and Siemens). The matched pairs of raw data were processed by one operator using the Siemens and Hermes software packages. The Siemens method consistently gave estimates that were 4.3% higher than the Hermes method (p < 0.001). The differences were not associated with any particular level of left ventricular ejection fraction (LVEF). There was no difference in the estimates of LVEF obtained by the three operators (p = 0.1794). The reproducibility of estimates was good. In 95% of patients, using the Siemens method, the SD of the three estimates of LVEF by operator 1 was ≤ 1.7, operator 2 was ≤ 2.1 and operator 3 was ≤ 1.3. The corresponding values for the Hermes method were ≤ 2.5, ≤ 2.0 and ≤ 2.1. There was no difference in the results of matched pairs of data acquired on different cameras (p = 0.4933) CONCLUSION: Software packages for processing GBP studies are not interchangeable. The report should include the name and version of the software package used. Wherever possible, the same package should be used for serial studies. If this is not possible, the report should include the limits of agreement of the different packages. Data acquisition on different cameras did not influence the results.

Application of ANFIS to Phase Estimation for Multiple Phase Shift Keying

NASA Technical Reports Server (NTRS)

Drake, Jeffrey T.; Prasad, Nadipuram R.

2000-01-01

The paper discusses a novel use of Adaptive Neuro-Fuzzy Inference Systems (ANFIS) for estimating phase in Multiple Phase Shift Keying (M-PSK) modulation. A brief overview of communications phase estimation is provided. The modeling of both general open-loop, and closed-loop phase estimation schemes for M-PSK symbols with unknown structure are discussed. Preliminary performance results from simulation of the above schemes are presented.

Preliminary Results from the STARDUST Encounter with Wild 2 Comet obtained by the Dust Flux Monitor Instrument

NASA Astrophysics Data System (ADS)

Economou, T. E.; Tuzzolino, A. J.; Green, S. F.

On January 2nd, 2004, the Stardust spacecraft successfully encountered the Wild 2 comet. The Dust Flux Monitor Instrument (DFMI) provided quantitative measurements of dust particle fluxes and particle mass distribution throughout the entire flythrough. The DFMI consists of two different dust detector systems --- a polyvinylidene fluoride (PVDF) dust sensor unit (SU), which measures particles in the 10-11 to 10-4 mass, and a dual acoustic sensor system (DASS), which utilizes two piezoelectric accelerometers mounted on the first two layers of the spacecraft Whipple dust shield to measure the flux ofparticles with mass larger than 10-4 g. The DFMI on the stardust mission was designed, built and tested at the University of Chicago. The Open University provided the calibration and will perform the analysis of the data from the acoustic sensors. The DFMI instrument was turned on 15 minutes before the estimated closest approach. It started to detect the first dust particles just a few minutes before the closest approach with both types of the sensors in the instrument. As the S/C was departing the comet several more dust particle streams were encountered some 2-12 minutes after the closest approach. The time distribution of dust particles detected by DFMI is not uniform and they seem to come in closely spaced swarms of particles separated by many seconds with no events. The source of these particles is believed to be several of the jet streams that were observed in many of the images obtained by the navigation camera on the STARDUST spacecraft. Data flux rates and dust particle mass distribution are currently being evaluated and will be presented at the meeting. The instrument detected thousands of small particles and a few of them were large enough to even penetrate the first layer of the Whipple bumper shield. From the DFMI data it has been estimated that more than several thousands particles larger than 20 μ in diameter have been collected in the aerogel collector

On Obtaining Estimates of the Fraction of Missing Information from Full Information Maximum Likelihood

ERIC Educational Resources Information Center

Savalei, Victoria; Rhemtulla, Mijke

2012-01-01

Fraction of missing information [lambda][subscript j] is a useful measure of the impact of missing data on the quality of estimation of a particular parameter. This measure can be computed for all parameters in the model, and it communicates the relative loss of efficiency in the estimation of a particular parameter due to missing data. It has…

An Algorithm for Obtaining the Distribution of 1-Meter Lightning Channel Segment Altitudes for Application in Lightning NOx Production Estimation

NASA Technical Reports Server (NTRS)

Peterson, Harold; Koshak, William J.

2009-01-01

An algorithm has been developed to estimate the altitude distribution of one-meter lightning channel segments. The algorithm is required as part of a broader objective that involves improving the lightning NOx emission inventories of both regional air quality and global chemistry/climate models. The algorithm was tested and applied to VHF signals detected by the North Alabama Lightning Mapping Array (NALMA). The accuracy of the algorithm was characterized by comparing algorithm output to the plots of individual discharges whose lengths were computed by hand; VHF source amplitude thresholding and smoothing were applied to optimize results. Several thousands of lightning flashes within 120 km of the NALMA network centroid were gathered from all four seasons, and were analyzed by the algorithm. The mean, standard deviation, and median statistics were obtained for all the flashes, the ground flashes, and the cloud flashes. One-meter channel segment altitude distributions were also obtained for the different seasons.

Incident CTS in a large pooled cohort study: associations obtained by a Job Exposure Matrix versus associations obtained from observed exposures.

PubMed

Dale, Ann Marie; Ekenga, Christine C; Buckner-Petty, Skye; Merlino, Linda; Thiese, Matthew S; Bao, Stephen; Meyers, Alysha Rose; Harris-Adamson, Carisa; Kapellusch, Jay; Eisen, Ellen A; Gerr, Fred; Hegmann, Kurt T; Silverstein, Barbara; Garg, Arun; Rempel, David; Zeringue, Angelique; Evanoff, Bradley A

2018-03-29

There is growing use of a job exposure matrix (JEM) to provide exposure estimates in studies of work-related musculoskeletal disorders; few studies have examined the validity of such estimates, nor did compare associations obtained with a JEM with those obtained using other exposures. This study estimated upper extremity exposures using a JEM derived from a publicly available data set (Occupational Network, O*NET), and compared exposure-disease associations for incident carpal tunnel syndrome (CTS) with those obtained using observed physical exposure measures in a large prospective study. 2393 workers from several industries were followed for up to 2.8 years (5.5 person-years). Standard Occupational Classification (SOC) codes were assigned to the job at enrolment. SOC codes linked to physical exposures for forceful hand exertion and repetitive activities were extracted from O*NET. We used multivariable Cox proportional hazards regression models to describe exposure-disease associations for incident CTS for individually observed physical exposures and JEM exposures from O*NET. Both exposure methods found associations between incident CTS and exposures of force and repetition, with evidence of dose-response. Observed associations were similar across the two methods, with somewhat wider CIs for HRs calculated using the JEM method. Exposures estimated using a JEM provided similar exposure-disease associations for CTS when compared with associations obtained using the 'gold standard' method of individual observation. While JEMs have a number of limitations, in some studies they can provide useful exposure estimates in the absence of individual-level observed exposures. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

USCG Pollution Abatement Program : A Preliminary Study of Vessel and Boat Exhaust Emissions

DOT National Transportation Integrated Search

1971-11-30

A preliminary study of exhaust emissions from Coast Guard vessels and boats indicates that the Coast Guard fleet is an insignificant contributor to air pollution on a national and regional basis. Based upon fuel usage data, emission estimates by vess...

Hellenic Amateur Astronomy Association's activities: Preliminary results on Perseids 2010

NASA Astrophysics Data System (ADS)

Maravelias, G.

2011-01-01

Preliminary results on the Perseids 2010 are presented. Visual and video observations were obtained by the author and a first reduction of the visual data shows that a maximum of ZHR ~120 was reached during the night 12-13 of August 2010. Moreover, a video setup was tested (DMK camera and UFO Capture v2) and the results show that, under some limitations, valuable data can be obtained.

Quantitative assessment of the microbial risk of leafy greens from farm to consumption: preliminary framework, data, and risk estimates.

PubMed

Danyluk, Michelle D; Schaffner, Donald W

2011-05-01

This project was undertaken to relate what is known about the behavior of Escherichia coli O157:H7 under laboratory conditions and integrate this information to what is known regarding the 2006 E. coli O157:H7 spinach outbreak in the context of a quantitative microbial risk assessment. The risk model explicitly assumes that all contamination arises from exposure in the field. Extracted data, models, and user inputs were entered into an Excel spreadsheet, and the modeling software @RISK was used to perform Monte Carlo simulations. The model predicts that cut leafy greens that are temperature abused will support the growth of E. coli O157:H7, and populations of the organism may increase by as much a 1 log CFU/day under optimal temperature conditions. When the risk model used a starting level of -1 log CFU/g, with 0.1% of incoming servings contaminated, the predicted numbers of cells per serving were within the range of best available estimates of pathogen levels during the outbreak. The model predicts that levels in the field of -1 log CFU/g and 0.1% prevalence could have resulted in an outbreak approximately the size of the 2006 E. coli O157:H7 outbreak. This quantitative microbial risk assessment model represents a preliminary framework that identifies available data and provides initial risk estimates for pathogenic E. coli in leafy greens. Data gaps include retail storage times, correlations between storage time and temperature, determining the importance of E. coli O157:H7 in leafy greens lag time models, and validation of the importance of cross-contamination during the washing process.

Preliminary Genomic Characterization of Ten Hardwood Tree Species from Multiplexed Low Coverage Whole Genome Sequencing

PubMed Central

Staton, Margaret; Best, Teodora; Khodwekar, Sudhir; Owusu, Sandra; Xu, Tao; Xu, Yi; Jennings, Tara; Cronn, Richard; Arumuganathan, A. Kathiravetpilla; Coggeshall, Mark; Gailing, Oliver; Liang, Haiying; Romero-Severson, Jeanne; Schlarbaum, Scott; Carlson, John E.

2015-01-01

Forest health issues are on the rise in the United States, resulting from introduction of alien pests and diseases, coupled with abiotic stresses related to climate change. Increasingly, forest scientists are finding genetic/genomic resources valuable in addressing forest health issues. For a set of ten ecologically and economically important native hardwood tree species representing a broad phylogenetic spectrum, we used low coverage whole genome sequencing from multiplex Illumina paired ends to economically profile their genomic content. For six species, the genome content was further analyzed by flow cytometry in order to determine the nuclear genome size. Sequencing yielded a depth of 0.8X to 7.5X, from which in silico analysis yielded preliminary estimates of gene and repetitive sequence content in the genome for each species. Thousands of genomic SSRs were identified, with a clear predisposition toward dinucleotide repeats and AT-rich repeat motifs. Flanking primers were designed for SSR loci for all ten species, ranging from 891 loci in sugar maple to 18,167 in redbay. In summary, we have demonstrated that useful preliminary genome information including repeat content, gene content and useful SSR markers can be obtained at low cost and time input from a single lane of Illumina multiplex sequence. PMID:26698853

Preliminary report on tests of tensile specimens with a part-through surface notch for a filament wound graphite/epoxy material

NASA Technical Reports Server (NTRS)

Harris, C. E.; Morris, D. H.

1985-01-01

The behavior of tensile coupons with surface notches of various semi-elliptical shapes were evaluated for specimens obtained from a filament wound graphite/epoxy cylinder. The quasi-static test results, in some instances, are inadequate for defining complete trend curves and the interpretive analysis is considered to be preliminary. Specimens with very shallow notches were observed to be notch insensitive and the unnotched strength from these specimens was determined to be 54.97 Ksi. The failure strain of the laminate was found to be 1.328%. Specimens with deeper notches were sensitive to notch depth, notch aspect ratio, and specimen width. Using the unnotched strength of 54.97 Ksi and Poe's general toughness parameter, the fracture toughness was estimated to be 27.2 Ksi square root of In. Isotropic linear elastic fracture mechanics together with the estimated fracture toughness correctly predicted the influence of notch depth, aspect ratio, and specimen finitewidth.

Comparison of Sun-Induced Chlorophyll Fluorescence Estimates Obtained from Four Portable Field Spectroradiometers

NASA Technical Reports Server (NTRS)

Julitta, Tommaso; Corp, Lawrence A.; Rossini, Micol; Burkart, Andreas; Cogliati, Sergio; Davies, Neville; Hom, Milton; Mac Arthur, Alasdair; Middleton, Elizabeth M.; Rascher, Uwe;

Estimation of Enthalpy of Formation of Liquid Transition Metal Alloys: A Modified Prescription Based on Macroscopic Atom Model of Cohesion

NASA Astrophysics Data System (ADS)

Raju, Subramanian; Saibaba, Saroja

2016-09-01

The enthalpy of formation Δo H f is an important thermodynamic quantity, which sheds significant light on fundamental cohesive and structural characteristics of an alloy. However, being a difficult one to determine accurately through experiments, simple estimation procedures are often desirable. In the present study, a modified prescription for estimating Δo H f L of liquid transition metal alloys is outlined, based on the Macroscopic Atom Model of cohesion. This prescription relies on self-consistent estimation of liquid-specific model parameters, namely electronegativity ( ϕ L) and bonding electron density ( n b L ). Such unique identification is made through the use of well-established relationships connecting surface tension, compressibility, and molar volume of a metallic liquid with bonding charge density. The electronegativity is obtained through a consistent linear scaling procedure. The preliminary set of values for ϕ L and n b L , together with other auxiliary model parameters, is subsequently optimized to obtain a good numerical agreement between calculated and experimental values of Δo H f L for sixty liquid transition metal alloys. It is found that, with few exceptions, the use of liquid-specific model parameters in Macroscopic Atom Model yields a physically consistent methodology for reliable estimation of mixing enthalpies of liquid alloys.

Preliminary Results from the Application of Automated Adjoint Code Generation to CFL3D

NASA Technical Reports Server (NTRS)

Carle, Alan; Fagan, Mike; Green, Lawrence L.

1998-01-01

This report describes preliminary results obtained using an automated adjoint code generator for Fortran to augment a widely-used computational fluid dynamics flow solver to compute derivatives. These preliminary results with this augmented code suggest that, even in its infancy, the automated adjoint code generator can accurately and efficiently deliver derivatives for use in transonic Euler-based aerodynamic shape optimization problems with hundreds to thousands of independent design variables.

Papain wound dressings obtained from poly(vinyl alcohol)/calcium alginate blends as new pharmaceutical dosage form: Preparation and preliminary evaluation.

PubMed

Dutra, J A P; Carvalho, S G; Zampirolli, A C D; Daltoé, R D; Teixeira, R M; Careta, F P; Cotrim, M A P; Oréfice, R L; Villanova, J C O

2017-04-01

Transparent, soft, flexible, mechanically resistant films, which are ideal for use as wound dressings were prepared in the presence of 2% papain, a proteolytic enzyme that can play a role in the chemical debridement of the skin and can accelerate the healing process. The films, based on poly(vinyl alcohol):calcium alginate blends with increasing concentrations of polysaccharide (10, 20, and 30% v/v), were obtained by casting method. FTIR and DSC analyses were performed to assess the composition and miscibility of blends. Mechanical properties such as tensile strength, elasticity modulus, and elongation at breakpoint were evaluated. The influence of different concentrations of calcium alginate on physical attributes of films like wettability, swelling capacity and mechanical properties was determined. The stability of papain in the films was assessed indirectly by hemolytic activity assay employing direct contact method and confirmed by technique based on blood agar diffusion. Preliminary cytotoxicity was evaluated with the XTT method. The results showed that at the polymer concentrations tested, the blends were miscible. The increase in the content of the calcium alginate increased the wettability and swelling capacity of the films, which is desirable in wound dressings. On the other hand, mechanical resistance decreased without causing breakage of the films during the swelling tests. The hemolytic activity of the films was maintained during the studied period, suggesting the stability of papain in the proposed formulations. Cellular viability indicated that the films were non-toxic. The analysis of the results showed that it is possible to prepare interactive and bioactive wound dressing containing papain from blends of PVA and calcium alginate polymers. Copyright © 2016 Elsevier B.V. All rights reserved.

Benefits of dynamic mobility applications : preliminary estimates from the literature.

DOT National Transportation Integrated Search

2012-12-01

This white paper examines the available quantitative information on the potential mobility benefits of the connected vehicle Dynamic Mobility Applications (DMA). This work will be refined as more and better estimates of benefits from mobility applica...

Lead Coolant Test Facility Systems Design, Thermal Hydraulic Analysis and Cost Estimate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soli Khericha; Edwin Harvego; John Svoboda

2012-01-01

The Idaho National Laboratory prepared a preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed: (1) Develop and Demonstrate Feasibility of Submerged Heat Exchanger; (2) Develop and Demonstratemore » Open-lattice Flow in Electrically Heated Core; (3) Develop and Demonstrate Chemistry Control; (4) Demonstrate Safe Operation; and (5) Provision for Future Testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimate. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.« less

Lifetime prediction and reliability estimation methodology for Stirling-type pulse tube refrigerators by gaseous contamination accelerated degradation testing

NASA Astrophysics Data System (ADS)

Wan, Fubin; Tan, Yuanyuan; Jiang, Zhenhua; Chen, Xun; Wu, Yinong; Zhao, Peng

2017-12-01

Lifetime and reliability are the two performance parameters of premium importance for modern space Stirling-type pulse tube refrigerators (SPTRs), which are required to operate in excess of 10 years. Demonstration of these parameters provides a significant challenge. This paper proposes a lifetime prediction and reliability estimation method that utilizes accelerated degradation testing (ADT) for SPTRs related to gaseous contamination failure. The method was experimentally validated via three groups of gaseous contamination ADT. First, the performance degradation model based on mechanism of contamination failure and material outgassing characteristics of SPTRs was established. Next, a preliminary test was performed to determine whether the mechanism of contamination failure of the SPTRs during ADT is consistent with normal life testing. Subsequently, the experimental program of ADT was designed for SPTRs. Then, three groups of gaseous contamination ADT were performed at elevated ambient temperatures of 40 °C, 50 °C, and 60 °C, respectively and the estimated lifetimes of the SPTRs under normal condition were obtained through acceleration model (Arrhenius model). The results show good fitting of the degradation model with the experimental data. Finally, we obtained the reliability estimation of SPTRs through using the Weibull distribution. The proposed novel methodology enables us to take less than one year time to estimate the reliability of the SPTRs designed for more than 10 years.

Estimations of pollution emissions by the Moscow megapolis basing on in-situ measurements and optical remote sensing

NASA Astrophysics Data System (ADS)

Elansky, N.; Postylyakov, O.; Verevkin, Y.; Volobuev, L.; Ponomarev, N.

2017-11-01

By the present a large amount of data has been accumulated on direct measurements of the pollution and thermodynamic state of the atmosphere in the Moscow region, which was obtained at stations of Roshydromet, Mosecomonitoring, A.M.Obukhov Institute of Atmospheric Physics (OIAP), M.V. Lomonosov Moscow State University, NPO Typhoon, what allows estimating pollution emissions based on measurements and correcting existing emission inventories, which are evaluated mainly on indirect data connected with population density, fuel consumption, etc. Within the framework of the project, the whole volume of data on the concentration of ground contaminants CO, NOx, SO2, CH4, obtained at regularly operated Moscow Ecological Monitoring stations and at OIAP stations from 2005 to 2014, was systematized. Observation data on pollution concentrations are supplemented by measurements of their integral content in the atmospheric boundary layer, obtained by differential spectroscopy methods (MAX DOAS, ZDOAS) at stationary stations and by passing Moscow with DOAS-equipped car. The paper present preliminary estimates of pollution emissions in the Moscow region, obtained on the basis of the collected array of experimental data. The estimations of pollutant emissions from Moscow were obtained experimentally in a few ways: (1) on the basis of network observations of surface concentrations, (2) on the basis of measurements in the atmospheric layer 0-348 m at Ostankino TV tower, (3) on the basis of the integral pollutant (NO2) content in ABL obtained by DOAS technique from stationary stations, and (4) using a car with DOAS equipment traveling over the closed route around Moscow (for NO2). All experimental approaches yielded close values of pollution emissions for Moscow. Trends in emissions of CO, NOx, and CH4 are negative, and the trend of SO2 emission is positive from 2005 to 2014.

A Survey of Cost Estimating Methodologies for Distributed Spacecraft Missions

NASA Technical Reports Server (NTRS)

Foreman, Veronica L.; Le Moigne, Jacqueline; de Weck, Oliver L.

2016-01-01

Satellite constellations and Distributed Spacecraft Mission (DSM) architectures offer unique benefits to Earth observation scientists and unique challenges to cost estimators. The Cost and Risk (CR) module of the Tradespace Analysis Tool for Constellations (TAT-C) being developed by NASA Goddard seeks to address some of these challenges by providing a new approach to cost modeling, which aggregates existing Cost Estimating Relationships (CER) from respected sources, cost estimating best practices, and data from existing and proposed satellite designs. Cost estimation through this tool is approached from two perspectives: parametric cost estimating relationships and analogous cost estimation techniques. The dual approach utilized within the TAT-C CR module is intended to address prevailing concerns regarding early design stage cost estimates, and offer increased transparency and fidelity by offering two preliminary perspectives on mission cost. This work outlines the existing cost model, details assumptions built into the model, and explains what measures have been taken to address the particular challenges of constellation cost estimating. The risk estimation portion of the TAT-C CR module is still in development and will be presented in future work. The cost estimate produced by the CR module is not intended to be an exact mission valuation, but rather a comparative tool to assist in the exploration of the constellation design tradespace. Previous work has noted that estimating the cost of satellite constellations is difficult given that no comprehensive model for constellation cost estimation has yet been developed, and as such, quantitative assessment of multiple spacecraft missions has many remaining areas of uncertainty. By incorporating well-established CERs with preliminary approaches to approaching these uncertainties, the CR module offers more complete approach to constellation costing than has previously been available to mission architects or Earth

A Preliminary Report of National Estimates from the National Assessment of Educational Progress, 1992 Mathematics Assessment.

ERIC Educational Resources Information Center

Elliott, Emerson J., Comp.

This report contains preliminary results from the 1992 mathematics assessment by the National Assessment of Educational Progress (NAEP) of nationally representative samples of about 26,000 4th, 8th and 12th grade students in 1,500 public schools and private schools in 44 states; and compares data to findings from the 1990 NAEP mathematics tests.…

Evaluation and Preliminary Results of the New USNO PPS Timing Receiver

DTIC Science & Technology

2000-11-01

timing receiver, one may currently obtain raw pseudorange and carrier-phase data by periodically downloading such data from a flashcard . Several...preliminary experiments have been performed using data collected from the prototype TTR- 12 receivers’ flashcards and geodetic GPS carrier-phase techniques

Preliminary performances measured on a CMOS long linear array for space application

NASA Astrophysics Data System (ADS)

Renard, Christophe; Artinian, Armand; Dantes, Didier; Lepage, Gérald; Diels, Wim

2017-11-01

This paper presents the design and the preliminary performances of a CMOS linear array, resulting from collaboration between Alcatel Alenia Space and Cypress Semiconductor BVBA, which takes advantage of emerging potentialities of CMOS technologies. The design of the sensor is presented: it includes 8000 panchromatic pixels with up to 25 rows used in TDI mode, and 4 lines of 2000 pixels for multispectral imaging. Main system requirements and detector tradeoffs are recalled, and the preliminary test results obtained with a first generation prototype are summarized and compared with predicted performances.

On the estimation of physical height changes using GRACE satellite mission data - A case study of Central Europe

NASA Astrophysics Data System (ADS)

Godah, Walyeldeen; Szelachowska, Małgorzata; Krynski, Jan

2017-12-01

The dedicated gravity satellite missions, in particular the GRACE (Gravity Recovery and Climate Experiment) mission launched in 2002, provide unique data for studying temporal variations of mass distribution in the Earth's system, and thereby, the geometry and the gravity fi eld changes of the Earth. The main objective of this contribution is to estimate physical height (e.g. the orthometric/normal height) changes over Central Europe using GRACE satellite mission data as well as to analyse them and model over the selected study area. Physical height changes were estimated from temporal variations of height anomalies and vertical displacements of the Earth surface being determined over the investigated area. The release 5 (RL05) GRACE-based global geopotential models as well as load Love numbers from the Preliminary Reference Earth Model (PREM) were used as input data. Analysis of the estimated physical height changes and their modelling were performed using two methods: the seasonal decomposition method and the PCA/ EOF (Principal Component Analysis/Empirical Orthogonal Function) method and the differences obtained were discussed. The main fi ndings reveal that physical height changes over the selected study area reach up to 22.8 mm. The obtained physical height changes can be modelled with an accuracy of 1.4 mm using the seasonal decomposition method.

Preliminary Study of a Hybrid Helicon-ECR Plasma Source

NASA Astrophysics Data System (ADS)

M. Hala, A.; Oksuz, L.; Ximing, Zhu

2016-08-01

A new type of hybrid discharge is experimentally investigated in this work. A helicon source and an electron cyclotron resonance (ECR) source were combined to produce plasma. As a preliminary study of this type of plasma, the optical emission spectroscopy (OES) method was used to obtain values of electron temperature and density under a series of typical conditions. Generally, it was observed that the electron temperature decreases and the electron density increases as the pressure increased. When increasing the applied power at a certain pressure, the average electron density at certain positions in the discharge does not increase significantly possibly due to the high degree of neutral depletion. Electron temperature increased with power in the hybrid mode. Possible mechanisms of these preliminary observations are discussed.

Preliminary SPE Phase II Far Field Ground Motion Estimates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steedman, David W.

2014-03-06

Phase II of the Source Physics Experiment (SPE) program will be conducted in alluvium. Several candidate sites were identified. These include existing large diameter borehole U1e. One criterion for acceptance is expected far field ground motion. In June 2013 we were requested to estimate peak response 2 km from the borehole due to the largest planned SPE Phase II experiment: a contained 50- Ton event. The cube-root scaled range for this event is 5423 m/KT 1/3. The generally accepted first order estimate of ground motions from an explosive event is to refer to the standard data base for explosive eventsmore » (Perrett and Bass, 1975). This reference is a compilation and analysis of ground motion data from numerous nuclear and chemical explosive events from Nevada National Security Site (formerly the Nevada Test Site, or NTS) and other locations. The data were compiled and analyzed for various geologic settings including dry alluvium, which we believe is an accurate descriptor for the SPE Phase II setting. The Perrett and Bass plots of peak velocity and peak yield-scaled displacement, both vs. yield-scaled range, are provided here. Their analysis of both variables resulted in bi-linear fits: a close-in non-linear regime and a more distant linear regime.« less

Preliminary studies on the planetary entry to Jupiter by aerocapture technique

NASA Astrophysics Data System (ADS)

Aso, Shigeru; Yasaka, Tetsuo; Hirayama, Hiroshi; Poetro, Ridanto Eko; Hatta, Shinji

2006-10-01

Preliminary studies on the planetary entry to Jupiter by aerocapture technique are studied in order to complete technological challenges to deliver scientific probe with low cost and smaller mass of the spacecraft to Jupiter. Jupiter aerocapture corridor determination based on maximum deceleration limit of 5g (lower corridor) and aerocapture capability (upper corridor) at Jupiter are carefully considered and calculated. The results show about 1700 m/s of saving velocity due to aerocapture could be possible in some cases for the spacecraft to be captured by Jovian gravitational field. However, the results also show that Jovian aerocapture is not available in some cases. Hence, careful selection is needed to realize Jovian aerocapture. Also the numerical simulation of aerodynamic heating to the spacecraft has been conducted. DSMC method is used for the simulation of flow fields around the spacecraft. The transient changes of drag due to Jovian atmosphere and total heat loads to the spacecraft are obtained. The results show that the estimated heat loads could be within allowable amount heat load when some ablation heat shield technique is applied.

Preliminary studies on the planetary entry to Jupiter by aerocapture technique

NASA Astrophysics Data System (ADS)

Aso, Shigeru; Yasaka, Tetsuo; Hirayama, Hiroshi; Eko Poetro, Ridanto; Hatta, Shinji

2003-11-01

Preliminary studies on the planetary entry to Jupiter by aerocapture technique are studied in order to complete technological challenges to deliver scientific probe with low cost and smaller mass of the spacecraft to Jupiter. Jupiter aerocapture corridor determination based on maximum deceleration limit of 5g (lower corridor) and aerocapture capability (upper corridor) at Jupiter are carefully considered and calculated. The results show about 1700 m/s of saving velocity due to aerocapture could be possible in some cases for the spacecraft to be captured by Jovian gravitational field. However, the results also show that Jovian aerocapture is not available in some cases. Hence, careful selection is needed to realise Jovian aerocapture. Also the numerical simulation of aerodynamic heating to the spacecraft has been conducted. DSMC method is used for the simulation of flow fields around the spacecraft. The transient changes of drag due to Jovian atmosphere and total heat loads to the spacecraft are obtained. The results show the estimated heat loads could be within allowable amount heat load when some ablation heat shield technique is applied.

Output-feedback control of combined sewer networks through receding horizon control with moving horizon estimation

NASA Astrophysics Data System (ADS)

Joseph-Duran, Bernat; Ocampo-Martinez, Carlos; Cembrano, Gabriela

2015-10-01

An output-feedback control strategy for pollution mitigation in combined sewer networks is presented. The proposed strategy provides means to apply model-based predictive control to large-scale sewer networks, in-spite of the lack of measurements at most of the network sewers. In previous works, the authors presented a hybrid linear control-oriented model for sewer networks together with the formulation of Optimal Control Problems (OCP) and State Estimation Problems (SEP). By iteratively solving these problems, preliminary Receding Horizon Control with Moving Horizon Estimation (RHC/MHE) results, based on flow measurements, were also obtained. In this work, the RHC/MHE algorithm has been extended to take into account both flow and water level measurements and the resulting control loop has been extensively simulated to assess the system performance according different measurement availability scenarios and rain events. All simulations have been carried out using a detailed physically based model of a real case-study network as virtual reality.

Preliminary GRS Measurement of Chlorine Distribution on Surface of Mars

NASA Astrophysics Data System (ADS)

Keller, J. M.; Boynton, W. V.; Taylor, G. J.; Hamara, D.; Janes, D. M.; Kerry, K.

2003-12-01

Ongoing measurements with the Gamma Ray Spectrometer (GRS) aboard Mars Odyssey provide preliminary detection of chlorine at the surface of Mars. Summing all data since boom deployment and using a forward calculation model, we estimate values for chlorine concentration at 5° resolution. Rebinning this data and smoothing with a 15-degree-radius boxcar filter reveal regions of noticeable chlorine enrichment at scales larger than the original 5° resolution and allow for preliminary comparison with previous Mars datasets. Analyzing chlorine concentrations within 30 degrees of the equator, we find a negative correlation with thermal inertia (R2=0.55) and positive correlation with albedo (R2=0.52), indicating that chlorine is associated with fine, non-rock surface materials. Although possibly a smoothing artifact, the spatial correlation is more noticeable in the region covering Tharsis and Amazonis than around Arabia and Elysium. Additionally, a noticeable region of chlorine enrichment appears west of Tharsis Montes ( ˜0 to 20N, ˜110 to 150W) and chlorine concentration is estimated to vary in the equatorial region by over a factor of two. A simplified two-component model involving chlorine-poor rocks and a homogenous chlorine-rich fine material requires rock abundance to vary from zero to over 50%, a result inconsistent with previous measurements and models. In addition to variations in rock composition and distribution, substantial variations in chlorine content of various types of fine materials including dust, sand, and duricrust appear important in explaining this preliminary observation. Surprisingly, visual comparison of surface units mapped by Christensen and Moore (1992) does not show enrichment in chlorine associated with regions of indurated surfaces, where cementation has been proposed. Rather, Tharsis, a region of active deposition with proposed mantling of 0.1 to 2 meters of recent dust (Christensen 1986), shows the greatest chlorine signal. In light of

Estimating secular velocities from GPS data contaminated by postseismic motion at sites with limited pre-earthquake data

NASA Astrophysics Data System (ADS)

Murray, J. R.; Svarc, J. L.

2016-12-01

Constant secular velocities estimated from Global Positioning System (GPS)-derived position time series are a central input for modeling interseismic deformation in seismically active regions. Both postseismic motion and temporally correlated noise produce long-period signals that are difficult to separate from secular motion and can bias velocity estimates. For GPS sites installed post-earthquake it is especially challenging to uniquely estimate velocities and postseismic signals and to determine when the postseismic transient has decayed sufficiently to enable use of subsequent data for estimating secular rates. Within 60 km of the 2003 M6.5 San Simeon and 2004 M6 Parkfield earthquakes in California, 16 continuous GPS sites (group 1) were established prior to mid-2001, and 52 stations (group 2) were installed following the events. We use group 1 data to investigate how early in the post-earthquake time period one may reliably begin using group 2 data to estimate velocities. For each group 1 time series, we obtain eight velocity estimates using observation time windows with successively later start dates (2006 - 2013) and a parameterization that includes constant velocity, annual, and semi-annual terms but no postseismic decay. We compare these to velocities estimated using only pre-San Simeon data to find when the pre- and post-earthquake velocities match within uncertainties. To obtain realistic velocity uncertainties, for each time series we optimize a temporally correlated noise model consisting of white, flicker, random walk, and, in some cases, band-pass filtered noise contributions. Preliminary results suggest velocities can be reliably estimated using data from 2011 to the present. Ongoing work will assess velocity bias as a function of epicentral distance and length of post-earthquake time series as well as explore spatio-temporal filtering of detrended group 1 time series to provide empirical corrections for postseismic motion in group 2 time series.

Sampling Errors of SSM/I and TRMM Rainfall Averages: Comparison with Error Estimates from Surface Data and a Sample Model

NASA Technical Reports Server (NTRS)

Bell, Thomas L.; Kundu, Prasun K.; Kummerow, Christian D.; Einaudi, Franco (Technical Monitor)

2000-01-01

Quantitative use of satellite-derived maps of monthly rainfall requires some measure of the accuracy of the satellite estimates. The rainfall estimate for a given map grid box is subject to both remote-sensing error and, in the case of low-orbiting satellites, sampling error due to the limited number of observations of the grid box provided by the satellite. A simple model of rain behavior predicts that Root-mean-square (RMS) random error in grid-box averages should depend in a simple way on the local average rain rate, and the predicted behavior has been seen in simulations using surface rain-gauge and radar data. This relationship was examined using satellite SSM/I data obtained over the western equatorial Pacific during TOGA COARE. RMS error inferred directly from SSM/I rainfall estimates was found to be larger than predicted from surface data, and to depend less on local rain rate than was predicted. Preliminary examination of TRMM microwave estimates shows better agreement with surface data. A simple method of estimating rms error in satellite rainfall estimates is suggested, based on quantities that can be directly computed from the satellite data.

Estimating impervious cover and riparian zone condition in New England watersheds

EPA Science Inventory

Under EPA’s Green Infrastructure Initiative, research activities are underway to evaluate the effectiveness of green infrastructure in mitigating the effects of urbanization and stormwater impacts on stream biota and habitat. Preliminary analyses, using impervious cover estimate...

The area-time-integral technique to estimate convective rain volumes over areas applied to satellite data - A preliminary investigation

NASA Technical Reports Server (NTRS)

Doneaud, Andre A.; Miller, James R., Jr.; Johnson, L. Ronald; Vonder Haar, Thomas H.; Laybe, Patrick

1987-01-01

The use of the area-time-integral (ATI) technique, based only on satellite data, to estimate convective rain volume over a moving target is examined. The technique is based on the correlation between the radar echo area coverage integrated over the lifetime of the storm and the radar estimated rain volume. The processing of the GOES and radar data collected in 1981 is described. The radar and satellite parameters for six convective clusters from storm events occurring on June 12 and July 2, 1981 are analyzed and compared in terms of time steps and cluster lifetimes. Rain volume is calculated by first using the regression analysis to generate the regression equation used to obtain the ATI; the ATI versus rain volume relation is then employed to compute rain volume. The data reveal that the ATI technique using satellite data is applicable to the calculation of rain volume.

75 FR 26716 - Seamless Refined Copper Pipe and Tube from the People's Republic of China: Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-12

...The Department of Commerce (the ``Department'') has preliminarily determined that seamless refined copper pipe and tube (``copper pipe and tube'') from the People's Republic of China (``PRC'') is being, or is likely to be, sold in the United States at less than fair value (``LTFV''), as provided in section 733 of the Tariff Act of 1930, as amended (the ``Act''). The estimated dumping margins are shown in the ``Preliminary Determination'' section of this notice. Interested parties are invited to comment on the preliminary determination.

Preliminary Evaluation of Method to Monitor Landfills Resilience against Methane Emission

NASA Astrophysics Data System (ADS)

Chusna, Noor Amalia; Maryono, Maryono

2018-02-01

Methane emission from landfill sites contribute to global warming and un-proper methane treatment can pose an explosion hazard. Stakeholder and government in the cities in Indonesia been found significant difficulties to monitor the resilience of landfill from methane emission. Moreover, the management of methane gas has always been a challenging issue for long waste management service and operations. Landfills are a significant contributor to anthropogenic methane emissions. This study conducted preliminary evaluation of method to manage methane gas emission by assessing LandGem and IPCC method. From the preliminary evaluation, this study found that the IPCC method is based on the availability of current and historical country specific data regarding the waste disposed of in landfills while from the LandGEM method is an automated tool for estimating emission rates for total landfill gas this method account total gas of methane, carbon dioxide and other. The method can be used either with specific data to estimate emissions in the site or default parameters if no site-specific data are available. Both of method could be utilize to monitor the methane emission from landfill site in cities of Central Java.

Preliminary Validation of a New Clinical Tool for Identifying Problem Video Game Playing

ERIC Educational Resources Information Center

King, Daniel Luke; Delfabbro, Paul H.; Zajac, Ian T.

2011-01-01

Research has estimated that between 6 to 13% of individuals who play video games do so excessively. However, the methods and definitions used to identify "problem" video game players often vary considerably. This research presents preliminary validation data for a new measure of problematic video game play called the Problem Video Game…

Estimate of neutrons event-by-event in DREAM

NASA Astrophysics Data System (ADS)

Hauptman, John; DREAM Collaboration

2009-04-01

We have measured the contribution of neutrons to hadronic showers in the DREAM module event-by-event as a means to estimate the event-by-event fluctuations in binding energy losses by hadrons as they break up nuclei of the Cu absorber. We make a preliminary assessment of the consequences for hadronic energy resolution in dual-readout calorimeters.

Molecular-based estimate of species number, phylogenetic relationships and divergence times for the genus Stenotaenia (Chilopoda, Geophilomorpha) in the Italian region

PubMed Central

Del Latte, Laura; Bortolin, Francesca; Rota-Stabelli, Omar; Fusco, Giuseppe; Bonato, Lucio

2015-01-01

Abstract Stenotaenia is one of the largest and most widespread genera of geophilid centipedes in the Western Palearctic, with a very uniform morphology and about fifteen species provisionally recognized. For a better understanding of Stenotaenia species-level taxonomy, we have explored the possibility of using molecular data. As a preliminary assay, we sampled twelve populations, mainly from the Italian region, and analyzed partial sequences of the two genes COI and 28S. We employed a DNA-barcoding approach, complemented by a phylogenetic analysis coupled with divergence time estimation. Assuming a barcoding gap of 10–16% K2P pairwise distances, we found evidence for the presence of at least six Stenotaenia species in the Italian region, which started diverging about 50 million years ago, only partially matching with previously recognized species. We found that small-sized oligopodous species belong to a single clade that originated about 33 million years ago, and obtained some preliminary evidence of the related genus Tuoba being nested within Stenotaenia. PMID:26257533

The influence of random element displacement on DOA estimates obtained with (Khatri-Rao-)root-MUSIC.

PubMed

Inghelbrecht, Veronique; Verhaevert, Jo; van Hecke, Tanja; Rogier, Hendrik

2014-11-11

Although a wide range of direction of arrival (DOA) estimation algorithms has been described for a diverse range of array configurations, no specific stochastic analysis framework has been established to assess the probability density function of the error on DOA estimates due to random errors in the array geometry. Therefore, we propose a stochastic collocation method that relies on a generalized polynomial chaos expansion to connect the statistical distribution of random position errors to the resulting distribution of the DOA estimates. We apply this technique to the conventional root-MUSIC and the Khatri-Rao-root-MUSIC methods. According to Monte-Carlo simulations, this novel approach yields a speedup by a factor of more than 100 in terms of CPU-time for a one-dimensional case and by a factor of 56 for a two-dimensional case.

Agricultural Decision Support Through Robust Assimilation of Satellite Derived Soil Moisture Estimates

NASA Astrophysics Data System (ADS)

Mishra, V.; Cruise, J.; Mecikalski, J. R.

2012-12-01

Soil Moisture is a key component in the hydrological process, affects surface and boundary layer energy fluxes and is the driving factor in agricultural production. Multiple in situ soil moisture measuring instruments such as Time-domain Reflectrometry (TDR), Nuclear Probes etc. are in use along with remote sensing methods like Active and Passive Microwave (PM) sensors. In situ measurements, despite being more accurate, can only be obtained at discrete points over small spatial scales. Remote sensing estimates, on the other hand, can be obtained over larger spatial domains with varying spatial and temporal resolutions. Soil moisture profiles derived from satellite based thermal infrared (TIR) imagery can overcome many of the problems associated with laborious in-situ observations over large spatial domains. An area where soil moisture observation and assimilation is receiving increasing attention is agricultural crop modeling. This study revolves around the use of the Decision Support System for Agrotechnology Transfer (DSSAT) crop model to simulate corn yields under various forcing scenarios. First, the model was run and calibrated using observed precipitation and model generated soil moisture dynamics. Next, the modeled soil moisture was updated using estimates derived from satellite based TIR imagery and the Atmospheric Land Exchange Inverse (ALEXI) model. We selected three climatically different locations to test the concept. Test Locations were selected to represent varied climatology. Bell Mina, Alabama - South Eastern United States, representing humid subtropical climate. Nabb, Indiana - Mid Western United States, representing humid continental climate. Lubbok, Texas - Southern United States, representing semiarid steppe climate. A temporal (2000-2009) correlation analysis of the soil moisture values from both DSSAT and ALEXI were performed and validated against the Land Information System (LIS) soil moisture dataset. The results clearly show strong

Preliminary risk benefit assessment for nuclear waste disposal in space

NASA Technical Reports Server (NTRS)

Rice, E. E.; Denning, R. S.; Friedlander, A. L.; Priest, C. C.

1982-01-01

This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.

Airport Surface Delays and Causes: A Preliminary Analysis

NASA Technical Reports Server (NTRS)

Chin, David K.; Goldberg, Jay; Tang, Tammy

1997-01-01

This report summarizes FAA Program Analysis and Operations Research Service (ASD-400)/Lockheed Martin activities and findings related to airport surface delays and causes, in support of NASA Langley Research Center's Terminal Area Productivity (TAP) Program. The activities described in this report were initiated in June 1995. A preliminary report was published on September 30, 1995. The final report incorporates data collection forms filled out by traffic managers, other FAA staff, and an airline for the New York City area, some updates, data previously requested from various sources to support this analysis, and further quantification and documentation than in the preliminary report. This final report is based on data available as of April 12, 1996. This report incorporates data obtained from review and analysis of data bases and literature, discussions/interviews with engineers, air-traffic staff, other FAA technical personnel, and airline staff, site visits, and a survey on surface delays and causes. It includes analysis of delay statistics; preliminary findings and conclusions on surface movement, surface delay sources and causes, runway occupancy time (ROT), and airport characteristics impacting surface operations and delays; and site-specific data on the New York City area airports, which are the focus airports for this report.

Experience from a multicentre stroke register: a preliminary report

PubMed Central

Hatano, S.

1976-01-01

In collaboration with 15 centres in 10 countries of Africa, Asia, and Europe, WHO started a pilot study of a community-based stroke register, with standardized methods. Preliminary data were obtained on 6395 new cases of stroke in defined study communities, from May 1971 to September 1974. Information on incidence rates, clinical profiles, diagnosis, management, and course and prognosis for these patients is given. PMID:1088404

Cycles till failure of silver-zinc cells with competing failure modes - Preliminary data analysis

NASA Technical Reports Server (NTRS)

Sidik, S. M.; Leibecki, H. F.; Bozek, J. M.

1980-01-01

The data analysis of cycles to failure of silver-zinc electrochemical cells with competing failure modes is presented. The test ran 129 cells through charge-discharge cycles until failure; preliminary data analysis consisted of response surface estimate of life. Batteries fail through low voltage condition and an internal shorting condition; a competing failure modes analysis was made using maximum likelihood estimation for the extreme value life distribution. Extensive residual plotting and probability plotting were used to verify data quality and selection of model.

Cascade Optimization Strategy with Neural Network and Regression Approximations Demonstrated on a Preliminary Aircraft Engine Design

NASA Technical Reports Server (NTRS)

Hopkins, Dale A.; Patnaik, Surya N.

2000-01-01

A preliminary aircraft engine design methodology is being developed that utilizes a cascade optimization strategy together with neural network and regression approximation methods. The cascade strategy employs different optimization algorithms in a specified sequence. The neural network and regression methods are used to approximate solutions obtained from the NASA Engine Performance Program (NEPP), which implements engine thermodynamic cycle and performance analysis models. The new methodology is proving to be more robust and computationally efficient than the conventional optimization approach of using a single optimization algorithm with direct reanalysis. The methodology has been demonstrated on a preliminary design problem for a novel subsonic turbofan engine concept that incorporates a wave rotor as a cycle-topping device. Computations of maximum thrust were obtained for a specific design point in the engine mission profile. The results (depicted in the figure) show a significant improvement in the maximum thrust obtained using the new methodology in comparison to benchmark solutions obtained using NEPP in a manual design mode.

An Account of Preliminary Landslide Damage and Losses Resulting from the February 28, 2001, Nisqually, Washington, Earthquake

USGS Publications Warehouse

Highland, Lynn M.

2003-01-01

The February 28, 2001, Nisqually, Washington, earthquake (Mw = 6.8) damaged an area of the northwestern United States that previously experienced two major historical earthquakes, in 1949 and in 1965. Preliminary estimates of direct monetary losses from damage due to earthquake-induced landslides is approximately $34.3 million. However, this figure does not include costs from damages to the elevated portion of the Alaskan Way Viaduct, a major highway through downtown Seattle, Washington that will be repaired or rebuilt, depending on the future decision of local and state authorities. There is much debate as to the cause of the damage to this viaduct with evaluations of cause ranging from earthquake shaking and liquefaction to lateral spreading to a combination of these effects. If the viaduct is included in the costs, the losses increase to $500+ million (if it is repaired) or to more than $1+ billion (if it is replaced). Preliminary estimate of losses due to all causes of earthquake damage is approximately $2 billion, which includes temporary repairs to the Alaskan Way Viaduct. These preliminary dollar figures will no doubt increase when plans and decisions regarding the Viaduct are completed.

Preliminary bioelectrical impedance analysis (BIA) equation for body composition assessment in young females from Colombia

NASA Astrophysics Data System (ADS)

Caicedo-Eraso, J. C.; González-Correa, C. H.; González-Correa, C. A.

2013-04-01

A previous study showed that reported BIA equations for body composition are not suitable for Colombian population. The purpose of this study was to develop and validate a preliminary BIA equation for body composition assessment in young females from Colombia, using hydrodensitometry as reference method. A sample of 30 young females was evaluated. Inclusion and exclusion criteria were defined to minimize the variability of BIA. Height, weight, BIA, residual lung volume (RV) and underwater weight (UWW) were measured. A preliminary BIA equation was developed (r2 = 0.72, SEE = 2.48 kg) by stepwise multiple regression with fat-free mass (FFM) as dependent variable and weight, height and impedance measurements as independent variables. The quality of regression was evaluated and a cross-validation against 50% of sample confirmed that results obtained with the preliminary BIA equation is interchangeable with results obtained with hydrodensitometry (r2 = 0.84, SEE = 2.62 kg). The preliminary BIA equation can be used for body composition assessment in young females from Colombia until a definitive equation is developed. The next step will be increasing the sample, including a second reference method, as deuterium oxide dilution (D2O), and using multi-frequency BIA (MF-BIA). It would also be desirable to develop equations for males and other ethnic groups in Colombia.

Towards local estimation of emphysema progression using image registration

NASA Astrophysics Data System (ADS)

Staring, M.; Bakker, M. E.; Shamonin, D. P.; Stolk, J.; Reiber, J. H. C.; Stoel, B. C.

2009-02-01

Progression measurement of emphysema is required to evaluate the health condition of a patient and the effect of drugs. To locally estimate progression we use image registration, which allows for volume correction using the determinant of the Jacobian of the transformation. We introduce an adaptation of the so-called sponge model that circumvents its constant-mass assumption. Preliminary results from CT scans of a lung phantom and from CT data sets of three patients suggest that image registration may be a suitable method to locally estimate emphysema progression.

Index to Estimate the Efficiency of an Ophthalmic Practice.

PubMed

Chen, Andrew; Kim, Eun Ah; Aigner, Dennis J; Afifi, Abdelmonem; Caprioli, Joseph

2015-08-01

A metric of efficiency, a function of the ratio of quality to cost per patient, will allow the health care system to better measure the impact of specific reforms and compare the effectiveness of each. To develop and evaluate an efficiency index that estimates the performance of an ophthalmologist's practice as a function of cost, number of patients receiving care, and quality of care. Retrospective review of 36 ophthalmology subspecialty practices from October 2011 to September 2012 at a university-based eye institute. The efficiency index (E) was defined as a function of adjusted number of patients (N(a)), total practice adjusted costs (C(a)), and a preliminary measure of quality (Q). Constant b limits E between 0 and 1. Constant y modifies the influence of Q on E. Relative value units and geographic cost indices determined by the Centers for Medicare and Medicaid for 2012 were used to calculate adjusted costs. The efficiency index is expressed as the following: E = b(N(a)/C(a))Q(y). Independent, masked auditors reviewed 20 random patient medical records for each practice and filled out 3 questionnaires to obtain a process-based quality measure. The adjusted number of patients, adjusted costs, quality, and efficiency index were calculated for 36 ophthalmology subspecialties. The median adjusted number of patients was 5516 (interquartile range, 3450-11,863), the median adjusted cost was 1.34 (interquartile range, 0.99-1.96), the median quality was 0.89 (interquartile range, 0.79-0.91), and the median value of the efficiency index was 0.26 (interquartile range, 0.08-0.42). The described efficiency index is a metric that provides a broad overview of performance for a variety of ophthalmology specialties as estimated by resources used and a preliminary measure of quality of care provided. The results of the efficiency index could be used in future investigations to determine its sensitivity to detect the impact of interventions on a practice such as training

Deproteinated palm kernel cake-derived oligosaccharides: A preliminary study

NASA Astrophysics Data System (ADS)

Fan, Suet Pin; Chia, Chin Hua; Fang, Zhen; Zakaria, Sarani; Chee, Kah Leong

2014-09-01

Preliminary study on microwave-assisted hydrolysis of deproteinated palm kernel cake (DPKC) to produce oligosaccharides using succinic acid was performed. Three important factors, i.e., temperature, acid concentration and reaction time, were selected to carry out the hydrolysis processes. Results showed that the highest yield of DPKC-derived oligosaccharides can be obtained at a parameter 170 °C, 0.2 N SA and 20 min of reaction time.

Cellulose fibers obtained by organosolv process from date palm rachis (Phoenix dactylifera L.)

NASA Astrophysics Data System (ADS)

Ammar, H.; Abid, M.; Abid, S.

2012-02-01

In this preliminary study, the chemical composition of Tunisian DPR was established and discussed. The main characteristic of this agri-residue was its high lignin content in comparison with that of alfa plant. CIMV process was used to selectively separate cellulose fibres, hemicelluloses and lignin at atmospheric pressure. The obtained unbleached pulp was analysed in accordance with Kappa index and degree of polymerisation and then bleached by treating successively with peroxyacids and hydrogen peroxide in basic media.

Breast ultrasound tomography with two parallel transducer arrays: preliminary clinical results

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Shin, Junseob; Chen, Ting; Lin, Youzuo; Intrator, Miranda; Hanson, Kenneth; Epstein, Katherine; Sandoval, Daniel; Williamson, Michael

2015-03-01

Ultrasound tomography has great potential to provide quantitative estimations of physical properties of breast tumors for accurate characterization of breast cancer. We design and manufacture a new synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays. The distance of these two transducer arrays is adjustable for scanning breasts with different sizes. The ultrasound transducer arrays are translated vertically to scan the entire breast slice by slice and acquires ultrasound transmission and reflection data for whole-breast ultrasound imaging and tomographic reconstructions. We use the system to acquire patient data at the University of New Mexico Hospital for clinical studies. We present some preliminary imaging results of in vivo patient ultrasound data. Our preliminary clinical imaging results show promising of our breast ultrasound tomography system with two parallel transducer arrays for breast cancer imaging and characterization.

77 FR 58988 - Shearwater Design, Inc.; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-25

... application for a successive preliminary permit, pursuant to section 4(f) of the Federal Power Act (FPA), proposing to study the feasibility of the Homeowner Tidal Power Electric Generation Project to be located in.... The proposed project would consist of: (1) 10 hydrokinetic turbine units with an estimated total...

A preliminary estimate of geoid-induced variations in repeat orbit satellite altimeter observations

NASA Technical Reports Server (NTRS)

Brenner, Anita C.; Beckley, B. D.; Koblinsky, C. J.

1990-01-01

Altimeter satellites are often maintained in a repeating orbit to facilitate the separation of sea-height variations from the geoid. However, atmospheric drag and solar radiation pressure cause a satellite orbit to drift. For Geosat this drift causes the ground track to vary by + or - 1 km about the nominal repeat path. This misalignment leads to an error in the estimates of sea surface height variations because of the local slope in the geoid. This error has been estimated globally for the Geosat Exact Repeat Mission using a mean sea surface constructed from Geos 3 and Seasat altimeter data. Over most of the ocean the geoid gradient is small, and the repeat-track misalignment leads to errors of only 1 to 2 cm. However, in the vicinity of trenches, continental shelves, islands, and seamounts, errors can exceed 20 cm. The estimated error is compared with direct estimates from Geosat altimetry, and a strong correlation is found in the vicinity of the Tonga and Aleutian trenches. This correlation increases as the orbit error is reduced because of the increased signal-to-noise ratio.

Preliminary national rail plan.

DOT National Transportation Integrated Search

2009-10-15

The Passenger Rail Investment and Improvement Act of 2008 (PRIIA) directed the Administrator of the Federal Railroad Administration (FRA) to develop a Preliminary National Rail Plan (PNRP or Preliminary Plan) to address the rail needs of the Nation. ...

Patient-Specific Pharmacokinetic Parameter Estimation on Dynamic Contrast-Enhanced MRI of Prostate: Preliminary Evaluation of a Novel AIF-Free Estimation Method

PubMed Central

Ginsburg, Shoshana B.; Taimen, Pekka; Merisaari, Harri; Vainio, Paula; Boström, Peter J.; Aronen, Hannu J.; Jambor, Ivan; Madabhushi, Anant

2017-01-01

Purpose To develop and evaluate a prostate-based method (PBM) for estimating pharmacokinetic parameters on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) by leveraging inherent differences in pharmacokinetic characteristics between the peripheral zone (PZ) and transition zone (TZ). Materials and Methods This retrospective study, approved by the Institutional Review Board, included 40 patients who underwent a multiparametric 3T MRI examination and subsequent radical prostatectomy. A two-step PBM for estimating pharmacokinetic parameters exploited the inherent differences in pharmacokinetic characteristics associated with the TZ and PZ. First, the reference region model was implemented to estimate ratios of Ktrans between normal TZ and PZ. Subsequently, the reference region model was leveraged again to estimate values for Ktrans and ve for every prostate voxel. The parameters of PBM were compared with those estimated using an arterial input function (AIF) derived from the femoral arteries. The ability of the parameters to differentiate prostate cancer (PCa) from benign tissue was evaluated on a voxel and lesion level. Additionally, the effect of temporal downsampling of the DCE MRI data was assessed. Results Significant differences (P < 0.05) in PBM Ktrans between PCa lesions and benign tissue were found in 26/27 patients with TZ lesions and in 33/38 patients with PZ lesions; significant differences in AIF-based Ktrans occurred in 26/27 and 30/38 patients, respectively. The 75th and 100th percentiles of Ktrans and ve estimated using PBM positively correlated with lesion size (P < 0.05). Conclusion Pharmacokinetic parameters estimated via PBM outperformed AIF-based parameters in PCa detection. PMID:27285161

Using the Secondary Electrons (SE) of scanning electron microscope with NIST`s MONSEL-II program to obtain improved linewidth measurements and slope angles of line edges on a MMIC GaAs device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sartore, R.G.

1996-12-31

In the evaluation of GaAs devices from the MMIC (Monolithic Microwave Integrated Circuits) program for Army applications, there was a requirement to obtain accurate linewidth measurements on the nominal 0.5 micrometer gate lengths used to fabricate these devices. Preliminary measurements indicated a significant variation (typically 10% to 30% but could be more) in the critical dimensional measurements of the gate length, gate to source distance and gate to drain distance. Passivation introduced a margin of error, which was removed by plasma etching. Additionally, the high aspect ratio (4-5) of the thick gold (Au) conductors also introduced measurement difficulties. The finalmore » measurements were performed were performed after the thick gold conductor was removed and only the barrier metal remained, which was approximately 250 nanometer thick platinum on GaAs substrate. The thickness was measured using the penetration voltage method. Linescan of the secondary electron signal as it scans across the gate is shown in Figure 1. This linescan is an average of 5 linescans in the immediate vicinity to reduce noise levels. A SEM image of the area is shown in Figure 2. To obtain a rough estimate of the slopes of the gate lines at the edges, the sample was tilted to 75 degrees and the image in Figure 3 was obtained. From this figure a rough estimate of the sloped edges, using a protractor, was obtained, approximately 27 degrees, +/-5 degrees.« less

A preliminary evaluation of an F100 engine parameter estimation process using flight data

NASA Technical Reports Server (NTRS)

Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

1990-01-01

The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the compact engine model (CEM). In this step, the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion control law development.

A preliminary evaluation of an F100 engine parameter estimation process using flight data

NASA Technical Reports Server (NTRS)

Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

1990-01-01

The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the 'compact engine model' (CEM). In this step the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion-control-law development.

Preliminary Work in Obtaining Site-Directed Mutants of Hen Egg White Lysozyme

NASA Technical Reports Server (NTRS)

Holmes, Leonard D.

1996-01-01

Protein crystal growth studies are recognized as a critical endeavor in the field of molecular biotechnology. The scientific applications of this field include the understanding of how enzymes function and the accumulation of accurate information of atomic structures, a key factor in the process of rational drug design. NASA has committed substantial investment and resources to the field of protein crystal growth and has conducted many microgravity protein crystal growth experiments aboard shuttle flights. Crystals grown in space tend to be larger, denser and have a more perfect habit and geometry. These improved properties gained in the microgravity environment of space result largely from the reduction of solutal convection, and the elimination of sedimentation at the growing crystal surface. Shuttle experiments have yielded many large, high quality crystals that are suitable for high resolution X-ray diffraction analysis. Examples of biologically important macromolecules which have been successfully crystallized during shuttle missions include: lysozyme, isocitrate lyase, gamma-interferon, insulin, human serum albumin and canavalin. Numerous other examples are also available. In addition to obtaining high quality crystals, investigators are also interested in learning the mechanisms by which the growth events take place. Crystallization experiments indicate that for the enzyme HEWL, measured growth rates do not follow mathematical models for 2D nucleation and dislocation-led growth of tetragonal protein crystals. As has been suggested by the laboratory of Marc L. Pusey, a possible explanation for the disagreement between observation and data is that HEWL tetraconal crystals form by aggregated units of lysozyme in supersaturated solutions. Surface measurement data was shown to fit very well with a model using an octamer unit cell as the growth unit. According to this model, the aggregation pathway and subsequent crystal growth is described by: monomer

Obtaining appropriate interval estimates for age when multiple indicators are used: evaluation of an ad-hoc procedure.

PubMed

Fieuws, Steffen; Willems, Guy; Larsen-Tangmose, Sara; Lynnerup, Niels; Boldsen, Jesper; Thevissen, Patrick

2016-03-01

When an estimate of age is needed, typically multiple indicators are present as found in skeletal or dental information. There exists a vast literature on approaches to estimate age from such multivariate data. Application of Bayes' rule has been proposed to overcome drawbacks of classical regression models but becomes less trivial as soon as the number of indicators increases. Each of the age indicators can lead to a different point estimate ("the most plausible value for age") and a prediction interval ("the range of possible values"). The major challenge in the combination of multiple indicators is not the calculation of a combined point estimate for age but the construction of an appropriate prediction interval. Ignoring the correlation between the age indicators results in intervals being too small. Boldsen et al. (2002) presented an ad-hoc procedure to construct an approximate confidence interval without the need to model the multivariate correlation structure between the indicators. The aim of the present paper is to bring under attention this pragmatic approach and to evaluate its performance in a practical setting. This is all the more needed since recent publications ignore the need for interval estimation. To illustrate and evaluate the method, Köhler et al. (1995) third molar scores are used to estimate the age in a dataset of 3200 male subjects in the juvenile age range.

A preliminary assessment of the true morels (Morchella) in Newfoundland and Labrador

USDA-ARS?s Scientific Manuscript database

A preliminary assessment of true morels (Morchella) from Newfoundland and Labrador (NL) was obtained by using DNA sequence data from portions of three genes to identify 20 collections from Newfoundland and one from a remote location in Labrador. To place this work in a broader context, data on 25 co...

Patient-specific pharmacokinetic parameter estimation on dynamic contrast-enhanced MRI of prostate: Preliminary evaluation of a novel AIF-free estimation method.

PubMed

Ginsburg, Shoshana B; Taimen, Pekka; Merisaari, Harri; Vainio, Paula; Boström, Peter J; Aronen, Hannu J; Jambor, Ivan; Madabhushi, Anant

2016-12-01

To develop and evaluate a prostate-based method (PBM) for estimating pharmacokinetic parameters on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) by leveraging inherent differences in pharmacokinetic characteristics between the peripheral zone (PZ) and transition zone (TZ). This retrospective study, approved by the Institutional Review Board, included 40 patients who underwent a multiparametric 3T MRI examination and subsequent radical prostatectomy. A two-step PBM for estimating pharmacokinetic parameters exploited the inherent differences in pharmacokinetic characteristics associated with the TZ and PZ. First, the reference region model was implemented to estimate ratios of K trans between normal TZ and PZ. Subsequently, the reference region model was leveraged again to estimate values for K trans and v e for every prostate voxel. The parameters of PBM were compared with those estimated using an arterial input function (AIF) derived from the femoral arteries. The ability of the parameters to differentiate prostate cancer (PCa) from benign tissue was evaluated on a voxel and lesion level. Additionally, the effect of temporal downsampling of the DCE MRI data was assessed. Significant differences (P < 0.05) in PBM K trans between PCa lesions and benign tissue were found in 26/27 patients with TZ lesions and in 33/38 patients with PZ lesions; significant differences in AIF-based K trans occurred in 26/27 and 30/38 patients, respectively. The 75 th and 100 th percentiles of K trans and v e estimated using PBM positively correlated with lesion size (P < 0.05). Pharmacokinetic parameters estimated via PBM outperformed AIF-based parameters in PCa detection. J. Magn. Reson. Imaging 2016;44:1405-1414. © 2016 International Society for Magnetic Resonance in Medicine.

Cycles till failure of silver-zinc cells with completing failures modes: Preliminary data analysis

NASA Technical Reports Server (NTRS)

Sidik, S. M.; Leibecki, H. F.; Bozek, J. M.

1980-01-01

One hundred and twenty nine cells were run through charge-discharge cycles until failure. The experiment design was a variant of a central composite factorial in five factors. Preliminary data analysis consisted of response surface estimation of life. Batteries fail under two basic modes; a low voltage condition and an internal shorting condition. A competing failure modes analysis using maximum likelihood estimation for the extreme value life distribution was performed. Extensive diagnostics such as residual plotting and probability plotting were employed to verify data quality and choice of model.

7 CFR 614.7 - Preliminary technical determinations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Preliminary technical determinations. 614.7 Section... Preliminary technical determinations. (a) A preliminary technical determination becomes final 30 days after... purpose of gathering additional information and discussing the facts relating to the preliminary technical...

Preliminary Impact Crater Dimensions on 433 Eros from the NEAR Laser Rangefinder and Imager

NASA Technical Reports Server (NTRS)

Barnouin-Jha, O. S.; Garvin, J. B.; Cheng, A. F.; Zuber, M.; Smith, D.; Neumann, G.; Murchie, S.; Veverka, J.; Robinson, M.

2001-01-01

We report preliminary observations obtained from the NEAR Laser Rangefinder (NLR) and NEAR Multispectral Imager (MSI) for approx. 300 craters seen on 433 Eros to address Eros crater formation and degradation processes. Additional information is contained in the original extended abstract.

Fiscal year 1981 US corn and soybeans pilot preliminary experiment plan, phase 1

NASA Technical Reports Server (NTRS)

Livingston, G. P.; Nedelman, K. S.; Norwood, D. F.; Smith, J. H. (Principal Investigator)

1981-01-01

A draft of the preliminary experiment plan for the foreign commodity production forecasting project fiscal year 1981 is presented. This draft plan includes: definition of the phase 1 and 2 U.S. pilot objectives; the proposed experiment design to evaluate crop calendar, area estimation, and area aggregation components for corn and soybean technologies using 1978/1979 crop-year data; a description of individual sensitivity evaluations of the baseline corn and soybean segment classification procedure; and technology and data assessment in support of the corn and soybean estimation technology for use in the U.S. central corn belt.

A preliminary study of subjective frequency estimates of words spoken in Cantonese.

PubMed

Yip, M C

2001-06-01

A database is presented of the subjective frequency estimates for a set of 30 Chinese homophones. The estimates are based on analysis of responses from a simple listening task by 120 University students. On the listening task, they are asked to mention the first meaning thought of upon hearing a Chinese homophone by writing down the corresponding Chinese characters. There was correlation of .66 between the frequency of spoken and written words, suggesting distributional information about the lexical representations is generally independent of modality. These subjective frequency counts should be useful in the construction of material sets for research on word recognition using spoken Chinese (Cantonese).

A preliminary benefit-cost study of a Sandia wind farm.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ehlen, Mark Andrew; Griffin, Taylor; Loose, Verne W.

In response to federal mandates and incentives for renewable energy, Sandia National Laboratories conducted a feasibility study of installing an on-site wind farm on Sandia National Laboratories and Kirtland Air Force Base property. This report describes this preliminary analysis of the costs and benefits of installing and operating a 15-turbine, 30-MW-capacity wind farm that delivers an estimated 16 percent of 2010 onsite demand. The report first describes market and non-market economic costs and benefits associated with operating a wind farm, and then uses a standard life-cycle costing and benefit-cost framework to estimate the costs and benefits of a wind farm.more » Based on these 'best-estimates' of costs and benefits and on factor, uncertainty and sensitivity analysis, the analysis results suggest that the benefits of a Sandia wind farm are greater than its costs. The analysis techniques used herein are applicable to the economic assessment of most if not all forms of renewable energy.« less

Long range radio tracking of sea turtles and polar bear: Instrumentation and preliminary results

NASA Technical Reports Server (NTRS)

Baldwin, H. A.

1972-01-01

Instrumentation developed for studies of path behavior of the green sea turtle and migration movement of polar bear is described. Preliminary results bearing on navigation ability in these species are presented. Both species operate in difficult environments, and the problems faced in the design of electronic instrumentation for these studies are not completely specified at this time. However, the critical factors yet to be understood are primarily related to the behavior of instrumented animals. The data obtained with these experimental techniques are included, first to illustrate the technique and, second to provide initial preliminary results bearing on animal navigation.

Fully Automated Quantitative Estimation of Volumetric Breast Density from Digital Breast Tomosynthesis Images: Preliminary Results and Comparison with Digital Mammography and MR Imaging.

PubMed

Pertuz, Said; McDonald, Elizabeth S; Weinstein, Susan P; Conant, Emily F; Kontos, Despina

2016-04-01

To assess a fully automated method for volumetric breast density (VBD) estimation in digital breast tomosynthesis (DBT) and to compare the findings with those of full-field digital mammography (FFDM) and magnetic resonance (MR) imaging. Bilateral DBT images, FFDM images, and sagittal breast MR images were retrospectively collected from 68 women who underwent breast cancer screening from October 2011 to September 2012 with institutional review board-approved, HIPAA-compliant protocols. A fully automated computer algorithm was developed for quantitative estimation of VBD from DBT images. FFDM images were processed with U.S. Food and Drug Administration-cleared software, and the MR images were processed with a previously validated automated algorithm to obtain corresponding VBD estimates. Pearson correlation and analysis of variance with Tukey-Kramer post hoc correction were used to compare the multimodality VBD estimates. Estimates of VBD from DBT were significantly correlated with FFDM-based and MR imaging-based estimates with r = 0.83 (95% confidence interval [CI]: 0.74, 0.90) and r = 0.88 (95% CI: 0.82, 0.93), respectively (P < .001). The corresponding correlation between FFDM and MR imaging was r = 0.84 (95% CI: 0.76, 0.90). However, statistically significant differences after post hoc correction (α = 0.05) were found among VBD estimates from FFDM (mean ± standard deviation, 11.1% ± 7.0) relative to MR imaging (16.6% ± 11.2) and DBT (19.8% ± 16.2). Differences between VDB estimates from DBT and MR imaging were not significant (P = .26). Fully automated VBD estimates from DBT, FFDM, and MR imaging are strongly correlated but show statistically significant differences. Therefore, absolute differences in VBD between FFDM, DBT, and MR imaging should be considered in breast cancer risk assessment.

Fully Automated Quantitative Estimation of Volumetric Breast Density from Digital Breast Tomosynthesis Images: Preliminary Results and Comparison with Digital Mammography and MR Imaging

PubMed Central

Pertuz, Said; McDonald, Elizabeth S.; Weinstein, Susan P.; Conant, Emily F.

2016-01-01

Purpose To assess a fully automated method for volumetric breast density (VBD) estimation in digital breast tomosynthesis (DBT) and to compare the findings with those of full-field digital mammography (FFDM) and magnetic resonance (MR) imaging. Materials and Methods Bilateral DBT images, FFDM images, and sagittal breast MR images were retrospectively collected from 68 women who underwent breast cancer screening from October 2011 to September 2012 with institutional review board–approved, HIPAA-compliant protocols. A fully automated computer algorithm was developed for quantitative estimation of VBD from DBT images. FFDM images were processed with U.S. Food and Drug Administration–cleared software, and the MR images were processed with a previously validated automated algorithm to obtain corresponding VBD estimates. Pearson correlation and analysis of variance with Tukey-Kramer post hoc correction were used to compare the multimodality VBD estimates. Results Estimates of VBD from DBT were significantly correlated with FFDM-based and MR imaging–based estimates with r = 0.83 (95% confidence interval [CI]: 0.74, 0.90) and r = 0.88 (95% CI: 0.82, 0.93), respectively (P < .001). The corresponding correlation between FFDM and MR imaging was r = 0.84 (95% CI: 0.76, 0.90). However, statistically significant differences after post hoc correction (α = 0.05) were found among VBD estimates from FFDM (mean ± standard deviation, 11.1% ± 7.0) relative to MR imaging (16.6% ± 11.2) and DBT (19.8% ± 16.2). Differences between VDB estimates from DBT and MR imaging were not significant (P = .26). Conclusion Fully automated VBD estimates from DBT, FFDM, and MR imaging are strongly correlated but show statistically significant differences. Therefore, absolute differences in VBD between FFDM, DBT, and MR imaging should be considered in breast cancer risk assessment. © RSNA, 2015 Online supplemental material is available for this article. PMID:26491909

25 CFR 11.1105 - Preliminary inquiry.

Code of Federal Regulations, 2014 CFR

2014-04-01

... shelter care, the children's court shall conduct a preliminary inquiry with 24 hours for the purpose of... to the parents, guardian or custodian, the children's court shall conduct a preliminary inquiry... custodian is not present at the preliminary inquiry, the children's court shall determine what efforts have...

25 CFR 11.1105 - Preliminary inquiry.

Code of Federal Regulations, 2012 CFR

2012-04-01

... shelter care, the children's court shall conduct a preliminary inquiry with 24 hours for the purpose of... to the parents, guardian or custodian, the children's court shall conduct a preliminary inquiry... custodian is not present at the preliminary inquiry, the children's court shall determine what efforts have...

25 CFR 11.1105 - Preliminary inquiry.

Code of Federal Regulations, 2011 CFR

2011-04-01

... shelter care, the children's court shall conduct a preliminary inquiry with 24 hours for the purpose of... to the parents, guardian or custodian, the children's court shall conduct a preliminary inquiry... custodian is not present at the preliminary inquiry, the children's court shall determine what efforts have...

25 CFR 11.1105 - Preliminary inquiry.

Code of Federal Regulations, 2013 CFR

2013-04-01

... shelter care, the children's court shall conduct a preliminary inquiry with 24 hours for the purpose of... to the parents, guardian or custodian, the children's court shall conduct a preliminary inquiry... custodian is not present at the preliminary inquiry, the children's court shall determine what efforts have...

25 CFR 11.1105 - Preliminary inquiry.

Code of Federal Regulations, 2010 CFR

2010-04-01

... shelter care, the children's court shall conduct a preliminary inquiry with 24 hours for the purpose of... to the parents, guardian or custodian, the children's court shall conduct a preliminary inquiry... custodian is not present at the preliminary inquiry, the children's court shall determine what efforts have...

EXECUTIVE SUMMARY FOR FULL-SCALE DUAL-ALKALI DEMONSTRATION AT LOUISVILLE GAS AND ELECTRIC CO. - PRELIMINARY DESIGN AND COST ESTIMATE

EPA Science Inventory

The report is the executive summary for the preliminary design of the dual-alkali system, designed by Combustion Equipment Associates, Inc./Arthur D. Little, Inc. and being installed to control SO2 emissions from Louisville Gas and Electric Company's Cane Run Unit No. 6 boiler. T...

Preliminary results on complex ceramic layers deposition by atmospheric plasma spraying

NASA Astrophysics Data System (ADS)

Florea, Costel; Bejinariu, Costicǎ; Munteanu, Corneliu; Cimpoeşu, Nicanor

2017-04-01

In this article we obtain thin layers from complex ceramic powders using industrial equipment based on atmospheric plasma spraying. We analyze the influence of the substrate material roughness on the quality of the thin layers using scanning electron microscopy (SEM) and X-ray dispersive energy analyze (EDAX). Preliminary results present an important dependence between the surface state and the structural and chemical homogeneity.

Local Estimators for Spacecraft Formation Flying

NASA Technical Reports Server (NTRS)

Fathpour, Nanaz; Hadaegh, Fred Y.; Mesbahi, Mehran; Nabi, Marzieh

2011-01-01

A formation estimation architecture for formation flying builds upon the local information exchange among multiple local estimators. Spacecraft formation flying involves the coordination of states among multiple spacecraft through relative sensing, inter-spacecraft communication, and control. Most existing formation flying estimation algorithms can only be supported via highly centralized, all-to-all, static relative sensing. New algorithms are needed that are scalable, modular, and robust to variations in the topology and link characteristics of the formation exchange network. These distributed algorithms should rely on a local information-exchange network, relaxing the assumptions on existing algorithms. In this research, it was shown that only local observability is required to design a formation estimator and control law. The approach relies on breaking up the overall information-exchange network into sequence of local subnetworks, and invoking an agreement-type filter to reach consensus among local estimators within each local network. State estimates were obtained by a set of local measurements that were passed through a set of communicating Kalman filters to reach an overall state estimation for the formation. An optimization approach was also presented by means of which diffused estimates over the network can be incorporated in the local estimates obtained by each estimator via local measurements. This approach compares favorably with that obtained by a centralized Kalman filter, which requires complete knowledge of the raw measurement available to each estimator.

Improved estimation of random vibration loads in launch vehicles

NASA Technical Reports Server (NTRS)

Mehta, R.; Erwin, E.; Suryanarayan, S.; Krishna, Murali M. R.

1993-01-01

Random vibration induced load is an important component of the total design load environment for payload and launch vehicle components and their support structures. The current approach to random vibration load estimation is based, particularly at the preliminary design stage, on the use of Miles' equation which assumes a single degree-of-freedom (DOF) system and white noise excitation. This paper examines the implications of the use of multi-DOF system models and response calculation based on numerical integration using the actual excitation spectra for random vibration load estimation. The analytical study presented considers a two-DOF system and brings out the effects of modal mass, damping and frequency ratios on the random vibration load factor. The results indicate that load estimates based on the Miles' equation can be significantly different from the more accurate estimates based on multi-DOF models.

Some preliminary estimates of energy utilization in even-aged northern hardwoods

Treesearch

William B. Leak

1970-01-01

Estimates of energy utilization from various sources indicate that even-aged northern hardwood stands utilize less than 1/2 percent of net solar radiation for wood, leaf, and seed production, and only about 1/10 percent for production of merchantable wood. Forest managers should seek to understand and manipulate the remaining 99+ percent of solar energy, for improving...

Preliminary deformation model for National Seismic Hazard map of Indonesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meilano, Irwan; Gunawan, Endra; Sarsito, Dina

Preliminary deformation model for the Indonesia’s National Seismic Hazard (NSH) map is constructed as the block rotation and strain accumulation function at the elastic half-space. Deformation due to rigid body motion is estimated by rotating six tectonic blocks in Indonesia. The interseismic deformation due to subduction is estimated by assuming coupling on subduction interface while deformation at active fault is calculated by assuming each of the fault‘s segment slips beneath a locking depth or in combination with creeping in a shallower part. This research shows that rigid body motion dominates the deformation pattern with magnitude more than 15 mm/year, except inmore » the narrow area near subduction zones and active faults where significant deformation reach to 25 mm/year.« less

21 CFR 1315.34 - Obtaining an import quota.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Obtaining an import quota. 1315.34 Section 1315.34 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS... imports, the estimated medical, scientific, and industrial needs of the United States, the establishment...

40 CFR 161.170 - Preliminary analysis.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Preliminary analysis. (a) If the product is produced by an integrated system, the applicant must provide a preliminary analysis of each technical grade of active ingredient contained in the product to identify all... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Preliminary analysis. 161.170 Section...

Oxygen Consumption of Tilapia and Preliminary Mass Flows through a Prototype Closed Aquaculture System

NASA Technical Reports Server (NTRS)

Muller, Matthew S.; Bauer, Clarence F.

1994-01-01

Performance of NASA's prototype CELSS Breadboard Project Closed Aquaculture System was evaluated by estimating gas exchange quantification and preliminary carbon and nitrogen balances. The total system oxygen consumption rate was 535 mg/hr kg/fish (cv = 30%) when stocked with Tilapia aurea populations (fresh weights of 97 +/- 19 to 147 +/- 36 g/fish for various trials). Oxygen consumption by T. aurea (260 mg/hr kg/fish) contributed to approximately one-half of total system demand. Continuous carbon dioxide quantification methods were analyzed using the,relation of carbon dioxide to oxygen consumption. Overall food conversion rates averaged 18.2 +/- 3.2%. Major pathways for nitrogen and carbon in the system were described with preliminary mass closure of 60-80% and 60% for nitrogen and carbon.

NASA/Navy life/cruise fan preliminary design report

NASA Technical Reports Server (NTRS)

1975-01-01

Preliminary design studies were performed to define a turbotip lift/cruise fan propulsion system for a Navy multimission aircraft. The fan is driven by the exhausts of the YJ97-GE-100 turbojet or a 20 percent Growth J97 configuration as defined during the studies. The LCF459 fan configuration defined has a tip diameter of 1.50 meters (59.0 inches) and develops a design point thrust of 75,130 N (16,890 lbs) at a fan pressure ratio of 1.319. The fan has an estimated weight of 386 kg (850 lbs). Trade studies performed to define the selected configuration are described.

Uncertainties in obtaining high reliability from stress-strength models

NASA Technical Reports Server (NTRS)

Neal, Donald M.; Matthews, William T.; Vangel, Mark G.

1992-01-01

There has been a recent interest in determining high statistical reliability in risk assessment of aircraft components. The potential consequences are identified of incorrectly assuming a particular statistical distribution for stress or strength data used in obtaining the high reliability values. The computation of the reliability is defined as the probability of the strength being greater than the stress over the range of stress values. This method is often referred to as the stress-strength model. A sensitivity analysis was performed involving a comparison of reliability results in order to evaluate the effects of assuming specific statistical distributions. Both known population distributions, and those that differed slightly from the known, were considered. Results showed substantial differences in reliability estimates even for almost nondetectable differences in the assumed distributions. These differences represent a potential problem in using the stress-strength model for high reliability computations, since in practice it is impossible to ever know the exact (population) distribution. An alternative reliability computation procedure is examined involving determination of a lower bound on the reliability values using extreme value distributions. This procedure reduces the possibility of obtaining nonconservative reliability estimates. Results indicated the method can provide conservative bounds when computing high reliability. An alternative reliability computation procedure is examined involving determination of a lower bound on the reliability values using extreme value distributions. This procedure reduces the possibility of obtaining nonconservative reliability estimates. Results indicated the method can provide conservative bounds when computing high reliability.

Cognitive-Behavioral Therapy for PANDAS-Related Obsessive-Compulsive Disorder: Findings From A Preliminary Waitlist Controlled Open Trial

ERIC Educational Resources Information Center

Storch, Eric A.; Murphy, Tanya K.; Geffken, Gary R.; Mann, Giselle; Adkins, Jennifer; Merlo, Lisa J.; Duke, Danny; Munson, Melissa; Swaine, Zoe; Goodman, Wayne K.

2006-01-01

Objective: To provide preliminary estimates of the effectiveness of cognitive-behavioral therapy (CBT) in treating pediatric obsessive-compulsive disorder (OCD) of the pediatric autoimmune neuropsychiatric disorders associated with streptococcus (PANDAS) subtype. Method: Seven children with OCD of the PANDAS subtype (range 9-13 years) were treated…

A Preliminary Survey of Short Time-Scale Optical Variables with ROTSE

NASA Astrophysics Data System (ADS)

McKay, T.; Akerlof, C.; Balsano, R.; Bloch, J.; Casperson, D.; Gisler, G.; Kehoe, R.; Lee, B.; Marshall, S.; Rykoff, E.; Smith, D. A.; Szymanski, J.; Wren, J.; ROTSE Collaboration

2000-12-01

We have performed a preliminary optical survey of short timescale variability with the ROTSE-I telephoto array. The data sample is divided into two parts. The first is a survey of 256 square degrees ( 120k sources) imaged every 80 s for a cumulative 20 hrs to a sensitivity of approximately magnitude 15.5. The second is a similarly sensitive survey of 512 square degrees ( 250k sources) imaged every 80 s (with 7 minute gaps) for a total of approximately 60 hrs. A further 0.4 mag. increase in sensitivity is obtained by co-adding these frames in pairs. We have identified a variety of new variable stars in this sample, including many Delta Scuti stars and contact binaries. Preliminary characterization of these sources will be presented.

The ACCE method: an approach for obtaining quantitative or qualitative estimates of residual confounding that includes unmeasured confounding

PubMed Central

Smith, Eric G.

2015-01-01

Background:  Nonrandomized studies typically cannot account for confounding from unmeasured factors.  Method:  A method is presented that exploits the recently-identified phenomenon of  “confounding amplification” to produce, in principle, a quantitative estimate of total residual confounding resulting from both measured and unmeasured factors.  Two nested propensity score models are constructed that differ only in the deliberate introduction of an additional variable(s) that substantially predicts treatment exposure.  Residual confounding is then estimated by dividing the change in treatment effect estimate between models by the degree of confounding amplification estimated to occur, adjusting for any association between the additional variable(s) and outcome. Results:  Several hypothetical examples are provided to illustrate how the method produces a quantitative estimate of residual confounding if the method’s requirements and assumptions are met.  Previously published data is used to illustrate that, whether or not the method routinely provides precise quantitative estimates of residual confounding, the method appears to produce a valuable qualitative estimate of the likely direction and general size of residual confounding. Limitations:  Uncertainties exist, including identifying the best approaches for: 1) predicting the amount of confounding amplification, 2) minimizing changes between the nested models unrelated to confounding amplification, 3) adjusting for the association of the introduced variable(s) with outcome, and 4) deriving confidence intervals for the method’s estimates (although bootstrapping is one plausible approach). Conclusions:  To this author’s knowledge, it has not been previously suggested that the phenomenon of confounding amplification, if such amplification is as predictable as suggested by a recent simulation, provides a logical basis for estimating total residual confounding. The method's basic approach is

Evaluating clinically meaningful change on the ITP-PAQ: preliminary estimates of minimal important differences.

PubMed

Mathias, Susan D; Gao, Sue K; Rutstein, Mark; Snyder, Claire F; Wu, Albert W; Cella, David

2009-02-01

Interpretation of data from health-related quality of life (HRQoL) questionnaires can be enhanced with the availability of minimally important difference (MID) estimates. This information will aid clinicians in interpreting HRQoL differences within patients over time and between treatment groups. The Immune Thrombocytopenic Purpura (ITP)-Patient Assessment Questionnaire (PAQ) is the only comprehensive HRQoL questionnaire available for adults with ITP. Forty centers from within the US and Europe enrolled ITP patients into one of two multicenter, randomized, placebo-controlled, double-blind, 6-month, phase III clinical trials of romiplostim. Patients enrolled in these studies self-administered the ITP-PAQ and two items assessing global change (anchors) at baseline and weeks 4, 12, and 24. Using data from the ITP-PAQ and these two anchors, an anchor-based estimate was computed and combined with the standard error of measurement and standard deviation to compute a distribution-based estimate in order to provide an MID range for each of the 11 scales of the ITP-PAQ. A total of 125 patients participated in these clinical trials and provided data for use in these analyses. Combining results from anchor- and distribution-based approaches, MID values were computed for 9 of the 11 scales. MIDs ranged from 8 to 12 points for Symptoms, Bother, Psychological, Overall QOL, Social Activity, Menstrual Symptoms, and Fertility, while the range was 10 to 15 points for the Fatigue and Activity scales of the ITP-PAQ. These estimates, while slightly higher than other published MID estimates, were consistent with moderate effect sizes. These MID estimates will serve as a useful tool to researchers and clinicians using the ITP-PAQ, providing guidance for interpretation of baseline scores as well as changes in ITP-PAQ scores over time. Additional work should be done to finalize these initial estimates using more appropriate anchors that correlate more highly with the ITP-PAQ scales.

Combining nutation and surface gravity observations to estimate the Earth's core and inner core resonant frequencies

NASA Astrophysics Data System (ADS)

Ziegler, Yann; Lambert, Sébastien; Rosat, Séverine; Nurul Huda, Ibnu; Bizouard, Christian

2017-04-01

Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have been shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the intermediate results of the ongoing project of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by the International VLBI Service for geodesy and astrometry (IVS) as the result of a combination of inputs from various IVS analysis centers, and surface gravity data from about 15 SG stations. We address here the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting for nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package, the preliminary estimates of the resonant periods, and the correlations between parameters.

Preliminary Experiments for the Assessment of VW-Band Links for Space-Earth Communications

NASA Technical Reports Server (NTRS)

Nessel, James A.; Acosta, Roberto J.; Miranda, Felix A.

2013-01-01

Since September 2012, NASA Glenn Research Center has deployed a microwave profiling radiometer at White Sands, NM, to estimate atmospheric propagation effects on communications links in the V and W bands (71-86GHz). Estimates of attenuation statistics in the millimeter wave due to gaseous and cloud components of the atmosphere show good agreement with current ITU-R models, but fail to predict link performance in the presence of moderate to heavy rain rates, due to the inherent limitations of passive radiometry. Herein, we discuss the preliminary results of these measurements and describe a design for a terrestrial link experiment to validaterefine existing rain attenuation models in the VW-bands.

Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft

NASA Technical Reports Server (NTRS)

Mascitti, V. R.; Maglieri, D. J. (Editor); Raney, J. P. (Editor)

1979-01-01

NASA computer codes in the areas of preliminary sizing and enroute performance, takeoff and landing performance, aircraft noise prediction, and economics were used in a preliminary noise tradeoff study for a Mach 2.7 design supersonic cruise concept. Aerodynamic configuration data were based on wind-tunnel model tests and related analyses. Aircraft structural characteristics and weight were based on advanced structural design methodologies, assuming conventional titanium technology. The most advanced noise prediction techniques available were used, and aircraft operating costs were estimated using accepted industry methods. The 4-engines cycles included in the study were based on assumed 1985 technology levels. Propulsion data was provided by aircraft manufacturers. Additional empirical data is needed to define both noise reduction features and other operating characteristics of all engine cycles under study. Data on VCE design parameters, coannular nozzle inverted flow noise reduction and advanced mechanical suppressors are urgently needed to reduce the present uncertainties in studies of this type.

Predicting Success of Preliminary Surgical Residents: A Multi-Institutional Study.

PubMed

Al Fayyadh, Mohammed J; Heller, Stephanie F; Rajab, Taufiek Konrad; Gardner, Aimee K; Bloom, Jordan P; Rawlings, Jeremy A; Mullen, John T; Smink, Douglas S; Farley, David R; Willis, Ross E; Dent, Daniel L

A nondesignated preliminary surgery (NDPS) position encompasses 1 year of training provided by many general surgery residencies. Our aim was to assess factors predicting success and provide evidence for program directors to support career guidance to preliminary residents. Retrospective cohort study of 221 NDPS residents who entered 5 university-based institutions were identified from 2009 to 2013. Records for trainees were reviewed. We defined primary success as obtaining a categorical position in the specialty of choice and secondary success as obtaining a categorical position in any specialty immediately after finishing their NDPS training. Statistical evaluation was performed using chi-square analysis, independent t-test and logistic regression using α <0.05. Of the 221 NDPS residents, 217 (98%) completed postgraduate year (PGY)-1 and 65 (29%) completed PGY-2. Totally, 90 (41%) obtained categorical general surgery positions, 89 (40%) obtained categorical positions in other specialties, and 42 (19%) failed to obtain a categorical position immediately after their NDPS years. Ultimately, 139 (63%) of residents achieved primary success and 40 (18%) additional residents obtained categorical positions in specialties other than their first choice, resulting in a total of 179 (81%) of residents obtaining categorical positions. Mean United States Medical Licensing Examination step 1 and step 2 scores for those who obtained secondary success were 227 and 234 vs. 214 and 219, respectively, for those who failed to secure a categorical position (p < 0.01). United States Medical Licensing Examination step 2 score was a significant predictor of primary (p < 0.03) and secondary success (p < 0.02). Of 65 PGY-2 NDPS residents, 32 (49%) achieved primary success, and 11 (17%) others achieved secondary success for a total of 43 (66%). For PGY-2 NDPS, American Board of Surgery In-Training Examination was the only significant predictor of primary and secondary success (p < 0.02 and

Cost estimating procedure for unmanned satellites

NASA Astrophysics Data System (ADS)

Greer, H.; Campbell, H. G.

1980-11-01

Historical costs from 11 unmanned satellite programs were analyzed. From these data, total satellite cost estimating relationships (CERs) were developed for use during preliminary design studies. A time-related factor, which it is believed accounts for differences in technology, was observed in the data. Stratification of the data by type of payload was also found to be necessary. Cost differences that stem from production quantity variations were accounted for by adjustment factors developed from standard learning curve theory. An example to illustrate use of the CERs is provided.

Improved quantitative analysis of spectra using a new method of obtaining derivative spectra based on a singular perturbation technique.

PubMed

Li, Zhigang; Wang, Qiaoyun; Lv, Jiangtao; Ma, Zhenhe; Yang, Linjuan

2015-06-01

Spectroscopy is often applied when a rapid quantitative analysis is required, but one challenge is the translation of raw spectra into a final analysis. Derivative spectra are often used as a preliminary preprocessing step to resolve overlapping signals, enhance signal properties, and suppress unwanted spectral features that arise due to non-ideal instrument and sample properties. In this study, to improve quantitative analysis of near-infrared spectra, derivatives of noisy raw spectral data need to be estimated with high accuracy. A new spectral estimator based on singular perturbation technique, called the singular perturbation spectra estimator (SPSE), is presented, and the stability analysis of the estimator is given. Theoretical analysis and simulation experimental results confirm that the derivatives can be estimated with high accuracy using this estimator. Furthermore, the effectiveness of the estimator for processing noisy infrared spectra is evaluated using the analysis of beer spectra. The derivative spectra of the beer and the marzipan are used to build the calibration model using partial least squares (PLS) modeling. The results show that the PLS based on the new estimator can achieve better performance compared with the Savitzky-Golay algorithm and can serve as an alternative choice for quantitative analytical applications.

Estimating tropical-forest density profiles from multibaseline interferometric SAR

NASA Technical Reports Server (NTRS)

Treuhaft, Robert; Chapman, Bruce; dos Santos, Joao Roberto; Dutra, Luciano; Goncalves, Fabio; da Costa Freitas, Corina; Mura, Jose Claudio; de Alencastro Graca, Paulo Mauricio

2006-01-01

Vertical profiles of forest density are potentially robust indicators of forest biomass, fire susceptibility and ecosystem function. Tropical forests, which are among the most dense and complicated targets for remote sensing, contain about 45% of the world's biomass. Remote sensing of tropical forest structure is therefore an important component to global biomass and carbon monitoring. This paper shows preliminary results of a multibasline interfereomtric SAR (InSAR) experiment over primary, secondary, and selectively logged forests at La Selva Biological Station in Costa Rica. The profile shown results from inverse Fourier transforming 8 of the 18 baselines acquired. A profile is shown compared to lidar and field measurements. Results are highly preliminary and for qualitative assessment only. Parameter estimation will eventually replace Fourier inversion as the means to producing profiles.

Acute health impacts of airborne particles estimated from satellite remote sensing.

PubMed

Wang, Zhaoxi; Liu, Yang; Hu, Mu; Pan, Xiaochuan; Shi, Jing; Chen, Feng; He, Kebin; Koutrakis, Petros; Christiani, David C

2013-01-01

Satellite-based remote sensing provides a unique opportunity to monitor air quality from space at global, continental, national and regional scales. Most current research focused on developing empirical models using ground measurements of the ambient particulate. However, the application of satellite-based exposure assessment in environmental health is still limited, especially for acute effects, because the development of satellite PM(2.5) model depends on the availability of ground measurements. We tested the hypothesis that MODIS AOD (aerosol optical depth) exposure estimates, obtained from NASA satellites, are directly associated with daily health outcomes. Three independent healthcare databases were used: unscheduled outpatient visits, hospital admissions, and mortality collected in Beijing metropolitan area, China during 2006. We use generalized linear models to compare the short-term effects of air pollution assessed by ground monitoring (PM(10)) with adjustment of absolute humidity (AH) and AH-calibrated AOD. Across all databases we found that both AH-calibrated AOD and PM(10) (adjusted by AH) were consistently associated with elevated daily events on the current day and/or lag days for cardiovascular diseases, ischemic heart diseases, and COPD. The relative risks estimated by AH-calibrated AOD and PM(10) (adjusted by AH) were similar. Additionally, compared to ground PM(10), we found that AH-calibrated AOD had narrower confidence intervals for all models and was more robust in estimating the current day and lag day effects. Our preliminary findings suggested that, with proper adjustment of meteorological factors, satellite AOD can be used directly to estimate the acute health impacts of ambient particles without prior calibrating to the sparse ground monitoring networks. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of survey design and catch rate estimation on total catch estimates in Chinook salmon fisheries

USGS Publications Warehouse

McCormick, Joshua L.; Quist, Michael C.; Schill, Daniel J.

2012-01-01

Roving–roving and roving–access creel surveys are the primary techniques used to obtain information on harvest of Chinook salmon Oncorhynchus tshawytscha in Idaho sport fisheries. Once interviews are conducted using roving–roving or roving–access survey designs, mean catch rate can be estimated with the ratio-of-means (ROM) estimator, the mean-of-ratios (MOR) estimator, or the MOR estimator with exclusion of short-duration (≤0.5 h) trips. Our objective was to examine the relative bias and precision of total catch estimates obtained from use of the two survey designs and three catch rate estimators for Idaho Chinook salmon fisheries. Information on angling populations was obtained by direct visual observation of portions of Chinook salmon fisheries in three Idaho river systems over an 18-d period. Based on data from the angling populations, Monte Carlo simulations were performed to evaluate the properties of the catch rate estimators and survey designs. Among the three estimators, the ROM estimator provided the most accurate and precise estimates of mean catch rate and total catch for both roving–roving and roving–access surveys. On average, the root mean square error of simulated total catch estimates was 1.42 times greater and relative bias was 160.13 times greater for roving–roving surveys than for roving–access surveys. Length-of-stay bias and nonstationary catch rates in roving–roving surveys both appeared to affect catch rate and total catch estimates. Our results suggest that use of the ROM estimator in combination with an estimate of angler effort provided the least biased and most precise estimates of total catch for both survey designs. However, roving–access surveys were more accurate than roving–roving surveys for Chinook salmon fisheries in Idaho.

Light scattering application for quantitative estimation of apoptosis

NASA Astrophysics Data System (ADS)

Bilyy, Rostyslav O.; Stoika, Rostyslav S.; Getman, Vasyl B.; Bilyi, Olexander I.

2004-05-01

Estimation of cell proliferation and apoptosis are in focus of instrumental methods used in modern biomedical sciences. Present study concerns monitoring of functional state of cells, specifically the development of their programmed death or apoptosis. The available methods for such purpose are either very expensive, or require time-consuming operations. Their specificity and sensitivity are frequently not sufficient for making conclusions which could be used in diagnostics or treatment monitoring. We propose a novel method for apoptosis measurement based on quantitative determination of cellular functional state taking into account their physical characteristics. This method uses the patented device -- laser microparticle analyser PRM-6 -- for analyzing light scattering by the microparticles, including cells. The method gives an opportunity for quick, quantitative, simple (without complicated preliminary cell processing) and relatively cheap measurement of apoptosis in cellular population. The elaborated method was used for studying apoptosis expression in murine leukemia cells of L1210 line and human lymphoblastic leukemia cells of K562 line. The results obtained by the proposed method permitted measuring cell number in tested sample, detecting and quantitative characterization of functional state of cells, particularly measuring the ratio of the apoptotic cells in suspension.

Preliminary results toward injection locking of an incoherent laser array

NASA Technical Reports Server (NTRS)

Daher, J.

1986-01-01

The preliminary results of phase locking an incoherent laser array to a master source in an attempt to achieve coherent operation are presented. The techniques necessary to demonstrate phase locking are described along with some topics for future consideration. As expected, the results obtained suggest that injection locking of an array, where the spacing between adjacent longitudinal modes of its elements is significantly larger than the locking bandwidth, may not be feasible.

A new lithium-ion battery internal temperature on-line estimate method based on electrochemical impedance spectroscopy measurement

NASA Astrophysics Data System (ADS)

Zhu, J. G.; Sun, Z. C.; Wei, X. Z.; Dai, H. F.

2015-01-01

The power battery thermal management problem in EV (electric vehicle) and HEV (hybrid electric vehicle) has been widely discussed, and EIS (electrochemical impedance spectroscopy) is an effective experimental method to test and estimate the status of the battery. Firstly, an electrochemical-based impedance matrix analysis for lithium-ion battery is developed to describe the impedance response of electrochemical impedance spectroscopy. Then a method, based on electrochemical impedance spectroscopy measurement, has been proposed to estimate the internal temperature of power lithium-ion battery by analyzing the phase shift and magnitude of impedance at different ambient temperatures. Respectively, the SoC (state of charge) and temperature have different effects on the impedance characteristics of battery at various frequency ranges in the electrochemical impedance spectroscopy experimental study. Also the impedance spectrum affected by SoH (state of health) is discussed in the paper preliminary. Therefore, the excitation frequency selected to estimate the inner temperature is in the frequency range which is significantly influenced by temperature without the SoC and SoH. The intrinsic relationship between the phase shift and temperature is established under the chosen excitation frequency. And the magnitude of impedance related to temperature is studied in the paper. In practical applications, through obtaining the phase shift and magnitude of impedance, the inner temperature estimation could be achieved. Then the verification experiments are conduced to validate the estimate method. Finally, an estimate strategy and an on-line estimation system implementation scheme utilizing battery management system are presented to describe the engineering value.

Application of Stein and related parametric empirical Bayes estimators to the nuclear plant reliability data system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, J.R.; Heger, A.S.; Koen, B.V.

1984-04-01

This report is the result of a preliminary feasibility study of the applicability of Stein and related parametric empirical Bayes (PEB) estimators to the Nuclear Plant Reliability Data System (NPRDS). A new estimator is derived for the means of several independent Poisson distributions with different sampling times. This estimator is applied to data from NPRDS in an attempt to improve failure rate estimation. Theoretical and Monte Carlo results indicate that the new PEB estimator can perform significantly better than the standard maximum likelihood estimator if the estimation of the individual means can be combined through the loss function or throughmore » a parametric class of prior distributions.« less

Preliminary experiments to estimate the PE.MA.M (PElagic MArine Mesocosm) offshore behaviour

NASA Astrophysics Data System (ADS)

Albani, Marta; Piermattei, Viviana; Stefanì, Chiara; Marcelli, Marco

2016-04-01

The phytoplankton community is controlled not only by local environmental conditions but also by physical processes occurring on different temporal and spatial scales. Hydrodynamic local conditions play an important role in marine ecosystems. Several studies have shown that hydrodynamic conditions can influence the phytoplankton settling velocity, vertical and horizontal distribution and formation of cyanobacterial blooms. Mesocosms are useful structures to simulate marine environment at mesoscale resolution; allowing to closely approximate biotic or abiotic parameters of interest directly in nature. In this work an innovative structure named PE.MA.M (PElagic MArine Mesocosm) is presented and tested. Laboratory experiments have been conducted in order to observe seasonal variations of biomass behaviour in two different hydrodynamic conditions: outside as well as whithin the PE.MA.M. We have evaluated whether it is possible to isolate a natural system from external water mass hydrodynamic exchanges and to assume that phytoplankton cells' transition is limited at the net and sea interface. Preliminary experiments test the isolating capacity of the net, to determine the currents' attenuation rate and to estimate the possible PE.MA.M. offshore behaviour. In the first investigation, we monitored the diffusion of phytoplankton cells. The PE.MA.M. exterior and interior were simulated using a plexiglass tank divided into two half-tanks (Aout-Bin) by a septum consisting of a net like a PE.MA.M. The tank was filled up with 10 L of water and only the half-tank Aout was filled up with 10 ml of phytoplankton culture (Clorella sp.). We monitored the chlorophyll concentrations for 24 hours. The two tanks had similar concentrations after 4 hours (2.70322 mg/m³ Aout and 2.37245 mg/m3 Bin) and this constant relationship was maintened until the end of the test. In the second investigation we used clod cards to measure water motions.We conducted two experiments within tank, the first

Two-dimensional echo-cardiographic estimation of left atrial volume and volume load in patients with congenital heart disease.

PubMed

Kawaguchi, A; Linde, L M; Imachi, T; Mizuno, H; Akutsu, H

1983-12-01

To estimate the left atrial volume (LAV) and pulmonary blood flow in patients with congenital heart disease (CHD), we employed two-dimensional echocardiography (TDE). The LAV was measured in dimensions other than those obtained in conventional M-mode echocardiography (M-mode echo). Mathematical and geometrical models for LAV calculation using the standard long-axis, short-axis and apical four-chamber planes were devised and found to be reliable in a preliminary study using porcine heart preparations, although length (10%), area (20%) and volume (38%) were significantly and consistently underestimated with echocardiography. Those models were then applied and correlated with angiocardiograms (ACG) in 25 consecutive patients with suspected CHD. In terms of the estimation of the absolute LAV, accuracy seemed commensurate with the number of the dimensions measured. The correlation between data obtained by TDE and ACG varied with changing hemodynamics such as cardiac cycle, absolute LAV and presence or absence of volume load. The left atrium was found to become spherical and progressively underestimated with TDE at ventricular endsystole, in larger LAV and with increased volume load. Since this tendency became less pronounced in measuring additional dimensions, reliable estimation of the absolute LAV and volume load was possible when 2 or 3 dimensions were measured. Among those calculation models depending on 2 or 3 dimensional measurements, there was only a small difference in terms of accuracy and predictability, although algorithm used varied from one model to another. This suggests that accurate cross-sectional area measurement is critically important for volume estimation rather than any particular algorithm involved. Cross-sectional area measurement by TDE integrated into a three dimensional equivalent allowed a reliable estimate of the LAV or volume load in a variety of hemodynamic situations where M-mode echo was not reliable.

Preliminary Results in Asteroid Mass Determination

NASA Astrophysics Data System (ADS)

Aslan, Z.; Gumerov, R. I.; Hudkova, L. A.; Ivantsov, A. V.; Khamitov, I.; Pinigin, G. I.

2006-08-01

Asteroid masses are extremely important for the determination of their bulk densities, especially for the discussed relatively high porosities in about 20 to 30% of the studied bodies. The problem will have some coverage in clarifying errors of both mass and volume determinations. We have used lists of encounters for massive and less massive asteroids, prepared by J.L. Hilton, which cover relatively contemporary period of optical observations, 1950-2005. These observations were taken from the MPC database of observations. The model of the motions uses integrations of relativistic equations for perturbing asteroids (Ceres, Pallas, Vesta, and others concerned), perturbed asteroid. Positions and velocities of the Sun and large planets are directly taken from the DE405. The necessary initial conditions were taken from the HORIZONS system. By the adjustment of dynamical model parameters (both initial conditions and perturbing masses for asteroids) there were determined preliminary masses (in 10^-10 of Sun mass) for seven asteroids: (7) Iris 0.090±0.008, (10) Hygiea 0.213±0.030, (24) Themis 0.010±0.024, (45) Eugenia 0.012±0.025, (52) Europa 0.362±0.041, (87) Sylvia 0.180±0.090, (165) Loreley 0.157±0.100. These masses were calculated from difficult cases, where the earlier study by some authors gave negative masses in the unweighted calculations. The values obtained were compared with other estimations. Both the two-fold increase in the number of observations up the present and the active boundary on the determined mass parameter or equivalent logarithm transform should have given physically meaningful values in any case.

Preliminary study of the pilot's workload during emergency procedures in helicopters air operations.

PubMed

Bezerra, Flávio G V; Ribeiro, Selma L O

2012-01-01

Military air operations and law enforcement operations in helicopters are examples of activities that require high performance of the operator. This article aimed at presenting a preliminary analysis of data obtained in the initial study in order to validate the instruments and the research protocol that focuses on the analysis of the workload imposed on helicopter pilots in emergency situations. The research was conducted in an environment of real flight training and used the NASA-TLX Scale to assess the workload and an interview guide to obtain reports on the main tasks performed. Preliminary data obtained is related to the participation of 10 (ten) volunteer pilots with experience in different types of helicopters. Four scenarios involving helicopter emergency procedures of HB-350 "Squirrel" were outlined. For this article, the analysis used only the data regarding the Physical and Mental Demands of the NASA-TLX Scale. Preliminarily, the results indicate that the "time pressure" as a factor contributing to increase mental requirement in emergency situations in flight, and that this increase was reflected in the request of mental processes such as: identification of the breakdown, attention and monitoring parameters. Future steps include extending the sample and adding physiological tools to better understand the effects of these types of emergencies on pilot performance and flight safety.

Preliminary acclimation strategies for successful startup in conventional biofilters.

PubMed

Elías, Ana; Barona, Astrid; Gallastegi, Gorka; Rojo, Naiara; Gurtubay, Luis; Ibarra-Berastegi, Gabriel

2010-08-01

The question of how to obtain the best inocula for conventional biofilters arises when an acclimation/adaptation procedure is to be applied. Bearing in mind that no standardized procedure for acclimating inocula exists, certain preliminary strategies for obtaining an active inoculum from wastewater treatment sludge are proposed in this work. Toluene was the contaminant to be degraded. Concerning the prior separation of sludge phases, no obvious advantage was found in separating the supernatant phase of the sludge before acclimation. As far as a continuous or discontinuous acclimation mode is concerned, the latter is recommended for rapidly obtaining acclimated sludge samples by operating the system for no longer than 1 month. The continuous mode rendered similar degradation rates, although it required longer operating time. Nevertheless, the great advantage of the continuous system lay in the absence of daily maintenance and the ready availability of the activated sample.

Site characterization of the Romanian Seismic Network stations: a national initiative and its first preliminary results

NASA Astrophysics Data System (ADS)

Grecu, Bogdan; Zahria, Bogdan; Manea, Elena; Neagoe, Cristian; Borleanu, Felix; Diaconescu, Mihai; Constantinescu, Eduard; Bala, Andrei

2017-04-01

The seismic activity in Romania is dominated by the intermediate-depth earthquakes occurring in Vrancea region, although weak to moderate crustal earthquakes are produced regularly in different areas of the country. The National Institute for Earth Physics (NIEP) built in the last years an impressive infrastructure for monitoring this activity, known as the Romanian Seismic Network (RSN). At present, RSN consists of 122 seismic stations, of which 70 have broadband velocity sensors and 42 short period sensors. One hundred and eleven stations out of 122 have accelerometer sensors collocated with velocity sensors and only 10 stations have only accelerometers. All the stations record continuously the ground motion and the data are transmitted in real-time to the Romanian National Data Center (RoNDC), in Magurele. Last year, NIEP has started a national project that addresses the characterization of all real-time seismic stations that constitute the RSN. We present here the steps that were undertaken and the preliminary results obtained since the beginning the project. The first two activities consisted of collecting all the existent technical and geological data, with emphasize on the latter. Then, we performed station noise investigations and analyses in order to characterize the noise level and estimate the resonances of the sites. The computed H/V ratios showed clear resonant peaks at different frequencies which correlate relatively well with the thickness of the sedimentary package beneath the stations. The polarization analysis of the H/V ratios indicates for some stations a strong directivity of the resonance peak which suggests possible topographic effects at the stations. At the same time, special attention was given to the estimation of the site amplification from earthquake data. The spectral ratios obtained from the analysis of more than 50 earthquakes with magnitudes (Mw) larger than 4.1 are characterized by similar resonance peaks as those obtained from

Preliminary sonic boom correlation of predicted and measured levels for STS-1 entry

NASA Technical Reports Server (NTRS)

Garcia, F., Jr.; Morrison, K. M.; Jones, J. H.; Henderson, H. R.

1982-01-01

A preliminary analysis correlating peaks from sonic boom pressure signatures recorded during the descent trajectory of the Orbiter Columbia, which landed in the dry lake bed at Edwards Air Force Base (EAFB), California, with measured wind tunnel signatures extrapolated from flight altitudes to the ground has been made for Mach numbers ranging from 1.3 to 6. The flight pressure signatures were recorded by microphones positioned at ground level near the groundtrack, whereas the wind tunnel signatures were measured during a test of a 0.0041-scale model Orbiter. The agreement between overpressure estimates based on wind tunnel data using preliminary flight trajectory data and oscillograph traces from ground measurements appears reasonable at this time for the range of Mach numbers considered. More detailed studies using final flight trajectory data and digitized ground measured data will be performed.

Space transfer vehicle concepts and requirements study. Volume 3, book 1: Program cost estimates

NASA Technical Reports Server (NTRS)

Peffley, Al F.

1991-01-01

The Space Transfer Vehicle (STV) Concepts and Requirements Study cost estimate and program planning analysis is presented. The cost estimating technique used to support STV system, subsystem, and component cost analysis is a mixture of parametric cost estimating and selective cost analogy approaches. The parametric cost analysis is aimed at developing cost-effective aerobrake, crew module, tank module, and lander designs with the parametric cost estimates data. This is accomplished using cost as a design parameter in an iterative process with conceptual design input information. The parametric estimating approach segregates costs by major program life cycle phase (development, production, integration, and launch support). These phases are further broken out into major hardware subsystems, software functions, and tasks according to the STV preliminary program work breakdown structure (WBS). The WBS is defined to a low enough level of detail by the study team to highlight STV system cost drivers. This level of cost visibility provided the basis for cost sensitivity analysis against various design approaches aimed at achieving a cost-effective design. The cost approach, methodology, and rationale are described. A chronological record of the interim review material relating to cost analysis is included along with a brief summary of the study contract tasks accomplished during that period of review and the key conclusions or observations identified that relate to STV program cost estimates. The STV life cycle costs are estimated on the proprietary parametric cost model (PCM) with inputs organized by a project WBS. Preliminary life cycle schedules are also included.

Preliminary results on passive eddy current damper technology for SSME turbomachinery

NASA Technical Reports Server (NTRS)

Cunningham, R. E.

1985-01-01

Some preliminary results have been obtained for the dynamic response of a rotor operating over a speed range of 800 to 10,000 rpm. Amplitude frequency plots show the lateral vibratory response of an unbalanced rotor with and without external damping. The mode of damping is by means of eddy currents generated with 4 c shaped permanent magnets installed at the lower bearing of a vertically oriented rotor. The lower ball bearing and its damper assembly are totally immersed in liquid nitrogen at a temperature of -197 deg C (-320 deg F). These preliminary results for a referenced or base line passive eddy current damper assembly show that the amplitude of synchronous vibration is reduced at the resonant frequency. Measured damping coefficients were calculated to phi = .086; this compares with a theoretically calculated value of phi = .079.

Optimal Bandwidth for Multitaper Spectrum Estimation

DOE PAGES

Haley, Charlotte L.; Anitescu, Mihai

2017-07-04

A systematic method for bandwidth parameter selection is desired for Thomson multitaper spectrum estimation. We give a method for determining the optimal bandwidth based on a mean squared error (MSE) criterion. When the true spectrum has a second-order Taylor series expansion, one can express quadratic local bias as a function of the curvature of the spectrum, which can be estimated by using a simple spline approximation. This is combined with a variance estimate, obtained by jackknifing over individual spectrum estimates, to produce an estimated MSE for the log spectrum estimate for each choice of time-bandwidth product. The bandwidth that minimizesmore » the estimated MSE then gives the desired spectrum estimate. Additionally, the bandwidth obtained using our method is also optimal for cepstrum estimates. We give an example of a damped oscillatory (Lorentzian) process in which the approximate optimal bandwidth can be written as a function of the damping parameter. Furthermore, the true optimal bandwidth agrees well with that given by minimizing estimated the MSE in these examples.« less

Preliminary Studies of Ions Emission in a Small Plasma Focus Device of Hundreds of Joules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, Jose; Pavez, Cristian; Soto, Leopoldo

2009-01-21

Ion beam emission in plasma focus (PF) discharges was originally investigated to explain the strong forward anisotropy observed in the neutron. Several properties of PF emitted deuteron beams have been measured, including their angular distributions and energy spectra in devices operating with energies from 1 kJ to 1 MJ. At present there is a growing interest in the development of very small PF devices operating under 1 kJ. As part of the characterization program of the very low energy PF devices (<1 kJ) developed at the Chilean Nuclear Energy Commission, the charges particle emission in hydrogen (H{sub 2}) and mixturemore » (H{sub 2}+%Ar) are being studied. In order to obtain an estimation of the ions energy spectrum and ionization grade, by using time of flight method, a graphite collector system operating in the bias ion collector mode was constructed and it is being used. Preliminary results of the ion beams measurements in different experimental conditions, at a plasma focus device of 400 joules (PF-400 J) are presented.« less

3122 Florence: Lightcurve Analysis and Preliminary Model

NASA Astrophysics Data System (ADS)

Franco, Lorenzo; Bacci, Paolo; Maestripieri, Martina; Baj, Giorgio; Galli, Gianni; Marchini, Alessandro; Noschese, Alfonso; Valvasori, Adriano; Caselli, Catia; Barbieri, Lorenzo; Facchini, Mauro

2018-04-01

Photometric observations of 3122 Florence were carried out on 12 nights between 2017 Aug 30 and Oct 6. This allowed us to determine a synodic period range from P = 2.3568 h ± 0.0002 to 2.3576 h ± 0.0002 with amplitude ranging from A = 0.22 to 0.16 mag. Multi-band photometric sessions and low resolution visible spectrum analysis shows a taxonomic class S, according to the SMASS II classification. Using lightcurve inversion method we also obtained a preliminary shape and spin axis model of (λ = 164° ± 15, β = -86° ± 5) with a sidereal period Psid = 2.3583 h ± 0.0005.

25 CFR 700.115 - Preliminary acquisition notice.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Acquisition and Disposal of Habitations and/or Improvements § 700.115 Preliminary acquisition notice. As soon as feasible in the acquisition process, the Commission shall issue a preliminary acquisition notice.../her habitations and/or improvements. (b) Explain that such preliminary acquisition notice is not a...

[Development of key indicators for nurses performance evaluation and estimation of their weights for management by objectives].

PubMed

Lee, Eun Hwa; Ahn, Sung Hee

2010-02-01

This methodological research was designed to develop performance evaluation key indicators (PEKIs) for management by objectives (MBO) and to estimate their weights for hospital nurses. The PEKIs were developed by selecting preliminary indicators from a literature review, examining content validity and identifying their level of importance. Data were collected from November 14, 2007 to February 18, 2008. Data set for importance of indicators was obtained from 464 nurses and weights of PEKIs domain was from 453 nurses, who worked for at least 2 yr in one of three hospitals. Data were analyzed using X(2)-test, factor analysis, and the Analytical Hierarchy Process. Based upon Content Validity Index of .8 or above, 61 indicators were selected from the 100 preliminary indicators. Finally, 40 PEKIs were developed from the 61 indicators, and categorized into 10 domains. The highest weight of the 10 domains was customer satisfaction, which was followed by patient education, direct nursing care, profit increase, safety management, improvement of nursing quality, completeness of nursing records, enhancing competence of nurses, indirect nursing care, and cost reduction, in that order. PEKIs and their weights can be utilized for impartial evaluation and MBO for hospital nurses. Further research to verify PEKIs would lead to successful implementation of MBO.

Waste Feed Delivery System Phase 1 Preliminary Reliability and Availability and Maintainability Analysis [SEC 1 and 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

CARLSON, A.B.

The document presents updated results of the preliminary reliability, availability, maintainability analysis performed for delivery of waste feed from tanks 241-AZ-101 and 241-AN-105 to British Nuclear Fuels Limited, inc. under the Tank Waste Remediation System Privatization Contract. The operational schedule delay risk is estimated and contributing factors are discussed.

Preliminary Results of the Analysis

NASA Technical Reports Server (NTRS)

Pap, Judit

1995-01-01

The preliminary results of the photometry of CaII K spectroheliograms taken at the NationalSolar Observatory at Sacramento peak are presented in this paper. We have digitizedspectroheliograms for 1980 (maximum of SC21), 1985 (minimum of SC21), 1987 (beginning of theascending phase of SC22), 1988 and 1989 (ascending phase and maximum of SC22), and 1992(declining phase of SC22). We have analyzed images for 1992 and separated the plages, the magneticnetwork, internetwork elements and the chromospheric background using histogram method. Wehave derived the intensity and area of these features as well as the full disk intensity (Spatial KIndex). The Spatial K Index has been compared to the spectral Ca K index derived from the lineprofiles and total solar and UV irradiance measured by the UARS and NOAA9 satellites. Thecontribution of plages, the magnetic network and internetwork element to the changes observed intotal solar and UV irradiances are also estimated.

Preliminary Experiments for the Assessment of V/W-band Links for Space-Earth Communications

NASA Technical Reports Server (NTRS)

Nessel, James A.; Acosta, Roberto J.; Miranda, Felix A.

2013-01-01

Since September 2012, NASA Glenn Research Center has deployed a microwave profiling radiometer at White Sands, NM, to estimate atmospheric propagation effects on communications links in the V and W bands (71-86GHz). Estimates of attenuation statistics in the millimeter wave due to gaseous and cloud components of the atmosphere show good agreement with current ITU-R models, but fail to predict link performance in the presence of moderate to heavy rain rates, due to the inherent limitations of passive radiometry. Herein, we discuss the preliminary results of these measurements and describe a design for a terrestrial link experiment to validate/refine existing rain attenuation models in the V/Wbands.

Precision and accuracy of age estimates obtained from anal fin spines, dorsal fin spines, and sagittal otoliths for known-age largemouth bass

USGS Publications Warehouse

Klein, Zachary B.; Bonvechio, Timothy F.; Bowen, Bryant R.; Quist, Michael C.

2017-01-01

Sagittal otoliths are the preferred aging structure for Micropterus spp. (black basses) in North America because of the accurate and precise results produced. Typically, fisheries managers are hesitant to use lethal aging techniques (e.g., otoliths) to age rare species, trophy-size fish, or when sampling in small impoundments where populations are small. Therefore, we sought to evaluate the precision and accuracy of 2 non-lethal aging structures (i.e., anal fin spines, dorsal fin spines) in comparison to that of sagittal otoliths from known-age Micropterus salmoides (Largemouth Bass; n = 87) collected from the Ocmulgee Public Fishing Area, GA. Sagittal otoliths exhibited the highest concordance with true ages of all structures evaluated (coefficient of variation = 1.2; percent agreement = 91.9). Similarly, the low coefficient of variation (0.0) and high between-reader agreement (100%) indicate that age estimates obtained from sagittal otoliths were the most precise. Relatively high agreement between readers for anal fin spines (84%) and dorsal fin spines (81%) suggested the structures were relatively precise. However, age estimates from anal fin spines and dorsal fin spines exhibited low concordance with true ages. Although use of sagittal otoliths is a lethal technique, this method will likely remain the standard for aging Largemouth Bass and other similar black bass species.

Prediction of the Main Engine Power of a New Container Ship at the Preliminary Design Stage

NASA Astrophysics Data System (ADS)

Cepowski, Tomasz

2017-06-01

The paper presents mathematical relationships that allow us to forecast the estimated main engine power of new container ships, based on data concerning vessels built in 2005-2015. The presented approximations allow us to estimate the engine power based on the length between perpendiculars and the number of containers the ship will carry. The approximations were developed using simple linear regression and multivariate linear regression analysis. The presented relations have practical application for estimation of container ship engine power needed in preliminary parametric design of the ship. It follows from the above that the use of multiple linear regression to predict the main engine power of a container ship brings more accurate solutions than simple linear regression.

Preliminary study of soil permeability properties using principal component analysis

NASA Astrophysics Data System (ADS)

Yulianti, M.; Sudriani, Y.; Rustini, H. A.

2018-02-01

Soil permeability measurement is undoubtedly important in carrying out soil-water research such as rainfall-runoff modelling, irrigation water distribution systems, etc. It is also known that acquiring reliable soil permeability data is rather laborious, time-consuming, and costly. Therefore, it is desirable to develop the prediction model. Several studies of empirical equations for predicting permeability have been undertaken by many researchers. These studies derived the models from areas which soil characteristics are different from Indonesian soil, which suggest a possibility that these permeability models are site-specific. The purpose of this study is to identify which soil parameters correspond strongly to soil permeability and propose a preliminary model for permeability prediction. Principal component analysis (PCA) was applied to 16 parameters analysed from 37 sites consist of 91 samples obtained from Batanghari Watershed. Findings indicated five variables that have strong correlation with soil permeability, and we recommend a preliminary permeability model, which is potential for further development.

Proposal of the Use of a Fuzzy Stochastic Network for the Preliminary Evaluation of the Feasibility of the Process of the Adaptation of a Historical Building to a Particular Form of Use

NASA Astrophysics Data System (ADS)

Radziszewska-Zielina, Elżbieta; Śladowski, Grzegorz

2017-10-01

The knowledge of a real estate developer regarding the possibilities of adapting a historical building to a particular form of use and the knowledge of the approximate costs associated with this process are some of the more important pieces of information that can influence the making of the final decision regarding commencing with such a project. The preliminary analysis of the process of adapting a historical building is a difficult task due to the specific character of this type of project. The specific character of such a project is proven by the fact that the often insufficient analysis of the structure and architecture of a building and its historical substance at the stage of carrying out the process of adaptation can generate the necessity to perform previously unforeseen additional actions. An equally important problem is the difficulty in estimating the funds required to conduct research and the analyses associated with developing design documentation, as well as carrying out construction and conservation work. This is why a real estate developer should analyse various scenarios of carrying out a project during the stage of the preliminary analysis of its feasibility, taking into account the fact that some of them can occur in a random manner. The authors of the paper propose the use of one of the planning tools known as stochastic networks, which can be used to model the undetermined structure of these types of projects. Fuzzy logic was used in order to estimate uncertain values of the parameters of a model (the probability of performing work and paying the associated costs). The approach proposed by the authors was used to perform a preliminary analysis of the adaptation of the Arsenal in Gdańsk to a particular form of use along with estimating the costs associated with it. The results that were obtained have confirmed the potential of this method for real-world application.

28 CFR 2.48 - Revocation: Preliminary interview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Revocation: Preliminary interview. 2.48....48 Revocation: Preliminary interview. (a) Interviewing officer. A parolee who is retaken on a warrant issued by a Commissioner shall be given a preliminary interview by an official designated by the Regional...

Instrumentation, methods, and preliminary evaluation of evapotranspiration for a grassland in the Arid Lands Ecology Reserve, Benton County, Washington, May-October 1990

USGS Publications Warehouse

Tomlinson, S.A.

1994-01-01

The report describes instrumentation, methods, and preliminary results for a study on evapo- transpiration at a grassland in Snively Basin of the Arid Lands Ecology Reserve. Instrumentation was used to collect data from May 30 to October 15, 1990. A combination of the Bowen-ratio and Penman-Monteith methods was used to calculate estimates of evapotranspiration. The Bowen-ratio method could be used to calculate estimates of latent-heat flux and evapotranspiration during only parts of the study period. Latent-heat flux values obtained during these periods were used in the Penman-Monteith method to estimate the canopy resistance. These canopy resistances were averaged for each day and the average values were used to recalculate the laten-heat flux for all periods using the Penman-Monteith method. The canopy resistance ranged from near zero during periods of rainfall to more than 40,000 seconds per meter during periods of extreme dryness. Evapotranspiration estimates varied during the study period. Daily evapotranspiration ranged from less than 0.1 millimeter on some days in August, September, and October to about 2 milli- meters on June 3 and August 22. Monthly totals of evapotranspiration were as follows: June, 28.2 millimeters; July, 10.5 millimeters; August, 15.0 millimeters; September, 5.3 millimeters; and October 1-15, 1.8 millimeters. Evapotranspiration values given in the report are estimates. Some error, perhaps as low as 25 percent on a daily basis and 4 percent on a monthly total basis, is probably introduced into these estimates through complexities of data collection, data analysis, and canopy-resistance estimation, particularly when evapotranspiration was near zero.

Preliminary validation of a new methodology for estimating dose reduction protocols in neonatal chest computed radiographs

NASA Astrophysics Data System (ADS)

Don, Steven; Whiting, Bruce R.; Hildebolt, Charles F.; Sehnert, W. James; Ellinwood, Jacquelyn S.; Töpfer, Karin; Masoumzadeh, Parinaz; Kraus, Richard A.; Kronemer, Keith A.; Herman, Thomas; McAlister, William H.

2006-03-01

The risk of radiation exposure is greatest for pediatric patients and, thus, there is a great incentive to reduce the radiation dose used in diagnostic procedures for children to "as low as reasonably achievable" (ALARA). Testing of low-dose protocols presents a dilemma, as it is unethical to repeatedly expose patients to ionizing radiation in order to determine optimum protocols. To overcome this problem, we have developed a computed-radiography (CR) dose-reduction simulation tool that takes existing images and adds synthetic noise to create realistic images that correspond to images generated with lower doses. The objective of our study was to determine the extent to which simulated, low-dose images corresponded with original (non-simulated) low-dose images. To make this determination, we created pneumothoraces of known volumes in five neonate cadavers and obtained images of the neonates at 10 mR, 1 mR and 0.1 mR (as measured at the cassette plate). The 10-mR exposures were considered "relatively-noise-free" images. We used these 10 mR-images and our simulation tool to create simulated 0.1- and 1-mR images. For the simulated and original images, we identified regions of interest (ROI) of the entire chest, free-in-air region, and liver. We compared the means and standard deviations of the ROI grey-scale values of the simulated and original images with paired t tests. We also had observers rate simulated and original images for image quality and for the presence or absence of pneumothoraces. There was no statistically significant difference in grey-scale-value means nor standard deviations between simulated and original entire chest ROI regions. The observer performance suggests that an exposure >=0.2 mR is required to detect the presence or absence of pneumothoraces. These preliminary results indicate that the use of the simulation tool is promising for achieving ALARA exposures in children.

Preliminary genetic linkage map of the abalone Haliotis diversicolor Reeve

NASA Astrophysics Data System (ADS)

Shi, Yaohua; Guo, Ximing; Gu, Zhifeng; Wang, Aimin; Wang, Yan

2010-05-01

Haliotis diversicolor Reeve is one of the most important mollusks cultured in South China. Preliminary genetic linkage maps were constructed with amplified fragment length polymorphism (AFLP) markers. A total of 2 596 AFLP markers were obtained from 28 primer combinations in two parents and 78 offsprings. Among them, 412 markers (15.9%) were polymorphic and segregated in the mapping family. Chi-square tests showed that 151 (84.4%) markers segregated according to the expected 1:1 Mendelian ratio ( P<0.05) in the female parent, and 200 (85.8%) in the male parent. For the female map, 179 markers were used for linkage analysis and 90 markers were assigned to 17 linkage groups with an average interval length of 25.7 cm. For the male map, 233 markers were used and 94 were mapped into 18 linkage groups, with an average interval of 25.0 cm. The estimated genome length was 2 773.0 cm for the female and 2 817.1 cm for the male map. The observed length of the linkage map was 1 875.2 cm and 1 896.5 cm for the female and male maps, respectively. When doublets were considered, the map length increased to 2 152.8 cm for the female and 2 032.7 cm for the male map, corresponding to genome coverage of 77.6% and 72.2%, respectively.

Preliminary evaluation of the sensitivity to change of DE-STA motor unit number estimation in the upper trapezius muscle in amyotrophic lateral sclerosis.

PubMed

Ives, Colleen T; Findlater, Karen; Shoesmith, Christen L; Doherty, Timothy J

2015-07-01

To compare the sensitivity to change of decomposition-enhanced spike-triggered averaging (DE-STA) motor unit number estimation (MUNE) in the upper trapezius (UT) to that of various clinical outcome measures in subjects with amyotrophic lateral sclerosis (ALS). Ten patients with clinically probable or definite ALS were assessed at baseline, 2, 4 and 6months with the following outcome measures: manual muscle testing in five upper extremity muscle groups, scapular elevation and elbow flexion peak force measured with hand-held dynamometry, MUNE, forced vital capacity and the Revised ALS Functional Rating Scale (ALSFRS-R). ALSFRS-R was the only outcome measure for which there was a significant difference between baseline and 6months (p=0.034). ALSFRS-R had the largest standardized response mean (SRM), and was thus the most sensitive to change. MUNE demonstrated a decline over 6months and a moderate SRM (-0.63). This study has demonstrated a moderate degree of sensitivity to change for DE-STA MUNE as applied to the UT in subjects with ALS. In this preliminary study, DE-STA MUNE detected motor unit loss over 6months, with a moderate degree of sensitivity, in the upper trapezius of subjects with ALS. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Role of preliminary registry data in development of a clinical trial for an innovative device: a small but integral piece of a health policy initiative

PubMed Central

Ricci, Donald R.; de Vries, Joost; Blanc, Raphael

2017-01-01

ABSTRACT Establishing a national health policy at a macro level involves the integration of a series of health initiatives across a spectrum of activities, including clinical care. Evaluation of the safety and efficacy of a new medical device ultimately evolves to testing in humans. The pathway to a formal prospective clinical trial includes a stepwise appreciation of pre-clinical data and detailed analysis of data obtained from preliminary registries, where information about appropriate patient selection and use of the device is obtained. Evaluation of procedural and follow-up efficacy and safety data in a preliminary series of cases, chosen to simulate published data, allows the design and conduct of clinical trials that are required to verify preliminary observations, closing the loop on one aspect of modifying health policy decisions. PMID:28321285

Decentralization, stabilization, and estimation of large-scale linear systems

NASA Technical Reports Server (NTRS)

Siljak, D. D.; Vukcevic, M. B.

1976-01-01

In this short paper we consider three closely related aspects of large-scale systems: decentralization, stabilization, and estimation. A method is proposed to decompose a large linear system into a number of interconnected subsystems with decentralized (scalar) inputs or outputs. The procedure is preliminary to the hierarchic stabilization and estimation of linear systems and is performed on the subsystem level. A multilevel control scheme based upon the decomposition-aggregation method is developed for stabilization of input-decentralized linear systems Local linear feedback controllers are used to stabilize each decoupled subsystem, while global linear feedback controllers are utilized to minimize the coupling effect among the subsystems. Systems stabilized by the method have a tolerance to a wide class of nonlinearities in subsystem coupling and high reliability with respect to structural perturbations. The proposed output-decentralization and stabilization schemes can be used directly to construct asymptotic state estimators for large linear systems on the subsystem level. The problem of dimensionality is resolved by constructing a number of low-order estimators, thus avoiding a design of a single estimator for the overall system.

Preliminary estimates of Gulf Stream characteristics from TOPEX data and a precise gravimetric geoid

NASA Technical Reports Server (NTRS)

Rapp, Richard H.; Smith, Dru A.

1994-01-01

TOPEX sea surface height data has been used, with a gravimetric geoid, to calculate sea surface topography across the Gulf Stream. This topography was initially computed for nine tracks on cycles 21 to 29. Due to inaccurate geoid undulations on one track, results for eight tracks are reported. The sea surface topography estimates were used to calculate parameters that describe Gulf Stream characteristics from two models of the Gulf Stream. One model was based on a Gaussian representation of the velocity while the other was a hyperbolic representation of velocity or the sea surface topography. The parameters of the Gaussian velocity model fit were a width parameter, a maximum velocity value, and the location of the maximum velocity. The parameters of the hyperbolic sea surface topography model were the width, the height jump, position, and sea surface topography at the center of the stream. Both models were used for the eight tracks and nine cycles studied. Comparisons were made between the width parameters, the maximum velocities, and the height jumps. Some of the parameter estimates were found to be highly (0.9) correlated when the hyperbolic sea surface topography fit was carried out, but such correlations were reduced for either the Gaussian velocity fits or the hyperbolic velocity model fit. A comparison of the parameters derived from 1-year TOPEX data showed good agreement with values derived by Kelly (1991) using 2.5 years of Geosat data near 38 deg N, 66 deg W longitude. Accuracy of the geoid undulations used in the calculations was of order of +/- 16 cm with the accuracy of a geoid undulation difference equal to +/- 15 cm over a 100-km line in areas with good terrestrial data coverage. This paper demonstrates that our knowledge or geoid undulations and undulation differences, in a portion of the Gulf Stream region, is sufficiently accurate to determine characteristics of the jet when used with TOPEX altimeter data. The method used here has not been shown to

Sediment yield estimation in mountain catchments of the Camastra reservoir, southern Italy: a comparison among different empirical methods

NASA Astrophysics Data System (ADS)

Lazzari, Maurizio; Danese, Maria; Gioia, Dario; Piccarreta, Marco

2013-04-01

Sedimentary budget estimation is an important topic for both scientific and social community, because it is crucial to understand both dynamics of orogenic belts and many practical problems, such as soil conservation and sediment accumulation in reservoir. Estimations of sediment yield or denudation rates in southern-central Italy are generally obtained by simple empirical relationships based on statistical regression between geomorphic parameters of the drainage network and the measured suspended sediment yield at the outlet of several drainage basins or through the use of models based on sediment delivery ratio or on soil loss equations. In this work, we perform a study of catchment dynamics and an estimation of sedimentary yield for several mountain catchments of the central-western sector of the Basilicata region, southern Italy. Sediment yield estimation has been obtained through both an indirect estimation of suspended sediment yield based on the Tu index (mean annual suspension sediment yield, Ciccacci et al., 1980) and the application of the Rusle (Renard et al., 1997) and the USPED (Mitasova et al., 1996) empirical methods. The preliminary results indicate a reliable difference between the RUSLE and USPED methods and the estimation based on the Tu index; a critical data analysis of results has been carried out considering also the present-day spatial distribution of erosion, transport and depositional processes in relation to the maps obtained from the application of those different empirical methods. The studied catchments drain an artificial reservoir (i.e. the Camastra dam), where a detailed evaluation of the amount of historical sediment storage has been collected. Sediment yield estimation obtained by means of the empirical methods have been compared and checked with historical data of sediment accumulation measured in the artificial reservoir of the Camastra dam. The validation of such estimations of sediment yield at the scale of large catchments

Rocket experiments for spectral estimation of electron density fine structure in the auroral and equatorial ionosphere and preliminary results

NASA Technical Reports Server (NTRS)

Tomei, B. A.; Smith, L. G.

1986-01-01

Sounding rockets equipped to monitor electron density and its fine structure were launched into the auroral and equatorial ionosphere in 1980 and 1983, respectively. The measurement electronics are based on the Langmuir probe and are described in detail. An approach to the spectral analysis of the density irregularities is addressed and a software algorithm implementing the approach is given. Preliminary results of the analysis are presented.

Traumatic Brain Injury Screening: Preliminary Findings in a US Army Brigade Combat Team

DTIC Science & Technology

2009-01-01

Screening: Preliminary Findings in a US Army Brigade Combat Team Heidi Terrio, MD, MPH; Lisa A. Brenner, PhD; Brian J. Ivins, MS; John M. Cho, MD; Katherine...Sheila Saliman and Lisa Betthauser is greatly appreciated. Corresponding author: Heidi Terrio, MD, MPH, 1853 O’Connell Blvd, Bldg 1042, Room 107, Fort...more mild TBI symptoms among injured soldiers with and without TBI (n = 1208)∗,† Parameter Adjusted 95% CI adjusted Variable estimate (β) SE β Wald P

Statistics of Sxy estimates

NASA Technical Reports Server (NTRS)

Freilich, M. H.; Pawka, S. S.

1987-01-01

The statistics of Sxy estimates derived from orthogonal-component measurements are examined. Based on results of Goodman (1957), the probability density function (pdf) for Sxy(f) estimates is derived, and a closed-form solution for arbitrary moments of the distribution is obtained. Characteristic functions are used to derive the exact pdf of Sxy(tot). In practice, a simple Gaussian approximation is found to be highly accurate even for relatively few degrees of freedom. Implications for experiment design are discussed, and a maximum-likelihood estimator for a posterior estimation is outlined.

Automatic Aircraft Structural Topology Generation for Multidisciplinary Optimization and Weight Estimation

NASA Technical Reports Server (NTRS)

Sensmeier, Mark D.; Samareh, Jamshid A.

2005-01-01

An approach is proposed for the application of rapid generation of moderate-fidelity structural finite element models of air vehicle structures to allow more accurate weight estimation earlier in the vehicle design process. This should help to rapidly assess many structural layouts before the start of the preliminary design phase and eliminate weight penalties imposed when actual structure weights exceed those estimated during conceptual design. By defining the structural topology in a fully parametric manner, the structure can be mapped to arbitrary vehicle configurations being considered during conceptual design optimization. A demonstration of this process is shown for two sample aircraft wing designs.

Estimation of suspended-sediment rating curves and mean suspended-sediment loads

USGS Publications Warehouse

Crawford, Charles G.

1991-01-01

A simulation study was done to evaluate: (1) the accuracy and precision of parameter estimates for the bias-corrected, transformed-linear and non-linear models obtained by the method of least squares; (2) the accuracy of mean suspended-sediment loads calculated by the flow-duration, rating-curve method using model parameters obtained by the alternative methods. Parameter estimates obtained by least squares for the bias-corrected, transformed-linear model were considerably more precise than those obtained for the non-linear or weighted non-linear model. The accuracy of parameter estimates obtained for the biascorrected, transformed-linear and weighted non-linear model was similar and was much greater than the accuracy obtained by non-linear least squares. The improved parameter estimates obtained by the biascorrected, transformed-linear or weighted non-linear model yield estimates of mean suspended-sediment load calculated by the flow-duration, rating-curve method that are more accurate and precise than those obtained for the non-linear model.

Mountaineer Commercial Scale Carbon Capture and Storage Project Topical Report: Preliminary Public Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guy Cerimele

2011-09-30

This Preliminary Public Design Report consolidates for public use nonproprietary design information on the Mountaineer Commercial Scale Carbon Capture & Storage project. The report is based on the preliminary design information developed during the Phase I - Project Definition Phase, spanning the time period of February 1, 2010 through September 30, 2011. The report includes descriptions and/or discussions for: (1) DOE's Clean Coal Power Initiative, overall project & Phase I objectives, and the historical evolution of DOE and American Electric Power (AEP) sponsored projects leading to the current project; (2) Alstom's Chilled Ammonia Process (CAP) carbon capture retrofit technology andmore » the carbon storage and monitoring system; (3) AEP's retrofit approach in terms of plant operational and integration philosophy; (4) The process island equipment and balance of plant systems for the CAP technology; (5) The carbon storage system, addressing injection wells, monitoring wells, system monitoring and controls logic philosophy; (6) Overall project estimate that includes the overnight cost estimate, cost escalation for future year expenditures, and major project risks that factored into the development of the risk based contingency; and (7) AEP's decision to suspend further work on the project at the end of Phase I, notwithstanding its assessment that the Alstom CAP technology is ready for commercial demonstration at the intended scale.« less

Preliminary design and economic investigations of Diffuser Augmented Wind Turbines (DAWT)

NASA Astrophysics Data System (ADS)

Foreman, K. M.

1981-12-01

A preferred design and configuration approach for the diffuser augmented wind turbines (DAWT) innovative wind energy conversion system is proposed. A preliminary economic assessment for limited production rates of units between 5 and 150 kw rated output was made. It is estimated that for farm and REA cooperative end users, the COE can range between 2 and 3.5 cents/kWh for sites with annual average wind speeds of 16 and 12 mph respectively and 150 kW rated units. No tax credits are included in these COE figures. For commercial end users of these 150 kW units the COE ranges between 4.0 and 6.5 cents/kWh for 16 and 12 mph sites. These estimates in 1979 dollars are lower than DOE goals set in 1978 for the rating size and end applications.

REFAME: Rain Estimation Using Forward Adjusted-Advection of Microwave Estimates

NASA Technical Reports Server (NTRS)

Behrangi, Ali; Imam, Bisher; Hsu, Kuolin; Sorooshian, Soroosh; Bellerby, Timothy J.

2009-01-01

Sensors flying on satellites provide the only practical means of estimating the precipitation that falls over the entire globe, particularly across the vast unpopulated expanses of Earth s oceans. The sensors that observe the Earth using microwave frequencies provide the best data, but currently these are mounted only on satellites flying in "low Earth orbit". Such satellites constantly move across the Earth s surface, providing snapshots of any given location every 12-36 hours. The entire constellation of low-orbit satellites numbers less than a dozen, and their orbits are not coordinated, so a location will frequently go two or more hours between snapshots. "Geosynchronous Earth orbit" (GEO) satellites continuously observe the same region of the globe, allowing them to provide very frequent pictures. For example, the "satellite movies" shown on television come from GEO satellites. However, the sensors available on GEO satellites cannot match the skill of the low-orbit microwave sensors in estimating precipitation. It is perhaps obvious that scientists should try to combine these very different kinds of data, taking advantage of the strengths of each, but this simple concept has proved to be a huge challenge. The scheme in this paper is "Lagrangian", meaning we follow the storm systems, rather than being tied to a fixed grid of boxes on the Earth s surface. Whenever a microwave snapshot occurs, we gladly use the resulting precipitation estimate. Then at all the times between the microwave snapshots we force the storm system to make a smooth transition from one snapshot s values to the next. We know that a lot more changes occur between the snapshots, but this smooth transition the best we can do with the microwave data alone. The key new contribution in this paper is that we also look at the relative variations in the GEO estimates during these in-between times and force the estimated changes in the precipitation to have similar variations. Preliminary testing

A Preliminary Shape Model of 27 Euterpe

NASA Astrophysics Data System (ADS)

Stephens, R.; Warner, B. D.; Megna, R.; Coley, D.

2011-10-01

We obtained dense rotational lightcurves for the Main-Belt asteroid (27) Euterpe during three apparitions in 2000, 2009 and 2010 with planned observations in the summer of 2011. These were combined with sparse lightcurve data from the USNO to determine a preliminary spin vector and model shape (see Durech et al. [2] for a discussion regarding the differences between dense and sparse data sets). The analysis suggests that Euterpe has albedo features making the determination of an unambiguous spin vector and model shape difficult. So far, Euterpe's near spherical shape, low inclination, pole within 30 degrees of the plane of the solar system, and possible albedo features cause multiple pole and shape solutions to be present.

Optimal combining of ground-based sensors for the purpose of validating satellite-based rainfall estimates

NASA Technical Reports Server (NTRS)

Krajewski, Witold F.; Rexroth, David T.; Kiriaki, Kiriakie

1991-01-01

Two problems related to radar rainfall estimation are described. The first part is a description of a preliminary data analysis for the purpose of statistical estimation of rainfall from multiple (radar and raingage) sensors. Raingage, radar, and joint radar-raingage estimation is described, and some results are given. Statistical parameters of rainfall spatial dependence are calculated and discussed in the context of optimal estimation. Quality control of radar data is also described. The second part describes radar scattering by ellipsoidal raindrops. An analytical solution is derived for the Rayleigh scattering regime. Single and volume scattering are presented. Comparison calculations with the known results for spheres and oblate spheroids are shown.

South San Francisco Bay 2004 topographic lidar survey: Data overview and preliminary quality assessment

USGS Publications Warehouse

Foxgrover, Amy C.; Jaffe, Bruce E.

2005-01-01

This report details the collection of lidar in South Bay, the ground-truthing efforts, preliminary accuracy assessments, and known limitations of the data set. We describe the data generated from the survey and how to obtain it. In addition, we present maps and sample imagery that provides a revealing look into the intricate topographic features of South Bay.

Preliminary calibration of the ACP safeguards neutron counter

NASA Astrophysics Data System (ADS)

Lee, T. H.; Kim, H. D.; Yoon, J. S.; Lee, S. Y.; Swinhoe, M.; Menlove, H. O.

2007-10-01

The Advanced Spent Fuel Conditioning Process (ACP), a kind of pyroprocess, has been developed at the Korea Atomic Energy Research Institute (KAERI). Since there is no IAEA safeguards criteria for this process, KAERI has developed a neutron coincidence counter to make it possible to perform a material control and accounting (MC&A) for its ACP materials for the purpose of a transparency in the peaceful uses of nuclear materials at KAERI. The test results of the ACP Safeguards Neutron Counter (ASNC) show a satisfactory performance for the Doubles count measurement with a low measurement error for its cylindrical sample cavity. The neutron detection efficiency is about 21% with an error of ±1.32% along the axial direction of the cavity. Using two 252Cf neutron sources, we obtained various parameters for the Singles and Doubles rates for the ASNC. The Singles, Doubles, and Triples rates for a 252Cf point source were obtained by using the MCNPX code and the results for the ft8 cap multiplicity tally option with the values of ɛ, fd, and ft measured with a strong source most closely match the measurement results to within a 1% error. A preliminary calibration curve for the ASNC was generated by using the point model equation relationship between 244Cm and 252Cf and the calibration coefficient for the non-multiplying sample is 2.78×10 5 (Doubles counts/s/g 244Cm). The preliminary calibration curves for the ACP samples were also obtained by using an MCNPX simulation. A neutron multiplication influence on an increase of the Doubles rate for a metal ingot and UO2 powder is clearly observed. These calibration curves will be modified and complemented, when hot calibration samples become available. To verify the validity of this calibration curve, a measurement of spent fuel standards for a known 244Cm mass will be performed in the near future.

Preliminary design of flight hardware for two-phase fluid research

NASA Technical Reports Server (NTRS)

Hustvedt, D. C.; Oonk, R. L.

1982-01-01

This study defined the preliminary designs of flight software for the Space Shuttle Orbiter for three two-phase fluid research experiments: (1) liquid reorientation - to study the motion of liquid in tanks subjected to small accelerations; (2) pool boiling - to study low-gravity boiling from horizontal cylinders; and (3) flow boiling - to study low-gravity forced flow boiling heat transfer and flow phenomena in a heated horizontal tube. The study consisted of eight major tasks: reassessment of the existing experiment designs, assessment of the Spacelab facility approach, assessment of the individual carry-on approach, selection of the preferred approach, preliminary design of flight hardware, safety analysis, preparation of a development plan, estimates of detailed design, fabrication and ground testing costs. The most cost effective design approach for the experiments is individual carry-ons in the Orbiter middeck. The experiments were designed to fit into one or two middeck lockers. Development schedules for the detailed design, fabrication and ground testing ranged from 15 1/2 to 18 months. Minimum costs (in 1981 dollars) ranged from $463K for the liquid reorientation experiment to $998K for the pool boiling experiment.

Integrating Eddy Covariance, Penman-Monteith and METRIC based Evapotranspiration estimates to generate high resolution space-time ET over the Brazos River Basin

NASA Astrophysics Data System (ADS)

Mbabazi, D.; Mohanty, B.; Gaur, N.

2017-12-01

Evapotranspiration (ET) is an important component of the water and energy balance and accounts for 60 -70% of precipitation losses. However, accurate estimates of ET are difficult to quantify at varying spatial and temporal scales. Eddy covariance methods estimate ET at high temporal resolutions but without capturing the spatial variation in ET within its footprint. On the other hand, remote sensing methods using Landsat imagery provide ET with high spatial resolution but low temporal resolution (16 days). In this study, we used both eddy covariance and remote sensing methods to generate high space-time resolution ET. Daily, monthly and seasonal ET estimates were obtained using the eddy covariance (EC) method, Penman-Monteith (PM) and Mapping Evapotranspiration with Internalized Calibration (METRIC) models to determine cotton and native prairie ET dynamics in the Brazos river basin characterized by varying hydro-climatic and geological gradients. Daily estimates of spatially distributed ET (30 m resolution) were generated using spatial autocorrelation and temporal interpolations between the EC flux variable footprints and METRIC ET for the 2016 and 2017 growing seasons. A comparison of the 2016 and 2017 preliminary daily ET estimates showed similar ET dynamics/trends among the EC, PM and METRIC methods, and 5-20% differences in seasonal ET estimates. This study will improve the spatial estimates of EC ET and temporal resolution of satellite derived ET thus providing better ET data for water use management.

Preliminary Results from Duplex Procedure for Obtain of Fe Based Materials for Automotive Applications

NASA Astrophysics Data System (ADS)

Crăciun, R. C.; Stanciu, S.; Geantă, V.; Voiculescu, I.; Manole, V.; Gârneţ, I. A.; Alexandru, A.; Cimpoesu, N.; Săndulache, F.

2017-06-01

Abstract Iron based materials still represent a high percentage from metallic materials used in industry, in general, and in automotive industry, in particular. In this case we used a duplex process in order to obtain the FeMnSiAl experimental alloy for a more efficient use of various units. In the first stage iron, manganese, silicon and aluminum were melted and mixed together using arc melting technology and for the second stage the alloy was re-melt for homogeneity in an induction furnace. Chemical composition, after each melting step, was analyzed using EDS Bruker detector for various areas and microstructural characterization using SEM, VegaTescan LMH II with SE detector, equipment. This alloy is proposed as a metallic approach of mechanical dumpers used in automotive industry for low and medium impact contacts.

The gas chromatography/mass spectrometry can be used for dose estimation in irradiated pork

NASA Astrophysics Data System (ADS)

D'Oca, M. C.; Bartolotta, A.; Cammilleri, M. C.; Giuffrida, S. A.; Parlato, A.; Di Noto, A. M.; Caracappa, S.

2009-07-01

Food safety can be improved using ionizing radiation to reduce food spoilage and to extend its shelf life. The gas chromatography/mass spectrometry (GC/MS) has been validated by the European Community as a powerful method to identify irradiated food containing fat. The preliminary goals of our research were: (i) to set up this method, based on the detection of radiation induced 2-dodecylcyclobutanones (2-DCB) in pork muscle samples and (ii) to check the microbiological efficacy of the treatment. The main objective was to render the GC/MS a quantitative technique for dose estimation, through the measurement of the 2-DCB concentration in the irradiated sample. Our results show that the reduction of the microbial population is substantially reduced even at 2 kGy, and that a clear identification of irradiated samples can be achieved also one month after irradiation at 2 kGy in frozen-stored samples. The 2-DCB concentration showed a linear dependence on dose in the range 1-10 kGy, no matter the origin of the sample; a unique calibration function was obtained, that allowed dose estimation in irradiated pork samples. A retrospective evaluation on the quality of the treatment could be carried out this way.

A method to estimate weight and dimensions of large and small gas turbine engines

NASA Technical Reports Server (NTRS)

Onat, E.; Klees, G. W.

1979-01-01

A computerized method was developed to estimate weight and envelope dimensions of large and small gas turbine engines within + or - 5% to 10%. The method is based on correlations of component weight and design features of 29 data base engines. Rotating components were estimated by a preliminary design procedure which is sensitive to blade geometry, operating conditions, material properties, shaft speed, hub tip ratio, etc. The development and justification of the method selected, and the various methods of analysis are discussed.

Flood frequency estimation by national-scale continuous hydrological simulations: an application in Great Britain

NASA Astrophysics Data System (ADS)

Formetta, Giuseppe; Stewart, Elizabeth; Bell, Victoria; Reynard, Nick

2017-04-01

Estimation of peak discharge for an assigned return period is a crucial issue in engineering hydrology. It is required for designing and managing hydraulic infrastructure such as dams, reservoirs and bridges. In the UK, the Flood Estimation Handbook (FEH) recommends the use of the index flood method to estimate the design flood as the product of a local scale factor (the index flood, IF) and a dimensionless regional growth factor (GF). For gauged catchments the IF is usually estimated as the median annual maximum flood (QMED), while for ungauged catchments it is computed through multiple linear regression models based on a set of morpho-climatic indices of the basin. The GF is estimated by fitting the annual maxima with the generalised logistic distribution (GL) using two methods depending on the record length and the target return period: single-site or pooled analysis. The single site-analysis estimates the GF from the annual maxima of the subject site alone; the pooled analysis uses data from a set of catchments hydrologically similar to the subject site. In this work estimates of floods up to 100-year return period obtained from the FEH approach are compared to those obtained using Grid-to-Grid, a continuous physically-based hydrological model. The model converts rainfall and potential evapotranspiration into river flows by modelling surface/sub-surface runoff, lateral water movements, and snow-pack. It is configured on a 1km2 grid resolution and it uses spatial datasets of topography, soil, and land cover. It was set up in Great Britain and has been evaluated for the period 1960-2014 in forward-mode (i.e. without parameter calibration) using daily meteorological forcing data. The modelled floods with a given return period (5,10, 30, 50, and 100 years) were computed from the modelled discharge annual maxima and compared to the FEH estimates for 100 catchments in Great Britain. Preliminary results suggest that there is a good agreement between modelled and

Ambient Assisted Living and ageing: preliminary results of RITA project.

PubMed

Aquilano, Michela; Cavallo, Filippo; Bonaccorsi, Manuele; Esposito, Raffaele; Rovini, Erika; Filippi, Massimo; Esposito, Dario; Dario, Paolo; Carrozza, Maria Chiara

2012-01-01

The ageing of population is a social phenomenon that most of worldwide countries are facing. They are, and will be even more in the future, indeed trying to find solutions for improving quality of life of their elderly citizens. The project RITA wants to demonstrate that an update of the current socio-medical services with an Ambient Assisted Living (AAL) approach could improve the service efficiency and the quality of life of both elderly and caregiver. This paper presents the preliminary results obtained in RITA.

Multi-Criterion Preliminary Design of a Tetrahedral Truss Platform

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey

1995-01-01

An efficient method is presented for multi-criterion preliminary design and demonstrated for a tetrahedral truss platform. The present method requires minimal analysis effort and permits rapid estimation of optimized truss behavior for preliminary design. A 14-m-diameter, 3-ring truss platform represents a candidate reflector support structure for space-based science spacecraft. The truss members are divided into 9 groups by truss ring and position. Design variables are the cross-sectional area of all members in a group, and are either 1, 3 or 5 times the minimum member area. Non-structural mass represents the node and joint hardware used to assemble the truss structure. Taguchi methods are used to efficiently identify key points in the set of Pareto-optimal truss designs. Key points identified using Taguchi methods are the maximum frequency, minimum mass, and maximum frequency-to-mass ratio truss designs. Low-order polynomial curve fits through these points are used to approximate the behavior of the full set of Pareto-optimal designs. The resulting Pareto-optimal design curve is used to predict frequency and mass for optimized trusses. Performance improvements are plotted in frequency-mass (criterion) space and compared to results for uniform trusses. Application of constraints to frequency and mass and sensitivity to constraint variation are demonstrated.

STRONG ORACLE OPTIMALITY OF FOLDED CONCAVE PENALIZED ESTIMATION.

PubMed

Fan, Jianqing; Xue, Lingzhou; Zou, Hui

2014-06-01

Folded concave penalization methods have been shown to enjoy the strong oracle property for high-dimensional sparse estimation. However, a folded concave penalization problem usually has multiple local solutions and the oracle property is established only for one of the unknown local solutions. A challenging fundamental issue still remains that it is not clear whether the local optimum computed by a given optimization algorithm possesses those nice theoretical properties. To close this important theoretical gap in over a decade, we provide a unified theory to show explicitly how to obtain the oracle solution via the local linear approximation algorithm. For a folded concave penalized estimation problem, we show that as long as the problem is localizable and the oracle estimator is well behaved, we can obtain the oracle estimator by using the one-step local linear approximation. In addition, once the oracle estimator is obtained, the local linear approximation algorithm converges, namely it produces the same estimator in the next iteration. The general theory is demonstrated by using four classical sparse estimation problems, i.e., sparse linear regression, sparse logistic regression, sparse precision matrix estimation and sparse quantile regression.

STRONG ORACLE OPTIMALITY OF FOLDED CONCAVE PENALIZED ESTIMATION

PubMed Central

Fan, Jianqing; Xue, Lingzhou; Zou, Hui

2014-01-01

Folded concave penalization methods have been shown to enjoy the strong oracle property for high-dimensional sparse estimation. However, a folded concave penalization problem usually has multiple local solutions and the oracle property is established only for one of the unknown local solutions. A challenging fundamental issue still remains that it is not clear whether the local optimum computed by a given optimization algorithm possesses those nice theoretical properties. To close this important theoretical gap in over a decade, we provide a unified theory to show explicitly how to obtain the oracle solution via the local linear approximation algorithm. For a folded concave penalized estimation problem, we show that as long as the problem is localizable and the oracle estimator is well behaved, we can obtain the oracle estimator by using the one-step local linear approximation. In addition, once the oracle estimator is obtained, the local linear approximation algorithm converges, namely it produces the same estimator in the next iteration. The general theory is demonstrated by using four classical sparse estimation problems, i.e., sparse linear regression, sparse logistic regression, sparse precision matrix estimation and sparse quantile regression. PMID:25598560

Gas-chromatography and UV-spectroscopy of Hymenoptera venoms obtained by trivial centrifugation.

PubMed

Fox, Eduardo G P; Xu, Meng; Wang, Lei; Chen, Li; Lu, Yong-Yue

2018-06-01

This paper summarises gas-chromatography (GC-MS) and preliminary UV-spectroscopy analyses data of fresh, unmodified venom of aculeate hymenopterans (ants, bees, wasps), mainly focusing on red imported fire ants. No solvents nor fractionation were used at any point, which is a novel approach to describing integral toxins cocktails as proposed by Fox et al. (2018a) [1] 10.1016/j.toxicon.2018.02.050 where these results are discussed in deeper details. Herein we focus on further characterising the obtained venom extracted through a novel approach. Pertaining raw data is accessible from Fox et al. (2018b) [2] 10.17632/cpnscw2gkc.1 including further relevant information regarding the used insects, machinery settings, chemical standards.

Optimal estimation for discrete time jump processes

NASA Technical Reports Server (NTRS)

Vaca, M. V.; Tretter, S. A.

1977-01-01

Optimum estimates of nonobservable random variables or random processes which influence the rate functions of a discrete time jump process (DTJP) are obtained. The approach is based on the a posteriori probability of a nonobservable event expressed in terms of the a priori probability of that event and of the sample function probability of the DTJP. A general representation for optimum estimates and recursive equations for minimum mean squared error (MMSE) estimates are obtained. MMSE estimates are nonlinear functions of the observations. The problem of estimating the rate of a DTJP when the rate is a random variable with a probability density function of the form cx super K (l-x) super m and show that the MMSE estimates are linear in this case. This class of density functions explains why there are insignificant differences between optimum unconstrained and linear MMSE estimates in a variety of problems.

23 CFR 645.109 - Preliminary engineering.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Preliminary engineering. 645.109 Section 645.109 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS UTILITIES Utility Relocations, Adjustments, and Reimbursement § 645.109 Preliminary engineering. (a) As...

23 CFR 645.109 - Preliminary engineering.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Preliminary engineering. 645.109 Section 645.109 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS UTILITIES Utility Relocations, Adjustments, and Reimbursement § 645.109 Preliminary engineering. (a) As...

23 CFR 645.109 - Preliminary engineering.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Preliminary engineering. 645.109 Section 645.109 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS UTILITIES Utility Relocations, Adjustments, and Reimbursement § 645.109 Preliminary engineering. (a) As...

23 CFR 645.109 - Preliminary engineering.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Preliminary engineering. 645.109 Section 645.109 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS UTILITIES Utility Relocations, Adjustments, and Reimbursement § 645.109 Preliminary engineering. (a) As...

23 CFR 645.109 - Preliminary engineering.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Preliminary engineering. 645.109 Section 645.109 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS UTILITIES Utility Relocations, Adjustments, and Reimbursement § 645.109 Preliminary engineering. (a) As...

Exsanguinated blood volume estimation using fractal analysis of digital images.

PubMed

Sant, Sonia P; Fairgrieve, Scott I

2012-05-01

The estimation of bloodstain volume using fractal analysis of digital images of passive blood stains is presented. Binary digital photos of bloodstains of known volumes (ranging from 1 to 7 mL), dispersed in a defined area, were subjected to image analysis using FracLac V. 2.0 for ImageJ. The box-counting method was used to generate a fractal dimension for each trial. A positive correlation between the generated fractal number and the volume of blood was found (R(2) = 0.99). Regression equations were produced to estimate the volume of blood in blind trials. An error rate ranging from 78% for 1 mL to 7% for 6 mL demonstrated that as the volume increases so does the accuracy of the volume estimation. This method used in the preliminary study proved that bloodstain patterns may be deconstructed into mathematical parameters, thus removing the subjective element inherent in other methods of volume estimation. © 2012 American Academy of Forensic Sciences.

Age and growth of round gobies in Lake Michigan, with preliminary mortality estimation

USGS Publications Warehouse

Huo, Bin; Madenjian, Charles P.; Xie, Cong X.; Zhao, Yingming; O'Brien, Timothy P.; Czesny, Sergiusz J.

2015-01-01

The round goby (Neogobius melanostomus) is a prevalent invasive species throughout Lake Michigan, as well as other Laurentian Great Lakes, yet little information is available on spatial variation in round goby growth within one body of water. Age and growth of round goby at three areas of Lake Michigan were studied by otolith analysis from a sample of 659 specimens collected from 2008 to 2012. Total length (TL) ranged from 48 to 131 mm for Sturgeon Bay, from 50 to 125 mm for Waukegan, and from 54 to 129 mm for Sleeping Bear Dunes. Ages ranged from 2 to 7 years for Sturgeon Bay, from 2 to 5 years for Waukegan, and from 2 to 6 years for Sleeping Bear Dunes. Area-specific and sex-specific body–otolith relationships were used to back-calculate estimates of total length at age, which were fitted to von Bertalanffy models to estimate growth rates. For both sexes, round gobies at Sleeping Bear Dunes and Waukegan grew significantly faster than those at Sturgeon Bay. However, round goby growth did not significantly differ between Sleeping Bear Dunes and Waukegan for either sex. At all three areas of Lake Michigan, males grew significantly faster than females. Based on catch curve analysis, estimates of annual mortality rates ranged from 0.79 to 0.84. These relatively high mortality rates suggested that round gobies may be under predatory control in Lake Michigan.

Estimating scatter in cone beam CT with striped ratio grids: A preliminary investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsieh, Scott, E-mail: sshsieh@stanford.edu

2016-09-15

Purpose: To propose a new method for estimating scatter in x-ray imaging. Conventional antiscatter grids reject scatter at an efficiency that is constant or slowly varying over the surface of the grid. A striped ratio antiscatter grid, composed of stripes that alternate between high and low grid ratio, could be used instead. Such a striped ratio grid would reduce scatter-to-primary ratio as a conventional grid would, but more importantly, the signal discontinuities at the boundaries of stripes can be used to estimate local scatter content. Methods: Signal discontinuities provide information on scatter, but are contaminated by variation in primary radiation.more » A nonlinear image processing algorithm is used to estimate the scatter content in the presence of primary variation. We emulated a striped ratio grid by imaging phantoms with two sequential CT scans, one with and one without a conventional grid. These two scans are processed together to mimic a striped ratio grid. This represents a best case limit of the striped ratio grid, in that the extent of grid ratio modulation is very high and the scatter contrast is maximized. Results: In a uniform cylinder, the striped ratio grid virtually eliminates cupping. Artifacts from scatter are improved in an anthropomorphic phantom. Some banding artifacts are induced by the striped ratio grid. Conclusions: Striped ratio grids could be a simple and effective evolution of conventional antiscatter grids. Construction and validation of a physical prototype remains an important future step.« less

Surveyor 3 Preliminary Science Results

NASA Technical Reports Server (NTRS)

1967-01-01

Surveyor III soft-landed on the Moon at 00:04 GMT on April 20, 1967. Data obtained have significantly increased our knowledge of the Moon. The Surveyor III spacecraft was similar to Surveyor I; the only major change in scientific instrumentation was the addition of a soil mechanics surface sampler. Surveyor III results at this preliminary evaluation of data give valuable information about the relation between the surface skin of under-dense material responsible for the photometric properties and the deeper layers of material whose properties resemble those of ordinary terrestrial soils. In addition, they provide new insight into the relation between the general lunar surface as seen by Surveyor I and the interior of a large subdued crater. The new results have also contributed to our understanding of the mechanism of downhill transport. Many critical questions cannot, however, be answered until final reduction of experimental data.

An Evaluation of Residual Feed Intake Estimates Obtained with Computer Models Versus Empirical Regression

USDA-ARS?s Scientific Manuscript database

Data on individual daily feed intake, bi-weekly BW, and carcass composition were obtained on 1,212 crossbred steers, in Cycle VII of the Germplasm Evaluation Project at the U.S. Meat Animal Research Center. Within animal regressions of cumulative feed intake and BW on linear and quadratic days on fe...

Preliminary Results from the NASA Orbiting Carbon Observatory-2 (OCO-2)

NASA Astrophysics Data System (ADS)

Crisp, D.; Eldering, A.; Gunson, M. R.

2014-12-01

The NASA Orbiting Carbon Observatory - 2 (OCO-2) was successfully launched from Vandenberg Air Force Base at 9:56:44 UTC on July 2, 2014. After a series of spacecraft checkout activities and orbit raising maneuvers, OCO-2 was inserted at the front of the 705-km Afternoon constellation (A-Train) on August 3rd. This presentation will summarize the science objectives, review the measurement approach, and introduce some preliminary data from the first few months of operation. OCO-2 was designed to return estimates of the column-averaged atmospheric carbon dioxide (CO2) dry air mole fraction (XCO2) with the precision, resolution, and coverage needed to quantify CO2 surface fluxes on regional scales. To meet these goals, it carries and points a 3-channel grating spectrometer that collects high resolution, co-bore-sighted spectra of reflected sunlight in the 765 nm O2 A-band and in the CO2 bands centered near 1610 and 2060 nm. Each channel records 24 spectra per second along a narrow (< 0.8-degree) track, returning about one million soundings each day. At least 10% of these soundings are expected to be sufficiently cloud free to yield full-column estimates of XCO2with single-sounding accuracies of 0.25 % on regional scales at monthly intervals. The instrument is calibrated using on-board sources and targets, the Moon, well-characterized surface sites (Pollock et al. this session), and comparisons with nearly-coincident observations from the Japanese Greenhouse gases Observing SATellite (GOSAT; Kuze et al. this session). Cloudy soundings are identified and screened out (Taylor et al. this session) and the remaining soundings are analyzed to yield spatially-resolved estimates of XCO2 and other geophysical products (c.f. Frankenberg et al. this session). OCO-2 XCO2 estimates are then validated against those from the Total Carbon Column Observing Network (TCCON) to assess their accuracy and precision (Wennberg et al. this session). Preliminary products from each step of this

Exoplanet Yield Estimation for Decadal Study Concepts using EXOSIMS

NASA Astrophysics Data System (ADS)

Morgan, Rhonda; Lowrance, Patrick; Savransky, Dmitry; Garrett, Daniel

2016-01-01

The anticipated upcoming large mission study concepts for the direct imaging of exo-earths present an exciting opportunity for exoplanet discovery and characterization. While these telescope concepts would also be capable of conducting a broad range of astrophysical investigations, the most difficult technology challenges are driven by the requirements for imaging exo-earths. The exoplanet science yield for these mission concepts will drive design trades and mission concept comparisons.To assist in these trade studies, the Exoplanet Exploration Program Office (ExEP) is developing a yield estimation tool that emphasizes transparency and consistent comparison of various design concepts. The tool will provide a parametric estimate of science yield of various mission concepts using contrast curves from physics-based model codes and Monte Carlo simulations of design reference missions using realistic constraints, such as solar avoidance angles, the observatory orbit, propulsion limitations of star shades, the accessibility of candidate targets, local and background zodiacal light levels, and background confusion by stars and galaxies. The python tool utilizes Dmitry Savransky's EXOSIMS (Exoplanet Open-Source Imaging Mission Simulator) design reference mission simulator that is being developed for the WFIRST Preliminary Science program. ExEP is extending and validating the tool for future mission concepts under consideration for the upcoming 2020 decadal review. We present a validation plan and preliminary yield results for a point design.

Comparison of TOPEX/Poseidon orbit determination solutions obtained by the Goddard Space Flight Center Flight Dynamics Division and Precision Orbit Determination Teams

NASA Technical Reports Server (NTRS)

Doll, C.; Mistretta, G.; Hart, R.; Oza, D.; Cox, C.; Nemesure, M.; Bolvin, D.; Samii, Mina V.

1993-01-01

Orbit determination results are obtained by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) using the Goddard Trajectory Determination System (GTDS) and a real-time extended Kalman filter estimation system to process Tracking Data and Relay Satellite (TDRS) System (TDRSS) measurements in support of the Ocean Topography Experiment (TOPEX)/Poseidon spacecraft navigation and health and safety operations. GTDS is the operational orbit determination system used by the FDD, and the extended Kalman fliter was implemented in an analysis prototype system, the Real-Time Orbit Determination System/Enhanced (RTOD/E). The Precision Orbit Determination (POD) team within the GSFC Space Geodesy Branch generates an independent set of high-accuracy trajectories to support the TOPEX/Poseidon scientific data. These latter solutions use the Geodynamics (GEODYN) orbit determination system with laser ranging tracking data. The TOPEX/Poseidon trajectories were estimated for the October 22 - November 1, 1992, timeframe, for which the latest preliminary POD results were available. Independent assessments were made of the consistencies of solutions produced by the batch and sequential methods. The batch cases were assessed using overlap comparisons, while the sequential cases were assessed with covariances and the first measurement residuals. The batch least-squares and forward-filtered RTOD/E orbit solutions were compared with the definitive POD orbit solutions. The solution differences were generally less than 10 meters (m) for the batch least squares and less than 18 m for the sequential estimation solutions. The differences among the POD, GTDS, and RTOD/E solutions can be traced to differences in modeling and tracking data types, which are being analyzed in detail.

Preliminary Outcomes from an Integrated Pediatric Mental Health Outpatient Clinic.

PubMed

Maslow, Gary R; Banny, Adrienne; Pollock, McLean; Stefureac, Kristen; Rosa, Kendra; Walter, Barbara Keith; Hobbs Knutson, Katherine; Lucas, Joseph; Heilbron, Nicole

2017-10-01

An estimated 1 in 5 children in the United States meet criteria for a diagnosable mental disorder, yet fewer than 20% receive mental health services. Unmet need for psychiatric treatment may contribute to patterns of increasing use of the emergency department. This article describes an integrated pediatric evaluation center designed to prevent the need for treatment in emergency settings by increasing access to timely and appropriate care for emergent and critical mental health needs. Preliminary results showed that the center provided rapid access to assessment and treatment services for children and adolescents presenting with a wide range of psychiatric concerns. Copyright © 2017 Elsevier Inc. All rights reserved.

Preliminary Modelling of Radiation Levels at the Fermilab PIP-II Linac

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lari, L.; Cerutti, F.; Esposito, L. S.

PIP-II is the Fermilab's flagship project for providing powerful, high-intensity proton beams to the laboratory's experiments. The heart of PIP-II is an 800-MeV superconducting linac accelerator. It will be located in a new tunnel with new service buildings and connected to the present Booster through a new transfer line. To support the design of civil engineering and mechanical integration, this paper provides preliminary estimation of radiation level in the gallery at an operational beam loss limit of 0.1 W/m, by means of Monte Carlo calculations with FLUKA and MARS15 codes.

7 CFR 3430.32 - Preliminary application review.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., EDUCATION, AND EXTENSION SERVICE, DEPARTMENT OF AGRICULTURE COMPETITIVE AND NONCOMPETITIVE NON-FORMULA... Evaluation § 3430.32 Preliminary application review. Prior to technical examination, a preliminary review...

Preliminary design for a maglev development facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coffey, H.T.; He, J.L.; Chang, S.L.

1992-04-01

A preliminary design was made of a national user facility for evaluating magnetic-levitation (maglev) technologies in sizes intermediate between laboratory experiments and full-scale systems. A technical advisory committee was established and a conference was held to obtain advice on the potential requirements of operational systems and how the facility might best be configured to test these requirements. The effort included studies of multiple concepts for levitating, guiding, and propelling maglev vehicles, as well as the controls, communications, and data-acquisition and -reduction equipment that would be required in operating the facility. Preliminary designs for versatile, dual 2-MVA power supplies capable ofmore » powering attractive or repulsive systems were developed. Facility site requirements were identified. Test vehicles would be about 7.4 m (25 ft) long, would weigh form 3 to 7 metric tons, and would operate at speeds up to 67 m/s (150 mph) on a 3.3-km (2.05-mi) elevated guideway. The facility would utilize modular vehicles and guideways, permitting the substitution of levitation, propulsion, and guideway components of different designs and materials for evaluation. The vehicle would provide a test cell in which individual suspension or propulsion components or subsystems could be tested under realistic conditions. The system would allow economical evaluation of integrated systems under varying weather conditions and in realistic geometries.« less

Historical review of and current progress in coal-resource estimation in the United States.

USGS Publications Warehouse

Wood, G.H.

1981-01-01

Nine estimates of US coal resources have been published in the past 71yr. Although many details of these estimates differ markedly, those for 1913, 1922, and 1974 are surprisingly similar. Some differences are due to increased data, others reflect changes in terminology, definitions, criteria, guidelines, and methodologies. Thus many early estimates are not particularly useful in modern resource assessments. Preliminary definitions that are being prepared in 1980 by the US Geological Survey are compared with those published in 1976 and currently in use. Anticipated results of the new definitions are: 1) to lessen existing confusion about estimation procedures; 2) to make such procedures easier and more precise; 3) to promote use of a commonly accepted terminology accompanied by standardized definitions, criteria, guidelines, and methodologies for estimating resources. -Author

33 CFR 116.10 - Preliminary review.

Code of Federal Regulations, 2013 CFR

2013-07-01

... on a bridge's accident history or other criteria, to conduct a Preliminary Investigation. (c) The... Section 116.10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES ALTERATION OF UNREASONABLY OBSTRUCTIVE BRIDGES § 116.10 Preliminary review. (a) Upon receipt of a written...

33 CFR 116.10 - Preliminary review.

Code of Federal Regulations, 2010 CFR

2010-07-01

... on a bridge's accident history or other criteria, to conduct a Preliminary Investigation. (c) The... Section 116.10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES ALTERATION OF UNREASONABLY OBSTRUCTIVE BRIDGES § 116.10 Preliminary review. (a) Upon receipt of a written...

33 CFR 116.10 - Preliminary review.

Code of Federal Regulations, 2012 CFR

2012-07-01

... on a bridge's accident history or other criteria, to conduct a Preliminary Investigation. (c) The... Section 116.10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES ALTERATION OF UNREASONABLY OBSTRUCTIVE BRIDGES § 116.10 Preliminary review. (a) Upon receipt of a written...

33 CFR 116.10 - Preliminary review.

Code of Federal Regulations, 2011 CFR

2011-07-01

... on a bridge's accident history or other criteria, to conduct a Preliminary Investigation. (c) The... Section 116.10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES ALTERATION OF UNREASONABLY OBSTRUCTIVE BRIDGES § 116.10 Preliminary review. (a) Upon receipt of a written...

33 CFR 116.10 - Preliminary review.

Code of Federal Regulations, 2014 CFR

2014-07-01

... on a bridge's accident history or other criteria, to conduct a Preliminary Investigation. (c) The... Section 116.10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES ALTERATION OF UNREASONABLY OBSTRUCTIVE BRIDGES § 116.10 Preliminary review. (a) Upon receipt of a written...

Estimation of crown closure from AVIRIS data using regression analysis

NASA Technical Reports Server (NTRS)

Staenz, K.; Williams, D. J.; Truchon, M.; Fritz, R.

1993-01-01

Crown closure is one of the input parameters used for forest growth and yield modelling. Preliminary work by Staenz et al. indicates that imaging spectrometer data acquired with sensors such as the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) have some potential for estimating crown closure on a stand level. The objectives of this paper are: (1) to establish a relationship between AVIRIS data and the crown closure derived from aerial photography of a forested test site within the Interior Douglas Fir biogeoclimatic zone in British Columbia, Canada; (2) to investigate the impact of atmospheric effects and the forest background on the correlation between AVIRIS data and crown closure estimates; and (3) to improve this relationship using multiple regression analysis.

Advanced space engine preliminary design

NASA Technical Reports Server (NTRS)

Cuffe, J. P. B.; Bradie, R. E.

1973-01-01

A preliminary design was completed for an O2/H2, 89 kN (20,000 lb) thrust staged combustion rocket engine that has a single-bell nozzle with an overall expansion ratio of 400:1. The engine has a best estimate vacuum specific impulse of 4623.8 N-s/kg (471.5 sec) at full thrust and mixture ratio = 6.0. The engine employs gear-driven, low pressure pumps to provide low NPSH capability while individual turbine-driven, high-speed main pumps provide the system pressures required for high-chamber pressure operation. The engine design dry weight for the fixed-nozzle configuration is 206.9 kg (456.3 lb). Engine overall length is 234 cm (92.1 in.). The extendible nozzle version has a stowed length of 141.5 cm (55.7 in.). Critical technology items in the development of the engine were defined. Development program plans and their costs for development, production, operation, and flight support of the ASE were established for minimum cost and minimum time programs.

Main results and experience obtained on Mir space station and experiment program for Russian segment of ISS.

PubMed

Utkin, V F; Lukjashchenko, V I; Borisov, V V; Suvorov, V V; Tsymbalyuk, M M

2003-07-01

This article presents main scientific and practical results obtained in course of scientific and applied research and experiments on Mir space station. Based on Mir experience, processes of research program formation for the Russian Segment of the ISS are briefly described. The major trends of activities planned in the frames of these programs as well as preliminary results of increment research programs implementation in the ISS' first missions are also presented. c2003 Elsevier Science Ltd. All rights reserved.

Estimating cell populations

NASA Technical Reports Server (NTRS)

White, B. S.; Castleman, K. R.

1981-01-01

An important step in the diagnosis of a cervical cytology specimen is estimating the proportions of the various cell types present. This is usually done with a cell classifier, the error rates of which can be expressed as a confusion matrix. We show how to use the confusion matrix to obtain an unbiased estimate of the desired proportions. We show that the mean square error of this estimate depends on a 'befuddlement matrix' derived from the confusion matrix, and how this, in turn, leads to a figure of merit for cell classifiers. Finally, we work out the two-class problem in detail and present examples to illustrate the theory.

Spring Small Grains Area Estimation

NASA Technical Reports Server (NTRS)

Palmer, W. F.; Mohler, R. J.

1986-01-01

SSG3 automatically estimates acreage of spring small grains from Landsat data. Report describes development and testing of a computerized technique for using Landsat multispectral scanner (MSS) data to estimate acreage of spring small grains (wheat, barley, and oats). Application of technique to analysis of four years of data from United States and Canada yielded estimates of accuracy comparable to those obtained through procedures that rely on trained analysis.

Preliminary thermal architecture of the X-IFU instrument dewar

NASA Astrophysics Data System (ADS)

Charles, Ivan; Daniel, Christophe; André, Jérome; Duband, Lionel; Duval, Jean-Marc; den Hartog, Roland; Mitsuda, Kazuhisa; Shinozaki, Keisuke; van Weers, Henk; Yamasaki, Noriko Y.

2016-07-01

The ESA Athena mission will implement 2 instruments to study the hot and energetic universe. The X-ray Integral Field Unit (X-IFU) will provide spatially resolved high resolution spectroscopy. This high energy resolution of 2.5 eV at 7 keV could be achieved thanks to TES (Transition Edge Sensor) detectors that need to be cooled to very low temperature. To obtain the required 50 mK temperature level, a careful design of the cryostat and of the cooling chain including different technologies in cascade is needed. The preliminary cryogenic architecture of the X-IFU instrument that fulfils the TES detector thermal requirements is described. In particular, the thermal design of the detector focal plane assembly (FPA), that uses three temperature stages (from 2 K to 50 mK) to limit the thermal loads on the lowest temperature stage, is described. The baseline cooling chain is based on European and Japanese mechanical coolers (Stirling, Pulse tube and Joule Thomson coolers) that precool a sub Kelvin cooler made of a 3He sorption cooler coupled with a small ADR (Adiabatic Demagnetization Refrigerator). Preliminary thermal budgets of the X-IFU cryostat are presented and discussed regarding cooling chain performances.

Preliminary body-wave analysis of the St. Elias, Alaska, earthquake of February 28, 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boatwright, J.

1980-04-01

Employing a new technique for the body-wave analysis of shallow-focus earthquakes, we have made a preliminary analysis of the St. Elias, Alaska, earthquake of February 28, 1979, using five long-period P and S waves recorded at three WWSSN stations and at Palisades, New York. Using a well determined focal mechanism and an average source depth of approx. = 11 km, the interference of the depth phases (i.e., pP and sP, or sS) has been deconvolved from the recorded pulse shapes to obtain velocity and displacement pulse shapes as they would appear if the earthquake had occurred within an infinite medium.more » These approximate whole space pulse shapes indicate that the rupture contained three distinct subevents as well as a small initial event which preceded this subevent sequence by about 7 sec. From the pulse rise times of the subevents, their rupture lengths are estimated as 12, 27, and 17 km, assuming that the subevent rupture velocity was 3 km/sec. Overall, the earthquake ruptured approx. = 60 km to the southeast with an average rupture velocity of 2.2 km/sec. The cumulative body-wave moment for the whole event, 1.2 x 10/sup 27/ dyne-cm, is substantially smaller than the surface-wave moments reported by Lahr et al. (1979) of 5 x 10/sup 27/ dyne-cm. The moments of the subevents are estimated to be 0.6, 3.2, and 7.5 x 10/sup 26/ dyne-cm, respectively.« less

76 FR 67146 - Stainless Steel Butt-Weld Pipe Fittings From Italy; Extension of Time Limit for Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

... DEPARTMENT OF COMMERCE International Trade Administration [A-475-828] Stainless Steel Butt-Weld... antidumping duty order on stainless steel butt-weld pipe fittings from Italy in the Federal Register. See... preliminary results of this review within the original time frame because it needs to obtain additional...

19 CFR 202.3 - Preliminary inquiry.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Preliminary inquiry. 202.3 Section 202.3 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS OF COSTS OF PRODUCTION § 202.3 Preliminary inquiry. Upon the receipt of an application properly filed, the...

19 CFR 202.3 - Preliminary inquiry.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 3 2011-04-01 2011-04-01 false Preliminary inquiry. 202.3 Section 202.3 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS OF COSTS OF PRODUCTION § 202.3 Preliminary inquiry. Upon the receipt of an application properly filed, the...

19 CFR 202.3 - Preliminary inquiry.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 3 2014-04-01 2014-04-01 false Preliminary inquiry. 202.3 Section 202.3 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS OF COSTS OF PRODUCTION § 202.3 Preliminary inquiry. Upon the receipt of an application properly filed, the...

19 CFR 202.3 - Preliminary inquiry.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 3 2012-04-01 2012-04-01 false Preliminary inquiry. 202.3 Section 202.3 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS OF COSTS OF PRODUCTION § 202.3 Preliminary inquiry. Upon the receipt of an application properly filed, the...

19 CFR 202.3 - Preliminary inquiry.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 3 2013-04-01 2013-04-01 false Preliminary inquiry. 202.3 Section 202.3 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION NONADJUDICATIVE INVESTIGATIONS INVESTIGATIONS OF COSTS OF PRODUCTION § 202.3 Preliminary inquiry. Upon the receipt of an application properly filed, the...

18 CFR 154.105 - Preliminary statement.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., DEPARTMENT OF ENERGY REGULATIONS UNDER NATURAL GAS ACT RATE SCHEDULES AND TARIFFS Form and Composition of Tariff § 154.105 Preliminary statement. The preliminary statement must contain a brief general description of the company's operations and may also contain a general explanation of its policies and...

40 CFR 158.345 - Preliminary analysis.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Preliminary analysis. 158.345 Section 158.345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.345 Preliminary analysis. (a) If the product is produced by...

40 CFR 158.345 - Preliminary analysis.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Preliminary analysis. 158.345 Section 158.345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.345 Preliminary analysis. (a) If the product is produced by...

40 CFR 158.345 - Preliminary analysis.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Preliminary analysis. 158.345 Section 158.345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.345 Preliminary analysis. (a) If the product is produced by...

40 CFR 158.345 - Preliminary analysis.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Preliminary analysis. 158.345 Section 158.345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.345 Preliminary analysis. (a) If the product is produced by...

40 CFR 158.345 - Preliminary analysis.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Preliminary analysis. 158.345 Section 158.345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.345 Preliminary analysis. (a) If the product is produced by...

Peak Seeking Control for Reduced Fuel Consumption with Preliminary Flight Test Results

NASA Technical Reports Server (NTRS)

Brown, Nelson

2012-01-01

The Environmentally Responsible Aviation project seeks to accomplish the simultaneous reduction of fuel burn, noise, and emissions. A project at NASA Dryden Flight Research Center is contributing to ERAs goals by exploring the practical application of real-time trim configuration optimization for enhanced performance and reduced fuel consumption. This peak-seeking control approach is based on Newton-Raphson algorithm using a time-varying Kalman filter to estimate the gradient of the performance function. In real-time operation, deflection of symmetric ailerons, trailing-edge flaps, and leading-edge flaps of a modified F-18 are directly optimized, and the horizontal stabilators and angle of attack are indirectly optimized. Preliminary results from three research flights are presented herein. The optimization system found a trim configuration that required approximately 3.5% less fuel flow than the baseline trim at the given flight condition. The algorithm consistently rediscovered the solution from several initial conditions. These preliminary results show the algorithm has good performance and is expected to show similar results at other flight conditions and aircraft configurations.

Preliminary design of an advanced Stirling system for terrestrial solar energy conversion

NASA Astrophysics Data System (ADS)

White, M. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

A preliminary design was generated for an advanced Stirling conversion system (ASCS) that will be capable of delivering about 25 kW of electric power to an electric utility grid. Stirling engines are being evaluated for terrestrial solar applications. A two-year task to complete detailed design, fabrication, assembly and testing of an ASCS prototype began in April, 1990. The ASCS is designed to deliver maximum power per year over a range of solar inputs with a design life of 30 years (60,000 h). The ACSC has a long-term cost goal of about $450 per kilowatt, exclusive of the 11-m parabolic dish concentrator. The proposed system includes a Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator. The major thrusts of the preliminary design are described, including material selection for the hot-end components, heat transport system (reflux pool boiler) design, system thermal response, improved manufacturability, FMECA/FTA analysis, updated manufacturing cost estimate, and predicted system performance.

Preliminary design of an advanced Stirling system for terrestrial solar energy conversion

NASA Technical Reports Server (NTRS)

White, M. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

1990-01-01

A preliminary design was generated for an advanced Stirling conversion system (ASCS) that will be capable of delivering about 25 kW of electric power to an electric utility grid. Stirling engines are being evaluated for terrestrial solar applications. A two-year task to complete detailed design, fabrication, assembly and testing of an ASCS prototype began in April, 1990. The ASCS is designed to deliver maximum power per year over a range of solar inputs with a design life of 30 years (60,000 h). The ACSC has a long-term cost goal of about $450 per kilowatt, exclusive of the 11-m parabolic dish concentrator. The proposed system includes a Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator. The major thrusts of the preliminary design are described, including material selection for the hot-end components, heat transport system (reflux pool boiler) design, system thermal response, improved manufacturability, FMECA/FTA analysis, updated manufacturing cost estimate, and predicted system performance.

Concentrating solar collector subsystem: Preliminary design package

NASA Technical Reports Server (NTRS)

1977-01-01

Preliminary design data are presented for a concentrating solar collector including an attitude controller. Provided are schedules, technical status, all documents required for preliminary design, and other program activities.

Restoration of gait for spinal cord injury patients using HAL with intention estimator for preferable swing speed.

PubMed

Tsukahara, Atsushi; Hasegawa, Yasuhisa; Eguchi, Kiyoshi; Sankai, Yoshiyuki

2015-03-01

This paper proposes a novel gait intention estimator for an exoskeleton-wearer who needs gait support owing to walking impairment. The gait intention estimator not only detects the intention related to the start of the swing leg based on the behavior of the center of ground reaction force (CoGRF), but also infers the swing speed depending on the walking velocity. The preliminary experiments categorized into two stages were performed on a mannequin equipped with the exoskeleton robot [Hybrid Assistive Limb: (HAL)] including the proposed estimator. The first experiment verified that the gait support system allowed the mannequin to walk properly and safely. In the second experiment, we confirmed the differences in gait characteristics attributed to the presence or absence of the proposed swing speed profile. As a feasibility study, we evaluated the walking capability of a severe spinal cord injury patient supported by the system during a 10-m walk test. The results showed that the system enabled the patient to accomplish a symmetrical walk from both spatial and temporal standpoints while adjusting the speed of the swing leg. Furthermore, the critical differences of gait between our system and a knee-ankle-foot orthosis were obtained from the CoGRF distribution and the walking time. Through the tests, we demonstrated the effectiveness and practical feasibility of the gait support algorithms.

Development of methodologies for the estimation of thermal properties associated with aerospace vehicles

NASA Technical Reports Server (NTRS)

Scott, Elaine P.

1993-01-01

Thermal stress analyses are an important aspect in the development of aerospace vehicles such as the National Aero-Space Plane (NASP) and the High-Speed Civil Transport (HSCT) at NASA-LaRC. These analyses require knowledge of the temperature within the structures which consequently necessitates the need for thermal property data. The initial goal of this research effort was to develop a methodology for the estimation of thermal properties of aerospace structural materials at room temperature and to develop a procedure to optimize the estimation process. The estimation procedure was implemented utilizing a general purpose finite element code. In addition, an optimization procedure was developed and implemented to determine critical experimental parameters to optimize the estimation procedure. Finally, preliminary experiments were conducted at the Aircraft Structures Branch (ASB) laboratory.

Development of methodologies for the estimation of thermal properties associated with aerospace vehicles

NASA Astrophysics Data System (ADS)

Scott, Elaine P.

1993-12-01

Thermal stress analyses are an important aspect in the development of aerospace vehicles such as the National Aero-Space Plane (NASP) and the High-Speed Civil Transport (HSCT) at NASA-LaRC. These analyses require knowledge of the temperature within the structures which consequently necessitates the need for thermal property data. The initial goal of this research effort was to develop a methodology for the estimation of thermal properties of aerospace structural materials at room temperature and to develop a procedure to optimize the estimation process. The estimation procedure was implemented utilizing a general purpose finite element code. In addition, an optimization procedure was developed and implemented to determine critical experimental parameters to optimize the estimation procedure. Finally, preliminary experiments were conducted at the Aircraft Structures Branch (ASB) laboratory.

Bubble fusion: Preliminary estimates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krakowski, R.A.

1995-02-01

The collapse of a gas-filled bubble in disequilibrium (i.e., internal pressure {much_lt} external pressure) can occur with a significant focusing of energy onto the entrapped gas in the form of pressure-volume work and/or acoustical shocks; the resulting heating can be sufficient to cause ionization and the emission of atomic radiations. The suggestion that extreme conditions necessary for thermonuclear fusion to occur may be possible has been examined parametrically in terms of the ratio of initial bubble pressure relative to that required for equilibrium. In this sense, the disequilibrium bubble is viewed as a three-dimensional ``sling shot`` that is ``loaded`` tomore » an extent allowed by the maximum level of disequilibrium that can stably be achieved. Values of this disequilibrium ratio in the range 10{sup {minus}5}--10{sup {minus}6} are predicted by an idealized bubble-dynamics model as necessary to achieve conditions where nuclear fusion of deuterium-tritium might be observed. Harmonic and aharmonic pressurizations/decompressions are examined as means to achieve the required levels of disequilibrium required to create fusion conditions. A number of phenomena not included in the analysis reported herein could enhance or reduce the small levels of nuclear fusions predicted.« less

Assessment of dietary intake of flavouring substances within the procedure for their safety evaluation: advantages and limitations of estimates obtained by means of a per capita method.

PubMed

Arcella, D; Leclercq, C

2005-01-01

The procedure for the safety evaluation of flavourings adopted by the European Commission in order to establish a positive list of these substances is a stepwise approach which was developed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and amended by the Scientific Committee on Food. Within this procedure, a per capita amount based on industrial poundage data of flavourings, is calculated to estimate the dietary intake by means of the maximised survey-derived daily intake (MSDI) method. This paper reviews the MSDI method in order to check if it can provide conservative intake estimates as needed at the first steps of a stepwise procedure. Scientific papers and opinions dealing with the MSDI method were reviewed. Concentration levels reported by the industry were compared with estimates obtained with the MSDI method. It appeared that, in some cases, these estimates could be orders of magnitude (up to 5) lower than those calculated considering concentration levels provided by the industry and regular consumption of flavoured foods and beverages. A critical review of two studies which had been used to support the statement that MSDI is a conservative method for assessing exposure to flavourings among high consumers was performed. Special attention was given to the factors that affect exposure at high percentiles, such as brand loyalty and portion sizes. It is concluded that these studies may not be suitable to validate the MSDI method used to assess intakes of flavours by European consumers due to shortcomings in the assumptions made and in the data used. Exposure assessment is an essential component of risk assessment. The present paper suggests that the MSDI method is not sufficiently conservative. There is therefore a clear need for either using an alternative method to estimate exposure to flavourings in the procedure or for limiting intakes to the levels at which the safety was assessed.

Apollo 17 traverse gravimeter experiment /Preliminary results/

NASA Technical Reports Server (NTRS)

Talwani, M.; Kahle, H.-G.

1976-01-01

Preliminary results of the traverse gravimeter experiment successfully performed during the Apollo 17 mission are discussed. An earth-moon gravity tie was established. On the basis of several readings, a gravity value of 162,695 + or - 5 mgal was obtained at the lunar-module landing site in the Taurus-Littrow valley. Free-air and Bouguer corrections were applied to the gravity data. The resultant Bouguer anomaly, analyzed with a two-dimensional approximation, shows a relative gravity maximum of about 25 to 30 mgal over the Taurus-Littrow valley. This maximum is interpreted in terms of a 1-km-thick block of basalt flow with a positive density contrast of 0.8 g/cu cm relative to the highland material on either side.

Preliminary Analysis of Ground-based Orbit Determination Accuracy for the Wide Field Infrared Survey Telescope (WFIRST)

NASA Technical Reports Server (NTRS)

Sease, Brad

2017-01-01

The Wide Field Infrared Survey Telescope is a 2.4-meter telescope planned for launch to the Sun-Earth L2 point in 2026. This paper details a preliminary study of the achievable accuracy for WFIRST from ground-based orbit determination routines. The analysis here is divided into two segments. First, a linear covariance analysis of early mission and routine operations provides an estimate of the tracking schedule required to meet mission requirements. Second, a simulated operations scenario gives insight into the expected behavior of a daily Extended Kalman Filter orbit estimate over the first mission year given a variety of potential momentum unloading schemes.

Preliminary Analysis of Ground-Based Orbit Determination Accuracy for the Wide Field Infrared Survey Telescope (WFIRST)

NASA Technical Reports Server (NTRS)

Sease, Bradley; Myers, Jessica; Lorah, John; Webster, Cassandra

2017-01-01

The Wide Field Infrared Survey Telescope is a 2.4-meter telescope planned for launch to the Sun-Earth L2 point in 2026. This paper details a preliminary study of the achievable accuracy for WFIRST from ground-based orbit determination routines. The analysis here is divided into two segments. First, a linear covariance analysis of early mission and routine operations provides an estimate of the tracking schedule required to meet mission requirements. Second, a simulated operations'' scenario gives insight into the expected behavior of a daily Extended Kalman Filter orbit estimate over the first mission year given a variety of potential momentum unloading schemes.

Preliminary survey of markets and prices of forest products in the Del-Mar-Va Peninsula

Treesearch

George E. Doverspike

1949-01-01

This preliminary survey was designed to explore the present methods of marketing farm products and the problems involved in collecting price information about primary forest products. No attempt was made to initiate a permanent price-reporting service, since that was beyond the scope of the survey. However, certain price information was obtained; it is shown in table 2...

32 CFR 644.30 - Preliminary real estate work.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Preliminary real estate work. 644.30 Section 644... PROPERTY REAL ESTATE HANDBOOK Project Planning Military (army and Air Force) and Other Federal Agencies § 644.30 Preliminary real estate work. (a) Preliminary real estate work is defined as that action taken...

32 CFR 644.30 - Preliminary real estate work.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 4 2014-07-01 2013-07-01 true Preliminary real estate work. 644.30 Section 644... PROPERTY REAL ESTATE HANDBOOK Project Planning Military (army and Air Force) and Other Federal Agencies § 644.30 Preliminary real estate work. (a) Preliminary real estate work is defined as that action taken...

32 CFR 644.30 - Preliminary real estate work.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 4 2012-07-01 2011-07-01 true Preliminary real estate work. 644.30 Section 644... PROPERTY REAL ESTATE HANDBOOK Project Planning Military (army and Air Force) and Other Federal Agencies § 644.30 Preliminary real estate work. (a) Preliminary real estate work is defined as that action taken...

32 CFR 644.30 - Preliminary real estate work.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 4 2013-07-01 2013-07-01 false Preliminary real estate work. 644.30 Section 644... PROPERTY REAL ESTATE HANDBOOK Project Planning Military (army and Air Force) and Other Federal Agencies § 644.30 Preliminary real estate work. (a) Preliminary real estate work is defined as that action taken...

32 CFR 644.30 - Preliminary real estate work.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 4 2011-07-01 2011-07-01 false Preliminary real estate work. 644.30 Section 644... PROPERTY REAL ESTATE HANDBOOK Project Planning Military (army and Air Force) and Other Federal Agencies § 644.30 Preliminary real estate work. (a) Preliminary real estate work is defined as that action taken...

Preliminary studies of electromagnetic sounding of cometary nuclei

NASA Technical Reports Server (NTRS)

Gabriel, A.; Warne, L.; Bednarczyk, S.; Elachi, C.

1978-01-01

The internal structure of a comet could be determined with a spacecraft borne electromagnetic sounder. A dielectric profile of the comet could be produced in direct analogy with terrestrial glacier and ice sheet sounding experiments. This profile would allow the detection of a rocky core or ice layers if they exist, just as layers in the ice and the bedrock interface have been clearly observed through the Greenland ice sheet. It would also provide a gross estimate of the amount of dust in the icy region. Models for the response of the nucleus and cometary plasma to electromagnetic sounding are developed and used to derive experimental parameters. A point system design was completed. Preliminary engineering study results indicate that the sounder is well within the bounds of current space technology.

TRI Preliminary Dataset

EPA Pesticide Factsheets

The TRI preliminary dataset includes the most current TRI data available and reflects toxic chemical releases and pollution prevention activities that occurred at TRI facilities during the each calendar year.

A Preliminary Study of V/STOL Transport Aircraft and Bibliography of NASA Research in the VTOL-STOL Field

NASA Technical Reports Server (NTRS)

1961-01-01

This group of papers was prepared by the staff of the Langley Research Center to assist in planning for future commercial air-transport facilities in the New York metropolitan area. Areas of particular interest were predictions regarding the types of V/STOL aircraft that are likely to be developed for various commercial transport applications, estimates of the performance and probable operating procedures for such aircraft, and the approximate dates these aircraft could be available for use. Although the NASA has made no comprehensive studies of this type, the extensive research program in the VTOL-STOL field during the last 10 years appeared to provide a source for some of the desired information . The five papers included herein were therefore prepared to summarize pertinent available material in a form suitable for the intended use. In several instances, new studies and analysis were required to provide the necessary information, but because of a time deadline, many of the significant points received only a cursory examination. For example, much of the quantitative data used in the papers for making generalized comparisons was obtained by approximate methods and is not considered appropriate for use in applications where precise estimates are required. It should be recognized, then, that the treatment of the V/STOL transport provided by this group of papers is necessarily of a preliminary nature.

Improved phase arrival estimate and location for local earthquakes in South Korea

NASA Astrophysics Data System (ADS)

Morton, E. A.; Rowe, C. A.; Begnaud, M. L.

2012-12-01

The Korean Institute of Geoscience and Mineral Resources (KIGAM) and the Korean Meteorological Agency (KMA) regularly report local (distance < ~1200 km) seismicity recorded with their networks; we obtain preliminary event location estimates as well as waveform data, but no phase arrivals are reported, so the data are not immediately useful for earthquake location. Our goal is to identify seismic events that are sufficiently well-located to provide accurate seismic travel-time information for events within the KIGAM and KMA networks, and also recorded by some regional stations. Toward that end, we are using a combination of manual phase identification and arrival-time picking, with waveform cross-correlation, to cluster events that have occurred in close proximity to one another, which allows for improved phase identification by comparing the highly correlating waveforms. We cross-correlate the known events with one another on 5 seismic stations and cluster events that correlate above a correlation coefficient threshold of 0.7, which reveals few clusters containing few events each. The small number of repeating events suggests that the online catalogs have had mining and quarry blasts removed before publication, as these can contribute significantly to repeating seismic sources in relatively aseismic regions such as South Korea. The dispersed source locations in our catalog, however, are ideal for seismic velocity modeling by providing superior sampling through the dense seismic station arrangement, which produces favorable event-to-station ray path coverage. Following careful manual phase picking on 104 events chosen to provide adequate ray coverage, we re-locate the events to obtain improved source coordinates. The re-located events are used with Thurber's Simul2000 pseudo-bending local tomography code to estimate the crustal structure on the Korean Peninsula, which is an important contribution to ongoing calibration for events of interest in the region.

32 CFR 1901.11 - Preliminary information.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Preliminary information. 1901.11 Section 1901.11 National Defense Other Regulations Relating to National Defense CENTRAL INTELLIGENCE AGENCY PUBLIC RIGHTS UNDER THE PRIVACY ACT OF 1974 Filing of Privacy Act Requests § 1901.11 Preliminary information. Members...

32 CFR 1901.11 - Preliminary information.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Preliminary information. 1901.11 Section 1901.11 National Defense Other Regulations Relating to National Defense CENTRAL INTELLIGENCE AGENCY PUBLIC RIGHTS UNDER THE PRIVACY ACT OF 1974 Filing of Privacy Act Requests § 1901.11 Preliminary information. Members...

Blind estimation of reverberation time

NASA Astrophysics Data System (ADS)

Ratnam, Rama; Jones, Douglas L.; Wheeler, Bruce C.; O'Brien, William D.; Lansing, Charissa R.; Feng, Albert S.

2003-11-01

The reverberation time (RT) is an important parameter for characterizing the quality of an auditory space. Sounds in reverberant environments are subject to coloration. This affects speech intelligibility and sound localization. Many state-of-the-art audio signal processing algorithms, for example in hearing-aids and telephony, are expected to have the ability to characterize the listening environment, and turn on an appropriate processing strategy accordingly. Thus, a method for characterization of room RT based on passively received microphone signals represents an important enabling technology. Current RT estimators, such as Schroeder's method, depend on a controlled sound source, and thus cannot produce an online, blind RT estimate. Here, a method for estimating RT without prior knowledge of sound sources or room geometry is presented. The diffusive tail of reverberation was modeled as an exponentially damped Gaussian white noise process. The time-constant of the decay, which provided a measure of the RT, was estimated using a maximum-likelihood procedure. The estimates were obtained continuously, and an order-statistics filter was used to extract the most likely RT from the accumulated estimates. The procedure was illustrated for connected speech. Results obtained for simulated and real room data are in good agreement with the real RT values.

Estimation of global soil respiration by accounting for land-use changes derived from remote sensing data.

PubMed

Adachi, Minaco; Ito, Akihiko; Yonemura, Seiichiro; Takeuchi, Wataru

2017-09-15

Soil respiration is one of the largest carbon fluxes from terrestrial ecosystems. Estimating global soil respiration is difficult because of its high spatiotemporal variability and sensitivity to land-use change. Satellite monitoring provides useful data for estimating the global carbon budget, but few studies have estimated global soil respiration using satellite data. We provide preliminary insights into the estimation of global soil respiration in 2001 and 2009 using empirically derived soil temperature equations for 17 ecosystems obtained by field studies, as well as MODIS climate data and land-use maps at a 4-km resolution. The daytime surface temperature from winter to early summer based on the MODIS data tended to be higher than the field-observed soil temperatures in subarctic and temperate ecosystems. The estimated global soil respiration was 94.8 and 93.8 Pg C yr -1 in 2001 and 2009, respectively. However, the MODIS land-use maps had insufficient spatial resolution to evaluate the effect of land-use change on soil respiration. The spatial variation of soil respiration (Q 10 ) values was higher but its spatial variation was lower in high-latitude areas than in other areas. However, Q 10 in tropical areas was more variable and was not accurately estimated (the values were >7.5 or <1.0) because of the low seasonal variation in soil respiration in tropical ecosystems. To solve these problems, it will be necessary to validate our results using a combination of remote sensing data at higher spatial resolution and field observations for many different ecosystems, and it will be necessary to account for the effects of more soil factors in the predictive equations. Copyright © 2017 Elsevier Ltd. All rights reserved.

A preliminary estimate of future communications traffic for the electric power system

NASA Technical Reports Server (NTRS)

Barnett, R. M.

1981-01-01

Diverse new generator technologies using renewable energy, and to improve operational efficiency throughout the existing electric power systems are presented. A description of a model utility and the information transfer requirements imposed by incorporation of dispersed storage and generation technologies and implementation of more extensive energy management are estimated. An example of possible traffic for an assumed system, and an approach that can be applied to other systems, control configurations, or dispersed storage and generation penetrations is provided.

Estimating surface hardening profile of blank for obtaining high drawing ratio in deep drawing process using FE analysis

NASA Astrophysics Data System (ADS)

Tan, C. J.; Aslian, A.; Honarvar, B.; Puborlaksono, J.; Yau, Y. H.; Chong, W. T.

2015-12-01

We constructed an FE axisymmetric model to simulate the effect of partially hardened blanks on increasing the limiting drawing ratio (LDR) of cylindrical cups. We partitioned an arc-shaped hard layer into the cross section of a DP590 blank. We assumed the mechanical property of the layer is equivalent to either DP980 or DP780. We verified the accuracy of the model by comparing the calculated LDR for DP590 with the one reported in the literature. The LDR for the partially hardened blank increased from 2.11 to 2.50 with a 1 mm depth of DP980 ring-shaped hard layer on the top surface of the blank. The position of the layer changed with drawing ratios. We proposed equations for estimating the inner and outer diameters of the layer, and tested its accuracy in the simulation. Although the outer diameters fitted in well with the estimated line, the inner diameters are slightly less than the estimated ones.

20 CFR 404.810 - How to obtain a statement of earnings and a benefit estimate statement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... records at the time of the request. If you have a social security number and have wages or net earnings... prescribed form, giving us your name, social security number, date of birth, and sex. You, your authorized... benefit estimate statement. 404.810 Section 404.810 Employees' Benefits SOCIAL SECURITY ADMINISTRATION...

Monte Carlo Estimation of Absorbed Dose Distributions Obtained from Heterogeneous 106Ru Eye Plaques.

PubMed

Zaragoza, Francisco J; Eichmann, Marion; Flühs, Dirk; Sauerwein, Wolfgang; Brualla, Lorenzo

2017-09-01

The distribution of the emitter substance in 106 Ru eye plaques is usually assumed to be homogeneous for treatment planning purposes. However, this distribution is never homogeneous, and it widely differs from plaque to plaque due to manufacturing factors. By Monte Carlo simulation of radiation transport, we study the absorbed dose distribution obtained from the specific CCA1364 and CCB1256 106 Ru plaques, whose actual emitter distributions were measured. The idealized, homogeneous CCA and CCB plaques are also simulated. The largest discrepancy in depth dose distribution observed between the heterogeneous and the homogeneous plaques was 7.9 and 23.7% for the CCA and CCB plaques, respectively. In terms of isodose lines, the line referring to 100% of the reference dose penetrates 0.2 and 1.8 mm deeper in the case of heterogeneous CCA and CCB plaques, respectively, with respect to the homogeneous counterpart. The observed differences in absorbed dose distributions obtained from heterogeneous and homogeneous plaques are clinically irrelevant if the plaques are used with a lateral safety margin of at least 2 mm. However, these differences may be relevant if the plaques are used in eccentric positioning.

32 CFR 1800.11 - Preliminary information.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Preliminary information. 1800.11 Section 1800.11... ACCESS TO NACIC RECORDS UNDER THE FREEDOM OF INFORMATION ACT (FOIA) Filing of FOIA Requests § 1800.11 Preliminary information. Members of the public shall address all communications to the NACIC Coordinator as...

Preliminary Drill Sites

DOE Data Explorer

Lane, Michael

2013-06-28

Preliminary locations for intermediate depth temperature gradient holes and/or resource confirmation wells based on compilation of geological, geophysical and geochemical data prior to carrying out the DOE-funded reflection seismic survey.

Analytical Approach for Estimating Preliminary Mass of ARES I Crew Launch Vehicle Upper Stage Structural Components

NASA Technical Reports Server (NTRS)

Aggarwal, Pravin

2007-01-01

electrical power functions to other Elements of the CLV, is included as secondary structure. The MSFC has an overall responsibility for the integrated US element as well as structural design an thermal control of the fuel tanks, intertank, interstage, avionics, main propulsion system, Reaction Control System (RCS) for both the Upper Stage and the First Stage. MSFC's Spacecraft and Vehicle Department, Structural and Analysis Design Division is developing a set of predicted mass of these elements. This paper details the methodology, criterion and tools used for the preliminary mass predictions of the upper stage structural assembly components. In general, weight of the cylindrical barrel sections are estimated using the commercial code Hypersizer, whereas, weight of the domes are developed using classical solutions. HyperSizer is software that performs automated structural analysis and sizing optimization based on aerospace methods for strength, stability, and stiffness. Analysis methods range from closed form, traditional hand calculations repeated every day in industry to more advanced panel buckling algorithms. Margin-of-safety reporting for every potential failure provides the engineer with a powerful insight into the structural problem. Optimization capabilities include finding minimum weight panel or beam concepts, material selections, cross sectional dimensions, thicknesses, and lay-ups from a library of 40 different stiffened and sandwich designs and a database of composite, metallic, honeycomb, and foam materials. Multiple different concepts (orthogrid, isogrid, and skin stiffener) were run for multiple loading combinations of ascent design load with and with out tank pressure as well as proof pressure condition. Subsequently, selected optimized concept obtained from Hypersizer runs was translated into a computer aid design (CAD) model to account for the wall thickness tolerance, weld land etc for developing the most probable weight of the components. The flow diram

Preliminary design of a redundant strapped down inertial navigation unit using two-degree-of-freedom tuned-gimbal gyroscopes

NASA Technical Reports Server (NTRS)

1976-01-01

This redundant strapdown INS preliminary design study demonstrates the practicality of a skewed sensor system configuration by means of: (1) devising a practical system mechanization utilizing proven strapdown instruments, (2) thoroughly analyzing the skewed sensor redundancy management concept to determine optimum geometry, data processing requirements, and realistic reliability estimates, and (3) implementing the redundant computers into a low-cost, maintainable configuration.

Estimating Primary Production of Picophytoplankton Using the Carbon-Based Ocean Productivity Model: A Preliminary Study

PubMed Central

Liang, Yantao; Zhang, Yongyu; Wang, Nannan; Luo, Tingwei; Zhang, Yao; Rivkin, Richard B.

2017-01-01

Picophytoplankton are acknowledged to contribute significantly to primary production (PP) in the ocean while now the method to measure PP of picophytoplankton (PPPico) at large scales is not yet well established. Although the traditional 14C method and new technologies based on the use of stable isotopes (e.g., 13C) can be employed to accurately measure in situ PPPico, the time-consuming and labor-intensive shortage of these methods constrain their application in a survey on large spatiotemporal scales. To overcome this shortage, a modified carbon-based ocean productivity model (CbPM) is proposed for estimating the PPPico whose principle is based on the group-specific abundance, cellular carbon conversion factor (CCF), and temperature-derived growth rate of picophytoplankton. Comparative analysis showed that the estimated PPPico using CbPM method is significantly and positively related (r2 = 0.53, P < 0.001, n = 171) to the measured 14C uptake. This significant relationship suggests that CbPM has the potential to estimate the PPPico over large spatial and temporal scales. Currently this model application may be limited by the use of invariant cellular CCF and the relatively small data sets to validate the model which may introduce some uncertainties and biases. Model performance will be improved by the use of variable conversion factors and the larger data sets representing diverse growth conditions. Finally, we apply the CbPM-based model on the collected data during four cruises in the Bohai Sea in 2005. Model-estimated PPPico ranged from 0.1 to 11.9, 29.9 to 432.8, 5.5 to 214.9, and 2.4 to 65.8 mg C m-2 d-1 during March, June, September, and December, respectively. This study shed light on the estimation of global PPPico using carbon-based production model. PMID:29051755

37 CFR 1.115 - Preliminary amendments.

Code of Federal Regulations, 2012 CFR

2012-07-01

... amendment unduly interferes with the preparation of a first Office action in an application. Factors that... first Office action as of the date of receipt (§ 1.6) of the preliminary amendment by the Office; and... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Preliminary amendments. 1.115...

37 CFR 1.115 - Preliminary amendments.

Code of Federal Regulations, 2010 CFR

2010-07-01

... amendment unduly interferes with the preparation of a first Office action in an application. Factors that... first Office action as of the date of receipt (§ 1.6) of the preliminary amendment by the Office; and... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Preliminary amendments. 1.115...

37 CFR 1.115 - Preliminary amendments.

Code of Federal Regulations, 2013 CFR

2013-07-01

... amendment unduly interferes with the preparation of a first Office action in an application. Factors that... first Office action as of the date of receipt (§ 1.6) of the preliminary amendment by the Office; and... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Preliminary amendments. 1.115...

32 CFR 1801.11 - Preliminary information.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Preliminary information. 1801.11 Section 1801.11... RIGHTS UNDER THE PRIVACY ACT OF 1974 Filing Of Privacy Act Requests § 1801.11 Preliminary information... outstanding fees for information services at this or other federal agencies will not be accepted and action on...

Estimating the Effective Permittivity for Reconstructing Accurate Microwave-Radar Images.

PubMed

Lavoie, Benjamin R; Okoniewski, Michal; Fear, Elise C

2016-01-01

We present preliminary results from a method for estimating the optimal effective permittivity for reconstructing microwave-radar images. Using knowledge of how microwave-radar images are formed, we identify characteristics that are typical of good images, and define a fitness function to measure the relative image quality. We build a polynomial interpolant of the fitness function in order to identify the most likely permittivity values of the tissue. To make the estimation process more efficient, the polynomial interpolant is constructed using a locally and dimensionally adaptive sampling method that is a novel combination of stochastic collocation and polynomial chaos. Examples, using a series of simulated, experimental and patient data collected using the Tissue Sensing Adaptive Radar system, which is under development at the University of Calgary, are presented. These examples show how, using our method, accurate images can be reconstructed starting with only a broad estimate of the permittivity range.

Multiscale estimation of excess mass from gravity data

NASA Astrophysics Data System (ADS)

Castaldo, Raffaele; Fedi, Maurizio; Florio, Giovanni

2014-06-01

We describe a multiscale method to estimate the excess mass of gravity anomaly sources, based on the theory of source moments. Using a multipole expansion of the potential field and considering only the data along the vertical direction, a system of linear equations is obtained. The choice of inverting data along a vertical profile can help us to reduce the interference effects due to nearby anomalies and will allow a local estimate of the source parameters. A criterion is established allowing the selection of the optimal highest altitude of the vertical profile data and truncation order of the series expansion. The inversion provides an estimate of the total anomalous mass and of the depth to the centre of mass. The method has several advantages with respect to classical methods, such as the Gauss' method: (i) we need just a 1-D inversion to obtain our estimates, being the inverted data sampled along a single vertical profile; (ii) the resolution may be straightforward enhanced by using vertical derivatives; (iii) the centre of mass is also estimated, besides the excess mass; (iv) the method is very robust versus noise; (v) the profile may be chosen in such a way to minimize the effects from interfering anomalies or from side effects due to the a limited area extension. The multiscale estimation of excess mass method can be successfully used in various fields of application. Here, we analyse the gravity anomaly generated by a sulphide body in the Skelleftea ore district, North Sweden, obtaining source mass and volume estimates in agreement with the known information. We show also that these estimates are substantially improved with respect to those obtained with the classical approach.

The Best Estimated Trajectory Analysis for Pad Abort One

NASA Technical Reports Server (NTRS)

Kutty, Prasad; Noonan, Meghan; Karlgaard, Christopher; Beck, Roger

2011-01-01

I. Best Estimated Trajectory (BET) objective: a) Produce reconstructed trajectory of the PA-1 flight to understand vehicle dynamics and aid other post flight analyses. b) Leverage all measurement sources taken of vehicle during flight to produce the most accurate estimate of vehicle trajectory. c) Generate trajectory reconstructions of the Crew Module (CM), Launch Abort System (LAS), and Forward Bay Cover (FBC). II. BET analysis was started immediately following the PA-1 mission and was completed in September, 2010 a) Quick look version of BET released 5/25/2010: initial repackaging of SIGI data. b) Preliminary version of BET released 7/6/2010: first blended solution using available sources of external measurements. c) Final version of BET released 9/1/2010: final blended solution using all available sources of data.

The Survey of Fires in Buildings. Third Report: The Use of Information Obtained From Fire Surveys

NASA Technical Reports Server (NTRS)

Silcock, A.

1973-01-01

The previous two reports in this series gave details of the general. scope of the pilot exercise and methods by which it was carried out. In addition the nature of the information obtained was illustrated by preliminary analyses of the house and industrial fires surveyed. Some brief comments on the use of the information were made. This report indicates a method of assessing the nation wide effects of applying conclusions drawn from the results of limited numbers of surveys and considers the use of the information for specific purposes.

Attention in western Nevada: Preliminary results from earthquake and explosion sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hough, S.E.; Anderson, J.G.; Patton, H.J.

1989-02-01

We present preliminary results from a study of the attenuation of regional seismic waves at frequencies between 1 and 15 Hz and distances up to 250 km in Western Nevada. Following the methods of Anderson and Hough (1984) and Hough et al. (1988), we parameterize the asymptote of the high frequency acceleration spectrum by the two-parameter model. We relate the model parameters to a two-layer model for Q/sub i/ and Q/sub d/, the freuqency-independent and the frequency dependent components of the quality factor. We compare our results to previously published Q studies in the Basin and Range and find thatmore » our estimate of total Q, Q/sub t/, in the shallow crust is consistent with shear wave Q at close distances with previous estimates of coda Q (Singh and Hermann, 1983) and LgQ (Chavez and Priestley, 1986), suggesting that both coda Q and LgQ are insensitive to near-surface contributions to attenuation.« less

Investigation of Properties of Nanocomposite Polyimide Samples Obtained by Fused Deposition Modeling

NASA Astrophysics Data System (ADS)

Polyakov, I. V.; Vaganov, G. V.; Yudin, V. E.; Ivan'kova, E. M.; Popova, E. N.; Elokhovskii, V. Yu.

2018-03-01

Nanomodified polyimide samples were obtained by fused deposition modeling (FDM) using an experimental setup for 3D printing of highly heat-resistant plastics. The mechanical properties and structure of these samples were studied by viscosimetry, differential scanning calorimetry, and scanning electron microscopy. A comparative estimation of the mechanical properties of laboratory samples obtained from a nanocomposite based on heat-resistant polyetherimide by FDM and injection molding is presented.

The use of the multiwavelet transform for the estimation of surface wave group and phase velocities and their associated uncertainties

NASA Astrophysics Data System (ADS)

Poppeliers, C.; Preston, L. A.

2017-12-01

Measurements of seismic surface wave dispersion can be used to infer the structure of the Earth's subsurface. Typically, to identify group- and phase-velocity, a series of narrow-band filters are applied to surface wave seismograms. Frequency dependent arrival times of surface waves can then be identified from the resulting suite of narrow band seismograms. The frequency-dependent velocity estimates are then inverted for subsurface velocity structure. However, this technique has no method to estimate the uncertainty of the measured surface wave velocities, and subsequently there is no estimate of uncertainty on, for example, tomographic results. For the work here, we explore using the multiwavelet transform (MWT) as an alternate method to estimate surface wave speeds. The MWT decomposes a signal similarly to the conventional filter bank technique, but with two primary advantages: 1) the time-frequency localization is optimized in regard to the time-frequency tradeoff, and 2) we can use the MWT to estimate the uncertainty of the resulting surface wave group- and phase-velocities. The uncertainties of the surface wave speed measurements can then be propagated into tomographic inversions to provide uncertainties of resolved Earth structure. As proof-of-concept, we apply our technique to four seismic ambient noise correlograms that were collected from the University of Nevada Reno seismic network near the Nevada National Security Site. We invert the estimated group- and phase-velocities, as well the uncertainties, for 1-D Earth structure for each station pair. These preliminary results generally agree with 1-D velocities that are obtained from inverting dispersion curves estimated from a conventional Gaussian filter bank.

Space Shuttle propulsion parameter estimation using optimal estimation techniques, volume 1

NASA Technical Reports Server (NTRS)

1983-01-01

The mathematical developments and their computer program implementation for the Space Shuttle propulsion parameter estimation project are summarized. The estimation approach chosen is the extended Kalman filtering with a modified Bryson-Frazier smoother. Its use here is motivated by the objective of obtaining better estimates than those available from filtering and to eliminate the lag associated with filtering. The estimation technique uses as the dynamical process the six degree equations-of-motion resulting in twelve state vector elements. In addition to these are mass and solid propellant burn depth as the ""system'' state elements. The ""parameter'' state elements can include aerodynamic coefficient, inertia, center-of-gravity, atmospheric wind, etc. deviations from referenced values. Propulsion parameter state elements have been included not as options just discussed but as the main parameter states to be estimated. The mathematical developments were completed for all these parameters. Since the systems dynamics and measurement processes are non-linear functions of the states, the mathematical developments are taken up almost entirely by the linearization of these equations as required by the estimation algorithms.

Post Detection Target State Estimation Using Heuristic Information Processing - A Preliminary Investigation

DTIC Science & Technology

1977-09-01

Interpolation algorithm allows this to be done when the transition boundaries are defined close together and parallel to one another. In this case the...in the variable kernel esti- -mates.) In [2] a goodness-of-fit criterion for a set of sam- One question of great interest to us in this study pies...an estimate /(x) is For the unimodal case the ab.olute minimum okV .based on the variables ocurs at k .= 100, ce 5. At this point we have j Mean

Energy and maximum norm estimates for nonlinear conservation laws

NASA Technical Reports Server (NTRS)

Olsson, Pelle; Oliger, Joseph

1994-01-01

We have devised a technique that makes it possible to obtain energy estimates for initial-boundary value problems for nonlinear conservation laws. The two major tools to achieve the energy estimates are a certain splitting of the flux vector derivative f(u)(sub x), and a structural hypothesis, referred to as a cone condition, on the flux vector f(u). These hypotheses are fulfilled for many equations that occur in practice, such as the Euler equations of gas dynamics. It should be noted that the energy estimates are obtained without any assumptions on the gradient of the solution u. The results extend to weak solutions that are obtained as point wise limits of vanishing viscosity solutions. As a byproduct we obtain explicit expressions for the entropy function and the entropy flux of symmetrizable systems of conservation laws. Under certain circumstances the proposed technique can be applied repeatedly so as to yield estimates in the maximum norm.

Preliminary investigation of Zagros thrust-fold-belt deformation using SAR interferometry

NASA Technical Reports Server (NTRS)

Nilforoushan, Faramarz; Talbot, Christopher J.; Fielding, Eric J.

2005-01-01

Most of the Zagros deformation resulting from the convergence of Arabia and Eurasia takes place in the Southeast Zagros. To apply the SAR interferometry geodetic technique, a few ERS 1 & 2 satellite images were used to map this continuing deformation proven by GPS. Interferograms over 7 years show surprisingly high coherence. The unwrapped phases display a high correlation with topography reflecting atmospheric noise in addition to the desired tectonic signal. We estimate two simple linear trends and remove them from interferograms. The preliminary results show local uplift rates with a likely minimum of 1-2 mm/yr. These early crude results will be tested by more data in project No. 3174.

Brayton cycle heat exchanger and duct assembly (HXDA, preliminary design and technology tests

NASA Technical Reports Server (NTRS)

Coombs, M. G.; Morse, C. J.; Graves, R. F.; Gibson, J. C.

1972-01-01

A preliminary design of the heat exchanger and duct assembly (HXDA) for a 60 kwe, closed loop, Brayton cycle space power system is presented. This system is weight optimized within the constraints imposed by the defined structural and operational requirements. Also presented are the results of several small scale tests, directed to obtaining specific design data and/or the resolution of a design approach for long life Brayton cycle heat exchanger systems.

Modeling the complete Otto cycle: Preliminary version. [computer programming

NASA Technical Reports Server (NTRS)

Zeleznik, F. J.; Mcbride, B. J.

1977-01-01

A description is given of the equations and the computer program being developed to model the complete Otto cycle. The program incorporates such important features as: (1) heat transfer, (2) finite combustion rates, (3) complete chemical kinetics in the burned gas, (4) exhaust gas recirculation, and (5) manifold vacuum or supercharging. Changes in thermodynamic, kinetic and transport data as well as model parameters can be made without reprogramming. Preliminary calculations indicate that: (1) chemistry and heat transfer significantly affect composition and performance, (2) there seems to be a strong interaction among model parameters, and (3) a number of cycles must be calculated in order to obtain steady-state conditions.

A preliminary design of the collinear dielectric wakefield accelerator

NASA Astrophysics Data System (ADS)

Zholents, A.; Gai, W.; Doran, S.; Lindberg, R.; Power, J. G.; Strelnikov, N.; Sun, Y.; Trakhtenberg, E.; Vasserman, I.; Jing, C.; Kanareykin, A.; Li, Y.; Gao, Q.; Shchegolkov, D. Y.; Simakov, E. I.

2016-09-01

A preliminary design of the multi-meter long collinear dielectric wakefield accelerator that achieves a highly efficient transfer of the drive bunch energy to the wakefields and to the witness bunch is considered. It is made from 0.5 m long accelerator modules containing a vacuum chamber with dielectric-lined walls, a quadrupole wiggler, an rf coupler, and BPM assembly. The single bunch breakup instability is a major limiting factor for accelerator efficiency, and the BNS damping is applied to obtain the stable multi-meter long propagation of a drive bunch. Numerical simulations using a 6D particle tracking computer code are performed and tolerances to various errors are defined.

Temporal variability patterns in solar radiation estimations

NASA Astrophysics Data System (ADS)

Vindel, José M.; Navarro, Ana A.; Valenzuela, Rita X.; Zarzalejo, Luis F.

2016-06-01

In this work, solar radiation estimations obtained from a satellite and a numerical weather prediction model in mainland Spain have been compared. Similar comparisons have been formerly carried out, but in this case, the methodology used is different: the temporal variability of both sources of estimation has been compared with the annual evolution of the radiation associated to the different study climate zones. The methodology is based on obtaining behavior patterns, using a Principal Component Analysis, following the annual evolution of solar radiation estimations. Indeed, the adjustment degree to these patterns in each point (assessed from maps of correlation) may be associated with the annual radiation variation (assessed from the interquartile range), which is associated, in turn, to different climate zones. In addition, the goodness of each estimation source has been assessed comparing it with data obtained from the radiation measurements in ground by pyranometers. For the study, radiation data from Satellite Application Facilities and data corresponding to the reanalysis carried out by the European Centre for Medium-Range Weather Forecasts have been used.

Robot acting on moving bodies (RAMBO): Preliminary results

NASA Technical Reports Server (NTRS)

Davis, Larry S.; Dementhon, Daniel; Bestul, Thor; Ziavras, Sotirios; Srinivasan, H. V.; Siddalingaiah, Madju; Harwood, David

1989-01-01

A robot system called RAMBO is being developed. It is equipped with a camera, which, given a sequence of simple tasks, can perform these tasks on a moving object. RAMBO is given a complete geometric model of the object. A low level vision module extracts and groups characteristic features in images of the object. The positions of the object are determined in a sequence of images, and a motion estimate of the object is obtained. This motion estimate is used to plan trajectories of the robot tool to relative locations nearby the object sufficient for achieving the tasks. More specifically, low level vision uses parallel algorithms for image enchancement by symmetric nearest neighbor filtering, edge detection by local gradient operators, and corner extraction by sector filtering. The object pose estimation is a Hough transform method accumulating position hypotheses obtained by matching triples of image features (corners) to triples of model features. To maximize computing speed, the estimate of the position in space of a triple of features is obtained by decomposing its perspective view into a product of rotations and a scaled orthographic projection. This allows the use of 2-D lookup tables at each stage of the decomposition. The position hypotheses for each possible match of model feature triples and image feature triples are calculated in parallel. Trajectory planning combines heuristic and dynamic programming techniques. Then trajectories are created using parametric cubic splines between initial and goal trajectories. All the parallel algorithms run on a Connection Machine CM-2 with 16K processors.

Covariance Matrix Estimation for Massive MIMO

NASA Astrophysics Data System (ADS)

Upadhya, Karthik; Vorobyov, Sergiy A.

2018-04-01

We propose a novel pilot structure for covariance matrix estimation in massive multiple-input multiple-output (MIMO) systems in which each user transmits two pilot sequences, with the second pilot sequence multiplied by a random phase-shift. The covariance matrix of a particular user is obtained by computing the sample cross-correlation of the channel estimates obtained from the two pilot sequences. This approach relaxes the requirement that all the users transmit their uplink pilots over the same set of symbols. We derive expressions for the achievable rate and the mean-squared error of the covariance matrix estimate when the proposed method is used with staggered pilots. The performance of the proposed method is compared with existing methods through simulations.

Analysis of low gravity tolerance of model experiments for space station: Preliminary results for directional solidification

NASA Technical Reports Server (NTRS)

Alexander, J. Iwan D.; Ouazzani, Jalil

1988-01-01

It has become clear from measurements of the acceleration environment in the Spacelab that the residual gravity levels on board a spacecraft in low Earth orbit can be significant and should be of concern to experimenters who wish to take advantage of the low gravity conditions on future Spacelab missions and on board the Space Station. The basic goals are to better understand the low gravity tolerance of three classes of materials science experiments: crystal growth from a melt, a vapor, and a solution. The results of the research will provide guidance toward the determination of the sensitivity of the low gravity environment, the design of the laboratory facilites, and the timelining of materials science experiments. To data, analyses of the effects of microgravity environment were, with a few exceptions, restricted to order of magnitude estimates. Preliminary results obtained from numerical models of the effects of residual steady and time dependent acceleration are reported on: heat, mass, and momentum transport during the growth of a dilute alloy by the Bridgman-Stockbarger technique, and the response of a simple fluid physics experiment involving buoyant convection in a square cavity.

Preliminary Results of Field Emission Cathode Tests

NASA Technical Reports Server (NTRS)

Sovey, James S.; Kovaleski, Scott D.

2001-01-01

Preliminary screening tests of field emission cathodes such as chemical vapor deposited (CVD) diamond, textured pyrolytic graphite, and textured copper were conducted at background pressures typical of electric thruster test facilities to assess cathode performance and stability. Very low power electric thrusters which provide tens to hundreds micronewtons of thrust may need field emission neutralizers that have a capability of tens to hundreds of microamperes. From current voltage characteristics, it was found that the CVD diamond and textured metals cathodes clearly satisfied the Fowler-Nordheim emission relation. The CVD diamond and a textured copper cathode had average current densities of 270 and 380 mA/sq cm, respectively, at the beginning-of-life. After a few hours of operation the cathode emission currents degraded by 40 to 75% at background pressures in the 10(exp -5) Pa to 10(exp -4) Pa range. The textured pyrolytic graphite had a modest current density at beginning-of-life of 84 mA/sq cm, but this cathode was the most stable of all. Extended testing of the most promising cathodes is warranted to determine if current degradation is a burn-in effect or whether it is a long-term degradation process. Preliminary experiments with ferroelectric emission cathodes, which are ceramics with spontaneous electric polarization, were conducted. Peak current densities of 30 to 120 mA/sq cm were obtained for pulse durations of about 500 ns in the 10(exp -4) Pa pressure range.

Preliminary estimates of the quantities of rare-earth elements contained in selected products and in imports of semimanufactured products to the United States, 2010

USGS Publications Warehouse

Bleiwas, Donald I.; Gambogi, Joseph

2013-01-01

Rare-earth elements (REEs) are contained in a wide range of products of economic and strategic importance to the Nation. The REEs may or may not represent a significant component of that product by mass, value, or volume; however, in many cases, the embedded REEs are critical for the device’s function. Domestic sources of primary supply and the manufacturing facilities to produce products are inadequate to meet U.S. requirements; therefore, a significant percentage of the supply of REEs and the products that contain them are imported to the United States. In 2011, mines in China produced roughly 97 percent of the world’s supply of REEs, and the country’s production of these elements will likely dominate global supply until at least 2020. Preliminary estimates of the types and amount of rare-earth elements, reported as oxides, in semimanufactured form and the amounts used for electric vehicle batteries, catalytic converters, computers, and other applications were developed to provide a perspective on the Nation’s use of these elements. The amount of rare-earth metals recovered from recycling, remanufacturing, and reuse is negligible when the tonnage of products that contain REEs deposited in landfills and retained in storage is considered. Under favorable market conditions, the recovery of REEs from obsolete products could potentially displace a portion of the supply from primary sources.

Novel angle estimation for bistatic MIMO radar using an improved MUSIC

NASA Astrophysics Data System (ADS)

Li, Jianfeng; Zhang, Xiaofei; Chen, Han

2014-09-01

In this article, we study the problem of angle estimation for bistatic multiple-input multiple-output (MIMO) radar and propose an improved multiple signal classification (MUSIC) algorithm for joint direction of departure (DOD) and direction of arrival (DOA) estimation. The proposed algorithm obtains initial estimations of angles obtained from the signal subspace and uses the local one-dimensional peak searches to achieve the joint estimations of DOD and DOA. The angle estimation performance of the proposed algorithm is better than that of estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm, and is almost the same as that of two-dimensional MUSIC. Furthermore, the proposed algorithm can be suitable for irregular array geometry, obtain automatically paired DOD and DOA estimations, and avoid two-dimensional peak searching. The simulation results verify the effectiveness and improvement of the algorithm.

Calculating weighted estimates of peak streamflow statistics

USGS Publications Warehouse

Cohn, Timothy A.; Berenbrock, Charles; Kiang, Julie E.; Mason, Jr., Robert R.

2012-01-01

According to the Federal guidelines for flood-frequency estimation, the uncertainty of peak streamflow statistics, such as the 1-percent annual exceedance probability (AEP) flow at a streamgage, can be reduced by combining the at-site estimate with the regional regression estimate to obtain a weighted estimate of the flow statistic. The procedure assumes the estimates are independent, which is reasonable in most practical situations. The purpose of this publication is to describe and make available a method for calculating a weighted estimate from the uncertainty or variance of the two independent estimates.

Probability Distribution Extraction from TEC Estimates based on Kernel Density Estimation

NASA Astrophysics Data System (ADS)

Demir, Uygar; Toker, Cenk; Çenet, Duygu

2016-07-01

Statistical analysis of the ionosphere, specifically the Total Electron Content (TEC), may reveal important information about its temporal and spatial characteristics. One of the core metrics that express the statistical properties of a stochastic process is its Probability Density Function (pdf). Furthermore, statistical parameters such as mean, variance and kurtosis, which can be derived from the pdf, may provide information about the spatial uniformity or clustering of the electron content. For example, the variance differentiates between a quiet ionosphere and a disturbed one, whereas kurtosis differentiates between a geomagnetic storm and an earthquake. Therefore, valuable information about the state of the ionosphere (and the natural phenomena that cause the disturbance) can be obtained by looking at the statistical parameters. In the literature, there are publications which try to fit the histogram of TEC estimates to some well-known pdf.s such as Gaussian, Exponential, etc. However, constraining a histogram to fit to a function with a fixed shape will increase estimation error, and all the information extracted from such pdf will continue to contain this error. In such techniques, it is highly likely to observe some artificial characteristics in the estimated pdf which is not present in the original data. In the present study, we use the Kernel Density Estimation (KDE) technique to estimate the pdf of the TEC. KDE is a non-parametric approach which does not impose a specific form on the TEC. As a result, better pdf estimates that almost perfectly fit to the observed TEC values can be obtained as compared to the techniques mentioned above. KDE is particularly good at representing the tail probabilities, and outliers. We also calculate the mean, variance and kurtosis of the measured TEC values. The technique is applied to the ionosphere over Turkey where the TEC values are estimated from the GNSS measurement from the TNPGN-Active (Turkish National Permanent

Credit cues and impression management: a preliminary attempt to explain the credit card effect.

PubMed

McCall, Michael; Trombetta, Jessica; Gipe, Aimee

2004-08-01

Prior research had suggested that individuals would estimate higher product values and even tip more in the presence of credit cues. In the absence of a clear theoretical interpretation of this credit card effect we propose that this tendency is an impression management strategy such that credit cue exposure influences perceptions of the self and focuses attention on individual wealth. Thus, in the presence of others, credit cues serve to enhance images of the self. Preliminary data in support of this alternative theoretical perspective are presented.

Estimation on the First Cycle of the Annual Forest Inventory System: Methods, Preliminary Results, and Observations

Treesearch

Mark H. Hansen; Gary J. Brand; Daniel G. Wendt; Ronald E. McRoberts

2001-01-01

The first year of annual FIA data collection in the North Central region was completed for 1999 in Indiana, Iowa, Minnesota, and Missouri. Estimates of timberland area, total growing-stock volume and growing-stock volume per acre are presented. These estimates are based on data from 1 year, collected at the base Federal inventory intensity, a lower intensity sample...

SURE Estimates for a Heteroscedastic Hierarchical Model

PubMed Central

Xie, Xianchao; Kou, S. C.; Brown, Lawrence D.

2014-01-01

Hierarchical models are extensively studied and widely used in statistics and many other scientific areas. They provide an effective tool for combining information from similar resources and achieving partial pooling of inference. Since the seminal work by James and Stein (1961) and Stein (1962), shrinkage estimation has become one major focus for hierarchical models. For the homoscedastic normal model, it is well known that shrinkage estimators, especially the James-Stein estimator, have good risk properties. The heteroscedastic model, though more appropriate for practical applications, is less well studied, and it is unclear what types of shrinkage estimators are superior in terms of the risk. We propose in this paper a class of shrinkage estimators based on Stein’s unbiased estimate of risk (SURE). We study asymptotic properties of various common estimators as the number of means to be estimated grows (p → ∞). We establish the asymptotic optimality property for the SURE estimators. We then extend our construction to create a class of semi-parametric shrinkage estimators and establish corresponding asymptotic optimality results. We emphasize that though the form of our SURE estimators is partially obtained through a normal model at the sampling level, their optimality properties do not heavily depend on such distributional assumptions. We apply the methods to two real data sets and obtain encouraging results. PMID:25301976

A novel SURE-based criterion for parametric PSF estimation.

PubMed

Xue, Feng; Blu, Thierry

2015-02-01

We propose an unbiased estimate of a filtered version of the mean squared error--the blur-SURE (Stein's unbiased risk estimate)--as a novel criterion for estimating an unknown point spread function (PSF) from the degraded image only. The PSF is obtained by minimizing this new objective functional over a family of Wiener processings. Based on this estimated blur kernel, we then perform nonblind deconvolution using our recently developed algorithm. The SURE-based framework is exemplified with a number of parametric PSF, involving a scaling factor that controls the blur size. A typical example of such parametrization is the Gaussian kernel. The experimental results demonstrate that minimizing the blur-SURE yields highly accurate estimates of the PSF parameters, which also result in a restoration quality that is very similar to the one obtained with the exact PSF, when plugged into our recent multi-Wiener SURE-LET deconvolution algorithm. The highly competitive results obtained outline the great potential of developing more powerful blind deconvolution algorithms based on SURE-like estimates.

Timing of paleoearthquakes on the northern Hayward Fault: preliminary evidence in El Cerrito, California

USGS Publications Warehouse

Lienkaemper, J.J.; Schwartz, D.P.; Kelson, K.I.; Lettis, W.R.; Simpson, Gary D.; Southon, J.R.; Wanket, J.A.; Williams, P.L.

1999-01-01

The Working Group on California Earthquake Probabilities estimated that the northern Hayward fault had the highest probability (0.28) of producing a M7 Bay Area earthquake in 30 years (WGCEP, 1990). This probability was based, in part, on the assumption that the last large earthquake occurred on this segment in 1836. However, a recent study of historical documents concludes that the 1836 earthquake did not occur on the northern Hayward fault, thereby extending the elapsed time to at least 220 yr ago, the beginning of the written record. The average recurrence interval for a M7 on the northern Hayward is unknown. WGCEP (1990) assumed an interval of 167 years. The 1996 Working Group on Northern California Earthquake Potential estimated ~210 yr, based on extrapolations from southern Hayward paleoseismological studies and a revised estimate of 1868 slip on the southern Hayward fault. To help constrain the timing of paleoearthquakes on the northern Hayward fault for the 1999 Bay Area probability update, we excavated two trenches that cross the fault and a sag pond on the Mira Vista golf course. As the site is on the second fairway, we were limited to less than ten days to document these trenches. Analysis was aided by rapid C-14 dating of more than 90 samples which gave near real-time results with the trenches still open. A combination of upward fault terminations, disrupted strata, and discordant angular relations indicates at least four, and possibly seven or more, surface faulting earthquakes occurred during a 1630-2130 yr interval. Hence, average recurrence time could be <270 yr, but is no more than 710 yr. The most recent earthquake (MRE) occurred after AD 1640. Preliminary analysis of calibrated dates supports the assumption that no large historical (post-1776) earthquakes have ruptured the surface here, but the youngest dates need more corroboration. Analyses of pollen for presence of non-native species help to constrain the time of the MRE. The earthquake

Preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model

USGS Publications Warehouse

Madenjian, Charles P.; Pothoven, Steven A.; Schneeberger, Philip J.; O'Connor, Daniel V.; Brandt, Stephen B.

2005-01-01

We conducted a preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model by applying the model to size-at-age data for lake whitefish from northern Lake Michigan. We then compared estimates of gross growth efficiency (GGE) from our bioenergetis model with previously published estimates of GGE for bloater (C. hoyi) in Lake Michigan and for lake whitefish in Quebec. According to our model, the GGE of Lake Michigan lake whitefish decreased from 0.075 to 0.02 as age increased from 2 to 5 years. In contrast, the GGE of lake whitefish in Quebec inland waters decreased from 0.12 to 0.05 for the same ages. When our swimming-speed submodel was replaced with a submodel that had been used for lake trout (Salvelinus namaycush) in Lake Michigan and an observed predator energy density for Lake Michigan lake whitefish was employed, our model predicted that the GGE of Lake Michigan lake whitefish decreased from 0.12 to 0.04 as age increased from 2 to 5 years.

A Preliminary Appraisal of the Needs for and Means of Obtaining the Necessary College Facilities at a Minimal Cost to the Taxpayer.

ERIC Educational Resources Information Center

Bortolazzo, Julio L.

San Joaquin Delta College (California), planning on an enrollment increase of more than 10% annually, has estimated its minimum facility needs for an enrollment of approximately 7500 students by 1972. The gross cost per square foot is expected to be $25.00 for general construction and $38.50 for special construction. For an estimated total of…

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1975-01-01

A general iterative procedure is given for determining the consistent maximum likelihood estimates of normal distributions. In addition, a local maximum of the log-likelihood function, Newtons's method, a method of scoring, and modifications of these procedures are discussed.

Magnetic Field Observations near Mercury: Preliminary Results from Mariner 10.

PubMed

Ness, N F; Behannon, K W; Lepping, R P; Whang, Y C; Schatten, K H

1974-07-12

Results are presented from a preliminary analysis of data obtained near Mercury on 29 March 1974 by the NASA-GSFC magnetic field experiment on Mariner 10. Rather unexpectedly, a very well-developed, detached bow shock wave, which develops as the super-Alfvénic solar wind interacts with the planet, has been observed. In addition, a magnetosphere-like region, with maximum field strength of 98 gammas at closest approach (704 kilometers altitude), has been observed, contained within boundaries similar to the terrestrial magnetopause. The obstacle deflecting the solar wind flow is global in size, but the origin of the enhanced magnetic field has not yet been uniquely established. The field may be intrinsic to the planet and distorted by interaction with the solar wind. It may also be associated with a complex induction process whereby the planetary interior-atmosphere-ionosphere interacts with the solar wind flow to generate the observed field by a dynamo action. The complete body of data favors the preliminary conclusion that Mercury has an intrinsic magnetic field. If this is correct, it represents a major scientific discovery in planetary magnetism and will have considerable impact on studies of the origin of the solar system.

A channel estimation scheme for MIMO-OFDM systems

NASA Astrophysics Data System (ADS)

He, Chunlong; Tian, Chu; Li, Xingquan; Zhang, Ce; Zhang, Shiqi; Liu, Chaowen

2017-08-01

In view of the contradiction of the time-domain least squares (LS) channel estimation performance and the practical realization complexity, a reduced complexity channel estimation method for multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) based on pilot is obtained. This approach can transform the complexity of MIMO-OFDM channel estimation problem into a simple single input single output-orthogonal frequency division multiplexing (SISO-OFDM) channel estimation problem and therefore there is no need for large matrix pseudo-inverse, which greatly reduces the complexity of algorithms. Simulation results show that the bit error rate (BER) performance of the obtained method with time orthogonal training sequences and linear minimum mean square error (LMMSE) criteria is better than that of time-domain LS estimator and nearly optimal performance.

Sexual functioning in military personnel: preliminary estimates and predictors.

PubMed

Wilcox, Sherrie L; Redmond, Sarah; Hassan, Anthony M

2014-10-01

Although the military is a young and vigorous force, service members and veterans may experience sexual functioning problems (SFPs) as a result of military service. Sexual functioning can be impaired by physical, psychological, and social factors and can impact quality of life (QOL) and happiness. This study aims to estimate rates and correlates of SFPs in male military personnel across demographic and psychosocial characteristics, to examine the QOL concomitants, and to evaluate barriers for treatment seeking. This exploratory cross-sectional study was conducted using data from a larger nationwide study conducted between October 2013 and November 2013. This sample consists of 367 male active duty service members and recent veterans (military personnel) age 40 or younger. Erectile dysfunction (ED) was determined using the five-item International Index of Erectile Function, sexual dysfunction (SD) was determined using the Arizona Sexual Experiences Scale, Male, and QOL was determined using the World Health Organization Quality of Life, Brief. SFPs were associated with various demographic, physical, and psychosocial risk factors. The rates of SD and ED were 8.45% and 33.24%, respectively, for male military personnel aged 21-40. Those who were 36-40, nonmarried, nonwhite, and of lower educational attainment reported the highest rates of SFPs. Male military personnel with poor physical and psychosocial health presented the greatest risk for ED and SD. SFPs were associated with reduced QOL and lower happiness, and barriers for treatment were generally related to social barriers. SFPs in young male military personnel are an important public health concern that can severely impact QOL and happiness. © 2014 International Society for Sexual Medicine.

Smarter Balanced Preliminary Performance Levels: Estimated MAP Scores Corresponding to the Preliminary Performance Levels of the Smarter Balanced Assessment Consortium (Smarter Balanced)

ERIC Educational Resources Information Center

Northwest Evaluation Association, 2015

2015-01-01

Recently, the Smarter Balanced Assessment Consortium (Smarter Balanced) released a document that established initial performance levels and the associated threshold scale scores for the Smarter Balanced assessment. The report included estimated percentages of students expected to perform at each of the four performance levels, reported by grade…

Rainfall assimilation in RAMS by means of the Kuo parameterisation inversion: method and preliminary results

NASA Astrophysics Data System (ADS)

Orlandi, A.; Ortolani, A.; Meneguzzo, F.; Levizzani, V.; Torricella, F.; Turk, F. J.

2004-03-01

In order to improve high-resolution forecasts, a specific method for assimilating rainfall rates into the Regional Atmospheric Modelling System model has been developed. It is based on the inversion of the Kuo convective parameterisation scheme. A nudging technique is applied to 'gently' increase with time the weight of the estimated precipitation in the assimilation process. A rough but manageable technique is explained to estimate the partition of convective precipitation from stratiform one, without requiring any ancillary measurement. The method is general purpose, but it is tuned for geostationary satellite rainfall estimation assimilation. Preliminary results are presented and discussed, both through totally simulated experiments and through experiments assimilating real satellite-based precipitation observations. For every case study, Rainfall data are computed with a rapid update satellite precipitation estimation algorithm based on IR and MW satellite observations. This research was carried out in the framework of the EURAINSAT project (an EC research project co-funded by the Energy, Environment and Sustainable Development Programme within the topic 'Development of generic Earth observation technologies', Contract number EVG1-2000-00030).

Evaluation of Bayesian Sequential Proportion Estimation Using Analyst Labels

NASA Technical Reports Server (NTRS)

Lennington, R. K.; Abotteen, K. M. (Principal Investigator)

1980-01-01

The author has identified the following significant results. A total of ten Large Area Crop Inventory Experiment Phase 3 blind sites and analyst-interpreter labels were used in a study to compare proportional estimates obtained by the Bayes sequential procedure with estimates obtained from simple random sampling and from Procedure 1. The analyst error rate using the Bayes technique was shown to be no greater than that for the simple random sampling. Also, the segment proportion estimates produced using this technique had smaller bias and mean squared errors than the estimates produced using either simple random sampling or Procedure 1.

Coastal Amplification Laws for the French Tsunami Warning Center: Numerical Modeling and Fast Estimate of Tsunami Wave Heights Along the French Riviera

NASA Astrophysics Data System (ADS)

Gailler, A.; Hébert, H.; Schindelé, F.; Reymond, D.

2017-11-01

Tsunami modeling tools in the French tsunami Warning Center operational context provide rapidly derived warning levels with a dimensionless variable at basin scale. A new forecast method based on coastal amplification laws has been tested to estimate the tsunami onshore height, with a focus on the French Riviera test-site (Nice area). This fast prediction tool provides a coastal tsunami height distribution, calculated from the numerical simulation of the deep ocean tsunami amplitude and using a transfer function derived from the Green's law. Due to a lack of tsunami observations in the western Mediterranean basin, coastal amplification parameters are here defined regarding high resolution nested grids simulations. The preliminary results for the Nice test site on the basis of nine historical and synthetic sources show a good agreement with the time-consuming high resolution modeling: the linear approximation is obtained within 1 min in general and provides estimates within a factor of two in amplitude, although the resonance effects in harbors and bays are not reproduced. In Nice harbor especially, variation in tsunami amplitude is something that cannot be really assessed because of the magnitude range and maximum energy azimuth of possible events to account for. However, this method is well suited for a fast first estimate of the coastal tsunami threat forecast.

Coastal Amplification Laws for the French Tsunami Warning Center: Numerical Modeling and Fast Estimate of Tsunami Wave Heights Along the French Riviera

NASA Astrophysics Data System (ADS)

Gailler, A.; Hébert, H.; Schindelé, F.; Reymond, D.

2018-04-01

Tsunami modeling tools in the French tsunami Warning Center operational context provide rapidly derived warning levels with a dimensionless variable at basin scale. A new forecast method based on coastal amplification laws has been tested to estimate the tsunami onshore height, with a focus on the French Riviera test-site (Nice area). This fast prediction tool provides a coastal tsunami height distribution, calculated from the numerical simulation of the deep ocean tsunami amplitude and using a transfer function derived from the Green's law. Due to a lack of tsunami observations in the western Mediterranean basin, coastal amplification parameters are here defined regarding high resolution nested grids simulations. The preliminary results for the Nice test site on the basis of nine historical and synthetic sources show a good agreement with the time-consuming high resolution modeling: the linear approximation is obtained within 1 min in general and provides estimates within a factor of two in amplitude, although the resonance effects in harbors and bays are not reproduced. In Nice harbor especially, variation in tsunami amplitude is something that cannot be really assessed because of the magnitude range and maximum energy azimuth of possible events to account for. However, this method is well suited for a fast first estimate of the coastal tsunami threat forecast.

A preliminary assessment of the deep-sea Decapoda collected during the KARUBENTHOS 2015 Expedition to Guadeloupe Island.

PubMed

Poupin, Joseph; Corbari, Laure

2016-11-13

A preliminary assessment of the deep-sea Decapoda is proposed for Guadeloupe Island based solely on high definition macro photographs taken during the KARUBENTHOS 2015 Expedition to the Island (R/V Antea, 7-29 June 2015). Overall, 190 species are recognized, several of which are depicted with their fresh color for the first time. Previous records in the Lesser Antilles are documented and the geographic distribution of the species in these Islands is given. The historical contribution of the steamer Blake (1878-1879) in the Lesser Antilles is emphasized. All species inventoried during KARUBENTHOS 2015 were already reported in the western Atlantic but 34 of them are new records for the Lesser Antilles and 116 are reported for the first time from Guadeloupe Island. This preliminary inventory is estimated to include about 38% of the deep-sea Decapoda potentially occurring around Guadeloupe Island.

Atmospheric Turbulence Estimates from a Pulsed Lidar

NASA Technical Reports Server (NTRS)

Pruis, Matthew J.; Delisi, Donald P.; Ahmad, Nash'at N.; Proctor, Fred H.

2013-01-01

Estimates of the eddy dissipation rate (EDR) were obtained from measurements made by a coherent pulsed lidar and compared with estimates from mesoscale model simulations and measurements from an in situ sonic anemometer at the Denver International Airport and with EDR estimates from the last observation time of the trailing vortex pair. The estimates of EDR from the lidar were obtained using two different methodologies. The two methodologies show consistent estimates of the vertical profiles. Comparison of EDR derived from the Weather Research and Forecast (WRF) mesoscale model with the in situ lidar estimates show good agreement during the daytime convective boundary layer, but the WRF simulations tend to overestimate EDR during the nighttime. The EDR estimates from a sonic anemometer located at 7.3 meters above ground level are approximately one order of magnitude greater than both the WRF and lidar estimates - which are from greater heights - during the daytime convective boundary layer and substantially greater during the nighttime stable boundary layer. The consistency of the EDR estimates from different methods suggests a reasonable ability to predict the temporal evolution of a spatially averaged vertical profile of EDR in an airport terminal area using a mesoscale model during the daytime convective boundary layer. In the stable nighttime boundary layer, there may be added value to EDR estimates provided by in situ lidar measurements.

Top-down Estimates of Isoprene Emissions in Australia Inferred from OMI Satellite Data.

NASA Astrophysics Data System (ADS)

Greenslade, J.; Fisher, J. A.; Surl, L.; Palmer, P. I.

2017-12-01

Australia is a global hotspot for biogenic isoprene emission factors predicted by process-based models such as the Model of Emissions of Gases and Aerosols from Nature (MEGAN). It is also prone to increasingly frequent temperature extremes that can drive episodically high emissions. Estimates of biogenic isoprene emissions from Australia are poorly constrained, with the frequently used MEGAN model overestimating emissions by a factor of 4-6 in some areas. Evaluating MEGAN and other models in Australia is difficult due to sparse measurements of emissions and their ensuing chemical products. In this talk, we will describe efforts to better quantify Australian isoprene emissions using top-down estimates based on formaldehyde (HCHO) observations from the OMI satellite instrument, combined with modelled isoprene to HCHO yields obtained from the GEOS-Chem chemical transport model. The OMI-based estimates are evaluated using in situ observations from field campaigns conducted in southeast Australia. We also investigate the impact on the inferred emission of horizontal resolution used for the yield calculations, particularly in regions on the boundary between low- and high-NOx chemistry. The prevalence of fire smoke plumes roughly halves the available satellite dataset over Australia for much of the year; however, seasonal averages remain robust. Preliminary results show that the top-down isoprene emissions are lower than MEGAN estimates by up to 90% in summer. The overestimates are greatest along the eastern coast, including areas surrounding Australia's major population centres in Sydney, Melbourne, and Brisbane. The coarse horizontal resolution of the model significantly affects the emissions estimates, as many biogenic emitting regions lie along narrow coastal stretches. Our results confirm previous findings that the MEGAN biogenic emission model is poorly calibrated for the Australian environment and suggests that chemical transport models driven by MEGAN are likely

Preliminary results of investigations into the use of artificial neural networks for discriminating gas chromatograph mass spectra of remote samples

NASA Technical Reports Server (NTRS)

Geller, Harold A.; Norris, Eugene; Warnock, Archibald, III

1991-01-01

Neural networks trained using mass spectra data from the National Institute of Standards and Technology (NIST) are studied. The investigations also included sample data from the gas chromatograph mass spectrometer (GCMS) instrument aboard the Viking Lander, obtained from the National Space Science Data Center. The work performed to data and the preliminary results from the training and testing of neural networks are described. These preliminary results are presented for the purpose of determining the viability of applying artificial neural networks in discriminating mass spectra samples from remote instrumentation such as the Mars Rover Sample Return Mission and the Cassini Probe.

A hierarchical estimator development for estimation of tire-road friction coefficient.

PubMed

Zhang, Xudong; Göhlich, Dietmar

2017-01-01

The effect of vehicle active safety systems is subject to the friction force arising from the contact of tires and the road surface. Therefore, an adequate knowledge of the tire-road friction coefficient is of great importance to achieve a good performance of these control systems. This paper presents a tire-road friction coefficient estimation method for an advanced vehicle configuration, four-motorized-wheel electric vehicles, in which the longitudinal tire force is easily obtained. A hierarchical structure is adopted for the proposed estimation design. An upper estimator is developed based on unscented Kalman filter to estimate vehicle state information, while a hybrid estimation method is applied as the lower estimator to identify the tire-road friction coefficient using general regression neural network (GRNN) and Bayes' theorem. GRNN aims at detecting road friction coefficient under small excitations, which are the most common situations in daily driving. GRNN is able to accurately create a mapping from input parameters to the friction coefficient, avoiding storing an entire complex tire model. As for large excitations, the estimation algorithm is based on Bayes' theorem and a simplified "magic formula" tire model. The integrated estimation method is established by the combination of the above-mentioned estimators. Finally, the simulations based on a high-fidelity CarSim vehicle model are carried out on different road surfaces and driving maneuvers to verify the effectiveness of the proposed estimation method.

A hierarchical estimator development for estimation of tire-road friction coefficient

PubMed Central

Zhang, Xudong; Göhlich, Dietmar

2017-01-01

The effect of vehicle active safety systems is subject to the friction force arising from the contact of tires and the road surface. Therefore, an adequate knowledge of the tire-road friction coefficient is of great importance to achieve a good performance of these control systems. This paper presents a tire-road friction coefficient estimation method for an advanced vehicle configuration, four-motorized-wheel electric vehicles, in which the longitudinal tire force is easily obtained. A hierarchical structure is adopted for the proposed estimation design. An upper estimator is developed based on unscented Kalman filter to estimate vehicle state information, while a hybrid estimation method is applied as the lower estimator to identify the tire-road friction coefficient using general regression neural network (GRNN) and Bayes' theorem. GRNN aims at detecting road friction coefficient under small excitations, which are the most common situations in daily driving. GRNN is able to accurately create a mapping from input parameters to the friction coefficient, avoiding storing an entire complex tire model. As for large excitations, the estimation algorithm is based on Bayes' theorem and a simplified “magic formula” tire model. The integrated estimation method is established by the combination of the above-mentioned estimators. Finally, the simulations based on a high-fidelity CarSim vehicle model are carried out on different road surfaces and driving maneuvers to verify the effectiveness of the proposed estimation method. PMID:28178332

Preliminary analysis of STS-2 entry flight data

NASA Technical Reports Server (NTRS)

1982-01-01

A preliminary analysis of the data obtained during the entry of the STS-2 flight was completed. The stability and control derivatives from STS-2 were examined. Questions still remain throughout the flight envelope and the area below Mach 3 needs more study. With three controls operating in a high gain feedback system, it is difficult to separate the individual effects of each of the controls. Analysis of the aerothermal data shows that wing structural-temperature measurements are generally repeatable and consistent with the trajectories. The measured wing upper surface temperatures are in reasonable agreement with Dryden predictions but wing lower surface temperatures are higher than Dryden predictions. Heating and heat transfer models will be adjusted to improve the temperature prediction capability for future trajectories.

Preliminary Results of an Altitude-Wind-Tunnel Investigation of an Axial-Flow Gas Turbine-Propeller Engine. 1; Performance Characteristics

NASA Technical Reports Server (NTRS)

Saari, Martin J.; Wallner, Lewis E.

1948-01-01

A preliminary investigation of an axial-flow gas turbine-propeller engine was conduxted. Performance data were obtained for engine speeds from 8000 to 13,000 rpm and altitudes from 5000 to 35,000 feet and compressor inlet ram pressure ratios from 1.00 to 1.17.

Estimating Canopy Dark Respiration for Crop Models

NASA Technical Reports Server (NTRS)

Monje Mejia, Oscar Alberto

2014-01-01

Crop production is obtained from accurate estimates of daily carbon gain.Canopy gross photosynthesis (Pgross) can be estimated from biochemical models of photosynthesis using sun and shaded leaf portions and the amount of intercepted photosyntheticallyactive radiation (PAR).In turn, canopy daily net carbon gain can be estimated from canopy daily gross photosynthesis when canopy dark respiration (Rd) is known.

46 CFR 71.50-21 - Preliminary examination requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... exclusively use divers to examine the underwater hull plating, you must arrange to have a preliminary... the predominant means to examine your vessel's hull plating, a preliminary examination and the...

Reliability of TMS phosphene threshold estimation: Toward a standardized protocol.

PubMed

Mazzi, Chiara; Savazzi, Silvia; Abrahamyan, Arman; Ruzzoli, Manuela

Phosphenes induced by transcranial magnetic stimulation (TMS) are a subjectively described visual phenomenon employed in basic and clinical research as index of the excitability of retinotopically organized areas in the brain. Phosphene threshold estimation is a preliminary step in many TMS experiments in visual cognition for setting the appropriate level of TMS doses; however, the lack of a direct comparison of the available methods for phosphene threshold estimation leaves unsolved the reliability of those methods in setting TMS doses. The present work aims at fulfilling this gap. We compared the most common methods for phosphene threshold calculation, namely the Method of Constant Stimuli (MOCS), the Modified Binary Search (MOBS) and the Rapid Estimation of Phosphene Threshold (REPT). In two experiments we tested the reliability of PT estimation under each of the three methods, considering the day of administration, participants' expertise in phosphene perception and the sensitivity of each method to the initial values used for the threshold calculation. We found that MOCS and REPT have comparable reliability when estimating phosphene thresholds, while MOBS estimations appear less stable. Based on our results, researchers and clinicians can estimate phosphene threshold according to MOCS or REPT equally reliably, depending on their specific investigation goals. We suggest several important factors for consideration when calculating phosphene thresholds and describe strategies to adopt in experimental procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

46 CFR 176.635 - Preliminary examination requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Preliminary examination requirements. 176.635 Section... (UNDER 100 GROSS TONS) INSPECTION AND CERTIFICATION Hull and Tailshaft Examinations § 176.635 Preliminary examination requirements. (a) If you exclusively use divers to examine the underwater hull plating, you must...

Online estimation of room reverberation time

NASA Astrophysics Data System (ADS)

Ratnam, Rama; Jones, Douglas L.; Wheeler, Bruce C.; Feng, Albert S.

2003-04-01

The reverberation time (RT) is an important parameter for characterizing the quality of an auditory space. Sounds in reverberant environments are subject to coloration. This affects speech intelligibility and sound localization. State-of-the-art signal processing algorithms for hearing aids are expected to have the ability to evaluate the characteristics of the listening environment and turn on an appropriate processing strategy accordingly. Thus, a method for the characterization of room RT based on passively received microphone signals represents an important enabling technology. Current RT estimators, such as Schroeder's method or regression, depend on a controlled sound source, and thus cannot produce an online, blind RT estimate. Here, we describe a method for estimating RT without prior knowledge of sound sources or room geometry. The diffusive tail of reverberation was modeled as an exponentially damped Gaussian white noise process. The time constant of the decay, which provided a measure of the RT, was estimated using a maximum-likelihood procedure. The estimates were obtained continuously, and an order-statistics filter was used to extract the most likely RT from the accumulated estimates. The procedure was illustrated for connected speech. Results obtained for simulated and real room data are in good agreement with the real RT values.

Introducing Bayesian thinking to high-throughput screening for false-negative rate estimation.

PubMed

Wei, Xin; Gao, Lin; Zhang, Xiaolei; Qian, Hong; Rowan, Karen; Mark, David; Peng, Zhengwei; Huang, Kuo-Sen

2013-10-01

High-throughput screening (HTS) has been widely used to identify active compounds (hits) that bind to biological targets. Because of cost concerns, the comprehensive screening of millions of compounds is typically conducted without replication. Real hits that fail to exhibit measurable activity in the primary screen due to random experimental errors will be lost as false-negatives. Conceivably, the projected false-negative rate is a parameter that reflects screening quality. Furthermore, it can be used to guide the selection of optimal numbers of compounds for hit confirmation. Therefore, a method that predicts false-negative rates from the primary screening data is extremely valuable. In this article, we describe the implementation of a pilot screen on a representative fraction (1%) of the screening library in order to obtain information about assay variability as well as a preliminary hit activity distribution profile. Using this training data set, we then developed an algorithm based on Bayesian logic and Monte Carlo simulation to estimate the number of true active compounds and potential missed hits from the full library screen. We have applied this strategy to five screening projects. The results demonstrate that this method produces useful predictions on the numbers of false negatives.

14 CFR 150.31 - Preliminary review: Acknowledgments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... program submitted under § 150.23, the Regional Airports Division Manager acknowledges to the airport... preliminary review, the Regional Airports Division Manager finds that the submission does not conform to the... reconsideration and development of a program in accordance with this part. (c) If, based on the preliminary review...

33 CFR 1.07-25 - Preliminary matters.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Preliminary matters. 1.07-25 Section 1.07-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL GENERAL PROVISIONS Enforcement; Civil and Criminal Penalty Proceedings § 1.07-25 Preliminary matters. (a...

33 CFR 1.07-25 - Preliminary matters.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Preliminary matters. 1.07-25 Section 1.07-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL GENERAL PROVISIONS Enforcement; Civil and Criminal Penalty Proceedings § 1.07-25 Preliminary matters. (a...

33 CFR 1.07-25 - Preliminary matters.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Preliminary matters. 1.07-25 Section 1.07-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL GENERAL PROVISIONS Enforcement; Civil and Criminal Penalty Proceedings § 1.07-25 Preliminary matters. (a...

33 CFR 1.07-25 - Preliminary matters.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Preliminary matters. 1.07-25 Section 1.07-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL GENERAL PROVISIONS Enforcement; Civil and Criminal Penalty Proceedings § 1.07-25 Preliminary matters. (a...

33 CFR 1.07-25 - Preliminary matters.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Preliminary matters. 1.07-25 Section 1.07-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL GENERAL PROVISIONS Enforcement; Civil and Criminal Penalty Proceedings § 1.07-25 Preliminary matters. (a...

Bootstrap Estimates of Standard Errors in Generalizability Theory

ERIC Educational Resources Information Center

Tong, Ye; Brennan, Robert L.

2007-01-01

Estimating standard errors of estimated variance components has long been a challenging task in generalizability theory. Researchers have speculated about the potential applicability of the bootstrap for obtaining such estimates, but they have identified problems (especially bias) in using the bootstrap. Using Brennan's bias-correcting procedures…

Gravity model development for precise orbit computations for satellite altimetry

NASA Technical Reports Server (NTRS)

Marsh, James G.; Lerch, Francis, J.; Smith, David E.; Klosko, Steven M.; Pavlis, Erricos

1986-01-01

Two preliminary gravity models developed as a first step in reaching the TOPEX/Poseidon modeling goals are discussed. They were obtained by NASA-Goddard from an analysis of exclusively satellite tracking observations. With the new Preliminary Gravity Solution-T2 model, an improved global estimate of the field is achieved with an improved description of the geoid.

No correlation between ultrasound placental grading at 31-34 weeks of gestation and a surrogate estimate of organ function at term obtained by stereological analysis.

PubMed

Yin, T T; Loughna, P; Ong, S S; Padfield, J; Mayhew, T M

2009-08-01

We test the experimental hypothesis that early changes in the ultrasound appearance of the placenta reflect poor or reduced placental function. The sonographic (Grannum) grade of placental maturity was compared to placental function as expressed by the morphometric oxygen diffusive conductance of the villous membrane. Ultrasonography was used to assess the Grannum grade of 32 placentas at 31-34 weeks of gestation. Indications for the scans included a history of previous fetal abnormalities, previous fetal growth problems or suspicion of IUGR. Placentas were classified from grade 0 (most immature) to grade III (most mature). We did not exclude smokers or complicated pregnancies as we aimed to correlate the early appearance of mature placentas with placental function. After delivery, microscopical fields on formalin-fixed, trichrome-stained histological sections of each placenta were obtained by multistage systematic uniform random sampling. Using design-based stereological methods, the exchange surface areas of peripheral (terminal and intermediate) villi and their fetal capillaries and the arithmetic and harmonic mean thicknesses of the villous membrane (maternal surface of villous trophoblast to adluminal surface of vascular endothelium) were estimated. An index of the variability in thickness of this membrane, and an estimate of its oxygen diffusive conductance, were derived secondarily as were estimates of the mean diameters and total lengths of villi and fetal capillaries. Group comparisons were drawn using analysis of variance. We found no significant differences in placental volume or composition or in the dimensions or diffusive conductances of the villous membrane. Subsequent exclusion of smokers did not alter these main findings. Grannum grades at 31-34 weeks of gestation appear not to provide reliable predictors of the functional capacity of the term placenta as expressed by the surrogate measure, morphometric diffusive conductance.

Technique for estimation of streamflow statistics in mineral areas of interest in Afghanistan

USGS Publications Warehouse

Olson, Scott A.; Mack, Thomas J.

2011-01-01

A technique for estimating streamflow statistics at ungaged stream sites in areas of mineral interest in Afghanistan using drainage-area-ratio relations of historical streamflow data was developed and is documented in this report. The technique can be used to estimate the following streamflow statistics at ungaged sites: (1) 7-day low flow with a 10-year recurrence interval, (2) 7-day low flow with a 2-year recurrence interval, (3) daily mean streamflow exceeded 90 percent of the time, (4) daily mean streamflow exceeded 80 percent of the time, (5) mean monthly streamflow for each month of the year, (6) mean annual streamflow, and (7) minimum monthly streamflow for each month of the year. Because they are based on limited historical data, the estimates of streamflow statistics at ungaged sites are considered preliminary.

[A method for obtaining redshifts of quasars based on wavelet multi-scaling feature matching].

PubMed

Liu, Zhong-Tian; Li, Xiang-Ru; Wu, Fu-Chao; Zhao, Yong-Heng

2006-09-01

The LAMOST project, the world's largest sky survey project being implemented in China, is expected to obtain 10(5) quasar spectra. The main objective of the present article is to explore methods that can be used to estimate the redshifts of quasar spectra from LAMOST. Firstly, the features of the broad emission lines are extracted from the quasar spectra to overcome the disadvantage of low signal-to-noise ratio. Then the redshifts of quasar spectra can be estimated by using the multi-scaling feature matching. The experiment with the 15, 715 quasars from the SDSS DR2 shows that the correct rate of redshift estimated by the method is 95.13% within an error range of 0. 02. This method was designed to obtain the redshifts of quasar spectra with relative flux and a low signal-to-noise ratio, which is applicable to the LAMOST data and helps to study quasars and the large-scale structure of the universe etc.

Environmental Barrier Coating (EBC) Durability Modeling; An Overview and Preliminary Analysis

NASA Technical Reports Server (NTRS)

Abdul-Aziz, A.; Bhatt, R. T.; Grady, J. E.; Zhu, D.

2012-01-01

A study outlining a fracture mechanics based model that is being developed to investigate crack growth and spallation of environmental barrier coating (EBC) under thermal cycling conditions is presented. A description of the current plan and a model to estimate thermal residual stresses in the coating and preliminary fracture mechanics concepts for studying crack growth in the coating are also discussed. A road map for modeling life and durability of the EBC and the results of FEA model(s) developed for predicting thermal residual stresses and the cracking behavior of the coating are generated and described. Further initial assessment and preliminary results showed that developing a comprehensive EBC life prediction model incorporating EBC cracking, degradation and spalling mechanism under stress and temperature gradients typically seen in turbine components is difficult. This is basically due to mismatch in thermal expansion difference between sub-layers of EBC as well as between EBC and substrate, diffusion of moisture and oxygen though the coating, and densification of the coating during operating conditions as well as due to foreign object damage, the EBC can also crack and spall from the substrate causing oxidation and recession and reducing the design life of the EBC coated substrate.

Wave Period and Coastal Bathymetry Estimations from Satellite Images

NASA Astrophysics Data System (ADS)

Danilo, Celine; Melgani, Farid

2016-08-01

We present an approach for wave period and coastal water depth estimation. The approach based on wave observations, is entirely independent of ancillary data and can theoretically be applied to SAR or optical images. In order to demonstrate its feasibility we apply our method to more than 50 Sentinel-1A images of the Hawaiian Islands, well-known for its long waves. Six wave buoys are available to compare our results with in-situ measurements. The results on Sentinel-1A images show that half of the images were unsuitable for applying the method (no swell or wavelength too small to be captured by the SAR). On the other half, 78% of the estimated wave periods are in accordance with buoy measurements. In addition, we present preliminary results of the estimation of the coastal water depth on a Landsat-8 image (with characteristics close to Sentinel-2A). With a squared correlation coefficient of 0.7 for ground truth measurement, this approach reveals promising results for monitoring coastal bathymetry.

Effect of different methods of preliminary surface treatment and magnetron sputtering on the adhesion of Si coatings

NASA Astrophysics Data System (ADS)

Borisov, D. P.; Slabodchikov, V. A.; Kuznetsov, V. M.

2017-05-01

The paper presents research results on the adhesion of Si coatings deposited by magnetron sputtering on NiTi substrates after preliminary surface treatment (cleaning and activation) with low-energy ion beams and gas discharge plasma. The adhesion properties of the coatings obtained by two methods are analyzed and compared using data of scratch and spherical abrasion tests.

Preliminary Computational Analysis of the (HIRENASD) Configuration in Preparation for the Aeroelastic Prediction Workshop

NASA Technical Reports Server (NTRS)

Chwalowski, Pawel; Florance, Jennifer P.; Heeg, Jennifer; Wieseman, Carol D.; Perry, Boyd P.

2011-01-01

This paper presents preliminary computational aeroelastic analysis results generated in preparation for the first Aeroelastic Prediction Workshop (AePW). These results were produced using FUN3D software developed at NASA Langley and are compared against the experimental data generated during the HIgh REynolds Number Aero- Structural Dynamics (HIRENASD) Project. The HIRENASD wind-tunnel model was tested in the European Transonic Windtunnel in 2006 by Aachen University0s Department of Mechanics with funding from the German Research Foundation. The computational effort discussed here was performed (1) to obtain a preliminary assessment of the ability of the FUN3D code to accurately compute physical quantities experimentally measured on the HIRENASD model and (2) to translate the lessons learned from the FUN3D analysis of HIRENASD into a set of initial guidelines for the first AePW, which includes test cases for the HIRENASD model and its experimental data set. This paper compares the computational and experimental results obtained at Mach 0.8 for a Reynolds number of 7 million based on chord, corresponding to the HIRENASD test conditions No. 132 and No. 159. Aerodynamic loads and static aeroelastic displacements are compared at two levels of the grid resolution. Harmonic perturbation numerical results are compared with the experimental data using the magnitude and phase relationship between pressure coefficients and displacement. A dynamic aeroelastic numerical calculation is presented at one wind-tunnel condition in the form of the time history of the generalized displacements. Additional FUN3D validation results are also presented for the AGARD 445.6 wing data set. This wing was tested in the Transonic Dynamics Tunnel and is commonly used in the preliminary benchmarking of computational aeroelastic software.

Conversion of the Aerodynamic Preliminary Analysis System (APAS) to an IBM PC Compatible Format

NASA Technical Reports Server (NTRS)

Kruep, John M.

1995-01-01

The conversion of the Aerodynamic Preliminary Analysis System (APAS) software from a Silicon Graphics UNIX-based platform to a DOS-based IBM PC compatible is discussed. Relevant background information is given, followed by a discussion of the steps taken to accomplish the conversion and a discussion of the type of problems encountered during the conversion. A brief comparison of aerodynamic data obtained using APAS with data from another source is also made.

Assessing Interval Estimation Methods for Hill Model ...

EPA Pesticide Factsheets

The Hill model of concentration-response is ubiquitous in toxicology, perhaps because its parameters directly relate to biologically significant metrics of toxicity such as efficacy and potency. Point estimates of these parameters obtained through least squares regression or maximum likelihood are commonly used in high-throughput risk assessment, but such estimates typically fail to include reliable information concerning confidence in (or precision of) the estimates. To address this issue, we examined methods for assessing uncertainty in Hill model parameter estimates derived from concentration-response data. In particular, using a sample of ToxCast concentration-response data sets, we applied four methods for obtaining interval estimates that are based on asymptotic theory, bootstrapping (two varieties), and Bayesian parameter estimation, and then compared the results. These interval estimation methods generally did not agree, so we devised a simulation study to assess their relative performance. We generated simulated data by constructing four statistical error models capable of producing concentration-response data sets comparable to those observed in ToxCast. We then applied the four interval estimation methods to the simulated data and compared the actual coverage of the interval estimates to the nominal coverage (e.g., 95%) in order to quantify performance of each of the methods in a variety of cases (i.e., different values of the true Hill model paramet

Preliminary experimental results of tungsten wire-array Z-pinches on primary test stand

NASA Astrophysics Data System (ADS)

Huang, Xian-Bin; Zhou, Shao-Tong; Dan, Jia-Kun; Ren, Xiao-Dong; Wang, Kun-Lun; Zhang, Si-Qun; Li, Jing; Xu, Qiang; Cai, Hong-Chun; Duan, Shu-Chao; Ouyang, Kai; Chen, Guang-Hua; Ji, Ce; Wei, Bing; Feng, Shu-Ping; Wang, Meng; Xie, Wei-Ping; Deng, Jian-Jun; Zhou, Xiu-Wen; Yang, Yi

2015-07-01

The Primary Test Stand (PTS) developed at the China Academy of Engineering Physics is a 20 TW pulsed power driver, which can deliver a ˜10 MA, 70 ns rise-time (10%-90%) current to a short-circuit load and has important applications in Z-pinch driven inertial confinement fusion and high energy density physics. Preliminary results of tungsten wire-array Z-pinch experiments on PTS are presented. The load geometries investigated include 15-mm-tall cylindrical single and nested arrays with diameter ranging from 13 mm to 30 mm, consisting of 132-300 tungsten wires with 5-10 μm in diameter. Multiple diagnostics were fielded to characterize the x-ray radiation from wire-array Z pinches. The x-ray peak power (˜50 TW) and total radiated energy (˜500 kJ) were obtained from a single 20-mm-diam array with 80-ns stagnation time. The highest x-ray peak power up to 80 TW with 2.4 ns FWHM was achieved by using a nested array with 20-mm outer diameter, and the total x-ray energy from the nested array is comparable to that of single array. Implosion velocity estimated from the time-resolved image measurement exceeds 30 cm/μs. The detailed experimental results and other findings are presented and discussed.

A feasibility test to estimate the duration of phytoextraction of heavy metals from polluted soils.

PubMed

Japenga, J; Koopmans, G F; Song, J; Römkens, P F A M

2007-01-01

The practical applicability of heavy metal (HM) phytoextraction depends heavily on its duration. Phytoextraction duration is the main cost factorfor phytoextraction, both referring to recurring economic costs during phytoextraction and to the cost of the soil having no economic value during phytoextraction. An experiment is described here, which is meant as a preliminary feasibility test before starting a phytoextraction scheme in practice, to obtain a more realistic estimate of the phytoextraction duration of a specific HM-polluted soil. In the experiment, HM-polluted soil is mixed at different ratios with unpolluted soil of comparable composition to mimic the gradual decrease of the HM content in the target HM-polluted soil during phytoextraction. After equilibrating the soil mixtures, one cropping cycle is carried out with the plant species of interest. At harvest, the adsorbed HM contents in the soil and the HM contents in the plant shoots are determined. The adsorbed HM contents in the soil are then related to the HM contents in the plant shoots by a log-log linear relationship that can then be used to estimate the phytoextraction duration of a specific HM-polluted soil. This article describes and evaluates the merits of such a feasibility experiment. Potential drawbacks regarding the accuracy of the described approach are discussed and a greenhouse-field extrapolation procedure is proposed.

Influence of Articulating Paper Thickness on Occlusal Contacts Registration: A Preliminary Report.