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1

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

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.

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

1991-06-18

3

Method of locating ground faults  

NASA Technical Reports Server (NTRS)

The present invention discloses a method of detecting and locating current imbalances such as ground faults in multiwire systems using the Faraday effect. As an example, for 2-wire or 3-wire (1 ground wire) electrical systems, light is transmitted along an optical path which is exposed to magnetic fields produced by currents flowing in the hot and neutral wires. The rotations produced by these two magnetic fields cancel each other, therefore light on the optical path does not read the effect of either. However, when a ground fault occurs, the optical path is exposed to a net Faraday effect rotation due to the current imbalance thereby exposing the ground fault.

Patterson, Richard L. (inventor); Rose, Allen H. (inventor); Cull, Ronald C. (inventor)

1994-01-01

4

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

5

Grounded electrical-source airborne transient electromagnetic (GREATEM) survey of Mount Bandai, north-eastern Japan  

Microsoft Academic Search

Airborne electromagnetics (AEM) is a useful tool for investigating volcanic structures because it can survey large and inaccessible areas. Disadvantages include lower accuracy and limited depth of investigation. The Grounded Electrical Source Airborne Transient Electromagnetic (GREATEM) survey system was developed to increase the depth of investigation possible using AEM. The method was tested in a survey at Mount Bandai in

Toru Mogi; Ken'ichirou Kusunoki; Hideshi Kaieda; Hisatoshi Ito; Akira Jomori; Nobuhide Jomori; Youichi Yuuki

2009-01-01

6

Concerning Underwater Remote Sensing Surveys, Anomalies, and Ground Truthing.  

National Technical Information Service (NTIS)

The purpose of the paper is to briefly discuss and compare marine remote sensing surveys conducted for research purposes with those conducted for cultural resource management purposes. Examples of anomalies from Texas waters that have been ground truthed ...

J. B. Arnold

1980-01-01

7

Investigations into near-real-time surveying for geophysical data collection using an autonomous ground vehicle  

USGS Publications Warehouse

The U.S. Geological Survey and the National Aeronautics and Space Administration are cooperatively investigating the utility of unmanned vehicles for near-real-time autonomous surveys of geophysical data collection. Initially focused on unmanned ground vehicle collection of magnetic data, this cooperative effort has brought unmanned surveying, precision guidance, near-real-time communication, on-the-fly data processing, and near-real-time data interpretation into the realm of ground geophysical surveying, all of which offer advantages over current methods of manned collection of ground magnetic data. An unmanned ground vehicle mission has demonstrated that these vehicles can successfully complete missions to collect geophysical data, and add advantages in data collection, processing, and interpretation. We view the current experiment as an initial phase in further unmanned vehicle data-collection missions, including aerial surveying.

Phelps, Geoffrey; Ippolito, C.; Lee, R.; Spritzer, R.; Yeh, Y.

2014-01-01

8

Ground-Cover Measurements: Assessing Correlation Among Aerial and Ground-Based Methods  

NASA Astrophysics Data System (ADS)

Wyoming’s Green Mountain Common Allotment is public land providing livestock forage, wildlife habitat, and unfenced solitude, amid other ecological services. It is also the center of ongoing debate over USDI Bureau of Land Management’s (BLM) adjudication of land uses. Monitoring resource use is a BLM responsibility, but conventional monitoring is inadequate for the vast areas encompassed in this and other public-land units. New monitoring methods are needed that will reduce monitoring costs. An understanding of data-set relationships among old and new methods is also needed. This study compared two conventional methods with two remote sensing methods using images captured from two meters and 100 meters above ground level from a camera stand (a ground, image-based method) and a light airplane (an aerial, image-based method). Image analysis used SamplePoint or VegMeasure software. Aerial methods allowed for increased sampling intensity at low cost relative to the time and travel required by ground methods. Costs to acquire the aerial imagery and measure ground cover on 162 aerial samples representing 9000 ha were less than 3000. The four highest correlations among data sets for bare ground—the ground-cover characteristic yielding the highest correlations (r)—ranged from 0.76 to 0.85 and included ground with ground, ground with aerial, and aerial with aerial data-set associations. We conclude that our aerial surveys are a cost-effective monitoring method, that ground with aerial data-set correlations can be equal to, or greater than those among ground-based data sets, and that bare ground should continue to be investigated and tested for use as a key indicator of rangeland health.

Booth, D. Terrance; Cox, Samuel E.; Meikle, Tim; Zuuring, Hans R.

2008-12-01

9

30 CFR 77.700-1 - Approved methods of grounding.  

Code of Federal Regulations, 2013 CFR

...Approved methods of grounding. Metallic...resistance grounded systems, where the...in all other systems, the following methods of grounding will be approved...connection to a grounding conductor...resistance grounded system,...

2013-07-01

10

30 CFR 75.700-1 - Approved methods of grounding.  

Code of Federal Regulations, 2013 CFR

...Approved methods of grounding. Metallic...resistance grounded systems where the enclosed...in all other systems, the following methods of grounding will be approved...connection to a grounding conductor...resistance grounded system,...

2013-07-01

11

GROUND AND AIRBORNE ELECTROMAGNETIC METHODS  

Microsoft Academic Search

1. SUMMARY Electromagnetic (EM) methods are used to map variations in electrical properties. The main physical property involved in these methods is inductive electrical conductivity, which is a measure of how easily electrical current can pass through a material. Conductivity is a complex function of several variables including the conductivity of solid materials, conductivity of pore fluids, porosity, arrangement of

12

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

13

Survey of ground antenna systems for solar power satellite application  

NASA Astrophysics Data System (ADS)

The purpose of this work is to survey ground based antenna systems, specifically rectifying antennas (rectennas) for space solar powered application of Microwave Wireless Power Transfer (MWPT). The ground rectenna along with its circuit components (a receiving antenna, an input Low-Pass Filter (LPF), a rectifying circuit, and an output smoothing filter) is the basic building block of the high-power receiving array that is designed to capture and then convert the microwave energy into Direct Current (DC). Once in DC form, the energy is used for various human applications on earth.

Bergsrud, Corey; Noghanian, Sima

14

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

15

Grounded Theory Methods and Qualitative Family Research  

ERIC Educational Resources Information Center

Among the different qualitative approaches that may be relied upon in family theorizing, grounded theory methods (GTM), developed by Barney Glaser and Anselm Strauss, are the most popular. Despite their centrality to family studies and to other fields, however, GTM can be opaque and confusing. Believing that simplifying GTM would allow them to be…

LaRossa, Ralph

2005-01-01

16

Solar Flare Impulse Broadening from 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 unintended gamma radiation along transport routes. Signals from pedestrian borne and vehicle borne radiation sources have pulse widths that range three orders of magnitude in time from millseconds to seconds. Information collected during the 24/7 operation of this network generated unexpected signals lasting over an hour. These longer time responses have been traced to solar flare events. This paper will discuss the time and intensity correlations with known satellite sensor data. These terrestrial gamma ray flashes will be analysed further as real-time data continues to be collected.

Litz, Marc; Burns, David; Carroll, James; Pereira, Nino

2012-03-01

17

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

18

Grounded electrical-source airborne transient electromagnetics (GREATEM) survey of Aso Volcano, Japan  

NASA Astrophysics Data System (ADS)

Grounded electrical-source airborne transient electromagnetics (GREATEM), a type of semi-airborne electromagnetics, was used to examine Aso Volcano in south-west Japan, to verify its applicability to surveying deep subsurface resistivity structures. Comparison of the GREATEM resistivity values with those of ground-based transient electromagnetics (TEM) data, repeated GREATEM survey results at the same and different flight heights, and lithologic descriptions indicated that GREATEM can successfully identify underground structures as deep as ~800 m in rugged mountainous areas. An active volcanic region (Naka-Dake crater) was mapped as a low-resistivity zone from the surface to a depth of 100 m. This low-resistivity zone extended to the west-north-west, implying future volcanic activity in this area. Therefore, the GREATEM method is useful for surveying deep structures in large, inaccessible areas, such as volcanic provinces, in a quick, cost-effective way.

Ito, Hisatoshi; Kaieda, Hideshi; Mogi, Toru; Jomori, Akira; Yuuki, Youichi

2014-05-01

19

Comparison of Satellite Surveying to Traditional Surveying Methods for the Resources Industry  

NASA Astrophysics Data System (ADS)

Modern ground-based survey methods involve detailed survey, which provides three-space co-ordinates for surveyed points, to a high level of accuracy. The instruments are operated by surveyors, who process the raw results to create survey location maps for the subject of the survey. Such surveys are conducted for a location or region and referenced to the earth global co- ordinate system with global positioning system (GPS) positioning. Due to this referencing the survey is only as accurate as the GPS reference system. Satellite survey remote sensing utilise satellite imagery which have been processed using commercial geographic information system software. Three-space co-ordinate maps are generated, with an accuracy determined by the datum position accuracy and optical resolution of the satellite platform.This paper presents a case study, which compares topographic surveying undertaken by traditional survey methods with satellite surveying, for the same location. The purpose of this study is to assess the viability of satellite remote sensing for surveying in the resources industry. The case study involves a topographic survey of a dune field for a prospective mining project area in Pakistan. This site has been surveyed using modern surveying techniques and the results are compared to a satellite survey performed on the same area.Analysis of the results from traditional survey and from the satellite survey involved a comparison of the derived spatial co- ordinates from each method. In addition, comparisons have been made of costs and turnaround time for both methods.The results of this application of remote sensing is of particular interest for survey in areas with remote and extreme environments, weather extremes, political unrest, poor travel links, which are commonly associated with mining projects. Such areas frequently suffer language barriers, poor onsite technical support and resources.

Osborne, B. P.; Osborne, V. J.; Kruger, M. L.

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

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

22

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

23

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

24

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

25

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

26

Innovations in Travel Survey Methods.  

National Technical Information Service (NTIS)

The papers in this volume present a variety of innovative techniques to monitor, collect, and disseminate travel survey information. Several papers focus on techniques of collecting travel information, such as travel diaries, origin-destination surveys of...

1993-01-01

27

Eighth Conference on Health Survey Research Methods.  

National Technical Information Service (NTIS)

The purpose of this conference was to continue a series of conferences on health survey research methods that began in 1975, bringing together researchers from academic disciplines who conduct and use data from surveys, researchers and administrators from...

T. P. Johnson D. O'Rourke

2004-01-01

28

National Eutrophication Survey Methods 1973-1976.  

National Technical Information Service (NTIS)

Chemical, physical, and biological methods and other procedures used by the U.S. Environmental Protection Agency's National Eutrophication Survey are detailed. These procedures were used during the last three years of the Survey in lake, stream, and munic...

1975-01-01

29

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

30

Gravity and ground magnetic surveys of the Thermo Hot Springs KGRA region, Beaver County, Utah  

Microsoft Academic Search

During the period June to September 1976, gravity and ground magnetic surveys were made in the Thermo Hot Springs KGRA region which is located southwest of the town of Milford, Beaver County, Utah. The regional surveys comprised 273 new gravity and magnetic stations and incorporated 104 previous gravity stations over an area of approximately 620 km². The detailed surveys consisted

Robert F. Sawyer; Kenneth L. Cook

1977-01-01

31

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

32

Grounded electrical-source airborne transient electromagnetic (GREATEM) survey of Mount Bandai, north-eastern Japan  

NASA Astrophysics Data System (ADS)

Airborne electromagnetics (AEM) is a useful tool for investigating volcanic structures because it can survey large and inaccessible areas. Disadvantages include lower accuracy and limited depth of investigation. The Grounded Electrical Source Airborne Transient Electromagnetic (GREATEM) survey system was developed to increase the depth of investigation possible using AEM. The method was tested in a survey at Mount Bandai in north-eastern Japan. Mount Bandai is an andesitic stratovolcano that rises 1819m above sea level. An eruption in July 1888 left a hoof-shaped collapsed wall in its northern crater and avalanche debris at its base. Previous surveys of Mount Bandai allow for comparisons of data on its structure and collapse mechanism as obtained by GREATEM and other geophysical methods. The results show resistive structures in recent volcanic cones and conductive structures in the collapsed-crater area. Conductive areas around the collapsed wall correspond to an alteration zone resulting from hydrothermal activity, supporting the contention that a major cause of the collapse associated with the 1888 eruption was hydrothermal alteration that structurally weakened the interior of the volcanic edifice.

Mogi, Toru; Kusunoki, Ken'ichirou; Kaieda, Hideshi; Ito, Hisatoshi; Jomori, Akira; Jomori, Nobuhide; Yuuki, Youichi

2009-02-01

33

NCES Handbook of Survey Methods.  

National Technical Information Service (NTIS)

This publication presents explanations of how each survey program in NCES obtains and prepares the data it publishes. The Handbook aims to provide users of NCES data with the information necessary to evaluate the suitability of the statistics for their ne...

2011-01-01

34

Improved Ground Vibration Test Method. Volume I. Research Report.  

National Technical Information Service (NTIS)

Research was conducted to develop an improved method for ground vibration testing of airplanes. The resulting method, a single point excitation-frequency response analysis method, utilizes the computer, modern electronic equipment, developments in vibrati...

C. S. Doherty D. L. Brown D. W. Gimmestad R. F. Michalak R. J. Allemang

1980-01-01

35

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

36

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

37

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

38

Research opportunities in interdisciplinary ground-water science in the U.S. Geological Survey  

USGS Publications Warehouse

This report is written for the scientifically literate reader but is not limited to those who are involved in ground-water science. The report is intended to encourage U.S. Geological Survey scientists to develop a sense of excitement about ground-water science in the agency, to inform scientists about existing and potential ground-water science opportunities, and to engage scientists and managers in interdisciplinary discussions and collaboration. The report is intended for use by U.S. Geological Survey and Department of the Interior management to formulate long-term ground-water science programs and to continue sustained support of ground-water monitoring and research, some of which may not have an immediate impact. Finally, the report can be used to communicate the U.S. Geological Survey's vision of ground-water science to Congress, partners, other agencies, and the research community at large with the goals of enhancing collaborative opportunities, sharing information, and maintaining dialogue regarding the directions of U.S. Geological Survey ground-water science.

Sanford, W. E.; Caine, J. S.; Wilcox, D. A.; McWreath, H. C.; Nicholas, J. R.

2006-01-01

39

Traditional Ground Stroke Versus Volley Method of Teaching Beginning Tennis  

ERIC Educational Resources Information Center

A study of college women in beginning tennis classes indicated that students instructed by the volley method of teaching tennis improved significantly over those instructed by the ground stroke method, particularly in their forehand drives. (JD)

Burrus-Bammel, Lei Lane

1976-01-01

40

The Archeological Survey: Methods and Uses.  

National Technical Information Service (NTIS)

The publication, written in plain language primarily for the non-archeologist, presents the methods and objectives of archeological survey. It begins with a description of the formation of the archeological record and describes how this record has been di...

T. F. King

1978-01-01

41

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

42

Triangulation of Qualitative Methods: Heideggerian Hermeneutics and Grounded Theory.  

ERIC Educational Resources Information Center

Proposes the triangulation of two qualitative research methods, hermeneutics and grounded theory, to illuminate clinical realities that elude alternative approaches. Discusses how hermeneutics reveals perceptual information about the uniqueness of shared meanings and common practices, and how grounded theory provides a conceptual framework useful…

Wilson, Holly Skodol; Hutchinson, Sally A.

1991-01-01

43

GWM: A Ground-Water Management Process for the U.S. Geological Survey Modular Ground-Water Model (MODFLOW-2000).  

National Technical Information Service (NTIS)

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 manag...

D. P. Ahlfeld P. M. Barlow A. E. Mulligan

2005-01-01

44

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

45

Trachoma survey methods: a literature review  

PubMed Central

Abstract Reliable population-based prevalence data are essential for planning, monitoring and evaluating trachoma control programmes and understanding the scale of the problem, yet they are not currently available for 22 out of 56 trachoma-endemic countries. Three survey methods have been advocated for trachoma: cluster random sampling (CRS); trachoma rapid assessment (TRA); and acceptance sampling trachoma rapid assessment (ASTRA). Our review highlights the benefits of CRS being simple, efficient, repeatable and giving population-based prevalence estimates of all signs of trachoma. There are limitations to TRA, which include: non-representative sampling; does not estimate prevalence; and lacks consistency and accuracy. ASTRA advocates small sample sizes but it is relatively complex, may result in imprecise prevalence estimates and does not estimate cicatricial signs of trachoma. We conclude that CRS should therefore remain the “gold” standard for trachoma surveys. However, among the CRS surveys reviewed, we also found several methodological deficiencies of sample-size calculations, standardization of trachoma graders, reporting of confidence intervals of prevalence estimates, variability of age groups for presentation of age-specific prevalence, and lack of estimation of district prevalence estimates. Properly conducted surveys will be crucial if the objective of global elimination of blinding trachoma is to be charted and realized. Harmonization of survey methods will enhance the conduct and comparability of trachoma surveys needed for reliable mapping of prevalence within endemic countries. Consistent with WHO recommendations, we advocate for continued use of CRS as the survey design of choice for trachoma control programmes and propose ways of improving future surveys based on this method.

Reacher, Mark; Matthews, Fiona; Brayne, Carol; Emerson, Paul

2009-01-01

46

Population trends from the American woodcock singing-ground survey, 1970-88  

USGS Publications Warehouse

Population trend analysis of American woodcook (Scolopax minor) using data from a singing-ground survey indicates population declines throughout the breeding range of the species between 1970 and 1988. In the eastern United States and Canada, this decline has been quite consistent throughout the period, but in the central portion of the continent the population increased during the 1970's and declined during the early 1980's. Observers differ in their ability to hear woodcock, and we document observer differences in the singing-ground survey data and incorporate them into our analyses. Habitat changes have been suggested as the most likely cause of declines in woodcock populations.

Sauer, J.R.; Bortner, J.B.

1991-01-01

47

Geomagnetic ground survey in Slovakia for the 2007.5 epoch  

Microsoft Academic Search

New geomagnetic ground survey was carried out in years 2006-2008. The survey was accomplished under fair geomagnetic-activity conditions during the minimum phase of a solar activity cycle No. 23. The measurements of the geomagnetic field were reduced to the 2007.5 epoch using magnetograms of the Hurbanovo Geomagnetic Obser- vatory. The distribution of the geomagnetic field over the territory of Slovakia

Peter DOLINSK ´; Fridrich VALACH

2009-01-01

48

Improvements to the DRASTIC ground-water vulnerability mapping method  

USGS Publications Warehouse

Ground-water vulnerability maps are designed to show areas of greatest potential for ground-water contamination on the basis of hydrogeologic and anthropogenic (human) factors. The maps are developed by using computer mapping hardware and software called a geographic information system (GIS) to combine data layers such as land use, soils, and depth to water. Usually, ground-water vulnerability is determined by assigning point ratings to the individual data layers and then adding the point ratings together when those layers are combined into a vulnerability map. Probably the most widely used ground-water vulnerability mapping method is DRASTIC, named for the seven factors considered in the method: Depth to water, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone media, and hydraulic Conductivity of the aquifer (Aller and others, 1985, p. iv). The DRASTIC method has been used to develop ground-water vulnerability maps in many parts of the Nation; however, the effectiveness of the method has met with mixed success (Koterba and others, 1993, p. 513; U.S. Environmental Protection Agency, 1993; Barbash and Resek, 1996; Rupert, 1997). DRASTIC maps usually are not calibrated to measured contaminant concentrations. The DRASTIC ground-water vulnerability mapping method was improved by calibrating the point rating scheme to measured nitrite plus nitrate as nitrogen (NO2+NO3–N) concentrations in ground water on the basis of statistical correlations between NO2+NO3–N concentrations and land use, soils, and depth to water (Rupert, 1997). This report describes the calibration method developed by Rupert and summarizes the improvements in results of this method over those of the uncalibrated DRASTIC method applied by Rupert and others (1991) in the eastern Snake River Plain, Idaho.

Rupert, Michael G.

1999-01-01

49

Survey on liver CT image segmentation methods  

Microsoft Academic Search

The segmentation of liver using computed tomography (CT) data has gained a lot of importance in the medical image processing\\u000a field. In this paper, we present a survey on liver segmentation methods and techniques using CT images, recent methods presented\\u000a in the literature to obtain liver segmentation are viewed. Generally, liver segmentation methods are divided into two main\\u000a classes, semi-automatic

Ahmed M. Mharib; Abdul Rahman Ramli; Syamsiah Mashohor; Rozi Binti Mahmood

50

Ground-penetrating radar and electromagnetic surveys at the Monroe Crossroads battlefield site, Fort Bragg, North Carolina  

USGS Publications Warehouse

A ground-penetrating radar survey was conducted at the Monroe Crossroads Battlefield site at Fort Bragg, North Carolina, to determine possible locations of subsurface archaeological features. An electromagnetic survey also was conducted at the site to verify and augment the ground-penetrating radar data. The surveys were conducted over a 67,200-square-foot grid with a grid point spacing of 20 feet. During the ground-penetrating radar survey, 87 subsurface anomalies were detected based on visual inspection of the field records. These anomalies were flagged in the field as they appeared on the ground-penetrating radar records and were located by a land survey. The electromagnetic survey produced two significant readings at ground-penetrating radar anomaly locations. The National Park Service excavated 44 of the 87 anomaly locations at the Civil War battlefield site. Four of these excavations produced significant archaeological features, including one at an abandoned well.

Kessler, Richard; Strain, R. E.; Marlowe, J. I., II; Currin, K. B.

1996-01-01

51

THE CHANGING NATURE OF SURVEYING INFRASTRUCTURE FROM MARKS IN THE GROUND TO VIRTUAL REFERENCE STATIONS  

Microsoft Academic Search

Surveying infrastructure has always relied on networks of marks in the ground. However, that approach is increasingly giving way to permanently running GPS base stations making data available for real time positioning or for Internet based post processing. The first part of this paper outlines the results of a pilot network established over South East Queensland to investigate the Virtual

Matthew B HIGGINS

52

Ground-based thermal infrared surveys of Mount Rainier volcano, Washington  

Microsoft Academic Search

Detailed, ground-based thermal surveys of selected slopes of Mount Rainier, Washington, utilizing a Barnes PRT-5 Radiation Thermometer have provided quantitative data for the construction of thermal contour maps of portions of the upper flanks of this volcano. The thermal imagery, done in August, 1973, did not locate any suspect thermal areas on the northwest face of Little Tahoma Peak, the

I. M. Lange; J. C. Avent

1974-01-01

53

Helium and Ground Temperature Surveys at Steamboat Springs, Colorado  

Microsoft Academic Search

n, Steamboat Springs, olorado, he1 ium and shallow quick, inexpensive ge rmal-exploration methods that ogether with excellent r esults. Steamboat Springs, in ado, lies primarily upon terrace gravels and alluvium with the major structure being a north-trending normal fault passing through the western portion of the city. Work by Christopherson (1979) indicates that the Steamboat warm springs are not laterally

Kevin P. McCarthy; Josh Been; G. M. Reimer; C. Gilbert Bowles; D. G. Murrey

54

A Survey of Methods and Materials.  

ERIC Educational Resources Information Center

Designed to assess and describe the nature and frequency of teaching methods, activities, and materials used in secondary school English courses, this survey consists of 14 questions related to teaching objectives, activities, and materials, each followed by a list of possible responses. Teachers are asked to select a course, and to circle for…

Gillis, Candida; And Others

55

Survey of Electronic Payment Methods and Systems.  

National Technical Information Service (NTIS)

In this paper an overview of electronic payment methods and systems is given. This survey is done as part of the Moby Dick project: a joint european project (Esprit Long Term Research 20422) to develop and define the architecture of a new generation of mo...

P. J. M. Havinga G. J. M. Smit A. Helme

1996-01-01

56

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

57

Aerial radiological survey of the Paducah Gaseous Diffusion Plant, Paducah, Kentucky. Date of aerial survey: August 1976. Date of ground survey: May 1977  

Microsoft Academic Search

An airborne radiological survey of a 57 km² area surrounding the Paducah Gaseous Diffusion Plant (PGDP) site was made during August 1976. Detected radioisotopes, and their associated gamma ray exposure rates, were consistent with those expected from normal background emitters, except at certain locations. Average exposure rates 1 m above the ground, as calculated from the aerial data, are presented

Hilton

1978-01-01

58

New method for lightning location using optical ground wire  

Microsoft Academic Search

A new technology of lightning location is described, which is based on detecting the state of polarization (SOP) fluctuation of the laser light in the optic ground wire (OPGW). Compared with the conventional lightning location method, the new method is more accurate, more stable, and cheaper. Theories of Stokes parameters and Poincare sphere are introduced to analyze the SOP at

Zhaoyu Qin; Zhaogu Cheng; Zhiping Zhang; Jianqiang Zhu; Feng Li

2006-01-01

59

Biomass Estimation by ALOS/PALSAR over Boreal Forest in Alaska Accompanied with Ground-based Forest Survey  

NASA Astrophysics Data System (ADS)

For the better understanding of the carbon cycle in the global ecosystem, investigations on the spatio- temporal variation of the carbon stock which is stored as vegetation biomass is important. The sensor "PALSAR (Phased Array type L-band Synthetic Aperture Radar)" of the satellite "ALOS (Advanced Land Observing Satellite)", launched in January 2006, provides the information which can be used for the above- ground biomass estimation. To derive the forest biomass from satellite measurement, it is inevitable to acquire in situ above-ground biomass by ground-based survey. In July 2007, a forest survey was carried out in the south-north transect (about 300km long) along the Trans-Alaska Pipeline which profiles the ecotone from boreal forest to tundra in Alaska. 29 forests along the transect were targeted for the survey, and their biomasses were measured by the combination method of Bitterlich Angle Count Sampling method and Sampled-tree Measuring method. Consequently, it was revealed that the forest biomass distributes from 5 to 100 ton/ha (dried matter). These ground-based biomass measurements at 29 forests were compared with the signal in 20 mages of ALOS/PALSAR (HV polarization mode) that cover the 29 forests in July or August 2007. In addition, 16 areas of grassland in the images were picked for the reference value of zero forest biomass. The result showed a positive strong (r = 0.84) and linear relationship between them, demonstrating a feasibility of ALOS/PALSAR for the mapping of the biomass in boreal forests.

Suzuki, R.; Kim, Y.; Ishii, R.

2008-12-01

60

Status of ground-water modeling in the U.S. Geological Survey  

USGS Publications Warehouse

The U.S. Geological Survey is active in the development and use of models for the analysis of various types of ground-water problems. Types of problems for which models have been, or are being, developed include: (1) ground-water flow in saturated or partially unsaturated materials, (2) land subsidence resulting from ground-water extraction, (3) flow in coupled ground water-stream systems, (4) coupling of rainfall-runoff basin models with soil moisture accounting and aquifer flow models, (5) interaction of economic and hydrologic considerations, (6) predicting the transport of contaminants in an aquifer, and (7) estimating the effects of proposed development schemes for geothermal systems. The status of modeling activity for various models is reported as being in a developmental, verification, operational, or continued improvement phase. Recently published references that provide useful details on the characteristics of the models are identified. (Woodard-USGS)

Appel, Charles A.; Bredehoeft, J. D.

1976-01-01

61

Ground penetrating radar results at the Box Canyon Site - 1996 survey as part of infiltration test  

SciTech Connect

This data report presents a discussion of the borehole radar tomography experiment conducted at Box Canyon, Idaho. Discussion concentrates on the survey methodology, data acquisition procedures, and the resulting tomographic images and interpretations. The entire geophysics field effort for FY96 centered around the collection of the borehole radar data within the inclined boreholes R1, R2, R3, and R4 before, during, and after the ponded infiltration experiment. The well pairs R1-R2, R2-R4, and R3-R4 comprised the bulk of the field survey; however, additional data were collected between vertical boreholes within and around the infiltration basin. The intent of the inclined boreholes was to allow access beneath the infiltration basin and to enhance the ability of the radar method to image both vertical and horizontal features where flow may dominate. This data report will concentrate on the inclined borehole data and the resulting tomograms. The borehole radar method is one in which modified ground penetrating radar antennas are lowered into boreholes and high frequency electromagnetic signals are transmitted through subsurface material to a receiving antenna. The transmitted signals may be represented as multiple raypaths crossing through the zone of interest. If sufficient raypaths are recorded, a tomographic image may be obtained through computer processing. The data normally recorded are signal amplitude versus time. The information extracted from such data includes the following: (a) the transit time which depends on the wave velocity, (b) the amplitude which depends on the wave attenuation, the dispersion which indicates a change in velocity and attenuation with frequency.

Peterson, J.E. Jr.; Williams, K.H.

1997-08-01

62

Diminution of terrestrial gamma ray exposure rate due to snow cover. Ground survey and aerial survey.  

National Technical Information Service (NTIS)

In order to clarify the diminution characteristics of terrestrial gamma ray exposure rate due to snow cover, measurements were performed on the ground with and without snow cover. Aerial measurement was also performed above the snow cover in order to obta...

T. Nagaoka R. Sakamoto K. Saito M. Tsutsumi S. Moriuchi

1991-01-01

63

Integrated resistivity surveys for delineation of fractures for ground water exploration in hard rock areas  

NASA Astrophysics Data System (ADS)

Acute shortage of ground water in hard rock areas is well known. Ground water occurs in limited areal extent in secondary porosity generally developed due to weathering, fracturing, jointing, faulting etc. within the hard rock formations. These structural changes (fractures etc.) are sparsely distributed in the hard rock areas. Gradient profiling followed by geoelectrical sounding has been successfully utilized to delineate fractures saturated with water in hard rock areas of Gurudev Nagar, Mirzapur District, India. To begin with, the Gradient profiling (GP) survey was conducted along nine profiles with fixed current electrodes separation of 600 m and different potential electrodes separations for all the points lying between central region of the profile (about 33% of the total spread) at a station interval of 5 m. Eventually a comparative study of Wenner profiling and Gradient profiling along a specific profile line exhibits superiority of later over former. Based on the analyses of the response of GP survey, eleven prominent 'low' resistive points were selected. Geoelectrical sounding (GS) survey was then carried out at these locations. The interpreted sounding results show presence of fractured to highly-fractured sandstone. A test bore hole drilled at one of the locations yields a continuous discharge of ground water over 20,000 l/h. Present study clearly demonstrates that the GP survey is a powerful initial technique to identify the presence of fractures in hard rock areas and subsequent application of geoelectrical sounding at selected locations is very helpful for quantitative investigations.

Yadav, G. S.; Singh, Shashi Kant

2007-07-01

64

High performance ground penetrating radar survey of TA-49/Area 2. Final report  

SciTech Connect

The results of high performance ground penetrating radar study of Area 2 at Technical Area 49 are presented. The survey was commissioned as part of Los Alamos Laboratory`s continuing Environmental Remediation program and was completed and analyzed before borehole studies in Area 2 were started. Based upon the ground penetrating radar results, the location of one of the planned boreholes was moved to assure the drilling area was as safe as possible. While earlier attempts to use commercial radar devices at this facility had not been successful, the radar and digital processing system developed at Los Alamos were able to significantly improve the buried physical detail of the site.

Hoeberling, R.F. [Los Alamos National Lab., NM (United States); Rangel, M.J. III [Analysis Programming Processing Instrumentation, Santa Barbara, CA (United States)

1994-09-01

65

Researching Organizational Culture Using the Grounded Theory Method  

Microsoft Academic Search

Researching organizational culture using the grounded theory method is intuitively logical, given the ease of conceptualising organizational culture as a basic social process. In spite of its intuitive appeal, there are numerous challenges along the research voyage that could facilitate or jeopardise the unsuspecting researcher's investigation. The aim of this paper is to alert prospective researchers, to some of the

Noel Pearse; MacDonald Kanyangale

66

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

67

Storage and retrieval of ground-water data at the U.S. Geological Survey  

USGS Publications Warehouse

The U.S. Geological Survey maintains a computerized Ground-Water Site-Inventory (GWSI) file that contains information about wells and springs at sites from all States of the United States. This file contains data collected by U.S. Geological Survey personnel and personnel of cooperating State, local and Federal agencies. The file is easily accessible to members or users of the National Water Data Exchange. Since the establishment of the GWSI file in 1974, the data base has grown 19% per year and contains information on about 770,000 sites as of February 1981. (USGS)

Mercer, Maria W.; Morgan, Charles O.

1982-01-01

68

Ground-based thermal infrared surveys of Mount Rainier volcano, Washington  

Microsoft Academic Search

Detailed, ground-based thermal surveys of selected slopes of Mount Rainier, Washington, utilizing a Barnes PRT-5 Radiation\\u000a Thermometer have provided quantitative data for the construction of thermal contour maps of portions of the upper flanks of\\u000a this volcano. The thermal imagery, done in August, 1973, did not locate any suspect thermal areas on the northwest face of\\u000a Little Tahoma Peak, the

I. M. Lange; J. C. Avent

1974-01-01

69

Simulation of a ground-layer adaptive optics system for the Kunlun Dark Universe Survey Telescope  

NASA Astrophysics Data System (ADS)

Ground Layer Adaptive Optics (GLAO) is a recently developed technique extensively applied to ground-based telescopes, which mainly compensates for the wavefront errors induced by ground-layer turbulence to get an appropriate point spread function in a wide field of view. The compensation results mainly depend on the turbulence distribution. The atmospheric turbulence at Dome A in the Antarctic is mainly distributed below 15 meters, which is an ideal site for applications of GLAO. The GLAO system has been simulated for the Kunlun Dark Universe Survey Telescope, which will be set up at Dome A, and uses a rotating mirror to generate several laser guide stars and a wavefront sensor with a wide field of view to sequentially measure the wavefronts from different laser guide stars. The system is simulated on a computer and parameters of the system are given, which provide detailed information about the design of a practical GLAO system.

Jia, Peng; Zhang, Sijiong

2013-07-01

70

Comparison of methods for calibrating AVIRIS data to ground reflectance  

NASA Technical Reports Server (NTRS)

We are comparing three basic methods of calibrating AVIRIS data to ground reflectance: (1) atmospheric radiative transfer models with the solar flux can be used to calibrate AVIRIS radiance data (Specific methods include the University of Colorado CSES ARP and ATREM algorithms); (2) Robert Green's modified MODTRAN and AVIRIS radiance model (This method is similar to 1 but differs in that the solar radiance is bypassed, so any errors in the solar flux are canceled, too); and (3) ground calibration using known sites in the AVIRIS scene. We are using 1992AVIRIS data over Cuprite, Nevada, and Blackhawk Island, Wisconsin, as our test scenes. Both these sites have extensive field measurements. The Cuprite site had a very clear atmosphere, thus path radiance was dominated by Rayleigh scattering with little or no flux beyond 1 micron. The Blackhawk site has more aerosols, with significant path radiance flux beyond 2 micron.

Clark, Roger N.; Swayze, Gregg; Heidebrecht, Kathy; Goetz, Alexander F. H.; Green, Robert O.

1993-01-01

71

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

72

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

73

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

74

Design and Construction of Residential Slabs-on-Ground: State of the Art. Volume II: Literature Survey.  

National Technical Information Service (NTIS)

The literature survey concerning design and construction of residential slabs - on - ground on which this annotated bibliography is based was conducted by searching three separate data files in two data banks: the National Technical Information Service Fi...

1979-01-01

75

Ground-penetrating radar surveying in support of archeological site investigations  

NASA Astrophysics Data System (ADS)

In April and July of 1996, ground-penetrating radar (GPR) surveys were conducted in support of archeological investigations at Flagstaff, Arizona and Sebastian, Florida, respectively. A GSSI SIR System 8 radar unit with a 500-MHz monostatic antenna was used for both surveys. The Flagstaff, Arizona survey was conducted at Elden Pueblo Ruins. The site is located in a coniferous forest and characterized by a myriad of surficial and subsurface features. Surficial features consisted mostly of pottery shards and the remnants of rock walled structures. The subsurface features consist mostly of rock lined pits, stone walls, and grave sites covered by a soil layer of variable thickness. The soil is derived from volcanic clastics and the underlying Kaibab Limestone bedrock. GPR profiles were acquired across various locations, some of which had been previously excavated and backfilled by archeologists. The main objectives were to determine the utility of the GPR technique with respect to locating subsurface features of archeological interest, determine the optimum field parameters in the area, and direct further field work. The Sebastian, Florida survey was conducted along the Atlantic coastline. Data were acquired along five beaches and one coastal sand dune. The beaches and dunes of the area are composed of a medium to coarse grained sand, containing quartz grains and carbonates. The principle objective of the Sebastian, Florida survey was to locate wreckage from a Spanish treasure fleet. A secondary objective was to determine the utility of GPR in a near shore marine environment.

Baker, Jesse A.; Anderson, Neil L.; Pilles, Peter J.

1997-12-01

76

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

77

New method for lightning location using optical ground wire  

NASA Astrophysics Data System (ADS)

A new technology of lightning location is described, which is based on detecting the state of polarization (SOP) fluctuation of the laser light in the optic ground wire (OPGW). Compared with the conventional lightning location method, the new method is more accurate, more stable, and cheaper. Theories of Stokes parameters and Poincare sphere are introduced to analyze the SOP at the lightning strike point. It can be concluded that although the initial points of SOP on the Poincare sphere are random, the SOP fluctuation generated by lightning strike can still be accurately identified by detecting the velocity of polarization motion. A new algorithm to quantify the velocity is also introduced.

Qin, Zhaoyu; Cheng, Zhaogu; Zhang, Zhiping; Zhu, Jianqiang; Li, Feng

2006-12-01

78

A method for reducing ground reflection effects from acoustic measurements  

NASA Technical Reports Server (NTRS)

The method involved placing foam blocks on the ground between sound source and receiver in an approximation of the wedges in an anechoic chamber. The tests were performed out of doors as a function of the receiver height and source-receiver separation distance. The spacing between blocks and the extent of ground covered were varied to estimate the optimum placement and minimum amount of foam treatment needed. Base-line tests without foam were also performed. It was found that the foam treatment reduced the amplitude of the peaks and valleys in the sound pressure spectra substantially. The foam was least effective at low frequency, especially for the low receiver height and for large source-receiver distances. Results from the base-line tests were compared with theoretically predicted results. These base-line test results were in reasonable agreement with those from theory.

Noerager, J. A.; Rice, E. J.; Feiler, C. E.

1972-01-01

79

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

80

Survey of methods for rapid spin reversal  

SciTech Connect

The need for rapid spin reversal technique in polarization experiments is discussed. The ground-state atomic-beam source equipped with two rf transitions for hydrogen can be reversed rapidly, and is now in use on several accelerators. It is the optimum choice provided the accelerator can accept H/sup +/ ions. At present all rapid reversal experiments using H/sup -/ ions are done with Lamb-shift sources; however, this is not a unique choice. Three methods for the reversal of the spin of the atomic beam within the Lamb-shift source are discussed in order of development. Coherent intensity and perhaps focus modulation seem to be the biggest problems in both types of sources. Methods for reducing these modulations in the Lamb-shift source are discussed. The same Lamb-shift apparatus is easily modified to provide information on the atomic physics of quenching of the 2S/sub 1/2/ states versus spin orientation, and this is also discussed. 2 figures.

McKibben, J.L.

1980-01-01

81

Methods of the International Tobacco Control (ITC) China Survey  

Microsoft Academic Search

This paper describes the design features, data collection methods and analytical strategies of the ITC China Survey, a prospective cohort study of 800 adult smokers and 200 adult non-smokers in each of six cities in China . In addition to features and methods which are common to ITC surveys in other countries, the ITC China Survey possesses unique features in

Changbao Wu; Mary E Thompson; Geoffrey T Fong; Qiang Li; Yuan Jiang; Yan Yang; Guoze Feng

2009-01-01

82

Ground-based thermal infrared surveys as an aid in predicting volcanic eruptions in the cascade range.  

PubMed

Detailed, ground-based thermal surveys of selected slopes of Mt. Rainier and Mt. Lassen have provided quantitative data for the construction of thermal contour maps of portions of the flanks of these volcanoes. Preliminary surveys substantiate the existence of one suspected thermal anomaly on Mt. Rainier. PMID:17749308

Lange, I M; Avent, J C

1973-10-19

83

Ground-Based Thermal Infrared Surveys as an Aid in Predicting Volcanic Eruptions in the Cascade Range  

Microsoft Academic Search

Detailed, ground-based thermal surveys of selected slopes of Mt. Rainier and Mt. Lassen have provided quantitative data for the construction of thermal contour maps of portions of the flanks of these volcanoes. Preliminary surveys substantiate the existence of one suspected thermal anomaly on Mt. Rainier.

Ian M. Lange; Jon C. Avent

1973-01-01

84

Adaptive tracking method for ground target of FLIR imaging  

NASA Astrophysics Data System (ADS)

An adaptive tracking method for ground target in FLIR image including centric and eccentric tracking is presented in this paper. The eccentric tracking is adopted to assist ATR or manual target acquisition by stabilizing the light axis of the seeker. The tracking adaptability detection at the start of centric tracking avoids tracking bad locked point and decreases the shift, slide and jump in the subsequent tracking. Combination of periodic template-updating based on scale variance rate and interruptive template-updating based on supervision of tracking point enhances the adaptability of tracking template. Supervision, modification of current tracking point and the combination of direct and indirect tracking increase the stability of tracking system. The multi-scale and size-variable template is adopted to fit the variable target scale. The detection and adoption of occlusion mask increase the accuracy of the tracking system. The hardware system based on multi-DSP takes a real-time parallel processing. The trial results show that this method is efficient to reduce the possibility of shift, slide, and jump in ground target tracking comparing with the traditional correlation tracking method.

Li, Yun; Zhang, Tianxu; Zuo, Zhengrong; Wan, Meijun

2009-10-01

85

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

86

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

87

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

88

Potential Applications of Acoustic Emission Technology as a Nondestructive Evaluation Method for Naval Aviation Ground Support.  

National Technical Information Service (NTIS)

This report presents the results of a survey of the potential use of acoustic emission monitoring for specific inspection and maintenance tasks in performance of ground support of Naval aircraft. One potential application, detecting corrosion in composite...

W. F. Hartman

1978-01-01

89

The Use of National Survey Data in Teaching Methods of Survey Research.  

ERIC Educational Resources Information Center

A description is given of a college course in survey research and attitudinal measurement offered by the School of Education at the University of Louisville. The graduate level course focuses on the principles of social research; survey research methods; and data analysis, interpretation, and application. National survey data are used to teach all…

Egginton, Everett

90

Revisions to the U.S. Geological Survey's MODFLOW Lake Package for Simulation of Ground-Water Interactions With Lakes  

NASA Astrophysics Data System (ADS)

Several revisions were made to the U.S. Geological Survey's MODFLOW Lake Package as part of the integration of the Precipitation-Runoff Modeling System with MODFLOW. The integrated model, named GSFLOW, is designed for the simultaneous simulation of ground-water and surface-water flow. Revisions to the Lake Package resulted in changing: (1) the numerical solution to simultaneously solve for lake stage and outflow to streams; (2) the method of calculating lake-water budgets to maintain a budget when a lake is empty; and (3) the calculation of leakage across the lakebed in areas where the water table is below the lakebed. The first change was done to reduce numerical instabilities in the calculation of lake outflow to streams. The second change was done to allow for intermittent lakes to refill on the basis of surface water inflow and to limit leakage across the lakebed to the surface-water inflow when the lake is empty. The third change was done to account for flow through an unsaturated zone beneath lakes. These revisions allow for greater flexibility in the simulation of ground-water interactions with lakes. Possible new applications for the revised Lake Package include the simulation of ground-water interaction with: (1) intermittent lakes that fill and drain as a result of seasonal changes in surface-water inflow; (2) reservoirs that fill during wet periods and are drained during droughts; (3) flood plains of streams that are inundated periodically by floods; (4) anastomosing flood plains where larger channels correspond to more than one MODFLOW cell; and (5) areas beneath lakes that are separated from ground water by an unsaturated zone.

Prudic, D. E.; Niswonger, R. G.

2006-12-01

91

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

1991-01-01

92

Helium and ground temperature surveys at Steamboat Springs, Colorado. Special Publication 21  

Microsoft Academic Search

As demonstrated in Steamboat Springs, Colorado, helium and shallow temperature surveys are quick, inexpensive geothermal exploration methods that can be used together with excellent results in an urban environment. Steamboat Springs, in northwestern Colorado, lies primarily upon terrace gravels and alluvium with the major structure being a north-trending normal fault passing through the western portion of the city. Work by

K. P. McCarthy; J. Been; G. M. Reimer; C. G. Bowles; D. G. Murrey

1982-01-01

93

Eighth Conference on Health Survey Research Methods.  

National Technical Information Service (NTIS)

Contents: Foreword; Acknowledgments; Session 1: Capturing Diversity and Change in a Dynamic Population; Session 2: Community Participation and Community Benefit; Session 3: Cross-Cultural Challenges in Health Survey Research; Session 4: How to Conduct Hea...

2004-01-01

94

The Luminex method: a new geophysical method for airborne and ground prospecting for ore deposits  

Microsoft Academic Search

The examples shown here indicate the ability of the Luminex method, to detect, either from the air or on the ground, luminescent minerals related to certain deposits of tungsten, molybdenum, zinc, gold and uranium. In addition, other tests of the method have yielded positive responses over tin deposits. The luminescent responses obtained are sometimes related to the presence of key

H. O. Seigel; J. C. Robbins

1983-01-01

95

Method and apparatus for cascaded ground return amplifier  

US Patent & Trademark Office Database

A cascaded amplifier is integrated within an integrated circuit with a cascaded ground bus. The cascaded ground bus provides two ground points at opposite ends. Each amplifier ground of each amplifier stage couples to the ground wire there between. The cascaded ground bus substantially reduces the parasitic inductance in the emitter leg of each IC transistor within each amplifier. The lay out of the cascaded ground bus wire is tightly coupled to the lay out of the input wires so that their respective parasitic inductances are magnetically coupled together to form a mutual inductance. The mutual inductance effectively cancels the effect of the ground return inductance due to them being similar inductance values and having the same ground loop current flowing through them in opposite directions. The cascaded ground bus can be utilized in substantially all amplifier types including class A, B, C, D, BD, E, F, G, H, S and their variations and with substantially all transistor types used within amplifier stages including bipolar junction transistors, field effect transistors and their variants (i.e. PNP, NPN, MOSFET, NFET, PFET, JFET, MESFET, etc.). An IC cascaded amplifier with the cascaded ground bus can be utilized in a number of communication systems where amplification is needed including battery operated systems such as a transceiver of a portable cellular telephone.

2001-10-09

96

REEVALUATION OF EXISTING GROUND STRUCTURE MODEL GAINED THROUGH MICROTREMOR ARRAY METHOD BY USING FUNDAMENTAL PROPERTIES OF MODEL SURVEIED THROUGH H/V SPECTRUM - ON GROUND STRUCTURE OF FUKUI PLAIN -  

NASA Astrophysics Data System (ADS)

In order to reduce discrepancies between ground models based on the microtremor array observation in Fukui Plain and models by the H/V survey method and gravity analysis, the existing array ground models were reevaluated. The representative of the dispersion curves was selected so as to fit a theoretical fundamental mode dispersion curve of the H/V ground model. By using the method of selection, a reasonable reevaluation became possible. As a result the correspondences among the three models were much improved as a whole, but in the edge site of the Plain the differences against the gravity model are not reduced.

Yasui, Yuzuru; Hashimoto, Yuichi; Noguchi, Tatsuya; Kagawa, Takao

97

Helium and ground temperature surveys at Steamboat Springs, Colorado. Special Publication 21  

SciTech Connect

As demonstrated in Steamboat Springs, Colorado, helium and shallow temperature surveys are quick, inexpensive geothermal exploration methods that can be used together with excellent results in an urban environment. Steamboat Springs, in northwestern Colorado, lies primarily upon terrace gravels and alluvium with the major structure being a north-trending normal fault passing through the western portion of the city. Work by Christopherson (1979) indicates that the Steamboat warm springs are not laterally connected at shallow depth with Routt Hot Springs, 10 Km (6 mi) to the north, although both resource areas are fault controlled. A shallow temperature survey was conducted in the city to determine the usefulness of this method to delineate a low temperature resource. Several extraneous factors influencing shallow temperature measurements were dealt with by field technique or subsequent analysis. A helium survey was conducted to compare with temperature results. Sixty-two soil helium samples were taken, using an interval of .1 to .2 Km (.06 to .12 mi), twice the density of the 18 temperature probe stations. A mobile spectrometer allowed immediate analysis of helium samples. The contoured data from each method correlate well spatially and indicate that two faults control the resource in Steamboat Springs. Although these surveys should always be used to supplement other data, their utility in this study was readily apparent.

McCarthy, K.P.; Been, J.; Reimer, G.M.; Bowles, C.G.; Murrey, D.G.

1982-01-01

98

Ground penetrating radar surveys of peatlands for oilfield pipelines in Canada  

NASA Astrophysics Data System (ADS)

Placement of buried pipelines in thick peat deposits is difficult because of the low bearing strength and high water content of the material for support of heavy construction equipment. Previously, ground penetrating radar (GPR) has been used to assess thickness and volume of peat as a fuel resource and horticultural material in Scandinavia and Canada. To our knowledge, GPR has not been applied to the site assessment and placement of pipelines crossing peatlands. Field experiments were conducted in the Mitsue oilfield operated by Chevron Canada Resources Ltd., located immediately southeast of Lesser Slave Lake in north-central Alberta Province, Canada. Surficial deposits consist of Holocene, linear, sandy beach ridges separated by peatlands underlain by sand. Several GPR surveys assessed the thickness of the peat along two oil pipeline right-of-ways. Results show the peat-sand contact as irregular and undulating, ranging from 0 to 3.7 m deep. Each survey, 460 and 550 m long, was completed in two hours. Such results from 1 m station spacings (sampling interval) can considerably reduce the uncertainties in planning and placement of oil, gas, and water pipelines crossing peatlands. Results indicate that thickness variations of peat can be detected more effectively in terms of quality of results, lower cost, and less time with GPR than with a peat probe or by coring.

Jol, Harry M.; Smith, Derald G.

1995-12-01

99

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

100

Antenna characteristics and air-ground interface de-embedding methods for stepped-frequency ground-penetrating radar measurements  

Microsoft Academic Search

The result form field-tests using a Stepped-Frequency Ground Penetrating Radar (SF-GPR) and promising antenna and air- ground deembedding methods for a SF-GPR is presented. A monostatic S-band rectangular waveguide antenna was used in the field-tests. The advantages of the SF-GPR, e.g., amplitude and phase information in the SF-GPR signal, is used to deembed the characteristics of the antenna. We propose

Brian Karlsen; Jan Larsen; Kaj B. Jakobsen; Helge B. Sorensen; Steffan Abrahamson

2000-01-01

101

Application of a Modified Universal Design Survey for Evaluation of Ares 1 Ground Crew Worksites  

NASA Technical Reports Server (NTRS)

Operability is a driving requirement for NASA's Ares 1 launch vehicle. Launch site ground operations include several operator tasks to prepare the vehicle for launch or to perform maintenance. Ensuring that components requiring operator interaction at the launch site are designed for optimal human use is a high priority for operability. To support design evaluation, the Ares 1 Upper Stage (US) element Human Factors Engineering (HFE) group developed a survey based on the Universal Design approach. Universal Design is a process to create products that can be used effectively by as many people as possible. Universal Design per se is not a priority for Ares 1 because launch vehicle processing is a specialized skill and not akin to a consumer product that should be used by all people of all abilities. However, applying principles of Universal Design will increase the probability of an error free and efficient design which is a priority for Ares 1. The Design Quality Evaluation Survey centers on the following seven principles: (1) Equitable use, (2) Flexibility in use, (3) Simple and intuitive use, (4) Perceptible information, (5) Tolerance for error, (6) Low physical effort, (7) Size and space for approach and use. Each principle is associated with multiple evaluation criteria which were rated with the degree to which the statement is true. All statements are phrased in the utmost positive, or the design goal so that the degree to which judgments tend toward "completely agree" directly reflects the degree to which the design is good. The Design Quality Evaluation Survey was employed for several US 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

102

30 CFR 77.701-2 - Approved methods of grounding metallic frames, casings, and other enclosures of electric...  

Code of Federal Regulations, 2013 CFR

...Approved methods of grounding metallic frames...direct-current power system. 77.701-2...Approved methods of grounding metallic frames...direct-current power system. (a) The following methods of grounding metallic...

2013-07-01

103

30 CFR 77.701-2 - Approved methods of grounding metallic frames, casings, and other enclosures of electric...  

Code of Federal Regulations, 2010 CFR

...Approved methods of grounding metallic frames...direct-current power system. 77.701-2...Approved methods of grounding metallic frames...direct-current power system. (a) The following methods of grounding metallic...

2009-07-01

104

30 CFR 77.701-2 - Approved methods of grounding metallic frames, casings, and other enclosures of electric...  

Code of Federal Regulations, 2010 CFR

...Approved methods of grounding metallic frames...direct-current power system. 77.701-2...Approved methods of grounding metallic frames...direct-current power system. (a) The following methods of grounding metallic...

2010-07-01

105

Corrosion control survey methods for offshore pipelines  

SciTech Connect

Construction, operation, and maintenance of offshore pipelines and other facilities are expensive. The consequences of an offshore corrosion failure can be devastating. For these reasons, cathodic protection (CP) has become a universally applied technique for mitigating corrosion. Marine pipelines are typically provided with CP by bracelet anodes of zinc or aluminum. Impressed current systems at platforms or onshore are also used as well as hybrid systems that use a combination of the two. In this paper survey techniques are described and evaluated.

Weldon, C.P.; Kroon, D. (Corrpro Co. Inc., North, Spring, TX (US))

1992-02-01

106

A Survey on the p-Cycle Protection Method  

Microsoft Academic Search

This paper presents a comprehensive survey for the pre-configured cycle (p-cycle) protection method which is a relatively new scheme for network survivability with many interesting properties, and has been attracting quite a lot of attention. We review different aspects of p-cycles and survey the studies on this and other related survivability schemes. This survey paper is the first attempt to

Mohammad S. Kiaei; Chadi Assi; Brigitte Jaumard

2009-01-01

107

Comparison between staggered grid finite difference method and stochastic method in simulating strong ground motions  

Microsoft Academic Search

Strong ground motion of an earthquake is simulated by using both staggered grid finite difference method (FDM) and stochastic\\u000a method, respectively. The acceleration time histories obtained from the both ways and their response spectra are compared.\\u000a The result demonstrates that the former is adequate to simulate the low-frequency seismic wave; the latter is adequate to\\u000a simulate the high-frequency seismic wave.

Man-Sheng Wang; Hui Jiang; Yu-Xian Hu

2005-01-01

108

Geophysical survey at cluster 6, Westwood Area, US Army Aberdeen Proving Ground. Final report  

SciTech Connect

A geophysical investigation was conducted at Cluster 6 Site 5, located in Westwood Area of the U.S. Army Aberdeen Proving Ground. This site is the former Westwood Area Radioactive Material Disposal Facility (WRMDF) which was used for processing and packaging radioactive waste material prior to disposal. Original structures at the site included Building 3013 and adjacent concrete slabs where the waste handling work was performed, a small equipment shed, and a wastewater holding and drain system which included tanks in a concrete pit. Discharge of wastewater from the tanks was to Reardon Inlet, located a short distance south of the tank pit. Possible release of radioactive waste to the environment would have been due to either spillage, leakage, or discharge from the wastewater system. Two terra cotta pipelines, one on the western end and one of the eastern end, extended from Building 3013 to Reardon Inlet. The east pipeline handled low-level radioactive wastewater. The west pipeline was the original wastewater line and it is presumed that radioactive wastewater was not discharged through this line. After radioactive waste handling activities were discontinued at WRMDF, the west pipeline system was upgraded to include a septic tank, sand filter bed, and a chlorine contact chamber. The structures associated with the WRMDF were removed during the early 1970`s, including the concrete tank pit. Both pipelines are visible near the edge of Reardon inlet, suggesting that the pipes and related structures have not been removed. Geophysical surveys, including magnetics, electromagnetics (EM), and ground penetrating radar, were performed to identify the location of the two terra cotta pipes, septic tank, and sand filter bed.

Simms, J.E.; Harrelson, D.W.; Sharp, M.K.

1995-05-01

109

Robust Control Methods a Systematic Survey  

NASA Astrophysics Data System (ADS)

The paper addresses the problem how to recognize a level of robust controller design and is aimed show the difficulties of implementation for practical use. In the first part of paper we introduce the survey of robust controller design for SISO systems with generalization design procedure for structured and unstructured uncertainties. The second part of paper is devoted to MIMO systems. In the frequency domain robust controller design procedure we reduce to independent design of SISO subsystems and in time domain the LMI or BMI approaches with polytopic system description are favorable.

Veselý, Vojtech

2013-01-01

110

A survey on evaluation methods for image interpolation  

Microsoft Academic Search

Image interpolation is applied to Euclidean, affine and projective transformations in numerous imaging applications. However, due to the unique characteristics and wide applications of image interpolation, a separate study of their evaluation methods is crucial. The paper studies different existing methods for the evaluation of image interpolation techniques. Furthermore, an evaluation method utilizing ground truth images for the comparisons is

Angelos Amanatiadis; Ioannis Andreadis

2009-01-01

111

Retail security: a survey of methods and management in Dundee  

Microsoft Academic Search

Outlines preliminary results from a survey into retail security methods employed by retailers in central Dundee, and forms part of ongoing research into retail crime in this city being undertaken on a joint basis by the University of Abertay Dundee, and Tayside Police. Considers it to be the first survey of this type undertaken at such a local level in

Mike Pretious; Robert Stewart; David Logan

1995-01-01

112

Survey of numerical methods for compressible fluids  

SciTech Connect

The finite difference methods of Godunov, Hyman, Lax-Wendroff (two-step), MacCormack, Rusanov, the upwind scheme, the hybrid scheme of Harten and Zwas, the antidiffusion method of Boris and Book, and the artificial compression method of Harten are compared with the random choice known as Glimm's method. The methods are used to integrate the one-dimensional equations of gas dynamics for an inviscid fluid. The results are compared and demonstrate that Glimm's method has several advantages. 16 figs., 4 tables.

Sod, G A

1977-06-01

113

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

114

30 CFR 77.701-1 - Approved methods of grounding of equipment receiving power from ungrounded alternating current...  

Code of Federal Regulations, 2010 CFR

...Approved methods of grounding of equipment...current power systems. 77.701-1...current power systems. For purposes of grounding metallic frames...current power systems, the following methods of grounding will be...

2010-07-01

115

30 CFR 77.701-1 - Approved methods of grounding of equipment receiving power from ungrounded alternating current...  

Code of Federal Regulations, 2010 CFR

...Approved methods of grounding of equipment...current power systems. 77.701-1...current power systems. For purposes of grounding metallic frames...current power systems, the following methods of grounding will be...

2009-07-01

116

30 CFR 75.701-1 - Approved methods of grounding of equipment receiving power from ungrounded alternating current...  

Code of Federal Regulations, 2010 CFR

...Approved methods of grounding of equipment...current power systems. 75.701-1...current power systems. For purposes of grounding metallic frames...current power systems, the following methods of grounding will be...

2010-07-01

117

30 CFR 75.701-1 - Approved methods of grounding of equipment receiving power from ungrounded alternating current...  

Code of Federal Regulations, 2010 CFR

...Approved methods of grounding of equipment...current power systems. 75.701-1...current power systems. For purposes of grounding metallic frames...current power systems, the following methods of grounding will be...

2009-07-01

118

30 CFR 77.701-1 - Approved methods of grounding of equipment receiving power from ungrounded alternating current...  

Code of Federal Regulations, 2013 CFR

...Approved methods of grounding of equipment...current power systems. 77.701-1...current power systems. For purposes of grounding metallic frames...current power systems, the following methods of grounding will be...

2013-07-01

119

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

120

The Luminex method: a new geophysical method for airborne and ground prospecting for ore deposits  

SciTech Connect

The examples shown here indicate the ability of the Luminex method, to detect, either from the air or on the ground, luminescent minerals related to certain deposits of tungsten, molybdenum, zinc, gold and uranium. In addition, other tests of the method have yielded positive responses over tin deposits. The luminescent responses obtained are sometimes related to the presence of key ore minerals or pathfinder minerals and, at other times, to alteration minerals in the same environment. The sensitivity of the method is very high, so that key minerals may be detected even when present in much less than ore grade amounts.

Seigel, H.O.; Robbins, J.C.

1983-03-01

121

Terrestrial Amphibians and Mollusks: Evaluation of an Integrated Survey Method.  

National Technical Information Service (NTIS)

We developed and evaluated an integrated sampling method to determine presence of terrestrial amphibian and mollusk species. Our goal was to be more efficient at locating both taxa during the same field surveys. Our protocol employed standardized Time (TC...

D. J. Major R. B. Bury

2004-01-01

122

Brief Survey of Knowledge Aggregation Methods.  

National Technical Information Service (NTIS)

This paper discusses several iterative knowledge aggregation methods. Such methods are used to choose one of a finite set of labels about each of a set of objects. First, a stimulus is analyzed locally at each object, yielding an initial state which assig...

M. S. Landy R. A. Hummel

1985-01-01

123

Disorientation Training in FAA-Certificated Flight and Ground Schools: A Survey.  

National Technical Information Service (NTIS)

A 10-item, voluntary questionnaire answered by 674 flight and ground schools provided information on (1) the conduct of formal instruction about disorientation, (2) the occurrence and content of lectures on disorientation, (3) use of on-the-ground demonst...

W. E. Collins A. H. Hasbrook A. O. Lennon D. J. Gay

1977-01-01

124

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

125

Survey of Research Methods to Study Design.  

National Technical Information Service (NTIS)

This report identifies and evaluates methods used by the design research community that could be used to establish requirements for improving the effectiveness of the engineering design process in a Unified Life Cycle Engineering (ULCE) environment. More ...

D. A. Dierolf K. J. Richter M. Brei

1989-01-01

126

Applied Survey Methods for Development Projects.  

National Technical Information Service (NTIS)

Scientific sampling methods can reduce the need for detailed recordkeeping, reporting, and accounting, and can provide useful data to project personnel. This step-by-step illustrative guide is thus designed to familiarize A.I.D. personnel responsible for ...

1981-01-01

127

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

128

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

129

A survey of modern authorship attribution methods  

Microsoft Academic Search

Authorship attribution supported by statistical or computational methods has a long history starting from 19th century and marked by the seminal study of Mosteller and Wallace (1964) on the authorship of the disputed Federalist Papers. During the last decade, this scientific field has been developed substantially taking advantage of research advances in areas such as machine learning, information retrieval, and

Efstathios Stamatatos

2009-01-01

130

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

131

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

132

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

133

Seasonal changes in groundwater storage estimated by absolute ground gravity and MRS surveys in West Africa  

NASA Astrophysics Data System (ADS)

Important and fast groundwater storage changes occur in tropical monsoon regions in response to seasonal rainfall and subsequent surface water redistribution. In West Africa, one main goal of the GHYRAF experiment (Gravity and Hydrology in Africa, 2008-2010) is to compare absolute gravimetric measurements with dense hydrological surveys to better estimate and model water storage changes at various time scales. Magnetic Resonance Sounding (MRS) is a non-invasive geophysical method having a signal directly related to groundwater quantity. In SW Niger, MRS surveys were performed concurrently with gravimetric (FG5) measurements for monitoring seasonal changes in groundwater storage. Water table levels were recorded on a 4-piezometers profile (~500 m) near a temporary pond (area ~2 ha) fed by sandy gullies. The volume of water drained from the pond to the phreatic aquifer was computed to be ~100,000 m3/yr. Large piezometric fluctuations (3-6 m) occurred in response to indirect recharge through the pond during the 2008 rainy season (July-Sept.), with stronger water table fluctuations recorded near the pond. Absolute gravimetric (FG5) measurements were performed at a distance of 150 m from the pond, in order to minimize the influence of 2D effects on gravimetric records. The increase in absolute gravity measured between two dates (July-Sept.) was 8.7 ± 2.6 µGal; for the same period, the measured water table rise was +3.0 m. Considering these values, a first estimate of the groundwater storage increase is 0.2 m, corresponding to a porosity filled up by the water table rise of ~7%. Repeated MRS surveys were performed at the same location for different dates (three soundings in Sept., one in Dec.). The MRS water content was 13%, with little variation in space (±3%) along the piezometric profile. In response to a 3 metres drop in the water table (Sept- Dec), there was no significant recorded change in the MRS water content and/or in the estimated MRS water table depth. MRS and absolute gravimetry are two independent methods that could be sensitive to changes in groundwater reserves. However, because MRS is integrative of the whole saturated thickness of the aquifer (here, a few tens of metres), it was shown to be comparatively less sensitive to groundwater storage fluctuations occurring at the water table. These methods provide complementary data on aquifer characteristics, MRS being useful for quantifying lateral changes in aquifer properties, whereas gravimetric measurements helped in characterizing groundwater recharge and porosity. Both methods bring pieces of information that could be used to better constrain transient groundwater modelling at site scale.

Favreau, G.; Boucher, M.; Luck, B.; Pfeffer, J.; Genthon, P.; Hinderer, J.

2009-04-01

134

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.

2013-01-01

135

A Survey of Fast Exponentiation Methods  

Microsoft Academic Search

Public-key cryptographic systems often involve raising elements of some group (e.g. GF(2n), Z\\/NZ, or elliptic curves) to large powers. An important question is how fast this exponentiation can be done, which often determines whether a given system is practical. The best method for exponentiation depends strongly on the group being used, the hardware the system is implemented on, and whether

Daniel M. Gordon

1998-01-01

136

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.

Grasset, E.

1957-01-01

137

Methods for Bayesian Power Spectrum Inference with Galaxy Surveys  

NASA Astrophysics Data System (ADS)

We derive and implement a full Bayesian large scale structure inference method aiming at precision recovery of the cosmological power spectrum from galaxy redshift surveys. Our approach improves upon previous Bayesian methods by performing a joint inference of the three-dimensional density field, the cosmological power spectrum, luminosity dependent galaxy biases, and corresponding normalizations. We account for all joint and correlated uncertainties between all inferred quantities. Classes of galaxies with different biases are treated as separate subsamples. This method therefore also allows the combined analysis of more than one galaxy survey. In particular, it solves the problem of inferring the power spectrum from galaxy surveys with non-trivial survey geometries by exploring the joint posterior distribution with efficient implementations of multiple block Markov chain and Hybrid Monte Carlo methods. Our Markov sampler achieves high statistical efficiency in low signal-to-noise regimes by using a deterministic reversible jump algorithm. This approach reduces the correlation length of the sampler by several orders of magnitude, turning the otherwise numerically unfeasible problem of joint parameter exploration into a numerically manageable task. We test our method on an artificial mock galaxy survey, emulating characteristic features of the Sloan Digital Sky Survey data release 7, such as its survey geometry and luminosity-dependent biases. These tests demonstrate the numerical feasibility of our large scale Bayesian inference frame work when the parameter space has millions of dimensions. This method reveals and correctly treats the anti-correlation between bias amplitudes and power spectrum, which are not taken into account in current approaches to power spectrum estimation, a 20% effect across large ranges in k space. In addition, this method results in constrained realizations of density fields obtained without assuming the power spectrum or bias parameters in advance.

Jasche, Jens; Wandelt, Benjamin D.

2013-12-01

138

Electromagnetic survey of the K1070A burial ground at the Oak Ridge K-25 Site, Oak Ridge, Tennessee  

SciTech Connect

The K1070A burial ground, located at the K-25 Site on the Oak Ridge Reservation, received chemical and radioactive wastes from the late 1940s until 1975. Analysis of water samples collected from nearby monitoring wells indicates that contamination is migrating offsite. In November 1991, Oak Ridge National Laboratory (ORNL) personnel collected high-resolution electrical terrain conductivity data at the K1070A burial ground. A Model EM31 terrain conductivity meter manufactured by Geonics Limited was used in conjunction with the ORNL-developed Ultrasonic Ranging and Data System (USRADS) to perform the survey. The purposeof the survey was to provide Environmental Restoration (ER) staff with a detailed map of the spatial variation of the apparent electrical conductivity of the shallow subsurface (upper 3 m) to assist them in siting future monitoring wells closer to the waste area without drilling into the buried waste.

Nyquist, J.E.; Emery, M.S.

1993-01-01

139

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

140

A comparison of exact and quasi-static methods for evaluating grounding systems at high frequencies  

Microsoft Academic Search

Recently, it has been suggested that traditional quasi-static methods for evaluating grounding systems are not valid at high frequencies. However, the conditions under which exact full wave theory must be used have not been established. In this paper, exact full wave and quasi-static methods are used to evaluate touch and step potentials of a simple ground stake. It is shown

R. G. Olsen; M. C. Willis

1996-01-01

141

Statistical method to detect subsurface objects using array ground-penetrating radar data  

Microsoft Academic Search

We introduce a combination of high-dimensional analysis of variance (HANOVA) and sequential probability ratio test (SPRT) to detect buried objects from an array ground-penetrating radar (GPR) surveying a region of interest in a progressive manner. Using HANOVA, we exploit the transient characteristic of GPR signals in the time domain to extract information about buried objects at fixed positions of the

Xiaoyin Xu; Eric L. Miller; Carey M. Rappaport; Gary D. Sower

2002-01-01

142

Integration of ground-penetrating radar and microgravimetric methods to map shallow caves  

Microsoft Academic Search

Ground-penetrating radar (GPR) and microgravimetric surveys have been conducted in the southern Jura mountains of western Switzerland in order to map subsurface karstic features. The study site, La Grande Rolaz cave, is an extensive system in which many portions have been mapped. By using small station spacing and careful processing for the geophysical data, and by modeling these data with

Milan Beres; Marc Luetscher; Raymond Olivier

2001-01-01

143

Robust adaptive polarization analysis method for eliminating ground roll in 3C land seismics  

NASA Astrophysics Data System (ADS)

To improve the data quality of converted waves, and better identify and suppress the strong ground-roll interference in three-component (3C) seismic recordings on land, we present an adaptive polarization filtering method, which can effectively separate the groundroll interference by combining complex polarization and instantaneous polarization analysis. The ground roll noise is characterized by elliptical plane polarization, strong energy, low apparent velocity, and low frequency. After low-pass filtering of the 3C data input within a given time-window of the ground roll, the complex covariance matrix is decomposed using the sliding time window with overlapping data and length that depends on the dominant ground-roll frequency. The ground-roll model is established using the main eigenvectors, and the ground roll is detected and identified using the instantaneous polarization area attributes and average energy constraints of the ground-roll zone. Finally, the ground roll is subtracted. The threshold of the method is stable and easy to select, and offers good groundroll detection. The method is a robust polarization filtering method. Model calculations and actual data indicate that the method can effectively identify and attenuate ground roll while preserving the effective signals.

Chen, Hai-Feng; Li, Xiang-Yang; Qian, Zhong-Ping; Zhao, Gui-Ling

2013-06-01

144

Revisions to the U.S. Geological Survey's MODFLOW Lake Package for Simulation of Ground-Water Interactions With Lakes  

Microsoft Academic Search

Several revisions were made to the U.S. Geological Survey's MODFLOW Lake Package as part of the integration of the Precipitation-Runoff Modeling System with MODFLOW. The integrated model, named GSFLOW, is designed for the simultaneous simulation of ground-water and surface-water flow. Revisions to the Lake Package resulted in changing: (1) the numerical solution to simultaneously solve for lake stage and outflow

D. E. Prudic; R. G. Niswonger

2006-01-01

145

[Historical survey of modern reversible contraceptive methods].  

PubMed

Because of contraception, pregnancy need not be viewed by women as punishment for sexual activity but as a planned and desired event. Most of the contraceptive methods used in developing countries at present were introduced during the 1960s, but use of contraception has a long history and some methods date back to antiquity. Contraceptive pills were already used around 2000 BC in the form of mercury and arsenic tablets. Their effectiveness was questionable. The role of hormones in human reproduction began to be understood only in the early 1900s. The discovery of progesterone in a Mexican iguana in the 1940s permitted production of progesterone on a large scale. Estrogens had been identified around 1930. Human trials of a contraceptive pill beginning in 1956 in Puerto Rico demonstrated that progestins could prevent pregnancy by suppressing ovulation. Later on, estrogen was added to reduce menstrual irregularities. The 1st generation of combined oral contraceptives contained very high levels of hormones associated with high rates of side effects. Numerous formulations with lower hormonal contents became available beginning around 1970 and constitute the principal formulations in use today. A number of long acting hormonal methods based on progestins have been developed, including injectables, some IUDs and vaginal rings, and implants. The 1st commercially available injectable, norethisterone enanthate, did not acquire the wide distribution of medroxyprogesterone acetate, sold as Depo Provera and used to treat various pathological conditions as well as for contraception. The 1st true IUDs were small stones placed within the uteri of camels by nomads to prevent pregnancy during long caravans. An IUD was developed in 1909 by Richter, and the 2 most widely used models before 1960 were the Grafenberg and Ota silver rings. Use of the 2 rings became rare for medical reasons after 1935 despite their efficacy. Safe plastic IUDs which appeared beginning in the early 1960s were flexible and capable of returning to their original shape after insertion. The Lippes loop was the 1st highly successful IUD. Bioactive IUDs containing copper were developed in the 1970s. Research is underway to develop IUDs which will resist expulsion, reduce bleeding, be more appropriate for multiparas, and last longer. IUDs are used to treat intrauterine adhesions as well as for contraception. A gummy substance used to block the cervix was described in Egypt in 1850 BC. Japanese and Chinese prostitutes of antiquity placed oiled bamboo paper at the cervical opening for contraception. Diaphragms and cervical caps were developed in the 19th century in Germany. Large scale production became possible after 1880 with the development of better, more durable, and cheaper rubber. An Egyptian writing in 3500 BC began the study of spermicides. Numerous substances such as lemon juice and honey have been placed in the vagina to avoid pregnancy. Such substances are available to all women and some were reasonably effective. Current research is directed toward development of spermicides which will also prevent sexually transmitted diseases. The 1st condoms were made of animal skins by an English physician to prevent transmission of venereal diseases. Rubber condoms appeared in the early 20th century and are widely utilized in some family planning programs. Pregnancy vaccines and a reversible hormonal method for men are among methods under development. PMID:12268230

Mbabajende, V

1986-04-01

146

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)

edited by Mattraw, H. C., Jr.; Franks, B. J.

1984-01-01

147

Above-ground Forest Biomass Estimation by ALOS/PALSAR over Boreal Forest in Alaska Accompanied with Ground-based Forest Survey  

NASA Astrophysics Data System (ADS)

For the better understanding of the carbon cycle in the global ecosystem, investigations on the spatio-temporal variation of the carbon stock which is stored as vegetation biomass is important. The L-band microwave radar “PALSAR (Phased Array type L-band Synthetic Aperture Radar)” of the satellite “ALOS (Advanced Land Observing Satellite)” provides the information which can be used for the above-ground forest biomass (AGFB) estimation. An attempt to map the AGFB distribution over an ecotone region in Alaska was carried out based on ALOS/PALSAR data. In July 2007, a ground-based forest survey was executed in the south-north transect (about 500 km long) along a trans-Alaska pipeline which profiles the ecotone from boreal forest to tundra in Alaska. 29 forests along the transect were targeted for the survey, and their AGFB were measured. Consequently, it was revealed that the AGFB ranges from 5 to 100 ton/ha (dried matter). These ground-based AGFB measurements at 29 forests were compared with the signal (digital number) in 20 scenes of ALOS/PALSAR (HV polarization mode) that cover the 29 forests in July or August 2007. In addition, 16 areas of grassland in the images were picked for the reference value of the zero AGFB. The result showed a positive strong (r = 0.84) and linear relationship between them, demonstrating a feasibility of ALOS/PALSAR for the mapping of the AGFB. Based on the linear relationship, the AGFB was estimated and mapped over the ecotone region in Alaska. Generally, there is a south to north gradient in AGFB that reflects the AGFB gradient from southern forest-rich region to northern forest-sparse region in the ecotone. The AGFB in some regions in southern part reaches 100 Mg/ha.

Suzuki, R.; Kim, Y.; Ishii, R.; Nicoll, J.

2009-12-01

148

30 CFR 75.701-3 - Approved methods of grounding metallic frames, casings and other enclosures of electric equipment...  

Code of Federal Regulations, 2013 CFR

...current power systems with one polarity...the purpose of grounding metallic frames...direct-current power system with one polarity...following methods of grounding will be approved...conductor of the system; (c) Silicon diode grounding;...

2013-07-01

149

30 CFR 75.701-3 - Approved methods of grounding metallic frames, casings and other enclosures of electric equipment...  

Code of Federal Regulations, 2010 CFR

...current power systems with one polarity...the purpose of grounding metallic frames...direct-current power system with one polarity...following methods of grounding will be approved...conductor of the system; (c) Silicon diode grounding;...

2010-07-01

150

30 CFR 75.701-3 - Approved methods of grounding metallic frames, casings and other enclosures of electric equipment...  

Code of Federal Regulations, 2010 CFR

...current power systems with one polarity...the purpose of grounding metallic frames...direct-current power system with one polarity...following methods of grounding will be approved...conductor of the system; (c) Silicon diode grounding;...

2009-07-01

151

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

152

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

Microsoft Academic Search

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

PETERSEN SW

2010-01-01

153

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...

154

A Comprehensive Survey of Neighborhood-based Recommendation Methods  

Microsoft Academic Search

Among collaborative recommendation approaches, methods based on nearest-neighbors still enjoy a huge amount of popularity, due to their simplicity, their efficiency, and their ability to produce accurate and personalized recommenda- tions. This chapter presents a comprehensive survey of neighborhood-based meth- ods for the item recommendation problem. In particular, the main benefits of such methods, as well as their principal characteristics,

Christian Desrosiers; George Karypis

2011-01-01

155

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

156

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

157

Method of reflection point correlation seismic surveying  

SciTech Connect

A method of seismic exploration comprises transmitting waves from transmission sources into the medium to be explored and picking up signals in a receiver and recording these as traces, the signals being produced by reflection in the medium, the sequential transmission of the sources taking place at intervals less than the reflection time of the longest transmitted waves, the repeated transmission of any one source taking place at intervals at least equal to the said reflection time and therein being an intercorrelation function of a series of transmission instants of all the sources and a series of transmission instants of any one of the sources to give a relationship between the maximum peak amplitude and the secondary residue amplitude greater than a predetermined value and grouping the recorded traces corresponding to the same reflection point, adjusting the traces in relation to the associated source providing the information relating to the reflection point and adding together the adjusted traces relating to the same reflection point.

Barbier, M.G.; Staron, P.J.

1982-02-16

158

Methods for investigating supersonic ground effect in a blowdown wind tunnel  

Microsoft Academic Search

Two methods to experimentally investigate supersonic ground effect problems in a wind tunnel have been examined to determine\\u000a their relative effectiveness compared to a more realistic, but physically unfeasible, representation of the ground effect\\u000a by means of a moving ground. Experimental data were compared with the results of numerical simulations. The latter, once validated\\u000a against pressure data from the wind

G. C. Doig; T. J. Barber; E. Leonardi; A. J. Neely; H. Kleine

2008-01-01

159

Autonomous and Remote-Controlled Airborne and Ground-Based Robotic Platforms for Adaptive Geophysical Surveying  

NASA Astrophysics Data System (ADS)

Low-cost autonomous and remote-controlled robotic platforms have opened the door to precision-guided geophysical surveying. Over the past two years, the U.S. Geological Survey, Senseta, NASA Ames Research Center, and Carnegie Mellon University Silicon Valley, have developed and deployed small autonomous and remotely controlled vehicles for geophysical investigations. The purpose of this line of investigation is to 1) increase the analytical capability, resolution, and repeatability, and 2) decrease the time, and potentially the cost and map-power necessary to conduct near-surface geophysical surveys. Current technology has advanced to the point where vehicles can perform geophysical surveys autonomously, freeing the geoscientist to process and analyze the incoming data in near-real time. This has enabled geoscientists to monitor survey parameters; process, analyze and interpret the incoming data; and test geophysical models in the same field session. This new approach, termed adaptive surveying, provides the geoscientist with choices of how the remainder of the survey should be conducted. Autonomous vehicles follow pre-programmed survey paths, which can be utilized to easily repeat surveys on the same path over large areas without the operator fatigue and error that plague man-powered surveys. While initial deployments with autonomous systems required a larger field crew than a man-powered survey, over time operational experience costs and man power requirements will decrease. Using a low-cost, commercially available chassis as the base for autonomous surveying robotic systems promise to provide higher precision and efficiency than human-powered techniques. An experimental survey successfully demonstrated the adaptive techniques described. A magnetic sensor was mounted on a small rover, which autonomously drove a prescribed course designed to provide an overview of the study area. Magnetic data was relayed to the base station periodically, processed and gridded. A target was located in the subsurface, and a second, higher-resolution survey was programmed and executed to give detailed data over the newly-found target.

Spritzer, J. M.; Phelps, G. A.

2011-12-01

160

Monitoring gray wolf populations using multiple survey methods  

USGS Publications Warehouse

The behavioral patterns and large territories of large carnivores make them challenging to monitor. Occupancy modeling provides a framework for monitoring population dynamics and distribution of territorial carnivores. We combined data from hunter surveys, howling and sign surveys conducted at predicted wolf rendezvous sites, and locations of radiocollared wolves to model occupancy and estimate the number of gray wolf (Canis lupus) packs and individuals in Idaho during 2009 and 2010. We explicitly accounted for potential misidentification of occupied cells (i.e., false positives) using an extension of the multi-state occupancy framework. We found agreement between model predictions and distribution and estimates of number of wolf packs and individual wolves reported by Idaho Department of Fish and Game and Nez Perce Tribe from intensive radiotelemetry-based monitoring. Estimates of individual wolves from occupancy models that excluded data from radiocollared wolves were within an average of 12.0% (SD?=?6.0) of existing statewide minimum counts. Models using only hunter survey data generally estimated the lowest abundance, whereas models using all data generally provided the highest estimates of abundance, although only marginally higher. Precision across approaches ranged from 14% to 28% of mean estimates and models that used all data streams generally provided the most precise estimates. We demonstrated that an occupancy model based on different survey methods can yield estimates of the number and distribution of wolf packs and individual wolf abundance with reasonable measures of precision. Assumptions of the approach including that average territory size is known, average pack size is known, and territories do not overlap, must be evaluated periodically using independent field data to ensure occupancy estimates remain reliable. Use of multiple survey methods helps to ensure that occupancy estimates are robust to weaknesses or changes in any 1 survey method. Occupancy modeling may be useful for standardizing estimates across large landscapes, even if survey methods differ across regions, allowing for inferences about broad-scale population dynamics of wolves.

Ausband, David E.; Rich, Lindsey N.; Glenn, Elizabeth M.; Mitchell, Michael S.; Zager, Pete; Miller, David A.; Waits, Lisette P.; Ackerman, Bruce B.; Mack, Curt M.

2013-01-01

161

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

162

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

163

A survey on statistical methods for health care fraud detection.  

PubMed

Fraud and abuse have led to significant additional expense in the health care system of the United States. This paper aims to provide a comprehensive survey of the statistical methods applied to health care fraud detection, with focuses on classifying fraudulent behaviors, identifying the major sources and characteristics of the data based on which fraud detection has been conducted, discussing the key steps in data preprocessing, as well as summarizing, categorizing, and comparing statistical fraud detection methods. Based on this survey, some discussion is provided about what has been lacking or under-addressed in the existing research, with the purpose of pinpointing some future research directions. PMID:18826005

Li, Jing; Huang, Kuei-Ying; Jin, Jionghua; Shi, Jianjun

2008-09-01

164

A Ground Truthing Method for AVIRIS Overflights Using Canopy Absorption Spectra  

NASA Technical Reports Server (NTRS)

Remote sensing for ecological field studies requires ground truthing for accurate interpretation of remote imagery. However, traditional vegetation sampling methods are time consuming and hard to relate to the scale of an AVIRIS scene. The large errors associated with manual field sampling, the contrasting formats of remote and ground data, and problems with coregistration of field sites with AVIRIS pixels can lead to difficulties in interpreting AVIRIS data. As part of a larger study of fire risk in the Santa Monica Mountains of southern California, we explored a ground-based optical method of sampling vegetation using spectrometers mounted both above and below vegetation canopies. The goal was to use optical methods to provide a rapid, consistent, and objective means of "ground truthing" that could be related both to AVIRIS imagery and to conventional ground sampling (e.g., plot harvests and pigment assays).

Gamon, John A.; Serrano, Lydia; Roberts, Dar A.; Ustin, Susan L.

1996-01-01

165

Evaluation of field sampling and preservation methods for strontium-90 in ground water at the Idaho National Engineering Laboratory, Idaho  

SciTech Connect

From 1952 to 1988, about 140 curies of strontium-90 have been discharged in liquid waste to disposal ponds and wells at the INEL (Idaho National Engineering Laboratory). The US Geological Survey routinely samples ground water from the Snake River Plain aquifer and from discontinuous perched-water zones for selected radionuclides, major and minor ions, and chemical and physical characteristics. Water samples for strontium-90 analyses collected in the field are unfiltered and preserved to an approximate 2-percent solution with reagent-grade hydrochloric acid. Water from four wells completed in the Snake River Plain aquifer was sampled as part of the US Geological Survey's quality-assurance program to evaluate the effect of filtration and preservation methods on strontium-90 concentrations in ground water at the INEL. The wells were selected for sampling on the basis of historical concentrations of strontium-90 in ground water. Water from each well was filtered through either a 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 set of water samples was preserved in the field to an approximate 2-percent solution with reagent-grade hydrochloric acid and the other set of samples was not acidified. 13 refs., 2 figs., 6 tabs.

Cecil, L.D.; Knobel, L.L.; Wegner, S.J. (Geological Survey, Idaho Falls, ID (USA)); Moore, L.L. (USDOE, Washington, DC (USA))

1989-09-01

166

Wind Turbine Farm Network Grounding Design Using Integrated Simulation Methods and Techniques  

Microsoft Academic Search

The design of a wind farm grounding system including the substation and wind turbine generators of the collector network is a very comprehensive task. Powerful integrated grounding simulation methods and design techniques that are appropriate for carrying out this kind of work are presented and discussed in this paper. They include soil structure model selection based on in-situ soil resistivity

J. Liu; F. P. Dawalibi

2010-01-01

167

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

168

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

169

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

170

A Fast Reduction Method of Survey Data in Radio Astronomy  

NASA Astrophysics Data System (ADS)

We present a fast reduction method of survey data obtained using a single-dish radio telescope. Along with a brief review of classical method, a new method of identification and elimination of negative and positive bad channels are introduced using cloud identification code and several IRAF(Image Reduction and Analysis Facility) tasks relating statistics. Removing of several ripple patterns using Fourier Transform is also discussed. It is found that BACKGROUND task within IRAF is very efficient for fitting and subtraction of baseline with varying functions. Cloud identification method along with the possibility of its application for analysis of cloud structure is described, and future data reduction method is discussed.

Lee, Youngung

2001-04-01

171

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

172

A Survey of Fault Detection, Isolation, and Reconfiguration Methods  

Microsoft Academic Search

Fault detection, isolation, and reconfiguration (FDIR) is an important and challenging problem in many engineering applications and continues to be an active area of research in the control community. This paper presents a survey of the various model-based FDIR methods developed in the last decade. In the paper, the FDIR problem is divided into the fault detection and isolation (FDI)

Inseok Hwang; Sungwan Kim; Youdan Kim; Chze Eng Seah

2010-01-01

173

Current methods for stallion semen cryopreservation: A survey  

Microsoft Academic Search

Various factors affect the success of AI with frozen-thawed semen in horses. Stallion variability is thought to be one of the major factors, but semen processing and evaluation techniques, thawing protocols, packaging systems and timing of insemination are far from standardized among laboratories.Our objective was to survey current methods for stallion semen cryopreservation used commercially around the world. From the

J. C Samper; C. A Morris

1998-01-01

174

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

175

Calculation of foundation response to spatially varying ground motion by finite element method.  

National Technical Information Service (NTIS)

This paper presents a general method to compute the response of a rigid foundation of arbitrary shape resting on a homogeneous or multilayered elastic soil when subjected to a spatially varying ground motion. The foundation response is calculated from the...

F. Wang F. Gantenbein

1995-01-01

176

Urban archaeological investigations using surface 3D Ground Penetrating Radar and Electrical Resistivity Tomography methods  

NASA Astrophysics Data System (ADS)

Ongoing and extensive urbanisation, which is frequently accompanied with careless construction works, may threaten important archaeological structures that are still buried in the urban areas. Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods are most promising alternatives for resolving buried archaeological structures in urban territories. In this work, three case studies are presented, each of which involves an integrated geophysical survey employing the surface three-dimensional (3D) ERT and GPR techniques, in order to archaeologically characterise the investigated areas. The test field sites are located at the historical centres of two of the most populated cities of the island of Crete, in Greece. The ERT and GPR data were collected along a dense network of parallel profiles. The subsurface resistivity structure was reconstructed by processing the apparent resistivity data with a 3D inversion algorithm. The GPR sections were processed with a systematic way, applying specific filters to the data in order to enhance their information content. Finally, horizontal depth slices representing the 3D variation of the physical properties were created. The GPR and ERT images significantly contributed in reconstructing the complex subsurface properties in these urban areas. Strong GPR reflections and high-resistivity anomalies were correlated with possible archaeological structures. Subsequent excavations in specific places at both sites verified the geophysical results. The specific case studies demonstrated the applicability of ERT and GPR techniques during the design and construction stages of urban infrastructure works, indicating areas of archaeological significance and guiding archaeological excavations before construction work.

Papadopoulos, Nikos; Sarris, Apostolos; Yi, Myeong-Jong; Kim, Jung-Ho

2009-02-01

177

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

178

A method for correcting the satellite camera position by referencing space photographs to a ground map  

Microsoft Academic Search

A method for highly accurate estimation of the geometry of photographing from space (the coordinates of the principal point\\u000a and the camera orientation), with the use of ground reference points is proposed and experimentally tested. The method is\\u000a based on the matching of projective and geographic coordinates of given landmarks on space photos and ground digital maps.\\u000a A precise estimate

G. I. Peretyagin

2006-01-01

179

Disorientation training in FAA-certificated flight and ground schools: a survey.  

PubMed

A 10-item, voluntary questionnaire answered by 674 flight and ground schools provided information on 1) the conduct of formal instruction about disorientation, 2) the occurrence and content of lectures on disorientation, 3) use of on-the-ground demonstrations of disorientation, 4) use of in-the-air demonstrations of disorientation, 5) use of films on pilot vertigo, 6) amount of instrument flying training students receive, 7) amount of instrument flying training required of flight instructors to maintain their proficiency, 8) adequacy of the schools' programs on disorientation training, 9) other comments, and 10) numerical data regarding the number of students beginning and completing various flight and/or ground school courses. More than one-third of the respondents evaluated their disorientation training program as inadequate and defined the inadequacy most often as a lack of appropriate materials, aids, and information. Tabulations of responses to the separate items suggested areas for improvement in disorientation training. Recommendations were made. PMID:678244

Collins, W E; Hasbrook, A H; Lennon, A O; Gay, D J

1978-08-01

180

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

181

Verifying the Computational Method of Transient Performance with Respect to Grounding Systems based on the FD-TD Method  

NASA Astrophysics Data System (ADS)

Lightning strikes on bulk transmission lines and distribution lines frequently cause serious accidents involving electrical apparatus. It is strongly desired to analyze transient performance in terms of the transient electric potential, transient current, and transient grounding resistance of grounding systems of electrical apparatus in order to establish accident prevention. The transmission line approach, which was brought to practical applicability by Sunde and the electromagnetic field approach based on the method of moments have been conventionally used to analyze the transient performance, however, both are insufficient in general practical usage because the former can only deal with TEM waves and the latter can only analyze grounding systems in homogeneous earth. Hence, one of the authors has already proposed a novel method for computational analysis of transient performance based on the finite-difference time-domain, (FD-TD) method (FD-TD CMTP).This paper presents both experimental results of transient performance with respect to a grounding electrode of a rectangular parallelepiped electrode, which is a model of a foot of the transmission towers, and a square loop electrode, which is an element of a grounding grid, and the calculated results obtained using FD-TD CMTP. The calculated results agree very well with experimental results. This confirms the validity of using FD-TD CMTP to analyze transient performance of grounding systems of electrical apparatus.The FD-TD CMTP is expected to facilitate the rational design of grounding systems.

Tanabe, Kazuo; Asakawa, Akira; Sakae, Maki; Wada, Masaru; Sugimoto, Hitoshi

182

Effect of antioxidant application methods on the color, lipid oxidation, and volatiles of irradiated ground beef.  

PubMed

Four antioxidant treatments (none, 0.05% ascorbic acid, 0.01%alpha-tocopherol + 0.01% sesamol, and 0.05% ascorbic acid + 0.01%alpha-tocopherol + 0.01% sesamol) were applied to ground beef using either mixing or spraying method. The meat samples were placed on Styrofoam trays, irradiated at 0 or 2.5 kGy, and then stored for 7 d at 4 degrees C. Color, lipid oxidation, volatiles, oxidation-reduction potential (ORP), and carbon monoxide (CO) production were determined at 0, 3, and 7 d of storage. Irradiation increased lipid oxidation of ground beef with control and ascorbic acid treatments after 3 d of storage. alpha-Tocopherol + sesamol and ascorbic acid +alpha-tocopherol + sesamol treatments were effective in slowing down lipid oxidation in ground beef during storage regardless of application methods, but mixing was better than the spraying method. Irradiation lowered L*-value and a*-value of ground beef. Storage had no effect on lightness but redness decreased with storage. Ascorbic acid was the most effective in maintaining redness of ground beef followed by ascorbic acid +alpha-tocopherol + sesamol. Irradiation and storage reduced the b*-value of ground beef. Irradiation lowered ORP of ground beef regardless of antioxidants application methods, but ORP was lower in beef with mixing than spraying method. Beef sprayed with antioxidants produced more hydrocarbons and alcohols than the mixing application, but ascorbic acid +alpha-tocopherol + sesamol treatment was effective in reducing the amount of volatiles produced by irradiation. Therefore, mixing was better than the spraying method in preventing lipid oxidation and maintaining color of irradiated ground beef. PMID:19200082

Ismail, H A; Lee, E J; Ko, K Y; Paik, H D; Ahn, D U

2009-01-01

183

A survey of charge-balance errors on published analyses of potable ground and surface waters  

Microsoft Academic Search

Although the charge balance for a single chemical analysis of a water's electrolytes is not a reliable gauge for the accuracy of that analysis, the percent charge-balance error (%CBE) becomes more credible as a means for evaluating analytical technique when applied to groups of analyses. Just how good are charge balances for chemical analyses of potable ground and stream waters

Fritz

2009-01-01

184

Radiological decontamination, survey, and statistical release method for vehicles  

SciTech Connect

Earth-moving vehicles (e.g., dump trucks, belly dumps) commonly haul radiologically contaminated materials from a site being remediated to a disposal site. Traditionally, each vehicle must be surveyed before being released. The logistical difficulties of implementing the traditional approach on a large scale demand that an alternative be devised. A statistical method for assessing product quality from a continuous process was adapted to the vehicle decontamination process. This method produced a sampling scheme that automatically compensates and accommodates fluctuating batch sizes and changing conditions without the need to modify or rectify the sampling scheme in the field. Vehicles are randomly selected (sampled) upon completion of the decontamination process to be surveyed for residual radioactive surface contamination. The frequency of sampling is based on the expected number of vehicles passing through the decontamination process in a given period and the confidence level desired. This process has been successfully used for 1 year at the former uranium millsite in Monticello, Utah (a cleanup site regulated under the Comprehensive Environmental Response, Compensation, and Liability Act). The method forces improvement in the quality of the decontamination process and results in a lower likelihood that vehicles exceeding the surface contamination standards are offered for survey. Implementation of this statistical sampling method on Monticello projects has resulted in more efficient processing of vehicles through decontamination and radiological release, saved hundreds of hours of processing time, provided a high level of confidence that release limits are met, and improved the radiological cleanliness of vehicles leaving the controlled site.

Goodwill, M.E.; Lively, J.W.; Morris, R.L.

1996-06-01

185

Parallel Octree-Based Finite Element Method for Large-Scale Earthquake Ground Motion Simulation  

Microsoft Academic Search

We present a parallel octree-based finite el- ement method for large-scale earthquake ground motion simulation in realistic basins. The octree representa- tion combines the low memory per node and good cache performance of finite difference methods with the spa- tial adaptivity to local seismic wavelengths characteris- tic of unstructured finite element methods. Several tests are provided to verify the numerical

J. Bielak; O. Ghattas; E.-J. Kim

2005-01-01

186

Retina Lesion and Microaneurysm Segmentation using Morphological Reconstruction Methods with Ground-Truth Data  

SciTech Connect

In this work we report on a method for lesion segmentation based on the morphological reconstruction methods of Sbeh et. al. We adapt the method to include segmentation of dark lesions with a given vasculature segmentation. The segmentation is performed at a variety of scales determined using ground-truth data. Since the method tends to over-segment imagery, ground-truth data was used to create post-processing filters to separate nuisance blobs from true lesions. A sensitivity and specificity of 90% of classification of blobs into nuisance and actual lesion was achieved on two data sets of 86 images and 1296 images.

Karnowski, Thomas Paul [ORNL; Govindaswamy, Priya [Oak Ridge National Laboratory (ORNL); Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK); Abramoff, M.D. [University of Iowa

2008-01-01

187

Retina Lesion and Microaneurysm Segmentation using Morphological Reconstruction Methods with Ground-Truth Data  

SciTech Connect

In this work we report on a method for lesion segmentation based on the morphological reconstruction methods of Sbeh et. al. We adapt the method to include segmentation of dark lesions with a given vasculature segmentation. The segmentation is performed at a variety of scales determined using ground-truth data. Since the method tends to over-segment imagery, ground-truth data was used to create post-processing filters to separate nuisance blobs from true lesions. A sensitivity and specificity of 90% of classification of blobs into nuisance and actual lesion was achieved on two data sets of 86 images and 1296 images.

Karnowski, Thomas Paul [ORNL; Tobin Jr, Kenneth William [ORNL; Chaum, Edward [ORNL; Muthusamy Govindasamy, Vijaya Priya [ORNL

2009-09-01

188

System and method for large scale survey analysis  

US Patent & Trademark Office Database

Disclosed herein is a method of analyzing large scale survey results comprising obtaining a sparse data set representing a subset of an original data set comprising a plurality of individuals' responses to a plurality of questions, wherein the sparse data set comprises less than ninety percent of the responses in the original data set; analyzing the sparse data set using a general diagnostic model; and obtaining estimated person parameters using the general diagnostic model.

2011-08-23

189

Soil Surveys  

NASA Technical Reports Server (NTRS)

An accurate method of surveying the soil was developed by NASA and the Department of Agriculture. The method involves using ground penetrating radar to produce subsurface graphs. By examining printouts from the system's recorder, scientists can determine whether a site is appropriate for building, etc.

1985-01-01

190

Preliminary survey of ground-water resources for Island County, Washington  

USGS Publications Warehouse

Increased ground-water withdrawals associated with the population increase in Island County have caused concern about ground-water availability and potential seawater intrusion. The most widespread and widely used aquifer lies near sea level. Locally, available data also indicate that one or more water-bearing zones lie above the sea-level aquifer. Pumpage in 1979 totaled about 1.67 billion gallons; about 90% was pumped from the sea-level aquifer. Most large producing wells in the county have pumping water levels near or below sea level, so that if pumping continued for a long enough time, seawater intrusion would result. Sampling of chloride concentrations in July 1978, April 1980, and August 1980 indicated problem areas mainly in northeastern and southern Camano Island and in central Whidbey Island. (USGS)

Cline, D. R.; Jones, M. A.; Dion, N. P.; Whiteman, K. J.; Sapik, D. B.

1982-01-01

191

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

192

FIELD DEMONSTRATION OF ON-SITE ANALYTICAL METHODS FOR TNT AND RDX IN GROUND WATER  

Microsoft Academic Search

A field demonstration was conducted to assess the performance of eight commercially-available and emerging colorimetric, immunoassay, and biosensor on-site analytical methods for explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in ground water and leachate at the Umatilla Army Depot Activity, Hermiston, Oregon and U.S. Naval Submarine Base, Bangor, Washington, Superfund sites. Ground water samples were analyzed by each of the on-site

Harry Craig; George Ferguson; Anne W. Kusterbeck; L. Shriver-Lake; Thomas Jenkins

2009-01-01

193

A QUESTIONARY SURVEY ON THE CHOICE OF EARTHQUAKE MOTION DETERMINATION METHOD FOR ROAD EMBANKMENTS  

NASA Astrophysics Data System (ADS)

The method to determine the input strong ground motion is a key factor in the seismic performance assessment of road embankments. However, the procedure to choose the method is dependent on the experience and capability of the engineers. In this study, a questionnaire survey to 83 researchers and engineers of the earthquake engineering field in Japan is conducted to reveal their recognition on the features for various earthquake motion determination method. The procedure to conduct microtremor measurement for input strong motion determination and zoning judgement based on H/V spectrum obtained by microtremor measurements are also investigated. The results of the questionnaire are useful for a reference in practical earthquake motion determination for road embankments.

Ichii, Koji; Hata, Yoshiya; Murata, Akira

194

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

195

Seasonal changes in groundwater storage estimated by absolute ground gravity and MRS surveys in West Africa  

Microsoft Academic Search

Important and fast groundwater storage changes occur in tropical monsoon regions in response to seasonal rainfall and subsequent surface water redistribution. In West Africa, one main goal of the GHYRAF experiment (Gravity and Hydrology in Africa, 2008-2010) is to compare absolute gravimetric measurements with dense hydrological surveys to better estimate and model water storage changes at various time scales. Magnetic

G. Favreau; M. Boucher; B. Luck; J. Pfeffer; P. Genthon; J. Hinderer

2009-01-01

196

Aerial Surveys for Cetaceans in the Former Akutan, Alaska, Whaling Grounds  

Microsoft Academic Search

Randomized aerial surveys were flown between 26 July and 26 August 1984 to search for cetaceans in two areas of southwestern Alaska: one on both Bering Sea and Pacific Ocean sides of the Aleutian Islands near the defunct Akutan shore-whaling station, which operated from 191 2 through 1939, the other overlapping continental slope and shallow continental shelf waters between the

B. S. STEWART; S. A. KARL; P. K. YOCHEM; S. LEATHERWOOD; J. L. LAAKE

1987-01-01

197

Health Survey Research Methods: Proceedings of the Conference on Health Survey Research Methods (4th) Held at Washington, DC. on May 2-5, 1982.  

National Technical Information Service (NTIS)

This conference report is intended to inform the health research community about recent advances in health survey methods, about continuing concerns of which health survey users should be aware, and about areas requiring further methodological research. T...

C. F. Cannell R. M. Groves

1982-01-01

198

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.

edited by Mattraw, Harold C., Jr.; Franks, Bernard J.

1986-01-01

199

A Forest Biomass Survey by Bitterlich Method With an Electronic Relascope for Satellite Data Validation  

NASA Astrophysics Data System (ADS)

For the better understanding of the carbon cycle in the global ecosystem, an investigation on the spatio- temporal variation of the carbon stock which is stored as vegetation biomass should be important. "PALSAR (Phased Array type L-band Synthetic Aperture Radar)", an onboard sensor of the polar orbiting satellite "ALOS (Advanced Land Observing Satellite)" launched in January 2006, provides the information which can be used for the above-ground biomass estimation. It is expected that ALOS/PALSAR provides us a great opportunity to analyze the biomass dynamics over extensive regions. To derive the biomass from the ALOS/PALSAR measurement, it is inevitable to acquire in situ biomass measurement by ground-based forest surveys. Moreover, it is required to obtain such ground-based information at as possible many sites, because the region targeted by satellite remote sensing is extensive and the forest structure in that region is various. Therefore, a quick forest survey will be required to measure the biomass at as possible many sites. For the quick measurement of the forest above-ground biomass, we propose a way that is a combination of Bitterlich angle count sampling method and sampled-tree measuring method. First, a tree which has wider trunk than the basal area factor (BAF) angle is identified by the relascope from a representative point in the target forest. Next, the tree height and the breast height diameter (DBH) of the sampled tree are measured. The biomass of the tree is estimate by the allometric equation with the tree height and DBH measurements. Through these processes, the biomass density of the sampled tree per the forest area defined by the BAF is estimated. By sampling and measuring all trees (usually around 20 trees), the biomass of the forest can be estimate. A brand-new electronic relascope (Criterion RD 1000, Laser Technology Inc.) and laser range finder (TruPulse 200, Laser Technology Inc.) are used for the tree height and DBH measurements to shorten the time required for measuring. A preliminary forest survey was conducted in a Pinus densiflora forest around Fujiyoshida, Yamanashi, Japan, and examined the adaptability of this way.

Suzuki, R.; Ishii, R.; Takao, G.; Nakano, T.; Yasuda, T.

2006-12-01

200

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

201

A simplified analysis method for piled raft foundations subjected to ground movements induced by tunnelling  

Microsoft Academic Search

A simplified method of numerical analysis has been developed to estimate the deformation and load distribution of piled raft foundations subjected to ground movements induced by tunnelling and incorporated into a computer program PRAB. In this method, a hybrid model is employed in which the flexible raft is modelled as thin plates, the piles as elastic beams, and the soil

Pastsakorn Kitiyodom; Tatsunori Matsumoto; Kanji Kawaguchi

2005-01-01

202

Ground and marine magnetic surveys of the lower eastern flank of Etna volcano (Italy)  

NASA Astrophysics Data System (ADS)

In 1996 and 1997, two high-resolution magnetic surveys, one on land and the other at sea, were carried out on the lower eastern flank of Mount Etna. The magnetic surveys, covering an area of about 400 km 2, aimed to elucidate the relationships between the main tectonic and morphologic features of this flank of Mount Etna. Major features include widespread NNW- and NNE-trending active faults and the Valle del Bove, a depression considered to be the source area of the Chiancone deposit, the largest Etnean volcaniclastic sequence. Magnetic surveys show anomalies that roughly follow the trend of active main structures. Although few magnetization measurements are available for the most representative outcrops of the lower eastern side of Mount Etna, interpretation of the anomalies defines the underground geometry of the Chiancone deposit and its relationship with volcano stratigraphic units and the underlying sedimentary rocks. In particular, a volume of about 14 km 3 was ascribed to the Chiancone deposit. Such a large amount of material was likely produced by a catastrophic event, and deposited at different periods at the exit of the Valle del Bove in an area produced by the interaction, on a regional scale, of the main tectonic structures affecting this flank of the volcano.

Del Negro, Ciro; Napoli, Rosalba

2002-05-01

203

Pan-European survey on the occurrence of selected polar organic persistent pollutants in ground water.  

PubMed

This study provides the first pan-European reconnaissance of the occurrence of polar organic persistent pollutants in European ground water. In total, 164 individual ground-water samples from 23 European Countries were collected and analysed (among others) for 59 selected organic compounds, comprising pharmaceuticals, antibiotics, pesticides (and their transformation products), perfluorinated acids (PFAs), benzotriazoles, hormones, alkylphenolics (endocrine disrupters), Caffeine, Diethyltoluamide (DEET), and Triclosan. The most relevant compounds in terms of frequency of detection and maximum concentrations detected were DEET (84%; 454 ng/L), Caffeine (83%; 189 ng/L), PFOA (66%; 39 ng/L), Atrazine (56%; 253 ng/L), Desethylatrazine (55%; 487 ng/L), 1H-Benzotriazole (53%; 1032 ng/L), Methylbenzotriazole (52%; 516 ng/L), Desethylterbutylazine (49%; 266 ng/L), PFOS (48%, 135 ng/L), Simazine (43%; 127 ng/L), Carbamazepine (42%; 390 ng/L), nonylphenoxy acetic acid (NPE(1)C) (42%; 11 microg/L), Bisphenol A (40%; 2.3 microg/L), PFHxS (35%; 19 ng/L), Terbutylazine (34%; 716 ng/L), Bentazone (32%; 11 microg/L), Propazine (32%; 25 ng/L), PFHpA (30%; 21 ng/L), 2,4-Dinitrophenol (29%; 122 ng/L), Diuron (29%; 279 ng/L), and Sulfamethoxazole (24%; 38 ng/L). The chemicals which were detected most frequently above the European ground water quality standard for pesticides of 0.1 microg/L were Chloridazon-desphenyl (26 samples), NPE(1)C (20), Bisphenol A (12), Benzotriazole (8), N,N'-Dimethylsulfamid (DMS) (8), Desethylatrazine (6), Nonylphenol (6), Chloridazon-methyldesphenyl (6), Methylbenzotriazole (5), Carbamazepine (4), and Bentazone (4). However, only 1.7% of all single analytical measurements (in total 8000) were above this threshold value of 0.1 microg/L; 7.3% were > than 10 ng/L. PMID:20554303

Loos, Robert; Locoro, Giovanni; Comero, Sara; Contini, Serafino; Schwesig, David; Werres, Friedrich; Balsaa, Peter; Gans, Oliver; Weiss, Stefan; Blaha, Ludek; Bolchi, Monica; Gawlik, Bernd Manfred

2010-07-01

204

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

205

Survey of ground state neutron spectroscopic factors from Li to Cr isotopes  

NASA Astrophysics Data System (ADS)

The success of the Shell Model has prompted many measurements to extract the spectroscopic factors which describe the configuration of single particle orbitals. We have extracted the ground state to ground state neutron spectroscopic factors for 79 nuclei ranging in Z from 3 to 24 by analyzing the past measurements of the angular distributions of (d,p) and (p,d) reactions in a systematic and consistent manner [1]. For the Ca isotopes from ^40Ca to ^48Ca, the spectroscopic factors follow the predictions of the single particle model predictions as well as predictions from shell model suggesting Ca isotopes have good spherical cores with well defined valence nucleons. For the 59 nuclei where modern shell model calculations [Oxbash] are available, with the exception of the deformed F and Ne isotopes, the experimental spectroscopic factors for most nuclei agree with predictions from modern day shell model to within 20%. This work is supported by the NSF Grant No. NSF-PHY-01-10253 and SURE. Reference: [1] X.D.Liu, M.A.Famiano,W.G.Lynch,M.B.Tsang,and J.A.Tostevin, Phys. Rev. C69 (2004) 1.

Lee, Hui-Ching; Tsang, Betty

2005-04-01

206

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

207

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

NASA Astrophysics Data System (ADS)

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 that differences in relation to leadership and decision making were the most important issues thought to interfere with efficient co-working within ESA, and between ESA employees and colleagues from other agencies. Employees who collaborated with more than three nationalities within ESA indicated most challenges in co-working due to differences in compliance, behavioural norms and competitiveness. Challenges in co-working differed between agencies, and these differences were consistent with value differences in the national populations. The results may have applied value for training of European employees working in international space program teams.

Sandal, Gro Mjeldheim; Manzey, Dietrich

208

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

209

Survey of predators and sampling method comparison in sweet corn.  

PubMed

Natural predation is an important component of integrated pest management that is often overlooked because it is difficult to quantify and perceived to be unreliable. To begin incorporating natural predation into sweet corn, Zea mays L., pest management, a predator survey was conducted and then three sampling methods were compared for their ability to accurately monitor the most abundant predators. A predator survey on sweet corn foliage in New York between 1999 and 2001 identified 13 species. Orius insidiosus (Say), Coleomegilla maculata (De Geer), and Harmonia axyridis (Pallas) were the most numerous predators in all years. To determine the best method for sampling adult and immature stages of these predators, comparisons were made among nondestructive field counts, destructive counts, and yellow sticky cards. Field counts were correlated with destructive counts for all populations, but field counts of small insects were biased. Sticky cards underrepresented immature populations. Yellow sticky cards were more attractive to C. maculata adults than H. axyridis adults, especially before pollen shed, making coccinellid population estimates based on sticky cards unreliable. Field counts were the most precise method for monitoring adult and immature stages of the three major predators. Future research on predicting predation of pests in sweet corn should be based on field counts of predators because these counts are accurate, have no associated supply costs, and can be made quickly. PMID:14998137

Musser, Fred R; Nyrop, Jan P; Shelton, Anthony M

2004-02-01

210

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

211

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

212

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

213

Microfilaria survey methods and analysis of survey data in filariasis control programmes  

PubMed Central

Based on studies carried out by the author and his associates in areas of Japan and South Asia where malayan and bancroftian filariasis is endemic, this paper recommends methods for use in microfilaria surveys and in the analysis of data obtained in such surveys. The author recommends the use of measured blood samples of 30 mm3, with which 3 linear smears are made on slides. The blood films are then stained with azure II and eosin. Microfilarial counts made with such smears are, it is claimed, simpler, less expensive, and more reliable than those made with round, thick smears. Furthermore, the use of 3 smears from each person permits the calculation of correction factors, by means of which the detection rates that would be obtained by the use of different volumes of blood may be calculated. Information obtained by the use of this method has proved to be of great use in epidemiological studies of filariasis in endemic areas, in comparing the prevalence of the disease in different populations, and in evaluating the results of control measures. Different ways of recording and classifying the results are described, and the frequency distribution of microfilarial densities is analysed.

Sasa, Manabu

1967-01-01

214

Retirement on grounds of ill health: cross sectional survey in six organisations in United Kingdom.  

PubMed Central

OBJECTIVE: To assess the process and outcome of retirement due to ill health in six large organisations. DESIGN: Cross sectional study of the rate of retirement due to ill health by age, sex, and length of service. Principal diagnoses by age and length of service were also compared. SETTING: Four public and two private large employers in the United Kingdom. MAIN OUTCOME MEASURES: Rates of retirement on the grounds of ill health by age, sex, and length of service of employees contributing to pension schemes. RESULTS: Rates of ill health retirement varied from 20 to 250 per 10,000 contributing members, and in two organisations the rate varied geographically within the same organisation. In the two organisations that provided data by sex, women retired at a greater rate than men under age 40 and over age 50. In four organisations the modal age or length of service coincided with enhancements in benefits. In the four that provided information on diagnoses, musculoskeletal and minor psychiatric illnesses were the most common reasons for retirement. CONCLUSION: The granting of ill health retirement benefits may not be determined by illness. There is a need for some employers and pension schemes to improve their processes for granting benefits. Doctors should be wary of conflicts of interest and work to guidelines when they advise pension schemes about the merits of an application for benefits.

Poole, C. J.

1997-01-01

215

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

216

Urban archaeological investigations using surface 3D Ground Penetrating Radar and Electrical Resistivity Tomography methods  

Microsoft Academic Search

Ongoing and extensive urbanisation, which is frequently accompanied with careless construction works, may threaten important archaeological structures that are still buried in the urban areas. Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods are most promising alternatives for resolving buried archaeological structures in urban territories. In this work, three case studies are presented, each of which involves an

Nikos Papadopoulos; Apostolos Sarris; Myeong-Jong Yi; Jung-Ho Kim

2009-01-01

217

A simplified analysis method for piled raft foundations subjected to ground movements induced by tunnelling  

NASA Astrophysics Data System (ADS)

A simplified method of numerical analysis has been developed to estimate the deformation and load distribution of piled raft foundations subjected to ground movements induced by tunnelling and incorporated into a computer program PRAB. In this method, a hybrid model is employed in which the flexible raft is modelled as thin plates, the piles as elastic beams, and the soil is treated as interactive springs. The interactions between structural members, pile-soil-pile, pile-soil-raft and raft-soil-raft interactions, are modelled based on Mindlin's solutions for both vertical and lateral forces. The validity of the proposed method is verified through comparisons with some published solutions for single piles and pile groups subjected to ground movements induced by tunnelling. Thereafter, the solutions from this approach for the analysis of a pile group and a piled raft subjected to ground movements induced by tunnelling are compared with those from three-dimensional finite difference program. Good agreements between these solutions are demonstrated. The method is then used for a parametric study of single piles, pile groups and piled rafts subjected to ground movements induced by tunnelling. Copyright

Kitiyodom, Pastsakorn; Matsumoto, Tatsunori; Kawaguchi, Kanji

2005-12-01

218

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...

219

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

220

A Ground-Based Mid-Infrared Imaging Survey of Embedded Young Stellar Objects in the Rho Ophiuchi Cloud Core  

NASA Astrophysics Data System (ADS)

Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the ? Ophiuchi cloud are presented. Data were acquired at the Palomar 5-m and at the Keck 10-m telescopes with the MIRLIN and LWS instruments, at 0.5'' and 0.25'' resolutions, respectively. Of 172 survey objects, 85 were detected. A plot of the frequency distribution of the detected objects with SED spectral slope shows that YSOs spend ˜ 3 × 105 yr in the Flat Spectrum phase, clearing out their remnant infall envelopes. Mid-infrared variability is found among a significant fraction of the surveyed objects and is found to occur for all SED classes with optically thick disks. Large amplitude near-infrared variability, also found for all SED classes with optically thick disks, seems to occur with somewhat higher frequency at the earlier evolutionary stages. The highly variable value of K-band veiling that a single source can exhibit in any of the SED classes in which active disk accretion can take place is striking, and is direct observational evidence for highly time-variable accretion activity in disks. Finallly, by comparing mid-infrared vs. near-infrared excesses in a subsample with well-determined effective temperatures and extinction values, disk clearing mechanisms are explored. Financial support for this project through NSF grants AST 00-96087 (CAREER), AST 97-53229 (POWRE), and AST 02-06146 is gratefully acknowledged. MB further thanks the NASA/ASEE Summer Faculty Fellowship program at JPL, that made this work possible.

Barsony, M.; Ressler, M. E.; Marsh, K. A.

2004-12-01

221

Flowmeter and Ground Penetrating Radar: comparison between hydrogeological and geophysical methods  

NASA Astrophysics Data System (ADS)

A comparison between saturated hydraulic conductivity calculated with Electromagnetic Borehole Flowmeter (EBF) and water content obtained by Ground Penetrating Radar (GPR) Zero Offset Profile (ZOP) is presented. EBF technique permits to obtain permeability profiles along one borehole in the saturated zone by using the Moltz (1993) method. The analysis of ZOP data provides information about the water content (Topp, 1980) in the section between two adjacent boreholes. Water content profiles in the saturated zone can be related to the porosity of the medium which, together with the permeability from EBF measurements, is fundamental for any hydrogeological characterization. These two methods have been applied to three different test-sites located in the Northern Italy. A first site regards a complex aquifer, characterized by a chaotic sequence of gypsum-marls. The other two sites are characterized by an alternation of sandy and silty-sandy layers. For each site, we adopted the EBF along screened boreholes with 0.25 m spacing, under ambient and stressed conditions. The cross-hole georadar survey was performed within the saturated zone by using 100 Hz borehole antennas with 0.25 m spacing. The results from the analysis of EBF and ZOP profiles show a general positive correlation between permeability and water content and porosity. This is reasonable for granular soils where the permeability is controlled by the pore space available for water flow, i.e., the effective porosity. For this soils, where EBF permeability and ZOP water-content profiles are in good agreement, the volume between the boreholes can be supposed to be homogeneous. On the other hand, a poor correlation suggests the presence of heterogeneity between the boreholes, which can be observed because the two techniques involve different volumes of soil: the EBF permeability refers to a portion of volume just around the borehole while the ZOP investigates the entire volume between the two boreholes. The poor correlation could be enhanced when enlarging the borehole separation, because the difference in the involved volume between the two techniques increases. Finally, the degree of correlation between the EBF permeability profile and the ZOP water content profile can indicate how much the volume investigated by EBF is effectively representative of the entire volume between the boreholes. Molz, F.J. and S.C. Young, 1993. Development and Application of Borehole Flowmeters for Environmental Assessment, The Log Analyst, 13-23. Topp G.C., J.L. Davis and A.P. Annan, 1980. Electromagnetic determination of soil water content: measurements in coaxial transmission lines, Water Resources Research, 16, 574-582.

Villa, A.; Basirico', S.; Arato, A.; Crosta, G. B.; Frattini, P.; Godio, A.

2012-04-01

222

A Method for Emphasizing Reflection Waves from Buried Objects by Using Ground-penetrating Radar  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar (GPR) is a useful tool for performing subsurface imaging by using radar pulses. In previous paper, we proposed a method for denoising GPR signals by using 2D Gabor wavelet transforms. In this paper, we present a new method for emphasizing GPR reflected waves from buried objects. We can evaluate the results of the time-frequency analysis of the reflection waves on the basis of the Markov Chain Monte Carlo (MCMC) and the Infinite Gaussian Mixture Model (IGMM) methods. Our proposed methods are effective as pre-processing method for detecting the positions of buried metal pipes.

Kobayashi, Makoto; Nakano, Kazushi

223

A Method for Retrieving Ground Flash Fraction from Satellite Lightning Imager Data  

NASA Technical Reports Server (NTRS)

A general theory for retrieving the fraction of ground flashes in N lightning observed by a satellite-based lightning imager is provided. An "exponential model" is applied as a physically reasonable constraint to describe the measured optical parameter distributions, and population statistics (i.e., mean, variance) are invoked to add additional constraints to the retrieval process. The retrieval itself is expressed in terms of a Bayesian inference, and the Maximum A Posteriori (MAP) solution is obtained. The approach is tested by performing simulated retrievals, and retrieval error statistics are provided. The ability to retrieve ground flash fraction has important benefits to the atmospheric chemistry community. For example, using the method to partition the existing satellite global lightning climatology into separate ground and cloud flash climatologies will improve estimates of lightning nitrogen oxides (NOx) production; this in turn will improve both regional air quality and global chemistry/climate model predictions.

Koshak, William J.

2009-01-01

224

Total-variation improved split Bregman method for ground penetrating radar image restoration  

NASA Astrophysics Data System (ADS)

In this paper, an improved data processing procedure is proposed for the purpose of ground penetrating radar (GPR) image restoration. The image processing method is achieved by combining the isotropic and anisotropic total-variation (TV) model of split Bregman, suppressing the staircasing effect and circumventing the edges blurred. Numerical experiments indicate that the proposed approach can well recover edges and most of the details of a (GPR) image. Hence, the proposed method is efficient in (GPR) image restoration.

Wang, Wen-peng; Zhao, Bo; Liu, Xiao-jun; Fang, Guang-you

2013-12-01

225

The effect of survey method on survey participation: Analysis of data from the Health Survey for England 2006 and the Boost Survey for London  

PubMed Central

Background There is a need for local level health data for local government and health bodies, for health surveillance and planning and monitoring of policies and interventions. The Health Survey for England (HSE) is a nationally-representative survey of the English population living in private households, but sub-national analyses can be performed only at a regional level because of sample size. A boost of the HSE was commissioned to address the need for local level data in London but a different mode of data collection was used to maximise participant numbers for a given cost. This study examines the effects on survey and item response of the different survey modes. Methods Household and individual level data are collected in HSE primarily through interviews plus individual measures through a nurse visit. For the London Boost, brief household level data were collected through interviews and individual level data through a longer self-completion questionnaire left by the interviewer and collected later. Sampling and recruitment methods were identical, and both surveys were conducted by the same organisation. There was no nurse visit in the London Boost. Data were analysed to assess the effects of differential response rates, item non-response, and characteristics of respondents. Results Household response rates were higher in the 'Boost' (61%) than 'Core' (HSE participants in London) sample (58%), but the individual response rate was considerably higher in the Core (85%) than Boost (65%). There were few differences in participant characteristics between the Core and Boost samples, with the exception of ethnicity and educational qualifications. Item non-response was similar for both samples, except for educational level. Differences in ethnicity were corrected with non-response weights, but differences in educational qualifications persisted after non-response weights were applied. When item non-response was added to those reporting no qualification, participants' educational levels were similar in the two samples. Conclusion Although household response rates were similar, individual response rates were lower using the London Boost method. This may be due to features of London that are particularly associated with lower response rates for the self-completion element of the Boost method, such as the multi-lingual population. Nevertheless, statistical adjustments can overcome most of the demographic differences for analysis. Care must be taken when designing self-completion questionnaires to minimise item non-response.

2010-01-01

226

Borehole survey method and apparatus for drilling substantially horizontal boreholes  

SciTech Connect

A borehole survey method and apparatus are claimed for use in drilling substantially horizontal boreholes through a mineral deposit wherein a dip accelerometer, a roll accelerometer assembly and a fluxgate are disposed near the drill bit, which is mounted on a bent sub, and connected to a surface computation and display unit by a cable which extends through the drill string. The dip angle of the borehole near the drill bit, the azimuth of the borehole near the drill bit and the roll angle or orientation of the bent sub are measured and selectively displayed at the surface while the drill string is in the borehole for utilization in guiding the drill bit through the mineral deposit along a predetermined path.

Trowsdale, L.S.

1982-11-30

227

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

228

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

NASA Astrophysics Data System (ADS)

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 Network (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, W. J.; Solakiewicz, R.

2013-12-01

229

Efficient numerical methods for computing ground states of spin-1 Bose–Einstein condensates based on their characterizations  

SciTech Connect

In this paper, we propose efficient numerical methods for computing ground states of spin-1 Bose–Einstein condensates (BECs) with/without the Ioffe–Pritchard magnetic field B(x). When B(x)?0, a numerical method is introduced to compute the ground states and it is also applied to study properties of ground states. Numerical results suggest that the densities of m{sub F}=±1 components in ground states are identical for any nonzero B(x). In particular, if B(x)?B?0 is a constant, the ground states satisfy the single-mode approximation. When B(x)?0, efficient and simpler numerical methods are presented to solve the ground states of spin-1 BECs based on their ferromagnetic/antiferromagnetic characterizations. Numerical simulations show that our methods are more efficient than those in the literature. In addition, some conjectures are made from our numerical observations.

Bao, Weizhu, E-mail: mathbaowz@nus.edu.sg [Department of Mathematics and Center for Computational Science and Engineering, National University of Singapore, Singapore 119076 (Singapore)] [Department of Mathematics and Center for Computational Science and Engineering, National University of Singapore, Singapore 119076 (Singapore); Chern, I-Liang, E-mail: chern@math.nctu.edu.tw [Department of Applied Mathematics and Center of Mathematical Modeling and Scientific Computing, National Chiao Tung University, Hsinchu 30010, Taiwan (China) [Department of Applied Mathematics and Center of Mathematical Modeling and Scientific Computing, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Department of Mathematics, National Taiwan University, Taipei 10617, Taiwan (China); Zhang, Yanzhi, E-mail: zhangyanz@mst.edu [Department of Mathematics and Statistics, Missouri University of Science and Technology, Rolla, MO 65409-0020 (United States)] [Department of Mathematics and Statistics, Missouri University of Science and Technology, Rolla, MO 65409-0020 (United States)

2013-11-15

230

First orbit determination with numerical methods based on short arcs acquired in space debris surveys  

NASA Astrophysics Data System (ADS)

Surveys for space debris aim at improving our knowledge of the space debris population. The survey results are fed either into space debris environment models or into orbital element catalogue of space debris objects, depending on whether the objects should be tracked later on. In both cases first orbit determination is a crucial step. The determined orbital elements together with estimated of the magnitude of the object allow first estimates of the object size. The orbital elements are also the central input to validate and improve the space debris environment models. Considering catalogue build-up and maintenance, the results from the first orbit determination set important constraints for the correlation of the new object with the catalogue, the re-acquisition and finally the identification of the object. In the case of space debris surveys first orbits must be determined from very short arcs of observations, which are due to the limits of the current sensor technology, in particular due to the limited field-of-view diameter of the telescopes used for optical surveys. The quality of the first orbits is in any case a function of the measurement accuracy. We present an approach for first orbit determination, which is derived from the boundary value method implemented in the CelMech program system (Beutler, 2005). The approach considers angular measurements, as derived from optical observation systems. The CelMech module ORBDET was generalized to perform a two-dimensional search by systematically varying the topocentric ranges at the boundary epochs of the observed arc. The search aims at identifying local minima of a least-square adjustment of all available observations using a truncated Taylor series to approximate the particular solution of the equation of motion for the debris considered. We apply this method to observations from ongoing space debris surveys of ESA using the 1-m telescope at the Optical Ground Station in Tenerife. Furthermore we apply this approach to a proposed space-based optical observation system. Last, but not least we consider the inclusion of range observations in our algorithm. Beutler G (2005) Methods of Celestial Mechanics. Springer, Berlin, Heidelberg, New York

Flohrer, Tim; Beutler, Gerhard; Schildknecht, Thomas

231

Choosing an appropriate soil-gas survey method.  

PubMed

Three types of soil-gas surveys were performed over the same location at an industrial facility. The surveys performed were (1) a passive technique using buried collectors, (2) an active technique in which samples were collected in the field by pumping with subsequent analysis at a field laboratory, and (3) a screening technique that employed a hand-held survey instrument. Each of the surveys had desirable features, but there was considerable variability in the quality of data obtained, cost, and ease of performance. The passive and active surveys provided excellent detection limits, but the passive technique does not provide data in real time. The active survey was also time-consuming and required an analytical chemist in the field. Neither the active nor the passive survey were able to delineate the plume of contaminated groundwater. Consequently, the results from the rapid and inexpensive reconnaissance technique provided functionally equivalent data. PMID:24234342

Korte, N; Wagner, S; Nyquist, J

1992-04-01

232

FINITE DIFFERENCE METHOD AND ATP\\/EMTP FOR SELECTED EMC PROBLEM IN POWER SYSTEMS: MODELING OF GROUNDING SYSTEMS TRANSIENTS  

Microsoft Academic Search

This paper presents the applications of Finite Difference Method (FDM) and ATP\\/EMTP sofware to the EMC problem of power systems which is transient responses of grounding systems due to the effect of lightning stroke. The results of two methods for the different shapes of grounding systems such as the horizoltal grounding conductors, the square grid of 1x1, 2x2,…are computed and

Vu Phan Tu; Nguyen Nhat Nam; Huynh Quoc Viet

233

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

234

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

235

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

236

Evaluation of field sampling and preservation methods for strontium-90 in ground water at the Idaho National Engineering Laboratory, Idaho.  

National Technical Information Service (NTIS)

From 1952 to 1988, about 140 curies of strontium-90 have been discharged in liquid waste to disposal ponds and wells at the INEL (Idaho National Engineering Laboratory). The US Geological Survey routinely samples ground water from the Snake River Plain aq...

L. D. Cecil L. L. Knobel S. J. Wegner L. L. Moore

1989-01-01

237

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

USGS Publications Warehouse

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. ?? 2007 National Ground Water Association.

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

2007-01-01

238

Occurrence of Selected Radionuclides in Ground Water Used for Drinking Water in the United States: A Reconnaissance Survey, 1998.  

National Technical Information Service (NTIS)

The purpose of this report is to provide information and data that describe concentration distributions of Ra-224 in drinking water from selected ground-water sources nationwide. Radiochemical analyses of raw, untreated ground water from public water-supp...

A. H. Mullin M. J. Focazio T. F. Kraemer T. H. Barringer V. T. dePaul Z. Szabo

1998-01-01

239

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

240

A STUDY OF LIFT-OFF TEST METHOD OF GROUND ANCHORS  

NASA Astrophysics Data System (ADS)

Ground anchors (hereinafter anchors) are important to do the maintenance after construction. Residual tensile strength of anchors are generally confirmed by lift-off test that pulls an anchor using a hydraulic jack. However, the lift-off test has not been established a proper testing method. Therefore, it may not have been proper maintenance from measurement variability. In this paper, we conducted various lift-off test at cut slope of the expressway, and made proposals on proper lift-off test method.

Fujiwara, Yuu; Sakai, Toshinori

241

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

242

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

243

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

Code of Federal Regulations, 2010 CFR

... 2007-07-01 false Ground water source microbial monitoring and analytical...Water Rule § 141.402 Ground water source microbial monitoring and analytical...the first customer for each ground water source; and (ii) The...

2007-07-01

244

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

Code of Federal Regulations, 2010 CFR

... 2008-07-01 false Ground water source microbial monitoring and analytical...Water Rule § 141.402 Ground water source microbial monitoring and analytical...the first customer for each ground water source; and (ii) The...

2008-07-01

245

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

246

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

247

Strong ground motion simulation of the 2003 Bam, Iran, earthquake using the empirical Green's function method  

NASA Astrophysics Data System (ADS)

The 2003 Bam, Iran, earthquake caused catastrophic damage to the city of Bam and neighboring villages. Given its magnitude ( M w ) of 6.5, the damage was remarkably large. Large-amplitude ground motions were recorded at the Bam accelerograph station in the center of Bam city by the Building and Housing Research Center (BHRC) of Iran. We simulated the Bam earthquake acceleration records at three BHRC strong-motion stations—Bam, Abaraq, and Mohammad-Abad—by the empirical Green's function method. Three aftershocks were used as empirical Green's functions. The frequency range of the empirical Green's function simulations was 0.5-10 Hz. The size of the strong motion generation area of the mainshock was estimated to be 11 km in length by 7 km in width. To estimate the parameters of the strong motion generation area, we used 1D and 2D velocity structures across the fault and a combined source model. The empirical Green's function method using a combination of aftershocks produced a source model that reproduced ground motions with the best fit to the observed waveforms. This may be attributed to the existence of two distinct rupture mechanisms in the strong motion generation area. We found that the rupture starting point for which the simulated waveforms best fit the observed ones was near the center of the strong motion generation area, which reproduced near-source ground motions in a broadband frequency range. The estimated strong motion generation area could explain the observed damaging ground motion at the Bam station. This suggests that estimating the source characteristics of the Bam earthquake is very important in understanding the causes of the earthquake damage.

Sadeghi, Hossein; Miyake, Hiroe; Riahi, Ali

2013-04-01

248

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

249

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

250

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.

Liu, Zhao; Wang, Jinling; Liu, Daxue

2013-01-01

251

A simple, low-cost method to monitor duration of ground water pumping.  

PubMed

Monitoring ground water withdrawals for agriculture is a difficult task, while agricultural development leads frequently to overexploitation of the aquifers. To fix the problem, sustainable management is required based on the knowledge of water uses. This paper introduces a simple and inexpensive direct method to determine the duration of pumping of a well by measuring the temperature of its water outlet pipe. A pumping phase is characterized by a steady temperature value close to ground water temperature. The method involves recording the temperature of the outlet pipe and identifying the different stages of pumping. It is based on the use of the low-cost and small-size Thermochron iButton temperature logger and can be applied to any well, provided that a water outlet pipe is accessible. The temperature time series are analyzed to determine the duration of pumping through manual and automatic posttreatments. The method was tested and applied in South India for irrigation wells using electricity-powered pumps. The duration of pumping obtained by the iButton method is fully consistent with the duration of power supply (1.5% difference). PMID:19016895

Massuel, S; Perrin, J; Wajid, M; Mascre, C; Dewandel, B

2009-01-01

252

Methods for Household Travel Surveys. A Synthesis of Highway Practice.  

National Technical Information Service (NTIS)

This synthesis will be of interest to planning, administrative, and traffic officials in state transportation agencies and in metropolitan planning organizations (MPOs); to consultants concerned with the design and conduct of surveys; and to those engaged...

P. R. Stopher H. M. A. Metcalf

1996-01-01

253

Electromagnetic survey of the K1070A burial ground at the Oak Ridge K-25 Site, Oak Ridge, Tennessee. Environmental Restoration Program  

SciTech Connect

The K1070A burial ground, located at the K-25 Site on the Oak Ridge Reservation, received chemical and radioactive wastes from the late 1940s until 1975. Analysis of water samples collected from nearby monitoring wells indicates that contamination is migrating offsite. In November 1991, Oak Ridge National Laboratory (ORNL) personnel collected high-resolution electrical terrain conductivity data at the K1070A burial ground. A Model EM31 terrain conductivity meter manufactured by Geonics Limited was used in conjunction with the ORNL-developed Ultrasonic Ranging and Data System (USRADS) to perform the survey. The purposeof the survey was to provide Environmental Restoration (ER) staff with a detailed map of the spatial variation of the apparent electrical conductivity of the shallow subsurface (upper 3 m) to assist them in siting future monitoring wells closer to the waste area without drilling into the buried waste.

Nyquist, J.E.; Emery, M.S.

1993-01-01

254

Ground penetrating radar (G.P.R.) surveys applied to the research of crypts in San Sebastiano's church in Catania (Sicily)  

Microsoft Academic Search

The aim of the present paper is the identification of natural or anthropic buried cavities under the church of St. Sebastiano in Catania (Sicily). To this purpose Ground Penetrating Radar (G.P.R.) surveys were performed on the pavement of the church and three in situ drillings were carried out outside the church. Through the G.P.R. investigation, the existence of hidden structures

Donatella Barilaro; Caterina Branca; Stefano Gresta; Sebastiano Imposa; Antonio Leone; Domenico Majolino

2007-01-01

255

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  

Microsoft Academic Search

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

D. R. Leblanc; R. L. Smith; D. B. Kent; L. B. Barber; R. W. Harvey

2008-01-01

256

[Assessment Instruments: Semantic Differential Survey: Science, Form AF; Student Opinion Survey: Science Methods; Elementary Education Field Experience Survey.  

ERIC Educational Resources Information Center

This document comprises the second of two appendices (B) to a final report of a study, completed at Central Michigan University, focusing on the development of a competency-based elementary teacher preparation module in science education. Contained in this appendix are the assessment instruments used in the study--Semantic Differential Survey:…

Oana, Robert G.; Eiszler, Charles F.

257

Evaluation of shallow subsurface models with microtremor survey method for earthquake disaster prevention  

NASA Astrophysics Data System (ADS)

Most of Japanese local governments have been estimating whole picture of quake damage under scenario earthquakes to reduce both casualties and physical damage. Saitama prefectural government, which is adjacent to north of Tokyo, have already made the estimation four times since 1970's. This estimation requires precise mathematical models of subsurface structures for calculating ground surface accelerations during massive quakes. The models have been updated with every new research. In the early models, the shallow layers had been created with applying geological layers of typical 241 types to the whole prefecture. On the other hand, in the current models, the shallow layers are created with the results of drilling surveys under public works. This update on the models allows us to estimate the quake damage more precisely in every 250m square throughout the prefecture. However even the current models are not complete yet. Because the drilling surveys have not been done enough in rural areas compared with urban areas. The models of shallow layers in rural areas have therefore been created by interpolating with considering terrains among the locations of drilling surveys. Thereby accuracy of the models depends on that of the interpolations. Against this background authors have examined the accuracy of the models by making comparisons of phase velocity dispersions between observed velocities through spatial autocorrelation (SPAC) technique and calculated velocities from the models. Two types of SPAC arrays with radii of 3m, 30m are deployed and data acquisition time is 30min for each array. The result shows that the subsurface structures of urban areas are well modeled, because both the dispersion curves are almost agreed, furthermore amplitude responses of the models are in good agreement with the responses determined by the results of microtremor survey method (MSM). In contrast, the subsurface structures of rural areas include cases that have not been modeled with sufficient accuracy, and the dominant frequency in amplitude responses show differences between the models and the MSM results. This suggests that the existing models of rural areas need to be improved further, and it is confirmed that the models, especially in the shallow layers, can be updated efficiently by using the MSM.

Shiraishi, H.; Sasaka, K.; Hamamoto, H.; Hachinohe, S.; Ishiyama, T.

2011-12-01

258

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

259

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

260

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

261

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

262

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...

263

Proposed expansion of the City of Albuquerque/U.S. Geological Survey ground-water-level monitoring network for the middle Rio Grande Basin, New Mexico  

USGS Publications Warehouse

The Middle Rio Grande Basin in central New Mexico, extending from Cochiti Lake on the north to San Acacia on the south, covers an area of about 3,060 square miles. Ground-water withdrawals in the basin are concentrated in and around the city of Albuquerque. Because of rapid increases in population and associated ground-water pumpage, a network of wells was established cooperatively by the City of and the U.S. Geological Survey between April 1982 and September 1983 to monitor changes in ground-water levels throughout the basin. Expansion of this network has been identified as an essential element in plans to study the relation between surface water and ground water in the basin. An inventory of existing wells in the Albuquerque metropolitan area has brought together information on about 400 wells that either are being monitored for water levels or would be good candidates for monitoring. About 115 wells or well sites are proposed as additions to the current 128-well ground-water-level monitoring network for the Middle Rio Grande Basin. Despite the extensive network that would be created by the addition of the proposed existing wells, however, certain parts of the Albuquerque metropolitan area would remain without adequate coverage areally and/or with depth in the Santa Fe Group aquifer until the installation of the proposed new monitoring wells.

Bexfield, L. M.

1998-01-01

264

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

265

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

266

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

267

Relationships between autofocus methods for SAR and self-survey techniques for SONAR.  

National Technical Information Service (NTIS)

Autofocus methods in SAR and self-survey techniques in SONAR have a common mathematical basis in that they both involve estimation and correction of phase errors introduced by sensor position uncertainties. Time delay estimation and correlation methods ha...

D. E. Wahl C. V. Jakowatz D. C. Ghiglia P. H. Eichel

1991-01-01

268

Survey of Numerical Methods for Solution of Large Systems of Linear Equations for Electromagnetic Field Problems.  

National Technical Information Service (NTIS)

The objective of this report is to survey many of the popular methods for the solution of large matrix equations with the hope of finding an efficient method suitable for both electromagnetic scattering and radiation problems and system identification pro...

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

1981-01-01

269

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

270

A survey of surveys  

SciTech Connect

A new era for the field of Galactic structure is about to be opened with the advent of wide-area digital sky surveys. In this article, the author reviews the status and prospects for research for 3 new ground-based surveys: the Sloan Digital Sky Survey (SDSS), the Deep Near-Infrared Survey of the Southern Sky (DENIS) and the Two Micron AU Sky Survey (2MASS). These surveys will permit detailed studies of Galactic structure and stellar populations in the Galaxy with unprecedented detail. Extracting the information, however, will be challenging.

Kent, S.M.

1994-11-01

271

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

272

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

273

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

274

Sensitivity of Spaceborne and Ground Radar Comparison Results to Data Analysis Methods and Constraints  

NASA Technical Reports Server (NTRS)

With the availability of active weather radar observations from space from the Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission (TR.MM) satellite, numerous studies have been performed comparing PR reflectivity and derived rain rates to similar observations from ground-based weather radars (GR). These studies have used a variety of algorithms to compute matching PR and GR volumes for comparison. Most studies have used a fixed 3-dimensional Cartesian grid centered on the ground radar, onto which the PR and GR data are interpolated using a proprietary approach and/or commonly available GR analysis software (e.g., SPRINT, REORDER). Other studies have focused on the intersection of the PR and GR viewing geometries either explicitly or using a hybrid of the fixed grid and PR/GR common fields of view. For the Dual-Frequency Precipitation Radar (DPR) of the upcoming Global Precipitation Measurement (GPM) mission, a prototype DPR/GR comparison algorithm based on similar TRMM PR data has been developed that defines the common volumes in terms of the geometric intersection of PR and GR rays, where smoothing of the PR and GR data are minimized and no interpolation is performed. The PR and GR volume-averaged reflectivity values of each sample volume are accompanied by descriptive metadata, for attributes including the variability and maximum of the reflectivity within the sample volume, and the fraction of range gates in the sample average having reflectivity values above an adjustable detection threshold (typically taken to be 18 dBZ for the PR). Sample volumes are further characterized by rain type (Stratiform or Convective), proximity to the melting layer, underlying surface (land/water/mixed), and the time difference between the PR and GR observations. The mean reflectivity differences between the PR and GR can differ between data sets produced by the different analysis methods; and for the GPM prototype, by the type of constraints and categorization applied to the data. In this paper, we will show results comparing the 3-D gridded analysis "black box" approach to the GPM prototype volume-matching approach, using matching TRMM PR and WSR-88D ground radar data. The affects of applying data constraints and data categorizations on the volume-matched data to the results will be shown, and explanations of the differences in terms of data and analysis algorithm characteristics will be presented. Implications of the differences to the determination of PR/DPR calibration differences and use of ground radar data to evaluate the PR and DPR attenuation correction algorithms will be discussed.

Morris, Kenneth R.; Schwaller, Mathew

2011-01-01

275

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.

Mateo, Jill M.; Cavigelli, Sonia A.

2008-01-01

276

Evaluation of ground motion scaling methods for analysis of structural systems  

USGS Publications Warehouse

Ground motion selection and scaling comprises undoubtedly the most important component of any seismic risk assessment study that involves time-history analysis. Ironically, this is also the single parameter with the least guidance provided in current building codes, resulting in the use of mostly subjective choices in design. The relevant research to date has been primarily on single-degree-of-freedom systems, with only a few studies using multi-degree-of-freedom systems. Furthermore, the previous research is based solely on numerical simulations with no experimental data available for the validation of the results. By contrast, the research effort described in this paper focuses on an experimental evaluation of selected ground motion scaling methods based on small-scale shake-table experiments of re-configurable linearelastic and nonlinear multi-story building frame structure models. Ultimately, the experimental results will lead to the development of guidelines and procedures to achieve reliable demand estimates from nonlinear response history analysis in seismic design. In this paper, an overview of this research effort is discussed and preliminary results based on linear-elastic dynamic response are presented. ?? ASCE 2011.

O'Donnell, A. P.; Beltsar, O. A.; Kurama, Y. C.; Kalkan, E.; Taflanidis, A. A.

2011-01-01

277

Robust methods for differential abundance analysis in marker gene surveys  

PubMed Central

We introduce a novel methodology for differential abundance analysis in sparse high-throughput marker gene survey data. Our approach, implemented in the metagenomeSeq Bioconductor package, relies on a novel normalization technique and a statistical model that accounts for under-sampling: a common feature of large-scale marker gene studies. We show, using simulated data and several published microbiota datasets, that metagenomeSeq outperforms the tools currently used in this field.

Paulson, Joseph N.; Stine, O. Colin; Bravo, Hector Corrada; Pop, Mihai

2013-01-01

278

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.

279

A method to automate the radiological survey process  

SciTech Connect

This document describes the USRAD system, a hardware/software ranging and data transmission system, that provides real-time position data and combines it with other portable instrument measurements. Live display of position data and onsite data reduction, presentation, and formatting for reports and automatic transfer into databases are among the unusual attributes of USRADS. Approximately 25% of any survey-to-survey report process is dedicated to data recording and formatting, which is eliminated by USRADS. Cost savings are realized by the elimination of manual transcription of instrument readout in the field and clerical formatting of data in the office. Increased data reliability is realized by ensuring complete survey coverage of an area in the field, by elimination of mathematical errors in conversion of instrument readout to unit concentration, and by elimination of errors associated with transcribing data from the field into report format. The USRAD system can be adapted to measure other types of pollutants or physical/chemical/geological/biological conditions in which portable instrumentation exists. 2 refs., 2 figs.

Berven, B.A.; Blair, M.S.

1987-01-01

280

First National Survey of Lead and Allergens in Housing: survey design and methods for the allergen and endotoxin components.  

PubMed Central

From July 1998 to August 1999, the U.S. Department of Housing and Urban Development and the National Institute of Environmental Health Sciences conducted the first National Survey of Lead and Allergens in Housing. The purpose of the survey was to assess children's potential household exposure to lead, allergens, and bacterial endotoxins. We surveyed a sample of 831 homes, representing 96 million permanently occupied, noninstitutional housing units that permit resident children. We administered questionnaires to household members, made home observations, and took environmental samples. This article provides general background information on the survey, an overview of the survey design, and a description of the data collection and laboratory methods pertaining to the allergen and endotoxin components. We collected dust samples from a bed, the bedroom floor, a sofa or chair, the living room floor, the kitchen floor, and a basement floor and analyzed them for cockroach allergen Bla g 1, the dust mite allergens Der f 1 and Der p 1, the cat allergen Fel d 1, the dog allergen Can f 1, the rodent allergens Rat n 1 and mouse urinary protein, allergens of the fungus Alternaria alternata, and endotoxin. This article provides the essential context for subsequent reports that will describe the prevalence of allergens and endotoxin in U.S. households, their distribution by various housing characteristics, and their associations with allergic diseases such as asthma and rhinitis.

Vojta, Patrick J; Friedman, Warren; Marker, David A; Clickner, Robert; Rogers, John W; Viet, Susan M; Muilenberg, Michael L; Thorne, Peter S; Arbes, Samuel J; Zeldin, Darryl C

2002-01-01

281

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

282

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

283

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

284

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

285

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

286

Method of moments analysis of an aperture in a thick ground plane  

NASA Astrophysics Data System (ADS)

The problem of electromagnetic scattering from and transmission through an arbitrarily shaped aperture is considered. The aperture is in a thick infinite perfectly conducting ground plane. The conducting walls of the cavity inside the ground plane are of arbitrary shape. The apertures at both ends of the cavity are also of arbitrary shape. The structure is illuminated by an incident plane electromagnetic wave. The Green's function for this complicated problem is almost impossible to determine. Therefore the surface equivalence principle is used to reduce this complex problem into three simpler ones. Each such problem consists of equivalent surface currents radiating in unbounded media. Therefore the free space Green's function is used for each problem. An equivalent surface magnetic current placed on the top aperture produces the scattered field in the region where the impressed sources are. The total field inside the cavity is produced by two surface equivalent magnetic currents on the apertures and an equivalent surface electric current residing on the walls of the cavity as well as on both apertures. The transmitted field on the opposite side of the impressed sources is computed by an equivalent surface magnetic current residing on the bottom aperture. Enforcing the boundary conditions on the tangential components of electric and magnetic fields on both apertures and on the tangential components of electric field on the cavity walls results in a set of three coupled integral equations for the equivalent surface currents. Whenever possible, image theory is used to simplify the equations. These equations are numerically solved using the method of moments. The surfaces are approximated by planar triangular patches. RWG functions are used for expansion functions. An approximate Galerkin method is used for testing. The method is applicable for the general case where all three regions have different material parameters. Results are computed for the case where all these parameters are the same. The method is applicable for arbitrary sized apertures and cavities. However due to limited computing resources, only problems in the resonance region, where dimensions are comparable to wavelength, are considered here. Computed results are given for the case of two square apertures connected by a square prism, two cross apertures connected by a square prism cavity, two circular apertures connected by a cylindrical cavity, and finally two circular apertures connected by a conical cavity. Our computed results are compared with results in the literature obtained by using other methods. Very good agreement is observed.

Olcen, Ahmet Burak

287

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

288

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...

289

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

290

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

291

Survey of Texture Segmentation, Classification, and Synthesis Methods.  

National Technical Information Service (NTIS)

This report reviews the literature in the areas of image texture segmentation, classification, and synthesis methods. The approaches to these areas are grouped into areas of fractal, spline, neural networks, modeling, and stochastic methods. An immense am...

B. S. Bourgeois C. L. Walker

1992-01-01

292

Estimates of Ground-Water Recharge Based on Streamflow-Hydrograph Methods: Pennsylvania.  

National Technical Information Service (NTIS)

This study, completed by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey (T&GS), provides estimates of groundwater recharge for watersheds t...

D. W. Risser R. W. Conger J. E. Ulrich M. P. Asmussen

2005-01-01

293

A survey of motif discovery methods in an integrated framework  

Microsoft Academic Search

BACKGROUND: There has been a growing interest in computational discovery of regulatory elements, and a multitude of motif discovery methods have been proposed. Computational motif discovery has been used with some success in simple organisms like yeast. However, as we move to higher organisms with more complex genomes, more sensitive methods are needed. Several recent methods try to integrate additional

Geir Kjetil Sandve; Finn Drabløs

2006-01-01

294

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

295

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

296

Assessing subsurface strata using geophysical and geotechnical methods for designing structures near ground cracks  

NASA Astrophysics Data System (ADS)

This paper presents a combined approach using both geophysical and geotechnical approaches to study and evaluate the subsurface strata near ground for sites suffering from faults and cracks. It demonstrates how both techniques can be utilized to gather useful information for design geotechnical engineers. The safe distance for construction close to a ground crack is mainly dependant on the subsurface stratification and the engineering properties of underlying soils or rocks. Other factors include the area geology and concepts of safety margins. This study is carried out for a site in Al-Qassim region, Saudi Arabia. This type of faults and cracks can normally occur due to a geological or physical event or due to the nature and properties of the subsurface material. The geotechnical works included advancing rotary boreholes to depths of 25m to 31m with sampling and testing. The geophysical method used included performing 2D electrical resistivity profiles. The results of geophysical and geotechnical works showed good and close agreement. The use of 2D electrical resistivity was found useful to establish the layer thicknesses of shale and highly plastic clay. This cannot be determined without deep and expensive direct boring investigation. The results showed that a thick layer of expansive soil, which is considered a high-risk soil type containing large percentage of highly plastic clay materials, underlies the site. The volume changes due to humidity variations can result in either swelling or shrinking. These changes can have significant impact on engineering structures such as light buildings and roads. The logic of placing structures in close vicinity of the cracks is based on lateral stresses exerted on the crack face. The layer thickness is a detrimental factor to establish a safe design distance. Stress distribution analysis procedure is explained.

AlFouzan, F.; Dafalla, M.; Mutaz, E.

2012-04-01

297

An empirical method of RH correction for satellite estimation of ground-level PM concentrations  

NASA Astrophysics Data System (ADS)

A hygroscopic growth model suitable for local aerosol characteristics and their temporal variations is necessary for accurate satellite retrieval of ground-level particulate matters (PM). This study develops an empirical method to correct the relative humidity (RH) impact on aerosol extinction coefficient and to further derive PM concentrations from satellite observations. Not relying on detailed information of aerosol chemical and microphysical properties, this method simply uses the in-situ observations of visibility (VIS), RH and PM concentrations to characterize aerosol hygroscopicity, and thus makes the RH correction capable of supporting the satellite PM estimations with large spatial and temporal coverage. In this method, the aerosol average mass extinction efficiency (?ext) is used to describe the general hygroscopic growth behaviors of the total aerosol populations. The association between ?ext and RH is obtained through empirical model fitting, and is then applied to carry out RH correction. Nearly one year of in-situ measurements of VIS, RH and PM10 in Beijing urban area are collected for this study and RH correction is made for each of the months with sufficient data samples. The correlations between aerosol extinction coefficients and PM10 concentrations are significantly improved, with the monthly correlation R2 increasing from 0.26-0.63 to 0.49-0.82, as well as the whole dataset's R2 increasing from 0.36 to 0.68. PM10 concentrations are retrieved through RH correction and validated for each season individually. Good agreements between the retrieved and observed PM10 concentrations are found in all seasons, with R2 ranging from 0.54 in spring to 0.73 in fall, and the mean relative errors ranging from -2.5% in winter to -10.8% in spring. Based on the satellite AOD and the model simulated aerosol profiles, surface PM10 over Beijing area is retrieved through the RH correction. The satellite retrieved PM10 and those observed at ground sites agree well with each other, with R2 = 0.46 and a relative error of 19.3%.

Wang, Zifeng; Chen, Liangfu; Tao, Jinhua; Liu, Yang; Hu, Xuefei; Tao, Minghui

2014-10-01

298

State of the ART Survey of Methods of Cost Effectiveness Evaluation.  

National Technical Information Service (NTIS)

An extensive bibliography of industry and government published brochures, pamphlets, studies and reports, gathered in a general state-of-the-art survey as related to Army Aviation, were researched for all references to current and projected methods of cos...

R. F. Meissner M. A. Biagioli

1967-01-01

299

A survey of data mining methods for linkage disequilibrium mapping  

PubMed Central

Data mining methods are gaining more interest as potential tools in mapping and identification of complex disease loci. The methods are well suited to large numbers of genetic marker loci produced by high-throughput laboratory analyses, but also might be useful for clarifying the phenotype definitions prior to more traditional mapping analyses. Here, the current data mining-based methods for linkage disequilibrium mapping and phenotype analyses are reviewed.

2006-01-01

300

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

301

An integrated approach to landslide characterisation and ground model development: geophysical, geotechnical and remote sensing methods  

NASA Astrophysics Data System (ADS)

Landslides are complex, strongly heterogeneous natural phenomena. A considerable number of landslide types exist, exhibiting varying states, distributions and styles of activity. If a better understanding of landslide internal processes is to be achieved, firstly, an understanding of landslide internal structure is required. Here, an example of an integrated approach to landslide characterisation is presented, which makes use of surface and subsurface investigative methods. Surface geomorphology is mapped and interpreted using immersive three-dimensional (3D) visualisation software to interpret airborne LiDAR data and aerial photographs. Subsurface structure is determined by volumetric 3D electrical resistivity tomography (ERT), along with core logging and associated field and laboratory based geotechnical testing. An integrated approach for ground model development, which takes into account both subsurface and surface investigative methods, is shown to improve the conclusions that can be drawn from a given site investigation. This is achieved by calibration of the geophysical results with direct physical property measurements of materials taken from the landslide and its environs. In particular, the use of 3D ERT at different spatial resolutions provides a means of volumetrically characterising the subsurface expression of both site scale (tens of metres) geological structure, and finer (metre to sub-metre) scale earth-flow related structures, which were not effectively revealed by either the 1D information derived from discrete intrusive sampling, or the 2D surface data provided by remote sensing.

Merritt, Andrew; Chambers, Jonathan; Murphy, William; West, Jared; Gunn, David; Wilkinson, Paul; Dixon, Neil; Meldrum, Phil

2013-04-01

302

Ground-based airglow imaging interferometer. Part 2: forward model and inverse method.  

PubMed

The ground-based airglow imaging interferometer (GBAII) observes the nighttime airglow of the O2(0-1) 867.7 nm line, peaked at 94 km altitude, to measure the upper atmospheric wind and temperature field. Its forward model, a code package in interactive data language (IDL), is developed to simulate the expected imaging interference fringes. It includes eight modules to simulate the light source, the atmospheric radiation transmission, the wide-angle Michelson interferometer, the interference filter, the optical system decay function, the responsivity, the imaging CCD, and the noises. The inverse method is also developed for obtaining the rest phase calibration, temperature, and wind. By means of both theoretical tools, we carry out a comparison of theoretical results with a field observation case. The apparent quantities J1-p from the forward model has the deviation of 1.5%-2.5% compared with that from the observation image. The temperature falls mainly in the range of 167-196 K with the precision of 2 K. The zonal and meridional winds are mainly in the region of 5.1 to 46.5??m/s and 12.5 to 48.3??m/s respectively, with errors of 13.2 to 21.5??m/s. The consistent trends between the observation results and standard models (MSISE90 and HWM93) suggest that the forward model and inverse method are suitable for GBAII. PMID:24787394

Tang, Yuanhe; Duan, Xiaodong; Gao, Haiyang; Qu, Ouyang; Jia, Qijie; Cao, Xiangang; Wei, Shenni; Yang, Rui

2014-04-10

303

Perspective ground-based method for diagnostics of the lower ionosphere and the neutral atmosphere  

NASA Astrophysics Data System (ADS)

We present a new perspective ground-based method for diagnostics of the ionosphere and atmosphere parameters. The method uses one of the numerous physical phenomena observed in the ionosphere illuminated by high-power radio waves. It is a generation of the artificial periodic irregularities (APIs) in the ionospheric plasma. The APIs were found while studying the effects of ionospheric high-power HF modification. It was established that the APIs are formed by a standing wave that occurs due to interference between the upwardly radiated radio wave and its reflection off the ionosphere. The API studies are based upon observation of the Bragg backscatter of the pulsed probe radio wave from the artificial periodic structure. Bragg backscatter occurs if the spatial period of the irregularities is equal to half a wavelength of the probe signal. The API techniques makes it possible to obtain the following information: the profiles of electron density from the lower D-region up to the maximum of the F-layer; the irregular structure of the ionosphere including split of the regular E-layer, the sporadic layers; the vertical velocities in the D- and E-regions of the ionosphere; the turbulent velocities, turbulent diffusion coefficients and the turbopause altitude; the neutral temperatures and densities at the E-region altitudes; the parameters of the internal gravity waves and their spectral characteristics; the relative concentration of negative oxygen ions in the D-region. Some new results obtained by the API technique are discussed .

Bakhmetieva, N. V.; Grigoriev, G. I.; Tolmacheva, A. V.

304

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

305

A multireference perturbation method using non-orthogonal Hartree-Fock determinants for ground and excited states  

NASA Astrophysics Data System (ADS)

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_{occ}^2N_{virt}^3. Unlike most active space methods, ?SCF(2) treats the ground and excited state determinants even-handedly. We apply ?SCF(2) to the H2, hydrogen fluoride, and H4 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

2013-11-01

306

Comparison of two methods for delineating land use near monitoring wells used for assessing quality of shallow ground water  

USGS Publications Warehouse

Two methods were compared for delineating land use near shallow monitoring wells. These wells were used to assess the effects of agricultural cropland on the quality of recently recharged ground water in two sand and gravel aquifers located near land surface. The two methods for delineating land use near wells were (1) the sector method, which used potentiometric-surface maps to estimate average flow direction and a ground-water-flow model to estimate maximum length of contributing area to the monitoring well within an upgradient sector; and (2) the circle method, which used a 500- meter radius circle around the well based on a national empirical analysis. Land uses were compiled for 29 wells in each of two surficial aquifers in the Red River of the North Basin within the area defined by each method. Land use near each well was interpreted from orthorectified photographs and site inspection for both delineation methods. Land use near individual wells characterized by each method varied greatly, which can affect the results of statistical correlations between land use and water quality. Land use determined by the circle method related more closely to the land use for each entire study area. Land use determined by the sector method (within 200 meters from the wells) compared more favorably to ground-water quality based on nitrate concentrations. The maximum length of contributing areas to wells estimated in this study may be of value for other studies of unconsolidated sand and gravel aquifers with similar hydrogeological characteristics of permeability, water-table slopes, recharge, and depth to water. The additional effort required for estimating the model delineation of land use and land cover for the sector method must be weighed against the improved confidence in statistical correlation between land use and the quality of shallow ground water. Improved scientific confidence and understanding of relations between land use and quality of ground water may encourage more effective implementation of land and water management for protecting water quality

Lorenz, D. L.; Goldstein, R. M.; Cowdery, T. K.; Stoner, J. D.

2003-01-01

307

Clutter reduction and detection of landmine objects in ground penetrating radar data using likelihood method  

Microsoft Academic Search

In this paper, an algorithm is proposed to reduce clutter signal due to the reflection from the ground surface in ground penetrating radar (GPR) measurements. The proposed technique has been applied to a GPR, which has been used to detect subsurface anti-personnel (AP) landmines. A very simple model is used to model the GPR clutter and the target signal. This

Galal Nadim

2008-01-01

308

Parallel octree-based multiresolution mesh method for large-scale earthquake ground motion simulation  

NASA Astrophysics Data System (ADS)

Large scale ground motion simulation requires supercomputing systems in order to obtain reliable and useful results within reasonable elapsed time. In this study, we develop a framework for terascale ground motion simulations in highly heterogeneous basins. As part of the development, we present a parallel octree-based multiresolution finite element methodology for the elastodynamic wave propagation problem. The octree-based multiresolution finite element method reduces memory use significantly and improves overall computational performance. The framework is comprised of three parts; (1) an octree-based mesh generator, Euclid developed by TV and O'Hallaron, (2) a parallel mesh partitioner, ParMETIS developed by Karypis et al.[2], and (3) a parallel octree-based multiresolution finite element solver, QUAKE developed in this study. Realistic earthquakes parameters, soil material properties, and sedimentary basins dimensions will produce extremely large meshes. The out-of-core versional octree-based mesh generator, Euclid overcomes the resulting severe memory limitations. By using a parallel, distributed-memory graph partitioning algorithm, ParMETIS partitions large meshes, overcoming the memory and cost problem. Despite capability of the Octree-Based Multiresolution Mesh Method ( OBM3), large problem sizes necessitate parallelism to handle large memory and work requirements. The parallel OBM 3 elastic wave propagation code, QUAKE has been developed to address these issues. The numerical methodology and the framework have been used to simulate the seismic response of both idealized systems and of the Greater Los Angeles basin to simple pulses and to a mainshock of the 1994 Northridge Earthquake, for frequencies of up to 1 Hz and domain size of 80 km x 80 km x 30 km. In the idealized models, QUAKE shows good agreement with the analytical Green's function solutions. In the realistic models for the Northridge earthquake mainshock, QUAKE qualitatively agrees, with at most a factor of 2.5, with the observational data. Through simulations for several models, ranging in size from 400,000 to 300 million degrees of freedom on the 512-processors Cray T3E and the 3000-processors HP-Compaq AlphaServer Cluster at the Pittsburgh Supercomputing Center, we achieve excellent performance and scalability.

Kim, Eui Joong

309

Survey of methods for secure connection to the internet  

NASA Astrophysics Data System (ADS)

This paper describes a study of a security method of protecting inside network computers against outside miscreants and unwelcome visitors and a control method when these computers are connected with the Internet. In the present Internet, a method to encipher all data cannot be used, so that it is necessary to utilize PEM (Privacy Enhanced Mail) capable of the encipherment and conversion of secret information. For preventing miscreant access by eavesdropping password, one-time password is effective. The most cost-effective method is a firewall system. This system lies between the outside and inside network. By limiting computers that directly communicate with the Internet, control is centralized and inside network security is protected. If the security of firewall systems is strictly controlled under correct setting, security within the network can be secured even in open networks such as the Internet.

Matsui, Shouichi

1994-04-01

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

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

312

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

313

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

314

Method of Sieves. A Survey of Recent Applications.  

National Technical Information Service (NTIS)

The method of sieves is a technique of nonparametric estimation in which estimators are restricted by an increasing sequence of subsets of the parameter space with the subsets indexed by the sample size. The need for this technique arises in situations wh...

I. W. McKeague

1985-01-01

315

A Survey of Methods in the Human Potential Movement  

ERIC Educational Resources Information Center

Training methods which affect the mind, body consciousness, values, and purpose of life, according to this article, include biofeedback, extrasensory perception, Yoga, transcendental meditation, and Zen. The article describes some elements common to these systems, lists a number of the systems with their costs, and gives some considerations in…

Margolis, Fredric

1977-01-01

316

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

317

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

318

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

319

Ground-based methods reproduce space-flight experiments and show that weak vibrations trigger microtubule self-organisation.  

PubMed

The effect of weightlessness on physical and biological systems is frequently studied by experiments in space. However, on the ground, gravity effects may also be strongly attenuated using methods such as magnetic levitation and clinorotation. Under suitable conditions, in vitro preparations of microtubules, a major element of the cytoskeleton, self-organise by a process of reaction-diffusion: self-organisation is triggered by gravity and samples prepared in space do not self-organise. Here, we report experiments carried out with ground-based methods of clinorotation and magnetic levitation. The behaviour observed closely resembles that of the space-flight experiment and suggests that many space experiments could be carried out equally well on the ground. Using clinorotation, we find that weak vibrations also trigger microtubule self-organisation and have an effect similar to gravity. Thus, in some in vitro biological systems, vibrations are a countermeasure to weightlessness. PMID:16380203

Glade, Nicolas; Beaugnon, Eric; Tabony, James

2006-04-20

320

Ground water contamination  

SciTech Connect

This book covers: Ground water contamination and basic concepts of water law; Federal law governing water contamination and remediation; Ground water flow and contaminant migration; Ground water cleanup under CERCLA; Technical methods of remediation and prevention of contamination; Liability for ground water contamination; State constraints on contamination of ground water; Water quantity versus water quality; Prevention of use of contaminated ground water as an alternative to remediation; Economic considerations in liability for ground water contamination; and Contamination, extraction, and injection issues.

Not Available

1991-01-01

321

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

322

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.

Royce, Christine A.; Wiley, David A.

2005-02-01

323

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

324

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

325

Thermal Profile Method to Identify Potential Ground-Water Discharge Areas and Preferred Salmonid Habitats for Long River Reaches.  

National Technical Information Service (NTIS)

The purposes of this report are to document a method to thermally profile long (5-25 km), river reaches and to describe the importance of streamflow temperature and ground-water discharge, both of which are functionally related to a thermal profile in con...

J. J. Vaccaro K. J. Maloy

2006-01-01

326

EFFECTS OF GROUND ULV (ULTRA-LOW VOLUME) APPLICATIONS OF FENTHION ON ESTUARINE BIOTA. 2. ANALYTICAL METHODS AND RESULTS  

EPA Science Inventory

Methods of analyses were validated for quantitating fenthion residues in samples from two salt marsh sites subjected to ground ultra-low volume sprays. Concentrations of these residues were followed from the water's surface, through the water column and onto the sediment. For all...

327

Method for Assessing the Quality of Model-Based Estimates of Ground Temperature and Atmospheric Moisture Using Satellite Data.  

National Technical Information Service (NTIS)

A method is developed for validating model-based estimates of atmospheric moisture and ground temperature using satellite data. The approach relates errors in estimates of clear-sky longwave fluxes at the top of the Earth-atmosphere system to errors in ge...

M. L. C. Wu S. Schubert C. I. Lin I. Stajner

2000-01-01

328

Comparison of Two Methods for Delineating Land Use Near Monitoring Wells Used for Assessing Quality of Shallow Ground Water.  

National Technical Information Service (NTIS)

Two methods were compared for delineating land use near shallow monitoring wells. These wells were used to assess the effects of agricultural cropland on the quality of recently recharged ground water in two sand and gravel aquifers located near land surf...

D. L. Lorenz R. M. Goldstein T. K. Cowdery J. D. Stoner

2003-01-01

329

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

330

Deep ground-water investigation by combined VES\\/MTS methods near Ho Chi Minh City, Viet Nam  

Microsoft Academic Search

In the agglomeration of Ho Chi Minh City (HCMC), South Viet Nam, located near the eastern edge of the Mekong Delta, both superficial Quaternary and deep Tertiary Alluvium may contain brackish or saline water from ground surface to great depths. The combination of two complementary geophysical methods, the Vertical Electrical Sounding (VES) for shallow investigation, and the Magnetotelluric Sounding (MTS)

V. N. Pham; D. Boyer; T. K. T. Nguyen; V. G. Nguyen

2009-01-01

331

Multiresolution Structured and Unstructured Finite Element Method for Three-Dimensional Attenuated Earthquake Ground Motion Modeling in Basins including Topography  

Microsoft Academic Search

We present an efficient finite element method (FEM) for large-scale attenuated earthquake ground motion simulation, which reduces modeling and computational costs by using a hybrid structured\\/unstructured mesh capable of treating underground and above surface topography. The meshing process starts with a uniform high- resolution background cell discretization, after which, using an octree structure, the grid is thinned to tailor the

T. Ichimura; M. Hori; J. Bielak; E. Shinotake

2007-01-01

332

Method and basis set dependence of anharmonic ground state nuclear wave functions and zero-point energies: Application to SSSH  

Microsoft Academic Search

One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which

Stephen J. Kolmann; Meredith J. T. Jordan

2010-01-01

333

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

334

Use of Accelerated Testing Methods with Survey Data: How Water Quality Affects Appliance Life  

Microsoft Academic Search

Salinity (mineral content), which is present naturally in residential water, affects the service lives of water-using appliances. We surveyed, by mail, 681 households in the Arkansas River basin in southeastern Colorado, where tap water salinity varies from 100 to 3,500 mg\\/L. The survey collected information on ages of appliances in service and on ages atfailure. We developed a generalized method

Guy E. Ragan; Carole J. Makela; Robert A. Young

1996-01-01

335

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

336

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

337

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.

2014-01-01

338

A Systematic Method for Improving Indoor Environment Quality through Occupant Satisfaction Surveys  

Microsoft Academic Search

SUMMARY A systematic method for assessing and improving indoor environment quality (IEQ) is developed for existing and occupied office buildings. The method begins with an occupant satisfaction survey that is directed to everyone working in a building. The structure of the questions follows a pattern that offers valuable information of the technical reasons leading to dissatisfaction. The questions assess satisfaction

Tarja Takki; Maija Virta

339

A survey of variable selection methods in two Chinese epidemiology journals  

Microsoft Academic Search

BACKGROUND: Although much has been written on developing better procedures for variable selection, there is little research on how it is practiced in actual studies. This review surveys the variable selection methods reported in two high-ranking Chinese epidemiology journals. METHODS: Articles published in 2004, 2006, and 2008 in the Chinese Journal of Epidemiology and the Chinese Journal of Preventive Medicine

Huimin Liao; Henry S Lynn

2010-01-01

340

A Survey of Instructors of Art Methods Classes for Preservice Elementary Teachers.  

ERIC Educational Resources Information Center

Reports on a survey of 122 elementary art education methods instructors in the United States and Canada. Finds that methods courses focus on one of three general areas: (1) those that focus on art itself; (2) those that focus on pedagogical issues; or (3) those that focus on the non-art major preservice teacher. (CFR)

Jeffers, Carol S.

1993-01-01

341

A survey of methods that transform data models into Ontology models  

Microsoft Academic Search

In this paper, we provide a comprehensive survey of the methods available to (semi-)automatically generate an Ontology model from a data model. Although there are several different instantiations of database management systems in use today, the transformation methods to date have generally focused on relational data models as the prime source of the information; we therefore concentrated on this when

Khalid M. Albarrak; Edgar H. Sibley

2011-01-01

342

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

343

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

344

[Application of a segmentation method to an intraoral epidemiologic survey].  

PubMed

The segmentation method has been applied to the results of an epidemiological study on the oral conditions of 2000 children of Strasbourg, 6 to 15 years old. The classification in decreasing order of the factors influencing the DMF/T index was the following: the age, the socio-professional group of the father, the sex, the calculus index, the gingival index, the df/t, the morphological index and the plaque index. The df/t index was bound in decreasing order of importance to the DMF/T index, the age, the socio-professional group of the father, the sex, the calculus index, the gingival index, the plaque index and the morphological index. For the gingival index, the segmentation analysis indicated in decreasing order the importance of the plaque index, the socio-professional group of the father, the age, the DMF/T index, the calculus index, the df/t index, the morphological index and the sex. PMID:1060619

Cahen, P M; Nanopoulos, F; Frank, R M

1975-09-01

345

The Jamaica asthma and allergies national prevalence survey: rationale and methods  

PubMed Central

Background Asthma is a significant public health problem in the Caribbean. Prevalence surveys using standardized measures of asthma provide valid prevalence estimates to facilitate regional and international comparisons and monitoring of trends. This paper describes methods used in the Jamaica Asthma and Allergies National Prevalence Survey, challenges associated with this survey and strategies used to overcome these challenges. Methods/Design An island wide, cross-sectional, community-based survey of asthma, asthma symptoms and allergies was done among adults and children using the European Community Respiratory Health Survey Questionnaire for adults and the International Study of Asthma and Allergies in Children. Stratified multi-stage cluster sampling was used to select 2, 163 adults aged 18 years and older and 2, 017 children aged 2-17 years for the survey. The Kish selection table was used to select one adult and one child per household. Data analysis accounted for sampling design and prevalence estimates were weighted to produce national estimates. Discussion The Jamaica Asthma and Allergies National Prevalence Survey is the first population- based survey in the Caribbean to determine the prevalence of asthma and allergies both in adults and children using standardized methods. With response rates exceeding 80% in both groups, this approach facilitated cost-effective gathering of high quality asthma prevalence data that will facilitate international and regional comparison and monitoring of asthma prevalence trends. Another unique feature of this study was the partnership with the Ministry of Health in Jamaica, which ensured the collection of data relevant for decision-making to facilitate the uptake of research evidence. The findings of this study will provide important data on the burden of asthma and allergies in Jamaica and contribute to evidence-informed planning of comprehensive asthma management and education programs.

2010-01-01

346

Ground deformation associated with post-mining activity at the French-German border revealed by novel InSAR time series method  

NASA Astrophysics Data System (ADS)

We present a novel methodology for integration of multiple InSAR data sets for computation of two dimensional time series of ground deformation. The proposed approach allows combination of SAR data acquired with different acquisition parameters, temporal and spatial sampling and resolution, wavelength and polarization. Produced time series have combined coverage, improved temporal resolution and lower noise level. We apply this methodology for mapping coal mining related ground subsidence and uplift in the Greater Region of Luxembourg along the French-German border. For this we processed 167 Synthetic Aperture Radar ERS-1/2 and ENVISAT images acquired between 1995 and 2009 from one ascending (track 29) and one descending (track 337) tracks and created over five hundred interferograms that were used for time series analysis. Derived vertical and east-west linear deformation rates show with remarkable precision a region of localized ground deformation located above and caused by mining and post-mining activities. Time series of ground deformation display temporal variability: reversal from subsidence to uplift and acceleration of subsidence in the vertical component, and horizontal motion toward the center of the subsidence on the east-west component. InSAR results are validated by leveling measurements collected by the French Geological Survey (BRGM) during 2006-2008. We determined that deformation rate changes are mainly caused by water level variations in the mines. Due to higher temporal and spatial resolution the proposed space-borne method detected a larger number of subsidence and uplift areas in comparison to leveling measurements restricted to annual monitoring of benchmark points along roads. We also identified one deformation region that is not precisely located above the mining sites. Comparison of InSAR measurements with the water levels measured in the mining pits suggest that part of the water that filled the galleries after termination of the dewatering systems may come from this region. Providing that enough SAR data is available, this method opens new opportunities for detecting and locating man-made and natural ground deformation signals with high temporal resolution and precision.

Samsonov, Sergey; d'Oreye, Nicolas; Smets, Benoît

2013-08-01

347

Celestial Exoplanet Survey Occulter: A Concept for Direct Imaging of Extrasolar Earth-like Planets from the Ground  

NASA Astrophysics Data System (ADS)

We present a new concept for detecting and characterizing extrasolar planets down to Earth size or smaller through direct imaging. The New Worlds Observer (NWO) occulter developed by Cash and coworkers is placed in a particular geometrical setup in which fuel requirements are small and the occulter is used in combination with ground-based telescopes, presumably leading to an extreme cost efficiency compared to other concepts with similar science goals. We investigate the various aspects of the given geometry, such as the dynamics and radiation environment of the occulter, and construct a detailed example target list to ensure that an excellent science case can be maintained despite the limited sky coverage. It is found that more than 200 systems can be observed with two to three visits per system, using only a few tons of fuel. For each system, an Earth-sized planet with an Earth-like albedo can be found in the habitable zone in less than 2 hr.

Janson, M.

2007-02-01

348

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

349

Detection of contaminant plumes in ground water of Long Island, New York, by electromagnetic terrain-conductivity surveys  

USGS Publications Warehouse

Electromagnetic terrain conductivity surveys were conducted at four landfills in Suffolk county and at an artificial recharge site in Nassau County to assess the feasibility of this technique for detecting contaminant plumes. The technique was successful at three of the landfills; results compared closely with those indicated by specific conductance of water from observation wells on the sites. Data from the three sites for which the technique was successful--the Horseblock Road landfill , the Manorville scavenger waste disposal facility, and the Riverhead landfill--revealed pronounced terrain conductivity anomalies that reflect known contaminant plumes. Plumes at the other two sites--Blydenburgh landfill and the East Meadow artificial recharge site--could not be detected because cultural interferences were too great and, at the Blydenburgh site, depth to water was too great. The interferences included pipelines, utility cables, and traffic. Given favorable conditions, such as high plume conductivity, lack of cultural interferences, and a depth of less than 100 ft to the plume, electromagnetic surveying can provide a rapid means of locating contaminant plumes. (Author 's abstract)

Mack, T. J.; Maus, P. E.

1986-01-01

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

3D temporal evolution and modeling of ground deformation recorded on Mt. Etna from the 2007 to 2008 through the SISTEM method  

NASA Astrophysics Data System (ADS)

A study of the ground deformation pattern of Mount Etna volcano, based on the results of the SISTEM (Simultaneous and Integrated Strain Tensor Estimation from geodetic and satellite deformation Measurements) integration method is reported. The SISTEM enables integrating geodetic in situ ground deformation measurements (GPS) with satellite interferometric measurements (ENVISAT), in order to obtain high resolution 3D displacement maps, allowing to overcome the limitations of each technique and take advantage of the particular features of each of them. In this work ground motion data provided by GPS surveys are integrated with the interferometric synthetic aperture radar (InSAR) Envisat data, collected from 2007 to 2008, to provide 3D displacements maps. We imaged the time evolution of ground displacement measured along the Line Of Sight (LOS) of the Envisat satellite for both ascending and descending Envisat geometries. The main deformation episode occurred on Mt. Etna during the 2007-2008 time period was the May 2008 dike intrusion and the following 2008-2009 eruption. It started on May 13th, 2008, with the opening of an eruptive fissure propagating inside the topographical depression of the Valle del Bove, where the lava flows expanded. The eruption produced a lava flow of about 6 Km length, and it was preceded and accompanied by strong seismic release, and lava fountaining activity. The 3D temporal evolution of ground deformation was analyzed in order to define the dynamics preceding and accompanying the onset of the 2008-2009 Mt. Etna eruption. In particular, this analysis reveals a slight inflation visible on the upper western side of the volcano in the pre-eruptive period (form June 2007 to May 2008) characterized by a small amplitude of the ground deformation, except on the eastern flank. Data inversions detected a pressurizing source located beneath the western flank of the volcano at a depth of about 3Km bsl. In the period encompassing the eruption onset, the main ground deformation occurred around the summit craters, in the nearby of the eruptive fissures. The displacement pattern reveals also a rapid decay of the deformation gradient with the altitude confirming the shallow depth of the intrusion. The northward dyke propagation, occurred after the beginning of the eruption, was well detected by the SISTEM integrated displacement maps; it was confirmed by on field structural surveys that revealed a dry fracture field, propagating from the summit area towards the NNW direction for about 2.5 km. The inversion results confirm a dike located under the vents of the eruption and extending towards NNW, westward dipping. In the post-intrusion period (from May to July 2008), a deflation of the volcano was detected, according to a depressurizing source, localized by data inversion, beneath the summit craters.

Bonforte, A.; Guglielmino, F.; Puglisi, G.

2012-04-01

352

Application of nonlinear-regression methods to a ground-water flow model of the Albuquerque Basin, New Mexico  

USGS Publications Warehouse

This report documents the application of nonlinear-regression methods to a numerical model of ground-water flow in the Albuquerque Basin, New Mexico. In the Albuquerque Basin, ground water is the primary source for most water uses. Ground-water withdrawal has steadily increased since the 1940's, resulting in large declines in water levels in the Albuquerque area. A ground-water flow model was developed in 1994 and revised and updated in 1995 for the purpose of managing basin ground- water resources. In the work presented here, nonlinear-regression methods were applied to a modified version of the previous flow model. Goals of this work were to use regression methods to calibrate the model with each of six different configurations of the basin subsurface and to assess and compare optimal parameter estimates, model fit, and model error among the resulting calibrations. The Albuquerque Basin is one in a series of north trending structural basins within the Rio Grande Rift, a region of Cenozoic crustal extension. Mountains, uplifts, and fault zones bound the basin, and rock units within the basin include pre-Santa Fe Group deposits, Tertiary Santa Fe Group basin fill, and post-Santa Fe Group volcanics and sediments. The Santa Fe Group is greater than 14,000 feet (ft) thick in the central part of the basin. During deposition of the Santa Fe Group, crustal extension resulted in development of north trending normal faults with vertical displacements of as much as 30,000 ft. Ground-water flow in the Albuquerque Basin occurs primarily in the Santa Fe Group and post-Santa Fe Group deposits. Water flows between the ground-water system and surface-water bodies in the inner valley of the basin, where the Rio Grande, a network of interconnected canals and drains, and Cochiti Reservoir are located. Recharge to the ground-water flow system occurs as infiltration of precipitation along mountain fronts and infiltration of stream water along tributaries to the Rio Grande; subsurface flow from adjacent regions; irrigation and septic field seepage; and leakage through the Rio Grande, canal, and Cochiti Reservoir beds. Ground water is discharged from the basin by withdrawal; evapotranspiration; subsurface flow; and flow to the Rio Grande, canals, and drains. The transient, three-dimensional numerical model of ground-water flow to which nonlinear-regression methods were applied simulates flow in the Albuquerque Basin from 1900 to March 1995. Six different basin subsurface configurations are considered in the model. These configurations are designed to test the effects of (1) varying the simulated basin thickness, (2) including a hypothesized hydrogeologic unit with large hydraulic conductivity in the western part of the basin (the west basin high-K zone), and (3) substantially lowering the simulated hydraulic conductivity of a fault in the western part of the basin (the low-K fault zone). The model with each of the subsurface configurations was calibrated using a nonlinear least- squares regression technique. The calibration data set includes 802 hydraulic-head measurements that provide broad spatial and temporal coverage of basin conditions, and one measurement of net flow from the Rio Grande and drains to the ground-water system in the Albuquerque area. Data are weighted on the basis of estimates of the standard deviations of measurement errors. The 10 to 12 parameters to which the calibration data as a whole are generally most sensitive were estimated by nonlinear regression, whereas the remaining model parameter values were specified. Results of model calibration indicate that the optimal parameter estimates as a whole are most reasonable in calibrations of the model with with configurations 3 (which contains 1,600-ft-thick basin deposits and the west basin high-K zone), 4 (which contains 5,000-ft-thick basin de

Tiedeman, C. R.; Kernodle, J. M.; McAda, D. P.

1998-01-01

353

A comparison of web-based and paper-based survey methods: testing assumptions of survey mode and response cost.  

PubMed

Web-based surveys have become more prevalent in areas such as evaluation, research, and marketing research to name a few. The proliferation of these online surveys raises the question, how do response rates compare with traditional surveys and at what cost? This research explored response rates and costs for Web-based surveys, paper surveys, and mixed-mode surveys. The participants included evaluators from the American Evaluation Association (AEA). Results included that mixed-mode, while more expensive, had higher response rates. PMID:19605623

Greenlaw, Corey; Brown-Welty, Sharon

2009-10-01

354

Different Views on Inquiry: A Survey of Science and Mathematics Methods Instructors  

NASA Astrophysics Data System (ADS)

The national science standards encourage the use of inquiry-based instruction to teach difficult scientific concepts. As part of a larger study to investigate teachers' views on the nature of inquiry-based instruction, a survey was administered to Science and Mathematics methods course instructors to determine their views on inquiry, as well as to explore the success and difficulties associated with teaching this difficult concept. In addition, we wished to obtain their views on the ``5 E's'' method, an inquiry method specifically designed to promote conceptual change that is often taught as ``the'' method to utilize. Initial survey data suggests there are many different views among Science and Mathematics methods course instructors about the nature of inquiry. This paper discusses the difficulties encountered with the ``5 E's'' and teaching inquiry-based methods to teachers.

Withee, Thomas; Lindell, Rebecca

2006-02-01

355

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

356

Lightning arc damage to optical fiber ground wires (OPGW): parameters and test methods  

Microsoft Academic Search

The present version of IEEE Standard 1138 gives no guidance regarding the possible damage to OPGW from exposure to lightning. Industry experience with conventional overhead ground wires has settled on an overall diameter in excess of 12 mm for good long-term mechanical performance. This may not be enough to protect optical fibers from long-term damage. Test specifications, using the existing

William A. Chisholm; Jody P. Levine; Pritindra Chowdhuri

2001-01-01

357

New method for the realistic estimation of seismic ground motion in megacities: The case of Rome.  

National Technical Information Service (NTIS)

A hybrid technique, based on mode summation and finite differences, is used to simulate the ground motion induced in the city of Rome by the January 13, 1915, Fucino (Italy) earthquake (M=6.9). The technique allows us to take into consideration source, pa...

D. Faeh C. Iodice P. Suhadole G. F. Panza

1994-01-01

358

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

359

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

360

GBFEL-TIE (Ground-Based Free Electron Laser Technology Experiment) sample survey on White Sands Missile Range, New Mexico: The NASA, Stallion, and Orogrande Alternatives. Final report  

SciTech Connect

Three locations on White Sands Missile Range, New Mexico, are under consideration as alternatives for the proposed Ground-Based Free-Electron Laser Technology Integration Experiment (GBFEL-TIE). The study conducted jointly by Prewitt and Associates, Inc., and the Office of Contract Archeology, was designed to provide input into the GBFEL-TIE Draft Environmental Impact Statement concerning the potential impact of the proposed project on cultural resources in each of the alternatives. The input consists of a series of predictions based on data gathered from two sources: (1) a cultural resource sample survey (15%) of two alternatives conducted as part of this study, and (2) from a previous survey of the third alternative. A predictive model was devleoped and applied using these data that estimated the potential impact of the GBFEL-TIE facility on the cultural resources within each alternative. The predictions indicate that the NASA alternatives, by far, the least favorable location for the facility followed by the Orogrande and Stallion Alternatives.

Seaman, T.J.; Doleman, W.H.

1988-09-30

361

Warm and cold gas in low-mass protostars : Herschel Space Observatory and ground-based surveys  

NASA Astrophysics Data System (ADS)

The primary focus of this thesis is the formation of low-mass protostars, specifically the earliest deeply embedded phase, when material from the collapsing envelope is still accreted onto the growing young star. Rotational transitions of CO and O2 data are obtained by the Herschel Space Observatory key projects, WISH and HOP, together with ground-based observations from APEX and the JCMT. We have found that CO and its isotopologs have different line profiles tracing different materials in the protostellar regions. Our new high-J rotational transitons of CO is key to characterize the warmer parts of the protostellar envelope and quantify feedback of the protostars on their surroundings in terms of shocks, ultraviolet (UV) heating, photodissociation, and outflow dispersal. Radiative transfer modeling was performed to determine the CO abundance structure in the envelope, showing evidence for significant freeze-out in the coldest regions in the parts of the envelope where the temperature exceeds 25 K. A tentative detection of O2 is reported toward the source position of a protostar, which originates from the surrounding cloud. These kind of detailed studies of the physical and chemical structure of low-mass protostars are important for a complete understanding of the evolution of young stellar objects (YSOs).

Yildiz, Umut

2013-05-01

362

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

363

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

PubMed

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. PMID:24952517

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

2014-06-21

364

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

365

Evaluation of consumer-style cooking methods for reduction of Escherichia coli O157:H7 in ground beef.  

PubMed

The objective of this study was to evaluate the thermal inactivation of Escherichia coli O157:H7 in ground beef cooked to an internal temperature of 71.1 degrees C (160 degrees F) under conditions simulating consumer-style cooking methods. To compare a double-sided grill (DSG) with a single-sided grill (SSG), two different cooking methods were used for the SSG: for the one-turnover (OT-SSG) method, a patty was turned once when the internal temperature reached 40 degrees C, and for the multiturnover (MT-SSG) method, a patty was turned every 30 s. Patties (100 g, n = 9) inoculated with a five-strain mixture of E. coli O157: H7 at a concentration of 10(7) CFU/g were cooked until all three temperature readings (for two sides and the center) for a patty were 71.1 degrees C. The surviving E. coli O157:H7 cells were enumerated on sorbitol MacConkey (SMAC) agar and on phenol red agar base with 1% sorbitol (SPRAB). The order of the cooking methods with regard to the cooking time required for the patty to reach 71.1 degrees C was as follows: DSG (2.7 min) < MT-SSG (6.6 min) < OT-SSG (10.9 min). The more rapid, higher-temperature cooking method was more effective (P < 0.01) in destroying E. coli O157:H7 in ground beef. E. coli O157:H7 reduction levels were clearly differentiated among treatments as follows: OT-SSG (4.7 log10 CFU/g) < MT-SSG (5.6 log10 CFU/g) < DSG (6.9 log10 CFU/g). Significantly larger numbers of E. coil O157:H7 were observed on SPRAB than on SMAC agar. To confirm the safety of ground beef cooked to 71.1 degrees C, additional patties (100 g, n = 9) inoculated with lower concentrations of E. coli O157:H7 (10(3) to 10(4) CFU/g) were tested. The ground beef cooked by the OT-SSG method resulted in two (22%) of nine samples testing positive after enrichment, whereas no E. coli O157:H7 was found for samples cooked by the MT-SSG and DSG methods. Our findings suggest that consumers should be advised to either cook ground beef patties in a grill that cooks the top and the bottom of the patty at the same time or turn patties frequently (every 30 s) when cooking on a grill that cooks on only one side. PMID:12801005

Rhee, Min-Suk; Lee, Sun-Young; Hillers, Virginia N; McCurdy, Sandra M; Kang, Dong-Hyun

2003-06-01

366

Microgravimetric and ground penetrating radar geophysical methods to map the shallow karstic cavities network in a coastal area (Marina Di Capilungo, Lecce, Italy)  

NASA Astrophysics Data System (ADS)

The coastal area Marina di Capilungo located ~50km south-west of Lecce (Italy) is one of the sites at greatest geological risk in the Salento peninsula. In the past few decades, Marina di Capilungo has been affected by a series of subsidence events, which have led in some cases to the partial collapse of buildings and road surfaces. These events had both social repercussions, causing alarm and emergency situations, and economic ones in terms of the funds for restoration. With the aim of mapping the subsurface karstic features, and so to assess the dimensions of the phenomena in order to prevent and/or limit the ground subsidence events, integrated geophysical surveys were undertaken in an area of ~70000m2 at Marina di Capilungo. Large volume voids such as karstic cavities are excellent targets for microgravity surveys. The absent mass of the void creates a quantifiable disturbance in the earth's gravitational field, with the magnitude of the disturbance directly proportional to the volume of the void. Smaller shallow voids can be detected using ground-penetrating radar (GPR). Microgravimetric and GPR geophysical methods were therefore used. An accurate interpretation was obtained using small station spacing and accurate geophysical data processing. The interpretation was facilitated by combining the modelling of the data with the geological and topographic information for explored caves. The GPR method can complement the microgravimetric technique in determining cavity depths and in verifying the presence of off-line features and numerous areas of small cavities, which may be difficult to be resolved with only microgravimetric data. However, the microgravimetric can complement GPR in delineating with accuracy the shallow cavities in a wide area where GPR measurements are difficult. Furthermore, microgravity surveys in an urban environment require effective and accurate consideration of the effects given by infrastructures, such as buildings, as well as those given by topography, near a gravity station. The acquired negative anomaly in the residual Bouguer anomalies field suggested the presence of possible void features. GPR and modelling data were used to estimate the depth and shape of the anomalous source.

Leucci, Giovanni; De Giorgi, Lara

2010-06-01

367

Exact ground state Monte Carlo method for Bosons without importance sampling.  

PubMed

Generally "exact" quantum Monte Carlo computations for the ground state of many bosons make use of importance sampling. The importance sampling is based either on a guiding function or on an initial variational wave function. Here we investigate the need of importance sampling in the case of path integral ground state (PIGS) Monte Carlo. PIGS is based on a discrete imaginary time evolution of an initial wave function with a nonzero overlap with the ground state, which gives rise to a discrete path which is sampled via a Metropolis-like algorithm. In principle the exact ground state is reached in the limit of an infinite imaginary time evolution, but actual computations are based on finite time evolutions and the question is whether such computations give unbiased exact results. We have studied bulk liquid and solid (4)He with PIGS by considering as initial wave function a constant, i.e., the ground state of an ideal Bose gas. This implies that the evolution toward the ground state is driven only by the imaginary time propagator, i.e., there is no importance sampling. For both phases we obtain results converging to those obtained by considering the best available variational wave function (the shadow wave function) as initial wave function. Moreover we obtain the same results even by considering wave functions with the wrong correlations, for instance, a wave function of a strongly localized Einstein crystal for the liquid phase. This convergence is true not only for diagonal properties such as the energy, the radial distribution function, and the static structure factor, but also for off-diagonal ones, such as the one-body density matrix. This robustness of PIGS can be traced back to the fact that the chosen initial wave function acts only at the beginning of the path without affecting the imaginary time propagator. From this analysis we conclude that zero temperature PIGS calculations can be as unbiased as those of finite temperature path integral Monte Carlo. On the other hand, a judicious choice of the initial wave function greatly improves the rate of convergence to the exact results. PMID:20568848

Rossi, M; Nava, M; Reatto, L; Galli, D E

2009-10-21

368

Ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan mountains, central Asia, by ground penetrating radar survey  

NASA Astrophysics Data System (ADS)

The results of radar survey for three times are presented, aiming to determine ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan Mountains, central Asia. Results show that the distribution of ice is more in the center and lesser at both ends of the glacier. The bedrock is quite regular with altitudes decreasing towards the ice front, showing the U-shaped subglacial valley. By comparison, typical ice thinning along the centerline of the East Branch of the glacier was 10-18 m for the period 1981-2006, reaching a maximum of ˜30 m at the terminus. The corresponding ice volume was 10296.2 × 10 4 m 3, 8797.9 × 10 4 m 3 and 8115.0 × 10 4 m 3 in 1981, 2001 and 2006, respectively. It has decreased by 21.2% during the past 25 years, which is the direct result of glacier thinning. In the same period, the ice thickness, area and terminus decreased by 12.2%, 10.3%, and 3.6%, respectively. These changes are responses to the regional climatic warming, which show a dramatic increase of 0.6°C (10 a) -1 during the period 1981-2006.

Wang, Puyu; Li, Zhongqin; Jin, Shuang; Zhou, Ping; Yao, Hongbing; Wang, Wenbin

2014-05-01

369

Detection of Planets in Extremely Weak Central Perturbation Microlensing Events via Next-generation Ground-based Surveys  

NASA Astrophysics Data System (ADS)

Even though the recently discovered high-magnification event MOA-2010-BLG-311 had complete coverage over its peak, confident planet detection did not happen due to extremely weak central perturbations (EWCPs, fractional deviations of <~ 2%). For confident detection of planets in EWCP events, it is necessary to have both high cadence monitoring and high photometric accuracy better than those of current follow-up observation systems. The next-generation ground-based observation project, Korea Microlensing Telescope Network (KMTNet), satisfies these conditions. We estimate the probability of occurrence of EWCP events with fractional deviations of <=2% in high-magnification events and the efficiency of detecting planets in the EWCP events using the KMTNet. From this study, we find that the EWCP events occur with a frequency of >50% in the case of <~ 100 M E planets with separations of 0.2 AU <~ d <~ 20 AU. We find that for main-sequence and sub-giant source stars, >~ 1 M E planets in EWCP events with deviations <=2% can be detected with frequency >50% in a certain range that changes with the planet mass. However, it is difficult to detect planets in EWCP events of bright stars like giant stars because it is easy for KMTNet to be saturated around the peak of the events because of its constant exposure time. EWCP events are caused by close, intermediate, and wide planetary systems with low-mass planets and close and wide planetary systems with massive planets. Therefore, we expect that a much greater variety of planetary systems than those already detected, which are mostly intermediate planetary systems, regardless of the planet mass, will be significantly detected in the near future.

Chung, Sun-Ju; Lee, Chung-Uk; Koo, Jae-Rim

2014-04-01

370

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

371

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

372

Simulation of an ultra-wideband antenna for step-frequency ground penetrating radar using method of moments  

Microsoft Academic Search

Presented in this paper are the results of simulation of ultra-wideband antennas for step-frequency ground penetrating radar (GPR) using IE3D software realizing method of moments. Features of planar antenna currents distribution, influencing on radiations parameters are discussed. Ways of improvement of antenna characteristics accounting for the features of the antenna utilization are proposed. The simulation data for planar tapered slot

Ye. Maksimovitch; V. Mikhnev; P. Vainikainen

2005-01-01

373

Two-dimensional and three-dimensional NUFFT migration method for landmine detection using ground-penetrating Radar  

Microsoft Academic Search

Ground-penetrating radar (GPR) has been widely used for landmine detection due to its high signal-to-noise ratio (SNR) and superior ability to image nonmetallic landmines. Processing GPR data to obtain better target images and to assist further object detection has been an active research area. Phase-shift migration is a widely used method; however, its wavenumber space is nonuniformly sampled because of

Jiayu Song; Qing Huo Liu; Pete Torrione; Leslie Collins

2006-01-01

374

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

375

Mycologg: a new accelerated test method for wood durability above ground  

Microsoft Academic Search

If not properly handled, selected and protected, wood will be degraded by bacteria, fungi and also insects. In order to ensure\\u000a service life, durability tests are needed. Most accelerated laboratory tests on wood durability are focused either on fungi\\u000a attacks or the uptake of moisture. Accelerated field tests in ground contact are of limited use since they could be difficult

Å. Blom; M. Bergström

2005-01-01

376

Methods of estimating or accounting for neighborhood associations with health using complex survey data.  

PubMed

Reasons for health disparities may include neighborhood-level factors, such as availability of health services, social norms, and environmental determinants, as well as individual-level factors. Investigating health inequalities using nationally or locally representative data often requires an approach that can accommodate a complex sampling design, in which individuals have unequal probabilities of selection into the study. The goal of the present article is to review and compare methods of estimating or accounting for neighborhood influences with complex survey data. We considered 3 types of methods, each generalized for use with complex survey data: ordinary regression, conditional likelihood regression, and generalized linear mixed-model regression. The relative strengths and weaknesses of each method differ from one study to another; we provide an overview of the advantages and disadvantages of each method theoretically, in terms of the nature of the estimable associations and the plausibility of the assumptions required for validity, and also practically, via a simulation study and 2 epidemiologic data analyses. The first analysis addresses determinants of repeat mammography screening use using data from the 2005 National Health Interview Survey. The second analysis addresses disparities in preventive oral health care using data from the 2008 Florida Behavioral Risk Factor Surveillance System Survey. PMID:24723000

Brumback, Babette A; Cai, Zhuangyu; Dailey, Amy B

2014-05-15

377

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

378

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

379

Assessing the practising physician using patient surveys: a systematic review of instruments and feedback methods  

Microsoft Academic Search

Evans RG, Edwards A, Evans S, Elwyn B and Elwyn G. Assessing the practising physician using patient surveys: a systematic review of instruments and feedback methods. Family Practice 2007; 24: 117-127. Background. Individual physician performance assessment is a vital part of the medical regu- lation debate. In this context, the patient perspective is seen as a potentially valid component. Yet,

Richard G Evans; Adrian Edwards; Sean Evans; Benjamin Elwyn; Glyn Elwyn

380

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

381

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

382

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

383

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

384

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

385

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

386

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

387

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

388

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

389

A multireference perturbation method using non-orthogonal Hartree-Fock determinants for ground and excited states.  

PubMed

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 Mo?ller-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(occ)(2)N(virt)(3). Unlike most active space methods, ?SCF(2) treats the ground and excited state determinants even-handedly. We apply ?SCF(2) to the H2, hydrogen fluoride, and H4 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. PMID:24206284

Yost, Shane R; Kowalczyk, Tim; Van Voorhis, Troy

2013-11-01

390

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

391

[Methods for endotracheal tube fixation. Results of a survey of intensive care nurses].  

PubMed

There are a wide variety of strategies and methods used in securing and managing the oral endotracheal tube and mouth and oral care in German clinical intensive care nursing for mechanically ventilated patients. There are no nationally recognized guidelines or recommendations on this topic. A survey among intensive care nurses identified the most widely used nursing strategies and methods. Regarding the results of the survey and international literature findings, the commonly used strategies and methods are discussed. Following these discussions, there are recommendations for improving nursing care of orally intubated patients in intensive care, including the aspects of evidence identified, currently used methods and patient needs. Also included are aspects of patient safety, potential complications and quality-orientated nursing care within a system having limited overall nursing care resources. PMID:23868519

Rothaug, O; Müller-Wolff, A; Kaltwasser, R; Dubb, R; Hermes, C

2013-09-01

392

Survey of systems safety analysis methods and their application to nuclear waste management systems  

NASA Astrophysics Data System (ADS)

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, GO 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

393

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

394

The U.S. Geological Survey Modular Ground-Water Model - PCGN: A Preconditioned Conjugate Gradient Solver with Improved Nonlinear Control  

USGS Publications Warehouse

The preconditioned conjugate gradient with improved nonlinear control (PCGN) package provides addi-tional means by which the solution of nonlinear ground-water flow problems can be controlled as compared to existing solver packages for MODFLOW. Picard iteration is used to solve nonlinear ground-water flow equations by iteratively solving a linear approximation of the nonlinear equations. The linear solution is provided by means of the preconditioned conjugate gradient algorithm where preconditioning is provided by the modi-fied incomplete Cholesky algorithm. The incomplete Cholesky scheme incorporates two levels of fill, 0 and 1, in which the pivots can be modified so that the row sums of the preconditioning matrix and the original matrix are approximately equal. A relaxation factor is used to implement the modified pivots, which determines the degree of modification allowed. The effects of fill level and degree of pivot modification are briefly explored by means of a synthetic, heterogeneous finite-difference matrix; results are reported in the final section of this report. The preconditioned conjugate gradient method is coupled with Picard iteration so as to efficiently solve the nonlinear equations associated with many ground-water flow problems. The description of this coupling of the linear solver with Picard iteration is a primary concern of this document.

Naff, Richard L.; Banta, Edward R.

2008-01-01

395

The survey activities in whole Japan done by Tadataka Inou using the methods of Yoshitoki  

NASA Astrophysics Data System (ADS)

In 2001, 207 sheets of copies of Japanese map were discovered in the Library of Congress of USA in Washington D.C. Those maps called "Daizu" were surveyed by Tadataka Inou who was a surveyor in Edo era. Last year, home coming exhibitions for those maps were held in all over Japan during one year. These highly accurate maps were surveyed by Tadataka Inou who entered into a private school of Yoshitoki Takahashi who was a governmental official regarding astronomy of the Edo shogunate using theory of astronomy and methods of surveying learned from Yoshitoki Inou completed these maps spending 3,727 days and traveling 39,000 km distance on foot.

Hakoiwa, Eiichi

2005-06-01

396

Judging Judicial Education: A Survey Grounded in a Qualitative Study Provides Useful Information for Educational Planners. Proceedings of a Symposium Presented at the Annual Meeting of the Mid-South Educational Research Association (Mobile, AL, November 10-13, 1987).  

ERIC Educational Resources Information Center

The focus of the symposium was on an evaluation of judicial education in Alabama conducted by the University of Alabama Evaluation and Assessment Laboratory (EAL). The papers include: (1) "Design: From Qualitative Study to Grounded Questionnaire" (J. S. Rogers); (2) "Implementation: Conducting the Qualitative Study and the Survey" (G. A. Turner,…

Bolland, Kathleen A.; And Others

397

Graphical-User Interface for the U.S. Geological Survey's SUTRA Code using Argus ONE (for Simulation of Variable-Density Saturated-Unsaturated Ground-Water Flow with Solute or Energy Transport).  

National Technical Information Service (NTIS)

This report describes a Graphical-User Interface (GUI) for SUTRA, the U.S. Geological Survey (USGS) model for saturated-unsaturated variable-fluid-density ground-water flow with solute or energy transport, which combines a USGS-developed code that interfa...

A. M. Shapiro C. I. Voss D. Boldt

1997-01-01

398

Twist Method for Quantum Ground-State Problems and its Application to Antiferromagnetic Heisenberg Chains with Competing Interactions  

NASA Astrophysics Data System (ADS)

We present a quantum version of the twist method which has been developed for classical systems. A finite size scaling form for the excess ground state energy is derived and tested for an S=1/2 antiferromagnetic Heisenberg chain with next nearest neighbor interactions: H= J ?( Sj · Sj+1 +? Sj · Sj+2 )with J>0 and ?>0. Using an exact diagonalization method, we obtain the critical value ?c \\cong 0.246 of the fluid-dimer transition, which is very close to the reliable value recently obtained by Okamoto and Nomura (Phys. Lett. A 169 (1992) 433).

Okamoto, Kiyomi; Ueno, Yohtaro

1995-01-01

399

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

400

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

401

Efficient and spectrally accurate numerical methods for computing ground and first excited states in Bose Einstein condensates  

NASA Astrophysics Data System (ADS)

In this paper, we present two efficient and spectrally accurate numerical methods for computing the ground and first excited states in Bose-Einstein condensates (BECs). We begin with a review on the gradient flow with discrete normalization (GFDN) for computing stationary states of a nonconvex minimization problem and show how to choose initial data effectively for the GFDN. For discretizing the gradient flow, we use sine-pseudospectral method for spatial derivatives and either backward Euler scheme (BESP) or backward/forward Euler schemes for linear/nonlinear terms (BFSP) for temporal derivatives. Both BESP and BFSP are spectral order accurate for computing the ground and first excited states in BEC. Of course, they have their own advantages: (i) for linear case, BESP is energy diminishing for any time step size where BFSP is energy diminishing under a constraint on the time step size; (ii) at every time step, the linear system in BFSP can be solved directly via fast sine transform (FST) and thus it is extremely efficient, and in BESP it needs to be solved iteratively via FST by introducing a stabilization term and thus it could be efficient too. Comparisons between BESP and BFSP as well as other existing numerical methods are reported in terms of accuracy and total computational time. Our numerical results show that both BESP and BFSP are much more accurate and efficient than those existing numerical methods in the literature. Finally our new numerical methods are applied to compute the ground and first excited states in BEC in one dimension (1D), 2D and 3D with a combined harmonic and optical lattice potential for demonstrating their efficiency and high resolution.

Bao, Weizhu; Chern, I.-Liang; Lim, Fong Yin

2006-12-01

402

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

403

Methods for evaluating ground dislocations in mining areas / Metoda oceny przemieszcze? budowli na terenie górniczym  

NASA Astrophysics Data System (ADS)

Underground exploitation of natural resources results in disturbance of the original equilibrium in the strata and leads to the emergence of the so-called subsidence troughs on the ground surface (Florkowska, 2010). Due to ground distortion, buildings located in these areas suffer damages and deformations, including angular tilts. An instrument for measuring constructions' angles of slope is known as an inclinometer. The prototypical vibrating wire inclinometer discussed in the present paper has three wires (each of them cooperating with one electromagnet) on which a weight - attached to an arm - is suspended. Thanks to this, it comes of use in a range of procedures, such as measuring object inclines, or determining the angle between the plane of the incline and the assumed reference direction. As any other vibrating wire transducer, an inclinometer cooperates with a proper electronic device which makes it possible to measure the vibration period for each wire separately. The device is also used for the inclinometer's calibration. Additionally, the paper provides an example of an inclinometer's use in measuring the angular tilt of a historical church tower located in the area affected by underground mining operations connected with exploitation of hard coal.

Kanciruk, Adam

2012-12-01

404

GEOPHYSICAL TECHNIQUES FOR MARITIME ARCHAEOLOGICAL SURVEYS  

Microsoft Academic Search

Over the last ten years, the high-resolution marine geophysical survey field has witnessed significant advances in survey investigation equipment. New equipment is based on acoustic, optical, electrical, and magnetic sensors. This paper will focus on the use of quantitat ive acoustic methods for the high-resolution mapping of the seafloor for archaeological heritage management. In particular multibeam sonar and acoustic ground

Mark Lawrence; Ian Oxley; C. Richard Bates

405

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

406

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

407

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

408

Comparison of survey and photogrammetry methods to position gravity data, Yucca Mountain, Nevada  

SciTech Connect

Locations of gravity stations at Yucca Mountain, Nevada, were determined by a survey using an electronic distance-measuring device and by a photogram-metric method. The data from both methods were compared to determine if horizontal and vertical coordinates developed from photogrammetry are sufficently accurate to position gravity data at the site. The results show that elevations from the photogrammetric data have a mean difference of 0.57 +- 0.70 m when compared with those of the surveyed data. Comparison of the horizontal control shows that the two methods agreed to within 0.01 minute. At a latitude of 45{sup 0}, an error of 0.01 minute (18 m) corresponds to a gravity anomaly error of 0.015 mGal. Bouguer gravity anomalies are most sensitive to errors in elevation, thus elevation is the determining factor for use of photogrammetric or survey methods to position gravity data. Because gravity station positions are difficult to locate on aerial photographs, photogrammetric positions are not always exactly at the gravity station; therefore, large disagreements may appear when comparing electronic and photogrammetric measurements. A mean photogrammetric elevation error of 0.57 m corresponds to a gravity anomaly error of 0.11 mGal. Errors of 0.11 mGal are too large for high-precision or detailed gravity measurements but acceptable for regional work. 1 ref. 2 figs., 4 tabs.

Ponce, D.A.; Wu, S.S.C.; Spielman, J.B.

1985-12-31

409

Your School Grounds Handbook.  

ERIC Educational Resources Information Center

This handbook discusses the process of planning school grounds. It presents ideas for creating good educational landscapes and provides step-by-step procedures to achieve this goal. The steps include ground surveying and analysis, establishing community and school needs and wants, planning changes and preparing the design process, publicizing and…

1997

410

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

411

A simple method to assess unsaturated zone time lag in the travel time from ground surface to receptor  

NASA Astrophysics Data System (ADS)

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.

Sousa, Marcelo R.; Jones, Jon P.; Frind, Emil O.; Rudolph, David L.

2013-01-01

412

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

413

Polynomial combinatorial optimization methods for analysing the ground states of disordered systems  

NASA Astrophysics Data System (ADS)

We discuss the application of polynomial combinatorial optimization algorithms to extract the universal zero-temperature properties of various disordered systems. Dijkstras algorithm is used for models of non-directed elastic lines on general regular graphs with isotropically correlated random potentials. The successive shortest path algorithm for minimum-cost-flow problems is applied for the study of ground state properties and the entanglement of many elastic lines in a disordered environment and the disorder-induced loop percolation transition in a vortex glass model. The pre-flow-push algorithm for minimum-cut-maximum-flow problems is used for the investigation of a roughening transition occurring in a model for elastic manifolds in a periodic potential in the presence of point disorder.

Rieger, Heiko

2003-10-01

414

[Electromagnetic fields emitted in radio- and microwave- frequency range: equipment and methods for the environment protection and survey measurements].  

PubMed

In the paper a review of electromagnetic field sources in radio- and microwave- frequency range is presented. The aim of the study was to analyze possibilities and methods used to survey electromagnetic field (EMF) measurements. Selective and broadband methods with examples of apparatus are described. The accuracy of typical EMF survey measurements was estimated. PMID:19388464

Bie?kowski, Pawe?

2008-01-01

415

New methods for engineering site characterization using reflection and surface wave seismic survey  

NASA Astrophysics Data System (ADS)

This study presents two new seismic testing methods for engineering application, a new shallow seismic reflection method and Time Filtered Analysis of Surface Waves (TFASW). Both methods are described in this dissertation. The new shallow seismic reflection was developed to measure reflection at a single point using two to four receivers, assuming homogeneous, horizontal layering. It uses one or more shakers driven by a swept sine function as a source, and the cross-correlation technique to identify wave arrivals. The phase difference between the source forcing function and the ground motion due to the dynamic response of the shaker-ground interface was corrected by using a reference geophone. Attenuated high frequency energy was also recovered using the whitening in frequency domain. The new shallow seismic reflection testing was performed at the crest of Porcupine Dam in Paradise, Utah. The testing used two horizontal Vibroseis sources and four receivers for spacings between 6 and 300 ft. Unfortunately, the results showed no clear evidence of the reflectors despite correction of the magnitude and phase of the signals. However, an improvement in the shape of the cross-correlations was noticed after the corrections. The results showed distinct primary lobes in the corrected cross-correlated signals up to 150 ft offset. More consistent maximum peaks were observed in the corrected waveforms. TFASW is a new surface (Rayleigh) wave method to determine the shear wave velocity profile at a site. It is a time domain method as opposed to the Spectral Analysis of Surface Waves (SASW) method, which is a frequency domain method. This method uses digital filtering to optimize bandwidth used to determine the dispersion curve. Results from testings at three different sites in Utah indicated good agreement with the dispersion curves measured using both TFASW and SASW methods. The advantage of TFASW method is that the dispersion curves had less scatter at long wavelengths as a result from wider bandwidth used in those tests.

Chaiprakaikeow, Susit

416

Ground-followup studies of the 1977 airborne electromagnetic survey in the Assifar and Mulhal areas, Wadi Bidah district, Kingdom of Saudi Arabia  

USGS Publications Warehouse

Parts of four airborne electromagnetic (AEM) anomalies were selected for study in order to determine the cause of high conductivity of Precambrian rocks underlying extensive areas in the southern Wadi Bidah district, Kingdom of Saudi Arabia. In the Assifar area, which contains an ancient mine or prospect having the same name, geophysical data suggest that a mineralized body may lie beneath and immediately south of the ancient workings. Many other conductive zones detected during the course of the geophysical survey are thought to be related to metavolcanic rocks containing carbonaceous materials. Detailed geologic mapping, and possibly diamond core drilling, will be necessary to fully evaluate the area. In the Mulhal No. 2 area, located about 2 km south of the Mulhal ancient mine, geophysical studies suggest that mineralized rocks extend about 500 m along strike beneath outcrops of gossanous material. A brief review of the AEM ground-followup studies in the Wadi Bidah district suggests that most, if not all, of the AEM conductors are carbonaceous rocks. Secondary causes of conductivity are intense faulting and shearing.

Flanigan, Vincent J.; Sadek, Hamdy

1983-01-01

417

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

418

Study on the Technology and Method of Land Cover Classification for Geographic National Conditions Surveying  

NASA Astrophysics Data System (ADS)

Land Cover is the basis of geographic national conditions monitoring, extracting land cover information timely and accurately has become one of important tasks in the geographic national conditions surveying project. For the current situation of complex land cover type and large amount of data, there has emerged various new classification techniques and methods. However, the big difficult of classification?the large amount of data, the heavy workload of post-editing and other factors have seriously hampered the progress of the project. In this paper, it chooses high-resolution remote sensing image as original data, comprehensivly elaborates present research situation of oriented land cover classification. By the systematical analysis and summary of the basic and key problems of the land cover classification technology, relying on the geographic national information classification and standard system, discusses the available methods preliminarily to improve the accuracy of land cover classification which based on geographic national conditions surveying.

Jia, Y.; Li, H. T.; Gu, H. Y.; Han, Y. S.

2013-07-01

419

A Survey of Attack Techniques on Privacy-Preserving Data Perturbation Methods  

Microsoft Academic Search

We focus primarily on the use of additive and matrix multiplicative data perturbation techniques in privacy preserving data\\u000a mining (PPDM). We survey a recent body of research aimed at better understanding the vulnerabilities of these techniques.\\u000a These researchers assumed the role of an attacker and developed methods for estimating the original data from the perturbed\\u000a data and any available prior

Kun Liu; Chris Giannella; Hillol Kargupta

420

A survey of static analysis methods for identifying security vulnerabilities in software systems  

Microsoft Academic Search

In this paper we survey static analysis methods for identifying security vulnerabilities in software systems. We cover three areas that have been associated with sources of security vulnerabilities: access-control, information-flow, and application-program- ming-interface conformance. Because access control mechanisms fall into two major categories, stack-based access control and role-based access control, we discuss static analysis techniques for these two areas of

Marco Pistoia; Satish Chandra; Stephen J. Fink; Eran Yahav

2007-01-01

421

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

422

Novel survey method finds dramatic decline of wild cotton-top tamarin population  

PubMed Central

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 km2 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.

Savage, Anne; Thomas, Len; Leighty, Katherine A.; Soto, Luis H.; Medina, Felix S.

2010-01-01

423

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

424

Chloride mass-balance method for estimating ground water recharge in arid areas: examples from western Saudi Arabia  

NASA Astrophysics Data System (ADS)

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 and and semi-arid areas of the earth.

Bazuhair, Abdulghaffar S.; Wood, Warren W.

1996-11-01

425

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

426

Detection and analysis of subsurface cracks in ground ceramics using thermal wave method  

NASA Astrophysics Data System (ADS)

During a grinding of ceramics, its superficial layer undergoes structural changes. It results in significant decrease of thermal conductivity of surface. In this paper, a method of quality assessment of ceramics grinding based on analysis of depth profile of thermal properties using thermal wave methods is presented. The method proposed permits to determine a thickness as well as thermal conductivity of damaged layer. It enables indirect optimisation of machining of ceramics' surface.

Suszy?ski, Z.; Majchrzak, P.; Musia?, W.

2005-10-01

427

Methods of practice and guidelines for using survey-grade global navigation satellite systems (GNSS) to establish vertical datum in the United States Geological Survey  

USGS Publications Warehouse

Geodetic surveys have evolved through the years to the use of survey-grade (centimeter level) global positioning to perpetuate and post-process vertical datum. The U.S. Geological Survey (USGS) uses Global Navigation Satellite Systems (GNSS) technology to monitor natural hazards, ensure geospatial control for climate and land use change, and gather data necessary for investigative studies related to water, the environment, energy, and ecosystems. Vertical datum is fundamental to a variety of these integrated earth sciences. Essentially GNSS surveys provide a three-dimensional position x, y, and z as a function of the North American Datum of 1983 ellipsoid and the most current hybrid geoid model. A GNSS survey may be approached with post-processed positioning for static observations related to a single point or network, or involve real-time corrections to provide positioning "on-the-fly." Field equipment required to facilitate GNSS surveys range from a single receiver, with a power source for static positioning, to an additional receiver or network communicated by radio or cellular for real-time positioning. A real-time approach in its most common form may be described as a roving receiver augmented by a single-base station receiver, known as a single-base real-time (RT) survey. More efficient real-time methods involving a Real-Time Network (RTN) permit the use of only one roving receiver that is augmented to a network of fixed receivers commonly known as Continually Operating Reference Stations (CORS). A post-processed approach in its most common form involves static data collection at a single point. Data are most commonly post-processed through a universally accepted utility maintained by the National Geodetic Survey (NGS), known as the Online Position User Service (OPUS). More complex post-processed me