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Sample records for filtrado digital difuso

  1. Digital Libraries.

    ERIC Educational Resources Information Center

    Fox, Edward A.; Urs, Shalini R.

    2002-01-01

    Provides an overview of digital libraries research, practice, and literature. Highlights include new technologies; redefining roles; historical background; trends; creating digital content, including conversion; metadata; organizing digital resources; services; access; information retrieval; searching; natural language processing; visualization;…

  2. Digital Preservation.

    ERIC Educational Resources Information Center

    Yakel, Elizabeth

    2001-01-01

    Reviews research on digital preservation issues, including born-digital and digitally recreated documents. Discusses electronic records research; metadata and other standards; electronic mail; Web-based documents; moving images media; selection of materials for digitization, including primary sources; administrative issues; media stability…

  3. Digital Citizenship

    ERIC Educational Resources Information Center

    Isman, Aytekin; Canan Gungoren, Ozlem

    2014-01-01

    Era in which we live is known and referred as digital age.In this age technology is rapidly changed and developed. In light of these technological advances in 21st century, schools have the responsibility of training "digital citizen" as well as a good citizen. Digital citizens must have extensive skills, knowledge, Internet and …

  4. Digital Natives or Digital Tribes?

    ERIC Educational Resources Information Center

    Watson, Ian Robert

    2013-01-01

    This research builds upon the discourse surrounding digital natives. A literature review into the digital native phenomena was undertaken and found that researchers are beginning to identify the digital native as not one cohesive group but of individuals influenced by other factors. Primary research by means of questionnaire survey of technologies…

  5. Digital metamaterials

    NASA Astrophysics Data System (ADS)

    Della Giovampaola, Cristian; Engheta, Nader

    2014-12-01

    Balancing complexity and simplicity has played an important role in the development of many fields in science and engineering. One of the well-known and powerful examples of such balance can be found in Boolean algebra and its impact on the birth of digital electronics and the digital information age. The simplicity of using only two numbers, ‘0’ and ‘1’, in a binary system for describing an arbitrary quantity made the fields of digital electronics and digital signal processing powerful and ubiquitous. Here, inspired by the binary concept, we propose to develop the notion of digital metamaterials. Specifically, we investigate how one can synthesize an electromagnetic metamaterial with a desired permittivity, using as building blocks only two elemental materials, which we call ‘metamaterial bits’, with two distinct permittivity functions. We demonstrate, analytically and numerically, how proper spatial mixtures of such metamaterial bits lead to elemental ‘metamaterial bytes’ with effective material parameters that are different from the parameters of the metamaterial bits. We then apply this methodology to several design examples of optical elements, such as digital convex lenses, flat graded-index digital lenses, digital constructs for epsilon-near-zero (ENZ) supercoupling and digital hyperlenses, thus highlighting the power and simplicity of the methodology.

  6. Digital metamaterials.

    PubMed

    Della Giovampaola, Cristian; Engheta, Nader

    2014-12-01

    Balancing complexity and simplicity has played an important role in the development of many fields in science and engineering. One of the well-known and powerful examples of such balance can be found in Boolean algebra and its impact on the birth of digital electronics and the digital information age. The simplicity of using only two numbers, '0' and '1', in a binary system for describing an arbitrary quantity made the fields of digital electronics and digital signal processing powerful and ubiquitous. Here, inspired by the binary concept, we propose to develop the notion of digital metamaterials. Specifically, we investigate how one can synthesize an electromagnetic metamaterial with a desired permittivity, using as building blocks only two elemental materials, which we call 'metamaterial bits', with two distinct permittivity functions. We demonstrate, analytically and numerically, how proper spatial mixtures of such metamaterial bits lead to elemental 'metamaterial bytes' with effective material parameters that are different from the parameters of the metamaterial bits. We then apply this methodology to several design examples of optical elements, such as digital convex lenses, flat graded-index digital lenses, digital constructs for epsilon-near-zero (ENZ) supercoupling and digital hyperlenses, thus highlighting the power and simplicity of the methodology. PMID:25218061

  7. Digital Opportunity

    ERIC Educational Resources Information Center

    Azzam, Amy M.

    2006-01-01

    This article details the content of a recently released report from the Children's Partnership titled "Measuring Digital Opportunity for America's Children: Where We Stand and Where We Go From Here". On the basis of 40 indicators, the report's Digital Opportunity Measuring Stick showed how U.S. children and young adults use information and…

  8. Digital TMI

    NASA Technical Reports Server (NTRS)

    Rios, Joseph

    2012-01-01

    Presenting the current status of the Digital TMI project to visiting members of the FAA Command Center. Digital TMI is an effort to store national-level traffic management initiatives in a standards-compliant manner. Work is funded by the FAA.

  9. Digital Discrimination

    ERIC Educational Resources Information Center

    Blansett, Jim

    2008-01-01

    In recent years, the Internet has become a digital commons of commerce and education. However, accessibility standards have often been overlooked online, and the digital equivalents to curb-cuts and other physical accommodations have only rarely been implemented to serve those with print disabilities. (A print disability can be a learning…

  10. Digital Roundup

    ERIC Educational Resources Information Center

    Horn, Michael B.

    2013-01-01

    State policy is crucial to the spread of digital-learning opportunities at the elementary and secondary level. A review of recent legislative action reveals policies that are constantly in flux and differ quite markedly from one state to another. Some have hoped for model digital-learning legislation that could handle all the various issues…

  11. Why Digitize?

    ERIC Educational Resources Information Center

    Smith, Abby

    This paper is a response to discussions of digitization at meetings of the National Humanities Alliance (NHA). NHA asked the Council on Library and Information Resources (CLIR) to evaluate the experiences of cultural institutions with digitization projects to date and to summarize what has been learned about the advantages and disadvantages of…

  12. Digital Epidemiology

    PubMed Central

    Salathé, Marcel; Bengtsson, Linus; Bodnar, Todd J.; Brewer, Devon D.; Brownstein, John S.; Buckee, Caroline; Campbell, Ellsworth M.; Cattuto, Ciro; Khandelwal, Shashank; Mabry, Patricia L.; Vespignani, Alessandro

    2012-01-01

    Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges. PMID:22844241

  13. Digital clubbing

    PubMed Central

    Sarkar, Malay; Mahesh, D. M.; Madabhavi, Irappa

    2012-01-01

    Digital clubbing is an ancient and important clinical signs in medicine. Although clubbed fingers are mostly asymptomatic, it often predicts the presence of some dreaded underlying diseases. Its exact pathogenesis is not known, but platelet-derived growth factor and vascular endothelial growth factor are recently incriminated in its causation. The association of digital clubbing with various disease processes and its clinical implications are discussed in this review. PMID:23243350

  14. Digital photography

    PubMed Central

    Windsor, J S; Rodway, G W; Middleton, P M; McCarthy, S

    2006-01-01

    Objective The emergence of a new generation of “point‐and‐shoot” digital cameras offers doctors a compact, portable and user‐friendly solution to the recording of highly detailed digital photographs and video images. This work highlights the use of such technology, and provides information for those who wish to record, store and display their own medical images. Methods Over a 3‐month period, a digital camera was carried by a doctor in a busy, adult emergency department and used to record a range of clinical images that were subsequently transferred to a computer database. Results In total, 493 digital images were recorded, of which 428 were photographs and 65 were video clips. These were successfully used for teaching purposes, publications and patient records. Conclusions This study highlights the importance of informed consent, the selection of a suitable package of digital technology and the role of basic photographic technique in developing a successful digital database in a busy clinical environment. PMID:17068281

  15. Digital radiography.

    PubMed

    Mattoon, J S

    2006-01-01

    Digital radiography has been used in human medical imaging since the 1980s with recent and rapid acceptance into the veterinary profession. Using advanced image capture and computer technology, radiographic images are viewed on a computer monitor. This is advantageous because radiographic images can be adjusted using dedicated computer software to maximize diagnostic image quality. Digital images can be accessed at computer workstations throughout the hospital, instantly retrieved from computer archives, and transmitted via the internet for consultation or case referral. Digital radiographic data can also be incorporated into a hospital information system, making record keeping an entirely paperless process. Digital image acquisition is faster when compared to conventional screen-film radiography, improving workflow and patient throughput. Digital radiography greatly reduces the need for 'retake' radiographs because of wide latitude in exposure factors. Also eliminated are costs associated with radiographic film and x-ray film development. Computed radiography, charged coupled devices, and flat panel detectors are types of digital radiography systems currently available. PMID:16971994

  16. Digital Collections, Digital Libraries & the Digitization of Cultural Heritage Information.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2002-01-01

    Discusses digital collections and digital libraries. Topics include broadband availability; digital rights protection; content, both non-profit and commercial; digitization of cultural content; sustainability; metadata harvesting protocol; infrastructure; authorship; linking multiple resources; data mining; digitization of reference works;…

  17. Digital caliper

    USGS Publications Warehouse

    Cable, Louella E.

    1967-01-01

    The large number of measurements needed to describe fully the characteristics of biological specimens and other objects has always been tedious and time consuming. The work can be done much more rapidly and with greater accuracy with a digital caliper recently developed by us. The digital caliper is a new electronic instrument built to measure objects precisely throughout the range of 0.1 mm to 1.0 m. Calipers of several different discrete sizes make it possible to select the most convenient unit for the particular range of length and degree of accuracy desired.

  18. Digital Radiography

    NASA Technical Reports Server (NTRS)

    1986-01-01

    System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

  19. Digital Batteries

    NASA Astrophysics Data System (ADS)

    Hubler, Alfred

    2009-03-01

    The energy density in conventional capacitors is limited by sparking. We present nano-capacitor arrays, where - like in laser diodes and quantum wells [1] - quantization prevents dielectric breakthrough. We show that the energy density and the power/weight ratio are very high, possibly larger than in hydrogen [2]. Digital batteries are a potential clean energy source for cars, laptops, and mobile devices. The technology is related to flash drives. However, because of the high energy density, safety is a concern. Digital batteries can be easily and safely charged and discharged. In the discharged state they pose no danger. Even if a charged digital battery were to explode, it would produce no radioactive waste, no long-term radiation, and probably could be designed to produce no noxious chemicals. We discuss methodologies to prevent shorts and other measures to make digital batteries safe. [1] H. Higuraskh, A. Toriumi, F. Yamaguchi, K. Kawamura, A. Hubler, Correlation Tunnel Device, U. S. Patent No. 5,679,961 (1997) [2] Alfred Hubler, http://server10.how-why.com/blog/

  20. Digital Tidbits

    ERIC Educational Resources Information Center

    Kumaran, Maha; Geary, Joe

    2011-01-01

    Technology has transformed libraries. There are digital libraries, electronic collections, online databases and catalogs, ebooks, downloadable books, and much more. With free technology such as social websites, newspaper collections, downloadable online calendars, clocks and sticky notes, online scheduling, online document sharing, and online…

  1. Digital Badges

    ERIC Educational Resources Information Center

    Frederiksen, Linda

    2013-01-01

    Unlike so much of the current vocabulary in education and technology that seems to stir more confusion than clarity, most public service librarians may already have a general idea about digital badges. As visual representations of individual accomplishments, competencies or skills that are awarded by groups, institutions, or organizations, they…

  2. Digital books.

    PubMed

    Wink, Diane M

    2011-01-01

    In this bimonthly series, the author examines how nurse educators can use the Internet and Web-based computer technologies such as search, communication, and collaborative writing tools; social networking and social bookmarking sites; virtual worlds; and Web-based teaching and learning programs. This article describes digital books. PMID:22024672

  3. Digital psychiatry.

    PubMed

    Tang, S; Helmeste, D

    2000-02-01

    The American managed care movement has been viewed as a big experiment and is being watched closely by the rest of the world. In the meanwhile, computer-based information technology (IT) is changing the practice of medicine, much more rapidly than managed care. A New World of digitized knowledge and information has been created. Although literature on IT in psychiatry is largely absent in peer-reviewed psychiatric journals, IT is finding its way into all aspects of medicine, particularly psychiatry. Telepsychiatry programs are becoming very popular. At the same time, medical information sites are flourishing and evolving into a new health-care industry. Patient-physician information asymmetry is decreasing as patients are gaining easy access to medical information hitherto only available to professionals. Thus, psychiatry is facing another paradigm shift, at a time when most attention has been focused on managed care. In this new digital world, knowledge and information are no longer the sole property of professionals. Value will migrate from traditional in-person office-based therapy to digital clinical products, from in-person library search and classroom didactic instruction to interactive on-line searches and distance learning. In this time of value migration, psychiatrists have to determine what their 'distinctive competence' is and where best to add value in the health-care delivery value chain. The authors assess the impact of IT on clinical psychiatry and review how clinical practice, education and research in psychiatry are expected to change in this emerging digital world. PMID:15558872

  4. Scanning for Digitization Projects

    ERIC Educational Resources Information Center

    Wentzel, Larry

    2007-01-01

    Librarians and archivists find themselves facing the prospect of digitization. Everyone is doing it, everyone needs it. Discussions rage nationally and internationally concerning what to digitize and the best means to present and retain digital objects. Digitization is the act of making something digital, expressing a physical object "in numerical…

  5. Digital demodulator

    NASA Technical Reports Server (NTRS)

    Shull, T. A. (Inventor)

    1982-01-01

    A digital demodulator for converting pulse code modulated data from phase shift key (PSK) to non return to zero (NRZ) and to biphase data is described. The demodulator is composed of standard integrated logic circuits. The key to the demodulation function is a pair of cross coupled one shot multivibrators and which with a flip-flop produce the NRZ-L is all that is required, the circuitry is greatly simplified and the 2(v) times bit rate contraint can be removed from the carrier. A flip-flop, an OR gate, and AND gate and a binary counter generate the bit rate clock (BTCK) for the NRZ-L. The remainder of the circuitry is for converting the NRZ-L and BTCK into biphase data. The device was designed for use in the space shuttle bay environment measurements.

  6. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2002-01-01

    The field of digital avionics experienced another year of important advances in civil aviation, military systems, and space applications. As a result of the events of 9/11/2001, NASA has pursued activities to apply its aerospace technologies toward improved aviation security. Both NASA Glenn Research Center and Langley Research Center have performed flight research demonstrations using advanced datalink concepts to transmit live pictures from inside a jetliner, and to downlink the contents of the plane's 'black box' recorder in real time. The U.S. Navy and General Electric demonstrated survivable engine control (SEC) algorithms during engine ground tests at the Weapons Survivability Laboratory at China Lake. The scientists at Boeing Satellite Systems advanced the field of stellar inertial technology with the development of a new method for positioning optical star trackers on satellites.

  7. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2003-01-01

    Digital Avionics activities played an important role in the advancements made in civil aviation, military systems, and space applications. This document profiles advances made in each of these areas by the aerospace industry, NASA centers, and the U.S. military. Emerging communication technologies covered in this document include Internet connectivity onboard aircraft, wireless broadband communication for aircraft, and a mobile router for aircraft to communicate in multiple communication networks over the course of a flight. Military technologies covered in this document include avionics for unmanned combat air vehicles and microsatellites, and head-up displays. Other technologies covered in this document include an electronic flight bag for the Boeing 777, and surveillance systems for managing airport operations.

  8. Digital structural

    USGS Publications Warehouse

    Dohm, J.M.; Anderson, R.C.; Tanaka, K.L.

    1998-01-01

    Magmatic and tectonic activity have both contributed significantly to the surface geology of Mars. Digital structural mapping techniques have now been used to classify and date centers of tectonic activity in the western equatorial region. For example, our results show a center of tectonic activity at Valles Marineris, which may be associated with uplift caused by intrusion. Such evidence may help explain, in part, the development of the large troughs and associated outflow channels and chaotic terrain. We also find a local centre of tectonic activity near the source region of Warrego Valles. Here, we suggest that the valley system may have resulted largely from intrusive-related hydrothermal activity. We hope that this work, together with the current Mars Global Surveyor mission, will lead to a better understanding of the geological processes that shaped the Martian surface.

  9. Digital communication systems

    NASA Astrophysics Data System (ADS)

    Peebles, Peyton Z., Jr.

    The fundamental principles of digital communication and the design of practical digital communication systems are explored in an introductory textbook for senior and graduate students of electrical engineering. Chapters are devoted to sampling principles, baseband digital waveforms, baseband digital systems, bandpass binary digital systems, and M-ary digital systems. Deterministic signals, networks, and random-signal theory are reviewed in extensive appendices, and graphs, flow charts, diagrams, and problems are provided.

  10. Can We Teach Digital Natives Digital Literacy?

    ERIC Educational Resources Information Center

    Ng, Wan

    2012-01-01

    In recent years, there has been much debate about the concept of digital natives, in particular the differences between the digital natives' knowledge and adoption of digital technologies in informal versus formal educational contexts. This paper investigates the knowledge about educational technologies of a group of undergraduate students…

  11. Digital photorefraction

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F.; Jorge, Jorge M.

    1997-12-01

    The early evaluation of the visual status of human infants is of a critical importance. It is of utmost importance to the development of the child's visual system that she perceives clear, focused, retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur. Photorefraction is a non-invasive clinical tool rather convenient for application to this kind of population. A qualitative or semi-quantitative information about refractive errors, accommodation, strabismus, amblyogenic factors and some pathologies (cataracts) can the easily obtained. The photorefraction experimental setup we established using new technological breakthroughs on the fields of imaging devices, image processing and fiber optics, allows the implementation of both the isotropic and eccentric photorefraction approaches. Essentially both methods consist on delivering a light beam into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The system is formed by one CCD color camera and a light source. A beam splitter in front of the camera's objective allows coaxial illumination and observation. An optomechanical system also allows eccentric illumination. The light source is a flash type one and is synchronized with the camera's image acquisition. The camera's image is digitized displayed in real time. Image processing routines are applied for image's enhancement and feature extraction.

  12. Digital photorefraction

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.; Jorge, Jorge M.

    1998-01-01

    The early evaluation of the visual status of human infants is of a critical importance. It is of utmost importance to the development of the child's visual system that she perceives clear, focused, retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur. Photorefraction is a non-invasive clinical tool rather convenient for application to this kind of population. A qualitative or semi-quantitative information about refractive errors, accommodation, strabismus, amblyogenic factors and some pathologies (cataracts) can the easily obtained. The photorefraction experimental setup we established using new technological breakthroughs on the fields of imaging devices, image processing and fiber optics, allows the implementation of both the isotropic and eccentric photorefraction approaches. Essentially both methods consist on delivering a light beam into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The system is formed by one CCD color camera and a light source. A beam splitter in front of the camera's objective allows coaxial illumination and observation. An optomechanical system also allows eccentric illumination. The light source is a flash type one and is synchronized with the camera's image acquisition. The camera's image is digitized displayed in real time. Image processing routines are applied for image's enhancement and feature extraction.

  13. H. Sapiens Digital: From Digital Immigrants and Digital Natives to Digital Wisdom

    ERIC Educational Resources Information Center

    Prensky, Marc

    2009-01-01

    As we move further into the 21st century, the digital native/digital immigrant paradigm created by Marc Prensky in 2001 is becoming less relevant. In this article, Prensky suggests that we should focus instead on the development of what he calls "digital wisdom." Arguing that digital technology can make us not just smarter but truly wiser, Prensky…

  14. Digital Sensor Technology

    SciTech Connect

    Ted Quinn; Jerry Mauck; Richard Bockhorst; Ken Thomas

    2013-07-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy, reliability, availability, and maintainability. This report demonstrates these benefits in direct comparisons of digital and analog sensor applications. It also addresses the qualification issues that must be addressed in the application of digital sensor technology.

  15. Digital image processing.

    PubMed

    Seeram, Euclid

    2004-01-01

    Digital image processing is now commonplace in radiology, nuclear medicine and sonography. This article outlines underlying principles and concepts of digital image processing. After completing this article, readers should be able to: List the limitations of film-based imaging. Identify major components of a digital imaging system. Describe the history and application areas of digital image processing. Discuss image representation and the fundamentals of digital image processing. Outline digital image processing techniques and processing operations used in selected imaging modalities. Explain the basic concepts and visualization tools used in 3-D and virtual reality imaging. Recognize medical imaging informatics as a new area of specialization for radiologic technologists. PMID:15352557

  16. Bridging the Digital Divide

    ERIC Educational Resources Information Center

    Clarke, Alan; Milner, Helen; Killer, Terry; Dixon, Genny

    2008-01-01

    As the Government publishes its action plan for consultation on digital inclusion, the authors consider some of the challenges and opportunities for the delivery of digital inclusion. Clarke argues that digital inclusion requires more than access to technology or the skills to use it effectively, it demands information and media literacy. Milner…

  17. Digital Ink and Notetaking

    ERIC Educational Resources Information Center

    Colwell, Kenneth E.

    2004-01-01

    Tablet PCs and graphics tablets employ digital ink technology. In this paper the author introduces the reader to digital ink technology with the aim of promoting its use in various instructional or training settings, with the goal of improving instructor-learner dialogue and student learning. The potential of digital ink for improved instructional…

  18. Reconceptualising Critical Digital Literacy

    ERIC Educational Resources Information Center

    Pangrazio, Luciana

    2016-01-01

    While it has proved a useful concept during the past 20 years, the notion of "critical digital literacy" requires rethinking in light of the fast-changing nature of young people's digital practices. This paper contrasts long-established notions of "critical digital literacy" (based primarily around the critical consumption of…

  19. Digital Literacy. Research Brief

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2011-01-01

    21st Century students need a complex set of skills to be successful in a digital environment. Digital literacy, similar to traditional definitions of literacy, is a set of skills students use to locate, organize, understand, evaluate and create information. The difference is that it occurs in an environment where a growing set of digital tools…

  20. Digital Language Death

    PubMed Central

    Kornai, András

    2013-01-01

    Of the approximately 7,000 languages spoken today, some 2,500 are generally considered endangered. Here we argue that this consensus figure vastly underestimates the danger of digital language death, in that less than 5% of all languages can still ascend to the digital realm. We present evidence of a massive die-off caused by the digital divide. PMID:24167559

  1. Digital subtraction laryngography

    SciTech Connect

    Brown, B.W.; Enzmann, D.R.; Hopp, M.L.; Castellino, R.A.

    1983-06-01

    Digital subtraction laryngography was used to evaluate laryngeal function in 8 patients: 4 with normal larynxes and 4 with laryngeal disease. Subtracted digital images provided a dynamic display of the extent and symmetry of vocal cord excursions and pyriform sinus inflation, and the vocal cord resting position was also clearly depicted. The technical details of digital subtraction laryngography and its application are described.

  2. NEXUS: Digitizing Higher Education.

    ERIC Educational Resources Information Center

    Kirk, Camille

    2000-01-01

    Discussion of digital technology in the context of higher education planning considers how these technologies change teaching; the digital divide; the costs of information technology; hard wiring the campus; material consequences of information technology; digitally enabled crimes and misdemeanors; and libraries and scholarly publishing. Concludes…

  3. Mass Digitization of Books

    ERIC Educational Resources Information Center

    Coyle, Karen

    2006-01-01

    Mass digitization of the bound volumes that we generally call "books" has begun, and, thanks to the interest in Google and all that it does, it is getting widespread media attention. The Open Content Alliance (OCA), a library initiative formed after Google announced its library book digitization project, has brought library digitization projects…

  4. Digital language death.

    PubMed

    Kornai, András

    2013-01-01

    Of the approximately 7,000 languages spoken today, some 2,500 are generally considered endangered. Here we argue that this consensus figure vastly underestimates the danger of digital language death, in that less than 5% of all languages can still ascend to the digital realm. We present evidence of a massive die-off caused by the digital divide. PMID:24167559

  5. Digital Mammography and Digital Breast Tomosynthesis.

    PubMed

    Moseley, Tanya W

    2016-06-01

    Breast imaging technology has advanced significantly from the 1930s until the present. American women have a 1 in 8 chance of developing breast cancer. Mammography has been proven in multiple clinical trials to reduce breast cancer mortality. Although a mainstay of breast imaging and improved from film-screen mammography, digital mammography is not a perfect examination. Overlapping obscuring breast tissue limits mammographic interpretation. Breast digital tomosynthesis reduces and/or eliminates overlapping obscuring breast tissue. Although there are some disadvantages with digital breast tomosynthesis, this relatively lost-cost technology may be used effectively in the screening and diagnostic settings. PMID:27101241

  6. Digital rights management for digital cinema

    NASA Astrophysics Data System (ADS)

    Kirovski, Darko; Peinado, Marcus; Petitcolas, Fabien A. P.

    2001-12-01

    There is a wide consensus among the feature film production studios that the Internet era brings a new paradigm for film distribution to cinemas worldwide. The benefits of digital cinema to both producers and cinemas are numerous: significantly lower distribution and maintenance costs, immediate access to film libraries, higher presentation quality, and strong potential for developing new business models. Despite these advantages, the studios are still reluctant to jump into the digital age. The main showstopper for digital cinema is the danger of widespread piracy. Piracy already costs Hollywood an estimated two billion dollars annually and digital cinema without proper copyright enforcement could increase this number. In this paper, we present a copyright management system that aims at providing the set of necessary security tools: standard cryptographic primitives and copyright protection mechanisms that enable a reliable and secure feature film delivery system.

  7. Digital Collections, Digital Libraries and the Digitization of Cultural Heritage Information.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2002-01-01

    Discusses the development of digital collections and digital libraries. Topics include digitization of cultural heritage information; broadband issues; lack of compelling content; training issues; types of materials being digitized; sustainability; digital preservation; infrastructure; digital images; data mining; and future possibilities for…

  8. Digital radiography: an overview.

    PubMed

    Parks, Edwin T; Williamson, Gail F

    2002-11-15

    Since the discovery of X-rays in 1895, film has been the primary medium for capturing, displaying, and storing radiographic images. It is a technology that dental practitioners are the most familiar and comfortable with in terms of technique and interpretation. Digital radiography is the latest advancement in dental imaging and is slowly being adopted by the dental profession. Digital imaging incorporates computer technology in the capture, display, enhancement, and storage of direct radiographic images. Digital imaging offers some distinct advantages over film, but like any emerging technology, it presents new and different challenges for the practitioner to overcome. This article presents an overview of digital imaging including basic terminology and comparisons with film-based imaging. The principles of direct and indirect digital imaging modalities, intraoral and extraoral applications, image processing, and diagnostic efficacy will be discussed. In addition, the article will provide a list of questions dentists should consider prior to purchasing digital imaging systems for their practice. PMID:12444400

  9. Digital work-flow

    PubMed Central

    MARSANGO, V.; BOLLERO, R.; D’OVIDIO, N.; MIRANDA, M.; BOLLERO, P.; BARLATTANI, A.

    2014-01-01

    SUMMARY Objective. The project presents a clinical case in which the digital work-flow procedure was applied for a prosthetic rehabilitation in natural teeth and implants. Materials. Digital work-flow uses patient’s photo for the aesthetic’s planning, digital smile technology for the simulation of the final restoration and real time scanning to register the two arches. Than the scanning are sent to the laboratory that proceed with CAD-CAM production. Results. Digital work-flow offers the opportunities to easily speak with laboratory and patients, gives better clinical results and demonstrated to be a less invasiveness method for the patient. Conclusion. Intra-oral scanner, digital smile design, preview using digital wax-up, CAD-CAM production, are new predictable opportunities for prosthetic team. This work-flow, compared with traditional methods, is faster, more precise and predictable. PMID:25694797

  10. Digital Sensor Technology

    SciTech Connect

    Thomas, Ken D.; Quinn, Edward L.; Mauck, Jerry L.; Bockhorst, Richard M.

    2015-02-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy and reliability. This paper, which refers to a final report issued in 2013, demonstrates these benefits in direct comparisons of digital and analog sensor applications. Improved accuracy results from the superior operating characteristics of digital sensors. These include improvements in sensor accuracy and drift and other related parameters which reduce total loop uncertainty and thereby increase safety and operating margins. An example instrument loop uncertainty calculation for a pressure sensor application is presented to illustrate these improvements. This is a side-by-side comparison of the instrument loop uncertainty for both an analog and a digital sensor in the same pressure measurement application. Similarly, improved sensor reliability is illustrated with a sample calculation for determining the probability of failure on demand, an industry standard reliability measure. This looks at equivalent analog and digital temperature sensors to draw the comparison. The results confirm substantial reliability improvement with the digital sensor, due in large part to ability to continuously monitor the health of a digital sensor such that problems can be immediately identified and corrected. This greatly reduces the likelihood of a latent failure condition of the sensor at the time of a design basis event. Notwithstanding the benefits of digital sensors, there are certain qualification issues that are inherent with digital technology and these are described in the report. One major qualification impediment for digital sensor implementation is software common cause failure (SCCF).

  11. Digital Longitudinal Tomosynthesis

    NASA Astrophysics Data System (ADS)

    Rimkus, Daniel Steven

    1985-12-01

    The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed "tomosynthesis". A prototype system utilizing this technique was developed. Both phantom and patient studies were done with this system. The phantom studies were evaluated by subjective, visual criterion and by quantitative analysis of edge sharpness and noise in the reconstructions. Two groups of patients and one volunteer were studied. The first patient group consisted of 8 patients undergoing intravenous urography (IVU). These patients had digital tomography and film tomography of the abdomen. The second patient group consisted of 4 patients with lung cancer admitted to the hospital for laser resection of endobronchial tumor. These patients had mediastinal digital tomograms to evaluate the trachea and mainstem bronchi. The knee of one volunteer was imaged by film tomography and digital tomography. The results of the phantom studies showed that the digital reconstructions accurately produced images of the desired planes. The edge sharpness of the reconstructions approached that of the acquired images. Adequate reconstructions were achieved with as few as 5 images acquired during the exposure, with the quality of the reconstructions improving as the number of images acquired increased. The IVU patients' digital studies had less contrast and spatial resolution than the film tomograms. The single renal lesion visible on the film tomograms was also visible in the digital images. The digital mediastinal studies were felt by several radiologists to be superior to a standard chest xray in evaluating the airways. The digital images of the volunteer's knee showed many of the same anatomic features as the film tomogram, but the digital

  12. Debunking the "Digital Native": Beyond Digital Apartheid, towards Digital Democracy

    ERIC Educational Resources Information Center

    Brown, C.; Czerniewicz, L.

    2010-01-01

    This paper interrogates the currently pervasive discourse of the "net generation" finding the concept of the "digital native" especially problematic, both empirically and conceptually. We draw on a research project of South African higher education students' access to and use of Information and Communication Technologies (ICTs) to show that age is…

  13. Digital In, Digital Out: Digital Editing with Firewire.

    ERIC Educational Resources Information Center

    Doyle, Bob; Sauer, Jeff

    1997-01-01

    Reviews linear and nonlinear digital video (DV) editing equipment and software, using the IEEE 1394 (FireWire) connector. Includes a chart listing specifications and rating eight DV editing systems, reviews two DV still-photo cameras, and previews beta DV products. (PEN)

  14. Exploring digital professionalism.

    PubMed

    Ellaway, Rachel H; Coral, Janet; Topps, David; Topps, Maureen

    2015-01-01

    The widespread use of digital media (both computing devices and the services they access) has blurred the boundaries between our personal and professional lives. Contemporary students are the last to remember a time before the widespread use of the Internet and they will be the first to practice in a largely e-health environment. This article explores concepts of digital professionalism and their place in contemporary medical education, and proposes a series of principles of digital professionalism to guide teaching, learning and practice in the healthcare professions. Despite the many risks and fears surrounding their use, digital media are not an intrinsic threat to medical professionalism. Professionals should maintain the capacity for deliberate, ethical, and accountable practice when using digital media. The authors describe a digital professionalism framework structured around concepts of proficiency, reputation, and responsibility. Digital professionalism can be integrated into medical education using strategies based on awareness, alignment, assessment, and accountability. These principles of digital professionalism provide a way for medical students and medical practitioners to embrace the positive aspects of digital media use while being mindful and deliberate in its use to avoid or minimize any negative consequences. PMID:26030375

  15. Digital security technology simplified.

    PubMed

    Scaglione, Bernard J

    2007-01-01

    Digital security technology is making great strides in replacing analog and other traditional security systems including CCTV card access, personal identification and alarm monitoring applications. Like any new technology, the author says, it is important to understand its benefits and limitations before purchasing and installing, to ensure its proper operation and effectiveness. This article is a primer for security directors on how digital technology works. It provides an understanding of the key components which make up the foundation for digital security systems, focusing on three key aspects of the digital security world: the security network, IP cameras and IP recorders. PMID:17907609

  16. Digital solar system geology

    NASA Technical Reports Server (NTRS)

    Batson, R. M.; Kozak, R. C.; Isbell, Nancy K.

    1991-01-01

    All available synoptic maps of the solid-surface bodies of the Solar System were digitized for presentation in the planned Atlas of the Solar System by Greeley and Batson. Since the last report (Batson et al., 1990), preliminary Uranian satellite maps were replaced with improved versions, Galilean satellite geology was simplified and digitized, structure was added to many maps, and the maps were converted to a standard format, with corresponding standing colors for the mapped units. Following these changes, the maps were re-reviewed by their authors and are now undergoing final editing before preparation for publication. In some cases (for Mercury, Venus, and Mars), more detailed maps were digitized and then simplified for the Atlas. Other detailed maps are planned to be digitized in the coming year for the Moon and the Galilean satellites. For most of the remaining bodies such as the Uranian satellites, the current digitized versions contain virtually all the detail that can be mapped given the available data; those versions will be unchanged for the Atlas. These digital geologic maps are archived at the digital scale of 1/16 degree/ pixel, in sinusoidal format. The availability of geology of the Solar System in a digital database will facilitate comparisons and integration with other data: digitized lunar geologic maps have already been used in a comparison with Galileo SSI observations of the Moon.

  17. Experiments in digital literacy.

    PubMed

    Eshet-Alkali, Yoram; Amichai-Hamburger, Yair

    2004-08-01

    Having digital literacy requires more than just the ability to use software or to operate a digital device; it includes a large variety of complex skills such as cognitive, motoric, sociological, and emotional that users need to have in order to use digital environments effectively. A conceptual model that was recently described by the authors suggests that digital literacy comprises five major digital skills: photo-visual skills ("reading" instructions from graphical displays), reproduction skills (utilizing digital reproduction to create new, meaningful materials from preexisting ones), branching skills (constructing knowledge from non-linear, hypertextual navigation), information skills (evaluating the quality and validity of information), and socio-emotional skills (understanding the "rules" that prevail in cyberspace and applying this understanding in online cyberspace communication). The present paper presents results from a performance-based pioneer study that investigated the application of the above digital literacy skills conceptual model among different groups of scholars. Results clearly indicate that the younger participants performed better than the older ones, with photo-visual and branching literacy tasks, whereas the older participants were found to be more literate in reproduction and information literacy tasks. Research results shed light on the cognitive skills that users utilize in performing with digital environments, and provide educators and software developers with helpful guidelines for designing better user-centered digital environments. PMID:15331029

  18. Digitization Best Practices

    SciTech Connect

    Xue, Fei; Holtkamp, Irma S.; Knudson, Frances L.

    2012-07-31

    This project involved performing tests and documenting results to determine best practices for digitizing older print documents. The digitization process is complicated, especially when original documents exhibit non-standard fonts and are faded. Tests focused on solutions to improve high quality scanning, increase OCR accuracy, and efficiently use embedded metadata. Results are summarized. From the test results on the right sides, we know that when we plan to digitize documents, we should balance Quantity and Quality based on our expectation, and then make final decision for the digitization process.

  19. Digital rights language support for evolving digital cinema requirements

    NASA Astrophysics Data System (ADS)

    Orri, Xavier; Mas, Joan-Maria; Macq, Benoit M. M.

    2003-06-01

    Digital cinema can be defined as the digital electronic distribution and display of theatrical film content or live material to the theatre. However, this simple definition does not reflect the complex mesh of balanced business relationships between the different parties involved in the worldwide cinematic distribution. Its transition from an analogue to a digital business will happen progressively, starting with only content being digitally distributed and going until an all-digital business. From these facts derive strong requirements on digital rights management (DRM) systems for digital cinema and therefore on the digital rights language supporting it. This paper explores the requirements imposed by the cinematic distribution model and by its progressive transition to digital, and the impact these have on digital rights languages. We analyze the support provided by different digital rights languages, identifying weaknesses and exploring solutions in fulfilling the requirements of the digital cinema distribution model.

  20. ISDN: The Digital Difference.

    ERIC Educational Resources Information Center

    Piedmo, Greg

    1995-01-01

    Integrated services digital network (ISDN) is a dial-up digital transmission service supporting transmission of audio, video, and text data over standard copper telephone wires or fiber optic cables. Advantages of ISDN over analog transmission include the ability of one phone line to support up to three simultaneous, separate conversations (phone,…

  1. Cresting the Digital Divide

    ERIC Educational Resources Information Center

    Gregory, Kay; Steelman, Joyce

    2008-01-01

    Catawba Valley Community College has introduced digital storytelling (DS), an innovative instructional method that has produced extraordinary results. Digital storytelling uses affordable software to craft powerful multimedia presentations of student writing. Students create 3-to-4-minute movies with images, voiceovers, and music. This project…

  2. Digital Video Editing

    ERIC Educational Resources Information Center

    McConnell, Terry

    2004-01-01

    Monica Adams, head librarian at Robinson Secondary in Fairfax country, Virginia, states that librarians should have the technical knowledge to support projects related to digital video editing. The process of digital video editing and the cables, storage issues and the computer system with software is described.

  3. Will Digital Texts Succeed?

    ERIC Educational Resources Information Center

    Acker, Stephen R.

    2008-01-01

    With faculty changing instructional practices to take advantage of customizable, focused content (and digital delivery of that content), many people assume that digital distribution is the answer to bringing the costs of course content delivery in line. But the picture just isn't that simple. A wide continuum of options is available to faculty and…

  4. Shaping Digital Library Content.

    ERIC Educational Resources Information Center

    Miller, Rush G.

    2002-01-01

    Explores issues related to the selection and purchase of digital content in academic libraries, including commercially-produced databases, electronic journals, and books and other electronic resources that are purchased from vendors; and in-house digitization projects. Considers the degree to which standard collection management principles apply.…

  5. Optimization of digital designs

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)

    2009-01-01

    An application specific integrated circuit is optimized by translating a first representation of its digital design to a second representation. The second representation includes multiple syntactic expressions that admit a representation of a higher-order function of base Boolean values. The syntactic expressions are manipulated to form a third representation of the digital design.

  6. Music Instruction Goes Digital

    ERIC Educational Resources Information Center

    Demski, Jennifer

    2011-01-01

    Faced with meager enrollment in band, orchestra, and choir programs, schools are using digital technology to excite students about creating music on today's terms. This article discusses how music educators reinvent their profession by acknowledging and incorporating the way students interact with music today--digitally. Bill Evans, a music…

  7. Digital Image Access & Retrieval.

    ERIC Educational Resources Information Center

    Heidorn, P. Bryan, Ed.; Sandore, Beth, Ed.

    Recent technological advances in computing and digital imaging technology have had immediate and permanent consequences for visual resource collections. Libraries are involved in organizing and managing large visual resource collections. The central challenges in working with digital image collections mirror those that libraries have sought to…

  8. Creating Digital Authors

    ERIC Educational Resources Information Center

    Zoch, Melody; Langston-DeMott, Brooke; Adams-Budde, Melissa

    2014-01-01

    Elementary students find themselves engaged and learning at a digital writing camp. The authors find that such elementary students usually have limited access to technology at home and school, and posit that teachers should do all they can to give them more access to and experience in digital composing. Students were motivated and learned to use…

  9. Writing and Digital Media

    ERIC Educational Resources Information Center

    van Waes, Luuk, Ed.; Leijten, Marielle, Ed.; Neuwirth, Chris, Ed.

    2006-01-01

    Digital media has become an increasingly powerful force in modern society. This volume brings together outstanding European, American and Australian research in "writing and digital media" and explores its cognitive, social and cultural implications. In addition to presenting programs of original research by internationally known scholars from a…

  10. Digital Signature Management.

    ERIC Educational Resources Information Center

    Hassler, Vesna; Biely, Helmut

    1999-01-01

    Describes the Digital Signature Project that was developed in Austria to establish an infrastructure for applying smart card-based digital signatures in banking and electronic-commerce applications. Discusses the need to conform to international standards, an international certification infrastructure, and security features for a public directory…

  11. Digital Knowledge Resources

    ERIC Educational Resources Information Center

    Pandian, M. Paul

    2008-01-01

    Technology has revolutionized the concept of libraries. Networking and computing technologies have now become sufficiently advanced to support the design and deployment of large digital libraries which are capable of supporting the conventional end-user functions. Digital libraries are a natural extension of the evolution in which libraries have…

  12. Taming the Digital Beast

    ERIC Educational Resources Information Center

    Patrizio, Andy

    2006-01-01

    As more and more schools move to digital repositories, it seems inevitable that the knowledge accumulated across universities will go digital. How smoothly an institution makes that transition will depend on how well its project is planned from inception, and how well it structure its data. All of the administrators and educators the authors spoke…

  13. The Digital Absurd

    ERIC Educational Resources Information Center

    Hodges, Steve

    2010-01-01

    I believe that the concept of the absurd, as described in philosophy and reflected in works of drama and literature, provides an unusual and helpful perspective from which to view the emerging field of digital media. In my opinion, absurd principles can help us understand the mixed feelings we may have when engaging with digital media: joy and…

  14. Navigate the Digital Rapids

    ERIC Educational Resources Information Center

    Lindsay, Julie; Davis, Vicki

    2010-01-01

    How can teachers teach digital citizenship when the digital landscape is changing so rapidly? How can teachers teach proper online social interactions when the students are outside their classroom and thus outside their control? Will encouraging students to engage in global collaborative environments land teachers in hot water? These are the…

  15. Educating Digital Citizens

    ERIC Educational Resources Information Center

    Tan, Thomas

    2011-01-01

    Digital citizenship is how educators, citizens, and parents can teach where the lines of cyber safety and ethics are in the interconnected online world their students will inhabit. Aside from keeping technology users safe, digital citizenship also prepares students to survive and thrive in an environment embedded with information, communication,…

  16. Digital Media and Learning

    ERIC Educational Resources Information Center

    John D. and Catherine T. MacArthur Foundation, 2012

    2012-01-01

    MacArthur launched the digital media and learning initiative in 2006 to explore how digital media are changing the way young people learn, socialize, communicate, and play. Since 2006, the Foundation has awarded grants totaling more than $100 million for research, development of innovative new technologies, new learning environments for youth,…

  17. Digital automatic gain control

    NASA Technical Reports Server (NTRS)

    Uzdy, Z.

    1980-01-01

    Performance analysis, used to evaluated fitness of several circuits to digital automatic gain control (AGC), indicates that digital integrator employing coherent amplitude detector (CAD) is best device suited for application. Circuit reduces gain error to half that of conventional analog AGC while making it possible to automatically modify response of receiver to match incoming signal conditions.

  18. Digital rotation measurement unit

    DOEpatents

    Sanderson, S.N.

    1983-09-30

    A digital rotation indicator is disclosed for monitoring the position of a valve member having a movable actuator. The indicator utilizes mercury switches adapted to move in cooperation with the actuator. Each of the switches produces an output as it changes state when the actuator moves. A direction detection circuit is connected to the switches to produce a first digital signal indicative of the direction of rotation of the actuator. A count pulse generating circuit is also connected to the switches to produce a second digital pulse signal having count pulses corresponding to a change of state of any of the mercury switches. A reset pulse generating circuit is provided to generate a reset pulse each time a count pulse is generated. An up/down counter is connected to receive the first digital pulse signal and the second digital pulse signal and to count the pulses of the second digital pulse signal either up or down depending upon the instantaneous digital value of the first digital signal whereby a running count indicative of the movement of the actuator is maintained.

  19. Occupying the Digital Humanities

    ERIC Educational Resources Information Center

    Rice, Jeff

    2013-01-01

    This essay questions the digital humanities' dependence on interpretation and critique as strategies for reading and responding to texts. Instead, the essay proposes suggestion as a digital rhetorical practice, one that does not replace hermeneutics, but instead offers alternative ways to respond to texts. The essay uses the Occupy movement as an…

  20. The Digital Vaults

    ERIC Educational Resources Information Center

    Isaacs, Suzanne; Potter, Lee Ann

    2008-01-01

    This article explores the Digital Vaults and offers suggestions in introducing this site to students. The Digital Vaults, inspired by the permanent Public Vaults exhibition launched by the National Archives in 2004, is not just another website, but it designed to be an online exhibit and teaching tool, by offering both exposure to historical…

  1. Digital Pinhole Camera

    ERIC Educational Resources Information Center

    Lancor, Rachael; Lancor, Brian

    2014-01-01

    In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

  2. Digital Collections Inventory Report.

    ERIC Educational Resources Information Center

    McClung, Patricia A.

    This report is intended to inform and stimulate discussion on digital library programs as well as the potential usefulness, scope, and desired features of future inventories of online digital collections. It describes a joint project by the Commission on Preservation and Access and the Council on Library Resources to determine the extent to which…

  3. Digital communications study

    NASA Technical Reports Server (NTRS)

    Boorstyn, R. R.

    1973-01-01

    Research is reported dealing with problems of digital data transmission and computer communications networks. The results of four individual studies are presented which include: (1) signal processing with finite state machines, (2) signal parameter estimation from discrete-time observations, (3) digital filtering for radar signal processing applications, and (4) multiple server queues where all servers are not identical.

  4. Changing State Digital Libraries

    ERIC Educational Resources Information Center

    Pappas, Marjorie L.

    2006-01-01

    Research has shown that state virtual or digital libraries are evolving into websites that are loaded with free resources, subscription databases, and instructional tools. In this article, the author explores these evolving libraries based on the following questions: (1) How user-friendly are the state digital libraries?; (2) How do state digital…

  5. Fundamentals of Digital Logic.

    ERIC Educational Resources Information Center

    Noell, Monica L.

    This course is designed to prepare electronics personnel for further training in digital techniques, presenting need to know information that is basic to any maintenance course on digital equipment. It consists of seven study units: (1) binary arithmetic; (2) boolean algebra; (3) logic gates; (4) logic flip-flops; (5) nonlogic circuits; (6)…

  6. Scholars | Digital Representation | Publishing

    ERIC Educational Resources Information Center

    Hodgson, Justin

    2014-01-01

    Understanding the current state of digital publishing means that writers can now do more and say more in more ways than ever before in human history. As modes, methods, media and mechanisms of expression mutate into newer and newer digital forms, writers find themselves at a moment when they can create, critique collaborate, and comment according…

  7. Towards a Digital Future

    ERIC Educational Resources Information Center

    Thomson, Rachel

    2009-01-01

    A month ago, a French court ruled that internet access is a basic human right. Gordon Brown has said it is as crucial for people as electricity and water. Yet, 17 million Britons are still excluded from digital technology and an estimated 13 per cent of the population--some six million people--are both socially and digitally excluded. There are…

  8. Parallel digital forensics infrastructure.

    SciTech Connect

    Liebrock, Lorie M.; Duggan, David Patrick

    2009-10-01

    This report documents the architecture and implementation of a Parallel Digital Forensics infrastructure. This infrastructure is necessary for supporting the design, implementation, and testing of new classes of parallel digital forensics tools. Digital Forensics has become extremely difficult with data sets of one terabyte and larger. The only way to overcome the processing time of these large sets is to identify and develop new parallel algorithms for performing the analysis. To support algorithm research, a flexible base infrastructure is required. A candidate architecture for this base infrastructure was designed, instantiated, and tested by this project, in collaboration with New Mexico Tech. Previous infrastructures were not designed and built specifically for the development and testing of parallel algorithms. With the size of forensics data sets only expected to increase significantly, this type of infrastructure support is necessary for continued research in parallel digital forensics. This report documents the implementation of the parallel digital forensics (PDF) infrastructure architecture and implementation.

  9. Digital biology and chemistry.

    PubMed

    Witters, Daan; Sun, Bing; Begolo, Stefano; Rodriguez-Manzano, Jesus; Robles, Whitney; Ismagilov, Rustem F

    2014-09-01

    This account examines developments in "digital" biology and chemistry within the context of microfluidics, from a personal perspective. Using microfluidics as a frame of reference, we identify two areas of research within digital biology and chemistry that are of special interest: (i) the study of systems that switch between discrete states in response to changes in chemical concentration of signals, and (ii) the study of single biological entities such as molecules or cells. In particular, microfluidics accelerates analysis of switching systems (i.e., those that exhibit a sharp change in output over a narrow range of input) by enabling monitoring of multiple reactions in parallel over a range of concentrations of signals. Conversely, such switching systems can be used to create new kinds of microfluidic detection systems that provide "analog-to-digital" signal conversion and logic. Microfluidic compartmentalization technologies for studying and isolating single entities can be used to reconstruct and understand cellular processes, study interactions between single biological entities, and examine the intrinsic heterogeneity of populations of molecules, cells, or organisms. Furthermore, compartmentalization of single cells or molecules in "digital" microfluidic experiments can induce switching in a range of reaction systems to enable sensitive detection of cells or biomolecules, such as with digital ELISA or digital PCR. This "digitizing" offers advantages in terms of robustness, assay design, and simplicity because quantitative information can be obtained with qualitative measurements. While digital formats have been shown to improve the robustness of existing chemistries, we anticipate that in the future they will enable new chemistries to be used for quantitative measurements, and that digital biology and chemistry will continue to provide further opportunities for measuring biomolecules, understanding natural systems more deeply, and advancing molecular and

  10. Computing Logarithms Digit-by-Digit

    ERIC Educational Resources Information Center

    Goldberg, Mayer

    2005-01-01

    In this work, we present an algorithm for computing logarithms of positive real numbers, that bears structural resemblance to the elementary school algorithm of long division. Using this algorithm, we can compute successive digits of a logarithm using a 4-operation pocket calculator. The algorithm makes no use of Taylor series or calculus, but…

  11. Digital Booktalk: Digital Media for Reluctant Readers

    ERIC Educational Resources Information Center

    Gunter, Glenda; Kenny, Robert

    2008-01-01

    New learning and communications paradigms of today's learners are extending the definition of literacy and directly affecting how reading and writing skills are acquired (Leu, 2000). Mirroring an ever-expanding definition of literacy, new college and K-12 curricular programs that redefine digital media are popping up all over the country. Story is…

  12. From Digital Divide to Digital Democracy.

    ERIC Educational Resources Information Center

    de los Santos, Gerardo E., Ed.; de los Santos, Alfredo G., Jr., Ed.; Milliron, Mark David, Ed.

    This publication is one of many efforts of the League for Innovation in the Community College to address the issue of societal technology access and learning needs. This work addresses the issue of the digital divide, which includes the often conflicting perspectives of information technology (IT) access and literacy needs held by government…

  13. The Digital Carrot, the Digital Stick

    ERIC Educational Resources Information Center

    Jackson, Gregory A.

    2007-01-01

    In this article, the author asserts that technology is not the answer to digital piracy at colleges and universities. Citing the three most common explanations given for copyright infringement--that students cannot always get what they want, cannot always use what they can get, or think the price of what they can get is unfair--he asserts that the…

  14. Digital sonar system

    SciTech Connect

    Young, K.K.; Wilkes, R.J.

    1995-11-21

    A transponder of an active digital sonar system identifies a multifrequency underwater activating sonar signal received from a remote sonar transmitter. The transponder includes a transducer that receives acoustic waves, including the activating sonar signal, and generates an analog electrical receipt signal. The analog electrical receipt signal is converted to a digital receipt signal and cross-correlated with a digital transmission signal pattern corresponding to the activating sonar signal. A relative peak in the cross-correlation value is indicative of the activating sonar signal having been received by the transponder. In response to identifying the activating sonar signal, the transponder transmits a responding multifrequency sonar signal. 4 figs.

  15. Digital sonar system

    SciTech Connect

    Young, Kenneth K.; Wilkes, R. Jeffrey

    1995-01-01

    A transponder of an active digital sonar system identifies a multifrequency underwater activating sonar signal received from a remote sonar transmitter. The transponder includes a transducer that receives acoustic waves, including the activating sonar signal, and generates an analog electrical receipt signal. The analog electrical receipt signal is converted to a digital receipt signal and cross-correlated with a digital transmission signal pattern corresponding to the activating sonar signal. A relative peak in the cross-correlation value is indicative of the activating sonar signal having been received by the transponder. In response to identifying the activating sonar signal, the transponder transmits a responding multifrequency sonar signal.

  16. Fast transient digitizer

    SciTech Connect

    Villa, F.

    1981-07-08

    Method and apparatus are presented for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display.

  17. Digital Citizenship Means Character Education for the Digital Age

    ERIC Educational Resources Information Center

    Ohler, Jason

    2011-01-01

    The reality of students' cyber lives has thrust upon educators a new approach: creating character education programs tuned to digital youth that are both proactive and aggressive. Taking this approach will help integrate students' digital activities within the context of the communities in which they live, both local and digital. The digital age…

  18. Digital Citizenship Means Character Education for the Digital Age

    ERIC Educational Resources Information Center

    Ohler, Jason

    2012-01-01

    The reality of students' cyber lives has thrust upon educators a new approach: creating character education programs tuned to digital youth that are proactive and aggressive. This will help integrate students' digital activities within the context of the communities in which they live, both local and digital. The digital age beckons a new era of…

  19. Digital Library and Digital Reference Service: Integration and Mutual Complementarity

    ERIC Educational Resources Information Center

    Liu, Jia

    2008-01-01

    Both the digital library and the digital reference service were invented and have been developed under the networked environment. Among their intersections, the fundamental thing is their symbiotic interest--serving the user in a more efficient way. The article starts by discussing the digital library and its service and the digital reference…

  20. First Digit Law and Its Application to Digital Forensics

    NASA Astrophysics Data System (ADS)

    Shi, Yun Q.

    Digital data forensics, which gathers evidence of data composition, origin, and history, is crucial in our digital world. Although this new research field is still in its infancy stage, it has started to attract increasing attention from the multimedia-security research community. This lecture addresses the first digit law and its applications to digital forensics. First, the Benford and generalized Benford laws, referred to as first digit law, are introduced. Then, the application of first digit law to detection of JPEG compression history for a given BMP image and detection of double JPEG compressions are presented. Finally, applying first digit law to detection of double MPEG video compressions is discussed. It is expected that the first digit law may play an active role in other task of digital forensics. The lesson learned is that statistical models play an important role in digital forensics and for a specific forensic task different models may provide different performance.

  1. Implantable digital hearing aid

    NASA Technical Reports Server (NTRS)

    Kissiah, A. M., Jr.

    1979-01-01

    Hearing aid converts analog output of microphone into digital pulses in about 10 channels of audiofrequencies. Each pulse band could be directly connected to portion of auditory nerve most sensitive to that range.

  2. Preservation of Digital Objects.

    ERIC Educational Resources Information Center

    Galloway, Patricia

    2004-01-01

    Presents a literature review that covers the following topics related to preservation of digital objects: practical examples; stakeholders; recordkeeping standards; genre-specific problems; trusted repository standards; preservation methods; preservation metadata standards; and future directions. (Contains 82 references.) (MES)

  3. Replantation of digits

    MedlinePlus

    Risks of this surgery include: Reactions to medications Problems breathing Bleeding Infection Death of the replanted tissue Reduced nerve function or movement in the replanted digit Stiffness of the ...

  4. Digital ac monitor

    DOEpatents

    Hart, George W.; Kern, Jr., Edward C.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

  5. Forecasting digital microcircuit obsolescence

    NASA Astrophysics Data System (ADS)

    Balwally, Nandakumar M.

    1991-03-01

    This report documents a procedure for forecasting digital microcircuit obsolescence at the Defense Electronics Supply Center, Dayton, OH. Obsolescence is caused by rapid advancement in digital technology and decrease in commercial demand while military demand still continues. In logistics parlance, parts obsolescence is known as a diminishing manufacturing source (DMS) problem. Continued supply of an obsolete DMS item is assured via substitution, alternate sourcing or a one time buy equal to the lifetime requirements of the item. Emulation is a recent alternative which explores the possibility of replacing obsolete digital microcircuits with state of the art devices which can be manufactured and supplied on demand. The report recommends use of a statistical model which forecasts DMS items from a population of presently non-DMS items belonging to obsolete digital microcircuit technologies. The items forecast by the model should be evaluated for their emulation potential.

  6. Survey of digital filtering

    NASA Technical Reports Server (NTRS)

    Nagle, H. T., Jr.

    1972-01-01

    A three part survey is made of the state-of-the-art in digital filtering. Part one presents background material including sampled data transformations and the discrete Fourier transform. Part two, digital filter theory, gives an in-depth coverage of filter categories, transfer function synthesis, quantization and other nonlinear errors, filter structures and computer aided design. Part three presents hardware mechanization techniques. Implementations by general purpose, mini-, and special-purpose computers are presented.

  7. Digital Image Velocimetry

    NASA Technical Reports Server (NTRS)

    Cho, Y. C.

    1991-01-01

    Proposed technique for production of velocity maps from sequences of photographic video images of flows seeded with small particles. In digital image velocimetry, image analyzed by digital Fourier tranformation. Process free of noise, more precise, and consumes less time. Eliminates need to process photographs, indicates directions of velocity vectors unambiguously, and offers increased dynamic ranges. Because all processing performed electronically, eventually capable of mapping flow-velocity fields in real time.

  8. Sloan digital sky survey

    SciTech Connect

    Kent, S.M.; Stoughton, C.; Newberg, H.; Loveday, J.; Petravick, D.; Gurbani, V.; Berman, E.; Sergey, G.; Lupton, R.

    1994-04-01

    The Sloan Digital Sky Survey will produce a detailed digital photometric map of half the northern sky to about 23 magnitude using a special purpose wide field 2.5 meter telescope. From this map we will select {approximately} 10{sup 6} galaxies and 10{sup 5} quasars, and obtain high resolution spectra using the same telescope. The imaging catalog will contain 10{sup 8} galaxies, a similar number of stars, and 10{sup 6} quasar candidates.

  9. Digital tomosynthesis: technique.

    PubMed

    Yaffe, Martin J; Mainprize, James G

    2014-05-01

    Digital breast tomosynthesis is an extension of digital mammography that produces quasi three-dimensional reconstructed images from a set of low-dose x-ray projections acquired over a limited angular range. The quality of the reconstructed image and the dose to the breast are dependent on the angular range and number of projections, the dose used per projection, and detector resolution and noise characteristics. This article discusses various aspects of tomosynthesis optimization. PMID:24792651

  10. Dental digital radiography.

    PubMed

    Moore, William S

    2002-05-01

    Digital images offer tremendous advantages to dentistry in terms of the potential for lower exposure to patients, absence of darkroom or processing problems, convenience of image enhancement techniques and capacity for remote teledentistry. Digital systems are now able to acquire all types of images including panoramic and cephalometric. As technology continues to improve they may ultimately replace film as the medium of choice for dental imaging. PMID:12046403

  11. Digital and analog communication systems

    NASA Technical Reports Server (NTRS)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  12. Escaping the Digital Dark Age.

    ERIC Educational Resources Information Center

    Brand, Stewart

    1999-01-01

    Discusses the loss of stored knowledge due to the continuous obsolescence of digital formats and platforms. Topics include digital storage versus digital preservation; the use of metadata and efforts to create standards for it; information on the Internet; and the need for long-term planning to solve digital degradation. (LRW)

  13. Digitization of photographic collections

    NASA Astrophysics Data System (ADS)

    Frey, Franziska S.

    1997-04-01

    Almost every major institution is contemplating some kind of digital-imaging project, but sources of information and experience are few. Technical aspects of digital imaging present libraries and archives with very difficult and complex choices. There are as yet no codified technical standards for image capture, display, and output, all of which affect the image quality, the cost, and, ultimately, the success or failure of the entire undertaking. Even if a vendor will provide a finished 'turnkey' system, an institution must understand the nature of the digital- imaging product they are buying. They must know how much image quality and functionality can be expected from it, both now and in the future. New tools must be provided for collection managers to make that possible. Beyond these purely technical issues, institutions must be able to relate the digital-image database system to the fundamental collection activities of access and preservation. Despite all the possibilities for manipulating digital images, image quality choices made when files are first created have the same 'finality' that they have in conventional photography. They will have a profound effect on project cost and the value of the final project to the users. Image quality requirements therefore have to be established carefully before a digitization project starts.

  14. Digital Imaging in Cytopathology

    PubMed Central

    Khalbuss, Walid E.; Pantanowitz, Liron; Parwani, Anil V.

    2011-01-01

    Rapid advances are occurring in the field of cytopathology, particularly in the field of digital imaging. Today, digital images are used in a variety of settings including education (E-education), as a substitute to multiheaded sessions, multisite conferences, publications, cytopathology web pages, cytology proficiency testing, telecytology, consultation through telecytology, and automated screening of Pap test slides. The accessibility provided by digital imaging in cytopathology can improve the quality and efficiency of cytopathology services, primarily by getting the expert cytopathologist to remotely look at the slide. This improved accessibility saves time and alleviates the need to ship slides, wait for glass slides, or transport pathologists. Whole slide imaging (WSI) is a digital imaging modality that uses computerized technology to scan and convert pathology and cytology glass slides into digital images (digital slides) that can be viewed remotely on a workstation using viewing software. In spite of the many advances, challenges remain such as the expensive initial set-up costs, workflow interruption, length of time to scan whole slides, large storage size for WSI, bandwidth restrictions, undefined legal implications, professional reluctance, and lack of standardization in the imaging process. PMID:21785680

  15. Digital Elevation Models

    USGS Publications Warehouse

    U.S. Geological Survey

    1993-01-01

    The Earth Science Information Center (ESIC) distributes digital cartographic/geographic data files produced by the U.S. Geological Survey (USGS) as part of the National Mapping Program. Digital cartographic data files may be grouped into four basic types. The first of these, called a Digital Line Graph (DLG), is the line map information in digital form. These data files include information on base data categories, such as transportation, hypsography, hydrography, and boundaries. The second type, called a Digital Elevation Model (DEM), consists of a sampled array of elevations for a number of ground positions at regularly spaced intervals. The third type is Land Use and Land Cover digital data which provides information on nine major classes of land use such as urban, agricultural, or forest as well as associated map data such as political units and Federal land ownership. The fourth type, the Geographic Names Information System, provides primary information for all known places, features, and areas in the United States identified by a proper name.

  16. Digital holography display (3)

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Zheng, Huadong; Chia, Yong Poo; Cheng, Chee Yuen; Yu, Yang; Yu, Yingjie; Asundi, Anand

    2013-06-01

    This paper is to describe a color digital holographic projector and this system is comprised of RGB lasers, 3 units of Digital Micro-Mirror Device (DMD) and high speed rotating diffuser. In this research, we focused on colorings Digital holograms and synchronized RGB digital holograms versus rotated diffuser. To achieve this phenomenon, three of the holograms optical path need to be aligned to pass through a same beam splitter and eventually combined as one colored holograms output While, this colored hologram will be reconstructed on volumetric screen (rotated diffuser) at the floating manner in free space. To obtain these result 3 key factors is investigated: 1. To configured 1 master and 2 slaves digital micro mirror illumination time 2. To reconstructed holograms orientation angle diffuser versus rotating speed. 3. To synchronize rotating diffuser speed versus DMD frame-rate Last but not least, the team built a prototype Color Digital Holography Display but more developments are required to follow up such as, enhance system's reliability, robustness, compactness and 3D realistic images floating in the free air space.

  17. From Digital Divides to Digital Inequality -- The Emerging Digital Inequality in the Norwegian Unitarian School

    ERIC Educational Resources Information Center

    Krumsvik, Rune J.

    2008-01-01

    This position paper highlights existing and emerging, prospective digital divides in Norwegian schools and asks whether we are now moving from traditional digital divides to digital inequality in our digitized society and schools. Despite very good technology density in Norwegian society and schools in general, there is the reason to pay attention…

  18. Digital field ion microscopy

    SciTech Connect

    Sijbrandij, S.J.; Russell, K.F.; Miller, M.K.; Thomson, R.C.

    1998-01-01

    Due to environmental concerns, there is a trend to avoid the use of chemicals needed to develop negatives and to process photographic paper, and to use digital technologies instead. Digital technology also offers the advantages that it is convenient, as it enables quick access to the end result, allows image storage and processing on computer, allows rapid hard copy output, and simplifies electronic publishing. Recently significant improvements have been made to the performance and cost of camera-sensors and printers. In this paper, field ion images recorded with two digital cameras of different resolution are compared to images recorded on standard 35 mm negative film. It should be noted that field ion images exhibit low light intensity and high contrast. Field ion images were recorded from a standard microchannel plate and a phosphor screen and had acceptance angles of {approximately} 60{degree}. Digital recordings were made with a Digital Vision Technologies (DVT) MICAM VHR1000 camera with a resolution of 752 x 582 pixels, and a Kodak DCS 460 digital camera with a resolution of 3,060 x 2,036 pixels. Film based recordings were made with Kodak T-MAX film rated at 400 ASA. The resolving power of T-MAX film, as specified by Kodak, is between 50 and 125 lines per mm, which corresponds to between 1,778 x 1,181 and 4,445 x 2,953 pixels, i.e. similar to that from the DCS 460 camera. The intensities of the images were sufficient to be recorded with standard fl:1.2 lenses with exposure times of less than 2 s. Many digital cameras were excluded from these experiments due to their lack of sensitivity or the inability to record a full frame image due to the fixed working distance defined by the vacuum system. The digital images were output on a Kodak Digital Science 8650 PS dye sublimation color printer (300 dpi). All field ion micrographs presented were obtained from a Ni-Al-Be specimen.

  19. Digital Actuator Technology

    SciTech Connect

    Ken Thomas; Ted Quinn; Jerry Mauck; Richard Bockhorst

    2014-09-01

    There are significant developments underway in new types of actuators for power plant active components. Many of these make use of digital technology to provide a wide array of benefits in performance of the actuators and in reduced burden to maintain them. These new product offerings have gained considerable acceptance in use in process plants. In addition, they have been used in conventional power generation very successfully. This technology has been proven to deliver the benefits promised and substantiate the claims of improved performance. The nuclear industry has been reluctant to incorporate digital actuator technology into nuclear plant designs due to concerns due to a number of concerns. These could be summarized as cost, regulatory uncertainty, and a certain comfort factor with legacy analog technology. The replacement opportunity for these types of components represents a decision point for whether to invest in more modern technology that would provide superior operational and maintenance benefits. Yet, the application of digital technology has been problematic for the nuclear industry, due to qualification and regulatory issues. With some notable exceptions, the result has been a continuing reluctance to undertake the risks and uncertainties of implementing digital actuator technology when replacement opportunities present themselves. Rather, utilities would typically prefer to accept the performance limitations of the legacy analog actuator technologies to avoid impacts to project costs and schedules. The purpose of this report is to demonstrate that the benefits of digital actuator technology can be significant in terms of plant performance and that it is worthwhile to address the barriers currently holding back the widespread development and use of this technology. It addresses two important objectives in pursuit of the beneficial use of digital actuator technology for nuclear power plants: 1. To demonstrate the benefits of digital actuator

  20. Digital imaging in dentistry.

    PubMed

    Essen, S Donovan

    2011-01-01

    Information technology is vital to operations, marketing, accounting, finance and administration. One of the most exciting and quickly evolving technologies in the modern dental office is digital applications. The dentist is often the business manager, information technology officer and strategic planning chief for his small business. The information systems triangle applies directly to this critical manager supported by properly trained ancillary staff and good equipment. With emerging technology driving all medical disciplines and the rapid pace at which it emerges, it is vital for the contemporary practitioner to keep abreast of the newest information technology developments. This article compares the strategic and operational advantages of digital applications, specifically imaging. The focus of this paper will be on digital radiography (DR), 3D computerized tomography, digital photography and digitally-driven CAD/CAM to what are now considered obsolescing modalities and contemplates what may arrive in the future. It is the purpose of this essay to succinctly evaluate the decisions involved in the role, application and implications of employing this tool in the dental environment PMID:22132658

  1. Mars digital terrain model

    NASA Technical Reports Server (NTRS)

    Wu, Sherman S. C.; Howington, Annie-Elpis

    1987-01-01

    The Mars Digital Terrain Model (DTM) is the result of a new project to: (1) digitize the series of 1:2,000,000-scale topographic maps of Mars, which are being derived photogrammetically under a separate project, and (2) reformat the digital contour information into rasters of elevation that can be readily registered with the Digital Image Model (DIM) of Mars. Derivation of DTM's involves interpolation of elevation values into 1/64-degree resolution and transformation of them to a sinusoidal equal-area projection. Digital data are produced in blocks corresponding with the coordinates of the original 1:2,000,000-scale maps, i.e., the dimensions of each block in the equatorial belt are 22.5 deg of longitude and 15 deg of latitude. This DTM is not only compatible with the DIM, but it can also be registered with other data such as geologic units or gravity. It will be the most comprehensive record of topographic information yet compiled for the Martian surface. Once the DTM's are established, any enhancement of Mars topographic information made with updated data, such as data from the planned Mars Observer Mission, will be by mathematical transformation of the DTM's, eliminating the need for recompilation.

  2. Digital cinema video compression

    NASA Astrophysics Data System (ADS)

    Husak, Walter

    2003-05-01

    The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.

  3. Compensated digital readout family

    NASA Technical Reports Server (NTRS)

    Ludwig, David E.; Skow, Michael

    1991-01-01

    ISC has completed test on an IC which has 32 channels of amplifiers, low pass anti-aliasing filters, 13-bit analog-to-digital (A/D) converters with non-uniformity correction per channel and a digital multiplexer. The single slope class of A/D conversion is described, as are the unique variations required for incorporation of this technique for use with on-focal plane detector readout electronics. This paper describes the architecture used to implement the digital on-focal plane signal processing functions. Results from measured data on a test IC are presented for a circuit containing these functions operating at a sensor frame rate of 1000 hertz.

  4. Digital signal coding

    SciTech Connect

    Gaunt, R.

    1997-05-01

    It seems that digital video has gone by as many names as Jim Blinn has Siggraph ribbons. Some of its various formats and names are: DV, Dl, 4:2:2, CCIR 601-1, ITU-Rec. 601-4,, SMPTE RP125M, and SMPTE 259M. CCIR and CCITT were both absorbed into their parent organization, the International Telecommunications Union (ITU), so technically speaking, CCIR 601 has been renamed to ITU-Rec. 601-4 (``Rec.`` stands for recommendation). But convention is often hard to change, so for some time you will see and hear Dl and CCIR 601 used for serial digital component video. Below are brief descriptions of the various names and formats for digital video.

  5. Interactive digital signal processor

    NASA Technical Reports Server (NTRS)

    Mish, W. H.; Wenger, R. M.; Behannon, K. W.; Byrnes, J. B.

    1982-01-01

    The Interactive Digital Signal Processor (IDSP) is examined. It consists of a set of time series analysis Operators each of which operates on an input file to produce an output file. The operators can be executed in any order that makes sense and recursively, if desired. The operators are the various algorithms used in digital time series analysis work. User written operators can be easily interfaced to the sysatem. The system can be operated both interactively and in batch mode. In IDSP a file can consist of up to n (currently n=8) simultaneous time series. IDSP currently includes over thirty standard operators that range from Fourier transform operations, design and application of digital filters, eigenvalue analysis, to operators that provide graphical output, allow batch operation, editing and display information.

  6. Digital optical conversion module

    DOEpatents

    Kotter, Dale K.; Rankin, Richard A.

    1991-02-26

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer.

  7. Digital optical conversion module

    DOEpatents

    Kotter, D.K.; Rankin, R.A.

    1988-07-19

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer. 2 figs.

  8. Photon counting digital holography

    NASA Astrophysics Data System (ADS)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario; Pavičić, Mladen

    2016-05-01

    Digital holography uses electronic sensors for hologram recording and numerical method for hologram reconstruction enabling thus the development of advanced holography applications. However, in some cases, the useful information is concealed in a very wide dynamic range of illumination intensities and successful recording requires an appropriate dynamic range of the sensor. An effective solution to this problem is the use of a photon-counting detector. Such detectors possess counting rates of the order of tens to hundreds of millions counts per second, but conditions of recording holograms have to be investigated in greater detail. Here, we summarize our main findings on this problem. First, conditions for optimum recording of digital holograms for detecting a signal significantly below detector's noise are analyzed in terms of the most important holographic measures. Second, for time-averaged digital holograms, optimum recordings were investigated for exposures shorter than the vibration cycle. In both cases, these conditions are studied by simulations and experiments.

  9. Precision digital control systems

    NASA Astrophysics Data System (ADS)

    Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

    This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

  10. Digital optical conversion module

    NASA Astrophysics Data System (ADS)

    Kotter, Dale K.; Rankin, Richard A.

    1988-07-01

    A digital optical conversion module is used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer.

  11. Digital Optical Circuit Technology

    NASA Technical Reports Server (NTRS)

    Dove, B. L. (Editor)

    1985-01-01

    The Proceedings for the 48th Meeting of the AGARD Avionics Panel contain the 18 papers presented a Technical Evaluation Report, and discussions that followed the presentations of papers. Seven papers were presented in the session devoted to optical bistability. Optical logic was addressed by three papers. The session on sources, modulators and demodulators presented three papers. Five papers were given in the final session on all optical systems. The purpose of this Specialists' Meeting was to present the research and development status of digital optical circuit technology and to examine its relevance in the broad context of digital processing, communication, radar, avionics and flight control systems implementation.

  12. Managing digital images.

    PubMed

    Swartz, M L

    2000-09-01

    Although most orthodontists can rely on their orthodontic image software, those who have the need to go beyond just the monitor display of the images will need to get behind the scenes. Understanding a little of what makes up digital images and how to manipulate the variables will enable them to get optimum image quality as well as conserve on time, file size, and storage media. For those who import bitmapped images into digital presentations, the ability to adjust these variables can enable them to create presentation files that are manageable in size, will display without delays, and are of optimum resolution. PMID:10982939

  13. DYI digital holography

    NASA Astrophysics Data System (ADS)

    Zacharovas, Stanislovas; Nikolskij, Andrej; Kuchin, Jevgenij

    2011-02-01

    We have created a programming tool which uses image data provided by webcam connected to personal computer and gives user an ability to see the future digital hologram preview on his computer screen, before sending video data to holographic printing companies. In order to print digital hologram, one needs to have a sequence of images of the same scene taken from different angles and nowadays web cameras - stand-alone or incorporated into mobile computer, can be an acceptable source of such image sequences. In this article we are describing this DIY holographic imaging process in details.

  14. Digital wireless control system

    NASA Astrophysics Data System (ADS)

    Smith, R.

    1993-08-01

    The Digital Wireless Control System (DWCS) is designed to initiate high explosives safely while using a wireless remote control system. Numerous safety features have been designed into the fire control system to mitigate the hazards associated with remote initiation of high explosives. These safety features range from a telemetry (TM) fire control status system to mechanical timers and keyed power lockout switches. The environment, safety, and health (ES&H) Standard Operating Procedure (SOP) SP471970 is intended as a guide when working with the DWCS. This report describes the Digital Wireless Control System and outlines each component's theory of operation and its relationship to the system.

  15. Digital satellite communications

    NASA Astrophysics Data System (ADS)

    Ha, T. T.

    1986-06-01

    The use of satellite communications in point-to-multipoint transmission of data is studied. The theory, systems, and equipment for satellite communications are described. The topics of satellite orbits, satellite construction, earth station equipment, and the analysis of the satellite link are discussed. Different types of digital modulation for carrier transmission, and techniques for enhancing the transmission capacity, such as digital speech interpolation and demand assignment, are examined. Techniques and equipment for performing the multiple access-broadcasting functions including FDMA, TDMA, DAMA, CDMA, and random access are considered.

  16. Digital Image Correlation Engine

    SciTech Connect

    Turner, Dan; Crozier, Paul; Reu, Phil

    2015-10-06

    DICe is an open source digital image correlation (DIC) tool intended for use as a module in an external application or as a standalone analysis code. It's primary capability is computing full –field displacements and strains from sequences of digital These images are typically of a material sample undergoing a materials characterization experiment, but DICe is also useful for other applications (for example, trajectory tracking). DICe is machine portable (Windows, Linux and Mac) and can be effectively deployed on a high performance computing platform. Capabilities from DICe can be invoked through a library interface, via source code integration of DICe classes or through a graphical user interface.

  17. Digital cartography of Mars

    NASA Technical Reports Server (NTRS)

    Batson, R. M.

    1987-01-01

    A medium-resolution Digital Image Model (DIM) of Mars is being compiled. A DIM is a mosaic of radiometrically corrected, photometrically modelled spacecraft images displaying accurate reflectance properties at uniform resolution, and geometrically tied to the best available control. The Mars medium-resolution DIM contains approximately 4700 Viking Orbiter image frames that were used to compile the recently completed 1:2,000,000-scale controlled photomosaic series of Mars. This DIM provides a planimetric control base to which all other Mars maps will be registered. A similar control base of topographic elevations (Digital Terrain Model, or DTM) is also being compiled. These products are scheduled for completion in 1989.

  18. Digital DICOM in Dentistry

    PubMed Central

    Burgess, Jeff

    2015-01-01

    Similar to Medicine, digital communication, information processing, and x-ray imaging have changed the face of dentistry. The incorporation of digital systems into medical and dental practice has necessitated development of a standard that allows reliable transmission of information between the devices taking the images, devices storing the images, and devices displaying the images. This standard is termed as DICOM. The following article briefly reviews how DICOM came about, how dentistry is involved, the various elements that are part of the DICOM system, and how DICOM is currently used in dentistry. PMID:26464603

  19. Digital Preservation in Open-Source Digital Library Software

    ERIC Educational Resources Information Center

    Madalli, Devika P.; Barve, Sunita; Amin, Saiful

    2012-01-01

    Digital archives and digital library projects are being initiated all over the world for materials of different formats and domains. To organize, store, and retrieve digital content, many libraries as well as archiving centers are using either proprietary or open-source software. While it is accepted that print media can survive for centuries with…

  20. Digital Preservation: A Time Bomb for Digital Libraries.

    ERIC Educational Resources Information Center

    Hedstrom, Margaret

    1998-01-01

    Argues that the difficulty and expense of preserving digital information is a potential impediment to digital library development. Discusses the present state of digital preservation, articulates requirements for users and custodians, and suggests research topics in storage media, migration, conversion, and overall management strategies. (DSK)

  1. Digital Natives and Digital Immigrants: Teaching with Technology

    ERIC Educational Resources Information Center

    Martin, Ellen Marie Peterson

    2011-01-01

    Education is witnessing an increasing demand for technology use in the classroom. At the same time, new teachers are entering the profession in high numbers, some being labeled as "Digital Natives" while others are labeled "Digital Immigrants". This qualitative case study investigated the technology practices of Digital Native and Digital…

  2. Digital Storytelling as an Interactive Digital Media Context

    ERIC Educational Resources Information Center

    Anderson, Kate T.; Chua, Puay Hoe

    2010-01-01

    Digital storytelling involves the creation of short, personal narratives combining images, sounds, and text in a multimedia computer-based platform. In education, digital storytelling has been used to foster learning in formal and informal spaces worldwide. The authors offer a critical discussion of claims about digital storytelling's usefulness…

  3. FORTRAN IV Digital Filter Design Programs. Digital Systems Education Project.

    ERIC Educational Resources Information Center

    Reuss, E.; And Others

    The goals of the Digital Systems Education Project (DISE) include the development and distribution of educational/instructional materials in the digital systems area. Toward that end, this document contains three reports: (1) A FORTRAN IV Design Program for Low-Pass Butterworth and Chebychev Digital Filters; (2) A FORTRAN IV Design Program for…

  4. Artifacts in Digital Collections.

    ERIC Educational Resources Information Center

    Nichols, Stephen G.

    This paper discusses the preservation of digital resources in research libraries. The first section addresses the preservation imperative, including the challenges of quantity, stability of media, economics, and the contingent value of artifacts. The second section describes the artifact in question (i.e., an information resource in which the…

  5. DIGITAL LINE GRAPHS - USGS

    EPA Science Inventory

    USGS DLGs are digital representations of program-quadrangle format and sectional maps. All DLG data distributed by the United States Geological Survey (USGS) are DLG-Level 3 (DLG-3), which means the data contain a full range of attribute codes, have full topological structuring, ...

  6. The New Digital Awareness

    ERIC Educational Resources Information Center

    Bohle, Shannon

    2008-01-01

    With all the new advances in library technology--including metadata, social networking, and Web 2.0, along with the advent of nonlibrary and for-profit digital information companies like Wikisource and Google Print--librarians have barely had time to reflect on the nontechnical implications of these innovations. They need to take a step back and…

  7. Live, Digital Reference.

    ERIC Educational Resources Information Center

    Kenney, Brian

    2002-01-01

    Discusses digital reference services, also known as virtual reference, chat reference, or online reference, based on a round table discussion at the 2002 American Library Association annual conference in Atlanta. Topics include numbers and marketing; sustainability; competition and models; evaluation methods; outsourcing; staffing and training;…

  8. Books Born Digital

    ERIC Educational Resources Information Center

    Eaton, Lance

    2009-01-01

    It used to be that a book was published first as a hardcover, then as a lower-cost paperback. With increasingly tech-savvy consumers demanding instantaneous access to content in various formats, that publishing protocol has in the last decade changed to one in which the book in codex form often remains the focus, but digital "extras" like audio…

  9. Sensors feel digital pressure

    SciTech Connect

    Ham, J.

    1996-05-01

    Anyone who has connected a field instrument to an analog input card for a DCS, PLC or PC-based data acquisition or control system has faced the issue of analog-to-digital (A/D) conversion. Signal conversion always involves compromises in accuracy and speed. Digital communication with fieldbus eliminates the problem, right? Not exactly; fieldbus may simply move the A/D interface from the control room to the field. The vast majority of measuring instruments have analog sensors with signals that must be converted to strings of bits somewhere, somehow. Instrument manufacturers must embrace digital technology in sensor design, not just in transmitter design. One way to address the issue is to use microsystems technology, such as microelectro-mechanical systems (MEMS). Research at Delft University of Technology in the Netherlands, for example, is aimed at fabricating devices in silicon with all the components of a data-acquisition unit integrated on one chip. These smart sensors would host the sensor itself along with signal conditioning and A/D conversion circuits, and circuits for digital interfacing with a data processor. A/D conversion is still there, but encapsulated within and characterized as part of the sensor. Single-chip integration allows more signal processing within a manageable-sized package. Also, eliminating transmission of the analog signal, even within an instrument, reduces the chance for noise pickup. Less noise means instrument accuracy closer to actual sensor accuracy. 2 figs.

  10. Subminiature micropower digital recorder

    NASA Technical Reports Server (NTRS)

    Goodman, R. M.; Pitman, R. W.

    1973-01-01

    High-density digital data, collected periodically or randomly from multiplicity of sensors, are recorded by subminiature recorder. Magnetic recording head is energized with suitable pulsatile signals to reverse polarization on magnetically-sensitive tape while tape is immobilized at recording head. Prior to next recording, set tape so new area of tape is at recording head.

  11. Digitally Marking RSA Moduli

    SciTech Connect

    Johnston, A.M.

    2000-10-09

    The moduli used in RSA (see [5]) can be generated by many different sources. The generator of that modulus (assuming a single entity generates the modulus) knows its factorization. They would have the ability to forge signatures or break any system based on this moduli. If a moduli and the RSA parameters associated with it were generated by a reputable source, the system would have higher value than if the parameters were generated by an unknown entity. So for tracking, security, confidence and financial reasons it would be beneficial to know who the generator of the RSA modulus was. This is where digital marking comes in. An RSA modulus ia digitally marked, or digitally trade marked, if the generator and other identifying features of the modulus (such as its intended user, the version number, etc.) can be identified and possibly verified by the modulus itself. The basic concept of digitally marking an RSA modulus would be to fix the upper bits of the modulus to this tag. Thus anyone who sees the public modulus can tell who generated the modulus and who the generator believes the intended user/owner of the modulus is.

  12. Play and Digital Media

    ERIC Educational Resources Information Center

    Johnson, James E.; Christie, James F.

    2009-01-01

    This article examines how play is affected by computers and digital toys. Research indicates that when computer software targeted at children is problem-solving oriented and open-ended, children tend to engage in creative play and interact with peers in a positive manner. On the other hand, drill-and-practice programs can be quite boring and limit…

  13. Digital systems design language

    NASA Technical Reports Server (NTRS)

    Shiva, S. G.

    1979-01-01

    Digital Systems Design Language (DDL) is implemented on the SEL-32 Computer Systems. The detaileds of the language, the translator, and the simulator, and the smulator programs are given. Several example descriptions and a tutorial on hardware description languages are provided, to guide the user.

  14. Using Digital Microscopy

    ERIC Educational Resources Information Center

    Travaille, Madelaine; Adams, Sandra D.

    2006-01-01

    Studying "Caenorhabditis elegans" ("C. elegans") live cultures provides excellent opportunities for authentic inquiry in a high school anatomy and physiology or other biology lab course. Using a digital dissection microscope, a student can photograph the organism during various stages of development and study and analyze the images. In this…

  15. Digital Textbooks. Research Brief

    ERIC Educational Resources Information Center

    Johnston, Howard

    2011-01-01

    Despite their growing popularity, digital alternatives to conventional textbooks are stirring up controversy. With the introduction of tablet computers, and the growing trend toward "cloud computing" and "open source" software, the trend is accelerating because costs are coming down and free or inexpensive materials are becoming more available.…

  16. Learning and Digital Portfolios

    ERIC Educational Resources Information Center

    Moran, Wendy; Vozzo, Les; Reid, Jo-Anne; Pietsch, Marilyn; Hatton, Caroline

    2013-01-01

    Utilising appropriate Information Communication Technologies (ICT) as instructional tools in teacher education can be a challenging yet worthwhile endeavour. This paper reports the difficulties and benefits of a recent inter-university project requiring preservice primary teachers to construct professional digital portfolios using the support of…

  17. Ethics Go Digital

    ERIC Educational Resources Information Center

    Seager, Thomas P.; Selinger, Evan

    2012-01-01

    To be truly innovative, digital pedagogy has to do a better job of giving students the very thing that makes brick-and-mortar schooling so special: It must foster immersive learning communities that connect students to both their instructors and each other. Fortunately, there are ways that online education can do just that, as the authors have…

  18. Counting digital filters

    NASA Technical Reports Server (NTRS)

    Zohar, S. (Inventor)

    1973-01-01

    Several embodiments of a counting digital filter of the non-recursive type are disclosed. In each embodiment two registers, at least one of which is a shift register, are included. The shift register received j sub x-bit data input words bit by bit. The kth data word is represented by the integer.

  19. Check-Digit Schemes.

    ERIC Educational Resources Information Center

    Wheeler, Mary L.

    1994-01-01

    Discusses the study of identification codes and check-digit schemes as a way to show students a practical application of mathematics and introduce them to coding theory. Examples include postal service money orders, parcel tracking numbers, ISBN codes, bank identification numbers, and UPC codes. (MKR)

  20. Rethinking the Digital Divide.

    ERIC Educational Resources Information Center

    Light, Jennifer S.

    2001-01-01

    Compares the digital divide debate to debates over access to cable in the 1960s-1970s and demonstrates how access to technology is constructed as a social problem. Concludes that the current debate is different because it accepts the premise of technological determinism and assumes that closing the gap will mitigate broader social inequities.…

  1. Central Dogma Goes Digital.

    PubMed

    Lin, Yihan; Elowitz, Michael B

    2016-03-17

    In this issue of Molecular Cell, Tay and colleagues (Albayrak et al., 2016) describe a new technique to digitally quantify the numbers of protein and mRNA in the same mammalian cell, providing a new way to look at the central dogma of molecular biology. PMID:26990983

  2. ELECTRONIC DIGITAL COMPUTER

    DOEpatents

    Stone, J.J. Jr.; Bettis, E.S.; Mann, E.R.

    1957-10-01

    The electronic digital computer is designed to solve systems involving a plurality of simultaneous linear equations. The computer can solve a system which converges rather rapidly when using Von Seidel's method of approximation and performs the summations required for solving for the unknown terms by a method of successive approximations.

  3. Literature Circles Go Digital

    ERIC Educational Resources Information Center

    Bromley, Karen; Faughnan, Michelle; Ham, Susan; Miller, Melissa; Armstrong, Traci; Crandall, Cassandra; Garrison, Julia; Marrone, Nicholas

    2014-01-01

    This article describes a literature circle of seven pre-service teacher education students who read "Al Capone Shines My Shoes" (G. Choldenko, 2009). Students used the Internet to complete their roles, shared what they learned as they discussed the book, and then wrote about the digital experience. Four themes emerged from an analysis of…

  4. Digitizing Some Keywords.

    ERIC Educational Resources Information Center

    Lanham, Richard A.

    1989-01-01

    Traces the early history of the electronic digital computer and the viewpoints held concerning the computer from its inception to its present status. Highlights three key words ("mimesis,""topic," and "decorum") to develop the rhetoricality of the personal computer as a communications device. (KEH)

  5. Digital Projectors Demystified

    ERIC Educational Resources Information Center

    Careless, James

    2007-01-01

    Digital projectors are becoming a common sight in U.S. schools. A projector can serve many roles, from letting teachers give tours of educational Web sites to having students present their projects to the entire class. With this trend come questions: Which projection technology is the most cost-effective? Which requires the least maintenance? How…

  6. Digital Badges in Education

    ERIC Educational Resources Information Center

    Gibson, David; Ostashewski, Nathaniel; Flintoff, Kim; Grant, Sheryl; Knight, Erin

    2015-01-01

    Digital badges provide new affordances for online educational activities and experiences. When used with points and leaderboards, a badge can become a gamification element allowing learners to compete with themselves or others, and to know how close they are to accomplishing a goal and acquiring its accompanying reputation. In this role, badges…

  7. Digital capacitance measuring system

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The hardware phase of a digital capacitance measuring system is presented with the major emphasis placed on the electrical design and operation. Test results are included of the three units fabricated. The system's interface is applicable to existing requirements for the space shuttle vehicle.

  8. The Digital Divide

    ERIC Educational Resources Information Center

    Hudson, Hannah Trierweiler

    2011-01-01

    Megan is a 14-year-old from Nebraska who just started ninth grade. She has her own digital camera, cell phone, Nintendo DS, and laptop, and one or more of these devices is usually by her side. Compared to the interactions and exploration she's engaged in at home, Megan finds the technology in her classroom falls a little flat. Most of the…

  9. Complex Digital Visual Systems

    ERIC Educational Resources Information Center

    Sweeny, Robert W.

    2013-01-01

    This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…

  10. Evaluating Digital Authoring Tools

    ERIC Educational Resources Information Center

    Wilde, Russ

    2004-01-01

    As the quality of authoring software increases, online course developers become less reliant on proprietary learning management systems, and develop skills in the design of original, in-house materials and the delivery platforms for them. This report examines the capabilities of digital authoring software tools for the development of learning…

  11. Digital microarray analysis for digital artifact genomics

    NASA Astrophysics Data System (ADS)

    Jaenisch, Holger; Handley, James; Williams, Deborah

    2013-06-01

    We implement a Spatial Voting (SV) based analogy of microarray analysis for digital gene marker identification in malware code sections. We examine a famous set of malware formally analyzed by Mandiant and code named Advanced Persistent Threat (APT1). APT1 is a Chinese organization formed with specific intent to infiltrate and exploit US resources. Manidant provided a detailed behavior and sting analysis report for the 288 malware samples available. We performed an independent analysis using a new alternative to the traditional dynamic analysis and static analysis we call Spatial Analysis (SA). We perform unsupervised SA on the APT1 originating malware code sections and report our findings. We also show the results of SA performed on some members of the families associated by Manidant. We conclude that SV based SA is a practical fast alternative to dynamics analysis and static analysis.

  12. Digital can help with care.

    PubMed

    2016-05-27

    Welcome to the June issue of Nursing Older People. This month, Deidre Wild and colleagues ask the digital question in the second part of their article on digital skills training in care homes ( page 31 ). PMID:27231059

  13. Database Technology in Digital Libraries.

    ERIC Educational Resources Information Center

    Preston, Carole; Lin, Binshan

    2002-01-01

    Reviews issues relating to database technology and digital libraries. Highlights include resource sharing; ongoing digital library projects; metadata; user interfaces; query processing; interoperability; data quality; copyright infringement; and managerial implications, including electronic versus printed materials, accessibility,…

  14. Digital correlator with fewer IC's

    NASA Technical Reports Server (NTRS)

    Apple, G. G.; Rubin, L.

    1979-01-01

    Digital correlator requires only few integrated circuits to determine synchronization of two 24-bit digital words. Circuit is easily reduced or expanded to accommodate shorter or longer words and can be utilized in industrial and commercial data processing and telecommunications.

  15. The Intelsat digital communication systems

    NASA Astrophysics Data System (ADS)

    Phiel, John F., Jr.

    1990-08-01

    Intelsat international communication services resulting from the application of digital technology are summarized. Approximately 40 percent of the 140,000 terrestrial channels from the Public Switched Telephone Networks (PSTN) provided by the Intelsat network are now handled by digital systems. Digital technology for the interconnection of the PSTNs is discussed. Particular attention is paid to modulation and access techniques including the intermediate data rate (IDR) system, and the fixed and satellite switched TDMA systems. Digital compression techniques used with TDMA and IDR, such as digital speech interpolation and digital circuit multiplication, are also discussed. The Intelsat Business Service and the Intelnet Service are described in the framework of digital technology for private networks and business users. Communications for remote areas, international television services, and future opportunities through digital technologies are briefly presented.

  16. Digitally Controlled Beam Attenuator

    NASA Astrophysics Data System (ADS)

    Peppler, W. W.; Kudva, B.; Dobbins, J. T.; Lee, C. S.; Van Lysel, M. S.; Hasegawa, B. H.; Mistretta, C. A.

    1982-12-01

    In digital fluorographic techniques the video camera must accommodate a wide dynamic range due to the large variation in the subject thickness within the field of view. Typically exposure factors and the optical aperture are selected such that the maximum video signal is obtained in the most transmissive region of the subject. Consequently, it has been shown that the signal-to-noise ratio is severely reduced in the dark regions. We have developed a prototype digital beam attenuator (DBA) which will alleviate this and some related problems in digital fluorography. The prototype DBA consists of a 6x6 array of pistons which are individually controlled. A membrane containing an attenuating solu-tion of (CeC13) in water and the piston matrix are placed between the x-ray tube and the subject. Under digital control the pistons are moved into the attenuating material in order to adjust the beam intensity over each of the 36 cells. The DBA control unit which digitizes the image during patient positioning will direct the pistons under hydraulic control to produce a uniform x-ray field exiting the subject. The pistons were designed to produce very little structural background in the image. In subtraction studies any structure would be cancelled. For non-subtraction studies such as cine-cardiology we are considering higher cell densities (eg. 64x64). Due to the narrow range of transmission provided by the DBA, in such studies ultra-high contrast films could be used to produce a high resolution quasi-subtraction display. Additional benefits of the DBA are: 1) reduced dose to the bright image areas when the dark areas are properly exposed. 2) improved scatter and glare to primary ratios, leading to improved contrast in the dark areas.

  17. Crossing the Digital Divide

    SciTech Connect

    Ken Thomas

    2011-11-01

    Nuclear utilities continue to upgrade aging instrumentation and control (I&C) systems with modern digital-based systems to address reliability and obsolescence concerns. In addition, the industry has demonstrated that these systems can be successfully developed and deployed even for highly safety-significant applications, such as reactor protection. However, three factors have retarded wide-scale implementation of digital technology for plant modernization and business innovation: *Large-scale digital upgrades entail considerable risk; *The upgrades are very costly and have not led to bottom-line business improvement, financial or otherwise; *Cyber Security concerns discourage wide-scale digital integration. A new national research program is under way that has been designed to address these industry concerns about expanding the use of digital technology. The Idaho National Laboratory (INL) has lead responsibility for the Advanced Instrumentation, Information, and Control Systems Technologies research pathway within the Light Water Reactor Sustainability (LWRS) Program. The LWRS Program is a research and development (R&D) program sponsored by the U.S. Department of Energy (DOE) and performed in close collaboration with industry R&D and improvement programs (as defined in INL’s FY2009–2013 Light Water Reactor Sustainability Research and Development Program Plan, INL/MIS08-14918). Its purpose is to provide the technical foundations for licensing and managing the long-term, safe, and economical operation of existing nuclear power plants. The DOE’s program focus is on longer-term and higher-risk/reward research that contributes to the national policy objectives of energy security and environmental security. The specific concern addressed by this program is that large-scale I&C obsolescence could become a life-limiting issue for the current nuclear operating fleet.

  18. Analog and digital signal processing

    NASA Astrophysics Data System (ADS)

    Baher, H.

    The techniques of signal processing in both the analog and digital domains are addressed in a fashion suitable for undergraduate courses in modern electrical engineering. The topics considered include: spectral analysis of continuous and discrete signals, analysis of continuous and discrete systems and networks using transform methods, design of analog and digital filters, digitization of analog signals, power spectrum estimation of stochastic signals, FFT algorithms, finite word-length effects in digital signal processes, linear estimation, and adaptive filtering.

  19. Jitter in digital transmission systems

    NASA Astrophysics Data System (ADS)

    Trischitta, Patrick R.; Varma, Eve L.

    Theoretical, design, and applications aspects of jitter in digital telecommunication systems are discussed, with an emphasis on fiber-optic systems. Chapters are devoted to jitter introduced by line regenerators, jitter accumulation in cascaded regenerators, the effect of jitter on transmission quality, jitter introduced by digital multiplexes, jitter tolerance and transfer in digital multiplexes, jitter accumulation in digital networks, wander, and network jitter standards. Diagrams; graphs; and a glossary of symbols, acronyms, and abbreviations are provided.

  20. The World of Digital Storytelling

    ERIC Educational Resources Information Center

    Ohler, Jason

    2006-01-01

    Ohler describes the practice of making a digital story, which he defines as a brief narrative usually told in first person, combining writing with digital images and sound, and presented as a short movie. The art of digital storytelling, he asserts, enhances the teaching power of storytelling by teaching students valuable technical skills,…

  1. Developing Students' Professional Digital Identity

    ERIC Educational Resources Information Center

    Cochrane, Thomas; Antonczak, Laurent

    2015-01-01

    In contrast to the myth of the "Digital Native" and the ubiquity of Facebook use, we have found that students' digital identities are predominantly social with their online activity beyond Facebook limited to being social media consumers rather than producers. Within a global economy students need to learn new digital literacy skills to…

  2. Digital synchronization and communication techniques

    NASA Technical Reports Server (NTRS)

    Lindsey, William C.

    1992-01-01

    Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

  3. Design Language for Digital Systems

    NASA Technical Reports Server (NTRS)

    Shiva, S. G.

    1985-01-01

    Digital Systems Design Language (DDL) is convenient hardware description language for developing and testing digital designs and for inputting design details into design automation system. Describes digital systems at gate, register transfer, and combinational block levels. DDL-based programs written in FORTRAN IV for batch execution.

  4. Digital Equity and Intercultural Education

    ERIC Educational Resources Information Center

    Resta, Paul; Laferrière, Thérèse

    2015-01-01

    Digital equity and intercultural education continue to be areas of concern in the emerging knowledge-based society. The digital divide is present across the globe as the result of a complex of factors such as the inequality in: access to hardware and connectivity; autonomy of use; digital and literacy skills; availability of technical and social…

  5. JCE Digital Library Grand Opening

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 2004

    2004-01-01

    The National Science, Technology, Engineering and Mathematical Education Digital Library (NSDL), inaugurated in December 2002, is developed to promote science education on a comprehensive scale. The Journal of Chemical, Education (JCE) Digital Library, incorporated into NSDL, contains its own collections of digital resources for chemistry…

  6. Answering Your Digital Imaging Questions.

    ERIC Educational Resources Information Center

    Koelling, Jill Marie

    1998-01-01

    Discusses two reasons why institutions should create digital image files--access and preservation. Suggests a collection survey for determining what to scan. Describes the five most important technical issues of digital imaging: resolution, file formats, storage, refreshment, and copyright. Discusses digitization of manuscript collections and…

  7. Making Connections with Digital Data

    ERIC Educational Resources Information Center

    Leonard, William; Bassett, Rick; Clinger, Alicia; Edmondson, Elizabeth; Horton, Robert

    2004-01-01

    State-of-the-art digital cameras open up enormous possibilities in the science classroom, especially when used as data collectors. Because most high school students are not fully formal thinkers, the digital camera can provide a much richer learning experience than traditional observation. Data taken through digital images can make the…

  8. Digital Receiver Phase Meter

    NASA Technical Reports Server (NTRS)

    Marcin, Martin; Abramovici, Alexander

    2008-01-01

    The software of a commercially available digital radio receiver has been modified to make the receiver function as a two-channel low-noise phase meter. This phase meter is a prototype in the continuing development of a phase meter for a system in which radiofrequency (RF) signals in the two channels would be outputs of a spaceborne heterodyne laser interferometer for detecting gravitational waves. The frequencies of the signals could include a common Doppler-shift component of as much as 15 MHz. The phase meter is required to measure the relative phases of the signals in the two channels at a sampling rate of 10 Hz at a root power spectral density <5 microcycle/(Hz)1/2 and to be capable of determining the power spectral density of the phase difference over the frequency range from 1 mHz to 1 Hz. Such a phase meter could also be used on Earth to perform similar measurements in laser metrology of moving bodies. To illustrate part of the principle of operation of the phase meter, the figure includes a simplified block diagram of a basic singlechannel digital receiver. The input RF signal is first fed to the input terminal of an analog-to-digital converter (ADC). To prevent aliasing errors in the ADC, the sampling rate must be at least twice the input signal frequency. The sampling rate of the ADC is governed by a sampling clock, which also drives a digital local oscillator (DLO), which is a direct digital frequency synthesizer. The DLO produces samples of sine and cosine signals at a programmed tuning frequency. The sine and cosine samples are mixed with (that is, multiplied by) the samples from the ADC, then low-pass filtered to obtain in-phase (I) and quadrature (Q) signal components. A digital signal processor (DSP) computes the ratio between the Q and I components, computes the phase of the RF signal (relative to that of the DLO signal) as the arctangent of this ratio, and then averages successive such phase values over a time interval specified by the user.

  9. Digital processing of bandpass signals

    NASA Astrophysics Data System (ADS)

    Jackson, M. C.; Matthewson, P.

    Modern radar and radio systems rely on digital signal processing to enhance the quality of received signals. Prior to such processing, these signals must be converted to digital form. The historical development of signal digitization is briefly discussed in this paper and leads to a description of some current work on digital mixing. A method of directly sampling a band-limited intermediate frequency (i.f.) signal is presented, using a pair of digital mixer channels to produce complex low-pass samples of the signal envelope. The method is found to produce well matched channel outputs. Finally, the applicability of the method to radar is discussed.

  10. Teaching Students to Think in the Digital Environment: Digital Literacy and Digital Inquiry

    ERIC Educational Resources Information Center

    Stripling, Barbara

    2010-01-01

    The digital world, much like any new or changing environment, demands an assessment of the situation and development of new ways of thinking or working. School librarians must, therefore, partner with other educators to identify and teach the digital literacy and inquiry skills that will enable all students to be effective digital learners.…

  11. Neutron Detector Waveform Digitization

    NASA Astrophysics Data System (ADS)

    Toebbe, Jonathan; Gray, Fred; Grafil, Elliot; Greife, Uwe

    2010-11-01

    In the frame of a DoE Office of Nuclear Energy funded collaboration to design a next generation neutron elastic and inelastic scattering experiment, the Colorado School of Mines/Regis University group is responsible for developing and testing neutron detectors, pulse shape discrimination and read-out methods. This contribution will describe the test setup based on an n-ToF neutron selection using a ^244Cm-^13C source and the Regis Digitizer. Results on pulse shape discrimination from waveform digitization will be compared to other commercially available discrimination methods. We will also present our efforts to explore different types of algorithm for extraction of neutron assignment probabilities from the collected waveforms.

  12. Artifacts in digital images

    NASA Technical Reports Server (NTRS)

    Lorre, J. J.; Gillespie, A. R.

    1980-01-01

    Three kinds of artifacts unique to digital images are illustrated, namely aliasing caused by undersampling, interference phenomena caused by improper display of images, and harmonic overtones caused by quantization of amplitudes. Special attention is given to undersampling when the sample size and interval are the same. It is noted that this situation is important because it is typical of solid-state cameras. Quantization of image data of necessity introduces energy at harmonic overtones of the image spectrum. This energy is aliased if the frequency of the overtones is greater than 0.5 cycle/pixel. It cannot be selectively removed from the image through filtering, and the best way to suppress it is to maximize the amplification of the sensor before digital encoding.

  13. Digitally Enhanced Heterodyne Interferometry

    NASA Technical Reports Server (NTRS)

    Shaddock, Daniel; Ware, Brent; Lay, Oliver; Dubovitsky, Serge

    2010-01-01

    Spurious interference limits the performance of many interferometric measurements. Digitally enhanced interferometry (DEI) improves measurement sensitivity by augmenting conventional heterodyne interferometry with pseudo-random noise (PRN) code phase modulation. DEI effectively changes the measurement problem from one of hardware (optics, electronics), which may deteriorate over time, to one of software (modulation, digital signal processing), which does not. DEI isolates interferometric signals based on their delay. Interferometric signals are effectively time-tagged by phase-modulating the laser source with a PRN code. DEI improves measurement sensitivity by exploiting the autocorrelation properties of the PRN to isolate only the signal of interest and reject spurious interference. The properties of the PRN code determine the degree of isolation.

  14. Practical quantum digital signature

    NASA Astrophysics Data System (ADS)

    Yin, Hua-Lei; Fu, Yao; Chen, Zeng-Bing

    2016-03-01

    Guaranteeing nonrepudiation, unforgeability as well as transferability of a signature is one of the most vital safeguards in today's e-commerce era. Based on fundamental laws of quantum physics, quantum digital signature (QDS) aims to provide information-theoretic security for this cryptographic task. However, up to date, the previously proposed QDS protocols are impractical due to various challenging problems and most importantly, the requirement of authenticated (secure) quantum channels between participants. Here, we present the first quantum digital signature protocol that removes the assumption of authenticated quantum channels while remaining secure against the collective attacks. Besides, our QDS protocol can be practically implemented over more than 100 km under current mature technology as used in quantum key distribution.

  15. Digital numerically controlled oscillator

    NASA Technical Reports Server (NTRS)

    Cellier, A.; Huey, D. C.; Ma, L. N. (Inventor)

    1980-01-01

    The frequency and phase of an output signal from an oscillator circuit are controlled with accuracy by a digital input word. Positive and negative alterations in output frequency are both provided for by translating all values of input words so that they are positive. The oscillator reference frequency is corrected only in one direction, by adding phase to the output frequency of the oscillator. The input control word is translated to a single algebraic sign and the digital 1 is added thereto. The translated input control word is then accumulated. A reference clock signal having a frequency at an integer multiple of the desired frequency of the output signal is generated. The accumulated control word is then compared with a threshold level. The output signal is adjusted in a single direction by dividing the frequency of the reference clock signal by a first integer or by an integer different from the first integer.

  16. Digital Image Correlation Engine

    Energy Science and Technology Software Center (ESTSC)

    2015-10-06

    DICe is an open source digital image correlation (DIC) tool intended for use as a module in an external application or as a standalone analysis code. It's primary capability is computing full –field displacements and strains from sequences of digital These images are typically of a material sample undergoing a materials characterization experiment, but DICe is also useful for other applications (for example, trajectory tracking). DICe is machine portable (Windows, Linux and Mac) and canmore » be effectively deployed on a high performance computing platform. Capabilities from DICe can be invoked through a library interface, via source code integration of DICe classes or through a graphical user interface.« less

  17. Digital flight control systems

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Vanlandingham, H. F.

    1977-01-01

    The design of stable feedback control laws for sampled-data systems with variable rate sampling was investigated. These types of sampled-data systems arise naturally in digital flight control systems which use digital actuators where it is desirable to decrease the number of control computer output commands in order to save wear and tear of the associated equipment. The design of aircraft control systems which are optimally tolerant of sensor and actuator failures was also studied. Detection of the failed sensor or actuator must be resolved and if the estimate of the state is used in the control law, then it is also desirable to have an estimator which will give the optimal state estimate even under the failed conditions.

  18. Digital scale converter

    DOEpatents

    Upton, Richard G.

    1978-01-01

    A digital scale converter is provided for binary coded decimal (BCD) conversion. The converter may be programmed to convert a BCD value of a first scale to the equivalent value of a second scale according to a known ratio. The value to be converted is loaded into a first BCD counter and counted down to zero while a second BCD counter registers counts from zero or an offset value depending upon the conversion. Programmable rate multipliers are used to generate pulses at selected rates to the counters for the proper conversion ratio. The value present in the second counter at the time the first counter is counted to the zero count is the equivalent value of the second scale. This value may be read out and displayed on a conventional seven-segment digital display.

  19. A digital beacon receiver

    NASA Technical Reports Server (NTRS)

    Ransome, Peter D.

    1988-01-01

    A digital satellite beacon receiver is described which provides measurement information down to a carrier/noise density ratio approximately 15 dB below that required by a conventional (phase locked loop) design. When the beacon signal fades, accuracy degrades gracefully, and is restored immediately (without hysteresis) on signal recovery, even if the signal has faded into the noise. Benefits of the digital processing approach used include the minimization of operator adjustments, stability of the phase measuring circuits with time, repeatability between units, and compatibility with equipment not specifically designed for propagation measuring. The receiver has been developed for the European Olympus satellite which has continuous wave (CW) beacons at 12.5 and 29.7 GHz, and a switched polarization beacon at 19.8 GHz approximately, but the system can be reconfigured for CW and polarization-switched beacons at other frequencies.

  20. Metrological digital audio reconstruction

    DOEpatents

    Fadeyev; Vitaliy , Haber; Carl

    2004-02-19

    Audio information stored in the undulations of grooves in a medium such as a phonograph record may be reconstructed, with little or no contact, by measuring the groove shape using precision metrology methods coupled with digital image processing and numerical analysis. The effects of damage, wear, and contamination may be compensated, in many cases, through image processing and analysis methods. The speed and data handling capacity of available computing hardware make this approach practical. Two examples used a general purpose optical metrology system to study a 50 year old 78 r.p.m. phonograph record and a commercial confocal scanning probe to study a 1920's celluloid Edison cylinder. Comparisons are presented with stylus playback of the samples and with a digitally re-mastered version of an original magnetic recording. There is also a more extensive implementation of this approach, with dedicated hardware and software.

  1. Digital vibration control techniques

    NASA Technical Reports Server (NTRS)

    Chapman, P.; Kim, B. K.; Boctor, W.

    1974-01-01

    Analog vibration control techniques are reviewed and are compared with digital techniques. The advantages of the digital methods over the analog methods are demonstrated. The following topics are covered: (1) methods of computer-controlled random vibration and reverberation acoustic testing; (2) methods of computer-controlled sinewave vibration testing; and (3) methods of computer-controlled shock testing. Basic concepts are stressed rather than specific techniques or equipment. General algorithms are described in the form of block diagrams and flow diagrams. Specific problems and potential problems are discussed. The material is computer sciences oriented but is kept at a level that facilitates an understanding of the basic concepts of computer-controlled induced environmental test systems.

  2. Digital Image Velocimetry

    NASA Technical Reports Server (NTRS)

    Cho, Y.-C.

    1991-01-01

    Digital image velocimetry is technique for extracting two-dimensional (in image planes) velocities of objects from multiple photographs or video images of objects. Devised to overcome disadvantages of particle-image velocimetry and laser-speckle velocimetry, both of which involve use of illuminated seed particles to make flows visible. Directions of velocity vectors determined unambiguously, and dynamic range limited only by speed of camera or, equivalently, by speed of stroboscopic illumination.

  3. Digital optical spark chambers

    NASA Technical Reports Server (NTRS)

    Evenson, Paul; Tuska, Evelyn

    1989-01-01

    The authors constructed and tested a prototype digital readout system for optical spark chambers using a linear, solid-state charge-coupled-device detector array. Position resolution of 0.013 mm (sigma) over a 25-cm field of view has been demonstrated. It is concluded that this technique should permit the construction of economical, lightweight and low-power trajectory hodoscopes for use in cosmic-ray instrumentation on balloons and in spacecraft.

  4. Digital Holographic Logic

    NASA Technical Reports Server (NTRS)

    Preston, K., Jr.

    1972-01-01

    The characteristics of the holographic logic computer are discussed. The holographic operation is reviewed from the Fourier transform viewpoint, and the formation of holograms for use in performing digital logic are described. The operation of the computer with an experiment in which the binary identity function is calculated is discussed along with devices for achieving real-time performance. An application in pattern recognition using neighborhood logic is presented.

  5. DIGITAL Q METER

    DOEpatents

    Briscoe, W.L.

    1962-02-13

    A digital Q meter is described for measuring the Q of mechanical or electrical devices. The meter comprises in combination a transducer coupled to an input amplifier, and an upper and lower level discriminator coupled to the amplifier and having their outputs coupled to an anticoincidence gate. The output of the gate is connected to a scaler. The lower level discriminator is adjusted to a threshold level of 36.8 percent of the operating threshold level of the upper level discriminator. (AEC)

  6. Digital to synchro converter

    NASA Technical Reports Server (NTRS)

    Predina, Joseph P. (Inventor)

    1989-01-01

    A digital-to-synchro converter is provided where a binary input code specifies a desired shaft angle and where an resolver type position transducer is employed with additional circuitry to generate a shaft position error signal indicative of the angular difference between the desired shaft angle and the actual shaft angle. The additional circuitry corrects for known and calculated errors in the shaft position detection process and equipment.

  7. Digital Enhancement Of Pneumothoraces

    NASA Astrophysics Data System (ADS)

    Cocklin, M.; Kaye, G.; Kerr, I.; Lams, P.

    1982-11-01

    If a patient presents with symptoms indicative of a pneumothorax it is improbable that it would not be detected in a chest radiograph. However, detection on the radiograph can be difficult and a small pneumothorax may be missed when there is no clinical suspicion of its presence. This report presents some methods by which the characteristic pneumothorax edge may be enhanced by digital image processing. Various examples are given.

  8. Digital signal processing

    NASA Astrophysics Data System (ADS)

    Morgera, Salvatore D.; Krishna, Hari

    Computationally efficient digital signal-processing algorithms over finite fields are developed analytically, and the relationship of these algorithms to algebraic error-correcting codes is explored. A multidisciplinary approach is employed, in an effort to make the results accessible to engineers, mathematicians, and computer scientists. Chapters are devoted to systems of bilinear forms, efficient finite-field algorithms, multidimensional methods, a new class of linear codes, and a new error-control scheme.

  9. Digital Microfluidic Logic Gates

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Xu, Tao; Chakrabarty, Krishnendu

    Microfluidic computing is an emerging application for microfluidics technology. We propose microfluidic logic gates based on digital microfluidics. Using the principle of electrowetting-on-dielectric, AND, OR, NOT and XOR gates are implemented through basic droplet-handling operations such as transporting, merging and splitting. The same input-output interpretation enables the cascading of gates to create nontrivial computing systems. We present a potential application for microfluidic logic gates by implementing microfluidic logic operations for on-chip HIV test.

  10. Fingerprinting digital elevation maps

    NASA Astrophysics Data System (ADS)

    Gou, Hongmei; Wu, Min

    2006-02-01

    Digital elevation maps (DEMs) provide a digital representation of 3-D terrain information. In civilian applications, high-precision DEMs carry a high commercial value owing to the large amount of effort in acquiring them; and in military applications, DEMs are often used to represent critical geospatial information in sensitive operations. These call for new technologies to prevent unauthorized distribution and to trace traitors in the event of information leak related to DEMs. In this paper, we propose a new digital fingerprinting technique to protect DEM data from illegal re-distribution. The proposed method enables reliable detection of fingerprints from both 3-D DEM data set and its 2-D rendering, whichever format that is available to a detector. Our method starts with extracting from a DEM a set of critical contours either corresponding to important topographic features of the terrain or having application-dependent importance. Fingerprints are then embedded into these critical contours by employing parametric curve modeling and spread spectrum embedding. Finally, a fingerprinted DEM is constructed to incorporate the marked 2-D contours. Through experimental results, we demonstrate the robustness of the proposed method against a number of challenging attacks applied to either DEMs or their contour representations.

  11. All Spin Digital Circuits

    NASA Astrophysics Data System (ADS)

    Behin-Aein, Behtash; Datta, Deepanjan; Salahuddin, Sayeef; Datta, Supriyo

    2009-03-01

    Switching of a magnetic free layer using spin polarized current has been demonstrated in Magnetic Tunnel Junction (MTJ) devices. Currently MTJ's are being studied for memory and microwave oscillator applications. The purpose of this talk is to explore a modified MTJ where a clock pulse via the fixed layer facilities the switching of the free layer in accordance with a weak bias provided by an input magnet in the form of a spin current. Based on the Landau-Lifshitz-Gilbert equation (LLG) augmented with spin torque functions, we show the switching energy and the switching time of the free layer which indicates the possibility of very low power digital logic applications. Ordinary digital circuits store information in the form of capacitor charges that communicate through electrical interconnects. The purpose of this paper is to show that modified MTJ's can be the basis for all spin digital circuits. Our primary objective is to stimulate proof of concept experiments that could usher in a whole new set of devices suitable for spintronic circuits.

  12. Evolving Digital Ecological Networks

    PubMed Central

    Wagner, Aaron P.; Ofria, Charles

    2013-01-01

    “It is hard to realize that the living world as we know it is just one among many possibilities” [1]. Evolving digital ecological networks are webs of interacting, self-replicating, and evolving computer programs (i.e., digital organisms) that experience the same major ecological interactions as biological organisms (e.g., competition, predation, parasitism, and mutualism). Despite being computational, these programs evolve quickly in an open-ended way, and starting from only one or two ancestral organisms, the formation of ecological networks can be observed in real-time by tracking interactions between the constantly evolving organism phenotypes. These phenotypes may be defined by combinations of logical computations (hereafter tasks) that digital organisms perform and by expressed behaviors that have evolved. The types and outcomes of interactions between phenotypes are determined by task overlap for logic-defined phenotypes and by responses to encounters in the case of behavioral phenotypes. Biologists use these evolving networks to study active and fundamental topics within evolutionary ecology (e.g., the extent to which the architecture of multispecies networks shape coevolutionary outcomes, and the processes involved). PMID:23533370

  13. Digital Holography Display (2)

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Asundi, A.; Yu, Yang; Xiao, Zhen Zhong

    This paper describes the extension work from the last Digital Holography Projector System. From the developed works shows that, some unforeseen factors have created the difficulties for the system alignment. Such factors are the DMD frame rate, light source and diffractive zero order. It is really the challenging development works to achieve the virtual 3D model display on the high speed rotation screen. The three most key factors are emphasizing: 1) The display device's frame rate; 2) The light source orientation angle; and 3) The zero order filtering optic. 1) This device's is the digital micro mirror, in short is DMD. It is the high speed switching device has developed by the most recent technology. The switching frame rate can go up as high as 291fps. At first, the 8 bits depth file must be digitalized and stored for DMD onboard Ram. The digitalized data are transmitting from the PC USB to DMD onboard Ram. Instead of the data are downloading directly from the PC to DVI or VGA during display, this downloading method cause slower down the display speed, which is the common frame rate of 30 Hz. Next, the onboard Ram data then transfer to the DMD mirror's for display, at the 8 bits 291 fps speed. At this frame rate, the display 2D image can almost cover for 10 of out of the 360 0 in 1 revolution. 2) This laser light source must be installed such that free for orientated in any arbitrary angle from 220 to 450. Which is normalized to the DMD mirrors and the brief sketch show on figure (a). The purpose of orientated the light source is ensure that multi diffractive order would be reflected straight from the mirrors. (This multi diffractive order is the phenomenon of the digital micro mirror's characteristic). This mean, the reconstruct images would be followed the DMD normalized direction reflected up to fibre conduit. Moreover, this orientated method install of the laser light source is making space for other optical lenses or device driver/controller. Because, all

  14. Digital radiography in space.

    PubMed

    Hart, Rob; Campbell, Mark R

    2002-06-01

    With the permanent habitation of the International Space Station, the planning of longer duration exploration missions, and the possibility of space tourism, it is likely that digital radiography will be needed in the future to support medical care in space. Ultrasound is currently the medical imaging modality of choice for spaceflight. Digital radiography in space is limited because of prohibitive launch costs (in the region of $20,000/kg) that severely restrict the volume, weight, and power requirements of medical care hardware. Technological increases in radiography, a predicted ten-fold decrease in future launch costs, and an increasing clinical need for definitive medical care in space will drive efforts to expand the ability to provide medical care in space including diagnostic imaging. Normal physiological responses to microgravity, in conjunction with the high-risk environment of spaceflight, increase the risk of injury and could imply an extended recovery period for common injuries. The advantages of gravity on Earth, such as the stabilization of patients undergoing radiography and the drainage of fluids, which provide radiographic contrast, are unavailable in space. This creates significant difficulties in patient immobilization and radiographic positioning. Gravity-dependent radiological signs, such as lipohemarthrosis in knee and shoulder trauma, air or fluid levels in pneumoperitoneum, pleural effusion, or bowel obstruction, and the apical pleural edge in pneumothorax become unavailable. Impaired healing processes such as delayed callus formation following fracture will have implications on imaging, and recovery time lines are unknown. The confined nature of spacecraft and the economic impossibility of launching lead-based personal protective equipment present significant challenges to crew radiation safety. A modified, free-floating radiographic C-arm device equipped with a digital detector and utilizing teleradiology support is proposed as a

  15. DIGITAL ARCHITECTURE PROJECT PLAN

    SciTech Connect

    Thomas, Ken

    2014-09-01

    The objective of this project is to develop an industry consensus document on how to scope and implement the underlying information technology infrastructure that is needed to support a vast array of real-time digital technologies to improve NPP work efficiency, to reduce human error, to increase production reliability and to enhance nuclear safety. A consensus approach is needed because: • There is currently a wide disparity in nuclear utility perspectives and positions on what is prudent and regulatory-compliant for introducing certain digital technologies into the plant environment. For example, there is a variety of implementation policies throughout the industry concerning electromagnetic compatibility (EMC), cyber security, wireless communication coverage, mobile devices for workers, mobile technology in the control room, and so forth. • There is a need to effectively share among the nuclear operating companies the early experience with these technologies and other forms of lessons-learned. There is also the opportunity to take advantage of international experience with these technologies. • There is a need to provide the industry with a sense of what other companies are implementing, so that each respective company can factor this into their own development plans and position themselves to take advantage of new work methods as they are validated by the initial implementing companies. In the nuclear power industry, once a better work practice has been proven, there is a general expectation that the rest of the industry will adopt it. However, the long-lead time of information technology infrastructure could prove to be a delaying factor. A secondary objective of this effort is to provide a general understanding of the incremental investment that would be required to support the targeted digital technologies, in terms of an incremental investment over current infrastructure. This will be required for business cases to support the adoption of these new

  16. Land Treatment Digital Library

    USGS Publications Warehouse

    Pilliod, David S.

    2009-01-01

    Across the country, public land managers make hundreds of decisions each year that influence landscapes and ecosystems within the lands they manage. Many of these decisions involve vegetation manipulations known as land treatments. Land treatments include activities such as removal or alteration of plant biomass, seeding burned areas, and herbicide applications. Data on these land treatments are usually stored at local offices, and gathering information across large spatial areas can be difficult. There is a need to centralize and store treatment data for Federal agencies involved in land treatments because these data are useful to land managers for policy and management and to scientists for developing sampling designs and studies. The Land Treatment Digital Library (LTDL) was created by the U.S. Geological Survey (USGS) to catalog information about land treatments on Federal lands in the western United States for all interested parties. The flexible framework of the library allows for the storage of a wide variety of data in different formats. The LTDL currently stores previously established land treatments or what often are called legacy data. The project was developed and has been refined based on feedback from partner agencies and stakeholders, with opportunity for the library holdings to expand as new information becomes available. The library contains data in text, tabular, spatial, and image formats. Specific examples include project plans and implementation reports, monitoring data, spatial data files from geographic information systems, digitized paper maps, and digital images of land treatments. The data are entered by USGS employees and are accessible through a searchable web site. The LTDL can be used to respond to information requests, conduct analyses and other forms of information syntheses, produce maps, and generate reports for DOI managers and scientists and other authorized users.

  17. Digital image velocimetry

    NASA Technical Reports Server (NTRS)

    Cho, Y.-C.

    1989-01-01

    Digital image velocimetry is proposed for the measurement of the instantaneous velocity fields of time dependent flows. This technique improves the flow measurement by eliminating some of the restrictions on existing optical methods (i.e., laser speckle velocimetry and particle image velocimetry). Among these restrictions are the limited dynamic range of the velocity measurement, directional ambiguity of the velocity vector, and the difficulty of a real-time capability. The present technique greatly enhances the dynamic range of the velocity measurement and unequivocally determines the direction of the velocity vector.

  18. Direct to Digital Holography

    SciTech Connect

    Bingham, P.R.; Tobin, K.W.

    2007-09-30

    In this Cooperative Research and Development Agreement (CRADA), Oak Ridge National Laboratory (ORNL) assisted nLine Corporation of Austin, TX in the development of prototype semiconductor wafer inspection tools based on the direct-to-digital holographic (DDH) techniques invented at ORNL. Key components of this work included, testing of DDH for detection of defects in High Aspect Ratio (HAR) structures, development of image processing techniques to enhance detection capabilities through the use of both phase and intensity, and development of methods for autofocus on the DDH tools.

  19. Digital processing clock

    NASA Technical Reports Server (NTRS)

    Phillips, D. H.

    1982-01-01

    Tthe digital processing clock SG 1157/U is described. It is compatible with the PTTI world where it can be driven by an external cesium source. Built-in test equipment shows synchronization with cesium through 1 pulse per second. It is built to be expandable to accommodate future time-keeping needs of the Navy as well as any other time ordered functions. Examples of this expandibility are the inclusion of an unmodulated XR3 time code and the 2137 modulate time code (XR3 with 1 kHz carrier).

  20. Land Treatment Digital Library

    USGS Publications Warehouse

    Pilliod, David S.; Welty, Justin L.

    2013-01-01

    The Land Treatment Digital Library (LTDL) was created by the U.S. Geological Survey to catalog legacy land treatment information on Bureau of Land Management lands in the western United States. The LTDL can be used by federal managers and scientists for compiling information for data-calls, producing maps, generating reports, and conducting analyses at varying spatial and temporal scales. The LTDL currently houses thousands of treatments from BLM lands across 10 states. Users can browse a map to find information on individual treatments, perform more complex queries to identify a set of treatments, and view graphs of treatment summary statistics.

  1. Programmable Digital Controller

    NASA Technical Reports Server (NTRS)

    Wassick, Gregory J.

    2012-01-01

    An existing three-channel analog servo loop controller has been redesigned for piezoelectric-transducer-based (PZT-based) etalon control applications to a digital servo loop controller. This change offers several improvements over the previous analog controller, including software control over proportional-integral-derivative (PID) parameters, inclusion of other data of interest such as temperature and pressure in the control laws, improved ability to compensate for PZT hysteresis and mechanical mount fluctuations, ability to provide pre-programmed scanning and stepping routines, improved user interface, expanded data acquisition, and reduced size, weight, and power.

  2. Digital system bus integrity

    NASA Technical Reports Server (NTRS)

    Eldredge, Donald; Hitt, Ellis F.

    1987-01-01

    This report summarizes and describes the results of a study of current or emerging multiplex data buses as applicable to digital flight systems, particularly with regard to civil aircraft. Technology for pre-1995 and post-1995 timeframes has been delineated and critiqued relative to the requirements envisioned for those periods. The primary emphasis has been an assured airworthiness of the more prevalent type buses, with attention to attributes such as fault tolerance, environmental susceptibility, and problems under continuing investigation. Additionally, the capacity to certify systems relying on such buses has been addressed.

  3. Pediatric digital subtraction angiography

    SciTech Connect

    Amundson, G.M.; Wesenberg, R.L.; Mueller, D.L.; Reid, R.H.

    1984-12-01

    Experience with intravenous digital subtraction angiography (DSA) in infants and children is limited, although its relative rate of performance, low complication rate, and diagnostic accuracy indicate great potential. The authors performed 87 DSA examinations (74 patients) and obtained sufficient detail to facilitate diagnosis in most cases. The major problems of patient movement and overlapping vessels can be minimized by judicious use of sedation and strict attention to technique. Exposure of patients to radiation has not been a limiting factor since our system uses low exposure factors. Our results demonstrate that DSA has wide applicability to many organ systems and is especially useful in intracranial disease and for preoperative evaluation of neoplasms.

  4. Digitized sunshine aids architects

    SciTech Connect

    Stix, G.

    1988-03-01

    The author explains how computers are being used to help architects design buildings to apply natural lighting. This is called daylighting. The aim is to reduce energy usage and to cut down on the need for harsh, expensive electric lighting. To help analyze distribution of natural light in a scale model architects employ innovative sky simulators, as well as digitized images and computer models that determine surface brightness. Mainframe computer programs calculate light distribution and model how daylight interacts with electric lighting systems. This article explains how daylighting is used at the Olympic Oval built for the Winter Games in Calgary, Alta., Canada and at Seattle's Pacific Museum of Flight.

  5. Digital focusing schlieren imaging

    NASA Astrophysics Data System (ADS)

    Buckner, Benjamin D.; Trolinger, James D.; L'Esperance, Drew

    2015-09-01

    Since its invention in the 19th century, schlieren imaging has been an essential method for studying many aerodynamic effects, particularly convection and shock waves, but the classical method using parabolic mirrors is extremely difficult to set up and very expensive for large fields of view. Focusing schlieren methods have made large- area schlieren more feasible but have tended to be difficult to align and set up, limiting their utility in many applications We recently developed an alternative approach which utilizes recent advances in digital display technology to produce simpler schlieren system that yields similar sensitivity with greater flexibility.

  6. Digital communication system

    NASA Technical Reports Server (NTRS)

    Monford, L. G., Jr. (Inventor)

    1974-01-01

    A digital communication system is reported for parallel operation of 16 or more transceiver units with the use of only four interconnecting wires. A remote synchronization circuit produces unit address control words sequentially in data frames of 16 words. Means are provided in each transceiver unit to decode calling signals and to transmit calling and data signals. The transceivers communicate with each other over one data line. The synchronization unit communicates the address control information to the transceiver units over an address line and further provides the timing information over a clock line. A reference voltage level or ground line completes the interconnecting four wire hookup.

  7. National Digital Orthophoto Program

    USGS Publications Warehouse

    USDA Natural Resources Conservation Service; Farm Service Agency; National States Geographic Information Council; U.S. Forest Service; U.S. Geological Survey

    1996-01-01

    A critical component of the National Spatial Data Infrastructure (NSDI) is Framework. Framework provides a base on which to collect, register, and integrate geospatial information accurately and consistently. The Federal Geographic Data Committee (FGDC) proposed that Framework include geodetic control, orthoimagery, elevation, transportation, hydrography, governmental units, and cadastral data. The Mapping Science Committee of the National Research Council recommends that geodetic control, orthoimagery, and elevation data become the critical foundation of the NSDI. The National Digital Orthophoto Program (NDOP) is a working model on how Federal, State, and local government, as well as private industry, can participate to develop the orthoimagery Framework for the Nation.

  8. Personal digital assistants.

    PubMed

    Wiggins, Richard H

    2004-03-01

    Personal digital assistant sales are growing exponentially, and as medical technology advances the amount of information available becomes staggering, making a handheld device, with the ability to store a great amount of information, progressively more valuable to health care providers. Mobile computing allows for a great deal of knowledge in a small package, creating a "walking library" with a mobile collection of data always accessible. There are many diverse types of PDAs, and this article discusses the history of PDAs, general purchasing issues, general PDA features, and the most significant differences between the Palm and the Windows CE operating systems. PMID:15255514

  9. Guide to Digital Radiographic Imaging.

    PubMed

    Mol, André; Yoon, Douglas C

    2015-09-01

    This is a resource for clinicians who are considering purchasing a digital imaging system or those already using one who want to optimize its use. It covers selected topics in digital imaging fundamentals, detector technology, image processing and quality assurance. Through a critical appraisal of the strengths and limitations of digital imaging components, the goal of this guide is to contribute to the appropriate use of these systems to maximize the health benefit for patients. PMID:26820007

  10. Basic digital photography in dermatology.

    PubMed

    Kaliyadan, Feroze; Manoj, Jayasree; Venkitakrishnan, S; Dharmaratnam, A D

    2008-01-01

    Digital photography has virtually replaced conventional film photography as far as clinical imaging is concerned. Though most dermatologists are familiar with digital cameras, there is room for improvement in the quality of clinical images. We aim to give an overview of the basics of digital photography in relation to dermatology, which would be useful to a dermatologist in his or her future clinical practice. PMID:19052435

  11. A Digital Solar Aspect Sensor

    NASA Technical Reports Server (NTRS)

    Albus, James S.

    1961-01-01

    The solar aspect sensor described herein performs the analog-to-digital conversion of data optically. To accomplish this, it uses a binary "Gray code" light mask to produce a digital indication, in vehicle-fixed coordinates, of the elevation and azimuth angles of incident light from the sun. This digital solar aspect sensor system, in Explorer X, provided measurements of both elevation and azimuth angles to +/- 2 degrees at a distance of over 140,000 statute miles.

  12. Angle-indicating digital servo

    NASA Technical Reports Server (NTRS)

    Parra, G. T.

    1977-01-01

    Device determines position of capacitive pickup relative to gravity-stabilized inductive element. Self nulling bridge with digital readout is faster and more accurate than electromechanical equivalent.

  13. Architectural Optimization of Digital Libraries

    NASA Technical Reports Server (NTRS)

    Biser, Aileen O.

    1998-01-01

    This work investigates performance and scaling issues relevant to large scale distributed digital libraries. Presently, performance and scaling studies focus on specific implementations of production or prototype digital libraries. Although useful information is gained to aid these designers and other researchers with insights to performance and scaling issues, the broader issues relevant to very large scale distributed libraries are not addressed. Specifically, no current studies look at the extreme or worst case possibilities in digital library implementations. A survey of digital library research issues is presented. Scaling and performance issues are mentioned frequently in the digital library literature but are generally not the focus of much of the current research. In this thesis a model for a Generic Distributed Digital Library (GDDL) and nine cases of typical user activities are defined. This model is used to facilitate some basic analysis of scaling issues. Specifically, the calculation of Internet traffic generated for different configurations of the study parameters and an estimate of the future bandwidth needed for a large scale distributed digital library implementation. This analysis demonstrates the potential impact a future distributed digital library implementation would have on the Internet traffic load and raises questions concerning the architecture decisions being made for future distributed digital library designs.

  14. Programmable digital modem

    NASA Technical Reports Server (NTRS)

    Poklemba, John J.

    1991-01-01

    The design of the Programmable Digital Modem (PDM) is outlined. The PDM will be capable of operating with numerous modulation techniques including: 2-, 4-, 8- and 16-ary phase shift keying (PSK), minimum shift keying (MSK), and 16-ary quadrature amplitude modulation (QAM), with spectral occupancy from 1.2x to 2x the data symbol rate. It will also be programmable for transmission rates ranging from 2.34 to 300 Mbit/s, where the maximum symbol rate is 75 Msymbol/s. Furthermore, these parameters will be executable in independent burst, dependent burst, or continuous mode. In dependent burst mode the carrier and clock oscillator sources are common from burst to burst. To achieve as broad a set of requirements as these, it is clear that the essential signal processing must be digital. In addition, to avoid hardware changes when the operational parameters are changed, a fixed interface to an analog intermediate frequency (IF) is necessary for transmission; and, common system level architectures are necessary for the modulator and demodulator. Lastly, to minimize size and power, as much of the design as possible will be implemented with application specific integrated circuit (ASIC) chips.

  15. Aquarius Digital Processing Unit

    NASA Technical Reports Server (NTRS)

    Forgione, Joshua; Winkert, George; Dobson, Norman

    2009-01-01

    Three documents provide information on a digital processing unit (DPU) for the planned Aquarius mission, in which a radiometer aboard a spacecraft orbiting Earth is to measure radiometric temperatures from which data on sea-surface salinity are to be deduced. The DPU is the interface between the radiometer and an instrument-command-and-data system aboard the spacecraft. The DPU cycles the radiometer through a programmable sequence of states, collects and processes all radiometric data, and collects all housekeeping data pertaining to operation of the radiometer. The documents summarize the DPU design, with emphasis on innovative aspects that include mainly the following: a) In the radiometer and the DPU, conversion from analog voltages to digital data is effected by means of asynchronous voltage-to-frequency converters in combination with a frequency-measurement scheme implemented in field-programmable gate arrays (FPGAs). b) A scheme to compensate for aging and changes in the temperature of the DPU in order to provide an overall temperature-measurement accuracy within 0.01 K includes a high-precision, inexpensive DC temperature measurement scheme and a drift-compensation scheme that was used on the Cassini radar system. c) An interface among multiple FPGAs in the DPU guarantees setup and hold times.

  16. Digital Synchronizer without Metastability

    NASA Technical Reports Server (NTRS)

    Simle, Robert M.; Cavazos, Jose A.

    2009-01-01

    A proposed design for a digital synchronizing circuit would eliminate metastability that plagues flip-flop circuits in digital input/output interfaces. This metastability is associated with sampling, by use of flip-flops, of an external signal that is asynchronous with a clock signal that drives the flip-flops: it is a temporary flip-flop failure that can occur when a rising or falling edge of an asynchronous signal occurs during the setup and/or hold time of a flip-flop. The proposed design calls for (1) use of a clock frequency greater than the frequency of the asynchronous signal, (2) use of flip-flop asynchronous preset or clear signals for the asynchronous input, (3) use of a clock asynchronous recovery delay with pulse width discriminator, and (4) tying the data inputs to constant logic levels to obtain (5) two half-rate synchronous partial signals - one for the falling and one for the rising edge. Inasmuch as the flip-flop data inputs would be permanently tied to constant logic levels, setup and hold times would not be violated. The half-rate partial signals would be recombined to construct a signal that would replicate the original asynchronous signal at its original rate but would be synchronous with the clock signal.

  17. Computer enhanced digital angiography.

    PubMed

    Vas, R; Diamond, G A; Levisman, J A; Nakano, F H; Neidorf, B S; Rose, R M; Whiting, J S; Forrester, J S

    1982-05-01

    A new computer image enhancement technique was employed on cardiac images of 10 dogs and 7 patients to demonstrate the feasibility of an on-line automatic delineation of the left ventricular endocardial silhouette with a peripheral venous injection of contrast material while simultaneously reducing the x-ray dosage. This technique employs a very fast analog-to-digital conversion system capable of digitizing on-line video frames. By storing and continuously updating the first 30 video frames and then subtracting each incoming frame from this memory, most of the background is eliminated leaving only the contrast filled ventricle. Using calibrated densitometric measurements, we found that iodine concentrations in the human left ventricle following venous injection of 40 ml Renografin-76 (25 ml/s), peaked at 4.3 +/- 0.3 mg/ml (mean +/- SD) compared to 14.8 +/- 0.8 mg/ml following direct injection of 40 ml at 13 ml/s (p less than 0.001). The computer enhanced venous-injected images had an optical contrast 14 times greater than that of the unenhanced direct left ventriculogram. This increase in optical contrast provided unambiguous subjective definition of the endocardial borders. This technique is applicable to both central and peripheral contrast injection whereby high quality images can be obtained at approximately 98% reduction in radiation (5 mA, 65-85 kV), allowing performance of serial studies. PMID:7094444

  18. Monitoring the Digital Divide

    SciTech Connect

    Cottrell, Les

    2003-05-28

    It is increasingly important to support the large numbers of scientists working in remote areas and having low bandwidth access to the Internet. This will continue to be the case for years to come since there is evidence from PingER performance measurements that the, so-called, digital divide is not decreasing. In this work, we review the collaborative work of The Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste, a leading organization promoting science dissemination in the developing world- and SLAC in Stanford, to monitor by PingER, Universities and Research Institutions all over the developing world following the recent ''Recommendations of Trieste'' to help bridge the digital divide. As a result, PingER's deployment now covers the real-time monitoring of worldwide Internet performance and, in particular, West and Central Africa for the first time. We report on the results from the ICTP sites and quantitatively identify regions with poor performance, identify trends, discuss experiences and future work.

  19. Digital Imaging Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bamberger, Casimir; Renz, Uwe; Bamberger, Andreas

    2011-06-01

    Methods to visualize the two-dimensional (2D) distribution of molecules by mass spectrometric imaging evolve rapidly and yield novel applications in biology, medicine, and material surface sciences. Most mass spectrometric imagers acquire high mass resolution spectra spot-by-spot and thereby scan the object's surface. Thus, imaging is slow and image reconstruction remains cumbersome. Here we describe an imaging mass spectrometer that exploits the true imaging capabilities by ion optical means for the time of flight mass separation. The mass spectrometer is equipped with the ASIC Timepix chip as an array detector to acquire the position, mass, and intensity of ions that are imaged by matrix-assisted laser desorption/ionization (MALDI) directly from the target sample onto the detector. This imaging mass spectrometer has a spatial resolving power at the specimen of (84 ± 35) μm with a mass resolution of 45 and locates atoms or organic compounds on a surface area up to ~2 cm2. Extended laser spots of ~5 mm2 on structured specimens allows parallel imaging of selected masses. The digital imaging mass spectrometer proves high hit-multiplicity, straightforward image reconstruction, and potential for high-speed readout at 4 kHz or more. This device demonstrates a simple way of true image acquisition like a digital photographic camera. The technology may enable a fast analysis of biomolecular samples in near future.

  20. Digital holographic display

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Chia, Yong Poo; Singh, Vijay Raj; Asundi, A.; Khoo, Xuan Jie; Tay, Kiat Long; Zhou, Junxiang

    2009-12-01

    This paper describes how a Digital Holographic Projector is designed and implemented to project two-dimension virtual images onto the volumetric display media. In this research, we focus on the method to create 3D models, diffractive algorithm and the display media. A 3D model is generated based on the 360° view with views at every 10° interval from a 3D perspective view software. The hologram interference fringes are re-producing from the Fraunhofer algorithm. In order to make more flexible and portable, a Compact Vision System is introduced to storage multiply interference fringes. At the same time, the fringes are sent out at 30 Hz frame by frame continually to the digital micro-mirror1. With the presence of Nd: YVO4 green laser and various optical components, the 3D 360° hologram images are dynamically reconstructed and projected onto the high speed rotating diffuser forming a 3D model at any viewing angle on the volumetric display media. Both volumetric display media, wet and dry methods are demonstrated to show their feasibility and convenience. Finally, the dry volumetric technique with vertical projection mounting is adopted and as the result shown that the speckle noise is significance reduced.

  1. Digital holographic display

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Chia, Yong Poo; Singh, Vijay Raj; Asundi, A.; Khoo, Xuan Jie; Tay, Kiat Long; Zhou, Junxiang

    2010-03-01

    This paper describes how a Digital Holographic Projector is designed and implemented to project two-dimension virtual images onto the volumetric display media. In this research, we focus on the method to create 3D models, diffractive algorithm and the display media. A 3D model is generated based on the 360° view with views at every 10° interval from a 3D perspective view software. The hologram interference fringes are re-producing from the Fraunhofer algorithm. In order to make more flexible and portable, a Compact Vision System is introduced to storage multiply interference fringes. At the same time, the fringes are sent out at 30 Hz frame by frame continually to the digital micro-mirror1. With the presence of Nd: YVO4 green laser and various optical components, the 3D 360° hologram images are dynamically reconstructed and projected onto the high speed rotating diffuser forming a 3D model at any viewing angle on the volumetric display media. Both volumetric display media, wet and dry methods are demonstrated to show their feasibility and convenience. Finally, the dry volumetric technique with vertical projection mounting is adopted and as the result shown that the speckle noise is significance reduced.

  2. KEK digital accelerator

    NASA Astrophysics Data System (ADS)

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  3. My Three Wishes for Digital Repositories. Building Digital Libraries

    ERIC Educational Resources Information Center

    Huwe, Terence K.

    2005-01-01

    In this column on digital repository management, the author defines three areas within the sphere of digital repositories that need work. The first two pertain to information architecture, while the last one pertains to taking action. The author's first "wish" is for top-notch library Web sites that act as a gateway to any sphere of knowledge. He…

  4. Conceptualizing Digital Literacies and Digital Ethics for Sustainability Education

    ERIC Educational Resources Information Center

    Brown, Susan A.

    2014-01-01

    Purpose: The purpose of this paper is to discuss the need for integrating a focus on digital literacies and digital ethics into sustainability education, proposing a conceptualization of these for sustainability education. Design/methodology/approach: The paper draws on relevant literature in the field of sustainability education and in the field…

  5. Analogue-to-Digital and Digital-to-Analogue Conversion.

    ERIC Educational Resources Information Center

    Gregory, Martin

    1997-01-01

    Discusses circuits for three-bit and four-bit analogue digital converters and digital analogue converters. These circuits feature slow operating speeds that enable the circuitry to be used to demonstrate the mode of operation using oscilloscopes and signal generators. (DDR)

  6. Digital Natives Revisited: Developing Digital Wisdom in the Modern University

    ERIC Educational Resources Information Center

    Harris, David

    2012-01-01

    The seminal work of Prensky on "digital natives" and "digital wisdom" is used to launch a broader discussion on the relations between electronic communication, higher education, and popular and elite culture. Prensky's critics commonly contrast his polarisations and generational divisions with a more complex picture of types of engagement with…

  7. Let's Talk about Digital Learners in the Digital Era

    ERIC Educational Resources Information Center

    Gallardo-Echenique, Eliana Esther; Marqués-Molías, Luis; Bullen, Mark; Strijbos, Jan-Willem

    2015-01-01

    This paper reports on a literature review of the concept of "Digital Natives" and related terms. More specifically, it reports on the idea of a homogeneous generation of prolific and skilled users of digital technology born between 1980 and 1994. In all, 127 articles published between 1991 and 2014 were reviewed. On the basis of the…

  8. Accessing Digital Libraries: A Study of ARL Members' Digital Projects

    ERIC Educational Resources Information Center

    Kahl, Chad M.; Williams, Sarah C.

    2006-01-01

    To ensure efficient access to and integrated searching capabilities for their institution's new digital library projects, the authors studied Web sites of the Association of Research Libraries' (ARL) 111 academic, English-language libraries. Data were gathered on 1117 digital projects, noting library Web site and project access, metadata, and…

  9. Teaching and Learning in the Digital Age

    ERIC Educational Resources Information Center

    Starkey, Louise

    2012-01-01

    "Teaching and Learning in the Digital Age" is for all those interested in considering the impact of emerging digital technologies on teaching and learning. It explores the concept of a digital age and perspectives of knowledge, pedagogy and practice within a digital context. By examining teaching with digital technologies through new learning…

  10. Older people and digital disengagement: a fourth digital divide?

    PubMed

    Olphert, Wendy; Damodaran, Leela

    2013-01-01

    Digital technologies are becoming more pervasive in all areas of society. Enabling everyone to have access and capability to use the Internet and associated digital technologies, summed up in the term 'digital inclusion', is seen to have wide-ranging benefits to the individual, to the economy and to society. For older people, being digitally included can help them to maintain their independence, social connectedness and sense of worth in the face of declining health or limited capabilities, as well as also offering new opportunities to improve their quality of life. At present however, access to the technology and to the benefits is not equally distributed either between or within nations, and older people tend to be on the 'wrong' side of what is termed the 'digital divide'. Governments globally are developing strategies to promote digital inclusion and indeed Internet uptake is increasing steadily, including amongst older people. However, such strategies have focussed on getting people online, and there appears to be an assumption that once someone is online they will remain 'digitally engaged'. In fact statistics show that some users give up using the Internet, and there is emerging evidence that older people are more vulnerable to the factors which can lead to this outcome. The authors see this phenomenon as a potential but largely unrecognised 'fourth digital divide' which has serious implications for social inclusion. The objectives of this article are (a) to raise awareness of the phenomenon of digital disengagement by considering some of the emerging evidence, (b) to explore some of the potential implications of not recognising and therefore not addressing the needs of the digitally disengaged older population, and (c) to reveal the prevailing gap in knowledge which future research should address. PMID:23969758