WorldWideScience
1

Reverse time migration for ground penetrating radar using finite difference time domain method; Jikan ryoiki yugenn sabunho ni yoru chichu reda no ribasu taimu maigureshon  

Energy Technology Data Exchange (ETDEWEB)

The reversion time migration, as one of reflection seismic prospecting migration, reverse propagates a wave equation by reverse promoting the differential time, and conducts the migration. The method has such merits as no limit to the inclined angle of a reflection, correspondence to a complex topography etc. And, there is a finite difference time domain (FDTD) that uses the Maxwell equation as it is and makes a difference approximation in the methods differentiating and resolving electro-magnetic fields. It is also possible to apply the reverse time migration onto it. In this speech, using an explosive reflection face, a slope 2 layer structure and models of its reflection points are synthesized by a ground penetrating radar using the FDTD, and reverse time migration is conducted. As a result, it is clarified that the reverse time migration is valid for the ground penetrating radar recording. And, the cases including a ...

1999-02-01

2

Proceedings of the twelfth international conference, applied geologic remote sensing. Practical solutions for real-world problems  

Energy Technology Data Exchange (ETDEWEB)

The topics covered at the conference include: mineral exploration; geological mapping/stratigraphy; environmental monitoring and hydrology; petroleum exploration; radar digital elevation mapping; new commercial remote sensing initiatives; geological hazards and engineering; processing and integration techniques; and hyperspectral geology.

1997-12-31

3

Digital Libraries  

CERN Document Server

Digital Libraries

2008-01-01

5

Application of remote sensing and geophysics to the detection and monitoring of acid mine drainage  

Energy Technology Data Exchange (ETDEWEB)

The results of a study on the application of remote sensing and geophysical methods for the detection and monitoring of acid mine drainage (AMD) are summarized, with emphasis on those that appear most suitable. The study consisted of a literature review, an information survey of users and suppliers, and discussions with various experts. Space-borne sensors, airborne sensors, airborne videography and digital frame cameras, spectroradiometers, radar, and photographic data are considered. Geophysical methods are effective for measurement of sulphides, areas of active chemical oxidation, acid mine drainage, and contaminated ground water movement. The popularity and effectiveness of various geophysical methods are rated for AMD applications. 25 refs., 1 fig., 3 tabs.

1995-06-01

6

The digital library toolkit  

CERN Document Server

The digital library toolkit

2000-01-01

9

A submillimeter wavelength space-based imaging radar  

Science.gov (United States)

This report considers the use of a submillimeter wavelength space-based imaging radar. The main application envisioned is midcourse decoy discrimination for strategic defense, for which it would have the capability of producing a series of images, in real time, at strategic ranges, with less than meter scale resolution and with modest power requirements. Undoubtedly, there are other applications. The requirements for a SAR and ISAR imaging radar at submillimeter wavelength are determined, and the prospect for the development of RF sources to power the radar is examined.

1988-05-01

10

How to build a digital library  

CERN Document Server

How to build a digital library

2010-01-01

12

Digital Library Technology Trends  

CERN Document Server

Digital Library Technology Trends

2002-01-01

14

ACM Digital Library [Online database  

CERN Document Server

ACM Digital Library [Online database

15

FAQs for IIS Solicitation NSF-05551  

Science.gov (United States)

... Science, Computer Vision, Digital Government, Digital Libraries, Digital Society and Technologies ... for Robust Intelligence, Digital Government, and Digital Libraries and Archives. In subsequent years ...

16

Contact Line Pinning by Microfabricated Patterns: Effects of Microscale Topography  

UK PubMed Central (United Kingdom)

We study how the microscale topography of a solid surface affects the apparent advancing and receding angles at the contact line of a liquid drop pinned to this surface. Photolithographic methods...Full Text Available

2009-05-05

17

NRL Fact Book 2010  

Science.gov (United States)

... Tactical Electronic Warfare Division (Code 5700) Visualization Laboratory Transportable step frequency radar Vehicle development laboratory ...

2011-05-15

18

NRL Fact Book  

Science.gov (United States)

... Tactical Electronic Warfare Division (Code 5700) Visualization Laboratory Transportable step frequency radar Vehicle development laboratory ...

2011-05-15

19

Foundation Investigation for Ground Based Radar Project ...  

Science.gov (United States)

... For the P-wave test, the seismic source was an exploding bridgewire (EBW) detonator which was sufficiently strong in energy ...

1990-04-01

20

Modeling Radar Scattering from the Lunar Surface and Analysis of the Effect of Roughness and Ice Inclusions on CPR Values  

Science.gov (United States)

We developed a model for radar scattering from the lunar reoglith layer using vector radiative transfer theory. From this model, both the radar backscattering coefficient and the circular polarization ratio can be predicted analytically as a function of regolith parameters.

2010-03-01

21

DIGITAL LIBRARIES: IMPACT ON SCIENCE ... - MUSPIN - NASA  

Science.gov (United States)

digital libraries, which was identified as a national challenge in the Information ... The linkages between the many digital libraries and information services are ...

22

ALOS satellite imagery utilizations for safeguards  

International Nuclear Information System (INIS)

This paper introduces examples of satellite imageries analysis and utilizations for safeguards activities. Recently, many kinds of satellite imageries are available in the world i.e., high-spatial resolution, multi- and hyper-spectral, multi-function, and multi-polarization radars. The problem is that how to obtain the required information from these digital images. The Japan Aerospace Exploration Agency (JAXA) has successfully launched the Advanced Land Observing Satellite (ALOS, the nickname is 'Daichi') on 24th January, 2006. The mission objectives are cartography, regional observation, disaster monitoring etc. ALOS has three instruments, PRISM, AVNIR-2, and PALSAR, to achieve these objectives. An overview of ALOS is provided. ALOS follows the Japanese Earth Resources Satellite- 1 (JERS-1) and the Advanced Earth Observing Satellite (ADEOS) and utilizes advanced land-observing technology. ALOS is fling in a Sun-synchronous orbit with an ...

2006-10-16

24

The Design of an Interactive Online Help Desk in the Alexandria Digital Library  

CERN Document Server

The Design of an Interactive Online Help Desk in the Alexandria Digital Library

1999-01-01

25

Networked Digital Library of Theses and Dissertations Federated Search  

CERN Document Server

Networked Digital Library of Theses and Dissertations

1995-01-01

26

Emerging technologies for academic libraries in the digital age  

CERN Document Server

Emerging technologies for academic libraries in the digital age

2009-01-01

29

The Anniversary History of Weather Radar Research (40th) in ...  

Science.gov (United States)

... water content according to the hydrometeor type. ... the documentation and the movement personnel and ... Dyer, RM, 1970: Particle fall speeds within ...

1989-01-30

30

SEEK IGLOO Radar Clutter Study  

Science.gov (United States)

... 17 IV. Spatial Amplitude Distributions of Terrain and Sea.....23 Clutter V, Spectral Density Measurements ..... 53 A. Terrain Clutter ..... ...

1977-10-01

31

Radar Analysis of a Tamex Frontal System  

Science.gov (United States)

... 24 1.6. Storm Movement .. .. . ... W hydrometeor fall speed containing the vertical velocity and the particle terminal fall speed (= w + V) ...

1989-08-01

32

Osseointegration of zirconia implants compared with titanium: an in vivo study  

UK PubMed Central (United Kingdom)

BackgroundTitanium and titanium alloys are widely used for fabrication of dental implants. Since the material composition and the surface topography of a biomaterial play a fundamental...Full Text Available

33

Modeling and Control of Airport Queueing Dynamics under Severe ...  

Science.gov (United States)

air traffic controllers at BOS tower and Terminal Radar Ap- .... Runway ) @ Runway. Buffer. Queue. Runway. Stochastic Delay. (M/1 server). (Runway to Fix). ,I, ...

34

INTERPRETATION OF RADAR DATA FROM THE ICY GALILEAN SATELLITES AND ...  

Science.gov (United States)

(1989], however, we modeled the phase using a sum of simple power law terms. We. chose to do our work on Triton's atmosphere using the exponential functions ...

35

April 15 02 - NASA  

Science.gov (United States)

Nov 13, 2006 ... Indicator Experiment (TIE) consists of a wideband sensor to gather radar, ... November 10 at Shore Memorial. Hospital in Nassawadox, Va. ...

36

Aircraft measurements of asymmetric temperature microstructure causing azimuth variations of VHF radar echo power  

British Library Electronic Table of Contents (United Kingdom)

VHF wind-profiling radars often measure a decrease of echo power with zenith angle, which can be explained from in situ measurements of horizontal layering or anisotropy of metre-scale temperature structure in the atmosphere. There can also be an azimuthal variation of echo power, which is increased in an azimuth opposite to the vertical shear vector of horizontal wind. This paper checks if the azimuth variation can also be linked to in situ observations of temperature structure, using aircraft flights in the tropopause region near a VHF radar. At heights where VHF radar measures wind shear and aspect sensitivity, there can be an asymmetry in the probability distribution of horizontal gradient of potential temperature, for horizontal scale of e.g. hundreds of metres. The asymmetry is often...

2007-01-01

37

A Great Day to Go Flying  

Science.gov (United States)

but one test point on the flight cards was achieved before we hit our "bingo," or minimal fuel remaining, and we had to land. The radar was developed by NASA's Jet Propulsion...

2011-10-07

38

Wind energy mapping of coastal zones by synthetic aperture radar (SAR) for siting potential windmill locations  

Energy Technology Data Exchange (ETDEWEB)

The authors propose using synthetic aperture radar(SAR) for wind energy mapping of coastal zones. The SAR equipment is located on the European Space Agency ERS-1 and 2 and the RADARSAT satellites. Examples of wind energy maps and evaluations of their applications are given for the Norwegian west coast.

2000-07-01

39

Microwaves - the hidden danger. Mikrowellen - die verheimlichte Gefahr  

Energy Technology Data Exchange (ETDEWEB)

Today, highly frequent radio waves are regarded as undangerous to man. Diseases seen at radar-technicians during the 2nd World War, however, indicated that microwaves applied in radar systems were hazardous to health. The Russian work medicine has been knowing microwave-caused hazards in industry since the beginning of the thirties. Therefore in some East-European countries there are terms of protection and severe norms of safety for the staying of persons in the radiation sphere of microwaves.

1987-01-01

40

Asynchronous Digital Regulators  

Science.gov (United States)

... (tb*it 06(M WfIio[td) Page 2. Asynchronous Digital Regulators Vernon Scott Ritchey, Ph.D. ... Page 3. ASYNCHRONOUS DIGITAL REGULATORS ...

2011-05-13

41

7.5 Minute Hypsography for Timber Knob, CA  

Science.gov (United States)

(USGS Text) Digital line graph (DLG) data are digital representations of cartographic information. DLGs of map features are converted to digital form from ... ...

43

Application of photogrammetry, remote sensing and GIS in the environmental monitoring of the Deutsche Steinkohle AG; Einsatz von Photogrammetrie, Fernerkundung und GIS im Umweltmonitoring der Deutschen Steinkohle AG  

Energy Technology Data Exchange (ETDEWEB)

Due to legal restrictions, the German hard coal mining company Deutsche Steinkohle AG (DSK) is obliged to conduct a monitoring on surface changes (subsidence) caused by mining activity (e.g. topographic surface, groundwater, water, flora and fauna, soil). To fulfill legal demands and to do this effectively, process chains by use of Photogrammetry, Remote Sensing and Geo-Informationssystems (GIS) have been established. Photogrammetric methods are used to generate high resolution Digital Elevation Models (DEM) from which in combination with subsidence data geometrical changes at the topographic surface are deduced. The potential use of active sensors (Laser Scanning and Synthetic Aperture Radar Systems) to deduct DEM has been investigated. The applicability of SAR satellite data to detect and observe subsidence and resulting movements - point wise or with spatial extent - using differential SAR Interferometry (dInSAR) as well as persistent ...

2006-03-15

44

Intelligent Analyst Digital Video Library Prototype  

Science.gov (United States)

... type. Sonic's digital libraries will provide a cross mapping between the narrative (speech and text) and imagery domains. ...

2002-10-01

45

High-throughput screening of microscale pitted substrate topographies for enhanced nonviral transfection efficiency in primary human fibroblasts  

British Library Electronic Table of Contents (United Kingdom)

Optimization of nonviral gene delivery typically focuses on the design of particulate carriers that are endowed with desirable membrane targeting, internalization, and endosomal escape properties. Topographical control of cell transfectability, however, remains a largely unexplored parameter. Emerging literature has highlighted the influence of cell-topography interactions on modulation of many cell phenotypes, including protein expression and cytoskeletal behaviors implicated in endocytosis. Using high-throughput screening of primary human dermal fibroblasts cultured on a combinatorial library of microscale topographies, we have demonstrated an improvement in nonviral transfection efficiency for cells cultured on dense micropit patterns compared to smooth substrates, as verified with flow...

2011-01-01

46

A Combinatorial Library of Micro-Topographies and Chemical Compositions for Tailored Surface Wettability  

British Library Electronic Table of Contents (United Kingdom)

Abstract Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X-=-1-m and...

2011-01-01

47

The Surface Water and Ocean Topography (SWOT) - NASA  

Science.gov (United States)

The ratio of particle velocity to translation speed exceeds 1 for 98% of .... The westward movement of the meandering jet and eddy system transports nutrient- rich ...... J. Hydrometeor., 4, 1044-1066. Gedney, N., P. M. Cox, H. Douville, ...

48

Signal and imaging sciences workshop proceedings  

Energy Technology Data Exchange (ETDEWEB)

Papers are presented in the areas of: Medical Technologies; Non-Destructive Evaluation; Applications of Signal/Image Processing; Laser Guide Star and Adaptive Optics; Computational Electromagnetic, Acoustics and Optics; Micro-Impulse Radar Processing; Optical Applications; TANGO Space Shuttle.

1997-11-01

49

Measurements of Spectral Characteristics of Swimmer Targets ...  

Science.gov (United States)

... 3.0 Radar Measurements 3-1 3. 1 Spectral Density Measurements 3-2 3. 1. 1 System Calibration 3-3 ... 3. 1 SPECTRAL DENSITY MEASUREMENTS ...

1974-05-01

50

Identification of a distant cis-regulatory element controlling pharyngeal arch-specific expression of zebrafish gdf6a/radar  

UK PubMed Central (United Kingdom)

Skeletal formation is an essential and intricately regulated part of vertebrate development. Humans and mice deficient in Growth and Differentiation Factor 6 (Gdf6) have numerous...Full Text Available

2010-04-01

51

Earth Resources NASA SP-7041 (18) - NASA Technical Reports Server  

Science.gov (United States)

The Grover S and X-band dual-wavelength radar system has been ...... A. H. Watkins (U.S. Geological Survey, Earth Resources. Observation Systems Data Center ...

52

Cytokine signalling in rat pulp interstitial fluid and transcapillary fluid exchange during lipopolysaccharide-induced acute inflammation  

UK PubMed Central (United Kingdom)

The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid...Full Text Available

2006-05-15

53

Cell behaviour on chemically microstructured surfaces  

Energy Technology Data Exchange (ETDEWEB)

Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical ...

2003-03-03

54

Digital Audio Sampling for Film and Video.  

Science.gov (United States)

Digital audio sampling is explained, and some of its implications in digital sound applications are discussed. Digital sound equipment is rapidly replacing analog recording devices as the state-of-the-art in audio technology. The philosophy of digital recording involves doing away with the continuously variable analog waveforms and turning the patterns into numbers. A digital recording device rapidly samples the incoming sounds, quantifying the signal into a series of numerical values (binary codes). Although digital sound eliminates many of the traditional analog problems, digital signal processing presents key problems in sampling rates and synchronization. Careful control is necessary to check signals through each step in the audio chain. The advantages of digital audio processing include increased signal-to-noise ...

1993-03-01

55

The Possibility of Digital Imaging in the Diagnosis of Occlusal Caries  

UK PubMed Central (United Kingdom)

The aim of this study was to assess the possibility of digital image analysis of pit-and-fissure discoloration in order to diagnose caries. Digital images showing pit-and-fissure discoloration in 100...Full Text Available

2010-01-01

56

Self-Study Digital Library Courseware  

Science.gov (United States)

Tutorial on digital libraries. Site also contains links to other reference materials on digital libraries as well as links to courses on the subject. Keywords: Information Systems - Information Systems Applications, Information Storage and Retrieval, Database Management, multimedia

2001-12-01

57

Clinical Digital Libraries Project: design approach and exploratory assessment of timely use in clinical environments*  

UK PubMed Central (United Kingdom)

Objective: The paper describes and evaluates the use of Clinical Digital Libraries Project (CDLP) digital library collections in terms of their facilitation of timely clinical information...Full Text Available

2006-04-01

58

A System for the Recording of Clinical Data as an Aid in the Diagnosis of Bovine Digital Disease  

UK PubMed Central (United Kingdom)

A form for the clinical evaluation of bovine digital disease was developed. In this article, each section of the resulting Digit Evaluation Form is discussed and justified. By following the...Full Text Available

1986-08-01

59

Digital AVR application to power plants  

Energy Technology Data Exchange (ETDEWEB)

The digital AVR must have the level of redundancy and control functions that conform to the configuration of the excitation control system and to the importance of a particular generator for the user. The digital AVR is not simply a digital version of the analog AVR, but can realize sophisticated control functions that were difficult to achieve with analog circuits, thus making it possible to enhance the stability of power system by PSS (power system stabilizer). This paper describes the test results of the digital AVRs applied to power plants, their system configuration and functions, as well as the outline of an auto-tuning PSS or AT-PSS planned to be incorporated in the digital AVR in the future.

1993-12-01

60

''SEPIO NUANCE DT'' digital mammography system  

International Nuclear Information System (INIS)

In the past, the need for high quality images, i.e., very sharp and clear images, in mammography have prevented mammography equipment from being digitalized; however, recent advances in detection technology such as development of a high resolution digital X-ray detector have produced improvements in digital mammography. Digital mammography is expected to replace conventional film-screen mammography. We have developed a digital mammography system, named ''SEPIO NUANCE DT'', which is equipped with a direct conversion flat panel detector. The present paper describes the high basic performance and user-friendly functions of the system. (author)

2007-03-01

61

Real-time digital libraries based on widely distributed, high performance management of large-data-objects  

CERN Document Server

Real-time digital libraries based on widely distributed, high performance management of large-data-objects

1997-01-01

62

Internet and Electronic Information Management  

Science.gov (United States)

... 6(2): 36-45. Hedstrom, M. (1998). Digital preservation: a time bomb for digital libraries. [Online]. Available: http://www.uky ...

2004-12-01

63

Digitizing Dissertations for an Institutional Repository: A Process and Cost Analysis*  

UK PubMed Central (United Kingdom)

Objective:This paper describes the Lamar Soutter Library's process and costs associated with digitizing 300 doctoral dissertations for a newly implemented institutional repository...Full Text Available

2008-07-01

64

Digital Hearing Aids: Current "State-of-the-Art"  

Science.gov (United States)

... promise of highly advanced signal processing, ensured that digital hearing aid technology had come of age. So how far have ...

65

Usability Studies and User-Centered Design in Digital Libraries  

Science.gov (United States)

Digital libraries continue to flourish. At the same time, the principles of user-centered design and the practice of usability testing have been growing in popularity, spreading their influence into the library sphere. This article explores the confluence of these two trends by surveying the current literature on usability studies of digital libraries. This article focuses on the methodology of studies of multimedia digital libraries. (Contains 1 table and 45 notes.)

2007-12-01

69

Using ERS-2 SAR images for routine observation of marine pollution in European coastal waters  

Energy Technology Data Exchange (ETDEWEB)

More than 660 synthetic aperture radar (SAR) images acquired over the southern Baltic Sea, the North Sea, and the Gulf of Lyon in the Mediterranean Sea by the Second European Remote Sensing Satellite (ERS-2) have been analyzed since December 1996 with respect to radar signatures of marine pollution and other phenomena causing similar signatures. First results of our analysis reveal that the seas are most polluted along the main shipping routes. SAR images acquired during descending (morning) and ascending (evening) satellite passes show different percentages of oil pollution, because most of this pollution occurs during night time and is still visible on the SAR images acquired in the morning time. Moreover, we found a higher amount of oil spills on SAR images acquired during summer (April-September) than on SAR images acquired during winter (October-March). We attribute this finding to the higher mean wind speed encountered in all three test ...

1999-09-30

70

The German Army and its management of hazards and hazardous substances. Report of the working group Dr. Sommer  

International Nuclear Information System (INIS)

This report primarily deals with three issues: the health consequences of the use of ammunition with depleted uranium cores; the health damage that radar staff may have suffered through stray X-radiation; and the way hazardous materials such as asbestos are handled in the German army. As regards uranium ammunition, the present findings suggest that there is neither reason for concern nor blame on anyone. The 31,000 American DU rounds that were fired over Kosovo in 1999 neither pose a health hazard to soldiers nor to the civil population. All that remains is a minimal risk of future groundwater contamination. The radar equipment currently in use in the German army poses no danger to operators, inspectors, service personnel or instructors provided that the relevant safety rules are observed. However, this cannot be said with the same degree of certainty with regard to the equipment used in the 1960s and 1970s. It is quite possible that ...

71

GeoSAR program: IFSAR validation and terrain classification from polarimetry  

Science.gov (United States)

The GeoSAR (geographic synthetic aperture radar) program is a Defense Advanced Research Projects Agency (DARPA) sponsored program organized in cooperation with the Jet Propulsion Laboratory (JPL) and the California Department of Conservation. Some aspects of the program have been existent for almost two years. The technical goal of the program has been the development of rapid-mapping radar technologies, and has now, as its principal challenge, the development of a capability for terrain mapping under foliage. In this paper, we discuss validation of current technology and examine the utility of data products currently produced by the Environmental Research Institute of MIchigan's (ERIM) IFSARE, JPL's TOPSAR, and JPL's AIRSAR. We find that ERIM's X-band IFSARE system produces elevation maps to better than 2-m accuracy. Based on this we determine that TOPSAR elevation maps are accurate to at least 5 m. We also demonstrate the utility of JPL's ...

1996-06-01

72

Algorithmic aspects and supercomputing trends in computational electromagnetics  

Energy Technology Data Exchange (ETDEWEB)

Accurate and rapid evaluation of radar signature for alternative aircraft/store configurations would be of substantial benefit in the evolution of integrated designs that meet RCS requirements across the threat spectrum. Finite-volume time domain methods offer the possibility of modeling the whole aircraft, including penetrable regions and stores, at longer wavelengths on today's supercomputers and at typical airborne radar wavelengths on the teraflop computers of tomorrow. A structure-grid finite-volume time domain CFD based RCS code has already been developed at the Rockwell Science Center, and this code incorporates modeling techniques for general radar absorbing materials and structures. Using this work as a base, the goal of the CFD based CEM effort is to define, implement, and evaluate various code development issues suitable for rapid prototype signature prediction addressing many issues related to physics ...

1993-01-01

73

Digitization of past question papers, dissertations and theses: A case study of 30 Nigerian university libraries  

British Library Electronic Table of Contents (United Kingdom)

SummaryThis paper evaluates the status of digitization in 30 Nigerian university libraries with a view to identifying the status, progress, prospects and challenges to digitize library materials and form the basis of providing a roadmap to successful execution of digitization projects. The study assessed the status of digitization of past question papers, theses and dissertations in Nigerian university libraries from May to September 2006 through a self-administered questionnaire, site visits and interviews. It was found that, though there are automation services in those universities, there is no digitization of these materials mentioned in the surveyed institutions. The major obstacles militating against digitizing in the university libraries include lack of funds, lack of appropriate fa...

2007-01-01

74

Giving voice to the past: digitizing oral history  

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to describe the processes and procedures utilized by Jacksonville State University's Houston Cole Library to digitize an oral history collection and provide access to it through the Library's catalog, web presence, and the state-wide digital repository initiative, Alabama Mosaic (see www.alabamamosaic.org). Design/methodology/approach - The paper is based on the Library's experiences in acquiring, digitizing, creating metadata for and making accessible a collection of oral histories. Findings - The paper describes the obstacles overcome, issues encountered, procedures established, and ramifications of the project. Practical implications - Many institutions are currently digitizing unique collections as part of repository initiatives, both institutiona...

2009-01-01

75

Studies on Cercariae from Kuwait Bay. X. Description and surface topography of Cercaria kuwaitae X sp. n. (Digenea: Renicolidae).  

Science.gov (United States)

A new renicolid cercaria, Cercaria kuwaitae X sp. n., from the prosobranch gastropod Cerithium scabridum from Kuwait Bay is described. The new cercaria is nonstyleted gymnocephalous with voluminous Y-shaped excretory vesicle, flame cell formula 2[(3 + 3 + 3) + (3 + 3 + 3)] = 36, and without caudal fins. Surface topography of the new cercaria is studied by scanning electron microscopy. Domed papillae are abundant on the anterior and lateral aspects of the body, ciliated papillae are sparse dorsally. The ventral sucker bears nine domed papillae. Domed papillae form two circles around the oral sucker with three circles of spines in between. This is the first renicolid cercaria to be recorded in a gastropod from the Arabian Gulf region. PMID:9789783

1997-12-01

76

GIS for combined storage and analysis of data from terrestrial and synthetic aperture radar remote sensing deformation measurements in hard coal mining  

British Library Electronic Table of Contents (United Kingdom)

In this paper we demonstrate the capabilities of our ArcGIS-based software development that includes an adapted database system and a GIS tool for storage, combined analysis and visualization of leveling data and interferometric synthetic aperture radar (SAR) deformation measurements. Preprocessed remote sensing image data are stored with metadata that include all processing routines and parameters. This allows reproduction and traceability of all processing steps. Deformation monitoring is supported through data searching and selection based on a variety of criteria. A methods toolbox allows spatio-temporal analyses for points, lines and areas (e.g. subsidence basins) in a graphical manner.

2011-01-01

77

A wave effect enabling universal frequency scaling, monostatic passive radar, incoherent aperture synthesis, and general immunity to jamming and interference  

CERN Document Server

A fundamental Doppler-like but asymmetric wave effect that shifts received signals in frequency in proportion to their respective source distances, was recently described as means for a whole new generation of communication technology using angle and distance, potentially replacing TDM, FDM or CDMA, for multiplexing. It is equivalent to wave packet compression by scaling of time at the receiver, converting path-dependent phase into distance-dependent shifts, and can multiply the capacity of physical channels. The effect was hitherto unsuspected in physics, appears to be responsible for both the cosmological acceleration and the Pioneer 10/11 anomaly, and is exhibited in audio data. This paper discusses how it may be exploited for instant, passive ranging of signal sources, for verification, rescue and navigation; incoherent aperture synthesis for smaller, yet more accurate radars; universal immunity to jamming or interference; and precision frequency scaling of ...

2008-01-01

78

1982 International Geoscience and Remote Sensing Symposium, Munich, West Germany, June 1-4, 1982, Digest. Volumes 1 and 2  

Energy Technology Data Exchange (ETDEWEB)

Theoretical and experimental data which have defined and/or extended the effectiveness of remote sensing operations are explored, with consideration given to both scientific and commercial activities. The remote sensing of soil moisture, the sea surface, and oil slicks is discussed, as are programs using satellites for studying geodynamics and geodesy, currents and waves, and coastal zones. NASA, Canadian, and Japanese radar and microwave passive and active systems are described, together with algorithms and techniques for image processing and classification. The SAR-580 project is outlined, and attention is devoted to satellite applications in investigations of the structure of the atmosphere, agriculture and land use, and geology. Design and performance features of various optical scanner, radar, and multispectral data processing systems and procedures are detailed.

1982-01-01

79

Topological modeling of the reactive capacity and biological activity of some amino-polysaccharides  

British Library Electronic Table of Contents (United Kingdom)

The work is devoted to a microscopic analysis of the reactive capacity of chitin. An algorithm for modeling the deacetylation reaction in a monomeric unit of chitin is described. The reaction coordinate and the potential energy surface topography are determined taking into account the electron-vibrational interaction and low-symmetry perturbations within Jahn-Teller theory. Based on this algorithm, the topological modeling of the deacetylation process is performed for the first time and a mechanism of the biological activity of chitosan is proposed.

2011-01-01

80

Oil and the future: Taking bearings in the greenhouse in a post Brent Spar world  

Energy Technology Data Exchange (ETDEWEB)

The paper discusses future oil combustion. A greenhouse-related environmental driving-force seems set to emerge in the capital markets in the years ahead. This will severely compound other already serious environment-related financial problems blighting the oil-industry`s access to capital radar screen. The wise oil company is now, increasingly clearly, the company thinking about how to begin repositioning itself for the twenty-first century as a total energy company. 6 refs.

1995-12-31

81

Mission Science Calibration and Validation Plan - SMAP  

Science.gov (United States)

Nov 16, 2010 ... In situ observations are usually made point-wise and the problem in using ...... also discussion of adaptive filtering in Section 4.1.2 of the L4_SM ...... L2-SR -265 SMAP shall provide a Level 1C radar sigma-0 product ...

82

Microwaves (including RADAR) and radiation protection  

Energy Technology Data Exchange (ETDEWEB)

The Commission of the European Communities has submitted a directive for the protection against microwaves. According to this directive, exposures above the upper limit established for the protection of individuals and the general population are permissible only if the respective individuals are required to submit to occupational medical control. An introductory overview is presented giving information on microwaves, applied techniques and available protective means.

1981-02-01

83

A passion for physics  

Energy Technology Data Exchange (ETDEWEB)

This is an account of the initial struggles and subsequently successful career of a young woman growing up in prewar Australia with the overriding desire to become a physicist despite various problems and prejudices. The book provides first-hand accounts of wartime radar research and development in Australia; the immediately post-war era in nuclear physics at the Cavendish Laboratory, Cambridge; and work in the Nuclear Physics Division at AERE Harwell in the period from the 1950s onwards. (UK).

1991-01-01

84

A combinatorial library of micro-topographies and chemical compositions for tailored surface wettability  

Energy Technology Data Exchange (ETDEWEB)

Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X = 1 {mu}m and an intermediate inter-pillar gap size of Y = 4 {mu}m with superhydrophobic CAs over 170 . Surface analysis with X-ray photoelectron spectroscopy (XPS) revealed ...

2011-06-15

85

Computer system for digitizing, analyzing and plotting well log data (a user's guide to WELLOG. Rev. 1)  

Energy Technology Data Exchange (ETDEWEB)

WELLOG is a system of programs developed at the Earth Science Laboratory to be used to digitize well logs and perform some analysis and plotting of the data. Multiple logs can be plotted side by side for correlation analysis and up to three logs can be plotted in a cross plot. Data entry and editing functions are also provided by the programs. This system of well log interpretation programs is presently operating on the University of Utah UNIVAC 1108 computer. Digitizing of well logs is accomplished by an old model CALMA (off-line) digitizer. Those parts of WELLOG that handle the digitized data tapes are extremely machine dependent. The parts of WELLOG that produce the plots and handle the data beyond the digitized data tape are more portable.

1980-03-01

86

Programma PLOT per l'esecuzione ed il confronto di grafici con l'RGL-library del VAX-11/780 Digital  

CERN Document Server

Programma PLOT per l'esecuzione ed il confronto di grafici con l'RGL-library del VAX-11/780 Digital

1985-01-01

87

Need for New Optimisation Strategies in CR and Direct Digital Radiography  

Energy Technology Data Exchange (ETDEWEB)

Digital imaging techniques such as Digital Image Intensifier Radiography and Digital Storage Phosphor (Selenium) Radiography are replacing conventional film-screen radiography more and more. The aim of this development is the extension of diagnostic capabilities and the reduction of side effects such as radiation dose. Conventional film-screen radiography and digital radiography are very different ways of imaging. For digital radiography specific post-processing is the link between imaging conditions and film documentation. Optimisation of the images includes new possibilities of post-processing and a broad range for variation of the dose. Especially in fluoroscopy, dose can be reduced significantly by new technical features like pulsed fluoroscopy. For digital radiography the European guidelines on quality criteria have to be applied to projection radiography, ...

2000-07-01

88

Need for New Optimisation Strategies in CR and Direct Digital Radiography  

International Nuclear Information System (INIS)

Digital imaging techniques such as Digital Image Intensifier Radiography and Digital Storage Phosphor (Selenium) Radiography are replacing conventional film-screen radiography more and more. The aim of this development is the extension of diagnostic capabilities and the reduction of side effects such as radiation dose. Conventional film-screen radiography and digital radiography are very different ways of imaging. For digital radiography specific post-processing is the link between imaging conditions and film documentation. Optimisation of the images includes new possibilities of post-processing and a broad range for variation of the dose. Especially in fluoroscopy, dose can be reduced significantly by new technical features like pulsed fluoroscopy. For digital radiography the European guidelines on quality criteria have to be applied to projection radiography, ...

1999-06-13

89

Digital versus conventional templating techniques in preoperative planning for total hip arthroplasty  

UK PubMed Central (United Kingdom)

BackgroundThe purpose of our investigation was to compare a digital templating system to conventional templating techniques when preoperatively planning for total hip arthroplasty.MethodsWe...Full Text Available

2009-02-01

90

Diagnostic quality of low resolution images for tele-woundcare.  

UK PubMed Central (United Kingdom)

The use of digital wound images would allow remote consultation between patients, physicians, or other caregivers over the Internet. To evaluate the efficacy and validity of digital images for assessment...Full Text Available

1998-01-01

91

Cost analysis of a project to digitize classic articles in neurosurgery*  

UK PubMed Central (United Kingdom)

In summer 2000, the Cushing/Whitney Medical Library at Yale University began a demonstration project to digitize classic articles in neurosurgery from the late 1800s and early 1900s. The objective of...Full Text Available

2002-04-01

92

Comparison of the quality of the chest film between digital radiography and conventional high kV radiography  

International Nuclear Information System (INIS)

Objective: To evaluate the quality and usefulness of direct digital radiography system in roentgenogram of chest in clinical practice. Methods: 1000 cases of chest roentgenograms with digital radiography and high kV conventional radiography were selected for analysis by 3 senior radiologists. Results: 1. With digital radiography system, the quality of chest film was assessed as grade A in 50.6%, grade B in 38.5%, grade C in 10.9%, and no waste film. 2. With conventional high kV radiography, the quality of chest film was assessed as grade A in 41.1%, grade B in 44.1%, grade C in 13.3%, and waste film in 1.5%. The direct digital radiography was statistically superior to the conventional high kV radiography. 3. The fine structure of the lungs could be revealed in 100.0% of chest roentgenogram with direct digital radiograph system, which was significantly higher than that acquired with ...

2003-02-01

93

Association of Unique, Isolated Treponemes with Bovine Digital Dermatitis Lesions?  

UK PubMed Central (United Kingdom)

This study used a PCR-based approach targeting 16S rRNA gene fragments to determine the occurrence and association of the three bovine digital dermatitis (BDD) treponeme phylogroups within lesions found...Full Text Available

2009-03-01

94

An Evaluation of Cellular Neural Networks for the Automatic Identification of Cephalometric Landmarks on Digital Images  

UK PubMed Central (United Kingdom)

Several efforts have been made to completely automate cephalometric analysis by automatic landmark search. However, accuracy obtained was worse than manual identification in every study. The analogue-to-digital...Full Text Available

2009-01-01

95

A Revised/Proposed Nomenclature for the External Anatomical Features of the Bovine Foot  

UK PubMed Central (United Kingdom)

Several widely recognized sources of nomenclature regarding the bovine external digit were reviewed, compared, and utilized in a clinical survey of bovine digital disease. During this process, some...Full Text Available

1988-05-01

96

A Comparison of intra-oral digital imaging modalities: Charged Couple Device versus Storage Phosphor Plate  

UK PubMed Central (United Kingdom)

BackgroundThis in vitro study was conducted to compare the accuracy of two digital image receptors in identifying the location of tip of a fine endodontic file and radiographic apex...Full Text Available

2010-11-01

97

Untitled - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Directional audio technology for headphone applications is being developed. A laboratory demonstration model of a real-time digital ...

99

The EMSL Collaboratory  

Science.gov (United States)

sharing data and computational resources, and accessing information in digital libraries." Bill Wulf (1989) In a Collaboratory, the presentation/meeting concept embodied...

2011-10-07

100

Technology in Coalition Training  

Science.gov (United States)

... program incorporates the proven concepts of advanced distributed learning, modeling and simulation, and electronic digital libraries (Figure 1) to ...

2004-06-01

101

Sheet1  

Science.gov (United States)

... 15, 14, Robert Constable, Cornell University, NY, Building Interactive Digital Libraries of Formal Algorithmic Knowledge, Navy. ...

103

Magnetic Tape Pulse Width to Digital Convertor.  

Science.gov (United States)

... This is achieved by the use of a unique logic circuit employing a plurality of flip-flop devices, multivibrators and AND gates. ...

1976-12-07

104

DVRPC 2010 Digital Orthoimagery - Mr.SID County Mosaics  

Science.gov (United States)

... image overlap between adjacent tiles. Orthoimagery processed by BAE Systems....

105

Considerations in the Design and Development of a Human ...  

Science.gov (United States)

... appropriate. At press time, the laws governing the use of digital audio technology and the technology itself are rapidly changing. ...

1990-09-20

106

Burned Timber Canyon  

Science.gov (United States)

The Digital Raster Graphic (DRG) is a raster image of a scanned USGS topographic map including the collar information, georeferenced to the UTM grid....

107

A solution to add digital signatures to medical images according to the DICOM standard: embedded systems  

International Nuclear Information System (INIS)

Radiology departments often underestimate the importance of protecting medical data during transmission, including the precautions taken to ensure data protection. In teleradiology, transmitted as well as stored patient data have to be signed digitally according to the currently valid regulation (Roentgenverordnung, RoeV). The DICOM standard facilitates a digital signature. So far, medical image manufacturers only announced to support this security feature. We introduce a solution that extends the feature of digital signing to older modalities. (orig.)

2005-01-01

108

A DIGITAL READOUT TECHNIC APPLICABLE TO ...  

Science.gov (United States)

... small. and hundreds decades. The outputs of both multivibrators are con- nected to an "and" circuit, which will put out 5 ...

1963-02-01

109

27 - NASA  

Science.gov (United States)

02.10.10 - NASA and Texas Instruments are using the theme of human space exploration to develop digital libraries of math and science problems for high ...

110

Recommending Related Papers Based on Digital Library Access Records  

CERN Document Server

An important goal for digital libraries is to enable researchers to more easily explore related work. While citation data is often used as an indicator of relatedness, in this paper we demonstrate that digital access records (e.g. http-server logs) can be used as indicators as well. In particular, we show that measures based on co-access provide better coverage than co-citation, that they are available much sooner, and that they are more accurate for recent papers.

2007-01-01

111

Digital Libraries from Concept to Practice  

CERN Document Server

The paper represents the result of research in the field of digital libraries functionalities in the context of new Grid infrastructure support. It is defined a new vector of knowledge society, informational vector - content vector. It presents a Grid European project which includes Romanian partners, and it defines on this base a digital library model which can be applied for the libraries in Romania.

2007-01-01

112

Evaluation of diagnostic digital radiography of the chest in comparison with conventional chest x-ray films  

International Nuclear Information System (INIS)

Digital radiography for diagnosis of chest diseases using Fuji Computed Radiography (FCR) was evaluated. The results were as follows; 1. Compared to the conventional chest X-ray films, various types of image enhancement could be made by manipulation of the digital information such as tone conversion, spatial frequency modification etc. 2. Digital radiography lessens the X-ray exposure dose and will ultimately permit speedy transmission of image data from outlying clinics to central processing hospitals. 3. Digital radiographic images are useful in chest X-ray diagnosis especially in mass surveys for lung cancer and in primary care medicine because of its full imaging capability. (author).

1983-01-01

113

Digital mammography: more microcalcifications, more columnar cell lesions without atypia  

British Library Electronic Table of Contents (United Kingdom)

The incidence of columnar cell lesions in breast core needle biopsies since full-field digital mammography in comparison with screen-filmed mammography was analyzed. As tiny microcalcifications characterize columnar cell lesions at mammography, we hypothesized that more columnar cell lesions are diagnosed since full-field digital mammography due to its higher sensitivity for microcalcifications. In all, 3437 breast core needle biopsies performed in three hospitals and resulting from in total 55?159 mammographies were revised: 1424 taken in the screen-filmed mammography and 2013 in the full-field digital mammography period. Between the screen-filmed mammography and full-field digital mammography periods, we compared the proportion of mammographies that led to core needle biopsies, the...

2011-01-01

114

The KSNPP risk-effect analysis of the digital safety-critical systems  

Energy Technology Data Exchange (ETDEWEB)

The study was performed for evaluating the risk effect of digital systems on the total plant. Based on risk monitor, a fault tree model for the Korean Standard Nuclear Power Plants (KSNPP), we integrate the fault-tree models for Digital Plant Protection System (DPPS) and Digital Engineered SaFety Actuation System (DESFAS) which are the most important safety-critical I and C systems in the KSNPP. In this study, however, three important factors (the probabilities of manual actuation failure, the software failure probability, and the watchdog timer fault coverage) are treated as the variables of the sensitivity study because quantification methodologies for these factors are not developed yet. Not only the unavailability of digital safety-critical system itself, but also the risk effect of digital systems on the total plant should be assessed to prove the safety of ...

2004-02-01

115

Reliability assessment of embedded digital system using multi-state function  

Energy Technology Data Exchange (ETDEWEB)

This work describes a combinatorial model for estimating the reliability of the embedded digital system by means of multi-state function. This model includes a coverage model for fault-handling techniques implemented in digital systems. The fault-handling techniques make it difficult for many types of components in digital system to be treated as binary state, good or bad. The multi-state function provides a complete analysis of multi-state systems as which the digital systems can be regarded. Through adaptation of software operational profile flow to multi-state function, the HW/SW interaction is also considered for estimation of the reliability of digital system. Using this model, we evaluate the reliability of one board controller in a digital system, Interposing Logic System (ILS), which is installed in YGN nuclear power units 3 and 4. Since the proposed ...

2006-03-15

116

Creating an EPICS Based Test Stand Development System for a BPM Digitizer of the Linac Coherent Light Source  

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) is required to deliver a high quality electron beam for producing coherent X-rays. As a result, high resolution beam position monitoring is required. The Beam Position Monitor (BPM) digitizer acquires analog signals from the beam line and digitizes them to obtain beam position data. Although Matlab is currently being used to test the BPM digitizer?s functions and capability, the Controls Department at SLAC prefers to use Experimental Physics and Industrial Control Systems (EPICS). This paper discusses the transition of providing similar as well as enhanced functionalities, than those offered by Matlab, to test the digitizer. Altogether, the improved test stand development system can perform mathematical and statistical calculations with the waveform signals acquired from the digitizer and compute the fast Fourier transform (FFT) of the signals. ...

2011-06-22

117

Synthetic aperture radar image of agricultural fields with surface drainage network: simulation and spatial information retreival  

Science.gov (United States)

We develop a 3-D model to simulate the synthetic aperture radar (SAR) image formation process of an undulated vegetation canopy such as corn grown in fields with large periodic drainage reliefs. We explain how the simulated SAR image of undulated vegetation medium is obtained by the convolution of a 2-D slice of the 3-D simulated SAR system point spread function [(PSF), emulating the SAR beam modeled by a cosine modulated Gaussian], with the 2-D projection of the observed undulated vegetation canopy (modeled with scatterers randomly distributed in 3-D undulated space) followed by the extraction of each look envelope, the summation of looks, and sampling in azimuthal and range directions. Our model is useful to study the parameters involved in the formation and the analysis of SAR images of undulated vegetation medium. Validation of simulations made with actual SAR images shows that undulated corn crop canopies are well characterized by the mean contrast of the ...

2001-10-01

118

One-class classifiers and their application to synthetic aperture radar target recognition  

Energy Technology Data Exchange (ETDEWEB)

Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. To function as a one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Columb Energy network (RCE). The ART 2-A neural network has given the best results, with 100% within-class, and out-of-class generalization. Experiments show that the network`s performance is sensitive to vigilance and number of training set ...

1992-10-01

119

Improved adhesion for thermoplastic polymers using oxyfluorination  

Energy Technology Data Exchange (ETDEWEB)

Industrial applications of thermoplastic polymers are often limited by their poor adhesion properties. In this work the effect of surface oxyfluorination on the adhesion properties was investigated for polyethylene (PE), polyoxymethylene (POM), polybutylene terephthalate (PBT) and polyamide 6 (PA6). The adhesive joint strength was quantified using lap-shear tests. These results were correlated with the changes in the chemical composition of the surface, determined by X-ray photoelectron spectroscopy (XPS), in the surface free energy, measured by the contact angle method, and in the topography, using white-light confocal microscopy. The adhesive strength is strongly improved for all four polymers, but the degree of this increase depends on the polymer type. The surface free energy shows a similar trend for all four polymers. A high surface free energy exceeding 50 mN/m was observed after oxy-fluorination, whereby the polar component was strongly predominant. Surface ...

2008-03-15

120

Hydrogen-plasticity interactions in pearlitic steel: a fractographic and numerical study  

Energy Technology Data Exchange (ETDEWEB)

A fractographic and numerical approach is presented to analyze hydrogen-plasticity interactions in pearlitic steel and to elucidate the main hydrogen transport mechanism in this material under triaxial stress states produced by notches. Fractographic analysis showed that the microdamage produced by the hydrogen was clearly detectable by scanning electron microscopy (SEM), through a specific microscopic topography associated with hydrogen effects (tearing topography surface or TTS). Numerical computations obtained by using an elastic-plastic finite element program gave the progressive spreading of the plastic zone, closely associated with the movement of dislocations. In the majority of cases, the plastic zone (PZ) clearly exceeds the hydrogen affected region (TTS) and has no relation with it. In some tests, however, the hydrogen-induced micro-damage surpasses the only region in which there is dislocation movement, and in this case the net ...

1996-11-30

121

Coal-mine-hazard detection using in-seam ground-penetrating-radar transillumination. Report of Investigations/1987  

Energy Technology Data Exchange (ETDEWEB)

The Bureau of Mines recently completed peliminary studies to demonstrate the feasibility of using Ground-Penetrating Radar (GPR) for in-seam hazard detection. Investigations included air and coal tests for the purpose of checking equipment accuracy, coal penetration, and other factors such as the effects of receiver orientation. Further investigations involved using both a short pulse and a new prototype synthetic-pulse system to locate a clay vein in a coal seam using transillumination. Data were gathered on multiple travel paths, and a back-projection processing technique was then used to create a tomographic image using the calculated velocities. A computer model of the same coal seam was subsequently processed using the same tomogrpahic technique, and the results were compared with those of the actual data. Results of these preliminary studies show that GPR is feasible for use in in-seam hazard detection and point the direction that future research should take.

1987-01-01

122

Rapid Tools for Joint Inversion and Imaging. Final report  

Energy Technology Data Exchange (ETDEWEB)

The activities and results of a Small Business Innovation Research Phase II project entitled ''Rapid Tools for Joint Inversion and Imaging'' are presented. Research and development on three-dimensional methods to recover distributions of material property values from sparse data are reported. Innovations using artificial neural networks and extended Kalman filtering are described. The report also covers investigations on upscaling and downscaling, segmentation for data processing, and applications to ground penetrating radar and geohydraulic tomography.

2000-08-02

123

Numerical simulation of trace tests in atmosphere in Daya Bay nuclear power site  

International Nuclear Information System (INIS)

The validation of the forecast model for early emergency response to nuclear accidents is evaluated by trace tests in atmosphere in Daya Bay nuclear power site. The simulation experiment of the Daya Bay nuclear power site shows that the particle spreading image and the time-integrated concentration distribution given by plume concentration prediction model can perform the variation of pathway of the pollutant transport, as well as the effects of topography on transport and diffusion of pollutants. The simulation of five trace tests in field shows that 59.1% of ratios between predicted results and observed results are within the range of 10, and 41% of ratios are within the range of 5 approximately. (authors)

2005-09-01

124

Micropulse Lidar (MPL) Handbook  

Energy Technology Data Exchange (ETDEWEB)

The micropulse lidar (MPL) is a ground-based optical remote sensing system designed primarily to determine the altitude of clouds overhead. The physical principle is the same as for radar. Pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is infered. Besides real-time detection of clouds, post-processing of the lidar return can also characterize the extent and properties of aerosol or other particle-laden regions.

2006-05-01

125

Grinding burn mechanism of directionally solidified superalloy  

Energy Technology Data Exchange (ETDEWEB)

Directionally solidified nickel-based superalloy DZ4 is an important structural material. However, the grinding burn occurs in grinding processes has hindered the grinding efficiency and dimensional accuracy. This paper investigates the grinding mechanism of this new type of superalloy based on the systematical analyses of variable characteristics of the grinding force, grinding temperature, topography of ground surface, hardness distribution of surface layer, as well as morphology of surface layer from a metallographical point of view. The results will be beneficial to grinding the superalloy with high efficiency and high precision. (orig.)

2001-07-01

126

Computer model of high-latitude scintillation. [WBMOD program  

Energy Technology Data Exchange (ETDEWEB)

The DNA Wideband satellite experiment provided extensive data on scintillation produced in high-altitude structured plasmas. A computer program, WBMOD, is being developed to summarize those data in an applications-oriented way. The program contains the phase-screen scattering theory of Rino and a morphological description of ionospheric irregularities (thus far only at auroral latitudes) based on Wideband observations. It permits a user to compute scintillation indices for both phase and intensity as a function of system operating parameters and solar-ionospheric disturbance level. Correction is made for multiple scatter, and the user may choose either one-way (communication) or two-way (radar) propagation.

1982-01-01

127

Computer model of high-latitude scintillation  

International Nuclear Information System (INIS)

The DNA Wideband satellite experiment provided extensive data on scintillation produced in high-altitude structured plasmas. A computer program, WBMOD, is being developed to summarize those data in an applications-oriented way. The program contains the phase-screen scattering theory of Rino and a morphological description of ionospheric irregularities (thus far only at auroral latitudes) based on Wideband observations. It permits a user to compute scintillation indices for both phase and intensity as a function of system operating parameters and solar-ionospheric disturbance level. Correction is made for multiple scatter, and the user may choose either one-way (communication) or two-way (radar) propagation.

128

Calculation of ice accumulation rates in Antarctica over the last glacial cycle.  

Environmental Research Database

DescriptionRates of ice accumulation in Antarctica are not known well, yet they are fundamental to assessing the ice sheet mass balance. Past accumulation rates are less well defined. We are in a unique position to provide detailed accounts of accumulation in Antarctica. We will measure isochronous internal layering across the ice sheet, which can be readily identified in radar data that we hold. Internal layers will be traced to ice-cores (allowing dating) and across wide regions of the ice sheets. A nume [continued...

2006-01-08

129

Surface expressions of subsurface structures in parts of the Michigan and Illinois basins  

Energy Technology Data Exchange (ETDEWEB)

Study of glacial geology, stream drainage, bedrock topography, and subsurface structure maps in Isabella, Midland, Arenac, Gladwin, Clare, Ogemaw, Iosco, Mecosta, and Montcalm counties in Michigan revealed distinct correlations between patterns and types of glacial deposits and subsurface structures. Anticlinal structures associated with the Mt. Pleasant, North Buckeye, and South Buckeye, Hamilton, Deep River, Clayton, Logan, Six Lakes, and West Branch oil and gas fields occur along areas where northeast-trending glacial moraines and truncated, attenuated, or deviated. Furthermore, these anticlinal structures are associated with lacustrine sands and gravels and glacial outwash deposits nearly surrounded by glacial tills or lacustrine sands and clays. All of the anticlinal structures are associated with bedrock topography highs and alignment of streams parallel to the trends of the structures. Comparison of images of subsurface structure and ...

1991-08-01

130

In situ scanning tunneling microscope study of the passivation of Cu(111)  

Energy Technology Data Exchange (ETDEWEB)

In situ scanning tunneling microscopy has been used to study the nucleation and growth mechanisms and the structure of passive films formed on Cu(111) surfaces in 0.1 M borate buffer solution (pH 9.3). A surface topography characterized by terraces with monoatomic steps is obtained after potentiodynamic reduction down to {minus}1.12 V/standard hydrogen electrode (SHE), of the electropolished surface exposed to air. The formation of a single Cu{sub 2}O passive layer at 0.03 V/SHE proceeds first by a roughening of the steps assigned to a locally blocked step flow process due to a competition between dissolution and preferential nucleation of the oxide at the steps. The observed oxide nuclei are 2--3 nm wide and about one atomic plane high. This process leads to the complete coverage of the terraces by a grain-like structure of the oxide film. The initial terrace topography is completely altered. Thickening of this oxide layer leads to unstable ...

1999-02-01

131

Evaluation of diagnostic ability of CCD digital radiography in the detection of incipient dental caries  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver Operating Characteristic) analysis and one way ANOVA test. The ...

2003-03-15

132

Evaluation of diagnostic ability of CCD digital radiography in the detection of incipient dental caries  

International Nuclear Information System (INIS)

The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver Operating Characteristic) analysis and one way ANOVA test. The ...

2003-03-01

133

Simulation of non-linear and switching elements for transient analysis based on wave digital filters  

Science.gov (United States)

A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.

1996-10-01

134

A navigation filter for fusing DTM/correspondence updates  

CERN Document Server

An algorithm for pose and motion estimation using corresponding features in images and a digital terrain map is proposed. Using a Digital Terrain (or Digital Elevation) Map (DTM/DEM) as a global reference enables recovering the absolute position and orientation of the camera. In order to do this, the DTM is used to formulate a constraint between corresponding features in two consecutive frames. The utilization of data is shown to improve the robustness and accuracy of the inertial navigation algorithm. Extended Kalman filter was used to combine results of inertial navigation algorithm and proposed vision-based navigation algorithm. The feasibility of this algorithms is established through numerical simulations.

2011-01-01

135

U.S. Department of the Interior Library - Reference Sources on...  

Science.gov (United States)

and Vendors on the Web Bartleby.com "Great books online." Electronic Texts & Digital Libraries Links to the full text of books and other texts on the Web. Law and Politics...

2011-05-06

136

Providing online access to historic films at the Washington State University libraries  

British Library Electronic Table of Contents (United Kingdom)

Purpose - This paper aims to discuss the procedures and methods developed at Washington State University to digitize and make accessible historic moving images. Design/methodology/approach - The paper describes the selection and the use of low-cost technologies to transfer analog film to digital formats. Issues related to the conversion, description, and online hosting of digital films are also addressed. Findings - Though the steps involved in digitizing film are not trivial, the benefits of access both for the public and archives staff outweigh the expense and labor involved. The procedures described in this paper involve low upfront costs and are sustained through cost recovery fees. Research limitations/implications - The focus of this paper is on managing, describing, and providing on...

2011-01-01

137

Photo Tours: Gulf of Mexico Integrated Science  

Science.gov (United States)

Inventory Project home page Reports, Posters, Presentations Internet Tools - Digital Libraries, IMS's Maps, Aerial Photographs Meetings & Conferences Photo Tours - all...

2011-10-08

138

NASA partners with teacher institute NASA strives to improve computers  

Science.gov (United States)

of the digital hearing aid technology that led to the cochlear implant. Former. Marshall Space Flight Center engineers. John Richardson and Joseph Howard ...

139

NASA Project Inducted Into Space Technology Hall of  

Science.gov (United States)

Apr 9, 2003 ... Adam Kissiah Jr., a retired KSC engineer, will be honored for his development of the digital hearing aid technology that led to the cochlear ...

140

Laser-assisted solar cell metallization processing - NASA ...  

Science.gov (United States)

Oct 15, 1985 ... Title: Laser-assisted solar cell metallization processing. No Digital Version Available: Go to Tips on Ordering ...

141

LCP-10 Intelligibility of Oxygen Masks and Microphones in ...  

Science.gov (United States)

... JTIDS) LPC-10 voice channel has been an important facet of a larger ongoing in-house research task on Digital Audio Technology for Aircraft ...

1988-10-24

142

Directory of Scientists: Gulf of Mexico Estuaries Integrated...  

Science.gov (United States)

Inventory Project home page Reports, Posters, Presentations Internet Tools - Digital Libraries, IMS's Maps, Aerial Photographs Meetings & Conferences Photo Tours - all...

2011-10-08

143

Conference on Information Technology (2nd)/Special Session ...  

Science.gov (United States)

... Topics includes: Formal methods in information engineering, Electronic documents and digital libraries Autonomous robots in embeded systems ...

2004-08-23

144

Concurrent Error-Detecting Codes for Arithmetic Processors  

Science.gov (United States)

2 is self-checking as described by Kolupaev. (ref. 21). ..... Kolupaev, S. G.: Self-Testing Residue. Trees. TR-49, Digital Systems ...

145

Center for Intelligent Information Retrieval  

Science.gov (United States)

evaluation, novelty detection, resource discovery, interfaces and visualization, digital libraries, computational social science, and cross-lingual information retrieval. The CIIR...

2011-08-31

146

Army Communicator. Volume 32, Number 2, Spring 2007  

Science.gov (United States)

... Introduction to the Signal Regiment Cisco Academy 1-4 (CCNA) Engineering Math Basic Electronics/Digital Logic (replaced C Programming ...

2011-05-14

147

A method of stereotaxic localization adopted for conventional and digital radiography  

International Nuclear Information System (INIS)

A method for the determination of stereotaxic coordinates in radiography, e.g. angiography, pneumoencephalography or digital vascular radiography, is described. A special localization frame containing radiopaque structures and scales defines a diagnostic coordinate system. This frame is fixed to the X-ray-table prior to the radiographic procedure and two projections are obtained at arbitrary angles to each other. The focus-film distances do not have to be fixed. The target coordinates are then determined either by a simple graphical procedure or with the use of a digitizing x-y-table, by a computer. With the computer method the films are placed on the digitizing table and the target and a few reference points are marked using a cursor. From the relative positions the computer calculates the coordinates. With the special head fixation system, coordinates of structures visualized in radiographic examinations can be ...

1986-01-01

148

Transbrachial arterial digital subtraction angiography  

International Nuclear Information System (INIS)

27 cases including 7 outpatients, underwent intraarterial DSA using 4-F nylon catheter, by transbrachial arterial approach. Much of DSAs were performed in Fuji Computed Radiography (FCR), which has high spatial resolution. In all cases, image quality satisfied clinical demands. No major complication occured in this series. Transbrachial arterial digital subtraction angiography is excellent and safe method for screening of vascular disease. (author).

1985-01-01

149

The power of digital audio in interactive instruction: An unexploited medium  

Energy Technology Data Exchange (ETDEWEB)

Widespread use of audio in computer-based training (CBT) occurred with the advent of the interactive videodisc technology. This paper discusses the alternative of digital audio, which, unlike videodisc audio, enables one to rapidly revise the audio used in the CBT and which may be used in nonvideo CBT applications as well. We also discuss techniques used in audio script writing, editing, and production. Results from evaluations indicate a high degree of user satisfaction. 4 refs.

1989-01-01

150

Proceedings of the 1st ACM international conference on digital libraries  

Energy Technology Data Exchange (ETDEWEB)

This document contains papers which were presented at the First ACM International Conference on Digital Libraries. Topics processed for this document included information retrieval and index structures for structured documents. Individual papers have been processed separately for the United States Department of Energy databases.

1996-12-31

151

Mammography: limits of a technique  

International Nuclear Information System (INIS)

Breast cancer represents today more than 30% of all cancers and is responsible for about 20% of deaths due to cancer. The potentialities of mammography have increased in recent years through improvements in equipment and methodologies. In this paper the conventional mammography using film and image intensifiers is compared with digital mammography. Digital mammography presents clear advantages in storage and handling of information. Also its higher sensitivity will lead to an earlier detection of anomalies and a decrease in the number of invasive exams and surgeries

2001-05-01

152

Impact of computers in radiography: the advent of digital radiography, part-2  

International Nuclear Information System (INIS)

Computed radiography (CR) systems use a photostimulable phosphor plate enclosed in a cassette. In CR, image acquisition is a two-stage process wherein image capture and image read out are done separately. Direct digital radiography (DR) systems, on the other hand, use detectors that have a combined image capture and image read out capability. DR systems are also called as DDR or ddR systems by some vendors. This article focuses on DR systems

2008-08-01

153

GaAs detector optimization for different medical imaging applications  

International Nuclear Information System (INIS)

We have investigated the detection performance of GaAs detectors made with different thickness and contact geometries. A comparison is made between these detection capabilities and the imaging requirements for the following medical applications: digital mammography, digital chest radiography and nuclear medicine. Experimental results and preliminary images are presented and discussed. (author)

1999-09-11

154

Experience with a digital noise analysis system in subcriticality measurements on a mockup of the FFTF  

Science.gov (United States)

From nuclear science symposium; San Francisco, California, USA (14 Nov 1973). A digital Fourier analyzer was programmed to perform reactor neutron noise analysis measurements and on-line processing of the data to obtain the steady-state reactivity. The system is suitable for recovering cross spectral density with low correlatedsignal component and for repetitive measurements with efficient use of reactor time. (auth)

1973-01-01

155

Evaluation of peripheral vascular disease by intravenous digital subtraction angiography with the Fuji computed radiography (FCR) system  

Energy Technology Data Exchange (ETDEWEB)

Intravenous digital subtraction angiography using Fuji computed radiography system (FCR-DSA) was used to evaluate 57 preoperative patients with clinical manifestations of peripheral vascular disease of lower extremity. With its high contrast resolution and good special resolution, image of FCR-DSA could offer optimal information of vascular abnormality in lower extremity distal to midfoot for the diagnosis and the choice of management.

1987-03-01

156

Evaluation of peripheral vascular disease by intravenous digital subtraction angiography with the Fuji computed radiography (FCR) system  

International Nuclear Information System (INIS)

Intravenous digital subtraction angiography using Fuji computed radiography system (FCR-DSA) was used to evaluate 57 preoperative patients with clinical manifestations of peripheral vascular disease of lower extremity. With its high contrast resolution and good special resolution, image of FCR-DSA could offer optimal information of vascular abnormality in lower extremity distal to midfoot for the diagnosis and the choice of management. (orig.).

1987-01-01

157

Digital signal processing for beam position feedback  

Energy Technology Data Exchange (ETDEWEB)

Stabilization of the particle beam position with respect to the focusing optics in the third generation synchrotron light sources is crucial to achieving low emittance and high brightness. For this purpose, global and local beam orbit correction feedbacks will be implemented in the APS storage ring. In this article, the authors discuss application of digital signal processing to particle/photon beam position feedback using the PID (proportional, integral, and derivative) control algorithm.

1992-04-01

158

Digital optical processing system  

Energy Technology Data Exchange (ETDEWEB)

Digital optical processing (DOP) was conceived to encompass the advantages of both electronic and optical processors, which are parallelism, flexibility, and high accuracy. The authors discuss the concept of parallelism, how it applies to DOP differently than to electronic parallel processing, and other potential advantages in using DOP. A PLZT memory device is described which can perform a series of logic or memory operations. From several of these PLZT devices a DOP is constructed to illustrate some of its programmability features.

1983-01-01

159

Automatically Generating Interfaces for Personalized Interaction with Digital Libraries  

CERN Document Server

We present an approach to automatically generate interfaces supporting personalized interaction with digital libraries; these interfaces augment the user-DL dialog by empowering the user to (optionally) supply out-of-turn information during an interaction, flatten or restructure the dialog, and enquire about dialog options. Interfaces generated using this approach for CITIDEL are described.

2004-01-01

160

Autocontrol technique of combined centrifuges  

International Nuclear Information System (INIS)

The design characteristic of the autocontrol technique of the combined centrifuge is introduced. Digital technique, vary structure control and interface technique, graphical display techniques, digital communication technique as well as electronic technique are applied in the course of research. Automation in the operation of large scale combined centrifuges and the course of combined test has been realized and it can coordinate with other systems of status monitoring, data collecting and centrifugal force-aerodynamic force matched load automatically

2009-12-01

161

A survey of surveys  

Energy Technology Data Exchange (ETDEWEB)

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.

1994-11-01

162

Mobile Computing in Digital Ecosystems: Design Issues and Challenges  

CERN Document Server

In this paper we argue that the set of wireless, mobile devices (e.g., portable telephones, tablet PCs, GPS navigators, media players) commonly used by human users enables the construction of what we term a digital ecosystem, i.e., an ecosystem constructed out of so-called digital organisms (see below), that can foster the development of novel distributed services. In this context, a human user equipped with his/her own mobile devices, can be though of as a digital organism (DO), a subsystem characterized by a set of peculiar features and resources it can offer to the rest of the ecosystem for use from its peer DOs. The internal organization of the DO must address issues of management of its own resources, including power consumption. Inside the DO and among DOs, peer-to-peer interaction mechanisms can be conveniently deployed to favor resource sharing and data dissemination. Throughout this paper, we show that most of the ...

2011-01-01

163

Digital direct magnification mammography with storage phosphor screens. Standardized and image result dependent post-processing parameters  

International Nuclear Information System (INIS)

Present day mammography has not been able to make use of the advantages of digital luminescence radiography because of the limited spatial resolution. The recent development of electromagnetic focusing X-ray tube with effective focal spot sizes from 0.04 to 0.12 mm allows radiographic direct magnification with less geometric blur. It is now possible to combine direct magnification mammography with digital luminescence radiography. By combining high quality storage phosphor screens with an HQ-workstation a spatial resolution of 8 lp/mm is possible for 1.7-fold magnification. For 4-fold spot magnification views spatial resolution can be theoretically increased to approx. 20 lp/mm. One important advantage of digital radiography is the possibility of image-postprocessing. This article presents two sets of standard parameters and three sets of image dependent parameters for better imaging of specific lesions, such as ...

164

Co-Authorship Networks in the Digital Library Research Community  

CERN Document Server

The field of digital libraries (DLs) coalesced in 1994: the first digital library conferences were held that year, awareness of the World Wide Web was accelerating, and the National Science Foundation awarded $24 Million (U.S.) for the Digital Library Initiative (DLI). In this paper we examine the state of the DL domain after a decade of activity by applying social network analysis to the co-authorship network of the past ACM, IEEE, and joint ACM/IEEE digital library conferences. We base our analysis on a common binary undirectional network model to represent the co-authorship network, and from it we extract several established network measures. We also introduce a weighted directional network model to represent the co-authorship network, for which we define $AuthorRank$ as an indicator of the impact of an individual author in the network. The results are validated against conference program committee ...

2005-01-01

165

Automated Categorization Scheme for Digital Libraries in Distance Learning: A Pattern Recognition Approach  

Science.gov (United States)

Digital libraries play a crucial role in distance learning. Nowadays, they are one of the fundamental information sources for the students enrolled in this learning system. These libraries contain huge amount of instructional data (text, audio and video) offered by the distance learning program. Organization of the digital libraries is therefore very important for easy and fast access to the desired information. Improper categorization of data may mislead the students searching the library. Since manual categorization of huge amount of data might be challenging, an automatic and reliable method is needed. In this sense, this paper proposes an automated categorization scheme for digital libraries in distance learning. The categorization scheme is designed and developed by a pattern recognition approach. Effectiveness of the proposed scheme is evaluated on widely used Reuters database. The results of the ...

2008-10-01

166

The use of combinatorial topographical libraries for the screening of enhanced osteogenic expression and mineralization  

British Library Electronic Table of Contents (United Kingdom)

Nano- and microstructured surfaces are known to impact on the binding and differentiation of cells, but the detailed basic understanding of the underlying regulatory mechanisms is still scarce, which impedes the rational design of smart biomaterials. Towards a comprehensive analysis of the interplay between topographical parameters such as feature design and lateral and vertical dimensions we here report on a combinatorial screening approach, BioSurface Structure Array (BSSA) of test squares each with a distinct topography. Using such BSSA libraries of 504 topographically distinct surface structures, we have identified combinations of size, gap and height of structures which enhance mineralization as well as the expression of osteogenic markers of a preosteoblastic murine cell line. This g...

2009-01-01

167

The surface topography of the choroid plexus. Environmental, low and high vacuum scanning electron microscopy  

British Library Electronic Table of Contents (United Kingdom)

Environmental scanning electron microscopy (ESEM) allows the examination of hydrated and dried specimens without a conductive metal coating which could be advantageous in the imaging of biological and medical objects. The aim of this study was to assess the performance and benefits of wet-mode and low vacuum ESEM in comparison to high vacuum scanning electron microscopy (SEM) using the choroid plexus of chicken embryos as a model, an organ of the brain involved in the formation of cerebrospinal fluid in vertebrates. Specimens were fixed with or without heavy metals and examined directly or after critical point drying with or without metal coating. For wet mode ESEM freshly excised specimens without any pre-treatment were also examined. Conventional high vacuum SEM revealed the characterist...

2011-01-01

168

The coexistence of fish species in streams: relationships between assemblage attributes and trophic and environmental variables  

British Library Electronic Table of Contents (United Kingdom)

Diet overlap and niche breadth are well-known species traits from trophic ecology that can assist in explaining how species interact and coexist as well as the ecological mechanisms that influence biodiversity. In the present study, we analyzed the relationships between these trophic variables and indicators of resource availability with some attributes of fish assemblages (species richness, Shannon diversity index, evenness, density and individual body size). The physical and chemical characteristics of the biotopes (topography, water quality and conservation of slopes) were examined to identify possible patterns. Monthly sampling using electrofishing was conducted in 2003 along five streams located in the Cuiab? River watershed. The relationships between environmental variables and attri...

2011-01-01

169

Satellite-based estimates of groundwater storage variations in large drainage basins with extensive floodplains  

British Library Electronic Table of Contents (United Kingdom)

This study presents monthly estimates of groundwater anomalies in a large river basin dominated by extensive floodplains, the Negro River Basin, based on the synergistic analysis using multisatellite observations and hydrological models. For the period 2003-2004, changes in water stored in the aquifer is isolated from the total water storage measured by GRACE by removing contributions of both the surface reservoir, derived from satellite imagery and radar altimetry, and the root zone reservoir simulated by WGHM and LaD hydrological models. The groundwater anomalies show a realistic spatial pattern compared with the hydrogeological map of the basin, and similar temporal variations to local in situ groundwater observations and altimetry-derived level height measurements. Results highlight th...

2011-01-01

170

Satellite remote sensing of Spratly Islands using SAR  

British Library Electronic Table of Contents (United Kingdom)

Spratly Islands, located in the southern part of the South China Sea (SCS), consist of more than 100 small islands, coral reefs and banks. Remote sensing is the only way to obtain a synoptic view of all of the islands in such a large area. It has been demonstrated that satellite synthetic aperture radar (SAR) imagery is a very powerful tool for monitoring meso-scale and small-scale ocean processes in a large area. In this study, satellite SAR images were used to study the ocean environment in the area of Spratly Islands. The aim was to understand the capability of satellite remote sensing to monitor ocean processes and provide information for future field studies. Two sets of high-resolution European Remote Sensing satellite (ERS)-2 SAR images over the entire Spratly Islands area were coll...

2008-01-01

171

Radiation protection - an overview of the concept for radiation protection at work and the concept for environmental radiation protection  

International Nuclear Information System (INIS)

This book gives an overview of the entire field of radiation protection with the subject areas radioactivity, X-rays, UV radiation, laser beams and high-frequency electromagnetic fields. It deals graphically with the most important physical notions, the incidence, origin, properties and biological effects of types of radiation, administrative and practical protection measures and the code of rules governing them. Apart from fundamentals of radiation protection the emphasis on the following: natural radiation exposure, radiation exposure to radon, disaster relief plans in the environment of nuclear plant, the precautionary radiation protection system evolved after Chernobyl, radiation exposure through UV radiation devices, radio, RF communication, radar, microwave ovens and high-voltage transmission lines as well as computer work-places. (orig.).

1993-01-01

172

Plan for addressing issues relating to oil shale plant siting  

Energy Technology Data Exchange (ETDEWEB)

The Western Research Institute plan for addressing oil shale plant siting methodology calls for identifying the available resources such as oil shale, water, topography and transportation, and human resources. Restrictions on development are addressed: land ownership, land use, water rights, environment, socioeconomics, culture, health and safety, and other institutional restrictions. Descriptions of the technologies for development of oil shale resources are included. The impacts of oil shale development on the environment, socioeconomic structure, water availability, and other conditions are discussed. Finally, the Western Research Institute plan proposes to integrate these topics to develop a flow chart for oil shale plant siting. Western Research Institute has (1) identified relative topics for shale oil plant siting, (2) surveyed both published and unpublished information, and (3) identified data gaps and research needs. 910 refs., 3 figs., 30 tabs.

1987-09-01

173

Mathematical modelling of air pollution in the Athens basin  

Energy Technology Data Exchange (ETDEWEB)

This paper presents research work concerning the mathematical modelling of air pollution in the Athens basin. A mathematical model based on aerodynamics and conservation equations together with turbulence modelling in body-fitted coordinates is used to provide the necessary input information to a similar but more detailed (i.e. small scale) model around Athens. Both models consist of solving the full Navier-Stokes equations and take into account the precise topography of the region. Different roughness heights are used for sea, coastal regions and land. The smaller scale model makes use of a two-equation turbulence model ({kappa}-{epsilon}) and the large scale model assumes a constant turbulence viscosity. The pollutant sources used in these models are based on actual emissions in the Athens area and are distributed in space. The results of this work appear promising and demonstrate the capability of the model as a tool for providing flow fields and pollution ...

1991-12-31

174

Lugworm exclusion experiment: Responses by deposit feeding worms to biogenic habitat transformations  

British Library Electronic Table of Contents (United Kingdom)

On six 400 m2 plots over 3 years, we excluded the sessile subduction and conveyer-belt feeding polychaete Arenicola marina which generates a pit-and-mound topography at the sediment surface from intertidal sands near the island of Sylt, Germany. This experiment was used to test whether other abundant deposit feeding polychaetes (the discretely motile and surface feeding ragworm Nereis diversicolor and the subsurface-feeding, motile orbiniid polychaete Scoloplos cf. armiger) benefit from competitive release. Ragworms took advantage from the absence of lugworms. Presumably they responded to a more stable and nutritious surface layer at lugworm exclusion plots (relief from inhibitive bioturbation). Contrary to this, S. cf. armiger was negatively affected by the exclusion of A. marina. It may ...

2006-01-01

175

Investigation of lattice strains in layered structures containing porous silicon  

International Nuclear Information System (INIS)

Silicon layered structures containing porous silicon modified with various thermal treatments and epitaxial layers deposited on porous layers were studied with a number of complementary X-ray diffraction methods using synchrotron source. The methods of characterization included recording of rocking curves for reflections with various asymmetry as well as projection, section and micro-Laue topography. It was found that oxidizing and sintering of porous silicon seriously modified the strains in the porous layer and in some cases even inverting the sense of strain with respect to that in initially formed porous layer. Consequently the deposited epitaxial layer usually was not laterally coherent with the substrate. Some of investigated layers were not stable in time and after few months period exhibited significant lost of coherence of porous skeleton. (author)

2001-09-23

176

Interpolating atmospheric water vapor delay by incorporating terrain elevation information  

British Library Electronic Table of Contents (United Kingdom)

In radio signal-based observing systems, such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR), the water vapor in the atmosphere will cause delays during the signal transmission. Such delays vary significantly with terrain elevation. In the case when atmospheric delays are to be eliminated from the measured raw signals, spatial interpolators may be needed. By taking advantage of available terrain elevation information during spatial interpolation process, the accuracy of the atmospheric delay mapping can be considerably improved. This paper first reviews three elevation-dependent water vapor interpolation models, i.e., the Best Linear Unbiased Estimator in combination with the water vapor Height Scaling Model (BLUE?+?HSM), the Best Linear Unbiased Es...

2011-01-01

177

Integrated method of RS and GPR for monitoring the changes in the soil moisture and groundwater environment due to underground coal mining  

British Library Electronic Table of Contents (United Kingdom)

Mining affects the environment in different ways depending on the physical context in which the mining occurs. In mining areas with an arid environment, mining affects plants? growth by changing the amount of available water. This paper discusses the effects of mining on two important determinants of plant growth?soil moisture and groundwater table (GWT)?which were investigated using an integrated approach involving a field sampling investigation with remote sensing (RS) and ground-penetrating radar (GPR). To calculate and map the distribution of soil moisture for a target area, we initially analyzed four models for regression analysis between soil moisture and apparent thermal inertia and finally selected a linear model for modeling the soil moisture at a depth 10?cm; the relative error o...

2009-01-01

178

Influence of sputtering parameters and nitrogen on the microstructure of chromium nitride thin films deposited on steel substrate by direct-current reactive magnetron sputtering  

International Nuclear Information System (INIS)

Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr_2N and CrN phases was observed when 30% and 40% N_2 were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.

2010-08-02

179

Formation of Cu2O Quantum Dots on SrTiO3 (100): Self-Assembly and Directed Self-Assembly  

Energy Technology Data Exchange (ETDEWEB)

Nanoscale islands of Cu2O have been synthesized on single-crystal SrTiO3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (OPA-MBE). Island growth location has been controlled by using an ex-situ Ga+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. Analysis of Cu2O dot growth on unmodified substrate regions revealed an evolution of dot size and array density. Atomic force microscopy studies show that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of islands. Islands initially formed in the FIB-generated surface topography and filled those features before nucleating on neighboring unmodified surface regions.

2006-11-09

180

Focused-ion-beam directed self-assembly of Cu_2O islands on SrTiO_3(100)  

International Nuclear Information System (INIS)

Nanoscale islands of Cu_2O have been synthesized on single-crystal SrTiO_3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (MBE). Island growth location has been controlled by using an ex situ Ga"+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex situ atomic force microscopy study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.

2004-06-21

181

Focused-Ion-Beam Directed Self-Assembly of Cu?O Islands on SrTiO3(100)  

Energy Technology Data Exchange (ETDEWEB)

Nanoscale islands of Cu?O have been synthesized on single crystal SrTiO? (100) substrates using oxygen plasma assisted molecular beam epitaxy (MBE). Island growth location has been controlled by using an ex-situ Ga? focused ion beam (FIB) to modify the growth surface in discrete locations prior to island sythesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex-situ AFM study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.

2004-06-21

182

Evapotranspiration estimation using the Landsat-5 Thematic Mapper image over the Gyungan watershed in Korea  

British Library Electronic Table of Contents (United Kingdom)

Even if there have been efforts to validate remote-sensing-based energy balance models, which provide evapotranspiration (ET) maps over a large spatial scale, few studies have been conducted to validate their performance in Korea. In this study, surface energy balance fluxes including ET were estimated and inter-compared with two different models using the Landsat-5 Thematic Mapper (TM) image over a watershed scale in Korea. While there were larger spatial discrepancies for net radiation, soil heat and sensible heat fluxes on a pixel-by-pixel basis between the two models, relatively smaller spatial discrepancies for the latent heat flux and daily ET were detected. The spatial discrepancies for the daily ET were larger in low topography and dense vegetation ranges. Despite the different par...

2011-01-01

183

Environmental hazards for pipelines in coastal regions/shore approaches  

Energy Technology Data Exchange (ETDEWEB)

Often oil/gas and other hydrocarbons discovered and produced offshore are transported to onshore facilities via submarine pipelines. The route of such pipelines traverses through coastal/shore approach regions. For a rational/economic design, safe installation and subsequent operation it is of utmost importance to review, evaluate and finalize various environmental hazard such as winds, waves, currents, seabed topography, seabed and sub-bottom soils, seabed erosion and soil accretion. This paper addresses the above described environmental hazards, their assessment and techniques to prepare design parameters which must be used for stability analysis, installation methods, long term operation and maintenance for the shore approaches. Additionally, various proven pipeline installation and stabilization techniques for the shore approach region are detailed. As case histories, three approaches installed in the Dutch North Sea are described.

1995-12-31

184

Electromagnetic fields - introduction to relevant issues  

International Nuclear Information System (INIS)

This introductory paper surveys potential sources of electric magnetic, and electro-magnetic fields. Various cases are discussed to exemplify the total frequency range: nuclear magnetic resonance tomography, high-voltage transmission lines, transformer stations, effect lighting balls, military transmitters, transmitter towers of the Postal Services and other operators, mobile radiotelephone equipment, large broadcasting transmitters, radar radiation, high-frequency heat therapy. There is evidence suggesting that electric, magnetic and electro-magnetic fields may possibly represent a certain nuisance or health hazard even at field strength occuring in equipment used for every-day-life purposes, with an emphasis on their possible actions and effects in children and adolescents. The author discusses, in conclusion, the aerial equipment ordinance issued by Lower Saxony. (Uhe).

1993-06-01

185

Effect of heat-induced disturbance on microbial biomass and activity in forest soil and the relationship between disturbance effects and microbial community structure  

British Library Electronic Table of Contents (United Kingdom)

An important aspect of ecosystem sustainability is the ability to withstand and recover from disturbance or stress. In this study, we investigated the effect of a heat-disturbance on soil microbial biomass, microbial activity in response to the addition of organic acid (malate), and microbial community structure in a laboratory experiment. The soils investigated were from a jarrah (Eucalyptus marginata) forest that had undergone rehabilitation following bauxite mining 12 years previously. Soils from a full factorial of two field treatments; contour ripping induced micro-topography (mound or furrow) and prior exposure to prescription fire (burnt or non-burnt), were sampled and found to exhibit treatment-dependent differences in soil biological and chemical properties. Exposure of soil micro...

2008-01-01

186

Analysis of Ground Deformation Detected Using the SBAS-DInSAR Technique in Umbria, Central Italy  

British Library Electronic Table of Contents (United Kingdom)

Ground deformation affecting the Umbria region (central Italy) in the 9-year period from 1992 to 2000 was investigated through multi-temporal Differential Synthetic Aperture Radar Interferometry (DInSAR). For the purpose, the Small BAseline Subset (SBAS) technique was adopted, which allows studying the temporal evolution of the detected deformation at two spatial scales: a low-resolution (regional) scale, and a full-resolution (local) scale. For the analysis, SAR data acquired by the European Remote Sensing (ERS-1/2) satellites along ascending and descending orbits were used. The detected deformation was analysed to investigate its relevance to geophysical, geomorphologic, and human-induced processes that may result in hazardous conditions to the population of Umbria. Low-resolution deform...

2009-01-01

187

An overview of physical and biogeochemical processes and ecosystem dynamics in the Taiwan Strait  

British Library Electronic Table of Contents (United Kingdom)

The Taiwan Strait is an important channel in the west Pacific Ocean transporting water and chemical constituents between the East China Sea and the South China Sea. Due to its complex bottom topography, alternating monsoon forcing and conjunction of several current systems [such as the Zhejiang-Fujian (Zhe-Min) Coastal Current, the Kuroshio intrusion and the extension of the South China Sea Warm Current], the physical and biogeochemical processes and ecosystem dynamics in the Taiwan Strait vary significantly both in space and in time. Our recent interdisciplinary studies, combining in situ and remote sensing observations with numerical modeling, allow us to address several important issues concerning the Taiwan Strait. The temporal and spatial variation of circulation in the Taiwan Strait ...

2011-01-01

188

A program for passively tracking a target using an array of sensors  

Energy Technology Data Exchange (ETDEWEB)

The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.

1993-01-01

189

A modular neural network for direction-of-arrival estimation of two sources  

British Library Electronic Table of Contents (United Kingdom)

This work addresses the problem of estimating the direction-of-arrival (DOA) of two sources using an array of sensors. This problem is mostly useful in radar applications, where we have few targets at each range bin. Super-resolution algorithms, such as maximum likelihood (ML) estimation and multiple signal classification (MUSIC), have been applied to this problem, but the former involves high computation efforts, while the later has poor estimation performance for coherent sources. In this work, we propose a DOA estimation network, named RBF-AML, which combines the approximated ML (AML) estimator and a radial basis function (RBF) neural network (NN). In the proposed RBF-AML network, the entire two dimensional DOA space is divided into multiple sectors covered by RBF experts. The AML funct...

2011-01-01

190

Imaging of reflection seismic and radar wavefields: Monitoring of steam-heated oil reservoirs and characterization of nuclear waste repositories  

Energy Technology Data Exchange (ETDEWEB)

A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the Cold Lake deposit. Simulations were performed during different phases of the steam stimulation process to examine the relation between reservoir properties and conditions with seismic ...

1994-12-31

191

Groundwater penetrating radar and high resolution seismic for locating shallow faults in unconsolidated sediments  

Energy Technology Data Exchange (ETDEWEB)

Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting ...

1993-12-31

192

Ground penetrating radar and direct current resistivity evaluation of the desiccation test cap, Savannah River Site  

Energy Technology Data Exchange (ETDEWEB)

The Savannah River Site (SRS) has a variety of waste units that may be temporarily or permanently stabilized by closure using an impermeable cover to prevent groundwater infiltration. The placement of an engineered kaolin clay layer over a waste unit is an accepted and economical technique for providing an impermeable cover but the long term stability and integrity of the clay in non-arid conditions is unknown. A simulated kaolin cap has been constructed at the SRA adjacent to the Burial Ground Complex. The cap is designed to evaluate the effects of desiccation on clay integrity, therefore half of the cap is covered with native soil to prevent drying, while the remainder of the cap is exposed. Measurements of the continuing impermeability of a clay cap are difficult because intrusive techniques may locally compromise the structure. Point measurements made to evaluate clay integrity, such as those from grid sampling or coring and made through a soil cover, may miss cracks, joints or ...

1996-04-01

193

Evaluation of methods to measure surface level in waste storage tanks: Second test sequence  

Energy Technology Data Exchange (ETDEWEB)

This report describes the results of a program conducted at the Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company (WHC) to identify alternative methods to measure the surface level in the waste tanks. This program examined commercially available devices for measuring the distance to a target. This is a continuation of a program started in FY93. In the first test sequence, tests were performed.on five devices to determine their applicability to measure the surface level in the waste tanks. The devices were the Enraf-Nonius{trademark} Model 872 Radar Gauge, the Enraf-Nonius{trademark} Model 854 Advanced Technology Gauge (ATG), the Stanley Tool Laser Measuring Device, the Robertshaw Inven-Tel{reg_sign} Precision Level Gauge, and the Micro Switch Model 942 Acoustic Sensor. In addition, discussions were held with several manufacturer representatives regarding other potential devices. The results of these tests were documented in a previous report. Two ...

1993-09-01

194

Metadata aggregation and "automated digital libraries": A retrospective on the NSDL experience  

CERN Document Server

Over three years ago, the Core Integration team of the National Science Digital Library (NSDL) implemented a digital library based on metadata aggregation using Dublin Core and OAI-PMH. The initial expectation was that such low-barrier technologies would be relatively easy to automate and administer. While this architectural choice permitted rapid deployment of a production NSDL, our three years of experience have contradicted our original expectations of easy automation and low people cost. We have learned that alleged "low-barrier" standards are often harder to deploy than expected. In this paper we report on this experience and comment on the general cost, the functionality, and the ultimate effectiveness of this architecture.

2006-01-01

195

LDL (Landscape Digital Library) a Digital Photographic Database of a Case Study Area in the River Po Valley, Northern Italy  

CERN Document Server

Landscapes are both a synthesis and an expression of national, regional and local cultural heritages. It is therefore very important to develop techniques aimed at cataloguing and archiving their forms. This paper discusses the LDL (Landscape Digital Library) project, a Web accessible database that can present the landscapes of a territory with documentary evidence in a new format and from a new perspective. The method was tested in a case study area of the river Po valley (Northern Italy). The LDL is based on a collection of photographs taken following a systematic grid of survey points identified through topographic cartography; the camera level is that of the human eye. This methodology leads to an innovative landscape archive that differs from surveys carried out through aerial photographs or campaigns aimed at selecting "relevant" points of interest. Further developments and possible uses of the LDL are also discussed.

2001-01-01

196

Fundamental concepts of digital image processing  

Science.gov (United States)

The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under ...

1983-03-01

197

Creating Virtual Collections in Digital Libraries: Benefits and Implementation Issues.  

Science.gov (United States)

Explicitly defining virtual collections in a digital library can benefit both users and contributors. This paper outlines the costs and benefits for defining virtual collections and describes an implementation of collection-level metadata in two digital libraries. Our work suggests that component repositories of NSDL would profit by describing their collection, and sub-collections, using a schema such as the one we implemented. This would enable NSDL to provide a rich, cross-linked hierarchy of virtual collections. By sharing collection-level, rather than item-level, metadata, collections would provide detailed resource information, presumably keeping most of their viewership, while NSDL would provide a broad description of resources.

2003-03-18

198

Characterizing errors in digital elevation models and estimating the financial costs of accuracy  

British Library Electronic Table of Contents (United Kingdom)

Digital topographic models are the foundation of more advanced modeling applications and ultimately inform planning and decision making in many fields. Despite this, the error associated with these models and derived attributes is commonly overlooked. Little attention has been given in the scientific literature to the benefits gained from having less error in a model or to the corresponding cost associated with reducing model error by choosing one product over another. To address these gaps in knowledge we evaluated the error associated with five digital elevation models (DEMs) and derived attributes of slope and aspect relative to the same attributes derived from LiDAR data. We also estimated the acquisition and processing costs per square kilometer of the five test models and the LiDAR m...

2010-01-01

199

A digitization and multimedia project at Quinnipiac University, Hamden, Connecticut, USA  

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to encourage other libraries to provide access to their own original content via the web. By way of case study, the process of identifying materials, scanning them and creating web access to original content will be explored. Design/methodology/approach - To implement a book digitization project, three major things need to be present. The library must own material that was published prior to 1923, making them safely out of copyright in the USA; the library needs access to server space on the web and the library needs to own scanning equipment. Findings - This project demonstrated that a library does not necessarily need to obtain grant funding to begin an effective and successful digitization program. It also revealed a few things that would improve t...

2007-01-01

200

United States Geological Survey (USGS) FM cassette seismic-refraction recording system  

Energy Technology Data Exchange (ETDEWEB)

In this two chapter report, instrumentation used to collect seismic data is described. This data acquisition system has two parts: (1) portable anolog seismic recorders and related ``hand-held-testers`` (HHT) and (2) portable digitizing units. During the anolog recording process, ground motion is sensed by a 2-Hz vertical-component seismometer. The voltage output from the seismometer is split without amplification and sent to three parallel amplifier circuit boards. Each circuit board amplifiers the seismic signal in three stages and then frequency modulates the signal. Amplification at the last two stages can be set by the user. An internal precision clock signal is also frequency modulated. The three data carrier frequencies, the clock carrier frequency, and a tape-speed compensation carrier frequency are summed and recorded on a recorded on a cassette tape. During the digitizing process, the cassette tapes are played back and the signals are ...

1988-12-31

201

Swift Science Center - HEASARC - NASA  

Science.gov (United States)

Apr 20, 2009 ... "YY" is the 2-digit filter identifier .... In our example you can see a point- like optical/UV source in each of the filters at the ... The "sigma" paramter gives the detection threshold in terms of Gaussian sigma. ...

202

Seismicity and Stress Changes Subsequent to Destress Blasting at the Galena Mine and Implications for Stress Control Strategies.  

Science.gov (United States)

Destress blasting is commonly used as a stress control technique at the Galena Mine, Wallace, Idaho, where the U.S. Bureau of Mines maintains a cooperative research program with the mine operators (ASARCO). A digital seismic array and an array of borehole...

1993-01-01

203

SEER Treatment Field Names, Edition Numbers, NAACCR Data Item Name,  

Science.gov (United States)

In addition, for breast cancer, a fifth field, Reconstruction--First Course is recorded. V.02.E Reconstruction--First Course (breast only) 1 digit These codes for these fields are included as Appendix C of this manual.

204

Robust parameter extraction for decision support using multimodal intensive care data  

UK PubMed Central (United Kingdom)

Digital information flow within the intensive care unit (ICU) continues to grow, with advances in technology and computational biology. Recent developments in the integration and archiving of these...Full Text Available

2009-01-28

206

Remote control monitoring - a review of the latest equipment  

Energy Technology Data Exchange (ETDEWEB)

This article reviews briefly a range of the latest monitoring and controlling equipment for use in coal mines. This includes pressure transmitters, shale/coal discriminator, nucleonic bunker level indicator, automatic steering and monitoring system, oscilloscope/multimeter, and microprocessor based digital display controllers. 1 fig.

1988-01-01

207

Perceptions of Library Staff Regarding Challenges of Developing Digital Libraries: The Case of an Iranian University  

Science.gov (United States)

Purpose: The present research aims to identify the difficulties and obstacles for developing digital libraries in the seven regional branches of Islamic Azad University (IAU), Iran, and to study the status of librarians' skills and education programmes at these institutions. Design/methodology/approach: The 40 individuals working in the regional branch libraries of IAU were surveyed by a questionnaire consisting of 34 questions, and the collected data were analysed using SPSS software (version 16). Findings: It was found that the most important difficulties are the lack of suitable equipment and untrained personnel (i.e. a lack of sufficient training programmes). Research limitations/implications: Because of the small number of participants, it is suggested that a larger scale study is carried out. It is also proposed that the suggestions made by the participants will be considered and implemented, based on the digital library (DL) developments ...

2010-12-01

208

Ontario Timber Inventory (OTI) Level-I Digital Data - NASA  

Science.gov (United States)

Abstract: Data currently available in the Ontario Timber Inventory include Canada ... Download 1:250 000 scale Ontario Timber Inventory data in Arc Export ...

209

No short-term effects of digital mobile radio telephone on the awake human electroencephalogram  

Energy Technology Data Exchange (ETDEWEB)

A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3} and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 {micro}s, the authors could not detect ...

1997-05-01

210

NASA Surfs the Skies Above Oahu, Hawaii  

National Aeronautics and Space Administration (NASA)

This flyover of the Hawaiian island of Oahu was made by draping Jan. 13, 2010, image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft over new ASTER Version 2 digital elevation data.

2011-10-17

211

McMaster PLUS: A Cluster Randomized Clinical Trial of an Intervention to Accelerate Clinical Use of Evidence-based Information from Digital Libraries  

UK PubMed Central (United Kingdom)

BackgroundPhysicians have difficulty keeping up with new evidence from medical research.MethodsWe developed the McMaster Premium...Full Text Available

2006-11-01

212

JAtlasView: a Java atlas-viewer for browsing biomedical 3D images and atlases  

UK PubMed Central (United Kingdom)

BackgroundMany three-dimensional (3D) images are routinely collected in biomedical research and a number of digital atlases with associated anatomical and other information have...Full Text Available

213

Integration of turbo-generator modules in digital transient network analyzer  

Science.gov (United States)

The behavior of a small power system consisting of two interconnected generators is simulated in real-time by a prototype Digital Transient Network Analyzer (TNA). The prototype Digital TNA consists of two Computational Modules and one I/O Module. The Modules communicate with each other through ribbon cables. Each Computational Module simulates one Turbo-Generator, its Transformer, its Governor, Exciter, and Power System Stabilizer Systems. The numerical integration is shared by two TMS320C30 DSPs at a step-size of 100 microseconds in real-time. The I/O module post-processes the state variables and presents selected information for analog display. The paper presents oscillograms from a test program which includes symmetry checks and behavioral checks against well known waveforms of hunting oscillations, synchronization out-of-phase torques, and subsynchronous resonance phenomena. The success of the Digital TNA depends on: ...

1994-05-01

214

Image Engine: an object-oriented multimedia database for storing, retrieving and sharing medical images and text.  

UK PubMed Central (United Kingdom)

This paper describes Image Engine, an object-oriented, microcomputer-based, multimedia database designed to facilitate the storage and retrieval of digitized biomedical still images, video, and text...Full Text Available

1993-01-01

215

Hardening at the design level  

International Nuclear Information System (INIS)

This talk sketches out the main parameters (technology, circuit design) that have an influence on the hardening of digital CMOS integrated circuits. For each technology the more common defects are mentioned. General design rules are proposed to prevent or limit those defects. (D.L.). 2 refs., 2 figs.

216

Digital Talking Books: Planning for the Future.  

Science.gov (United States)

Ever-changing audio technology requires that National Library Service NLS always be aware of developments and prepare carefully for any systematic changes that may be desired or required. Usefulness, cost effectiveness, thoughtful stewardship, and educate...

1998-01-01

217

Classification of hematologic malignancies using texton signatures  

UK PubMed Central (United Kingdom)

We describe a decision support system to distinguish among hematology cases directly from microscopic specimens. The system uses an image database containing digitized specimens from normal...Full Text Available

2007-10-01

218

Calcium gradients and buffers in bovine chromaffin cells.  

UK PubMed Central (United Kingdom)

1. Digital imaging and photometry were used in conjunction with the fluorescent Ca2+ indicator, Fura-2, to examine intracellular Ca2+ signals produced by depolarization of single adrenal chromaffin...Full Text Available

1992-05-01

219

Automatic scene-adaptive pattern removal  

Energy Technology Data Exchange (ETDEWEB)

A new method for removing periodic background patterns from pictures is presented. The basic spatial frequency composition of the pattern is determined from an estimate of the power spectrum of the picture. A digital restoration filter is then created from a modified version of the power spectrum. The method is extremely effective and can be automated.

1982-01-01

220

Acceptance testing in digital systems of mammography. Protocols applicability  

International Nuclear Information System (INIS)

Acceptance testing of mammographic imaging systems technical is the first approach in order to guarantee that mammograms will be achieved with the minimum radiation dose compatible with an image quality suitable for diagnose purposes. The aim of this study is to assess the practical applicability of different protocols in acceptance test of digital mammographic systems. This study has been carried out on the results of the acceptance tests of five flat panel digital mammographic systems. Parameters established in the systems technical specifications and those evaluated in the consulted protocols were tested. Due to the fact that the legislation in our country does not demand to consider a specific protocol, the results obtained were also compared considering different existing protocols. Results show discrepancies between manufacturers limiting values and those established in the protocols. Some parameters, such as the automatic exposure ...

221

A high-speed network for cardiac image review.  

UK PubMed Central (United Kingdom)

A high-speed fiber-based network for the transmission and display of digitized full-motion cardiac images has been developed. Based on Asynchronous Transfer Mode (ATM), the network is scaleable, meaning...Full Text Available

1994-01-01

222

Long-term preventive maintenance of instrumentation control equipment for PWR plants  

International Nuclear Information System (INIS)

Since the PWR plants in Japan have been operated more than 30 years, main instrumentation control equipment of analog systems has been renewed to digital control systems. Renewal works had to be done in short period within periodical inspection term and for several facilities. The Mitsubishi LTD group had been provided with these market needs by its digital control system (MELTAC-NplusR 3) applicable to main instrumentation control equipment for primary and secondary systems and had already finished the renewal for practical plants. (T. Tanaka)

2006-02-01

223

Implantation of an electronic system for real time neutron graphic images acquisition at the IPEN/CNEN Argonaut reactor  

International Nuclear Information System (INIS)

The aim of this work is the implantation and characterization of a neutron radiography system that uses an electronic device for attainment of images in real time, for its implementation in the nuclear research reactor Argonauta at IEN/CNEN (Nuclear Engineering Institute of the Brazilian Nuclear Energy Commission). The Electronic Imaging System in Real Time is composed by a scintillator screen for neutron, a video camera (CCD), a digital plate and a computer with specific computational programs for digital processing of the images. The System in installed real time is apt to carry through neutron radiography inspections of static and dynamic events of several types of samples. (author)

2004-04-01

224

IQARIS : a tool for the intelligent querying, analysis, and retrieval from information systems.  

Energy Technology Data Exchange (ETDEWEB)

Information glut is one of the primary characteristics of the electronic age. Managing such large volumes of information (e.g., keeping track of the types, where they are, their relationships, who controls them, etc.) can be done efficiently with an intelligent, user-oriented information management system. The purpose of this paper is to describe a concept for managing information resources based on an intelligent information technology system developed by the Argonne National Laboratory for managing digital libraries. The Argonne system, Intelligent Query (IQ), enables users to query digital libraries and view the holdings that match the query from different perspectives.

2002-04-26

225

HVDC cable design logic for digital computers  

Energy Technology Data Exchange (ETDEWEB)

The design of High-Voltage, Direct-Current transmission cables insulated with oil-impregnated cellulose paper is constrained by the maximum temperature and the maximum steady-state and transient stresses (voltage gradients) that the cable insulation can reliably withstand over the desired operating lifetime. Because the electrical stresses in the insulation are related in a very complex fashion to temperature, applied voltage and cable geometry, iterative techniques are required to compute the values of these stresses. Digital computers are ideally suited for these iterative techniques. This paper presents the principal equations and logic needed to develop suitable computer programs.

1992-10-01

226

Embedding Forensic Capabilities into Networks: Addressing Inefficiencies in Digital Forensics Investigations  

Energy Technology Data Exchange (ETDEWEB)

A typical incident response pits technicians against networks that aren't prepared forensically. [1, 2] If practitioners do consider collecting network forensic data, they face a choice between expending extraordinary effort (time and money) collecting forensically sound data, or simply restoring the network as quickly as possible. In this context, the concept of organizational network forensic readiness has emerged. This paper proposes a methodology for "operationalizing" organizational network forensic readiness. The methodology, and the theoretical analysis that led to its development, are offered as a conceptual framework for thinking about more efficient, proactive approaches to digital forensics on networks.

2006-08-01

227

Digital image intensifier radiography: first experiences with the DSI (Digital Spot Imaging); Moeglichkeiten der digitalen Bildverstaerkerradiographie am Beispiel des Digital Spot Imaging (DSI)  

Energy Technology Data Exchange (ETDEWEB)

We performed a comparative study of digitally and conventionally acquired images in gastrointestinal examinations. Radiation dose and spatial resolution were determined in a water phantom. In 676 examinations with either conventional or digital imaging (system: Diagnost 76, DSI) the number of images and the duration of the fluoroscopy time were compared. 101 examinations with digital as well as conventional documentation were evaluated by using 5 criteria describing the diagnostic performance. The entrance dose of the DSI is 12% to 36% of the film/screen system and the spatial resolution of the DSI may be better than that of a film/screen system with a speed of 200. The fluoroscopy time shows no significant difference between DSI and the film/screen technique. In 2 of 4 examination modes significantly more images were produced by the DSI. With exception of the criterion of edge sharpness, DSI yields a significantly inferior ...

1995-10-01

228

Computer system architecture. Second edition  

Energy Technology Data Exchange (ETDEWEB)

A register transfer language is used to present the basic concepts of computer hardware architecture. Material needed for understanding computer organisation, design, and programming is included. The various functional units of digital computers (central processor, microprogram control; arithmetic algorithms; input-output; and memory organisation), are examined. A basic computer is developed to demonstrate the components of computer hardware and software architecture. Parallel processing and multiprocessor systems are discussed. Numerous MSI and LSI digital functions are introduced with explanations of their characteristics. Cache memory and the hardware requirements for a memory management unit are covered.

1982-01-01

229

Broadband Local Area Network security monitoring--Magnovox CATV Systems Inc. Digital System Sentry product evaluation  

Energy Technology Data Exchange (ETDEWEB)

Use of a broadband Local Area Network (LAN) for transmission of classified and secure unclassified information requires monitoring capabilities which are sensitive to discrete segments of the network frequency spectrum. A viable monitoring system must be capable of detecting possible intrusion attempts or network malfunctions and alerting operating and security personnel. This report documents the results of an evaluation of the Magnavox CATV Systems Inc. Digital System Sentry software for network monitoring. Recommendations are made on its possible future role in broadband LAN security monitoring throughout the Nuclear Weapons Complex.

1991-01-01

230

Application of the digital waveform analysis to Bragg curve spectrometer  

International Nuclear Information System (INIS)

Energy and angular double-differential cross-section (DDX) data of fragment production reactions by neutrons or protons are very scarce due to experimental difficulties of fragment detection. We adopted a Bragg curve spectrometer (BCS), which is a gridded-ionization chamber that can identify fragments on the basis of the Bragg peak value. We have been developing the BCS for neutron and proton-induced reactions applying the digital waveform analysis technique to obtain better ability of particle discrimination than the analog electronic circuit. (T. Tanaka)

2004-11-01

231

rf system for the Los Alamos free-electron laser (FEL)  

Energy Technology Data Exchange (ETDEWEB)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 ..mu..s at a 1-pps rate. The phase and amplitude stability requirements are +-1/2/sup 0/, and +-1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, 10-..mu..s pulses. Each tube has delivered over 3.6-MW, ...

1983-01-01

232

rf system for the Los Alamos free-electron laser (FEL)  

International Nuclear Information System (INIS)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 #mu#s at a 1-pps rate. The phase and amplitude stability requirements are +-1/2_0, and +-1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, 10-#mu#s pulses. Each tube has delivered over 3.6-MW, 100-#mu#s ...

1983-03-21

233

Working paper on candidate mining sites for surface mining of western oil shales  

Energy Technology Data Exchange (ETDEWEB)

This report describes the selection of candidate surface mining sites for the development of oil shale resources in the western United States. The purpose of this study is to input the various scenarios into an economic mine model developed for underground oil shale mines in an earlier project. Site selection was a three-phase effort. Phase I consisted of a thorough review of available resource data, which resulted in a definition of surface mineable areas. Phase II was a detailed investigation of the regions identified in the initial phase. The end result of this task was a list of potential sites having favorable overburden, grade, shale thickness, and topography values. Phase III identified those sites from which a wide range of site specific parameters can be obtained for mine design and model testing purposes. This report describes the procedures used to obtain the candidate mining scenarios. Section 2.0 discusses the methodology used to determine candidate ...

1981-09-02

234

Wear properties of steel plasma nitrided at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

The wear behaviour of 722M24 (En40B) steel plasma nitrided at high temperatures for long durations was investigated. Under dry sliding and abrasive-containing lubricated conditions, the wear characteristics of the steel were studied as a function of load, time and white layer thickness. The white layer and the wear debris were characterized by X-ray diffraction. The topography of the wear surface was examined in a scanning electron microscope. The plasma nitriding process was carried out using a 20 kW plasma processing unit in cracked ammonia atmosphere. Treatment times of up to 100 h were employed with temperatures of 550, 570 and 590 C. Wear tests were performed with plasma nitrided AMS 6472 as the counterface material. The tests under abrasive-containing lubricated conditions were carried out with 10% carborundum powder 10 [mu]m in size in SAE-30 machine oil. The wear resistance of the steel was improved by plasma nitriding and the abrasive wear resistance of ...

1993-08-30

235

Turnover of texture in low rate sputter-deposited nanocrystalline molybdenum films  

International Nuclear Information System (INIS)

The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the target under oblique ...

1997-04-04

236

The Spratlys: Islands nowhere else? Energy resources as a conflict factor and co-operation factor in East Asia; Die Spratlys: Inseln im Nirgendwo? Energieressourcen als Konflikt- und Kooperationsfaktor in Ostasien  

Energy Technology Data Exchange (ETDEWEB)

In the contribution under consideration, the author reports on the energy resources as a conflict factor and co-operation factor in East Asia on the basis of the Spratly islands. The main aspects of this contribution are: topography of the Spratly islands; history and actual claims; evaluation of the claims; strategic significance of the islands; resources of oil and natural gas as a conflict factor; resources of oil and natural gas as a co-operation factor. The resources of oil and natural gas have intensified the conflict around the Spratly islands in the last few decades. Due to the unsettled situation relating to international law six countries could claim the potentially energy-rich area having a geo-strategic instrument of power. Due to a treaty and due to the new common research studies of the neighbouring countries a phase of stability can be expected. The increasing involvement of China in the international economic structures suggests a military solution ...

2006-07-01

237

The RF system for the Los Alamos free electron laser (FEL)  

International Nuclear Information System (INIS)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 #mu#s at a 1-pps rate. The phase and amplitude stability requirements are + or - 1/2"0, and + or - 1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, 10-#mu#s pulses. Each tube has delivered over 3.6-MW, ...

238

Surface Topography of 'Hotspot' Regions from a Single Cell SRF Cavity  

Energy Technology Data Exchange (ETDEWEB)

Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed the crystal structure surrounding the pits via crystal phase orientation mapping, while 3D profilometry gave information on the depth and size of the pits. In ...

2009-05-01

239

Optical Pattern Fabrication in Amorphous Silicon Carbide with High-Energy Focused Ion Beams  

International Nuclear Information System (INIS)

Topographic and optical patterns have been fabricated in a-SiC films with a focused high-energy (1 MeV) H"+ and He"+ ion beam and examined with near-field techniques. The patterns have been characterized with atomic force microscopy and scanning near-field optical microscopy to reveal local topography and optical absorption changes as a result of the focused high-energy ion beam induced modification. Apart of a considerable thickness change (thinning tendency), which has been observed in the ion-irradiated areas, the near-field measurements confirm increases of optical absorption in these areas. Although the size of the fabricated optical patterns is in the micron-scale, the present development of the technique allows in principle writing optical patterns up to the nanoscale (several tens of nanometers). The observed values of the optical contrast modulation are sufficient to justify the efficiency of the method for optical data recording using high-energy focused ...

2011-07-01

240

One-class classifier networks for target recognition applications  

Energy Technology Data Exchange (ETDEWEB)

Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. Many neural network pattern classifiers fail as one-class classifiers because they use open decision boundaries. To function as one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Coulomb Energy network (RCE). The ART 2-A neural network gives the best results, with 100% within-class, between-class, and ...

1993-01-01

241

Mid-latitude scintillation model. Technical report, 1 November 1985-31 October 1986  

Energy Technology Data Exchange (ETDEWEB)

Radiowave scintillation in the presence of ionospheric disturbances has the potential to disrupt numerous transionospheric radio and radar systems. This report describes development of a model characterizing the plasma density irregularities that produce scintillation in the naturally disturbed mid-latitude F layer. The model will be incorporated into Program WBMOD, which includes subroutines for computing both link geometry and scintillation indices, the latter by means of phase screen diffraction theory. Earlier versions of WBMOD, were based on extensive analysis of scintillation data collected in the auroral and equatorial zones in Wideband Satellite Mission. The model described herein is based on similarly extensive analysis of Wideband data from one mid latitude station and of data collected from HiLat satellite at another mid latitude station. The model describes irregularities at an effective height of 350 km that are isotropic across the geomagnetic field ...

1986-10-31

242

How cells tiptoe on adhesive surfaces before sticking  

CERN Document Server

Cell membranes are studded with protrusions that were thoroughly analyzed with electron microscopy. However, the nanometer-scale three-dimensional motions generated by cell membranes to fit the topography of foreign surfaces and initiate adhesion remain poorly understood. Here, we describe the dynamics of surface deformations displayed by monocytic cells bumping against fibronectin-coated surfaces. We observed membrane undulations with typically 5 nm amplitude and 5-10 second lifetime. Cell membranes behaved as independent units of micrometer size. Cells detected the presence of foreign surfaces at 50 nm separation, resulting in time-dependent amplification of membrane undulations. Molecular contact then ensued with apparent cell-membrane separation of 30-40 nm, and this distance steadily decreased during the following tens of seconds. Contact maturation was associated with in-plane egress of bulky molecules and robust membrane fluctuations. Thus, membrane ...

2008-01-01

243

Hard x-ray phase imaging using simple propagation of a coherent synchrotron radiation beam  

International Nuclear Information System (INIS)

Particularly high coherence of the x-ray beam is associated, on the ID19 beamline at ESRF, with the small angular size of the source as seen from a point of the sample (0.1-1 #mu#rad). This feature makes the imaging of phase objects extremely simple, by using a 'propagation' technique. The physical principle involved is Fresnel diffraction. Phase imaging is being simultaneously developed as a technique and used as a tool to investigate light natural or artificial materials introducing phase variations across the transmitted x-ray beam. They include polymers, wood, crystals, alloys, composites or ceramics, exhibiting inclusions, holes, cracks, ... . 'Tomographic' three-dimensional reconstruction can be performed with a filtered back-projection algorithm either on the images processed as in attenuation tomography, or on the phase maps retrieved from the images with a reconstruction procedure similar to that used for electron microscopy. The combination of diffraction ...

1999-05-21

244

Evolution of surface roughness in silicon X-ray mirrors exposed to a low-energy ion beam  

International Nuclear Information System (INIS)

The possibility of smoothening aspherical X-ray mirrors by irradiation of the surface with a low-energy ion beam is investigated. Nanofocusing being the primary application of these mirrors the ion beam conditions must be optimized to achieve a surface roughness of the order of 0.1-0.2 nm. To address this issue a first study was performed on silicon flat substrates etched using ion energies ranging from 400 to 1200 eV. A second study consisted of eroding the silicon surface while varying the ion grazing incidence angle between 10 deg. and 90 deg. for a fixed value of the ion energy. The surface topography of the samples was characterized at various scales using atomic force microscopy (probed area: 1-10 ?m2), interferential optical microscopy (probed area: 1 mm2) and X-ray scattering (probed area: 100 mm2). Finally, a study by AFM of the evolution of the surface finish level of a silicon mirror after ion erosion at various depth values up to 10 ?m allowed a trade ...

2010-05-01

245

Electromagnetic radiation unmasked  

International Nuclear Information System (INIS)

This article describes the nature of the electromagnetic waves, what they are and how do they affect us. Current concern is focused on exposure to low level power-frequency magnetic fields like microwave radiation from mobile phones and leaking microwave ovens; high power radiation from defence and airport radars; fields close to high voltage transmission lines; radio frequency fields from industrial welders and heaters and DC magnetic fields in aluminium smelters. These fields with frequency less than 300 GHz do not carry sufficient energy to break chemical bonds and it is assumed that they cannot damage cell DNA. The amount of radiation absorbed by a human exposed to far field electromagnetic radiation (EMR) depends on the orientation and size of the person. In the 30-300 MHz range it is possible to excite resonance in the whole or partial body such as the head. It is emphasised that since there are some evidence that electromagnetic fields do harm, a policy of ...

1996-01-01

246

Depth profiling using C{sub 60} {sup +} SIMS-Deposition and topography development during bombardment of silicon  

Energy Technology Data Exchange (ETDEWEB)

A C{sub 60} {sup +} primary ion source has been coupled to an ion microscope secondary ion mass spectrometry (SIMS) instrument to examine sputtering of silicon with an emphasis on possible application of C{sub 60} {sup +} depth profiling for high depth resolution SIMS analysis of silicon semiconductor materials. Unexpectedly, C{sub 60} {sup +} SIMS depth profiling of silicon was found to be complicated by the deposition of an amorphous carbon layer which buries the silicon substrate. Sputtering of the silicon was observed only at the highest accessible beam energies (14.5 keV impact) or by using oxygen backfilling. C{sub 60} {sup +} SIMS depth profiling of As delta-doped test samples at 14.5 keV demonstrated a substantial (factor of 5) degradation in depth resolution compared to Cs{sup +} SIMS depth profiling. This degradation is thought to result from the formation of an unusual platelet-like grain structure on the SIMS crater bottoms. Other unusual topographical features were also ...

2006-07-30

247

Customized computer models of eyes with intraocular lenses  

Science.gov (United States)

We compared experimental wave aberrations in pseudophakic eyes with aspheric intraocular lenses (IOLs) to simulate aberrations from numerical ray tracing on customized computer eye models using corneal topography, angle ?, ocular biometry, IOL geometry, and IOL tilt and decentration measured on the same eyes. We found high correlations between real and simulated aberrations even for the eye with only the cornea, and these increased on average when the IOL geometry and position were included. Relevant individual aberrations were well predicted by the complete eye model. Corneal spherical aberration and horizontal coma were compensated by the IOL, and in 58.3% of the cases IOL tilt and decentration contributed to compensation of horizontal coma. We conclude that customized computer eye models are a good representation of real eyes with IOLs and allow understanding of the relative contribution of optical, geometrical and surgically-related factors to image quality. ...

2007-03-01

248

Cleanup at Los Alamos National Laboratory - the challenges - 9493  

Energy Technology Data Exchange (ETDEWEB)

This paper provides an overview of environmental cleanup at the Los Alamos National Laboratory (LANL) and some of the unique aspects and challenges. Cleanup of the 65-year old Department of Energy Laboratory is being conducted under a RCRA Consent Order with the State of New Mexico. This agreement is one of the most recent cleanup agreements signed in the DOE complex and was based on lessons learned at other DOE sites. A number of attributes create unique challenges for LANL cleanup -- the proximity to the community and pueblos, the site's topography and geology, and the nature of LANL's on-going missions. This overview paper will set the stage for other papers in this session, including papers that present: Plans to retrieve buried waste at Material Disposal Area B, across the street from oen of Los Alamos' commercial districts and the local newspaper; Progress to date and joint plans with WIPP for disposal of the remaining inventory of ...

2008-01-01

249

A comparison of two operational wave assimilation methods  

CERN Document Server

A comparison is carried out between two operational wave forecasting/assimilation models for the North Sea, with the emphasis on the assimilation schemes. One model is the WAM model, in combination with an optimal interpolation method (OIP). The other model, DASWAM, consists of the third generation wave model PHIDIAS in combination with an approximate implementation of the adjoint method. In an experiment over the period February 19 - March 30, 1993, the models are driven by the same wind field (HIRLAM analysis winds), and the same observation data set is assimilated. This set consists of a) spectra from three pitch-and-roll buoys and b) Synthetic Aperture Radar (SAR) spectra from the ERS-1 satellite. Three analysis/forecast runs are performed: one without assimilation, one with assimilation of buoy measurements only, and one with all data assimilated. For validation, observations from four buoys, altimeter data from ERS-1 and Topex-Poseidon, and scatterometer data ...

1997-01-01

250

3-Dimensional Mapping of Corneal Topography and Thickness  

CERN Document Server

Optical sections of the cornea are obtained by illumination with a collimated beam expanded in a fan shape by a small rotary cylindrical lens. The light diffused from the cornea is observed by two cameras and processed in order to yield the surfaces' profiles. The optical system used to project a thin rotating line on the cornea consists of a white light source provided with optical fiber bundle output which is first conditioned by a set of lenses so that it would produce a spot on the cornea. A small cylinder lens is used to expand the beam in one direction so that a thin line illuminates the cornea, rather than a spot. The cylinder lens is provided with motor driven rotation about an axis normal to its own in order to rotate the line on the cornea such that the projected line scans the whole cornea; the illuminator is completed with a slit aperture. The cornea is not perfectly transparent, scattering some of the light that traverses it; this fact is used for its observation by two ...

2003-01-01

251

Analysis of the role of the planetary boundary layer schemes during a severe convective storm  

Energy Technology Data Exchange (ETDEWEB)

The role played by planetary boundary layer (PBL) in the development and evolution of a severe convective storm is studied by means of meso-scale modeling and surface and upper air observations. The severe convective precipitation event that occurred on 14 September 1999 in the northeast of the Iberian Peninsula was simulated by means of the mesoscale model MM5 (version 3) using three different PBL schemes. The numerical results show a large impact of the PBL schemes on the precipitation fields associated to the convective storm. The schemes are based on different physical assumptions: the nonlocal first order medium-range forecast (MRF) and blackadar (BLA) scheme and the local, one-and-a-half order ETA scheme. Surface and radar observations are used to validate the model results. The comparison focuses on three aspects: the evolution, the spatial distribution and the 24-h accumulated precipitation. The comparison with rain gauge observations shows that the MRF, ...

2004-07-01

252

Clinical application of dual energy subtraction in direct digital radiography of chest  

International Nuclear Information System (INIS)

Objective: To discuss the clinical application value of dual energy subtraction (DES) in direct digital radiography of chest. Methods: 83 cases of chest digital radiography(DR) using double-energy subtraction (DES) were randomly selected, and three posterior-anterior (PA) chest films (standard image, bone image and soft tissue image) were obtained in each case, which is so called 'bone and soft tissue separated' technology. Results: With the aid of double energy subtraction (DES), the bony chest was subtracted, the sensitivity and specificity of pulmonary calcification were improved, and sensitivity of pulmonary nodes was also improved, enhancing the distinction between pulmonary benign or malignant lesions, enlightening the diagnosis of chest cage lesions, and showing a clear superiority in the detection of pulmonary nodes comparing to common chest films. The double energy subtraction (DES) films showed a higher diagnostic accuracy in the ...

2009-02-01

253

The application of the Fuji Computed Radiography system for the diagnosis of pneumoconiosis; Determination of optimum conditions of image processing  

Energy Technology Data Exchange (ETDEWEB)

A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned image processings are adopted, FCR can be used for the diagnosis of ...

1993-06-01

254

The application of the Fuji Computed Radiography system for the diagnosis of pneumoconiosis  

International Nuclear Information System (INIS)

A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned image processings are adopted, FCR can be used for the diagnosis of ...

1993-01-01

255

Radiation hardening of CMOS-based circuitry in SMART transmitters  

International Nuclear Information System (INIS)

Process control transmitters that incorporate digital signal processing could be used advantageously in nuclear power plants; however, because such transmitters are too sensitive to radiation, they are not used. The Electric Power Research Institute sponsored work at Sandia National Laboratories under EPRI contract RP2614-58 to determine why SMART transmitters fail when exposed to radiation and to design and demonstrate SMART transmitter circuits that could tolerate radiation. The term ''SMART'' denotes transmitters that contain digital logic. Tests showed that transmitter failure was caused by failure of the complementary metal oxide semiconductors (CMOS)-integrated circuits which are used extensively in commercial transmitters. Radiation-hardened replacements were not available for the radiation-sensitive CMOS circuits. A conceptual design showed that a radiation-tolerant transmitter could be constructed. A prototype for an ...

256

Quantification of "2"3"5U and "2"3"8U activity concentrations for undeclared nuclear materials by a digital gamma-gamma coincidence spectroscopy  

International Nuclear Information System (INIS)

The purpose of this study is to investigate the possibility of verifying depleted uranium (DU), natural uranium (NU), low enriched uranium (LEU) and high enriched uranium (HEU) by a developed digital gamma-gamma coincidence spectroscopy. The spectroscopy consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results demonstrate that the spectroscopy provides an effective method of "2"3"5U and "2"3"8U quantification based on the count rate of their gamma-gamma coincidence counting signatures. The main advantages of this approach over the conventional gamma spectrometry include the facts of low background continuum near coincident signatures of "2"3"5U and "2"3"8U, less interference from other radionuclides by the gamma-gamma coincidence counting, and region-of-interest (ROI) imagine analysis for uranium enrichment determination. Compared to conventional gamma spectrometry, the method ...

2011-06-01

257

Novel Framework for Hidden Data in the Image Page within Executable File Using Computation between Advanced Encryption Standard and Distortion Techniques  

CERN Document Server

The hurried development of multimedia and internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information. In additional, digital document is also easy to copy and distribute, therefore it may face many threats. It became necessary to find an appropriate protection due to the significance, accuracy and sensitivity of the information. Furthermore, there is no formal method to be followed to discover a hidden data. In this paper, a new information hiding framework is presented.The proposed framework aim is implementation of framework computation between advance encryption standard (AES) and distortion technique (DT) which embeds information in image page within executable file (EXE file) to find a secure solution to cover file without change the size of cover file. The framework includes two main functions; first is the hiding of the information in the ...

2009-01-01

258

Interim cryo-cooler/detector report  

Energy Technology Data Exchange (ETDEWEB)

This report describes development of an electronic system designed to reduce vibration generated by a cryocooler. The diminished vibration makes it practical to use the active cooler to extract heat from a portable gamma ray detector instrument. The system was developed for a Sunpower cryocooler with an integrated counterbalance mass. The overall momentum cancellation approach is also applicable to other similar cryocoolers. The cancellation system is an assembly of several components tailored to accomplish the required vibration reduction with minimum power consumption and volume. It is designed to be powered by a 18--32 Volt battery. Up to ten harmonics of the 58.65 Hz drive frequency are controlled. In addition to the vibration cancellation, the electronic system produces the drive signal for the cryocooler and regulates the cooler temperature. The system employs a sinusoidal drive to reduce the amount of higher harmonic vibration. A digital signal processor ...

1995-04-19

259

IGENPRO knowledge-based digital system for process transient diagnostics and management  

Energy Technology Data Exchange (ETDEWEB)

Verification and validation issues have been perceived as important factors in the large scale deployment of knowledge-based digital systems for plant transient diagnostics and management. Research and development (R&D) is being performed on the IGENPRO package to resolve knowledge base issues. The IGENPRO approach is to structure the knowledge bases on generic thermal-hydraulic (T-H) first principles and not use the conventional event-basis structure. This allows for generic comprehensive knowledge, relatively small knowledge bases and above all the possibility of T-H system/plant independence. To demonstrate concept feasibility the knowledge structure has been implemented in the diagnostic module PRODIAG. Promising laboratory testing results have been obtained using data from the full scope Braidwood PWR operator training simulator. This knowledge structure is now being implemented in the transient management module PROMANA to treat unanticipated events and ...

1997-12-31

260

Exploration of exposure dose optimization for pelvic examination in direct digital radiography with a phantom  

International Nuclear Information System (INIS)

Objective: To investigate the relationship between exposure dose and image quality for a direct digital radiography system and to determine the optimum exposure parameters for pelvic examination. Methods: A contrast-detail phantom CDRAD2.0 was exposed to different doses and the IQF of phantom images were calculated. The optimum exposure parameters were determined by ANOVA and SNK analysis. The image of an anthropomorphic phantom taken with optimized exposure parameters was verified using CEC image criteria. Results: The IQF of the images of CDRAD2.0 phantom was significantly different for different doses, as the exposure dose was greater than 0.61 mGy. The IQFs have no difference for different dose groups. The image quality between this optimized exposure dose and conventional exposure dose not was significantly different. Conclusion: The image quality of direct digital radiography system is improved as the exposure dose increases, and as the ...

2005-10-01

261

Comparison of digital and analogue data acquisition systems for nuclear spectroscopy  

International Nuclear Information System (INIS)

In the present investigation the performance of digital data acquisition (DA) and analogue data acquisition (AA) systems are compared in neutron-induced fission experiments. The DA results are practically identical to the AA results in terms of angular-, energy- and mass-resolution, and both compare very well with literature data. However, major advantages were found with the digital techniques. DA allows for a very efficient #alpha#-particle pile-up correction. This is important when considering the accurate measurement of fission-fragment characteristics of highly #alpha#-active actinide isotopes relevant for the safe operation of Generation IV reactors and the successful reduction of long-lived radioactive nuclear waste. In case of a strong #alpha#-emitter, when applying the #alpha#-particle pile-up correction, the peak-to-valley ratio of the energy distribution was significantly improved. In addition, DA offers a very flexible expanded ...

2010-12-21

262

Application of imaging plate technology for NDT; Imaging plate gijutsu to sono oyo  

Energy Technology Data Exchange (ETDEWEB)

This paper describes Fuji computed radiography (FCR) of Fuji Film for NDT (non-destructive testing). Imaging plate (IP) is a two-dimensional detector of X-ray, and shows higher photographic sensitivity than X-ray film. The output emission of IP provides a good linear relationship to X-ray intensity in a wide intensity range. When this emission can be digitized, the X-ray intensity can be also digitized. IP is applied to NDT as an inspection using X-ray. FCR provides higher photographic sensitivity than the conventional X-ray film method, which results in one-fifth to one-twentieth of irradiation time. Images with stable density can be obtained independent of the intensity. Since IP has a wide dynamic range, the variation of X-ray intensity of 1:500 can be expressed in a single image by single shot. High density record including 1000 images can be done using a 5.25 inch optical disk through the digital image processing and ...

1998-10-01

263

A systematic search for novae in M31 on a large set of digitized archival Schmidt plates  

CERN Document Server

This paper reports on the detection of optical novae in our neighbour galaxy M31 based on digitized historical Tautenburg Schmidt plates. The accurate positions of the detected novae lead to a much larger database for searches for recurrent novae in M31. We conducted a systematic search for novae on 306 digitized Tautenburg Schmidt plates covering a time span of 36 years from 1960 to 1996. From the database of both ~ 300 000 light curves and about one million detections on only one plate per colour band, nova candidates were efficiently selected by automated algorithms and subsequently individually inspected by eye. We report the detection of 84 nova candidates. In detail we found 55 nova candidates from the automated analysis of the light curves. Among these, 22 were previously unknown, 12 were known but have not been identified on Tautenburg Schmidt plates before and 21 novae have been discovered on Tautenburg plates previously. An additional ...

2007-01-01

264

The Benchmark Test Results of QNX RTOS  

International Nuclear Information System (INIS)

A Real-Time Operating System(RTOS) is an Operating System(OS) intended for real-time applications. Benchmarking is a point of reference by which something can be measured. The QNX is a Real Time Operating System(RTOS) developed by QSSL(QNX Software Systems Ltd.) in Canada. The ELMSYS is the brand name of commercially available Personal Computer(PC) for applications such as Cabinet Operator Module(COM) of Digital Plant Protection System(DPPS) and COM of Digital Engineered Safety Features Actuation System(DESFAS). The ELMSYS PC Hardware is being qualified by KTL(Korea Testing Lab.) for use as a Cabinet Operator Module(COM). The QNX RTOS is being dedicated by Korea Atomic Energy Research Institute (KAERI). This paper describes the outline and benchmarking test results on Context Switching, Message Passing, Synchronization and Deadline Violation of QNX RTOS under the ELMSYS PC platform

2010-10-01

265

Somatic and genetic radiation exposure of the patient in digital subtraction angiography (DSA)  

International Nuclear Information System (INIS)

The somatic and genetic radiation exposure of patients undergoing Digital Subtraction Angiography (DSA) and traditional Film Arteriography (FA) of cranial, cervical, thoracic and abdominal vascular territories are compared. The radiation doses absorbed within the critical organs - red bone marrow, lung, thyroid gland and female breast - and in the gonads were measured using an anthropomorphic Alderson phantom. A Somatic Dose Index was calculated in order to estimate the somatic radiation risk. The somatic radiation exposure depends upon the location of the critical organs with respect to the entrance site of the x-ray beam, and can be reduced by an appropriate choice of the angiographic projection. Under this condition, the radiation exposure of the patient during DSA can be lower than during FA. For renal DSA an a.p. projection, the use of an abdominal compression device and careful caudal shielding of the field are advocated. (orig.).

1986-01-01

266

Revisited the mathematical derivation wall thickness measurement of pipe for radiography  

Energy Technology Data Exchange (ETDEWEB)

Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and geometrical ...

2007-07-01

267

REVIEW: Optical waveguide processors  

Science.gov (United States)

An analysis is made of the basic principles and methods of construction of integrated optical circuits (IOC) for data processing, which are optical waveguide processors in the integrated form. A classification is provided of IOC in accordance with the nature of the input connections to optical components and in accordance with their intended function. An analysis is made of the current status of research and development of analog IOC for handling analog and digital signals, IOC for computing technology, and switching IOC. A detailed analysis is made of IOC with different functions in data processing: spectrum analyzers and correlators, analog-digital converters, circuits for identification of data sets and for encoding of signals, threshold and multistable circuits, logic and arithmetic units, and switching arrays. Descriptions are given of IOC for optically controlled data handling: bistable purely optical logic circuits, multivibrators, ...

1987-07-01

268

Normalized noise power spectrum of full field digital mammography detector system  

International Nuclear Information System (INIS)

Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)

269

Normalized Noise Power Spectrum of Full Field Digital Mammography System  

International Nuclear Information System (INIS)

A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality.

2010-01-05

270

Modular Traffic Sign Recognition applied to on-vehicle real-time visual detection of American and European speed limit signs  

CERN Document Server

We present a new modular traffic signs recognition system, successfully applied to both American and European speed limit signs. Our sign detection step is based only on shape-detection (rectangles or circles). This enables it to work on grayscale images, contrary to most European competitors, which eases robustness to illumination conditions (notably night operation). Speed sign candidates are classified (or rejected) by segmenting potential digits inside them (which is rather original and has several advantages), and then applying a neural digit recognition. The global detection rate is ~90% for both (standard) U.S. and E.U. speed signs, with a misclassification rate 150 minutes of video. The system processes in real-time ~20 frames/s on a standard high-end laptop.

2009-01-01

271

Measurement of dynamic fracture toughness and failure behavior for explosive mock materials  

British Library Electronic Table of Contents (United Kingdom)

In this work, a pre-cracked semi-circular shaped explosive simulant was loaded using a split Hopkinson pressure bar (SHPB). A high-speed camera was used to capture the deformation and fracture process of the specimen in situ. The digital images were processed using the digital image correlation (DIC) method. Next, full displacement and strain fields were obtained. The displacement vector field shows that the specimen fractured under tensile stress action. The strain field can be used to predict the crack propagation. Results show that the method of combined DIC and SHPB is effective to study the dynamic deformation and fracture behavior of explosive simulants. In addition, the specimen was loaded using a drop weight. The fracture toughness of the specimen was preliminary measured.

2011-01-01

272

Instruments for X-ray fluorescence analysis and spectrometry  

International Nuclear Information System (INIS)

The radionuclide X-ray fluorescence analyzer consists of a source changer and a sample changer. "5"5Fe, "1"0"9Cd and "2"4"1Am are used as excitation sources. The radiation is detected with a semiconductor Si(Li) detector. The complete assembly of the apparatus consists of an imagine unit, a keyboard, a floppy disc drive, a printer, a console and a rack with analog and digital electronics. Its multichannel amplitude analyzer consists of power supplies, a high voltage supply, a linear amplifier, an analog-to-digital converter and a computer. The technical specifications are given. The control and data processing system is controlled with an MHB 8080A microprocessor. Software for semiconductor gamma spectrometry and for quantitative gamma spectrometry will be supplied with the equipment. (E.S.). 3 figs., 4 refs.

273

Implantation of an electronic system for real time neutron graphic images acquisition at the IPEN/CNEN Argonaut reactor; Implantacao de um sistema eletronico para aquisicao de imagens neutrongraficas em tempo real no reator Argonauta do IEN/CNEN  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is the implantation and characterization of a neutron radiography system that uses an electronic device for attainment of images in real time, for its implementation in the nuclear research reactor Argonauta at IEN/CNEN (Nuclear Engineering Institute of the Brazilian Nuclear Energy Commission). The Electronic Imaging System in Real Time is composed by a scintillator screen for neutron, a video camera (CCD), a digital plate and a computer with specific computational programs for digital processing of the images. The System in installed real time is apt to carry through neutron radiography inspections of static and dynamic events of several types of samples. (author)

2004-04-15

274

Fundamental aspects of fault location algorithms used in distance protection  

Energy Technology Data Exchange (ETDEWEB)

Considers fundamental problems involved in the precise location of faults on high-voltage transmission lines. The influence of pre-fault load on the distance-to-fault measurement problem is analysed and a new method of accounting for load effects is presented. Two of the algorithms considered are precise, containing no simplifyng assumptions and their overall accuracy is limited only by the accuracy of digital impedance relays at both ends of the protected circuit. A third algorithm presents a new approach to the fault location problem, which requires digital impedance relays at one end only of a transmission line. The procedures described are applicable to any system arrangement and are suitable for a wide range of fault resistance values.

1986-09-01

275

Estimating hip fracture risk from digital x-ray image data  

International Nuclear Information System (INIS)

The authors propose a method for determining the risk of femoral neck fracture in osteoporotic patients that is not based on densitometric techniques. The method is based on a structural analysis performed by a computer on data taken from a single digital anteroposterior projection of the hip. From the image, the effective cross-sectional area and cross-sectional moment of inertia are computed from attenuation principles. Together with other geometric measurements, these data are used in an engineering analysis to compute the yield strength of the proximal femur, under stress applied through the acetabulum in a one-legged stance. An index of fracture risk based on the ratio of estimated yield strength to body weight is proposed. Ultimately it is expected that this work will allow the clinician to estimate hip fracture risk in osteoporotic patient using widely available existing technology, a goal which has eluded bone density-based methods.

276

Document image retrieval with morphology-based segmentation and features combination  

Science.gov (United States)

Digital libraries need more than just a retrieval based on keywords, which can be inefficient for some applications. Thus, a document retrieval based on content of the digitized image version of the document can be a more appropriated approach. This paper discusses the retrieval of document images by means of identifying a variety of elements present in the document's image body. We propose a new strategy to identify and combine features extracted from a document image. We also consider the task of constructing an optimized feature set to improve the retrieval performance and to validate our experiments on an assorted database. Experimental results show that the proposed segmentation together with a wisely feature combination increase the overall retrieval performance. Moreover the retrieved images demonstrate the generality and effectiveness of our approach for an efficient segmentation and classification of document images.

2011-01-01

277

Digital Libraries: From Process Modelling to Grid-based Service Oriented Architecture  

CERN Document Server

Graphical Business Process Modelling Languages (BPML) like Role Activity Diagrams (RAD) provide ease and flexibility for modelling business behaviour. However, these languages show limited applicability in terms of enactment over distributed systems paradigms like Service Oriented Architecture (SOA) based grid computing. This paper investigates RAD modelling of a Scientific Publishing Process (SPP) for Digital Libraries (DL) and tries to determine the suitability of Pi-Calculus based formal approaches to enact SOA based grid computing. In order to achieve this purpose, the Pi-Calculus based formal transformation from a RAD model of SPP for DL draws attention towards a number of challenging issues including issues that require particular design considerations for appropriate enactment in a SOA based grid system.

2006-01-01

278

Correlation between the Individual and the Combined Width of the Six Maxillary Anterior Teeth  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Purpose: There is a consensus in the community of dental research that the selection of undersized artificial maxillary anterior teeth offers an unnatural appearance to the denture. Several methods to select the adequate width of these teeth are of questionable validity, and many dentures have an obviously artificial appearance. This article assessed the relationship between the individual and the combined width of maxillary anterior teeth. Materials and Methods: Impressions were made of the anterior dentition of 69 dentate undergraduate students with rubber impression silicon, and casts were formed. The individual widths of the maxillary anterior teeth were measured by using a digital caliper (SC-6 digital caliper, Mitutoyo Corporation, Tokyo, Japan), and the combined width was r...

2009-01-01

279

Compare analysis of efficiency of using of digital and analog regimes of registration of radiation in radiometric systems of radiation thickness measuring  

International Nuclear Information System (INIS)

A consideration is given to the problem of selecting optimized methods of radionuclide radiation registration during the control of the objects with essential changes in thickness. Adequate model of information signal formation is developed and analyzed for the case of the existence of an inertial link of the system with the dead time of a noncontinued type. The boundary values of radiation thickness and radiation flux intensity that divide the priority of using either digital or analog registration modes are revealed. The method is found for the full correction of a systematic error of flux intensity measurement because of the dead time of the apparatus. To control the objects with essential variation of thickness the method of selective measurement of radiation intensity is proposed

280

Class 1E digital systems studies  

International Nuclear Information System (INIS)

This document is furnished as part of the effort to develop NRC Class 1E Digital Computer Systems Guidelines which is Task 8 of USAF Rome Laboratories Contract F30602-89-D-0100. The report addresses four major topics, namely, computer programming languages, software design and development, software testing and fault tolerance and fault avoidance. The topics are intended as stepping stones leading to a Draft Regulatory Guide document. As part of this task a small scale survey of software fault avoidance and fault tolerance practices was conducted among vendors of nuclear safety related systems and among agencies that develop software for other applications demanding very high reliability. The findings of the present report are in part based on the survey and in part on review of software literature relating to nuclear and other critical installations, as well as on the authors' experience in these areas.

281

Application of digital radiography to diagnosis of laryngeal diseases  

International Nuclear Information System (INIS)

Fuji Computed Radiography (FCR) is a new system of digital radiography that is based on the latest computer technologies. We applied this FCR system to the X-ray diagnosis of the laryngeal disease. Twenty patients with various laryngeal diseases were evaluated by both FCR frontal tomography and conventional screen-film frontal tomography under the same exposure condition. Both tomograms were then compared on the subject of the clarity of delineation of laryngeal structures. As the result, FCR tomograms revealed the feature of the laryngeal lumen and cartilages more clearly than conventional tomograms. In addition, energy subtraction method, which is one of FCR image processing systems, was presented as a new technical procedure to extinguish cervical spine shadows in plain anteroposterior laryngeal X-photograph. We stress that FCR system is the suitable procedure for X-ray analysis of laryngeal diseases, especially in the region related with the phono-surgery. ...

1986-01-01

282

An integrating dosimeter for pulsed radiation  

Science.gov (United States)

A Pulsed Radiation Dosimetry System designed to measure radiation produced by particle accelerators is described. The problems associated with total-dose measurement of irregular shaped pulses of ionizing radiation have been simplified. The system responds to extremely narrow pulses of charged particles or X-rays using a pin diode as the detector. Direct readout of dose in rads (Si) is displayed on a 3-1/2 digit digital panel meter. The system will operate in either the multiple-pulse or single-pulse mode. The multiple-pulse mode would be useful in monitoring or tuning a linear accelerator. In the single-pulse mode the system will automatically display total dose of a transient event in real time and hold that measurement indefinitely or until the next measurement is made. The system features an automatic reset in either mode.

1983-12-01

283

A study on the comparative method using AHP and GIS based distributed runoff model  

British Library Electronic Table of Contents (United Kingdom)

Research in the field of river hydrology has been mainly concerned with the investigation of the rainfall-runoff phenomenon through the analysis of hydrological factors such as meteorology and geography, with the focus being on each river basin. Recently, various forms of digital information such as GIS (Geographic Information System) and RS (Remote Sensing) data have been made available in worldwide digital map format. Therefore, there has been a shift in focus from lumped-parameter models to distributed runoff models, as the latter can consider temporal and spatial variations in water quantity. Distributed runoff models have made possible the comparison of runoff field and rainfall-runoff characteristics considering spatial distribution. Hydrological conditions are differently distribute...

2010-01-01

284

iWork '09 The Missing Manual  

CERN Document Server

With iWork '09: The Missing Manual, you'll quickly learn everything you need to know about Apple's incredible productivity programs, including the Pages word-processor, the Numbers spreadsheet, and the Keynote presentation program that Al Gore and Steve Jobs made famous. This book gives you crystal-clear and jargon-free explanations of iWork's capabilities, advantages, and limitations to help you produce stunning documents and cinema-quality digital presentations in no time.

2009-01-01

285

Three-Dimensional Dispaly Of Document Set  

Energy Technology Data Exchange (ETDEWEB)

A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

2003-06-24

286

Study for the Optimal Operation of D(sub 2)O Vapour Recovery System.  

Science.gov (United States)

Digital control technology using micro-processor is widely used in Factory Automation area since 1980's. However, the D(sub 2)O Vapour Recovery System in Wolsung 1 N.P.P is controlled by mechanical timer without considering the moisture condition in the R...

1997-01-01

287

Solar Eclipse Images - SDAC Home Page - NASA  

Science.gov (United States)

Oct 24, 1995 ... The photos were made with a Nikon FE and a Sigma 400mm APO f/5.6 lens ... Note: The JPEG images to which the above links point contain subtle ... India on 1995 October 24 with a digital camera and Fe X 6374 ? filter, ...

288

Scalable digital libraries of event data and the NSCP meta-cluster  

Energy Technology Data Exchange (ETDEWEB)

In this paper we present the design, implementation, and experimental results of a system to mine and visualize event data using cluster computingbuilt upon an ATM network. Our approach is to build a system using light weight, modular software tools for data management, resource management, data analysis and visualization developed for local, campus and wide area clusters of workstations. (author)

1996-07-01

289

Residential accessibility to information technology retailers and self reported computer use among patients attending community clinics  

UK PubMed Central (United Kingdom)

The actual mechanisms that maintain the individual disparities in home computer use and internet access that are collectively termed “the digital divide” remain unclear. We hypothesized...Full Text Available

2009-01-01

290

Optimal Knot Selection for Least-squares Fitting of Noisy Data with Spline Functions  

Energy Technology Data Exchange (ETDEWEB)

An automatic data-smoothing algorithm for data from digital oscilloscopes is described. The algorithm adjusts the bandwidth of the filtering as a function of time to provide minimum mean squared error at each time. It produces an estimate of the root-mean-square error as a function of time and does so without any statistical assumptions about the unknown signal. The algorithm is based on least-squares fitting to the data of cubic spline functions.

2008-05-15

291

Microsoft Word - postpn270.doc  

Wastenet

protect digital information, from personal details held on a computer to financial details transmitted over the Internet. Encryption ...in connection with electronic data (Box 2), whether stored on a computer or transmitted over an unsecured network such as ...Encryption tools (usually in the form of computer programs or software) are widely available

292

Measurements of nuclear emulsion tracks by means of a picture analysis system  

Energy Technology Data Exchange (ETDEWEB)

A semiautomatic system for measurements of nuclear tracks in nuclear emulsion is described. The microscopic image of a particle track is picked up by a video camera. The video picture is digitized in real time. The picture analysis is done via software. The microscope is equipped with a stepping motor driven stage which is also computer-controlled.

1986-01-01

293

Lagrangian analysis of contaminant dispersal in bounded turbulent shear flows  

Energy Technology Data Exchange (ETDEWEB)

Methods of solving Navier-Stokes equations for turbulent channel flow are given. These numerical solutions utilize either Neumann or Dirichlet boundary conditions. Computer codes were written and tested and are discussed. Digital image processing of flow visualization video sequences, taken simultaneously with vorticity probe measurements in a turbulent boundary layer, were carried out. 4 figs. (GHH)

1991-01-01

294

Implementation and laboratory test results for a fuzzy logic based self-tuned power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the implementations of a fuzzy logic based self-tuned controller to improve the stability of electric power systems. The stabilizing signal is computed using the standard fuzzy membership function depending on the speed/acceleration state of the generator in the phase plane. The performance of the proposed stabilizer is demonstrated by practical implementation using a digital signal processor mounted on a PC-AT. Results of the experimental tests on a physical model of a power system are presented.

1993-06-01

295

Image-enhancement applications at the Lawrence Livermore National Laboratory  

Energy Technology Data Exchange (ETDEWEB)

A diverse set of digital image-processing applications exists at the Lawrence Livermore National Laboratory. While many of these include some sort of image analysis or restoration, virtually all of them require image-enhancement procedures. In this paper we describe the principal image-processing facility at the Laboratory, followed by a discussion of several of the major image-processing application areas.

1982-06-01

296

High resolution seismic refraction method with multichannel digital data acquisition system; Digital ta channel sokutei system wo mochiita koseido kussetsuho jishin tansa  

Energy Technology Data Exchange (ETDEWEB)

This paper introduces a multichannel digital data acquisition system and examples of measurements with the system in seismic exploration using the high resolution seismic refraction method. The high resolution seismic refraction system performs analyses nearly automatically by using a computer after initial travel time has been read. Therefore, the system requires high-accuracy travel time data, for which a multichannel digital measuring instrument developed recently for seismic exploration using the refraction method has been used for the measurement. The specification specifies the number of channels at 144 as a maximum, a sampling time of 62.5 {mu}sec to 4 m sec, the maximum number of sampling of 80,000 samples, and gain accuracy of {plus_minus} 1%. The system was used for surveying a tunnel having a maximum soil cover of about 800 m. The traverse line length is about 6 km, the distance between vibration receiving points is 50 m, and the ...

1997-05-27

297

From tomography to voludensitometry: radiation detectors for industrial control and medical instrumentation; De la tomographie a la voludensitometrie: les capteurs pour le controle industriel et l`instrumentation medicale  

Energy Technology Data Exchange (ETDEWEB)

In this article, the author presents the main technological solutions, available or in development, on X-ray detectors in order to obtain a digital image in biomedical radiography or in industrial radiography: linear x-ray detectors and bidimensional x-ray detectors (memory radioluminescent screens, matrix plan detectors).

1993-12-01

298

Evaluation of the 1Shot Phantom dedicated to the mammography system using FCR  

International Nuclear Information System (INIS)

Currently daily quality control (QC) tests for mammography systems are generally evaluated by using visual analysis phantoms, which of course means subjective measurement. In our study, however, we evaluated a novel digital phantom, the 1Shot Phantom M plus (1Shot Phantom), together with automatic analysis software dedicated for mammography systems using Fuji computed radiography (FCR). The digital phantom enables objective evaluation by providing for actual physical measurement rather than subjective visual assessment. We measured contrast to noise ratio (CNR), image receptor homogeneity, missed tissue at chest wall side, modulation transfer function (MTF), and geometric distortion utilizing the 1Shot Phantom. We then compared the values obtained using the 1Shot Phantom with values obtained from the European guidelines and International Electrotechnical Commission (IEC) standards. In addition, we evaluated the convenience of using the ...

2009-07-01

299

Estimation of errors provided with dead times of roentgen digital tomography  

International Nuclear Information System (INIS)

Impact of apparatus dead time on the accuracy of measurement of radial distribution of the radiation attenuation factor in the roentgen computer tomography for rotation bodies is studied. Analytical expressions are obtained. Calculations of the threshold loads for radiometric detectors, providing for the accuracy of measurement at the stage of designing the tomographic complex detecting unit, are obtained

300

Electrical Circuit Tester  

Energy Technology Data Exchange (ETDEWEB)

An electrical circuit testing device is provided, comprising a case, a digital voltage level testing circuit with a display means, a switch to initiate measurement using the device, a non-shorting switching means for selecting pre-determined electrical wiring configurations to be tested in an outlet, a terminal block, a five-pole electrical plug mounted on the case surface and a set of adapters that can be used for various multiple-pronged electrical outlet configurations for voltages from 100 600 VAC from 50 100 Hz.

2006-04-18

301

Digital subtraction angiography with scanning lazer stimulated luminescence  

International Nuclear Information System (INIS)

Fuji Computed Radiography (FCR) utilizes imaging plates of scanning lazer stimulated luminescence. FCR can be used for intravenous digital subtraction angiography (IVDSA) and for intraarterial studies because of tis high contrast and spatial resolution. Pixel size of the imaging plates for angiography is 0.2 mm. Experimentally, it could demonstrate a vessel 1 mm in diameter with a contrast of 0.1, when opacified with a contrast medium of 3 % iodine concentration, and could image a vessel 3 mm in diameter with contrast of 0.1, when opacified with 1 % contrast medium. A 20 % stenosed portion of a vessel 3 mm in diameter was identified when opacified with 3 % contrast medium, and a 20 % stenosed portion of a vessel 2 mm in diameter was identified when opacified with 10 % contrast medium. In 105 IVDSA examinations of 75 patients, FCR was superior to Digital Fluorography (DF) in spatial resolution, size of examination field, dynamic range and ...

1985-01-01

302

Digital atlas of fetal brain MRI  

International Nuclear Information System (INIS)

Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C, permits linked ...

2010-02-01

303

Development of Hardware for Power System Stabilizer (PSS)  

Energy Technology Data Exchange (ETDEWEB)

The basic function of a Power System Stabilizer (PSS) is to add damping to the generator rotor oscillations by controlling its excitation using auxiliary stabilizing signals. To provide damping, the stabilizer must produce a component of electrical torque in phase with the rotor speed deviations. This paper introduces the hardware specifications and various functions of microprocessor (TMS320C32)-based digital PSS to provide the damping torque. (author). 3 refs., 6 figs.

2001-07-01

304

Creating Open Digital Library Using XML Implementation of OAi-PMH Protocol at CERN  

CERN Document Server

This article describes the implementation of the OAi-PMH protocol within the CERN Document Server (CDS). In terms of the protocol, CERN acts both as a data provider and service provider and the two core applications are described. The application of XML Schema and XSLT technology is emphasized.

2002-01-01

305

Convergenomics Strategic Innovation in the Convergence Era  

CERN Document Server

Convergenomics is about the megatrends that are shaping how people behave and organizations work. In this insightful analysis, Sang Lee and David Olson describe how globalization, digitization, changing demographics, changing industry mix, deregulation and privatization, commoditization of processes, new value chains, emerging new economies, deteriorating environment, and cultural conflicts have led to what they define as a convergence revolution.Lee and Olson discuss this convergence revolution from the perspectives of technology, industry, knowledge, open-source networking and bio-artificial

2010-01-01

306

Canon's flat-panel detector  

International Nuclear Information System (INIS)

We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curve, modulation transfer function (MTF), Wiener spectrum (WS), noise equivalent quanta (NEQ)) for Cannon's flat-panel detector (FPD), Fuji computed radiography (FCR) and screen-film (S/F) systems, respectively. First, the digital and overall characteristic curves of FPD and FCR systems were more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of FPD system were better than those of FCR system a little at lower spatial frequencies than 0.8 mm"-"1, but the overall MTF of FPD and FCR systems were worse than that of S/F system a little at all spatial frequencies. Third, the digital and overall WS of FPD system were similar or better than those of FCR system, but the overall WS of FPD and FCR systems were worse than that of S/F system. Fourth, the pre-sampling and overall NEQ of FPD system ...

2002-12-01

307

Canon's flat-panel detector  

Energy Technology Data Exchange (ETDEWEB)

We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curve, modulation transfer function (MTF), Wiener spectrum (WS), noise equivalent quanta (NEQ)) for Cannon's flat-panel detector (FPD), Fuji computed radiography (FCR) and screen-film (S/F) systems, respectively. First, the digital and overall characteristic curves of FPD and FCR systems were more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of FPD system were better than those of FCR system a little at lower spatial frequencies than 0.8 mm{sup -1}, but the overall MTF of FPD and FCR systems were worse than that of S/F system a little at all spatial frequencies. Third, the digital and overall WS of FPD system were similar or better than those of FCR system, but the overall WS of FPD and FCR systems were worse than that of S/F system. Fourth, the pre-sampling and overall NEQ of ...

2002-12-01

308

Automatic interpretation of MSS-LANDSAT data applied to coal refuse site studies in southern Santa Catarina State, Brazil  

Energy Technology Data Exchange (ETDEWEB)

The coal mining district in southeastern Santa Catarina State is considered one of the most polluted areas of Brazil. The author has identified significant preliminary results on the application of MSS-LANDSAT digital data to monitor the coal refuse areas and its environmental consequences in this region.

1982-05-01

309

Application of neural networks to pulse-shape analysis of Bragg curves  

Energy Technology Data Exchange (ETDEWEB)

A novel approach is presented to extract relevant parameters associated with the energy loss of ejectiles from nuclear reactions obtained by digitizing the signals of a Bragg curve spectrometer. New and more powerful computational paradigms allow a more thorough pulse-shape analysis. This is fulfilled using a back-propagation artificial neural network as a pattern identifier. The known problem of over-training is discussed.

2006-01-15

310

Advantages of magnification in digital phase-contrast mammography using a practical X-ray tube  

Energy Technology Data Exchange (ETDEWEB)

Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point source results in a phase contrast too narrow for detection with CR. In addition to phase contrast improving image quality, a re-scaling effect increases image sharpness in ...

2008-12-15

311

Accessibility and Metadata in Digital Libraries  

Science.gov (United States)

Metadata can be used to support accessibility in connection with improved discovery. ...certain metadata elements provide information about what capabilities are needed--either perceptual-motor, cognitive, socio-economic or geographic--to make use of a resource. This cam improve the ability of users who are disadvantaged in these ways to find resources that meet their needs--and avoid ones [resources] that do not.

2003-03-18

312

Detection of pollution-induced forest decline in the Kola Peninsula using remote sensing and mathematical modelling  

Energy Technology Data Exchange (ETDEWEB)

Forests on the Kola Peninsula in Northern Russia grow close to the northern tree line. They are subjected to both natural and anthropogenic stress factors. The Cu-Ni smelter 'Severonikel' (Lat. 67 deg 55'N; Long. 32 deg 57'E) near Monchegorsk is one of the two major sources of sulphur dioxide and heavy metals emissions on the Kola Peninsula. These emissions have caused significant deterioration of the surrounding vegetation. The thesis demonstrates how methods of Remote sensing, ground survey and mathematical modelling can be integrated for monitoring of the smelter's environmental impact on the surrounding vegetation: ground truth data are used for calibration of remote-sensed data, which further serve to verify mathematical models. The study aims were: * to estimate the scale of airborne sulphur pollution from the smelting industry on the Kola Peninsula and its effect on vegetation; * to assess spatial extent of the forest decline in the ...

1998-07-01

313

Wisconsinan-Holocene seismic stratigraphy of the Keathley Canyon Area and vicinity, northwestern Gulf of Mexico  

Science.gov (United States)

The lower continental slope of the northwestern Gulf of Mexico is characterized by a hummocky topography with shallow salt masses interspersed by numerous salt-withdrawal basins containing thick Plio-Pleistocene and older sediments. Analysis of over 7500 km of multichannel seismic reflection data from the Keathley Canyon Area and vicinity defined the Wisconsinan-Holocene sequence and its seismic facies. In interbasinal areas and in the southern part of the study area where salt is shallow, the Wisconsinan-Holocene sequence consists mainly of low-amplitude (LA) facies underlain by strong basal-reflection (SBR) facies. The LA facies occasionally show subtle onlaps against SBR facies and grade upward into a draping pattern. Onlapping LA facies are interpreted to be a lowstand systems tract deposited by widespread low-energy turbidity currents. Draping LA facies at the top may consist of hemipelagic or pelagic sediments. The SBR facies are interpreted to consist of ...

1991-03-01

314

Validation of the Canadian atmospheric dispersion model for small exclusion area boundaries  

International Nuclear Information System (INIS)

AECL is undertaking the validation of ADDAM, an atmospheric dispersion and dose code based on the Canadian Standards Association model CSA N288.2. The key component of the validation program involves the comparison of air concentrations predicted by the model with measured values. Measurements are available from field studies at two Canadian reactor sites and from a wind tunnel study of the CANDU site at Wol song, Korea. The measurements were obtained close enough to the release points to test the model for exclusion area boundaries as small as 500 m. Model predictions were higher than the observations almost 75 percent of the time and the magnitude of the over predictions was typically much larger than the magnitude of the under predictions. The effect of the topography at the Wol song site was limited to small changes in plume trajectory due to channeling in valleys and a small reduction in the lateral spread of the plume. The terrain did not substantially ...

1999-11-04

315

The effect of local circulations on the variation of atmospheric pollutants in the northwestern Taiwan  

Energy Technology Data Exchange (ETDEWEB)

A field experiment was held in the northwestern Taiwan as a part of a long-term research program for studying Taiwan`s local circulation. The program has been named as Taiwan Regional-circulation Experiment (TREX). The particular goal of this research is to investigate characteristics of boundary layer and local Circulation and their impact on the distribution and Variation of pollutants in the northwestern Taiwan during Mei-Yu season. It has been known for quite sometime that land-sea breeze is very pronounced under hot and humid conditions. Extensive network includes 11 pilot ballon stations, 3 acoustic sounding sites, and 14 surface stations in about 20 km by 20 km area centered at National Central University, Chung-Li. In addition, there are ground temperature measurements at 3 sites, Integrated Sounding System (ISS) at NCU, air plane observation, tracer experiment with 10 collecting stations, 3 background upper-air sounding stations, 2 towers etc. NOAA and GMS satellite data, sea ...

1996-12-31

316

Statistical description and estimation of ocean drift ice environments  

Energy Technology Data Exchange (ETDEWEB)

Part I of this thesis is on long-term iceberg collision-risk assessment methods for fixed offshore structures. Estimates for the long-term probability that an iceberg will hit a fixed offshore structure are based on estimates of the total volume of produced iceberg, a model for the size distribution of icebergs and a description of how iceberg trajectories ``fill`` the plane (the ocean`s surface). Part II of the thesis discusses methods for analysis of low resolution data in the sense that the size of the area covered by each pixel is not small compared to the dominating floes. Still, this type of data can provide estimates of the ice extent (and hence the ice edge) and ice concentration. The estimates of the ice edge (at least) seem to be physically significant in the sense that ``in some way`` they can reflect ice drift in an image time sequence. A priori this is far from obvious. A central idea is that the ``ice edge`` is close to a transition zone between two different temperature ...

1991-04-01

317

Smart meter status report from Toronto  

Energy Technology Data Exchange (ETDEWEB)

An update of Toronto Hydro's smart metering program was presented. Electricity demand is expected to keep increasing, and there is presently insufficient generation to match supply needs in Ontario. The smart metering program was introduced to aid in the Ontario government's energy conservation strategy, as well as to address peak supply problems that have led to power outages. It is expected that the smart metering program will reduce provincial peak supply by 5 per cent, as the meters support both time-of-use rates and critical peak pricing. Over 800,000 smart meters will be supplied to customers by 2007, and all 4.3 million homes in Toronto will have a smart meter by 2010. In order to meet targets for 2010, the utility will continue to install more 15,000 meters each month for the next 4 years. While the Ontario government has planned and coordinated the rollout and developed smart metering specifications and standards, Toronto Hydro is responsible for the ...

2006-07-01

318

Sequence stratigraphic analysis of stratigraphic oil traps in the west Siberian Neocomian  

Energy Technology Data Exchange (ETDEWEB)

Large depositional oil traps (Priob, Sugmut, etc.) have been discovered in the West Siberian Neocomian. Sequence stratigraphic analysis of well logs and seismic reflection profiles demonstrate that reservoirs of these fields represent sands deposited during lowstand, transgressive and highstand phases of relative sea level cycles. Transgressions and regressions advanced in regional longitudinal and local latitudinal directions. The regional longitudinal pattern is dominated by westward prograding clinoforms formed as the sediment supply exceeded the accommodation space. Local northward and northwestward prograding complexes appear to be controlled by local basin-floor topography. In each systems tract, the coastal zones were landward from the shelf-breaks resulting in dominance of marine facies at each depositional shelf-edge. Lowstand systems tracts are represented on the upper slope by prograding wedges with thin shelfal equivalents or correlative unconformities. ...

1996-12-31

319

Reference scenarios for deforestation and forest degradation in support of REDD: a review of data and methods  

Energy Technology Data Exchange (ETDEWEB)

Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including FAO (Food and Agricultural Organization of the United Nations) national statistics and various remote sensing sources. The ...

2008-04-15

320

Reference scenarios for deforestation and forest degradation in support of REDD: a review of data and methods  

International Nuclear Information System (INIS)

Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including FAO (Food and Agricultural Organization of the United Nations) national statistics and various remote sensing sources. The freely ...

321

Radon measurements in soil - tests in Krakow agglomeration  

International Nuclear Information System (INIS)

The migration of gaseous radon through the soil is depending on the geology of the region and may vary locally because of occurrence of fractures in impermeable layers and existence of fractures and faults. To identify areas with elevated radon concentration in soil gas, it is very helpful to know the geological structure of the area under study and how the high permeability soils are situated in the overburden. Topography of the surface in the Krakow area is determined by exhumed structure of late Alpine foreland, dismembered into systems of several normal fault-bounded carbonate horsts, erosional monadocks and grabens, and partially filled with marine Miocene clays of Carpathian foredeep basin. Radon geofluid, generated partially in sub-Jurassic, U-rich crystalline basement, migrates vertically to surface through permeable, jointed, faulted and karstified Jurassic limestone. Under the cover the radon fluxes are channelled by adjacent list ric faults and ...

2000-10-14

322

On the influence of microstructure and carbide content of steels on the electrochemical dissolution process in aqueous NaCl-electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical dissolution behaviour of armco-iron and of the steels C15, C45, C60 and 100Cr6 in concentrated sodium chloride media has been investigated. Anodic metal dissolution experiments have been carried out using the flow channel cell (parallel plate reactor), the rotating cylinder electrode (RCE) and the capillary cell. The microstructure of the steel has been varied through variation of carbon content and heat treatment (e.g. soft annealed with globular carbides or pearlitic). Current-efficiency values have been obtained by gravimetric measurements in the current-density range from i=5 to 60 A/cm{sup 2}. For the soft annealed steels, the divalent ferrite dissolution in combination with electroless cementite removal dominates. For the pearlitic steels, the occurrence of oxygen evolution electronically conductive metal carbides or trivalent ferrite dissolution, depending on the current density applied, was detected. Microstructure dependent potentiostatic current transients ...

2002-10-01

323

Net ecosystem CO{sub 2} exchange of a cutover peatland rehabilitated with a transplanted acrotelm  

Energy Technology Data Exchange (ETDEWEB)

Peatlands are an important long-term sink for atmospheric carbon dioxide (CO{sub 2}). The storage function of peatland ecosystems is significantly impacted by drainage and extraction processes, which can result in the release of significant amounts of CO{sub 2}. This paper investigated the net ecosystem CO{sub 2} exchange of a newly developed extraction-restoration technique that preserved the acrotelm and replaced it directly on the cut surface of the peatlands. The technique used a modified block-cut method with a back-hoe to create a drainage ditch. Actrotelm and surface vegetation were removed and placed to one side, and the peat was mechanically removed. The acrotelm was then transplanted over the older and more decomposed catotelm peat to create a trench topography in which the natural peatland was higher than the extracted zone. Air temperatures, water table levels, and volumetric moisture content levels were measured throughout the experiment. Measurements ...

2008-07-01

324

Microscopic properties of passive films on Ti and Zr from optical, electrochemical and SXM-measurements  

International Nuclear Information System (INIS)

A combined application of several microtechniques is presented and discussed with the Ti/TiO_2 and Zr/ZrO_2-systems as an example. All measurements were carried out on single grains of technical materials in order to detect and quantify the effect of substrate microstructure on the properties of anodic passive films formed potentiodynamically in 0.5 M H_2SO_4 (dU/dt = 20 mVs"-"1). Anisotropy-micro-ellipsometry (AME) was employed to determine the crystallographic orientation of the substrate grains along with passive film thickness and crystallinity in dependence on the anodization potential. Both the isotropic (amorphous) TiO_2- and the anisotropic (crystalline) ZrO_2-films exhibit a systematic dependence of film thickness on the grain orientation. Local LASER-scanning photocurrent measurements (#lambda#=257 nm) on the same grains likewise show a heterogeneity of the photoelectrochemical reactivity in all cases. This is quantitatively explained by the results from local electrochemical ...

1998-03-01

325

In situ scanning tunneling microscopy study of the structure of the hydroxylated anodic oxide film formed on Cr(110) single-crystal surfaces  

Energy Technology Data Exchange (ETDEWEB)

The structure of hydroxylated oxide films (passive films) formed on Cr(110) in 0.5 M H{sub 2}SO{sub 4} at +0.35, +0.55, and +0.75 V/SHE has been investigated by in situ scanning tunneling microscopy (STM). Cathodic reduction pretreatments at {minus}0.54, {minus}0.64, and {minus}0.74 V/SHE destroy the well-defined topography of the single-crystal electrode and they have been excluded from the passivation procedure. Two different passive film structures have been observed, depending on the potential and time of passivation. At low potential (+0.35 V/SHE), the passive film, consisting mostly of chromium hydroxide, has a noncrystalline and granular structure whose roughness suggests local variations of thickness of ca. {+-} 0.5 nm. A similar structure is observed at higher potential (+0.55 V/SHE), but only for a short polarization time. For longer polarization at 0.55 V/SHE, and at higher potentials (+0.75 V/SHE), a crystalline structure is formed; the higher the ...

1999-09-16

326

High-resolution sequence stratigraphy of Lower-Middle Guadalupian outcrops, western Guadalupe Mountains, Texas and New Mexico  

Energy Technology Data Exchange (ETDEWEB)

The authors describe parts of three third-order depositional sequences and their associated system tracts within seismic-scale outcrops of the Lower-Middle Guadalupian Northwestern shelf-to-Delaware basin transition. These sequences are well exposed along a 20-km dip-oriented transect in the western Guadalupe Mountains, Texas and New Mexico. Systems tracts are defined on the basis of lithofacies distribution, stratal geometry, and bounding (stratal termination) surfaces. These Lower-Middle Guadalupian sequences record (1) carbonate platform retrogradation, basin margin erosion, and sediment starvation followed by platform aggradation and progradation (lower San Andres Formation-Cutoff Formation; transgressive and highstand systems tracts), (2) major basin infill by terrigenous clastics bypassed over the underlying lower San Andres highstand carbonate bank and development of a shelf-margin-restricted carbonate bank and coeval base-of-slope apron (Brushy Canyon Formation, Cherry Canyon ...

1990-05-01

327

GOCE, Satellite Gravimetry and Antarctic Mass Transports  

Science.gov (United States)

In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth's gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient components V xx , V yy , V zz and V xz (second-order derivatives of the gravity potential V) with high precision and V xy , V yz with low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity mission, launched in 2002. While GRACE is designed to ...

2011-03-01

328

Equatorial scintillation model. Technical report, 1 February 1983-30 April 1985  

Energy Technology Data Exchange (ETDEWEB)

Radiowave scintillation in the presence of natural and/or high-altitude nuclear disturbances has the potential to disrupt numerous transionospheric radio and radar systems. This report develops a model characterizing the plasma-density irregularities that produce scintillation in the naturally disturbed equatorial F layer. The model is incorporated into Program WBMOD along with subroutines for computing both link geometry and scintillation indices, the latter by means of phase screen diffraction theory. The model is based on similarly extensive analysis of wideband data from two equatorial stations. It describes irregularities at an effective height of 350 km that are isotropic across the geomagnetic field and elongated by a factor of 50 along the field and whose one-dimensional spatial power spectrum obeys a single-regime power law with a (negative) spectral index of 1.5. The height-integrated spectral strength of the irregularities is modeled as a function of ...

1985-09-30

329

Effects of mesh-assisted carbon plasma immersion ion implantation on the surface properties of insulating silicon carbide ceramics  

International Nuclear Information System (INIS)

Plasma immersion ion implantation (PIII) is an effective materials modification and synthesis technique but has seldom been applied to ceramic materials due to the high electrical resistance that reduces the ion bombardment energy and sometimes causes serious electrical arcing in the instrument. Even in cases where PIII is applicable, the surface properties of the implanted insulating materials can be seriously affected due to the low ion energy and materials damage from electrical arcing. In order to enhance the surface and mechanical properties such as wear resistance of ceramic materials used in many industrial applications, surface modification is needed. In this work, we conduct carbon implantation into sintered #alpha#-SiC (silicon carbides that are widely used in vacuum ceramic bearings) using mesh-assisted plasma immersion ion implantation to enhance the surface properties. The use of a conducting grid is necessitated by the high electrical resistance that induces a large ...

2004-03-01

330

Effects of ion-induced electron emission on magnetron plasma instabilities  

International Nuclear Information System (INIS)

Some magnetron sputtering systems experience rapid oscillations in the current and voltage of the plasma discharge after several hours when equipped with certain targets. These oscillations often lead to the plasma becoming extinguished, a condition known as ''flame-out.'' This article details the study of two 90% W--10% Ti magnetron targets which differed in density. The higher density targets sometimes experienced flame-out after approximately 3 h of sputtering. The less dense material could be sputtered for the entire 15 h life of the target. Scanning electron microscopy pictures and atomic composition depth profiles were obtained using Auger electron spectroscopy. In addition, a Colutron-based ion source with a high vacuum system was used to measure ion-induced secondary electron emission coefficients as a function of energy, ion specie, and gas coverage. Analysis of the sample from the group that suffers flame-out showed large regions of pure titanium in the interior of the sample ...

331

Depositional and dissolutional processes and their resulting thinning patterns within the Middle Devonian Prairie Formation, Williston basin, North Dakota and Montana  

Science.gov (United States)

Within the Williston basin, thickness variations of the Prairie Formation are common and are interpreted to originate by two processes: differential accumulation of salt during deposition and differential removal of salt by dissolution. Unambiguous evidence for each process is rare because the Prairie/Winnipegosis interval is seldom cored within the US portion of the basin. Therefore, indirect methods, using well logs, provide the principal method for identifying characteristics of the two processes. The results of this study indicate that the two processes can be distinguished using correlations within the Prairie Formation. Several regionally correlative brining-upward and probably shoaling-upward sequences occur within the Prairie Formation. Near the basin center, the lowermost sequence is transitional with the underlying Winnipegosis Formation. This transition is characterized by thinly laminated basal carbonates that become increasingly interbedded with anhydrites of the ...

1988-07-01

332

Computed Tomography diagnosis of skeletal involvement in multiple myeloma  

International Nuclear Information System (INIS)

The authors assess the role of Computed Topography in the diagnosis and management of multiple myeloma (MM) and investigate if Computed Tomography findings can influence the clinical approach, prognosis and treatment. 273 multiple myeloma patients submitted to Computed Tomography June 1994, to December, 1996. The patients were 143 men and 130 women (mean age: 65 years): 143 were stage I, 38 stage II and 92 stage III according to Durie and Salomon's clinical classification. All patients were submitted to blood tests, spinal radiography and Computed Tomography, the latter with serial 5-mm scans on several vertebral bodies. Computed Tomography despicted vertebral arch and process involvement in 3 cases with the vertebral pedicle sign. Moreover, Computed Tomography proved superior to radiography in showing the spread of myelomatous masses into the soft tissues in a case with solitary permeative lesion in the left public bone, which facilitated subsequent biopsy. As for ...

1994-06-01

333

Comparison and validation of two high-resolution weather forecast models at Frankfurt Airport  

Energy Technology Data Exchange (ETDEWEB)

In recent years the 'Nowcasting Wake Vortex Impact Variables' model NOWVIV has been developed at the Deutsches Zentrum fuer Luft- und Raumfahrt, DLR, to forecast weather parameters in airport environments. The German Meteorological Service, DWD, employs his COSMO-DE model (COnsortium for Small scale Modelling-DEutschland) for operational forecasts in Germany. A systematic comparison of model output from NOWVIV and a derivate of COSMO-DE, named COSMO-FRA, is presented. Both models are centred at Frankfurt Airport with horizontal resolutions of 2.1 km and 2.8 km, respectively. In the DLR Project Wetter and Fliegen the COSMO-FRA model will replace the NOWVIV model and become a key component in the future rapid update cycle for adverse weather predictions at the airports of Frankfurt and Munich. The forecast vertical profiles of runway crosswind, head/tail wind, temperature, and turbulent kinetic energy (TKE) are validated against Wind and Temperature ...

2009-10-15

334

Change in runoff characteristics of alpine flowing waters caused by the use of hydroelectric power and its effects on the macro-benthos  

International Nuclear Information System (INIS)

A typical form of change in runoff characteristics caused by the widespread use of hydroelectric power in Switzerland is the intermittent draining (torrent operation). It is the aim of the present work to help elucidate possible consequences of these changes in drain onto the benthobiocoenosis. The study was carried through on the Secklisbach at Oberrickenbach (in the semicanton of Nidwalden) and one of its side streamlets (800m above sea level). The macroinvertebrate coenosis was studied at four locations with similar conditions of drainage basin, population density and topography but varying in the degree of impairment to the draining. There were monthly benthos samples taken using a Surber sampling-device. Results show that the locations not only varied in drain, but also in temperature, this being a consequence of water storage by the power plant. The readings pointed out different values for the locations in daily average temperature, day amplitudes and ...

335

Borehole geophysics for delineating the geological structure in the Sakonishi prospect, the Hida area, Japan; Hida chiiki Sako nishi chiku ni okeru boring ko riyo butsuri tansa ni yoru chishitsu kozo kaiseki  

Energy Technology Data Exchange (ETDEWEB)

In order to discuss effectiveness of physical exploration in the Sakonishi prospect in the Hida area, physical exploration was carried out by utilizing bored wells. This area contains the Kamioka mine, one of the major base metal mines in Japan, where electrical exploration has been attempted several times in the past. No effective results have been obtained, however, because specific resistance contrast between mine beds and base rocks is too small, and the topography is too steep making site workability inferior. As part of the investigations on geological structures over wide areas, electrical logging (specific resistance and natural potential) was performed in fiscal 1995 and 1996 by utilizing the boreholes. Induced polarization logging was also conducted on the same boreholes. A traverse line on the ground with a length of 600 m and boreholes were used to execute specific resistance tomography. Clear extraction was possible on a fault structure which is ...

1997-05-27

336

Applications of high resolution sequence stratigraphy in North Sea syn-rift reservoir correlation and development  

Energy Technology Data Exchange (ETDEWEB)

Tectonically active basins may host a spectrum of sequence stratigraphic expressions previously considered to be spatially mutually exclusive. In low accommodation areas with high sediment supply, fourth order eustatic cyclicity results in high frequency sequence sets while within rapidly subsiding areas, time-equivalent Type-2 sequences are expressed by highly asymmetrical coarsening upward successions, resembling large parasequences. In the shallow marine Fulmar Formation, of the U.K. North Sea Central Graben a sequence boundary and overlying lowstand deposits, which illustrate the effects of laterally variable subsidence rate and intrabasinal topography on the expression of a eustatic sea-level fall, lie between the Glosense and Serratum (J54a and J54b) maximum flooding surfaces. The syn-rift physiography comprises major tilted fault blocks, with the Central Graben dipping parallel to the major faults, simulating a ramp setting. Where the throw of the faults ...

1995-08-01

337

Age-Related Long-Term Functional Results after Riboflavin UV A Corneal Cross-Linking.  

Science.gov (United States)

Purpose. To report a comparative prospective long-term functional analysis after Riboflavin UV A corneal cross-linking (CXL) in three different age groups of patients affected by progressive keratoconus (KC). Methods. Functional analysis comprised paediatric patients (?18 years) included 152 eyes (29.5%); intermediate group (19-26 years) 286 eyes (55.4%), and adults (?27 years) 78 eyes (15.1%). CXL was performed according to the Siena protocol by using the Vega CBM (Caporossi-Baiocchi-Mazzotta) X linker (CSO, Florence, Italy) at Siena University by the same authors. Pre- and post-op examinations included UCVA, BSCVA, corneal topography, and surface aberrometry (CSO Eye Top, Florence, Italy), at 48 months followup. Results. At 48 months followup paediatrics, intermediate, and adult patients showed a mean gain in UCVA of +0.2, +0.14 and +0.12 Snellen lines. BSCVA gained by a mean of +0.21, +0.2, and +0.1 Snellen lines. K(max) was reduced by a mean value of -0.9?D, ...

2011-08-04

338

Ultra high-speed (508 MHz) beam position digital feedback system  

Energy Technology Data Exchange (ETDEWEB)

The B-Factory which is constructed by National Laboratory for High Energy Physics is the device for elucidating the breakdown of symmetry of matter and antimatter by studying the behavior of B mesons which are generated in large quantity when the electrons and the positrons which are accelerated to light velocity level are collided. In order to maintain electron beam-positron beam bunch circling the ring at light velocity stably, the instability of the coupled bunch must be overcome. For this purpose, the ultrahigh speed beam position digital feedback control system was developed. This system is composed of the high speed input-output substrate using GaAs LSI, the feedback computation substrate using complementary metal oxide semiconductor and the memory mounted on it, and the real time operation device. The development of both substrates and their functions are explained. The real time data collection and the change of computation parameters for specific bunch in ...

1997-02-01

339

Three-Dimensional Wing Kinematics and Aerodynamic Characteristics of a Beetle in Free Flight  

Science.gov (United States)

Detailed three dimensional wing kinematics and aerodynamic characteristics are experimentally presented for the free flight of a beetle, Allomyrina dichotoma, which has a pair of elytra (fore wings) and hind wings. The kinematic parameters of the wing motion, such as the wing tip trajectory, angle of attack, torsion angle, and camber deformation, are obtained from a 3D reconstruction technique that involves the use of two or three synchronized high-speed cameras to digitize various points marked on the wings. Our data show outstanding characteristics of wing deformation and flexibility in the free flight of the beetle. To find out the mechanism of aerodynamic force, the leading edge vortex (LEV) and trailing edge vortex (TEV) on both elytron and hind wing were observed by using smoke wire visualization and digital particle image velocimetry (DPIV) technique. Qualitative smoke lines in the region of the most intent vortex shedding demonstrate ...

2010-11-01

340

The Sloan Digital Sky Survey DR7 Spectroscopic M Dwarf Catalog I: Data  

CERN Document Server

We present a spectroscopic catalog of 70,841 visually inspected M dwarfs from the seventh data release of the Sloan Digital Sky Survey (SDSS). For each spectrum, we provide measurements of the spectral type, a number of molecular bandheads, and the H-alpha, H-beta, H-gamma, H-delta and Ca II K emission lines. In addition, we calculate the metallicity-sensitive parameter zeta and identify a relationship between zeta and the g-r and r-z colors of M dwarfs. We assess the precision of our spectral types (which were assigned by individual examination), review the bulk attributes of the sample, and examine the magnetic activity properties of M dwarfs, in particular those traced by the higher order Balmer transitions. Our catalog is cross-matched to Two Micron All Sky Survey (2MASS) infrared data, and contains photometric distances for each star. Lastly, we identify eight new late-type M dwarfs that are possibly within 25 pc of the Sun. Future studies will use these data ...

2011-01-01

341

The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III  

Energy Technology Data Exchange (ETDEWEB)

The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with new instrumentation and new surveys focused on Galactic structure and chemical evolution, measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly{alpha} forest, and a radial velocity search for planets around {approx}8000 stars. This paper describes the first data release of SDSS-III (and the eighth counting from the beginning of the SDSS). The release includes 5-band imaging of roughly 5200 deg{sup 2} in the Southern Galactic Cap, bringing the total footprint of the SDSS imaging to 14,555 deg{sup 2}, or over a third of the Celestial Sphere. All the imaging data have been reprocessed with an improved sky-subtraction algorithm and a final, self-consistent recalibration and flat-field determination. This release also includes all data from the second phase of the Sloan Extension for Galactic Understanding and Evolution (SEGUE-2), consisting of ...

2011-01-01

342

Surface brightness and effective radius for elliptical galaxies  

International Nuclear Information System (INIS)

Seeing convolved two-dimensional de Vaucouleurs profiles have been fitted to digital images of the brightest elliptical galaxies in two nearby groups of galaxies and three clusters of galaxies with redshifts in the range 0.06 to 0.15. The digital images were created by scanning electronographic plates obtained by the use of several versions of the RGO electronographic camera. The linear relation between effective surface brightness #mu#/sub e/ and the logarithm of the effective radius r/sub e/, first discovered by Kormendy to be valid for nearby elliptical galaxies, is found to be equally valid for the largest and brightest galaxies in rich clusters of galaxies. The apparent universal nature of that relation indicates that the same type of processes might have been involved during the formation of all ellipticals from cD galaxies in clusters to fainter ellipticals in small groups. It is suggested that the (I/sub e/,r/sub e/) relation is not ...

343

Standardization of "2"4"1Am by digital coincidence counting, liquid scintillation counting and defined solid angle counting  

International Nuclear Information System (INIS)

The nuclide "2"4"1Am decays by alpha emission to "2"3"7Np. Most of the decays (84.6%) populate the excited level of "2"3"7Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of "2"4"1Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods.

2009-09-07

344

Skip-webs: Efficient distributed data structures for multi-dimensional data sets  

DEFF Research Database (Denmark)

We present a framework for designing efficient distributed data structures for multi-dimensional data. Our structures, which we call skip-webs, extend and improve previous randomized distributed data structures, including skipnets and skip graphs. Our framework applies to a general class of data querying scenarios, which include linear (one-dimensional) data, such as sorted sets, as well as multi-dimensional data, such as d-dimensional octrees and digital tries of character strings defined over a fixed alphabet. We show how to perform a query over such a set of n items spread among n hosts using O(log n / log log n) messages for one-dimensional data, or O(log n) messages for fixed-dimensional data, while using only O(log n) space per host. We also show how to make such structures dynamic so as to allow for insertions and deletions in O(log n) messages for quadtrees, octrees, and digital tries, and O(log n / log log n) messages for ...

2005-01-01

345

Ranking Scientific Publications Based on Their Citation Graph  

CERN Document Server

CDS Invenio is the web-based integrated digital library system developed at CERN. It is a suite of applications which provides the framework and tools for building and managing an autonomous digital library server. Within this framework, the goal of this project is to implement new ranking methods based on the bibliographic citation graph extracted from the CDS Invenio database. As a first step, we implemented the Citation Count as a baseline ranking method. The major disadvantage of this method is that all citations are treated equally, disregarding their importance and their publication date. To overcome this drawback, we consider two different approaches: a link-based approach which extends the PageRank model to the bibliographic citation graph and a time-dependent approach which takes into account time in the citation counts. In addition, we also combined these two approaches in a hybrid model based on a time-dependent PageRank. In the ...

2009-01-01

346

Power law correlations in galaxy distribution and finite volume effects from the Sloan Digital Sky Survey Data Release Four  

CERN Document Server

We discuss the estimation of galaxy correlation properties in several volume limited samples, in different sky regions, obtained from the Fourth Data Release of the Sloan Digital Sky Survey. The small scale properties are characterized through the determination of the nearest neighbor probability distribution. By using a very conservative statistical analysis, in the range of scales [0.5,~30] Mpc/h we detect power-law correlations in the conditional density in redshift space, with an exponent \\gamma=1.0 \\pm 0.1. This behavior is stable in all different samples we considered thus it does not depend on galaxy luminosity. In the range of scales [~30,~100] Mpc/h we find evidences for systematic unaveraged fluctuations and we discuss in detail the problems induced by finite volume effects on the determination of the conditional density. We conclude that in such range of scales there is an evidence for a smaller power-law index of the conditional density. However we ...

2006-01-01

347

PROPERTIES OF DISKS AND BULGES OF SPIRAL AND LENTICULAR GALAXIES IN THE SLOAN DIGITAL SKY SURVEY  

International Nuclear Information System (INIS)

A bulge-disk decomposition is made for 737 spiral and lenticular galaxies drawn from a Sloan Digital Sky Survey galaxy sample for which morphological types are estimated. We carry out the bulge-disk decomposition using the growth curve fitting method. It is found that bulge properties, effective radius, effective surface brightness, and also absolute magnitude, change systematically with the morphological sequence; from early to late types, the size becomes somewhat larger, and surface brightness and luminosity fainter. In contrast, disks are nearly universal, their properties remaining similar among disk galaxies irrespective of detailed morphologies from S0 to Sc. While these tendencies were often discussed in previous studies, the present study confirms them based on a large homogeneous magnitude-limited field galaxy sample with morphological types estimated. The systematic change of bulge-to-total luminosity ratio, B/T, along the morphological sequence is ...

2009-11-01

348

On-line video image processing system for real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

The neutron radiography system installed at the E-2 experimental hole of the KUR (Kyoto University Reactor) has been used for some NDT applications in the nuclear field. The on-line video image processing system of this facility is introduced in this paper. A 0.5 mm resolution in images was obtained by using a super high quality TV camera developed for X-radiography viewing a NE-426 neutron-sensitive scintillator. The image of the NE-426 on a CRT can be observed directly and visually, thus many test samples can be sequentially observed when necessary for industrial purposes. The video image signals from the TV camera are digitized, with a 33 ms delay, through a video A/D converter (ADC) and can be stored in the image buffer (32 KB DRAM) of a microcomputer (Z-80) system. The digitized pictures are taken with 16 levels of gray scale and resolved to 240 x 256 picture elements (pixels) on a monochrome CRT, with the capability also to display 16 ...

1983-09-15

349

Fuji computed radiography (FCR) for the diagnosis of spinal disorders  

International Nuclear Information System (INIS)

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the cervicothoracic region, where it is usually difficult to obtain clear cervicothoracic films in conventional radiography. We can obtain much precise ...

1987-01-01

350

Frame Selected Approach for Hiding Data within MPEG Video Using Bit Plane Complexity Segmentation  

CERN Document Server

Bit Plane Complexity Segmentation (BPCS) digital picture steganography is a technique to hide data inside an image file. BPCS achieves high embedding rates with low distortion based on the theory that noise-like regions in an image's bit-planes can be replaced with noise-like secret data without significant loss in image quality. . In this framework we will propose a collaborate approach for select frame for Hiding Data within MPEG Video Using Bit Plane Complexity Segmentation. This approach will invent high secure data hidden using select frame form MPEG Video and furthermore we will assign the well-built of the approach; during this review the author will answer the question why they used select frame steganography. In additional to the security issues we will use the digital video as a cover to the data hidden. The reason behind opt the video cover in this approach is the huge amount of single frames image per sec which in turn overcome the ...

2009-01-01

351

Evaluation of computer-aided detection of lesions in mammograms obtained with a digital phase-contrast mammography system  

Energy Technology Data Exchange (ETDEWEB)

A computer-aided detection (CAD) system was evaluated for its ability to detect microcalcifications and masses on images obtained with a digital phase-contrast mammography (PCM) system, a system characterised by the sharp images provided by phase contrast and by the high resolution of 25-{mu}m-pixel mammograms. Fifty abnormal and 50 normal mammograms were collected from about 3,500 mammograms and printed on film for reading on a light box. Seven qualified radiologists participated in an observer study based on receiver operating characteristic (ROC) analysis. The average of the areas under ROC curve (AUC) values for the ROC analysis with and without CAD were 0.927 and 0.897 respectively (P = 0.015). The AUC values improved from 0.840 to 0.888 for microcalcifications (P = 0.034) and from 0.947 to 0.962 for masses (P = 0.025) respectively. The application of CAD to the PCM system is a promising approach for the detection of breast cancer in its early stages. (orig.)

2009-12-15

352

Efficient calculation of the worst-case error and (fast) component-by-component construction of higher order polynomial lattice rules  

CERN Document Server

We show how to obtain a fast component-by-component construction algorithm for higher order polynomial lattice rules. Such rules are useful for multivariate quadrature of high-dimensional smooth functions over the unit cube as they achieve the near optimal order of convergence. The main problem addressed in this paper is to find an efficient way of computing the worst-case error. A general algorithm is presented and explicit expressions for base~2 are given. To obtain an efficient component-by-component construction algorithm we exploit the structure of the underlying cyclic group. We compare our new higher order multivariate quadrature rules to existing quadrature rules based on higher order digital nets by computing their worst-case error. These numerical results show that the higher order polynomial lattice rules improve upon the known constructions of quasi-Monte Carlo rules based on higher order digital nets.

2011-01-01

353

Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures  

Energy Technology Data Exchange (ETDEWEB)

AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon ...

2002-04-01

354

Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures  

International Nuclear Information System (INIS)

AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon ...

2002-04-01

355

Digital luminescent radiography: A substitute for conventional chest radiography?  

International Nuclear Information System (INIS)

The image quality of digital luminescent radiography (DLR) is sufficient for routine biplane chest radiography and for follow-up studies of heart size, pulmonary congestion, coin lesions, infiltrations, atelectasis, pleural effusions, and mediastinal and hilar lymph node enlargement. Chest radiography in the intensive care unit may in most cases be performed using the DLR technique. there is no need for repeat shots because of incorrect exposure, and the position of catheters, tubes, pacemakers, drains and artificial heart valves, the mediastinum, and the retrocardiac areas of the left lung are more confidently assessed on the edge-enhanced DLR films than on conventional films. Nevertheless, DLR is somewhat inferior to conventional film-screen radiography of the chest as it can demonstrate or rule out subtle pulmonary interstitial disease less confidently. There is no reduction of radiation exposure of the chest in DLR compared with modern film-screen systems. As a ...

356

Digital image precessing for neutron television fluoroscopic system and its application to neutron computed tomography  

Energy Technology Data Exchange (ETDEWEB)

The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the reconstructed image. The image quality could be satisfactory to distinguish acrylic ...

1984-09-01

357

Digital image precessing for neutron television fluoroscopic system and its application to neutron computed tomography  

International Nuclear Information System (INIS)

The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the reconstructed image. The image quality could be satisfactory to distinguish acrylic ...

1984-01-01

358

Determination of Inter-Phase Line Tension in Langmuir Films  

CERN Document Server

A Langmuir film is a molecularly thin film on the surface of a fluid; we study the evolution of a Langmuir film with two co-existing fluid phases driven by an inter-phase line tension and damped by the viscous drag of the underlying subfluid. Experimentally, we study an 8CB Langmuir film via digitally-imaged Brewster Angle Microscopy (BAM) in a four-roll mill setup which applies a transient strain and images the response. When a compact domain is stretched by the imposed strain, it first assumes a bola shape with two tear-drop shaped reservoirs connected by a thin tether which then slowly relaxes to a circular domain which minimizes the interfacial energy of the system. We process the digital images of the experiment to extract the domain shapes. We then use one of these shapes as an initial condition for the numerical solution of a boundary-integral model of the underlying hydrodynamics and compare the subsequent images of the experiment to ...

2007-01-01

359

Design improvements and operational experience of programmable digital comparator system  

International Nuclear Information System (INIS)

Application of Programmable Digital Comparator System (PDCS) in NPP is to monitor large number of plant parameters and generate contact outputs for reactor trip, reactor setback, process interlocks etc. when parameters cross their operational bounds. Till NAPS these functions are achieved through individual Indicating Alarm Meters (IAM). PDCS used for the first time in KAPS replaces these IAMs. Since its inception, PDCS has undergone improvements in design, incorporates additional functionalities/enhanced features. Dedicated PDCS is provided in TAPP-3 and 4 for protection function. System re-configurability, on-line inter channel comparison of safety critical process parameters' values, Graphic User Interface etc. are other enhancements. From KAPS to TAPP-4 system has given many years of almost trouble-free operation. Commissioning of TAPP-3 system has been very smooth. Objective of the paper is to describe the advantage of the new system, its operating experience, ...

2006-11-13

360

Comparative experimental study of dual energy subtraction and conventional digital radiography on chest  

International Nuclear Information System (INIS)

Objective: To compare the efficiency of dual energy subtraction and conventional direct digital radiography in signal detecting ability. Methods: 200 plastic balls which were 4 mm in diameter were taken as signals and were placed on a 10 cm thick plastic board and the right upper thorax of a healthy volunteer. The signals were examined by DES and CDR separately and were estimated by 3 radiologists with 5-value-differentiation method. ROC curve analysis was made by ROC kit software. Results: when signals on plastic board were detected by CDR and DES, ROC curve analysis indicated that there was no significant difference (P=0.4851 > 0.05, two-tailed) between the area under the ROC curves of the two methods (Az=0.9931 for CDR and Az=0.9879 for DES). The difference was significant (P=0.0002 <0.01, two-tailed) between the area under the ROC curves of CDR and DES (Az=0.7276 for CDR and Az=0.8561 for DES), when the signals on the right upper thorax of a volunteer ...

2005-06-01

361

Automated segmentation and quantitative characterization of radiodense tissue in digitized mammograms  

International Nuclear Information System (INIS)

Mammography has emerged as a reliable non-invasive technique for the early detection of breast cancer--the second leading cause of cancer-related mortality among American women. The radiographic appearance of the female breast consists of radiolucent (dark) regions due to fat and radiodense (light) regions due to connective and epithelial tissue. The amount of radiodense tissue can be used as a marker for predicting breast cancer risk. This paper presents the development of an algorithm for estimating the percentage of radiodense tissue in a digitized mammogram. The technique involves determining a dynamic threshold for segmenting radiodense indications in mammograms. Both the mammographic image and the threshold are modeled as Gaussian random variables. This work is intended to support a concurrent study at the Fox Chase Cancer Center (FCCC) exploring the association between dietary patterns and breast cancer risk. Mammograms have been obtained from an existing ...

2002-05-25

362

Assessment of the effects of pixel loss on image quality in direct digital radiography  

Energy Technology Data Exchange (ETDEWEB)

Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can ...

2004-03-21

363

Assessment of the effects of pixel loss on image quality in direct digital radiography  

International Nuclear Information System (INIS)

Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can reveal small changes in image quality ...

2004-03-21

364

Are Optically-Selected Quasars Universally X-Ray Luminous? X-Ray/UV Relations in Sloan Digital Sky Survey Quasars  

CERN Document Server

We analyze archived Chandra and XMM-Newton X-ray observations of 536 Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasars (QSOs) at 1.7 <= z <= 2.7 in order to characterize the relative UV and X-ray spectral properties of QSOs that do not have broad UV absorption lines (BALs). We constrain the fraction of X-ray weak, non-BAL QSOs and find that such objects are rare; for example, sources underluminous by a factor of 10 comprise $\\la$2% of optically-selected SDSS QSOs. X-ray luminosities vary with respect to UV emission by a factor of $\\la$2 over several years for most sources. UV continuum reddening and the presence of narrow-line absorbing systems are not strongly associated with X-ray weakness in our sample. X-ray brightness is significantly correlated with UV emission line properties, so that relatively X-ray weak, non-BAL QSOs generally have weaker, blueshifted CIV$\\lambda$1549 emission and broader CIII]$\\lambda$1909 lines. The CIV emission ...

2008-01-01

365

Applications of a downhole programmable microprocessor for a geothermal borehole inspection tool  

Energy Technology Data Exchange (ETDEWEB)

The high-temperature scanning borehole inspection system is currently being developed jointly by the Los Alamos National Laboratory (LANL) and Westfalische Berggewerkschaftskasse (WBK) of West Germany. The downhole instrument is a digital televiewer that utilized a microprocessor to digitize, process and transmit the acoustic information to the surface acquisition and control system. The primary operation of the downhole acoustic assembly uses a piezoelectric crystal acting as a receiver-transmitter which is mounted on the rotating head. The crystal emits a burst of acoustic energy that propagates through the borehole fluid with a portion of the energy reflected by the borehole wall back to the crystal. The time of travel and the amplitude of the reflected signal are conditioned by the microprocessor and transmitted along with other pertinent data to the surface data processing center. This instrument has been designed specifically for use in ...

1987-01-01

366

Analysis of lightning fault detection, location and protection on short and long transmission lines using Real Time Digital Simulation  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to present an analysis of lightning fault detection, location and protection using numeric distance relays applied in high voltage transmission lines, more specifically in the 500 kV transmission lines of CEMIG (Brazilian Energy Utility) between the Vespasiano 2 - Neves 1 (short line - 23.9 km) and Vespasiano 2 - Mesquita (long line - 148.6 km) substations. The analysis was based on the simulations results of numeric distance protective relays on power transmission lines, realized in September 02 to 06, 2002, at Siemens AG's facilities (Erlangen - Germany), using Real Time Digital Simulator (RTDS{sup TM}). Several lightning faults simulations were accomplished, in several conditions of the electrical power system where the protective relays would be installed. The results are presented not only with the times of lightning faults elimination, but also all the functionality of a protection system, including the correct detection, ...

2007-07-01

367

Analysis of algorithms for ultra high speed relays for the protection of high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

The object of this research is the evaluation of the performance of ultra high speed relays (UHSR's) used for protection of a-c transmission lines. For purposes of this report, these are relays whose response time is less than a quarter of a cycle of the 60 Hz wave (i.e. 4.167 ms.). To identify relaying schemes that may comply with this definition, a literature survey was undertaken. The selected relays were studied in detail and modeled on a digital computer. A theoretical description of these relays is presented. Records of real transient data as well as of simulated data were used as input to the digital models of relays. The real data were recorded by means of monitoring stations connected to the Florida Power and Light Company transmission lines. The simulated data were obtained by modeling the relevant parts of the utility's transmission system using a University of British Columbia simplified version of the well known ...

1984-01-01

368

An on-line video image processing system for real-time neutron radiography  

International Nuclear Information System (INIS)

The neutron radiography system installed at the E-2 experimental hole of the KUR (Kyoto University Reactor) has been used for some NDT applications in the nuclear field. The on-line video image processing system of this facility is introduced in this paper. A 0.5 mm resolution in images was obtained by using a super high quality TV camera developed for X-radiography viewing a NE-426 neutron-sensitive scintillator. The image of the NE-426 on a CRT can be observed directly and visually, thus many test samples can be sequentially observed when necessary for industrial purposes. The video image signals from the TV camera are digitized, with a 33 ms delay, through a video A/D converter (ADC) and can be stored in the image buffer (32 KB DRAM) of a microcomputer (Z-80) system. The digitized pictures are taken with 16 levels of gray scale and resolved to 240 x 256 picture elements (pixels) on a monochrome CRT, with the capability also to display 16 ...

1983-09-01

369

An adaptive self-optimizing power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

A self-optimizing pole-shifting control algorithm has been developed for an adaptive power system stabilizer (APSS) to improve its dynamic performance and autonomous operation. The proposed algorithm deals with the system frequency and time domain characteristics simultaneously to guarantee stability and to enhance the performance of the closed-loop system. The mechanism of discrete control system control limits influencing the closed loop system behaviour is studied. Short-term behaviour is studied by introducing the concept of a short-term behaviour index. With the introduction of dynamic control limits, an effective discrete control system design method is proposed. A PSS oriented power system dynamics simulation package (PSDSP) has been developed. Using the PSDSP, simulation studies were performed with the proposed APSS applied to a single machine and a multi machine power system. The performance of the APSS is satisfactory and is discussed. An Intel iSBC386/21 processor was ...

1994-01-01

370

A study on the optimal replacement periods of digital control computer's components of Wolsung nuclear power plant unit 1  

International Nuclear Information System (INIS)

Due to the failure of the instrument and control devices of nuclear power plants caused by aging, nuclear power plants occasionally trip. Even a trip of a single nuclear power plant (NPP) causes an extravagant economical loss and deteriorates public acceptance of nuclear power plants. Therefore, the replacement of the instrument and control devices with proper consideration of the aging effect is necessary in order to prevent the inadvertent trip. In this paper we investigated the optimal replacement periods of the control computer's components of Wolsung nuclear power plant Unit 1. We first derived mathematical models of optimal replacement periods to the digital control computer's components of Wolsung NPP Unit 1 and calculated the optimal replacement periods analytically. We compared the periods with the replacement periods currently used at Wolsung NPP Unit 1. The periods used at Wolsung is not based on mathematical analysis, but on empirical knowledge. As a ...

1993-01-01

371

Three-frame Algorithm of Car Path Reconstruction from Airborne Traffic Data  

CERN Document Server

The airborne traffic monitoring system forms a novel technology of detecting vehicle motion. An optical digital camera located on an airborne platform produces a series of images which then are processed to recognized the fixed vehicles. In this way the video data are converted into the time sequence of frames containing the vehicle coordinates. In the present work a three-frame algorithm is developed to identify the succeeding vehicle positions. It is based on finding the neighboring points in the frame sequence characterized by minimal acceleration. To verify and optimize the developed algorithm a ``Virtual Road'' simulator was created. Finally available empirical data are analyzed using the created algorithm.

2007-01-01

372

The full scope simulator hardware I/O realization in Daya bay nuclear power station  

International Nuclear Information System (INIS)

The full scope simulator in Daya Bay Nuclear Power Station is imported from THOMSON-CSF company in France. It is a large facility, using digital simulation technology, that simulate the main control room of Daya Bay Nuclear Power Station with the high fidelity. It is used for training operators; system analyzing including operation procedure verification. The input output interface system of the simulator is the bridge of the information exchange between instrumentation and the computer. From the point of view of data transfer, this paper discusses the operation principle of the I/O interface system.

373

THE DEVIL AND CUSTOMER RELATIONSHIP MANAGEMENT  

British Library Electronic Table of Contents (United Kingdom)

The paper takes as its starting point the diffusion of ICT applications associated with so-called 'customer relationship management' (CRM). CRM encourages organisations to shift their understanding of customers from an episodic and transaction-based perspective to one that emphasises continuous 'relationship management'. CRM applications thus promise to deliver more, real-time accurate information about consumer habits and behaviours therefore allowing organisations to maximise their extraction of business value. This paper explores the ways in which such inscriptive technologies are not merely referential but also constitutive of contemporary re-presentations and ideals of the consuming subject. Focusing on what we might call the 'digital doubles' of customer relationship management the a...

2010-01-01

374

State-of-the-art technique for power system stabilizer tuning  

Energy Technology Data Exchange (ETDEWEB)

Power System Stabilizers (PSS) have broad application throughout the world. PSS application requires careful tuning which is usually accomplished in the field with the generator and power system in an abnormal condition. Recently developed equipment which combines fast Fourier transform capability with digital computer technique provides a means of PSS tuning which is faster and more accurate than was previously obtainable. This paper describes a PSS tuning test conducted using the new technique. The advantages will be apparent to the reader. The described test is very poignant as evidenced by two unexpected occurrences of instability.

1983-03-01

375

Prospective application of advanced series compensation to improve transmission system performance  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the main aspects and results of the planning studies undertaken to evaluate the technical benefits of using Thyristor Controlled Series Compensation (TCSC), in a large 500 kV transmission system (Brazilian North-Northeast system). TCSC controllers design and simplified models for digital non-linear time domain simulations are discussed. The proposed controllers are tuned and used to support the comparative analysis between controlled and fixed series compensation. The relevant conclusions concerning this comparison are highlighted. (author) 2 refs., 14 figs., 3 tabs.

1994-12-31

376

Potential vulnerabilities of nuclear fuel cycle facilities to the year 2000 (Y2K) issue and measures to address them  

International Nuclear Information System (INIS)

The exchange of information and experience among Member Sates is an essential component of the IAEA action plan for addressing the Year 2000 problem. The objective is to enable Member States to identify any gaps in their own conversion programmes, benefit form the experience of others in developing remedial actions and establish the basis for future action to solve remaining problems. Experts in Year 2000 issues particularly those related to digital equipment prepared this report dealing with nuclear fuel cycle facilities

1993-04-18

377

Performance measurements of the Pionier-I 15 m VAWT. Prestatiemetingen aan de Pionier-I 15 m VAWT  

Energy Technology Data Exchange (ETDEWEB)

Pionier-I is a vertical axis wind turbine (VAWT) of the Darrieus-type with a diameter of 15 m. In the month of September 1983 performance and efficiency were measured. Measurements were done with constant rotational speed and with constant tip speed ratio. For the calculation of the possible (theoretical) output of electric power an anemometer was present. Measurement results are conditioned to one digital signal and processed by a microcomputer (Apple II). It becomes evident that the yearly energy output of the Pionier-I is quite well comparable with that of a horizontal axis turbine with the same diameter.

1983-01-01

378

PT3. [SITE 2002 Section].  

Science.gov (United States)

This document contains 142 papers on PT3 (Preparing Tomorrow's Teachers to use Technology) from the SITE (Society for Information Technology & Teacher Education) 2002 conference. Topics covered include: a technology in urban education summit; student professional development; meeting NCATE (National Council of Teachers of English) standards; faculty use of WebCT; preparing teachers for the digital age; technology in K-8 multicultural classrooms; using immersive 360 degree images; consortium building; student evaluation; technology fellows; incentives that facilitate institutional change; impact of a temporary grant; a consortium for outstanding achievement in teaching with technology; changes implemented after technology professional development sessions; Web-based modules for teaching mathematics to minority students; student teaching technology sites; preservice teachers design technology-enhanced learning experiences; planning, implementing, evaluating, and ...

2002-03-01

379

Neutron radiography with the cyclotron, 5  

International Nuclear Information System (INIS)

Reliable facility of cyclotron-based real time neutron radiography system has been developed and applied to some industrial components. The equipment for neutron fluoroscopy is based on a sub-compact cyclotron and a LiF/ZnS (Ag) fluorescent screen viewed by a silicon intensifier target TV camera. The real time image is monitored on a CRT, recorded with a standard video recorder and processed by a digital image processor. The effectiveness of our real time neutron radiograph has been demonstrated to be applicable to not only the dynamic observation but also the magnifying and stereoscopic observation of fluoroscopic images. (author).

1987-01-01

380

Network Security: Concepts  

Science.gov (United States)

Prepared and presented by Professor Raj Jain at Washington University in St. Louis, this series of presentations is designed to introduce computer science students to the fundamentals of network security. Visitors have the option of choosing to download or view the presentations with audio, as individual slides only, or as a single PDF document. Topics here include: security requirements, public key encryption, digital signatures, and confidentiality. This is an excellent site for educators to use in the classroom or as a supplementary resource to introduce students to computer network security. Students may also wish to view or download the presentations to learn the basic concepts of network security.

2008-01-30

381

Making sense of leak detection  

Energy Technology Data Exchange (ETDEWEB)

It is estimated that more than 180.000 kilometres of onshore pipelines will be installed between now and 2012. According to the US Federal Office of Pipeline Safety report (1968-97), the average pipeline suffers one leak per year every 400 miles. This equates to a total of 180 expected leaks per year for a new pipeline alone. Sensornet's continuous real-time Digital Leak Detection monitoring solution has the reach, precision and the speed to provide complete, continuous real-time knowledge (author)

2008-07-01

382

How to start a utility TQM program  

Energy Technology Data Exchange (ETDEWEB)

Huntsville, Alabama Utilities has successfully provided services for over 53 years. However, the quality of service demands from customers are changing every day! Part of this demand is due to updated digital appliances, home and business computers, and automated systems. A quality program was initiated in 1992 as a result of an internal assessment. The Malcolm Baldrige approach was selected which includes seven areas: (1) Leadership; (2) Information and Analysis; (3) Strategic Planning; (4) Human Resource Utilization; (5) Quality Assurance of Products and Services: (6) Quality Results: (7) Customer Satisfaction. Training for and implementation of the Quality program is discussed in detail.

1994-12-31

383

GPLS VME MODULE: A DIAGNOSTIC AND DISPLAY TOOL FOR NSLS MICRO SYSTEMS.  

Energy Technology Data Exchange (ETDEWEB)

The General Purpose Light Source VME module is an integral part of every front-end micro in the NSLS control system. The board incorporates features such as a video character generator, clock signals, time-of-day clock, a VME bus interrupter and general-purpose digital inputs and outputs. This module serves as a valuable diagnostic and real-time display tool for the micro development as well as for the final operational systems. This paper describes the functions provided by the board for the NSLS micro control monitor software.

1999-03-29

384

FCR (Fuji Computed Radiography) in neurosurgery  

Energy Technology Data Exchange (ETDEWEB)

As part of the evolution of computer technology, Fuji Computed Radiography (FCR) has been developed as a new system for radiographical diagnosis. In this system, the X-ray energy is stored on the imaging plate and then converted into digital signals utilizing scanning laser-stimulated luminence. After proper image processing, it offers much more improved information for diagnosis than the conventional film system does. Since April, 1986, we have principally used FCR (System 101) for neurosurgical practice. In this article, we present our recent experience and evaluate its usefulness.

1988-08-01

385

FCR (Fuji Computed Radiography) in neurosurgery  

International Nuclear Information System (INIS)

As part of the evolution of computer technology, Fuji Computed Radiography (FCR) has been developed as a new system for radiographical diagnosis. In this system, the X-ray energy is stored on the imaging plate and then converted into digital signals utilizing scanning laser-stimulated luminence. After proper image processing, it offers much more improved information for diagnosis than the conventional film system does. Since April, 1986, we have principally used FCR (System 101) for neurosurgical practice. In this article, we present our recent experience and evaluate its usefulness. (author).

1988-01-01

386

FADC signal reconstruction for the MAGIC telescope  

Energy Technology Data Exchange (ETDEWEB)

Until April 2007 the Major Atmospheric Gamma ray Imaging Cherenkov (MAGIC) telescope used a 300 MSamples/s flash analog-to-digital converter (FADC) system to sample the shaped photomultiplier tube (PMT) signals produced by the captured Cherenkov photons of air showers. Different algorithms to reconstruct the signal from the read-out samples (extractors) have been implemented and are described and compared. Criteria based on the obtained charge and time resolution/bias are defined and used to judge the different extractors, by applying them to calibration, cosmic and pedestal signals. The achievable charge and time resolution have been derived as functions of the number of incident photo-electrons.

2008-09-11

387

Explosives 92. Conference proceedings  

Energy Technology Data Exchange (ETDEWEB)

17 papers are presented. Topics covered include: the POG system - a new concept in the use of ANFO; demolition of a motorway bridge; presplit and smooth blasting; VIBReX - a predictive code for assessing the effect of blast design on ground vibration; ground vibrations from blasting; digital seismographs; human response to blasting and the effects on planning conditions; landform construction by restoration blasting; use of small diameter explosives; efficient priming; safety management in the explosives industry; and the law on packaging of explosives. Two papers have been abstracted separately.

1992-01-01

388

Effect of the size of an artificial neural network used as pattern identifier  

Energy Technology Data Exchange (ETDEWEB)

A novel way to extract relevant parameters associated with the outgoing ions from nuclear reactions, obtained by digitizing the signals provided by a Bragg curve spectrometer (BCS) is presented. This allowed the implementation of a more thorough pulse-shape analysis. Due to the complexity of this task, it was required to take advantage of new and more powerful computational paradigms. This was fulfilled using a back-propagation artificial neural network (ANN) as a pattern identifier. Over training of ANNs is a common problem during the training stage. In the performance of the ANN there is a compromise between its size and the size of the training set. Here, this effect will be illustrated in relation to the problem of Bragg Curve (BC) identification. (Author)

2003-07-01

389

Dual-energy projection radiography using condenser discharge x-ray generator and FCR. Determination of technical factors  

Energy Technology Data Exchange (ETDEWEB)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique.

1987-04-01

390

Dual-energy projection radiography using condenser discharge x-ray generator and FCR  

International Nuclear Information System (INIS)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique. (author).

1987-01-01

391

Database management system for instrument data management  

Energy Technology Data Exchange (ETDEWEB)

Data from many measuring devices throughout the Savannah River Site (SRS) is transmitted to a central location for processing as a vital component in the SRS emergency preparedness and response program. The data processing is currently accomplished using VAX-based FORTRAN programs with the data stored in Digital's Record Management System (RMS) files which is shared using global COMMON. A program is underway to store and process this data using a Structured Query Language (SQL)-based Database Management System (DBMS). The advantages of replacing the current system with one using an SQL-based DBMS are discussed.

1990-01-01

392

Connectivity in the Astronomy Digital Library  

CERN Document Server

The Astrophysics Data System (ADS) provides an extensive system of links between the literature and other on-line information. Recently, the journals of the American Astronomical Society (AAS) and a group of NASA data centers have collaborated to provide more links between on-line data obtained by space missions and the on-line journals. Authors can now specify which data sets they have used in their article. This information is used by the participants to provide the links between the literature and the data. The ADS is available at: http://ads.harvard.edu

2006-01-01

393

Conformal radiation therapy: technical requirements and clinical applications  

International Nuclear Information System (INIS)

Conformal radiation therapy represents a considerable and attractive challenge in oncology. Its aim is mainly to improve local control by increasing the dose with an acceptable rate of complications. This work overviews the world literature on this subject. The technical and theoretical requirements are highlighted. These requirements include a precise definition of the target volume by digital imaging (essentially CT scan), but also clear view of the target volume and the organs at risk, a specific collimation of the beam, 3-D dose calculations, optimization procedures, and a rigid immobilization of the patient with verification of his position. Moreover, the clinical applications of conformal radiation therapy are reviewed and discussed. (authors). 80 refs., 1 tab.

1995-01-01

394

Beam position monitor readout and control in the SLC linac  

Energy Technology Data Exchange (ETDEWEB)

A beam position monitoring system has been implemented in the first third of the SLC linac which provides a complete scan of the trajectory on a single beam pulse. The data is collected from the local micro-computers and viewed with an updating display at a console or passed on to application programs. The system must operate with interlaced beams so the scans are also interlaced, providing each user with the ability to select the beam, the update rate, and the attenuation level in the digitizing hardware. In addition each user calibrates the hardware for his beam. A description of the system architecture will be presented. 6 refs., 4 figs.

1985-04-01

395

BUBL LINK Catalogue of Internet Resources  

Wastenet

...O | P | Q | R | S | T | U | V | W | X | Y | Z 230 Christianity: general resources ...com: Christianity: General Anno Domini: Jesus Through the Centuries Bible and Homosexuality Christian Theological Research Fellowship Papers Christianity Links and Resources Directory ...Good Digital Collections Lambert's Web Links MUNDUS New Testament Gateway Omnilist of Christian Starting Points Quartz Hill School of Theology Web Library Theology Online ...com: Christianity: General Offers original articles and features about Christianity in general plus annotated links to selected relevant Internet resources, compiled by ...

396

A driving system for Moessbauer spectrometer  

International Nuclear Information System (INIS)

The driving system of a Moessbauer spectrometer is described. The system comprises a minivibrator, a digital generator of the reference velocity signal, and circuits for controlling the vibrator. The reference velocity signal is stored by the control computer in an intermediate storage. The feedback in the control circuits includes correction for nonlinearity of the driving facility. A Moessbauer spectrometer which is equipped with this driving system exhibits a velocity scale nonlinearity below 0.1%. The resonance line width for sodium nitroprusside is 0.27 #+-# 0.01 mm/s. (author). 6 figs., 8 refs.

397

A PDA-Based ECG Beat Detector for Home Cardiac Care.  

Science.gov (United States)

Recent rapid growth in mobile computing technologies enables telemedicine applications to operate on mobile devices. Our focus is on the design of an integrated electrocardiogram (ECG) beat detector on a Personal Digital Assistant (PDA) platform for the health screening process. The ECG beat detector module will be supported by the PDA version of Personal Health Information Management System (PHIMS) and Facilitated Accurate Referral Management System (FARMS) through wireless network infrastructure as a home-based mobile cardiac monitoring solution. PMID:17282192

2005-01-01

398

A 40 GByte/s read-out system for GEM  

Energy Technology Data Exchange (ETDEWEB)

The preliminary design of the read-out system for the GEM (Gammas, Electrons, Muons) detector at the Superconducting Super Collider is presented. The system reads all digitized data from the detector data sources at a Level 1 trigger rate of up to 100 kHz. A total read-out bandwidth of 40 GBytes/s is available. Data are stored in buffers that are accessible for further event filtering by an on-line, processor farm. Data are transported to the farm only as they are needed by the higher-level trigger algorithms, leading to a reduced bandwidth requirement in the Data Acquisition System.

1994-04-01

399

Digital direct magnification mammography with storage phosphor screens. Standardized and image result dependent post-processing parameters; Digitale Vergroesserungsmammographie mit Speicher-Folien-Technik. Standardisierte und befundorientierte Bildverarbeitungsparameter  

Energy Technology Data Exchange (ETDEWEB)

Present day mammography has not been able to make use of the advantages of digital luminescence radiography because of the limited spatial resolution. The recent development of electromagnetic focusing X-ray tube with effective focal spot sizes from 0.04 to 0.12 mm allows radiographic direct magnification with less geometric blur. It is now possible to combine direct magnification mammography with digital luminescence radiography. By combining high quality storage phosphor screens with an HQ-workstation a spatial resolution of 8 lp/mm is possible for 1.7-fold magnification. For 4-fold spot magnification views spatial resolution can be theoretically increased to approx. 20 lp/mm. One important advantage of digital radiography is the possibility of image-postprocessing. This article presents two sets of standard parameters and three sets of image dependent parameters for better imaging of specific lesions, such as ...

1997-05-01

400

Terra Nova: taming the North Atlantic  

Energy Technology Data Exchange (ETDEWEB)

The Terra Nova offshore oil project is described, with emphasis on the construction of the Terra Nova Floating Production Storage and Offloading (FPSO) vessel, the first such vessel constructed for the harsh environment of the North Atlantic off Newfoundland, the site of an oil field that is expected to produce 125,000 to 150,000 barrels of oil per day starting in 2001. The vessel has a double-hull, made of 3,000 tons of reinforced steel to protect it from ice in the form of massive icebergs or crusty 'packs'. The vessel has the world's largest quick release turret, meaning that the vessel can be quickly disconnected from its turret and mooring in the event of an encroaching iceberg, and then reconnected in an environmentally sound way. Apart from its extremely rugged construction, protecting the FPSO vessel against icebergs is accomplished by way of 'hosing down' (by melting by powerful streams of water) or 'lassoing' (by ...

2000-08-01

401

Groundwater flow analysis and dose rate estimates from releases to wells at a coastal site  

Energy Technology Data Exchange (ETDEWEB)

In the groundwater flow modelling part of this work the effective dilution volume in the well scenario was estimated by means of transient simulations of groundwater flow and transport, which are coupled due to the varying salinity. Both deep, drilled wells and shallow surface wells in the vicinity of the repository were considered. The simulations covered the time period from the present to 1000 years after the present. Conceptually the fractured bedrock consists of planar fracture zones (with a high fracture density and a greater ability to conduct water) and the intact rock (in which the fracture density and the hydraulic conductivity are low). For them the equivalent-continuum model was applied separately. Thus, the fractured bedrock was considered as piecewise homogeneous (except for the depth dependence) and isotropic continuum with representative average characteristics. A generic simulation model for groundwater flow and solute transport was developed on the basis of ...

2000-09-01

402

Further development of the unified multiscale Eulerian model for a broad range of spatial and temporal scales within the new National Environmental Modeling System  

Science.gov (United States)

A unified Nonhydrostatic Multiscale Model on the Arakawa B grid (NMMB) designed for a broad range of spatial and temporal scales has been under development within the Earth System Modeling Framework (ESMF) at the National Centers for Environmental Prediction (NCEP) as a part of the new National Environmental Modeling System (NEMS). The model follows the general modeling philosophy of the NCEP's WRF NMM grid-point regional dynamical core. The model uses the regular latitude-longitude grid for the global domain, and a rotated latitude-longitude grid in regional applications. The nonhydrostatic component of the model dynamics is introduced through an add-on module that can be turned on or off depending on resolution. The "isotropic" quadratic conservative finite-volume horizontal differencing employed in the model conserves a variety of basic and derived dynamical and quadratic quantities and preserves some important properties of differential operators. Among these, the conservation of ...

2009-04-01

403

DoseWatchers - A computer based X ray dose monitoring project in paediatric radiology  

International Nuclear Information System (INIS)

Full text: Introduction. Children, especially premature infants and neonates, are at a much higher risk to obtain an X ray induced disturbance of life - particularly cancer. On the one hand this is due to their longer life expectancy and on the other hand it is due to their higher cell proliferation rate. The paediatric radiology unit of the Inselspital Bern recently installed some of the most advanced X ray equipment nowadays available. It is based on the two latest digital technologies: double read computed radiography (CR) and direct digital radiography (DR). Only the implementation of these digital radiography systems permits the digital acquisition and additionally the analysis of acquired data. The systematic analysis of large amounts of biometric data and exposition data is the basis for further dose reduction and a systematic quality control (QC). Patients are increasingly critical concerning ...

2006-11-13

404

Zone mapping application for precision-farming: a decision support tool for variable rate application  

British Library Electronic Table of Contents (United Kingdom)

A web-based decision support tool, zone mapping application for precision farming (ZoneMAP, External Reference Not Shown ), has been developed to automatically determine the optimal number of management zones and delineate them using satellite imagery and field data provided by users. Application rates, such as of fertilizer, can be prescribed for each zone and downloaded in a variety of formats to ensure compatibility with GPS-enabled farming equipment. ZoneMAP is linked to Digital Northern Great Plains, a web-based application which hosts an archive of satellite imagery, as well as high resolution imagery from airborne sensors. Management zones created by ZoneMAP mapped natural variation of the soil organic matter and other nutrients relatively well and were consistent with zone maps cre...

2010-01-01

405

X-ray imaging dose due to the digital imaging devices used in radiation therapy for patient positioning and repositioning: How to take it into account?; Les doses dues a l'imagerie numerique pour le controle de positionnement du patient en radiotherapie: comment les prendre en compte?  

Energy Technology Data Exchange (ETDEWEB)

The patient positioning and repositioning control in radiation therapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiation therapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiation therapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiation therapy treatment. (authors)

2008-12-15

406

Ventilation as a means of air-conditioning power saving in reinforced concrete telephone-exchange buildings analysis and directions for design  

Energy Technology Data Exchange (ETDEWEB)

The paper presents a computer-aided analysis of the combined use of ventilation and structural heat capacity and insulation as a means of saving air-conditioning power in digital telephone exchanges. It is shown that such savings can be effected by increasing air change with outdoor cool air at night, and when feasible, also in daytime, through the air change unit, in a conventional airconditioning cycle. The total thermal time constant (TTTC) method of calculation used enables the evaluation of daily or seasonal heat-flow balance for a given indoor temperature, considering the tendency of the heat capacity of the building and of envelope components to flatten the fluctuations of this temperature.

1984-12-01

407

Using topographic wetness index in vegetation ecology: does the algorithm matter?  

British Library Electronic Table of Contents (United Kingdom)

Abstract Questions: How important is the choice of flow routing algorithm with respect to application of topographic wetness index (TWI) in vegetation ecology? Which flow routing algorithms are preferable for application in vegetation ecology? Location: Forests in three different regions of the Czech Republic. Methods: We used vegetation data from 521 georeferenced plots, recently sampled in a wide range of forest communities. From a digital elevation model, we calculated 11 variations of TWI for each plot with 11 different flow routing algorithms. We evaluated the performance of differently calculated TWI by (1) Spearman rank correlation with average Ellenberg indicator values for soil moisture, (2) Mantel correlation coefficient between dissimilarities of species composition and dissimil...

2010-01-01

408

Training and information technology issue, 2005  

Science.gov (United States)

The focus of the May-June issue is on training and information technology. Major articles/reports in this issue include: Communicating effectively, by Alain Bucaille, AREVA; Reputation management, by Susan Brisset, Bruce Power; Contol room and HSI modernization guidance, by Joseph Naser, EPRI; How far are we from public acceptance, by Jennifer A. Biedscheid and Murthy Devarakonda, Washington TRU Solutions LLC; Spent fuel management options, by Brent W. Dixon and Steven J. Piet, Idaho National Laboratory; Industry Awards; A secure energy future for America, by George W. Bush, President, United States of America; Vision of the future of nuclear energy, by Anne Lauvergeon, AREVA; and, Plant profile: strategy for transition to digital, TXU Power.

2005-05-15

409

The segmental gastrocnemius muscles' flap: A cadaveric study  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to evaluate the feasibility of splitting each head of the gastrocnemius muscle into two segments. This prospective study was conducted on 35 fresh cadavers with injection of radio-opaque contrast material in the popliteal artery. Seventy medial gastrocnemius and 70 lateral gastrocnemius muscle specimens were obtained. Gastrocnemius intramuscular arterial anatomy was analysed by using the digital X-ray technique. The most common vascular pattern found in this study was both bellies supplied by individual sural arteries, which shows distal bifurcation. The medial sural artery always showed bifurcation in the medial gastrocnemius muscle in both lower limbs, whereas this bifurcation of the lateral sural artery was present in only 87% cases and 13% of cases showed a si...

2011-01-01

410

The response of small scale rigid targets to shallow buried explosive detonations  

British Library Electronic Table of Contents (United Kingdom)

Experimental and computational investigations were performed in order to better understand the mechanical response of rigid targets with various geometries to the detonation of shallow buried explosives. The motion of the targets was measured by use of high-speed digital video photography. This work involved flat targets, targets that were downwardly convex, and targets that were downwardly concave with explosive charges located at various positions beneath the targets. It was observed that, in general, angled hulls - whether downwardly concave or convex - tended to reduce the amount of momentum imparted to the center of mass of the targets. Computations were performed by use of an arbitrary Langrangian-Eulerian treatment in a nonlinear finite element code. A model based on quasi-static te...

2011-01-01

411

The RooStats Project  

CERN Document Server

RooStats is a project to create advanced statistical tools required for the analysis of LHC data, with emphasis on discoveries, confidence intervals, and combined measurements. The idea is to provide the major statistical techniques as a set of C++ classes with coherent interfaces, which can be used on arbitrary model and datasets in a common way. The classes are built on top of RooFit, which provides a very convenient functionality for modeling the probability density functions or the likelihood functions, required as inputs for any statistical technique. Furthermore, RooFit provides the functionality for easily creating models, for analysis combination and for digital publication of the likelihood function and the data. We will present in detail the design and the implementation of the different statistical methods of RooStats. These include various classes for interval estimation and for hypothesis test depending on different statistical techniques such as those ...

2010-01-01

412

The Lithium future-resources, recycling, and the environment  

British Library Electronic Table of Contents (United Kingdom)

Abstract:- The demand for Lithium-ion batteries as a major power source in portable electronic devices and vehicles is rapidly increasing. I use cumulative data of vehicle, mobile phone, laptop, and digital camera production to show that demand will overshoot the available global Lithium resources before 2025. Even if 100% of all Lithium-ion batteries were recycled today, recycling could not prevent this resource depletion in time. As the increasing Lithium scarcity will increase the price, it will be feasible to mine diluted resources with a strong environmental impact. I highlight these impacts in Lithium-rich Bolivia, the potential new -Saudi Arabia of Lithium.- Lithium extraction is likely to cause substantial water pollution, and-through impacts on native diversity-facilitate human he...

2011-01-01

413

Temperature problems in mine rescue  

Energy Technology Data Exchange (ETDEWEB)

Describes temperature and humidity sensing devices used in mine rescue operations. Chemical indicators use chemical substances that melt at predetermined temperatures and display the actual temperature in the range of 40-50 C. Electronic temperature monitoring devices release acoustic signals as soon as a temperature of 40 or 45 C has been exceeded. A more recent piece of equipment combines the ULR rescue communication set with remote temperature sensing. A digital meter that measures temperature and humidity in the range of -100 to +200 C and 3 to 98% respectively has also been developed. The Central Mine Rescue Station in Bytom, Poland has developed equipment that permits body temperature and pulse rate of a rescuer to be measured and transmitted by radio over a distance of up to 50 m. Safe threshold values can be set for each individual rescuer.

1990-08-01

414

Surface characteristics and overlaying properties of flat-pressed wood plastic composites  

British Library Electronic Table of Contents (United Kingdom)

This study evaluated surface characteristics and overlaying properties of wood plastic composite (WPC) panels made from dry-blended rubber wood fiber-polypropylene (PP) powder formulations using a conventional flat-press process under laboratory conditions. Three levels of rubberwood fibers (Hevea brasiliensis), 40%, 50%, and 60%, based on the composition by weight, were mixed with the PP powder without and with 3% (based on weight) maleic anhydride grafted PP (MAPP) as a coupling agent. Contact angle measurements on the WPC samples were performed using a goniometer connected with a digital camera which collected one image per second. Roughness measurements, average roughness (R a), mean peak-to-valley height (R z), and maximum roughness (R y), were taken from the sanded samples along and ...

2011-01-01

415

Studies on ball screw type damper with centrifugal brakes  

International Nuclear Information System (INIS)

The effects of vibration isolation of the new type of mechanical damper applied to a single-degree-of-freedom system and a simple beam are discussed numerically and experimentally. The damper is composed of a ball screw, a flywheel and centrifugal brakes, and possesses nonlinear characteristics. The Continuous System Simulation Language is used for the digital simulations of the nonlinear vibration systems. The results may be summarized as follows: (1) The damper is effective for suppressing the amplitude of the single-degree-of-freedom system as well as of the beam at the point of attachment of the damper, at the resonances. (2) The damper approaches a snubber for smaller values of lead L of the ball screw (or larger values of moment of inertia J of the flywheel), and acts like a damper whose damping force is proportional to the square of the velocity for larger values of L (or smaller values of J). (author).

1986-01-01

416

State-of-the-Art developments in accelerator controls at the APS.  

Energy Technology Data Exchange (ETDEWEB)

The performance requirements of the Advanced Photon Source (APS) challenge the control system in a number of areas. This paper will review a few applications of advanced technology in the control and monitoring of the APS. The application of digital signal processors (DSPs) and techniques will be discussed, both from the perspective of a large distributed multiprocessor system and from that of embedded systems. In particular, two embedded applications will be highlighted, a beam position monitor processor and a DSP-based power supply controller. Fast data distribution is often a requirement. The application of a high-speed network based on reflective memory will also be discussed in the context of the APS global orbit feedback system. Timing systems provide opportunities to apply technologies such as high-speed logic and fiber optics. Examples of the use of these technologies will also be included. Finally, every modern accelerator control system of any size ...

1999-04-13

417

Spray, combustion, and heat transfer studies in a Ricardo hydra direct-injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

The spray and combustion development in a single-cylinder, direct-injection diesel engine equipped with optical access was examined using a number of complementary techniques. A laser imaging system, based around a pulsed copper-vapour laser synchronised to an intensified CCD camera, was used to obtain images of the four fuel sprays prior to combustion, and to determine the tip penetration of each spray as a function of crankangle. The surface heat flux to the wall of the piston bowl was measured by placing a fast-response thermocouple at the impingement point of one of the sprays, and a two-colour imaging system was used to obtain digital images of the flame temperature and equivalent soot distribution in the cylinder. (author)

1996-12-31

418

Single-pole switching schemes for EHV transmission systems  

Energy Technology Data Exchange (ETDEWEB)

Recognizing that a high percentage of transmission-line faults are single-phase to earth and temporary in nature, provides the impetus for considering single-pole switching as a means to enhance the reliability of EHV transmission systems. The effectiveness of single-pole switching schemes is largely determined by the speed with which the secondary arcs extinguish, and hence allow system restoration. Simulation techniques that enable better prediction of the faulted-system response are of obvious importance to the design and assessment of the various single-pole switching scheme applications. In this thesis, digital methods are developed to enable the faulted response of EHV systems to be simulated for a variety of different single-pole switching schemes. These include conventional single-pole switching, the hybrid method of autoreclosure, the neutral switched reactor, and the High Speed Grounding Switch implementations. The work is of importance to system ...

1986-01-01

419

Simulation study of feedback systems based on a two-tap FIR filter. Under beam-beam collisions  

Energy Technology Data Exchange (ETDEWEB)

The performance of bunch-feedback systems based on two-tap FIR filters is discussed, particularly for transverse cases. Since they are the simplest type of FIR digital filters, the two-tap FIR filters should be suited to systems that require a very fast processing speed. However, in these feedback systems, a bunch must turn along a ring several times from the position-measurement to feedback kicking. Within these turns, irregular phase-jumps in the betatron motion can occur, due to several causes, such as the wake forces and beam-beam force. The discussion given in this paper is focussed on the effect of beam-beam collisions on these feedback systems. Based on linear theory and simulation studies, it has been found that these feedback systems can work with good performance, even under the influence of a strong beam-beam force. (author)

1998-04-01

420

Security of mobile agents: a new concept of the integrity protection  

CERN Document Server

The recent developments in the mobile technology (mobile phones, middleware) created a need for new methods of protecting the code transmitted through the network. The proposed mechanisms not only secure the compiled program, but also the data, that can be gathered during its "journey". The oldest and the simplest methods are more concentrated on integrity of the code itself and on the detection of unauthorized manipulation. Other, more advanced proposals protect not only the code but also the execution state and the collected data. The paper is divided into two parts. The first one is mostly devoted to different methods of securing the code and protecting its integrity; starting from watermarking and fingerprinting, up to methods designed specially for mobile agent systems: encrypted function, cryptographic traces, time limited black-box security, chained-MAC protocol, publicly-verifiable chained digital signatures The second part presents new concept for ...

2005-01-01

421

Resonant overvoltage phenomena caused by transmission line faults  

Energy Technology Data Exchange (ETDEWEB)

Resonant overvoltages in EHV transformers can be initiated by transmission line faults. A series of field tests were performed on the 151 mile long Kammer-Marysville 765 kV line in which a sequence of single line to ground faults were applied to one outside phase at 4 different locations. Fault location criteria and fault initiation procedures are presented. Oscillograms recorded the 3 phase response at both terminals of the line; one is transformer terminated, the other is open-ended. A frequency spectrum analysis of the waveforms is provided showing transient frequencies of sufficient magnitude and duration near the EHV transformer's resonant frequency to stimulate internal winding resonant overvoltages. Digital computer studies are presented and agree with the field tests quite favorably.

1985-09-01

422

Reinforced concrete beam-column joint strengthened with carbon fiber reinforced polymer  

British Library Electronic Table of Contents (United Kingdom)

An effective rehabilitation strategy is proposed to enhance the strength and stiffness of the beam-column joint in this study. An analytical model is proposed to predict the column shear of the joints strengthened with carbon fiber reinforced polymer (CFRP). Three full scale interior beam-column joints, including two specimens strengthened with CFRP and one prototype specimen, are tested in this study. The specimens are designed to represent the pre-seismic code design construction in which there is no transverse reinforcement. A new optical non-contact technique, digital image correlation (DIC), which can measure the full strain field of specimen, is used to measure and observe the full strain field of the joint. The experimental results show that the beam-column joints strengthened with ...

2010-01-01

423

Real-time orbit feedback at the APS.  

Energy Technology Data Exchange (ETDEWEB)

A real-time orbit feedback system has been implemented at the Advanced Photon Source in order to meet the stringent orbit stability requirements. The system reduces global orbit motion below 30Hz by a factor of four to below 5{micro}m rms horizontally and 2{micro}m rms vertically. This paper focuses on dynamic orbit stability and describes the all-digital orbit feedback system that has been implemented at the APS. Implementation of the global orbit feedback system is described and its latest performance is presented. Ultimately, the system will provide local feedback at each x-ray source point using installed photon BPMs to measure x-ray beam position and angle directly. Technical challenges associated with local feedback and with dynamics of the associated corrector magnets are described. The unique diagnostic capabilities provided by the APS system are discussed with reference to their use in identifying sources of the underlying orbit motion.

1998-06-18

424

Real-time neutron radiography for visualisation of interfacial geometry and phase distribution in two-phase flow  

International Nuclear Information System (INIS)

Results of ongoing research project at the McMaster Nuclear Reactor Facility on real-time neutron radiography for the visualization of interfacial geometry, movements and phase distributions in gas-liquid and gas-liquid-metal multi-phase flows are presented. Experiments were conducted with bubble column tubes with boiling liquid nitrogen, air-water and air-mercury mixtures. Discussions are also focused on air-water flowing within a tube containing a CANDU type 37 rod fuel bundle assembly positioned both horizontally and vertically. Computer processing using a digital image format to enhance the real-time images was used. Imaging techniques include frame averaging, background substraction, edge enhancement (spatial filtering), contrast enhancement and video densitometry. (orig.).

1989-10-01

425

Rapid and precise measurement of flatband voltage  

Science.gov (United States)

The paper outlines the design, principles of operation, and calibration of a five-IC network intended to give a rapid, precise, and automatic determination of the flatband voltage of MOS capacitors. The basic principle of measurement is to compare the analog output voltage of a capacitance meter - which is directly proportional to the capacitance being measured - with a preset or dialed-in voltage proportional to the calculated flatband capacitance by means of a comparator circuit. The bias to the MOS capacitor supplied through the capacitance meter is provided by a ramp voltage going from a negative toward a positive voltage level and vice versa. The network employs two monostable multivibrators for reading and recording the flatband voltage and for resetting the initial conditions and restarting the ramp. The flatband voltage can be held and read on a digital voltmeter.

1976-05-01

426

Quantifying bank erosion on the South River from 1937 to 2005, and its importance in assessing Hg contamination  

British Library Electronic Table of Contents (United Kingdom)

Bank sediments along a 40km reach of the South River, downstream of Waynesboro, VA, store mercury from historical contamination as a result of textile manufacturing. Knowledge of the rate at which contaminated sediment is released to the stream channel through bank erosion is required to implement restoration programs designed, for example, to minimize its ecological impact and to reduce risk to human health. Digitized stream channel boundaries based on visual interpretations of georeferenced aerial imagery from 1937 and 2005 were compared to calculate a minimum estimate of the total area of bank sediment eroded between Waynesboro and Port Republic, Virginia. Estimates of riverbank height were extracted from aerial LIDAR data, allowing areal estimates of bank retreat to be converted to vol...

2009-01-01

427

Psychological test performance in foundry workers exposed to low levels of manganese  

Energy Technology Data Exchange (ETDEWEB)

A sample of 30 manganese-exposed foundry workers from two Swedish plants were examined with a partly computerized psychological test battery, comprised of 10 performance tests. Performance of the manganese-exposed workers was compared to that of a matched control group of 60 workers. Matching criteria were age, geographical area, type of work, and the results on a test of verbal comprehension. Performance of the exposed workers was inferior to that of the control group on tests of simple reaction time, digit span, and finger tapping. No correlations were found between performance and the present manganese exposure levels or the number of years employed in manganese work. The results seem to indicate that the present exposure standards for manganese, in Sweden 2.5 mg/m3 and in most other countries 5 mg/m3, are not sufficient to protect workers from negative effects on performance capacity.

1990-11-01

428

Project of the new measurement system for energy invoicing - Itaipu Hydroelectric Central; Proyecto del nuevo sistema de medicion de energia para facturacion de la Central Hidroelectrica de Itaipu  

Energy Technology Data Exchange (ETDEWEB)

Itaipu Binacional has taken a decision of executing a technological updating for the energy measurement system through the substitution of the current system by other one equipped with digital devices. The main reasons for that were the following: a) The equipment in operation were of an outdated generation b) The accuracy class of the existing equipment was of 0.5%, but the tendency for invoicing measurements was to install meters with accuracy class of 0.2% in the enterprises c) The requirements of ONS/MAE, in Brazil, which establishes the minimum requisites to be attended by invoicing measurement systems.

2001-07-01

429

Non-linearity and hysteresis of Hall effect in magnetorheological suspensions with conducting carrier  

Energy Technology Data Exchange (ETDEWEB)

In this article a production method of a magnetorheological suspension composed with silicon steel particles of size 0.1-0.15 mm and 4% silicon content is described. Steel particles were dispersed in a conducting carrier of a by mixture of graphite particles with size 2-5 {mu}m and cedar wood oil. The filling factor of the suspension with the silicon steel particles and with graphite particles amounted to 0.25-0.40. Samples of this suspension were placed in a rectangular vessel with electrodes and used for the investigation of the Hall effect in magnetic field with induction 0-8 T, generated by Bitter-type magnet. A non-linear dependence of Hall voltage on the induction of the applied magnetic field and a hysteresis loop of this voltage in the shape of inclined digit eight were found. The causes of the observed effects is the ordering of silicon steel particles and graphite particles along the side of magnetic field lines.

2003-08-01

430

Neutron radiography with the cyclotron, 5. Cyclotron-based real time neutron fluoroscopy system and its application for some industrial components  

Energy Technology Data Exchange (ETDEWEB)

Reliable facility of cyclotron-based real time neutron radiography system has been developed and applied to some industrial components. The equipment for neutron fluoroscopy is based on a sub-compact cyclotron and a LiF/ZnS (Ag) fluorescent screen viewed by a silicon intensifier target TV camera. The real time image is monitored on a CRT, recorded with a standard video recorder and processed by a digital image processor. The effectiveness of our real time neutron radiograph has been demonstrated to be applicable to not only the dynamic observation but also the magnifying and stereoscopic observation of fluoroscopic images.

1987-03-01

431

Mining Knowledge in Astrophysical Massive Data Sets  

CERN Document Server

Modern scientific data mainly consist of huge datasets gathered by a very large number of techniques and stored in very diversified and often incompatible data repositories. More in general, in the e-science environment, it is considered as a critical and urgent requirement to integrate services across distributed, heterogeneous, dynamic "virtual organizations" formed by different resources within a single enterprise. In the last decade, Astronomy has become an immensely data rich field due to the evolution of detectors (plates to digital to mosaics), telescopes and space instruments. The Virtual Observatory approach consists into the federation under common standards of all astronomical archives available worldwide, as well as data analysis, data mining and data exploration applications. The main drive behind such effort being that once the infrastructure will be completed, it will allow a new type of multi-wavelength, multi-epoch science which can only be barely ...

2010-01-01

432

Method for the reduction of image content redundancy in large image databases  

Energy Technology Data Exchange (ETDEWEB)

A method of increasing information content for content-based image retrieval (CBIR) systems includes the steps of providing a CBIR database, the database having an index for a plurality of stored digital images using a plurality of feature vectors, the feature vectors corresponding to distinct descriptive characteristics of the images. A visual similarity parameter value is calculated based on a degree of visual similarity between features vectors of an incoming image being considered for entry into the database and feature vectors associated with a most similar of the stored images. Based on said visual similarity parameter value it is determined whether to store or how long to store the feature vectors associated with the incoming image in the database.

2010-03-02

433

Mapping soil organic matter using the topographic wetness index: A comparative study based on different flow-direction algorithms and kriging methods  

British Library Electronic Table of Contents (United Kingdom)

Terrain attributes derived from digital elevation models have been used widely for mapping soil organic matter (SOM). Among these attributes, the topographic wetness index (TWI), an index for quantitatively indicating the balance between water accumulation and drainage conditions at the local scale, has been shown to correlate with SOM. However, TWIs used in most studies are calculated using a single-flow-direction (SFD) algorithm, which assumes that all water from a grid cell flows into only one neighboring cell. This assumption is not always valid, especially in areas with low relief where movement of water may be divergent. To overcome this SFD limitation, a multiple-flow-direction (MFD) algorithm has been developed, which distributes flow from a grid cell to several downslope neighbors...

2010-01-01

434

Liquid metal flow measurement by neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

Visualization of a liquid metal flow and image processing methods to measure the vector field are carried out by real-time neutron radiography. The JRR-3M real-time thermal neutron radiography facility in the Japan Atomic Energy Research Institute was used. Lead-bismuth eutectic was used as a working fluid. Particles made from a gold-cadmium intermetallic compound (AuCd{sub 3}) were used as the tracer for the visualization. The flow vector field was obtained by image processing methods. It was shown that the liquid metal flow vector field was obtainable by real-time neutron radiography when the attenuation of neutron rays due to the liquid metal was less than l/e and the particle size of the tracer was larger than one image element size digitized for the image processing. (orig.).

1996-07-21

435

Liquid metal flow measurement by neutron radiography  

International Nuclear Information System (INIS)

Visualization of a liquid metal flow and image processing methods to measure the vector field are carried out by real-time neutron radiography. The JRR-3M real-time thermal neutron radiography facility in the Japan Atomic Energy Research Institute was used. Lead-bismuth eutectic was used as a working fluid. Particles made from a gold-cadmium intermetallic compound (AuCd_3) were used as the tracer for the visualization. The flow vector field was obtained by image processing methods. It was shown that the liquid metal flow vector field was obtainable by real-time neutron radiography when the attenuation of neutron rays due to the liquid metal was less than l/e and the particle size of the tracer was larger than one image element size digitized for the image processing. (orig.).

1996-07-01

436

Land use change in a biofuels hotspot: The case of Iowa, USA  

British Library Electronic Table of Contents (United Kingdom)

This study looks at the land use impact of the biofuels expansion on both the intensive and extensive margin, and its environmental consequences. We link economic, geographical and environmental models by using spatially explicit common units of analysis and use remote sensing crop cover maps and digitized soils data as inputs. Land use changes are predicted via economic analysis of crop rotation choice and tillage under alternative crop prices, and the Environmental Policy Integrated Climate (EPIC) model is used to predict corresponding environmental impacts. The study focuses on Iowa, which is the leading biofuels hotspot in the U.S. due to intensive corn production and the high concentration of ethanol plants that comprise 28% of total U.S. production. We consider the impact of the biof...

2011-01-01

437

Kinetics of gypsum crystal growth on a reverse osmosis membrane  

British Library Electronic Table of Contents (United Kingdom)

The development of calcium sulfate dihydrate (gypsum) mineral scale in reverse osmosis (RO) membrane desalting was investigated by direct real-time observation of crystal growth. Gypsum scaling studies were conducted in a specially modified plate-and-frame reverse osmosis cell fitted with an optical window, with dark-field membrane lighting arrangement within the membrane cell to enhance crystal boundaries and allow recording of digital surface images magnified through an optical microscope. The evolution of the surface number density (SND) of gypsum crystals resembled a sigmoidal population growth process with an increasing rate of crystal formation at higher solution supersaturation (with respect to gypsum) at the membrane surface. The rate of formation of new crystals declined as the su...

2008-01-01

438

Implementation of an OFDM underwater acoustic communication system on an underwater vehicle with multiprocessor structure  

British Library Electronic Table of Contents (United Kingdom)

Orthogonal frequency division multiplexing (OFDM) can fully use the frequency band and transmit data at high speeds. The ADSP-TS101 is a high performance digital signal processor (DSP) with good properties that include parallel processing and a high speed. Aimed at the real-time processing requirement of the OFDM algorithm, an underwater acoustic communication system with real-time processing capability is carried out. The system is mainly composed of multiple ADSP-TS101s, a multi-channel synchronous sample module and a field programmable gate array (FPGA) chip. The multiprocessor structure is made up of a cluster/data flow associated multiprocessing parallel processing structure as the operation kernel, and a multi-channel synchronous sample module is designed to realize no phase warp amo...

2007-01-01

439

Idealized gas turbine combustor for performance research and validation of large eddy simulations.  

Science.gov (United States)

This paper details the design of a premixed, swirl-stabilized combustor that was designed and built for the express purpose of obtaining validation-quality data for the development of large eddy simulations (LES) of gas turbine combustors. The combustor features nonambiguous boundary conditions, a geometrically simple design that retains the essential fluid dynamics and thermochemical processes that occur in actual gas turbine combustors, and unrestrictive access for laser and optical diagnostic measurements. After discussing the design detail, a preliminary investigation of the performance and operating envelope of the combustor is presented. With the combustor operating on premixed methane/air, both the equivalence ratio and the inlet velocity were systematically varied and the flame structure was recorded via digital photography. Interesting lean flame blowout and resonance characteristics were observed. In addition, the combustor exhibited a large region of ...

2007-03-01

440

GPS and Google Earth based 3D assisted driving system for trucks in surface mines  

British Library Electronic Table of Contents (United Kingdom)

In order to reduce the number of surface mining accidents related to low visibility conditions and blind spots of trucks and to provide 3D information for truck drivers and real time monitored truck information for the remote dispatcher, a 3D assisted driving system (3D-ADS) based on the GPS, mesh-wireless networks and the Google-Earth engine as the graphic interface and mine-mapping server, was developed at Virginia Tech. The research results indicate that this 3D-ADS system has the potential to increase reliability and reduce uncertainty in open pit mining operations by customizing the local 3D digital mining map, constructing 3D truck models, tracking vehicles in real time using a 3D interface and indicating available escape routes for driver safety.

2010-01-01

441

Focused ion beam sculpting curved shapes.  

Energy Technology Data Exchange (ETDEWEB)

A focused ion beam (FIB) is used to accurately sculpt predetermined micron-scale, curved shapes in a number of solids. Using a digitally scanned ion beam system, various features are sputtered including hemispheres and sine waves having dimensions from 1-50 {micro}m. Ion sculpting is accomplished by changing pixel dwell time within individual boustrophedonic scans. The pixel dwell times used to sculpt a given shape are determined prior to milling and account for the material-specific, angle-dependent sputter yield, Y({theta}), as well as the amount of beam overlap in adjacent pixels. A number of target materials, including C, Au and Si, are accurately sculpted using this method. For several target materials, the curved feature shape closely matches the intended shape with milled feature depths within 5% of intended values.

2005-02-01

442

Focused ion beam preparation of inclined planes in semiconductor materials  

International Nuclear Information System (INIS)

Focused ion beam (FIB) micromachining has been used to produce inclined planes on semiconductor surfaces. A 10 keV FIB system, utilising a Ga"+ liquid metal ion source (LMIS), was employed. The ramped surfaces were prepared by digitally deflecting the ion beam in a serpentine fashion over a rectangular area and incrementing the time the beam spends at a pixel, dwell time, line by line. For the conditions used, control in micromachining the inclination of the ramps to the starting horizontal surface is of the order of 1 arc s per scan of the FIB over the area of interest. The possibility of using such surfaces prepared by FIB, along with vacuum growth techniques such as molecular beam epitaxy (MBE), for application to strain relief structures and lateral device production is discussed. (author).

443

Extracting mining subsidence land from remote sensing images based on domain knowledge  

Energy Technology Data Exchange (ETDEWEB)

Extracting mining subsidence land from remote sensing (RS) images is one of important research contents for environment monitoring in mining area. The accuracy of traditional extracting models based on spectral features is low. In order to extract subsidence land from RS images with high accuracy, some domain knowledge should be imported and new models should be proposed. This paper, in terms of the disadvantage of traditional extracting models, imports domain knowledge from practice and experience, converts semantic knowledge into digital information, and proposes a new model for the specific task. By selecting the Luan mining area as a study area, this new model is tested based on GIS and related knowledge. The result shows that the proposed method is more precise than traditional methods and can satisfy the demands of land subsidence monitoring in mining area. 10 refs., 4 figs., 1 tab.

2008-06-15

444

Extensions to the VME hardware and software standards for the physics community  

Energy Technology Data Exchange (ETDEWEB)

With the ubiquitous availability of commercial VME modules and interface chips many experiments in all branches of Experimental Physics are turning to VME as the module packaging and backplane protocol of choice for application specific modules. The current VME backplane, electrical, and mechanical standards are clearly lacking when it comes to implementing the analogue and digital front end modules that Physics experiments rely on to provide the needed high speed and intelligent solutions to their data collection requirements. To address these needs the European ESONE and American VME-P committees are collaborating with the ANSII and ISO standards committees, and the VME VITA/VSO manufacturers associations, to define standard extensions to the VME protocols for such HEP needs as ``sparse data scans``, standard uses and implementations of previously user defined pins and connectors, standardization of the 9U form factor VME cards etc. This paper reports on the ...

1995-10-01

445

Evaluation of routine telephone transmission of nuclear medicine studies  

Energy Technology Data Exchange (ETDEWEB)

Rapid and reliable transmission of nuclear medicine studies using conventional telephone lines and commercially available modems and computer systems has been accomplished through use of software developed within the authors' hospital. Original digital images of all-night and weekend studies, acquired on any of the acquisition computers from different manufacturers, are now routinely sent for remote reading at the physician's home. Data, software, and letters are routinely exchanged using modems and standard telephone lines with a sister institution in Haifa, Israel. The software has been designed to achieve no loss data compression and minimal turnaround time loss. Thus, an average lung perfusion image or gallbladder study requires about 1-3 minutes of transmission time. Full analysis and display software is available on the remote computer.

1989-01-01

446

Evaluation of digital radiography (Fuji computed radiography) for portable chest radiographs in ICU  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the usefulness of portable chest radiographs by Fuji computed radiography (FCR) in ICU, FCR radiographs of 56 patients who were admitted to General Intensive Care Unit of Keio University Hospital were compared with the conventional portable images. Because FCR could show two differently processed images in one film and allowed a wide range of image reproduction, visualization of the trachea, bone soft tissues and catheters by FCR was easier than that by the conventional radiography. Repeated radiographs by FCR had similar optical densities and limited exposure errors. Furthermore, radiation was reduced than that of the conventional radiography. In conclusion, FCR is thought to be a useful technique for portable chest radiography in ICU patients. (author).

1992-12-01

447

Evaluation of digital radiography (Fuji computed radiography) for portable chest radiographs in ICU  

International Nuclear Information System (INIS)

To evaluate the usefulness of portable chest radiographs by Fuji computed radiography (FCR) in ICU, FCR radiographs of 56 patients who were admitted to General Intensive Care Unit of Keio University Hospital were compared with the conventional portable images. Because FCR could show two differently processed images in one film and allowed a wide range of image reproduction, visualization of the trachea, bone soft tissues and catheters by FCR was easier than that by the conventional radiography. Repeated radiographs by FCR had similar optical densities and limited exposure errors. Furthermore, radiation was reduced than that of the conventional radiography. In conclusion, FCR is thought to be a useful technique for portable chest radiography in ICU patients. (author).

1992-01-01

448

Establishment and clonal spread of the alien shrub Rosa rugosa in coastal dunes-A method for reconstructing and predicting invasion patterns  

British Library Electronic Table of Contents (United Kingdom)

Little is known about the rates of establishment and clonal spread of invasive plants on a landscape scale. This knowledge is necessary for reconstructing and predicting invasions, for example of the alien shrub Rosa rugosa. A series of aerial photographs (1986, 1999, 2002, 2004, 2006) were used to map the species in coastal dunes of north-western Denmark (2354ha), and all R. rugosa patches (1321) were recorded with GPS in 2004 and 2007. The 2004 records were used to digitize 82-161 distinct patches on the photographs. The increase in patch sizes from the older to the younger photographs was used to calculate a lateral clonal spread rate (0.42myear^-^1). Relative area increment by clonal spread was 16.4% per year, decreasing exponentially with patch size due to constant clonal lateral spre...

2009-01-01

449

Effect of varying the vertical dimension of connectors of cantilever cross-arch fixed dental prostheses in patients with severely reduced osseous support: A three-dimensional finite element analysis  

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Inadequate dimensioning of the connectors in a cantilever cross-arch fixed dental prosthesis (FDP) in perioprosthetic patients jeopardizes the prognosis of the restoration. Purpose The purpose of this study was to investigate the effect of increasing the vertical dimension (VD) on the maximum stress developed within the connectors during the static loading of a cross-arch FDP extended as a 1- and 2-unit cantilever. Material and methods Six digital models were developed, derived from a 3-dimensional (3-D) initial model. In the initial model, the teeth were prepared for metal ceramic restorations and splinted with a cross-arch FDP, extended as a 1- or 2-unit cantilever. The VDs of the connectors proximal to the retaining abutment were 3, 4, or 5 mm. A 3-D finite element ...

2010-01-01

450

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants  

International Nuclear Information System (INIS)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1992-01-01

451

ECOTRONIC - an electronic system for mixture formation  

Energy Technology Data Exchange (ETDEWEB)

Fhe ECOTRONIC system developed by Bosch und Pierburg System oHG is an electronic system for mixture formation for Otto-cycle engines complying with high operational requirements. Engineers incorporated electronic control of the quantity of mixture and mixture enrichment for supplementary functions into a reliable, low-cost system, which will also comply with future requirements concerning fuel consumption, emissions and driveability. The author of the present article reduces the carburetor down to its basic systems, explains how supplementary functions were converted from mechanical to either open or closed-loop electronic control, and describes the newly developed actuators, the control unit making use of digital technology, and the results achieved.

1984-02-01

452

Digital radiography of pulmonary abnormalities using Fuji computed radiography (FCR)  

Energy Technology Data Exchange (ETDEWEB)

Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best practical conditions were determined. (author).

1991-12-01

453

Digital radiography of pulmonary abnormalities using Fuji computed radiography (FCR)  

International Nuclear Information System (INIS)

Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best practical conditions were determined. (author).

1991-01-01

454

Digital processing to improve image quality in real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction technique, and so on. For the real-time application a contouring operation and an averaging approach can also be utilized effectively.

1985-01-01

455

Digital processing to improve image quality in real-time neutron radiography  

International Nuclear Information System (INIS)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction technique, and so on. For the real-time application a contouring operation and an averaging approach can also be utilized effectively. (orig.).

1985-01-01

456

Development of the high sensitivity real-time neutron radiography for low-flux neutron sources  

Energy Technology Data Exchange (ETDEWEB)

The authors have developed a high-sensitivity real-time neutron radiography (NR) system by the use of the low power reactor of Kinki University. The system was constructed with a high efficiency neutron-photon converter, an image intensifier and a SIT TELEVISION camera. Some digital image processing techniques were applied for improving the quality of the real-time neutron images. By the use of this system, dynamic neutron imaging was performed successfully under the condition of a weak neutron field that was about two orders of magnitude lower than that of the standard NR system. The neutron flux, calculated from the fluctuation of the neutron response of the images, was nearly equal to the value measured by the foil activation method. From this fact, the efficiency for the neutron detection of the imaging system was estimated to be almost 100%. For the purpose of developing a system with higher sensitivity, consideration of neutron statistics would be important. ...

1994-08-01

457

Development of the high sensitivity real-time neutron radiography for low-flux neutron sources  

International Nuclear Information System (INIS)

The authors have developed a high-sensitivity real-time neutron radiography (NR) system by the use of the low power reactor of Kinki University. The system was constructed with a high efficiency neutron-photon converter, an image intensifier and a SIT TELEVISION camera. Some digital image processing techniques were applied for improving the quality of the real-time neutron images. By the use of this system, dynamic neutron imaging was performed successfully under the condition of a weak neutron field that was about two orders of magnitude lower than that of the standard NR system. The neutron flux, calculated from the fluctuation of the neutron response of the images, was nearly equal to the value measured by the foil activation method. From this fact, the efficiency for the neutron detection of the imaging system was estimated to be almost 100%. For the purpose of developing a system with higher sensitivity, consideration of neutron statistics would be important. ...

1994-01-01

458

Development of linear flow rate control system for eccentric butter-fly valve  

Energy Technology Data Exchange (ETDEWEB)

Butter-fly valves are advantageous over gate, globe, plug, and ball valves in a variety of installations, particularly in the large sizes. The purpose of this project development of linear flow rate control system for eccentric butter-fly valve (intelligent butter-fly valve system). The intelligent butter-fly valve system consist of a valve body, micro controller. The micro controller consist of torque control system, pressure censor, worm and worm gear and communication line etc. The characteristics of intelligent butter-fly valve system as follows: Linear flow rate control function. Digital remote control function. guard function. Self-checking function. (author)

1999-12-01

459

Detect and classify faults using neural nets  

Energy Technology Data Exchange (ETDEWEB)

The analysis of transmission line faults is essential to the proper performance of the power system. It is required if protective relays are to take the appropriate action and in monitoring the performance of relays, circuit breakers, and other protective and control elements. The detection and classification of transmission line faults is a fundamental component of such fault analysis. Another application of fault analysis is in software packages for automated analysis of digital fault recorder (DFR) files. Recently, such a package, called DFR Assistant, was developed for substation applications. This program can be installed locally in a substation, in which case it is connected directly to the DFR via a high speed parallel link, or it can be installed at a central station, in which case it can be configured to automatically analyze events coming from all DFRs.

1996-10-01

460

Crack tip opening angle measurement through a girth weld in an X100 steel pipeline section  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Crack tip opening angle (CTOA) is becoming one of the most accepted methods for characterizing fully plastic fracture. It provides a measure of the resistance to fracture for a material in cases where there is a large degree of stable-tearing crack extension during the fracture process. Our current pipeline research uses the CTOA test as an alternative, or addition, to the CTOD (crack tip opening displacement) and the fracture energy characterization provided by the J-integral approach. A test technique was developed for measurement of CTOA that uses a modified double cantilever beam (MDCB) specimen. A digital camera and image analysis software were used to record the progression of the crack tip and to estimate the CTOA. In this article, CTOA data on crack growth orientations per...

2008-01-01

461

Common aperture multispectral sensor flight test program  

Energy Technology Data Exchange (ETDEWEB)

This paper will provide an overview of the Common Aperture Multispectral Sensor (CAMS) Hardware Demonstrator. CAMS is a linescanning sensor that simultaneously collected digital imagery over the Far-IR (8 to 12 {mu}m) and visible spectral (0.55 to 1.1 PM) spectral bands, correlated at the pixel level. CAMS was initially sponsored by the U.S. Naval Air System Commands F/A-18 program office (PMA-265). The current CAMS field tests are under the direction of Northrop-Grumman for the Defense Nuclear Agency (DNA) in support of the Follow-On Open Skies Sensor Evaluation Program (FOSEP) and are scheduled to be conducted in April 1996. 8 figs., 4 tabs.

1996-11-01

462

Color recognition system for urine analyzer  

Science.gov (United States)

In order to increase the speed of photoelectric conversion, a linear CCD is applied as the photoelectric converter instead of the traditional photodiode. A white LED is used as the light source of the system. The color information of the urine test strip is transferred into the CCD through a reflecting optical system. It is then converted to digital signals by an A/D converter. The test results of urine analysis are obtained by a data processing system. An ARM microprocessor is selected as the CPU of the system and a CPLD is employed to provide a driving timing for the CCD drive and the A/D converter. Active HDL7.2 and Verilog HDL are used to simulate the driving timing of the CPLD. Experimental results show that the correctness rate of the test results is better than 90%. The system satisfies the requirements of the color information collection of urine analyzer.

2010-08-01

463

Characterization of surface defects after flanging of metallic sheets  

British Library Electronic Table of Contents (United Kingdom)

This paper deals with surface defects of automobile outer panels, which alter significantly the vehicle quality. Such defects occur during springback, after forming or flanging steps, and are characterized by concave depression of small amplitude over the convex shape of the part. The aim of this work is to reproduce at the laboratory scale a surface defect that occurs after flanging on a geometry similar to a door upper corner. A dedicated device has been designed in order to generate small size surface defects during flanging of metallic thin sheets. The outer surface of the sample was digitalized and the spatial geometry of the defect was evaluated from curvature change along 2D profiles. This study shows that the flanging height does not influence significantly the surface defect geome...

2011-01-01

464

Ceramic Materials and Devices  

Science.gov (United States)

Course website from Cambridge on ceramic materials. This site contains eight lectures in PDF format (Adobe Reader required), two question sheets, five practicals (including answers), digital movies and further useful links. "There is a strong relationship between the structure of a material and its physical properties. The properties of a material whether mechanical, electrical, optical or magnetic, determine how it can be used in practical applications. In this course, the focus is on the structure / property relationship for ionic materials with electrical properties utilised in various transducer devices. The materials considered include perovskites, which have special polarisation properties exploited in ferroelectric, pyroelectric and piezoelectric devices. Other oxides, such as zirconia, have structures permitting rapid diffusion of ions, making them suitable for use in sensors, fuel cells and batteries. The scientific principles underlying the properties of ...

2007-02-01

465

Behaviour of steam turbine power control of large power plant units in case of network short-circuits  

International Nuclear Information System (INIS)

In order to investigate the behaviour of the turbine control system during strong pendulum motions, an analysis is carried out using a digital computer program by which the reactor, the turbine, the generator and, in a simplified way, the network can be simulated to the necessary degree. Plotter pictures can show the main physical quantities. In all cases, the turbine control system should be able to distinguish between strong pendulum amplitude with acceleration of the rotational angles and sudden release criteria. This demand can be satisfied by a simple adjustment in the Kraftwerk Union turbine control system. Only a few seconds after shut-off of a severe network failure, the turbines are back to their rated power, thus contributing to reliability of supply in this critical network situation. (orig.).

1978-11-24

466

Automatic calculation of bathymetry for coastal hydrodynamic models  

British Library Electronic Table of Contents (United Kingdom)

A methodology is proposed to facilitate the construction of gridded bathymetry data for the use of hydrodynamic models on the continental shelf. It relies on the carrying out of three successive tasks: (1) automatic selection of records of better quality among multiple sets of overlapping data; (2) elimination of data points located on land; and (3) taking into account the shoreline as bathymetric data. Algorithms are proposed to perform sorting of the records according to their quality as well as masking by the coastline. The suggested method facilitates the updating of bathymetry data and optimizes their use. It enables automatic execution of all the tasks and building of new digital bathymetry models in a few hours, without action from the operator. The method has been tested many times...

2011-01-01

467

Application of PDA forest fire monitoring based on web service technology  

British Library Electronic Table of Contents (United Kingdom)

The difficulty in information communication and sharing are major problems for forest fire monitoring and early warning in China. As authors, we applied web service technology to a personal digital assistant (PDA) forest fire monitoring system and propose the framework of a monitoring system based on service-oriented architecture (SOA). At the same time, we describe the composition and function of web services from a server side and a client side. The method for developing a web service invocation engine on the PDA is introduced in detail. Finally, an example of a fire danger rating and fire weather services system are established, based on the Beijing Forest Fire Control System. The results show that the PDA forest fire monitoring system based on web services can effectively take advantag...

2009-01-01

468

Analysis of the changes of vegetation coverage of western Beijing mountainous areas using remote sensing and GIS  

British Library Electronic Table of Contents (United Kingdom)

Mentougou District acts as a crucial component in the ecological buffer in western Beijing mountainous areas, Beijing, China. Using two Landsat MSS/TM images acquired on July 14, 1979 and July 23, 2005, the vegetation coverage of Mentougou District was calculated based on normalized difference vegetation index and spectral mixture analysis (NDVI-SMA) model. Its temporal and spatial changes were analyzed according to digital elevation model (DEM) image, social and economic data. The results showed that the vegetation coverage decreased from 76.4% in 1979 to 72.7% in 2005. Vegetation degradation was probably the result of human disturbance, such as outspreading of resident areas, and coal and stone mining activities, while vegetation restoration might be contributed by the combined effects o...

2009-01-01

469

Analysis of even harmonics generation in an isolated electric power system  

British Library Electronic Table of Contents (United Kingdom)

Harmonics bred from loads are mainly odd order because the current waveforms have half-wave symmetry. Since the even harmonics are negligibly small, they generally are not measured in electric power systems. However, even harmonics were measured at a 500/275/154 kV substation in Hokuriku Electric Power Company after a transmission line fault was corrected. The even harmonics caused malfunctions of protective digital relays because the relays used 4th harmonics at the input filter as the automatic supervisory signal. This paper describes mechanisms of generation of the even harmonics by comparing the measured waveforms with the ATP-EMTP simulation results. Analysis of these results has clearly shown that there are three different mechanisms of generation of even harmonics. The first mechani...

2009-01-01

470

An Electronic Payment System to Ensure Cost Effectiveness with Easy Security Incorporation for the Developing Countries  

CERN Document Server

With the rapid growth of Information and Communication Technology, Electronic commerce is now acting as a new means of carrying out business transactions through electronic means such as Internet environment. To avoid the complexities associated with the digital cash and electronic cash, consumers and vendors are looking for credit card payments on the Internet as one possible time-tested alternative. This gave rise of the on-line payment processing using a third-party verification; which is not suitable for the developing countries in most of the cases because of the excessive costs associated with it for maintenance and establishment of an online third-party processor. As a remedy of this problem, in this paper, we have proposed a framework for easy security incorporation in credit card based electronic payment system without the use of an on-line third- party processor; which tends to be low cost and effective for the developing countries.

2006-01-01

471

Advanced readout integrated circuit signal processing  

Science.gov (United States)

Readout integrated circuits (ROICs) for focal plane arrays (FPAs) have become increasingly complex to meet the needs of modern infrared systems. BAE Systems has pioneered a number of advanced signal processing architectures for FPA ROICs. Demonstrated signal processing capabilities of BAE Systems FPAs include analog-to-digital conversion, offset subtraction, individual pixel automatic gain compensation, transient noise suppression, on-FPA defect deselection, reconfigurable pixels, spatial neural network processing and subframe noise averaging. BAE Systems FPA advanced signal processing is not just for demonstrations, but is used in many of their deliverable FPAs, improving real system performance.

2006-06-01

472

Acute femoral neck fracture  

International Nuclear Information System (INIS)

Ten patients with traumatic femoral neck fracture were studied with MR imaging (0.5 T, Magnetom, Siemens): unenhanced (multiecho, TR/TE = 1,600/30--240 [repetition time/echo time, msec]; gradient echo, TR/TE = 315/14, #theta# = 90 degrees) and Gd-DTPA enhanced (0.1 mM/kg body weight, Magnevist, Schering; gradient echo, TR/TE = 315/14, #theta# = 90 degrees). MR images were compared with clinical-radiographic findings. Digital subtraction angiography of the femoral head (FH) in five patients showed complete interruption of blood supply to the FH in three patients (signal intensity of FH did not increase on postcontrast images) and intact FH arteries in two patients (FH signal increased on postcontrast images, as did the healthy-side signal).

473

A study of reconstruction algorithms and filters for an industrial X-ray tomography system  

Energy Technology Data Exchange (ETDEWEB)

Computed tomography (CT) has been incorporated in an industrial Diode-Array Digital Radiography (DADR) system. An input data size of 512 pixel points x 400 projections yielded a 400x400 output image matrix. Reconstruction algorithms used are the filtered backprojection (FBP) and the direct Fourier reconstruction (DFR). Various filters were used in the FBP reconstruction process and their effects on image quality were evaluated. A spatial resolution of 100 {mu}m was measured with a block of plates and a minimum detectable feature size in the range of 10-100 {mu}m was measured using thin wires. Industrial specimens imaged have included ceramic samples, ball bearings and integrated circuits. A number of engineering problems have been solved, such as adjustment of the X-ray source, centering of the rotator spindle in the view field and beam-hardening corrections. (orig.).

1990-12-20

474

A new adaptive power system stabilizer using a Lyapunov design technique  

Energy Technology Data Exchange (ETDEWEB)

A technique for designing an adaptive power system stabilizer is presented which improves the dynamic stability of power systems by effectively increasing the damping torque of the synchronous generator in the system. The proposed adaptive stabilizer is optimal in the sense of minimizing a specified performance condition. A characteristic feature of using a Lyapunov techniques is that it leads to stable adaptation loops. The dynamic responses following a step disturbance by digital simulations are obtained by means of three types of stabilizers: the conventional power system stabilizer, a frequency-response-based optimal adaptive stabilizer and the proposed Lyapunov stabilizer. Simulation results on a typical single-machine/infinite-bus system illustrate the superiority of the proposed technique. (author).

1990-04-01

475

A large solid angle, high stopping power Bragg curve spectrometer for coincidence measurements  

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power, Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. The detector design was aided by the results of computer simulations of the electron collection process in the detector, and of the signal processing in the electronics. The signals from the Bragg curve spectrometer are recorded in a waveform digitizer and the Bragg peak height, range, position and pileup rejection information are determined from software analysis of the recorded signals. Factors limiting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

1991-09-01

476

A large solid angle, high stopping power Bragg curve spectrometer for coincidence measurements  

International Nuclear Information System (INIS)

A large acceptance, high stopping power, Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. The detector design was aided by the results of computer simulations of the electron collection process in the detector, and of the signal processing in the electronics. The signals from the Bragg curve spectrometer are recorded in a waveform digitizer and the Bragg peak height, range, position and pileup rejection information are determined from software analysis of the recorded signals. Factors limiting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

477

A Study on the Photometric Redshifts of Faint Blue Galaxies in CDFS  

British Library Electronic Table of Contents (United Kingdom)

From the COMBO-17 digital sky survey data, 1,231 faint blue galaxies with photometric redshifts of 0.1

2011-01-01

478

A Danish decision-support GIS tool for management of urban air quality and human exposures  

Energy Technology Data Exchange (ETDEWEB)

A new prototype model system named AirGIS has been developed to support local authorities in air quality management for big Danish cities. The system is based on the Danish operational street pollution model (OSPM), technical and cadastral digital maps and Danish national administrative databases on buildings, cadastres and populations. It applies a geographic information system (GIS). AirGIS estimates ambient air pollution levels at high temporal and spatial resolutions. The model system enables mapping of traffic emissions, air quality levels and human exposures at residence addresses, at workplace addresses and in streets. Mapping and scenario results can be compared with air quality limits. Impact assessment of traffic air pollution abatement measures can also be carried out. (author)

2001-07-01

479

3-D depth migration via McClellan transformations  

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional seismic wavefields may be extrapolated in depth, one frequency at a time, by two-dimensional convolution with a circularly symmetric, frequency- and velocity-dependent filter. This depth extrapolation, performed for each frequency independently, lies at the heart of 3-D finite-difference depth migration. The computational efficiency of 3-D depth migration depends directly on the efficiency of this depth extrapolation. McClellan transformations provide an efficient method for both designing and implementing two-dimensional digital filters that have a particular form of symmetry, such as the circularly symmetric depth extrapolation filters used in 3-D depth migration. Given the coefficients of one-dimensional, frequency- and velocity-dependent filters used to accomplish 2-D depth migration, McClellan transformations lead to a simple and efficient algorithm for 3-D depth migration. 21 refs., 12 figs.

1990-01-01

480

Use of SPOT satellite imagery to obtain GIS input for oil spill models  

Energy Technology Data Exchange (ETDEWEB)

Satellite imagery is a cost-effective tool for creating and updating basemaps of coastal zones, especially where existing maps and aerial photographs are unavailable, are out-of-date, or provide limited information. Reliable maps of coastal zones are particularly important for oil spill modelling programs. Color IR (multispectral) images with 20m x 20m ground resolution and black & white (panchromatic) images with 10m x 10m ground resolution of many coastlines around the globe have been acquired from 1986 to present by SPOT Image Corporation. We have digitally merged same-day SPOT panchromatic and multispectral imagery to provide maximum spatial resolution and permit excellent color differentiation of coastal zone features. This combination adequately discriminates individual features, including pipelines, offshore platforms, storage tanks, jetties, and shoreline type. The SPOT images were interpreted within a workstation environment and the coastline ...

1995-04-01

481

The clinical significance of Fuji computed radiography on lateral chest radiogram  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to clarify the benefits of digital lateral chest radiogram. In the basic study, the modulation transfer factor (MTF) and the wiener spectra (WS) of conventional screen film (CSF) and Fuji computed radiography (FCR) were measured. The visibility of the simulated nodules on FCR using 3 human bodies was subjectively compared with that on CSF by 13 observers. In the clinical study, the visibility of the normal structures on FCR was subjectively compared with that on CSF using 50 lateral chest radiograms by 10 observers. The diagnostic performance to detect pulmonary nodules on FCR was also compared with that on CSF using each 30 positive and negative cases by 8 observers. In the basic study, the MTF of FCR was superior to that of CSF, and the WS of FCR displayed in half size was superior to that of CSF. In all exposure conditions, the visibility of the nodules on FCR in the pulmonary apex was inferior to that on CSF, while FCR was superior ...

1995-02-01

482

The clinical significance of Fuji computed radiography on lateral chest radiogram  

International Nuclear Information System (INIS)

The purpose of this study was to clarify the benefits of digital lateral chest radiogram. In the basic study, the modulation transfer factor (MTF) and the wiener spectra (WS) of conventional screen film (CSF) and Fuji computed radiography (FCR) were measured. The visibility of the simulated nodules on FCR using 3 human bodies was subjectively compared with that on CSF by 13 observers. In the clinical study, the visibility of the normal structures on FCR was subjectively compared with that on CSF using 50 lateral chest radiograms by 10 observers. The diagnostic performance to detect pulmonary nodules on FCR was also compared with that on CSF using each 30 positive and negative cases by 8 observers. In the basic study, the MTF of FCR was superior to that of CSF, and the WS of FCR displayed in half size was superior to that of CSF. In all exposure conditions, the visibility of the nodules on FCR in the pulmonary apex was inferior to that on CSF, while FCR was superior ...

1995-01-01

483

The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),  

Energy Technology Data Exchange (ETDEWEB)

This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends ...

2007-11-02

484

The Advanced Photon Source injection timing system  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Photon Source consists of five accelerators. The injection timing system provides the signals required to cause a bunch emitted from the electron gun to navigate through intermediate accelerators to a specific bucket (1 out of 1296) within the storage ring. Two linacs and a positron accumulator ring operate at 60Hz while a booster synchrotron ramps and injects into the storage ring at 2Hz. The distributed, modular VME/VXI-based injection timing system is controlled by two EPICS-based input/output controllers (IOCs). Over 40 VME/VXI cards have been developed to implement the system. Card types range from 352MHz VXI timing modules to VME-based fiber optic fanouts and logic translators/drivers. All timing is distributed with fiber optics. Timing references are derived directly from machine low-level rf of 9.77MHz and 352MHz. The timing references provide triggers to programmable delay generators. Three grades of timing are provided. Precision timing is derived from commercial ...

1995-12-31

485

Steepest changes of a probability-based cost function for delineation of mammographic masses: A validation study  

International Nuclear Information System (INIS)

Our purpose in this work was to develop an automatic boundary detection method for mammographic masses and to rigorously test this method via statistical analysis. The segmentation method utilized a steepest change analysis technique for determining the mass boundaries based on a composed probability density cost function. Previous investigators have shown that this function can be utilized to determine the border of the mass body. We have further analyzed this method and have discovered that the steepest changes in this function can produce mass delineations that include extended projections. The method was tested on 124 digitized mammograms selected from the University of South Florida's Digital Database for Screening Mammography (DDSM). The segmentation results were validated using overlap, accuracy, sensitivity, and specificity statistics, where the gold standards were manual traces provided by two expert radiologists. We have concluded ...

2004-10-01

486

Real-time monitoring of dosimetry and image quality during digital radiology examinations  

International Nuclear Information System (INIS)

Objective: To explore the feasibility of real-time monitoring exposure dose and image quality by using the data stored in the DICOM image archive of direct digital radiography system. Methods: Model TO. 16 was exposed, the current increased gradually from 0.5 to 125 mAs. The displayed number of model A( diameter 11.1 mm), D (diameter 4.0 mm) and J( diameter 0.7 mm) were recorded, and the detect factors (H_T) was also calculated. Images were sent to workstation before the end of DR examination. An automatic procedure was implemented to extract dose data and exposure parameters from the DICOM header file. Maximum, minimum and 3rd quartile values were preinstalled. Mean values exceeding the threshold trigger alarm signal to guide radiologist to explore the cause. Results: When the current of point A was less than 10 mAs and the current of point D and J were less than 16 mAs, the detect factor (H_T) increased with the rise of current. While point A located within ...

2009-12-01

487

Pulmonary nodule detection of chest phantom with CRT images; Comparison with conventional radiography (film-screen system) and FCR hardcopy  

Energy Technology Data Exchange (ETDEWEB)

Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and displayed four images as a subsidiary diagnosis. The upper two images were displayed ...

1989-08-01

488

Pulmonary nodule detection of chest phantom with CRT images  

International Nuclear Information System (INIS)

Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and displayed four images as a subsidiary diagnosis. The upper two images were displayed ...

1989-01-01

489

Process-integrated online monitoring of safety-relevant aluminum airbag pressure vessel components for a combined defect detection and material property determination by using contactless NDT (EMUS and EC)  

Energy Technology Data Exchange (ETDEWEB)

Airbag pressure vessels for the north-American market mainly are made by forging and by the use of steel alloys. In Europe aluminum alloys are common and the manufacturing process is extrusion of circular blanks - made from cold rolled plates - in a form applying a 100 t press at room temperature. Then by heat treatment the strength/hardness of the material is properly adjusted and after that the pressure vessel parts have to be continuously inspected with an inspection and handling cycle time of 3 s. Inspection of the axis-symmetric parts is asked for surface breaking extrusion defects as well as for surface parallel delaminations in the bulk volume. Furthermore, the material strength is a quality characteristic that has to be nondestructively registered and documented. The inspection is performed by eddy current probes and an EMAT, of which the eddy current impedance measurements are used for surface breaking extrusion defect detection and sizing (single frequency technique with ...

1999-07-01

490

Performing Re-mediation in Graphical Cyberspace: Mediating Agency, Body and Identity in Virtual Interactional Practices  

DEFF Research Database (Denmark)

Promoted as the first academic conference to be held completely in graphical cyberspace, Avatars 98 took place in November 1998. The virtual conference site was built and inhabited using software that supports multi-party presence over the Internet in a simulated, navigable environment. During the conference, avatar-embodied speakers using text chat performed to virtual audiences, 'webcams' (re)broadcast live video images of CNN and other remote sites, and a 'webcast' sent audiovisual representations captured by video camera of certain key participants in their physical locations. Such a novel and spectacular multi-media event raises many questions. How do we conceive of the recent developments in media technology and social computing that are impacting on what we have traditionally called 'the mass media'? How is interaction and talk mediated and adapted to new media genres? And how do participants construct and maintain senseful talk in a sometimes bewildering, 'inhabited', ...

491

Performance study of teleradiology network systems with CRT monitors. ROC analysis of an observation study of simulated lung nodules  

International Nuclear Information System (INIS)

To evaluate the diagnostic performance of commercially available CRT monitors used in a teleradiology system by determining the rate of detection of simulated lung nodules. Three types of CRT monitors were tested in the observation study. They had matrix sizes of 1024 x 768 (16 inches, color), 1024 x 768 (20 inches, color) and 1600 x 1125 (24 inches, black and white). Twenty chest radiographs were obtained by Fuji computed radiography (FCR) of an anthropomorphic chest phantom with ten simulated nodules on its surface. These FCR films were digitized by a film digitizer with 125 DPI (1024 x 1024 matrix sizes) and 12 bit gray scales, and the image data were transferred from Shinshu University Hospital to other hospitals where interpretation was carried out by the radiologists. Ten radiologists of three hospitals were asked to interpret independently both the original FCR films and the images shown on the CRT monitors and to indicate the presence ...

492

High-temperature ferromagnetism in laser-deposited layers of silicon and germanium doped with manganese or iron impurities  

Energy Technology Data Exchange (ETDEWEB)

The paper reports on the results of a study of the synthesis conditions effects on magnetic and transport properties of nanosized layers of high-T{sub c} diluted magnetic semiconductors (DMS), such as Ge:Mn, Si:Mn and Si:Fe, fabricated by laser-plasma deposition over a wide range of the growth temperature, T{sub g}=(20-550) deg. C on single-crystal GaAs or Al{sub 2}O{sub 3} substrates. Ferromagnetism of the layers was detected by measurement data of the magneto-optical Kerr effect, anomalous Hall effect, negative magnetoresistance and ferromagnetic resonance (FMR) at 5-500 K. The optimum growth temperature, T{sub g}, for Si:Mn/GaAs layers with T{sub c}{approx}400 K is shown to be about 400 deg. C. The Si:Mn/Al{sub 2}O{sub 3} layers with 35% of Mn have the metal-type of conductivity with manifestation of magnetization up to room temperature. Different types of uniformly doped structures and digital alloys have been investigated. In contrast to GaSb:Mn films, ...

2009-04-15

493

Global positioning automatic vehicle location system  

Energy Technology Data Exchange (ETDEWEB)

Los Alamos National Laboratory (LANL) is a unique facility covering over 43 square miles. The Emergency Management and Response Office (EM&R) is required to respond, provide Incident Command (IC), and coordination for all Laboratory emergencies. This requires IC`s and support staff to respond to the actual scene of the incident. Since the IC is under numerous constraints and stress, the office wanted the capability of locating the EM&R vehicles on an electronic map. An automated vehicle location (AVL) system was required for the additional safety of the emergency response personal. The requirements for the AVL system include total automatic tracking and low cost. After careful consideration, it was determined that the most efficient and cost effective system would be based on packet radio technology as the transmission media. The location is determined by the Department of Defense Global Positioning System (GPS). The system that was designed and constructed required four ...

1997-03-01

494

Fuji computed radiography (FCR) for the diagnosis of spinal disorders  

Energy Technology Data Exchange (ETDEWEB)

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the ...

1987-04-01

495

Field investigation of radio network usage at the dismounted infantry section level  

Science.gov (United States)

The Soldier Information Requirements Technology Demonstration (SIREQ TD) project is an experimentation program to identify technologies that significantly enhance the performance of our future soldiers. One of the study series involved a 2 x 2 factorial comparison of the benefits of digital maps over paper maps, and the use of radios vs. no radios. Thirty-two Canadian regular force infantry soldiers performed force-on-force tactical assault missions in wooded terrain, with each soldier participating in all four test conditions. The radios were configured to operate in 4 subnets: 1 channel for each of the 2 Assault Groups (4 soldiers on a channel); a Section Commander/2IC channel; and an all-users channel. Note that in the no-radio conditions soldiers still operated the press-to-talk switch to allow recording of communications, but the speaker volume was set to zero. All communications were date/time stamped, identified as to the user and channel, and the audio was ...

2006-06-01

496

Digital subtraction angiography (DSA) using Fuji computed radiography (FCR)  

International Nuclear Information System (INIS)

A vessel phantom suitable for evaluation of spatial and contrast resolution of FCRDSA (Fuji Computed Radiography, digital subtraction angiography) has been developed and used for determining resolution. The effects of iodine concentration, low dose exposure, and acryl thickness on the resolution were evaluated in FCRDSA, and FCRDSA images were compared with film substraction with use of this phantom. It has been proven that limitation of resolution of FCRDSA was 5 % 1 mm and about 1/4 dose exposure compared with conventional film exposure was clinically acceptable. Dye dilution method was useful to determine a program of IVDSA with imaging plate. It has been proven that time to appearance and time to peak of time-concentration curve of dye dilution method closely correlate to time to appropriate image of DSA in the neck, the chest, and the abdomen. 106 cases of IVDSA and 130 cases of IADSA using FCR in Tohoku University Hospital from January through December 1984 ...

1984-12-01

497

ARDEC transition armature study. Progress report No. 3, October 1--November 30, 1991  

Energy Technology Data Exchange (ETDEWEB)

This third report covers the period October 1 to November 30, 1991. During this period the authors: (1) fabricated a test fixture for studying hybrid armature brush behavior, (2) reactivated a 140kJ, 1MA capacitor bank, (3) reactivated 25 channels digital data acquisition and reduction system and (4) concluded the use of a DNA funded railgun would serve as the most expedient means to acquire a railgun test bed. Fabrication of a plasma brush test fixture for studying the formation, evolution and stability of plasma brushes was completed. The fixture will serve to study plasma brush parameters, such as brush length and voltage drop, as a function of initial solid foil mass, gap size and current concentration. A 4OkV, 168{mu}f, 140kJ capacitor bank capable of providing more than 1MA of current was reactivated. (The LLNL bank had been developed for opening switch research which was successfully completed.) The bank will be used to power the test fixture with 10{mu}s, ...

1992-05-13

498

A wavelet-fuzzy combined approach for classification and location of transmission line faults  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a real-time wavelet-Fuzzy combined approach for digital relaying. The algorithm for fault classification employs wavelet multi resolution analysis (MRA) to overcome the difficulties associated with conventional voltage and current based measurements due to effect of factors such as fault inception angle, fault impedance and fault distance. The proposed algorithm for fault location, different from conventional algorithms that are based on deterministic computations on a well-defined model to be protected, employs wavelet transform together with fuzzy logic. The wavelet transform captures the dynamic characteristics of the non-stationary transient fault signals using wavelet MRA coefficients. The fuzzy logic is employed to incorporate expert evaluation through fuzzy inference system (FIS) so as to extract important features from wavelet MRA coefficients for obtaining coherent conclusions regarding fault location. Computer simulations using MATLAB ...

2007-11-15

499

A comprehensive understanding of the efficacy of N-Ring hardening methodologies in SiGe HBTs  

International Nuclear Information System (INIS)

We investigate the efficacy of mitigating radiation-based single event effects (SEE) within circuits incorporating SiGe heterojunction bipolar transistors (HBTs) built with an N-Ring, a transistor-level layout-based radiation hardened by design (RHBD) technique. Previous work of single-device ion-beam induced charge collection (IBICC) studies has demonstrated significant reductions in peak collector charge collection and sensitive area for charge collection; however, few circuit studies using this technique have been performed. Transient studies performed with Sandia National Laboratory's (SNL) 36 MeV 16O microbeam on voltage references built with N-Ring SiGe HBTs have shown mixed results, with reductions in the number of large voltage disruptions in addition to new sensitive areas of low-level output voltage disturbances. Similar discrepancies between device-level IBICC results and circuit measurements are found for the case of digital shift registers implemented ...

2010-07-19