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1

Ground-penetrating Radar Survey (GPR)  

USGS Multimedia Gallery

USGS hydrologist conducts a ground-penetrating radar survey to investigate and characterize the shallow subsurface. The survey was conducted as part of an applied research effort by the USGS Office of Groundwater Branch of Geophysics in 2006....

2

Site survey method and apparatus  

DOEpatents

The disclosure of the invention is directed to a site survey ground vehicle based apparatus and method for automatically detecting source materials, such as radioactivity, marking the location of the source materials, such as with paint, and mapping the location of the source materials on a site. The apparatus of the invention is also useful for collecting and analyzing samples. The apparatus includes a ground vehicle, detectors mounted at the front of the ground vehicle, and individual detector supports which follow somewhat irregular terrain to allow consistent and accurate detection, and autolocation equipment. 19 figures.

Oldham, J.G.; Spencer, C.R.; Begley, C.L.; Meyer, H.R.

1991-06-18

3

Site survey method and apparatus  

DOEpatents

The disclosure of the invention is directed to a site survey ground vehicle based apparatus and method for automatically detecting source materials, such as radioactivity, marking the location of the source materials, such as with paint, and mapping the location of the source materials on a site. The apparatus of the invention is also useful for collecting and analyzing samples. The apparatus includes a ground vehicle, detectors mounted at the front of the ground vehicle, and individual detector supports which follow somewhat irregular terrain to allow consistent and accurate detection, and autolocation equipment.

Oldham, James G. (Albuquerque, NM); Spencer, Charles R. (Boise, ID); Begley, Carl L. (Albuquerque, NM); Meyer, H. Robert (Albuquerque, NM)

1991-06-18

4

Ground-penetrating radar methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ground-penetrating radar geophysical methods are finding greater and greater use in agriculture. With the ground-penetrating radar (GPR) method, an electromagnetic radio energy (radar) pulse is directed into the subsurface, followed by measurement of the elapsed time taken by the radar signal as it ...

5

Assessing modern ground survey methods and airborne laser scanning for digital terrain modelling: A case study from the Lake District, England  

NASA Astrophysics Data System (ADS)

This paper compares the applicability of three ground survey methods for modelling terrain: one man electronic tachymetry (TPS), real time kinematic GPS (GPS), and terrestrial laser scanning (TLS). Vertical accuracy of digital terrain models (DTMs) derived from GPS, TLS and airborne laser scanning (ALS) data is assessed. Point elevations acquired by the four methods represent two sections of a mountainous area in Cumbria, England. They were chosen so that the presence of non-terrain features is constrained to the smallest amount. The vertical accuracy of the DTMs was addressed by subtracting each DTM from TPS point elevations. The error was assessed using exploratory measures including statistics, histograms, and normal probability plots. The results showed that the internal measurement accuracy of TPS, GPS, and TLS was below a centimetre. TPS and GPS can be considered equally applicable alternatives for sampling the terrain in areas accessible on foot. The highest DTM vertical accuracy was achieved with GPS data, both on sloped terrain (RMSE 0.16 m) and flat terrain (RMSE 0.02 m). TLS surveying was the most efficient overall but veracity of terrain representation was subject to dense vegetation cover. Therefore, the DTM accuracy was the lowest for the sloped area with dense bracken (RMSE 0.52 m) although it was the second highest on the flat unobscured terrain (RMSE 0.07 m). ALS data represented the sloped terrain more realistically (RMSE 0.23 m) than the TLS. However, due to a systematic bias identified on the flat terrain the DTM accuracy was the lowest (RMSE 0.29 m) which was above the level stated by the data provider. Error distribution models were more closely approximated by normal distribution defined using median and normalized median absolute deviation which supports the use of the robust measures in DEM error modelling and its propagation.

Gallay, Michal; Lloyd, Christopher D.; McKinley, Jennifer; Barry, Lorraine

2013-02-01

6

Quantifying Stream Habitat: Relative Effort Versus Quality of Competing Remote Sensing & Ground-Based Survey Techniques  

Microsoft Academic Search

Numerous field and analytical methods exist to assist in the quantification of the quantity and quality of in-stream habitat for salmonids. These methods range from field sketches or `tape and stick' ground-based surveys, through to spatially explicit topographic and aerial photographic surveys from a mix of ground-based and remotely sensed airborne platforms. Although some investigators have assessed the quality of

S. G. Bangen; J. M. Wheaton; N. Bouwes

2010-01-01

7

6. Historic American Buildings Survey PHOTOCOPY OF BLUEPRINTS OF GROUNDS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Historic American Buildings Survey PHOTOCOPY OF BLUEPRINTS OF GROUNDS October 20, 1887 Original in National Archives, Washington, D.C. - U. S. Marine Hospital & Gates, 800 Saint Anthony Street, Mobile, Mobile County, AL

8

29. Historic American Buildings Survey Ground floor Plan Framing ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

29. Historic American Buildings Survey Ground floor Plan - Framing and seating Original Plan by Benjamin H. Latrobe 1816 Copy of plan in Church Office - St. John's Church, Sixteenth & H Streets Northwest, Washington, District of Columbia, DC

9

Ground surveying in Surprise Valley, California  

USGS Multimedia Gallery

U.S. Geological Survey researcher Noah Athens secures a magnetometer pack onto Stanford graduate student Melissa Pandika, who blogged the team’s first year’s research for USGS in Surprise Valley, Modoc County, Calif., in 2012. Traditionally, magnetometric surveying has been done on foot ...

10

July 1973 ground survey of active Central American volcanoes  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Ground survey has shown that thermal anomalies of various sizes associated with volcanic activity at several Central American volcanoes should be detectable from Skylab. Anomalously hot areas of especially large size (greater than 500 m in diameter) are now found at Santiaguito and Pacaya volcanoes in Guatemala and San Cristobal in Nicaragua. Smaller anomalous areas are to be found at least seven other volcanoes. This report is completed after ground survey of eleven volcanoes and ground-based radiation thermometry mapping at these same points.

Stoiber, R. E. (principal investigator); Rose, W. I., Jr.

1973-01-01

11

Quantifying Stream Habitat: Relative Effort Versus Quality of Competing Remote Sensing & Ground-Based Survey Techniques  

NASA Astrophysics Data System (ADS)

Numerous field and analytical methods exist to assist in the quantification of the quantity and quality of in-stream habitat for salmonids. These methods range from field sketches or ‘tape and stick’ ground-based surveys, through to spatially explicit topographic and aerial photographic surveys from a mix of ground-based and remotely sensed airborne platforms. Although some investigators have assessed the quality of specific individual survey methods, the inter-comparison of competing techniques across a diverse range of habitat conditions (wadeable headwater channels to non-wadeable mainstem channels) has not yet been elucidated. In this study, we seek to quantify relative quality (i.e. accuracy, precision, extent) of habitat metrics and inventories derived from different ground-based and remotely sensed surveys of varying degrees of sophistication, as well as enumerate the effort and cost in completing the surveys. Over the summer of 2010, seven sample reaches of varying habitat complexity were surveyed in the Lemhi River Basin, Idaho, USA. Three different traditional (“stick and tape”) survey techniques were used, including a variant using map-grade GPS. Complete topographic/bathymetric surveys were attempted at each site using separate rtkGPS, total station, ground-based LiDaR, boat-based echo-sounding (w/ ADCP), traditional airborne LiDaR, and imagery-based spectral methods. Separate, georectified aerial imagery surveys were acquired using a tethered blimp, a drone UAV, and a traditional fixed-wing aircraft. Preliminary results from the surveys highlight that no single technique works across the full range of conditions where stream habitat surveys are needed. The results are helpful for understanding the strengths and weaknesses of each approach in specific conditions, and how a hybrid of data acquisition methods can be used to build a more complete quantification of habitat conditions in rivers.

Bangen, S. G.; Wheaton, J. M.; Bouwes, N.

2010-12-01

12

Generating Ground Reference Data for a Global Impervious Surface Survey  

NASA Technical Reports Server (NTRS)

We are developing an approach for generating ground reference data in support of a project to produce a 30m impervious cover data set of the entire Earth for the years 2000 and 2010 based on the Landsat Global Land Survey (GLS) data set. Since sufficient ground reference data for training and validation is not available from ground surveys, we are developing an interactive tool, called HSegLearn, to facilitate the photo-interpretation of 1 to 2 m spatial resolution imagery data, which we will use to generate the needed ground reference data at 30m. Through the submission of selected region objects and positive or negative examples of impervious surfaces, HSegLearn enables an analyst to automatically select groups of spectrally similar objects from a hierarchical set of image segmentations produced by the HSeg image segmentation program at an appropriate level of segmentation detail, and label these region objects as either impervious or nonimpervious.

Tilton, James C.; De Colstoun, Eric Brown; Wolfe, Robert E.; Tan, Bin; Huang, Chengquan

2012-01-01

13

Simulating the Performance of Ground-Based Optical Asteroid Surveys  

NASA Astrophysics Data System (ADS)

We are developing a set of asteroid survey simulation tools in order to estimate the capability of existing and planned ground-based optical surveys, and to test a variety of possible survey cadences and strategies. The survey simulator is composed of several layers, including a model population of solar system objects and an orbital integrator, a site-specific atmospheric model (including inputs for seeing, haze and seasonal cloud cover), a model telescope (with a complete optical path to estimate throughput), a model camera (including FOV, pixel scale, and focal plane fill factor) and model source extraction and moving object detection layers with tunable detection requirements. We have also developed a flexible survey cadence planning tool to automatically generate nightly survey plans. Inputs to the cadence planner include camera properties (FOV, readout time), telescope limits (horizon, declination, hour angle, lunar and zenithal avoidance), preferred and restricted survey regions in RA/Dec, ecliptic, and Galactic coordinate systems, and recent coverage by other asteroid surveys. Simulated surveys are created for a subset of current and previous NEO surveys (LINEAR, Pan-STARRS and the three Catalina Sky Survey telescopes), and compared against the actual performance of these surveys in order to validate the model’s performance. The simulator tracks objects within the FOV of any pointing that were not discovered (e.g. too few observations, too trailed, focal plane array gaps, too fast or slow), thus dividing the population into “discoverable” and “discovered” subsets, to inform possible survey design changes. Ongoing and future work includes generating a realistic “known” subset of the model NEO population, running multiple independent simulated surveys in coordinated and uncoordinated modes, and testing various cadences to find optimal strategies for detecting NEO sub-populations. These tools can also assist in quantifying the efficiency of novel yet unverified survey cadences (e.g. the baseline LSST cadence) that sparsely spread the observations required for detection over several days or weeks.

Christensen, Eric J.; Shelly, Frank C.; Gibbs, Alex R.; Grauer, Albert D.; Hill, Richard E.; Johnson, Jess A.; Kowalski, Richard A.; Larson, Stephen M.

2014-11-01

14

Mapping forest canopy gaps using air-photo interpretation and ground surveys  

USGS Publications Warehouse

Canopy gaps are important structural components of forested habitats for many wildlife species. Recent improvements in the spatial accuracy of geographic information system tools facilitate accurate mapping of small canopy features such as gaps. We compared canopy-gap maps generated using ground survey methods with those derived from air-photo interpretation. We found that maps created from high-resolution air photos were more accurate than those created from ground surveys. Errors of omission were 25.6% for the ground-survey method and 4.7% for the air-photo method. One variable of inter est in songbird research is the distance from nests to gap edges. Distances from real and simulated nests to gap edges were longer using the ground-survey maps versus the air-photo maps, indicating that gap omission could potentially bias the assessment of spatial relationships. If research or management goals require location and size of canopy gaps and specific information about vegetation structure, we recommend a 2-fold approach. First, canopy gaps can be located and the perimeters defined using 1:15,000-scale or larger aerial photographs and the methods we describe. Mapped gaps can then be field-surveyed to obtain detailed vegetation data.

Fox, T.J.; Knutson, M.G.; Hines, R.K.

2000-01-01

15

Towards a Formally Grounded Software Development Method  

E-print Network

Towards a Formally Grounded Software Development Method Christine Choppy a Gianna Reggio b a LIPN a companion method that helps the user to understand the system to be developed, and to write, so as to ``make the best of both formal and informal worlds''. We developed this method

Choppy, Christine

16

Plating methods, a survey  

NASA Technical Reports Server (NTRS)

Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

Berkowitz, J. B.; Emerson, N. H.

1972-01-01

17

Straussian Grounded-Theory Method: An Illustration  

ERIC Educational Resources Information Center

This paper demonstrates the benefits and application of Straussian Grounded Theory method in conducting research in complex settings where parameters are poorly defined. It provides a detailed illustration on how this method can be used to build an internationalization theory. To be specific, this paper exposes readers to the behind-the-scene work…

Thai, Mai Thi Thanh; Chong, Li Choy; Agrawal, Narendra M.

2012-01-01

18

Comparing LiDAR-Generated to Ground-Surveyed Channel Cross-Sectional Profiles  

E-print Network

and Ranging (LiDAR) holds promise to provide an alternative to traditional ground-based survey methods on Cal Poly's Swanton Pacific Ranch, near Santa Cruz, CA. Three LiDAR datasets were compared in this study, with flights in 2002, 2008, and 2010, a period of rapid improvement in LiDAR technology. Visual

Standiford, Richard B.

19

A GROUND-BASED 21 cm BARYON ACOUSTIC OSCILLATION SURVEY  

SciTech Connect

Baryon acoustic oscillations (BAO) provide a robust standard ruler with which to measure the acceleration of the universe. The BAO feature has so far been detected in optical galaxy surveys. Intensity mapping of neutral hydrogen emission with a ground-based radio telescope provides another promising window for measuring BAO at redshifts of order unity for relatively low cost. While the cylindrical radio telescope (CRT) proposed for these measurements will have excellent redshift resolution, it will suffer from poor angular resolution (arcminutes at best). We investigate the effect of angular resolution on the standard ruler test with BAO, using the Dark Energy Task Force Figure of Merit (FoM) as a benchmark. We then extend the analysis to include variations in the parameters characterizing the telescope and the underlying physics. Finally, we optimize the survey parameters (holding total cost fixed) and present an example of a CRT BAO survey that is competitive with Stage III dark energy experiments. The tools developed here form the backbone of a publicly available code that can be used to obtain estimates of cost and FoM for any set of survey parameters.

Seo, Hee-Jong; Dodelson, Scott; Marriner, John; Mcginnis, Dave; Stebbins, Albert; Stoughton, Chris; Vallinotto, Alberto, E-mail: sheejong@fnal.go [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510-5011 (United States)

2010-09-20

20

Appendix of Surveys from the Provider Survey Methods Workshop  

Cancer.gov

In November 2010, ARP sponsored a Provider Survey Methods Workshop to review and discuss current methodologies in designing and fielding large-scale surveys of physicians and medical group practices. The workshop included a review of methods used in fielding and reporting on large-scale provider surveys over the decade 2000-2010. The following is an Appendix of the 117 surveys included in the review.

21

40 CFR 141.401 - Sanitary surveys for ground water systems.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Sanitary surveys for ground water systems. 141.401 Section 141.401...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2010-07-01

22

40 CFR 141.401 - Sanitary surveys for ground water systems.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Sanitary surveys for ground water systems. 141.401 Section 141.401...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2011-07-01

23

40 CFR 141.401 - Sanitary surveys for ground water systems.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Sanitary surveys for ground water systems. 141.401 Section 141.401...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2013-07-01

24

40 CFR 141.401 - Sanitary surveys for ground water systems.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Sanitary surveys for ground water systems. 141.401 Section 141.401...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2012-07-01

25

40 CFR 141.401 - Sanitary surveys for ground water systems.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Sanitary surveys for ground water systems. 141.401 Section 141.401...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2014-07-01

26

Local Environmental Characterization using Gamma Ground Survey Network  

NASA Astrophysics Data System (ADS)

Inexpensive gamma detectors with GPS and wireless communications have been developed and installed to provide a ground survey network for detection of environmental levels of gamma radiation from naturally occurring events (i.e. radon, lightening, solar flares, etc.) and unintended gamma radiation on the battlefield and along transport routes. Signals from lightening and cosmic rays have pulse widths less than 100 us. Pedestrian borne and vehicle borne radiation sources have signatures from millseconds to seconds. The large energy associated with solar initiated disruptions (10^20J) generates a variety of ground level events that can last for hours. Data collected during the 24/7 operation of this gamma network is compared to xray, electron, and ion flux from satellite sensors. Local rainfall data is also utilized to make comparisons to local radon intensity levels. This paper will discuss the time and intensity correlations with corroborating environmental data. If the gamma signals characteristics from local environments and space-based environments can be described with enough detail, it is hoped that automated warning of unexpected radiation events can offer early warning protection to power and energy grid avoiding potentially damaging surges as well as offer local radiation health warning as necessary.

Litz, Marc; Burns, David; Katsis, Dimos; Carroll, James

2013-04-01

27

TESTING GROUND BASED GEOPHYSICAL TECHNIQUES TO REFINE ELECTROMAGNETIC SURVEYS NORTH OF THE 300 AREA HANFORD WASHINGTON  

SciTech Connect

Airborne electromagnetic (AEM) surveys were flown during fiscal year (FY) 2008 within the 600 Area in an attempt to characterize the underlying subsurface and to aid in the closure and remediation design study goals for the 200-PO-1 Groundwater Operable Unit (OU). The rationale for using the AEM surveys was that airborne surveys can cover large areas rapidly at relatively low costs with minimal cultural impact, and observed geo-electrical anomalies could be correlated with important subsurface geologic and hydrogeologic features. Initial interpretation of the AEM surveys indicated a tenuous correlation with the underlying geology, from which several anomalous zones likely associated with channels/erosional features incised into the Ringold units were identified near the River Corridor. Preliminary modeling resulted in a slightly improved correlation but revealed that more information was required to constrain the modeling (SGW-39674, Airborne Electromagnetic Survey Report, 200-PO-1 Groundwater Operable Unit, 600 Area, Hanford Site). Both time-and frequency domain AEM surveys were collected with the densest coverage occurring adjacent to the Columbia River Corridor. Time domain surveys targeted deeper subsurface features (e.g., top-of-basalt) and were acquired using the HeliGEOTEM{reg_sign} system along north-south flight lines with a nominal 400 m (1,312 ft) spacing. The frequency domain RESOLVE system acquired electromagnetic (EM) data along tighter spaced (100 m [328 ft] and 200 m [656 ft]) north-south profiles in the eastern fifth of the 200-PO-1 Groundwater OU (immediately adjacent to the River Corridor). The overall goal of this study is to provide further quantification of the AEM survey results, using ground based geophysical methods, and to link results to the underlying geology and/or hydrogeology. Specific goals of this project are as follows: (1) Test ground based geophysical techniques for the efficacy in delineating underlying geology; (2) Use ground measurements to refine interpretations of AEM data; and (3) Improve the calibration and correlation of AEM information. The potential benefits of this project are as follows: (1) Develop a tool to map subsurface units at the Hanford Site in a rapid and cost effective manner; (2) Map groundwater pathways within the River Corridor; and (3) Aid development of the conceptual site model. If anomalies observed in the AEM data can be correlated with subsurface geology, then the rapid scanning and non-intrusive capabilities provided by the airborne surveys can be used at the Hanford Site to screen for areas that warrant further investigation.

PETERSEN SW

2010-12-02

28

Image Analysis Compared with Other Methods for Measuring Ground Cover  

Microsoft Academic Search

Ground cover is a key indicator of rangeland health but conventional methods for measuring ground cover are labor intensive. Analysis of digital images has the potential to reduce ground-cover-measurement labor requirements. We compared cover measurements by image analyses of digital images (sensor resolution = 0.97 mm\\/pixel ground sample distance) with measurements derived from a laser point frame, and from two transect methods. We

D. Terrance Booth; Samuel E. Cox; Charlie Fifield; Mike Phillips; Nathan Williamson

2005-01-01

29

TESD: a novel ground truth estimation method  

NASA Astrophysics Data System (ADS)

Knowledge of the exact shape of a lesion, or ground truth (GT), is necessary for algorithm validation, measurement metric analysis, accurate size estimation. When multiple readers provide their documentations of a lesion that can ultimately be described with occupancy regions, estimating the unknown GT is achieved by aptly merging those occupancy regions into a single outcome. Several methods are already available but, even when they consider the spatial location of pixels, e.g. thresholded probability-map (TPM) or STAPLE, pixels are assumed spatially independent (even when STAPLE proposes a hidden-Markov-random-field fix). In this paper we propose Truth Estimate from Self Distances (TESD): a new voting scheme, for all the voxels inside and outside the occupancy region, in order to take in account three key characteristics: (a) critical shape conformations, like holes or spikes, that are defined by the reciprocally surrounding pixels, (b) marking co-locations, meaning the closeness without intersection of one reader's marking to other readers' ones and c) the three-dimensionality of lesions as imaged by CT scanners. In TESD each voxel is labeled into four categories according to its signed distance transform and then the labeled images are combined with a center of gravity method to provide the GT estimation. This theoretical approach was validated on a subset of the publicly available Lung Image Database Consortium archive, where a total of 35 nodules documented on 26 scans by all four radiologists were available. The results obtained are reasonable estimates, with GT obtained close to TPM and STAPLE; at the same time this method is not limited to the intersections of readers' marked regions.

Biancardi, A. M.; Reeves, A. P.

2009-02-01

30

30 CFR 75.703-1 - Approved method of grounding.  

Code of Federal Regulations, 2011 CFR

...75.703-1 Approved method of grounding. In instances where the metal frames both of an offtrack direct-current machine and of the metal frames of its component parts are grounded to the same grounding medium the requirements of §...

2011-07-01

31

30 CFR 75.703-1 - Approved method of grounding.  

Code of Federal Regulations, 2014 CFR

...75.703-1 Approved method of grounding. In instances where the metal frames both of an offtrack direct-current machine and of the metal frames of its component parts are grounded to the same grounding medium the requirements of §...

2014-07-01

32

30 CFR 75.703-1 - Approved method of grounding.  

Code of Federal Regulations, 2010 CFR

...75.703-1 Approved method of grounding. In instances where the metal frames both of an offtrack direct-current machine and of the metal frames of its component parts are grounded to the same grounding medium the requirements of §...

2010-07-01

33

30 CFR 75.703-1 - Approved method of grounding.  

Code of Federal Regulations, 2012 CFR

...75.703-1 Approved method of grounding. In instances where the metal frames both of an offtrack direct-current machine and of the metal frames of its component parts are grounded to the same grounding medium the requirements of §...

2012-07-01

34

30 CFR 75.703-1 - Approved method of grounding.  

Code of Federal Regulations, 2013 CFR

...75.703-1 Approved method of grounding. In instances where the metal frames both of an offtrack direct-current machine and of the metal frames of its component parts are grounded to the same grounding medium the requirements of §...

2013-07-01

35

The Erosion of a Method: Examples from Grounded Theory  

ERIC Educational Resources Information Center

Since its original inception in the 1960s grounded theory has been widely used by many qualitative researchers. However, recently epistemologically different versions of grounded theory have been presented and this epistemological diversity among grounded theorists and the erosion of the method will be the major focus of this paper. The first…

Greckhamer, Thomas; Koro-Ljungberg, Mirka

2005-01-01

36

Generating Ground Reference Data for a Global Impervious Surface Survey  

NASA Technical Reports Server (NTRS)

We are engaged in a project to produce a 30m impervious cover data set of the entire Earth for the years 2000 and 2010 based on the Landsat Global Land Survey (GLS) data set. The GLS data from Landsat provide an unprecedented opportunity to map global urbanization at this resolution for the first time, with unprecedented detail and accuracy. Moreover, the spatial resolution of Landsat is absolutely essential to accurately resolve urban targets such as buildings, roads and parking lots. Finally, with GLS data available for the 1975, 1990, 2000, and 2005 time periods, and soon for the 2010 period, the land cover/use changes due to urbanization can now be quantified at this spatial scale as well. Our approach works across spatial scales using very high spatial resolution commercial satellite data to both produce and evaluate continental scale products at the 30m spatial resolution of Landsat data. We are developing continental scale training data at 1m or so resolution and aggregating these to 30m for training a regression tree algorithm. Because the quality of the input training data are critical, we have developed an interactive software tool, called HSegLearn, to facilitate the photo-interpretation of high resolution imagery data, such as Quickbird or Ikonos data, into an impervious versus non-impervious map. Previous work has shown that photo-interpretation of high resolution data at 1 meter resolution will generate an accurate 30m resolution ground reference when coarsened to that resolution. Since this process can be very time consuming when using standard clustering classification algorithms, we are looking at image segmentation as a potential avenue to not only improve the training process but also provide a semi-automated approach for generating the ground reference data. HSegLearn takes as its input a hierarchical set of image segmentations produced by the HSeg image segmentation program [1, 2]. HSegLearn lets an analyst specify pixel locations as being either positive or negative examples, and displays a classification of the study area based on these examples. For our study, the positive examples are examples of impervious surfaces and negative examples are examples of non-impervious surfaces. HSegLearn searches the hierarchical segmentation from HSeg for the coarsest level of segmentation at which selected positive example locations do not conflict with negative example locations and labels the image accordingly. The negative example regions are always defined at the finest level of segmentation detail. The resulting classification map can be then further edited at a region object level using the previously developed HSegViewer tool [3]. After providing an overview of the HSeg image segmentation program, we provide a detailed description of the HSegLearn software tool. We then give examples of using HSegLearn to generate ground reference data and conclude with comments on the effectiveness of the HSegLearn tool.

Tilton, James C.; deColstoun, Eric Brown; Wolfe, Robert E.; Tan, Bin; Huang, Chengquan

2012-01-01

37

The Detection of Terrestrial Planets via Gravitational Microlensing: Space vs. Ground-based Surveys  

E-print Network

I compare an aggressive ground-based gravitational microlensing survey for terrestrial planets to a space-based survey. The Ground-based survey assumes a global network of very wide field-of-view ~2m telescopes that monitor fields in the central Galactic bulge. I find that such a space-based survey is ~100 times more effective at detecting terrestrial planets in Earth-like orbits. The poor sensitivity of the ground-based surveys to low-mass planets is primarily due to the fact that the main sequence source stars are unresolved in ground-based images of the Galactic bulge. This gives rise to systematic photometry errors that preclude the detection of most of the planetary light curve deviations for low mass planets.

David P. Bennett

2004-04-05

38

The Neural Network Method of Corrosion Diagnosis for Grounding Grid  

SciTech Connect

Safety of persons, protection of equipment and continuity of power supply are the main objectives of the grounding system of a large electrical installation. For its accurate working status, it is essential to determine every branch resistance in the system. In this paper, we present a neural network method of corrosion diagnosis for the grounding grid based on the neural network theory. The feasibility of this method is discussed by means of its application to a simulant grounding grid.

Hou Zaien [School of Science, Shaanxi University of Sci. and Tech., Xi'an, 710021 (China); Duan Fujian [School of Science, Guilin University of Electronic Tech., Guilin, 541004 (China); Zhang Kecun [School of Science, Xi'an Jiaotong University, Xi'an, 710049 (China)

2008-11-06

39

A simplified method for calculating the substation grounding grid resistance  

Microsoft Academic Search

A simple and accurate formula for calculating the grounding grid resistance is proposed in this paper. This method is based on a theoretical manipulation of the numerical moment method and of the current image. The formula is dependent on the substation grounding grid design, such as grid depth, grid size, number of meshes, grid-conductor diameter, etc. A comparison study is

Y. L. Chow; M. M. A. Salama

1994-01-01

40

Calibration of the DRASTIC ground water vulnerability mapping method.  

PubMed

Ground water vulnerability maps developed using the DRASTIC method have been produced in many parts of the world. Comparisons of those maps with actual ground water quality data have shown that the DRASTIC method is typically a poor predictor of ground water contamination. This study significantly improved the effectiveness of a modified DRASTIC ground water vulnerability map by calibrating the point rating schemes to actual ground water quality data by using nonparametric statistical techniques and a geographic information system. Calibration was performed by comparing data on nitrite plus nitrate as nitrogen (NO2 + NO3-N) concentrations in ground water to land-use, soils, and depth to first-encountered ground water data. These comparisons showed clear statistical differences between NO2 + NO3-N concentrations and the various categories. Ground water probability point ratings for NO2 + NO3-N contamination were developed from the results of these comparisons, and a probability map was produced. This ground water probability map was then correlated with an independent set of NO2 + NO3-N data to demonstrate its effectiveness in predicting elevated NO2 + NO3-N concentrations in ground water. This correlation demonstrated that the probability map was effective, but a vulnerability map produced with the uncalibrated DRASTIC method in the same area and using the same data layers was not effective. Considerable time and expense have been out-laid to develop ground water vulnerability maps with the DRASTIC method. This study demonstrates a cost-effective method to improve and verify the effectiveness of ground water vulnerability maps. PMID:11447862

Rupert, M G

2001-01-01

41

Calibration of the DRASTIC ground water vulnerability mapping method  

USGS Publications Warehouse

Ground water vulnerability maps developed using the DRASTIC method have been produced in many parts of the world. Comparisons of those maps with actual ground water quality data have shown that the DRASTIC method is typically a poor predictor of ground water contamination. This study significantly improved the effectiveness of a modified DRASTIC ground water vulnerability map by calibrating the point rating schemes to actual ground water quality data by using nonparametric statistical techniques and a geographic information system. Calibration was performed by comparing data on nitrite plus nitrate as nitrogen (NO2 + NO3-N) concentrations in ground water to land-use, soils, and depth to first-encountered ground water data. These comparisons showed clear statistical differences between NO2 + NO3-N concentrations and the various categories. Ground water probability point ratings for NO2 + NO3-N contamination were developed from the results of these comparisons, and a probability map was produced. This ground water probability map was then correlated with an independent set of NO2 + NO3-N data to demonstrate its effectiveness in predicting elevated NO2 + NO3-N concentrations in ground water. This correlation demonstrated that the probability map was effective, but a vulnerability map produced with the uncalibrated DRASTIC method in the same area and using the same data layers was not effective. Considerable time and expense have been outlaid to develop ground water vulnerability maps with the DRASTIC method. This study demonstrates a cost-effective method to improve and verify the effectiveness of ground water vulnerability maps.

Rupert, M.G.

2001-01-01

42

Methods of extending signatures and training without ground information. [data processing, pattern recognition  

NASA Technical Reports Server (NTRS)

Methods of performing signature extension, using LANDSAT-1 data, are explored. The emphasis is on improving the performance and cost-effectiveness of large area wheat surveys. Two methods were developed: ASC, and MASC. Two methods, Ratio, and RADIFF, previously used with aircraft data were adapted to and tested on LANDSAT-1 data. An investigation into the sources and nature of between scene data variations was included. Initial investigations into the selection of training fields without in situ ground truth were undertaken.

Henderson, R. G.; Thomas, G. S.; Nalepka, R. F.

1975-01-01

43

Comparison of helicopter and ground surveys for North American elk Cervus elaphus and mule deer Odocoileus hemionus population composition  

USGS Publications Warehouse

Both ground and helicopter surveys are commonly used to collect sex and age composition data for ungulates. Little attention has been paid, however, to whether data collected by each technique are similar. We compared helicopter and ground composition data for both elk Cervus elaphus and mule deer Odocoileus hemionus across a variety of habitats in the state of Washington, USA. We found that ground and helicopter counts differed (P's < 0.002) consistently in male age structure estimates for elk, and that the two survey methods differed in estimates of adult sex ratios for mule deer (P = 0.023). Counts from helicopters provided larger sample sizes, tended to be more consistent annually in their results, and were corroborated by other demographic studies of the test populations. We conclude that helicopter and ground surveys differ for male age structure and perhaps male:female ratios, but are similar for young:female ratios. Managers should maintain a standardized technique using the same survey vehicle for trend analysis of composition data.

Bender, L.C.; Myers, W.L.; Gould, W.R.

2003-01-01

44

On Farmers’ Ground: Wisconsin Dairy Farm Nutrient Management Survey Questionnaire  

Technology Transfer Automated Retrieval System (TEKTRAN)

This questionnaire was used during quarterly, face-to-face interviews with the fifty-four Wisconsin dairy farmers who participated in the ‘On Farmers’ Ground’ nutrient management research project. It was designed to systematically and consistently compile information on herd size and composition, l...

45

Magnetic resonance sounding: new method for ground water assessment.  

PubMed

The advantage of magnetic resonance sounding (MRS) as compared to other classical geophysical methods is in its water selective approach and reduced ambiguity in determination of subsurface free water content and hydraulic properties of the media due to the nuclear magnetic resonance (NMR) principle applied. Two case examples are used to explain how hydrogeological parameters are obtained from an MRS survey. The first case example in Delft (the Netherlands) is a multiaquifer system characterized by large signal to noise ratio (S/N = 73), with a 24 m thick, shallow sand aquifer, confined by a 15 m thick clay layer. For the shallow aquifer, a very good match between MRS and borehole data was obtained with regard to effective porosity n(e) approximately 28% and specific drainage S(d) approximately 20%. The MRS interpretation at the level deeper than 39 m was disturbed by signal attenuation in the low resistivity (approximately 10 omega(m)) media. The second case of Serowe (Botswana) shows a fractured sandstone aquifer where hydrogeological parameters are well defined at depth > 74 m below ground surface despite quite a low S/N = 0.9 ratio, thanks to the negligible signal attenuation in the resistive environment. Finally, capabilities and limitations of the MRS technology are reviewed and discussed. MRS can contribute to subsurface hydrostratigraphy description, hydrogeological system parameterization, and improvement of well siting. The main limitations are survey dependence upon the value of the S/N ratio, signal attenuation in electrically conductive environments, nonuniformity of magnetic field, and some instrumental limitations. At locations sufficiently resistive to disregard the signal attenuation problems, the MRS S/N ratio determines how successfully MRS data can be acquired. Both signal and noise vary spatially; therefore, world scale maps providing guidelines on spatial variability of signal and noise are presented and their importance with respect to the MRS survey results is discussed. The noise varies also temporally; therefore, its diurnal and seasonal variability impact upon the MRS survey is covered as well. PMID:15035592

Lubczynski, M; Roy, J

2004-01-01

46

Image registration methods: a survey  

Microsoft Academic Search

This paper aims to present a review of recent as well as classic image registration methods. Image registration is the process of overlaying images (two or more) of the same scene taken at different times, from different viewpoints, and\\/or by different sensors. The registration geometrically align two images (the reference and sensed images). The reviewed approaches are classified according to

Barbara Zitova ´; Jan Flusser

2003-01-01

47

A survey of aftbody flow prediction methods  

NASA Technical Reports Server (NTRS)

A survey of computational methods used in the calculation of nozzle aftbody flows is presented. One class of methods reviewed are those which patch together solutions for the inviscid, boundary layer, and plume flow regions. The second class of methods reviewed are those which computationally solve the Navier Stokes equations over nozzle aftbodies with jet exhaust flow. Computed results from the methods are compared with experiment. Advantages and disadvantages of the various methods are discussed along with opportunities for further development of these methods.

Putnam, L. E.; Mace, J.

1981-01-01

48

Comparison of helicopter and ground surveys of waterfowl broods in southern Ontario  

USGS Publications Warehouse

Managers often employ aerial survey information to manage waterfowl. Results of surveys by helicopter and from elevated platforms were compared to determine the accuracy of helicopters to detect waterfowl broods on beaver ponds in southern Ontario in 1996 and 1997. Fewer broods were detected from the helicopter than by observers in elevated platforms at wetland margins. When broods were detected by helicopter crews, >90% were correctly enumerated and >80% were correctly aged. A second helicopter survey, the day following the first survey, did not change the Visibility Correction Factor (VCF) substantially (1.79 vs. 1.53). Data from the 2 helicopter surveys combined (without ground counts) resulted in greater VCFs (2.17) than when a single helicopter survey and ground count was used (VCF = 1.79). In general, VCFs for most waterfowl broods were lower in forested or closed (emergent and scrub-shrub) wetland habitats than on open wetlands. When multiple broods were present on a wetland, sightability of the additional broods (second, third, etc.) was lower for the helicopter crew than ground crew. Surveys by helicopter are likely most useful to develop indices for waterfowl broods of diver species in large inaccessible areas. If accurate information is required on dabbler brood densities, age, and number of ducklings, quiet observation by crews in elevated platforms should be used.

Gabor, T.S.; Longcore, J.R.; Murkin, H.R.; Arnason, A.N.

2000-01-01

49

Study on Tunnel-ground Controlled Source Electromagnetic Method  

NASA Astrophysics Data System (ADS)

In order to carry out 3D exploration of deeper mineral ores and overcome the difficulty and improve the accuracy of ores exploration, we will develop artificial source tunnel(wells) - ground 3D detection technology of resistivity parameter, which technology can excite ore body in multiple directions and have the advantage of obtaining plenteous electrical information. According to current literature, achievements on Tunnel-ground Electromagnetic Method are mainly electromagnetic imaging technology of inter-well and well-ground polarization method. There are few referenced experiences about tunnel-ground controlled source electromagnetic method. So, in order to get to know about this technology, it is necessary to carry out the numerical simulation of electromagnetic field of controlled source tunnel-ground electromagnetic method. Results indicate: 1. when excited signal is transmitted from surficial source, Cagniard resistivity and phase calculated by electromagnetic components from underground receivers in the far field can reflect the abnormal body clearly. 2. when the artificial sources are located in the tunnel of well, the exploration data obtaining from receivers on the ground far field can be inversion similar to magnetetolluric data. 3. According to the observation in the tunnel or well above the abnormal body, it is easy to find the deeper objects.

Jing, J.; Jin, S.; Wei, W.; Deng, M.; Ye, G.

2010-12-01

50

Identification of School Bullies by Survey Methods  

ERIC Educational Resources Information Center

How can middle school counselors identify bullies? This study compared two methods of identifying bullies in a sample of 386 middle school students. A peer nomination survey identified many more bullies than did student self-report. Moreover, self-reported and peer nominated bullies differed in their types of bullying behaviors, level of general…

Cole, Joanna C. M.; Cornell, Dewey G.; Sheras, Peter

2006-01-01

51

Cooperative ground-water investigations in Massachusetts by the United States Geological Survey, 1938-50  

USGS Publications Warehouse

The United States Geological Survey in cooperation with the Massachusetts Department of Public Works in 1938 began an investigation of the ground-water conditions in Massachusetts. This work is part of a larger cooperative program that includes surface-water investigations, geologic studies, and topographic mapping. The purpose of the ground-water studies is to obtain detailed information concerning the occurrence and availability of ground water throughout the State. The information is used by the Highway Division of the Department of Public Works in connection with design, construction, and maintenance of highways. These studies also provided a basis for the more effective utilization of the ground-water resources of the State. They indicate where additional developments can be made safely or where present use may be excessive. Reports covering the ground-water studies are listed in the appendix.

Brashears, M.L., Jr.

1950-01-01

52

Aiming for the next bright super earth — Synergies of Ground and Space based Transiting Planets Survey  

NASA Astrophysics Data System (ADS)

With the great success of the Kepler space mission, our knowledge of Exoplanets has been dramatically extended. Nevertheless, ground based transit surveys pioneered the searching of transiting planets and developed many state-of-art techniques widely adopted by the transit community. The HATNet project is one of the most fruitful ground based transit surveys. Been operated for ~10 years, the survey yields ~50 HAT planets, constitute one fourth of the known population with accurate (<=10%) mass determinations.During the operation of Kepler Mission, HATNet team used our state-of-art pipeline and our long terms of observations in Kepler field to assist the analysis of Kepler data and the discovery of new candidates. The large sky coverage of HAT observations will provide continuous supports for the ongoing and future space based transit missions, such as K2 and TESS.On the other hand, we are able to learn about our noise characteristics and candidate selection limitations with the high precision photometric data from Kepler and our simultaneous observations.By exploiting synergies between ground based transit surveys and space transit missions, we'll be able to progress towards discover of bright super earths that are suitable for follow up spectroscopic observationsto investigate their atmosphere properties and chemical compositions. In this talk, I will first briefly review the contributions from the HATNet team in the Kepler mission. I will then present our latest effort in improving the yields and statistics of ground based transit surveys by simultaneousobservations of Kepler's field and employing machine learning techniques in our candidate selection processes. To finish up, I'll demonstrate the roles ground based transit surveys would play in the context of K2 and TESS.

Huang, Xu; Bakos, Gaspar; Hartman, Joel; HATNet Team

2015-01-01

53

Tectonic influences on ground water quality: insight from complementary methods.  

PubMed

A study using multiple techniques provided insight into tectonic influences on ground water systems; the results can help to understand ground water systems in the tectonically active western United States and other parts of the world. Ground water in the San Bernardino Valley (Arizona, United States and Sonora, Mexico) is the main source of water for domestic use, cattle ranching (the primary industry), and the preservation of threatened and endangered species. To improve the understanding of ground water occurrence, movement, and sustainability, an investigation was conducted using a number of complementary methods, including major ion geochemistry, isotope hydrology, analysis of gases dissolved in ground water, aquifer testing, geophysics, and an examination of surface and subsurface geology. By combining information from multiple lines of investigation, a more complete picture of the basin hydrogeology was assembled than would have been possible using fewer methods. The results show that the hydrogeology of the San Bernardino Valley is markedly different than that of its four neighboring basins in the United States. The differences include water quality, chemical evolution, storage, and residence time. The differences result from the locally unique geology of the San Bernardino Valley, which is due to the presence of a magmatically active accommodation zone (a zone separating two regions of normal faults with opposite dips). The geological differences and the resultant hydrological differences between the San Bernardino Valley and its neighboring basins may serve as a model for the distinctive nature of chemical evolution of ground water in other basins with locally distinct tectonic histories. PMID:18194326

Earman, Sam; McPherson, Brian J O L; Phillips, Fred M; Ralser, Steve; Herrin, James M; Broska, James

2008-01-01

54

Ground to survey aerostatic platform bidirectional free space optical link  

NASA Astrophysics Data System (ADS)

The mass and the power consumption are the most constrictive restrictions in an Aerostatic Platform. We present in this work a bidirectional link based on a liquid crystal retro-modulator (LCRM). The use of this device displaces to the terrestrial station the tasks of powering the laser, and the pointing mechanism. Also, due to the non-conductive characteristic of the LCRM, the power requirements are low. The beam aperture of the upward link can be tailored with the compromise between the aperture losses, and the tracking mechanics. The range of the distances for the system presented is from 2 to 20 km, being the lower limit for the tests and checking of the system, and the higher the final system for a stratospheric survey Aerostat. The system will be modified to fulfill the requirements associated to the increasing distances, although the main characteristics (modulation schemes, modulator, etc.) will be maintained. The system uses two modulation schemes for each direction: in the uplink a carrier constant envelope FSK modulation is used. For the down link, part of the optical signal is polarization modulated and reflected to the earth. For increasing the data rate, a multi-polarization modulation is used. Actually, 32 polarization levels are used, increasing the data rate in a 5-fold factor. The use of differential scheme, i.e. the State of Polarization (SOP) change defines the data, not the SOP, avoids the necessity of SOP maintenance in the transmitter.

López-Hernández, F. J.; Geday, M. A.; del-Campo, G.; Martin-Fuertes, D.; Carrasco-Casado, A.; Munuera, P.

2007-10-01

55

Delineation of a landfill leachate plume using shallow electromagnetic and ground-penetrating radar surveys  

SciTech Connect

Leachate plumes are often more electrically conductive than the surrounding host pore waters, and thus can be detected using shallow electromagnetic (EM) methods. The depth of penetration of ground penetrating radar (GPR) is controlled to a large extent by the electrical conductivity. Conductive leachate plumes will appear as ``blank`` areas in the radar profiles, because the radar energy is more severely attenuated in the region of the leachate plume. The authors present here the results of EM and GPR Surveys carried out in an area adjacent to a landfill site. Previous resistivity surveys indicated the presence of a leachate plume originating from an early stage of the landfill operation. The shallow EM and GPR surveys were carried out, in part, to confirm and refine the resistivity results, and to delineate the spatial extent of the plume. The surficial sediments are coastal sands, and the dune topography has an effect on the EM results, even though the variations in elevation are, in general, no more than 3 m. Besides the leachate plume, numerous conductivity highs and lows are present, which are at least coarsely correlated with topographic lows and highs. Following the empirical procedure outlined by Monier-Williams et al. (1990), the topographic effects have been removed, and the plume is better isolated and delineated. A possible second, weaker leachate plume has been identified, emanating from the current landfill operation. The second plume may follow a channel that was masked by the overlying dune sands. The leading edge of the primary leachate plume is moving to the south-southeast at a rate of 14 to 15 m/yr.

Nobes, D.C.; Armstrong, M.J. [Univ. of Canterbury, Christchurch (New Zealand); Broadbent, M. [Broadbent (Michael), Christchurch (New Zealand)

1994-12-31

56

Ground survey of active Central American volcanoes in November - December 1973  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Thermal anomalies at two volcanoes, Santiaguito and Izalco, have grown in size in the past six months, based on repeated ground survey. Thermal anomalies at Pacaya volcano have became less intense in the same period. Large (500 m diameter) thermal anomalies exist at 3 volcanoes presently, and smaller scale anomalies are found at nine other volcanoes.

Stoiber, R. E. (principal investigator); Rose, W. I., Jr.

1974-01-01

57

GPR and bulk ground resistivity surveys in graveyards: locating unmarked burials in contrasting soil types.  

PubMed

With graveyards and cemeteries globally being increasingly designated as full, there is a growing need to identify unmarked burial positions to find burial space or exhume and re-inter if necessary. In some countries, for example the U.S. and U.K., burial sites are not usually re-used; however, most graveyard and cemetery records do not have maps of positions. One non-invasive detection method is near-surface geophysics, but there has been a lack of research to-date on optimal methods and/or equipment configuration. This paper presents three case studies in contrasting burial environments, soil types, burial styles and ages in the U.K. Geophysical survey results reveal unmarked burials could be effectively identified from these case studies that were not uniform or predicted using 225 MHz frequency antennae GPR 2D 0.5 m spaced profiles. Bulk ground electrical surveys, rarely used for unmarked burials, revealed 1 m probe spacings were optimal compared to 0.5 m, with datasets needing 3D detrending to reveal burial positions. Results were variable depending upon soil type; in very coarse soils GPR was optimal; whereas resistivity was optimal in clay-rich soils and both were optimal in sandy and black earth soils. Archaeological excavations revealed unmarked burials, extra/missing individuals from parish records and a variety of burial styles from isolated, brick-lined, to vertically stacked individuals. Study results, evidence unmarked burial targets were significantly different from clandestine burials of murder victims which are used as analogues. PMID:24559798

Hansen, James D; Pringle, Jamie K; Goodwin, Jon

2014-04-01

58

A Constrained Path Monte Carlo Method for Fermion Ground States  

E-print Network

We describe and discuss a recently proposed quantum Monte Carlo algorithm to compute the ground-state properties of various systems of interacting fermions. In this method, the ground state is projected from an initial wave function by a branching random walk in an over-complete basis of Slater determinants. By constraining the determinants according to a trial wave function $|\\psi_T\\rangle$, we remove the exponential decay of signal-to-noise ratio characteristic of the sign problem. The method is variational and is exact if $|\\psi_T\\rangle$ is exact. We illustrate the method by describing in detail its implementation for the two-dimensional one-band Hubbard model. We show results for lattice sizes up to $16\\times 16$ and for various electron fillings and interaction strengths. Besides highly accurate estimates of the ground-state energy, we find that the method also yields reliable estimates of other ground-state observables, such as superconducting pairing correlation functions. We conclude by discussing possible extensions of the algorithm.

Shiwei Zhang; J. Carlson; J. E. Gubernatis

1996-07-09

59

The Constant Comparative Analysis Method Outside of Grounded Theory  

ERIC Educational Resources Information Center

This commentary addresses the gap in the literature regarding discussion of the legitimate use of Constant Comparative Analysis Method (CCA) outside of Grounded Theory. The purpose is to show the strength of using CCA to maintain the emic perspective and how theoretical frameworks can maintain the etic perspective throughout the analysis. My…

Fram, Sheila M.

2013-01-01

60

Use of AVHRR NDVI time series and ground-based surveys for estimating county-level crop biomass  

Microsoft Academic Search

Crop biomass and residue production are major components of cropland carbon dynamics that can be estimated using yield data from ground-based surveys. In the USA, surveyed yield data are available at county level and have been widely used for various research, economic and policy purposes, in addition to biomass estimation. However, survey data may be unavailable for certain times and\\/or

E. Lokupitiya; M. Lefsky; K. Paustian

2010-01-01

61

SURVEY RESEARCH LABORATORY UNIVERSITY OF ILLINOIS AT CHICAGO Conference on Health Survey Research Methods  

E-print Network

from various disciplines who are at the forefront of survey methods research, who are responsible research that advances the field beyond what is currently known about survey methods and their application

Illinois at Chicago, University of

62

Comparison of Creel Survey Methods on Missouri River Reservoirs  

E-print Network

Comparison of Creel Survey Methods on Missouri River Reservoirs CRAIG A. SOUPIR*1 South Dakota Game and Parks, Fort Pierre, South Dakota 57532, USA Abstract.--When creel survey methods such as noncontact indicated breakpoints in variance estimates between six and seven counts for both survey methods. Therefore

63

MODFLOW-2005 : the U.S. Geological Survey modular ground-water model--the ground-water flow process  

USGS Publications Warehouse

This report presents MODFLOW-2005, which is a new version of the finite-difference ground-water model commonly called MODFLOW. Ground-water flow is simulated using a block-centered finite-difference approach. Layers can be simulated as confined or unconfined. Flow associated with external stresses, such as wells, areal recharge, evapotranspiration, drains, and rivers, also can be simulated. The report includes detailed explanations of physical and mathematical concepts on which the model is based, an explanation of how those concepts are incorporated in the modular structure of the computer program, instructions for using the model, and details of the computer code. The modular structure consists of a MAIN Program and a series of highly independent subroutines. The subroutines are grouped into 'packages.' Each package deals with a specific feature of the hydrologic system that is to be simulated, such as flow from rivers or flow into drains, or with a specific method of solving the set of simultaneous equations resulting from the finite-difference method. Several solution methods are incorporated, including the Preconditioned Conjugate-Gradient method. The division of the program into packages permits the user to examine specific hydrologic features of the model independently. This also facilitates development of additional capabilities because new packages can be added to the program without modifying the existing packages. The input and output systems of the computer program also are designed to permit maximum flexibility. The program is designed to allow other capabilities, such as transport and optimization, to be incorporated, but this report is limited to describing the ground-water flow capability. The program is written in Fortran 90 and will run without modification on most computers that have a Fortran 90 compiler.

Harbaugh, Arlen W.

2005-01-01

64

Status of aerial survey emergency preparedness and ground support equipment, calibration, and sensitivities  

SciTech Connect

During the course of EG and G Energy Measurements, Inc. history in aerial surveillance, the scope of response has broadened from routine surveys and accident response with aerial systems, to being prepared to respond to any radiological incident with aerial, ground mobile, and hand-held instrumentation. The aerial survey system presently consists of four MBB BO-105 helicopters outfitted with gamma pods and specialized navigation systems (MRS or URS) that allow the operator and pilot to fly well-defined survey lines. Minimum detectable activities (MDA) for various isotopes range from a few tenths of a mCi to 100 mCI for point sources and from 1 to 200 pCi/g for volume sources.

Dahlstrom, T.S.

1986-01-01

65

Development of Grounded Electrical Source Airborne Transient EM (GREATEM) Survey System and Its Application to Investigating a Volcano Structure  

NASA Astrophysics Data System (ADS)

We have developed an airborne EM system that uses a grounded electrical source and an airborne magnetic field receiver to increase the depth of investigation. Using a grounded source, we can apply a large source moment with a long transmitter-receiver distance, thus we expect to obtain a greater depth of investigation. However, the area of survey is limited with this type of method, but it has some advantages such as little effect of flight level etc. We believe that a repeated survey in active area such as volcano or fault area is effective for monitoring activity in the whole area. By using the airborne survey, we will be able to make repeated survey rapidly in volcano area where it is difficult to enter by a ground survey. The initial stage of the development was reported at Mogi et al. (1998) and the survey system was named as GREATEM (Grounded electrical source airborne transient EM). Time domain data acquisition has an advantage to the deep exploration because it avoids near source field effects that occur in frequency domain measurements. To realize the method, we should overcome mainly two problems: monitoring and filtering the motion noise of the receiver and canceling the natural magnetic field variation and cultural noise without stacking in the time domain data. We prepared high accuracy fiber optic gyros to monitor the pitch and roll of the magnetic sensor in the bird to monitor the motion and also manufactured an electromagnetic receiver that can detect three components of magnetic field and a tilt meter with MI sensor which can detect up to_ 100,000 nT with a sensitivity of 0.04 mV/nT. These receiver and tilt meter are installed on a gimbal in a bird. Data acquisition system is installed in the helicopter cabin with high precision GPS synchronized with the same type GPS set in the transmitter. In this system, we designed to analyze full wave data in time-domain for investigating deep to shallow underground resistivity structure. The measured data of three-component magnetic filed, tilting, time and positioning are digitized at 25 kHz for 10 channels. We have also developed a 3D modeling scheme to investigate magnetic field responses in the air for complicated subsurface structure and topography. We carried out GREATEM surveys at Aso Volcano, southwest Japan to test the survey system and clarify the subsurface structure of the volcano. We computed the transient response of the magnetic field in the air by removing motion noise and other EM noise using special digital filters. Finally we obtained resistivity structure, assuming horizontal layer structure. The depth of investigation of present survey was estimated about 800m deep.

Mogi, T.; Jomori, A.; Jomori, N.; Azuma, Y.; Fomenko, E. Y.

2005-12-01

66

Geological and seismological survey for new design-basis earthquake ground motion of Kashiwazaki-Kariwa NPS  

NASA Astrophysics Data System (ADS)

At about 10:13 on July 16, 2007, a strong earthquake named 'Niigata-ken Chuetsu-oki Earthquake' of Mj6.8 on Japan Meteorological Agencyfs scale occurred offshore Niigata prefecture in Japan. However, all of the nuclear reactors at Kashiwazaki-Kariwa Nuclear Power Station (KKNPS) in Niigata prefecture operated by Tokyo Electric Power Company shut down safely. In other words, automatic safety function composed of shutdown, cooling and containment worked as designed immediately after the earthquake. During the earthquake, the peak acceleration of the ground motion exceeded the design-basis ground motion (DBGM), but the force due to the earthquake applied to safety-significant facilities was about the same as or less than the design basis taken into account as static seismic force. In order to assess anew the safety of nuclear power plants, we have evaluated a new DBGM after conducting geomorphological, geological, geophysical, seismological survey and analyses. [Geomorphological, Geological and Geophysical survey] In the land area, aerial photograph interpretation was performed at least within the 30km radius to extract geographies that could possibly be tectonic reliefs as a geomorphological survey. After that, geological reconnaissance was conducted to confirm whether the extracted landforms are tectonic reliefs or not. Especially we carefully investigated Nagaoka Plain Western Boundary Fault Zone (NPWBFZ), which consists of Kakuda-Yahiko fault, Kihinomiya fault and Katakai fault, because NPWBFZ is the one of the active faults which have potential of Mj8 class in Japan. In addition to the geological survey, seismic reflection prospecting of approximate 120km in total length was completed to evaluate the geological structure of the faults and to assess the consecutiveness of the component faults of NPWBFZ. As a result of geomorphological, geological and geophysical surveys, we evaluated that the three component faults of NPWBFZ are independent to each other from the viewpoint of geological structure, however we have decided to take into consideration simultaneous movement of the three faults which is 91km long in seismic design as a case of uncertainty. In the sea area, we conducted seismic reflection prospecting with sonic wave in the area stretching for about 140km along the coastline and 50km in the direction of perpendicular to the coastline. When we analyze the seismic profiles, we evaluated the activities of faults and foldings carefully on the basis of the way of thinking of 'fault-related-fault' because the sedimentary layers in the offing of Niigata prefecture are very thick and the geological structures are characterized by foldings. As a result of the seismic reflection survey and analyses, we assess that five active faults (foldings) to be taken into consideration to seismic design in the sea area and we evaluated that the F-B fault of 36km will have the largest impact on the KKNPS. [Seismological survey] As a result of analyses of the geological survey, data from NCOE and data from 2004 Chuetsu Earthquake, it became clear that there are factors that intensifies seismic motions in this area. For each of the two selected earthquake sources, namely NPWBFZ and F-B fault, we calculated seismic ground motions on the free surface of the base stratum as the design-basis ground motion (DBGM) Ss, using both empirical and numerical ground motion evaluation method. PGA value of DBGM is 2,300Gal for unit 1 to 4 located in the southern part of the KKNPS and 1,050Gal for unit 5 to 7 in the northern part of the site.

Takao, M.; Mizutani, H.

2009-05-01

67

A study of the geoelectrical properties of peatlands and their influence on ground-penetrating radar surveying  

SciTech Connect

A variety of geophysical methods have been used on peatlands, including ground penetrating radar (GPR), resistivity, and electromagnetic induction (EM) surveying. The full potential of these techniques remains largely unexplored, mainly because the understanding of the physical factors that control the instrument response in peatlands is incomplete. The water table is normally at, or slightly below, the ground surface; the peat thickness can range from 40 cm to 10 m. In bulk, peat is mostly water, with a supporting matrix made of purely organic materials. The organic materials are the partially decomposed remains of plants, which can take millennia to accumulate in the form of peat. Internal stratigraphic features and thicknesses of peatlands can vary dramatically with little predictability on the basis of surface vegetation. The authors discuss the use of geophysics, alone and as a supplement to conventional coring programs. They have investigated three peatland sites, and have carried out comparisons of the electrical property variations and of the heat physical properties that may be detected by geophysical methods, from site to site and within individual peatlands. They also suggest a systematic protocol for the geophysical investigation of peatlands, specifically, and for GPR surveys generally.

Theimer, B.D. (Piteau Engineering, Vancouver, British Columbia (Canada)); Nobes, D.C. (Univ. of Canterbury, Christchurch (New Zealand). Dept. of Geology); Warner, B.G. (Univ. of Waterloo, Ontario (Canada))

1994-04-01

68

A ground moving target emergency tracking method for catastrophe rescue  

NASA Astrophysics Data System (ADS)

In recent years, great disasters happen now and then. Disaster management test the emergency operation ability of the government and society all over the world. Immediately after the occurrence of a great disaster (e.g., earthquake), a massive nationwide rescue and relief operation need to be kicked off instantly. In order to improve the organizations efficiency of the emergency rescue, the organizers need to take charge of the information of the rescuer teams, including the real time location, the equipment with the team, the technical skills of the rescuers, and so on. One of the key factors for the success of emergency operations is the real time location of the rescuers dynamically. Real time tracking methods are used to track the professional rescuer teams now. But volunteers' participation play more and more important roles in great disasters. However, real time tracking of the volunteers will cause many problems, e.g., privacy leakage, expensive data consumption, etc. These problems may reduce the enthusiasm of volunteers' participation for catastrophe rescue. In fact, the great disaster is just small probability event, it is not necessary to track the volunteers (even rescuer teams) every time every day. In order to solve this problem, a ground moving target emergency tracking method for catastrophe rescue is presented in this paper. In this method, the handheld devices using GPS technology to provide the location of the users, e.g., smart phone, is used as the positioning equipment; an emergency tracking information database including the ID of the ground moving target (including the rescuer teams and volunteers), the communication number of the handheld devices with the moving target, and the usually living region, etc., is built in advance by registration; when catastrophe happens, the ground moving targets that living close to the disaster area will be filtered by the usually living region; then the activation short message will be sent to the selected ground moving target through the communication number of the handheld devices. The handheld devices receive and identify the activation short message, and send the current location information to the server. Therefore, the emergency tracking mode is triggered. The real time location of the filtered target can be shown on the organizer's screen, and the organizer can assign the rescue tasks to the rescuer teams and volunteers based on their real time location. The ground moving target emergency tracking prototype system is implemented using Oracle 11g, Visual Studio 2010 C#, Android, SMS Modem, and Google Maps API.

Zhou, X.; Li, D.; Li, G.

2014-11-01

69

COMPARISON OF DETECTION PROBABILITY ASSOCIATED WITH BURROWING OWL SURVEY METHODS  

E-print Network

COMPARISON OF DETECTION PROBABILITY ASSOCIATED WITH BURROWING OWL SURVEY METHODS COURTNEY J. CONWAY, grassland, monitoring, popula- tion declines, survey methods, tape playback, Wyoming. 501 Populations program is not available to quantify changes in abun- dance or distribution. Before a standardized survey

Conway, Courtney J.

70

Aerial surveys adjusted by ground surveys to estimate area occupied by black-tailed prairie dog colonies  

Technology Transfer Automated Retrieval System (TEKTRAN)

State and federal agencies use estimates of the area of black-tailed prairie dog (BTPD) colonies in North America as a metric to assess the status of the species. Aerial surveys using line-intercept methods are one approach to estimate the extent of BTPD colonies in a large geographic area such as a...

71

Modified Universal Design Survey: Enhancing Operability of Launch Vehicle Ground Crew Worksites  

NASA Technical Reports Server (NTRS)

Operability is a driving requirement for next generation space launch vehicles. Launch site ground operations include numerous operator tasks to prepare the vehicle for launch or to perform preflight maintenance. Ensuring that components requiring operator interaction at the launch site are designed for optimal human use is a high priority for operability. To promote operability, a Design Quality Evaluation Survey based on Universal Design framework was developed to support Human Factors Engineering (HFE) evaluation for NASA s launch vehicles. Universal Design per se is not a priority for launch vehicle processing however; applying principles of Universal Design will increase the probability of an error free and efficient design which promotes operability. The Design Quality Evaluation Survey incorporates and tailors the seven Universal Design Principles and adds new measures for Safety and Efficiency. Adapting an approach proven to measure Universal Design Performance in Product, each principle is associated with multiple performance measures which are rated with the degree to which the statement is true. The Design Quality Evaluation Survey was employed for several launch vehicle ground processing worksite analyses. The tool was found to be most useful for comparative judgments as opposed to an assessment of a single design option. It provided a useful piece of additional data when assessing possible operator interfaces or worksites for operability.

Blume, Jennifer L.

2010-01-01

72

Development of Grounded Electrical Source Airborne Transient EM (GREATEM) Survey System and Its Application to Investigating a Volcano Structure  

Microsoft Academic Search

We have developed an airborne EM system that uses a grounded electrical source and an airborne magnetic field receiver to increase the depth of investigation. Using a grounded source, we can apply a large source moment with a long transmitter-receiver distance, thus we expect to obtain a greater depth of investigation. However, the area of survey is limited with this

T. Mogi; A. Jomori; N. Jomori; Y. Azuma; E. Y. Fomenko

2005-01-01

73

Buoyancy Distribution Around Ice Sheet Grounding Zones in the Western Amundsen Sea Embayment, Antarctica: Results from the AGASEA Survey  

Microsoft Academic Search

Exposed grounding lines abutting Antarctica's relatively warm Amundsen Sea may represent an important locus of ice sheet erosion. Recent satellite remote sensing has indicated both expansion and retreat of active grounding lines in the region, with implications for global sea level change. As part of the 2004\\/05 AGASEA project, the University of Texas Institute for Geophysics (UTIG) surveyed Thwaites Glacier

D. A. Young; D. D. Blankenship; D. G. Vaughan; J. W. Holt

2005-01-01

74

Discontinuous Galerkin Finite Element Method: Survey and Recent Development  

E-print Network

Discontinuous Galerkin Finite Element Method: Survey and Recent Development Chi-Wang Shu Division of the discontinuous Galerkin (DG) method · DG method based on non-polynomial approximation spaces Division of Applied Mathematics, Brown University #12;DISCONTINUOUS GALERKIN FINITE ELEMENT METHOD: SURVEY AND RECENT DEVELOPMENT

Kurganov, Alexander

75

Improved pipe-to-soil potential survey methods  

SciTech Connect

In 1988, the Corrosion Supervisory Committee of the Pipeline Research Committee initiated PR-186-807 titled Improved Pipe-to-Soil Potential Survey Methods.'' The primary purpose of PR-186-807 was to establish the portion of pipe sampled during a ground level pipe-to-soil potential measurement. The overall objective of this program was to improve the ability to perform and interpret close interval on- and off-potential surveys. This program included both large-scale field experiments utilizing 290 feet of 24 and 20-inch diameter pipe ranging from bare to well coated. The field measurements were primarily utilized to verify finite element analysis modeling. The modeling effort was performed to provide general statements on the area of pipe sampled as opposed to the very specific conditions present in the field measurements. This project was performed over a three year period from 1988 through 1990. The first two years examined bare pipe conditions and the third year examined coated pipe conditions. In the following sections, the results for the bare pipe and the coated pipe portions of this project are presented under separate headings.

Thompson, N.G.; Lawson, K.M.

1991-04-30

76

Assessment of some important factors affecting the singing-ground survey  

USGS Publications Warehouse

A brief history of the procedures used to analyze singing-ground survey data is outlined. Some weaknesses associated with the analytical procedures are discussed, and preliminary results of efforts to improve the procedures are presented. The most significant finding to date is that counts made by new observers need not be omitted when calculating an index of the woodcock population. Also, the distribution of woodcock heard singing, with respect to time after sunset, affirms the appropriateness of recommended starting times for counting woodcock. Woodcock count data fit the negative binomial probability distribution.

Tautin, J.

1982-01-01

77

Signature of hydrothermal alteration in ground-magnetic surveys at Yellowstone National Park  

NASA Astrophysics Data System (ADS)

Yellowstone National Park (YNP) hosts a very large hydrothermal system with over 10,000 thermal features. Although hydrothermal alteration in YNP has been extensively studied with field observations, remote-sensing imagery, and core drilling, the volume and geometry of hydrothermal systems at depth remain poorly constrained. Magnetic surveys can help to investigate buried hydrothermal alteration as demonstrated by the high-resolution aeromagnetic survey of YNP (Finn and Morgan, J. Volcanol. Geotherm. Res., 115, 207-231, 2002). Results of this survey show that magnetic lows extend over and beyond areas of hydrothermal activity. This suggests large volumes of buried demagnetized rocks due to hydrothermal alteration of the volcanic substratum. Although the interpretation of magnetic anomalies is non-unique, Finn and Morgan (2002) used these magnetic lows to estimate a minimum volume of buried altered rock assuming complete demagnetization of the substratum. This aeromagnetic survey was of relatively high resolution (flight line spacing < 500 m and flight elevation <350 m above ground), but it was insufficient for detailed mapping of individual thermal areas. In order to obtain a closer look at several areas, we performed ground-based magnetic surveys within YNP using a cesium-vapor magnetometer along 4-5 km long transects crossing four thermal areas (Norris Geyser Basin, Lower Geyser Basin, Lone Star Geyser Basin, and Smoke Jumper Hot-springs). We also performed a detailed survey over an area of about 800 m x 500 m around Lone Star Geyser. We also collected gravity data to help characterize the subsurface geologic structures and performed magnetic susceptibility, magnetic remanence, and density measurements on rock samples collected in the field and from drill cores collected in 1967-1968 to characterize physical properties of fresh and altered geologic units. The long magnetic transects show that magnetic anomalies are damped in altered areas suggesting a significant decrease in the magnetization of shallow volcanic units. The detailed magnetic map of the Lone Star Geyser displays a pronounced negative anomaly centered on the geyser mound and other hot-springs indicating demagnetization directly associated with the hydrothermal plumbing system. These surveys will be used to model the geometry of the demagnetized volcanic substratum associated with hydrothermal alteration.

Bouligand, C.; Glen, J. M.; McPhee, D. K.

2011-12-01

78

Multidisciplinary eHealth Survey Evaluation Methods  

ERIC Educational Resources Information Center

This paper describes the development process of an evaluation framework for describing and comparing web survey tools. We believe that this approach will help shape the design, development, deployment, and evaluation of population-based health interventions. A conceptual framework for describing and evaluating web survey systems will enable the…

Karras, Bryant T.; Tufano, James T.

2006-01-01

79

Airborne Gravity Survey and Ground Gravity in Afghanistan: A Website for Distribution of Data  

USGS Publications Warehouse

Afghanistan?s geologic setting suggests significant natural resource potential. Although important mineral deposits and petroleum resources have been identified, much of the country?s potential remains unknown. Airborne geophysical surveys are a well- accepted and cost-effective method for remotely obtaining information of the geological setting of an area. A regional airborne geophysical survey was proposed due to the security situation and the large areas of Afghanistan that have not been covered using geophysical exploration methods. Acting upon the request of the Islamic Republic of Afghanistan Ministry of Mines, the U.S. Geological Survey contracted with the U.S. Naval Research Laboratory to jointly conduct an airborne geophysical and remote sensing survey of Afghanistan. Data collected during this survey will provide basic information for mineral and petroleum exploration studies that are important for the economic development of Afghanistan. Additionally, use of these data is broadly applicable in the assessment of water resources and natural hazards, the inventory and planning of civil infrastructure and agricultural resources, and the construction of detailed maps. The U.S. Geological Survey is currently working in cooperation with the U.S. Agency of International Development to conduct resource assessments of the country of Afghanistan for mineral, energy, coal, and water resources, and to assess geologic hazards. These geophysical and remote sensing data will be used directly in the resource and hazard assessments.

Abraham, Jared D.; Anderson, Eric D.; Drenth, Benjamin J.; Finn, Carol A.; Kucks, Robert P.; Lindsay, Charles R.; Phillips, Jeffrey D.; Sweeney, Ronald E.

2008-01-01

80

An analysis of two ground truth estimation methods  

NASA Astrophysics Data System (ADS)

An estimation of the so called Ground Truth (GT), i.e. the actual lesion region, can minimize readers' subjectivity if multiple readers' markings are combined. Two methods perform this estimate by considering the spatial location of voxels: Thresholded Probability-Map (TPM) and Simultaneous Truth and Performance Level Estimation (STAPLE). An analysis of these two methods has already been performed. The purpose of this study, however, is gaining a new insight into the method outcomes by comparing the estimated regions. A subset of the publicly available Lung Image Database Consortium archive was used, selecting pulmonary nodules documented by all four radiologists. The TPM estimator was computed by assigning to each voxel a value equal to average number of readers that included such voxel in their markings and then applying a threshold of 0.5. Our STAPLE implementation is loosely based on a version from ITK, to which we added the graph cut post-processing. The pair-wise similarities between the estimated ground truths were analyzed by computing the respective Jaccard coefficients. Then, the sign test of the differences between the volumes of TPM and STAPLE was performed. A total of 35 nodules documented on 26 scans by all four radiologists were available. The spatial agreement had a one-sided 90% Confidence Interval of [0.92, 1.00]. The sign test of the differences had a p-value less than 0.001. We found that (a) the differences in their volume estimates are statistically significant, (b) the spatial disagreement between the two estimators is almost completely due to the exclusion of voxels marked by exactly two readers, (c) STAPLE tends to weight more, in its GT estimate, readers marking broader regions.

Biancardi, A. M.; Jirapatnakul, A. C.; Fotin, S.; Apanasovich, T.; Reeves, A. P.

2009-02-01

81

Application of ground-penetrating-radar methods in hydrogeologic studies  

USGS Publications Warehouse

A ground-penetrating-radar system was used to study selected stratified-drift deposits in Connecticut. Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. Traverse locations on land included a well field in the town of Mansfield, a sand and gravel pit and a farm overlying a potential aquifer in the town of Coventry, and Haddam Meadows State Park in the town of Haddam. Traverse locations on water included the Willimantic River in Coventry and Mansfield Hollow Lake in Mansfield. The penetration depth of the radar signal ranged from about 20 feet in fine-grained glaciolacustrine sediments to about 70 feet in coarse sand and gravel. Some land records in coarse-grained sediments show a distinct, continuous reflection from the water table about 5 to 11 feet below land surface. Parallel reflectors on the records are interpreted as fine-grained sediments. Hummocky or chaotic reflectors are interpreted as cross-bedded or coarse-grained sediments. Other features observed on some of the radar records include the till and bedrock surface. Records collected on water had distinct water-bottom multiples (more than one reflection) and diffraction patterns from boulders. The interpretation of the radar records, which required little or no processing, was verified by using lithologic logs from test holes located along some of the land traverses and near the water traverses.

Beres, Milan, Jr.; Haeni, F.P.

1991-01-01

82

Ground penetrating radar surveys to locate 1918 Spanish flu victims in permafrost.  

PubMed

The "Spanish Flu" killed over 40 million people worldwide in 1918. Archival records helped us identify seven men who died of influenza in 1918 and were interred in Longyearbyen, Svalbard, Norway, 1,300 km from the North Pole. Ground Penetrating Radar (GPR) was used successfully, in a high-resolution field survey mode, to locate a large excavation with seven coffins, near the existing seven grave markers. The GPR indicated that the ground was disturbed to 2 m depth and was frozen below 1 m. Subsequent excavation showed that: a) the GPR located the position of the graves accurately, b) the coffins were buried less than 1 m deep, and c) that the frozen ground was 1.2 m deep where the coffins were located. The GPR assisted in planning the exhumation, safely and economically, under the high degree of containment required. Virologic and bacteriologic investigations on recovered tissues may give us an opportunity to isolate and identify the micro-organisms involved in the 1918 influenza and expand our knowledge on the pathogenesis of influenza. PMID:10641921

Davis, J L; Heginbottom, J A; Annan, A P; Daniels, R S; Berdal, B P; Bergan, T; Duncan, K E; Lewin, P K; Oxford, J S; Roberts, N; Skehel, J J; Smith, C R

2000-01-01

83

Method and apparatus for injecting particulate media into the ground  

DOEpatents

An improved method and apparatus for injecting particulate media into the ground for constructing underground permeable reactive barriers, which are used for environmental remediation of subsurface contaminated soil and water. A media injector sub-assembly attached to a triple wall drill string pipe sprays a mixture of active particulate media suspended in a carrier fluid radially outwards from the sub-assembly, at the same time that a mixing fluid is sprayed radially outwards. The media spray intersects the mixing spray at a relatively close distance from the point of injection, which entrains the particulate media into the mixing spray and ensures a uniform and deep dispersion of the active media in the surrounding soil. The media injector sub-assembly can optionally include channels for supplying compressed air to an attached down-the-hole hammer drive assembly for use during drilling.

Dwyer, Brian P.; Dwyer, Stephen F.; Vigil, Francine S.; Stewart, Willis E.

2004-12-28

84

Summary of selected computer programs produced by the U.S. Geological Survey for simulation of ground-water flow and quality, 1994  

USGS Publications Warehouse

A summary list of reports that document numerical methods that simulate ground-water flow and quality is presented. The list documents the reference by giving a description of each model program, its numerical features, an expression of the number of past applications and where to obtain a copy. All reports included in the list have been published or developed by the U.S. Geological Survey and most contain listings of the computer programs.

Appel, Charles A.; Reilly, Thomas E.

1994-01-01

85

Combination of corrosion-survey methods improves protection  

SciTech Connect

Combining the three most widely used aboveground-survey procedures for evaluating coating integrity and cathodic protection adequacy can overcome the technical and economic penalties of choosing a single survey method. A review of each method and of several case histories shows how the procedures complement each other.

Allen, M.D.; Barnes, N.R.

1988-02-29

86

A method to search for strong galaxy-galaxy lenses in optical imaging surveys  

E-print Network

We present a semi-automated method to search for strong galaxy-galaxy lenses in optical imaging surveys. Our search technique constrains the shape of strongly lensed galaxies (or arcs) in a multi-parameter space, which includes the third order (octopole) moments of objects. This method is applied to the Deep Lens Survey (DLS), a deep ground based weak lensing survey imaging to $R\\sim26$. The parameter space of arcs in the DLS is simulated using real galaxies extracted from deep HST fields in order to more accurately reproduce the properties of arcs. Arcs are detected in the DLS using a pixel thresholding method and candidate arcs are selected within this multi-parameter space. Examples of strong galaxy-galaxy lens candidates discovered in the DLS F2 field (4 square degrees) are presented.

Jeffrey M. Kubo; Ian P. Dell'Antonio

2007-12-19

87

The effectiveness of ground-penetrating radar surveys in the location of unmarked burial sites in modern cemeteries  

NASA Astrophysics Data System (ADS)

Ground-penetration radar (GPR) is a geophysical method that is commonly used in archaeological and forensic investigations, including the determination of the exact location of graves. Whilst the method is rapid and does not involve disturbance of the graves, the interpretation of GPR profiles is nevertheless difficult and often leads to incorrect results. Incorrect identifications could hinder criminal investigations and complicate burials in cemeteries that have no information on the location of previously existing graves. In order to increase the number of unmarked graves that are identified, the GPR results need to be verified by comparing them with the soil and vegetation properties of the sites examined. We used a modern cemetery to assess the results obtained with GPR which we then compared with previously obtained tachymetric data and with an excavation of the graves where doubt existed. Certain soil conditions tended to make the application of GPR difficult on occasions, but a rough estimation of the location of the graves was always possible. The two different methods, GPR survey and tachymetry, both proved suitable for correctly determining the exact location of the majority of graves. The present study thus shows that GPR is a reliable method for determining the exact location of unmarked graves in modern cemeteries. However, the method did not allow statements to be made on the stage of decay of the bodies. Such information would assist in deciding what should be done with graves where ineffective degradation creates a problem for reusing graves following the standard resting time of 25 years.

Fiedler, Sabine; Illich, Bernhard; Berger, Jochen; Graw, Matthias

2009-07-01

88

Statistical Methods in Surveying by Trilateration  

E-print Network

-likelihood, Monte-Carlo simulation, Trilateration, Computerized surveying, Global Positioning System (GPS) 1 #12 the implementation of fully automated real-time positioning systems similar to the global positioning system (GPS, the Global Positioning System (GPS) (Leick, 1990 Parkinson and Spilker, 1996). However, TBCC determined

Hereman, Willy A.M.

89

NCES Handbook of Survey Methods: Technical Report.  

ERIC Educational Resources Information Center

This handbook presents current explanations of how each survey program of the National Center for Education Statistics (NCES) obtains and prepared the data it publishes. The handbook aims to provide users of NCES data with the most current information necessary to evaluate the suitability of the statistics for their needs, with a focus on the…

Thurgood, Lori; Walter, Elizabeth; Carter, George; Henn, Susan; Huang, Gary; Nooter, Daniel; Smith, Wray; Cash, R. William; Salvucci, Sameena; Seastrom, Marilyn; Phan, Tai; Cohen, Michael

90

Ecological survey of M-Field, Edgewood Area Aberdeen Proving Ground, Maryland  

SciTech Connect

An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army's Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

Downs, J.L.; Eberhardt, L.E.; Fitzner, R.E.; Rogers, L.E.

1991-12-01

91

Ecological survey of M-Field, Edgewood Area Aberdeen Proving Ground, Maryland  

SciTech Connect

An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army`s Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

Downs, J.L.; Eberhardt, L.E.; Fitzner, R.E.; Rogers, L.E.

1991-12-01

92

Preprint of the paper "Application of Meshless Methods to the Analysis and Design of Grounding  

E-print Network

Preprint of the paper "Application of Meshless Methods to the Analysis and Design of Grounding and Applications" (CD-ROM), Parte I: "Mathematical Modelling and Numerical Methods", Sección 6: "Meshless Methods CIMNE, Barcelona, Spain 1998 APPLICATION OF MESHLESS METHODS TO THE ANALYSIS AND DESIGN OF GROUNDING

Colominas, Ignasi

93

In-situ high-resolution gamma-spectrometric survey of burial ground-monitoring wells  

SciTech Connect

In situ high resolution gamma-ray spectrometry with an intrinsic germanium detector assembly of special design surveyed the burial ground monitoring wells to locate and identify gamma emitters that may have migrated from the burial trenches toward the water table. Gamma-ray spectra were acquired as a function of depth in each well and recorded on magnetic tape. These spectra were reduced by a series of computer programs to produce count rate versus depth profiles for natural and man-made activities. The original spectra and the profiles have been archived on magnetic tape for comparison with similar future surveys. Large amounts of man-made activities were observed in some of the burial trenches; however, below the trench bottoms, only very low but detectable amounts of /sup 60/Co and /sup 137/Cs were observed in eleven wells. The highest level of man-made gamma activity observed below the trench bottoms has a count rate roughly equal to that observed for uranium daughter activities which are natural to the subsoil.

Bowman, W.W.

1981-09-01

94

Remaining consistent with method? An analysis of grounded theory research in accounting  

Microsoft Academic Search

Purpose – The paper revisits the intellectual roots of grounded theory and aims to analyze the consistency of the method used in grounded theory research in accounting. About 23 papers are identified and analysed. Design\\/methodology\\/approach – The paper is an analytical review of the research literature. It uses four fundamental canons of grounded theory to analyze accounting research. Findings –

Bruce Gurd

2008-01-01

95

Method for Ground-to-Space Laser Calibration System  

NASA Technical Reports Server (NTRS)

The present invention comprises an approach for calibrating the sensitivity to polarization, optics degradation, spectral and stray light response functions of instruments on orbit. The concept is based on using an accurate ground-based laser system, Ground-to-Space Laser Calibration (GSLC), transmitting laser light to instrument on orbit during nighttime substantially clear-sky conditions. To minimize atmospheric contribution to the calibration uncertainty the calibration cycles should be performed in short time intervals, and all required measurements are designed to be relative. The calibration cycles involve ground operations with laser beam polarization and wavelength changes.

Lukashin, Constantine (Inventor); Wielicki, Bruce A. (Inventor)

2014-01-01

96

A Survey of Methods for Planning and Analyzing Accelerated Tests  

Microsoft Academic Search

This paper surveys methods for planning and analyzing accelerated life tests. Many of these methods are new and providemore informative results for less time and cost than do previous methods. These methods are of value to all who plan and analyze accelerated tests on any product or material.

Wayne Nelson

1974-01-01

97

A simple kriging method incorporating multiscale measurements in geochemical survey  

E-print Network

A simple kriging method incorporating multiscale measurements in geochemical survey Changjiang Li a kriging Multiresolution data Geochemical survey In this study, we propose a kriging algorithm, multiscale that there are a number of measurements at different scales, and that the target scale at which the parameter values

Lu, Zhiming

98

Methods for the survey and genetic analysis of populations  

DOEpatents

The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

Ashby, Matthew

2003-09-02

99

A study of methods for lowering aerial environmental survey cost  

NASA Technical Reports Server (NTRS)

The results are presented of a study of methods for lowering the cost of environmental aerial surveys. A wide range of low cost techniques were investigated for possible application to current pressing urban and rural problems. The objective of the study is to establish a definition of the technical problems associated with conducting aerial surveys using various low cost techniques, to conduct a survey of equipment which may be used in low cost systems, and to establish preliminary estimates of cost. A set of candidate systems were selected and described for the environmental survey tasks.

Stansberry, J. R.

1973-01-01

100

Apparatus and method for grounding compressed fuel fueling operator  

DOEpatents

A safety system for grounding an operator at a fueling station prior to removing a fuel fill nozzle from a fuel tank upon completion of a fuel filling operation is provided which includes a fuel tank port in communication with the fuel tank for receiving and retaining the nozzle during the fuel filling operation and a grounding device adjacent to the fuel tank port which includes a grounding switch having a contact member that receives physical contact by the operator and where physical contact of the contact member activates the grounding switch. A releasable interlock is included that provides a lock position wherein the nozzle is locked into the port upon insertion of the nozzle into the port and a release position wherein the nozzle is releasable from the port upon completion of the fuel filling operation and after physical contact of the contact member is accomplished.

Cohen, Joseph Perry (Bethlehem, PA); Farese, David John (Riegelsville, PA); Xu, Jianguo (Wrightstown, PA)

2002-06-11

101

A quality-assurance plan for district ground-water activities of the U.S. Geological Survey  

USGS Publications Warehouse

As the Nation's principal earth-science information agency, the U.S. Geological Survey (USGS) is depended upon to collect data of the highest quality. This document provides the framework for collecting, analyzing and reporting ground-water data that are quality assured and quality controlled.

Brunett, J.O.; Barber, N.L.; Burns, A.W.; Fogelman, R.P.; Gillies, D.C.; Lidwin, R.A.; Mack, T.J.

1997-01-01

102

Cross-cultural issues in space operations: A survey study among ground personnel of the European Space Agency  

Microsoft Academic Search

Today's space operations involve co-working of people with different ethnical, professional and organisational backgrounds. The aim of this study was to examine the implications of cultural diversity for efficient collaboration within the European Space Agency (ESA), and between ESA employees and representatives from other agencies. ESA employees from European countries (N=576) answered to the CULT Ground Survey. The results showed

Gro Mjeldheim Sandal; Dietrich Manzey

2009-01-01

103

Geological disaster survey based on Curvelet transform with borehole Ground Penetrating Radar in Tonglushan old mine site  

Microsoft Academic Search

Tonglushan old mine site located in Huangshi City, China, is very famous in the world. However, some of the ruins had suffered from geological disasters such as local deformation, surface cracking, in recent years. Structural abnormalities of rock-mass in deep underground were surveyed with borehole ground penetrating radar (GPR) to find out whether there were any mined galleries or mined-out

Xinjian Tang; Tao Sun; Zhijie Tang; Zenghui Zhou; Baoming Wei

2011-01-01

104

Field studies of the GPR ground wave method for estimating soil water content during irrigation and drainage  

Microsoft Academic Search

Knowledge of ground wave penetration depth and methods for facilitating ground wave velocity analysis are important practical aspects to consider when measuring soil water content with surface ground penetrating radar. A field study was conducted to optimize the wide angle reflection and refraction and fixed offset methods of measuring the ground wave velocity and to find the effective ground wave

L. W. Galagedara; G. W. Parkin; J. D. Redman; P. von Bertoldi; A. L. Endres

2005-01-01

105

The US Motor Systems Market Assessment: Baseline and Survey Methods  

E-print Network

THE US MOTOR SYSTEMS MARKET ASSESSMENT: BASELINE AND SURVEY METHODS Mitchell Rosenberg XENERGY Inc. Burlington, Massachusetts ABSTRACT This paper summarizes the current status of the US Motor Systems Market Assessment. This component...THE US MOTOR SYSTEMS MARKET ASSESSMENT: BASELINE AND SURVEY METHODS Mitchell Rosenberg XENERGY Inc. Burlington, Massachusetts ABSTRACT This paper summarizes the current status of the US Motor Systems Market Assessment. This component...

Rosenberg, M.

106

Verifying a computational method for predicting extreme ground motion  

USGS Publications Warehouse

In situations where seismological data is rare or nonexistent, computer simulations may be used to predict ground motions caused by future earthquakes. This is particularly practical in the case of extreme ground motions, where engineers of special buildings may need to design for an event that has not been historically observed but which may occur in the far-distant future. Once the simulations have been performed, however, they still need to be tested. The SCEC-USGS dynamic rupture code verification exercise provides a testing mechanism for simulations that involve spontaneous earthquake rupture. We have performed this examination for the specific computer code that was used to predict maximum possible ground motion near Yucca Mountain. Our SCEC-USGS group exercises have demonstrated that the specific computer code that was used for the Yucca Mountain simulations produces similar results to those produced by other computer codes when tackling the same science problem. We also found that the 3D ground motion simulations produced smaller ground motions than the 2D simulations.

Harris, R.A.; Barall, M.; Andrews, D.J.; Duan, B.; Ma, S.; Dunham, E.M.; Gabriel, A.-A.; Kaneko, Y.; Kase, Y.; Aagaard, B.T.; Oglesby, D.D.; Ampuero, J.-P.; Hanks, T.C.; Abrahamson, N.

2011-01-01

107

Method to detect line-to-ground faults in high-resistance-ground networks  

Microsoft Academic Search

An Industrial-Power-Converter-System (IPCS) is a system made up of several power converters, such as Adjustable Speed Drive (ASDs), filters, and any kind of reactive power-compensation components. Today, an IPCS requires the ability to accurately detect and isolate electric faults to avoid further compromise of the integrity of the whole system. One particular type of electric fault is the cable line-to-ground

Carlos D. Rodríguez-Valdez; Russ J. Kerkman

2010-01-01

108

Evaluation of aerial survey methods for Dall's sheep  

USGS Publications Warehouse

Most Dall's sheep (Ovis dalli dalli) population-monitoring efforts use intensive aerial surveys with no attempt to estimate variance or adjust for potential sightability bias. We used radiocollared sheep to assess factors that could affect sightability of Dall's sheep in standard fixed-wing and helicopter surveys and to evaluate feasibility of methods that might account for sightability bias. Work was conducted in conjunction with annual aerial surveys of Dall's sheep in the western Baird Mountains, Alaska, USA, in 2000-2003. Overall sightability was relatively high compared with other aerial wildlife surveys, with 88% of the available, marked sheep detected in our fixed-wing surveys. Total counts from helicopter surveys were not consistently larger than counts from fixed-wing surveys of the same units, and detection probabilities did not differ for the 2 aircraft types. Our results suggest that total counts from helicopter surveys cannot be used to obtain reliable estimates of detection probabilities for fixed-wing surveys. Groups containing radiocollared sheep often changed in size and composition before they could be observed by a second crew in units that were double-surveyed. Double-observer methods that require determination of which groups were detected by each observer will be infeasible unless survey procedures can be modified so that groups remain more stable between observations. Mean group sizes increased during our study period, and our logistic regression sightability model indicated that detection probabilities increased with group size. Mark-resight estimates of annual population sizes were similar to sightability-model estimates, and confidence intervals overlapped broadly. We recommend the sightability-model approach as the most effective and feasible of the alternatives we considered for monitoring Dall's sheep populations.

Udevitz, M.S.; Shults, B.S.; Adams, L.G.; Kleckner, C.

2006-01-01

109

MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model - User Guide to Modularization Concepts and the Ground-Water Flow Process  

USGS Publications Warehouse

MODFLOW is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium by using a finite-difference method. Although MODFLOW was designed to be easily enhanced, the design was oriented toward additions to the ground-water flow equation. Frequently there is a need to solve additional equations; for example, transport equations and equations for estimating parameter values that produce the closest match between model-calculated heads and flows and measured values. This report documents a new version of MODFLOW, called MODFLOW-2000, which is designed to accommodate the solution of equations in addition to the ground-water flow equation. This report is a user's manual. It contains an overview of the old and added design concepts, documents one new package, and contains input instructions for using the model to solve the ground-water flow equation.

Harbaugh, Arlen W.; Banta, Edward R.; Hill, Mary C.; McDonald, Michael G.

2000-01-01

110

Advanced signal processing method for ground penetrating radar feature detection and enhancement  

NASA Astrophysics Data System (ADS)

This paper focuses on new signal processing algorithms customized for an air coupled Ultra-Wideband (UWB) Ground Penetrating Radar (GPR) system targeting highway pavements and bridge deck inspections. The GPR hardware consists of a high-voltage pulse generator, a high speed 8 GSps real time data acquisition unit, and a customized field-programmable gate array (FPGA) control element. In comparison to most existing GPR system with low survey speeds, this system can survey at normal highway speed (60 mph) with a high horizontal resolution of up to 10 scans per centimeter. Due to the complexity and uncertainty of subsurface media, the GPR signal processing is important but challenging. In this GPR system, an adaptive GPR signal processing algorithm using Curvelet Transform, 2D high pass filtering and exponential scaling is proposed to alleviate noise and clutter while the subsurface features are preserved and enhanced. First, Curvelet Transform is used to remove the environmental and systematic noises while maintain the range resolution of the B-Scan image. Then, mathematical models for cylinder-shaped object and clutter are built. A two-dimension (2D) filter based on these models removes clutter and enhances the hyperbola feature in a B-Scan image. Finally, an exponential scaling method is applied to compensate the signal attenuation in subsurface materials and to improve the desired signal feature. For performance test and validation, rebar detection experiments and subsurface feature inspection in laboratory and field configurations are performed.

Zhang, Yu; Venkatachalam, Anbu Selvam; Huston, Dryver; Xia, Tian

2014-03-01

111

Grounded action research: a method for understanding IT in practice  

Microsoft Academic Search

This paper shows how the theory development portion of action research can be made more rigorous. The process of theory formulation is an essential part of action research, yet this process is not well understood. A case study demonstrates how units of analysis and techniques from grounded theory can be integrated into the action research cycle in order to add

Richard Baskerville; Jan Pries-Heje

1999-01-01

112

A Novel Method of Enhancing Grounded Theory Memos with Voice Recording  

ERIC Educational Resources Information Center

In this article the authors present the recent discovery of a novel method of supplementing written grounded theory memos with voice recording, the combination of which may provide significant analytical advantages over solely the traditional written method. Memo writing is an essential component of a grounded theory study, however it is often…

Stocker, Rachel; Close, Helen

2013-01-01

113

The National Criminal Justice Treatment Practices survey: Multilevel survey methods and procedures?  

PubMed Central

The National Criminal Justice Treatment Practices (NCJTP) survey provides a comprehensive inquiry into the nature of programs and services provided to adult and juvenile offenders involved in the justice system in the United States. The multilevel survey design covers topics such as the mission and goals of correctional and treatment programs; organizational climate and culture for providing services; organizational capacity and needs; opinions of administrators and staff regarding rehabilitation, punishment, and services provided to offenders; treatment policies and procedures; and working relationships between correctional and other agencies. The methodology generates national estimates of the availability of programs and services for offenders. This article details the methodology and sampling frame for the NCJTP survey, response rates, and survey procedures. Prevalence estimates of juvenile and adult offenders under correctional control are provided with externally validated comparisons to illustrate the veracity of the methodology. Limitations of the survey methods are also discussed. PMID:17383548

Taxman, Faye S.; Young, Douglas W.; Wiersema, Brian; Rhodes, Anne; Mitchell, Suzanne

2007-01-01

114

Digital certificates: a survey of revocation methods  

Microsoft Academic Search

Digital certificates form a basis that allows entities to trust each other. Due to different constraints, a certificate is only valid within a specific period of time. Coming from several threats, there are important reasons why its validity must be terminated sooner than assigned and thus, the certificate needs to be revoked. This paper provides a classification of revocation methods

Petra Wohlmacher

2000-01-01

115

BOREHOLE SENSING METHODS FOR GROUND-WATER INVESTIGATIONS AT HAZARDOUS WASTE SITES  

EPA Science Inventory

Geophysical methods are becoming a cost effective approach to providing answers to hydrogeologic questions associated with ground-water contamination. Geophysical methods applicable to hazardous waste site investigations can be broken into two categories: surface and subsurface m...

116

A Survey of Quantum Lyapunov Control Methods  

PubMed Central

The condition of a quantum Lyapunov-based control which can be well used in a closed quantum system is that the method can make the system convergent but not just stable. In the convergence study of the quantum Lyapunov control, two situations are classified: nondegenerate cases and degenerate cases. For these two situations, respectively, in this paper the target state is divided into four categories: the eigenstate, the mixed state which commutes with the internal Hamiltonian, the superposition state, and the mixed state which does not commute with the internal Hamiltonian. For these four categories, the quantum Lyapunov control methods for the closed quantum systems are summarized and analyzed. Particularly, the convergence of the control system to the different target states is reviewed, and how to make the convergence conditions be satisfied is summarized and analyzed. PMID:23766732

2013-01-01

117

Checklist and Pollard Walk butterfly survey methods on public lands  

USGS Publications Warehouse

Checklist and Pollard Walk butterfly survey methods were contemporaneously applied to seven public sites in North Dakota during the summer of 1995. Results were compared for effect of method and site on total number of butterflies and total number of species detected per hour. Checklist searching produced significantly more butterfly detections per hour than Pollard Walks at all sites. Number of species detected per hour did not differ significantly either among sites or between methods. Many species were detected by only one method, and at most sites generalist and invader species were more likely to be observed during checklist searches than during Pollard Walks. Results indicate that checklist surveys are a more efficient means for initial determination of a species list for a site, whereas for long-term monitoring the Pollard Walk is more practical and statistically manageable. Pollard Walk transects are thus recommended once a prairie butterfly fauna has been defined for a site by checklist surveys.

Royer, R.A.; Austin, J.E.; Newton, W.E.

1998-01-01

118

Survey of assay methods of antivenins  

PubMed Central

In view of the multiplicity of methods used at present for the preparation and assay of antivenins and as a first step towards the international standardization of antivenins, it seemed advisable to make a comparative study of the methods used in the institutes specializing in the production of these sera. With this end in view, the author circulated to the serologists of institutes concerned a detailed questionnaire on the assay methods used for the determination of the neutralization potency of the various types of antivenins prepared under their direction. The information supplied by these institutes is reproduced, in condensed form, in this report and is analysed by the author. The author emphasizes that the great variety in the constitution of venoms necessitates: (1) the use of monovalent standard sera against homologous “test” venoms of high activity and stability; and (2) the establishment, on a regional basis, of standard antivenins corresponding to groups of snakes characterized by venoms of common or closely related antigenic constitution. PMID:13413648

Grasset, E.

1957-01-01

119

Formulation and survey of ALE method in nonlinear solid mechanics  

Microsoft Academic Search

This paper investigates the applicability and accuracy of existing formulation methods in general purpose finite element programs to the finite strain deformation problems. The basic shortcomings in using such programs in these applications are then pointed out and the need for a different type of formulation is discussed. An arbitrary Lagrangian-Eulerian (ALE) method is proposed and a concise survey of

J. Wang; M. S. Gadala

1997-01-01

120

A European food consumption survey method–conclusions and recommendations  

Microsoft Academic Search

Objective: To discuss the general outcome and conclusions of a European project (EFCOSUM); to develop a method for a European food consumption survey that delivers internationally comparable data on a set of policy relevant nutritional indicators.Design and methods: The EFCOSUM project was carried out within the framework of the European Health Monitoring Programme by 14 Member States as well as

JH Brussaard; MRH Löwik; L Steingrímsdóttir; A Møller; J Kearney; S De Henauw; W Becker

2002-01-01

121

Survey of methods for soil moisture determination  

NASA Technical Reports Server (NTRS)

Existing and proposed methods for soil moisture determination are discussed. These include: (1) in situ investigations including gravimetric, nuclear, and electromagnetic techniques; (2) remote sensing approaches that use the reflected solar, thermal infrared, and microwave portions of the electromagnetic spectrum; and (3) soil physics models that track the behavior of water in the soil in response to meteorological inputs (precipitation) and demands (evapotranspiration). The capacities of these approaches to satisfy various user needs for soil moisture information vary from application to application, but a conceptual scheme for merging these approaches into integrated systems to provide soil moisture information is proposed that has the potential for meeting various application requirements.

Schmugge, T. J.; Jackson, T. J.; Mckim, H. L.

1979-01-01

122

Geological disaster survey based on Curvelet transform with borehole Ground Penetrating Radar in Tonglushan old mine site.  

PubMed

Tonglushan old mine site located in Huangshi City, China, is very famous in the world. However, some of the ruins had suffered from geological disasters such as local deformation, surface cracking, in recent years. Structural abnormalities of rock-mass in deep underground were surveyed with borehole ground penetrating radar (GPR) to find out whether there were any mined galleries or mined-out areas below the ruins. With both the multiresolution analysis and sub-band directional of Curvelet transform, the feature information of targets' GPR signals were studied on Curvelet transform domain. Heterogeneity of geotechnical media and clutter jamming of complicated background of GPR signals could be conquered well, and the singularity characteristic information of typical rock mass signals could be extracted. Random noise had be removed by thresholding combined with Curvelet and the statistical characteristics of wanted signals and the noise, then direct wave suppression and the spatial distribution feature extraction could obtain a better result by making use of Curvelet transform directional. GprMax numerical modeling and analyzing of the sample data have verified the feasibility and effectiveness of our method. It is important and applicable for the analyzing of the geological structure and the disaster development about the Tonglushan old mine site. PMID:25084600

Tang, Xinjian; Sun, Tao; Tang, Zhijie; Zhou, Zenghui; Wei, Baoming

2011-06-01

123

Numerical Calculation Method for Prediction of Ground-borne Vibration near Subway Tunnel  

Microsoft Academic Search

This paper describes the development of prediction method for ground-borne vibration from railway tunnels. Field measurement was carried out both in a subway shield tunnel, in the ground and on the ground surface. The generated vibration in the tunnel was calculated by means of the train\\/track\\/tunnel interaction model and was compared with the measurement results. On the other hand, wave

Kiwamu Tsuno; Masaru Furuta; Kazuhisa Abe

2010-01-01

124

Ground penetrating radar surveys over an alluvial DNAPL site, Paducah Gaseous Diffusion Plant, Kentucky  

SciTech Connect

Ground penetrating radar (GPR) surveys were used to map shallow sands and gravels which are DNAPL migration pathways at the Paducah Gaseous Diffusion Plant in western Kentucky. The sands and gravels occur as paleochannel deposits, at depths of 17-25 ft, embedded in Pleistocene lacustrine clays. More than 30 GPR profiles were completed over the Drop Test Area (DTA) to map the top and base of the paleochannel deposits, and to assess their lateral continuity. A bistatic radar system was used with antenna frequencies of 25 and 50 MHz. An average velocity of 0.25 ft/ns for silty and clayey materials above the paleochannel deposits was established from radar walkaway tests, profiles over culverts of known depth, and comparison of radar sections with borings. In the south portion of the DTA, strong reflections corresponded to the water table at approximately 9-10 ft, the top of the paleochannel deposits at approximately 18 ft, and to gravel horizons within these deposits. The base of these deposits was not visible on the radar sections. Depth estimates for the top of the paleochannel deposits (from 50 records) were accurate to within 2 ft across the southern portion of the DTA. Continuity of these sands and gravels could not be assessed due to interference from air-wave reflections and lateral changes in signal penetration depth. However, the sands and gravels appear to extend across the entire southern portion of the DTA, at depths as shallow as 17 ft. Ringing, air-wave reflections and diffractions from powerlines, vehicles, well casings, and metal equipment severly degraded GPR profiles in the northern portion of the DTA; depths computed from reflection times (where visible) were accurate to within 4 ft in this area. The paleochannel deposits are deeper to the north and northeast where DNAPL has apparently pooled (DNAPL was not directly imaged by the GPR, however). Existing hydrogeological models of the DTA will be revised.

Carpenter, P.J. [Northern Illinois Univ., DeKalb, IL (United States). Dept. of Geology]|[Oak Ridge National Lab., TN (United States); Doll, W.E. [Oak Ridge National Lab., TN (United States); Phillips, B.E. [Paducah Gaseous Diffusion Plant, KY (United States)

1994-09-01

125

Health-based screening levels to evaluate U.S. Geological Survey ground water quality data  

USGS Publications Warehouse

Federal and state drinking-water standards and guidelines do not exist for many contaminants analyzed by the U.S. Geological Survey's National Water-Quality Assessment Program, limiting the ability to evaluate the potential human-health relevance of water-quality findings. Health-based screening levels (HBSLs) were developed collaboratively to supplement existing drinking-water standards and guidelines as part of a six-year, multi-agency pilot study. The pilot study focused on ground water samples collected prior to treatment or blending in areas of New Jersey where groundwater is the principal source of drinking water. This article describes how HBSLs were developed and demonstrates the use of HBSLs as a tool for evaluating water-quality data in a human-health context. HBSLs were calculated using standard U.S. Environmental Protection Agency (USEPA) methodologies and toxicity information. New HBSLs were calculated for 12 of 32 contaminants without existing USEPA drinking-water standards or guidelines, increasing the number of unregulated contaminants (those without maximum contaminant levels (MCLs)) with human-health benchmarks. Concentrations of 70 of the 78 detected contaminants with human-health benchmarks were less than MCLs or HBSLs, including all 12 contaminants with new HBSLs, suggesting that most contaminant concentrations were not of potential human-health concern. HBSLs were applied to a state-scale groundwater data set in this study, but HBSLs also may be applied to regional and national evaluations of water-quality data. HBSLs fulfill a critical need for federal, state, and local agencies, water utilities, and others who seek tools for evaluating the occurrence of contaminants without drinking-water standards or guidelines. ?? 2006 Society for Risk Analysis.

Toccalino, P.L.; Norman, J.E.

2006-01-01

126

Health-based screening levels to evaluate U.S. Geological Survey ground water quality data.  

PubMed

Federal and state drinking-water standards and guidelines do not exist for many contaminants analyzed by the U.S. Geological Survey's National Water-Quality Assessment Program, limiting the ability to evaluate the potential human-health relevance of water-quality findings. Health-based screening levels (HBSLs) were developed collaboratively to supplement existing drinking-water standards and guidelines as part of a six-year, multi-agency pilot study. The pilot study focused on ground water samples collected prior to treatment or blending in areas of New Jersey where groundwater is the principal source of drinking water. This article describes how HBSLs were developed and demonstrates the use of HBSLs as a tool for evaluating water-quality data in a human-health context. HBSLs were calculated using standard U.S. Environmental Protection Agency (USEPA) methodologies and toxicity information. New HBSLs were calculated for 12 of 32 contaminants without existing USEPA drinking-water standards or guidelines, increasing the number of unregulated contaminants (those without maximum contaminant levels (MCLs)) with human-health benchmarks. Concentrations of 70 of the 78 detected contaminants with human-health benchmarks were less than MCLs or HBSLs, including all 12 contaminants with new HBSLs, suggesting that most contaminant concentrations were not of potential human-health concern. HBSLs were applied to a state-scale groundwater data set in this study, but HBSLs also may be applied to regional and national evaluations of water-quality data. HBSLs fulfill a critical need for federal, state, and local agencies, water utilities, and others who seek tools for evaluating the occurrence of contaminants without drinking-water standards or guidelines. PMID:17054535

Toccalino, Patricia L; Norman, Julia E

2006-10-01

127

Ground Water  

NSDL National Science Digital Library

This United States Geological Survey (USGS) general interest publication presents a description of ground water in the U.S. This includes what ground water is, how it occurs, aquifers and wells, ground water quality and what affects it, and the state of U.S. ground water resources.

128

Optimal filtering methods to structural damage estimation under ground excitation.  

PubMed

This paper considers the problem of shear building damage estimation subject to earthquake ground excitation using the Kalman filtering approach. The structural damage is assumed to take the form of reduced elemental stiffness. Two damage estimation algorithms are proposed: one is the multiple model approach via the optimal two-stage Kalman estimator (OTSKE), and the other is the robust two-stage Kalman filter (RTSKF), an unbiased minimum-variance filtering approach to determine the locations and extents of the damage stiffness. A numerical example of a six-storey shear plane frame structure subject to base excitation is used to illustrate the usefulness of the proposed results. PMID:24453869

Hsieh, Chien-Shu; Liaw, Der-Cherng; Lin, Tzu-Hsuan

2013-01-01

129

Optimal Filtering Methods to Structural Damage Estimation under Ground Excitation  

PubMed Central

This paper considers the problem of shear building damage estimation subject to earthquake ground excitation using the Kalman filtering approach. The structural damage is assumed to take the form of reduced elemental stiffness. Two damage estimation algorithms are proposed: one is the multiple model approach via the optimal two-stage Kalman estimator (OTSKE), and the other is the robust two-stage Kalman filter (RTSKF), an unbiased minimum-variance filtering approach to determine the locations and extents of the damage stiffness. A numerical example of a six-storey shear plane frame structure subject to base excitation is used to illustrate the usefulness of the proposed results. PMID:24453869

Hsieh, Chien-Shu; Liaw, Der-Cherng; Lin, Tzu-Hsuan

2013-01-01

130

MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model -- GMG Linear Equation Solver Package Documentation  

USGS Publications Warehouse

A geometric multigrid solver (GMG), based in the preconditioned conjugate gradient algorithm, has been developed for solving systems of equations resulting from applying the cell-centered finite difference algorithm to flow in porous media. This solver has been adapted to the U.S. Geological Survey ground-water flow model MODFLOW-2000. The documentation herein is a description of the solver and the adaptation to MODFLOW-2000.

Wilson, John D.; Naff, Richard L.

2004-01-01

131

Statistical methods in rehabilitation literature: A survey of recent publications  

Microsoft Academic Search

Objective: To document the use of statistical methods in the recent rehabilitation research literature.Design: Descriptive survey study.Methods: All 1,039 articles published between January 1990 and December 1993 in the American Journal of Physical Medicine and Rehabilitation and the Archives of Physical Medicine and Rehabilitation were reviewed for the use of statistical methods.Results: There were 682 (66%) research articles in the

Staci J. Schwartz; Marianne Sturr; Gary Goldberg

1996-01-01

132

Movement and fate of creosote waste in ground water, Pensacola, Florida; U.S. Geological Survey toxic waste--ground-water contamination program  

USGS Publications Warehouse

In 1983, the U.S. Geological Survey, Office of Hazardous Waste Hydrology, selected the former American Creosote Works site near Pensacola, Florida as a national research demonstration area. Seventy-nine years (1902-81) of seepage from unlined discharge impoundments had released creosote, diesel fuel, and pentachlorophenol (since 1950) wastes into the ground-water system. A cluster of from 2 to 5 wells constructed at different depths at 9 sites yielded water which revealed contamination 600 feet downgradient and to a depth of 100 feet below land surface near the site. The best cross-sectional representation of the contaminant plume was obtained from samples collected and analyzed for oxidation-reduction sensitive inorganic chemical constituents. Energy dispersive x-ray fluorescence detected recently formed iron carbonate in soil samples from highly reducing ground-water zones. Approximately eighty specific organic contaminants were isolated from ground-water samples by gas-chromotography/mass spectrometry. Column studies indicate the dimethyl phenols are not sorbed or degraded by the sand-and-gravel aquifer materials. Five of nineteen individual phenolic and related compounds are biodegradable based on anaerobic digestor experiments with ACW site bacterial populations. The potential impacts in the nearby Pensacola Bay biotic community are being evaluated. (USGS)

Mattraw, H. C., Jr.,(Edited By); Franks, B.J.

1984-01-01

133

Grounded Theory as a "Family of Methods": A Genealogical Analysis to Guide Research  

ERIC Educational Resources Information Center

This study traces the evolution of grounded theory from a nuclear to an extended family of methods and considers the implications that decision-making based on informed choices throughout all phases of the research process has for realizing the potential of grounded theory for advancing adult education theory and practice. [This paper was…

Babchuk, Wayne A.

2011-01-01

134

Affect of mechanical properties changes of injecting cement paste on ground settlement with shield driven method  

Microsoft Academic Search

When using shield driven method to construct tunnels, mechanical properties of injecting cement paste will change at curing age. And then ground settlement will also change because of changes of mechanical properties of injecting cement paste. Based on the first line of Ningbo rail transit, this paper will discuss the effect of ground settlement caused by changes of elastic modulus

Tao Gan; Wen-jun Wang; Xiao-nan Gong

2011-01-01

135

An aerial survey method to estimate sea otter abundance  

USGS Publications Warehouse

Sea otters (Enhydra lutris) occur in shallow coastal habitats and can be highly visible on the sea surface. They generally rest in groups and their detection depends on factors that include sea conditions, viewing platform, observer technique and skill, distance, habitat and group size. While visible on the surface, they are difficult to see while diving and may dive in response to an approaching survey platform. We developed and tested an aerial survey method that uses intensive searches within portions of strip transects to adjust for availability and sightability biases. Correction factors are estimated independently for each survey and observer. In tests of our method using shore-based observers, we estimated detection probabilities of 0.52-0.72 in standard strip-transects and 0.96 in intensive searches. We used the survey method in Prince William Sound, Alaska to estimate a sea otter population size of 9,092 (SE = 1422). The new method represents an improvement over various aspects of previous methods, but additional development and testing will be required prior to its broad application.

Bodkin, J.L.; Udevitz, M.S.

1999-01-01

136

Karstic risk assessment in a coastal area using microgravimetric and Ground-penetrating radar geophysical methods;  

NASA Astrophysics Data System (ADS)

The geomorphological characteristics of the Salento peninsula (Puglia, south-eastern Italy) mean that movements of mass are extremely rare. These phenomena particularly affect certain coastal zones characterized by cliffs in rapid retreat and some unusual points in the hinterland in which collapses, generally linked to the development of karstic cavities, are common. These phenomena demonstrate the brittleness of some areas of the Salento and they constitute a restraint on the use of the territory itself. The coastal area named "Marina di Capilungo" located at about 50km south-west part of Lecce (Salento peninsula - Italy) is one of the sites at greatest geological risk in the Salento peninsula. In the last few decades, "Marina di Capilungo" has been affected by a series of subsidence events, which have, in some cases, resulted in the partial collapse of buildings and road surfaces. These events have had both social repercussions, causing alarm and emergency situations, and economic repercussions in terms of the expense of restoration. With the purpose of estimating the dimensions of the phenomenon to prevent and/or to limit the ground subsidence events, integrated geophysical surveys were undertaken in an area of about 70000m2 at "Marina di Capilungo". Microgravimetric and ground-penetrating radar (GPR) geophysical methods were used. By using small station spacing and careful processing for the geophysical data, and by modelling these data with topographic information, accurate interpretation was obtained. Combining the two geophysical methods help in the interpretation. In fact GPR method can be complement microgravimetric method in determining cavity depths and in verifying the presence of off-line features and numerous areas of small cavities which may be difficult to resolve in microgravimetric data; on the other hand the microgravimetry can complement GPR method for accurately delineating a shallow cavities in a wide area where GPR measurements are difficult to perform. The case study show how the recorded microgravity anomalies have revealed, with the help of GPR recorded anomalies, the location of density variations associated with underground cave systems.

Leucci, G.; de Giorgi, L.

2009-04-01

137

Aerial Survey Results for 131I Deposition on the Ground after the Fukushima Daiichi Nuclear Power Plant Accident  

SciTech Connect

In March 2011 the second largest accidental release of radioactivity in history occurred at the Fukushima Daiichi nuclear power plant following a magnitude 9.0 earthquake and subsequent tsunami. Teams from the U.S. Department of Energy, National Nuclear Security Administration Office of Emergency Response performed aerial surveys to provide initial maps of the dispersal of radioactive material in Japan. The initial results from the surveys did not report the concentration of 131I. This work reports on analyses performed on the initial survey data by a joint Japan-US collaboration to determine 131I ground concentration. This information is potentially useful in reconstruction of the inhalation and external exposure doses from this short-lived radionuclide. The deposited concentration of 134Cs is also reported.

Torii, Tatsuo [JAEA; Sugita, Takeshi [JAEA; Okada, Colin E. [NSTec; Reed, Michael S. [NSTec; Blumenthal, Daniel J. [NNSA

2013-08-01

138

Prenotification, Incentives, and Survey Modality: An Experimental Test of Methods to Increase Survey Response Rates of School Principals  

ERIC Educational Resources Information Center

Teacher and principal surveys are among the most common data collection techniques employed in education research. Yet there is remarkably little research on survey methods in education, or about the most cost-effective way to raise response rates among teachers and principals. In an effort to explore various methods for increasing survey response…

Jacob, Robin Tepper; Jacob, Brian

2012-01-01

139

A Survey of Computer Methods in Forensic Handwritten Document Examination  

E-print Network

1 A Survey of Computer Methods in Forensic Handwritten Document Examination Sargur SRIHARI Graham LEEDHAM Abstract Forensic document examination is at a cross-roads due to challenges posed to its recent efforts in the areas of establishing a scientific basis of forensic handwriting examination

140

A Survey of Methods for Pure Nonlinear Integer Programming  

Microsoft Academic Search

The subject of this paper is a classification and discussion of algorithms for solution of nonlinear pure integer programming problems. The survey is organized by characterizing the mathematical form of the nonlinear optimization problems addressed by the various algorithms. If any method can be used without changes to solve mixed integer nonlinear programming problems that fact is mentioned in the

Mary W. Cooper

1981-01-01

141

Methods for Allocating Urban Emergency Units: A Survey  

Microsoft Academic Search

An urban emergency service system provides mobile units (vehicles) to respond to requests for service which can occur at any time and any place throughout a city. This paper describes the common characteristics and operational problems of these systems and surveys the various methods, both traditional and recently developed, which may be used for allocating their units. Aspects of allocation

Jan M. Chaiken; Richard C. Larson

1972-01-01

142

System and method for transferring telemetry data between a ground station and a control center  

NASA Technical Reports Server (NTRS)

Disclosed herein are systems, computer-implemented methods, and tangible computer-readable media for coordinating communications between a ground station, a control center, and a spacecraft. The method receives a call to a simple, unified application programmer interface implementing communications protocols related to outer space, when instruction relates to receiving a command at the control center for the ground station generate an abstract message by agreeing upon a format for each type of abstract message with the ground station and using a set of message definitions to configure the command in the agreed upon format, encode the abstract message to generate an encoded message, and transfer the encoded message to the ground station, and perform similar actions when the instruction relates to receiving a second command as a second encoded message at the ground station from the control center and when the determined instruction type relates to transmitting information to the control center.

Ray, Timothy J. (Inventor); Ly, Vuong T. (Inventor)

2012-01-01

143

Ground penetrating radar survey of the ice-filled active crater of Mount Baker, Washington  

NASA Astrophysics Data System (ADS)

Sherman Crater, the center of volcanic activity at Mount Baker, in northwest Washington, provides an excellent site to study glacier dynamics in an active crater because of its history of sudden, significant increases in geothermal activity, its confined geometry, the potential hazards it poses to downstream reservoirs, and the paucity of recent research related to these hazards. We present results from a ground penetrating radar (GPR) survey of the crater conducted in the summers of 2009 and 2010, including characterization of the subglacial crater morphology, estimates for the crater glacier’s volume, maximum depth, annual mass balance and surface velocity and for the crater’s geothermal flux density. We used a GSSI SIR-3000 GPR system and a low frequency (80 MHz) antenna in common-offset (reflection) collection mode to image subglacial conditions along several west-east and south-north transects within the crater. We processed the GPR data with GSSI’s RADAN 6.0 and paired the surface elevations of each transect to the ice-surface topography using GPS locations and spot altimeter readings. GPR profiles reveal several sets of distinct basal and englacial reflectors. Along west-east (longitudinal) transects, the crater’s bedrock topography largely follows the glacier’s surface (high to the west, descending to the east), but the ice thins dramatically along the margin nearest the crater rim’s eastern breach. The prominent basal reflectors in the GPR transects are consistent with an ice/hydrothermally altered rock interface, but short more well-defined segments suggest the presence of bedrock (towards the center of the crater) and water (near the eastern breach) at the base of the ice. GPR data combined with surface ice melting measurements yield a first-order estimate for the area-averaged accumulation rate of 4.8 +/- 0.1 m yr-1 and ablation rate of 2.4 +/- 0.3 m yr-1 water equivalent from surface melting. The resulting calculated geothermal flux for Sherman Crater of ~20 Wm-2 is consistent with published calculations for active calderas (Mt. Veniaminof) and volcanic lakes. We estimate the maximum ice thickness to be ~50 m, and the ice velocity to range from ~3 to 4 m/month during the summer months. Highest surface ice velocities are found on moderate slopes above the deepest part of the crater, where the ice is thickest (inferred from GPR profiles).

Park, M.; Clark, D. H.; Caplan-Auerbach, J.

2010-12-01

144

Ice thickness profile surveying with ground penetrating radar at Artesonraju Glacier, Peru  

NASA Astrophysics Data System (ADS)

Tropical glaciers are an essential component of the water resource systems in the mountainous regions where they are located, and a warming climate has resulted in the accelerated retreat of Andean glaciers in recent decades. The shrinkage of Andean glaciers influences the flood risk for communities living downstream as new glacial lakes have begun to form at the termini of some glaciers. As these lakes continue to grow in area and volume, they pose an increasing risk of glacial lake outburst floods (GLOFs). Ice thickness measurements have been a key missing link in studying the tropical glaciers in Peru and how climate change is likely to impact glacial melt and the growth of glacial lakes. Ground penetrating radar (GPR) has rarely been applied to glaciers in Peru to measure ice thickness, and these measurements can tell us a lot about how a warming climate will affect glaciers in terms of thickness changes. In the upper Paron Valley (Cordillera Blanca, Peru), an emerging lake has begun to form at the terminus of the Artesonraju Glacier, and this lake has key features, including overhanging ice and loose rock likely to create slides, that could trigger a catastrophic GLOF if the lake continues to grow. Because the glacier mass balance and lake mass balance are closely linked, ice thickness measurements and measurements of the bed slope of the Artesonraju Glacier and underlying bedrock can give us an idea of how the lake is likely to evolve in the coming decades. This study presents GPR data taken in July 2013 at the Artesonraju Glacier as part of a collaboration between the Unidad de Glaciologia y Recursos Hidricos (UGRH) of Peru, the Institut de Recherche pour le Développement (IRD) of France and the University of Texas at Austin (UT) of the United States of America. Two different GPR units belonging to UGRH and UT were used for subsurface imaging to create ice thickness profiles and to characterize the total volume of ice in the glacier. A common midpoint survey was also undertaken to determine the radar velocity in the ice at Artesonraju Glacier. GPR measurements of Artesonraju Glacier show the ice thickness ranging from 20 meters at the terminus and gradually increasing to about 160 meters at the deepest part in the tongue of the glacier. After this point the bed slope begins to increase and the ice thickness decreases in the direction of the accumulation zone. A negative bed slope from the glacier terminus to the middle of the glacier tongue indicates that the conditions are favorable for the growth of a glacial lake with a potential maximum depth of about 60-80 m.

Chisolm, Rachel; Rabatel, Antoine; McKinney, Daene; Condom, Thomas; Cochacin, Alejo; Davila Roller, Luzmilla

2014-05-01

145

Ground effects on V/STOL and STOL aircraft - A survey  

NASA Technical Reports Server (NTRS)

The flow fields encountered by jet- and fan-powered Vertical/Short Takeoff and Landing (V/STOL) aircraft operating in ground effect are reviewed and their general effects on the aerodynamic characteristics are discussed. The ground effects considered include (1) the suckdown experienced by a single jet configuration in hover, (2) the fountain flow and additional suckdown experienced by multiple jet configurations in hover, (3) the ground vortex generated by jet and jet flap configurations in Short Takeoff and Landing (STOL) operation and the associated aerodynamic and hot-gas-ingestion effects, and (4) the change in the downwash at the tail due to ground proximity. After over 30 years of research on V/STOL aircraft, the general flow phenomena are well known and, in most areas, the effects of ground proximity can be estimated or can be determined experimentally. However, there are some anomalies in the current data base which are discussed.

Eshlemen, J.; Kuhn, R. E.

1985-01-01

146

Ground effects on V/STOL and STOL aircraft: A survey  

NASA Technical Reports Server (NTRS)

The flow fields encountered by jet- and fan-powered Vertical/Short Takeoff and Landing (V/STOL) aircraft operating in ground effect are reviewed and their general effects on the aerodynamic characteristics are discussed. The ground effects considered include: (1) the suckdown experienced by a single jet configuration in hover; (2) the fountain flow and additional suckdown experienced by multiple jet configurations in hover; (3) the ground vortex generated by jet and jet flap configurations in short takeoff and landing (STOL) operation and the associated aerodynamic and hot-gas-ingestion effects; and (4) the change in the downwash at the tail due to ground proximity. After over 30 years of research on V/STOL aircraft, the general flow phenomena are well-known and, in most areas, the effects of ground proximity can be established or can be determined experimentally. However, there are some anomalies in the current data base which are discussed.

Kuhn, R. E.; Eshleman, J.

1985-01-01

147

A survey of mathematical methods for indoor localization  

Microsoft Academic Search

This document provides a survey of the mathematical methods currently used for position estimation in indoor local positioning systems (LPS), particularly those based on radiofrequency signals. The techniques are grouped into four categories: geometry-based methods, minimization of the cost function, fingerprinting, and Bayesian techniques. Comments on the applicability, requirements, and immunity to nonline-of-sight (NLOS) propagation of the signals of each

Fernando Seco; Antonio R. Jimenez; Carlos Prieto; Javier Roa; Katerina Koutsou

2009-01-01

148

Survey of methods for calculating sensitivity of general eigenproblems  

NASA Technical Reports Server (NTRS)

A survey of methods for sensitivity analysis of the algebraic eigenvalue problem for non-Hermitian matrices is presented. In addition, a modification of one method based on a better normalizing condition is proposed. Methods are classified as Direct or Adjoint and are evaluated for efficiency. Operation counts are presented in terms of matrix size, number of design variables and number of eigenvalues and eigenvectors of interest. The effect of the sparsity of the matrix and its derivatives is also considered, and typical solution times are given. General guidelines are established for the selection of the most efficient method.

Murthy, Durbha V.; Haftka, Raphael T.

1987-01-01

149

Methods and Indicators for Assessment of Regional Ground-Water Conditions in the Southwestern United States  

USGS Publications Warehouse

Monitoring the status and trends in the availability of the Nation's ground-water supplies is important to scientists, planners, water managers, and the general public. This is especially true in the semiarid to arid southwestern United States where rapid population growth and limited surface-water resources have led to increased use of ground-water supplies and water-level declines of several hundred feet in many aquifers. Individual well observations may only represent aquifer conditions in a limited area, and wells may be screened over single or multiple aquifers, further complicating single-well interpretations. Additionally, changes in ground-water conditions may involve time scales ranging from days to many decades, depending on the timing of recharge, soil and aquifer properties, and depth to the water table. The lack of an easily identifiable ground-water property indicative of current conditions, combined with differing time scales of water-level changes, makes the presentation of ground-water conditions a difficult task, particularly on a regional basis. One approach is to spatially present several indicators of ground-water conditions that address different time scales and attributes of the aquifer systems. This report describes several methods and indicators for presenting differing aspects of ground-water conditions using water-level observations in existing data-sets. The indicators of ground-water conditions developed in this study include areas experiencing water-level decline and water-level rise, recent trends in ground-water levels, and current depth to ground water. The computer programs written to create these indicators of ground-water conditions and display them in an interactive geographic information systems (GIS) format are explained and results illustrated through analyses of ground-water conditions for selected alluvial basins in the Lower Colorado River Basin in Arizona.

Tillman, Fred D.; Leake, Stanley A.; Flynn, Marilyn E.; Cordova, Jeffrey T.; Schonauer, Kurt T.; Dickinson, Jesse E.

2008-01-01

150

Making Ground-Based Optical\\/Infrared Imaging Surveys VO-Compatible  

Microsoft Academic Search

To cope with the rapidly increasing volume and complexity of data being generated by ESO’s public optical\\/infrared imaging\\u000a surveys a high-performance, integrated, end-to-end survey software system has been developed. Its main aim is to provide a\\u000a robust framework to efficiently transform raw data into science-grade survey products. The system consists of several tasks\\u000a wrapped together into an integrated framework. These

Luiz da Costa; Karl-Schwarzschild Str

151

USGS Ground-Water Techniques, Methods, and Models  

NSDL National Science Digital Library

This USGS site offers a collection of documents and resources about groundwater data collection methods and groundwater modeling. The site includes several references for field methods and techniques, including well installation, sample collection, geophysical tools, and the collection of water use data. Groundwater modeling topics cover MODFLOW, HYMOD, SEAWAT, WTAQ, and MOC3D. There is also a link to an index of many groundwater modeling software programs.

USGS

152

GWM-a ground-water management process for the U.S. Geological Survey modular ground-water model (MODFLOW-2000)  

USGS Publications Warehouse

GWM is a Ground?Water Management Process for the U.S. Geological Survey modular three?dimensional ground?water model, MODFLOW?2000. GWM uses a response?matrix approach to solve several types of linear, nonlinear, and mixed?binary linear ground?water management formulations. Each management formulation consists of a set of decision variables, an objective function, and a set of constraints. Three types of decision variables are supported by GWM: flow?rate decision variables, which are withdrawal or injection rates at well sites; external decision variables, which are sources or sinks of water that are external to the flow model and do not directly affect the state variables of the simulated ground?water system (heads, streamflows, and so forth); and binary variables, which have values of 0 or 1 and are used to define the status of flow?rate or external decision variables. Flow?rate decision variables can represent wells that extend over one or more model cells and be active during one or more model stress periods; external variables also can be active during one or more stress periods. A single objective function is supported by GWM, which can be specified to either minimize or maximize the weighted sum of the three types of decision variables. Four types of constraints can be specified in a GWM formulation: upper and lower bounds on the flow?rate and external decision variables; linear summations of the three types of decision variables; hydraulic?head based constraints, including drawdowns, head differences, and head gradients; and streamflow and streamflow?depletion constraints. The Response Matrix Solution (RMS) Package of GWM uses the Ground?Water Flow Process of MODFLOW to calculate the change in head at each constraint location that results from a perturbation of a flow?rate variable; these changes are used to calculate the response coefficients. For linear management formulations, the resulting matrix of response coefficients is then combined with other components of the linear management formulation to form a complete linear formulation; the formulation is then solved by use of the simplex algorithm, which is incorporated into the RMS Package. Nonlinear formulations arise for simulated conditions that include water?table (unconfined) aquifers or head?dependent boundary conditions (such as streams, drains, or evapotranspiration from the water table). Nonlinear formulations are solved by sequential linear programming; that is, repeated linearization of the nonlinear features of the management problem. In this approach, response coefficients are recalculated for each iteration of the solution process. Mixed?binary linear (or mildly nonlinear) formulations are solved by use of the branch and bound algorithm, which is also incorporated into the RMS Package. Three sample problems are provided to demonstrate the use of GWM for typical ground?water flow management problems. These sample problems provide examples of how GWM input files are constructed to specify the decision variables, objective function, constraints, and solution process for a GWM run. The GWM Process runs with the MODFLOW?2000 Global and Ground?Water Flow Processes, but in its current form GWM cannot be used with the Observation, Sensitivity, Parameter?Estimation, or Ground?Water Transport Processes. The GWM Process is written with a modular structure so that new objective functions, constraint types, and solution algorithms can be added.

Ahlfeld, David P.; Barlow, Paul M.; Mulligan, Anne E.

2005-01-01

153

The Karl G. Jansky VLA Sky Survey (VLASS): A Scientific and Technical Proving Ground for the SKA Era  

NASA Astrophysics Data System (ADS)

The Karl G. Jansky Very Large Array is a recently completed rejuvenation of the VLA, providing observers with significantly increased continuum sensitivity and spectral survey speeds from 1-50 GHz and in key bands below 1 GHz. Given the potential for new centimeter-wavelength sky surveys with this enhanced facility, the NRAO has initiated the Jansky VLA Sky Survey (VLASS) program to explore the science and technical opportunities of a new large survey. A community-led Science Survey Group (SSG) will define the science program and key components of VLASS, and NRAO will support its technical design and implementation. The VLASS could start observing in early 2015, with the data available immediately with no proprietary period and science data products provided to the community in a timely manner. The VLASS, in order to carry out its mission in key science areas, will have to address a number of challenges in data management, computation, image processing, and analysis. The development and implementation of capable, efficient, and robust pipeline processing of data, wide-band wide-field high time resolution spectropolarimetric imaging, and the production of a basic suite of science data products such as images and catalogs, are all high priorities for VLASS. We describe these challenges and our approaches to viable solutions, as well as the role of the Jansky VLA and the VLASS as a scientific and technical proving ground for the next generation of facilities in the SKA era.

Myers, Steven T.

2014-04-01

154

Diagnosis of breaks in substation's grounding grid by using the electromagnetic method  

Microsoft Academic Search

According to the method of moment, a new method to analyze the grid fed by harmonic currents is presented. The method can be used for the condition that the grid is in at least ten-layer soil with a frequency of the injected currents up to 1 MHz. There can be more than one injected current, and the grounding conductor of

Bo Zhang; Zhibin Zhao; Xiang Cui; Lin Li

2002-01-01

155

Ground States and Singular Vectors of Convex Variational Regularization Methods  

E-print Network

, Total Variation Regularization, Bregman Distance, Inverse Scale Space Method, Com- pressed Sensing. 1 or total variation regularizations became quite prominent regulariza- tion techniques with certain functionals such as 1 -norms or the total variation are used. In many examples the above mentioned functionals

Burger, Martin

156

Scenistic Methods in Training: Definitions and Theory Grounding  

ERIC Educational Resources Information Center

Purpose: The aim of this article is to describe the scenistic approach to training with corresponding activities and the theory bases that support the approach. Design/methodology/approach: Presented is the definition of the concept of scenistic training along with the step-by-step details of the implementation of the approach. Scenistic methods,…

Lyons, Paul

2010-01-01

157

AgRISTARS: Agriculture and Resources Inventory Surveys Through Aerospace Remote Sensing. Enumerator's manual, 1981 ground data survey  

NASA Technical Reports Server (NTRS)

General information and administrative instructions are provided for individuals gathering ground truth data to support research and development techniques for estimating crop acreage and production by remote sensing by satellite. Procedures are given for personal safety with regards to organophosphorus insecticides, for conducting interviews for periodic observations, for coding the crops identified and their growth stages, and for selecting sites for placing rain gages. Forms are included for those citizens agreeing to monitor the gages and record the rainfall. Segment selection is also considered.

1981-01-01

158

Survey methods and results at: www.umass.edu/oapa/oapa/reports/senior_survey. Office of Academic Planning and Assessment, 11/20/2013 2013 UMass-Amherst Graduating Senior Survey  

E-print Network

Survey methods and results at: www.umass.edu/oapa/oapa/reports/senior_survey. Office of Academic. Survey methods and results at: www.umass.edu/oapa/oapa/reports/senior_survey. Office of Academic Planning

Massachusetts at Amherst, University of

159

Survey methods and results at: www.umass.edu/oapa/oapa/reports/senior_survey. Office of Academic Planning and Assessment, 11/19/2014 2014 UMass-Amherst Graduating Senior Survey  

E-print Network

Survey methods and results at: www.umass.edu/oapa/oapa/reports/senior_survey. Office of Academic (Calendar Year 2014): 5550 Survey Respondents: 4060 Response Rate: 73.2% Survey methods and results at: www

Mountziaris, T. J.

160

Integration of real time kinematic satellite navigation with ground-penetrating radar surveys  

Technology Transfer Automated Retrieval System (TEKTRAN)

Precision agriculture, environmental mapping, and construction benefit from subsurface imaging by revealing the spatial variability of underground features. Features surveyed of agricultural interest are bedrock depth, soil horizon thicknesses, and buried–object features such as drainage pipe. For t...

161

Prospects for galactic astronomy from Pan-STARRS and other planned ground-based surveys  

NASA Astrophysics Data System (ADS)

The Pan-STARRS project is proceeding in two phases; PS1 is a single aperture system that has been deployed on Haleakala, Maui and will become operational at the end of 2006. PS4 is a 4-aperture system that will be deployed on Mauna Kea and which is planned to become operational in 2010. The Pan-STARRS telescopes feature 1.4 giga-pixel cameras that cover a massive 7 square degree field of view, and have low noise and rapid read-out that will allow them to survey the sky in a range of pass-bands from 400-1000nm at an unprecedented rate and depth. The Pan-STARRS PS1 3-pi survey will revolutionize galactic astronomy. It will cover 3/4 of the entire sky; individual exposures will be able to detect sources to r-magnitude of approximately 23; and each patch of sky will be visited approximately 70 times over the 3 year lifetime of the survey. Even in the first year of the survey, this will result in high quality parallaxes, proper motions and high precision photometry. The advance over existing all-sky surveys will be truly dramatic, with astrometric precision of a few milli-arcsec (as compared to a few hundred mas) and with 1-percent photometry as a design requirement and even higher precision as a realistic goal. PS4 will provide even greater astrometric precision --- by virtue of the better seeing on Mauna-Kea --- and will sample fainter and deeper, as will other planned surveys such as LSST. These surveys will have performance orders of magnitude higher than existing surveys, though ultimately they will in turn be eclipsed by future planned space missions such as GAIA.

Kaiser, N.

2006-08-01

162

Survey of modeling, planning, and ground verification of space robotic systems  

NASA Astrophysics Data System (ADS)

Space robotic systems are expected to play an increasingly important role in future space activities. Nevertheless, dynamics modeling and motion planning of a space robot are much more complex than those of a fixed-base robot, due to the dynamic coupling between the manipulator and its base. On the other hand, in order to assure the success of on-orbital missions, many experiments are required to verify the key algorithms on the ground before the space robot is launched. In this paper, the main research achievements on dynamics modeling, path planning, and ground verification are reviewed, and future studies are recommended. Firstly, we summarize the essential modeling concepts, and deduce the kinematics and dynamics equations of a space robot. Secondly, the main motion planning approaches are discussed. Then, different ground verification systems, including the air-bearing table, neutral buoyancy, airplane flying, free-falling motion, suspension system, and hybrid system, are introduced. Finally, the future research trends are forecasted.

Xu, Wenfu; Liang, Bin; Xu, Yangsheng

2011-06-01

163

Processing the ground vibration signal produced by debris flows: the methods of amplitude and impulses compared  

NASA Astrophysics Data System (ADS)

Ground vibration sensors have been increasingly used and tested, during the last few years, as devices to monitor debris flows and they have also been proposed as one of the more reliable devices for the design of debris flow warning systems. The need to process the output of ground vibration sensors, to diminish the amount of data to be recorded, is usually due to the reduced storing capabilities and the limited power supply, normally provided by solar panels, available in the high mountain environment. There are different methods that can be found in literature to process the ground vibration signal produced by debris flows. In this paper we will discuss the two most commonly employed: the method of impulses and the method of amplitude. These two methods of data processing are analyzed describing their origin and their use, presenting examples of applications and their main advantages and shortcomings. The two methods are then applied to process the ground vibration raw data produced by a debris flow occurred in the Rebaixader Torrent (Spanish Pyrenees) in 2012. The results of this work will provide means for decision to researchers and technicians who find themselves facing the task of designing a debris flow monitoring installation or a debris flow warning equipment based on the use of ground vibration detectors.

Arattano, M.; Abancó, C.; Coviello, V.; Hürlimann, M.

2014-12-01

164

WAVEFRONT RECONSTRUCTION METHODS FOR ADAPTIVE OPTICS SYSTEMS ON GROUND-BASED TELESCOPES  

E-print Network

WAVEFRONT RECONSTRUCTION METHODS FOR ADAPTIVE OPTICS SYSTEMS ON GROUND-BASED TELESCOPES JOHNATHAN M the refractive blurring of images. Adaptive optics systems seek to remove phase error from incoming wavefronts methods, and comparisons are made. Keywords: adaptive optics, wavefront reconstruction, minimum variance

Bardsley, John

165

Simulations of Strong Ground Motion in the Los Angeles Basin Using the Spectral-Element Method  

Microsoft Academic Search

We use the spectral-element method (SEM) to simulate strong ground motion in the Los Angeles basin. Our basin velocity model was constructed using sonic log and stacking velocity information provided by oil industry sources. The method includes effects due to attenuation, topography and bathymetry. The basin model is embedded into the regional model of Hauksson (2000). Our mesh honors the

D. Komatitsch; Q. Liu; J. Tromp; P. Suess; J. Shaw

2003-01-01

166

Phenomenography and Grounded Theory as Research Methods in Computing Education Research Field  

ERIC Educational Resources Information Center

This paper discusses two qualitative research methods, phenomenography and grounded theory. We introduce both methods' data collection and analysis processes and the type or results you may get at the end by using examples from computing education research. We highlight some of the similarities and differences between the aim, data collection and…

Kinnunen, Paivi; Simon, Beth

2012-01-01

167

A SCREENING METHOD FOR THE DETERMINATION OF GLYPHOSATE IN GROUND WATER  

Microsoft Academic Search

A rugged dual column LC method was developed for the screening analysis of glyphosate in ground water. Analysis was based on a previously described pre-column fluorescence derivatization procedure. The method employed a short pre-column cartridge and a conventional reverse phase analytical column. Method precision for the screening assay was acceptable (13.1% RSD). The method was applied to a large set

C. M. Sparacino; F. K. Thomas

2002-01-01

168

Comparison of Three Tobacco Survey Methods with College Students: A Case Study  

ERIC Educational Resources Information Center

The goals of this case study were to: (1) determine the efficiency and effectiveness of three survey methods--postal mail survey, web-based survey, and random in-class administration survey--in assessing tobacco-related attitudes and behaviors among college students and (2) compare the response rate and procedures of these three methods. There was…

James, Delores C. S.; Chen, W. William; Sheu, Jiunn-Jye

2005-01-01

169

Three-dimensional resistivity modelling of grounded electrical-source airborne transient electromagnetic (GREATEM) survey data from the Nojima Fault, Awaji Island, south-east Japan  

NASA Astrophysics Data System (ADS)

An airborne electromagnetic (AEM) survey using the grounded electrical-source airborne transient electromagnetic (GREATEM) system was conducted over the Nojima Fault on Awaji Island, south-east Japan, to assess GREATEM survey applicability for studying coastal areas with complex topographic features. To obtain high-quality data with an optimised signal-to-noise ratio, a series of data processing techniques was used to acquire the final transient response curves from the field survey data. The 1D inversion results were feasible in that the horizontal resistivity contrast was not much higher than the true contrast, but they were not reasonable in that the horizontal resistivity values were greatly changed. To circumvent this problem, we performed numerical forward modelling using a finite-difference staggered-grid method (Fomenko and Mogi, 2002) adding a finite-length electrical dipole source routine to generate a three-dimensional (3D) resistivity structure model from GREATEM survey data of the Nojima Fault area. The 3D model was based on an initial model consisting of two adjacent onshore and offshore layers of different conductivity such that, a highly conductive sea of depth (10-40 m) is placed on top of a uniform half-space, assuming the presence of topographic features on the inland side. We examined the fit of the magnetic transient responses between field data and 3D forward-model computed data, the latter were convolved with the measured system response of the corresponding dataset. The inverted 3D resistivity structures showed that the GREATEM system has the capability to map underground resistivity structures as deep as 500 m onshore and offshore. The GREATEM survey delineated how seawater intrudes on the landside of the fault and indicated that the fault is a barrier to seawater invasion.

Allah, Sabry Abd; Mogi, Toru; Ito, Hisatoshi; Jymori, Akira; Yuuki, Youichi; Fomenko, Elena; Kiho, Kenzo; Kaieda, Hideshi; Suzuki, Koichi; Tsukuda, Kazuhiro

2014-08-01

170

A new method of combination of electroosmosis, vacuum and surcharge preloading for soft ground improvement  

NASA Astrophysics Data System (ADS)

As a rapid and effective ground improvement method is urgently required for the booming land reclamation in China's coastal area, this study proposes a new combined method of electroosmosis, vacuum preloading and surcharge preloading. A new type of electrical prefabricated vertical drain (ePVD) and a new electroosmotic drainage system are suggested to allow the application of the new method. This combined method is then field-tested and compared with the conventional vacuum combined with surcharge preloading method. The monitoring and foundation test results show that the new method induces a settlement 20% larger than that of the conventional vacuum combined with surcharge preloading method in the same treatment period, and saves approximately half of the treatment time compared with the vacuum combined with surcharge preloading method according to the finite element prediction of the settlement. The proposed method also increases the vane shear strength of the soil significantly. The bearing capacity of the ground improved by use of the new proposed method raises 118%. In comparison, there is only a 75% rise when using the vacuum combined with surcharge preloading method during the same reinforcement period. All results indicate that the proposed combined method is effective and suitable for reinforcing the soft clay ground. Besides, the voltage applied between the anode and cathode increases exponentially versus treatment time when the output current of power supplies is kept constant. Most of the voltage potential in electroosmosis is lost at electrodes, leaving smaller than 50% of the voltage to be effectively transmitted into the soil.

Liu, Han-long; Cui, Yun-liang; Shen, Yang; Ding, Xuan-ming

2014-08-01

171

SURVEY  

Microsoft Academic Search

ABSTRACTBackground: Experiencing ethical problems requires both ethically problematic situations and ethical sensitivity. Ethically problematic treatment decisions are distressing and might reflect health care quality problems. Whether all physicians actually experience ethical problems, what these problems are and how they vary according to physician age, gender and work sector are largely unknown.Methods: A mail survey of all non-retired physicians licensed in

SAMULI I. SAARNI; PIITU PARMANNE; RITVA HALILA

2008-01-01

172

Application of ground-penetrating radar methods in determining hydrogeologic conditions in a karst area, west-central Florida  

USGS Publications Warehouse

Ground-penetrating radar (GPR) is useful as a surface geophysical method for exploring geology and subsurface features in karst settings. Interpretation of GPR data was used to infer lithology and hydrogeologic conditions in west-central Florida. This study demonstrates how GPR methods can be used to investigate the hydrogeology of an area. GPR transmits radio- frequency electromagnetic waves into the ground and receives reflected energy waves from subsurface interfaces. Subsurface profiles showing sediment thickness, depth to water table and clay beds, karst development, buried objects, and lake-bottom structure were produced from GPR traverses obtained during December 1987 and March 1990 in Pinellas, Hillsborough, and Hardee Counties in west-central Florida. Performance of the GPR method is site specific, and data collected are principally affected by the sediment and pore fluids, conductances and dielectric constants. Effective exploration depths of the GPR surveys through predominately unsaturated and saturated sand and clay sediments at five study sites ranged from a few feet to greater than 50 feet below land surface. Exploration depths were limited when high conductivity clay was encountered, whereas greater exploration depths were possible in material composed of sand. Application of GPR is useful in profiling subsurface conditions, but proper interpretation depends upon the user's knowledge of the equipment and the local hydrogeological setting, as well as the ability to interpret the graphic profile.

Barr, G.L.

1993-01-01

173

Aeroelastic analysis and ground vibration survey of the NASA, Grumman American Yankee modified for spin testing  

NASA Technical Reports Server (NTRS)

A complete ground vibration and aeroelastic analysis was made of a modified version of the Grumman American Yankee. The aircraft had been modified for four empennage configurations, a wing boom was added, a spin chute installed and provisions included for large masses in the wing tip to vary the lateral and directional inertia. Other minor changes were made which have much less influence on the flutter and vibrations. Neither static divergence nor aileron reversal was considered since the wing structure was not sufficiently changed to affect its static aeroelastic qualities. The aircraft was found to be free from flutter in all of the normal modes explored in the ground shake test. The analysis demonstrated freedom from flutter up to 214 miles per hour.

Kroeger, R. A.

1977-01-01

174

Survey of ground state neutron Spectroscopic Factors from Li to Cr isotopes  

E-print Network

The ground state neutron spectroscopic factors for 80 nuclei ranging in Z from 3 to 24 have been extracted by analyzing the past measurements of the angular distributions from (d,p) and (p,d) reactions. We demonstrate an approach that provides systematic and consistent values with minimum assumptions. For the 61 nuclei that have been described by large-basis shell-model calculations, most experimental spectroscopic factors are reproduced to within 20%.

M. B. Tsang; Jenny Lee; W. G. Lynch

2005-09-09

175

Ilntmduction to Detection and Survey Methods William I. Zielinski' and Thomas E. Kucera2  

E-print Network

Ilntmduction to Detection and Survey Methods William I. Zielinski' and Thomas E. Kucera2 Background to Detection and SurveyMethods Chapter 1 Zielinski and Kucera States (Biodiversity Legal Foundation 1994a, 1994

Standiford, Richard B.

176

Movement and fate of creosote waste in ground water, Pensacola, Florida; U.S. Geological Survey toxic waste-ground-water contamination program  

USGS Publications Warehouse

Ground- and surface-water contamination by pesticides used in the wood-preserving industry is widespread in the United States. Pine poles were treated with wood preservatives from 1902 to 1981 at a creosote works near Pensacola, Florida. Diesel fuel, creosote, and pentachlorophenol were discharged to two unlined impoundments that had a direct hydraulic connection to the sand-and-gravel aquifer. Evidence of wood-preserving waste contamination appears to be confined to the upper 30 meters of the aquifer. The waste plume extends downgradient approximately 300 meters south toward Pensacola Bay. In 1983, the creosote works site was selected by the U.S. Geological Survey's Office of Hazardous Waste Hydrology as a national research demonstration area to apply the latest techniques for characterizing hazardous waste problems. The multidisciplinary research effort is aimed at studying processes that affect the occurrence, transport, transformations, and fate of the toxic contaminants associated with wood preservatives in the environment. Clusters of two to five wells were constructed at different depths at nine sites to define the depth of contamination. Research studies are investigating sorption, dispersion, dilution, chemical reactions, bacterially mediated transformations, quality assurance, plume hydrodynamics, and the ultimate fate of these complex organic wastes.

Mattraw, Harold C., Jr.,(Edited By); Franks, Bernard J.

1986-01-01

177

The IMACS Cluster Building Survey. I. Description of the Survey and Analysis Methods  

NASA Technical Reports Server (NTRS)

The IMACS Cluster Building Survey uses the wide field spectroscopic capabilities of the IMACS spectrograph on the 6.5 m Baade Telescope to survey the large-scale environment surrounding rich intermediate-redshift clusters of galaxies. The goal is to understand the processes which may be transforming star-forming field galaxies into quiescent cluster members as groups and individual galaxies fall into the cluster from the surrounding supercluster. This first paper describes the survey: the data taking and reduction methods. We provide new calibrations of star formation rates (SFRs) derived from optical and infrared spectroscopy and photometry. We demonstrate that there is a tight relation between the observed SFR per unit B luminosity, and the ratio of the extinctions of the stellar continuum and the optical emission lines.With this, we can obtain accurate extinction-corrected colors of galaxies. Using these colors as well as other spectral measures, we determine new criteria for the existence of ongoing and recent starbursts in galaxies.

Oemler Jr., Augustus; Dressler, Alan; Gladders, Michael G.; Rigby, Jane R.; Bai, Lei; Kelson, Daniel; Villanueva, Edward; Fritz, Jacopo; Rieke, George; Poggianti, Bianca M.; Vulcani, Benedetta

2013-01-01

178

THE IMACS CLUSTER BUILDING SURVEY. I. DESCRIPTION OF THE SURVEY AND ANALYSIS METHODS  

SciTech Connect

The IMACS Cluster Building Survey uses the wide field spectroscopic capabilities of the IMACS spectrograph on the 6.5 m Baade Telescope to survey the large-scale environment surrounding rich intermediate-redshift clusters of galaxies. The goal is to understand the processes which may be transforming star-forming field galaxies into quiescent cluster members as groups and individual galaxies fall into the cluster from the surrounding supercluster. This first paper describes the survey: the data taking and reduction methods. We provide new calibrations of star formation rates (SFRs) derived from optical and infrared spectroscopy and photometry. We demonstrate that there is a tight relation between the observed SFR per unit B luminosity, and the ratio of the extinctions of the stellar continuum and the optical emission lines. With this, we can obtain accurate extinction-corrected colors of galaxies. Using these colors as well as other spectral measures, we determine new criteria for the existence of ongoing and recent starbursts in galaxies.

Oemler, Augustus Jr.; Dressler, Alan; Kelson, Daniel; Villanueva, Edward [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101-1292 (United States); Gladders, Michael G. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Rigby, Jane R. [Observational Cosmology Lab, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bai Lei [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Fritz, Jacopo [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Rieke, George [Steward Observatory, University of Arizona, Tucson, AZ 8572 (United States); Poggianti, Bianca M.; Vulcani, Benedetta, E-mail: oemler@obs.carnegiescience.edu [INAF-Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy)

2013-06-10

179

Survey of NASA V and V Processes/Methods  

NASA Technical Reports Server (NTRS)

The purpose of this report is to describe current NASA Verification and Validation (V&V) techniques and to explain how these techniques are applicable to 2nd Generation RLV Integrated Vehicle Health Management (IVHM) software. It also contains recommendations for special V&V requirements for IVHM. This report is divided into the following three sections: 1) Survey - Current NASA V&V Processes/Methods; 2) Applicability of NASA V&V to 2nd Generation RLV IVHM; and 3) Special 2nd Generation RLV IVHM V&V Requirements.

Pecheur, Charles; Nelson, Stacy

2002-01-01

180

Apparatus for and method of testing an electrical ground fault circuit interrupt device  

DOEpatents

An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined. 17 figs.

Andrews, L.B.

1998-08-18

181

Apparatus for and method of testing an electrical ground fault circuit interrupt device  

DOEpatents

An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined.

Andrews, Lowell B. (2181-13th Ave. SW., Largo, FL 34640)

1998-01-01

182

Using Survey Methods for Design and Evaluation in Child Computer Interaction  

E-print Network

Using Survey Methods for Design and Evaluation in Child Computer Interaction Janet Read Child@aol.com ABSTRACT This paper begins with a review of some of the current literature on the use of survey methods with children. It then presents four known concerns with using survey methods and reflects on how these may

183

Investigating the Local and High Redshift Universe With Deep Survey Data and Ground-Based Spectroscopy  

NASA Astrophysics Data System (ADS)

Large multiwavelength surveys are now driving the frontiers of astronomical research. I describe results from my work using data from two large astronomical surveys: the Cosmic Evolution Survey (COSMOS), which has obtained deep photometric and spectroscopic data on two square degrees of the sky using many of the most powerful telescopes in the world, and the WFC3 Infrared Spectroscopic Parallels (WISP) Survey, which uses the highly sensitive slitless spectroscopic capability of the Hubble Space Telescope Wide Field Camera 3 to detect star-forming galaxies over most of the universe's history. First I describe my work on the evolution of the high-redshift quasar luminosity function, an important observational quantity constraining the growth of the supermassive black holes in the early universe. I show that the number density of faint quasars declines rapidly above z ˜ 3. This result is discussed in the context of cosmic reionization and the coevolution of galaxies and their central black holes. Next I present results of a multi-year campaign of near-infrared spectroscopy with FIRE, a world-class near-infrared spectrometer on the Magellan Baade 6.5 meter telescope in Chile, targeting emission-line galaxies at z ˜ 2 discovered with the Hubble Space Telescope. Our results showed that the typical emission-line galaxy at this redshift has low-metallicity, low dust obscuration, high ionization parameter, and little evidence for significant active galactic nucleus (AGN) contribution to the emission lines. We also find evidence that high redshift star-forming galaxies have enhanced nitrogen abundances. This result has interesting implications for the nature of the star formation in such galaxies -- in particular, it could mean that a large fraction of such galaxies harbor substantial populations of Wolf-Rayet stars, which are massive, evolved stars ejecting large amounts of enriched matter into the interstellar medium. Finally, I will discuss the discovery of three distant, ultracool brown dwarfs in the WISP survey. These objects, larger than massive planets but smaller than dwarf stars, are very difficult to detect, but their numbers and distribution in our galaxy have profound implications for our understanding of the formation of low-mass stars and planets. The brown dwarfs were found in the WFC3 grism spectroscopy, where they were identified through their strong atmospheric absorption features of water and methane. A systematic search for such objects in all WISP fields yielded three in total, allowing statistical inferences to be made regarding their distribution and number density in the Milky Way.

Masters, Daniel Charles

184

Earthquake early warning: Concepts, methods and physical grounds Claudio Satriano a,c,n  

E-print Network

the availability of reliable predictions of size, location and time of an incoming earthquake would be required earthquake prediction is not currently possible [3,4]. Even if such predictions were availableEarthquake early warning: Concepts, methods and physical grounds Claudio Satriano a,c,n , Yih

Wu, Yih-Min

185

Application of the two-microphone method for in-situ ground impedance measurements  

E-print Network

For the prediction of the sound propagation, the surface impedance of outdoor grounds is an important parameter different proposed measurement geometries and a number of absorber parameter combinations. While this method, the following equipment was used: For test site 1, the sound source consisted of a Philips EJ 1030 compression

Vormann, Matthias

186

Misused and missed use — Grounded Theory and Objective Hermeneutics as methods for research in industrial marketing  

Microsoft Academic Search

Since qualitative research methods have always found strong representation within sociology it is warranted to look at the sociological discussion in order to challenge and enrich qualitative research in industrial marketing. With this mission in mind, we discuss two sociological concepts that constitute influential schools within the German-speaking sociology of language community: Grounded Theory and Objective Hermeneutics. The analysis of

Stephan M. Wagner; Peter Lukassen; Matthias Mahlendorf

2010-01-01

187

Using Popular Media and a Collaborative Approach to Teaching Grounded Theory Research Methods  

ERIC Educational Resources Information Center

Popular movies were used in a doctoral-level qualitative research methods course as a way to help students learn about how to collect and analyze qualitative observational data in order to develop a grounded theory. The course was designed in such a way that collaboration was central to the generation of knowledge. Using media depictions had the…

Creamer, Elizabeth G.; Ghoston, Michelle R.; Drape, Tiffany; Ruff, Chloe; Mukuni, Joseph

2012-01-01

188

GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?  

EPA Science Inventory

After years of research and many publications, the question still remains: What is the best method to collect representative ground water samples from monitoring wells? Numerous systems and devices are currently available for obtaining both multi-level samples as well as traditi...

189

A Method to Shorten the Size of Amplifiers Using Vertically Periodic Defected Ground Structure  

E-print Network

-pass properties [1-5]. Another representative features of the periodic structures are the increased slow-wave by VPDGS provides 3 times higher slow­wave factor than standard microstrip line. Due to the increased slowA Method to Shorten the Size of Amplifiers Using Vertically Periodic Defected Ground Structure Jong

Nam, Sangwook

190

An efficient method for deriving reliable field scale soil water contents from the GPR ground wave  

NASA Astrophysics Data System (ADS)

Over the last decade, significant advancements have been made for measuring soil water content across several spatial scales. Nevertheless, quantifying soil water content at the field scale (some ten to several hundred meters) still is a challenge. Ground-Penetrating Radar (GPR) is a non-invasive electromagnetic geophysical method which is sensitive to variations of soil water content. Especially the GPR direct ground wave signal has repeatedly been employed for calculating near-surface soil water contents. However, traditional evaluation methods of common offset GPR ground wave datasets are typically hampered by insufficient time zero calibration. After analyzing common pitfalls, we here present a novel calibration method for deriving reliable field scale soil water contents from evaluating the GPR direct ground wave signal. Our approach is based on employing independent information of two separate measurement channels of our multichannel GPR system. This method has been evaluated for center frequencies of 200 & 400 MHz. Employing antenna separations between 1 and 2 meters, the attainable accuracy is in the same range as can be achieved by point measurements with Time-Domain Reflectometry (TDR). The new possibilities are demonstrated by interpreting observed multiscale variations in the soil water content field at a semi-vegetated desert site in terms of the different generating processes.

Klenk, Patrick; Qin, Yanfang; Zhou, Kefa; Roth, Kurt

2013-04-01

191

Survey on maternal mortality in Swaziland using the sisterhood method.  

PubMed

Monitoring and evaluating maternal mortality in African countries is impossible without specific and reliable data and indicators. This study of maternal mortality using the 'Sisterhood Method' was undertaken in Swaziland. The crude data on 'sisterhood mortality' were obtained from the 1993-94 Multi-Purpose Household Survey carried out by the Central Statistics Office and Ministry of Health of Swaziland. A total fertility rate of 6.36, as given in the 1986 Swaziland census, was used in estimating these indicators. Prior to this study, the maternal mortality rate (MMR) in Swaziland (based only on health facility data) was considered to lie within the range of 107-125 maternal deaths per 100 000 live births. Use of the 'Sisterhood Method' allowed a more precise estimate of maternal mortality for the general population of Swaziland. The study revealed the estimated MMR to be 229 and the life-time risk of maternal death to be 1 in 69. These values were most probably stable throughout the 6- to 7-year period before the survey. PMID:12060310

Lech, Medard M; Zwane, Amos

2002-04-01

192

Methods for solving reasoning problems in abstract argumentation – A survey  

PubMed Central

Within the last decade, abstract argumentation has emerged as a central field in Artificial Intelligence. Besides providing a core formalism for many advanced argumentation systems, abstract argumentation has also served to capture several non-monotonic logics and other AI related principles. Although the idea of abstract argumentation is appealingly simple, several reasoning problems in this formalism exhibit high computational complexity. This calls for advanced techniques when it comes to implementation issues, a challenge which has been recently faced from different angles. In this survey, we give an overview on different methods for solving reasoning problems in abstract argumentation and compare their particular features. Moreover, we highlight available state-of-the-art systems for abstract argumentation, which put these methods to practice. PMID:25737590

Charwat, Günther; Dvo?ák, Wolfgang; Gaggl, Sarah A.; Wallner, Johannes P.; Woltran, Stefan

2015-01-01

193

Estimation of ground and excited state dipole moments of Oil Red O by solvatochromic shift methods  

NASA Astrophysics Data System (ADS)

Absorption and fluorescence spectra of Oil Red O (abbreviated as ORO) are recorded in various solvents with different polarity in the range of 250-900 nm, at room temperature. The solvatochromic shift methods have been used to determine the ground state (?g) and excited state (?e) dipole moments depending on dielectric constant and refractive index functions. It is observed that fluorescence spectra show positive solvatochromism whereas absorption spectra do not indicates sensitive behavior to solvent polarity. Excited state dipole moment is found as higher than those of ground state for all of the used methods and it is attributed to more polar excited state of ORO. Theoretical ?g has been determined by quantum chemical calculations using DFT and semi empirical methods. HOMO, LUMO, molecular electrostatic potential (MEP) and solvent accessible surface of ORO are calculated by using DFT-B3LYP method.

S?d?r, ?sa; Gülseven S?d?r, Yadigar

2015-01-01

194

Ground magnetometer survey in the Valley of Ten Thousand Smokes, Alaska. M.S. Thesis  

NASA Technical Reports Server (NTRS)

A reconnaissance magnetometer survey was conducted with both total- and vertical-field magnetometers. The large, sharp, narrow total magnetic anomalies observed over a zone of relict fumaroles in Broken Mountain Valley showed spectacular agreement with the surficial geology. Such a correlation is a strong indication that accumulations of magnetic minerals have been preserved along these fissure vents at shallow depths. Since large magnetic anomalies were measured near fumarolic markings along all of the traverses, it is proposed that the retention of sublimates along fumarolic vents is common throughout the Valley. The generally concentric contours of the vertical magnetic anomaly at the head of the Valley suggest that the dome of Novarupta is merely the surficial expression of a very massive conical-shaped intrusive centered just northeast of the dome. The magnetometer survey indicates that the pyroclastics in the Valley may be over 150 meters thick. Such an estimate is compatible with the volume of eruptive material needed to compensate for the subsidence surrounding Novarupta as well as a sizable amount of other regional subsidence.

Trible, M. C.

1972-01-01

195

Occurrence of selected radionuclides in ground water used for drinking water in the United States; a reconnaissance survey, 1998  

USGS Publications Warehouse

The U.S. Geological Survey, in collaboration with the U.S. Environmental Protection Agency, the American Water Works Association, and the American Water Works Service Company, completed a targeted national reconnaissance survey of selected radionuclides in public ground-water supplies. Radionuclides analyzed included radium-224 (Ra-224), radium-226 (Ra-226), radium-228 (Ra-228), polonium-210 (Po-210) and lead-210 (Pb-210).This U.S. Geological Survey reconnaissance survey focused intentionally on areas with known or suspected elevated concentrations of radium in ground water to determine if Ra-224 was also present in the areas where other isotopes of radium had previously been detected and to determine the co-occurrence characteristics of the three radium isotopes (Ra-224, Ra-226, and Ra-228) in those areas. Ninety-nine raw-water samples (before water treatment) were collected once over a 6-month period in 1998 and 1999 from wells (94 of which are used for public drinking water) in 27 States and 8 physiographic provinces. Twenty-one of the 99 samples exceeded the current U.S. Environmental Protection Agency drinking-water maximum contaminant level of 5 picocuries per liter (pCi/L) for combined radium (Ra-226 + Ra-228). Concentrations of Ra-224 were reported to exceed 1 pCi/L in 30 percent of the samples collected, with a maximum concentration of 73.6 pCi/L measured in water from a nontransient, noncommunity, public-supply well in Maryland. Radium-224 concentrations generally were higher than those of the other isotopes of radium. About 5 percent of the samples contained concentrations of Ra-224 greater than 10 pCi/L, whereas only 2 percent exceeded 10 pCi/L for either Ra-226 or Ra-228. Concentrations of Ra-226 greater than 1 pCi/L were reported in 33 percent of the samples, with a maximum concentration of 16.9 pCi/L measured in water from a public-supply well in Iowa. Concentrations of Ra-228 greater than 1 pCi/L were reported in 22 samples, with a maximum concentration of 72.3 pCi/L measured in water from a non-transient, noncommunity, public-supply well in Maryland.Radium-224, which is a decay product of Ra-228 in the Th-232 decay series, was significantly correlated with Ra-228 (Spearman?s rank correlation coefficient ?r? equals 0.82) and to a lesser degree with Ra-226 (r equals 0.69), which is an isotope in the U-238 decay series. The rank correlation coefficient between Ra-226 and Ra-228 was 0.63. The high correlation between Ra-224 and Ra-228 concentrations and the corresponding isotopic ratios of the two (about 1:1 in 90 percent of the samples) indicates that the two radionuclides occur in approximately equal concentrations in most ground water sampled. Thus, Ra-228 can be considered as a reasonable proxy indicator for the occurrence of Ra-224 in ground water.The maximum concentration of Po-210 was 4.85 pCi/L and exceeded 1 pCi/L in only two samples. The maximum concentration of Pb-210 was 4.14 pCi/L, and about 10 percent of the samples exceeded 1 pCi/L. Areas with known, or suspected, elevated concentrations of polonium and lead were not targeted in this survey.Three major implications are drawn for future radionuclide monitoring on the basis of this information: (1) grossalpha particle analyses of ground water should be done within about 48?72 hours after collection to determine the presence of the short-lived, alpha-particle emitting isotopes, such as Ra-224, which was detected in elevated concentrations in many of the samples collected for this survey; (2) the isotope ratios of Ra-224 to Ra-228 in ground water are variable on a national scale, but the two radioisotopes generally occur in ratios near 1:1, therefore, the more commonly measured Ra-228 can be used as an indicator of Ra-224 occurrence for some general purposes other than compliance; and (3) the isotopic ratios of Ra-226 to Ra-228 were less than 3:2 in many samples. These ratios corroborate results of previous studies that have shown the presence of Ra-228

Focazio, Michael J.; Szabo, Zoltan; Kraemer, Thomas F.; Mullin, Ann H.; Barringer, Thomas H.; dePaul, Vincent T.

2001-01-01

196

Surveying abandoned mine shafts with Remote Radio Transmitter EM methods and Selfpotential  

NASA Astrophysics Data System (ADS)

Abandoned near subsurface mining constructions from the 19th and early 20th century in urbanized areas placed upon former ore mines near the city of Aachen (Germany), as well as in many other regions of the world, provide hazardous risks concerning possible collapses. In many cases, the exact locations of such constructions are not known anymore. For instance, to map covered shafts of one meter diameter on large survey areas, high resolution methods with rapid measurement progress are necessary. Enhanced developments of the traditional Very Low Frequency (VLF) technique such as VLF-gradient and Radiomagnetotellurics (RMT) fulfill these requirements. Continuous ground-contactless VLF-gradient survey quickly provides maps indicating the lateral electric resistivity heterogeneity distribution. Inversions of RMT data provide 2D-resistivity-depth sections and also the interpretation of Self-Potential data gives information about the nature of the VLF-gradient anomalies. The successful combination of the three methods for detecting mineshafts near to the city if Aachen is presented for both an electromagnetic undisturbed and noisy location.

Bosch, F. P.; Gurk, M.

2009-04-01

197

Single-beam acoustic ground discrimination of shallow water habitats: 50 kHz or 200 kHz frequency survey?  

Microsoft Academic Search

The single-beam acoustic ground discrimination system QTC View, Series V, was used in the Bay of Cadiz, Southwest Spain, for the identification and mapping of the bottom acoustic diversity. The acoustic data were obtained through two successive surveys, each conducted with one of the following echo sounder frequencies: 50kHz and 200kHz. The performance of each survey frequency for the identification

Rosa Freitas; Ana Maria Rodrigues; Edward Morris; Jose Lucas Perez-Llorens; Victor Quintino

2008-01-01

198

Analytic Perturbation Method for Estimating Ground Flash Fraction from Satellite Lightning Observations  

NASA Technical Reports Server (NTRS)

An analytic perturbation method is introduced for estimating the lightning ground flash fraction in a set of N lightning flashes observed by a satellite lightning mapper. The value of N is large, typically in the thousands, and the observations consist of the maximum optical group area produced by each flash. The method is tested using simulated observations that are based on Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) data. National Lightning Detection NetworkTM (NLDN) data is used to determine the flash-type (ground or cloud) of the satellite-observed flashes, and provides the ground flash fraction truth for the simulation runs. It is found that the mean ground flash fraction retrieval errors are below 0.04 across the full range 0-1 under certain simulation conditions. In general, it is demonstrated that the retrieval errors depend on many factors (i.e., the number, N, of satellite observations, the magnitude of random and systematic measurement errors, and the number of samples used to form certain climate distributions employed in the model).

Koshak, William; Solakiewicz, Richard

2013-01-01

199

Schonlau M., Van Soest A, Kapteyn A, Are `Webographic' or attitudinal questions useful for adjusting estimates from Web surveys using propensity scoring? Survey Research Methods,  

E-print Network

for adjusting estimates from Web surveys using propensity scoring? Survey Research Methods, 2007, 1 (3), 155-163. Are `Webographic' or attitudinal questions useful for adjusting estimates from Web surveys using propensity scoring? Abstract Inference from Web surveys may be affected by non-random selection of Web survey participants. One

Schonlau, Matt

200

A double-observer method to estimate detection rate during aerial waterfowl surveys  

USGS Publications Warehouse

We evaluated double-observer methods for aerial surveys as a means to adjust counts of waterfowl for incomplete detection. We conducted our study in eastern Canada and the northeast United States utilizing 3 aerial-survey crews flying 3 different types of fixed-wing aircraft. We reconciled counts of front- and rear-seat observers immediately following an observation by the rear-seat observer (i.e., on-the-fly reconciliation). We evaluated 6 a priori models containing a combination of several factors thought to influence detection probability including observer, seat position, aircraft type, and group size. We analyzed data for American black ducks (Anas rubripes) and mallards (A. platyrhynchos), which are among the most abundant duck species in this region. The best-supported model for both black ducks and mallards included observer effects. Sample sizes of black ducks were sufficient to estimate observer-specific detection rates for each crew. Estimated detection rates for black ducks were 0.62 (SE = 0.10), 0.63 (SE = 0.06), and 0.74 (SE = 0.07) for pilot-observers, 0.61 (SE = 0.08), 0.62 (SE = 0.06), and 0.81 (SE = 0.07) for other front-seat observers, and 0.43 (SE = 0.05), 0.58 (SE = 0.06), and 0.73 (SE = 0.04) for rear-seat observers. For mallards, sample sizes were adequate to generate stable maximum-likelihood estimates of observer-specific detection rates for only one aerial crew. Estimated observer-specific detection rates for that crew were 0.84 (SE = 0.04) for the pilot-observer, 0.74 (SE = 0.05) for the other front-seat observer, and 0.47 (SE = 0.03) for the rear-seat observer. Estimated observer detection rates were confounded by the position of the seat occupied by an observer, because observers did not switch seats, and by land-cover because vegetation and landform varied among crew areas. Double-observer methods with on-the-fly reconciliation, although not without challenges, offer one viable option to account for detection bias in aerial waterfowl surveys where birds are distributed at low density in remote areas that are inaccessible by ground crews. Double-observer methods, however, estimate only detection rate of animals that are potentially observable given the survey method applied. Auxiliary data and methods must be considered to estimate overall detection rate.

Koneff, M.D.; Royle, J.A.; Otto, M.C.; Wortham, J.S.; Bidwell, J.K.

2008-01-01

201

An Evaluation of Respondent Selection Methods for Household Mail Surveys  

Microsoft Academic Search

Mail surveys are a staple of the survey industry; however, they are rarely used in surveys of the general population. The problem is twofold: (1) lack of a complete sampling frame of households and (2) difficulties with ensuring random selection of a respondent within the household. However, advances in electronic record keeping, such as the U.S. Postal Service Delivery Sequence

Michael P. Battaglia; Michael W. Link; Martin R. Frankel; Larry Osborn; Ali H. Mokdad

2008-01-01

202

Numerical Analysis of Grounding Resistance of Buried Thin Wires by the FDTD Method  

Microsoft Academic Search

For the analysis of grounding resistance with the finite-difference time-domain (FDTD) method for solving Maxwell's equations, an equivalent radius of a naked thin wire in a lossy medium is derived by means of the static-field approximation proposed for derivation of that of an aerial thin wire. It is 0.23 times the side of cells employed, which is the same as

Yoshihiro Baba; Naoto Nagaoka; Akihiro Ametani

203

An Automated Method for Large-Scale, Ground-Based City Model Acquisition  

Microsoft Academic Search

In this paper, we describe an automated method for fast, ground-based acquisition of large-scale 3D city models. Our experimental set up consists of a truck equipped with one camera and two fast, inexpensive 2D laser scanners, being driven on city streets under normal traffic conditions. One scanner is mounted vertically to capture building facades, and the other one is mounted

Christian Früh; Avideh Zakhor

2004-01-01

204

Simulations of Ground Motion in the Los Angeles Basin Based upon the Spectral-Element Method  

Microsoft Academic Search

We use the spectral-element method to simulate ground motion gener- ated by two recent and well-recorded small earthquakes in the Los Angeles basin. Simulations are performed using a new sedimentary basin model that is constrained by hundreds of petroleum-industry well logs and more than 20,000 km of seismic reflection profiles. The numerical simulations account for 3D variations of seismic- wave

Dimitri Komatitsch; Qinya Liu; Jeroen Tromp; Peter Suss; Christiane Stidham; John H. Shaw

2004-01-01

205

A new fabrication method for precision antenna reflectors for space flight and ground test  

NASA Technical Reports Server (NTRS)

Communications satellites are using increasingly higher frequencies that require increasingly precise antenna reflectors for use in space. Traditional industry fabrication methods for space antenna reflectors employ successive modeling techniques using high- and low-temperature molds for reflector face sheets and then a final fit-up of the completed honeycomb sandwich panel antenna reflector to a master pattern. However, as new missions are planned at much higher frequencies, greater accuracies will be necessary than are achievable using these present methods. A new approach for the fabrication of ground-test solid-surface antenna reflectors is to build a rigid support structure with an easy-to-machine surface. This surface is subsequently machined to the desired reflector contour and coated with a radio-frequency-reflective surface. This method was used to fabricate a 2.7-m-diameter ground-test antenna reflector to an accuracy of better than 0.013 mm (0.0005 in.) rms. A similar reflector for use on spacecraft would be constructed in a similar manner but with space-qualified materials. The design, analysis, and fabrication of the 2.7-m-diameter precision antenna reflector for antenna ground tests and the extension of this technology to precision, space-based antenna reflectors are described.

Sharp, G. Richard; Wanhainen, Joyce S.; Ketelsen, Dean A.

1991-01-01

206

The evaluation of a population based diffusion tensor image atlas using a ground truth method  

NASA Astrophysics Data System (ADS)

Purpose: Voxel based morphometry (VBM) is increasingly being used to detect diffusion tensor (DT) image abnormalities in patients for different pathologies. An important requisite for these VBM studies is the use of a high-dimensional, non-rigid coregistration technique, which is able to align both the spatial and the orientational information. Recent studies furthermore indicate that high-dimensional DT information should be included during coregistration for an optimal alignment. In this context, a population based DTI atlas is created that preserves the orientational DT information robustly and contains a minimal bias towards any specific individual data set. Methods: A ground truth evaluation method is developed using a single subject DT image that is deformed with 20 deformation fields. Thereafter, an atlas is constructed based on these 20 resulting images. Thereby, the non-rigid coregistration algorithm is based on a viscous fluid model and on mutual information. The fractional anisotropy (FA) maps as well as the DT elements are used as DT image information during the coregistration algorithm, in order to minimize the orientational alignment inaccuracies. Results: The population based DT atlas is compared with the ground truth image using accuracy and precision measures of spatial and orientational dependent metrics. Results indicate that the population based atlas preserves the orientational information in a robust way. Conclusion: A subject independent population based DT atlas is constructed and evaluated with a ground truth method. This atlas contains all available orientational information and can be used in future VBM studies as a reference system.

Van Hecke, Wim; Leemans, Alexander; D'Agostino, Emiliano; De Backer, Steve; Vandervliet, Evert; Parizel, Paul M.; Sijbers, Jan

2008-03-01

207

Tests of methods to improve response to physician surveys  

Microsoft Academic Search

123 Response rates to the National Ambulatory Medical Care Survey (NAMCS), a leading survey of visits to office-based physicians, while larger than most physician surveys have nevertheless been declining since 1985 (from ~75-65%). Research had shown that some improvements in response rates with physicians were found when monetary incentives were employed.45 Cooperation theory would suggest that if the sampled physicians

Catharine W. Burt; David Woodwell

208

Computer program for simulation of variable recharge with the U. S. Geological Survey modular finite-difference ground-water flow model (MODFLOW)  

USGS Publications Warehouse

The Variable-Recharge Package is a computerized method designed for use with the U.S. Geological Survey three-dimensional finitedifference ground-water flow model (MODFLOW-88) to simulate areal recharge to an aquifer. It is suitable for simulations of aquifers in which the relation between ground-water levels and land surface can affect the amount and distribution of recharge. The method is based on the premise that recharge to an aquifer cannot occur where the water level is at or above land surface. Consequently, recharge will vary spatially in simulations in which the Variable- Recharge Package is applied, if the water levels are sufficiently high. The input data required by the program for each model cell that can potentially receive recharge includes the average land-surface elevation and a quantity termed ?water available for recharge,? which is equal to precipitation minus evapotranspiration. The Variable-Recharge Package also can be used to simulate recharge to a valley-fill aquifer in which the valley fill and the adjoining uplands are explicitly simulated. Valley-fill aquifers, which are the most common type of aquifer in the glaciated northeastern United States, receive much of their recharge from upland sources as channeled and(or) unchanneled surface runoff and as lateral ground-water flow. Surface runoff in the uplands is generated in the model when the applied water available for recharge is rejected because simulated water levels are at or above land surface. The surface runoff can be distributed to other parts of the model by (1) applying the amount of the surface runoff that flows to upland streams (channeled runoff) to explicitly simulated streams that flow onto the valley floor, and(or) (2) applying the amount that flows downslope toward the valley- fill aquifer (unchanneled runoff) to specified model cells, typically those near the valley wall. An example model of an idealized valley- fill aquifer is presented to demonstrate application of the method and the type of information that can be derived from its use. Documentation of the Variable-Recharge Package is provided in the appendixes and includes listings of model code and of program variables. Comment statements in the program listings provide a narrative of the code. Input-data instructions and printed model output for the package are included.

Kontis, A.L.

2001-01-01

209

COMPARISON OF METHODS FOR ESTIMATING GROUND-WATER PUMPAGE FOR IRRIGATION.  

USGS Publications Warehouse

Ground-water pumpage for irrigation was measured at 32 sites on the eastern Snake River Plain in southern Idaho during 1983. Pumpage at these sites also was estimated by three commonly used methods, and pumpage estimates were compared to measured values to determine the accuracy of each estimate. Statistical comparisons of estimated and metered pumpage using an F-test showed that only estimates made using the instantaneous discharge method were not significantly different ( alpha equals 0. 01) from metered values. Pumpage estimates made using the power consumption method reflect variability in pumping efficiency among sites. Pumpage estimates made using the crop-consumptive use method reflect variability in water-management practices. Pumpage estimates made using the instantaneous discharge method reflect variability in discharges at each site during the irrigation season.

Frenzel, Steven A.

1985-01-01

210

Comparison of the effects of filtration and preservation methods on analyses for strontium-90 in ground water  

USGS Publications Warehouse

From 1952 to 1988, about 140 curies of strontium-90 were discharged in liquid waste to disposal ponds and wells at the INEL (Idaho National Engineering Laboratory). Water from four wells was sampled as part of the U.S. Geological Survey's quality-assurance program to evaluate the effects of filtration and preservation methods on strontium-90 concentrations in ground water at the INEL. Water from each well was filtered through eithera 0.45- or a 0.1-micrometer membrane filter; unfiltered samples also were collected. Two sets of filtered and two sets of unfiltered water samples were collected at each well. One of the two sets of water samples was field acidified. Strontium-90 concentrations ranged from below the reporting level to 52 ?? 4 picocuries per liter. Descriptive statistics were used to determine reproducibility of the analytical results for strontium-90 concentrations in water from each well. Comparisons were made with unfiltered, acidified samples at each well. Analytical results for strontium-90 concentrations in water from well 88 were not in statistical agreement between the unfiltered, acidified sample and the filtered (0.45 micrometer), acidified sample. The strontium-90 concentration for water from well 88 was less than the reporting level. For water from wells with strontium-90 concentrations at or above the reporting level, 94 percent or more of the strontium-90 is in true solution or in colloidal particles smaller than 0.1 micrometer. These results suggest that changes in filtration and preservation methods used for sample collection do not significantly affect reproducibility of strontium-90 analyses in ground water at the INEL.

Knobel, L.L.; DeWayne, Cecil L.; Wegner, S.J.; Moore, L.L.

1992-01-01

211

A multi-method high-resolution geophysical survey in the Machado de Castro museum, central Portugal  

NASA Astrophysics Data System (ADS)

Restoration of historical buildings is a delicate operation as they are often built over more ancient and important structures. The Machado de Castro Museum, Coimbra, Central Portugal, has suffered several interventions in historical times and lies over the ancient Roman forum of Coimbra. This building went through a restoration project. These works were preceded by an extensive geophysical survey that aimed at investigating subsurface stratigraphy, including archeological remains, and the internal structure of the actual walls. Owing to the needs of the project, geophysical data interpretation required not only integration but also high resolution. The study consisted of data acquisition over perpendicular planes and different levels that required detailed survey planning and integration of data from different locations that complement images of the surveyed area. Therefore a multi-method, resistivity imaging and a 3D ground probing radar (GPR), high-resolution geophysical survey was done inside the museum. Herein, radargrams are compared with the revealed stratigraphy so that signatures are interpreted, characterized and assigned to archeological structures. Although resistivity and GPR have different resolution capabilities, their data are overlapped and compared, bearing in mind the specific characteristics of this survey. It was also possible to unravel the inner structure of the actual walls, to establish connections between walls, foundations and to find older remains with the combined use and spatial integration of the GPR and resistivity imaging data.

Grangeia, Carlos; Matias, Manuel; Figueiredo, Fernando; Hermozilha, Hélder; Carvalho, Pedro; Silva, Ricardo

2011-06-01

212

Understanding Sample Surveys: Selective Learning about Social Science Research Methods  

ERIC Educational Resources Information Center

We investigate differences in what students learn about survey methodology in a class on public opinion presented in two critically different ways: with the inclusion or exclusion of an original research project using a random-digit-dial telephone survey. Using a quasi-experimental design and data obtained from pretests and posttests in two public…

Currin-Percival, Mary; Johnson, Martin

2010-01-01

213

Topsoil thickness mapping at watershed scale by integration of field survey, geophysics and remote sensing methods  

NASA Astrophysics Data System (ADS)

The adequate parameterisation of near subsurface is a critical issue due to the large spatial variability of soil properties. Direct observations made by common invasive field sampling procedures through drilling and trench excavations can be complemented in an efficient way by non-invasive geophysical methods, improving spatial data coverage in cost and time efficient way. The geophysical methods measure a physical property of subsurface that is convertible into the parameter or variable of interest. Such conversion requires development of data integration method. In this study, we present a methodology of data integration to assess spatially the topsoil thickness at the watershed scale. To integrate the spatial variability of the soil characteristics, we used a combination of field survey, ground-geophysics, satellite and aerial imagery processing and statistical estimation techniques. The ground-geophysics was used to complement and extend the direct field observations of the topsoil thickness. The conversion of the geophysical data in topsoil thickness and the estimation of the topsoil thickness over the catchment were done through statistical methods that integrated auxiliary variables derived from the remote sensing imagery (soil and geomorphology classifications and terrain attributes). A simple and expedite soil classification based on multi-resolution segmentation of image objects and fuzzy logic was derived from a high-resolution multispectral QuickBird image combined with aerial photograph. Landform classes and terrain attributes were computed from the Global Digital Elevation Model (GDEM) of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite. We applied this methodology to the Pisões catchment (~19 km2, Portugal) where the AB horizon, following the standard pedologic classification, is characterized by its high concentration in swelling clay. In the first step, we elaborated the sampling schema of the geophysical survey using a dataset compiled from previous studies of 48 observations of the topsoil thickness made through augering, profiling and drilling. We opted to measure the soil apparent electrical conductivity (ECa) using a GeonicsTM ground conductivity meter EM-31 because: i) the AB horizon thickness was within the range of penetration depth of this instrument; ii) a significant contrast between the electrical conductivities of the AB and C horizons was expected and confirmed by measurements. We assumed that the spatial variation of ECa over the study area was mainly controlled by the high clay content and the thickness of the AB horizon. The influence of the soil moisture content was minimized by taking the ECa measurements at the end of the dry season. We executed 6 transects, perpendicular to the main streams, which constituted 424 survey locations separated by a median distance of 21 m. Complementary direct observations were also made by using percussion drilling and digging at 22 locations along the geophysical transects. The second step was to convert the ECa measurements into topsoil thickness using a linear regression (LR) model. The obtained dataset was used in the third and last step to estimate the topsoil thickness over the catchment selecting the appropriate geostatistical mixed linear model (MLM). In these two last steps, the remote sensing derived auxiliary variables were tested and integrated in the models to improve the relationship. To avoid collinearity effects in the models, the auxiliary predictors were selected using principal component analysis. The selection of the appropriate geostatistical MLM was done by testing the normality and the spatial correlation of the residuals (respectively Shapiro-Wilk and Moran tests). The error propagation in the models was considered and integrated in the results. Final assessment of the estimation was made by computing the root mean square error (RMSE) at 61 locations of the observed dataset.

Francés, Alain Pascal; Lubczynski, Maciek

2010-05-01

214

A Survey of Formal Methods for Intelligent Swarms  

NASA Technical Reports Server (NTRS)

Swarms of intelligent autonomous spacecraft, involving complex behaviors and interactions, are being proposed for future space exploration missions. Such missions provide greater flexibility and offer the possibility of gathering more science data than traditional single spacecraft missions. The emergent properties of swarms make these missions powerful, but simultaneously far more difficult to design, and to assure that the proper behaviors will emerge. These missions are also considerably more complex than previous types of missions, and NASA, like other organizations, has little experience in developing or in verifying and validating these types of missions. A significant challenge when verifying and validating swarms of intelligent interacting agents is how to determine that the possible exponential interactions and emergent behaviors are producing the desired results. Assuring correct behavior and interactions of swarms will be critical to mission success. The Autonomous Nano Technology Swarm (ANTS) mission is an example of one of the swarm types of missions NASA is considering. The ANTS mission will use a swarm of picospacecraft that will fly from Earth orbit to the Asteroid Belt. Using an insect colony analogy, ANTS will be composed of specialized workers for asteroid exploration. Exploration would consist of cataloguing the mass, density, morphology, and chemical composition of the asteroids, including any anomalous concentrations of specific minerals. To perform this task, ANTS would carry miniaturized instruments, such as imagers, spectrometers, and detectors. Since ANTS and other similar missions are going to consist of autonomous spacecraft that may be out of contact with the earth for extended periods of time, and have low bandwidths due to weight constraints, it will be difficult to observe improper behavior and to correct any errors after launch. Providing V&V (verification and validation) for this type of mission is new to NASA, and represents the cutting edge in system correctness, and requires higher levels of assurance than other (traditional) missions that use a single or small number of spacecraft that are deterministic in nature and have near continuous communication access. One of the highest possible levels of assurance comes from the application of formal methods. Formal methods are mathematics-based tools and techniques for specifying and verifying (software and hardware) systems. They are particularly useful for specifying complex parallel systems, such as exemplified by the ANTS mission, where the entire system is difficult for a single person to fully understand, a problem that is multiplied with multiple developers. Once written, a formal specification can be used to prove properties of a system (e.g., the underlying system will go from one state to another or not into a specific state) and check for particular types of errors (e.g., race or livelock conditions). A formal specification can also be used as input to a model checker for further validation. This report gives the results of a survey of formal methods techniques for verification and validation of space missions that use swarm technology. Multiple formal methods were evaluated to determine their effectiveness in modeling and assuring the behavior of swarms of spacecraft using the ANTS mission as an example system. This report is the first result of the project to determine formal approaches that are promising for formally specifying swarm-based systems. From this survey, the most promising approaches were selected and are discussed relative to their possible application to the ANTS mission. Future work will include the application of an integrated approach, based on the selected approaches identified in this report, to the formal specification of the ANTS mission.

Truszkowski, Walt; Rash, James; Hinchey, Mike; Rouff, Chrustopher A.

2004-01-01

215

Methods for nonlinear analysis, simulation and animation of land-survey spacecraft guidance  

NASA Astrophysics Data System (ADS)

Obtained in the space photos a ground resolution depends on a spacecraft spatial angular motion during optoelectronic survey. The paper studies case of optimal equalization of an image longitudinal velocity in the focal plane of telescope and tackles the problem of defining initial azimuth of the scanning survey under the condition of minimizing quadratic functional of image cross velocity values on edges of the CCD linear array. Results of a simulated survey of random surface object are presented, and the change of initial azimuth value for various survey angles within the swath is examined. The paper presents also a brief description of developed software for designing the space telescope characteristics, simulation and animation of the land-survey spacecraft spatial motion and gives recommendations for its applications.

Somov, Sergey; Somova, Tatyana

2014-12-01

216

A New Curb Detection Method for Unmanned Ground Vehicles Using 2D Sequential Laser Data  

PubMed Central

Curb detection is an important research topic in environment perception, which is an essential part of unmanned ground vehicle (UGV) operations. In this paper, a new curb detection method using a 2D laser range finder in a semi-structured environment is presented. In the proposed method, firstly, a local Digital Elevation Map (DEM) is built using 2D sequential laser rangefinder data and vehicle state data in a dynamic environment and a probabilistic moving object deletion approach is proposed to cope with the effect of moving objects. Secondly, the curb candidate points are extracted based on the moving direction of the vehicle in the local DEM. Finally, the straight and curved curbs are detected by the Hough transform and the multi-model RANSAC algorithm, respectively. The proposed method can detect the curbs robustly in both static and typical dynamic environments. The proposed method has been verified in real vehicle experiments. PMID:23325170

Liu, Zhao; Wang, Jinling; Liu, Daxue

2013-01-01

217

A new curb detection method for unmanned ground vehicles using 2D sequential laser data.  

PubMed

Curb detection is an important research topic in environment perception, which is an essential part of unmanned ground vehicle (UGV) operations. In this paper, a new curb detection method using a 2D laser range finder in a semi-structured environment is presented. In the proposed method, firstly, a local Digital Elevation Map (DEM) is built using 2D sequential laser rangefinder data and vehicle state data in a dynamic environment and a probabilistic moving object deletion approach is proposed to cope with the effect of moving objects. Secondly, the curb candidate points are extracted based on the moving direction of the vehicle in the local DEM. Finally, the straight and curved curbs are detected by the Hough transform and the multi-model RANSAC algorithm, respectively. The proposed method can detect the curbs robustly in both static and typical dynamic environments. The proposed method has been verified in real vehicle experiments. PMID:23325170

Liu, Zhao; Wang, Jinling; Liu, Daxue

2013-01-01

218

National hospital survey of anaerobic culture and susceptibility methods: III.  

PubMed

To assess the current status of anaerobic bacteriology in the United States, we surveyed, by means of a questionnaire, 150 hospitals selected at random with bed capacities of 200-1000 and we received responses from 98 (65%). Ninety-eight percent processed anaerobic culture specimens with 21% sending them to reference laboratories. Almost all these hospitals processed blood and wound cultures for anaerobes and all used selective media for identification, including BBE (52%), LKV (77%), and PEA (53%) agars. All hospital laboratories attempted identification of blood culture isolates including 80% that attempted speciation. Wound cultures for anaerobic bacteria and sterile site cultures were also processed for anaerobes by almost all labs. Identification of B. fragilis group species to species level was performed only in 56% of labs always and 37% sometimes. Preformed enzyme kits were used by 66% of labs and 30% used special potency disks for identification. Susceptibility testing was performed in-house by 21% of hospital labs and sent out to reference labs an additional 20%. Susceptibility testing was attempted for all blood culture isolates by both hospital (21% of total labs) and reference laboratories, but only performed by 17% for sterile body site and 14% of the time for wound isolates. Etest was used most often followed by broth microdilution. No labs used the agar dilution or disk elution methods. The antimicrobials most often tested in hospital labs, predicated on the commercial panel used, were penicillin/ampicillin and clindamycin (15/18; 83%; 15% of total labs), metronidazole (16/18; 89%; 16% of total labs) and cefotetan and ampicillin/sulbactam (12/18; 67%; 12% of total labs), piperacillin/tazobactam (7/18; 39%; 7% of total labs), cefoxitin (9/18; 50%), imipenem (8/18; 44%), and chloramphenicol (6/18; 33%). Our current survey suggests that while many labs are processing anaerobic cultures, especially blood cultures, the identification of isolates and the performance of antimicrobial susceptibility testing of isolates are in disarray and in dire need of improvement. PMID:18291689

Goldstein, Ellie J C; Citron, Diane M; Goldman, Pamela J; Goldman, Ronald J

2008-04-01

219

Methodical questions and accuracy problems of GPS observations by the example of the geodynamic proving ground in Bishkek  

NASA Astrophysics Data System (ADS)

The key questions concerning the modern methodical tasks and accuracy of GPS measurements of crustal motion spanning are discussed for a full cycle of the survey from the organization of the field operations to the interpretation of the final results. The presented data rely on the 20-year experience of the geophysicists of the Research Station of the Russian Academy of Sciences in Bishkek (RS RAS) in GPS monitoring at the Geodynamic Proving Ground in Bishkek (GPGB) and in a large part of Central Asia. The comparative characteristics of the constellations of visible GPS and GLONASS satellites are analyzed from the standpoint of their practical application for precise scientific observations of crustal motions. The studies of the contemporary movements of the Earth's crust by the methods of satellite geodesy generally comprise three stages: (1) organization of the measurement networks and acquisition of the data; (2) data processing; and (3) interpretation of the results. Each stage is associated with its own block of the tasks and problems, and neither is guaranteed against uncertainties and errors which may affect the results, conclusions, and reconstructions.

Kuzikov, S. I.

2014-11-01

220

A double-observer method for reducing bias in faecal pellet surveys of forest ungulates  

USGS Publications Warehouse

1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0.2-1.0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic. ?? 2008 The Authors.

Jenkins, K.J.; Manly, B.F.J.

2008-01-01

221

Geophysical monitoring of simulated clandestine graves using electrical and ground-penetrating radar methods: 0-3 years after burial.  

PubMed

This study provides forensic search teams with systematic geophysical monitoring data over simulated clandestine graves for comparison to active cases. Simulated "wrapped" and "naked" burials were created. Multigeophysical surveys were collected over a 3-year monitoring period. Bulk ground resistivity, electrical resistivity imaging, multifrequency ground-penetrating radar (GPR), and grave and background "soil-water" conductivity data were collected. Resistivity surveys revealed the naked burial had consistently low-resistivity anomalies, whereas the wrapped burial had small, varying high-resistivity anomalies. GPR 110- to 900-MHz frequency surveys showed the wrapped burial could be detected throughout, with the "naked" burial mostly resolved. Two hundred and twenty-five megahertz frequency GPR data were optimal. "Soil-water" analyses showed rapidly increasing (year 1), slowly increasing (year 2), and decreasing (year 3) conductivity values. Results suggest resistivity and GPR surveys should be collected if target "wrapping" is unknown, with winter to spring surveys optimal. Resistivity surveys should be collected in clay-rich soils. PMID:22509973

Pringle, Jamie K; Jervis, John R; Hansen, James D; Jones, Glenda M; Cassidy, Nigel J; Cassella, John P

2012-11-01

222

A Method for Numerical Simulation of Single Limb Ground Contact Events: Application to Heel-Toe Running  

Microsoft Academic Search

The objective of this work was to develop a method to simulate single-limb ground contact events, which may be applied to study musculoskeletal injuries associated with such movements. To achieve this objective, a three-dimensional musculoskeletal model was developed consisting of the equations of motion for the musculoskeletal system, and models for the muscle force generation and ground contact elements. An

R. R. NEPTUNE; I. C. WRIGHT; A. J. VAN DEN BOGERT

2000-01-01

223

A Deep Percolation Model for Estimating Ground-Water Recharge: Documentation of Modules for the Modular Modeling System of the U.S. Geological Survey  

USGS Publications Warehouse

A daily water-budget model for estimating ground-water recharge, the Deep Percolation Model, was modularized for inclusion into the U.S. Geological Survey's Modular Modeling System. The model was modularized in order to facilitate estimation of ground-water recharge under a large range in climatic, landscape, and land-use and land-cover conditions. The model can be applied to areas as large as regions or as small as a field plot. An overview of the Modular Modeling System and the Deep Percolation Model is presented. Data requirements, parameters, and variables for the model are described. The modules that compose the Deep Percolation Model are documented.

Vaccaro, J.J.

2007-01-01

224

Results of a Flight Simulation Software Methods Survey  

NASA Technical Reports Server (NTRS)

A ten-page questionnaire was mailed to members of the AIAA Flight Simulation Technical Committee in the spring of 1994. The survey inquired about various aspects of developing and maintaining flight simulation software, as well as a few questions dealing with characterization of each facility. As of this report, 19 completed surveys (out of 74 sent out) have been received. This paper summarizes those responses.

Jackson, E. Bruce

1995-01-01

225

A six-beam method to measure turbulence statistics using ground-based wind lidars  

NASA Astrophysics Data System (ADS)

A so-called six-beam method is proposed to measure atmospheric turbulence using a ground-based wind lidar. This method requires measurement of the radial velocity variances at five equally spaced azimuth angles on the base of a scanning cone and one measurement at the centre of the scanning circle, i.e.using a vertical beam at the same height. The scanning configuration is optimized to minimize the sum of the random errors in the measurement of the second-order moments of the components (u,v, w) of the wind field. We present this method as an alternative to the so-called velocity azimuth display (VAD) method that is routinely used in commercial wind lidars, and which usually results in significant averaging effects of measured turbulence. In the VAD method, the high frequency radial velocity measurements are used instead of their variances. The measurements are performed using a pulsed lidar (WindScanner), and the derived turbulence statistics (using both methods) such as the u and v variances are compared with those obtained from a reference cup anemometer and a wind vane at 89 m height under different atmospheric stabilities. The measurements show that in comparison to the reference cup anemometer, depending on the atmospheric stability and the wind field component, the six-beam method measures between 85 and 101% of the reference turbulence, whereas the VAD method measures between 66 and 87% of the reference turbulence.

Sathe, A.; Mann, J.; Vasiljevic, N.; Lea, G.

2015-02-01

226

Testing alternative ground water models using cross-validation and other methods.  

PubMed

Many methods can be used to test alternative ground water models. Of concern in this work are methods able to (1) rank alternative models (also called model discrimination) and (2) identify observations important to parameter estimates and predictions (equivalent to the purpose served by some types of sensitivity analysis). Some of the measures investigated are computationally efficient; others are computationally demanding. The latter are generally needed to account for model nonlinearity. The efficient model discrimination methods investigated include the information criteria: the corrected Akaike information criterion, Bayesian information criterion, and generalized cross-validation. The efficient sensitivity analysis measures used are dimensionless scaled sensitivity (DSS), composite scaled sensitivity, and parameter correlation coefficient (PCC); the other statistics are DFBETAS, Cook's D, and observation-prediction statistic. Acronyms are explained in the introduction. Cross-validation (CV) is a computationally intensive nonlinear method that is used for both model discrimination and sensitivity analysis. The methods are tested using up to five alternative parsimoniously constructed models of the ground water system of the Maggia Valley in southern Switzerland. The alternative models differ in their representation of hydraulic conductivity. A new method for graphically representing CV and sensitivity analysis results for complex models is presented and used to evaluate the utility of the efficient statistics. The results indicate that for model selection, the information criteria produce similar results at much smaller computational cost than CV. For identifying important observations, the only obviously inferior linear measure is DSS; the poor performance was expected because DSS does not include the effects of parameter correlation and PCC reveals large parameter correlations. PMID:17760588

Foglia, L; Mehl, S W; Hill, M C; Perona, P; Burlando, P

2007-01-01

227

Ground penetrating radar survey on the cross-stratified overbank deposits from the 2006 eruption of Tungurahua volcano, Ecuador.  

NASA Astrophysics Data System (ADS)

The deposits of the 2006 pyroclastic density currents (PDCs) at Tungurahua are organized as 1) massive, coarse-grained deposits confined to valleys of the drainage network and 2) cross-stratified, ash-dominated overbank deposits from dilute PDCs. These overbank deposits are exceptionally well preserved and show dune bedforms shaping the surface of the outcrops. In order to gain insights into the depositional mechanisms of the latter, we combined a terrestrial laser scanner (TLS) survey with a ground penetrating radar (GPR) dense network of profiles. The GPR survey permits to look at the internal cross stratification patterns in a non-destructive way. Three antennas with frequencies at 250, 500 and 800 MHz, respectively, permitted to image down to 10, 7 and 3 m depth. While the 800 MHz antenna was found to be very efficient to image cross-lamination, the 250 MHz antenna permitted to recognize major flow units. The GPR dataset profits from the TLS topography data, which are integrated in the processing of the data. From a dense array (profiles at 10 cm spacing) over different types of dune bedforms with the 800 MHz antenna, we manage to reconstruct the 3D internal patterns. Using the 250 MHz antenna, >50 profiles (20-80 m length) over a zone ca. 300*300 m permit to reconstruct and follow the major flow units on the overbanks and their 3D evolution as well as the pre-eruptive paleosoil. Notable results are: (1) the revelation of several units of dense pyroclastic flow deposits below the dilute PDC deposits on the overbanks. This may indicate that the valleys were filled by the time of deposition of the dune bedforms, a result not inferred in previous studies. Moreover, the number of units is greater than previously accessed. (2) For dune bedforms, the root of a structure is found to be located deeper than expected with striking spatial stability during the whole deposition stage, indicating that these bedforms are triggered by basal topographic disturbance. (3) Looking at their 3D patterns, most dune bedforms have a monotone profile, ruling out genesis from currents with different orientations. (4) In some outcrops however, cross-stratifications evolve laterally from stoss-erosive through aggrading to stoss-aggrading, implying that a single dune bedform can show both downstream and upstream migrating crests during the same stage of the flow. (5) Several structures cannibalized by a larger one show proof that the bed rapidly accommodates temporal changes in the dynamics of the currents.

Amin Douillet, Guilhem; Abolghasem, Amir; Rémi Dujardin, Jean; Kueppers, Ulrich; Hall, Jonathan; Mothes, Patricia; Dingwell, Donald

2013-04-01

228

Predictions on the number of variable stars for the GAIA space mission and for surveys as the ground-based International Liquid Mirror Telescope  

E-print Network

Future space and ground-based survey programmes will produce an impressive amount of photometric data. The GAIA space mission will map the complete sky down to mag V=20 and produce time series for about 1 billion stars. Survey instruments as the International Liquid Mirror Telescope will observe slices of the sky down to magnitude V=23. In both experiments, the opportunity exists to discover a huge amount of variable stars. A prediction of the expected total number of variable stars and the number of variables in specific subgroups is given.

Laurent Eyer; Jan Cuypers

2000-02-20

229

Development of Improved Traveler Survey Methods for High-Speed Intercity Passenger Rail Planning  

E-print Network

DEVELOPMENT OF IMPROVED TRAVELER SURVEY METHODS FOR HIGH- SPEED INTERCITY PASSENGER RAIL PLANNING A Dissertation by BENJAMIN ROBERT SPERRY Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2012 Major Subject: Civil Engineering Development of Improved Traveler Survey Methods for High...

Sperry, Benjamin

2012-07-16

230

Consulting the Delphi: A New Idea for Collecting Student Feedback through the Two Survey Method (TSM)  

ERIC Educational Resources Information Center

The Two Survey Method (TSM) is a new time-efficient tool for gathering formative student feedback. Based on the Delphi technique, the TSM uses iterative surveys to develop student consensus about key strengths and suggestions for instruction. Evaluation data indicate that both faculty and students are satisfied with the method's efficiency and the…

Finelli, Cynthia J.; Wright, Mary C.; Pinder-Grover, Tershia

2010-01-01

231

Using surveys to identify stressors in generalized jobs: A direct clustering method  

Microsoft Academic Search

The objective of this research was to develop a method for identifying the tasks involved in a given general-description job and each such task's associated physiological and psychological stress factors. The resulting method consisted of a three-section survey followed by a short interview. The first two sections of the survey provide descriptive information concerning both employee demographics and the physiological

Grady T. Holman; Brian J. Carnahan; Robert E. Thomas

2006-01-01

232

77 FR 24684 - Proposed Information Collection; Comment Request; 2013-2015 American Community Survey Methods...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Information Collection; Comment Request; 2013-2015 American Community Survey Methods Panel...survey issues and needs. During the 2013-2015 period, the Methods Panel may include...A 2013 Questionnaire Design Test, a 2015 ACS Content Test, and a series of...

2012-04-25

233

A Modified Analytical Method for Simulating Cyclic Operation of Vertical U-Tube Ground-Coupled Heat Pumps  

E-print Network

solutions inside the soil, and comes closer than previous analytical methods to satisfying the constant heat flux assumption of the original analytical solution. The thermal capacitance effects of the fluid inside the ground-coupled heat exchanger...

Dobson, M. K.; O'Neal, D. L.; Aldred, W.

1994-01-01

234

An individual and dynamic Body Segment Inertial Parameter validation method using ground reaction forces.  

PubMed

Over the last decades a variety of research has been conducted with the goal to improve the Body Segment Inertial Parameters (BSIP) estimations but to our knowledge a real validation has never been completely successful, because no ground truth is available. The aim of this paper is to propose a validation method for a BSIP identification method (IM) and to confirm the results by comparing them with recalculated contact forces using inverse dynamics to those obtained by a force plate. Furthermore, the results are compared with the recently proposed estimation method by Dumas et al. (2007). Additionally, the results are cross validated with a high velocity overarm throwing movement. Throughout conditions higher correlations, smaller metrics and smaller RMSE can be found for the proposed BSIP estimation (IM) which shows its advantage compared to recently proposed methods as of Dumas et al. (2007). The purpose of the paper is to validate an already proposed method and to show that this method can be of significant advantage compared to conventional methods. PMID:24704168

Hansen, Clint; Venture, Gentiane; Rezzoug, Nasser; Gorce, Philippe; Isableu, Brice

2014-05-01

235

Simulation of cylindrical flow to a well using the U.S. Geological Survey Modular Finite-Difference Ground-Water Flow Model  

USGS Publications Warehouse

Cylindrical (axisymmetric) flow to a well is an important specialized topic of ground-water hydraulics and has been applied by many investigators to determine aquifer properties and determine heads and flows in the vicinity of the well. A recent modification to the U.S. Geological Survey Modular Three-Dimensional Finite-Difference Ground-Water Flow Model provides the opportunity to simulate axisymmetric flow to a well. The theory involves the conceptualization of a system of concentric shells that are capable of reproducing the large variations in gradient in the vicinity of the well by decreasing their area in the direction of the well. The computer program presented serves as a preprocessor to the U.S. Geological Survey model by creating the input data file needed to implement the axisymmetric conceptualization. Data input requirements to this preprocessor are described, and a comparison with a known analytical solution indicates that the model functions appropriately.

Reilly, Thomas E.; Harbaugh, Arlen W.

1993-01-01

236

LRES 510 Biodiversity Survey and Monitoring Methods Class Syllabus CRN: 24447  

E-print Network

LRES 510 Biodiversity Survey and Monitoring Methods Class Syllabus CRN concerning biodiversity at multiple scales in time and space. This course about biodiversity. We will concentrate on applying and evaluating these methods

Maxwell, Bruce D.

237

The ZInEP Epidemiology Survey: background, design and methods.  

PubMed

This article introduces the design, sampling, field procedures and instruments used in the ZInEP Epidemiology Survey. This survey is one of six ZInEP projects (Zürcher Impulsprogramm zur nachhaltigen Entwicklung der Psychiatrie, i.e. the "Zurich Program for Sustainable Development of Mental Health Services"). It parallels the longitudinal Zurich Study with a sample comparable in age and gender, and with similar methodology, including identical instruments. Thus, it is aimed at assessing the change of prevalence rates of common mental disorders and the use of professional help and psychiatric sevices. Moreover, the current survey widens the spectrum of topics by including sociopsychiatric questionnaires on stigma, stress related biological measures such as load and cortisol levels, electroencephalographic (EEG) and near-infrared spectroscopy (NIRS) examinations with various paradigms, and sociophysiological tests. The structure of the ZInEP Epidemiology Survey entails four subprojects: a short telephone screening using the SCL-27 (n of nearly 10,000), a comprehensive face-to-face interview based on the SPIKE (Structured Psychopathological Interview and Rating of the Social Consequences for Epidemiology: the main instrument of the Zurich Study) with a stratified sample (n?=?1500), tests in the Center for Neurophysiology and Sociophysiology (n?=?227), and a prospective study with up to three follow-up interviews and further measures (n?=?157). In sum, the four subprojects of the ZInEP Epidemiology Survey deliver a large interdisciplinary database. PMID:24942564

Ajdacic-Gross, Vladeta; Müller, Mario; Rodgers, Stephanie; Warnke, Inge; Hengartner, Michael P; Landolt, Karin; Hagenmuller, Florence; Meier, Magali; Tse, Lee-Ting; Aleksandrowicz, Aleksandra; Passardi, Marco; Knöpfli, Daniel; Schönfelder, Herdis; Eisele, Jochen; Rüsch, Nicolas; Haker, Helene; Kawohl, Wolfram; Rössler, Wulf

2014-12-01

238

Analysis of Nonlinearly Loaded Multiport Antenna Structures Over an Imperfect Ground Plane Using the Volterra-Series Method  

Microsoft Academic Search

Volterra-series analysis is applied to nonlinearly loaded antennas over an imperfect ground plane. The nature of the imperfect ground can be taken into account either exactly by the Sommerfeld formulation or approximately by the reflection-coefficient method. After the electromagnetic-field problem is reduced to a network problem by application of the method of moments, the distributed nonlinear loads are approximated by

Tapan Sarkar; Donald Weiner; Roger Harrington

1978-01-01

239

A wavelet-based baseline drift correction method for grounded electrical source airborne transient electromagnetic signals  

NASA Astrophysics Data System (ADS)

A grounded electrical source airborne transient electromagnetic (GREATEM) system on an airship enjoys high depth of prospecting and spatial resolution, as well as outstanding detection efficiency and easy flight control. However, the movement and swing of the front-fixed receiving coil can cause severe baseline drift, leading to inferior resistivity image formation. Consequently, the reduction of baseline drift of GREATEM is of vital importance to inversion explanation. To correct the baseline drift, a traditional interpolation method estimates the baseline `envelope' using the linear interpolation between the calculated start and end points of all cycles, and obtains the corrected signal by subtracting the envelope from the original signal. However, the effectiveness and efficiency of the removal is found to be low. Considering the characteristics of the baseline drift in GREATEM data, this study proposes a wavelet-based method based on multi-resolution analysis. The optimal wavelet basis and decomposition levels are determined through the iterative comparison of trial and error. This application uses the sym8 wavelet with 10 decomposition levels, and obtains the approximation at level-10 as the baseline drift, then gets the corrected signal by removing the estimated baseline drift from the original signal. To examine the performance of our proposed method, we establish a dipping sheet model and calculate the theoretical response. Through simulations, we compare the signal-to-noise ratio, signal distortion, and processing speed of the wavelet-based method and those of the interpolation method. Simulation results show that the wavelet-based method outperforms the interpolation method. We also use field data to evaluate the methods, compare the depth section images of apparent resistivity using the original signal, the interpolation-corrected signal and the wavelet-corrected signal, respectively. The results confirm that our proposed wavelet-based method is an effective, practical method to remove the baseline drift of GREATEM signals and its performance is significantly superior to the interpolation method.

Wang, Yuan 1Ji, Yanju 2Li, Suyi 13Lin, Jun 12Zhou, Fengdao 1Yang, Guihong

2013-09-01

240

A comparison of several surface finish measurement methods as applied to ground ceramic and metal surfaces  

SciTech Connect

Surface finish is one of the most common measures of surface quality of ground ceramics and metal parts and a wide variety of methods and parameters have been developed to measure it. The purpose of this investigation was to compare the surface roughness parameters obtained on the same two specimens from three different types of measuring instruments: a traditional mechanical stylus system, a non-contact laser scanning system, and the atomic force microscope (two different AFM systems were compared). The same surface-ground silicon nitride and Inconel 625 alloy specimens were used for all measurements in this investigation. Significant differences in arithmetic average roughness, root-mean-square roughness, and peak-to-valley roughness were obtained when comparing data from the various topography measuring instruments. Non-contact methods agreed better with the others on the metal specimen than on the ceramic specimen. Reasons for these differences include the effective dimensions and geometry of the probe with respect to the surface topography; the reflectivity of the surface, and the type of filtering scheme Results of this investigation emphasize the importance of rigorously specifying the manner of surface roughness measurement when either reporting roughness data or when requesting that roughness data be provided.

Blau, P.J.; Martin, R.L.; Riester, L.

1996-01-01

241

Selected reports that include computer programs produced by the US Geological Survey for simulation of ground-water flow and quality  

USGS Publications Warehouse

A summary list of reports that document numerical models that simulate ground-water flow and quality is presented. The list documents the reference by giving a description of each model program, its numerical features, a qualitative expression of the number of past applications and where to obtain a copy. All reports included in the list have been published or developed by the U.S. Geological Survey and most contain listings of the computer programs. (Author 's abstract)

Appel, C.A.; Reilly, T.E.

1988-01-01

242

Sightability adjustment methods for aerial surveys of wildlife populations  

USGS Publications Warehouse

Aerial surveys are routinely conducted to estimate the abundance of wildlife species and the rate of population change. However, sightability of animal groups is acknowledged as a significant source of bias in these estimates. Recent research has focused on the development of sightability models to predict the probability of sighting groups under various conditions. Given such models, we show how sightability can be incorporated into the estimator of population size as a probability of response using standard results from sample surveys. We develop formulas for the cases where the sighting probability must be estimated. An example, using data from a helicopter survey of moose in Alberta (Jacobson, Alberta Oil Sands Research Project Report, 1976), is given to illustrate the technique.

Steinhorst, R.K.; Samuel, M.D.

1989-01-01

243

Quantifying greenhouse gas emissions from coal fires using airborne and ground-based methods  

USGS Publications Warehouse

Coal fires occur in all coal-bearing regions of the world and number, conservatively, in the thousands. These fires emit a variety of compounds including greenhouse gases. However, the magnitude of the contribution of combustion gases from coal fires to the environment is highly uncertain, because adequate data and methods for assessing emissions are lacking. This study demonstrates the ability to estimate CO2 and CH4 emissions for the Welch Ranch coal fire, Powder River Basin, Wyoming, USA, using two independent methods: (a) heat flux calculated from aerial thermal infrared imaging (3.7-4.4td-1 of CO2 equivalent emissions) and (b) direct, ground-based measurements (7.3-9.5td-1 of CO2 equivalent emissions). Both approaches offer the potential for conducting inventories of coal fires to assess their gas emissions and to evaluate and prioritize fires for mitigation. ?? 2011.

Engle, M.A.; Radke, L.F.; Heffern, E.L.; O'Keefe, J. M. K.; Smeltzer, C.D.; Hower, J.C.; Hower, J.M.; Prakash, A.; Kolker, A.; Eatwell, R.J.; ter, Schure A.; Queen, G.; Aggen, K.L.; Stracher, G.B.; Henke, K.R.; Olea, R.A.; Roman-Colon, Y.

2011-01-01

244

Correction method for obtaining the variationally best ground-state pair density  

SciTech Connect

We present a correction method for the pair density (PD) to get close to the ground-state one. The PD is corrected to be a variationally best PD within the search region that is extended by adding the uniformly scaled PDs to its elements. The corrected PD is kept N-representable and satisfies the virial relation rigorously. The validity of the present method is confirmed by numerical calculations of neon atom. It is shown that the root-mean-square error of the electron-electron interaction and external potential energies, which is a good benchmark for the error of the PD, is reduced by 69.7% without additional heavy calculations.

Higuchi, Masahiko; Higuchi, Katsuhiko [Department of Physics, Faculty of Science, Shinshu University, Matsumoto 390-8621 (Japan); Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)

2011-10-15

245

Efficient Continuous-time Quantum Monte Carlo Method for the Ground State of Correlated Fermions  

E-print Network

We present the ground state extension of the efficient quantum Monte Carlo algorithm for lattice fermions of arXiv:1411.0683. Based on continuous-time expansion of imaginary-time projection operator, the algorithm is free of systematic error and scales \\emph{linearly} with projection time and interaction strength. Compared to the conventional quantum Monte Carlo methods for lattice fermions, this approach has greater flexibility and is easier to combine with powerful machinery such as histogram reweighting and extended ensemble simulation techniques. We discuss the implementation of the continuous-time projection in detail using the spinless $t-V$ model as an example and compare the numerical results with exact diagonalization, density-matrix-renormalization-group and infinite projected entangled-pair states calculations. Finally we use the method to study the fermionic quantum critical point of spinless fermions on a honeycomb lattice and confirm previous results concerning its critical exponents.

Wang, Lei; Corboz, Philippe; Troyer, Matthias

2015-01-01

246

Efficient Continuous-time Quantum Monte Carlo Method for the Ground State of Correlated Fermions  

E-print Network

We present the ground state extension of the efficient quantum Monte Carlo algorithm for lattice fermions of arXiv:1411.0683. Based on continuous-time expansion of imaginary-time projection operator, the algorithm is free of systematic error and scales \\emph{linearly} with projection time and interaction strength. Compared to the conventional quantum Monte Carlo methods for lattice fermions, this approach has greater flexibility and is easier to combine with powerful machinery such as histogram reweighting and extended ensemble simulation techniques. We discuss the implementation of the continuous-time projection in detail using the spinless $t-V$ model as an example and compare the numerical results with exact diagonalization, density-matrix-renormalization-group and infinite projected entangled-pair states calculations. Finally we use the method to study the fermionic quantum critical point of spinless fermions on a honeycomb lattice and confirm previous results concerning its critical exponents.

Lei Wang; Mauro Iazzi; Philippe Corboz; Matthias Troyer

2015-01-05

247

Horvitz-Thompson survey sample methods for estimating large-scale animal abundance  

USGS Publications Warehouse

Large-scale surveys to estimate animal abundance can be useful for monitoring population status and trends, for measuring responses to management or environmental alterations, and for testing ecological hypotheses about abundance. However, large-scale surveys may be expensive and logistically complex. To ensure resources are not wasted on unattainable targets, the goals and uses of each survey should be specified carefully and alternative methods for addressing these objectives always should be considered. During survey design, the impoflance of each survey error component (spatial design, propofiion of detected animals, precision in detection) should be considered carefully to produce a complete statistically based survey. Failure to address these three survey components may produce population estimates that are inaccurate (biased low), have unrealistic precision (too precise) and do not satisfactorily meet the survey objectives. Optimum survey design requires trade-offs in these sources of error relative to the costs of sampling plots and detecting animals on plots, considerations that are specific to the spatial logistics and survey methods. The Horvitz-Thompson estimators provide a comprehensive framework for considering all three survey components during the design and analysis of large-scale wildlife surveys. Problems of spatial and temporal (especially survey to survey) heterogeneity in detection probabilities have received little consideration, but failure to account for heterogeneity produces biased population estimates. The goal of producing unbiased population estimates is in conflict with the increased variation from heterogeneous detection in the population estimate. One solution to this conflict is to use an MSE-based approach to achieve a balance between bias reduction and increased variation. Further research is needed to develop methods that address spatial heterogeneity in detection, evaluate the effects of temporal heterogeneity on survey objectives and optimize decisions related to survey bias and variance. Finally, managers and researchers involved in the survey design process must realize that obtaining the best survey results requires an interactive and recursive process of survey design, execution, analysis and redesign. Survey refinements will be possible as further knowledge is gained on the actual abundance and distribution of the population and on the most efficient techniques for detection animals.

Samuel, M.D.; Garton, E.O.

1994-01-01

248

Using a fast Fourier method to model sound propagation in a stratified atmosphere over a stratified porous-elastic ground  

NASA Technical Reports Server (NTRS)

Using a Fast Fourier integration method and a global matrix method for solution of the boundary condition equations at all interfaces simultaneously, a useful tool for predicting acoustic propagation in a stratified fluid over a stratified porous-elastic solid was developed. The model for the solid is a modified Biot-Stoll model incorporating four parameters describing the pore structure corresponding to the Rayleigh-Attenborough rigid-porous structure model. The method is also compared to another Fast Fourier code (CERL-FFP) which models the ground as an impedance surface under a horizontally stratified air. Agreement with the CERL FFP is good. The effects on sound propagation of a combination of ground elasticity, complex ground structure, and atmospheric conditions are demonstrated by theoretical results over a snow layer, and experimental results over a model ground surface.

Tooms, S.; Attenborough, K.

1990-01-01

249

Comparing Coral Reef Survey Methods. Unesco Reports in Marine Science No. 21 Report of a Regional Unesco/UNEP Workshop on Coral Reef Survey Management and Assessment Methods in Asia and the Pacific (Phuket, Thailand, December 13-17, 1982).  

ERIC Educational Resources Information Center

This report includes nine papers prepared for a workshop on coral reef survey management and assessment methods in Asia and the Pacific. The papers are: "A Contrast in Methodologies between Surveying and Testing" (Charles Birkeland); "Coral Reef Survey Methods in the Andaman Sea" (Hansa Chansang); "A Review of Coral Reef Survey and Management…

United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Marine Sciences.

250

Cross Cultural Methods for Survey Research in Black Urban Areas.  

ERIC Educational Resources Information Center

This paper summarizes the development of a new approach to survey research in black urban communities, in part by adapting standard techniques. Attention is directed at a group of salient assumptions underlying social science investigations, namely: (1) the universality of majority culture models of attitude structure; (2) sociolinguistic and…

Word, Carl O.

251

A Socratic Method for Surveying Students' Readiness to Study Evolution  

ERIC Educational Resources Information Center

Before beginning a series of presentations on evolution, it would be prudent to survey the general level of students' understanding of prerequisite basic concepts of reproduction, heredity, ontology, and phenotypic diversity so that teachers can avoid devoting time to well-known subjects of general knowledge and can spend more time on subjects…

Stansfield, William D.

2013-01-01

252

Methods for Surveying Opinion among University Students and Faculty.  

ERIC Educational Resources Information Center

This report reviews: (1) instruments for measuring student perceptions of college; (2) inventories of college characteristics; (3) institutional self-studies; (4) instruments for measuring faculty perceptions of the college environment; and (5) studies on teaching evaluation. The report also contains the results of several surveys of faculty and…

Austin, Maricyl

253

FOREST SURVEY METHODS USED IN THE USDA FOREST SERVICE  

EPA Science Inventory

There has been an increasing need for forest resource inventory data to contribute to various objectives of different agencies and organizations. Monitoring forest health is one area of interest for which existing forest survey data may be useful. There are many different samplin...

254

A Survey of Eigenvector Methods for Web Information Retrieval  

Microsoft Academic Search

Web information retrieval is significantly more challenging than traditional well-controlled, small document collection information retrieval. One main difference between traditional information retrieval and Web information retrieval is the Web's hyperlink structure. This structure has been exploited by several of today's leading Web search engines, particularly Google and Teoma. In this survey paper, we focus on Web information retrieval meth- ods

Amy N. Langville; Carl D. Meyer

2003-01-01

255

An Heuristic Method for GPS Surveying Stefka Fidanova  

E-print Network

, to analyze and improve the efficiency of the design of Global Positioning System (GPS) surveying networks of computational effort. The Global Positioning System is a satellite-based radio-navigation system that permits. The most widely known space systems are: the American Global Positioning System (GPS), the Russian GLObal

Fidanova, Stefka

256

A method for mapping corn using the US Geological Survey 1992 National Land Cover Dataset  

USGS Publications Warehouse

Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin's lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type. Corn requires the highest application of nitrogen fertilizer of crops grown in the Midwest US. We developed a method to refine the US Geological Survey National Land Cover Dataset (NLCD) (including map and original Landsat images) to distinguish corn from other crops. Overall average agreement between the resulting corn and other row crops class and ground reference data was 0.79 kappa coefficient with individual Landsat images ranging from 0.46 to 0.93 kappa. The highest accuracies occurred in Regions where corn was the single dominant crop (greater than 80.0%) and the crop vegetation conditions at the time of image acquisition were optimum for separation of corn from all other crops. Factors that resulted in lower accuracies included the accuracy of the NLCD map, accuracy of corn areal estimates, crop mixture, crop condition at the time of Landsat overpass, and Landsat scene anomalies. ?? 2006 Elsevier B.V. All rights reserved.

Maxwell, S.K.; Nuckols, J.R.; Ward, M.H.

2006-01-01

257

Gap interpolation by inpainting methods: Application to ground and space-based asteroseismic data  

NASA Astrophysics Data System (ADS)

In asteroseismology, the observed time series often suffers from incomplete time coverage due to gaps. The presence of periodic gaps may generate spurious peaks in the power spectrum that limit the analysis of the data. Various methods have been developed to deal with gaps in time series data. However, it is still important to improve these methods to be able to extract all the possible information contained in the data. In this paper, we propose a new approach to handling the problem, the so-called inpainting method. This technique, based on a prior condition of sparsity, enables the gaps in the data to be judiciously fill-in thereby preserving the asteroseismic signal as far as possible. The impact of the observational window function is reduced and the interpretation of the power spectrum simplified. This method is applied on both ground- and space-based data. It appears that the inpainting technique improves the detection and estimation of the oscillation modes. Additionally, it can be used to study very long time series of many stars because it is very fast to compute. For a time series of 50 days of CoRoT-like data, it allows a speed-up factor of 1000, if compared to methods with the same accuracy.

Pires, Sandrine; Mathur, Savita; García, Rafael A.; Ballot, Jérôme; Stello, Dennis; Sato, Kumiko

2015-02-01

258

Thermodynamic ground state of MgB{sub 6} predicted from first principles structure search methods  

SciTech Connect

Crystalline structures of magnesium hexaboride, MgB{sub 6}, were investigated using unbiased structure searching methods combined with first principles density functional calculations. An orthorhombic Cmcm structure was predicted as the thermodynamic ground state of MgB{sub 6}. The energy of the Cmcm structure is significantly lower than the theoretical MgB{sub 6} models previously considered based on a primitive cubic arrangement of boron octahedra. The Cmcm structure is stable against the decomposition to elemental magnesium and boron solids at atmospheric pressure and high pressures up to 18.3 GPa. A unique feature of the predicted Cmcm structure is that the boron atoms are clustered into two forms: localized B{sub 6} octahedra and extended B{sub ?} ribbons. Within the boron ribbons, the electrons are delocalized and this leads to a metallic ground state with vanished electric dipoles. The present prediction is in contrast to the previous proposal that the crystalline MgB{sub 6} maintains a semiconducting state with permanent dipole moments. MgB{sub 6} is estimated to have much weaker electron-phonon coupling compared with that of MgB{sub 2}, and therefore it is not expected to be able to sustain superconductivity at high temperatures.

Wang, Hui [State Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China) [State Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); LeBlanc, K. A. [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)] [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Gao, Bo [State Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China)] [State Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Yao, Yansun, E-mail: yansun.yao@usask.ca [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada) [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Canadian Light Source, Saskatoon, Saskatchewan S7N 0X4 (Canada)

2014-01-28

259

A Validation of Extraction Methods for Noninvasive Sampling of Glucocorticoids in Free-Living Ground Squirrels  

PubMed Central

Fecal hormone assays provide a powerful tool for noninvasive monitoring of endocrine status in wild animals. In this study we validated a protocol for extracting and measuring glucocorticoids in free-living and captive Belding’s ground squirrels (Spermophilus beldingi). We first compared two commonly used extraction protocols to determine which performed better with commercially available antibodies. We next verified the preferred extraction method by correlating circulating and fecal glucocorticoid measures from a group of individuals over time. For this comparison, we used both a cortisol and a corticosterone antibody to determine which had greater affinity to the fecal metabolites. Cortisol was the primary circulating glucocorticoid, but both hormones were present in well above detectable concentrations in the blood, which does not occur in other sciurids. In addition, the cortisol antibody showed greater binding with the fecal extracts than did the corticosterone antibody. Finally, we used adrenocorticotropic hormone and dexamethasone challenges to demonstrate that changes in adrenal functioning are reflected in changing fecal corticoid levels. These results suggest that our extraction protocol provides a fast, reliable assay of stress hormones in free-living ground squirrels without the confounding influence of short-term rises in glucocorticoid concentrations caused by handling and restraint stress and that it can facilitate ecological and evolutionary studies of stress in wild species. PMID:16228945

Mateo, Jill M.; Cavigelli, Sonia A.

2008-01-01

260

Methods for Using Ground-Water Model Predictions to Guide Hydrogeologic Data Collection, with Applications to the Death Valley Regional Ground-Water Flow System  

SciTech Connect

Calibrated models of ground-water systems can provide substantial information for guiding data collection. This work considers using such models to guide hydrogeologic data collection for improving model predictions, by identifying model parameters that are most important to the predictions. Identification of these important parameters can help guide collection of field data about parameter values and associated flow-system features that can lead to improved predictions. Methods for identifying parameters important to predictions include prediction scaled sensitivities (PSS), which account for uncertainty on individual parameters as well as prediction sensitivity to parameters, and a new ''value of improved information'' (VOII) method, which includes the effects of parameter correlation in addition to individual parameter uncertainty and prediction sensitivity. The PSS and VOII methods are demonstrated using a model of the Death Valley regional ground-water flow system. The predictions of interest are advective-transport paths originating at sites of past underground nuclear testing. Results show that for two paths evaluated, the most important parameters include a subset of five or six of the 23 defined model parameters. Some of the parameters identified as most important are associated with flow-system attributes that do not lie in the immediate vicinity of the paths. Results also indicate that the PSS and VOII methods can identify different important parameters. Because the methods emphasize somewhat different criteria for parameter importance, it is suggested that parameters identified by both methods be carefully considered in subsequent data collection efforts aimed at improving model predictions.

Claire R. Tiedeman; M.C. Hill; F.A. D'Agnese; C.C. Faunt

2001-07-31

261

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Ground water source microbial monitoring and analytical...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2010-07-01

262

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Ground water source microbial monitoring and analytical...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2011-07-01

263

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Ground water source microbial monitoring and analytical...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2013-07-01

264

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Ground water source microbial monitoring and analytical...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Ground Water Rule §...

2014-07-01

265

Method for Studying a Human Ecology: An Adaptation of the Grounded Theory Tradition.  

ERIC Educational Resources Information Center

Constructivist grounded theory is focused on discovery through understanding data in a human ecology. The procedures outlined in this paper are designed to guide the beginning theorist through the process of creating a theory grounded in data that is a product of the human ecology under study. These new procedures extend grounded theory, providing…

McCaslin, Mark L.; Scott, Karen Wilson

266

Prediction of ground vibration from trains using the wavenumber finite and boundary element methods  

Microsoft Academic Search

Ground vibration is an important aspect of the environmental impact of rail traffic. Vibration from about 2–200Hz is caused by trains moving on the ground surface or in tunnels. The wave field thus created must be modelled in three dimensions because of the excitation under each axle and the movement of the train. For arbitrary geometry of structures and ground

X. Sheng; C. J. C. Jones; D. J. Thompson

2006-01-01

267

The Tong Ren Healing Method: A Survey Study  

Microsoft Academic Search

Tong Ren (TR) is an untested energy healing modality with anecdotally-reported effectiveness for a variety of disorders. Study objective: To describe participant reports of effectiveness and safety. Design: Cross-sectional, anonymous survey. Setting: Weekly group sessions in the Northeast US. Participants: Adults attending group sessions. Measures: Changes in conditions attributed to TR. Results: Response rate 89% (n = 265). Cancer (30.6%),

Amy M. Sullivan; Susan Bauer-Wu; Michael Miovic

2009-01-01

268

Mapping of Lophelia reefs in Norway: experiences and survey methods  

Microsoft Academic Search

The Institute of Marine Research commenced a program for mapping and assessment of Lophelia reefs in 1997. It was initiated by reports from fishermen claiming that bottom trawling damaged deep-water coral reefs. The\\u000a strategy was to survey coral sites reported in the literature and by the fishermen. This has provided an extensive database\\u000a of coral occurrences, both damaged and undamaged

Jan Helge Fosså; Björn Lindberg; Ole Christensen; Tomas Lundälv; Ingvald Svellingen; Pål B. Mortensen; John Alvsvåg

269

Detection of conduit-controlled ground-water flow in northwestern Puerto Rico using aerial photograph interpretation and geophysical methods  

USGS Publications Warehouse

The development potential of ground-water resources in the karst limestone of northwestern Puerto Rico, in an area extending from the Río Camuy to Aguadilla, is uncertain as a result of limited knowledge of the location of areas where a high density of cavities (interconnected fractures, conduits, and other dissolution features) might suggest the occurrence of high water yields. The presence in northwestern Puerto Rico of numerous coastal submarine springs, cavernous porosity in some of the wells, and rivers with entrenched and underground paths, indicate that it is probable that water-bearing, subterranean interconnected cavities occur in the area between the Río Camuy and Aguadilla. The number of exploratory wells needed to determine the location of these conduits or zones of enhanced secondary porosity could be substantially reduced if more information were available about the location of these subterranean features, greatly reducing the drilling costs associated with a trial-and-error exploratory process. A 3-year study was conducted by the U.S. Geological Survey, in cooperation with the Puerto Rico Aqueduct and Sewer Authority, to detect the presence of cavities that might suggest the occurrence of conduit-controlled groundwater flow. Aerial photographs, geologic and topographic maps, and field reconnaissance were used to identify such linear terrain features as ridges, entrenched canyons, and fracture traces. Natural potential and gravity geophysical methods were also used. The following sites were selected for the aerial photograph interpretation and geophysical testing: Caimital Bajo uplands and former Ramey Air Force Base in Aguadilla; Quebrada de los Cedros between Aguadilla and Isabela; the University of Puerto Rico Agricultural Experiment Station, Otilio dairy farm, and Pozo Brujo in Isabela; the Monte Encantado area in Moca and Isabela; and the Rio Camuy cave system in Hatillo and Camuy. In general, the degree of success varied with site and the geophysical method used. At some sites such as Pozo Brujo, the University of Puerto Rico Agricultural Experiment Station, and Monte Encantado area, natural potential anomalies strongly suggest the existence of conduits with flowing water. At most sites, however, the results obtained did not clearly reveal the presence of subsurface cavities that might be associated with the occurrence of conduit-controlled ground-water flow. Sites such as the University of Puerto Rico Agricultural Experiment Station, Pozo Brujo, and Quebrada de los Cedros warrant a more detailed analysis, including a test well drilling phase to confirm the presence of suspected high-yield water-bearing zones.

Rodríguez-Martínez, Jesús; Richards, Ronald T.

2000-01-01

270

Concordance and discordance of sequence survey methods for molecular epidemiology.  

PubMed

The post-genomic era is characterized by the direct acquisition and analysis of genomic data with many applications, including the enhancement of the understanding of microbial epidemiology and pathology. However, there are a number of molecular approaches to survey pathogen diversity, and the impact of these different approaches on parameter estimation and inference are not entirely clear. We sequenced whole genomes of bacterial pathogens, Burkholderia pseudomallei, Yersinia pestis, and Brucella spp. (60 new genomes), and combined them with 55 genomes from GenBank to address how different molecular survey approaches (whole genomes, SNPs, and MLST) impact downstream inferences on molecular evolutionary parameters, evolutionary relationships, and trait character associations. We selected isolates for sequencing to represent temporal, geographic origin, and host range variability. We found that substitution rate estimates vary widely among approaches, and that SNP and genomic datasets yielded different but strongly supported phylogenies. MLST yielded poorly supported phylogenies, especially in our low diversity dataset, i.e., Y. pestis. Trait associations showed that B. pseudomallei and Y. pestis phylogenies are significantly associated with geography, irrespective of the molecular survey approach used, while Brucella spp. phylogeny appears to be strongly associated with geography and host origin. We contrast inferences made among monomorphic (clonal) and non-monomorphic bacteria, and between intra- and inter-specific datasets. We also discuss our results in light of underlying assumptions of different approaches. PMID:25737810

Castro-Nallar, Eduardo; Hasan, Nur A; Cebula, Thomas A; Colwell, Rita R; Robison, Richard A; Johnson, W Evan; Crandall, Keith A

2015-01-01

271

Concordance and discordance of sequence survey methods for molecular epidemiology  

PubMed Central

The post-genomic era is characterized by the direct acquisition and analysis of genomic data with many applications, including the enhancement of the understanding of microbial epidemiology and pathology. However, there are a number of molecular approaches to survey pathogen diversity, and the impact of these different approaches on parameter estimation and inference are not entirely clear. We sequenced whole genomes of bacterial pathogens, Burkholderia pseudomallei, Yersinia pestis, and Brucella spp. (60 new genomes), and combined them with 55 genomes from GenBank to address how different molecular survey approaches (whole genomes, SNPs, and MLST) impact downstream inferences on molecular evolutionary parameters, evolutionary relationships, and trait character associations. We selected isolates for sequencing to represent temporal, geographic origin, and host range variability. We found that substitution rate estimates vary widely among approaches, and that SNP and genomic datasets yielded different but strongly supported phylogenies. MLST yielded poorly supported phylogenies, especially in our low diversity dataset, i.e., Y. pestis. Trait associations showed that B. pseudomallei and Y. pestis phylogenies are significantly associated with geography, irrespective of the molecular survey approach used, while Brucella spp. phylogeny appears to be strongly associated with geography and host origin. We contrast inferences made among monomorphic (clonal) and non-monomorphic bacteria, and between intra- and inter-specific datasets. We also discuss our results in light of underlying assumptions of different approaches. PMID:25737810

Hasan, Nur A.; Cebula, Thomas A.; Colwell, Rita R.; Robison, Richard A.; Johnson, W. Evan; Crandall, Keith A.

2015-01-01

272

A survey of numerical methods for stochastic differential equations  

Microsoft Academic Search

The development of numerical methods for stochastic differential equations has intensified over the past decade. The earliest methods were usually heuristic adaptations of deterministic methods, but were found to have limited accuracy regardless of the order of the original scheme. A stochastic counterpart of the Taylor formula now provides a framework for the systematic investigation of numerical methods for stochastic

P. E. Kloeden; E. Platen

1989-01-01

273

A survey on evaluation methods for image segmentation  

Microsoft Academic Search

This paper studies different methods proposed so far for segmentation evaluation. Most methods can be classified into three groups: the analytical, the empirical goodness and the empirical discrepancy groups. Each group has its own characteristics. After a brief description of each method in every group, some comparative discussions about different method groups are first carried out. An experimental comparison for

Y. J. Zhang

1996-01-01

274

Effects of land use on ground-water quality in central Florida - Preliminary results: U. S. Geological Survey Toxic Waste - Ground-Water Contamination Program  

SciTech Connect

Activities of man in areas of recharge to the Floridian aquifer system that may be affecting groundwater quality include: (1) the use of drainage wells for stormwater disposal in urban areas, (2) the use of pesticides and fertilizers in citrus groves, and (3) the mining and processing of phosphate ore in mining areas. Preliminary findings about the impact of these land uses on groundwater quality are presented. Drainage wells convey excess urban stormwater directly to the Upper Floridian aquifer. The volatile organic compounds are the most common contaminants in ground water. Trace elements such as chromium and lead are entering the aquifer but their movement is apparently attenuated by precipitation reactions associated with high pH or by cation-exchange reactions. Among the trace elements and organic chemicals, most ground-water contamination in citrus production areas is caused by pesticide; other contaminants include benzene, toluene, naphthalene, and indene compounds. In the phosphate mining area, constituents of concern are arsenic, selenium, and mercury, and secondarily lead, chromium, cadmium, and others. Organic compounds such as fluorene, naphthalene, di-n-butyl phthalate, alkylated benzenes and naphthalenes, and indene compounds also are entering groundwater. 29 refs., 13 figs., 16 tabs.

Rutledge, A.T.

1987-01-01

275

Integrating case study and survey research methods: an example in information systems  

Microsoft Academic Search

The case for combining research methods generally, and more specifically that for combining qualitative and quantitative methods, is strong. Yet, research designs that extensively integrate both fieldwork (e.g. case studies) and survey research are rare. Moreover, some journals tend tacitly to specialize by methodology thereby encouraging purity of method. The multi-method model of research while not new, has not been

Guy G. Gable

1994-01-01

276

Survey of numerical methods for solution of large systems of linear equations for electromagnetic field problems  

Microsoft Academic Search

A number of the popular methods for the solution of large matrix equations are surveyed in order to find an efficient method suitable for both electromagnetic scattering and radiation problems and system identification problems. It is argued that the application of the conjugate gradient method to the analysis of large bodies by the method of moments would yield stable, reliable,

T. K. Sarkar; K. R. Siarkiewicz; R. F. Stratton

1981-01-01

277

Image Segmentation Evaluation: A Survey of Unsupervised Methods Hui Zhang a  

E-print Network

Image Segmentation Evaluation: A Survey of Unsupervised Methods Hui Zhang a , Jason E. Fritts b. To date, the most common method for evaluating the effectiveness of a segmentation method is subjective-segmented or pre-processed reference image. Evaluation methods that require user assistance, such as subjective

Fritts, Jason

278

A comparison of mail, fax and web-based survey methods  

Microsoft Academic Search

This study compares mail, fax and web-based surveys in a university setting for response speed, response rate and costs. The survey was distributed to 300 hospitality professors randomly chosen from the Council on Hotel, Restaurant, and Institutional Education members listed in the organisation's online directory as of April 2000. It was found that the fastest method was fax, with an

Cihan Cobanoglu; Bill Warde; Patrick J. Moreo

2001-01-01

279

Teaching and Assessment Methods in Undergraduate Economics: A Fourth National Quinquennial Survey  

ERIC Educational Resources Information Center

Surveys in 1995, 2000, 2005, and 2010 investigated teaching and assessment methods in different undergraduate courses. In this article, the authors offer basic results from the 2010 survey. "Chalk and talk" remains the dominant teaching style, but there were drops in mean (although not median) values for those pedagogies and some growth in the use…

Watts, Michael; Schaur, Georg

2011-01-01

280

Development, methods, and response characteristics of the 1986 National Mortality Followback Survey.  

PubMed

This report describes the methods employed in the 1986 National Mortality Followback Survey. This survey is based on information obtained from relatives of decedents and from health care facilities used by the decedents in their last year of life. PMID:8328133

Seeman, I; Poe, G S; Powell-Griner, E

1993-05-01

281

A SUMMARY OF THE INTERLABORATORY SOURCE PERFORMANCE SURVEYS FOR EPA REFERENCE METHODS 6 AND 7 - 1977  

EPA Science Inventory

This report summarizes the 1977 results of a source methods survey program conducted by the Quality Assurance Branch of the Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency. As part of these surveys, test solutions prepared as internal quality...

282

Sampling Methods and Construction of Weights 2007 Alameda County Homeless Survey  

E-print Network

Sampling Methods and Construction of Weights for the 2007 Alameda County Homeless Survey by Thomas;1 1. OVERVIEW 1.1 Background of the Study The 2007 Alameda County Homeless Survey was designed to provide an estimate of the number of unsheltered homeless persons in Alameda County and to study

Sekhon, Jasjeet S.

283

Sampling Methods and Construction of Weights 2009 Alameda County Homeless Survey  

E-print Network

Sampling Methods and Construction of Weights for the 2009 Alameda County Homeless Survey by Thomas;1 1. OVERVIEW 1.1 Background of the Study The 2009 Alameda County Homeless Survey was designed to provide an estimate of the number of unsheltered homeless persons in Alameda County and to study

Sekhon, Jasjeet S.

284

New electromagnetic surveying/ranging method for drilling parallel horizontal twin wells  

SciTech Connect

An electromagnetic source was used in conjunction with a measurement-while-drilling (MWD) survey instrument to drill two parallel horizontal wells with a vertical separation of 9 {+-} 2 m over a length of 600 m in Amoco`s Wolf Lake field for steam-assisted gravity drainage of heavy oil. Existing wellbore survey methods are incapable of this level of precision because of cumulative survey error and associated position uncertainty. Using this new electromagnetic ranging technique, the twin wells were placed with better than 10 times the accuracy of gyro surveys.

Kuckes, A.F.; Hay, R.T.; McMahon, J.; Nord, A.G.; Schilling, D.A.; Morden, J.

1996-06-01

285

New electromagnetic surveying/ranging method for drilling parallel horizontal twin wells  

SciTech Connect

An electromagnetic source was used in conjunction with an MWD survey instrument to drill two parallel horizontal wells, with a vertical separation of 9{plus_minus}2 meters, over a length of 600 meters in Amoco`s Wolf Lake field for steam assisted gravity drainage of heavy oil. Existing wellbore survey methods are incapable of this level of precision due to cumulative survey error and associated position uncertainty. Using this new electromagnetic ranging technique, the twin wells were placed with better than 10 times the accuracy of gyro surveys.

Kuckes, A.F.; Hay, R.T.; McMahon, J. [and others

1995-12-31

286

Finding a Fox: An Evaluation of Survey Methods to Estimate Abundance of a Small Desert Carnivore  

PubMed Central

The status of many carnivore species is a growing concern for wildlife agencies, conservation organizations, and the general public. Historically, kit foxes (Vulpes macrotis) were classified as abundant and distributed in the desert and semi-arid regions of southwestern North America, but is now considered rare throughout its range. Survey methods have been evaluated for kit foxes, but often in populations where abundance is high and there is little consensus on which technique is best to monitor abundance. We conducted a 2-year study to evaluate four survey methods (scat deposition surveys, scent station surveys, spotlight survey, and trapping) for detecting kit foxes and measuring fox abundance. We determined the probability of detection for each method, and examined the correlation between the relative abundance as estimated by each survey method and the known minimum kit fox abundance as determined by radio-collared animals. All surveys were conducted on 15 5-km transects during the 3 biological seasons of the kit fox. Scat deposition surveys had both the highest detection probabilities (p?=?0.88) and were most closely related to minimum known fox abundance (r2?=?0.50, P?=?0.001). The next best method for kit fox detection was the scent station survey (p?=?0.73), which had the second highest correlation to fox abundance (r2?=?0.46, P<0.001). For detecting kit foxes in a low density population we suggest using scat deposition transects during the breeding season. Scat deposition surveys have low costs, resilience to weather, low labor requirements, and pose no risk to the study animals. The breeding season was ideal for monitoring kit fox population size, as detections consisted of the resident population and had the highest detection probabilities. Using appropriate monitoring techniques will be critical for future conservation actions for this rare desert carnivore. PMID:25148102

Dempsey, Steven J.; Gese, Eric M.; Kluever, Bryan M.

2014-01-01

287

Degeneracy in interior point methods for linear programming: a survey  

Microsoft Academic Search

The publication of Karmarkar's paper has resulted in intense research activity into Interior Point Methods (IPMs) for linear programming. Degeneracy is present in most real-life problems and has always been an important issue in linear programming, especially in the Simplex method. Degeneracy is also an important issue in IPMs. However, the difficulties are different in the two methods. In this

O. Giiler; D. den Hertog; C. Roos; T. Terlaky; T. Tsuchiya

1993-01-01

288

A Survey of Algebraic Multilevel Iteration (AMLI) Methods  

Microsoft Academic Search

For the solution by preconditioned conjugate gradient methods of symmetric positive definite equations as arising in boundary value problems we consider preconditioning methods of AMLI type. Particular attention is devoted to providing methods of optimal order of computational complexity which in addition promise to be robust, i.e. with a convergence rate which is bounded above independently of size of discretization

Owe Axelsson

2003-01-01

289

The Swift UVOT Stars Survey. I. Methods and Test Clusters  

NASA Astrophysics Data System (ADS)

We describe the motivations and background of a large survey of nearby stellar populations using the Ultraviolet Optical Telescope (UVOT) on board the Swift Gamma-Ray Burst Mission. UVOT, with its wide field, near-UV sensitivity, and 2.?3 spatial resolution, is uniquely suited to studying nearby stellar populations and providing insight into the near-UV properties of hot stars and the contribution of those stars to the integrated light of more distant stellar populations. We review the state of UV stellar photometry, outline the survey, and address problems specific to wide- and crowded-field UVOT photometry. We present color-magnitude diagrams of the nearby open clusters M67, NGC 188, and NGC 2539, and the globular cluster M79. We demonstrate that UVOT can easily discern the young- and intermediate-age main sequences, blue stragglers, and hot white dwarfs, producing results consistent with previous studies. We also find that it characterizes the blue horizontal branch of M79 and easily identifies a known post-asymptotic giant branch star.

Siegel, Michael H.; Porterfield, Blair L.; Linevsky, Jacquelyn S.; Bond, Howard E.; Holland, Stephen T.; Hoversten, Erik A.; Berrier, Joshua L.; Breeveld, Alice A.; Brown, Peter J.; Gronwall, Caryl A.

2014-12-01

290

Application of a method for the automatic detection and Ground-Based Velocity Track Display (GBVTD) analysis of a tornado crossing the Hong Kong International Airport  

NASA Astrophysics Data System (ADS)

A weak tornado with a maximum Doppler velocity shear of about 40 m s - 1 moved across the Hong Kong International Airport (HKIA) during the evening of 20 May 2002. The tornado caused damage equivalent to F0 on the Fujita Scale, based on a damage survey. The Doppler velocity data from the Hong Kong Terminal Doppler Weather Radar (TDWR) are studied using the Ground-Based Velocity Track Display (GBVTD) method of single Doppler analysis. The GBVTD analysis is able to clearly depict the development and decay of the tornado though it appears to underestimate its magnitude. In the pre-tornadic state, the wind field is characterized by inflow toward the center near the ground and upward motion near the center. When the tornado attains its maximum strength, an eye-like structure with a downdraft appears to form in the center. Several minutes later the tornado begins to decay and outflow dominates at low levels. Assuming cyclostrophic balance, the pressure drop 200 m from the center of the tornado at its maximum strength is calculated to be about 6 hPa. To estimate the maximum ground-relative wind speed of the tornado, the TDWR's Doppler velocities are adjusted for the ratio of the sample-volume size of the radar and the radius of the tornado, resulting in a peak wind speed of 28 m s - 1 , consistent with the readings from a nearby ground-based anemometers and the F0 damage observed. An automatic tornado detection algorithm based on Doppler velocity difference (delta-V) and temporal and spatial continuity is applied to this event. The locations and the core flow radii of the tornado as determined by the automatic method and by subjective analysis agree closely.

Chan, P. W.; Wurman, J.; Shun, C. M.; Robinson, P.; Kosiba, K.

2012-03-01

291

Petrophysical analysis of geophysical logs of the National Drilling Company-U.S. Geological Survey ground-water research project for Abu Dhabi Emirate, United Arab Emirates  

USGS Publications Warehouse

A program of borehole-geophysical logging was implemented to supply geologic and geohydrologic information for a regional ground-water investigation of Abu Dhabi Emirate. Analysis of geophysical logs was essential to provide information on geohydrologic properties because drill cuttings were not always adequate to define lithologic boundaries. The standard suite of logs obtained at most project test holes consisted of caliper, spontaneous potential, gamma ray, dual induction, microresistivity, compensated neutron, compensated density, and compensated sonic. Ophiolitic detritus from the nearby Oman Mountains has unusual petrophysical properties that complicated the interpretation of geophysical logs. The density of coarse ophiolitic detritus is typically greater than 3.0 grams per cubic centimeter, porosity values are large, often exceeding 45 percent, and the clay fraction included unusual clays, such as lizardite. Neither the spontaneous-potential log nor the natural gamma-ray log were useable clay indicators. Because intrinsic permeability is a function of clay content, additional research in determining clay content was critical. A research program of geophysical logging was conducted to determine the petrophysical properties of the shallow subsurface formations. The logging included spectral-gamma and thermal-decay-time logs. These logs, along with the standard geophysical logs, were correlated to mineralogy and whole-rock chemistry as determined from sidewall cores. Thus, interpretation of lithology and fluids was accomplished. Permeability and specific yield were calculated from geophysical-log data and correlated to results from an aquifer test. On the basis of results from the research logging, a method of lithologic and water-resistivity interpretation was developed for the test holes at which the standard suite of logs were obtained. In addition, a computer program was developed to assist in the analysis of log data. Geohydrologic properties were estimated, including volume of clay matrix, volume of matrix other than clay, density of matrix other than clay, density of matrix, intrinsic permeability, specific yield, and specific storage. Geophysical logs were used to (1) determine lithology, (2) correlate lithologic and permeable zones, (3) calibrate seismic reprocessing, (4) calibrate transient-electromagnetic surveys, and (5) calibrate uphole-survey interpretations. Logs were used at the drill site to (1) determine permeability zones, (2) determine dissolved-solids content, which is a function of water resistivity, and (3) design wells accordingly. Data and properties derived from logs were used to determine transmissivity and specific yield of aquifer materials.

Jorgensen, Donald G.; Petricola, Mario

1994-01-01

292

An historical survey of computational methods in optimal control.  

NASA Technical Reports Server (NTRS)

Review of some of the salient theoretical developments in the specific area of optimal control algorithms. The first algorithms for optimal control were aimed at unconstrained problems and were derived by using first- and second-variation methods of the calculus of variations. These methods have subsequently been recognized as gradient, Newton-Raphson, or Gauss-Newton methods in function space. A much more recent addition to the arsenal of unconstrained optimal control algorithms are several variations of conjugate-gradient methods. At first, constrained optimal control problems could only be solved by exterior penalty function methods. Later algorithms specifically designed for constrained problems have appeared. Among these are methods for solving the unconstrained linear quadratic regulator problem, as well as certain constrained minimum-time and minimum-energy problems. Differential-dynamic programming was developed from dynamic programming considerations. The conditional-gradient method, the gradient-projection method, and a couple of feasible directions methods were obtained as extensions or adaptations of related algorithms for finite-dimensional problems. Finally, the so-called epsilon-methods combine the Ritz method with penalty function techniques.

Polak, E.

1973-01-01

293

A survey of design methods for failure detection in dynamic systems  

NASA Technical Reports Server (NTRS)

A number of methods for the detection of abrupt changes (such as failures) in stochastic dynamical systems were surveyed. The class of linear systems were emphasized, but the basic concepts, if not the detailed analyses, carry over to other classes of systems. The methods surveyed range from the design of specific failure-sensitive filters, to the use of statistical tests on filter innovations, to the development of jump process formulations. Tradeoffs in complexity versus performance are discussed.

Willsky, A. S.

1975-01-01

294

Elevation Change of Drangajokull, Iceland, from Cloud-Cleared ICESat Repeat Profiles and GPS Ground-Survey Data  

NASA Technical Reports Server (NTRS)

Located on the Vestfirdir Northwest Fjords), DrangaJokull is the northernmost ice map in Iceland. Currently, the ice cap exceeds 900 m in elevation and covered an area of approx.l46 sq km in August 2004. It was about 204 sq km in area during 1913-1914 and so has lost mass during the 20th century. Drangajokull's size and accessibility for GPS surveys as well as the availability of repeat satellite altimetry profiles since late 2003 make it a good subject for change-detection analysis. The ice cap was surveyed by four GPS-equipped snowmobiles on 19-20 April 2005 and has been profiled in two places by Ice, Cloud. and land Elevation Satellite (ICESat) 'repeat tracks,' fifteen times from late to early 2009. In addition, traditional mass-balance measurements have been taken seasonally at a number of locations across the ice cap and they show positive net mass balances in 2004/2005 through 2006/2007. Mean elevation differences between the temporally-closest ICESat profiles and the GPS-derived digital-elevation model (DEM)(ICESat - DEM) are about 1.1 m but have standard deviations of 3 to 4 m. Differencing all ICESat repeats from the DEM shows that the overall elevation difference trend since 2003 is negative with losses of as much as 1.5 m/a from same season to same season (and similar elevation) data subsets. However, the mass balance assessments by traditional stake re-measurement methods suggest that the elevation changes where ICESat tracks 0046 and 0307 cross Drangajokull are not representative of the whole ice cap. Specifically, the area has experienced positive mass balance years during the time frame when ICESat data indicates substantial losses. This analysis suggests that ICESat-derived elevations may be used for multi-year change detection relative to other data but suggests that large uncertainties remain. These uncertainties may be due to geolocation uncertainty on steep slopes and continuing cloud cover that limits temporal and spatial coverage across the area.

Shuman, Christopher A.; Sigurdsson, Oddur; Williams, Richard, Jr.; Hall, Dorothy K.

2009-01-01

295

Determining concentrations of 2-bromoallyl alcohol and dibromopropene in ground water using quantitative methods  

USGS Publications Warehouse

A method for determining levels of 2-bromoallyl alcohol and 2,3-dibromopropene from ground-water samples using liquid/liquid extraction followed by gas chromatography/mass spectrometry is described. Analytes were extracted from the water using three aliquots of dichloromethane. The aliquots were combined and reduced in volume by rotary evaporation followed by evaporation using a nitrogen stream. The extracts were analyzed by capillary-column gas chromatography/mass spectrometry in the full-scan mode. Estimated method detection limits were 30 nanograms per liter for 2-bromoallyl alcohol and 10 nanograms per liter for 2,3-dibromopropene. Recoveries were determined by spiking three matrices at two concentration levels (0.540 and 5.40 micrograms per liter for 2-bromoallyl alcohol; and 0.534 and 5.34micro-grams per liter for dibromopropene). For seven replicates of each matrix at the high concentration level, the mean percent recoveries ranged from 43.9 to 64.9 percent for 2-bromoallyl alcohol, and from 87.5 to 99.3 percent for dibromopropene. At the low concentration level, the mean percent recoveries ranged from 43.8 to 95.2 percent for 2-bromoallyl alcohol, and from 71.3 to 84.9 percent for dibromopropene.

Panshin, Sandra Y.

1997-01-01

296

Comparison of visual survey and seining methods for estimating abundance of an endangered, benthic stream fish  

USGS Publications Warehouse

We compared visual survey and seining methods for estimating abundance of endangered Okaloosa darters, Etheostoma okaloosae, in 12 replicate stream reaches during August 2001. For each 20-m stream reach, two divers systematically located and marked the position of darters and then a second crew of three to five people came through with a small-mesh seine and exhaustively sampled the same area. Visual surveys required little extra time to complete. Visual counts (24.2 ?? 12.0; mean ?? one SD) considerably exceeded seine captures (7.4 ?? 4.8), and counts from the two methods were uncorrelated. Visual surveys, but not seines, detected the presence of Okaloosa darters at one site with low population densities. In 2003, we performed a depletion removal study in 10 replicate stream reaches to assess the accuracy of the visual survey method. Visual surveys detected 59% of Okaloosa darters present, and visual counts and removal estimates were positively correlated. Taken together, our comparisons indicate that visual surveys more accurately and precisely estimate abundance of Okaloosa darters than seining and more reliably detect presence at low population densities. We recommend evaluation of visual survey methods when designing programs to monitor abundance of benthic fishes in clear streams, especially for threatened and endangered species that may be sensitive to handling and habitat disturbance. ?? 2007 Springer Science+Business Media, Inc.

Jordan, F.; Jelks, H.L.; Bortone, S.A.; Dorazio, R.M.

2008-01-01

297

Analytical study of STOL Aircraft in ground effect. Part 1: Nonplanar, nonlinear wing/jet lifting surface method  

NASA Technical Reports Server (NTRS)

A nonlinear, nonplanar three dimensional jet flap analysis, applicable to the ground effect problem, is presented. Lifting surface methodology is developed for a wing with arbitrary planform operating in an inviscid and incompressible fluid. The classical, infintely thin jet flap model is employed to simulate power induced effects. An iterative solution procedure is applied within the analysis to successively approximate the jet shape until a converged solution is obtained which closely satisfies jet and wing boundary conditions. Solution characteristics of the method are discussed and example results are presented for unpowered, basic powered and complex powered configurations. Comparisons between predictions of the present method and experimental measurements indicate that the improvement of the jet with the ground plane is important in the analyses of powered lift systems operating in ground proximity. Further development of the method is suggested in the areas of improved solution convergence, more realistic modeling of jet impingement and calculation efficiency enhancements.

Shollenberger, C. A.; Smyth, D. N.

1978-01-01

298

A survey of numerical methods for transient eddy current problems  

Microsoft Academic Search

The efficiencies of different time-stepping schemes and associated algebraic system solvers for transient eddy current computations are assessed. For 2-D problems, the direct methods nested dissection (ND) and quotient minimum degree (QMD) are shown to be preferable to the incomplete Cholesky conjugate-gradient (ICCG) method, provided enough memory is available. The multilevel preconditions (MP) method is highly efficient for magnetically homogeneous

I. A. Tsukerman; A. Konrad; G. Bedrosian; M. V. K. Chari

1993-01-01

299

A survey of census bureau population projection methods  

Microsoft Academic Search

Population projections methods of the U.S. Census Bureau draw upon several different traditions of forecasting: demographic accounting, judgmental, time series, deterministic, and explanatory. This paper reviews each of the forecasting traditions in population projections, describes the U.S. Census Bureau's current methods for national and state population projections, and proposes new hybrid approaches such as demographic-time series methods for national fertility

John F. Long; David Byron McMillen

1987-01-01

300

Gamma/hadron segregation for a ground based imaging atmospheric Cherenkov telescope using machine learning methods: Random Forest leads  

NASA Astrophysics Data System (ADS)

A detailed case study of ?-hadron segregation for a ground based atmospheric Cherenkov telescope is presented. We have evaluated and compared various supervised machine learning methods such as the Random Forest method, Artificial Neural Network, Linear Discriminant method, Naive Bayes Classifiers, Support Vector Machines as well as the conventional dynamic supercut method by simulating triggering events with the Monte Carlo method and applied the results to a Cherenkov telescope. It is demonstrated that the Random Forest method is the most sensitive machine learning method for ?-hadron segregation.

Sharma, Mradul; Nayak, Jitadeepa; Krishna Koul, Maharaj; Bose, Smarajit; Mitra, Abhas

2014-11-01

301

Aerothermodynamic methods for a Mars environmental survey Mars entry  

NASA Technical Reports Server (NTRS)

Computational fluid dynamics models for the thermodynamics and transport properties used in an equilibrium version of the Langley aerothermodynamics upwind relaxation algorithm (LAURA) for Mars atmospheric entries are described. In addition, the physical models used in a nonequilibrium version of LAURA for Mars-entry flows are described. Uncertainties exist in defining constants used in the transport properties for the equilibrium model and in many of the physical models for the nonequilibrium version. Solutions from the two codes using the best available constants are examined at the Mars-entry conditions characteristics of the Mars environmental survey mission. While the flowfields are near thermal equilibrium, chemical nonequilibrium effects are present in the entry cases examined. Convective heating at the stagnation point for these flows (assuming fully catalytic wall boundary conditions) is approximately 100 W/cm(exp 2). Radiative heating is negligible.

Mitcheltree, R. A.

1994-01-01

302

A survey of the effects of a fourth year Introduction to Research Methods course  

E-print Network

A survey of the effects of a fourth year Introduction to Research Methods course Vashti Galpin an introductory research methods Honours course to increase our students' exposure to research and to help them with the Honours research reports prior to the introduction of the research methods course have been alleviated. 1

Galpin, Vashti

303

A COMPARATIVE SURVEY OF ACTIVITY-BASED METHODS FOR INFORMATION SYSTEMS DEVELOPMENT  

E-print Network

A COMPARATIVE SURVEY OF ACTIVITY-BASED METHODS FOR INFORMATION SYSTEMS DEVELOPMENT Amanda Quek with which to analyse and understand human behaviour in context. AT-based methods for IS development may-based methods for IS development. The importance of considering contextual and social issues in IS development

304

A Comparison between Survey and Verbal Choice Methods of Identifying Potential Reinforcers among Employees  

ERIC Educational Resources Information Center

Two methods of assessing preference for stimuli (i.e., potential reinforcers) were compared for adult administrative assistant employees. During Phase 1, a survey method and a verbal choice method of assessing preference for 6 stimuli were administered. During Phase 2, a coupon system was used to determine which categories of stimuli actually…

Wilder, David A; Therrien, Kelly; Wine, Byron

2006-01-01

305

A (Revised) Survey of Approximate Methods for Solving Partially Observable Markov Decision Processes  

Microsoft Academic Search

Partially observable Markov decision processes (POMDPs) are inter- esting because they provide a general framework for learning in the pres- ence of multiple forms of uncertainty. We survey methods for learning within the POMDP framework. Because exact methods are intractable we concentrate on approximate methods. We explore two versions of the POMDP training problem: learning when a model of the

Douglas Aberdeen

306

Ground Gravity, Magnetic and Electromagnetic Surveys on a Crater on Basalt of Bajada del Diablo Astrobleme-Strewn Field  

NASA Astrophysics Data System (ADS)

With the aim of further investigate the circular structures from Bajada del Diablo, we carried out geophysics surveys and we conclude that the geophysical features could be satisfactorily explained assuming an extra-terrestrial projectile impact.

Acevedo, R. D.; Prezzi, C.; Orgeira, M. J.; Rocca, M.; Martínez, O.; Ponce, J. F.; Corbella, H.; Rabassa, J.; González-Guillot, M.; Subías, I.

2014-09-01

307

COMPARISON OF GEOSTATISTICAL METHODS FOR ESTIMATING VIRUS INACTIVATION RATES IN GROUND WATER  

EPA Science Inventory

Enteric viruses are responsible for a large number of ground-waterborne disease outbreaks every year. Septic tanks are the most frequently cited causes of ground-water contamination in disease outbreaks. Controlling the placement of septic tanks such that all viruses would be non...

308

Ground state correlations and mean field using the exp(S) method  

E-print Network

This document gives a detailed account of the terms used in the computation of the ground state mean field and the ground state correlations. While the general approach to this description is given in a separate paper (nucl-th/9802029) we give here the explicite expressions used.

Jochen H. Heisenberg; Bogdan Mihaila

1998-02-10

309

Evaluation of In-Service Education: A Survey of Methods  

ERIC Educational Resources Information Center

The following methods of evaluation of inservice programs are very briefly discussed: a) behavioral objectives; b) diagnosis; c) learner outcomes; d) effects on teachers; e) classroom observation, and f) questionnaires following inservice activity. (HMD)

Wehmeyer, Lillian M.

1974-01-01

310

Ground Penetrating Radar, a Method for Exploration and Monitoring of Coal Fires in China  

NASA Astrophysics Data System (ADS)

Due to the climate change it is a global task to fight against gas emission of coal fires. In China exists many burning coal seams which should be extinguished. A Chinese-German initiative tries to find new technologies and solutions to control these fires. Most of the fires are close to the surface in arid areas. In that case GPR is a possible geophysical method to get detailed information about the structure of the soil. Mining activities and the burning coal are leaving voids which collapse or still exist as dangerous areas. With GPR it is possible to detect voids and clefts. Crevices are potential paths for oxygen transport from the surface to the fire. The knowledge of these structures would help to extinguish the fire. The heat of the burning coal changes the permittivity and the conductivity of the rock. This affects the radar signal and makes it possible to separate burning zones from intact zones. Monitoring of the burning zones helps to find optimal solutions for fire extinguishing strategies. Several field campaigns were made in China. One campaign was in the province Xinjiang with a 50 MHz system from Mala on a steep dipping coal seam. Other campaigns were in the Inner Mongolia with 40 MHz to 200 MHz antennae from GSSI on shallow dipping coal seams. The experiences from these measurements will be shown. The surveys were collected in rough terrain. The data from the unshielded antennae contained a lot of effects coming through the air. The limits of detecting crevices with GPR will be demonstrated. Some parts of the measurements over burning coal were influenced by strong anomalies of the magnetization. Modeling of the radar signal helps at the interpretation. Parts of the interpretation from the surveys can be validated by the outcrop of the investigated structures. A spatial visualization of the results is the basis for discussions.

Gundelach, Volker

2010-05-01

311

Research of Stability Problems on Ankara-Konya High Speed Railway Line (Turkey) using Ground Penetrating Radar and Petrographical Methods  

NASA Astrophysics Data System (ADS)

The aim of the study is to research the stability problems according to rock properties and their discontinuities such as fractures, faults and karstic cavities on the new high-speed railway line between the capital city Ankara and the largest city Konya in Turkey. The Ankara-Konya high speed railway including a tunnel managed from The Turkish State Railways (TCDD). Geological surveys, polarizing microscope and confocal Raman spectrometry studies were used to determine rock properties. Ground penetrating radar (GPR) method was used to determine faults, fractures and karstic cavities. The railway line has been mainly constructed on inner Tauride Ocean suture of the Central Anatolia. The basement unit of the railway line mainly has been composed of ophiolitic complex of the inner Tauride Ocean. The main lithology of this ophiolitic complex has been formed by radiolarite, pelagic sediments, dolarite, gabbro, serpentinized peridotite and limestone blocks. The Jurassic alloctonous limestone which has been thrust on the ophiolitic complex. Neogene cover young units with minor amount of Alluvium deposits have been formed by the upper litholgy in the region. The serpentinite and altered radiolarite formation are formed by lubricous ground for the railway line in the region. A RAMAC CUII GPR system was used with a bi-static 100 MHz center band shielded antenna to acquire profile data. Totaly 35 km was surveyed on different parts of the railway line by considering the results of the geologic research and petrograpical studies. When we started to study, rail construction of some parts of the line had already been completed. Therefore, during studies, we gathered the data on the backfilled way on the three parallel profiles spaced 1m apart or on the service way next to the railway line. There was a tunnel on the line. We also gathered two parallel profiles data on the tunnel and four profiles data next to the tunnel to evaluate the stability according to the discontinuities. The petrographical studies and GPR results indicated that the areas with Jurassic alloctonous limestones thrusted on the ophiolitic rocks had deep and large fractures and cavities. The resulted radargrams indicated the thrust fault locations under the rail line. This limestone did not have a root and did not have big thickness. Therefore, the limestone could be move on the ophiolitic serpentinite unit. There were approximately horizontal and thin fracture segments under some parts of the tunnel nearly 8m in depth. There was an important collapsed zone filled up before. At the same time, there were thin and short fractures in the Jurassic limestone under the tunnel which was seen clearly on the radargrams. However, it was appeared that the hazard could not me removed completely because of the horizontal fracture. The areas with lacustrine limestones included disordered small fractures. Finally some areas had terra rossa because of the results of a large karstification. These areas could cause soil liquefaction during rainy season. The stability of these areas has to be controlled with ordered small periods.

Kadioglu, S.; Kadioglu, Y. K.

2012-04-01

312

MODFLOW-2000, the U.S. Geological Survey modular ground-water model : user guide to the LMT6 package, the linkage with MT3DMS for multi-species mass transport modeling  

USGS Publications Warehouse

MODFLOW-2000, the newest version of MODFLOW, is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium using a finite-difference method. MT3DMS, the successor to MT3D, is a computer program for modeling multi-species solute transport in three-dimensional ground-water systems using multiple solution techniques, including the finite-difference method, the method of characteristics (MOC), and the total-variation-diminishing (TVD) method. This report documents a new version of the Link-MT3DMS Package, which enables MODFLOW-2000 to produce the information needed by MT3DMS, and also discusses new visualization software for MT3DMS. Unlike the Link-MT3D Packages that coordinated previous versions of MODFLOW and MT3D, the new Link-MT3DMS Package requires an input file that, among other things, provides enhanced support for additional MODFLOW sink/source packages and allows list-directed (free) format for the flow model produced flow-transport link file. The report contains four parts: (a) documentation of the Link-MT3DMS Package Version 6 for MODFLOW-2000; (b) discussion of several issues related to simulation setup and input data preparation for running MT3DMS with MODFLOW-2000; (c) description of two test example problems, with comparison to results obtained using another MODFLOW-based transport program; and (d) overview of post-simulation visualization and animation using the U.S. Geological Survey?s Model Viewer.

Zheng, Chunmiao; Hill, Mary Catherine; Hsieh, Paul A.

2001-01-01

313

A method for sensor processing, sensor integration, and navigation in mobile autonomous ground vehicles  

NASA Astrophysics Data System (ADS)

This paper presents an algorithm for solving three challenges of autonomous navigation: sensor signal processing, sensor integration, and path-finding. The algorithm organizes these challenges into three steps. The first step involves converting the raw data from each sensor to a form suitable for real-time processing. Emphasis in the first step is on image processing. In the second step, the processed data from all sensors is integrated into a single map. Using this map as input, during the third step the algorithm calculates a goal and finds a suitable path from robot to the goal. The method presented in this paper completes these steps in this order and the steps repeat indefinitely. The robotic platform designed for testing the algorithm is a six-wheel mid-wheel drive system using differential steering. The robot, called Anassa II, has an electric wheelchair base and a custom-built top and it is designed to participate in the Intelligent Ground Vehicle Competition (IGVC). The sensors consist of a laser scanner, a video camera, a Differential Global Positioning System (DGPS) receiver, a digital compass, and two wheel encoders. Since many intelligent vehicles have similar sensors, the approach presented here is general enough for many types of autonomous mobile robots.

Riggins, Robert N.; Mutter, Bruce V.; Baker, Scott; Farmer, Jesse; Huntley, Joy; Kessler, Joe; Lewis, Lenny

2006-10-01

314

Surveys  

Cancer.gov

Behavioral Risk Factor Surveillance System (BRFSS) The world's largest, on-going telephone health survey system, tracking health conditions and risk behaviors in the United States yearly since 1984. Currently, data are collected monthly in all 50 states, the District of Columbia, Puerto Rico, the U.S. Virgin Islands, and Guam.

315

A survey of the broadband shock associated noise prediction methods  

NASA Technical Reports Server (NTRS)

Several different prediction methods to estimate the broadband shock associated noise of a supersonic jet are introduced and compared with experimental data at various test conditions. The nozzle geometries considered for comparison include a convergent and a convergent-divergent nozzle, both axisymmetric. Capabilities and limitations of prediction methods in incorporating the two nozzle geometries, flight effect, and temperature effect are discussed. Predicted noise field shows the best agreement for a convergent nozzle geometry under static conditions. Predicted results for nozzles in flight show larger discrepancies from data and more dependable flight data are required for further comparison. Qualitative effects of jet temperature, as observed in experiment, are reproduced in predicted results.

Kim, Chan M.; Krejsa, Eugene A.; Khavaran, Abbas

1992-01-01

316

Ground Albedo Neutron Sensing (GANS) method for measurements of soil moisture in cropped fields  

NASA Astrophysics Data System (ADS)

Measurement of soil moisture at the plot or hill-slope scale is an important link between local vadose zone hydrology and catchment hydrology. However, so far only few methods are on the way to close this gap between point measurements and remote sensing. This study evaluates the applicability of the Ground Albedo Neutron Sensing (GANS) for integral quantification of seasonal soil moisture in the root zone at the scale of a field or small watershed, making use of the crucial role of hydrogen as neutron moderator relative to other landscape materials. GANS measurements were performed at two locations in Germany under different vegetative situations and seasonal conditions. Ground albedo neutrons were measured at (i) a lowland Bornim farmland (Brandenburg) cropped with sunflower in 2011 and winter rye in 2012, and (ii) a mountainous farmland catchment (Schaefertal, Harz Mountains) since middle 2011. At both sites depth profiles of soil moisture were measured at several locations in parallel by frequency domain reflectometry (FDR) for comparison and calibration. Initially, calibration parameters derived from a previous study with corn cover were tested under sunflower and winter rye periods at the same farmland. GANS soil moisture based on these parameters showed a large discrepancy compared to classical soil moisture measurements. Therefore, two new calibration approaches and four different ways of integration the soil moisture profile to an integral value for GANS were evaluated in this study. This included different sets of calibration parameters based on different growing periods of sunflower. New calibration parameters showed a good agreement with FDR network during sunflower period (RMSE = 0.023 m3 m-3), but they underestimated soil moisture in the winter rye period. The GANS approach resulted to be highly affected by temporal changes of biomass and crop types which suggest the need of neutron corrections for long-term observations with crop rotation. Finally, Bornim sunflower parameters were transferred to Schaefertal catchment for further evaluation. This study proves GANS potential to close the measurement gap between point scale and remote sensing scale; however, its calibration needs to be adapted for vegetation in cropped fields.

Andres Rivera Villarreyes, Carlos; Baroni, Gabriele; Oswald, Sascha E.

2013-04-01

317

Simulations of Strong Ground Motion in the Los Angeles Basin Using the Spectral-Element Method  

NASA Astrophysics Data System (ADS)

We use the spectral-element method (SEM) to simulate strong ground motion in the Los Angeles basin. Our basin velocity model was constructed using sonic log and stacking velocity information provided by oil industry sources. The method includes effects due to attenuation, topography and bathymetry. The basin model is embedded into the regional model of Hauksson (2000). Our mesh honors the bottom part of the 8.5 km deep sedimentary pocket underneath downtown Los Angeles, as well as topography and bathymetry, and the Moho map of Zhu and Kanamori (2000). We double the mesh twice in the vertical direction based upon a conforming doubling `brick'. This allows us to increase the resolution of the SEM calculations near the surface, in low-velocity sediments. We obtain a high-quality mesh based upon a heuristic rule to prevent elements in the doubling regions from becoming too flat. The SEM is implemented on a parallel computer based upon a message-passing algorithm (MPI), and run on a large PC cluster, a so-called Beowulf machine. This allows us to model wave propagation in a large region that includes most of the TriNet stations. Results are shown for two small events (M = 4.2) that can be treated as point sources, the September 2001 Hollywood earthquake, and the September 2002 Yorba Linda event. We use a three-dimensional centroid-moment tensor inversion based upon the SEM and the basin model to determine the mechanisms and locations of these events. Excellent agreement is obtained for the three components of the data down to a period of 2 seconds.

Komatitsch, D.; Liu, Q.; Tromp, J.; Suess, P.; Shaw, J.

2003-04-01

318

A ground control points sampling design method based on smallest singular value  

NASA Astrophysics Data System (ADS)

The Ground Control Points (GCPs) are widely used in geometric correction for remote sensing imagery, and the distribution of them is a key factor which affects the accuracy and quality of image correction. In this paper, we propose a new sampling design method, called Smallest Singular Value-based Sampling (SSVS), to obtain the optimal distribution of the GCPs. When the geometric correction of remote sensing imagery is performed with a 2D or 3D polynomial function model, the estimation of geometric correction model parameters can be interpreted as an estimation of regression coefficients with a Multiple Linear Regression(MLR) model, whose design matrix depends on the coordinates of GCPs. From the perspective of regression model, the design matrix of MLR should be optimized to obtain the most accurate regression coefficients. In this paper, it has been proved that the Smallest Singular Value(SSV) of design matrix is inversely proportional to the upper bound of estimation errors. By choosing the optimal distribution of GCPs, the SSV of design matrix can be maximized and the upper bound of estimation errors can be minimized. Therefore, the SSV of design matrix is used as a criterion, and the objective of SSVS is to find the sample pattern that has the biggest SSV. In this paper, the simulation annealing is employed to search the optimal pattern. Two experiments were carried out to test SSVS. The results indicate that the SSVS is an effective GCPs sampling design method and can be applied to evaluate upper bound of estimation error.

Wang, Pu; An, Wei; Deng, Xing Pu; Guo, Jing; Li, Jun

2014-10-01

319

A survey of forensic characterization methods for physical devices  

Microsoft Academic Search

This paper describes methods for forensic characterization of physical devices. This is important in verifying the trust and authenticity of data and the device that created it. Current forensic identification techniques for digital cameras, printers, and RF devices are presented. It is also shown how these techniques can fit into a general forensic characterization framework, which can be generalized for

Nitin Khanna; Aravind K. Mikkilineni; Anthony F. Martone; Gazi N. Ali; George T.-C. Chiu; Jan P. Allebach; Edward J. Delp

2006-01-01

320

Computational methods for Traditional Chinese Medicine: A survey  

Microsoft Academic Search

Traditional Chinese Medicine (TCM) has been actively researched through various approaches, including computational techniques. A review on basic elements of TCM is provided to illuminate various challenges and progresses in its study using computational methods. Information on various TCM formulations, in particular resources on databases of TCM formulations and their integration to Western medicine, are analyzed in several facets, such

Suryani Lukman; Yulan He; Siu-Cheung Hui

2007-01-01

321

DISCONTINUOUS GALERKIN METHOD FOR TIME DEPENDENT PROBLEMS: SURVEY AND RECENT  

E-print Network

fluxes and total variation bounded (TVB) nonlinear limiters [79] to achieve non-oscillatory properties-of-lines, namely the DG discretization is used only for the spatial variables, and explicit, nonlin- early stable. The DG method has found rapid applications in such diverse areas as aeroacoustics, electro-magnetism, gas

Shu, Chi-Wang

322

NCES Handbook of Survey Methods. NCES 2011-609  

ERIC Educational Resources Information Center

Since its inception, the National Center for Education Statistics (NCES) has been committed to the practice of documenting its statistical methods for its customers and of seeking to avoid misinterpretation of its published data. The reason for this policy is to assure customers that proper statistical standards and techniques have been observed,…

Burns, Shelley, Ed.; Wang, Xiaolei, Ed.; Henning, Alexandra, Ed.

2011-01-01

323

Inverse Combinatorial Optimization: A Survey on Problems, Methods, and Results  

Microsoft Academic Search

Given a (combinatorial) optimization problem and a feasible solution to it, the correspond- ing inverse optimization problem is to nd a minimal adjustment of the cost function such that the given solution becomes optimum. Several such problems have been studied in the last ten years. After formalizing the notion of an inverse problem and its variants, we present various methods

Clemens Heuberger

2004-01-01

324

A Survey of Current Methods in Medical Image Segmentation  

Microsoft Academic Search

Image segmentation plays a crucial role in many medical imaging applications by automat- ing or facilitating the delineation of anatomical structures and other regions of interest. We present herein a critical appraisal of the current status of semi-automated and automated methods for the segmentation of anatomical medical images. Current segmentation approaches are reviewed with an emphasis placed on revealing the

Dzung L. Pham; Jerry L. Prince

1999-01-01

325

A survey of numerical methods for shock physics applications  

SciTech Connect

Hydrocodes or more accurately, shock physics analysis packages, have been widely used in the US Department of Energy (DOE) laboratories and elsewhere around the world for over 30 years. Initial applications included weapons effects studies where the pressure levels were high enough to disregard the material strength, hence the term hydrocode. Over the last 30 years, Sandia has worked extensively to develop and apply advanced hydrocodes to armor/anti-armor interactions, warhead design, high explosive initiation, and nuclear weapon safety issues. The needs of the DOE have changed over the last 30 years, especially over the last decade. A much stronger emphasis is currently placed on the details of material deformation and high explosive initiation phenomena. The hydrocodes of 30 years ago have now evolved into sophisticated analysis tools that can replace testing in some situations and complement it in all situations. A brief history of the development of hydrocodes in the US will be given. The author also discusses and compares the four principal methods in use today for the solution of the conservation equations of mass, momentum, and energy for shock physics applications. The techniques discussed are the Eulerian methods currently employed by the Sandia multi-dimensional shock physics analysis package known as CTH; the element based Lagrangian method currently used by codes like DYNA; the element free Lagrangian method (also known as smooth particle hydrodynamics) used by codes like the Los Alamos code SPHINX; and the Arbitrary Lagrangian Eulerian methods used by codes like the Lawrence Livermore code CALE or the Sandia code ALEGRA.

Hertel, E.S. Jr.

1997-10-01

326

Suitability of the Respirometric Bod Oxitop Method for Determining the Biodegradability of Oils in Ground Water using Forestry Hydraulic Oils as Model Compounds  

Microsoft Academic Search

Different forestry hydraulic oils were used as model compounds for evaluating the applicability of the respirometric BOD Oxitop method in following the progress of biodegradation of oils in ground water. It is obvious that the biodegradability values of substances depend on the measurement medium used. In this study the same ground water was used in all the ground water experiments.

Toivo Kuokkanen; Pekka Vähäoja; Ilkka Välimäki; Risto Lauhanen

2004-01-01

327

Measuring galaxy [O ii] emission line doublet with future ground-based wide-field spectroscopic surveys  

NASA Astrophysics Data System (ADS)

The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7 ? z ? 2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [Oii] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [Oii] (?? 3727, 3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies for the choice of the resolution for future spectrographs for BAO surveys. For bright [Oii] emitter surveys ([Oii] flux ~30 × 10-17 erg cm-2 s-1 like SDSS-IV/eBOSS), a resolution of R ~ 3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [Oii] emitter surveys ([Oii] flux ~10 × 10-17 erg cm-2 s-1 like DESi), the detection improves continuously with resolution, so we recommend the highest possible resolution, the limit being given by the number of pixels (4k by 4k) on the detector and the number of spectroscopic channels (2 or 3).

Comparat, Johan; Kneib, Jean-Paul; Bacon, Roland; Mostek, Nick J.; Newman, Jeffrey A.; Schlegel, David J.; Yèche, Christophe

2013-11-01

328

Computer Program for Thin Wire Antenna over a Perfectly Conducting Ground Plane. [using Galerkins method and sinusoidal bases  

NASA Technical Reports Server (NTRS)

A computer program is presented for a thin-wire antenna over a perfect ground plane. The analysis is performed in the frequency domain, and the exterior medium is free space. The antenna may have finite conductivity and lumped loads. The output data includes the current distribution, impedance, radiation efficiency, and gain. The program uses sinusoidal bases and Galerkin's method.

Richmond, J. H.

1974-01-01

329

A method to suppress dielectric breakdowns in liquid argon ionization detectors for cathode to ground distances of several millimeters  

E-print Network

We present a method to reach electric field intensity as high as 400 kV/cm in liquid argon for cathode-ground distances of several millimeters. This can be achieved by suppressing field emission from the cathode, overcoming limitations that we reported earlier.

M. Auger; A. Ereditato; D. Goeldi; S. Janos; I. Kreslo; M. Luethi; C. Rudolf von Rohr; T. Strauss; T. Tolba; M. S. Weber

2014-06-16

330

Quality assessment of restored soils: combination of classical soil science methods with ground penetrating radar and near infrared aerial photography?  

Microsoft Academic Search

In Switzerland agricultural land is usually restored after gravel exploitation. In order to minimize soil damage, the quality of restored soils should be checked by the authorities. To assess the physical soil properties, a combination of classical soil science methods with ground-penetrating radar (GPR) and near infrared (IR) aerial photography was tested in 1994–1995. GPR profiles were recorded in the

B. Friedli; S. Tobias; M. Fritsch

1998-01-01

331

A COMPARISON OF SAMPLE PREPARATION METHODS FOR PCR-BASED DETECTION OF PATHOGENIC YERSINIA ENTEROCOLITICA IN GROUND PORK  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sample preparation methods for multiplex PCR for detection of plasmid-bearing virulent Yersinia enterocolitica (YEP+) from ground pork (GP) were compared. The GP samples were first inoculated with 10, 1 and 0.5 CFU/cm2 of YEP+, one set was swabbed and the second set was dispersed into a slurry usin...

332

A Survey of Synchronization Methods for Parallel Computers  

Microsoft Academic Search

An examination is given of how traditional synchronization methods influence the design of MIMD (multiple-instruction multiple-data-stream) multiprocessors. She provides an overview of MIMD multiprocessing and goes on to discuss semaphore-based implementations (Ultracomputers, Cedar, and the Sequent Balance\\/21000), monitor-based implementations (the HM\\/sup 2\\/p) and implementations based on message-passing (HEP, the BBN Butterfly and the Transputer).

Anne Dinning

1989-01-01

333

Method for Studying a Human Ecology: An Adaptation of the Grounded Theory Tradition  

SciTech Connect

Constructivist grounded theory is focused on discovery through understanding data in a human ecology. The procedures outlined in this paper are designed to guide the beginning theorist through the process of creating a theory grounded in data that is a product of the human ecology under study. These new procedures extend grounded theory, providing bridges in moving from study phenomenon to design and from analysis to interpretation. Procedures for analyzing the data must be clearly understood before beginning grounded theory methodology. Strategies must be outlined, approaches to the ecology discussed, and awareness of the ecology attained. Following these procedures can lead to a rewarding qualitative research experience and produce new knowledge for understanding the human ecology.

McCaslin, Mark L.; Scott, Karen Wilson; Carlson, Nancy Margaret

2002-01-01

334

Methods and Strategies: The Common Ground -- A rationale for integrating science and reading  

NSDL National Science Digital Library

Building on the common ground between subjects through integration helps teachers address learning goals in both subjects without compromising either. This article addresses ways to integrate science with language arts objectives.

Christine Anne Royce

2005-02-01

335

A survey method for estimating potential levels of mangrove forest primary production  

Microsoft Academic Search

Measurements of net photosynthesis in mangrove communities by direct methods is technically and logistically difficult. Recording litter fall alone neglects other important components of production. A method has been developed which lends itself to ready application for obtaining survey estimates of photosynthetic yield. The procedure involves measurement of light attenuation through forest canopies attributable to photosynthetic utilization and standardized against

J. S. Bunt; K. G. Boto; G. Boto

1979-01-01

336

A Survey of Methods of Deriving Individual Grades from Group Assessments  

Microsoft Academic Search

This paper surveys the different methods of assessing groups of students which have been reported in the literature and describes some novel methods which have been used at the University of Sunderland. It relates the work of Schechtman to peer assessment in a group setting, discusses some observations on self?assessment and raises some questions for debate and future research.

Mark Lejk; Michael Wyvill; Stephen Farrow

1996-01-01

337

Note--A Computational Survey of Methods for the Set Covering Problem  

Microsoft Academic Search

This paper is a survey of available methods for the solution of the Set Covering Problem. The prime objective has been to establish the computational efficiency and relative merits of the various algorithms that have been proposed. To this end five methods have been programmed and tested on the same set of 33 test problems some of which can be

Nicos Christofides; S. Korman

1975-01-01

338

Teaching and learning computer programming: a survey of student problems, teaching methods, and automated instructional tools  

Microsoft Academic Search

To improve introductory computer science courses and to update the teaching of computer programming, new teaching methods emphasizing structured programming and top-down design have been presented and a variety of automated instructional tools have been developed. The purpose of this paper is: (1) to survey a number of methods and tools used in the teaching of programming; (2) to present,

Miguel Ulloa

1980-01-01

339

Evaluation of Two Survey Methods for Detection of Helminth Infections in \\\\White? tailed Deer (Odocoileus virginianus)  

Microsoft Academic Search

White-tailed deer, Odocoileus virginianus, from central Pennsyl- vania were examined for helminth parasites by regular autopsy pro- cedures supplemented by a direct centrifugal flotation technique. The two methods were compared and evaluated for suitability in diagnosis and survey work. The reliability and repeatability of the flotation method were studied. Prevalence of most nematodes encountered was increased as a direct result

W. M. SAMUEL; R. L. BEAUDOIN

1966-01-01

340

"Same, Same but Different" A Survey on Duplicate Detection Methods for  

E-print Network

"Same, Same but Different" A Survey on Duplicate Detection Methods for Situation Awareness Norbert Abstract. Systems supporting situation awareness typically deal with a vast stream of information about examines existing duplicate detection methods ap- pearing to be suitable in the area of situation awareness

Hochreiter, Sepp

341

Airborne lidar surveys are an at-tractive alternative to the methods  

E-print Network

264 Airborne lidar surveys are an at- tractive alternative to the methods presentlyusedinfishery aerial methods. A lidar, (li[ght] d[etecting] and r[anging]) system, in its most basic form, pro- duces the range (depth below the sur- face) of the target. The application of lidar technology to fishery sur

342

How should social mixing be measured: comparing web-based survey and sensor-based methods  

PubMed Central

Background Contact surveys and diaries have conventionally been used to measure contact networks in different settings for elucidating infectious disease transmission dynamics of respiratory infections. More recently, technological advances have permitted the use of wireless sensor devices, which can be worn by individuals interacting in a particular social context to record high resolution mixing patterns. To date, a direct comparison of these two different methods for collecting contact data has not been performed. Methods We studied the contact network at a United States high school in the spring of 2012. All school members (i.e., students, teachers, and other staff) were invited to wear wireless sensor devices for a single school day, and asked to remember and report the name and duration of all of their close proximity conversational contacts for that day in an online contact survey. We compared the two methods in terms of the resulting network densities, nodal degrees, and degree distributions. We also assessed the correspondence between the methods at the dyadic and individual levels. Results We found limited congruence in recorded contact data between the online contact survey and wireless sensors. In particular, there was only negligible correlation between the two methods for nodal degree, and the degree distribution differed substantially between both methods. We found that survey underreporting was a significant source of the difference between the two methods, and that this difference could be improved by excluding individuals who reported only a few contact partners. Additionally, survey reporting was more accurate for contacts of longer duration, and very inaccurate for contacts of shorter duration. Finally, female participants tended to report more accurately than male participants. Conclusions Online contact surveys and wireless sensor devices collected incongruent network data from an identical setting. This finding suggests that these two methods cannot be used interchangeably for informing models of infectious disease dynamics. PMID:24612900

2014-01-01

343

Indigo snake capture methods: effectiveness of two survey techniques for Drymarchon couperi in Georgia  

USGS Publications Warehouse

Drymarchon couperi (Eastern Indigo Snake), a federally threatened species of the southeastern Coastal Plain, has presented challenges for surveyors, with few reliable methods developed for its detection or monitoring. Surveys for D. couperi at potential underground shelters conducted in late fall through early spring have been relatively successful when conducted by experienced surveyors, especially in the northern portions of the range. However, trapping efforts for D. couperi conducted throughout the range have met with limited success. To further evaluate detection methods, we conducted trapping and surveying from December 2002 to April 2004 in areas known to support D. couperi in southeastern Georgia. We captured 18 D. couperi through surveys of potential underground shelters from December 2002 to March 2003 (14 person-hours per capture) and six individuals through trapping (141 trap days or 27 in-field person-hours per capture). Trapping was most successful during early fall, a period when surveys are often less effective compared to those conducted in late fall through early spring. We recommend a combination of surveys from mid-fall through March in conjunction with trapping, especially from late-summer through fall in the northern portions of the snake?s range. We also recommend further experimentation with alternative trap designs and survey methods for D. couperi.

Hyslop, N.L.; Meyers, J.M.; Cooper, R.J.; Stevenson, J.

2009-01-01

344

Calculation of broadband time histories of ground motion: Comparison of methods and validation using strong-ground motion from the 1994 Northridge earthquake  

USGS Publications Warehouse

This article compares techniques for calculating broadband time histories of ground motion in the near field of a finite fault by comparing synthetics with the strong-motion data set for the 1994 Northridge earthquake. Based on this comparison, a preferred methodology is presented. Ground-motion-simulation techniques are divided into two general methods: kinematic- and composite-fault models. Green's functions of three types are evaluated: stochastic, empirical, and theoretical. A hybrid scheme is found to give the best fit to the Northridge data. Low frequencies ( 1 Hz) are calculated using a composite-fault model with a fractal subevent size distribution and stochastic, bandlimited, white-noise Green's functions. At frequencies below 1 Hz, theoretical elastic-wave-propagation synthetics introduce proper seismic-phase arrivals of body waves and surface waves. The 3D velocity structure more accurately reproduces record durations for the deep sedimentary basin structures found in the Los Angeles region. At frequencies above 1 Hz, scattering effects become important and wave propagation is more accurately represented by stochastic Green's functions. A fractal subevent size distribution for the composite fault model ensures an ??-2 spectral shape over the entire frequency band considered (0.1-20 Hz).

Hartzell, S.; Harmsen, S.; Frankel, A.; Larsen, S.

1999-01-01

345

Development of optical ground verification method for ?m to sub-mm reflectors  

NASA Astrophysics Data System (ADS)

Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. Scientific observatories require large telescopes with precisely shaped reflectors for collecting the electro-magnetic radiation from faint sources. The challenging tasks of on-ground testing are to achieve the required accuracy in the measurement of the reflector shapes and antenna structures and to verify their performance under simulated space conditions (vacuum, low temperatures). Due to the specific surface characteristics of reflectors operating in these spectral regions, standard optical metrology methods employed in the visible spectrum do not provide useful measurement results. The current state-of-the-art commercial metrology systems are not able to measure these types of reflectors because they have to face the measurement of shape and waviness over relatively large areas with a large deformation dynamic range and encompassing a wide range of spatial frequencies. 3-D metrology (tactile coordinate measurement) machines are generally used during the manufacturing process. Unfortunately, these instruments cannot be used in the operational environmental conditions of the reflector. The application of standard visible wavelength interferometric methods is very limited or impossible due to the large relative surface roughnesses involved. A small number of infrared interferometers have been commercially developed over the last 10 years but their applications have also been limited due to poor dynamic range and the restricted spatial resolution of their detectors. These restrictions affect also the surface error slopes that can be captured and makes their application to surfaces manufactured using CRFP honeycomb technologies rather difficult or impossible. It has therefore been considered essential, from the viewpoint of supporting future ESA exploration missions, to develop and realise suitable verification tools based on infrared interferometry and other optical techniques for testing large reflector structures, telescope configurations and their performances under simulated space conditions. The first one is an IR-phase shifting interferometer with high spatial resolution. This interferometer shall be used specifically for the verification of high precision IR, FIR and sub-mm reflector surfaces and telescopes under both ambient and thermal vacuum conditions. The second one presented hereafter is a holographic method for relative shape measurement. The holographic solution proposed makes use of a home built vacuum compatible holographic camera that allows displacement measurements from typically 20 nanometres to 25 microns in one shot. An iterative process allows the measurement of a total of up to several mm of deformation. Uniquely the system is designed to measure both specular and diffuse surfaces.

Stockman, Y.; Thizy, C.; Lemaire, P.; Georges, M.; Mazy, E.; Mazzoli, A.; Houbrechts, Y.; Rochus, P.; Roose, S.; Doyle, D.; Ulbrich, G.

2004-06-01

346

Method for validating cloud mask obtained from satellite measurements using ground-based sky camera.  

PubMed

Error propagation in Earth's atmospheric, oceanic, and land surface parameters of the satellite products caused by misclassification of the cloud mask is a critical issue for improving the accuracy of satellite products. Thus, characterizing the accuracy of the cloud mask is important for investigating the influence of the cloud mask on satellite products. In this study, we proposed a method for validating multiwavelength satellite data derived cloud masks using ground-based sky camera (GSC) data. First, a cloud cover algorithm for GSC data has been developed using sky index and bright index. Then, Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data derived cloud masks by two cloud-screening algorithms (i.e., MOD35 and CLAUDIA) were validated using the GSC cloud mask. The results indicate that MOD35 is likely to classify ambiguous pixels as "cloudy," whereas CLAUDIA is likely to classify them as "clear." Furthermore, the influence of error propagations caused by misclassification of the MOD35 and CLAUDIA cloud masks on MODIS derived reflectance, brightness temperature, and normalized difference vegetation index (NDVI) in clear and cloudy pixels was investigated using sky camera data. It shows that the influence of the error propagation by the MOD35 cloud mask on the MODIS derived monthly mean reflectance, brightness temperature, and NDVI for clear pixels is significantly smaller than for the CLAUDIA cloud mask; the influence of the error propagation by the CLAUDIA cloud mask on MODIS derived monthly mean cloud products for cloudy pixels is significantly smaller than that by the MOD35 cloud mask. PMID:25402920

Letu, Husi; Nagao, Takashi M; Nakajima, Takashi Y; Matsumae, Yoshiaki

2014-11-01

347

MODFLOW-2005, the U.S. Geological Survey modular ground-water model - documentation of shared node local grid refinement (LGR) and the boundary flow and head (BFH) package  

USGS Publications Warehouse

This report documents the addition of shared node Local Grid Refinement (LGR) to MODFLOW-2005, the U.S. Geological Survey modular, transient, three-dimensional, finite-difference ground-water flow model. LGR provides the capability to simulate ground-water flow using one block-shaped higher-resolution local grid (a child model) within a coarser-grid parent model. LGR accomplishes this by iteratively coupling two separate MODFLOW-2005 models such that heads and fluxes are balanced across the shared interfacing boundary. LGR can be used in two-and three-dimensional, steady-state and transient simulations and for simulations of confined and unconfined ground-water systems. Traditional one-way coupled telescopic mesh refinement (TMR) methods can have large, often undetected, inconsistencies in heads and fluxes across the interface between two model grids. The iteratively coupled shared-node method of LGR provides a more rigorous coupling in which the solution accuracy is controlled by convergence criteria defined by the user. In realistic problems, this can result in substantially more accurate solutions and require an increase in computer processing time. The rigorous coupling enables sensitivity analysis, parameter estimation, and uncertainty analysis that reflects conditions in both model grids. This report describes the method used by LGR, evaluates LGR accuracy and performance for two- and three-dimensional test cases, provides input instructions, and lists selected input and output files for an example problem. It also presents the Boundary Flow and Head (BFH) Package, which allows the child and parent models to be simulated independently using the boundary conditions obtained through the iterative process of LGR.

Mehl, Steffen W.; Hill, Mary C.

2006-01-01

348

An UAV scheduling and planning method for post-disaster survey  

NASA Astrophysics Data System (ADS)

Annually, the extreme climate and special geological environments lead to frequent natural disasters, e.g., earthquakes, floods, etc. The disasters often bring serious casualties and enormous economic losses. Post-disaster surveying is very important for disaster relief and assessment. As the Unmanned Aerial Vehicle (UAV) remote sensing with the advantage of high efficiency, high precision, high flexibility, and low cost, it is widely used in emergency surveying in recent years. As the UAVs used in emergency surveying cannot stop and wait for the happening of the disaster, when the disaster happens the UAVs usually are working at everywhere. In order to improve the emergency surveying efficiency, it is needed to track the UAVs and assign the emergency surveying task for each selected UAV. Therefore, a UAV tracking and scheduling method for post-disaster survey is presented in this paper. In this method, Global Positioning System (GPS), and GSM network are used to track the UAVs; an emergency tracking UAV information database is built in advance by registration, the database at least includes the following information, e.g., the ID of the UAVs, the communication number of the UAVs; when catastrophe happens, the real time location of all UAVs in the database will be gotten using emergency tracking method at first, then the traffic cost time for all UAVs to the disaster region will be calculated based on the UAVs' the real time location and the road network using the nearest services analysis algorithm; the disaster region is subdivided to several emergency surveying regions based on DEM, area, and the population distribution map; the emergency surveying regions are assigned to the appropriated UAV according to shortest cost time rule. The UAVs tracking and scheduling prototype is implemented using SQLServer2008, ArcEnginge 10.1 SDK, Visual Studio 2010 C#, Android, SMS Modem, and Google Maps API.

Li, G. Q.; Zhou, X. G.; Yin, J.; Xiao, Q. Y.

2014-11-01

349

A HELICOPTER-BASED SURVEY METHOD FOR MONITORING THE NESTING COMPONENT OF SNOW GOOSE COLONIES  

Microsoft Academic Search

A new strip transect method to monitor numbers of nesting snow geese (Chen caerulescens) employs a helicopter to fly three observers at a low level (100 feet above ground level (AGL)) along fixed transects over the colony. Observers count all snow goose nests within the transect belt which is 100 m wide. The aircraft's Global Positioning System (GPS) is used

R. KENYON ROSS; KENNETH F. ABRAHAM; DONALD FILLMAN; BRIAN T. COLLINS; RICHARD H. KERBES

350

A hybrid visual estimation method for the collection of ground truth fractional coverage data in a humid tropical environment  

NASA Astrophysics Data System (ADS)

A substantial body of research exists exploring the spectral unmixing of remotely sensed image data. Specifically, we refer to the attempts and successes to model the percent vegetation cover (2-dimensional horizontal density) within a pixel, known as fractional coverage (fc). With this paper, we present a hybrid visual estimation method for fc field data collection in the complex landscapes found in humid tropical environments. The method includes a scalable theoretical model of fc, integrates the visual estimation technique with hemispherical photography collection, and is conducted over a systematic ground collection area. We present results from a case study conducted in the humid tropical region of Ecuador. Specifically, we report on the relationship between fc data modeled using a linear NDVI transformation and observed fc data collected using our hybrid visual estimation method. Our study found a significant, positive linear relationship (? = 0.795, r2 > 0.84, and p < 0.001) between modeled and observed fc values. Because the accuracy of both modeled and observed values are unknown, a full validation of the proposed method of collection is not possible. Therefore, we conduct an error assessment, identifying limitations in the modeling method (e.g., non-linear relationship between modeled and true values and potential for saturation) and hybrid ground-truth collection method (e.g., subjectivity of visual estimation and positional errors in the ground collection area) that explain the deviation from a 1:1 relationship. We believe the proposed method of ground truth data collection is a significant contribution towards efforts to validate biophysical information gained from remotely sensed data.

Delamater, Paul L.; Messina, Joseph P.; Qi, Jiaguo; Cochrane, Mark A.

2012-08-01

351

Identifying reasons for delays in acute hospitals using the Day-of-Care Survey method.  

PubMed

This paper describes a new tool called 'Day-of-Care Survey', developed to assess inpatient delays in acute hospitals. Using literature review, iterative testing and feedback from professional groups, a national multidisciplinary team developed the survey criteria and methodology. Review teams working in pairs visited wards and used case records and bedside charts to assess the patient's status against severity of illness and service intensity criteria. Patients who did not meet the survey criteria for acute care were identified and delays were categorised. From March 2012 to December 2013, nine acute hospitals across Scotland, Australia and England were surveyed. A total of 3,846 adult general inpatient beds (excluding intensive care and maternity) were reviewed. There were 145 empty beds at the time of surveys across the nine sites, with 270 definite discharges planned on the day of the survey. The total number of patients not meeting criteria for acute care was 798/3,431 (23%, range 18-28%). Six factors accounted for 61% (490/798) of the reasons why patients not meeting acute care criteria remained in hospital. This survey gives important insights into the challenges of managing inpatient flow using system level information as a method to target interventions designed to address delay. PMID:25824060

Reid, Erica; King, Andrew; Mathieson, Alex; Woodcock, Thomas; Watkin, Simon W

2015-04-01

352

Cross-Cultural Issues of Intra- and Inter-Organisational Cooperation in Space Operations: A Survey Study with Ground Personnel of the European Space Agency  

Microsoft Academic Search

Today's space operations often involve close co-working of people with different ethnical, professional and organizational backgrounds. The aim of the study was to examine the implications of cultural diversity for efficient collaboration within the European Space Agency (ESA), and between ESA employees and representatives from other agencies. Methods: A web-based survey was answered by 905 employees at the European Astronaut

Gro Mjeldheim Sandal; Dietrich Manzey

2008-01-01

353

Methods and Sources of Data Used to Develop Selected Water-Quality Indicators for Streams and Ground Water for EPA's 2007 Report on the Environment: Science Report  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) was one of numerous governmental agencies, private organizations, and the academic community that provided data and interpretations for the U.S. Environmental Protection Agency?s (USEPA) 2007 Report on the Environment: Science Report. This report documents the sources of data and methods used to develop selected water?quality indicators for the 2007 edition of the report compiled by USEPA. Stream and ground?water?quality data collected nationally in a consistent manner as part of the USGS?s National Water?Quality Assessment Program (NAWQA) were provided for several water?quality indicators, including Nitrogen and Phosphorus in Streams in Agricultural Watersheds; Pesticides in Streams in Agricultural Watersheds; and Nitrate and Pesticides in Shallow Ground Water in Agricultural Watersheds. In addition, the USGS provided nitrate (nitrate plus nitrite) and phosphorus riverine load estimates calculated from water?quality and streamflow data collected as part of its National Stream Water Quality Accounting Network (NASQAN) and its Federal?State Cooperative Program for the Nitrogen and Phosphorus Discharge from Large Rivers indicator.

Baker, Nancy T.; Wilson, John T.; Moran, Michael J.

2008-01-01

354

Compilation of field methods used in geochemical prospecting by the U.S. Geological Survey  

USGS Publications Warehouse

The field methods described in this report are those currently used in geochemical prospecting by the U. S. Geological Survey. Some have been published, others are being processed for publication, while others are still being investigated. The purpose in compiling these methods is to make them readily available in convenient form. The methods have not been thoroughly tested and none is wholly satisfactory. Research is being continued.

Lakin, Hubert William; Ward, Frederick Norville; Almond, Hy

1952-01-01

355

Gamma/Hadron segregation using Random Forest method in ground based Gamma Ray Astronomy: Random Forest Leads  

NASA Astrophysics Data System (ADS)

The conventional methods of Gamma/Hadron segregation for ground based Atmospheric Cherenkov telescopes break down below 200 GeV. A machine learning method ``Random Forest'' is employed for gamma/hadron segregation. Random Forest (RF) is a flexible multivariate selection method which combines `Bagging' and `Random Split Selection' to construct a large collection of decision trees and then combines them to construct a common classifier. In this work, we have evaluated and compared various machine learning methods such as Support Vector Machine, Artificial Neural Network, Naive Bayes Classifiers, Standard Discriminant Analysis as well as the conventional dynamic supercut method with the Random Forest method. It is demonstrated that the Random Forest method is the most sensitive machine learning method for ?-hadron segregation in the low energy regime where the upcoming MACE (Major Atmospheric Cherenkov Experiment) telescope will be operational.

Sharma, Mradul; Nayak, J.; Koul, M. K.; Bose, S.; Bhatt, N. G.; Mitra, Abhas

356

Ground penetrating radar survey finalized to the recovery of the “S. Agata alla Badia” church in Catania (eastern Sicily, Italy)  

Microsoft Academic Search

Numerous archaeological sites dating to the greek-roman period have been found in the underground of the city of Catania (eastern\\u000a Sicily, Italy). Their presence is a testimony of the several settlements that have followed in this area over time. In this\\u000a work we have conducted electromagnetic surveys, consisting of ten georadar profiles, inside the church of “S. Agata alla Badia”,

S. Imposa; F. Barone; S. Gresta; A. Leone

2009-01-01

357

Inclusion of trial functions in the Langevin equation path integral ground state method: Application to parahydrogen clusters and their isotopologues  

NASA Astrophysics Data System (ADS)

We developed and studied the implementation of trial wavefunctions in the newly proposed Langevin equation Path Integral Ground State (LePIGS) method [S. Constable, M. Schmidt, C. Ing, T. Zeng, and P.-N. Roy, J. Phys. Chem. A 117, 7461 (2013)]. The LePIGS method is based on the Path Integral Ground State (PIGS) formalism combined with Path Integral Molecular Dynamics sampling using a Langevin equation based sampling of the canonical distribution. This LePIGS method originally incorporated a trivial trial wavefunction, ?T, equal to unity. The present paper assesses the effectiveness of three different trial wavefunctions on three isotopes of hydrogen for cluster sizes N = 4, 8, and 13. The trial wavefunctions of interest are the unity trial wavefunction used in the original LePIGS work, a Jastrow trial wavefunction that includes correlations due to hard-core repulsions, and a normal mode trial wavefunction that includes information on the equilibrium geometry. Based on this analysis, we opt for the Jastrow wavefunction to calculate energetic and structural properties for parahydrogen, orthodeuterium, and paratritium clusters of size N = 4 - 19, 33. Energetic and structural properties are obtained and compared to earlier work based on Monte Carlo PIGS simulations to study the accuracy of the proposed approach. The new results for paratritium clusters will serve as benchmark for future studies. This paper provides a detailed, yet general method for optimizing the necessary parameters required for the study of the ground state of a large variety of systems.

Schmidt, Matthew; Constable, Steve; Ing, Christopher; Roy, Pierre-Nicholas

2014-06-01

358

Detection of hotspots and rapid determination of methane emissions from landfills via a ground-surface method.  

PubMed

We present a method for the rapid determination of methane emissions from landfills based on atmospheric dispersion theory, which suggests that the methane concentration, at a small distance from the soil/atmosphere interface, is proportional to its flux. Thus, after suitable calibration, the determination of methane concentrations close to the ground allows for flux determination in a shorter time than with standard enclosure techniques. This concept was tested using a surface probe in direct contact with the ground. The probe extracts a continuous sample of the air at the probe/ground interface and transports it to a portable methane analyzer. It was observed that stable methane concentrations were measured 30 s after the probe was positioned at the measurement point. These concentrations correlated well with the fluxes measured by standard static chambers. The method was used to determine the fluxes at 217 points within a 90,000 m(2) landfill. These measurements facilitated mapping of the CH4 emissions and the localization of hotspots. We conclude that the method is simple, effective, and relatively quick, compared to existing standard methods. PMID:25399118

Gonzalez-Valencia, R; Magana-Rodriguez, F; Maldonado, E; Salinas, J; Thalasso, F

2015-01-01

359

A Simple Method for Measuring Ground-Level Ozone in the Atmosphere  

ERIC Educational Resources Information Center

An iodometric assay that allows the ground-level ozone concentration to be determined with an inexpensive sampling apparatus and a homemade photometer is described. This laboratory experiment applies a variety of different fundamental concepts including oxidation-reduction chemistry, the ideal gas law, and spectroscopic analysis and also provides…

Seeley, John V.; Seeley, Stacy K.; Bull, Arthur W.; Fehir, Richard J., Jr.; Cornwall, Susan; Knudsen, Gabriel A.

2005-01-01

360

Development of optical ground verification method for mum to sub-mm reflectors  

Microsoft Academic Search

Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. Scientific observatories require large telescopes with precisely shaped reflectors for collecting the electro-magnetic radiation from faint sources. The challenging tasks of on-ground testing are to achieve the required accuracy in the

Y. Stockman; C. Thizy; P. Lemaire; M. Georges; E. Mazy; A. Mazzoli; Y. Houbrechts; P. Rochus; S. Roose; D. Doyle; G. Ulbrich

2004-01-01

361

Methods of Gas Phase Capture of Iodine from Fuel Reprocessing Off-Gas: A Literature Survey  

SciTech Connect

A literature survey was conducted to collect information and summarize the methods available to capture iodine from fuel reprocessing off-gases. Techniques were categorized as either wet scrubbing or solid adsorbent methods, and each method was generally described as it might be used under reprocessing conditions. Decontamination factors are quoted only to give a rough indication of the effectiveness of the method. No attempt is made to identify a preferred capture method at this time, although activities are proposed that would provide a consistent baseline that would aid in evaluating technologies.

Daryl Haefner

2007-02-01

362

A Field Test of Electromigration as a Method for Remediating Sulfate from Shallow Ground Water  

USGS Publications Warehouse

Electromigration offers a potential tool for remediating ground water contaminated with highly soluble components, such as Na+, Cl-, NO3-, and SO4-. A field experiment was designed to test the efficacy of electromigration for preconcentrating dissolved SO42- in ground water associated with a fossil-fuel power plant. Two shallow wells, 25 feet apart (one 25 feet deep, the other 47 feet deep), were constructed in the upper portion of an unconfined alluvial aquifer. The wells were constructed with a double-wall design, with an outer casing of 4-inch PVC and an inner tube of 2-inch PVC; both were fully slotted (0.01 inch). Electrodes were constructed by wrapping the inner tubing with a 100-foot length of rare-earth metal oxide/copper wire. An electrical potential of 10.65 volts DC was applied, and tests were run for periods of 12, 44, and 216 hours. Results showed large changes in the pH from the initial pH of ground water of about 7.5 to values of approximately 2 and 12 at the anode and cathode, respectively. Despite the fact that the test conditions were far from ideal, dissolved SO42- was significantly concentrated at the anode. Over a period of approximately nine days, the concentration of SO42- at the anode reached what appeared to be a steady-state value of 2200 mg/L, compared to the initial value in ground water of approximately 1150 mg/L. The results of this field test should encourage further investigation of electromigration as a tool in the remediation of contaminated ground water.

Patterson, C.G.; Runnells, D.D.

1996-01-01

363

A data input program (MFI2K) for the U.S. Geological Survey modular ground-water model (MODFLOW-2000)  

USGS Publications Warehouse

MFI2K is a data-input (entry) program for the U.S. Geological Survey modular three-dimensional finite-difference ground-water model, MODFLOW-2000. MFI2K runs on personal computers. MFI2K supports the solute transport and parameter-estimation capabilities that are incorporated in MODFLOW-2000. Data for MODPATH, a particle-tracking program for use with MODFLOW-2000, also can be entered using MFI2K. MFI2K is designed to be easy to use; data are entered interactively through a series of display screens. MFI2K also can be used in conjunction with other data-input programs so that the different parts of a model dataset can be entered using the most suitable program. MFI2K interfaces to an external program for entering or editing two-dimensional arrays and lists of stress data. This report provides instructions for using MFI2K.

Harbaugh, Arlen W.

2002-01-01

364

GROUND TRUTH LOCATIONS USING SYNERGY BETWEEN REMOTE SENSING AND SEISMIC METHODS - APPLICATION TO EARTHQUAKES IN IRAN AND INDIAN SUBCONTINENT  

Microsoft Academic Search

This study aims to establish ground truth locations of moderate to large magnitude earthquakes (4.5?Mw?7) occurring in Iran, and in and around the Indian subcontinent using both seismic and interferometric synthetic aperture radar methods. To this end, we analyzed seismic waveforms and InSAR (Interferometric Synthetic Aperture Radar) data for one large (Mw?6) and two moderate (5.3?Mw ? 5.7) earthquakes in

Chandan K. Saikia; Gene A. Ichinose; Donald V. Helmberger; Mark Simons

365

Analysis of method of polarization surveying of water surface oil pollution  

NASA Technical Reports Server (NTRS)

A method of polarization surveying of oil films on the water surface is analyzed. Model calculations of contrasted oil and water obtained with different orientations of the analyzer are discussed. The model depends on the spectral range, water transparency and oil film, and the selection of observational direction.

Zhukov, B. S.

1979-01-01

366

"How many zombies do you know?" Using indirect survey methods to measure alien attacks and outbreaks  

E-print Network

"How many zombies do you know?" Using indirect survey methods to measure alien attacks applicable to zombies or, for that matter, ghosts, aliens, angels, and other hard-to-reach entities; for example, what if your wife2 is actually a zombie or an alien and you are not aware of the fact. This 2

Gelman, Andrew

367

A new method integration of 3S for mobile landscaping survey and update  

NASA Astrophysics Data System (ADS)

A new method integration of "3S" (geographic information system (GIS), global positioning system (GPS), remote sensing(RS)) for mobile landscaping survey and update is studied in mobile GIS. Several Key technologies are presented in the method, including spatial data model on mobile personal digital assistant (PDA), GPS data difference processing and representation in GIS, GPS coordinate transformation model in mobile GIS, the method of PDA integration of Total Station, the RS image process based on Mobile Device. A new object-oriented spatial data model based on mobile GIS is proposed that has high query and display efficient. A new least squares-based GPS transformation model is further proposed that has fast calculation speed, high adjustment accuracy and thus suitable for mobile GIS. An integrative Application system integration of "3S" for landscaping survey, update and management is therefore developed, including spatial data survey and update mobile GIS, spatial data processing and maintain desktop GIS and spatial data publication WEBGIS. A field test is carried out through this system in Shanghai, and the results show that the proposed model and methods are feasible for mobile landscaping information survey, update and gridding management.

Tian, Gen; Tong, Xiao-hua; Liu, Miao-long

2006-10-01

368

Survey of molecular methods for the typing of wine yeast strains  

Microsoft Academic Search

A survey of the genetic polymorphisms produced by distinct methods was performed in 23 commercial winery yeast strains. Microsatellite typing, using six different loci, an optimized interdelta sequence analysis and restriction fragment length polymorphism of mitochondrial DNA generated by the enzyme HinfI had the same discriminatory power: among the 23 commercial yeast strains, 21 distinct patterns were obtained. Karyotype analysis

Dorit Schuller; Eva Valero; Sylvie Dequin; Margarida Casal

2004-01-01

369

Noise reduction in chaotic time-series data: A survey of common methods  

Microsoft Academic Search

This paper surveys some of the methods that have been suggested for reducing noise in time-series data whose underlying dynamical behavior can be characterized as low-dimensional chaos. Although the procedures differ in details, all of them must solve three basic problems: how to reconstruct an attractor from the data, how to approximate the dynamics in various regions on the attractor,

Eric J. Kostelich; Thomas Schreiber

1993-01-01

370

Critical Survey of Hierarchical Methods for State Estimation of Electric Power Systems  

Microsoft Academic Search

This paper intends to give a unified survey of methods appropriate for solving the state estimation problem in large-scale electric power systems. After a first overview of the various approaches proposed up to now, the most suitable among them are described, examined and compared. The comparisons are carried out on the basis of selected criteria evolving estimation properties of the

T. Van Cutsem; M. Ribbens-Pavella

1983-01-01

371

Examining Stress in Graduate Assistants: Combining Qualitative and Quantitative Survey Methods  

ERIC Educational Resources Information Center

The aim of this study was to employ qualitative and quantitative survey methods in a concurrent mixed model design to assess stressors and strains in graduate assistants. The stressors most frequently reported qualitatively were work overload, interpersonal conflict, and organizational constraints; the most frequently reported psychological…

Mazzola, Joseph J.; Walker, Erin J.; Shockley, Kristen M.; Spector, Paul E.

2011-01-01

372

Survey of modelling methods for wind turbine wakes and wind farms  

Microsoft Academic Search

This article provides an overview and analysis of different wake-modelling methods which may be used as prediction and design tools for both wind turbines and wind farms. We also survey the available data concerning the measurement of wind magnitudes in both single wakes and wind farms, and of loading effects on wind turbines under single- and multiple-wake conditions. The relative

A. Crespo; J. Hernández; S. Frandsen

1999-01-01

373

A Survey of Methods for Computing (un)Stable Manifolds of Vector Fields  

Microsoft Academic Search

The computation of global invariant manifolds has seen renewed interest in recent years. We survey dieren t approaches for computing a global stable or unstable mani- fold of a vector eld, where we concentrate on the case of a two-dimensional manifold. All methods are illustrated with the same example | the two-dimensional stable man- ifold of the origin in the

Bernd Krauskopf; Hinke M. Osinga; Eusebius J. Doedel; M. E. Henderson; John Guckenheimer; A. Vladimirsky; M. Dellnitz; O. Junge

2005-01-01

374

A SURVEY OF METHODS FOR COLOUR IMAGE INDEXING AND RETRIEVAL IN IMAGE DATABASES  

Microsoft Academic Search

Color is a feature of the great majority of content-based image retrieval systems. However the robustness, effectiveness, and efficiency of its use in image indexing are still open issues. This paper provides a comprehensive survey of the methods for color image indexing and retrieval described in the literature. In particular, image preprocessing, the features used to represent color information, and

Raimondo SCHETTINI; Gianluigi CIOCCA; Silvia ZUFFI

2001-01-01

375

A Prediction Method for Job Runtimes on Shared Processors: Survey, Statistical Analysis and New  

E-print Network

A Prediction Method for Job Runtimes on Shared Processors: Survey, Statistical Analysis and New extensive data analysis of job running times generated from different grid nodes. Next, we analyze several. In particular, applications that use significant amounts of processor power for running jobs need effective

van der Mei, Rob

376

A survey of methods and tools used for reliability evaluation of SSCs  

Microsoft Academic Search

The first part of this paper will attempt to point out the principal difficulties inherent to the necessary collection and validation of the needed failure data. The second part will present a survey of the reliability methods and tools presently used at EDF (Électricité de France) to determine reliability parameters and their evolution with age. The conclusion will focus on

André Lannoy

377

Survey of spatial data needs and land use forecasting methods in the electric utility industry  

NASA Technical Reports Server (NTRS)

A representative sample of the electric utility industry in the United States was surveyed to determine industry need for spatial data (specifically LANDSAT and other remotely sensed data) and the methods used by the industry to forecast land use changes and future energy demand. Information was acquired through interviews, written questionnaires, and reports (both published and internal).

1981-01-01

378

Topographical surveys: Classical method versus 3D laser scanning. Case study - An application in civil engineering  

Microsoft Academic Search

The paper describes an experiment which took place in Iasi town, Romania, consisted in two different topographical survey techniques applied for one and the same objective placed in a block within the city (western part) - a thermal power station. The purpose was to compare those methods and to determine which one is proper to be used in this domain

I.-R. Grigoras; A. Covasnianu; G. Plesu; B. Benedict

2009-01-01

379

A Survey of 3D Face Recognition Methods Alize Scheenstra1  

E-print Network

A Survey of 3D Face Recognition Methods Alize Scheenstra1 , Arnout Ruifrok2 , and Remco C. Veltkamp researches in face recognition have been dealing with the challenge of the great variability in head pose is to describe the recent 3D face recognition algorithms. The last few years more and more 2D face recognition

Veltkamp, Remco

380

A Survey of Singular Value Decomposition Methods and Performance Comparison of Some Available Serial Codes  

NASA Technical Reports Server (NTRS)

This contractor report describes a performance comparison of available alternative complete Singular Value Decomposition (SVD) methods and implementations which are suitable for incorporation into point spread function deconvolution algorithms. The report also presents a survey of alternative algorithms, including partial SVD's special case SVD's, and others developed for concurrent processing systems.

Plassman, Gerald E.

2005-01-01

381

National Survey of Psychologists' Test Feedback Training, Supervision, and Practice: A Mixed Methods Study  

Microsoft Academic Search

In this empirical, mixed methods study, we explored test feedback training, supervision, and practice among psychologists, focusing specifically on how feedback is provided to clients and whether feedback skills are taught in graduate programs. Based on a 48.5% return rate, this national survey of clinical, counseling, and school psychologists' suggests psychologists provide test feedback to clients but inconsistently. Most respondents,

Kyle T. Curry; William E. Hanson

2010-01-01

382

Survey of systems safety analysis methods and their application to nuclear waste management systems  

SciTech Connect

This report reviews system safety analysis methods and examines their application to nuclear waste management systems. The safety analysis methods examined include expert opinion, maximum credible accident approach, design basis accidents approach, hazard indices, preliminary hazards analysis, failure modes and effects analysis, fault trees, event trees, cause-consequence diagrams, G0 methodology, Markov modeling, and a general category of consequence analysis models. Previous and ongoing studies on the safety of waste management systems are discussed along with their limitations and potential improvements. The major safety methods and waste management safety related studies are surveyed. This survey provides information on what safety methods are available, what waste management safety areas have been analyzed, and what are potential areas for future study.

Pelto, P.J.; Winegardner, W.K.; Gallucci, R.H.V.

1981-11-01

383

A multireference perturbation method using non-orthogonal Hartree-Fock determinants for ground and excited states  

SciTech Connect

In this article we propose the ?SCF(2) framework, a multireference strategy based on second-order perturbation theory, for ground and excited electronic states. Unlike the complete active space family of methods, ?SCF(2) employs a set of self-consistent Hartree-Fock determinants, also known as ?SCF states. Each ?SCF electronic state is modified by a first-order correction from Møller-Plesset perturbation theory and used to construct a Hamiltonian in a configuration interactions like framework. We present formulas for the resulting matrix elements between nonorthogonal states that scale as N{sub occ}{sup 2}N{sub virt}{sup 3}. Unlike most active space methods, ?SCF(2) treats the ground and excited state determinants even-handedly. We apply ?SCF(2) to the H{sub 2}, hydrogen fluoride, and H{sub 4} systems and show that the method provides accurate descriptions of ground- and excited-state potential energy surfaces with no single active space containing more than 10 ?SCF states.

Yost, Shane R.; Kowalczyk, Tim; Van Voorhis, Troy, E-mail: tvan@mit.edu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States)

2013-11-07

384

Modifications of the U.S. Geological Survey modular, finite-difference, ground-water flow model to read and write geographic information system files  

USGS Publications Warehouse

This report documents modifications to the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model, commonly called MODFLOW, so that it can read and write files used by a geographic information system (GIS). The modified model program is called MODFLOWARC. Simulation programs such as MODFLOW generally require large amounts of input data and produce large amounts of output data. Viewing data graphically, generating head contours, and creating or editing model data arrays such as hydraulic conductivity are examples of tasks that currently are performed either by the use of independent software packages or by tedious manual editing, manipulating, and transferring data. Programs such as GIS programs are commonly used to facilitate preparation of the model input data and analyze model output data; however, auxiliary programs are frequently required to translate data between programs. Data translations are required when different programs use different data formats. Thus, the user might use GIS techniques to create model input data, run a translation program to convert input data into a format compatible with the ground-water flow model, run the model, run a translation program to convert the model output into the correct format for GIS, and use GIS to display and analyze this output. MODFLOWARC, avoids the two translation steps and transfers data directly to and from the ground-water-flow model. This report documents the design and use of MODFLOWARC and includes instructions for data input/output of the Basic, Block-centered flow, River, Recharge, Well, Drain, Evapotranspiration, General-head boundary, and Streamflow-routing packages. The modification to MODFLOW and the Streamflow-Routing package was minimized. Flow charts and computer-program code describe the modifications to the original computer codes for each of these packages. Appendix A contains a discussion on the operation of MODFLOWARC using a sample problem.

Orzol, Leonard L.; McGrath, Timothy S.

1992-01-01

385

Applications of numerical optimization methods to helicopter design problems: A survey  

NASA Technical Reports Server (NTRS)

A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

Miura, H.

1984-01-01

386

Finite difference time domain method forward simulation of complex geoelectricity ground penetrating radar model  

Microsoft Academic Search

The ground penetrating radar (GPR) forward simulation all aims at the singular and regular models, such as sandwich model,\\u000a round cavity, square cavity, and so on, which are comparably simple. But as to the forward of curl interface underground or\\u000a “v” figure complex model, it is difficult to realize. So it is important to forward the complex geoelectricity model. This

Qian-wei Dai; De-shan Feng; Ji-shan He

2005-01-01

387

A method for continuous monitoring of the Ground Reaction Force during daily activity  

NASA Technical Reports Server (NTRS)

Theoretical models and experimental studies of bone remodeling have identified peak cyclic force levels (or cyclic tissue strain energy density), number of daily loading cycles, and load (strain) rate as possible contributors to bone modeling and remodeling stimulus. To test our theoretical model and further investigate the influence of mechanical forces on bone density, we have focused on the calcaneus as a model site loaded by calcaneal surface tractions which are predominantly determined by the magnitude of the external ground reaction force (GRF).

Whalen, Robert; Quintana, Jason; Emery, Jeff

1993-01-01

388

Method for line-ground fault detection in variable frequency drives  

Microsoft Academic Search

An Industrial-Power-Converter-System (IPCS) is a system made up of several power converters, such as Adjustable Speed Drives (ASDs), filters, and reactive power-compensation components. An IPCS requires the ability to accurately detect and isolate electric faults to avoid further compromising the integrity of the system. A rather common type of electric fault is the line-to-ground fault. It can occur either from

Carlos D. Rodriguez-Valdez; Rangarajan M. Tallam; Russ J. Kerkman

2011-01-01

389

A field trial of a survey method for estimating the coverage of selective feeding programmes.  

PubMed Central

OBJECTIVE: To test a survey method for estimating the coverage of selective feeding programmes in humanitarian emergencies. METHODS: The trial survey used a stratified design with strata that were defined using the centric systematic area sample method. Thirty 100 km2 quadrats were sampled. The communities located closest to the centre of each quadrat were sampled using a case-finding approach. FINDINGS: The method proved simple and rapid to implement and allowed overall and per-quadrat coverage to be estimated. Overall coverage was 20.0% (95% confidence intervals, 13.8-26.3%). Per-quadrat coverage ranged from zero (in nine quadrats) to 50% (in one quadrat). Coverage was highest in the quadrats closest to therapeutic feeding centres and in quadrats containing major roads leading to the towns in which therapeutic feeding centres were located. CONCLUSION: The method should be used, in preference to WHO Expanded Programme on Immunization (EPI)-derived survey methods, for estimating the coverage of selective feeding programmes. Its use should also be considered when evaluating the coverage of other selective entry programmes or when coverage is likely to be spatially inhomogeneous. PMID:15682245

Myatt, Mark; Feleke, Teshome; Sadler, Kate; Collins, Steve

2005-01-01

390

3D Monitoring under the Keciova Mosque (Casbah-Algier, Algeria) with Ground Penetrating Radar Method  

NASA Astrophysics Data System (ADS)

Keciova (Ketchaoua) Mosque, in Casbah-Algiers, the capital of Algeria, is a UNESCO World Heritage Site. Keciova Mosque was originally built in 1612 by the Ottoman Empire. A RAMAC CU II GPR system and a 250 MHz shielded antenna have been employed inside of the Mosque including the Cathedral and inside of the burial chambers under the Cathedral Site on parallel profiles spaced approximately 0.30 m apart to measure data. After applying standard two-dimensional (2D) and three dimensional (3D) imaging techniques, transparent 3D imaging techniques have been used to photograph the foundational infrastructures, buried remains and safety problems of the Mosque. The results showed that we obtained 3D GPR visualization until 12.0 m in depth. Firstly we imaged the base floor including corridors. Then we monitored buried remains under the first ground level between 5.0-7.0 m in depths. Finally we indicated 3D GPR photographs a spectacular protected buried old mosque structures under the second ground level between 9.0-12.0 m in depths. This project has been supported by Republic of Turkey Prime Ministry Turkish Cooperation and Coordination Agency (TIKA). This study is a contribution to the EU funded COST action TU1208, "Civil Engineering Applications of Ground penetrating Radar".

Kadioglu, Selma; Kagan Kadioglu, Yusuf; Deniz, Kiymet; Akin Akyol, Ali

2014-05-01

391

A Method for Calculating the Probability of Successfully Completing a Rocket Propulsion Ground Test  

NASA Technical Reports Server (NTRS)

Propulsion ground test facilities face the daily challenge of scheduling multiple customers into limited facility space and successfully completing their propulsion test projects. Over the last decade NASA s propulsion test facilities have performed hundreds of tests, collected thousands of seconds of test data, and exceeded the capabilities of numerous test facility and test article components. A logistic regression mathematical modeling technique has been developed to predict the probability of successfully completing a rocket propulsion test. A logistic regression model is a mathematical modeling approach that can be used to describe the relationship of several independent predictor variables X(sub 1), X(sub 2),.., X(sub k) to a binary or dichotomous dependent variable Y, where Y can only be one of two possible outcomes, in this case Success or Failure of accomplishing a full duration test. The use of logistic regression modeling is not new; however, modeling propulsion ground test facilities using logistic regression is both a new and unique application of the statistical technique. Results from this type of model provide project managers with insight and confidence into the effectiveness of rocket propulsion ground testing.

Messer, Bradley

2007-01-01

392

Single-Event Effects Ground Testing and On-Orbit Rate Prediction Methods: The Past, Present and Future  

NASA Technical Reports Server (NTRS)

Over the past 27 years, or so, increased concern over single event effects in spacecraft systems has resulted in research, development and engineering activities centered around a better understanding of the space radiation environment, single event effects predictive methods, ground test protocols, and test facility developments. This research has led to fairly well developed methods for assessing the impact of the space radiation environment on systems that contain SEE sensitive devices and the development of mitigation strategies either at the system or device level.

Reed, Robert A.; Kinnison, Jim; Pickel, Jim; Buchner, Stephen; Marshall, Paul W.; Kniffin, Scott; LaBel, Kenneth A.

2003-01-01

393

Conduct a state-of-the-art survey of existing knowledge for the design of ground-source heat pumps  

NASA Astrophysics Data System (ADS)

Horizontal serpentine coils have been and are at present the most common coil configuration. Best design data exist for horizontal coils in heating only applications with moist soil. Applications in dry soil or where significant summer cooling is required are not as well understood at this time. A seasonal performance factor of about 3.0 can be expected for a properly designed and installed residential ground-coupled heat-pump system. Long-term durability of buried steel and cooper tubing has been demonstrated. Life expectancy of thin-walled polyethylene tubing in the heating-only application is expected to be equally as good: however, present experience is limited to less than five years. In the cooling application with heat-rejection temperatures exceeding 100 F, some cracking has been experienced upon subsequent cool-down for heating operation due to localized stresses induced by conformity of the tubing to bedding material (stones) when hot. Receding of the soil from the pipe after a period of several years was experienced in the late 1940's. An understanding of this phenomenon may be crucial to the long-term operating success of these systems.

Ball, D. A.

1982-03-01

394

The comparison of three methods for isolation of Arcobacter spp. in raw ground pork  

E-print Network

. The prevalence in pork has been found to be relatively low, typically 5%, using standard isolation methods. These methods include the deBoer method, Collins method and a modified version called the Direct Collins method. In this experiment, these broth and agar...

Ohlendorf, Dawn Suzanne

2000-01-01

395

A thermal profile method to identify potential ground-water discharge areas and preferred salmonid habitats for long river reaches  

USGS Publications Warehouse

The thermal regime of riverine systems is a major control on aquatic ecosystems. Ground water discharge is an important abiotic driver of the aquatic ecosystem because it provides preferred thermal structure and habitat for different types of fish at different times in their life history. In large diverse river basins with an extensive riverine system, documenting the thermal regime and ground-water discharge is difficult and problematic. A method was developed to thermally profile long (5-25 kilometers) river reaches by towing in a Lagrangian framework one or two probes that measure temperature, depth, and conductivity. One probe is towed near the streambed and, if used, a second probe is towed near the surface. The probes continuously record data at 1-3-second intervals while a Global Positioning System logs spatial coordinates. The thermal profile provides valuable information about spatial and temporal variations in habitat, and, notably, indicates ground-water discharge areas. This method was developed and tested in the Yakima River Basin, Washington, in summer 2001 during low flows in an extreme drought year. The temperature profile comprehensively documents the longitudinal distribution of a river's temperature regime that cannot be captured by fixed station data. The example profile presented exhibits intra-reach diversity that reflects the many factors controlling the temperature of a parcel of water as it moves downstream. Thermal profiles provide a new perspective on riverine system temperature regimes that represent part of the aquatic habitat template for lotic community patterns.

Vaccaro, J.J.; Maloy, K.J.

2006-01-01

396

Multidisciplinary teams, and parents, negotiating common ground in shared-care of children with long-term conditions: A mixed methods study  

PubMed Central

Background Limited negotiation around care decisions is believed to undermine collaborative working between parents of children with long-term conditions and professionals, but there is little evidence of how they actually negotiate their respective roles. Using chronic kidney disease as an exemplar this paper reports on a multi-method study of social interaction between multidisciplinary teams and parents as they shared clinical care. Methods Phases 1 and 2: a telephone survey mapping multidisciplinary teams’ parent-educative activities, and qualitative interviews with 112 professionals (Clinical-psychologists, Dietitians, Doctors, Nurses, Play-specialists, Pharmacists, Therapists and Social-workers) exploring their accounts of parent-teaching in the 12 British children’s kidney units. Phase 3: six ethnographic case studies in two units involving observations of professional/parent interactions during shared-care, and individual interviews. We used an analytical framework based on concepts drawn from Communities of Practice and Activity Theory. Results Professionals spoke of the challenge of explaining to each other how they are aware of parents’ understanding of clinical knowledge, and described three patterns of parent-educative activity that were common across MDTs: Engaging parents in shared practice; Knowledge exchange and role negotiation, and Promoting common ground. Over time, professionals had developed a shared repertoire of tools to support their negotiations with parents that helped them accomplish common ground during the practice of shared-care. We observed mutual engagement between professionals and parents where a common understanding of the joint enterprise of clinical caring was negotiated. Conclusions For professionals, making implicit knowledge explicit is important as it can provide them with a language through which to articulate more clearly to each other what is the basis of their intuition-based hunches about parents’ support needs, and may help them to negotiate with parents and accelerate parents’ learning about shared caring. Our methodology and results are potentially transferrable to shared management of other conditions. PMID:23835151

2013-01-01

397

Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches.  

PubMed

In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq (137)Cs within large areas (10-20 km(2)h(-1)), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1-2 km(2) h(-1) can detect buried (137)Cs sources of 0.5MBq or greater activity. A survey design to detect 100 kBq (137)Cs sources at 10 cm depth has also been defined, requiring surveys at <15m ground clearance and <2 ms(-1) ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. PMID:22947616

Cresswell, A J; Sanderson, D C W

2012-10-15

398

Detecting population declines over large areas with presence-absence, time-to-encounter, and count survey methods.  

PubMed

Ecologists often discount presence-absence surveys as a poor way to gain insight into population dynamics, in part because these surveys are not amenable to many standard statistical tests. Still, presence-absence surveys are sometimes the only feasible alternative for monitoring large areas when funds are limited, especially for sparse or difficult-to-detect species. I undertook a detailed simulation study to compare the power of presence-absence, count, and time-to-encounter surveys to detect regional declines in a population. I used a modeling approach that simulates both population numbers and the monitoring process, accounting for observation and other measurement errors. In gauging the efficacy of presence-absence surveys versus other approaches, I varied the number of survey sites, the spatial variation in encounter rate, the mean encounter rate, and the type of population loss. My results showed that presence-absence data can be as or more powerful than count data in many cases. Quantitative guidelines for choosing between presence-absence surveys and count surveys depend on the biological and logistical constraints governing a conservation monitoring situation. Generally, presence-absence surveys work best when there is little variability in abundance among the survey sites, the organism is rare, and the species is difficult to detect so that the time spent getting to each survey site is less than or equal to the time spent surveying each site. Count surveys work best otherwise. I present a case study with count data on the Northern Flicker (Colaptes auratus) from the North American Breeding Bird Survey to illustrate how the method might be used with field-survey data. The case study demonstrates that a count survey would be the most cost-effective design but would entail reduction in the number of sites. If this site reduction is not desirable, a presence-absence survey would be the most cost-effective survey. PMID:16909580

Pollock, Jacob E

2006-06-01

399

Recovery Method Development of Sodium Chloride-Susceptible Methicillin-Resistant Staphylococcus aureus Isolates from Ground Pork Samples.  

PubMed

The growth of certain methicillin-resistant Staphylococcus aureus (MRSA) isolates could be inhibited by NaCl higher than 2.5%. The objective of this study was to develop an enrichment method to recover NaCl-susceptible MRSA isolates from meat samples. The growth of 12 MRSA and 10 non-MRSA strains was measured in Mueller-Hinton (MH) broth supplemented with 2.5%, 4%, 6.5%, and 7.5% NaCl. Selective agents, including aztreonam, polymyxin B, NaCl, nalidixic acid, and NaN3, were determined for their inhibitory effect to MRSA and non-MRSA strains in MH broth. Based on these data, a two-step enrichment method was developed to recover both NaCl-susceptible and -resistant MRSA isolates in meat products. Comparing to the enrichment method that only used MH broth supplemented with 6.5% NaCl, five additional NaCl-susceptible MRSA isolates were recovered from 92 retail ground pork samples by this newly developed two-step enrichment method. To the best of our knowledge, this is the first study that considers NaCl-susceptible MRSA recovery from ground pork samples. The application of this new enrichment method might expand the diversity of MRSA isolates recovered from various samples. PMID:25153854

Pang, Lu; Luo, Yanping; Gu, Yihai; Xu, Xiao; Xu, Jin; Zhang, Fenglan; Cui, Shenghui

2015-02-01

400

Determination of land subsidence related to ground-water-level declines using Global Positioning System and leveling surveys in Antelope Valley, Los Angeles and Kern counties, California, 1992  

USGS Publications Warehouse

A large-scale, land-subsidence monitoring network for Antelope Valley, California, was established, and positions and elevations for 85 stations were measured using Global Positioning System geodetic surveying in spring 1992. The 95-percent confidence (2@) level of accuracy for the elevations calculated for a multiple-constraint adjustment generally ranged from +0.010 meter (0.032 foot) to +0.024 meter (0.078 foot). The magnitudes and rates of land subsidence as of 1992 were calculated for several periods for 218 bench marks throughout Antelope Valley. The maximum measured magnitude of land subsidence that occurred between 1926 and 1992 was 6.0 feet (1.83 meters) at BM 474 near Avenue I and Sierra Highway. Measured or estimated subsidence of 2-7 feet (.61-2.l3 meters) had occurred in a 210- square-mile (542-square-kilometer) area of Antelope Valley, generally bounded by Avenue K, Avenue A, 90th Street West, and 120th Street East, during the same period. Land subsidence in Antelope Valley is caused by aquifer-system compaction, which is related to ground-water-level declines and the presence of fine-grained, compressible sediments. Comparison of potentiomethric-surface, water-level decline, and subsidence-rate maps for several periods indicated a general correlation between water-level declines and the distribution and rate of subsidence in the Lancaster ground-water subbasin. A conservative estimate of the amount of the reduction in storage capacity of the aquifer system in the Lancaster subbasin is about 50,000 acre-feet in the area that has been affected by more than one foot (.30 meters) of subsidence as of 1992. Information on the history of ground-water levels and the distribution and thickness of fine-grained compressible sediments can be used to mitigate continued land subsidence. Future monitoring of ground-water levels and land-surface elevations in subsidence-sensitive regions of Antelope Valley may be an effective means to manage land subsidence.

Ikehara, M.E.; Phillips, S.P.

1994-01-01

401

A Method for Calculating the Probability of Successfully Completing a Rocket Propulsion Ground Test  

NASA Technical Reports Server (NTRS)

Propulsion ground test facilities face the daily challenges of scheduling multiple customers into limited facility space and successfully completing their propulsion test projects. Due to budgetary and schedule constraints, NASA and industry customers are pushing to test more components, for less money, in a shorter period of time. As these new rocket engine component test programs are undertaken, the lack of technology maturity in the test articles, combined with pushing the test facilities capabilities to their limits, tends to lead to an increase in facility breakdowns and unsuccessful tests. Over the last five years Stennis Space Center's propulsion test facilities have performed hundreds of tests, collected thousands of seconds of test data, and broken numerous test facility and test article parts. While various initiatives have been implemented to provide better propulsion test techniques and improve the quality, reliability, and maintainability of goods and parts used in the propulsion test facilities, unexpected failures during testing still occur quite regularly due to the harsh environment in which the propulsion test facilities operate. Previous attempts at modeling the lifecycle of a propulsion component test project have met with little success. Each of the attempts suffered form incomplete or inconsistent data on which to base the models. By focusing on the actual test phase of the tests project rather than the formulation, design or construction phases of the test project, the quality and quantity of available data increases dramatically. A logistic regression model has been developed form the data collected over the last five years, allowing the probability of successfully completing a rocket propulsion component test to be calculated. A logistic regression model is a mathematical modeling approach that can be used to describe the relationship of several independent predictor variables X(sub 1), X(sub 2),..,X(sub k) to a binary or dichotomous dependent variable Y, where Y can only be one of two possible outcomes, in this case Success or Failure. Logistic regression has primarily been used in the fields of epidemiology and biomedical research, but lends itself to many other applications. As indicated the use of logistic regression is not new, however, modeling propulsion ground test facilities using logistic regression is both a new and unique application of the statistical technique. Results from the models provide project managers with insight and confidence into the affectivity of rocket engine component ground test projects. The initial success in modeling rocket propulsion ground test projects clears the way for more complex models to be developed in this area.

Messer, Bradley P.

2004-01-01

402

Is Thiel’s embalming method widely known? A world survey about its use  

Microsoft Academic Search

Introduction  Thiel’s embalming technique, first described by Thiel in 1992, conserves texture and colour in cadavers close to that observed\\u000a in the living. It would appear that few anatomy laboratories use this method, and literature describing its use worldwide\\u000a is sparse. The aim of our study was to conduct a worldwide survey on the use of this method.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A questionnaire was

Mehdi Benkhadra; Julien Gérard; Denis Genelot; Pierre Trouilloud; Claude Girard; Friedrich Anderhuber; Georg Feigl

2011-01-01

403

A Survey of Symplectic and Collocation Integration Methods for Orbit Propagation  

NASA Technical Reports Server (NTRS)

Demands on numerical integration algorithms for astrodynamics applications continue to increase. Common methods, like explicit Runge-Kutta, meet the orbit propagation needs of most scenarios, but more specialized scenarios require new techniques to meet both computational efficiency and accuracy needs. This paper provides an extensive survey on the application of symplectic and collocation methods to astrodynamics. Both of these methods benefit from relatively recent theoretical developments, which improve their applicability to artificial satellite orbit propagation. This paper also details their implementation, with several tests demonstrating their advantages and disadvantages.

Jones, Brandon A.; Anderson, Rodney L.

2012-01-01

404

Does survey method bias the description of northern goshawk nest-site structure?  

USGS Publications Warehouse

Past studies on the nesting habitat of northern goshawks (Accipiter gentilis) often relied on nests found opportunistically, either during timber-sale operations, by searching apparently 'good' goshawk habitat, or by other search methods where areas were preselected based on known forest conditions. Therefore, a bias in the characterization of habitat surrounding northern goshawk nest sites may exist toward late-forest structure (large trees, high canopy closure). This potential problem has confounded interpretation of data on nesting habitat of northern goshawks and added to uncertainty in the review process to consider the species for federal listing as threatened or endangered. Systematic survey methods, which strive for complete coverage of an area and often use broadcasts of conspecific calls, have been developed to overcome these potential biases, but no study has compared habitat characteristics around nests found opportunistically with those found systematically. We compared habitat characteristics in a 0.4-ha area around nests found systematically (n = 27) versus those found opportunistically (n = 22) on 3 national forests in eastern Oregon. We found that both density of large trees (systematic: x?? = 16.4 ?? 3.1 trees/ha; x?? ?? SE; opportunistic: x?? = 21.3 ?? 3.2; P = 0.56) and canopy closure (systematic: x?? = 72 ?? 2%; opportunistic: x?? = 70 ?? 2%; P = 0.61) were similar around nests found with either search method. Our results diminish concern that past survey methods mischaracterized northern goshawk nest-site structure. However, because northern goshawks nest in a variety of forest cover types with a wide range of structural characteristics, these results do not decrease the value of systematic survey methods in determining the most representative habitat descriptions for northern goshawks. Rigorous survey protocols allow repeatability and comparability of monitoring efforts and results over time.

Daw, S.K.; DeStefano, S.; Steidl, R.J.

1998-01-01

405

Determination of chlorophyll photosynthetic potential in vegetation using ground-based and satellite methods  

NASA Astrophysics Data System (ADS)

An integrated study of the vegetation in the south of Krasnoyarsk Territory was carried out on the basis of ground-based and satellite remote measurements. The research objects were agricultural crops (wheat, oats) during the vegetation period. The satellite calculations were based on the data having high (Landsat 7 ETM+) and medium spatial resolution (Terra-Modis). Both kinds of data were used to calculate the chlorophyll photosynthetic potential (CPSP) as the area of the triangle made up by the reflection values in the green, red and near infrared spectrum regions. The connection was determined between the ground-based and satellite measurements of CPSP. Having analyzed the remote field and satellite measurements of the brightness spectral ratios of agricultural crops during vegetation, we showed the possibility of estimation of structural changes in the near infrared spectrum region. A lack or excess of water in plants causes structural changes in their phytoelements, which affects their reflectance. We showed the possibility of assessing morpho-physiological changes and species composition of crops. We determined the correlation between the spectral reflectance in various crops with chlorophyll content in plants and biomass changes.

Botvich, Irina; Alexander, Sidko; Pisman, Tamara; Shevyrnogov, Anatoly

406

Method and Apparatus for Monitoring of Daily Activity in Terms of Ground Reaction Forces  

NASA Technical Reports Server (NTRS)

A device to record and analyze habitual daily activity in terms of the history of gait-related musculoskeletal loading is disclosed. The device consists of a pressure-sensing insole placed into the shoe or embedded in a shoe sole, which detects contact of the foot with the ground. The sensor is coupled to a portable battery-powered digital data logger clipped to the shoe or worn around the ankle or waist. During the course of normal daily activity, the system maintains a record of time-of-occurrence of all non-spurious foot-down and lift-off events. Off line, these data are filtered and converted to a history of foot-ground contact times, from which measures of cumulative musculoskeletal loading, average walking- and running-specific gait speed, total time spent walking and running, total number of walking steps and running steps, and total gait-related energy expenditure are estimated from empirical regressions of various gait parameters to the contact time reciprocal. Data are available as cumulative values or as daily averages by menu selection. The data provided by this device are useful for assessment of musculoskeletal and cardiovascular health and risk factors associated with habitual patterns of daily activity.

Whalen, Robert T. (Inventor); Breit, Gregory A. (Inventor)

2001-01-01

407

A simple method to assess unsaturated zone time lag in the travel time from ground surface to receptor.  

PubMed

In contaminant travel from ground surface to groundwater receptors, the time taken in travelling through the unsaturated zone is known as the unsaturated zone time lag. Depending on the situation, this time lag may or may not be significant within the context of the overall problem. A method is presented for assessing the importance of the unsaturated zone in the travel time from source to receptor in terms of estimates of both the absolute and the relative advective times. A choice of different techniques for both unsaturated and saturated travel time estimation is provided. This method may be useful for practitioners to decide whether to incorporate unsaturated processes in conceptual and numerical models and can also be used to roughly estimate the total travel time between points near ground surface and a groundwater receptor. This method was applied to a field site located in a glacial aquifer system in Ontario, Canada. Advective travel times were estimated using techniques with different levels of sophistication. The application of the proposed method indicates that the time lag in the unsaturated zone is significant at this field site and should be taken into account. For this case, sophisticated and simplified techniques lead to similar assessments when the same knowledge of the hydraulic conductivity field is assumed. When there is significant uncertainty regarding the hydraulic conductivity, simplified calculations did not lead to a conclusive decision. PMID:23274409

Sousa, Marcelo R; Jones, Jon P; Frind, Emil O; Rudolph, David L

2013-01-01

408

Methods for implementing a medicine outlet survey: lessons from the anti-malarial market  

PubMed Central

Background In recent years an increasing number of public investments and policy changes have been made to improve the availability, affordability and quality of medicines available to consumers in developing countries, including anti-malarials. It is important to monitor the extent to which these interventions are successful in achieving their aims using quantitative data on the supply side of the market. There are a number of challenges related to studying supply, including outlet sampling, gaining provider cooperation and collecting accurate data on medicines. This paper provides guidance on key steps to address these issues when conducting a medicine outlet survey in a developing country context. While the basic principles of good survey design and implementation are important for all surveys, there are a set of specific issues that should be considered when conducting a medicine outlet survey. Methods This paper draws on the authors’ experience of designing and implementing outlet surveys, including the lessons learnt from ACTwatch outlet surveys on anti-malarial retail supply, and other key studies in the field. Key lessons and points of debate are distilled around the following areas: selecting a sample of outlets; techniques for collecting and analysing data on medicine availability, price and sales volumes; and methods for ensuring high quality data in general. Results and conclusions The authors first consider the inclusion criteria for outlets, contrasting comprehensive versus more focused approaches. Methods for developing a reliable sampling frame of outlets are then presented, including use of existing lists, key informants and an outlet census. Specific issues in the collection of data on medicine prices and sales volumes are discussed; and approaches for generating comparable price and sales volume data across products using the adult equivalent treatment dose (AETD) are explored. The paper concludes with advice on practical considerations, including questionnaire design, field worker training, and data collection. Survey materials developed by ACTwatch for investigating anti-malarial markets in sub-Saharan Africa and Asia provide a helpful resource for future studies in this area. PMID:23383972

2013-01-01

409

New Statistical Methods for Analysis of Large Surveys: Distributions and Correlations  

E-print Network

The aim of this paper is to describe new statistical methods for determination of the correlations among and distributions of physical parameters from a multivariate data with general and arbitrary truncations and selection biases. These methods, developed in collaboration with B. Efron of Department of Statistics at Stanford, can be used for analysis of combined data from many surveys with different and varied observational selection criteria. For clarity we will use the luminosity function of AGNs and its evolution to demonstrate the methods. We will first describe the general features of data truncation and present a brief review of past methods of analysis. Then we will describe the new methods and results from simulations testing their accuracy. Finally we will present the results from application of the methods to a sample of quasars.

Vahe' Petrosian

2001-12-19

410

Large-Scale Urban Modeling by Combining Ground Level Panoramic and Aerial Imagery  

E-print Network

. The method automatically extracts roof corners in the ground images and registers the panorama to the aerial techniques such as stereoscopic aer- ial images and airborne LIDAR. A good survey is presented in [8

Shahabi, Cyrus

411

An Internet-based survey method for college student drinking research  

Microsoft Academic Search

The purpose of this study was to describe and assess the utility of an Internet-based survey method for characterizing the alcohol consumption of college students. After extensive pilot research, a random sample of 1910 students aged 16–29 years was invited to complete a questionnaire, consisting of a series of web-pages linked to a relational database on a secure web-site. A

Kypros Kypri; Stephen J. Gallagher; Martine L. Cashell-Smith

2004-01-01

412

Precision grid survey apparatus and method for the mapping of hidden ferromagnetic structures  

DOEpatents

The present invention is for a precision grid surveyor having a stationary unit and a roving unit. The stationary unit has a light source unit that emits a light beam and a rotator to project the light beam toward detectors on a roving unit. The roving unit moves over an area to be surveyed. Further the invention is for a method of mapping details of hidden underground iron pipelines, and more particularly the location of bell joints.

von Wimmerspeg, Udo

2004-11-16

413

The 2005 Chios ancient shipwreck survey: New methods for underwater archaeology  

Microsoft Academic Search

In 2005 a Greek and American interdisciplinary team investigated two shipwrecks off the coast of Chios dating to the 4th-century b.c. and the 2nd\\/1st century. The project pioneered archaeological methods of precision acoustic, digital image, and chemical survey using an autonomous underwater vehicle (AUV) and in-situ sensors, increasing the speed of data acquisition while decreasing costs. The AUV recorded data

Brendan P. Foley; Katerina DellaPorta; Dimitris Sakellariou; Brian S. Bingham; Richard Camilli; Ryan M. Eustice; Dionysis Evagelistis; Vicki L. Ferrini; Kostas Katsaros; Dimitris Kourkoumelis; Aggelos Mallios; Paraskevi Micha; David A. Mindell; Christopher Roman; Hanumant Singh; David S. Switzer; Theotokis Theodoulou

2009-01-01

414

Ground-state properties of LiH by reptation quantum Monte Carlo methods.  

PubMed

We apply reptation quantum Monte Carlo to calculate one- and two-electron properties for ground-state LiH, including all tensor components for static polarizabilities and hyperpolarizabilities to fourth-order in the field. The importance sampling is performed with a large (QZ4P) STO basis set single determinant, directly obtained from commercial software, without incurring the overhead of optimizing many-parameter Jastrow-type functions of the inter-electronic and internuclear distances. We present formulas for the electrical response properties free from the finite-field approximation, which can be problematic for the purposes of stochastic estimation. The ?, ?, A and C polarizability values are reasonably consistent with recent determinations reported in the literature, where they exist. A sum rule is obeyed for components of the B tensor, but B(zz,zz) as well as ?(zzz) differ from what was reported in the literature. PMID:21445452

Ospadov, Egor; Oblinsky, Daniel G; Rothstein, Stuart M

2011-05-01

415

Grounding electrode and method of reducing the electrical resistance of soils  

DOEpatents

A first solution of an electrolyte is injected underground into a volume of soil having negative surface charges on its particles. A cationic surfactant suspended in this solution neutralizes these surface charges of the soil particles within the volume. Following the first solution, a cationic asphalt emulsion suspended in a second solution is injected into the volume. The asphalt emulsion diffuses through the volume and electrostatically bonds with additional soil surrounding the volume such that an electrically conductive water repellant shell enclosing the volume is formed. This shell prevents the leaching of electrolyte from the volume into the additional soil. The second solution also contains a dissolved deliquescent salt which draws water into the volume prior to the formation of the shell. When electrically connected to an electrical installation such as a power line tower, the volume constitutes a grounding electrode for the tower.

Koehmstedt, Paul L. (Richland, WA)

1980-01-01

416

Basis and methods of NASA airborne topographic mapper lidar surveys for coastal studies  

USGS Publications Warehouse

This paper provides an overview of the basic principles of airborne laser altimetry for surveys of coastal topography, and describes the methods used in the acquisition and processing of NASA Airborne Topographic Mapper (ATM) surveys that cover much of the conterminous US coastline. This form of remote sensing, also known as "topographic lidar", has undergone extremely rapid development during the last two decades, and has the potential to contribute within a wide range of coastal scientific investigations. Various airborne laser surveying (ALS) applications that are relevant to coastal studies are being pursued by researchers in a range of Earth science disciplines. Examples include the mapping of "bald earth" land surfaces below even moderately dense vegetation in studies of geologic framework and hydrology, and determination of the vegetation canopy structure, a key variable in mapping wildlife habitats. ALS has also proven to be an excellent method for the regional mapping of geomorphic change along barrier island beaches and other sandy coasts due to storms or long-term sedimentary processes. Coastal scientists are adopting ALS as a basic method in the study of an array of additional coastal topics. ALS can provide useful information in the analysis of shoreline change, the prediction and assessment of landslides along seacliffs and headlands, examination of subsidence causing coastal land loss, and in predicting storm surge and tsunami inundation.

Brock, John C.; Wright, C. Wayne; Sallenger, Asbury H.; Krabill, William B.; Swift, Robert N.

2002-01-01

417

Chloride mass-balance method for estimating ground water recharge in arid areas: Examples from western Saudi Arabia  

USGS Publications Warehouse

The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation - a range consistent with recharge rates found in other arid and semi-arid areas of the earth.

Bazuhair, A.S.; Wood, W.W.

1996-01-01

418

Assessing internet survey data collection methods with ethnic nurse shift workers.  

PubMed

An increasing number of ethnic minorities are expected to enter the United States workforce based on projected demographic changes. This includes American Indian/Alaskan Native (AI/AN) nurses. Sociocultural influences on sleep disturbances, sleepiness, and other aspects related to shift-work tolerance are of unrecognized importance. More minority nurses are needed to provide culturally congruent care; however, AI/AN nurses represent less than 1% of nurses located throughout the American workforce. This article aims to verify the feasibility of Internet data collection (Web-based survey) methods and instrument stability as the first part of a two-phase study comparing individual differences and shift-work-related sleep disturbances between AI/AN and White non-Hispanic (WNH) nurses. In the first phase, an Internet survey was used to reach a cross-section of AI/AN and WNH nurses. The on-line survey was composed of accepted shift-work-related instruments. Items estimating sleep disturbances, sociocultural choices, time awareness, polychronicity, morningness/ eveningness, ethnic identity, and demographic questions were asked. The survey was linked to a series of Web pages describing the study purpose, inclusion and exclusion criteria, consent form, Web survey, and the second phase of the study in which subjects were invited to participate in actigraphy measurements. The survey was pilot-tested for error codes, item confusion, length, and completion time. Forced-answer questions were added asking ethnicity, age group, license type, state where licensed, and legal name on nursing license before accessing the survey. Data were saved periodically, cued by the word "continue." The database was located on a secure server and password protected. Nurses were recruited using published articles and printed advertisements, hospital e-mail systems, national nursing organization Web sites (minoritynurse.com; NANAINA.org), nursing Web site discussion groups, snow-balling, and word of mouth. The site was accessed 656 times with the Internet survey being completed by 138 WNH and 56 AI/AN nurses meeting the inclusion criteria. Except for the polychronicity measure (PAI3), instruments measuring time awareness, chronotype, and situational sleepiness achieved acceptable reliability coefficients with Internet data collection. Using pull-down menus would improve questions asking specific times. Internet data collection with different ethnic groups is possible; however, accessing the target population may be difficult. Despite extensive recruitment efforts, few AI/AN nurses participated. Computer literacy and failing to relate to the study's purpose may have limited the interest of the AI/AN nurses. It is possible to recruit nurse shift workers and collect individual difference and sleep disturbance data through the Internet; however, the researcher must remain vigilant throughout the process. PMID:15646245

Hobbs, Barbara Betz; Farr, Lynne A

2004-01-01

419

Multidisciplinary Studies of the Fate and Transport of Contaminants in Ground Water at the U.S. Geological Survey Cape Cod Toxic Substances Hydrology Program Research Site, Massachusetts  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey conducts multidisciplinary research on the physical, chemical, and microbiological processes affecting ground-water contaminants of global concern at its Cape Cod Toxic Substances Hydrology Program site in Massachusetts, USA. The work centers on a 6-kilometer-long plume of treated wastewater in a glacial sand and gravel aquifer. The plume is characterized by distinct geochemical zones caused by the biodegradation of organic materials in treated wastewater that was disposed to the aquifer by rapid infiltration during the period 1936-95. A core group of hydrogeologists, geochemists, microbiologists, and geophysicists has been involved in the research effort for more than two decades. The effort has been enhanced by stable funding, a readily accessible site, a relatively simple hydrologic setting, and logistical support from an adjacent military base. The research team uses a three-part approach to plan and conduct research at the site. First, detailed spatial and temporal monitoring of the plume since the late 1970s provides field evidence of important contaminant-transport processes and provides the basis for multidisciplinary, process-oriented studies. Second, ground-water tracer experiments are conducted in various geochemical zones in the plume to study factors that control the rate and extent of contaminant transport. Several arrays of multilevel sampling devices, including an array with more than 15,000 individual sampling points, are used to conduct these experiments. Plume-scale (kilometers) and tracer-test-scale (1- 100 meters) studies are complemented by laboratory experiments and mathematical modeling of flow and reactive transport. Third, results are applied to the treated-wastewater plume, other contaminant plumes at the military base, and other sites nationally to evaluate the applicability of the findings and to point toward further research. Examples of findings to date include that (1) macrodispersivity can be related to hydraulic- conductivity variations as predicted by stochastic models; (2) mobile and attached bacteria and protists comprise a microbial community that plays a predominant role in geochemical processes in the subsurface, (3) estimated rates of geochemical processes are dependent on measurement scale (for example, laboratory columns versus field tracer tests); and (4) geochemical zones in a contaminant plume can persist for decades after the contaminant source has been removed and conservative species have been flushed from the area by natural ground-water flow.

Leblanc, D. R.; Smith, R. L.; Kent, D. B.; Barber, L. B.; Harvey, R. W.

2008-12-01

420

Novel survey method finds dramatic decline of wild cotton-top tamarin population.  

PubMed

The cotton-top tamarin (Saguinus oedipus) is a critically endangered primate, endemic to the tropical forests of Colombia. Population monitoring is essential to evaluate the success of conservation efforts, yet standard survey methods are ineffective because animals flee silently before they are seen. We developed a novel technique that combines the use of playbacks of territorial vocalizations with traditional transect surveys. We used remote sensing to identify potential habitat within the species' historic range, and visited the 27% that we could survey safely. Of this, only 99 km(2) was extant forest, containing an estimated 2,045 animals (95% confidence interval 1,587-2,634). Assuming comparable densities in non-surveyed areas, approximately 7,394 wild cotton-top tamarins remain in Colombia. With 20-30,000 animals exported to the United States in the late 1960s, this must represent a precipitous decline. Habitat destruction and capture for the illegal pet trade are ongoing. Urgent conservation measures are required to prevent extinction in the wild. PMID:20975684

Savage, Anne; Thomas, Len; Leighty, Katherine A; Soto, Luis H; Medina, Felix S

2010-01-01

421

Ground difference compensating system  

SciTech Connect

A method of ground level compensation includes measuring a voltage of at least one signal with respect to a primary ground potential and measuring, with respect to the primary ground potential, a voltage level associated with a secondary ground potential. A difference between the voltage level associated with the secondary ground potential and an expected value is calculated. The measured voltage of the at least one signal is adjusted by an amount corresponding to the calculated difference.

Johnson, Kris W.; Akasam, Sivaprasad

2005-10-25

422

Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys  

NASA Astrophysics Data System (ADS)

An integration of high-resolution non-destructive techniques is presented for the inspection and evaluation of ancient architectonic structures. Infrared thermography (IRT) represents a valuable tool for nondestructive evaluation of architectonic structures and artworks because it is capable of giving indications about most of the degradation sources of artworks and buildings of both historical interest and civil use. In particular, it is possible to detect cracks, disbondings, alteration of material consistency, etc. Indeed, by choosing the most adequate thermographic technique, it is possible to monitor the conservation state of artworks in time and to detect the presence of many types of defects (e.g., voids, cracks, disbondings, etc.) in different types of materials (e.g., concrete, masonry structures, bronze, etc.). The main advantages of infrared thermography when dealing with precious artworks may be summarized with three words: non-contact, non-invasive, and two-dimensionality. It is possible to inspect either a large surface such as the facade of a palace, or a very small surface of only few square millimetres. Conversely, the inspection depth is quite small; generally, of the order of centimetres. However, as demonstrated in previous work, IRT well matches with electric-and electromagnetic-type geophysical methods to characterize the overlapping zone from low-to-high depth in masonry structures. In particular, the use of high-frequency electromagnetic techniques, such as the ground penetrating radar (GPR), permits to reach investigation depths of some ten of centimetres by choosing appropriate frequencies of the transmitted electromagnetic signal. In the last decade a large utilisation of the GPR methodology to non-destructive analysis of engineering and architectural materials and structures has been experienced. This includes diverse features, such as definition of layer thickness, characterisation of different constructive materials, identification of voids and/or degraded zones, water content mapping, location of reinforcing bars and metal elements in concrete structures. The attention of this work is focused on the integration of both techniques for inspection of architectonic structures. First, an integration of techniques is performed in laboratory by considering an ad hoc specimen with insertion of anomalies. Then, the techniques are used for the inspection in situ of some important Italian archaeological sites, such as Pompei (Naples) and Nora (Cagliari). In the first site, the exploration is devoted to the analysis of wall decoration of the architectonical complex of Villa Imperiale with the aim to support the hypothesis that attributes the Villa to Imperial property as well as to evaluate the state of conservation of frescoes and underneath structure. As main findings, the applied techniques allows for detection of hidden previous decorative layers and for discrimination of different types of paint used as well as for identification of areas damaged by ingression in-depth of moisture and/or by disaggregation of the constituent materials. In the archaeological area of Nora, instead, the prospecting is devised to the evaluation of the state of degradation of two significant buildings of the ancient site: the temple and the theatre. Due to the very high horizontal and vertical resolution of the performed surveys, detailed physical anomaly maps of the investigated structures are obtained. Large portions of the masonry walls appear interested by decomposition of the mortar binding the stone blocks, which sometimes propagates along the whole stone wall. The information coming from a joint interpretation of IRT and GPR data allows detailed 3D images of the two investigated buildings, which are useful for future restoration planning.

di Maio, Rosa; Meola, Carosena; Fedi, Maurizio; Carlomagno, Giovanni Maria

2010-05-01

423

A survey on palette reordering methods for improving the compression of color-indexed images.  

PubMed

Palette reordering is a well-known and very effective approach for improving the compression of color-indexed images. In this paper, we provide a survey of palette reordering methods, and we give experimental results comparing the ability of seven of them in improving the compression efficiency of JPEG-LS and lossless JPEG 2000. We concluded that the pairwise merging heuristic proposed by Memon et al. is the most effective, but also the most computationally demanding. Moreover, we found that the second most effective method is a modified version of Zeng's reordering technique, which was 3%-5% worse than pairwise merging, but much faster. PMID:15540450

Pinho, Armando J; Neves, António J R

2004-11-01

424

Indications and organisational methods for autologous blood transfusion procedures in Italy: results of a national survey  

PubMed Central

Introduction Pre-operative donation of autologous blood is a practice that is now being abandoned. Alternative methods of transfusing autologous blood, other than predeposited blood, do however play a role in limiting the need for transfusion of allogeneic blood. This survey of autologous blood transfusion practices, promoted by the Italian Society of Transfusion Medicine and Immunohaematology more than 2 years after the publication of national recommendations on the subject, was intended to acquire information on the indications for predeposit in Italy and on some organisational aspects of the alternative techniques of autotransfusion. Materials and methods A structured questionnaire consisting of 22 questions on the indications and organisational methods of autologous blood transfusion was made available on a web platform from 15 January to 15 March, 2013. The 232 Transfusion Services in Italy were invited by e-mail to complete the online survey. Results Of the 232 transfusion structures contacted, 160 (69%) responded to the survey, with the response rate decreasing from the North towards the South and the Islands. The use of predeposit has decreased considerably in Italy and about 50% of the units collected are discarded because of lack of use. Alternative techniques (acute isovolaemic haemodilution and peri-operative blood salvage) are used at different frequencies across the country. Discussion The data collected in this survey can be considered representative of national practice; they show that the already very limited indications for predeposit autologous blood transfusion must be adhered to even more scrupulously, also to avoid the notable waste of resources due to unused units. Users of alternative autotransfusion techniques must be involved in order to gain a full picture of the degree of use of such techniques; multidisciplinary agreement on the indications for their use is essential in order for these indications to have an effective role in “patient blood management” programmes. PMID:25350961

Catalano, Liviana; Campolongo, Alessandra; Caponera, Maurizio; Berzuini, Alessandra; Bontadini, Andrea; Furlò, Giuseppe; Pasqualetti, Patrizio; Liumbruno, Giancarlo M.

2014-01-01

425

A ground electromagnetic survey used to map sulfides and acid sulfate ground waters at the abandoned Cabin Branch Mine, Prince William Forest Park, northern Virginia gold-pyrite belt  

USGS Publications Warehouse

INTRODUCTION AND BACKGROUND: Prince William Forest Park is situated at the northeastern end of the Virginia Gold-Pyrite belt northwest of the town of Dumfries, VA. The U. S. Marine Corps Reservation at Quantico borders the park on the west and south, and occupies part of the same watershed. Two abandoned mines are found within the park: the Cabin Branch pyrite mine, a historic source of acid mine drainage, and the Greenwood gold mine, a source of mercury contamination. Both are within the watershed of Quantico Creek (Fig.1). The Cabin Branch mine (also known as the Dumfries mine) lies about 2.4 km northwest of the town of Dumfries. It exploited a 300 meter-long, lens-shaped body of massive sulfide ore hosted by metamorphosed volcanic rocks; during its history over 200,000 tons of ore were extracted and processed locally. The site became part of the National Capitol Region of the National Park Service in 1940 and is currently managed by the National Park Service. In 1995 the National Park Service, in cooperation with the Virginia Department of Mines, Minerals, and Energy reclaimed the Cabin Branch site. The Virginia Gold-Pyrite belt, also known as the central Virginia volcanic-plutonic belt, is host to numerous abandoned metal mines (Pavlides and others, 1982), including the Cabin Branch deposit. The belt itself extends from its northern terminus near Cabin Branch, about 50 km south of Washington, D.C., approximately 175 km to the southwest into central Virginia. It is underlain by metamorphosed volcanic and clastic (non-carbonate) sedimentary rocks, originally deposited approximately 460 million years ago during the Ordovician Period (Horton and others, 1998). Three kinds of deposits are found in the belt: volcanic-associated massive sulfide deposits, low-sulfide quartz-gold vein deposits, and gold placer deposits. The massive sulfide deposits such as Cabin Branch were historically mined for their sulfur, copper, zinc, and lead contents, but also yielded byproduct gold and silver. The environmental impact of massive sulfide deposits can be substantial. These deposits are characterized by high concentrations of heavy-metal sulfide minerals, hosted by silicate rocks. Thus, weathering of these deposits and their mine wastes has the potential to generate heavy-metal laden sulfuric acid that can have negative impacts on aquatic ecosystems. In addition, lead associated with solid mine wastes has the potential for human health impacts through ingestion. The heavy metals that are encountered in these deposits and are most likely to cause environmental impacts include copper, zinc, lead, cadmium, and arsenic. In addition, the weathering of pyrite releases large amounts of iron, and the acid generated attacks the country rocks and causes the release of large amounts of aluminum, which also can severely impact aquatic ecosystems. A reclamation attempt was made at the site in 1995, including construction of storm-water diversion trenches around the abandoned mine area, grading tailings away from the stream bank, addition of pulverized limestone and topsoil, and revegetation. The post-reclamation chemistry of shallow groundwaters (<3 meters deep) shows a neutral pH on the southwestern bank of the stream but pH of 4.1 to 4.5 on the northeastern bank. The dominant ions are Fe2+ and SO42- (Seal, Haffner, Meier, and Pollio, 1999) A ground electromagnetic survey was conducted over the site in 1999 as part of a wider study ( Seal, Haffner, and Meier, 1998a,b, 1999). It was hoped that a 3-D map of the soil conductivity derived from the survey could provide insight into the distribution of the mobilized sulfides present under the ground. This study was conducted in cooperation with the National Park Service

Wynn, Jeffrey C.

2000-01-01

426

43 CFR Appendix I to Part 11 - Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the...  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the Preassessment...2): 6.9+3.5=10.4 acres. Surface Water The area of surface water resources potentially exposed...

2014-10-01

427

43 CFR Appendix I to Part 11 - Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the...  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the Preassessment...2): 6.9+3.5=10.4 acres. Surface Water The area of surface water resources potentially exposed...

2013-10-01

428

43 CFR Appendix I to Part 11 - Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the...  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the Preassessment...2): 6.9+3.5=10.4 acres. Surface Water The area of surface water resources potentially exposed...

2011-10-01

429

43 CFR Appendix I to Part 11 - Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the...  

Code of Federal Regulations, 2012 CFR

...2011-10-01 true Methods for Estimating the Areas of Ground Water and Surface Water Exposure During the Preassessment...2): 6.9+3.5=10.4 acres. Surface Water The area of surface water resources potentially exposed...

2012-10-01

430

Comparing the Cloud Vertical Structure Derived from Several Methods Based on Radiosonde Profiles and Ground-based Remote Sensing Measurements  

SciTech Connect

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, is an important characteristic in order to describe the impact of clouds in a changing climate. In this work several methods to estimate the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering number and position of cloud layers, with a ground based system which is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ on the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study these methods are applied to 125 radiosonde profiles acquired at the ARM Southern Great Plains site during all seasons of year 2009 and endorsed by GOES images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The overall agreement for the methods ranges between 44-88%; four methods produce total agreements around 85%. Further tests and improvements are applied on one of these methods. In addition, we attempt to make this method suitable for low resolution vertical profiles, which could be useful in atmospheric modeling. The total agreement, even when using low resolution profiles, can be improved up to 91% if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

Costa-Suros, M.; Calbo, J.; Gonzalez, J. A.; Long, Charles N.

2014-08-27

431

Wind load design methods for ground-based heliostats and parabolic dish collectors  

Microsoft Academic Search

The purpose of this design method is to define wind loads on flat heliostat and parabolic dish collectors in a simplified form. Wind loads are defined for both mean and peak loads accounting for the protective influence of upwind collectors, wind protective fences, or other wind-blockage elements. The method used to define wind loads was to generalize wind load data

J. A. Peterka; R. G. Derickson

1992-01-01

432

Taxometric AnalysisAn Empirically Grounded Approach to Implementing the Method  

Microsoft Academic Search

Whether individual differences are treated as categorical or continuous has consequences for theory, assessment, classification, and research in criminal justice. Paul Meehl's (1995) taxometric method allows investigators to test between these two competing structural models. This article provides an overview of the method's inferential framework and data-analytic procedures. Because guidelines for implementing taxometric analyses and interpreting their results have received

John Ruscio

2007-01-01

433

A generalized finite-difference formulation for the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model  

USGS Publications Warehouse

The U.S. Geological Survey's Modular Ground-Water Flow Model assumes that model nodes are in the center of cells and that transmissivity is constant within a cell. Based on these assumptions, the model calculates coefficients, called conductance, that are multiplied by head difference to determine flow between cells. Although these are common assumptions in finite-difference models, other assumptions are possible. A new option to the model program reads conductance as input data rather than calculating it. This optional lows the user to calculate conductance outside of the model. The user thus has the flexibility to define conductance using any desired assumptions. For a water-table condition, horizontal conductance must change as water level varies. To handle this situation, the new option reads conductance divided by thickness (CDT) as input data. The model calculates saturated thickness and multiplies it by CDT to obtain conductance. Thus, the user is still free from the assumptions of centered nodes and constant transmissivity in cells. The model option is written in FORTRAN77 and is fully compatible with the existing model. This report documents the new model option; it includes a description of the concepts, detailed input instructions, and a listing of the code.

Harbaugh, Arlen W.

1992-01-01

434

Comparison of ground-based measurements of natural radiation to airborne radiation survey data on transects from coastal California to the Colorado Plateau  

NASA Astrophysics Data System (ADS)

Natural gamma radiation measurements were collected with a hand-held Geiger counter at nearly 400 locations on two general transects across the southwestern United States. The data are used to provide ground-truth comparison to published airborne radiation surveys of the region. The first transect was collected by high school students in the SF-ROCKS program at San Francisco State University in the summer of 2008 starting in San Francisco. Data were collected across the Sierra Nevada Range on I-80, and across Highway 50 in Nevada, and I-70 in Utah. Data were collected in and around Great Basin, Arches, Capitol Reef, Bryce, and Zion National Parks, and Grand Staircase-Escalante National Monument. A second transect extends from San José, California to Flagstaff, Arizona and includes the Mojave National Reserve, Death Valley region, and locations throughout the Navajo Reservation region in northern Arizona and western New Mexico. Radiation data (with GPS reference) were collected from all the major sedimentary rock formations and igneous rocks of the Colorado Plateau and from many igneous and metamorphic rocks throughout the Great Basin and southern California deserts. Anomalously high localized levels were noted in selected sedimentary units associated with uranium exploration targets in the Colorado Plateau region, and in caverns and rock fissures where radon gas (and accumulation of derivative fission products) are the inferred sources.

Stoffer, P. W.; Hernández, L.; Messina, P.; Dearaujo, J.; Li, A.; Hicks, A.; White, L.

2008-12-01

435

A new method to improve photometric redshift reconstruction. Applications to the Large Synoptic Survey Telescope  

NASA Astrophysics Data System (ADS)

Context. In the next decade, the Large Synoptic Survey Telescope (LSST) will become a major facility for the astronomical community. However, accurately determining the redshifts of the observed galaxies without using spectroscopy is a major challenge. Aims: Reconstruction of the redshifts with high resolution and well-understood uncertainties is mandatory for many science goals, including the study of baryonic acoustic oscillations (BAO). We investigate different approaches to establish the accuracy that can be reached by the LSST six-band photometry. Methods: We construct a realistic mock galaxy catalog, based on the Great Observatories Origins Deep Survey (GOODS) luminosity function, by simulating the expected apparent magnitude distribution for the LSST. To reconstruct the photometric redshifts (photo-z's), we consider a template-fitting method and a neural network method. The photo-z reconstruction from both of these techniques is tested on real Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) data and also on simulated catalogs. We describe a new method to improve photometric redshift reconstruction that efficiently removes catastrophic outliers via a likelihood ratio statistical test. This test uses the posterior probability functions of the fit parameters and the colors. Results: We show that the photometric redshift accuracy will meet the stringent LSST requirements up to redshift ~2.5 after a selection that is based on the likelihood ratio test or on the apparent magnitude for galaxies with signal-to-noise ratio S/N > 5 in at least 5 bands. The former selection has the advantage of retaining roughly 35% more galaxies for a similar photo-z performance compared to the latter. Photo-z reconstruction using a neural network algorithm is also described. In addition, we utilize the CFHTLS spectro-photometric catalog to outline the possibility of combining the neural network and template-fitting methods. Conclusions: We demonstrate that the photometric redshifts will be accurately estimated with the LSST if a Bayesian prior probability and a calibration sample are used.

Gorecki, Alexia; Abate, Alexandra; Ansari, Réza; Barrau, Aurélien; Baumont, Sylvain; Moniez, Marc; Ricol, Jean-Stéphane

2014-01-01

436

Compilation of ground-water level measurements, obtained by the United States Geological Survey in Puerto Rico, 1958-1985  

USGS Publications Warehouse

A digital compilation of the groundwater levels in Puerto Rico was prepared as part of the Caribbean Islands Regional Aquifers System Analysis program. Of special interest are the groundwater levels measurements obtained on a routine basis at wells located in the different aquifer regions or aquifer zones. Data from 181 observation wells were entered in the computer data base. The data base includes the following: name, latitude and longitude coordinates, owner, diameter, depth, station identification, local number, aquifer area or region, period of record, construction date, earliest groundwater level reported, and groundwater level fluctuations for various time periods between 1958 and 1985. Data showing conditions under which groundwater level measurements may have been affected by (1) pumping of the well, (2) by a nearby pumping well (3) a specific method by which the groundwater level was determined, (4) whether the well was recently pumped, and (5) when recorded, the lowest water level are also indicated. The summarized information is available in printed format on a yearly basis as part of the Water Resources Data Publication series. (USGS)

Torres-Gonzalez, Sigfredo

1991-01-01

437

Application of classification-tree methods to identify nitrate sources in ground water  

USGS Publications Warehouse

A study was conducted to determine if nitrate sources in ground water (fertilizer on crops, fertilizer on golf courses, irrigation spray from hog (Sus scrofa) wastes, and leachate from poultry litter and septic systems) could be classified with 80% or greater success. Two statistical classification-tree models were devised from 48 water samples containing nitrate from five source categories. Model I was constructed by evaluating 32 variables and selecting four primary predictor variables (??15N, nitrate to ammonia ratio, sodium to potassium ratio, and zinc) to identify nitrate sources. A ??15N value of nitrate plus potassium 18.2 indicated inorganic or soil organic N. A nitrate to ammonia ratio 575 indicated nitrate from golf courses. A sodium to potassium ratio 3.2 indicated spray or poultry wastes. A value for zinc 2.8 indicated poultry wastes. Model 2 was devised by using all variables except ??15N. This model also included four variables (sodium plus potassium, nitrate to ammonia ratio, calcium to magnesium ratio, and sodium to potassium ratio) to distinguish categories. Both models were able to distinguish all five source categories with better than 80% overall success and with 71 to 100% success in individual categories using the learning samples. Seventeen water samples that were not used in model development were tested using Model 2 for three categories, and all were correctly classified. Classification-tree models show great potential in identifying sources of contamination and variables important in the source-identification process.

Spruill, T.B.; Showers, W.J.; Howe, S.S.

2002-01-01

438

A method for monitoring ground water quality near waste storage facilities.  

PubMed

A practical optimization approach developed in this paper derives effective monitoring configurations for detecting contaminants in ground water. The approach integrates numerical simulation of contaminant transport and mathematical programming. Well sites identified by the methodology can be monitored to establish the occurrence of a contaminant release before a plume migrates to a regulatory compliance boundary. Monitoring sites are established along several horizons located between the downgradient margin of a contaminant source and a compliance boundary. A horizon can form an effective line of defense against contaminant migration to the compliance boundary if it is spanned (covered) by a sufficient number of sites to yield a well spacing that is equal to or less than a maximum value established by numerical modeling. The objective function of the integer programming model formulation expresses the goals of: (1) covering a maximum number of siting horizons, and (2) allocating wells to the single most effective horizon. The latter is determined from well spacing requirements and the width of the zone of potential contaminant migration traversed by the horizon. The methodology employs a highly tractable linear programming model formulation, and the user is not required to predefine a set of potential well sites. These attributes can facilitate its implementation in practice. PMID:24213746

Hudak, P F

1994-04-01

439

Automatic Vehicle Location (avl) and Road Survey With Placer/dr GPS Method  

NASA Astrophysics Data System (ADS)

Pisa University belongs to the National Research Projects lead by Prof. George Manzoni of Trieste University. Pisa University has completed the preparation of its own cross-country motor vehicle (Fiat Panda 4x4 van) with a new low-cost navigational GPS + Inertial Navigation System (odometer and gyroscope). The searching activity carried out now is aimed to survey road axis in zones with numeric cartography, to record GPS+INS data and to study reability and precision of the system in urban and extra-urban environment. The results of the first road surveys in urban environment are good and they are showed by a commercial GIS, with a vectorial map and it is possible to see where the system recorded with GPS 2D-3D method or with INS method. The research program foresees the integration of the vehicle position data with those coming from: - specific environmental sensors (e.g. atmospheric pollution sensors, electromagnetics sensors ... - other topographical instrumentations (e.g. laser scanners, ..) - georeferenced images acquired with cameras and/or television cameras set on the vehicle, but also with those from high definition satellite images. The data acquired by the vehicle in a first time will be elaborated through post- processing, and only after the testing of the instrumentations and the checking of their well-operation, the survey will be experimented in real time.

Caroti, G.

440

Statistical Methods for Detecting Stellar Occultations by Kuiper Belt Objects: the Taiwanese-American Occultation Survey  

E-print Network

The Taiwanese-American Occultation Survey (TAOS) will detect objects in the Kuiper Belt, by measuring the rate of occultations of stars by these objects, using an array of three to four 50cm wide-field robotic telescopes. Thousands of stars will be monitored, resulting in hundreds of millions of photometric measurements per night. To optimize the success of TAOS, we have investigated various methods of gathering and processing the data and developed statistical methods for detecting occultations. In this paper we discuss these methods. The resulting estimated detection efficiencies will be used to guide the choice of various operational parameters determining the mode of actual observation when the telescopes come on line and begin routine observations. In particular we show how real-time detection algorithms may be constructed, taking advantage of having multiple telescopes. We also discuss a retrospective method for estimating the rate at which occultations occur.

Chyng-Lan Liang; John A. Rice; Imke de Pater; Charles Alcock; Tim Axelrod; Andrew Wang

2002-09-24